US 5,225,966 A · Conductive adhesive film techniques

Abstract

A compliant element (23, 25) is provided between an integrated circuit (11) and a substrate (19) which are bonded and interconnected by an anisotropic conductive adhesive (20) comprising conductive particles (21) in a polymer matrix (22). In one embodiment, one set of bonding pads (12, FIG. 2) is coated with a layer (23) of a metal that is significantly softer than the metal from which the conductive particles are made, which permits an oversized conductive particle (21a) to indent into the soft metal layer (23). In another embodiment, one of the sets of bonding pads (15, FIG. 3) is arranged on a relatively thick layer of adhesive (25) which is sufficiently viscous at the temperature at which contact is made to permit the bonding pad (15) to pivot in response to pressure from an oversized conductive particle (21d).

Claims12

Dependent claims

A method for interconnecting first conductors of a first body to second conductors of a second body comprising the steps of:

applying to the second conductor a conductive adhesive comprising an insulating adhesive containing rigid conductive particles of solid metal;
locating the second body such that a plurality of the first conductors are separated by the conductive adhesive from a plurality of said second conductors;
making part of one of the first and second conductors to be of a compliant conductive material that is sufficiently softer than the metal from which the conductive particles are made that it can be deformed around part of a conductive particle during a pressing step;
the conductive particles comprising nickel, and the compliant material being selected from the group consisting of indium and lead/tin solder material;
pressing the first body toward the second body to conductively interconnect first and second conductors;
the compliant conductive material being sufficiently compliant to permit rigid conductive particles of different dimensions to contact simultaneously first and second conductors.

3 more elements

Dependencies are inferred from the claim text.

Conductive adhesive film techniques

Life of this patent

Conductive adhesive film techniques

Life of this patent

Abstract

Claims12