Electronics Forum | Tue Aug 11 09:52:53 EDT 2015 | rgduval
I assume that these parts are falling off during second-side reflow? The easy solution, of course, is to not build high-mass components on first-side reflow. If this isn't practical, however, you can try using epoxy/glue under the component. We'
Electronics Forum | Mon Dec 03 15:03:49 EST 2018 | dleeper
I can't open your spread sheet to see how you calculate this, but usually this sort of calculation assumes the leads are spaced symmetrically on both sides of the part and the center of mass is between them. Gravity pulls the part down, while the wet
Electronics Forum | Thu Nov 29 22:31:27 EST 2007 | shy
Hi Stephen, The component falling off is the component that had glue. the component witout glue is being covered by masking during wave. What is the meaning by populated the part and cure it? is it run with solder paste profile or glue profile or yo
Electronics Forum | Thu Nov 29 13:05:46 EST 2007 | stepheniii
I really hate to ask but must. Are the components that are falling off, the components that don't have glue? Seriously not all the parts on the bottom are glued on? How do they stay on during the wave? The normal way is to run the top SMT as normal
Electronics Forum | Tue Jun 15 12:03:27 EDT 1999 | Dave F
| Has anyone had issues where bottomside double reflowed smt has fallen off in the wave when using voc-free flux? I have verified the hotter profile was not the issue by using an alcohol based flux with no problems.This voc-free flux is also not caus
Electronics Forum | Tue Jul 03 08:14:49 EDT 2001 | Stefan Witte
If you hold your board sideways in a 90 degree angle you apply a force of 1 g to your components. 1 g translates into 32 ft / sec. square. This is not too much acceleration for fearless roller coaster drivers but Melf�s and Tantalums can fall off at
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 | Wed May 06 13:44:58 EDT 1998 | Chrys
| Dear Freinds, | DOES ANY ONE OF YOU WILL BE KIND ENOUGH TO GIVE SOME INPUT ON DOUBLE SIDE REFLOW OF COMPONENTS WHAT ABOUT BOTTOM SIDE COMPONENT HOLDING DURING 2ND SIDE REFLOW? ANY IDEA OTHER THAN USING SLDERPASTE WITH OFFSET MELTING POINT, EPOXY DI
Electronics Forum | Sat Aug 07 09:32:54 EDT 2010 | scotceltic
We have a Large LGA package (40mm X 40mm) that we are trying to process on a double-sided assembly. problem is the only space we have for it is on 1st side processing side. Therefore we have worries about falling off in the oven during the 2nd side
Electronics Forum | Wed Jun 16 15:44:52 EDT 1999 | Jagman
| WOULD LIKE TO DO RELOW OF 2 SIDED SMT BOARDS. USUALLY THE BOTTOM SIDE HAS RESISTORS AND CAPS ONLY. WHEN THE BOTTOM OF THE BOARD HEATS UP, THE PARTS ARE FREE TO MOVE AND ONLY SURFACE TENSION WILL KEEP THE COMPONENT FROM FALLING OFF. | CAN BOARDS BE
