Decompression dryer

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 vacuum drying apparatus for drying a coating film formed on a substrate.

Background Art

[0002] As one of the manufacturing processes of semiconductor devices, there is a process of forming a functional film such as a resist film or a protective film on the substrate surface by applying a coating liquid on the substrate surface to form a coating film and drying it. In recent years, in the field of semiconductor devices, the demand for smaller and thinner devices has been increasing significantly. To meet such demands, panel-level fan-out packaging technology (FOPLP) for manufacturing semiconductor packages using substrates has attracted attention. Even when manufacturing a semiconductor package using FOPLP technology, the coating film formed on the substrate surface is dried before the substrate is subjected to an exposure and development process. As an apparatus for performing such a drying process, for example, as described in Patent Document 1, a vacuum drying apparatus that reduces the pressure in the surrounding space of the substrate on which the coating film is formed to volatilize the solvent component is used as an example of a substrate processing apparatus. In this apparatus, the substrate is placed on the upper surface of a substrate mounting stage, and a rectifying plate is arranged at an upper position of the substrate. By controlling the distance from the lower surface of this rectifying plate (corresponding to the "opposing surface of the top plate portion" of the present invention) to the upper surface of the substrate (substrate surface) (hereinafter referred to as the "gap during vacuum drying"), the evaporation rate of the solvent component from the coating film formed on the substrate is uniformly adjusted within the substrate surface.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, due to the influence of the material of the substrate for the semiconductor package and the like, the warpage tends to increase. Therefore, when the substrate is placed on the substrate mounting stage, the peripheral portion of the substrate may be in a posture where it is located above the central portion. Also, in other substrates, such warpage has come to be regarded as a problem. Due to the warpage of these substrates, the gap becomes non-uniform within the substrate plane during vacuum drying. As a result, uneven drying of the coating film occurs.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a vacuum drying apparatus capable of equalizing the gap within the substrate plane during vacuum drying and suppressing the occurrence of uneven drying of the coating film.

Means for Solving the Problems

[0006] One aspect of the present invention is a vacuum drying apparatus for drying a coating film formed in a central region of one main surface of a substrate, comprising a base portion, and a cover portion provided above the base portion so as to be capable of ascending and descending. By the lower surface of the cover portion being in close contact with the upper surface of the base portion, a chamber in which the substrate can be accommodated is formed. A substrate support portion for supporting the substrate in a posture with the coating film facing upward within the processing space, a plurality of pressing pins suspended from the ceiling surface of the cover portion toward the substrate supported by the substrate support portion, an exhaust portion for exhausting the processing space, a facing surface facing the upper surface of the substrate supported by the substrate support portion, and a top plate portion having a through hole provided for inserting the pressing pins. A top plate elevating portion for elevating the top plate portion between a lower position where the facing surface approaches the upper surface of the substrate supported by the substrate support portion within the processing space and an upper position above the lower position, and a chamber driving portion for relatively ascending and descending the cover portion with respect to the base portion while the plurality of pressing pins are suspended. When the lower surface of the cover portion is in close contact with the upper surface of the base portion by the chamber driving portion, the plurality of pressing pins are in contact with the peripheral region of one main surface.

[0007] In the present invention, the top plate portion has a facing surface facing 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, that is, the gap during reduced-pressure drying, the evaporation rate of the solvent from the coating film formed on the substrate can be controlled. Here, when the peripheral portion of the substrate is warped upward, the gap during reduced-pressure drying within the substrate surface becomes non-uniform. Thus, in the present invention, a plurality of pressing pins are suspended from the ceiling surface of the cover portion toward the substrate through the through holes of the top plate portion. Then, when the cover portion descends, the lower surface of the cover portion comes into close contact with the upper surface of the base portion to form a processing space, and the pressing pins come into contact with the peripheral region of one main surface of the substrate to correct the warp of the substrate.

