WO2011083605A1

WO2011083605A1 - Blast machining method and blast machining device

Info

Publication number: WO2011083605A1
Application number: PCT/JP2010/068042
Authority: WO
Inventors: 武徳吉澤; 和樹小林
Original assignee: シャープ株式会社
Priority date: 2010-01-07
Filing date: 2010-10-14
Publication date: 2011-07-14

Abstract

Provided is a blast machining method or the like having high machining accuracy. The disclosed blast machining method is for forming a recess (9) in the surface of an object being machined (8) so as to conform with a target recess of a predetermined shape by blasting a blast material (21) onto the surface of the object, the method involving: a step of denting the surface of the object by blasting the blast material (21) onto the same in order to form a provisional recess (91) smaller and shallower than the target recess; a step of removing foreign substances in the provisional recess (91) by blowing a gas toward the provisional recess; a step of measuring the depth of the provisional recess (91) in a manner so as to trace the inner-surface shape of the provisional recess (91); a step of determining the target distance by which the provisional recess (91) is to be further dented, the determination being made based on the depth of the predetermined target recess and the result of measuring the depth of the provisional recess (91); and a step of further denting the provisional recess (91) by blasting the blast material (21) in accordance with the target distance.

Description

Blasting method and blasting apparatus

The present invention relates to a blasting method and a blasting apparatus for injecting an injection material to dig up a workpiece.

The liquid crystal display panel has a pair of glass substrates facing each other with a liquid crystal layer interposed therebetween. This glass substrate is manufactured by appropriately laminating a thin film transistor, a color filter layer, an electrode and the like on a glass plate. The glass plate used for the glass substrate is manufactured by a known manufacturing method such as a float method, a fusion method, or a drawdown method.

The glass plate obtained by such a manufacturing method may contain bubbles. These bubbles are trapped and trapped in the glass plate during the manufacturing process of the glass plate, and cause cavities in the glass plate or depressions on the surface of the glass plate. When such a glass plate containing bubbles is used as it is in a liquid crystal display panel, display defects such as bright spots occur in the liquid crystal display panel. In addition to bubbles, foreign substances (for example, refractory brick fragments) may be mixed in the glass plate during the glass plate manufacturing process. Even when such a glass plate containing foreign matter is used as it is in a liquid crystal display panel, display defects such as black spots occur in the liquid crystal display panel.

For this reason, conventionally, for the purpose of preventing display defects of the liquid crystal display panel, an operation of scraping bubbles or foreign matters from the glass plate has been performed. A concave portion is formed in the glass plate after scraping off bubbles and the like by such work. The concave portion is filled with a transparent material such as acrylic resin, and the surface of the glass plate is restored to its original shape.

It is desirable to remove such bubbles in the glass plate before assembling the glass substrate from the viewpoint of work efficiency. However, bubbles and the like that cause display defects are very small and may be overlooked when inspecting a glass plate (mother glass). For this reason, after assembling the glass substrate, an operation of removing bubbles or the like in the glass plate may be performed.

In recent years, blasting such as sand blasting has been used for the removal work. Blasting is a process in which a powdery abrasive material (injection material) is sprayed with the assistance of compressed air to scrape a workpiece such as a glass plate. This blasting process is preferably used because the processing heat can be kept relatively low. In addition, it has advantages such as easy removal of bubbles and the like compared to conventional drilling and the like.

Note that, as technical documents related to the present application, for example, Patent Documents 1 to 3 are cited.

JP-A-8-25148 Special table 2009-505843 JP-A-4-289649

Blasting uses a fluid discontinuous powdery injection material, so that there is a problem that the amount of processing is very easy to vary and its control is difficult. In particular, the spray material is easily affected by humidity (humidity), and the processing amount such as depth and size (shape) may change greatly even if the processing object is of the same type when the humidity changes. It has become.

As shown in

Patent Documents

1 and 2, in conventional processing methods other than blasting for forming a recess in a workpiece, the processing conditions are corrected during processing or before performing the next processing. By doing so, the amount of processing is controlled.

For example, Patent Document 1 discloses die-sinking electric discharge machining that first performs rough machining under predetermined conditions, and then performs machining by switching the machining conditions. In this technique, when the machining conditions are switched, the roughness of the machined surface is predicted from the machining conditions used in the rough machining, and the machining conditions for the finishing machining are determined using the prediction result.

Further, Patent Document 2 discloses a technique for performing fine processing such as holes on a processing target using a laser beam. In this technique, variation in laser output is grasped by monitoring laser parameters such as the number of pulses and pulse shape. By correcting these laser parameters, variations in laser output are suppressed and processing accuracy is improved.

However, it is difficult to control the amount of blasting even if such a technique is diverted. This is because, as described above, since blasting uses a powdered injection material that is discontinuous, fluid, and susceptible to humidity, it is very important to specify the processing result with the processing parameters. Because it is difficult. In blasting, it is virtually impossible to correct machining conditions without knowing the actual machining amount.

Patent Document 3 discloses a technique for grasping a processing amount (processing depth) using reflected light of a laser irradiated on a processing surface and interference light between a reference laser and the like. .

