Heat treatment device

Abstract

A heat treatment device (1) comprises a chamber (2) that accommodates a glass substrate (3), a heater (4) that is at least partially positioned inside the chamber (2), a heater tube (5) that covers the heater (4) but has both ends outside the chamber (2), a ladder member (6) that supports the glass substrate (3) inside the chamber (2), a positioning pin (7) that is provided to the heater tube (5) and positions the ladder member (6) with respect to the heater tube (5), and a position adjustment mechanism (8) that is provided to at least one end of the heater tube (5) and adjusts the relative positions of the chamber (2) and the heater tube (5) in the axial direction of the heater tube (5).

Description

Heat treatment apparatus

[0001] The present disclosure relates to a heat treatment apparatus including a chamber for accommodating a heat treatment target.

[0002] There is known a heat treatment apparatus including a chamber for accommodating a substrate, a heater at least partially located within the chamber, and a heater tube covering the heater and having both ends located outside the chamber (Patent Document 1). This heater tube is firmly fixed to the outer wall of the chamber by a housing.

[0003] Japanese Patent Application Laid-Open No. 2020-27943

[0004] The heater tube is provided with positioning pins for positioning a ladder that supports the substrate within the chamber. However, due to repeated high-temperature heat treatment, displacement due to repeated thermal contraction occurs in the axial position of the heater tube.

[0005] Therefore, it is necessary to disassemble the chamber at the portion where the heater tube is fixed and adjust the axial position of the heater tube. Thus, this position adjustment work cannot be performed in a high-temperature heat treatment state, and it is necessary to turn off the heater each time and wait for the chamber to cool down before performing the position adjustment work. For this reason, there is a problem that the chamber needs to be cooled for work safety, and a large amount of work time is required.

[0006] A heat treatment apparatus according to an aspect of the present disclosure includes a chamber for accommodating a substrate, a heater at least partially located within the chamber, a heater tube covering the heater and having both ends located outside the chamber, a support member for supporting the heat treatment target within the chamber, a positioning member provided on the heater tube for positioning the support member with respect to the heater tube, and a position adjustment mechanism provided at at least one of both ends of the heater tube for adjusting a relative position between the chamber and the heater tube in the axial direction of the heater tube.

[0007] According to an aspect of the present disclosure, it is possible to correct an axial displacement of the heater tube with respect to the chamber provided in the heat treatment apparatus without disassembling the chamber.

[0008] This is a perspective view showing the internal configuration of a heat treatment apparatus according to an embodiment. This is a top view of the heat treatment apparatus. This is a front view of the heat treatment apparatus. This is a cross-sectional view of a heater, heater tube, and related components provided in the heat treatment apparatus. This is a cross-sectional view of the main parts of the heater, heater tube, and related components. This is a cross-sectional view of a position adjustment mechanism provided in the heat treatment apparatus. This is a front view of the position adjustment mechanism. This is a cross-sectional view of a position adjustment mechanism according to a comparative example.

[0009] Figure 1 is a perspective view showing the internal configuration of the heat treatment apparatus 1 according to an embodiment. Figure 2 is a top view of the heat treatment apparatus 1. Figure 3 is a front view of the heat treatment apparatus 1. Figure 4 is a cross-sectional view of the heater 4, heater tube 5, and related components provided in the heat treatment apparatus 1. Figure 5 is a cross-sectional view of the main parts of the heater 4, heater tube 5, and related components. Figure 6 is a cross-sectional view of the position adjustment mechanism 8 provided in the heat treatment apparatus 1. Figure 7 is a front view of the position adjustment mechanism 8.

