Electronics Forum | Mon Oct 29 11:39:09 EST 2001 | Stefan Witte
If you are doing this in a high volume, you could concider using a pin transfer method. Apply solder paste first. Have a plate made with retractable pins in the location you want to have the adhesive dots. Dip the pins into a lake of adhesive. Align
Electronics Forum | Fri Jul 28 09:12:59 EDT 2006 | pavel_murtishev
Good afternoon, Profile is standard ramp-soak-spike (According to paste manufacturer requirements), paste is Almit V16L HM1-RMA, type 3, Sn62Ag2. Look here for details: http://www.yousendit.com/transfer.php?action=download&ufid=98684D1201B0F001
Electronics Forum | Mon Nov 17 14:42:02 EST 2014 | tombstonesmt
Sounds like your snap off profile needs adjustment. More than likely there is paste under the stencil being transferred over to the board. Try adding a cleaning cycle after every board to determine if this is the issue. If the solder balls go away af
Electronics Forum | Fri Apr 02 22:01:19 EST 1999 | Dean
| Anyone knows what is the optimum squeegee angle for screen printers. | | 45 Degrees. The forward velocity creates a downward pressure equal to the vector pressure (equalibrium). This is commonly known as paste "rolling action". Too obtuse an an
Electronics Forum | Mon Dec 13 05:43:27 EST 1999 | Wolfgang Busko
Hi Steve, 20 mil pitch shouldn�t be that problem nowadays. In your case bridging and poor wetting seem to go hand in hand. For the poor wetting try to eliminate it by using different paste (higher activated) and work on your profile. Coplanarity also
Electronics Forum | Wed Jul 09 11:58:03 EDT 2003 | sam
When we try another test by using less solder paste, we found under the microscope that the solder was actually stick on the LED gold surface, but not having good wetting. By this finding, we can basically conclude that it was poor solderability caus
Electronics Forum | Tue Dec 13 08:08:54 EST 2005 | Amol Kane
Grant, Have you looked at the microstructure of your lead-free BGAs soldered with leaded paste? how do they look?? the reliability of LF BGAs with leaded solder is extremely poor.
Electronics Forum | Mon Jan 09 07:56:49 EST 2006 | slthomas
Squeegee pressure or height, snap off, the age and/or condition of the paste and the condition/cleanliness of the stencil are about all I can come up with, unless you got a new stencil and you changed the design parameters or they made it wrong.
Electronics Forum | Tue Oct 31 13:31:36 EST 2006 | John S.
We've just started running a lot of double sided assemblies. What is the preferred method for removing paste from a board that is populated on side 1 if the side 2 print is poor? Thanks John S.
Electronics Forum | Mon Oct 12 14:30:58 EDT 2015 | duchoang
Hello Eniac, 1/- Insufficient solder paste, check your print (Printer/Stencil). 2/- If you've got good paste deposit, that could be contaminated pads causing poor solderability. Good luck.
