Bonding device and bonding method

Abstract

A bonding device according to the present invention performs alignment of a die and a substrate on the basis of relative positions of a first mark on the die and a second mark on the substrate, and bonds the die and the substrate. The bonding device is provided with a first detection unit that detects at least one of the first mark and the second mark. The first detection unit has a light source that generates light, an optical system that forms an optical path for irradiating the die or the substrate with the light generated by the light source, and a camera that receives reflected light of the light irradiated by the optical system. The first detection unit has a switching mechanism that switches light irradiated by the optical system on the die or the substrate between first light and second light having a wavelength different from that of the first light.

Description

Bonding device and bonding method

[0001] The present disclosure relates to a bonding device and a bonding method.

[0002] The bonding device described in Patent Document 1 bonds a chip to a substrate. This bonding device has a first imaging unit, a second imaging unit, and a third imaging unit. The first imaging unit images the alignment marks on the bonding surface of the chip before bonding the chip to the substrate. The second imaging unit images the alignment marks on the bonding surface of the substrate. The third imaging unit simultaneously images the alignment marks on the respective bonding surfaces of the chip and the substrate after bonding the chip to the substrate.

[0003] Japanese Patent Application Laid-Open No. 2024-160867

[0004] One embodiment of the present disclosure provides a technique capable of reducing the number of detection units composed of a light source, an optical system, and a camera.

[0005] The bonding device according to one embodiment of the present disclosure aligns the die and the substrate based on the relative positions of the first mark of the die and the second mark of the substrate, and bonds the die and the substrate. The bonding device includes a first holding unit that holds a carrier on which the die is mounted, a second holding unit that holds the substrate, a transfer unit that transfers the die from the carrier held by the first holding unit to the substrate held by the second holding unit, and a first detection unit that detects at least one of the first mark and the second mark. The first detection unit includes a light source that generates light, an optical system that forms an optical path for irradiating the light generated by the light source onto the die or the substrate, and a camera that receives the reflected light of the light irradiated by the optical system. The first detection unit has a switching mechanism that switches the light irradiated by the optical system onto the die or the substrate between first light and second light having a wavelength different from that of the first light.

[0006] According to one embodiment of the present disclosure, the number of detection units composed of a light source, an optical system, and a camera can be reduced.

[0007] Figure 1 is a plan view showing an example of a bonding system. Figure 2 is a cross-sectional view showing an example of a carrier before the die is picked up. Figure 3 is a cross-sectional view showing an example of a substrate before the die is bonded. Figure 4 is a cross-sectional view showing an example of a substrate after the die has been bonded. Figure 5 is a flowchart showing an example of the operation of the bonding system. Figure 6 is a perspective view showing an example of a bonding apparatus. Figure 7 is a perspective view showing an example of die transport in the bonding apparatus. Figure 8 is a plan view showing an example of die-substrate alignment. Figure 9 is a perspective view showing an example of alignment between the first and second detection units. Figure 10 shows an example of detecting the second mark before bonding the die and substrate. Figure 11 shows an example of detecting the first and second marks after bonding the die and substrate. Figure 12 shows an example of detecting the first mark before bonding the die and substrate. Figure 13 shows a modified example of the first detection unit.

[0008] Embodiments of this disclosure will be described below with reference to the drawings. In each drawing, identical or similar components are denoted by the same reference numerals, and their descriptions may be omitted. In this specification, the X-axis, Y-axis, and Z-axis directions are perpendicular to each other. The X-axis and Y-axis directions are horizontal, and the Z-axis direction is vertical.

[0009] The X-axis direction includes the positive X-axis direction and the negative X-axis direction, which is the opposite direction to the positive X-axis direction. The Y-axis direction includes the positive Y-axis direction and the negative Y-axis direction, which is the opposite direction to the positive Y-axis direction. The Z-axis direction includes the positive Z-axis direction and the negative Z-axis direction, which is the opposite direction to the positive Z-axis direction. The positive Z-axis direction is upward, and the negative Z-axis direction is downward.

[0010] A bonding system 1 according to one embodiment will be described with reference to Figures 1 to 4. The bonding system 1 bonds the die D and the substrate W with the bonding surface Da of the die D facing the bonding surface Wa of the substrate W. For example, the bonding system 1 repeatedly bonds the die D and the substrate W, bonding multiple dies D to the substrate W one by one in sequence.

[0011] As shown in Figure 2, the carrier E holds multiple dies D. The carrier E holds each die D from below, with the bonding surface Da of each die D facing upward. This allows for activation and hydrophilization of the bonding surface Da of each die D. The carrier E has a carrier substrate E1 and a resin film E2 provided on the surface of the carrier substrate E1 facing the die D. The non-bonding surface Db of the die D is in contact with the resin film E2.

[0012] Carrier E holds multiple dies D on a resin film E2. Carrier E can, for example, electrostatically attract the dies D. Alternatively, by pressing the dies D against the resin film E2, the resin film E2 can be deformed to allow gas to escape from between the dies D and the resin film E2, making it possible to vacuum-adsorb the dies D to the resin film E2. Carrier E may also attract the dies D by intermolecular forces.

