Method for bonding chips and system for performing the method

Abstract

To provide a method and a system for collectively boding a plurality of chips.SOLUTION: A method for bonding chips includes the steps of: initially positioning a first bonding head holding a first chip at a first predetermined position relative to an initial position of a substrate chuck supporting a bonding surface; initially positioning a second bonding head holding a second chip at a second predetermined position relative to the initial position of the substrate chuck; alternating between receiving updated position information of the substrate chuck and repositioning the first bonding head based on the received updated position information until the first chip contacts the bonding surface; alternating between receiving updated position information of the substrate chuck and repositioning the second bonding head based on the received updated position information until the second chip contacts the bonding surface; and bonding the first chip and the second chip to the bonding surface.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a method of bonding chips, including bonding a plurality of chips together at once.

Background Art

[0002] Advanced packaging techniques require precise and accurate control and placement of chips. To increase productivity / throughput, it is desirable in the art to use multiple bonding heads simultaneously to bond multiple source chips to a bonding surface. However, even when multiple bonding heads are operated simultaneously as much as possible, one chip on one bonding head will always contact the bonding surface before the chips on the other bonding heads. This initial contact by one chip on one bonding head causes the carriage supporting the bonding surface to tilt around the center of rotation, thereby tilting the substrate chuck and the substrate. Tilting around the center of rotation of the carriage induces an increase in the alignment amount and unstable alignment for the remaining chips on the bonding head. Furthermore, due to factors outside the operator's control, it is common for the position of the substrate to be disturbed in all dimensions (X, Y, Z, tilt, tip, rotation) throughout the bonding process. These disturbances may cause misalignment.

[0003] FIG. 23 shows a schematic side view of the joint portion 1 of a joint system in which tilting occurs around the rotation center of the carriage. The joint portion 1 includes a plurality of joint heads 2 coupled to the bridge 3. Below the plurality of joint heads 2, there is a carriage 4 that holds a substrate chuck 5 that chucks a substrate 6. The carriage 4 rides on a base 8 via a bearing 7. FIG. 23 shows the moment when the plurality of joint heads 2 attempt to join two chips 9 to the joint surface 10 on the substrate 6. However, as described above, even if two chips 9 are to be joined to the joint surface 10 simultaneously, one chip will necessarily come into contact with the joint surface 10 first. As shown in FIG. 23, when this occurs, the carriage 4 rotates in the direction of 11 around the rotation center CR, including all the structures carried by the carriage. This rotation causes an offset angle 12 that adversely affects the alignment of the second chip that contacts the joint surface 10 after the first chip contacts the joint surface 10. This rotation causes an alignment error in the joining of the next chip. Since the tilt amount varies according to the joining position, it is difficult to compensate for such additional errors. In the system of FIG. 23, tilting of the carriage 4 greater than 0.2 μradian caused by the joining process results in an alignment error on the order of greater than 10 nm, for example. The relationship between the alignment error and the tilt can be a function of the distance between the rotation centers CR of the carriage 4 in the joining direction (Z-axis). Although not shown in FIG. 23, as described above, other unavoidable disturbances may occur at any moment of the joint surface, and as a result, the substrate can move from its initial position in all its dimensions (X, Y, Z, tilt, tip, rotation).

[0004] Therefore, there is a need in the art for a method and system for eliminating or minimizing alignment errors caused by tilting and / or other disturbances around the rotation center of the carriage when joining a plurality of source chips to a joint surface. SUMMARY OF THE INVENTION

[0005] A method for bonding chips includes alternately performing, until the first chip contacts the bonding surface, the steps of initially positioning a first bonding head that holds a first chip at a first predetermined position with respect to an initial position of a substrate chuck that supports a bonding surface, initially positioning a second bonding head that holds a second chip at a second predetermined position with respect to the initial position of the substrate chuck, receiving updated position information of the substrate chuck, and repositioning the first bonding head based on the received updated position information; alternately performing, until the second chip contacts the bonding surface, the steps of receiving updated position information of the substrate chuck and repositioning the second bonding head based on the received updated position information; and bonding the first chip and the second chip to the bonding surface.

[0006] A system for bonding chips includes a first bonding head that holds a first chip, a second bonding head that holds a second chip, a substrate chuck that supports a bonding surface, one or more processors, and one or more memories that store instructions, which, when executed by the one or more processors, cause the system to perform the steps of initially positioning the first bonding head at a first predetermined position with respect to an initial position of the substrate chuck, initially positioning the second bonding head at a second predetermined position with respect to the initial position of the substrate chuck, alternately performing, until the first chip contacts the bonding surface, the steps of receiving updated position information of the substrate chuck and repositioning the first bonding head based on the received updated position information, alternately performing, until the second chip contacts the bonding surface, the steps of receiving updated position information of the substrate chuck and repositioning the second bonding head based on the received updated position information, and bonding the first chip and the second chip to the bonding surface.

