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Got told my solder joints looked "like a 5 year old did them" by a veteran tech last month

He showed me how to clean the tip twice as often and use a tiny bit more flux, and now I haven't had a callback on a board repair in 3 weeks, what's your go-to tip for keeping joints clean?
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3 Comments
the_viola
the_viola14h ago
A 24-hour old sponge and a dirty tip gave me joints that looked like they were drawn by a toddler with a crayon. @beth_park nailed it about those grainy joints on ground planes, I had a power supply fail after two weeks once and the whole thing looked like sand under a scope. Now I wipe the tip between every joint and hit it with a dab of flux on the thicker pads, cuts down on the rework time a ton. Still waiting for my five-year-old level though, maybe next year.
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kellygrant
Three weeks without a callback is good but I mean were you getting a ton of callbacks before? Maybe that guy was just being dramatic about the joints looking bad and you were probably fine the whole time. A bad solder joint usually shows up right away not weeks later so I'm not sure how much the tip cleaning changed anything. Could be you just got lucky with a streak of easy boards.
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beth_park
beth_park1d ago
Three callbacks in a month before that, so yeah, the drop to zero felt like something changed. @kellygrant, I hear you on the luck factor, but those callbacks were all on boards with joints that looked fine under a scope, and they'd fail after a week or two of vibration. The tip cleaning might not be the whole story, but it's the only thing I swapped in my routine. Solder joints on a power supply rail can take heat cycles to crack, not just show up right away. I've seen that happen with bad wetting on thick ground planes. It's not dramatic to call a joint bad if it's got that grainy look, it's just a sign the iron wasn't hot enough or the tip was fouled.
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