Drawing apparatus

Abstract

An autofocus mechanism (5) of the drawing apparatus includes a sensor unit (51), a lens movement mechanism (52), and an auxiliary support unit (53). The sensor unit (51) measures the distance between the second lens group (452) and the substrate (9) in the vertical direction. The lens moving mechanism (52) supports the second lens group (452). The lens movement mechanism (52) moves the second lens group (452) in the vertical direction on the basis of the output from the sensor unit (51), thereby adjusting the focus position of the light emitted from the drawing head (41). The auxiliary support section (53) continuously applies an upward force to the second lens group (452), and the auxiliary lens movement mechanism (52) supports the second lens group (452). As a result, it is possible to suppress micro-vibration when the second lens group (452) rises and falls.

Description

Technical Field

[0001] The present invention relates to a drawing device for drawing a pattern by irradiating light onto a substrate.

[0002] [Reference to related applications]

[0003] This application claims priority to Japanese patent application JP2023-133223 filed in Japan on August 18, 2023, and incorporates the entire disclosure of that application into this application. Background Art

[0004] In the past, there is a known direct drawing device that draws a pattern by irradiating a printed wiring board (hereinafter, also referred to as a "substrate") on a stage with modulated light and scanning the irradiated area of ​​the light on the substrate. In such a direct drawing device, an automatic focusing mechanism is provided to cope with the unevenness of the substrate surface.

[0005] For example, the autofocus mechanism provided in the drawing device of Japanese Patent Gazette No. 2016-31502 (Document 1) includes: a detector for detecting changes in the distance between the optical head and the surface of the substrate; a lifting mechanism for holding the lens of the projection optical system and lifting it; and a control unit for calculating the lifting amount of the lens based on the change amount detected by the detector.

[0006] However, in the drawing device such as that in Document 1, when the autofocus mechanism is working, the lens etc. may generate micro-vibration due to the driving load applied to the lifting mechanism etc. In the future, if the pattern is required to be more precise, the variation of the line width of the pattern caused by the micro-vibration of the lens etc. may not converge to the desired accuracy. Summary of the invention

[0007] An object of the present invention is to suppress micro vibrations when an autofocus mechanism moves a lens group.

[0008] A drawing device according to a first aspect of the present invention, which draws a pattern by irradiating light onto a substrate, wherein the device comprises: a stage for holding a substrate; a drawing head for irradiating modulated light onto the substrate; and a stage moving mechanism for moving the stage relative to the drawing head in a direction parallel to the upper surface of the substrate. The drawing head comprises: an illumination optical system for receiving light emitted from a light source; a light modulating unit for modulating the light guided by the illumination optical system; a projection optical system for guiding the light modulated by the light modulating unit toward a substrate; and an automatic focusing mechanism for adjusting the focus position of the light emitted from the drawing head according to a change in the distance between the projection optical system and the substrate. The projection optical system comprises: a first lens group for receiving light modulated by the light modulating unit; and a second lens group for guiding the light guided by the first lens group toward the substrate. The autofocus mechanism comprises: a sensor portion for measuring the distance between the second lens group and the substrate in the up-down direction; a lens moving mechanism for supporting the second lens group and moving the second lens group in the up-down direction based on the output from the sensor portion, thereby adjusting the focusing position of the light emitted from the drawing head; and an auxiliary support portion for continuously applying an upward force to the second lens group, thereby assisting the lens moving mechanism in supporting the second lens group.

[0009] According to the present invention, it is possible to suppress micro vibrations that occur when the autofocus mechanism moves the lens group.

[0010] According to a second aspect of the present invention, in the drawing device described in the first aspect, the drawing head further includes a frame supporting the lens moving mechanism. The auxiliary support portion includes an elastic member that connects the frame and the second lens group in an elastically deformed state.

[0011] According to a third aspect of the present invention, in the image drawing device according to the second aspect, the elastic member is a coil spring extending in the vertical direction, and the coil spring connects the frame and the second lens group in a vertically stretched state.

[0012] A fourth aspect of the present invention is a drawing device according to any one of aspects 1 to 3, wherein the drawing head further comprises a frame supporting the lens moving mechanism. The lens moving mechanism comprises: a guide rail fixed to the frame on one side of the lateral direction of the second lens group and extending in the vertical direction, and guiding the vertical movement of the second lens group; and a bearing seat fixed to the second lens group and in contact with the guide rail and moving along the guide rail. The force acting on the second lens group from the auxiliary support portion is directed toward the upper side and toward the lateral side.

[0013] According to a fifth aspect of the present invention, in the drawing device described in the fourth aspect, the auxiliary support portion is arranged on the one side in the lateral direction relative to the second lens group, and overlaps with the guide rail in a direction perpendicular to the up-down direction and the lateral direction.

[0014] The above-mentioned object and other objects, features, aspects and advantages will become more apparent from the following detailed description of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a perspective view showing a drawing device according to one embodiment.

[0016] Figure 2 It is a diagram showing the structure of the control unit.

[0017] Figure 3 It is a diagram showing the functional structure of the control unit.

[0018] Figure 4 It is a side view depicting the head.

[0019] Figure 5 It is a longitudinal sectional view showing the vicinity of the autofocus mechanism.

[0020] Figure 6 It is a front view showing the vicinity of the autofocus mechanism.

[0021] Figure 7 It is a top view showing the vicinity of the autofocus mechanism.

