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
Excessive resin powder but microcracks are allowed
AlteraFlex have the following FR4 prepregs in stock:
| PP Type | Thickness(Brand difference) |
| 1080 | 0.086mm(3.4mil),0.080mm(3.15mil) |
| 2116 | 0.109mm(4.3mil),0.115mm(4.53mil) |
| 7628 | 0.188mm(7.4mil),0.185mm(7.28mil) |
Rogers Prepregs:
| PP Type | |
| Rogers 4350B | Er=3.5 |
| RO4450B | 0.1mm 3.54± 0.05 (10G) |
Core
AlteraFlex 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.
AlteraFlex also manufactures PCBs with metal cores.
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. AlteraFlex has copper foil of 12μm,18μm,36μm, 54μm , 90μm and etc. in stock.
Have Questions?
If you have any questions or need any further information, please feel free to contact your dedicated customer service.
