Electronics Forum | Fri Jul 20 17:09:10 EDT 2001 | davef
Circuits Assembly magazine 09/99 "Defluxing with Ultrasonics" by Les Hymes. [There's more but I can't find it right now. I'll add to this as I find the junk, er very nice stuff.] J-STD-001C states that its OK to use ultrasonics for cleaning so lon
Electronics Forum | Tue May 11 15:52:03 EDT 2004 | Erhan
It's been 10 years since I started to use this editing method but never knew that it was called wendy-house style. :-) This is most probably the answer you're looking for if you're only having problems around the 1206 types. For QFPs, I used to redu
Electronics Forum | Wed May 12 07:53:28 EDT 2004 | solderpro
Lets make it easy on the poor guy, some are correct, check you profile but remember one thing most do not apply, it is important to match the type of paste you are using with the style of oven and configuration. send a direct email and I will give so
Electronics Forum | Thu Jun 24 23:00:36 EDT 2004 | yukim
Tried with several lots of solder paste, manufactured in Feb and March this year. Work ambient: 25C, 60~70%. Is this humidity too much? I'll reduce the ramp in our profile. One change: We changed the conveyor motor in our reflow oven just before the
Electronics Forum | Sat Jul 03 08:52:19 EDT 2004 | davef
Q1: What's the difference between static and dynamic viscosities? A1: Static viscosity is the viscosity of the solder paste as it is dispensed off of a tube or syringe onto a screen printer. Dynamic viscosity gives the variation in the thixotropic b
Electronics Forum | Thu Jun 24 02:31:24 EDT 2004 | yukim
Currently we are having a lot of solder balls, after a few hours of continous production. This is how we work: load new solder paste at the beginning of the shift, less than 500grms. Then, the operator loads new solder paste periodically, every 3 to
Electronics Forum | Wed May 09 11:25:29 EDT 2001 | medernach
What type of preheaters do you have on you're wave? I have to agree with Dave. Your leads are not cold, they are hotter than the annular ring on the PCB. This would cause the solder to go to the lead only rather than the component and land pad / a
Electronics Forum | Mon Jul 16 21:29:03 EDT 2001 | davef
Cleaning RMA with water is bad news. It will turn your solder connections white and remove none of the RMA residues. There was a thread on removing RMA within the past two weeks on SMTnet. Check the fine SMTnet Archives. Additionally, look at M
Electronics Forum | Tue Jul 17 15:13:53 EDT 2001 | mparker
Dave - I agree that the U shape for QFP's sounds a bit whacked, for the reasons you state. It may work OK for larger pitchs but then again there are a myriad of fixes that work before resorting to U shapes. With the U shape removing paste from under
Electronics Forum | Mon Jul 16 21:25:26 EDT 2001 | davef
Sure, use of U-shape apertures is another way to reduce the amount of paste that you apply. That and similar schemes mentioned in the article are not a function of the flux used. We have used U-shaped apertures for MELF and mini-MELF. They are sug
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