A Printed Circuit Board (PCB) electrically connects electronic components by making conductive pathways, pads and other elements etched from a copper sheet, which is laminated onto a non-conducting substrate. The PCB fabrication process involves several steps such as etching, drilling, plating, solder resist and testing. In manufacturing our boards, we always use high-class materials to guarantee that the finished products meet your company’s specifications.
Advantages Of PCB Over Bread Board
• Our PCBs have far higher density than regular bread boards.
• The design of a PCB is more reliable than that of a bread board. The circuit will not crumble and it looks neater without wires popping out from every corner.
• With a PCB, you can precisely control the circuit component you’re using, and you can easily incorporate odd-shaped components. This is difficult to do if you’re using a bread board.
• Production of huge volumes of PCBs is less expensive and you can employ automated machines for the soldering to make the entire process easier and less time-consuming.
After deciding on the type of electronic circuit that you wish to build on the board, you will have to create a board design on a PC prior to the actual PCB fabrication. There are several software that you can use to help you with the designing process. It is important to note that since you’re looking at the board from the top view, all elements of the design must be done in reverse. If you’re designing a circuit, the layout on the board must have a 360-degree flip.
After you’re done with the design, you will then have to print the layout you made, preferably with a laser printer. Be mindful of the type of printing paper you’re about to use. Although a bit costly, gloss transparent photo paper are considered the most appropriate for this process.
You also have to ensure that each component is properly fitted onto the print. You may first copy the print on an ordinary photo paper then lay all the components down. Make sure the size of your layout fits the size of the board. Use the highest resolution for the print and never use any color other than black. Increase color contrast and make sure that the actual print is darker and thicker. Once the print comes out, don’t take it right away. Wait until the ink completely dries out.
Leave some blank areas when cutting the layout. Place the layout on the board and apply heat and pressure by pressing a moderately hot iron box over it. After a few minutes, the layout will be attached to the paper and the board, and you will have to remove the paper so it gets attached to the board permanently. You can remove the paper by soaking it in water for 2-3 hours. Once taken out of water, you can use your finger to rub and remove all the remaining bits of paper off the board.
The etching process is a necessary step of PCB fabrication. This process is done to eliminate excess copper after putting on a mask, leaving behind only the required copper tracks.
All PCBs are built by affixing a layer of copper on top of the substrate. In some occasions, the copper can be bound on both sides. There are various etching methods that you can use, but the most popular is chemical etching, wherein you can use either hydrochloric acid or ferric chloride.
Attaching components onto the multi-layered board can only be accomplished by means of VIAS drilling. Small bits of drill made of tungsten are used during this process. To punch the through-holes, a dremel drill is usually used. However, for huge volume of board production, automated drilling equipment are more efficient.
Some parts of the board don’t allow soldering of components. This is usually the copper connections or parts where components are positioned. To solder the components on it, you need to plate the surface with conductors such as tin, nickel or gold.
Other parts where soldering is not allowed are those with solder resist substance. It’s chiefly a polymer covering that serves to prevent the solder from creating traces and shortcuts to other component leads.
The whole process of PCB fabrication will not be complete without testing the boards. We always test our PCBs for quality control prior to taking them out of the factory. We employ different testing methods, including CT scanning, Rigid-Needle Adaptor, Bed of Nails, and so on. All our tests essentially involve a computer program that will instruct electrical test units to apply a slight voltage to contact points, and attest that a particular voltage is present at its proper contact point.
Above are the basic steps to follow PCB fabrication. Depending on the type of device that we use, we also apply other steps, such as using SMT or Surface Mount Technology. This is to ensure that our clients get satisfied with our services.