Scribing method for bonded brittle substrates having terminals

Abstract

To provide a scribing method for a joined brittle substrate with a terminal part capable of preventing cracks of a terminal part and forming a correct scribe line.SOLUTION: A scribing method for a joined brittle substrate with a terminal part comprises: a section setting step (101) of dividing a scheduled traveling route of a scribe wheel (19) into a pre-cutting section (A), a normal cutting section (B) and a terminal cutting section (C); a wheel home position step (103); a pre-cutting section line formation step (105) of accelerating the scribe wheel (19) to a set speed; a normal cutting section line formation step (107); a deceleration step (109) of decelerating the traveling speed of the scribe wheel (19); and a terminal part cutting section line formation step (111) of forming a scribe line on a terminal part as being decelerated.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for processing brittle substrates for displays, and more particularly to a method for scribing bonded brittle substrates having terminal portions, which does not cause poor cutting of the terminal portions at the ends of the bonded brittle substrates. [Background technology]

[0002] Dicing and scribing are two typical methods for cutting thin, brittle substrates, including glass substrates, to the required size. Dicing involves cutting the surface of the substrate with a diamond blade to form grooves, while scribing involves forming scribe lines on the surface of the substrate with a scribing wheel to generate cracks in the thickness direction.

[0003] Furthermore, some products using brittle substrates use bonded brittle substrates. For example, a liquid crystal display panel has a structure in which a color filter is formed on one substrate and a TFT is formed on the other substrate, and liquid crystal is injected between the two substrates and bonded together.

[0004] However, since the bonded brittle substrate has a terminal portion 13a on one side of the substrate as shown in FIG. 1, if special care is not taken when cutting, the terminal portion may crack, making the bonded brittle substrate unusable.

[0005] FIG. 1 is a diagram for explaining the problems with the conventional scribing method for a bonded brittle substrate (10).

[0006] As shown in the figure, the bonded brittle substrate 10 has a laminated structure of a lower plate 15 and an upper plate 13. A terminal portion 13a is located at one end of the upper plate 13. The terminal portion 13a is suspended above the table T by the thickness of the lower plate 15.

[0007] To form a scribe line on the bonded brittle substrate (10) having the above structure, the scribe wheel (19) is positioned on one side of the upper part of the bonded brittle substrate (10), and the wheel is pushed downward and simultaneously moved in the direction of arrow a toward the terminal portion (13a).

[0008] However, this method has manufacturing problems because when the scribing wheel 19 runs over the terminal portion 13a, the terminal portion 13a may bend downward, causing cracks, or the scribe line may not be properly formed on the terminal portion 13a.

[0009] For this reason, Patent Document 1 discloses a scribing method and device for bonded substrates. The disclosed scribing method uses two opposing cutter wheels to scribe a bonded substrate in the direction of the terminal area, where a portion of the edge of a first substrate has been removed and a terminal area has been formed on the edge of a second substrate, thereby processing scribe lines for dividing the substrate on the top and bottom surfaces of the substrate. The method includes the steps of moving the second cutter wheel that scribes the second substrate having the terminal area along a running line parallel to the surface of the second substrate until it reaches the vicinity of the terminal area end position, then running the second cutter wheel gradually away from the surface of the terminal area from the vicinity of the terminal area end position to the terminal area end position, and instantly retracting the wheel from the terminal area with zero downtime upon reaching the terminal area end position. However, the technology disclosed in Patent Document 1 is insufficient in terms of obtaining a non-defective product. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent Publication No. 10-2019-0078494 Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been created to solve the above problems, and aims to provide a method for scribing a bonded brittle substrate having a terminal portion, which can form an accurate scribe line and prevent cracking of the terminal portion by controlling the cutting depth of the scribing wheel on the substrate, adjusting the load, and controlling the running speed. [Means for solving the problem]

[0012] The present invention provides a method for scribing a bonded brittle substrate having a terminal portion as a means for achieving the above object. The method forms a scribe line on a bonded brittle substrate having a terminal portion, and includes: a section setting step for dividing a planned travel path of a scribe wheel into a pre-cutting section, a main cutting section, and a terminal portion cutting section; a wheel positioning step for positioning the scribe wheel at the travel start point of the pre-cutting section; a pre-cutting section line forming step for pressing the scribe wheel positioned at the travel start point against the bonded brittle substrate and running it while accelerating until a set speed is reached; a main cutting section line forming step for running the scribe wheel at the set speed after passing the pre-cutting section to form a scribe line in the main cutting section; a deceleration step for decelerating the travel speed of the scribe wheel after passing the main cutting section before it reaches the terminal portion, so that the scribe wheel receives a control signal per unit time at a travel distance shorter than before deceleration; and a terminal portion cutting section line forming step for running the scribe wheel through the terminal portion cutting section at the travel speed reduced in the deceleration step to form a scribe line on the terminal portion.

