In the electronics industry, component reliability is crucial to ensuring the proper functioning of devices. One of the most effective methods for evaluating capacitor integrity before assembly is Confocal Scanning Acoustic Microscopy (C-SAM).
At ALTER Technology, we applied this technique systematically to detect internal anomalies that could compromise the final product’s performance. Thanks to our expertise in C-SAM, we ensure that assembled components meet the highest standards of quality and reliability.
Defect Detection with C-SAM
During a C-SCAN inspection, it is possible to identify internal defects such as voids and cracks within capacitors.
Types of Internal Anomalies Detected
These anomalies, which are not visible to the naked eye, can significantly affect the functionality and lifespan of the component. Cross-section analyses confirm the presence of these imperfections, emphasizing the importance of conducting preventive inspections with C-SAM to guarantee the reliability of electronic devices.
Relationship Between Voids, Cracks, and Delamination
In some cases, voids have been detected in capacitors without the presence of cracks, suggesting that their formation and crack development may be independent events.
Similarly, delamination and cracks can be interrelated, but they do not always occur together. A crack in the dielectric can create stress points, leading to delamination, while pre-existing delamination can weaken the structure and make it more prone to cracking. Furthermore, when a crack or delamination weakens the dielectric enough, it could cause an electrical failure due to localized material breakdown.
The following failure analysis reinforces these findings.
Failure Analysis in Ceramic Chip Capacitors
Case Study – Multilayer Ceramic Chip Capacitors
Electrical and Mechanical Effects of Defects
The study indicated that a void in the ceramic dielectric can create electrical and mechanical weak points, leading to capacitor degradation. The presence of voids reduces insulation between the electrodes, increasing the local electric field at its edges and making dielectric breakdown more likely.
Additionally, if the capacitor operates close to its voltage limit, voids can cause partial discharges that gradually erode the dielectric. Over time, this degradation can form a conductive path within the material, resulting in a short circuit between the electrodes.
Based on these observations, the most likely cause of failure was the presence of dielectric defects, which facilitated a short circuit between the electrodes. The localized current increase generated overheating, leading to ceramic rupture, which then propagated damage to the outermost layers of the component
These findings highlight the importance of conducting preventive C-SAM inspections before assembly, preventing premature failures in electronic devices.
Why Perform a C-SAM Analysis Before Assembly?
1. Prevention of Premature Failures:
Voids and cracks can weaken the capacitor structure, leading to electrical or mechanical failures in the device.
2. Quality Assurance:
3. Reduction of Repair and Warranty Costs:
Identifying and discarding defective parts before assembly prevents costly returns and rework.
4. Improved Final Product Performance:
A defect-free assembly guarantees better performance and longer durability of the device.
5. Non-destructive:
C-SAM is a non-destructive inspection method that can detect faults that weaken the material.
6. Comprehensive:
C-SAM systems can inspect materials layer by layer, providing precise and complete results for failure analysis.
7. Sensitive:
C-SAM is sensitive to interface anomalies, such as poor bonding, delamination, voids, cracks, and foreign material inclusions.
Risks of Not Performing a C-SAM Inspection
Failing to conduct a SAM analysis can result in severe consequences, such as:
- Intermittent or catastrophic failures, affect system stability.
- Internal short circuits, leading to overheating and circuit damage.
- Reduced device lifespan, increasing failure rates over time.
Conclusion
C-SAM analysis in capacitors is a key tool for the early detection of internal defects. At ALTER Technology, we have extensive expertise in applying this technique to ensure the reliability of electronic components before assembly.
Implementing this inspection as a standard practice not only improves product quality and reliability but also optimizes costs, minimizes risks, and ensures safer, more efficient devices, benefiting both manufacturers and end users.
