PCBA leakage and short-circuit failures are among the most frustrating issues for electronics manufacturers—they cause production delays, increase repair costs, and damage brand reputation, especially in industrial automation, IoT, and automotive applications. When a client reported recurring leakage and short-circuit problems in their PCBAs, our engineering team conducted a comprehensive failure analysis to identify the root cause. Through non-destructive testing and structural inspections, we uncovered a critical PCB quality defect: abnormal internal copper wire bridging to component pads. Read on to learn how we diagnosed the issue, and how partnering with a reliable PCBA manufacturer can prevent such failures.
Figure 1leakage and short-circuit faults
The client encountered unexpected leakage and short-circuit faults during PCBA operation, which disrupted their production schedule and raised concerns about product reliability. Multiple failed samples were submitted to our lab for in-depth analysis, with the goal of pinpointing the exact cause and implementing preventive measures.
2. Brief Overview of Analysis Methods
We adopted a systematic approach to rule out common failure causes, combining visual inspection, resistance testing, X-Ray imaging, and structural analysis:
Figure 2X-Ray Fluoroscopy
Figure 3Green Solder Mask Removal & Grinding
The test results conclusively ruled out poor soldering as the cause of the short-circuits. Soldering processes cannot cause copper wires under intact green solder mask to deform and bridge adjacent component pads—this points to a pre-existing PCB quality defect.
After solder mask removal, the copper wires identified via X-Ray were confirmed to be directly connected to the pads in Area A. In normal PCBs, these copper wires should run parallel between the two pads. However, in all failed PCBAs, the copper wires in this area were misaligned and unevenly bridged to the capacitor pads.
Thus, we determined the root cause of the PCBA leakage and short-circuit failures: PCB quality abnormalities, specifically abnormal internal copper wire bridging to component pads. This defect created unintended electrical pathways, leading to the observed faults.
Prevent PCBA Failures with Rigorous Quality Control
PCB quality is the foundation of reliable PCBA performance—even minor defects like copper wire misalignment can trigger critical failures. At Fumax, we prioritize end-to-end quality control to eliminate such risks for our clients. Our services include strict PCB incoming inspection, advanced X-Ray testing for internal defect detection, and comprehensive PCBA functional testing (ICT, FCT) to ensure every product meets industry standards.
As a trusted turnkey PCBA solutions provider, we specialize in serving small and medium-sized industrial, automation, and electronics companies. Our expertise covers PCB design, multi-layer PCB manufacturing, SMT assembly, BGA rework, and failure analysis—all backed by ISO9001 certification and RoHS compliance. We leverage advanced testing equipment and strict quality protocols to deliver reliable PCBAs that minimize downtime and reduce repair costs.
Don’t let PCB quality defects derail your projects. Partner with us for robust, failure-free PCBA solutions tailored to your specific application needs. Contact us today for a custom quote and quality assurance consultation.
