MXPA01006495A - Electronic circuit device comprising an epoxy-modified aromatic vinyl-conjugated diene block copolymer - Google Patents

Abstract

An elecronic circuit device comprises a resin composition including 90 to 100 weight percent of a curable epoxy-modified aromatic vinyl-conjugated diene block copolymer, optionally up to 10 weight percent of an epoxy resin, and an effective amount of an epoxy curative, the weight percent of the copolymer and epoxy resin being based on the weight of the epoxy bearing material exclusive of curative. The resin composition can be used as an electronic adhesive, covercoat, or encapsulant. The electronic circuit device exhibits superior heat and moisture insensitivity, including the absence of voiding and delamination of the cured resin composition from its substrate under conditions of 85°C and 85%relative humidity for 168 hours followed by a temperature of 220°C for 10 to 40 seconds.

Description

ELECTRONIC CIRCUIT DEVICE COMPRISING UN- COPOLYMER OF DIAMOND BLOCKS CONJUGATED WITH AROMATIC VINYL MODIFIED WITH AN EPOXY Field of the Invention The invention relates to a device with an electronic circuit comprising a copolymer of diene blocks conjugated with aromatic vinyl, modified with epoxy. The copolymer can be included in a resin composition that can be used as for example, an adhesive, a protective cover layer, or an encapsulant. BACKGROUND OF THE INVENTION A main trend in the electronics industry is to produce small, light and fast products while maintaining or improving their functionality. One of the key technologies that is allowing the creation of more and more compact products is the technology of electronic packages and assemblies. Electronic assembly and packaging constitute the materials and processes required to interconnect a semiconductor microcircuit (chip or microcircuit IC) to other electronic or electrical components. In addition to the semiconductor chip or microcircuit, various materials can be incorporated into REF: 130418 an electronic package or package, such as a system of flexible electrical circuits (metal circuit system in polyimide or other polymer films), metal reinforcements, electrically conductive layers, electrically insulating layers, and heat sinks. Adhesives are frequently used to adhere several of these substrates at the same time and to adhere at the same time multiple layers of circuit systems or circuitry in substrates to form multi-layer electronic structures having an increased wiring density such as that required by modules. of multiple chips or microcircuits. The coverings and encapsulation are necessary to protect the circuitry of the rigorous environment that can be observed in the request of the products. The electrical connection of these packages to printed circuit boards or other electronic components requires that the packages or packages undergo a weld reflow, which can expose the package at temperatures of 220 ° C for tenths of seconds to minutes. This process has proven to be quite demanding in adhesives and coatings or coverings, causing faults in the product such as the formation of voids and / or delamination of the different substrates. "Crack formation" is the generic term coined for these faults. The presence of moisture in the packing followed by rapid heating to the reflow temperatures of the weld promotes "cracking". Moisture is absorbed by various organic substrates such as polyimide films and organic adhesives, and can absorb metals and inorganic components. The standard of the joint industry, "Moisture / Reflow Sensitivity Classification for Plastic Integrated Circuit Surface Mount Devices". October 1996. J-STD-020, developed by the Board of Electronic Devices Engineering Board (JEDEC) of the Electronic Industries Association and the Interconnects and Electronic Packaging Circuits Institute, is the industry standard of The electronics to test the resistance of the welding of the packages or packages after exposure to moisture. Materials of standard grades by levels and level 1 of JEDEC (85 ° C / 85% R.H. for 168 hours followed by welding reflow at a peak temperature of 220 ° C for 10 to 40 seconds) is the most required test. Packages that pass level 1 JEDEC have the highest degree of weld strength, and do not need to be packaged to protect them from the humidity of the environment. The failure in level 1, but the step to less demanding levels, requires a protective packaging. The current state of the art in the development of adhesives allows the realization of level 3 of JEDEC (30 ° C / 60% RH for 192 hours followed by welding reflow at a maximum temperature of 220 ° C) and a very limited number of adhesives claim successful operation of JEDEC level 2 (85 ° C / 60% RH for 168 hours followed by the reflow of welding at a maximum temperature of 220 ° C). Specific polyimides can approve JEDEC level 1, but these materials require extremely high lamination temperatures of approximately 350 ° C. Such lamination temperatures prohibit the use of polyimides in packages or packages containing materials that will decompose or alter at these elevated temperatures, such as organic coating layers, welding masks, welding, etc. Polyimides can be used in cases where all the materials present in the package during the rolling time can withstand the high rolling temperatures. However, these high temperatures cause the process to be difficult and expensive.

Epoxidized styrene-diene block copolymers such as epoxidized styrene-isoprene or epoxidized styrene-butadiene block copolymers have been described in U.S. Patent No. 5,478,885. In some applications, the epoxidized block copolymers have been used as rubber hardening agents for commonly used epoxy resins. Typically, hardening agents constitute a small percentage of the total composition. Cured compositions comprising epoxy resins and epoxy-modified diene-conjugated diene block copolymers have been described in EP658603. The compositions may contain from 5 to 95 parts by weight of an epoxy resin, preferably from 20 to 80 parts by weight. When the composition contains less than 5 parts by weight of any component, losses of mechanical properties occur. The use of these materials in electronic packaging applications is not suggested. It has been shown that the crosslinking of the epoxidized styrene-diene block copolymers through the main chain epoxy groups produces adhesive compositions for use in, for example, pressure sensitive adhesive tapes, labels, waterproofing, and coatings. as described in U.S. Patent No. 5,229,464 and WO 97/30101. The adhesives can be formulated to include reactive diluents, including epoxy resins, in the amount of from 1 to 50% by weight of the total composition. The use of these materials in electronic packaging applications is not suggested. In WO 98/22531, compositions comprising cured, epoxidized styrene-diene block copolymers useful as multilayer molding materials have been described. The compositions can be cured by a wide variety of known epoxy curing agents. Also described are compositions that additionally comprise the addition of polyfunctional co-reactants in amounts in the order of 0.01 to 25 parts by weight. Epoxy resins are not described as co-reactive. The use of these materials in electronic packaging applications is not suggested. EP 387066 discloses useful adhesives in electronic packaging comprising liquid epoxy resins and a functionalised resin addition (see also US 5,843,251). To extend the shelf life of the adhesives, a curing agent of the microcapsule type in the formulation is required. The functionalized styrene-diene block copolymers are among the so-called functionalized resins and are not exemplified, wherein the functional group can be an epoxy group. The functionalized resin added can be present in the amount of 20 to 80% by weight. The adhesives can be processed into adhesive tapes that can be used to electrically connect circuits in chips or microcircuits and wiring substrates. The operation of the adhesives under conditions of level 1 of JEDEC is not described. Hot melt adhesives crosslinkable with amine, useful in electronic applications, comprising a polyolefin having an epoxy group in its molecule, has been described for example in WO 96/33248, where a curative aromatic amine is required and the composition optionally comprises an epoxy resin. The mentioned polyolefins are copolymers of ethylene and a monomer containing a glycidyl (meth) acrylate group, so that the epoxy groups depend on the polymer backbone. Epoxy modified conjugated diene block copolymers with epoxy are not suggested. When present, the amount of epoxy resin added is about 5 to about 200 parts by weight per 100 parts of the polyolefin copolymer. The adhesives were used for electronic systems but their use is not suggested under JEDEC level 1 conditions.

BRIEF DESCRIPTION OF THE INVENTION Briefly, the invention provides an electronic circuit device comprising a resin composition including a block copolymer of aromatic vinyl conjugated diene blocks, modified with epoxy present in the range of 90 to 100 percent in weight-of the weight of the exclusive curative epoxy-containing material, optionally up to 10 weight percent of an epoxy resin based on the weight of the epoxy-containing material, and an effective amount of a curative epoxy. After curing with one or both of heat (i.e., a temperature of up to about 250 ° C) and UV radiation, the composition of the copolymer resin and the adjacent substrate (s) exhibit superior solder or heat resistance and insensitivity to moisture. In particular, the composition of the cured resin is stable (ie, there is no vacuum or division delamination of the substrate (s)) after exposure to conditions of 85 ° C and 85% relative humidity (RH) for 168 hours followed by rapid heating at a temperature of 220 ° C for 10 to 40 seconds. In another aspect, the invention provides a method of using a curable resin composition in an article comprising the steps of: providing a curable resin composition on at least one surface of a substrate, said resin composition including in the range of 90 to 100 weight percent of an epoxy-modified aromatic vinyl-conjugated diene block copolymer, optionally up to 10 weight percent of an epoxy resin, the weight of both components based on the weight of both components based on the weight of materials having epoxy, and an effective amount of a curative epoxy, and incorporating said resin composition as an adhesive, coating layer, or encapsulant into an article, which preferably can be an electronic circuit device. The composition of the resin may be a layer or it may be in the form of a bulk or mass.

