The present application relates to a substrate processing apparatus and a substrate processing method for suppressing cracking and chipping of a laminated substrate manufactured by bonding substrates, and more particularly to a technique of applying a filler to a gap formed between edge portions of the substrates constituting the laminated substrate. The method includes: applying the filler to a gap between an edge portion of the first substrate and an edge portion of the second substrate; curing the applied filler; generating, by an infrared imaging device, an image of an edge portion of the laminated substrate to which the filler is applied; and determining a filling state of the filler applied to the gap between the edge portion of the first substrate and the edge portion of the second substrate based on the image.

TECHNICAL FIELD

The present invention relates to a substrate processing method and a substrate processing apparatus for suppressing cracking and chipping of a laminated substrate manufactured by bonding substrates, and more particularly to a technique of applying a filler to a gap formed between edge portions of the substrates constituting the laminated substrate.

BACKGROUND ART

In recent years, in order to achieve higher density and higher functionality in semiconductor devices, three-dimensional packaging technology, in which substrates are laminated and integrated three-dimensionally, has been developed. For example, in the three-dimensional packaging technology, a device surface of a first substrate on which integrated circuits and electrical wires are formed is bonded to a device surface of a second substrate on which integrated circuits and electrical wires are formed. After the first substrate is bonded to the second substrate, the second substrate is thinned by a polishing apparatus or a grinding apparatus. In this manner, integrated circuits can be stacked in a direction perpendicular to the device surfaces of the first substrate and the second substrate.

In the three-dimensional packaging technology, three or more substrates may be bonded to each other. For example, a third substrate may be bonded to the second substrate after the second substrate bonded to the first substrate has been thinned, and then the third substrate may be thinned. In this specification, a substrate in a form of substrates bonded to each other may be referred to as a “laminated substrate”. Generally, an edge portion of a substrate is polished in advance in a rounded shape or a beveled shape in order to prevent cracking or chipping of the edge portion. When the second substrate having such a shape is grinded, an acute edge is formed in the second substrate as a result of grinding. This acute edge (hereinafter referred to as a knife-edge portion) is constituted by a grinded back surface and a circumferential surface of the second substrate. Such a knife-edge portion is likely to be chipped by a physical contact, and the laminated substrate itself may be broken during transportation of the laminated substrate. Furthermore, insufficient bonding between the first substrate and the second substrate may cause the second substrate to be cracked during grinding.

Thus, a filler is applied to the edge portion of the laminated substrate before the second substrate is grinded in order to prevent the knife-edge portion from cracking or chipping. The filler is applied to a gap between an edge portion of the first substrate and an edge portion of the second substrate. The filler can support the knife-edge portion that has been formed after the second substrate is grinded, and can prevent cracking or chipping of the knife-edge portion.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

However, when the filler is applied to the gap between the edge portion of the first substrate and the edge portion of the second substrate, a preset applying condition may causes a filling failure, such as lacking of the filler or over-applying of the filler. If the laminated substrate is processed in a subsequent process with the filling failure, the laminated substrate may be damaged, and as a result, the laminated substrate or a process performance may be adversely affected. Conventionally, filling of the filler that has been applied to the laminated substrate is checked after the application of the filler has been completed, and there were some cases that the laminated substrate should be destroyed.

It is therefore an object of the present invention to provide a substrate processing method and a substrate processing apparatus capable of monitoring a filling state of a filler in a gap between an edge portion of a first substrate and an edge portion of a second substrate while applying the filler to the gap.

Solution to Problem

In an embodiment, there is provided a substrate processing method of applying a filler to a laminated substrate having a first substrate and a second substrate bonded to each other, comprising: applying the filler to a gap between an edge portion of the first substrate and an edge portion of the second substrate; curing the applied filler; generating, by an infrared imaging device, an image of an edge portion of the laminated substrate to which the filler is applied; and determining a filling state of the filler in the gap based on the image.

In an embodiment, determining the filling state comprises determining the filling state based on a size of the filler in a preset target region on the image.

In an embodiment, applying of the filler is terminated based on the filling state.

In an embodiment, the substrate processing method further comprises additionally applying the filler based on the filling state.

In an embodiment, the substrate processing method further comprises counting the number of voids generated in the filler on the image, and determining that an abnormally has occurred when the number of voids has reached an acceptable value.

In an embodiment, applying of the filler, curing of the filler, and generating of the image is performed while rotating the laminated substrate.

In an embodiment, an applying condition for the filler is changed based on the filling state.

