5 ms·
Provided you have good eyesight and steady hands, I've mostly found what happens as you get smaller is: - Heating becomes easier. There's no large sinks to tak
by alnwlsn 8mo ago
Provided you have good eyesight and steady hands, I've mostly found what happens as you get smaller is:
- Heating becomes easier. There's no large sinks to take the heat away. It's also easier to overheat things.
- You need finer tweezers, and don't drop them because if you do the tips will bend.
- The solder's surface tension does more of the work. It feels a lot more like sticking together things with tiny droplets of glue. Having the correct amount of solder in the right place is critical.
- Solder and flux become two separate things you have to care about individually
- It is easier to burn yourself
- learning how to brace your hand against something in a way that gives you very fine control. One reason soldering with an iron can be difficult is because your hand is so far away from the tip, like trying to write with a pen held by the end.
- godelski 8mo agoWhen I started my first job a coworker encouraged me to learn how to solder SMDs and do "microsoldering". Like most people I thought I was going to need high precision and a much steadier hand. Probably like most people that learned I was impressed at how quick I picked it up. I think the hardest thing was learning about part "tombstoning" but that's not that difficult to deal with. I'm not going to say it is easier than soldering through-hole components, but I think for most people the mental barrier is much higher than the actual barrier. I now highly recommend learning it to anyone doing electronics. It's well worth the (small) time investment and makes things a lot easier, opening lots of doors. Even for a hobbyist you immediately get benefits. Everything becomes more compact, 2 sided boards are much more usable, and, of course, it opens up a lot of repairability (and recycling. Are you really a hobbyist if you aren't desoldering and reclaiming parts?).
- foresto 8mo ago> Are you really a hobbyist if you aren't desoldering and reclaiming parts? Fun memory from who-knows-how-many years ago: While installing a Playstation mod chip, I accidentally dislodged a nearby surface mount resistor, pulling off one of its metal contacts in the process. (Is that what happens when you overheat them?) I didn't think that was fixable, and since it was Sunday, the local electronics shop was closed. I ended up disassembling an old junk digital camera that hadn't yet been taken to the e-waste recycling drop, and finding inside it a resistor that seemed close enough to maybe work. The transplant was a success, and the Playstation ran great thereafter. Very satisfying.
- idiotsecant 8mo agoI recently got rid of a lot of components that I have salvaged and hoarded over the years. If I need a doodad for something I'll just buy it. I'm done storing all this junk I will never use
- sokoloff 8mo agoAgree that SMD hand assembly is easier than it looks, at least down to 0603 imperial. If I can wait the week for boards to arrive, I’ll often skip the breadboard step and go straight to a proto PCB, especially since most parts aren’t available in throughhole without waiting on dev boards anyway. When you hand someone a board with 0603s on it that you hand-assembled, it seems like magic to people who stop to think about it.
- SauntSolaire 8mo agoWhen you're regularly dealing with 01005's, getting to work with an 0603 feels like a luxury.
- dotancohen 8mo agoI tune my resistors by whittling away at the PCB traces you insensitive clod.
- SauntSolaire 8mo agoYou joke, but embedded passives are a thing!
- sokoloff 8mo agoAs are laser-trimmed precision resistors...
- the__alchemist 8mo ago> The solder's surface tension does more of the work. It feels a lot more like sticking together things with tiny droplets of glue. Having the correct amount of solder in the right place is critical. I believe this is why I have an easier time hand-soldering BGA than QF[np]: I can't screw up solder amount/evenness.
- nxobject 8mo agoWhat tools do you use for BGA soldering? I’ve seen people (well, dosdude1) using board preheaters and hot air stations, but I could never justify the expense for the amount of board rework I actually do.
- the__alchemist 8mo agoHot plate, flux pen, hot air gun. Important caveat: The downside to this is you can't inspect it (without an x-ray machine), and if you screw up, you're going to need a new chip (Re-balling does not look approachable/time-efficient)
- nxobject 8mo agoThank makes sense, thank you! Is there a rule of thumb for how high you set the hot plate? I’d be worried about SMD components on the side in contact with the hotplate.
- the__alchemist 8mo agoYou're right that that is a concern. I think I set mine for 190C? Don't remember. But as you infer, my goal is to get it slightly below melting temperature so the the other components' solder doesn't melt. (Disaster if they do, then the board gets jostled or you knock a component with tweezers). Then when you hit it with the air, just that component melts. Also, it seems to not melt if you don't flux the pads prior. Not really sure why.
- estimator7292 8mo ago
- dlcarrier 8mo agoHow are you burning yourself? I've only ever worked with one person who burned himself soldering when working on a SMT PCBs, and it was while desoldering a through-hole connector, when a desoldering station was long past its cleaning interval and it dripped some solder onto a metal ring he was wearing. This was a guy who would lick a soldering iron to see if it was hot and touch the molten solder in the wave solder machine. The Leidenfrost effect goes a long way.
- Kiboneu 8mo agoAn easy one is heat transferring through an SMD component to your tweezers, while trying to gently remove it from a heavy ground plane.
- retatop 8mo agoI do a lot of soldering at my day job to bodge boards, tune networks, etc. I burn myself on the time because when I'm working through the microscope I seemingly forget I have hands or lose track of them and bump the iron into them when pulling it away from the work. Not sure why, but it's really easy for me to get into this mode where the view through the scope is the only thing in the world
- alnwlsn 8mo agoMy #1 way is from impatiently touching the board to see if it's cool enough to touch yet. That sounds dumb and it is. More generally, with iron soldering only the iron and the last couple joints are hot. For SMD, there's more places for the heat to go; sometimes the entire board can be hot. Sometimes, you might need to balance being close enough in to get a good grip on the tiny parts, but far enough to not get burnt. You will feel the heat when SMD soldering - it's not always dangerous but another thing to pay attention to.
- dlcarrier 8mo agoI have been impatient, and pulled a board out of the reflow oven while it's hot enough to burn, but it's fiberglass and resin, so it has very low heat transfer, giving enough time to put it down, without getting burnt.
- userbinator 8mo agoOne reason soldering with an iron can be difficult is because your hand is so far away from the tip, like trying to write with a pen held by the end. Newer irons, especially for SMD work, have gotten smaller and the grip-to-tip distance also shrunk; here's a good visual comparison: https://www.eevblog.com/forum/reviews/grip-to-tip-distance-of-various-soldering-tools/ https://www.eevblog.com/forum/reviews/grip-to-tip-distance-o... It's worth noting that the longest one there is already much shorter than the classic mid-century unregulated irons, and all of those can be held like a pencil.
- kjs3 8mo agoProvided you have good eyesight and steady hands I see the flaw in your clever plan...