[0013] The carrier substrate E1 may be conductive or insulating. A first through-hole E3 is formed in the carrier substrate E1, penetrating the substrate in the thickness direction. The die D can be detached from the carrier E by supplying gas to the first through-hole E3 or by inserting a pin (not shown) into the first through-hole E3. The number and arrangement of the first through-holes E3 are not particularly limited. One or more first through-holes E3 may be formed for each die D.

[0014] The resin film E2 is preferably composed of a flexible material, specifically a material with an elastic modulus of 2 GPa or less, more preferably 0.5 GPa or less. From the viewpoint of durability when modifying the bonding surface Da of the die D, the resin film E2 is preferably composed of, for example, polyimide or EVA (ethylene vinyl acetate copolymer). The thickness of the resin film E2 is, for example, 10 μm. In this embodiment, the resin film E2 is a single layer, but it may be a multi-layer structure. For example, the resin film E2 may have a polyolefin layer and an acrylic adhesive layer.

[0015] Note that carrier E may have a configuration other than that shown in Figure 2. For example, carrier E may be a tape frame. The tape frame has a frame and a tape that covers the opening of the frame, and the die D is mounted on the tape. The tape frame holds the die D from below with the bonding surface Da of the die D facing upward. This allows for activation and hydrophilization of the bonding surface Da. The non-bonding surface Db of the die D is in contact with the tape.

[0016] As shown in Figure 3, the substrate W comprises a semiconductor substrate W1 and a plurality of devices W2 formed on the semiconductor substrate W1. In this embodiment, the semiconductor substrate W1 is a silicon wafer, but it may also be a compound semiconductor wafer. A glass substrate may be used instead of the semiconductor substrate W1. The substrate W has a bonding surface Wa and a non-bonding surface facing the opposite direction from the bonding surface Wa. The bonding surface Wa and non-bonding surface of the substrate W are circular, but may also be rectangular. The substrate W has a plurality of devices W2 on the bonding surface Wa. The plurality of devices W2 are separated by a plurality of streets that are orthogonal to each other. Each device W2 includes an electronic circuit. As shown in Figure 4, a die D is electrically connected to each device W2. Then, the substrate W is cut along the streets to separate each device W2 into individual pieces to obtain a semiconductor device. The semiconductor device includes the devices W2 and the die D.

[0017] Die D is a semiconductor substrate on which multiple devices, separate from device W2, are formed, and each device is separated into individual pieces. A glass substrate may be used instead of a semiconductor substrate. Die D has a bonding surface Da and a non-bonding surface Db facing the opposite direction from bonding surface Da. The non-bonding surface Db of die D does not need to be a surface that is not bonded to the substrate W, and may be bonded to another die (not shown). Die D has a device on bonding surface Da. The electronic circuit of the device on die D and the electronic circuit of device W2 on the substrate W are electrically connected. The type and number of dies D electrically connected to a single device W2 are not particularly limited. Although not shown, multiple dies D may be electrically connected to a single device W2.

[0018] As shown in Figure 1, the bonding system 1 includes a control circuit 9. The control circuit 9 is, for example, a computer. The control circuit 9 includes an arithmetic unit 91, such as a CPU (Central Processing Unit), and a storage unit 92, such as memory. The storage unit 92 stores programs that control various processes executed in the bonding system 1.

[0019] The control circuit 9 controls the operation of the junction system 1 by causing the arithmetic unit 91 to execute a program stored in the memory unit 92. A lower-level control circuit may be provided for each device constituting the junction system 1 to control the operation of that device, and a higher-level control circuit may be provided to comprehensively control multiple lower-level control circuits. The control circuit 9 may be composed of multiple lower-level control circuits and a higher-level control circuit.

[0020] The control circuit 9 includes electronic circuits such as a CPU, GPU (Graphics Processing Unit), FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit). The control circuit 9 performs the various control operations described in this specification by executing instruction codes stored in a storage medium such as memory, or by being designed as a circuit for a special application.

[0021] As shown in Figure 1, the joining system 1 comprises an input / output station 2, a first processing station 3, and a second processing station 5. The input / output station 2, the first processing station 3, and the second processing station 5 are arranged in this order, in a line from the negative X-axis direction to the positive X-axis direction. Although not shown, there may be multiple second processing stations 5, and multiple second processing stations 5 may be arranged in a line from the negative X-axis direction to the positive X-axis direction.

[0022] The loading / unloading station 2 is equipped with a mounting table 20. The mounting table 20 is used to place the first cassette C1, the second cassette C2, the third cassette C3, and the fourth cassette C4. The first cassette C1 contains the substrate W before the die D is bonded. The second cassette C2 contains the substrate W after the die D has been bonded (i.e., the laminated substrate DW composed of the substrate W and the die D). The third cassette C3 contains the carrier E before the die D is picked up. The fourth cassette C4 contains the carrier E after the die D has been picked up.

[0023] The loading / unloading station 2 comprises a first transport area 21 and a first transport device 22. The first transport area 21 is adjacent to the mounting table 20. The first transport area 21 extends in the Y-axis direction. The first transport device 22 has a transport arm. The transport arm holds and transports the substrate W and carrier E in the first transport area 21. There may be one or more transport arms. A transport arm for the substrate W and a transport arm for the carrier E may be provided separately. The first transport device 22 has a drive unit (not shown) for moving or rotating the transport arm. The transport arm is capable of moving horizontally (in both the X-axis and Y-axis directions) and vertically (in the Z-axis direction), and rotating about the vertical axis.

