vacuum drying equipment

Abstract

This invention provides a vacuum drying apparatus that can uniformize the vacuum drying interval within the substrate surface, thereby suppressing uneven drying of the coated film. The vacuum drying apparatus includes: a top plate having an opposing surface facing the upper surface of a substrate supported by a substrate support; a top plate lifting unit that, within a processing space, moves the top plate between a position below the opposing surface near the upper surface of the substrate supported by the substrate support and an upper position further above the lower position; and a plurality of pressing pins mounted on the opposing surface, which, when the top plate is in the lower position, abut against the peripheral region of one of the main surfaces to correct substrate warping. This allows the distance (vacuum drying interval) between the corrected upper surface of the substrate and the opposing surface to be uniform within the substrate surface.

Description

Technical Field

[0001] The present invention relates to a reduced-pressure drying device for drying a coating film formed on a substrate. Prior Art

[0002] One of the manufacturing processes for semiconductor devices involves applying a coating liquid to the surface of a substrate to form a coating film, which is then dried to form a functional film such as a resist or protective film on the substrate surface. Furthermore, in recent years, there has been a significant demand for smaller and thinner devices in the semiconductor device field. To meet this demand, fan-out panel-level packaging technology (FOPLP), which uses substrates to manufacture semiconductor packages, has attracted considerable attention. When manufacturing semiconductor packages using FOPLP technology, the coating film applied to the substrate surface is dried before the substrate undergoes the exposure and development steps. As an example of a substrate processing device that performs this drying process, as described in Patent Document 1, a vacuum drying device is used to depressurize the space surrounding the substrate on which the coating film is formed, thereby volatilizing the solvent components. In this device, a substrate is placed on the upper surface of a substrate mounting platform, and a rectifying plate is positioned above the substrate. By controlling the distance from the lower surface of the rectifying plate (equivalent to the "facing surface of the top plate portion" of the present invention) to the upper surface of the substrate (substrate surface) (hereinafter referred to as the "reduced pressure drying gap"), the evaporation rate of the solvent component from the coating film formed on the substrate is uniformly adjusted within the substrate surface. [Prior art literature] [Patent Document]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2022-38284 Summary of the Invention

[0004] [Problems to be solved by the invention]

[0005] Semiconductor package substrates tend to warp significantly due to factors such as the material used. Consequently, when the substrate is placed on the substrate mounting platform, the periphery of the substrate may be positioned higher than the center. This warping is also a problem with other substrates. Due to this warping, the gaps within the substrate surface become uneven during reduced-pressure drying. Consequently, uneven drying of the coating film occurs.

[0006] The present invention is made in view of the above-mentioned problems, and its object is to provide a vacuum drying device that can make the gap during vacuum drying uniform within the substrate surface and suppress the occurrence of uneven drying of the coating film. [Methods to solve the problem]

[0007] One form of the present invention is a reduced-pressure drying device, characterized in that it includes: a chamber having a processing space capable of accommodating a substrate, wherein the substrate has a coating film formed in a central area of one of its main surfaces; a substrate support portion, which supports the substrate in the processing space in a posture in which the coating film faces upward; an exhaust portion, which exhausts the processing space; a top plate portion having an opposing surface facing the upper surface of the substrate supported by the substrate support portion; a top plate lifting portion, which lifts and lowers the top plate portion between a lower position and an upper position higher than the lower position in the processing space, wherein the lower position is a position in which the opposing surface is close to the upper surface of the substrate supported by the substrate support portion; and a plurality of pressing pins installed on the opposing surface, which abut against the peripheral area of one of the main surfaces when the top plate portion is in the lower position.

[0008] In the present invention, the top plate portion has a facing surface that faces the upper surface of the substrate supported by the substrate support portion. Therefore, by controlling the distance from the facing surface to the upper surface of the substrate, i.e., the reduced-pressure drying gap, the evaporation rate of the solvent from the coating film formed on the substrate can be controlled. Here, if the peripheral portion of the substrate warps upward, the reduced-pressure drying gap within the substrate surface becomes uneven. Therefore, in the present invention, when the top plate portion, which has a plurality of pressing pins provided on the peripheral portion of the facing surface, is lowered to a lower position, the pressing pins contact the peripheral region of one of the main surfaces of the substrate, thereby correcting the warping of the substrate. [Effects of the Invention]