However, even if such a technique is used, it is difficult to accurately grasp the actual processing amount (processing depth) by blast processing. This is because the concave portion formed by blasting has a concave and convex shape with an inner surface having a complicated gradient. Therefore, even if only the processing depth at a specific location is measured using the above-described conventional technology, the concave portion is complicated. This is because it is difficult to grasp the inner surface shape.

An object of the present invention is to form a temporary recess in a workpiece by spraying an injection material so that the bottom is smaller than the target recess and shallow, and the measurement result of the depth of the temporary recess and a predetermined target recess A blasting method or the like is provided that injects an injection material in accordance with a target distance determined on the basis of the depth of the material and further digs the temporary recesses.

The blasting method according to the present invention is as follows.
<1> A blasting method of injecting an injection material toward the surface of a workpiece and forming a recess according to a target recess having a predetermined shape on the surface,
A first injection step of injecting the injection material toward the surface of the workpiece and digging the surface in order to form a temporary recess that is smaller than the target recess and shallow at the bottom;
A first foreign matter removing step of blowing gas toward the temporary concave portion to remove foreign matters in the temporary concave portion;
A first measurement step of measuring the depth of the temporary recess so as to copy the shape of the inner surface of the temporary recess from which foreign matter has been removed;
A determination step of determining a target distance for further digging the temporary recess, based on a predetermined depth of the target recess and a measurement result of the depth of the temporary recess;
A blasting method comprising: a second injection step of injecting the injection material according to the determined target distance to further dig up the temporary recess.

<2> The blasting method according to <1>, wherein, in the determining step, a target distance for further digging the temporary recess is determined based on a difference between a depth of the target recess and a depth of the deepest portion of the temporary recess.

<3> The blasting method according to <1>, wherein in the determining step, a target distance for further digging the temporary recess is determined based on a difference between the depth of the target recess and the average depth of the temporary recess.

<4> The blasting according to any one of <1> to <3>, wherein in the second injection step, the injection material is injected at an injection speed and an injection time corresponding to the target distance determined in the determination step. Law.

<5> In any one of the above items <1> to <4>, in the first measurement step, the depth of the temporary recess is measured so as to copy the shape of the inner surface of the temporary recess using a confocal scanning sensor. The blasting method described.

<6> a second foreign matter removing step of blowing gas toward the concave portion formed after digging up the temporary concave portion and removing the foreign matter in the concave portion;
A second measuring step for measuring the depth of the concave portion so as to copy the shape of the inner surface of the concave portion from which the foreign matter has been removed by the second foreign matter removing step;
Any one of the above items <1> to <5>, further comprising a detection step of detecting a defective recess based on the depth of the target recess and the measurement result of the depth of the recess measured in the second measurement step. Blasting method described in one.

<7> The blasting method according to <6>, wherein in the second measurement step, the depth of the concave portion is measured so as to copy the shape of the inner surface of the concave portion using a confocal scanning sensor.

<8> The blasting method according to any one of <1> to <7>, wherein the object to be processed is a glass substrate for a liquid crystal display panel.

<9> A blasting apparatus for forming a recess according to a target recess having a predetermined shape on the surface of a workpiece,
A stage on which the workpiece is placed;
A blast nozzle that injects an injection material toward the surface of the workpiece on the stage, digs up the surface, and forms a temporary recess that is smaller than the target recess and has a shallow bottom on the surface;
An air nozzle that blows gas toward the temporary recess and removes foreign matter in the temporary recess;
Measuring means for measuring the depth of the temporary recess so as to copy the shape of the inner surface of the temporary recess from which foreign matter has been removed;
Determining means for determining a target distance for further digging the temporary recess, based on a predetermined depth of the target recess and a measurement result of the depth of the temporary recess;
The blast processing apparatus, wherein the blast nozzle sprays the spray material according to the target distance to further dig up the temporary recess.

<10> The blasting apparatus according to <9>, wherein the determining unit determines a target distance for further digging the temporary recess based on a difference between a depth of the target recess and a depth of the deepest portion of the temporary recess.

<11> The blasting apparatus according to <9>, wherein the determining unit determines a target distance for further digging the temporary recess based on a difference between a depth of the target recess and an average depth of the temporary recess.

<12> The blasting apparatus according to any one of <9> to <11>, wherein the blast nozzle injects the injection material at an injection speed and an injection time corresponding to the target distance determined by the determining unit.

<13> The blasting apparatus according to any one of <9> to <12>, wherein the measurement unit is a confocal scanning sensor.

<14> The air nozzle blows gas toward the recess formed after the temporary recess is dug down, and removes foreign matter in the recess.
The measuring means measures the depth of the recess so as to copy the inner surface shape of the recess from which foreign matter has been removed,
The blasting apparatus according to any one of <9> to <13>, further comprising detection means for detecting a defective recess based on a depth of the target recess and a measurement result of the depth of the recess.

<15> The blasting apparatus according to any one of <9> to <14>, wherein the object to be processed is a glass substrate for a liquid crystal display panel.

