| 摘要 |
<p>PURPOSE:To easily form many microscopic solder bumps in small number of steps in a short period of time by forming a first solder paste pattern by mask- printing and pressurizing it by a flat plate while heating to melt is, and then supplementing to print a second solder paste pattern to melt to integrate it. CONSTITUTION:A metal mask 3 having approx. 100mum of thickness is placed fixedly on a circuit board 1 formed with metallized pads 2A, 2B, and solder paste 5 is fully filled in printing openings 4A, 4B, etc. of the mask 3. Then, the mask 3 is removed, and a flat plate supported in parallel at a distance of approx. 30mum to the board face is placed as a weight. Then, it is heated to approx. 230 deg.C in nitrogen, solder paste patterns 5A, 5B1, etc., are melted, and primary solder bumps 105A, 105B, etc. having flat upper faces are obtained. Thereafter, second solder paste patterns 5A1, 5B2 are formed on the tops of the bumps 105A, 105B, etc. by a similar method, heated to approx. 230 deg.C in the nitrogen, and melted at the lower parts to be integrated.</p> |
