| 摘要 |
An electromagnetic relay is provided which enables a coating process with a coating agent even after being mounted on a printed circuit board having undergone reflow heating by preventing invasion of water while maintaining air permeability. A main body making up the electromagnetic relay includes an electrical contact portion, electromagnetic driving portion and molded resin base and is covered with the molded resin cover. One or more through holes are formed by applying laser beam from a rear side of the molded resin cover. A spot diameter of each through hole on a surface of an outside of the molded resin cover is 0.1 mum to 10 mum. Instead of the molded resin cover, through-holes each having a size of 0.1 mum to 10 mum may be formed by applying the laser beam to the molded resin base. Moreover, a liquid crystal polymer may be used as the molded resin cover or base having a filtering function, by forming holes to pass through only skin layers making up the liquid crystal polymer by applying the laser beam to the liquid crystal polymer.
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