JP7640158B2 - Substrate bonding apparatus and substrate bonding method - Google Patents

Description

The present invention relates to a substrate bonding apparatus and a substrate bonding method.

Substrate bonding devices that bond multiple substrates together in a stacked state are known. One such substrate bonding device has been disclosed in which a first wafer is placed on a second wafer held on a stage, and a pressure force is applied from a pressure mechanism to the first wafer, thereby pressure bonding the first wafer and the second wafer together (see, for example, Patent Document 1).

JP 2007-301593 A

In the substrate bonding apparatus disclosed in Patent Document 1, the first and second wafers are aligned prior to pressure bonding them. At this time, the alignment mechanism performs alignment while the first and second wafers are supported from below by a support member. In the case of a first wafer with its functional surface facing downward, moving the first wafer for alignment may cause friction between the support member and the functional surface, which may lead to damage to the functional surface, generation of foreign matter, chip flying, etc.

The present invention aims to provide a substrate bonding apparatus and a substrate bonding method that can bond substrates together with good quality while minimizing damage to the functional surfaces of the substrates, generation of foreign matter, and chip flying when aligning the substrates.

In one aspect of the present invention, there is provided a substrate bonding apparatus comprising a lower plate, lift pins provided on the lower plate which support and raise and lower a substrate brought in, a holding section which receives and holds a previously brought in substrate from the lift pins, and an upper pressing section which is arranged above the lower plate and can abut against the upper surface side of the substrate held by the holding section, and which raises the later brought in substrate with the lift pins to bond the previously brought in substrate and the later brought in substrate together, the substrate bonding apparatus comprising: a support member provided on the lower plate which abuts against the outer periphery of the lower surface of the previously brought in substrate when the lift pins are lowered to support the substrate; and an alignment mechanism which positions the substrate by clamping the substrate supported by the support member in a direction along the surface of the substrate, and positions the substrate by clamping the later brought in substrate among the substrates to be bonded in a direction along the surface of the substrate while supported by the lift pins.
Also, according to an aspect of the present invention, there is provided a substrate bonding apparatus for bonding two substrates together, the substrate bonding apparatus comprising: a lower plate on a lower side; lift pins provided on the lower plate which support and raise and lower a substrate brought in; a holding section which receives and holds the substrate brought in earlier from the lift pins; an upper pressing section which is arranged above the lower plate and can abut against the upper surface side of the upper substrate of the two substrates to be bonded; a support member provided on the lower plate which abuts against the outer periphery of the lower surface of the substrate when the lift pins are lowered to support the substrate; and an alignment mechanism which positions the substrate by clamping the substrate supported by the support member in a direction along the surface of the substrate.

In one aspect of the present invention, there is provided a method for bonding two substrates, the method including supporting a loaded substrate with lift pins, receiving a previously loaded substrate from the lift pins and holding it with a holding section, passing the substrate from the lift pins to a support member abutting the outer periphery of the lower surface of the substrate, and supporting the upper substrate of the two substrates to be bonded with the support member, positioning the substrate by clamping the substrate supported by the support member in a direction along the surface of the substrate, and the lower substrate of the two substrates to be bonded is loaded later, and positioning the substrate by clamping the substrate in a direction along the surface of the substrate while supported by the lift pins.
Also, an aspect of the present invention provides a method for bonding two substrates, the method including supporting a loaded substrate with lift pins, passing the substrate from the lift pins to a support member abutting the outer periphery of the lower surface of the substrate and supporting the substrate with the support member, and positioning the substrate by clamping the substrate supported by the support member in a direction along the surface of the substrate.

According to this aspect of the present invention, since the functional surface of the substrate is not contacted when aligning the substrate, damage to the functional surface of the substrate and generation of foreign matter are suppressed, and the substrates can be bonded together with good quality.

FIG. 1 is a diagram showing an example of a substrate bonding apparatus according to a first embodiment. FIG. 2 is a view of the upper substrate as viewed from below. FIG. 2 is a cross-sectional view of the upper substrate. FIG. 4 is a plan view of the lower plate as viewed from above. 5 is a cross-sectional view taken along the line A-A in FIG. 4 . 4 is a flowchart showing an example of a substrate bonding method according to the embodiment. 6 is a flowchart showing an example of the substrate bonding method according to the embodiment. 13A and 13B show an example of the operation of the substrate bonding apparatus, in which the upper substrate is carried into the chamber and supported by lift pins. 11A and 11B are diagrams showing an example of the operation of the substrate bonding apparatus, in which an upper substrate is placed on a supporting member. 13A to 13C are diagrams showing an example of the operation of the substrate bonding apparatus, in which an alignment operation is performed on the upper substrate. 13A and 13B are diagrams showing an example of the operation of the substrate bonding apparatus, in which the upper substrate is held by a holding portion (suction pad). 13A and 13B show an example of the operation of the substrate bonding apparatus, in which the lower substrate is carried into the chamber and supported by lift pins. 13A to 13C are diagrams showing an example of the operation of the substrate bonding apparatus, in which a warp suppression bake process is performed on the lower substrate. 13A and 13B are diagrams showing an example of the operation of the substrate bonding apparatus, in which the lower substrate is supported by the lower plate. 13A to 13C are diagrams showing an example of the operation of the substrate bonding apparatus, in which an alignment operation is performed on the lower substrate. 13A to 13C are diagrams showing an example of the operation of the substrate bonding apparatus, in which the lift pins are raised to bond the upper substrate and the lower substrate together. FIG. 13 shows an example of the operation of the substrate bonding apparatus, in which the lift pins are lowered after the holding by the holding parts is released, thereby lowering the bonded upper and lower substrates. 13A and 13B are diagrams showing an example of the operation of the substrate bonding apparatus, in which the bonded upper and lower substrates are transferred from the lift pins to the arm. FIG. 13 is a diagram showing an example of a substrate bonding apparatus according to a second embodiment. 10 is a flowchart showing another example of the substrate bonding method according to the embodiment. 7 is a flowchart showing another example of the substrate bonding method according to the embodiment. 13A and 13B show an example of the operation of the substrate bonding apparatus, in which the upper substrate is carried into the chamber and supported by lift pins. 11A and 11B are diagrams showing an example of the operation of the substrate bonding apparatus, in which an upper substrate is placed on a supporting member. 13A to 13C are diagrams showing an example of the operation of the substrate bonding apparatus, in which an alignment operation is performed on the upper substrate. 13A to 13C are diagrams showing an example of the operation of the substrate bonding apparatus, in which the upper substrate is held by a holding portion (spacer). 13A and 13B show an example of the operation of the substrate bonding apparatus, in which the lower substrate is carried into the chamber and supported by lift pins. 13A to 13C are diagrams showing an example of the operation of the substrate bonding apparatus, in which a warp suppression bake process is performed on the lower substrate. 13A and 13B are diagrams showing an example of the operation of the substrate bonding apparatus, in which the lower substrate is supported by the lower plate. 13A to 13C are diagrams showing an example of the operation of the substrate bonding apparatus, in which an alignment operation is performed on the lower substrate. FIG. 13 shows an example of the operation of the substrate bonding apparatus, in which the upper pressing portion is lowered and the upper substrate is pushed by the pusher pin, thereby bonding the upper substrate and the lower substrate together. 13A and 13B are diagrams showing an example of the operation of the substrate bonding apparatus, in which the spacers are retracted. 13A and 13B show an example of the operation of the substrate bonding apparatus, in which the lift pins are lowered to lower the bonded upper and lower substrates. 13A and 13B are diagrams showing an example of the operation of the substrate bonding apparatus, in which the bonded upper and lower substrates are transferred from the lift pins to the arm.

