Bonding device

Abstract

A bonding device for bonding a plurality of dies to a target substrate, the bonding device comprising a substrate holding unit for holding the target substrate, and a head unit for bonding the dies to the target substrate held by the substrate holding unit, the head unit comprising: an electrically conductive bond head for holding the dies; an insulator that holds the bond head; and a ground connection body that connects the bond head to ground potential.

Description

Bonding equipment

[0001] The present disclosure relates to an anastomosis device.

[0002] Patent Document 1 discloses a chip-on-wafer bonding method for mounting chips on a wafer, in which a surface activation process and a hydrophilization process are performed on the chips, a surface activation process and a hydrophilization process are performed on the substrate, and then multiple chips are bonded to the substrate.

[0003] Patent No. 6337400

[0004] The disclosed technology prevents a bond head from becoming electrically charged when a die held by the bond head is bonded to a target substrate in a die-ion process manufacturing process.

[0005] One aspect of the present disclosure is a bonding device that bonds multiple dies to a target substrate, comprising: a substrate holding portion that holds the target substrate; and a head portion that bonds the dies to the target substrate held by the substrate holding portion, wherein the head portion comprises: a conductive bond head that holds the dies; an insulator that holds the bond head; and a ground connector that connects the bond head to a ground potential.

[0006] According to the present disclosure, when a die held by a bond head is bonded to a target substrate in a die-ion process manufacturing process, the bond head can be prevented from becoming charged.

[0007] FIG. 1 is a plan view showing an outline of the configuration of a wafer on which a plurality of dies are mounted. FIG. 2 is a cross-sectional view showing an outline of the configuration of a first carrier that holds a first die. FIG. 3 is a cross-sectional view showing an outline of the configuration of a second carrier that holds a second die. FIG. 4 is a plan view showing an outline of the configuration of a second carrier that holds a second die. FIG. 5 is a plan view showing an outline of the configuration of a processing system. FIG. 6 is a flow chart showing main steps of a die-on wafer manufacturing process. FIG. 7 is an explanatory diagram schematically showing some steps of the die-on wafer manufacturing process. FIG. 8 is a perspective view showing an outline of the configuration of a first bonding apparatus according to the present embodiment. FIG. 9 is a side view and a plan view showing an outline of the configuration of a head unit according to the present embodiment. FIG. 10 is a side view showing an outline of the configuration of a head unit according to another embodiment. FIG. 11 is a perspective view showing an outline of the configuration of a first bonding apparatus according to another embodiment.

[0008] In recent years, in the manufacturing process of semiconductor devices, in response to demands for even higher performance and higher density of devices, a chip-on-wafer (CoW) manufacturing process has been studied as one method of three-dimensional packaging technology. Chip-on-wafer manufacturing is carried out by a method disclosed in Patent Document 1, for example.

[0009] In the chip-on-wafer manufacturing process (hereinafter referred to as the "die-on-wafer manufacturing process"), as disclosed in Patent Document 1, a surface activation process and a hydrophilization process are performed on a semiconductor chip (hereinafter referred to as the "die"), and a surface activation process and a hydrophilization process are also performed on a semiconductor substrate (hereinafter referred to as the "wafer"), and then multiple dies are bonded to the wafer.

[0010] Bonding of multiple dies to a wafer is performed using a bonding device. For example, in the bonding device, a pickup unit is used to first pick up the die from a carrier that holds multiple dies. Next, a head unit receives the die from the pickup unit, and the die held by the head unit is positioned opposite the wafer held by the wafer holder. The head unit is then lowered, and the die is placed on the wafer and bonded.

[0011] For example, the head unit includes a conductive bond head configured to hold a die and an insulating plate that holds the top surface of the bond head. In other words, the bond head is electrically floating. In this case, when the bond head repeatedly receives a die from the pickup unit and then transfers the die to the wafer, the bond head becomes charged. If the bond head becomes charged in this way, when the bond head receives a die from the pickup unit, it discharges electricity and current flows from the bond head to the die. This can damage the circuit (device) contained in the die. Therefore, there is room for improvement when mounting multiple dies on a wafer.

[0012] The technology disclosed herein prevents a bond head from becoming charged when bonding a die held by the bond head to a target substrate in a die-ion process. A processing system and a processing method having a bonding apparatus according to the present embodiment will be described below with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals, and redundant description will be omitted.

[0013] In this embodiment, as shown in Fig. 1, multiple types of dies D1 and D2 are mounted on a wafer W as a target substrate. Specifically, multiple first dies D1 held on a first carrier C1 as shown in Figs. 2 and 3 and multiple second dies D2 held on a second carrier C2 as shown in Figs. 4 and 5 are bonded to the wafer W as a mounting target.

[0014] 1, the wafer W on which the first die D1 and the second die D2 are mounted is a semiconductor wafer such as a silicon substrate or a glass substrate used in the manufacturing process of semiconductor devices. For example, the diameter of the wafer W is 300 mm and the thickness is approximately 800 μm. The surface of the wafer W on which the first die D1 and the second die D2 are mounted is referred to as the front surface Wa, and the surface opposite to the front surface Wa is referred to as the back surface Wb.

[0015] The number and arrangement of the first die D1 and the second die D2 to be mounted on the front surface Wa of the wafer W are set to a desired pattern. A device layer (not shown) may be formed on the front surface Wa. This device layer is formed to correspond to a device layer E of the first die D1, which will be described later.

[0016] 2 and 3, the first carrier C1 holds a plurality of first dies D1. The first die D1 has a configuration in which, for example, a silicon layer S1 and a device layer E are stacked. A circuit is formed in the device layer E. As will be described later, when the first die D1 is bonded to the wafer W, high bonding accuracy is required for the first die D1, i.e., the first die D1 is a high-precision die. Note that the surface of the first die D1 on which the device layer E is formed is referred to as the front surface D1a, and the surface opposite to the front surface D1a is referred to as the back surface D1b.

[0017] 4 and 5, the second carrier C2 holds a plurality of second dies D2. Each second die D2 has a structure in which, for example, a silicon layer S2 and an oxide film F are stacked. No devices such as circuits are formed on the oxide film F. As will be described later, when the second die D2 is bonded to the wafer W, low bonding accuracy is required for the second die D2; that is, the second die D2 is a low-precision die. The surface of the second die D2 on which the oxide film F is formed is referred to as the front surface D2a, and the surface opposite to the front surface D2a is referred to as the back surface D2b.

[0018] As described above, the first die D1 and the second die D2 are different types of dies. The first die D1 has a circuit formed thereon, whereas the second die D2 does not. Therefore, the joining accuracy required for the first die D1 is relatively high, while the joining accuracy required for the second die D2 is relatively low. In addition, the shapes (size and thickness) of the first die D1 and the second die D2 are also different. Therefore, the number of first dies D1 held by the first carrier C1 and the number of second dies D1 held by the second carrier C2 are also different.

[0019] The first carrier C1 and the second carrier C2 have the same configuration. First, the configuration of the first carrier C1 will be described.

[0020] 2 and 3, the first carrier C1 has an upper surface that serves as an adsorption surface for holding a plurality of first dies D1 by electrostatic and vacuum adsorption. The first carrier C1 adsorbs and holds the silicon layer S1 on the back surface D1b side of the first die D1. The first carrier C1 has a structure in which a main body M1 and an insulating layer N1 are stacked.

[0021] The main body M1 has approximately the same diameter and thickness as the wafer W on which the first die D1 is mounted, e.g., a diameter of 300 mm and a thickness of approximately 800 μm. The main body M1 is made of any conductive material, such as silicon, aluminum, an aluminum alloy, stainless steel, alumina, zirconia, SiC, or titanium. In other words, a silicon substrate may be used as the main body M1. The main body M1 may have approximately the same diameter as the wafer W on which the first die D1 is mounted, but may have a different thickness (e.g., 500 μm to 1000 μm) from the wafer.

[0022] The main body M1 has a plurality of through holes H1 formed therethrough in the thickness direction. The through holes H1 can be formed at any position on the suction surface of the first carrier C1. For example, the through holes H1 may be formed one for each of the first dies D1 held by the first carrier C1, in other words, the same number as the number of first dies D1 held by the first carrier C1. Alternatively, for example, the through holes H1 may be formed in a number corresponding to each of the first dies D1 held by the first carrier C1, in other words, a number greater than the number of first dies D1 held by the first carrier C1.

