Introduction: Fully 3D Printed Circuit Boards
When I first heard the name "Printed Circuit Board" I thought that there was a machine you could get that printed circuit boards. While such machinery does exist, it is reserved for use in large scale factories. The home-brew circuit board designer fabricates his or hers by designing it with software like Eagle CAD, and printing the traces out onto transfer or magazine paper. Then they must iron it on to copper coated boards and dunk it into etchant of ferric chloride or my personal favorite, cupric chloride (created from mixing muriatic acid to peroxide in a 1:2 ratio) and waiting for the copper not protected by the transfer paper to dissolve away, leaving only the traces. Then they must drill holes for components and solder them in. The entire process can take hours. This got me thinking, what if there was a way for makers to prototype circuit boards cheaply but without having to use "mildly" dangerous chemicals to do it. That's when I realized that it might be possible to "print" a circuit board utilizing conductive filament and a 3D printer. And as it turns out, it is possible. In this Instructable I hope to show you how to print your own circuit boards with a 3D printer. But before we can 3D print a circuit board, we have to know what a circuit board is.
Step 1: What Is a Printed Circuit Board
Before we try and 3D print a circuit board, let's get more familiar with the terms and components we will see during this Instructable. Expand the images and look at the notes to get a more profound view of the circuit board shown here. The circuit board shown is a disposable camera circuit board. I picked these pictures because a disposable camera circuit board is usually quite simple and there were high-def pictures of the front and back of the board.
Image source: http://projects.m-qp-m.us/insect-camera/the-spinni...
Components: The things that do the stuff to put it very simply. Components can be capacitors, transistors, resistors, transformers, diodes, LED's, switches, anything that affects the current in a purposeful way is a component. Components can be surface or through-hole mounted. Surface mounted components are mounted onto the surface of a PCB. They are quite small and can be hard to work with. Through-hole components have pieces of wire called leads sticking out of them, these leads are then stuck through holes drilled in the circuit board and connected to conductive traces on the other side.
Traces: These conductive areas on the circuit board are made of copper and connect components together. Component leads are stuck through drill holes in the board and soldered to the traces.
Solder: Made up of lead or a tin-silver alloy, this conductive metal is melted with a soldering iron and bonds components to their traces.
So, to make a 3D printed circuit board, we are going to need equivalents of: components, traces, non-conductive solid material, solder, and something to melt that solder with. In the next step I will show you how and where to get the materials and tools you need for the circuit board.
Step 2: Materials and Tools
Alright, let's look at the materials and tools we need. We need the equivalents of the circuit board parts I enumerated in the last step. They were: components, traces, non-conductive solid material, solder, and something to melt that solder with. I will list the equivalents I used here.
For the Solder and Traces I used: Conductive PLA 3D printer filament. I bought it from Proto-pasta. Link to Product (Conductive PLA)
For a Soldering Iron I used: A 3D extruder pen. Mine is the Scribbler v3. There are many different types of these on the market, choose the one that suits your practical and financial needs well. Link to Product (3D Pen)Amazon Search for 3D pen (Contains Many Options)
For a Solid Non-Conductive Material I used white ABS filament. The stuff I used came with my printer but here's a helpful link. You can use any color you like, but because conductive filament is (almost?) always black, I recommend a different color for your non-conductive elements, so you can tell them apart.
Now, onto the tools.
You need a 3D printer capable of printing with two different colors. This doesn't have to be a duel extruder printer, but it makes it much easier by having one. The printer I use is the FlashForge Creator Pro. It has been a great printer so far and I highly recommend it.
You need a digital caliper or ruler to measure the distance between component leads.
You also need access to 3D modeling software. I used tinkercad to make my circuit boards, but you can use any software you like. If you know how to 3D model well, you can easily replicate anything I do in tinkercad in your favorite program. If you do not, tinkercad is a great place to start.
If you don't have any components lying about, you need the equipment listed here.
I used a Used Disposable Camera to extract components from. These are good because if you play your cards right, you can pick many of them up for free from a local drug store like Walgreen's. Here's a link to an instructable detailing what to do to get these cameras, and what you can do with the parts inside.
NOTE: There is a very large capacitor inside that will give you a painful shock if you touch both leads. Make it safe by touching both leads with your least favorite screwdriver. This will make the circuit board safe to use without having to worry about getting a shock.
You need an actual Soldering Iron to desolder the components in the camera's flash.
You need desoldering tape or a desoldering pump. I prefer the pump method because it's much faster.
You need a flat head screwdriver to pry apart the camera's case. Be careful not to damage the electric components inside.
In the next step we get to 3D modeling, and how to use tinkercad to create traces.
P.S. I know I used conductive PLA with non-conductive ABS. This was a large problem for me. The conductive PLA has less resistance than the conductive ABS I found. Just use the conductive version of your base material and you'll be fine.
Step 3: 3D Design
First, go to tinkercad.com and make an Autodesk account or log in with an existing one. Click on the button in the top left corner that says "Learn," scroll down to Lessons and complete the first seven. Then, think about what you want your circuit board to be, plan out the design on a piece of paper or have it well remembered. Here are the steps for creating a successful circuit board.