After curing the copolymer with one or both of heat and UV radiation the resin composition of the cured copolymers exhibits superior solder resistance and moisture insensitivity, as defined above. The resin composition of the cured copolymer can be an adhesive, an encapsulant, or it can be a protective covering coating for an electronic circuit device. Examples of the use of the adhesive in electronic circuit devices include: the adhesion of a flexible circuit layer to another layer of flexible circuitry or to a metal reinforcement or to a microcircuit or semiconductor chip: adhesion of copper or other metal foil to a polymer substrate; and adhesion of an electronic component such as a semiconductor chip or microcircuit to a circuit in a substrate. The adhesive can be insulating or can be made electroconductive by the addition of electroconductive particles. In this application: "electronic circuit" means the path of an electric current or of electrons that includes such elements as electrical conductors, for example, metallic cables or metal traces, and electronic components such as semiconductor chips, transistors, diodes, capacitors , resistors, inductors, etc.; "electronic circuit device" means a device comprising an electronic circuit or electronic component, such as (1) an electronic package such as a grouped grid arrangement (BGA), a laminated micro-interconnector (LMI), a multiple microcircuit module, or a chip-scale or microcircuit (CSP) package, (2) simple flexible circuitry wherein the sheet or sheet of copper adheres to a polymer substrate with an adhesive, or (3) an electronic component such as a semiconductor chip connected to a circuit or a substrate; "material that has epoxy" means a conjugated diene with aromatic vinyl, modified with epoxy, plus epoxy resin, if present; "Welding strength" means resistance to heat at the reflow temperature of the weld; "Welding composition" means a material that has more epoxy, a catalyst or curative; and "epoxy-modified aromatic vinyl-conjugated diene block copolymer" includes such copolymers that are partially hydrogenated prior or subsequent to modification with epoxy. The present invention is advantageous because the composition of the copolymer resin provides superior weld strength and moisture insensitivity and uses lamination temperatures (eg 220CC) much lower than those required for conventional polyimide-based materials. (for example, 350 ° C). Additionally, the resin composition of the copolymer has excellent peel strength (50 to 325 Ne tons / dm) to the Kapton ™ polyimide film (Du Pont), and provides over 1000 hours of yield 85 ° C / 85 R.H. with a deviation of 5 volts in an interdigitalized copper test circuit that had been laminated with the copolymer. The composition of the copolymer resin also shows no ink absorption in the ink jet by visual observation after immersion for 11 days at room temperature. The composition of the copolymer resin also has excellent resistance to corrosion, alkaline environmental conditions and / or aqueous acids. Additionally, conventional adhesives and coating layers in the packages are known to exhibit moisture induced faults under welding reflow conditions. The resin composition of the copolymer of the present invention of the present invention does not exhibit moisture induced failure under reflow conditions of the weld. Brief description of the drawings Figure 1 shows a diagram or graph of the shear modulus vs. the temperature for a preferred composition of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The adhesive, the encapsulant or the resin composition of the coating layer copolymer of the electronic circuit device of the present invention comprises in the range of 90 to 100 weight percent the diene block copolymer conjugated to aromatic vinyl, modified with epoxy, wherein the block copolymer can also be hydrogenated in the range of 10 to 0 weight percent based on the epoxy resin on the weight of the epoxy-bearing material in the resin composition, and an epoxy or curative catalyst in an amount in the range of 0.01 to 5.00 weight percent, based on the total weight of the material having epoxy. The epoxy-modified aromatic vinyl-conjugated diene block copolymer preferably has an epoxy equivalent weight in the range of 100 to 2500, more preferably from 100 to 2000, and more preferably from 200 to 1000. The epoxy-modified aromatic vinyl-conjugated diene block copolymer, which is preferably an epoxidized diene-styrene block copolymer, comprises (i) a polymer block derived from the polymerization of an aromatic vinyl moiety and (ii) a polymer block derived from the polymerization of at least one monomer having conjugated double bonds, wherein the double bonds of the polymer backbone are at least partially epoxidized, as essential portions of the chemical structure. The block copolymer is preferably free of pendant epoxy groups. In the epoxy-modified aromatic vinyl-conjugated diene block copolymer, the vinyl aromatic polymer block can be derived from the polymerization of compounds such as, for example, styrene, alpha-methylstyrene, vinyl toluene, p-tert-butylstyrene, divinylbenzene, p-methylstyrene, 4-n-propylstyrene, 2,4-dimethylstyrene, 3,5-diethylstyrene, 1,1-diphenyl styrene, 2,4,6-trimethyl styrene, 4-cyclohexylstyrene, 3-methyl-5 -n-hexyl styrene, and the like. Although one or more of the vinyl aromatic compounds may be used, styrene is frequently and preferably used. In the epoxy-modified aromatic vinyl-conjugated diene block copolymer, the double bonds in the main chain can be derived from the polymerization of the compounds having conjugated double bonds such as, for example, butadiene, isoprene, 1,3-pentadiene , 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-l, 3-octadiene, 1-phenyl-1,3-butadiene, 1,3-octadiene, 4-ethyl-l, 3-hexadiene , and similar. However, one or more compounds having a conjugated double bond can be used, butadiene, isoprene, piperylene and mixtures thereof are frequently and preferably used. The block copolymer in the present invention essentially includes a block of polymer A derived from one or more vinyl aromatic compounds and a block of polymer B derived from one or more of the compounds having a double conjugated bond. The weight ratio of the copolymerization of the aromatic vinyl compound to the compound having a conjugated double bond is generally from 5/95 to 70/30, preferably from 10/90 to 60/40. The number average molecular weight of the block copolymer useful in the present invention is generally from 5,000 to 600,000, preferably from 10,000 to 500,000 and the molecular weight distribution (the proportion (Mw / Mn) of a weight average molecular weight (Mw) at a number average molecular weight (Mn)) is less than 10. The molecular structure of the block copolymer useful in the present invention can be any of the radial, branched types and linear and any combination thereof. The epoxidized styrene-diene block copolymer can be represented by the general configurations, for example of (A-B) XA. (B-A) x y (A-B) 4 Si and the like, where A and B are as defined above and x is the number of groups A-B in the polymer. In the copolymers, type (A-B) XA is generally used.

The excess unsaturated bonds in the block copolymer can be partially or completely hydrogenated. Alternatively, the partial hydrogenation may precede the epoxidation. Preferred epoxidized copolymers include epoxidized non-hydrogenated styrene-butadiene block copolymers (e.g., Epofriend ™ A1020, A1010, and 10.05, Daicel Chemical Industries LTD, Osaka, Japan). It is anticipated that the epoxidized styrene-butadiene block copolymer will be useful in the present invention due to the improved oxidative stability. Another preferred epoxidized styrene-diene copolymer that can be used in the adhesive, coating layer, or encapsulant of the invention includes an epoxidized styrene-isoprene block copolymer. Epoxy resins that can be mixed and subsequently reacted with the epoxy modified conjugated diene-conjugated vinyl diene block copolymer include up to 10 weight percent, preferably 0 to 5 weight percent, more preferably 0 to 3 percent by weight, of an aromatic or aliphatic epoxy resin based on the total weight of epoxy-bearing materials.

