Electronics Forum | Wed Feb 23 21:24:42 EST 2000 | Dave F
Chris: Whatever way you decide to define your pads, use the same type on the component and the board. Non-solder mask defined pad advantages: � No point-of-stress concentration at edge mask and solder ball � No CTE mismatch at edge mask and solder
Electronics Forum | Tue Mar 09 20:08:08 EST 2004 | davef
Warping BGA are the usual cause of shorts in the corners and are usually caused by the reflow profile. BGA have a natural tendency to warp due to CTE and package thermal mismatch, as you have seen at rework. The PBGA will go from a bowl shape to an
Electronics Forum | Mon Mar 12 09:25:16 EDT 2007 | rgraves
Our internal designers are employing SMT connectors that utilize a �PCB positioning boss� in conjunction with normal gull wing leads. The use of these devices is based on the advertised ability of the boss to prevent �mis-insertions� and assist in �
Electronics Forum | Tue Sep 30 13:41:51 EDT 2014 | cyber_wolf
In 25 years of profiling, I have never seen a reflow profile make TOMBSTONES better. I have had "experts" come in an adjust our ovens to the "magic profile." The AOI data has never shown improvement from profile changes. EVER...EVER. As long as you
Electronics Forum | Sat Aug 19 21:06:09 EDT 2006 | mika
Hi all, At our Fuji CP-6 machines we place a lot of 0402:s, 0603:s and 0805:s chip capacitors. Our problem is that the height of the components can sometime be very extreme from different vendors. I am sure you all have experience of this phenomenon
Electronics Forum | Tue Aug 25 08:51:16 EDT 1998 | Justin Medernach
| | | Hi, | | | Does anyone has experiences in reflowing Ceramic BGA and found solder wicking ? Solder wicking has the syndrome that solder being wick from the pad and ended up in the leads. | | | We have rule out the possibility of not printing any
Electronics Forum | Sun Jun 07 06:05:37 EDT 1998 | Bob Willis
| Can anyone tell me if there is a reference for smt component height specs on the bottom side of a board, which will also go through wave soldering. A current design I am reviewing has tant caps(7343) and a crystal on the back side. Should I only b
Electronics Forum | Wed May 25 13:02:57 EDT 2005 | jsloot
I have two Samsung machines running about 500 hours a month each. Placement rate is on the average 12,000 CPH between the two. The life expectancy of the nozzles used on 1206 packages seems rather short to me. It was about 2 months ago I replaced the
Electronics Forum | Fri Sep 25 16:47:57 EDT 2009 | esoderberg
0.5mm pitch QFP's are typically mixed with large components on all of my boards. I usually use a 6 mil stencil with a minimum aperture width of 10 mils. Normal aperture size is 10 x 50 which causes shorts about 20% of the time. A recent purchase of
Electronics Forum | Sun Mar 12 13:09:33 EST 2000 | Jeff Wilson
Jeff, The problem you are describing MAY be related to the push up pin setting on your component feeder units. Please verify that the push up pin height is set correctly for the feeder units, and the nozzle pick-up and placement heights are to the c
