Reduced pressure drying device

Abstract

To suppress generation of uneven drying of a coating film by making a gap during decompression drying uniform within a substrate surface.SOLUTION: In a decompression dryer, a plurality of pressing pins are suspended via through holes of a top plate part from a ceiling surface of a cover part toward a substrate. Lowering of the cover part causes a lower surface of the cover part to come into close contact with an upper surface of a base part so as to form a processing space, and the pressing pins abut on a peripheral edge region of one main surface of the substrate to correct warp of the substrate. While the warp is corrected by the pressing pins, an opposing surface of the top plate part opposes to the upper surface of the substrate supported by a substrate support part. Thus a distance between the upper surface of the corrected substrate and the opposing surface (gap during decompression drying) can be made uniform within the substrate surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a reduced pressure drying apparatus for drying a coating film formed on a substrate. [Background technology]

[0002] One semiconductor device manufacturing process involves applying a coating liquid to a substrate surface to form a coating film, which is then dried to form a functional film such as a resist film or a protective film on the substrate surface. In recent years, the demand for smaller and thinner devices has been increasing significantly in the semiconductor device field. To meet this demand, fan-out panel-level packaging (FOPLP), which uses substrates to manufacture semiconductor packages, has attracted attention. When manufacturing semiconductor packages using FOPLP technology, the coating film applied to the substrate surface is also dried before the substrate is subjected to an exposure and development process. As an example of an apparatus for performing this drying process, a reduced-pressure drying apparatus, as described in Patent Document 1, is used as an example of a substrate processing apparatus that reduces the pressure around a substrate on which a coating film has been formed to volatilize the solvent components. In this apparatus, the substrate is placed on the upper surface of a substrate support stage, and a rectifying plate is positioned above the substrate. By controlling the distance (hereinafter referred to as the "reduced-pressure drying gap") from the lower surface of the rectifying plate (corresponding to the "opposing surface of the top plate" in this specification) to the upper surface of the substrate (substrate surface), the evaporation rate of the solvent components from the coating film formed on the substrate is uniformly adjusted across the substrate surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-38284 Summary of the Invention [Problem to be solved by the invention]

[0004] However, warping tends to increase due to factors such as the material of the substrate used for semiconductor packaging. As a result, when the substrate is placed on the substrate placement stage, the periphery of the substrate may be positioned higher than the center. This type of warping is also becoming a problem for other types of substrates. This substrate warping causes uneven gaps across the substrate surface during reduced-pressure drying. As a result, the coating film dries unevenly.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a reduced-pressure drying apparatus that can make the gap uniform across the substrate surface during reduced-pressure drying, thereby suppressing the occurrence of uneven drying of the coating film. [Means for solving the problem]

[0006] One aspect of the present invention is a reduced-pressure drying apparatus for drying a coating film formed in a central region of one main surface of a substrate, the apparatus comprising: a chamber having a base portion and a cover portion that is movable above the base portion, with the lower surface of the cover portion coming into close contact with the upper surface of the base portion to form a processing space capable of accommodating the substrate; a substrate support portion that supports the substrate within the processing space with the coating film facing upward; a plurality of pressure pins suspended from the ceiling surface of the cover portion toward the substrate supported by the substrate support portion; an exhaust portion that evacuates the processing space; a top plate portion that has an opposing surface that faces the upper surface of the substrate supported by the substrate support portion and through holes provided for inserting the pressure pins; a top plate elevating portion that raises and lowers the top plate portion within the processing space between a lower position where the opposing surface approaches the upper surface of the substrate supported by the substrate support portion and an upper position that is higher than the lower position; and a chamber driving portion that raises and lowers the cover portion relative to the base portion while the plurality of pressure pins are suspended. Equipped with When the chamber driving section brings the lower surface of the cover section into close contact with the upper surface of the base section, the plurality of pressing pins come into contact with the peripheral region of one of the main surfaces.

[0007] In this invention, the top plate has a facing surface that faces the upper surface of the substrate supported by the substrate support. Therefore, by controlling the distance from the facing surface to the upper surface of the substrate, i.e., the vacuum drying gap, the evaporation rate of the solvent from the coating film formed on the substrate can be controlled. Here, if the peripheral edge of the substrate is warped upward, the vacuum drying gap across the substrate surface becomes uneven. Therefore, in this invention, multiple pressure pins are suspended from the ceiling surface of the cover toward the substrate through through holes in the top plate. When the cover descends, the lower surface of the cover comes into close contact with the upper surface of the base, forming a processing space, and the pressure pins come into contact with the peripheral region of one main surface of the substrate, correcting the warpage of the substrate. [Effects of the Invention]