Advantages of the Invention

[0008] As described above, in the present invention, when the lower surface of the cover portion and the upper surface of the base portion are in close contact with each other to form a processing space, the configuration is such that the warp of the substrate is corrected by a plurality of pressing pins suspended from the ceiling surface of the cover portion. Therefore, the distance (gap during reduced-pressure drying) between the corrected upper surface of the substrate and the facing surface can be made uniform within the substrate surface.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 6C

Figure 6D

Figure 7A

Figure 7B

Figure 8

Embodiments for Carrying Out the Invention

[0010] FIG. 1 is a diagram showing a first embodiment of a vacuum drying apparatus according to the present invention. More specifically, FIG. 1 is a combined diagram of a cross-sectional view showing the configuration of the main part of the vacuum drying apparatus 1 which is the first embodiment of the present invention, and a block diagram of the control system therefor. In each of the following figures, in order to clarify the arrangement relationship of each part of the apparatus, a right-handed XYZ orthogonal 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 vertically downward direction.

[0011] This vacuum drying apparatus 1 is applicable, for example, to a part of the manufacturing process of a panel level package (PLP), and a rectangular substrate S having a coating film F formed by a treatment liquid on its surface is the object to be treated. Specifically, the vacuum drying apparatus 1 receives the substrate S in a state where the coating film F is not dried, heats the substrate S, and reduces the pressure of the surrounding space, thereby volatilizing the solvent component in the coating film to dry and cure the coating film. Hereinafter, such substrate treatment is referred to as "heating vacuum drying treatment".

[0012] As the substrate S, for example, a glass substrate for a semiconductor package having a rectangular shape in plan view and having semiconductor chips, wirings, etc. laminated on its surface can be applied. Further, as the coating film F, for example, a photoresist film exists. Note that the material of the substrate and the type of the coating film are not limited thereto, and for example, a substrate used in the manufacture of semiconductor devices other than semiconductor packages and display devices may be a processing target.

[0013] The reduced-pressure drying apparatus 1 mainly includes a chamber 10, a substrate support portion 20, an exhaust portion 30, a top plate portion 40, a top plate lifting portion 50, a presser pin group 60, and a control portion 90. The chamber 10 receives the substrate S having the coating film F formed on the upper surface Sa therein and performs a predetermined process. The exhaust portion 30 is connected to the processing space of the chamber 10 (reference sign SP in FIGS. 6B to 6D described later) and exhausts the processing space. The control portion 90 includes a CPU (Central Processing Unit) 91, and the CPU 91 executes a predetermined control program to control the operations of the respective portions 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 portion 90 to the respective portions of the apparatus.

[0014] FIG. 2 is a perspective view showing the arrangement relationship between the chamber and the substrate support portion in the vacuum drying apparatus shown in FIG. 1. The chamber 10 forms a processing space (reference numeral SP in FIGS. 6B to 6D) for evacuating the periphery of the substrate S, prevents the solvent components volatilized by the processing from scattering to the surroundings, and has a 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 the cover portion 11 and the bottom plate portion 12 are combined via a sealing member 13. More specifically, the lower surface 11a of the cover portion 11 having a cavity with an open bottom is in close contact with the upper surface 12a of the substantially flat bottom plate portion 12 via the sealing member 13, thereby closing the upper portion of the bottom plate portion 12. As a result, a processing space is formed between the cover portion 11 and the bottom plate portion 12. The cover portion 11 and the bottom plate portion 12 are formed of a metal material such as stainless steel or aluminum, for example. The sealing member 13 is formed of an elastic material such as rubber. Further, the ceiling surface 11a of the cover portion 11 is provided so as to cover the substrate S supported by the substrate support portion 20 from above via the top plate portion 40 as will be described later. Moreover, the region of the ceiling surface 11b facing the upper surface peripheral region Sa1 of the substrate S is finished so that the pressing pin 61 can be detachably attached.

[0015] The cover portion 11 is supported by a support mechanism (not shown) so as to be movable up and down in the vertical direction (Z direction), and the chamber driving portion 93 provided in the control portion 90 appropriately moves the cover portion 11 up and down in the Z direction. Thereby, the chamber 10 is opened and closed. Specifically, the chamber driving portion 93 positions the cover portion 11 so that the lower surface 11a of the cover portion 11 is in close contact with the upper surface 12a of the bottom plate portion 12 (see FIGS. 6B to 6D), whereby the chamber 10 is closed and a processing space is formed inside. On the other hand, when the cover portion 11 is moved upward by the chamber driving portion 93, as shown in FIGS. 1 and 2, the cover portion 11 and the bottom plate portion 12 are separated and the processing space is opened. Processing on the substrate S is executed in the closed state of the cover portion 11 (FIGS. 6B to 6D), while it is possible to take in and out the substrate S and perform maintenance work on internal components in the open state (FIGS. 1, 2, 6A).

