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 | Sat Mar 21 12:19:51 EST 1998 | David Pick
I have read somewhere of a ratio of component weight vs. surace contact area rule for double reflow soldering. This ratio is the maximum weight vs. surface tension to hold a component on during the second reflow. With this number, a person could weig
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 | Tue Feb 04 08:20:18 EST 2003 | roertner
This rule is very conservative depending on the epoxy you use and the subsequent handling of the board prior to reflow. You should use lead to pad contact area. Also be sure to look at part height and clearance on your flowsolder machine.
Electronics Forum | Tue Sep 11 09:13:01 EDT 2001 | davef
Like most things in electronic assembly, this is not astrophysics. People have pasted boards, placed components, turned the board up-side down, run the board through a reflow oven, and generalized about which components: * Fall off the board. * Don
Electronics Forum | Tue Sep 04 18:11:18 EDT 2001 | davef
Assuming you're asking about double sided reflow soldering ... Use pad mating to lead wetting area. Bob Willis has found the ratio to be as much as 44 grams/sq in. Check Bob's site [Electronic Presentation Sevices] for more. Phil Zarro uses the
Electronics Forum | Tue Mar 24 17:08:52 EST 1998 | Steve Gregory
David, There was a thread going on the IPC TechNet about exactly the same thing... The ratio that was posted is: Less than, or equal to 30-grams per square inch Which means if you weighed a part and it is 30-grams, you'll need .033" of surf
Electronics Forum | Thu Oct 19 12:34:36 EDT 2000 | lwatson
I can't seem to find an article about the limiting mass of a SMT component on the solderside of a double-sided reflowed PCB. I'm pretty sure that Phil Zarrow did an article on this subject. It went something like the mass/land surface area?
Electronics Forum | Tue Apr 07 05:41:34 EDT 1998 | Bob Willis
Based on work I have been doing recently the most common reasons for component loss is board flexture and vibration on the reflow process. If parts do not reflow then weight is not an issue. There is a video on double sided reflow and PIHR from the S
