PURPOSE: To enhance strength of close contactness with sealing resin by forming a recessed area which opening toward outside at the surface of an insulating base material to allow a part of the sealing resin to enter this recessed area.
CONSTITUTION: A sealing resin 22 also flows into each recessed area 17 opening toward the surface of an insulating base material 13. In this case, if each recessed area 17 is formed in sufficient length and in the predetermined direction, the sealing resin 22 naturally flows into each recessed area 17 and flows along each recessed area 17. Therefore, the sealing resin 22 flows into each recessed area 17 and also flows certainly into the other portions through this recessed area 17. Upon completion of flowing, the sealing resin 22 fills each recessed area 17 as well as the surface of the insulating base material 13. Thereby, bonding to a substrate 10 for mounting electronic parts with sufficient contact area can be ensured, resulting in the bonding with sufficient strength of contactness to the substrate 10 for mounting electronic parts.
KONDO MITSUHIRO
OSHIMA KINYA