The following describes an embodiment of the present invention with reference to the drawings. However, the present invention is not limited to the following description. In addition, in the drawings, some parts are omitted in order to easily explain the embodiment. Furthermore, some parts are enlarged or emphasized, and the scale is appropriately changed, and the size and shape may differ from the actual product. In each of the following figures, the directions in the figures are explained using an XYZ Cartesian coordinate system. In this XYZ Cartesian coordinate system, a plane parallel to the horizontal plane is the XY plane. In this XY plane, the direction parallel to the transport direction of the substrates S1 and S2 is the X direction, and the direction perpendicular to the X direction is the Y direction. In addition, the direction perpendicular to the XY plane is expressed as the Z direction (height direction). The X direction, Y direction, and Z direction are explained by assuming that the direction indicated by the arrow in the figure is the + direction, and the direction opposite to the direction indicated by the arrow is the - direction.

[First embodiment]
<Substrate bonding device>
A substrate bonding apparatus 100 according to the first embodiment will be described. FIG. 1 is a diagram showing an example of the substrate bonding apparatus 100 according to the first embodiment. The substrate bonding apparatus 100 bonds a substrate S1 on which an adhesive layer F is formed and a substrate S2 on which an adhesive layer F is formed by bringing the adhesive layers F into contact with each other. The adhesive layer F is not limited to being formed on both the substrate S1 and the substrate S2, and may be formed on either the substrate S1 or the substrate S2. The adhesive layer F is formed by applying and drying the substrates S1 and S2 by, for example, a coating device before being carried into the substrate bonding apparatus 100. The coating device may be provided in the substrate bonding apparatus 100.

In this embodiment, of the two substrates to be bonded, the upper substrate is referred to as substrate S1, and the lower substrate is referred to as substrate S2. Substrates S1 and S2 are, for example, glass substrates, semiconductor substrates, resin substrates, etc. In this embodiment, for example, the upper substrate S1 is a glass substrate, and the lower substrate S2 is a silicon substrate. The form in which substrates S1 and S2 are bonded is referred to as substrate S (see FIG. 18). Substrates S1 and S2 are both circular substrates that are circular in plan view (as viewed from the Z direction), but are not limited to circular substrates, and may be rectangular (square, rectangular) substrates, elliptical, oval, or other substrates in plan view.

Figure 2 is a view of the upper substrate S1 from below. Figure 3 is a cross-sectional view of the upper substrate S1. As shown in Figures 2 and 3, the upper substrate S1 has a lower surface that faces downward when it is loaded into the chamber 10, and is formed with a lower surface outer peripheral portion F1 and a lower surface inner peripheral portion F2. The lower surface inner peripheral portion F2 is formed on the inner peripheral side of the lower surface of the substrate S1. The lower surface outer peripheral portion F1 is formed on the outer peripheral side of the lower surface inner peripheral portion F2. The lower surface outer peripheral portion F1 is formed in a continuous ring-shaped area along the outer peripheral portion of the lower surface of the substrate S1 when viewed from below. When the functional area Af of the substrate S1 faces downward, the functional area Af is formed on the lower surface inner peripheral portion F2. When an element such as a semiconductor chip is mounted on the lower surface of the substrate S1 with an adhesive or the like, the area where the element is mounted forms the functional area Af. When an adhesive layer F is formed on the substrate S1, this adhesive layer F forms the functional area Af.

As shown in FIG. 1, the substrate bonding apparatus 100 includes a chamber 10, a lower plate 20, an upper holding unit 30A, a lift unit 40, a shaft unit 51, an alignment mechanism 60, and a control unit C. The control unit C controls the overall operation of each unit in the substrate bonding apparatus 100.

In the substrate bonding apparatus 100, to bond the substrates S1 and S2 together, the substrate S1 is first carried into the chamber 10 and aligned by the alignment mechanism 60, then the substrate S1 is raised by the lift unit 40 and held by the suction pad 32, which is a holding unit provided on the upper pressing unit 30A. The suction pad 32 will be described later. The substrate S2 is then carried into the chamber 10 and aligned by the alignment mechanism 60, then the substrate S2 is raised by the lift unit 40 and bonded to the substrate S1 held by the suction pad 32. When the substrate S1 is carried into the chamber 10, the substrate S1 is transported with the functional area Af facing downward (-Z direction). When the substrate S2 is carried into the chamber 10, the substrate S2 is carried into the chamber 10 with the adhesive layer F facing upward (+Z direction).