[0008] As described above, in the present invention, when the lower surface of the cover and the upper surface of the base are brought into close contact with each other to form a processing space, the warpage of the substrate is corrected by a plurality of pressure pins suspended from the ceiling surface of the cover, and therefore the distance between the corrected upper surface of the substrate and the opposing surface (the gap during reduced pressure drying) can be made uniform across the substrate surface. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a first embodiment of a reduced pressure drying apparatus according to the present invention. [Figure 2] 2 is a perspective view showing the positional relationship between a chamber and a substrate support unit in the reduced-pressure drying apparatus shown in FIG. [Figure 3A] FIG. 2 is a perspective view of the top plate, the presser pins, and the circuit board as viewed obliquely from above. [Figure 3B] FIG. 2 is a perspective view of the top plate and the presser pins as seen obliquely from below. [Figure 4] 10A and 10B are side cross-sectional views showing the configuration and adjustment operation of the top plate portion. [Figure 5] 4 is a flowchart showing a reduced-pressure drying operation performed by the reduced-pressure drying apparatus according to the present invention. [Figure 6A] 1. FIG. 4 is a diagram showing a substrate loading operation in the reduced-pressure drying apparatus shown in FIG. [Figure 6B] 2A to 2C are diagrams illustrating the chamber closing and substrate correction operations in the reduced-pressure drying apparatus shown in FIG. [Figure 6C] 2 is a diagram showing an initial reduced pressure drying operation in the reduced pressure drying apparatus shown in FIG. 1. FIG. [Figure 6D] 2 is a diagram showing a main reduced-pressure drying operation in the reduced-pressure drying apparatus shown in FIG. 1. FIG. [Figure 7A] FIG. 10 is a perspective view of a top plate portion of a second embodiment of a reduced-pressure drying apparatus according to the present invention, viewed obliquely from above. [Figure 7B] FIG. 10 is a plan view of a top plate portion of a second embodiment of a reduced-pressure drying apparatus according to the present invention, viewed obliquely from below. [Figure 8] FIG. 10 is a diagram showing a part of a third embodiment of a reduced pressure drying apparatus according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] FIG. 1 is a diagram showing a first embodiment of a reduced-pressure drying apparatus according to the present invention. More specifically, FIG. 1 is a combination of a cross-sectional view showing the configuration of the main parts of a reduced-pressure drying apparatus 1 according to the first embodiment of the present invention and a block diagram of a control system for the same. In order to clarify the layout relationship of each part of the apparatus in each of the following figures, a right-handed XYZ Cartesian coordinate system is set as shown in FIG. 1. The XY plane shown in 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.

[0011] This reduced-pressure drying apparatus 1 can be applied to, for example, part of the manufacturing process for panel level packages (PLPs), and processes a rectangular substrate S having a coating film F made of a processing liquid formed on its surface. Specifically, the reduced-pressure drying apparatus 1 receives the substrate S with the coating film F still wet, and performs a process of volatilizing the solvent components in the coating film and drying and hardening the coating film by heating the substrate S and reducing the pressure of the surrounding space. Hereinafter, this type of substrate processing will be referred to as a "heating reduced-pressure drying process."

[0012] The substrate S may be, for example, a glass substrate for semiconductor packaging having a rectangular shape in a plan view and having semiconductor chips, wiring, etc. laminated on its surface. The coating film F may be, for example, a photoresist film. The substrate material and the type of coating film are not limited to these, and the substrate to be processed may be, for example, a substrate used in the manufacture of semiconductor devices or display devices other than semiconductor packages.

[0013] The reduced-pressure drying apparatus 1 mainly comprises a chamber 10, a substrate support unit 20, an exhaust unit 30, a top plate unit 40, a top plate lifting unit 50, a presser pin group 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 therein. The exhaust unit 30 is connected to the processing space (designated SP in FIGS. 6B to 6D, which will be described later) of the chamber 10 and exhausts the processing space. The control unit 90 includes a CPU (Central Processing Unit) 91, which executes a predetermined control program to control the operation of each unit of the apparatus and realize various processes described below. Note that the dotted arrows in FIG. 1 indicate the flow of control signals from the control unit 90 to each unit of the apparatus.