[0009] As described above, in the present invention, a top plate portion having a facing surface facing the upper surface of a substrate supported by a substrate support portion is configured to correct substrate warpage using a plurality of pressing pins provided on the periphery of the facing surface. Consequently, the distance between the corrected upper surface of the substrate and the facing surface (the gap during reduced pressure drying) can be made uniform across the substrate surface. Simple diagram description

[0010] FIG1 is a diagram showing a first embodiment of a reduced-pressure drying apparatus according to the present invention. FIG2 is a perspective view showing the arrangement relationship between a chamber and a substrate support portion in the reduced-pressure drying apparatus shown in FIG1 . FIG3A is a perspective view of the top plate portion as viewed from obliquely above. FIG3B is a perspective view of the top plate portion as viewed obliquely from below. FIG4 is a side sectional view showing the structure and adjustment operation of the top plate portion. FIG5 is a flow chart showing the reduced-pressure drying operation performed by the reduced-pressure drying apparatus of the present invention. FIG6A is a diagram illustrating an operation of carrying in a substrate in the reduced-pressure drying apparatus shown in FIG1 . FIG6B is a diagram illustrating a chamber closing operation in the reduced-pressure drying apparatus shown in FIG1 . FIG6C is a diagram showing substrate correction and initial reduced-pressure drying operations in the reduced-pressure drying apparatus shown in FIG1 . FIG6D is a diagram showing a main reduced-pressure drying operation in the reduced-pressure drying apparatus shown in FIG1 . 7A is a perspective view of a top plate portion viewed obliquely from above in a second embodiment of the reduced-pressure drying apparatus according to the present invention. 7B is a plan view of the top plate portion as viewed obliquely from below in the second embodiment of the reduced-pressure drying apparatus of the present invention. FIG8 is a diagram showing a portion of a third embodiment of the reduced-pressure drying apparatus of the present invention. Implementation Method

[0011] Figure 1 shows a first embodiment of the vacuum drying apparatus of the present invention. More specifically, Figure 1 combines a cross-sectional view showing the structure of the main components of the vacuum drying apparatus 1, which is the first embodiment of the present invention, with a block diagram of the control system for these components. Furthermore, in the following figures, to clarify the arrangement of the various components of the apparatus, as shown in Figure 1, a right-handed XYZ coordinate system is used. The XY plane represented by this coordinate system represents the horizontal direction, and the Z direction represents the vertical direction. In particular, the (-Z) direction represents the vertical downward direction.

[0012] The reduced-pressure drying apparatus 1 can be used, for example, as part of the panel-level package (PLP) manufacturing process, treating a rectangular substrate S with a coating film F formed on its surface using a processing liquid. Specifically, the reduced-pressure drying apparatus 1 receives the substrate S while the coating film F is still wet, heats the substrate S, and reduces the pressure in the surrounding area, thereby volatilizing the solvent in the coating film and drying and curing the coating film. This substrate treatment is hereinafter referred to as "heating and reduced-pressure drying."

[0013] As the substrate S, for example, a glass substrate for semiconductor packaging that has a rectangular shape when viewed from above and has semiconductor chips, wiring, etc. laminated on its surface can be used. Alternatively, as the coating film F, a photoresist film can be used, for example. Furthermore, the substrate material and coating film type are not limited to these. For example, substrates used in the manufacture of semiconductor devices or display devices other than semiconductor packages can also be processed.

[0014] The reduced-pressure drying apparatus 1 mainly comprises a chamber 10, a substrate support 20, an exhaust unit 30, a top plate 40, a top plate lift 50, a group of pressing pins 60, and a control unit 90. The chamber 10 receives a substrate S having a coating film F formed on its upper surface Sa and performs a predetermined process thereon. The exhaust unit 30 is connected to the processing space (denoted by the symbol SP in Figures 6B to 6D described later) of the chamber 10 and exhausts the processing space. The control unit 90 includes a central processing unit (CPU) 91. The CPU 91 executes a predetermined control program to control the operation of each component of the apparatus, thereby implementing the various processes described below. The dashed arrows in Figure 1 indicate the flow of control signals from the control unit 90 to the various components of the apparatus.