[0007] A method for manufacturing a plurality of articles includes the steps of initially positioning a first bonding head holding a first chip at a first predetermined position with respect to an initial position of a substrate chuck supporting a bonding surface, initially positioning a second bonding head holding a second chip at a second predetermined position with respect to the initial position of the substrate chuck, receiving updated position information of the substrate chuck, and repositioning the first bonding head based on the received updated position information, alternately performing these steps until the first chip contacts the bonding surface, receiving updated position information of the substrate chuck, and repositioning the second bonding head based on the received updated position information, alternately performing these steps until the second chip contacts the bonding surface, bonding the first chip and the second chip to the bonding surface, and singulating the substrate to manufacture the plurality of articles.

Brief Description of the Drawings

[0008] The embodiments are merely illustrative and are not limited to the accompanying drawings.

[0009]

Figure 1

[0010]

Figure 2

[0011]

Figure 3

[0012]

Figure 4

[0013]

Figure 5

[0014] Figure 5(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t1 in FIG. 5(a).

[0015] Figure 5(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that in FIG. 5(b).

[0016] Figure 5(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t1.

[0017] Figure 5(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that in FIG. 5(d).

[0018]

Figure 6

[0019] Figure 6(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t2.

[0020] Figure 6(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that in FIG. 6(b).

[0021] Figure 6(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t2.

[0022] Figure 6(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that in FIG. 6(d).

[0023]

Figure 7

[0024] Figure 7(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t3.

[0025] Figure 7(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that in FIG. 7(b).

[0026] Figure 7(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t3.

[0027] Figure 7(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that of Figure 7(d).

[0028]

Figure 8

[0029] Figure 8(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t4.

[0030] Figure 8(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that of Figure 8(b).

[0031] Figure 8(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t4.

[0032] Figure 8(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that of Figure 8(d).

[0033]

Figure 9

[0034] Figure 9(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t5.

[0035] Figure 9(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that of Figure 9(b).

[0036] Figure 9(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t5.

[0037] FIG. 9(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that in FIG. 9(d).

[0038]

Figure 10

[0039] FIG. 10(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t6.

[0040] FIG. 10(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that in FIG. 10(b).

[0041] FIG. 10(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t6.

[0042] FIG. 10(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that in FIG. 10(d).

[0043]

Figure 11

[0044] FIG. 11(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t6.

[0045] FIG. 11(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that in FIG. 11(b).

[0046] FIG. 11(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t7.

[0047] FIG. 11(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that in FIG. 11(d).

[0048]

Figure 12

[0049] Fig. 12(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t8.

[0050] Fig. 12(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to Fig. 12(b).

[0051] Fig. 12(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t8.

[0052] Fig. 12(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to Fig. 12(d).

[0053]

Figure 13

[0054] Fig. 13(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t9.

[0055] Fig. 13(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to Fig. 13(b).

[0056] Fig. 13(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t9.

[0057] Fig. 13(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to Fig. 13(d).

[0058]

Figure 14

[0059] Fig. 14(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t10.

[0060] Figure 14(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that of Figure 14(b).

[0061] Figure 14(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t10.

[0062] Figure 14(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that of Figure 14(d).

[0063]

Figure 15

[0064] Figure 15(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t11.

[0065] Figure 15(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that of Figure 15(b).

[0066] Figure 15(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t11.

[0067] Figure 15(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that of Figure 15(d).

[0068]

Figure 16

[0069] Figure 16(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t12.

[0070] Figure 16(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that of Figure 16(b).

[0071] FIG. 16(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t12.

[0072] FIG. 16(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the opposite side of FIG. 16(d).

[0073]

Figure 17

[0074] FIG. 17(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t13.

[0075] FIG. 17(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the opposite side of FIG. 17(b).

[0076] FIG. 17(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t13.

[0077] FIG. 17(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the opposite side of FIG. 14(d).

[0078]

Figure 18

[0079] FIG. 18's 9(g) is a schematic side view on the opposite side of FIG. 18's 9(f) showing the tilting of the product substrate in the embodiment.

[0080] FIG. 18's 10(f) is a schematic side view of the bonding head and the substrate in the XZ plane showing the product substrate still tilted in the first direction at time t6 in the embodiment.

[0081] FIG. 18's 10(g) is a schematic side view on the opposite side of FIG. 18's 10(f) showing tilting of the chip chuck in the embodiment.

[0082] 11(f) and 11(g) of FIG. 18 are schematic side views of the XZ plane of the bonding head and the substrate, showing that the product substrate tilted (θY) in the first direction while the bonding head was in contact with the product substrate at time t7.

