DESIGN TIP: Pad Hold Down Options

Using “Pad Capture by Covercoat”:

This method provides the greatest pad hold down capability of any design method.

Pad Hold Down Options

The examples above show a covercoated pad area in a Type 1 (single-sided) or type 2 (double-sided) applications.

Advantages:

• No need for anchoring spurs, however, fillets should be used.

Disadvantages:

• Cannot be used on tight geometries. Since covercoat sits on top of the pad, there will be excessive adhesive squeeze out onto the pad causing a reduction in solderable annular ring that may violate specification.

Using “Square Pads”:

Advantages:

• If the covercoat access holes are sized properly, there will be adequate pad hold down because the pad will be lapped by the covercoat on four sides.

• Can be used with tight geometries with footnote (see disadvantages below).

• No need for anchoring spurs, however, fillets should be used.

Disadvantages:

• Can be used on tight geometries, however, there may be excessive adhesive squeeze out in the four corners.

For more information on DuPont™ Pyralux® Flexible Circuit Materials, please contact us or visit our website for additional regional contacts.