At the risk of showing my age, wondering what you guys prefer...

Personally, I tend to favor through hole stuff as I can wire-wrap designs (yes!) without having to fork out money for PCB's, stencils and other crap. While it's getting harder to find parts, it's a heck of a lot easier to just solder and repair, especially when you socket the bigger parts.

Thoughts?

Yvo

Doing SOJ's and SOIC's by hand does not require soldering one lead at a time. Start out by tacking two opposite corners just to hold the part in place as you start the real soldering at a third corner. You just flood the entire side with solder, using a tip that covers two or three leads at once, leaving lots of bridges. When you're done with both (or all four) sides doing that, then hold it vertically and go from top to bottom of each side again with the iron, and all the excess solder comes off on the iron, leaving an even amount of solder on every pin, just right. It's amazing how easy it is! It's helpful, but not imperative, to use extra flux. If you do use extra flux, then you have to wash the whole gooey mess off.

Arlet tells of, and shows the results of, his solderwick method of hand-soldering an FPGA with 0.5mm lead spacing, where he uses the solderwick to apply the solder rather than remove excess. Beautiful! See his post at viewtopic.php?f=4&t=2747&p=29941#p29941 .

Hand-soldering chip capacitors and resistors is easy enough with a tiny soldering iron down to approximately 0805 size. 1206 is really easy. 0603 is starting to get harder.

Pololu will make solderpaste stencils from your gerber file and they're not very expensive either; but solderpaste's shelf life is pretty short which may not be practical for non-commercial applications where we would go months (or years) between uses.

I do like wire wrap though, for one-off digital stuff. You can get perfboard with planes on both sides if you reall want good AC performance. I have a page on WW Q&A at http://wilsonminesco.com/6502primer/WireWrap.html and on getting good AC performance at http://wilsonminesco.com/6502primer/construction.html with links at the bottom to related forum topics and to ap. notes.

For making custom PCBs, I might still use some thru-hole, and socket the PLCCs. (I have damaged an I/O IC a time or two by what I connected to it, so being able to replace it quickly without damaging the board was a plus.) Connectors should usually be thru-hole also, so they don't peel up the foils on the PCB. A few parts actually take more room in SMT, to allow for leads that come out the sides instead of going through the board underneath, or sit up on a platform that needs solder fillets around it (like electrolytic capacitors). Thru-hole also lets you put parts under parts in some cases, so its density can be higher than one might have thought. There's nothing wrong with doing a mix of thru-hole and SMT. As you noted, some parts (especially logic ICs) are only available in SMT. I've been getting some key 74ABT parts as I find them available, but I've had to get some of them in SMT (SOIC), then use the SOIC-to-DIP adapters if I want thru-hole.

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There's no doubt that through-hole parts are easier to work with and lend themselves to wire-wrapping. Most of the standard logic parts continue to be available in through-hole, and in fast logic families, e.g., 74AC and in some cases, 74ABT. So for a first-time effort, I'd suggest working with through-hole. I don't recommend socketing glue logic, however, as doing so unnecessarily increases parasitic capacitance, as well as space consumption. Reliability can also be negatively affected in some cases—usually when cheap tin-plate sockets are used.

Once you decide to make the transition to a PCB and/or high clock speeds, you might want to consider using SMT packages, such as PLCC and SOIC. PLCC sockets are readily available and contribute negligible parasitic capacitance. SOIC parts are on 50 mil pin spacing, which can be a challenge to solder, especially for old dinosaurs with weak vision, but as Garth noted, not at all impossible. I used a J-leaded SOIC SRAM on both of my POC units, and a gull-wing leaded SOIC version of a MAX-238 transceiver on my POC V1.1 unit (see attached). I got good connections on the first try and no shorts. The 26C92 DUART, W65C816S MPU and 53C94 SCSI controller ( latter not shown) are all PLCC packages mounted into sockets.

It's possible to manually solder a PLCC package directly to a PCB, but not something I would do with a hobby build or a prototype.

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Thanks!

I've made a number of surface mount boards, hence my aversion to them. While SOIC and others are indeed easier, the 0.5mm quad packs with bottom heatsinks means you either have to use paste or, as I did, stick a large-holed via underneath. Either way, come debugging time, it's a lot easier to stick a clip on a DIP rather than probing around. Granted, test-points help but I usually end up putting those on pins that don't need testing

Yvo