Methods of treating or preventing neuronal loss associated with stroke, ischemia, CNS trauma, hypoglycemia and surgery, as well as treating neurodegenerative diseases including Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease and Down's syndrome, treating or preventing the adverse consequences of the hyperactivity of the excitatory amino acids, as well as treating anxiety, chronic pain, convulsions, inducing anesthesia and treating psychosis are disclosed by administering to an animal in need of such treatment a compound having high affinity for the glycine binding site, lacking PCP side effects and which crosses the blood brain barrier of the animal.. Also disclosed are novel 1,4-dihydroquinoxaline-2,3-diones, and pharmaceutical compositions thereof. Also disclosed are highly soluble ammonium salts of 1,4-dihydroquinoxaline-2,3-diones.

Glutamate is thought to be the major excitatory neurotransmitter in the brain. There are three major subtypes of glutamate receptors in the CNS. These are commonly referred to as kainate, AMPA and N-methyl-D-aspartate (NMDA) receptors (Watkins and Olverman, Trends in Neurosci. 7: 265-272 (1987)). NMDA receptors are found in the membranes of virtually every neuron in the brain. NMDA receptors are ligand-gated cation channels that allow Na.sup.+, K.sup.+ and Ca.sup.++ to permeate when they are activated by glutamate or aspartate (non-selective, endogenous agonists) or by NMDA (a selective, synthetic agonist) (Wong and Kemp, Ann. Rev. Pharmacol. Toxicol. 31: 401-425 (1991)).
Glummate alone cannot activate the NMDA receptor. In order to become activated by glutamate, the NMDA receptor channel must first bind glycine at a specific, high affinity glycine binding site which is separate from the glummate/NMDA binding site on the receptor protein (Johnson and Ascher, Nature 325: 329-331 (1987)). Glycine is therefore an obligatory coagonist at the NMDA receptor/channel complex (Kemp, J. A., et al., Proc. Natl. Acad. Sci. USA 85: 6547-6550 (1988)).
Besides the binding sites for glutamate/NMDA and glycine, the NMDA receptor carries a number of other functionally important binding sites. These include binding sites for Mg.sup.++, Zn.sup.++, polyamines, arachidonic acid and phencyclidine (PCP) (Reynolds and Miller, Adv. in Pharmacol. 21: 101-126 (1990); Miller, B., et al., Nature 355: 722-725 (1992)). The PCP binding site--now commonly referred to as the PCP receptor--is located inside the pore of the ionophore of the NMDA receptor/channel complex (Wong, E. H. F., et al., Proc. Natl. Acad. Sci. USA 83: 7104-7108 (1986); Huettner and Bean, Proc. Natl. Acad. Sci. USA 85: 1307-1311 (1988); MacDonald, J. F., et al., Neurophysiol. 58: 251-266 (1987)). In order for PCP to gain access to the PCP receptor, the channel must first be opened by glutamate and glycine. In the absence of glutamate and glycine, PCP cannot bind to the PCP receptor although some studies have suggested that a small amount of PCP binding can occur even in the absence of glummate and glycine (Sircar and Zukin, Brain Res. 556: 280-284 (1991)). Once PCP binds to the PCP receptor, it blocks ion flux through the open channel. Therefore, PCP is an open channel blocker and a non-competitive glutamate antagonist at the NMDA receptor/channel complex.
One of the most potent and selective drugs that bind to the PCP receptor is the anticonvulsant drug MK801. This drug has a K.sub.d of approximately 3 nM at the PCP receptor (Wong, E. H. F., et al., Proc. Natl. Acad. Sd. USA 83: 7104-7108 (1986)).
Both PCP and MK801 as well as other PCP receptor ligands [e.g. dextromethorphan, ketamine and N,N'-disubstituted guanidines] have neuroprotective efficacy both in vitro and in vivo (Gill, R., et al., J. Neurosci. 7: 3343-3349 (1987); Keana, J. F. W., et al., Proc. Natl. Acad. Sci. USA 86: 5631-5635 (1989); Steinberg, G. K., et al., Neuroscience Lett. 89: 193-197 (1988); Church, J., et al., In: Sigma and Phencyclidine-Like Compounds as Molecular Probes in Biology, Domino and Kamenka, eds., Ann Arbor: NPP Books, pp. 747-756 (1988)). The well-characterized neuroprotective efficacy of these drugs is largely due to their capacity to block excessive Ca.sup.++ influx into neurons through NMDA receptor channels which become over activated by excessive glutamate release in conditions of brain ischemia (e.g. in stroke, cardiac arrest ischemia etc.) (Collins, R. C., Metabol. Br. Dis. 1: 231-240 (1986); Collins, R. C., et al., Annals Int. Med. 110: 992-1000 (1989)).
However, the therapeutic potential of these PCP receptor drugs as ischemia rescue agents in stroke has been severely hampered by the fact that these drugs have strong PCP-like behavioral side effects (psychotomimetic behavioral effects) which appear to be due to the interaction of these drugs with the PCP receptor (Tricklebank, M. D., et al., Eur. J. Pharmacol. 167: 127-135 (1989); Koek, W., et al., J. Pharmacol. Exp. Ther. 245: 969 (1989); Willets and Balster, Neuropharmacology 27: 1249 (1988)). These PCP-like behavioral side effects appear to have caused the withdrawal of MK801 from clinical development as an ischemia rescue agent. Furthermore, these PCP receptor ligands appear to have considerable abuse potential as demonstrated by the abuse liability of PCP itself.
The PCP-like behavioral effects of the PCP receptor ligands can be demonstrated in animal models: PCP and related PCP receptor ligands cause a behavioral excitation (hyperlocomotion) in rodents (Tricklebank, M. D., et al., Eur. J. Pharmacol. 167: 127-135 (1989)) and a characteristic katalepsy in pigeons (Koek, W., et al., J. Pharmacol. Exp. Ther. 245: 969 (1989); Willets and Balster, Neuropharmacology 27: 1249 (1988)); in drug discrimination paradigms, there is a strong correlation between the PCP receptor affinity of these drugs and their potency to induce a PCP-appropriate response behavior (Zukin, S. R., et al., Brain Res. 294: 174 (1984); Brady, K. T., et al., Science 215: 178 (1982); Tricklebank, M. D., et al., Eur. J. Pharmacol. 141: 497 (1987)).
Drugs acting as competitive antagonists at the glutamate binding site of the NMDA receptor such as CGS 19755 and LY274614 also have neuroprotective efficacy because these drugs--like the PCP receptor ligands--can prevent excessive Ca.sup.++ flux through NMDA receptor/channels in ischemia (Boast, C. A., et al., Brain Res. 442: 345-348 (1988); Schoepp, D. D., et al., J. Neural. Trans. 85: 131-143 (1991)). However, competitive NMDA receptor antagonists also have PCP-like behavioral side-effects in animal models (behavioral excitation, activity in PCP drug discrimination tests) although not as potently as MK801 and PCP (Tricklebank, M. D., et al., Eur. J. Pharmacol. 167: 127-135 (1989)).
An alternate way of inhibiting NMDA receptor channel activation is by using antagonists at the glycine binding site of the NMDA receptor. Since glycine must bind to the glycine site in order for glutamate to effect channel opening (Johnson and Ascher, Nature 325: 329-331 (1987); Kemp, J. A., et al., Proc. Natl. Acad. Sci. USA 85: 6547-6550 (1988)), a glycine antagonist can completely prevent ion flux through the NMDA receptor channel--even in the presence of a large amount of glutamate.
Recent in vivo microdialysis studies have demonstrated that in the rat focal ischemia model, there is a large increase in glutamate release in the ischemic brain region with no significant increase in glycine release (Globus, M. Y. T., et al., J. Neurochem. 57: 470-478 (1991)). Thus, theoretically, glycine antagonists should be very powerful neuroprotective agents, because they can prevent the opening of NMDA channels by glutamate non-competitively and therefore--unlike competitive NMDA antagonists--do not have to overcome the large concentrations of endogenous glutamate that are released in the ischemic brain region.
Furthermore, because glycine antagonists act at neither the glutamate/NMDA nor the PCP binding sites to prevent NMDA channel opening, these drugs might not cause the PCP-like behavioral side effect seen with both PCP receptor ligands and competitive NMDA receptor antagonists (Tricklebank, M. D., et al., Eur. J. Pharmacol. 167: 127-135 (1989); Koek, W., et al., J. Pharmacol. Exp. Ther. 245: 969 (1989); Willets and Balster, Neuropharmacology 27: 1249 (1988); Tricklebank, M. D., et al., Eur. J. Pharmacol. 167: 127-135 (1989); Zukin, S. R., et al., Brain Res. 294: 174 (1984); Brady, K. T., et al., Science 215: 178 (1982); Tricklebank, M. D., et al., Eur. J. Pharmacol. 141: 497 (1987)). That glycine antagonists may indeed be devoid of PCP-like behavioral side effects has been suggested by recent studies in which available glycine antagonists were injected directly into the brains of rodents without resulting in PCP-like behaviors (Tricklebank, M. D., et al., Eur. J. Pharmacol. 167: 127-135 (1989)). However, there have been two major problems which have prevented the development of glycine antagonists as clinically useful neuroprotective agents:
A. Most available glycine antagonists with relatively high receptor binding affinity in vitro such as 7-Cl-kynurenic acid (Kemp, J. A., et al., Proc. Natl. Acad. Sci. USA 85: 6547-6550 (1988)), 5,7-dichlorokynurenic acid (McNamara, D., et al., Neuroscience Lett. 120: 17-20 (1990)) and indole-2-carboxylic acid (Gray, N. M., et al., J. Med. Chem. 34: 1283-1292 (1991)) cannot penetrate the blood/brain barrier and therefore have no utility as therapeutic agents; PA1 B. The only available glycine antagonist that sufficiently penetrates the blood/brain barrier-the drug HA-966 (Fletcher and Lodge, Eur. J. Pharmacol. 