Start with the joint you need
Bare copper, nickel/gold, silver and process-specific deposited films are not interchangeable. Identify whether the pad will be soldered, sintered, adhesively bonded or wire bonded. State the wire type, solder alloy or attachment material when seeking a finish recommendation.
Specify layer thickness and coverage
A finish name can hide differences in deposition method and thickness. Include the functional stack, areas to be coated and any selective finish requirements. Assess edge coverage and the effect of a barrier layer on electrical and thermal performance where relevant.
Qualify after realistic storage and processing
A fresh sample is not enough to establish production performance. Review cleaning, packaging, storage life, reflow exposure and bond tests. Confirm that the selected test measures the intended joint rather than relying on visual inspection alone.
Engineering example
A board with soldered components and fine gold-wire bonds may need separately qualified pad finishes. A supplier’s general “gold finish” description is too broad to release either joint without detail.
Before you release the design
- State the assembly method for each pad group.
- Specify finish stack, thickness and selective areas.
- Agree on solderability or bond-test acceptance.
Sources and further technical reading
Manufacturer references support the material and process context. Worked examples and checklists are engineering guidance; they are not test results or supplier guarantees.