TWI660246B - Drawing device - Google Patents

Abstract

The present invention provides a drawing device including a drawing table on which a substrate is placed, and an exposure drawing section that moves relative to the drawing table and draws a pattern on the substrate of the drawing table. The position error of the alignment mark formed on the substrate by the drawing device is small, and the plane accuracy of the substrate is not impaired. The drawing table includes: a plurality of reference marks for setting a position reference with respect to the exposure drawing part; and a plurality of mark forming means for forming an alignment mark on a back surface of a substrate placed on the drawing table. And it is located in a specific position with respect to each reference mark.

Description

Drawing device

The present invention relates to a drawing device for drawing patterns on the front and back surfaces of a flat substrate such as an electronic circuit substrate, a glass substrate for an LCD, and a glass substrate for a PDP.

In recent years, a direct exposure device (drawing device) has emerged on the market. This type of direct exposure device directly irradiates the front and back sides of a substrate with drawing light set in a positional relationship with each other without using a transfer mask to draw patterns. When performing such double-sided exposure, while pattern-exposing the surface (the first surface) (or before the exposure), the rear surface (the second surface) is exposed (formed) with multiple alignment marks, and then the substrate is flipped When pattern exposure is performed on the front surface and the back surface (second surface), the pattern exposure position is set using the alignment mark formed on the second surface as a reference (Patent Documents 1 and 2). Specifically, the alignment mark uses indicators such as a circular pattern or a cross with a diameter of less than 2 mm, and is generally set optically as an image (spontaneous color image) using the spontaneous color of a photoresist to be exposed. Corner of the substrate.

[Advanced technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 2009-294337

Patent Document 2: Japanese Patent Application Publication No. 2013-213852

However, the drawing apparatuses of Patent Documents 1 and 2 are provided with a mark formation means (alignment mark formation means, mark exposure device) movable with respect to a drawing table on which a substrate is placed, and the mark formation means with respect to the drawing table (on which a substrate is placed) ) Move to form an alignment mark on the back of the substrate. Therefore, due to mechanical errors that cannot be avoided by the moving mechanism of the mark forming means, there is a possibility that a position error of the alignment mark may occur. If there is an error in the formation position of the alignment mark, the drawing pattern on the second side and the drawing image on the first side cannot be correctly integrated. Or, when dimensional correction such as stretching of the drawing surface is performed, a correction different from the actual stretching of the substrate is caused.

In conventional devices, since it is necessary to provide a marker forming means capable of adjusting the position with respect to the drawing table, it is impossible to avoid an increase in the size of the entire device. Further, in Patent Document 2, an escape portion (a groove portion) of the mark forming means is provided on the surface of the drawing table in order to move the mark forming means. In this way, because this escape portion cannot support the back surface of the substrate, it may adversely affect the drawing accuracy of the pattern (planar accuracy of the substrate).

Therefore, an object of the present invention is to provide a drawing device that has less positional errors in alignment marks formed on a substrate and does not impair the plane accuracy of the substrate.

The present invention regards the fact that the mark forming means in the conventional drawing device can be moved relative to the drawing table on which the substrate is placed as the cause of the error in the formation position of the alignment mark. Put in If alignment marks are directly formed on the back surface of the substrate on the table, errors can be prevented.

That is, the drawing device of the present invention includes: a drawing table on which a substrate is placed; and an exposure drawing section that moves with respect to the drawing table and draws a substrate on the drawing table, wherein the drawing table includes: a plurality of A reference mark for setting a position reference with respect to the exposure drawing part; and a plurality of mark formation means for forming an alignment mark on a back surface of the substrate placed on the drawing table and positioned relative to the reference marks Specific location. The drawing table includes a table body, and a cover plate fixed to the table body so as to cover the table body. The mark forming means is composed of at least one through hole penetrating through the cover plate and a mark forming light source fixed on the table body. The mark-forming light source emits mark-forming light in a shape of the through-hole from the through-hole.

In the drawing table, the reference mark has at least one through hole penetrating through the cover and a visible light source fixed to the table body, wherein the visible light source emits visible light from the through hole as a point mark.

The through hole forming the mark forming means may have a plurality of through-holes formed in the cover plate at a predetermined interval along a relative movement direction of the drawing table and the exposure drawing portion. The table body can include the mark-forming light source that emits the mark-forming light from the through-holes selected according to the substrate size from the plurality of through-holes.

