Electronics Forum | Thu Apr 11 04:03:28 EDT 2002 | mwoodall
The Alpha metals Hi Check 500 is used to measure paste deposit thickness. The paste height is found from a micrometer reading determined by focussing a beam of light on a track adjacent to a paste deposit and then onto the solder paste. I've measure
Electronics Forum | Wed Apr 10 13:20:36 EDT 2002 | barryg
I am curious how you measure your printed paste thickness. We are considering doing the same. As it is now we assure we have squeegee pressure and speed controlled, have not actually measure the printed paste thickness.
Electronics Forum | Wed Apr 10 11:45:08 EDT 2002 | mwoodall
We measure the thickness of solder paste printed onto PCBs as a control of the printing process. Generally 6 thou stencils are used and give between 6.2 and 6.8 thou. What thicknesses do other users get? Cheers! Mark
Electronics Forum | Wed Apr 10 22:35:59 EDT 2002 | davef
How do you assure you "have squeegee pressure and speed controlled"? Search the fine SMTnet Archives for background on measuring paste thickness.
Electronics Forum | Wed Apr 10 22:46:04 EDT 2002 | davef
On SMTnet, we've discussed the the frailties of controlling paste height, when volume is a more telling measure. Sometimes if you seperate too quickly, the paste tries to stay attached to the aperture walls. This creates a 'U' shaped deposit with r
Electronics Forum | Thu Apr 11 10:14:05 EDT 2002 | BTaylor
We use the ASC vision master 212, our customers wanted a height and volume measurement rather than an inspector doing a visual. We have added this machine to our process, checking height on many preprogrammed locations then this generates a X bar and
Electronics Forum | Mon Aug 30 16:07:06 EDT 2004 | Shean Dalton
Hi Chen, Based on your posted message, the following ideas are for your consideration: "brown residue" The water soluble solder paste you are using could be a water soluble rosin solder paste formulation. Perhaps the solder paste may not be proper
Electronics Forum | Wed Mar 21 18:32:45 EST 2001 | Steve
The design engineers I work with are blaming some circuit problems on what they think might be related to the no-clean flux residue. (It couldn't be the design.) Has any body else seen noise issues in high speed circuits related to no-clean flux resi
Electronics Forum | Fri Apr 04 14:54:19 EDT 2008 | alexs
Thanks for the reply. Just one more question. If there is less solvent but the residues are harder to clean. would there be more contaminant left on the boards? Has anyone did a cleanliness test?
Electronics Forum | Thu Apr 03 22:56:48 EDT 2008 | davef
Potential impacts of using expired solder paste are [University of Bolton]: * Changed paste rheology. Result: poor print quality * Loss of solvents. Result: reduced flux activity * Changed flux formulation. Result: More difficult to clean flux residu