In an embodiment, the image is generated at each of measurement points of the laminated substrate while the laminated substrate makes one revolution, and an applying condition for the filler in at least one of the measurement points is changed based on the filling state at each of the measurement points and location information on the measurement points.

In an embodiment, the substrate processing method further comprises changing an applying condition for the filler in a next laminated substrate based on the filling state.

In an embodiment, the applying condition includes at least one of a total amount of the filler to be applied, a shape of a filler emitting port of an application device configured to apply the filler, a distance between the laminated substrate and the filler emitting port, an amount of the filler to be emitted from the filler emitting port per unit time, and a rotation speed of the laminated substrate.

In an embodiment, the infrared imaging device is configured to emit infrared light approximately perpendicularly to a bonding surface of the first substrate and the second substrate of the laminated substrate.

In an embodiment, there is provided a substrate processing apparatus for applying a filler to a laminated substrate having a first substrate and a second substrate bonded to each other, comprising: a filler application module configured to apply the filler to the laminated substrate; and an operation controller configured to control an operation of the filler application module, wherein the filler application module includes: a substrate holder configured to hold the laminated substrate; an application device configured to apply the filler to a gap between an edge portion of the first substrate and an edge portion of the second substrate; a curing device configured to cure the applied filler; and an infrared imaging device configured to generate an image of an edge portion of the laminated substrate to which the filler is applied, and the operation controller is configured to determine a filling state of the filler applied to the gap based on the image.

In an embodiment, the operation controller is further configured to instruct the filler application module based on the filling state to cause the application device to terminate application of the filler.

In an embodiment, the operation controller is further configured to instruct the filler application module based on the filling state to additionally apply the filler.

In an embodiment, the filler application module further includes a rotating mechanism configured to rotate the substrate holder.

In an embodiment, the operation controller is configured to change an applying condition for the filler based on the filling state.

Advantageous Effects of Invention

According to the present invention, the filler is applied to the laminated substrate while the filling state of the filler is monitored. Therefore, the application of the filler can be terminated at an appropriate timing. Moreover, additional application of the filler or changing of the applying condition can be performed as needed. As a result, appropriate filling of the filler can be achieved.

DESCRIPTION OF EMBODIMENTS

FIGS.1A and1Bare enlarged cross-sectional views each showing an edge portion E of a substrate W. More specifically,FIG.1Ais a cross-sectional view of a substrate W of a so-called straight type, andFIG.1Bis a cross-sectional view of a substrate W of a so-called round type. The edge portion E is a portion constituting an outermost circumferential surface inclined with respect to a flat surface (a front surface and a back surface) of the substrate W and having a rounded shape or a beveled shape. In the substrate W inFIG.1A, the edge portion E is an outermost circumferential surface including an upper slope portion (or upper bevel portion) B1, a lower slope portion (or lower bevel portion) B2, and a side portion (or apex) B3 of the substrate W. In the substrate W inFIG.1B, the edge portion E is a portion constituting an outermost circumferential surface of the substrate W and having a curved cross section. The edge portion E may be also referred to as a bevel portion.

FIG.2is an enlarged cross-sectional view showing a laminated substrate Ws. The laminated substrate Ws has a structure in which a first substrate W1 and a second substrate W2 are bonded at a bonding surface P. Each of the first substrate W1 and the second substrate W2 for use in this embodiment has a circular shape. The laminated substrate Ws of this embodiment has a structure in which a first substrate W1 and a second substrate W2 of the round type shown inFIG.1Bare bonded, while in one embodiment, the laminated substrate Ws may have a structure in which a first substrate W1 and a second substrate W2 of the straight type shown inFIG.1Aare bonded. In this specification, the edge portion of the laminated substrate Ws refers to an outer periphery of the laminated substrate Ws including the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2. The edge portions E1 and E2 may be called bevel portions. A gap G is formed between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2. The gap G is formed around the entire circumference of the laminated substrate Ws.

FIG.3is a plan view showing an embodiment of a substrate processing apparatus1, andFIG.4is a side view showing an embodiment of the substrate processing apparatus1. The substrate processing apparatus1is an apparatus for applying a filler F to a laminated substrate Ws having a first substrate W1 and a second substrate W2 which have been bonded to each other. The substrate processing apparatus1includes a filler application module9configured to apply the filler F to the laminated substrate Ws, and an operation controller10configured to control operations of the filler application module9. The filler application module9includes a substrate holder2configured to hold the laminated substrate Ws, an application device3configured to apply the filler F, a curing device4configured to cure the applied filler F, and an infrared imaging device5configured to generate an image of an edge portion of the laminated substrate Ws.