Specifically, the reference mark and the mark forming means can be located on two opposite sides of the peripheral edge portion of the substrate placed on the drawing table, and each has a pair.

The exposure and drawing section may include an imaging means for imaging the reference mark or the alignment mark. The drawing of the surface of the substrate can be performed in accordance with the shooting The coordinate system set based on the position information of the fiducial mark of the shooting is implemented. The drawing of the pattern on the back surface of the substrate after the front surface and the back surface of the substrate is reversed can be implemented by a coordinate system set according to the position information of the alignment mark photographed by the photographing means.

This fiducial mark is a point mark from a visible light source in one Embodiment.

In the present invention, since the drawing table on which the substrate is placed includes a mark forming means for forming alignment marks on the back surface of the substrate, there is no mechanical error (such as a movement error of the mark forming means) in the formation position of the alignment mark. According to the present invention, the position of a pattern drawn on the front and back surfaces of a substrate can be aligned with high accuracy while maintaining a simple structure. In addition, the surface of the drawing table can be kept smooth, and the substrate to be placed can be sucked and held with the same flatness up to the peripheral portion.

11‧‧‧ substrate

12‧‧‧Gate

13‧‧‧ sliding section

14‧‧‧ track

15‧‧‧painting table

15c‧‧‧Attraction connector

15P‧‧‧ Cover

15Q‧‧‧Table body

15r‧‧‧ recess

15v‧‧‧ suction hole

17‧‧‧ substrate bead

18‧‧‧Control device

19‧‧‧Vacuum source

20, 20a, 20b‧‧‧‧Light source department

21‧‧‧UV Light

22‧‧‧The first total reflection mirror

23‧‧‧ condenser lens

24‧‧‧ 2nd Total Mirror

25‧‧‧Flying Eye Micro Lenses

30‧‧‧Exposure and Drawing Department

33‧‧‧The first projection lens

34‧‧‧Reflector

36‧‧‧DMD components

37‧‧‧ 2nd lens group

41‧‧‧ fiducial mark

41h‧‧‧ fiducial mark hole

41j‧‧‧ fiducial mark forming light source

41k‧‧‧Reflective element

42‧‧‧mark formation means

42h‧‧‧Alignment mark hole

42j‧‧‧Alignment mark to form light source

43‧‧‧circuit board

100‧‧‧ depicting device

AC‧‧‧ pointed at the camera

AM‧‧‧Alignment mark

F‧‧‧ frame

L‧‧‧ text

W‧‧‧ substrate

FIG. 1 is a perspective view of the overall structure of a drawing device of the present invention.

Fig. 2 is an exploded perspective view of an embodiment of a drawing table of the drawing device of Fig. 1.

Figure 3 is a plan view depicting the table.

FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3.

Fig. 5 is a schematic plan view when the substrate surface (first surface) is drawn.

FIG. 6 is a schematic plan view when the substrate is drawn on the rear surface (second surface) of the substrate.

FIG. 1 is a perspective view of the entire structure of the drawing device 100 of the present invention. Illustration. The drawing device 100 includes a base 11, gates 12 erected from both sides of the base 11, and an exposure drawing unit 30 supported by the gates 12.

A drawing table 15 is arranged on the base 11, and a substrate W coated with a photosensitive material on the front and rear sides is placed. This drawing table 15 can be moved in the X direction along the track 14 by, for example, a linear motor moving means. Hereinafter, a direction perpendicular to the X direction in a horizontal plane is referred to as a Y direction, and a direction perpendicular to the X direction in a vertical plane is referred to as a Z direction.

A slide section 13 extending in the Y direction is provided in front of the exposure drawing section 30, and a pair of alignment cameras (shooting means) AC separated from each other in the Y direction are provided on the slide section 13. The sliding portion 13 is driven by a linear motor or a stepping motor to move the alignment camera AC to an arbitrary position in the Y direction.

The exposure drawing section 30 includes a light source section 20. The light source unit 20 is composed of two light source units 20a and 20b having the same internal structure. Since the light source section 20a and the light source section 20b have the same structure, the light source section 20a will be described as a representative.

The light source unit 20a is composed of a UV lamp 21, a first total reflection mirror 22, a condenser lens 23, a second total reflection mirror 24, a fly-eye microlens 25, and an opening (not shown). The light source unit 20a includes a UV lamp 21, and the UV lamp 21 emits ultraviolet light mixed with various wavelengths from 365 nm to 440 nm.