[0014] FIG. 2 is a perspective view showing the relative positions of the chamber and the substrate support unit in the reduced-pressure drying apparatus shown in FIG. 1. The chamber 10 forms a processing space (referenced SP in FIGS. 6B to 6D) for reducing the pressure around the substrate S, prevents solvent components volatilized by processing from scattering to the surroundings, and has the function of suppressing heat dissipation and improving energy efficiency by covering the periphery of the heated substrate S. For these purposes, the chamber 10 has a box-shaped structure in which a cover unit 11 and a bottom plate unit 12 are combined via a sealing member 13. More specifically, the lower surface 11a of the cover unit 11, which has a cavity with an open bottom, is in close contact with the upper surface 12a of the bottom plate unit 12, which has a substantially flat shape, via the sealing member 13, thereby closing the top of the bottom plate unit 12. This forms a processing space between the cover unit 11 and the bottom plate unit 12. The cover unit 11 and the bottom plate unit 12 are made of a metal material such as stainless steel or aluminum. The sealing member 13 is made of an elastic material such as rubber. Furthermore, the ceiling surface of the cover unit 11 is 11b As will be described later, the ceiling surface 11b is provided so as to cover the substrate S supported by the substrate support portion 20 from above via the top plate portion 40. Moreover, the area of ​​the ceiling surface 11b facing the upper surface peripheral area Sa1 of the substrate S is finished so that a presser pin 61 can be attached and detached.

[0015] The cover part 11 is supported by a support mechanism (not shown) so that it can be raised and lowered in the vertical direction (Z direction), and a chamber driver 93 provided in the controller 90 raises and lowers the cover part 11 in the Z direction as appropriate. This opens and closes the chamber 10. Specifically, the chamber driver 93 positions the cover part 11 so that the lower surface 11a of the cover part 11 is in close contact with the upper surface 12a of the bottom plate part 12 (see FIGS. 6B to 6D), thereby closing the chamber 10 and forming a processing space therein. On the other hand, the chamber driver 93 moves the cover part 11 upward, separating the cover part 11 from the bottom plate part 12 as shown in FIGS. 1 and 2, thereby opening the processing space. When the cover part 11 is in the closed state (FIGS. 6B to 6D), processing of the substrate S is performed, while when the cover part 11 is in the open state (FIGS. 1, 2, and 6A), it is possible to insert and remove the substrate S and perform maintenance work on the internal components.

[0016] Furthermore, a planar heater H is attached to the outer surface of the cover part 11. Each heater H is electrically connected to a heater driving part 92 of the control part 90. Therefore, when the heater H is operated by the heater driving part 92, it becomes possible to heat the substrate S with the cover part 11 in a closed state. Note that in this embodiment, a so-called panel heater is used as the heater H, but a strip-shaped or wire-shaped heater may also be used. Furthermore, the attachment position of the heater H is not limited to the outer surface of the cover part 11, and the heater H may also be attached to the inner surface or built into the cover part 11.

[0017] As shown in FIGS. 1 and 2, a substrate support section 20 is provided on the upper surface of the bottom plate section 12. The substrate support section 20 has a plurality of (four in this embodiment) base support members 21 standing upright from the upper surface of the bottom plate section 12 so as to surround an exhaust through-hole 12a provided in the center of the bottom plate section 12. A base member 22 is supported by these base support members 21. The base member 22 has a planar size wider than the substrate S, and a plurality of support pins 23 standing upright from its upper surface. In this embodiment, as shown in FIG. 2, 16 support pins 23 are arranged in a 4×4 matrix in a plan view from above, and can horizontally support the substrate S from below with the coating film F facing upward.

[0018] An exhaust pipe 31 of the exhaust unit 30 is connected to the exhaust through hole 12a. In addition to the exhaust through hole 12a, a purge through hole 12b is also provided in the bottom plate 12. A purge pipe 32 of the exhaust unit 30 is connected to the purge through hole 12b. The exhaust pipe 31 is connected to an exhaust line (not shown) via an exhaust valve 33 and a pump 34. The purge pipe 32 is connected to a purge gas source (not shown) via a purge valve 35.

[0019] The exhaust unit 30 is controlled by an atmosphere control unit 94 of the control unit 90. Specifically, the exhaust valve 33 and the pump 34 are operated in response to a control signal from the atmosphere control unit 94, thereby exhausting the gas inside the chamber 10 and reducing the pressure in the processing space. Furthermore, the purge valve 35 is operated in response to a control signal from the atmosphere control unit 94, thereby introducing a purge gas from an external gas source into the processing space. In this manner, the exhaust unit 30 is operated in response to a control signal from the atmosphere control unit 94, thereby controlling the atmosphere inside the processing space. Then, a reduced-pressure drying process is performed under atmosphere-controlled conditions. Furthermore, in this embodiment, a top plate 40 is provided to adjust the evaporation rate of the solvent from the coating film F formed on the substrate S during the reduced-pressure drying process.