The substrate holder2includes a stage configured to hold a back surface of the laminated substrate Ws by vacuum suction. The filler application module9further includes a rotating shaft7coupled to a central portion of the substrate holder2, and a rotating mechanism8configured to rotate the substrate holder2and the rotating shaft7. The laminated substrate Ws is placed on the substrate holder2such that the center of the laminated substrate Ws is aligned with a central axis of the rotating shaft7. The rotating mechanism8includes a motor (not shown). As shown inFIG.3, the rotating mechanism8is configured to rotate the substrate holder2and the laminated substrate Ws together in a direction shown by an arrow about a central axis Cr of the laminated substrate Ws.

The application device3is located radially outwardly of the laminated substrate Ws placed on the substrate holder2, and is configured to apply the filler F to the gap G between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2 of the laminated substrate Ws.FIG.5is a schematic diagram showing an embodiment of the application device3. The application device3includes a syringe21for injecting the filler F, a piston22movable reciprocally in the syringe21, and a horizontal moving mechanism (not shown) configured to move the syringe21toward and away from the laminated substrate Ws. This horizontal moving mechanism allows the application device3to adjust a distance between the laminated substrate Ws and a filler emitting port21aof the application device3. In one embodiment, the application device3may omit the horizontal moving mechanism. In this case, the distance between the laminated substrate Ws and the filler emitting port21ais determined in advance such that the filler F is appropriately injected into the gap G of the laminated substrate Ws.

The syringe21has a hollow structure and is configured to be filled with the filler F therein. The piston22is arranged in the syringe21. The syringe21has the filler emitting port21afor emitting the filler F at its tip. The tip of the syringe21including the filler emitting port21amay be configured to be detachable. A shape of the filler emitting port21ais selected to be an appropriate shape depending on physical properties (e.g., viscosity, etc.) of the filler F to be applied. The filler emitting port21ais arranged so as to face the gap G between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2.

The application device3is coupled to a gas supply source via a gas supply line25. When gas (e.g., dry air or nitrogen gas) is supplied from the gas supply source into the syringe21, the piston22moves forward in the syringe21. The forward movement of the piston22causes the filler F in the syringe21to be emitted through the filler emitting port21a.

A pressure regulator26and an on-off valve27are disposed in the gas supply line25. The on-off valve27is an actuator-driven valve, such as an electric valve or a solenoid valve. When the on-off valve27is opened, the gas is supplied from the gas supply source to the application device3, so that the application device3applies the filler F to the laminated substrate Ws. When the on-off valve27is closed, the supply of the gas to the application device3is stopped, so that the applying of the filler F is stopped. The pressure regulator26can regulate an amount of the filler F to be emitted from the filler emitting port21aper unit time by regulating a pressure of the gas to be supplied from the gas supply source to the application device3. Operations of the pressure regulator26and the on-off valve27are controlled by the operation controller10.

In one embodiment, the application device3may include a screw feeder instead of the combination of the syringe21and the piston22.

As shown inFIGS.3and4, the curing device4is located radially outwardly of the laminated substrate Ws placed on the substrate holder2. The curing device4is disposed downstream of the application device3in a rotating direction of the laminated substrate Ws, and is configured to cure the filler F that has been applied to the laminated substrate Ws by the application device3. Curing of the filler F by the curing device4is performed while the laminated substrate Ws is rotated. In this embodiment, the filler F has thermosetting property. An example of such filler is a thermosetting resin.

The curing device4is an air heater, which is configured to emit hot air blowing toward the filler F applied to the laminated substrate Ws. The curing device4is configured to be able to regulate pressure and temperature of the hot air blowing toward the filler F. The filler F heated with the hot air is cured by a crosslinking reaction. When the filler F contains a solvent, the solvent is volatilized by being heated. The curing device4is not limited to the air heater, and may be a lamp heater or other configuration as long as the curing device4can heat and cure the filler F.

In this embodiment, the filler F has thermosetting property, while in one embodiment, the filler F may have ultraviolet curable property. In this case, the curing device4may be a UV irradiation device configured to cure the filler F by emitting ultraviolet ray. When the filler F contains a solvent, the curing device4may heat the filler F to volatilize the solvent with an air heater or the like, in addition to the UV irradiation device.