The chamber 10 is disposed on the base 15 of the substrate bonding apparatus 100. The chamber 10 is formed in a box shape having a side wall 10a rising upward from the outer periphery of the base 15 and a top plate 10b covering the upper part of the side wall 10a. The chamber 10 houses a lower plate 20, an upper holding part 30A, a lift part 40, a part of the shaft part 51, an alignment mechanism 60, and the upper holding part 30A. The chamber 10 is formed in a box shape and has an opening 11 in a part of the side wall 10a. The opening 11 is formed on the -X side surface of the chamber 10 and connects the inside and outside of the chamber 10. The opening 11 is formed to a size that allows the substrates S1 and S2 held by the transport device 90 (see FIG. 8B) and the substrate S having both of them bonded thereto to pass through.

The substrates S1 and S2 are respectively carried into the chamber 10 through the opening 11 by the arm 91 of the transport device 90. The substrate S is carried out of the chamber 10 through the opening 11. In this embodiment, the transport device 90 has two flat arms 91, and when carrying the substrate S1 into the chamber 10, the transport device 90 holds the substrate S1 by suction from the upper side thereof, and when carrying the substrate S2 into the chamber 10 and when carrying the substrate S2 out of the chamber 10, the transport device 90 holds the substrates S2 and S by suction from the lower sides thereof. Note that when carrying the substrates S2 and S, the arm 91 may be in a form in which the substrates S2 and S are placed on the upper surface side of the arm 91 and held without suction. Note that the number of arms 91 is not limited to two, and may be three or more.

The chamber 10 is equipped with a gate valve 12 that opens and closes the opening 11. The gate valve 12 is disposed on the outside of the -X side of the chamber 10, and can slide, for example, in the vertical direction (Z direction) by a drive unit (not shown). The gate valve 12 opens and closes the opening 11 by sliding. Note that even if the opening 11 is closed by the gate valve 12, the chamber 10 is in a state where it is open to the atmosphere. Also, the inside of the chamber 10 may be sealed by closing the opening 11, and the inside of the chamber 10 may be in a vacuum atmosphere. Also, a through-hole 10h through which a shaft portion 51 (described later) passes is provided on the upper surface of the chamber 10. The shaft portion 51 is inserted into the through-hole 10h. Note that the shaft portion 51 may be provided so as to be movable up and down.

The substrate bonding apparatus 100 may or may not include the chamber 10, and may be of a type not including the chamber 10 (open-to-air type). When the chamber 10 is to be a vacuum atmosphere, the chamber 10 is connected to a suction device (not shown). The chamber 10 can be suctioned (exhausted) by the suction device to create a vacuum atmosphere. The chamber 10 may also be equipped with a valve that can be opened to the outside in order to release the internal vacuum atmosphere. The chamber 10 may also be connected to a gas supply device (not shown). The chamber 10 can be conditioned to a predetermined gas atmosphere by supplying a predetermined gas from the gas supply device into the chamber 10. As the predetermined gas, for example, a gas inert to the thin films formed on the substrates S1 and S2, such as nitrogen gas, or dry air, is used.

The lower plate 20 supports the substrates S1 and S2 from below as they are loaded into the chamber 10. The lower plate 20 has a circular shape when viewed from above, but is not limited to this shape and may be, for example, a rectangular shape (square shape, rectangular shape), an elliptical shape, an oval shape, etc. The lower plate 20 is set to have an outer diameter larger than the substrates S1 and S2.

The lower plate 20 has a support plate 21, a heater (heating unit) 22, and a base plate 23. The support plate 21, heater 22, and base plate 23 are stacked in this order from the lower side (-Z side). The lower plate 20 is supported by a plurality of supports 24 provided on the lower surface side of the support plate 21. The support plate 21 and the heater 22, and the heater 22 and the base plate 23 are fixed by fastening members such as bolts. The support plate 21, the heater 22, and the base plate 23 are provided with a plurality of through holes 20a in the vertical direction through which the lift pins 41 of the lift unit 40 described later penetrate. Note that it is optional whether or not to provide the heater (heating unit) 22, and the lower plate 20 may be in a form that does not include the heater (heating unit) 22.

The support plate 21 is a plate-like body made of, for example, a material such as metal, resin, or ceramic. The heater 22 is an example of a heating unit, and is, for example, a hot plate having a heating mechanism (heat source) such as an electric heating wire inside. The heater 22 heats the substrates S1 and S2 via the base plate 23. The heater 22 may be a laminated structure in which a sheet-shaped heat source is sandwiched between the substrates. The substrates S1, S2, and the substrate S are arranged on the upper surface 23f side of the base plate 23, which is the surface on the +Z side. The base plate 23 is a plate-like body made of, for example, ceramic, but may be made of metal, resin, or the like. The upper surface 23f of the base plate 23 may be a surface that comes into contact with the substrate S2. Therefore, it is preferable that the upper surface 23f has a high flatness and a small surface roughness (or is a mirror surface).

Multiple support columns 24 are provided on the underside of the support plate 21. The multiple support columns 24 are used to support the lower plate 20 on the base 15 at the bottom of the chamber 10. Note that the number and arrangement of the support columns 24 are not limited to the above-mentioned form, and any configuration capable of supporting the lower plate 20 can be used.

As shown in FIG. 1, the upper pressing portion 30A presses the upper substrate S1 toward the substrate S2 (the lower plate 20) when the substrates S1 and S2 are attached to each other. The upper pressing portion 30A includes a base 31 provided at the bottom of the shaft portion 51 and a suction pad (holding portion) 32 provided on the underside of the base 31. The base 31 and the suction pad 32 are, for example, circular when viewed from above, but are not limited to this shape and may be, for example, rectangular (square, rectangular), elliptical, or oval. The base 31 and the suction pad 32 are set to have an outer diameter smaller than the substrates S1 and S2. The outer diameter of the base 31 and the suction pad 32 can be set arbitrarily.

The upper pressing part 30A is provided at the lower end of the shaft part 51, and its position is fixed in the vertical direction. However, if the shaft part 51 can be raised and lowered, the upper pressing part 30A may be raised and lowered together with the shaft part 51. The suction pad 32 can hold the substrate S1 by adsorbing the upper surface of the substrate S1 supported by the lift pins 41 that has risen, using the lower surface 32a as an adsorption surface. The suction pad 32 is fixed to the base part 31 by a fastening member such as a bolt. The suction pad 32 may have any configuration, and may be, for example, a vacuum suction pad or an electrostatic suction pad. The upper pressing part 30A may also be provided with a heater (heating part). Instead of the upper pressing part 30A being provided with a heater, a heater that heats the inside of the chamber 10 may also be provided.

