Laser cut polyimide

Under the background of the development of electronic products in the direction of high density, miniaturization and high reliability, flexible circuit boards (FPC) have become the ideal solution for the miniaturization and mobility of electronic products because of their features such as free bending, high wiring density and thin thickness. The only solution. There is a layer of resin film on the surface of FPC, which plays the role of line protection and solder mask. Its main component is polyimide (PI), also known as PI cover film in the industry. A class of polymers of imide rings (-CO-NH-CO-), among which polymers containing phthalimide structures are the most important. PI cover film has outstanding dielectric properties, mechanical properties, radiation resistance and wear resistance at high temperature, and is widely used in aviation, weapons, electronics, electrical appliances and other precision machinery.

With the development of laser technology, the use of UV laser to cut FPC and PI cover films gradually replaces traditional die cutting. Ultraviolet laser cutting is a non-contact processing, no expensive molds are required, and the production cost is greatly reduced. The focused spot can be only ten microns, which can meet the processing needs of high-precision cutting and drilling. This advantage is catering to the precision of circuit design. It is an ideal tool for FPC and PI film cutting.

The current UV laser cutting machines used in FPC and PI film cutting are mainly nanosecond solid-state UV lasers with a wavelength of 355nm. Compared with 1064nm infrared and 532nm green light, 355nm UV has higher single-photon energy and higher material absorption rate. high, resulting in less thermal impact and higher machining accuracy.