[0024] The first processing station 3 includes a first storage device 30. The first storage device 30 is adjacent to the first transport area 21. The first storage device 30 is positioned on the opposite side of the loading table 20 with respect to the first transport area 21. The first storage device 30 temporarily stores the substrates W and carriers E. The first storage device 30 has a plurality of stages arranged vertically. Each stage places the substrates W and carriers E on it. The stage for the substrates W and the stage for the carriers E may be provided separately.

[0025] The first processing station 3 comprises a second transport area 31 and a second transport device 32. The second transport area 31 is adjacent to the first storage device 30 and extends from the first storage device 30 in the positive X-axis direction. The second transport device 32 has a transport arm. The transport arm holds and transports the substrate W and carrier E in the second transport area 31. There may be one or more transport arms. A transport arm for the substrate W and a transport arm for the carrier E may be provided separately. The second transport device 32 has a drive unit (not shown) for moving or rotating the transport arm. The transport arm is capable of moving horizontally (in both the X-axis and Y-axis directions) and vertically (in the Z-axis direction), and rotating about the vertical axis.

[0026] The first processing station 3 comprises a first activation device 33, a first hydrophilization device 34, a second activation device 35, and a second hydrophilization device 36. The first activation device 33, the first hydrophilization device 34, the second activation device 35, and the second hydrophilization device 36 are adjacent to the second transport area 31 and are provided on the positive or negative Y-axis side of the second transport area 31.

[0027] The first activation device 33 activates the bonding surface Da of the die D while the die D is held by the carrier E. The first activation device 33 is, for example, a plasma processing device. In the first activation device 33, for example, oxygen gas, which is the processing gas, is excited and plasma-generated under reduced pressure and then ionized. The bonding surface Da of the die D is activated when oxygen ions are irradiated onto it. The processing gas is not limited to oxygen gas, and may be nitrogen gas, for example.

[0028] The first hydrophilization device 34 hydrophilizes the bonding surface Da of the die D while the die D is held in place by the carrier E. For example, the first hydrophilization device 34 supplies pure water (e.g., deionized water) onto the die D while rotating the carrier E held in the spin chuck. The pure water imparts OH groups to the bonding surface Da of the die D, which has been previously activated. The die D and the substrate W can then be bonded using the hydrogen bonds between the OH groups.

[0029] The second activation device 35 activates the bonding surface Wa of the substrate W. The second activation device 35 is, for example, a plasma processing device. In the second activation device 35, for example, oxygen gas, which is the processing gas, is excited and plasma-generated under reduced pressure and then ionized. The bonding surface Wa of the substrate W is activated when oxygen ions are irradiated onto it. The processing gas is not limited to oxygen gas, and may be nitrogen gas, for example.

[0030] The second hydrophilization device 36 hydrophilizes the bonding surface Wa of the substrate W. For example, the second hydrophilization device 36 rotates the substrate W, which is held in a spin chuck, while supplying pure water (e.g., deionized water) onto the substrate W. The pure water imparts OH groups to the bonding surface Wa of the substrate W, which has been previously activated. The die D and the substrate W can be bonded by utilizing the hydrogen bonds between the OH groups.

[0031] The second processing station 5 includes a second storage device 50. The second storage device 50 is adjacent to the second transport area 31. The second storage device 50 is positioned on the opposite side from the first storage device 30 with respect to the second transport area 31. The second storage device 50 temporarily stores the substrates W and carriers E. The second storage device 50 has a plurality of stages arranged vertically. Each stage holds at least one of the substrates W and carriers E. The stage for the substrates W and the stage for the carriers E may be provided separately.

[0032] The second processing station 5 comprises a third transport area 51 and a third transport device 52. The third transport area 51 is adjacent to the second storage device 50 and extends from the second storage device 50 in the positive X-axis direction. The third transport device 52 has a transport arm. The transport arm holds and transports the substrate W and carrier E in the third transport area 51. There may be one or more transport arms. A transport arm for the substrate W and a transport arm for the carrier E may be provided separately. The third transport device 52 has a drive unit (not shown) for moving or rotating the transport arm. The transport arm is capable of moving horizontally (in both the X-axis and Y-axis directions) and vertically (in the Z-axis direction), and rotating about the vertical axis.

[0033] The second processing station 5 is equipped with a bonding device 60. The bonding device 60 is adjacent to the third transport area 51 and is provided on the positive or negative Y-axis side of the third transport area 51. The bonding device 60 separates the die D from the carrier E and bonds the die D and the substrate W with the bonding surface Da of the separated die D facing the bonding surface Wa of the substrate W. Details of the bonding device 60 will be described later.

[0034] Next, with reference to Figure 5, a joining method according to one embodiment will be described. Steps S101 to S105 shown in Figure 5 are carried out under the control of the control circuit 9. First, the first transport device 22 takes the carrier E from the third cassette C3 and transports it to the first storage device 30. Next, the second transport device 32 takes the carrier E from the first storage device 30 and transports it to the first activation device 33.

