US 6,270,363 B1 · Z-axis compressible polymer with fine metal matrix suspension

Abstract

A compressible interposer comprising an interposer sheet having a plurality of apertures filled with a dielectric material having a substantially uniform suspension of conductive particles therein forming a plurality of conductive sites. Preferably, the number of conductive sites on the interposer are greater in number than the number of contact pads on the electronic components such that precise alignment of the interposer between the electronic components is not required. The apertures of the interposer sheet confine the conductive particles within the dielectric material such that during compression of the interposer between the electronic components, z-axis conductive pathways are formed without shorting in the x and y directions. Preferably, the interposer sheet comprises polyimide. Preferably, the dielectric material comprises polyimide-siloxane. Preferably, the conductive particles have a diameter of about 2 to about 20 μm and comprise of a material selected from the group consisting of copper, gold, silver, nickel, palladium, platinum, and alloys thereof. The particles may also be coated with an additional conductive material such as solder having a lower melting temperature. Most preferably, the conductive particles comprise solder coated copper particles. The conductive particles are present in an amount of about 30 to about 90 wt. % of the total weight of the conductive particles and the dielectric material.

Claims24

Dependent claims

An interposer for electrically and mechanically connecting electronic components comprising:

an interposer sheet having a plurality of apertures, said sheet comprising an uncured dielectric adhesive;
and,
a dielectric material having a substantially uniform suspension of conductive particles therein, along a z-axis direction, said plurality of apertures substantially filled with said dielectric material, said dielectric material comprising an uncured thermoplastic adhesive, said conductive particles adapted for fusing to provide a metallurgical bond to maintain an electrically conductive path along said z-axis even after delaminating of said interposer.

A method of assembling an electronic module comprising the steps of:

(a) providing a first electronic component having one or more contact pads;
(b) providing a second electronic component having one or more corresponding contact pads;
(c) providing an interposer comprising:
a compressible uncured interposer sheet having a plurality of apertures greater in number than a number of contact pads;
and
a dielectric material having a substantially uniform suspension of conductive particles therein, said plurality of apertures substantially filled with said dielectric material forming a plurality of conductive sites;
(d) aligning said interposer between said first and second electronic components such that at least one conductive site is aligned between a contact pad on said first electronic component and a corresponding contact pad on said second electronic component;
(e) compressing said first and second electronic components and said interposer such that the conductive particles within the at least one conductive site meet in a substantially z-axis direction to provide interconnection between a contact pad on said first electronic component and a corresponding contact pad on said second electronic component;
and,
(f) applying heat during said compressing step for a time and temperature to cure said interposer and simultaneously fuse said conductive particles providing a metallurgical bond to maintain conduction along said z-axis direction.

7 more elements

Dependencies are inferred from the claim text.

Z-axis compressible polymer with fine metal matrix suspension

Life of this patent

Z-axis compressible polymer with fine metal matrix suspension

Life of this patent

Abstract

Claims24