Abstract: In screen printing for printing cream-like solder on a board 7 through through-holes of a mask plate 12, removal of the board 7 from a lower surface of the mask plate 12 is performed in such a manner that the board 7 is moved down at a first descending velocity V1 as a lower velocity during an initial stroke S1 of from a state where the removal of the board 7 starts to a state where the board 7 is removed from the mask plate 12 so that the distance between the upper surface of the board 7 and the lower surface of the mask plate 12 reaches a predetermined value set to be in a range of from a half to twice as large as the thickness of the mask plate 12, and that the board 7 is moved down at a second descending velocity V2 as a higher velocity after the initial stroke S1. Accordingly, even in the case where solder apt to vary according to the passage of time is used, good removability and stable print quality can be secured.

Abstract: In the screen printer for printing paste to the substrate through a pattern hole by abutting a mask plate on the substrate, the end face of a side end portion of the substrate 6 is nipped and held from its both sides by a clamper 7. A warp correcting portion 17 mounting a warp-correcting member 20 constructed by a plate-shaped resilient metal is arranged in the clamper 7. When the substrate 6 held to a substrate holding portion of a Z-axis table 4 is clamped, a free end portion 20b of the warp correcting member 20 is abutted on the upper face side of the side end portion 6a of the substrate 6, and the warp deformation of the substrate 6 is corrected by pressing the free end portion 20b downward. Thus, the warp deformation of the-substrate is corrected by a simple and cheap mechanism, and the clamp state can be reliably held.

Abstract: A test printing portion with a pattern dimension smaller than a minimum printing pattern dimension is formed on a substrate, and a printing state of this test printing portion is inspected after printing. Based on inspection results of the test printing portion, acceptability of the printing state of the entire substrate is judged. The test printing portion is created on a periphery of the substrate outside the printing pattern area or an unprinted space inside the printing pattern area. A detection device detects the test printing portion, and inspects its printing state. Based on the inspection results, the acceptability of the printing state of the entire substrate is judged. This enables the printing state to be easily inspected at low cost while securing a necessary decree of accuracy.

Abstract: Pattern holes are completely filled with paste. As a result, occurrence of defects is prevented, and an excellent printing performance is obtained, high speed screen printing is possible, and the printing efficiency is enhanced. By sliding in the running direction above the mask plate having pattern holes, this squeegee for screen print can print the paste supplied on the mask plate to the substrate through the mask plate. It includes a contacting portion for contacting with the surface of the mask plate, a filling portion disposed at the running direction side of the contacting portion, and an agitating portion disposed at the running direction side of the filling portion. The agitating portion has a function of rotating the paste by sliding. The filling portion has a function of filling the pattern holes with the paste along with the sliding motion. The paste applied in the pattern holes can be printed on the substrate.

Abstract: There is disclosed a solder paste screen printing apparatus and a solder paste screen printing method, in which a force of pressing of a squeegee can be adjusted delicately and accurately so as to effect the printing of solder paste with the optimum pressing force. A squeegee is connected to a lower end of a rod of a cylinder, and a load cell is provided above the rod. A first pressure and a second pressure are applied respectively to an upper chamber and a lower chamber of the cylinder. A load, applied to the load cell, is measured while varying the level of the first pressure, and the pressure measurement for the pressing force is effected in accordance with the measured load. In accordance with this result, the instruction pressure for the cylinder, which is necessary for obtaining the optimum pressing force, is determined, and then the printing of solder paste onto a substrate is started with this instruction pressure.