[0022] Description of reference numerals:

[0023] 1Drawing device

[0024] 5Autofocus mechanism

[0025] 9 substrates

[0026] 21 stage

[0027] 22 Stage moving mechanism

[0028] 41Description Head

[0029] 43 Illumination optical system

[0030] 44 Light modulation unit

[0031] 45 Projection optical system

[0032] 47 Frames

[0033] 51 Sensor Department

[0034] 52 Lens moving mechanism

[0035] 53 auxiliary support part

[0036] 91 Upper surface (of substrate)

[0037] 421 Light Source

[0038] 451 First lens group

[0039] 452 Second lens group

[0040] 522 Guide Rail

[0041] 523 bearing seat

[0042] 533 Coil Spring DETAILED DESCRIPTION

[0043] Figure 1 1 is a perspective view showing a drawing device 1 according to an embodiment of the present invention. The drawing device 1 is a direct drawing device that draws a pattern by irradiating a photosensitive material on a substrate 9 with light that is spatially modulated and is in the form of a substantially light beam, and scanning the irradiated area of ​​the light on the substrate 9. Figure 1 In the diagram, three mutually orthogonal directions are designated as the X direction, the Y direction, and the Z direction, and are indicated by arrows. Figure 1 In the example shown, the X direction and the Y direction are horizontal directions perpendicular to each other, and the Z direction is a vertical direction (ie, an up-and-down direction). The same is true in other drawings.

[0044] The substrate 9 is, for example, a printed circuit board in a substantially rectangular flat plate shape. On the main surface (hereinafter, also referred to as "upper surface 91") on the (+Z) side of the substrate 9, a resist film formed of a photosensitive material is provided on the copper layer. In the drawing device 1, a circuit pattern is drawn (i.e., formed) on the resist film of the substrate 9. In addition, the type and shape of the substrate 9 can be variously changed.

[0045] The drawing device 1 has a stage 21, a stage moving mechanism 22, an alignment unit 3, a drawing unit 4, and a control unit 8. The stage 21 is a roughly rectangular flat plate-shaped member arranged on the lower side (i.e., the (-Z) side) than the alignment unit 3 and the drawing unit 4. The stage 21 has a substrate holding portion 25 that holds the substrate 9 in a horizontal state from the lower side. The substrate holding portion 25 is, for example, a vacuum chuck that adsorbs and holds the lower surface of the substrate 9. The substrate holding portion 25 may have a structure other than a vacuum chuck, for example, it may be a mechanical chuck. The upper surface 91 of the substrate 9 placed on the substrate holding portion 25 is approximately perpendicular to the Z direction and approximately parallel to the X direction and the Y direction.

[0046] The stage moving mechanism 22 is a moving mechanism that moves the stage 21 relative to the alignment section 3 and the drawing section 4 in the horizontal direction (i.e., a direction roughly parallel to the upper surface 91 of the substrate 9). The stage moving mechanism 22 is installed on the upper surface of the base 11 and is supported by the base 11 from the bottom. The stage moving mechanism 22 has a first moving mechanism 23 and a second moving mechanism 24. The second moving mechanism 24 supports the stage 21 from the bottom and moves the stage 21 linearly in the X direction along the guide rail. The first moving mechanism 23 supports the second moving mechanism 24 from the bottom and moves the stage 21 linearly in the Y direction along the guide rail together with the second moving mechanism 24. The driving sources of the first moving mechanism 23 and the second moving mechanism 24 are, for example, a linear servo motor or a device in which a motor is mounted on a ball screw. The structures of the first moving mechanism 23 and the second moving mechanism 24 can be changed in various ways.

[0047] In the drawing device 1, a stage rotating mechanism that rotates the stage 21 around a rotation axis extending in the Z direction may be provided. In addition, a stage lifting mechanism that moves the stage 21 in the Z direction may be provided in the drawing device 1. As the stage rotating mechanism, for example, a servo motor may be used. As the stage lifting mechanism, for example, a linear servo motor may be used. The structures of the stage rotating mechanism and the stage lifting mechanism may be modified in various ways.

[0048] The alignment unit 3 has a plurality of alignment cameras 31. Figure 1 In the example shown, two alignment cameras 31 are arranged in the X direction, but only the alignment camera 31 on the (+X) side is shown. Each alignment camera 31 is supported above the stage 21 and the stage moving mechanism 22 by a support portion 27 provided across the stage 21 and the stage moving mechanism 22. The support portion 27 is, for example, a single metal member provided at one position in the Y direction. Figure 1 In the illustrated example, the support portion 27 is a gate-shaped member (so-called gantry) that spans the stage 21 and the stage moving mechanism 22 , and is provided upright on the upper surface of the base 11 .

[0049] exist Figure 1 In the example shown, two alignment cameras 31 are mounted on the side surface of the (+Y) side of the support portion 27. For example, one of the two alignment cameras 31 is fixed to the support portion 27, and the other alignment camera 31 can be moved in the X direction on the support portion 27. Thus, the distance in the X direction between the two alignment cameras 31 can be changed. In addition, the number of alignment cameras 31 of the alignment portion 3 may be one, or may be three or more.

[0050] Each alignment camera 31 captures an alignment mark (not shown) pre-set on the upper surface 91 of the substrate 9. In the drawing device 1, the substrate 9 is aligned (i.e., the relative position of the substrate 9 with respect to the drawing head 41 is corrected) based on the image of the alignment mark acquired by the alignment camera 31.

[0051] The drawing unit 4 has a plurality of (in Figure 1 In the example shown, there are six drawing heads 41. The plurality of drawing heads 41 have substantially the same structure. Each drawing head 41 has a light modulator that irradiates modulated (i.e., spatially modulated) light downward. Each drawing head 41 is supported by the support portion 27 above the stage 21 and the stage moving mechanism 22. Figure 1 In the example shown, six drawing heads 41 are attached to the side surface on the (-Y) side of the support portion 27. In addition, the alignment camera 31 may be supported by a support portion different from the support portion 27 to which the drawing heads 41 are attached.