The infrared imaging device5is disposed downstream of the curing device4in the rotating direction of the laminated substrate Ws. The infrared imaging device5is configured to generate an image including the filler F applied to the laminated substrate Ws by the application device3and cured by the curing device4. A distance between the infrared imaging device5and the curing device4is shorter than a distance between the infrared imaging device5and the application device3. The infrared imaging device5is located above the edge portion of the laminated substrate Ws, and is configured to generate an image of the edge portion of the laminated substrate Ws. More specifically, the infrared imaging device5emits infrared light to the edge portion of the laminated substrate Ws, receives infrared light reflected from the edge portion of the laminated substrate Ws, and generates the image of the edge portion of the laminated substrate Ws. An example of the infrared imaging device5is an infrared microscope.

FIG.6is a schematic diagram showing a manner in which the infrared imaging device5generates an image. The infrared imaging device5emits the infrared light approximately perpendicularly to the bonding surface P of the first substrate W1 and the second substrate W2 of the laminated substrate Ws. The infrared imaging device5generates an image of an imaging region R including the filler F applied to the laminated substrate Ws by the application device3and cured by the curing device4. Generating of the image by the infrared imaging device5may be performed while the laminated substrate Ws is rotated. The infrared light has a wavelength that passes through silicon. In this embodiment, the first substrate W1 and the second substrate W2 are basically made of silicon wafers, and the infrared light emitted from the infrared imaging device5is transmitted through the first substrate W1 and the second substrate W2. Since the infrared light does not pass through the filler F, the infrared imaging device5can generate the image of the imaging region R including the filler F from the infrared light reflected from the edge portion of the laminated substrate Ws.

The operation controller10is configured to control operations of the filler application module9configured as described above. The filler application module9including the application device3, the curing device4, the infrared imaging device5, the rotating mechanism8, the pressure regulator26, and the on-off valve27is electrically coupled to the operation controller10.

The operation controller10is composed of at least one computer. The operation controller10includes a memory10astoring programs therein for controlling the operations of the filler application module9, and a processor10bconfigured to perform arithmetic operations according to instructions contained in the programs. The memory10aincludes a main memory, such as a random-access memory (RAM), and an auxiliary memory, such as a hard disk drive (HDD) or a solid state drive (SSD).

Examples of the processor10binclude a CPU (central processing unit) and a GPU (graphic processing unit). However, the specific configuration of the operation controller10is not limited to these examples.

The infrared imaging device5generates the image of the edge portion of the laminated substrate Ws at a preset measurement point while the laminated substrate Ws makes one revolution. The number of measurement points may be one, or two or more.FIG.7is a diagram showing an example of measurement points set on the laminated substrate Ws. In this embodiment, the number of measurement points is four.

As shown inFIG.7, the four measurement points M1 to M4 are located in the edge portion of the laminated substrate Ws at equal intervals around the central axis Cr of the laminated substrate Ws. The operation controller10has location information (e.g., angle information) on a starting point for application of the filler F and the measurement points M1 to M4. The laminated substrate Ws rotates in a direction shown by an arrow. When the starting point for application of the filler F is located at the measurement point M1, the application device3starts applying of the filler F from the measurement point M1, and then the filler F is continuously applied to the edge portion of the laminated substrate Ws. The filler F may be applied while the laminated substrate Ws rotates multiple times depending on a total amount of the filler F to be applied.

Similarly, the curing device4continuously cures the filler F applied to the edge portion of the laminated substrate Ws. Furthermore, the infrared imaging device5generates images of the edge portion of the laminated substrate Ws at the measurement points in an order of the measurement points M1, M2, M3, and M4. The operation controller10determines the filling state of the filler F applied to the gap G (seeFIG.5) between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2 based on the generated images. The operation controller10instructs the application device3to terminate the application of the filler F at an appropriate timing based on the determined filling state of the filler F.

Next, a method of determining the filling state of the filler F will be described.FIG.8Ais an enlarged cross-sectional view of the edge portion of the laminated substrate during filling of the filler F.FIG.8Bis a diagram showing an image of the edge portion of the laminated substrate Ws shown inFIG.8A. The edge portion of the laminated substrate Ws shown inFIG.8Acorresponds to the imaging region R shown inFIG.6.FIG.8Bshows the image of the imaging region R generated by the infrared imaging device5disposed above the edge portion of the laminated substrate Ws. In this embodiment, the image generated by the infrared imaging device5is a two-dimensional image, while in one embodiment, the image generated by the infrared imaging device5may be a three-dimensional image.

