US 5,853,622 AGranted

Transient liquid phase sintering conductive adhesives

AssigneeOrmet Corporation

InventorsCatherine Gallagher, Goran Matijasevic, M. Albert Capote

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Abstract

An inventive method for electrical and thermal electronic component attachment is disclosed. The combination of transient liquid phase sintering (TLPS) and a permanent adhesive flux binder provides the advantages of both conventional soldering technology and conductive adhesives. This hybrid approach delivers electrical and thermal conduction through sintered metal joints and mechanical properties based on a tailorable polymer matrix. These transient liquid phase sintering conductive adhesives can utilize conventional dispensing, placement, and processing equipment. During the reflow process, metal powders in the composition undergo interparticle sintering as well as alloying to the contact pads. This process produces a strong mechanical, thermal, and electrical interconnect which ensures good conductivity that is also resistant to humidity and temperature cycling.

Claims20

Dependent claims

A conductive adhesive composition comprising:

in the range of about 5 up to about 65% by volume of a high melting point metal, wherein said metal is in the form of a substantially spherical powder,
in the range of about 5 up to about 60% by volume of a low melting point metal or metal alloy, wherein said metal or metal alloy is in the form of a substantially spherical powder,
in the range of about 2 up to about 60% by volume of a chemically protected crosslinking agent, wherein said chemically protected crosslinking agent is an acid or strong base which has been chemically modified by the addition of a chemically or thermally triggered species to become reactive only at or near the time the low melting point metal or metal alloy, or an alloy thereof with said high melting point metal melts,
in the range of 0 up to about 35% by volume of a resin,
in the range of 0 up to about 35% by volume of a reactive monomer or polymer that is not the same as said resin, and
in the range of 0 up to about 10% by volume of a metal additive,
with the proviso that said composition must contain either said resin and/or said reactive monomer or polymer, or, in the alternative, said resin and/or said reactive monomer or polymer can be combined with said chemically protected crosslinking agent to produce a single component of said composition.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/704,467Filed 28 Aug 1996 · continuation in part
Priority: 9 Feb 1990
Granted: 29 Dec 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification21 codes

B22F 3/1035
Sintering only: liquid phase sintering
B23K 35/0222
Characterised by mechanical features, e.g. shape: for use in soldering or brazing
B23K 35/36
Characterised by the composition or nature of the material: selection of non-metallic compositions, e.g. coatings or fluxes ; Selection of…
H01B 1/22
Conductive material dispersed in non-conductive organic material: the conductive material comprising metals or alloys

Family

Serial477,678Parent of this continuation-in-part · filed 9 Feb 1990
Serial769,892Parent of this division · filed 1 Oct 1991
Serial324,060Parent of this continuation-in-part · filed 17 Oct 1994
Serial483,079Parent of this continuation-in-part · filed 7 Jun 1995
US 5,716,663 AParent of this continuation-in-part
US 5,376,403 AParent of this division
US 5,853,622 AThis patent

From the US filing history. Foreign family members aren’t listed.