Laminated structure is not only an important factor affecting the EMC performance of PCB board, but also an important means to restrain electromagnetic interference. With the continuous emergence of high-speed circuits, the complexity of HDI board is getting higher and higher. In order to avoid the interference of electrical factors, the signal layer and power layer must be separated, so the PCB multilayer design is involved. So, what are the common laminated structures of HDI multilayers?
1. Simple primary laminated printed board
There are 6 layers at a time, and the laminated structure is (1-4-1). This kind of plate is the simplest, that is, there are no buried holes in the inner multilayer plate, which can be completed at one time. Different from multilayer plates, laser drilling blind holes and other processes are needed in the follow-up.
2. Conventional HDI PCB with primary lamination
One-time lamination of HDI 6 laminates, stacked into a structure of (1-4-1). The structure of this kind of plate is (1+N+1), (N ≥ 2 and N even). This structure is the mainstream design of primary laminate in the industry at present. The inner multilayer has buried holes and needs to be completed by secondary pressing.
3. HDI PCB with conventional secondary lamination
Secondary lamination HDI 8 laminate, stacked into a structure of (1x 1x 4m 1m 1). The structure of this kind of plate is (1+1+N+1+1), (N ≥ 2 and N even). This structure is the mainstream design of secondary lamination in the industry at present. The inner multilayer has buried holes and needs to be pressed three times.
4. The second kind of conventional secondary stacking HDI PCB.
Secondary lamination HDI 8 laminate, stacked into a structure of (1-1-4-1-1). The structure of this kind of plate (1+1+N+1+1), (N ≥ 2 and N even number), although it is the structure of secondary laminated board, because the position of buried hole is not between (3-6) layers, but between (2-7) layers, this design can reduce the compression once, so that the secondary laminated HDI parts need three times pressing process, which is optimized to two times pressing process.
5. HDI of secondary accumulation layer designed by blind hole stacking.
The blind holes are stacked above the buried holes (2-7), and the HDI 8 laminates are secondary accumulated, and the stacked structure is (1-1-4-1-1). The structure of this kind of plate is (1+1+N+1+1), (N ≥ 2 and N even number), and the inner multilayer has buried holes and needs to be completed by secondary pressing.
6. HDI of secondary accumulation layer designed by cross-layer blind hole.
Secondary lamination HDI 8 laminate, stacked into a structure of (1-1-4-1-1). The structure of this kind of plate is (1+1+N+1+1), (N ≥ 2 and N even). At present, this structure is a secondary laminated board which is difficult to be made in the industry. the inner multilayer has buried holes in (3-6) layers and needs to be pressed three times.
7. Optimization of HDI panels with other laminated structures.
PCB boards with three times lamination or more than three times lamination can also be optimized. A complete HDI board with three times lamination requires 4 times pressing.
