Terms and Definitions

Before proceeding we should define terms and also state some underlying assumptions

Droplet Diameter — The diameter of the ink droplet after it has hit the substrate and spread out. This value is used for two purposes: 1) to produce a simulation of droplet converage; 2) to offset the position of the droplet center so that the droplet falls completely inside of the line or pad to be imaged.

Droplet Pitch — The center to center spacing between droplets. This pitch can be described either as an absolute distance or as a percentage. The droplet pitch essentially defines the ink coverage.

Grid — The grid is both the database address of the bitmap and the physical positioning limits of the ink jet system. For example, consider a system that operates at 5080 DPI which is equivalent to a 5 um grid. This means that one can “place” a droplet on a 5 um grid and only on those 5 um grid points.

Edge Offset — the distance from the edge of a figure to the center of the droplet. By default we will offset the droplet position by 1/2 of its diameter so that no part of it “leaks” out. However there are forced tradeoffs between where one would like to place the droplet and where one can place the droplet.