Almost every conceivable electrical item nowadays contains a printed circuit board. Despite being so ubiquitous, it is not generally well known exactly what they are, or how they are made by the printed circuit board manufacturer. As they lurk inside so many everyday items, it is of interest to learn more about them, and the ways in which they are made.
Electrical appliances which rely on printed circuit boards (abbreviated as PCBs), include computers, mobile phones, televisions and microwave ovens, although nearly all electric devices utilize PCBs in some form. While there are alternatives to using PCBs, over the years they have become known as the most time and cost effective solution.
PCBs are used to create the electric circuits that make appliances work. While there are various types of PCB, their typical role is to physically support the components, and provide some form of electrical connection between them. Two of the main PCB raw materials are laminates, and copper-clad laminates.
To make a PCB, cloth or paper are layered with resin to create rigid, slim boards. During this process, the materials are warmed and pressurized for optimum results. These boards are called laminates, and by themselves they cannot conduct electricity. For this purpose, either the entire board is coated with copper (as in the copper-clad laminate), and any that is unwanted is subsequently removed, or else the user adds copper only as desired.
Where the copper is added only as needed, the processing is complex and involves several steps. However, most PCBs start out as a copper-clad laminate. Chemicals are used to erode the extra copper which is not required for the circuit, in a process called etching.
During the application of etching chemicals, any copper which is not to be removed must be protected. In most cases, silk screen printing is used to apply an ink which will resist the etching process, thus protecting the copper.
Although various advanced techniques are now used in etching, one basic approach would be applying the protective ink to the board in the desired configuration and then submerging it in etching chemicals. The copper then dissolves, leaving the required circuit connections. Manufacturers make this process faster with methods which help to remove the copper as it is eaten away, for example by using sprays. In spray etching, the etching fluid is actually sprayed at the PCB. The manufacturer can direct the spray, as well as the type of jet and its temperature, for the best results.
Before components can be added to the PCB, holes must be drilled for each one. Due to the properties of the laminate board, steel drill bits would be blunted very quickly, resulting in tearing of the fine copper connectors. This problem is overcome by using special tungsten carbide drill bits.
While these are some of the main processes used by a printed circuit board manufacturer, PCBs have been in large scale use since the 1940s. During this period, many techniques have emerged and fallen out of favor, but features such as laminates, etching, silk screen printing and tungsten carbide drill bits have all stood the test of time.
Electrical appliances which rely on printed circuit boards (abbreviated as PCBs), include computers, mobile phones, televisions and microwave ovens, although nearly all electric devices utilize PCBs in some form. While there are alternatives to using PCBs, over the years they have become known as the most time and cost effective solution.
PCBs are used to create the electric circuits that make appliances work. While there are various types of PCB, their typical role is to physically support the components, and provide some form of electrical connection between them. Two of the main PCB raw materials are laminates, and copper-clad laminates.
To make a PCB, cloth or paper are layered with resin to create rigid, slim boards. During this process, the materials are warmed and pressurized for optimum results. These boards are called laminates, and by themselves they cannot conduct electricity. For this purpose, either the entire board is coated with copper (as in the copper-clad laminate), and any that is unwanted is subsequently removed, or else the user adds copper only as desired.
Where the copper is added only as needed, the processing is complex and involves several steps. However, most PCBs start out as a copper-clad laminate. Chemicals are used to erode the extra copper which is not required for the circuit, in a process called etching.
During the application of etching chemicals, any copper which is not to be removed must be protected. In most cases, silk screen printing is used to apply an ink which will resist the etching process, thus protecting the copper.
Although various advanced techniques are now used in etching, one basic approach would be applying the protective ink to the board in the desired configuration and then submerging it in etching chemicals. The copper then dissolves, leaving the required circuit connections. Manufacturers make this process faster with methods which help to remove the copper as it is eaten away, for example by using sprays. In spray etching, the etching fluid is actually sprayed at the PCB. The manufacturer can direct the spray, as well as the type of jet and its temperature, for the best results.
Before components can be added to the PCB, holes must be drilled for each one. Due to the properties of the laminate board, steel drill bits would be blunted very quickly, resulting in tearing of the fine copper connectors. This problem is overcome by using special tungsten carbide drill bits.
While these are some of the main processes used by a printed circuit board manufacturer, PCBs have been in large scale use since the 1940s. During this period, many techniques have emerged and fallen out of favor, but features such as laminates, etching, silk screen printing and tungsten carbide drill bits have all stood the test of time.
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