A dental mask which has two separate chambers, one for inhalation and the other for exhalation. The two separate chambers being separated by an elasticized strip across the philtrum area. The mask is designed to be disposable, yet also have the ability to accept, for increased protection, filter insertable pads which can be placed in the inner surface of the mask. An embodiment of the mask would allow the main frame to be reusable, by having means for snapping a disposable filter onto the frame.

1. Field of the Invention
The present invention relates generally to a dental mask that is designed to be worn by members of a dental staff, and more specifically to a dental mask having dual chambers, one for inhaling and the other for exhaling.
2. Description of the Prior Art
The environment in a dental office can be detrimental to the health of both the patient and the dental staff. In addition to harmful aerosols, which studies have shown may contain up to 100,000 bacteria per cubic foot of air within three feet of the patient, the dental office may regularly contain nitrous gases, disinfectant fumes, mercury vapors, sterilization fumes, tooth dusts, fillings dust, sulfates, polyether fumes, viruses, saliva droplets, etc. The aerosols generated by air polishers are particularly harmful. High speed cutting instruments (200,000 to 300,000 rpm) generate considerable heat which can cause injury to the tooth pulp. To prevent this, water spray is employed as a coolant and a lubricant. As a result, there are microbial aerosols which are generated from the patient""s mouth during dental operations which are comparable in bacterial concentrations to those produced during coughing and sneezing.
Transmission of infection requires a series of factors: a source of reservoir for the pathogen, a pathogen of sufficient infectivity and number, a mode of escape from the host, and a portal of entry. Infection-control techniques seek to eliminate one or more links in the chain of infection. Barrier products such as masks are viewed as a means of protecting both patients and dental staff from pathogens in potentially infectious sprays, splash, and spatter. Masks must be worn when risk of spray or splash of fluids can be anticipated. The FDA recommends that surgical masks have a 95 percent or greater bacterial filtration efficiency. Masks of glass or synthetic fiber demonstrate great filtering efficiency. However, almost all the particles that can penetrate an efficient filtration mask are so small in diameter that they will be hazardous if they penetrate the alveoli of the human lungs. It is important to consider that bacterial aerosols do remain airborne for many hours after certain dental procedures, unless they are removed by an efficient ventilation system.
The prior art is well documented with masks that attempt to solve the above problems. In addition to filtration, masks seek to solve the problems such as fogging of eye glasses. Some short comings in prior art masks are masks that do not adapt very well to different sizes and shapes of faces, especially along the ridge of the nose or chin. Many masks do not provide any measure near the 95 percent FDA requirement. The fogging of glasses is due to the carbon dioxide along with warm moisture that accompanies the breath in exhalation. Lack of proper venting of the mask may cause members of the dental staff to breath in his/her own exhaled carbon dioxide, thereby diminishing the percentage of oxygen with each breath. This lack of oxygen can cause symptoms of hypoxia; that is the state in which there is inadequate oxygen to satisfactory meet the needs of tissues. The effects of long term state of hypoxia can be seen in drowsiness, inattentiveness, apathy, delayed reaction time, severe fatigue and reduced work capacity.
For an average person the intake of air with each inhaled breath is approximately 500 ml, of which about 150 ml is expired before it ever reaches the alveoli. This 150 ml of air is considered useless from the point of view of oxygenating the blood and the respiratory passageways are thereby called dead space. Thus for each breath only about 350 ml of air are actually utilized. Since the average person needs about 4200 ml of new air per minute, this will require about 12 breaths per minute. In a dental procedure, if the mask does not properly ventilate the exhaled breath, then the dentist will breathe in a percentage of his own carbon dioxide with each breath, thereby requiring far more respirations per minute to satisfy his/her oxygen requirements to thereby prevent a state of transient hypoxia.
There are basically two types of masks used in dental procedures. One is a semirigid cup-shaped mask that fits over the nose and mouth, usually with some form of a malleable soft metal to pinch over the ridge of the nose to prevent fogging. The other is a softer mask which is predominantly made of pleated layers of filter material. The main advantage of the semirigid mask is that it will keep the inner surface away from the wearer""s face. The biggest disadvantage is that both fresh air and exhale breath can mingle together in the chamber. The main advantage of the softer pleated mask is in comfort to the wearer. The problem is that, when the wearer inhales, these masks have a tendency to be drawn very close to the face, thereby creating a somewhat claustrophobic feeling, as well as the problem created when a very strong inhalation adheres a large amount of particles at the mouth or nose sites.
U.S. Pat. No. 5,307,796 issued to Kronzer et al. on May 3, 1994, discloses a face mask of the semirigid type that is very commonly found in dental offices. It is generally the least expensive and has only one chamber.
U.S. Pat. No. 4,951,662 issued to Townsend, Jr. on Aug. 28, 1990, teaches the use of a mask that seeks to eliminate fogging by having a housing adjacent to the mask which has a volume considerably larger than the mask volume, thereby permitting the breath to be substantially removed during each breathing cycle. Townsend, Jr. shows a loop encircling the wearer""s neck and suggests the use of a circulating fan to draw in fresh air.
U.S. Pat. No. 5,699,792 issued to Reese et al. on Dec. 23, 1997, discloses a face mask with enhanced facial sealing. The mask to Reese is typical of the softer pleated masks which are available and address the need for improved facial sealing to protect against bacteria, viruses, particles, blood droplets, contaminants etc.
U.S. Pat. No. 4,606,341 issued to Hubbard et al. addresses the importance of keeping the mask from collapsing against the wearer""s face, but this patent falls short of suggesting dual chambers.
U.S. Pat. No. 5,406,944 issued to Gazzara on Apr. 18, 1995, teaches the use of an adjustable face protector which provides increased prevention from contaminated fluids. The present invention addresses the use of shields as well as filtration capturing and reflective panels.
U.S. Pat. No. 5,584,078 issued to Saboory on Dec. 17, 1996, suggests the use of a detachable/disposable face shield that one can clip to a surgical mask. This patent addresses the need for a shield, mainly for the eyes, in which can be used according to the needs of the wearer.
None of the above inventions and Patents, taken either singly or in combination, is given to describe the instant invention as claimed.
Accordingly, the above problems and difficulties are obviated by the present invention which provides for a primary disposable face mask, as well as a reusable frame to be used by medical personnel, especially those in the dental profession.
More particularly, the present invention is comprised of a face mask having dual chambers. An upper chamber for inhalation of fresh air and a lower chamber for exhalation of carbon dioxide ladened breath. The lower chamber having vent flap openings on the cheek sides for the removal of spent air. Embodiments of the present invention may have tubing attached to the vent openings for releasing of the exhaled breath away from the work site. In some embodiments the tubing can be attached to an exhaust suction lines or filtration systems. The dual chambers are created by mask design and by having a band of soft elastic material across the philtrum (area between naris and upper lip) which effectively seals the two chambers from each other. By inhaling through the upper chamber, the incoming air to the lungs will not be contaminated or mixed with exhaled carbon dioxide and other unwanted substances. In lieu of the vent flaps of the preferred embodiment, some embodiments may utilize vent openings being attachable to tubing that removes the exhaled air away from the work site and possible to a filtration system, the air supply at the work site will thereby be effectively improved in quality. The lower chamber will be basically used for exhalation of carbon dioxide, which can also be aided by connecting the tubing to an evacuation device such as a suction line or fan.
The mask of the present invention provides for a mask that is basically semirigid in both the upper and lower chambers. Primary reason for this design is to incorporate the benefits of the semirigid mask in which the surface of such a mask is kept away from the skin of the wearer, thereby preventing any claustrophobic feeling or difficulty in breathing. The fan type soft mask of the prior art has an inherent flaw in that when air is inhaled, the soft mask material is sucked into the mouth area along with the air. The present invention, by utilizing the semirigid construction in the upper chamber will not experience that problem.
The present invention provides for a redesign of the filtration aspect of the mask. It establishes three areas of filtration. A primary filtration area whereby the most effective filtration must be accomplished. This is primarily in the center area of the mask over the nose, nasal passages and mouth. The second filtration area is located around the primary area, which is in the cheek area of the face. The third filtration area is mostly located in the fringe areas. It is generally acknowledged that the main area of filtration must be in the center of the mask. The present invention will incorporate a rugged, high surface area, created by peaks and valleys in the surface of the mask in this primary area. Larger particles will deposit on the peaks, which may have adhesive characteristics and smaller particles, usually viruses, bacteria and gases, will be picked up in the valley area. The present invention also acknowledges that when these particles impinge upon the mask surface that it would be beneficial that they be retained there rather than reintroduced into the area again. The present invention will incorporate a mantle projection extending outwardly from the surface of the lower chamber to provide a measure of protection to the breathing zone. The mantle having an adhesive band section which, besides trapping and retaining particles, can be manufactured so as to indicate color change. This color change is a visual indicator of when the mask needs changing. It is advisable that the mask be changed frequently, and the changing color will serve as a reminder to do so.
The present invention will improve visibility by eliminating fogging to the wearer""s glasses. The mask of the present invention will encourage the wearer to take in air only in the upper chamber and to discharge the warm, moist exhaled breath in the lower chamber. Removing spent air via the lower chamber through venting flaps or tubing will by design prevent fogging of wearer""s glasses.
The present invention realizes that some procedures will require an increased level of safety for the health personnel and thereby it is acknowledged that often it is desirable to be able to place additional insertion pads directly into the chambers.
Also an embodiment of the present invention will have means for changing filtration pads without discarding the entire mask. This will involve making the frame of the basic mask reusable. The frame therefore could be manufactured of a cloth-covered sponge material molded about the perimeter. This would make it flexible and adaptable to irregularities of the face and also provide increased comfort and sealing, while also allowing for the discarding of less expensive filtration materials. The frame will utilize periphery clips the entire perimeter, while the reusable filter pads will have cooperating curved recesses for press-fitting onto the frame (in a manner that a lid snaps onto a cup). This can permit use of a higher quality material, one that is more comfortable to the skin and yet still provide a mask with disposable filtration elements.
The present invention will have means for allowing the user to snap protective shields, light deflection shields, and tinted shields. The protective shield is a first line of defense from air borne particles which fly from the work site. The shield is pitched away from the face and mask, to prevent closure, sweating and breathing difficulties. The shields can also provide a measure of protection from ultraviolet rays, especially those rays that are used in curing of composite materials, fiberoptic lights and the bright lights illuminating the field.
The present invention will have vent flaps which open and close on pressure gradients. The vent flaps are located in both chambers. The mask itself extending further to the sides of the face than prior art masks. This enables the mask to be more uniform and easier to adapt a seal therein.
The present invention will have means for attaching tubing which is positioned whereby the spent breath can be evacuated from the lower chamber. A powered device such as a suction line, fan or filtration system can be added to the distal end of the tubes for increased suction or ventilation.
An important object of the present invention is to provide a comfortable mask which will adapt to any size or shape face.
Another object of the present invention is to provide dual chambers, one mainly for inhalation and the other mainly for exhalation.
Another object of the invention is to incorporate the benefits of both semirigid mask materials with a perimeter frame comprising of comfortable, more durable materials.
An important object of the present invention is to utilize an adhesive band section that will not only entrap contaminants but which will retain them, and will indicate by color change when the mask needs to be changed.
An object of the present invention is to utilize a high surface area in the primary filtration area, whereby peaks and valleys in the outer surface will substantially increase the surface filtration area.
Another object of the present invention is to provide vent flaps and vent openings for the evacuation of the spent carbon dioxide. The vents being positioned whereby the venting will be directed posteriorly.
Still another object of present invention is to provide a mask that will have means for adapting facial protective shields, reflective shields and tinted shields.
Another object of the present invention is to provide a frame type gasket comprising of soft cloth, soft paper, or sponge like material for contact with the face, for enhanced conformation with different facial configurations and irregularities.
Another object of the present invention is extending the mask further to the sides of the face for better sealing.
Another object of the present invention is to provide a mask that can be manufactured of inexpensive components thereby providing a mask that will be economical to the user.
These and other objects will become readily apparent upon further review of the following specification and drawings.


