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Analog Angle Blog

What’s Your Breadboard Look Like?

I was talking to a non-technical friend the other day, and mentioned something about breadboarding a circuit. He looked at me and asked, “What's that?” He had a point: “Breadboard” is one of those standard terms that engineers toss around casually, as both a noun and verb, as in, “The breadboard worked” or “I'm going to breadboard my circuit later.”

Unlike many phrases where the actual derivation is unclear, shrouded in mystery, or subject to different possibilities and myths, we know the origins of the term precisely. Today's breadboards, of course, are anything but a “bread board.”

Way back in the day, a circuit breadboard was literally just that: a wooden cutting board with nails as wiring posts; see here. Wires and components were connected to these nails, and that was the circuit, right out in the open, no secrets. This type of breadboard was even used for vacuum tube projects (watch out for the high voltages!) and some discrete transistor ones extending from DC to lower RF ranges.

Sometimes the nails were replaced with clips, such as Fahnestock clips (which you can still buy; see here) but I found those to be unreliable. In fact, I developed my early soldering skills by learning to solder my wires into these clips, thereby defeating the clip-in/clip-out functionality they offered but greatly enhancing their reliability.

Another breadboarding alternative for prototypes was wire-wrap; I wrote a short column about them for our sibling site, The Connecting Edge. You can read it here (it received many comments, by the way). There were also perforated PC-board material, with and without copper plating.

Then came the DIP (dual inline package) IC, which changed everything about breadboarding. While the DIP was certainly not compatible with a wooden board and nails, various solderless boards were developed for these packages, and they worked pretty well, such as the Global Specialities brand.

A classic solderless breadboard using DIP ICs and discrete components. (Source: Cornell University)

A classic solderless breadboard using DIP ICs and discrete components.
(Source: Cornell University)

But DIPs and discrete components are now a small and shrinking part of the circuit's bill of materials, of course. We have surface mount ICs and passives, and ICs with tens and even hundreds of contacts underneath their package. Sure, you can buy adapters and carriers to bring these contacts out to be visible and accessible, such as from Schmartboard, but that has a major effect on layout and signal integrity.

Reality is that for many of today's circuits, the only viable breadboard is an actual PC board. Clock rates are so high, bandwidths so wide, and there are so many signals to route here and there that only a genuine PC board can do it.

For awhile, many hobbyists were making their own with photoresist pens, acid etch baths, and more. But today's circuit density makes that sort of do-it-yourself PC board a real challenge — plus drilling any needed holes with precision placement is difficult.

Of course, a circuit board does not have to be the standard copper-etched type. You can also make your own with a milling process by using one of those excellent machines from LKPF Laser & Electronics. If you haven't seen these in action, they are amazing, and the density, precision, and speed of fabrication they achieve is impressive.

There's still a place for the original breadboard, I suppose, if you're doing a project such as LED lighting, where it's mostly power signals and routing. Beyond that, it's tough. One of my many unprovable hypotheses is that a major reason aspiring EEs (junior high school and up) don't get involved with circuit design — whether analog or digital — is that building a circuit with today's components is quite hard: either you have to figure out a way to use the tiny, surface-mount parts, or try to find DIP and non-SMT versions, and good luck on that. (And when you're done, you can't easily probe or change parts, anyway.)

Many years ago, I met the late Jim Williams in his lab at Linear Technology Corp., and he lamented the challenges of breadboarding with these super-tiny packages. Then he showed me his latest “breadboard.” It was a circuit in mid-air, like a spider's web, with components scattered like trapped flies among the strands. He said this allowed him to check out a circuit's basic concept, and the physical separation minimized crosstalk.

But he also admitted that when reduced to its PC board layout, things could go one of two ways. It could work better than the open-air circuit, due to better ground planes and shorter traces; or it could work worse, due to signal proximity, crosstalk, and noise. He said that even he just never knew what the result would be despite his experience and pretty good hunches.

What's your breadboard look like? How do you breadboard your circuits? Post pictures if possible.

15 comments on “What’s Your Breadboard Look Like?

  1. RedDerek
    May 27, 2013

    Brad, I provided you with some breadboard pics for a future blog. But if the circuit is just a few components, I will do the open-air connections. Quite challenging with the small surface mount components. I hardly use the proto board with the 100 mil holes since finding the through-hole components of newer devices is next to impossible; true I could have an adapter board to convert the surfacemount to a 100 mil through-hole. Otherwise, it is off to a circuit board that I would etch in the lab. With very careful review of each step, I have gotten down to 10 mil lines with 10 mil spacing using the toner-transfer method – requiring essentially one major chemical for the etching process and no darkroom for lighting photo resist/etch PCBs.

  2. Davidled
    May 27, 2013

    This blog reminded me of my breadboard.  Breadboard provided opportunity to let me design and build the circuit with components.  My experience for design was getting the gain by troubleshooting all kind of circuits.  But, today, breadboard is not used in a certain electronic area due to the slow response time among modules and chip package type. Second, it might be possible that engineering PC schematic tool replaces breadboard. For example, Labview of NI, Matlab, with updated Pspice is really beneficially for understanding the circuit behavior.  Anyway, breadboard is an indispensible tool for analogy designer as handwork project.

