PCB Essentials
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PCB base material: Basis for all electronic components
Circuit boards are something like the nervous system of electronics. They have all the electrical components and circuitry that devices need to function, from the huge refrigerator, to the desktop computer, to the smartphone. If you want to build an electronic system from scratch, you start with the PCB base material. In our guide you will learn what was to be observed.
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What was the PCB base material?
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What types of base material are there?
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What to watch out for when you buy?
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Our practical tip: Maintain printed circuit boards with cleaner and protective resin
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FAQ - Frequently Asked Questions about PCB Base Material
What was the PCB base material?
PCB base material forms the basis for an electronic board or PCB. PCBs are used in almost all electronic devices as carriers for electronic components, such as circuits, data memories and connection slots. The parts are either attached or firmly soldered on a rectangular card. It consists primarily of an insulating core of basic materials. There are one or two conductor paths, mostly consisting of copper, which connect components located on circuit boards with each other or with the power supply. If necessary, there is a thin photo coating between the copper and the base material core. By means of ultraviolet exposure, the subsequent course of the metallic conductor paths is determined during the production.
Boards are not available in a uniform size. Depending on the application area, the available space and the number of components to be attached, maps of different dimensions and different thickness are required. For hobbyists and professional producers, manufacturers therefore offer the starting material for printed circuit boards in larger areas, which can be cut to size as required.
What types of base material are there?
Basic material for PCBs differs primarily in the materials used. Most common are unpopulated epoxy resin PCBs. In the technical language, they are also simply referred to as epoxies or epoxies. Epoxides alone are not heat resistant and can therefore be brought into the typical rectangular circuit board shape during production under high temperatures. It is only by mixing hardening agents that they become duroplastic. This means that they are thermally and chemically resistant after curing.
Another common base material is hard paper. This is a so-called composite material consisting of several interconnected materials. In hard paper, conventional paper made of wood and phenol, an epoxy-like synthetic resin are processed. Phenol, paper and epoxy can be mixed in different composition to produce a base material for printed circuit boards. The ratio can be seen at a glance by means of the flame retardant labeling of a base material: FR1, FR2, FR3 and FR4. The higher the number of a mark, the more epoxy and the less phenol are processed in the material labeled with it.
Less commonly, aluminum and synthetic polymers are also known as “IMS” (Insulated Metallic Substrates”) or metal core PCBs. In this case, the base material consists of two layers: The metallic aluminum core and a sleeve made of “prepreg” (short for “price-controlled fibres”, in German “pre-impregnated fibers”), i.e. textile fibers offset with plastic.
Another distinguishing feature of base material is its copper coating. The decisive factor is the film's thickness, i.e. how Dick is the foil with copper tracks. The thickness is usuallyµ expressed in micrometers ( m). The most common copper coating is 35µ m, but there are also far thinner supports such as 18µ m or thicker ones such as 70µ m and even 105µ m.
On the other hand, the number of copper layers is important. Basic material for PCBs can be coated on one side or on two sides. For single-sided coated plates, there are only copper traces on one side. Single-sided coated plates are still the most widely used, as they are sufficient for most applications and can be manufactured without much effort. Two-sided coated printed circuit boards Base material is more complex to manufacture because it uses more copper and requires through-hole connections. These are drill holes, which have been coated with copper from the inside and thus connect the two ladder planes with each other.
What to watch out for when you buy?
First and foremost, the budget and goal of a project decide which PCB material is best suited for this purpose. Metal core PCBs are much more thermally conductive than panels with a higher plastic content. They are therefore ideally suited for environments that generate a lot of heat, for example in LED lighting systems or high-performance computers with clock-strong processors. However, this performance is reflected in the price. In most cases IMS technology is particularly worthwhile for professional applications.
Hard paper is the most economical solution for printed circuit board materials. In addition, the copper coating adheres particularly well to it. In turn, it is more sensitive to heat and moisture damage. Printed circuit boards made of hard paper are therefore particularly suitable for hobbyists and other hobby electronics engineers who need short-lived, easy-to-process base material for visual and test purposes. Printed circuit boards made of epoxy are an ideal compromise.
Our practical tip: Maintain printed circuit boards with cleaner and protective resin
Not every piece of base material is used immediately. Reserves and surplus left when cutting a plate can still be used for projects long after purchase. However, in the case of prolonged storage or carelessness during the processing of base material, contamination or damage may occur that limit the functionality of printed circuit boards. In order to prevent dust deposits and oxidation, PCBs can be treated with solder lacquer. If there is any contamination, they can be removed using PCB cleaner. Both methods are available in our shop.
FAQ - Frequently Asked Questions about PCB Base Material
How can I cut PCB base material?
Base material for printed circuit boards can be used to the desired size by many different methods. Depending on the thickness and material, an ordinary household scissors or a carpet knife are enough. However, it is easier to make precise cuts with a better tool. For more resistant circuit boards it is therefore a good option to use a sheet metal shears or a small circular saw. For professional-level processing, solutions such as laser-based cutting systems designed specifically for the cutting of basic materials are available.
Is the base material recyclable?
The environmentally friendly disposal of populated and unpopulated printed circuit boards can be difficult. Processed metals such as aluminum or copper can be separated from other materials and reused. In contrast, the plastic epoxide cannot be recycled according to the latest state of the art technology. For professional and environmentally friendly disposal, it is advisable to contact a service provider specializing in electronic waste.