An improved tail fin assembly and method of attachment to a tactical missile capable of high performance motion. The tail fin is formed with a widened inner fin platform portion having a centrally disposed cavity formed by a pair of oppositely disposed walls inclined toward one another. An output control shaft extending from the missile includes a pair of oppositely disposed side walls inclined in a direction similar to the side walls of the cavity. When the tail fin is mounted on the output shaft, the end portion of the output shaft extends within the cavity until the side walls are confronting each other. A pair of fastening screws are advanced into aligned openings, drawing the inclined walls into surface contact to pre-load the tail fin assembly with preset tolerances.

1. Field of the Invention
The present invention relates to an improved tail fin assembly and method of attachment as employed in a high performance tactical missile assembly
2. Description of the Related Art
High performance tactical missiles employ a plurality of tail fins to control performance of the missile during flight to the target. Known missile assemblies mount each tail fin on a fin platform which is itself attached to the missile by special screws mounted on opposite sides of platform. In order to initiate movement of the tail fins, each platform is attached to a control shaft that mates to the bottom surface of the tail fin assembly. As the control shaft is made to rotate, the attached tail fin also rotates in a pre-determined direction, thereby controlling movement of the tactical missile assembly. A primary drawback to such an attachment assembly is the need for special tools to attach the fin platform to the control shaft. Such tools must be maintained in the inventory of all stations that could possibly have a need to replace a damaged tail fin.
To assure that the tail fin can withstand the forces incurred during high performance flight, known missile assemblies such as the AMRAAM missile employ a tail fin mounted on a fin platform and formed of a complex internal honeycomb/spar design with brazed facesheets: a design that has proven expensive to manufacture. Such a design is also missile specific, preventing the same tail fin construction design from being adapted for a variety of tactical missiles.
It has also been found that maintaining the required tolerances between conventional tail fin assemblies and their missile attachment members can be difficult at best. If the fastening screws attaching the tail fins to the missile are improperly torqued, the tail fin may become misaligned, damaging the aerodynamic integrity of tail fin assembly, which may lead to failure of the missile assembly during flight.
It is clear that there exists a need in the art for an improved tail fin assembly and method of attachment to the missile frame. Such an assembly should be able to be assembled within proper tolerances without the need for any special tools. Preferably, the tail fins should be constructed from a simple, homogenous design which can be manufactured at the lowest possible costs.

Tactical missile control surface attachment


A lubrication scavenge system is disclosed herein. The lubrication scavenge system includes a sump housing substantially encircling a structure disposed for rotation about an axis. The sump housing has an inwardly-facing surface extending at least partially about the axis in a spiral path. The spiral path increases in radial distance from the axis in the direction of rotation of the structure, in a plane perpendicular to the axis. The spiral path extends 360°.

1. Field of the Invention
The invention relates to a system for scavenging lubricant from a lubricated component that supports a structure rotating at relatively high speed such as, for example, a shaft or bearing of a turbine engine.
2. Description of Related Prior Art
Structures rotating at relatively high speeds are found in many operating environments including, for example, turbine engines for aircraft and for power generation, turbochargers, superchargers, and reciprocating engines. The rotating structures in these operating environments are often supported by lubricated components such as bearings. Other components in these environments can also receive lubricant, including seal runners and gears. A stationary structure, such as a sump, is often disposed to surround the lubricated component to collect the lubricant expelled from the lubricated component.
The performance and life of the lubricant can be enhanced if the expelled lubricant is removed from the sump relatively quickly. When the expelled lubricant resides in the sump for a relatively extended period of time, the lubricant may be undesirably churned and rapidly overheated which degrades the desirable tribological properties of the lubricant. The life of the lubricated components can in turn be enhanced if the performance and life of the lubricant is enhanced.
In many conventional lubrication systems, lubricant is supplied to the lubricated components under pressure and the system then relies on gravity to drain the lubricant from the sump. The flow of lubricant away from lubricated components can be complicated in airborne applications since the attitude of the lubricated components can change and negate the effects of gravity on the flow of lubricant.


A stair walker device for aiding ambulatory persons in ascending ad descending stairs, ramps and other uneven walkable surfaces. A pair of hand-controlled levers used separately or together to adjust the front legs, by controlling the extension or retraction of a pair of front leg portions. The rear legs are adjusted for the user""s height once only by suitable adjustable fastening. The sides of the stair walker frame can be readily folded for storage or for carrying.