[0015] FIG2 is a perspective view showing the arrangement of the chamber and substrate support in the reduced-pressure drying apparatus shown in FIG1 . The chamber 10 has the following functions: forming a processing space (symbol SP in FIG6B - FIG6D ) for reducing the pressure around the substrate S, preventing the evaporation of solvent components volatilized during processing, and suppressing heat dissipation and improving energy efficiency by covering the heated substrate S. To achieve these goals, the chamber 10 has a box-shaped structure composed of a cover 11 and a bottom plate 12 combined via a sealing member 13. More specifically, the cover 11, which has a hollow cavity with an opening at the bottom, seals the upper portion of the roughly flat bottom plate 12, thereby forming a processing space between the cover 11 and the bottom plate 12. The cover 11 and the bottom plate 12 are formed of a metal material such as stainless steel or aluminum. Furthermore, the sealing member 13 is formed of an elastic material such as rubber.

[0016] The cover 11 is supported by a support mechanism (not shown) so that it can be raised and lowered in the vertical direction (Z direction). The chamber drive 93 provided in the control unit 90 raises and lowers the cover 11 in the Z direction. This opens and closes the chamber 10. Specifically, when the cover 11 is positioned downward as shown in FIG1 , the chamber 10 is sealed by the chamber drive 93, forming a processing space within. Meanwhile, when the cover 11 is moved upward by the chamber drive 93 , as shown in FIG1 and FIG2 , the cover 11 separates from the bottom plate 12, opening the processing space. When the cover 11 is closed ( FIG6B-6D ), substrates S are processed. When the cover 11 is open ( FIG1 , FIG2 , FIG6A ), substrates S can be removed and inserted, and maintenance work on internal components can be performed.

[0017] Furthermore, planar heaters H are mounted on the outer surface of the cover 11. Each heater H is electrically connected to the heater driver 92 of the control unit 90. Thus, the heaters H are activated by the heater driver 92, enabling heating of the substrate S while the cover 11 is closed. While so-called panel heaters are used as the heaters H in this embodiment, strip heaters or linear heaters may also be used. Furthermore, the mounting location of the heaters H is not limited to the outer surface of the cover 11; they may also be mounted on the inner surface or incorporated into the cover 11.

[0018] As shown in Figures 1 and 2, a substrate support portion 20 is provided on the upper surface of the bottom plate portion 12. The substrate support portion 20 has multiple (in this embodiment, four) base support members 21 extending from the upper surface of the bottom plate portion 12, surrounding the exhaust through-hole 12a provided in the center of the bottom plate portion 12. These base support members 21 support a base member 22. Furthermore, the base member 22 has a planar dimension wider than the substrate S, and multiple support pins 23 extend from its upper surface. In this embodiment, as shown in Figure 2, 16 support pins 23 are arranged in a 4×4 matrix when viewed from above, enabling horizontal support of the substrate S from below, with the coating film F facing upward.

[0019] The exhaust pipe 31 of the exhaust section 30 is connected to the exhaust through-hole 12a. In addition to the exhaust through-hole 12a, the bottom plate 12 is also provided with a cleaning through-hole 12b. Furthermore, the cleaning pipe 32 of the exhaust section 30 is connected to the cleaning through-hole 12b. The exhaust pipe 31 is connected to an exhaust line (not shown) via an exhaust valve 33 and a pump 34. Furthermore, the cleaning pipe 32 is connected to a cleaning gas source (not shown) via a cleaning valve 35.

[0020] The exhaust section 30 is controlled by the environmental control section 94 of the control unit 90. Specifically, the exhaust valve 33 and pump 34 operate in response to a control signal from the environmental control section 94 to exhaust the gas within the chamber 10, thereby reducing the pressure in the processing space. Furthermore, the purge valve 35 operates in response to a control signal from the environmental control section 94 to introduce purge gas from an external gas source into the processing space. In this manner, the exhaust section 30 operates in response to a control signal from the environmental control section 94 to control the environment within the processing space. Then, under this controlled environment, a reduced-pressure drying process is performed. Furthermore, in this embodiment, a top plate 40 is provided to regulate the evaporation rate of the solvent from the coating film F formed on the substrate S during the reduced-pressure drying process.

