Electronics Forum | Mon Aug 23 14:09:56 EDT 2010 | davef
Similar to Coop's comments, above ... Bridging: * Mis-placement: misplaced components, high placement force mushrooms paste * Too much paste: HASL thickness, lead finish, poor underside support, poor underside wipe frequency, printing with too lar
Electronics Forum | Tue Feb 21 09:19:50 EST 2006 | Chunks
Hi Mark, Not to be condescending, but is your 265 camera in focus? I've seen one instance of this. If it�s not the camera, and you are sure all your other parameters are good, , then poor definition can be from bad snap-off or bad gasketing. Snap
Electronics Forum | Thu Jun 29 10:38:04 EDT 2000 | John Thorup
Hello Christopher I don't know if there is any kind of official standard but I can tell you that the HADCO DFM manual specifies a nominal thickness of 50-1500u" with an option for 100-1000u" and the Merix DFM manual specifies 30-200u" Our boards (fro
Electronics Forum | Wed Feb 07 06:37:39 EST 2007 | mk
We have been processing a family of boards for 3 years. No issues. New PCB Vendor and the boards suddenly will not print very well. Sloppy printing definition. Closer inspection reveals that the soldermask is built up .0012-.0019 over the vias, preve
Electronics Forum | Mon May 01 22:55:02 EDT 2006 | KEN
....am I reading this correctly? "Screen Printing" or "Stencil Printing" Screen = agree = off-contact.....it's fuzzy going back into the memory banks to the early 90's. Screen mesh and emulsion will stretch to produce the gasket affect while snapp
Electronics Forum | Tue Jun 13 21:57:01 EDT 2000 | Dave F
Todd: You say: "... solder masking between the lands of fine pitch components can cause stenciling problems and or manufacturing problems." I say: Fine pitch components without solder masking between the lands can cause stenciling problems and o
Electronics Forum | Wed Feb 07 07:36:11 EST 2007 | jax
mk, Should I read into the fact that you posted this on a sipad website? You could always add an etch process to you stencil design to gasket around the raised mask locations. It is currently done when additive etch's/trace's are used. The extra $20
Electronics Forum | Wed Mar 15 20:28:17 EST 2000 | Dave F
Armin: Locating vias within the courtyard of components is bad practice. Concerns are: * Poor solder paste print quality, caused by the via preventing good stencil gasketing. * Poor component reflow, caused by the via holding the component out o
Electronics Forum | Tue May 09 22:57:58 EDT 2006 | davef
The NexLev connector is built in a stripline construction, providing a continuous ground plane for each signal contact. The connectors come as tenrow connectors with 100, 200, or 300 positions at possible stacking heights from 10 mm to 30 mm. Technic
Electronics Forum | Fri Nov 05 13:58:23 EDT 2010 | chartrain
I agree that the tines (webs between apertures) can become damaged on fine pitch stencils from a blast of air. If they get bent, the stencil won't seat and gasket properly allowing bleed out of paste. Of course we all know that the air being blasted
