Electronics Forum | Tue Jan 07 23:38:08 EST 2014 | m_imtiaz
want to know the tolerance the paste height in the solder paste printing. for example if stencil thickness is 7 mil, what will the acceptance level of paste height ( upper and lower) kindly share if any guidelines or formula for the same
Electronics Forum | Fri Jan 24 08:14:24 EST 2014 | davem
m_imtiaz, Over the last 15 years or so I've found that using the stencil foil thickness +2mils/-0mils has worked very well. For example, if you have a 5mil stencil thickness your upper control limit would be 7mils and your lower control limit would
Electronics Forum | Tue Feb 22 01:38:42 EST 2005 | JSS
We r using QFPs of 0.5mm pitch and r not getting any soldering prob at the end.But some new customer insists upon the thickness check of the solder paste after printing. At present we don't hv thickness checking system.We r controlling the amount of
Electronics Forum | Mon Feb 21 02:02:54 EST 2005 | JSS
First of all THANKS for thr reply. I totally agree with u that paste dried,stencil aperture clogged like probs comes during the production but we hv a visual inspection stage (with 5X illuminated lamp)after printing process and before inserting the
Electronics Forum | Mon Mar 02 11:27:51 EST 2009 | wrongway
Check stencil is their a lot of paste still on the stencil if so that is the extra thickness maybe add more pressure. check to see if board is coming up far enough to touch the bottom of the stencil.
Electronics Forum | Fri Mar 06 12:38:34 EST 2009 | mgershenson
Is this a manual measurement machine? As already stated, knowing the height of the pad underneath the paste brick is critical to knowing the true height an/or volume of paste. Any decent automated inspection system will have a way to factor out the p
Electronics Forum | Wed Mar 04 15:26:07 EST 2009 | clampron
Hi Jorge, Take a bare board and measure over the same pad. We have had similar issues with a higher deposition than the stencil thickness. In some cases, we have found that the top of the pad was higher than the solder mask. Our inspector uses the b
Electronics Forum | Mon Feb 21 03:51:37 EST 2005 | abhirami
Solder paste thickness control is more important in SMT process. What controls do you have? I guess if everyone follows the critical control path, then there are always reduced problems. The issue is no one is perfect. Paste tends to be on the stenci
Electronics Forum | Mon May 20 16:15:48 EDT 2019 | davef
Resources are: * IPC-7525A - Stencil Design Guidelines, 3.5.2 Step-Up Stencil This type stencil is useful when it is desirable to print thicker solder paste in a small portion of the stencil. An example would be a ceramic BGA where it is necessary t
Electronics Forum | Thu Oct 02 12:22:26 EDT 2008 | JerryS
Hello Ok there is not much info here. What you have to mae sure of is several key factors. 1. Have you entered the correct stencil thickness. 2. Are you using the stencil gerber (not the paste layer) The paste layer is usually not adjusted for ap