According to the blasting method or the like of the present invention, the injection material is injected so that the bottom is shallower than the target recess and the temporary recess is formed in the workpiece, and the measurement result of the depth of the temporary recess is determined in advance. Since the injection material is injected according to the target distance determined based on the depth of the target recess, and the temporary recess is further dug down, the processing accuracy of the recess can be increased.

It is explanatory drawing which represented typically the structure of the blast processing apparatus which concerns on one Embodiment. It is explanatory drawing which represented the structure of the measuring apparatus typically. It is explanatory drawing which represented the content of each process of the blast processing method typically. It is explanatory drawing which shows the procedure of the blast processing method shown by FIG. It is explanatory drawing which represented typically the measurement result of the depth of the temporary recessed part measured by scanning a measuring apparatus continuously. It is explanatory drawing which represented typically the cross section of the recessed part deeper than a target recessed part. It is explanatory drawing which represented the cross section of the temporary recessed part typically. It is explanatory drawing which represented the cross section of the other temporary recessed part typically. It is explanatory drawing which represented typically each process of the blasting method for adding a process further to the recessed part formed on the glass substrate. It is explanatory drawing which shows the procedure of the blast processing method shown by FIG. It is explanatory drawing which represented typically the cross section of the recessed part formed in the glass substrate. It is explanatory drawing which represented typically the cross section of the defect recessed part formed in the glass substrate. It is explanatory drawing which represented typically the cross section of the other defect recessed part formed in the glass substrate.

Hereinafter, a blasting method and a blasting apparatus according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments exemplified in this specification.

[First Embodiment]
FIG. 1 is an explanatory diagram schematically illustrating the configuration of a blasting apparatus 1 according to an embodiment. As shown in FIG. 1, the blasting apparatus 1 includes a blast nozzle 2, an air nozzle 3, a measuring device 4, a scanning device 5, a control device 6, and a stage 7. This blast processing apparatus 1 uses a sand blast processing technique to scrape bubbles contained in a glass plate of a glass substrate 8 for a liquid crystal display panel and form a recess in the glass substrate 8.

The blast nozzle 2 is a device that injects a powdery injection material (abrasive) on a compressed air stream. The blast nozzle 2 includes an injection material hopper (not shown) for supplying a predetermined amount of the injection material to the blast nozzle 2 and a compressed air supply device (not shown) for supplying compressed air to the blast nozzle 2 at a predetermined pressure. ) Etc. are connected. The injection material supplied to the blast nozzle 2 is mixed with compressed air inside and injected from the blast nozzle 2. The supply amount of the injection material to the blast nozzle 2 and the pressure of the compressed air supplied to the blast nozzle 2 are controlled by the control device 6.

The blast nozzle 2 has a valve (not shown) in its interior, and by controlling the opening and closing of the valve by the control device 6, injection and stop of the blast nozzle 2 are switched. In the present embodiment, the injection speed of the injection material injected from the blast nozzle 2 depends on the supply amount per unit time of the injection material supplied to the blast nozzle 2 and the compressed air supplied to the blast nozzle 2. It is determined by the supply pressure per unit time.

The blast nozzle 2 is arranged so that the spray material can be sprayed toward the surface of the glass substrate 8 placed on the upper surface of the stage 7. The glass substrate 8 is fixed and positioned on a stage 7 equipped with a suction holding device (not shown), and even if the spray material is sprayed from the blast nozzle 2, the glass substrate 8 does not move and does not shift its position. The blast nozzle 2 is supported above the stage 7 by the arm-shaped scanning device 5 and is configured to be able to freely move in the horizontal direction with respect to the glass substrate 8 on the stage 7 and to be stopped. In addition, a well-known thing can be employ | adopted as a drive mechanism of the scanning apparatus 5, The operation | movement is controlled by the control apparatus 6. FIG.

The air nozzle 3 is a device for blowing off foreign matter made of waste (glass waste), used spray material, etc. on the glass substrate 8 with air (compressed air). This air nozzle 3 is used in particular to remove foreign substances in a recess (concave portion) on the glass substrate 8 formed using the blast nozzle 2. The air nozzle 3 is connected to a compressed air supply device (not shown) so that compressed air can be supplied to the air nozzle 3 at a predetermined pressure. A valve (not shown) is provided inside the air nozzle 3, and the air injection and stop of the air nozzle 3 are switched by controlling the opening and closing of the valve by the control device 6.

As with the blast nozzle 2, the air nozzle 3 is supported above the stage 7 by the scanning device 5, and can move freely in the horizontal direction with respect to the glass substrate 8 on the stage 7 and can be stopped. .

The measuring device 4 is a device that measures the depth of the recess formed in the glass substrate 8. The measuring device 4 is composed of, for example, a confocal scanning type sensor, and can scan three-dimensionally the depth in the recess by scanning the inner surface shape of the recess.

