MXPA99005470A - Die attach adhesive compositions - Google Patents

Abstract

A novel thermally reworkable die attach adhesive composition for attaching a semiconductor device to a substrate is provided. The composition comprises (a) a thermally reworkable cross-linked resin produced by reacting at least one dienophile having a functionality greater than one and at least one 2,5-dialkyl substituted furan-containing polymer, and (b) at least one thermally and/or electrically conductive material present in an effective amount up to 90%by weight of the die attach composition to provide a conducting medium.

Description

COMPOSITIONS OF ADHESIVE OF UNION TO PLAQUITA FIELD OF THE INVENTION This invention relates to an adhesive composition. In one aspect, the invention relates to adhesive-bonding adhesive compositions suitable for attaching semiconductor devices to substrates of the carrier.

BACKGROUND OF THE INVENTION The tile bonding adhesives are used to bond the semiconducting device such as a silicon insert or chip to a substrate such as a conductor frame or a printed circuit board. During the assembly of the semiconductor package, the insert-bonding adhesive holds the device firmly in place during wire connection and encapsulation. They can provide electrical and / or thermal contact between the device and the substrate by incorporating electrically and / or thermally conductive fillers into the adhesive formulation.

REF .: 30471 Examples of commonly used adhesive-bonding adhesives are eutectic solders, conductive epoxy resins, and conductive polyimides. Eutectic solders are metal alloys typically made with gold. A "preform", which is a sheet of metal cut to the shape and size of the semiconductor chip, is deposited on the desired packaging substrate and heated to a temperature close to the melting point of the preform. The chip can then be placed on the preform with a rubbing motion. Eutectic welds are expensive and difficult to process. Conductive epoxy resins are typically low viscosity pastes containing electrically conductive fillers. The epoxy resin is applied to the substrate by conventional means and the device is then placed in contact with the coated substrate. The epoxy resin can then be cured in one step. Conductive polyimides are similar to conductive epoxy resins. The thermosetting adhesive adhesives, mainly formulations based on epoxy resin, are used to join semiconductor devices to substrates. The processes of reprocessing to replace defective chips usually involves the use of heat both below the substrate and on top of the device, accompanied by a cutting force to remove the insert from the substrate. Historically, reprocessing has been relatively simple since the devices are small and widely spaced from each other. However, emerging packaging technologies such as multiple chip modules use both larger devices and a smaller spacing between them and therefore the possibility of substrate damage during reprocessing arises. Thus, it is desirable to provide an adhesive-bonding adhesive composition that allows reprocessing to be more easily processable.

BRIEF DESCRIPTION OF THE INVENTION According to the invention, a thermally reprocessable insert-binding composition is provided, comprising: (a) a thermally reprocessable crosslinked resin, produced by reacting at least one dienophile having a functionality greater than one and at least one polymer containing furan substituted with 2,5-dialkyl, and (b) at least one thermally and / or electrically conductive material, present in an effective amount of up to 90% by weight of the insert-binding composition, to provide a conductive medium. Such an insert-binding composition provides an easily reprocessible semiconductor and / or semiconductor board package.

DETAILED DESCRIPTION OF THE INVENTION There may be several ways by which the polymer chains of the thermally reprocessible crosslinked resin can be produced. The thermally reprocessable crosslinked resin can be produced by reacting at least one dienophile having a functionality greater than one and at least one polymer containing furan substituted with 2,5-dialkyl, connecting one to the other via the Diels-Alder addition. In one embodiment the furan groups substituted with 2,5-dialkyl are attached to or form part of the polymer chains. The reversible reaction of furan to dienophile to form the Diels-Alder adduct can be represented by: FURANO DIENOFILO SUBSTITUTED ADULT OF WITH 2.5-DIALS DIALS-ALDER where Y is any of C < or N- For a thermally reprocessible crosslinked resin, all or a portion of the Diels-Alder adduct can be reverted to the furan and the dienophile with heating, such that the resin is a liquid (flowable material). A crosslinking agent that contains two or more dienophiles in its molecular structure can also be used in this embodiment. These dienophiles are connected to each other by chemical bonds or bridge groups. Accordingly, the present invention also contemplates an insert adhesive adhesive composition containing a polymer comprising portions of a furan substituted with 2,5-dialkyl and a crosslinking agent comprising two or more dienophiles in its molecular structure. Dienophiles may also be linked to being part of the polymer chains. The crosslinking agent comprising in its molecular structure two or more furan groups substituted with 2,5-dialkyl can also be used. In yet another embodiment, the dienophile is attached to the polymer chains to which the furan groups substituted with 2,5-dialkyl are also attached or containing the furan groups substituted with 2,5-dialkyl as a part of their chains. polymer. Accordingly, the furan-containing polymer substituted with 2,5-dialkyl can also contain portions of a furan substituted with 2,5-dialkyl and portions of a dienophile. Furans substituted with 2,5-dialkyl may or may not be substituted at their 3 and 4 positions. Preferred substituents are inert substituents such as for example alkyl or alkyloxy groups, typically having up to 10 carbon atoms, such as methyl groups , ethyl, 1-propyl, methoxy and 1-hexyloxy. Resins containing furans whose positions 2 and 5 are not substituted are susceptible to side reactions that can cause irreversible gelation and interfere with their reversibility.

