| 摘要 |
PROBLEM TO BE SOLVED: To restrain a land from being striped from a printed-wiring board, in which the land is soldered by using a solder material at a high melting point exceeding 200 deg.C. SOLUTION: In the printed-wiring board, a through-hole 2 passed in its thickness direction is formed in the board 1 in which conductor circuits 5 are formed on its surfaces, the land part 4 electrically bonded to the conductor circuits 5 is formed in the opening edge part of the through-hole 2, the lead part 9 of an electronic component mounted on the board 1 is inserted into the through- hole 2, and the lead part 9 is electrically bonded to the land 4 by solder 7. The solder 7 is lead-free solder having melting point of 200 deg.C or higher. Surfaces of the conductor circuits 5 are covered with heat-resistance insulating films 6 used to prevent the solder 7 from adhering, and at least the outer circumferential part of the land 4 is covered with the films 6. |
