In a CDMA based wireless digital communications system, a CDMA communications station. The CDMA communications station includes a signal encoder adapted to encode signaling information into a series of signaling packets, wherein the signal encoder process the signal information into variable size signaling packets in accordance with an amount of the signaling information. A voice encoder is included in the station and is adapted to encode voice information and process the voice information into a series of voice packets, wherein the voice encoder processes the voice information into variable size voice packets in accordance with an amount of the voice information. A multiplexer is included in the station wherein the multiplexer is coupled to receive the voice packets and coupled to receive the signaling packets and for combining the voice packets and the signaling packets into a traffic frame. A transmitter is coupled to the multiplexer for transmitting the traffic frame as received from the multiplexer. The multiplexer is further adapted to include the signaling packets into the traffic frame with the voice packets such that more signaling information is included in traffic frames having smaller voice packets with respect to signaling information included in traffic frames having larger voice packets such that the size of the voice packets are not constrained by the transmission of signaling packets.

The present invention relates generally to digital information systems. More particularly, the present invention relates to code division multiple access (CDMA) based transmission and reception systems for low latency, high-quality, voice applications.
The transmission of digital information and data between systems has become an essential part of commonly used systems. With such systems, information content is transmitted and received in digital form as opposed to analog form. The transmission of voice information across long distances has long been associated with well known analog transmission techniques. These techniques include, for example, the traditional plain old telephone system (POTS) network, conventional wireless VHF/UHF two-way communications systems, and the like. The modern digital form of communication and signal processing techniques offer numerous advantages and are rapidly replacing the traditional means. In most applications, the user has no perception of the digital nature of the information being received. CDMA based digital cellular systems are among the most rapidly growing of the modern forms of digital communications.
Prior art FIG. 1 shows a CDMA digital cellular system 100. System 100 typically includes many hundreds of mobile cellular telephones (e.g., xe2x80x9ccell phonesxe2x80x9d) communicatively coupled to a base station in a geographic area. FIG. 1 depicts a single such base station 104 and a single cell phone 102. The transmission system uses an RF communications channel 106 to link the base station 104 with the cell phone 102.
In typical applications, many hundreds of cell phones share the communications link 106 to the geographical area""s base station 104. Digital signal processing techniques allow the efficient use of the limited communications channel bandwidth by the multiple cell phones. CDMA is, in part, a signal processing technique which provides for the efficient multiplexing of voice and other data into discrete time and frequency based packets of information for transmission between each of a plurality of cell phones (e.g., cell phone 102) and the shared base station 104.
Although the CDMA algorithms are very efficient, the bandwidth of the communications channel 106 is finite. As with other digital communications systems, there are times when two-way communications using system 100 will suffer some amount of signal degradation during the transmission from the originating device to the receiving device.
This degradation can have many causes. For example, bad weather conditions may reduce the effective bandwidth available for communications channel 106. As another example, system 100 may at times require the transmission of large amounts of signaling and call maintenance data in addition to the voice traffic. In both these cases, the available bandwidth for transmitting voice information may at times fall below some optimal level. This degradation often results in the loss of some voice information, some distortion in the voice signal, or some noticeable noise in the received signal (e.g., as in the case of a wireless telephone). Generally, the more significant the loss of information at the receiving device, the more objectionable performance of the communications system.
Hence, the basic cause of the degradation is the fact that, at certain times, there exists more voice information than available bandwidth for transmission of the voice information, causing system 100 to reduce (e.g., throw away) some amount of voice information to fit within the available bandwidth, and the fact that at certain times, the time required to implement the various signal processing algorithms induce an objectionable degree of latency into the bi-directional communication (e.g., conversation).
In an effort to help correct this problem, the CDMA communications industry has adopted various signal encoding/decoding techniques which counteract the effects of signal degradation and improve or ensure the integrity of the information at the receiving device, and signal processing techniques which are fast executing to reduce latency. Hence, many digital communications systems available on the market use encoding/decoding methods that are each able to accomplish reasonable communication quality under normal operating conditions. However, while these encoding/decoding methods help ensure the integrity of the received information, they also tend to add a larger than desired amount of latency to communications system as the encoding/decoding algorithms are processed. Examples include standards such as IS-95A, J-STD-008, TLA/FIA-95-B, etc., which describe the multiplexing an demultiplexing primary, secondary and signaling traffic to and from an underlying physical layer traffic channel in a CDMA system.
Thus, what is needed is a solution which tailors the encoding/decoding techniques to maximize voice quality of the CDMA communications system. What is required is a method which seamlessly functions with the dynamically adjusting parameters of the encoding/decoding algorithms utilized in CDMA communications systems. What is required is a solution capable of transmitting the required side band data without adding significant latency to the voice communications data. In addition, the required solution should not overly reduce the observed voice signal quality. The present invention provides a novel solution to the above requirements.
The present invention provides a solution which tailors the encoding/decoding techniques to maximize voice quality of the CDMA communications system. The present invention provides a method and system which seamlessly functions with the dynamically adjusting parameters of the encoding/decoding algorithms utilized in CDMA communications systems. The present invention provides a solution capable of transmitting the required signaling data without adding significant latency to the voice communications data and without overly reducing the observed voice signal quality.
In one embodiment, the present invention is implemented as a CDMA communications station in a CDMA based wireless digital communications system. The CDMA communications station includes a signal encoder adapted to encode signaling information into a series of signaling packets, wherein the signal encoder process the signal information into variable size signaling packets in accordance with an amount of the signaling information. A voice encoder is included in the station and is adapted to encode voice information and process the voice information into a series of voice packets, wherein the voice encoder processes the voice information into variable size voice packets in accordance with an amount of the voice information. A multiplexer is included in the station wherein the multiplexer is coupled to receive the voice packets and coupled to receive the signaling packets and for combining the voice packets and the signaling packets into a traffic frame. A transmitter is coupled to the multiplexer for transmitting the traffic frame as received from the multiplexer.
To avoid constraining the traffic channel bandwidth available for transmitting voice information, the multiplexer maximizes voice quality by implementing the multiplex sublayer functionality in such a way as to opportunistically wait for the voice encoder to transmit a xe2x80x9cless-than-full-ratexe2x80x9d voice packets to include signaling packets rather than force the voice encoder to a lower data rate when multiplexer has signaling data to send. The multiplexer includes the signaling packets into the traffic frame with the voice packets such that more signaling information is included in traffic frames having smaller voice packets with respect to signaling information included in traffic frames having larger voice packets such that the size of the voice packets are not constrained by the transmission of signaling packets. In so doing, the data rate of the voice encoder is not artificially constrained by the signaling requirements of the communication station.

Method and system for using low data rate vocorder packets to multiplex signaling packets into a CDMA traffic channel for high quality CDMA voice transmission


The invention comprises a combination security plate for attachment to a door edge over or in conjunction with a latch set, the security plate providing protection against incursion of a credit card or other light burglary tool directed to the latch or to destruction of the latch area of the door or door stop. The combinational aspect of the design of the invention acts to protect both sides of a door so can thus be utilized on an outwardly or inwardly opening door. The security plate of the invention may be also be attached to either a left or right opening door without modification and in combination with the use on inward and outward opening applications. In those applications where only one side of the door needs protection, the plate may be easily broken into two parts so that each part may be used, respectively, on an inward and an outward opening door. A minor change in design of the security plate allows slightly better protection of the door in the area between a door knob escutcheon plate and the edge of the door on the door stop side of the door. An auxiliary plate provides nearly the same protection to the door stop material where the latter embodiment is employed.

It is well known that it is common practice to use a credit card or a similar thin, flexible instrument to disengage a door latch in a door for the purpose of illegal entry therethrough. The instrument is placed between the door and the jamb at the position of the latch mechanism and is used to force the latch bolt back into the door (out of the striker plate) to allow opening of the door.
Guard plates for the prevention of such illegal entry are commonly sold. Many institutions fabricate such plates for use in their facilities. These prior art security plates are believed to be designed and fabricated to fit a particular door/latch set combination, depending upon whether the door opens inward (toward the area to be secured) or outward (away from the area to be secured). U.S. Pat. Nos. 3,888,530, issued to Fabrici; U.S. Pat. No. 3,764,173 issued to Griffith; U.S. Pat. No. 2,144,075, issued to Mora; U.S. Pat. No. 4,183,568, issued to Ferracane; U.S. Pat. No. 3,761,119, issued to Bennett et al.; and U.S. Pat. No. 3,405,962, issued to Sushan, are illustrative of the state of the art.
These prior art designs are intended for use on only one side of a door and are not adaptable to either outward or inward opening doors.
Attention is also brought to my previous application for patent on a Double Purpose Security Plate, filed on Mar. 2, 1984 and bearing application Ser. No. 585,924, now U.S. Pat. No. 4,583,776, issued Apr. 22, 1986.


A method of forming a low dielectric constant interlayer dielectric film on a substrate by reacting, under chemical vapor deposition conditions sufficient to deposit the film on the substrate, an organosilicon precursor comprising a silyl ether, a silyl ether oligomer, or an organosilicon compound containing one or more reactive groups, to form an interlayer dielectric film having a dielectric constant of 3.5 or less. The films formed by the above method.

