Nickel Plate
We provide a low-stress satin nickel plated from a sulfamate nickel plating solution.
For nickel and gold plating, nickel plating 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), and corrosion resistance of the contact will be degraded. The nickel layer also prevents the copper layer from physically deforming with repeated insertions of contacts.
Nickel plating meets the requirements of QQ-N-290, ASTM B689, AMS 2403, AMS 2424, and MIL-P-27418 specifications.
Gold Plate
Gold plating has exceptional properties such as great electrical and thermal conductivity, superb solderability, and excellent reflectivity of infrared radiation. The gold plating services at Alternate Finishing are of two different approaches: Electrolytic gold plate and electroless gold. Each serves a different purpose.
Hard Gold
In nickel and gold plating, hard gold is used for contacts such as edge board connectors or a keypad on a gold plated PCB board. The hard gold we use is also a solderable gold.
The thickness specified for contacts is either .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 meets the requirements of Mil-G-45204 and Mil-DTL-45204, type I or type II, grade C. It also meets the requirements of ASTM B-488-01, type I or type II, code C.
Soft 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. To meet the desired specifications, the hardness of the plating should not exceed 90 Knoop (25g load). The purity must be 99.7% or greater to meet Type I requirements and 99.9% or greater to meet Type III requirements.
In the past, soft gold plating service required a relatively thick deposit when wire bonding with gold wire was going to be used. It was often specified at 100 microinches minimum.
Advancements in wire bonding equipment and technique now allow bonding to be performed at a thickness as low as 0.3 microns (12 microinches), however, most still specify 1.3 microns (50 microinches) minimum, although it’s important to note that the thickness for nickel and gold plating can vary depending on the application and industry standards. This gold meets the requirements of Mil-G-45204 and Mil-DTL-45204, type III, grade A. It also meets the requirements of ASTM B-488-01, type III, Code A
Electroless Gold
With our electroless gold plating service, circuits can be etched and plated in their final configuration. This saves steps and allows the circuit design to take priority.
The gold deposited is wire-bondable and solderable. It is essentially identical to an electrolytic pure gold deposit according to Mil-DTL-45204 or ASTM B488 type III grade A regarding thickness, hardness and purity.
Electrolytic plating results in deposits with thickness discrepancies primarily influenced by the shape of the electrical field between cathode and anode surfaces.
These variations manifest as thicker deposits on corners, edges, and surfaces closer to the anode, while thinner layers are observed on flat surfaces, inside holes, and areas facing away from the anode.
In contrast, electroless nickel and gold plating eliminates this issue entirely. It ensures uniform thickness of gold-plated deposits, regardless of corners, sides, or internal structures such as deep holes.
