TW201828224A - Method for manufacturing glass substrate - Google Patents

Abstract

This method for manufacturing a glass substrate includes a process 1 for manufacturing a glass substrate from a mother glass plate. In the process 1 for manufacturing a glass substrate, in a defect detection step S1, an overall defect which comprises a pass defect that has passed a predetermined criterion and a fail defect that has failed the criterion is detected from the mother glass plate. Then, in a lot formation step S3, a lot is formed from a plurality of the mother glass plates. In a data calculation step S4, the average number of the overall defects or the pass defects per mother glass plate in the lot is calculated. In a lot determination step S5, a determination is made on whether the lot passes or fails on the basis of the average number of the overall defects or the pass defects calculated in the data calculation step S4.

Description

Manufacturing method of glass substrate

[0001] The present invention relates to a method for manufacturing a glass substrate used in an electronic device.

[0002] As is known, in electronic devices such as flat panel displays (FPDs) such as liquid crystal displays, plasma displays, and organic EL (Electro Luminescence) displays, organic EL lighting, touch panels, and even solar cell panels, Glass substrates are widely used. [0003] Such a glass substrate is manufactured by cutting out a glass plate called a mother glass (hereinafter referred to as a mother glass plate), and is a general example (for example, refer to Patent Document 1). Prior Art Literature Patent Literature [0004] Patent Literature 1: International Publication No. 03/087923

