| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of a solder bridge even if a four-way flat package IC is mounted on a printed wiring board and this printed wiring board is soldered by solder dip method. SOLUTION: A frontward soldering land group 3 and a rearward soldering land group 4 are made, corresponding to each lead 2a and 2a' of a flat package IC2. Sideward solder drawing lands 5 and 6 are made between the frontward soldering land groups 3 and 3 and the rearward soldering land groups 4 and 4, and a lead 2a which serves as a tail in the direction of the progress of the above soldering of the frontward lead group of the flat package IC2 is arranged, and also the flow S of solder is drawn from the frontward solder land groups 3 and 3 to the rearward soldering land groups 4 and 4. First rearward solder drawing lands 7 and 8 are made between several rearward soldering land group 4 and 4, and a lead 2a' which serves as a tail in the direction of the progress of the above soldering of the rearward lead group of the flat package IC2 is arranged, and the flow S of solder is drawn rearward in the direction of the progress of the above soldering from each rearward soldering land groups 4 and 4.
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