1. Field of the Invention
The present invention relates to a collapsible, four-legged walker aid apparatus for those persons requiring walkers to travel on either level or inclined ground, and to negotiate stairs. The stair walker has four extendable and retractable vertical legs, with each of the front two legs being made up of three concentric tubes controllable by individual hand control levers and cables, to extend or retract the front pair of legs simultaneously.
2. Description of Related Art
References
The related art of interest shows various stair walkers and mechanisms for extending and retracting walker appendages. The related art will be discussed in the order of perceived relevance to the present invention.
U.S. Pat. No. 5,649,558 issued on Jul. 22, 1997, to Reginald L. Richards describes an accommodation walker having four legs with shortening of the front pair of legs occurring by separate hand controls to manipulate an externally exposed rack and gear control through exposed cables. The front legs are lengthened only by gravity when the racks and gears are disengaged. A reversible motor may be substituted for the rack and gears mechanism. The rear legs may be shortened by spring loaded push buttons (not shown) that cooperate with extension holes. The walker is distinguishable by its reliance on separate hand controls for the front pair of extendable legs for shortening by the non-equivalent exposed cables, rack and gear controls and motor, i.e., both handles are necessary. The front legs are lengthened manually with the aid of gravity. The present invention hides the cables and spring mechanism by the use of three tubes. Additionally, there is no suggestion for folding the walker in the manner taught in the present invention.
U.S. Pat. No. 3,455,313 issued on Jul. 15, 1969, to Harold L. King describes a four-legged walker with two arcuate cross braces. Each leg has an overlapping apertured leg extension mechanism that is extendable by a spring which is released by a right and left hand grip housing two pins traveling in slots in either the pipe or the handgrip. A cable from the hand-grip retracts a semicircular spring connected pin from a hole in the overlapping leg extension. A second coil spring effects the extension of a leg until the pin enters another hole to lock the leg extension. The separate hand-grip mechanisms and the pin locking mechanism are totally different from the single hand possible locking mechanism of the present invention. Additionally, the walker has external legs as opposed to the internal legs of the present invention and is not foldable.
U.S. Pat. No. 3,176,700 issued on Apr. 6, 1966, to John H. Drury, Jr. describes a walking aid device consisting of a tubular frame with four legs, and upper arcuate front bar, a U-shaped support bar, and hand grips on the sides of the upper arcuate front bars. The two legs regarded as rear legs have contractible leg portions which telescope into the fixed legs by depressing locking buttons located at the mid-sections of the rear legs and contracting coiled springs. Each adjustable leg is locked in a shortened state by the button accessing another hole in the upper leg. The locking button is motivated by another U-shaped spring. A bolt in an upper leg travels in a slot of the contracting leg to maintain a non-twisting condition. The process of ascending and descending stairs requires the user to rotate the walker 180 degrees. The walker is distinguishable by having only two adjustable legs, a non-folding walker and the requirement for laboriously reaching down for the release button on each leg.
U.S. Pat. No. 4,411,283 issued on Oct. 25, 1983, to Frank J. Lacarelli describes an invalid walker formed from tubular aluminum having a telescoping front leg assembly which slides through a pair of guide tubes and is integrated with a cross bar adjustment member. The rear pair of legs have hand grips on an upper medial and integral front support and an additional lower support frame, wherein both supports are clamped to the front guide tubes. The front legs are adjustable in a height range of 2 feet by utilizing a manually movable locking assembly with a clip on each leg which slides into one of 24 slots in the inner surface of the front legs. The lock must be removed first before the clip can be moved along the telescoping leg. A click and drag pin is also located on an inner surface of the guide tube to indicate the movement of the telescoping legs. The rear legs have adjustable foot portions with indexing buttons and elongated feet directed inward. The walker is distinguished by individual locking of only two front legs clips which must be manipulated by hand in a two-step process. Also, the front legs lack springs to motivate either the extension or retraction of the legs.
U.S. Pat. No. 5,636,651 issued on Jun. 10, 1997, to Eli Einbinder describes an adjustably controllable walker with two U-shaped tubes with a cross bar and four legs with wheels which can be controlled by an actuator means such as a button, pressure sensor or lever. The actuator may control a stabilizer brake mechanism to engage or release a brake. Lifting the walker can release the brake. A strain gauge or lifters may be provided to respond to the lifting force. The walker is distinguishable by its reliance on wheels and brake mechanisms.
U.S. Pat. No. 2,708,473 issued on May 17, 1955, to Harry L. Gable et al. describes a walker with six legs and feet, wherein the middle legs are positioned by set screws acting through collars on upper side bracing members. Anther set of collars on lower side bracing members stabilize the middle pair of extendable legs. The walker is deemed distinguishable by its requirement for six legs and manual adjustment of each middle leg in negotiating a flight of steps.
U.S. Pat. No. 3,387,618 issued on Jun. 11, 1968, to David T. Swann describes a walker in the form of a cane or a crutch on a vertical shaft welded to a horizontal yoke member with a pair of pivotal and vertical short legs extendable from a braced upper sleeve portion. The vertical shaft has a pivotal horizontal upper leg with a cross arm which is extendable from a sleeve section. The configuration of the walker thus accommodates three steps. The walker is distinguishable by its three-step stair conforming structure.
U.S. Pat. No. 3,421,529 issued on Jan. 14, 1969, to Richard A Vestal describes another three-step stairway walker having a main frame formed from an upper horizontal U-shaped member secured at its middle front portion, and two rectangular and vertical side subframes. Each vertical side subframe has a set of L-shaped leg portions with shorter rear leg portions. The outwardly extending feet are attached vertically to the main frame by a plurality of sleeves with the uppermost sleeve having thumb screws for securing the legs by the user. The front and rear sets of feet are adjusted to conform to the steps. The walker is distinguishable by its three-step structure.
U.S. Pat. No. 4,094,331 issued on Jun. 13, 1978, to Peter Rozsa describes a walker for negotiating stairs by ascending in one position and descending by reversing the position of the walker, and walking on a level surface by inverting the walker. The walker consists of two side frames substantially in the form of a rectangle with an indented top portion having a centered rubber or plastic sleeve. A necked and coupled center portion has a leg extending on each side (front or rear) and a pair of handles extending from a region above the necked portion and directly above the extended legs. The extendable legs are apertured sleeves locked by a spring loaded pin. The walker is distinguishable by its reliance on extending only two legs manually instead of automatically.
U.S. Pat. No. 5,740,825 issued on Apr. 21, 1998, to P. J. Brunengo describes an articulated walker having a first and second side section, each having a front and rear leg, an upper cross section, and a lower cross section. The side sections are coupled by an upper horizontal cross bar and a lower horizontal cross bar. The walker adjusts for stair height by a pivotal relationship between the upper and lower cross ties and the front and rear legs. Adjustment of the legs is achieved by pulling on handles that release a pin-locked cam mechanism located on the lower cross tie of each side section. The walker is distinguishable by not having individual legs that are adjustable and not maintaining a level upper cross tie for gripping when ascending or descending stairs.
U.S. Pat. No. 5,349,977 issued on Sep. 27, 1994, to Maurice Wood describes a kit including four supplemental legs, two actuating bars, and the mechanical means to attach the apparatus to an existing walker for the accommodation of stairs or inclines. The user is able to adjust the front and back legs of one side of the walker by pulling the actuating lever and letting gravity adjust the legs to a desired height. This allows the user to navigate stairs by leaving the walker pointed straight ahead and engaging both actuator bars, or turning the walker sideways and engaging only one actuator bar. This inventions is distinguishable in that it is an attachment to an existing walker and therefore has external components, and also by the ability to control both legs on one side with the one actuator bar but not both front legs with one lever.
U.S. Pat. No. 5,603,517 issued on Feb. 18, 1997, to Shmil Lorman describes a rollable and foldable walker frame having a seat, four wheels, and four handles. The wheels can be locked automatically by braking devices. The walker frame comprises a first frame element consisting of two parallel curvilinear tubes with extendable curved handles at the upper ends, and non-extendable wheeled legs at the opposite ends which are connected by a cross bar. A second frame element which is U-shaped in front and with L-shaped sides comprises a foldable seat with non-extendable rear wheeled legs. A third frame element with two parallel inverted L-shaped tubular portions has a second set of height adjustable handles at its upper ends, and its opposite ends are connected to the pair of first frame elements. Two pairs of braking devices are connected to the rear and front legs, each of the braking devices slidably supports one of the wheel mounts over a wheel such that the application on the frame of a downward force urges the braking of the wheels. The walker is distinguishable by its unique braking devices and four wheels.
U.S. Pat. No. 4,995,412 issued on Feb. 26, 1991, to Doris Hirn et al, describes a walker with two side sections connected in the front by two horizontal cross bars. The device is able to be transformed into a cane and is also adjustable for people of varying height and width. The walker is distinguishable by needing manual adjustment for ascending or descending stairs.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
The present invention relates to a foldable four-legged walker aid apparatus for those persons requiring walkers to travel on either level ground or inclined ground, and to negotiate both the ascent and descent of stairs. The stair walker has four extendable an retractable vertical legs, with the front two legs each being made up of three concentric tubes controllable by individual hand control levers and cables, to extend or retract the front pair of legs simultaneously. Each control lever controls both front legs, affording the advantage that a user with impaired use of one upper extremity may use just one hand to control both front legs.
Accordingly, it is a principal object of the invention to provide a four-legged walker aid apparatus with a pair of adjustable front legs and a pair of adjustable rear legs.
It is another object of the invention to provide a four-legged walker aid apparatus for traveling on either level ground, inclined ground, or in negotiating stairs.
It is a further objective of the invention to provide a four-legged walker aid apparatus wherein the pair of front legs can be automatically extended and retracted by hand control, and the height of the pair of rear legs can be adjusted manually.
Still another object of the invention is to provide a four-legged walker aid apparatus which is foldable for storage or for transporting the device, such as in a car or on escalator stairs.
Yet a further object of the invention is to provide a four-legged walker aid apparatus with one size which can accommodate persons of any height by adjustment of the P-shaped rear frame elements within the bracket holding each of the P-shaped rear frame elements to the front leg frame element.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purpose described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specifications and drawings.


In the method of precisely polishing a work, torque of a sun gear and an internal gear are kept constant and a load applied to a carrier is reduced and maintained. The method comprises the steps of: changing a rotational speed of at least one of the sun gear, the internal gear, an upper polishing plate and a lower polishing plate; measuring rotation torque of a driving motor of at least one of the sun gear and the internal gear; detecting the minimum rotation torque measured in the measuring step; and adjusting the rotational speed of at least one of the sun gear, the internal gear, the upper polishing plate and the lower polishing plate so as to make the rotation torque thereof equal to the minimum rotation torque or running rotation torque, the running rotation torque being greater by a prescribed value than the minimum rotation torque.