The lift unit 40 is provided below the lower plate 20. The lift unit 40 supports the substrates S1, S2, S above the lower plate 20 and raises and lowers the substrates S1, S2, S. The lift unit 40 lowers the supported substrates S1, S2 and places them on the lower plate 20 so that the substrates S1, S2 brought into the chamber 10 can be aligned by the alignment mechanism 60. The lift unit 40 raises the supported substrate S1 so that the substrate S1 aligned by the alignment mechanism 60 can be held by the suction pad 32. The lift unit 40 raises the substrate S2 aligned by the alignment mechanism 60 so that the substrate S2 can be bonded to the substrate S1.

The lift unit 40 has multiple lift pins 41, a moving unit 42 that is connected to the lower ends of the lift pins 41 and moves up and down in the Z direction, and a lift pin drive unit 43 that moves the moving unit 42 up and down. The multiple lift pins 41 are arranged in the center of the lower plate 20. The multiple lift pins 41 support the substrates S1 and S2 by hitting the centers of the substrates S1 and S2 from below. When the functional area Af of the substrate S1 faces downward, the lift pins 41 abut against the functional area Af to support the substrate S1. Note that after the substrates S1 and S2 are placed on the lower plate 20, the upper ends of the lift pins 41 are not in contact with the substrates S1 and S2.

Figure 4 is a plan view of the lower plate 20 viewed from above. As shown in Figure 4, the lift pins 41 are arranged by penetrating each of the multiple through holes 20a provided in the lower plate 20. The heights of the upper ends of the multiple lift pins 41 are the same or approximately the same. The lift pins 41 may be formed, for example, from a non-conductive material (e.g., resin, metal, ceramics, etc.).

The moving part 42 moves up and down by driving the lift pin driving part 43. The multiple lift pins 41 move up and down simultaneously as the moving part 42 moves up and down. The lift pin driving part 43 may be, for example, an electric rotary motor, a linear motor, an air cylinder device, or a hydraulic cylinder device, and the driving force is transmitted to the moving part 42 by a transmission mechanism (not shown).

The alignment mechanism 60 positions the substrates S1 and S2 relative to the lower plate 20. As shown in FIG. 1 and FIG. 4, the alignment mechanism 60 includes a plurality of alignment drive units 61 and a plurality of alignment blocks 62. The alignment blocks 62 are used to align (position) the substrates S1 and S2 by pinching them from the radial direction. The plurality of alignment blocks 62 are arranged at intervals in the circumferential direction around the central axis AX of the lower plate 20 on the outer periphery of the base plate 23 of the lower plate 20. The plurality of alignment blocks 62 are arranged at intervals in the circumferential direction around the central axis AX, for example, five of them. Each of the plurality of alignment blocks 62 can be moved in a direction along the surface of the substrates S1 and S2 by a guide not shown. The alignment blocks 62 are preferably formed of a conductive material to prevent the substrates S1 and S2 from being charged.

The alignment drive unit 61 moves each of the multiple alignment blocks 62 in the radial direction of the base plate 23. The alignment drive unit 61 has a drive source, for example, a cylinder device or an electric motor, and a transmission mechanism that transmits the drive force generated by the drive source to each of the alignment blocks 62.

The alignment mechanism 60 drives the alignment drive unit 61 to advance the alignment block 62 in the radial direction of the base plate 23, and presses the outer edges of the substrates S1 and S2 in a direction parallel to the upper surface 23f of the base plate 23, thereby sandwiching the substrates S1 and S2. The alignment mechanism 60 drives the alignment drive unit 61 to advance and retreat the alignment block 62 in the radial direction of the base plate 23, thereby positioning the substrates S1 and S2 relative to the lower plate 20 and the upper pressing unit 30A.

The operation of the alignment mechanism 60 is controlled by the control unit C. When the alignment block 62 is used, the control unit C reads the shapes of the substrates S1 and S2 acquired by another unit (not shown), determines the alignment positions for the substrates S1 and S2, and then operates the alignment block 62. Note that the specific configuration of the alignment mechanism 60 is not limited in any way as long as it can perform the required function, and can be changed to another configuration as appropriate. For example, in FIG. 4, of the five alignment mechanisms 60 provided, the upper two alignment mechanisms 60 may be fixed, and the lower three alignment mechanisms 60 may be movable and advanceable. In this case, the three movable alignment mechanisms 60 perform alignment by driving the alignment drive unit 61 to advance the alignment block 62 and pushing the outer periphery of the substrates S1 and S2 toward the direction of the two fixed alignment mechanisms 60. In addition, in the alignment mechanism 60, the number of the alignment blocks 62 that are movable or fixed can be set as appropriate.

Figure 5 is a cross-sectional view taken along the line A-A in Figure 4. As shown in Figures 4 and 5, the lower plate 20 is provided with a support member 80. The support member 80 supports the lower surface outer periphery F1 of the substrate S1 from below when the alignment mechanism 60 positions the substrate S1. As shown in Figure 5, when receiving the substrate S1 with the functional area Af facing downward from the lift pins 41, the multiple pins 81 abut against the lower surface outer periphery F1, which is outside the functional area Af, to support the substrate S1. The support member 80 is provided on the base plate 23 of the lower plate 20.

When the lift pins 41 supporting the substrates S1 and S2 are lowered, the support members 80 abut against the lower surface outer periphery F1 of the substrate S1 to support the substrate S1. The support members 80 are provided at three or more locations spaced apart in the circumferential direction of the lower plate 20. The support members 80 are provided, for example, at four locations spaced apart in the circumferential direction of the lower plate 20. The support members 80 are, for example, pins 81 protruding from the upper surface of the lower plate 20. By abutting the pins 81 against the lower surface outer periphery F1 of the substrates S1 and S2, the substrates S1 and S2 can be stably supported with a simple configuration.

