Prototyping - use small perfboards instead of solderless boards - just do it! - Page 1
Forum section: electronics / projects

author: THDplusN_bad
author_rank: Regular Contributor
timestamp: March 18, 2022, 08:32:46 pm
content: Good Day,I am aware that the subject of solder-less prototyping board's contact reliability (also known as breadboards) has been discussed at length...However, I just wanted to encouragebeginnersto pull-out their soldering iron and use perfboards with soldered components rather than prototyping boards for any circuitry that requires more than a handful of connections.This can really prevent frustration.You veterans may just skip reading this, as it is an old hat for the more experienced engineer or hobbyist.Background:I have overheard a conversation between some "makers", say some young engineers who are working on some innovative and interesting IoT-projects. But they sounded really frustrated as their hardware suffered from some unreliable prototype build, primary caused by intermittent contacts, things went defunct when they have probed some test points etc.And so we had a chat. I have encouraged them to use perfboards with soldered-down components instead of their solderless prototype boards. I also recommended them to watch some of the well-made tutorials about alternative methods for circuit prototyping on YouTube. Such as Alan's excellent one here:.Of course, a nice custom-PCB cannot be beaten - but a simple circuit made from a perfboard can be made in a very time-efficient manner.And I did the same thing earlier this week when I was testing an I2C-controlled 16-bit DAC from TI; that's an olderDAC8571type. This DAC comes in a 8-lead MSOP package, so I have soldered it on a DIP adapter. I had put it into a solderless prototype board first. But as soon as the number of required connections increased, this setup became unreliable and inconvenient to use when probing.This simple circuit requires an I2C connection to a Totalphase I2C-host adapter, an external analogue probe for the DAC output, two digital probes, an optional LED with a current-limiting resistor, two I2C-pullups...So, very soon I have turned to an inexpensive perfboard as a quick and easy alternative to the solderless prototype board. I have soldered the components down, added a jumper for the LED, a large ground "hook" and a Si-diode to protect it against reverse polarity - voilá, it works like a charm. Some 30 minutes well spent.The resulting perfboard does not allow for any performance testing, of course - but as long as one is aware of its limit, it is a much better alternative to the solderless proto board as mentioned... The I2C connection works reliably even at 1 MHz and it is mechanically significantly more robust. And probing works reliablyCheers,THDplusN_bad

author: jpanhalt
author_rank: Super Contributor
timestamp: March 18, 2022, 09:22:04 pm
content: 1) "Perf" boards with all kinds of connection designs are widely available. Some even emulate the contact design of solderless boards.2) Eagle, and I suspect any decent ECAD can use a perfboard design and provide schematic capture plus allow easy re-routing.3) In the last 10 years, I have used solderless breadboards rarely, and then only to connect a couple of things temporarily, like an LED to a current limiting resistor to trace a circuit..

author: Gyro
author_rank: Super Contributor
timestamp: March 18, 2022, 09:44:35 pm
content: It's worth remembering that, in addition to using the readily available SMD IC adaptor PCBs, SMD passives, SOT23 transistors etc. can also easily be bridged between the pads.

author: tggzzz
author_rank: Super Contributor
timestamp: March 18, 2022, 09:44:50 pm
content: There are many other techniques that are better than solderless breadboards. I've listed some here:https://entertaininghacks.wordpress.com/2020/07/22/prototyping-circuits-easy-cheap-fast-reliable-techniques/I've taught the better techniques to beginners; they were successful, and appreciated the benefits.

author: Benta
author_rank: Super Contributor
timestamp: March 18, 2022, 09:46:50 pm
content: I've never used solderless breadboards (perhaps once in my youth).They simply introduce too many errors (as seen on this site).

