KR102333949B1 - Lithography apparatus - Google Patents

Abstract

[Project] A drawing table on which a substrate is placed; In the drawing apparatus having a; an exposure drawing unit that moves relative to the drawing table and draws a pattern on a substrate on the drawing table, wherein the position error of the alignment mark formed on the substrate is small, and the planar precision of the substrate is not impaired. get the device [Solution means] A plurality of reference marks for setting a position reference for the exposure drawing unit on the drawing table, and a position for each reference mark that forms an alignment mark on the back surface of a substrate placed on the drawing table A drawing apparatus provided with a plurality of mark forming means identified by .

Description

Drawing device {LITHOGRAPHY APPARATUS}

TECHNICAL FIELD This invention relates to the drawing apparatus which draws a pattern on the front and back both surfaces of flat boards, such as an electronic circuit board, the glass board for LCD, and the glass board for PDP.

In recent years, a direct exposure apparatus (drawing apparatus) that draws a pattern by directly irradiating the front and back surfaces of the substrate with drawing light having a mutual positional relationship without using a transfer mask has emerged on the market in recent years. In this double-sided exposure, a plurality of alignment marks are exposed (formed) on the back surface (second surface) during pattern exposure (or prior to exposure) on the surface (first surface), and the front and back sides of the substrate are reversed. At the time of pattern exposure to two surfaces, the pattern exposure position is determined on the basis of the alignment mark formed in the 2nd surface (patent document 1, 2). Specifically, the alignment mark is an image (self-color development) using a circular pattern of less than φ2 mm, an index such as a cross, and the self-coloring property of a photoresist in the corner of the substrate to be exposed. As a general rule, it is provided optically.

Japanese Patent Laid-Open No. 2009-294337 Japanese Patent Laid-Open No. 2013-213852

However, the drawing apparatus of patent documents 1 and 2 is equipped with a movable mark forming means (alignment mark forming means, a mark exposure apparatus) with respect to the drawing table which mounts a board|substrate, and marks with respect to a drawing table (a board|substrate mounted on it). The forming means is moved, and the alignment mark is formed on the back surface of a board|substrate. For this reason, there is a possibility of including the positional error of an alignment mark by the unavoidable mechanical error of the movement mechanism which is a mark forming means. If there is an error in the formation position of the alignment mark, the drawing pattern on the second surface and the drawing pattern on the first surface do not match correctly. Moreover, when scaling correction, such as expansion/contraction of a drawing surface, is performed, correction|amendment different from the actual board|substrate expansion-contraction is performed.

Moreover, since the conventional apparatus must provide the position-adjustable mark forming means with respect to a drawing table, the enlargement of the whole apparatus cannot be avoided. Moreover, in patent document 2, in order to move a mark forming means, the avoidance part (groove part) of a mark forming means is provided in the drawing table surface.

For this reason, this avoidance part cannot support the back surface of a board|substrate, and may exert a bad influence on the drawing precision of a pattern (planar precision of a board|substrate).

Therefore, this invention has few position errors of the alignment mark formed in a board|substrate, and an object of this invention is to obtain the drawing apparatus which does not impair the plane precision of a board|substrate.

In the conventional drawing apparatus, in the drawing table on which the substrate is placed, the present invention specifies that the movable mark forming means is the cause of the error in the formation position of the alignment mark, and on the drawing table in the drawing table. It was made based on the idea that generation|occurrence|production of an error can be prevented by providing the formation means which forms an alignment mark directly on the back surface of the board|substrate mounted.

That is, the drawing apparatus of this invention includes the drawing table which mounts a board|substrate; An exposure drawing unit that moves relative to the drawing table and draws a pattern on a substrate on the drawing table, wherein the drawing table includes a plurality of reference marks for setting positional references with respect to the exposure drawing unit; , It is characterized in that a plurality of mark forming means for forming an alignment mark on the back surface of the substrate placed on the drawing table, the positions of which are identified with respect to each of the reference marks, are provided.

The drawing table includes, for example, a table body and a cover plate positioned on the table body, and the mark forming means includes at least one through hole drilled in the cover plate and the through hole. It can be comprised with the mark formation light source supported by the said table main body which radiate|emits the mark formation light from a ball.

