What is FR-4 PCB material?
We've all heard the abbreviation FR4 being tossed about at some point when purchasing a PCB fab home, but what does it really mean? And what ramifications does it have when picking a PCB material? This post will help clear the fog and present some popular materials readily available for rigid PCBs.
More than likely, you will have seen FR4 as the basic option for small batch or model PCBs like in Speed Fusion. FR-4 describes a grade of material rather than a material itself and has numerous sub gradings and types such as TG130, High TG, FR4-Rogers. The FR4 alternative on the PCB order page is the grade designation for the epoxy fiberglass that frequently forms the PCB core and prepreg layers. It is the homes of this base that provides the PCB the electrical seclusion and mechanical strength needed to endure progressively requiring applications.
In a typical PCB, the core supplies the rigidity and the foundation on which the PCB traces can be 'printed' onto. In addition, the FR4 core and laminates form the electrical seclusion separating copper layers. For double layer boards, an FR4 core separates the leading and bottom copper layers whereas, in multilayer PCBs, additional layers of FR4 prepreg are sandwiched in between the inner core and the outer copper layers. The wanted final thickness of the PCB can be managed by including or removing individual laminates or using laminates of various densities. For example, generally, a 1.6 mm board will have 8 layers of fiberglass sheets, if we desired a 0.8 mm board we can lower the variety of sheets to 4.
The name FR4 originates from the NEMU grading system where the 'FR' stands for 'fire retardant', compliant with the UL94V-0 requirement. You might have seen that on the Speed Fusion order page the FR4 option is followed by TG130. The TG describes the shift glass temperature-- the temperature at which FR4 Material the glass-reinforced material will start to warp and soften. For Fusion's basic boards this value is 130 ° C, which is more than enough for many applications. Unique High TG materials can hold up against temperatures of 170-- 180 ° C and can be purchased online utilizing the Advanced PCB service.
FR4 laminates owe their flame resistance due to its bromine material, a non-reactive halogen commonly used in market for its flame retarding homes. This offers FR4 materials obvious advantages as a stock PCB material, particularly in prototyping where circuits are still in the preliminary screening phases and might be pushed to extremes. It is also a little assuring if your soldering skills are not up to requirement.
Other similar grades used for PCBs include FR2, which is a kind of fire slowing down fiberglass resin bonded paper and G10 which is not flame resistant at all. FR2 is more affordable therefore has its uses in mass production of low-end electrical equipment. G10, a predecessor to FR4, has all but been taken control of by the much safer FR4 requirement. Its only usage in PCBs now remains in designs that desire this flammable residential or commercial property.
This blog site has actually covered more details on stiff PCB materials than the typical hobbyist will ever need, but ought to you ever find the usage for High TG or more specific materials, you can examine out Speed Fusion Advanced PCB service for more alternatives consisting of high-frequency boards and rigid-flex PCBs.
The FR4 alternative on the PCB order page is the grade designation for the epoxy fiberglass that often forms the PCB core and prepreg layers. In a typical PCB, the core supplies the rigidness and the structure on which the PCB traces can be 'printed' onto. For double layer boards, an FR4 core separates the bottom and top copper layers whereas, in multilayer PCBs, extra layers of FR4 prepreg are sandwiched in between the outer copper and the inner core layers. Typical thinner densities are utilized in multilayer boards in which the FR4 board is used to distribute signals to other boards, in order to not increase the density of the PCB. Greater thicknesses are used when high effectiveness of the PCB is needed since a large PCB is created.