[0083]

Figure 19

[0084] 13(f) and 13(g) of FIG. 19 are schematic side views of the XZ plane of the bonding head and the substrate, showing that the product substrate tilted (θY) in the second direction at time t9 in the embodiment.

[0085] 14(f) and 14(g) of FIG. 19 are schematic side views of the XZ plane of the bonding head and the substrate, showing that the product substrate tilted (θY) in the second direction at time t10 according to the embodiment.

[0086]

Figure 20

[0087] 16(f) and 16(g) of FIG. 20 are schematic side views of the XZ plane of the bonding head and the substrate, showing that the product substrate tilted (θY) in the first direction at time t12 according to the embodiment, and the bonding head stage of the bonding head moved the chip chuck so as to match the tilt of the product substrate.

[0088] 17(f) and 17(g) of FIG. 20 are schematic side views of the YZ plane of the bonding head and the substrate, showing that the product substrate tilted (θY) in the first direction at time t13 in the embodiment, and the chip contacted the product substrate.

[0089]

Figure 21

[0090] Figure 21(b) is a timing chart of the Z-direction positions of the four bonding heads and the substrate in the embodiment,

[0091] Figure 21(c) is a timing chart of the total Z-direction force applied by the four bonding heads in the embodiment,

[0092] Figure 21(d) is a timing chart of the residual force of the four bonding heads in the embodiment,

[0093] Figure 22(e) is the same timing chart as Figure 4 shown together with Figures 22(a) to (d).

[0094]

Figure 22

[0095]

Figure 23

[0096] It will be understood by those skilled in the art that the elements in the figures are shown in a simplified and clarified manner and are not necessarily drawn to scale. For example, some dimensions of the elements in the figures may be exaggerated compared to other elements to assist in understanding the implementation of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0097] The following description, in combination with the drawings, is provided to assist in understanding the teachings disclosed herein. The following discussion focuses on specific implementations of the teachings. This focus is provided to aid in explaining the teachings and should not be construed as a limitation on the scope or applicability of the teachings.

[0098] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. Many details regarding specific materials and processing operations are conventional and can be found in textbooks and other sources of information in the relevant technical field, unless otherwise described herein.

[0099] Figure 1 is a schematic side view of a bonding system 100 in an embodiment. As shown in Figure 1, the bonding system 100 includes a chip source section 102, a chip transfer / activation section 104, and a chip bonding section 106. The chip source section 102 is the part of the entire bonding system 100 that includes the source chips used in the bonding process. The chip transfer / activation section 104 is the part of the entire bonding system 100 that transfers chips from the chip source section 102 to the chip bonding section 106. In another configuration, the chip source section could be a separate device. Similarly, the chip activation section could be a separate device. The chip transfer / activation section 104 activates the source chips to make them bondable. In an alternative embodiment, the chip transfer / activation section 104 activates a plurality of chips 124 before the chips are placed in the chip source section 102. The chip bonding section 106 receives the activated chips and performs the bonding.

[0100] The chip source section 102 includes one or more sources for the chip. For example, as shown in FIG. 1, the chip source section can include a substrate 114 held by a source chuck 110 having a chip 124 thereon, and / or can include a front opening unified / universal pod 112 (known in the art as a "FOUP"). The FOUP can accommodate a plurality of substrates 114 and chips 124. Other chip sources known in the art, such as trays, adhesive tapes within frames, adhesive layers on rigid substrates, etc., can be used for the chip source section 102. As used herein, a chip refers to an integrated circuit, also referred to as a microchip, computer chip, etc. A chip can be defined as a small block of semiconductor material on which a given functional circuit is fabricated. In the context of a wafer / substrate divided into individual chips, a chip is known as a die. A chip typically carries a set of integrated electronic components and circuits formed thereon by patterning, coating, etching, doping, plating, singulation, etc. A chip typically has electrical functions such as memory, logic, field programmable gate array (FPGA), accelerator circuits, application specific integrated circuit (ASIC), security coprocessor, graphics processing unit (GPU), machine learning circuits, dedicated processors, controllers, devices, electrical circuits, arrays of passive components, etc. A chip can also be a microelectromechanical systems (MEMS) device, an optical device, an electro-optical device, etc.

