WO2020158330A1

WO2020158330A1 - Method for manufacturing glass substrate

Info

Publication number: WO2020158330A1
Application number: PCT/JP2020/000511
Authority: WO
Inventors: 敬一吉野; 西川　佳範
Original assignee: 日本電気硝子株式会社
Priority date: 2019-01-31
Filing date: 2020-01-09
Publication date: 2020-08-06
Also published as: JP2020121911A

Abstract

This method for manufacturing a glass substrate from a mother glass sheet includes: a defect detection step S11 of detecting an acceptable defect and an unacceptable defect that are present on the mother glass sheet, the acceptable defect being determined as acceptable by a predetermined criteria and the unacceptable defect being determined as unacceptable by the predetermined criteria; and a mother glass sheet determination step S12 of determining the quality of the mother glass sheet on the basis of the results of the defect detection step S11. An average value of the number of the acceptable defects per mother glass sheet is calculated as a monitored value for a plurality of the mother glass sheets which were determined as having good quality in the mother glass sheet determination step S12, and the criteria is changed on the basis of the monitored value.

Description

Glass substrate manufacturing method

The present invention relates to a method for manufacturing a glass substrate used in, for example, electronic equipment.

As is well known, glass substrates are widely used in electronic devices such as flat panel displays (FPD) such as liquid crystal displays, plasma displays, and organic EL displays, organic EL lighting, touch panels, and solar cell panels. There is.

　This type of glass substrate is usually manufactured by cutting out from a glass plate called mother glass (hereinafter referred to as a glass original plate) (see, for example, Patent Document 1).

International Publication No. 03/087923 International Publication No. 2018/116756

By the way, in Patent Document 2, the defects detected in the glass original plate are classified into pass defects that are determined to be pass according to a predetermined determination criterion and reject defects that are determined to be rejected according to the determination criterion, It is disclosed that the number of the passing defects is used for the pass/fail judgment of the lot formed of the glass original plate. More specifically, it is disclosed that the average number of passing defects per glass original plate is calculated for each lot, and the pass/fail of the lot is determined.

The number of passing defects varies in the short term (for example, several minutes to several hours) or in the long term (for example, more than several hours) due to various factors. In the method described in Patent Document 2, since the number of passing defects is managed in lot units, long-term fluctuations can be grasped, but short-term fluctuations are difficult to grasp. Therefore, as the number of passing defects increases in a short period of time, the average number of passing defects in the lot increases, and as a result, the quality of the product deteriorates or the lot fails.

In view of the above circumstances, the present invention is a technical object to suppress an increase in the average number of passing defects for a lot when the number of passing defects of a glass original plate used for manufacturing a glass substrate increases in a short period of time. And

The method for manufacturing a glass substrate according to the present invention for solving the above problems is a method for manufacturing a glass substrate from a glass original plate, and a passing defect that is determined as a pass by a predetermined determination criterion existing in the glass original plate, and Defect detection step of detecting a reject defect that is determined to be rejected by the determination criteria, based on the result of the defect detection step, the original plate determination step of determining the quality of the glass original plate, and the non-defective product in the original plate determination step In a method for manufacturing a glass substrate comprising a lot forming step of forming a lot with the glass original plate determined to be the plurality of glass original plates determined to be non-defective in the original plate determination step, one of the passing defects It is characterized in that an average value of the numbers is calculated as a monitoring value and the judgment criterion is changed based on the monitoring value.

Here, a lot is an assembly of a plurality of glass original plates, and is a unit for carrying, manufacturing, etc. (the same applies below). The pass defect is a defect that is unlikely to cause a fatal defect in the electronic device, and the fail defect is a defect that is highly likely to cause a fatal defect in the electronic device (hereinafter, the same). Further, the rejected defect corresponds to a defect that is rejected by the conventional defect inspection, and the accepted defect corresponds to a defect that is passed by the conventional defect inspection (hereinafter, the same). The glass original plate having a rejected defect may be discarded or the glass substrate may be taken from a portion having no rejected defect.

