Alternate Finishing, Inc.

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Nickel and Gold Electroplating

Automated Process available for larger parts and quantities
Solderable surface
Bondable gold available
Panel plate small circuits with edge connectors


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), corrosion resistance of the contact will be degraded. Second, it is also used as a barrier between tin and copper to prevent the formation of copper-tin intermettallics. This can be important when the product must operate in high temperature environments. The third function of the nickel layer is, it prevents the copper layer from physically deforming with repeated insertions of the contacts.

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Gold Plate: We can provide two different types electrolytic gold plate. Each serves a different purpose.; Hard Gold; The first type is known as "hard" gold. 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 microinches) minimum or 1.3 microns (50 microinches minimum). The thickness specified for solderability should be a maximum of .8 microns (30 microinches).; 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.

[top]: Soft Gold; The other type is known as "soft" or "bondable" gold. 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 99.7% or greater.; In the past, wire bonding with gold wire was thought to require a relatively thick deposit. It was often specified at 100 microinches minimum. Advancements in wirebonding equipment and technique now allow bonding to be performed at a thickness as low as .3 microns (12 microinches), however most still specify 1.3 microns (50 microinches) minimum.; This gold is often specified as required to meet Mil-G-45204, type III or type I, grade A. It can also be specified to meet the requirements of ASTM B-488-01, type I or type III , Code A.
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Our Requirements: The service we provide can be applied to your parts in one of the following ways.; We can pattern plate the whole panel. We need to receive the panel after your copper plating operation, with the photo-resist still on the panel. There should not be any tin or tin-lead exposed.

Selected areas internal to the circuit can be plated. The most frequent way this is accomplished is: After you plate your parts with copper and tin, a second image is applied that only shows the areas that require gold. Strip the exposed tin before sending us your parts.; If you can provide us with an accurate surface area to be plated, it is a great help to us, both in providing you with an accurate quote and in setting up our process parameters.

We plate panels that have many different brands of photo-resist and do not recommend any particular brand or model. However, please follow closely any recommendations that your photo-resist supplier has regarding preparing panels for deep gold plating. The nickel / gold plating process is not as forgiving as the normal copper / tin process. If the application of the photo-resist is not in control then it may lose adhesion in the process and plating may get under it.