[0016] Further, a planar heater H is attached to the outer surface of the cover portion 11. Each heater H is electrically connected to the heater driving unit 92 of the control unit 90. Therefore, by operating the heater H by the heater driving unit 92, it is possible to heat the substrate S with the cover portion 11 in the closed state. In this embodiment, a so-called panel heater is used as the heater H, but a strip-shaped or linear heater may also be used. Also, the mounting position of the heater H is not limited to the outer surface of the cover portion 11, and it may be attached to the inner surface or built into the cover portion 11.

[0017] As shown in FIGS. 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 a plurality (four in this embodiment) of base support members 21 standing upright from the upper surface of the bottom plate portion 12 so as to surround the exhaust through hole 12a provided in the central portion of the bottom plate portion 12. The base member 22 is supported by these base support members 21. Further, the base member 22 has a planar size wider than that of the substrate S, and a plurality of support pins 23 stand upright from the upper surface thereof. 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 the substrate S can be horizontally supported from below with the coating film F facing upward.

[0018] An exhaust pipe 31 of the exhaust portion 30 is connected to the exhaust through hole 12a. Further, a purge through hole 12b is provided in the bottom plate portion 12 in addition to the exhaust through hole 12a. And a purge pipe 32 of the exhaust portion 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. Also, 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 the atmosphere control unit 94 of the control unit 90. Specifically, the exhaust valve 33 and the pump 34 operate according to the control signal from the atmosphere control unit 94, so that the gas in the chamber 10 is exhausted and the processing space is depressurized. Further, the purge valve 35 operates according to the control signal from the atmosphere control unit 94, so that the purge gas is introduced into the processing space from an external gas source. In this way, the exhaust unit 30 operates according to the control signal from the atmosphere control unit 94, so that the atmosphere in the processing space is controlled. Then, under the controlled atmosphere, the vacuum drying process is executed. Further, when performing the vacuum drying process in this way, in order to adjust the evaporation rate of the solvent from the coating film F formed on the substrate S, in this embodiment, the top plate portion 40 is provided.

[0020] FIG. 3A is a perspective view of the top plate portion, the pressing pins, and the substrate as viewed obliquely from above. FIG. 3B is a perspective view of the top plate portion and the pressing pins as viewed obliquely from below. As shown in FIGS. 1 and 3A, the top plate portion 40 is arranged so as to cover the substrate S having the coating film F formed in the central upper surface region Sa2 except for the upper surface peripheral region Sa1 from above. The top plate portion 40 has a lower top plate 41 that functions as a facing surface 41a whose lower surface faces substantially parallel to the upper surface Sa of the substrate S, and an upper top plate 42 arranged directly above the lower top plate 41. The facing 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 elevating portion 50, it covers the entire substrate as viewed from above. In the lower top plate 41, through holes 41b are provided on the lifting and lowering paths of a plurality of pressing pins 61 suspended from the ceiling surface 11b, and the pressing pins 61 are inserted through the through holes 41b so as to be movable up and down in the vertical direction Z. In this embodiment, in order to press the upper surface peripheral region Sa1 of the substrate S, ten pressing pins 61 are detachably attached to the ceiling surface 11b of the cover portion 11 so as to face the upper surface peripheral region Sa1 of the substrate S. Therefore, a total of 40 pressing pins 61 are suspended toward the upper surface peripheral region Sa1 of the substrate S.

[0021] An 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. In order to reduce the weight of the upper top plate 42 and to move up and down a part of the pressing pins 61 (hereinafter referred to as “punching-through pins 61”), punching parts 42a are provided in a region of the upper top plate 42 other than the central part and the peripheral part. Further, through holes 42b are provided in the peripheral part on the lifting and lowering paths of the pressing pins 61 other than the punching-through pins. Therefore, the punching-through pins 61 constituting the pressing pin group 60 can move up and down through the through holes 41b and the punching parts 42a, and the remaining pressing pins 61 can move up and down through the through holes 41b and 42b. Thus, in the present embodiment, the punching part 42a functions as an example of the “through hole” of the present invention. If the punching part 42a is not provided, through holes 42b may be provided in the upper top plate 42 in the same number and the same arrangement as the through holes 42b provided in the lower top plate 41.

