Patent ID: 8217271
Filing Date: 2012-07-10
Classification: H05K,Y10T

Abstract:
1. A multilayered wiring board comprising n wiring layers including wiring and a first insulating resin, and (n−1) resin base material layers including fiber bundles impregnated with a second insulating resin, where n is an integral number of 4 or more, the n wiring layers and the (n−1) resin base material layers being alternately laminated, wherein: at least one of the (n−1) resin base material layers is an adjustment layer with fiber bundles different in a crossing point density from those of other resin base material layer or layers of the (n−1) resin base material layers, the crossing point density is a number of crossing points between warp and well threads per unit area, the fiber bundles of the (n−1) resin base material layers including the adjustment layer include a woven fabric in a twill weave, a satin weave or a plain weave the n wiring layers are stacked so that a first wiring layer to a n-th 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 n-th wiring layer is adjacent to the (n−1)-th resin base material layer, and the adjustment layer is arranged so as to reduce an amount of warpage during heating as calculated based on a difference in a copper remaining ratio between each of the n wiring layers.