[0101] The chip transfer and activation section includes a transfer robot 126 that can lift and carry the substrate 114 to the second substrate chuck 130 in the chip bonding section 106. As understood in the art, the transfer robot 126 generally provides operations for lifting, carrying, and placing substrates from one location to another, such as from one substrate chuck to another or from a substrate storage location to a substrate chuck, and includes a hand and a robotic arm. The transfer robot 126 can be any suitable device known in the art, such as a robot like the wafer handling robot RR756L15 provided by Rotze Co., Ltd. in Fukuyama City, Hiroshima Prefecture, Japan. The chip transfer and activation section 104 further includes an activation device 128. The activation device 128 is a device that prepares the chips to be transported for hybrid bonding. Hybrid bonding is a chip bonding technique that brings into contact the surfaces of electrically insulating (silicon dioxide) chips having embedded metal (e.g., copper) pads. The metal pads are aligned with each other, while the electrically insulating surfaces are joined to each other through direct contact. Then, heat is applied to the bonding structure, causing the metal pads to expand more relative to the electrically insulating material and come into contact with each other, thereby forming an electrical connection between the chips. In an exemplary embodiment, the activation device 128 can include a fluid source that applies, for example, deionized water, and a plasma source that activates the surface of the chips before they are carried by the transfer robot 126. Due to the material of the chips (i.e., dielectric), when the activated chips come into contact with another chip, a fusion bond occurs between the dielectric surfaces of the two chips.

[0102] The chip bonding section 106 includes a second substrate chuck 130 for receiving the substrate 114 having the chips carried by the transfer robot 126 and activated by the activation device 128. In this specification, the second substrate chuck 130 is also referred to as the intermediate substrate chuck. The chip bonding section 106 can include a bridge 132 to which the intermediate substrate chuck 130 is attached. The chip bonding section 106 also includes a plurality of bonding heads 134 attached to the bridge 132.

[0103] Figure 2 shows a schematic enlarged view of portion 160 of chip bonding section 106. As shown in FIG. 2, bonding head 134 may include a bonding head base 116, a bonding head stage 120, a bonding head sensor (not shown), and a chip chuck 122. The bonding head sensor may include interference, spectral interference, linear encoders, rotary encoders, capacitive sensors, potentiometric sensors, inductive sensors, etc. that are used to provide information on the relative position of the chip chuck. The processor can use the information from the bonding head sensor to control the position of the chip chuck attached to the bonding head stage. The chip chuck holds the back surface of chip 124 along the outer periphery of the chip. In the embodiment shown in FIG. 2, first bonding head BH1 holds first chip 124a, and second bonding head BH2 holds second chip 124b (similarly, third bonding head BH3 that holds third chip 124c and fourth bonding head BH4 that holds fourth chip 124d shown in subsequent figures). As described below, additional bonding heads and additional chips may be present. Bonding head stage 120 can include bonding head base 116 and may include one or more actuators that move the chip chuck at least in the Z direction toward product substrate chuck 136 with respect to bonding head base 116. Bonding head stage 120 may include one or more actuators that move chip chuck 122 in six axes (X direction, Y direction, Z direction, tip (θX, rotation about the X axis), tilt (θY, rotation about the Y axis), θZ (rotation about the Z axis)). The bonding stage is a mechanical motion system that can manipulate the chip in the desired direction of motion. It can include the bearing mechanisms and actuators necessary to facilitate motion in the desired direction. Bonding head stage 120 may be a series of stacked stages that move chip chuck 122. Alternative designs of the system use a single stage with parallel kinematics to enable multi-DoF (degrees of freedom) motion. Each stage can move the chip chuck along one of the six axes. One or more of the stages can move the chip along two or more of the six axes.The bonding stage 120 may be a multi-axis positioner having a plurality of actuators and parallel kinematics for moving the chip chuck 122 along up to six axes. An example of a multi-axis positioner is a hexapod stage that includes a plurality of actuators attached to two swivel joints. Thus, overall, the chip can move in six dimensions: X, Y, Z, tilt, tip, and rotation. The actuators may be voice coil motors, piezoelectric motors, linear motors, nut and screw motors, piezo-actuated stages, brushless DC motor stages, DC motor stage stepping motors, which are configured to move the chip chuck 122 between the product substrate chuck 136 and apply a controlled force to the chip 124 when the chip contacts the bonding surface 140. The chip chuck 122 can hold the chip 124 on the chuck surface using vacuum, electrostatic force, electromagnetic force, mechanical gripping force, or any other method of releasably holding the chip to the chuck surface of the bonding head 134. The chip bonding section 106 further includes a product substrate chuck 136 that holds the product substrate 138. The product substrate 138 has a bonding surface 140. The bonding surface 140 in the illustrated embodiment is the upper surface of the product substrate 138. In another exemplary embodiment, the bonding surface may be the surface of a chip already on the product substrate 138. That is, the bonding described herein may be used to bond a source chip onto the surface of a product substrate and / or to bond a source chip to the surface of a product chip on a product substrate.

