Formulations containing mixed resin systems and the use thereof for wafer-level underfill for 3D TSV packages

1. A composition comprising:

an epoxy resin;

a maleimide, nadimide or itaconimide;

an acrylate; and

a filler;

wherein:

said epoxy resin is a thermosetting resin which can cure into a three-dimensional polymer network;

said maleimide, nadimide or itaconimide is monomeric or oligomeric and can undergo radical cure to form a polymeric network;

said acrylate is monomeric or oligomeric and can undergo radical cure to form a polymeric network; and

said filler modulates the coefficient of thermal expansion (CTE) of the resulting composition;

wherein:

said composition, when cured, has a:

DSC onset of 100° C. 205° C.;

Melt viscosity in the range of 200 Poise-40,000 Poise, and

gelling temperature of 130° C. 180° C., as measured by Ares Rheometer at 10 Rad frequency with a 10° C./min ramp rate using a sample 1 inch in diameter and 1 mm thick.

2. The composition of claim 1 wherein said epoxy resin comprises a polymeric backbone having one or more epoxide groups thereon.

3. The composition of claim 2 wherein said epoxy resin is selected from bisphenol A epoxy resins, bisphenol F epoxy resins, naphthalene epoxy resins, novolac epoxy resins, siloxane-modified epoxy resins, cycloaliphatic epoxy resins, biphenyl epoxy resins, DCPD epoxy resins, or modified epoxy resins, as well as combinations of any two or more thereof.

4. The composition of claim 3 wherein said siloxane modified epoxy resin has the structure:

—(O—Si(Me) 2 -O—Si(Me)(Z)—O—Si(Me) 2 -O—Si(Me) 2 ) n —

wherein:

Z is —O—(CH 2 ) 3 —O-Ph-CH 2 -Ph-O—(CH 2 —CH(OH)—CH 2 —O-Ph-CH 2 -Ph-O—) n —CH 2 -oxiran e, and

n falls in the range of about 1-4.

5. The composition of claim 4 wherein said siloxane modified epoxy resin is produced by contacting a combination of the following components under conditions suitable to promote the reaction thereof

Me 2 Si(OMe) 2

+

(MeO) 3 Si—(CH 2 ) 3 —O—CH 2 -oxirane

+

oxirane-CH 2 —O-Ph-CH 2 -Ph-O—(CH 2 —CH(OH)—CH 2 —O-Ph-CH 2 -Ph-O—) n —CH 2 -oxirane,

wherein “n” falls in the range of about 1-4.

6. The composition of claim 1 wherein said maleimide, nadimide or itaconimide, has the structure:

respectively, wherein:

m is 1-15,

p is 0-15,

each R 2 is independently selected from hydrogen or lower alkyl (such as C 1-5 ), and

J is a monovalent or a polyvalent radical comprising organic or organosiloxane radicals, and

combinations of two or more thereof.

7. The composition of claim 6 wherein J is a monovalent or polyvalent radical selected from:

hydrocarbyl or substituted hydrocarbyl species typically having in the range of about 6 up to about 500 carbon atoms, where the hydrocarbyl species is selected from alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, alkylaryl, arylalkyl, aryalkenyl, alkenylaryl, arylalkynyl or alkynylaryl, provided, however, that X can be aryl only when X comprises a combination of two or more different species;

hydrocarbylene or substituted hydrocarbylene species typically having in the range of about 6 up to about 500 carbon atoms, where the hydrocarbylene species are selected from alkylene, alkenylene, alkynylene, cycloalkylene, cycloalkenylene, arylene, alkylarylene, arylalkylene, arylalkenylene, alkenylarylene, arylalkynylene or alkynylarylene,

heterocyclic or substituted heterocyclic species typically having in the range of about 6 up to about 500 carbon atoms,