The furan groups substituted with 2,5-dialkyl can be attached to the polymer chains of the polymer or polymers on which the crosslinked resin is based. They can be attached to it directly via a chemical bond or via a divalent organic bridge group for which any of the furan substituents or the 3 or 4 positions of the furans can function as the point of attachment. The alkyl substituents at positions 2 and 5 of the furans can be the same or different and will typically have up to 10 carbon atoms. Examples of suitable alkyl groups are methyl, ethyl, 2-propyl and 1-hexyl groups. Examples of suitable furyl groups that can be attached to a polymer chain are the 2,5-dimethyl-3-yl, 2,5-di-ethyl-3-methyl-4-yl, 5-ethylfurfuryl or 5-methyl groups. (1-butyl) furfuryl. The type of polymer chains to which furan groups substituted with 2,5-dialkyl can be attached is not critical. Suitably the polymer chains are chains of a polyolefin, such as polyethene, polypropene, polystyrene, poly (acrylic acid) or a copolymer of ethene and acid or acrylic ester, chains of random or alternating copolymers of monoxide. carbon and olefinically unsaturated compounds (for further processing on such copolymers compare the following), or heteroatom-containing chains, such as polyamide or polyester chains. It is preferred that furans substituted with 2,5-dialkyl form a structural element of the backbone of the polymer itself. In such a case it is particularly preferred that each of the 2,5-dialkyl substituents of the furans are alkylene groups which also form part of the polymer chain and which can or can not be substituted. Such a structure can be produced by furanizing copolymers of carbon monoxide and olefinically unsaturated compounds containing 1, 4-dicarbonylols in their polymer chains, ie converting such 1,4-dicarbonyl entities into furan portions. Alternatively, a furan-containing polymer substituted with 2,5-dialkyl can be produced directly by reacting carbon monoxide and olefinically unsaturated compounds in the presence of a strong acid. The alternating copolymers of carbon monoxide and olefinically unsaturated compounds containing 1, 4-dicarbonylols in their polymer chains. They can be prepared by palladium catalyzed polymerization using the known methods of, for example, EP-A-121965, EP-A-181014 and EP-A-516238. The polymers prepared in this way are alternating copolymers of carbon monoxide and olefinically unsaturated compounds, ie copolymers of which the polymer chains contain the monomer units originating in carbon monoxide (ie carbonyl groups) and the monomer units that originate from the olefinically unsaturated compounds in an alternating arrangement, so that every fourth carbon atom of the polymer chain belongs to a carbonyl group. Alternative carbon monoxide copolymers and olefinically unsaturated compounds containing 1,4-dicarbonyl entities can be random copolymers, ie copolymers of which the polymer chains contain monomer units in a random order. These latter copolymers can be prepared by radical initiated polymerization using the known methods of, for example, US-A-2495286 and US-A-4024326.

The furanization of the carbon monoxide copolymer and olefinically unsaturated compounds can be effected by methods known in the art, for example, by applying phosphorus pentoxide as the dehydrating agent, as described by A. Sen et al. (J. Polym, Science, Part A. Polyra, Chem. 32 (1994) p.8441), or by heating in the presence of a strong acid, such as p-toluenesulfonic acid, as described in US-A-3979373. These methods allow conversion of the 1,4-dicarbonyl portions in the polymer chains to furan portions at a variable conversion level, depending on the selected reaction conditions. It is preferred to employ in the furanization an alternating copolymer of carbon monoxide and olefinically unsaturated compounds, because these have a higher content of 1,4-dicarbonyl groups in the polymer backbone, so that the furanization can be efficiently carried out at a high level of incorporation of furan groups. However, if a low degree of furanization is desired, the conversion of carbonyl groups to furan groups can be kept low.