InFIG.8A, a width x1 is a radial width of a portion where the first substrate W1 and the second substrate W2 are bonded in the imaging region R. A width x2 is a radial width of the gap G between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2. A width x3 is a radial width of the filler F applied to the gap G.

The widths x1 to x3 shown inFIG.8Bcorrespond to the widths x1 to x3 shown inFIG.8A. Regions Rn corresponding to portions where the filler F is not present appear on the image with a color close to white, because the infrared light emitted from the infrared imaging device5passes through the second substrate W2 and the first substrate W1. A region Rf corresponding to a portion where the filler F is present appears on the image with a color close to black, because the infrared light emitted from the infrared imaging device5passes through the second substrate W2 and is reflected from the filler F.

The operation controller10determines the filling state of the filler F applied to the gap G between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2 based on the image generated by the infrared imaging device5. More specifically, the operation controller10determines the filling state based on a size of the filler F in a preset target region T on the image. The target region T may be a part of the image or the entire image. As shown inFIG.8B, the target region T of this embodiment is a region having a width of x1+x2 in the radial direction and a length of y in a direction perpendicular to the radial direction. In one embodiment, the target region T may be set to a region (indicated by a reference symbol Tx) having the width of x2 in the radial direction and the length of y in the direction perpendicular to the radial direction. The target region T is not limited as long as the entirety of the filler F is present in the radial width of the target region T.

In the laminated substrate Ws shown inFIG.8A, the filler F has been applied to the laminated substrate Ws with the width x3 of the filler F in the radial direction. The filling of the filler F is completed when the filler F is applied until the width of the filler F in the radial direction reaches x2. Therefore, the filling state of the filler F of this embodiment is “filling is not yet completed”. When the size of the filler F in the target region T (i.e., an area of the region Rf) is smaller than a predetermined threshold value, the operation controller10determines that the filling state is “filling is not yet completed”. In this embodiment, the predetermined threshold value is set to the size of the filler F in the target region T when the width of the filler F in the radial direction is x2 (i.e., the area of the region Rf when the width of the filler F in the radial direction is x2).

FIG.9Ais an enlarged cross-sectional view of the edge portion of the laminated substrate Ws after filling of the filler F is completed.FIG.9Bis a diagram showing an image of the edge portion of the laminated substrate Ws shown inFIG.9A. Details of this embodiment, which will be not particularly described, are the same as those of the embodiment described with reference toFIGS.8A and8B, and duplicated descriptions will be omitted. InFIG.9A, a width x1 is a radial width of the portion where the first substrate W1 and the second substrate W2 are bonded in the imaging region R. A width x2 is a radial width of the gap G between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2. A width x3 is a radial width of the filler F applied to the gap G.

The widths x1 to x3 shown inFIG.9Bcorrespond to the widths x1 to x3 shown inFIG.9A. A region Rn corresponding to a portion where the filler F is not present appears on the image with a color close to white, because the infrared light emitted from the infrared imaging device5passes through the second substrate W2 and the first substrate W1. A region Rf corresponding to a portion where the filler F is present appears on the image with a color close to black, because the infrared light emitted from the infrared imaging device5passes through the second substrate W2 and is reflected from the filler F.

The operation controller10determines the filling state of the filler F applied to the gap between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2 based on the image generated by the infrared imaging device5. More specifically, the operation controller10determines the filling state based on the size of the filler F in the target region T on the image.

In the laminated substrate Ws shown inFIG.9A, the filler F has been applied to the laminated substrate Ws with the width x3 of the filler F in the radial direction. The filling of the filler F is completed when the filler F is applied until the width of the filler F in the radial direction reaches x2. Therefore, the filling state of the filler F of this embodiment is “filling has been completed”. When the size of the filler F in the target region T (i.e., an area of the region Rf) is equal to or larger than a predetermined threshold value, the operation controller10determines that the filling state is “filling has been completed”. In this embodiment, the predetermined threshold value is set to the size of the filler F in the target region T when the width of the filler F in the radial direction is x2 (i.e., the area of the region Rf when the width of the filler F in the radial direction is x2).

The operation controller10instructs the application device3to terminate the application of the filler F based on the determined filling state of the filler F. More specifically, when the operation controller10determines that the filling state of the filler F is “filling is not yet completed”, the operation controller10instructs the filler application module9to continue the application of the filler F by the application device3. When the operation controller10determines that the filling state of the filler F is “filling has been completed”, the operation controller10instructs the filler application module9to terminate the application of the filler F by the application device3.

