Manufacturing process of multi-layer pcb circuit board

As the demand for electronic products increases, the structure of pcb boards becomes more and more complex. Due to the space limitations of the pcb board, the circuit board is also gradually "evolving" from a single layer to a double layer to a plurality of layers. So what is the difference between the multi-layer pcb circuit board and the double-layer pcb circuit board in the manufacturing process?

The multi-layer pcb circuit board is a 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 layers, and the electrical interconnection between the layers is realized by the metallized holes. If a double panel is used as the inner layer, two single panels are used as the outer layer or two double panels as the inner layer, and two single panels are used as the outer layer, the positioning system and the insulating bonding material are laminated together, and the conductive pattern is pressed. Designed to interconnect, it becomes a four-layer, six-layer printed circuit board, also known as a multi-layer pcb circuit board.

Multi-layer pcb circuit boards are generally fabricated from epoxy glass cloth-clad laminates, and the manufacturing process is based on the process of plating double-panel holes. Its general process is to etch the pattern of the inner layer first. After the blackening process, the prepreg is added according to the predetermined design for lamination, and then a piece of copper foil is placed on the upper and lower surfaces, and sent to the press for heating. After pressing, a "double-sided copper clad plate" with an inner layer pattern is prepared, and then a numerically controlled drilling is performed according to a pre-designed positioning system. After the drilling, the wall of the hole is subjected to etching treatment and desmear treatment, and then the process of printing the circuit board by double-sided plating is carried out.