The copolymers of carbon monoxide and olefinically unsaturated compounds can be based on hydrocarbons such as olefinically unsaturated compounds. It is preferred that the copolymer be based on an olefinically unsaturated hydrocarbon, suitably an α-olefin, in particular an α-olefin having up to 10 carbon atoms. Very suitable are the aliphatic α-olefins, in particular those having from 3 to 6 carbon atoms and more particularly those having a straight carbon chain, such as propene, 1-butene, 1-pentene and 1-hexene. Propene is more preferred. The copolymer can be regregregular or irregular, stereorregular or atactic. A polymer containing furan substituted with 2,5-dialkyl, wherein a polymer based on propene and carbon monoxide are furanized, can be represented by the formula: The precise nature of the dienophile from which the Diels-Alder adduct is obtained is not critical, since the Diels-Alder adduct has such thermal stability that the crosslinked resin is reprocessible. Usually the minimum temperature above which reprocessed crosslinked resin will be reprocessed depends on the maximum temperature requirements for the semiconductor device used. The reprocessing is suitably carried out at a temperature of 100 ° C, preferably from 130 ° C to 250 ° C, preferably at 200 ° C. The proper functionality of the dienophile can be represented by Y = Y, where Y is any of C < or N-, or -C == C-. Preferably the dienophiles are, for example, alkynes having electron attracting groups attached to both sides of the ethyne portion, such as the ester and keto groups. Examples are the mono- and diesters of butindioic acid (ie acetylene dicarboxylic acid) and substituted but-2-in-l, 4-diones. Other suitable dienophiles are compounds containing a portion of but-2-en-1,4-dione included in a 5- or 6-membered ring, in particular the compounds of the general formula: > __ = C TC = O where X means 0, S, N-, P- or -R-, where R is alkylene, where at least one of the free valences is occupied by a bridge group connecting the dienophile with one of the polymer chains or with another dienophile, and wherein the remaining valencies, if any, are occupied by substituents of lower alkyl or acyl or, preferably, hydrogen. The lower alkyl substituents suitably contain up to 4 carbon atoms and are, for example, methyl or ethyl groups. The dienophiles of this general formula are preferably cyclic derivatives of maleic anhydride and, in particular, maleimide (ie X means 0 or, in particular, N-). Examples of other suitable dienophiles include, bis (triazolinediones), bis (phthalazindiones), quinones, bis (tricyanoethylenes), bis (azodicarboxylates); di-acrylates, maleate or fumarate polyesters, acetylene dicarboxylate polyesters. As indicated in the foregoing, in one embodiment, a crosslinking agent is used which comprises in its molecular structure two or more dienophiles from which the Diels-Alder adducts are obtainable. The dienophiles can be connected to each other by one or more bridge groups. For example, three dienophiles can be connected together by a group of trivalent bridges. However, it is sufficient that a crosslinking agent is used in which two dienophiles are connected to each other by a bivalent bridge group. Dienophiles can also be connected to each other by chemical bonds. Both the molecular weight and the chemical nature of the bridging group of the crosslinking agent can be varied to a high degree. It has been found that such variations of the crosslinking agent give rise to re-moldable crosslinked resins that cover a wide range. of mechanical properties. The bridge group may contain only carbon atoms in the bridge, but it may also contain heteroatoms in the bridge, such as oxygen, silicon or nitrogen atoms. The bridge group ... can be flexible or rigid. For example, polymer bridge groups that have flexible polymer chains, such as poly (alkylene oxide) or polysiloxanes, which have an average molecular weight of number, say, more than 300, provide reprocessable cross-linked resins similar to rubber. When the polymeric flexible chain has a number average molecular weight in the order of 1500-5000 or more, reprocessable crosslinked resins which could replace the thermoplastic rubbers can be obtained. Accordingly, suitable crosslinking agents of this class are poly (alkylene oxide) s crowned with bis-maleimido, such as poly (ethylene oxide) or poly (propylene oxide) s, and polysiloxanes crowned with bismaleiido, for example the bismaleimides of polysiloxanes of the general formula H2N-CH2 [-0-SiR2] n- 0 -CH2-NH2, wherein n is an integer number, on average, of more than 10 and in particular in the range of 20 -70, and each R is independently an alkyl group, in particular having up to 5 carbon atoms, preferably a methyl group. Very good results can be obtained with the bismaleimide of poly (propene oxide) capped with bisamine, in particular having a number average molecular weight of at least 300, more in particular in the range of 1500-5000.