151: 161-162 (1988))--is a partial agonist with only micromolar affinity for the glycine binding site. A neuroprotective efficacy for HA-966 in vivo has therefore not been demonstrated nor has it been demonstrated for the other available glycine antagonists because they lack bioavailability in vivo. PA1 R.sup.6 and R.sup.7 independently are NO.sub.2, halogen, CN, CF.sub.3, or OR', wherein R' is C.sub.1-4 -alkyl, and R.sup.5 and R.sup.8 are each hydrogen; or PA1 R.sup.5 and R.sup.6 together form a further fused aromatic ring, which may be substituted with halogen, NO.sub.2, CN, CF.sub.3 or OR', wherein R' is C.sub.1-4 -alkyl; or PA1 R.sup.7 and R.sup.8 together form a further fused aromatic ring, which may be substituted with halogen, NO.sub.2, CN, CF.sub.3 or OR', wherein R' is C.sub.1-4 -alkyl, and R.sup.5 and R.sup.6 independently are hydrogen, halogen, CN, CF.sub.3, NO.sub.2 or OR', wherein R' is C.sub.1-4 -alkyl. These compounds are reportedly useful for the treatment of indications caused by hyperactivity of the excitatory neurotransmitters, particularly the quisqualate receptors, and as neuroleptics. PA1 lack the PCP-like behavioral side effects common to the PCP-like NMDA channel blockers such as MK801 or to the competitive NMDA receptor antagonists such as CGS19755; PA1 show potent anti-ischemic efficacy because of the non-competitive nature of their glutamate antagonism at the NMDA receptor; PA1 cross the blood-brain barrier at levels sufficient for efficacy; PA1 have utility as novel anticonvulsants with less side-effects than the PCP-like NMDA channel blockers or the competitive NMDA antagonists; PA1 help in defining the functional significance of the glycine binding site of the NMDA receptor in vivo. PA1 R is hydrogen, hydroxy, amino, --CH.sub.2 CONHAr, --NHCONHAr, --NHCOCH.sub.2 Ar, --COCH.sub.2 Ar, wherein Ar is an aryl group, or a radical having the formula: ##STR12## wherein R.sup.6 is hydrogen, lower C.sub.1-6 alkyl or aryl; PA1 R.sup.7 is hydrogen or lower C.sub.1-6 alkyl; PA1 n is an integer from 0 to 5; and PA1 R.sup.8 is hydrogen, C.sub.1-6 alkyl or aralkyl; PA1 R.sup.1 is hydrogen, amino, acylamino, halo, haloalkyl or nitro; PA1 R.sup.2 is hydrogen, amino, acylamino, nitro, halo or haloalkyl; PA1 R.sup.3 is hydrogen, amino, acylamino, halo or haloalkyl; and PA1 R.sup.4 is hydrogen, amino, acylamino, halo, haloalkyl or nitro. PA1 R .sup.2 is hydrogen, acylamino, nitro, amino, haloalkyl or halo; PA1 R.sup.3 is hydrogen, acylamino, halo, amino or haloalkyl; and PA1 R.sup.4 is hydrogen, acylamino, halo, amino, haloalkyl or nitro. PA1 R is hydrogen; PA1 R.sup.1 is hydrogen, acylamino, halo, haloalkyl or nitro; PA1 R.sup.2 is acylamino, hydrogen, nitro, haloalkyl or halo; PA1 R.sup.3 is hydrogen, acylamino, halo or haloalkyl; and PA1 R.sup.4 is acylamino, hydrogen, halo, haloalkyl or nitro; with hydroxylamine-O-sulfonic acid under basic conditions to give the corresponding N-amino-1,4-dihydroquinoxaline-2,3-dione.
There have been a number of reports in the literature of substituted 1,4-dihydroquinoxaline-2,3-diones which are useful for treating pathophysiologic conditions mediated by the, non-NMDA, NMDA and glycine receptors. For example, U.S. Pat. No. 4,975,430 (1990), discloses 1,4-dihydroquinoxaline-2,3-dione compounds of the formula: ##STR1## wherein each X is independently nitro or cyano and wherein each Y is independently H, lower alkyl, lower alkoxy, or CF.sub.3. These compounds are reportedly useful for the treatment of neuronal conditions associated with stimulation of the NMDA receptor.
U.S. Pat. No. 3,962,440 (1976), discloses 1,4-dihydroquinoxaline-2,3-dione compounds having the formula: ##STR2## wherein, R.sup.1 may be hydrogen or methyl, R.sub.m may be loweralkyl, loweralkoxy, loweralkylthio, cyclopropyl, nitro, cyano, halogen, fluoroalkyl of C.sub.1 -C.sub.2 (trifluoromethyl) amino or substituted amino, and n may be 0, 1 or 2. These compounds are reportedly useful as hypnotic agents.
U.S. Pat. No. 4,812,458 (1989), discloses 1,4-dihydroquinoxaline-2,3-dione compounds having the formula: ##STR3## wherein R.sup.1 is halogen, cyano, trifluoromethyl, ethynyl or N.sub.3 and R.sup.2 is SO.sub.2 C.sub.1-3 -alkyl, trifluoromethyl, nitro, ethynyl or cyano. These compounds are reportedly useful for treatment of indications caused by hyperactivity of the excitatory neurotransmitters, particularly the quisqualate receptors, and as neuroleptics.
U.S. Pat. No. 4,659,713 (1987), discloses 1,4-dihydroquinoxaline-2,3-dione compounds having the formula: ##STR4## wherein X represents hydrogen, chloro, bromo, fluoro, iodo, trichloromethyl, dichlorofluoromethyl, difluoromethyl or trifluoromethyl, and n represents 1 or 2. These compounds are reportedly useful for the control of coccidiosis in animals.
U.S. Pat. No. 4,948,794 (1990), discloses 1,4-dihydroquinoxaline-2,3-dione compounds having the formula: ##STR5## wherein R.sup.1 is C.sub.1-12 -alkyl, which may optionally be substituted by hydroxy, formyl, carboxy, carboxylic esters, amides or amines, C.sub.3-8 -cycloalkyl, aryl, aralkyl; and wherein R.sup.6 is, hydrogen, halogen, CN, CF.sub.3, NO.sub.2, or OR', wherein R' is C.sub.1-4 -alkyl and R.sup.5, R.sup.7 and R.sup.8 is hydrogen, provided R.sup.6 is not CF.sub.3, OCH.sub.3, NO.sub.2, C.sup.1 or Br when R.sup.1 is CH.sub.3 ; or
Yoneda and Ogita, Biochem. Biophys. Res. Commun. 164: 841-849 (1989), disclose that the following 1,4-dihydroquinoxaline-l,2-diones competitively displaced the strychnine-insensitive binding of [.sup.3 H]glycine, without affecting the other binding sites on the NMDA receptor complex:
______________________________________ R.sub.1 R.sub.2 ______________________________________ ##STR6## H Cl Cl NO.sub.2 NO.sub.2 H H Cl CN NO.sub.2 QX CQX DCQX CNQX DNQX ______________________________________
According to the authors, the structure-activity relationships among quinoxalines clearly indicates that both chloride groups of the positions 6 and 7 in the benzene ring are crucial for the antagonist potency against the Gly sites. Removal of one chloride from the molecule results in a 10-fold reduction in the affinity for Gly sites.
Kleckner and Dingledine, Mol. Pharm. 36: 430-436 (1989), disclose that 6,7-dinitro-1,4-dihydroquinoxaline-2,3-dione and 6-cyano-7-nitro-1,4-dihydroquinoxaline-2,3-dione are more potent antagonists of kainate than glycine, but substitution of Cl at the 6-position and especially at the 6- and 7-positions increases potency at the glycine site. In addition, the authors suggest that antagonists of the glycine site might be effective against NMDA receptor-mediated neuropathologies.
Rao, T. S. et al., Neuropharmacology 29: 1031-1035 (1990), disclose that 6,7-dinitro-1,4-dihydroquinoxaline-2,3-dione and 7-cyano-6-nitro-1,4-dihydroquinoxaline-2,3-dione antagonize responses mediated by NMDA-associated glycine recognition sites in vivo.
Pellegrini-Giampietro, D. E. et al., Br. J. Pharmacol. 98: 1281-1286 (1989), disclose that 6-cyano-7-nitro-1,4-dihydroquinoxaline-2,3-dione and 6,7-dinitro-1,4-dihydroquinoxaline-2,3-dione may antagonize the responses to L-glutamate by interacting with the glycine recognition sites of the NMDA receptor ion channel complex.
Ogita and Yoneda, J. Neurochem. 54: 699-702 (1990), disclose that 6,7-dichloro-1,4-dihydroquinoxaline-2,3-dione is a competitive antagonist specific to the strychnine-insensitive [.sup.3 H] glycine binding sites on the NMDA receptor complex. According to the authors, the two chloride radicals at the 6- and 7-positions in the benzene ring of the quinoxaline are crucial for the antagonistic potency against the glycine binding sites.
Kessler, M. et al., Brain Res. 489: 377-382 (1989), disclose that 6,7-dinitro-1,4-dihydroquinoxaline-2,3-dione and 6-cyano-7-nitro-1,4-dihydroquinoxaline-2,3-dione inhibit [.sup.3 H] glycine binding to the strychnine-insensitive glycine binding sites associated with NMDA receptors.
European Patent Application Publication No. 0 377 112, published Jul. 11, 1990, discloses 1,4-dihydroquinoxaline-2,3-dione compounds having the formula: ##STR7## wherein, inter alia, R.sup.1 may be hydroxy, alkoxy, aryloxy, aralkyloxy, cycloalkylalkoxy, cycloalkoxy or acyloxy; and R.sup.5, R.sup.6, R.sup.7 and R.sup.8 may be independently hydrogen, nitro, halogen, cyano, trifluoromethyl, SO.sub.2 NR'R', SO.sub.2 R' or OR', wherein R' is hydrogen or C.sub.1-4 alkyl. These compounds are reportedly useful for the treatment of indications caused by hyperactivity of the excitatory neurotransmitters, particularly the quisqualate receptors, and as neuroleptics.
Lester, R. A. et al., Mol. Pharm. 35: 565-570 (1989), disclose that 6-cyano-7-nitro-1,4-dihydroquinoxaline-2,3-dione antagonizes NMDA receptor-mediated responses, by a competitive interaction of the glycine binding site.
Patel, J. et al., J. Neurochem. 55: 114-121 (1990), disclose that the neuroprotective activity of 6,7-dinitro-1,4-dihydroquinoxaline-2,3-dione is due to antagonism of the coagonist activity of glycine at the NMDA receptor-channel complex.
Horner, L. et al., Chem. Abstracts 48: 2692 (1953) disclose 6,8-dinitro-1,4-dihydroquinoxaline-2,3-dione.
Cheeseman, G. W. H., J. Chem. Soc.: 1170-1176 (1962), discloses 6,7-dibromo-2,3-dihydroxyquinoxaline (also known as 6,7-dibromo-1,4-dihydroquinoxaline-2,3-dione).
Honore, T. et al., Science 241: 701-703 (1988), disclose that 6,7-dinitro-1,4-dihydroquinoxaline-2,3-dione and 7-cyano-6-nitro-1,4-dihydroquinoxaline-2,3-dione are potent non-NMDA glutamate receptor antagonists.
Sheardown, M. J. et al., Eur. J. Pharmacol. 174: 197-204 (1989), disclose that 5,7-dinitro-1,4-dihydroquinoxaline-2,3-dione is a potent antagonist of the strychnine insensitive glycine receptor and has anticonvulsant properties. However, Sheardown et al. also disclose that 5,7-dinitro-1,4-dihydroquinoxaline-2,3-dione as well as DNQX and CNQX have poor access to the central nervous system.
International Application Publication No. WO91/13878 discloses the following N-substituted 1,4-dihydroquinoxaline-2,3-diones which bind to the glycine receptor: ##STR8## wherein R represents hydrogen, C.sub.1-6 alkyl or aralkyl and n is an integer from 0 to 5; R.sup.4 represents hydrogen or hydroxy; R.sup.5, R.sup.6, R.sup.7 and R.sup.8 independently represent hydrogen, nitro, halogen, alkoxy, aryloxy, aralkoxy, C.sub.1-6 -alkyl or aryl; R.sup.9 represents hydrogen, lower alkyl, or aryl; R.sup.10 represents hydrogen, or alkyl, and pharmaceutically acceptable salts thereof.
Leeson et al., J. Med. Chem. 34: 1243-1252 (1991), disclose a number of derivatives of the nonselective excitatory amino acid antagonist kynurenic acid. Also disclosed are a number of structurally related quinoxaline-2,3-diones which are also glycine/NMDA antagonists but which are not selective and are far less potent than the kynurenic acid derivatives. The quinoxaline-2,3-diones have the structure: ##STR9## wherein R is H, 5-Cl, 7-Cl, 5,7-Cl.sub.2, 6,7-Cl.sub.2, 6,7-(CH.sub.3).sub.2, 6-NO.sub.2 or 6,7-(NO.sub.2).sub.2. Also disclosed are a number of N-methyl derivatives.
Swartz et al., Mol. Pharmacol. 41: 1130-1141 (1992), disclose that certain substituted and unsubstituted benzazepines are competitive antagonists of glutamate receptor channels in cultured cortical neurons. See also, U.S. Pat. No. 5,254,683, which discloses that compounds of the formula ##STR10## wherein R.sup.1 -R.sup.4 may be hydrogen, C.sub.1-3 perfluoroalkyl, halo, nitro or cyano and R.sup.5 may be hydrogen or a C.sub.1-5 alkyl group, are antagonists of the glycine binding site on the NMDA receptor complex.
A need continues to exist for potent and selective glycine/NMDA antagonists which:

