| 摘要 |
PURPOSE:To produce a mold for injection molding of a liquid resin in a large scale inexpensively without damage of lead wires and leakage of a resin by covering the contact face, which supports the lead wires or lead frames, of at least one part of a mold with heat resistant high-elasticity rubber. CONSTITUTION:A mold is opened by lowering a lower mold 6, and an electronic part 21 having many lead wires 20 such as a transformer and an inductor is inserted into the cavity 16 of the mold. The lead wires 20 are mounted on a fluorine-contained rubber plate 18 of a lower side mold plate 8 arranging the wires not to overlap each other. The whole lower mold 6 is then lifted to close the mold. A liquid thermosetting resin 22 like epoxy resin is injected under relatively low pressures. The injected liquid thermosetting resin 22, through sprue, runner and gate of an upper mold 7, is charged into the cavity 16 of the mold, the temperature of which is kept about 50-150 deg.C, and then cured to form a thermosetting resin coat of an insulating seal part outside the electronic part 21. Thus, the molding process is simplified to improve the productivity. |
