Electronics Forum | Thu Jul 20 17:01:26 EDT 2000 | Bob Willis
Here is some further information on SDSRS process, but please purchase a copy of the report from t he SMTA as all the money goes to charity. In the UK the SMART Group raised over �3000 for the homeless. SMTA have been raising a lot of money for the G
Electronics Forum | Sat Dec 01 09:09:24 EST 2001 | davef
Sounds like a perfect place to start. Sure we all have different perceptions of fun, don't we? Trial by fire, eh? ;-) A prediction: Your cost accountants are going to freak when they compare the production costs for this board to the more famili
Electronics Forum | Thu Aug 13 10:58:58 EDT 2009 | davef
First piece of advice: build the board as you would any other board. Probably, you will be surprised at the holding force of the solder of the connections of the BGA, because the surface area of the solder is very large compared to the weight of the
Electronics Forum | Thu Jun 23 10:43:40 EDT 2005 | davef
It wouldn't surprise us [too much] if this part wouldn't stay for second sided reflow. * If the lead contact area to weight is less than 44 gm / inch^2 [we know the units are goofy, but convient], it'll stay. * Alternately, just run a scrap board a
Electronics Forum | Thu Nov 18 19:45:26 EST 1999 | Deon Nungaray
Deon Response: Hello Will, Yes, you can reflow a double sided board using 63/37 solder paste on both sides. There are some limitations as far as the mass of the components to reflow the second time. If you have doubts or are concerned that a compone
Electronics Forum | Thu Nov 18 09:34:58 EST 1999 | Wolfgang Busko
Hi Will, it�s possible to use second reflow for second side components without glueing or use of different alloy solders. Although the first soldered joints become liquid during the second pass the parts will not fall off as long as their weight does
Electronics Forum | Fri May 24 09:34:57 EDT 2013 | markhoch
I run the same profiles for Top and Bottomside assemblies for all of my products. Only in rare instances have I been forced to run a profile with cooler bottom zone settings. This was obviously driven by assemblies with heavier components on the bott
Electronics Forum | Fri May 24 19:18:03 EDT 2013 | hegemon
The formula is a great help, where was it 20 years ago? LOL After running a few thousand different products over the years, you start to get a feel for what is going to be trouble with regards to falling off the bottomside during the secondary refl
Electronics Forum | Fri Mar 02 09:08:25 EST 2007 | samir
There is a formula that determines whether a component will fall off during a 2nd reflow. It takes into account the grams (weight) of the component and the total surface area of the solder joints. I don't know this off the top of my head, but it's
Electronics Forum | Mon Aug 19 20:45:31 EDT 2002 | davef
Bob Willis and Phil Zarrow have had a running commentary on the ability of reflowed solder to hold components on the bottom side during reflow. You can find references to their component weight to pad area rations in the fine SMTnet Archives. The
