Why tantalum capacitors explode?

Tantalum capacitors can burn or catch fire due to different reasons such as overvoltage, overcurrent, overheating or damage caused by improper handling during installation.

When a tantalum capacitor is subjected to overvoltage or overcurrent, it experiences internal heating and eventually reaches a temperature that can cause ignition of the organic materials in the capacitor. This can result in the release of flammable gases, and when ignited, the capacitor can burn or even explode.

Overheating of the capacitor due to high ambient temperatures or inadequate thermal dissipation can also be a cause of failure. In addition, damage during handling and installation can lead to a mechanical short circuit within the capacitor, which can trigger overheating and result in burning.

To prevent capacitor failure, it's essential to follow the recommended soldering profile and operating conditions, pls check the guidelines https://www.hongdacap.com.hk/pdf/Application_Guidelines_for_Tantalum_Capacitors.pdf, avoid exceeding the maximum voltage and current ratings, use appropriate cooling methods.

When engineers choose tantalum capacitors, they should pay attention on below points:

1) Products selection:

When engineers choose a tantalum capacitors, they should considering capacitance value, capacitors voltage, leakage and ESR value, and cost.

New technology polymer tantalum capacitors are safer, which can achieve lower ESR, while leakage is higher.

Standard tantalum capacitors have lower leakage compare with Polymer tantalum capacitors which is more suitable for power meter, gas meter, water meter such products.

2) Tantalum Capacitors Derating

Derating is very important facts when choosing tantalum capacitors.

According to AVX Tantalum Capacitors User Guide, pls find the guidelines

https://www.hongdacap.com.hk/pdf/Technical_Summary_and_Application_Guidelines_for_Tantalum_Capacitors.pdf, derating for tantalum capacitors are at least 50%.

Derating percentage varies depends on different circuit.

3) Tantalum Capacitors Soldering Profile

Precautions for reflow soldering:

The recommended reflow oven temperature setting for lead-free soldering is shown in the table below.

In a word, if engineer choose a reliable manufacturer of tantalum capacitors, select the proper products, install and soldering properly, tantalum capacitors is still good capacitors for some high end products.