In a segmented bar having a longitudinal axis, a first bar section slidably interengageable with a second bar section under longitudinal axially displacement to move into and out of end to end abutting interlocking mating relation, each of said bar sections presenting corresponding longitudinally extending mating surface formations on opposite sides and corresponding longitudinally extending mating edge formations along opposite edges, each bar section terminating in an abutting end edge formation to be presented to the abutting end edge formation of the other of said bar sections when disposed in interlocking mating relation, the opposed surface formations of one of said sections each including a locating recess therein and offset in relation to each other and each bounded by a portion of the extent of its adjacent abutting end edge formation, the opposed surface formations of the other of said sections each including a mating projection for each of said locating recesses and likewise offset in relation to each other and each bounded by a portion of the extent of its adjacent abutting end edge formation, said opposed locating recesses and projections being slidably interengageably in at least one longitudinal axially orientation thereof for longitudinal displacement of said bar sections into and out of end to end abutting interlocking mating relation. Said bar section when disposed in end to end abutting interlocking mating relation presents peripheral abutting end edge formations being offset longitudinally to one another.

Jointed or segmented bars can be utilized in a variety of circumstances in industry. It is desirable where jointing is undertaken to provide an arrangement which ensures full mating interengagement and is self-sustaining in interlocked relation, with registration, attachability and detachability of the respective sections readily accomplished and with the strength of the joint so established fully dependable within assigned limits of loading.
More particularly, the chain saw industry has adopted a jointed or segmented saw bar structure for a certain range of professional sizes and for certain range of domestic user sizes which segmented bar includes a main saw bar section and a replaceable rounded tip or nose section the nose section the nose section carrying a sprocket rotatably mounted therewithin on suitable bearings and being adapted to support and guide an endless saw chain as it is driven around the outermost curvate saw bar tip.
The adoption of the segmented saw bar has materially extended the useful life of the overall saw bar structure, in preserving the main saw bar section by allowing for repair or replacement of the rounded nose section which is normally subjected to greater loading abrasion and abuse.
Moreover, with the segmented saw bar the operator of the chain saw can readily detach and replace a damaged nose section in the field without any sophisticated tool or equipment.
A number of segmented or composite saw bar structures have been disclosed in prior published patents. As well several such structures have been manufactured and sold, some of which are reflected by those patents.
The following United States and Canadian patents illustrate a number of alternative proposals which will serve as background to those structures embodying the invention to be described and illustrated herein namely: U.S. Pat. Nos. 2,838,833, 2,888,964, 2,962,061, 3,124,177, 3,762,047 and 3,949,475. Canadian Pat. Nos. 506,987, 607,857, 696,847, 737,679 and 1,026,651.
The segmented saw or guide bar of the type under consideration can be derived from an elongated relatively heavy suitable steel bar or plate which is provided with a peripheral groove formation by a milling operation and subsequent heat treatment to provide a useable hardness.
It is common practice in the case of heavier saw bars which do not employ any sprocket or nose wheel to increase wear resistant of certain edges, particularly the edges of the rounded tip or nose section by applying a substance identified by the trade mark "Stellite" which increases resistance to wear and fatigue and consequent failure inflicted by frictional forces applied to such region particularly when the nose section is used for boring or plunge cutting.
The typical groove formation of a saw bar includes uniformly spaced apart rail formations arranged peripherally and outermost of the longitudinal and curvate edges of the tip or nose section, the dimensions of such groove formation being selected such that the bottom of the groove lies below the feet or tangs of centrally located drive links of the saw chain loop to be mounted upon the saw bar and so that the flanking rail formations support the tie straps or side links of such saw chain as it is driven in its endless path around the saw bar periphery.
Saw bars can also be fabricated from two-ply or three-ply laminates. The more common three-ply laminate is derived from three suitable steel bars or plates, the outer flanking plates typically having like dimensions and configuration and with the centrally located or sandwiched plate having a configuration corresponding to the flanking plates but of reduced dimensions so that when assembled and laminated the composite bar presents the aforementioned peripherally extending pair of rail formations outermost.
The rail formations of laminated bars particularly those portions bounding the tip or nose section being subjected to the same excessive wear and abuse likewise were usually protected by applying "Stellite" or other suitable material.
The introduction of direct drive chain saws lead to greatly increased wear and deterioration of saw bars. Solutions proposed included the adoption of the roller nose and the sprocket nose.
By modifying saw bars whether solid or laminated to provide a rotatable nose wheel or sprocket mounted upon bearings adjacent the nose end of such saw bar the saw chain could be carried around the nose out of close contact with the rail formation surfaces and so decrease frictional contact and wear.
An early example of a nose section carrying a sprocket is illustrated and described in U.S. Pat. No. 2,316,997.
Saw bar structures have been reduced in size, and the operating charcteristics of roller nose and sprocket nose bar have improved. However, the introduction of smaller chain did not lead to the adoption of smaller saw bar structures; rather it was the advent of smaller and lighter power heads that dictated the bar size and consequential chain pitch reduction. Yet the size reductions did not improve the operating characteristics of the roller and sprocket nose. These improvements were made by adjustments in design and processes brought about by failure analyses.
Notwithstanding such improved performance and increased life expectancy it was still desirable if not necessary to provide a segmented saw bar structure wherein the nose sections or assemblies could be readily replaced if damaged leading to the development of better jointing structures, for example, that revealed by U.S. Pat. No. 3,762,047 originating with the inventor named herein.
The segmented saw bar disclosed and claimed in U.S. Pat. No. 3,762,047 utilizes a main saw bar section presenting a bifurcated abutting end edge formation to the nose section and is adapted to receive mating spaced projections carried by the nose section the latter being provided with suitable reinforcing spacers therebetween to achieve a precise interfitting relationship when fully registered.
The bifurcations of the main saw bar section of U.S. Pat. No. 3,762,047 when subjected to requisite heat treatment or flame hardening tend to undergo dimensional changes in that region which afterwards must be corrected by grinding.
Moreover, with such arrangement it has been observed when the nose section is used for prying or is twisted the forces in shear applied to the bifurcations tended to cause early fatigue and failure.
Further, as will be observed the segmented saw bar of U.S. Pat. No. 3,762,047 includes abutting end edge formations which extend transversely of the longitudinal axis thereof and particularly in the region of abutment of the composite rail formations end edges lie in a common transverse plane.
An endless loop of saw chains on being driven against such rail discontinuity tends to have a standing wave imparted to it generating reactive forces which give rise to severe wear patterns in the bar periphery thereby shortening the useful life of such bar structure.


The invention provides a process for paper-making comprising adding to pulp slurry at least a first aqueous liquid and a second aqueous liquid so as to obtain a paper stock; forming the paper stock so as to obtain a wet paper web; pressing and draining the wet paper web so as to obtain a wet paper sheet; and drying the wet paper sheet so as to obtain a paper sheet. Correspondingly, the invention provides an aid composition for paper-making.

Chemical aids for paper play an important role in the sustainable development of the paper-making industry, and therefore attract extensive attention. Chemical aids in paper-making can be classified into processing aids and functional aids. One of the functional aids is the strength aids, including dry strength aids, wet strength aids and temporary wet strength aids, etc.
A polymer of glyoxylated polyacrylamides, GPAMs, is one of frequently used temporary wet strength aids, as well as one of frequently used dry strength aids (see, e.g., U.S. Pat. No. 3,556,932A, U.S. Pat. No. 4,605,702A, U.S. Pat. No. 5,674,362A, U.S. Pat. No. 6,245,874B1, WO0011046A1, U.S. Pat. No. 7,641,766B2 and U.S. Pat. No. 7,901,543B2).
GPAMs are provided mainly in the form of a polymer solution. Generally speaking, if having the same solid content in the polymer solution, GPAMs with a higher molecular weight can provide a better temporary wet strengthening effect. However, the higher the molecular weight, the easier the GPAMs become gelled, so that the shelf life of the polymer solution is shortened, limiting the practical application of the polymer solution in the paper-making process. In order to secure that the polymer solution has a suitable shelf-life, usually it is necessary to (1) reduce the solid content of GPAMs in the polymer solution, or (2) reduce the molecular weight of GPAMs. As for (1), it requires that the solid content of the GPAMs in the polymer solution remains constant, normally between 8 and 20 wt %, for the sake of production and transportation. As for (2), more GPAMs with a lower molecular weight are required to be added into the pulp, compared to the GPAM with the higher molecular weight, in order to realize a comparable temporary wet strengthening effect, which is obviously not economical. In particular, the GPAMs with a weight average molecular weight of from 100,000 to 300,000 Dalton, despite its longer shelf life, has no practical application in the industry due to its unsatisfactory strengthening effect.
Therefore, how to endow the GPAMs with a better temporary wet strengthening effect without increasing the dosage of the GPAMs is a problem to be resolved.
On the other hand, amphoretic polyacrylamides are one of the frequently used dry strength aids (see, e.g., JP1049839B), while they almost have no effect of increasing the temporary wet strength.
WO9806898A1 discloses a paper-making process, wherein cationic polymer selected from the group consisting of cationic starch and cationic wet strength resin, and amphoteric polyacrylamide-type polymer is added to the aqueous pulp slurry in order to increase the dry strength of paper, and wherein GPAM can be used as the cationic wet strength resin. Moreover, U.S. Pat. No. 6,294,645B1 discloses a dry-strength system for paper comprising PAE, amphoteric PAM and wet strength resin, wherein GPAM can be used as the cationic wet strength resin. However, the above prior art literatures neither disclose nor suggest the combination use of GPAM and the amphoteric PAM has an effect of increasing the temporary wet strength, not to mention disclose or suggest the influence of the molecular weights of GPAM and the amphoteric PAM as well as the selection of their ratios on the effect of increasing the temporary wet strength.

