Mono-functional monomers and methods for use thereof

Abstract

The invention is based on the discovery that adhesive compositions containing certain low-viscosity, mono-ethylenically unsaturated monomers have surprisingly good cure parameters, resulting in very little weight loss upon cure. Many of these monofunctional monomers used alone or in combination with other monofunctional monomers described herein have high glass transition temperatures when cured. Moreover, since these monomers are monofunctional the crosslink density of the adhesive composition does not increase (relative to multi-functional monomers), which in turns results in lower stress, lower modulus adhesive compositions. As such, these monomers are useful in a variety of thermoset adhesive compositions, such as for example, die attach adhesive compositions.

Description

Claims

1. An adhesive composition comprising a thermosetting resin and at least one monomer having the structure

2. The adhesive composition of claim 1, wherein R2 is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, phenyl, or cyclohexyl.

3. The adhesive composition of claim 1, wherein R2 is methoxy, ethoxy, propyloxy, or phenoxy.

4. The adhesive composition of claim 1, wherein R2 is fluoride, chloride, or bromide.

5. The adhesive composition of claim 1, wherein R2 is —O(CO)—R3, wherein R3 is C1-C5 alkyl.

6. The adhesive composition of claim 1, wherein the composition has a Tg of at least 50° C.

7. The adhesive composition of claim 1, wherein the composition has a Tg of at least 100° C.

8. The adhesive composition if claim 1, wherein the composition has a Tg of at least 150° C.

9. The adhesive composition if claim 1, wherein the composition has a Tg of at least 200° C.

10. The adhesive composition of claim 1, wherein the thermosetting resin is selected from acrylates, methacrylates, maleimides, vinyl ethers, vinyl esters, styrenic compounds, allyl functional compounds, epoxies, oxetanes, oxazolines, or benzoxazines.

11. The adhesive composition of claim 1, further comprising a filler.

12. The adhesive composition of claim 11, wherein the filler is conductive.

13. The adhesive composition of claim 12, wherein the filler is thermally conductive.

14. The adhesive composition of claim 12, wherein the filler is electrically conductive.

15. A method for increasing Tg of a thermosetting resin without significantly increasing modulus of the resin, comprising incorporating into the thermosetting resin at least one compound having the structure:

16. The adhesive composition of claim 15, wherein R2 is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, phenyl, or cyclohexyl.

17. The adhesive composition of claim 15, wherein R2 is methoxy, ethoxy, propyloxy, or phenoxy.

18. The adhesive composition of claim 15, wherein R2 is fluoride, chloride, or bromide.

19. The adhesive composition of claim 15, wherein R2 is —O(CO)—R3, wherein R3 is C1-C5 alkyl.

20. A method for producing a thermosetting resin having a Tg value greater than about 100° C. without significantly increasing modulus, comprising incorporating into the thermosetting resin at least one compound having the structure:

21. A method for attaching a semiconductor die to a substrate comprising: (a) applying the adhesive composition of claim 1 to the substrate and/or the semiconductor die,(b) bringing the substrate and the die into contact to form an assembly, wherein the substrate and the die are separated only by the die attach paste applied in (a), and,(c) subjecting the assembly to conditions suitable to cure the die-attach paste, thereby adhesively attaching the semiconductor die to the substrate