Problems to be Solved by the Invention [0005] However, there may be defects such as bubbles or foreign matter in the mother glass plate or glass substrate that circulates through the manufacturing process of the glass substrate. In order to prevent such defects from causing defects in electronic equipment, a mother glass plate or a glass substrate is inspected during the manufacturing process of the glass substrate. However, even if the glass substrate is completed by such inspection, there is a possibility that problems caused by defects may occur in the manufacturing process of electronic equipment. [0006] In view of the foregoing, the present invention has a technical problem of manufacturing a glass substrate that does not cause problems as much as possible in a manufacturing process of an electronic device. Technical means to solve the problem [0007] The manufacturing method of the glass substrate of the present invention, which is created to solve the aforementioned problem, is characterized by including a process of manufacturing a glass substrate from a mother glass plate, and the aforementioned process of manufacturing a glass substrate from the aforementioned mother The glass plate is formed by a plurality of mother glass plates after detecting a total defect consisting of a qualified defect that is determined to be qualified under a predetermined judgment standard and an unqualified defect that is determined to be unqualified under the foregoing judgment standard. One batch determines the pass or fail of the batch based on the average number of the total defects or the qualified defects per one piece of the mother glass plate calculated for the batch. Here, the batch refers to an assembly of a plurality of mother glass plates, and is a unit for carrying out, manufacturing, and the like (hereinafter the same). [0008] A qualified defect is a defect with a low probability of causing fatal failure in an electronic device, and a defective defect is a defect with a high probability of causing fatal failure in an electronic device. An unqualified defect is equivalent to a defect that is set to be unqualified in a conventional defect inspection, and a qualified defect is equivalent to a defect that is set to pass in a conventional defect inspection. That is, among the glass substrates that have passed the conventional inspection for defects, the glass substrates containing unqualified defects will be removed. Therefore, defects that may cause problems in the manufacturing process of electronic equipment are mostly qualified defects. . According to the above configuration, based on the average number of each mother glass plate with total defects (qualified defects and unqualified defects), if the batch is qualified or not, it is a qualified defect but the number of defects in each batch is The number will be limited, so not only can the problems caused by defective defects occur in the manufacturing process of electronic equipment, but also the problems caused by qualified defects can be suppressed. In addition, in the above-mentioned configuration, when determining whether a lot is qualified based on the average number of qualified substrates per piece, the term is also commonly used. That is, according to the manufacturing method of the glass substrate of this invention, the glass substrate which does not cause a problem as much as possible in the manufacturing process of an electronic device can be manufactured. [0009] In the above configuration, it is preferable that the mother glass plate without the unqualified defect is determined to be qualified, and the mother glass plate with the unqualified defect is determined to be unqualified, and only those that are determined to be qualified are determined to be qualified. The mother glass sheet is used to form the batch, and when the batch is qualified, the average number of the qualified defects per piece of the mother glass sheet calculated for the batch is used. [0010] With this configuration, there are no unqualified defects in the batch of mother glass plates, so there is no need to consider the unqualified defects in batches of fatal defects caused by the manufacturing process of electronic equipment. [0011] In the above configuration, when the pass of the lot is determined, based on the pass of each of the mother glass plates from the group consisting of the types of the glass plates that can be taken from the mother glass plate The average number of defects may be used to select the aforementioned variety that satisfies the criteria for determining the aforementioned variety. Here, the type refers to the type of the glass substrate (the same applies hereinafter) which is determined depending on the size, use, and the like. 001 [0012] The determination criterion for this variety is set for each variety, and batches may become unqualified under one variety but pass under other varieties. Therefore, if the variety is selected, the batch qualification can be increased. In this way, the batch of mother glass plates can be effectively utilized. [0013] In the above configuration, the variety may be selected based on the average number of qualified defects per one piece of the glass substrate calculated based on the average number of qualified defects per one piece of the mother glass plate. [0014] With this configuration, the average number of qualified defects per one piece of the glass substrate calculated based on the average number of qualified defects per one piece of the mother glass plate is used, so that the variety can be selected more appropriately . [0015] In the above-mentioned configuration, the group may include a variety having a maximum size that can be manufactured from one piece of the mother glass plate and a variety having a size smaller than the maximum size. [0016] In the case of a product having a size smaller than the maximum size (downsize product), there is a high possibility that the lot will pass, and the pass of the lot can be increased. In this way, batch mother glass sheets can be used more effectively. [0017] In the above configuration, when the distribution of the qualified defects in the mother glass plate is biased, it is also possible to select a variety that uses only the area with few qualified defects. 00 [0018] With this configuration, even if the lot is determined as an unacceptable lot based on the average number of acceptable defects per mother glass plate, it may become acceptable by selecting a variety. Therefore, the batch qualification can be increased, and the mother glass plate of the batch can be effectively utilized. [0019] In the above configuration, when the number of the qualified defects of the mother glass plate is increased, the criteria for determining the qualified defects and the unqualified defects may be tightened. [0020] With this configuration, it is possible to suppress an increase in the number of qualified defects in a batch of mother glass plates. In this way, it is possible to suppress an increase in the average number of qualified defects per mother glass plate. Therefore, it is possible to suppress an increase in the number of defectives in a batch based on the average number of defective defects per mother glass plate. Effect of the Invention 002 [0021] As described above, according to the present invention, it is possible to manufacture a glass substrate that does not cause problems as much as possible in the manufacturing process of electronic equipment.