[0013] The step of forming the line for the terminal portion cutting section includes the steps of storing the position of the scribe wheel immediately before entering the terminal portion, resetting the cutting depth in the cutting section to the cutting depth at the current position, and changing the cutting depth to be applied in the terminal portion cutting section to a target position based on the current position after resetting.

[0014] In addition, the average depth of cut imparted to the scribe wheel passing through the pre-cutting section and the terminal portion cutting section is equal to or less than the depth of cut imparted to the scribe wheel in the main cutting section.

[0015] The wheel load applied by the scribing wheel to the bonded brittle substrate in the terminal cutting section is relatively larger than the wheel load applied by the scribing wheel to the bonded brittle substrate in the main cutting section. [Effects of the Invention]

[0016] The scribing method for bonded brittle substrates having terminal portions according to the present invention, which is performed as described above, can form accurate scribe lines by controlling the cutting depth, load adjustment, and traveling speed of the scribe wheel on the substrate during the scribing process, and in particular, can prevent cracks in the terminal portions by changing the cutting depth in multiple stages. [Brief explanation of the drawings]

[0017] [Figure 1] 1A and 1B are diagrams for explaining problems with a conventional scribing method for bonded brittle substrates. [Figure 2] 1 is a block diagram illustrating a scribing method according to an embodiment of the present invention. [Figure 3] 1 is a side view of a bonded brittle substrate for explaining a division setting step in a scribing method according to an embodiment of the present invention; [Figure 4] 1 is a graph illustrating a scribing method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

[0019] The scribing method of the present invention is intended to cut bonded brittle substrates having terminals more efficiently and without damaging the terminals by dividing the planned travel path of a wheel on the bonded brittle substrates into sections and controlling the wheel speed, load, and cutting depth within each section in a controlled manner.

[0020] The basic configuration of this scribing method is a method for forming a scribe line on a bonded brittle substrate having a terminal portion, and includes a section setting step of dividing the planned travel path of a scribe wheel into a pre-cutting section, a main cutting section, and a terminal portion cutting section; a wheel positioning step of positioning the scribe wheel at the start point of travel of the pre-cutting section; a pre-cutting section line forming step of pressing the scribe wheel positioned at the start point of travel against the bonded brittle substrate and traveling while accelerating until a set speed; a main cutting section line forming step of traveling the scribe wheel without changing the speed after passing the pre-cutting section to form a scribe line in the main cutting section; a deceleration step of decelerating the traveling speed of the scribe wheel after passing the main cutting section before reaching the terminal portion, so that the control signal input per unit time is received at a shorter travel distance than before deceleration; and a terminal portion cutting section line forming step of traveling the scribe wheel through the terminal portion cutting section at the same traveling speed decelerated in the deceleration step to form a scribe line on the terminal portion.

[0021] Fig. 2 is a block diagram showing a method for scribing a bonded brittle substrate having a terminal portion according to one embodiment of the present invention, Fig. 3 is a side view of a bonded brittle substrate for explaining the section setting step in the scribing method, and Fig. 4 is a graph showing the scribing method according to one embodiment of the present invention.

[0022] As shown in the figure, the scribing method for a bonded brittle substrate having a terminal portion according to this embodiment includes a section setting step (101), a wheel positioning step (103), a pre-cutting section line forming step (105), a main cutting section line forming step (107), a deceleration step (109), a terminal cutting section line forming step (111), and a wheel raising step (113).

[0023] The division setting step (101) is a process of dividing the planned running path of the scribing wheel (19) into a pre-cutting section (A), a main cutting section (B), and a terminal cutting section (C).

[0024] The divisions are set by inputting set values ​​into a controller installed in the scribing device. That is, the operator determines the pre-cutting section (A) from one end of the bonded brittle substrate (10) to a point several millimeters away, and the actual cutting section (B) from the pre-cutting section to a specific point, and inputs the determined values. The length of each section is determined differently depending on the size, shape, material properties, etc. of the bonded brittle substrate (10).

