Substrate cutting device and substrate cutting method

Abstract

This invention provides a substrate cutting apparatus and method that can perform thermally efficient cutting of glass substrates by generating thermal stress, and can cut all scribe lines of arbitrary shapes, including curved lines or folds, in one operation. The substrate cutting apparatus of this invention comprises: heat transfer rods 6 made of a material with good thermal conductivity; a worktable 1 made of a material with good thermal conductivity and in which mounting holes for inserting the heat transfer rods 6 are formed; a plate 8 made of a material with good thermal conductivity and supported in a manner that insulates the worktable 1 from heat; a first temperature setting mechanism 2 that sets the worktable 1 to a first set temperature T1; and a second temperature setting mechanism 12 that sets the plate 8 to a second set temperature T2. Each heat transfer rod 6 is held in a manner that insulates the worktable 1 from heat, with one end coplanar with the substrate mounting surface of the worktable 1 and the other end conducting heat with the plate 8. The mounting holes 5 formed on the worktable 1 are positioned such that a plurality of them are opposite each other along the scribe lines when the substrate is placed on the mounting surface.

Description

Technical Field

[0001] This invention relates to a cutting apparatus and method for cutting glass substrates pre-grooved with scribe lines along the scribe lines. The invention primarily targets glass substrates used in flat panel displays (FPDs) for applications such as televisions, mobile terminals, and game consoles. Prior Technology

[0002] Traditionally, the substrate has been cut by mechanically scribing with a scribing wheel or by laser scribing. The substrate is then cut along these scribing lines in the next step (cutting step). In this cutting step, the substrate is cut using the following methods: pressing a long, downward-tapered (knife-shaped) break bar along the scribing lines and bending the substrate into a V-shape (see, for example, Patent Document 1); or using a heating medium such as steam to generate thermal stress, causing cracks in the scribing lines to penetrate the substrate in the thickness direction and cut the substrate (see Patent Document 2). [Previous Technical Documents] [Invention Patent Documents]

[0003] [Invention Patent Document 1] Japanese Patent Application Publication No. 2016-120725. [Invention Patent Document 2] WO2004 / 067243. Summary of the Invention

[0004] [The problem that the invention aims to solve]

[0005] However, in the cutting method described in Patent Document 1, which uses a cutting bar to press the substrate surface and bend it into a V-shape, the way the pressing load is applied causes the upper edges of adjacent cut surfaces to interfere with each other, resulting in defects. Furthermore, this can lead to cracking on the substrate surface or deterioration of the end-face strength. Additionally, the scribe line, which is the object of cutting, is essentially straight like the cutting bar, and the cutting bar must be accurately aligned with the straight scribe line for cutting.

[0006] In contrast, the thermal stress separation method described in Patent Document 2 is superior because it separates the substrate without contact, thus avoiding the risk of damage caused by the pushing of the separated ends due to bending. However, since it uses a heat medium such as steam blown from a nozzle that is spatially separated from the scribe line for convective heat transfer, it suffers from poor heat utilization efficiency and is uneconomical. Furthermore, the blowing action agitates the atmospheric gas, which, if containing dust, could negatively impact product yield. In addition, the assembly structure of the heating mechanism with the heat source becomes complex and bulky.

[0007] Furthermore, since in any of the above cases, after one scribe line is cut off, the substrate is moved relative to the cutting rod or the thermal jet section to cut off the next scribe line, there is a need to shorten the time required to cut off all scribe lines as much as possible.

[0008] Therefore, in view of the above-mentioned issues, the object of the present invention is to provide a substrate breaking apparatus and a substrate breaking method that employs thermal stress breaking without worrying about damage to the breaking end face, and has low heat loss and excellent work efficiency. [Technical means to solve the problem]

[0009] To achieve the above objectives, the present invention employs the following technical means: the substrate cutting device of the present invention is a substrate cutting device that cuts a substrate with etched grooves along the grooves, comprising: a plurality of columnar heat transfer rods comprising a material with good thermal conductivity; a worktable of a material with good thermal conductivity having a plurality of mounting holes into which the heat transfer rods can be inserted on a mounting surface on which the substrate is placed; a plate of a material with good thermal conductivity supported on the opposite side of the mounting surface to the worktable in a manner that thermally insulates the worktable; a first temperature setting mechanism for setting the worktable to a first set temperature T1; and a second temperature setting mechanism for setting the plate to a second set temperature T2. Each of the aforementioned heat transfer rods is configured to thermally insulate the worktable, and one end of the rod is located on the same plane as the mounting surface, while the other end is in surface contact with the plate for heat conduction. The positions of the aforementioned mounting holes formed on the aforementioned worktable are configured to include at least a plurality of positions that would be opposite to the aforementioned scribe lines when the aforementioned substrate is placed on the aforementioned mounting surface. Here, the temperature difference between the first set temperature T1 and the second set temperature T2 is sufficient to cause a difference in thermal stress between the substrates in contact with each other.

