Ceramic Capacitors FAQQWhat details must be considered when performing reflow soldering of chip multilayer ceramic capacitors?

1. When heat is applied suddenly to a capacitor, distortion will occur due to the large internal temperature difference, causing cracking or deterioration of the substrate bendability.
   In order to reduce damage to the capacitor, be sure to preheat the capacitor and the mounting substrate.
   Also, set the preheating conditions so the temperature difference ΔT between the solder temperature and the capacitor surface temperature is within the range shown in Table 1.
   As the ΔT becomes smaller, the effect on the capacitor will also diminish.
   This also prevents tombstoning and misplacement of chips.


2. In the case of external electrode tin (Sn) plated products, when the soldering is performed at a temperature lower than the melting point of the tin, the solder wettability to the external electrodes will deteriorate and may cause defective soldering. Be sure to implement a mounting evaluation, to confirm solderability.


3. When immersing into a cleaning fluid immediately after soldering, the same as for the difference in the preheating temperature, provide an air cooling process so that the difference in the cooling temperature satisfies the ΔT in Table 1.

1. Excessive solder thickness will cause the chip to become more susceptible to mechanical and thermal stress from the substrate, and may cause the chip to crack.
2. Insufficient solder could cause the fixing force of the exterior electrode to become weak and may cause separation of the chip.
3. Confirm that the solder is applied smoothly to the end of the chip, to a height of 0.2mm or more.*

<Reference FAQ>
What is the allowable number of times and length of time for the soldering of chip multilayer ceramic capacitors?