Electronics Forum | Thu May 21 09:54:07 EDT 1998 | Justin Medernach
| I'm reviewing my board fab spec. It calls for a minimum SnPb thickness of 50 microinches on HASL PWB's. I've looked at other specs that call out anything from 30 to 80 microinches, and others that just say the copper pad must be covered and solde
Electronics Forum | Tue May 26 14:50:07 EDT 1998 | Dave F
| | I'm reviewing my board fab spec. It calls for a minimum SnPb thickness of 50 microinches on HASL PWB's. I've looked at other specs that call out anything from 30 to 80 microinches, and others that just say the copper pad must be covered and sol
Electronics Forum | Tue Apr 25 21:29:08 EDT 2006 | TMC
Thanks for all the replies. Rob . . . that's what I was looking to get feedback on; to see if others can program their reflow ovens so that double sided boards only reflow on top during the second pass. Our oven does have an edge belt conveyer so t
Electronics Forum | Mon Mar 08 19:52:54 EST 2004 | Ken
I have processed the following materials in lead free processes: CEM FR1 FR4-120 FR4-140 FR4-170 Each material has different responses to thermal stresses. Issues to consider are: Panel size, smt only, wave only, double sided smt...and smt / wave
Electronics Forum | Wed Apr 06 12:36:53 EDT 2005 | smt_rookie
I've tried a different lot of the same double header connector (yes its double level right angled header conector) twice but nothing has improved. I've also suspected that top row of the connector has greater heat sinking capacity (which should hold
Electronics Forum | Thu Aug 27 11:18:05 EDT 2015 | dyoungquist
From your description I am assuming you are doing double sided reflow and parts are dropping off the bottom side when the board is run through the reflow oven the second time. A few ideas to try: 1) Are the parts that are dropping off heavier parts
Electronics Forum | Fri Nov 08 05:08:28 EST 2002 | zolasteven
Can anyone advise on the following : 1. Insufficient pcboard support during printing We are printing on double sided pc boards (approx. 8 ins by 6 ins). There is a problem of high paste when we are printing the second side. The reason bsing the boa
Electronics Forum | Thu Jun 03 12:31:30 EDT 1999 | Dave F
| | | In a month or so, we will be getting an in-line x-ray inspection machine. It will require that we solder our most comlicated side (normally top) first. This is opposite to our process now where we solder our passive (bottom) side first. We
Electronics Forum | Fri Nov 08 11:37:44 EST 2002 | jonfox
1. Back in the early days of consumer digital cell phones, we ran into the same problem. PCB with 2000 parts in a 5"x2" area, and double sided. We ended up using our standard vacuum tooling for the NIC side and stiff ESD safe foam for the NAC side
Electronics Forum | Thu Jun 03 10:53:09 EDT 1999 | Ryan Jennens
| | In a month or so, we will be getting an in-line x-ray inspection machine. It will require that we solder our most comlicated side (normally top) first. This is opposite to our process now where we solder our passive (bottom) side first. We ca