[0010] As shown in Figures 1 to 7, the heat treatment apparatus 1 comprises a chamber 2 for housing a glass substrate 3 (to be heat treated), a rod-shaped heater 4 with at least a portion located inside the chamber 2, a heater tube 5 covering the heater 4 with both ends located outside the chamber 2, a ladder member 6 (support member, elongated member) for supporting the glass substrate 3 inside the chamber 2, a positioning pin 7 (positioning member) provided on the heater tube 5 for positioning the ladder member 6 relative to the heater tube 5, and a position adjustment mechanism 8 provided on at least one of the ends of the heater tube 5 for adjusting the relative position between the chamber 2 and the heater tube 5 in the axial direction of the heater tube 5. Preferably, the position adjustment mechanism 8 is provided on both ends of the heater tube 5. Figure 1 omits the chamber 2 for ease of understanding. The configurations shown in Figures 1, 2, and 4 show examples in which the position adjustment mechanism 8 is provided on both ends of the heater tube 5.

[0011] The glass substrate 3 is coated with, for example, PI (Polyimide). The heat treatment apparatus 1 may be a heater device for heating the PI-coated glass substrate 3 to form a PI film. The PI film serves as the base for an OLED (Organic Light Emitting Diode) substrate.

[0012] For example, as shown in Figure 1, a pair of heaters 4 and a pair of heater tubes 5 can be provided on a single glass substrate 3. Therefore, the relative position between the chamber 2 and the heater tubes 5 can be adjusted on a single glass substrate 3 by four position adjustment mechanisms 8 provided at each end of the two heater tubes 5.

[0013] The heater tube 5 is made of, for example, quartz.

[0014] The glass substrate 3 coated with PI is always transported by the robot to the same position on the ladder member 6. The ladder member 6 has a plurality of glass support pins 26 for supporting the glass substrate 3, as shown in Figure 4, for example.

[0015] As shown in Figures 4 to 7, the position adjustment mechanism 8 comprises a disc-shaped housing 9 (fixed member) fixed to the outer wall of the chamber 2, a disc-shaped housing cover 10 (movable member) fixed to the end of the heater tube 5 and movable relative to the housing 9, and a plurality of set screws 11 (adjustment members) that adjust the positional relationship of the housing cover 10 with respect to the housing 9. The set screws 11 can adjust the range in which the housing cover 10 can move relative to the housing 9. As shown in Figures 5 and 6, the set screws 11 are screwed into the housing cover 10, and the tips of the set screws 11 abut against the housing 9.

[0016] As shown in Figures 5 and 6, the position adjustment mechanism 8 is located between the housing 9 and the housing cover 10 and further includes a bellows 12 (expansion member) that generates a force in a direction that widens the gap between the housing 9 and the housing cover 10. As shown in Figure 1, the heat treatment apparatus 1 includes at least two sets of heaters 4 and heater tubes 5. The ladder member 6 is provided spanning at least two heater tubes 5. The configuration shown in Figure 1 shows an example of a heat treatment apparatus 1 in which pairs of heater tubes 5, each mounting a ladder member 6 that supports a glass substrate 3, are stacked in 12 layers. The ladder member 6 is a frame-shaped member for supporting the glass substrate 3. The ladder member 6 is fixed to the heater tubes 5.

[0017] As shown in Figure 4, two positioning pins 7 are provided for each heater tube 5. The ladder member 6 is placed between the two positioning pins 7. Figure 8 is a cross-sectional view of a position adjustment mechanism according to a comparative example. When heating and cooling treatments are repeatedly performed in the chamber 2 (PI cure oven) for heat curing the glass substrate 3 coated with PI (Polyimide), the heater tube 5 on which the ladder member 6 is mounted expands and contracts in the axial direction. As a result, the position of the positioning pins 7 and the ladder member 6 supporting the glass substrate 3 along the axial direction of the heater tube 5 changes, for example, in the direction of arrow 24 shown in Figure 8.

