The FPC flexible circuit boards that are common in the market today are diverse. Single-sided cardboard, fr4 single-sided, double-sided, multi-layer board, single-sided aluminum substrate, single-sided fpc, high-frequency board, etc. Surface treatment process: over rosin, osp, spray tin, lead-free spray tin, gold plating, immersion gold, sinking silver.
For FPC, the polyimide protective film functions the same as the solder mask of the FR4-based printed circuit board (PCB). Polyimide is typically 12 to 25 microns thick and is coated with a pressure sensitive adhesive and attached to a paper based material. The key challenge is to ablate the pattern at high speed in the polyimide while avoiding thermal effects such as binder melting and paper-based combustion/carbonization. The most advanced protective film mapping process today combines a pulsed nanosecond UV laser with a two-dimensional galvanometer to achieve high speed machining with very low thermal effects. However, in some applications, quality is critical, so the UV picosecond pulse width is more favorable.
Compared to nanosecond UV lasers, picosecond UV lasers produce fewer fragments and are capable of processing at higher pulse frequencies (and thus at higher speeds) without causing defects in the binder and paper substrate. The necessary thermal effects.
Ultra-fast laser UV picosecond laser cutting machine is available for processing a wide range of FPC materials. Materials processed include polyimide-based protective films (25 μm thick polyimide + adhesive layer on paper), copper/liquid crystal polymer/copper (Cu/LCP/Cu) laminates, and exposed liquid crystal polymerization (LCP) material. LCP is an important dielectric material for high speed radio frequency (RF) data transmission technology.
In many cases, shorter ultraviolet (UV) wavelengths bring additional benefits. Shorter wavelengths allow for smaller focused spots and longer depth of field. In addition, the UV wavelength couples laser energy into a wider variety of materials than infrared wavelengths. One of the industries that combines many different materials is flexible printed circuit (FPC) manufacturing. Therefore, the realization of high-quality flexible circuit board processing by UV picosecond laser cutting machine is undoubtedly a better solution. Thereby greatly improving the quality and output of laser processing.