This patent is subject to a terminal disclaimer.

Process and compositions for paper-making


A method is described of treating a gas stream exhausted from an atomic layer deposition (ALD) process chamber to which two or more gaseous precursors are alternately supplied. Between the process chamber and a vacuum pump used to draw the gas stream from the chamber, the gas stream is conveyed to a gas mixing chamber, to which a reactant is supplied for reacting with one of the gaseous precursors to form solid material. The gas stream is then conveyed to a cyclone separator to separate solid material from the gas stream. By deliberately reacting a non-reacted precursor to form solid material upstream from the pump, reaction within the pump of the non-reacted precursor and a second non-reacted precursor subsequently drawn from the chamber by the pump can be inhibited.

The present invention relates to a method of, and apparatus for, treating a gas stream, and finds particular use in treating a gas stream exhausted from a process chamber in which a pulsed gas delivery system is used to supply gases to the process chamber.
Pulsed gas delivery systems are commonly used in the formation of multi-layer thin films on a batch of substrates located in a process chamber. One such technique for forming thin films on substrates is atomic layer deposition (ALD), in which gaseous reactants, or "precursors", are sequentially delivered to a process chamber to form very thin layers, usually on an atomic-layer scale, of materials on the substrates.
By way of example, a high dielectric constant capacitor may be formed on a silicon wafer using an ALD technique through the sequential deposition of hafnium oxide (HfO2) and aluminium oxide (Al2O3) thin films. HfO2 thin films may be formed by the sequential supply of a hafnium precursor, such as tetrakis(ethylmethylamino)hafnium (TEMAH), and an oxidant, such as ozone (O3), to the process chamber, and Al2O3 thin films may be formed by the sequential supply of an aluminium precursor, such as trimethyl aluminium (TMA), and O3 to the chamber.
In overview, the first precursor delivered to the process chamber is adsorbed on to the surfaces of the substrates within the process chamber. The non-adsorbed first precursor is drawn from the process chamber by a vacuum pumping system, and the second precursor is then delivered to the process chamber for reaction with the first precursor to form a layer of deposited material. In the deposition chamber, the conditions immediate to the substrates are optimised to minimise gas-phase reactions and maximise surface reactions for the formation of a continuous film on each substrate. Any non-reacted second precursor and any by-products from the reaction between the precursors is then removed from the process chamber by the pumping system. Depending on the structure being formed within the process chamber, the first precursor, or a third precursor, is then delivered to the process chamber.
A purge step is typically carried out between the delivery of each precursor, for example by delivering a purge gas, such as N2 or Ar, to the chamber between the delivery of each precursor. The purpose of the purge gas delivery is to remove any residual precursor from the process chamber so as to prevent unwanted reaction with the next precursor supplied to the chamber.
In practice, only around 5% or less of the precursors supplied to the process chamber are consumed during the deposition process, and so the gas drawn from the chamber during the process chamber will, between supplies of purge gas to the chamber, alternately be rich in the first precursor, and then rich in the second precursor.
In convention vacuum pumping systems, the gases drawn from the process chamber enter a common foreline leading to a vacuum pump. In the event that the non-reacted precursors meet within the vacuum pumping system, cross-reaction of the precursors can occur, and this can result in both the deposition of solid material and the accumulation of powders within the foreline and the vacuum pump. Particulates and powders that have accumulated within the pump can effectively fill the vacant running clearance between the rotor and stator elements of the pump, leading to a loss of pumping performance and ultimately pump failure. Periodic pump cleaning or replacement is then required to maintain pumping performance, resulting in costly process downtime and increasing manufacturing costs.
One aim of the present invention is to seek to solve this problem.


A manifold for distributing a fluid. The manifold can be used to distribute a fluid to and from a microvalve. The manifold includes a first plate having a groove formed in one face thereof. A second plate is fixed to the first plate so as to cover the groove to form a fluid passage through the groove. First and second bores are formed through at least one of the first plate and the second plate to form an inlet and an outlet, respectively, of the fluid passage. According to a method of manufacturing, etching the first plate forms the groove. Preferably, an etching process also forms the first and second bores. Also, preferably, the first plate is one of a plurality of plates formed from a single sheet of material. Preferably the sheet of material is a standard sized sheet with locating indicia enabling assembly of the manifold with standard pick and place equipment. Specifically, a method of assembling the manifold includes forming a plurality of first plates from a single sheet; a plurality of second plates from a second sheet; applying a braze material to selected portions of one of the first and second sheets; clamping the sheets together with each of the first plates aligned with a corresponding one of the second plates; heating the first and second sheets, and braze material therebetween, to braze each of the first plates to the corresponding one of the second plates to form a manifold; detaching each manifold from the first and second sheets; and assembling the manifold to a fluid circuit. Optionally, a microvalve is attached to each manifold before the manifold is detached from the first and second sheets.

This invention relates in general to MicroElectroMechanical Systems, and in particular, to a manifold for distributing a fluid to and from a microvalve.
MicroElectroMechanical Systems (MEMS) is a class of systems that are physically small, having features with sizes in the micrometer range. These systems have both electrical and mechanical components. The term xe2x80x9cmicromachiningxe2x80x9d is commonly understood to mean the production of three-dimensional structures and moving parts of MEMS devices. MEMS originally used modified integrated circuit (computer chip) fabrication techniques (such as chemical etching) and materials (such as silicon semiconductor material) to micromachine these very small mechanical devices. Today there are many more micromachining techniques and materials available. The term xe2x80x9cmicrovalve devicexe2x80x9d as used in this application means a complete, functioning valve having features with sizes in the micrometer range, and thus is by definition at least partially formed by micromachining. Furthermore, a xe2x80x9cmicrovalve devicexe2x80x9d, as used in this application includes a microvalve, and may include other components such as a fluid distributing manifold, pressure, temperature, flow or other types of sensors, pumps or other valves of various types. It should be noted that if components other than a microvalve are included in the microvalve device, these other components may be micromachined components or standard sized (larger) components.
Various microvalve devices have been proposed for controlling fluid flow within a fluid circuit. A typical microvalve device includes a displaceable member or valve movably supported by a body. Depending on the type of valve, the valve may be operatively coupled to an actuator for movement between a closed position and a fully open position. When placed in the closed position, the valve blocks or closes a first fluid port that is placed in fluid communication with a second fluid port, thereby preventing fluid from flowing between the fluid ports. When the valve moves from the closed position to the fully open position, fluid is increasingly allowed to flow between the fluid ports.
A manifold can be used to provide an interconnection between the physically minute and normally closely spaced ports of a microvalve and associated macro sized fluid conduits of the system in which the microvalve is installed.
On a macro scale, it is known to individually laminated assemblies, such as valve manifolds, from uniquely styled stamped laminations. Stamped laminations are stacked to the desired thickness and are held together by a variety of welding methods or with pins or bushings. During the set-up process copper rings or slugs are added at pre-determined locations. In a brazing process, the copper liquefies and flows into all joints forming a strong iron-copper alloy bond that is the heart of the process. All the components are bonded into a single unit having strength often greater than one-piece construction. Such a process is performed by HI TecMetal Group of Cleveland, Ohio.
Also on a macro scale, U.S. Pat. No. 3,747,628 to Holster et al. describes making a fluidic function module for use in a system for constructing fluidic logical and/or analog circuits. The module includes a basic part that comprises three plates and a hood that may be made, for example, of a suitable synthetic material by injection molding. Clamped between them are three diaphragms that provide airtight seals. The plate is provided with an annular valve seat that cooperates with a disc-shaped valve made of a resilient material. In its lower position shown in the drawing the valve cooperates with the annular valve seat, but in its upper position it is capable of cooperating with a valve seat in the plate. The diaphragm through an annular part of smaller thickness is integral with a movable part that has a specially shaped cross-section, the part being referred to as the movable part of the circuit element. A fluidic function module consists of a basic part, a gasket, and a connecting part in the form of a xe2x80x9cuniversal connecting platexe2x80x9d. The universal connecting plate is made of a synthetic material, for example by injection molding, so that the product may simply be manufactured by mass production methods. The universal function connecting plate is provided in both of it""s surfaces with grooves and bores which together form a standard passage system. When the basic part is assembled with the gasket and the universal connecting plate, the combination forms a fluidic module for constructing fluidic circuits which, depending upon the intended use, comprise one or more fluidic modules for performing logical analog and/or combined operations, the function module comprising at least firstly a basic part accommodating a plurality of individual fluidic circuit elements and secondly a function connecting part in the form of the universal connecting plate in which passages have been formed which interconnect the various input, output, air supply and vent passages of the individual circuit elements of the basic part in the appropriate manner, so that the assembly of basic part and connecting part forms a function module which may have, for example, an AND, an OR, a universal or a storage function. Adapting the universal function connecting plate to an intended function of a function module is achieved by removing readily removable partitions of the function connecting plate from between specific passages of the standard passage system on opposite sides of the universal function connecting plate. The partitions are removed by drilling between the passages.
The invention relates to a manifold for distributing a fluid. The manifold can be used to distribute a fluid to and from a microvalve. The manifold includes a first plate having a groove formed in one face thereof. A second plate is fixed to the first plate so as to cover the groove to form a fluid passage through the groove. First and second bores are formed through at least one of the first plate and the second plate to form an inlet and an outlet, respectively, of the fluid passage. Preferably, the face of the first plate or the second plate opposite the face with the grooves formed therein has a solderable pad formed on at least a portion thereof. According to a method of manufacturing, etching the first plate forms the groove. Preferably, an etching process also forms the first and second bores. Also, preferably, the first plate is one of a plurality of plates formed from a single sheet of material. Preferably the sheet of material is a standard sized sheet with locating indicia enabling assembly of the manifold with standard pick and place equipment. Specifically, a method of assembling the manifold includes forming a plurality of first plates from a single sheet; a plurality of second plates from a second sheet; applying a braze material to selected portions of one of the first and second sheets; clamping the sheets together with each of the first plates aligned with a corresponding one of the second plates; heating the first and second sheets, and braze material therebetween, to braze each of the first plates to the corresponding one of the second plates to form a manifold; detaching each manifold from the first and second sheets; and assembling the manifold to a fluid circuit. Optionally, a microvalve is attached to each manifold before the manifold is detached from the first and second sheets.
Various other objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.


