CyberOptics SE500ULTRA, Hardware Manual

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Chapter 4 : Troubleshooting
156 SE500
ULTRA
Hardware Manual
Solder Paste Failure Causes
Failure
Mode Possible Cause Evidence
High Height
Lack of Support Board flexes while pressed on when locked in
print position
Print speed too fast Paste left on stencil behind squeegee
Print pressure too low Paste left on stencil behind squeegee
Contamination on board Localized issue, usually on one board.
Contamination under Stencil Localized issue, usually on repeated boards
Damaged Squegee blades (usually a line of high
heights from front to back) Check blades for damage
Separation speed to fast Look for dog ears on deposit
High Volume
Lack of Support Board flexes while pressed on when locked in
print position
Print speed too fast Paste left on stencil behind squeegee
Print pressure too low Paste left on stencil behind squeegee
Contamination on board Localized issue, usually on one board.
Contamination under Stencil Localized issue, usually on repeated boards
Damaged Squegee blades Check blades for damage
Bridging
Lack of Support while printing Board flexes while pressed on when locked in
print position
Contamination on board or stencil Localized issue
Print gap too large Tap on stencil with board in position, stencil
should be very close.
Print speed to slow Squeegees grab stencil and move it
Pressure too high Squeegees grab stencil and move it
Damaged Stencil Examine stencil
Registration
Stencil alignment Look for pattern of registration issue
Screen printer calibration Need offsets for most/all products
Bad fiducial finding Random - unexplained registration issue
Stencil worn out (excessive shift while printing) Large deviation between print directions
Poor board clamping Board shifts while clamped
Board contamination preventing paste from
sticking correctly Poorly formed solder deposits
Poor print due to too fast printing or low paste.