In the above configuration, the judgment standard of the defect detection process is changed based on the monitoring value which is the average value of the number of passing defects per sheet. For example, when the number of passed defects increases, it is possible to reduce the increased number of passed defects and set the monitoring value within a predetermined range by tightening the criterion for the defect detection process. On the other hand, when the number of passed defects decreases, the number of passed defects that have decreased can be increased and the monitoring value can be controlled within a desired range by loosening the criterion for the defect detection process. As described above, according to the method for manufacturing a glass substrate of the present invention, it is possible to stabilize the number of passing defects of the original glass plate used for manufacturing the glass substrate. Therefore, even if the number of passing defects increases in the short term, it is possible to suppress an increase in the average number of passing defects in the lot. This makes it possible to eliminate the occurrence of wire breakage, film peeling, and the like in the subsequent step of manufacturing an electronic device using a glass substrate (specifically, a patterning step or the like).

In the above configuration, the glass original plate for which the monitoring value is to be calculated may have been determined to be non-defective in the original plate determination step within a predetermined time.

In the above configuration, when the monitored value exceeds a preset upper limit value, the determination criterion is made strict, and when the monitored value is less than the preset lower limit value, the determination criterion is loosened. You may do it.

With this configuration, by tightening the criterion when the monitored value exceeds the upper limit, even if the number of passing defects increases, it is possible to reliably suppress the increase in the average number of passing defects in the lot. it can. Normally, if the monitored value is strict, the number of defects increases, so the manufacturing yield decreases.However, if the monitored value is less than the lower limit, the criterion is loosened, so the decrease in manufacturing yield should be minimized. You can

In the above configuration, before the lot forming step, a distribution step of distributing the glass original plate determined to be non-defective in the original plate determining step to a plurality of ejecting devices is provided, and in the lot forming step, the plurality of ejecting devices are The lots each forming the lot, and the lots formed by the plurality of extraction devices include the lots in which the cutting patterns of the glass substrate from the glass original plate are different from each other, and in the sorting step, the glass original plate is The passing defect may be distributed to the take-out device that forms the lot having the cut-out pattern that is not located in the region that becomes the glass substrate.

In the above configuration, the average value of the number of the passing defects per one glass original plate is calculated as a lot determination value for one lot, and the pass/fail of the lot is determined based on the lot determination value. Good.

With this configuration, the number of rejected lots can be suppressed by tightening the judgment criteria based on the monitoring value.

In this configuration, the number of glass original plates for which one lot determination value is calculated may be larger than the number of glass original plates for which one monitoring value is calculated.

With this configuration, when the judgment criteria are tightened, even if the original glass plate before the tightening criteria has already formed a lot in the middle, the glass original plate after the tightening criteria forms the same lot. It becomes possible to do. Therefore, it is possible to suppress the total number of passing defects in one formed lot. Therefore, the number of rejected lots can be suppressed more reliably.

In the above configuration, the criterion may be a defect size.

As described above, according to the present invention, it is possible to suppress an increase in the average number of passing defects for a lot when the number of passing defects of a glass original plate used for manufacturing a glass substrate increases in the short term.

It is a schematic plan view which shows the principal part of the manufacturing line which uses the manufacturing method of the glass substrate which concerns on embodiment of this invention. It is a flowchart which shows the main processes of the manufacturing method of the glass substrate which concerns on embodiment of this invention. It is a flow chart which shows the main processes of a defect inspection process. It is a graph for explaining the main steps of the defect inspection step. It is a top view which shows the cutting pattern of the glass substrate in a glass original plate. It is a top view which shows the cutting pattern of the glass substrate in a glass original plate. It is a top view which shows the cutting pattern of the glass substrate in a glass original plate. It is a top view which shows the cutting pattern of the glass substrate in a glass original plate.

Hereinafter, a mode for carrying out the present invention will be described with reference to the drawings.

The method for manufacturing a glass substrate according to the present invention is a method for manufacturing by cutting out a glass substrate from a glass original plate, and FIG. 1 shows a main part of a manufacturing line using the method for manufacturing a glass substrate according to an embodiment of the present invention. It is a schematic plan view shown. The main part of this manufacturing line is inspected by a conveyance path 2 such as a conveyor that conveys a plurality of glass original plates 1, a defect inspection device 3 that inspects the glass original plate 1 on the conveyance path 2 for defects, and a defect inspection device 3. A take-out device 4 for taking out the original glass plate 1 from the transport path 2 is a main component.

