CN1317350C - B-stageable die attach adhesives - Google Patents

Abstract

The present invention relates to b-stageable die attach adhesives, methods of preparing such adhesives, methods of applying such adhesives to the die and other substrate surfaces, and assemblies prepared therewith for connecting microelectronic circuitry. The adhesive comprises a) a solid component heat-curable at a first temperature, b) a liquid component, which is either heat-curable at a second temperature or curable upon exposure to radiation in the electromagnetic spectrum, and c) a heat cure catalyst for the solid curable component.

Description

B-Stage Small Chip Bonding Adhesive

data related to the application

Pursuant to 35 U.S.C. §119(e), this application claims the priority filing date of U.S. Provisional Application No. 60/428,724, filed November 25, 2002, the disclosure of which is incorporated herein by reference.

Background of the invention

field of invention

The present invention relates to b-stage die attach adhesives, methods of making such adhesives, methods of applying such adhesives to die and other substrate surfaces, and die-attached microelectronic circuits prepared therewith components.

A Brief Description of Related Technologies

Bismaleimides occupy an important place in the field of thermosetting resins, and many bismaleimides are commercially available. Bismaleimides have been used to produce moldings and adhesive joints, heat-resistant composites, and high-temperature coatings. Recently, Henkel Loctite Corporation has commercialized a number of products based in part on certain bismaleimides for attaching semiconductor chips to circuit boards, and these products have had good commercial acceptance in the microelectronics industry. These products are covered in one or more of US Patent Nos. 5,789,757 (Husson), 6,034,194 (Dershem), 6,034,195 (Dershem), and 6,187,886 (Husson). It is desirable to provide die attach materials in b-stage form, such as wafer-applied or substrate-applied variations thereof. This variant eliminates many of the storage, distribution, handling and processing problems that have existed when dispensing reactive adhesives in flowable form, including die attach adhesives.

The b-stage pre-applied adhesive itself is not a new commercial object. Henkel Loctite, for example, has a huge business in pre-applied threadlock adhesives used in coupling nut and bolt assemblies involving (meth)acrylate chemistries that can be cured by either a light-cure mechanism, heat-cure mechanism or a combination thereof, and optionally a assisted anaerobic curing mechanism cures. See also US Patent Nos. 2,928,446, 4,325,985, 4,632,944 and 5,300,608.

Additionally, Henkel Loctite has also designed and developed pre-applied underfill capsules (see International Patent Application No. PCT/US00/07494).

However, to date, there is no b-stage heat curable composition based on a combination of liquid and solid curable components, or for commercially manufactured articles, such as semiconductor chips or semiconductor wafers, which have pre-applied thereto such B-Stage Die Attach Adhesive for Microelectronics Packaging or Assembly End User Applications Maintaining Flowable Die Attach Adhesives Without the Need for Intermediate Processing Steps.

Summary of the invention

The present invention relates to b-stage curable compositions comprising a solid component thermally curable at a first temperature; a liquid component curable thermally at a second temperature or when exposed to radiation within the electromagnetic spectrum points; and a thermal curing catalyst for the solid curable component.

The present invention further provides a process for preparing a b-staged thermally curable composition comprising providing a solid component thermally curable at a first temperature, thermally curable at a second temperature or when exposed to a radiation curable liquid component, and a thermal curing catalyst for the solid curable component; and mixing together the solid curable component, liquid curable component, and thermal curing catalyst. The methods herein may further comprise exposing the composition to conditions favorable for curing the liquid curable component, exposing the composition to a temperature sufficient to melt the solid curable component, and exposing the composition to under conditions of temperature sufficient to solidify the molten solid curable component.

The present invention still further provides a method of adhesively bonding a substrate, such as a chip die, to another substrate, such as a circuit board or another chip die, the method comprising applying a composition of the present invention to one of the substrates on; exposing the composition-applied substrate to conditions that advantageously cure the liquid curable component therein to form a b-staged curable film; exposing the b-staged curable film to a temperature sufficient to render the solid curable component therein joining the substrates to form an assembly wherein the substrates are separated by a previously applied composition; and exposing the curable film to a temperature sufficient to cure the molten solid curable component.

Alternatively or additionally, the b-stage heat curable composition may be pre-applied to one or more metallized contact pads on the substrate.

Thermal curing conditions for the b-staged film may include subjecting the assembly to a temperature in the range of about 150°C to about 200°C for a period of about 0.25 minutes to about 2 minutes.

Brief description of the drawings

Figure 1 is a schematic illustration of a semiconductor chip in one embodiment of the invention prior to assembly with a substrate.

FIG. 2 is a schematic diagram of a circuit assembly including the semiconductor chip of FIG. 1 assembled on a substrate.

Fig. 3 is a schematic diagram of a circuit assembly including a semiconductor chip assembled on a chip scale package in a further embodiment of the present invention.

Figure 4 is a schematic diagram of a stacked chip die application.

Detailed description of the invention

As solid thermally curable components, epoxides, episulfides, maleimides, itaconimides and nadimides are especially desirable.

Epoxy resins in the solid state may include monofunctional epoxy compounds: C ₄ -C ₂₈ alkyl glycidyl ethers; C ₂ -C ₂₈ alkyl- and alkenyl glycidyl esters; and C ₁ -C ₂₈ alkane base- and mono-phenol glycidyl ethers; and polyfunctional epoxy compounds: pyrocatechol, resorcinol, hydroquinone, 4,4'-dihydroxydiphenylmethane (or bisphenol F, as commercially available at RE-303-S or RE-404-S from Nippon Kayuku, Japan), 4,4`-dihydroxy-3,3`-dimethyldiphenylmethane, 4,4`-dihydroxydiphenyldimethyl Methane (or bisphenol A), 4,4`-dihydroxydiphenylmethylmethane, 4,4`-dihydroxydiphenylcyclohexane, 4,4`-dihydroxy-3,3`-di Polyglycidyl ethers of methyldiphenylpropane, 4,4`-dihydroxydiphenylsulfone and tris(4-hydroxyphenyl)methane; polyglycidyl ethers of transition metal complexes; Chlorination and bromination products; polyglycidyl ethers of novolaks; polyglycidyl ethers of diphenols obtained by esterification of ethers of diphenols by means of dihaloalkanes or dihaloalkyl groups Obtained by ether esterification of salts of aromatic carboxylic acids; polyglycidyl ethers of polyphenols obtained by condensation of phenols and long-chain halogenated paraffins containing at least two halogen atoms; N,N`-diglycidyl Aniline; N,N`-dimethyl-N,N`-diglycidyl-4,4`-diaminodiphenylmethane; N,N,N`,N`-tetraglycidyl-4,4 `-Diaminodiphenylmethane; N,N`-diglycidyl-4-aminophenyl glycidyl ether; bis-4-aminobenzoic acid N,N,N`,N`-tetraglycidyl-1 , 3-propylene ester; novolak epoxy resin; cresol novolak epoxy resin; and combinations thereof.

Among these solid commercially available epoxy resins, suitable for use in the present invention are polyglycidyl derivatives of phenolic compounds, such as under the trade name EPON, such as EPON 1009F [bisphenol A epoxy resin (CAS No. 25036 -25-3)], EPON 1001F, EPON 1002F, EPON1004F, EPON 1007F, EPON 3001, EPON 3002, EPON 2002, EPON 2003, EPON2004, EPON 2005, EPON 2012, EPON 2014, EPON 2024, and EPON Performance 2042 were obtained from Resolu available from Dow Chemical Co. under the trade designation DER, such as DER 331, DER 332, DER 383, DER 354, and DER 542; ethyl) and (chloromethyl)oxirane (CAS No. 25068-38-6)], ARALDITE ECN 1299 [formaldehyde, polymer with (chloromethyl)oxirane and 2-methylphenol , melting point 85-100°C (CSA No.29690-82-2)] and ARALDITE ECN 1285 [formaldehyde, polymer with (chloromethyl) oxirane and 2-methylphenol, melting point 80-90°C ( CSA No.29690-82-2)], and ARALDITE GT 7097US [(phenol, 4-(1,1-dimethylethyl), with (chloromethyl)oxirane and 4,4`-bis (1-methylethyleneidene) polymers, melting point 113-123° C. (CAS No. 67924-34-9)) were obtained from Vantico Inc., Brewster, New York; and those obtained as BREN from Nippon Kayaku, Japan . Other suitable epoxy resins include polyepoxides prepared from polyols and the like, and polyglycidyl derivatives of novolac resins, the latter of which are commercially available from Dow Chemical under the tradename DEN, such as DEN431, DEN438 and DEN439. Company.

Polyglycidyl adducts of amines, amino alcohols and polycarboxylic acids are also useful in the present invention, commercially available resins of which include GLYAMINE 135, GLYAMINE 125 and GLYAMINE 115 available from BP Chemicals, LTD; ARALDITE MY available from Vantico Inc. 720, ARALDITE MY721, ARALDITE MY0500, and ARALDITE MY0510.

Of course, combinations of different epoxy resins are also desirable for this application.

In addition to epoxides, episulfides are also desirable, whether they are total or partial episulfides, provided they are in the solid state. Episulfides are either commercially available or readily prepared from the corresponding epoxy by known synthetic methods.

Solid-state maleimides, endomethylenetetrahydrophthalimides, and itaconimides include those compounds having the following structures I, II, and III, respectively:

in:

m=1-15,

p=0-15,

each R ^is independently selected from hydrogen or lower alkyl, and

J is a monovalent or multivalent moiety containing an organic or organosiloxane group, and combinations of two or more thereof.