polysiloxane, or

polysiloxane-polyurethane block copolymers, as well as

combinations of one or more of the above with a linker selected from covalent bond, —O—, —S—, —NR—, —NR—C(O)—, —NR—C(O)—O—, —NR—C(O)—NR—, —S—C(O)—, —S—C(O)—O—, —S—C(O)—NR—, —O—S(O) 2 —, —O—S(O) 2 —O—, —O—S(O) 2 —NR—, —O—S(O)—, —O—S(O)—O—, —O—S(O)—NR—, —O—NR—C(O)—, —O—NR—C(O)—O—, —O—NR—C(O)—NR—, —NR—O—C(O)—, —NR—O—C(O)—O—, —NR—O—C(O)—NR—, —O—NR—C(S)—, —O—NR—C(S)—O—, —O—NR—C(S)—NR—, —NR—O—C(S)—, —NR—O—C(S)—O—, —NR—O—C(S)—NR—, —O—C(S)—, —O—C(S)—O—, —O—C(S)—NR—, —NR—C(S)—, —NR—C(S)—O—, —NR—C(S)—NR—, —S—S(O) 2 —, —S—S(O) 2 —O—, —S—S(O) 2 —NR—, —NR—O—S(O)—, —NR—O—S(O)—O—, —NR—O—S(O)—NR—, —NR—O—S(O) 2 —, —NR—O—S(O) 2 —O—, —NR—O—S(O) 2 —NR—, —O—NR—S(O)—, —O—NR—S(O)—O—, —O—NR—S(O)—NR—, S(O) 2 —O—, —O—NR—S(O) 2 —NR—, —O—NR—S(O) 2 —, —O—P(O)R 2 —, —S—P(O)R 2 —, or —NR—P(O)R 2 —;

where each R is independently hydrogen, alkyl or substituted alkyl.

8. The composition of claim 6 wherein J is oxyalkyl, thioalkyl, aminoalkyl, carboxylalkyl, oxyalkenyl, thioalkenyl, aminoalkenyl, carboxyalkenyl, oxyalkynyl, thioalkynyl, aminoalkynyl, carboxyalkynyl, oxycycloalkyl, thiocycloalkyl, aminocycloalkyl, carboxycycloalkyl, oxycloalkenyl, thiocycloalkenyl, aminocycloalkenyl, carboxycycloalkenyl, heterocyclic, oxyheterocyclic, thioheterocyclic, aminoheterocyclic, carboxyheterocyclic, oxyaryl, thioaryl, aminoaryl, carboxyaryl, heteroaryl, oxyheteroaryl, thioheteroaryl, aminoheteroaryl, carboxyheteroaryl, oxyalkylaryl, thioalkylaryl, aminoalkylaryl, carboxyalkylaryl, oxyarylalkyl, thioarylalkyl, aminoarylalkyl, carboxyarylalkyl, oxyarylalkenyl, thioarylalkenyl, aminoarylalkenyl, carboxyarylalkenyl, oxyalkenylaryl, thioalkenylaryl, aminoalkenylaryl, carboxyalkenylaryl, oxyarylalkynyl, thioarylalkynyl, aminoarylalkynyl, carboxyarylalkynyl, oxyalkynylaryl, thioalkynylaryl, aminoalkynylaryl or carboxyalkynylaryl, oxyalkylene, thioalkylene, aminoalkylene, carboxyalkylene, oxyalkenylene, thioalkenylene, aminoalkenylene, carboxyalkenylene, oxyalkynylene, thioalkynylene, aminoalkynylene, carboxyalkynylene, oxycycloalkylene, thiocycloalkylene, aminocycloalkylene, carboxycycloalkylene, oxycycloalkenylene, thiocycloalkenylene, aminocycloalkenylene, carboxycycloalkenylene, oxyarylene, thioarylene, aminoarylene, carboxyarylene, oxyalkylarylene, thioalkylarylene, aminoalkylarylene, carboxyalkylarylene, oxyarylalkylene, thioarylalkylene, aminoarylalkylene, carboxyarylalkylene, oxyarylalkenylene, thioarylalkenylene, aminoarylalkenylene, carboxyarylalkenylene, oxyalkenylarylene, thioalkenylarylene, aminoalkenylarylene, carboxyalkenylarylene, oxyarylalkynylene, thioarylalkynylene, aminoarylalkynylene, carboxy arylalkynylene, oxyalkynylarylene, thioalkynylarylene, aminoalkynylarylene, carboxyalkynylarylene, heteroarylene, oxyheteroarylene, thioheteroarylene, aminoheteroarylene, carboxyheteroarylene, heteroatom-containing di- or polyvalent cyclic moiety, oxyheteroatom-containing di- or polyvalent cyclic moiety, thioheteroatom-containing di- or polyvalent cyclic moiety, aminoheteroatom-containing di- or polyvalent cyclic moiety, or a carboxyheteroatom-containing di- or polyvalent cyclic moiety.