[0021] FIG3A is a perspective view of the top plate portion and the substrate as viewed from above. FIG3B is a perspective view of the top plate portion as viewed from below. As shown in FIG1 and FIG3A , the top plate portion 40 is configured to cover, from above, the substrate S on which the coating film F is formed in the central area Sa2 of the upper surface, excluding the peripheral area Sa1 of the upper surface. The top plate portion 40 includes: a lower top plate 41, the lower surface of which functions as a facing surface 41a that is substantially parallel to the upper surface Sa of the substrate S; and an upper top plate 42, which is configured directly above the lower top plate 41. The facing surface 41a of the lower top plate 41 is larger than the planar dimensions of the substrate S. When positioned directly above the substrate S by the top plate lifting portion 50, the facing surface 41a covers the entire substrate when viewed from above.

[0022] An upper top plate 42 is positioned directly above the lower top plate 41. As shown in Figure 3A, the upper top plate 42 has the same planar dimensions as the lower top plate 41. To reduce the weight of the upper top plate 42, a punched-out portion is provided in the upper top plate 42, excluding the central portion and peripheral portion. A lifting shaft 51 of the top plate lifting unit 50 is connected to the central portion of the upper surface of the upper top plate 42. Furthermore, the upper top plate 42 and the lower top plate 41 are connected and integrated with each other by four connecting members 43, while being slightly separated in the vertical direction Z. Furthermore, the lifting shaft 51 is mounted on the cover 11 so that it can be raised and lowered in the vertical direction Z, and the lifting mechanism 52 for raising and lowering the lifting shaft 51 is fixedly mounted on the cover 11. Therefore, when the cover 11 is raised or lowered by the chamber drive unit 93 of the control unit 90, the top plate lifting unit 50 and the top plate 40 are raised and lowered integrally therewith. For example, when the cover 11 moves upward, the top plate 40 is positioned upwardly away from the substrate support 20 and the substrate S supported by the substrate support 20, as shown in FIG1. Conversely, when the cover 11 moves downward, the top plate 40 approaches the substrate S.

[0023] Furthermore, in this embodiment, a pressing pin group 60 and a top plate lifting unit 50 are provided to correct the warping of the substrate S and precisely adjust the gap between the substrate S and the lower top plate 41 in the vertical direction Z. The pressing pin group 60 is composed of a plurality of pressing pins 61, projecting downward from the facing surface 41a of the lower top plate 41. In this embodiment, to press the upper edge of the substrate S, ten pressing pins 61 are detachably mounted on the lower surface (facing surface 41a) of the lower top plate 41, facing the upper edge of the substrate S, along one side of the upper edge. Therefore, a total of 40 pressing pins 61 are provided facing the upper edge of the substrate S.

[0024] In the top plate lifting unit 50 , the lifting mechanism 52 operates in response to a lifting instruction from the top plate position control unit 95 of the control unit 90 , thereby displacing the lifting shaft 51 in the vertical direction Z.

[0025] The upper top plate 42, lower top plate 41, connecting member 43, and top plate lifting unit 50 constructed in this manner are raised and lowered integrally with the cover 11 in the vertical direction Z. Therefore, even when the top plate lifting unit 50 is stopped, for example, when the cover 11 is lowered by the chamber drive unit 93, the top plate 40 comes to a stop close to the substrate S. Here, if the peripheral edge of the substrate S is significantly warped upward, several pressing pins 61 may contact the peripheral edge of the substrate S midway, pressing the peripheral edge of the substrate S to correct the warping (see FIG. 6B described later). Alternatively, if the warping of the substrate S is relatively small, all the pressing pins 61 may be moved upward away from the peripheral edge of the substrate S when the cover 11 stops descending.

[0026] After the cover 11 stops descending, if only the top plate 40 (= lower top plate 41 + upper top plate 42 + connecting member 43) descends in response to the descending command from the top plate position control unit 95, the gap between the lower top plate 41 and the substrate S narrows, and the central area of the facing surface 41a of the lower top plate 41 approaches a position directly above the upper surface Sa of the substrate S, thereby covering it from above with the coating film F. Furthermore, all the pressing pins 61 press the peripheral edge of the upper surface of the substrate S downward along the entire circumference. Therefore, the gap between the lower top plate 41 and the substrate S is consistent with the amount of protrusion of the pressing pins 61 from below the facing surface 41a, and the warping of the substrate S can be corrected within the substrate surface.

