| 摘要 |
PROBLEM TO BE SOLVED: To prevent a solder wetted layer from being separated from an electrode layer by a thermal stress. SOLUTION: This thermal head consists of a glazed layer 2 formed on the upper face of a ceramic substrate 1, a resistor and an electrode layer 4 formed on the glazed layer 2, and further, the terminal electrode A of a flip chip-type driver LC 6 soldered together with the upper face of the electrode layer 5 through the solder wetted layer 5. In addition, a vitreous material layer 8 with a surface roughness of 0.3-1.5μm estimated in terms of a center line average roughness Ra is interposed in an area right under the soldered part between the electrode layer 4 and the terminal electrode A.
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