Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Indium No-clean and Inert Reflow oven (N2)

#20993

Indium No-clean and Inert Reflow oven (N2) | 31 July, 2002

Anyone have experience with Indium NC-SMQ92J solder paste used in an inert (N2) reflow oven?

reply »

Dave G

#20994

Indium No-clean and Inert Reflow oven (N2) | 31 July, 2002

Used this paste on ENIG boards W/O N2 and had very good results. (0402's,BGA's,16mil FP) Never had the need to use N2 with this paste on our products. Running with N2 shouldn't hurt anything. The wetting properties should get even better than they are without N2. We switched to this paste to help with solderability problems with some RF filters with castellations.

DG

reply »


RDR

#21009

Indium No-clean and Inert Reflow oven (N2) | 31 July, 2002

Never used an inert atmosphere with this paste but always had great success with it. It leaves a pretty fair amount of residue but that was its only downside if you could call it that. do you need to run inert?

reply »

#21014

Indium No-clean and Inert Reflow oven (N2) | 1 August, 2002

Just exploring options to improve wetting. It turns out our facilities dept is looking at an N2 generator to supply dry boxes. Thought it might be a good idea to assess whether we should expand the project to include reflow.

reply »

JohnW

#21024

Indium No-clean and Inert Reflow oven (N2) | 1 August, 2002

we run the paste in both air and n2 depending on customer requirements again it run's fairly well in both. Some people say it's better sme say it doesn't make a bit of difference, I'm somewhere in between at the moment. I definately think there's improvments in wetting if you have even slightly dodgy parts as it'll cut down on new oxides I guess. There's various report's kicking round about N2 usage and BGA voiding, indum themselves have some good papers, basically surface tension and oxides seem to be part of the voidign issue, N2 would have an effect on both of these , not always good.

John

reply »

#21025

Indium No-clean and Inert Reflow oven (N2) | 1 August, 2002

Its interesting. It appears I'm getting conflicting feeback from Indium.

This says its not a problem...

http://indium.custhelp.com/cgi-bin/indium.cfg/php/enduser/std_adp.php?p_sid=kTDKGClg&p_lva=&p_faqid=355&p_created=1014734692&p_sp=cF9ncmlkc29ydD0mcF9yb3dfY250PTcmcF9zZWFyY2hfdGV4dD1OMiZwX3NlYXJjaF90eXBlPTMmcF9wcm9kX2x2bDE9fmFueX4mcF9wcm9kX2x2bDI9fmFueX4mcF9zb3J0X2J5PWRmbHQmcF9wYWdlPTE*&p_li=

This says it could be a problem...

Question Reference #020731-000000

Subject: Can NC-SMQ92J be used in an inert reflow process using Nitrogen? Will anythin... Product: Solder Paste and SMT Assembly No-Clean Category: Process Submitted: 07/31/2002 10:23 AM Last Updated: 08/01/2002 07:19 AM Status: Solved Discussion Thread Response (Jake Lutke) 08/01/2002 07:19 AM Nitrogen is not recommended for use with NC-SMQ92J. The paste was designed for use in an air environment, and may result in tombstoning or solder balling if used in Nitrogen. Customer (Gregory Stanton) 07/31/2002 10:23 AM Can NC-SMQ92J be used in an inert reflow process using Nitrogen? Will anything be gained? Can it improve joint wetting characteristics?

reply »

JohnW

#21036

Indium No-clean and Inert Reflow oven (N2) | 2 August, 2002

interesting, not at all what we were told so yes lot's of contradictions comming from them, I have to say personally I've not beein impressed with there technical service of late, are they getting complacent I ask?

it's strange they say it'll cause tombstoning, it's unusal for a paste manufactutrer to actual state that, I know I've seen it but generally you can trace it back to poor print set up or bad placement or in my last case to a poor board design for thermal stablility, not sure I agree with that, besides the 'flavour' or the paste would also have an effect if your runnign a 2% silver then you have more chance of a tombstone due to the better wetting and obviously the nert atmosphere would add to this. as for the solder balling, erm I can say with hand on heart never seen it (well not on a correctly set up product anyways) Like I said I've been running it for a good number of years both in N2 and air and had no problm=ems, certainly on boards with higher complexity, BGA, CSP we do it as standard plus you'll find that your flux residues aren't as hard so it pin test's better than when run in air although that's not too bad either. Guess it's down to you weighing up the cost of the N2 although in yoru case with your generator it shouldn't be too bad.

JohnW

reply »

reflow oven profiler

Reflow Oven