[0020] 3A is a perspective view of the top plate portion, pressure pins, and substrate, as viewed obliquely from above. FIG. 3B is a perspective view of the top plate portion and pressure pins, as viewed obliquely from below. As shown in FIGS. 1 and 3A, the top plate portion 40 is arranged so as to cover from above the substrate S, which has a coating film F formed in a central region Sa2 of the top surface, excluding a peripheral region Sa1 of the top surface. The top plate portion 40 has a lower top plate 41, the lower surface of which functions as an opposing surface 41a that faces the upper surface Sa of the substrate S and is substantially parallel to the upper surface Sa, and an upper top plate 42 arranged directly above the lower top plate 41. The opposing surface 41a of the lower top plate 41 is larger than the planar size of the substrate S, and when positioned directly above the substrate S by the top plate lifting unit 50, it covers the entire substrate when viewed from above. In the lower top panel 41, through holes 41b are provided on the lifting paths of a plurality of pressure pins 61 suspended from the ceiling surface 11b, and the pressure pins 61 are inserted through the through holes 41b so as to be able to move up and down freely in the vertical direction Z. In this embodiment, in order to press down the upper surface peripheral region Sa1 of the substrate S, ten pressure pins 61 are detachably attached to the ceiling surface 11b of the cover part 11 so as to face the upper surface peripheral region Sa1 of the substrate S, one for each side of the upper surface peripheral region Sa1. Therefore, a total of 40 pressure pins 61 are suspended toward the upper surface peripheral region Sa1 of the substrate S.

[0021] The upper top plate 42 is disposed directly above the lower top plate 41. As shown in FIG. 3A, the upper top plate 42 has the same planar size as the lower top plate 41. To reduce the weight of the upper top plate 42 and allow some of the pressure pins 61 (hereinafter referred to as "punch-passing pins 61") to move up and down, punched portions 42a are provided in the upper top plate 42 in areas other than the central and peripheral portions. Furthermore, the peripheral portions are provided with through holes 42b on the paths of movement of the pressure pins 61 other than the punch-passing pins. Therefore, the punch-passing pins 61 constituting the pressure pin group 60 can move up and down freely via the through holes 41b and punched portions 42a, while the remaining pressure pins 61 can move up and down freely via the through holes 41b and 42b. In this manner, in this embodiment, the punched portions 42a function as an example of the "through holes" of the present invention. If punched portions 42a are not provided, then the upper top plate 42 may be provided with through holes 42b in the same number and in the same arrangement as the through holes 42b provided in the lower top plate 41.

[0022] An elevation shaft 51 of the top plate elevation unit 50 is connected to the center of the top surface of the upper top plate 42. The upper top plate 42 and the lower top plate 41 are connected to each other by four connecting members 43 while spaced apart by a small distance in the vertical direction Z, and are integrated. The elevation shaft 51 is attached to the cover unit 11 so as to be movable up and down in the vertical direction Z, and an elevation mechanism 52 for raising and lowering the elevation shaft 51 is fixedly attached to the cover unit 11. Therefore, when the cover unit 11 is raised and lowered by the chamber driving unit 93 of the control unit 90, the top plate elevation unit 50 and the top plate unit 40 are raised and lowered integrally accordingly. For example, by moving the cover unit 11 upward, the top plate unit 40 is positioned above and away from the substrate support unit 20 and the substrate S supported by the substrate support unit 20, as shown in FIG. 1 . Conversely, as the cover portion 11 moves downward, the top plate portion 40 approaches the substrate S, and the pressure pins 61 come into contact with and press against the upper surface peripheral region Sa1 of the substrate S, thereby correcting the warpage of the substrate S. To perform this correction process, as shown in the enlarged view in FIG. 3B , the tips of the pressure pins 61 always protrude downward from the through holes 41b of the lower top plate 41. In other words, while the lower surface 11a of the cover portion 11 is in close contact with the upper surface 12a of the substantially flat bottom plate portion 12 via the seal member 13 to form a processing space, the pressure pins 61 continue to abut against the upper surface peripheral region Sa1 of the substrate S, keeping the substrate S in a horizontal position.

[0023] In the tabletop lifting unit 50, the lifting mechanism 52 operates in response to a lifting command from the tabletop position control unit 95 of the control unit 90, and shifts the lifting shaft 51 in the vertical direction Z.

[0024] The upper top plate 42, lower top plate 41, connecting member 43, and top plate lifting unit 50 configured in this manner move up and down in the vertical direction Z together with the cover unit 11. Therefore, as shown in FIG. 6B , which will be described later, when the cover unit 11 is lowered with the tips of the pressure pins 61 protruding downward from the lower top plate 41 to close the chamber 10, all of the pressure pins 61 come into contact with the peripheral edge of the substrate S and press it downward to correct any warpage. In addition, the opposing surface 41 a of the lower top plate 41 is close to the upper surface Sa of the substrate S.

