| 摘要 |
A substrate (3) that has openings (3m, 3L, 3r) through which a core (2a) is inserted is provided with coil patterns (4a through 4e) on outer layers (L1, L3) and an inner layer (L2). Heat-dissipating patterns (5a7 through 5a9, 5b7 through 5b9) are provided on the bottom outer layer (L3) so as to correspond to coil patterns (4a through 4d) on the top outer layer (L1) and the inner layer (L2), and corresponding coil patterns (4a through 4d) and heat-dissipating patterns (5a7 through 5a9, 5b7 through 5b9) are connected by heat-dissipating pins (7a through 7f). The heat-dissipating patterns (5a7 through 5a9, 5b7 through 5b9) and the coil pattern (4e) on the bottom outer layer (L3) are kept separate, and the surface area of the heat-dissipating patterns (5a7, 5a8, 5b7, 5b9) connected to the coil patterns (4a, 4b) on the inner layer (L2) is made larger than the surface area of the heat-dissipating patterns (5a9, 5b9) connected to the coil patterns (4a, 4b) on the top surface layer (L1). |
