Embodiments of the present invention provide for the continuous deposition of material onto a substrate in a pattern defined by a mask. The continuous deposition is provided by continuously moving a substrate and a mask through a deposition area provided by a deposition source and drum.
The substrate 100 begins on a roll of a substrate unwind reel 102 which serves as a delivery roller for the substrate 100 to the remainder of the apparatus of this first deposition stage. The substrate 100 is continuously pulled from the reel 102, through a dancer 104, over a tension load cell 106 by a precision drive roller 108. The substrate 100 is pulled tightly over a portion of a circumference of a rotating drum 124 and onto another receiving roller 110 for the substrate 100. The substrate 100 exits the receiving roller 110 and is either pulled into a subsequent deposition state, discussed below in relation to
The dancer 104 and tension load cell 106 are utilized to achieve a pre-determined and controlled elongation, or stretch, of the substrate 100 in the direction of delivery to the drum 124 for a given speed of the substrate 100. The speed of the substrate 100 is dictated by the speed of the precision drive roller 108, which is synchronized closely to the speed of the drum 124, which itself has a precision drive mechanism. The speed chosen is a matter of design choice, based on whether the pre-determined elongation and proper thickness of deposition can be achieved.
As is known in the art, the dancer 104 utilizes a rotary sensor to provide feed back to control the speed of the unwind reel 102, as a tensioning force is applied to the substrate 100 by an actuator of the dancer 104. The tension load cell 106 provides a force reading that can be used to trim the force applied by the actuator of the dancer 104. A control system applies logic based on the readings from the tension load cell 106 and the speed of the drum 124 to make a slight alteration of the speed of the drive roller 108 to control the elongation of the substrate 100 as desired.
The mask 101 begins on a roll of a mask unwind reel 112 which serves as a delivery roller for the mask 101 to the remainder of the apparatus of this first deposition stage. The mask 101 is continuously pulled from the reel 112, through a dancer 114, over a tension load cell 116 by a precision drive roller 118. The mask 101 is pulled tightly over the portion of a circumference of a rotating drum 124 where the substrate is also pulled to thereby bring the mask 101 into contact with the substrate 100 and is further pulled onto a receiving roller 120 for the mask 101. The mask 101 exits the receiving roller 120 and is rewound onto a substrate rewind reel 122.
As with the substrate 100, the dancer 114 and tension load cell 116 are utilized to achieve a pre-determined and controlled elongation, or stretch, of the mask 101 in the direction of delivery to the drum 124 for a given speed of the mask 101. The speed of the mask 101 is further dictated by the speed of the precision drive roller 118, which is also synchronized closely to the speed of the drum 124. As discussed above in relation to the substrate 100, the speed chosen is a matter of design choice, based on whether the pre-determined elongation and proper thickness of deposition can be achieved.
As with the dancer 104, the dancer 114 utilizes a rotary sensor to provide feed back to the mask unwind reel 112 as a tensioning force is applied to the mask 101 by an actuator of the dancer 114. The tension load cell 116 provides a force reading that can be used to trim the force applied by the actuator of the dancer 114. A control system applies logic based on the readings from the tension load cell 116 and speed of the drum 124 to make a slight alteration of the speed of the drive roller 118 to control the elongation of the mask 101 as desired.
This particular embodiment includes a deposition source 126 that is located internally within the drum 124. Therefore, it is necessary to have the mask 101 be in direct contact with the drum 124 while the substrate 100 is in direct contact with the mask 101 and separated from the drum 124 by the mask 101. The drum 124 has large apertures 130 designed into the roll to accommodate material flux towards the mask with little restriction and that are spaced around its circumference to allow deposition material 128 emitted from the deposition source 126 to pass through the drum 124 and reach the mask 101. The apertures in the mask then allow the deposition material 128 to reach the substrate 100 to thereby form the pattern on the substrate 100.
The deposition source 126 may be one of various types depending upon the type of deposition and type of deposition material desired. For example, the deposition source 126 may be a sputtering cathode or magnetron sputtering cathode for purposes of depositing metallic or conductive metal oxide materials. As another example, the deposition source 126 may be an evaporation source for purposes of depositing metallic or conductive metal oxide materials.