Epoxy resins useful in the adhesive, encapsulants or coating resin compositions of the invention preferably comprise compounds containing one or more 1,2-, 1,3- and 1,4-cyclic ethers, which may also be known as 1,2-, 1,3- and 1,4-epoxides. Preferred are 1,2-cyclic ethers. Such compounds may be saturated and unsaturated, alicyclic, aromatic or heterocyclic aliphatics, or may comprise combinations thereof. Preferred are compounds that contain more than one epoxy group (i.e., polyepoxides). Aromatic polyepoxides (ie, compounds containing at least one aromatic ring structure, for example, a benzene ring, and more than one epoxy group) that can be used in the present invention include the polyglycidyl ethers of polyhydric phenols, such as Bisphenol type A resins and their derivatives, cresol-novolac epoxy resins, Bisphenol-F resins and their derivatives, and novolac-phenol epoxy resins; and glycidyl esters of aromatic carboxylic acids, for example, diglycyl ester of phthalic acid, diglycyl ester of isophthalic acid, trimethyl anhydride triglyceryl ester, and tetraglycidyl ester of pyromellitic acid, and mixtures thereof. Preferred aromatic polyepoxides are the polyglycidyl ethers of polyhydric phenols, such as those of the EPON ™ series of glycidyl ethers of Bisphenol-A, including EPON 828 and EPON 1001F, commercially available from Shell Chemicals, Inc., Houston, TX. . Also preferred are aromatic polyepoxides having low levels of hydrolysable chloride, such as EPON 828 LS, EPON 1462 (Shell Chemicals, Inc.) and DER ™ 332 (Dow Chemical Co., Midland, MI). Representative aliphatic cyclic polyepoxides (i.e., cyclic compounds containing one or more saturated carbocyclic rings and more than one epoxy group, also known as alicyclic compounds) useful in the present invention include the ERL ™ series of commercially available alicyclic epoxides. Union Carbide Corp., Danbury, CT, such as vinyl cyclohexane dioxide (ERL-4026), 3-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate (ERL-4221), 3,4-epoxy-6-methylcyclohexylmethyl carboxylate -3, 4-epoxy-6-methylcyclohexane carboxylate (ERL-4201), bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate (ERL-4289), dipentene dioxide (ERL-4269), as well as 2- ( 3, -epoxycyclohexyl) -5,1"-spiro-3", 4"-epoxycyclohexane-1,3-dioxane, 4- (1, 2-epoxyethyl) -1,2-epoxycyclohexane and 2,2-bis (3,4-epoxycyclohexyl) propane The preferred alicyclic polyepoxides are the ERL ™ series, the representative aliphatic polyepoxides ( to say, compounds that do not contain carbocyclic rings and more than one epoxy group) include 1,4-bis (2, 3-epoxypropoxy) butane, polyglycidyl ethers of aliphatic polyols such as glycerol, polypropylene glycol, 1,4-butanediol, and the like, and di-linoleic acid ester. Also useful are epoxidized vegetable oils such as soybean oil and linseed available as Vikoflex ™ resins and monoepoxides such as the epoxidized alpha-olefins available as Vikolox ™ resins, both of which are available from Elf Atochem North America Inc., Philadelphia, PA, and epoxidized Kraton ™ liquid polymers such as L-207 ™ available from Shell Chemical Co., Houston TX. Additionally polyepoxides useful in the present invention include epoxidized, liquid conjugated dienes such as Poly bd ™ 600 and Poly bd 605, commercially available from Shell Chemical Co., Houston TX.

Additional polyepoxides useful in the present invention include liquid epoxidized conjugated dienes such as Poly bd ™ 600 and poly bd 605 commercially available from Elf Atochem North America Inc. A wide variety of commercial epoxy resins are available and are listed or described in for example . , the Handbook of Epoxy Resins, by Lee and Neville, McGraw-Hill Book Co., New York (1967). Epoxy Resins Chemistry and Technology, Second Edition. C. May. Ed., Marcell Decker, Inc., New York (1988), and Epoxy Resin Technology P.F. Bruins, ed. , Interscience Publishers, New York, (1968). Any of the epoxy resins described herein may be useful in the preparation of the materials of the present invention. Suitable catalysts or curatives will desirably tolerate the steps of solution or melt processing, according to the present invention without the substantial curing of the epoxy component, while retaining the ability to cure the epoxy component at a later time under the influence of heat or light. For example, the epoxy must remain substantially uncured during and after exposure to the temperature present in a step of the melting process. Other factors that influence the selection of the catalyst include the thickness of the film to be cured, transparency of the film to cure the radiation, and the final use of the films. The object of these limitations, suitable curatives can be selected from any of the known epoxy catalysts or curatives. The curatives of the present invention may be photocatalysts, thermal catalysts, or thermal curing agents. Known photocatalysts include two general types: onium salts and cationic organometallic salts, both of which are useful in the invention. The photocatalysis of the onium salt for the cationic polymerizations of the invention include complex iodine and sulfonate salts. The complex salts of aromatic iodine are of the following formula: wherein Ar1 and Ar2 may be the same or different and are aromatic groups having about 4 to 20 carbon atoms and are selected from the group consisting of phenyl, thienyl, furanyl, and pyrazoyl groups; Z is selected from the group consisting of oxygen, sulfur, a carbon-carbon bond, wherein R can be aryl (having approximately 6 to 20 carbon atoms, such as phenyl) or acyl (having approximately 2 to 20 carbon atoms, such as acetyl, or benzoyl) and wherein Ri and R2 are selected from the group consisting of hydrogen, alkyl radicals having from 1 to about 4 carbon atoms, and alkenyl radicals having from about 2 to 4 carbon atoms; m is zero or 1; and X can have the formula DQn, where D is a metal of Groups IB for VIII or a metalloid of the Groups IIIA in VA of the Periodic Table of the Elements (Chemical Abstracts version), Q is a halogen atom, and n is an integer having a value of 1 to 6. Preferably, the metals are copper, zinc, titanium, vanadium, chromium, magnesium, manganese, iron, cobalt, or nickel and the preferred metalloids are boron, aluminum, antimony, tin, arsenic and phosphorus. Preferably, the halogen Q is chlorine or fluorine. Illustrative suitable anions are BF4-B (CeF5) 4, PF6-, SbF6-, FeCl4-, SnCl5-, SnCl5-, AsF6-, SbF5OH-, SbCl6-, SbCl6-, SbF5"2, A1F5 ~ 2, GaCl4- , InF4", TiF6 ~ 2, ZrF6", CF3S03", and the like. Preferably, the anions are BF4", B (C6F5) 4", PF6", SbF6", AsF6", SbF5OH", and SbCl6 ~. More preferably, the anions are B (C6F5) 4 ~, SbF6", AsF6", PF6"and SbF5OH". Additional anions useful as the anionic portion of the catalysts and initiators of the present invention have been described in U.S. Pat. No. 5,554,664. The anions can be classified generally as fluorinated (including highly fluorinated or perfluorinated) tris alkyl or arylsulfonyl methyl corresponding to bis alkyl- or arylsulfonyl imides, as represented by Formulas I and II respectively, and referred to below as anions "meturo" and "imida" anions, respectively for brevity, (RfS02) 3C "(RfS2) 2N" (I) (II) wherein each Rf is independently selected from the group consisting of highly fluorinated or perfluorinated alkyl or fluorinated aryl radicals. The methides and imides can also be cyclic, when a combination of either of the two Rf groups are linked to form a bridge. The alkyl chains Rf can contain from 1 to 20 carbon atoms, with 1 to 12 carbon atoms. The alkyl chains Rf can be straight, branched or cyclic and are preferably straight. Heteroatoms or radicals such as divalent oxygen, trivalent nitrogen or hexavalent sulfur can interrupt the skeletal chain, as is known in the art. When Rf is or contains a cyclic structure, such a structure preferably has members of 5 or 6 rings, 1 or 2 of which may be atoms. The alkyl radical Rf is also free of ethylenic unsaturations or other carbon-carbon unsaturations: for example, this is a saturated heterocyclic, cycloaliphatic or aliphatic radical. By "highly fluorinated" it means that the degree of fluorination in the chain is sufficient to provide the chain with properties similar to those of a perfluorinated chain. More particularly, a highly fluorinated alkyl group will have more than half the total number of hydrogen atoms in the chain replaced with fluorine atoms. However, hydrogen atoms can remain in the chain, it is preferred that all hydrogen atoms are replaced with fluorine to form a perfluoroalkyl group, and that any of the hydrogen atoms remaining beyond at least half replaced with fluorine, are replaced with bromine or chlorine. Moreover, it is preferred that at least two of the three hydrogens in the alkyl group be replaced with fluorine, even more preferred that at least three of the four hydrogen atoms be replaced with fluorine and more preferably all the hydrogen atoms are replace with fluorine to form a perfluorinated alkyl group. The fluorinated aryl radicals of Formulas I and II may contain from 6 to 22 carbon atoms in the ring, preferably 6 carbon atoms in the ring, wherein at least one, and preferably at least two, carbon atoms in the ring of each aryl radical is substituted with a carbon atom. fluorine or a highly fluoro or perfluorinated alkyl radical as defined above, for example. , CF3. Examples of anions useful in the practice of the present invention include: (C2F5S02) 2N ', (C4F9S02) 2N-, (C8F17S02) 3C_, (CF3S02) 3C ", (CF3S02) 2N", (C4F9S02) 3C_, (CF3S02 ) 2 (C4F9S02) C ", (CF3S02) (C4F9S02) N", t (CF3) 2NC2F4S02] 2N-, (CF3) 2NC2F4S02C- (S02CF3) 2, (3, 5-bis) (CF3) C6H3) S02N-S02CF3, O F -C2F4S? 2N * S? 2CF.-i O F N- C2FjS? 2C "(SO: CF3): C6F5SO2C "(S02CF3) 2 C6F5S? 2N S02CF3 and similar. The most preferred anions are those described by formula I wherein Rf is a perfluoroalkyl radical having from 1 to 4 carbon atoms.

The aromatic groups Ari and Ar2 may optionally comprise one or more rings combined with benzene (for example, naphthyl, benzothienyl, dibenzothienyl, benzofuranyl, dibenzofuranyl, etc.). The aromatic groups can also be substituted if desired by one or more non-basic groups if they are essentially non-reactive with epoxide and hydroxyl functionalities.

