What is FR-4 PCB material?
We've all heard the abbreviation FR4 being tossed about eventually when looking for a PCB fab home, however what does it really mean? And what ramifications does it have when choosing a PCB material? This post will help clear the fog and present some popular materials readily available for rigid PCBs.
Probably, you will have seen FR4 as the standard option for little batch or model PCBs like in Speed Fusion. FR-4 refers to 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 offers the PCB the electrical isolation and mechanical strength required to sustain significantly demanding applications.
In a common PCB, the core supplies the rigidness and the foundation on which the PCB traces can be 'printed' onto. In addition, the FR4 core and laminates form the electrical isolation 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 between the inner core and the external copper layers. The wanted final thickness of the PCB can be managed by including or removing individual laminates or utilizing laminates of various densities. For example, generally, a 1.6 mm board will have 8 layers of fiberglass sheets, if we wanted a 0.8 mm board we can reduce the variety of sheets to 4.
The name FR4 originates from the NEMU grading system where the 'FR' represents 'fire retardant', compliant with the UL94V-0 standard. You might have seen that on the Speed Fusion order page the FR4 option is followed by TG130. The TG refers to the shift glass temperature-- the temperature level at which the glass-reinforced material will begin to warp and soften. For Fusion's standard boards this worth is 130 ° C, which is more than enough for many applications. Special High TG materials can stand up to temperature levels of 170-- 180 ° C and can be ordered online using the Advanced PCB service.
FR4 laminates owe their flame resistance due to its bromine content, a non-reactive halogen typically utilized in market for its flame slowing down properties. This gives FR4 materials obvious benefits as a stock PCB material, specifically in prototyping where circuits are still in the preliminary testing stages and may be pushed to extremes. If your soldering skills are not up to standard, it is also a little guaranteeing.
Other comparable grades utilized for PCBs consist Check out the post right here of FR2, which is a kind of fire retarding fiberglass resin bonded paper and G10 which is not flame resistant at all. FR2 is cheaper and so has its uses in mass production of low-end electrical equipment. G10, a predecessor to FR4, has actually all however been taken control of by the more secure FR4 standard. Its only use in PCBs now is in designs that prefer this combustible home.
This blog site has actually covered more information on rigid PCB materials than the average hobbyist will ever need, but must you ever discover the usage for High TG or more customized materials, you can take a look at Speed Fusion Advanced PCB service for more options including high-frequency boards and rigid-flex PCBs.
The FR4 option on the PCB order page is the grade classification for the epoxy fiberglass that frequently forms the PCB core and prepreg layers. In a common PCB, the core provides the rigidness and the structure on which the PCB traces can be 'printed' onto. For double layer boards, an FR4 core separates the top and bottom copper layers whereas, in multilayer PCBs, additional layers of FR4 prepreg are sandwiched in between the inner core and the external copper 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.