The tip of the pin 81 is hemispherical with an outer diameter that gradually decreases toward the top. The hemispherical tip of the pin 81 allows the tip of the pin 81 to come into contact with the outer periphery F1 of the lower surface of the substrate S1 by point contact. Therefore, when the substrate S1 is moved in a direction along the surface of the substrate S1 for positioning, the friction generated between the substrate S1 and the tip of the pin 81 can be kept small. In addition, since the tip of the pin 81 contacts the outer periphery F1 of the lower surface, the functional area Af is not damaged, and the occurrence of chip flying can be avoided. Note that the shape of the tip of the pin 81 is not limited to a hemispherical shape, and may be other shapes as appropriate.

As shown in FIG. 4, each of the alignment blocks 62 is positioned offset in the circumferential direction of the lower plate 20 relative to the pins 81. With this configuration, when the alignment mechanism 60 positions the substrates S1 and S2, interference between the alignment blocks 62 and the pins 81 can be reduced when the alignment blocks 62 move forward and backward along the surfaces of the substrates S1 and S2 to sandwich the substrates S1 and S2.

<Substrate bonding method>
Next, a substrate bonding method according to this embodiment will be described. FIG. 6 is a flowchart showing an example of the substrate bonding method according to this embodiment. FIG. 7 is a flowchart showing an example of the substrate bonding method according to this embodiment, following FIG. 6. This substrate bonding method is executed, for example, by instructions from the control unit C. FIG. 8 to FIG. 18 are process diagrams showing an example of the operation of the substrate bonding apparatus 100. Note that in these process diagrams, the description is simplified so that the operation of each part can be easily understood. Below, a description will be given along the flowcharts of FIG. 6 and FIG. 7.

First, the gate valve 12 of the chamber 10 is opened and a substrate is loaded (step S01). As shown in FIG. 8, the control unit C drives a drive unit (not shown) to raise the gate valve 12 and open the opening 11. Next, the substrate S1 (upper substrate) is loaded into the chamber 10. At this time, the control unit C raises the lift pins 41 to the transfer height of the substrate S1.

The arm 91 of the transport device 90, holding the substrate S1 on its underside, enters the chamber 10 through the opening 11 and positions the substrate S1 above the lift pins 41. The arm 91 holds the substrate S1 by suction using a suction pad (not shown) or the like provided on its underside. The control unit C then lowers the arm 91 and transfers the substrate S1 from the arm 91 to the lift pins 41 (step S02). The lift pins 41 abut against the center of the inner periphery F2 of the underside of the substrate S1 from below. The arm 91 then exits the chamber 10. Note that if the substrate S1 has an adhesive layer F, the adhesive layer F is on the lower side when the substrate S1 is carried into the chamber 10.

Next, as shown in FIG. 9, the control unit C lowers the lift pins 41 supporting the substrate S1, and places the substrate S1 on the multiple support members 80 (pins 81) of the lower plate 20 (step S03). At this time, the lift pins 41 are lowered to a position lower than the multiple support members 80 (i.e., the lower surface of the substrate S1), and the substrate S1 is supported by the multiple support members 80. With this configuration, the substrate S1 is not in contact with the lift pins 41, and is supported only by the multiple support members 80 that contact the lower surface outer periphery F1 from below. The substrate S1 may also be heated by the heater 22.

Next, an alignment operation is performed on the substrate S1 (step S04). As shown in FIG. 10, the control unit C drives the alignment drive unit 61 to advance each alignment block 62 radially inward, and positions the substrate S1 by sandwiching the substrate between the alignment blocks 62. At this time, the substrate S1 is supported at the lower surface outer periphery F1 by the multiple support members 80. Therefore, when the substrate S1 is positioned by the multiple alignment blocks 62, rubbing occurs between the multiple support members 80 and the lower surface outer periphery F1 of the substrate S1 when the substrate S1 is moved within a plane along the lower surface of the substrate S1. After the alignment operation, the control unit C retracts each alignment block 62 radially outward, and then raises the lift pins 41 to position the substrate S1 above the spacers 72.

Subsequently, the substrate S1 is held by the suction pad 32 (step S05). As shown in FIG. 11, the control unit C raises the lift pin 41, receives the substrate S1 from the support member 80, raises the substrate S1, and abuts the substrate S1 against the suction surface 32a of the suction pad 32 of the upper pressing unit 30A. When the substrate S1 abuts, the control unit C drives the suction pad 32 to a state in which it can be adsorbed in advance. As a result, the substrate S1 is held by the suction pad 32. The lift pin 41 is then lowered, so that the lift pin 41 is separated from the substrate S1.

Substrate S2 (lower substrate) is then loaded into chamber 10 (step S06). As shown in FIG. 12, control unit C lowers lift pins 41 to the transfer height of substrate S2. Substrate S2 is then loaded into chamber 10 by arm 91 and positioned above lift pins 41. Arm 91 holds substrate S2 by suction on its underside. Control unit C then lowers arm 91 and transfers substrate S2 from arm 91 to lift pins 41. Arm 91 then exits chamber 10. Note that substrate S2 is loaded into chamber 10 with adhesive layer F facing up.

Then, the gate valve 12 is closed and a warp suppression bake process is performed to suppress warpage of the substrate S2 (step S07). As shown in FIG. 13, after the gate valve 12 is closed, the substrate S2 is heated by, for example, the heater 22 to perform the warp suppression bake process. By baking the substrate S2, the shape of the substrate S2 can be stabilized and warpage of the substrate S2 can be suppressed. This warp suppression bake process is performed while the temperature in the chamber 10 is maintained at, for example, 150°C to 250°C. Note that, even if the gate valve 12 is closed, the above steps S02 to S07 are performed with the chamber 10 open to the atmosphere. However, for example, steps S03, S04, S07, etc. may be performed in a vacuum atmosphere in the chamber 10.