[0027] Furthermore, in this embodiment, to prevent interference between the connecting members 43 and the substrates S during the lifting and lowering movement of the top plate 40, four connecting members 43 are installed near the peripheral corners of the lower top plate 41 and the upper top plate 42, as shown in Figures 3A and 3B. More specifically, four connecting members 43 are provided in the area outside the overlapping region (the area enclosed by the dashed line in Figure 3B) where the substrates S overlap when viewed from above. Furthermore, one of the four connecting members 43 is a fixed connecting member 43a that connects the lower top plate 41 and the upper top plate 42 with a collar (not shown) positioned between them. The remaining three connecting members 43b are push-pull bolts 43b used to adjust the gap between the lower top plate 41 and the upper top plate 42. This allows the operator to easily and accurately adjust the horizontal position of the lower top plate 41. This adjustment operation is described with reference to Figure 4.

[0028] Figure 4 is a schematic diagram illustrating the process for adjusting the position of the lower top plate. As shown in column (a) of Figure 4 , if the lower top plate 41 of the top plate portion 40 is tilted relative to the upper top plate 42, the gap during drying, i.e., the gap during reduced-pressure drying, varies within the surface of the substrate S, making uniform reduced-pressure drying difficult. This tilting of the lower top plate 41 can occur during the initial assembly of the device or due to aging. Therefore, in this embodiment, horizontal adjustment is performed when the reduced-pressure drying device 1 is not in operation, such as during assembly, factory installation, and maintenance. More specifically, the operator adjusts the lower top plate 41 to a horizontal position, as shown in column (b) of Figure 4 . With the lower top plate 41 thus adjusted, the heated reduced-pressure drying process is performed in the following sequence.

[0029] Figure 5 is a flow chart illustrating the flow of the heating and reduced-pressure drying process performed by the reduced-pressure drying apparatus shown in Figure 1 . Furthermore, Figures 6A to 6D schematically illustrate the operation of various components of the apparatus during the heating and reduced-pressure drying process. This process is achieved by the CPU 91 of the control unit 90 executing a pre-prepared control program and causing the various components of the apparatus to perform predetermined operations. The cover 11 is previously heated to a predetermined temperature by the operation of the heater H (step S11).

[0030] Furthermore, as shown in FIG6A , the chamber drive unit 93 causes the cover unit 11, the top plate lift unit 50, and the top plate unit 40 to rise integrally, forming a carry-in / carry-out space for carrying substrates S in and out. Subsequently, the unprocessed substrate S (i.e., carrying the undried coating film F) held by the hand HD of an external transfer robot is moved through the carry-in / carry-out space to a position above the support pins 23. Thereafter, as indicated by the arrows in FIG6A , the hand HD descends, transferring the substrate S to the support pins 23 (step S12). Furthermore, the loading and unloading of substrates S is not limited to the use of a transfer robot; any method using a suitable transfer mechanism capable of horizontal transfer may be employed.

[0031] When the substrate S is loaded as described above, the hand HD retreats from the loading / unloading space. Subsequently, the chamber drive unit 93 lowers the cover 11, the top plate lifting unit 50, and the top plate 40 as a whole (step S13). As a result, the cover 11 is in close contact with the bottom plate 12 via the sealing member 13, forming a closed processing space SP. At this point, the top plate 40 is located at an upper position Pup, which is upwardly spaced from the substrate S supported by the support pins 23. The upper position Pup is a position suitable for subsequent reduced pressure drying, and refers to a height position vertically upwardly spaced from the upper surface Sa of the substrate S by the gap GP during the reduced pressure drying process.

[0032] The periphery of the substrate S may warp upward. When the amount of warping is zero or relatively small, the pressing pins 61 of the top plate 40 do not contact the periphery of the upper surface of the substrate S. On the other hand, as shown in Figure 6B , when the amount of warping is relatively large, a portion of the pressing pins 61 may contact the periphery of the upper surface of the substrate S, pressing it downward. However, even in this case, the pressing pins 61 often move upward away from the substrate S.

[0033] Next, only the top plate 40 (= lower top plate 41 + upper top plate 42 + connecting member 43) descends to a lower position Pdw below the upper position Pup in response to a descending command from the top plate position control unit 95. At this point, as shown in FIG6C , all pressing pins 61 abut and press against the upper surface peripheral area Sa1 of the substrate S, thereby correcting the warpage of the substrate S (step S14). Simultaneously, the environmental control unit 94 begins decompressing the processing space SP (step S15).

