ABSTRACT
PC Board materials are available in various grades, as defined by the National Electrical Manufacturers Association (NEMA). The important properties for PC Board materials are tabulated in Table 20-6. It is very important to choose the correct PC board material for your application. Planar transformers are a normally stressed to the last watt for a given temperature rise. This could give rise to hot spots at winding terminations and cause PC Board discoloration. Due to their inherit design Planar transformers will have a wide temperature delta, ∆t. It would be wise to stay away from paper/phenolic materials and materials that absorb moisture.
