In 1936, the very first printed circuit board (PCB) was developed by Paul Eisle. However 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. PCBs are now utilized in virtually all manufactured products including, automobiles, cellular telephones, computers, 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 in the circuit to get produced. Right after the schematic is made, Computer Aided Manufacturing (CAM) application is utilized by engineers to create the PCB prototype.
After the PCB prototype was created, the initial step within the PCB production is always to pick the material of the printed circuit board. There are many different kinds of PCB materials available, but the popular ones, based on the application and 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).
Right after the material has been selected, the very first process is to apply a coating of copper towards the entire board. The circuit layout will then be printed on the board by way of a photosensitive process. Then, a photo engraving process is going to be used to ensure that all the copper which is not part of the circuit layout will be etched out or removed from the board. The resulting copper produces the traces or tracks in the PCB circuit. For connecting the circuit traces, two processes are employed. A mechanical milling process will use CNC machines to remove the unnecessary copper from your board. Then, an etch-resistant, silk-screen, printing process is used to protect the regions where traces must exist.
At this time in the flexible pcb manufacturer, the PCB board contains copper traces with no circuit components. To mount the ingredients, holes must be drilled on the points where electrical and electronics parts are placed on the board. The holes are drilled with either lasers or even a special type of drill bit made of Tungsten Carbide. When the holes are drilled, hollow rivets are inserted into them or they may be coated by an electroplating process, which creates the electrical link between the layers of the board. A masking material will then be put on coat the whole PCB except for the pads and the holes. There are numerous kinds of masking material including, 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 part of the PCB fabrication process is to screen print the board so labels as well as the legend appear at their proper locations.
Testing the standard of the PCB Board – Just before placing the electrical and electronic components on the PCB, the board ought to be tested to verify its functionality. Generally speaking, the two main kinds of malfunctions that can ysfurn a faulty PCB: a quick or perhaps an open. A “short” is a link between several circuit points which should not exist. An “open” is a point in which a connection should exist but fails to. These faults has to be corrected ahead of the PCB is assembled. Unfortunately, some rigid flex circuits do not test their boards before these are shipped, which can lead to problems on the customer’s location. So, quality tests are a critical procedure for the PCB fabrication process. Testing ensures the PCB boards have been in proper working condition before component placement.