The electronics industry utilizes dielectric materials as insulating layers between circuits and components of integrated circuits (IC) and associated electronic devices. Line dimensions are being reduced in order to increase the speed and storage capability of microelectronic devices (e.g. computer chips). Microchip dimensions have undergone a significant decrease in the past decade such that line widths previously about 1 micron are being decreased to 0.18 micron with forecasts for as low as 0.10-0.05 in the next 5-10 years. As the line dimensions decrease, the requirements for preventing signal crossover (crosstalk) between chip components become much more rigorous. These requirements can be summarized by the expression RC, where R is the resistance of the conductive line and C is the capacitance of the insulating dielectric interlayer. C is inversely proportional to spacing and proportional to the dielectric constant (k) of the interlayer dielectric (ILD). Thus, shrinking the spacing requires a lower k to maintain an acceptable RC.
Historically, silica (SiO2) with a dielectric constant of 4.2-4.5 has been employed as the ILD. However, at line dimensions less than 0.18 microns, silica is no longer acceptable and an ILD with a k of 2.4-3.3 and below is needed.
Two general approaches to making a low k ILD are spin-on and chemical vapor deposition (CVD). Although both methods are capable of generating a low k ILD, CVD processes have the advantage of being able to utilize existing toolsets. Another advantage to CVD is simpler integration due to the silica-like structure of CVD-produced films compared to organic polymer films produced by some spin-on processes. CVD is also thought to have better conformality and gap filling capability than the spin-on method.
The current method of choice for dissociating or activating the reactive gases in a CVD chamber is by using a RF coupled plasma in a reaction zone above the substrate, such as that described in WO9941423. In plasma enhanced chemical vapor deposition (PECVD) the temperature required for the dissociation and deposition is typically between 100 and 400xc2x0 C., which is generally lower than temperatures required for thermal CVD.
Conventional silica (SiO2) CVD dielectric films produced from SiH4 or TEOS (Si(OCH2CH3)4, tetraethylorthosilicate) and O2 have a dielectric constant k greater than 4.0. There are several ways in which industry has attempted to produce silica-based CVD films with lower dielectric constants, the most successful being the doping of the insulating film with carbon atoms, fluorine atoms, or organic groups containing carbon and fluorine. Carbon doped silica, having the general formula, SiaObCcHd, (in which the atomic % of a+b+c+d=100%; a=10-35%, b=1-66%, c=1-35%, d=0-60%) will be referred to herein as organosilicate glass or OSG. Fluorine and carbon doped silica, having the general formula, SiaObCcHdFe (wherein the atomic % of a+b+c+d+e=100% and a=10-35%, b=1-66%, c=1-35%, d=0-60%, and e=0.1-25%) will be referred to as F-OSG. The ratio and structural arrangement of carbon, silicon, oxygen, fluorine, and hydrogen atoms in the final ILD is dependent on the precursors chosen, the oxidant, and the CVD process conditions, such as RF power, gas flow, residence time, and temperature.
Doping the silica with carbon atoms or organic groups lowers the k of the resulting dielectric film for several reasons. Organic groups, such as methyl, are hydrophobic; thus, adding methyl or other organic groups to the composition can act to protect the resulting CVD deposited film from contamination with moisture. The incorporation of organic groups such as methyl or phenyl can also serve to xe2x80x9copen upxe2x80x9d the structure of the silica, possibly leading to lower density through space-filling with bulky CHx bonds. Organic groups are also useful because some functionalities can be incorporated into the OSG, and then later xe2x80x9cburned outxe2x80x9d or oxidized to produce a more porous material which will inherently have a lower k. The incorporation of voids or pores in a low dielectric constant material will result in reductions in the dielectric constant proportional to the amount of porosity. While this is beneficial, the amount of porosity incorporated into the film must be balanced with the deleterious effects that the introduction of pores will have on the mechanical properties of the film. Thus the optimum amount of porosity will be material dependant.
Doping the ILD with fluorine provides low polarizability, thus leading to lower k. Fluorine-containing organic groups such as CF3 are very hydrophobic, so their presence will also serve to protect the silica from contamination with moisture.
While fluorinated silica materials have the requisite thermal and mechanical stability to withstand very high temperatures (up to 500xc2x0 C.), the materials"" properties (e.g., low water sorption, mechanical properties) are susceptible to being compromised when large amounts of fluorine are incorporated into the material. Fluorinated organic materials, such as poly(tetrafluoroethylene) despite having very low k values down to 2.0 or less, have not shown sufficient stability to the temperatures experienced during subsequent processing steps involved in the manufacture of an integrated circuit. Organic polymers in general do not possess sufficient mechanical strength for processing under current conditions. Also, fluorocarbon polymers can have other drawbacks such as poor adhesion, potential reaction with metals at high temperature, and poor rigidity at high temperature in some cases.
One way to incorporate carbon into an ILD is by using an organosilane such as methylsilanes (CH3)xSiH4-x as a silicon source in the PECVD reaction. WO9941423 and U.S. Pat. No. 6,054,379 describe the reaction of a silicon compound containing methyl groups and Sixe2x80x94H bonds with nitrous oxide (N2O) oxidant to give an SiOC film with a carbon content of 1-50% by atomic weight and a low dielectric constant.
U.S. Pat. No. 6,159,871 disclose methylsilanes (CH3)xSiH4-x (x is 1-4) as suitable CVD organosilane precursors to OSG low k films. Materials with 10-33% carbon content, by weight, and k less than 3.6 are reported.
An article by M. J. Loboda, et al., entitled xe2x80x9cDeposition of Low-K Dielectric films using Trimethylsilane,xe2x80x9d in Electrochemical Soc. Proc., Vol. 98-6, pages 145 to 152, describes the use of trimethylsilane in a PECVD process to provide films with a k of 2.6 to 3.0.
Other patents describe the use of phenyl or vinyl containing organosilane precursors in producing dielectric films. For example, U.S. Pat. No. 5,989,998 discloses the preparation of PECVD low k films from, for example, (C6H5)xSiH4-x or (CH2xe2x95x90CH)xSiH4-x) (x is 1,2 or 3), and an oxidizing gas. WO 9938202 discloses dielectric films deposited from phenyl or methylsilanes with hydrogen peroxide as the oxidant and the addition of oxygen to aid in the association between the silicon compound and the oxidant.
WO 9941423 and EP 0935283 A2 disclose siloxanes such as H(CH3)2SiOSi(CH3)2H, (CH3)3SiOSi(CH3)3, and cyclic (xe2x80x94OSiH(CH3)xe2x80x94)4 as precursors for PECVD produced OSG films.
Silyl ethers (alkoxysilanes) have also been disclosed as precursors for dielectric films. EP 0935283 A2 discloses methoxy and ethoxysilanes, such as (CH3)2Si(OCH3)2 and (CH3)(C6H5)Si(OCH3)2. U.S. Pat. No. 6,086,952 discloses a method of forming thin polymer layers by blending reactive p-xylylene monomers with one or more comonomers having silicon-oxygen bonds and at least two pendent carbon-carbon double bonds, such as tetraallyloxysilane.
U.S. Pat. No. 6,171,945 discloses a process in which organosilanes with xe2x80x9clabilexe2x80x9d ligands, such as formyl or glyoxyl groups, are reacted with a peroxide compound at the surface of the substrate, and are subsequently removed by annealing to provide a porous ILD.
U.S. Pat. No. 6,054,206 discloses deposition of a film using an organosilane and an oxidant, followed by removal of the organic component in the film with an O2 plasma to generate a porous silica material.
F-OSG is typically prepared by CVD using organosilane precursors with methyl or phenyl Cxe2x80x94F bonds. For example, WO 9941423 discloses the use of PECVD for a number of organosilane precursors with sp3-hybridized Cxe2x80x94F bonds such as (CF3)SiH3.
JP11-111712 describes the preparation of films from the deposition of (CF3)Si(CH3)3, followed by thermal treatment with O2 to generate an insulating film with a k of 2.5 to 2.6.
U.S. Pat. No. 6,020,458 teaches that the use of sp2-hybridized Cxe2x80x94F bonds, such as those in (C6F5)SiH3, is preferable due to the stronger Cxe2x80x94F bond strength, leading to greater thermal stability of the resultant ILD films.
JP10-088352 discloses the possible use of (R1O)nSi(OR2)4-n (R1 is a fluorinated alkyl chain and R2 is an non-fluorinated alkyl chain) as a precursor for a fluorine containing silicon oxide film. U.S. Pat. No. 5,948,928 discloses the possible use of fluoroacetate substituted silanes as insulating film precursors. However, both JP 10-088352 and U.S. Pat. No. 5,948,928 are directed to the preparation of fluorosilicate glass (FSG), not F-OSG films.
Inadequacies exist in currently known CVD precursors and the corresponding ILD films. One problem is that it can be difficult to include all atoms or functionalities desired in the film in the same precursor molecule, in the desired ratio to produce a SiaObCcHd or SiaObCcHdFe film, in which the total atomic % of a+b+c+d+e=100%, and a=10-35%, b=1-66%, c=1-35%, d=0-60%, and e=0-25%. Heterogenous mixtures of precursors can be used, but this is less desirable to a single-source precursor for process reasons.
The deposited ILD films should be able to withstand temperatures up to 450xc2x0 C., since some Sixe2x80x94H, Sixe2x80x94C, Cxe2x80x94H, or Cxe2x80x94F bonds can be broken at high temperatures. Release of F ions or radicals can etch the film or other components.
The low k ILD must also have suitable mechanical strength. When new low k films are substituted for traditional SiO2, subsequent integration process steps are impacted. The deposited films need to stand up to subsequent processes including chemical mechanical planarization (CMP), cap and barrier layers, and photoresist adhesion, stripping, etching and ashing.
Studies have indicated that current OSG candidates produced from trimethylsilane (3 MS) or tetramethylsilane (4 MS) limit the dielectric constant to the range of 2.6-2.9 with modulus/hardness values in the range of 4-11/0.25-1.4 GPa (Lee et al., 198th Meeting of The Electrochemical Society, October 2000, Section H-1, Abstract No. 531.)
Precursors which are safe to handle and possess long shelf lives (greater than 1 year) are also desirable. Silane (SiH4) is a pyrophoric gas, and methyl, dimethyl, or trimethylsilane are all highly flammable gases.
Finally, the CVD organosilicon precursors need to be readily available and affordable.
Despite the foregoing developments, there have not been any examples in the prior art that successfully combine the desired mechanical and electrical properties that are paramount for integrating low k dielectric materials in integrated circuits.
The need therefore remains for precursors of low k ILD films that solve the problems associated with known precursors, such as those described above.
This invention is directed to a method of making ILD films having a k of 3.5 or less, preferably 3 or less, by chemical vapor deposition (CVD), such as plasma enhanced CVD (PECVD) or thermal CVD, using specific organosilicon precursors. This invention is also directed to the films produced therefrom, and to methods of using the films.
The low k ILD films can be deposited as either OSG (SiaObCcHd) or F-OSG (SiaObCcHdFe) films (wherein the atomic % of a+b+c+d+e=100% and a=10-35%, b=1-66%, c=1-35%, d=0-60%, and e=0-25%). An oxidant such as N2O, O2, O3, or H2O2 may be used in the CVD reactor, but may not be required in all cases since many of the precursors already incorporate Sixe2x80x94O bonds. Novel porous ILD films may also be produced using these specific organosilicon precursors.
The specific organosilicon precursors of this invention are silyl ethers, silyl ether oligomers, and organosilicon compounds containing reactive groups.
The silyl ethers of this invention can have a structure as shown in structures I-VII, below, where x is an integer of 1 to 3, y is 1 or 2, and z is an integer of 2 to 6.
R1 can be one or more of H, fluorine, a branched or straight chain C1 to C6 alkyl, a C3 to C8 substituted or unsubstituted cycloalkyl, a C6 to C12 substituted or unsubstituted aromatic, a partially or fully fluorinated C1 to C6 alkyl, a partially or fully fluorinated C3 to C8 cycloalkyl, or a partially or fully fluorinated C6 to C12 aromatic. Examples of R1 are unfluorinated, partially fluorinated, or fully fluorinated methyl, ethyl, propyl, isopropyl, cyclopentyl, cyclohexyl, methylcyclohexyl, phenyl, and tolyl.
R2 can be one or more of a C6 to C12 substituted or unsubstituted aromatic such as phenyl, tolyl, or pentamethylphenyl, a fluorinated straight chain, branched chain or cycloalkyl up to C8F15, such as trifluoromethyl and pentafluoroethyl, or partially or fully fluorinated aromatic group, such as C6H3F2 or C6F5.
R3 can be one or more of R2, a C1 to 6 linear or branched alkyl, or a C3 to C8 substituted or unsubstituted cycloalkyl, such as methyl, cyclohexyl, phenyl, or tert-butyl.
R4 can be one or more of a C1 to C6 linear or branched alkyl, C3 to C8 substituted or unsubstituted cycloalkyl, or C6 to C12 substituted or unsubstituted aromatic and can be partially or fully fluorinated. Examples of R4 are unfluorinated, partially fluorinated, or fully fluorinated methylene, ethylene, and phenylene.
Examples of compounds having structure VII are disilane or trisilane containing alkoxy ligands, such as H(CH3O)(CH3)Sixe2x80x94Si(CH3)(OCH3)H.
Structures I and II contain monodentate alkoxy groups, with one Sixe2x80x94O bond per OR2 or OR3 group. In structure II, the R4 alkoxy group can be bidentate with one Sixe2x80x94O bond and one Sixe2x80x94C bond per R4 group. In structure IV, R4 is a bidentate alkoxy structure with two Sixe2x80x94O bonds per R4 group. In structures V and VI, the R4 alkoxy group forms bridged structures with two Sixe2x80x94O bonds.
A major advantage in using silyl ethers of this invention, having Sixe2x80x94Oxe2x80x94C bonds, to dope organic or organofluorine groups into the ILD film, instead of silanes having only Sixe2x80x94C and Sixe2x80x94H bonds, is that Sixe2x80x94Oxe2x80x94C bonds are more convenient to form than Sixe2x80x94C bonds. In addition, starting materials for silyl ethers are readily available and inexpensive, and silyl ethers are safer to handle than silanes. Most of the silyl ethers described in this invention are flammable liquids, while silane (SiH4) is a pyrophoric gas, and methyl-, dimethyl-, and trimethyl-silane are highly flammable gases.
The organosilicon precursors containing reactive groups have the general structure R14-xSiR5x in which x is an integer of 1 to 3, R1 is as described above for structures I-VII, and R5 is a reactive group. A reactive group is typically defined as chemical bond(s) between two (or more) atoms which can be broken using a minimal amount of energy, is strained, or is not in a thermodynamically preferred configuration, and has a propensity to form new chemical bonds or crosslinked structures with other chemical species. Reactive groups can aid in the crosslinking of the deposited film which enhances the thermal stability and mechanical strength of the ILD film. Examples of reactive side groups include C2 to C10 epoxides such as ethylene oxide or 2-ethyloxirane, C2 to C8 carboxylates such as methyl acetate or ethyl acetate, C2 to C8 alkynes such as propyne, ethyne, and phenylethyne, C4 to C8 dienes such as 1,3-butadiene, 1,4 octadiene or 1,3 cyclopentadiene, C3 to C5 strained rings such as cyclopropane or 2-cyclobutene, and C4 to C10 organic groups, such as tert-butyl, tert-butyloxide, or adamantane, that can sterically hinder or strain the organosilicon precursor. Examples of organosilicon compounds containing reactive groups are trimethylsilylacetylene, 1-(trimethylsilyl)-1,3-butadiene, trimethylsilylcyclopentadiene, trimethylsilylacetate, and di-tert-butyoxydiacetoxysilane.

