Electronics Forum | Mon Oct 12 08:07:45 EDT 1998 | Earl Moon
| I have datas to substain that a not wetting PCB ( the HAL oxided or not uniform in thickness )if soldered in reflow, it shows voids with X-Ray inspection.The voids are in side all the joints not only on the solder pads levell. | | Is there a techn
Electronics Forum | Sun Nov 24 09:54:24 EST 2002 | davef
On a HASL board that has poor wetting on the pad, consider looking further downstream in the process than your assembly shop. For instance, take a look at the bare boards. Look for solder mask bleed onto the pads. This will show-up on the outside
Electronics Forum | Tue May 31 10:44:16 EDT 2005 | Scott B
We have found that when the HASL thickness is less than 5 microns the tin in the HASL reacts with the copper leaving a SnCu surface with poor solderability and microscopic grainy Pb islands. The IPC does not specify minimum HASL thickness but we now
Electronics Forum | Tue May 31 09:40:23 EDT 2005 | mattkehoe
We have some boards that exhibit poor solder wetting when reflowed. Nothing fancy, smallest pitch size .050. See photo's at http://www.sipad.net/SnPbwetting.htm Is this ; Contamination on the HASL finish? Insufficient solder,not enough to cover pad
Electronics Forum | Wed Oct 04 10:18:51 EDT 2006 | greg york
Now seen the Blow Holes and shallow inverted and non wetting problem an aweful lot over here. Over came the Blow Holes and shallow inverted joints by washing the bare PCB with hot Saponifier then rinse and dry = problem dissapears. Think most PCB ven
Electronics Forum | Fri Nov 16 03:38:03 EST 2018 | premkumar_haribabu
Hi all, We have to solder a nickel tabs ( coming in SMT reels ) in to HASL PCB finish pads using refow oven & during this we facing poor wetting issues, more voids & we done pull strenth , its came out with in 1 kg ,I doubt that nickel coated materi
Electronics Forum | Fri Sep 17 03:13:00 EDT 2010 | grahamcooper22
In HASL pcb coating you need to fully coat the pads with solder and then blow off any excess solder to leave a nice coating on each pad. Generally pcb manufacturers try to give you a flat pcb pad to make your solder paste printing more consistent. To
Electronics Forum | Tue Apr 15 03:16:14 EDT 2008 | janz
Hello, We are having a problem with soldering QFP100 (16mmx16mmx1mm). Board dimensions: 70mmx50mmx1.8. FR4 two layers � single SMT assembly. Finish: HASL-lead free Oven: 7 zones �hot air Paste: lead free We have noticed that two groups of legs
Electronics Forum | Fri Nov 23 05:59:18 EST 2018 | premkumar_haribabu
Hi RObl, Thanks for response , sorry to ask again & again . Is cobar paste solved the issues from poor wetting from nickel to PCB soldering,whether it will improve the peel off strenth more than 5 kg ?? as per our current last production , this nic
Electronics Forum | Wed Jun 08 13:49:48 EDT 2011 | sonofptolemy
Hello, I am having a problem with HASL PCB's after it comes back from the stuffer. To me it looks like oxidation and it causes poor wetting. This leads to a bunch of problems all of which have different symptoms but the cause is this oxidation proble