[0104] The bonding system 100 may further include sensors for identifying the position of the product substrate 138. More specifically, the sensors detect the X-direction position, Y-direction position, tip position, tilt position, and rotation position of the product substrate chuck 136 relative to the starting / initial position of the product substrate chuck 136. FIG. 2 shows a first sensor for measuring the X-direction position, a second sensor (not shown) for measuring the Y-direction position, and a third sensor (not shown) for measuring the Z-direction position, and may include additional sensors. The bonding system 100 includes a plurality of sensors arranged around the substrate chuck 136 to obtain the position, orientation, or both of the substrate. These sensors measure one or more of the X-direction position, Y-direction position, tip position, tilt position, and rotation position. These sensors can be any of an optical-interference sensor, a spectral-interference sensor, a linear encoder, a rotary encoder, a capacitance sensor, a potentiometer sensor, an inductive sensor, etc. One or more positions can be calculated based on the measurement values by a plurality of sensors. Since the product substrate chuck 136 holds the substrate, the position information of the substrate chuck also indicates the relative position of the substrate 138. Therefore, in this specification, the position of the substrate chuck and the position of the substrate are used interchangeably. The starting / initial position of the substrate chuck 136 and the substrate 138 is the position shown in FIG. 2 before performing the bonding method described below.

[0105] As shown in FIGS. 1 and 2, the bonding system 100 further includes a carriage 142 that supports the substrate chucks 136 and one or more transfer heads 148, and one or more alignment devices (not shown). The carriage 142 may be placed on the bearing 118 and may be part of a substrate chuck positioning system. The substrate chuck positioning system may include one or more motion stages for providing up to six degrees of freedom of motion of the substrate chuck relative to a set of parallel bonding heads.

[0106] As described above, the chip bonding section 106 can further include a plurality of alignment devices 146 and a plurality of transfer heads 148, all of which are carried by the carriage 142. As shown in FIG. 1, the bearings 118 of the carriage 142 can support the alignment devices 146 and the transfer heads 148. Each of the plurality of transfer heads 148 can include any one of various methods of holding the chip, including, but not limited to, a Bernoulli chuck, a suction nozzle, an electrostatic chuck, an edge gripping chuck, a latch mechanism, or any method that releasably holds the chip. Each of the plurality of transfer heads 148 can include an actuator for moving at least in the Z direction toward and away from the bridge 132. The plurality of alignment devices 146 are used to inspect the alignment of the chips on the plurality of bonding heads 134 after transferring the chips to the plurality of bonding heads 134. Each alignment device can be a microscope, a camera, an interferometer, or any type of measuring device capable of measuring the position of each chip on the sub-mm, micron, or nanometer scale. The information provided by the plurality of alignment devices 146 enables the operator to know whether each chip is at the target position within an acceptable error amount. The plurality of alignment devices 146 can be any suitable device known in the art, for example, a 20x microscope with a 5 megapixel camera such as the CI-5MGMCL of Canon Inc. in Tokyo, Japan. The plurality of transfer heads 148 are used to transfer the chips from the substrate 114 held by the intermediate substrate chuck 130 to the plurality of bonding heads 134.

[0107] The number of bonding heads included in the plurality of bonding heads is at least two, but may be 300. The number of bonding heads can be, for example, 2 to 300, 5 to 100, or 8 to 16. The arrangement of the plurality of bonding heads may be in the formation of columns and rows such as 1×2, 2×1, 2×2, 1×3, 3×1, 2×3, 2×3, 3×2, 3×3, 4×1, 1×4, 4×2, 2×4, 3×4, 4×3, 4×4. In the illustrated exemplary embodiment, the plurality of bonding heads are a total of four bonding heads of 2×2. The number and arrangement of the plurality of transfer heads can be the same as the number and arrangement of the plurality of bonding heads. Alternatively, the number and arrangement of the plurality of transfer heads may be more than the number and arrangement of the plurality of bonding heads.

[0108] The chip bonding section 106 may further include a microscope (not shown) on the carriage 142 and a microscope (not shown) on the bridge 132. The microscope on the carriage 142 is movable together with the plurality of transfer heads 148, the product substrate chuck 136, and the plurality of alignment devices 146. The microscope on the carriage is directed upward in the direction toward the intermediate substrate chuck 130. The microscope on the carriage functions to measure the positions of the plurality of chips on the substrate 114. The microscope on the bridge is directed downward in the direction toward the product substrate chuck 136. The microscope on the bridge functions to measure the positions of the chips on the product substrate 138. Each microscope may be a 20x microscope equipped with a suitable device known in the art, for example, a 5 megapixel camera such as CI-5MGMCL of Canon Kabushiki Kaisha in Tokyo, Japan.

