Abstract: A coating composition useful for a finish for automobiles and trucks in which the film forming binder comprises an acrylic polymer having at least two reactive anhydride groups, an epoxy-containing crosslinker, and an alkoxysilane copolymer. The composition may be used as a one-package system with a reasonable pot life. The composition is characterized by improved environmental resistance.

Abstract: A coating composition useful for a finish for automobiles and trucks in which the film forming binder comprises an acrylic polymer having at least two reactive acid groups, an epoxy-containing crosslinker, a melamine resin, and an epoxy-silane modifying agent. The composition may be used as a one-package system with a reasonable pot life. The composition is characterized by improved environmental resistance.

Abstract: A thermosettable resin composition having a viscosity that decreases during processing temperatures and increases as the temperature is raised to curing temperatures is provided. The composition comprises thermosettable resins and thermoplastic particles that are insoluble in the thermosettable resins at processing temperatures but soluble in the thermosettable resins at curing temperatures. Prepregs prepared from the thermosettable resin composition are also provided.

Abstract: An adhesive composition comprising (a) an epoxy resin obtained by reacting a 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane dianhydride with an alcohol or alcohol derivative, followed by reaction with an epoxy compound having two or more epoxy groups, or an epoxy resin obtained by reacting a 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane with an epoxy compound having two or more epoxy groups and (b) a curing agent is suitable for bonding semiconductor chips to a copper frame with a small warpage of the chips.

Abstract: Epoxy resin compositions for sealing semiconductor elements are disclosed and include an epoxy resin, a maleimide-modified siloxane compound represented by the formula (1) and an allylphenol-novolac resin represented by the formula (2) as a curing agent, and demonstrate low stress, high heat resistance and moldability. ##STR1## wherein, R.sub.1 denotes a methylene group a phenylene group or a substituted phenylene group,R.sub.2 denotes a methyl group, a phenyl group or a substituted phenyl group,n denotes 1 when R.sub.1 denotes phenylene or substituted phenylene groups, or 3 or 4 when R.sub.1 denotes a methylene group,m denotes an integer of from 1 to 100,l denotes an integer of from 1 to 100, and.kappa. denotes an integer of from 1 to 100.

Abstract: A two-pack type curable composition comprising:A. a first composition containing (A-1) an organic elastomeric polymer having at least one silicon-containing group to the silicon atom of which a hydroxyl group and/or a hydrolyzable group are bonded and which is cross linkable through formation of a siloxane linkage in a molecule and (A-2) a curing agent for an epoxy resin, andB. a second composition containing (B-1) an epoxy resin, (B-2) a curing catalyst for the organic elastomeric polymer having at least one silicon-containing reactive group and (B-3) at least one member selected from the group consisting of acidic fillers and carboxylic acids, which has good storage stability.

Abstract: An epoxy resin molding material for sealing of electronic components comprising(A) an epoxy resin;(B) a phenolic compound;(C) a resin mixture obtained bydispersing, in a form of particulates, in a dispersion medium which is a portion or all of at least one of the epoxy resin and the phenolic compound, a mixture of a vinyl group-containing organopolysiloxane and a .tbd.SiH group-containing organopolysiloxane whose total volatile loss after heating at 105.degree. C. for three hours is not more than 3% by weight, and allowing the vinyl group-containing organopolysiloxane and the .tbd.SiH group-containing organopolysiloxane to react with each other and to cure; and(D) an inorganic filleris excellent in thermal shock resistance, soldering resistance, moisture resistance, thermal stability, moldability and marking properties.

Abstract: An expoxy resin composition, an epoxy resin cured product obtained therefrom, and a bonding method using the composition are disclosed. The epoxy resin composition comprises an epoxy resin composition comprising (A) 100 parts by weight of an epoxy resin, (B) from 1 to 80 parts by weight of a heat activatable hardener, and (C) from 10 to 100 parts by weight of an aromatic thermoplastic resin powder having a glass transition temperature of 120.degree. C. or more and an average particle diameter of 200 .mu.m or less, said components (A), (B) and (C) being present in a phase separation state.

