MEASUREMENT CUPON FOR MULTI-LAYER ADJUSTMENT DEGREE OF BUILD-UP PCB

摘要

According to the present invention, ring-shaped circular circuits are formed on the upper and the lower sides of an insulation layer at the center of a build-up substrate in order to quickly check with the naked eye the interlayer adjustment degree of the build-up substrate through a coupon. An adjustment hole is vertically formed through the insulation layer which is at the center of the circular circuit.