Most printed CIRCUIT board materials are very GOOD insulators, but they are not perfect, and inadequately cleaned PCB material may be quite a poor insulator.

• 绝大多数的PCB板材都是性能优良的绝缘体，但是它们也有弱点：首先，如果PCB板（表面）不够清洁，其绝缘性能将大大降低；