TW202205023A - Exposure device which exposes a pattern to a substrate without limitation of distance by a belt conveyor - Google Patents

Abstract

An object of this invention is to ensure linearity of a relative movement between a substrate and an exposure unit and to reduce an error of exposure. The solution is an exposure device that comprises: a conveyor belt for conveying a substrate; an adsorption means for bringing the substrate into hermetic contact with an upper surface of the conveyor belt; an exposure unit for exposing the substrate; and a guide part for suppressing displacement of the conveyor belt in a direction orthogonal to a conveyance direction.

Description

Exposure device

The present invention relates to an exposure apparatus which can be applied to a direct exposure apparatus used in an exposure step of a substrate such as a PCB or an LCD panel.

A direct exposure apparatus (maskless exposure apparatus) that does not use a mask is known in the photolithography step of manufacturing substrates such as printed circuit boards, semiconductor wafers, LCD glass substrates, and the like. According to this direct exposure method, since a mask is not required, it is advantageous in terms of cost, and it is possible to perform high-precision exposure. In a direct exposure apparatus, exposure is performed while the substrate and the exposure unit are relatively moved, so that exposure in a wider range than the projected image of a light modulation element (DMD (Digital Micro-mirror Device), etc.) is possible. .

As for the relative moving means, the structure in which the exposure stage holding the long substrate is linearly moved using a linear motion guide is general, and the pattern exposure is performed in a range wider (longer in the conveying direction) than the exposure stage. It is performed by connecting patterns in a narrow range (for example, refer to Patent Document 1). Moreover, as an exposure apparatus which can continuously expose a pattern in a wide range, the direct exposure apparatus which conveys a long board|substrate by a belt conveyor is proposed (for example, refer patent document 2). [Preceding Patent Documents] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2016-224301 [Patent Document 2] Japanese Patent Laid-Open No. 2006-098720

[The problem to be solved by the invention]

In the exposure apparatus described in Patent Document 1, positional deviation is likely to occur at the part where patterns are connected, and furthermore, a waiting time occurs due to the reciprocating movement of the exposure stage, and the throughput decreases. On the other hand, in the exposure apparatus of Patent Document 2, the amount of meandering of the tie belt directly appears as an error in the position or shape of the pattern. This amount of error occurs at the exposure position because there is an irregular meandering of about 50 μm in the movement of the substrate by the belt conveyor.

Therefore, an object of the present invention is to provide an exposure apparatus which can perform pattern exposure on a substrate without limitation of distance by a belt conveyor, and can ensure the linearity of relative movement between the substrate and the exposure section. [Means of Solving Problems]

The present invention relates to an exposure device comprising: a conveyor belt for conveying a substrate; an adsorption means for closely contacting the substrate with the upper surface of the conveyor belt; an exposure unit for exposing the substrate; and a guide part for restraining the conveyor belt The displacement of the belt in the direction orthogonal to the conveying direction. Furthermore, the present invention relates to an exposure apparatus comprising: a conveyor belt for conveying the substrate; an adsorption means for closely contacting the substrate with the upper surface of the conveyor belt; an exposure unit for exposing the substrate; The vicinity of at least one side surface of the conveyor belt is engaged; and the guide portion is provided in the vicinity of one side surface of the conveyor belt and guides the slider along the shape formed by the one side surface of the conveyor belt. [Effect of invention]

According to at least one embodiment of this invention, the linearity of the relative movement of the board|substrate and exposure part at the time of conveyance by a belt conveyor can be ensured. In addition, the effects described here are not necessarily limited, and may be any of the effects described in the present invention. In addition, it should not be construed that the content of the present invention is limited by the effect shown by way of example.

Hereinafter, embodiments and the like of the present invention will be described with reference to the drawings. In addition, the embodiments and the like described below are suitable specific examples of the present invention, and the content of the present invention is not limited to these embodiments and the like.

As shown in FIG. 1 , a direct exposure apparatus 1 according to an embodiment of the present invention is composed of an exposure unit 10 serving as an exposure means and a belt conveyor unit 20 for conveying a belt which is a flexible recording medium. A long substrate (such as a flexible printed circuit wiring board) W. One embodiment is a roll-to-roll exposure device.