Here, the configuration and operation of the measuring apparatus 4 will be described in detail with reference to FIG. FIG. 2 is an explanatory diagram schematically showing the configuration of the measuring device 4. This measuring device 4 is known as a so-called confocal scanning sensor. As shown in FIG. 2, the measuring device 4 includes a semiconductor laser 41 disposed above and used as a light source, and a half mirror 42 disposed at a predetermined angle below the semiconductor laser 41. The measuring device 4 includes a collimator lens 43 disposed below the half mirror 42, an objective lens 44 disposed below the collimator lens 43 so as to face the collimator lens 43, and a tuning fork 45 that supports the objective lens 44, A position sensor 46 for detecting the position of the tuning fork 45 is provided. Further, the measuring device 4 includes a pinhole 47 disposed in the lateral direction of the half mirror 42 and a light receiving element 48.

When the measuring device 4 measures the depth of the recess 9, a laser beam 401 is emitted from the semiconductor laser 41. Then, the laser light 401 is converted into parallel light by the collimating lens 43 and passes through the objective lens 44 that is moving at high speed in the vertical direction by the tuning fork 45. When the position of the focal point (measurement spot) 403 of the light 402 that has passed through the objective lens 44 coincides with the position of the surface of the concave portion 9 of the glass substrate 8 that is the measurement object, the light 402 is strongly reflected by the surface of the concave portion 9. . The reflected light 404 at that time passes through the half mirror 42 and is further condensed at one point at the position of the pinhole 47 by the confocal principle, so that it passes through the pinhole 47 and is received by the light receiving element 48. The The position sensor 46 is configured to measure the position (height from the glass substrate 8) when the light receiving element 48 receives light. Based on the measurement result of the position sensor 46, the depth of the recess 9 can be accurately grasped. The signals output from the light receiving element 48 and the position sensor 46 are transmitted to the control device 6 that is electrically connected to the measuring device 4.

The measuring device 4 is supported by the scanning device 5 as shown in FIG. By appropriately moving the scanning device 5 in the horizontal direction (parallel) with respect to the glass substrate 8, the position of the focal point (measurement spot) 403 of the light irradiated from the semiconductor laser 41 shown in FIG. It can be moved so as to trace the inner surface shape. Thus, by measuring the depth in the recess 9 by scanning the measuring device 4 and continuously measuring the depth in the recess 9, it consists of depth data at a plurality of locations in the recess 9. Three-dimensional recess depth data can be acquired. The measurement result of the measuring device 4 is transmitted to the control device 6. The measuring operation of the measuring device 4 is controlled by the control device 6.

If this measuring device 4 is used, the depth in the recess can be measured without problems even if the machining surface in the recess is inclined. Further, the measuring device 4 can measure the depth in the recess without any problem even on a processed surface that is difficult to grasp with a conventional measuring device (particularly when a transparent material such as glass is mirror-finished).

As shown in FIG. 1, the control device 6 includes a CPU (Central Processing Unit) 61, a ROM (Read Only Memory) 62, a RAM (Random Access Memory) 63, an input unit 64, an instruction unit 65, a display. The configuration includes a unit 66, an acquisition unit 67, a storage unit 68, and the like. Each configuration is configured such that data can be exchanged with each other via the data bus 69.

The CPU 61 is a device that executes arithmetic processing for operation control of the blasting apparatus 1. The ROM 62 stores various programs and various menus for controlling the operation of the blasting apparatus 1 in advance. The RAM 63 is configured by SRAM, flash memory, or the like. The CPU 61 executes the control program in the ROM 62 while using the RAM 63 as a work area. Therefore, data generated when the control program is executed is temporarily stored in the RAM 63.

The acquisition unit 67 is connected to the CPU 61 via the data bus 69 and is also connected to the measurement device 4. The output data (measurement result) from the measurement device 4 is converted from analog to digital and stored in the storage unit 68. To do. The measuring device 4 is set to measure the depth of the concave portion of the glass substrate 8 by receiving a concave portion measurement instruction signal from the CPU 61 of the control device 6 via the acquisition unit 67.

The storage unit 68 includes an HDD (hard disk drive) or the like, and stores and stores data (measurement results) acquired by the acquisition unit 67 from the measurement device 4 based on the control of the CPU 61. Note that the shape data (depth data) of a target recess, which will be described later, and the like are also stored in the storage unit 68.

The display unit 66 is composed of a CRT, LCD, or the like, and displays the operating state of the blasting apparatus 1 and various menus stored in the ROM 62.

The input unit 64 includes a keyboard and a mouse, and an operator operates the blasting apparatus 1 using the input unit 64 according to the display content of the display unit 66. Various instruction information input from the input unit 64 by the operator is stored in the RAM 63 under the control of the CPU 61.

The instruction unit 65 is connected to the blast nozzle 2 together with the CPU 61 via the data bus 69, and outputs an instruction signal for injection of the blast nozzle 2 based on the control of the CPU 61. The instruction unit 65 is set to output various instruction signals to the air nozzle 3, the scanning device 5, and the like in addition to the blast nozzle 2 based on the control of the CPU 61.