[0018] This change in position causes the glass substrate 3 to detach from the ladder member 6, resulting in substrate detachment. For example, if the heater tube 5 shifts significantly in either the axial direction due to thermal expansion and contraction, the glass substrate 3 will detach from the ladder member 8 that supports it within the chamber 2. Therefore, in the current process, the presence or absence of displacement of the ladder member 6 is checked by periodic visual inspection of scratches on the back surface of the glass substrate 3. These scratches on the back surface of the glass substrate 3 cannot be checked until after heat treatment in the chamber 2 and after the glass substrate 3 has been transported from the chamber 2. Therefore, if displacement of the ladder member 6 occurs and the scratches on the back surface are detected by visual inspection, for safety reasons, the heater must be turned off and the oven temperature of the chamber 2 lowered to a level where adjustment work is possible. Then, the housing cover 90 and housing 99 that fix the heater tube 5 to the outer wall of the chamber 2 must be disassembled, the position of the ladder member 6 adjusted, reassembled, the temperature of the chamber 2 raised, and the check performed again.

[0019] Such work may need to be performed several times due to the need for readjustment if it doesn't work properly, and the increasing MTTR (Mean Time To Recovery) required to correct the misalignment of the ladder member 6 is a challenge.

[0020] Therefore, the heat treatment apparatus 1 according to this embodiment proposes a configuration for a position adjustment mechanism 8 that can shorten the MTTR when correcting the misalignment of the ladder member 6.

[0021] Specifically, as shown in Figures 5 and 6, for example, the chamber 2 is provided with a housing 9 fixed to the outer wall, a housing cover 10 fixed to the end of the heater tube 5 and movable in the axial direction of the heater tube 5 relative to the housing 9, and a set screw 11 that screws into the housing cover 10 and whose tip abuts against the housing 9. A bellows structure 12 is provided between the housing 9 and the housing cover 10 and generates a force in the direction that widens the gap between the housing 9 and the housing cover 10.

[0022] The housing 9 is fixed to the outer wall of the chamber 2 by a plurality of fixing screws 15, as shown in Figures 6 and 7, for example. A mounting groove 16 is formed circumferentially on the surface of the housing 9 facing the chamber 2. An O-ring 14 is fitted into the mounting groove 16 to prevent leakage of the atmosphere inside the chamber 2. A through hole 13 is formed in the housing 9 through which the heater tube 5 passes.

[0023] A through hole 17 is formed in the housing cover 10 through which the heater tube 5 passes. A mounting groove 18 is formed circumferentially in the axial center of the inner surface of the through hole 17. An O-ring 19 for fixing the heater tube 5 to the housing cover 10 is fitted into the mounting groove 18.

[0024] The set screw 11 used to adjust the axial position of the heater tube 5 can be, for example, a set screw (grub screw) made of SUS (Steel Use Stainless). In the correction work to return the position of the ladder member 6 to its original position, when the worker tightens the set screw 11 with a wrench or screwdriver, the housing cover 10 that screws onto the set screw 11 moves away from the housing 9. As a result, the heater tube 5 fixed to the housing cover 10 moves in the axial direction of arrow 24. When the set screw 11 is loosened, the housing cover 10 moves towards the housing 9, so the heater tube 5 moves in the axial direction opposite to arrow 24. In this way, the axial position of the heater tube 5 is adjusted by tightening or loosening the set screw 11.

[0025] This allows the position of the positioning pin 7 on the heater tube 5 to be moved, which in turn moves the position of the ladder member 6, and thus allows the position of the glass substrate 3 placed on the ladder member 6 to be adjusted.

[0026] A molded bellows can be used for the bellows structure 12. The bellows 12 is formed in a substantially cylindrical shape to act as a partition to prevent leakage of the atmosphere inside the chamber 2, and is effective when adjusting the misalignment of the heater tube 5. It is preferable to use a movable molded bellows for the bellows 12 so that the distance between the housing cover 10 and the housing 9 can be adjusted with the set screw 11 without disassembling the housing that fixes the heater tube 5. The bellows 12 and O-rings 14 and 19 maintain the sealing of the atmosphere inside the chamber 2 so that gas does not escape from inside the chamber 2 to the outside.

[0027] The basic structure of the bellows 12 is a welded bellows, taking into consideration corrosion resistance and heat resistance, given that the solvent generated in the PI cure is NMP (N-methylpyrrolidone, N-methyl-2-pyrrolidone) and the processing temperature is around 500°C. The material can be SUS316, Hastelloy, etc.