[0052] exist Figure 1 In the example shown, six drawing heads 41 are arranged in a substantially straight line substantially parallel to the X direction. The positions of the six drawing heads 41 in the Y direction and the Z direction are substantially the same. Figure 1 , the illustration of the sensor unit 51 described later of each drawing head 41 is omitted. In addition, the plurality of drawing heads 41 do not necessarily need to be arranged in a straight line, and may be arranged in a staggered manner, for example. When the drawing heads 41 are arranged in a staggered manner, for example, the plurality of drawing heads 41 are arranged substantially parallel to the X direction at a first position in the Y direction, and at a second position adjacent to the (-Y) side of the first position, the drawing heads 41 are arranged between the plurality of drawing heads 41 in the X direction. In addition, in the drawing unit 4, the number of drawing heads 41 may be one, or may be two or more.

[0053] In the drawing device 1, pattern drawing on the substrate 9 is performed in a so-called multi-path method. Specifically, modulated light is irradiated onto the upper surface 91 of the substrate 9 from the plurality of drawing heads 41 of the drawing unit 4, and the substrate 9 is moved in the Y direction and passes under the drawing heads 41 by the first moving mechanism 23 of the stage moving mechanism 22. Thus, the irradiation area of ​​the light from the plurality of drawing heads 41 is scanned on the substrate 9 in the Y direction, thereby drawing the substrate 9. Next, the substrate 9 is moved in steps by a predetermined distance in the X direction by the second moving mechanism 24. Then, the substrate 9 is moved in the Y direction by the first moving mechanism 23 again, and the light is irradiated from the drawing heads 41 to the substrate 9 in parallel with the movement, thereby drawing the substrate 9. In the drawing device 1, the pattern drawing on the substrate 9 is performed by alternately irradiating the substrate 9 moving in the Y direction with light and stepping the substrate 9 in the X direction.

[0054] In the following description, the Y direction is also referred to as the "main scanning direction" or "scanning direction", and the X direction is referred to as the "sub-scanning direction". The main scanning direction and the sub-scanning direction are directions substantially parallel to the upper surface 91 of the substrate 9. In the stage moving mechanism 22, the first moving mechanism 23 is a main scanning mechanism that moves the stage 21 relative to the drawing head 41 in the main scanning direction. The second moving mechanism 24 is a sub-scanning mechanism that moves the stage 21 relative to the drawing head 41 in the sub-scanning direction.

[0055] In addition, in the drawing device 1, the drawing on the substrate 9 may be performed in a single path method (also referred to as a one-way method) in which the drawing of the pattern on the substrate 9 is completed by moving the substrate 9 only once relative to the drawing head 41 in the Y direction. In this case, when drawing the pattern, the sub-scanning (i.e., the stepping movement in the X direction) of the substrate 9 by the second moving mechanism 24 is not performed. That is, the stage moving mechanism 22 is a scanning mechanism that moves the stage 21 at least in the scanning direction relative to the drawing head 41.

[0056] The control unit 8 controls the structures such as the stage 21 , the stage moving mechanism 22 , the alignment unit 3 , and the drawing unit 4 . Figure 2 8 is a diagram showing the structure of the control unit 8. The control unit 8 has a general computer system structure including a CPU 81, a ROM 82, a RAM 83, a fixed disk 84, a display 85, an input unit 86, a reading device 87, a communication unit 88, and a bus 80. The CPU 81 performs various calculations. The ROM 82 stores basic programs. The RAM 83 stores various information. The fixed disk 84 stores information. The display 85 is a display unit that displays various information such as images. The input unit 86 has a keyboard 86a and a mouse 86b that receive input from the operator.

[0057] The reading device 87 reads information from a computer-readable recording medium 811 such as an optical disk, a magnetic disk, a magneto-optical disk, or a memory card. The display 85, the keyboard 86a, the mouse 86b, and the reading device 87 are connected to the bus 80 via the interface I / F. The communication unit 88 sends and receives signals between the components of the drawing device 1 other than the control unit 8 and external devices. The bus 80 is a signal circuit that connects the CPU 81, the ROM 82, the RAM 83, the fixed disk 84, the display 85, the input unit 86, the reading device 87, and the communication unit 88.

[0058] In the control unit 8, the program 812 is read from the recording medium 811 in advance via the reading device 87 and stored in the fixed disk 84. The program 812 may also be stored in the fixed disk 84 via a network. The CPU 81 functions as a calculation unit that performs calculation processing according to the program 812 and uses the RAM 83 and the fixed disk 84. In addition to the CPU 81, other structures that function as a calculation unit may also be adopted.

[0059] Figure 3 8 is a diagram showing a functional structure realized by the control unit 8 executing arithmetic processing according to a program 812. These functional structures include a storage unit 801, a drawing control unit 802, and a lens movement control unit 803. All or part of these functions can be realized by a dedicated circuit. In addition, these functions can be realized by a plurality of computers. Figure 3 In the functional configuration shown, the drawing control unit 802 and the lens shift control unit 803 are realized by the CPU 81 , the ROM 82 , the RAM 83 , the fixed disk 84 , and their peripheral components. The storage unit 801 is mainly realized by the RAM 83 and the fixed disk 84 .

[0060] Figure 4 This is a side view of one drawing head 41 enlarged and viewed from the (+X) side. The other drawing heads 41 also have the same Figure 4 The drawing head 41 has the same structure as the drawing head 41 shown in the figure. The drawing head 41 includes a light source unit 42, an illumination optical system 43, a light modulation unit 44, a projection optical system 45, a drawing head cover 46, a frame 47, and an autofocus mechanism 5. The light source unit 42, the illumination optical system 43, the light modulation unit 44, the projection optical system 45, and the frame 47 are housed inside the drawing head cover 46. In addition, a part of the autofocus mechanism 5 is also housed inside the drawing head cover 46. Figure 4 In order to facilitate understanding of the drawings, the cross section of the head cover 46 is represented by a dotted line, and the internal structure of the head cover 46 is represented by a solid line. Figure 4 In FIG. 1 , the support portion 27 is also shown.

