The amount of integrated circuits with real pins on them, being capable of stuffed into a "breadboard", is rapidly decreasing. I have not been in a po sition where I needed to prototype a new design (as a hobbyist) in years. B ut now I do and while searching for a >10MSPS A/D and a FIFO memory to use with it I am seeing nothing available with pins. What are home builders do ing these days about this? Is there a company that will solder these surfa ce mount chips onto a small circuit board for a reasonable price? I bought one of those SSOP adapter boards and there is no way I can solder those tin y pins without bridging solder over the gap between pins. What are people d oing?
mandag den 22. februar 2021 kl. 17.24.44 UTC+1 skrev Deane Williams:
f stuffed into a "breadboard", is rapidly decreasing. I have not been in a position where I needed to prototype a new design (as a hobbyist) in years. But now I do and while searching for a >10MSPS A/D and a FIFO memory to us e with it I am seeing nothing available with pins. What are home builders d oing these days about this? Is there a company that will solder these surfa ce mount chips onto a small circuit board for a reasonable price? I bought one of those SSOP adapter boards and there is no way I can solder those tin y pins without bridging solder over the gap between pins. What are people d oing?
soldering ssop is not difficult, just need some flux
Currently I just buy breakout boards with the part and assorted support components already mounted. See places like SparkFun, Adafruit, Aliexpress (if you are adventurous) and others.
f stuffed into a "breadboard", is rapidly decreasing. I have not been in a position where I needed to prototype a new design (as a hobbyist) in years. But now I do and while searching for a >10MSPS A/D and a FIFO memory to us e with it I am seeing nothing available with pins. What are home builders d oing these days about this? Is there a company that will solder these surfa ce mount chips onto a small circuit board for a reasonable price? I bought one of those SSOP adapter boards and there is no way I can solder those tin y pins without bridging solder over the gap between pins. What are people d oing?
The right flux, fine solder and tip. And then some magnification. I bought something like this,
Tin the pads and use a good amount of flux, and with a fine iron and some magnification and practice you can just solder the pins one-by-one, hold chip down with a jeweler's screwdriver, tack one edge down, then the other, then nail the rest of them. The pins won't bridge if you use plenty of flux and don't use too much solder.
I tend to check continuity from the pin to the pad with a needle probe multi-meter afterwards to be on the safe side but with practice the whole process takes only a minute or two.
The only components I struggle with are the very small packages with odd pin spacing like US-8.
Once you learn how to mount SMTs to surfboards you'll never want to go back to DIPs. DIPs stink! The pins break off and then you're f***ed. Snapping a pin off a $8 DIP ic isn't the end of the world but it's sure a bummer
Jeroen Belleman wrote in news:s10n4c$183j$1 @gioia.aioe.org:
Very detrimental to the chips. That lead frame sinks heat directly into the chip die mount.
ALL soldering should be on the pin one time and for a short period and NO big blobs of solder. You probably use two irons to place MLCC caps too. Do you also walk across carpetted floors with your computer processors in hand, scraping the rug as you go?
Sheesh. Next reply will be about how it has 'never caused me any problems'.
Do you also dismiss ESD vulnerablity?
I can solder down to 0402 or even 0201 with a scope. No braid needed here. I know how to solder like a NASA rocket scientist... should.
On a sunny day (Mon, 22 Feb 2021 08:24:38 -0800 (PST)) it happened Deane Williams wrote in :
Do not know about this specific application but I have many boards with complicated chips from ebay that interface via headers.. Also I have quite a few adaptors for whatever format chips. If you go to ebay.com and type ADC module in the search window, all headers, many types of chips. Now do the same for FIFO module
I would much rather work with most SMDs than the DIPs.
I was over 60 years old and taught myself how to solder the SMDs. Just watched a lot of You tube vidios. Main thing is the proper tools. Number one for me was an Amscope stereo microscope at around $ 200. Then as a hobbist a hot air rework station for about $ 80. If I was in business I would pay about 4 or 5 times that for a professional station. It has the hot air wand and very fine tip soldering iron. sometimes it is easier to use the solder paste that comes in the needle thing and you just place the paste on the pads and hit it with hot air.