[0028] In the comparative example before modification shown in Figure 8, the O-ring 19 is located on the outside of the housing 99, whereas in the modified embodiment shown in Figure 6, it is located inside the housing cover 10. In this way, because the housing cover 10 and the housing 9 are integrated by the bellows design, the position of the O-ring 19, which serves as an airtight seal for the heater tube 5, has been changed.

[0029] For example, as shown in Figures 5 and 6, a retaining ring 23 is fitted to the end of the heater 4. The heater housing 20, which secures the end of the heater 4, is fixed to the housing cover 10 by fixing screws 21. The heater terminal 25 is connected to the end face of the heater 4. Then, the heater cable 22 is connected to the heater terminal 25.

[0030] Thus, according to this embodiment, since the axial position of the heater tube 5 is adjusted by turning the set screw 11, there is no need to disassemble the chamber 2 that fixes the heater tube 5. Therefore, there is no need to lower the temperature of the chamber 2, and the MTTR can be shortened. As a result, it is expected that the MTTR for correcting the misalignment of the ladder member 6 according to this embodiment will be reduced by about 60% (currently 20 hours → adopted in this embodiment, 8 hours). In this way, the axial misalignment of the heater tube 5 relative to the chamber 2 of the heat treatment apparatus 1 can be corrected without disassembling the chamber 2.

[0031] Furthermore, by adjusting with the set screw 11, there is no misalignment during tightening, and adjustments can be easily made in millimeter increments, making it possible to fine-tune before large positional deviations occur.

[0032] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0033] 1. Heat treatment apparatus 2. Chamber 3. Glass substrate (to be heat treated) 4. Heater 5. Heater tube 6. Ladder members (support members, long members) 7. Positioning pins (positioning members) 8. Position adjustment mechanism 9. Housing (fixed member) 10. Housing cover (movable member) 11. Set screw (adjustment member) 12. Bellows (expansion member)

Claims

1. A heat treatment apparatus comprising: a chamber for housing a heat treatment object; a heater located at least partially within the chamber; a heater tube covering the heater and having both ends located outside the chamber; a support member for supporting the heat treatment object within the chamber; a positioning member provided on the heater tube for positioning the support member relative to the heater tube; and a position adjustment mechanism provided on at least one of the ends of the heater tube for adjusting the relative position between the chamber and the heater tube in the axial direction of the heater tube.

2. The heat treatment apparatus according to claim 1, wherein the position adjustment mechanism comprises a fixing member fixed to the outer wall of the chamber, a movable member fixed to the end of the heater tube and movable relative to the fixing member, and an adjustment member for adjusting the positional relationship of the movable member with respect to the fixing member.

3. The heat treatment apparatus according to claim 2, wherein the adjusting member is capable of adjusting the range in which the movable member can move relative to the fixed member.

4. The heat treatment apparatus according to claim 2 or 3, wherein the adjusting member includes a set screw that screws into the movable member and whose tip abuts against the fixed member.

5. The heat treatment apparatus according to any one of claims 2 to 4, wherein the position adjustment mechanism further comprises an expansion member located between the fixed member and the movable member, which generates a force in a direction that widens the distance between the fixed member and the movable member.

6. The heat treatment apparatus according to claim 5, wherein the expansion member includes a bellows.

7. The heat treatment apparatus according to any one of claims 1 to 6, comprising at least two sets of the heater and the heater tube, wherein the support member is provided spanning at least two of the heater tubes.

8. The heat treatment apparatus according to any one of claims 1 to 7, wherein the support member comprises a plurality of elongated members that straddle the at least two heater tubes.

9. The heat treatment apparatus according to any one of claims 1 to 8, wherein two positioning members are provided for one heater tube, and the support member is placed between the two positioning members.

10. The heat treatment apparatus according to any one of claims 1 to 9, wherein the position adjustment mechanism is provided at both ends of the heater tube.

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