Printed Circuit Board is the support body of electronic components and the carrier of electrical connection of electronic components. Before the appearance of PCB, the connection between electronic components was completed by direct connection of wires; Today, the wire connection method is only used in laboratory tests, and PCB has occupied an absolute control position in the electronics industry.
The past life of PCB circuit board
The history of PCB development dates back to the early 20th century. In 1936, the Austrian Paul Eisler (Paul Eisler) in the radio application of PCB, the first PCB into practical, 1943, the United States will be widely used in military radio, 1948, the United States officially recognized the invention can be used for commercial use. Since the mid-1950s, PCB circuit boards have been widely used, and then entered a period of rapid development.
As PCBS become more and more complex, designers are prone to confusion about the definition and use of each board layer when using development tools to design PCBS. When hardware developers draw PCB by themselves, it is easy to lead to unnecessary misunderstandings in production because they are not familiar with the use of each board layer of PCB. In order to avoid this situation, here Altium Designer Summer 09 is used as an example to classify and introduce the board layers of PCB.
What is the function between the layers of the PCB board
1. Signal Layers
Altium Designer offers up to 32 signal layers, including the Top Layer, Bottom Layer, and Mid-Layer. The layers can be interconnected through Via, Blind Via and Buried Via.
(1) Top Layer
Also known as the component layer, it is mainly used to place components, for double-layer circuit boards and multi-layer circuit boards can be used to arrange wires or copper coating.
(2) Bottom Layer
Also known as the welding layer, it is mainly used for wiring and welding, and can be used to place components for double-layer circuit boards and multi-layer circuit boards.
(3) Mid-Layers
There can be up to 30 layers, which are used to arrange signal lines in multi-layer circuit boards, excluding power cables and ground cables.
2. Internal power layer (Internal Planes)
Usually referred to as the internal electrical layer, only in the multi-layer board, the number of PCB board layers generally refers to the sum of the signal layer and the internal electrical layer. The same as the signal layer, the inner electric layer and the inner electric layer, the inner electric layer and the signal layer can be connected through holes, blind holes and buried holes.
PCB layer labeling
3. Silkscreen Layers
A PCB board can have up to 2 screen printing layers, respectively, Top Overlay and Bottom Overlay, generally white, mainly used to place printed information, such as the outline and annotation of components, various annotation characters, etc., to facilitate PCB component welding and circuit inspection.
(1) Top Overlay
It is used to mark the projected outline of the component, the label of the component, the nominal value or model number, and various comment characters.
(2) Bottom Overlay
Same as the top screen layer, if all marks on the top screen layer are included, the bottom screen layer can be closed.
4. Mechanical Layers
The mechanical layer is generally used to place indicative information about board making and assembly methods, such as PCB dimensions, size marks, data, hole information, assembly instructions and other information. This information varies according to the requirements of the design company or PCB manufacturer, and the following examples illustrate our common methods.
Mechanical 1: It is generally used to draw the border of the PCB as its mechanical shape, so it is also called the outline layer;
Mechanical 2: We use to place the PCB machining process requirements table, including size, sheet, sheet layer and other information;
Mechanical 13 & Mechanical 15: Body size information of most components in ETM library, including 3D models of components; For simplicity of the page, this layer is not displayed by default;
Mechanical 16: The occupying area information of most components in the ETM library can be used to estimate PCB size at the early stage of the project; For simplicity of the page, this layer is not displayed by default and is colored black.
5. Mask Layers
Altium Designer offers two types of Mask Layers, a Solder Mask and a Paste Mask, with a top layer and a bottom layer, respectively.
The above is the PCSPCB to share the role of the pcb board between the layers, you get it? More pcb circuit board knowledge can pay attention to the Mosaic technology, PCSPCB high-end circuit board R & D and production for you to update more pcb knowledge.
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