Next, a blasting method using the blasting apparatus 1 will be described with reference to FIGS. 3 and 4 together with FIGS. FIG. 3 is an explanatory view schematically showing the contents of each step of the blasting method. FIG. 3A is an explanatory view schematically showing a state in which a glass substrate containing bubbles is arranged at a predetermined position, and FIG. 3B is a step of forming a temporary recess in the glass substrate by injecting an injection material from a blast nozzle. FIG. 3C is an explanatory diagram schematically showing a process of removing the foreign matter in the temporary recess by blowing it off with air, and FIG. 3D is a diagram showing the temporary recess by scanning the measuring device. It is explanatory drawing which represented typically the process of measuring the depth of FIG. 3, FIG. 3E is explanatory drawing which represented typically the process of injecting an injection material from a blast nozzle and further digging a temporary recessed part. FIG. 4 is an explanatory diagram showing a procedure of the blasting method shown in FIG.

As shown in FIG. 3A, the glass substrate 8 transported by a transport means (not shown) is disposed at a predetermined position. The glass substrate (glass plate) 8 includes bubbles 81 formed in the manufacturing process. The thickness of this glass substrate 8 (thickness of the glass plate portion) is assumed to be 0.7 mm. In order to scrape the bubbles 81 from the glass substrate 8, the surface of the glass substrate 8 is dug down to a depth (depth of the deepest portion) of 0.5 mm by using the blast processing apparatus 1 shown in FIG. A recess is formed in Note that the storage unit 68 included in the control device 6 of the blast processing apparatus 1 stores in advance shape data of a target recess that is a target when the recess is formed in the glass substrate 8. This shape data includes information related to the depth of the target recess (depth of the deepest portion), and further includes other data such as the area of the opening of the target recess as necessary.

<First injection process>
As shown in FIG. 3B, the spray material 21 is sprayed from the blast nozzle 2 toward the glass substrate 8 disposed at a predetermined position under the first spraying condition to form a temporary recess 91 in the glass substrate 8. (See S1 in FIG. 4). This first injection condition is determined based on experience according to the depth of the target recess formed in the glass substrate 8 (depth of the deepest portion: D = 0.5 mm). The first injection condition is a processing condition for forming the temporary recess 91 that is smaller than the target recess and has a shallow bottom. That is, it is necessary to set the first injection condition so that the depth of the temporary recess 91 is smaller than the depth of the target recess (depth D of the deepest portion). In the first injection condition of the present embodiment, the injection speed of the injection material from the blast nozzle 2 is v (constant), and the injection time (processing time) is T1. Various conditions such as the type of spray material, the diameter of the blast nozzle 2 and the distance between the tip of the blast nozzle 2 and the surface of the glass substrate 8 are appropriately set according to the purpose. Under such first injection conditions, when the injection material 21 is injected from the blast nozzle 2 toward the glass substrate 8, a temporary recess 91 is formed as shown in FIG. 3B. Note that the blast nozzle 2 is retracted from above the temporary recess 91 after the first injection step. In blasting, the depth in the temporary recess cannot be measured during processing. For this reason, the injection from the injection blast nozzle 2 is temporarily stopped to stop the blasting process. The bubbles 81 in the glass substrate 8 are sufficiently thin with respect to the thickness of the glass substrate 8. Therefore, it is considered that the processing amount of the glass substrate 8 in the first injection process is not affected by the presence of the bubbles 81.

<First foreign matter removing step>
In the temporary recess 91 after the first injection step, there are usually foreign matters such as scraps (glass scraps) from which the glass substrate 8 has been cut and used sprays. If the foreign object remains in the temporary recess 91, it is difficult to accurately measure the depth of the temporary recess 91 by the measuring device 4. Therefore, as shown in FIG. 3C, the air nozzle 3 is disposed above the temporary recess 91, and air (compressed air) 31 is blown from the air nozzle 3 toward the temporary recess 91 of the glass substrate 8. The foreign matter inside is blown off and removed (see S2 in FIG. 4). Note that the air nozzle 3 moves away from above the temporary recess 91 after the first foreign matter removing step.

<First measurement process>
As shown in FIG. 3D, the measuring device 4 is disposed above the temporary recess 91 from which foreign matter has been removed, and the measuring device 4 is scanned in the horizontal direction with respect to the glass substrate 8 to determine the depth of the temporary recess 91. Get the data. The measuring device 4 measures the depth of the temporary recess 91 while repeatedly reciprocating above the temporary recess 91 so as to copy the shape of the inner surface of the temporary recess 91. Based on the depth data of the temporary recess 91 measured in this way, the inner surface shape of the temporary recess 91 can be grasped three-dimensionally (see S3 in FIG. 4).

In the present embodiment, the depth d of the deepest portion (the deepest portion) of the temporary recess 91 is determined based on the control of the CPU 61 in the control device 6 using the depth data of the temporary recess 91 (FIG. 4 S4).