Next, as shown in FIG. 14, the lift pins 41 are lowered to place the substrate S2 on the lower plate 20. The lift pins 41 are lowered to a position lower than the multiple support members 80, so that the substrate S2 is supported only by the multiple support members 80. With this configuration, the substrate S2 is not in contact with the lift pins 41, and is supported by the multiple support members 80 that contact the lower surface outer periphery F1 from below. Thereafter, the substrate S2 is heated by the heater 22, and the warp suppression bake process may be performed in an open-to-air state, or the warp suppression bake process may be performed in a vacuum atmosphere inside the chamber 10. This warp suppression bake process is performed by setting the temperature of the heater 22 to, for example, 150°C to 250°C.

Next, an alignment operation is performed on the substrate S2 (step S08). As shown in FIG. 15, the control unit C drives the alignment drive unit 61 to advance each alignment block 62 radially inward, and positions the substrate S2 by sandwiching the substrate S2 between the alignment blocks 62. At this time, the substrate S2 is supported at the lower surface outer periphery F1 by the support members 80. Therefore, when the substrate S2 is moved in a plane along the lower surface of the substrate S2 to position the substrate S2 with the alignment blocks 62, friction occurs only between the support members 80 and the lower surface outer periphery F1 of the substrate S1. The alignment operation in step S08 is similar to the alignment operation in step S04. Therefore, the substrates S1 and S2 are positioned at approximately the same position in a plan view.

Next, as shown in FIG. 16, the control unit C raises the lift pins 41 to raise the substrate S2, thereby bonding the substrates S1 and S2 together (step S09). At this time, the suction pads 32 of the upper pressing unit 30A press the upper surface of the substrate S1, and the substrate S2 is raised by the lift pins 41 and overlapped with the substrate S1, thereby bonding the substrates S1 and S2 together. In other words, the suction pads 32 function as a holding unit that holds the substrate S1, and also have the function of abutting against the upper surface of the substrate S1 to press the upper surface of the substrate S1. In step S09, the adhesive layer F of the substrate S1 and the adhesive layer F of the substrate S2 come into contact with each other, thereby bonding the substrates S1 and S2 together. The force with which the substrates S1 and S2 are bonded together is controlled by the force with which the lift pins 41 rise. Instead of raising the lift pins 41, the upper holding portion 30A that holds the substrate S1 may be lowered, or the lift pins 41 may be raised and the upper holding portion 30A may be lowered.

Next, the suction pad 32 is released from the suction of the substrate S1 (step S10). After bonding the substrates S1 and S2, the control unit C releases the suction of the substrate S1 by the suction pad 32. Next, as shown in FIG. 17, the lift pin 41 is lowered to position the substrate S after bonding at a height for removal. This process causes the substrate S to leave both the lower plate 20 and the upper pressing unit 30A. Next, the gate valve 12 is opened to remove the substrate S from the chamber 10 (step S11). As shown in FIG. 18, after the gate valve 12 is raised to open the opening 11, the arm 91 of the transport device 90 is inserted into the chamber 10 from the opening 11, and the arm 91 is positioned below the substrate S supported by the lift pin 41. Then, the control unit C raises the arm 91 and holds the substrate S on the upper surface of the arm 91 by suction, thereby transferring the substrate S from the lift pin 41 to the arm 91. The arm 91 may be configured not to hold the substrate S by suction, but to hold the substrate S by placing it on the upper surface of the arm 91. The arm 91 then leaves the chamber 10, and the substrate S is transported to the outside of the chamber 10. The control unit C then closes the gate valve 12, ending the series of processes.

[Second embodiment]
<Substrate bonding device>
A substrate bonding apparatus 200 according to the second embodiment will be described. FIG. 19 is a diagram showing an example of the substrate bonding apparatus 200 according to the second embodiment. In each of the figures following FIG. 19, the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted or simplified. The substrate bonding apparatus 200 bonds a substrate S1 on which an adhesive layer F is formed and a substrate S2 on which an adhesive layer F is formed by abutting the adhesive layers F of the substrates. As shown in FIG. 19, the substrate bonding apparatus 200 includes a chamber 10, a lower plate 20, an upper pressing unit 30B, a lift unit 40, a lifting mechanism 50, an alignment mechanism 60, a spacer mechanism 70, and a control unit C. The control unit C controls the operation of each unit in the substrate bonding apparatus 200.

To bond substrates S1 and S2 together in the substrate bonding apparatus 200, first substrate S1 is carried into the chamber 10 and aligned by the alignment mechanism 60, then substrate S1 is raised by the lift unit 40 and held by the spacer mechanism 70. Substrate S2 is then carried into the chamber 10 and aligned by the alignment mechanism 60, then substrate S2 is raised by the lift unit 40 and bonded to substrate S1 held by the spacer mechanism 70. The chamber 10 contains the lower plate 20, the upper pressing unit 30B, the lift unit 40, part of the lifting mechanism 50, the alignment mechanism 60, and the spacer mechanism 70.

The shaft 51 is inserted into the through-hole 10h on the top surface of the chamber 10 in a state in which it can be raised and lowered, and the chamber 10 is kept sealed by a sealing member (not shown). The chamber 10 can be sealed by closing the opening 11 with the gate valve 12. The chamber 10 can be made into a vacuum atmosphere by sucking (exhausting) the chamber 10 with a suction device (not shown). Furthermore, the chamber 10 may be equipped with a valve that can be opened to the outside in order to release the vacuum atmosphere inside. The chamber 10 may also be connected to a gas supply device (not shown). The substrate bonding apparatus 200 may be optionally equipped with the chamber 10 or may not be equipped with the chamber 10 (open to the atmosphere).

The lower plate 20, support plate 21, heater 22, base plate 23, and support column 24 are the same as those in the first embodiment described above, so their explanations are omitted.

As shown in FIG. 19, the upper pressing portion 30B presses the upper substrate S1 toward the substrate S2 (lower plate 20) when the substrates S1 and S2 are attached to each other. The upper pressing portion 30A includes a base 31 and a plurality of pusher pins 33 provided on the lower surface side of the base 31. The plurality of pusher pins 33 are provided so as to extend downward from the base 31 at intervals. Each of the plurality of pusher pins 33 is provided at its lower end with a pin 33a that can be pushed upward by an elastic member (not shown). The upper pressing portion 30B is provided at the lower end of the shaft portion 51, and its position is fixed in the vertical direction. However, if the shaft portion 51 is capable of rising and falling, the upper pressing portion 30B may be configured to rise and fall together with the shaft portion 51.