Organosilicon precursors for interlayer dielectric films with low dielectric constants


An insulating varnish comprising a resin component, electrical insulating whiskers, and if necessary, one or more additives such as an ion adsorbent, and/or an organic reagent for preventing injury from copper, produced by adding the additives to the resin component and the whiskers, or filtering the whiskers, or milled by using a beads mill or a three-roll mill, or the like, is excellent for producing a multilayer printed circuit board having high wiring density, high reliability and excellent other electrical properties.

The present invention relates to processes for producing electrical insulating varnishes used for insulating materials or adhesive films for printed circuits boards which can comply with the request for smaller thickness and higher wiring density of such circuit boards on which electronic parts are mounted, and multilayer printed circuit boards made by using such insulating varnishes.
Printed circuit boards are usually produced by forming circuits on copper-clad laminates obtained by laminating copper foils and prepregs and molding the laminates by heating under pressure.
Multilayer printed circuit boards are manufactured by forming circuits on the surfaces of multilayer copper-clad laminates having inner layer circuits formed therein, which laminates have been obtained by hot-pressure laminating said printed circuit boards, or those boards and copper foils, with prepregs interposed therebetween.
As prepregs for printed circuit boards, there have been used glass cloth prepregs obtained by impregnating a resin in glass cloth and drying the resin into a half-curedstate. In manufacture of multilayer printed circuit boards, adhesive films made of half-cured resins having film forming properties, which are prepregs containing no glass cloth, such as disclosed in JP-A-6-200216 and JP-A-6-242465, or adhesive films having a copper foil formed on one side, such as proposed in JP-A-6-196862, have been used beside said glass cloth prepregs.
When the term "film forming properties" is used in this specification, it means the quality of the resin which is unsusceptible to such trouble as cracking or chip-off during transport, cutting, lamination and other works of prepregs and to troubles in the ensuing hot-pressure molding, such as abnormal diminution of the interlayer insulating layers at the areas where the inner layer circuits are present, lowering of interlayer insulation resistance, and short-circuiting.
The recent years have seen sharp acceleration of the tendency to smaller size and weight, higher performance and lower production cost of electronic devices, consequently calling for higher packaging density, smaller thickness, higher reliability and lower cost of the printed circuit boards used in such electronic devices.
For realizing higher density of printed circuit boards, finer wiring is essential, and this requires good surface flatness and high dimensional stability. Formation of fine through-holes and/or interstitial via holes (IVH) and good laser drilling workability are also demanded. For obtaining higher surface flatness, it is necessary to enhance fluidity of the resin during multilayer laminate molding, and this purpose can best be met by use of a thermosetting resin such as epoxy resin.
Epoxy resins, however, show high fluidity because of low molecular weight at the stage before molding and are incapable of forming a sheet-shaped insulating material. Hitherto, therefore, prepregs prepared by impregnating an insulating resin in a reinforcing base material such as glass cloth have been used for forming the insulating layers, but it has become hardly possible for these conventional prepregs to answer to the above requirements.
The glass cloth generally used for prepregs at present has the spaces between the yarns (glass fiber bundles) enlarged proportionally as its thickness is reduced. Therefore, the smaller the thickness of the cloth, the higher becomes the probability of occurrence of a phenomenon in which yarns are bent or the warp and weft, which normally ought to cross at right angles, fail to cross at right angles. This phenomenon tends to cause an abnormal dimensional change or warping after hot pressure molding. Further, the smaller the thickness of glass cloth, the greater are the spaces between the yarns, hence the lower becomes the volume fraction of prepreg fibers, resulting in a reduced rigidity of the interlayer insulating layer. This tends to enlarge dimensional deflection in the steps, such as parts packaging step, after working of outer layer circuits.
The minimal permissible thickness of currently used glass cloth is 30 .mu.m, and the thickness of prepregs using glass cloth of such minimal thickness is about 40 .mu.m. If the resin proportion is reduced for making the prepreg thickness smaller than this, resin filling of the recesses of inner layer circuits is adversely affected, allowing formation of voids. Also, thickness reduction of glass cloth beyond the above limit invites corresponding lowering of strength of the cloth itself, so that the glass cloth becomes liable to break in the step of immersion of the glass cloth in the resin, making it difficult to produce the desired prepregs. Another problem of the multilayer printed circuit boards made by using these glass cloth-based prepregs is that there tends to take place center deflection or lost of core center due to ununiform distribution of glass cloth during fine drilling, resulting in break of the drill. Due to the presence of glass fibers, laser drilling efficiency is low and unevenness of inner layer circuits tends to emerge on the surface to degrade surface flatness of the board. Therefore, use of the presently available glass cloth-based prepregs can not accommodate the mounting requirements for higher packaging density and smaller thickness of the multilayer printed circuit boards.
On the other hand, the adhesive films or copper-foiled adhesive films made of prepregs containing no glass cloth have the advantage of enabling production of the circuit boards with smaller thickness and are also prominent in fine drilling workability, laser drilling efficiency and surface flattening performance. However, the multilayer printed circuit boards made of these prepregs are intolerably low in rigidity because of absence of glass cloth base in the outer insulating layers. This low rigidity is most manifest under high temperatures and causative of positional deflection during packaging of parts. It is also responsible for poor wire bonding workability. Further, because of large thermal expansion coefficient due to the absence of glass cloth in the outer insulating layers, the difference in thermal expansion between the board and the packaged parts is large, hence reliability of connection to the packaged parts is low. Also, cracking or break tends to occur at the solder joints due to thermal expansion or contraction of the board as it is heated or cooled. Thus, with the adhesive films or copper-foiled adhesive films made of the currently used glass cloth-free prepregs, it is hardly possible to comply with the rising request for higher packaging density and smaller size of the multilayer printed circuit boards.
As a new insulating material that can meet the requests for higher packaging density, smaller size, higher reliability and lower cost of multilayer printed circuit boards, which could not be attained with the conventional prepregs, there has been offered a sheet-like insulating material produced by casting a varnish containing no glass cloth and having electrical insulating whiskers dispersed in the insulating resin for shape retention. It was found, however, that this insulating material also had the problems. For instance, for dispersing electrical insulating whiskers in the insulating resin, a specific mixing equipment is required, and it is also essential to conduct an appropriate surface treatement of the electrical insulating whiskers used. It was found that even if these requirements are met, the produced insulating material could still cause improper insulation when it is used for multilayer printed circuit boards.
The electrical insulating whiskers have a tendency to aggregate in the dry state, so that for properly dispersing these whiskers in the insulating resin, it is necessary to use a specific mixing equipment or to apply a proper surface treatment on the whiskers. Even if these requirements could have duly been dealt with, it is still impossible to perfectly eliminate the aggregates of these whiskers.
In the multilayer printed circuit boards, the insulating layers are provided with a greater thickness than the inner layer circuits for ensuring filling of surface unevenness of the inner layer circuits. For reducing the overall thickness of the multilayer printed circuit boards, it is desirable to lessen the insulating layer thickness as much as possible within limits that allow retention of required insulation. In view of this, the insulating layer thickness is usually set to be 25 to 100 .mu.m. Regarding the size (length) of the aggregates of electrical insulating whiskers, when we procured the commercial whiskers by designating their average length to be 30 .mu.m, the procured whiskers included those having a length exceeding 50 .mu.m, some of them being longer than 300 .mu.m. In case a sheet-shaped insulating material using these electrical insulating whiskers is applied to multilayer printed circuit boards, a varnish containing such lengthy electrical insulating whiskers or the aggregates thereof mentioned above is used, so that these whiskers or the aggregates thereof tend to contact each othere between the conductors to cause improper insulation such as observed when using conductive anodic filaments (CAF).

