4.Capacitor Distributor Murata of SMD Chip Ceramic –,2220,1206,1210,1812
Confirm the best mounting position and direction that minimizes the stress imposed on the capacitor during flexing or bending the printed circuit board. 1-1. Choose a mounting position that minimizes the stress imposed on the chip during flexing or bending of the board. 1
2. Information before Mounting 1. Do not re-use capacitors that were removed from the equipment. 2. Confirm capacitance characteristics under actual applied voltage. 3. Confirm the mechanical stress under actual process and equipment use. 4. Confirm the rated capacitance, rated voltage and other electrical characteristics before assembly. 5. Prior to use, confirm the solderability of capacitors that were in long-term storage. 6. Prior to measuring capacitance, carry out a heat treatment for capacitors that were in long-term storage. 7. The use of Sn-Zn based solder will deteriorate the reliability of the MLCC. Please contact our sales representative or product engineers on the use of Sn-Zn based solder in advance. 8. We have also produced a DVD which shows a summary of our recommendations, regarding the precautions for mounting. Please contact our sales representative to request the DVD.
3. Maintenance of the Mounting (pick and place) Machine 1. Make sure that the following excessive forces are not applied to the capacitors. 1-1. In mounting the capacitors on the printed circuit board, any bending force against them shall be kept to a minimum to prevent them from any damage or cracking. Please take into account the following precautions and recommendations for use in your process. (1) Adjust the lowest position of the pickup nozzle so as not to bend the printed circuit board. (2) Adjust the nozzle pressure within a static load of 1N to 3N during mounting.
2. Dirt particles and dust accumulated between the suction nozzle and the cylinder inner wall prevent the nozzle from moving smoothly. This imposes greater force upon the chip during mounting, causing cracked chips. Also, the locating claw, when worn out, imposes uneven forces on the chip when positioning, causing cracked chips. The suction nozzle and the locating claw must be maintained, checked, and replaced periodically
3. To adjust the inspection tolerance for automated appearance sorting machine of mounting position, because ZRB series are easier to shift the mounting position than standard MLCC. 4. To check the overturn and reverse of chip. 5. To control mounting speed carefully, because ZRB series is heavier than standard MLCC.