Glycine receptor antagonists and the use thereof

State of Oregon, Acting By and Through The Oregon State Board of Higher Education, Acting For and On Behalf of The Oregon Health Sciences University and The University of Oregon, Eugene Oregon

The Regents of The University of California


A collapsible and expandable children's toy building block is described. The toy blocks may be made in various sizes and shapes. The toy block includes an internal frame. A cover is positioned over the internal frame to form the toy block. The toy block converts from a collapsed position to an expanded position, and the toy block converts from the expanded position back to the collapsed position.

Existing toy blocks for children in include cardboard box blocks. These cardboard box blocks fold to a block shape. However, these cardboard box blocks are not designed to be flattened to a storage position. Once the cardboard box blocks have been folded to the block shape, it is difficult to flatten such cardboard box blocks back to their original flattened shape. As such, the existing cardboard blocks require much storage space when not being played with.
Children have long enjoyed fort building. Children often use pillows, blankets, couch cushions, etc. These items provide limited functionality and design choice. These items are bulky and difficult to clean up and provide minimum educational value.


A multilayer ceramic capacitor including an internal electrode layer, an internal dielectric layer having a thickness of less than 2 μm, and an external dielectric layer is provided, wherein the internal dielectric layer and external dielectric layer contain a plurality of dielectric particles, and when assuming that an average particle diameter of the entire dielectric particles in the internal dielectric layer is D50a (unit: μm), an average particle diameter of the entire dielectric particles existing at a position being away at least by 5 μm from the outermost internal electrode layer in the thickness direction is D50b (unit: μm), a ratio (D50a/D50b) of the D50a and D50b is y (no unit), standard deviation of a particle size distribution of the entire dielectric particles in the internal dielectric layer is σ (no unit), and a ratio that dielectric particles (coarse particles) having an average particle diameter of 2.25 times of the D50a exist in the entire dielectric particles is p (unit: %), the y and x satisfy a relationship of y<−0.75x+2.015 and y>−0.75x+1.740, the σ satisfies σ<0.091 and the p satisfies p<2.85%; by which a TC bias characteristic can be expected to be improved while maintaining various electric characteristics, particularly a sufficient permittivity, even when the internal dielectric layer is made thin.

1. Field of the Invention
The present invention relates to a multilayer ceramic capacitor.
2. Description of the Related Art
A multilayer ceramic capacitor is composed of an element body having the configuration that a plurality of dielectric layers and internal electrode layers are alternately stacked and a pair of external terminal electrodes formed on both end portions of the element body. The multilayer ceramic capacitor is produced by producing a pre-firing element body by alternately stacking pre-firing dielectric layers and pre-firing internal electrode layers exactly by necessary numbers first, then, after firing the same, forming a pair of external terminal electrodes on both end portions of the fired element body.
When producing a multilayer ceramic capacitor, since the pre-firing dielectric layers and the pre-firing internal electrode layers are fired at a time, a conductive material included in the pre-firing internal electrode layers is demanded to have a higher melting point than a sintering temperature of dielectric material powder included in the pre-firing dielectric layers, not to react with the dielectric material powder, and not to be dispersed in the fired dielectric layers, etc.
In recent years, to respond to the demands, as a conductive material included in the pre-firing internal electrode layers, instead of conventionally used Pt, Pd and other precious metals, an Ag—Pd alloy is used, or those using Ni, which can be fired in a reducing atmosphere, and other inexpensive base metals by giving reduction-resistance to the dielectric material have been developed.
The case of using Ni as a conductive material included in the pre-firing internal electrode layers will be explained as an example. Ni has a lower melting point comparing with that of dielectric material powder included in the pre-firing dielectric layer. Therefore, when pre-firing dielectric layers and pre-firing internal electrode layers including Ni as a conductive material are fired at a time, due to a difference of sintering start temperatures of the dielectric material powder and Ni, Ni internal electrode tends to become thick to be eventually broken as sintering of the dielectric material powder proceeds. Thus, to suppress this kind of breaking due to firing and to suppress sintering, there is proposed a technique of adding an additive dielectric material as a sintering retarder to an internal electrode layer paste for forming the internal electrode layers (refer to the patent articles 1 to 5). The additive dielectric material has a property of being dispersed from the internal electrode layer side to the internal dielectric layer side at the time of firing pre-firing internal dielectric layers and pre-firing internal electrode layers at a time.
In recent years, as a result that a variety of electronic apparatuses became compact, a multilayer ceramic capacitor installed inside the electronic apparatuses has been demanded to realize a compact body with a larger capacity, a low price and high reliability. To respond to the demands, a fired internal electrode layer, fired internal dielectric layer arranged between mutually facing fired internal electrode layers have been made thinner. Specifically, a thickness after firing per one fired internal dielectric layer has become as thin as 1 μm or so and, along therewith, a thickness before firing per one pre-firing internal dielectric layer has also become thinner.
As the pre-firing internal dielectric layer becomes thinner, a content of a dielectric material per one dielectric layer for forming it decreases.
For example, the case of preparing an internal electrode layer paste obtained by adding an additive dielectric material at a predetermined weight ratio to Ni as a conductive material and forming by applying the paste to be a predetermined thickness to a plurality of pre-firing internal dielectric layers, wherein the pre-firing thickness is gradually made thinner, will be considered. At this time, the weight ratio of a content of the additive dielectric material in the internal electrode layer with respect to a content of the dielectric material in the pre-firing internal dielectric layer (a content of the additive dielectric material in the internal electrode layer/a content of the dielectric material in the pre-firing internal dielectric layer) gradually increases as the thickness of the pre-firing internal dielectric layer applied with the internal electrode layer paste becomes thinner. It is because a content of the dielectric material in the pre-firing internal dielectric layer decreases as the thickness of the pre-firing internal dielectric layer becomes thinner, so that a denominator of a formula of the above weight ratio becomes smaller, consequently, a value of the weight ratio becomes larger.
When considering this from the pre-firing internal dielectric layer side, it means that the thinner the thickness becomes, the larger an amount of the additive dielectric material to be dispersed from the internal electrode layer side relatively becomes. Namely, a relative dispersal amount from the internal electrode layer side to the internal dielectric layer side increases.
Also, as the pre-firing internal dielectric layer becomes thinner as above, the pre-firing internal electrode layer is also demanded to be thinner, however, to make the pre-firing internal electrode layer thinner, the additive dielectric material as well as a conductive material, such as Ni, in the internal electrode layer paste for forming the same are demanded to be finer.
However, when the additive dielectric material to be dispersed from the internal electrode layer side to the internal dielectric layer side at the time of firing is made finer, grain growth of dielectric particles composing the internal dielectric layer may be accelerated to influence the fine structure of the internal dielectric layer in some cases. As explained above, the influence is furthermore enhanced when the dispersal amount of the additive dielectric material from the internal electrode layer side to the internal dielectric layer side becomes larger. The influence on the fine structure can be ignored when a thickness of the fired internal dielectric layer is made to be 2.0 μm or more, however, the influence on the fine structure tends to become large when the thickness of the fired internal dielectric layer is made thin as less than 2.0 μm. Along with the influence on the fine structure as such, it is liable that various characteristics, such as a bias characteristic and reliability, of a multilayer ceramic capacitor to be obtained are deteriorated.
To solve the disadvantages, the patent article 6 proposes a technique of adjusting an additive composition for an internal electrode layer paste and adjusting a ratio of an average particle diameter of dielectric particles contacting the internal electrode layer after firing and that of not contacting dielectric particles, concentration ratio of additive components and a core-shell ratio. According to the technique described in the patent article 6, a dielectric layer can be made thinner without deteriorating a temperature characteristic, i and lifetime. However, bias characteristics were not sufficiently improved in the technique described in the patent article 6, so that a problem to be solved still remained.
The patent article 7 discloses a multilayer ceramic capacitor wherein an average particle diameter of dielectric particles near an external electrode is the same as or smaller than an average particle diameter of dielectric particles in an effective region.
However, the technique described in the patent article 7 is for a purpose of preventing cracks at the time of sintering the external electrode, and an improvement of the bias characteristics cannot be expected.                Patent Article 1: The Japanese Unexamined Patent Publication No. 5-62855        Patent Article 2: The Japanese Unexamined Patent Publication No. 2000-277369        Patent Article 3: The Japanese Unexamined Patent Publication No. 2001-307939        Patent Article 4: The Japanese Unexamined Patent Publication No. 2003-77761        Patent Article 5: The Japanese Unexamined Patent Publication No. 2003-100544        Patent Article 6: The Japanese Unexamined Patent Publication No. 2003-124049        Patent Article 7: The Japanese Unexamined Patent Publication No. 2003-133164


