Failure mechanism of solder bubbles in PCB vias during high‐temperature assembly
Abstract
Purpose
Pb‐free soldering challenged printed circuit board (PCB) assembly with high temperature. The purpose of this paper is to explain the failure mechanism of printed circuit board (PCB) assembly with solder bubbles of vias to avoid the problems of via‐drilling defects and solder joint failure.
Design/methodology/approach
The failure of PCB vias with solder bubbles was investigated through cross sections and SEM microstructure inspection, TMA measurement, moisture absorption analysis and DSC measurement. The moisture absorption and CTE of FR4 laminate matched with manufacturing requirement to avoid the effects of solder bubbles. The effects of via drilling with a dull drill bit were compared to that with a new drill bit.
Findings
The moisture absorbed inside holes of via plating layers could be exposed to induce solder bubbles during Pb‐free soldering assembly and dull drill bits should be prevented during the drilling process to avoid the no‐bearing drilling effects.
Originality/value
The failure of PCB vias is not only involved in the voiding in solder joints but manufacturing processes of PCB. The paper designs an approach to analyse the properties of PCB materials and the drilling effects of vias to find out the mechanism resulting in solder bubbles of vias. The problem of drill bits should be considered to prevent the moisture absorbed in drilling vias with defects.
Keywords
Citation
Chen, Y., He, W., Zhou, G., Tao, Z., Wang, Y. and Luo, D. (2013), "Failure mechanism of solder bubbles in PCB vias during high‐temperature assembly", Circuit World, Vol. 39 No. 3, pp. 133-138. https://doi.org/10.1108/CW-02-2013-0004
Publisher
:Emerald Group Publishing Limited
Copyright © 2013, Emerald Group Publishing Limited