The only ICs that I can think of is the ones that have the contacts on the bottom and you just have to heat and pray everything melted and nothing shorted. They may not be as bad as I think as I have not tried that on an good piece of gear, just played a few times on some bad computer boards. The old boards are a good place to practice on before going to working or repairable equipment.
f stuffed into a "breadboard", is rapidly decreasing. I have not been in a position where I needed to prototype a new design (as a hobbyist) in years. But now I do and while searching for a >10MSPS A/D and a FIFO memory to us e with it I am seeing nothing available with pins. What are home builders d oing these days about this? Is there a company that will solder these surfa ce mount chips onto a small circuit board for a reasonable price? I bought one of those SSOP adapter boards and there is no way I can solder those tin y pins without bridging solder over the gap between pins. What are people d oing?
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Very cheap and reasonable quality. They only assemble parts on their parts list, but it is huge.
Many hobbyists use them.
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If one's doing digital prototyping SMT chips are awesome too, you mount your devices to surfboards and solder in long pin-headers "upside-down", mount them to a sheet of copper-clad with those 3M picture-hanging stickies and ground the ground pins to the copper, then use a zip-tool to wire up everything else it goes really quickly, and you can run what you get very fast on the solid ground plane.
You can do this with DIPs too but good-quality DIP wire-wrap sockets aren't cheap anymore.
Metcal iron, good optics, lead solder, good flux. My secret is to lengthen the pads on the PCB design -- it gives the iron something to heat up, and helps to drag excess solder away. Doing this makes machine-stuffing much m ore problematic, tho, so you have to choose. For QFPs with bottom pads, I put a plated hole in the middle of the design. Then, when I finish solderi ng the top pins, I can reach through the back with a fine tip and get the b ottom pad. I can do QPFs down to 3x3mm that way. Here's an example:
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t+Gate+Box
(Pardon the pics -- my official lab photographer is restricted from the lab these days.) Take a look at top and bottom pics of the FPGA board. There' s a 32-pin QFN next to the white ECO wires, with a filled-in hole on the bo ttom. As mentioned earlier, you need to work quickly when soldering the bo ttom hole, to avoid damaging the chip. As soon as the solder melts onto th e pad, remove the iron.
THANKS everyone for your inputs. There are several very good suggestions here. It seems like people have branched out on how to solve this problem and I need to see which way will work best for my situation. Best, Dean
You make a full commitment to SMD and never look back. First you download the free and professional grade PCB-CAD program called KiCAD.
You lay out your board using SMD devices. Then you buy the parts. Finally you send the Gerber files, along with print-outs of each side of the board to one of the many houses who both make the boards and then stuff them.
For repair you'll need a fine tipped soldering iron and a hot air source AUOE sells both in one box for under $200. And you'll need some fine tweezers, solder paste and water soluble flux.
Finally a stereoscope. Since I do commercial work I spent the money for a used Mantis. Instead of eyepieces you have to lean over, the mantis projects the stereo against a black background that you simply look at. John Larkin has a Mantis and can rave more about it.
An additional handy accessory is a set of heated tweezers. These allow you to solder SMD discretes, both ends at once.
If you need to attach or replace a 0.5mm IC, you'll use the hot air system to remove it. Clean the pads with solder wick Lay the new chip on the pads, apply some flux to opposite corners and hand-solder those two pins to hold them in place. Then use whatever method you have (I have an air-operated solder paste dispenser with suck-back) to dispense the paste. Melt the solder paste with the hot air gun. You'll have 4 solid rows of solder, shorting all the pins. Use solder wick to remove the excess solder. The wick will remove all the exposed solder but will not affect the solder between the legs and the pad. You're done.
Don't even think of using lead-free solder unless you want constant headaches. Use the good old leaded solder paste. The flux is water soluble so give the board a good scrubbing with dishwasher detergent and dry it in an oven set to 150 deg F.
I would NEVER go back to thru-hole construction, even for prototypes.
I use 4 layer, power and ground PCBs. The two inner layers are power and the most prevalent power, usually 3.3 or 5 volts. The two outside layers are the routable layers.
Routing an SMD board, especially a dense one, is trivially simple compared to thru-hole with just 2 layers.
Stick with DIL/leaded/through-hole. To hell with SMD. I absolutely refuse to use them. --
"Andrey Semyonovitch really was rather stupid; he attached himself to the progressive cause and 'our younger generation' from enthusiasm. He was one of the numerous and varied legion of dullards, of half-animate abortions, conceited, half-educated coxcombs who attach themselves to the idea most in fashion, only to vulgarise it and who caricature every cause they serve, however sincerely."
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