[0022] At the center of the upper surface of the upper top plate 42, the lifting shaft 51 of the top plate lifting unit 50 is connected. Further, the upper top plate 42 and the lower top plate 41 are interconnected and integrated by four connecting members 43 while being separated from each other by a minute distance in the vertical direction Z. Moreover, the lifting shaft 51 is attached to the cover portion 11 so as to be movable up and down in the vertical direction Z, and a lifting mechanism 52 for moving the lifting shaft 51 up and down is fixedly attached to the cover portion 11. Therefore, when the cover portion 11 is moved up and down by the chamber driving portion 93 of the control portion 90, the top plate lifting unit 50 and the top plate portion 40 are integrally moved up and down accordingly. For example, when the cover portion 11 moves upward, as shown in FIG. 1, the top plate portion 40 is positioned at a position separated upward from the substrate support portion 20 and the substrate S supported by the substrate support portion 20. Conversely, when the cover portion 11 moves downward, the top plate portion 40 approaches the substrate S, and the pressing pins 61 abut against and press the peripheral edge region Sa1 of the upper surface of the substrate S, thereby correcting the warp of the substrate S. In order to perform such a correction process, as shown in the enlarged view in FIG. 3B, the tip of the pressing pin 61 always protrudes downward from the through hole 41b of the lower top plate 41. That is, 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 pressing pins 61 continue to abut against the peripheral edge region Sa1 of the upper surface of the substrate S to keep the substrate S in a horizontal posture.

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

[0024] The upper top plate 42, the lower top plate 41, the connecting members 43, and the top plate lifting unit 50 configured as described above move up and down in the vertical direction Z integrally with the cover portion 11. For this reason, as shown in FIG. 6B to be described later, when the cover portion 11 descends with the tip of the pressing pin 61 protruding downward from the lower top plate 41 and the chamber 10 is closed, all the pressing pins 61 abut against the peripheral portion of the substrate S and press downward to correct the warp. Further, the opposing surface 41a of the lower top plate 41 is close to the upper surface Sa of the substrate S.

[0025] Also, in the present embodiment, in order to prevent the connecting member 43 from interfering with the substrate S while the top plate portion 40 is descending together with the cover portion 11, the four connecting members 43 are attached near the peripheral corner portions of the lower top plate 41 and the upper top plate 42 as shown in FIGS. 3A and 3B. More specifically, the four connecting members 43 are respectively provided in an outer region outside the overlapping region (the region surrounded by the one-dot chain line in FIG. 3B) that overlaps the substrate S in a plan view from above. Moreover, one of the four is a fixed connecting member 43a that connects the lower top plate 41 and the upper top plate 42 with a collar (not shown) disposed therebetween, while the remaining three are push-pull bolts 43b for adjusting the distance between the lower top plate 41 and the upper top plate 42 with respect to the upper top plate 42. For this reason, the horizontal posture of the lower top plate 41 can be easily and highly accurately adjusted by the operator. This adjustment operation will be described with reference to FIG. 4.

[0026] FIG. 4 is a schematic diagram for explaining the posture adjustment procedure of the lower top plate. As shown in the (a) column of FIG. 4, when the lower top plate 41 is inclined with respect to the upper top plate 42 in the top plate portion 40, the gaps during the drying process, that is, the gaps during vacuum drying, differ within the plane of the substrate S, making it difficult to perform a uniform vacuum drying process. Such an inclination of the lower top plate 41 may occur at the initial stage of assembling the apparatus or due to aging changes. Therefore, in the present embodiment, the horizontal adjustment process is executed at a timing when the vacuum drying apparatus 1 is not operating, such as during the assembly stage of the vacuum drying apparatus 1, the factory installation stage of the vacuum drying apparatus 1, and the maintenance stage of the vacuum drying apparatus 1. More specifically, by the operator operating the three push-pull bolts 43b, as shown in the (b) column of the same figure, the lower top plate 41 can be adjusted to a horizontal posture. In the vacuum drying apparatus 1 having the lower top plate 41 adjusted in this way, the heat-vacuum drying process is executed in the order described below.

