Low temperature flexible die attach adhesive and articles using same

• US 5,489,637 A
• Filed: 02/22/1995
• Issued: 02/06/1996
• Est. Priority Date: 05/28/1992
• Status: Expired due to Term

• Current Assignee: Henkel Corporation (Henkel AG & Co KGaA)
• Original Assignee: Johnson Matthey Incorporated (Johnson Matthey PLC)
• Inventors: Nguyen, My N., Chien, Yuan Y.
• Primary Examiner(s): CAIN, EDWARD J
• Application Number:
  US08/392,602
• Time in Patent Office: 349 Days
• Field of Search: 524/377, 524/381, 524/382, 528/361, 528/362, 528/363, 528/422
• US Class Current: 524/377
• CPC Class Codes: C07C 261/02 Cyanates
• CPC Class Codes: C08G 59/4007 Curing agents not provided for by the groups C08G59/42 - C08G59/66
• CPC Class Codes: C08K 5/0016 Plasticisers
• 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: C09J 179/04 Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: G06K 19/077 Constructional details, e.g. mounting of circuits in the carrier
• CPC Class Codes: G06K 19/07745 Mounting details of integrated circuit chips
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H01L 2224/29 of an individual layer connector
• CPC Class Codes: H01L 2224/29099 Material
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29199 Material of the matrix
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29299 Base material
• CPC Class Codes: H01L 2224/29339 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/8319 Arrangement of the layer connectors prior to mounting
• CPC Class Codes: H01L 2224/8385 using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 23/3737 Organic materials with or without a thermoconductive filler
• CPC Class Codes: H01L 23/4828 Conductive organic material or pastes, e.g. conductive adhesives, inks
• CPC Class Codes: H01L 23/49855 for flat-cards, e.g. credit cards cards per se G06K19/00
• CPC Class Codes: H01L 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/83 : using a layer connector
• 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 2924/00013 : Fully indexed content
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01067 : Holmium [Ho]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/07802 : not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/15747 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2924/3512 : Cracking

Abstract

Described is a flexible adhesive formulation for bonding a semiconductor device to a flexible substrate and a flexible card containing a semiconductor device which can be processed in a computer.

Claims

1. A method of making a cyanate ester flexible which comprises reacting the cyanate ester with at least one flexibilizer having a glass transition temperature less than about 25°

C., and comprising at least one member from the group consisting of compounds containing hydroxyl groups having a molecular weight of about 200 to 5000, compounds containing amine and compounds containing epoxide reactive functional groups, or mixtures thereof, to produce a formulation having a viscosity of about 5 to 50 poise and a radius of curvature of about 1 meter or more.

6. A method according to claim 1 wherein said cyanate ester is reacted with an amine reactive functional group.

7. A method according to claim 1 wherein said cyanate ester is reacted with an epoxide reactive functional group.

8. A method according to claim 1 wherein said method comprises reacting cyanate ester with an amine reactive functional group.

9. A method according to claim 1 wherein said method comprises reacting cyanate ester with an epoxide reactive functional group.

11. A method according to claim 1 wherein said cyanate ester comprises an adhesive formulation suitable for bonding a semiconductor device to a substrate and further comprises a thermally and/or electrically conductive filler.

15. A method according to claim 1 wherein said cyanate ester comprises an adhesive formulation suitable for bonding a semiconductor device to a substrate and further comprises a thermally and/or electrically conductive filler.

16. A method according to claim 15 wherein said filler comprises silver.

17. A method according to claim 15 wherein said adhesive formulation further comprises a curing catalyst.

2. A method of making a cyanate ester flexible which comprises reacting the cyanate ester with at least one flexibilizer having a glass transition temperature less than about 25°

C. comprising at least one polyhydroxyl polymer compound having a molecular weight of about 200 to about 5000 from the group of polyhydroxyl polymer compounds within at least one of the following formulas;

space="preserve" listing-type="equation">HO--(CH.sub.2).sub.m --CO--O--(CH.sub.2).sub.n OH,

and

space="preserve" listing-type="equation">HO--(CH.sub.2).sub.m --O--C--O--R--C--O--(CH.sub.2).sub.n --OH

to produce a formulation having a viscosity of about 5 to 50 poise and a radius of curvature of about 1 meter or more.

3. A method according to claim 2 wherein said polyhydroxyl polymer compound is one from the group consisting of polyhydroxyl polyesters and polyhydroxyl polyethers.

4. A method according to claim 2 wherein said cyanate ester further includes a metal containing co-curing catalyst.

12. A method according to claim 2 wherein said filler comprises silver.

13. A method according to claim 2 wherein said adhesive formulation further comprises a curing catalyst.

14. A method according to claim 3 wherein said adhesive formulation further comprises an alkylphenol.

5. A method of rendering a cyanate ester flexible which comprises adding to the cyanate ester at least one polyhydroxyl polymer compound having a glass transition temperature less than about 25°

C. and a molecular weight range of about 200 to about 5000 within at least one of the following formulas;

space="preserve" listing-type="equation">HO--(CH.sub.2).sub.m --CO--O--(CH.sub.2).sub.n --OH

and

space="preserve" listing-type="equation">HO--(CH.sub.2).sub.m --O--C--O--R--C--O--(CH.sub.2).sub.m --OH

or mixtures thereof, and grafting such polymer to the cyanate ester molecular structure.

18. A method according to claim 5 wherein said cyanate ester comprises an adhesive formulation suitable for bonding a semiconductor device to a substrate further comprising adding a thermally and/or electrically conductive filler.

19. A method according to claim 18 wherein said filler comprises silver.

20. A method according to claim 18 further comprising adding a curing catalyst.

10. A method of making a cyanate ester flexible which comprises reacting 4 to 16 wt. % cyanate ester with 6 to 24 wt. % of at least one flexibilizer having a glass transition temperature less than about 25°

C. containing one reactive functional group from the group of hydroxyl, amine and epoxide reactive functional groups, or mixtures thereof, wherein flexibilizers containing hydroxyl reactive functional groups have a molecular weight in the range of about 200 to about 5000.