author: oz2cpu
author_rank: Frequent Contributor
timestamp: March 18, 2022, 10:40:44 pm
content: i make almost anything like this.. it is fast and easyhttps://youtu.be/WPruls5KfbQ

author: BrokenYugo
author_rank: Super Contributor
timestamp: March 18, 2022, 11:30:04 pm
content: Only thing I don't like about the plated through hole perf boards is it isn't the easiest to desolder/rework.I've not yet tried it but suspect I'd like strip board/veroboard better.Also don't forget you can dead bug on anything solder sticks to, old Altoids mint tins and similar work well and double as a small project box.

author: cdev
author_rank: Super Contributor
timestamp: March 18, 2022, 11:45:50 pm
content: I like this "Manhattan" type prototyping but really hate the smell of superglue when it gets heated up by a soldering iron. Also its not that reliable at sticking.Somebody could make a lot of sellable items to serve the prototyping market. I can think of a bunch I would buy. (if they were available)

author: themadhippy
author_rank: Super Contributor
timestamp: March 19, 2022, 12:10:02 am
content: As a youngster almost all my circuits were built on breadboard as components were expensive,a 555 or 741 was a weeks pocket money so the ability to reuse them was essential until the desoldering without destroying skill developed.Nowadays its good ole vero type board especially this variant with 2 power buseshttps://cpc.farnell.com/multicomp/mc01010/circuit-board-95x72-780-ic-board/dp/PC01289

author: james_s
author_rank: Super Contributor
timestamp: March 19, 2022, 12:25:11 am
content: I use all of these construction techniques. Solderless breadboards have significant advantages when you want to reuse the components, and they are nice for stuff like microcontrollers that you want to plug in and remove easily. Deadbug on blank copperclad is a nice technique though, especially for anything RF.

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2022, 12:32:22 am
content: Quote from: themadhippy on March 19, 2022, 12:10:02 amI salvaged most of the components I used, from old boards bought in Lisle St, Tottenham Ct Rd, etc. ICs were put in sockets, which could be soldered safely.I find too much planning is needed on vero stripboard. For ready-made boards I prefer"uncommitted manhattan", with a solid ground plane on the reverse, and manyunplatedholes.

author: ledtester
author_rank: Super Contributor
timestamp: March 19, 2022, 01:22:34 am
content: The thing is... almost any circuit you spend time building is worth keeping around.

author: BrokenYugo
author_rank: Super Contributor
timestamp: March 19, 2022, 03:40:48 am
content: Quote from: cdev on March 18, 2022, 11:45:50 pmGrind up an island cutter?http://www.gqrp.com/padcutter.pdf

author: sleemanj
author_rank: Super Contributor
timestamp: March 19, 2022, 03:46:04 am
content: Breadboard style prototype PCBs give you the best of both worlds IMHO, I usually use the typical cheap single sided ones when I need to quickly knock something togethor...

author: fourfathom
author_rank: Super Contributor
timestamp: March 19, 2022, 04:18:02 am
content: For making isolated pads on copper-clad board you can also use diamond-coated hole drill bits. They come in all sizes:https://www.amazon.com/gp/product/B073LW7B7K/The pads you can reasonably make with these are too big for, say, a 0.1" DIP pinout, but they work well for larger components.Me, for RF hand-prototyping I use a woodworking "gouge chisel" on double-sided PCB. I don't have this particular one, but it's close:https://www.amazon.com/Mikisyo-Power-carving-chisel-triangular/dp/B003PFUTWGMake sure to be careful, or at least keep some bandages handy. Blood is a poor dielectric.

author: BrokenYugo
author_rank: Super Contributor
timestamp: March 19, 2022, 04:27:01 am
content: For hand gouging out islands/tracks I've seen it suggested to regrind an exacto blade (or other fairly thin tool steel, a single edge razor blade might work well) into a hooked cutter you pull to cut. Probably a bit safer than a woodworking gouge.The trouble with the diamond drills is they're centerless, so I would think you could only use them in a drill press with the board clamped down.

author: james_s
author_rank: Super Contributor
timestamp: March 19, 2022, 07:38:18 am
content: Quote from: ledtester on March 19, 2022, 01:22:34 amI build lots of prototypes that are of no real value. Usually they're portions of circuits that I'm experimenting with, or one off development boards for testing a part.

author: jpanhalt
author_rank: Super Contributor
timestamp: March 19, 2022, 08:04:56 am
content: @BrokenYugoA generic name for that type of drill is "brad point." If they don't work out of the box, they are easily dressed to work better.I have a miniature table saw, which is great for cutting rectangular/square islands. Use a carbide tipped blade.