[0023] Although the number, size, spacing, and arrangement of the through holes H1 are not particularly limited, it is desirable to determine the number, size, and spacing so as to ensure the strength (rigidity) of the first carrier C1 so that deformation such as bending does not occur. For example, the diameter of the through holes H1 is 0.5 mm to 5.0 mm, and the spacing (the center-to-center distance between adjacent through holes H1) is 0.5 mm to 5.0 mm.

[0024] The insulating layer N1 is formed on the surface of the main body M1 and constitutes the adsorption surface of the first die D1 on the first carrier C1. The insulating layer N1 has no through-holes and covers the surface of the main body M1. The insulating layer N1 has a thickness of, for example, several tens of μm, which is sufficient to hold the first die D1 on the first carrier C1 by electrostatic adsorption.

[0025] The insulating layer N1 is made of a flexible and insulating material, such as polyimide or EVA (ethylene-vinyl acetate copolymer). In this embodiment, "the insulating layer N1 is flexible" means that the insulating layer N1 on the main body M1 has an elastic modulus of 2 GPa or less, preferably 0.5 GPa or less. In this embodiment, "the insulating layer N1 has insulating properties" means that the insulating layer N1 on the main body M1 has a breakdown voltage of 30 kV or more, preferably 40 kV or more.

[0026] 4 and 5, the second carrier C2 has the same configuration as the first carrier C1, as described above, and is configured by stacking a main body M2 and an insulating layer N2. The configurations of the main body M2 and the insulating layer N2 are the same as those of the main body M1 and the insulating layer N1, respectively. The main body M2 has a plurality of through holes H2 formed therethrough in the thickness direction. Because the second die D2 held by the second carrier C2 is a different type from the first die D1, the number, size, spacing, and arrangement of the through holes H2 may be different from those of the through holes H1 of the first carrier C1.

[0027] The first carrier C1 in this embodiment is configured as described above, and attracts and holds the first die D1 on its attracting surface by generating an electrostatic (Coulomb) force between the first carrier C1 and the first die D1. Similarly, the second carrier C2 attracts and holds the second die D2 on its attracting surface by generating an electrostatic (Coulomb) force between the second carrier C2 and the second die D2.

[0028] In addition, in this embodiment, the first carrier C1 has an insulating layer N1 made of a flexible material with a small elastic modulus. After the first die D1 is placed on the first carrier C1, a gap is formed between the first die D1 and the insulating layer N1 before the first die D1 is electrostatically attracted and held. Due to the flexibility of the insulating layer N1, when the first die D1 is electrostatically attracted to the insulating layer N1, air escapes between the first die D1 and the insulating layer N1, creating a pseudo-vacuum between the first die D1 and the insulating layer N1. As a result, in addition to the electrostatic attraction between the first carrier C1 and the first die D1, a vacuum attraction force is generated due to the pseudo-vacuum state, creating a strong holding state using both the electrostatic attraction and the vacuum attraction. Similarly, the second carrier C2 attracts and holds the second die D2 using both the electrostatic attraction and the vacuum attraction.

[0029] The method of holding the dies D1 and D2 by the carriers C1 and C2 is not limited to this embodiment. For example, the dies D1 and D2 may be pressed against the carriers C1 and C2 to be crimped. In this case, pressing the dies D1 and D2 against the carriers C1 and C2 removes air from between the dies D1 and D2 and the insulating layers N1 and N2, generating a vacuum suction force between the dies D1 and D2 and the insulating layers N1 and N2, thereby adsorbing and holding the dies D1 and D2 to the carriers C1 and C2. In this case, the material of the main bodies M1 and M2 of the carriers C1 and C2 does not need to be conductive and can be any material. Furthermore, the material of the insulating layers N1 and N2 does not need to be insulating and can be any material.

[0030] Alternatively, for example, adhesive sheets may be used for the insulating layers N1 and N2 of the carriers C1 and C2. In this case, adhesive force is generated between the dies D1 and D2 and the insulating layers N1 and N2, thereby holding the dies D1 and D2 on the carriers C1 and C2. Alternatively, thermal release sheets may be used for the insulating layers N1 and N2. The thermal release sheet is a sheet that has adhesive force at room temperature but is released when heated. As will be described later, when the dies D1 and D2 are bonded to the wafer W, the dies D1 and D2 are released from the carriers C1 and C2. At this time, heating the insulating layers N1 and N2 can make it easier to release the dies D1 and D2.

[0031] Next, a processing system 1 according to this embodiment will be described. In the processing system 1, a plurality of first dies D1 held in a first carrier C1 and a plurality of second dies D2 held in a second carrier C2 are mounted on a wafer W. FIG. 6 is a plan view showing an outline of the configuration of the processing system 1.

[0032] 6, the processing system 1 has a configuration in which a load / unload station 10 and a processing station 20 are integrally connected. In the load / unload station 10, for example, FOUPs Fw, Fc1, and Fc2, each capable of accommodating a plurality of wafers W, a plurality of first carriers C1, and a plurality of second carriers C2, are loaded and unloaded between the load / unload station 10 and the outside. The processing station 20 has, for example, three processing blocks 21 to 23, and is equipped with various processing devices for implementing a series of processes described below.

[0033] The loading / unloading station 10 is provided with a FOUP mounting table 30. In the illustrated example, a plurality of FOUPs, for example, two FOUPs Fw, one FOUP Fc1, and one FOUP Fc2, are placed on the FOUP mounting table 30, lined up in the Y-axis direction. Note that the number and arrangement of the FOUPs Fw, Fc1, and Fc2 placed on the FOUP mounting table 30 are not limited to those in this embodiment and can be determined arbitrarily.

[0034] A transfer device 40 is provided adjacent to the FOUP mounting table 30 on the positive side of the X-axis. The transfer device 40 is configured to be movable on a transfer path 41 extending in the Y-axis direction. The transfer device 40 also has, for example, two transfer arms 42, 42 that hold and transfer wafers W, first carriers C1, and second carriers C2. Each transfer arm 42 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. Note that the configuration of the transfer arms 42 is not limited to this embodiment and may have any configuration. The transfer device 40 is configured to transfer wafers W, first carriers C1, and second carriers C2 to and from the FOUPs Fw, Fc1, and Fc2 on the FOUP mounting table 30, a transition device 60 (described later), and a buffer device 61 (described later).

[0035] The processing station 20 is provided with, for example, three processing blocks 21 to 23. The first processing block 21, the second processing block 22, and the third processing block 23 are arranged in this order from the negative side to the positive side of the X axis.

[0036] The first processing block 21 is provided with a transfer device 50, a transition device 60, a buffer device 61, an inspection device 70, a wafer modification device 71, a die modification device 72, a wafer cleaning device 73, a die cleaning device 74, a wafer hydrophilization device 75, and a die hydrophilization device 76. The number and arrangement of these various processing devices are not limited to those in this embodiment, and can be determined as desired.

[0037] The transfer device 50 is configured to be movable on a transfer path 51 extending in the X-axis direction. The transfer device 50 also has, for example, two transfer arms 52, 52 that hold and transfer the wafer W, the first carrier C1, and the second carrier C2. Each transfer arm 52 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis, and is configured to be able to transfer the wafer W, the first carrier C1, and the second carrier C2 to each of the devices 60, 61, 70 to 76 in the first processing block 21, a transition device 90 described later, and a buffer device 91 described later.

[0038] The transition device 60 and the buffer device 61 are disposed on the negative side of the X-axis of the transport device 50. The transition device 60 and the buffer device 61 are stacked in this order vertically from the top. Note that a plurality of buffer devices 61 may be stacked.

[0039] The transition device 60 transfers the wafers W, the first carrier C1, and the second carrier C2 between the transfer device 40 and the transfer device 50. The buffer device 61 temporarily stores the wafers W, the first carrier C1, and the second carrier C2.

[0040] The inspection device 70, wafer modification device 71, and die modification device 72 are arranged on the positive side of the Y axis of the transport device 50. The inspection device 70, wafer modification device 71, and die modification device 72 are stacked vertically in this order from the top. The wafer modification device 71 and die modification device 72 are arranged side by side in this order from the negative side to the positive side of the X axis.