[0023] Hereinafter, this embodiment will be described based on the drawings. [0024] FIG. 1 is a schematic schematic flowchart of a process 1 of manufacturing a glass substrate 3 included in a method for manufacturing a glass substrate according to an embodiment of the present invention. 2A to 2F are schematic plan views showing the arrangement of the glass substrate 3 on the mother glass plate 2. The method for manufacturing a glass substrate according to the embodiment of the present invention includes a process 1 of manufacturing a glass substrate 3 from a mother glass plate 2. The pre-process may include a process of forming a glass ribbon by a down draw method, a float method, or the like, and then manufacturing a mother glass plate 2 from the glass ribbon. [0025] The glass substrate 3 is manufactured by cutting out from the mother glass plate 2. At this time, the size or number of glass substrates 3 cut from one mother glass plate 2 varies depending on the type of the glass substrate 3. [0026] For example, the glass substrate 3 shown in FIG. 2A is a product of the largest size that can be taken from the mother glass plate 2 (hereinafter referred to as the largest-size product 3a). In addition, the glass substrate 3 shown in FIGS. 2B to 2F is a reduced-size variety 3b that is smaller in size than the glass substrate 3 in FIG. 2A. [0027] In addition, for the glass substrate 3 shown in FIGS. 2A and 2B, the glass substrate 3 cut from one mother glass plate 2 is one. In the glass substrate 3 shown in FIGS. 2C to 2F, the number of pieces cut from one mother glass plate 2 is respectively 2, 3, 4, and 3. [0028] In addition, the glass substrate 3 shown in FIG. 2C to FIG. 2E, the glass substrate 3 cut from one mother glass plate 2 is of the same size (same species), and the glass substrate 3 shown in FIG. The glass substrate 3 cut from the mother glass plate 2 has different sizes (different types). There are a plurality of types that can be taken from one mother glass plate 2 in this manner, and it is preferable to form a group composed of these types in advance, and it is selected in view of the demand trend or the operating condition of the manufacturing line. [0029] As shown in FIG. 1, a process 1 for manufacturing a glass substrate includes a defect detection process S1, a mother glass plate determination process S2, a batch formation process S3, a data calculation process S4, and a batch determination process S5. [0030] In the defect detection process S1, a defect existing on the mother glass plate 2 is detected by a well-known image inspection device. This defect is, for example, a bubble, a foreign object, and the like, and is composed of a qualified defect that is judged to be qualified under a predetermined judgment criterion, and a defective defect that is judged to be unqualified under the aforementioned judgment criterion. The judgment criterion of this embodiment is a predetermined defect size. Defects smaller than this size are qualified defects, and defects larger than this size are unqualified defects. The size of the defect used as a criterion for this determination is appropriately set according to the type. For example, if the defect is a bubble, it is 50 μm to 1000 μm, and if the defect is a foreign object, it is 20 μm to 300 μm. In the image inspection device, for example, if it is a bubble, a person with a diameter of 10 μm or more is detected as a defect, and if it is a foreign object, a person with a diameter of several μm or more is detected as a defect. [0031] In addition, in the defect detection process S1, information such as the type of defects (bubbles, foreign objects, etc.), the number, the size, and the coordinates detected by a well-known image inspection device is obtained. [0032] The mother glass plate determination process S2 is based on the number of unqualified defects detected in the defect detection process S1, and the pass or fail of the mother glass plate 2 is determined one by one. For example, if the number of defective defects is equal to or less than a predetermined threshold value, the mother glass plate 2 is determined to be acceptable, and the process proceeds to batch forming process S3. On the other hand, if the number of unacceptable defects is more than a predetermined threshold, the mother glass plate 2 is judged as unacceptable and is processed. In addition, other materials obtained from the defect detection process S1 (types of unqualified defects such as bubbles and foreign objects, coordinates of unqualified defects, etc.) may be added to the material for determining the pass or fail of the mother glass plate 2. The predetermined threshold for non-conformity defects is, for example, 0 (zero) per mother glass substrate. In this case, the pass or failure is determined by the presence or absence of non-conformance defects, and the mother glass plate 2 without non-conformity defects becomes A pass, and the mother glass plate 2 with an unacceptable defect becomes unacceptable. [0033] In the batch forming process S3, only the mother glass sheet 2 judged to be qualified in the mother glass sheet determination process S2 is gathered into a plurality of pieces to form one batch. [0034] In the data calculation process S4, from the defect data obtained in the defect detection process S1, the batch determination data used in the batch determination process S5 is calculated. In this batch determination data, the main ones are "the average number of defects per one sheet of the mother glass plate 2 in one batch" and "per one sheet of the glass substrate 3 in one batch" The average number of defects in the film. " Among the average number of these defects, both qualified defects and unqualified defects (total defects) can be targeted, and only qualified defects can be targeted. Here, the number