More specific representatives of solid-state maleimides, itaconimides, and endomethylenetetrahydrophthalimides include those corresponding to structures I, II, or III, wherein

m=1-6,

p=0,

R ^is independently selected from hydrogen or lower alkyl, and

J is a monovalent or multivalent group selected from hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, substituted heteroatom-containing hydrocarbyl, hydrocarbylene, substituted hydrocarbylene, heteroatom-containing hydrocarbylene, substituted heteroatom-containing Alkylene groups, polysiloxanes, polysiloxane-polyurethane block copolymers, and combinations of two or more thereof, the monovalent or multivalent groups optionally contain one or more linking groups, The linking group is selected from covalent bond, -O-, -S-, -NR-, -OC(O)-, -OC(O)-O-, -OC(O)-NR-, -NR- C(O)-, -NR-C(O)-O-, -NR-C(O)-NR-, -SC(O)-, -SC(O)-O-, -SC(O)- NR-, -S(O)-, -S(O) ₂ -, -OS(O) ₂ -, -OS(O) ₂ -O-, -OS(O) ₂ -NR-, -OS(O )-, -OS(O)-O-, -OS(O)-NR-, O-NR-C(O)-, O-NR-C(O)-O-, -O-NR-C( O)-NR-, -NR-OC(O)-, -NR-OC(O)-O-, -NR-OC(O)-NR-, -O-NR-C(S)-, O- NR-C(S)-O-, O-NR-C(S)-NR-, NR-OC(S)-, -NR-OC(S)-O-, NR-OC(S)-NR- , -OC(S)-, -OC(S)-O-, -OC(S)-NR-, -NR-C(S)-, -NR-C(S)-O-, -NR-C (S)-NR-, -SS(O) ₂ -, -SS(O) ₂ -O-, -SS(O) ₂ -NR-, -NR-OS(O)-, -NR-OS(O )-O-, -NR-OS(O)-NR-, -NR-OS(O) ₂ -, -NR-OS(O) ₂ -O-, -NR-OS(O) ₂ -NR-, -O-NR-S(O)-, -O-NR-S(O)-O-, -O-NR-S(O)-NR-, -O-NR-S(O) ₂ -O- , -O-NR-S(O) ₂ -NR-, -O-NR-S(O) ₂ -, -OP(O)R ₂ -, -SP(O)R ₂ -, NR-P(O )R ₂ -, wherein each R is independently hydrogen, alkyl or substituted alkyl, and combinations of two or more thereof.

As those skilled in the art are readily aware, when one or more of the above-mentioned monovalent or polyvalent groups contain one or more of the above-mentioned linking groups to form maleimide, endomethylene tetra When hydrogenating the side group "J" of phthalimide or itaconimide, various linking groups can be generated, such as oxyalkyl, thioalkyl, aminoalkyl, carboxyalkyl, oxy Alkenyl, thioalkenyl, aminoalkenyl, carboxyalkenyl, oxyalkynyl, thioalkynyl, aminoalkynyl, carboxyalkynyl, oxycycloalkyl, thiocycloalkyl, Aminocycloalkyl, Carboxycycloalkyl, Oxycycloalkenyl, Thiocycloalkenyl, Aminocycloalkenyl, Carboxycycloalkenyl, Heterocycle, Oxyheterocycle, Thioheterocycle, Aminoheterocycle, Carboxy Heterocycle, oxyaryl, thioaryl, aminoaryl, carboxyaryl, heteroaryl, oxyheteroaryl, thioheteroaryl, aminoheteroaryl, carboxyheteroaryl, oxyalkane Aryl, Thioalkaryl, Aminoalkaryl, Carboxyalkaryl, Oxyaralkyl, Thioaralkyl, Aminoaralkyl, Carboxyaralkyl, Oxyarylalkenyl, Sulfur Substituted arylalkenyl, aminoarylalkenyl, carboxyarylalkenyl, oxyalkenylaryl, thioalkenylaryl, aminoalkenylaryl, carboxyalkenylaryl , oxyarylalkynyl, thioarylalkynyl, aminoarylalkynyl, carboxyarylalkynyl, oxyalkylaryl, thioalkyaryl aryl, aminoalkylaryl, or carboxyalkynyl Aryl, oxyalkylene, thioalkylene, aminoalkylene, carboxyalkylene, oxyalkenylene, thioalkenylene, aminoalkenylene, carboxyalkenylene, oxyalkenylene Alkynyl, Thioalkynylene, Aminoalkynylene, Carboxyalkynylene, Oxycycloalkylene, Thiocycloalkylene, Aminocycloalkylene, Carboxycycloalkylene, Oxycycloalkene group, thiocycloalkenylene, aminocycloalkenylene, carboxycycloalkenylene, oxyarylene, thioarylene, aminoarylene, carboxyarylene, oxyalkylarylene , Thioalkylarylene, Aminoalkylarylene, Carboxyalkylarylene, Oxyarylalkylene, Thioarylalkylene, Aminoarylalkylene, Carboxyarylarylylene Alkyl, oxyarylalkenylene, thioarylalkenylene, aminoarylalkenylene, carboxyarylalkenylene, oxyalkenylarylene, thioalkenylarylene , Aminoalkenylarylene, Carboxyalkenylarylene, Oxyarylalkynylene, Thioarylalkynylene, Aminoarylalkynylene, Carboxyarylalkynylene, Oxyalkyne Arylene, thioalkynylarylene, aminoalkynylarylene, carboxyalkynylarylene, heteroarylene, oxyheteroarylene, thioheteroarylene, aminoheteroarylene radical, carboxyheteroarylene, heteroatom-containing di- or polyvalent ring moiety, oxygen-containing heteroatom-containing bi- or polyvalent ring moiety, sulfur-containing heteroatom-containing bi- or polyvalent ring moiety, amino-containing heteroatom Bi- or polyvalent ring moieties, di- or polyvalent ring moieties containing carboxyl heteroatoms, disulfides, sulfonamides, and the like.

In another embodiment, the maleimide, endomethylenetetrahydrophthalimide or itaconimide contemplated for use in the practice of the present invention has structure I, II or III, wherein m = 1-6, p = 0-6, J is selected from saturated linear or branched chain alkyl groups optionally containing optionally substituted aryl moieties as substituents on the alkyl chain or as A portion of the backbone of an alkyl chain, and wherein the alkyl group has up to about 20 carbon atoms;

Siloxanes having the following structure: -(C(R ³ ) ₂ ) _d -[Si(R ⁴ ) ₂ -O] _f -Si(R ⁴ ) ₂ -(C(R ³ ) ₂ ) _e -, -(C(R ³ ) ₂ ) _d -C(R ³ )-C(O)O-(C(R ³ ) ₂ ) _d -[Si(R ⁴ ) ₂ -O] _f -Si(R ⁴ ) ₂ -(C(R ³ ) ₂ ) _e -O(O)C-(C(R ³ ) ₂ ) _e -, or -(C(R ³ ) ₂ ) _d -C(R ³ )-O(O )C-(C(R ³ ) ₂ ) _d -[Si(R ⁴ ) ₂ -O] _f -Si(R ⁴ ) ₂ -(C(R ³ ) ₂ ) _e -C(O)O-(C (R ³ ) ₂ ) _e -, where:

each ^R is independently hydrogen, alkyl or substituted alkyl,

each ^R is independently hydrogen, lower alkyl or aryl,

d=1-10,

e=1-10, and

f=1-50;

Polyoxyalkylene having the following structure:

[(CR ₂ ) _r -O-] _f -(CR ₂ ) _s -

in:

each R is independently hydrogen, alkyl or substituted alkyl,

r=1-10,

s=1-10, and

f is as defined above;

An aryl group having the following structure:

in:

each Ar is a monosubstituted, disubstituted or trisubstituted aromatic or heteroaromatic ring having 3-10 carbon atoms, and

Z is:

Saturated straight chain alkylene or branched chain alkylene optionally containing a saturated ring moiety as a substituent on the alkylene chain or as part of the alkylene chain backbone, or

Polyoxyalkylene having the following structure:

[(CR ₂ ) _r -O-] _q -(CR ₂ ) _s -

in:

each R is independently hydrogen, alkyl or substituted alkyl, r and s are as defined above, and

q falls in the range 1-50;

Di- or tri-substituted aromatic moieties having the structure:

in:

each R is independently hydrogen, alkyl or substituted alkyl,

t falls within the range of 2-10,

u falls in the range 2-10,

Ar is as defined above;

An aryl group having the following structure:

in:

each R is independently hydrogen, alkyl or substituted alkyl,

t=2-10,

k=1, 2 or 3,

g=1 to about 50,

Each Ar is as defined above,

E is -O- or ^-NR5- , wherein ^R5 is hydrogen or lower alkyl; and

W is a linear or branched chain alkyl, alkylene, oxyalkylene, alkenyl, alkenylene, oxyalkenylene, ester or polyester, a siloxane having the following structure:-( C(R ³ ) ₂ ) _d -[Si(R ⁴ ) ₂ -O] _f -Si(R ⁴ ) ₂ -(C(R ³ ) ₂ ) _e -, -(C(R ³ ) ₂ ) _d - C(R ³ )-C(O)O-(C(R ³ ) ₂ ) _d -[Si(R ⁴ ) ₂ -O] _f -Si(R ⁴ ) ₂ -(C(R ³ ) ₂ ) _e -O(O)C-(C(R ³ ) ₂ ) _e -, or -(C(R ³ ) ₂ ) _d -C(R ³ )-O(O)C-(C(R ³ ) ₂ ) _d -[Si(R ⁴ ) ₂ -O] _f -Si(R ⁴ ) ₂ -(C(R ³ ) ₂ ) _e -C(O)O-(C(R ³ ) ₂ ) _e -, where:

each ^R is independently hydrogen, alkyl or substituted alkyl,

each ^R is independently hydrogen, lower alkyl or aryl,

d=1-10,

e=1-10, and

f=1-50; or

A polyoxyalkylene having the following structure, which optionally contains a substituent selected from hydroxyl, alkoxy, carboxyl, nitrile, cycloalkyl or cycloalkenyl:

[(CR ₂ ) _r -O-] _f -(CR ₂ ) _s -

in:

each R is independently hydrogen, alkyl or substituted alkyl,

r=1-10,

s=1-10, and

f is as defined above;

A carbamate group having the following structure:

R ⁷ -UC(O)-NR ⁶ -R ⁸ -NR ⁶ -C(O)-(OR ⁸ -OC(O)-NR ⁶ -R ⁸ -NR ⁶ -C(O)) _v -UR ⁸ -

in:

each ^R is independently hydrogen or lower alkyl,

each R is ^{independently} alkyl, aryl or aralkyl having 1-18 carbon atoms,

each ^R is an alkyl or alkoxy chain having up to about 100 atoms in the chain, optionally substituted by Ar,

U is -O-, -S-, -N(R)-, or -P(L) _1,2- , wherein R is as defined above, and wherein each L is independently =O, =S, -OR or -R; and

V=0-50;

polycyclic alkenyl; or

A mixture of two or more of them.

