Alternate Finishing, Inc.

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Plating ceramic substrates

Gold Plate: We can provide two different types electrolytic gold plate. Each serves a different purpose.
: Soft Gold; "Soft" or "bondable" gold is specified most frequently on thin film. This gold is specified when the assembly operations require wire bonding with gold wire. The purity and hardness of bondable soft gold must be closely monitored and controlled. The hardness must be 90 Knoop (25g load) or less. The purity must be 99.9% or greater.; In the past, wire bonding with gold wire was thought to require a relatively thick deposit. It was often specified at 100 micro-inches minimum. Advancements in wire-bonding equipment and technique now allow bonding to be performed at a thickness as low as .3 microns (12 micro-inches), however most still specify 1.3 microns (50 micro-inches) minimum.; This gold used to be specified as required to meet Mil-G-45204, type III, grade A. On new products it is to be specified to meet the requirements of ASTM B-488-01, type III , Code A.; Hard Gold; The other type is known as "hard" gold. It is almost never specified for thin-film circuits. It is usually used for contacts such as edge board connectors or a key pad. The hard gold we use is also a solderable gold. The thickness specified for contacts is .8 microns (30 micro-inches) minimum or 1.3 microns (50 micro-inches minimum). The thickness specified for solderability should be a maximum of .8 microns (30 micro-inches).; This gold is often specified as required to meet Mil-G-45204, type II, grade C. It can also be specified to meet ASTM B-488-01, type I or type II, code C.


Copper Plate: We provide a smooth even deposit from a copper sulfate plating solution.
Copper plating is used in higher voltage applications. We have plated thickness as high as .004" with a tolerance of +/- .0003".

Nickel Plate: We provide a low stress satin nickel plated from a sulfamate nickel plating solution.
Nickel plating serves several functions: First it is a barrier layer which prevents the diffusion of copper into the gold top layer. If the copper is diffused into the gold the electrical characteristics (i.e. contact resistance), of the contact will be degraded.