[0034] In this embodiment, during the initial stages of straightening and vacuum drying of the substrate S (hereinafter referred to as the "initial drying period"), the environmental control unit 94 adjusts the exhaust volume to prevent a decrease in the drying quality of the coating film F due to rapid volatilization of the solvent components in the coating film F. Specifically, during the initial drying period, the drying rate of the coating film F is suppressed, and the exhaust rate (exhaust volume per unit time) is also suppressed until the solvent content in the coating film F falls below a predetermined value, reaching a state known as semi-dry or partially dried. In this specification, exhaust in this state, where the exhaust volume by the exhaust unit 30 is suppressed as described above, is referred to as "slow exhaust." The exhaust volume in slow exhaust corresponds to an example of the "first exhaust volume" of the present invention. On the other hand, as described later, exhaust at a higher exhaust rate than slow exhaust to increase the vacuum drying rate is referred to as "main exhaust." The exhaust volume in main exhaust corresponds to an example of the "second exhaust volume" of the present invention.

[0035] After the initial drying period has elapsed ("YES" in step S16), as shown in Figure 6D, the top plate position control unit 95 raises only the top plate portion 40 (=lower top plate 41 + upper top plate 42 + connecting member 43) to the upper position Pup (step S17). This process is an example of the "top plate raising process" of the present invention. As a result, the reduced-pressure drying gap GP becomes a preset value. Furthermore, through this correction process, the gap with the facing surface 41a of the lower top plate 41, i.e., the reduced-pressure drying gap GP, becomes uniform within the plane of the upper surface Sa. Then, in this state, the environmental control unit 94 switches from slow exhaust to main exhaust, rapidly evaporating the remaining solvent components of the coating film F (step S18). This allows the solvent evaporation rate to be adjusted with relatively high and excellent in-plane uniformity. As a result, the coating film F on the substrate S can be dried with excellent quality while shortening the reduced-pressure drying time.

[0036] After the period (hereinafter referred to as the "main drying period") during which the coating film F is subjected to reduced pressure drying by main exhaust while the lower top plate 41 is positioned at the desired upper position Pup as described above, until the solvent concentration in the coating film F reaches or below a predetermined value ("YES" in step S19), the exhaust unit 30 stops exhausting. Subsequently, the reduced pressure in the processing space SP is released by introducing a cleaning gas (step S20). The cover unit 11 then moves upward to a position (shown in FIG. 6A ) where substrates S can be loaded and unloaded (step S21), opening the processing space SP to the substrates S. Subsequently, the dried substrates S are unloaded to the outside by receiving an external transfer robot (step S22).

[0037] If there is a next substrate S to be processed ("Yes" in step S23), the process returns to step S12 to receive a new substrate S and perform the same process as described above. On the other hand, if there is no new substrate S ("No" in step S23), the process ends after a predetermined ending operation.

[0038] As described above, according to the first embodiment, a plurality of pressing pins 61 are provided around the periphery of the facing surface 41a of the lower top plate 41. Furthermore, before performing reduced-pressure drying with the facing surface 41a facing the upper surface Sa of the substrate S, the top plate 40 is positioned at the lower position Pdw, and the plurality of pressing pins 61 correct the warping of the substrate S. Consequently, the distance between the upper surface Sa of the substrate S and the facing surface 41a after correction, i.e., the reduced-pressure drying gap GP, can be uniformed across the substrate surface. As a result, even for warped substrates S, drying processes involving reduced pressure and heating can be successfully performed.

[0039] Furthermore, in this embodiment, the four connecting members 43, one fixed connecting member 43a and three push-pull bolts 43b, are positioned at different locations within the surface of the lower top plate 41. Therefore, even if the lower top plate 41 is tilted relative to the horizontal plane, as shown in FIG4(a), adjustment using the three push-pull bolts 43b can still return the lower top plate 41 to a horizontal position, as shown in FIG4(b). This allows for superior warpage correction and even gap GP within the substrate surface during reduced-pressure drying.

[0040] In this embodiment, three push-pull bolts 43b are used as connecting members for adjusting the gap between the upper top plate 42 and the lower top plate 41. However, adjustment can also be performed using connecting members other than the push-pull bolts 43b. Furthermore, the number of connecting members is not limited to three.

[0041] In addition, when the top plate 40 is viewed from above, the connecting member 43 is located outside the substrate S supported by the substrate support 20. Therefore, interference between the connecting member 43 and the substrate S during the vertical movement of the top plate 40 can be effectively prevented.

