Printed circuit boards are at the heart of almost every type of electrical goods today, and yet the lay person has only the vaguest impression of what they actually are, much less how they are assembled by a printed circuit board manufacturer. As they have become an integral part of daily life, it is intriguing to find out more about these gadgets, and how they come to be.
Just a few everyday items using printed circuit boards (otherwise known as PCBs) are microwave ovens, televisions, computers, and mobile phones, although few electrical items don't contain PCBs nowadays. Arrangements other than the PCB do exist, but PCBs are the most economical and have the lowest production time.
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.
Many etching methods exist, but to summarize the basics, the required copper connections are marked onto the PCB with the special ink, and then the board is dipped in etching fluid. Unprotected copper will gradually dissolve, and the copper connections, as desired by the manufacturer, remain. Approaches to allow this stage to progress more quickly are based around moving away dissolving copper as the process continues. A popular variation is spray etching, where etching liquid is applied using sprays, the force of which will agitate the dissolving copper and bare the untreated copper underneath. The spray pattern, direction of the fluid and heat levels will be manipulated by the manufacturer to provide the most economical outcomes.
After the laminate and the conductors have been prepared, it is time to make holes for the electrical components. Laminate boards will quickly wear out a steel drill bit, leading to damage of the intricate conductors, and so extremely hard tungsten carbide drill bits are important to this stage of the process.
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.
Just a few everyday items using printed circuit boards (otherwise known as PCBs) are microwave ovens, televisions, computers, and mobile phones, although few electrical items don't contain PCBs nowadays. Arrangements other than the PCB do exist, but PCBs are the most economical and have the lowest production time.
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.
Many etching methods exist, but to summarize the basics, the required copper connections are marked onto the PCB with the special ink, and then the board is dipped in etching fluid. Unprotected copper will gradually dissolve, and the copper connections, as desired by the manufacturer, remain. Approaches to allow this stage to progress more quickly are based around moving away dissolving copper as the process continues. A popular variation is spray etching, where etching liquid is applied using sprays, the force of which will agitate the dissolving copper and bare the untreated copper underneath. The spray pattern, direction of the fluid and heat levels will be manipulated by the manufacturer to provide the most economical outcomes.
After the laminate and the conductors have been prepared, it is time to make holes for the electrical components. Laminate boards will quickly wear out a steel drill bit, leading to damage of the intricate conductors, and so extremely hard tungsten carbide drill bits are important to this stage of the process.
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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