A rod puller apparatus and method includes an extended lever. A roller pad is connected to the extended lever. A releasable grab attachment is connected to the roller pad. In a preferred embodiment, a foot leverage platform is connected to the roller pad. In a further preferred embodiment, a replaceable guide roller is provided so as to accommodate rods of various diameters. Other grab attachments are provided for rods with mushroomed heads and for square posts and/or metal fence posts.

Many situations exist wherein rods, posts, pilings and the like are driven into the ground to serve a temporary purpose. By way of example only, and not limitation, in the construction industry it is necessary for steel rods, many feet in length, to be sunk into the ground at the construction site. The rods can serve any purpose, but, for example again, often are used as electrical grounding devices. Certainly, many other needs are served by such temporary rods, such as for surveying purposes, locating cement car stops in parking lots, metal, wood, and cement fence and sign posts and the like.
In any event, once installed, it is often necessary to remove these "rods". This has proven to be a difficult, time-consuming, and destructive process. That is, for example only, heretofore, the removal of long, metal, rods which have been driven deep into the earth, often results in the rods being bent beyond reusable form. One prior art method is to tie a chain to the rod and use a back hoe, or the like, to yank the rod out of the ground. Even if this is successful, the rod is generally so bent and deformed as to be of no possible further use.
In some cases, the rod has been driven into ground so hard and to such a depth that removal is, for all practical purposes, impossible. In this case, the prior art solution is to cut the rod off as close to the ground level as possible and then drive the stub below grade and leave the rest of the rod forever buried at the construction site.
By way of further example, these metal rods are generally made of steel, are eight to ten feet long, and vary in diameter from one-half to three-quarter inches. Additionally, utility companies, construction firms, and the like, invest a large amount of money in maintaining a supply of such rods. Companies use other rods as well such as four foot long curb pins and two to four foot long grading stakes. Any rods, whether metal, wood, cement, or the like, that can be reclaimed and reused helps reduce the costs to such companies.
Thus, there is a need in the art for providing an apparatus and method for pulling sunken rods or posts that leaves the rods and posts intact and reusable.


The present driver for fasteners such as nails, screws and the like is provided with a separator member operatively located between the ejector channel and a fastener supply magazine. The separator member takes up a fastener arresting position in which the separator member reaches between the shafts of two fasteners and a retracted position in which the separator member releases a fastener for movement into the ejector channel. The separator member cooperates with a holding device which holds a fastener in the ejector channel after release by the separator member and prior to the driving stroke. The holding device may comprise two permanent magnets.

The present invention relates to an apparatus for driving fasteners such as nails, screws or the like having a shaft. The driving apparatus includes a discharge or ejector channel in which a power driven driver rod is guided between a rest position and a driving position. A magazine holding the fasteners is operatively connected to the ejector channel. A separator device is arranged between the ejector channel and the magazine.
Driving tools of this type are used for driving of bulk type fasteners such as nails, screws, spikes and so forth. These fasteners are made ready for use in the above mentioned magazine connected to the driving apparatus. German Patent Publication (DE-OS) No. 2,511,023 corresponding to U.S. Pat. No. 3,893,610 discloses an apparatus of this type in which the magazine is inclined relative to the ejector channel in such a manner that the nails enter into the ejector channel under the force of gravity. Besides, the central plane of the magazine intersects the longitudinal axis of the ejector channel so that the first nail initially cannot enter into the ejector channel. Only a separator plate operated by an air pressure piston tilts the first nail in such a manner, that it may enter into the ejector channel where it is immediately thereafter driven into the work piece by a driver rod. The separation and feeding of the first nail as well as the punch stroke of the driver rod is accomplished by means of an air pressure sequence control having several valve functions which take place after actuation of the trigger valve.
However, in the known driving tool merely a relatively slow stroke or driving sequence may be accomplished due to the multiple step air pressure sequence control which requires respective valve and piston movements. Such a slow driving sequence is disadvantageous or rather incompatible with an expedient manufacturing operation. The driving sequence becomes even slower, when the valves are dirty or when the lubricating oil becomes rather viscous, for example, due to cold external temperatures. Another disadvantage of the prior device is seen in its substantial price and weight caused by additional valves and pistons. Moreover, the known apparatus is capable of driving nails of the best quality only. Such nails are necessary for a trouble free functioning of the nail supply by means of tilting. Moreover, since the nails are supplied by gravity it is not possible to use the known apparatus for driving nails in an overhead fashion.


A thin durable decorative coating is applied to a concrete substrate such as a floor by applying a 0.1 mm coating of runny cement-plus-fines (water:cement=1:1) to the substrate. Capillary suction by the substrate very rapidly dewaters the coating, which is compacted by atmospheric pressure and matures to form an inseparable coating on the substrate. The fines may include colourings, mica or other additives to enhance the final appearance.

Concrete and cementitious materials generally are a compromise between the conflicting needs to achieve workability for ease of placing and good compaction, usually attained by adding more water, and to achieve strength by reducing the water content and water:cement ratio and increasing the content of dimensionally stable fillers (aggregate). It is particularly important to have a free flowing material when this has to be spread onto a surface, particularly with thin surface layers. Shrinkage is a fundamental problem with cementitious materials especially on site and is frequently the cause of premature failure and unsatisfactory performance due to self-induced cracking and fracture. Shrinkage occurs mainly in relation to the cement particles, due both to drying and chemical, autogenous shrinkage. To reduce shrinkage requires the inclusion of sufficient quantities of dimensionally stable fillers to reduce the quantity of the cement paste. With conventional concrete it is possible to reduce the shrinkage caused by the liquid cementitious phase by incorporating sufficient larger particles of dimensionally stable aggregate, and because the surface area of this larger Filler is limited the water demand to achieve workability and the water:cement ratio may not be too adversely affected. This certainly cannot be done with thin cementitious coatings (too thin to accommodate such larger particles).
It is generally accepted that cementitious materials must be cured and that the premature loss of water (even by evaporation) should be prevented, and, for this reason, they should not be applied to surfaces having a high suction as this removes the water required for hydration and exacerbates shrinkage cracking. Thus, according to the basic technical reference manual `Properties of Concrete`, edited by Professor Neville, "Loss of water by evaporation From the surface of the concrete or by suction from dry concrete below aggravates the plastic shrinkage and can lead to surface cracking . . . Placing concrete on a dry subgrade should be avoided . . . The object of curing is to keep the concrete saturated, or as near saturated as possible, until the originally water filled space in the fresh cement paste has been filled to the desired extent by the products of hydration of the cement . . . The loss of strength due to inadequate curing is more pronounced in thinner elements."
To overcome the problems of shrinkage cracking with thinner cementitious materials which require reasonable strength, such as flooring screeds, it is common to use semi dry mortar mixes. In these the water content is kept down to a minimum and the material is not saturated with water (i.e. there is no liquid cementitious phase), as in the conventional use of on-site concrete. With the use of such semi dry materials the placing and compaction are difficult and it is not possible to achieve a smooth dense surface finish which is often desirable.
The problems of high shrinkage of thin cementitious materials are discussed in International PCT Publication No WO91/12218, and the means of overcoming these is by placing the materials dry so that the solid particles thereof are touching, and then adding the water for hydration, whereby the initial high shrinkage of wet mixed materials resulting from the loss of water separating particles is avoided.
In this case, it is not possible to achieve a coloured surface as the initial surface application of the water tends to wash the fine materials, cement and colour, off the surface and into the body of the material, nor is a very smooth surface practicable.
Although the foregoing two methods allow a stronger mix to be employed in thinner sections than are possible with conventional concrete, the minimum practical thickness is still limited, in the case of semi dry mixes to about 50 mm and in the case of WO91/12218 to about 20 mm.
Cementitious materials as explained above are not regarded as suitable for thin dense smooth surfaces as this would require a high cementitious and water content and this, particularly when combined with rapid drying, results in cracking and premature failure.
Non-cementitious materials such as epoxy resins can be employed to produce a hard, dense, smooth and coloured surface on floors and similar surfaces, but these are relatively expensive and care is required in their use as they can produce toxic reactions.
Where conventional wet placed concrete is employed, a smooth and if required coloured surface can be achieved but this does involve delay/whilst the material sets. In addition, the surface is generally weaker than the main body of the material due to the settlement of the larger aggregates and the consequent concentration of finer particles on the surface which is made worse by the bleed water which rises and increases the water:cement ratio on the surface. The surface is, of course, generally the most vulnerable to attack and this weak surface mortar phase is frequently the cause of premature failure.

British Technology Group Inter-Corporate Licensing Limited


A material dispenser system for allowing convenient unloading, loading and dispensing of a spool of elongate material. The material dispenser system includes a plurality of prongs formed for rotatably receiving a spool of material, a main body receiving the prongs, and a handle attached to the main body. The prongs are comprised of a resilient material for allowing the distal portions thereof to be forcibly contracted thereby allowing the spool of material to be unloaded and a replacement spool to be loaded. The prongs each have a flanged portion that extends outwardly thereby retaining the spool positioned upon the prongs.