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2022, 10:57:21 am
content: Quote from: sleemanj on March 19, 2022, 03:46:04 amDisadvantages: no ground plane, difficult for SMD components.

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2022, 11:06:00 am
content: Quote from: BrokenYugo on March 19, 2022, 04:27:01 amI like spherical dental burs in a dremel. They are very controllable, provided you use a light touch.

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2022, 11:07:26 am
content: Quote from: james_s on March 19, 2022, 07:38:18 amRat's nest, as popularised by Widlar and Pease, is a workable technique for that.

author: Gyro
author_rank: Super Contributor
timestamp: March 19, 2022, 11:25:35 am
content: Quote from: tggzzz on March 19, 2022, 12:32:22 amAh, Lisle Street. Happy memories!

author: themadhippy
author_rank: Super Contributor
timestamp: March 19, 2022, 11:58:57 am
content: All this bodging with dentists bits and dimonds to cut the perf board tracks,use the proper tool for the job,a spot face cutter,Or a 3.5mm drill bit works just as well and is a dam sight cheaper

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2022, 12:11:28 pm
content: Quote from: themadhippy on March 19, 2022, 11:58:57 amYou wouldn't use a bur for that.Use the combination of techniques that makes sense. A spot face cutter or drill couldn't make these:

author: Ian.M
author_rank: Super Contributor
timestamp: March 19, 2022, 02:46:13 pm
content: Quote from: themadhippy on March 19, 2022, 11:58:57 amWhat, on Tri-Pad board? That's already got the tracks cut into convenient groups of three pads so you only ever need to do spot cuts if you need more creepage distance, though IMHO if you are stripping copper for creepage, an Xacto knife + heating the unwanted pad with a hot iron to weaken its bond to the substrate does a better job with a smoother surface that's easier to keep free from conductive contaminates.

author: Buriedcode
author_rank: Super Contributor
timestamp: March 19, 2022, 10:56:00 pm
content: Whilst there are exceptions - notable higher frequency stuff, switchers that require short loops and large ground pours etc.., I pretty much do everything with cheap SRBP stripboard, and SMD adapters when needed. SMT passives work fine (0603/0805) between tracks, and the material is so easy to cut/shape/drill so it only needs to be scored. You can get quite high density with it if you don't have to abide by having all top links being "X" with the tracks being "Y".Solderless BB's have their place, but for quick and simple things like logic, low frequency analogue and the like. I have so many "sub boards" like breakouts and SMPS modules that the solderless breadboards are mostly for just connecting modules. Then it moves to stripboard, then its straight to PCB fab.

author: THDplusN_bad
author_rank: Regular Contributor
timestamp: March 22, 2022, 06:56:44 pm
content: Quote from: tggzzz on March 18, 2022, 09:44:50 pmThanks for the reference - you have provided a very nice and useful summary of several common and not-so-common techniques. Some nice boards you had designed.I sometimes also use the "Manhattan style" building technique for simple circuits. Example attached (this is just a standard emitter-follower amplifier good for about 12 MHz square wave signals with moderate tr/tf etc.). I have cut a standard wood drill for this per the attached photo. This shall only have only one "tooth" to cut the copper islands.I totally agree that a drill press and a solid fixture are needed for the safe handling of this technique, as the eccentric forces can build-up easily and one absolutely does not want to have the PCB start spinning 'round.Side note: I have found PCB material to be pretty abrasive, so I use dedicated tools for PCB work and always have the shop vac running to clean the workplace from particles.Cheers,THDplusN_bad