[0010] According to the present invention, when a substrate is placed on the mounting surface of a worktable, heat transfer rods are pre-inserted into a plurality of mounting holes (along the scribe lines) located opposite to the scribe lines of the substrate, so that the set temperature of each heat transfer rod can be achieved through heat conduction from the plate to become a second set temperature T2, and the temperature of the worktable becomes a first set temperature T1. In this state, when the substrate to be separated is placed such that its scribe lines abut against the heat transfer rods inserted into the mounting holes of the worktable, areas that contact the worktable at the first set temperature T1 and areas that contact the heat transfer rods at the second set temperature T2 are alternately generated on the scribe lines, and a thermal stress distribution is formed along the scribe lines, applying a separation force to separate the scribe lines, thereby separating the substrate. [Benefits of the Invention]

[0011] According to the present invention, by pre-inserting a heat transfer rod into mounting holes located along multiple scribe lines on a substrate, it becomes possible to simultaneously separate multiple scribe lines or simultaneously cut multiple unit substrates. This method reduces the time required to separate substrates and improves work efficiency. Furthermore, by aligning the insertion point of the heat transfer rod with the scribe line, it is possible to separate scribe lines of arbitrary shapes, including curved lines or zigzag lines, and to cut unit substrates with arbitrary outlines, such as circles. Furthermore, in this invention, since the substrate is not broken by bending it with a break bar, a high-quality end face without defects such as breaks can be obtained on the broken surface of the substrate. Also, since thermal stress is applied to the substrate through surface contact heat conduction, it has the effect of suppressing and reducing heat loss, and suppressing the flying of dust generated during breaking due to the blowing of steam, or suppressing the adhesion of particles to the surface of the product that has become damp due to steam.

[0012] In this invention, the aforementioned mounting holes may also be formed in a mesh or grid pattern at certain intervals on the aforementioned mounting surface. In this way, by selecting the mounting hole into which the heat transfer rod is to be inserted, it is easy to cut along a groove of any shape, including straight lines and curves.

[0013] In this invention, one of the first temperature setting mechanism and the second temperature setting mechanism may be a heating mechanism that uses an electric heater to heat the temperature, and the other may be a water cooling mechanism.

[0014] In this invention, a robotic arm may also be provided to adsorb and hold the aforementioned substrate for placement on the aforementioned placement surface, and to remove the segmented aforementioned substrate from the aforementioned placement surface. In this way, the substrate can be transported to the mounting surface and kept in contact, and the action of removing the separated substrate from the mounting surface can be performed efficiently.

[0015] Another approach to substrate cutting of the present invention involves placing a substrate with etched grooves on a worktable and cutting it along the etched grooves. The method includes the following steps: preparing the worktable, wherein the worktable has a mounting surface for placing the substrate set to a first set temperature T1, and a plurality of regions with a second set temperature T2 set at intervals relative to the position of the etched grooves when the substrate is placed relative to the position of the worktable; and cutting the substrate by making the etched grooves surface-contact with the mounting surface of the worktable. Simple Explanation of the Diagram

[0016] [Figure 1] is a schematic front view showing a substrate splitting device according to one embodiment of the present invention. [Figure 2] is a right-side view of the workbench portion of Figure 1. [Figure 3] is an exploded perspective view of the workbench and board in Figure 1. [Figure 4] is an explanatory diagram showing the process of installing the heat transfer rod on the workbench in Figure 1. [Figure 5] is a top view showing an example of one of the substrates to be separated. [Figure 6] is a diagram showing the arrangement of heat transfer rods when the substrate shown in Figure 5 is cut. [Figure 7] is an explanatory diagram showing the heating and cooling areas formed on the substrate (the scribing path) through the heat-conducting rod and the worktable. [Figure 8] is a diagram showing the arrangement of heat transfer bars when other types of unit substrates are cut. [Figure 9] is a diagram showing the arrangement of heat transfer rods when a circular unit substrate is divided. Implementation

[0017] The following is a detailed description of the invention with reference to the drawings. Figures 1 to 4 are diagrams illustrating a substrate splitting apparatus according to an embodiment of the present invention, and Figure 5 is a top view showing a substrate W to be split. On the substrate W, shallow grooves S of mutually orthogonal longitudinal and transverse lines are processed in a previous step, thereby dividing it into a plurality of unit substrates W1, for example, six as shown in Figure 5, and peripheral end materials E, which will become products after splitting. Although the grooves S are processed by mechanical scribing by pressing a scribing wheel against the substrate surface while rotating it, they can also be formed by laser scribing.

