In this article, I will go through the process of fabricating a Printed Circuit Board (PCB), with a focus on audio electronics in specific (that is, single sided PCBs using components with leads, because many guitar effects, amplifiers, synthesizers, etc. use this technology). A PCB is used to interconnect electronic devices which form a circuit. Other ways of making circuits include solderless prototyping boards (sometimes called breadboards), perf boards (a mix between proto-boards and PCBs) and I've even seen cardboard printouts where the leads are pushed through and soldered together on the back. Aside from these inefficient, prototype based methods; PCBs remain to be the best way to interconnect devices, no matter how big the system.
Here is what you will need to get started:
- Layout software or grid paper (Optional if you already have the layout). My favorite (FREE!) layout tool is Cadsoft Eagle. In the free version, you are limited to a 4x4" board space. Other good ones I've used are OrCAD and Mentor Graphics PADS (not free, $$$). Furthermore, back when I started doing layout, I used grid paper to draw out the traces like one big puzzle. Other CAD tools have grids and you can draw out traces the same way. You can even make your own library of resistor, capacitor, diode, transistor, and IC foot prints for all the parts commonly found in circuits.
- Photo-grade, laser printer paper. I use staples brand photo paper because it separates pretty easy. More on this in the Procedure section.
- Laser printer. I found my laser printer second hand. Nothing fancy is required, you just need a way to transfer black toner onto your photo paper. There are lots of print centers out there for your convenience as well. NOTE: Ink printers DO NOT work using this method of etching. You can follow a similar procedure using a very specific brand of blank overhead transparencies and printer/ ink types. "Press'n'peel Bule" is the preferred method for ink transfers.
- Sharpie permanent marker. Toner transfer is a little error prone. Use a sharpie to correct transfer mistakes.
- Blank copper board. Copper boards come in lots of thicknesses, weights, layers (almost always two sided for stock boards), and dimensions. You should always be sure of these four attributes when buying copper boards. I almost always go with 1/16" thick, 1oz. copper, and single sided board when building guitar effects. Board dimension is dependent on how big the layout is, how many boards you want to get out of a single panel, and how big your etch tank/ container is.
- Etch tank/ container. This is a critical component of making PCBs. You must find a DEDICATED container that is capable of withstanding an oxidation-reduction with moderately strong acids. Most polymer containers found in the common kitchen will suffice. Teflon is the best for etching. Shown below is my etch tank: cereal container with lid (~2 Qt., found at Walmart, Target, etc), a fish tank heater, and a fish tank bubbler (both found at pet stores of course, but I found mine second hand for free!). Just keep in mind that your container must be big enough to submerge your copper board.
- Etchant. Now you've entered into the world of chemistry (sorry, I didn't mean to bring back any nightmares). There are lots of liquid chemicals that can dissolve copper. The three most common types of hobby etchants are: Ferric Chloride, Ammonium Persulfate, and Hydrochloric Acid (HCl)/ Hydrogen Peroxide (base). The later mixture is the most common and easiest to get. The common name for Hydrochloric acid is Muriatic Acid, or pool acid. Hydrogen Peroxide is a disinfectant available at the grocery store in the brown, opaque bottles. For PCB etching, a common mixture is two parts Hydrogen Peroxide for every one part of HCl. Ferric Chloride and Ammonium Persulfate both come in powered and prepared liquid form, but you most likely have to special order them and the liquid form often carries extra fees (HAZMAT, etc.).
- Protective apparel; rubber gloves, apron, goggles. All etchants will irritate and/ or burn your skin and eyes. Safety first!
- Drill press. This is always the hardest part of the process to fulfill. Hopefully you or someone you know has a drill press and the worst of your problems are finding the small drill bit for the pads. I've even seen battery powered hand drills turned into a make-shift drill press.
- Steel wool/ adhesive cleaner. Steel wool is a very handy cleaning material to have in general. I always have medium-coarse on hand. After etching, you have to clean off the toner from the pads (at least), but I usually clean it all off. Adhesive cleaner combined with steel wool gives the best results. Both can be found at Home Depot.
- Clothing Iron. Not for clothes of course! This is used to melt the toner from your print out onto the copper board. The hot surface of the iron should be as flat as possible.
The information contained herein is made available to the public by "Stomp That Box.com" and "Marcus Young", content information may not reflect the realities of the actual project. The intent of the example is to assist an individual fabricating a Printed Circuit Board (PCB).
Neither "Stomp That Box.com" or "Marcus Young" nor any other agency or entities thereof, assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, product or process disclosed in these examples.
Reference herein to any specific commercial product, process or any agency entities the writers to have NO responsibility of any injury that could accure by the misuse of the chemicals or tools discussed in this article, proceed at your OWN risk!