Invention Grant
- Patent Title: Plated through hole void detection in printed circuit boards by detecting a pH-sensitive component
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Application No.: US14088107Application Date: 2013-11-22
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Publication No.: US09250192B2Publication Date: 2016-02-02
- Inventor: Bruce John Chamberlin , Chang-Min Chu , Gao-Bin Hu , Joseph Kuczynski , Kaspar Ka Chung Tsang
- Applicant: International Business Machines Corporation
- Applicant Address: US NY Armonk
- Assignee: International Business Machines Corporation
- Current Assignee: International Business Machines Corporation
- Current Assignee Address: US NY Armonk
- Agency: VanLeeuwen & VanLeeuwen
- Agent Grant A. Johnson
- Main IPC: B05D5/12
- IPC: B05D5/12 ; G01N21/80 ; H05K3/22 ; H05K1/02 ; H05K3/42

Abstract:
An approach is provided in which a pH-indicating compound is incorporated in a printed circuit board. The printed circuit board includes a number of layers with the pH-sensitive indicator being incorporated in one of the layers. Conductive pathways are formed from a conductive sheet laminated onto an outer surface of the printed circuit board. The printed circuit board is exposed to a pH-activating solution. Plated-through hole defects in the printed circuit board are identified by detecting a color formation at a surface location of the printed circuit board that corresponds to the plated-through hole defect. Another approach is also provided where a pH-activating compound is incorporated in one of the layers of the printed circuit board which is then exposed to a pH-indicating solution to produce the color formation that identifies the location of the plated-through hole defect.
Public/Granted literature
- US20140076478A1 Plated Through Hole Void Detection in Printed Circuit Boards by Detecting A pH-Sensitive Component Public/Granted day:2014-03-20
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