Flexible circuit
The evolution of SMD components was at its peak in the late 1980s, and some applications required a flexible substrate to mount the components, shrinking the device footprint and squeezing the circuit boards into a compact space.
Flex boards have the same setup as the regular PCB, but the mounting substrate is varied.
The flex boards must have a flexible material with high-temperature resistance, a rigid surface, and high thermal conductivity to replace the glass epoxy sheet.
Flex boards are designed with a small burst rather than regular exposure to sustain the soldering process and continue to work at room temperature.
The flex board materials are selected to resemble the material properties of the conductive layer closely.
Which is mostly copper, but in some extreme cases, a carbon film is also used.
A material that closely resembles the flex board is more resistant to the mechanical stress caused between the two layers.
![Flex board2.png](/sites/default/files/Flex%20board2.png)
Advantages of Flex Board
Flex boards are a crucial variable in the creation of wearable technology. The latest innovation in thin, wearable gadgets results from the evolution of flex board technology.
The significant advantage of the flex boards is the freedom of shape and orientation. Satellite uses the flex boards more to conceal the active circuitry inside a shielded layer.
Flex boards can also eliminate wires as they can be used as wires. These designs will have extended sides that can be crimped to a connector and are directly sold to the second PCB.
Flex boards are a lot less heavy than regular PCBs, making them ideal for lightweight applications.
Flex boards are also thinner than standard PCBs. They can also serve in harsh environments with a much lesser impact on the vibrations.
![Flex board3.png](/sites/default/files/Flex%20board3.png)
Disadvantages of Flex Board
The major disadvantage of flex boards is the manufacturing cost. Due to the difference in material properties, it also takes time to produce the flex boards.
![Flex board4.png](/sites/default/files/Flex%20board4.png)