Patent ID: 9655242
Date: 2017-05-16
CPC Classifications: H01L,H05K,Y02P

Claim:
1. A printed wiring board, comprising: a first resin insulating layer having a plurality of concave portions formed on a first surface of the first resin insulating layer; a first conductor layer comprising a plurality of first conductor circuits formed in the concave portions of the first resin insulating layer, respectively; a second conductor layer comprising a plurality of second conductor circuits formed on a second surface of the first resin insulating layer on an opposite side with respect to the first surface of the first resin insulating layer; a first via conductor formed in the first resin insulating layer such that the first via conductor is penetrating through the first resin insulating layer and connecting the first conductor layer and the second conductor layer; and a second resin insulating layer formed on the second surface of the first resin insulating layer such that the second resin insulating layer is covering the second conductor layer, wherein each of the first conductor circuits has an upper surface, a lower surface and two side surfaces between the upper surface and the lower surface such that the upper surface is exposed from the first surface of the first resin insulating layer and that the side surfaces and the lower surface are not roughened surfaces, each of the second conductor circuits has a top surface, a back surface and two side surfaces between the top surface and the back surface such that the side surfaces and the back surface are roughened surfaces, and the plurality of first conductor circuits includes a thinnest first conductor circuit such that the thinnest first conductor circuit has a line width L