Staking, Bonding, and Conformal Coating are workmanship techniques that bond electrical and mechanical parts to printing wiring boards (PWBs) or other surfaces and provides an electrically nonconductive, and protective coating for those parts. These techniques are covered by NASA-STD 8739.1. As with any workmanship, ensure facility cleanliness, proper environmental conditions, tool and equipment control including calibration, proper material storage and shelf life control, and handling. Also ensure proper ESD control.
Ensure solutions are testing for contamination. This can be done with an ionograph (pictured below).
Prior to staking, bonding, and conformal coating:
- Prepare surface
- Mask materials
- Use Primer when required
- Properly prepare all materials
- Multiple options are available for use in conformal coating. Further research should be conducted to determine which coating will best suit the need at hand.
- If conformal coating equipment and materials are not available, pursue outsourcing the task to a experienced vendor.
The information on the following sections is taken from the NASA Training Program Student Workbook for Polymeric Applications & Inspection.