Patent ID: 9560774
Date: 2017-01-31
CPC Classifications: H05K,Y10T

Claim:
1. A method for manufacturing a circuit board, comprising: providing a panel including a first major surface, a second major surface opposite the panel from the first major surface, and a first conductive layer that includes a first signaling trace having a first pad and that is located between the first major surface and second major surface; drilling and plating the panel to provide a plated hole that extends from the first major surface to the second major surface and through the first pad of the first signaling trace; back-drilling the plated hole from the first major surface of the panel such that a first portion of the plated hole is removed to provide a first remaining portion of the plated hole having a plated hole diameter and a first transition from the first remaining portion of the plated hole to a first portion of an unplated hole that includes a first unplated hole diameter that is larger than the plated hole diameter; and back-drilling the first portion of the unplated hole from the first major surface of the panel to provide a second transition from the first portion of the unplated hole to a second portion of the unplated hole that includes a second unplated hole diameter that is larger than the first unplated hole diameter.