Production of insulating varnishes and multilayer printed circuit boards using these varnishes


A contactor for liquids with gases, solids or liquids which can also serve as an entrainment separator for separating liquids from gases and solids from gases, includes a housing providing an inlet at one end and an outlet at the opposed end, means to introduce a mist or spray of liquid and positioned between said inlet and an adjustable surface (preferably planar) providing a face facing the inlet and the means for introducing said liquid, and an opposed face, an annular deflector beneath the planar surface attached to the housing and extending inward of the housing and positioned relative to the planar surface to provide an opening between the planar surface and annular deflector, means to adjust the position of the planar surface relative to the annular deflector, a tube attached to the opposed face of the planar surface and extending downward of the inlet, a funnel providing a downward extending spout positioned below the tube, means providing flow of liquid in the funnel past the tube and to the spout, and a gas outlet extending through the side of the housing.

The present invention relates to an entrainment separator. More particularly, it relates to an entrainment separator for the separation of entrained solids or liquids from gases, preferably entrained liquids. It also relates for a contactor-separator wherenby a mist or drops of a liquid can be contacted with the gaseous stream to further remove entrained liquids, solids and/or soluble or reactive components of the gaseous stream (e.g., SO.sub.2 removal by a caustic wash).
It has been well known that dispersions of liquids in gases and gases in liquids are always fundamentally unstable mixtures. Left to themselves, they will generally separate into massive collections of the component phases. In many instances, however, such natural separation occurs over a long period of time. For industrial uses and independent of origin of the dispersion, whether intentional or inadvertent, the gas-liquid dispersions generally are always ultimately separated. The separation may consist merely of removal of the aggregated and collected phases, or it may involve aggregation and collection as well as removal. Often the rate at which the process of separation would occur naturally is slow and uneconomical. In such cases the separation operation may be enhanced by the artificial acceleration of the natural process.
There are many reasons why gas-liquid dispersions should be separated. The quality of a process stream or of a product can suffer unless adulterating material in the form of another dispersed phase is removed. The efficiency of staged mass transfer operations can be reduced if there is mechanical carryover of a dispersed phase with the continuous stream from one stage to the next. Valuable material can be lost from a system because of incomplete separation of dispersed material. With improper separation of the gas-liquid dispersion, there can be intrusion of an unwanted phase into equipment along the line of processing which may result in poort performance or damage to the equipment. A discharge of a gas-liquid dispersion from a stack can result in atmospheric pollution and possible destruction of property.
Many methods are employed to separate gas-liquid dispersion systems. Such methods include: gravitational, inertial, absorption, dilution, physicochemical, electrical, and thermal. Often more than one method is effective and the methods may be combined for synergistic effect. Many separators employing the above systems and procedures are the product of invention or accumulated experience and have never been completely described scientifically. Many such methods and apparatus for separating entrained liquids from gases are designed specifically for the conditions peculiar to a given gas-liquid dispersion system and the mechanical apparatus also peculiar to that system.


Novel N-(mercaptoacyl)peptidyl compounds are useful as inhibitors of matrix metalloendoproteinases which degrade major components of articular cartilage and basement membranes causing degenerative diseases such as arthritis, periodontal disease, corneal ulceration, are described. For example, N-(2-thiomethyl-4-phenyl-butanoyl)-L-leucinamide was prepared and its inhibitory activity against stromelysin was tested in vitro.

