US4975221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High purity epoxy formulations for use as die attach adhesives
Assignee: National Starch and Chemical Investment Holding Corp
•
Filing: 1989-05-12
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Granted: 1990-12-04
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Expires: 2009-05-12
Abstract
Abstract This invention presents improved epoxy-based die attach adhesives which are of low viscosity, high ionic purity, and stable toward thermal cycling. This improvement is obtained by including in the formulation carboxy terminated polymers which are the reaction products of polyether diols with cyclic dianhydrides.
Inventors
- 👤 Shuhchung S. Chen
- 👤 Jules E. Schoenberg
- 👤 Song Park
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:09
CPC Classifications
C; C09; C09J; C09J163/00; H; H10; H10W; H10W72/00; H10W72/30; C08; C08L; C08L2666/00; C08L2666/02; C08L2666/14; C08L2666/22; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31529
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
131 words
In an epoxy-based die-attach adhesive composition, wherein the adhesive comprises one or more curable epoxy compounds, a conductive filler, and suitable curing agents the improvement comprising adding to said adhesive 2-50 PHR (by wt.) of an epoxy modifier which comprises a carboxy-terminated polymer of the general formula: ##STR6## wherein R' is a C 2 -C 20 straight or branched chain or cyclic saturated or unsaturated hydrocarbon, R is a linear hydrocarbon having ether linkages or linear hydrocarbons substituted with sulfone, sulfide, phosphonate, phosphine oxide, silane, or siloxane, preferably a linear hydrocarbon having ether linkages, X is O, NH, or NR", R" is C 1 -C 10 alkyl, alkenyl, or aryl, and n is at least 1, such that the die attach adhesive is of low viscosity and stable toward thermal cycling.
Claim 2
Dependent Claim
131 words
In an epoxy-based die-attach adhesive composition, wherein the adhesive comprises one or more curable epoxy compounds, a conductive filler, and suitable curing agents the improvement comprising adding to said adhesive 2-50 PHR (by wt.) of an epoxy modifier which comprises a carboxy-terminated polymer of the general formula: ##STR6## wherein R' is a C 2 -C 20 straight or branched chain or cyclic saturated or unsaturated hydrocarbon, R is a linear hydrocarbon having ether linkages or linear hydrocarbons substituted with sulfone, sulfide, phosphonate, phosphine oxide, silane, or siloxane, preferably a linear hydrocarbon having ether linkages, X is O, NH, or NR", R" is C 1 -C 10 alkyl, alkenyl, or aryl, and n is at least 1, such that the die attach adhesive is of low viscosity and stable toward thermal cycling.
Claim 3
Dependent Claim
27 words
The epoxy-based die attach adhesive of claim 1, wherein the carboxy terminated polymer added to the adhesive is about 2-50 parts per hundred parts epoxy by wt.
Claim 4
Dependent Claim
30 words
The epoxy-based die attach adhesive of claim 1, wherein the epoxy compound is selected from the group consisting of diglycidyl ethers of polyhydric phenols, trisepoxides, aliphatic diepoxides, and cycloaliphatic diepoxides.
Claim 5
Dependent Claim
18 words
The epoxy-based die attach adhesive of claim 1, wherein the carboxy terminated polymer is admixed with the epoxy.
Claim 6
Dependent Claim
18 words
The epoxy-based die attach adhesive of claim 1, wherein the carboxy terminated polymer is prereacted with the epoxy.
Claim 7
Dependent Claim
46 words
The epoxy-based die attach adhesive of claim 1, wherein the carboxy terminated polymer is the formula ##STR7## wherein R' is a C 2 -C 20 straight or branched chain or cyclic saturated or unsaturated aliphatic or aromatic hydrocarbon, R is a linear polyether, X is O.
Claim 8
Dependent Claim
22 words
The epoxy-based die attach adhesive of claim 6 ,wherein the linear polyether has a molecular weight of about 500 to about 5000.
Claim 9
Dependent Claim
18 words
The epoxy-based die attach adhesive of claim 6 wherein R is ##STR8## wherein n is at least 8.
Claim 10
Dependent Claim
17 words
The epoxy-based die-attach adhesive of claim 6 wherein R is ##STR9## wherein n is at least 6.
Claim 11
Dependent Claim
53 words
The epoxy-based die attach adhesive of claim 1, which comprises 100-125 parts (by wt) of one or more epoxy compounds, 3-50 parts (by wt) of carboxy terminated polymer modifier, 0-20 parts (by wt) curing agent, 2.5-10 parts (by wt) catalyst, 0-2 parts (by wt) adhesion promoter, and 300-600 parts (by wt) conductive filler.
Claim 12
Dependent Claim
33 words
The epoxy-based die attach adhesive of claim 1, wherein the conductive filler is a thermally conductive filler selected from the group consisting of magnesium oxide, calcium barbonate, silicon dioxide, titanium dioxide, and alumina.
Claim 13
Dependent Claim
34 words
The epoxy-based die attach adhesive of claim 1, wherein the conductive filler is an electrically conductive filler selected from the group consisting of powdered or flaked, or a mixture of powdered and flaked metal.
Claim 14
Dependent Claim
27 words
The epoxy-based die attach adhesive of claim 12 wherein the curing agent is selected from the group consisting of phenol novalacs, aromatic amines, aromatic diamines, and dicyandiamides.
Claim 15
Dependent Claim
25 words
The epoxy-based die attach adhesive of claim 8, wherein the catalyst is selected from the group consisting of substituted ureas, substituted imidazoles, and tertiary amines.
Claim 16
Dependent Claim
13 words
The epoxy-based die attach adhesive of claim 14, wherein the catalyst is dimethylbenzylamine.
Claim 17
Dependent Claim
23 words
The epoxy-based die attach adhesive of claim 12, wherein the metal is selected from the group consisting of silver, gold, copper, and nickel.
Claim 18
Dependent Claim
13 words
A semiconductor device mounted on a substrate with the adhesive of claim 1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |