US 2025/0085332 A1 · SYSTEM AND METHOD FOR DETECTING DEFECTIVE BACK-DRILLS IN PRINTED CIRCUIT BOARDS

Abstract

A method for detecting failed back-drills in PCBs in the process of fabricating a PCB so that the failed back-drill can be screened out or repaired. A short to ground connection is added for every back-drill via that will be cut when the back-drill removes the via stub. If the back-drill is bad or failed the short to ground will fail the subsequent electrical tests. The PCB can be repaired by re-drilling the hole or via. Failed back-drills may be detected in the manufacturing stage using standard equipment and test procedures. This process creates a simple pass-fail measurement that uses an existing common test process to catch failed back drills in the PCB fabrication facility. This allows for easy and cost-effective repair and guarantees back-drill failures do not pass into the field.

Claims20

Dependent claims

A method for detecting a failed back-drill in a printed circuit board (PCB), the method comprising:

accessing a PCB design;
selecting a non-ground via of the PCB design;
adding a shorting trace from the non-ground via to ground in the PCB design,
wherein the non-ground via is associated with a back-drill;
accessing a PCB manufactured according to the PCB design;
electrically testing the PCB to determine if the non-ground via is shorted to ground;
and
detecting a failure in the back-drill if the non-ground via is determined to be shorted to ground.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application

18/958,656Filed 25 Nov 2024

Priority

11 Feb 2021

Published

13 Mar 2025

Term ends

Not estimatedThe source records don’t support an estimate.

Classification9 codes

G01R 31/2812
Specific types of tests or tests for a specific type of fault, e.g. thermal mapping, shorts testing: checking for open circuits or shorts, e.g.…
H05K 1/0268
Marks, test patterns or identification means: for electrical inspection or testing
G01R 31/2805
Testing of printed circuits, backplanes, motherboards, hybrid circuits or carriers for multichip packages [MCP]: bare printed circuit boards
G01R 31/70
Testing of connections, e.g. of plugs or non-disconnectable joints: testing of connections between components and printed circuit boards

System and method for detecting defective back-drills in printed circuit boards

Life of this patent

System and method for detecting defective back-drills in printed circuit boards

Life of this patent

Abstract

Claims20