Low molecular weight bridging groups can also be used, i.e. bridging groups that typically have up to 20 carbon atoms in the bridge. The cycloaliphatic and aromatic bridge groups become rigid to the bridge groups. Low molecular weight cycloaliphatic and aromatic bridge groups tend to provide re-moldable cross-linked resins that are hard and brittle, and have a relatively high glass transition temperature. Examples of low cycloaliphatic and aromatic molecular weight bridge groups are groups containing a norbornane skeleton in the bridge, groups 1, 3-phenylene and groups of the following formulas: -f-CH2-f-, -fOfOf-, -f-0-f-S02-fOf and -fC (CH3) 2 ~ f- / where - f- means a 1,4-phenylene group. Other suitable bridge groups are the alkylene and oxycarbonyl (ester) groups and combinations thereof. Suitable low molecular weight crosslinking agents are, for example, the bismaleimides of hydrazine, 2,4-dia inotoluene, hexamethylenediamine, dodecamethylenediamine, diamines of the general formula: and (poly) siloxanes capped with low molecular weight bisamino, such as polysiloxanes of the general formula H2N-CH2 [-0-SiR2] n-0-CH2-NH2, wherein n is in the range, on average, from 1 to 10, preferably from 1 to 5 and the groups r are preferably methyl groups. A mixture of isomers of the diamines of the above formula is commercially available from HOECHST. Very good results can be obtained with bis (4-maleimidophenyl) ethane and dimethylbis [(N-maleimidomethyl) oxy] silane. Other suitable crosslinking agents on the basis of maleic anhydride are the compounds of the general formula: wherein A means a bridge group described in the above, in particular a bridge group having up to 20 carbon atoms in the bridge. More particularly, bridge group A is an alkylene group, such as a hex ethylene group, or groups -D-O-CO- or -CO-O-D-O-CO-, wherein D means a bivalent hydrocarbyl group, for example an alkylene group, such as a hexamethylene group. Again other suitable crosslinking agents are polyesters based on butindioic acid and a diol, such as ethylene glycol, a poly (ethylene glycol), propylene glycol or a poly (propylene glycol). These polyesters can be low molecular weight crosslinking agents, such as those described above, or they can have a number average molecular weight of, for example, more than 400, such as in e.1 range of 2000-6000. The present invention also relates to crosslinking agents such as poly (alkylene oxide) s crowned with bis-alyimido, in particular poly (pyoeopene oxide) s crowned with bismaleimido. Such agents have a number average molecular weight of at least 300, preferably in the range of 1500-5000. The bismaleimides of the polysiloxanes have the general formula H2N-CH2 [-0-SiR2] n_0-CH2-NH2, wherein n is an integer of at least 1 and each R is independently an alkyl group, in particular having up to 5 carbon atoms, preferably a methyl group. The polysiloxanes capped with bismaleimido can be prepared by N-hydroxy-methylation of the maleimide with formaldehyde and subsequent reaction with the appropriate dichlorodialkylsilane in the presence of a base and water using generally known methods. As noted in the foregoing, certain embodiments relate to a crosslinking agent comprising in its molecular structure portions of 2,5-dialkylfuran. In this crosslinking agent, the furan groups substituted with 2,5-dialkyl can be connected together via a chemical bond or via a bridge group. The nature of this bridge group is generally the same as the bridge group of the crosslinking agents comprising two or more dienophiles, as described above. Examples of suitable crosslinking agents are bis (5-ethylfurfuryl) adipate and (5-ethylfurfuryl) acetic acid bis-amines and the diamines mentioned in the preceding paragraphs. The furan portions substituted with 2,5-dialkyl and / or portions of a dienophile may be connected to the polymer chains by means of a chemical bond or by means of a bridge group. This bridge group can be of the same type as the bridge groups of the crosslinking agents. Examples can be given as follows. When the polymer is a polystyrene, the maleimide, like the dienophile, can be bound thereto by alkylation catalyzed by tin (IV) chloride of the polystyrene with N-chloromethylmaleimide, and when the polymer is a copolymer of (styrene / maleic anhydride) , a 5-ethylfurfuryl group can be attached thereto by esterifying the styrene / maleic anhydride copolymer with 5-ethylfurfuryl alcohol in pyridine. When the polymer is a copolymer of carbon monoxide and olefinically unsaturated compounds comprising 1,4-dicarbonyl entities in their polymer chains, the 2, 5-dialkylfurans and the dienophiles can be attached thereto by reacting the copolymer with an appropriately substituted primary hydrocarbylamine, for example, using the known methods of US-A-3979374. In this reaction, the 1,4-dicarbonyl entities are converted into pyrrole entities that are part of the polymer chain and which are N-substituted with the substituted hydrocarbyl group. For example, a copolymer of carbon monoxide and olefinically unsaturated compounds, comprising 1,4-dicarbonyl entities can be made reacting with the monoamide of maleic acid and hexamethylenediamine or with the monoamide of maleic acid and bis (4-aminophenyl) methane, followed by ring closure of the acid-amide portions to maleimide portions. This will provide a polymer having N- (6-maleimidohexyl) pyrrole or N- entities. { 4- [(4'-maleimidophenyl) methyl] phenyl} pyrrole in the polymer chain. When it is desired to use a polymer containing portions of furan substituted by 2,5-dialkyl and portions of a dienophile portion of the 1-dicarbonyl entities of a copolymer of carbon monoxide and olefinically unsaturated compounds it can be converted into portions of furan and another portion of 1,4-dicarbonyl entities can be converted to N-substituted pyrrole entities, of which the N-substituent comprises a dienophile. The molecular weight of the polymer or polymers on which the reprocessed crosslinked resin is based can vary between wide limits. Suitably the polymer or polymers have a number average molecular weight in the range of at least 500, preferably 700, to 30,000, preferably 20,000.

The amount of Diels-Alder adducts present in the thermally reprocessible crosslinked resin depends on the amount of furan groups with 2,5-dialkyl and the amount of the dienophile present in the composition from which the Diels-Alder adducts are formed. . One skilled in the art will appreciate that it is necessary that a certain minimum amount of Diels-Alder adducts be present for the effect that the crosslinked resin is a solid material below the temperature at which the Diels-Alder adducts are reversed to the furan substituted with 2,5-dialkyl and • the dienophile. It will also be appreciated that this minimum amount depends on the molecular weight and type of the polymer on which the resin is based and, if any cross-linking agent is used, on the number of dienophiles or furan groups substituted with 2,5-dialkyl per molecule (ie, functionality) of the crosslinking agent. Low molecular weights of the polymer will require a greater amount of Diels-Alder adducts. The number of Diels-Alder adducts may be lower when a crosslinking agent having higher functionality is used. Generally good results can be achieved by using the furan-containing polymer substituted with 2,5-dialkyl having a ratio of furan groups to ketone groups from 1:16 to 4: 1. The molar ratio of the furan groups substituted with 2,5-dialkyl to amounts of dienophiles typically from 10: 1 to 1: 5, preferably from 5: 1 to 1: 3.

