What are the advantages of using a multilayer circuit board?

What are the advantages of using multilayer circuit boards

Generally, the requirements of multi-layer electric board structure design and process production are very high, and the higher the number of layers, the more difficult it is. Suitable for use in more complex circuits. So what are the advantages of using multi-layer circuit boards, let's learn together

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

　　In addition, from the perspective of cost, when comparing the cost of the same area, although the cost of a multi-layer circuit board is higher than that of a single-layer circuit board, if other factors such as the miniaturization of the circuit board and the convenience of reducing noise are taken into account, the multi-layer circuit board is more expensive. The cost difference between boards and single-layer boards is not as high as expected. According to the data we know to simply calculate the area cost of the circuit board, the area of the double-layer circuit board that can be purchased per day is about 462mm2, and the area of the 4-layer circuit board is 26mm2, which means that the same circuit is designed. The use area of the circuit board can be reduced to 1/2 of the double-layer circuit board, so the cost is the same as that of the double-layer circuit board. Although batches of multiple layers will affect the cost per unit area of the circuit board, there will not be a 4 times price difference. If the price difference is more than 4 times, as long as you can try to reduce the use area of the circuit board, and try to reduce it to 1 of the double-layer board. /4 or less.

　　Our common computer boards usually use four -layer 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 that there are two more internal signal layers in the middle, that is, between the ground layer and the power layer, which is thicker than the four-layer board.

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

　　For a simple circuit like a radio, a single- or double-sided fabrication is sufficient. However, with the development of microelectronics technology, the complexity of the circuit has been greatly improved, and higher requirements have been placed on the electrical performance of the circuit board. If a single-sided or double-sided board is also used, the circuit volume will be very large, and the wiring will also be affected. It is very difficult, in addition, the electromagnetic interference between the lines is not easy to deal with, so there is a multi-layer board (the number of layers means that there are several independent wiring layers, usually an even number).

　　The pcb circuit board manufacturer has three or more layers of conductor patterns on the multi-layer printed circuit board, and the conductor layer is divided into inner layer and outer layer. The inner layer is the conductor pattern completely sandwiched inside the multilayer board; the outer layer is the conductor pattern on the surface of the multilayer board. In general, the inner layer conductor pattern is processed first, and the hole and the outer layer conductor pattern are processed after pressing, and the inner and outer layers are connected by metallized holes.