[0061] exist Figure 4 In the example shown, the drawing head cover 46 is a substantially L-shaped member in a side view. The light source unit 42 is arranged inside the drawing head cover 46 at the end portion on the (+Y) side of the upper portion of the drawing head 41. The light source unit 42 has a light source 421 such as an LED (light emitting diode) or an LD (laser diode). Light emitted from the light source 421 is incident on the illumination optical system 43 along a predetermined optical axis J1 of the drawing head 41. Figure 4 In FIG. 1 , the optical axis J1 is depicted by a single-dot chain line.

[0062] The illumination optical system 43 is disposed inside the drawing head cover 46 at the upper part of the drawing head 41, on the (-Y) side of the light source unit 42. The illumination optical system 43 extends substantially parallel to the Y direction. The illumination optical system 43 has optical elements such as a plurality of lenses arranged substantially parallel to the Y direction. Figure 4 In FIG. 4 , the illustration of the plurality of lenses and the like is omitted, and the lens barrel and the like that accommodate the plurality of lenses and the like are illustrated. The illumination optical system 43 guides the light incident from the light source 421 to the light modulation unit 44. Figure 4 In the illustrated example, light that has passed through the illumination optical system 43 enters the light modulation unit 44 via the reflection mirrors 431 and 432 .

[0063] The light modulator 44 is arranged inside the drawing head cover 46 at the end of the (-Y) side of the upper part of the drawing head 41. The light modulator 44 is located on the (-Y) side of the illumination optical system 43. The light modulator 44 has a spatial light modulator that modulates light. The spatial light modulator is, for example, a DMD (Digital Micromirror Device) in which a plurality of micro-mirrors are arranged two-dimensionally. In addition, the light modulator 44 may also have a spatial light modulator other than the DMD. The light modulator 44 modulates the light guided by the illumination optical system 43 and guides it to the projection optical system 45.

[0064] The projection optical system 45 is arranged inside the drawing head cover 46 at the end of the drawing head 41 on the (-Y) side, on the (-Z) side (i.e., below) of the light modulation unit 44. The projection optical system 45 extends approximately parallel to the Z direction. The projection optical system 45 has optical elements such as a plurality of lenses arranged approximately parallel to the Z direction. Figure 4 In the figure, the illustration of the plurality of lenses and the like is omitted, and the lens barrel and the like that accommodate the plurality of lenses and the like are shown. The projection optical system 45 projects the light modulated by the light modulating unit 44 onto the upper surface 91 (refer to Figure 1 )guide.

[0065] The projection optical system 45 has a first lens group 451 and a second lens group 452. The first lens group 451 has an optical element such as a plurality of lenses arranged substantially parallel to the Z direction. The second lens group 452 has an optical element such as a single lens, or an optical element such as a plurality of lenses arranged substantially parallel to the Z direction. Figure 4 , for each of the first lens group 451 and the second lens group 452, the illustration of the plurality of lenses and the like is omitted, and the lens barrel and the like that accommodate the plurality of lenses and the like are illustrated. The first lens group 451 and the second lens group 452 are arranged substantially parallel to the Z direction. The first lens group 451 is located on the (+Z) side of the second lens group 452.

[0066] In the projection optical system 45 , the light modulated by the light modulator 44 enters the first lens group 451 and is guided by the first lens group 451 to the second lens group 452 . The second lens group 452 guides the light guided by the first lens group 451 to the upper surface 91 of the substrate 9 .

[0067] The first lens group 451 and the second lens group 452 are mounted on the side surface of the (-Y) side of the frame 47, which is a roughly quadrangular prism-shaped member extending in the Z direction. The first lens group 451 and the second lens group 452 are mounted on the frame 47 in a manner that allows them to move in the Z direction. The first lens group 451 is raised and lowered when the magnification of the image formed on the substrate 9 is changed, and is not raised and lowered during the pattern drawing on the substrate 9. The second lens group 452 is raised and lowered by the autofocus mechanism 5 during the pattern drawing on the substrate 9. The frame 47 is a supporting member that supports the first lens group 451 and the second lens group 452. The frame 47 is fixed to the inner side of the drawing head cover 46, for example, and is indirectly supported by the support portion 27 via the drawing head cover 46. The frame 47 may be a part of the drawing head cover 46.

[0068] In the drawing head 41, the focus position of the light emitted from the drawing head 41 to the substrate 9 is adjusted in the Z direction by moving the second lens group 452 in the Z direction in the projection optical system 45. The focus position is a position where the light emitted from the drawing head 41 to the substrate 9 is focused on the (-Z) side of the drawing head 41. In other words, the focus position is a position where the light passing through the second lens group 452 from the (+Z) side to the (-Z) side is focused on the (-Z) side of the second lens group 452. In other words, the focus position is a position where the image of the micromirror of the DMD of the light modulation unit 44 is formed on the (-Z) side of the second lens group 452.

[0069] In the projection optical system 45, the first lens group 451 is accommodated inside the drawing head cover 46. In addition, the second lens group 452 is also accommodated inside the drawing head cover 46. The lower end of the drawing head cover 46 is open. The lower end of the second lens group 452 (that is, the lower end of the projection optical system 45) can protrude downward from the lower end opening of the drawing head cover 46.

[0070] The autofocus mechanism 5 is arranged near the second lens group 452 of the projection optical system 45. The autofocus mechanism 5 moves the second lens group 452 in the Z direction (i.e., moves up and down) according to the change of the distance between the projection optical system 45 and the substrate 9, thereby adjusting the focus position of the light emitted from the drawing head 41 to the substrate 9 in the Z direction.

