GB2446663A

GB2446663A - Effector module and system for use with a screen printing machine

Info

Publication number: GB2446663A
Application number: GB0706086A
Authority: GB
Inventors: Charles Moncavage
Original assignee: DEK International GmbH
Current assignee: ASM Assembly Systems Switzerland GmbH
Priority date: 2007-02-15
Filing date: 2007-03-29
Publication date: 2008-08-20
Also published as: GB0706086D0; WO2008098736A3; WO2008098736A2

Abstract

An effector module 203 for use with a screen printing machine which includes a frame support for supporting a mounting frame of a printing screen unit, the effector module comprising: a mounting frame 210, which is configured to replace the mounting frame of the printing screen unit and provide for mounting of the effector module in the frame support of the screen printing machine; a support member, which extends from the mounting frame; an attachment member 211 to which an end effector 212 is removably attached; and a positioning mechanism which is mounted to the support member 205 and connected to the attachment member, such as to provide for positioning of the attachment member in an X-Y plane. The effector may be a fluid dispensing effector, eg. For dispensing adhesive, solder flux or paste, in a desired pattern, or an ink jetting or laser etching effector.

Description

EFFECTOR MODULE AND SYSTEM FOR USE WITH A SCREEN

PRINTING MACHINE

The present invention relates to an effector module and system for use with a screen printing machine, in particular a surface mount technology (SMT) screen printing machine, which provides for flexible operation of the screen printing machine, in allowing for use with any of a plurality of end effectors, such as a fluid-dispensing effector, an ink-jetting effector, a component-mounting effector and a laser-etching effector.

Conventionally, an SMT assembly line includes a plurality of dedicated machines, which separately perform the operations required in an SMT process, including a screen printing machine for performing a screen printing operation.

Figure 1 illustrates one such conventional screen printing machine. Such screen printing machines are supplied, for example, by DEK INTERNATIONAL GMBt-I (Zurich, Switzerland), EKRA AUTOMATISIERUNGSSYSTEME GMBH (Bonningheim, Germany) and SPEEDLINE TECHNOLOGIES, INC. (Franklin, MA, USA).

The screen printing machine comprises a frame support 103 which supports a printing screen unit 105, which comprises a mounting frame 107 and a printing screen 109 which is mounted thereto, and a print head 111 which is movable back and forth across the printing screen 109 to drive printing material, such as solder paste, through a pattern of apertures in the printing screen 109 and onto a workpiece disposed therebeneath.

The screen printing machine further comprises a workplece support which Is disposed beneath the printing screen 109 to support a workplece at a printing zone, and a workpiece transport mechanism 114 whIch includes a pair of transport rails 115, 117 along which workpieces are transported to and from the workpiece support.

The screen printing machine further comprises an alignment mechanism 121 for aligning the printing screen unit 105 relative to the workpiece support, such as to align the printing screen 109 relative to a workpiece as supported therebeneath. In this embodiment the alignment mechanism 121 comprises an imaging unit for capturing images of fiducials on the printing screen 109 and the workpiece, and an alignment unit, in this embodiment an X-X-Y table, for X, V and e alignment of the printing screen unit 105 relative to the workpiece support in response to the imaged fiducials.

The screen printing machine further comprises a controller 131 for controlling operation of the screen printing machine.

The present inventor has recognized that a screen printing machine can be utilized to provide any number of further operations through the utilization of an effector module in place of the printing screen unit.

This use of a screen printing machine advantageously allows for the extended use of an under-used screen printing machine, and also avoids the need for a dedicated piece of equipment to perform an operation which may be required infrequently. Such equipment is both expensive and requires the allocation of floorspace, which may be better utilized.

In one aspect the present invention provides an effector module for use with a screen printing machine, which includes a frame support for supporting a mounting frame of a printing screen unit, the effector module comprising: a mounting frame, which is configured to replace the mounting frame of the printing screen unit and provide for mounting of the effector module in the frame support of the screen printing machine; a support member, which extends from the mounting frame; an attachment member to which an end effector is in use attached; and a positioning mechanism which is connected to the attachment member and operable to provide for positioning of the attachment member in an X-Y plane.

In one embodiment the mounting frames of the printing screen unit and the effector module are rectangular.

In one embodiment the mounting frames of the printing screen unit and the effector module are of the same size.

In one embodiment the support member includes an aperture beneath which a workpiece, as supported on a workpiece support of the screen printing machine, is located.

