JP2006330192A - Method and device for marking alignment mark - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for marking an alignment mark for easily obtaining an excellent mark form without contaminating the surface of a glass substrate or inducing decrease in strength of the glass substrate or cracks caused by marking. <P>SOLUTION: When an alignment mark for positioning is marked on a glass substrate 2 before a step of forming a pattern on the glass substrate 2, an alignment mark is marked on the glass substrate 2 by use of a thermal printer 9. In the pattern forming step, the glass substrate 2 is preferably subjected to split exposure using a plurality of photomasks corresponding to a plurality of surface regions on the glass substrate 2. The alignment mark is a cross the center of which is punched as a positioning reference. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for marking an alignment mark on a glass substrate, and more particularly to a technique for marking an alignment mark for positioning on a glass substrate before pattern formation.

  As is well known, when manufacturing glass panels for various image display devices such as plasma displays, liquid crystal displays, electroluminescence displays, and field emission displays, multiple glass panels are produced from a single glass substrate (raw glass). Has been adopted.

  In the manufacturing process of an image display device represented by this type of flat panel display, for example, there is a process of forming a transparent conductive film on the glass substrate and producing a micro wiring pattern of micron order from the film by a photo process. Executed. When performing this process, the positioning of the glass substrate and the photomask has a significant effect on the quality of the pattern. In fact, there are many processes that require the maintenance of positioning accuracy in these processes.

  Therefore, an alignment mark for positioning is formed on this type of glass substrate, and the alignment between the glass substrate and the photomask is performed with an accuracy of several tens of microns or several microns with reference to the alignment mark. Yes. As a method of forming this alignment mark, according to the following Patent Document 1, a method of forming an alignment mark on a substrate from a resist layer by a photo process is disclosed. This method consists of (1) processing to form a resist layer over a wide range on the substrate, (2) processing to dry the resist layer, (3) processing to cover the resist layer on the mask, and (4) exposure. A total of five stages of processing, (5) development processing, are required.

  In the column of [Prior Art] of the same document, a method for marking identification information on a substrate using a laser marker is described. Further, according to the following Patent Document 2, a method of forming an alignment mark by applying light non-transparent ink on a substrate from an inkjet head and irradiating the laser beam to sublimate or scatter the light non-transparent ink. Is disclosed.

JP 2003-140366 A JP 2003-248207 A

  Incidentally, as disclosed in the above-mentioned Patent Document 1, according to the method of forming an alignment mark on a substrate from a resist layer, it is necessary to perform a large number of processes (processes in five stages). The work for forming the mark becomes troublesome and complicated, resulting in a deterioration in work efficiency. In addition, in this method, the surface of the substrate is contaminated due to the alignment mark forming operation, and there is a possibility that the processing in each process including the subsequent pattern formation may be hindered. Depending on the contents, the resist layer disappears, and there is a concern that it cannot serve as an alignment mark.

  In addition, when the alignment mark is engraved on the substrate using a laser marker in consideration of the description of the document, the surface of the substrate is contaminated or scratched by fine powder generated at the time of engraving. Problems arise. In particular, when the substrate is a glass substrate, an alignment mark is imprinted on the surface or inside of the substrate, thereby generating distortion, reducing the strength of the imprinted portion, and generating cracks from the imprinted portion. May be adversely affected in the next process.

  Further, as disclosed in Patent Document 2 described above, according to the technique of forming an alignment mark by adopting an ink jet method, a droplet is ejected from a small diameter nozzle of the ink jet head, and the alignment mark is made of a droplet. Since it is drawn as a set of points, there is a problem that the fineness of the mark shape is inferior. More specifically, the droplets ejected onto the surface of the glass substrate by the ink jet method have an unreasonably different spread depending on the surface properties such as water repellency and dirt on the surface of the glass substrate. Complicated and difficult control is unavoidable in order to accurately control the discharge position to achieve a mark shape that meets the requirements.

