The printed circuit board is applied in various electronics products.Its quality and stabilities decide the quality of the product directly.Printed circuit board(PCB) has important position in the electronics silk screen printing.In the PCB screening printing,the main function of the printing ink(such as the printing ink viscosity degree and thixotropy) affects the PCB printing quantity and production speed directly.Therefore,in printing the printing ink viscosity degree and thixotropy must be controlled to make better quality production.