The present invention relates to a method of polishing a work, more precisely relates to a method of polishing a work, which is capable of reducing load applied to a carrier and the work so as to precisely polish the work.
In a conventional apparatus for polishing both surfaces of a work, e.g., lapping apparatus, polishing apparatus, a work is held by a carrier, which engages with a sun gear and an internal gear and which is orbited around the sun gear. An upper polishing plate and a lower polishing plate, which are rotated in the opposite directions, respectively contact and polish both surfaces of the work. Abrading liquid (slurry) is fed while polishing the work. In a polishing apparatus, polishing pads are respectively adhered on polishing faces of upper and lower polishing plates. Note that, in the following description, the words "abrasion" and "lapping" fall into the concept of "polish".
In the conventional polishing apparatus, the upper polishing plate and the lower polishing plates are rotated in the opposite directions. Further, an orbital direction and a speed of the carrier is adjusted so as to make a frictional force between the upper polishing plate and an upper face of the carrier and a frictional force between the lower polishing plate and a lower face of the carrier equal and orient in the opposite directions. However, the carrier is orbited and rotated, so influence of the rotation cannot be ignored. Thus, relative speeds between the polishing plates and the carrier are controlled on the basis of a prescribed formula considering the rotation of the carrier so as to reduce a load applied to the carrier (see Japanese Patent Gazette No. 5-123962).
However, in the method disclosed in the Japanese gazette, the work cannot be always precisely polished, in spite of the complex formula, due to various factors. Namely, the load applied to the carrier is influenced by not only the rotational speeds of the polishing plates, an orbital speed and the rotational speed of the carrier but also conditions of the polishing plates (polishing pads), amount of feeding abrasive liquid (slurry), etc. The conventional method does not consider those factors.


A system transacting e-commerce and related data management, analysis and reporting includes a database, first and second clients, and first through fourth servers communicatively connected to an internet network. The database stores a variety of information relating to customers and has a cost reduction database portion storing cost reduction information. The first and second client have access to the on-line system. The first server maintains a commercial website. The second server supports a consultant interface on the internet network. The third server imports financial information into the database. The fourth server receives purchasing and financial information. The filter generates purchasing options and calculates a purchase price. A first program dynamically displays a cost reduction list. A second program analyzes a customer""s purchasing history for cost effectiveness and forecasts future plans for improved purchasing implementation. A default pricing mechanism selectively uses default pricing values to generate a bid.

1. Field of the Invention
The present invention relates generally to an on-line shopping support method and system using communication networks, and more particularly to a method and system for transacting e-commerce and related data management, analysis, and reporting.
2. Description of the Related Art
Buyers in need of goods and services often spend considerable time locating an appropriate vendor. Buyers use trade publications, directories, recommendations, and other means to locate vendors. If the type of vendor needed is in a foreign country, the problem compounds. Vendors advertise through various media and by direct sales methods to make known to potential buyers what they sell and how to contact them. Once a buyer identifies a few vendors, each must be contacted to obtain product or service, price and availability information. This is a time consuming process and companies typically rely on experience purchasing staff to accomplish it. In addition, when buyers must sell surplus inventory from time to time, they must advertise, cold call, sell to brokers or the like. These processes are costly and time consuming for most businesses.
The prior art describes computerized shopping systems which employ some kind of central database of goods and services offered to buyers. Information about the goods and services offered is stored centrally and must be kept current centrally. The volume of information required to be maintained and updated in a central database system restricts it to a limited type or number of goods and services or number of vendors it can offer. It is not feasible for such systems to provide access to all standard goods and services and all suppliers world wide. For such a central database to exist, the amount of information to be stored would be awesome as would be the task of keeping it current. It simply is not feasible for central database systems to satisfy the need of buyers to receive timely quotes on an enormous variety of goods and services from vendors anywhere in the world. For this reason, existing centralized database systems are created and maintained by the one or few vendors whose goods and prices are displayed. These systems necessarily restrict a buyer""s choice of vendors.
These systems are like electronic supermarkets which are owned by a single company or an association of suppliers. In such systems, a vendor provides its database of goods and/or services to a buyer who orders items from the vendor""s database. It is analogous to walking into a vendors store and selecting items from the vendors available stock. Another such system is analogous to shopping in a mall. In this case a number of (complementary) vendors combine to offer their collective inventory to the buyer through individual databases or a combined database of available goods or services. In yet another existing system, a primary, seller, such as an insurance agency, offers to provide buyers premium quotations from the insurance carriers for which the agency is an agent.
In all of the above cases, the vendors responding to the buyers request regarding a particular good or service are either the service provider or a vendor with whom the service provider is involved in another business relationship such as advertisers in a common publication or affiliated insurance carrier. These select vendors provide the product and pricing information supplied by the system to buyers. These systems have no capacity to offer an unlimited number of goods and services from any number of vendors who wish to become members of the system. This would require an unrealistically large central database containing information about products, services and vendors. Each vendor would be required to provide detailed information to the central database about its product lines and would be required to update them daily. Accordingly, existing systems are very specialized electronic buying services with a limited selection of goods, services, and vendors. In addition, buyers wishing to sell surplus inventory from time to time cannot use these systems for that purpose.
In a conventional on-line shopping system using a personal computer based communication network or the like, a service offering side (or merchandise selling side) supplies merchandise information in response to a merchandise search request.
As on-line shopping using multimedia and networks prevails, a variety of merchandise such as daily necessities is sold on-line. Users buy a variety of merchandise at a considerable frequency through on-line shopping. In conventional on-line shopping, however, the service offering side provides merchandise information in a uniform menu style, and is unable to provide services suitable for user specific needs or conditions. On the service user side, merchandise information is searched by using a uniform menu. Therefore, as daily necessities or the like are bought at a considerable frequency, it can be anticipated some merchandise may sometimes be forgotten at the time of a purchase.
Several patents are illustrative of known technology for enabling a user to acquire goods or services while operating on-line. For example, U.S. Pat. No. 4,984,155, issued on Jan. 8, 1991 to Raymond R. Geier et al., describes a system for enabling a customer to operate a data terminal for placing an order for goods or services from a supplier, the data terminal displays information about the goods or services being ordered to complete, correct or update information available from the supplier""s catalog.
U.S. Pat. No. 5,136,501, issued on Aug. 4, 1992 to David L. Silverman et al., describes a matching system for trading instruments in which bids are automatically matched against offers for given trading instruments for automatically providing matching transactions in order to complete trades for the given trading instruments, includes a host computer means comprising means for anonymously matching active bids and offers in the system by trading instrument based on a variable matching criteria, which comprises a counterpart credit limit between counterparts to a potential matching transaction.
U.S. Pat. No. 5,351,186, issued on Sep. 27, 1994 to Wayne J. Bullock et al. describes a system and method for obtaining information concerning a product or a service to a user which includes a remotely located source of computer-based information for generating and transmitting encoded data, including encoded audio data, pertaining to a plurality of products or services.
U.S. Pat. No. 5,493,490, issued on Feb. 20, 1996 to Jerome D. Johnson, describes an electronic system for creating customized product proposals stores a plurality of pictures and text segments to be used as building blocks in creating the proposal.
U.S. Pat. No. 5,664,115, issued on Sep. 2, 1997 to Richard Fraser, describes a method and apparatus for automatically matching, sellers of property with potential buyers through a communications network (preferably the Internet) in which a host system communicates with the sellers and the potential buyers over telephone or dedicated data transmission lines.
U.S. Pat. No. 5,717,989, issued on Feb. 10, 1998 to Guy Frederick Tozzoli et al., describes a system that stores criteria specified by a funder relating to trade transactions for buyers and sellers. The system compares the criteria with a proposed purchase order to determine whether the system can generate a payment guarantee on behalf of the funder for the buyer to the seller.
U.S. Pat. No. 5,758,328, issued on May 26, 1998 to Joseph Giovannoli, describes a computer system forming a computer based communications network of network members inclusive of network buyers and or network vendors for processing requests for quotation for goods and services through at least one central processing unit including operating system software for controlling the identification of network members, means for network buyers to generate request for quotation for goods and/or services, means for transmitting said request for quotation to said central processing unit, filter means for selecting appropriate network members to receive said request for quotation based on filter conditions defined by the buyer in said request for quotation and/or by the vendor and/or by the central processing unit, means for broadcasting said request for quotation to the network members selected by said filter means and means for responding to the generator of said request quotation with either a response to said, request for quotation or with a list of said selected network members. Filter conditions may define the class of vendors in terms of geographical location, quantity, language spoken, currency, special conditions of sale, and the like.
U.S. Pat. No. 5,790,426, issued on Aug. 4, 1998 to Gary B. Robinson, describes an automated collaborative filtering (ACF) system for recommending at least one item to a first user based on similarity in preference of the user as compared with other users. The ACF system stores rating data for items provided by users of the system.
U.S. Pat. No. 5,794,212, issued on Aug. 11, 1998 to Alfred F. Mistr, Jr., describes a method for providing more efficient communication between energy suppliers, energy purchasers, and transportation providers and having an administrator to assist in the transmission of energy as necessary for providing timely movement of energy as necessary for providing timely movement of energy.
U.S. Pat. No. 5,832,459, issued on Nov. 3, 1998 to Paul Scott Cameron et al., describes a computerized source searching system and method for the placement of an order for at least one offer via a terminal having a display.
U.S. Pat. No. 5,842,178, issued on Nov. 24, 1998 to Joseph Giovannoli, describes a computerized system for forming a computer based communications network of network members inclusive of network buyers and or network vendors for processing request for quotation for goods and services through at least one central processing unit including operating system software for controlling the central processing unit, storage means containing the identification of network members, means for network buyers to generate request for quotation for goods and/or services, means for transmitting said request for quotation to said central processing unit, filter means for selecting appropriate network members to receive said request for quotation based on filter conditions defined by the buyer in said request for quotation and/or by the vendor and/or by the central processing unit, means for broadcasting said request for quotation to the network members selected by said filter means and means for responding to the generator of said request for quotation with either a response to said request for quotation or with a list of said selected network members. Filter condition may define the class of vendors in terms, of geographical location, quantity, language spoken, currency, special conditions of sale, and the like.
U.S. Pat. No. 5,862,223, issued on Jan. 19, 1999 to Jay S. Walker et al. describes an expert matching method and apparatus for managing communications between an expert having particular qualifications and an end user seeking a solution to an expert request.
U.S. Pat. No. 5,873,071, issued on Feb. 16, 1999 to Robert A. Ferstenberg et al., describes software processes distributed on one or more computer systems that exchange messages in order to facilitate an intermediated exchange of financial commodities between a plurality of exchange of financial commodities between a plurality of participants.
U.S. Pat. No. 5,924,082, issued on Jul. 13, 1999 to David L. Silverman et al., describes a negotiated matching system that includes a plurality of remote terminals associated with respective potential counterparts, a communications network for permitting communication between the remote terminals, and a matching station. Each user enters trading information and ranking information into his or her remote terminal. The matching station then uses the trading and ranking information from each user to identify transactions between counterparts that are mutually acceptable based on the ranking information, thereby matching potential counterparts that are mutually acceptable based on the ranking, information, thereby matching potential counterparts to a transaction.
U.S. Pat. No. 5,924,083, issued on Jul. 13, 1999 to David L. Silverman et al., describes a distributed electronic trading system for displaying a real-time credit filtered view of at least one market in which financial instruments are traded in which the market view includes a predetermined number of orders currently available to a viewing trading entity based upon one or more credit limits entered by the viewing trading entities and/or other trading entities in the system includes a host for receiving and storing orders and credit information entered by a plurality of trading entities including the viewing trading entity, for transmitting the orders and predetermined display parameters, and for selectively transmitting the credit information; a plurality of intelligent nodes linked to the host; and a plurality of key stations respectively linked to one or more of the intelligent nodes.
Japanese Pat. No. 54-127255, issued on Mar. 10, 1979 describes an on-line network system for information on used car stock registration.
However, none of the aforementioned inventions describe a method and system for transacting e-commerce and related data management, analysis, and reporting that includes a filtering means for generating purchasing options based expert criteria, as purchasing price calculation, and filtering input data. None of the aforementioned inventions describe a method and system for transacting e-commerce and related data management, analysis, and reporting that incorporates a cost reduction program for dynamically generating a list of cost reduction options tailored for a particular type of customer. Moreover, none of the aforementioned inventions describe a method and system for transacting e-commerce and related data management, analysis, and reporting having default vendor pricing options for enabling vendors to selectively use default pricing values in their bids.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a method for transacting e-commerce and related data management, analysis, and reporting solving the aforementioned problems is desired.
The present invention is a method and system for transacting e-commerce and related data management, analysis, and reporting. A database is communicatively connected to an internet network for enabling customers to store a variety of information relating to themselves. The database has a cost reduction database portion for storing information relating to cost reduction options. At least one first client is communicatively connected to the internet network for enabling a customer to access the on-line system. At least one second client is communicatively connected to the internet network for enabling a vendor to obtain access to the same on-line system. At least one first server is communicatively connected to the internet network for maintaining a commercial website. At least one second server is communicatively connected to the internet network for supporting a consultant interface on the internet network. A third server is communicatively connected to the internet network for enabling the predefined customers to import financial information into the database. A fourth server is communicatively connected to the internet network for enabling users to transmit purchasing and financial information to said. fourth server via the internet network. A filtering means is used for generating purchasing options by filtering a customer""s information with expert criteria, calculating a purchase price, and filtering the customer""s information with vendor offerings. A first programmed means is used for dynamically displaying a list of cost reduction options tailored to an applicable class of customers. A second programmed means is used for analyzing a customer""s purchasing history for cost effectiveness and for forecasting future plans for improved purchasing implementation. A default pricing means is used for selectively using default pricing values to generate a bid.
Accordingly, it is a principal object of the invention to provide a method and system for transacting e-commerce and related data management, analysis, and reporting that has a filtering means for selecting purchasing options based on expert criteria, purchasing price calculation, and filtering input data.
It is another object of the invention to provide a method and system for transacting e-commerce and related data management, analysis, and reporting that utilizes a cost reduction program for dynamically producing a list of cost reduction options tailored for a particular type of customer.
It is a further object of the invention to provide a method and system for transacting e-commerce and related data management, analysis, and reporting that has default pricing options for vendors to facilitate bidding by vendors.
Still another object of the invention is to provide a method and system for transacting e-commerce and related data management, analysis, and reporting that includes a processing means for conducting purchasing and cost reduction analysis and forecasting.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.