Novel N-(mercaptoacyl)peptidyl compounds of formula (I) are found to be useful inhibitors of matrix metalloendoproteinase-mediated diseases including osteoarthritis, rheumatoid arthritis, septic arthritis, tumor invasion in certain cancers, periodontal disease, corneal ulceration, proteinuria, dystrophobic epidermolysis bullosa, coronary thrombosis associated with atherosclerotic plaque rupture, and aneurysmal aortic disease. The matrix metalloendoproteinases are a family of zinc-containing proteinases including but not limited to stromelysin, collagenase, and gelatinase, that are capable of degrading the major components of articular cartilage and basement membranes. The inhibitors claimed herein may also be useful in preventing the pathological sequelae following a traumatic injury that could lead to a permanent disability. These compounds may also have utility as a means for birth control by preventing ovulation or implantation. ##STR1##
The disability observed in osteoarthritis (OA) and rheumatoid arthritis (RA) is largely due to the loss of articular cartilage. No therapeutic agent in the prior art is known to prevent the attrition of articular cartilage in these diseases.
"Disease modifying antirheumatic drugs" (DMARD), i.e., agents capable of preventing or slowing the ultimate loss of joint function in OA and RA are widely sought. Generic nonsteroidal antiinflammatory drugs (NSAIDs) may be combined with such agents to provide some relief from pain and swelling.
Stromelysin (aka. proteoglycanase, matrix metalloproteinase-3, MIMP-3, procollagenase activator, "transin"), collagenase (aka. interstitial collagenase, matrix metalloproteinase-1, MMP-1, Type II collagenase), and gelatinase (aka. type IV collagenase, matrix metalloproteinase-2, MMP-2, 72kDa-gelatinase or type V collagenase, matrix metalloproteinase-9, MMP-9, 95kDa-gelatinase) are metalloendoproteinases secreted by fibroblasts and chondrocytes, and are capable of degrading the major connective tissue components of articular cartilage or basement membranes. Elevated levels of both enzymes have been detected in joints of arthritic humans and animals: K. A. Hasty, R. A. Reife, A. H. Kang, J. M. Stuart, "The role of stromelysin in the cartilage destruction that accompanies inflammatory arthritis", Arthr. Rheum., 33,388-97 (1990); S. M. Krane, E. P. Amento, M. B. Goldring, S. R. Goldring, and M. L. Stephenson, "Modulation of matrix synthesis and degradation in joint inflammation", in The Control of Tissue Damage", A. B. Glauert (ed.), Elsevier Sci. Publ., Amsterdam, 1988, Ch. 14, pp 179-95; A. Blanckaert, B. Mazieres, Y. Eeckhout, G. Vaes, "Direct extraction and assay of collagenase from human osteoarthrtic cartilage", Clin. Chim. Acta, 185 73-80 (1989). Each enzyme is secreted from these cells as an inactive proenzyme which is subsequently activated. There is evidence that stromelysin may be the in vivo activator for collagenase and gelatinase, implying a cascade for degradative enzyme activity: A. Ho, H. Nagase, "Evidence that human rheumatoid synovial matrix metalloproteinase 3 is an endogenous activator of procollagenase", Arch Biochem Biophys., 267,211-16 (1988); G. Murphy, M. I. Crockett, P. E. Stephens, B. J. Smith, A. J. P. Docherty, "Stromelysin is an activator of procollagenase", Biochem. J., 248, 265-8 (1987); Y. Ogata, J. J. Enghild, H. Nagase, "Matrix metalloproteinase 3 (stromelysin) activates the precursor for human matrix metalloproteinase 94, J. Biol. Chem., 267, 3581-3584 (1992). Inhibiting stromelysin could limit the activation of collagenase and gelatinase as well as prevent the degradation proteoglycan.
That stromelysin inhibition may be effective in preventing articular cartilage degradation has been demonstrated in vitro by measuring the effect of matrix metalloendoproteinase inhibitors on proteoglycan release from rabbit cartilage explants: C. B. Caputo, L. A. Sygowski, S. P. Patton, D. J. Wolanin, A. Shaw, R. A. Roberts, G. DiPasquale, J. Orthopaedic Res., 6, 103-8 (1988).
There is an extensive literature on the involvement of these metalloproteinases in arthritis, but there is very little to guide one in developing a specific inhibitor for each enzyme.
In preliminary studies of rabbit proteoglycanase with substrates and inhibitors, little was found to indicate the enzyme's requirements for hydrolysis or inhibition beyond a preference for hydrophobic residues at the P.sub.1 ' position: A. Shaw, R. A. Roberts, D. J. Wolanin, "Small substrates and inhibitors of the metalloproteoglycanase of rabbit articular chondrocytes", Adv. Inflam. Res., 12, 67-79 (1988). More extensive studies with a series of substrates revealed that stromelysin will tolerate nearly every amino acid residue around the scissile bond: G. B. Fields, H. Brikedal-Hansen, H. E. Van Wart, unpublished results presented at the Matrix Metalloproteinase Conference, Sept. 1989, Sandestin Fla.
Human rheumatoid synovial collagenase has been shown to share .about.50% homology with human stromelysin: S. E. Whitham, G. Murphy, P. Angel, H. J. Rahmsdorf, B. J. Smith, A. Lyons, T. J. R. Harris, J. J. Reynolds, P. Herrlich, A .J. P. Docherty, "Comparison of human stromelysin and collagenase by cloning and sequence analysis", Biochem. J., 240,913-6 (1986). Many collagenase inhibitors have been designed around the cleavage site of the .alpha.-chain sequence of Type II collagen: W. H. Johnson, N. A. Roberts, N. Brokakoti, "Collagenase inhibitors: their design and potential therapeutic use", J. Enzyme Inhib., 2,1-22 (1987). One such inhibitor, N-[3-(benzyloxycarbonyl) amino-1-carboxy-n-propyl]-L-leucyl-O-methyl-L-tyrosine, N-methylamide, prepared at G. D. Searle, Inc., and shown to be a potent inhibitor of human rheumatoid synovial collagenase (IC.sub.50 =0.8 .mu.M), was also found to inhibit rabbit bone proteoglycanase (IC.sub.50 =0.5 .mu.M): J. M. Delaisse, Y. Eeckhout, C. Sear, A. Galloway, K. McCullagh, G. Vaes, "A new synthetic inhibitor of mammalian tissue collagenase inhibits bone resorption in culture", Biochem. Biophys. Res. Commun., 133, 483-90 (1985).
Gelatinase (MR .about.72,000) has been isolated from rheumatoid fibroblasts: Y. Okada, T. Morodomi, J. J. Enghild, K. Suzuki, A. Yasui, I. Nakanishi, G. Salvesen, H. Nagase, "Matrix metalloproteinase 2 from human rheumatoid synovial fibroblasts", Eur. J., Biochem., 194, 721-30 (1990). The synthesis of the proenzyme is not coordinately regulated with the other two metalloproteinases and its activation may also be different. The role of gelatinase in the tissue destruction of articular cartilage appears different from the other two enzymes and, therefore, its inhibition may provide additional protection from degradation. A higher molecular weight gelatinase (MR .about.95,000; aka. type-V collagenase, matrix metallo-proteinase-9, MMP-9) is also secreted by fibroblasts and monocytes and may be involved in cartilage degradation.
From the significant proportion of homology between human fibroblast collagenase, stromelysin, and gelatinase it is expected that a compound that inhibits one enzyme may have a similar effect on all of them.
Compounds that inhibit collagenase, which possess structural portions akin to those of the instant invention include those encompassed by U.S. Pat. No. 5,109,000 issued Apr. 28, 1992; U.S. Pat. No. 4,595,700, issued Jun. 17, 1986; U.S. Pat. No. 4,371,466, issued Feb. 1, 1983. Also included are compounds encompassed by claims in foreign applications EP423,943, EP273,689, EP322184, EP185,380, and WO8806890.
It is believed that stromelysin and collagenase inhibitors have utility in preventing articular cartilage damage associated with septic arthritis. Bacterial infections of the joints can elicit an inflammatory response that may then be perpetuated beyond what is needed for removal of the infective agent resulting in permanent damage to structural components. Bacterial agents have been used in animal models to elicit an arthritic response with the appearance of proteolytic activities. See J. P. Case, J. Sano, R. Lafyatis, E. F. Remmers, G. K. Kumkumian, R. L. Wilder, "Transin/stromelysin expression in the synovium of rats with experimental erosive arthritis", J. Clin Invest., 84, 1731-40 (1989); R. J. Williams, R. L. Smith, D. J. Schurman, "Septic Arthritis: Staphylococcal induction of chondrocyte proteolytic activity", Arthr. Rheum., 33, 533-41 (1990).
It is also believed that inhibitors of stromelysin, collagenase, and gelatinase will be useful to control tumor metastasis, optionally in combination with current chemotherapy and/or radiation. See L. M. Matrisian, G. T. Bowden, P. Krieg, G. Furstenberger, J. P. Briand, P. Leroy, R. Breathnach, "The mRNA coding for the secreted protease transin is expressed more abundantly in malignant than in benign tumors", Proc. Natl. Acad. Sci., U.S.A, 83, 9413-7 (1986); S. M. Wilhelm, I. E. Collier, A. Kronberger, A. Z. Eisen, B. L. Marmer, G. A. Grant, E. A. Bauer, G. I. Goldberg, "Human skin fibroblast stromelysin: structure, glycosylation, substrate specificity, and differential expression in normal and tumorigenic cells", Ibid., 84, 6725-29 (1987); Z. Werb et al., Signal transduction through the fibronectin receptor induces collagenase and stromelysin gene expression, J. Cell Biol., 109, 872-889 (1989); L. A. Liotta, C. N. Rao, S. H. Barsky, "Tumor invasion and the extracellular matrix", Lab. Invest., 49, 636-649 (1983); R. Reich, B. Stratford, K. Klein, G. R. Martin, R. A. Mueller, G. C. Fuller, "Inhibitors of collagenase IV and cell adhesion reduce the invasive activity of malignant tumor cells", in Metastasis: Ciba Foundation Symposium; Wiley, Chichester, 1988, pp. 193-210.
Secreted proteinases such as stromelysin, collagenase, and gelatinase play an important role in processes involved in the movement of cells during metastasic tumor invasion. Indeed, there is also evidence that the matrix metalloproteinases are overexpressed in certain metastatic tumor cell lines. In this context, the enzyme functions to penetrate underlying basement membranes and allow the tumor cell to escape from the site of primary tumor formation and enter circulation. After adhering to blood vessel walls, the tumor cells use these same metalloendoproteinases to pierce underlying basement membranes and penetrate other tissues, thereby leading to tumor metastasis. Inhibition of this process would prevent metastasis and improve the efficacy of current treatments with chemotherapeutics and/or radiation.
These inhibitors should also be useful for controlling periodontal diseases, such as gingivitis. Both collagenase and stromelysin activities have been isolated from fibroblasts isolated from inflammed gingiva: V. J. Uitto, R. Applegren, P. J. Robinson, "Collagenase and neutral metalloproteinase activity in extracts of inflamed human gingiva", J. Periodontal Res., 16, 417-424(1981). Enzyme levels have been correlated to the severity of gum disease: C. M. Overall, O. W. Wiebkin, J. C. Thonard, "Demonstration of tissue collagenase activity in vivo and its relationship to inflammation severity in human gingiva", J. Periodontal Res., 22, 81-88 (1987).
Proteolytic processes have also been observed in the ulceration of the cornea following alkali burns: S. I. Brown, C. A. Weller, H. E. Wasserman, "Collagenolytic activity of alkali-burned corneas", Arch. Opthalmol., 81, 370-373 (1969). Mercapto-containing peptides inhibit the collagenase isolated from alkali-burned rabbit cornea: F. R. Burns, M. S. Stack, R. D. Gray, C. A. Paterson, Invest. Opthalmol., 30, 1569-1575 (1989). Treatment of alkali-burned eyes or eyes exhibiting corneal ulceration as a result of infection with combination with sodium citrate or sodium ascorbate and/or antimicrobials may be effective in preventing developing corneal degradation.
Stromelysin has been implicated in the degradation of structural components of the glomerular basement membrane (GBM) of the kidney, the major function of which is to restrict passage of plasma proteins into the urine; W. H. Baricos, G. Murphy, Y. Zhou, H. H. Nguyen, S. V. Shah, "Degradation of glomerular basement membrane by purified mammalian metalloproteinases", Biochem. J., 254, 609-612 (1988). Proteinuria, a result of glomerular disease, is excess protein in the urine caused by increased permeability of the GBM to plasma proteins. The underlying causes of this increased GBM permeability are unknown, but proteinases including stromelysin may play an important role in glomerular diseases. Inhibition of this enzyme may alleviate the proteinurea associated with kidney malfunction.
Inhibition of stromelysin activity may prevent the rupturing of atherosclerotic plaques leading to coronary thrombosis. The tearing or rupture of atherosclerotic plaques is the most common event initiating coronary thrombosis. Destabilization and degradation of the connective tissue matrix surrounding these plaques by proteolytic enzymes or cytokines released by infiltrating inflammatory cells has been proposed as a cause of plaque fissuring. Such tearing of these plaques can cause an acute thrombolytic event as blood rapidly flows out of the blood vessel. High levels of stromelysin RNA message have been found to be localized to individual cells in atherosclerotic plaques removed from heart transplant patients at the time of surgery: A. M. Henney, P. R. Wakeley, M. J. Davies,. K. Foster, R. Hembry, G. Murphy, S. Humphries, "Localization of stromelysin gene expression in atherosclerotic plaques by in situ hybridization", Proc. Nat'l. Acad. Sci. U.S.A, 88, 8154-8158 (1991). Inhibition of stromelysin by these compounds may aid in preventing or delaying the degradation of the connective tissue matrix that stabilizes the atherosclerotic plaques, thereby preventing events leading to acute coronary thrombosis.
It is also believed that inhibitors of matrix metalloproteinases would have utility in treating degenerative aortic disease associated with thinning of the medial aortic wall. Aneurysms are often associated with atherosclerosis in this tissue. Increased levels of the degradative activities of the matrix metalloproteinases have been identified in patients with aortic aneurysms and aortic stenosis: N. Vine, J. T. Powell, "Metalloproteinases in degenerative aortic diseases", Clin. Sci., 81, 233-9 (1991). Inhibition of these enzymes may aid in preventing or delaying the degradation of aortic tissue, thus preventing events leading to acute and oftentimes fatal aortic aneurysms.
It is also believed that specific inhibitors of stromelysin and collagenase should be useful as birth control agents. There is evidence that expression of metalloendoproteinases, including stromelysin and collagenase, is observed in unfertilized eggs and zygotes and at further cleavage stages and increased at the blastocyst stage of fetal development and with endoderm differentiation: C. A. Brenner, R. R. Adler, D. A. Rappolee, R. A. Pedersen, Z. Werb, "Genes for extracellular matrix-degrading metalloproteinases and their inhibitor, TIMP, are expressed during early mammalian development", Genes & Develop., 3, 848-59 (1989). By analogy to tumor invasion, a blastocyst may express metalloproteinases in order to penetrate the extracellular matrix of the uterine wall during implantation. Inhibition of stromelysin and collagenase during these early developmental processes should presumably prevent normal embryonic development and/or implantation in the uterus. Such intervention would constitute a novel method of birth control. In addition there is evidence that collagenase is important in ovulation processes. In this example, a covering of collagen over the apical region of the follicle must be penetrated in order for the ovum to escape. Collagenase has been detected during this process and an inhibitor has been shown to be effective in preventing ovulation: J. F. Woessner, N. Morioka, C. Zhu, T. Mukaida, T. Butler, W. J. LeMaire "Connective tissue breakdown in ovulation", Steroids, 54, 491-499 (1989). There may also be a role for stromelysin activity during ovulation: C. K. L. Too, G. D. Bryant-Greenwood, F. C. Greenwood, "Relaxin increases the release of plasminogen activator, collagenase, and proteo-glycanase from rat granulosa cells in vitro", Endocrin., 115, 1043-1050 (1984).
Collagenolytic and stromelysin activity have also been observed in dystrophobic epidermolysis bullosa: A. Kronberger, K. J. Valle, A. Z. Eisen, E. A. Bauer, J. Invest. Dermatol., 79, 208-211 (1982); D. Sawamura, T. Sugawara, I. Hashimoto, L. Bruckmer-Tuderman, D. Fujimoto, Y. Okada, N. Utsumi, H. Shikata, Biochem. Biophys. Res. Commun., 174, 1003-8 (1991). Inhibition of metalloendoproteinases should limit the rapid destruction of connective components of the skin.
In addition to extracellular matrix comprising structural components, stromelysin can degrade other in vivo substrates including the inhibitor al-proteinase inhibitor and may therefore influence the activities of other proteinases such as elastase: P. G. Winyard, Z. Zhang, K. Chidwick, D. R. Blake, R. W. Cartell, G. Murphy, "Proteolytic inactivation of human al-antitrypsin by human stromelysin", FEBS Letts., 279, 1, 91-94 (1991). Inhibition of the matrix metalloendoproteinases may potentiate the antiproteinase activity of these endogenous inhibitors.