The ultraviolet light emitted from the UV lamp 21 is irradiated in the sky direction (+ Z axis direction) by the elliptical mirror 26. The first total reflection mirror 22 changes the irradiation direction to the horizontal direction, the condenser lens 23 collects light, and the second total reflection mirror 24 Change the irradiation direction to the ground direction (-Z axis direction). The ultraviolet light whose irradiation direction is changed passes through the fly-eye microlens 25 and the opening to become a divergent light beam. The light beam is incident on eight DMD (digital micromirror device) elements 36 through eight first projection lenses 33 and eight mirrors 34, and becomes Controlled light beam. This controlled light beam is irradiated to the substrate W after passing through the second lens group 37 to adjust the exposure and drawing magnification of the transmission. That is, the drawing device 100 controls the ultraviolet light of the light source section 20 a and the light source section 20 b in accordance with the drawing data in which a desired exposure image is stored in advance.

The drawing table 15 includes a table body (lower table) 15Q and a cover plate 15P on the table body 15Q. Figures 2 to 4 show details depicting table 15. The appearance of the drawing table 15 is a cube extending along three planes orthogonal to XYZ. The dimensions of the table body 15Q and the cover plate 15P in the X direction and the Y direction are the same, and the thickness of the cover plate 15P in the Z direction is thinner than the table body 15Q. The table body 15Q and the cover plate 15P can be disassembled as shown in FIG. 2 in outline, and the drawing table 15 is fixed in a regular position by, for example, a position determination device and an adsorption device (not shown) (FIG. 1, 3, Figure 4).

Four corners of the substrate mounting surface of the rectangular drawing table 15 are provided with a reference mark 41 and mark forming means 42 corresponding to each reference mark 41 and for forming an alignment mark. In other words, the drawing table 15 is provided with a plurality of reference marks 41 and a plurality of mark formation means 42 corresponding to the reference marks 41.

Each reference mark 41 is formed by one reference mark hole (through-hole) 41h formed in the cover plate 15P and a reference mark forming light source 41j supported by the table top body 15Q. The mark formation means 42 are formed by a plurality of (four through-holes) alignment mark holes 42h formed in the cover plate 15P and four corresponding to each alignment mark hole 42h and supported by the desktop body 15Q. The alignment mark forming light source 42j is formed. The reference mark forming light source 41j is composed of a red (visible light) LED, and the light reflected by the reflective element 41k is emitted from the reference mark hole 41h in the Z direction (aligned with the camera AC direction). Alignment mark forming light source 42j is made of ultraviolet LED The composition will be directly emitted from the alignment mark hole 42h in the Z direction. The reference mark forming light source 41j and the alignment mark forming light source 42j are fixed to a circuit board 43 (FIG. 4), and the circuit board 43 and the reflective element 41k are disposed in a recess 15r formed in the table body 15Q.

One reference mark hole 41h (reference mark forming light source 41j) and four alignment mark holes 42h (alignment mark forming light source 42j) are aligned in the X direction so that the same alignment camera AC mounted on the exposure drawing section 30 Shooting is easier. As shown in FIGS. 3 and 4, in the example of the figure, the intervals of the alignment mark holes 42 h of the mark forming means 42 are the same. The reference marks 41 are aligned with the intervals of the mark holes 42 h with respect to these mark forming means 42. The above distances are separated.

The positional relationship between one reference mark 41 and four mark forming means 42 is fixed on the drawing table 15. The mutual positional relationship (coordinate system on the XY plane) can be strictly identified. Therefore, finding the mark position by the alignment camera AC shooting mark formation means 42 (reference mark 41) is equivalent to finding the position of the reference mark 41 (alignment mark formed by the mark formation means 42).

In addition, the reference marks 41 that depict the four corners on the table 15 are arranged outside the mark formation means 42, and a substrate bead 17 is provided between the reference marks 41 and the mark formation means 42. Since the substrate bead 17 supports the edges of the substrate W placed on the drawing table 15 (both edges in the X direction), at least the surface of the drawing table 15 can be moved in the separation direction (Z direction).

Since there are many kinds of planar sizes of the substrate W placed on the drawing table 15, the substrate bead 17 can also be moved in the X direction. However, the substrate W does not protrude beyond the substrate bead 17 to the direction of the reference mark 41. That is, regardless of the size of the substrate W placed on the drawing table 15, the reference mark 41 will not be replaced by the base mark. Plate W is covered. In contrast, regardless of the size of the substrate W, the four alignment mark holes 42h (at least one) of the mark forming means 42 are covered by the substrate W.