Method and system for e-commerce and related data management, analysis and reporting


An apparatus for folding an airbag for a vehicle occupant restraint system comprises a base for the airbag to be folded, a cover for the airbag, and a flexible element that is arranged between the base and the cover and has first and second ends. The first end of the flexible element is held between the base and the cover. The apparatus further comprises a traction means that acts upon the second end of the flexible element, and a pressure generating means with which the airbag can be acted upon with compressed gas. The invention further relates to a method of folding an airbag and making use of such an apparatus. Still further, the invention relates to a folded airbag produced by such a method.

The invention relates to an apparatus for folding an airbag for a vehicle occupant restraint system, to a method of folding such an airbag as well as to a folded airbag.
Airbags that can be changed from a folded state into an unfolded state through the activation of a gas generator have meanwhile become a common feature of vehicle occupant restraint systems. An important requirement that such an airbag restraint system must fulfill is that the airbag has to be able to unfold completely within a very short period of time. The unfolding method is essentially determined by the manner in which the airbag was previously folded.
In the past, airbags were generally pleated in an accordion-like manner, for example, using folding blades. However, it was found that the relatively large folds created in this manner hinder the unfolding of the airbag. Nowadays, airbags are often not folded precisely, but rather simply pushed together, resulting in a chaotic folding pattern. The term xe2x80x9cchaoticxe2x80x9d means that the actual position of the various wall parts of the airbag cannot be predicted and will differ from one airbag to the next. In comparison to conventional methods that use folding blades, such a chaotic folding or pushing together method offers the advantage that it calls for less work for the folding and it results in better unfolding.
The object of the invention is to provide an apparatus as well as a method of folding an airbag in chaotic manner, with apparatus as well as method involving less effort for the folding.
This is achieved in an apparatus which comprises a base for the airbag to be folded, a cover for the airbag, and a flexible element that is arranged between the base and the cover and has first and second ends. The first end of the flexible element is held between the base and the cover. The apparatus further comprises a traction means that acts upon the second end of the flexible element, and a pressure generating means with which the airbag can be acted upon with compressed gas. The flexible element is arranged in such a way that it loops around the airbag which is disposed between the base and the cover. By pulling on the second end of the flexible element, the latter is pulled together, forming a loop that gets tighter and tighter. As a result, the airbag is pushed together from the outside towards the inside until it reaches the desired, completely folded state. In comparison to other apparatus that work with pushing elements or blades, this results in an especially simple structure, since no complicated movements are needed to fold the airbag; a simple pulling motion on the second end of the flexible element is sufficient.
Preferably, the base and the cover are arranged so as to have a defined distance from each other, the flexible element being a metal strip having a width which corresponds to this distance between the base and the cover. This forms a space that is completely enclosed by the metal strip, the base and the cover, and from which the airbag cannot escape when it is being folded. The metal strip is preferably a spring steel strip that, after being pulled together, recovers its original, expanded form once the second end is released.
According to the preferred embodiment of the invention, it is provided that the first end of the flexible element is firmly attached between the base and the cover. This facilitates both the mounting of the first end of the flexible element and the guidance of the flexible element in the area in which the flexible element is pulled out of the apparatus after it has encircled the airbag. After all, this is where the gap has to be as narrow as possible, so as to prevent the airbag from getting caught in the gap that is present between the flexible element forming the loop and the first end of the flexible element.
When the first end of the flexible element is affixed in the manner described, the entire airbag, except for the area that is immediately adjacent to the first end of the flexible element, is moved towards this first end while the airbag is being folded. For this reason, it is preferable for the base to be provided with a receptacle for a holding plate of the airbag and for the receptacle to be designed in the nature of a sliding guide. This ensures that the airbag, in spite of shifting when it is being pushed together, assumes a folded form in which its wall is arranged approximately symmetrically around the airbag""s inflation opening, which is normally located in the area of the holding plate.
According to an alternative embodiment, it can also be provided that the first end of the flexible element is disposed between the base and the cover in such a way that it can be translatorily shifted. With this configuration, the center of the airbagxe2x80x94that is to say, for example, the inflation opening that is provided with the holding platexe2x80x94remains stationary while all of the wall parts are moved symmetrically from the outside to the inside towards the inflation opening.
An adjusting cylinder, for instance, can be used to pull the flexible element out of the area between the base and the cover. Such an adjusting cylinder is a component of simple structure, with which the loop encircling the airbag can be pulled together easily, e.g. in a displacement-controlled or force-controlled manner. When the loop formed by the flexible element is pulled together in a displacement-controlled manner, the pushing procedure is only terminated once the airbag has been pushed together to a predefined circumference. When the airbag is pushed together in a force-controlled manner, the pulling together of the loop is completed as soon as the wall of the airbag offers a predefined resistance against being pushed together any further.
According to the preferred embodiment of the invention, the pressure generating means is configured as a fan. This makes it possible to pressurize the inside of the airbag in a simple manner so that the airbag unfolds between the base and the cover as well as the flexible element. In this manner, the airbag can be rendered into a partially folded state in which its height corresponds, for example, to the height of a receptacle provided to receive the airbag. In other words, the airbag is unfolded by the pressure generating means so as to have a shape in which the airbag has only a fraction of the height in comparison to the completely unfolded state.
In a preferred arrangement, the flexible element is provided with a large number of small openings and the pressure generating means is in flow connection with an outside surface of the flexible element. In this manner, an air cushion can be generated between the wall of the airbag and the flexible element. The air cushion reduces the friction between the wall of the airbag and the flexible element so that the flexible element entrains the walls not so much in the circumferential direction but rather acts upon them predominantly from the outside towards the inside.
In order to achieve the above-mentioned objective, a method of folding an airbag is also provided that comprises the following steps: first of all, the airbag is spread out on the base within an area that is encircled by the flexible element. Then the cover is placed onto the flexible element. Subsequently, the airbag is acted upon with pressure. As a result, it unfolds between the base, the cover and the flexible element. Then the flexible element is pulled together by pulling at its second end, as a result of which the airbag is pushed together. As far as the advantages of this method are concerned, reference is made to the explanations above.
An airbag that is folded together by the apparatus according to the invention and by the method according to the invention is distinguished in that its wall has a large number of chaotically arranged individual folding lines, several main folding lines being present that run in a slightly spiral shape around a center. The individual folding lines result from the essentially radial pushing together of the airbag from the outside towards the inside. The main folding lines that run in a spiral shape result from the friction between the flexible element and the walls of the airbag; the individual contact sites between the flexible element and the wall of the airbag execute a spiral-shaped motion when the loop formed around the airbag by the flexible element is pulled together.
Advantageous embodiments of the invention will be apparent from the subordinate claims.

