JP2009130218A - Bonding device and bonding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adequately bond a wafer and a support plate. <P>SOLUTION: The bonding device 22 includes an adhesive applying part 4 for forming an adhesive layer 2 on a surface of the support plate 1, and a sticking part 7 for bonding the wafer 3 to the adhesive layer 2 on the surface of the support plate 1. Thus, air bubbles generated between the adhesive layer 2 and the wafer 3 are prevented, and a non-bonded part of the adhesive layer 2 and the wafer 3 can be prevented. Thereby, the support plate 1 and the wafer 3 can be adequately bonded through the adhesive layer 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pasting apparatus and a pasting method for pasting a substrate and a support plate that supports the substrate.

  As mobile phones, digital AV devices, IC cards, etc. have become more sophisticated, there is an increasing demand for higher integration of chips in packages by reducing the size and thickness of semiconductor silicon chips (hereinafter referred to as chips). ing. In order to realize high integration of chips in the package, it is necessary to reduce the thickness of the chip to a range of 25 to 150 μm.

  However, since a semiconductor wafer (hereinafter referred to as a wafer) serving as a base of a chip is thinned by grinding, its strength is weakened and the wafer is likely to be cracked or warped. Further, since it is difficult to automatically transport a wafer whose strength has been reduced by making it thin, it has to be transported manually, and the handling thereof is complicated.

  Therefore, a wafer support system has been developed that maintains the strength of the wafer and prevents the occurrence of cracks and warpage of the wafer by bonding a plate made of glass, hard plastic, or the like, to the wafer to be ground. . Since the strength of the wafer can be maintained by the wafer support system, the transport of the thinned semiconductor wafer can be automated.

When reinforcing the strength of a wafer using such a wafer support system, the support plate and the wafer are conventionally bonded together by the process shown in FIG. As shown in FIG. 6, an adhesive 102 is applied to the circuit forming surface of the wafer 101, and a support plate 103 is bonded to the surface of the wafer 101 on which the adhesive 102 has been applied. Then, after the wafer bonded to the support plate is thinned by grinding in a grinding process, the support plate is peeled from the wafer by dissolving the adhesive. Patent Documents 1 and 2 describe such a method of attaching the wafer 101 and the support plate 103.
JP 2005-191550 A (published July 14, 2005) Japanese Patent Laying-Open No. 2006-156683 (released on June 15, 2006)

  The circuit pattern formed on the wafer is not uniform, and there are various patterns according to the application. In addition, an uneven pattern with a large height difference may be formed on the circuit formation surface. For this reason, when the adhesive 102 is applied to the circuit forming surface of the wafer 101 as in the conventional bonding process described in Patent Documents 1 and 2, as shown in FIG. The problem of being trapped. When the support plate 103 is pasted while the bubbles are confined between the adhesive 102 and the wafer 101, when the wafer 101 is thinned, the thickness of the wafer 101 becomes uneven due to the presence of the bubbles, and cracks are generated. May occur. Further, when the wafer 101 is processed under reduced pressure, the bubbles may expand and the wafer 101 may be damaged.

  Further, in the circuit pattern formed on the wafer 101, as shown in FIG. 8, the uneven pattern is densely formed in the central portion of the wafer 101, and the circuit pattern formed on the outer peripheral portion of the wafer 101 is sparse. There is. For this reason, when the adhesive 102 is applied to the circuit forming surface of the wafer 101, the thickness of the adhesive layer 102 applied to the outer peripheral portion of the wafer 101 having a sparse circuit pattern is reduced and applied to the wafer 101. Unevenness occurs in the thickness of the adhesive layer 102. As a result, when the support plate 103 is bonded to the adhesive 102, the wafer 101 and the support plate 103 cannot be bonded sufficiently, and an unbonded portion is generated between the wafer 101 and the support plate 103. End up.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a sticking apparatus and a sticking method for appropriately sticking a wafer and a support plate using an adhesive.

  In order to solve the above-mentioned problems, the sticking device according to the present invention is a sticking device for sticking a substrate and a support plate that supports the substrate, and forms an adhesive layer on the support plate. And an attaching means for attaching the substrate onto the adhesive layer.

