With the rapid development of technology level, TDK chip capacitor MLCC can now reach hundreds of layers or even thousands of layers, and each layer is millimeter-thin thickness. Therefore, a slight deformation can easily cause cracks. In addition, TDK chip capacitor MLCC under the same material, specification and pressure resistance, the higher the volume, the larger the number of stacked layers, and the thinner each layer, so it is very easy to break. Another aspect is that, with the same material, volume and pressure resistance, capacitors with small specifications require that each layer of material is thinner, causing it to be more easily broken. The damage of cracks is a potential safety hazard such as electricity leakage, and in severe cases, internal solid layer displacement short-circuit faults. And a very tedious problem of cracks is that sometimes they are relatively hidden, and it is very likely that they will not be detected when electronic products are tested at the factory. Therefore, it is extremely important to avoid cracks caused by the TDK chip capacitor MLCC.
When the TDK chip capacitor MLCC is subjected to temperature shock/shock, it is very easy to gradually cause cracks from the solder end. At this point, small-sized capacitors are relatively better than large-capacity capacitors. The basic principle is that the heat transfer of large-capacity capacitors does not reach all capacitors so quickly, so the temperature difference between the capacitors itself is large, so the expansion The large size is different, which in turn causes internal stress. This is the same reason that thick glass teacups are much more prone to cracking than thin glass teacups when poured into boiling water. In addition, in the whole process of cooling after TDK chip capacitor MLCC welding, the expansion coefficient of TDK chip capacitor MLCC and PCB is different, which causes internal stress and cracks. To prevent this problem, the reflow oven must have a good laser soldering temperature profile. If a wave soldering machine is used without a reflow oven, then such inefficiencies are greatly increased. MLCC is also a process to prevent hand soldering with an electric iron.
First of all, the processing technology and production staff must be informed of the thermal ineffectiveness of capacitors, so that their ideas and concepts attach great importance to this problem. Next, it must be welded by professional skilled workers, and it is also necessary to strictly manage the welding method. For example, a constant temperature soldering iron must be used, and the electric soldering iron must not exceed 315