Complex aromatic iodine salts are described more fully in U.S. Pat. No. 4,256,828.

The aromatic iodine complex salts useful in the invention are photosensitive only in the ultraviolet region of the spectrum. However, these can be sensitized to the range of the near ultraviolet light spectrum and the visible range by sensitizers for photolizable organic halogen compounds. Illustrative sensitizers include aromatic amines and colored aromatic polycyclic hydrocarbons, as described in U.S. Pat. No. 4,250,053.

Complex aromatic sulfonium salt catalysts suitable for use in the invention are of the following formula wherein R3, R4 and R5 may be the same or different, provided that at least one of the groups is aromatic. These groups may be selected from the group consisting of aromatic radicals having from about 4 to 20 carbon atoms (for example, substituted and unsubstituted phenyl, thienyl and furanyl) and alkyl radicals having from about 1 to 20 carbon atoms . The term "alkyl" includes substituted alkyl radicals (e.g., substituents such as halogen, hydroxy, alkoxy, and aryl). Preferably, R, R and R5 are each aromatic; Y Z, m and X are all as defined above with respect to the complex iodonium salts.

If R3, R4 or R5 is an aromatic group, it may optionally have one or more rings fused with benzo (eg, naphthyl, benzothienyl, dibenzothienyl, benzofuranyl, dibenzofuranyl, etc.). The aromatic groups can also be substituted if desired, by one or more non-basic groups if they are essentially non-reactive with epoxide and function with hydroxyl.

The trially substituted salts such as triphenylsulfonium hexafluoroantimonate and p- (phenyl) (thiophenyl)) diphenylsulfonium hexafluoroantimonate are the preferred sulfonium salts as described in U.S. Pat. No. 4,256,828, Example 37. Trifenylsulfonium hexafluoroantimonate (Ph3SSbF6) is a more preferred catalyst. Useful sulfonium salts are more fully described in U.S. Pat. No. 5,256,828.

The aromatic sulfonium complex salts useful in the invention are photosensitive only in the ultraviolet region of the spectrum. However, these may be sensitive to near ultraviolet light and the visible range of the spectrum by a selected group of sensitizers such as those described in U.S. Pat. Nos. 4,256,828 and 4,250,053.

The thermally activatable or photoactivatable organometallic complex salts useful in the invention include those described in U.S. Pat. Nos. 5,059,701, ,191,101, and 5,252,694. Such salts of organometallic cations have the general formula [(L1) (L2) M] + e (? -) q wherein M represents a metal atom selected from the elements of the periodic groups IVB, VB, VIB, VIIB and VIII, preferably Cr, Mo, W, Mn, Re, Fe, and Co; L1 represents none, one or two ligands contributing with the p-electrons which may be the same or different ligand selected from the group consisting of unsaturated cyclic and acyclic unsaturated compounds and substituted and unsubstituted carbocyclic aromatic groups and heterocyclic aromatic compounds, each capable of contribute with two to twelve electrons p for the valence shell of the metal atom M. Preferably, L1 is selected from the group consisting of 7-cycloheptatrienyl, 5-cyclopentadienyl, 3-allyl, substituted and unsubstituted compounds and 6-aromatic compounds selected from the group consisting of 6-benzene and 6-substituted benzene compounds (eg, xylenes) and compounds having from 2 to 4 fused rings, each capable of contributing from 3 to 8. p-electrons for the valence shell of M: L2 representing none or 1 to 3 ligands contributing with an odd number of electrons that can be the same or different ligand selected from the group consisting of carbon monoxide, nitrosonium, triphenyl phosphine, triphenyl stilbene and phosphorus, arsenic and antimony derivatives, provided that the total electronic charge contributes to M by L1 and L2 resulting in a residual positive charge of e network for the complex: e e is a number - integer with a value of 1 or 2, the residual charge of the complex cation; q is an integer having a value of 1 or 2, the number of complex anions X requires neutralizing the charge e in the complex cation: X is a halogen containing a complex anion, as described above.

Certain thermally activated curing agents for the epoxy resins (eg, the compounds which effect the curing and crosslinking of the epoxy by entering a chemical reaction therein) may be useful in the present invention. Preferably, such curing agents are thermally stable at temperatures at which mixing of the components takes place.

Suitable thermal curing agents include aliphatic, primary and secondary aromatic amines, for example, di (4-aminophenyl) sulfone, di (4-aminophenyl) ether, and fluorene diamines such as those described in U.S. Pat. No. 4,684,678, and 2,2-bis- (4-aminophenyl) propane; tertiary aromatic and aliphatic amines, for example, dimethylaminopropylamine; imidazoles; such as methylimidazole and pyridine; quaternary ammonium salts, particularly pyridinium salts such as N-methyl-4-picolinium hexafluorophosphate; sulfonium salts; boron trifluoride complexes such as BF3.Et20 and BF3. H2NC2H50H; hydrazines, such as adipohydrazine; and guanidines, such as tetramethylguanidine and dicyandiamide (cyanoguanimide, commonly known as DiCy); compounds having two or more carboxylic acid groups or compounds containing one or more carboxylic acid anhydride groups, and combinations of the latter compounds with accelerators such as imidazoles, as described in U.S. Pat. No. 5,229,464.

Additional epoxy thermal catalysts which may be useful in the present invention include simple pyridinium, quinolinium, indolinium, alkyl, aryl, and alkylaryl ammonium and phosphonium salts. Phosphonium and ammonium salts are described in PCT application WO 98/08906.

Preferred curatives useful in the invention include UV photocatalysts such as sulfonium and iodonium salts. Resin compositions containing such photocatalysts can be rapidly partially cured by UV radiation. The partially cured compositions show an improvement in dimensional stability in subsequent thermal lamination phases where heat and pressure are applied to laminate the adhesive to a substrate and further cure the adhesive.

The catalysts useful in the invention may be present in an amount in the range of 0.01 to 5 weight percent, based on the total weight of the epoxy material, preferably 0.01 to 4 weight percent, and more preferably 0.01 weight percent. at 3 percent by weight. The liquid or solid catalysts can be dissolved or dispersed in the selected epoxy resin. Heating may be required, but heating should not be sufficient to cure the epoxy resin. It is not necessary to use solvent for the procedure. The epoxy resin (as defined above) / catalyst mixture can then be pumped into an extruder for the melt processing stage. Alternatively, the catalyst could be added directly into the thermoplastic / epoxy mixture during the melt blending. In the case of solvent processing, the catalyst can be dissolved with the epoxy-containing material in a suitable solvent, or the catalyst can be pre-dissolved in the epoxy resin and then added to the solvent. Useful solvents include methyl ethyl ketone, toluene, ethyl acetate, butyl acetate, and cyclohexane.

In addition, the compositions of the resin of the present invention may include from 0 to 80 parts by weight of polyphenylene ether resins (PPE) per 100 parts by weight of the epoxy modified conjugated diene block copolymer with epoxy, in where the total weight of the copolymer of conjugated diene blocks with aromatic vinyl, modified with epoxy plus the PPE comprises from 90 to 100 weight percent of the total composition less than the curative. The polyphenylene ethers comprise a plurality of structural units having the formula Each Q1 is independently halogen, lower primary or lower alkyl (i.e., alkyl containing up to 7 carbon atoms), phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy, or halohydrocarbonoxy wherein at least two carbon atoms separate the halogen and the atoms of oxygen; and each Q2 is independently hydrogen or Q1 as defined above. Examples of suitable lower primary alkyl groups are methyl, ethyl, n-propyl, n-butyl, isobutyl, n-amyl, isoamyl, 2-methylbutyl, n-hexyl, 1, 2, 3-dimethylbutylc, 2-, 3- or 4-methylpentyl and the corresponding heptyl groups. Examples of lower secondary alkyl groups are isopropyl, sec-butyl and 3-pentyl. Preferably, any of the alkyl radicals are linear chains preferably branched. More frequently, each Q1 is alkyl or phenyl, and especially alkyl having 1 to 4 carbon atoms, and each Q2 is hydrogen.

Both polyphenylene ethers copolymers and homopolymers are useful additives in the process of the present invention. Suitable homopolymers are those containing, for example, 2,6-dimethyl-1,4-phenylene ether units. Suitable copolymers include random copolymers containing such combination units with for example 2, 3, 6-trimethyl-1, -phenylene ether units. Many suitable random copolymers as well as homopolymers are described in the literature of the patent, including U.S. Pat. Nos. 4,054,553, 4,092,294, 4,477,649, 4,477,651 and 4,517,341.

A preferred PPE, poly (2,6-dimethylphenylene oxide) is available under the tradename Blendex ™ HPP820 from General Electric Co., Pitsfield, MA.

