| 摘要 |
PROBLEM TO BE SOLVED: To provide a thermal ink jet head in which films can be formed at a high speed and a short circuit between discrete electrodes is prevented even when defects such as pinholes occurs in an insulating layer. SOLUTION: A radiation layer 26 is formed on a narrow face of about a half of a glass substrate 25, then the insulating layer 28 is spread on the whole face of the substrate. A heating resistor 29a is disposed above a right end of the radiation layer 26. A common electrode 31b formed to the whole face above the radiation layer 26 is connected to a left end of the heating resistor 29a. The discrete electrode 31a formed onto the insulating layer 28 of a part where the radiation layer 26 is not formed is connected to a right end of the heating resistor 29a. An ink supply groove 33, an ink supply hole 34 and a diaphragm 32 are formed, an orifice plate 35 is layered, and an orifice 36 is bored. The glass substrate 25 cut as a chip is die bonded by a die bonding agent 39 to a radiation plate 37. Then, the radiation layer 26 exposed to the left end and the radiation plate 37 are thermally coupled by a heat transfer paste 41. Since the radiation layer 26 is absent immediately below the discrete electrode 31a, no short circuit takes place even if the insulating layer has the pinhole.
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