The maleimide, endomethylenetetrahydrophthalimide and itaconimide containing compounds useful as solid curable components are of course selected so that they are solid and have a melting point of 90°C to 160°C.

Particularly desirable maleimides for use as solid components in the b-staged die attach adhesives of the present invention include, for example, maleimides having the following structure:

As liquid curable components, especially desired are epoxides, episulfides, maleimides, endomethylenetetrahydrophthalimides, itaconimides, (methyl) Acrylates, maleates, fumarates, vinyl ethers, vinyl esters, allylamides, styrene and its derivatives, poly(alkenylene), norbornene, thiolene and analog.

Liquid epoxies useful herein include those also commercially available from Resolution Performance under the tradenames EPON, such as EPON825, EPON826, EPON828, EPON862, EPON8019, EPON8101, EPON8112, EPON813, EPON8131, EPON8132, EPON8133, EPON815C, and EPON824.

For compounds containing maleimide, endomethylenetetrahydrophthalimide and/or itaconimide, if containing maleimide, endomethylenetetrahydrophthalimide The functional group of the compound of dicarboximide and/or itaconimide is respectively connected on the monovalent group J, or is separated by multivalent group J, and each monovalent group or multivalent group has sufficient length and The degree of branching is such that compounds containing maleimide, endomethylenetetrahydrophthalimide and/or itaconimide are liquid, then such compounds are suitable for use as liquid curable components .

In a more specific enumeration of such maleimide, endomethylenetetrahydrophthalimide and/or itaconimide-containing compounds of structures I, II and III, each R independently hydrogen or lower alkyl, -J-includes branched chain alkyl, alkylene or oxyalkylene species having sufficient length and branching to allow maleimide, endomethylene tetrahydrogenation The phthalimide and/or itaconimide compound is liquid, and m is 1, 2 or 3.

Compounds containing maleimide, endomethylenetetrahydrophthalimide, or itaconimide that can be used as the liquid component of the present invention can be selected from US Patent Nos. 5,789,757 (Husson), 6,034,194 (Dershem), 6,034,195 (Dershem), and 6,187,886 (Husson), the disclosures of each of which are incorporated herein by reference, and U.S. Patent Nos. 6,063,828 (Ma), 6,265,530 (Herr), 6,281,314 ( Tong) and 6136566 (Ma), the disclosures of each of which are also incorporated herein by reference.

The (meth)acrylates can be chosen from many different compounds. As used herein, the terms (meth)acrylic acid and (meth)acrylate are used synonymously with respect to monomers and monomer-containing components. The terms (meth)acrylic acid and (meth)acrylate include those of acrylic acid, methacrylic acid, acrylates and methacrylates.

The (meth)acrylate component may include one or more members selected from monomers represented by the following formula:

wherein G is hydrogen, halogen or alkyl having 1-4 carbon atoms, ^R has 1-16 carbon atoms and is alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkaryl, aryl radical or aryl, which is optionally replaced by silane, silicon, oxygen, halogen, carbonyl, hydroxyl, ester, carboxylic acid, urea, urethane, carbamate, amine, amide, sulfur, sulfonate or sulfone replace or insert;

Urethane acrylate or urea acrylate represented by the following formula:

in:

G is hydrogen, halogen or an alkyl group with 1-4 carbon atoms;

^R represents a divalent aliphatic, cycloaliphatic, aromatic or araliphatic group bonded through one or more carbon atoms shown at the -O-atom and -X-atom or group;

X is -O-, -NH- or -N(alkyl)-, wherein the alkyl group has 1-8 carbon atoms;

z is 2-6; and

^R is a z-valent cycloaliphatic, aromatic or araliphatic group bonded to one or more NH groups through one or more carbon atoms; and

Di- or tri-(meth)acrylates selected from the group consisting of polyethylene glycol di(meth)acrylate, bisphenol A di(meth)acrylate, tetrahydrofuran di(meth)acrylate, hexane Glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate or combinations thereof.

Suitable polymerizable (meth)acrylate monomers include triethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, (meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol tetra(meth)acrylate, trimethylol Propane Tri(meth)acrylate, Dipentaerythritol Monohydroxypenta(meth)acrylate, Pentaerythritol Tri(meth)acrylate, Bisphenol A Ethoxylate Di(meth)acrylate, Trimethylolpropane B Oxide Tri(meth)acrylate, Trimethylolpropane Propoxide Tri(meth)acrylate, and Bisphenol A Diepoxide Di(meth)acrylate.

In addition, monofunctional (meth)acrylate monomers can be used, including tetrahydrofuran (meth)acrylate and di(meth)acrylate, citronellyl (meth)acrylate, hydroxypropyl (meth)acrylate esters, tetrahydrodicyclopentadienyl (meth)acrylate, triethylene glycol (meth)acrylate, triethylene glycol (meth)acrylate and combinations thereof.

Of course, (meth)acrylated silicones can also be used, provided that the silicone backbone is not so large as to minimize the effect of the (meth)acrylate when cured.

Other (meth)acrylates suitable for use herein include the low viscosity acrylates disclosed and claimed in US Patent No. 6,211,320 (Dershem), the disclosure of which is expressly incorporated herein by reference.

Fumarates include those having the general structure:

Maleate esters include those containing the general structure:

For each of the fumarate and maleate, R can be selected from ^R1 as defined above.

Vinyl ethers and vinyl esters include those having the general structure:

in

q is 1, 2 or 3,

Each R is independently as defined above for ^R , each Q is independently selected from -O-, -O(O)C-, -C(O)- or -C(O)-O- and

Y is as defined with respect to X in structures I, II and III.

Examples of vinyl ethers and vinyl esters encompassed by the above general structure include stearyl vinyl ether, behenyl vinyl ether or ester, eicosyl vinyl ether or ester, isoeicosane Vinyl ether or ester, isotetradecyl vinyl ether or ester, poly(tetrahydrofuran) divinyl ether or ester, tetraethylene glycol divinyl ether or ester, tri-2,4,6-(1 -vinyloxybutane-)-4-oxyl-1,3,5-triazine, bis-1,3-(1-vinyloxybutane-4-)-oxycarbonylbenzene (or Known as bis(4-vinyloxybutyl)isophthalate; available under the trade designation VECTOMER 4010 from Allied-Signal Inc., Morristown, NJ), through a combination of lower vinyl ethers and higher molecular weight diols Divinyl ether prepared by transvinyl exchange reaction. Particularly desirable divinyl resins include stearyl vinyl ether or esters, behenyl vinyl ethers or esters, eicosyl vinyl ethers or esters, isoeicosyl vinyl ethers or esters, Poly(tetrahydrofuran) divinyl ethers or esters, divinyl ethers prepared by transvinyl ethers between lower vinyl ethers and higher molecular weight glycols.

As an allyl amide, various compounds can be selected, such as those satisfying the "J" listed above for maleimide, endomethylenetetrahydrophthalimide and/or itaconimide those of the guidelines. For example, in a more specific enumeration, those corresponding to the following structures:

in

R' is hydrogen, C ₁ -about C ₁₈ alkyl or oxyalkyl, allyl, aryl or substituted aryl,

m is 1-6, and

X is as defined above for J.

Styrene-containing components include those having the general structure attached to X as defined above:

where n is 1-6.

Norbornenyl moieties include those having the general structure attached to X as defined above:

where m is 1-6.

Thiolene components include those containing the general structure attached to X as defined above:

where m is 1-6.

The first temperature at which the solid component can solidify should be greater than or equal to the temperature (or range of temperatures) at which the solid component melts - that is, changes from a solid state to a liquid state. Generally, this temperature should be in the range of about 100°C to about 300°C, although temperatures above about 100°C are desirable. These different temperature ranges offer the formulator a wide range of possibilities when preparing compositions within the scope of the present invention, particularly where a particular set of physical property parameters is desired or specified.

Thermal curing catalysts may be included in the composition to reduce the temperature at which curing occurs or to enhance the degree of curing when appropriate temperature conditions are selected for curing to occur.