1. Field of the Invention
The present invention relates generally to elongate material dispensers and more specifically it relates to a material dispenser system for allowing convenient unloading, loading and dispensing of a spool of elongate material.
2. Description of the Related Art
Elongate material dispensers have been in use for years. Conventional elongate materially dispensers are formed for receiving and dispensing a spool of material such as barricade tape, flagging tape, string, rope, wire and other elongate materials. The BEN MEADOWS COMPANY manufactures a barricade tape dispenser that is comprised of a complex structure which is difficult to load and unload a spool of material. There are other products on the market that receive and dispense elongate material upon a spool, but they are relatively difficult to load and unload.
While these devices may be suitable for the particular purpose to which they address, they are not as suitable for allowing convenient unloading, loading and dispensing of a spool of elongate material. Conventional material dispensing devices are difficult to load and unload with a spool of material.
In these respects, the material dispenser system according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of allowing convenient unloading, loading and dispensing of a spool of elongate material.


A semiconductor device includes a first input terminal receiving a termination resistance control signal, and a termination resistance circuit that is able to be controlled to be turned on or off by the termination resistance control signal. The termination resistance circuit is turned off, irrespective of a level of said termination resistance control signal when the semiconductor device outputs data in response to a read command.

There have been remarkable increases in capacity and speed of a memory system that uses semiconductor memory devices such as dynamic RAMs. In the memory system on which DDR SDRAMs (Double Data Rate Synchronous DRAMs) are mounted in particular, internal operations of the semiconductor memory devices are pipelined, and commands that have been supplied from an outside in synchronization with a clock are sequentially executed. Together with the sequential execution of the commands, it is arranged that data transfer is performed between a DDR SDRAM and the memory controller at a rate twice as the frequency of the clock, thereby implementing a high-speed system operation. In the DDR SDRAM or the like, a DLL (Delay Locked Loop) circuit is employed. Then, an internal circuit is operated in synchronization with the clock supplied from the outside. High-speed data transfer is thereby implemented. In the DDR SDRAM after a DDR2 in particular, a termination resistance is included in each of data input/output terminals such as a DQ terminal and a DQS terminal. Then, a control signal is supplied to an ODT terminal of the DDR SDRAM from the memory controller to control turning on or off of the termination resistance, thereby reducing reflection from the data input/output terminal. A high data transfer is thereby implemented.
FIG. 1 is a configuration diagram of an overall memory system of a related art. FIG. 1 is the memory system for reading and writing of 64 bits in parallel. A semiconductor memory device 101 is used for reading and writing of eight bits in parallel. Eight semiconductor memory devices 101 are connected in parallel to perform reading and writing of 64 bits in parallel. In the memory system in FIG. 1, a configuration is assumed in which two ranks of the semiconductor memory devices 101 are respectively mounted on two DIMMs (Dual Inline Memory Modules). That is, the memory system is formed of the semiconductor memory devices of a total of four ranks which are indicated by DIMM1 Rank-1, DIMM1 Rank-2, DIMM2 Rank-1, and DIMM2 Rank-2. Each rank is further formed of the eight semiconductor memory devices 101. A total of 4 ranks*8=32 semiconductor memory devices 101 are mounted. FIG. 1 illustrates only three of the eight semiconductor memory devices 101 connected in parallel. Signals that control these 32 semiconductor memory devices 101 are supplied from the memory controller 102, and data input/output is performed between the memory controller and each of the semiconductor memory devices 101.
Referring to FIG. 1, the memory controller 102 is directly connected to each semiconductor memory device 101. The memory system may include a so-called Registered DIMM or a Fully Buffered DIM (FBDIMM) in which a PLL or a buffer register is arranged between the memory controller 102 and the semiconductor memory device 101 for each DIMM, and timing synchronization with the memory controller is sought for each DIMM. The memory controller 102 may be an LSI having a function dedicated for memory control. Alternatively, a CPU may directly control the memory. Alternatively, the memory controller 102 may be formed of a plurality of LSIs.
Referring to FIG. 1, reference characters ADR and CMD respectively indicate an address signal and a command signal, which are connected in common to the semiconductor memory devices 101 of each rank, from the memory controller 102. The command signal CMD includes a row address strobe signal/RAS, a column address strobe signal/CAS, and a write enable signal/WE. Signals DQ0 to DQ63 are bidirectional data input/output signals used for transfer of read/write data or the like between the memory controller 102 and the semiconductor memory devices 101. It is assumed that each semiconductor memory device 101 is used for input/output of eight bits in parallel. Thus, the eight semiconductor memory devices 101 are connected in parallel in order to accommodate 64 bits of the signals DQ0 to DQ63. These data input/output signals DQ0 to DQ63 are also connected in common to each rank. DQS0 and /DQS0 signals, DQS1 and /DQS1 signals, DQS2 and /DQS2 signals, DQS3 and /DQS3 signals, DQS4 and /DQS4 signals, DQS5 and /DQS5 signals, DQS6 and /DQS6 signals, and DQS7 and /DQS7 signals are respectively differential data strobe signals. Each pair of the differential data strobe signals is transferred to a corresponding one of the semiconductor memory devices 101 from the memory controller 102 at a time of a write operation, and is transferred to the memory controller 102 from the corresponding one of the semiconductor memory devices 101 at a time of a read operation. These DQS and /DQS signals are bidirectional input/output signals. The data strobe DQS and /DQS signals output by the semiconductor memory device 101 at the time of the read operation are synchronized with a change point of read data. Thus, when the DQS and /DQS signals are used as the strobe signals on the side of the memory controller 102, the phases of the DQS and /DQS signals are deviated at a timing in which a data signal can be latched. These data strobe signals DQS0 to DQS7 and /DQS0 to /DQS7 are also connected in common to each rank of the semiconductor memory devices. However, an independent pair of the DQS and /DQS signals is connected to each of the eight semiconductor memory devices 101 of each rank connected in parallel.
Clock signals CK0 to CK3 and /CK0 to /CK3, clock enable signals CKE0 to CKE3, chip select signals /CS0 to /CS3, and embedded termination resistance control signals ODT0 to ODT3 are signals that are output from the memory controller 102 to the semiconductor memory devices 1. Different ones of these signals that are independent are output for each rank. The clock signals CK0 to CK3 and /CK0 to /CK3 are signals that are supplied to the semiconductor memory devices 1 as system clocks. A command for a read, a write, or the like supplied from the memory controller 102 to the semiconductor memory device 101 is supplied in synchronization with a corresponding pair of the system clocks. The clock enable signals CKE0 to CKE3 are signals each of which determines whether the corresponding clock CK is valid or invalid. When the clock enable signal CKE is high at a rising edge of the corresponding clock CK, the subsequent rising edge of the corresponding clock CK is valid. Edges of the corresponding clock CK other than the subsequent rising edge are invalid. When each of the chip select signals /CS0 to /CS3 is low, input of a command is valid. When each of the chip select signals /CS0 to /CS3 is high, the command is ignored. Operation, however, is continued. By supplying the command to the semiconductor memory device 101 of an arbitrary one of the ranks using this chip select signal, a selective access can be made. When values of termination resistances inside the respective memory devices 1 are not infinite, the embedded termination resistance control signals ODT0 to ODT3 can control turning on or off of the termination resistances. When the embedded termination resistance control signals ODT0 to ODT3 are high, the termination resistances are turned on. When the embedded termination resistance control signals ODT0 to ODT3 are low, the termination resistances are turned off.
With respect to routing of data buses (for the DQ signals, DQS signals) from the memory controller to the semiconductor memory devices 101 in FIG. 1, the routing is performed using a so-called fly-by (FLY-BY) topology. In this topology, the DIMM1s are mounted at far ends of lines extending from the memory controller 102 and the DIMM2s are mounted midway from the memory controller 102 to the DIMM1s so that no stub (stub, or unterminated section of line) occurs even when only the DIMM1s are mounted and no DIMM2s are mounted. Routing by the fly-by topology is to prevent signal reflection from the stub when only the DIMM1s are mounted without mounting the DIMM2s.
Next, an example of preferable setting of termination resistances when the semiconductor memory device 101 is a DDR3 SDRAM is shown in FIG. 2. FIG. 2 assumes a case (2R/2R) where DDR3 SDRAMs having two ranks of the DIMM1s and two ranks of the DIMM2s have been mounted, a case (2R/1R) where DDR3 SDRAMs having two ranks of the DIMM1s and one rank of the DIMM2 have been mounted, and a case (1R/1R) where DDR3 SDRAMs having one rank of the DIMM1 and one rank of the DIMM2 have been mounted. FIG. 2 shows each of write and read (WRITE, READ) commands supplied from the memory controller 102, the DIMM to be accessed by the write or read command and the rank of the DIMM, a termination resistance value of the memory controller 102 when the write or read command is executed, and a termination resistance value of each rank of each DIMM mounted on a board in each case. Termination resistance values are set in termination resistance value specifying registers of the semiconductor memory devices 101 by the memory controller 102 in advance.
The DDR3 SDRAM has a dynamic ODT function. Thus, the DDR3 SDRAM includes a write-command execution time termination resistance value specifying register and a nominal termination resistance value specifying register. The write-command execution time termination resistance specifying register specifies a termination resistance value when the write command is executed. The nominal termination resistance value specifying register specifies a termination resistance value except when the write command is executed. When the dynamic ODT function is selected, the termination resistance value can be changed between a time when the write command is executed and a time except when the write command is executed. That is, when the dynamic ODT function is used, whether to turn off or turn on the termination resistance is controlled by the ODT terminal. When the termination resistance is turned on, different resistance values of the termination resistance can be specified between the time when the write command is executed and the time except when the write command is executed. Referring to FIG. 2, different resistance values are set as the termination resistance value of the rank targeted for execution of the write command and the termination resistance value not targeted for execution of the write command, using the dynamic ODT function. When the termination resistance value setting as shown in FIG. 2 is performed, signal reflection can be appropriately prevented.
Specifications of the DDR3 SDRAM including the dynamic ODT function are described in Non-patent Document 1 (on pages 89 to 105).
Patent Document 1 describes an example of termination resistance setting similar to that in FIG. 2.
[Patent Document 1] U.S. Pat. No. 7,342,411
[Non-patent Document 1] JEDEC STANDARD DDR3 SDRAM Specification, JESD79-3B, April, 2008, JEDEC Solid State Technology Association (JEDEC SOLID STATE TECHNOLOGY ASSOCIATION), pages 37, 89 to 105

