| 摘要 |
<p>PURPOSE:To obtain a chip resistor having no biting of solder on a silver thick film electrode when a solder dipping work is conducted without electrolytic plating, also having both excellent solderability and long-term preservation by a method wherein a protective layer consisting of resin, having specific resin softening point, is provided on the surface of an exposed copper electrode. CONSTITUTION:A protective layer 6, consisting of resin having the resin softening point of 60 to 90 deg.C, is provided on the surface of an exposed copper electrode. For example, a chip resistor is formed using a 96 alumina substrate 1 as a base material, a silver thick film electrode is used as an upper surface electrode layer 2, the ruthenium thick film resistor, partially overlapping on the upper surface electrode layer, as a resistance layer 4, lead borosilicate glass of the protective layer of the resistance layer 8 as an insulative glass pattern layer 5, and a thick film electrode, which is mainly composed of copper and partially overlapping on the above-mentioned upper surface electrode 2, as an end face electrode layer 3. Aromatic resin, which has the resin softening point of 60 to 90 deg.C and melted by heating together with a flux when a soldering work is conducted, is coated on the exposed electrode surface of the chip resistor. The above-mentioned material is left as it is at the temperature of 40 deg.C for five minutes, dried up and a protective layer 6 is formed.</p> |