  In recent years, with the increase in the size of the flat panel display and the increase in the number of glass panels taken from a single glass substrate, it has been promoted to increase the size of the glass substrate. Under such circumstances, in order to form a pattern on a substrate by batch exposure using one photomask, an extremely large photomask is required. In that case, it is difficult to maintain the accuracy of the large-sized photomask itself, and even if the accuracy is maintained well, not only is it difficult to hold the photomask in the exposure apparatus, but also depending on the temperature. Due to the need for expansion correction, it becomes difficult to maintain accuracy in the actual process as the size increases. Moreover, the production of such a large photomask becomes even more difficult even in view of the material of the member to be used, and a pattern is formed by batch exposure on a recent large-sized glass substrate. It is understood that this is practically impossible.

  Therefore, in recent years, it has been proposed that a small (or medium-sized) photomask is provided in each of a plurality of surface regions of a large glass substrate, and a pattern is formed by divided exposure. However, in such a method of forming a pattern by divided exposure using a plurality of photomasks, in order to prevent the continuity of the pattern from being disturbed between the plurality of photomasks, on the glass substrate of each photomask Therefore, it is necessary to make the positioning at the position very accurate. From such a viewpoint, it is significant to appropriately form the above-mentioned alignment mark on the glass substrate.

  The present invention has been made in view of the above circumstances, does not contaminate the surface of the glass substrate, does not cause a decrease in strength of the glass substrate due to engraving, cracking, etc., and easily has a good mark shape It is a technical problem to provide an alignment mark marking method capable of obtaining the above.

  The alignment mark marking method according to the present invention, which has been created to solve the above technical problem, marks a positioning alignment mark on a glass substrate before executing a step of forming a pattern on the glass substrate. In the method, the alignment mark is imprinted on a glass substrate using a thermal printer.

  According to such a method, since the alignment mark is engraved on the glass substrate using a thermal printer, the alignment mark is formed on the glass substrate only by pressing the print head of the thermal printer against the glass substrate. The heat transfer is properly performed. As a result, increase in the number of processing, deterioration of work efficiency, contamination of the glass substrate, etc. as in the case of the photo process using the conventional resist are avoided, and the adverse effects and engraved portions due to fine powder as in the case of the laser marker are avoided. In addition, it is possible to avoid the occurrence of cracks and the like, and to make it difficult to control the droplet diameter and discharge position, as well as to maintain the proper surface properties of the glass substrate and to improve the mark shape. Maintenance difficulty is avoided. The alignment mark material, i.e., the ribbon of the thermal printer, may be made of metal (e.g., gold, silver, copper, aluminum), or may be made of resin (e.g., polyimide). It may be a thing. Accordingly, when it is desired to change the material of the alignment mark in accordance with the processing content of the next process, only the ribbon of the thermal printer needs to be replaced.

  In this case, in the step of forming the pattern, it is preferable to perform divided exposure using a plurality of photomasks corresponding to a plurality of surface regions on the glass substrate.

  In this way, when the glass substrate is a large plate (for example, the vertical dimension is 800 mm to 1200 mm and the horizontal dimension is 800 mm to 1200 mm), a plurality of the above-mentioned alignment marks are used as a reference on the glass substrate. A pattern is formed by positioning the photomask and performing divided exposure. As a result, the plurality of photomasks are accurately positioned, and the connecting portions of the corresponding patterns between the photomasks are properly continued, so that a high-quality pattern can be manufactured. Moreover, since it is possible to avoid an increase in the size of the photomask, it is ensured that the accuracy of maintaining the accuracy of the photomask itself is ensured, and not only the photomask can be easily held in the exposure apparatus, but also expansion correction due to temperature is not required. Thus, the work can be simplified. Accordingly, various problems can be avoided when a large-sized photomask is used on a recent large-sized glass substrate and a pattern is formed by batch exposure.

  Moreover, it is preferable that the alignment mark has a cross shape with a middle portion removed as a positioning reference portion.

  In this way, four linear mark portions are arranged at intervals of 90 ° to form an alignment mark, and the middle of the alignment mark portion is a positioning reference portion having no mark portion. In this case, the individual linear mark portions are preferably arranged so as to be parallel to the vertical side or the horizontal side of the glass substrate. As described above, when the alignment mark has a cross shape with the center removed, when the center of the alignment mark is detected by image processing, it is possible to enjoy the advantage that the processing can be easily performed without malfunction.