[0041] The inspection device 70 inspects a wafer W on which a first die D1 and a second die D2 are mounted. The inspection device 70 captures an image of the wafer W using, for example, an IR camera, and inspects for the presence or absence of voids between the surface Wa of the wafer W and the dies D1, D2. The inspection device 70 may also inspect the positions of the dies D1, D2 bonded to the surface Wa of the wafer W.

[0042] The wafer modifying apparatus 71 uses plasma to modify the surface Wa of the wafer W. In the wafer modifying apparatus 71, for example, under a reduced pressure atmosphere, a process gas such as oxygen gas, nitrogen gas, hydrogen gas, or a mixture of these gases is excited to form plasma and ionized. The oxygen ions, nitrogen ions, or hydrogen ions are irradiated onto the surface Wa of the wafer W, and the surface Wa is subjected to plasma processing and modified.

[0043] Like the wafer modification device 71, the die modification device 72 also uses plasma to modify the surfaces D1a and D2a of the dies D1 and D2. In the die modification device 72, for example, under a reduced pressure atmosphere, a process gas such as oxygen gas, nitrogen gas, hydrogen gas, or a mixture of these is excited to be plasmatized and ionized. The oxygen ions, nitrogen ions, or hydrogen ions are irradiated onto the surfaces D1a and D2a of the dies D1 and D2 held by the carriers C1 and C2, and the surfaces D1a and D2a are plasma-processed and modified.

[0044] The wafer cleaning device 73, die cleaning device 74, wafer hydrophilization device 75, and die hydrophilization device 76 are arranged on the negative side of the Y axis of the transfer device 50. The wafer cleaning device 73 and die cleaning device 74, and the wafer hydrophilization device 75 and die hydrophilization device 76 are stacked vertically from the top in this order. The wafer cleaning device 73 and die cleaning device 74 are arranged side by side in this order from the negative side to the positive side of the X axis. The wafer hydrophilization device 75 and die hydrophilization device 76 are arranged side by side in this order from the negative side to the positive side of the X axis.

[0045] The wafer cleaning device 73 cleans the front surface Wa of the wafer W. In the wafer cleaning device 73, while the wafer W held by, for example, a spin chuck is rotated, a cleaning liquid such as pure water, DI water, DHF, or IPA is supplied onto the wafer W. The supplied cleaning liquid then spreads over the front surface Wa of the wafer W, cleaning the front surface Wa.

[0046] The die cleaning device 74 also cleans the surfaces D1a and D2a of the dies D1 and D2, similar to the wafer cleaning device 73. In the die cleaning device 74, a cleaning liquid is supplied onto the dies D1 and D2 held by the carriers C1 and C2 while the carriers C1 and C2 held by the chucks are rotated. The supplied cleaning liquid then spreads over the surfaces D1a and D2a of the dies D1 and D2, cleaning the surfaces D1a and D2a.

[0047] The wafer hydrophilization device 75 hydrophilizes and rinses the surface Wa of the wafer W. In the wafer hydrophilization device 75, pure water is supplied onto the wafer W while the wafer W held by, for example, a spin chuck is being rotated. The supplied pure water then spreads over the surface Wa of the wafer W, making the surface Wa hydrophilic. The surface Wa is also rinsed with the pure water.

[0048] Like the wafer hydrophilization apparatus 75, the die hydrophilization apparatus 76 hydrophilizes and rinses the surfaces D1a and D2a of the dies D1 and D2. In the die hydrophilization apparatus 76, pure water is supplied onto the dies D1 and D2 held by the carriers C1 and C2 while the carriers C1 and C2 held by, for example, spin chucks are rotated. The supplied pure water then diffuses over the surfaces D1a and D2a of the dies D1 and D2, hydrophilizing the surfaces D1a and D2a. The surfaces D1a and D2a are also rinsed by the pure water.

[0049] The second processing block 22 is provided with a transport device 80, a transition device 90, a buffer device 91, and a first bonding device 100. The number and arrangement of these various processing devices are not limited to those in this embodiment, and can be determined arbitrarily.

[0050] The transfer device 80 is configured to be movable on a transfer path 81 extending in the X-axis direction. The transfer device 80 also has, for example, two transfer arms 82, 82 that hold and transfer the wafer W, the first carrier C1, and the second carrier C2. Each transfer arm 82 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis, and is configured to be able to transfer the wafer W, the first carrier C1, and the second carrier C2 to each of the devices 90, 91, 100 in the second processing block 22, a transition device 120 described later, and a buffer device 121 described later.

[0051] The transition device 90 and the buffer device 91 are disposed on the negative side of the X-axis of the transport device 80. The transition device 90 and the buffer device 91 are stacked in this order vertically from the top. Note that a plurality of buffer devices 91 may be stacked.

[0052] The transition device 90 transfers the wafers W, the first carrier C1, and the second carrier C2 between the transfer device 50 and the transfer device 80. The buffer device 91 temporarily stores the wafers W, the first carrier C1, and the second carrier C2.

[0053] For example, two first bonding apparatuses 100 are arranged in the positive direction of the Y axis of the transfer apparatus 80, and two are arranged in the negative direction of the Y axis of the transfer apparatus 80. The first bonding apparatus 100 bonds a first die D1 (high-precision die) held by a first carrier C1 to a wafer W. That is, high bonding precision is required of the first bonding apparatus 100 (hereinafter, such a bonding apparatus may be referred to as a "high-precision bonding apparatus"). The configuration of the first bonding apparatus 100 will be described in detail later.

[0054] The third processing block 23 is provided with a transport device 110, a transition device 120, a buffer device 121, and a second bonding device 130. The number and arrangement of these various processing devices are not limited to this embodiment and can be determined arbitrarily.

[0055] The transfer device 110 is configured to be movable on a transfer path 111 extending in the X-axis direction. The transfer device 110 also has, for example, two transfer arms 112, 112 that hold and transfer the wafer W and the second carrier C2. Each transfer arm 112 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis, and is configured to be able to transfer the wafer W and the second carrier C2 to each of the devices 120, 121, and 130 in the third processing block 23.

[0056] The transition device 120 and the buffer device 121 are disposed on the negative side of the X-axis of the transport device 110. The transition device 120 and the buffer device 121 are stacked in this order vertically from the top. Note that a plurality of buffer devices 121 may be stacked.

[0057] The transition device 120 transfers the wafers W and the second carrier C2 between the transfer device 80 and the transfer device 110. The buffer device 121 temporarily stores the wafers W, the first carrier C1, and the second carrier C2.

[0058] For example, two second bonding devices 130 are arranged in the positive direction of the Y axis of the transfer device 110, and two are arranged in the negative direction of the Y axis of the transfer device 110. The second bonding device 130 bonds a second die D2 (low-precision die) held by a second carrier C2 to a wafer W. In other words, the bonding precision required of the second bonding device 130 is low (hereinafter, such a bonding device may be referred to as a "low-precision bonding device"). The configuration of the second bonding device 130 will be described in detail later.

[0059] The processing system 1 described above is provided with at least one control device 140. The control device 140 processes computer-executable instructions that cause the processing system 1 to perform the various steps described in this disclosure. The control device 140 may be configured to control each element of the processing system 1 to perform the various steps described herein. In one embodiment, part or all of the control device 140 may be included in the processing system 1. The control device 140 may include a processing unit, a storage unit, and a communication interface. The control device 140 may be implemented, for example, by a computer. The processing unit may be configured to read from the storage unit a program that provides logic or routines that enable various control operations and execute the read program to perform various control operations. This program may be stored in the storage unit in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit and read from the storage unit by the processing unit for execution. The medium may be various computer-readable storage media or a communication line connected to the communication interface. The storage medium may be temporary or non-temporary. The processing unit may be a CPU (Central Processing Unit) or one or more circuits. The storage unit may include a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface may communicate with the processing system 1 via a communication line such as a LAN (Local Area Network).

[0060] Although the processing system 1 according to this embodiment is configured as described above, other processing devices may be further arranged in the processing system 1 depending on the purpose, and some processing devices may be arranged outside the processing system 1 depending on the purpose.

[0061] Next, a description will be given of a die-ion wafer manufacturing process performed in the processing system 1 configured as described above. Fig. 7 is a flow diagram showing the main steps of the die-ion wafer manufacturing process. Fig. 8 is an explanatory diagram schematically showing some steps of the die-ion wafer manufacturing process.

