Electronics Forum | Tue Sep 06 12:39:06 EDT 2011 | deanm
According to IPC-7351A, the optimum fiducial is a solid circle with a minimum of 1mm diameter, but can be up to 3mm. There should be a solder mask clearance a minimum of 2x the radius of the copper circle. So the minimum fiducial size is 0.040" with
Electronics Forum | Mon Feb 11 13:07:30 EST 2013 | deanm
You want your machine to spot the fiducials automatically. A 40mil round copper pad is the absolute minimum fiducial to use, but we found in practice that our Quad equipment won't spot them reliably. I am now using a 60mil round fiducial and it picks
Electronics Forum | Mon Jul 21 20:42:12 EDT 2003 | iman
Don, thanks for the thoughtful insight, can I run some thinking points for your further assistance? 1) ours is a Au over Ni PCB bareboard. Do you think excessive Au thickness is any way a influence for poor solder formation? I did notice the PCB ba
Electronics Forum | Tue Jan 24 07:43:45 EST 2006 | Chunks
Q: If you do not use a selective wave pallet does this not leave the possibility of solder flowing up thru the Via's on the board? A: No. Your board house can cover your vias with solder resist. Your board house can plug the vias. You can cover t
Electronics Forum | Mon Mar 05 16:16:08 EST 2007 | Mark
Hello, We are having issue with one of the customer board. This is 10 layer PCB FR4 with black solder mask. Coating Ni/Au. Soldering leadfree. We are using 7 zones air reflow oven (zones top&bottom). We have bed solder flowing for this boards. T
Electronics Forum | Tue Jan 08 10:10:29 EST 2008 | noid
We are building class 3 products, using no clean on wave and selective solder machines. Both processes are producing micro solder balls between the leads of through hole components. I have searched the site and haven't found any recent threads on h
Electronics Forum | Sun Jan 31 03:28:24 EST 1999 | Jeff Sanchez
| Hello Netters, | | I need some info, Earl or Dave, I have a PCB that exhibits a white layer on solder side. It does not appear to be surface residues (IPA has no effect), but looks like its under solder mask. My first guess is that the LPI solde
Electronics Forum | Mon Nov 02 22:57:02 EST 1998 | Kelly Gossman
Micheal, What does your profile look like for the wave? What profile does your flux say you need? My guess is it is not your profile, our testing with solder balls found that the mask on the boards was the largest contributor to solder balls. Wha
Electronics Forum | Wed Apr 14 17:39:20 EDT 1999 | Dave F
| Can someone explain the difference between solder "fines" and solder balls? Is there an official specification where "fines" are defined? What is the spec for "fines"? | | I consider "fines" individual unmelted metal spheres that are found in s
Electronics Forum | Wed Oct 25 13:42:32 EDT 2000 | Chris McDonald
I was wondering IF anybody has has success wave soldering a 50 (2 rows of 25) pin 0.050" pitch thru-hole connector. I seem to be getting alot of bridging no matter what I do. Is there a design spec for the size and shape of pads? The pads on the pcb