FIG.10is a flowchart showing an embodiment of a substrate processing method.

In step S101, the operation controller10instructs the rotating mechanism8of the filler application module9to rotate the substrate holder2and the laminated substrate Ws at a predetermined rotation speed.

In step S102, the operation controller10instructs the on-off valve27of the filler application module9to open the on-off valve27to cause the gas to be supplied from the gas supply source to the application device3. With this operation, the filler F is injected into the gap G between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2 of the rotating laminated substrate Ws.

In step S103, the operation controller10instructs the curing device4of the filler application module9to heat the laminated substrate Ws to cure the applied filler F.

In step S104, the operation controller10instructs the infrared imaging device5of the filler application module9to generate an image of the edge portion of the laminated substrate Ws at measurement point(s) on the laminated substrate Ws.

In step S105, the operation controller10compares a size of the filler F in the target region T on the image generated by the infrared imaging device5with a predetermined threshold value.

When the size of the filler F in the target T is smaller than the predetermined threshold value, the operation controller10determines that the filling state is “filling is not yet completed” (step S106-1). When the operation controller10determines that the filling state is “filling is not yet completed”, the operation controller10instructs the filler application module9to continue the application of the filler F by the application device3, and repeats the steps S102to S105.

When the size of the filler F in the target T is equal to or larger than the predetermined threshold value, the operation controller10determines that the filling state is “filling has been completed” (step S106-2). When the operation controller10determines that the filling state is “filling has been completed”, the operation controller10instructs the filler application module9to terminate the application of the filler F. When the starting point for application of the filler F reaches an applying position of the application device3, the operation controller10may instruct the filler application module9to stop the application of the filler F.

According to this embodiment, since the distance between the infrared imaging device5and the curing device4is shorter than the distance between the infrared imaging device5and the application device3, the determination of the filling state of the filler F is performed immediately after the curing of the filler F by the curing device4. Therefore, the filling state of the filler F can be monitored in real time, and the application of the filler F can be terminated at an appropriate timing. As a result, appropriate filling of the filler F can be achieved.

In one embodiment, the operation controller10may compare the size of the filler F in the target region T with the predetermined threshold value to determine the filling state after the operations of the application device3and the curing device4are stopped (step S105). In this case, when the filling state is determined to be “filling is not yet completed” (step S106-1), the operation controller10may instruct the filler application module9to start the operations of the application device3and the curing device4again to additionally apply the filler F by the application device3(step S102), and may repeat the steps S103to S105.

In one embodiment, the additional application of the filler F may be performed only to a part of the edge portion of the laminated substrate Ws based at filling states of the filler F at measurement points and location information on the measurement points. For example, the operation controller10may determine filling states of the filler F at the measurement points M1 to M4 shown inFIG.7. When the operation controller10determines that the filling state at the measurement point M1 is “filling is not yet completed” and that the filling states at the measurement points M2 to M4 are “filling has been completed”, the operation controller10may instruct the filler application module9to perform additional application of the filler F only to the measurement point M1.

Next, another embodiment of the substrate processing method will be described.FIG.11Ais an enlarged cross-sectional view of the edge portion of the laminated substrate Ws with voids B in the filler F. The voids B are pores formed in the filler F that has been applied to the laminated substrate Ws.FIG.11Bis a diagram showing an image of the edge portion of the laminated substrate Ws shown inFIG.11A. Details of this embodiment, which will be not particularly described, are the same as those of the embodiment described with reference toFIGS.8A and8B, and duplicated descriptions will be omitted. The voids B may be generated in the applied filler F depending on an applying condition for the filler F. InFIG.11A, a width x1 is a radial width of the portion where the first substrate W1 and the second substrate W2 are bonded in the imaging region R. A width x2 is a radial width of the gap G between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2. A width x3 is a radial width of the filler F applied to the gap G.

The widths x1 to x3 shown inFIG.11Bcorrespond to the widths x1 to x3 shown inFIG.11A. Regions Rn corresponding to portions where the filler F is not present appear on the image with a color close to white, because the infrared light emitted from the infrared imaging device5passes through the second substrate W2 and the first substrate W1. A region Rf corresponding to a portion where the filler F is present appears on the image with a color close to black, because the infrared light emitted from the infrared imaging device5passes through the second substrate W2 and is reflected from the filler F. The voids B generated in the filler F appear on the image with a color close to white.