[0062] First, FOUPs Fw, Fc1, and Fc2, each containing a plurality of wafers W, a first carrier C1, and a second carrier C2, are placed on the FOUP mounting table 30 of the carry-in / out station 10. At this time, a plurality of first dies D1 are held in the first carrier C1 as shown in Fig. 8(a), and a plurality of second dies D2 are held in the second carrier C2 as shown in Fig. 8(b). Furthermore, the first carrier C1 contains the first dies D1 facing upward, and the second carrier C2 contains the second dies D2 facing upward.

[0063] Next, the transfer device 40 removes the wafer W from the FOUP Fw and transfers it to the transition device 60. The wafer W transferred to the transition device 60 is transferred by the transfer device 50 to the wafer cleaning device 73. In the wafer cleaning device 73, the front surface Wa of the wafer W is cleaned with, for example, a cleaning liquid (St1 in FIG. 7 ).

[0064] Next, the wafer W is transferred by the transfer device 50 to the wafer modifying device 71. In the wafer modifying device 71, for example, plasma processing is performed under a reduced pressure atmosphere, and the surface Wa of the wafer W is modified (St2 in FIG. 7).

[0065] Next, the wafer W is transferred by the transfer device 50 to the wafer hydrophilization device 75. In the wafer hydrophilization device 75, hydroxyl groups (silanol groups) are attached to the surface Wa of the wafer W modified in St2 using, for example, pure water, thereby hydrophilizing the surface Wa. The surface Wa is also rinsed with the pure water (St3 in FIG. 7).

[0066] Next, the wafer W is transferred by the transfer device 50 to the transition device 90, and further transferred by the transfer device 80 to the first bonding device 100. Note that if the bonding process has already been performed in the four first bonding devices 100, the wafer W is transferred to the buffer device 91 and temporarily stored in the buffer device 91.

[0067] While the wafer W is undergoing the above-described processes St1 to St3, the first die D1 held in the first carrier C1 is also processed. First, the transfer device 40 removes the first carrier C1 from the FOUP Fc1 and transfers it to the transition device 60. After being transferred to the transition device 60, the transfer device 50 transfers the first carrier C1 to the die cleaning device 74. In the die cleaning device 74, the surface D1a of the first die D1 is cleaned with, for example, a cleaning liquid (St4 in FIG. 7 ).

[0068] Next, the first carrier C1 is transported by the transport device 50 to the die modifying device 72. In the die modifying device 72, for example, plasma processing is performed under a reduced pressure atmosphere to modify the surface D1a of the first die D1 (St5 in FIG. 7).

[0069] Next, the first carrier C1 is transported by the transport device 50 to the die hydrophilization device 76. In the die hydrophilization device 76, hydroxyl groups (silanol groups) are attached to the surface D1a of the first die D1 modified in St5 using, for example, pure water, thereby hydrophilizing the surface D1a. The surface D1a is also rinsed with the pure water (St6 in FIG. 7).

[0070] Next, the first carrier C1 is transported by the transport device 50 to the transition device 90, and further transported by the transport device 80 to the first joining device 100. Note that if the joining process has already been performed in the four first joining devices 100, the first carrier C1 is transported to the buffer device 91 and temporarily stored therein.

[0071] While the wafer W is subjected to the processes St1 to St3 described above and the first die D1 is subjected to the processes St4 to St6 described above, the second die D2 held in the second carrier C2 is processed. First, the transfer device 40 removes the second carrier C2 from the FOUP Fc2 and transfers it to the transition device 60. The second carrier C2 transferred to the transition device 60 is then transferred by the transfer device 50 to the die cleaning device 74. In the die cleaning device 74, the surface D2a of the second die D2 is cleaned with, for example, a cleaning liquid (St7 in FIG. 7 ).

[0072] Next, the second carrier C2 is transported by the transport device 50 to the die modifying device 72. In the die modifying device 72, for example, plasma processing is performed under a reduced pressure atmosphere, and the surface D2a of the second die D2 is modified (St8 in FIG. 7).

[0073] Next, the second carrier C2 is transported by the transport device 50 to the die hydrophilization device 76. In the die hydrophilization device 76, hydroxyl groups (silanol groups) are attached to the surface D2a of the second die D2 modified in St8 using, for example, pure water, thereby hydrophilizing the surface D2a. The surface D2a is also rinsed with the pure water (St9 in FIG. 7).

[0074] Next, the second carrier C2 is transported by the transport device 50 to the transition device 90, then by the transport device 80 to the transition device 120, and then by the transport device 110 to the second joining device 130. Note that if the joining process has already been performed in the four second joining devices 130, the second carrier C2 is transported to the buffer device 121 and temporarily stored therein.

[0075] The wafer W that has been subjected to the processes of St1 to St3 described above is transferred to the first bonding apparatus 100, and the first carrier C1 that has been subjected to the processes of St4 to St6 described above is transferred to the first bonding apparatus 100. In the first bonding apparatus 100, the first die D1 held by the first carrier C1 is removed from the first carrier C1 and picked up. Furthermore, as shown in FIG. 8( c), the surface D1 a of the picked-up first die D1 is brought into contact with the surface Wa of the wafer W, and the first die D1 is pressed against the wafer W, thereby bonding the first die D1 to the wafer W (St10 in FIG. 7 ).

[0076] In St10, because the surface Wa of the wafer W and the surface D1a of the first die D1 have been modified in St2 and St5, respectively, van der Waals forces (intermolecular forces) are generated between the surfaces Wa and D1a, thereby bonding the surfaces Wa and D1a together. Furthermore, because the surface Wa of the wafer W and the surface D1a of the first die D1 have been hydrophilized in St3 and St6, respectively, the hydrophilic groups between the surfaces Wa and D1a form hydrogen bonds (intermolecular forces), thereby firmly bonding the surfaces Wa and D1a together.

[0077] As described above, the first bonding apparatus 100 is a high-precision bonding apparatus. The first die D1 includes a device layer E on which circuits and the like are formed, and high bonding precision is required. In St10, the first die D1 can be bonded to a desired position on the wafer W with high precision.

[0078] In St10, when all the first dies D1 held in the first carrier C1 are bonded to the wafers W, the first carrier C1 is transferred to the transition device 90 by the transfer device 80, transferred to the transition device 60 by the transfer device 50, and further transferred to the FOUP Fc1 by the transfer device 40. On the other hand, if the first die D1 remains in the first carrier C1 after St10, the first carrier C1 may remain in the first bonding device 100, and the first die D1 may be bonded to the subsequent wafer W. Alternatively, if the first die D1 remains in the first carrier C1 after St10, the first carrier C1 may be transferred to the buffer device 91 by the transfer device 80 and temporarily stored in the buffer device 91.

[0079] On the other hand, in St10, when the first die D1 is bonded to all of the desired positions on the wafer W, the wafer W is transferred by the transfer device 80 to the transition device 120, and then transferred by the transfer device 110 to the second bonding device 130. Note that if the bonding process has already been performed in the four second bonding devices 130, the wafer W is transferred to the buffer device 121 and temporarily stored in the buffer device 121.

[0080] The second carrier C2, which has been subjected to the processes of St7 to St9 described above, is transferred to the second bonding device 130. In the second bonding device 130, the second die D2 held by the second carrier C2 is removed from the second carrier C2 and picked up. Furthermore, as shown in FIG. 8D, the surface D2a of the picked-up second die D2 is brought into contact with the surface Wa of the wafer W, and the second die D2 is pressed against the wafer W, thereby bonding the second die D2 to the wafer W (St11 in FIG. 7).

[0081] In St11, because the surface Wa of the wafer W and the surface D2a of the second die D2 have been modified in St2 and St8, respectively, van der Waals forces (intermolecular forces) are generated between the surfaces Wa and D2a, thereby bonding the surfaces Wa and D2a together. Furthermore, because the surface Wa of the wafer W and the surface D2a of the second die D2 have been hydrophilized in St3 and St9, respectively, the hydrophilic groups between the surfaces Wa and D2a form hydrogen bonds (intermolecular forces), thereby firmly bonding the surfaces Wa and D2a together.