[0035] Next, the first activation device 33 activates the bonding surface Da of the die D while the die D is held by the carrier E (step S101). After that, the second transport device 32 removes the carrier E from the first activation device 33 and transports it to the first hydrophilization device 34.

[0036] Next, the first hydrophilization device 34 hydrophilizes the bonding surface Da of the die D while the die D is held by the carrier E (step S102). Then, the second conveying device 32 removes the carrier E from the first hydrophilization device 34 and conveys it to the second storage device 50. Subsequently, the third conveying device 52 removes the carrier E from the second storage device 50 and conveys it to the bonding device 60.

[0037] In parallel with the above steps S101 to S102, the following steps S103 to S104 are performed. First, the first transport device 22 takes the substrate W from the first cassette C1 and transports it to the first storage device 30. Next, the second transport device 32 takes the substrate W from the first storage device 30 and transports it to the second activation device 35.

[0038] Next, the second activation device 35 activates the bonding surface Wa of the substrate W (step S103). After that, the second transport device 32 removes the substrate W from the second activation device 35 and transports it to the second hydrophilization device 36.

[0039] Next, the second hydrophilization device 36 hydrophilizes the bonding surface Wa of the substrate W (step S104). Then, the second transport device 32 removes the substrate W from the second hydrophilization device 36 and transports it to the second storage device 50. Subsequently, the third transport device 52 removes the substrate W from the second storage device 50 and transports it to the bonding device 60.

[0040] Next, the bonding apparatus 60 separates the die D from the carrier E, and then faces the bonding surface Da of the separated die D toward the bonding surface Wa of the substrate W, thereby bonding the die D to the substrate W (step S105). Note that if multiple dies D are electrically connected to a single device W2, the bonding of the die D to the substrate W is performed separately for each type of die D.

[0041] After the die D is bonded, the substrate W is transported to the second cassette C2. First, the third transport device 52 removes the substrate W after the die D has been bonded from the bonding device 60 and transports it to the second storage device 50. Next, the second transport device 32 removes the substrate W after the die D has been bonded from the second storage device 50 and transports it to the first storage device 30. Finally, the first transport device 22 removes the substrate W after the die D has been bonded from the first storage device 30 and stores it in the second cassette C2.

[0042] After die D is separated, carrier E is stored in the fourth cassette C4. First, the third transport device 52 removes carrier E after die D has been separated from the joining device 60 and transports it to the second storage device 50. Next, the second transport device 32 removes carrier E after die D has been separated from the second storage device 50 and transports it to the first storage device 30. Finally, the first transport device 22 removes carrier E after die D has been separated from the first storage device 30 and stores it in the fourth cassette C4.

[0043] In this embodiment, the bonding method between the die D and the substrate W is surface-activated bonding (SAB), but atomic diffusion bonding (ADB) may also be used.

[0044] Referring to FIG. 6, an example of the bonding apparatus 60 will be described. Note that a third transfer region 51 is arranged on the positive Y-axis side of the illustrated bonding apparatus 60. The bonding apparatus 60 has a gantry 100. The gantry 100 has a first gantry 101 and a second gantry 102. The first gantry 101 and the second gantry 102 are arranged side by side in the horizontal direction (X-axis direction). The first gantry 101 and the second gantry 102 may be provided integrally. The first gantry 101 mainly supports the first holding unit 110 and the pickup unit 140. On the other hand, the second gantry 102 mainly supports the second holding unit 120 and the mount unit 150.

[0045] The bonding apparatus 60 includes a first holding unit 110. The first holding unit 110 holds the carrier E. For example, the first holding unit 110 holds the carrier substrate E1 from below with the resin film E2 of the carrier E facing upward. The first holding unit 110 is, for example, a vacuum suction chuck. The first holding unit 110 holds the carrier E horizontally from below with the bonding surface Da of the die D mounted on the carrier E facing upward. The bonding apparatus 60 may have a third moving mechanism 111. The third moving mechanism 111 moves the first holding unit 110 in the X-axis direction and the Y-axis direction. The third moving mechanism 111 includes, for example, a linear motor.

[0046] The bonding apparatus 60 includes a second holding unit 120. The second holding unit 120 holds the substrate W. For example, the second holding unit 120 holds the substrate W from above with the bonding surface Wa of the substrate W facing downward. The bonding apparatus 60 may have a fourth moving mechanism 121. The fourth moving mechanism 121 moves the second holding unit 120 in the Y-axis direction. The fourth moving mechanism 121 has, for example, a Y-axis guide 122, a Y-axis drive unit 123, and a support column 124. A pair of Y-axis guides 122 are provided sandwiching the second holding unit 120. The Y-axis drive unit 123 moves the second holding unit 120 along the pair of Y-axis guides 122. The Y-axis drive unit 123 includes, for example, a linear motor. The support column 124 is fixed to the upper surface of the second gantry 102 and supports the Y-axis guide 122 and the Y-axis drive unit 123.

[0047] The bonding device 60 includes a transfer unit 130. The transfer unit 130 transfers the die D from the carrier E held by the first holding unit 110 to the substrate W held by the second holding unit 120. The transfer unit 130 has, for example, a pickup unit 140 and a mounting unit 150. By sharing the roles of the pickup unit 140 and the mounting unit 150 as shown in FIG. 7, the transfer efficiency of the die D can be improved.