A plurality of the through-holes forming the mark forming means may be drilled in the cover plate, and the table body may be provided with a mark forming light source for emitting a mark forming light to a through-hole selected from among the plurality of through-holes. can

Specifically, the reference mark and the mark forming means may be provided in pairs, each positioned on opposite two sides of the periphery of the substrate placed on the drawing table.

The said exposure drawing part can be equipped with the imaging means which images the said reference mark and an alignment mark. And, the drawing of the pattern on the surface of the substrate is performed by a coordinate system set based on the reference mark position information captured by the imaging means, It can be performed by the coordinate system set based on the alignment mark position information imaged by the said imaging means.

The reference mark is, in one embodiment, a spot mark from a visible light source.

In the present invention, since the drawing table on which the substrate is placed is provided with the mark forming means for forming the alignment marks on the back surface of the substrate, a mechanical error factor (such as a movement error of the mark forming means) does not occur in the alignment mark forming position. ADVANTAGE OF THE INVENTION According to this invention, it is a simple structure, and it can perform positioning of the pattern drawn on the front and back of a board|substrate with high precision. Moreover, the drawing table surface can be kept smooth and the board|substrate mounted can be adsorb|sucked and hold|maintained with high planarity uniformly to the peripheral part.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the whole structure of the drawing apparatus which concerns on this invention.
Fig. 2 is an exploded perspective view showing an embodiment of a drawing table of the drawing apparatus of Fig. 1 .
It is a top view of the same drawing table.
[FIG. 4] It is a cross-sectional view taken along line IV-IV of FIG.
It is a schematic plan view at the time of drawing on the surface (1st surface) of a board|substrate.
It is a schematic plan view at the time of drawing on the back surface (2nd surface) of a board|substrate.

1 : is a structural conceptual diagram of the whole drawing apparatus 100 of this invention. The drawing apparatus 100 is equipped with the base 11, the gate 12 erected from the both sides of the base 11, and the exposure drawing part 30 supported on this gate 12. As shown in FIG.

On the base 11, the drawing table 15 which mounts the board|substrate W which apply|coated the photosensitive material on the front and back is arrange|positioned. This drawing table 15 is movable along the rail 14 in the X direction by a linear motor moving means, for example. Hereinafter, a direction orthogonal to the X direction in a horizontal plane is set as a Y direction, and a direction orthogonal to the X direction in a vertical plane is made into a Z direction.

A slide 13 extending in the Y direction is provided on the front surface of the exposure drawing unit 30, and the slide 13 is provided with a pair of alignment cameras (imaging means) AC spaced apart in the Y direction. has been The slide 13 moves the alignment camera AC to an arbitrary position in the Y direction in linear motor driving or stepping motor driving.

The exposure drawing unit 30 includes a light source unit 20 . The light source unit 20 is composed of two light source units 20a and 20b having the same internal configuration. Since the light source unit 20a and the light source unit 20b have the same configuration, the light source unit 20a is representatively described.

The light source unit 20a includes a UV lamp 21 , a first total reflection mirror 22 , a condenser lens 23 , a second total reflection mirror 24 , and a fly-eye lens 25 . and an aperture (not shown). The light source part 20a is provided with the UV lamp 21, and the ultraviolet light in which various wavelengths from 365 nm to 440 nm are mixed is emitted from the UV lamp 21.

The ultraviolet light emitted from the UV lamp 21 is irradiated in the sky direction (+Z-axis direction) by the elliptical mirror 26, and is changed in the horizontal direction by the first total reflection mirror 22, and the condenser lens ( 23), and changes the direction to the ground direction (-Z-axis direction) in the second total reflection mirror 24 . The redirected ultraviolet light passes through the fly-eye lens 25 and the diaphragm and becomes a four-branched beam. The beam again becomes a controlled beam by passing through eight first projection lenses 33 and eight reflecting mirrors 34 and incident on eight DMD (Digital Micro-mirror Device) elements 36 . This controlled beam passes through the 2nd projection lens group 37, adjusts the magnification of the exposure drawing to project, and is irradiated to the board|substrate W. As shown in FIG. That is, the drawing apparatus 100 controls the ultraviolet light of the light source part 20a and the light source part 20b according to the drawing data in which the desired exposure image is previously accommodated.

