| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve the problem that a mounting substrate is formed from an even number of layers in accordance with a manufacturing method because of convenience for an element to be packaged although conductive patterns in an odd number of layers are enough, if the mounting substrate is formed from conductive patterns in an odd number of layers, the mounting substrate cannot be vertically balanced around a core layer and the mounting substrate may be warped.SOLUTION: In an explanation for a mounting substrate of nine layers, among three lower insulating layers L1-L3, the bottom insulating layer L3 is formed thicker than the other insulating layers L1, L2, U1-U4 excluding a core layer C. Among through holes of the lower layers, a through hole THL of the bottom layer is made larger and than diameters of the other through holes of the lower layers or upper layers and deeper. Therefore, warping caused by an insulating layer U4 which is formed excessively is compensated by the thick insulating layer L3. At the side of an IC 52, since the number of terminals may be increased more, an electrode per se and a solder ball B2 per se to be mounted are made small but flatness of the mounting substrate per se is improved, such that a mounting property is improved.</p> |