[0025] However, it is advisable to set the distance of the pre-cutting section (A) to 5% or less of the total travel distance (L) of the scribing wheel (19). For example, if the total travel distance is 500 mm, it should be set to 25 mm or less.

[0026] The pre-cutting section (A) is a preparation section through which the scribing wheel (19) travels before entering the main cutting section (B).

[0027] Furthermore, the main cutting section (B) ends before the point where the terminal section (13a) begins. In other words, the boundary between the main cutting section (B) and the terminal section cutting section (C) is located in front of the upstream side of the terminal section (13a). "Upstream" refers to the direction in which the scribing wheel (19) approaches. The reason for positioning the boundary between the main cutting section (B) and the terminal section cutting section (C) in front of the upstream side of the terminal section is to allow the scribing wheel to enter the terminal section (13a) in a decelerated state.

[0028] Once the pre-cutting section (A), the main cutting section (B) and the terminal cutting section (C) are determined through the section setting step (101), the wheel positioning step (103) follows.

[0029] The wheel positioning step 103 is a process of positioning the scribing wheel 19 at the starting point of the pre-cutting section A. The scribing wheel 19 is installed on the head of the scribing device and is configured to move up or down.

[0030] The next pre-cutting section line forming step (105) is a process of starting the scribing wheel (19) to form a scribing line in the pre-cutting section (A). That is, the scribing wheel (19) positioned at the starting point of travel is pressed against the brittle substrate (10) and travels at an accelerated speed.

[0031] The pre-cutting section line forming step (105) includes an acceleration step (105a), a cutting depth primary adjustment step (105b), and a wheel load primary adjustment step (105c). The acceleration step (105a) is a step of increasing the moving speed of the scribing wheel (19) from 0 mm / s to the traveling speed in the main cutting section (B). The speed of the scribing wheel (19) in the main cutting section (B) can be, for example, 300 mm / s.

[0032] The first cutting depth adjustment process (105b) is a process for adjusting the cutting depth within the pre-cutting section (A). The cutting depth is the maximum depth that the wheel shaft of the scribing wheel (19) can descend. In other words, it is the maximum depth that the wheel shaft can descend when the surface of the bonded brittle substrate (10) is set to 0. The cutting depth varies depending on the thickness of the bonded brittle substrate (10), and can be, for example, -0.02 mm (on the graph).

[0033] The cutting depth is set by inputting the cutting depth into the controller. For example, inputting 0.02 into the controller sets the maximum depth that the wheel shaft can descend to 0.02 mm below the surface of the bonded brittle substrate 10. If the cutting depth is set to a value greater than the thickness of the bonded brittle substrate 10, the wheel shaft can penetrate the surface of the table T and descend to the bottom.

[0034] The input cutting depth is determined according to the condition of the bonded brittle substrate 10. For example, if the bonded brittle substrate 10 in the pre-cutting section A is thin or weak, the cutting depth is reduced. Conversely, if the bonded brittle substrate 10 in the pre-cutting section A is thick and firmly supported by the table, the cutting depth is set deeper (the cutting amount is increased). The deeper the cutting depth, the deeper the depth to which the scribing wheel 19 can actually descend. This cutting amount can be adjusted in multiple stages as needed.

[0035] The first wheel load adjustment process (105c) is a process of adjusting the pressure applied to the feel axis. In other words, it adjusts the force with which the scribing wheel (19) presses the brittle substrate (10) to be bonded. Adjusting the wheel load is separate from adjusting the cutting depth. The cutting depth and wheel load are input independently through the controller. However, if the wheel load is increased too much, the depth that can be reduced with the set wheel load cannot exceed the set cutting depth.

[0036] The average depth of cut imparted to the scribe wheel passing through the pre-cutting section (A) and the terminal portion cutting section (C) described later is relatively smaller than the depth of cut in the main cutting section (B).

[0037] The wheel load in the pre-cutting section (A) can be appropriately controlled through the first wheel load adjustment process (105c). For example, to reduce the stress applied to the bonded brittle substrate (10) at the moment cutting begins, a wheel load smaller than the wheel load planned for the main cutting section (B) can be applied, or (depending on the size and shape of the bonded brittle substrate) a wheel load relatively larger than the wheel load in the main cutting section can be applied. The greater the wheel load, the deeper the scribe line.