The configuration of the drum 124, deposition source 126, mask 101, and substrate 100 may be such that the mask 101 and substrate 100 pass on the bottom of the drum with the deposition source 126 emitting the deposition material downward. However, it will be appreciated that the mask 101 and substrate 100 may alternatively be positioned so as to pass over the top of the drum 124 while the deposition source 126 emits the deposition material upward. This alternative is particularly the case where an evaporation source is used.
The substrate 100 and the mask 101 may also be one of various types of materials. Examples include polymeric materials, such as polyester (both PET and PEN), polyimide, polycarbonate, or polystyrene, metal foil materials, such as, stainless steel, other steels, aluminum, copper, or paper or woven or nonwoven fabric materials, all of the above with or without coated surfaces. However, utilizing a material with high elasticity, such as a polymeric material, for the substrate and mask allows for precision control of the elongation and for precision registration, as discussed below in relation to
However, the mask 201 is a continuous loop that passes from a tension load cell 234 which is a roller of a web guide 232 and is pulled by drive roller 218 as it passes by a sensor 238. The mask 201 passes over the portion of the circumference of the drum 224 and is pulled away over receiving roller 220. The mask 201 then reaches another receiving roller 222 that is a roller of a tensioner 223 and routes the mask 201 to subsequent receiving roller(s) 230 that then route the mask 201 back to a roller 236 of the web guide 232. In this configuration, the elongation and speed of the mask 201 continues to be controlled by adjusting the force applied by an actuator of the tensioner 223 and the speed of the drive roller 218 based on readings from the tension load cell 234, and the lateral alignment of the mask 201 is also controlled by the web guide 232, where such a web guide is discussed in more detail below in relation to
While
However, the deposition source 326 is located externally of the drum 324 such that the deposition material 328 does not need to pass through the drum 324 prior to reaching the mask 301 and substrate 300. Therefore, the drum 324 need not necessarily include apertures. Additionally, the substrate 300 is in direct contact with the drum 324 while the mask 301 is in direct contact with the substrate 300 with the substrate 300 being positioned between the mask 301 and the drum 324.
While
The pattern elements may be pre-formed onto the substrate in one of many various ways which also apply to depositing such pattern elements onto the mask as described in any of these examples of
In the embodiment of
However, there is additional control of the elongation and speed based on sensing the fiducials of both the substrate 400 and the mask 401 to maintain the substrate 400 and mask 401 in proper registration to within a tolerance of ½ of the smallest feature dimension (less than 100 microns; less than 50 microns; or even less than 25 microns) in the direction of delivery to the drum 424. Sensor 438 senses the fiducials on the substrate 400 while sensor 448 senses the fiducials on the mask 401. The relative speed between the substrate 400 and mask 401 may be adjusted via the drive rollers 408 and 418 respectively to compensate for the substrate 400 either leading or lagging the mask 401.
Furthermore, between the load cell 406 and the drive roller 408 for the substrate 400, a precision web guide 430 receives the substrate 400 and controls the transverse position of the substrate based on the sensor 438, sensing the fiducials to determine the transverse position. Moving webs have a tendency to move transversely on the rollers, but in most instances, the transverse position must be maintained within a precise tolerance of at least ½ of the smallest feature dimension (less than 100 microns; less than 50 microns; or even less than 25 microns) at the drum 424, so the web guide 430 adjusts the transverse position of the substrate 400. The web guide 430 includes a first roller 432, a frame 434, and a second roller 436. The frame 434 may be pivoted into and out of the page as shown at a pivot point at the edge of first roller 432 in order to guide the substrate 400 and change its transverse position on driver roller 408, and hence on drum 424. More details about a precision web guide suitable for this purpose can be found in U.S. Patent Application Publication No. 2005/0109811 (Swanson et al.), incorporated herein by reference.
