A workpiece is electrostatically coated by an internal-voltage-application-type rotary atomizing electrostatic coating apparatus. An electrically conductive paint is supplied to the internal-voltage-application-type rotary atomizing electrostatic coating apparatus, and a voltage applied to the internal-voltage-application-type rotary atomizing electrostatic coating apparatus is controlled depending on an area of the workpiece which is to be coated, for thereby varying a coated pattern width on the workpiece.

A rotary atomizer for a coating apparatus has a bell shaped body, e.g., a bell cup, having a cavity and a detachable flow control device, e.g., face cover, that substantially closes a portion of the cavity. The two-piece construction eases maintenance, such as cleaning, and the manufacturability since the inside the bell cup is easily accessible from the mouth (wider opening) of the bell cup. After the face cover is detached, it can be reused or discarded for a new one. The bell cup further has cleaning channels that can direct cleaning agent directly onto the outer surface of the bell cup, without any reservoir or the like that can accumulate coating material.

An apparatus for electrostatically coating a workpiece has an insulating separator valve mechanism for electrically separating a paint supply passage for supplying an electrically conductive paint to a coating gun, into a paint supply passage to which a high voltage will be applied and a paint supply passage to which no high voltage will be applied. The insulating separator valve mechanism has a first valve body connectable to said paint supply passage through a first on/off valve, and a second valve body connectable to said paint supply passage through a second on/off valve. While the first and second valve bodies are connected to each other and the first and second on/off valves are closed, a paint trap is cleaned by a cleaning medium, which is discharged into a second dump passage. A process of cleaning the paint trap for a paint color change is efficiently and reliably carried out to reliably remove paint residuals from the paint trap.

Methods and apparatus for the deposition of a source material (10) are disclosed. An atomizer (12) renders a supply of source material (10) into many discrete particles. A force applicator (14) propels the particles in continuous, parallel streams of discrete particles. A collimator (16) controls the direction of flight of the particles in the stream prior to their deposition on a substrate (18). In an alternative embodiment of the invention, the viscosity of the particles may be controlled to enable complex depositions of non-conformal or three-dimensional surfaces. The invention also includes a wide variety of substrate treatments which may occur before, during or after deposition. In yet another embodiment of the invention, a virtual or cascade impactor may be employed to remove selected particles from the deposition stream.

Apparatuses and processes for maskless deposition of electronic and biological materials. The process is capable of direct deposition of features with linewidths varying from the micron range up to a fraction of a millimeter, and may be used to deposit features on substrates with damage thresholds near 100.degree. C. Deposition and subsequent processing may be carried out under ambient conditions, eliminating the need for a vacuum atmosphere. The process may also be performed in an inert gas environment. Deposition of and subsequent laser post processing produces linewidths as low as 1 micron, with sub-micron edge definition. The apparatus nozzle has a large working distance--the orifice to substrate distance may be several millimeters--and direct write onto non-planar surfaces is possible.