Insufficient Solder

Defect: insufficient solder

The solder joint is incomplete resulting in an open circuit or a weak interconnection.

Process and design-related causes of insufficient solder:

• Non-coplanar leads on the component
• Excessive warpage of the PCB or substrate
• Poor wetting
• Insufficient amount of solder due to improper printing parameters
• Skips in the printed solder due to blocked stencil aperture
• Misaligned solder print
• Improper stencil thickness
• Inadequate stencil aperture size
• Excessive pad size
• Via in pad draining solder from interconnection

Reflow-related causes of  insufficient solder:

• Preheat too aggressive
• Peak reflow (liquidus) temperature not being attained
• Malfunctioning oven which is impeding attenuation of proper temperatures