The main factors contributing to cracking Multilayer Ceramic Capacitors (MLCC) are the brittleness of the ceramic materials and the thermal and mechanical stresses associated to SMT assembly processes.
During manual rework, one of the main risks for these MLCC is the thermal shock that takes place when the soldering tip touches directly the component. When this happens, all the heat on the tip is transferred without control to the capacitor creating cracks on it.
In order to mitigate damage to MLCCs, manufacturers have been providing guidelines to reduce the risk of cracking like applying the soldering tip only to the pad so the heat is transferred to lead through the solder alloy, preheating the chip to more than 150°C to reduce the temperature gradient that takes place as soon as the soldering tip is applied, etc.
Rework components with temperature dynamic profiles
JBC Soldering introduces the final solution for reworking thermal shock sensitive components like MLCC capacitors: Temperature Dynamic Profiles for hand soldering tools.
Available for the upcoming new soldering stations range, this new functionality allows using dynamic profiles in order to control the temperature of the component during all the phases of the soldering process (preheating, soak, reflow), in accordance with IPC J-STD-001G Section 4.6, emulating the heating process in a reflow oven.
Now, by combining the new Dynamic Temperature Profile functionality with the most precise JBC rework tools, it is possible to reliably rework MLCC capacitors as small as 008004 and other thermal shock sensitive components individually eliminating the risk of disturbing nearby components.
Along with JBC Net, the first smart system to optimize traceability and resources in hand soldering, JBC soldering makes possible the rework of high-reliability PCBs for industries such as Military, Aerospace, Automotive as well as Medical.