FIG. 5 is an explanatory view schematically showing a measurement result of the depth of the temporary recesses continuously measured by scanning the measuring device. In FIG. 5, a cross section of the temporary recess 91 formed in the glass substrate 8 is indicated by a solid line. Further, in FIG. 5, a virtual cross section of the target concave portion 90 is shown with a broken line together with a cross section of the temporary concave portion 91. When the measuring device crosses over the temporary recess 91, the measurement spot (focal point) of the measuring device moves so as to trace the surface of the temporary recess 91. During this movement, the depths d1 to d5 of the temporary recess 91 at each measurement point are measured. FIG. 5 shows five depths d1 to d5 for convenience of explanation. The measurement interval is appropriately set according to the purpose. For example, in the cross section of the temporary recess 91 shown in FIG. 5, it is determined that the depth d3 is the largest. Note that the measuring apparatus continuously measures the depth of the temporary recess 91 in a cross section different from the cross section of the temporary recess 91 shown in FIG. The depth d of the deepest part is determined from all the depth data of the temporary recesses 91 thus measured.

As described above, based on the determined depth d of the deepest portion of the temporary recess 91, a target distance (additional processing amount) for further digging the temporary recess 91 is determined, and further, processing conditions ( (Second injection condition) is determined. In the present embodiment, the difference (D−d) between the depth D of the deepest portion of the target recess 90 and the depth d of the determined deepest portion of the temporary recess 91 is taken, and this difference (D−d) The target distance is used. Then, the second injection condition is determined using this target distance.

In short, the blasting method of the present embodiment is to adjust the processing conditions by grasping the remaining processing amount using the target distance (feedback) during the processing.

For example, when the injection speed of the blast nozzle 2 in the second injection process is set to v (constant speed) as in the first injection process, the remaining injection time T2 in the second injection process (addition process) is T2 = T1 (Dd) / d (see S6 in FIG. 4).

The first injection condition in the first injection step is set so that the depth d of the deepest portion of the temporary recess 91 is smaller than the depth D of the deepest portion of the target recess. Therefore, normally, the depth d of the deepest portion of the temporary recess 91 does not exceed the depth D of the deepest portion of the target recess 91. However, it is also conceivable that the depth d of the deepest portion of the temporary recess 91 is greater than or equal to the depth D of the deepest portion of the target recess 90 due to the influence of humidity or the like. FIG. 6 is an explanatory view schematically showing a cross section of a recess deeper than the target recess. As shown in FIG. 6, depending on the processing conditions, a recess 91A (depth d11> D) deeper than the deepest depth D of the target recess is already formed in the glass substrate 8 in the first injection step. It is also possible. If such a recess 91 A is further dug down in the second spraying step, a through hole is formed in the glass substrate 8, which causes damage to the glass substrate 8. Therefore, in this embodiment, before determining the second injection condition, the case where the depth d of the deepest portion of the temporary recess 91 is equal to or greater than the depth D of the deepest portion of the target recess is eliminated, and the temporary recess 91 is removed. Further, it is not dug down (see S5 in FIG. 4).

<Second injection process>
As shown in FIG. 3E, when the injection material 21 is injected from the blast nozzle 2 toward the temporary recesses under the second injection condition, the temporary recesses are dug down, and the recesses 9 having a shape approximate to the shape of the target recesses are formed. It is formed on the glass substrate 8 (see S7 in FIG. 4).

As described above, when the glass substrate 8 is processed using the blast nozzle 2 by the procedure shown in FIGS. 3 and 4, the concave portion 9 having a predetermined shape can be obtained with high accuracy. And when the several recessed part 9 is formed with respect to the glass substrate 8 of 1 sheet, or the glass substrate 8 of several sheets, the dispersion | variation in the shape (size) of each recessed part 9 can be suppressed.

Hereinafter, blasting apparatuses and blasting methods according to other embodiments will be described.
[Second Embodiment]
In the above embodiment, as shown in FIG. 5 and the like, the depth d of the deepest portion of the temporary recess 91 is determined based on the depth data of the temporary recess 91 acquired by the measuring device, and the depth of this deepest portion is determined. However, in other embodiments, the present invention is not limited to this. For example, the second injection condition may be determined using an average value of the depth of the temporary recesses. FIG. 7 is an explanatory view schematically showing a cross section of the temporary recess 91. FIG. 7 shows the depths d21 to d25 of the temporary recess 91 measured by the measuring device within the specific range x1 of the central portion. As shown in FIG. 7, a specific range x1 in the temporary recess 91 is appropriately determined, and the average value dx of the temporary recess depth based on the depths d21 to d25 and the like at all the measurement points in the range x1. You may ask for. By using this average value dx, a difference (D−dx) from the depth D of the deepest part of the target recess may be obtained. Then, the second injection condition may be determined using this difference (D−dx).

