TW201704506A - Shadow mask alignment technique using variable pitch coding aperture - Google Patents

Abstract

In a shadow mask-substrate alignment method, a substrate and a shadow mask each include a grate having a plurality of bars in spaced relation, wherein for each grate, each pair of spaced bars of each grate is separated by a gap. The spacing between at least three adjacent gaps is different or not of constant pitch, and at least one grate includes a gap that extends therethrough. The grate of the substrate and the grate of the shadow mask are positioned in a light path. Thereafter, the orientation of the substrate, the shadow mask, or both are caused to be adjusted to position the grate of the substrate, the grate of the shadow mask, or both until a predetermined amount of light or range of an amount of light on the light path passing through one or both of the grates is received by a light receiver.

Description

Shadow mask alignment technique using variable pitch coding aperture Cross-references to related applications

This application is a continuation-in-part of U.S. Patent Application Serial No. 13/973,328, filed on Aug. Part of the continuation application, which is applied to the US National Phase of International Application No. PCT/US2011/037501 on May 23, 2011, which claims to apply for the US Provisional Application No. 61 on June 4, 2010. /351,470. The disclosures of the above documents are hereby incorporated by reference in its entirety.

Technical field to which the invention belongs

The present invention relates to accurate alignment of a shadow mask to a substrate associated with a deposition material of a vapor deposition system on a substrate.

The accurate alignment of the vapor deposition system with the shadow mask and substrate is critical for accurate deposition of one or more materials on the substrate. Unfortunately, most vapor deposition systems include closed vacuum deposition vessels in which one or more vapor deposition events occur and it is difficult to manually and accurately align the shadow mask to the substrate. In addition, the automatic and semi-automated systems currently used to align shadow masks to substrates do not have the necessary alignment accuracy to deposit materials in the vapor phase. The desired accuracy is provided on the board, particularly when the substrate is subjected to multiple vapor deposition events with a plurality of different shadow masks.

Accordingly, it would be desirable to provide an alignment method and system for aligning a shadow mask-substrate such that one or more materials can be vapor deposited onto the substrate in a highly accurate and repeatable manner via one or more shadow masks. .

Various preferred and non-limiting embodiments of the invention are described and illustrated in the following numbered items:

Clause 1: A shadow mask-substrate alignment method comprising the steps of: (a) providing a substrate comprising a grid having a plurality of bars in spaced relationship, wherein the substrate Each pair of spaced apart bars of the grid are separated by a gap, wherein the grid of the substrate comprises at least three gaps, wherein the spacing between each pair of adjacent gaps is different or not constant; (b) providing a shadow a mask comprising a grid having a plurality of bars in spaced relationship, wherein each pair of spaced bars of the grid of the shadow mask are separated by a gap through the shadow mask Wherein the grid of the shadow mask comprises at least three gaps, wherein the spacing between each pair of adjacent gaps is different or not constant; (c) providing an aligned direct source-light receiver, wherein the pair The light receiver is positioned in a path of the collimated light output by the aligned direct light source; (d) positioning the grid of the substrate and the grid of the shadow mask in the path of the collimated light And (e) after step (d), the orientation of the substrate, the shadow mask, or both is adjusted To locate the grating of the substrate, the shadow mask of the grid, or both, until a predetermined number of registration in the path of the collimated light that passes through the gap in the grating of the substrate and the shadow The gaps of the grid of the mask are received by the light receiver.

Clause 2: The method of clause 1, wherein: the grid of the substrate can comprise at least four gaps; and the grid of the shadow mask can comprise at least four gaps.

Clause 3: The method of clause 1 or 2, wherein: each gap may have the same width; and/or each bar may have a different width.

The method of any one of clauses 1 to 3, wherein the interval between each pair of adjacent gaps is variable according to one of the following items: Barker code, a line A linear chirp sequence, an exponential frequency sequence, a maximum length sequence, or a virtual random number sequence.

The method of any one of clauses 1 to 4, wherein the step (e) comprises: adjusting an orientation of the substrate, the shadow mask, or both to the substrate The long axes of the bars of the grid are positioned parallel to the long axis of the bars of the grid of the shadow mask, and the substrate and the bars of the grid of the shadow mask are Positioned so as to partially overlap the gaps of the shadow mask and the grids of the substrate.

The method of any one of clauses 1 to 5, wherein the substrate and the bars of the grid of the shadow mask are respectively associated with the shadow mask and the substrate The gaps of the grid have a 50% partial overlap.

The method of any one of clauses 1 to 6, wherein the collimating light source comprises an LED and a collimating lens operable to collimate light output by the LED; The light receiver can include a PIN diode and is operable to focus the light received thereby to the PIN diode A focusing lens on the top.

The method of any one of clauses 1-7, wherein: the substrate and the shadow mask each comprise a plurality of grids; the step (c) may comprise: providing a multi-aligned direct source - An optical receiver, wherein each of the pair of optical receivers is positioned in a path of collimated light output by the pair of collimated light sources; step (d) may comprise: a grid of the substrate and the shadow a grid of the mask is positioned in each path of the collimated light; and step (e) can include: adjusting an orientation of the substrate, the shadow mask, or both to position the grid of the substrate, The grid or both of the shadow masks until a predetermined amount of collimated light passes through the grids in the path on each path and is received by the light receiver in the path.

The method of any one of clauses 1-8, wherein: each of the optical receivers can output a signal having a level associated with the amount of light received by the optical receiver; and step (e) The method may include: adjusting the orientation of the substrate, the shadow mask, or both until the combination of signal levels output by the optical receivers is equal to a predetermined value or falls within a predetermined range of values.

The method of any one of clauses 1-9, wherein the predetermined value is zero.

The method of any one of clauses 1 to 10, wherein the substrate and the shadow mask each have a rectangular or square shape and a grid is adjacent to the rectangle or each corner of the square.

The method of any one of clauses 1-11, wherein the longitudinal axis of each bar extends radially from the central axis of the corresponding substrate or shadow mask by ±15 degrees.

Clause 13: A shadow mask-substrate alignment method comprising the steps of: (a) a collimating light source, a beam splitter, a substrate including a first grating, and a second grating a shadow mask, and a light receiver positioned relative to each other to define an optical path including collimated light output by the collimated light source and at least partially reflected by the beam splitter, at least partially reflected collimated Light passing through one of the first grid or the second grid and being at least partially reflected back through the first grid or the other of the first grid or the second grid The one of the second grids being reflected back through at least a portion of the reflected light of the one of the first grid or the second grid, at least partially passing through the beam splitter for Receiving, by the optical receiver; and (b) adjusting an orientation of the substrate, the shadow mask, or both to position the first grid, the second grid, or the first grid and the second grid Between the gates, until a predetermined number is received by the light receiver, wherein: each grid includes a plurality of spaced apart bars; each pair separates the bars into one Separating; each grid includes at least three gaps, wherein the spacing between each pair of adjacent gaps is different or not constant; and at least one of the first grid and the second grid includes an extension Passing at least one gap between the individual substrates and the shadow mask.

Clause 14: The method of clause 13, wherein: the grid of the substrate can comprise at least four gaps; and the grid of the shadow mask can comprise at least four gaps.

Clause 15: The method of clause 13 or 14, wherein: each gap may have the same width; and/or each bar may have a different width.

Clause 16: The method of any one of clauses 13-15, wherein The spacing between each pair of adjacent gaps may vary according to one of the following: a bar code, a chirp sequence, an exponential frequency sequence, a maximum length sequence, or a virtual random number sequence.

The method of any one of clauses 13-16, wherein: step (b) comprises: adjusting an orientation of the substrate, the shadow mask, or both to adjust the first grid The long axes of the bars of the grid are positioned parallel or substantially parallel to the long axis of the bars of the second grid, and the bars of the first grid and the second grid are positioned Each of the gaps of the second grid and the first grid partially overlaps.

The method of any one of clauses 13-17, wherein the first and second bars of the second and second grids are respectively associated with the second grid and the first grid These gaps have a 50% partial overlap.

