Patent ID: 8344260
Filing Date: 2013-01-01
Classification: H05K,Y10T

Abstract:
1. A multilayer wiring board comprising n wiring layers including a first insulating resin and a wiring element made of a conductive material, wherein n is an integer equal to or larger than 4, and (n−1) resin base material layers including fiber bundles in fabric form having warp direction fibers and weft direction fibers impregnated with a second insulating resin, the warp direction fibers being substantially perpendicular to the weft direction fibers, the n wiring layers and the (n−1) resin base material layers being laminated in an alternately layered manner, the n wiring layers are stacked so that a first wiring layer to a nth wiring layer are stacked in this order and the (n−1) resin base material layers are stacked so that a first resin base material layer to a (n−1)th resin base material layer are stacked in this order, the first wiring layer is adjacent to the first resin base material layer and the nth wiring layer is adjacent to the (n−1)th resin base material layer, wherein each of fiber bundles of the (n−1) resin base material layers have either a first linear expansion coefficient or a second linear expansion coefficient, the second linear expansion coefficient being different from the first linear expansion coefficient, all the fiber bundles of one of the weft direction fibers or the warp direction fibers in at least one specific (n−1) resin base material layer of the (n−1) resin base material layers have the first expansion coefficient and all the fiber bundles in the same direction in others of the (n−1) resin base material layers have the second linear expansion coefficient, and all the fiber bundles of another of the weft direction fibers or the warp direction fibers in all of the (n−1) resin base material layers have the second linear expansion coefficient.