[0025] In this embodiment, to prevent the connecting members 43 from interfering with the substrate S while the top panel 40 is lowered together with the cover 11, the four connecting members 43 are attached near the peripheral corners of the lower top panel 41 and the upper top panel 42, as shown in FIGS. 3A and 3B. More specifically, the four connecting members 43 are provided in areas outside the overlapping area (the area surrounded by a dashed line in FIG. 3B) where the substrates S overlap in a plan view from above. Furthermore, one of the four connecting members 43 is a fixed connecting member 43a that connects the lower top panel 41 and the upper top panel 42 with a collar (not shown) disposed between them, while the remaining three are push-pull bolts 43b that adjust the distance between the lower top panel 41 and the upper top panel 42. This allows the operator to easily and accurately adjust the horizontal position of the lower top panel 41. This adjustment operation will be described with reference to FIG. 4.

[0026] FIG. 4 is a schematic diagram illustrating the procedure for adjusting the posture of the lower top plate. As shown in FIG. 4(a), if the lower top plate 41 in the top plate unit 40 is tilted relative to the upper top plate 42, the gap during the drying process, i.e., the vacuum drying gap, will vary across the surface of the substrate S, making it difficult to achieve a uniform vacuum drying process. Such tilting of the lower top plate 41 can occur during the initial assembly stage of the apparatus or due to aging. Therefore, in this embodiment, a leveling process is performed when the vacuum drying apparatus 1 is not in operation, such as during assembly, factory installation, or maintenance of the vacuum drying apparatus 1. More specifically, an operator can adjust the lower top plate 41 to a horizontal posture by operating three push-pull bolts 43b, as shown in FIG. 4(b). In the vacuum drying apparatus 1 having the lower top plate 41 adjusted in this manner, a heating vacuum drying process is performed in the following order.

[0027] Fig. 5 is a flowchart showing the flow of the heating and reduced pressure drying process performed by the reduced pressure drying apparatus shown in Fig. 1. Figs. 6A to 6D are diagrams each showing the operation of each part of the apparatus during the heating and reduced pressure drying process. This process is realized by the CPU 91 of the control unit 90 executing a prepared control program to cause each part of the apparatus to perform a predetermined operation. The cover part 11 is previously heated to a predetermined temperature by operating the heater H (step S11).

[0028] 6A, the cover unit 11 is raised integrally with the top plate lifting unit 50 and the top plate unit 40 by the chamber driving unit 93, forming a loading / unloading space for loading and unloading the substrate S. Subsequently, the unprocessed substrate S (i.e., carrying an undried coating film F) held by the hand HD of an external transfer robot is moved to a position above the support pins 23 through the loading / unloading space. Thereafter, as indicated by the arrow in FIG. 6A, the hand HD is lowered, and the substrate S is transferred to the support pins 23 (step S12). Note that loading and unloading of the substrate S is not limited to being performed by a transfer robot, and any method using an appropriate transfer mechanism capable of transferring the substrate S in a horizontal position may be used.

[0029] When the loading of the substrate S is completed as described above, the hand HD retreats from the loading / unloading space. Subsequently, the chamber driving unit 93 lowers the cover unit 11 together with the pressure pin group 60, the top plate lifting unit 50, and the top plate unit 40 (step S13). As a result, the cover unit 11 comes into close contact with the bottom plate unit 12 via the seal member 13, as shown in FIG. 6B, to form a closed processing space SP. At the same time, all the pressure pins 61 abut against and press against the upper surface peripheral region Sa1 of the substrate S, thereby correcting any warpage of the substrate S (step S14), and the atmosphere control unit 94 begins depressurizing the processing space SP (step S15).

[0030] In this embodiment, during the initial stages of the straightening and reduced-pressure drying of the substrate S (hereinafter referred to as the "initial drying period"), the atmosphere control unit 94 adjusts the exhaust volume to prevent a decrease in the drying quality of the coating film F due to rapid evaporation of the solvent component in the coating film F. That is, during the initial drying period, the drying speed of the coating film F is suppressed, and the exhaust speed (exhaust volume per unit time) is suppressed until the amount of solvent component in the coating film F falls below a predetermined value, reaching a state known as semi-dry or semi-dry. In this specification, exhausting in this state with the exhaust volume suppressed by the exhaust unit 30 is referred to as "slow exhaust," and the exhaust volume during slow exhaust corresponds to an example of the "first exhaust volume" of the present invention. On the other hand, as will be described later, exhausting at a higher exhaust speed than slow exhaust in order to increase the reduced-pressure drying speed is referred to as "main exhaust," and the exhaust volume during main exhaust corresponds to an example of the "second exhaust volume" of the present invention.