Apparatus and method for folding an airbag as well as a folded airbag

TRW Automotive Safety Systems GmbH and Co. KG


A process for simultaneously selectively depositing a high purity nickel containing alloy (i.e. a nickel-boron alloy having a nickel content in excess of 99.5 percent) over a preformed metallurgy pattern (including the individual, electrically isolated contact pads and the seal band area thereon) on the top-side dielectric surface of a multi-layer ceramic module. The metallurgy pattern on such top-side surface of such module is appropriately catalyzed and then immersed in a bath which is essentially lead-free and which includes a source of nickel ions, a borane reducing agent, and an effective amount of an organic divalent sulfur compound, preferably thiodiglycollic acid. The contact pads and the seal band area so plated exhibit an exceptionally uniform layer of nickel-boron alloy, free of surface irregularities, which layer is characterized by low contact resistance, excellent wire bonding and eutectic diode bonding characteristics and is both crack-free at the time of its being deposited and remains crack-free under brazing conditions throughout the life of the component.

The present invention generally relates to a method of selectively chemically depositing nickel containing alloys over existing metallurgy patterns on a dielectric substrate, and to products produced thereby. More particularly, this invention is directed to the electroless plating of nickel-boron alloys over metallurgy patterns on ceramic substrates in high-circuit-density electronic components. In this regard, an important aspect of the present invention is specifically concerned with multi-layer ceramic modules used in semiconductor package assemblies and, particularly, with the simultaneous chemical deposition, by electroless plating procedures, of essentially crack-free, nickel-boron alloys of uniform thickness onto a plurality of discrete and electrically isolated contact pads as well as onto the seal areas which surround such contact pads, thereby providing such contact pads with improved solderability, brazability, and wire and diode bonding properties as well as providing the seal areas with improved hermetic sealing characteristics.
Multi-layer ceramic technology for producing substrates for integrated circuit semiconductor package assemblies is relatively well known in the art. These substrates are commonly produced by preparing a slurry of a suitable particulate ceramic, a resin binder material, a solvent for the resin binder, and a plasticizing agent. This slurry is typically applied by a doctor blade onto a base and then dried to form thin flexible sheets which are commonly termed ceramic green sheets.
The green sheets are then punched at predetermined locations to provide via holes and pin contact holes which are later filled with conductive material for electrically connecting the conductive patterns to be located at distinct horizontal levels within the monolithic structure which is to be ultimately produced. The conductive material, usually in a paste-like form which includes an electrically conductive component such as, for example, molybdenum-manganese, molybdenum, tungsten, molybdenum-manganese-silica or tungsten-manganese-silica together with a suitable binder, is then deposited by brushing, spraying or the like, usually using a silk screen, to form a desired circuit pattern which may include a ground plane, voltage plane and electrically isolated contact pads, some of which extend through the previously punched holes. The green sheet which is intended for the top surface of the multi-layer ceramic module will, in addition, also include a seal band strip or area that peripherally surrounds the contact pads and which is likewise coated with the conductive paste. The paste is then dried, a typical drying time and temperature being approximately ten minutes at 100.degree. C. If desired, resistors, inductors, capacitors and other circuit components can be screened on the green sheets.
The green sheets are then stacked one upon the other, often in stacks of 15 to 30 or more sheets, with via holes in registry where desired, and the unit then subjected to moderate temperature and pressure between platens of a press for a time period which is sufficient to laminate the sheets into a monolithic body. For example, a typical lamination cycle calls for holding the stack at 175.degree. F. and 100 psi for about five minutes and then raising the pressure to 800 psi for five minutes. This two-step operation permits any remaining volatiles to escape from between lamina and thus prevent the formation of voids. Contact or input-output pins (I/O pins), typically formed of an iron-nickel cobalt alloy can be inserted into previously metallized surfaces of the contact holes to facilitate external communication with the internal circuitry.
The resultant structure is then fired in air, at the maturing point of the ceramic module which is below the melting point of the conductive material of the conductive paste. The firing cycle can then be carried on for approximately 15 hours, the effect of which is to burn off the binder and any remaining volatile constituents, typically at the 500.degree. to 600.degree. C. temperature range, mature or vitrify the body, fire the screened contact pads as well as the seal band strip, and intimately bond them and the pin contacts to the ceramic material.
Generally, it is desirable that the multi-layer ceramic substrate be formed with the lines in the via holes conforming to very small dimensions, such microminiaturization being desirable in order that the package be compatible with integrated circuit device chips which are to be mounted thereon. The module, therefore, must be provided on the top surface with many small pads which are closely spaced to, but electrically isolated from, each other and capable of making electrical contact with correspondingly closely spaced terminal devices. In order to more efficiently use the modern integrated circuit technology, as many as possible integrated circuit devices are supported and interconnected within the same module. This arrangement keeps the distance between the interconnected devices small and thereby minimizes the time it takes for electrical signals to travel from interrelated devices. In addition, this arrangement also reduces the number of electrical connections which must be made and thereby reduces the cost of the package and increases its reliability. The desirable end result being a highly complex, multi-layer ceramic package with a substantial amount of microsized internal printed circuitry contained in a relatively large module capable of mounting a large number of integrated circuit devices.
These multi-layer ceramic modules require complex metallurgy (i.e. the further application of relatively thin metallurgy layers) on the top-side to make connections to the integrated circuit devices and provide engineering change pads, and on the bottom-side to make connection to the I/O pads or other types of connections. In the past, a multi-step electrolytic/electroless deposition procedure has been employed to separately deposit a nickel layer on these contact pads and seal band strips on the top-side surface of the module. That is, the seal area has initially been coated with a nickel deposit by conventional electrolytic techniques requiring electrical connection of the seal band strip during such electroplating operation. Thereafter, a resist was applied to the thus electrolytically plated area and the surface cleaned so as to permit electroless plating of the electrically isolated contact pads with the resist thereafter being removed.
As can be appreciated, this dual plating operation not only involves a plurality of steps which result in increased cost and complexity, but also inherently increases the likelihood of potential product imperfections in the resultant assembly, producing a higher than desired product rejection rate.
The present invention overcomes these disadvantages in the heretofore practiced dual plating procedures for these multi-layer ceramic modules as well as other plating procedures wherein like problems are experienced by providing a novel process for simultaneously selectively depositing a nickel-containing alloy layer over the preformed metallurgy pattern on the top-side dielectric substrate (i.e. the plurality of individual, electrically isolated contact pads and the seal band area).
In accordance with this invention, the electrically conductive material including both the circuit components (e.g. contact pads) and the seal band area is catalyzed by treating such surface with a suitable electroless plating initiating metal, for example, by dipping the conductive material in a palladium chloride solution which, while catalyzing the individual areas which are to be chemically deposited with the nickel alloy component, also greatly assists in maintaining electrical isolation (i.e. avoids nickel deposition) between the electrically isolated contact pads. Alternatively, the conductive material can, in specialized instances, have a suitable catalyzing material (e.g. nickel metal) blended into the paste so that it is present in the deposit when initially applied to the ceramic green sheet. The thus catalyzed surfaces are then immersed in a bath which is essentially lead-free and includes a source of nickel ions, a borane reducing agent, and an effective amount of an organic divalent sulfur compound, for example, a sulfur-containing aliphatic carboxylic acid, alcohol, or derivatives thereof, preferably thiodiglycollic acid. These baths may optionally include one or more additional stabilizers, buffers, and other conventional electroless nickel bath additives.
The contact pads and seal band strip so plated exhibit an exceptionally uniform layer of nickel-boron alloy, free of surface irregularities, which is characterized by low contact resistance and excellent wire bonding and eutectic diode bonding characteristics. Furthermore, the nickel-boron surfaces are both crack-free at the time they are deposited and remain crack-free under brazing conditions and throughout the life of the component. If desired, these nickel-boron alloy layers can also be further plated with other metals, for example, noble metals such as gold.