The surface of the cover plate 15P depicting the table 15 is schematically shown in FIG. 2, and a myriad of suction holes 15v are opened as is known in the art. These suction holes 15v are connected to the control device 18 and the suction connector 15c provided on the table body 15Q. Vac source 19.

With the drawing device 100 having the above structure, for example, the front and back surfaces of the substrate W are patterned in the following steps. As a pattern (for example, a circuit pattern) drawn on the front and back sides of the substrate W by the drawing device 100, for convenience (easy understanding), it is assumed that the letter "P" shown in FIG. 5 is drawn on the surface of the substrate W, and The outer frame F shown in FIG. 6 is depicted on the back. In addition, it is assumed that the table body 15Q and the cover plate 15P are fixed in a regular positional relationship in advance, and the table 15 is supported on the base 11 (rail 14) as a drawing.

Step 1: The substrate W is placed on the cover plate 15P of the drawing table 15. When the substrate W is placed on a conveying device (not shown), the substrate W is aligned in advance (determining the preliminary position), and therefore the approximate position of the substrate is determined at this point in time. When the operator places the substrate W by hand, the position is determined by an alignment standard provided on the cover plate 15P. Therefore, in order to respond to the setting by hand, a drawing tool for determining the position of the substrate may be provided on the drawing table 15 (the cover plate 15P or the table body 15Q). The tool for determining the position of the substrate is, for example, a line drawn on the cover plate 15P, or a position determining pin. The XY coordinate system on the substrate W is determined by the positions of the alignment marks (the positions of the four reference marks 41 and the four mark forming means 42 on the drawing table 15 taken by the alignment camera AC), so it is not necessary The substrate W is strictly matched with the cover plate 15P.

Second step: The substrate W placed on the cover plate 15P is vacuum-adsorbed by the suction hole 15v, the control device 18, and the vacuum source 19, and clamped by the substrate bead 17. After the substrate bead 17 is moved to a predetermined position, the substrate W is pressed onto the cover plate 15P.

Step 3: The drawing table 15 and the sliding part 13 are moved, and the image AC (dot mark) of the reference mark 41 at the four positions on the table 15 is shot with the camera AC (the alignment camera AC moves relative to each reference mark 41) . In other words, the red LED light emitted by the reference mark forming light source 41j is reflected by the reflecting element 41k and emitted from the reference mark hole 41h. The alignment camera AC recognizes the four reference marks 41 as the drawing table 15 moves in the X direction (No. Figure 5). The position information of the four fiducial marks 41 taken by the camera AC is transmitted to the position determining device, and the XY coordinate system is determined by drawing the fiducial marks 41 on the table 15.

Step 4: Either of the four alignment mark formation light sources 42j of the mark formation means 42 irradiates the back surface (second surface) of the substrate W with ultraviolet light to form a spontaneous color image (alignment mark) in the shape of the alignment mark hole 42h AM (Figure 6)). Which of the plurality of mark formation means 42 is used for irradiation is determined according to the substrate size (using a component list, etc.). Light sources 42j other than the selected mark forming means 42 do not emit light. An example of the irradiation time is about 10 seconds. In addition, this fourth step can be performed in parallel with other steps or before the third step is started.

Step 5: The position determining device determines an XY coordinate system based on the alignment mark AM on the back surface of the substrate from the XY coordinate system on the drawing table 15 based on the reference mark 41. Although an XY coordinate system based on the reference mark 41 can also be used, since the drawing is performed on the substrate W, the The XY coordinate system based on the alignment mark AM is preferred. Then, according to the formation position of the alignment mark AM on the back surface of the substrate, the pattern drawing position and the substrate position are matched with each other. This position can be implemented by correcting the drawing pattern data by the exposure drawing unit 30 to compensate the drawing position, or by moving the drawing table 15 in the XYθ direction. The θ direction is a rotation direction parallel to the Z direction as an axis. Such a position matching technique is widely known, and an appropriate method can be adopted as required.

Step 6: The surface (first surface) of the substrate W is drawn with a pattern (the example shown in the figure is the character L). The drawing knot of the pattern is performed by the relative movement of the exposure drawing unit 30 and the drawing table 15 (the substrate W). In the present embodiment, when the drawing table 15 is continuously moved in the X direction, the exposure drawing unit 30 continuously irradiates the substrate W with the drawing light. The drawing of the pattern can be performed by a well-known multiple exposure technique.