In one embodiment the positioning mechanism comprises first and second positioning units, which provide for positioning of the attachment member in respective ones of orthogonal, X-Y axes, such as to be operable together to provide for positioning of the attachment member in the X-Y plane.

In one embodiment one, first positioning unit comprises first and second positioners, which are mounted in parallel relation to the support member, a bridge member, which interconnects the first and second positioners and Is moved by common operation of the same, and at least one actuator for actuating the positioners, such as to position the attachment member in one axis.

In one embodiment the first positioning unit comprises a single actuator.

In one embodiment the first and second positioners each comprise a guide, a carriage which is slideably disposed on the guide, and a drive unit which is operable to move the carriage along a length of the guide.

In one embodiment the guide comprises a linear bearing.

In one embodiment the carriage includes a screw-threaded element which extends parallel to the guide, and the drive unit comprises first and second bearing blocks which are disposed to opposite ends of the guide and mounted to the support member, and a leadscrew, which extends through the screw-threaded element of the carriage and is rotatably supported at opposite ends thereof by respective ones of the bearing blocks, such that the carriage is moved along the guide by rotation of the leadscrew, with movement of the carriage in opposite directions being achieved by rotation of the leadscrew in one of a clockwise or counter-clockwise sense.

In one embodiment the first positioning unit includes a first drive element, which commonly couples the drive units of the first and second positioners, such that the first and second positioners are commonly driven.

In one embodiment the first drive element comprises a belt.

In one embodiment the first positioning unit includes a second drive element, which is coupled to the drive unit of one of the first and second positioners and the at least one actuator, such that operation of the at least one actuator causes the drive units of the first and second positioriers to be driven simultaneously.

In one embodiment the second drive element comprises a belt.

In one embodiment the at least one actuator comprises one of a stepping motor or a servo motor, which allows for positioning of the carriages, and hence the end effector, in the one axis.

In one embodiment the other, second positioning unit comprises a positioner, which is mounted to the bridge member of the first positioning unit in orthogonal relation to the guides of the first and second positioners thereof, and an actuator for actuating the positioner, such as to position the attachment member in the other, orthogonal axis.

In one embodiment the positioner comprises a guide, which is mounted to the bridge member of the first positioning unit, a carriage which is slideably disposed on the guide, and a drive unit which is operable to move the carriage along a length of the guide.

In one embodiment the guide comprises a linear bearing.

In one embodiment the carriage includes a screw-threaded element which extends parallel to the guide, and the drive unit comprises first and second bearing blocks which are disposed to opposite ends of the guide, and a Ieadscrew, which extends through the screw-threaded element of the carriage and is rotatably supported at opposite ends thereof by respective ones of the bearing blocks, such that the carriage is moved along the guide by rotation of the leadscrew, with movement of the carriage in opposite directions being achieved by rotation of the leadscrew in one of a clockwise or counter-clockwise sense.

In one embodiment the second positioning unit includes a drive element, which is coupled to the leadscrew of the positioner and the actuator, such that operation of the actuator causes rotation of the Ieadscrew.

In one embodiment the drive element comprises a belt.

In one embodiment the actuator comprises one of a stepping motor or a servo motor, which allows for positioning of the carriage, and hence the end effector, In the other axis.

In one embodiment the effector module further comprises: an end effector which is in use attached to the attachment member.

In one embodiment the end effector is a fluid-dispensing effector for dispensing deposits, typically of a viscous material, such as an adhesive, a solder flux or a solder paste, from a reservoir onto a workpiece, in a desired pattern, with the fluid-dispensing effector being controlled to dispense fluid deposits in dependence of the movement thereof.

In another embodiment the end effector is an ink-jetting effector for delivering a liquid to a workpiece in a desired pattern.

In a further embodiment the end effector is a component-mounting effector for mounting components at defined locations on a workpiece.

In a yet further embodiment the end effector is a laser-etching effector for laser etching a desired pattern in a workpiece.

in another aspect the present invention provides an effector module for use in a screen printing machine in place of a printing screen unit, the effector module comprising: a body which provides for mounting of the effector module in the screen printing machine; an attachment member to which an end effector is in use attached; and a positioning mechanism which is mounted to the body and connected to the attachment member, such as to provide for positioning of the attachment member relative to a workpiece which is in use supported by the screen printing machine.

In one embodiment the effector module further comprises: a control interface for interfacing the effector module to a controller, such as to achieve a desired operation of the effector module In accordance with control sIgnals.

In one embodiment the control interface is mounted to the support member or the body.

In one embodiment the effector module is provided as a single, integral unit.

