What is FR-4 PCB material?
We've all heard the abbreviation FR4 being tossed about at some time when purchasing a PCB fab home, however what does it actually imply? 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.
More than likely, you will have seen FR4 as the standard alternative 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 provides the PCB the electrical isolation and mechanical strength needed to withstand 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, extra 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 adding or eliminating private laminates or utilizing laminates of various thicknesses. Normally, a 1.6 mm board will have 8 layers of fiberglass sheets, if we wanted a 0.8 mm board we can minimize the number 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 standard. You might have seen that on the Speed Fusion order page the FR4 alternative is followed by TG130. The TG refers to the transition glass temperature level-- the temperature level at which the glass-reinforced material will begin to deform and soften. For Fusion's standard boards this worth is 130 ° C, which is ample for the majority of applications. Special High TG materials can endure temperatures of 170-- 180 ° C and can be bought online utilizing the Advanced PCB service.
FR4 laminates owe their flame resistance due to its bromine material, a non-reactive halogen commonly used in industry for its flame slowing down 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 over by the much safer FR4 requirement. Its only usage in PCBs now remains in styles that desire this flammable residential or commercial property.
This blog has actually covered more info on stiff PCB materials than the typical enthusiast will ever need, but should you ever find the usage for High TG or more specific materials, you can have a look at Speed Fusion Advanced PCB service for more options including high-frequency boards and rigid-flex PCBs.
The FR4 alternative on the PCB order page is the grade classification for the epoxy fiberglass that typically forms the PCB click here core and prepreg layers. In a typical PCB, the core provides the rigidity 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 thicknesses are utilized in multilayer boards in which the FR4 board is utilized to disperse signals to other boards, in order to not increase the density of the PCB. Greater densities are used when high robustness of the PCB is required since a large PCB is designed.