of defective defects contained in one mother glass plate tends to be smaller than the number of defective defects. Therefore, even if the average number of defects including unqualified defects is large, the number of qualified defects can be evaluated, and the problems caused by qualified defects in the manufacturing process of electronic equipment can be suppressed. [0035] Among the "average number of defects per mother glass plate 2 in one batch", there are a first average number and a second average number. The first average number is calculated for the number of all kinds of defects. The second average number is a number calculated for the number of specific types among defects. In this embodiment, the second average number is two types for "bubble" and "foreign body", but it may be one type or three or more types. [0036] "The average number of defects per glass substrate 3 in one batch" (hereinafter referred to as the third average number) is based on each cut of the glass substrate 3 based on the first average number. Calculate the size variety 3b. For example, for the third average number, when the area of the mother glass plate 2 is set to Sm and the area of the glass substrate 3 is set to Sb, the third average number is equal to the first average number = Sb / Sm This formula is calculated. [0037] In the batch determination process S5, the pass or fail of the batch is determined based on the average number of defects (first average number) per one piece of the mother glass plate 2 calculated for one batch. [0038] In addition, in the batch determination process S5, when the distribution of qualified defects in the mother glass plate 2 is biased, a cut-out size 3b that uses only areas with fewer qualified defects is selected. [0039] In addition, in the lot determination process S5, the kind of the glass substrate 3 manufactured from the mother glass plate 2 of the lot is selected from the lot group based on the first average number. In this case, the group of varieties includes the maximum size variety 3a and the reduced size variety 3b. The cut size 3b in this case is selected based on the third average number. In addition, the cut size item 3b as a candidate for selection in the lot determination process S5 is selected in view of the demand trend, the operation status of the manufacturing line, and the like. [0040] In the lot determination process S5, the lot that is judged to be qualified will be transferred to a cutting line, and the glass substrate 3 of the selected variety is cut out from the mother glass plate 2 of the lot and manufactured. . On the other hand, in the lot determination process S5, the lot which is judged as unacceptable is subject to disposal. [0041] In addition, in this embodiment, the determination criterion of the glass substrate 3 of the maximum size variety 3a and the determination criterion of the glass substrate 3 of the reduced size variety 3b may be the same or different. The criterion for determining the maximum size variety 3a and the reduced size variety 3b can be set by a threshold (allowable number of defects). In the case where the first average number of all kinds of qualified defects is used for the determination, the threshold value can be set to, for example, 0.1 to 5. [0042] In the reduced-size variety 3b, the area of the glass substrate 3 is reduced compared to the maximum-size variety 3a, and therefore the third average number (average number of defects per glass substrate 3) is also reduced. Similarly, among the reduced-size varieties 3, the smaller the size of the glass substrate 3 is, the smaller the third average number is. Therefore, if the threshold is the same in the maximum size variety 3a and each of the reduced size varieties 3b, the smaller the area of the glass substrate 3, the easier it is to meet the determination criteria of the variety, that is, the more the reduced size variety can meet the determination criteria The threshold. [0043] Next, the batch determination process S5 will be described in detail based on FIG. 3. [0044] Initially, in step S51, it is determined whether the distribution of qualified defects is biased. When the distribution of qualified defects is biased, the process proceeds to step S52, and when the distribution of qualified defects is not biased, the process proceeds to step S53. [0045] In step S52, it is determined whether each of the two types of the second average number (the average number of bubbles and the average number of foreign objects) satisfies the determination criterion of the maximum size type 3a. Specifically, when the second average number of both parties is equal to or less than a predetermined threshold, the largest size variety 3a is selected as the variety using the batch (step S54), and the batch is qualified (step S55). . When any second average number exceeds a predetermined threshold, the process proceeds to step S56. [0046] In step S56, it is determined whether or not there is a cut-out size item 3b in the area where the number of acceptable defects d is small in the mother glass plate 2 as shown in FIG. 4. [0047] In addition, among the varieties shown in FIG. 4 (the variety shown in FIG. 2B), the glass substrate 3 obtained from the mother glass plate 2 is one piece, but it may be a plurality of pieces. In addition, only one of the plurality of pieces may be used. The sheet is a region in which only a small number of acceptable defects d in the mother glass plate 2 are used. In addition, in the present embodiment, only the variety in the area with a small number of acceptable defects d is used, which is a reduced size variety 3b, but it may also be a maximum size variety 3a. [0048] In step S56, when there is a cut size variety 3b in the mother glass plate 2 where only qualified defects d are small, the cut size