In a further aspect the present invention provides an effector system for use with a screen printing machine which includes a frame support for supporting a mounting frame of a printing screen unit, the effector system comprising: the above-described effector module.

In one embodiment the effector system further comprises: a dedicated controller, which is connected to the control interface for controlling operation of the effector module.

In one embodiment the controller comprises a PC-based controller having a user interface.

In one embodiment the control signals are provided in a programmed routine.

In one embodiment the controller provides at least in part for automatic control of the effector module.

In one embodiment the controller provides for automatic control of the effector module.

In one embodiment the controller provides at least in part for manual control of the effector module.

In one embodiment the controller provides for manual control of the effector module.

In another embodiment the control interface is directly connected to the controller of the screen printing machine.

In a yet further aspect the present invention provides a method of operating a screen printing machine with the above-described effector system, the method comprising the steps of: loading the effector module into the frame support of the screen printing machine; locating a workpiece on a workpiece support adjacent the effector module; imaging fiducials on the workpiece and the effector module; aligning the effector module relative to the workplece using the fiducials as Imaged on the workpiece and the effector module; and operating the effector module in accordance with a control routine, such that the end effector performs a required operation on the In a still further aspect the present invention provides a method of operating a screen printing machine with an effector system, which comprises an effector module comprising a mounting frame for mounting the effector module in a frame support of the screen printing machine, an attachment member to which an end effector is attached and a positioning mechanism which is connected to the attachment member and operable to provide for positioning of the end effector relative to a workpiece as supported by the screen printing machine, the method comprising the steps of: loading the effector module into the frame support of the screen printing machine; locating a workpiece on a workpiece support adjacent the effector module; imaging fiducials on the workpiece and the effector module; aligning the effector module relative to the workpiece using the fiducials as imaged on the workpiece and the effector module; and operating the effector module in accordance with a control routine, such that the end effector performs a required operation on the workpiece.

In one embodiment the effector module loading step comprises the step of: loading the effector module into the frame unit of the screen printing machine in place of a printing screen unit.

In one embodiment the method further comprises the step of: fitting an end effector to the attachment member prior to loading the effector module into the frame support.

In another embodiment the method further comprises the step of: fitting an end effector to the attachment member subsequent to loading the effector module into the frame support.

In one embodiment the workpiece locating step comprises the step of: locating a workpiece on a workpiece support beneath the effector module.

In one embodiment the workpiece locating step is performed automatically.

In another embodiment the workpiece locating step is performed manually.

In one embodiment the imaging step is performed automatically.

In another embodiment the imaging step is performed manually.

In one embodiment the imaging step comprises the step of: imaging fiducials on the workpiece and the end effector.

In one embodiment the alignment step provides for alignment of the effector module relative to the workpiece, such as to establish common X and Y axes and a datum for the end effector.

In one embodiment the alignment step comprises the step of: moving the effector module in relation to the workpiece support, such as to align the effector module relative to the workpiece.

In another embodiment the alignment step comprises the step of: moving the workpiece support in relation to the effector module, such as to align the effector module relative to the workpiece.

In one embodiment the effector module operating step is performed automatically in response to a command signal from the controller of the screen printing machine.

-10 -In one embodiment the command signal corresponds to a print command signal which normally operates the print head of the screen printing machine.

In another embodiment the effector system further comprises a dedicated controller for controlling operation of the effector module, and the effector module operating step is performed automatically in response to a command signal from the dedicated controller.

In one embodiment the method further comprises the step of: programming the dedicated controller with a control routine for controlling operation of the effector module.

In one embodiment the programming is performed off-line, such as at a docking station.

In another embodiment the programming is performed with the effector module In situ.

In a further embodiment the effector module operating step is actuated manually.

In one embodiment the workpiece is a printed circuit board.

A preferred embodiment of the present invention will now be described hereinbelow by way of example only with reference to the accompanying drawings, in which: Figure 1 illustrates a perspective view of a conventional screen printing machine, with a printing screen unit loaded therein; -11 -Figure 2 illustrates a perspective view from above of an effector system in accordance with a preferred embodiment of the present invention, with an end effector fitted to the effector module thereof; Figure 3 illustrates a part-exploded perspective view of the effector module of the effector system of Figure 2, with the end effector removed therefrom; Figure 4 illustrates a flow chart for the operation of the effector system of Figure 2 when used in the screen printing machine of Figure 1; and Figure 5 illustrates the screen printing machine of Figure 1 having the effector system of Figure 2 loaded therein in place of the printing screen unit.