The method of any one of clauses 13-18, wherein: the collimated light source comprises an LED and a collimating lens operable to collimate light output by the LED; The light receiver can include a PIN diode and a focusing lens operable to focus light received from the beam splitter onto the PIN diode.

Clause 20: The method of any of clauses 13-19, wherein a longitudinal axis of each bar extends radially at ±15 degrees from a central axis of the corresponding substrate or shadow mask.

2‧‧‧Shadow mask deposition system

4, 4a-4x‧‧‧ deposition vacuum container

6‧‧‧Substrate

8‧‧‧Distribution reel

10‧‧‧Retracting reel

12, 12a, 12b‧‧‧ deposition source

14, 14a, 14b‧‧‧ substrate holder

15, 15a, 15b, 15'‧‧‧ Shadow Mask Alignment System

16, 16a, 16b‧‧‧ shadow mask

20‧‧‧Mobile platform

20A‧‧‧Y-θ platform

20B‧‧‧X-Z platform

22‧‧‧ Controller

24, 24A-24D‧‧‧ light source

26, 26A-26D‧‧‧Optical Receiver

28, 28A-28D, 30, 30A-30D‧‧‧ grille

32, 34‧‧‧ central part

36, 36', 36A-36D, 36A’-36D’‧‧‧ light path

38‧‧‧LED

40‧‧‧ Collimating optics/lens

42, 46‧‧‧ (separated) poles

44, 48 ‧ ‧ gap; slit

50‧‧‧Focus optics/lens

52, 52A-52D‧‧‧ PIN diode

54‧‧‧ analog to digital (A/D) converter; A/D

60, 60A-60D‧‧ ‧ beam splitter

100, 100-1, 100-2, 100-3‧‧‧ graphics

102‧‧‧ first end

104‧‧‧ second end

106-1~106-17‧‧‧Gap-bar pair

P1~P17‧‧‧ pitch

1A is a schematic illustration of a shadow mask deposition system; FIG. 1B is an enlarged view of a single deposition vacuum container of the shadow mask deposition system of FIG. 1A; 2 is a schematic diagram of a first exemplary shadow mask alignment system; FIGS. 3A and 3B are each a plan view of an exemplary substrate and a shadow mask, each of which includes a plurality of alignment grids to facilitate orientation of the shadow mask to the substrate and Positioning, and vice versa; the isolated view of Figure 3C illustrates a single pattern consisting of variable pitch bars and gaps of a single aligned grid of the substrate and shadow mask illustrated in Figures 3A and 3B; A view taken along line IV-IV in FIG. 2; FIG. 5 is a view taken along line VV in FIG. 2; FIG. 6 is a schematic view of a second exemplary shadow mask alignment system; A view drawn by a line VI-VI in Fig. 6; and Fig. 8 is a view taken along a line VII-VII in Fig. 6.

Referring to FIGS. 1A and 1B, an exemplary shadow mask deposition system 2 for forming an electronic device, such as but not limited to a high resolution active matrix organic light emitting diode (OLED) display, includes a plurality of series arrangement The vacuum vessel 4 is deposited (for example, the vacuum vessels 4a to 4x are deposited). The arrangement and number of deposition vacuum vessels 4 depends on the number of necessary deposition events for any given product to be formed therefrom.

In an exemplary non-limiting use of the shadow mask deposition system 2, the continuously flexible substrate 6 is retracted to a reel by means of a dispensing reel 8 and a take-up reel 10. A reel-to-reel mechanism is used to translate through the deposition vacuum vessel 4 arranged in series. Alternatively, the substrate 6 can be translated through a series arrangement using any of the conventional components of the present technology. A separate (or continuous) substrate of the vacuum vessel 4 is deposited. Thereafter, in order to describe the present invention, the substrate 6 is assumed to be a single substrate.

Each deposition vacuum vessel includes a deposition source 12, a substrate holder 14, a shadow mask alignment system 15, and a shadow mask 16. For example, the deposition vacuum vessel 4a includes a deposition source 12a, a substrate holder 14a, a mask alignment system 15a, and a shadow mask 16a; the deposition vacuum vessel 4b includes a deposition source 12b, a substrate holder 14b, a mask alignment system 15b, and a shadow The mask 16b; and the like are used for any of a plurality of deposition vacuum vessels 4.

During a deposition event, each deposition source 12 is filled with the desired material to be deposited onto the substrate 6 through one or more openings of the corresponding shadow mask 16, corresponding to the shadow mask 16 in the corresponding deposition vacuum container. 4 is in close contact with one of the portions of the substrate 6. The shadow mask 16 can be a conventional single layer shadow mask or composite (multilayer) type shadow mask disclosed in U.S. Patent No. 7,638,417 to the name of the entire disclosure of which is incorporated herein by reference.

Each shadow mask 16 of the shadow mask deposition system 2 includes one or more openings. The opening in each of the shadow masks 16 corresponds to the material that will be deposited on the substrate 6 by the corresponding deposition source 12 in the corresponding deposition vacuum vessel 4 as the substrate 6 is translated through the shadow mask deposition system 2. Want graphics.

Each of the shadow masks 16 may be composed of, for example, nickel, chromium, steel, copper, Kovar® or Invar®, and has a thickness preferably between 20 and 200 microns, and at 20 to Better between 50 microns. For example, Kovar and Invar are available from ESPICorp, Inc., Aachen, Oregon, USA. In the United States, Kovar Alloy® is registered under No. 337,962 and is currently owned by CRS Holdings, Wilmington, Delaware. The registered trademark of Faw Alloy® is No. 63,970 and is currently owned by Imphy S.A of France.

Those skilled in the art will appreciate that the shadow mask deposition system 2 can include additional platforms (not shown) such as well known annealing platforms, test platforms, one or more cleaning platforms, cutting and mounting platforms, and the like. Moreover, for a particular application, one of ordinary skill in the art can modify the number, purpose, and configuration of the deposition vacuum vessels 4 as needed to deposit one or more materials in the desired order. An exemplary shadow mask deposition system and method of use thereof are disclosed in U.S. Patent No. 6,943,066, the disclosure of which is incorporated herein by reference.

The deposition vacuum vessel 4 can be used to deposit several materials on the substrate 6 to form one or more electronic components of the electronic device on the substrate 6. Each of the electronic components may be, for example, a thin film transistor (TFT), a memory element, a capacitor, or the like. A combination of one or more electronic components can be deposited to form higher level electronic components such as, but not limited to, sub-pixels or pixels of an electronic device. The multilayer circuit can be separately formed by continuously depositing material on the substrate 6 via the deposition vacuum vessel 4 in a continuous deposition event as described in U.S. Patent No. 6,943,066, the disclosure of which is incorporated herein by reference.

Each deposition vacuum vessel 4 is connected to a vacuum source (not shown) that is operable to establish a suitable vacuum therein to enable the material disposed in the corresponding deposition source 12 to be in a manner known in the art (eg, , sputtering or vapor deposition) is deposited on the substrate 6 through one or more openings corresponding to the shadow mask 16.

Regardless of the form of the substrate 6, for example, continuous sheet or separate The substrate, each deposition vacuum vessel 4, can include a bracket or guide that avoids sagging of the substrate 6 as it is translated through it.

During operation of the shadow mask deposition system 2, as the substrate 6 travels through the deposition of the vacuum vessel 4, the material disposed at each deposition source 12 is deposited by one or more openings of the corresponding shadow mask 16 under appropriate vacuum. Corresponding to the substrate 6 in the deposition vacuum vessel 4, a plurality of continuous patterns are formed on the substrate 6. More specifically, the substrate 6 is positioned in each deposition vacuum vessel 4 for a predetermined time interval. During this predetermined time interval, material is deposited on the substrate 6 by the corresponding deposition source 12. After this predetermined time interval, the substrate 6 is advanced to the next series of vacuum vessels for additional processing (if applicable). Moving on until the substrate 6 passes through all of the deposition vacuum vessel 4 and the substrate 6 leaves the last deposition vacuum vessel 4 in the sequence.