The drawing table 15 is equipped with the table main body (lower table) 15Q, and the cover plate 15P on the table main body 15Q. 2 to 4 show details of the drawing table 15 . The drawing table 15 has comprised the rectangular parallelepiped shape whose outer surface extended in the orthogonal triplanar direction of XYZ. The table main body 15Q and the cover plate 15P have the same dimension in the X direction and the Y direction, and the cover plate 15P has a smaller thickness in the Z direction than the table main body 15Q. The table main body 15Q and the cover plate 15P can be disassembled as schematically shown in FIG. 2 , for example, fixed at a regular position by a positioning device and an adsorption device (not shown) to attach the drawing table 15 to the drawing table 15 . to configure (Fig. 1, Fig. 3, Fig. 4).

Each of the four corners of the board|substrate mounting surface of the rectangular drawing table 15 is provided with the one reference mark 41, and the mark forming means 42 which forms the alignment mark corresponding to each reference mark 41, respectively. That is, on the drawing table 15, the some reference mark 41 and the some mark formation means 42 corresponding to each reference mark 41 are provided.

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 main body 15Q. The mark forming means 42 includes a plurality of (four in the illustrated embodiment) alignment mark holes (through holes) 42h formed in the cover plate 15P, and each alignment mark hole 42h in the table main body 15Q. ) is formed by the four alignment mark formation light sources 42j supported in correspondence with each other. The reference mark forming light source 41j is made 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 (alignment camera AC direction). The alignment mark forming light source 42j is made of an ultraviolet LED, and is emitted directly 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 on the circuit board 43 (FIG. 4), and the circuit board 43 and the reflective element 41k are the table body 15Q. ) is excreted in the recessed part 15r formed in it.

One reference mark hole 41h (reference mark formation light source 41j) and four alignment mark holes 42h (alignment mark formation light source 42j) are the same alignment cameras mounted in the exposure drawing unit 30 . In order to facilitate imaging by (AC), it is formed by aligning it in a line in the X direction. As shown in Figs. 3 and 4, in the illustrated example, the spacing of the alignment mark holes 42h of the mark forming means 42 is the same, and the reference mark 41 is, with respect to this mark forming means 42, It is spaced apart more than the space|interval of alignment mark hole 42h comrades.

The positional relationship between the one reference mark 41 and the four mark forming means 42 is fixed on the drawing table 15, and the mutual positional relationship (coordinate system on the XY plane) can be recognized strictly (recognition). becoming). For this reason, the alignment camera AC image|photographs the mark forming means 42 (reference mark 41), and calculating|requiring the position of a mark is the alignment mark formed by the reference mark 41 (mark forming means 42). ) is the same as finding the position of

Moreover, the reference mark 41 of the four corners on the drawing table 15 is arrange|positioned so that it may be located outside the mark formation means 42, and between the reference mark 41 and the mark formation means 42, the board|substrate A press (17) is located. The board|substrate presser 17 supports the edge part (the both-side edge part of X direction) of the board|substrate W mounted on the drawing table 15, and it folds at least with respect to the drawing table 15 surface. It is movable in the direction (Z direction).

Since there are various plane sizes of the board|substrate W mounted on the drawing table 15, it is preferable that the board|substrate press 17 is movable also in the X direction. However, the substrate W does not protrude beyond the substrate press 17 in 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 is not blocked by the substrate W . On the other hand, regardless of the size of the substrate W, the four alignment mark holes 42h (at least one of) of the mark forming means 42 are blocked by the substrate W. As shown in FIG.

On the surface of the cover plate 15P of the drawing table 15, as schematically shown in FIG. 2, innumerable well-known suction holes 15v are opened, and these suction holes 15v are formed in the table body 15Q. It is connected to the control device 18 and the vacuum source 19 via the provided suction connector 15c.

The drawing apparatus 100 of the said structure draws the pattern with respect to the front and back surface of the board|substrate W in the following steps, for example. As a pattern (for example, a circuit pattern) drawn by the drawing apparatus 100 on the front and back sides of the substrate W, for convenience (for ease of understanding), the "P" shown in FIG. It is assumed that the letter L of " is drawn, and the frame F shown in FIG. 6 is drawn on the back surface. In addition, it is assumed that the table main body 15Q and the cover plate 15P are fixed in a regular positional relationship beforehand, and are supported as the drawing table 15 on the base 11 (rail 14).