[0082] As described above, the second bonding apparatus 130 is a low-precision bonding apparatus. Since the second die D2 does not have a circuit or the like formed thereon and therefore requires low bonding precision, the second die D2 is bonded to a desired position on the wafer W with low precision in St11. In this case, since low bonding precision is sufficient, the time required for St11 can be shortened.

[0083] In St11, when all the second dies D2 held in the second carrier C2 are bonded to the wafers W, the second carrier C2 is transferred to the transition device 120 by the transfer device 110, transferred to the transition device 90 by the transfer device 80, transferred to the transition device 60 by the transfer device 50, and further transferred to the FOUP Fc2 by the transfer device 40. On the other hand, if the second die D2 remains in the second carrier C2 after St11, the second carrier C2 may remain in the second bonding device 130, and the second die D2 may be bonded to the subsequent wafer W. Alternatively, if the second die D2 remains in the second carrier C2 after St11, the second carrier C2 may be transferred to the buffer device 121 by the transfer device 110 and temporarily stored in the buffer device 121.

[0084] 1 , the wafer W is transferred to the transition device 120 by the transfer device 110, transferred to the transition device 90 by the transfer device 80, and transferred to the inspection device 70 by the transfer device 50. The inspection device 70, for example, takes an image of the wafer W and inspects for the presence or absence of voids between the front surface Wa of the wafer W and the dies D1 and D2 (St12 in FIG. 7 ). Note that the inspection device 70 may inspect the positions of the dies D1 and D2 bonded to the front surface Wa of the wafer W.

[0085] Next, the wafer W is transferred to the transition device 60 by the transfer device 50, and further transferred to the FOUP Fw by the transfer device 40. In this way, a series of die-on wafer manufacturing processes is completed.

[0086] The FOUPs into which the wafers W, the first carrier C1, and the second carrier C2 are recovered do not necessarily have to be the same FOUPs that housed the wafers W, the first carrier C1, and the second carrier C2, respectively, when they were loaded in. That is, for example, the FOUPs that housed the wafers W, the first carrier C1, and the second carrier C2, respectively, may each carry out different members, or new FOUPs or the like may be loaded into the processing system 1 for carrying out the wafers W, the first carrier C1, and the second carrier C2.

[0087] According to the above embodiment, the processing system 1 includes the first bonding apparatus 100, which is a high-precision bonding apparatus, and the second bonding apparatus 130, which is a low-precision bonding apparatus. The first die D1 includes a device layer E on which circuits and the like are formed, and therefore requires high bonding accuracy. The first bonding apparatus 100 can bond the first die D1 to a desired position on the wafer W with high accuracy. The second die D2 does not include circuits and therefore requires low bonding accuracy. The second bonding apparatus 130 bonds the second die D2 to a desired position on the wafer W with low accuracy. Since low bonding accuracy is sufficient, the time required for bonding the second die D2 to the wafer W can be shortened. Therefore, the throughput of the die-on-wafer manufacturing process can be improved while appropriately mounting multiple types of first dies D1 and second dies D2 on the wafer W with the required bonding accuracy.

[0088] In this embodiment, the second bonding device 130 is a low-precision bonding device, and as described below, the device configuration can be reduced to lower precision specifications compared to a high-precision bonding device. As a result, the device cost of the second bonding device 130 can be reduced, and the device cost of the processing system 1 can be reduced.

[0089] Next, the configurations of the above-described first welding apparatus 100 and second welding apparatus 130 will be described. The required welding precision differs between the first welding apparatus 100 and the second welding apparatus 130, so first the configuration of the first welding apparatus 100 will be described, and then the configuration of the second welding apparatus 130 will be described, focusing on the differences from the first welding apparatus 100. Figure 9 is a perspective view showing an outline of the configuration of the first welding apparatus 100.

[0090] As shown in Fig. 9, the first bonding apparatus 100 has a stage 200. The stage 200 is divided into a de-bonding area 201 and a bonding area 202. The de-bonding area 201 and the bonding area 202 are arranged side by side in the horizontal direction (X-axis direction). In the de-bonding area 201, the first die D1 held by the first carrier C1 is de-bonded from the first carrier C1 and picked up. In the bonding area 202, the first die D1 picked up in the de-bonding area 201 is bonded to a wafer W.

[0091] A carrier holding unit 210 is provided in the separation area 201. The carrier holding unit 210 has a holding surface of the first carrier C1 on its upper surface, and holds the first carrier C1 holding the first die D1 in a state where the surface D1a of the first die D1 faces upward.

[0092] A moving mechanism 211 is provided below the carrier holding unit 210. The moving mechanism 211 is configured to allow the carrier holding unit 210 to move in horizontal directions (X-axis direction and Y-axis direction). The moving mechanism 211 is also configured to allow the carrier holding unit 210 to rotate around a vertical axis. The driving unit of the moving mechanism 211 is not particularly limited, but a linear motor, for example, is used.

[0093] An air cap 220 serving as an air supply unit is provided inside the carrier holding unit 210. An air supply source (not shown) that supplies air to the air cap 220 is connected to the air cap 220. The air cap 220 supplies air to the through-hole H1 of the first carrier C1 held by the carrier holding unit 210, and further supplies air to the back surface D1b of the first die D1 on the first carrier C1 via the through-hole H1. This applies air pressure to the first die D1, thereby reducing the adhesion between the first die D1 and the insulating layer N1 on the suction surface of the first carrier C1. This allows the first die D1 to be detached from the suction surface of the first carrier C1.

[0094] A pickup unit 230 is provided above the carrier holding unit 210. The pickup unit 230 picks up and transports the first die D1 from the first carrier C1. Specifically, the pickup unit 230 holds the first die D1 that has been lifted up (lifted up) due to a decrease in adhesion between the first die D1 and the insulating layer N1 caused by the supply of air from the air cap 220, removes the first die D1 from the first carrier C1, and then transports the held first die D1 from the removal region 201 to the bonding region 202.

[0095] The pickup unit 230 may hold the first die D1 in any manner. However, since the surface D1a of the first die D1 held by the pickup unit 230 is the device surface of the device layer E, the pickup unit 230 must hold the first die D1 without damaging the device surface. For example, the pickup unit 230 may be a collet chuck, or a non-contact chuck that can hold the first die D1 from above without contact using the Bernoulli effect or ultrasonic squeeze effect. Alternatively, instead of holding the surface D1a of the first die D1, the pickup unit 230 may be configured to hold the first die D1 by clamping the side surface of the first die D1 that has been raised by, for example, supplying air.

[0096] The pickup unit 230 is supported by a moving mechanism 231. The moving mechanism 231 supports and moves the pickup unit 230. The moving mechanism 231 has an arm 232, a rail 233, a support member 234, and a drive unit 235. The tip of the arm 232 supports the pickup unit 230, and the base end is attached to the rail 233. The rail 233 extends in the X-axis direction and is supported by the support member 234. The drive unit 235 moves the pickup unit 230 in the X-axis direction (a direction along the rail 233), the Y-axis direction, and the vertical direction. The drive unit 235 also rotates the pickup unit 230 around a horizontal axis (around the X-axis), allowing the pickup unit 230 to flip the front and back surfaces of the held first die D1. The drive unit 235 also rotates the pickup unit 230 around a vertical axis, allowing the position of the held first die D1 in the rotational direction (θ-axis direction). The drive source of the drive unit 235 is not particularly limited, but may be, for example, a linear motor.

[0097] A first imaging unit 240 is provided above the carrier holding unit 210. For example, a camera is used as the first imaging unit 240. The first imaging unit 240 images at least two points of the first die D1 on the first carrier C1 held by the carrier holding unit 210 from above. The first imaging unit 240 is fixed, and images the two points of the first die D1 by moving the carrier holding unit 210. The captured images are output to the control device 140, which measures the position of the first die D1 on the first carrier C1. The control device 140 controls the moving mechanism 231 based on the measured position of the first die D1, and adjusts the position of the pickup unit 230 so that the pickup unit 230 appropriately picks up the first die D1.

