| 摘要 |
PURPOSE:To uniform the distribution of charges surely and to increase the protection of electret material remarkably, by bonding a dielectric substance to the electret material of an electret element with adhesives. CONSTITUTION:An electret material 22 made of macropolymer film such as PP, TFE, FEP is coated on a back electrode 21 made of a conductive metal base to form an electret 23. A dielectric substance made of a conductive metal material or an organic substance having equal or less area shape as the member is bonded to the circumference of the member 22 with adhesives 20. Although the nonelectret part is in existing to the electret member 22, charges almost the same charges of the electret element 23 uniformly distributed on the surface of the dielectric substance 24. Thus, products rich in the moisture-proof and stable in the characteristics can be manufactured. |