Thermal curing catalysts may be selected from free radical catalysts, anionic curing agents, cationic curing agents and combinations thereof. For example, free radical catalysts may be selected from peroxides, azo compounds, and combinations thereof. Particularly desirable peroxide catalysts include dicumyl peroxide, dibenzoyl peroxide, 2-butanone peroxide, t-butyl perbenzoate, di-t-butyl peroxide, 2,5-bis(t- Butylperoxy)-2,5-dimethylhexane, bis(tert-butylperoxyisopropyl)benzene and tert-butylhydroperoxide, and azo compounds including 2,2`-azobis( 2-methylpropionitrile), 2,2'-azobis(2-methylbutyronitrile), and 1,1'-azobis(cyclohexanenitrile).

Commercially available examples of these free radical catalysts include those marketed by Akzo Nobel, such as the following peroxides diisobutyryl peroxide (CAS No. 3437-84-1), cumyl perneodecanoate (CAS No. 36748 -47-0), peroxydicarbonate mixture (CAS No. 105-64-6; 19910-65-7; 78350-78-4), 2,4,2-trimethyl-2-pentane perneodecanoate Ester (CASNo.51240-95-0), cumyl perneodecanoate (CAS No.68299-16-1), di-sec-butyl perdicarbonate (CAS No.19910-65-7), perneodecanoate Tert-butyl ester (CAS No.26748-41-4), dibutyl percarbonate (CAS No.16215-49-9), dicetyl percarbonate (CASNo.26332-14-5), dibutyl percarbonate Bis(4-tert-butylcyclohexyl) carbonate (CASNo.15520-11-3), bis(2-ethylhexyl) perdicarbonate (CAS No.16111-62-9), dimyristyl perdicarbonate (CAS No.53220-22-7), tert-butyl perpivalate (CASNo.26748-38-9), tert-amyl perpivalate (CAS No.29240-17-3), perpivalic acid Tert-butyl ester (CAS No.927-07-1), di-(3,5,5-trimethylhexanoyl) peroxide (CASNo.3851-87-4), dilauroyl peroxide (CAS No. 105-74-8), dicaprylyl peroxide (CAS No.762-16-3), didecanoyl peroxide (CAS No.762-12-9), 2,5-dimethyl-2,5 - Di(2-ethylhexanoylperoxy)hexane (CAS No. 13052-09-0), tert-amyl peroxy-2-ethylhexanoate (CAS No. 686-31-7), peroxy -2-tert-butyl ethylhexanoate (CASNo.3006-82-4), dibenzoyl peroxide (CAS No.94-36-0), 1,1-di(tert-butylperoxy)- 3,3,5-Trimethylcyclohexane (CAS No.6731-36-8), 2,2-bis[4,4-di-(tert-butylperoxycyclohexyl)propane] (CAS No. 1705-60-8), 1,1-bis(tert-amylperoxy)-cyclohexane (CAS No.15667-10-4), 1,1-bis(tert-butylperoxy)-cyclohexane (CASNo.3006-86-8), tert-amyl peroxy-2-ethylhexyl carbonate (CAS No.70833-40-8), tert-butyl peroxy-3,5,5-trimethylhexanoate (CAS No.13122-18-4), tert-butyl peroxy-2-methylbenzoate (CAS No.22313-62-8), 2,2-di(tert-butylperoxy)butane (CASNo .2167-23-9), tert-butyl peroxyisopropyl carbonate (CAS No.2372-21-6), tert-butyl peroxy 2-ethylhexyl carbonate (CAS No.34443-12-4), tert-amyl perbenzoate (CASNo.4511-39-1), tert-butyl peracetate (CAS No.107-71-1), 4,4-di(tert-butylperoxy)butyl valerate (CAS No.995-33-5), tert-butyl perbenzoate (CAS No.614-45-9), di-tert-amyl peroxide (CAS No.10508-09-5), dicumyl peroxide (CAS No. .80-43-3), bis(tert-butylperoxyisopropyl)benzene (CASNo.25155-25-3), 2,5-dimethyl-2,5-bis(tert-butylperoxy) Hexane (CASNo.78-63-7), tert-butyl cumyl peroxide (CAS No. 3457-61-2), 2,5-dimethyl-2,5-di(tert-butyl peroxy) Hexyne-3 (CAS No.1068-27-5), di-tert-butyl peroxide (CAS No.110-05-4), 3,6,9-triethyl-3,6,9-trimethyl 1,4,7-triperoxonane (CAS No.24748-23-0), 1,1,3,3-tetramethylbutyl hydroperoxide (CAS No.5809-08-5), diisopropyl Benzene monohydroperoxide (CAS No.26762-93-6), cumyl hydroperoxide (CAS No.80-15-9), tert-butyl hydroperoxide (CAS No.75-91-2), and tert-amyl hydroperoxide (CAS No.3425-61-4), and the following azo compound 2,2`-azobis (isobutyronitrile) (CAS No.78-67-1), 2 , 2`-Azobis(2-methylbutyronitrile)(CAS No.13472-08-7) and 1,1`-Azobis(1-cyclohexanenitrile)(CAS No.2094-98-6 ).

Thermal curing catalysts can also be anionic curing agents, such as those broadly described as aza compounds, amine compounds, amide compounds, imidazole compounds, and combinations thereof. More specific examples of aza compounds include:

1,5-Diazabicyclo[4.3.0]non-5-ene

1,8-Diazabicyclo[5.4.0]undec-5-ene(DBU)

1,5,7-Triazabicyclo[4.4.0]dec-5-ene

quinucline

1,4-diazabicyclo[2.2.2]octane

More specific examples of the amine compound include aliphatic polyamines, aromatic polyamines, alicyclic polyamines such as diethylenetriamine, triethylenetetramine, diethylaminopropylamine, benzyldimethylamine, m- Xylylenediamine, diaminodiphenylamine, quinoxaline, isophoronediamine, ethylenementhenediamine, and combinations thereof.

A more specific example of an amide compound is a functionalized amide, dicyandiamide.

More specific examples of imidazole compounds include isoimidazole, imidazole, 2-ethyl-4-methylimidazole, 2,4-dimethylimidazole, butylimidazole, 2-heptadecenyl-4-methylimidazole , 2-methylimidazole, 2-undecenylimidazole, 1-vinyl-2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1 -Benzyl-2-methylimidazole, 1-propyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-guanidinoethyl-2-methylimidazole, addition products of imidazole and methylimidazole, Addition products of imidazole and trimellitic acid, 2-heptadecyl-4-methylimidazole, phenylimidazole, benzylimidazole, 2-methyl-4,5-diphenylimidazole, 2,3 , 5-triphenylimidazole, 2-styryl imidazole, 1-(dodecylbenzyl)-2-methylimidazole, 2-(2-hydroxy-4-tert-butylphenyl)-4, 5-diphenylimidazole, 2-(2-methoxyphenyl)-4,5-diphenylimidazole, 2-(3-hydroxyphenyl)-4,5-diphenylimidazole, 2-( p-Dimethylaminophenyl)-4,5-diphenylimidazole, 2-(2-hydroxyphenyl)-4,5-diphenylimidazole, bis(4,5-diphenyl-2-imidazole )-Benzene-1,4,2-naphthyl-4,5-diphenylimidazole, 1-benzyl-2-methylimidazole, 2-p-methoxystyrylimidazole and combinations thereof.

Thermal curing catalysts can also be cationic curing agents, such as those broadly described as organic acids, anhydrides, and Lewis acids. Organic acids include phenols, thiophenols, mercaptans, carboxylic acids, and combinations thereof. Anhydrides include, inter alia, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, 5-(2,5-dioxytetrahydro)-3-methyl-3-cyclohexene-1,2- Carboxylic anhydrides, and combinations thereof. Lewis acids include various substances known in the art as Lewis acids, examples of which are phosphines, alkyl halides, phosphoric acid esters, boron trifluoride etherates, and the like.

The liquid component is either thermally curable at a second temperature different from the first temperature, or curable when exposed to radiation within the electromagnetic spectrum. The second temperature is often in the range of about 50°C to about 150°C, but desirably has a temperature of less than about 100°C.

As noted above, another thermal curing catalyst may be included in the composition to reduce the temperature at which the liquid component cures or to accelerate the extent to which the liquid component cures when appropriate temperature conditions are selected for curing to occur. Those thermal curing catalysts cited above are suitable as another thermal curing catalyst, provided that they catalyze a reaction of or with a liquid component at a specified temperature.

In cases where it is desirable for some commercial applications to cure the liquid component by exposure to radiation within the electromagnetic spectrum, a photoinitiator should also be included in the composition. Photoinitiators should be selected with regard to the range of radiation within the electromagnetic spectrum that will initiate cure. For example, suitable ranges of radiation within the electromagnetic spectrum include UV, UV/VIS, VIS, IR, electron beam, X-ray, and microwave radiation.

Representative examples of UV and UV/VIS photoinitiators include those commercially available under the trade designations "IRGACURE" and "DAROCUR" from Ciba Specialty Chemicals, Tarrytown, New York, specifically "IRGACURE" 184 (1-hydroxycyclohexylbenzene ketone), 907 (2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one), 369 (2-benzyl-2-N,N- Dimethylamino-1-(4-morpholinophenyl)-1-butanone), 500 (combination of 1-hydroxycyclohexyl phenyl ketone and benzophenone), 651 (2,2-dimethoxy base-2-phenylacetophenone), 1700 (bis(2,6-dimethoxybenzoyl-2,4,4-trimethylpentyl)phosphine oxide and 2-hydroxy-2-methyl- 1-phenyl-propan-1-one) and 819 [bis(2,4,6-trimethylbenzoylphenylphosphine oxide)] and "DAROCUR" 1173 (2-hydroxy-2-methyl -1-phenyl-1-propane) and 4265 (2,4,6-trimethylbenzoyldiphenylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one combination); and visible light [blue] photoinitiators, d1-camphorquinone and "IRGACURE" 784DC. Of course, combinations of these substances can also be used here.