variety 3b is selected as the variety used in this batch (step S57), This lot is set as pass (step S58). In addition, when there are multiple types of cut sizes 3b in the area where the mother glass plate 2 has only a small number of qualified defects d, the one with the highest priority is selected among them. This priority is set in advance based on demand trends or operating conditions of manufacturing lines. [0049] In step S56, when the cut-size item 3b of only the area with fewer qualified defects d in the mother glass plate 2 is not used, the lot is set as unqualified (step S59). [0050] On the other hand, in step S53, it is determined whether or not the first average number (average number of defects of all types) satisfies the determination criterion of the maximum size variety 3a. Specifically, when the first average number is equal to or less than a predetermined threshold, the largest size variety 3a is selected as the variety using this batch (step S60), and this batch is set to pass (step S61). When the first average number exceeds a predetermined threshold, the process proceeds to step S62. [0051] In step S62, it is determined whether there is a reduced-size item 3b that satisfies the determination criterion. This determination is performed by assuming that the third average number is the number of defects after the glass substrate 3 is manufactured. [0052] In detail, the third average number of each type (glass substrate 3) is compared with the threshold value (allowable number of defects) which is the criterion for each type to determine whether there is a third average number. The number is the size 3b of the cut-off size below the threshold of the judgment criterion. [0053] In step S62, when there is a cut size variety 3b that satisfies the determination criterion, the cut size variety 3b is selected as the variety using this batch (step S63), and the batch is qualified (step S64) ). In addition, when there are a plurality of cut-size varieties 3b that satisfy the determination criterion, the one with the highest priority is selected among them. This priority order is selected in view of demand trends and operating conditions of manufacturing lines. [0054] In step S62, when the cut-size item 3b that does not satisfy the determination criterion is satisfied, the lot is determined as unacceptable (step S65). [0055] On the other hand, FIG. 5 is a schematic curve showing the relationship between the size of the defects detected in the defect detection process S1 and the cumulative detection number. The horizontal axis represents the size of the defect, and the vertical axis represents the number of defects detected in the mother glass plate 2 having a predetermined number of pieces accumulated. In addition, a curve A indicates a normal case, and a curve B indicates a case where a large number of defects are continuously detected. [0056] As shown by the curve B in FIG. 5, when a large number of defects are continuously detected, the number of defects of the mother glass plate 2 also increases of course, not only the number of defective defects increases, but also the number of qualified defects increases. Develop any countermeasures. In the batch determination process S5, the average number of the first and second batches will increase, and there is a possibility that the batches designated as unqualified will increase. In order to avoid such a situation, when a large number of defects are detected, the determination criterion b for distinguishing qualified defects and unqualified defects is set to be stricter than the determination criterion a for determining qualified defects and unqualified defects under normal circumstances ( b <a). That is, when a large number of defects are detected, the threshold for discriminating a qualified defect and an unqualified defect is reduced and changed to the strict side. [0057] Furthermore, the determination criterion b (threshold value) is set so that the first and second average numbers in the case where a large number of defects are detected become almost the same as in the normal case. Specifically, the determination criterion b is set so that the area of the region R2 is approximately equal to the area of the region R1. The region R1 is a region lower than the curve A and leftward than a. The region R2 is a region lower than the curve B and leftward than b. [0058] The area of the region R1 represents the total number of defects under the normal determination criterion a. In addition, the area of the region R2 indicates the total number of defects under the determination criterion b when a large number of defects are detected. Therefore, if the area of the region R2 is made equal to the area of the region R1, the first and second average numbers in the case where a large number of defects are detected can be made almost the same as in the normal case. [0059] The manufacturing method 1 of the glass substrate of this embodiment configured as described above can enjoy the following effects. [0060] Based on the average number of defects (the first average number), whether the batch is qualified or not is judged, so that problems caused by qualified defects in the manufacturing process of electronic equipment can be suppressed. That is, according to the manufacturing method 1 of the glass substrate of this embodiment, the glass substrate 3 which does not cause a problem as much as possible in the manufacturing process of an electronic device can be manufactured. [0061] The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of its technical idea. For example, in the batch determination process S5 of the above embodiment, if the distribution of qualified defects in the mother glass plate 2 is biased, the second average number is determined in step S52, but step S52 may be omitted.

