| 摘要 |
PROBLEM TO BE SOLVED: To eliminate soldering failure in a through hole and prevent cracking and chipping of resin which are generated when resin attaching to a lead is removed, by making a diameter of a resin part, which remains after unnecessary resin attaching to a lead is removed, larger than a through hole of a circuit board. SOLUTION: A ceramic varistor element whereto a lead 3 of ϕ 0.8 mm is soldered is heated at 160 deg.C and is immersed in powder-like epoxy resin of melting point of 58 deg.C, and a varistor element surface is coated with epoxy resin by a fluid immersion method. The varistor element is heated again at 160 deg.C for 30 minutes and attaching epoxy resin is fused. When a resin film 4 attaching to the lead 3 does not attain a specified thickness, operations of heating, immersion in epoxy resin and re-heating of a varistor element are repeated until it attains a specified thickness. Then, a varistor element is cooled to a normal temperature, the epoxy resin film 4 is held in a semi-cured state, and an unnecessary resin film 14 is removed by jetting high water pressure. |