Abstract: A thermosetting resin composition contains (A) an imide compound having a maleimide group, (B) an epoxy resin, (C) a phenolic resin, and optionally, (D) an aromatic polymer/organopolysiloxane copolymer. Component (B) and/or (C) includes a compound containing a naphthalene ring having an allyl group and preferably, a compound containing a naphthalene ring and a double bond conjugated with an aromatic ring. The composition is easily workable and cures to products having improved heat resistance, low thermal expansion, and low water absorption.

Abstract: Inflammable synthetic thermoplastic resins are rendered flame retarded by incorporating therein to 100 parts by weight thereof from 5 to 50 parts by weight of 2,4,6-tris (2,4,6-tribromophenoxy)-1,3,5-triazine having a melting point ranging between 225.degree.-235.degree. C., from 5 to 50 parts by weight of a bis-tetrabromophthalimide, 0-50 parts by weight of a bromine-containing epoxy polymer having a molecular weight from 1,000 to 50,000 and from 1 to 20 parts by weight of antimony trioxide.

Abstract: A machinable, high strength epoxy tool which is the polymeric reaction product of a mixture containing 5 to 12 weight percent of a bisphenol A epoxy, 3 to 8 weight percent of at least one polyoxypropylene amine catalyst, 60 to 85 weight percent of a mixture of no less than three different sized particulate fillers, the major portion of which is iron powder, 5 to 15 weight percent of short (<250 .mu.m) glass fibers, and 0.02 to 1 weight percent of a surface active agent.

Abstract: A semiconductor device encapsulant contains (a) a thermosetting resin for providing a cured product having a glass transition temperature of not less than 190.degree. C., (b) a filler consisting of a fused silica, (c) a modifier consisting of an MBS or ABS, (d) a modifier consisting of a silicone rubber or a silicone gel, and (e) a lubricant containing a metal chelate compound.

Abstract: An adhesive composition comprising (a) an epoxy resin obtained by reacting a 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubustituted disiloxane dianhydride with an alcohol or alcohol derivative, followed by reaction with an epoxy compound having two or more epoxy groups, or an epoxy resin obtained by reacting a 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane with an epoxy compound having two or more epoxy groups and (b) a curing agent is suitable for bonding semiconductor chips to a copper frame with a small warpage of the chips.

Abstract: A flame retardant resin composition comprising (A) 70 to 10% by weight of a rubber-reinforced styrene base resin, (B) 20 to 85% by weight of a polycarbonate resin, (C) 5 to 35% by weight of a high molecular weight halogen-containing compound of the formula: ##STR1## wherein n is an average polymerization degree and an integer of 4 to 30, R and R' are independently a hydrogen atom, a methyl group, an epoxypropyl group, a phenyl group, a halogenated phenyl group or a group of the formula: wherein m is an integer of 0 to 3, which compound has a bromine content of at least 45% by weight and an epoxy equivalent of at least 10,000 g/mol, and (D) 0 to 10% by weight of an antimony compound, which resin composition is excellent not only in heat stability but also in heat resistance, impact resistance, processability and light resistance.

Abstract: A composition comprising (A) an epoxy resin having at least two epoxy groups in a molecule, (B) a silicone-modified epoxy resin, (C) an imidazole curing agent having a solubility of up to 0.1% by weight in epoxy resin (A) at 25.degree. C., and (D) fused silica having a mean particle size of up to 10 .mu.m and adjusted to a viscosity of up to about 4,000 poise at 25.degree. C. satisfies the requirements for flip chip encapsulation since the composition has improved shelf stability and filling ability and cures into products having improved moisture resistance. Semiconductor devices encapsulated with cured products of the composition remain reliable because of moisture resistance.

Abstract: A process for producing as end-product a heat-hardenable mixture forming thermosetting resin, e.g., a reactive hot-melt adhesive, comprises preparing a first pre-mixture by introducing a meltable heat-hardenable solid resin and liquid resin, flexibilizer, adhesion-promoter and/or plasticizer into a mixing zone in which the components are melted together; preparing a second pre-mixture by mixing with each other a heat-activatable hardener and thixotropic agent, hardening accelerator and/or electrical conductivity-imparting additive; introducing the melt into an extruding zone; and introducing the pulverulent pre-mixture into the extruding zone downstream of the melt-intake for mixing with the first pre-mixture at a temperature below said hardening temperature and in such amount that the content of the second pre-mixture in the end-product ranges from 10 to 50, preferably from 20 to 30 weight-% air occlusions in the melt and the extruded end-product being avoided.

