Printed Circuit Board Material Properties

Fr 4 is a common material for printed circuit boards pcbs.

Printed circuit board material properties.

A thin layer of copper foil is laminated to one or both sides of an fr 4 glass epoxy panel. Multi layer boards sandwich additional copper layers between layers of insulating material. A printed circuit board pcb is a board made of different heat resistant insulating materials. When ordering a copper clad laminate board the fr 4 and copper thickness can both vary and so are specified separately.

Conductors on different layers are connected with vias which are copper plated holes that function as electrical tunnels through the insulating substrate. They include materials for flexible film circuit and membrane switches as well as rigid laminates for circuit boards. Conductive copper tracks are printed or etched onto this con conductive base substrate. They can be as simple as one or two layers of copper or in high density applications they can have fifty layers or more.

Printed circuit materials have copper clad surfaces for the fabrication of electronic and electrical circuitry on printed circuit boards pcbs printed wiring boards pwb and flexible circuits. This material is very thin 1 2 and 4 mil cores flexible lightweight has very low moisture absorption as well as a high chemical resistance. External factors like heat cold and moisture can have an impact on a material s resistivity. Like all dielectric insulators the material on a printed circuit board must have high resistivity preferably in the range of 10 3 to 10 10 megaohm centimeters.

A printed circuit board can have multiple copper layers. Lcp is a unique thermoplastic material that can be used to manufacture multilayer printed circuit boards. The material used in pcb from top to bottom includes silkscreen soldermask copper and substrate. Typical values for glass epoxy laminates at 60 70 rh are 10 13 to 10 14 w sq 4 4 for an explanation of this unit see conductors and insulators.

A two layer board has copper on both sides. The last of those layers substrate is made of fiberglass and is also known as fr4 with the fr letters standing for fire retardant. Printed circuit boards pcbs are usually a flat laminated composite made from non conductive substrate materials with layers of copper circuitry buried internally or on the external surfaces. These are commonly referred to as copperclad laminates.

Here is an overview of the most important properties to consider for any dielectric material.