[0071] Figure 5 It is a magnified representation Figure 4 The drawing head 41 shown is a longitudinal sectional view of the second lens group 452 of the projection optical system 45 and the vicinity of the autofocus mechanism 5. Figure 5 In FIG. 1 , a part of the structure is shown on the side. Figure 5 In the figure, the structure closer to the inside than the cross section is also shown with thin lines. Figure 6 This is a front view of the second lens group 452 and the vicinity of the autofocus mechanism 5 as viewed from the (-Y) side. Figure 7 This is a top view of the second lens group 452 and the vicinity of the autofocus mechanism 5 as viewed from the (+Z) side. Figure 7 In the figure, the first lens group 451 is omitted, and the frame 47 is described using a cross section at the position of an opening 471 described later.

[0072] The autofocus mechanism 5 includes a sensor unit 51, a lens shifting mechanism 52, and an auxiliary support unit 53. The sensor unit 51 is mounted on the second lens group 452 of the projection optical system 45. Specifically, the sensor unit 51 is fixed to the lower end of the lens barrel of the second lens group 452 (i.e., the end on the (-Z) side). The sensor unit 51 measures the distance between the lower end of the second lens group 452 and the upper surface 91 of the substrate 9 on the stage 21 (see Figure 1 ) in the Z direction (hereinafter referred to as “projection distance”).

[0073] The sensor unit 51 includes a light emitting unit 511, a light receiving unit 512, and a sensor support unit 513. The sensor support unit 513 is, for example, a substantially cylindrical member extending substantially parallel to the Z direction. The sensor support unit 513 is located on the (-Z) side of the second lens group 452 outside the drawing head cover 46 and is fixed to the lower end of the lens barrel of the second lens group 452. Figure 5 In the example shown, the end of the light emitting unit 511 on the (-Z) side of the sensor support unit 513 is fixed to the end of the (+Y) side of the sensor support unit 513. In addition, the end of the light receiving unit 512 on the (-Z) side of the sensor support unit 513 is fixed to the end of the (-Y) side of the sensor support unit 513. Light emitted from the light emitting unit 511 to the (-Y) side and the (-Z) side is reflected by the upper surface 91 of the substrate 9 and received by the light receiving unit 512. The light receiving unit 512 is, for example, a line sensor. In the sensor unit 51, the above-mentioned projection distance is obtained based on the light receiving position in the light receiving unit 512 of the reflected light from the substrate 9.

[0074] The lens moving mechanism 52 is mounted on the frame 47 and supported by the frame 47. The lens moving mechanism 52 connects the second lens group 452 and the frame 47. The lens moving mechanism 52 supports the second lens group 452 and moves the second lens group 452 in the Z direction. The lens moving mechanism 52 has a driving portion 521, a guide rail 522, a bearing seat 523, and a lens supporting portion 524.

[0075] The guide rail 522 is fixed to the side surface of the (-Y) side of the frame 47 on the (+Y) side of the second lens group 452. When the Y direction is referred to as the "lateral direction", the guide rail 522 is arranged between the second lens group 452 and the frame 47 in the lateral direction. The guide rail 522 has two rails arranged in the X direction. The two rails extend substantially parallel to the Z direction.

[0076] The bearing seat 523 is a bearing member connected to the guide rail 522 from the (-Y) side and is movable in the Z direction along the guide rail 522. Figures 5 to 7 In the example shown, two bearing seats 523 are respectively connected to two rails of the guide rail 522. Each bearing seat 523 is, for example, a substantially rectangular parallelepiped or substantially flat plate-shaped member. Each bearing seat 523 contacts the guide rail 522 and moves smoothly along the guide rail 522 in the Z direction.

[0077] The lens support portion 524 is a component fixed to the bearing seat 523 and supports the second lens group 452. Figures 5 to 7 In the example shown, the lens support portion 524 has a first portion 525, a second portion 526, and a third portion 527. The first portion 525 and the second portion 526 are integrally connected components arranged on the (-Y) side of the bearing seat 523. The first portion 525 and the second portion 526 are substantially L-shaped when viewed from the side. The first portion 525 is a substantially flat plate-shaped portion extending substantially parallel to the Z direction and substantially perpendicular to the Y direction. Two bearing seats 523 are fixed to the side surface of the first portion 525 on the (+Y) side.

[0078] The second portion 526 protrudes from the end of the (-Z) side of the first portion 525 toward the (-Y) side. The second portion 526 is a substantially flat plate-shaped portion extending substantially parallel to the Y direction and substantially perpendicular to the Z direction. A through hole penetrating in the Z direction is provided in the second portion 526. The lens barrel of the second lens group 452 is inserted into the through hole, whereby the second lens group 452 is supported by the lens support portion 524. That is, the second lens group 452 is indirectly fixed to the bearing seat 523 via the second portion 526 and the first portion 525 of the lens support portion 524.

[0079] The third portion 527 is a portion that protrudes from the side surface of the first portion 525 on the (+Y) side toward the (+Y) direction at the approximate center of the first portion 525 in the X direction and the Z direction. The third portion 527 is a roughly columnar or cylindrical portion that extends roughly parallel to the Y direction. The third portion 527 is inserted into the interior of the frame 47 from the opening 471 provided between the two rails of the guide rail 522 on the side surface of the (-Y) side of the frame 47. The end of the third portion 527 on the (+Y) side is connected to the drive portion 521 inside the frame 47. The weight of the lens support portion 524 and the second lens group 452 is mainly supported by the drive portion 521. In addition, the bearing seat 523 is connected to the guide rail 522 in a manner that the friction therebetween is extremely small, and therefore, the guide rail 522 hardly supports the weight of the lens support portion 524 and the second lens group 452.