[0031] During the slow exhaust, the top plate portion 40 (= lower top plate 41 + upper top plate 42 + connecting member 43) is positioned so that the opposing surface 41a is located directly above the coating film F. The position of the top plate portion 40 in the vertical direction Z at this time is referred to as the "lower position Pdw." If the top plate portion 40 is located higher than the lower position Pdw when the chamber 10 is closed, the top plate lifting unit 50 may lower the top plate portion 40 to the lower position Pdw before the start of slow exhaust (step S15). If it is desired to set the position of the top plate portion 40 during slow exhaust higher than the lower position Pdw, the top plate lifting unit 50 may adjust the position of the top plate portion 40 before the start of slow exhaust (step S15).

[0032] Once the initial drying period has elapsed ("YES" in step S16), the top-plate position control unit 95 raises only the top-plate unit 40 (= lower top plate 41 + upper top plate 42 + connecting member 43) to the upper position Pup (step S17), as shown in FIG. 6C. This process corresponds to 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, the above correction process makes the gap between the upper surface Sa and the opposing surface 41a of the lower top plate 41, i.e., the reduced-pressure drying gap GP, uniform within the plane of the upper surface Sa. Then, in this state, the atmosphere control unit 94 switches from slow exhaust to main exhaust, and the remaining solvent component of the coating film F rapidly evaporates (step S18). This makes it possible to adjust the solvent evaporation rate to a relatively high value while maintaining 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.

[0033] As described above, while the lower top plate 41 is positioned at the desired upper position Pup, reduced pressure drying processing is performed by main exhaust until the solvent concentration in the coating film F reaches a predetermined value or less (hereinafter referred to as the "main drying period"), and when this period has elapsed ("YES" in step S19), the exhaust unit 30 stops exhausting. Subsequently, purge gas is introduced (step S20), and the reduced pressure state in the processing space SP is released. Then, the cover unit 11 moves upward to a position (the position shown in FIG. 6A) where the substrate S can be loaded and unloaded. (Step S21) The substrate S in the processing space SP is released. Subsequently, an external transport robot is received and the substrate S after the drying process is carried out to the outside (step S22 ).

[0034] If there is a next substrate S to be processed (step S23 If the answer is "YES" in step S12, the process returns to step S12, where a new substrate S is received and the same process as above is carried out. S23 If the answer is "NO", the process can be terminated by performing a predetermined termination operation.

[0035] As described above, according to the first embodiment, a plurality of pressure pins 61 are suspended from the ceiling surface 11b of the cover portion 11 toward the upper peripheral region Sa1 of the substrate S. When the lower surface 11a of the cover portion 11 and the upper surface 12a of the bottom plate portion 12 are brought into close contact with each other to form the processing space SP, the pressure pins 61 come into contact with the upper peripheral region Sa1 of the substrate S to correct warpage of the substrate S. Furthermore, the top plate portion 40 is provided with through-holes 41b, 42b and punched-out portions 42a, through which the pressure pins 61 are inserted in the vertical direction Z. Therefore, by performing the top plate raising process and adjusting the exhaust rate while maintaining the correction of warpage of the substrate S by the pressure pins 61, the initial reduced-pressure drying process (steps S15 and S16) and the main reduced-pressure drying process (steps S18 and S19) can be performed in this order. Furthermore, the distance between the corrected upper surface Sa of the substrate S and the opposing surface 41a, i.e., the reduced-pressure drying gap GP, can be made uniform within the substrate surface. As a result, the drying process involving reduced pressure and heating can be successfully performed even on a warped substrate S.

[0036] Furthermore, since the initial reduced pressure drying process is performed prior to the main reduced pressure drying process, it is possible to effectively prevent problems such as the loss of uniformity of the coating film F due to the rapid evaporation of the solvent from the coating film F, and the coating film F can be dried under reduced pressure with excellent quality.

[0037] In addition, in this embodiment, the top plate portion 40 is switched between two positions Pdw and Pup in the vertical direction Z, but it may be switched between three or more positions or continuously while the pressing pins 61 are pressing the upper surface peripheral region Sa1 of the substrate S. In other words, according to this embodiment, it is possible to adjust the reduced-pressure drying gap GP over a wide range depending on the type and recipe of the coating film F while continuing the warpage correction process, and it has high versatility.

[0038] In this embodiment, the four connecting members 43 include one fixed connecting member 43a and three push-pull bolts 43b, which are provided at different positions on 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 section (a) of Figure 4, the lower top plate 41 can be adjusted to a horizontal position by adjusting the three push-pull bolts 43b, as shown in section (b) of the same figure. Therefore, the warp can be corrected well, and the gap GP during reduced-pressure drying can be made uniform within the substrate surface.