[0098] A second imaging unit 241 is provided on the positive X-axis side of the carrier holding unit 210, below the pickup unit 230. The second imaging unit 241 may be, for example, a camera. The second imaging unit 241 captures images of at least two points on the first die D1 held by the pickup unit 230 from below. The second imaging unit 241 is fixed, and the pickup unit 230 is moved to capture images of the two points on the first die D1. The captured images are output to the control device 140, which measures the position of the first die D1 held by the pickup unit 230. The control device 140 controls the moving mechanism 231 based on the measured position of the first die D1, and adjusts the position of the pickup unit 230 so that the pickup unit 230 can transfer the first die D1 to an appropriate position on a bond head 261 (described later).

[0099] A wafer holding part 250 serving as a substrate holding part is provided in the bonding region 202. The wafer holding part 250 has a holding surface for the wafer W on its upper surface, and holds the wafer W with the front surface Wa, which is the mounting surface of the first die D1, facing upward. The wafer holding part 250 is supported by a support plate 251.

[0100] A moving mechanism 252 is provided below the support plate 251. The moving mechanism 252 is configured to move the wafer holding part 250 and the support plate 251 in horizontal directions (X-axis direction and Y-axis direction). The moving mechanism 252 is also configured to rotate the wafer holding part 250 and the support plate 251 around a vertical axis. The drive part of the moving mechanism 252 is not particularly limited, but a linear motor, for example, is used.

[0101] A head unit 260 is provided above the wafer holding unit 250. The head unit 260 receives and holds the first die D1 from the pickup unit 230, transports the held first die D1 to the wafer W, and bonds the first die D1 to the wafer W. As shown in FIG. 10 , the head unit 260 has a bond head 261, an insulating plate 262 as an insulator, and a base 263.

[0102] The bond head 261 receives from above and holds the first die D1 held by the pickup unit 230. The holding surface (lower surface) of the bond head 261 for the first die D1 has a convex shape with the center protruding downward.

[0103] The bond head 261 may hold the first die D1 in any manner. Because the back surface D1b of the first die D1 held by the bond head 261 is the silicon layer S1, the bond head 261 does not necessarily need to be configured as a collet chuck or a non-contact chuck, as in the pickup unit 230. For example, a vacuum chuck may be used for the bond head 261, and the bond head 261 may suck and hold the first die D1 by vacuuming it using a vacuum mechanism (not shown).

[0104] The bond head 261 is made of a conductive material, such as a metal, and is supported by an insulating plate 262 as described below, and is electrically floating.

[0105] The insulating plate 262 is larger than the bond head 261 and holds the entire upper surface of the bond head 261. The method of holding the bond head 261 by the insulating plate 262 is arbitrary. For example, the insulating plate 262 may hold the bond head 261 by suction using a vacuum mechanism (not shown). In such a case, the bond head 261 is configured to be detachable from the insulating plate 262 and to be replaceable.

[0106] The insulating plate 262 is made of a material that transmits light and has insulating properties, such as glass. As will be described later, the imaging units 280, 281, and 282 capture images of the four alignment marks 265, and the imaging units 281 and 282 capture images of the wafer W. Therefore, the insulating plate 262 is made transparent so as to transmit light.

[0107] The base 263 supports the outer periphery of the upper surface of the insulating plate 262. The base 263 has an annular shape, and an opening 263a is formed in the center of the base 263. The opening 263a is formed to be at least larger than the bond head 261, that is, the bond head 261 held by the insulating plate 262 is disposed inside the opening 263a in a plan view.

[0108] The base 263 is made of a conductive material, such as a metal, and is connected to a ground potential.

[0109] A conductive film 264 serving as a ground connection body is formed on the surface of the insulating plate 262. The conductive film 264 extends over the lower and side surfaces of the insulating plate 262 and is formed so as to connect the upper surface of the bond head 261 to the lower surface of the base 263. Specifically, the conductive film 264 is formed so as to cover the entire upper surface of the bond head 261 between the upper surface of the bond head 261 and the lower surface of the insulating plate 262. The conductive film 264 is also formed so as to contact a portion of the lower surface of the base 263.

[0110] The conductive film 264 is made of a conductive material, such as a metal. The conductive film 264 is preferably a transparent conductive film that transmits light, and may be, for example, an ITO (indium tin oxide) thin film, which is indium oxide doped with tin oxide. The ITO thin film is formed by electron beam evaporation or sputtering evaporation. Alternatively, the ITO thin film may be formed by coating. In this case, the bond head 261 is connected to ground potential via the conductive film 264 and the base 263.

[0111] A plurality of, for example, four alignment marks 265 are provided on the lower surface of the insulating plate 262. The four alignment marks 265 are arranged outside the bond head 261 held by the insulating plate 262 and inside the opening 263 a in plan view.

[0112] As shown in Figure 9, a third imaging unit 280 (described later) is provided below the head unit 260, and a fourth imaging unit 281 (described later) and a fifth imaging unit 282 (described later) are provided above the head unit 260. These imaging units 280, 281, and 282 move slightly over time, so they need to be aligned at the desired timing. This alignment is performed by having the imaging units 280, 281, and 282 capture images of the four alignment marks 265. For this reason, the insulating plate 262 is made transparent.

[0113] Furthermore, a fourth imaging unit 281 and a fifth imaging unit 282, which will be described later, each capture an image of the wafer W held by the wafer holding unit 250 below the head unit 260. The fourth imaging unit 281 and the fifth imaging unit 282 each capture an image of the wafer W via the insulating plate 262, outside the bond head 261 and inside the opening 263a in a plan view. For this reason, the insulating plate 262 is configured to be transparent.

[0114] The head unit 260 is supported by a moving mechanism 270. The moving mechanism 270 supports and moves the head unit 260. The moving mechanism 270 has an arm 271, a rail 272, a support member 273, and a drive unit 274. The tip of the arm 271 supports the base 263 of the head unit 260, and the base end is attached to the rail 272. The rail 272 extends in the X-axis direction and is supported by the support member 273. The drive unit 274 moves the head unit 260 in the X-axis direction (the direction along the rail 272), the Y-axis direction, and the vertical direction. The drive unit 274 can also rotate the head unit 260 around the vertical axis to adjust the position of the held first die D1 in the rotational direction (θ-axis direction). The drive source of the drive unit 274 is not particularly limited, but a linear motor, for example, can be used.

[0115] A third imaging unit 280 is provided below the head unit 260. For example, a camera is used as the third imaging unit 280. The third imaging unit 280 images at least two points on the first die D1 held by the bond head 261 from below while the wafer holding unit 250 is retracted to a position where it does not overlap the third imaging unit 280 in a plan view. The third imaging unit 280 is fixed, and images the two points on the first die D1 by moving the bond head 261. The captured images are output to the control device 140, and the position of the first die D1 held by the bond head 261 is measured in the control device 140.

[0116] A fourth imaging unit 281 is provided above the head unit 260, specifically above the opening 263a of the base 263. For example, a camera is used as the fourth imaging unit 281. The fourth imaging unit 281 images at least two points on the wafer W held by the wafer holding unit 250 from above. At least one of the fourth imaging unit 281 and the wafer holding unit 250 is moved to image the two points on the wafer W. The captured images are output to the control device 140, and the position of the wafer W held by the control device 140 is measured.

[0117] The control device 140 adjusts the position of the first die D1 relative to the wafer W based on the position of the first die D1 measured using the third imaging unit 280 and the position of the wafer W measured using the fourth imaging unit 281. Specifically, the control device 140 controls at least one of the moving mechanism 252 and the moving mechanism 270 to move at least one of the first die D1 and the wafer W, thereby adjusting the position of the first die D1 relative to the wafer W so that the first die D1 is bonded to an appropriate position relative to the wafer W.

[0118] A fifth imaging unit 282 is provided above the head unit 260, specifically above the opening 263a of the base 263. The fifth imaging unit 282 is, for example, an IR camera. The fifth imaging unit 282 captures an image of the first die D1 mounted on the wafer W from above. The captured image is output to the control device 140, and the position of the first die D1 relative to the wafer W is measured in the control device 140. That is, the control device 140 inspects the bonding accuracy of the first die D1 relative to the wafer W.

[0119] The fourth imaging unit 281 and the fifth imaging unit 282 may each be supported by an arm 271 of the moving mechanism 270 via a support member (not shown), and may be configured to be movable in the horizontal direction (X-axis direction and Y-axis direction) by the moving mechanism 270. Alternatively, the fourth imaging unit 281 and the fifth imaging unit 282 may each be supported by a moving mechanism (not shown) separate from the moving mechanism 270, and may be configured to be movable in the horizontal direction (X-axis direction and Y-axis direction) by the moving mechanism.