1. Create a box the size you want your circuit board to be. Then set its height to 4 mm. It should look something like the first image.
2. Measure out the maximum extension of your component leads. Make sure that your circuit board holes for that component are not too close together or too far apart.
3. Drag out more boxes and set their height to 1 mm. Make them as long as you want and place them slightly above your original box in the way you want them. These are your traces. Add cylindrical holes that have a diameter of 2 mm and a height of enough to stick through both sides of the traces where your component leads will go. Make sure everything you want connected is connected. You can remove the original box if it's getting in the way, just remember the dimensions.
4. Group all your traces together. You should know how to do this. DO NOT group the cylindrical holes with the traces. It should look something like the second image but you may have kept the box.
5. Add the original box back if you removed it.
6. Drag your grouped traces into the original box until the top is flush. If you used different colors (you should have), you will get a strange glitch effect as the two objects are on the same level inside each other. It should look a bit like the third image. If you don't see it at first, move the camera around, you'll see it.
7. Then, turn the grouped traces into a hole. Group the hole with the box.
8. Drag the cylindrical holes that were not grouped straight down without moving them to one side or the other. Then group all the holes with the box-trace group. It should look a bit like the fourth image.
9. Click "Design" in the upper left corner then click download for 3D printing. Choose STL, If you didn't rename the project it will save as a random name. Go into its folder and rename it to something you'll remember like "circuit_board_base".
10. Click Ungroup and delete the original box. If your cylindrical holes aren't long enough, extend them or move them so there are holes in the traces. Group the holes with the traces. It should look something like the fifth image. Then download for 3D printing as an STL file again. Make sure to rename it something you can remember like "circuit_board_traces."
You are now done with your 3D design. Now you must slice it and export for 3D printing. You should take a break here and grab something to eat or drink.
P.S. I uploaded my base and trace STL files if anyone wants them. The one component required is a transistor.
Step 4: Slicing
The slicer that I use is called Simplify3D. I like it very much. This Instructable is meant for dual extruder printers, if you have a single extruder printer, then... good luck. Here's a link to help you out though,
It's going to be really difficult and you'll need a fundamental understanding of gcode, so... Take this link too.
Alright, now that we have that out of the way, we can move on. You're going to want to push both STL files together in the slicer. Now, luckily for people using Simplify3D, they have a great guide on that here:
Those who use Makerware have a guide here:
Now, for Simplify3D users you must set your 3D printer model in the process settings. Just pick from the list. Image one shows this. You must also choose your material from the four options provided. Image two shows this. After slicing, click "Prepare to Print!" and select both processes. Then export to an SD card or USB drive, or connect directly to your printer and then print.
*1 to 2 hours later*
In the next step, we will add in our components, and finish up our circuit board.
P.S.: Cut two feet off of the conductive filament spool before loading in your printer63 for use in the 3D pen.
Step 5: Getting Components
This is kind-of a bonus step. If you do not have any components you can use the disposable camera you may have picked up. Remove the front cover with a screwdriver. Then, locate the flash capacitor. It is the big black cylinder, tap your least favorite screwdriver between the two leads coming out of it to discharge it making it safe. Desolder all the components you want and use them in your circuit boards.
Step 6: Attaching Components
Attaching components with the 3D pen is quite simple. I will enumerate the steps for you here.
1. Push your component leads through the holes that you have made.
2. Power on and heat up the pen to the correct temperature for your material.
3. Add the conductive filament to the pen
4. For through-hole components extrude a moderate amount a filament around the joint between the component lead and the conductive trace. If the joint fails and doesn't stick to the board or the lead, extrude some more and use the tip to spread it around. A friend and I had a heated discussion over the phone on what I should call this process. We eventually agreed on flodering, short for filament-soldering. (It's supposed to be a silly name)
5. Find something to use your circuit board with.
Next Step: Testing your creation
Step 7: Testing Your Creation
As you may know, my creation was a transistor breakout board. Not knowing what to do with it, I searched for interesting circuits and I came across something called a transistor tester. I desoldered an LED from the disposable camera and extruded some conductive filament onto a piece of paper. The transistor is of the NPN variety, so I extruded a circuit that lit up an LED when the base and the collector were connected by a conductive material like a finger or a paperclip. I connected the breakout board to the extruded circuit with wire. Now, you might be wondering why there is a low voltage LED hooked up to a 9v battery and the LED is not melting. When designing 3D printed circuits, you must think about the amount of electrical resistance the filament has. All the conductive filament brands have different amounts of resistance. The resistance of the Proto-pasta brand that I use is 30 ohms per cm.
Thank you so much for reading my Instructable, please vote for it in the 3D Hubs 3D printing contest. If I win I will use the 3D printer to help teach kids at a local school about 3D modeling and CAD. But, the real message I want to get out there: I really want to see what you guys and gals can do with this idea. The idea of embedding an Arduino mini in a 3D printed cube and having an pulsing LED cube of doom sounds awesome to me. A 3D circuit board isn't too far away as the advances in conductive filament technology brings the electrical resistance further and further down. As for now, 6/19/15, 3D printed circuit boards in this form at least are simply a proof of concept.
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