| 摘要 |
<p>PURPOSE:To prevent a fragment just before being exfoliated from being exfoliated and falling, as well as to prevent an electric field from being destructed by a cutting splash, outbreak of an unforeseen noise, by installing a glass protective film which covers the surface of a thick film printed resistor and a cut face of the thick-film printed resistor in a trimming part. CONSTITUTION:A glass protective film 5 is formed continuously on the surface of a thick-film printed resistor 4, cut faces 41 and the surface of a substrate 1 in such a way that it covers the surface of the thick-film printed resistor 4 and the cut faces 41 of the thick-film printed resistor 4 in a trimming part 6. The ruthenium thick-film printed resistor 4 is printed and coated between conductor patterns 2 and 3 formed on the aluminum substrate 1; it is baked; in addition, a circuit device is provided after the surface of the thick-film printed resistor 4 has been covered with the glass protective film 5. Then, this assembly is irradiated with a laser beam; the thick-film printed resistor 4 is trimmed from the upper part of the glass protective film 5; a resistance value is adjusted to a prescribed value. After completion of this trimming operation, this assembly is annealed twice for 30minutes at a temperature which is higher than the melting point of the glass protective film and lower than the melting point of the thick-film printed resistor, e.g., at about 500 deg.C; the cut faces 41 are covered with the glass protective film 5.</p> |