Abstract: A polymer composition especially suitable for producing fibre-reinforced structures having advantageous fracture toughness comprises a polyarylsulphone component and a thermoset resin component, each of which components is present at least partly as a phase continuous in at least one dimension. Preferred polyarylsulphones contain repeating units (PhSO.sub.2 Ph).sub.n and (Ph).sub.a linked through ether and/or thioether, where Ph is phenylene, n=1 to 2 and a=1 to 3; and such polyarylsulphones having amino end groups are provided as new compounds. The compositions can be made by spinodal decomposition of a mixture of the polyarylsulphone and a thermoset resin precursor.

Abstract: Disclosed herein are electronic device sealing resin compositions containing 100 parts by weight of a thermoplastic resin mixture composed of 25-60 wt. % of a poly(arylene sulfide) and 40-75 wt. % of an inorganic filler; and 1.5-5 parts by weight of an epoxy-modified silicone oil having an epoxy equivalent of 350-1,000 g/eqiv. Also disclosed are electronic devices sealed using such resin compositions.

Abstract: Disclosed is a hardening agent composition for epoxy resins in the form of powdery grains, comprising a low-reactive hardening agent, a hardening promoter, a zeolite and at least one additive selected from a water-repellent fine silica powder, a silane coupling agent and a polysiloxane compound, whereby the additive is adhered to the surfaces of the powdery grains. The composition has a retarded water-absorbing property and has improved storage stability, when blended with an epoxy resin to form a thermosetting epoxy resin composition. Methods for preparing the powdery hardening agent composition are also disclosed.

Abstract: This invention is directed to a setting resin composition comprising (A) a radically polymerizable monomer, (B) a thermoplastic resin soluble or dispersible in said monomer (A), (C) an epoxy resin, (D) at least one polyfunctional carboxylic acid compound selected from said group consisting of polyfunctional carboxylic acids and anhydrides thereof, and (E) an inorganic filler and using said components in proportions such that, based on said amount of said radically polymerizable monomer (A) taken as 100 parts by weight, the amount of said thermoplastic resin (B) is in the range of 5 to 75 parts by weight, that of said epoxy resin (C) in the range of 10 to 100 parts by weight, that of said inorganic filler (E) in the range of 100 to 1,000 parts by weight, and that of said polyfunctional carboxylic acid compound (D) in the range of 0.5 to 4.

Abstract: An epoxy resin composition comprising an epoxy resin, a curing agent, and a copolymer mixture comprising a long-chain organopolysiloxane copolymer [I] and a short-chain organopolysiloxane copolymer [II] which are each prepared by the addition reaction of an alkenyl-containing epoxy resin with a long-chain or short-chain organopolysiloxane containing pendant phenyl groups at a weight ratio of [II] to [I] of 0.3 to 0.6 is disclosed. The epoxy resin composition exhibits excellent printability, crack resistance, and moldability properties.

Abstract: Heat cured, thermoset protective surface coating films applied to a substrate are produced preferably by a dual cure of a polymeric ionomeric binder comprising zinc modified carboxyl functional epoxy-ester polymers. The epoxy-ester polymer contains both carboxy and hydroxyl functionality and coreacts with a zinc salt selected from a zinc carbonate or an organic zinc salt having a pKa above about 3.0. Upon heat curing, the carboxyl and hydroxyl groups crosslink while the zinc forms a zinc cluster to produce a thermoset film.

Abstract: An epoxy resin composition for semiconductor sealing, comprising as essential components:(A) an epoxy resin,(B) a phenolic resin curing agent comprising 30-100% by weight, based on the total amount of the phenolic resin curing agent, of a silicone-modified phenolic resin curing agent obtained by reacting a phenolic resin with at least one of silicone compounds represented by the following formulas [I] and [II] ##STR1## wherein ##STR2## A: --R--COOH, ##STR3## or H, R: a lower alkylene group,10.ltoreq.N=l+m+n+2.ltoreq.200,0.ltoreq.m/N.ltoreq.0.1, and 5.ltoreq.N/n.ltoreq.50,(C) an inorganic filler, and(D) a curing accelerator.