author: tggzzz
author_rank: Super Contributor
timestamp: March 22, 2022, 07:57:05 pm
content: Quote from: THDplusN_bad on March 22, 2022, 06:56:44 pmI'm glad you found them useful, but I have to point out the examples aren't my circuits. I've merelyresearchedstolen pictures from the web

author: freda
author_rank: Regular Contributor
timestamp: March 23, 2022, 05:15:09 am
content: How about make your own boards..........." alt="" class="bbc_img" />" alt="" class="bbc_img" />I normally have quite enough solder-less board space, but I still op to whip up a soldered sub-circuitbecause its a lot more reliable and reduces rats-nest (after of course prototype on the socket board)" alt="" class="bbc_img" />It even works out for rather permanent one-offs....Now thats been in my car rear door for many years and still going...........And what is it??cardboard!!Well, to be more specific it is juice carton cardboard.So I've used 2l juice cartons cut up the sides to squares andglue 2 sheets together with woodworking glue (PVA exterior), then between some disposable sheets (magazinesheets) and sit a stack of books on top. I usually leave for a week or more like that.2lt juice cartons are getting a bit hard to find now, everything is plastic!though I got now 1lt milk cartons, haven't tried yet, but I guess it would need 3 sheets glued together.The cartons with Aluminized interior are no good (obviously)Then you just need a sharp pick tool to punch holes by hand (no laborious drilling, yippie!!!).I still use cad for schematic and layout, and its just convenient for juggling where components sitbefore committing, just to record history.After doing many you do need some record of these one offs.Of course I still use perf board ...because pots and switches and so on need some stiffness in the mount.[eh,i'm still working out image use on this forum, ....wanted image inline...preview doesn't show images?