Referring to FIG. 2 and with continued reference to FIGS. 1A and 1B, the mask alignment system 15 includes one or more moving platforms 20 for controlling the orientation and position of the substrate 6, the shadow mask 16, or both for alignment as will be described later. Substrate 6 and shadow mask 16. A desirable non-limiting embodiment of the mask alignment system 15 includes a substrate 6 coupled to the Y-theta platform 20A and a shadow mask 16 coupled to the X-Z platform 20B. The substrate 6, the shadow mask 16 or both are in the X direction, the Y direction, the Z direction, and/or the θ direction using one or more platforms 20 (in the present embodiment, the θ direction is a rotation of the substrate 6 in the XY plane) The ability to translate, orient, and/or position is well known in the art and will not be further described herein for the sake of brevity.

Here, it is intended to treat words such as "translating", "translation", "orientation", "orientation", "positioning", and similar or similar foreign words as their generalized Described in the X direction, Y Movement of any or a combination of direction, Z direction, and/or θ direction. Therefore, such words should not be considered as limiting or limiting movement in either or more directions.

The Y-theta platform 20A and the XZ platform 20B are operated under the control of the controller 22, and the controller 22 can be implemented with any suitable and/or desirable combination of hardware and/or software to enable control of the mobile platform 20A in a manner that will be described later. And 20B.

The mask alignment system 15 further includes one or more light sources 24 and one or more light receivers 26. Each light source 24 is positioned to be aligned with a light receiver 26 to define a pair of light sources 24-to-light receiver 26. Each pair of light sources 24-optical receiver 26 defines an optical path 36 therebetween.

When the mask is used to align the system, the substrate 6 and the shadow mask 16 are positioned in the optical path 36 of each pair of light sources 24-photoreceiver 26. In a preferred embodiment, the mask alignment system 15 includes four light sources 24 and four light receivers 26, for a total of four pairs of light sources 24 - light receivers 26 defining four optical paths 36. However, this should not be construed as limiting the invention.

Referring to FIGS. 3A-3B and continuing to refer to FIGS. 1A-1B and 2, the substrate 6 includes one or more grids 28, and the shadow mask 16 includes one or more grids 30. In a non-limiting embodiment, the substrate 6 includes four grids 28A-28D and the shadow mask 16 includes four grids 30A-30D. In the embodiment illustrated in FIG. 3A, the substrate 6 has a rectangular or square shape and each of the grids 28A-28D is positioned adjacent one of the four corners of the substrate 6. Also, in the embodiment illustrated in FIG. 3B, the shadow mask 16 has a rectangular or square shape and each of the grids 30A-30D is positioned to be four with the shadow mask 16. One of the corners is adjacent. The central portion of the substrate 6 indicated by the symbol 32 is where deposition events will occur on the substrate 6. The central portion of the shadow mask 16 indicated by the symbol 34 is where the shadow mask 16 contains a pattern of one or more openings through which material from the deposition source 12 is deposited on the region 32. The same pattern as one or more of the openings 34 in the area 34 of the shadow mask 16.

Referring to FIG. 3C and continuing to FIG. 3A through FIG. 3B, in one embodiment, each of the grids 28 and 30 includes one or more patterns 100 comprised of variable pitch bars and gaps. In the embodiment illustrated in FIG. 3A, each of the grids 28 of the substrate 6 includes three patterns 100-1, 100-2, and 100-3 comprised of variable pitch bars and gaps. Similarly, in the embodiment illustrated in FIG. 3B, each of the grids 30 of the shadow mask 16 includes three patterns 100-1, 100-2, and 100-3 comprised of variable pitch bars and gaps. However, Figures 3A and 3B illustrate that each of the grids including three patterns 100 comprised of variable pitch bars and gaps should not be considered limiting of the present invention, as it is conceivable that each grid may include Any plurality of graphics 100 comprised of variable pitch bars and gaps, including one graphic, two graphics, or more than three graphics, as the skilled artisan would consider appropriate and/or desirable. Moreover, in the embodiment illustrated in Figures 3A and 3B, the grid 28 of the substrate 6 is identical to the grid 30 of the shadow mask 16. However, this should not be seen as limiting the invention, as it is conceivable that each grid 28 of the substrate 6 may comprise a number of figures that are the same or different from any one or more of the other grids 28 of the substrate 6. 100. Likewise, each of the grids 30 of the shadow mask 16 can include a number 100 that is the same or different than any one or more of the grids 30 of the shadow mask 16.

In one embodiment, each of the grids of the substrate 6 includes a plurality of spaced apart bars 42 which, in one embodiment, are spaced apart parallel bars. Each pair of spaced apart bars 42 are separated by a gap or slit 44 that passes through the substrate 6. In one embodiment, each gap 44 has the same width (or constant) while the width of each bar 42 is different. However, this should not be seen as limiting the invention, as it is conceivable that the width of each bar 42 may be the same and the width of each gap 48 may be different. In one embodiment, between the first end 102 and the second end 104 of each of the patterns 100 of each of the grids 28, the width of each of the bars 42 varies between the first end 102 and the second end 104. . Likewise, each grid 30 includes a plurality of spaced apart bars 46, in one embodiment, spaced apart parallel bars. Each pair of spaced apart bars 46 are separated by a gap or slit 48 that passes through the grid 30. In one embodiment, each gap 48 has the same width (or constant) and each bar 46 has a different width. However, this should not be considered as limiting the invention, as it is conceivable that the width of each gap 48 can be different and the width of each bar 46 can be the same. In one embodiment, between the first end 102 and the second end 104 of each of the patterns 100 of each of the grids 30, the width of each of the bars 46 varies between the first end 102 and the second end 104. .

In an embodiment, each gap 44 of the substrate 6 has the same width as each gap 48 of the shadow mask 16. However, this should not be considered as limiting the invention, as it is conceivable that the gap width of each of the grids 28, each grid 30, or grids 28 and 30 may vary.

The exemplary isolated view of FIG. 3C illustrates a single graphic 100 comprised of variable pitch bars and gaps of the grid 28 and/or grid 30. As can be seen from Figure 3C, the pitch between the same features of each gap-bar pair 106-1~106-17 P1-P17 or distance is variable. For example, the gap-bar pair 106-1 has a pitch P1 that is less than the pitch P2 of the gap-bar pair 106-2, then the pitch P2 is smaller than the pitch P3 of the gap-bar pair 106-3, and the like, Up to the pitch P17 of the gap-bar pair 106-17, in this embodiment, it is the largest pitch among the pitches P1 to P17. In the embodiment illustrated in Figure 3C, the width of each bar 42/46 is different.

The exemplary variable pitches P1 - P17 illustrated by the exemplary dimensions in Figure 3C should not be considered as limiting the invention, as it is conceivable that the variable pitch of the graphics 100 can be any suitable or desirable pitch pattern, For example, but not limited to: Barco code, chirp sequence, exponential frequency sequence, maximum length sequence, or virtual random number sequence. It is also conceivable to use a random variable pitch. For example, the pitch P3 may be smaller than the pitch P1, and the pitch P1 is smaller than the pitch P2.

By using the respective grids 28 and 30 of one or more of the patterns 100 composed of variable pitch bars and gaps, potential ambiguities due to the use of bars and gaps with constant pitch can be avoided.

The use of a mask alignment system 15 to align a substrate 6 having one or more grids 28 with a shadow mask 16 having one or more grids 30 will now be described.

Initially, as shown in FIG. 2, the substrate 6 is moved into a generally aligned manner with the shadow mask 16 in the optical path 36 between the light source(s) 24 and the light receiver (or plurality) 26. When the substrate 6 and the shadow mask 16 are substantially aligned in the optical path 36 shown in FIG. 2, each of the grids 28 of the substrate 6 and each of the grids 30 of the shadow mask 16 are positioned in a pair of light sources 24 - light receiving In an optical path 36 of the device 26. For example, the mask alignment system 15 includes four pairs of light source-light receivers 24A-26A, 24B-26B, 24C-26C, and 24D-26D each defining four optical paths 36A-36D, And the substrate 6 includes the grids 28A-28D, and the shadow mask 16 includes the grids 30A-30D: the grids 28A and 30A are positioned in the light path 36A from the light source 24A to the light receiver 26A; the grids 28B and 30B are positioned From the light source 24B to the optical path 36B of the light receiver 26B; the grids 28C and 30C are positioned in the optical path 36C from the light source 24C to the light receiver 26C; and the grids 28D and 30D are positioned from the light source 24D to the light receiver 26D. In the optical path 36D.