Abstract: A resin composition for sealing semiconductors which comprises (a) a modified epoxy resin composed of (i) an epoxy resin having a specific structure or a graft polymer of an epoxy resin having a specific structure and a vinyl polymer and (ii) a silicone polymer in oily state or as particles having an average particle size of not more than 1.0 micron, which are uniformly dispersed in the epoxy resin or the graft polymer, (b) a hardening agent and (c) an inorganic filler, is herein provided. The resin composition for sealing semiconductors exhibits a low thermal expansion coefficient and a low elastic modulus, generates low stress when thermal shock is applied thereto and exhibits high heat resistance during soldering even after moisture absorption. Therefore, if the composition is used to seal large-scale semiconductor devices having high degree of integration or small-sized, thin semiconductors such as flat packages, these semiconductors provide high reliability.

Abstract: Disclosed herein is an epoxy resin composition for sealing a semiconductor, which contains a flexibilizer, epoxy resin, a hardener, a hardening accelerator, a filler, a mold releasing agent, a colorant and a finishing agent. The flexibilizer is prepared from silicone containing hydroxyphenyl groups on ends of and/or in its molecules, which is formed of a copolymer of denatured silicone oil A having hydroxyphenyl groups, denatured silicone oil B having epoxy groups and/or bifunctional epoxy resin having epoxy groups on both ends.In addition to heat resistance, moisture resistance, a low elastic modulus, a low thermal expansion coefficient and a high glass-transition temperature, the epoxy resin composition according to the present invention has toughness which is higher than that of a conventional one, due to fine dispersion of silicone.

Abstract: An epoxy resin composition comprising an epoxy resin, a curing agent, a substantially pure alpha-alumina filler, and a silicone-modified epoxy or phenol resin is useful in encapsulating semiconductor devices. The composition can be molded and cured into a product having improved thermal conductivity and moisture resistance.

Abstract: An encapsulant consisting of an epoxy resin composition and suitably used to encapsulate a semiconductor device which is to be surface-mounted contains(a) an epoxy resin,(b) a rubber-modified phenolic resin comprising a phenolic resin, and a methylmethacrylate-butadiene-styrene copolymer and a thermosetting silicon rubber dispersed in said phenolic resin,(c) a curing accelerator, and(d) a silica powder.

Abstract: This invention discloses curable silicon compositions which impart beneficial characteristics to the fibers that are not possible without the use of the instant invention compositions and process.

Abstract: An epoxy resin composition which comprises a curable epoxy resin, a curing agent, an inorganic filler, and at least one copolymer selected from copolymers obtained by an addition reaction between aromatic polymers containing one or more epoxy groups and one or more alkenyl groups and the specific organopolysiloxanes; copolymers obtained by an addition reaction between aromatic polymers containing one or more epoxy groups and the specific amino group-containing organopolysiloxanes.

Abstract: Glass fiber reinforced polyethylene terephthalate molding resin blends are provided which crystallize rapidly after being injection molded and which have engineering resin performance characteristics. In addition to polyethylene terephthalate and glass fibers, the blends contain an aliphatic polyester, an ionic hydrocarbon polymer, an antioxidant, and, optionally, polythylene and/or a polymeric epoxy compound. The blends can be flame retarded with a brominated polystyrene and an antimonate without substantial loss of, or change in, properties.

Abstract: Disclosed are epoxy resin compositions comprising essentially (A) multi-functional epoxy resins, (B) imide-modified silicone compounds, (C) phenolic novolaks having more than 2 OH groups, and (D) inorganic fillers. When cured, these compositions have excellent processability and lower internal stress as compared to a similar composition without the imide-modified silicone compounds. These compositions are useful for sealing semiconductor devices or other molding applications.

Abstract: A semiconductor sealing epoxy resin composition includes a flexibilizer which is a previous reactant between a denatured silicone oil having epoxy groups and a phenol novolak resin, a novolak type of epoxy resin, a hardening agent, an accelerator, a filler, a die lubricant, and a surface treatment agent. This composition has a heat and moisture resistance needs for a semiconductor sealing material, and as well as a low elastic modulus.

