| 摘要 |
PROBLEM TO BE SOLVED: To obtain a circuit board without warpages, even if it is affected by heat in a reflow furnace or the like by setting the scattering of the amount of a conductive member in the direction of the plate thickness with a center in the direction of the plate thickness of the wiring board as a reference to a specific range in a conductive layer. SOLUTION: For conductive pattern of a copper foil layer L1, its function is patterned based on an electrical circuit, thus forming five line refracted patterns. A copper foil layer L6 is patterned similarly to form three straight lines and two area patterns. Then, the copper foil layer L1 is subjected to balance treatment, an area increase pattern 4 of the copper foil is provided at a right half portion of the substrate as the copper foil layer L1, and the area ratio on the substrate surface of an entire copper foil pattern is increased to 60%. However, the copper foil layer L6 is also subjected to balance treatment, and an area-reducing hole 5 is opened at the left half area portion of the substrate for reducing the area to form the copper foil layer L6, thus causing the area ratio on the substrate surface of the total copper foil pattern to be reduced to 63%. |