  Moreover, in order to solve the above problems, the sticking method according to the present invention is a sticking method for sticking a substrate and a support plate that supports the substrate, and an adhesive layer that forms an adhesive layer on the support plate. It includes a forming step and an attaching step of attaching a substrate on the adhesive layer.

  According to said structure, since the sticking apparatus is equipped with the adhesive bond layer formation means which forms an adhesive bond layer on a support plate, the adhesive bond layer for bonding a board | substrate and a support plate on a support plate is provided. Can be formed. Unlike the substrate, since the circuit pattern is not formed on the support plate, the adhesive layer can be formed without being affected by the density of the circuit pattern, and the thickness of the adhesive layer is uneven. It can be prevented from occurring. As a result, when the substrate is attached to the adhesive layer on the support plate, an unadhered portion does not occur between the substrate and the adhesive layer, and the support plate and the substrate can be reliably attached.

  In addition, since the adhesive layer formed on the support plate is not affected by the difference in height of the circuit pattern, it is possible to prevent the problem that bubbles are trapped in the adhesive layer. Then, when the substrate is attached to the adhesive layer on the support plate, the adhesive layer enters so as to extrude the air present in the concave and convex portions on the substrate, so that bubbles are generated between the adhesive layer and the substrate. Can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Paste device 22)
FIG. 1 is a configuration diagram for explaining an embodiment of a configuration of a sticking device 22 according to the present invention. As shown in FIG. 1, the pasting device 22 includes an adhesive application unit 4 and a pasting unit 7. The sticking device 22 is a device for sticking the support plate (support plate) 1 and the wafer (substrate) 3. The sticking device 22 preferably includes an adhesive layer drying unit 5 and an adhesive layer cooling unit 6. Further, a support plate cassette 8 and a support plate alignment unit 9 may be further provided. In addition, it is preferable that the bonding part 7 is provided with the heating mechanism and the press mechanism.

  The affixing device 22 forms an adhesive layer on the surface of the support plate 1 in the adhesive application unit 4, and affixes the wafer 3 to the adhesive layer on the surface of the support plate 1 in the affixing unit 7, thereby supporting the wafer 3 and the support. The plate 1 is pasted.

  The pasting process by the pasting device 22 will be described below with reference to FIG. FIG. 2 is a conceptual diagram for explaining a pasting process by the pasting device 22 according to the present invention. As shown in FIG. 2, after the adhesive layer 2 is formed on the surface of the support plate 1, the adhesive layer 2 on the surface of the support plate 1 is attached to the circuit forming surface of the wafer 3. And paste.

  Thus, in the sticking device 22 according to the present invention, since the adhesive layer 2 is formed on the surface of the support plate 1, the adhesive layer 2 is not affected by the circuit pattern on the wafer 3 when the adhesive layer 2 is formed. It is possible to prevent bubbles from being generated in the layer 2. Then, by pressing the adhesive layer 2 against the circuit forming surface of the wafer 3, the adhesive layer 2 is formed without generating bubbles between the adhesive layer 2 and the wafer 3 as shown in FIG. The support plate 1 and the wafer 3 can be attached to each other. As a result, the wafer 3 can be reliably supported by the support plate 1 while the wafer 3 is processed in the subsequent process.

  Further, according to the sticking device 22 according to the present invention, the adhesive layer 2 is formed on the surface of the support plate 1, so that the thickness is uniform without being affected by the circuit pattern of the wafer 3 when the adhesive layer 2 is formed. An adhesive layer can be formed. Then, by pressing the adhesive layer 2 against the circuit forming surface of the wafer 3, as shown in FIG. 4, the adhesive layer 2 forms the circuit of the wafer 3 even in the outer peripheral portion where the circuit pattern of the wafer 3 is sparse. Since the adhesive layer 2 is bonded to the surface, it is possible to prevent an unbonded portion between the adhesive layer 2 and the wafer 3 and to sufficiently bond the support plate 1 and the wafer 3 through the adhesive layer 2. As a result, the wafer 3 can be reliably supported by the support plate 1 while the wafer 3 is processed in the subsequent process.

(Adhesive application part 4)
Next, a process of forming the adhesive layer 2 on the surface of the support plate 1 by the adhesive application unit 4 will be described.

