Electronics Forum | Mon Sep 20 10:17:19 EDT 1999 | Jeanjean
Hi all, As a student in elctronic sciences, I'd like to know why there is a difference in the voltage required for PC boards with surface mounted devices and the voltage needed by traditionnal components like leaded film capacitors? I wonder if it
Electronics Forum | Mon Sep 20 11:50:26 EDT 1999 | Wolfgang Busko
| Hi all, | | As a student in elctronic sciences, I'd like to know why there is a difference in the voltage required for PC boards with surface mounted devices and the voltage needed by traditionnal components like leaded film capacitors? | | I won
Electronics Forum | Fri Dec 27 14:24:15 EST 2019 | ameenullakhan
Yes we have tried with low soak with longer reflow and high peak also low soak.. short TAL and low peak.. but were not able to eliminate the issue
Electronics Forum | Tue Mar 27 01:52:23 EDT 2018 | buckcho
Hello Diego, are the components missing on the first side or the second side. Like Mr. Evtimov said, you can check before the oven the pcbs's visually and see what happens after the oven. In this way you can see if it is the oven for sure. Then there
Electronics Forum | Mon Jun 18 10:11:52 EDT 2007 | dyoungquist
Almost every board/panel we build is double sided and we use an MPM SPM screen printer with no problems. The screen printer is not the cause. We have seen heavier parts fall off the first side when going through the reflow for the second side. We
Electronics Forum | Wed Jun 13 15:56:35 EDT 2007 | ck_the_flip
I experienced this with a high-mass capacitor. I was able to turn down the bottom-side convection (around 50�C lower than each of the top-side heaters), and able to NOT lose any parts. I got the bottom-side part just slightly over liquidus, and min
Electronics Forum | Wed Jun 13 14:48:48 EDT 2007 | rgduval
Is there a sort of standard method to prevent part loss in reflow? I've had a couple of situations come up recently where we've lost some parts during second-side processing. We're running an Heller 1800, with a mesh belt. Most items process fine,
Electronics Forum | Thu Aug 25 20:00:31 EDT 2005 | Dave
Try Heller Industrie's website at http://www.hellerindustries.com They have a formula that they offer for free that calculates land pad geometry to component weight to prevent drop off of components during second reflow. If you can't find it, give t
Electronics Forum | Sat Aug 13 11:14:11 EDT 2005 | Ftiscar
Does any body knows if there is a design rule on copper pads against component weight so they do not drop on secon reflow process?
Electronics Forum | Sat Nov 23 10:19:39 EST 2002 | davef
This sounds alot like the warping that we all see periodically in BGA. CTE of material is temperature dependent and not temperature changing rate dependent, so you are pretty much hosed by the physics. Regardless, I do like trying like crazy to g