Other photoinitiators useful herein include alkyl pyruvates such as methyl, ethyl, propyl, and butyl pyruvate, and aryl pyruvate such as phenyl, benzyl, and suitable substituted derivatives thereof .

Photoinitiators particularly suitable for use herein include ultraviolet photoinitiators such as 2,2-dimethoxy-2-phenylacetophenone (e.g., "IRGACURE" 651), and 2-hydroxy-2-methyl -1-phenyl-1-propane (for example, "DAROCUR" 1173), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (for example, "IRGACURE" 819), and bis(2 , 6-dimethoxybenzoyl-2,4,4-trimethylpentyl)phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one UV/visible light combination of reagents (for example, "IRGACURE" 1700), and the visible light initiator bis(-5-2,4-cyclopentadien-1-yl)-bis[2,6-difluoro-3-(1H-pyrrole -1-yl)phenyl]titanium (for example, "IRGACURE" 784DC).

Additional photoinitiators can be selected from those available from Sartomer, Inc., Exton, Pennsylvania under the trade designations "ESACURE" and "SARCAT." Examples include "ESACURE" KB1 (benzil dimethyl ketal), "ESACURE" EB3 (a mixture of benzoin and butyl ether), "ESACURE" TZT (a blend of trimethylbenzophenone), "ESACURE" KIP100F (hydroxyketone), "ESACURE" KIP150 (polymer hydroxyketone), "ESACURE" KT37 (a blend of "ESACURE" TZT and KIP150), "ESACURE" KT046 (triphenylphosphine oxide, "ESACURE" "KIP150 and TZT blend), and "ESACURE" X33 (a blend of 2- and 4-isopropylthioxanthone, ethyl 4-(dimethylamino)benzoate and "ESACURE" TZT) .

Of course, those skilled in the art may use such combinations of photoinitiators as desired.

Alternatively, the photoinitiator may be a cationic photoinitiator capable of catalyzing the polymerization of the liquid components of the compositions of the present invention upon exposure to suitable radiation conditions. Desirable cationic photoinitiators for use in the present invention include triarylsulfonium and diaryliodonium salts containing non-nucleophilic counterions, and aryldiazonium salts, examples of which include 4-methoxybenzenehexa Diazonium fluorophosphate, diazonium benzenetetrafluoroborate, iodonium diphenyl chloride, iodonium diphenylhexafluorophosphate, 4,4-dioctyloxydiphenyliodonium hexafluorophosphate Onium salt, triphenylsulfonium tetrafluoroborate, diphenylcresylsulfonium hexafluorophosphate, phenylxylylsulfonium hexafluoroarsenate, and diphenylthiophenoxyphenylhexafluoroantimonate Sulfonium salts, and those commercially available from Sartomer, such as "SARCAT" CD1010 [triaryl hexafluorosulfonium antimonate (50% propylene carbonate)], "SARCAT" DC1011 [triaryl hexafluorosulfonium salt (50% % n-propylene carbonate)], "SARCAT" DC1012 [iodonium diaryl hexafluoroantimonate], and "SARCAT" K185 [sulfonium triaryl hexafluorophosphate (50% propylene carbonate)] .

The b-stage heat curable composition may further include a filler in the range of about 20-90 wt%, based on the total weight of the composition.

Fillers contemplated in the practice of the present invention may optionally be conductive (electrically and/or thermally conductive) fillers.

Conductive fillers contemplated in the practice of this invention include, for example, silver, nickel, gold, cobalt, copper, aluminum, graphite, silver-coated graphite, nickel-coated graphite, alloys of such metals, and the like, and mixtures thereof. Fillers in powder and flake form can be used here. In flake form, the filler may have a thickness of less than about 2 microns, with a planar dimension of about 20 to about 25 microns. The flakes used herein may have a surface area of about 0.15 to 5.0 ^m2 /g, and a bulk density of about 0.4 to about 5.5 g/cc. In powder form, the filler particles may be about 0.5-30 microns in diameter, such as about 20 microns.

Thermally conductive fillers contemplated in the practice of this invention include, for example, aluminum nitride, boron nitride, silicon carbide, diamond, graphite, beryllium oxide, magnesium oxide, silicon oxide, aluminum oxide, and the like.

The electrically and/or thermally conductive filler should be rendered substantially free of catalytically active metal ions by treatment with chelating agents, reducing agents, nonionic lubricants or mixtures of such agents. Such processing is disclosed in US Patent No. 5,447,988, the entirety of which is expressly incorporated herein by reference.

Optionally, fillers that are neither electrically nor thermally conductive can be used in addition to or as an alternative to conductive fillers. Such fillers can desirably impart some other physical property to the formulation, such as reduced thermal expansion of the cured composition, reduced dielectric constant, improved toughness, increased hydrophobicity, and the like. Examples of such fillers include perfluorinated hydrocarbon polymers (ie, TEFLON), thermoplastic polymers, thermoplastic elastomers, mica, fumed silica, glass powder, spacer elements, and the like.

The b-stage heat curable composition can be pre-applied to either (a ) on at least a portion of an opposing surface of a circuit chip or (b) on at least a portion of a bonding pad of a substrate.

The composition can be substantially free of non-reactive solvents or diluents, or, depending on the ingredients used, can include non-reactive solvents or diluents. When a diluent is added, it is required that the diluent is a reactive diluent which combines with the maleimide-containing compound to form a thermosetting resin composition. Such reactive diluents include acrylate and methacrylate esters of monofunctional and polyfunctional alcohols, vinyl compounds described in more detail herein, styrene monomers (i.e., derived from vinylbenzyl chloride with mono-, di-, or trifunctional hydroxyl compound reacted ethers) and the like.

Exemplary coupling agents contemplated in the practice of the present invention include silicates, metal acrylates such as aluminum methacrylate, titanates such as titanium triisopropoxide methacryloxyethylacetoacetate, ), or compounds containing copolymerizable groups and chelating ligands (eg, phosphines, thiols, acetoacetates, and the like). Generally, at least one coupling agent is used in the range of about 0.1-10 wt % (based on the total weight of the organic phase), with about 0.5-2 wt % being preferred.

Some desirable coupling agents contain copolymerizable functional groups (eg vinyl moieties, acrylate moieties, methacrylate moieties, styrene moieties, cyclopentadiene moieties, etc.) as well as silicate functional groups. The silicate moiety in the coupling agent is capable of condensing with metal hydroxides present on the mineral surface of the substrate, while the copolymerizable functional groups are capable of copolymerizing with other reactive components in the adhesive composition of the present invention. An example of such a coupling agent is an oligomeric silicate coupling agent such as poly(methoxyvinylsiloxane).

Other particularly desirable coupling agents include those represented by the following structures:

A _a -LZ _b

wherein each A is independently a radically polymerizable group, each L is independently a covalent bond or a polyvalent organic group; each Z is independently hydrogen bonded to a substrate having free hydroxyl groups on its surface and/or a reactive moiety of a covalent bond, a is 1-200, and b is 1-200.

Free radically polymerizable groups A include optionally substituted maleimides, optionally substituted vinyl ethers, optionally substituted vinyl sulfides, optionally substituted vinyl esters, optionally substituted rich Maleate, optionally substituted vinylthioester, optionally substituted diallylamide, optionally substituted styrene functional group, optionally substituted polybutadienyl, and the like. These functional groups can co-cure with bismaleimide or acrylate resin systems via a free radical mechanism when catalyzed by small amounts of free radical inhibitors. Alternatively, such functional groups can be co-polymerized with maleimide or acrylate resin systems if the system is exposed to elevated curing temperatures, UV radiation, or the like without the use of free radical initiators. solidified.

The b-stage heat curable composition of the present invention may further contain other additives such as defoamers, leveling agents, dyes and pigments.

Referring to the drawings, wherein like numbered features refer to like components throughout the several views, FIGS. 1 and 2 depict a circuit assembly 50 . In general, circuit assembly 50 includes a semiconductor chip with die attach adhesive pre-applied onto die backside 60 , and a carrier substrate such as circuit board substrate 70 .

Circuit chip 60 includes die 62 . Die 62 may be fabricated from any material known in the art. For example, die 62 may be fabricated from silicon, germanium, or the like. Die 62 may also be coated with a passivation material that inhibits environmental corrosion, such as a polyimide-, polybenzocyclobutane- or silicon nitride-based material.

Substrate 70 may also be fabricated from any material known in the art. For example, the substrate 70 may be made of a ceramic substrate (including Al ₂ O ₃ , silicon nitride (SiN ₃ ) and mullite (Al ₂ O ₃ —SiO ₂ )); a substrate of a heat-resistant resin such as polyimide or Ribbon; glass reinforced epoxy substrate; acrylonitrile-butadiene-styrene (ABS) substrate; Substrates made of metal materials such as Cu, Alloy42, etc. Substrate 70 includes circuitry on substrate surface 74 including a plurality of circuit bond pads 76 .

Die 62 includes opposing first and second surfaces, including chip surface 64 as the first surface and connection surface 68 as the second surface. Circuitry is provided on a chip surface 64, wherein the associated chip surface 64 includes a plurality of circuit contact pads, such as metallized bond pads 66, arranged in a predetermined pattern. These electrical contact pads may be connected to bonding pads 76 of substrate 70 . The connection between the circuitry on the die 62 and the circuitry on the substrate 70 is provided by bonding (eg, established by wiring 80) between each contact pad 66 on the die 62 and a contact pad 76 on the substrate 70. Electrical connection and engagement between them. Electrical connections may be established by bonding wires 80 to contact pads 76 after the die attach material has cured. Although for purposes of describing the present invention, the drawings of the present invention depict two wires 80 bonded to die 62 and two corresponding contact pads 76 on substrate 70, it is to be understood that the bonding of the wires and the contact pads 76 The number may vary depending on the particular desired application and the particular configuration of the circuit chip, and the specific configurations described herein should not be considered limiting of the invention.

