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Component damage is a problem often faced during assembly caused by mechanical force, temperature shock or twisting and tension forces.

When checking for possible causes of failure, make sure the full production cycle is checked. Component failure may be nothing to do with assembly operations, as is illustrated in the Figure 1, which shows components found to be damaged when they were received.

Figure 1: Capacitors that arrived cracked.

Component cracking is normally due to the incorrect use or specification of the component. Initially check the suppliers maximum soldering temperature and duration. Also consider any other special requirements for component storage. The most common cause, as in the case of Figure 2, is excess heat. If the component supplier specifies the maximum temperature for reflow of <220oC or 240oC for wave solder the component should not have been designed into the product. A poor design for manufacture practice. Components can be assessed against the IPC or IEC process compatibility specifications.

Component compatibility testing should always be done on suppliers parts prior to approval or for new suppliers.

Figure 2: This component was cracked by excess heat.

Component compatibility testing should always be done on suppliers parts prior to approval or for new suppliers.

Cracked chip components found after reflow soldering are not that likely to be caused by reflow. They are more likely to be caused by component placement or result through poor handling after reflow. If older assembly equipment is being used, the placement tweezering and placement force may be causing the initial fracture, which appears as a crack after the soldering operation. Incorrect component specification during design will also contribute to early failure.

The most common fault is caused by flexure of the board after the soldering operation. If multiple panels are being used, examine the break-out stage. Suck-down onto an in-circuit test fixture can also cause component cracking.

Figure 3: This capacitor was cracked during assembly.

Cracking has been seen recently on components passing through reflow ovens with poorly adjusted centre board support, which can damage components on second side reflow. Support fixturing for screen printing and component placement of the second side assembly should also be reviewed.

Figure 4: A cracked chip component.

Large plastic components like the QFP in Figure 5 are prone to cracking during wave and reflow soldering. This is caused by moisture in the component expanding during the high temperature of the soldering operation. The cracking is either seen on the top of the device, which fairly obvious, as in the example, or on the base of the device, which is not so easy to detect.

Check the component specification of the part and the required storage conditions. Many of the QFP and TSOP devices require storage in special low humidity environments to prevent moisture absorption.

Figure 5: A cracked chip component.

Chip Leaching	Component Cracking	Cracked Joint	Crystallized Joints	Failure to Reflow
Joint Failure	Joint Voiding	Lifted Component	Open Joints	PCB Measelling
Plastic Coplanarity	Plastic Softening	Poor Pad Wetting	Poor Solderability & Wetting	Solder Beading
Solder Short	Solder Wicking