[0120] Next, a method for bonding the first die D1 to the wafer W using the first bonding apparatus 100 configured as above will be described.

[0121] First, a wafer W and a first carrier C1 holding a plurality of first dies D1 are transported to the first bonding apparatus 100. The wafer W is held by the wafer holding part 250 with its front surface Wa facing upward. At this time, the wafer holding part 250 is disposed in a position that does not overlap with the third imaging part 280 in a plan view, for example, on the positive X-axis side of the third imaging part 280. The first carrier C1 is held by the carrier holding part 210 with the front surface D1a of the first die D1 facing upward.

[0122] Next, the first imaging unit 240 images at least two points of one of the first dies D1 to be joined among the first dies D1 on the first carrier C1 held by the carrier holding unit 210. The captured image is output to the control device 140, which measures the position of the first die D1 on the first carrier C1. The control device 140 controls the moving mechanism 231 based on the measured position of the first die D1 to move the carrier holding unit 210 and adjust the position of the pickup unit 230 and the first die D1 to be picked up by the pickup unit 230.

[0123] Next, the air cap 220 selectively supplies air to the through hole H1 corresponding to one of the first dies D1 to be joined, causing the insulating layer N1 to expand, thereby pushing up the one of the first dies D1 from below and lifting it up.

[0124] Next, the pickup unit 230 is lowered, and the surface D1a of one of the first dies D1 that has been lifted is held by the pickup unit 230. The pickup unit 230 may hold the first die D1 before lifting the first die D1 with air, or may hold the first die D1 at the same time as lifting the first die D1 with air. Next, the pickup unit 230 is raised, and the first die D1 is picked up from the first carrier C1.

[0125] Next, the pickup unit 230 is moved in the positive direction of the X-axis until it is above the second imaging unit 241. The second imaging unit 241 captures images of at least two points of the first die D1 held by the pickup unit 230 from below. The captured images are output to the control device 140, which measures the position of the first die D1 held by the pickup unit 230. The control device 140 controls the moving mechanism 231 based on the measured position of the first die D1, and adjusts the position of the pickup unit 230 so that the first die D1 is delivered to the center of the bond head 261.

[0126] Next, the pickup unit 230 is rotated around the horizontal axis (around the X axis), thereby inverting the front and back surfaces of the first die D1, so that the back surface D1b of the first die D1 held by the pickup unit 230 faces upward.

[0127] Next, the pickup unit 230 is further moved in the positive direction of the X-axis until it is below the bond head 261. Subsequently, the pickup unit 230 transfers the first die D1 to the bond head 261. The first die D1 is placed in the center of the bond head 261.

[0128] Next, the third imaging unit 280 captures images of at least two points from below on the first die D1 held by the bond head 261. The captured images are output to the control device 140, and the control device 140 measures the position of the first die D1 held by the bond head 261.

[0129] Next, the wafer holding unit 250 is moved below the bond head 261 (fourth imaging unit 281). Subsequently, the fourth imaging unit 281 captures images of at least two points on the wafer W held by the wafer holding unit 250 from above. The captured images are output to the control device 140, which measures the position of the wafer W held by the wafer W. Based on the position of the first die D1 measured using the third imaging unit 280 and the position of the wafer W measured using the fourth imaging unit 281, the control device 140 adjusts the position of the first die D1 relative to the wafer W so that the first die D1 is bonded to an appropriate position relative to the wafer W.

[0130] Next, the bond head 261 is lowered, the surface D1a of the first die D1 held by the bond head 261 is brought into contact with the surface Wa of the wafer W, and the first die D1 is pressed to bond the first die D1 to the wafer W. Subsequently, the bond head 261 is raised.

[0131] As described above, the holding surface (lower surface) of the bond head 261 for holding the first die D1 has a convex shape with a central portion protruding downward. For example, if the first die D1 is held off-center on the bond head 261, pressing the first die D1 against the wafer W will result in poor surface pressure accuracy of the first die D1 relative to the wafer W, resulting in voids between the wafer W and the first die D1. In this regard, in this embodiment, the position of the pickup unit 230 is adjusted based on the image of the first die D1 captured by the second imaging unit 241, so that the first die D1 is appropriately held at the center of the bond head 261. Therefore, when bonding the first die D1 to the wafer W, the surface pressure accuracy of the first die D1 relative to the wafer W can be improved, and voids can be suppressed.

[0132] In this manner, the bonding operation of the first die D1 to the wafer W is performed. The bonding operation of the first die D1 is performed independently and continuously for each of the plurality of first dies D1 held by suction on the first carrier C1.

[0133] Once the first die D1 has been bonded to all of the desired positions on the wafer W, the fifth imaging unit 282 then captures an image of the first die D1 mounted on the wafer W from above. The captured image is output to the control device 140, which measures the position of the first die D1 relative to the wafer W and inspects the bonding accuracy of the first die D1 relative to the wafer W. In this way, a series of bonding processes in the first bonding apparatus 100 is completed.

[0134] According to the above embodiment, in the first bonding apparatus 100, the bond head 261 of the head unit 260 is used to repeatedly bond the first die D1 to the wafer W. That is, the bond head 261 repeatedly receives the first die D1 from the pickup unit 230 and delivers the first die D1 to the wafer W.

[0135] Conventionally, bond heads are held on an insulating plate and electrically floating. Therefore, when the bond head repeatedly receives and transfers dies, the bond head becomes charged. When the bond head is charged in this way, when the bond head receives a die from the pickup unit, the bond head discharges electricity and current flows from the bond head to the die. This can damage the circuit (device) on the die.

[0136] In this regard, in this embodiment, the bond head 261 is connected to the ground potential via the conductive film 264 and the base 263. Therefore, even if the bond head 261 is used to repeatedly receive and transfer the first die D1, the bond head 261 can be prevented from becoming charged. As a result, damage to the circuit of the first die D1 can be prevented. Also, adhesion of particles to the first die D1 can be prevented. Therefore, the first die D1 can be properly mounted on the wafer W, and product quality can be improved.

[0137] Furthermore, various position adjustments (alignments) are performed in the first bonding apparatus 100. That is, the first imaging unit 240 is used to adjust the positions of the pickup unit 230 and the first die D1 picked up by the pickup unit 230. The second imaging unit 241 is used to adjust the position of the pickup unit 230 so that the first die D1 is delivered to the center of the bond head 261. The third imaging unit 280 and the fourth imaging unit 281 are used to adjust the position of the first die D1 relative to the wafer W. This allows the first die D1 to be bonded to an appropriate position on the wafer W. This also allows voids to be suppressed when bonding the first die D1 to the wafer W. Therefore, the first bonding apparatus 100 can bond the first die D1 to the wafer W with high bonding accuracy.

[0138] Furthermore, in the first bonding apparatus 100, by increasing the rigidity of the moving mechanism 211, the arm 232 of the moving mechanism 231, the moving mechanism 252, and the arm 271 of the moving mechanism 270, it is possible to improve the accuracy of the movement of the carrier holding unit 210, the movement of the pickup unit 230, the movement of the wafer holding unit 250, and the movement of the head unit 260. In this case, it is possible to improve the accuracy of bonding the first die D1 to the wafer W in the first bonding apparatus 100.

[0139] Furthermore, in the first bonding apparatus 100, by improving the performance of each of the drive unit of the moving mechanism 211, the drive unit 235 of the moving mechanism 231, the drive unit of the moving mechanism 252, and the drive unit 274 of the moving mechanism 231, it is possible to speed up the movement of the carrier holding unit 210, the movement of the pickup unit 230, the movement of the wafer holding unit 250, and the movement of the head unit 260. As a result, it is possible to shorten the time required for the bonding process in the first bonding apparatus 100.

[0140] Next, the configuration of the second joining device 130 will be described, focusing on the differences from the first joining device 100. The second joining device 130 is a low-precision joining device, and compared to the first joining device 100, the device configuration can be kept to lower precision specifications.

