Introduction to FR - 4 Material

PCB (Printed Circuit Board) refers to the substrate that mounts electronic components. The base material is the fundamental material constituting the circuit board, and the production of the printed circuit is completed on this base material.

The base material mainly refers to dielectric materials, which are composed of epoxy resin, reinforcing materials, and fillers.

PCBMASTER will introduce the base materials currently applied in the electronics industry and briefly describe the characteristics of their manufacturing processes and reliability requirements.

Copper foil, resin, reinforcing materials, and fillers.

Copper Foil

1.The function of copper foil is to form circuits. Copper foil is mainly divided into two categories:

Electrolytic Copper Foil (ED Foil - Electrodeposited Foil)

Through the electroplating method, in the copper sulfate plating solution environment, the distance between the anode and cathode in the giant plating tank is extremely small. The cathode wheel made of stainless steel rotates at a high speed to impact the plating solution. With a high current (600ASF), continuous sheet-like copper foil can be peeled off from the smooth surface of the roller. After post-treatment, it becomes commercial copper foil. The side facing the roller is called the DrumSide (the shiny side), and the side facing the plating solution is called the MatteSide (the rough side). It is applied to the vast majority of printed circuit boards, mainly on rigid boards (Rigid Board).

Rolled - wrought copper foil
The copper ingot is processed into copper foil through hot - rolling or cold - forging methods.
It is applied to circuit boards with high requirements for bending and tensile strength, mainly on flexible boards (Flexible).