New options for Chemical Nickel-Gold surface finish

Figure 1

Internet headline 2 October 2015

The price of gold has risen by nearly 250% over the past few years. So accurate costing is essential both for our customers and ourselves.

We have made some changes in the way we calculate chemical nickel-gold (Che Ni/Au) prices. Previously we had 2 options:

  • Che Ni/Au selective: the nickel/gold surface finish was applied only to the copper exposed by the soldermask.
  • Che Ni/Au overall: this covered 2 situations: cases where the customer required nickel-gold over the whole board but under the soldermask; and cases where there was no soldermask on one or both sides.

Now we offer a choice of 3 options:

  1. Che Ni/Au selective
  2. Che Ni/Au sel. – large area
  3. Che Ni/Au before soldermask

Che Ni/Au selective and Che Ni/Au sel. – large area

For Che Ni/Au selective and Che Ni/Au sel. – large area the nickel/gold surface finish is applied only to the copper exposed by the soldermask. If the exposed copper covers less than 40% of the board surface choose Che Ni/Au selective; if it covers more, choose Che Ni/Au sel. – large area. The percentage of exposed (or “free”) copper is calculated in real time and shown in the DFM section of PCB Checker.

Both Che Ni/Au selective and Che Ni/Au sel. – large area are pooling options.

How to use the new options when specifying Che Ni/Au surface finish?

  1. Select Che Ni/Au selective in the price calculator menu.
  2. To get the final PCB price, upload your data to allow PCB Visualizer to calculate the free copper area.
  3. Open PCB Visualizer in your Shopping basket.
  4. For most PCBs the free copper will be less than 40% of the board area, so Che Ni/Au selective will be correct. When you open the Shopping basket, there will be a green tick in the PCB Visualizer column (assuming that there are no other issues).
  5. If the free copper is more than 40% of the board area on the top or bottom layer (typically where there is no soldermask on top and/or bottom layers), there will be a red flag in the PCB Visualizer column. Click the item to open PCB Configurator/PCB Checker. A Remarks message will advise you to change to Che Ni/Au sel. – large area. The PCB price will rise slightly. Click the “PCB Checker” and “DFM information” tabs to see the exact values.
  6. If you have selected Che Ni/Au sel. – large area and the free copper percentage is less than 40% of the board area, a message will advise you to switch to Che Ni/Au selective.
    TIP
    If you have selected Che Ni/Au sel. – large area when calculating the price and the free copper area is less than 40%, PCB Visualizer will show a green tick (as the job is producible). If you have selected Che Ni/Au sel. – large area in the pricing menu always click the item in the basket and check for the warning message.
  7. The new price for boards with Che Ni/Au surface finish and no soldermask on top or bottom layers is significantly lower than the present Che Ni/Au overall price.

Che Ni/Au before soldermask

This is now a separate option. As it is rarely specified and requires a special process route, it cannot be pooled. It is now a non-poolable option. In case you have chosen it by mistake you will receive a warning message.

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