N-(mercaptoacyl) peptidyl derivatives as antidegenerative agents


A completion system for a well includes a tubing hanger movable into a landed position within an internal bore of the completion system. The tubing hanger includes a hanger bore formed through the tubing hanger, an auxiliary passage formed through the tubing hanger outside of the hanger bore, and a shuttle rod valve including a rod movable in a cavity that is capable of being in fluid communication with the auxiliary passage to control the flow of fluid through the auxiliary passage.

To meet the demand for natural resources, companies often invest significant amounts of time and money in searching for and extracting oil, natural gas, and other subterranean resources from the earth. Particularly, once a desired resource is discovered below the surface of the earth, drilling and production systems are often employed to access and extract the resource. These systems may be located onshore or offshore depending on the location of a desired resource. Further, such systems generally include a completion system that includes a wellhead assembly through which the resource is extracted. These completion systems may include a wide variety of components, such as various casings, hangers, valves, fluid conduits, and the like, that control drilling and/or extraction operations.
One type of completion assembly includes a wellhead with one or more strings of casing supported by casing hangers in the wellhead. Attached to the wellhead is a tubing spool. A tubing hanger secured to a string of tubing lands in the tubing spool above the wellhead or directly in the wellhead. The tubing hanger has a plurality of passages that provide access through the tubing hanger for hydraulic fluid or electrical lines to operate and control equipment located downhole, such as safety valves, temperature sensors, or chemical injection units, for instance.
A tree (sometimes referred to in the oil and gas industry as a christmas tree) may be installed on top of the tubing spool. The tree typically has a bore in fluid communication with the tubing string and tubing hanger and valves for controlling flow through the well. The passages in the tubing hanger connect with passages in the tree, which may provide access to a control unit in the tree.


An internal lapping tool comprises a steel mandrel having a cast iron generally cylindrical head welded on the front and thereof. The head is formed with two spaced arcuate lapping faces opposite a longitudinal slot which carries a cast iron insert providing a third arcuate lapping face. A wedge member slideably mounted for longitudinal movement in the mandrel provides for moving the insert radially. The three arcuate lapping faces on the rotating head provide a three point contact on the wall of a hole being lapped, thereby effectively producing a round mating form as desired for lapping. Futhermore, as the arcuate faces wear and the hole enlarges during the lapping operation, the arcuate lapping faces are kept snugly at all times against the cylindrical wall of the hole being lapped by the longitudinal positive feed of the wedge member.

This invention relates to machine tools and more particularly to adjustable lapping tools for lapping the inside diameters of small holes to extremely close tolerances.
In the continuing effort to increase the life of rotating parts which are subject to wear, there is a need to be able to quickly size and finish holes by lapping them to a greater accuracy than heretofore provided. For example, it is now required that holes for valves and other hydraulic parts in the aircraft and space industries be lapped to an accuracy of as great as five to ten millionths of an inch so as to create a maximum percentage of bearing area. Thus, as the tolerances on the job become closer, it becomes more essential that the tooling used for internal lapping comes closer to meeting the ideal requirement of the bore.
Previously in the art, internal lapping tools have been made by providing a cast iron sleeve with a tapered hole therethrough and a helical slot therealong. The tapered hole enables the sleeve to be mounted on a mated tapered mandrel. The advancement of the sleeve on the tapered mandrel to enlarge its diameter during the coarse of the lapping operation is accomplished by manually striking the end of a lap expander positioned adjacent the sleeve or by manually operating a screw expansion device. Although this appears to provide a uniform enlargement of the diameter throughout the cylindrical lapping sleeve as needed for accurate lapping, actually such a construction and structural arrangement is ineffective when it is desired to accurately size the internal wall of a hole to a tolerance of a few millionths of an inch. This is because of minute variations of expansion that such uncoiling produces along the length of the sleeve. Furthermore, such a lapping tool has the disadvantage that the cylindrical lapping surface of the sleeve is not continually kept snugly up against the wall of the hole as the sleeve wears and the hole enlarges but must be incrementally adjusted every so often by manually striking the end of the lap expander, for example.


The invention shows how diodes in a modern semiconductor process can be used as a very compact switch element in a Programmable Read Only Memory (PROM) using common integrated circuit fuse elements such as polysilicon and metal. This compact switch element allows very dense PROM arrays to be realized since diodes have the highest conduction density of any semiconductor device. The high conduction density is used to provide the relatively high current needed to blow the fuse element open. Since MOSFETs are typically used as fuse array switch elements, a relatively large area is required for the MOSFET to reach the current needed to blow the fuse element. Since diodes are two terminal switch elements unlike MOSFETs which are three terminal devices, methods are outlined on how to both read and write the arrays using this two terminal switch.

1. Field of the Invention
The present invention is generally in the field of integrated circuits and, specifically, the invention is in the field of fuse based One Time Programmable (OTP) ROMs or PROMs.
2. Prior Art
Fuse based Programmable Read Only Memories (PROMs) were common up until the 80's when they were largely replaced by UV erasable EPROMs. For example, in U.S. Pat. No. 4,701,695 a metal fuse based PROM is shown in which an NPN bipolar transistor is used to select a fuse in an array of fuses. The fuse is blown or opened with about 50 mA of current at a voltage of 3V. The term program refers to changing the electrical resistive state of fuses in a PROM array to be representative of a desired bit pattern.
There is, however, a need to embed some amount of programmable read only memory in standard CMOS circuits. The PROM can be used to encode configuration information, date codes, serial numbers, etc. Ideally, the programmable memory or PROM can be made in a generic CMOS process without adding any additional processing steps for the PROM.


A spark igniter for gas grills includes a gas collector mountable on the grill housing adjacent a gas burner and having a collector inlet for receiving gas from the burner. An adjustable mounting device attached to the collector provides vertical adjustment of the collector for positioning the collector inlet at a proper elevation for receiving gas from the burner. The adjustable mounting device also serves to attach an electrode to the collector and position the electrode tip in a predetermined location for defining a spark gap.

The invention relates generally to igniters for gas burners and, more particularly, to arrangements for adjustably mounting such igniters adjacent a gas burner. The invention is particularly applicable for use with spark igniters on gas grills and will be particularly described with reference thereto. However, it will be appreciated that the improved mounted arrangement can be used on other igniters.
Gas grills for domestic use in cooking food include a dished housing having a housing base and a gas burner is mounted within the housing adjacent the base. A spark igniter is mounted to the housing base by a bracket. The position of the burner relative to the housing base varies from one grill manufacturer to another, and also varies with different models of the same manufacturer. Thus, a large number of different mounting brackets are required for properly locating the spark igniter relative to the burner. The difficulty with adjusting the position of the spark igniter in prior arrangements frequently results in a device which does not operate satisfactorily. Using a different bracket for each different make and model of grill is very expensive and still provides no final adjustment.
It is therefore the primary object of the present invention to provide a spark igniter with an adjustable mounting arrangement for properly locating same relative to a gas burner regardless of the make and model of the grill.
It is a further object of the invention to provide a spark igniter with an adjustable mounting device which also functions as the attachment and locator for an electrode forming part of a spark gap.
It is also an object of the invention to provide a spark igniter with an adjustable mounting arrangement which is very simple and economical to manufacture and assemble.


In a meeting or group event, people having a portable device, such as a cell phone or pager, may wish to be discretely notified when an important message is received, an urgent call comes in from a selected person or a selected group of people, or to be alerted to an upcoming important event without any audible alert to disturb the meeting or group event. To convey such a notification, a tactile alert is provided by vibrating the portable device according to a unique vibration pattern associated with the received communication. When a communication is received, a group identification (ID) is assigned based on the communication being a member of a classified group of source addresses. The portable device associates the group ID with a unique vibration pattern. To provide the alert, the portable device is vibrated according to the unique vibration pattern.