  First, an adhesive is applied to the surface of the support plate 1 in the adhesive application unit 4. The adhesive is preferably a thermoplastic adhesive, and examples include, but are not limited to, novolac resin, epoxy resin, amide resin, silicon resin, acrylic resin, urethane resin, polystyrene, polyvinyl ether, and polyvinyl acetate. Not. By using a thermoplastic adhesive, the adhesive is baked in a later step to form the adhesive layer 2, and this adhesive layer 2 is thermocompression bonded to the wafer 3 to bond the adhesive layer 2 and the wafer 3 together. The attaching process can be easily performed.

  Next, the adhesive layer 2 is formed by spreading the adhesive applied to the surface of the support plate 1 on the surface of the support plate 1. As a method of forming the adhesive layer 2 on the surface of the support plate 1, for example, an open cup, a substantially sealed rotating cup, or the like is used to rotate the support plate 1 to centrifuge the adhesive applied to the support plate 1. A method of spreading by force and forming the adhesive layer 2 can be used. Alternatively, the adhesive layer 2 may be formed by attaching a film-like adhesive to the surface of the support plate 1.

  The layer thickness of the adhesive layer 2 formed on the surface of the support plate 1 is appropriately changed according to the height of the circuit pattern formed on the wafer 3. That is, the adhesive layer 2 is formed so as to completely cover the circuit pattern of the wafer 3 and to have a thickness sufficient to fill the gap between the patterns of the uneven circuit pattern and the pattern. At this time, the layer thickness of the adhesive layer 2 may be a thickness that does not contact the circuit formed on the wafer 3 when the adhesive layer 2 is pressure-bonded to the wafer 3 in a later step. Compared with the case where the adhesive layer 2 is formed on the wafer 3, the thickness of the adhesive layer 2 can be reduced.

  Next, in the adhesive layer drying unit 5, the adhesive layer 2 formed on the surface of the support plate 1 is dried. The adhesive layer 2 is baked at 110 ° C. to start drying the adhesive layer, and then the temperature is increased and further baking is performed at 150 ° C. and 200 ° C. Then, in the adhesive layer cooling unit 6, the heated support plate 1 and the adhesive layer 2 on the surface thereof are cooled. Thereby, a dry film of the adhesive layer is formed. In addition, when the adhesive layer 2 having a sufficient thickness is not formed by one adhesive layer 2 forming step, the above-described forming step may be repeated a plurality of times.

  Here, examples of the support plate 1 on which the adhesive layer 2 is formed to be bonded to the wafer 3 include, but are not limited to, a glass plate, an acrylic plate, a silicon plate, and a ceramic plate. The support plate 1 may be a perforated support plate 1 having a through hole. When the perforated support plate 1 is used, in order to prevent the adhesive applied to the support plate 1 from flowing out of the through hole, a tape or the like is attached to the surface of the support plate 1 on which the adhesive is not applied to the through hole. It is preferable to block.

  Thus, since the adhesive application part 4 applies an adhesive to the support plate 1 having a substantially flat surface to form the adhesive layer 2, it is easy for bubbles to be generated in the formed adhesive layer 2. Can be prevented. Further, since the adhesive is applied to the support plate 1 having a substantially flat surface and the applied adhesive is spread on the surface of the support plate 1 to form the adhesive layer 2, the adhesive layer 2 having a more uniform layer thickness is formed. Can be formed. As a result, it is possible to prevent an unbonded portion from being formed between the adhesive layer 2 and the wafer 3 and to securely bond the support plate 1 and the wafer 3.

  Further, as shown in FIG. 5, the adhesive layer 2 may be formed on both the support plate 1 and the wafer 3 in the adhesive application unit 4. At this time, the adhesive application unit 4 applies an adhesive to both the surface of the support plate 1 and the circuit forming surface of the wafer 3, and spreads the adhesive on the surface of the support plate 1 and the circuit forming surface of the wafer 3. Adhesive layer 2 is formed on both surfaces. Then, the adhesive layer 2 formed on the surface of the support plate 1 and the circuit forming surface of the wafer 3 is baked in the adhesive layer drying unit 5 and cooled in the adhesive layer cooling unit 6 as described above, thereby supporting the support plate. An adhesive layer 2 is formed on both 1 and the wafer 3.