[0018] The substrate splitting device A includes a horizontal worktable 1 for holding the substrate W to be split, and a robotic arm (transfer arm) 14 for adsorbing and holding the substrate W to be split and placing it on the worktable 1, and for removing the split unit substrate W1 from the surface of the worktable 1.

[0019] The workbench 1 is made of a metal with good thermal conductivity, such as aluminum or copper, and is designed to maintain a first set temperature T1 (refrigerant temperature) by circulating a refrigerant, such as cold water, within an internal circulation channel 2 (water-cooled jacket). The inlet 3 and outlet 4 of the circulation channel 2 are connected to a refrigerant source (not shown) via pipes. The refrigerant temperature is adjusted to the desired temperature using a temperature control device (not shown) for the refrigerant source. Furthermore, on the flat mounting surface (upper surface) of the workbench 1, a plurality of mounting holes 5 are provided in a mesh (or grid) pattern, through which the heat transfer rod 6 (described later) can be inserted, with adjacent mounting holes 5 evenly spaced.

[0020] The heat transfer rod 6 is formed of a metal material with good thermal conductivity, such as aluminum or copper, as shown in Figure 4(a). It is cylindrical in shape and can be easily inserted into the mounting hole 5. The outer peripheral surface in contact with the mounting hole 5 is covered with a heat insulation material 6a. In addition, by precision machining the heat transfer rod 6 and the mounting hole 5, a space can be created between the heat transfer rod 6 and the mounting hole 5, so that the heat transfer rod 6 and the mounting hole 5 are in a non-contact state to achieve thermal insulation. As shown in Figure 4(b), at least a portion or the entire surface of the upper end of the heat transfer rod 6 is flat, and it is designed such that when the heat transfer rod 6 is mounted in the mounting hole 5, the upper surface of the heat transfer rod 6 and the upper surface (placement surface) of the worktable 1 are located on the same plane. Furthermore, an insertion part 6b is provided on the lower end side of the heat transfer rod 6, and the insertion part 6b is inserted into the socket 7 (hole) of the plate 8 described later.

[0021] On the underside of the workbench 1 (opposite to the mounting surface), a plate 8 made of a metal material with good thermal conductivity, such as aluminum or copper, is connected with a plurality of sockets 7, with a gap provided by ceramic connecting bolts 9 and nuts 10 made of thermally insulating material. The gap between the workbench 1 and the plate 8 serves as an insulating space to insulate the heat between the two, and cylindrical spacers 11 are installed around the connecting bolts 9 between the workbench 1 and the plate 8 to maintain the gap.

[0022] The groups of sockets 7 on the aforementioned plate 8 are respectively positioned opposite the mounting holes 5 on the worktable 1 located above. In this manner, by inserting the heat transfer rod 6 into the mounting hole 5 from the upper surface (placement surface) of the worktable 1, its lower insertion portion 6b can be installed into the socket 7, and the heat transfer rod 6 and plate 8 become heat-conducting through surface contact, allowing heat transfer from the plate 8 to the heat transfer rod 6. An electric heater 12 is assembled on the plate 8, and the heat from the plate 8 heated by the electric heater 12 is transferred to the heat transfer rod 6, thus setting the upper surface of the heat transfer rod 6 to a second set temperature T2. Furthermore, the electric heater 12 is connected to a power source (not shown) via a wire 13, and can be adjusted to the desired temperature using a temperature control device (not shown).

[0023] The robotic arm 14 is equipped with a suction cup 15 for vacuum adsorption of the substrate W. Although in this embodiment, the robotic arm 14 is provided with 6 suction cups to adsorb 6 unit substrates W1 to be separated, the robotic arm 14 may also be formed by using a large suction cup to adsorb 6 unit substrates W1.

