| 摘要 |
PURPOSE:To combine both characteristics of mechanical strength and electrically insulating property in one body by a method wherein a U-shaped heat generating part and a lead part are constituted in one body by electrically conductive ceramic material and an electrically insulating layer placed at the periphery of the lead part is formed into a membrane with a specified thickness by an amorphous glass having a softening point of 700 deg.C or more. CONSTITUTION:A ceramic heater 11 is formed in such a manner that electrically conductive sialon powder and thermoplastic resin are kneaded together, injection- molded, and baked. A heat generating part 20 is formed in a small diameter so that its thickness is thinner than those of lead parts 21, 22 and at the center part of the heater 11 a slit 25 is formed. On the periphery of the parts 21, 22 material having an unchanged property in its quality at the baking temp. of silver solder such as amorphous glass with a softening point of 700 deg.C or more is used and electrically insulating layers 23, 24 with a thickness of 10-100mum are formed. A sheet 30 for sealing composed of rubber, asbestos, etc. is inserted into and attached to the outside edge of an assembled unit 15 for terminals which is equipped with primary and secondary connecting terminals 13, 14 for the outside and placed at the opening part in the rear part of a holder 12 and is constituted to seal this parts mechanically.
|