DRIVER MATERIAL To impart thermal or electrical conductivity to the adhesive, an effective amount of a thermally or electrically conductive material is incorporated into the adhesive-bonding adhesive composition. The preferred thermally conductive material is such as, for example, beryllium, boron nitride, aluminum oxide (single crystal), copper-coated aluminum nitride (see U.S. Patent No. 5,288,769) and the like. The electrical contact is provided by means of incorporating electrically conductive materials (fillers) such as silver, nickel, copper or aluminum particles as well as alloys of such metals in the insert-adhesive formulation. Both powder and flake forms of the conductive material can be used in the insert-paste paste compositions. A preferred amount of thermally conductive material and / or electrically is in the range from 60, preferably from 70, to 90, preferably to 80 percent by weight of the total insert adhesive composition, although smaller and larger amounts may be used.

PLATE BINDING ADHESIVES The thermally reprocessable insert attachment means that the device can be removed from a substrate by blending the insert (or adhesive) composition by heating. The insert-binding composition is liquefied when the composition is flowable. The device can be removed without cutting or using excessive force. The thermally reprocessable insert attachment composition of the invention contains (a) a thermally reprocessable crosslinked resin produced by reacting a dienophile having a functionality greater than one and a polymer containing furan substituted with 2,5-dialkyl, and (b) at least one thermally and / or electrically conductive material present in an effective amount of up to 90% by weight of the insert composition, to provide a conductive medium.

The thermally reprocessable insert-binding composition can be processed and / or reprocessed at a temperature where the insert-binding composition melts. Typically, the thermally reprocessible insert-bonding adhesive can be processed and / or reprocessed at a temperature within the range of 100 ° C, preferably 130 ° C, 250 ° C, preferably 200 ° C. If the composition is heated for a prolonged period at a high temperature, for example, for 12 hours at 200 ° C, the composition undergoes irreversible crosslinking and is no longer thermally reprocessable. The thermally reprocessable insert-adhesive composition or adhesive may also contain other additives such as ion scavengers (eg tricalcium phosphate), free radical inhibitors (eg hydroquinone, phenothiazine), elastomeric modifiers (eg silicones) and other additives. conventional adhesives used in the insert adhesives. For a longer reprocessing time, it is preferable to use ion scavengers and / or free radical inhibitors.

A process for attaching a semiconductor device to a substrate is also provided, comprising: (a) providing the substrate; (b) applying to the substrate a thermally reprocessible insert-bonding adhesive composition comprising: (i) a thermally reprocessable crosslinked resin produced by reacting at least one dienophile having a functionality greater than one and at least one polymer containing furan substituted with 2, 5-dialkyl, and (ii) at least one thermally and / or electrically conductive material present in an effective amount of up to 90% by weight of the composition, of insert-bonding, to provide a conductive medium, to a a temperature that is high enough to convert the insert adhesive adhesive composition into a liquid, thereby producing a substrate bonded by adhesive; (c) attaching the semiconductor device on the surface of the thermally reprocessable insert-bonding adhesive on the bonded substrate. adhesive while the adhesive is a liquid, thereby attaching the semiconductor device to the substrate; Y (d) cooling the thermally reprocessible insert-bonding adhesive to provide an assembly. The semiconductor device can be placed on the adhesive prior to substantial cooling by time or by heating to maintain or re-liquefy the adhesive to be a flowable material. The insert-binding composition can be applied to the substrate using standard equipment such as a syringe or a static mixer that mixes the components of the insert-binding composition and accurately applies the composition to the substrate. The semiconductor devices may be attached to various substrates such as, for example, various metal, ceramic or laminate substrates including printed circuit boards (PCB) for example chip-on-board; to conductive frames that are then molded by transferring resin into packages such as electronic component plastic capsules (DIP) and quadrangular flat plastic capsules (PQFP); and other packing configurations such as the ball grid system (BGA). The repair and Reprocessing of defective devices is becoming increasingly important for insert-bonding adhesives. Multiple chip modules (MCMs) use existing packaging technology, the only difference being that a number of uncoated chips are adhesively bonded to a substrate and packaged together. For example, a BGA configuration can have a number of inserts adhesively bonded to a substrate, automated ribbon attachment to make the insert connection to the substrate, an encapsulant that covers all the inserts as a package, and welding spheres that make the connection to the substrate of printed circuits from the BGA substrate. When the space between the semiconductor device and nearby components such as other semiconductor devices becomes smaller, repair and reprocessing without damage to adjacent devices becomes extremely difficult. A thermally reprocessible plate-bonding adhesive of this invention allows the user to easily perform repair and reprocessing on closely spaced devices and high density substrates.