Optionally, the resin compositions of the present invention may comprise an adhesion agent. Any suitable adhesion agent can be employed in the present invention. The tackifier may be present in 0.1-150 parts by weight of tackifiers per 100 parts of the resin composition. Useful tackifiers may include turpentine esters, aromatic and aliphatic hydrocarbon resins and mixtures thereof, and terpene resins. Suitable turpentine esters may include the turpentine family Hercoflex ™, Hercolyn ™, and Floral ™ and hydrogenated turpentine bonding agents, commercially available from Hercules Chemical Specialties Co., Wilmington, DE. Useful aromatic and aliphatic hydrocarbon resins may include the aliphatic / aromatic aliphatic / aromatic resin families Wingtacks ™ and Wingtack Plus ™ commercially available from Goodyear Tire and Rubber Co., Chemical Div. Akron, OH; the Escorez ™ family of aliphatic, aromatic resins and mixed aromatic / aliphatic resins commercially. available by Exxon Chemical Co. , Houston, TX; and the Piccotac ™ and Regalrez ™ families of aromatic and aliphatic resins, commercially available by Hercules. Useful terpene resin bonding agents may include the Zonarez ™ family of terpenes, commercially available from Arizona Chemical Div., International Paper Co., Panama City, FL and the Piccolyte ™ and Piccofyn ™ terpene families commercially available from Hercules. Preferably, the tackifiers useful in the invention include Escorez ™ blended aliphatic / aromatic hydrocarbon bonding agents.

Additionally, the composition of the resin may also comprise a polyol. The polyol is preferably reactive with epoxy groups under curing conditions. The polyol preferably modifies the cure rate and the final adhesive performance, and may be useful as a chain extender in the epoxy resin formulations. The polyol can be included in a weight ratio, relative to the epoxy resin, of between 0.1 / 99.9 to 40/60.

Examples of such polyols include ethylene glycol, 1,2- and 1,3-propane diol, 1, 2-, 1, 3-, 1,4- and 2,3-butane diol, 1,5-pentane diol, , 6-hexane diol, 1,8-octane diol, neopentyl glycol, 1-bishydroxymethyl cyclohexane (1,4-cyclohexane dimethanol), 2-methyl-l, 3-propane diol, dibromobutane diol, glycerol, trimethylolpropane, 1, 2,6-hexanetriol, 2,2-dimethyl-l, 3-propane diol, 1,6- and 2,5-hexane diol, 1,12-dodecane diol, 1,12- and 1,18-octadecane diol, 2,2,4- and 2, 4, 4-trimethyl-l, 6-hexane diol, cyclohexane-1,4-diol, 2,2-bis- (4-hydroxycyclohexyl) -propane, bis- (4-hydroxyphenyl) ) -methane, bis- (4-hydroxyphenyl) -sulfone, 1,4-bis- (hydroxymethyl) -benzene, 1,4-hydroxy-benzene, 2,2-bis- (4-hydroxyphenyl) -propane, 1, 4-bis- (? -hydroxyethoxy) -benzene, 1,3-bis-hydroxyalkyl hydantoins, tris-hydroxyalkyl isocyanurates and tris-hydroxyalkyl-triazole-3, 5-diones, trimethylolethane, pentaerithritol, quinitol, mannitol, sorbitol, diethylene glycol , triethylene glycol, tetraethylene glycol, dipropylene glycol, higher polypropylene glycols, higher polyethylene glycols, higher polybutylene glycols, 4,4'-dihydroxy diphenylpropane, dihydroxymethyl hydroquinone and combinations thereof.

High molecular weight polyols include polypropylene oxide and polyethylene polymers in the molecular weight range of about 200 to 20,000, such as the Carbowax ™ series of poly (ethylene oxide) compounds (available from Union Carbide Corp., Danbury , CT), caprolactone polyols in the molecular weight range from about 200 to about 5000, such as the Tone ™ series of polyols (available from Union Carbide), poly (tetramethylene ether) glycols in the molecular weight range of about 200 to about 4000, such as the Terethane ™ 1000 and 2000 polyol series (available from DuPont Co., Wilmington, DE), hydroxy-terminated polybutadiene materials, such as series Poly bd ™ polyols (available from Elf Atochem, Philadelphia, PA), polycarbonate diols, such as the KM ™ series, including KM-10-1667 ™ and KM-10-1733 ™ (available from Stahl USA (Peabody, MA), polyurethane diols, such as K-flex ™ materials, including K-flex UD-320-100 ™ (available from King Industries, Norwalk, CT), aromatic polyether polyols such as Synfac ™ materials, including Synfac 8024 ™ (available from Milliken Chemical, Spartanburg, SC), and poly (tetramethylene oxide) / polycarbonate random copolymers, such as PolyTHF ™ CD series polyols (available from BASF Corporation, Mount Olive, NJ). Preferred polyester polyols include the Desmophen ™ family available from Bayer, Elkart, IN. A preferred acrylic polyol is Joncryl ™ 587, commercially available from S.C. Jonson & Son, Inc., Racine, Wl.

Another group of preferred polyols includes the hydroxyalkylated bisphenol derivatives. Preferred polyols in this group have the following general formula: (H O - R6 _ OA) 2 - CR7 Re wherein R6 is a cyclic alkylene group either linear or branched (eg, methylene, ethylene, butylene, decylene) consisting of 1 to 10 carbon atoms, or an aralkylene group consisting of 7 to 14 carbon atoms (eg, benzylidene, 1,2-diphenylethylene, phenothylene); R7 and R8 can independently be an alkyl group, an aralkyl group, a cycloalkyl group, an aralkyl group, or an aryl group of about 1 to 30 carbon atoms (preferably methyl, ethyl, ethyl, and trifluoromethyl) and none of about 1 to 10 heteroatoms, and R7 and R8 together may comprise an alkylene, cycloalkylene, arylene, alkarylene or aralkylene group containing about 2 to 660 carbon atoms and none of about 1 to 10 heteroatoms; A substituted or unsubstituted arylene group may preferably be about 6 to about 12 carbon atoms, more preferably p-phenylene, o-phenylene or dimethylnaphthalene.

Preferred hydroxylakylated specific bisphenols include 9,9-bis-4- (2-hydroxyethoxyphenyl) fluorene (for example, fluorene-hydroxyethylated bisphenol), 2,2-bis-4- (2-hydroxyethoxyphenyl) butane (e.g., 2-butanone hydroxyethylated bisphenol), 2,2-bis-4- (2-hydroxyethoxyoxyphenyl) hexafluoropropane (for example, hydroxyethylated bisphenol F), 1,2-bis-4- (2-hydroxyethioxyphenyl) propane, 2,2-bis-4- (2-hydroxyethoxyphenyl) norbornane, 2,2-bis-4- (2 -hydroxethoxyphenyl) -5,6-cyclopentanonorbomban and l, l-bis-4- (2-hydroxyethoxyphenyl) cyclohexane.

Other polyols suitable for use in the production of epoxy resins useful in the invention include the hydroxyalkyl esters obtained by the addition of optionally substituted alkylene oxides, such as propylene oxide, butylene oxide and styrene oxide, in the polyols above. mentioned.

The optional components of the present invention are stabilizers that inhibit or retard degradation by heat, oxidation, formation of protective film and color formation. The stabilizers are typically added to the formulations of the invention to protect the polymers against degradation by heat and oxidation during preparation, use and storage at high temperatures of the compositions. Additional stabilizers known in the art can also be incorporated into the composition to protect against for example oxygen, ozone, and ultraviolet radiation. However, these additional stabilizers must be compatible with the stabilizers named above.

Further, the composition of the resin may comprise from 0 to 99 parts by weight of a block copolymer of aromatic vinyl conjugated diene per 100 parts by weight of an epoxy modified conjugated diene block copolymer with vinyl aromatic. The styrene-isoprene and styrene-butadiene block copolymers wherein the diene block can be hydrogenated, are preferred members of this group.

Various auxiliaries may also be added to the compositions of the invention to alter the physical characteristics of the final material. Useful auxiliary agents include thixotropic agents such as fumed silica; pigments to increase the tone of the collo es such as ferric oxide, black carbon and titanium dioxide; fillers such as mica, silica, acicular or pointed wollastonite, calcium carbonate, magnesium sulfate, and calcium sulfate, thermal or electrical conduction fillers, including metal particles, graphite, and metal-coated microspheres; fibers cut into chips and hair, including glass and coal; clays such as bentonite; glass beads and bubbles; reinforcing materials such as woven and nonwoven webs of organic and inorganic fibers such as polyester, polyimide, glass fibers, polyimides such as poly (p-phenylene terephthalamide), carbon fibers, and ceramic fibers. Amounts of up to about 200 parts of auxiliaries can be used per 100 parts of the resin composition.