[0042] Furthermore, each pressing pin 61 is freely attachable and detachable to the lower top plate 41. Therefore, it is possible to prepare a variety of pressing pins 61 with varying amounts of downward protrusion from the lower top plate 41, and change the type of pressing pin 61 attached to the lower top plate 41 according to the thickness of the substrate S. This allows for adaptability to a variety of substrate S types and formulations, thereby enhancing the versatility of the reduced-pressure drying apparatus 1. Alternatively, the top plate position control unit 95 can be used to appropriately change the lower position Pdw of the top plate 40, rather than changing the type of pressing pin 61.

[0043] Furthermore, in this embodiment, the reduced-pressure drying process is performed in two stages: an initial reduced-pressure drying process (steps S14 and S15) and a main reduced-pressure drying process (steps S18 and S19). This effectively prevents problems such as rapid evaporation of the solvent from the coating film F during the straightening process, which could damage the uniformity of the coating film F. The coating film F can be dried under reduced pressure with excellent quality.

[0044] As described above, in the first embodiment, the upper surface Sa of the substrate S corresponds to "one of the main surfaces" of the present invention, and the upper surface peripheral region Sa1 and the upper surface central region Sa2 correspond to the "peripheral region" and "central region" of the present invention, respectively. Furthermore, the initial drying period and the main drying period correspond to examples of the "first predetermined time" and "second predetermined time," respectively, of the present invention.

[0045] Figures 7A and 7B are, respectively, a perspective view and a plan view of a second embodiment of the reduced-pressure drying apparatus of the present invention, viewed from below. The second embodiment differs significantly from the first embodiment in the addition of two alignment pin pairs, each consisting of two alignment pins 45. The remaining structure is identical to the first embodiment. One pair of alignment pins is located at a corner of the overlapping region (the region enclosed by the dashed line in Figure 7B ) where the substrates S overlap when viewed from below, and the other pair of alignment pins is located at a corner diagonally opposite to the corner. Furthermore, when the amount of downward protrusion from the facing surface 41a of each alignment pin 45 is compared with that of the pressing pin 61, the amount of downward protrusion from each alignment pin 45 is greater than that of the pressing pin 61. The tip of the alignment pin 45 is machined to taper downward. Therefore, when the top plate 40 is lowered in step S14, the alignment pin 45 also descends with it. Furthermore, before the pressing pins 61 contact the substrate S, the tips of the alignment pins 45 contact the corners of the substrate S, positioning the substrate S in the substrate posture specified by the two pairs of alignment pins. Subsequently, the substrate S is pressed by the multiple pressing pins 61, correcting its warping. This allows the substrate S to be consistently dried under reduced pressure in the specified position and with its warping corrected, enabling more stable and high-quality drying. In the second embodiment, two pairs of alignment pins are used, but three or more pairs may also be used. Furthermore, while the alignment pins 45 are positioned corresponding to the corners of the substrate S, alignment pins that engage with other locations to position the substrate S may also be used.

[0046] Furthermore, the present invention is not limited to the above-described embodiment and can be modified in various ways without departing from the main purpose. For example, in the above-described embodiment, the top plate portion 40 is composed of the lower top plate 41 and the upper top plate 42. However, as shown in FIG8 , the top plate portion 40 can also be composed solely of the lower top plate 41 (third embodiment). In other words, the lower surface of the lower top plate 41 can function as the "facing surface" of the present invention, and the upper surface of the lower top plate 41 can be connected to the lifting shaft 51.

[0047] In addition, in the embodiment, the lower surface of the substrate S is supported by 16 support pins 23, and the upper surface peripheral area Sa1 of the substrate S is pressed by 40 pressing pins 61, but the number or arrangement of the support pins 23 and the pressing pins 61 can be appropriately changed for application.

[0048] Furthermore, in the above-described embodiment, the opening and closing of the processing space SP are switched by the lifting and lowering of the cover portion 11 , but the above-described switching may be performed by the lifting and lowering of the bottom plate portion 12 or by the lifting and lowering of both.

[0049] [Industrial Applicability]

[0050] The present invention relates to a reduced-pressure drying device for drying a coating film formed on a substrate.

