Hello,
I have a hot air rework station... a chinese crap I might say.. but it helped me to manually assembly many PCBs in SMT and TH technology. What I ask you guys now is if any of you knows how to make all those joints shiny USING the hot air station. Mine are getting dry after cooling and recently I had few problems with the boards I'm making.
I want add that I'm also using a cheap iron with a cleaned tip and, compared with the hot air station joints, these are the ones that I want!
Few notes:
* The boards have 0402 to 1206 SMT parts and 100TQFP chips on it. There are also few caps and connectors in TH specs.
* I'm aware about that leadd fee crap and it's dissadvantages thus I don't use it in my work. Instead I use 60/40 solder.
* I've tried various fluxes like: AMTECH RMA-223-TF (for lead free .. yes I know I should't mixed with lead based solders!). The best I can find now is PPD type PD-223 BUT it's not enough... the joints are still matte.
* The air quantity is fixed at minimum all the time to avoid pushing the fluxes aside @ temp 360C. Maybe the temperature is too high.... don't know!
* After the board is fully assembled, I wash it with 99,6 isophrophyl alcool - (double bath) and dry it with the hot gun (at 100C temps and air at maximum).
* In the end, the joints are shiny (a little bit) and for a short while. Unsatisfactory :|
What I should have to do to preserve that shiny aspect of my joints? I've searched on the net for various combinations of solder/fluxes but nothing valid for now. No clean flux will be my next experiment hoping will do the trick!
Thank and sorry for english!
L
I have a hot air rework station... a chinese crap I might say.. but it helped me to manually assembly many PCBs in SMT and TH technology. What I ask you guys now is if any of you knows how to make all those joints shiny USING the hot air station. Mine are getting dry after cooling and recently I had few problems with the boards I'm making.
I want add that I'm also using a cheap iron with a cleaned tip and, compared with the hot air station joints, these are the ones that I want!
Few notes:
* The boards have 0402 to 1206 SMT parts and 100TQFP chips on it. There are also few caps and connectors in TH specs.
* I'm aware about that leadd fee crap and it's dissadvantages thus I don't use it in my work. Instead I use 60/40 solder.
* I've tried various fluxes like: AMTECH RMA-223-TF (for lead free .. yes I know I should't mixed with lead based solders!). The best I can find now is PPD type PD-223 BUT it's not enough... the joints are still matte.
* The air quantity is fixed at minimum all the time to avoid pushing the fluxes aside @ temp 360C. Maybe the temperature is too high.... don't know!
* After the board is fully assembled, I wash it with 99,6 isophrophyl alcool - (double bath) and dry it with the hot gun (at 100C temps and air at maximum).
* In the end, the joints are shiny (a little bit) and for a short while. Unsatisfactory :|
What I should have to do to preserve that shiny aspect of my joints? I've searched on the net for various combinations of solder/fluxes but nothing valid for now. No clean flux will be my next experiment hoping will do the trick!
Thank and sorry for english!
L
Last edited:
Ok - Manual hot air stations are a useful for some kinds of parts. Many leged find pitch parts yes, specialized plastic and ceramic packages with pins that you cant get at from the top, yes. When it comes to 0402 1206 two legged pats, use a regular soldder iron. Air is usefull in about 10-15% of soldering. Shiny joints are not the highest goal, good joints are. Clean the tip with a wet sponge frequently, and use the correct size tip for the job.
Thank you guys for your time!
@firechief: I don't recall to have a problem with the joints.. at least not until now. Mainly, most of the problems were arised by the poor quality of the printed circuit board... via connections that are affected by the temperature drifts... or short circuits between tracks.
@LAJ: it would be beautiful to have that joint look
... I also know that it's not possible to reach this goal.
Do you use the "No clean" fluxes? How they are compared to the rosin based ones?
@firechief: I don't recall to have a problem with the joints.. at least not until now. Mainly, most of the problems were arised by the poor quality of the printed circuit board... via connections that are affected by the temperature drifts... or short circuits between tracks.
@LAJ: it would be beautiful to have that joint look
... I also know that it's not possible to reach this goal. Do you use the "No clean" fluxes? How they are compared to the rosin based ones?
hmm, hand soldering 0402 is a bit of a hard ask to do consistently, down to 0603 no problem, but i'm with the other guys, these things are for rework and removal IMO, make yourself a over reflow controller if you want this kind of look. most likely the hot air is evaporating the flux that leaves the joints a bit dry and dull
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