If you’re ready to finalize a breadboarded circuit, but not quite ready to create a printed circuit board, then your next step is protoboard. There are multiple varieties of prototyping board, but the two most common are referred to as perf board and stripboard. Both are made from a flat sheet of resin with a grid of holes drilled in them, however the conductive copper on the underside is different.
Perf Board
When most people talk about perf board, they are referring to the ever-popular “pad-per-hole” type of protoboard.
As you might suspect, each hole is surrounded by a copper pad. Connections are typically made by either bridging solder from pad to pad, or by running wires (or the bent leads of the components) from pad to pad.
Wires that jump off of the board are susceptible to being pulled, which can easily break the brittle solder joint. For added strength, it’s a good idea to first run wires from above through a hole in the board so that any stress on the wire isn’t put directly on the solder joint.
Stripboard
On stripboard there are parallel strips of copper that run the length of the board, connecting the holes together. These strips serve to connect multiple components together without wire, and can be separated, as pictured, into smaller segments with a few twists of a drill bit (see “Breaking Stripboard Traces” below). With some clever component positioning and strategic cutting, this can eliminate a lot of wiring on the underside of the board, and works great for simple circuits.
Breadboard to Stripboard
If you have a circuit prototyped on breadboard, you can easily transfer the same component layout to stripboard. You can buy stripboard with strips of copper in the same orientation as breadboard, or you can break the long copper strips down the middle into two strips. It’s a quick way to make a temporary circuit more permanent.
Planning
Standoffs are often overlooked, but they are a very useful way to mount your protoboard inside a case and make your project look a bit more professional. Standoffs are also vital when you are mounting your board in a metal enclosure, as you don’t want the component pins to short out on the enclosure.
If you’ve never created a complex circuit on protoboard, it can seem a little daunting. Thankfully, there are a couple of ways to lay out your design before you get started, which will make the build a lot easier.
The low-tech way to plan out protoboard circuits is with graph paper. Draw the outlines of your components where you’d like to place them on the protoboard, with the pins drawn on the intersections of the lines. Each line intersection is considered a hole. After “placing” your components, draw your connections along the lines between the components. For a tidy design, try to draw your lines straight or at 45º or 90º angles. If you need to use a jumper wire, draw it in with a different color so that it stands out. If you’re using stripboard, draw circles to denote where you will break the strip.
A more modern way to plan out protoboards is with software. There are a number of different board-planning applications, but we highly recommend Fritzing, which allows you to lay out circuits on both perf board and stripboard. It’s also a free download and runs on Windows, Mac OS X, and Linux!
Cutting Protoboard
Most protoboard is made out of paper laminated with phenolic resin. This material is great at resisting the heat required for soldering, but it can be difficult to cut without cracking it. Boards can be cut with traditional blade tools like a band saw or scroll saw, but it is often easier to use the score-and-snap method. Using a straightedge as a guide, score both sides of the board with a sharp knife, then place the board on the edge of the table and snap it along the marks. If you make the score marks through the center of a line of holes, there will be less material to snap, and you’ll have better luck avoiding cracking.
Breaking Stripboard Traces
An important part of using stripboard is strategically dividing up the strips of copper on the bottom to separate connections. While there are fancy purpose-made tools to break these connections, you can easily use a 4mm (or 5/16″) drill bit just as well. Place the drill bit tip into the hole where you want to break the connection, and twist until the copper is cut away completely. You have just turned one strip into two separate ones!
4 thoughts on “How and When to Use Protoboard”
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Rather than score n snap I like this thing for cutting PCBs. http://www.harborfreight.com/catalogsearch/result?q=mighty+mite. It’s a fairly weak saw but with the diamond blade it cuts through PCBs like butter. I like to clamp a carpenter’s square on the bed to use as a guide. This way I can make prefectly straight cuts with good 90degree corners.
I’m not a fan of protoboard. It’s a lot of work. The second copy takes just as long as the first to build. I will concede, however, that protoboard is the least expensive way of building ONE of something, if you want it to be reliable and look fairly finished.
If there’s any chance at all that I will want TWO of something, I will go to ExpressPCB. It allows me to build more compactly (using SMT parts), provides me with as many boards as I want for the same amount of design effort, and assembly is simple — just solder the parts on. I’ll get three boards for $49, and if I want bigger boards, or more of them, it’s hard to break $200. That sounds like a lot, but if your time is worth $20/hr, that’s only 10 hours of cutting traces, drilling holes, and soldering jumpers.
Worth a thought, anyway, before you break out the protoboard. I’ve convinced my boss here at work, that for quick prototyping with minimal overhead, ExpressPCB is the way to go. And the design tools are free, so you can get started right now. You will spend more time designing and less time building.
The article didn’t really deliver on “When to Use”. Which is why I visited it in the first place. I’m pretty well aware how to use these, but I’d much rather know when is it worth to go with breadboard, when to use protoboard, when to draw and etch your own, when to order one professionally made,
It’s worth noting that you can find special purpose protoboards with layouts for ICs or patterns of 2-contact and 3-contact solder pads, which can be helpful depending on what you are building.