Flexible PCB and rigid PCB engineering technology
Flexible PCB is also called flexible circuit, flexible printed circuit board, flexible printed circuit, flexible circuit. They consist of a thin insulating polymer film on which conductive circuit patterns are fixed, and are usually provided with a thin polymer coating to protect the conductor circuit
*The similarities and differences between rigid PCB and flexible circuit
When designing a rigid PCB, certain design rules must be followed, including minimum hole size, minimum space and trace width, minimum distance to the board edge, copper and overall design thickness. In addition, many manufacturing process steps are shared between rigid and flexible PCBs. These process steps include drilling and plating of holes and through holes, optical imaging and development, etching of copper traces, pads, outlines and planes, and heating (baking) of circuit boards to remove moisture from the PCB. At this point in the manufacturing process, the rigid PCB leads to the solder mask workstation, while the flexible circuit is connected to the overlay workstation.
* Benefits of reduced size and weight for flexible circuits
Generally, flexible circuits are the preferred solution for the following manufacturers:
Suitable for wiring solutions that rigid boards cannot.
Thin and light product, but still durable.
A miniaturized version of the prior art.
Three-dimensional packaging geometry.
A small number of devices are interconnected.
Shock and vibration resistant.
These advantages indicate that flexible circuit options are ideal solutions for mobile consumer electronics. Sophisticated circuit board amateurs who disassemble smartphones or laptops will find rich and flexible circuits in any modern device on the market.
In the case of mobile devices, the use of rigid circuits can cause the device to be too large, too heavy, and too fragile to carry around. This is the case with the first full-power mobile computer Osborne I, which weighs at an astonishing weight of 24.5 pounds. However, the reduction in size and weight represents only half of the story of flexible circuits. They are also ideal for high temperature and high density applications.
*High temperature and high density applications
In many cases, flexible circuits are made of polyimide or similar polymers. This material dissipates heat better than most circuit board materials. For this reason, flexible circuits can be placed in inconvenient locations where heat can affect the performance of rigid circuit boards.
Flexible circuit boards can be designed to withstand extreme temperatures-between -200°C and 400°C, which explains why they are ideal for drilling measurements in the oil and gas industry. In fact, due to these conditions and the need for small, unobtrusive equipment in most industrial environments, flexible circuits represent the first choice for engineering design in most industrial sensor technologies. High temperature resistance usually has good chemical resistance and excellent radiation resistance and ultraviolet resistance. Combined with the ability to control impedance in high-density circuit board design, flexible circuit design provides manufacturers with many benefits.