Tags: Pcb assembly, Pcb fabrication, Pcbnet, pcbnet.com, Printed circuit board, Printed circuit boards
By now, you have probably designed the circuit using computer-aided simulations that allow the circuit to work great. The only thing to do now is to create a printed circuit board so you can actually see it working. Regardless of whether your circuit is for a school project or an important component of an electronic product that you are building for your company, transforming it on a PCB will improve its look and give you an idea of how the completed product will look like.
There are currently four methods to print a circuit board – acid etching method, UV etching method, mechanical etching (also known as routing method), and laser etching method. This article focuses on the acid etching method to produce a printed circuit board easily.
It is important to keep in mind that the acid etching method needs extreme safety precautions. You also need several materials and the process is quite slow compared to other methods. The quality of the board may vary depending on the materials you use but in general, it is a great method for basic to intermediate level of circuits. If your circuits have tiny wires and more close wiring, the acid-etching method is recommended.
The first thing you need to do is to create the layout of the printed circuit board. This is normally done by transforming the schematic diagram of the circuit into a PCB layout through computer software. There are several PCB layout software available and it is best to choose open source software packages.
Also, make certain that you have all the materials you need. Next, draw the circuit layout on the copper coated board, which is only applicable for acid etching and UV etching method. In etching the board, you should look for the details sections on how to do it. This process eliminates any unnecessary copper from the board that leaves the final circuit’s wiring.
In drilling mount points, you can use custom machines designed for creating printed circuit boards. However, with some changes, a regular drilling machine can do the job especially if you are working at home.
In the acid etching method, you need to choose your etching acid. A common choice is ferric chloride, but you can also use ammonium persulfate crystals and other acid solutions. Regardless of your choice of the chemical etchant, the solution will always be a dangerous material. Hence, aside from following common safety precautions, you must always read and adhere to added safety precautions when using the acid.
For acid etching, you need to have a layout for the circuitry using a material that is resistant to the acid. There are special markers available for this particular purpose if you want to draw the printed circuit board manually. However, this is not suitable for medium to large circuits. Printer ink is commonly used to print the layout on a glossy paper. You must make certain that the circuit is mirrored before you do this. It is noted that most PCB layout software have this as an option when you need to print the schematics. Also take note that this only works on laser printers.
Then, place the glossy side with the printed layout on it facing the board. Iron the paper using a flat iron depending on the type of paper and ink you use. Dip the paper and the board in hot water for several minutes up to 8 to 10 minutes. Then peel off the paper.
Make sure that you read the instructions first before you prepare the acid solution. For instance, some crystallized acids need to be dissolved in hot water while other acid solutions are ready to use. You can submerge the board in the acid and make sure to stir it every three to five minutes.
Take out the board and wash it in running water until all the unneeded copper fall away from the board.