  And it is preferable that the alignment mark obtained by the above methods is formed in the glass substrate for flat panel displays.

  In this way, it becomes possible to appropriately cope with the recent increase in the size of glass substrates for flat panel displays (for example, base glass for taking a plurality of glass panels), and in particular, glass for plasma displays. Suitable for substrates. In this case, as a matter of course, it is preferable to form alignment marks at a plurality of locations on the glass substrate.

  On the other hand, the alignment mark stamping apparatus according to the present invention, which was created to solve the above technical problem, has a positioning alignment mark on the glass substrate before the step of forming a pattern on the glass substrate. An apparatus used for engraving is characterized in that a thermal printer having a thermal print head capable of moving toward and away from a glass substrate is provided.

  According to such a configuration, when the alignment mark is formed on the glass substrate, the thermal print head of the thermal printer is moved relatively close to the glass substrate (the surface of the substrate), and the print head is moved. Is pressed against the glass substrate via a ribbon (ribbon formed from the material of the alignment mark), so that the alignment mark made of a material such as metal or resin is properly thermally transferred onto the glass substrate. After the alignment mark is formed in this way, the thermal print head moves away relative to the glass substrate and reaches the standby position. As a result, the problems caused by the photo process using the conventional resist described above, the problems caused by the laser marker, and the problems caused by the ink jet method are effectively avoided.

  In this case, the pattern is preferably formed by divided exposure using a plurality of photomasks corresponding to a plurality of surface regions on the glass substrate.

  In this way, particularly when the glass substrate is a large plate, a pattern is formed by positioning a plurality of photomasks with the alignment mark as a reference and performing divided exposure. It is possible to enjoy the same functions and effects as described above.

  In addition to the above configuration, this apparatus includes a ribbon formed from the material of the alignment mark, a take-up reel of the ribbon, and the thermal print head as a unit relatively close to the glass substrate. It is preferable to be configured to be able to move and separate.

  In this way, when the alignment mark is formed on the glass substrate, the thermal print head, the ribbon, and the ribbon take-up reel move together relatively to the glass substrate, and the thermal print The head is pressed against the glass substrate via the ribbon. Then, after the alignment mark is formed, the above three members integrally move relative to the glass substrate and reach the standby position. This causes problems when the thermal print head moves independently and the ribbon and ribbon take-up reel are held at a certain position close to the glass substrate. Specifically, the ribbon and the glass substrate are in contact with each other. Inconvenience, and a problem in the installation space of the ribbon and the ribbon take-up reel are appropriately avoided.

  In addition, it is preferable that the heating element disposed on the front end surface of the thermal print head has a cross shape with the center removed.

  In this way, when the thermal print head is pressed against the glass substrate through the ribbon, the alignment mark engraved on the glass substrate by the action of the heating element has a cross shape with the center extracted as a positioning reference portion. Will be presented. When the alignment mark has such a shape, the same effects as those already described can be obtained.

  It is preferable that the glass substrate on which the alignment mark is engraved with the above configuration is a glass substrate for a flat panel display.

  In this way, as described above, it is possible to appropriately cope with the recent increase in the size of glass substrates for flat panel displays. Also in this case, as a matter of course, it is preferable to form alignment marks at a plurality of locations on the glass substrate. Therefore, the above-described thermal printer (thermal print head, ribbon and ribbon take-up reel) is used for one glass substrate. When a plurality of units, specifically, a glass substrate is transported and a flow operation is performed, it is preferable that a plurality of units are provided in a direction orthogonal to the transport direction.

  As described above, according to the present invention, since the alignment mark is engraved on the glass substrate using the thermal printer, the alignment mark can be obtained by simply pressing the print head of the thermal printer against the glass substrate. The heat transfer is properly performed on the substrate. As a result, problems such as increase in the number of treatments and deterioration of work efficiency as in the case of a photo process using a conventional resist, adverse effects due to fine powder as in the case of a laser marker, reduction in the strength of the engraved portion, and generation of cracks As well as problems such as difficulty in controlling the droplet diameter and discharge position, difficulty in maintaining the proper surface properties of the glass substrate, and difficulty in maintaining good mark shape. Avoided at once.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, based on the perspective view shown in FIG. 1, the alignment mark marking device which concerns on embodiment of this invention, and its schematic structure are demonstrated. As shown in the figure, the alignment mark marking device 1 has a marking unit 4 disposed in the middle of the transport direction of the glass substrate 2 in the transport path 3. The marking unit 4 is disposed above the transport conveyor 6 composed of a number of rollers 5 arranged in the transport path 3, and moves toward and away from the glass substrate 2 placed on the transport conveyor 6 from above. A lifting head 7 capable of recoil is provided.