A printer and method for printing a secure document are disclosed. For example, the printer includes a controller for receiving an indication that a print job contains the secure document, a lock on a printer door, wherein the lock is electrically coupled to the controller, wherein the lock is engaged by the controller after receiving the indication that the print job contains the secure document and the lock is disengaged when the print job is completed successfully and a user interface in communication with the controller for receiving a security code to disengage the lock when print job is interrupted due to an error.

Some documents require a high level of security when being printed. For example, the document may contain personal information, sensitive financial information, highly confidential information, and the like. These documents cannot be printed on traditional printers as anyone can take the printed documents from the paper tray.
Some printers use a secured paper tray. For example, the printed documents are outputted into a locked or secured paper tray that requires an individual with a key to open the paper tray to obtain the printed documents. However, other portions of the printer are not secure. For example, individuals may stop a printing job and access compartments within the printer during a paper jam to obtain some of the secure documents. As a result, even with secured paper trays, some documents may still be accessible.


According to one embodiment, a reticle chuck cleaner for cleaning a reticle chuck of an EUV exposure apparatus includes a substrate having a shape to be carried to the reticle chuck of the EUV exposure apparatus, and an adhesive formed on one of the main surfaces of the substrate.

Recently, extreme ultra-violet (EUV) lithography has come to be used with the miniaturization of semiconductor devices. The wavelength of EUV light is as short as 13.5 nm and the light is instantly attenuated in air. Therefore, it is required to incorporate an exposure optical system in vacuum in a wafer exposure apparatus (EUV scanner) using EUV light. In this case, since a reticle stage itself is placed in vacuum, a vacuum chuck cannot be used for a chucking mechanism of an EUV mask and an electrostatic chucking system is used. In the electrostatic chucking system, a chucking region with a larger area is required to provide the same holding power in comparison with a vacuum chucking system. Therefore, in the EUV mask, it is necessary to use a large portion of the backside surface thereof as a chucking region.
Thus, in the EUV lithography, since a large portion of the backside surface thereof is used as the chucking region, a foreign matter tends to be present on the surface of the chucking mechanism. If a foreign matter is sandwiched between the chucking mechanism and the EUV mask, the EUV mask is deformed and strain occurs on the pattern surface. As a result, there occurs a problem that a pattern transferred onto the wafer is strained. Further, since the chucking mechanism is provided in the large vacuum chamber, it is necessary to set the pressure in the vacuum chamber back to atmospheric pressure and perform a cleaning operation in order to eliminate the foreign matter. In this case, the stop time of the EUV scanner becomes long and mainly causes the operability of the EUV scanner to be lowered.


A mura compensation method for display panel is disclosed, including: compressing on an array basis of n*m pixels, storing a default mura compensation value corresponding to a first pixel in each area; based on the default mura compensation value, performing linear interpolation calculation to obtain mura compensation values for pixels in the same area other than the first pixel, and performing mura compensation to the display panel; after performing mura compensation to the display panel, obtaining information of an X-th area still having mura phenomenon, the X-th area being an area formed by compression on an array basis of n*m pixels of the display panel; obtaining a final grayscale compensation curve equation; based on the default mura compensation value and the final grayscale compensation curve equation, calculating supplementary mura compensation values for pixels in the X-th area other than the first pixel; re-performing the mura compensation to the X-th area.

1. Field of the Invention
The present invention relates to the field of display, and in particular to the field of mura phenomenon compensation method for display panel and display panel.
2. The Related Arts
Because of various defects in the manufacturing process of liquid crystal display (LCD), the manufactured LCD panel may have non-uniform luminance and display various mura phenomena (the mura phenomenon refers to the marks caused by non-uniform luminance of the display panel.)
To improve the luminance uniformity of the display panel, some mura compensation methods are developed. For example, an external high-resolution camera is used to take a few grayscale frames (pure white screen with different luminance) mura forms. By comparing the brightness of the center position of the display panel, the brightness difference between the surrounding area and the center position is computed, and then compensates the grayscale value of the mura location (by reducing the grayscale value for area brighter than the center position to reduce brightness, and increasing the grayscale value for area darker than the center to increase brightness) to make the display panel as a whole to achieve a more consistent brightness.
In general, the reverse compensation data is stored in flash memory. Also, to reduce cost, the flash memory does not store the grayscale compensation data for each pixel. The known approach is to compress an area of n*n pixels (for example, 8*8 pixels), and each area stores the grayscale compensation data for one of the pixels in the flash. The other pixels in the area use grayscale compensation data calculated by linear interpolation.
Take Ultra High Definition (UHD) display panel (3840*2160 pixels—a display panel with 3840 columns and 2160 rows of pixels) as an example. Refer to FIG. 1, by compressing an 8*8 pixel area, the compression results in 480*270 areas (the dash square in the figure indicates an area). The data memory stores the mura compensation data corresponding to pixels at the intersections of the 1st, 9th, 17th, . . . , 2145th, 2153rd columns and the 1st, 9th, 17th, . . . , 3825th, 3833rd rows (indicated by the circled pixels). The total of 480*270 mura compensation data is stored. Moreover, to calculate the mura compensation data corresponding to the pixels of the 3834th-3840th columns and pixels of the 2154th-2160th rows, the stored mura compensation data corresponding to the 3825th column and 3833rd column are used to calculate to obtain the mura compensation data corresponding to the pixel of the 3841st column (virtual pixel with circle in the figure) with 270 mura compensation data. By using stored mura compensation data corresponding to the 2145th row and 2153rd row, the mura compensation data corresponding to the pixel of the 2161st row (virtual pixel with circle in the figure) is calculated to obtain 480 mura compensation data. Accordingly, the data memory needs to store 481*271 mura compensation data, and the mura compensation data for the remaining pixels are calculated by a timing controller (Tcon IC) based on linear interpolation with the existing 481*271 mura compensation data.
For the specific calculation for the remaining pixels, also refer to FIG. 1. Take area formed by the pixels of the 1st-8th row 1st-8th column (8*8 pixels) as example. In the area, assume that the pixel at the intersection of the 1st column and 1st row (left upper corner pixel) corresponds to a mura compensation value A′, the pixel at the intersection of the 9th column and 1st row corresponds to a mura compensation value B′, the pixel at the intersection of the 1st column and 9th row corresponds to a mura compensation value C′, the pixel at the intersection of the 9th column and 9th row corresponds to a mura compensation value D′, the pixel e′ corresponds to a mura compensation value E′, the pixel f′ corresponds to a mura compensation value F′, the pixel g′ corresponds to a mura compensation value G′; wherein, the mura compensation value A′, B′, C′, D′ are known values. After linear interpolation, the E′, F′ and G′ are calculated as follows:E′=[(8−Y′)*A′+Y′*C′]/8;F′=[(8−Y′)*B′+Y′*D′]/8;G′=[(8−X′)*E′+X′*F′]/8.
Wherein the X′ and Y′ are the number of pixels spaced apart between the corresponding pixel and the pixel at the intersection of 1st column and 1st row in the direction of row and column respectively.
However, when the mura change in an area is drastic, and the grayscale compensation data calculated by the above linear interpolation is used for compensation, as shown in FIG. 2, the area with drastic change in mura condition still shows apparent mura phenomenon (see FIG. 2 for the left and right ends of the display effect when uncompensated). The non-uniform luminance can still show after compensation; therefore, the known linear interpolation method is no longer sufficient to address the mura issue.

Mura compensation method for display panel and display panel

Shenzhen China Star Optoelectronics Technology Co., Ltd


An electric power assisted steering system of the kind in which an electric motor is operatively connected to a steering assembly through a gearbox to apply an assistance torque to the steering assembly and in which the steering assembly includes a steering column coupled at one end to a driver""s handwheel and at the other end to steerable wheels, a means being provided for generating a signal representative of the velocity of rotation of the steering column. The system includes a high pass filter which is adapted to generate, for frequencies below a prescribed threshold, a signal at least approximately proportional to steering column acceleration and representative of the inertia of the rotor of the electric motor, the latter signal being arranged to be used to compensate for the motor rotor inertia in an overall assistance torque demand as developed by the system.