Further, as shown in FIG. 2, in the glass substrate manufacturing method according to the embodiment of the present invention, a defect inspection step S1 for inspecting a defect of the glass original plate 1 by the defect inspection apparatus 3 and a plurality of defect inspection steps S1 are performed. Distribution step S2 for allocating the glass original plate 1 to the unloading device 4, and after the allocating step S2, a lot forming step S3 for forming a lot L on the glass original plate 1 by the unloading device 4, a lot determination value calculation step S4, and a lot determination. And step S5.

Next, the steps performed in the defect inspection step S1 will be described in detail with reference to FIG.

In the first defect detection step S11, the defect inspection device 3 detects a defect existing in the glass original plate 1. This defect is, for example, a bubble, a foreign substance, or the like, and includes a pass defect that is determined to be pass according to a predetermined determination standard, and a reject defect that is determined to be fail according to the determination criterion. The criterion of this embodiment is a predetermined size of the defect, a defect smaller than this size is a passing defect, and a defect larger than this size is a rejecting defect. The defect size that serves as this criterion is appropriately set according to the size and application of the glass substrate to be manufactured. For example, if the defect is a bubble, it is 50 μm to 1000 μm, and if the defect is a foreign substance, it is 20 μm to 500 μm. is there. In the defect inspection apparatus 3, for example, if it is a bubble, 10 μm or more is detected as a defect, and if it is a foreign substance, a particle of several μm or more is detected as a defect.

In the defect detection step S11, data such as the type of defect (foam, foreign matter, etc.), the number, size, position (coordinates), etc. detected by the defect inspection apparatus 3 is acquired.

In the next original plate determination step S12, the quality of the glass original plate 1 is determined based on the result of the defect detection step S11 (from the defect data acquired in the defect detection step S11). The glass original plate 1 determined to be non-defective in the original plate determination step S12 is distributed to the take-out device 4 in a distribution step S2 described in detail later. The glass original plate 1 that is determined to be a defective product in the original plate determination step S12 is not allocated to the extraction device 4 and is discarded in the allocation step S2 described in detail later.

In the next monitoring value calculation step S13, the average value of the number of passing defects per sheet is monitored for a plurality of glass original plates 1 which have been determined to be non-defective in the original plate determination step S12 among the glass original plates 1 that have undergone the defect detection step S11. Calculate as a value.

The glass original plate 1 for which one monitoring value is to be calculated may be the glass original plate 1 determined to be non-defective in a predetermined time, or the predetermined number of glass original plates 1 determined to be non-defective. Good. When one monitor value is calculated for the glass original plate 1 that is determined to be a good product within a predetermined time, the predetermined time is, for example, 1 minute to 30 minutes. When one monitoring value is calculated for a predetermined number of glass original plates 1 determined to be non-defective, the number is, for example, 3 to 50.

In the next upper limit value determination step S14, it is determined whether or not the monitored value exceeds a preset upper limit value. If the monitored value exceeds the preset upper limit value, the criterion for judging the pass defect and the fail defect is made strict (S15). That is, the defect size, which is the criterion, is reduced. If the monitored value is less than or equal to the preset upper limit value, the process proceeds to the lower limit value determination step S16.

In the lower limit value determination step S16, it is determined whether or not the monitored value is less than a preset lower limit value. When the monitored value is less than the preset lower limit value, the criterion for judging the pass defect and the fail defect is loosened (S17). That is, the defect size, which is a criterion, is increased. When the monitored value is equal to or higher than the preset lower limit value, the determination criteria for the pass defect and the fail defect are maintained as they are (S18). That is, the defect size, which is the criterion, is not changed.

Note that the steps subsequent to the original plate determination step S12 in FIG. 3 are automatically performed by a computer (not shown).

Next, based on FIG. 4, a specific example of changes in the monitoring value and the judgment standard in the defect inspection step S1 will be described.

The judgment state in which the judgment criteria for the passing defect and the failing defect are normal is A, the judgment state in which the judgment criterion is one step stricter than the judgment state A is B, and the judgment condition in which the judgment criterion is one step stricter than the judgment state B is C. .. The range of change of the judgment standard when shifting from the judgment state A to the judgment state B is the same as the range of change of the judgment standard when shifting from the judgment state B to the judgment state A. Further, the range of change of the judgment standard when shifting from the judgment state B to the judgment state C and the range of change of the judgment standard when shifting from the judgment state C to the judgment state B are the same. The difference (change width) in the judgment criteria between the judgment states A and B may be the same as the difference (change width) in the judgment criteria between the judgment states B and C, or may be different. Good.