Similarly for the mask 401, between the load cell 416 and the drive roller 418, a precision web guide 440 receives the mask 401 and controls the transverse position of the mask 401 based on the sensor 448 sensing the fiducials to determine the transverse position. The transverse position of the mask 401 must also be within a precise tolerance at the drum 424, so the web guide 440 adjusts the transverse position of the mask 401. The web guide 440 includes a first roller 442, a frame 444, and a second roller 446. The frame 444 may be pivoted into and out of the page as shown at a pivot point at the edge of first roller 442 in order to guide the mask 401 and change its transverse position on driver roller 418, and hence on drum 424.
A transverse position control system can be used in conjunction with or can be used independently of an elongation control system. Similarly, an elongation control system can be used in conjunction with or can be used independently of a transverse position control system.
As in
In the embodiment of
However, there is additional control of the elongation and speed based on sensing the fiducials of the mask 501 using sensor 538 to maintain the mask 501 in proper registration in the direction of delivery to the drum 524 with the fiducial patterning process 540. The relative speed of the mask 501 may be adjusted via the drive roller 518 to compensate for the mask 501 either leading or lagging the fiducial patterning process 540.
Furthermore, between the load cell 516 and the drive roller 518, a precision web guide 530 controls within a precise tolerance the transverse position of the mask 501 based on the sensor 538 sensing fiducials on the mask 501 to determine the transverse position. The web guide 530 includes a first roller 532, a frame 534, and a second roller 536. The frame 534 may be pivoted into and out of the page as shown at a pivot point at the edge of first roller 532 in order to guide the mask 501 and change its transverse position on driver roller 518, and hence on drum 524.
As in
In the embodiment of
There is additional control of the elongation and speed based on sensing the fiducials of both the substrate 600 and the mask 601 to maintain the substrate 600 and mask 601 in proper registration in the direction of delivery to the drum 624. Sensor 638 senses the fiducials on the substrate 600 while sensor 648 senses the fiducials on the mask 601. The relative speed between the substrate 600 and mask 601 may be adjusted via the drive rollers 608 and 618 respectively to compensate for the substrate 600 either leading or lagging the mask 601.
Furthermore, between the load cell 602 and the drive roller 608 for the substrate 600, a precision web guide 630 receives the substrate 600 and controls the transverse position of the substrate based on the sensor 638 sensing the fiducials to determine the transverse position. The web guide 630 includes a first roller 632, a frame 634, and a second roller 636. The frame 634 may be pivoted into and out of the page as shown at a pivot point at the edge of first roller 632 in order to guide the substrate 600 and change its transverse position on driver roller 608, and hence on drum 624.
Similarly for the mask 601, between the load cell 616 and the drive roller 618, a precision web guide 640 receives the mask 601 and controls the transverse position of the mask 601 based on the sensor 648 sensing the fiducials to determine the transverse position. The web guide 640 includes a first roller 642, a frame 644, and a second roller 646. The frame 644 may be pivoted into and out of the page as shown at a pivot point at the edge of first roller 642 in order to guide the mask 601 and change its transverse position on driver roller 618, and hence on drum 624.
As in
The position command 701 is also summed with another signal that is based on a load position feed back signal 703 being provided to a low pass filter operation 704. The load position feed back signal 703 is received on the basis of a high precision rotary sensor mounted directly on a drive roller or drum. The low pass filter operation 704 provides an output to observers 706 that use other internal signals to generate an output that is applied to a feedback filtering operation 708 to provide the signal that is negatively summed with the position command 701. This signal is then fed to a position controller 710 which outputs a signal that is summed with two additional signals.
The feed forward gain signal output by the feed forward gain control operation 712 is summed with the output signal of the position controller 710 along with a motor position feed forward feedback signal that is output by position feed forward derivative operation 714 and is passed through a low pass filter 715 and that is based upon a received motor position feedback signal 705. This signal 705 is received from a high precision rotary sensor mounted on the armature of the motor that is driving a drive roller or drum. The output of the summation is then provided to a low pass filter 720 whose output is then provided to a velocity controller 722.