4 is a plan view of substrate 6 and shadow mask 16 that are generally aligned between light sources 24A-24D, light receivers 26A-26D (shown in phantom), and for each pair of light source-light receivers. The position of the light path 36A-36D. It should be understood that, in FIG. 4, the grids 28A and 30A are located in the optical path 36A; the grids 28B and 30B are located in the optical path 36B; the grids 28C and 30C are located in the optical path 36C; and the grids 28D and 30D are located. In the optical path 36D.

Once the substrate 6 is substantially aligned with the shadow mask 16, the coarse alignment of the substrate 6 with the shadow mask 16 can be selectively performed prior to the fine alignment of the substrate 6 with the shadow mask 16, as will be discussed below in conjunction with FIG. Describe the ground. For the following description, it is assumed that the coarse alignment of the substrate 6 with the shadow mask 16 is performed prior to fine alignment. However, this should not be seen as limiting the disclosure, as it is conceivable that the fine alignment can be performed directly after the above-described general alignment, thereby avoiding the substrate 6 and the shadow mask 16 which will be described next. Roughly aligned.

During coarse alignment, the shadow mask 16 is in spaced relation to the substrate 6 and each light source 24 is activated to output light along its optical path 36. A rough alignment of the substrate 6 and the shadow mask 16 in the X direction can be achieved by translating and orienting one or both of the substrate 6 and the shadow mask 16 in the ±X direction as needed. And/or positioning to maximize light passing through the grids 28 and 30 located in the optical path 36, thereby maximizing the light received by the corresponding light receiver 26. In an embodiment in which the substrate 6 and the shadow mask 16 are roughly aligned in the X direction, the shadow mask 16 in spaced relation to the substrate 6 is translated, oriented, and/or positioned in the ±X direction via the XZ platform 20B until The maximum amount of light originating from the light sources 24A-24D through the grids 28A-30A, 28B-30B, 28C-30C, and 28D-30D is each received by the light receivers 26A-26D. In this embodiment, the substrate 6 can remain stationary during the coarse alignment in the X direction. Each of the light source 24 and the light receiver 26 and means for processing the output of each of the light receivers 26 in response to receiving light from the corresponding light source 24 will be described in detail below with reference to FIG.

A rough alignment of the substrate 6 and the shadow mask 16 in the Y and θ directions can also be achieved by shifting, orienting, and/or one of the substrate 6 and the shadow mask 16 in the ±Y, ±θ directions as needed. Or positioned to maximize light passing through the grids 28 and 30 located in the optical path 36, thereby maximizing the light received by the corresponding light receiver 26. In an embodiment where the substrate 6 and the shadow mask 16 are roughly aligned in the Y direction, the substrate 6 in spaced relation to the shadow mask 16 is translated, oriented, and/or positioned in the ±Y direction via the Y-theta platform 20A. Until the maximum amount of light originating from the light sources 24A-24D through the grids 28A-30A, 28B-30B, 28C-30C, and 28D-30D is each received by the light receivers 26A-26D. Similarly, in an embodiment where the substrate 6 and the shadow mask 16 are roughly aligned in the θ direction, the substrate 6 in spaced relation to the shadow mask 16 is translated, oriented, and/or in the ±θ direction via the Y-theta platform 20A. Or positioned until the maximum amount of light from sources 28A-24D through grids 28A-30A, 28B-30B, 28C-30C, and 28D-30D is received by light receivers 26A-26D, respectively. In these embodiments, in the Y, θ directions During the coarse alignment, the substrate shadow mask 16 can remain stationary.

It is conceivable that the coarse alignment of the substrate 6 with the shadow mask 16 in the X, Y and θ directions can be done in any order. In addition, it is also conceivable that the substrate 6 and the shadow mask 16 can be successfully aligned in one or both of the X, Y and θ directions without having to use all three.

Referring to FIG. 5, a single pattern 100 of one of the grids 28 of the substrate 6 and a single pattern 100 of one of the grids 30 of the shadow mask 16 (ie, a pair of grids 28-30) are described along an optical path 36. Fine alignment. However, it should be understood that the fine alignment of the single pattern 100 of grid pairs 28-30 along the optical path 36 of FIG. 5 can also be applied to one or more of the pairs of grids 28-30 located in each of the optical paths 36. 100 alignment.

Beginning with the shadow mask 16 and the substrate 6 in spaced relationship and subsequent substantial or coarse alignment of the shadow mask 16 with the substrate 6, each light source 24 is activated to output light along its optical path 36 at the appropriate time. In a non-limiting embodiment, each light source includes an LED 38 that outputs light to a collimating optic/lens 40 that collimates light output by LED 38 and outputs the light along optical path 36. Collimate light.

With continued reference to FIG. 5 and with reference to FIGS. 3A and 3B, each bar or gap of the substrate 6 and shadow mask 16 need not be oriented or positioned at the same angle for the respective X-axis illustrated in FIG. 3A. In one embodiment, the longitudinal axes of the respective bars 42 of the substrate 6 and the respective gaps 44 are oriented or positioned at a nominal θ1 angle of 45 degrees as illustrated on the X-axis of FIG. 3A. However, the longitudinal axis azimuth angle θ1 of each of the bars 42 of the substrate 6 and each of the gaps 44 may have a nominal azimuth angle θ1 of 45 degrees ± 15 degrees with respect to the X-axis. In addition, it can be oriented or positioned at different angles θ1 Each bar 42 and each gap 44. However, it is preferable that the bars 42 and the gaps 44 of each of the grids 28 of the substrate 6 are parallel.

Also, in one embodiment, each of the bars 46 of the shadow mask 16 and the longitudinal axis of each gap 48 are preferably nominally oriented or positioned at an angle θ2 of 45 degrees for the X-axis illustrated in Figure 3B. . However, the azimuth angle θ2 of each bar 46 and the longitudinal axis of each gap 48 may have a nominal azimuth angle θ2 of 45 degrees ± 15 degrees with respect to the X axis. Moreover, each bar 46 can be oriented or positioned at a different angle θ2 from each gap 48. However, it is desirable that the bars 46 and gaps 48 of each of the grids 30 of the shadow mask 16 are parallel.

More generally, the longitudinal axes of each of the bars 42, 46 and the longitudinal axes of each of the gaps 44 and 48 may each extend ±15 degrees radially from the center of the substrate 6 and the shadow mask 16. In an embodiment, the bars and gaps of the grid may be parallel for each grid. However, it is also conceivable that the bars and gaps of the grid may extend radially from the center of the substrate 6 or the shadow mask 16 in a radial pattern, as the case may be. Thus, in an embodiment, but not limited to, the longitudinal axis of each bar 42, 46 and each gap 44, when the angles θ1-θ2 are oriented or positioned at an angle of 30 degrees for the corresponding X-axis, The longitudinal axis of 48 can be ±15 degrees from 30 degrees.

It will be appreciated that the angular displacement between the bars 42 and 46 of any pair of grids 28-30 and the gaps 48, 44 may differ by as much as 30 degrees, for example, when the bar 42 is 60 degrees to the X axis of the substrate 6. At the corners, the gap 48 has an angle of 30 degrees with respect to the X-axis of its shadow mask 16, and the substrate 6 is parallel to the X-axis of the shadow mask 16; 60 degrees and 30 degrees are 30 degrees apart.

