Electronics Forum | Fri Mar 14 04:42:24 EST 2003 | emeto
Hi, About Thombstone defects: 1.Placement accuracy-main reason 2.Soldering-should be right on pads.The print should have regular shape.The quontity of the solder on both pads on one component have to be equal. 3.Reflow: the profile have to be made v
Electronics Forum | Mon Nov 06 14:00:45 EST 2006 | nodlac
Checks calendar ...nope not April 1st. -The fresher the paste the better the solder joint. Agreed - My dilema here is upper management wants the two lines to share one stencil printer thus saving the cost of purchasing a second printer. They propos
Electronics Forum | Wed Nov 18 10:39:48 EST 1998 | Scott Lolmaugh
| | | Does sombbody know what DPM rate a good and reliable SMT assembly line (incl. solder paste print, assembly and feflow soldering) has? | | | | | Chris, | | It may be helpful if you could translate DPM into a meaningful phrase as many people (my
Electronics Forum | Tue Aug 28 13:46:46 EDT 2001 | mparker
To clarify on "Opportunities"- With 1000 components, the opportunities are far greater than 1000. You have 1 opportunity per component for a component defect i.e. bent lead, damaged part, tested bad, etc. You have a second opportunity per component
Electronics Forum | Wed Mar 16 09:06:07 EST 2005 | russ
This is what I might do, I would purchase either a solder volume (preferred) or at the least a paste height measurement piece of equipmment, The most important parameters with pronting are volume and registration. You need one of these inspection
Electronics Forum | Wed Dec 08 11:26:04 EST 2010 | davef
3 Printer Area Conditions * As stated earlier, heat and humidity are damaging to solder paste. Ideally, the printing area should be maintained at 40% - 50% relative humidity and 72°- 80°F (22-26°C). In addition, no air (cool or warm) should blow dire
Electronics Forum | Tue Jan 23 10:22:27 EST 2007 | Peter W.
Hello, maybe you are experiencing the so called "head in pillow" defect. It is especially critical for larger BGA. The defect comes from the deformation during reflow of the BGA, so that some of the balls are lifted and have no contact during liquid
Electronics Forum | Fri Jan 04 07:54:24 EST 2008 | benzy1961
My experience has been very different from the other responders. We put an in-line system in place about 3 months ago and the results have been pretty eye-opening. We were astounded to see how many prints were actually bad once we started inspectin
Electronics Forum | Mon Nov 12 09:37:17 EST 2007 | russ
You need to perform process a capability study prior to putting these controls into place. Cleaning a stencil after each pass will get ugly, solvent residues remaining in apertures etc. 2D inspection is good. Change paste every hour will get very
Electronics Forum | Thu Mar 29 12:05:38 EDT 2007 | cecil
OK, just finished our prototype build. PWB 7.5" x 10" 16 layers smallest pitch 17mil smallest BGA pitch 30mil (round apertures) smallest component 0402 total of 1492 placements 5 mil stencil foil (invar) Had numerous PQFN packages that always gave
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