The epoxy-modified aromatic vinyl-conjugated diene block copolymer can be prepared by at least partial epoxidation unsaturated bonds in the polymer block derived from the polymerization of a compound having a conjugated double bond known in the art and described by example in EP 0658603A2.

The materials of the present invention can be prepared by continuous or batch processes. It can either involve the fusion or solution process.

The batch melting process can be achieved by the addition of the conjugated diene block copolymer with aromatic vinyl, modified with thermoplastic epoxy, typically in pellet form, to a preheated mixer such as a Brabender mixer (C. W. Brabender Instruments, Inc., South Hackensack, NJ) equipped with for example, cam or sigma blade. After stirring for about 5 minutes, the thermoplastic was melted and a mixture of epoxy resin and cured for the epoxy was added with continuous stirring. The resulting mixture was stirred to ensure complete mixing, at a duration and temperature below which the epoxy component could be substantially cured, and removed from the mixture. The mixture can then be coated, molded, formed, shaped or pressed into a final configuration. The shaped object can then be irradiated and / or heated to cure the epoxy resin component. In particular, when a sheet or thin film is desired, the molded mass can be pressed into a hot flat plate press such as a Carver Laboratories press (F. Carver, Inc., Wabash, IN).

The continuous melting process can be achieved using an extruder, for example. , an extruder with double screws, equipped with a downstream orifice, mixing elements and an appropriate outlet hole (film matrix, foil matrix, fiber matrix, profile matrix, etc.) and roll molding and roll finishing appropriate. The roll molding can be cooled or maintained at a certain temperature by thermostatic means. The solid thermoplastic is added at the inlet end of the extruder and processed using a certain temperature that is appropriate for the thermoplastic which will not substantially cure the epoxy component (s), taking into account the residence duration of the material in the extruder during processing. The solid epoxy resins and the curatives can be added with the thermoplastic to the inlet end of the extruder or at other points along the extruder prior to the mixing zones. Liquid epoxy resins and resin curing or curative agents can be dissolved or dispersed in the epoxy resins, they can be injected via the gear pump or injection through the downstream hole in the extruder prior to the mixing of the elements. The speed of the occupation line is adjusted according to the output (leaf, fiber, etc; In cases where the thermal cure of the epoxy component (s) is desirable immediately after extrusion, eg, before the thermoplastic copolymer solidifies and cools, additional heating of the extruder can take place directly in the orifice from the die or in a molding wheel. When it is desired that the polymerizing agents of the resin take place after the solidification and cooling of the thermoplastic polymer, the source (s) of heat can be located just before taking the roll. Finally, when it is desired that the curing of the epoxy resin does not take place after the extrusion, such heating devices are absent.

In the case where the curing of the epoxy components, extrusion is desired immediately after, for example. , before it solidifies and cooled the thermoplastic polymer. The UV light radiation of the heated extrudate material can take place directly in the orifice of the matrix. Irradiation can be achieved by any number of commercially available UV sources such as one or more light bulbs "H" or "D" Fusion Systems (available from UV Fusion Curing Systems, Rockville, MD) or Silvania BL 350 bulbs.

When it is desired that the curing of the epoxy takes place after the solidification and cooling of the thermoplastic polymer, the source (s) of light "can be located just before taking the roll." Finally, when it is desired that the cure does not take place immediately Epoxy after extrusion, irradiation devices are absent and precautions must take place to prevent exposure of UV rays.

Within the scope of the invention is a mixed film, obtained from a sheet die or mold which can be stretched either uniaxially or biaxially as it emerges from the mold or matrix. The cure, as indicated above, may take place before, during or after such stretching.

Processing in solution of the process can be achieved by mixing the copolymer of conjugated diene blocks with aromatic vinyl, modified with epcxy, epoxy resin, and curative agents in a solvent. The process can take place in a tank equipped with a mixer, and optionally a heater. The components can be substantially dissolved in the solvent, obtaining an opaque, slightly cloudy or clear mixture or solution. The solution can be transported to a coating where the solution can be coated on a substrate that is used in the assembly of an electronic circuit device. Alternatively, the solution can be coated on a carrier or release liner. The coating method can include a skew coating, chip coating, kiss coating, curtain coating, gravure coating, as well as other coating methods known in the art. The substrate of the coating or carrier can then be dried to remove the solvent. Epoxy curing can take place in the drying phase or after, using the methods previously described for the resin fusion process.

Where a film is used as an adhesive or coating, the material in an uncured state can be applied as a sheet to its final substrate and cured in itself by the application of heat, pressure, UV light, or combinations thereof. same in any order. Alternatively, the uncured films can be applied to a substrate, then partially cured using UV or heat radiation, followed by the application of a second substrate to the partially cured adhesive, after which the construction was completely cured using UV radiation, heat and / or pressure. In addition, uncured films can also be partially cured using UV or heat radiation prior to application to a substrate, then applied to a substrate and further cured using heat and / or pressure. The adhesive films can be of a thickness in the range of 0.0025 mm to 6.35 mm.

When hot curing is used, the method of heat generation is not restricted. Common methods include the combustion of fuel and the conversion of electrical energy into heat. The latter may include resistance heating (including infrared heating), induction heating, electric arc (plasma) heating, and dielectric heating (including microwave heating).

This invention is useful in the production of high performance adhesives and coatings, especially where improved heat resistance and moisture insensitivity are required. For example, this invention is useful in film lamination for electronic applications. The present invention is useful as an adhesive, an encapsulant, a protective coating layer or combinations thereof.

The substrates for the composition of the copolymer resin may be those known in the art including polyimides, metal hardeners, microcircuits or semiconductor chips, boards with printed circuits, glass, ceramics, and metal foils (preferably copper).

The electronic circuit device comprising the resin composition of the invention is useful in interleaved grid arrays (BGA), laminated microinterconnectors (LMI), chip scale (CSP) packages, chips or chips in cards, glass chips, and flexible circuits where the devices are subject to welding reflow even in the presence of high humidity.

The objects and advantages of this invention are further illustrated by the following examples, but the particular materials and amounts thereof mentioned in these examples, as well as other conditions and details, should not be considered to unduly limit this invention.

EXAMPLES Many block copolymers (SB) of styrene-butadiene are mixed by fusion with epoxy resins and triarylsulfonium hexafluoroantimonate (Ar3SSbF6) in a Brabender mixer. The Ar3SSbF6 was pre-dissolved in the liquid epoxy resin or, in cases where no epoxy resin is added, the Ar3SSbF6 was dissolved in methyl ethyl ketone and added to the Brabender. Methyl ethyl ketone was evaporated during the mixing process. The conventional, epoxidized, mated SB block copolymers were evaluated. A summary of the thermoplastics based on SB is presented in Table 1, below.

The Epofriend materials are SB block copolymers in which a certain amount of butadiene block unsaturation has been epoxidized. These materials are sold by Daicel Chemical Industries, Ltd. Kraton FG1901X and FG1924X are SEBS (hydrogenated butadiene blocks) materials that have grafted anhydride therein. Kraton D1101 is a styrene-butadiene block copolymer. These Kraton materials are sold by Shell Chemical Company.

The films (0.037 mm thick) are pressed by melting from the blends into a platen dam having electrically heated platens (F. Carver, Inc., Wabash, IN). The films were used to produce samples of T detachment at 180 degrees. The samples of the gridded array type (TBGA) and LMI samples to heat and assess the sensitivity to moisture. The thicker films (1.25-2.00 mm thick) were also pressed from the mixtures by Dynamic Mechanical Analysis (DMA).

Resistance to Detachment to Kapton E Prepare the upper release layer specimens by placing the adhesive film on a 0.05 mm thick Kapton E polyimide film substrate, irradiating UV to the adhesive film at 2.2 milliwatt / cm2 for 3 minutes using a Silvania 350BL bulb, placing another Kapton E substrate at the top and laminating at 210-220 ° C and 690 kPa for 50 minutes. The resulting laminate was cut into 0.64 mm wide tapes and evaluated for T detachment at 180 ° at room temperature using an Instron instrument (Instron, Inc., Park Ridge, IL). The peel strengths are shown in Tables II, III, and IV. Peel strengths for mixtures of various SB block copolymers with Epon 828 (Shell Chemical) containing 2 wt.% Ar3SSbF6 based on the weight of Epon 828 are presented in Table II. Blends containing maleate-containing or epoxidized SB block copolymers had higher peel strengths than the conventional or non-functionalized SB (Kraton D1101). In the case of epoxidized SB, the material with the highest level of epoxidation. The Epofriend A1020 offers the greatest resistance to detachment. The peel strength was maximized with Epon 828 at 5% by weight.