[0080] The driving unit 521 extends along the Z direction inside the frame 47 and is fixed to the frame 47. In other words, the driving unit 521 is supported by the support unit 27 via the frame 47. The driving unit 521 is, for example, a combination of an electric motor and a ball screw. The end of the (+Y) side of the third portion 527 is fixed to a movable part that can move in the Z direction in the driving unit 521. When the movable part moves in the Z direction in the driving unit 521, the lens support unit 524 fixed to the movable part, and the second lens group 452 and the bearing seat 523 fixed to the lens support unit 524 are guided by the guide rail 522 and move in the Z direction. In addition, the driving unit 521 can be changed to various forms such as a linear servo motor and a cylinder.

[0081] exist Figure 1 In the drawing device 1 shown in the figure, when the above-mentioned pattern drawing is performed on the substrate 9, the drawing control unit 802 controls the drawing control unit 802 based on the storage unit 801 (refer to Figure 3 ) is used to control the light modulation unit 44 and the stage moving mechanism 22, thereby irradiating the modulated light onto the upper surface 91 of the substrate 9 moving in the Y direction to draw the pattern.

[0082] In the drawing device 1, while the above-mentioned pattern is being drawn on the substrate 9, the drawing is continuously performed by Figures 5 to 7The above-mentioned measurement of the projection distance is performed by the sensor unit 51 shown in FIG. The projection distance measured by the sensor unit 51 is output to the lens movement control unit 803. The lens movement control unit 803 controls the lens movement mechanism 52 based on the output from the sensor unit 51. As a result, the position of the second lens group 452 in the Z direction is adjusted by the lens movement mechanism 52, and the focus position of the light emitted from the drawing head 41 to the substrate 9 is adjusted in the Z direction to be aligned with the upper surface 91 of the substrate 9. As a result, even if the substrate 9 is deformed such as warping or there are unevenness on the upper surface 91 of the substrate 9, the above-mentioned focus position can be aligned with the upper surface 91 of the substrate 9, so that high-precision drawing can be achieved.

[0083] Figures 5 to 7 The auxiliary support portion 53 shown is arranged on the (+Z) side of the lens support portion 524 on the (+Y) side of the second lens group 452, and assists the lens moving mechanism 52 in supporting the second lens group 452 (specifically, the drive portion 521 supports the lens support portion 524 and the second lens group 452). The auxiliary support portion 53 has an elastic member, namely a coil spring 533, extending in the Z direction between the two rails of the guide rail 522. Figure 5 In the example shown, the coil spring 533 extends substantially parallel to the Z direction and partially overlaps the guide rail 522 in the X direction (i.e., in a side view). Specifically, the portion of the (+Y) side of the coil spring 533 overlaps the guide rail 522 in a side view. In addition, the entire coil spring 533 may overlap the guide rail 522 in the X direction.

[0084] The lower end of the coil spring 533 is connected to a locking metal piece that protrudes from the upper end of the first portion 525 of the lens support portion 524 to the (+Y) side (i.e., protrudes toward the frame 47). In other words, the lower end of the auxiliary support portion 53 is indirectly connected to the second lens group 452 via the locking metal piece and the lens support portion 524. The upper end of the coil spring 533 is connected to a locking metal piece that protrudes from the side surface of the (-Y) side of the frame 47 to the (-Y) side (i.e., protrudes toward the second lens group 452). In other words, the upper end of the auxiliary support portion 53 is indirectly connected to the frame 47 via the locking metal piece.

[0085] The coil spring 533 is connected to the frame 47 and the lens support portion 524 in a state of being stretched in the Z direction. In other words, the auxiliary support portion 53 is connected to the frame 47 in a state of being elastically deformed in the up-down direction, and is connected to the second lens group 452 via the lens support portion 524. In addition, the coil spring 533 is always in a stretched state when the lens support portion 524 and the second lens group 452 are located at any position within the movable range in the Z direction.

[0086] Therefore, regardless of the position of the lens support 524 and the second lens group 452 in the Z direction, the restoring force of the auxiliary support 53 acts as a force to pull the lens support 524 and the second lens group 452 upward to the (+Z) side. That is, the auxiliary support 53 continuously acts an upward force on the lens support 524 and the second lens group 452, and the weight of the lens support 524 and the second lens group 452 applied to the drive unit 521 is reduced. As a result, when the drive unit 521 moves the lens support 524 and the second lens group 452 in the vertical direction, the downward load (i.e., the driving load) applied to the drive unit 521 by the weight of the lens support 524 and the second lens group 452 is reduced. As a result, when the second lens group 452 is raised or lowered (especially when it rises), the vibration of the drive unit 521 and the second lens group 452 is suppressed, and the raising and lowering of the second lens group 452 is smoothly performed. This vibration is a relatively small vibration, hereinafter also referred to as "micro vibration".

[0087] In the following description, the upper end of the first portion 525 of the lens support portion 524 (i.e., the portion of the lens support portion 524 where the restoring force of the auxiliary support portion 53 acts) is referred to as the "first connection portion 531". In addition, the portion of the frame 47 where the restoring force of the auxiliary support portion 53 acts is also referred to as the "second connection portion 532". Figure 5 In the example shown, the first connection portion 531 is located closer to the (+Z) side than the contact portion between the bearing seat 523 and the guide rail 522. In addition, the second connection portion 532 is located closer to the (+Z) side and closer to the (+Y) side than the first connection portion 531. Therefore, the force acting on the lens support portion 524 and the second lens group 452 from the auxiliary support portion 53 is directed toward the (+Z) side and toward the (+Y) side. In addition, the force generated by Figure 5 The clockwise torque (hereinafter also referred to as “auxiliary torque”) acts on the contact portion of the guide rail 522 that contacts the bearing seat 523.