FIG. 8 is an explanatory view schematically showing a cross section of another temporary recess. The temporary recess 91 B shown in FIG. 8 is raised at the center, and the periphery thereof is recessed. If a hard foreign material or the like is present in the glass substrate 8, the foreign material acts to protect the glass substrate 8 from the spray material sprayed toward the glass substrate 8, and the air flow of the spray material is disturbed. it is conceivable that. In such a case, the lower part of the foreign material remains relatively uncut and a temporary recess 91B having a shape as shown in FIG. 8 is formed. In addition to such a case, a temporary recess 91B as shown in FIG. 8 may be formed. For the temporary concave portion 91B having such a complicated inner surface shape, for example, a specific range x2 including the central portion is appropriately determined in the temporary concave portion 91B, and the depth d31 at all measurement points in the range x2 is determined. Based on ˜d39 and the like, the average depth dx of the temporary recess 91B may be obtained. Using this average value dx, a difference (D−dx) from the depth D of the deepest part of the target recess is obtained, and the second injection condition is determined using this difference (D−dx). good.

[Third Embodiment]
When the second injection condition is determined using the difference (D−d) obtained based on the depth D of the deepest portion of the target recess and the depth d of the temporary recess, for example, the difference (D− You may utilize the injection condition table which shows relations, such as injection speed and injection time, corresponding to d). In this injection condition table, in order to correspond to the difference, the relationship between the injection speed and the injection time is determined in advance based on experimental data and the like. 68 is stored in advance. The injection condition table is referred to under the control of the CPU 61 when the second injection condition is determined using the difference. For example, when the injection condition vx and the injection time Tx are determined in advance in the injection condition table so as to correspond to the difference (D−d), the second injection condition is the injection condition vx and the injection time Tx. Will be selected.

[Fourth Embodiment]
Using the blast processing apparatus 1 shown in FIG. 1 and the like, as shown in FIG. 3E, the post-processing may be further performed on the concave portion 9 formed on the glass substrate 8. FIG. 9 is an explanatory view schematically showing each step of the blasting method for further processing the recess 9 formed on the glass substrate 8, and FIG. 9F blows off the foreign matter in the recess with air. FIG. 9G is an explanatory diagram schematically showing a step of measuring the depth of the concave portion by scanning the measuring device. FIG. 10 is an explanatory view showing the procedure of the blasting method shown in FIG.

<Second foreign matter removing step>
In FIG. 9F, the glass substrate 8 after the second injection step shown in FIG. 3E is arranged. In the concave portion 9 formed on the glass substrate 8, there are usually foreign matters such as glass scraps and spray materials. Therefore, in this step, the air nozzle 3 is used again to blow the air 31 to the recess 9 to blow away the foreign matter in the recess 9 (see S8 in FIG. 10).

<Second measurement process>
As shown in FIG. 9G, the depth of the concave portion 9 is measured by causing the measuring device 4 to scan the concave portion 9 after removing the foreign matter. The measurement step here is the same as the first measurement step except that the measurement object is different. Also in the second measuring step, the measuring device 4 scans the inner surface shape of the concave portion 9 to measure the depth of the concave portion 9 (see S9 in FIG. 10).

FIG. 11 is an explanatory diagram schematically showing a cross section of the recess 9 formed in the glass substrate 8. FIG. 12 is an explanatory view schematically showing a cross section of the defect recess 9 A formed in the glass substrate 8. FIG. 13 is an explanatory view schematically showing a cross section of another defective recess 9 B formed in the glass substrate 8. In FIGS. 11 to 13, virtual cross sections of the target recesses 90 each having the deepest portion having a depth D are overlapped so as to correspond to the cross sections of the respective recesses. If the blasting method and the blasting apparatus of the present invention are used, the concave portion 9 having a shape close to the shape of the target concave portion as shown in FIG. 11 is usually formed. However, when the humidity changes abruptly, it is conceivable that a defective recess as shown in FIG. 12 or 13 is formed.

The defect recess 9 A shown in FIG. 12 is deeper than the target recess 90. The defect concave portion 9A is formed because the central portion is raised, and foreign matter or the like is present in the glass substrate 8 as in the temporary concave portion shown in FIG. Such a defective recess 9A formed by being dug deeper than planned causes damage to the glass substrate 8 and needs to be detected.

The depth (depth of the deepest portion) of the defect concave portion 9B shown in FIG. 13 does not exceed the depth of the target concave portion (depth D of the deepest portion), but the size (volume) is the target. It is considerably smaller than the recess. By the way, if the size of the recesses formed in the glass substrate 8 varies, for example, the amount of resin filled for repairing the recesses becomes irregular and the workability deteriorates. Due to such circumstances, there is a case where it is desired to keep the shape (size) of the concave portion constant. In such a case, it is necessary to detect a defective recess 9B whose shape is smaller than planned as shown in FIG.

In order to discriminate between the normal concave portion 9 (see FIG. 11) approximate to the shape of the target concave portion 90 and the defective

concave portions

9A and 9B, the depth data of the concave portion measured in the second measurement step is determined in advance. The depth data of the target concave portion may be compared, and the defective concave portion may be detected based on the comparison result.

When detecting the concave portion shown in FIG. 12, for example, the difference (D−d41) between the depth d41 of the deepest portion in the specific cross section of the concave portion and the depth D of the deepest portion of the target concave portion is taken. The defect of the recess may be detected by comparing (D-d41) with a predetermined allowable value. The method for determining the depth d41 of the deepest part is the same as the method for determining the depth of the deepest part in the temporary recess.

