Solution42

Defect : Insufficient solder

Process/machine infomation :

Board type - Single sided

Solderability protection - OSP

Flux carrier - Alcohol

Preheat type - Forced Convection

Process solutions

• Conveyor speed too slow.

  a. Time over preheat too long causing flux to be burned off.

  b. Dwell time too long causing flux to be destroyed before exiting the wave.

• Topside board temp too high for flux, causing flux to burn off before board reaches waves.
• Flux not surviving forced convection preheat.

  a. Forced convection is much more effective in drying and may over dry some alcohol based fluxes.

• Flux not active enough or solids percentage too low.
• Not enough flux.
• Wave height too low on one or both waves.

Board and design solutions

• Lead to hole size ratio.
• Board/component solderability.
• Component layout, orientation.