In the present invention, die 62 includes metallized electrical contacts in the form of contact pads 66 on chip surface 64 and b Step die attach adhesive 90 . After exposure to suitable curing conditions, b-stage die attach material 90 provides circuit assembly 50 with high adhesive strength for bonding die 62 to substrate 70 . In general, by exposure to elevated temperature conditions sufficient to promote b-stage curing of b-stage die attach adhesive 90, by forming a fully cured material in solid form for chip die 62 to attach and bond to substrate 70 , so that this bonding occurs.

The present invention further provides circuit assembly 50 in assembled form, as shown in FIG. 2, wherein die 62 is bonded to substrate 70 and exposed to suitable conditions to cause b-stage die attach adhesive 90 to attach and adhere die 62. onto the substrate 70. Furthermore, die 62 may then be electrically connected to substrate 70 by establishing electrical connections between contact pads 66 and 76 , such as by soldering or otherwise bonding wires 80 therebetween.

In one embodiment, the present invention thus provides an article of manufacture in the form of a die having a first surface capable of providing electrical engagement with another die or a carrier substrate to be electrically connected, and a second surface opposite the first surface. surface, and having a b-stage die attach adhesive disposed on at least a portion thereof. Provides b-stage die attach adhesives directly on the die surface, eliminating the production issues of volume and temperature adjustments, and storage, handling, and shelf life issues that are also often associated with flowable or liquid die attach adhesives consider. That is, the end user no longer needs to use complex dispensing equipment and cryogenic storage containers for applying the material. In addition, end users can now use either semiconductor chips or semiconductor wafers with a b-stage die attach adhesive pre-applied to at least a portion of their surfaces and assemble in accordance with the present invention with greater ease and increased yield Semiconductor device.

Preapplied semiconductor chips with b-stage die attach adhesives also enable end users to implement more hermetic package design requirements. That is, a tighter seal between the die edge and the bond point is achieved due to reduced run-off and bleed from such a b-stage die attach adhesive compared to many known die attach adhesives Tolerance. In addition, it is now possible to stack semiconductor chips so that the overall size of the semiconductor device can be reduced, or at least remain substantially the same in length and width, while significantly increasing the performance of the stacked semiconductor chips. See, eg, US Patent Nos. 5,323,060, 5,286,679, 5,140,404, and 6,465,893, the disclosures of each of which are hereby incorporated by reference.

Furthermore, many conventional die attach adhesives benefit from tighter process control to avoid kerf creep and contact bond pad contamination during bonding of thin dies, but when using the b-stage die attach adhesive of the present invention In combination, this protection is not required. Again, it offers package designers much greater design flexibility and capabilities.

The b-stage die attach adhesive of the present invention can be applied by stencil printing, screen printing, or spraying.

In the case of stencil printing or screen printing onto pre-cut wafers, the wafers can be uniformly coated with the die attach adhesive of the present invention prior to curing. During wafer dicing, the diced sawdust then completely cuts through the cured die connecting the adhesive layer and the wafer.

In the case of stencil printing or screen printing onto diced wafers, the fabrication stencil or screen has apertures designed to partially coat individual die or semiconductor chips. Specifically, the die attach adhesive of the present invention is maintained in place using a grid of stencils or screens. That is, it is undesirable for die attach adhesive to get into the streets of dicing, which will facilitate die separation during die placement. The width of the mesh, or conversely, the size of the apertures is designed so that after the die is placed, the targeted wet bond line can be achieved, and the die attach adhesive can form a fillet of the desired height under the die.

In the case of stencil printing or screen printing onto a laminated substrate, the manufacture of the stencil or screen has apertures designed to partially coat the die pads, and in particular, the use of the stencil or screen after die placement Mesh, holding small pieces of bonding adhesive in place. Design the width of the mesh, or conversely, the size of the apertures, so that after the die is placed, the targeted wet bond line can be achieved, and the die attach adhesive can form the desired height of the rule under the die with minimal to no Wetting of the die attach adhesive to be electrically connected.

When applied to a laminated substrate, a "zero gap bond line" can be achieved with the die attach adhesives of the present invention. For example, the laminate can be fabricated first without a solder mask layer on the die pad. Thus, the height of the die pad area is relatively lower than that of the non-bonded die pad area, and its depth is equal to the thickness of the solder mask layer, typically about 1 mil. These recessed die pads are then filled with die attach adhesive using stencil printing, screen printing or spray coating.

Preferably, an appropriate amount of the b-stage die attach adhesive of the present invention is applied until the surface to which the adhesive is applied is flush with the solder mask layer. The recessed die pad is not completely filled with die attach adhesive; rather, an appropriate amount of die attach adhesive is applied so that in the die arrangement, the die attach adhesive flows under the die to cover the bottom of the previously exposed die pad. This approach allows semiconductor package manufacturers to achieve thinner packages without changing the bondline adhesive.

Alternatively, the b-stage die attach adhesive of the present invention can be used as a solder mask replacement, either inside or outside the die pad area, or both.

In the case of spray coating, thin semiconductor wafers are ideal substrates on which to apply die attach adhesives. These thin semiconductor wafers have a typical thickness of about 2-3 mils. Although mechanically robust once properly supported, ie bonded to a flexible substrate and encapsulated or overmolded, the resulting thin chips in unsupported form from these wafers are brittle and break rather easily. Thus, advantageously, the method of applying the die attach adhesive to the thin wafer uses minimal force while doing so.

After applying the b-stage die attach adhesive of the present invention to a wafer or die using any of the methods described above, the adhesive is then dried to remove solvent, if present, or cooled to consolidate the adhesive ( if applied under mildly elevated temperature conditions).

Typical drying times may be about 30 minutes at a temperature of about 100°C, but any temperature below the onset of cure of the curable components in the b-stage die attach adhesive may be chosen. The length of time can vary depending on the time required for the surface of the die attach adhesive to become tack-free at the selected temperature.

Bonding of the die can occur any time after the die attach adhesive surface is tack-free (either passed or dried or cooled).

Conditions suitable for curing the b-stage die attach adhesive include subjecting the adhesive of the present invention to a temperature of at least about 175°C but less than about 300°C for about 0.5 to about 2 minutes. A typical die bonding set point is in the case of a 7.6 mm x 7.6 mm die, using an application weight of 500 cN at a temperature of about 100°C for a time of about 10 seconds. This fast, fast curing can be achieved in various ways, e.g. using in-line fast curing stations such as those manufactured by Nihon Sanso, heating segments mounted on the die bonder, or IR beams provided by EFOS Novacure IR units. Short duration heating.

In the case of stacked die assemblies (see FIG. 4, described below; see U.S. Patent Nos. 5,323,060, 5,286,679, 5,140,404, and 6,465,893, the disclosures of each of which are expressly incorporated herein by reference), it may be advantageous to , to heat the die by pulsating heat through a die collet (which is a feature found in die bonders for membranes), such as those made by ESC. In the case of thin chips, which typically warp due to the build-up of residual mechanical stress during the grinding process, heating the chip above a certain temperature often anneals the chip and thereby reduces warping.

It is to be noted that the die 62 described here may be provided as a single die, or may be provided as a chip scale package, as depicted as 160 in FIG. 3 . Thus, in FIG. 3 , a circuit assembly 150 comprising a chip scale package 160 is provided. Chip scale packages are known in the art for electrical connection of circuits to circuit board substrates. In an embodiment of the present invention, circuit assembly 150 includes a structure similar to that of the embodiment shown in FIG. 2 , except chip scale package 160 is used in place of die 62 . For example, circuit assembly 150 includes a circuit board substrate 70 that includes contact pads 76 thereon. Substrate 70 is attached to chip scale package 160, which may include, for example, a die attached to a separate carrier substrate or interposer layer, as is known in the art. In this embodiment, contact pads 66 and/or wiring 80 may be provided on this separate carrier substrate or on an intervening layer in a manner similar to that outlined above with respect to circuit chip 60 . Additionally, chip scale package 160 is attached to substrate 70 via die attach material 90 in a manner similar to that described above.

In connection with stacked die applications, FIG. 4 depicts a schematic cross-sectional view of two die stacked within a stacked die assembly 350 comprising a semiconductor chip in the form of a pre-applied die-connected circuit chip 360 (which has a die 62 and The b-stage die attach adhesive 90 of the present invention placed thereon, and the pre-applied die attach circuit chip 360 to the other die 62A to which it will be attached.

Circuit chip 360 includes chip die 62 (as described above with reference to FIG. 1 ). Similar to die 62, another die 62A may be fabricated from any material known in the art, and may be fabricated from the same or a different material.

The other die 62A includes opposing first and second surfaces, including a chip surface 64A as the first surface, which is the connection surface of the die 62 . Electrical contact pads arranged in a predetermined pattern, such as metallized contact pads 66A, may be connected to contact pads of the substrate or to another die (neither shown). By virtue of the bond (as established by wires 80) between each contact pad 66 on die 62 and a contact pad 66A on the other die 62A, circuitry on die 62 and on the other die 62A are provided. Electrical connections and engagement between circuits on a die 62A. Electrical connection may be established by bonding wiring 80 to contact pad 66A before, or preferably after, curing of the b-stage die attach adhesive. Alternatively, the electrical connection may be established by bonding wiring 80 to contact pads directly on substrate 70 . Although for purposes of illustrating the present invention, the drawings of the present invention depict two wires 80 bonded to a die 62 and two corresponding contact pads 66A on another die 62A, it is to be understood that the wires are bonded to each other. The number of junctions and contact pads 66A may vary depending on the particular desired application and the particular configuration of the circuit chip, and the specific configurations described herein should not be construed as limiting the invention (see US Patent No. 5,323,060).