[0048] The pickup unit 140 picks up and transfers the die D from the carrier E held by the first holding unit 110. The pickup unit 140 has a first suction head 141 and a first moving mechanism 142. The first suction head 141 sucks the die D. The first moving mechanism 142 moves the first suction head 141.

[0049] The first suction head 141 sucks, for example, the bonding surface Da of the die D. The first suction head 141 may contact the bonding surface Da of the die D and, for example, vacuum-suck the die D. Note that the first suction head 141 may suck the die D in a non-contact manner so as not to contaminate the bonding surface Da of the die D.

[0050] For example, the first suction head 141 has a suction nozzle and an injection nozzle (not shown) on the surface facing the die D (for example, the lower surface). The suction nozzle sucks gas, and the injection nozzle injects gas. The first suction head 141 can suck the die D in a non-contact manner by the injection pressure (positive pressure) and the suction pressure (negative pressure) of the gas. Note that the suction method is not particularly limited. Examples of non-contact suction methods include the Bernoulli method or the ultrasonic method.

[0051] The first moving mechanism 142 moves the die D together with the first suction head 141. The first moving mechanism 142 includes, for example, a holder 143, an arm 144, an X-axis guide 145, an X-axis drive unit 146, and a support column 147. The holder 143 supports the first suction head 141 and moves in the X-axis direction along the X-axis guide 145 together with the arm 144. The X-axis drive unit 146 moves the first suction head 141 in the X-axis direction. More specifically, the X-axis drive unit 146 moves the holder 143 and the first suction head 141 in the X-axis direction together with the arm 144. The X-axis drive unit 146 includes, for example, a linear motor. The support column 147 is fixed to the upper surface of the first frame 101 and supports the X-axis guide 145 and the X-axis drive unit 146.

[0052] The first moving mechanism 142 may further include at least one of a Y-axis drive unit and a Z-axis drive unit. The Y-axis drive unit moves the first suction head 141 in the Y-axis direction. The Z-axis drive unit moves the first suction head 141 in the Z-axis direction. The Y-axis drive unit and the Z-axis drive unit include, for example, a linear motor. The first moving mechanism 142 may further include a rotation drive unit. The rotation drive unit rotates the first suction head 141 around the Z-axis. The rotation drive unit includes, for example, a rotary motor.

[0053] The mounting unit 150 receives the die D from the pickup unit 140 and mounts it onto the substrate W held by the second holding unit 120. The mounting unit 150 has a second suction head 151 and a second moving mechanism 152. The second suction head 151 picks up the die D from the opposite side from the first suction head 141. The second moving mechanism 152 moves the second suction head 151.

[0054] The second suction head 151 adsorbs, for example, the non-bonding surface Db of the die D. Since it is not a problem if the non-bonding surface Db is dirty, the second suction head 151 may come into contact with the die D. This can improve the suction force and suppress misalignment. The second suction head 151 adsorbs the die D, for example, using vacuum suction.

[0055] The second moving mechanism 152 moves the die D together with the second suction head 151. The second moving mechanism 152 includes, for example, a holder 153, a movable stage 154, an X-axis guide 155, an X-axis drive unit 156, a Y-axis guide 157, and a Y-axis drive unit 158. The holder 153 supports the second suction head 151 and moves along the X-axis guide 155 and Y-axis guide 157 in the X-axis and Y-axis directions together with the movable stage 154. The Y-axis guide 157 is provided in a pair on either side of the X-axis guide 155 and supports the X-axis guide 155 so that it can move in the Y-axis direction. The Y-axis guide 157 is fixed to the upper surface of the second frame 102. The X-axis drive unit 156 moves the second suction head 151 in the X-axis direction. More specifically, the X-axis drive unit 156 moves the holder 153 and the second suction head 151 in the X-axis direction together with the movable stage 154. The X-axis drive unit 156 includes, for example, a linear motor. The Y-axis drive unit 158 ​​moves the second suction head 151 in the Y-axis direction. More specifically, the Y-axis drive unit 158 ​​moves the movable stage 154, the holder 153, and the second suction head 151 in the Y-axis direction together with the X-axis guide 155. The Y-axis drive unit 158 ​​includes, for example, a linear motor.

[0056] The second moving mechanism 152 may further include a Z-axis drive unit. The Z-axis drive unit moves the second suction head 151 in the Z-axis direction. The Z-axis drive unit includes, for example, a linear motor. The second moving mechanism 152 may further include a rotation drive unit. The rotation drive unit rotates the second suction head 151 around the Z-axis. The rotation drive unit includes, for example, a rotary motor.

[0057] The bonding device 60 preferably includes a pressing section 160. The pressing section 160 assists the pickup of the die D by the pickup section 140. The pressing section 160 presses the resin film E2, for example, by supplying gas to the first through-hole E3 of the carrier substrate E1, or by inserting a pin (not shown) into the first through-hole E3. The direction of pressing is the direction in which the die D is picked up (for example, the positive Z-axis direction). The resin film E2 can be deformed only in the vicinity of one of the multiple dies D, a wedge-shaped gap can be formed between the resin film E2 and the die D, and the die D can be smoothly picked up from the resin film E2. The pressing section 160 is provided inside or below the first holding section 110.