An incoming message or call to a mobile communication device, such as a cell phone, pager, personal data assistant (PDA), portable inventory tool, notebook computer, or the like, may trigger an audible alert, such as a ringing sound for any of a wide variety of ringtones, or the like. The ringing sound or ringtone, originally used in cable attached telephones, was commonly of a single frequency and duration. On mobile phones, ringtones can be customized to differentiate the ring of one ringing phone from the different rings of multiple phones and to personalize the ringtone to a user's preference.
Mobile devices may also allow a user to associate specific ringtones with specific entries in a personalized phonebook stored on the mobile device. The ringtones may be stored as music or as other audible sounds, such as the sound of a waterfall, traditional ringing sounds, special effect sounds, and the like. The flexibility to select ringtones and the capacity to store multiple ringtones has fostered the use of popular music segments as ringtones, which has reached commercial success by companies providing downloadable music ringtones at a price.
Many mobile phones also support a vibrating alert which may be used in conjunction with a ringtone to alert a user to an incoming call or text message. The vibrating alert may also be turned off or used without an accompanying ringtone. The vibrating alert feature is useful in noisy environments where a ringtone may not be clearly audible, in locations where a ringtone might be disturbing to an event underway, such as in a church or at a movie or play, to alert a user engaged in a conference, and for use by people with hearing impairments. In order to provide a vibration level of sufficient intensity to be recognized, even while the portable device is not visible, many mobile devices engage an embedded motor with an eccentric weight to cause the vibration.
Due to the proliferation of portable devices today and their increased usage, ringtones can become irritating to deal with in a wide variety of contexts, such as, business or family gatherings, by way of example.

Method of associating groups of classified source addresses with vibration patterns


Disclosed is a transparency comprised of a supporting substrate, and thereover and thereunder two coatings, a first heat dissipating antistatic coating layer in contact with the substrate, and wherein the first coating contains a heat dissipating binder optionally with a melting point, for example, in the range of from about 100 to about 260.degree. C., and an antistatic compound and a second ink receiving coating layer thereover containing a blend of a binder polymer, an alkylated oxazoline, a lightfastness compound, and an optional biocide.

The present invention is directed to transparencies, and more specifically, to high projection efficiency, low haze, lightfast and waterfast ink jet transparencies with improved ink absorption and acceptable ink spreading when used in combination with liquid ink compositions and solid ink hot melt ink compositions, such as those selected for thermal ink jet printing processes, and acoustic ink jet printing processes, reference for example copending application U.S. Ser. No. 09/118,573, the disclosure of which is totally incorporated herein by reference. In embodiments of the present invention, the transparencies are comprised of a supporting substrate, such as MYLAR.TM., thereover two coatings, a first antistatic heat resistant coating layer which comprises a binder with a melting point of, for example, in the range of from about 100.degree. C. to about 300.degree. C. and preferably from about 150.degree. C. to 260.degree. C., and, for example, a quaternary compound, and a second light resistant, humidity resistant ink receiving coating layer situated so that the first coating layer is between the second light resistant, humidity resistant ink receiving coating layer and the substrate, the second coating layer being comprised of, for example, a polymer such as poly(2-ethyl-2-oxazoline); 1-[N-[poly(3-allyloxy-2-hydroxy propyl)]-2-imidazolidinone], poly(1-vinylpyrrolidone)-graft-(1-triacontene), or poly(1-vinylpyrrolidone)-graft-(1-hexadecene), a lightfast UV compound such as (2,4-dichloro-6-morpholino-1,3,5-triazine), and copolymers thereof of poly[N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexane diamine-co-2,4-dichloro-6-morpholino-1,3,5-triazine), and mixtures thereof, a biocide and an ink spreading compound selected, for example, from the group consisting of mono and dialkylated oxazolines, wherein the alkyl chain length varies between about 2 to about 30 carbons (about includes all values in between throughout) and the melting point of these oxazolines is, for example, between about 40.degree. C. to about 80.degree. C. and preferably wherein the two coatings, thus a total of four coatings, are present on each surface of the supporting substrate. These transparencies, for example, enable lightfast transparent colored images when printed with inks comprised, for example, of a vehicle such as mono and di alkylated oxazolines, a colorant, such as an alkylated colorant, like mono, di, tri and tetra alkylated dyes and an alkylated antioxidant, such as didodecyl-3,3'-thiodipropionate.
With the transparencies of the present invention, there are enabled a number of advantages, including the important advantages of high projection efficiency primarily because of improved flow of the oxazoline inks on the ink receiving layer containing low surface energy oxazoline compounds, and more specifically, in view of the low surface tension, for example about 30 to about 35 dynes/centimeter, of the ink receiving layer. Also, with the transparencies of the present invention, there are enabled a number of other advantages, including the important advantage of heat resistant characteristics for the transparencies when used in ink jet printers that employ heat or microwave energy for drying inks, low haze, that is, for example, wherein the transparencies permit greater than about 95 percent of the light to be transmitted therethrough in embodiments, and which transparencies possess excellent lightfast and waterfast characteristics. The transparencies of the present invention can also be selected for ink jet methods and apparatus, which employ aqueous inks.


Stray scattering in a scatterometer is removed by use of a lens and aperture system in conjunction with a beamsplitter. Backscattered light from a mirror being tested is deflected by a beamsplitter and focused by a lens through an aperture onto a detector. The distance from the beamsplitter to the lens is much smaller than the distance from the mirror to the beamsplitter in order to increase the detected signal as compared with detected noise caused by light scattered by the beamsplitter. The scatterometer system disclosed is further refined by use of a cavity dumper which absorbs stray light left after reflection from the mirror being tested. The cavity dumper is a silicon semiconductor on a metal backing which absorbs the light with minimum reflection back along the original incident light path.

1. Field of the Invention
This invention relates to scatterometer systems and in particular to scatterometer systems which eliminate stray light. Further this system relates to scatterometers which in addition to having stray light eliminated are able to dump excess light without heating or other surplus light problems.
2. Description of the Prior Art
Previous systems used for scattering measurements from mirrors had no way of controlling back scattered light from entering the light emission source. The use of retroscatter in a device such as a laser gyro causes a problem of lock-in between the output wave from a laser and the reflected wave back along that path. When the waves lock together in frequency, no rotational information for a laser gyro can be obtained. The lock-in phenomena becomes a serious problem when two oscillators with only slight separation of operating frequencies couple together. In this case, there is a weak coupling mechanism which will cause both of them to oscillate at the same frequency. An example of this is the known fact that when two mechanical clocks have nearly the same frequency, they become weakly coupled acousticly by the sound each makes. The article "The Nonlinear Theory of Electric Oscillations" by Balth van der Pol in Proceedings of the Institute of Radio Engineers, Vol. 22, No. 9, September 1934, first analysed the lock-in phenomena as an effect in triode oscillators. A simplification of this analysis has since been published by Robert Adler in an article titled "A Study of Locking Phenomena in Oscillators" in the "Proceedings of the IRE and Waves in Electrons", Vol. 34, June 1946, page 351.
In the laser gyro, two oscillators are nominally independent with two counter propagating waves. These are weakly coupled by the light of one wave which retroscatters from the mirror and combines at a different phase and frequency with the light of the other counter propagating wave. When the frequencies of the two waves are sufficiently separated, which occurs when the laser gyro is rotating rapidly, the waves will not lock together. A recent paper on this laser gyro lock-in phenomena is "A Positive Scale Factor Correction in the Laser Gyro" by Fred Aronowitz and Wah L. Lim in the "IEEE Journal of Quantum Electronics," Vol. QE-13, No. 5, page 338, May 1977. At low gyro rotation rates, which imply small frequency separations, the waves lock together and no information about rotation rate can be obtained. There are two ways in which one can combat this lock-in phenomena. One is to apply a small mechanical oscillation motion called dither. This helps, but leads to a certain amount of undesirable random drift in the output. The second way to combat the lock-in is to develop lower scatter laser mirrors. To do this, more effective methods of measuring retroscatter are needed.

Stray light eliminator in a scatterometer

The United States of America as represented by the Secretary of the Navy


Systems and methods are provided for receiving a request for an allocation of a task in a cluster comprising a plurality of client nodes, determining a node type for the task, based on mapping the task to a list of categories, wherein at least two of categories in the list of categories overlap in range. The systems and methods further providing for searching for available client nodes based on the node type for the task to select a client node to allocate the task, determining a zone of the selected client node, wherein the zone is mapped to the list of categories, determining a wait algorithm associated with the zone of the selected node, and contacting the selected client node and passing the task and the wait algorithm to the selected client node.

Scaling existing systems and solutions to the ever growing requirements and needs of its customers is a problem faced by cloud systems and networks. With the spike in the amount of data, comprising of master data of the customers, generation of purchase orders, requisition objects, legal documents, approval trail, and so forth, the demand on the system resources has increased extensively. As the business and demands of the customers have increased, so has the revenue, and so have the resources deployed to serve the customers. However, since the system is a multi-tenant shared system, where resources and computing power are shared between different tenants, checks are put in place to ensure that the request sizes are throttled and a malicious user or program does not have an impact on others.
While such throttling of resources is an essential requirement to keep the system running properly during sudden spikes of data requests or during malicious requests by an attacker or abnormal system, throttling has an impact on the actual business requirement of the data required to complete a business process. Assume a business application programming interface (API) is throttled to return only the latest 500 data elements even though the request might have been made for data for the last six months comprising of 8000 objects. In such a scenario, throttling of resources acts in a counterproductive manner to the business needs. Moreover, this necessitates an addition of more complexity in the software system by setting up offline and batch systems to retrieve such data. The addition of such processes and offline batch systems only adds to the complexity and unnecessary duplication of multiple end points for the same resources to the ever growing space of customer integrations in enterprise software systems.

Scaling computing resources in a cluster


A medication injecting apparatus has a cartridge housing and a drive housing that is threadedly connected to the cartridge housing for axial displacement relative to one another. The drive housing has a helical-shaped passage and a flexible drive member is slidingly disposed within the helical-shaped passage and extends axially outwardly therefrom toward the cartridge housing. The flexible drive member is movable in the axial direction relative to the drive housing during dose setting and is axially fixed relative to the drive housing during injecting. A clutch has an engaged position and a disengaged position. The flexible drive member is axially fixed relative to the drive housing when the clutch is in the engaged position and the flexible drive member is movable relative to the drive housing when the clutch is in the disengaged position.