The effector system comprises an effector module 203 and a controller 204 for controlling operation of the effector module 203.

The effector module 203 comprises a main, support member 205 and a frame element 207, in this embodiment of rectangular shape, which is fixed to the outer edge of the support member 205, in this embodiment by supporting pillars 209, and together define a mounting frame 210, which is configured to replace the stencil frame in a screen printing machine, such as described hereinabove. In this embodiment the mounting frame 210 corresponds to the conventional stencil frame size for a 29" wide stencil, but it will be understood that the mounting frame 210 can have any dimension which allows for mounting in a screen printing machine.

The effector module 203 further comprises an end effector attachment member 211 to which an end effector 212 is removably attached, and a positioning mechanism 215 which is mounted to the support member 205 and connected to the attachment member 211, such as to provide for positioning of the attachment member 211 in an X-Y plane.

-12 -In this embodiment the support member 205, as a rectangular plate, includes an aperture 217, which in use is located over a workpiece, such as a printed circuit board, which is supported on the workpiece support of the screen printing machine.

In this embodiment the positioning mechanism 215 comprises first and second positioning units 219, 221, which provide for positioning of the attachment member 211 in respective ones of orthogonal, X-Y axes, such as to be operable together to provide for positioning of the attachment member 211, and hence the end effector 212, in the X-Y plane.

In this embodiment the first positioning unit 219, here a Y-axis positioning unit, comprises first and second V-axis positioners 223, 225, which are mounted in parallel relation to the support member 205 on opposite sides of the aperture 217 therein, a bridge member 226, which interconnects the first and second Y-axis positioners 223, 225 and is moved by common operation of the same, and at least one, in this embodiment a single actuator 227 for actuating the V-axis positioners 223, 225, such as to position the attachment member 211, and hence the end effector 212, in the V-axis.

In this embodiment, as particularly illustrated in Figure 3, the V-axis positioners 223, 225 each comprise a guide 231, in this embodiment a linear bearing, which extends along a respective edge of the aperture 217 in the support member 205, a carriage 233 which is slideably disposed on the guide 231, and a drive unit 235 which is operable to move the carriage 233 along the length of the guide 231.

In this embodiment the carriage 233 includes a screw-threaded element 237, typically in the form of a threaded nut element, which extends parallel to the guide 231 and is configured to receive a leadscrew 245, as will be described in more detail hereinbelow.

-13 -In this embodiment the drive unit 235 comprises first and second bearing blocks 241, 243 which are disposed to opposite ends of the guide 231 and mounted to the support member 205, and a leadscrew 245, which extends through the screw-threaded element 237 of the carriage 233 and is rotatabiy supported at opposite ends thereof by respective ones of the bearing blocks 241, 243, such that the carriage 233 is moved along the guide 231 by rotation of the leadscrew 245, with movement of the carriage 233 in opposite directions being achieved by rotation of the leadscrew 245 in one of a clockwise or counter-clockwise sense.

In this embodiment the V-axis positioning unit 219 includes a first drive element 247, in this embodiment a belt, here a toothed belt, which commonly couples the leadscrews 245 of the Y-axis positioners 223, 225, such that the V-axis positioners 223, 225 are commonly driven.

In this embodiment the V-axis positioning unit 219 includes a second drive element 249, in this embodiment a belt, here a toothed belt, which is coupled to the leadscrew 245 of one of the Y-axis positioners 223, 225, here the second V-axis positioner 225, and the actuator 227, such that operation of the actuator 227 causes the leadscrews 245 of the V-axis positioners 223, 225 to be driven simultaneously.

In this embodiment the leadscrews 245 of the V-axis positioners 223, 225 each include a pulley 251, here a toothed pulley, to which the first drive element 247 is coupled, and the leadscrew 245 of one of the V-axis positioners 223, 225, here the second, V-axis positioner 225, includes a second pulley 253, here a toothed pulley, to which the second drive element 249 is coupled.

In this embodiment the actuator 227 comprises one of a stepping motor or a servo motor, which allows for highly-accurate positioning of the carriages 233, and hence the end effector 212 as supported by the bridge member 226 which interconnects the carriages 233, in the V-axis.

-14 -In this embodiment the support member 205 includes first and second recesses 255, 257 in which respective ones of the V-axis positioners 223, 225 are disposed.