[0058] The bonding device 60 includes a control circuit 190. The control circuit 190 may be part of the control circuit 9. The control circuit 190 includes, for example, an arithmetic unit such as a CPU and a storage unit such as memory. The storage unit stores a program that controls various processes performed in the bonding device 60. The control circuit 190 controls the operation of the bonding system 1 by causing the arithmetic unit to execute the program stored in the storage unit.

[0059] Referring to Figure 8, an example of alignment between die D and substrate W will be described. Die D has a first mark Dm, and substrate W has a second mark Wm. The bonding apparatus 60 aligns die D and substrate W based on the relative positions of the first mark Dm and the second mark Wm, and then bonds die D and substrate W.

[0060] The first mark Dm is formed, for example, on the bonding surface Da of die D. However, the first mark Dm may also be formed on the non-bonding surface Db of die D or inside it. The number and shape of the first marks Dm are not limited to those shown in Figure 8. The first mark Dm may be a dedicated mark or may be part of the electronic circuit of die D.

[0061] The second mark Wm is formed, for example, on the bonding surface Wa of the substrate W. However, the second mark Wm may also be formed on the non-bonding surface Wb of the substrate W or inside it. The number and shape of the second marks Wm are not limited to those shown in Figure 8. The second mark Wm may be a dedicated mark or may be part of the electronic circuit of the device W2.

[0062] As shown in Figure 7, the bonding apparatus 60 includes a first detection unit 170 and a second detection unit 180. The first detection unit 170 and the second detection unit 180 each detect at least one of the first mark Dm and the second mark Wm. Note that the detection of the first mark Dm and the second mark Wm does not have to be performed each time the die D and the substrate W are bonded, but may be performed periodically.

[0063] The first detection unit 170 is provided, for example, below the second holding unit 120 and is moved horizontally together with the second suction head 151 by the second moving mechanism 152. Before the die D and the substrate W are joined, the first detection unit 170 images the joining surface Wa of the substrate W held by the second holding unit 120 and images the second mark Wm.

[0064] The second detection unit 180 is provided, for example, above the second suction head 151 and is fixed to the second holding unit 120. Before the bonding of the die D and the substrate W, the second detection unit 180 images the bonding surface Da of the die D that the second suction head 151 is adsorbed onto, and images the first mark Dm.

[0065] Referring to Figure 9, an example of alignment between the first detection unit 170 and the second detection unit 180 will be described. By simultaneously imaging the same reference mark Sm with the first detection unit 170 and the second detection unit 180, the control circuit 190 can detect the reference position of the relative position of the first detection unit 170 and the second detection unit 180. Note that imaging of the reference mark Sm does not have to be performed each time the die D and the substrate W are joined, but may be performed periodically.

[0066] An example of the first detection unit 170 will be described with reference to Figures 10 to 12. Note that the second detection unit 180 is configured similarly to the first detection unit 170, so its description will be omitted. However, the second detection unit 180 may have a different configuration from the first detection unit 170, or it may have a configuration similar to that of the conventional unit.

[0067] The first detection unit 170 includes, for example, a light source 210, an optical system 220, and a camera 230, as shown in Figures 10 to 12. The light source 210 generates light. The optical system 220 forms an optical path 221 that irradiates the die D or substrate W with the light generated by the light source 210. The camera 230 receives the reflected light from the light irradiated by the optical system 220.

[0068] The light source 210 is, for example, a halogen lamp. A halogen lamp generates light with a desired intensity across the visible and near-infrared regions. The wavelength of the light generated by the halogen lamp is, for example, 400 nm to 1800 nm. The light source 210 is not limited to a halogen lamp and may be an LED (Light Emitting Diode), etc. The light source 210 may have multiple light sources that generate light in different wavelength ranges from each other.

[0069] Visible light does not penetrate the die D or substrate W. Therefore, visible light is suitable when the first mark Dm or the second mark Wm is exposed as viewed from the light source 210 and the camera 230. On the other hand, near-infrared light penetrates the die D or substrate W. Therefore, infrared light is suitable when the first mark Dm or the second mark Wm is hidden behind or inside the die D or substrate W as viewed from the light source 210 and the camera 230.

[0070] The light source 210 generates light in which, for example, a first light and a second light having a different wavelength from the first light are mixed. An example of the first light is visible light, and an example of the second light is infrared light.

[0071] The optical system 220 may have a beam splitter 222 in the middle of the optical path 221. The beam splitter 222, for example, reflects light from the light source 210 toward the die D or substrate W, and transmits light from the die D or substrate W toward the camera 230. The arrangement of the light source 210 and the camera 230 may be reversed. In other words, the beam splitter 222 may transmit light from the light source 210 toward the die D or substrate W, and reflect light from the die D or substrate W toward the camera 230.

[0072] The optical system 220 may further include various lenses.

[0073] The camera 230 has a light-receiving surface 231. The light-receiving surface 231 is composed of a plurality of light-receiving elements. The light-receiving elements are, for example, CCDs (Charge Coupled Devices) or CMOS (Complementary Metal Oxide Semiconductors). Each light-receiving element generates an electrical signal corresponding to the intensity of the light it receives. Each light-receiving element is not particularly limited as long as it can receive both the first light and the second light. The camera 230 transmits a signal indicating the captured image to the control circuit 190. The control circuit 190 processes the image captured by the camera 230 and detects at least one of the first mark Dm and the second mark Wm.

