Screen printing device and screen printing method

A screen printing device that abuts a substrate against a mask plate in which pattern holes are formed to print a paste, the screen printing device comprising:

• a substrate positioning unit that holds a substrate carried from an upstream side, and moves the substrate relatively in a horizontal direction and a vertical direction to position the substrate at a given position;
• a screen print unit that allows a squeegee to slide on the mask plate onto which the paste is supplied, to print the paste on the substrate through the pattern holes;
• an imaging unit that has two imaging optical axes of which imaging directions are upward and downward, respectively, and conducts mark imaging operation of imaging a substrate recognition mark and a mask recognition mark formed on the substrate and the mask plate, respectively;
• an imaging unit moving mechanism that moves the imaging unit in the horizontal direction with respect to the substrate and the mask plate;
• a recognition processing unit that subjects an imaging result in the mark imaging operation to recognition processing, thereby conducting mark recognition processing for detecting positions of the substrate recognition mark and the mask recognition mark;
• an optical axis calibration processing unit that detects relative positions of the imaging optical axes on a mask lower surface and a substrate upper surface which are imaging surfaces of the two imaging optical axes, respectively, by imaging two reference marks associated with the relative positions by the imaging unit, individually, and outputs the detected relative positions as inter-optical-axis relative position data;
• a surface correction data creation processing unit that obtains a position error of the imaging optical axes occurring on the imaging surfaces in the horizontal direction caused by the move of the imaging unit by the imaging unit moving mechanism, as a positional deviation in the horizontal direction which is specific to each of reference points set in an ordered array for a substrate area on which the substrate is held and a mask area on which a mask plate is installed, respectively, and outputs the obtained position error as surface correction data representing a local positional deviation state in each of surfaces of the substrate area and the mask area;
• and
• a substrate positioning control unit that controls the imaging unit, the imaging unit moving mechanism, and the recognition processing unit so as to execute the mark imaging operation and the mark recognition processing, and controls the substrate positioning unit on the basis of the inter-optical-axis relative position data, the surface correction data, and the result of the mark recognition processing to execute substrate positioning operation for positioning the substrate and the mask plate.