The lift unit 40 lowers the supported substrates S1 and S2 and places them on the lower plate 20 so that the substrates S1 and S2 brought into the chamber 10 can be aligned by the alignment mechanism 60. The lift unit 40 raises the supported substrate S1 so that the substrate S1 aligned by the alignment mechanism 60 can be held by the spacer 72. The lift unit 40 raises the substrate S2 aligned by the alignment mechanism 60 so that the substrate S2 can be bonded to the substrate S1. The lift pins 41, the moving unit 42, the lift pin driving unit 43, and the alignment mechanism 60 are the same as those in the first embodiment described above, and therefore will not be described here.

The lifting mechanism 50 lowers the upper pressing portion 30B and presses the substrate S1 towards the substrate S2 side (the lower plate 20 side) when bonding the substrates S1 and S2 together. The lifting mechanism 50 includes the shaft portion 51 described above and a drive portion 52 that drives the shaft portion 51. The shaft portion 51 is disposed in the center of the base portion 31 when viewed from above. The drive portion 52 raises and lowers the shaft portion 51. The drive portion 52 may be, for example, an air cylinder device, a hydraulic cylinder device, or a ball screw mechanism using an electric rotary motor.

The drive unit 52 is controlled by the control unit C. The load applied to the shaft portion 51 by the drive unit 52 and the drive timing for applying the load are controlled by the control unit C based on a preset program or the like. In addition, some or all of the operation of the drive unit 52 may be performed by an operator. By raising and lowering the shaft portion 51 by the drive unit 52, the upper pressing portion 30B rises and falls integrally with the shaft portion 51.

As shown in FIG. 19, the spacer mechanism 70 receives and supports the previously loaded substrate S1 from the lift pins 41. The spacer mechanism 70 includes a plurality of spacer driving units 71 and a plurality of spacers (holding units) 72. The spacer driving units 71 are provided in the chamber 10. The spacer driving units 71 move the spacers 72 in the X direction or Y direction. The spacer driving units 71 include, for example, a driving source such as a cylinder device or an electric motor, and a transmission mechanism that transmits the driving force generated by the driving source to the spacers 72.

The spacer 72 can be moved in a radial direction around the central axis AX in a plane perpendicular to the Z direction by a guide (not shown). The spacer 72 is preferably made of a conductive material to prevent the substrates S1 and S2 from becoming charged. The spacer mechanism 70 drives the spacer drive unit 71 to advance the spacer 72 and position it below the outer periphery of the substrate S1, thereby holding the substrate S1 placed on the lift pins 41. The operation of the spacer mechanism 70 is controlled by the control unit C.

<Substrate bonding method>
Next, the substrate bonding method according to the present embodiment will be described. FIG. 20 is a flowchart showing another example of the substrate bonding method according to the present embodiment. FIG. 21 is a flowchart showing another example of the substrate bonding method according to the present embodiment, following FIG. 20. This substrate bonding method is executed, for example, by instructions from the control unit C. FIG. 22 to FIG. 33 are process diagrams showing an example of the operation of the substrate bonding apparatus 200. In these process diagrams, the description is simplified so that the movement of each part can be easily understood. Below, the description will be given along the flowcharts of FIG. 20 and FIG. 21.

First, the gate valve 12 of the chamber 10 is opened and the substrate is loaded (step S101). As shown in FIG. 22, the control unit C raises the gate valve 12 and opens the opening 11. Next, the arm 91 of the transport device 90 loads the substrate S1 from the opening 11 into the chamber 10 and passes it to the lift pins 41 (step S102). Next, as shown in FIG. 23, the control unit C lowers the lift pins 41 and places the substrate S1 on the multiple support members 80 (pins 81) of the lower plate 20 (step S103). The substrate S1 may also be heated by the heater 22.

Next, as shown in FIG. 24, the control unit C performs an alignment operation on the substrate S1 (step S104). Step S104 is the same as step S04 shown in FIG. 6, so the description will be omitted. After the alignment operation, the control unit C retracts each alignment block 62 radially outward, and then raises the lift pins 41 to position the substrate S1 above the spacers 72. Next, the substrate S1 is held by the spacers 72 (step S105). As shown in FIG. 25, the control unit C raises the lift pins 41, receives the substrate S1 from the support member 80, and after raising the substrate S1, drives the spacer drive unit 71 to advance the spacer 72 and position the spacer 72 on the lower surface side of the substrate S1. Then, the lift pins 41 are lowered, so that the substrate S1 is held by the spacers 72.

Subsequently, the substrate S2 is loaded into the chamber 10 (step S106). As shown in FIG. 26, the lift pins 41 are lowered to the transfer height of the substrate S2, and then the arm 91 transfers the substrate S2 from the arm 91 to the lift pins 41. Next, the gate valve 12 is closed, and a warpage suppression bake process is performed to suppress warpage of the substrate S2 (step S107). As shown in FIG. 27, after the gate valve 12 is closed, the substrate S2 is heated by the heater 22 while the chamber 10 is evacuated by a suction device (not shown), for example, to perform the warpage suppression bake process. Note that the warpage suppression bake process can be performed with the gate valve 12 open (i.e., open to the atmosphere).

Then, the chamber 10 is made into a vacuum atmosphere (step S108). The chamber 10 is evacuated by a suction device (not shown), so that the chamber 10 is made into a vacuum atmosphere. Then, as shown in FIG. 28, the lift pins 41 are lowered to place the substrate S2 on the lower plate 20. Then, the substrate S2 is heated by the heater 22, and the warp suppression bake process may be performed in a vacuum atmosphere, or may be performed in an open-to-air state. Next, the control unit C performs an alignment operation on the substrate S2 as shown in FIG. 29 (step S109). Step S109 is the same as step S08 shown in FIG. 6, and therefore will not be described. The alignment operation in step S109 is the same as the alignment operation in step S104.