  Thus, when the adhesive layer on the surface of the support plate 1 and the adhesive layer on the circuit forming surface of the wafer 3 are bonded to each other in a later step, the support plate 1 or the wafer 3 and the adhesive layer 2 are bonded together. Since no unbonded portion is generated, the support plate 1 and the wafer 3 can be bonded more reliably.

(Bonding part 7)
Next, the process of bonding the support plate 1 and the wafer 3 by the bonding unit 7 will be described. In the following, a bonding process between the support plate 1 and the wafer 3 in the case where the adhesive layer 2 is formed only on the surface of the support plate 1 will be described. The adhesive is applied to both the surface of the support plate 1 and the circuit forming surface of the wafer 3. Even when the layer 2 is formed, the support plate 1 and the wafer 3 can be similarly bonded.

  First, in the bonding unit 7, the wafer 3 is placed on a stage that has been heated in advance with the circuit pattern forming surface facing up, and the adhesive layer 2 forming surface of the support plate 1 and the wafer 3 are heated while the wafer 3 is heated. The support plate 1 is pressed onto the wafer 3 by overlapping the circuit pattern forming surface and pressing the support plate 1 and the wafer 3 while being heated by a pressing means having a heating mechanism. In this case, when the support plate 1 is overlaid on the wafer 3, it is necessary to invert the support plate in advance. However, the inversion means is not particularly limited, and for example, the conveyance robot may have an inversion mechanism. Alternatively, it may be reversed by a reversing means installed separately.

  As a result, the adhesive layer 2 with increased fluidity enters between the circuit patterns of the wafer 3, and the wafer 3 can be attached so as to fill the irregularities on the surface of the wafer 3.

  Moreover, you may perform the said crimping | compression-bonding process in a pressure-reduced atmosphere. By bonding the wafer 3 onto the adhesive layer 2 in a reduced-pressure atmosphere, the adhesive layer 2 can enter the recess in a state where no air is present in the recess of the uneven pattern on the surface of the wafer 3. It is possible to more reliably prevent the generation of bubbles between the agent layer 2 and the wafer 3.

  In the heat treatment of the support plate 1, the adhesive layer 2 is heated to such a temperature that the adhesive layer 2 has fluidity that allows the adhesive layer 2 to enter the recesses of the uneven pattern of the wafer 3. The temperature of the adhesive layer 2 during the subsequent pressure bonding is preferably 23 to 300 ° C, and more preferably 200 ° C. If the temperature of the adhesive layer 2 at the time of pressure bonding is 23 ° C. or lower, sufficient fluidity to be bonded to the wafer 3 cannot be obtained, and if it is 300 ° C. or higher, the flowability of the adhesive layer 2 is too high. Since the shape of 2 cannot be maintained, it is not preferable. In addition, the temperature of the adhesive layer 2 at the time of pressure bonding is appropriately changed depending on the characteristics of the adhesive material constituting the adhesive layer 2, and it is preferable to obtain an appropriate temperature in advance by measurement.

In the above crimping step, the adhesive layer 2 enters the wafer 3 so as to completely fill the recesses of the concave / convex pattern, and the pressure is such that the support plate 1 does not contact the circuit forming surface of the wafer 3. The wafer 3 is pressure-bonded thereon. The pressure applied to the adhesive layer 2 when the wafer 3 is pressed onto the adhesive layer 2 is preferably 1 to 1500 kPa, more preferably 19.6 kPa, per 1 cm ² . When the pressure applied to the adhesive layer 2 at the time of pressure bonding is 1 kPa or less, the adhesive layer 2 does not sufficiently enter the recesses of the uneven pattern of the wafer 3, and when the pressure is 1500 kPa or more, the support plate 1 is in contact with the circuit forming surface of the wafer 3. This is not preferable because it may damage the forming surface. The pressure applied to the adhesive layer 2 at the time of pressure bonding is appropriately changed according to the characteristics of the adhesive material constituting the adhesive layer 2, the layer thickness and hardness (viscosity) of the adhesive layer 2 at the time of pressure bonding, and the like. It is preferable to obtain an appropriate pressure in advance by measurement.

  The heating time of the support plate 1 is adjusted so that the adhesive layer 2 has a desired temperature, and the pressing time is adjusted so that the adhesive layer 2 and the wafer 3 are sufficiently bonded as desired. To do. Appropriate heating time and pressing time may be obtained in advance by measurement.

