In commercial production, there are two laser technologies available for laser drilling. The wavelength of CO2 laser is in the far-infrared band, and the wavelength of ultraviolet laser is in the ultraviolet band. CO2 laser is widely used in the production of industrial micro through-holes on printed circuit boards, with a requirement that the diameter of the micro through-hole be greater than 100 μ (Raman, 2001). For the production of these large aperture holes, CO2 laser has high productivity because the punching time required for CO2 laser to produce large holes is very short. UV laser technology is widely used in diameters less than 100 μ In the production of micro pores in m, with the use of miniaturized circuit diagrams, the pore size can even be less than 50 μ M. Ultraviolet laser technology in the production of diameters less than 80 μ The yield of m holes is very high. Therefore, in order to meet the increasing demand for microporous productivity, many manufacturers have begun to introduce dual head laser drilling systems- The following PCB sample manufacturers have compiled three main types of dual head laser drilling systems used in the current market:

　　1) Double headed ultraviolet drilling system;

　　2) Double headed CO2 laser drilling system;

　　3) Stick laser drilling system (CO2 and UV).

　　All these types of drilling systems have their own advantages and disadvantages. Laser drilling systems can be simply divided into two types: dual drill single wavelength systems and dual drill dual wavelength systems. Regardless of the type, there are two main factors that affect the drilling ability:

　　1) Laser energy/pulse energy;

　　2) Beam positioning system.

　　The energy of the laser pulse and the transmission efficiency of the beam determine the drilling time, which refers to the time it takes for the laser drilling machine to drill a micro through hole. The beam positioning system determines the speed of movement between the two holes. These factors collectively determine the speed at which laser drilling machines can produce micro through-holes with given requirements. The dual head ultraviolet laser system is suitable for use in integrated circuits up to 90 μ The drilling of m is also characterized by a high aspect ratio.

　　The dual head CO2 laser system uses a Q-switched RF excited CO2 laser. The PCB sampling manufacturer tells you that the main advantages of this system are high repeatability (up to 100kHz), short drilling time, and wide operating surface. It only requires a few shots to drill a blind hole, but its drilling quality will be relatively low.