In this embodiment, as particularly illustrated in Figure 3, the second positioning unit 221, here an X-axis positioning unit, comprises an X-axis positioner 261, which is mounted to the bridge member 226 of the V-axis positioning unit 219 in orthogonal relation to the guides 231 of the V-axis positioners 223, 225, and an actuator 263 for actuating the X-axis positioner 261, such as to position the attachment member 211, and hence the end effector 212, in the X-axis.

In this embodiment the X-axis positioner 261 comprises a guide 265, in this embodiment a linear bearing, which is mounted to the bridge member 226 of the V-axis positioning unit 219, a carriage 267 which is slideably disposed on the guide 265, and a drive unit 269 which is operable to move the carriage 267 along the length of the guide 265.

In this embodiment the carriage 267 includes a screw-threaded element 271, typically in the form of a threaded nut element, which extends parallel to the guide 265 and is configured to receive a leadscrew 277, as will be described in more detail hereinbelow.

In this embodiment the drive unit 269 comprises first and second bearing blocks 273, 275 which are disposed to opposite ends of the guide 265, and a Ieadscrew 277, whIch extends through the screw-threaded element 271 of the carriage 267 and is rotatably supported at opposite ends thereof by respective ones of the bearing blocks 273, 275, such that the carriage 267 is moved along the guide 265 by rotation of the leadscrew 277, wIth movement of the carriage 267 in opposite directions being achieved by rotation of the teadscrew 277 in one of a clockwise or counter-clockwise sense.

-15 -In this embodiment the X-axis positioning unit 221 includes a drive element 279, in this embodiment a belt, here a toothed belt, which is coupled to the leadscrew 277 of the X-axis positioner 261, and the actuator 263, such that operation of the actuator 263 causes rotation of the leadscrew 277.

In this embodiment the actuator 263 comprises one of a stepping motor or a servo motor, which allows for highly-accurate positioning of the carriage 267, and hence the end effector 212, in the X-axis.

In this embodiment the end effector 212 is a fluid-dispensing effector for dispensing deposits, typically of a viscous material, such as an adhesive, a solder flux or a solder paste, from a reservoir onto a workpiece, such as a printed circuit board, in a desired pattern, with the fluid-dispensing effector being controlled to dispense liquid deposits in dependence of the movement thereof.

In alternative embodiments the end effector 212 could be any other kind of effector for operating in relation to a workpiece, including but not limited to an ink-jetting effector for delivering a liquid to a workpiece in a desired pattern, a component-mounting effector for mounting components at defined locations on a workpiece and a laser-etching effector for laser etching a desired pattern in a workpiece.

The effector module 203 further comprises a control interface 281 for interfacing the effector module 203, and in particular the end effector 212 and the positioning mechanism 215, with the controller 204, such as to achieve a desired operation of the end effector 212, in accordance with control signals, typically as provided in a programmed routine. In this embodiment the control interface 281 is mounted on the support member 205, such that the effector module 203 comprises a single, integral unit.

-16 -In this embodiment the controller 204, here based on a PC system having a user interface, is connected to the control interface 281 for controlling the operation of the effector module 203, typically automatically in accordance with a programmed routine. In an alternative embodiment the controller 204 could allow for manual control of the effector module 203. In this embodiment, by having a dedicated controller 204, little or no modification is required to the screen printing machine.

In an alternative embodiment the control interface 281 could be directly connected to the controller 131 of the screen printing machine, thereby avoiding the need for the dedicated, separate controller 204.

Operation of the effector system will now be described hereinbelow with reference to Figures 4 and 5 of the accompanying drawings.

In a first step (Step Si), the controller 204 is programmed with a control routine for controlling the operation of the effector module 203, and in particular the operation of the end effector 212 in conjunction with the movement thereof. In this embodiment the programming is performed off-line, such as at a docking station. In an alternative embodiment the programming could be performed with the effector module 203 in situ.

In a second step (Step S2), the effector module 203 is loaded into the frame support 103 of the screen printing machine in place of the printing screen unit 105, as illustrated in Figure 5. In this embodiment the required end effector 212 is fitted to the attachment member 211 of the effector module 203 prior to loading the effector module 203 into the frame support 103. In an alternative embodiment the required end effector 212 could be fitted to the attachment member 211 of the effector module 203 subsequent to loading the effector module 203 into the frame support 103.

In a third step (Step S3), a workpiece, such as a printed circuit board, is transported by the workpiece transport mechanism 114 to a location above -17 -the workpiece support, corresponding to a location beneath the aperture 217 in the support member 205. In this embodiment workpieces are automatically transported in succession in accordance with the normal control routine of the screen printing machine. In an alternative embodiment the screen printing machine could be manually operated to transport workpieces in succession to a location above the workpiece support.