Memory system, semiconductor memory device, and wiring substrate, the semiconductor memory device including termination resistance circuit or control circuit


A memory cell of EEPROM having a floating gate, a control gate, a drain region, and a source region is formed on a silicon substrate. Thereafter, a BPSG film (interlayer insulating film) covering the memory cell is formed by CVD. After a wire including a bit line, an SiON film (passivation film), covering the silicon substrate and serving as an uppermost layer, is formed on an upper portion of the silicon substrate. Thereafter, annealing is performed to discharge water in the BPSG film to an outer portion of an LSI. The annealing is performed under a condition satisfying the following equation of EQU t.gtoreq.7.86.times.10.sup.-11.times.L.sup.2.times.exp (9115/T). where t is anneal time (minutes), L is a thickness (nm) of the passivation film, and T is anneal temperature (absolute temperature). Thereby, an amount of electronic trap in a gate oxide film of the transistor can be reduced.

The present invention relates to an anneal technique for reducing an amount of electronic trap in a gate oxide film of a transistor, which is applied to a semiconductor device using an insulating film, which is formed by a chemical reaction of gas as material, as a passivation film.
A passivation film, which is formed of SiO.sub.2, Si.sub.3 N.sub.4, or SiO.sub.x N.sub.y (x, y denote arbitrary positive numbers each showing an atomic ratio), is often used in LSI. As an interlayer insulating film of a lower layer of the passivation film, there is used an insulating film of silicon glass series such as PSG, BPSG, ASG, BSP, CSG, etc.
The insulating film used as a passivation film has low hygroscopicity and water permeability, and the insulating film used as an interlayer insulating film has a property of easily absorbing water. The interlayer insulating film contains water permeated mainly in manufacturing the interlayer insulating film.
Water molecules in the interlayer insulating film is dispersed in the interlayer insulating film by heat generated in depositing the passivation film. At this time, water molecules neither transmit through the passivation film nor disperse to the outer portion of the semiconductor device. Water molecules disperse into the gate oxide film of the transistor in the semiconductor device. The reason is that the passivation film has a property of permeating water with difficulty (low water permeability).
Water molecules permeated into the gate oxide film of the transistor cause electronic trap in the gate oxide film so as to deteriorate a hot carrier life of the transistor.
To solve the above problem, for example, there is an anneal method for the purpose of removing water of the interlayer insulating film before depositing the passivation film. For example, this method is a well-known technique as disclosed in Japanese Patent Application KOKAI Publication No. 61-219141.
However, in this method, the anneal process must be performed in a cleaning room since the annealing is performed before depositing the passivation film. As a result, the manufacturing cost is increased.
Japanese Patent Application KOKAI Publication No. 61-219141 also discloses removal of water of the interlayer insulating film in a DRAM (dynamic random access memory). To reduce a failure ratio of pose-failure of DRAM, anneal temperature and time may be set to 350.degree. C. and one hour before forming the passivation film (plasma nitrogen film) as described in the above publication.
However, even if the conditions disclosed in the above publication are directly applied to a nonvolatile semiconductor memory such as EEPROM, the electronic trap in the gate oxide film of the memory cell transistor cannot be reduced to an extent that sufficient reliability can be obtained.
In other words, in the nonvolatile semiconductor memory such as EEPROM, it is necessary to review annealing temperature and time in more detail.
Thus, conventionally, the passivation film is formed to prevent water and impurity materials from being permeated from the outer portion of the semiconductor device (LSI). Due to this, the passivation film is formed of material having low hygroscopicity and water permeability. Since the water permeability of the passivation film is low, water of the interlayer insulating material disperses into the gate oxide film of the memory cell transistor to cause electronic trap.

Anneal technique for reducing amount of electronic trap in gate oxide film of transistor


A polyimide obtained by reacting an acid dianhydride such as catechol bistrimellitate dianhydride, bisphenol A bistrimellitate dianhydride, etc. with a diamine such as 4,4'-diamino-3,3',5,5'-tetraisopropyl-diphenylmethane, etc. has high solubility in organic solvents and good moldability at low temperatures, and can provide a thermosetting resin composition together with a polymaleimide.

This invention relates to novel polyimides having high solubility in organic solvents and excellent low-temperature moldability, a process for preparing such polyimides, and thermosetting resin compositions containing said polyimides, showing excellent properties even after low-temperature curing and useful as an adhesive, laminating material, molding material and the like.
Polyimide resins have excellent heat resistance, but many of them are poor in moldability because of insufficient solubility and fusibility. Therefore, for molding a film or other products from a polyimide, it has been necessary to perform molding by using a varnish prepared by dissolving a polyamide acid, which is a precursor of polyimide, in an organic solvent, and then conduct an imidation treatment on the molded product. However, a varnish comprising a polyamide acid is lowered in molecular weight when hydrolyzed, so that it must be kept at a low temperature. The above-said prior art molding process also had problems such as precipitation of the resin due to moisture absorption since the solvents usually used in said process are hydroscopic, formation and retention of voids in the molded product due to generation of an aqueous condensate in the course of imidation after molding of a desired product such as film, and unapplicability to a base material with poor heat resistance since use of a high temperature above 300.degree. C. is required for the imidation treatment.
Various polyimides having a softening point and therefore capable of molding have been developed and proposed for solving said prior art problems.
For instance, Japanese Patent Unexamined Publication No. 62-10051 discloses a polyimide composed of a diamine and pyromellitic acid, which is represented by the formula: ##STR1## wherein X' stands for C.dbd.O or SO.sub.2. This polyimide has a softening point and is capable of molding, but because of its too high softening point, molding must be carried out at a temperature over 300.degree. C. Also, this polyimide is scarcely or only slightly soluble in organic solvents, so that for molding a thin film therefrom, it is necessary to first form a film by using a varnish prepared by dissolving a polyamide acid, which is a precursor of said polyimide, in an organic solvent and then imidize the film compound by heating at a high temperature. Thus, this polyimide still involves the problems such as mentioned above.
The polyimides soluble in organic solvents have also been developed for overcoming said problems. For example, the polyimides composed of 4,4'-methylenebis(2,6-dialkylanyline) and acid dianhydrides such as biphenyltetracarboxylic acid dianhydride, pyromellitic acid dianhydride, etc., disclosed in U.S. Pat. No. 4,851,505 (Japanese Patent Unexamined Publication No. 1-263116) and U.S. Pat. No. 4,935,490 (Japanese Patent Unexamined Publication No. 1-263117) are soluble in N-methylpyrrolidone and m-cresol. These polyimides, however, have as high a glass transition point as over 400.degree. C. and require a high temperature for molding.
Also, Japanese Patent Examined Publication No. 43-19814 (German Offenlegungsschrift No. 1,520,012) discloses polyimides obtained from paraphenylene-bis(trimellitate) dianhydrides and diamines such as benzidine, 4,4'-diaminodiphenyl ether, etc., and Japanese Patent Examined Publication No. 43-5911 teaches that bisphenol A bistrimellitate dianhydrides can be used as a starting material for the preparation of polyimides (no example of preparation of polyimide by using said substance is shown). Any of the polyimides disclosed or mentioned in these patent publications is higher than 350.degree. C. in softening point, and no teaching is made on their solubility in the organic solvents with small polarity.
U.S. Pat. No. 4,681,928 (Japanese Patent Unexamined Publication No. 60-258225) discloses the polyimides obtainable by reacting 1,4-bis(p-aminocumyl)benzene and a dianhydride of an aromatic or aliphatic acid, and it is verified that such polyimides are soluble in N-methylpyrrolidone. It is also taught that these polyimides are fusible (the glass transition point being around 200.degree. C.). 2,2-bis[4,4-(3,4-dicarboxyphenoxy)phenyl]propane, etc., are mentioned as examples of said acid dianhydride. Paraphenylene-bis(trimellitate)dianhydride is also referred to as an example of said acid dianhydride, but there is shown no example of preparation of polyimide by using said compound. These polyimides are insoluble in toluene and ethylene glycol dimethyl ether which are smaller in polarity than N-methylpyrrolidone. No mentioned is made of the solubility of said polyimides in the organic solvents with small polarity, such as dioxane, tetrahydrofuran and methylene chloride.
Further, Japanese Patent Unexamined Publication No. 2-11633 discloses a process for preparing a polyimide by reacting a diamine having 6-member rings in the main chain, such as the diamine of the afore-shown formula A, with a specific acid dianhydride (e.g. bisphenol A bistrimellitate dianhydride). The polyimides prepared according to this process are low in softening point and also improved in solubility in organic solvents in comparison with the polyimides disclosed in Japanese Patent Unexamined Publication No. 62-10051. Regarding solubility in organic solvents, the polyimides obtained according to the process disclosed in Japanese Patent Unexamined Publication No. 2-11633 are soluble in N,N-dimethylformamide, dioxane, etc., but insoluble in toluene and diethylene glycol dimethyl ether. Also, said diamines are not only difficult to produce with high purity but also expensive, so that their industrial use is disadvantageous in terms of economy.
As noted from the foregoing, it has been very difficult to produce the polyimides which are low in softening point and have sufficiently high solubility in organic solvents.
On the other hand, the resin compositions prepared by adding polymaleimides to polyamide acids or polyimides have a wide scope of use as the cured products of said resin compositions are tough and high in heat resistance. Said resin compositions are used, for instance, for the preparation of adhesives, varnish for printed wiring boards, and prepregs. Prepregs can be used for producing the printed wiring boards, etc.
U.S. Pat. No. 4,362,826 discloses a thermosetting resin composition comprising a polyamide acid obtained from 4,4'-diaminodiphenyl ether and pyromellitic acid dianhydride and a bismaleimide compound. It is shown that this composition can be worked into a cured film (film supported on a substrate) by cast coating said composition onto a substrate such as a copper foil and drying the coat with heating.
However, the resin compositions prepared by adding bismaleimides to polyamide acids such as mentioned above are required, when cured, to not only react a polymaleimide but also imidate the polyamide acid. This necessitates heating at a temperature above 300.degree. C. for curing, so that these compositions can not be applied to a base material with low heat resistance. Also, since an aqueous condensate is generated concomitant with imidation of the polyamide acid, formation of the voids is unnegligible although it is suppressed to some extent by the presence of polymaleimide. Especially, when said composition is interposed between a Kapton film (polyimide film) and a metal foil such as copper foil and cured for bonding them, formation of the voids causes an excessive reduction of adhesive force.
It is well known in the art that the polyimides obtained by imidating the amide acids such as disclosed in U.S. Pat. No. 4,362,826 are insoluble in organic solvents and also infusible. Further, no example of polyimides soluble in organic solvents is shown in this U.S. patent.
Regarding the compositions containing a polyimide and a polymaleimide, U.S. Pat. No. 3,842,143 discloses a composition prepared by adding a polymaleimide to an amino-terminated low-molecular weight polyimide obtained by reacting a tetracarboxylic acid dianhydride with an excess of a diamine. However, in case of using such a low-molecular weight polyimide, the film obtained from said composition lacks flexibility,and no self-supporting film can be obtained. In this U.S. patent, no mention is made of a composition having enough flexibility to form a self-supporting film nor is shown any polyimide to be used for such a composition.
U.S. Pat. No. 4,985,509 (Japanese Patent Application Unexamined Publication No. 62-30112) discloses a composition containing a polyimide obtained from 3,3',4,4'-benzophenontetracarboxylic acid dianhydride, bis[4-(3-aminophenoxy)phenyl]sulfone and if necessary 2,4-diaminotoluene and a polymaleimide and states that this composition has good film-forming properties and the film made therefrom shows excellent adhesiveness. It is also taught that said polyimide is soluble in a toluene/m-cresol mixed solvent. However, the polyimide disclosed in this U.S. patent is insoluble in the organic solvents with small polarity such as tetrahydrofuran, dioxane and methylene chloride. Also, the composition disclosed therein is fusible and cured at a relatively low temperature (250.degree.-275.degree. C.) and shows excellent adhesiveness, but this composition is deteriorated in its properties when cured at a temperature lower than 230.degree. C.
In the afore-mentioned Japanese Patent Unexamined Publication No. 62-10051, U.S. Pat. Nos. 4,851,505, 4,935,490, Japanese Patent Examined Publication No. 43-18914 (DE-OS 1,520,012), Japanese Patent Examined Publication No. 43-5911, U.S. Pat. No. 4,681,928 and Japanese Patent Unexamined Publication No. 2-11633, no disclosure is made of the compositions containing a polyimide and a polymaleimide.
As understood form the above, there is yet known no composition which contains a polyimide and a polymaleimide and which shows the excellent characteristics when cured at a satisfactorily low temperature and also has good film-forming properties. Nor is known a polyimide suited for use as a component of such a composition.