As the depth data of the target recess 90, not only the depth data (depth D) of the deepest portion but also other portion depth data may be used (for example, the target recess shown in FIG. 13). 90 depth Dx). For example, a difference is taken between a plurality of depth data in a specific cross section of the recess and a plurality of predetermined depth data in a cross section of the target recess corresponding to the specific cross section of the recess. When the allowable value is exceeded, the concave portion may be determined as a defective concave portion. For example, in the case of the recess 9B shown in FIG. 13, one of the plurality of depth data in the specific cross section of the recess 9B is d51, and one of the predetermined plurality of depth data is Let Dx. In this case, when the difference (Dx−d51) exceeds a predetermined allowable value, it is determined that the recess 9B is a defective recess.

Claims

A blasting method in which a spray material is sprayed toward the surface of an object to be processed, and a recess is formed in accordance with a target recess having a predetermined shape on the surface,
A first injection step of injecting the injection material toward the surface of the workpiece and digging the surface in order to form a temporary recess that is smaller than the target recess and shallow at the bottom;
A first foreign matter removing step of blowing gas toward the temporary concave portion to remove foreign matters in the temporary concave portion;
A first measurement step of measuring the depth of the temporary recess so as to copy the shape of the inner surface of the temporary recess from which foreign matter has been removed;
A determination step of determining a target distance for further digging the temporary recess, based on a predetermined depth of the target recess and a measurement result of the depth of the temporary recess;
A blasting method comprising: a second injection step of injecting the injection material according to the determined target distance to further dig up the temporary recess.
The blasting method according to claim 1, wherein, in the determining step, a target distance for further digging the temporary recess is determined based on a difference between a depth of the target recess and a depth at the deepest portion of the temporary recess.
The blasting method according to claim 1, wherein, in the determining step, a target distance for further digging the temporary recess is determined based on a difference between a depth of the target recess and an average depth of the temporary recess.
The blasting method according to any one of claims 1 to 3, wherein in the second injection step, the injection material is injected at an injection speed and an injection time corresponding to the target distance determined in the determination step.
The blasting method according to any one of claims 1 to 4, wherein in the first measurement step, the depth of the temporary recess is measured using a confocal scanning sensor so as to copy the shape of the inner surface of the temporary recess.
A second foreign matter removing step of blowing gas toward the concave portion formed after digging down the temporary concave portion and removing the foreign matter in the concave portion;
A second measuring step for measuring the depth of the concave portion so as to copy the shape of the inner surface of the concave portion from which the foreign matter has been removed by the second foreign matter removing step;
The detection step of detecting a defective recess based on the depth of the target recess and the measurement result of the depth of the recess measured in the second measurement step, according to any one of claims 1 to 5. Blasting method.
The blasting method according to claim 6, wherein in the second measuring step, the depth of the concave portion is measured so as to copy the inner shape of the concave portion using a confocal scanning sensor.
The blasting method according to any one of claims 1 to 7, wherein the object to be processed is a glass substrate for a liquid crystal display panel.
A blasting apparatus for forming a recess according to a target recess having a predetermined shape on the surface of a workpiece,
A stage on which the workpiece is placed;
A blast nozzle that injects an injection material toward the surface of the workpiece on the stage, digs up the surface, and forms a temporary recess that is smaller than the target recess and has a shallow bottom on the surface;
An air nozzle that blows gas toward the temporary recess and removes foreign matter in the temporary recess;
Measuring means for measuring the depth of the temporary recess so as to copy the shape of the inner surface of the temporary recess from which foreign matter has been removed;
Determining means for determining a target distance for further digging the temporary recess, based on a predetermined depth of the target recess and a measurement result of the depth of the temporary recess;
The blast processing apparatus, wherein the blast nozzle sprays the spray material according to the target distance to further dig up the temporary recess.
10. The blast processing apparatus according to claim 9, wherein the determining means determines a target distance for further digging the temporary concave portion based on a difference between a depth of the target concave portion and a depth at the deepest portion of the temporary concave portion.
10. The blast processing apparatus according to claim 9, wherein the determining means determines a target distance for further digging the temporary recess based on a difference between the depth of the target recess and the average depth of the temporary recess.
The blasting apparatus according to any one of claims 9 to 11, wherein the blast nozzle injects the injection material at an injection speed and an injection time corresponding to the target distance determined by the determining means.
The blasting apparatus according to any one of claims 9 to 12, wherein the measuring means comprises a confocal scanning sensor.
The air nozzle blows gas toward the concave portion formed after digging the temporary concave portion, and removes foreign matter in the concave portion,
The measuring means measures the depth of the recess so as to copy the inner surface shape of the recess from which foreign matter has been removed,
The blasting apparatus according to any one of claims 9 to 13, further comprising detection means for detecting a defective recess based on a depth of the target recess and a measurement result of the depth of the recess.
The blasting apparatus according to any one of claims 9 to 14, wherein the object to be processed is a glass substrate for a liquid crystal display panel.