In a fourth step (Step S4), the workpiece support is actuated to support the workpiece as located thereabove by the workpiece transport mechanism 114. In this embodiment the workpiece support is operated automatically in accordance with the normal control routine of the screen printing machine.

In an alternative embodiment the workpiece support could be operatedmanually.

In a rfth step (Step 55), the imaging unit is operated to capture fiducials both on the workpiece and the effector module 203, in this embodiment including fiducials on the end effector 212. In this embodiment the imaging unit is operated automatically in accordance with the normal control routine of the screen printing machine. In an alternative embodiment the imaging unit could be operated manually.

In a sixth step (Step S6), the alignment unit is operated to align the effector module 203 relative to the workpiece, such as to establish common X-Y axes and a 0, 0 datum for the end effector 212. In this embodiment the effector module 203 is moved in relation to the workpiece support, such as to align the effector module 203 relative to the workpiece. In an alternative embodiment the workpiece support is moved in relation to the effector module 203, such as to align the effector module 203 relatIve to the In a seventh step (Step S7), the effector module 203 is operated in accordance with the pre-programmed routine, such that the end effector -18 - 212 performs the required operation on the workpiece. In this embodiment the effector module 203 is actuated automatically by a command signal from the controller 131 of the screen printing machine, which is normally the print command signal to operate the print head 111. This mode of operation requires only a simple modification to the control software for the screen printing machine to inhibit the normal print cycle and control operation of the effector module 203. in an alternative embodiment the effector module 203 could be actuated manually by operation of the controller 204.

In an eighth step (Step S8), the workpiece support is operated to return the workpiece to the workpiece transport mechanism 114. In this embodiment the workpiece support is actuated automatically by a command signal from the controller 204, which indicates completion of the operative cycle of the effector module 203. In an alternative embodiment the workpiece support could be operated manually.

In a ninth step (Step S9), the workpiece transport mechanism 114 is operated to transport the workpiece from the screen printing machine in accordance with the normal control routine. In this embodiment the workpiece transport mechanism 114 is actuated automatically. In an alternative embodiment the workpiece transport mechanism 114 could be operated manually.

This operation is then repeated for each workpiece to be processed using the effector module 203.

Finally, it will be understood that the present invention has been described in its preferred embodiment and can be modified in many different ways without departing from the scope of the invention as defined by the appended claims.

-19 -In one modification, the positioners 223, 225, 261 could utilize drive elements other than the leadscrews 245, 277, such as drive belts, for example, toothed belts.

In another modification, the positioners 223, 225, 261 and associated actuators 227, 261 could be replaced by linear motors.

Claims

-20 - CLAIMS

1. An effector module for use with a screen printing machine, which includes a frame support for supporting a mounting frame of a printing screen unit, the effector module comprising: a mounting frame, which is configured to replace the mounting frame of the printing screen unit and provide for mounting of the effector module in the frame support of the screen printing machine; a support member, which extends from the mounting frame; an attachment member to which an end effector is in use attached; and a positioning mechanism which is connected to the attachment member and operable to provide for positioning of the attachment member in an X-Y plane.

2. The effector module of claim 1, wherein the mounting frames of the printing screen unit and the effector module are rectangular.

3. The effector module of claim 2, wherein the mounting frames of the printing screen unit and the effector module are of the same size.

4. The effector module of any of claims 1 to 3, wherein the support member includes an aperture beneath which a workpiece, as supported on a workpiece support of the screen printing machine, is located.

5. The effector module of any of claims 1 to 4, wherein the positioning mechanism comprises first and second positioning units, which provide for positioning of the attachment member in respective ones of orthogonal, X-Y axes, such as to be operable together to provide for positioning of the attachment member in the X-Y plane.

-21 -

6. The effector module of claim 5, wherein one, first positioning unit comprises first and second positioners, which are mounted in parallel relation to the support member, a bridge member, which interconnects the first and second positioners and is moved by common operation of the same, and at least one actuator for actuating the positioners, such as to position the attachment member in one axis.

7. The effector module of claim 6, wherein the first positioning unit comprises a single actuator.

8. The effector module of claim 6 or 7, wherein the first and second positioners each comprise a guide, a carriage which is slideably disposed on the guide, and a drive unit which is operable to move the carriage along a length of the guide.