The thermally reprocessable insert-bonding adhesive composition attached to a semiconductor device on one side and to a substrate on another side can be reprocessed by steps comprising: (a) heating the insert-bonding adhesive composition, the composition comprising: i) a thermally reprocessable crosslinked resin produced by reacting a dienophile having a functionality greater than one and a polymer containing furan substituted with 2,5-dialkyl, and (ii) at least one thermally or electrically conductive material, present in an amount effective up to 90% by weight of the insert-binding composition to provide a conductive medium, at a temperature that is sufficiently high to convert the insert-bonding adhesive composition into a liquid, thereby providing a bonding adhesive composition a liquid insert; (b) removing the semiconductor device from the liquid insert attachment adhesive composition; (c) optionally, applying a recent thermally reprocessable insert-bonding adhesive composition, the composition comprising: (i) a thermally reprocessable crosslinked resin produced by reacting a dienophile having a functionality greater than one and a furan-containing polymer substituted with 2,5-dialkyl, and (ii) at least one thermally or electrically conductive material, present in an effective amount of up to 90% by weight of the insert-binding composition to provide a conductive medium; (d) optionally, providing another semiconductor device on the surface of the liquid insert-bonding adhesive, thereby attaching another semiconductor device on the insert-bonding adhesive; and (e) cooling the liquid insert adhesive to a temperature that is sufficiently low to solidify the resin. The insert-bonding adhesive composition can be post-curing to improve the thermal and mechanical bonding properties to the insert (e.g., glass transition temperature and mechanical resistance). To preserve the thermal reproducibility of the crosslinked resin, the insert adhesive adhesive can be heated to a temperature within the range of 70 ° C, preferably 90 ° C, 200 ° C, preferably 160 ° C for a period of time of up to 4 hours. If thermal re-processability is not required, the insert-adhesive composition can be post-cured at a temperature in the range of 150 ° C, preferably 180 ° C, 300 ° C, preferably 250 ° C period of time of up to 4 hours, to improve the thermal properties.

Illustrative Modality * • "The following illustrative embodiments describe the novel epoxy resin composition of the invention and are provided for illustrative purposes and are not to be construed as limiting the invention.

Example 1 An autoclave was charged with methanol and propene (approximately 2: 1 ratio by weight), heated to 90 ° C, and then charged with carbon monoxide at a pressure of 73.4 kg / cm2 (72 bar). A solution of catalyst of palladium acetate, 1,3-bis (diethylphosphino) propane, trifluoromethanesulfonic acid, in a weight ratio of 0.6: 0.62: 1 and 0.3 pyridine, in a solution of tetrahydrofuran and methanol (volume ratio 15: 1) they were injected and the reactor pressure was kept constant at 73.4 kg / cm2 (72 bar) during the reaction by means of a continuous supply of carbon monoxide. Removal of the solvent provided an alternating propene / CO copolymer with an average number-average molecular weight of 733.

Example 2 The alternating propene-CO copolymer with a number average molecular weight of 733 prepared in Example 1 was dissolved in toluene and cyclized in the presence of a catalytic amount of p-toluenesulfonic acid by heating under reflux. The resulting polymer was analyzed by 13 C NMR, which showed that 82% of the ketones in the starting polyketone were cyclized to furans (furan: ketone ratio of 2.28: 1) by the appearance of 13 C NMR signals (resonance of furan) centered at around 107, 114, 147 and 15_ ppm.

Example 3 A system was made by mixing the furanized polyketone made in Example 2 and a stoichiometric amount of bismaleimide of toluenediamine (Compimide Resin TDAB, Technochemie Gmbh) at 171 ° C (340 ° F). The mixture was removed from the gel plate and stored at room temperature. A 8-layer printed circuit board of masked welding (epoxy resin-glass) was placed on the gel plate at 171 ° C (340 ° F) and allowed to warm to that temperature. The mixed system was applied on the board and a silica chip was placed on top of the system and allowed to adhere to the board. The board was removed from the gel plate and allowed to cool to room temperature. The plate remained adhesively bonded to the board when the system formed a cross-linked solid at room temperature. The board was reintroduced back to the hot gel plate and allowed to warm up for one minute. The chip was easily removed from the board when the adhesive system was reversed back to its non-crosslinked liquid state. The chip was reattached on the board in its original place by means of the adhesive film that was still present.

Example 4 An alternating olefin-CO copolymer (27% ethylene, 73% propylene) with a number average molecular weight of 1472 was prepared in a manner similar to Example 1 from propene and ethylene. The copolymer was dissolved in toluene and cyclized in the presence of a catalytic amount of p-toluenesulfonic acid by heating under reflux. The resulting polymer was analyzed by 13 C NMR, which showed that 56% of the ketones in the starting polyketone were cyclized to furans (ratio of furan: ketone 0.64: 1).

Example 5 A gel plate was fixed at 171 ° C (340 ° F) and the furanized polyketone made in Example 4 was applied on the plate. A stoichiometric amount of TDAB was mixed with the furanized polyketone until a homogenous mixture was obtained. The mixture was removed from the gel plate and stored at room temperature.

