Charlie: I'm with Wolfgang ...
The prime cause of your cracked solder joint on a surface mount part is mechanical stress.
That�s about as specific as you�re gonna get. More information would be helpful. For instance: * Talk about the distribution of the problem, including a single lot or from various lots and over components and component types on the board * Tell us about the board (ie, thickness, type, solder mask, pads coating, pad size, etc) * Describe the component(s) (ie, type, termination finish, etc) * Take us through your process steps that proceed the problem, including the reflow profile and its control * Help us with the solder and the flux you are using * Discuss the crack (ie, 45� from component pad to center of fillet, er what?)
reply »