Electronics Forum | Tue Oct 09 20:27:13 EDT 2001 | davef
That�s a 672 BALL BGA, bud!!! It�s a BIG Mutha!!! [I know. I know. For some reason suppliers call balls "pins".] Let�s focus on: * Clarifying the units on your PCB and aluminum plate thickness measurements. * Describing your use of the aluminum pl
Electronics Forum | Mon Oct 31 09:18:43 EST 2005 | jdengler
If the board is HASL you may always have trouble. Try to reduce the amount of paste by either reducing aperture size of stencil thickness. Jerry
Electronics Forum | Mon Oct 31 09:52:23 EST 2005 | slthomas
The only problems I've ever had with 208's shifting out of alignment was with a board with too much HASL thickness. The lands had a convex profile and the parts kept slipping downslope. We put down a glue dot and ranted at our board supplier. Both
Electronics Forum | Fri Apr 19 07:50:24 EDT 2002 | pjc
I used to build flash memory products for M-Systems. Up to 30,000 per week. Nothing special in the process for these boards. 1mm and 0.4mm thick std. FR4 PCBs are used. Double-Sided reflow. The 0.4mm thin boards require process carriers. Panelized 24
Electronics Forum | Tue Aug 31 20:41:45 EDT 1999 | Dreamsniper
| | I am looking for a rule of thumb regarding the maximum ramp standard components (chip capacitors) can tolerate without failure during the reflow process. The standard seems to be 3C\second, but this figure is generally derived from the average r
Electronics Forum | Wed Jun 14 08:08:56 EDT 2000 | Wolfgang Busko
Hi ji tae, we had a similar problem with QFPs 0,5 pitch processed by one subcontractor. The symptoms we noticed were: - the solderjointshape and wetting looked normal - the surface had a dull gray appearance - by pushing a lead sideways with a tweez
Electronics Forum | Sat Mar 18 02:21:31 EST 2006 | pavel_murtishev
Good morning, Once again a met annoying solder beading issue while producing board with PLL (leadless, contacts from the bottom side of the package). Board has very high placement density and beads appear near PLL package only. This package is finep
Electronics Forum | Wed Sep 22 21:12:16 EDT 1999 | se
| | | | My stencil thickness is 6 mil and we got qfp's with fine pitch. | | | | how many percent should i reduce my stencil aperture using a 6 mil stencil for 0.5 mm pitch and 0.4 mm pitch ? | | | | | | | | thanks | | | | | | | We use 6 mil lasercu
Electronics Forum | Thu Jun 28 09:07:51 EDT 2007 | mika
Laser cut 0.13mm stencil thicknes works great for us. BTW, are we talking RoHS solder paste? We do reduce the stencil apertures to 88 % of the pads when we go for the RoHS solder paste. Otherwise we go fo 96% reduction in general with some excemption
Electronics Forum | Wed Sep 22 22:23:55 EDT 1999 | SY
| | | | | My stencil thickness is 6 mil and we got qfp's with fine pitch. | | | | | how many percent should i reduce my stencil aperture using a 6 mil stencil for 0.5 mm pitch and 0.4 mm pitch ? | | | | | | | | | | thanks | | | | | | | | | We use 6
