In 1936, the first printed circuit board (PCB) was created by Paul Eisle. But it wasn’t until the 1950s when the U.S. Defense industry began integrating PCBs in their bomb detonator systems that printed circuit boards found wide application. Printed circuit boards are utilized in almost all manufactured products like, automobiles, cellular telephones, pcs, among others.
An Overview from the PCB Fabrication Processes – PCBs are initially fabricated with the aid of two kinds of software. Computer Aided Design (CAD) software program is used to design the electronic schematic of the circuit to get produced. Right after the schematic was created, Computer Aided Manufacturing (CAM) software program is employed by engineers to produce the PCB prototype.
Once the PCB prototype is made, step one within the pcb fabrication and assembly would be to select the material from the printed circuit board. There are numerous kinds of PCB materials available, nevertheless the popular ones, based on the application as well as a customer’s requirements, include: Alumina, Arlon, Bakelite, CEM1, CEM5, Ceramic, FR1, FR4, FR4 High Temperature, GeTek, Nelco, Polyimide and Rogers.The style requirement dictates the size of the PCB (I.e., length, width and thickness).
Following the material has been selected, the first process is to apply a coating of copper to the entire board. The circuit layout will be printed on the board by way of a photosensitive process. Then, a photo engraving process will be used so that all of the copper which is not part of the circuit layout will be etched out or taken from the board. The resulting copper produces the traces or tracks of the PCB circuit. To get in touch the circuit traces, two processes are used. A mechanical milling process uses CNC machines to eliminate the unnecessary copper from your board. Then, an etch-resistant, silk-screen, printing process is applied to protect the regions where traces must exist.
At this point in the flexible pcb, the PCB board contains copper traces without any circuit components. To mount the components, holes must be drilled in the points where electrical and electronics parts are positioned on the board. The holes are drilled with either lasers or perhaps a special sort of drill bit made of Tungsten Carbide. After the holes are drilled, hollow rivets are inserted into them or these are coated by an electroplating process, which produces the electrical connection between the layers of the board. A masking material is then placed on coat the whole PCB with the exception of the pads as well as the holes. There are many varieties of masking material like, lead solder, lead free solder, OSP (Entek), deep/hard gold (electrolytic nickel gold), immersion gold (electroless nickel gold – ENIG), wire bondable gold (99.99% pure gold), immersion silver, flash gold, immersion tin (white tin), carbon ink, and SN 100CL, an alloy of tin, copper, and nickel. The final step in the PCB fabrication process would be to screen print the board so labels and also the legend appear at their proper locations.
Testing the caliber of the PCB Board – Just before placing the electrical and electronic components on the PCB, the board needs to be tested to confirm its functionality. In general, the two main kinds of malfunctions that will ysfurn a faulty PCB: a brief or an open. A “short” is a connection between two or more circuit points that should not exist. An “open” is a point where a connection should exist but does not. These faults must be corrected before the PCB is assembled. Unfortunately, some rigid flex printed circuit boards do not test their boards before they may be shipped, which can cause problems in the customer’s location. So, quality testing is a crucial procedure for the PCB fabrication process. Testing ensures the PCB boards will be in proper working condition prior to component placement.