Polyimides and thermosetting resin compositions containing the same


A system and method for securing an edge zone in a space, while not restricting normal activities in the space, is provided. The system and method comprises an infrared detection device and a data processing means. The infrared detection device monitors a space using two or more fields of view. Some of the fields of view cover an edge zone of the space, while the rest of the fields of view cover an adjacent zone to the edge zone. The infrared detection device produces a signal when one or more infrared sources, such as human beings, enter one of its fields of view, in which the signal is unique for identifying the field of view being entered. The data processing means processes the signals from the infrared detection device for securing the edge zone with either intrusion detection or escape detection. The data processing means produces an alarm signal when an intrusion or escape is detected, but does not produce such a signal for normal activities in the monitored space, including the edge zone.

Home and building break-ins cause big property loss almost every day. Moreover, when an intruder has a surprise encounter with an occupant in a house or building, the intruder or the occupant may act impulsively causing injuries or even deaths. Typical existing security systems rely on contact sensors, glass breakage sensors, vibration sensors, and motion sensors for detecting an intrusion.
A contact sensor works only when the window or door that it monitors is opened by the intruder, while an intruder may just break or even cut the glass on the window or door for an entrance. A glass breakage sensor or a vibration sensor is designed for detecting such an intrusion.
However, false alarms and false negatives are common complaints for glass breakage sensors and vibration sensors. Daily activities and bad weather may trigger such sensors. For example, clashing of dishes may trigger a glass breakage sensor, opening or closing a window or door may trigger a vibration sensor, and a thunder may trigger a vibration sensor too. The common method to deal with false alarms for such types of sensors is to lower their sensitivity, but lowered sensitivity results in those sensors not responsive to delicate intrusions in which intruders skillfully breaks or cuts the window or door.
The last defense in a typical existing security system is motion sensors, which are usually infrared detection sensors. When the other sensors fail to detect an intrusion, the intruder is expected to be detected by the motion sensors installed in the house or building. However, to avoid false alarms on an occupant, the motion sensors are bypassed when there are occupants in a house or building. Therefore, when an occupant is in a house or building, especially when the occupant is not vigilant, such as in sleep, in shower, playing video games, or watching TV, an intruder can circumvent an existing security system and put the occupant in great danger.
U.S. Pat. No. 7,916,018 B2, issued to Eskildsen et al. on Mar. 29, 2011, discloses a system using a motion sensor to detect whether a contact sensor at a window or door is triggered by an occupant opening the window or door, but the system cannot detect an intruder who either enters through an opened window or door or breaks a window or door for an entrance. U.S. Pat. No. 4,963,749, issued to McMaster on Oct. 16, 1990, describes systems doing one-direction infrared detection, but an occupant still triggers the systems when the occupant moves in the direction of intended detection. U.S. Pat. No. 6,348,863 B1, issued to Krubiner et al. on Feb. 19, 2002, claims systems detecting the direction of a movement for identifying an intrusion through a window or door. However, the timing complexity in the systems introduces detection delay and unreliability.

Constant infrared detection for security


A semiconductor device includes a silicon layer. The silicon layer includes a lower silicon layer and an upper silicon layer which is formed on the lower layer. A concentration of impurities in the upper silicon layer is higher than that of the lower silicon layer.

The present invention relates to a semiconductor device and method of manufacture, and particularly, the present invention relates to a semiconductor memory device having a capacitor which includes a silicon layer having introduced impurities therein, and to a method of manufacturing such a semiconductor memory device.
In a semiconductor device, a silicon layer is used in various portions, such as a conductive layer, a resistant element, a gate electrode of transistor, and a capacitor of a memory cell. As is well known, in a Dynamic Random Access Memory (DRAM), a capacitor of the memory cell is comprised of a silicon layer. The silicon layer composes a storage electrode and a cell-plate electrode of the capacitor. A method for manufacturing such capacitors of the DRAM is shown in Japanese Laid Open Patent xe2x80x9cToku-Kai-Hei 7-235616xe2x80x9d, which was published on Sep. 5, 1995.
In the DRAM of the publication, the silicon storage electrode of the capacitor is composed of a polycrystalline silicon layer and an amorphous silicon layer. Generally, if the silicon layers are applied as the conductive layers, the silicon layers are introduced with an impurity having a high concentration in order to reduce the resistance and maintain good conduction therein. In the polycrystalline silicon layer of the publication, which is connected to diffusion regions (source or drain of transistors) formed in a semiconductor substrate, a conductive impurity having a deep concentration is introduced therein.
In heat treatment processes after forming the storage electrode including the silicon layer which is introduced with the deep impurity, the impurity in the silicon layer is frequently diffused in the semiconductor substrate. The diffused impurity influences an impurity concentration of the diffusion region (source or drain) formed below the storage electrode. Also, the diffused impurity brings an unexpected extension of the diffusion region during the heat treatment after forming the storage electrode.
Therefore, the characteristics of the transistors, typically a threshold voltage of the transistor, is changed to unexpected results.
If an excess of the impurity is introduced into the silicon layer, the impurity can easily diffuse into the semiconductor substrate. As above, the characteristics of the transistors are then influenced.
The smaller the size of the DRAM, the more significant is the leakage current that occurs under a field oxidation layer. Such diffusing of the impurity accelerates the leakage current. Therefore, the date-retention-time may be shorten to less than a predetermined desired date-retention-time.
An object of the present invention is to provide a semiconductor device which is capable of reducing adverse influences to characteristics of the transistor and securing a predetermined data-retention-time.
Another object is to provide a method of manufacturing such semiconductor device without the addition of many process steps.
To achieve the objects, in a semiconductor device having a silicon, the silicon layer includes a lower silicon layer and an upper silicon layer which is formed on the lower layer, wherein a concentration of impurities in the upper silicon layer is higher than that of the lower silicon layer.
According to the present invention, a semiconductor device is realized which is capable of reducing changes in characteristics of the device.

Semiconductor device and method in which contact hole is filled with silicon having low impurity concentration


The present invention provides novel anionic polymerization amine initiators having a tertiary amine group pendant to the polymer chain and processes for making the same. The initiators can be useful in the preparation of tertiary amine containing polymers, including linear, homotelechelic, heterotelechelic and radial polymers.