9. The composition of claim 1 further comprising an organic diluent.

10. The composition of claim 1 wherein said composition comprises:

at least 1 wt % of said epoxy resin,

at least 6 wt % of said maleimide, nadimide or itaconimide,

at least 4 wt % of said acrylate, and

at least 30 wt % of said filler.

11. The composition of claim 10 , further comprising one or more of:

at least 1 wt % of a fluxing agent,

at least 0.1 wt % of an adhesion promoter; and/or

at least 4 wt % of a toughening agent.

12. The composition of claim 1 wherein said composition comprises:

in the range of about 1 up to 20 wt % of said epoxy resin,

in the range of about 6 up to 16 wt % of said maleimide, nadimide or itaconimide,

in the range of about 4 up to 12 wt % of said acrylate, and

in the range of about 30 up to 75 wt % of said filler.

13. The composition of claim 12 , further comprising one or more of:

at least 1 wt % of a fluxing agent,

at least 0.1 wt % of an adhesion promoter; and/or

at least 4 wt % of a toughening agent.

14. An underfill film comprising the reaction product of curing the composition of claim 1 .

15. The underfill film of claim 14 wherein said film absorbs less than 2% by weight moisture when exposed to 85° C. at 85% relative humidity for about 2 days.

16. The underfill film of claim 14 wherein the film is a B-staged film, which, after cure, has a Tg, as determined by thermomechanical analysis (TMA), of greater than about 80° C.

17. The underfill film of claim 14 wherein the die shear of said film at 260° C. is at least 5 kg/cm 2 as tested with SiN die/PI die/SiO 2 (size: 3.81×3.81×700 mm 3 ), wherein the die is attached on a BT substrate at 120° C./1 kg force/5 seconds, then cured by ramping the temperature from room temperature to 175° C. over 30 minutes, then held at 175° C. for 5 hrs.

18. A method for preparing an underfill film, said method comprising curing the composition of claim 1 after application thereof to a suitable substrate.

19. An article comprising an underfill film according to claim 14 adhered to a suitable substrate therefor, wherein said suitable substrate is a polyethylene terephthalate, a polymethyl methacrylate, a polyethylene, a polypropylene, a polycarbonate, an epoxy resin, a polyimide, a polyamide, a polyester, glass, a Si die with silicon nitride passivation, a Si die with polyimide passivation, a BT substrate, bare Si, a SR4 substrate, or a SR5 substrate.

20. The article of claim 19 wherein said article is a flip chip package, a stacked die, a hybrid memory cube, or a TSV device.

21. The article of claim 19 wherein the adhesion of said underfill film to said substrate is at least 5 kg/cm 2 as tested with SiN die/PI die/SiO 2 (size: 3.81×3.81×700 mm 3 ), wherein the die is attached on a BT substrate at 120° C./1 kg force/5 seconds, then cured by ramping the temperature from room temperature to 175° C. over 30 minutes, then held at 175° C. for 5 hrs.