The present invention relates to electric power assisted steering systems (EAS) and is concerned in particular with a method and apparatus to be incorporated in a control system for an electrically powered steering system for compensating for inertia within the system generated by the electric assist motor.
Typically, an EAS system comprises a driver""s steering wheel or handle through which the driver inputs a steering demand. The steering demand produces a torque input which has both magnitude and directional sense. The steering wheel is connected to a steering column/shaft which carries within a portion of the shaft a torque sensor for measuring the driver""s steering demand. Preferably the sensor, either alone or in combination with additional sensors, provides signals corresponding to the steering wheel position, which can be further used to determine steering speed and thus steering acceleration. All of these signals are measurements corresponding to the driver""s steering input or steering demand.
The driver""s steering demand is processed in accordance with a basic steering torque servo control which provides an output signal, dependent upon the driver""s demand, to an electric assist motor, which adds in steering assist torque into the steering shaft, downstream of the torque sensor. The electric assist motor is typically connected to the steering shaft by some form of gearbox, the ratio of which is set by determining the range of assistance torque and system response required for a particular system installation. Finally, the steering shaft is operatively connected to the steerable road wheels by a rack and pinion steering assembly, which could optionally carry the electric assist motor instead of the steering shaft depending upon the particular installation constraints.
In operation, the system has to cope with a wide variety of driver""s steering inputs and other external demands as imposed on the system during normal running, such as speed dependent self centring torques developed at the road wheels, or torsional fluctuations developed as the road wheels pass over a changing road surface. There is a need to compensate for each of these additional external system inputs if the whole steering system is to remain stable under all operating conditions.
One particular disturbance, developed within the electromechanical steering system itself, for which compensation needs to be provided, is the torsional drag induced within the steering system as a result of inertia predominantly within the electric assist motor.
It is one object of the present invention to provide a method and apparatus to compensate for torsional drag induced within the steering system as a result of reflected system inertia.
It is known within EAS systems of the present kind to add in a term to the assistance torque calculation that compensates for the above described reflected system inertia. As described for example in GB 2175551 and U.S. Pat. No. 5,740,040, this is usually done by providing a value which is proportional to the steering acceleration as derived by differentiating the steering column velocity. It has been found however that the base steering column velocity signal as measured at the steering column carries not only the driver""s steering demand velocity but also other shifting disturbances as described above which, when differentiated, induce acceleration terms into the inertia compensating calculation which has the potential to make the system unstable. Typically, the driver would be able to input a steering demand which could develop a measurable change within the system at a rate of up to 5 Hz, as could be demanded during a xe2x80x98panic steering manoeuvrexe2x80x99 to avoid an obstacle. Noise, developed from external background sources, such as running over a rough road, would typically be at higher frequencies such as in the region of 10 to 20 Hz or higher. Another object of the present invention is to compensate only for those changes within the system that can be directly attributed to the driver""s steering demand, i.e. below a frequency response which could be reasonably achieved by the driver.
In accordance with the present invention there is provided an electric power assisted steering system of the kind in which an electric motor is operatively connected to a steering assembly through a gearbox to apply an assistance torque to the steering assembly and in which the steering assembly includes a steering column coupled at one end to a driver""s handwheel and at the other end to steerable wheels, a means being provided for generating a signal representative of the velocity of rotation of the steering column, wherein the system includes a high pass filter means which is adapted to generate, for frequencies below a prescribed threshold, a signal at least approximately proportional to steering column acceleration and representative of the inertia of the rotor of said electric motor, the latter signal being arranged to be used to compensate for said motor rotor inertia in an overall assistance torque demand as developed by the system.
In one preferred embodiment, the steering column acceleration signal is applied to a gain control means to provide a torque output signal which is factored to take account of the ratio of the gear box employed in the system between the motor and the steering column or steering linkage.
Preferably, the factored torque signal is passed through a limit means which imposes a limit on the magnitude of the developed torque signal to produce a capped assistance torque demand signal. The capped assistance torque demand signal can then be added to a basic servo assistance torque demand provided by the system whereby to provide a compensated overall assistance torque demand for the system.

Compensation for motor inertia in electric power assisted steering systems


A reciprocating device for a movable member includes: a stationary member; a movable member held by the stationary member in such a manner as to be able to reciprocate; a biasing device provided between the movable member and the stationary member and adapted to bias the movable member in at least one of the reciprocating directions of the movable member; and a lock device for stopping the movable member in the course of its reciprocation, the lock device including: a cam groove formed on either the stationary member or the movable member and extending around a heart-shaped island; a lock pin having a base end section rotatably supported by either the stationary member or the movable member on which the cam groove is not formed and a tip end section bent toward the bottom of the cam groove; and a pressing device for pressing the tip end section of the lock pin toward the bottom of the cam groove, the pit section of the heart-shaped island of the lock device being equipped with a tapered surface inclined toward the bottom of a stop section of the cam groove, the tip end section of the lock pin being bent at an angle corresponding to the inclination of the tapered surface of the pit section of the heart-shaped island.

The present invention relates to a reciprocating device for a movable member, such as a movable cover of household electrical appliances.
A known reciprocating device of this type comprises, for example, a stationary member, a movable member held by this stationary member in such a manner as to be reciprocated, biasing means provided between the movable member and the stationary member and adapted to bias the movable member in at least one of the reciprocating directions, and a lock device for stopping the movable member in the course of its reciprocation (see, for example, Japanese Patent Laid-Open No. 64-41434).
The above-mentioned lock device is equipped with a cam groove provided on either the stationary or the movable member and extending around a heart-shaped island, a lock pin whose base end section is rotatably supported by either the stationary or the movable member and whose tip end section is bent toward the bottom of the above-mentioned cam groove, and pressing means for pressing the tip end section of this lock pin toward the bottom of the cam groove.
The above cam groove is equipped with an introduction path extending toward a point tapered section of the heart-shaped island, a former path extending from this introduction path along one side of the heart-shaped island while gradually decreasing its depth, a turn-back section which is one step deeper than the shallowest end of the forward path and equipped with a dead end, a stop section which is adjacent to and still one step deeper than the turn-back section and which extends along the pit section of the heart-shaped island in the middle of the other end portion thereof, an escape section which is adjacent to and one step deeper than the stop section and which extends toward the other side of the heart-shaped island up to a dead end, and a return path which extends along the other side of the heart-shaped island while decreasing its depth to communicate with the above introduction path and whose shallowest end is one step higher than the bottom of the introduction path.
Further, the present applicant has already proposed a structure having a groove-like by-pass extending across the central portion of the heart-shaped island, from the stop section toward the introduction path thereof (see Japanese Patent Application No. 2-176941).
The end section facing the stop section of the by-pass is formed one step shallower than the bottom of the stop section, and a tapered surface is formed thereon which is inclined toward the bottom of the stop section of the cam groove. The tip end section of the lock pin is bent obliquely toward the bottom of the stop section of the cam groove.
A problem with the above-described conventional reciprocating device is that the movable member thereof is liable to break if it is forcibly moved in the lock-releasing direction when in a locked position.
The locked state of the lock device can be released by moving the movable member in the locking direction again. When the movable member is moved in that direction, the tip end section of the lock pin advances from the stop section to the escape section of the cam groove, thereby releasing the lock.
If, in contrast, the movable member is forcibly moved in the lock-releasing direction, the tip end section of the lock pin, which is in the stop section of the cam groove, abuts the pit section of the heart-shaped island, and prevents any further movement of the movable member.
However, in the case of household electrical appliances, a person, such as a child, who is not accustomed to use the apparatus, may attempt to forcibly move the movable member. Such a person may try to forcibly open the movable cover of the apparatus which has been locked by means of the reciprocating device.
In such a case, the pit section of the heart-shaped island of the cam groove may be scraped or broken off by the tip end section of the lock pin. Or, conversely, the tip end section of the lock pin may be bent or broken as a result of being pressed by the pit section of the heart-shaped island.


A liquid crystal display includes an insulation substrate, a gate line and a data line disposed on the insulation substrate, a repair pattern disposed on the insulation substrate, a first passivation layer disposed on the gate line, the data line and the repair pattern and a pixel electrode and a common electrode that is disposed on the first passivation layer and that overlap each other, and a second passivation layer disposed between the pixel electrode and the common electrode where the repair pattern overlaps the pixel electrode.

(a) Field
The invention relates to a liquid crystal display.
(b) Description of the Related Art
A liquid crystal display is one of flat panel displays most widely used and includes a display device that rearranges liquid crystal molecules of a liquid crystal layer by applying voltages to electrodes so as to control an amount of transmitted light.
The liquid crystal display has an advantage of easily being thinned, but has a disadvantage of having low side visibility in comparison with front visibility. Accordingly, a method of arranging and driving liquid crystals in various methods in order to overcome the disadvantage has been developed. As a method of realizing an optical viewing angle, the liquid crystal display in which a pixel electrode and a common electrode are formed on one substrate is spotlighted.
A driver of the liquid crystal display is directly mounted to a display panel in a form of a plurality of integrated circuit ("IC") chips or is mounted to the display panel by being mounted to a flexible circuit film or the like, and the IC chips account for a large percentage of manufacturing costs of the liquid crystal display. Particularly, as the number of data lines applying data voltages becomes larger, costs of the driver of the liquid crystal display become higher.


The invention provides semiconductor chip packages, tools, and methods for preventing and for correcting leadfinger deformation caused during wirebonding in semiconductor chip package manufacturing. Disclosed are improved heat blocks and methods for their use in ensuring adequate clearance between leadfingers and adjacent heat spreaders, as well as semiconductor chip package assemblies wherein a selected clearance between leadfingers and parallel surfaces may be assured. Methods of the invention include steps for supporting the proximal ends of the leadfingers using the wirebonding cavity of a heat block. Thus supported, a plurality of bondwires are attached to couple bond pads of the semiconductor chip to the proximal ends of leadfingers. Thereafter, the clearance between the wirebonded proximal ends of the leadfingers and the adjacent parallel surface of the heat spreader is adjusted using a spacing cavity of the heat block. In preferred embodiments of the invention, a plurality of bondwires couple a plurality of bond pads of the semiconductor chip to the proximal end of a single leadfinger, with assured clearance between the proximal end of the leadfinger and an underlying surface.