Then, the control unit C raises the lift pins 41 to raise the substrate S2 and bring the substrate S2 close to the lower surface of the spacer 72 (step S110). The upper surface of the substrate S2 may be separated from the lower surface of the spacer 72 or may be in contact with the lower surface of the spacer 72. In this state, the spacer 72 is sandwiched between the substrates S1 and S2. The substrates S1 and S2 may be in contact in the area where the spacer 72 is not present. Next, as shown in FIG. 30, the control unit C drives the drive unit 52 to lower the upper pressing unit 30 together with the shaft unit 51, and the pusher pin 33 of the upper pressing unit 30 presses the substrate S1 against the substrate S2, overlapping the substrates S1 and S2 (step S111).

In step S111, the pin 33a provided at the lower end of the pusher pin 33 is pushed into the pusher pin 33 against the elastic force of the elastic member. With this configuration, the multiple pusher pins 33 can press the substrate S1 against the substrate S2 in a well-balanced manner.

Next, the control unit C retreats the spacer 72 to its original position as shown in FIG. 31 (step S112). As the spacer 72 retreats, the portion that sandwiched the spacer 72 disappears, and the substrate S1 is pushed by the pusher pin 33, so that the substrates S1 and S2 are bonded together. Next, as shown in FIG. 32, the lift pin 41 is lowered to position the substrate S after bonding at a height for removal. This process separates the substrate S from both the lower plate 20 and the upper pressing unit 30B. After that, a valve (not shown) is opened to expose the chamber 10 to the atmosphere, or a specified gas is supplied into the chamber 10 to purge the chamber 10 (step S113). For example, nitrogen gas, dry air, etc., are used as the specified gas.

Next, as shown in FIG. 33, the gate valve 12 is opened to unload the substrate S from the chamber 10 (step S114). After the opening 11 is opened, the substrate S is unloaded by the arm 91 of the transport device 90. Thereafter, the control unit C closes the gate valve 12 to end the series of processes.

As described above, in the substrate bonding apparatus 100, 200 according to the embodiment, the support member 80 abuts against the outer peripheral portion F1 of the lower surface of the substrates S1, S2 to support the substrate S1, so that when the substrate S1 is positioned, the support member 80 is prevented from rubbing against the inner peripheral portion F2 of the lower surface of the substrate S1. Therefore, with the substrate bonding apparatus 100, 200 according to the embodiment, damage to the functional surface of the substrate S1, generation of foreign matter, chip flying, etc., during alignment can be suppressed, and the substrates S1, S2 can be bonded together with good quality.

Although the above describes the embodiments and modifications, the present invention is not limited to the above description, and various modifications are possible within the scope of the gist of the present invention. In the above embodiment, an example is given in which two substrates S1 and S2 are bonded together, but the present invention is not limited to this. For example, the present invention may be configured such that another substrate is bonded to the substrate S to which substrates S1 and S2 are bonded.

In the above embodiment, when the substrate S2 is positioned by the alignment block 62, the substrate S2 is supported by a plurality of support members 80. However, in the case of the substrate S2, the substrate S2 may be positioned by being sandwiched between the alignment blocks 62 while still being supported by the lift pins 41.

10: Chamber 20: Lower plate 23f: Upper surface 30A, 30B: Upper pressing portion 32: Suction pad (holding portion)
33: Pusher pin 41: Lift pin 50: Lifting mechanism 60: Alignment mechanism 62: Alignment block 72: Spacer (holding portion)
80: Support member 81: Pin 100, 200: Substrate bonding apparatus Af: Functional area F1: Lower surface outer periphery S: Substrate

Claims (9)

a substrate bonding apparatus including a lower plate, lift pins provided on the lower plate for supporting and raising and lowering a substrate carried in, a holding section for receiving and holding a previously carried in substrate from the lift pins, and an upper pressing section disposed above the lower plate and capable of contacting an upper surface side of the substrate held by the holding section, the apparatus raising the subsequently carried in substrate by the lift pins to bond the previously carried in substrate to the subsequently carried in substrate,
a support member provided on the lower plate, the support member contacting an outer periphery of a lower surface of the substrate that has been previously loaded and supporting the substrate when the lift pins are lowered;
an alignment mechanism that positions the substrate by sandwiching the substrate supported by the support member in a direction along a surface of the substrate, and positions the substrate by sandwiching the substrate that is carried in later among the substrates to be bonded in a direction along the surface of the substrate while being supported by the lift pins;
A substrate bonding apparatus comprising: The substrate bonding apparatus according to claim 1, wherein the support members are pins provided at three or more locations spaced apart in the circumferential direction of the lower plate and protruding from the upper surface of the lower plate. the alignment mechanism includes a plurality of alignment blocks capable of moving forward and backward in a direction along a surface of the substrate to sandwich the substrate;
The substrate bonding apparatus according to claim 2 , wherein each of the plurality of alignment blocks is arranged in a circumferentially offset state with respect to the pins. the lift pins support the substrate by contacting the functional area when the functional area of the substrate faces downward;
The substrate bonding apparatus according to claim 1 , wherein the support member supports the substrate by contacting an outer periphery of the lower surface of the substrate received from the lift pins, the outer periphery being outside the functional area. The substrate bonding apparatus according to any one of claims 1 to 4, wherein the upper pressing part is capable of being raised and lowered, and is provided with a lifting mechanism for raising and lowering the upper pressing part. The substrate bonding apparatus according to any one of claims 1 to 5, wherein one or both of the lower plate and the upper pressing part are provided with a heating part for heating the substrate. The substrate bonding apparatus according to any one of claims 1 to 6, comprising a chamber that houses the lower plate and the upper pressing part. The substrate bonding device according to claim 2, wherein the tip of the pin is hemispherical. A method for bonding two substrates, comprising the steps of:
supporting the loaded substrate with lift pins;
receiving the previously loaded substrate from the lift pins and holding the substrate with a holding portion;
a support member that is in contact with an outer periphery of a lower surface of the substrate and supports the upper substrate of the two substrates to be bonded together by the support member;
positioning the substrate by clamping the substrate supported by the support member in a direction along a surface of the substrate;
a lower substrate of the two substrates to be bonded is subsequently brought in, and the substrate is positioned by being sandwiched in a direction along the surface of the substrate while being supported by the lift pins.

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