Electronics Forum | Fri May 21 15:50:41 EDT 1999 | John Thorup
We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendors
Electronics Forum | Mon May 24 13:33:46 EDT 1999 | Dave F
| We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendor
Electronics Forum | Sun May 23 15:12:59 EDT 1999 | JohnW
| We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendor
Electronics Forum | Thu Jun 01 21:19:52 EDT 2006 | ec
Hi Russ, Thanks for your input. Currently, our stencil is at 5 mil thickness and the paste height from 5.5 to 6.5mil. I have increase the paste height to 7 to 7.5 mil and great improve....... I just need some data to present to my management and tel
Electronics Forum | Mon Nov 13 08:24:03 EST 2000 | G. English
Richard, From your description of the IC, as Wolfgang indicates it sounds like a 20mil pitch device, the aperture design really depends upon your solder paste particle size, we use a type 3 solder paste with a mesh size of �325 / +500microns. This is
Electronics Forum | Fri Sep 21 01:31:13 EDT 2001 | Stoney Tsai
Guys, If there are any specifications or ciriterions for solder paste deposition thickness and volume evaluation. For example, QFP (0.5 mm pitch), 6~8 mils, 3000 mil^3 PLCC: 8~10 mils, ... . . Thanks in advance. Best Regards,
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 | 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 | Wed Sep 12 14:08:37 EDT 2001 | caldon
PLEASE!!!! If that were the case then a 6 mil stencil is not a 6 mil stencil depending on paste, pressure, snap off...... We have and use the LSM 300 paste inspection to great degree of success (esp. for solder paste on semiconductor devices). So w
Electronics Forum | Fri Sep 17 09:31:17 EDT 2004 | russ
Step stencils are used but only when necessary. One reason to use one would be a PCB with 12 mil pitch and very large coils or something of that nature. The 12 mil pitch part would require a 4 mil thick stencil to ensure release while it would caus
