Why Are Circuit Boards All Multi-Layered, Not Single-Layered?

For the most basic printed circuit board, the components are concentrated on one side, and the wires are concentrated on the other side. Because only one side can be routed, we call this kind of circuit board a single-sided board. Both sides of the double-sided board can be wired, so the wiring area is twice as large as that of the single-sided board, which is suitable for more complicated circuits.

For simple circuits such as radios, single-sided or double-sided manufacturing is sufficient. However, with the development of microelectronics technology, the complexity of circuits has greatly increased, and higher requirements have been placed on the electrical performance of circuit boards. If single-sided or double-sided boards are used, the circuit volume will be very large, and the wiring will also be used. It is very difficult. In addition, the electromagnetic interference between the lines is not easy to handle, so a multilayer board appears (the number of layers represents several independent wiring layers, usually an even number).

The advantages of using multi-layer boards are high assembly density and small size, the connection between electronic components is shortened, and the signal transmission speed is improved, convenient wiring, for high-frequency circuits, a ground layer is added to make the signal line to the ground constant low impedance, good shielding effect. However, the more layers, the higher the cost, the longer the processing cycle, and the more troublesome quality inspection.

Our common computer boards usually use four-layer boards or six-layer boards, but now there are more than 100 layers of practical printed circuit boards. The difference between the six-layer board and the four-layer board is in the middle, that is, there are two more internal signal layers between the ground layer and the power layer, which are thicker than the four-layer board.

Multilayer boards are actually formed by laminating and bonding several etched single or double panels. The double panel is easy to distinguish. Looking at the light, except for the wiring on both sides, other places are transparent. For the four-layer board and the six-layer board, because the layers in the circuit board are very tightly combined, if there are corresponding marks on the board, there is no good way to distinguish.

XPCB Limited is a manufacturer specializing in the production of high-precision double-sided, multilayer and impedance, blind buried vias, thick copper circuit boards, products covering HDI, thick copper, backplanes, rigid-flex combined, buried capacitance and buried resistance , Golden Finger and other types of circuit boards, which can meet the needs of customers for various products.