The present invention will become more readily understood with reference to the following examples.

Example

Example 1:

A b-stage die attach adhesive was prepared using the components listed below in the amounts stated. Maleimides were prepared according to the procedure outlined in US Patent No. 5,973,166, the disclosure of which is incorporated herein by reference.

Lauryl bismaleimide 69.3g

X-BMI ¹ 10.8g

RICON 130 ² 2.9g

2-Phenoxyacrylate 15.8g

Coupling agent ³ 1.0

Peroxide ⁴ 0.2g

¹ X-BMI (1,20-bismaleimide derivative of 10,11-dioctyleicosane), prepared according to the procedure outlined in U.S. Patent No. 5,973,166, the disclosure of which is hereby incorporated by reference introduce.

² 20% polybutadiene grafted with maleic anhydride (commercially available from Sartomer).

³ (β-3,4-epoxycyclohexyl)ethyltrimethoxysilane

⁴ bis(4-tert-butylcyclohexyl) peroxydicarbonate

After each component was added at room temperature, the b-stage die attach adhesive was thoroughly mixed, dispensed on a glass slide, and heated to a temperature of 90°C for 10 minutes, followed by 125°C for 1 minute.

Heat the b-stage die attach adhesive to a temperature of 125°C - 130°C for less than 60 seconds, and place the silicon die on it. The silicon wafer was then attached to a glass slide by heating at a temperature of 150°C for a period of 1 hour.

The b-stage die attach adhesive was then evaluated for room temperature die shear and hot die shear on a calibrated Dage 4000 die shear tester. A small plate shear greater than 100 kg-f was observed at room temperature and a thermal plate shear of 45 +/-19 was observed.

Example 2:

A b-stage die attach adhesive was prepared using the components listed below in the amounts stated. Maleimides were prepared according to the procedure outlined in US Patent No. 5,973,166, as described above.

Lauryl bismaleimide 68.6g

X-BMI 10.7g

RICON 130 23.0g

2-Phenoxyacrylate 15.6g

Coupling agent 0.8

Peroxide ⁵ 12g

⁵ cumyl hydroperoxide

After each component was added at room temperature, the b-stage die attach adhesive was thoroughly mixed, dispensed on a glass slide, and heated to a temperature of 90°C for 10 minutes, followed by 125°C for 1 minute.

Heat the b-stage die attach adhesive to a temperature of 125°C - 130°C for less than 60 seconds, and place the silicon die on it. The silicon wafer was then attached to a glass slide by heating at a temperature of 150°C for a period of 1 hour.

The b-stage die attach adhesive was then evaluated for room temperature die shear and hot die shear on a calibrated Dage 4000 die shear tester. A small plate shear greater than 100 kg-f was observed at room temperature and a thermal plate shear of 63 +/- 23 was observed.

Example 3:

A silver-filled b-stage die attach adhesive was prepared using the components listed below in the amounts stated. As in Example 1, maleimides were prepared according to the procedure outlined in US Patent No. 5,973,166.

Lauryl bismaleimide 9.4g

X-BMI 3.35g

BMI Citraconamide 5.7g

RICON 130 2.9g

2-Phenoxyacrylate 4.9g

Coupling agent 0.25

Peroxide ⁶ 0.1g

Silver filler ⁷ 75.5g

⁶ Bis(4-tert-butylcyclohexyl)peroxydicarbonate

⁷ Particle size between 1 and 50 microns

After each component was added at room temperature, the b-stage die attach adhesive was thoroughly mixed, dispensed on a glass slide, and heated to a temperature of 90°C for 10 minutes, followed by 125°C for 1 minute.

Heat the b-stage die attach adhesive to a temperature of 125°C - 130°C for less than 60 seconds, and place the silicon die on it. The silicon wafer was then attached to a glass slide by heating at a temperature of 150°C for a period of 1 hour.

The b-stage die attach adhesive was then evaluated for room temperature die shear and hot die shear on a calibrated Dage 4000 die shear tester. A small plate shear greater than 100 kg-f was observed at room temperature and a thermal plate shear of 51 +/-13 was observed.

Example 4:

Another silver-filled b-stage die attach adhesive was prepared using the components listed below in the amounts stated. Again as in Example 1, the maleimide was prepared according to the procedure outlined in US Patent No. 5,973,166.

Lauryl bismaleimide 7.6g

X-BMI 2g

RICON 130 1.3g

Dicyclopentadienyl MA 4.5g

Bisphenol A di(meth)acrylate 2.3g

Coupling agent 1.3g

Peroxide 1g

Silver filler 80g

After each component was added at room temperature, the b-stage die attach adhesive was thoroughly mixed and the viscosity measured at 1 rpm to be 349,000 cps. The b-stage die attach adhesive was dispensed onto a glass slide and heated to a temperature of 125 for 5 minutes.

Heat the b-stage die attach adhesive to 175 for 1 hour. At this point, the cured die attach adhesive was allowed to cool to room temperature and its volume resistance was measured to be 0.00023 Ω-cm.

The b-stage die attach adhesive was screen printed onto a ceramic substrate and heated to a temperature of 125°C for 5 minutes. Allow the b-stage die attach adhesive to cool to room temperature. The b-stage die attach adhesive is heated to a temperature of 125 to melt the solid components so that the silicon die can be placed thereon. The assembly was bonded together by heating at a temperature of 175°C for a period of 1 hour.

The b-stage die attach adhesive was then evaluated for hot die shear at 275 on a calibrated Dage 4000 die shear tester. A thermal platelet shear of 46 +/- about 10 was observed.

Claims (42)

1. A b-stage curable composition comprising: a. a solid component thermally curable at a first temperature; b. a liquid component that is curable either thermally at a second temperature or when exposed to radiation within the electromagnetic spectrum; and c. a thermal curing catalyst for the solid curable component, Wherein the thermal curing catalyst is selected from free radical catalysts, anionic curing agents, cationic curing agents and combinations thereof, wherein the free radical catalysts are members selected from peroxides, azo compounds and combinations thereof. 2. The composition of claim 1, wherein the anionic curing agent is a member selected from the group consisting of aza compounds, amine compounds, imidazole compounds, and combinations thereof. 3. The composition of claim 1, wherein the anionic curing agent is a member selected from the group consisting of aza compounds, amine compounds, imidazole compounds, and combinations thereof, wherein the aza compound is a member selected from the group consisting of: 1,5-Diazabicyclo[4.3.0]non-5-ene

