What is FR-1?
FR-1 is a paper-based non-conductive printed circuit board (PCB) base material made of phenol-formaldehyde resin and paper. The FR-1 is used in PCB laminates. PCB laminates are comparatively thin panels coated with copper. In a PCB laminate, the FR-1 works as an insulator that separates the two conducting layers and provides the necessary mechanical support to the circuit board.
The FR in FR-1 material stands for fire retardant, which is a property of a material to extinguish fire itself. Throughout their lives, the PCBs went through a lot of heat and even sometimes, the components get a spark and catch fire. Hence, in such circumstances, the fire-extinguishing property of FR-1 helps the circuit to prevent a huge loss and spread of fire. Along with excellent fire-handling capabilities, FR-1 has great electrical specifications and mechanical strength. That is why PCB producers still prefer FR-1 for their circuits and especially for single-side circuit boards.
What are the Benefits of FR-1 PCB?
FR-1 PCB material is a widely used PCB base material with several advantages.
Flame Retardant
FR-1 PCB material meets the standard of UL94V-0. Hence, FR-1 is a flame-retardant material that does not catch fire easily and extinguishes the fire itself. The flame retardancy of FR-1 material makes it suitable for consumer electronics such as chargers, adapters and other home appliances.
Low-Cost Material
FR-1 is a low-cost material with good electrical specifications that meet industry standards while aiding the budget. Further, FR-1, due to its electrical properties and low price, is the first choice of PCB engineers for single-layer PCBs.
Good Glass Transition Temperature Tg of FR-1
FR-1 provides a glass transition value of 130C, which is not soo high and, of course, less than the glass transition value of FR-4 (150C to 170C). Firstly, the transition temperature of a PCB base material defines the temperature at which the PCB starts getting soft and losing its shape. But still, with a lower Tg than FR-4, FR-1 provides exceptional performance in his applications. The applications of FR-1 PCB material are not complex a lot. Hence, a glass transition temperature of 130C is enough to meet the criteria of its applications.
What are the Drawbacks of FR-1 PCB?
Every matter present in the universe, along with its benefits, has some drawbacks; that may limit its use but never question its reliability and performance in the right places. The widely used PCB material FR-1 also has some disadvantages and limitations that restrict its use for some specific applications.
To understand the FR-1 PCB specifications and their behaviour deeply. It is significant to pay attention to its limitations. So, let's have a look at the drawbacks of FR-1 PCB material.
Lower Temperature Resistance
FR-1 is not a good base material for circuit boards that produce ample heat during operation and require high-temperature resistance. As stated above, the Glass transition temperature value of FR-1 PCB material is 130C. Hence, if the device generates a lot of heat, gradually, the PCB will start losing its shape and experience electrical and physical damage.
The Difference Between FR-1, FR-2, FR-3, FR-4
FR-1, FR-2, FR-3 and FR-4 all come under Flame-Retardent NEMA-graded materials. All four are significant PCB dielectric materials with good electrical specifications. The family members of Flame Retardent material have different specifications, which proves them better than each other for specific applications. Hence, we should know the differences between these materials to pick the best possible material for our project. To ease your learning about the family of flame-retardent material, NextPCB provides a chart that significantly covers basic to advance knowledge about all four materials.
