First foray into SMD components this evening. I still haven’t quite figured out my preferred technique. Currently using flux pen to prep the pads, then stick a solder blob on one pad and lightly tin the other pad. I then get the component (all resistors in this case) in the tweezers and heat the solder blob so that the component can be plopped into it. Heat still applied I push the other end of the component down onto the tinned pad then add a bit more solder to improve the joint.

Still not tested anything yet, but I’ll grab the schematic tomorrow and figure out the best way to test the components.

Feel like I need a double pronged soldering iron tip that I can apply to a blob on both pads at once so that I can put the component down a bit more symmetrically.

Tested it live in production (ie threw it into the rack rather than testing components/traces) and it all seems good except for the “1+2 4+7” jack. No LED or signal even if I’ve manually set all bits on the Turing Machine to on. Need to check the resistor I think.

The resistor was fine, but after checking the schematic I was able to work my way back from the non-functioning output/LED to the AND gate where it seems like I didn’t do a great soldering job. A quick touch up on 3 pins and everything is working perfectly now.

@mo
Two soldering irons is the way I do it. You can get those tweezery thingies... but two irons is the easy way.

@mo If you haven't watched the EEVBlog videos on YouTube about SMD, they're pretty helpful, or at least they were to me. :)

I don't bother to tin the 2nd pad -- I just flux, blob one pad, butt the component (yes w/tweezers, absolutely essential!) up against the blob, then heat 'em both until the solder flows. Then just whack the other end with a dab of solder, not much different technique-wise (other than amount) from thru-hole.

The *most* valuable thing for me was getting a decent light source & a magnifier. I had one of those swing arm magnifiers with built-in light but eventually I got so nerdy I wound up with one of those head-mount magnifying visor things.

I don't know what you're using solder-wise but I just use 0.5mm for both SMD and thru-hole & it's A-OK for me. Good luck!
Sign in to participate in the conversation
NI Tech

The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!