Epoxy, epoxy system, and method of forming a conductive adhesive connection

• US 6,241,915 B1
• Filed: 09/08/1999
• Issued: 06/05/2001
• Est. Priority Date: 02/27/1998
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Lake, Rickie C., Kumar, Krishna
• Primary Examiner(s): Gupta, Yogendra
• Assistant Examiner(s): Hamlin, Derrick G.
• Application Number:
  US09/392,073
• Time in Patent Office: 636 Days
• Field of Search: 252/500, 252/509, 252/510, 252/512, 252/514, 252/519.2, 252/519.33, 252/521.5, 252/521.6, 523/457-459, 523/437, 523/427
• US Class Current: 252/519.33
• CPC Class Codes: C08L 2666/28 Non-macromolecular organic substances
• CPC Class Codes: C08L 2666/54 Inorganic substances
• CPC Class Codes: C08L 63/00 Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• CPC Class Codes: C09J 163/00 Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
• CPC Class Codes: C09J 2463/00 Presence of epoxy resin
• CPC Class Codes: C09J 5/06 involving heating of the applied adhesive
• CPC Class Codes: H01B 1/20 Conductive material dispersed in non-conductive organic material organic macromolecular compounds or compositions C08

Abstract

The invention encompasses epoxies, epoxy systems, and methods of forming conductive adhesive connections between electrical nodes. In one aspect, the invention includes a method comprising: a) providing a first node; b) providing a second node; c) providing a liquid conductive epoxy mixture between the first and second nodes, the liquid conductive epoxy mixture comprising a first liquid and a second liquid, the liquid conductive epoxy mixture having sufficient conductivity that a 15 mil length sample of the liquid conductive epoxy having cross-sectional dimensions of 50 mil by 2 mil would have a resistance of less than about 100 ohms along its length between about 10 minutes and about 20 minutes of combining the first and second liquids; and d) curing the liquid conductive epoxy to form a conductive adhesive connection between the first node and the second node.

Claims

1. An epoxy comprising:

a liquid mixture of a hardener and a base epoxy resin; and

a concentration of an ionic salt within the liquid mixture, the a concentration of the ionic salt being high enough that a 15 mil length sample of the liquid mixture having cross-sectional dimensions of 50 mil by 2 mil would have a resistance of less than about 100 ohms along its length in less than or equal to about 30 minutes of forming the liquid mixture, the concentration of ionic salt being high enough that the 15 mil length sample of the liquid mixture having cross-sectional dimensions of 50 mil by 2 mil would have the resistance of less than about 100 ohms along its length while having a viscosity of less than 100,000 cps. the ionic salt comprising lithium.

2. The epoxy of claim 1 wherein the ionic salt is LiN(CF₃SO₂)₂.

3. The epoxy of claim 1 wherein the ionic salt is LiAsF₆.

4. The epoxy of claim 1 further comprising silver particles.

5. The epoxy of claim 1 wherein the 15 mil length sample has the resistance of less than about 100 ohms in less than or equal to about 10 minutes of forming the liquid mixture.

6. An epoxy comprising:

a liquid mixture of a hardener and a base epoxy resin;

silver particles; and

the ionic salt LiN(CF₃SO₂)₂, a concentration of the ionic salt within the liquid mixture being high enough that a 15 mil length sample of the liquid mixture having cross-sectional dimensions of 50 mil by 2 mil would have a resistance of less than about 100 ohms along its length in less than or equal to about 30 minutes of forming the liquid mixture;

the concentration of ionic salt being high enough that the 15 mil length sample of the liquid mixture having cross-sectional dimensions of 50 mil by 2 mil would have the resistance of less than about 100 ohms along its length while having a viscosity of less than 100,000 cps, the ionic salt comprising lithium.

7. An epoxy comprising:

a liquid mixture of a hardener and a base epoxy resin; and

a concentration of an ionic salt within the liquid mixture, the concentration of the ionic salt being high enough that a 15 mil length sample of the liquid mixture having cross-sectional dimensions of 50 mil by 2 mil would have a resistance of less than about 100 ohms along its length while having a viscosity of less than 100,000 cps, the liquid mixture viscosity remaining less than 100,000 cps for longer than 10 minutes after forming the liquid mixture, the ionic salt comprising lithium.

8. The epoxy of claim 7 wherein the 15 mil length sample would also have a resistance of less than about 100 ohms along its length after being cured.