Difficulties in The Production of Multi-Layer PCB

Generally speaking, circuit boards with more than 10 layers are called multi-layer PCB boards, which are very different from traditional multi-layer boards. For example, the processing and production are more difficult, and the product stability is higher. Because of its wide range of applications, it has huge development potential. At present, most domestic manufacturers of multi-layer PCB boards are Sino-foreign joint ventures, or even directly foreign companies. Multi-layer PCB boards have relatively high requirements on the level of craftsmanship, and the initial investment is large. It not only requires advanced equipment, but also a test of the technical level of the staff. Coupled with the cumbersome user certification procedures, many manufacturers do not have the ability to produce multi-layer PCB boards, so multi-layer PCB boards are still very impressive market prospects.

The following are some points that I think should be paid attention to in the production process of multilayer boards.

1. Alignment

The more the number of layers, the higher the requirements for the degree of alignment between the layers. Generally speaking, the alignment tolerance between layers is controlled within ±75μm. Due to the influence of factors such as size and temperature, the degree of difficulty in controlling the alignment between layers of a multilayer board will be very large.

2. Inner Circuit

The materials used to make multi-layer boards are also very different from other boards. For example, the surface of the multi-layer board is thicker. This increases the difficulty of the layout of the inner line. If the inner core plate is relatively thin, it is prone to abnormal exposure, which may be due to wrinkles. Generally speaking, the unit size of the multilayer board is relatively large, and the production cost is high. Once there is a problem, it will be a huge loss for the enterprise. It is very likely that there will be a situation of making ends meet.

3. Pressing

It is called a multilayer board, and there will definitely be a process of pressing. In this process, delamination, skateboarding will occur if you are not paying attention. So we have to consider the properties of materials when designing. The greater the number of layers, the amount of expansion and contraction and the compensation of the size factor will be difficult to control, and problems will follow. If the insulating layer is too thin, the test may fail. Therefore, pay more attention to the pressing process, as there will be more problems at this stage.

4. Drilling

Because special materials are used to make multi-layer boards, the difficulty of drilling is also increased a lot. It will also be a test for drilling technology. Because the thickness is increased, drilling is easy to break, and a series of problems such as inclined drilling may occur. So we need to pay more attention to it!