NOVEL HARDENER FOR EPOXY MOLDING COMPOUNDS

• US 20020128354A1
• Filed: 01/05/2001
• Published: 09/12/2002
• Est. Priority Date: 01/05/2001
• Status: Active Grant

• Current Assignee: Cookson Singapore Pte Ltd (Vesuvius Plc)
• Original Assignee: Cookson Singapore Pte Ltd (Vesuvius Plc)
• Inventors: Garrett, David William
• Granted Patent: US 6,437,026 B1
• Time in Patent Office: Days
• US Class Current: 523/463
• CPC Class Codes: C08L 2666/20 Macromolecular compounds having nitrogen in the main chain according to C08L75/00 - C08L79/00; Derivatives thereof
• CPC Class Codes: C08L 63/00 Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• CPC Class Codes: C08L 79/04 Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: H01L 23/293 Organic, e.g. plastic
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

The invention is directed to novel epoxy molding compounds for the encapsulation of microchips in the electronics industry. Known epoxy molding encapsulants are generally prepared from a blend epoxy resins, phenol hardeners, silica fillers, catalysts, flame retardant materials, processing aids and colorants. The addition of polybenzoxazines as a co-reactant with one or several epoxy resins provides a product with reduced moisture adsorption while maintaining a high glass transition temperature.

Claims

1. An epoxy molding compound comprising:

from about 5-30% by weight of an epoxy resin;

from about 0-30% by weight of a resin hardener;

from about 60-90% by weight of a filler;

from about 2-30% by weight of polybenzoxazine based on the total weight of the compound composition, and which co-reacts with the epoxy resin; and

an effective amount of a catalyst for the reaction between the epoxy resin and the polybenzoxazine.

2. The epoxy molding compound of claim 1, wherein the epoxy resin or a combination of two or more epoxy resins, is selected from the group consisting of diglycidyl ether of bisphenol-A oligomers, diglycidyl ether of bisphenol-F oligomers, polyglycidyl ether of novolac oligomers, polyglycidyl ether of cresol novolac oligomers, polyglycidyl ether of naphthalenic phenol oligomers, triglycidyl ether of triphenolmethane oligomers, diglycidyl ether of biphenol oligomers and the methyl, ethyl propyl, butyl, tertiary butyl substituted version of these resins.

3. The epoxy molding compound of claim 2, wherein the epoxy resin is the triglycidyl ether of triphenolmethane oligomers.

4. The epoxy molding compound of claim 1, wherein the resin hardener or a combination of two or more resin hardeners, is selected from the group consisting of diglycidyl ether of bisphenol A, diglycidyl ether of bispehnol F, triglycidyl ether of triphenol methane, polyglycidyl ether of novolac, polyglycidyl ether cresol novolacs, polyglycidyl ether naphthalenic phenols, naphthalenic phenols, polybisphenol A, polybisphenol F, (poly(triphenolmethane) and methyl, ethyl, propyl and butyl substituted versions of these resins

5. The epoxy molding compound of claim 4, wherein the resin hardener is a triphenolmethane oligomer.

6. The epoxy molding compound of claim 1, wherein the filler is silica filler.

7. The epoxy molding compound of claim 6, wherein the silica filler is comprised of spherical, angular and fused silica and combinations thereof.

8. The epoxy molding compound of claim 6, wherein the silica filler comprises particles in the range from 0.5 to 40 microns in size.

9. The epoxy molding compound of claim 1, wherein the polybenzoxazines is comprised of bisphenol-A, aniline and formaldehyde.

10. The epoxy molding compound of claim 1, wherein the catalyst is present in an amount from 0-15% by weight based on the total weight of the compound composition.

11. The epoxy molding compound of claim 10, wherein the catalyst or a combination of two or more catalysts is selected from the group consisting of imidazoles, amines and phosphines containing an electron withdrawing group.

12. The epoxy molding compound of claim 11, wherein the imidazoles are selected from the group consisting of benzamidazole, 2-methylimidazole, 2-phenylimidazole.

13. The epoxy molding compound of claim 11, wherein the amines are selected from the group consisting of 4-dimethylaminopyridine and adipic acid.

14. The epoxy molding compound of claim 11, wherein the phosphine is tris(2,6-dimethoxyphenol) phosphine.

15. The epoxy molding compound of claim 1, further comprising from about 0-2% by weight of a silane coupling agent.

16. The epoxy molding compound of claim 15, wherein the silane coupling or a combination of two or more silane coupling agents is selected from the group consisting of glycidoxypropyltrimethoxysilane, glycidoxypropyltriethoxysilane, aminopropyltriethoxysilane, aminopropyltrimethoxysilane, vinlytriethoxysilane, vinlytrimethoxysilane, acryloxypropyltriethoxysilane, acryloxypropyltrimethoxysilane, ureidopropyltriethoxysilane, ueidopropyltrimethoxysilane, mercaptopropyltriethoxysilane, and mercaptopropyltrimethoxysilane.

17. The epoxy molding compound of claim 16, wherein the silane coupling agent is glycidoxypropyltrimethoxysilane.

18. The epoxy molding compound of claim 1, further comprising from about 0-5% by weight of a processing aid.

19. The epoxy molding compound of claim 18, wherein the processing aid may comprise one or more oils and waxes.

20. The epoxy molding compound of claim 19, wherein the processing aid is stearic acid.

21. The epoxy molding compound of claim 1, further comprising from about 0-10% by weight of a flame retardant material.

22. The epoxy molding compound of claim 21, wherein the flame retardant material or a combination of two or more flame retardant materials is selected from the group consisting of brominated epoxies, brominated phenolics, antimony oxides, zinc molybdates, zinc borates, magnesium hydroxide, aluminum hydroxide, polyphosphoric acid, red phosphorus and aromatic phosphates.

23. The epoxy molding compound of claim 1, further comprising from about 0-5% by weight of pigment or dye.

24. The epoxy molding compound of claim 23, wherein the pigment or dye is selected from the group consisting of carbon black, nigrosine, lamp black and furnace black.

25. An epoxy molding compound comprising:

from about 5-30% by weight of an epoxy resin comprising triglycidyl ether of triphenolmethane oligomers;

from about 0-30% by weight of a resin hardener comprising a triphenol methane oligomer;

from about 60-90% by weight of a fused silica filler;

from about 2-30% by weight of polybenzoxazine, which co-reacts with the epoxy resin;

from about 0-2% by weight of a silane coupling agent;

from about 0-5% by weight of a processing aid;

from about 0-10% by weight of a flame retardant material;

from about 0-5% by weight of pigment or dye; and

from about 0-15% by weight of an imidazole catalyst for the reaction between the epoxy resin and the polybenzoxazine, all of the foregoing being based on the total weight of the composition.

26. An epoxy molding compound having decreased moisture adsorption and a high glass transition temperature, which comprises:

7.2% by weight of an epoxy resin;

0.6% by weight of a resin hardener;

77.5% by weight of silica fillers;

8.6% by weight of polybenzoxazine based on the total weight of the compound composition, and which co-reacts with the epoxy resin; and

0.1% by weight of an effective amount of a catalyst for the reaction between the epoxy resin, hardener and the polybenzoxazine.