First, the monitoring value does not exceed the upper limit value or less than the lower limit value, and is in the state of maintaining the normal judgment standard (judgment status A). However, at time t1, the monitored value exceeds the upper limit value. Then, the judgment standard becomes stricter by one step (judgment state B). Then, at time t2, the monitoring value decreases, but since the monitoring value still exceeds the upper limit value, the criterion becomes one step more severe (determination state C). Then, at time t3, the monitoring value decreases below the upper limit value.

After that, for a while, the monitoring value does not exceed the upper limit value or less than the lower limit value, but at time t4, the monitoring value becomes less than the lower limit value. Then, the judgment standard is loosened by one step (judgment state B). Then, at time t5, the monitored value is once more than the lower limit value, but again at time t6, the monitored value becomes less than the lower limit value. Therefore, the determination standard is further loosened by one step (determination state A). Then, at time t7, the monitored value becomes equal to or higher than the lower limit value.

Next, the process after the defect inspection process S1 will be described.

In the lot forming step S3, a plurality of (three in the present embodiment) lots L are formed. As shown in FIG. 1, the lot L is formed by each of the take-out devices 4. The plurality of lots have different cutting patterns of the glass substrate 5 from the glass original plate 1. Examples of the cutout pattern include those illustrated in FIGS. 5A to 5D. The arrangement direction of the original glass plate 1 in FIGS. 5A to 5D corresponds to that in FIG.

The cutout patterns shown in FIG. 5B and FIG. 5C are the same in the shape and position of the region serving as the glass substrate 5 except that the glass original plate 1 is arranged in a different direction by 180°. Make one lot L.

The lot L arranged on the left side in FIG. 1 is formed by the glass master plate 1 having the cutout pattern shown in FIG. 5A, and the lot L arranged at the center in FIG. 1 is the glass master plate 1 having the cutout pattern shown in FIGS. 5B and 5C. It is assumed that the lot L formed and arranged on the right side in FIG. 1 is formed by the original glass plate 1 having the cutout pattern in FIG. 5D.

In the sorting step S2, the glass original plate 1 determined as a non-defective product in the original plate determination step S12 of the defect inspection step S1 is distributed from the transport path 2 to a plurality of take-out devices 4. The glass original plate 1 that is determined as a non-defective product in the original plate determination step S12 has a lot L having a predetermined cutting pattern even if it has a reject defect, and the take-out device 4 that forms the lot L has the defect. It is distributed. The predetermined cutout pattern is a cutout pattern in which the rejected defect of the original glass plate 1 is not located in at least one of the regions to be the glass substrate 5.

In the present embodiment, the target for determining whether or not the rejected defect of the glass original plate 1 is located is the effective area 5a of the glass substrate 5 in the area of the glass substrate 5. The effective area 5a of the glass substrate 5 is an area of the glass substrate 5 that is actually used when the glass substrate 5 is used in an electronic device or the like.

For example, in FIGS. 5A to 5D, if it is assumed that there is a defective defect at the position P of the original glass plate 1, in the cutout pattern of FIG. 5A, the defective defect is located in the effective region 5a of the glass substrate 5. To do. Therefore, in the distribution step S2, the glass original plate 1 having the defective defect at the position P is not distributed to the lot L (the one arranged on the left side in FIG. 1) having the cutout pattern shown in FIG. 5A.

In the cutout pattern of FIG. 5B, the rejected defect is located in the effective area 5a of the glass substrate 5. However, in the cutout pattern of FIG. 5C, the reject defect is not located in the area that becomes the effective area 5a of the glass substrate 5. In this case, the glass original plate 1 having the reject defect at the position P can be distributed to the lot L (the central arrangement in FIG. 1) having the cutout pattern of FIG. 5C.