The operation controller10determines the filling state of the filler F applied to the gap G between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2 based on the image generated by the infrared imaging device5. More specifically, when the operation controller10detects a void B in the filler F (i.e., the region Rf) in the image, the operation controller10determines that the filling state is “void has been generated”. Furthermore, the operation controller10counts the number of voids B on the image, and when the number of voids B has reached a preset acceptable value, the operation controller10determines that “abnormality has occurred”.FIG.12is a flowchart showing another embodiment of the substrate processing method. Steps S201to S204of this embodiment are the same as the steps S101to S104of the embodiment described with reference toFIG.10, and duplicated descriptions will be omitted.

In step S205, the operation controller10determines whether a void B has been generated in the filler F based on the image generated by the infrared imaging device5.

When the void B has been generated in the filler F, the operation controller10determines that the filling state is “void has been generated” (step S206). When the operation controller10determines that the void B is not generated in the filler F (“No” in the step205), the operation controller10instructs the filler application module9to continue the application of the filler F, and repeats the steps S202to S205.

When the void B has been generated in the filler F (“Yes” in the step205), the operation controller10counts the number of voids B on the image generated by the infrared imaging device5(step S207).

In step S208, the operation controller10determines whether the number of voids B has reached a predetermined acceptable value. When the number of voids B has reached the acceptable value, the operation controller10determines that “abnormality has occurred” (step S209). When the operation controller10determines that “abnormality has occurred”, the operation controller10instructs the filler application module9to terminate the application of the filler F.

When the number of voids B has not reached the predetermined acceptable value (“No” in the step S208), the operation controller10instructs the filler application module9to continue the application of the filler F, and repeats the steps S202to S205.

According to this embodiment, since the distance between the infrared imaging device5and the curing device4is shorter than the distance between the infrared imaging device5and the application device3, the determination of the filling state of the filler F is performed immediately after the curing of the filler F by the curing device4. Therefore, the filling state of the filler F can be monitored in real time, so that an abnormality can be quickly detected.

In one embodiment, the operation controller10may detect a void B in the filler F based on a rate of increase in the size of the filler F in the target region T (seeFIG.11B) on the image. The rate of increase in the size of the filler F is an amount of increase in the size of the filler F per unit time in the target region T. If a void B is generated in the filler F, the radial width x3 (seeFIGS.11A and11B) of the filler F applied to the gap G becomes larger than that when no voids B are generated. Thus, in this embodiment, the operation controller10determines that the filling state is “void has been generated” when the rate of increase in the size of the filler F in the target region T (i.e., the rate of increase in the area of the region Rf) is larger than a predetermined reference value. The predetermined reference value may be set, for example, based on a rate of increase in the size of the filler F when no voids B are generated in the filler F, which is obtained in advance through an experiment or the like.

The rate of increase in the size of the filler F can be determined from the size of the filler F in the target region T on the image generated by the infrared imaging device5each time the laminated substrate Ws makes one revolution. For example, the operation controller10calculates an amount of increase in the size of the filler F from a size of the filler F in the target region T on an image when the laminated substrate Ws makes one revolution from the start of application of the filler F, and a size of the filler F in the target region T on an image when the laminated substrate Ws further makes one revolution. The operation controller10calculates the amount of increase in the size of the filler F per unit time, i.e., the rate of increase in the size of the filler F, by dividing the calculated amount of increase in the size of the filler F by a time for the laminated substrate to make one revolution.

Furthermore, when the rate of increase in the size of the filler F in the target region T is larger than the reference value, the operation controller10may instruct the filler application module9to terminate the application of the filler F.

If many voids are generated in the filler F, a volume of the applied filler F may be larger than expected. Thus, in one embodiment, when the size of the filler F in the target region T (i.e., the area of the region Rf) is larger than a preset upper limit, the operation controller10may determine that the filling state is “void has been generated”. Furthermore, when the size of the filler F in the target region T (i.e., the area of the region Rf) is larger than the preset upper limit, the operation controller10may instruct the filler application module9to terminate the application of the filler F.

In one embodiment, the operation controller10may change an applying condition for the filler F based on the filling state of the filler F. The applying condition includes at least one of a total amount of the filler F to be applied, a shape of the filler emitting port21a(seeFIG.5) of the application device3, a distance between the laminated substrate Ws and the filler emitting port21a, an amount of the filler F to be emitted from the filler emitting port21aper unit time, and a rotation speed of the laminated substrate Ws. In one embodiment, the applying condition may further include wind pressure and temperature of the hot air to be emitted from the curing device4.