[0074] The first detection unit 170 has a switching mechanism 240. The switching mechanism 240 switches the light that the optical system 220 irradiates onto the die D or substrate W between a first light L1 and a second light having a different wavelength from the first light. This reduces the number of detection units compared to the case where a detection unit consisting of a light source 210, an optical system 220, and a camera 230 is prepared separately for each wavelength of light. Therefore, the installation space can be reduced. In addition, errors between detection units can be eliminated.

[0075] The switching mechanism 240 includes, for example, a first filter 241, a second filter 242, and a changing mechanism 243. The first filter 241 transmits the first light and blocks the second light in the middle of the optical path 221. On the other hand, the second filter 242 blocks the first light and transmits the second light in the middle of the optical path 221. The changing mechanism 243 changes the state of the optical path 221 between a first state and a second state. The first state is, as shown in Figure 10, when the first filter 241 is inserted into the optical path 221 and the second filter 242 is retracted from the optical path 221. The second state is, as shown in Figures 11 and 12, when the first filter 241 is retracted from the optical path 221 and the second filter 242 is inserted into the optical path 221. The modification mechanism 243 has actuators such as motors that move or rotate the first filter 241 and the second filter 242.

[0076] The first filter 241 is a so-called bandpass filter that selectively transmits light in the first wavelength band. The first filter 241 blocks light with wavelengths shorter than the first wavelength band and light with wavelengths longer than the first wavelength band. Preferably, the width of the wavelength band with a transmittance of 50% or more is 200 nm or less. If the width of the above wavelength band is 200 nm or less, the wavelength of the light can be sufficiently narrowed before it hits the die D or substrate W, thin-film interference can be suppressed, and a clear image can be captured. Thin-film interference is caused, for example, by the device of the die D or substrate W. The narrower the above wavelength band, the better, but it may be 5 nm or more.

[0077] The second filter 242 is a so-called bandpass filter that selectively transmits light in a second wavelength band different from the first wavelength band. The second filter 242 blocks light with wavelengths shorter than the second wavelength band and light with wavelengths longer than the second wavelength band. Preferably, the width of the wavelength band with a transmittance of 50% or more is 200 nm or less. If the width of the above wavelength band is 200 nm or less, the wavelength of the light can be sufficiently narrowed before it hits the die D or substrate W, thin film interference can be suppressed, and a clear image can be captured. The width of the above wavelength band is preferable as it is narrower, but it may be 5 nm or more.

[0078] The first filter 241 and the second filter 242 are interchangeably arranged between the light source 210 and the beam splitter 222, for example, as shown in Figures 10 to 12. Although not shown, the first filter 241 and the second filter 242 may also be interchangeably arranged between the beam splitter 222 and the die D or substrate W. In any case, the wavelength of light can be narrowed before it hits the die D or substrate W, thin-film interference can be reduced, and a clear image can be captured.

[0079] As shown in Figure 10, the control circuit 190 controls the optical system 220 to irradiate the substrate W held by the second holding unit 120 with first light, and the camera 230 to image the second mark Wm, before bonding the die D and the substrate W. Since the second mark Wm is exposed from the perspective of the light source 210 and the camera 230, visible light is suitable for imaging the second mark Wm. According to this embodiment, the first filter 241 narrows the wavelength of light, so thin-film interference can be suppressed and a clear image of the second mark Wm can be captured. When bonding the die D and the substrate W, the control circuit 190 uses the image of the second mark Wm that was captured in advance to align the die D and the substrate W.

[0080] As shown in Figure 11, the control circuit 190 controls the optical system 220 to irradiate the substrate W and die D, held by the second holding unit 120, with second light after bonding the die D and the substrate W, and controls the camera 230 to simultaneously capture images of the first mark Dm and the second mark Wm. As seen from the light source 210 and the camera 230, the first mark Dm and the second mark Wm are hidden behind the die D, so infrared light is suitable for simultaneously capturing images of the first mark Dm and the second mark Wm. According to this embodiment, the second filter 242 narrows the wavelength of light, so thin-film interference can be suppressed, and clear images of the first mark Dm and the second mark Wm can be captured. Based on the images of the first mark Dm and the second mark Wm captured after the nth bonding, the control circuit 190 aligns the die D and the substrate W when performing bonding for the (n+1)th time and beyond.

[0081] As shown in Figure 12, the control circuit 190 controls the optical system 220 to irradiate light onto the die D held by the pickup unit 140, and the camera 230 to image the first mark Dm. Specifically, the control circuit 190 controls the optical system 220 to irradiate light onto the die D that the first suction head 141 is adsorbing, and the camera 230 to image the first mark Dm. As seen from the light source 210 and the camera 230, the first mark Dm is hidden behind the die D, so infrared light is suitable for imaging the first mark Dm. According to this embodiment, the second filter 242 narrows the wavelength of light, so thin-film interference can be suppressed, and a clear image of the first mark Dm can be captured. When the control circuit 190 transfers the die D from the first suction head 141 to the second suction head 151, it uses a previously captured image of the first mark Dm to align the die D and the second suction head 151.