1,8-Diazabicyclo[5.4.0]undec-5-ene(DBU) 1,5,7-Triazabicyclo[4.4.0]dec-5-ene

quinucline

1,4-Diazabicyclo[2.2.2]octane. 4. The composition of claim 3, wherein the amine compound is a member selected from the group consisting of aliphatic polyamines, aromatic polyamines, cycloaliphatic polyamines, and combinations thereof. 5. The composition of claim 3, wherein the amine compound is selected from the group consisting of diethylenetriamine, triethylenetetramine, diethylaminopropylamine, benzyldimethylamine, m-xylylenediamine, diaminodiphenylamine , quinoxaline, isophoronediamine, oxenediamine, and members of combinations thereof. 6. The composition of claim 3, wherein the imidazole compound is selected from the group consisting of isoimidazole, imidazole, 2-ethyl-4-methylimidazole, 2,4-dimethylimidazole, butylimidazole, 2-heptadecene Base-4-methylimidazole, 2-methylimidazole, 2-undecenylimidazole, 1-vinyl-2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-propyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl -4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-guanidinoethyl-2-methylimidazole, imidazole and The addition product of imidazole, the addition product of imidazole and trimellitic acid, 2-heptadecyl-4-methylimidazole, phenylimidazole, benzylimidazole, 2-methyl-4,5-di Phenylimidazole, 2,3,5-triphenylimidazole, 2-styryl imidazole, 1-(dodecylbenzyl)-2-methylimidazole, 2-(2-hydroxy-4-tert-butyl phenyl)-4,5-diphenylimidazole, 2-(2-methoxyphenyl)-4,5-diphenylimidazole, 2-(3-hydroxyphenyl)-4,5-di Phenylimidazole, 2-(p-dimethylaminophenyl)-4,5-diphenylimidazole, 2-(2-hydroxyphenyl)-4,5-diphenylimidazole, bis(4,5- Diphenyl-2-imidazole)-benzene-1,4,2-naphthyl-4,5-diphenylimidazole, 1-benzyl-2-methylimidazole, 2-p-methoxystyryl imidazole and its combined members. 7. A b-stage curable composition comprising: a. a solid component thermally curable at a first temperature; b. a liquid component that is curable either thermally at a second temperature or when exposed to radiation within the electromagnetic spectrum; and c. a thermal curing catalyst for the solid curable component, wherein the thermal curing catalyst is selected from free radical catalysts, anionic curing agents, cationic curing agents and combinations thereof, wherein the cationic curing agent is a member selected from organic acids, acid anhydrides, Lewis acids and combinations thereof. 8. The composition of claim 7, wherein the organic acid is a member selected from the group consisting of phenols, thiophenols, thiols, carboxylic acids, and combinations thereof. 9. A b-stage curable composition comprising: a. a solid component thermally curable at a first temperature; b. a liquid component that is curable either thermally at a second temperature or when exposed to radiation within the electromagnetic spectrum; and c. a thermal curing catalyst for the solid curable component, A second thermal curing catalyst for the liquid curable component is further included. 10. The composition of claim 9, wherein curing the liquid curable component by the second thermal curing catalyst is carried out at a temperature in the range of about 50° C. to about 150° C., and curing the solid curable component by the first thermal curing catalyst The composition is carried out at a temperature in the range of about 100°C to about 300°C. 11. The composition of claim 9, wherein the liquid curable component is cured at a temperature of less than about 100° C. by the second thermal curing catalyst, and the solid curable component is cured by the first thermal curing catalyst at a temperature above at a temperature of about 100°C. 12. A b-stage curable composition comprising: a. a solid component thermally curable at a first temperature; b. a liquid component that is curable either thermally at a second temperature or when exposed to radiation within the electromagnetic spectrum; and c. a thermal curing catalyst for the solid curable component, Among them, the liquid curable components include epoxy, episulfide, maleimide, endomethylenetetrahydrophthalimide, itaconimide, (meth)acrylate, vinyl ether , vinyl esters, styrene and its derivatives, poly(alkenylene), allylamide, norbornenyl, thiolene and combinations thereof. 13. The composition of claim 12, wherein the melting point range of the solid curable component is less than the temperature at which the solid curable component solidifies. 14. The composition of claim 12, wherein the melting point range of the solid curable component is substantially the same as the temperature at which the solid curable component solidifies. 15. The composition of claim 12, further comprising a reactive diluent. 16. The composition of claim 12, wherein the composition is substantially free of non-reactive solvents. 17. The composition of claim 12, further comprising a solvent. 18. The composition of claim 12, further comprising a filler. 19. The composition of claim 18, wherein the filler is a conductive filler. 20. The composition of claim 18, wherein the filler is thermally conductive. 21. The composition of claim 18, wherein the filler is electrically conductive. 22. The composition of claim 18, wherein the filler is a non-conductive filler. 23. The composition of claim 18, wherein the filler has a particle size of less than about 50 microns. 24. The composition of claim 12, further comprising a photoinitiator. 25. The composition of claim 24, wherein the photoinitiator is selected from radiation-initiated catalysts in the UV, UV/VIS, VIS, IR, e-beam, X-ray, and microwave ranges of the electromagnetic spectrum. 26. A b-stage curable composition comprising: a. a solid component thermally curable at a first temperature; b. a liquid component that is curable either thermally at a second temperature or when exposed to radiation within the electromagnetic spectrum; and c. a thermal curing catalyst for the solid curable component, Among them, the solid curable components include epoxy, episulfide, maleimide, endomethylenetetrahydrophthalimide, itaconimide, (meth)acrylate, vinyl ether , vinyl ester, styrene and derivatives thereof, poly(alkenylene), allylamide, norbornenyl, thiolene and combinations thereof. 27. A b-stage curable composition comprising: a. a solid component thermally curable at a first temperature; b. a liquid component that is curable either thermally at a second temperature or when exposed to radiation within the electromagnetic spectrum; and c. a thermal curing catalyst for the solid curable component, Wherein the liquid curable component is a maleimide-containing compound, an itaconimide-containing compound or an endomethylenetetrahydrophthalimide-containing compound including the following:

in: m=1-15, p=0-15, each R ^is independently selected from hydrogen or lower alkyl, and J is a monovalent or multivalent moiety containing an organic or organosiloxane group, and combinations of two or more thereof. 28. A b-stage curable composition comprising: a. a solid component thermally curable at a first temperature; b. a liquid component that is curable either thermally at a second temperature or when exposed to radiation within the electromagnetic spectrum; and c. a thermal curing catalyst for the solid curable component, wherein the liquid curable component is a maleimide-containing compound, an itaconimide-containing compound, or an endomethylenetetrahydrophthalimide-containing compound including structures I, II, and III, in m=1-6, p=0, R ^is independently selected from hydrogen or lower alkyl, and J is a monovalent or multivalent group selected from hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, substituted heteroatom-containing hydrocarbyl, hydrocarbylene, substituted hydrocarbylene, heteroatom-containing hydrocarbylene, substituted heteroatom-containing Alkylene groups, polysiloxanes, polysiloxane-polyurethane block copolymers, and combinations of two or more thereof, the monovalent or multivalent groups optionally contain one or more linking groups, The linking group is selected from covalent bond, -O-, -S-, -NR-, -OC(O)-, -OC(O)-O-, -OC(O)-NR-, -NR- C(O)-, -NR-C(O)-O-, -NR-C(O)-NR-, -SC(O)-, -SC(O)-O-, -SC(O)- NR-, -S(O)-, -S(O) ₂ -, -OS(O) ₂ -, -OS(O) ₂ -O-, -OS(O) ₂ -NR-, -OS(O )-, -OS(O)-O-, -OS(O)-NR-, -O-NR-C(O)-, -O-NR-C(O)-O-, -O-NR- C(O)-NR-, -NR-OC(O)-, -NR-OC(O)-O-, -NR-OC(O)-NR-, -O-NR-C(S)-, -O-NR-C(S)-O-, -O-NR-C(S)-NR-, -NR-OC(S)-, -NR-OC(S)-O-, -NR-OC (S)-NR-, -OC(S)-, -OC(S)-O-, -OC(S)-NR-, -NR-C(S)-, -NR-C(S)-O -, -NR-C(S)-NR-, -SS(O) ₂ -, -SS(O) ₂ -O-, -SS(O) ₂ -NR-, -NR-OS(O)-, -NR-OS(O)-O-, -NR-OS(O)-NR-, -NR-OS(O) ₂ -, -NR-OS(O) ₂ -O-, -NR-OS(O ) ₂ -NR-, -O-NR-S(O)-, -O-NR-S(O)-O-, -O-NR-S(O)-NR-, -O-NR-S( O) ₂ -O-, -O-NR-S(O) ₂ -NR-, -O-NR-S(O) ₂ -, -OP(O)R ₂ -, -SP(O)R ₂ - , -NR-P(O)R ₂ -, wherein each R is independently hydrogen, alkyl or substituted alkyl, and combinations of two or more thereof. 29. A b-stage curable composition comprising: a. a solid component thermally curable at a first temperature; b. a liquid component that is curable either thermally at a second temperature or when exposed to radiation within the electromagnetic spectrum; and c. a thermal curing catalyst for the solid curable component, Wherein the solid curable component is a maleimide-containing compound, an itaconimide-containing compound or an endomethylenetetrahydrophthalimide-containing compound which is solid at room temperature. 30. The composition of claim 29, wherein the maleimide-containing compound, itaconimide-containing compound or endomethylenetetrahydrophthalimide-containing compound is a solid and comprises: in: m=1-15, p=0-15, each R ^is independently selected from hydrogen or lower alkyl, and J is a monovalent or multivalent moiety containing an organic or organosiloxane group, and combinations of two or more thereof. 31. A b-stage curable composition comprising: a. a solid component thermally curable at a first temperature; b. a liquid component that is curable either thermally at a second temperature or when exposed to radiation within the electromagnetic spectrum; and c. a thermal curing catalyst for the solid curable component, Wherein the liquid component comprises one or more of a maleimide-containing compound, an itaconimide-containing compound or an endomethylenetetrahydrophthalimide-containing compound, said compounds Including maleimide functional groups, itaconimide functional groups or endomethylenetetrahydrophthalimide functional groups attached to monovalent groups, respectively, or maleimide functional groups separated by polyvalent groups Amine functional groups, itaconimide functional groups or endomethylenetetrahydrophthalimide functional groups, each monovalent group or multivalent group has sufficient length and degree of branching to make the maleimide-containing The compound containing itaconimide or the compound containing endomethylenetetrahydrophthalimide is a liquid respectively. 32. A method of preparing the composition of claim 12, the steps comprising: a. providing a solid curable component that is thermally curable at a first temperature, a liquid component that is thermally curable at a second temperature or that is curable when exposed to radiation within the electromagnetic spectrum, and for the solid a thermal curing catalyst for the curable component; and b. Mixing the solid curable component, liquid curable component and thermal curing catalyst together. 33. The method of claim 32, further comprising: c. exposing the composition to conditions favorable to curing of the liquid curable component. 34. The method of claim 33, further comprising: d. exposing the composition to temperature conditions sufficient to melt the solid curable component. 35. The method of claim 34, further comprising: e. exposing the composition to temperature conditions sufficient to cure the molten solid curable component. 36. A method of adhesively bonding a first substrate to a second substrate, the method comprising: a. applying the composition of claim 12 to one or both of said first substrate or said second substrate; b. exposing the composition-applied substrate to conditions that advantageously cure the liquid curable component therein to form a b-staged curable film; c. exposing the b-staged curable film of b. to temperature conditions sufficient to melt the solid curable components therein; d. connecting said first substrate and said second substrate to form an assembly wherein the first substrate and said second substrate are separated by the composition applied in a.; and e. exposing the curable film of c. to temperature conditions sufficient to cure the molten solid curable component. 37. The method of claim 36, wherein said first substrate is a chip die. 38. The method of claim 36, wherein said first substrate and said second substrate are chip dies. 39. The method of claim 36, wherein said first substrate is a circuit board. 40. The method of claim 36, wherein said first substrate is a circuit board without a solder mask. 41. The method of claim 36, wherein said first substrate is a circuit board with a solder mask. 42. An article of manufacture comprising a semiconductor chip provided for attachment and electrical connection with another semiconductor chip or carrier substrate, the semiconductor chip having first and second surfaces, wherein the first surface has Electrical contacts arranged in a predetermined pattern to provide electrical engagement with another semiconductor chip or carrier substrate, respectively, and the second surface has the b-stage heat curable composition of claim 12 disposed on a layer or a portion thereof .

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