In one embodiment, the changing of the applying condition may be performed only at a part of the edge portion of the laminated substrate Ws based on filling states of the filler F at measurement points and location information on the measurement points. The operation controller10determines the filling states of the filler F at the measurement points M1 to M4 shown inFIG.7. When the operation controller10determines that the filling state at the measurement point M1 is “filling failure” and that the filling states at the measurement points M2 to M4 are “filling is not yet completed”, the operation controller10may change only an applying condition for the filler F at the measurement point M1 based on the location information on the measurement points M1 to M4.

According to this embodiment, since the distance between the infrared imaging device5and the curing device4is shorter than the distance between the infrared imaging device5and the application device3, the determination of the filling state of the filler F is performed immediately after the curing of the filler F by the curing device4. Therefore, the filling state of the filler F can be monitored in real time, so that the applying condition can be adjusted to achieve an optimal filling state.

In one embodiment, the filling state of the filler F applied to the laminated substrate Ws may be reflected in an applying condition for the filler F in a next laminated substrate. As a result, when the next laminated substrate has the same configuration as that of the laminated substrate Ws, the filler F can be applied appropriately without adjusting the applying condition during application of the filler F.

Next, still another embodiment of the substrate processing method will be described.FIG.13Ais an enlarged cross-sectional view of the edge portion of the laminated substrate Ws with a filling failure of the filler F.FIG.13Bis a diagram showing an image of the edge portion of the laminated substrate Ws shown inFIG.13A. Details of this embodiment, which will be not particularly described, are the same as those of the embodiment described with reference toFIGS.8A and8B, and duplicated descriptions will be omitted. InFIG.13A, a width x1 is a radial width of the portion where the first substrate W1 and the second substrate W2 are bonded in the imaging region R. A width x2 is a radial width of a portion to which the filler F is not applied in a region located radially inwardly of the filler F. A width x3 is a radial width of the filler F applied to the gap G. A width x4 is a radial width of a portion to which the filler F is not applied in a region located radially outwardly of the filler F, i.e., a width from a radially-outermost end of the filler F to a radially-outermost end of the laminated substrate Ws.

The widths x1 to x4 shown inFIG.13Bcorrespond to the widths x1 to x4 shown inFIG.13A. Regions Rn where the filler F is not present appear on the image with a color close to white, because the infrared light emitted from the infrared imaging device5passes through the second substrate W2 and the first substrate W1. A region Rf where the filler F is present appears on the image with a color close to black, because the infrared light emitted from the infrared imaging device5passes through the second substrate W2 and is reflected from the filler F.

The operation controller10determines the filling state of the filler F applied to the gap G between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2 based on the image generated by the infrared imaging device5. More specifically, the operation controller10determines the filling state based on a position of the filler F on the image.

The laminated substrate Ws shown inFIG.13Ahas a filling failure of the filler F, and the filler F is not applied to the portion having the width x2 in the radial direction. In this case, as shown inFIG.13B, a radially-innermost end position Lf of the region Rf is located radially outwardly of a radially-innermost end position L0 of the gap G between the edge portion E1 of the first substrate W1 and the edge portion E2 of the second substrate W2. When a the radially-innermost end position of the filler F (i.e., the radially-innermost end position Lf of the region Rf) is located radially outwardly of the radially-innermost end position L0 of the gap G, the operation controller10determines that the filling state is “filling failure”. When the operation controller10determines that the filling state of the filler F is “filling failure”, the operation controller10instructs the application device3to terminate the application of the filler F.

According to this embodiment, since the distance between the infrared imaging device5and the curing device4is shorter than the distance between the infrared imaging device5and the application device3, the determination of the filling state of the filler F is performed immediately after the curing of the filler F by the curing device4. Therefore, the filling state of the filler F can be monitored in real time, so that a filling failure can be quickly detected.

The previous description of embodiments is provided to enable a person skilled in the art to make and use the present invention. Moreover, various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles and specific examples defined herein may be applied to other embodiments.

Therefore, the present invention is not intended to be limited to the embodiments described herein but is to be accorded the widest scope as defined by limitation of the claims.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a substrate processing method and a substrate processing apparatus for suppressing cracking and chipping of a laminated substrate manufactured by bonding substrates, and more particularly to a technique of applying a filler to a gap formed between edge portions of the substrates constituting the laminated substrate.

REFERENCE SIGNS LIST