[0088] In the drawing head 41, as described above, the bearing seat 523 is connected to the guide rail 522 from the (-Y) side, and the lens support 524 and the second lens group 452 are fixed to the side surface of the (-Y) side of the bearing seat 523. Therefore, the contact portion of the guide rail 522 that contacts the bearing seat 523 is affected by the weight of the second lens group 452 and the lens support 524. Figure 5The moment in the counterclockwise direction (hereinafter also referred to as "weight moment") of the second lens group 452 and the lens support 524 is reduced by the auxiliary moment of the auxiliary support 53. Therefore, when the lens support 524 and the second lens group 452 move in the up-down direction, the friction of the contact portion between the bearing seat 523 and the guide rail 522 is reduced. As a result, when the second lens group 452 is raised or lowered, the micro-vibration of the bearing seat 523 and the second lens group 452 is further suppressed, so that the raising and lowering of the second lens group 452 is smoother.

[0089] As described above, the drawing device 1 for drawing a pattern by irradiating light onto the substrate 9 includes the stage 21, the drawing head 41, and the stage moving mechanism 22. The stage 21 holds the substrate 9. The drawing head 41 irradiates the modulated light onto the substrate 9. The stage moving mechanism 22 moves the stage 21 relative to the drawing head 41 in a direction parallel to the upper surface 91 of the substrate 9. The drawing head 41 includes an illumination optical system 43, a light modulation unit 44, a projection optical system 45, and an automatic focusing mechanism 5. Light emitted from the light source unit 42 is incident on the illumination optical system 43. The light modulation unit 44 modulates the light guided by the illumination optical system 43. The projection optical system 45 guides the light modulated by the light modulation unit 44 to the substrate 9. The automatic focusing mechanism 5 adjusts the focus position of the light emitted from the drawing head 41 according to the change in the distance between the projection optical system 45 and the substrate 9.

[0090] The projection optical system 45 includes a first lens group 451 and a second lens group 452. The light modulated by the light modulation unit 44 is incident on the first lens group 451. The second lens group 452 guides the light guided by the first lens group 451 to the substrate 9. The autofocus mechanism 5 includes a sensor unit 51, a lens shift mechanism 52, and an auxiliary support unit 53. The sensor unit 51 measures the distance between the second lens group 452 and the substrate 9 in the vertical direction (i.e., the projection distance). The lens shift mechanism 52 supports the second lens group 452. The lens shift mechanism 52 moves the second lens group 452 in the vertical direction (in the above example, the Z direction) based on the output from the sensor unit 51, thereby adjusting the focus position of the light emitted from the drawing head 41. The auxiliary support unit 53 continuously applies an upward force to the second lens group 452, thereby assisting the lens shift mechanism 52 in supporting the second lens group 452.

[0091] As described above, the drive load of the lens moving mechanism 52 can be reduced when the second lens group 452 is raised or lowered. As a result, microvibration of the second lens group 452 when raised or lowered can be suppressed, thereby suppressing a decrease in the image drawing accuracy caused by the microvibration.

[0092] As described above, preferably, the drawing head 41 further includes a frame 47 that supports the lens moving mechanism 52. In addition, preferably, the auxiliary support portion 53 includes an elastic member that connects the frame 47 and the second lens group 452 in an elastically deformed state. Thereby, it is possible to simplify the structure of the auxiliary support portion 53. That is, in the drawing device 1, it is possible to reduce the driving load acting on the lens moving mechanism 52 with a simple structure.

[0093] As described above, preferably, the elastic member is a coil spring 533 extending in the vertical direction. In addition, preferably, the coil spring 533 connects the frame 47 and the second lens group 452 in a state of being stretched in the vertical direction. Thus, the structure of the auxiliary support portion 53 can be further simplified. That is, the driving load acting on the lens moving mechanism 52 can be reduced with a simpler structure.

[0094] As described above, preferably, the drawing head 41 further includes a frame 47 that supports the lens moving mechanism 52. In addition, preferably, the lens moving mechanism 52 includes a guide rail 522 and a bearing seat 523. The guide rail 522 is fixed to the frame 47 on one side of the second lens group 452 in the lateral direction (in the above example, the (+Y) side) and extends in the up-down direction. The guide rail 522 guides the up-down movement of the second lens group 452. The bearing seat 523 is fixed to the second lens group 452, and contacts the guide rail 522 and moves along the guide rail 522. Preferably, the force acting on the second lens group 452 from the auxiliary support portion 53 is directed toward the upper side and toward the above-mentioned one side in the lateral direction. Thus, as described above, the weight moment acting on the guide rail 522 due to the weight of the second lens group 452 and the like can be reduced by the auxiliary moment of the auxiliary support portion 53. As a result, the microvibration of the second lens group 452 when it is raised and lowered can be further suppressed, thereby further suppressing the reduction in drawing accuracy caused by the microvibration.

[0095] As described above, preferably, the auxiliary support portion 53 is arranged closer to the above-mentioned side in the lateral direction than the second lens group 452, and overlaps with the guide rail 522 in the direction perpendicular to the up-down direction and the lateral direction (in the above-mentioned example, the X direction). As a result, the above-mentioned auxiliary moment of the auxiliary support portion 53 can be increased, so that the weight moment acting on the guide rail 522 due to the weight of the second lens group 452 and the like can be further reduced. As a result, the micro-vibration when the second lens group 452 is raised and lowered can be further suppressed, so that the reduction in the drawing accuracy caused by the micro-vibration can be further suppressed. In addition, the automatic focusing mechanism 5 can also be miniaturized, and the drawing head 41 and the drawing device 1 can be miniaturized.

[0096] The above-described drawing device 1 can be modified in various ways.

[0097] For example, the position of the coil spring 533 of the auxiliary support portion 53 is not limited to the above example, and various changes can be made. For example, the coil spring 533 does not necessarily need to overlap with the guide rail 522 when viewed from the side, and can also be arranged at a position closer to the (-Y) side than the guide rail 522. In addition, the coil spring 533 does not necessarily need to be arranged to extend substantially parallel to the Z direction, and can also be arranged obliquely relative to the Z direction.

