| 摘要 |
<p>PURPOSE: To relieve warps in parts of a board by other warps generated in the vicinity, by forming a circuit pattern on the surface opposite to the surface where a circuit pattern is formed, in the part of a layer different from a layer corresponding to the part different from the part where a circuit pattern is formed, in the layer where a circuit pattern is formed. CONSTITUTION: A first circuit board 4 is made except both end portions of the upper and lower surfaces and the left end portion on a first printed wiring board 3 and. A circuit pattern 5 is formed on the whole surface of the printed board 4. A second circuit board 11 is made on both end portions of the upper and lower surfaces of a second printed wiring board 10 and the left end portion. A circuit pattern 14 is formed on the whole surface of the back of the second circuit board 11. Thereby warps generated in parts of the first and the second printed wiring boards 3, 10 can be relieved by the warps generated in the vicinity.</p> |