Step 7: The substrate W after the drawing of the pattern on the front surface (the first surface) is removed from the drawing table 15. The unloaded substrate W is turned over so that the back surface (second surface) faces upward. The unloading and turning operations are carried out by a conveying device (not shown), or by the operator's hand.

Step 8: The cover 15P of the table 15 is drawn to place the inverted substrate W (FIG. 6). The drawing table (drawing device) at this time may be the same device as in the first step, or may be a different drawing device. As in the first step, the substrate W is placed in a pre-aligned state.

Ninth step: As in the second step, the substrate W placed on the cover plate 15P is vacuum-adsorbed and clamped and fixed by the substrate bead 17.

Step 10: The alignment camera AC moves relative to the position of the alignment mark AM formed on the back surface (second surface) of the substrate W. The alignment mark AM is captured with the reflected illumination of the alignment camera AC, and the image is transmitted to the position determination. 定 装置 (Figure 6).

Step 11: The position determining device obtains the position of the alignment mark AM from the image sent from the alignment camera AC, and matches the pattern drawing position with the substrate position in the same manner as in the step 5 (FIG. 6). At this time, not only the positions are matched with each other, but also the shape of the drawing data can be corrected according to the expansion and contraction of the substrate. This is because an image such as a temperature change after the surface (the first surface) is exposed and drawn will cause the substrate to expand and contract. Therefore, an error in the drawing position due to such deformation is corrected.

Twelfth step: In the same manner as in the sixth step, a drawing (outer frame F) of the back surface (second surface) of the substrate W is drawn (FIG. 6).

Step 13: A step of moving the substrate W from which the image on the back surface (second surface) has been drawn from the drawing table 15 to the next stage.

In the above embodiment, plural (four) mark forming means 42 are provided for each reference mark 41, but one mark forming means 42 may be provided corresponding to each reference mark 41 in accordance with the planar size of the substrate W. When a plurality of mark formation means 42 are provided, they are arranged in a row in the above embodiment, but they are not necessarily arranged in a row. When the plurality of mark formation means 42 are arranged, alignment marks can be formed according to the size of the substrate. It only needs to be at a predetermined position relative to the fiducial mark.

The cover plate 15P may be replaced in accordance with the substrate W. In this way, more types of substrates and mark positions can be supported. In addition, the light sources of the reference mark 41 and the mark forming means 42 may not be LEDs, and the wavelength of the light may be appropriately selected according to the sensitivity of the photosensitive material applied or attached to the substrate. The reference mark 41 may be non-luminous (for example, printed matter) if the position can be determined by shooting with the alignment camera AC.

Claims (5)

A drawing device includes: a drawing table on which a substrate is placed; and an exposure drawing section that moves relative to the drawing table and draws a substrate on the drawing table, wherein the drawing table includes: a plurality of reference marks for setting A position reference with respect to the exposure drawing portion; and a plurality of mark forming means for forming an alignment mark on a back surface of the substrate placed on the drawing table, and located at a specific position with respect to each reference mark, wherein The drawing table includes a table body, a cover plate fixed to the table body so as to cover the table body, and the mark forming means is formed by at least one through hole penetrating through the cover plate and a mark fixed to the table body to form a light source. In the composition, the mark forming light source emits the mark forming light in a shape of the through hole from the through hole. The drawing device according to item 1 of the scope of patent application, wherein the fiducial mark has at least one through hole penetrating through the cover plate, and a visible light source fixed to the table body, wherein the visible light source emits visible light from the through hole. Take as a point mark. The drawing device according to item 2 of the scope of patent application, wherein the through-hole forming the mark forming means has a plurality of through-holes formed at predetermined intervals along a relative movement direction of the drawing table and the exposure drawing portion. The table body includes the mark-forming light source that emits the mark-forming light from the through-holes selected according to the substrate size from the plurality of through-holes. The drawing device according to item 3 of the scope of patent application, wherein the reference mark and the mark forming means are located on two opposite sides of the peripheral edge portion of the substrate placed on the drawing table, and each has a pair. The drawing device according to any one of claims 1 to 4, wherein the exposure drawing section has a shooting means for shooting the reference mark or the alignment mark, and the pattern drawing of the surface of the substrate is shot in accordance with the shooting method. The coordinate system set based on the position information of the fiducial mark is implemented. After the front and back sides of the substrate are reversed, the drawing of the pattern on the back of the substrate will be implemented by the coordinate system set according to the position information of the alignment mark captured by the photographing means.