The elongated substrate W is a sheet-like substrate such as a copper foil substrate coated with a photosensitive material such as a photoresist, and has a length of several tens to several hundreds of meters. It becomes, for example, a base material of a flexible printed wiring board by a process such as development, etching, and cutting after exposure. The moving direction (conveying direction M) of the elongated substrate W is defined as the X direction, the direction (thickness direction) perpendicular to the elongated substrate W is defined as the Z direction, and the directions perpendicular to the X and Z directions are defined for the Y direction.

The exposure unit 10 includes a plurality of exposure heads 11 , and is regularly arranged at positions separated from the elongated substrate W by a predetermined distance vertically upward. For each exposure head, a light source and an illumination optical system are arranged, and light emitted from the light source is guided to the corresponding exposure head 11 via the corresponding illumination optical system, respectively. Each exposure head includes: DMD (Digital Micro-mirror Device), which arranges a plurality of micro-mirrors two-dimensionally; and an imaging optical system, which makes the image of the DMD image on the long substrate.

The belt conveyor unit 20 is provided for conveying the long substrate W in the direction M from the left to the right when viewed in the drawing. The conveyor belt 21 is a metal belt having an air-permeable structure, and is, for example, a mesh-shaped stainless steel belt in which a plurality of fine through holes are formed. In addition, it is preferable that the conveyor belt 21 is a metal belt (stainless steel belt) which is difficult to stretch and has a low dust emission property.

The long substrate W is placed on the upper surface of the conveyor belt 21 , and the long substrate W is brought into close contact with the conveyor belt 21 by the substrate suction table 23 shown by the broken line. That is, suction is sucked through the through holes of the conveyor belt 21 by the substrate suction stage 23 , and the long substrate W is in close contact with the upper surface of the conveyor belt 21 . The conveyor belt 21 is an endless belt wound between the conveyor belt drive roller 22a and the conveyor belt drive roller 22b.

The long substrate W is supplied from the substrate unwinding unit 30 to the belt conveyor unit 20 , and is wound from the belt conveyor unit 20 by the substrate winding unit 40 after exposure. The substrate unwinding section 30 includes: a substrate unwinding roller 31 for winding the unexposed long substrate W; a tension roller 32 which functions as a buffer; and rollers 33a and 33b for correcting the meandering of the substrate mechanism. The substrate winding unit 40 includes: a substrate winding roller 41 for winding the long substrate W after exposure treatment; and a tension roller 42 serving as a substrate buffer. Since these tension rollers 32 and 42 function as tension setting means, the long substrate W is stably conveyed on the conveyor belt 21 on the conveyance path without slack.

Furthermore, the camera 50 for alignment is arrange|positioned on the upstream side of the exposure unit 10, and the calibration scale unit 51 is arrange|positioned in the board|substrate winding part 40. The alignment camera 50 detects the ends or marks of the elongated substrate W, detects the relative positional deviation between the elongated substrate W and the exposure unit 10 , and corrects the exposure processing by the exposure unit 10 . The calibration scale unit 51 is provided so that the exposure amount becomes an appropriate value. The long substrate W is supported by a plurality of support rollers, but is supported by the belt conveyor 20 in the vicinity of the alignment camera 50 and the exposure head 11 .

In this way, the elongated substrate W is maintained in a state of being attracted by the conveyor belt 21, and is continuously conveyed in a fixed conveying direction. Since the exposure process can be performed while continuously driving the conveyor belt 21, the exposure process can always be continuously performed, and the throughput can be improved. In addition, since the long substrate W is in close contact with the conveyor belt 21 with high flatness, the relative positional relationship between the exposure unit 10 and the exposure head can be kept constant.

FIG. 2 is a plan view of the belt conveyor unit 20 viewed from above. In addition, the exposure head 11 and the camera 50 for alignment do not belong to the constituent elements of the belt conveyor unit 20, but are described for reference. In addition, in FIG. 1, the frame 24 fixed to the annular guide rail 25 is abbreviate|omitted.