  As described above, the attaching device 22 according to the present invention forms the adhesive layer 2 on the surface of the support plate 1 and attaches the wafer 3 to the adhesive layer 2, thereby attaching the support plate 1 and the wafer 3. wear. Since the surface of the support plate 1 is substantially flat as compared to the wafer 3 on which the uneven circuit pattern having a height difference is formed, the adhesive layer 2 is formed on the surface of the support plate 1 by forming the adhesive layer 2 on the surface of the support plate 1. 2 can be prevented from being generated.

  In addition, when the wafer 3 is attached to the adhesive layer 2, it is possible to prevent bubbles from being generated between the adhesive layer 2 and the wafer 3. Furthermore, the adhesive layer 2 can be formed uniformly by forming the adhesive layer 2 on the surface of the support plate 1. As a result, it is possible to prevent an unbonded portion between the adhesive layer 2 and the wafer 3 and securely attach the support plate 1 and the wafer 3.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The sticking apparatus according to the present invention can reliably support a wafer by a support plate, and can be suitably used for wafer processing such as thinning.

FIG. 1 is a configuration diagram illustrating an embodiment of a configuration of a sticking device according to the present invention. FIG. 2 is an explanatory diagram of a pasting process by the pasting apparatus according to the present invention. FIG. 3 is an explanatory diagram of a pasting process by the pasting apparatus according to the present invention. FIG. 4 is an explanatory diagram of a pasting process by the pasting apparatus according to the present invention. FIG. 5 is an explanatory diagram of a pasting process by the pasting apparatus according to the present invention. FIG. 6 is an explanatory diagram of a pasting process by a conventional pasting apparatus. FIG. 7 is an explanatory diagram of a pasting process by a conventional pasting apparatus. FIG. 8 is an explanatory diagram of a pasting process by a conventional pasting device.

Explanation of symbols

1 Support plate (support plate)
2 Adhesive layer 3 Wafer (substrate)
DESCRIPTION OF SYMBOLS 4 Adhesive application part 7 Bonding part 8 Support plate cassette 9 Support plate positioning part 10 Transfer robot 11 Wafer cassette 12 Wafer positioning part 22 Pasting apparatus

Claims (10)

A pasting device for pasting a substrate and a support plate for supporting the substrate,
An adhesive layer forming means for forming an adhesive layer on the support plate;
A pasting device for pasting the substrate on the adhesive layer.   The sticking apparatus according to claim 1, wherein the sticking means sticks the substrate on the adhesive layer in a reduced pressure atmosphere. The adhesive layer is composed of a thermoplastic adhesive,
The sticking apparatus according to claim 1, wherein the sticking means is a thermocompression bonding means for thermocompression bonding the substrate onto the adhesive layer.   The sticking apparatus according to claim 3, wherein the thermocompression bonding unit thermocompresses the substrate onto the adhesive layer when the temperature of the adhesive layer is 23 to 300 ° C. The thermocompression bonding means, sticking apparatus according to claim 3 or 4, wherein the adhesive layer 1 cm ² per characterized in that the substrate to the adhesive layer at a pressure of 1~1500kPa thermocompression bonding. The adhesive layer forming means forms an adhesive layer on the support plate and the substrate, respectively.
The sticking apparatus according to claim 1, wherein the sticking means sticks the adhesive layer on the support plate and the adhesive layer on the substrate together. The adhesive layers on the support plate and the substrate are each composed of a thermoplastic adhesive,
The sticking device according to claim 6, wherein the sticking means is a thermocompression bonding means for thermocompression bonding the adhesive layer on the substrate to the adhesive layer on the support plate.   The thermocompression bonding means heats the adhesive layer on the substrate to the adhesive layer on the support plate when the temperature of the adhesive layer on the support plate and the substrate is 23 to 300 ° C., respectively. The sticking device according to claim 7, wherein the sticking device is crimped. The thermocompression-bonding means thermocompression-bonds the adhesive layer on the substrate to the adhesive layer on the support plate at a pressure of 1 to 1500 kPa per 1 cm ² of the adhesive layer. The sticking device according to 1. A pasting method for pasting a substrate and a support plate for supporting the substrate,
An adhesive layer forming step of forming an adhesive layer on the support plate;
A pasting step of pasting a substrate on the adhesive layer.

Images