Patent ID: 8338717
Filing Date: 2012-12-25
Classification: H01L,H05K

Abstract:
1. A circuit substrate comprising: a base including a plurality of resin layers; and conductive layers disposed on a lower and an upper surfaces of the base; wherein the resin layers include first resin layers including a filler, and a second resin layer interposed between the first resin layers and having no filler or a filler whose amount is smaller than an amount of the filler in the first resin layer and 1 volume % or less, wherein the first resin layer includes a base material and a resin portion, the base material is made of fibers, the resin portion includes a filler, and the resin portion of the first resin layer is interposed between the base material and the second resin layer, and wherein the second resin layer includes a first concave portion and a first convex portion on an upper surface thereof and a second concave portion and a second convex portion on a lower surface thereof, the first concave portion corresponds to the second convex portion, and the first convex portion corresponds to the second concave portion.