The conveyor belt drive motors DMa and DMb rotate the conveyor belt drive rollers 22a and 22b to move (rotate) the conveyor belt 21 . The movement amount of the conveyor belt 21 can be calculated by detecting the rotation amounts of the conveyor belt drive motors DMa and DMb. The movement amount of the conveyor belt 21 is used as relative position information when the exposure unit 10 controls the DMD.

Even a belt conveyor with an edge position controller (EPC) generally has an irregular belt meandering of about 50 μm in the Y direction (axial direction of the conveyor belt 21 ). On the other hand, in the direct exposure apparatus, the exposure position accuracy is ±5 μm or less, and the line width variation is ±1 μm or less, for example, as allowable errors. Therefore, in order to prevent the reduction of the exposure position accuracy and the line width accuracy, a guide mechanism for ensuring the linearity of the movement of the conveyor belt 21 is required.

In one embodiment of the present invention, a frame 24 is installed near one side of the conveyor belt 21 , and an endless guide rail 25 in the shape of a track of the conveyor belt 21 is attached to the frame 24 . That is, the annular guide 25 is formed in the same or similar shape as the annular shape forming one side surface of the conveyor belt 21 . A metal guide S as a guide portion is slidably attached to the annular guide rail 25 . The plurality of guides S are attached so as to use a metal annular guide 25 as a shaft via a linear motion bearing such as a ball bearing.

The portion near the side surface of the conveyor belt 21 outside the region where the elongated substrate W is placed is joined to the slider S by the belt joint C which is the joint portion. The belt engaging member C may be integrally constructed with the sliding member S, or may be different components. Therefore, the displacement (meandering) of the conveyor belt 21 in the Y direction is restricted, and on the other hand, the conveyor belt 21 is freely movable in the X direction (and the Z direction) along the endless guide rail 25 .

The belt engaging member C has a protruding portion protruding from the slider S, and the conveyor belt 21 and the slider S are engaged by engaging (locking) the protruding portion with the ventilation opening provided in the conveyor belt 21 . With such a structure, it is easy to release the engagement state of the conveyor belt 21 and the guide S, and the replacement work accompanying the wear of the conveyor belt 21 becomes easy. In addition, instead of fitting, the conveyor belt 21 and the guide slider S can be joined by adhesion or welding, locking with bolts, or the like.

The annular guide 25 is at least in the section D in FIG. 1 (between the conveyor drive rollers 22a and 22b, the section where the long substrate W is in close contact with the upper surface of the conveyor belt 21), and serves as a bearing for the guide S The structure is preloaded to make the conveyor belt move linearly with high precision. Outside the range of D, it is only necessary to hold the guide S so as not to fall off the annular guide rail 25, and it is not necessary to apply a preload.

According to the above-described one embodiment of the present invention, the linearity of the relative movement between the elongated substrate W and the exposure head 11 can be ensured in the section (D) in which the elongated substrate W and the upper surface of the conveyor belt 21 are in close contact with each other. The error during exposure is small. In addition, annular guide rails may be provided in the vicinity of both side surfaces of the conveyor belt 21 to guide both ends of the conveyor belt 21 .

The exposure apparatus of the present invention can perform pattern exposure of unlimited length. The unrestricted length is a length that is not limited by other than the length of the supplied substrate, for example, an exposure device draws a pattern at a length of 6 m. At that time, the exposure apparatus performed the exposure operation according to the following procedure.

Step 1: The alignment camera 50 detects the end portion or the mark of the elongated substrate W, and detects the relative positional deviation amount of the elongated substrate W and the exposure unit 10 . The detection of the substrate end or mark may be performed while the long substrate W is stationary, or the conveyor belt 21 may be looped and the long substrate W may be moved in the conveyance direction M while being detected.

Step 2: Correct the drawing coordinates according to the relative positional deviation between the substrate W and the exposure unit 10 . At the same time, the calibration of the drawing pattern is performed with the substrate.

Step 3: While operating the substrate suction table 23, the conveyor belt 21 is revolved to move the long substrate W in the conveying direction M, and the drawing pattern data is transferred to the DMD of the exposure unit 10 according to the movement of the conveyor belt 21, and make changes in turn. The light from the light source of the exposure unit 10 is modulated by the DMD, and projected from the output end of the exposure head 11 to the elongated substrate W, thereby patterning exposure of the photoresist of the elongated substrate W. Since the long substrate is moved by the loop of the conveyor belt 21, pattern exposure of unlimited length can be performed.