[0039] 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, but the gap may be adjusted using connecting members other than the push-pull bolts 43b. The number of connecting members is not limited to "3".

[0040] Furthermore, when the top panel 40 is viewed from above, the connecting member 43 is located outside the substrate S supported by the substrate support portion 20. This effectively prevents the connecting member 43 from interfering with the substrate S while the top panel 40 is moving up and down.

[0041] Furthermore, each presser pin 61 is detachable from the ceiling surface 11b of the cover portion 11. Therefore, multiple types of presser pins 61 with different downward protrusion amounts from the lower top plate 41 may be prepared in advance, and the type of presser pin 61 attached to the lower top plate 41 may be changed depending on the thickness of the substrate S. This makes it possible to accommodate the thickness of the substrate S, thereby increasing the versatility of the reduced-pressure drying apparatus 1.

[0042] As described above, in the first embodiment, the upper surface Sa of the substrate S corresponds to the "one principal surface" 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. The bottom plate portion 12 corresponds to an example of the "base portion" of the present invention. The initial drying period and the main drying period correspond to an example of the "first predetermined time" and "second predetermined time" of the present invention, respectively.

[0043] 7A and 7B are a perspective view and a plan view, respectively, of a second embodiment of a reduced-pressure drying apparatus according to the present invention, as viewed from below. This second embodiment differs from the first embodiment in that two alignment pin pairs, each consisting of two alignment pins 45, are added; otherwise, the configuration is the same as that of the first embodiment. One alignment pin pair is provided at one corner of the overlapping region (the region surrounded by a dashed line in FIG. 7B) where the substrates S overlap in a plan view from below, and the other alignment pin pair is provided at a corner diagonally opposite the above-mentioned corner.

[0044] Furthermore, when the chamber drive unit 93 lowers the cover unit 11, the amount by which the alignment pins 45 protrude downward from the opposing surface 41a is compared with the amount by which the pressure pins 61 protrude from the through-holes 41b. The amount by which each alignment pin 45 protrudes downward is greater than that of the pressure pin 61, and the tips of the alignment pins 45 are tapered downward. Therefore, when the cover unit 11 and the top plate unit 40 are lowered together in step S13, the alignment pins 45 and the pressure pins 61 descend together while maintaining the above-described relationship. Then, before the pressure pins 61 contact the substrate S, the tips of the alignment pins 45 contact the corners of the substrate S, and the substrate S is positioned in the substrate orientation defined by the two alignment pin pairs. The substrate S is then pressed down by the pressure pins 61, and warpage is corrected. Therefore, the reduced-pressure drying process can be performed with the substrate S always in a predetermined position and with its warpage corrected, and the reduced-pressure drying process can be performed more stably and with high quality. In this second embodiment, two pairs of alignment pins are used, but three or more pairs of alignment pins may be used. Also, although the alignment pins 45 are arranged corresponding to the corner portions of the substrate S, alignment pins that engage with other portions to position the substrate S may be used.

[0045] Furthermore, the installation position of the alignment pin 45 is not limited to the lower top plate 41, and it may be installed on the ceiling surface 11b of the cover part 11, similar to the presser pin 61. In this case, the alignment pin 45 is set to protrude downward from the ceiling surface 11b longer than the presser pin 61. For example, it needs to be set longer than the thickness of the substrate S. In this case, in addition to the through hole for the presser pin 61, it is also necessary to provide a through hole in the top plate part 40 for inserting the alignment pin 45.

[0046] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. 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 Fig. 8, the top plate portion 40 may be composed of only the lower top plate 41 (third embodiment). In other words, the lower surface of the lower top plate 41 may function as the "opposing surface" of the present invention, and the upper surface of the lower top plate 41 may be connected to the lift shaft 51.

[0047] In addition, in the above embodiment, 16 support pins 23 are used to support the underside of the substrate S, and 40 pressure pins 61 are used to press the upper peripheral area Sa1 of the substrate S, but the number and arrangement of the support pins 23 and pressure pins 61 can be modified as appropriate and applied.

[0048] Furthermore, in the above embodiment, the processing space SP is switched between open and closed by raising and lowering the cover portion 11, but the above switching may be performed by raising and lowering the bottom plate portion 12 or by raising and lowering both. [Industrial Applicability]

[0049] The present invention relates to a reduced pressure drying apparatus for drying a coating film formed on a substrate. [Explanation of symbols]

