Electronics Forum | Wed May 15 12:55:11 EDT 2002 | fmonette
Hi Dave, The short answer is "not any significant amount" of moisture is removed during reflow. The temperature excursion is much too short. If you look at the physics of moisture diffusion inside a package you will see that only the surface moist
Electronics Forum | Mon Feb 03 18:00:49 EST 2003 | slthomas
I know that the accepted (by some, although some say it may be too conservative) rule is anything less than or equal to 30 grams/square inch of surface contact area should stay on the bottom side during the second pass. How is that surface area meas
Electronics Forum | Mon Aug 13 05:56:39 EDT 2007 | chrispy1963
This may sound silly to ask, but does your oven have a center board support by chance? If so is it down when running the boards through the oven? I only ask this because we had the solenoid that operates that function (raise and lower) of the board
Electronics Forum | Thu Jun 22 11:01:54 EDT 2000 | Chrys Shea
Jason, Double sided reflow should be no problem. People have been doing it for years. The surface tension of the molten solder will hold the components on the bottom side during your second pass. This is almost always the case, unless you have re
Electronics Forum | Thu Jun 22 11:02:13 EDT 2000 | Chrys Shea
Jason, Double sided reflow should be no problem. People have been doing it for years. The surface tension of the molten solder will hold the components on the bottom side during your second pass. This is almost always the case, unless you have re
Electronics Forum | Thu Jun 22 12:25:07 EDT 2000 | Boca
Jason, What Chrys said! Don't try to run the bottom cooler, tried it in the mid 80's, don't work and don't want it to work. If one side of a fab is maintained cooler than liquidus and the other side into reflow it would have an easy 40C temp diffe
Electronics Forum | Tue May 14 21:07:03 EDT 2002 | ianchan
Hi mates, Yes, the lighter mass is a valid reasoning. in addition to the "lighter (mass) than thou" point of view, 1) the first reason for mounting active Parts (eg. IC, QFP, LGA...) is to minimize the temperature exposure of the Parts to a single
Electronics Forum | Tue Feb 04 18:46:01 EST 2003 | slthomas
"Use the pad mating to lead wetting area." If I get your drift, we're talking about the minimum lead area (assuming the pad has an area that's at least as large as the lead) required to be wetted by IPC-610. Hmmmm...that would take some calculation
Electronics Forum | Tue Sep 10 08:22:36 EDT 2002 | davef
I doubt that the interposer is FR4, it's more likely to be BT. Warp during reflow is a function of material a reflow recipe. Your ramp is too fast and is causing the interposer to bend like a potato chip.
Electronics Forum | Tue Sep 07 22:15:26 EDT 1999 | NAZEEH CHAUDRY
| | | I have a zevatech 570 and 560 my boss want to place bga.s with these machines, Ive told him he needs to ugrade to newer machines. Zevatech say "no problem our machine are number 1". | | | these machines dont even offer bga selections. These mac