[0082] A modified version of the first detection unit 170 will be described with reference to Figure 13. The differences will be mainly explained below. The light source 210 may separately have a first light source 211 that generates first light and a second light source 212 that generates second light. If the wavelength range of the light generated by the first light source 211 is wide, a first filter 241 may be provided near the first light source 211. Also, if the wavelength range of the light generated by the second light source 212 is wide, a second filter 242 may be provided near the second light source 212.

[0083] The optical system 220 includes, for example, a dichroic mirror 223 in addition to the beam splitter 222. The dichroic mirror 223 transmits, for example, the first light generated by the first light source 211 toward the beam splitter 222, and reflects the second light generated by the second light source 212 toward the beam splitter 222.

[0084] Note that the arrangement of the first light source 211 and the second light source 212 may be reversed. In other words, the dichroic mirror 223 may reflect the first light generated by the first light source 211 toward the beam splitter 222, and transmit the second light generated by the second light source 212 toward the beam splitter 222.

[0085] The switching mechanism 240 includes an electrical circuit 244 that operates the first light source 211 and the second light source 212 individually. The electrical circuit 244 includes a switch, etc. The switch opens and closes the power line. According to this modified example, the number of detection units can be reduced compared to the case in which a detection unit consisting of a light source 210, an optical system 220, and a camera 230 is prepared separately for each wavelength of light, as in the above embodiment. Therefore, the installation space can be reduced. In addition, errors between detection units can be eliminated.

[0086] While embodiments of the joining apparatus and joining method described above have been explained, this disclosure is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These also naturally fall within the technical scope of this disclosure.

[0087] This application claims priority based on Japanese Patent Application No. 2024-232858, filed with the Japan Patent Office on December 27, 2024, and the entire contents of Japanese Patent Application No. 2024-232858 are incorporated herein by reference.

[0088] 60 Bonding device 110 First holding unit 120 Second holding unit 130 Transport unit 170 First detection unit 210 Light source 220 Optical system 230 Camera 240 Switching mechanism D Die Dm First mark E Carrier W Substrate Wm Second mark

Claims

1. A bonding apparatus for aligning a die and a substrate based on the relative positions of a first mark on a die and a second mark on a substrate, and bonding the die and the substrate, comprising: a first holding unit for holding a carrier on which the die is mounted; a second holding unit for holding the substrate; a transport unit for transporting the die from the carrier held by the first holding unit to the substrate held by the second holding unit; and a first detection unit for detecting at least one of the first mark and the second mark, wherein the first detection unit comprises a light source for generating light, an optical system for forming an optical path for irradiating the die or the substrate with the light generated by the light source, and a camera for receiving reflected light from the light irradiated by the optical system, and the first detection unit has a switching mechanism for switching the light irradiated by the optical system onto the die or the substrate between a first light and a second light having a different wavelength from the first light.

2. The bonding apparatus according to claim 1, wherein the light source generates light in which the first light and the second light are mixed, and the switching mechanism includes a first filter that transmits the first light and blocks the second light in the middle of the optical path, a second filter that blocks the first light and transmits the second light in the middle of the optical path, and a changing mechanism that changes the state of the optical path between a first state in which the first filter is inserted into the optical path and the second filter is retracted from the optical path, and a second state in which the first filter is retracted from the optical path and the second filter is inserted into the optical path.

3. The bonding device according to claim 1, wherein the light source separately comprises a first light source for generating the first light and a second light source for generating the second light, and the switching mechanism includes an electrical circuit for operating the first light source and the second light source individually.

4. The bonding apparatus according to claim 1, comprising a control circuit for controlling the transport unit and the first detection unit, wherein the die has a first mark on the bonding surface with the substrate, and the substrate has a second mark on the bonding surface with the die, and the control circuit controls the switching mechanism to irradiate the substrate held by the second holding unit with a first light before bonding the die and the substrate, and controls the camera to image the second mark, and controls the switching mechanism to irradiate the substrate held by the second holding unit with a second light after bonding the die and the substrate, and controls the camera to simultaneously image the first mark and the second mark.

5. The bonding apparatus according to claim 4, wherein the transport unit includes a pickup unit that picks up the die from the carrier held by the first holding unit and transports it, and a mounting unit that receives the die from the pickup unit and mounts it on the substrate held by the second holding unit, and the control circuit controls the switching mechanism so that the optical system irradiates the die held by the pickup unit with the second light, and controls the camera to capture an image of the first mark.

6. The bonding apparatus according to claim 5, wherein the pickup unit has a first suction head for adsorbing the die and a first moving mechanism for moving the first suction head, the mounting unit has a second suction head for adsorbing the die from the opposite side of the first suction head and a second moving mechanism for moving the second suction head, and the control circuit controls the switching mechanism so that the optical system irradiates the die adsorbed by the first suction head with the second light, and controls the camera to capture an image of the first mark, and controls the first moving mechanism and the second moving mechanism to adjust the relative position between the die adsorbed by the first suction head and the second suction head based on the image of the first mark captured.

7. The bonding apparatus according to claim 1, wherein the first light is visible light and the second light is infrared light.

8. A bonding method for bonding the die to the substrate using a bonding apparatus according to any one of claims 1 to 7.

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