In leaded semiconductor chip packages, a chip is generally affixed to a leadframe using a permanent adhesive. In some cases, it is desirable to enhance the thermal performance of a package by improving the path for the departure of heat from the chip to an outside surface of the package. In many such cases, it is known to incorporate a heat spreader into the leadframe structure, for example, by welding, taping, or gluing the heat spreader to the chip-mount portion of the leadframe. In other cases, a heat spreader is riveted in place on the leadframe, and a chip is mounted directly to the heat spreader surface. In either case, due to its heat conduction properties, the heat spreader is typically made from metal, such as copper or copper alloy. In some instances, in order to increase its heat conduction, the heat spreader is large relative to the chip, extending in a plane parallel with the proximal ends of the leadfingers. This type of arrangement of chip, leadfingers, and heat spreader at least partially underlying the leadfingers, is used in many applications, but is not without its problems.
Electrical connections within a semiconductor chip package are commonly made by bonding wires from bond pads on the surface of the chip to the proximal ends of the leadfingers. The leadfingers typically extend from one end adjacent to a gap in the leadframe proximal to the chip, to a distal end at the exterior of the package where electrical connections may be made to the outside world. During a typical wirebonding process, a ball bond is formed on a bond pad of the chip using heat, pressure, and in many cases ultrasonic vibrations. The wire is then pulled to the proximal end of a leadfinger, and a stitch bond is formed there, also using some combination of heat and pressure, and often ultrasonic vibrations.
Wirebonding equipment generally includes a heat block, made of rigid material, for providing heat and supporting the leadframe during wirebonding. Pursuant to a wirebonding process, the heat block is heated to a predetermined temperature. A leadframe assembly including a leadframe, chip, and heat spreader, is placed in a cavity provided in the heat block and is typically secured in place by an associated clamp. Wirebonds are then made from the chip to the leadfingers and the assembly is thereafter removed from the heat block for further processing, such as encapsulation and ultimate separation. In many applications, supporting the proximal ends of the leadfingers during wirebonding is simply a matter of placing the leadframe assembly into a supporting cavity of a heat block.
The present invention is directed to overcoming, or at least reducing, problems present in the prior art, and contributes one or more heretofore unforeseen advantages, indicated herein, for providing improved heat blocks, and related methods for their use in the manufacture of improved semiconductor chip package assemblies.

Semiconductor chip package assembly method and apparatus for countering leadfinger deformation


A method and system is provided of enhancing the variability of high-quality computer graphics from limited sources utilizing minimal processing and bandwidth in real time. An underlying backdrop 3D model is generated. Next, Partially Rendered Pixels (PRP) of animated 3D characters are generated having lighting and texture information compatible with the underlying backdrop 3D model. The texture and other ancillary data are removed or omitted from the PRP animated 3D characters leaving only a detailed skeletal model. The extracted texture and other ancillary data are placed in a separate PRP lookup table. A fully rendered video segment is created from the PRP and a selected set of texture and other ancillary data.

1. Field of the Invention
The present invention relates generally to computer graphics, such as: video games, medical imaging, digital watermarking and the like. More particularly, this invention relates to methods for greatly enhancing the variability of computer graphics from limited sources utilizing minimal processing and bandwidth. Specifically, this innovation resolves the problem of the generation of a video file or stream in real time producing complex video output consisting of realistic models of three-dimensional (3D) objects with varying backdrop scenes.
2. Background
Computer generated graphics have substantially progressed since their introduction in the 1950's. One of the first interactive video games to feature recognizable, interactive graphics—"Tennis for Two"—was created for an oscilloscope by William Higinbotham to entertain visitors in 1958 at Brookhaven National Laboratory by simulating a tennis match. In 1961 at MIT (Massachusetts Institute of Technology), Steve Russell, created the second video game, "Spacewar" running on a Digital Equipment Corporation (DEC) PDP-1 model computer. Both of these pioneering video games employed extremely simple line and dot graphic primitives bearing only a faint resemblance to any real world counterparts.
In the 1970's the concepts of the hidden-surface algorithm, Gouraud and Blinn-Phong shading models, Z-axis plotting, bump mapping, and other innovations provided early breakthroughs in computer generated graphics that laid the foundation for much more detailed video graphics. However, the computer processing power available at the time hampered the lifelike appearance of computer video generated by these techniques.
Now, with the emergence of 32-bit and higher microprocessors as well as specialized Graphics Processing Units (GPUs) hardware, pre-rendered computer graphics used in films and video games are nearly scientifically photorealistic—i.e., almost impossible to discern the difference between real world and computer generated. However, real time graphics produced on very high-end systems, while closely simulating photorealism, do not achieve the photorealistic levels of pre-rendered graphics. The difference in output quality being attributable to the requirement for real-time graphics to produce an uninterrupted continuous varying video file or stream.
Thus, being able to generate photorealistic appearing 3D graphics in real time has become the holy grail of the video gaming industry and drives a continued push in hardware and software capability with new innovations that provide a strategic, albeit temporary, advantage for the innovating entity. Known techniques, and traditional approaches take the standard 3D geometry and texture model approach, rendering pixels using light and shading models in real time. Unfortunately, this approach has led to computationally expensive systems requiring dedicated hardware GPUs in conjunction with high-speed servers with sizable communication bandwidth requirements. Such hardware and bandwidth and the lack of it in mobile and home user environments have proven to be problematic.
For example, if photorealistic appearing 3D graphics are rendered at a central site (i.e., "render farms" with significant computational assets running continuously over hours) and downloaded to home and mobile systems in more or less real time the computational requirements problem can be solved by concentrating the expensive graphics hardware at the host's central site and distributing the generated photorealistic looking 3D graphics as video streams to individual consumers with mobile, home, and other platforms. Thus, in this model, the consumer's hardware is principally performing a display function that is not necessarily computationally intensive. However, this model has the disadvantage of high bandwidth requirements on a continuous basis that are typically expensive and may not be available to many users—especially mobile users. Conversely, if photorealistic looking 3D graphics are rendered on the consumer's device, the bandwidth requirements can be reduced; however, typically the consumer's device(s) is not able capable of performing computational processing rendering in real time with the graphic output quality significantly degraded at best.
Another example is for the photorealistic looking 3D graphics to be pre-rendered and downloaded to the consumer's device in advance of interactive play, thereby maintaining high levels of computational processing at a central site while at the same time reducing bandwidth requirements since the graphics could be downloaded in time multiples of their real time playback. However, the typical pre-rendered 3D graphics large file size severely restricts the variety of options available for real time game playback thereby significantly reducing consumer enjoyment of multiple plays since the video will be familiar after only a few viewings.
With medical imaging the tradeoffs between computationally expensive hardware and bandwidth are typically reduced with most viewing local to the hardware that generated the images. However, medical imaging typically is associated with very complex 3D models (i.e., human body) from multiple scan sources where the doctor chooses in real time to display various two dimensional (2D) slices of "compound scans" of the body that were previously acquired. Thus, the presentation of these 2D slices must occur real time or near real time with an accompanying substantial processing burden. When dynamic information (e.g., Doppler blood flow) is superimposed on these 2D slices (e.g., false color velocity of blood flow) the computational requirements become even more extensive. If these types of 2D compound scans are transmitted to a remote location, the available bandwidth also can potentially become problematic ultimately resulting in the sort of tradeoffs previously discussed with gaming.
Finally, pre-rendered graphics digital watermarking is well known in the art and is often utilized to ensure copyright protection as well as embedding other metadata. However, digital watermarking with real time generated graphics is virtually unknown, partially due to the computational difficulties of embedding digital watermarks in video streams generated real time. The computational hardware required to include digital watermarks into a real time video stream being typically prohibitively expensive—both in terms of computational cycles and economics.
Attempts have been made to reduce processing requirements for rendering images in real time. For example, U.S. Pat. No. 5,860,924 (Quistgaard) teaches serially ganging multiplicities of processors each with specific image processing tasks thereby reducing the processing requirements on any single processor. However, "Quistgaard" typically requires expensive custom hardware or at the very least multiplicities of servers in serial and parallel configurations with the associated logistical and economic problems inherent in these types of complex processing configurations.
U.S. Patent Application Publication No. 2008/0012870 (Gies et al.) discloses analyzing each frame of a video stream and related color profile indicating parameters of the color space of the video stream and then converting each frame from a source color space to a working color space. The intent of this process is to convert in real time a video stream from one format to another—e.g., composite NTSC (National Television System Committee) format to HDTV (High-Definition TeleVision) format (paragraph [0024] of "Gies"). Thus, while "Gies" discloses efficiently converting one format of video to another, it does not address the core problems of source computational power and bandwidth tradeoffs nor how to maintain photorealistic looking graphics on consumer devices with variety and dynamic outcomes determined in near real time.
Color space conversion is also taught in U.S. Pat. No. 7,593,021 (Tynefield, Jr. et al.). In this process, color data is converted from one space to another with a driver determining if a color conversion function will be enabled and if so either with a single linear conversion or flagged to perform a non-linear conversion. Again, while this process discloses efficient methods of altering a video stream or file, it does not address the core problems of source computational power and bandwidth tradeoffs nor how to maintain photorealistic looking graphics on consumer devices with variety and dynamic outcomes determined in near real time.
U.S. Pat. No. 7,038,690 (Wilt et al.) discloses methods and systems for interfaces between video applications and consumer display screens that allow applications to intelligently use display resources of the consumer's device with a graphics arbiter providing display environment information to the video application, possibly transforming the video stream or file or allowing another application to transform the video stream or file. With "Wilt" the graphics arbiter also informs applications of the estimated time when the next frame will be displayed on the screen, thereby allowing applications to tailor output to the estimated display time, thus improving output quality while decreasing resource waste by avoiding the production of "extra" frames that will never be viewed. Thus, with "Wilt", processing efficiencies are gained via the graphics arbiter although source computational power and bandwidth tradeoffs are not significantly reduced. Additionally, "Wilt" makes no attempt to resolve the problem of maintaining photorealistic looking 3D graphics on consumer devices with variety and dynamic outcomes determined in near real time.
Thus, there is a need for a method or system to reduce the tradeoff between source computational power and bandwidth when transmitting a video stream or file of photorealistic appearing graphics from a central site to a consumer device. Ideally, this method or system would also increase the variety of dynamic outcomes displayable in near real time.

Generation of variations in computer graphics from intermediate formats of limited variability, including generation of different game appearances


A developer supply container includes a developer accommodating body configured to contain developer, with the developer accommodating body being rotatable about a rotational axis. A developer discharging body is provided in fluid communication with the developer accommodating body, with the developer discharging body having a discharge opening provided in a bottom portion of the developer discharging body and configured to discharge the developer from the developer discharging body, and with the developer accommodating body being rotatable relative to the developer discharging body. A track is provided on each of opposite sides of the developer discharging body.