[0062]

1‧‧‧ Manufacturing of glass substrates

2‧‧‧ mother glass

3‧‧‧ glass substrate

3a‧‧‧The largest size variety

3b‧‧‧ cut size varieties

S1‧‧‧Defect detection project

S2‧‧‧Mother glass plate determination project

S3‧‧‧ Batch formation project

S4‧‧‧Data calculation project

S5‧‧‧Batch determination project

d‧‧‧ qualified defect

[0022] [FIG. 1] A schematic schematic flowchart of a process for manufacturing a glass substrate included in a method for manufacturing a glass substrate according to an embodiment of the present invention.图 [Fig. 2A] A schematic plan view showing the arrangement of a glass substrate on a mother glass plate.图 [Fig. 2B] A schematic plan view showing the arrangement of a glass substrate on a mother glass plate.图 [Fig. 2C] A schematic plan view showing the arrangement of a glass substrate on a mother glass plate.图 [Fig. 2D] A schematic plan view showing the arrangement of a glass substrate on a mother glass plate.图 [Fig. 2E] A schematic plan view showing the arrangement of a glass substrate on a mother glass plate.图 [Fig. 2F] A schematic plan view showing the arrangement of a glass substrate on a mother glass plate.图 [Fig. 3] A flowchart for explaining batch judgment.图 [Fig. 4] A schematic plan view showing the distribution of qualified defects on the mother glass.图 [Figure 5] Schematic curve of the relationship between the size of the defect and the cumulative detection number.

Claims (7)

A manufacturing method of a glass substrate is a manufacturing method of a glass substrate including a process of manufacturing a glass substrate from a mother glass plate, characterized in that: In the aforementioned glass substrate manufacturing process, detecting from the aforementioned mother glass plate is performed by a predetermined judgment standard. After a total defect consisting of a qualified defect that is determined to be qualified and a failed defect that is determined to be unqualified under the aforementioned determination criteria, a batch is formed from a plurality of the aforementioned mother glass plates. The average number of the total defects or the qualified defects per one piece of the mother glass plate is calculated to determine whether the batch is qualified. The method for manufacturing a glass substrate according to item 1 of the scope of patent application, wherein the mother glass plate without the defective defects is judged to be qualified, and the mother glass plate with the defective defects is judged to be unqualified. The aforementioned batch is formed only by the aforementioned mother glass plate that is judged to be qualified, and when determining whether the batch is qualified, the average number of qualified defects per one piece of the mother glass plate calculated for the batch is used. The method for manufacturing a glass substrate according to item 2 of the scope of patent application, wherein when determining whether the batch is qualified or not, from the group consisting of varieties of the glass plate that can be taken from the mother glass plate, Based on the average number of the qualified defects per one piece of the mother glass plate, the variety that satisfies the determination criteria of the variety is selected. The method for manufacturing a glass substrate according to item 3 of the scope of patent application, wherein the average number of qualified defects per one piece of the glass substrate is calculated based on the average number of qualified defects per one piece of the mother glass plate. Number to select the aforementioned variety. The method for manufacturing a glass substrate according to item 3 or item 4 of the scope of patent application, wherein the aforementioned group includes the largest size variety that can be manufactured from one piece of the aforementioned mother glass plate, and a size smaller than the aforementioned maximum size. Variety of sizes. The method for manufacturing a glass substrate according to any one of claims 3 to 5 of the scope of application for a patent, wherein when the distribution of the qualified defects in the mother glass plate is biased, only using the qualified defects is selected. Of the region. The method for manufacturing a glass substrate according to any one of claims 3 to 6 of the scope of patent application, wherein when the number of the qualified defects of the mother glass plate is increased, the qualified defects and the aforementioned The criteria for determining unqualified defects are becoming stricter.