| 摘要 |
PROBLEM TO BE SOLVED: To reduce the diameter of a conducting part which connects coil patterns of the surface and the back and increase mechanical strength, in a thick-film printed coil for a motor. SOLUTION: A laminated plate, wherein copper foils 2 are stuck on both surfaces of an insulating board 1, is used. A through-hole 3 is formed at a necessary place, and a plating layer 4 is formed previously on an inner wall. After coil conductor patterns are formed on the surface and the back of the board by etching, the through-hole 3 is filled with resin 8. Electrolytic plating is performed for enlarging the sectional areas of the conductor patterns. By this plating, large electrolytic plating patterns 7 are formed on the conductor patterns 6 in the direction of thickness. Since a through-hole which connects the conductor coil patterns of the surface and the back is filled with resin, tensile stress (at heating) or compressive stress (at cooling) which are applied to the conductor by the difference of expansion coefficients from the insulating board is dispersed to the whole upper surface and the lower surface and will not concentrate in a specified position, so that the disconnection due to thermd cycle fatigue can be reduced drastically.
|