[0027] FIG. 5 is a flowchart showing the flow of the heat-vacuum drying process by the vacuum drying apparatus shown in FIG. 1. FIGS. 6A to 6D are diagrams schematically showing the operations of the respective parts of the apparatus in the heat-vacuum drying process. This process is realized by the CPU 91 of the control unit 90 executing a control program prepared in advance to cause the respective parts of the apparatus to perform predetermined operations. In advance, the cover part 11 is heated to a predetermined temperature by the operation of the heater H (step S11).

[0028] Also, as shown in FIG. 6A, the cover part 11 is lifted integrally with the top plate lifting part 50 and the top plate part 40 by the chamber driving part 93, and a loading / unloading space for loading and unloading the substrate S is formed. Subsequently, the untreated substrate S (i.e., the substrate S carrying the 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. After that, as shown by the arrow in FIG. 6A, the hand HD descends, and the substrate S is transferred to the support pins 23 (step S12). Note that the loading and unloading of the substrate S are not limited to those by a transfer robot, and any method using an appropriate transfer mechanism capable of transferring in a horizontal posture may be used.

[0029] When the loading of the substrate S is completed as described above, the hand HD retracts from the loading / unloading space. Subsequently, the cover part 11 is lowered integrally with the pressing pin group 60, the top plate lifting part 50, and the top plate part 40 by the chamber driving part 93 (step S13). As a result, the cover part 11 comes into close contact with the bottom plate part 12 through the seal member 13 as shown in FIG. 6B, and a closed processing space SP is formed. At the same time, all the pressing pins 61 abut on and press the peripheral edge region Sa1 of the upper surface of the substrate S, thereby correcting the warp of the substrate S (step S14), and the decompression of the processing space SP by the atmosphere control part 94 is started (step S15).

[0030] In this embodiment, in order to prevent the drying quality of the coating film F from deteriorating due to the rapid volatilization of the solvent component in the coating film F during the correction of the substrate S and the initial stage of reduced-pressure drying (hereinafter, these are referred to as the "initial drying period"), the atmosphere control unit 94 adjusts the exhaust volume. 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 the solvent component in the coating film F falls below a predetermined value and reaches a state called so-called semi-dry or raw-dry. In this specification, the exhaust in the state where the exhaust volume by the exhaust unit 30 is suppressed in this way is referred to as "slow exhaust", and the exhaust volume in the 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 an exhaust speed larger than that of the slow exhaust in order to increase the reduced-pressure drying speed is referred to as "main exhaust", and the exhaust volume in the main exhaust corresponds to an example of the "second exhaust volume" of the present invention.

[0031] Also, while the slow exhaust is being performed, 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". When the top plate portion 40 is located at a position higher than the lower position Pdw when the chamber 10 is closed, the top plate elevating unit 50 may lower the top plate portion 40 to position it at the lower position Pdw before the start of the slow exhaust (step S15). Further, when it is desired to set the position of the top plate portion 40 during the slow exhaust higher than the lower position Pdw, the position of the top plate portion 40 may be adjusted by the top plate elevating unit 50 before the start of the slow exhaust (step S15).

[0032] When the initial drying period elapses (i.e., “YES” in step S16), as shown in FIG. 6C, only the top plate portion 40 (= lower top plate 41 + upper top plate 42 + connecting member 43) is lifted up to the upper position Pup by the top plate position control unit 95 (step S17). This process corresponds to an example of the “top plate lifting process” of the present invention. As a result, the gap GP during reduced-pressure drying becomes a preset value. Also, by the above correction process, within the plane of the upper surface Sa, the distance between the opposing surface 41a of the lower top plate 41, that is, the gap GP during reduced-pressure drying, is uniform. And in this state, the atmosphere control unit 94 switches from slow exhaust to main exhaust, and the remaining solvent components of the coating film F rapidly evaporate (step S18). As a result, it is possible to adjust the evaporation rate of the solvent to a relatively high value while ensuring excellent in-plane uniformity. Consequently, the coating film F on the substrate S can be dried with excellent quality while shortening the reduced-pressure drying time.

