Detailed Explanation of PCB Multilayer Circuit Board Manufacturing Process (Part 1)

As electronic products demand more and more functions, the structure of pcb circuit boards is becoming more and more complex. Due to the space limitation of PCB circuit boards, circuit boards are gradually “evolving” from single layer to double layer to multilayer. So what is the difference between the manufacturing process of multilayer pcb circuit boards and double-layer pcb circuit boards? Let me introduce it below. 　　

Multilayer pcb circuit board is a kind of printed circuit board which is laminated and bonded by alternating conductive pattern layers and insulating materials. The number of layers of the conductive pattern is more than three, and the electrical interconnection between the layers is realized through metallized holes.

If one double-sided board is used as the inner layer, two single-sided boards are used as the outer layer, or two double-sided boards are used as the inner layer and two single-sided boards are used as the outer layer, the positioning system and the insulating bonding material are laminated together, and the conductive pattern is pressed together. The design requires interconnection, which becomes a four-layer or six-layer printed circuit board, also called a multilayer pcb circuit board.

Multilayer pcb circuit boards are generally made of epoxy glass cloth copper clad laminates, and their manufacturing process is developed on the basis of the process of plated-through double-sided boards. Its general process is to first etch the graphics of the inner layer board, after blackening treatment, add prepress according to the predetermined design to laminate, and then put a piece of copper foil on the upper and lower surfaces, and send them to the press for heating. After pressing, a “double-sided copper clad laminate” with an inner layer pattern prepared is obtained.