In the cutout pattern of FIG. 5D, the rejected defect is located in one of the effective regions 5a of the four glass substrates 5. However, the rejected defect is not located in three of the effective regions 5a of the four glass substrates 5. In this case, the glass original plate 1 having the reject defect at the position P can be distributed to the lot L (the one arranged on the right side in FIG. 1) having the cutout pattern in FIG. 5D. The number of valid areas 5a in which no reject defect is located is not limited to three as shown in FIG. 5D, and if the number is one or more, the lot L having the cutout pattern in FIG. 5D can be distributed. However, in the cutout pattern having a plurality of effective areas 5a of the glass substrate 5, the number of the effective areas 5a in which the reject defect is not located does not necessarily have to be the glass original plate 1 which is one or more, and is equal to or more than the predetermined threshold value. The original glass plate 1 may be distributed. The threshold value may be appropriately determined according to the supply and demand status of the glass substrate 5, the operating status of the manufacturing line, and the like.

That is, as in the illustrated example of FIGS. 5A to 5D, when the rejected defect is located at the position P, it is possible to distribute the lot L to the central arrangement and the lot L to the right arrangement in FIG. In this way, when there are a plurality of lots L that can be distributed, the lot L of the distribution destination is selected in consideration of the supply and demand status of the glass substrate 5, the operating status of the manufacturing line, and the like.

When the original glass plate 1 has no rejected defects, or when the rejected defects are not located in the effective region 5a of the glass substrate 5 of the cutout pattern of FIG. 5A, the original glass plate 1 has the cutout pattern of FIG. 5A. Are assigned to the lot L (the one arranged on the left side in FIG. 1).

If the lot L having the cutout pattern in which the rejected defect is not located does not exist in the effective area 5a of the glass substrate 5, the glass original plate 1 is defective in the original plate determination step S12 of the defect inspection step S1. Is determined. In this case, the original glass plate 1 is not taken out by the take-out device 4, is carried by the carrying path 2, and is discarded.

In the lot determination value calculation step S4, based on the defect data acquired in the defect detection step S11, for one lot L formed in the lot formation step S3, the number of pass defects per glass original plate 1 The average value of is calculated as the lot judgment value. The number of glass original plates 1 (the number of glass original plates 1 forming one lot L) for which one lot determination value is calculated is larger than the number of glass original plates 1 for which one monitoring value is calculated. .. The number of original glass plates 1 forming one lot L is, for example, 100 to 500.

In the lot determination step S5, the pass/fail of the lot L is determined based on the lot determination value calculated in the lot determination value calculation step S4.

Specifically, if the lot judgment value is less than or equal to a predetermined threshold value, the lot L is judged to be acceptable and the lot L is transported to the next process. If the lot judgment value exceeds the predetermined threshold value, the lot L is judged to be unacceptable and is discarded.

The following effects can be enjoyed by the glass substrate manufacturing method of the present embodiment configured as described above.

Change the judgment standard based on the monitoring value, which is the average value of the number of passing defects per sheet. For example, when the number of passed defects increases, it is possible to reduce the increased number of passed defects and control the monitoring value within a desired range by tightening the criterion. On the other hand, when the number of passing defects decreases, the judgment standard can be loosened to increase the number of passing passing defects and control the monitoring value within a desired range. As described above, according to the method for manufacturing a glass substrate of the present embodiment, it is possible to stabilize the number of passing defects of the original glass plate used for manufacturing the glass substrate. Therefore, even if the number of passing defects increases in the short term, it is possible to suppress an increase in the average number of passing defects in the lot.

Further, in the distribution step S2, even if the original glass plate 1 has a defective defect, if there is a lot L having a predetermined cutting pattern, it is distributed to the take-out device 4 that forms the lot L. Therefore, it is possible to reduce the number of glass original plates 1 to be discarded as the glass original plates 1 having a reject defect.

Also, the average value of the number of passing defects per glass original plate 1 for one lot L is calculated as a lot judgment value, and the acceptance/rejection of lot L is judged based on the lot judgment value. The number of glass original plates 1 for which one lot determination value is calculated is larger than the number of glass original plates 1 for which one monitoring value is calculated. In this case, when the judgment standard is tightened, even if the glass original plate 1 before the judgment standard is tightened has already formed the lot L in the middle, the glass master plate 1 after the judgment standard is tightened is the same lot L. Can be formed. Therefore, it is possible to suppress the total number of passing defects in one formed lot L. Therefore, when the judgment standard is made strict based on the monitored value, the number of rejected lots L can be suppressed. Therefore, the number of lots L to be discarded can be reduced.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the technical idea thereof. For example, in the above-described embodiment, the glass original plate having the rejected defect is distributed to a plurality of lots having different cutting patterns, but such distribution is not necessarily required. In addition, in the above-described embodiment, the lot acceptance/rejection is determined based on the lot determination value, but such lot determination does not necessarily have to be performed.

