Grafted Metallized Particle Interconnect (G. M. P. I.)

Abstract

AbstractAn electrical contact surface is described which combines the flexibility of a low resistance elastic interface with bonded conductive particles for penetration during compressive mating to metallic oxide layers. The processes for applying both technologies is described including the types of interfacial bonds provided. Both technologies permit high conductivity across the layers. Such technologies offer advantages for connectors requiring low normal forces, superior oxidative resistance to the environment, elastic conductors with the same resistance as bare copper, and high volume processing capabilities.The first layer of conductive coating includes grafting an elastomeric bridge from the primary surface to the outer layer of metal particles and flakes. The secondary outer coating involves deposition of sharp, hard, conductive particles onto the grafted surface. Each coating bonds to the other forming several layers outward from the primary elastomeric substrate.Product applications include a conductive elastic interface for interconnecting a BGA to a PCB via a socketed solution. The elastomeric interface overcomes co‐planarity issues associated with mating the BGA chip to a PCB. Compressive forces are reduced as compared to metal connectors providing lower total force for high I/O counts. Environmental constraints are reduced due to the durability of the elastomeric system.