[0050] 1...Decompression drying device 10...Chamber 11...Cover part 12...Bottom plate (base) 20...Substrate support part 23...Support pin 30...Exhaust section 40...Top plate 41...Lower top plate 41a...(lower top plate) opposing surface 41b, 42b...Through hole 42...Upper top plate 42a...punching part (Through hole) 43...Connecting member 43a...Fixed connecting member 43b...Push-pull bolt 45...Alignment pin 50...Tabletop lifting section 60...Presser pin group 61...Presser pin 90...Control unit F...coating film GP: Gap during reduced pressure drying SP: Processing space Pdw…Downward position Pup…Upper position S...Substrate Sa...(substrate) top surface Sa1: Upper surface peripheral region Sa2…Top center area

Claims

1. A reduced pressure drying apparatus for drying a coating film formed in a central region of one main surface of a substrate, comprising: a chamber having a base portion and a cover portion provided above the base portion so as to be able to move up and down, wherein a processing space capable of accommodating the substrate is formed by bringing a lower surface of the cover portion into close contact with an upper surface of the base portion; a substrate support part that supports the substrate in the processing space with the coating film facing upward; a plurality of presser pins suspended from a ceiling surface of the cover portion toward the board supported by the board support portion; an exhaust unit that exhausts the processing space; a top plate portion having an opposing surface facing an upper surface of the substrate supported by the substrate support portion and a through hole provided for inserting the presser pin; a top plate lifting unit that lifts and lowers the top plate unit within the processing space between a lower position where the facing surface approaches an upper surface of the substrate supported by the substrate support unit and an upper position that is higher than the lower position; a chamber driving unit that raises and lowers the cover unit relative to the base unit while the plurality of pressure pins are suspended, a chamber driving unit that drives the cover unit to bring the lower surface of the cover unit into close contact with the upper surface of the base unit, the plurality of pressure pins contacting the peripheral region of the one main surface;

2. The reduced pressure drying apparatus according to claim 1, The top plate portion is an upper tabletop connected to the tabletop lifting unit; a lower top plate having the opposing surface and disposed below the upper top plate; a plurality of connecting members that connect the upper and lower top plates at different positions within the plane of the lower top plate; At least some of the plurality of connecting members are capable of adjusting the distance between the upper top plate and the lower top plate.

3. The reduced pressure drying apparatus according to claim 2, When the top plate portion is viewed from above, the plurality of connecting members are positioned outside the substrates supported by the substrate support portion.

4. The reduced pressure drying apparatus according to claim 1, The top plate portion is composed of only a lower top plate, A reduced pressure drying apparatus, wherein the lower surface of the lower top plate functions as the opposing surface, and the upper surface of the lower top plate is connected to the top plate lifting section.

5. The reduced pressure drying apparatus according to any one of claims 2 to 4, The pressure-reducing drying apparatus, wherein the plurality of pressure pins are detachable from the cover portion.

6. The reduced pressure drying apparatus according to any one of claims 2 to 4, a plurality of alignment pins suspended from the ceiling surface toward an end surface of the substrate supported by the substrate support portion via through holes different from the through holes provided in the top plate portion, The alignment pin protrudes downward from the ceiling surface longer than the pressing pin, A reduced-pressure drying apparatus in which, when the cover part is lowered by the chamber drive part, the tip of the alignment pin engages with the edge surface of the substrate before the pressure pin, thereby adjusting the position of the substrate in a horizontal plane.

7. The reduced pressure drying apparatus according to any one of claims 2 to 4, a plurality of alignment pins suspended from the opposing surface toward an edge surface of the substrate supported by the substrate support portion; The alignment pin protrudes downward from the opposing surface longer than the pressing pin, a pressure-reducing drying apparatus in which, when the cover portion and the top plate portion are lowered integrally by the chamber driving portion, the tip of the alignment pin engages with the edge surface of the substrate before the pressure pin abuts against the peripheral region of one of the main surfaces, thereby adjusting the position of the substrate in a horizontal plane.

8. The reduced pressure drying apparatus according to any one of claims 2 to 4, a control unit that controls the chamber drive unit, the top plate lifting unit, and the exhaust unit, The control unit an initial reduced pressure drying process in which, after controlling the chamber drive unit so that the lower surface of the cover unit is in close contact with the upper surface of the base unit and the peripheral region of the one main surface is in contact with the plurality of presser pins, the exhaust unit is controlled so that the amount of exhaust per unit time from the processing space becomes a first exhaust amount, while continuing reduced pressure drying of the coating film for a first predetermined time; a top plate raising process for controlling the top plate elevating unit so that the top plate unit is raised to the upper position after the initial reduced pressure drying process; and a main reduced pressure drying process for continuing reduced pressure drying of the coating film for a second predetermined time while controlling the exhaust unit so that the exhaust amount per unit time from the processing space becomes a second exhaust amount that is greater than the first exhaust amount. Run the vacuum drying device.

9. The reduced pressure drying apparatus according to claim 8, The control unit executes the main reduced-pressure drying process after the top plate raising process.

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