In order to ensure the processing time of the drawing data, the pattern exposure action of unlimited length can also be paused in the middle. In addition, during the pattern exposure of unlimited length, the alignment camera 50 may confirm the positions of a plurality of marks provided in the middle. Alternatively, the alignment camera 50 during exposure may always confirm the position of the substrate end surface.

As mentioned above, although embodiment of this invention was demonstrated concretely, it is not limited to each embodiment mentioned above, Various deformation|transformation is possible based on the technical idea of this invention. In addition, the deformed form can be appropriately combined with one or a plurality of arbitrarily selected ones. In addition, the configurations, methods, steps, shapes, materials, numerical values, etc. of the above-described embodiments can be combined with each other as long as they do not depart from the gist of the present invention.

For example, the present invention can also be applied to an exposure apparatus using a mask. Moreover, this invention is not limited to the structure which exposes a long board|substrate, The board|substrate cut|disconnected into a rectangle (panel shape) can also be mounted on a conveyor belt and exposed like a long board|substrate. In this case, instead of the substrate unwinding unit 30 and the substrate winding unit 40 , conveying means such as a substrate transfer machine (handler) and a Selective Compliance Assembly Robot Arm are provided. Furthermore, in the above-described one embodiment, the tie belt belt 21 is an endless belt, and the endless guide rail 25 is formed in an endless shape, but one or both of these may be of a roll-to-roll system.

W: strip substrate 10: Exposure unit 20: Belt conveyor unit 21: Conveyor belt 23: Substrate adsorption table 25: Ring guide S: guide slide C: Belt joint

[FIG. 1] FIG. 1 is a front view showing the overall schematic configuration of an embodiment of the present invention. [Fig. 2] Fig. 2 is an enlarged plan view of a part of an embodiment of the present invention.

10: Exposure unit

11: Exposure head

20: Belt conveyor unit

21: Conveyor belt

22a: Conveyor belt drive roller

22b: Conveyor belt drive roller

23: Substrate adsorption table

25: Ring guide

30: Substrate unwinding part

31: Substrate unwinding roller

32: Tension roller

33a, 33b: Roller

40: Substrate winding section

41: substrate winding roller

42: Tension roller

50: Align the camera

51: Calibration scale unit

C: Belt joint

M: conveying direction

S: guide slide

W: strip substrate

Claims (8)

An exposure device comprising: The conveyor belt is used to transport the substrate; The adsorption means is to make the base plate closely contact the upper surface of the conveyor belt; an exposure unit for exposing the substrate; and The guide portion suppresses the displacement of the conveyor belt in the direction orthogonal to the conveying direction. The exposure device of claim 1, wherein the guide part is arranged near at least one side of the conveyor belt; A guide that is engaged with the vicinity of one side surface of the conveyor belt is slidably attached to the guide portion. The exposure apparatus of claim 1, wherein the substrate is an elongated substrate. The exposure apparatus of claim 1, wherein the conveyor belt is an endless belt wound between a plurality of rollers. The exposure apparatus of claim 4, wherein the guide portion is formed to be substantially the same as the shape of a side surface of the endless belt forming a loop. The exposure apparatus of claim 1, wherein the suction means is configured to suction the substrate through a plurality of through holes formed in the conveyor belt, and the protrusions of the guide slide are locked in the through holes. The exposure apparatus of claim 1, wherein the guide is attached to the guide portion via a bearing, and a preload is applied to the bearing in a section where the substrate is brought into close contact with the conveyor belt. An exposure device comprising: The conveyor belt is used to transport the substrate; The adsorption means is to make the base plate closely contact the upper surface of the conveyor belt; an exposure unit for exposing the substrate; a guide that is engaged adjacent at least one side of the conveyor belt; and The guide portion is arranged near one side surface of the conveyor belt, and guides the guide member along the shape formed by the one side surface of the conveyor belt.

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