[0033] When the period (hereinafter referred to as the “main drying period”) until the reduced-pressure drying process is performed by main exhaust while positioning the lower top plate 41 at the desired upper position Pup as described above and the solvent concentration in the coating film F reaches a predetermined value or less elapses (i.e., “YES” in step S19), the exhaust unit 30 stops exhausting. Subsequently, by introducing the purge gas (step S20), the reduced-pressure state of the processing space SP is released. Then, the cover portion 11 moves upward to a position where the substrate S can be loaded and unloaded (the position shown in FIG. 6A), and the substrate S in the processing space SP is opened. Subsequently, the dried substrate S is carried out to the outside by receiving an external transfer robot (step S21).

[0034] If there is a next substrate S to be processed (i.e., “YES” in step S22), the process returns to step S12 to receive a new substrate S and the same processing as above is performed. On the other hand, if there is no new substrate S (i.e., “NO” in step S22), the process can be terminated after a predetermined end operation.

[0035] As described above, according to the first embodiment, a plurality of pressing pins 61 are suspended from the ceiling surface 11b of the cover portion 11 toward the upper surface peripheral region Sa1 of the substrate S. Then, when the lower surface 11a of the cover portion 11 and the upper surface 12a of the bottom plate portion 12 are in close contact with each other to form the processing space SP, the pressing pins 61 come into contact with the upper surface peripheral region Sa1 of the substrate S to correct the warp of the substrate S. Further, through holes 41b, 42b and punching portions 42a are provided in the top plate portion 40, and the pressing pins 61 are inserted therethrough in the vertical direction Z. Therefore, by performing the top plate lifting process and the exhaust volume adjustment while maintaining the warp correction of the substrate S by the pressing pins 61, the initial vacuum drying process (steps S15, S16) and the main vacuum drying process (steps S18, S19) can be executed in this order. Moreover, the distance between the upper surface Sa of the corrected substrate S and the opposing surface 41a, that is, the gap GP during vacuum drying can be made uniform within the substrate surface. As a result, even for a substrate S with warpage, the drying process involving vacuum and heating can be performed well.

[0036] Further, since the initial vacuum drying process is executed prior to the main vacuum drying process, it is possible to effectively prevent problems such as the uniformity of the coating film F being impaired due to the rapid evaporation of the solvent from the coating film F, and the coating film F can be vacuum dried with excellent quality.

[0037] Also, in the present embodiment, the top plate portion 40 is switched at two positions Pdw and Pup in the vertical direction Z, but it may be switched in three or more steps or continuously while pressing the upper surface peripheral region Sa1 of the substrate S with the pressing pins 61. That is, according to the present embodiment, it is possible to widely adjust the gap GP during vacuum drying according to the type and recipe of the coating film F while continuing the warp correction process, and it has high versatility.

[0038] In addition, in the present embodiment, as the four connecting members 43, one fixed connecting member 43a and three push-pull bolts 43b are provided at different positions from each other within the plane of the lower top plate 41. Therefore, as shown in the (a) column of FIG. 4, even if the lower top plate 41 is in a tilted posture with respect to the horizontal plane, by adjusting with the three push-pull bolts 43b, as shown in the (b) column of the same figure, it is possible to adjust the lower top plate 41 to a horizontal posture. Therefore, the above-mentioned warpage correction can be performed well, and the gap GP during vacuum drying can be made uniform within the substrate plane.

[0039] In the present embodiment, three push-pull bolts 43b are used as the connecting members for adjusting the distance between the upper top plate 42 and the lower top plate 41, but it may be configured to be adjusted by a connecting member other than the push-pull bolts 43b. Also, the number of the connecting members is not limited to "3".

[0040] Also, when the top plate portion 40 is viewed from above, the connecting member 43 is located outside the substrate S supported by the substrate support portion 20. For this reason, it is possible to effectively prevent the connecting member 43 from interfering with the substrate S during the lifting and lowering movement of the top plate portion 40.