Peel strengths for blends of Epofriend A1020 with ERL 4221 (Union Carbide) containing 2 wt.% Ar3SSbF6 based on the weight of ERL 4221 were also determined and the results are presented in Table III. The results of the detachment were similar to those obtained with Epon 828.

In the mixtures whose peel strength are presented in Tables II and III, the concentration of epoxy catalysts, Ar3SSbF6 was a constant percentage of the amount of the epoxy resin. Thus, the concentration of Ar3SSbF6 based on the total amount of the block copolymers SB plus resin actually decreased as the level of epoxy resin decreased. For example, the mixture with 0% by weight epoxy resin did not contain Ar3SSbF6 and the mixture with 2.5% by weight epoxy resin contained half the mixture with 5.0% by weight epoxy resin. Many mixtures were made containing 0.1% by weight Ar3SSFF6 based on the total weight of the SB block copolymers and epoxy resin (Epon 828). Their resistance to detachment to Kapton E are presented in Table IV.

In general, blends containing from 100 to 95% by weight of the copolymer of epoxidized SB blocks and epoxy resin of 0 to 5% by weight provided the highest peel strengths. Copolymers with SB epoxy blocks with equivalent weights of 500 and 1000 (Epofriend A1020 and A1010) offer the highest peel strengths. These resistances to detachment to Kapton E were excellent. For comparison, the peel strength of Pyralux LF and Kapton KJ (commercially available adhesives from DuPont) to Kapton E are both approximately 70.0 N / dm.

A film of Epofriend A1020 at 95% by weight / Epon 828 at 5% by weight with Ar3SSbF6 2% by weight (based on Epon 828) was irradiated with UV at 2.1 milliwatts / cm2 for 10 minutes, and then used to make samples of the T-peel layer immediately, 1 week later, and 1 month later. The resistance to detachment to Kapton E are 194.3, 171.5, and 221 N / dm, respectively. These data indicate that the SB block copolymer / epoxy film can be irradiated by UV at the time of its manufacture rather just before its use in the lamination.

Shear Effort Module The DMA was carried out in 1.25 - 2.0 mm thick adhesive films that were not irradiated and irradiated with UV at 2.1 milliwatt / cm2 for 10 minutes just before the DMA. The samples were heated from room temperature to 210 ° C at 2 ° C / min and then kept at 210 ° C for 30 minutes to simulate thermal curing. After this stay, it was rapidly cooled from 25 ° C to 20 ° C / minute, allowing to equilibrate for 5 minutes, and then heated to 250 ° C to 2 ° C / min. In general, films that are irradiated by UV provide high shear modulus, G ', at 220 ° C (reflow temperature of the weld). The graph of the shear force modulus vs. temperature of Epofriend A1020 95% by weight / Epon 828 at 5% by weight with 0.1% by weight of Ar3SSbF6 based on the total weight of Epofriend A1020 + Epon 828 is shown in FIG 1. The figure shows that the stress modulus of irradiated films were higher than non-irradiated films. In the figure, the trace A represents the data of a film that was irradiated with UV, and the trace B represents the data of a film that was not irradiated with UV. In the case of the UV-irradiated sample, G 'decreases with increasing temperature to 139 ° C, the starting temperature at which point G' begins to decrease due to the reaction of the epoxy groups. G 'continued to increase through 30 minutes remaining at a temperature of 210 ° C. The difference in G 'after remaining 30 minutes compared to its value at the initial temperature is referred to as dG' in Table V. After remaining 30 minutes, the sample temperature was lowered to 25 ° C, and then elevated at 250 ° C. The increase in G 'that developed in the first heating and remained in the second heating out of 250 ° C. Table V summarizes the DMA data for the UV-irradiated mixtures. The nomenclature for the compositions follows the format: Thermoplastic SB% by weight / resin Epoxy% by weight (Ar3SSbF6% by weight). All% by weight were based on the total weight of the SB + epoxy resin thermoplastic.

For compositions of the copolymer with blocks SB of 100-95% by weight and Epon 828 of 0-5% by weight, those containing non-functionalized SB (Kraton D1101) or slightly functionalized SB (Kraton FG1924X and Epofriend A1005) showed an increase very small of the shear module in curing. The compositions containing Epofriend A1010, which is more highly functionalized, showed slightly an increase in the shear modulus in healing, and those containing Epofriend A1020, the more functionalized material exhibited a more pronounced increase in the shear modulus. This is in accordance with the fact that the most highly functionalized material provided the highest degree of crosslinking. The increase of the concentration of Epon 828 to 10% and greater increase of the shear modulus for a point; however, the resistance to detachment began to decline.

Sensitivity assessment for heat and humidity Sensitivity to moisture and heat was evaluated by procedures similar to those by Joint Industry Standard, "Moisture / Reflow Sensitivity Classification for Plastic Integrated Circuit Surface Mount Devices", October 1996, J-STD-020, conducted by JEDEC level 1 Typical compositions to be evaluated comprise the epoxidized styrene-butadiene block copolymers, optionally an epoxy resin, and curing Ar3SSbF6. In addition, compositions comprising Epofriend A1020 and 0.25 or 11.1% by weight of 9,9 '-bis (3-methyl-4-aminophenyl) fluorene (OTBAF, 3M, St. Paul. MN), an aromatic diamine curative. , respectively, were mixed in a Brabender mixer. The 0.037 mm thick films were pressed to melt from the mixing at 180 ° C. Also, a mixture of Epofriend A1020 of 60% by weight, polyphenylene oxide (PPO) HPP 820 (General Electric Plastics, Pittsfield, MA) at 30% by weight, and EPON 828 at 10% by weight based on the weight percentage total of all three components, were prepared in toluene to form a cloudy solution with 14% by weight solids. The solution additionally contained 0.075% by weight of Ar3SSbF6 based on the total weight of the components thereof. The solution was coated with a knife in the pcli / ethylene terephthalate coating), then air-dried for 24 hours, followed by further drying in an oven for 2 hours at 150 ° C. A 0.017 mm thick film was produced.

The lamination procedure followed by all constructions (flexible 2-layer circuitry, TGBA, and LMI) was similar to that used in the T-detachment samples, above, except in the case of the sample in which the OTBAF was the healing agent. In this case, only the thermal cure at 231 ° C was used for 30 minutes (ie, no UV radiation was used).

The heat and humidity sensitivity evaluations were conducted by drying the constructions cured at 125 ° C for 24 hours, and then placing them in a humidity chamber at 85 ° C / R.H. at 85% for 168 hours. Within 15 minutes of removing the humidity chamber, the constructions were passed through an Infrared Model IR-12 (Automated Production Systems, Inc., Huntingdon Valley, PA) Reflow Furnace (IR) which heated the constructions of the ambient temperature at 145 ° C in about 70 seconds, the constructions were maintained at 145 ° C for approximately 90 seconds, then the constructions were heated to a maximum temperature of 220 ° C. Heating from 145 ° C to 183 ° C took 20 to 25 seconds. The constructions were exposed to temperatures above 183 ° C for approximately 160 seconds. Including 10 to 40 seconds at a maximum temperature of 220 ° C. The constructions were visually observed after they were passed through a reflux oven. Any blister or vacuum that was observed was a failure. After the constructions passed out of the reflux oven, they were then observed under a microscope to detect any voids, blebs or other defects. If the construction is free of defects, it is sent through the reflow oven again. It is estimated that a construction "passes" if no defects were observed after two cycles through the IR reflow oven.

Two layer flexible circuitry The evaluation of sensitivity to moisture and heat was performed in constructions having two layers of flexible circuitry laminated together by means of 0.037 mm thick films of adhesive of the invention using curative ArSSbF6. The flexible circuitry was a copper circuitry on a 0.025 mm thick Kapton E substrate. The construction was performed in such a way that the adhesive layer was in contact with the copper part of the fexible circuitry and in contact with the polyimide side (i.e., the trace without copper) of another piece of the flexible circuitry . The construction measured 5.0 cm x 5.0 cm. The results are presented in Table VI TBGA constructions The evaluation of sensitivity to moisture and heat was carried out in constructions similar to TBGA composed of a layer of EKapton E film (0.05 mm thick) laminated with the SB / Epoxy thermoplastic mixture (0.037 mm thick film) to a metal hardener (nickel-plated copper). The square construction was approximately 4.3 cm x 4.3 cm. The lamination procedure followed was similar to that used for the T-detachment samples except that the lamination pressure was 1749 KPa. Except as mentioned, the temperature profile of the TBGA constructions passed through the IR reflow oven was similar to those shown for the constructions of the flexible 2-layer circuitry. The results are presented in Table VII. Ar3SSbF6 healing unless otherwise indicated The data in Table VII show that mixtures comprising 100 to 95% by weight of Epofriend A1020 and 0-5% by weight epoxy resin provide constructions having superior heat and moisture insensitivity similar to that required to pass the level 1 of JEDEC. It was observed that all the formulations mentioned in Table VII that fail, failed in the first cycle through the IR reflow oven. All the formulations that passed the first cycle also passed the second cycle.