Referring again to FIG. 5, the collimated light output by the light source 24 passes through each other. The gaps 44 and 48 of the grids 28 and 30 are generally or roughly aligned and received by the light receiver 26. The light receiver 26 includes a focusing optics/lens 50 that focuses the collimated light after passing through the roughly aligned gaps 44, 48 of the grids 28, 30 to be illuminated by the light detecting member in the form of a PIN diode 52. receive. The output of each PIN diode 52 of each of the light receivers 26 of the mask alignment system 15 is provided to the analog to digital (A/D) converter 54 of the controller 22 to classify each PIN diode 52. The output is converted to a corresponding digital signal for processing by the processing component of controller 22. The output of each PIN diode 52 corresponds to the amount of light received by the PIN diode 52. The greater the amount of light received by the PIN diode 52, the greater its output voltage, and the greater the amount of light received by the PIN diode 52. Small, its smaller the output voltage.

At the appropriate time, controller 22 begins to finely position substrate 6, shadow mask 16 or both via Y-theta platform 20A and/or XZ platform 20B to align substrate 6 with shadow mask 16 thereby positioning Each pair of grids 28-30 are in the optical path 36. The grids 28 have at least some of the bars 42 and some of the gaps 48 in the grid 30 (in the direction transverse to the optical path 36, preferably perpendicular). The overlap, and the grid 30, at least some of the bars 46 overlap with some of the gaps 44 in the grid 28 (in the direction transverse to the light path 36, preferably perpendicularly). In one embodiment, as shown in FIG. 5, preferably each gap 48 of the shadow mask 16 may partially overlap the bar 42 of the substrate 6, and the respective gaps 44 of the substrate 6 may be aligned with the bars of the shadow mask 16. 46 partially overlapped. In a more specific embodiment, the bars 42 and 46 can each overlap 50% of the width of the gaps 48, 44, respectively. In other words, the 50% width of the gaps 48, 44 can overlap the bars 42, 46.

For each pair of grids 28-30 located in one of the optical paths 36, the controller 22 takes the digitized output of the PIN diode 52 on the optical path 36 (this digital output is obtained via the A/D 54). And the digitized output corresponds to a collimated light passing through the gaps 48, 44) for comparison with a predetermined value or a predetermined range of values to detect when the bars 42, 46 each overlap the gaps 48, 44 to a desired extent.

Upon detecting that the digitized output of the PIN diode 52 is not within a predetermined or predetermined range of values, the controller 22 may cause one or more of the mobile platforms 20A and 20B to adjust the substrate 6, shadow mask 16, or both as needed. The X, Y, and/or θ positions until the controller 22 detects the amount of overlap between the bars 42 and 46 and the gaps 48 and 44 of the pair of grids 28-30 via the digitized output of the PIN diode 52. . Since the number of overlaps of the bars 42 and 46 and the pair of grid pairs 28-30 48 and 44 affects the amount of collimated light reaching the PIN diode 52, the digital output and predetermined by comparing the PIN diode 52 are compared. For a value or range of predetermined values, controller 22 can determine when the appropriate amount of overlap of the gap between bar and grid pair 28-30 at optical path 36 is achieved. In a similar manner, controller 22 can determine when the appropriate amount of overlap of the bar with each of the other pairs of grids 28-30 at each of the other optical paths 36 is achieved.

In one embodiment, controller 22 preferably combines the outputs of all of PIN diodes 52 in light receivers 26A-26D to determine when substrate 6 and shadow mask 16 achieve proper X, Y, and θ alignment. More specifically, assume that controller 22 adjusts the orientation/position of substrate 6, shadow mask 16, or both. After a certain period of time, the controller 22 stops adjusting the orientation/position of the substrate 6, the shadow mask 16, or both, and causes the A/D 54 sampling and digitizing the light receiver. The output of the PIN diodes 52A-52D (shown in Figure 4) of 26A-26D. The controller 22 associates the digitized output of the PIN diodes 52A-52D with the variables f1-f4 in the memory of the controller 22, and the X, Y and rotation or angle of the substrate 6, the shadow mask 16, or both ( The θ) displacement combines the variables in the following manner: ‧ (Equation 1) X displacement = f1 - f2 - f3 + f4; ‧ (Equation 2) Y displacement = f1 + f2 - f3 - f4; and ‧ (Equation 3) θ displacement = f1 - f2 + f3 - f4.

When the controller 22 determines that the X, Y, and θ displacements determined by Equations 1-3 above are each equal to 0, the controller 22 recognizes that this corresponds to the alignment of the substrate 6 and the shadow mask 16. On the other hand, if any of the above equations 1-3 is not equal to 0, the controller 22 recognizes that the situation corresponds to the substrate 6 and the shadow mask 16 having no alignment, so the controller 22 makes one or more. The multi-moving platform 20A-20B adjusts the X, Y, and/or θ positions of the substrate 6, the shadow mask 16, or both, and the X, Y, or θ displacements determined by Equations 1-3 above are each equal to zero as needed.

The controller 22 preferably repeats the steps of: adjusting the orientation/position of the substrate 6, the shadow mask 16, or both; stopping the orientation/position of the adjustment substrate 6, the shadow mask 16, or both; sampling and digitizing the PIN diode The outputs of the bodies 52A-52D; and determining whether the X, Y, and θ displacements determined by Equations 1-3 above are each equal to 0, until the X, Y, and θ displacements determined by Equations 1-3 above are each substantially equal to 0, These steps have occurred a predetermined number of repetitions, or a predetermined time has elapsed.

After determining that the X, Y, and θ displacements are each equal to 0, the controller 22 causes the moving platform 20 to move in the Z direction such that the substrate 6 and the shadow mask 16 are as shown in FIG. 5. The spaced relationship becomes intimate contact, the purpose of which is to align the substrate 6 with the shadow mask 16.

However, it should not be considered that using Equations 1-3 to determine that X, Y, and θ displacements are each equal to 0 in the manner described above is intended to limit the invention, as it is conceivable that each displacement may be unique to the displacement or for Equal displacements are within a common range of appropriate values. For example and without limitation, the controller 22 can be programmed to have an X displacement that is within a range of ±1 acceptable, a Y displacement that falls within a range of ±1.5, and fall within a range of ±0.5. The θ displacement is acceptable. Alternatively, controller 22 can be programmed to use the same range of values for each displacement. For example, controller 22 can be programmed such that it accepts that each of the X, Y, and θ displacements falls within the range of ±1.

It can be seen that with the output of the PIN diodes 52A-52D of the light receivers 26A-26D, the controller 22 can cause the substrate 6 and shadow mask 16 to be in a desired alignment with a high degree of accuracy. To this end, the controller 22 can progressively change the orientation/position of the substrate 6, shadow mask 16, or both until the grid 28 of the substrate 6 is aligned with the grid 30 of the shadow mask 16 to the desired extent. In the case where the controller 22 determines that the substrate 6 and the shadow mask 16 need further alignment, the controller 22 can make an informed decision as needed by the X, Y, and θ displacement values determined by Equations 1-3 above. 6. The shadow mask 16 or both are moved or rotated in that direction in the X, Y, and θ directions to improve alignment of the substrate 6 with the shadow mask 16. Therefore, the controller 22 can orient/position the substrate 6, the shadow mask 16 or both in the first position, and then take the output of the PIN diodes 52A-52D of the light receivers 26A-26D to determine the substrate 6 and the shadow mask. 16 is properly aligned. If so, the controller 22 causes the substrate 6 and the shadow mask 16 to be in the Z direction. Intimate contact is entered to prepare for the deposition event that occurs in the deposition vacuum vessel 4. However, if it is determined that the substrate 6 and the shadow mask 16 are not properly aligned, the controller 22 may progressively change the direction/position of the substrate 6, the shadow mask 16, or both to other locations, where the controller 22 samples the light reception. The outputs of the PIN diodes 52A-52D of the devices 26A-26D. The processing of the PIN diodes 52A-52D of the optical receivers 26A-26D and the process of progressively changing the direction/position of the substrate 6, the shadow mask 16, or both may continue to be sampled until the controller 22 uses the program of the controller 22. It is determined that the substrate 6 is aligned with the shadow mask 16 to a desired extent.

It can also be seen that controller 22 can adjust the orientation of substrate 6, shadow mask 16, or both to position grid 28 of substrate 6 and grid 30 of shadow mask 16, or both, until each light path 36 A predetermined amount of collimated light passes through the grid that falls on the optical path 36 for reception by the corresponding optical receiver 26. In other words, the controller 22 finely positions the substrate 6, the shadow mask 16, or both until a predetermined amount of light on each of the optical paths 36 passes through one or more of the patterns 100 in each of the optical paths and is The light receiver on the optical path is received.