[0041] Also, each pressing pin 61 is detachable from the ceiling surface 11b of the cover portion 11. Therefore, a plurality of types of pressing pins 61 having different protruding amounts protruding downward from the lower top plate 41 may be prepared in advance, and the type of the pressing pin 61 attached to the lower top plate 41 may be changed according to the thickness of the substrate S. Thereby, it is possible to cope with the thickness of the substrate S and the like, and the versatility of the vacuum drying apparatus 1 can be enhanced.

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

[0043] FIGS. 7A and 7B are a perspective view and a plan view, respectively, of a second embodiment of a vacuum drying apparatus according to the present invention as viewed from below. The second embodiment differs significantly from the first embodiment in that two additional pairs of alignment pins 45 each consisting of two alignment pins are provided, and the other configurations are the same as those of the first embodiment. One pair of alignment pins is provided at one corner portion of an overlapping region (the region surrounded by the dashed-dotted line in FIG. 7B) where the substrate S overlaps in a plan view from below, and the other pair of alignment pins is provided at a corner portion in the diagonal direction with respect to the above corner portion.

[0044] Also, when the cover part 11 is lowered by the chamber drive part 93, comparing the protruding amount of the alignment pins 45 downward from the opposing surface 41a with the protruding amount of the pressing pins 61 from the through holes 41b, the protruding amount of each alignment pin 45 is larger than that of the pressing pin 61, and the tip of the alignment pin 45 is finished in a tapered shape downward. For this reason, when the cover part 11 and the top plate part 40 are integrally lowered in step S13, the alignment pins 45 and the pressing pins 61 descend together while maintaining the above relationship. Then, before the pressing pin 61 contacts the substrate S, the tip of the alignment pin 45 contacts the corner part of the substrate S, and the substrate S is positioned in the substrate posture defined by the two sets of alignment pin pairs. After that, the substrate S is pressed by the plurality of pressing pins 61, and the warp is corrected. Therefore, the vacuum drying process can be executed with the substrate S always at a predetermined position and in a state where the warp is corrected, and the vacuum drying process can be performed more stably and with higher quality. In this second embodiment, two sets of alignment pin pairs are used, but three or more sets of alignment pin pairs may be used. Also, although the alignment pins 45 are arranged corresponding to the corner parts of the substrate S, alignment pins that engage with other parts to position the substrate S may be used.

[0045] Also, the installation position of the alignment pins 45 is not limited to the lower top plate 41, and similar to the pressing pins 61, it may be installed on the ceiling surface 11b of the cover part 11. In this case, regarding the protruding amount downward from the ceiling surface 11b, the alignment pins 45 are set to be longer than the pressing pins 61. For example, it is necessary to set it to be longer than the thickness of the substrate S. Also, in this case, in addition to the through holes for the pressing pins 61, it is necessary to provide through holes for inserting the alignment pins 45 in the top plate part 40.

[0046] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made other than those described above without departing from the spirit thereof. For example, in the above embodiment, the top plate portion 40 is constituted by the lower top plate 41 and the upper top plate 42. However, as shown in FIG. 8, the top plate portion 40 may be constituted by only the lower top plate 41 (Third Embodiment). That is, 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 elevating shaft 51.

[0047] Further, in the above embodiment, the lower surface of the substrate S is supported by 16 support pins 23, and the peripheral edge region Sa1 of the upper surface of the substrate S is pressed by 40 pressing pins 61. However, the number and arrangement of the support pins 23 and the pressing pins 61 can be appropriately modified and applied.

[0048] Furthermore, in the above embodiment, the opening and closing of the processing space SP are switched by the elevation of the cover portion 11. However, the switching may be configured to be performed by the elevation of the bottom plate portion 12 or the elevation of both.

Industrial Applicability

[0049] This invention relates to a vacuum drying apparatus for drying a coating film formed on a substrate.