Example 6 An ICI cone and plate viscometer was set at a temperature of 175 ° C and allowed to equilibrate to the set point. A small amount of mixture of Example 5 was placed on the plate and allowed to reach this temperature. The cone was lowered and rotated to obtain a good film between the cone and the plate. This was verified by raising the cone to check the good formation of the film. Subsequently the mixture was allowed to equilibrate for 90 seconds and two viscosity readings were taken while the cone was rotating at a fixed speed. The cone was raised and the mixture recovered from both the cone and the plate. The mixture was allowed to cool to room temperature to give a cross-linked solid. The sequence of previous events is the charge on the cone and the ICI plate, the measurement of the viscosity at 175 ° C, removal of the mixture, cooling at room temperature, was repeated three times with the same mixture. The three consecutive readings for viscosity were 3-5 poises, 3-5 poises and 3-5 poises. This experiment demonstrates that the mixture can alternate the reversibility between a cross-linked state at room temperature and a non-crosslinked liquid of low viscosity at 175 ° C.

Example 7 An alternating propene-CO copolymer with a number average molecular weight of 1616 is prepared in a manner similar to Example 1, except that 1,3-bis (di-o-methoxyphenylphosphino) -propane was used in the catalyst solution instead of 1,3-bis (diethylphosphino) propane. The copolymer was dissolved in toluene and cyclized in the presence of a catalytic amount of p-toluenesulfonic acid by heating under reflux. The resulting polymer was analyzed by 13 C NMR, which showed that 57% of the ketones in the starting polyketone were cyclized to furans (furan: ketone ratio of 0.66: 1).

Example 8 A gel plate was fixed at 171 ° C (340 ° F) and the furanized polyketone made in Example 7 was applied on the plate. A stoichiometric amount of methylenedianiline bismaleimide (Compimide Resin MDAB, Technochemie Gmbh) and 0.2 moles of phenothiazine (Phenothiazine, Aldrich Chemical) per mole of MDAB were mixed with the furanized polyketone until a homogeneous mixture was obtained. The mixture was then removed and stored at room temperature. A small portion of the mixture was placed on the gel plate at 171 ° C (340 ° F) and mixed with 60% by weight of silver powder (Silver powder, ~ 325 mesh, Johnson Matthey). The components were mixed and the The mixture was then removed and stored at room temperature.

Example 9 An ICI cone and plate viscometer was set at a temperature of 175 ° C and allowed to equilibrate to the set point. A small amount of mixture of Example 8 was placed on the plate and allowed to reach the temperature. The cone was lowered and rotated to obtain a good film between the cone and the plate. This was verified by raising the cone to check the good formation of the film. Subsequently, the mixture was allowed to equilibrate for 90 seconds and two viscosity readings were taken while the cone was rotating at a fixed speed. The cone was raised and the mixture recovered from both the cone and the plate. The mixture was allowed to cool to a cross-linked solid at room temperature. The sequence of events above, ie the load on the cone and ICI plate, the measurement of the viscosity at 175 ° C, removal of the mixture, cooling at room temperature was repeated three times with the same mixture. The three consecutive readings for viscosity were 70-75 poises, 75-80 poises and 75-80 poises. East experiment shows that the mixture can alternate between a cross-linked state at room temperature and a non-crosslinked liquid at 175 ° C.

Example 10 An 8-layer printed circuit board (Epoxy resin-glass) with the masked weld was placed on the gel plate at 171 ° C (340 ° F) and allowed to warm to temperature. The silver-filled system of Example 8 was applied on the board and a silicon chip was placed on top of the system and allowed to adhere to the board. The board was removed from the gel plate and allowed to cool to room temperature. The insert remained adhesively bonded to the board when the system formed a cross-linked solid at room temperature. The board was reinserted back into the hot gel plate and allowed to warm up for one minute. The chip was easily removed from the board when the adhesive system was returned back to its non-crosslinked liquid state. The chip was reattached on the board in its original place by means of the adhesive film that was still present, and the board was removed from the gel plate and cooled to room temperature. This sequence was repeated two times more, that is, place the board back on the hot surface, remove the chip, reattach the chip to the board, and cool to room temperature.

Example 11 The furanized polyketone made in Example 7 and a stoichiometric amount of TDAB together with 6.5% by weight of phenothiazine were heated to 180 ° C, mixed and poured into a 3.2 mm metal mold (1/8 of inch) thick. The mold was quickly cooled and the resulting molding was tested to determine its properties. It was found that the flexural modulus of the sample was 44 kg / cm2 (43 bar (628 psi), a value similar to that of a cross-linked epoxy resin made with an epoxy bisphenol-A resin cured with an anhydride hardener. dielectric and the dissipation factor were 3.17 and 0.013 respectively.

Example 12 The furanized polyketone made in Example 7 was reacted with a 2: 1 stoichiometric ratio of MDAB, 0.1 moles of phenothiazine / mole of MDAB and 0.015 grams of 2-ethylhexanoic acid / gram of furanized polyketone. A sweep was performed Differential scanning calorimetry on the sample, at a gradient speed of 20 ° C / minute. The start of vitreous transition temperature occurred at 105 ° C.