Referring to Figure 6, all aspects of another exemplary shadow mask alignment system 15' are similar to the mask alignment system 15 illustrated in Figure 2, except that each pair of light sources 24-photoreceiver 26 is located The same side of the substrate 6 and the shadow mask 16; and each pair of light sources 24 - the light receiver 26 and the beam splitter 60 together define an optical path 36'. More specifically, each of the grids 28 of the substrate 6 and each of the grids 30 of the shadow mask 16 are located in an optical path 36' of the light source 24-photoreceptor 26 of Fig. 6. Each of the optical paths 36' extends from a light source 24 for reflection by one of the beam splitters 60, one of the beam splitters 60 being The grid 30 of the shadow mask 16 of the substrate 6 aligned with the grid 28 of the substrate 6 reflects the light from the source 24 to the grid 28 of the substrate 6. Some of the light striking the one or more bars 42 of the grid 28 of the substrate 6 is reflected back by the grid 28 through one or more of the grids 30 of the shadow mask 16 that are aligned with the grid 28. 40 faces the beam splitter 60. The beam splitter 60 causes some of the light rays reflected from the grid 28 of the substrate 6 after passing through the grid 30 aligned with the grid 28 in the shadow mask 16 to reach the light receiver 26 at the end of the light path 36'. .

The above description assumes that both the light source 24-optical receiver 26 pair and the beam splitter 60 are located on the opposite side of the shadow mask 16 from the substrate 6. However, it is conceivable that the light source 24-optical receiver 26 pair and beam splitter 60 may be located on the other side of the substrate 6, and then the light from the source 24 that is reflected by the beam splitter 60 is on the grid of the shadow mask 16. Before the partial reflection, the grating 28 passing through the substrate 6 is first passed, and the light that is partially reflected back through the grating 28 to the beam splitter 60 transmits some reflected light passing through the grating 30 to Light receiver 26. Thus, the light source 24-optical receiver 26 on the opposite side of the shadow mask 16 from the substrate 6 and the above-described Figure 6 of the beam splitter 60 are illustrated and illustrated in the above description and should not be considered as limiting the invention.

A shadow mask 16 of the substrate 6 with one or more grids 28 and one or more grids 30 aligned with the mask alignment system 15' will now be described.

Initially, the moving substrate 6 becomes roughly (or substantially) aligned with the shadow mask 16. When the substrate 6 is roughly aligned with the shadow mask 16, each of the grids 28 of the substrate 6 and each of the grids 30 of the shadow mask 16 are positioned in a pair of light sources 24 - the optical path 36' of the light receiver 26. For example, if the mask alignment system 15' includes four optical paths 36A', 36B', 36C', and 36D', respectively (also shown Figure 4) four pairs of light sources - light receivers 24A-26A, 24B-26B, 24C-26C and 24D-26D (schematically shown in Figure 7), and substrate 6 including grids 28A, 28B, 28C and 28D, and The shadow mask 16 includes grids 30A, 30B, 30C, and 30D: the grids 28A and 30A are positioned in the optical path 36A' extending from the light source 24A via the beam splitter 60A to the light receiver 26A; the grids 28B and 30B are located in the slave Light source 24B extends into beam path 36B' of light receiver 26B via beam splitter 60B; grids 26C and 30C are located in light path 36C' extending from light source 24C via beam splitter 60C to light receiver 26C; and grid 28D And the 30D bit is in the optical path 36D' that extends from the light source 24D via the beam splitter 60D to the light receiver 26D.

The top plan view of Figure 7 illustrates a substrate 6 roughly aligned with the shadow mask 16, wherein the light sources 24A to 24D, the light receivers 26A to 26D (illustrated in dashed lines), and the beam splitters 60A to 60D (in dotted form) are illustrated Shown, and optical paths 36A'-36D' for each pair of light source-light receivers. In FIG. 7, it should be understood that the grids 28A and 30A are located in the optical path 36A'; the grids 28B and 30B are located in the optical path 36B'; the grids 26C and 30C are located in the optical path 36C'; and the grids 28D and 30D Positioned in optical path 36D'; and each of grids 28 and 30 includes one or more patterns 100 of variable pitch bars and gaps as described with respect to Figures 3A-3C.

Referring to FIG. 8, a single pattern 100 of one of the grids 28 of the substrate 6 and a single pattern 100 of one of the grids 30 of the shadow mask 16 (ie, a pair of grids 28-30) are described along an optical path 36. 'The fine alignment. However, it should be understood that the fine alignment of the single pattern 100 of grid pairs 28-30 along the optical path 36' of Figure 8 can also be applied to one or more of each pair of grids 28-30 located in each of the optical paths 36'. Alignment of the graphic 100.

Starting with a shadow mask 16 in spaced relationship with the substrate 6, each light source 24 is activated to output light along its optical path 36' at the appropriate time. In a non-limiting embodiment, each light source includes an LED 38 that outputs light to a collimating optic/lens 40 that collimates light output by LED 38 and outputs the collimated light to At least the collimated light portion output by the collimating optics/lens 40 is reflected to the beam splitter 60 of a grid pair 28-30.

The collimated light from the beam splitter 60 through the gap 48 of one or more of the patterns 100 of the grid 30 and the gap 44 of one or more of the patterns of the grids 28 is reflected by the spaced bars 42 of the grid 28 The light didn't help. However, the collimated light reflected by the spaced bars 42 of one or more of the patterns of the grid 28 returns through the gap 48 of one or more of the patterns 100 of the grid 30 and propagates toward the beam splitter 60. At beam splitter 60, at least a portion of the reflected light passes through beam splitter 60 for reception by light receiver 26.

The focusing optics/lens 50 of the light receiver 26 concentrates the portion of the reflected light that passes through the beam splitter 60 toward the light detecting member in the form of a PIN diode 52. The output of each PIN diode 52 of each of the light receivers 26 of the mask alignment system 15' is provided to an analog to digital (A/D) converter 54 of the controller 22 (shown in Figure 6), which will The analog output of each PIN diode 52 is converted to a corresponding digital signal for processing by the processing component of controller 22. The output of each PIN diode 52 corresponds to the amount of light received by the PIN diode 52.

At the appropriate time, controller 22 initiates fine positioning of substrate 6, shadow mask 16 or both via Y-theta platform 20A and/or XZ platform 20B to align substrate 6 with shadow mask 16 such that Each light path 36', some of the bars 42 of the grille 28 overlap with some of the gaps 48 of the grille 30 (in the lateral direction, preferably perpendicular to the optical path 36'), whereas the bars 46 of the grille 30 have at least some Some of the gaps 44 of the grid 28 overlap to some extent (in the lateral direction, preferably perpendicular to the light path 36'). In an embodiment, the respective gaps 48 of the shadow mask 16 may partially overlap the bars 42 of the substrate 6, and the respective gaps 44 of the substrate 6 may partially overlap the bars 46 of the shadow mask 16, as shown in FIG. Shown. In a more specific embodiment, the bars 42 and 46 may each overlap a portion of the width of the gaps 48 and 44 by a desired percentage, such as 50%. In other words, the gaps 48 and 44 each have a width of 50% overlapping the bars 42 and 46.

For each of the pairs of grids 28-30 associated with one of the optical paths 36', the controller 22 detects when the bar 42 overlaps the gap 48 to a desired extent by comparing the PIN diode 52 to the optical path 36'. The digitized output is over a predetermined value or a predetermined range of values, wherein the digitized output is obtained via A/D 54 and the digitized output corresponds to light reflected from the bar 42 through the gap 48.