A TGBA construction with an adhesive film of 95 Epofriend A1020 / 5 Epon 828 (0.1) underwent an identical evaluation to that described above, except that the peak temperature of the construction passing through the IR reflow oven was increased to 240 ° C. This is a more demanding heating profile than that required by the JEDEC level 1 operation. The construction passed this evaluation.

Furthermore, for the results obtained in the adhesive formulations of Kapton E operation (flexible circuit substrate) of the invention, it was observed in the 0.025 mm E Kapton film in which the copper circuitry was deposited. The size of the TBGA construction and the hardener metal was the same as previously used. A TBGA construction with an adhesive film of 97.5 Epofriend A1020 / 2.5 ERL 4221 (0.05) underwent an identical evaluation to that described by the constructions in Table VII (maximum temperature of 220 ° C), this construction was subjected to cycles through an IR reflow oven in a total of three times. The construction passed the evaluation. Another TBGA construction with a 0.062 mm thick adhesive film of 97.5 Epofriend A1020 / 2.5 Epon 828 (0.1) underwent an identical evaluation, except that the maximum construction temperature in the cyclization through the IR reflow oven was increased to 240 ° C. This construction was cyclized through an IR reflow oven three times. The construction passed this evaluation. The adhesive film in the latter case was melt-blended in a 25mm Berstorff double screw extruder (Berstorff Corp., Charlotte, NC) rather than a Brabender mixer.

Further TBGA constructions were evaluated in which the effectiveness of the adhesive formulations of the invention were observed in the 0.025 mm thick Kapton E film in which the gold plated copper circuitry was deposited. The hardened metal was nickel-plated copper, 0.5 mm thick and 29 mm x 29 mm with a 13 mm x 13 mm hole drilled through the center. The films of 95 Epofriend A1020 / 5 Epon 828 (0.1) are irradiated with UV at 2 mW / cm2 for 3 minutes and then laminated between the flexible circuit and the hardened metal for 50 minutes at 215 ° C and 690 Kpa. The laminated packages were baked for a minimum of 24 hours at 125 ° C and then placed in an 85 ° C / 85% RH oven for 168 hours.

After removing them from the oven, the packages were placed at room temperature for at least 15 minutes and no longer than 4 hours. Two methods were used to check sensitivity to moisture: (1) hot plate and (2) convection oven: The hot plate was heated to 220 ° C. The package was placed on the hardened side for 1 minute and immediately heated to 220 ° C. the sample was observed through an enlarged chamber for delamination or cracking. Any of the samples that did not delaminate or crack were checked twice under a microscope to confirm that less than 10%. If you do not have, the package "passes". It is noted that the hot plate method has a more severe ramp rate than the JEDEC Test method A112-A, which requires a ramp temperature of 6oC / second maximum and 220 ° C for 10-40 seconds. Thus, heating with a hot plate was a more severe test than that required by the JEDEC standard: For the samples of the present invention, 5 packages passed this hot plate protocol.

The convection oven was a Unitherm SMR 400 (Vitronics Corp., Newmarket NH). A thermocouple placed in the package indicated that the heat increased with a velocity of approximately 3 ° C / second, reaching a maximum of 220 ° C and permanence at 220 ° C and above for approximately 40 seconds. Samples were observed under a microscope to confirm less than 10% voids. For the samples of the present invention, 4 packages passed the protocol of the convention oven.

LMI constructions LMI constructions also undergo evaluations of sensitivity to moisture and heat. The LMI construction consisted of 5 layers of flexible circuitry (traces of copper in the Kapton E film) that were laminated together with 4 layers of adhesive; alternating layers of flexible and adhesive circuitry. The circuitry of each flexible layer was arranged in nine square regions of 3.3 cm x 3.2 cm that were placed in a 3 x 3 grid. On the lamination, nine 3.2 cm x 3.2 cm compounds were formed containing 5 layers of flexible and 4 layers. adhesive layers. The lamination conditions were the same as those described by the samples of the upper T release layer, above. The temperature profile of the LMI constructions passed through the IR reflow furnace similar to the 2-layer flexible circuitry construction described above. The construction of LMI were considered to be "approved", no defects were observed after two cycles through the IR reflow oven. The results of the evaluation are shown in Table VIII below: Evaluation (THB) of the deviation of the Humidity Temperature.

The Kapton E film (0.005 cm thick) was laminated to flexible circuitry having a Kapton E film that was interdigitated to the test circuit by using Epofriend 95 A1020 / Epon 5 828 adhesive film (0.1). The adhesive filled the space between interdigitated copper traces. The traces of copper were approximately 70 micrometers wide with 80 micrometers of space between them. The current loss is monitored to determine any deterioration in the development. Two test circuits were evaluated, and both were placed on a log for 1000 hours without any deterioration in their development and exhibited very little current loss.

Various modifications and alterations of the invention will be apparent to those skilled in the art without departing from the scope and intentions of the invention, and it should be understood that this invention does not unduly limit the illustrative embodiments set forth herein.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (12)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. An electronic circuit device comprising a resin composition that includes from 90 to 100 weight percent of a curable epoxy-conjugated diene block copolymer modified with curable epoxy, from zero to 10 weight percent of an epoxy resin , and an epoxy curing agent, the weight percent of the copolymer and the epoxy resin are based on the weight of the epoxy-only material of the curative agent, characterized in that the epoxy-modified aromatic vinyl-conjugated diene block copolymer has an epoxy equivalent weight in the range of 100 to 2500.

2. The device with electronic circuit according to claim 1, characterized in that said epoxy resin comprises an alicyclic or aliphatic epoxy.

3. The device with electronic circuit according to claim 1, characterized in that said epoxy resin comprises an aromatic epoxy.

4. The device with electronic circuit according to claim 2, characterized in that said alicyclic epoxy is selected from the group consisting of cyclohexane dioxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxycarboxylate. 6-methylcyclohexylmethyl-3, 4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, dipentene dioxide, 2- (3,4-epoxycyclohexyl) ) -5, l "-spiro-3", 4"-epoxycyclohexane-1,3-dioxane, 4- (1, 2-epoxyethyl) -1, 2-epoxycyclohexane, and 2,2-bis (3, 4- epoxycyclohexyl) propane.

5. The electronic circuit device according to claim 3, characterized in that said aromatic epoxy is selected from the group consisting of polyglycidyl ethers of polyhydric phenols and their derivatives, cresol-novolac epoxy resins, phenol-novolac epoxy resins,; and glycidyl esters of aromatic carboxylic acids, and mixtures thereof.

6. The electronic circuit device according to any of claims 1-5, characterized in that said block copolymer of epoxy-modified aromatic vinyl-conjugated diene is selected from the group consisting of epoxidized styrene-butadiene block copolymers and block copolymers of partially hydrogenated styrene-butadiene, epoxidized.

7. The device with electronic circuit according to any of claims 1-6, characterized in that said curative is a triaryl sulfonium salt.

8. The device with electronic circuit according to any of claims 1-8, characterized in that said block copolymer of conjugated diene blocks with epoxy-modified aromatic vinyl has an equivalent weight of epoxy in the range of 100 to 1000.

9. The electronic circuit device according to any of claims 1-8, characterized in that said 90 to 100 weight percent of a curable, epoxy modified aromatic vinyl-conjugated diene block copolymer includes a polyphenylene ether resin. in an amount of up to 80 parts of said polyphenylene ether per 100 parts of said block copolymer of conjugated diene with curable epoxy modified vinyl aromatic.

10. The device with electronic circuit according to any of claims 1-9, characterized in that said copolymer of conjugated diene blocks with epoxy-modified aromatic vinyl and optional epoxy resin is cured by one or both of heat and UV radiation characterized in that said device exhibits stability for conditions of 85 ° C and 85% relative humidity for 168 hours followed by a temperature of 220 ° C for 10 to 40 seconds.

11. A method of using an electronic adhesive, coating or encapsulation, characterized in that it comprises the steps of: providing a curable resin composition that includes from 90 to 100 weight percent of an epoxy-modified, aromatic vinyl-conjugated diene block copolymer, optionally an epoxy resin, and an epoxy curative, the weight percent of the copolymer and the epoxy resin was based on the weight of the material that had epoxy exclusive of the curative agent, and incorporating said resin composition as an adhesive, coating layer or encapsulant into an article.

12. The method according to claim 11, characterized in that it additionally comprises the steps of subjecting the composition of the curable resin to one or both of curing by means of UV or thermal radiation.