Monofunctional anionic initiators possessing amine functionalities are useful in preparing amino-terminated styrene-butadiene rubbers (SBR). See, for example, European Patent Application 593049A1 and U.S. Pat. No. 5,496,940 to Bridgestone Corporation. These elastomers have been shown to possess increased rebound, decreased rolling resistance, and lower heat build-up (reduced hysteresis). They are useful in forming improved, energy efficient tires, power belts, and mechanical goods.
Typically, the tertiary amino functionality is connected to the alkali metal via a connecting group. Exemplary tertiary amino initiators are illustrated, for example, in FIG. 1 below. Thus, the tertiary amine functionality of the resultant polymer is attached directly on the polymer backbone. ##STR1##
wherein:
M is an alkali metal, preferably lithium; PA1 R.sup.1 and R.sup.2 are alkyl, cycloalkyl or aralkyl having from 1 to 12 carbon atoms; PA1 R.sup.3 is a linear-, branched-, or cyclo-alkylene having from 2 to 20 carbon; and PA1 R.sup.4 is a divalent alkylene, oxy- or amino-alkylene, or substituted alkylene having 6 to 20 carbon atoms. See U.S. Pat. Nos. 5,332,810 and 5,496,940. PA1 Z is a halogen atom; PA1 R.sup.1 is selected from the group consisting of organic groups containing from 1 to about 12 carbon atoms and a bridging bond; PA1 each R.sup.2 is independently selected from the group consisting of hydrogen, organic groups containing from 1 to about 12 carbon atoms and a bridging bond; PA1 each R.sup.3 is independently selected from the group consisting of hydrogen, organic groups containing from 1 to about 12 carbon atoms; PA1 a is an integer from 4 to about 16; and PA1 b is an integer from 0 to about 12. These materials, however, were not very efficient electrophiles, as relatively low incorporation of tertiary amine functionality was obtained (11-73%). PA1 M is an alkali metal; PA1 R.sup.1 is chiral or achiral and is selected from the group consisting of saturated and unsaturated, linear and branched, optionally silyl-, amino-, or oxy-substituted, C3-C16 alkyl; and saturated and unsaturated, linear and branched, C3 -C16 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; PA1 R.sup.2 is chiral or achiral and is selected from the group consisting of saturated and unsaturated, linear and branched, optionally silyl-, amino-, or oxy-substituted, C1-C16 alkyl; saturated and unsaturated, optionally silyl-, amino-, or oxy-substituted, C3-C16 cycloalkyl; saturated and unsaturated, linear and branched, substituted C1-C16 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; and saturated and unsaturated substituted C3-C16 cycloalkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; PA1 R.sup.3 is a hydrocarbon connecting group or tether selected from the group consisting of saturated and unsaturated, linear and branched C1-C25 alkyl; saturated and unsaturated C3-C25 cycloalkyl; saturated and unsaturated substituted C1-C25 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; and saturated and unsaturated substituted C3-C25 cycloalkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl, with the proviso that the nitrogen atom and the alkali metal are separated by three or more carbon atoms; PA1 Q is a saturated or unsaturated hydrocarbyl group derived by incorporation of one or more conjugated diene hydrocarbons, one or more alkenylsubstituted aromatic compounds, or mixtures of one or more dienes with one or more alkenylsubstituted aromatic compounds into the M--R.sup.3 linkage; and PA1 n is an integer from 1 to 5. PA1 M is an alkali metal; PA1 R.sup.1 is chiral or achiral and is selected from the group consisting of saturated and unsaturated, linear and branched, optionally silyl-, amino-, or oxy-substituted, C3-C16 alkyl; and saturated and unsaturated, linear and branched, C3-C16 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; PA1 R.sup.2 is chiral or achiral and is selected from the group consisting of saturated and unsaturated, linear and branched, optionally silyl-, amino-, or oxy-substituted, C1-C16 alkyl; saturated and unsaturated, optionally silyl-, amino-, or oxy-substituted, C3-C16 cycloalkyl; saturated and unsaturated, linear and branched, substituted C1-C16 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; and saturated and unsaturated substituted C3-C16 cycloalkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; and PA1 R.sup.3 is a hydrocarbon connecting group or tether selected from the group consisting of saturated and unsaturated, linear and branched C1-C25 alkyl; saturated and unsaturated C3-C25 cycloalkyl; saturated and unsaturated substituted C1-C25 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; and saturated and unsaturated substituted C3-C25 cycloalkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl, with the proviso that the nitrogen atom and the alkali metal are separated by three or more carbon atoms. PA1 X is halogen selected from the group consisting of chlorine, bromine and iodine; and R.sup.1, R.sup.2, and R.sup.3 are as defined above. These halides are commercially available or can be prepared using techniques known in the art. PA1 M is an alkali metal; PA1 R.sup.1 is chiral or achiral and is selected from the group consisting of saturated and unsaturated, linear and branched, optionally silyl-, amino-, or oxy-substituted, C3-C16 alkyl; and saturated and unsaturated, linear and branched, C3-C16 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; PA1 R.sup.2 is chiral or achiral and is selected from the group consisting of saturated and unsaturated, linear and branched, optionally silyl-, amino-, or oxy-substituted, C1-C16 alkyl; saturated and unsaturated, optionally silyl-, amino-, or oxy-substituted, C3-C16 cycloalkyl; saturated and unsaturated, linear and branched, substituted C1-C16 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; and saturated and unsaturated substituted C3-C16 cycloalkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; PA1 R.sup.3 is a hydrocarbon connecting group or tether selected from the group consisting of saturated and unsaturated, linear and branched C1-C25 alkyl; saturated and unsaturated C3-C25 cycloalkyl; saturated and unsaturated substituted C1-C25 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; and saturated and unsaturated substituted C3-C25 cycloalkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl, with the proviso that the nitrogen atom and the alkali metal are separated by three or more carbon atoms; PA1 Q is a saturated or unsaturated hydrocarbyl group derived by incorporation of one or more conjugated diene hydrocarbons, one or more alkenylsubstituted aromatic compounds, or mixtures of one or more dienes with one or more alkenylsubstituted aromatic compounds into the M--R.sup.3 linkage; and PA1 n is an integer from 1 to 5. PA1 M is an alkali metal; PA1 R.sup.1 is chiral or achiral and is selected from the group consisting of saturated and unsaturated, linear and branched, optionally silyl-, amino-, or oxy-substituted, C3-C16 alkyl; and saturated and unsaturated, linear and branched, C3-C16 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; PA1 R.sup.2 is chiral or achiral and is selected from the group consisting of saturated and unsaturated, linear and branched, optionally silyl-, amino-, or oxy-substituted, C1-C16 alkyl; saturated and unsaturated, optionally silyl-, amino-, or oxy-substituted, C3-C16 cycloalkyl; saturated and unsaturated, linear and branched, substituted C1-C16 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; and saturated and unsaturated substituted C3-C16 cycloalkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; PA1 R.sup.3 is a hydrocarbon connecting group or tether selected from the group consisting of saturated and unsaturated, linear and branched C1-C25 alkyl; saturated and unsaturated C3-C25 cycloalkyl; saturated and unsaturated substituted C1-C25 alkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl; and saturated and unsaturated substituted C3-C25 cycloalkyl containing saturated or unsaturated lower alkyl, aryl, or substituted aryl, with the proviso that the nitrogen atom and the alkali metal are separated by three or more carbon atoms; PA1 Q is a saturated or unsaturated hydrocarbyl group derived by incorporation of one or more conjugated diene hydrocarbons, one or more alkenylsubstituted aromatic compounds, or mixtures of one or more dienes with one or more alkenylsubstituted aromatic compounds into the M--R.sup.3 linkage; and PA1 n is an integer from 1 to 5, PA1 R.sup.1, R.sup.2, R.sup.3, Q and n are as defined above; PA1 n is an integer from 0 to 5; PA1 P is a saturated or unsaturated hydrocarbyl group derived by incorporation of one or more compounds selected from the group consisting of conjugated dienes, alkenylsubstituted aromatic hydrocarbons and mixtures thereof; PA1 z is an integer from 2 to 10,000; and PA1 FG is hydrogen or a protected or unprotected functional group. PA1 FIG. 7 EQU X--Z--T--(A--R.sup.4 R.sup.5 R.sup.6).sub.m PA1 X is halogen selected from the group consisting of chloride, bromide and iodide; PA1 Z is a branched or straight chain hydrocarbon connecting group which contains 1-25 carbon atoms, optionally substituted with aryl or substituted aryl; PA1 T is selected from the group consisting of oxygen, sulfur, and nitrogen and mixtures thereof, PA1 A is an element selected from Group IVa of the Periodic Table of the Elements; PA1 R.sup.4, R.sup.5, and R.sup.6 are each independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, and substituted cycloalkyl, or R.sup.6 is optionally a --(CR.sup.7 R.sup.8).sub.1 -- group linking two A when m is 2, wherein R.sup.7 and R.sup.8 are each independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, and substituted cycloalkyl and 1 is an integer from 1 to 7; and PA1 m is 1 when T is oxygen or sulfur, and 2 when T is nitrogen. Thus the skilled artisan will appreciate that R.sup.6 as used herein includes the group ##STR9## PA1 R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, Q, Z, T, A, n and m have the meanings ascribed above (i.e., FG is --Z--T--(AR.sup.4 R.sup.5 R.sup.6).sub.m). PA1 R.sup.1, R.sup.2, R.sup.3, Q, P, Z, T, m, n and z have the meanings ascribed above. PA1 R.sup.1, R.sup.2, R.sup.3, Q, P, Z, T, n and z have the meanings ascribed above; and PA1 X is selected from the group consisting of polymer segments derived by incorporation of at least one comonomer reacted with T. PA1 R.sup.1, R.sup.2, R.sup.3, Q, P, n, and z have the meanings ascribed above; PA1 L is a residue of a multifunctional linking agent, such as divinylbenzene; and PA1 v is from 3 to 30. As the skilled artisan will appreciate, each R.sup.1, R.sup.2, R.sup.3, Q, P, n, and z can differ if different living polymers are prepared and coupled.
Recently, a method of incorporating tertiary amine functionality was described in U.S. Pat. No. 5,736,617, to Bridgestone Corporation. This patent is directed to use of an electrophile, described generically in FIG. 2, to quench a living polymer anion. ##STR2##
wherein:

Anionic polymerization initiators containing tertiary amine functionality, their chain extended analogues, and processes for using the same


This invention relates to a low viscosity hydroxylated liquid polymer having polymerized therein a mercaptan compound containing hydroxyl and/or carboxyl group(s) in an amount sufficient to reduce viscosity and provide low peel property on the order of 10 to 25 ounces without significantly lowering the adhesive properties thereof, to a removable, low peel adhesive which is a reaction product of the liquid polymer and an isocyanate prepolymer, and to a substrate having deposited thereon said adhesive. The removable adhesive produces a clean 180.degree. peel while maintaining good tack and shear and due to its low viscosity, it can be processed at 100% solids, i.e., without any solvent.