[0098] In the above example, the lower end of the coil spring 533 is connected to the upper end of the first portion 525 of the lens support portion 524, but may be connected to other positions of the lens support portion 524. In addition, the lower end of the coil spring 533 does not necessarily need to be indirectly connected to the second lens group 452 via the lens support portion 524, and may be directly connected to the second lens group 452.

[0099] The force acting on the second lens group 452 from the auxiliary support part 53 does not necessarily need to be directed toward the (+Z) side and toward the (+Y) side, and various changes can be made. For example, the force acting on the second lens group 452 from the auxiliary support part 53 can also be directed toward the (+Z) side substantially parallel to the Z direction.

[0100] In the auxiliary support part 53, other elastic members such as leaf springs and flat rubber may be connected to the frame 47 and the second lens group 452 in a stretched state instead of the coil springs 533. The elastic member may be made of metal or other materials (such as resin).

[0101] The elastic member provided in the auxiliary support part 53 does not necessarily need to be connected to the second lens group 452 in a stretched state to pull up the second lens group 452, but may be connected to the second lens group 452 in a compressed state to push up the second lens group 452. For example, a coil spring compressed in the vertical direction may be connected between the lower end of the frame 47 and the third portion 527 of the lens support part 524 inside the frame 47, and the third portion 527 may be pushed up by the coil spring, thereby assisting the driving part 521 in supporting the second lens group 452.

[0102] The bearing holder 523 does not necessarily need to be indirectly fixed to the second lens group 452 via the lens support portion 524, and may be directly fixed to the second lens group 452. In the drawing head 41, the lens support portion 524 may be omitted.

[0103] The shape of the drawing head cover 46 can be variously changed, and for example, the drawing head cover 46 may be a member extending substantially parallel to the Z direction. In this case, the illumination optical system 43 and the light source unit 42 are arranged on the (+Z) side of the light modulation unit 44, for example.

[0104] exist Figure 4In the example shown, one light source 421 is depicted in the light source unit 42, but the number of light sources 421 provided in the light source unit 42 may be plural. For example, a plurality of light sources 421 emitting light of different wavelengths may be provided in the light source unit 42. In this case, when a pattern is depicted on the substrate 9, one or more of the plurality of light sources 421 are selected and used according to the type of photosensitive material on the substrate 9, etc. In addition, the light source 421 provided in the light source unit 42 is not limited to LED and LD, and various types of light sources may be used. In addition, the light source unit 42 may also be provided outside the drawing head 41. In this case, the light emitted from the light source unit 42 is guided to the drawing head 41 via an optical fiber or the like.

[0105] The stage moving mechanism 22 does not necessarily need to move the stage 21 , and for example, may move the plurality of drawing heads 41 in a direction parallel to the upper surface 91 of the substrate 9 above the fixed stage 21 .

[0106] The substrate 9 to be drawn in the drawing device 1 is not necessarily limited to a printed wiring board. In the drawing device 1, for example, a circuit pattern may be drawn on a semiconductor substrate, a glass substrate for a flat panel display device such as a liquid crystal display device or a plasma display device, a glass substrate for a photomask, a substrate for a solar cell panel, or the like.

[0107] The configurations in the above-described embodiment and various modifications may be appropriately combined as long as they do not contradict each other.

[0108] Although the present invention has been described and illustrated in detail, the foregoing description is illustrative rather than restrictive. Therefore, it can be said that many modifications and ways are possible without departing from the scope of the present invention.

Claims

1. A drawing device for drawing a pattern by irradiating light onto a substrate, wherein: have: a stage, holding the substrate; an imaging head for irradiating the modulated light onto the substrate; and a stage moving mechanism for moving the stage relative to the drawing head in a direction parallel to the upper surface of the substrate, The drawing head has: An illumination optical system, incident with light emitted from a light source; a light modulation unit that modulates the light guided by the illumination optical system; a projection optical system that guides the light modulated by the light modulator toward a substrate; and an automatic focusing mechanism for adjusting a focus position of light emitted from the drawing head according to a change in the distance between the projection optical system and the substrate, The projection optical system comprises: A first lens group, into which the light modulated by the light modulating unit is incident; as well as a second lens group, directing the light directed by the first lens group toward the substrate, The automatic focusing mechanism comprises: A sensor unit for measuring a distance between the second lens group and the substrate in a vertical direction; a lens moving mechanism that supports the second lens group and moves the second lens group in a vertical direction based on an output from the sensor section, thereby adjusting the focus position of the light emitted from the drawing head; as well as The auxiliary support part enables an upward force to continuously act on the second lens group, thereby assisting the lens moving mechanism in supporting the second lens group.

2. The drawing device according to claim 1, wherein: The drawing head also has a frame supporting the lens moving mechanism. The auxiliary support portion includes an elastic member connecting the frame and the second lens group in an elastically deformed state.

3. The drawing device according to claim 2, wherein: The elastic member is a coil spring extending in the up-down direction. The coil spring connects the frame and the second lens group in a state of being stretched in the up-down direction.

4. The drawing device according to any one of claims 1 to 3, wherein: The drawing head also has a frame supporting the lens moving mechanism. The lens moving mechanism has: A guide rail, fixed to the frame at one lateral side of the second lens group and extending in the up-down direction, and guiding the up-down movement of the second lens group; as well as A bearing seat is fixed to the second lens group and contacts the guide rail and moves along the guide rail. The force acting on the second lens group from the auxiliary support portion is directed upward and toward the one side in the lateral direction.

5. The drawing device according to claim 4, wherein: The auxiliary support portion is arranged closer to the one side in the lateral direction than the second lens group, and overlaps with the guide rail in a direction perpendicular to the up-down direction and the lateral direction.

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