12.3 Advanced Technology | Partially Electroplated Nickel/Gold
There are two typical manufacturing processes for partial electroplated gold, with drilling/milling off connecting conductors or with etching away connecting conductors. As partial electroplating gold is an electroplating/electrolytic process, in both cases the layout parts to be gold-plated, such as direct connectors, meander switches, slip rings and other electroplated gold surfaces, must be electrically connected to each other and/or via the PCB contour to the edge of the production panel using so-called "connecting conductors" in the layout. So-called leading or lagging contacts for direct connectors are possible in both cases. This additional layout of the connecting conductors is designed by the customer or by KSG in consultation with the customer.
Drilling/Milling off Connecting conductors
In this case, the connecting conductors required for the electroplated gold plating are drilled off during mechanical finishing and/or milled off during milling of the PCB contour. This restores the actual electrical circuit.
Etching away Connecting conductorss (Advanced)
In this case, the connecting conductors required for the galvanic gold plating are etched away again with an additional etching mask after gold plating. This restores the actual electrical circuit.
Download process sequence/production principle partially electroplated Nickel/Gold – drilling/milling off connecting conductors
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Download process sequence/production principle partially electroplated Nickel/Gold – etching away connecting conductors
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Features & Advantages
- Simpler creation of layout and production documents
- More cost-effective Design to Cost, as fewer process steps are required
Challenges
- Separation holes requir more space between pads and other layout parts
- Electrical potential is present at the cut edges of the drilled or milled connecting conductors
Features & Advantages
- Smaller distances between pads and other layout parts possible
- No open electrical potential of the etched connecting conductor tracks if a solder resist is present
Challenges
- Creation of layout and production documents somewhat more complex
- Higher copper thicknesses are hardly possible as they are more difficult to embed media-tight with the etching mask for the connecting conductors
- Slightly more expensive due to more necessary process steps
Keywords
- Selective gold plating
- Plating tie bars
- Surface finishes
- Connectors
- Design guidelines