The low-peel pressure sensitive adhesives available in commerce today have a high reject rate. They are highly compounded rubber compositions which contain large amounts of solvent, ranging up to about 60%, which must be removed before final curing of the adhesive takes place. Hot melt adhesives are also available, however, they have the disadvantage of a narrow utility range, i.e., the physical parameters must be adjusted and closely monitored for the hot melts to be in a useable condition.
To overcome these and other disadvantages of the above-mentioned adhesives, polyurethane-based adhesives have been proposed which are prepared by reacting a hydroxyl-containing liquid polymer with a prepolymer of an isocyanate-terminated polyester or polyether. Since the current coating apparatus can apply adhesives having viscosity of up to about 20,000 cps, efforts have been made to reduce viscosity of the polyurethane-based adhesives.

Hydroxyl-containing liquid polymers and adhesives made therefrom


Search queries to a search engine are collected over a period of time and used as a source of terms for selectively adding to documents. The terms may be added as meta-tags for enhancing information retrieval. Also, candidate terms may be submitted to the search engine and the most relevant documents retrieved. These documents, or portions thereof, are reviewed to determine if the content is substantially related to the term. If it is, the term is added to the document as a meta-tag and the search engine index is updated to reflect the addition. Employing this invention, search engine results will adapt to changes in usage of search terms.

1. Field of the Invention
The invention relates to information retrieval systems and particularly to an adaptive meta-tagging of documents in information retrieval systems located on network servers such as found in the World Wide Web.
2. Description of Related Art
Meta-information is information about information. Some documents or files contain sections which contain meta-information related to the contents of that document or file. An example of meta-information is a keyword list. A meta-tag is an entry in a meta-information section of a document or file.
Web search services like InfoSeek and AltaVista are better at finding the correct webpages if the pages are encoded with meta-tags specifying keywords that users want to use to find the pages in question. Unfortunately, page authors are rarely capable of predicting all the search terms users want to use in searching for the information. For example, the page for a product known as "Workshop for C" would not be found by a user entering the search phrase "C compiler" unless the page author has remembered to add the term "compiler" as a keyword in a meta-tag for the page. It is empirically true that page authors often forget to do so. The need for help in meta-tagging is particularly acute due to the verbal disagreement phenomenon which is that different people often use different terms to describe the same thing. Thus, even if the page author remembers to enter meta-tagged keywords, the author may still leave out a search term used by some users because the author simply didn't think of this term.
Some search engines attempt to compensate for poor keyword tagging by the use of synonym searches. For example, the Excite search engine has a so-called concept search that is claimed to be able to find pages even if the user's query term does not appear on the page. This method has the obvious weakness that it only helps those users who use a search engine that implement synonym searches. Furthermore, the general Internet search engines have to rely on general synonym dictionaries that are not optimized for the domain of any specific website.
The Problems
Most information retrieval systems use indexing which is static, that is, once a document is indexed, its indexing doesn't change. Since language changes, it would be desirable to permit indexing to evolve in the same way.
It would be desirable to enhance the relevance of documents or files retrieved in response to search queries.


A device and method for enhancing rapid confirmatory immunological testing (“RCIT”) in chromatography strip-type rapid IVD devices useful in, for example, clinical, point-of-care, laboratory or over-the-counter settings. The device drives a flow fluid, primarily under the force of gravity alone, through a first chamber having a porous dam structure to enhance and substantially complete the first affinity binding reaction between a source of mobilizable labeled binding members and an analyte in the fluid. Flow through the dam causes a delay, mixing and trapping of the typically chemically disuniform initial fluid front so that fluid exiting the dam exhibits a more uniformly high degree of first affinity binding and decreased non-affinity binding. Afterward, and without further human interaction, the fluid then flows under the combined, turbulence creating forces of gravity, siphoning, and capillarity, through a second chamber containing a chromatographic strip which captures the labeled analytes in a second affinity binding reaction. By separating the two affinity binding reactions, competition for analytes during each reaction is reduced, and thus accuracy improved.

Over past decades, the prior art has offered several types of rapid diagnostic testing techniques which use a body fluid such as whole blood, serum, plasma, urine, spinal fluid, amniotic fluid, mucous, saliva, and the like for detecting the presence of infection or other conditions such as cancer, pregnancy, abused drugs and cardiovascular disorders such as acute myocardial infarction (AMI). Such tests are often referred to collectively as rapid In Vitro Diagnostic ("IVD") device tests.
Unfortunately, prior rapid IVD test devices are typically useful only for preliminary screening purposes, not as a confirmatory test. Although they can be fast, inexpensive, and simple-to-use, depending on the type of condition being detected, these tests provide a typical accuracy of between 85% and 99%, falling short of the 99.9% or above accuracy generally considered to be necessary for a confirmatory test. To this day, for example, the Western Blot Analytical Assay is the only one reliably used for the confirmatory detection of HIV infection in a clinical laboratory setting worldwide. Due to its multi-step manipulation and verification phases, completion of this type of test can take days, if not weeks. Such a delay can unfortunately lead to further propagation of infectious pathogens such as HIV. Other serious results, such as the metastasis of cancers, can occur while waiting for the results of slower confirmatory tests. There is virtually no generally accepted practical or economical confirmatory rapid diagnostic testing technique for use in a point-of-care setting to rapidly detect serious diseases such as HIV infection and AMI, available in the market place today.
The reasons for the insufficient accuracy in many rapid IVD test devices are primarily due to their current lack of overall higher sensitivity and specificity. Different samples may contain chemicals or particles which inhibit the fluid flow or otherwise interfere with one or both of the affinity binding reactions. Prior devices have attempted to enhance sensitivity or specificity by pretreating various parts of the device with reaction or flow enhancing reagents, pH conditioning chemicals, or even non-specific adhesive blocking molecules which will "block-out" non-analyte molecules which might cause non-specific adhesion, or otherwise compete with the analyte in question for specific binding members, especially on the reaction membrane. These attempts have met with limited success in some types of testing, but do not provide the desired accuracy in many others. Also, pretreatment with two or more of the above pretreatments exacerbates the difficulties in obtaining uniform manufacturing due to potential incompatibilities between the pretreatment chemicals. For example, the pH conditioner might disrupt the effectiveness of the non-specific blocking member molecules. Or, the manufacturing step of pretreating with the second pretreatment chemical can dislodge some of the first pretreatment chemical.
Further, lot-to-lot variation in the manufacture of many IVD test devices can often lead to ambiguous results, such as false negatives as well as weak false positives, so-called "ghost lines" or "phantom lines". False negatives typically occur when non-specific molecules interfere with the first and/or second affinity binding actions. It has been found that non-analyte molecules can clump together in fluid samples that are not well mixed so that they temporarily prevent access between analytes and binding members. Even temporary interference can prevent an adequate number of labeled analyte complexes and/or ultimately immuno-sandwich complexes from forming. In this way, if a non-analyte molecule or clump of molecules blocks access between analytes and binding members for only a few seconds, it may be enough to induce a false negative result. Further, clumps of non-analyte molecules can carry an overabundance of the labeled mobilizable binding members to the second affinity binding site to generate a false positive.
Chemically non-uniform flows can result in flows having non-uniform first affinity binding by the time they reach the reaction membrane leading to inaccuracies. Such non-uniform flows can be caused by a number of factors. First, some portions of the fluid may flow faster than others from time to time. In those tests having deposits of dried reagent, faster flows tend to reach the dried reagent first. These flows, particularly along the initial fluid front, tend to exhibit a greater degree of first affinity binding per unit fluid or at least uptake of mobilizable labeled binding members, and can potentially carry a greater concentration of clumps of non-analyte molecules which can carry away labeled mobilized binding members. Further, the deposit of dried reagent itself can exhibit portions of higher concentration than others resulting in similar chemical nonuniformity in the flow. Other flows having a lower than average concentration of analyte molecules, and/or having a greater concentration of non-clumped, non-analyte molecules which merely inhibit analyte binding but do not carry away mobilizable labeled binding members, exhibit less apparent first affinity binding. These flow and concentration dis-uniformities are responsible for many of the unsatisfactory results discussed above.
Therefore, there is a need to improve the accuracy of rapid IVD test devices so that Rapid Confirmatory Immunological Testing ("RCIT") becomes a reality.

Interrupted, gravity-promoted, diffused flow chromatography strip testing device and method