[0038] The main cutting section line forming step (107) is a process in which the scribe wheel (19) that has passed through the pre-cutting section (A) travels at a constant speed through the main cutting section (B). The scribe wheel (19) that has entered the main cutting section (B) passes through the main cutting section (B) without changing its speed and enters the terminal cutting section (C).

[0039] The cutting depth in the actual cutting section (B) is greater than the average cutting depth in the pre-cutting section (A). The cutting depth at the boundary between the pre-cutting section (A) and the actual cutting section (B) is the same as the cutting depth in the actual cutting section (B). While the scribing wheel (19) crosses the boundary between the pre-cutting section (A) and the actual cutting section (B), the cutting depth is increased by the control of the controller.

[0040] Additionally, the wheel load in the main cutting section (B) may be smaller than the wheel loads in the pre-cutting section (A) and the terminal cutting section (C). For example, if the wheel loads in the pre-cutting section (A) and the terminal cutting section (C) are 6N and 7N, respectively, the wheel load in the main cutting section (B) may be 5N. However, the magnitude of the wheel load in each section may vary depending on the thickness of the bonded brittle substrate (10) and the length of each section.

[0041] The scribing wheel (19) passes through the main cutting section (B) while maintaining the above-mentioned speed, wheel load and cutting depth, thereby forming a scribe line in the main cutting section (B).

[0042] The subsequent deceleration step (109) is a process of slowing down the traveling speed of the scribe wheel after passing through the main cutting section (B) before it reaches the terminal portion. That is, the scribe wheel (19) is decelerated within the deceleration section (E). The deceleration section (E) is the section between the boundary between the main cutting section (B) and the terminal portion cutting section (C) and the point where the lower plate (15) ends. The terminal portion (13a) begins from the point where the lower plate (15) ends. The speed of the scribe wheel (19) after being decelerated varies depending on the condition of the bonded brittle substrate (10) and can be, for example, 8 mm / s.

[0043] The reason for slowing down the speed of the scribe wheel (19) in this way is to make the control signal input per unit time be received once per moving distance that is shorter than before the speed reduction.

[0044] Typically, a controller in a scribing device outputs control signals in scan units without rest. One scan is, for example, 100 ms. The controller outputs the necessary control signals within 100 ms, and at 100 ms time intervals. The output of such control signals is independent of the moving speed of the scribing wheel (19). The faster the moving speed of the scribing wheel (19) over a certain distance, the fewer the number of control signals transmitted to the scribing wheel. Naturally, the fewer the number of control signal receptions, the lower the operating precision of the device.

[0045] For example, if the scribe wheel (19) travels a 100 mm long path in 100 ms, the scribe wheel will receive only one control signal (it is possible that the scribe wheel receives two signals, at the 0 mm and 100 mm points, by coincidence, but this is out of the question).

[0046] In contrast, if the scribe wheel (19) travels a distance of 100 mm in 10 seconds, it receives a control signal 100 times in those 10 seconds. In other words, the scribe wheel receives a control signal after moving a short distance, and then receives another control signal after moving a short distance further. Naturally, the frequent reception of control signals increases the operational precision.

[0047] In this embodiment, the deceleration step 109 is performed to reduce the traveling speed of the scribe wheel 19 before it enters the terminal portion 13a, thereby improving the control precision of the scribe wheel 19 at the terminal portion 13a. The reason for improving the control precision is to prevent cracks in the terminal portion 13a and to achieve clear scribe lines on the terminal portion 13a.

[0048] The terminal cutting section line forming step 111 includes a second cutting depth adjusting step 111a and a second wheel load adjusting step 111b. In some cases, the second wheel load adjusting step 111b can be omitted.

[0049] The second cutting depth adjustment process (111a) stores the position of the scribe wheel (19) just before it enters the terminal portion, resets the cutting depth in the main cutting section (B) to the current position, and after resetting, changes the cutting depth to be applied in the terminal portion cutting section (C) to the target position based on the current position of the scribe wheel (19) (the position just before it enters the terminal portion).

[0050] The reason for carrying out the second cutting depth adjustment process (111a) is, of course, to adjust the depth to which the scribe wheel (19) penetrates into the bonded brittle substrate (10) to obtain a good cutting line at the terminal portion (13a).