When detecting that the digitized output of the PIN diode 52 is not equal to a predetermined value or is not within a predetermined value range, the controller 22 causes the one or more moving platforms 20A and/or 20B to adjust the substrate 6, the shadow mask 16 or both as needed. The X, Y and/or θ position of the controller until the controller 22 detects the desired overlap of the bars 48 and 46 with the gaps 48 and 44 of the pair of grids 28-30 via the digitized output of the PIN diode 52. Since the amount of overlap of the bar 42 and the gap 48 of the grid pair 28-30 affects the amount of collimated light reaching the PIN diode 52, by comparing the digitized output of the PIN diode 52 with a predetermined value or a predetermined range of values, The controller 22 can determine when the bar 42 and the gap 48 of the grille pair 28-30 associated with the optical path 36' have been implemented. The appropriate number of overlaps. In a similar manner, controller 22 can determine when the bar 42 and the gaps 48 of the other pairs of grids 28-30 associated with the other respective optical paths 36' have achieved an appropriate amount of overlap.

In one embodiment, controller 22 preferably combines the outputs of all of PIN diodes 52 of optical receivers 26A through 26D to determine when substrate 6 and shadow mask 16 have achieved proper X, Y, and θ alignment. More specifically, it is assumed that the controller adjusts the orientation/position of the substrate 6, the shadow mask 16, or both. After a certain period of time, the controller stops adjusting the orientation/position of the substrate 6, the shadow mask 16 or both, and the PIN diodes 52A to 52D of the A/D 54 sampling and digitizing light receivers 26A to 26D ( The output shown in Figure 7). The controller 22 causes the digitized outputs of the PIN diodes 52A to 52D to be associated with the variables f1-f4 in the memory of the controller 22 and to combine the substrate 6, the shadow mask 16, or both X, Y, and rotation or angle (θ The variation of the displacement is as follows: ‧ (Equation 1) X displacement = f1 - f2 - f3 + f4; ‧ (Equation 2) Y displacement = f1 + f2 - f3 - f4; and ‧ (Equation 3) θ displacement = f1 F2+f3-f4.

Equations 1 through 3 above are copies of Equations 1 through 3 mentioned above when describing the first exemplary mask alignment system 15.

When the controller 22 determines that the X, Y, and θ displacements determined by the above Equations 1 through 3 are each equal to 0, the controller 22 considers this state to correspond to the substrate 6 and the shadow mask 16 to be aligned. On the other hand, if any of the above equations 1 to 3 is not equal to 0, the controller 22 considers this state to correspond to the substrate 6 and the shadow mask 16 that are not to be aligned, and then the controller 22 makes one or more The mobile platforms 20A-20B adjust the X, Y, and/or θ positions of the substrate 6, the shadow mask 16, or both as needed to cause the X bits determined by Equations 1 through 3 above. The shift, Y displacement, or θ shift are each equal to zero.

The controller 22 preferably repeats the steps of: adjusting the orientation/position of the substrate 6, the shadow mask 16, or both; stopping the orientation of the substrate 6, the shadow mask 16, or both; sampling and digitizing the PIN II The outputs of the polar bodies 52A to 52D; and determining whether the X displacement, the Y displacement, or the θ displacement determined by the above equations 1 to 3 are each equal to 0 until the X, Y, and θ displacements determined by the above equations 1 to 3 are actually equal to 0 Or until the steps have been repeated for a predetermined number of repetitions; or until a predetermined amount of time has elapsed.

When it is determined that the X, Y, and θ displacements are each equal to 0, the controller 22 moves the motion platform 20B in the Z direction to move the substrate 6 and the shadow mask 16 into a close contact from the position illustrated in FIG. 8 in a spaced relationship, The purpose of this separation is to align the substrate 6 with the shadow mask 16.

The X, Y, and θ displacements using Equations 1 through 3 to determine whether each is equal to 0 in the manner described above should not be considered as limiting the invention, as it is conceivable that the individual displacements may be unique to the displacement or for such The displacements are within a common range of appropriate values. For example and without limitation, the controller 22 can be programmed to have an X displacement that is within a range of ±1 acceptable, a Y displacement that falls within a range of ±1.5, and fall within a range of ±0.5. The θ displacement is acceptable. Alternatively, controller 22 can be programmed to use the same range of values for each displacement. For example, controller 22 can be programmed such that it accepts that each of the X, Y, and θ displacements falls within the range of ±1.

It can be seen that with the outputs of the PIN diodes 52A to 52D of the light receivers 26A to 26D, the controller 22 can cause the substrate 6 and the shadow mask 16 to be highly accurately aligned. To this end, the controller 22 can progressively change the orientation/position of the substrate 6, shadow mask 16, or both until the grid 28 of the substrate 6 is in a desired degree of alignment with the grid 30 of the shadow mask 16. In the controller 22 In the case where it is judged that the substrate 6 and the shadow mask 16 need further alignment, by the X, Y and θ displacement values determined by the above equations 1-3, the controller 22 can make an sensible decision as needed to make the substrate 6, the shadow The mask 16 or both are moved or rotated in that direction in the X, Y and θ directions to improve alignment of the substrate 6 with the shadow mask 16. Therefore, the controller 22 can orient/position the substrate 6, the shadow mask 16 or both in the first position, and then take the output of the PIN diodes 52A-52D of the light receivers 26A-26D to determine the substrate 6 and the shadow mask. 16 is properly aligned. If so, the controller 22 brings the substrate 6 into close contact with the shadow mask 16 in the Z direction to prepare for the deposition event that occurs in the deposition vacuum vessel 4. However, if it is determined that the substrate 6 and the shadow mask 16 are not properly aligned, the controller 22 may progressively change the direction/position of the substrate 6, the shadow mask 16, or both to other locations, where the controller 22 samples the light reception. The outputs of the PIN diodes 52A-52D of the devices 26A-26D. The processing of the PIN diodes 52A-52D of the optical receivers 26A-26D and the process of progressively changing the direction/position of the substrate 6, the shadow mask 16, or both may continue to be sampled until the controller 22 uses the program of the controller 22. It is determined that the substrate 6 is in a desired degree of alignment with the shadow mask 16.

Further, the controller 22 causes the orientation of the substrate 6, the shadow mask 16, or both to be adjusted to position the grid 28 of the substrate 6 and the grid 30 of the shadow mask 16 or both, up to each of the optical paths 36'. A predetermined amount of reflected light passes through the corresponding beam splitter 60 for reception by the corresponding light receiver 26. In other words, the controller finely positions the substrate 6, the shadow mask 16 or both until the light rays reflected by the bars 42 of the respective grids 28 have a predetermined number of passes through the gaps 48 of the respective grids 30 and the beam splitter 60 to be corresponding The optical receiver 26 receives.

As shown in Fig. 8, in the mask alignment system 15', the light sources 24A to 24D are each located on the same side of the shadow mask 16 as the light receivers 26A to 26D. Used as a beam combiner beam splitter 60 (illustrated as A 45 degree facet) optically combines each pair of light sources 24-optical receiver 26.

Each of the light receivers 26 is positioned such that its optical axis is perpendicular to the shadow mask 16 and the substrate 6 and is located on the opposite side of the shadow mask 16 from the substrate 6. However, this should not be construed as limiting the invention.

In the configuration illustrated in FIG. 8, light from the beam splitter 60 passes through the gap 48 of one or more of the graphics 100 of the shadow mask 16, and at least the bar 42 of the one or more graphics 100 of the substrate 6. Partial reflections, while the remaining light from the beam splitter 60 passes through the gap 44 of one or more of the patterns 100 of the substrate 6. Light reflected by the bar 42 of one or more of the graphics 100 of the substrate 6 passes through the gap 48 of one or more of the graphics 100 of the shadow mask 16 and then at least partially passes through the beam splitter 60 to be received by the optical receiver 26. receive.

