Why vacuum molded PCB Transformers is Important

Why vacuum molded PCB Transformers is Important

Potting hazards:

Potential for cavitation, leading to partial discharge, hot spots, and thermal cycling cracks
Service life may be reduced by 40–60%

Advantages of vacuum potting:

Evacuates air at ≤5 mbar
Injects UL94V-0 epoxy resin and cures in a moisture-free environment
Significantly improves insulation performance and thermal stability

Actual Results and Test Data

A vacuum-potted medical device transformer passed a 50,000-hour accelerated aging test.
A non-vacuum-potted device failed after 18,000 hours.

Ability to cope with extreme environments

Recommendations for verifying potting quality

–Don’t rely solely on the datasheet, request:
–X-ray scan showing void distribution
–Cross-section report measuring bubble size
–Thermal shock test (-55°C to +150°C, 500 cycles)
–Partial discharge test <5 pC (at 2x the operating voltage)