[0051] As described above, by adjusting the cutting depth based on the current position immediately before entering the terminal cutting section C, it is possible to avoid the influence of variations in the flatness of the table or the bonded brittle substrate 10. This is because, for example, when multiple scribing heads simultaneously form multiple parallel scribe lines, the cutting depth of the terminal portion 13a, i.e., the target position, can be adjusted for each head based on the current position of the scribe wheel.

[0052] That is, the scribing precision is uniform regardless of variations in the flatness of the bonded brittle substrate 10. In other words, if the cutting depth in the terminal cutting section C is set based on the surface position of the substrate in the pre-cutting section, the penetration depth of the scribe wheel of each head into the terminal section during terminal cutting may vary depending on the flatness of the substrate, but in this embodiment, even equipment with multiple heads is not affected by the flatness of the bonded brittle substrate 10.

[0053] The secondary wheel load adjustment process (111b) is a process of increasing the wheel load. In this cutting section (B), since the upper plate (13) is supported by the lower plate (15), a clear scribe line can be formed even with a relatively small wheel load. However, if the same wheel load is applied to the terminal portion (13a) floating in the air, the terminal portion (13a) may be elastically deformed downward, resulting in a faint scribe line or no scribe line at all.

[0054] The secondary wheel load adjustment process (111b) is performed within the range of elastic deformation of the terminal portion (13a). For example, the load, which was 5N in the main cutting section (B), can be increased to 7N within the range of elastic deformation. By increasing the wheel load in this way, a clear scribe line can be formed on the upper surface of the terminal portion (13a) that is floating in the air.

[0055] The subsequent wheel raising step 113 is a step of raising the scribing wheel 19 after the scribing line has been formed on the terminal portion 13a. The scribing process is completed through the wheel raising step 113.

[0056] In the explanation of this embodiment, the scribing method of the bonded brittle substrate (10) set on the table (T) has been given as an example, but the scribing method of this embodiment can also be applied to a top and bottom simultaneous scribing method in which the scribe wheels are located on the top and bottom of the substrate.

[0057] Although the present invention has been described in detail above through specific examples, the present invention is not limited to the above examples and various modifications can be made by those skilled in the art within the scope of the technical concept of the present invention. [Explanation of symbols]

[0058] 10 Bonded brittle substrate 13 Upper Plate 13a Terminal section 15 Lower plate 19 Scribe Wheel T-table

Claims

1. A method for forming a scribe line on a bonded brittle substrate having a terminal portion, comprising: A section setting step of dividing the planned travel path of the scribe wheel into a pre-cutting section, a main cutting section, and a terminal cutting section; a wheel positioning step of positioning the scribing wheel at a travel start point of the pre-cutting section; A pre-cutting section line forming step in which the scribe wheel positioned at the travel start point is pressed against the bonded brittle substrate and travels while accelerating until it reaches a set speed; a main cutting section line forming step of forming a scribe line in a main cutting section by running the scribing wheel that has passed through the pre-cutting section at a set speed; a deceleration step of decelerating the traveling speed of the scribe wheel after passing through the main cutting section before the scribe wheel reaches the terminal portion, so that the control signal input per unit time is received for each moving distance shorter than before the deceleration; and a terminal portion cutting section line forming step of passing the scribing wheel through the terminal portion cutting section at the traveling speed reduced in the deceleration step to form a scribe line on the terminal portion. A method for scribing a bonded brittle substrate having a terminal portion.

2. A method for scribing a bonded brittle substrate having a terminal portion according to claim 1, The step of forming a line for cutting the terminal portion includes: a step of storing the position of the scribe wheel immediately before entering the terminal portion, resetting the cutting depth in the actual cutting section to the cutting depth at the current position, and changing the cutting depth to be applied in the terminal portion cutting section to a target position based on the current position after resetting; A method for scribing a bonded brittle substrate having a terminal portion.

3. A method for scribing a bonded brittle substrate having a terminal portion according to claim 1, an average cutting depth imparted to the scribe wheel passing through the pre-cutting section and the terminal portion cutting section is equal to or less than an cutting depth imparted to the scribe wheel in the main cutting section; A method for scribing a bonded brittle substrate having a terminal portion.

4. A method for scribing a bonded brittle substrate having a terminal portion according to claim 1, a wheel load applied by the scribing wheel to press the bonded brittle substrate in the terminal portion cutting section is relatively larger than a wheel load applied by the scribing wheel to press the bonded brittle substrate in the main cutting section; A method for scribing a bonded brittle substrate having a terminal portion.

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