[0109] The bonding system 100 can be adjusted and controlled by one or more processors 154 (controllers) that communicate with one or more components and / or subsystems, such as a chip source section 102, a chip transfer / activation section 104, a chip bonding section 106, a source chuck 110, a FOUP 112, a transfer robot 126, an activation device 128, an intermediate substrate chuck 130, a plurality of bonding heads 134, a sensor 162, a product substrate chuck 136, or a product substrate positioning system including a carriage 142, a plurality of alignment devices 146, a plurality of transfer heads 148, and an optional microscope. The processor 154 can operate based on instructions in a computer-readable program stored in a non-transitory computer memory 156. The processor 154 can be one or more of, or include, a CPU, an MPU, a GPU, an ASIC, an FPGA, a DSP, and a general-purpose computer. The processor 154 can be a dedicated controller or a general-purpose computing device adapted to be a controller. Examples of non-transitory computer-readable memories include, but are not limited to, RAM, ROM, CD, DVD, Blu-Ray (registered trademark), hard drive, network-connected storage (NAS), intranet-connected non-transitory computer-readable storage devices, and internet-connected non-transitory computer-readable storage devices. All of the steps described herein can be executed by the processor 154.

[0110] FIG. 3 is a flowchart of a method for bonding chip 300 using bonding system 100. The method for bonding chip 300 begins at step S302, where a first bonding head (e.g., first bonding head BH1) is initially positioned at a first predetermined position relative to an initial position of a substrate chuck (e.g., product substrate chuck 136). Here, the first bonding head holds a first chip (e.g., first chip 124a), and the substrate chuck supports a bonding surface (e.g., bonding surface 140). However, some steps that may be part of the bonding method may be performed before the first step shown in FIG. 3. For example, the following additional steps may be performed before step S302. First, desired chip information can be received, including what quality of chip is required and where the chip should be placed on the bonding surface. The quality of the chip can be defined as other characteristics affecting the performance of the chip, which can vary depending on the maximum clock rate, the percentage of transistors that function at one or more specified clock rates, the local cache size, the thermal conductivity, and the manufacturing performance of the chip. After receiving the chip information, if the transfer robot 126 is not yet activated, it transports the source substrate 114 through the activation device 128, activates the chip in the manner described above, and then the source substrate 114 is received in the chip bonding section 106. After passing through the activation device 128 with the chip in an activated state, the transfer robot 126 transports the source substrate 114 to the second substrate chuck 130 in the chip bonding section 106. In an alternative embodiment, the chips on the source substrate 114 are already activated and are transferred directly from the chip source section 102 to the chip bonding section 106.

[0111] The source substrate 114 having the activated chips 124 can then be chucked by the second substrate chuck 130. Next, when the source substrate 114 having the activated chips 124 is attached to the second substrate chuck 130, the positions of the plurality of chips 124 can be measured using a microscope. This step can be performed by moving the carriage 142 until the microscope comes under the plurality of chips 124. If the feedback from the first microscope indicates that a particular one of the plurality of chips 124 is beyond an acceptable error, a replacement substrate 114 needs to be prepared. If the feedback from the microscope indicates that the plurality of chips 124 are positioned at appropriate positions within an acceptable error, the method can proceed.

[0112] Next, a first set of chips from the source substrate 114 can be transferred to the plurality of bonding heads 134. This step can be performed by first moving the carriage 142 until the plurality of transfer heads 148 are positioned under the plurality of chips 124. The plurality of transfer heads 148 can include the same number of heads having the same pitch as the plurality of bonding heads 134. The plurality of transfer heads 148 are configured to mirror the plurality of bonding heads 134, and the plurality of transfer heads 148 can transfer the same number of chips that the plurality of bonding heads can bond in a single bonding process. The plurality of transfer heads 148 can pick up the first set of chips from the source substrate 114, for example, by activating a vacuum force. The plurality of transfer heads 148 can maintain the vacuum force while the plurality of transfer heads 148 carrying the first set of chips are moved via the carriage 142 to a position under the plurality of bonding heads 134. Either the plurality of transfer heads 148 or the plurality of bonding heads 134 move (or both move simultaneously) toward each other until the first chip set reaches the position where it is to be transferred to the plurality of bonding heads 134. Once sufficiently close, the vacuum force on the plurality of transfer heads 148 is terminated and the vacuum force of the plurality of bonding heads 134 is activated, thereby enabling the first set of chips to be transferred to the plurality of bonding heads 134. After the chips 124 (the first set of chips) are transferred to the bonding heads, the carriage 142 is moved to position the product substrate 138 such that the bonding surface 140 reaches a predetermined position relative to the bonding heads 134 holding the first set of chips. That is, the processor 154 can receive / process information regarding the location where the chips 124 (the first set of chips) of the current bonding procedure are to be placed on the bonding surface 140, and based on this information, the processor moves the carriage 142 so that the chips 124 held by the bonding heads 134 are properly positioned in the X / Y directions. The moment when all these steps are executed immediately before step S302 is the moment shown in FIG. 2. That is, at the moment shown in FIG. 2, each bonding head 134 holds a chip 124 positioned above the bonding surface 140, and the system is ready to proceed with the bonding method.