[0141] For example, the second bonding apparatus 130 can omit at least one of the first imaging unit 240, the third imaging unit 280, and the fourth imaging unit 281 because low positional accuracy of the second die D2 relative to the wafer W is sufficient. Also, the second imaging unit 241 can be omitted if it is not necessary to suppress voids when bonding the second die D2 to the wafer W. Furthermore, the fifth imaging unit 282 can be omitted if low bonding accuracy of the second die D2 relative to the wafer W is sufficient and inspection is not necessary.

[0142] Furthermore, in the second bonding apparatus 130, by improving the performance of each of the drive units of the moving mechanism 211, the drive unit 235 of the moving mechanism 231, the drive unit of the moving mechanism 252, and the drive unit 274 of the moving mechanism 270, it is possible to increase the speed of the movement of the carrier holding unit 210, the movement of the pickup unit 230, the movement of the wafer holding unit 250, and the movement of the head unit 260. On the other hand, since improving the performance of each drive unit in this way results in the drive unit becoming larger, it is preferable to reduce the rigidity of, for example, the moving mechanism 211, the rigidity of the arm 232 of the moving mechanism 231, the rigidity of the moving mechanism 252, and the rigidity of the arm 271 of the moving mechanism 270. In this regard, since the bonding precision required for the second bonding apparatus 130 is low, it is possible to reduce these rigidities.

[0143] As described above, the second bonding apparatus 130 can have a lower-precision device configuration and can also have lower-precision bonding conditions than the first bonding apparatus 100. This reduces the time required for bonding processing in the second bonding apparatus 130. Note that the second bonding apparatus 130 can have the same device configuration as the first bonding apparatus 100, and only the bonding conditions can be set to lower-precision specifications.

[0144] The bonding conditions are conditions for bonding the first die D1 and the second die D2 to the wafer W, and are equipment parameters. The equipment parameters include, for example, the acceleration / deceleration and speed of the movement of the carrier holding unit 210, the pickup unit 230, the wafer holding unit 250, and the head unit 260 by the movement mechanisms 211, 231, 252, and 270, and the waiting time until the drive of the drive units of these movement mechanisms 211, 231, 252, and 270 stabilizes. The equipment parameters also include whether or not to capture images by the image capturing units 240, 241, 280, 281, and 282, and the image capturing time.

[0145] In the second bonding apparatus 130 described above, the bond head 261 is also connected to the ground potential via the conductive film 264 and the base 263. This prevents the bond head 261 from becoming charged even when the second die D2 is repeatedly received and transferred using the bond head 261. As a result, it is possible to prevent particles from adhering to the second die D2, and the second die D2 can be properly mounted on the wafer W.

[0146] In the first welding device 100 and the second welding device 130 of the above embodiment, the release region 201 and the welding region 202 are arranged side by side in the horizontal direction (X-axis direction), but they may be arranged stacked in the vertical direction, for example. In this case, the footprints (occupied areas) of the first welding device 100 and the second welding device 130 can be kept small.

[0147] In the above embodiment, in the first bonding apparatus 100 and the second bonding apparatus 130, the conductive film 264 is used as the ground connector that connects the bond head 261 to the ground potential, but the configuration of the ground connector is not limited to this.

[0148] 11 , the ground connector 300 may include a conductor 301 and conductive films 302 and 303. The conductor 301 is inserted through a through-hole 262a formed in the thickness direction of the insulating plate 262 to connect the conductive films 302 and 303. The lower conductive film 302 is formed between the upper surface of the bond head 261 and the lower surface of the insulating plate 262 so as to cover the entire upper surface of the bond head 261. The upper conductive film 303 is formed so as to extend over the upper surface of the insulating plate 262 and contact part of the side surface of the base 263.

[0149] The conductor 301 and the conductive films 302 and 303 are each made of a conductive material, such as a metal. The conductor 301 and the conductive films 302 and 303 are preferably made of a transparent, conductive material that transmits light, such as indium tin oxide (ITO), which is indium oxide doped with tin oxide. In this case, the bond head 261 is connected to ground potential via the lower conductive film 302, the conductor 301, the upper conductive film 303, and the base 263. In this case, even if the bond head 261 is used to repeatedly receive and transfer the dies D1 and D2, the bond head 261 can be prevented from becoming charged.

[0150] In the above embodiment, the bond head 261 is connected to a ground potential to prevent the bond head 261 from becoming charged, but the bond head 261 may also be neutralized. For example, as shown in FIG. 12 , in the first bonding apparatus 100 (second bonding apparatus 130), a neutralization unit 310 is provided below the head unit 260. The neutralization unit 310 may be, for example, an ionizer. Ions are supplied from the neutralization unit 310 to the bond head 261, thereby neutralizing the bond head 261. The neutralization unit 310 may also be, for example, a light irradiation unit. Light is irradiated from the neutralization unit 310 to the bond head 261, thereby neutralizing the bond head 261.

[0151] In this case, since the bond head 261 is connected to ground potential and is neutralized by the neutralization unit 310, charging of the bond head 261 can be further suppressed even when the bond head 261 is used to repeatedly receive and transfer the dies D1 and D2. Note that it is also possible to neutralize the bond head 261 using only the neutralization unit 310, but in this case, neutralization takes time and the charge on the bond head 261 cannot be fully suppressed. For this reason, it is preferable to connect the bond head 261 to ground potential as in this embodiment.

[0152] In the above embodiment, the first carrier C1 holds a plurality of first dies D1, and the second carrier C2 holds a plurality of second dies D2, but one carrier may hold a plurality of first dies D1 and a plurality of second dies D2. Alternatively, one carrier may hold three or more types of dies, and the pattern of dies held by one carrier is arbitrary.

[0153] In the above embodiment, the case where the first die D1 and the second die D2 are mounted on the wafer W has been described. However, three or more types of dies may be mounted on the wafer W. For example, a third die D3 may be mounted on the wafer W in addition to the first die D1 and the second die D2. In such a case, the processing system 1 may be provided with a dedicated bonding device (not shown) for bonding the third die D3 to the wafer W. Alternatively, for example, if the third die D3 is a low-precision die, the second die D2 and the third die D3 may be bonded to the wafer W by replacing the bond head 261 in the second bonding device 130.

[0154] In the above embodiment, the dies D1 and D2 held by the carriers C1 and C2 are mounted on the wafer W, but the carriers that hold the dies D1 and D2 before mounting are not limited to the carriers C1 and C2 of the above embodiment. For example, the dies D1 and D2 may be attached to a dicing tape fixed to a dicing frame. The silicon layers S1 and S2 on the backsides D1b and D2b of the dies D1 and D2 are attached to the dicing tape.

[0155] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.

[0156] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that would be apparent to a person skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0157] REFERENCE SIGNS LIST 100 First bonding device 130 Second bonding device 250 Wafer holder 260 Head 261 Bond head 262 Insulating plate 264 Conductive film D1 First die D2 Second die W Wafer

Claims

1. A bonding apparatus for bonding multiple dies to a target substrate, comprising: a substrate holding section for holding the target substrate; and a head section for bonding the dies to the target substrate held by the substrate holding section, wherein the head section comprises: a conductive bond head for holding the dies; an insulator for holding the bond head; and a ground connection for connecting the bond head to a ground potential.

2. The joining device according to claim 1, wherein the ground connection body includes a conductive film formed on the surface of the insulator.

3. The joining device according to claim 2, wherein the ground connection body includes a conductor that passes through a through hole formed in the thickness direction of the insulator.

4. The joining device of claim 1, wherein the ground connection is optically transparent.

5. The bonding device of claim 4, wherein the ground connection is constructed from indium tin oxide.

6. The joining device of claim 1, wherein the insulator is optically transparent.

7. The joining device according to claim 1, wherein the head portion has a base that supports the insulator, and the ground connection body is connected to the base.

8. The bonding device described in claim 7, wherein the base supports the outer periphery of the upper surface of the insulator, an opening is formed in the center of the base, the insulator holds the upper surface of the bond head, the bond head is positioned inside the opening in a planar view, and the ground connection body includes a conductive film formed between the upper surface of the bond head and the lower surface of the insulator.

9. The bonding apparatus according to claim 1, further comprising a static eliminator for eliminating static electricity from the bond head.

10. The bonding apparatus according to claim 1, further comprising a pickup section that picks up a die from a carrier that holds a plurality of the dies, and the bond head receives the die from the pickup section and bonds the die to the target substrate.

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