PURPOSE: To make the polarity identification of small electronic part secure and easy by a method wherein two surfaces of a die are hardened in different status while the status of two surfaces of exterior resin part are also differentiated.
CONSTITUTION: One surfaces 31 of a die forming an exterior resin part 1 is patterned after a lattice form, etc. which the other surface 32 is left blank as it is and then both surfaces are molded out of resin to seal lead pins 21 and 22 with element. The surface and backside of a product thus molded may be identified by the lattice form on the outer face resin part 1 and the blank surface on the backside to specify the location of lead pins 21, 22 identifying the polarity. In order to make directions aligned by optical means such as automatic discriminator, the optical and automatic discrimination may be facilitated by changeable reflection coefficient due to mirror outer face and rough backside.
SADAMASA SOUICHIROU
KURODA TOSHIAKI
YOSHIKAWA TAKAYUKI