Example 13 The furanized polyketone made in Example 4 was reacted with a stoichiometric amount of TDAB and 0.1 moles of phenothiazine / mole of TDAB on a gel plate at 171 ° C (340 ° F). This sample was ground and placed in a Parr pump with water in a 10: 1 ratio (sample water). The Parr pump was maintained at 60 ° C for 20 hours and the water extract was analyzed to determine the ions by ion chromatography. The extract contained 14 ppm acetate, < 3 ppm glycolate, formate, propionate, < 0.25 ppm chlorine, < 1 ppm of nitrate, 1.7 ppm of sulfate, 4.8 ppm of sodium, 0.8 ppm of magnesium, 2.5 ppm of calcium and 0.2 ppm of ammonium ion. 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 (10)

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

1. A thermally reprocessable insert-bonding adhesive composition, characterized in that it comprises: (a) a thermally reprocessable crosslinked resin, produced by reacting at least one dienophile having a functionality greater than one and at least one polymer containing furan substituted with 2, 5-dialkyl, and (b) at least one thermally and / or electrically conductive material, present in an effective amount in the range of from 60 to 90% by weight of the insert-binding composition, to provide a conductive medium.

2. The thermally reprocessable insert-bonding adhesive composition according to claim 1, characterized in that the crosslinked resin is reprocessible at a temperature within the range of 100 ° C to 250 ° C.

3. The thermally reprocessable insert-adhesive adhesive composition according to claim 1, characterized in that the dienophile is an alkyne having electron attracting groups attached on either side of a portion of ethyne, or a cyclic derivative of maleic anhydride.

4. The thermally reprocessable insert-adhesive adhesive composition according to claim 3, characterized in that the dienophile is selected from the group consisting of compounds containing portions of but-2-en-1,4-dione in 5-membered rings, and compounds containing portions of but-2-en-1,4-diene in 6-membered rings.

5. The thermally reprocessable insert-bonding adhesive composition according to claim 3, characterized in that the thermally reprocessable resin further comprises a residue of a crosslinking agent selected from the group consisting of poly (alkylene oxide) s topped with bismaleimido, polysiloxanes crowned with bismaleimido, hydrazine bismaleimides, 2,4-diamino- toluene, hexamethylenediamine, dodecamethylenediamine, and substituted and unsubstituted diamines of the formula:

6. The thermally reprocessable insert-adhesive adhesive composition according to claim 1 or 2, characterized in that the furan-containing polymer substituted with 2,5-dialkyl is produced by reacting carbon monoxide with at least one olefinically unsaturated compound.

7. The thermally reprocessable insert-adhesive adhesive composition according to claim 1 or 2, characterized in that the furan groups substituted with 2,5-dialkyl in the furan-containing polymer substituted with 2,5-dialkyl and the dienophiles are combined in a molar ratio from 10: 1 to 1: 5.

8. The thermally reprocessible insert-bonding adhesive composition according to claim 1 or 2, further characterized in that comprises (a) a free radical inhibitor and / or an ion scavenger.

9. A process for joining a semiconductor device to a substrate, characterized in that it comprises: (a) providing the substrate; (b) applying, on at least a portion of the substrate, a thermally reprocessable insert-bonding adhesive composition, the composition comprising: (i) a thermally reprocessable cross-linked resin produced by reacting at least one dienophile having a functionality greater than one and at least one furan-containing polymer substituted with 2,5-dialkyl, and (ii) at least one thermally and / or electrically conductive material present in an effective amount in the range of from 60 to 90% by weight of the binding composition. to insert, to provide a conductive medium, at a temperature that is high enough to convert the adhesive-insert adhesive composition into a liquid, thereby producing a substrate bonded by adhesive; (c) attaching the semiconductor device on the surface of the thermally reprocessible insert-bonding adhesive on the substrate bonded by adhesive while the adhesive is a liquid, thereby attaching the semiconductor device to the substrate; Y (d) cooling the insert-bonding adhesive to a temperature that is sufficiently low to solidify the resin, thereby providing a mounting.

10. The process according to claim 9, further characterized by comprising the steps of: (e) heating the thermally reprocessible insert attachment adhesive composition of the assembly to a temperature that is high enough to convert the adhesive bonding composition to the insert in a liquid, thereby providing a liquid insert adhesive adhesive composition; (f) removing the semiconductor device from the liquid insert attachment adhesive composition; (g) optionally, applying a recent thermally reprocessable insert-bonding adhesive composition comprising: (i) a thermally reprocessable crosslinked resin produced by reacting a dienophile having a functionality greater than one and a polymer containing furan substituted with 2, 5-dialkyl, and (ii) at least one thermally or electrically conductive material present in an effective amount in the range of from 60 to 90% by weight of the insert-binding composition, to provide a conductive medium; (h) optionally, providing another semiconductor device on the surface of the liquid insert bonding adhesive, thereby joining another semiconductor device on the insert bonding adhesive; and (i) cooling the liquid insert adhesive to a temperature that is sufficiently low to solidify the resin, thereby providing a reprocessed assembly.