[0113] Once the above initial step is completed, the bonding method 300 is ready to start the above step S302 of initially positioning the first bonding head at the first predetermined position (the first target chip position 105a) with respect to the initial position of the substrate chuck for the product chip site. The method 300 also includes performing step S304 of initially positioning a second bonding head (e.g., the second bonding head BH2) that holds a second chip (e.g., chip 124b) at a second predetermined position of a second product chip site (the second target chip position 105b) that is at the initial position of the substrate chuck (e.g., the product substrate chuck 136). FIG. 4 shows a control state timing chart showing the change in the state of the four bonding heads during the bonding process according to an exemplary embodiment. The control state timing chart represents different control states of each bonding head having different patterns (402, 404, 406, 408, and 410). In FIG. 4, the X-axis is Time, the bonding process starts at time t0, and ends at time tf. As shown in FIG. 4, the steps of S302 and S304 can occur during an overlapping period of the bonding process. That is, the first bonding head BH1 and the second bonding head BH2 can be moved to their respective initial predetermined positions based on the initial position of the substrate chuck during the overlapping period such that at least a part of step S302 is executed simultaneously with step S304. In another embodiment, the period during which the first bonding head is positioned may occur exactly during the same period as the second bonding head is positioned, or may occur after or before the second bonding head is positioned. This same principle can also be applied to the remaining bonding heads, e.g., the third bonding head BH3 and the fourth bonding head BH4 shown in the exemplary embodiment. In the timing chart of FIG. 4, the time when the bonding head reaches the initial predetermined position is represented by the first pattern 402. Each control state of the bonding head stage 120 while in the state represented by the first pattern 402 is a state where each of the bonding head stages is under operation control without considering the disturbance to the position of the product substrate on the product substrate chuck. In the exemplary embodiment of FIG. 4, the initial positioning time is different for each bonding head.That is, for all the bonding heads, the same steps corresponding to step S302 and step S304 can be executed. As shown in the key of FIG. 4 corresponding to the first pattern 402, during this period of initially positioning the bonding head, while the bonding head is moved to a predetermined position in consideration of the initial position of the substrate, the bonding head is moved without considering the updated position information of the substrate (the updated position of the substrate is identified from a sensor that detects the change in the position of the substrate). Generally, during this period of initial positioning, each bonding head is first moved to the desired X / Y coordinate position and the desired θZ direction where the chip is to be bonded, and then the bonding head moves downward in the Z direction. That is, during most of the initial positioning period, the bonding head brings the chip closer to the bonding surface in the Z direction without changing the position of the chip in the X or Y direction. The predetermined position of each bonding head is predicted in advance based on the desired bonding position, the measured position of the chip on the chip chuck, the desired positioning trajectory, and the measured position of the chip chuck.

[0114] FIGS. 5(a) to (e) show different schematic views of the bonding head and the substrate positions at time t1 that occur during the period when step S302 and step S304 are being executed. The timing chart of FIG. 4 shows the moment of the bonding process at which time t1 occurs. FIG. 5(a) is a schematic top view of an exemplary embodiment in which four bonding heads are arranged with respect to the surface of the substrate at time t1 of FIG. 4. FIG. 5(b) is a schematic side view of the YZ plane of the bonding head and the substrate at time t1. FIG. 5(c) is a schematic side view of the YZ plane of the bonding head and the substrate on the opposite side to FIG. 5(b). FIG. 5(d) is a schematic side view of the XZ plane of the bonding head and the substrate at time t1. FIG. 5(e) is a schematic side view of the XZ plane of the bonding head and the substrate on the opposite side to FIG. 5(d). From all these figures, all the positions of the four exemplary embodiments of the bonding heads (e.g., bonding heads BH1, BH2, BH3, and BH4) at time t1 can be seen.

[0115] As shown in FIGS. 5(a) to 5(e), at time t1, the bonding heads BH1, BH2, BH3, and BH4 are located at positions above the bonding surface 140 at specific X, Y, and Z direction positions. That is, during the process of initially positioning the bonding heads based on the initial position of the substrate chuck 138, the carriage 142 has already been moved so that the chip 124 is located at a predetermined X / Y coordinate position above the bonding surface 140 and in the θZ direction, and is in the process of moving downward toward the bonding surface in the Z dimension. Thus, as shown in FIG. 5(a), when steps S302 and S304 are executed, the bonding heads BH1, BH2, BH3, and BH4 hold any one of the chips 124a, 124b, 124c, and 124d, and the bonding heads BH1, BH2, BH3, and BH4 are located above the bonding surface 140. This predetermined X and Y direction positions and θz direction correspond to the target X and Y direction positions and θz direction on the substrate where the chip is desired to be placed. As shown in FIGS. 5(a) to 5(e), in the present embodiment, there are a first target chip position 150a corresponding to the first bonding head BH1, a second target chip position 150b corresponding to the second bonding head BH2, a third target chip position 150c corresponding to the third bonding head BH3, and a fourth target chip position 150d corresponding to the fourth bonding head BH4. FIGS. 5(a) to 5(e) (and subsequent figures) also include the already bonded chip 152, which would have been bonded in a previous bonding process following the same bonding method 300 described herein.

