A printed circuit board (PCB) is formed by printing a circuit line pattern on an electrical insulating substrate by using a conductive material such as copper (Cu), and refers to a board right before electronic parts are mounted thereon. In other words, the PCB refers to a circuit board in which the mounting positions of the electronic parts are determined, and a circuit pattern connecting the electronic parts to each other is fixedly printed on the surface of a flat plate so that several types of many electronic devices are densely mounted on the flat plate
Meanwhile, in recent years, a buried pattern substrate having the reduced thickness and planarized surface has been used for the purpose of high performance and miniaturization of electronic parts.
FIG. 1 is a sectional view showing a typical buried pattern PCB 10.
As shown in FIG. 1, the buried pattern PCB 10 includes a buried pattern groove 2 in the surface of an insulating substrate 1 and a circuit pattern 3 formed by filling the buried pattern groove 2 through a plating process.
The PCB 10 having the buried circuit pattern 3 can represent very strong adhesive strength with respect to an insulating member due to the formation structure of a base circuit pattern and a contact part, and the pitches of base circuit patterns and contact parts can be uniformly and finely formed.