Conventionally, an image forming apparatus of an electrophotographic type such as an electrophotographic copying machine uses a developer (toner) of fine particles. In such an image forming apparatus, the developer is supplied from the developer supply container with the consumption thereof by the image forming operation.
Since the developer is very fine powder, it may scatter in the mounting and demounting of the developer supply container relative to the image forming apparatus. Under the circumstances, various connecting types between the developer supply container and the image forming apparatus have been proposed and put into practice.
One of conventional connecting types is disclosed in Japanese Laid-open Patent Application Hei 08-110692, for example.
With the device disclosed in Japanese Laid-open Patent Application Hei 08-110692, a developer supplying device (so-called hopper) drawn out of the image forming apparatus receives the developer from a developer accommodating container, and then is reception reset into the image forming apparatus.
When the developer supplying device is set in the image forming apparatus, an opening of the developer supplying device takes the position right above the opening of a developing device. In the developing operation, the entirety of the developing device is lifted up to closely contact the developing device to the developer supplying device (openings of them are in fluid communication with each other). By this, the developer supply from the developer supplying device into the developing device can be properly carried out, so that the developer leakage can be suppressed properly.
On the other hand, in the non-developing operation period, the entirety of the developing device is lowered, so that the developer supplying device is spaced from the developing device.
As will be understood, the device disclosed in the Japanese Laid-open Patent Application Hei 08-110692 requires a driving source and a drive transmission mechanism for automatically moving up a down the developing device.

This patent is subject to a terminal disclaimer.

Developer supply container and developer supplying system


Haptic feedback generation methods and apparatuses relating to the field of haptic feedback are provided. The method comprises: in response to determining that a first part of a user body is touching a target position of an object, sending, by a device comprising a processor, a first mechanical wave to the object via a first medium comprising the first part; and sending, to the object via a second medium, a second mechanical wave that is used to form a haptic signal at the target position with the first mechanical wave, wherein the second medium comprises a second part, touching the object, of the user body. A source for forming the haptic signal can be at the target position, to cause that an effective haptic feedback to the user can be formed with little energy consumption, and poor experience of the user caused by vibration of an entire object is avoided.

Haptic feedback is a technology in which an apparatus gives a haptic feedback to a user operation. For example, when a user clicks a corresponding menu on a smart phone or a tablet computer, the apparatus may vibrate under drive of a built-in motor, to cause that the user may know that the apparatus has received an operation instruction. Haptic feedback is widely applied when a user drives a car or when observation is inconvenient for a user.
In an existing haptic feedback technology, a built-in motor drives vibration of the entire apparatus, which causes large energy consumption and affects user experience.


A method and structure for receiving user input utilizing a round interactive device, where the round interactive device comprises a rotating bezel around a round capacitive touch screen that is attached to a uniquely designed base with push button functionality, all of which combined allow for user inputs to provide feedback regarding customer experiences.

Currently there are a number of solutions for collecting customer feedback after making a connection with a customer. One of these solutions attempts to use comment cards that are placed at the point of sale or at the point of closing the transaction, but this solution fails to meet the needs of the market as comment cards require action by a user and are often overlooked. Another solution attempts to use smart phone devices, email campaigns, and online ratings, but these solutions are similarly unable to meet the needs of the market as they too are often intrusive, require specific action by a user, and often are simply ignored.
However, none of these approaches are intuitively interactive or an actively engaging experience.

Methods and systems for receiving user input utilizing a round interactive device


An inkjet head includes a cavity plate having a plurality of pressure chambers arranged in matrix, a piezoelectric sheet laminated on the cavity plate, and a power supply board. A plurality of substantially rhombus driving electrodes are formed on the piezoelectric sheet in a matrix at positions corresponding to the pressure chambers. A first contact land extends from one of the acute angle corners of each driving electrode. The driving electrodes are arranged such that the first contact land extending from one driving electrode is placed between two driving electrodes adjacent to said one driving electrode. The power supply board has a plurality of second contact lands formed at positions corresponding to the first contact lands. The second contact lands are connected with respective ones of the first contact lands for power supply.

The present invention relates to an inkjet head, and more particularly to an inkjet head provided with a piezoelectric sheet having driving electrodes formed thereon at high density.
An inkjet head provided with a piezoelectric sheet is disclosed, for example, in Japanese patent application provisional publication HEI 11-34323. FIG. 1A shows a sectional view of a part of the inkjet head disclosed in the above-mentioned publication. As shown in FIG. 1A, the inkjet head has a base plate 1010 in which a plurality of pressure chambers 1001 are formed. The inkjet head further has a conductive plate 1012, a piezoelectric layer 1003, and a plurality of driving electrodes 1002, which are laminated on the base plate 1010 in this order. The driving electrodes 1002 are formed on the piezoelectric layer 1003 at positions corresponding to respective pressure chambers 1001.
In the above-identified inkjet head, driving voltage is applied between the driving electrodes 1002 and the conductive plate 1012 so that portions of the piezoelectric layer 1003, defined therebetween, deforms due to piezoelectric effect. The deformed portions of the piezoelectric layer 1003 apply pressure to ink filled in the pressure chambers 1001 to eject the ink from nozzles (not shown) of the inkjet head.
FIG. 1B is a top view of the driving electrode 1002 of the inkjet head shown in FIG. 1A. The driving electrode 1002 has a body 1004 and an extended portion 1005. The body 1004 is formed slightly smaller than the pressure chamber 1001 and is located directly above the corresponding pressure chamber 1001. The end 1006 of the extended portion 1005 is located outside the area above the pressure chamber 1001. The end 1006 of the extended portion 1005 serves as a contact portion that is to be connected with a power supply line for applying the driving voltage to the driving electrode 1002.
Generally, a flexible printed board is connected to an inkjet head configured as above for applying driving voltage to each of the driving electrodes 1002. The flexible printed board includes a plurality of contact points arranged in a line in a vicinity of one edge thereof. The flexible printed board is electrically connected with the inkjet head by connecting those contact points with the contact portions (ends 1006) of the driving electrodes 1002. Since the contact points are arranged in a line, the driving electrodes 1002 of the inkjet head are formed and arranged such that the contact portions (ends 1006) thereof are also arranged in a line in a vicinity of one edge of the piezoelectric layer 1003.
This arrangement of the ends 1006, however, requires the extended portions 1005 of the driving electrodes 1002 to be extended from the bodies 1004 thereof for significant lengths, which in turn restricts the density of the driving electrodes 1002 formed on the piezoelectric layer 1003, the density of the pressure chambers 1001 formed right below the driving electrodes 1002, and hence the printing resolution that the inkjet head can achieve.
Therefore, there is a need for an inkjet head provided with a piezoelectric sheet having driving electrodes arranged on the piezoelectric sheet at high density.


Method of making metal electrode, characterized by having the steps of:. forming double layers of metal on the principal face of the semiconductor substrate which has electrode pads contacting specified regions of the semiconductor substrate, PA0 forming a photosensitive film on the whole surface of the metal double layers, PA0 etching said photosensitive film in a manner to selectively form openings on areas above the electrode pads, thereby exposing parts of the double layers above the electrode pads, PA0 forming metal bumps on said exposed surfaces of said double layers, PA0 removing said photosensitive film while retaining narrow surrounding parts around said metal bumps, and PA0 etching said double layers of metal by utilizing said narrow surrounding parts as etching mask, thereby removing the parts of said double layers which is covered by said narrow surrounding parts.