  In the present embodiment, a base frame material 8 extending in a direction orthogonal to the transport direction so as to straddle the upper side of the transport conveyor 6 is fixedly installed on a floor surface or a base, and a single base frame material 8 is provided. A pair of marking units 4 are held so as to be movable along the base frame member 8 while being separated from each other by a predetermined dimension. Therefore, if the size of the glass substrate 2 (particularly the dimension in the direction orthogonal to the conveyance direction of the glass substrate 2) is changed, the pair of marking units 4 can be moved along the base frame material 8 accordingly. It will be good.

  As shown in FIG. 2, the elevating head 7 held by the marking unit 4 houses main components of the thermal printer 9, specifically, a thermal print head 10 disposed at the lower end, A ribbon 12 guided and moved by a plurality of guide rollers 11 so as to pass directly below the thermal print head 10 and a ribbon take-up reel 13 for taking up and driving the ribbon 12 are accommodated. Therefore, the thermal print head 10, the ribbon 12, and the ribbon take-up reel 13 move up and down as a unit. In this case, as a material for forming the ribbon 12, a metal made of gold, silver, copper, aluminum or the like, or a resin made of polyimide or the like is appropriately selected and used.

  The overall configuration of the alignment mark marking device 1 will be described. As shown in FIG. 3, a head actuator 14 is attached to the upper portion of the marking unit 4 held by the base frame member 8, and the thermal print head 10 is moved to the lower end. The elevating head 7 included in the unit is driven to move up and down in the vertical direction by the operation of the head actuator 14. Further, below the glass substrate 2 in the conveyance path 3, in addition to a large number of conveyance rollers 5, a plurality of lift-up members 15 that can be moved up and down, and a vertical movement that is disposed opposite to the thermal print head 10 are possible. A suction surface plate 16 is provided.

  As shown in FIG. 4, the lift-up member 15 is configured to move the glass substrate 2 up to a predetermined height and align the glass substrate 2 in a horizontal plane by a linkage operation with the centering device. . Further, the suction surface plate 16 moves up and down by the operation of the surface plate actuator 17 and moves upward to the position shown in FIG. 4, that is, the position where the alignment mark is imprinted on the glass substrate 2. The substrate 2 is configured to be sucked and held. The suction surface plate 16 extends from one end to the other end in a direction orthogonal to the transport direction in the transport path 3 (see FIG. 1), and therefore thermal printing is performed with the glass substrate 2 supported from below without being bent. The pressing force of the head 10 is received.

  On the other hand, on the front end surface (lower end surface) of the thermal print head 10, a heating element (heating resistor) 19 having a cross shape with the middle 18 removed is arranged. Specifically, the four heating elements with the middle 18 area as a reference center are arranged. The heating elements 19 are arranged at intervals of 90 °. Therefore, when the alignment mark 20 for positioning is engraved on the glass substrate 2 using this thermal print head 10 (see FIG. 7), the alignment mark 20 is a cross whose center is extracted as a positioning reference portion. It will exhibit a shape.

  In the present embodiment, as shown in FIG. 6, a total of six thermal print heads 10 are arranged along the both sides of the glass substrate 2, three at regular intervals. The alignment mark marking device 1 is provided with a centering device having a plurality of cylindrical bodies 21 for centering the glass substrate 2 in contact with its four sides. Accordingly, a total of six alignment marks 20 are engraved as shown in FIG.

  According to the alignment mark marking device 1 having the above configuration, the following operation is performed. That is, after the glass substrate 2 transported by the transport conveyor 6 composed of a large number of rollers 5 shown in FIG. 1 stops at a predetermined position, the lift-up member 15 shown in FIG. It is lifted to the height position shown, and alignment in the horizontal plane is performed by the plurality of cylindrical bodies 21 of the centering device.

