2004 年 7 巻 7 号 p. 635-638
We observed the space charge behaviour and internal electric field distributions of various insulating materials used in printed circuit boards, and found that internal charges move in aramid/epoxy specimens under a do electric field. The electric field near the surface of the specimen, therefore, was increased to more than twice the strength of the average applied field. The space charge profile was strongly influenced by the internal structure. Since the space charge profile affects the internal electric field distribution, the internal charge behaviour should be examined with respect to the design of the insulation of a printed circuit board.