Screen printing method and screen printing machine

A screen printing machine for printing a viscous fluid on a first circuit board and a second circuit board conveyed in each of two lanes through a screen, comprising:

• a squeegee device configured to include a pair of squeegees and move each of the pair of squeegees on the screen;
• a viscous fluid holding device configured to include two holding members capable of holding the viscous fluid and independently move each of the holding members;
• and
• a printing control device configured to
• control the squeegee device and the viscous fluid holding device to print a first viscous fluid which is the viscous fluid held by a first holding member that is one of the two holding members at a first start position on the first circuit board by moving a first squeegee which is one of the pair of squeegees from the first start position in a first direction,
• move the first holding member in the first direction below the first squeegee which is in a retracted position and move the first holding member to a first end position in front of the first squeegee,
• lower the first squeegee from the retracted position and move the first squeegee in the first direction toward the first holding member positioned at the first end position to load the first viscous fluid on the first holding member,
• hold the first viscous fluid by the first holding member at the first end position spaced apart from the first start position in the first direction, and
• print a second viscous fluid which is different from the first viscous fluid and held by a second holding member that is the other one of the two holding members at a second start position on the second circuit board by moving a second squeegee which is the other one of the pair of squeegees from the second start position in a second direction opposite to the first direction.