[0024] Here, we will explain the first set temperature T1 of the worktable 1 and the second set temperature T2 of the plate 8 (i.e., the heat transfer rod 6). In this embodiment, by bringing the substrate W of the object to be separated into contact, reverse thermal stresses (compressive stress and tensile stress) are generated along the scribe line in the cooling area L2, which is in contact with and cooled on the upper surface (placement surface) of the worktable 1, and the heating area L1, which is in contact with and heated on the heat transfer rod 6. This generates a strong separation force on the scribe line, so that as long as a large temperature difference is applied between the first set temperature T1 and the second set temperature T2, a stronger separation force can be generated. However, for substrates such as LCD panels, the heatable temperature is limited by other materials (circuit circuits, adhesives, etc.) disposed on the substrate, and the temperature needs to be kept below the allowable temperature. Furthermore, regarding cooling, it is preferable to perform cooling within a non-condensing range. Therefore, the first set temperature T1 and the second set temperature T2 are set within the allowable temperature range of the substrate of the object being processed. For example, the first set temperature T1 of the worktable 1 is set to 20°C above the dew point temperature, and the second set temperature T2 of the heat transfer rod 6 (and plate 8) is set in the range of 110°C to 60°C, which is high enough to be higher than the first set temperature T1.

[0025] Next, the cutting operation of the substrate W using the cutting device A described above will be explained. It should be noted that in the following explanation, each substrate W is sequentially transported and placed on the worktable 1 by the robotic arm 14, and is always accurately positioned and placed at the same position on the worktable 1 by the robotic arm 14 (or by using a positioning means such as a contact member). First, as shown in Figure 6, the heat transfer rod 6 is pre-inserted into the mounting hole 5, which is positioned opposite to the scribe line S of the substrate W placed on the worktable 1 (the shaded area represents the heat transfer rod 6). In this operation, as shown in Figure 4(a), it can be directly inserted from the upper surface of the worktable 1 and installed into the slot 7 of the plate 8 as shown in Figure 4(b).

[0026] After the heat transfer rod 6 is placed on the worktable 1, the refrigerant flows in the circulation channel 2 of the worktable 1 to cool the worktable 1 to the first set temperature T1 (refrigerant temperature), and the electric heater 12 is powered on to heat the plate 8 (and the heat transfer rod 6) to the second set temperature T2.

[0027] Next, as shown in Figure 1(a), the substrate W, which is adsorbed and held by the robotic arm 14, is transported to a fixed position above the worktable 1, and as shown in Figure 1(b), the robotic arm 14 is lowered so that the lower surface of the substrate W contacts the upper surface (placement surface) of the worktable 1. Although the contact time varies depending on the thickness of the substrate, about 2 seconds is sufficient for a typical substrate. Through this contact, since heat transfer rods 6 are arranged and installed at positions opposite each other along the scribe lines S of the substrate W, the area on the scribe line S that contacts the heat transfer rods 6 is locally heated, while the area on the scribe line S that contacts the surface of the worktable 1 is locally cooled.

[0028] As shown in Figure 7, the heating area L1 that contacts the heat transfer rod 6 and the cooling area L2 that contacts the heat transfer rod 6 on the substrate W will alternately form adjacent terrain along the etched path S. In this way, compressive stress is generated in the scribe line S due to thermal expansion in the heating region L1, and tensile stress is generated in the scribe line S due to thermal contraction in the cooling region L2. Because these compressive and tensile stresses are generated simultaneously at multiple adjacent locations, cracks in the scribe line S penetrate through the thickness direction of the substrate W, resulting in the complete severance of the scribe line S. Thus, the substrate W is divided into 6 unit substrates W1 and end pieces E.

[0029] The segmented unit substrate W1 is removed by the robotic arm 14 and sent to the next step. The remaining end material E is removed from the worktable 1 in the next step by the same robotic arm 14 or other end material removal means not shown (e.g., a cleaner for picking up end materials).

[0030] By pre-embedding the heat transfer rod 6 into the mounting hole 5 of the worktable 1 along the shape of the scribe line S to be separated, the unit substrate W1 with any outline can be separated by thermal stress. For example, a unit substrate with a part of its edge recessed into a U-shape, as shown in Figure 8, or a circular unit substrate, as shown in Figure 9, can be separated and removed along the scribe line S.

[0031] As described above, in the substrate cutting apparatus of the present invention, by inserting a heat transfer rod into a mounting hole corresponding to the position along the scribe line of the substrate, it becomes possible to simultaneously cut multiple scribe lines or simultaneously cut multiple unit substrates. This shortens the time required to cut the substrate and improves work efficiency. Furthermore, by selecting the mounting position of the heat transfer rod, it is possible to cut scribe lines of arbitrary shapes, including curved lines or zigzag lines, or to cut unit substrates with arbitrary outlines such as circles.