Abstract: Heat cured, thermoset protective surface coating films applied to a substrate are produced preferably by a dual cure of a polymeric ionomeric binder comprising zinc modified carboxyl functional epoxy-ester polymers. The epoxy-ester polymer contains both carboxy and hydroxyl functionality and coreacts with a zinc salt selected from a zinc carbonate or an organic zinc salt having a pKa above about 3.0. Upon heat curing, the carboxyl and hydroxyl groups crosslink while the zinc forms a zinc cluster to produce a thermoset film.

Abstract: Epoxy resins which have silicon-containing functional groups along the polymer backbone are prepared by reacting a polyether having non-terminal hydroxy groups with a modifying agent which (i) reacts with hydroxy groups and (ii) which also contains trialkoxysilane groups. The modified resins can be reacted with a silicon oxide precursor to form an organic/inorganic composite. The composites are shown to have improved properties at elevated temperatures.

Abstract: A resin composition for sealing semiconductors which comprises (a) an epoxy resin, (b) a hardening agent, (c) an inorganic filler and (d) a polymaleimide having a specific structure is herein provided. Preferably, the resin composition comprises, as all of or a part of the epoxy resin, a modified epoxy resin composed of (i) a graft polymer of an epoxy resin and a vinyl polymer and (ii) a silicone polymer in an oily state or as particles having an average particle size of not more than 1.0 micron, which are uniformly dispersed in the graft polymer. The resin composition for sealing semiconductors exhibits a low thermal expansion coefficient and a low elastic modulus, generates low stress when thermal shock is applied thereto and exhibits high heat resistance during soldering even after moisture absorption.

Abstract: An epoxy fluorocarbon coating composition in the presence of a curing agent and, wherein the fluorocarbon polymer is about 5 to about 24 percent of the total weight of the coating composition and has a particle size less than 500 microns which has excellent corrosion resistance.

Abstract: A novel thermoplastic resin composition is here disclosed which contains (I) 99 to 1% by weight of a polysulfone or polyether sulfone; (II) 1 to 99% by weight of an acrylonitrile-butadiene-styrene resin; (III) 0.1 to 100 parts by weight, based on 100 parts by weight of the aforesaid resin (I)+(II), of a multi-phase structure thermoplastic resin which is composed of 5 to 95% by weight of an epoxy group-containing olefin copolymer and 95 to 5% by weight of a vinyl polymer or copolymer obtained from at least one kind of vinyl monomer, either of the polymer or copolymer being in the state of a dispersion phase having a particle diameter of 0.001 to 10 .mu.m; and (IV) 0 to 150 parts of an inorganic filler.Furthermore, a method for preparing the aforesaid composition is also disclosed.

Abstract: A chlorosulfonated ethylene.multidot..alpha.-olefin copolymer composition is disclosed, comprising(a) 100 parts by weight of a chlorosufonated ethylene.multidot..alpha.-olefin copolymer containing from 25 to 32% by weight chlorine and from 0.3 to 2.5% by weight sulfur,(b) from 1 to 4 parts by weight of a metal oxide or a metal hydroxide,(c) from 3 to 15 parts by weight of an epoxy compound,(d) from 0.5 to 5 parts by weight of a thiuram, and(e) from 0.5 to 5 parts by weight of a maleimide. The chlorosulfonated ethylene.multidot..alpha.-olefin copolymer of the invention provides vulcanized products having excellent heat resistance, cold resistance and water resistance.

Abstract: The flameproofing agent content of molding compositions containing polyesters (a.sub.1), acrylate graft polymers (a.sub.2), styrene/acrylonitrile copolymers (a.sub.3) and glass fibers can be reduced without affecting the flame resistance by adding finely divided PTFE.

Abstract: Thermoplastic molding composition based on thermoplastic polyesters (a.sub.1), graft polymers incorporating acrylate rubbers as grafting base (a.sub.2), copolymers of aromatic vinyl monomers and acrylonitrile or methacrylonitrile (a.sub.3) and glass fibers (B) have particularly good mechanical properties if the (meth)acrylonitrile content in component (a.sub.3), based on the total weight of (a.sub.3), is less than the (meth)acrylonitrile content of component (a.sub.22).

Abstract: Thermoplastic molding compositions based on thermoplastic polyesters (a.sub.1), graft polymers incorporating acrylate rubbers as grafting bases (a.sub.2), copolymers of aromatic vinyl monomers and acrylonitrile or methacrylonitrile (a.sub.3) which contain a polymeric component (B) having carboxyl, carboxyl derivative, hydroxyl or epoxy groups or, alternatively, where graft polymers (a.sub.2) or copolymers (a.sub.3) carry such groups have a balanced range of properties.