Step 1

The substrate W is mounted on the cover plate 15P of the drawing table 15 . When the board|substrate W is mounted by the conveyance apparatus (not shown), since the board|substrate W previously pre-aligned (preliminary positioning) is mounted, the board|substrate is roughly positioned at this point in time. When an operator places the board|substrate W by hand, the position is determined by the reference|standard provided in the cover plate 15P. You may provide the jig for board|substrate positioning in the drawing table 15 (cover plate 15P or table main body 15Q) in preparation for the case where it installs by hand. As the jig for positioning the substrate, for example, a line written on the cover plate 15P, a positioning pin, or the like is used. The XY coordinate system with respect to the board|substrate W is the alignment formed by the position of the reference mark 41 of 4 places on the drawing table 15 imaged by the alignment camera AC, and the mark forming means 42 of 4 places. Since it is determined by the position of the mark, strict alignment of the substrate W on the cover plate 15P is unnecessary.

2nd step

The substrate W placed on the cover plate 15P is vacuum-sucked by the suction hole 15v, the control device 18, and the vacuum source 19, and is clamped by the substrate presser 17. The substrate press 17 moves to the position indicated in advance, and presses the substrate W against the cover plate 15P.

Step 3

Drawing table 15 and slide 13 move, and alignment camera AC images images (spot marks) of four reference marks 41 on drawing table 15 (alignment camera AC) relative to each reference mark 41). That is, the light of the red LED from the reference mark formation light source 41j is reflected by the reflective element 41k and exits from the reference mark hole 41h, and the alignment camera AC moves the drawing table 15 in the X direction. As a result, four reference marks 41 are recognized (FIG. 5). The positional information of the four reference marks 41 which alignment camera AC imaged is transmitted to a positioning apparatus, and the XY coordinate system by the reference mark 41 on the drawing table 15 is determined.

4th step

Any one of the four alignment mark forming light sources 42j of the mark forming means 42 irradiates ultraviolet light to the back surface (second surface) of the substrate W, and self-color development in the form of the alignment mark hole 42h (alignment mark AM (FIG. 6)) is formed. Which of the plurality of mark forming means 42 is used to perform irradiation is determined in advance by the size of the substrate (using a recipe or the like). The light sources 42j other than the selected mark forming means 42 are not lit. The irradiation time is about 10 seconds in one example. In addition, this 4th step can be implemented in parallel with another step, and may be implemented before the start of a 3rd step.

5th step

The positioning apparatus determines the XY coordinate system based on the alignment mark AM on the back surface of a board|substrate from the XY coordinate system on the drawing table 15 based on the reference mark 41. As shown in FIG. Although it is also possible to use the XY coordinate system by the reference mark 41, since drawing is performed on the board|substrate W, it is preferable to use the XY coordinate system by the alignment mark AM on the board|substrate W. And the pattern writing position and the board|substrate position are relatively aligned according to the formation position of the alignment mark AM on the back surface of this board|substrate. This relative alignment can be performed by the exposure drawing unit 30 correcting the drawing pattern data to offset the drawing position, or moving the drawing table 15 in the XYθ direction. The θ direction is a rotation direction in a direction parallel to the Z direction.

Such a relative positioning technique is well known, and an appropriate method may be employed as needed.

Step 6

A pattern (character L in the example of illustration) is drawn on the surface (first surface) of the board|substrate W. As shown in FIG. Drawing of a pattern is performed by the relative movement of the exposure drawing part 30 and the drawing table 15 (substrate W). In this embodiment, when the drawing table 15 moves continuously in the X direction, the exposure drawing part 30 irradiates drawing light to the board|substrate W continuously. Drawing of a pattern is performed by well-known multiple exposure technique.

7th step

The board|substrate W which pattern writing of the surface (1st surface) completed is carried out from the drawing table 15 top. The carried out board|substrate W is inverted, and the back surface (2nd surface) becomes the top. Carrying out and reversing operations are performed by a conveying device (not shown), or a worker performs manually.

Step 8

The inverted board|substrate W is mounted on the cover plate 15P of the drawing table 15 (FIG. 6). In addition, the drawing table (drawing apparatus) at this time may be the same apparatus as 1st step, or another drawing apparatus may be sufficient as it. Like the first step, the substrate W is placed in a pre-aligned state.