Explanation of Reference Numerals

[0050] 1... Vacuum drying apparatus 10... Chamber 11... Cover portion 12... Bottom plate portion (base portion) 20... Substrate support portion 23... Support pin 30... Exhaust portion 40... Top plate portion 41... Lower top plate 41a... Opposing surface (of the lower top plate) 41b, 42b... Through hole 42... Upper top plate 42a... Punched portion (through hole) 43... Connecting member 43a... Fixed connection member 43b... Push-pull bolt 45... Alignment pin 50... Top plate lifting part 60... Pressing pin group 61... Pressing pin 90... Control unit F... Coating film GP... Gap during vacuum drying SP... Processing space Pdw... Lower position Pup... Upper position S... Substrate Sa... (Upper surface of the) substrate Sa1... Upper surface peripheral region Sa2... Upper surface central region

Claims

1. A vacuum 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 movable up and down, wherein a processing space capable of accommodating the substrate is formed by bringing the lower surface of the cover portion into close contact with the upper surface of the base portion; a substrate support portion for supporting the substrate in a posture with the coating film facing upward within the processing space; a plurality of pressing pins suspended from the ceiling surface of the cover portion toward the substrate supported by the substrate support portion; an exhaust portion for exhausting the processing space; a top plate portion having a facing surface facing the upper surface of the substrate supported by the substrate support portion and a through hole provided for inserting the pressing pins; a top plate lifting portion for lifting and lowering the top plate portion between a lower position where the facing surface approaches the upper surface of the substrate supported by the substrate support portion and an upper position above the lower position within the processing space; a chamber driving portion for relatively moving the cover portion up and down with respect to the base portion while the plurality of pressing pins are suspended; A vacuum drying apparatus, characterized in that when the lower surface of the cover portion is in close contact with the upper surface of the base portion by the chamber driving portion, the plurality of pressing pins abut against the peripheral region of the one main surface.

2. The vacuum drying apparatus according to claim 1, wherein the top plate portion includes an upper top plate connected to the top plate lifting portion, a lower top plate having the facing surface and disposed below the upper top plate, and a plurality of connecting members connecting the upper top plate and the lower top plate at different positions within the plane of the lower top plate, and at least a part of the plurality of connecting members is capable of adjusting the distance between the upper top plate and the lower top plate.

3. The vacuum drying apparatus according to claim 2, wherein when the top plate portion is viewed from above, the plurality of connecting members are located outside the substrate supported by the substrate support portion.

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

5. The vacuum drying apparatus according to any one of claims 2 to 4, wherein the plurality of pressing pins are detachable from the cover portion.

6. A vacuum drying apparatus according to any one of claims 2 to 4, further comprising a plurality of alignment pins suspended from the ceiling surface toward an end surface of the substrate supported by the substrate support portion through a through hole different from the through hole provided in the top plate portion, wherein, with respect to the amount of protrusion downward from the ceiling surface, the alignment pins are longer than the pressing pins, a vacuum drying apparatus, wherein when the cover portion is lowered by the chamber driving portion, the tip of the alignment pin engages with the end surface of the substrate prior to the pressing pin, thereby adjusting the position of the substrate in a horizontal plane.

7. A vacuum drying apparatus according to any one of claims 2 to 4, further comprising a plurality of alignment pins suspended from the opposing surface toward an end surface of the substrate supported by the substrate support portion, wherein, with respect to the amount of protrusion downward from the opposing surface, the alignment pins are longer than the pressing pins, a vacuum drying apparatus, wherein when the cover portion and the top plate portion are integrally lowered by the chamber driving portion, the tip of the alignment pin engages with the end surface of the substrate prior to the contact of the pressing pin with the peripheral region of the one main surface, thereby adjusting the position of the substrate in a horizontal plane.

8. A vacuum drying apparatus according to any one of claims 2 to 4, further comprising a control unit that controls the chamber driving unit, the top plate elevating unit, and the exhaust unit, wherein the control unit after controlling the chamber driving unit so that the lower surface of the cover portion is in close contact with the upper surface of the base portion and the peripheral region of the one main surface is in contact with the plurality of pressing pins, an initial vacuum drying process of continuously performing vacuum drying on the coating film for a first predetermined time while controlling the exhaust unit so that the exhaust amount per unit time from the processing space becomes a first exhaust amount; after the initial vacuum drying process, a top plate rising process of controlling the top plate elevating unit so that the top plate portion rises to the upper position, and a main vacuum drying process of continuously performing vacuum drying on 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 greater than the first exhaust amount; A vacuum drying apparatus that executes the above processes.

9. A vacuum drying apparatus according to claim 8, wherein the control unit executes the main vacuum drying process after the top plate rising process.

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