Electronics Forum | Tue Apr 06 09:50:58 EDT 1999 | Justin Medernach
| Does anybody put QFP's on the backsides of boards? Can they be reflowed without falling off? Do you use adhesive? | I use a double sided reflow process all day, everyday. I've hung QFP240s with embedded heat sinks and they don't fall off. Yei
Electronics Forum | Sat Aug 26 12:26:57 EDT 2000 | Ramon I Garcia C
Hi friends: I have a problem in the process of one PCB, I have a lot of insuficients of solder in top of the board, this pcb already was working good, but sudenly began there isn't flow thru hole, I ran the profile and it was ok, if I inmerse i
Electronics Forum | Fri Sep 05 13:49:04 EDT 2008 | gregoryyork
Tell the board shop to increase the cure temp of the resist as it is undecured especially if you have waxy/greasy resiues on the board and a brown tar like substence in the solder wave itself. If undercured then solder will not flow off the resist pr
Electronics Forum | Tue Jun 10 01:09:37 EDT 2003 | iman
Hi! Thanks to you as the first replier! I do admit it "narrows" the information channels feedback flow by keeping this thread reply limited to "non-commercial" engineering folks, but I already have lotsa war stories from the salesmen around this reg
Electronics Forum | Thu Sep 26 20:43:51 EDT 2002 | davef
"OK. If the connection doesn't look like I expect it to look, how do I know that the metallurgy is correct?" Comments are: * There are no pictures that will get you though this. * You should expect that gold that is dissolved in Pb/Sn solder to make
Electronics Forum | Thu Aug 21 09:01:46 EDT 2003 | caldon
Dan- We here do double sided reflow: we place one side and reflow....place the other side and reflow. On the second flow the underside of the PCB- we will reduce the bottom side preheat. fortunatly for us the largest component we only place a 40pin P
Electronics Forum | Thu Aug 08 15:16:03 EDT 2002 | OhioD
A "Pumpprint" stencil refers to a thick DEK stencil with pockets routed-out on the underside, so it will clear any THT leads, paste/glue deposits, etc., and not squish them. It's called pummprint because it was developed to use the ProFlow-type head
Electronics Forum | Wed Apr 26 03:32:29 EDT 2006 | saaitk
Hi all, Has anyone any experience they can share with regard to pad dissolution on PTH's on thick boards. We are using lead free SAC305 on both OSP and Immersion silver finishes and are experiencing difficulties when removing and replacing connector
Electronics Forum | Mon Jun 26 08:57:17 EDT 2017 | capse
If N2 is not an option, the cut wire feeder or drilled wire are your best bet for now. You need to optimize wire feed rate as well. The solder joint on the robot takes about the same time to form as in manual soldering. If you need to speed the solde
Electronics Forum | Tue Jun 05 03:56:52 EDT 2001 | JohnW
Flip Chip/uBGA Underfill Visual Standards The aim of this document is to produce some draft text and then select photographs to make up a draft visual standard for inspection. There is also a need to produce some reference material for C Scan image
