Patent ID: 6657135
Filing Date: 2003-12-02
Classification: H05K

Abstract:
A connection structure comprising:a board having a front surface and a back surface with a through hole formed to penetrate through the board; a land including a wall surface land portion formed on a wall surface of the through hole, a front surface land portion formed on the front surface of the board around the through hole and a back surface land portion formed on the back surface of the board around the through hole; a lead extending from an electronic component and disposed so as to penetrate the through hole from the front surface to the back surface of the board; and a fillet made of a solder material by flow soldering so as to connect the land and the lead, the fillet including an upper fillet portion located on the front surface of the board and a lower fillet portion located on the back surface of the board, wherein a profile of the upper fillet portion contacting with the front surface land portion is smaller than a profile of the lower fillet portion contacting with the back surface land portion, and is not smaller than a profile of the through hole.