Medication dispensing devices in the form of injector pens are known. One such injector pen construction is described in U.S. Pat. No. 7,291,132, which is incorporated herein in its entirety by reference. While the injector pens heretofore fulfill their respective, particular objectives and requirements, they do have drawbacks. For instance, the devices heretofore have complex constructions that are bulky and difficult to operate. As such there exists and need for an injector pen having a compact construction that is easy to operate.


A system, for inhibiting ice formation on a vehicle surface, and de-icing if determined needed to remove any frozen matter formed on the surface, including an anti-icing reservoir, a fluid-selecting control valve, and code that causes a processor to perform operations including determining whether the vehicle is parked, initiating, if parked, activation of, or obtaining of readouts from, any local sensors or routines to be used to determine whether a condition triggering initiation of an anti-freezing cycle is present. The operations include commencing, if triggered, an anti-icing cycle, including initiating changing of the fluid-selection valve to select the anti-freezing reservoir, and initiating pumping of the anti-icing fluid from the anti-icing reservoir to and through a fluid-dispensing nozzle, and onto the surface for inhibiting bonding of frozen material on the surface and/or remove any already formed frozen material on the surface.

Users of conventional vehicles left outdoors during inclement freezing weather often come out windows and mirrors covered in ice or snow. The user has two primary options at that point. They can begin manually scraping the windows and mirrors. They can also start the vehicle and the window-defrost system of the vehicle.
Scraping windows and mirrors has shortcomings including usually requiring arduous labor on the part of the user. Scrapping off ice or snow also is time consuming and requires the user to stand outside in the cold. There is also a risk of scratching the vehicle.
Using the defrost system is time consuming as well. The defrost system also uses a relatively-high amount of energy, both in terms of fuel required to idle the engine and the electric energy used to operate the defrost system.
And with most modern vehicles not having defrost systems for its mirrors, sunroof, side windows, and lamp covers, manual scraping would still be required for those surfaces.
Improved systems and methods to avoid these challenges are needed. The technology of the present disclosure solves these and other shortcomings of conventional systems.

Vehicle anti-icing and de-icing systems and corresponding methods of operation


A mechanically operating pulse for generating electrical pulses dependent upon the rotation of direction of rotary shaft. The pulse generator includes a gear rim having internal toothing driven by the rotary shaft, a radially and generally deflectable switching sleeve which has a cam which engages in a tooth space of the gear rim. A spring member supports the switching sleeve on its side opposite the cam. Metal contacts are disposed adjacent to end areas of the spring member in such a way that said end areas are movable into contact with the metal contacts. A contact stud is disposed centrally of the spring member such that it mechanically retentions it in such a way that each end area is pressed against its adjacent metal contact and the cam is pressed into a tooth space of the gear rim. When the rotary shaft is rotated by one tooth, an end area of the spring member is moved into or out of contact with its adjacent member.

A mechanically operating pulse generator for producing electrical pulses depending on direction of rotation is described in EP-A 229 306. It has a contact tongue movable between a pair of metal contacts for each direction of rotation. Depending on the direction of rotation, either one or the other contact tongue is actuated by a switching sleeve whose cam engages in a gear wheel. The gear wheel is toothed on the outside, and is moved and pressed into the inter-tooth recesses of the gear wheel when the gear wheel rotates.
Manufacturing of this device is, however, too complex. Thus the problem underlying the invention, and a task to be performed, is to devise a mechanically operating pulse transmitter for producing electrical pulses which is as simple as possible in construction -- i.e., which is composed and manufacturable in as simple a manner as possible. Also, the device should be compact and hence space-saving in construction and be suitable for automatic mass production.

Mechanically operating electrical pulse generator


A level shifter applied to a driving circuit of a display is disclosed. The level shifter at least includes a first stage of level shifting unit, a second stage of level shifting unit, and two third stage of level shifting units belonging to different power domains and used to perform boost conversion of voltage signals in different power domains. The first stage of level shifting unit includes eight transistors. The second stage of level shifting unit includes four transistors. The two third stage of level shifting units both include six transistors and two output terminals. The level shifter of the driving circuit in this invention makes the output terminals of the two third stage of level shifting units belonging to different power domains to synchronously output the voltage-shifted voltage signals.

Field of the Invention
This invention relates to a driving circuit of a display, especially to a level shifter applied to a driving circuit of a display.
Description of the Related Art
In general, the driving circuit of the display performs multi-power domain boost on input voltage signals through level shifters. Please refer to FIG. 1 and FIG. 2. FIG. 1 illustrates a schematic diagram of the level shifter of the conventional driving circuit; FIG. 2 illustrates a detailed circuit diagram of the level shifter of FIG. 1.
As shown in FIG. 1, the conventional level shifter 7 can include a first stage of level shifting unit 71 and two second stage of level shifting units 72 and 73. The first stage of level shifting unit 71 is coupled between the ground voltage AGND/half-operating voltage hAVDD and the first middle voltage VCL1; the second stage of level shifting unit 72 is coupled between the half-operating voltage hAVDD and the operating voltage AVDD; the second stage of level shifting unit 73 is coupled between the ground voltage AGND and the half-operating voltage hAVDD; the first stage of level shifting unit 71 is coupled to the second stage of level shifting unit 72.
As shown in FIG. 2, the first stage of level shifting unit 71 includes a first transistor M1, a second transistor M2 . . . and a twelfth transistor M12. The first transistor M1, the second transistor M2, the third transistor M3, the fourth transistor M4, the ninth transistor M9, and tenth transistor M10 are N-type MOSFETs; the fifth transistor M5, the sixth transistor M6, the seventh transistor M7, the eighth transistor M8, the eleventh transistor M11, and twelfth transistor M12 are P-type MOSFETs.
The second stage of level shifting unit 72 includes a thirteenth transistor M13, a fourteenth transistor M14 . . . and an eighteenth transistor M18. The thirteenth transistor M13 and the fourteenth transistor M14 are N-type MOSFETs; the fifteenth transistor M15, the sixteenth transistor M16, the seventeenth transistor M17, and the eighteenth transistor M18 are P-type MOSFETs.
The second stage of level shifting unit 73 includes a nineteenth transistor M19, a twentieth transistor M20 . . . and a twenty-fourth transistor M24. The nineteenth transistor M19 and the twentieth transistor M20 are N-type MOSFETs; the twenty-first transistor M21, the twenty-second transistor M22, the twenty-third transistor M23, and the twenty-fourth transistor M24 are P-type MOSFETs.
Input terminals IN and INB of the first stage of level shifting unit 71 have an input voltage range between 0V and 1.5V; output terminals OUTP and OUTPB of the second stage of level shifting unit 72 have an output voltage range between 5V and 10V; output terminals OUTN and OUTNB of the third stage of level shifting unit 73 have an output voltage range between 0V and 5V; the ground voltage AGND is 0V; the operating voltage AVDD is 10V; the half-operating voltage hAVDD is 5V; the first middle voltage VCL1 is 6.5V; the second middle voltage VCL2 is 3.5V.
At first, it is assumed that the input voltages received by the input terminals IN and INB of the first stage of level shifting unit 71 are 0V and 1.5V respectively; the voltage level of the node A is the first middle voltage VCL1; the voltage level of the node B is the half-operating voltage hAVDD; the voltage level of the node C is (the second middle voltage VCL2 plus the threshold voltage VT); the voltage level of the node D is the first middle voltage VCL1; voltage levels of the two output terminals OUTP and OUTPB of the second stage of level shifting unit 72 are the half-operating voltage hAVDD and the operating voltage AVDD respectively; voltage levels of the two output terminals OUTN and OUTNB of the second stage of level shifting unit 73 are the ground voltage AGND and the half-operating voltage hAVDD respectively.
After the input voltage signal is converted and the input voltage received by the input terminal IN becomes 1.5V and the input voltage received by the input terminal INB becomes 0V, the voltage level of the node D is under a signal fighting and lowered from the original first middle voltage VCL1 to (the first middle voltage VCL1 minus the threshold voltage VT), and at last further lowered to (the second middle voltage VCL2 plus the threshold voltage VT), so that the eleventh transistor M11 is switched on and the node B is charged from the half-operating voltage hAVDD to the first middle voltage VCL1. Afterward, the eighth transistor M8 is switched on and the node C is charged from (the second middle voltage VCL2 plus the threshold voltage VT) to (the half-operating voltage hAVDD plus the threshold voltage VT), and at last further charged to the first middle voltage VCL1, so that the tenth transistor M10 is switched on and the node A is discharged from the first middle voltage VCL1 to the half-operating voltage hAVDD. The node A and the node B output the voltage signals V2 and V1 to the second stage of level shifting unit 72 respectively to be converted to another power domain.
It should be noticed that the node C cannot be charged until the voltage level of the node D is lowered to (the first middle voltage VCL1 minus the threshold voltage VT); therefore, there will be a time difference between the signal conversion time of the node C and the signal conversion time of the node D; that is to say, the signal conversion times of the node C and the node D cannot be synchronous; therefore, the signal conversion times of the node A and the node B cannot be synchronous with the signal conversion times of the two output terminals OUTP and OUTPB of the second stage of level shifting unit 72.
On the other hand, compared to the output voltage signals of the two output terminals OUTP and OUTPB of the second stage of level shifting unit 72 being boosted by two stages of level shifting circuit to reach the target voltage range of the power domain of the second stage of level shifting unit 72, the output voltage signals of the two output terminals OUTN and OUTNB of the second stage of level shifting unit 73 only needs to be boosted by one stage of level shifting circuit to reach the target voltage range of the power domain of the second stage of level shifting unit 73. Therefore, the signal conversion output time needed by the two output terminals OUTN and OUTNB of the second stage of level shifting unit 73 will be shorter than that needed by the two output terminals OUTP and OUTPB of the second stage of level shifting unit 72. In other words, the signal conversion output time of the two output terminals OUTN and OUTNB of the second stage of level shifting unit 73 is not synchronous with that of the two output terminals OUTP and OUTPB of the second stage of level shifting unit 72.
Above all, it can be found that in the level shifter 7 of the conventional driving circuit, the signal conversion times of the output terminals OUTP, OUTPB, OUTN, and OUTNB of the second stage of level shifting units 72 and 73 fail to be synchronous; therefore, the multi-power domain signal level-shifting efficiency and the performance of the driving circuit of the display will be seriously affected accordingly.