| 摘要 |
<p>PURPOSE:To form a proper shaped fillet when a chip part is connected to a land, and to adjust the quantity of the bonding agent to be printed for each of different lands in a printing screen. CONSTITUTION:Lands 3 formed on a printed wiring board P are coated with a mask 5 on which a printing holes 5a and non-printing parts 5b are formed. Cream solder 7 is printed on the lands 3 through the intermediary of the printing holes 5a. At this time, printing regions 3a corresponding to the printing holes 5a and non-printing regions 3b corresponding to the non-printing parts 5b are formed. When a chip part 2 is mounted on the lands 3, the cream solder 7, which is squeezed by the pressing force of the chip part 2, spreads on the non- printing regions 3b, and a proper-shaped solder fillet is formed when solder is fused without projecting from the lands 3. Also, by adjusting the ratio of the printing holes 5a and the non-printing part 5b, the quantity of the cream solder printed for every land 3 in the mask 5 can be adjusted.</p> |