[0051] 1: Reduced pressure drying device 10: Chamber 11: Hood 12: Bottom plate 12a: Through hole for exhaust 12b: Through hole for cleaning 13: Sealing member 20: substrate support 21: Base support member 22: Base component 23: Support pin 30: Exhaust 31: Exhaust pipe 32: Cleaning pipe 33: Exhaust valve 34: Pump 35: Cleaning valve 40: Top plate 41: bottom top plate 41a: facing surface (of the lower top plate) 42: Top plate 43: Connecting members 43a: Fixed connecting member 43b: Push-pull bolt 45: Alignment pin 50: Top plate lifting part 51: Lifting axis 52: Lifting mechanism 60: Press pin group 61: Press pin 90: Control Department 91:CPU 92: Heater drive unit 93: Chamber drive unit 94: Environmental Control Department 95: Top plate position control unit F: coating film GP: vacuum drying time gap H: Heater HD:Hand Pdw: lower position Pup: upper position S:Substrate S11, S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23: Steps Sa: Upper surface (of substrate) Sa1: Upper surface peripheral area Sa2: Central area of the upper surface SP: Processing Space X, Y, Z: coordinate axes

Claims

1. A vacuum drying apparatus, characterized in that it comprises: A chamber having a processing space capable of accommodating a substrate, wherein a coating film is formed in the central region of one of its main surfaces; A substrate support portion, within the processing space, supports the substrate in an upward-facing posture with the coated film facing upward; an exhaust portion, vents the processing space; a top plate portion, having an opposing surface facing the upper surface of the substrate supported by the substrate support portion; a top plate lifting portion, within the processing space, allows the top plate portion to move up and down between a lower position and an upper position, the lower position being a position where the opposing surface is close to the upper surface of the substrate supported by the substrate support portion; and a plurality of pressing pins, mounted on the opposing surface, abutting against the peripheral region of one of the main surfaces when the top plate portion is in the lower position, the top plate portion comprising: an upper top plate, connected to the top plate lifting portion; and a lower top plate, having the opposing surface and disposed below the upper top plate; The upper top plate and the lower top plate are connected by multiple connecting structural members at different positions within the surface of the lower top plate. At least a portion of the multiple connecting structural members are capable of adjusting the interval between the upper top plate and the lower top plate.

2. The vacuum drying apparatus as described in claim 1, wherein, When viewed from above, the plurality of connecting structural members are located further outward than the substrate supported by the substrate support.

3. The vacuum drying apparatus as described in claim 1 or claim 2, wherein, The plurality of pressing pins are detachable from the lower top plate.

4. The pressure-reducing drying apparatus as described in claim 1 or claim 2 further includes a control unit, which controls the lifting and lowering of the top plate, wherein the plurality of pressing pins are freely detachable from the lower top plate, and the control unit adjusts the amount of descent of the top plate from the upper position based on the amount of protrusion of the plurality of pressing pins mounted on the lower top plate from the opposing surfaces downward.

5. The vacuum drying apparatus as claimed in claim 1 or claim 2 further includes a plurality of alignment pins and a chamber drive unit, the plurality of alignment pins being suspended from the opposing surface toward the end face of the substrate supported by the substrate support unit, the chamber having a bottom plate portion and a cover portion, the cover portion being lowered by the chamber drive unit to close the upper part of the bottom plate portion and form the processing space, the alignment pins being longer than the pressing pins in terms of downward protrusion from the opposing surface, and the front end of the alignment pins engaging with the end face of the substrate before the pressing pins abut against the peripheral area of ​​one of the main surfaces during the integral descent of the cover portion and the top plate portion caused by the chamber drive unit, thereby adjusting the position of the substrate in the horizontal plane.

6. The depressurized drying apparatus as claimed in claim 1 or claim 2, further comprising a control unit that controls the top plate lifting section and the exhaust section, the control unit performing the following processes: an initial depressurized drying process, controlling the top plate lifting section such that the peripheral area of ​​one of the main surfaces abuts against the plurality of pressing pins, and controlling the exhaust section such that the exhaust volume from the processing space per unit time is a first exhaust volume, while simultaneously maintaining depressurized drying of the coated film for a first predetermined time; a top plate lifting process, after the initial depressurized drying process, controlling the top plate lifting section such that the top plate section rises to the upper position; and a main depressurized drying process, controlling the exhaust section such that the exhaust volume from the processing space per unit time is a second exhaust volume greater than the first exhaust volume, while simultaneously maintaining depressurized drying of the coated film for a second predetermined time.

7. The vacuum drying apparatus as described in claim 6, wherein, After the top plate is raised, the control unit performs the main decompression drying process.

Images