In the above embodiment, the monitoring value calculation step S13, the upper limit value determination step S14, and the lower limit value determination step S16 are performed in the defect inspection step S1, but the monitoring value calculation step S13, the upper limit value determination step S14, and the lower limit value are performed in the distribution step S2. The determination step S16 may be performed. When the monitoring value calculation step S13, the upper limit value determination step S14, and the lower limit value determination step S16 are performed in the defect inspection step S1 or the distribution step S2, the monitoring value calculation step S13, the upper limit value determination step S14, and the lower limit value determination step are not always required. It is not necessary to perform S16, and the monitoring value calculation step S13, the upper limit value determination step S14, and the lower limit value determination step S16 may be performed about once every several times. Alternatively, without performing the monitoring value calculation step S13, the upper limit value determination step S14, and the lower limit value determination step S16 in the defect inspection step S1 or the distribution step S2, the monitoring value calculation step S13, the upper limit value determination step S14 at a predetermined time interval, The lower limit value determination step S16 may be performed. In short, the monitoring value calculation step S13, the upper limit value determination step S14, and the lower limit value determination step S16 may be performed so that the short-term fluctuation in the number of passed defects can be grasped.

In the above embodiment, the effective area 5a of the glass substrate 5 is the object for determining whether or not the reject defect of the glass original plate 1 is located, but it may be the area to be the glass substrate 5.

1 Glass Original Plate 5 Glass Substrate L Lot S1 Defect Inspection Step S11 Defect Detection Step S12 Original Plate Judgment Step S13 Monitoring Value Calculation Step S14 Upper Limit Value Judgment Step S15 Strict Judgment Standard S16 Lower Limit Judgment Step S17 Loosening Judgment Standard S18 Judgment standard maintenance step S2 Distribution step S3 Lot formation step S4 Lot judgment value calculation step S5 Lot judgment step

Claims

A method of manufacturing a glass substrate from a glass original plate, a defect that detects a pass defect that is determined to be pass according to a predetermined criterion existing in the glass plate and a fail defect that is determined to be a failure at the criterion. A detection step, based on the result of the defect detection step, a master plate determination step of determining the quality of the glass master plate, and a lot forming step of forming a lot with the glass master plate determined to be non-defective in the master plate determination step In the method of manufacturing a glass substrate,
For the plurality of glass original plates determined to be non-defective in the original plate determination step, an average value of the number of the passing defects per sheet is calculated as a monitoring value, and the determination standard is changed based on the monitoring value. A method for manufacturing a glass substrate having a characteristic feature.
The method for manufacturing a glass substrate according to claim 1, wherein the glass original plate for which one of the monitoring values is to be calculated has been determined to be non-defective in the original plate determination step within a predetermined time. ..
When the monitored value exceeds a preset upper limit value, the judgment criterion is tightened,
The method for manufacturing a glass substrate according to claim 1, wherein the determination criterion is loosened when the monitored value is less than a preset lower limit value.
Prior to the lot forming step, a distribution step of distributing the glass original plate determined to be non-defective in the original plate determination step to a plurality of take-out devices,
In the lot forming step, each of the plurality of take-out devices forms the lot,
The lot formed by the plurality of take-out devices includes the lots having different cutting patterns of the glass substrate from the glass original plate,
In the sorting step, the glass original plate is sorted into the take-out device that forms the lot having the cut-out pattern that is not located in the region where the rejected defect is the glass substrate. The method for manufacturing a glass substrate according to any one of 1.
An average value of the number of the passing defects per one glass original plate for one lot is calculated as a lot determination value, and the pass/fail of the lot is determined based on the lot determination value. Item 5. A method for manufacturing a glass substrate according to any one of Items 1 to 4.
The glass according to claim 5, wherein the number of the glass original plates for which one of the lot determination values is calculated is larger than the number of the glass original plates for which one of the monitoring values is calculated. Substrate manufacturing method.
The method for manufacturing a glass substrate according to any one of claims 1 to 6, wherein the criterion is the size of a defect.