[0032] Furthermore, because this invention does not use a blade-shaped cutting rod to bend the substrate for cutting, a high-quality end face without defects such as breaks can be obtained on the cut surface of the substrate. Also, since thermal stress is applied to the substrate through surface contact heat conduction, there is no dust flying during cutting due to the blowing of steam, and the adhesion of particles to the surface of the product that has become damp due to steam can be suppressed, thus reducing and suppressing heat loss.

[0033] While the present invention has been described above with reference to representative embodiments, the present invention is not necessarily limited to the above-described embodiments, and appropriate modifications and alterations may be made to achieve its purpose without departing from the scope of the invention claims. For example, in the above embodiment, although the workbench 1 is cooled and the plate 8 is heated, it is also possible to install an electric heater on the workbench 1 for heating and to cool the plate 8. Alternatively, the heating or cooling means can be replaced with other methods. In the above embodiments, although a plurality of mounting holes are arranged in a mesh or grid pattern on the worktable 1, if the shape of the scribing path S' to be separated is always the same and will not change, a dedicated worktable that forms mounting holes only at positions opposite to the position along the scribing path S' and does not have extra mounting holes can also be used. In the above embodiments, although all the mounting holes are round holes, they may also be partially or entirely elliptical holes or corner holes, and the shape of the heat transfer rod may also be an elliptical cylinder, a corner cylinder, etc. [Industry availability]

[0034] The present invention relates to a substrate cutting device and a substrate cutting method applicable to cutting a substrate with etched grooves along the etched grooves.

[0035] 1: Workbench 2: Circulation Channel (First Temperature Setting Mechanism) 3: Entrance 4: Exports 5: Mounting holes 6: Heat transfer rod 6a: Thermal insulation material 6b: Insertion section 7: Socket 8: Board 9: Connecting bolts 10: Nuts 11: Spacing 12: Electric heater (second temperature setting mechanism) 13: Electrical wire 14: Robotic arm (transfer arm) 15: Suction Cup A:Breaking device E: End material L1: Heating area L2: Cooling area S: Carved Road W: substrate W1: Unit substrate

Claims

1. A substrate cutting device for cutting a substrate with etched grooves along the grooves, comprising: a plurality of heat transfer rods, which are columnar and comprise a material with good thermal conductivity; a worktable made of a material with good thermal conductivity, having a plurality of mounting holes formed on a mounting surface on which the substrate is placed, into which the heat transfer rods can be inserted; a plate made of a material with good thermal conductivity, which is supported on the opposite side of the mounting surface of the worktable in a manner that thermally insulates the worktable from the worktable; a first temperature setting mechanism for setting the worktable to a first set temperature T1; and a second temperature setting mechanism for setting the plate to a second set temperature T2; each of the heat transfer rods is maintained in a manner that thermally insulates the worktable from the worktable, and one end of the rod is located on the same plane as the mounting surface, while the other end of the rod is in surface contact with the plate for heat conduction; The positions of the aforementioned mounting holes formed on the aforementioned worktable are formed in such a way that there are at least a plurality of positions that would be opposite to the aforementioned scribe lines when the aforementioned substrate is placed on the aforementioned mounting surface.

2. The substrate splitting device as described in claim 1, wherein, The aforementioned mounting holes are formed in a mesh or grid pattern at certain intervals on the aforementioned mounting surface.

3. The substrate breaking device described in either claim 1 or claim 2, wherein one of the aforementioned first temperature setting mechanism and the aforementioned second temperature setting mechanism uses a heating mechanism that uses an electric heater and the other uses a water cooling mechanism.

4. The substrate splitting apparatus as described in either claim 1 or claim 2, comprising: a robotic arm that adsorbs and holds the aforementioned substrate for placement on the aforementioned placement surface, and removes the split aforementioned substrate from the aforementioned placement surface.

5. A substrate cutting method, comprising placing a substrate with etched grooves on a worktable and cutting it along the etched grooves, the method comprising the following steps: Prepare the aforementioned worktable, wherein the aforementioned worktable has a first set temperature T1 for the mounting surface used to mount the aforementioned substrate, and a plurality of regions are formed at intervals relative to the position of the aforementioned worktable along the aforementioned scribe line when the aforementioned substrate is mounted, and are set to a second set temperature T2 that is different from the aforementioned first set temperature T1; and the aforementioned scribe line is made to make surface contact with the aforementioned mounting surface of the aforementioned worktable, and is separated along the aforementioned scribe line.

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