Abstract: A resin composition comprising (a) 100 parts by weight of a block copolymer composed of polyphenylene sulfide segments and polyphenylene sulfide sulfone segments and (b) 0.01 to 20 parts by weight of at least one compound selected from the group consisting of epoxy resins, maleimide compounds, N,N'-diarylcarbodiimide compounds and organosilane compounds and as required, (c) an organic filler.

Abstract: An epoxy resin composition consisting essentially of(A) an epoxy resin,(B) a curing agent,(C) a curing promoter,(D) an organic silicon compound having at least one phenolic hydroxyl group per molecule, and(E) a filler.

Abstract: A resin composition comprising a nylon-4,6 resin, an epoxy compound having two epoxy groups and at least one polymer selected from halogenated polystyrenes and halogenated poly-alpha-methylstyrenes, represented by the following general formula (I) ##STR1## (wherein R is a hydrogen atom or a methyl group; X is a bromine or chlorine atom; p is an integer of 1 to 5; and n is an integer of 2 or more).

Abstract: A semiconductor sealing resin composition which comprises (a) a modified epoxy resin which is a graft copolymer of a epoxy resin and a vinyl polymer having dispersed therein a silicone rubber with an average particle diameter less than 1.0.mu.; (b) a curing agent; and (c) an inorganic filler. The sealing composition has a low elastic modulus, a low heat expansion coefficient, a high resistance to heat and a high resistance to thermal expansion.

Abstract: The present invention provides a novel epoxy resin-based curable composition suitable for use as an encapsulating resin composition for semiconductor devices capable of being highly resistant against crack formation with low internal stress by curing and yet having very high heat conductivity and maintaining high glass transition temperature. The inventive composition comprises (a) 100 parts by weight of a curable epoxy resin blend which is a mixture of an epoxy resin and a curing agent therefor, (b) from 5 to 100 parts by weight of a block copolymer composed of at least one segment of an aromatic polymeric moiety, phenyl novolac, and at least one segment of an organopolysiloxane moiety having 30 to 200 silicon atoms and bonded to the aromatic polymeric moiety through a carbon-to-silicon linkage, and optionally (c) an inorganic filler which is preferably a silica filler such as powdered quartz in an amount not exceeding 1000 parts by weight.

Abstract: A fiber reinforced composite structure having a glass transition temperature greater than 150.degree. C. is comprised of:a) reinforcing fiber andb) a curable epoxy resin composition comprising(i) one or more epoxides having more than one epoxide group per molecule, of which epoxides at least 10 percent by weight is a 9,9-bis[4-(2,3-epoxypropoxy)phenyl]fluorene, all of the fluorene epoxy present being free of ortho substitution;(ii) an effective amount of one or more epoxy curing agents.

Abstract: An epoxy resin composition which comprises a curable epoxy resin, a curing agent, an inorganic filler, and at least one copolymer selected from copolymers obtained by an addition reaction between aromatic polymers containing one or more epoxy groups and one or more alkenyl groups and the specific organopolysiloxanes; copolymers obtained by an addition reaction between aromatic polymers containing one or more epoxy groups and the specific amino group-containing organopolysiloxanes.

Abstract: An epoxy resin composition which is adapted for use as an encapsulator of electronic or electric parts and which comprises an epoxy resin and a curing agent for the epoxy resin. A modified polymer obtained by reaction between an aromatic polymer and a fluorine-containing material is added to the epoxy resin, so that good characteristic properties are imparted to the resultant cured product.

Abstract: An epoxy resin composition which comprises a curable epoxy resin, a hardener, and a block copolymer formed by the reaction of a triphenol-alkane type resin or a polymer thereof with a specific organopoly-siloxane. The composition provides a cured product having a high glass transition point, a low coefficient of expansion, good crack resistance, and is less likely to exert stress to the semiconductor devices. It exhibits distinct characteristics when used as a sealing compound for semiconductor devices, especially in the case where the element is bonded directly to a printed circuit board or heat sink. It is very unlikely that a semiconductor device sealed with it would become warped.