It is, therefore, a general object of the present invention to provide a new and improved process for selectively chemically depositing a high purity nickel-containing alloy over an existing metallurgy pattern which has been previously applied to a dielectric substrate. In this regard, a further object is to provide the improved articles produced by this process.
Another object of the present invention is to provide an improved method for electrolessly plating a nickel-boron containing alloy over a metallurgy pattern on a ceramic substrate.
Another object of the present invention is to provide an improved electroless plating process for the top-side surface of multi-layer ceramic modules used in semiconductor package assemblies and to provide such improved modules as are produced by this process.
Another object of the present invention is to provide an improved, essentially crack-free, electrolessly deposited, nickel-boron coating having a boron content of 0.5 percent or less which is characterized by exceptionally uniform thickness on preformed metallurgy patterns on dielectric substrates such as, for example, ceramic substrates.
Another object of the present invention is to provide an improved electroless plating procedure which eliminates bridging between a plurality of/electrically isolated, closely spaced, preformed electrical contact pads.
Another object of the present invention is to provide an improved electroless plating process, as well as to provide articles produced by such process, whereby ductile, low stress nickel-boron alloys are deposited on pre-existing metallurgy patterns which are present on a dielectric or ceramic substrate.
Another object of the present invention is to provide an improved chemical deposition procedure whereby nickel-boron layers of substantially uniform thickness are deposited onto a preformed metallurgical pattern, without experiencing irregularities in the surfaces of such deposited layers and without edge defects therein, which deposits are further characterized by being essentially crack-free at the time of the deposit, and remain so under brazing conditions as well as throughout the life of the component to which they are applied.
Another object of the present invention is to provide an improved single step chemical plating process and article produced by such process wherein a substantially uniform, crack-free, nickel containing alloy deposit is applied to individually electrically isolated contact pads as well as to a hermetic sealing area which surrounds such contact pads, which process and article are particularly suited to meet the exacting design requirements of solid state microelectronic components.
These and other objects of the present invention will be apparent from the following description of a preferred embodiment thereof.
In general, the chemical deposition or electroless plating aspects of the present invention are particularly suited for depositing a nickel-boron alloy onto a non-conductor or dielectric substrate surface. These procedures, however, under appropriate conditions can also be utilized in the electroless deposition of nickel alloys onto metallic substrates as well. The deposits obtained on both dielectric and metallic substrates are characterized by a high-purity coating which is hard, wear-resistant, and easily soldered or brazed. Furthermore, the electroless plating aspects of this invention also find advantageous utility in both rack and barrel plating operations.
Accordingly, while the present invention has broad application to a wide variety of plating operations, it finds particularly advantageous utility in the manufacture of multi-layer ceramic modules of the type generally described above. The following description of a preferred embodiment specifically concentrates on those aspects of these manufacturing procedures which are relevant to the present invention.
Following sintering, the top-side surface of the module is cleaned to remove any contaminants thereon, typically by a trichloroethylene vapor degreasing step or other suitable alkaline cleaning operation. That surface is then treated to remove traces of the conductive paste (for example, the molybdenum-manganese or equivalent conductive material deposit) from the ceramic surface in the areas between the individual circuit elements. While this step can be accomplished in a number of different ways apparent to those skilled in the art, one suitable procedure involves the application to such surface of a solution of potassium ferricyanide and potassium hydroxide, typically in a ratio of two parts of potassium ferricyanide for each part of potassium hydroxide. This step not only functions to remove traces of the conductive material which could provide for short circuiting between the electrical contact pads, but also serves to activate the surface of such contact pads for subsequent plating. Typically, the surface is immersed in such solution for a period of from about 30 to about 50 seconds at room temperature. The surface is then rinsed to remove all traces of the alkaline solution, usually a one minute rinse with deionized water is sufficient.
Thereafter, traces of glass from the conductive paste deposits are removed by immersion of the top-side surface in a hot caustic solution such as a solution of 100 grams per liter of potassium hydroxide at 100.degree. C. for a period of from 10 to 15 minutes. If this treatment time is not of sufficient duration, the amount of metal which is exposed may be insufficient for satisfactory plating adhesion. On the other hand, if treatment time is longer than necessary, a weakened plating bond may result. Thereafter, residual quantities of the potassium hydroxide are removed by suitable rinsing such as, for example, with deionized water.
Surface preparation is then preferably followed by dipping the top-side surface to be ultimately plated in an acid solution such as, for example, a hydrochloric acid solution having a concentration of from 10 to 50 percent by weight, preferably 10 percent by weight, for a period of from 6 to 10 seconds to remove any metal oxides. Any residual hydrochloric acid remaining is removed by rinsing, again with deionized water or other suitable washing agent.
The thus prepared metallurgy pattern defined by the conductive paste is now ready to be catalyzed, that is, to make such surface receptive to accept the reduction of nickel ions in the form of nickel-boron alloys by the boron containing reducing agent in the electroless bath of the chemical plating step and to accept such deposits as a uniform layer on these surfaces. In this regard, it will be appreciated that many suitable catalyzing agents will be apparent to those skilled in this art including, in particular, both precious and non-precious metal catalyzing agents such as are described in U.S. Pat. No. 3,011,920, entitled "Method of Electroless Deposition on a Substrate and Catalyst Solution Therefor," U.S. Pat. No. 3,767,583, entitled "Activator Solutions, Their Preparation and Use in Electroless Plating of Surfaces," U.S. Pat. No. 3,841,881, entitled "Method for Electroless Deposition of Metal Using Improved Colloidal Catalyzing Solution," U.S. Pat. No. 4,048,354, entitled "Method of Preparation and Use of Novel Electroless Plating Catalysts," and U.S. Pat. No. 4,061,588, entitled "Catalyst Composition and Method of Preparation," the disclosures of all such patents being incorporated herein by reference. In general, these patents describe various catalytic systems, including colloidal solutions which function to catalyze a surface so that it is receptive to deposition thereon of the nickel-boron alloy from the electroless plating step which is to follow. Suitable catalyst systems include those colloidal systems which include cobalt, nickel, copper, palladium and silver as well as solutions resulting from the admixture of an acid-soluble salt with a catalytic metal such as gold or platinum together with hydrochloric acid, a soluble stannous salt which is present in excess of the amount necessary to reduce the metal salt to colloidal metal, and a quantity of stannic chloride. A preferred catalyzing agent is palladium chloride which typically can be employed in an aqueous solution of from 0.01 to 0.1 percent palladium chloride which also contains one milliliter per liter of concentrated hydrochloric acid. The surface to be so catalyzed is dipped in the palladium chloride solution at room temperature for approximately 30 seconds. In order to minimize the effect of an immersion deposit, it is generally preferred that the lowest concentration of palladium that will provide an active catalytic surface be employed. An actual optimum concentration of palladium chloride will, therefore, vary in accordance with the condition of the metallization in the particular application.
One particularly advantageous benefit obtained with such a palladium chloride solution is that it becomes absorbed on the conductive paste and is reduced thereon to palladium metal, a strong catalyst, while the palladium chloride which comes into contact with the dielectric or ceramic surface and may be present after rinsing, remains as palladium chloride, a relatively weak catalyst. Accordingly, during subsequent plating there is a greater tendency for the nickel-boron alloy to be deposited onto the contact pads and seal band area and to thereby assure electrical isolation between the individual contact pads.
While a separate catalyzation step can be employed as described above, it is also possible in appropriate circumstances to render the conductive paste surface active and catalytic by the incorporation therein of a suitable catalyzing agent prior to its being deposited on the substrate. For example, the addition of from 1 to 3 or more percent nickel metal or other catalyzing agent to the conductive paste (i.e. the manganese-molybdenum, molybdenum or tungsten paste) will generally be sufficient to render the metallurgy pattern on the top-side surface of the module sufficiently catalytic so as to eliminate any need for a separate catalyzing step.