The feed forward gain signal output by the feed forward gain operation 712 is then provided to a velocity feed forward operation 716 which provides an output to a feed forward gain operation 718 to produce a second feed forward gain signal. The second feed forward gain signal is provided to a current feed forward operation 724 that supplies an output to a feed forward gain operation 726. Additionally, the second feed forward gain signal is summed with the output of the velocity controller 722 and from a web commanded velocity feed forward signal 707 which comes from the trajectory generator. The trajectory generator generates a position reference for each roller's control system, including position and velocity in proper units. The result of summing the velocity feed forward signal 707 with the output of velocity controller 722 is passed through notch and other filters 728 and is summed with the feed forward gain signal as output by the feed forward gain operation 726 and with the actual motor current measurement 709 to provide an input to a current controller 730. The current controller 730 then outputs a current to the motor that is driving a drive roller or drum.
The position command 801 is also summed with another signal that is based on a load position feed back signal 803 being provided to a low pass filter operation 804. The load position feed back signal 803 is received on the basis of a high precision linear sensor mounted directly on the web guide frame. The feed forward operation 804 provides an output to observers 806 that use other internal signals to generate an output that is applied to a feedback filtering operation 808 to provide the signal that is negatively summed with the position command 801. This signal is then fed to a position controller 812 which outputs a signal that is summed with two additional signals discussed below.
The feed forward gain signal output by feed forward gain control operation 810 is summed with the position controller output signal 812 along with a motor position feed forward feedback signal that is output by position feed forward derivative operation 809 and passed through a low pass filter 811 and that is based upon a received motor position feedback signal 805. This signal 805 is received on the basis of a high precision rotary sensor mounted directly on the armature of the motor that is moving the web guide frame. The output of the summation is then provided to a low pass filter 818 whose output is then provided to a velocity controller 820.
The feed forward gain signal output by the feed forward gain control operation 810 is then provided to a velocity feed forward operation 814 which provides an output to a feed forward gain operation 816 to produce a second feed forward gain signal. The second feed forward gain signal is provided to a current feed forward operation 822 that supplies an output to a feed forward gain operation 824. Additionally, the second feed forward gain signal is summed with the output of the velocity controller 820. The result is passed through notch and other filters 826 and is summed with the output of the feed forward gain operation 824 and the actual motor current measurement 807 to provide an input to a current controller 828. The current controller 828 then outputs a current to the motor that is moving the web guide frame.
The position command 901 is also summed with another signal that is based on a web position feed back signal 903. The web position feed back signal 903 is received on the basis of the longitudinal web position. This signal can represent the substrate or mask position, or the difference between them. The web position feedback signal 903 is provided to observers 904 that enhance the position signal generated by the sensor and whose output is applied to a feedback filtering operation 905 to provide the signal summed with the position command 901. The signal resulting from this summation is then fed to a position controller 910 which outputs a signal that is summed with two additional signals as will be described in the following paragraph.
The feed forward gain signal output by the feed forward gain control operation 908 is summed with the signal output by the position controller 910 along with a web feed forward open loop position compensation signal 912 that comes from the trajectory generator. The output of the summation is a guide position command that is then provided to the web position controller shown in
The mask 1001 enters a web guide 1030 having rollers 1032 and 1036 mounted to a frame 1034. The mask 1001 passes a sensor 1038 that detects the longitudinal and/or lateral web position, and the drive roller 1008 makes final corrections to the elongation and velocity of the mask 1001 as it travels onto the portion of the circumference of the drum 1024 while the exit roller 1010 directs the mask 1001 away from the drum 1024.
During operation, the substrate sensor 1048 and the mask sensor 1038 output web position feedback signals to a strain controller 1052. The strain controller then generates an output signal to a virtual tension observer 1054. A virtual tension observer is a control system technique wherein the value of one variable is estimated based upon known values of other variables. Observers improve control system performance by reducing a variable's measurement lag, increasing its accuracy, or providing the value of a variable that is difficult or impossible to measure directly. The virtual tension observer 1054 then calculates the tension of the webs based on the position feedback provided to the strain controller 1052 and the material parameters for the substrate and the mask, and generates the proper tension setpoints to upstream controllers, as wells as additional corrective position command offsets that may be added to either drive roller. The virtual tension observer is able to estimate changing parameters in real time. Additional details of the virtual tension observer of this embodiment can be found in commonly owned U.S. Patent Application Publication 2005/0137,738 A1. The virtual tension observer 1054 then provides a drive signal to the motor of the driver roller 1008.
