| 摘要 |
<p>PURPOSE: To facilitate the discovery of the failure of the connection of a printed pattern with the lead terminal of the component of an IC or the like by a method wherein coloring matters different from each other are applied on the leads adjacent to each other and the distribution of the colors of the adjacent leads is judged to indicate a defective soldering by a color change. CONSTITUTION: In the case where a lead terminal 3d is properly welded to a printed part 2d on a board 1 with a solder 5, the molten solder 5 colored with a coloring matter concentrates on the contact part of the terminal 3d with the pattern part 2d to solidify and the protrusion of the solder 5 is such a degree that a slight amount of the solder 5 squeezes out of the peripheral edge of the contact part. However, in the case where there is a solder bridge between IC leads adjacent to each other, the squeezed-out solder 5 flows in a lead terminal adjacent to the terminal 3d and the color of the solder 5 is turned into a color different from that of the solder 5. Accordingly, in an inspection subsequent to a mounting of an IC4 to the board 1, if the colors of the pattern part 2d, a pattern part 2c and the like are turned into a color mixing with the coloring matter, the existence of the failure of the connection of the pattern part 2d with the terminal 3d can be easily detected from the solder bridge between the adjacent IC leads.</p> |