author: eugene
author_rank: Frequent Contributor
timestamp: March 23, 2022, 01:45:10 pm
content: You guys must enjoy the process. I like crafting all sorts of things, not just electronic, but I don't find satisfaction grinding away portions of copper clad board to make a circuit board.The fastest and most delicate signals I generally deal with are SPI and I2C. For that, I have had no problems with solderless breadboards. I can usually put something together from parts I have around in just a few minutes. Much less time than soldering perfbord, never mind grinding away at copper clad (especially after fixing the inevitable mistakes.) When I'm done I can design a PCB and send the Gerbers to a fab house. Then disassemble the solderless breadboard in a matter of seconds and put all the components away for another time.As it happens, I do enjoy the process of laying out PCB's.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 23, 2022, 04:07:30 pm
content: Me, be prototypin' likeFWIW, my process is, for builds up to say 50 components: copper clad is worthwhile. I don't use grinders, but a utility blade with a sharp knife. Abrasion resistance is mandatory, get the bimetal kind. You can get very fine lines this way, I've even done TSSOP (0.65mm pitch) before, though it's obviously quite a pain and only acceptable when I need the thing now, and don't have a breakout board handy.So, more than 50 components in total, or making more than one or two of something -- probably gonna sit down, layout and order it. I've done one or two in the low hundred I think; hey, it was a slow week.I use a mix of SMT and THT parts. The latter can be placed anywhere, and fly over top as jumpers. SMT chips, SOD, SOT and SOIC are easy to use. I also use DIP with the leads bent out for gull-wing soldering.I tend to cut sheets with shears rather than saws, though this gives a rough edge. If I need a smooth edge, sawing helps for starters, and wet-dry sandpaper does a good job cleaning it up, and also for tweaking things to size, say if I'm making a closure or mechanism out of the stuff too.This is probably much more work than it's worth -- so I'll leave that acknowledgement here -- but it's nice results for not having to cut up heavy sheets of metal, or cut holes in a project box. This assembly works with the main board sliding into slots in the two end shells, and the one screw hole in the small cap piece holds the entire thing together. It takes a bit of cleverness to figure out what sequence of pieces to cut and assemble, and how to register them together so you're getting a tight fit.Most of the time, when I build assemblies like these, it's something that I started as a prototype (probably on the solderless breadboard, in part or whole), and want to keep using. It's a one-off, maybe I'll write down the schematic in Altium, maybe I'll even do a little PCB layout to resolve tight sections, but no point in getting PCBs made, it'll take as long to clean up and finish the PCB design as to cut in and do it -- granted, give or take some slack related to the ~2wk turn of protoboards."In part or whole" is a good point. Often there are sections that can't be breadboarded: switching supplies and radio circuits for example. Identify the core features of the circuit, and prioritize them. An inverter circuit might be challenging to breadboard, but its controls are perfectly fine. Isolate the core inverter loop on a protoboard, then take its control/sense leads back to the breadboard. Or for radio stuff, direct signals gotta be on the proto, but you can take power, bias and baseband signals to the breadboard, maybe IF as well.The deciding factor is impedance and frequency. At low, say audio frequencies, it hardly matters. For impedances of, say, fractional ohms to Mohms, solderless breadboards are fine. You won't notice a thing, go nuts, have fun. As frequency goes up, impedance becomes more critical: the closer to middling impedances your circuit runs at, the easier you'll have getting high bandwidth through it. So a switching circuit doing say 12V 5A at 500kHz is pushing it (12V/5A = 2.4 ohms, quite a low impedance; the switching frequency implies harmonics in the fractional to low 100s MHz, quite a challenge to pull off on solderless breadboard!), but an RF amp at say 10MHz and 24V 0.5A (~50 ohm) isn't such a challenge (indeed, that's just an IRF510 biased up, nothing special needed -- the transistor is worse by itself, than the breadboard around it!).Don't ignore harmonics. It's not the clock frequency, it's the risetime that kills.Which...Quote from: eugene on March 23, 2022, 01:45:10 pm...Keep in mind that, while clock rates can be modest, it's the edges that kill. Middle to low end MCUs can have risetimes of mere nanoseconds -- more than enough to cause trouble on a breadboard with ~20cm fly leads, say. Consider using twisted pair or ribbon cable (alternating signals and grounds) for connections between boards, long connections over the breadboard, etc. Or terminating pin drivers with a series resistor or ferrite bead.Just as a simple example, I'd done this with an ATMEGA32 into an ADC/DAC pair I breadboarded on a separate copper clad piece. (See again the application of giving priority to sensitive signals.) With fly leads, I was getting extra clocks -- the ringing was quite obvious even on the scope. Ferrite bead at the pin driver, good to go. Uh, I forget if I also added extra ground wires, but yeah, that helps too like I said.So, I2C is pretty easy, it's not driven very hard -- fall times can be pretty sharp though, so keep that in mind, but risetime is just the RC time constant, pretty boring stuff. The major downside to I2C is, it's extremely noise sensitive -- the bus is fairly high impedance, and the protocol has NO tolerance for noise. So it's laughably unprepared for a real-world environment, with (unshielded) connectors and board-to-board wiring. For just prototyping, it's fine: your noise environment is (hopefully?) on the quiet side, faults/errors are tolerable, and you're just testing things out, not going for reliability or anything.So, with such precautions in place -- MCU logic stuff is indeed quite solderlessly breadboardable. Without such precautions, you may find spooky behavior, skipped/doubled bits (like SPI data that's clearly been displaced), uh oscillation in other gates/drivers, etc.Even with ye olde logic families (74HC, or LS even, for that matter), edge rates can be fast enough to be an occasional problem on the breadboard -- especially annoying if you're doing something big like a CPU with parallel address and data buses, various peripherals, etc. And especially hard to troubleshoot -- even if you have the tools and techniques -- just because, without that ground plane to work against, there's no sense to make of it, it's just a nest of wires and buses, high frequency noise goes everywhere. I did one of these back in college (https://www.seventransistorlabs.com/Images/Z80_Timer2.jpg) and it worked well for the most part, but would randomly fail after I added a LFSR (a random number generator routine) to the program.Tim