Electronics Forum | Mon Jun 01 17:41:20 EDT 2009 | gregoryyork
What is your squeegee pressure and size. Also does the pad sit on a ground plane, as it looks like it is partially reflowed so surface has gone but not coallesced properly which would indicate it is more a problem with reflow above 217-219C OR obviou
Electronics Forum | Fri Jul 27 12:13:57 EDT 2007 | jdumont
We have issues with these also. They need to be flat to solder well. Reduce the square under the part for the heat sink and youll improve yields. That pad keeps the part lifted high while the other smaller joints reflow and partially attach. You can
Electronics Forum | Wed May 29 08:43:12 EDT 2002 | zanolli
Various solder metal supplies sell pre-forms as loose individual shapes, usually donuts. The loose performs then are placed on the connector leads. If you have any volume at all, you would want to look at a �shake table� that would vibrate a batch of
Electronics Forum | Wed Sep 07 10:41:24 EDT 2005 | D.B. Cooper
We've seen the same thing - leads of QFPs not as strong as we'd like them to be. In the past 4 years no problem, this Spring they start failing. Touch a solder iron to it and it solders fine. After crunching some data, we found that both QFPs fail
Electronics Forum | Thu Jul 12 10:32:59 EDT 2001 | Hussman
Wow, what a string of answers and nobody brought up the easiest way to eliminate solder balls. Yes, the paste being squished under the part does reflow and work it's way out to the side during reflow. I did a 5 week study on this (when I was a bori
Electronics Forum | Thu Feb 08 09:07:22 EST 2001 | Hussman
OK, without knowing the specifics, why does everyone blame the oven? Most solder balls occur around R's and C's in almost every shop I've been to. The best place to start looking is the screen printer - not the oven. Sure the oven is the last proc
Electronics Forum | Tue Aug 31 08:10:38 EDT 1999 | Brian Conner
| I am building a board with T1/34 LED's in a 10X10 array there are 12 arrays in a panel. The LED's are body to body in the array, .1 spaced. The LEDS have been autoinserted on a Universal RAD III, so they are cut and clinched. The trouble I am havin
Electronics Forum | Thu May 13 21:45:14 EDT 1999 | ardis
I am seeing reflow around my signal pins after being subjected to a profile of 204c for 1 minute and 225c for a min of 30 seconds. Signal pins are soldered into a copper plated alum. case with SB5 and then silver plated. The pins have a hot oil tin
Electronics Forum | Mon Feb 01 16:40:45 EST 1999 | Dave Waddick
I have a product using high temperature solder to connect terminal pins to a PCB. The board is single sided copper, no plaiting. The solder is 95% tin 5 % silver. The flux is low activity rosin. The product is a subassembly. When the product is
Electronics Forum | Thu Jan 15 15:13:50 EST 1998 | justin medernach
| I have a problem! The solder on my pc boards look great comeing out | of my reflow oven. They go thrue the rest of the prossese | and at the end at the qc station it's cold or whitish or gray not shiny. | does any one have a idea on how to correct
