What is FR-4 PCB material?
We've all heard the abbreviation FR4 being thrown about eventually when going shopping for a PCB fab house, but what does it in fact mean? And what implications does it have when picking a PCB material? This post will assist clear the fog and introduce some popular materials offered for stiff PCBs.
Most likely, you will have seen FR4 as the standard choice for little batch or prototype PCBs like in Speed Fusion. FR-4 refers to a grade of material instead of a material itself and has lots of sub gradings and types such as TG130, High TG, FR4-Rogers. The FR4 option on the PCB order page is the grade designation for the epoxy fiberglass that typically forms the PCB core and prepreg layers. It is the properties of this base that gives the PCB the electrical seclusion and mechanical strength needed to endure increasingly requiring applications.
In a normal PCB, the core provides the rigidity and the structure 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 external copper layers. The preferred last density of the PCB can be controlled by adding or eliminating specific laminates or using laminates of different thicknesses. For instance, normally, a 1.6 mm board will have 8 layers of fiberglass sheets, if we wanted a 0.8 mm board we can decrease 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 standard. You might have seen that on the Speed Fusion order page the FR4 option 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 soften and deform. For Fusion's standard boards this worth is 130 ° C, which is ample for most applications. Special High TG materials can endure temperature levels of 170-- 180 ° C and can be bought online utilizing the Advanced PCB service.
FR4 laminates owe their flame resistance due to its bromine content, a non-reactive halogen commonly used in market for its flame slowing down homes. This gives FR4 materials obvious advantages as a stock PCB material, particularly in prototyping where circuits are still in the preliminary screening phases and may be pushed to extremes. It is also a little guaranteeing if your soldering abilities are not Browse around this site up to requirement.
Other similar grades used for PCBs consist of 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 and so 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 more secure FR4 requirement. Its only usage in PCBs now is 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 have a look at 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 classification for the epoxy fiberglass that frequently forms the PCB core and prepreg layers. In a common PCB, the core offers the rigidity and the foundation on which the PCB traces can be 'printed' onto. For double layer boards, an FR4 core separates the bottom and leading copper layers whereas, in multilayer PCBs, extra layers of FR4 prepreg are sandwiched between the outer copper and the inner core layers. Typical thinner thicknesses are used 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. Higher thicknesses are used when high toughness of the PCB is needed due to the fact that a big PCB is designed.