Cost cores Foil & Prepreg for PCBs

Prepreg:

A prepreg is also called “PP sheet”, it is one of the main materials in the production of multilayer boards. It is mainly composed of resin and reinforced materials. Reinforcing materials are divided into several types, such as glass fiber cloth, paper base, composite materials, etc. Most of the prepregs (bonding sheets) used in printed boards are made of fiberglass cloth as a reinforcing material.

After treatment of glass fiber cloth, impregnated with resin glue solution, and then heat treatment (pre-bake) to make the resin into the B stage and made of sheet material called prepreg, which will soften under heat and pressure, will react and solidify after cooling. Since the number of yarn strands in the warp and weft unit lengths of the glass fiber cloth is different, the latitude and longitude directions of the prepreg should be taken into account when cutting. Generally, the direction of warp (the direction of curling of the glass fiber cloth) is used as the short side direction of the production board, and the weft direction to produce the long side of the board to ensure that the board is flat and prevent the board from being distorted after being heated.

The main appearance requirements of the prepreg used for the multilayer board are: the cloth surface should be smooth, free of oil, stains, foreign matter or other defects, no cracks, and excessive resin powder, but microcracks are allowed. In the PCB design process, if it is a multilayer board design, prepreg must be used. Besides, in the process of multi-layer board copying, it must be polished out to accurately analyze the schematic circuit diagram.

PCBWay have the following FR4 prepregs in stock:

Rogers Prepregs:

Rogers 4450F

Core

PCBWay can provide Clear soldermask and black core PCB， When you place an order，PCB Specification Selection，"Standard PCB/Advanced PCB" > +Additional Options > Black FR4 (black core) 

Circuit boards cores are pre-pressed layers according to the pattern: copper foil – prepreg – copper foil. PCBWay also manufactures PCBs with metal cores.

PCBWay normally has the following circuit boards cores in stock:

Copper foils

The copper for the outer layers of multilayer boards is applied in the form of copper foil and pressed together with the prepregs/cores. PCBWay has copper foil of 12μm,18μm,36μm, 54μm , 90μm and etc. in stock.