Light source 24, including collimating optics/lens 40, is positioned transverse to the light receiver 26 comprising focusing optics/lens 50, preferably perpendicular. The beam splitter 60 is placed at the intersection of the optical axes of the light source 24 and the light receiver 26, and the plane of the beam splitter 60 is oriented to bisect the axis of the light source 24 and the light receiver 26 at right angles. In this manner, the collimated light from source 24 is reflected at 90 degrees, and then the reflected light propagates through the gap 48 of one or more of the patterns 100 of the shadow mask 16 grid 30 for the first time to strike the substrate 6 grid 28 The downwardly facing surface of the bar 42 and the bar 42 of at least one or more of the graphics 100 of the shadow mask 16 grid 30 are partially reflected toward the lower surface. The light reflected by the bar 42 of the grid 28 passes through the gap 48 of one or more of the patterns 100 of the shadow mask 16 for a second time, and then partially passes through the beam splitter 60 to be PIN diode of the light receiver 26. 52 received. Thus, the amount of light received by the PIN diode 52 of the light receiver 26 and the gap 48 of one or more of the patterns 100 of the grid 30 of the shadow mask 16 and one or more of the grids 28 of the substrate 6 are 100 The degree of overlap of the bars 42 is proportional. Therefore, the mask alignment 15' performs alignment sensing in the reflective mode. This is done in transmissive mode The above-described mask alignment system 15 of the quasi-sensing is compared.

Those skilled in the art should understand that some of the amount of light is lost because some of the light is used due to partial reflection and partial transmission of the beam splitter 60. It is not difficult to understand that the use of the collimating optics/lens 40 and the beam splitter 60 as a polarizing beam splitter can illustrate the inefficiency of the beam splitter 60.

In the above-described embodiment of the mask alignment system 15', each pair of light sources 24-optical receivers 26 and each corresponding beam splitter 60 are located on opposite sides of the shadow mask 16 from the substrate 6. However, this should not be seen as limiting the invention, as it is conceivable that one of the pair of light sources 24-optical receivers 26, or more or all and each of the respective beam splitters 60 may be located in the substrate 6. The side opposite the shadow mask 16, that is, on the other side of the substrate 6. In this particular embodiment, light from each beam splitter 60 will first pass through the gap 44 of the substrate 6 to be reflected by the bar 46 of the shadow mask 16, and then the reflected light will again pass through the gap 44 of the substrate 6 for subsequent It passes through beam splitter 60 to be received by light receiver 26.

The invention has been described in terms of several exemplary embodiments. Obviously, modifications and changes can be made after reading and understanding the above detailed description. It is intended that the present invention be construed as covering all such modifications and modifications as falling within the scope of the appended claims.

6‧‧‧Substrate

28A-28D‧‧‧ Grille

32‧‧‧Central Part

42‧‧‧ rods

44‧‧‧ gap; slit

100-1, 100-2, 100-3‧‧‧ graphics

102‧‧‧ first end

104‧‧‧ second end

Claims (20)

A shadow mask-substrate alignment method comprising the steps of: (a) providing a substrate comprising a grid having a plurality of bars in spaced relationship, wherein each pair of the grid of the substrate The spacer bars are separated by a gap, wherein the grid of the substrate includes at least three gaps, wherein an interval between each pair of adjacent gaps is different; (b) providing a shadow mask, the shadow mask including a grid of a plurality of bars in spaced relationship, wherein each pair of spaced apart bars of the shaded mask are separated by a gap through the shadow mask, wherein the shadow mask is The grid includes at least three gaps, wherein the spacing between each pair of adjacent gaps is different; (c) providing an aligned direct source-light receiver, wherein the pair of light receivers are positioned to be output by the aligned direct source (d) positioning the grid of the substrate and the grid of the shadow mask in the path of the collimated light; and (e) after step (d), Orienting the substrate, the shadow mask, or both to position the grid of the substrate, the shadow The grid or both of the cover until there is a predetermined amount of collimated light passing through the substrate in the path and the gaps in the grid of the shadow mask, and The optical receiver receives. The method of claim 1, wherein: the grid of the substrate comprises at least four gaps; and the grid of the shadow mask comprises at least four gaps. The method of claim 1, wherein: each gap has the same width; and/or each bar has a different width. The method of claim 1, wherein the interval between each pair of adjacent gaps varies according to one of the following items: a bar code, a chirp sequence, an exponential frequency sequence, a maximum length sequence, or A sequence of virtual random numbers. The method of claim 1, wherein: step (e) comprises: adjusting an orientation of the substrate, the shadow mask, or both to position a long axis of the bars of the grid of the substrate Parallel to the long axis of the bars of the grid of the shadow mask, and positioning the substrate and the bars of the grid of the shadow mask to each of the shadow mask and the substrate The gaps of the grids partially overlap. The method of claim 5, wherein the substrate and the bars of the grid of the shadow mask each have 50% of the gap between the shadow mask and the grid of the substrate Overlap. The method of claim 1, wherein: the collimated light source comprises an LED and a collimating lens operable to collimate light output by the LED; and the optical receiver comprises a PIN diode and A focusing lens is provided for focusing the light received thereby onto the PIN diode. The method of claim 1, wherein: the substrate and the shadow mask each comprise a plurality of grids; Step (c) includes: providing a multi-aligned direct light source-light receiver, wherein each of the pair of optical receivers is positioned in a path of collimated light output by the pair of collimated light sources; step (d) The method includes: positioning a grid of the substrate and a grid of the shadow mask in each path of collimated light; and step (e) includes: adjusting an orientation of the substrate, the shadow mask, or both Locating the grids of the substrate, the grids of the shadow mask or both until a predetermined amount of collimated light passes through the grids in the path on each path and is The optical receiver in the path is received. The method of claim 8, wherein: each of the optical receivers outputs a signal having a level associated with the amount of light received by the optical receiver; and step (e) includes: adjusting the substrate, the shadow mask Or the orientation of both until the combination of the signal levels output by the optical receivers is equal to a predetermined value or falls within a predetermined range of values. The method of claim 9, wherein the predetermined value is zero. The method of claim 8, wherein the substrate and the shadow mask each have a rectangular or square shape and a grid is adjacent to the rectangle or each corner of the square. The method of claim 1 wherein a longitudinal axis of each of the bars extends radially at ±15 degrees from a central axis of the corresponding substrate or shadow mask. A shadow mask-substrate alignment method comprising the steps of: (a) a collimating light source, a beam splitter, and a first grating a substrate, a shadow mask including a second grid, and a light receiver positioned relative to each other to define an optical path including collimated light output by the collimated light source and at least partially reflected by the beam splitter And at least partially reflected collimated light passes through one of the first grating or the second grating and is at least partially reflected by the other of the first grating or the second grating Passing back through the one of the first grid or the second grid, and being reflected back through at least a portion of the reflected light of the one of the first grid or the second grid, at least a portion Passing through the beam splitter for receipt by the light receiver; and (b) adjusting the orientation of the substrate, the shadow mask, or both to position the first grid, the second grid, or Both the first grid and the second grid are received by the light receiver until a predetermined number, wherein each grid comprises a plurality of spaced apart bars; each pair of spaced apart bars is separated by a gap Each grid includes at least three gaps, wherein an interval between each pair of adjacent gaps is different; and the first grid and the second grid It comprises at least one of the at least one gap extending through the substrate and the shadow mask individually. The method of claim 13, wherein: the grid of the substrate comprises at least four gaps; and the grid of the shadow mask comprises at least four gaps. The method of claim 13 wherein: each gap has the same width; and/or each bar has a different width. The method of claim 13, wherein the interval between each pair of adjacent gaps varies according to one of: a Barco code, a chirp sequence, an exponential frequency sequence, a maximum length sequence, or A sequence of virtual random numbers. The method of claim 13, wherein the step (b) comprises: adjusting an orientation of the substrate, the shadow mask, or both to position the long axis of the bars of the first grid to Parallel or substantially parallel to the long axis of the bars of the second grid, and positioning the first bar and the bars of the second grid to be respective to the second grid and the first These gaps of the grid partially overlap. The method of claim 17, wherein the bars of the first grid and the second grid each overlap 50% of the gaps of the second grid and the first grid . The method of claim 13, wherein: the collimated light source comprises an LED and a collimating lens operable to collimate light output by the LED; and the optical receiver comprises a PIN diode and A focusing lens for focusing light received from the beam splitter onto the PIN diode is operated. The method of claim 13 wherein a longitudinal axis of each bar extends radially by ±15 degrees from a central axis of the corresponding substrate or shadow mask.