As shown in this example, the lateral or crossweb fiducial may be a line 1202 that is a fixed distance from deposition patterns to be located on the substrate or mask 1200. An edge 1201 of the web 1200 may not be located in a precise relationship to the crossweb fiducial line 1202 or any deposition patterns on the web 1200. From sensing the location of the line 1202 in the lateral direction, it can be determined whether the web 1200 is in the proper location or whether a web guide adjustment is necessary to realign the web in the lateral direction.
As is also shown in this example, the longitudinal or machine direction fiducial may be a series of marks 1204 spaced a fixed distance from one another in the machine direction. From sensing the position of a mark 1204 in the series, it can be determined whether the web 1200 is at the proper longitudinal position relative to deposition patterns on the web 1200 at a given point in time.
The sensor 1312 output is directed to a real time image data acquisition process 1314. In addition to receiving the sensor output, the real time image data acquisition process 1314 of this embodiment also receives a position reference 1311 from the longitudinal control system for the web being sensed that synchronizes the capture of the position of the fiducial mark image. The real time image data acquisition process directs the output of a digital image to a digital image processing system 1316. The digital image processing system 1316 analyzes the image to determine how far the lateral and longitudinal marks are from their expected locations. The position error 1318 for the longitudinal or machine direction is output to the longitudinal direction control system for the web being sensed while the position error 1320 for the lateral or crossweb direction is output to the web guide control system.
The output from the sensor 1412 is provided to the photodetector circuit 1416 where the fiducial may be observed and where it may be determined how far the actual location of the longitudinal fiducial marking is from the expected location. The position error 1418 for the longitudinal or machine direction is output to the longitudinal direction control system for the web being sensed.
The output from the sensor 1414 is provided to the image processing 1420 of the camera where it may be determined how far the actual location of the lateral fiducial marking is from the expected location. The position error 1422 for the lateral or crossweb direction is output to the web guide control system.
In another aspect, a method of continuously depositing material is provided using the apparatus described above. The method involves continuously delivering a substrate from a substrate delivery roller while continuously receiving the substrate onto a first substrate receiving roller, wherein the substrate passes over a portion of a circumference of a first drum when between the substrate delivery roller and the first substrate receiving roller. The method further involves while continuously delivering and receiving the substrate, continuously delivering a first mask from a first mask delivery roller while continuously receiving the first mask onto a first mask receiving roller, wherein the first mask passes over a portion of a circumference of the first drum when between the first mask delivery roller and the first mask receiving roller and wherein the first mask has a plurality of apertures forming a first pattern and at least a portion of the apertures have a least dimension of 100 microns or less. Additionally, the method involves while continuously delivering and receiving the substrate and the first mask, continuously directing a first deposition material from a first deposition source toward a portion of the first mask that is over the portion of the circumference of the first drum such that the first pattern of first material is deposited on the substrate.
The method can further involve continuously delivering the substrate from the first substrate receiving roller while continuously receiving the substrate onto a second substrate receiving roller, wherein the substrate passes over a portion of a circumference of a second drum when between the first substrate receiving roller and the second substrate receiving roller. The method still further involves continuously delivering a second mask from a second mask delivery roller while continuously receiving the second mask onto a second mask receiving roller, wherein the second mask passes over a portion of a circumference of the second drum when between the second mask delivery roller and the second mask receiving roller and wherein the second mask has a plurality of apertures forming a second pattern. Additionally, the method involves while continuously delivering and receiving the substrate and the second mask, continuously directing a second deposition material from a second deposition source toward a portion of the second mask that is over the portion of the circumference of the second drum such that the second pattern of second deposition material is deposited on the substrate.
While the invention has been particularly shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made therein without departing from the spirit and scope of the invention.
This application claims priority to U.S. patent application Ser. No. 11/179,418 filed on Jul. 12, 2005 and incorporated herein in its entirety.