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Post by chinook9 on Feb 10, 2016 15:57:54 GMT
Occasionally when soldering a component to a PCB I get a joint that appears similar to the one in the right of the graphic (Please ignore other problems.). When I get one of these joints, the solder appears to build up quickly and I believe it does so because the solder is not flowing into the hole at all. These joints seem to be good but not as good as I would like. I would like recommendations on what I might do to prevent this. I have not tried putting liquid flux on the component post and I haven't cleaned the PCBs before starting. I use a 60 watt soldering station with a small chisel tip (2mm I think) at a temperature of 440 centigrade. At this temperature I move very quickly. Attachments:
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nils
valued member
Posts: 7
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Post by nils on Feb 10, 2016 16:58:51 GMT
Clean your Boards with Isopropanol and use lower Temp. Lead free Solder flux works up to ~ 410C° and Lead based up to 370C°. At higher Temps the Flux will vaporize too quickly. Put the Tip at the joint to pre-heat 1-2 seconds and then apply the solder wire. Have fun!
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Post by chinook9 on Feb 10, 2016 19:08:02 GMT
Thank you for the reply Nils. I was wrong in my original post. I just checked and my soldering station is set to 369 centigrade which is right at 700 fahrenheit. My solder is Snb63/Pb37 .032 diameter. It seems to work quite well.
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solderdude
Administrator
measureutternutter
Posts: 4,882
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Post by solderdude on Feb 10, 2016 19:11:29 GMT
What Nils said... And also, when applying a little too much solder it will also 'bulge' a bit. It could be that the solder doesn't go inside the hole. Use some soder-wick to remove excess solder and then reflow it with a tiny amount of fresh solder should help. pre-tinning the component leads may help. Most parts nowadays are lead-free tinned and this 'oxidizes' somewhat faster.
Also different types/brands of solder and above all the flux in it can also affect how it looks.
I have my soldering iron (use lead based solder) at around 375°C. I only set it to a higher temperature when soldering things like the tabs of OPA552 or something like that.
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Post by chinook9 on Feb 11, 2016 3:22:49 GMT
Thanks for the input Frans. I agree that the solder probably is not going in the hole. I will probably try tinning the component leads a bit and see how that goes.
I have used a solder sucker to remove the excess solder but I'd like to get it right the first time. It might also help if I gave the component leg a bit more time to heat up also.
If I can't get all the joints looking pretty I'll just live with what I have.
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