Following catalyzation, the surfaces so treated are rinsed and the surfaces to be plated are now ready for bath immersion. In this regard, it is important to note that a feature of the present invention is that the electroless plating bath be essentially lead-free. Accordingly, while it has commonly been accepted in the past that the use of lead stabilizers such as, for example, lead acetate, provided advantageous deposition-enhancement characteristics to the bath, the electroless plating baths which are utilized in accordance with an important aspect of the present invention preferably are essentially lead-free, containing no lead salts or alternatively lead levels below 2 ppm and preferably below 1 ppm. These very low level lead concentrations in combination with the relatively high levels of organic divalent sulfur stabilizer, as will be more fully described hereinafter, cooperate to provide nickel-boron deposits of exceptionally uniform thickness on the contact pads and seal band area which deposits are also free of other surface imperfections which would render such thus deposited nickel-boron layers otherwise generally unsuitable for meeting the exacting and high design requirements of solid state microelectronic components.
The lead-free or essentially lead-free electroless baths which are used in accordance with an important aspect of the present invention generally include a suitable nickel source, a borane reducing agent, an effective amount of an organic divalent sulfur compound which primarily functions as a bath stabilizer and, optionally, one or more additional stabilizers, buffers, buffering systems as well as wetting agents and other conventional bath ingredients.
The source of nickel cations for these nickel-boron baths can be any of the water soluble or semi-soluble salts of nickel which are conventionally employed for such plating and which preferably are free of any lead contaminants. Suitable metal salts which can serve as sources of the nickel cations may, for example, include nickel acetate, nickel chloride, nickel sulfamate, nickel sulfate as well as other salts of nickel and other anions which are compatible with electroless nickel systems. For example, with appropriate adjustment of the complexes, nickel glycolate as well as other nickel organic compounds can be used as the source of nickel ions in the bath. Of these metal salts, nickel sulfamate is preferred. Nickel concentrations utilized in these baths are those which are typical for electroless nickel plating baths and will generally range from about 0.001 mol per liter of bath to about 0.5 mol per liter.
The borane reducing agents utilized in these nickel-boron depositing baths include any bath soluble borane source such as the amine boranes, lower alkyl substituted amine boranes, and nitrogen-inclusive heterocyclic boranes including pyridine borane and morpholine borane. These compounds are typically characterized by their inclusion of a BH.sub.3 group. The alkyl amine boranes are preferred, with dimethylamine borane being a particularly preferred reducing agent. Generally, the reducing agent concentration used in these baths is such as to effect adequate reduction of the nickel cations within the bath under the operating conditions being employed. For example, in instances wherein a catalyzing agent is directly admixed into the conductive paste prior to application to the green sheet, high concentrations of reducing agent will be required. A typical minimum concentration for the reducing agent can be as low as about 0.002 mol per liter of bath, more usually however, higher concentrations in the order of from 0.01 to about 0.1 mol per liter will be employed with approximately 0.04 mol per liter being preferred for most operations. In instances wherein dimethylamine borane is used, bath concentrations thereof of from 1 to 5 grams per liter are generally satisfactory with a concentration of approximately 2.0 to 2.5 grams per liter being preferred.
These nickel-boron plating baths in accordance with an important aspect of the present invention include an organic divalent sulfur compound which is soluble in the bath and wherein each of the two valences of the sulfur atom are directly linked with a carbon atom as a bath stabilizer. Examples of suitable organic divalent sulfur compounds which are used in accordance with the present invention are the sulfur-containing aliphatic carboxylic acids, alcohols and their derivatives, the sulfur-containing aromatic/aliphatic carboxylic acids, the sulfur-containing acetylene compounds, the aromatic sulfides, the thiophenes and thionaphthenes, the thiazoles, and thiourea. Illustrative examples of these organic sulfur compounds are shown and described in U.S. Pat. No. 3,234,031, the disclosure of which is incorporated herein by reference. Thiodiglycollic acid is a particularly preferred stabilizing agent for these nickel-boron baths. The concentration of these sulfur-containing stabilizers will typically depend upon the particular stabilizer being employed and other bath conditions. Accordingly, effective amounts of such stabilizers can be described as those amounts which will effect the desired stability to the bath while at the same time enabling reduction of the nickel-boron deposition onto the surfaces to be plated therein at the desired rate which will provide for, and enable, the obtaining of a nickel-boron deposit of substantially uniform thickness, which is essentially free of irregularities in the surface, without edge defects therein, and which is also further characterized by being essentially crack-free. Concentrations of these sulfur-containing stabilizers will generally range from approximately 0.5 to 5 mols per liter. In instances wherein the preferred thiodiglycollic acid stabilizer is utilized, it has been found that concentrations of such stabilizer in the bath of from approximately 25 to approximately 700 ppm can be utilized. Higher concentrations of such thiodiglycollic acid tend to substantially reduce the rate of deposition of the nickel-boron and, accordingly, concentrations of approximately 50 to approximately 350 ppm of thiodiglycollic acid are preferred for most applications.
The nickel-boron baths of the present invention can employ a wide variety of complexing agents, depending upon considerations such as availability, economics, and properties desired for the particular bath. Typically, bath soluble carboxylic acids and bath soluble derivatives thereof, including hydroxy-substituted carboxylic acids, substituted carboxylic acids, and bath soluble derivatives thereof including their anhydrides, salts or esters that are likewise bath soluble can be utilized. Complexing agents which are suitable can also include ammonia and other organic complex-forming agents containing one or more of the following functional groups: primary amino groups, secondary amino groups, tertiary amino groups, imino groups, carboxy groups, and hydroxy groups. In this regard, preferred complexing agents include ethylenediamine, diethylenetriamine, triethylenetetramine, ethylenediaminetetracetic acid, citric acid, tartaric acid, lactic acid and water soluble salts thereof. Related polyamines and N-carboxymethyl derivatives thereof may also be used.
The complexing agent bath concentrations will normally be dependent upon the particular complexing agent or agents which are being used within the bath as well as operating conditions within the bath. Generally speaking, the complexing agents will be present in the nickel-boron baths of the present invention at a concentration of at least about 0.005 mol per liter, while concentrations as high as bath solubility limits and economic considerations dictate, usually no higher than about 1.5 mol per liter can be utilized, a typical concentration range for the complexing agent being between about 0.005 and about 1 mol per liter of bath, preferably being between about 0.1 and 0.7 mol per liter.
Buffers and buffering systems are typically included within the nickel-boron baths of the present invention. In this regard, buffering agents must be those which are not antagonistic to the plating system. Both acidic and alkaline buffering systems are generally operative including the common carboxylic acids such as acetic, propionic, and the like. Typically, the bath may be buffered by adding a weak acid and adjusting the pH with a base, or both a weak acid and its salt may be added in the desired amounts. Another procedure which can be followed is to add the salt of a weak acid and a strong acid. This method, however, is not preferred inasmuch as the acid anion and salt cation will be present in solution. Typically, the amount of buffering agent or the buffering system which is present in these electroless nickel baths will vary depending upon conditions. A total concentration thereof of at least approximately 0.005 mol per liter is generally suitable. The concentration of such buffering agent or system, however, will vary in accordance with the needs for maintaining pH control and usually will not exceed approximately 0.4 mol per liter.
Suitable operating conditions for the nickel-boron baths of the present invention will generally range from approximately 50.degree. to 75.degree. C., with the temperature of approximately 65.degree. C. being commonly used in both barrel and rack plating operations. However, temperatures above or below these specific temperatures can be used to obtain acceptable nickel-boron deposits on preformed metallury patterns on dielectric substrate surfaces. Correspondingly, pH ranges for these baths will generally range from approximately 4.5 to approximately 7.5 with a pH of approximately 6.5 generally being preferred for most plating operations.
The nickel-boron alloy deposits which are achieved with the practice of the present invention can be characterized as high-purity nickels alloy deposits, that is, alloy deposits wherein the nickel concentration is at least 99.5 percent by weight with the remainder of the deposit being boron and being essentially free of other metals or contaminants. In this regard, it has been found that the boron content is primarily controlled by the concentration of the organic divalent sulfur compound stabilizer which is present in the bath and that in lead-free baths using the preferred thiodiglycollic acid in the preferred concentration, nickel-boron alloys having boron contents of from 0.1 to 0.2 percent will be readily obtained.
While the thickness of the nickel-boron deposit on the contact pads and seal band area will, to a great extent, be dependent upon whether subsequent processing (for example, further plating) will be performed thereon, typical nickel-boron alloy deposits of from approximately 0.5 to 7.5 microns will be commonly employed with deposit thicknesses of from 2.5 to 5.0 microns generally being preferred.
The following example illustrates a preferred embodiment of the method of the present invention.

Process for selectively depositing a nickel-boron coating over a metallurgy pattern on a dielectric substrate