Grainy or Dull Solder
Published: 09 March 2010
by Paul Lotosky
Contamination or poor heat are likely culprits.
Grainy or dull solder is defined as a rough solder surface with small, gritty projections protruding through the top, or a non-shiny surface that shows no signs of chemical attack.
- Primary process setup areas to check:
- Impurities in the solder.
- Intermetallic compounds.
- Dross mixed into the solder.
- Insufficient heat.
Other things to look for in the process:
- Solder temperature too low.
- Preheat too low.
- Early removal of board.
- Solder contaminated.
- Conveyor speed high.
- Excessive solder dross.
- Conveyor vibration.
Other things to look for with the assembly:
- Board contamination.
- Component contamination.
- Improper board handling.
- Component leads too short.
Thing to look for with the bare board:
- Board contamination.
Thing to look for with the board design:
- Board contamination. CA
Paul Lotosky is global director - customer technical support at Cookson Electronics
(cooksonelectronics.com); plotosky@cooksonelectronics.com. His column appears monthly.
