From the aspect of appearance
If it is a qualified SMD capacitor, then the appearance size should be the same as the marked size or the size marked on the manual and the outer packaging, but if you get a SMD capacitor, you find that the appearance size has changed, for example, there are slight flaws or slight cracks, then there may be some problems with the size of the appearance. The introduction shows that there is a problem with the capacitor. Secondly, look at the tin feet. If the tin feet have black spots, defects, cracks, and the unbalanced ratio between the top and bottom of the tin feet, it means that the quality is also problematic.
The quality of chip capacitors can also be judged by color. If it is a normal factory capacitor, the appearance and color are uniforms, and the same batch will not appear black, gray and other chromatic aberrations, but if you get a chip capacitor, the naked eye shows that the color on the outside has turned black, just like smoke If the smoked color is the same, it means that there is a problem with this capacitor, and this capacitor should be tested.
Another way to judge the quality of the patch capacitor is to use a digital bridge to detect it.
This is the most common method of judgment. In fact, the detection process is also very simple, directly adjust the electric bridge to the corresponding gear, and then use the bridge clamp, the capacitors of the two tin pins are in a short-circuit state. Then look at the reading at this time and stabilize the reading. If the capacitance value of the reading higher than the capacitance specification is consistent, or the deviation is within the normal error range, then the capacitance should be good.
When we buy capacitors, we should find a regular capacitor manufacturer, because the regular capacitor manufacturer will strictly inspect each product when producing capacitor products to ensure that the quality of these capacitors is qualified. Good outer packaging handling, so it can be well protected during transportation and will not be damaged due to bumps.