  3. David Maciel Silva
    May 27, 2013

    For items SMD boards are a good solution for adaptation:

    http://www.botnroll.com/product.php?id_product=426

    On the other hand we have trouble functioning because, faced with parasitic capacitances and bad contacts.

    For high frequency signals the breadboard is not indicated.

  4. Brad Albing
    May 28, 2013

    @DaeJ – yes, you can run a simulation and get a reasonable idea as to whether your circuit will work. But I think you get a far better idea by actually breadboarding the circuit and then experimenting with it. But as noted elsewhere, it's more difficult now with parts being available only as SMT devices. And the SMT-to-DIP adapters are expensive.

  5. Brad Albing
    May 28, 2013

    @Maciel – Parasitic capacitance and inductance will absolutely be trouble with this type of breadboard/prototype block, as will the occasional bad contact. Still, they are quite handy to put together a quick circuit for evaluation – as long as you are aware of the possible problems.

  6. Brad Albing
    May 28, 2013

    I've done that air-wired technique with the SM parts also (Jim Williams style). It works, but it's quite tediuos to build ckts that way.

  7. eafpres
    May 28, 2013

    @Bill–the PCB prototyping equipment like the LPKF is a mainstay in many antenna labs as well.  There are a lot of embedded antennas that are made out of 2-layer (copper both sides, dielectric in between) board and being able to go from CAD to a working part at high precision sure beats copper tape or scraping copper away with an X-acto knife.  We also found that it was really handy to have this capability if you needed to add some matching components at the feed of the antenna.  We always used SMT passives and had technicians who were really good at soldering them under a magnifyer lamp.

     

  8. Brad Albing
    May 28, 2013

    @eafpes – I've done the Xacto cuts on a PC board for RF ckts – even done stripline for microwave ckts. But it would be delightful to have one of those benchtop miling machines to make PC boards directly from the gerbil files. That plus the desktop 3D IC printer device….

  9. eafpres
    May 28, 2013

    Hmmm.  I like the idea of a 3D printer that can print ICs.  I wonder how far out that can be, with all the advances going on in 3D printing technology?

  10. Brad Albing
    May 28, 2013

    I'll say 5 years out and you'll be making ICs on a desktop 3D printer. Time to set up the office pool and write your initials on the day-month-year of your choice.

  11. TheMeasurementBlues
    May 29, 2013

    Brad,

    I like your idea about 3D printing in the future, but oh, the cost of the “ink.” It still seems impractical to make an IC at home using 3D printing given the materials and the resolution needed.

     

  12. Brad Albing
    May 29, 2013

    Clearly there are details to work out. But with the progress in other forms of 3D printing, I'll stick with my 5-year forecast.

  13. mtripoli
    May 29, 2013

    I've been breadboarding this way from before I can remember (wait. huh? what?) I've become so accustomed to doing it this way I can kind of “see through” what's real and what's contribution from things being all over the place. Of course, a good scope helps too. Here's a board that I'm working on; funny thing is, when it's on a PCB it will be about 3″x4″ in size. You can see my latest “score”; the HP DVM. I love the single dot led display:

    http://www.scarydesign.com/scary_lab/breadboard_00.jpg

    http://www.scarydesign.com/scary_lab/breadboard_01.jpg

    http://www.scarydesign.com/scary_lab/breadboard_02.jpg

    Some lamps and tubes:

    http://www.scarydesign.com/scary_lab/lightbulbs_tubes.jpg

    And the lab I call home (funny, no matter how big the room, I still wind up rotating around in the same 3'x3' space):

    http://www.scarydesign.com/scary_lab/scary_lab.jpg

    The microscope is for placing SMT devices. I built a reflow oven from a toaster oven and do 2mmx2mm IC's all the time. A steady hand, a good pair of tweezers and lots of coffee. I make my own adapters that convert any of the SMT into through hole when needed. Once you get the hang of it, it's really quite nice. 

    I wire wrapped my first computer; a 6800 with 1K of RAM. Programmed by flipping switches… I laugh when people complain about their 8-core blah blah blah being “too slow”. Show them a picture of a linear 5V, 20A supply some time.

     

     

     

     

     

  14. SunitaT
    May 31, 2013

    But with the progress in other forms of 3D printing, I'll stick with my 5-year forecast.

    @Brad, true 3D printing is rapidly evolving. Currently NASA is funding a 3D food printer with the aim of providing astronauts food during long-distance space travel. I wont be surprised if some organisation starts building the 3D printer using which we can make an IC at home.

  15. mtripoli
    June 1, 2013

    It is currently possible to print (using silkscreen and flexographic processes) electronic devices such as transistors and even simple circuits. It's a small step to doing this on “desktop” machines. However, to make the jump to actual multi (10's, 100's, etc.) transistors isn't remotely in the realm of “3D” printing. Open any basic text book on IC design and consider what it takes to make even the simplest device and the parameters that need to be controlled and you'll get an idea of why there are other things to tackle.

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