You see eight main design layers in the PCB

It is important to understand and distinguish the layers of a PCB. 為了更好地了解 PCB 的確切厚度，需要進行精細區分以確保 PCB 以最大效率工作。 The following layers are typically seen in stacked PCBS. These may vary, depending on the number of layers, the designer, and the design itself.

L mechanical layer

This is the basic layer of a PCB. It is used as the outline of the circuit board. This is the basic physical framework of a PCB. 該層還使設計人員能夠傳達鑽孔和切口的確切位置。

L keep layer

This layer is similar to the mechanical layer in that it can also be used as a contour. 然而，保持層的作用是界定用於放置電子元件、電路佈線等的外圍。 任何組件或電路都不能放置在此邊界之外。 該層限制了 CAD 工具在特定區域的佈線。

L routing layer

路由層用於連接組件。 These layers can be located on either side of the circuit board. 層的放置取決於設計者，他根據應用程序和使用的組件做出決定。

L Grounding plane and power plane

These layers are critical to the proper operation of a PCB. Ground grounding and distribution of grounding throughout the circuit board and its components. 另一方面，電源層連接到位於 PCB 本身上的一個電壓。 Both layers can appear on the top, bottom, and break plates of the PCB.

L 分割平面

分裂平面基本上是分裂電源平面。 例如，板上的電源層可以一分為二。 電源層的一半可以連接到+ 4V，另一半可以連接到-4V。 Thus, components on a board can operate with two different voltages depending on their connections.

L Cover/screen layer

The silkscreen layer is used to implement text markers for components placed on top of the board. 除了板的底部，覆蓋層執行相同的工作。 These layers aid in the manufacturing and debugging process.

l 電阻焊層

Copper wiring and through-holes on circuit boards are sometimes referred to as protective coverings of solder resistance layers. This layer keeps dust, dust, moisture and other environmental factors away from the board.

L the solder paste layer

Use solder paste after assembly surface mounting. It helps to weld components to the circuit board. It also facilitates free flow of solder in a PCB consisting of surface-mounted components.

All of these layers may not exist in a single-layer PCB. These layers are based on the printed circuit board design. These design layers help estimate the total thickness of the PCB when each micron thickness is accounted for. These details will help you maintain the strict tolerances found in most PCB designs.