9. The effector module of claim 8, wherein the guide comprises a linear bearing.

10. The effector module of claim 8 or 9, wherein the carriage includes a screw-threaded element which extends parallel to the guIde, and the drive unit comprises first and second bearing blocks which are disposed to opposite ends of the guide and mounted to the support member, and a eadscrew, which extends through the screw-threaded element of the carriage and is rotatably supported at opposite ends thereof by respective ones of the bearing blocks, such that the carriage is moved along the guide by rotation of the leadscrew, with movement of the carriage in opposite directions being achieved by rotation of the leadscrew in one of a clockwise or counter-clockwise sense.

11. The effector module of any of claims 8 to 10, wherein the first positioning unit includes a first drive element, which commonly -22 -couples the drive units of the first and second positioners, such that the first and second positioners are commonly driven.

12. The effector module of claim 11, wherein the first drive element comprises a belt.

13. The effector module of claim 11 or 12, wherein the first positioning unit includes a second drive element, which is coupled to the drive unit of one of the first and second positioners and the at least one actuator, such that operation of the at least one actuator causes the drive units of the first and second positioners to be driven simultaneously.

14. The effector module of claim 13, wherein the second drive element comprises a belt.

15. The effector module of any of claims 6 to 14, wherein the at least one actuator comprises one of a stepping motor or a servo motor, which allows for positioning of the carriages, and hence the end effector, in the one axis.

16. The effector module of any of claims 6 to 15, wherein the other, second positioning unit comprises a positioner, which is mounted to the bridge member of the first positioning unit In orthogonal relation to the guides of the first and second positioners thereof, and an actuator for actuating the positloner, such as to position the attachment member in the other, orthogonal axis.

17. The effector module of claim 16, wherein the positioner comprises a guide, which is mounted to the bridge member of the first positioning unit, a carriage which is slideably disposed on the guide, and a drive unit which is operable to move the carriage along a length of the guide.

-23 -

18. The effector module of claim 17, wherein the guide comprises a linear bearing.

19, The effector module of claim 17 or 18, wherein the carriage includes a screw-threaded element which extends parallel to the guide, and the drive unit comprises first and second bearing blocks which are disposed to opposite ends of the guide, and a leadscrew, which extends through the screw-threaded element of the carriage and is rotatably supported at opposite ends thereof by respective ones of the bearing blocks, such that the carriage is moved along the guide by rotation of the leadscrew, with movement of the carriage in opposite directions being achieved by rotation of the leadscrew in one of a clockwise or counter-clockwise sense.

20. The effector module of claim 19, wherein the second positioning unit includes a drive element, which is coupled to the leadscrew of the positioner and the actuator, such that operation of the actuator causes rotation of the lea dscrew.

21. The effector module of claim 20, wherein the drive element comprises a belt.

22. The effector module of any of claims 17 to 21, wherein the actuator comprises one of a stepping motor or a servo motor, which allows for positioning of the carriage, and hence the end effector, in the other axis.

23. The effector module of any of claims 1 to 22, further comprising: an end effector which is in use attached to the attachment member.

24. The effector module of claim 23, wherein the end effector is a fluid-dispensing effector for dispensing deposits, typically of a viscous -24 -material, such as an adhesive, a solder flux or a solder paste, from a reservoir onto a workpiece, in a desired pattern, with the fluid-dispensing effector being controlled to dispense fluid deposits in dependence of the movement thereof.

25. The effector module of claim 23, wherein the end effector is an ink-jetting effector for delivering a liquid to a workpiece in a desired pattern.

26. The effector module of claim 23, wherein the end effector Is a component-mounting effector for mounting components at defined locations on a workpiece.

27. The effector module of claim 23, wherein the end effector is a laser-etching effector for laser etching a desired pattern in a workpiece.

28. An effector module for use in a screen printing machine in place of a printing screen unit, the effector module comprising: a body which provides for mounting of the effector module in the screen printing machine; an attachment member to which an end effector is in use attached; and a positioning mechanism which is mounted to the body and connected to the attachment member, such as to provide for positioning of the attachment member relative to a workpiece which is in use supported by the screen printing machine.

29. The effector module of any of claims 1 to 28, further comprising: a control interface for interfacing the effector module to a controller, such as to achieve a desired operation of the effector module In accordance with control signals.

-25 -

30. The effector module of claim 29, wherein the control interface is mounted to the support member or the body.

31. The effector module of claim 29 or 30, where provided as a single, integral unit.

32. An effector system for use with a screen printing machine which includes a frame support for supporting a mounting frame of a printing screen unit, the effector system comprising: the effector module of any of claims 29 to 31.