1. Field of the Invention
This invention relates to a method of making semiconductor device, especially with metal bumps.
2. Prior Art
In recent years, fabrication method of a semiconductor device wherein metal bumps are formed on semiconductor substrate for contacting to external leads directly therewith by simultaneous thermo-compression bonding, thereby dispensing with one-by-one bonding of fine gold wires. The metal bumps are generally formed by plating on metal layers which are formed on electrode pads formed on specified parts of the substrate. Conventional method of forming the metal bumps has shortcoming that bonding force of the bumps on the substrate is not sufficient, because an etchant used in the process likely etches the electrode pads.
FIG. 1(a), FIG. 1(b) and FIG. 1(c) show steps of such conventional method. The conventional method is elucidated in detail referring to FIG. 1(a) to FIG. 1(c). First, electrode pads 2 of aluminum film are formed on specified parts of the principal face of the silicon substrate 1 to connect it and lead out. On all the way of the principal face, an insulating film 3 of, for example, SiO.sub.2 is formed by known chemical vapor deposition method, and then, openings 31 are formed by means of known photo-etching method in a manner to expose almost area of the electrode pads 2, but retaining peripheral parts of the electrode pads 2 covered under the insulating film 3.
Next, by means of sputtering method or vacuum deposition method, for example, resistor heating method or electron-beam method, metal double layers 4' and 4" are formed on all the way of the principal face. The metal layers 4' and 4" are called barrier metals and are formed of two layers, a lower layer 4' and an upper layer 4" as shown in FIG. 1(a). The lower layer 4' is formed with such a metal that can make a strong contact with the electrode pads 2 of aluminum film and the chemical-vapor deposited insulating film 3 of such as SiO.sub.2. For example, chromium or titanium is suitable for the lower layer 4'. The upper layer 4" is formed with such a metal on that a metal bump 5 can be firmly formed in the subsequent step. For example, copper, nickel, gold, silver, platinum or/and lead are suitable for the upper layer 4".
Then, a photoresist film 6 is formed on all the way of the double metal layers 4' and 4", and openings 61 are formed by known photolithographic method so as to have the area corresponding to that of the electrode pad 2 thereby exposing the upper layer 4" therethrough. Thereafter, metal bumps 5 of thick metal layer is formed as shown in FIG. 1(b) by known electrolytic plating on the exposed area of the upper layer 4" by utilizing the exposed double metal layer 4' & 4" as electrode. Gold is suitable for the material of the metal bumps.
Then, the photoresist film 6 is removed by using known photoresist stripper, and subsequently, parts of the double layers 4' and 4" which are not covered by the metal bumps 5 are etched away by utilizing the metal bumps 5 as etching masks as shown in FIG. 1(c).
Inventors found that the abovementioned conventional method of making the metal bump has the following shortcomings that:
(1) The gold bumps 5 are utilized as etching masks in chemical etching to remove the metal double layers 4' and 4". In the etching, strong etchant comprising mixture of pottasium ferricyanide and sodium hydroxide or ferric chloride is used, and therefore, undesirable undercuttings of the metal double layers 4' and 4" occurs, thereby etching the double layers under the gold bump by the extent of etching width x. Sometimes the etching width reaches 5-10 .mu.m inward from the peripheral of the metal bump 5, and sometimes dissolves parts of electrode pad so as to make hollow 9 as shown in FIG. 1(c). Such undesirable dissolving causes electrical failure as well as decrease of contacting power of the metal bumps 5.
(2) The abovementioned shortcoming can be overcome when the openings (for electrolytic plating) in the photoresist film 6 is made larger than those of the openings in the SiO.sub.2 film 3 by the extent of the undercutting width x. However, such measure necessarily increases the width of the metal bumps 5, as well as increases pitches of the metal bumps. This leads undesirable increase of the size of IC or LSI wherein many lead wires must be integrated within a limited area.
In order to improve the abovementioned shortcomings, the inventors made preliminary improvements as shown in FIG. 2 and FIG. 3. These improvements are not yet disclosed to the public, and hence do not form the state of the art, but are described here for better understanding of the object and are only preliminary steps to the present invention.
In the inventors' preliminary improvement of FIG. 2, the feature is to make the area of the metal double layers 14' and 14" larger than that of the area of the metal bump 5, thereby to prevent the undercutting.
First, electrode pads 12 of aluminum film are formed on specified parts of the principal face of the silicon substrate 11 to connect it and lead out. On all the way of the principal face, an insulating film 13 is formed by known chemical vapor deposition method, and then, openings 131 are formed by means of known photo-etching method in a manner to expose almost area of the aluminum electrode pad 12, but retaining peripheral parts of the electrode pads 12 covered under the insulating film 13.
Next, by means of sputtering method or vacuum deposition method, for example, resistor heating method or electron-beam method, metal double layers 14' and 14" are formed on all the way of the principal face. The metal layers 14' and 14" are called barrier metals and are formed of two layers, a lower layer 14' and an upper layer 14" as shown in FIG. 2(a). The lower layer 14' is formed with such a metal, that can make a strong contact with the electrode pads 2 of aluminum film and the chemical-vapor deposited insulating film 13 of such as SiO.sub.2. For example, chromium or titanium is suitable for the lower layer 14'. The upper layer 14" is formed with such a metal on that a metal bump 5 can be firmly formed in the subsequent step. For example, copper, nickel, gold, silver, platinum or/and lead are suitable for the upper layer 14".
Then, a photoresist films 15 are formed on the upper layer 14" in a manner to have the areas which are a little wider than the areas of the electrode pads 12. Subsequently, the exposed areas of the upper layer 14", namely the parts of the upper layer 14" which are not covered by the photoresist films 15, are removed by a chemical etching by utilizing the photoresist films 15 as etching masks as shown in FIG. 2(b). The lower layer 14' is retained all the way of the principal face for the sake of later use as electric conductor in the step of electrolytic plating of the metal bumps. The retained lower layer 14' is used for forming the metal bumps on the regions of P-type conductivity formed in the semiconductor substrate of the N-type conductivity.
Then, the first photoresist film 15 is removed by known photoresist stripper, and subsequently, a second photoresist film 16 is formed by known photolithographic method in a manner to have openings 161 which are substantially over the area of the electrode pads 12. Thereafter, by utilizing the exposed parts of the lower metal layer 14' as electric conductor, a metal suitable for metal bump, such as gold, is plated by electrolytic plating method by utilizing the lower metal layer 14' as electric conductor and the exposed part of the upper metal layer 14" as electrode, so that the gold bumps 17 are formed on the exposed area of the upper layer 14" as shown in FIG. 2(c).
Next, the second photoresist film 16 is removed by known method, and subsequently, the lower metal layer 14' of the part which is not covered by the upper metal layer 14" is removed by known selective etching method by utilizing the upper metal layer 14" as the etching mask, thus completing the bump construction as shown in FIG. 2(d).
The method of FIG. 2 still has the following drawbacks:
(1) By using the upper metal layer 14" as the etching mask in the final stage, the upper metal layer is also etched to some extent, and therefore, the etchant infiltrates into the double metal layer from the peripheral part 18 of the interface between the metal bump 17 and the upper metal layer 14", into the aluminum electrode pad 12. Therefore, the infiltration of the etchant undesirably etches peripheral parts of the electrode pad 12, thereby producing electrical unstability of the device.
(2) For the upper metal layer 14" copper layer is suitable for obtaining strong mechanical contacting force with the overlying plated layer. The copper layer 14" is likely to form oxide film thereon in the subsequent steps. The first photoresist film 15 is processed with post-baking at 140.degree. C. to 200.degree. C. in order to strengthen adhesive force on the upper metal layer 14". Such post-baking is generally used when such photoresist film is used as etching mask for etching oxide-covered copper layer 14". As a result of the post-baking the photoresist film becomes very strong, and hence, removing of it requires immersing it for 5 to 10 minutes in 90.degree. C. to 100.degree. C. hot very strong solvent (mainly consisting of surface actant) called J-100. Such strong solvent at such high temperature undesirably etches the upper metal layer 14" with such a high etching speed of 500.degree. A per 6 minutes. Furthermore, the surface of the upper metal layer 14" is contaminated by the solvent, and therefore adhesive power between the metal bump 17 and the copper layer 14" is decreased and/or yield of forming the metal bump 17 becomes very poor.
(3) When a region 11' of P-type conductivity is formed as shown in FIG. 3 in an substrate 11 of N-type conductivity, and a metal bump 17' is formed on the P-type region 11', then it is necessary to use the lower metal layer 14' as electric conductor for the electrolytic plating. Namely, in FIG. 3, in order to form the metal bump by electrolytic plating method, the substrate 11 must be connected to the negative terminal B of a D.C. power source. In FIG. 3 parts corresponding to those of FIG. 2(d) are designated by corresponding numerals, and 12' and 13' designate electrode pad and insulating layer, respectively. When the substrate 11 is connected to the negative terminal, then a plating current can flow through the metal double layers 14' and 14" formed on the N-type region 11 of the substrate to the substrate 11, but another current from the metal double layer 14' and 14" formed on the P-type region 11', through the P-type region 11', to the N-type substrate 11 hardly flows, since the P-type region 11' and the N-type substrate 11 form a P-N junction of the reverse direction to the current. Therefore, forming of metal bump 17' on the P-type region is not possible. Therefore, it can be considered to use the lower metal layer 14' as electric path for the electrolytic plating to be connected a negative terminal A of a D.C. power source. But the lower metal layer 14' is made with chromium or titanium, in order to serve as barrier layer against diffusion of the overlying cupper and gold into the electrode pad 12' and further into the semiconductor substrate 11 or into the N-type region 11', and such metal as chromium or titanium has high resistivity for the electric path for plating. Therefore, the metal bump 17' formed on the P-type region 11' has smaller height (thickness) than other bumps 17 formed on the N-type substrate 11. Such non-uniform heights of the bumps causes unreliable contactings in the subsequent press-bonding to the external lead wires.
The specific resistivity of the vapor-deposited chromium film 14' changes responding with speed of vapor-deposition and thickness of the film 14'. For example, a 1,000 A thick chromium film made with the speed of 1A per second has 10.sup.-2 .OMEGA.cm resistivity, the same made with the speed of 2A per second has 10.sup.-3 .OMEGA.cm and the same made with the speed of 5A per second has 8.times.10.sup.-4 .OMEGA.cm. According to our experiment, the same chromium film made with the speed of 2.2-2.9A per second shows the resistivity of 1.7.times.10.sup.-3 .OMEGA.cm.
In FIG. 3, provided that the distance of the part where chromium layer 14' is exposed between the first metal bump 17 and the second metal bump 17' is 0.4 mm, the width is 50 mm and the thickness is 1,000A, then the resistance of the chromium layer of this part is 1.7.OMEGA., and when the distance is 1.2 mm the resistance of the same part is 5.1.OMEGA.. When the metal bumps 17 and 17' of gold are formed by electrolytic plating, provided that the plating is made with the current density of 0.035 mA/mm.sup.2, then on the double metal layers on the electrode pad 12 on the N-type substrate 11 the plating is made with the current density of 0.035 mA/mm.sup.2. But, on the double metal layers on the electrode pad 12 on the P-type region 11' the plating is made with the current density of 0.029 mA/mm.sup.2 for the abovementioned distance of 0.4 mm and 0.023 mA/mm.sup.2 for the distance of 1.2 mm. As a result of calculation, the plating speed on the N-type substrate 11 is 11.2 .mu.m/hour for the above-mentioned current density of 0.035 mA/mm.sup.2, while the plating speed on the P-type region 11' is 9.2 .mu.m/hour for the current density of 0.029 mA/mm.sup.2 and 7 .mu. m/hour for the current density of 0.023 mA/mm.sup.2. Thus, due to the non-uniformity of the plating speed, the height of the metal bump differs as shown in FIG. 3. Furthermore, because the chromium layer 14' has the high resistivity, only on the parts which are close to the part connected to the negative terminal B the metal bump becomes tall while they are lower in more apart parts.

Method of making metal electrode of semiconductor device

Matsushita Electric Industrial Co., Ltd.


A molded case circuit breaker having a thermal-magnetic trip unit is provided with a mechanical rating plug to allow a number of circuit breakers of different ampere ratings to be used within a common-sized enclosure. Multiple mechanical rating plugs are stored at the place of distribution to adapt the common enclosure to a specific ampere rating at a substantial savings in time, labor and materials.

The advent of electronic trip units allows the use of an electronic rating plug to set the circuit breaker ampere rating within a common-sized industrial-rated circuit breaker enclosure. Wherein earlier circuit breakers employing thermal-magnetic trip units were designed to meet the various circuit breaker ampere ratings by conforming the size of the circuit breaker components and the circuit breaker enclosure, a large variety of such circuit breakers were stored at the distribution site to meet the electrical distribution market requirements. U.S. Pat. No. 4,649,455 entitled "Rating Plug for Molded Case Circuit Breaker" describes one example of the use of an electronic rating plug to set the circuit breaker ampere rating.
U.S. Pat. No. 4,679,016 describes an industrial-rated circuit breaker design that is economically assembled in an automated process. The circuit breaker utilizes a thermal-magnetic trip unit to interrupt circuit current under overcurrent conditions within a protected circuit. To accommodate the various circuit breaker ampere rating requirements, the circuit breaker entails several sizes. It would be economically advantageous to use a common-sized enclosure with such a circuit breaker employing a thermal-magnetic trip unit in view of the lower cost with the thermal-magnetic trip unit per se.
Accordingly, one purpose of the invention is to provide a so-called "mechanical rating plug" to allow circuit breakers using thermal-magnetic trip units to be arranged within a common-sized enclosure in a manner similar to the circuit breakers using an electronic trip unit.

Molded case circuit breaker mechanical rating plug