Step 9

As in the second step, the substrate W placed on the cover plate 15P is vacuum-sucked and clamped and fixed by the substrate press 17 .

Step 10

The alignment camera AC moves relatively to the position of the alignment mark AM formed on the back surface (second surface) of the substrate W. Alignment mark AM is imaged by the reflected illumination with which alignment camera AC was equipped, and an image is transmitted to a positioning device (FIG. 6).

Step 11

A positioning apparatus calculates|requires the position of alignment mark AM from the image from alignment camera AC, and aligns a pattern drawing position and a board|substrate position relatively like a 4th step (FIG. 6). Moreover, at this time, you may correct|amend the shape of drawing data corresponding to not only a relative alignment but a board|substrate expansion-contraction. This is performed in order to correct the error of the pattern writing position by the deformation|transformation, since the board|substrate may expand-contract under the influence of temperature change etc. after exposure writing to the surface (1st surface).

Step 12

Like the 6th step, drawing of a pattern (frame F) is performed on the back surface (2nd surface) of the board|substrate W (FIG. 6).

Step 13

The board|substrate W which pattern writing of the back surface (2nd surface) completed is carried out from the drawing table 15 top, and it is conveyed by the following process.

In the above embodiment, although the plurality (four) mark forming means 42 is provided with respect to one reference mark 41, depending on the planar size of the board|substrate W, depending on the plane size of the board|substrate W, one reference mark 41 One mark forming means 42 may be made to correspond to . In the case of providing a plurality of mark forming means 42, although they are arranged in a row in the above embodiment, it is not necessary to arrange in one row, and an alignment mark can be formed at a position determined with respect to the reference mark according to the size of the substrate. What is necessary is just to arrange a plurality of mark forming means 42 so as to

Moreover, you may make it replace|exchange the cover plate 15P according to the board|substrate W. By doing so, it is possible to cope with various types of substrates and marking positions.

In addition, the light source of the reference mark 41 and the mark forming means 42 may not be LED, and the wavelength of the light is suitable for the wavelength at which self-color development is sufficiently formed depending on the sensitivity of the photosensitive material applied or pasted to the substrate. to be chosen

The reference mark 41 may be non-luminous (for example, printed matter) as long as it is imaged by the alignment camera AC and the position is specified.

100 drawing device
11 bass
15 drawing table
15c suction connector
15r main part
15v suction hole
15P cover plate
15Q table body
17 Press the board
18 control
19 vacuum source
20 light source
30 exposure drawing department
41 reference mark
41h standard markhole
41j fiducial mark forming light source
41k reflective element
42 Mark forming means
42h alignment mark hole
42j alignment mark forming light source
43 circuit board
AC alignment camera (imaging means)
AM alignment mark
W board

Claims (6)

a drawing table on which a substrate is placed; An exposure drawing unit that moves relative to the drawing table and draws a pattern on a substrate on the drawing table;
A plurality of reference marks for setting a position reference with respect to the exposure drawing unit on the drawing table, and a plurality of positions for each of the reference marks that form an alignment mark on the back surface of a substrate placed on the drawing table are specified provide a means for forming a mark of
The drawing table has a table body and a cover plate positioned on the table body,
The said mark forming means consists of at least one through-hole drilled in the said cover plate, and the mark forming light source supported by the said table body which radiates the mark forming light from the said through-hole, The writing apparatus characterized by the above-mentioned . According to claim 1,
A plurality of the through-holes forming the mark forming means are perforated in the cover plate, and the table body is provided with a mark forming light source for emitting a mark forming light to a through hole selected from among the plurality of through-holes. Device. 3. The method of claim 1 or 2,
A writing apparatus in which the reference mark and the mark forming means are positioned on two opposing sides of the periphery of the substrate placed on the writing table, and a pair of each is provided. 3. The method of claim 1 or 2,
The exposure drawing unit has imaging means for imaging the reference mark or the alignment mark, and the drawing of the pattern on the surface of the substrate is performed by a coordinate system set based on the reference mark position information imaged by the imaging means, the Drawing of a pattern with respect to the back surface of a board|substrate by reversing the front and back of a board|substrate is a drawing apparatus performed by the coordinate system set based on the alignment mark position information imaged by the said imaging means. 3. The method of claim 1 or 2,
The reference mark is a spot mark from a visible light source. delete

Images