33. The effector system of claim 32, further comprising: a dedicated controller, which is connected to the control interface for controlling operation of the effector module.

34. The effector system of claim 33, wherein the controller comprises a PC-based controller having a user interface.

35. The effector system of claim 33 or 34, wherein the control signals are provided in a programmed routine.

36. The effector system of any of claims 33 to 35, wherein the controller provides at least in part for automatic control of the effector module.

37. The effector system of claim 36, wherein the controller provides for automatic control of the effector module.

38. The effector system of any of claims 33 to 37, wherein the controller provides at least in part for manual control of the effector module.

39. The effector system of claim 38, wherein the controller provides for manual control of the effector module.

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40. The effector system of claim 32, wherein the control interface Is directly connected to the controller of the screen printing machine.

41. A method of operating a screen printing machine with the effector system of any of claims 32 to 40, the method comprising the steps of: loading the effector module into the frame support of the screen printing machine; locating a workpiece on a workpiece support adjacent the effector module; imaging fiducials on the workpiece and the effector module; aligning the effector module relative to the workpiece using the fiducials as imaged on the workpiece and the effector module; and operating the effector module in accordance with a control routine, such that the end effector performs a required operation on the

42. A method of operating a screen printing machine with an effector system, which comprises an effector module comprising a mounting frame for mounting the effector module in a frame support of the screen printing machine, an attachment member to which an end effector is attached and a positioning mechanism which is connected to the attachment member and operable to provide for positioning of the end effector relative to a workpiece as supported by the screen printing machine, the method comprising the steps of: loading the effector module into the frame support of the screen printing machine; locating a workpiece on a workpiece support adjacent the effector module; imaging fiducials on the workpiece and the effector module; aligning the effector module relative to the workpiece using the fiducials as imaged on the workpiece and the effector module; and -27 -operating the effector module in accordance with a control routine, such that the end effector performs a required operation on the

43. The method of claim 42, wherein the effector module loading step comprises the step of: loading the effector module into the frame unit of the screen printing machine in place of a printing screen unit.

44. The method of claim 42 or 43, further comprising the step of: fitting an end effector to the attachment member prior to loading the effector module into the frame support.

45. The method of claim 42 or 43, further comprising the step of: fitting an end effector to the attachment member subsequent to loading the effector module into the frame support.

46. The method of any of claims 42 to 45, wherein the workpiece locating step comprises the step of: locating a workpiece on a workpiece support beneath the effector module.

47. The method of any of claims 42 to 46, wherein the workplece locating step is performed automatically.

48. The method of any of claims 42 to 46, wherein the workplece locating step is performed manually.

49. The method of any of claims 42 to 48, wherein the imaging step is performed automatically.

50. The method of any of claims 42 to 48, wherein the imaging step is performed manually.

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51. The method of any of claims 42 to 50, wherein the imaging step comprises the step of: imaging fiducials on the workpiece and the end effector.

52. The method of any of claims 42 to 51, wherein the alignment step provides for alignment of the effector module relative to the workpiece, such as to establish common X and V axes and a datum for the end effector.

53. The method of any of claims 42 to 52, wherein the alignment step comprises the step of: moving the effector module in relation to the workpiece support, such as to align the effector module relative to the workpiece.

54. The method of any of claims 42 to 52, wherein the alignment step comprises the step of: moving the workpiece support in relation to the effector module, such as to align the effector module relative to the workpiece.

55. The method of any of claims 42 to 54, wherein the effector module operating step is performed automatically in response to a command signal from the controller of the screen printing machine.

56. The method of claim 55, wherein the command signal corresponds to a print command signal which normally operates the print head of the screen printing machine.

57. The method of any of claims 42 to 54, wherein the effector system further comprises a dedicated controller for controlling operation of the effector module, and the effector module operating step is performed automatically in response to a command signal from the dedicated controller.

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58. The method of claim 57, further comprising the step of: programming the dedicated controller with a control routine for controlling operation of the effector module.

59. The method of claim 58, wherein the programming is performed off-line, such as at a docking station.

60. The method of claim 58, wherein the programming is performed with the effector module in situ.

61. The method of any of claims 42 to 54, wherein the effector module operating step is actuated manually.

62. The method of any of claims 42 to 61, wherein the workpiece is a printed circuit board.

63. An effector module for use with a screen printing machine substantially as hereinbefore described with reference to Figures 2 to of the accompanying drawings.

64. A method of operating a screen printing machine with an effector system substantially as hereinbefore described with reference to Figures 2 to 5 of the accompanying drawings.