  Next, the suction surface plate 16 is moved up by the operation of the surface plate actuator 17 to hold the glass substrate 2 held at the height position in FIG. 4 from below, and under such a state, The lift head 7 is lowered by the operation of the head actuator 14 of the marking unit 4. As a result, the thermal print head 10 that protrudes and is attached to the lower end of the elevating head 7 is pressed against the surface of the glass substrate 2 via the ribbon 12, and as a result, as shown in FIG. A plurality of alignment marks 20 are imprinted on the surface of the glass substrate 2.

  Thereafter, a fine wiring pattern made of a conductive film is formed on the glass substrate 2 by performing divided exposure using a plurality of photomasks using the plurality of alignment marks 20 as a positioning reference. In this case, as the material of the ribbon 12, that is, the material of the alignment mark 20, a material suitable for the subsequent process can be selected. For example, in the process of forming a wiring pattern made of a conductive film, if the alignment mark is not used after divided exposure, it is preferable to select a material that disappears along with development and cleaning. It is also possible to select materials that can be used in

  And when it is desired to change the material, it is only necessary to replace the ribbon 12, so that the material can be changed very easily. Further, when the shape of the alignment mark 20 is to be changed (for example, when the cross shape is to be changed to a circular shape), only the thermal print head 10 (head portion) can be replaced and the same apparatus can be used. This is advantageous in terms of cost and cost.

  The alignment mark marking method and the alignment mark marking apparatus of the present invention are a glass substrate used for manufacturing glass panels for various image display devices such as a plasma display, a liquid crystal display, an electroluminescence display, a field emission display, and various electronic display functions. When an alignment mark is formed on a glass substrate that requires positioning with a photomask or other member in a pattern forming process or other process, such as a glass substrate used as a base material for forming an element or a thin film Can be used effectively.

It is a schematic perspective view which shows the alignment mark marking apparatus which concerns on embodiment of this invention. It is a schematic front view which shows the principal part of the thermal printer which is a component of the said alignment mark marking apparatus. It is a side view which shows the principal part of the said alignment mark stamping apparatus. It is a side view which shows the principal part of the said alignment mark stamping apparatus. It is a schematic bottom view which shows the thermal printer head which is a component of the said alignment mark marking apparatus. It is a schematic plan view which shows the said alignment mark stamping apparatus. It is a top view which shows the glass substrate in which the alignment mark was stamped by the said alignment mark stamping apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Alignment mark stamping apparatus 2 Glass substrate 9 Thermal printer 10 Thermal print head 19 Heating element 20 Alignment mark

Claims (9)

Before performing the step of forming the pattern on the glass substrate, in the method of marking the alignment mark for positioning on the glass substrate,
An alignment mark marking method, wherein the alignment mark is stamped on a glass substrate using a thermal printer.   The alignment mark marking method according to claim 1, wherein in the step of forming the pattern, division exposure is performed using a plurality of photomasks corresponding to a plurality of surface regions on the glass substrate.   The alignment mark marking method according to claim 1, wherein the alignment mark has a cross shape with a middle portion extracted as a positioning reference portion.   A glass substrate for a flat panel display, wherein an alignment mark for positioning is formed by the method according to claim 1. In the apparatus used to imprint alignment marks for positioning on the glass substrate before performing the step of forming a pattern on the glass substrate,
An alignment mark marking apparatus comprising a thermal printer having a thermal print head that can move relative to and away from a glass substrate.   6. The alignment mark marking device according to claim 5, wherein the pattern is formed by divided exposure using a plurality of photomasks corresponding to a plurality of surface regions on the glass substrate.   The ribbon formed from the material of the alignment mark, the take-up reel of the ribbon, and the thermal print head are integrally moved relative to and away from the glass substrate. The alignment mark stamping device according to claim 5, wherein the alignment mark stamping device is configured.   The alignment mark marking device according to any one of claims 5 to 7, wherein a heating element disposed on a front end surface of the thermal print head has a cross shape with a middle portion removed.   The alignment mark stamping device according to claim 5, wherein the glass substrate is a glass substrate for a flat panel display.

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