[0116] In the illustrated embodiment, all the bonding heads face the substrate, but in some examples, not all the bonding heads face the bonding surface. The advantages of the bonding method 300 are mainly achieved when at least two bonding heads are actively used, but the bonding method 300 can still be executed as long as at least one of the bonding heads is used. If any of the available bonding heads does not face the bonding surface, the one that does not face the bonding surface is not activated, and at least one (preferably two or more) of the bonding heads facing the bonding surface is activated.

[0117] As the step of initially positioning the bonding head progresses, the bonding head 134 is actuated such that the chips 124a, 124b, 124c, 124d move in the Z direction toward the bonding surface 140. Further, the bonding head can lower the chips at a predetermined tip and tilt so that the chips conform to the substrate. This tip and tilt of each chip can be determined by one or both of the chip-tilt rotation of the substrate and the chip-tilt rotation of each chip at each target position when held by a chip chuck on the bonding head. When the bonding head reaches within a predetermined Z position or an estimated predetermined gap from the chip held by the chip chuck and an estimated value of the substrate plane is obtained, the step of initially positioning the bonding head at a predetermined X / Y position, i.e., steps S302 and S304, are completed based on the initial position of the substrate chuck. The same applies to all other bonding heads that exist, i.e., the corresponding positioning steps for any other bonding head are completed. In the exemplary embodiment shown in FIG. 4, the four bonding heads BH1, BH2, BH3, BH4 reach their respective predetermined X, Y, and Z positions at different times. That is, when a particular bonding head reaches its predetermined position, a part of the bonding process in which the bonding head is positioned based on the initial position of the substrate chuck is completed without considering the updated position information of the substrate chuck (or the substrate). The Z-direction position when the initial positioning period is completed is determined by a predetermined gap from the substrate surface. Some examples of these gaps can be 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, 100 μm, etc.

[0118] After the bonding heads BH1, BH2, BH3, and BH4 reach their predetermined X, Y, and Z positions (i.e., after steps S302 / S304 are completed), the method proceeds to steps S306 and S308. This transition is represented in FIG. 4 by the end of the first pattern 402 and the start of the second pattern 404. In step S306, the updated position information of the substrate chuck (or substrate) is continuously monitored and received, and based on the received updated position information, the first bonding head (e.g., bonding head BH1) is repositioned. In step S306, this continuous monitoring can be implemented by alternately performing the reception of the updated position information of the substrate chuck (or substrate) and the repositioning of the first bonding head (e.g., bonding head BH1) based on the received updated position information. This alternating operation of reception and repositioning is performed until the first chip contacts the bonding surface. That is, step S306 starts after the first bonding head (e.g., bonding head BH1) reaches the predetermined Z position and continues until the first chip (e.g., chip 124a) contacts the bonding surface (e.g., bonding surface 140). When contact occurs, step S306 ends. This period is represented by the second pattern 404 in FIG. 4. As described in the key to FIG. 4, during the period represented by the second pattern 404, the bonding head is moved while considering changes in the position of the substrate (estimated through the sensed change in the position of the substrate chuck). Each control state of the bonding head stage 120 while in the state represented by the second pattern 404 is a state in which each of the bonding head stages is under operation control considering the disturbance in the position of the product substrate 138 on the product substrate chuck 136.

[0119] Similarly, in step S308, the method alternately performs receiving updated position information of the substrate chuck (or substrate) and repositioning the second bonding head (e.g., bonding head BH2) based on the received updated position information. Receiving the updated position information of the substrate chuck can be performed using one or more sensors that measure the position of the substrate chuck at a measurement rate. The processor can perform signal conditioning using analog techniques or digital techniques, or both. Signal conditioning can include averaging, time filtering, spatial transformation, etc. The position of each bonding head is controlled by a bonding head position control subsystem. The processor can supply the substrate position to the bonding head position control subsystem at a rate lower than the measurement rate. Each bonding head position control subsystem supplies a repositioning command to each bonding head stage. This alternating operation of receiving and repositioning is performed until the second chip (e.g., chip 124b) contacts the bonding surface (e.g., bonding surface 140). That is, step S308 is started after the second bonding head reaches a predetermined Z position and continues until the second chip contacts the bonding surface. When contact occurs between the chip and the bonding surface, step S308 ends. As shown in FIG. 4, the timing of the movement of the bonding head can be such that steps S306 and S308 start and end at different times with some overlap. When there are more bonding heads (such as four in the illustrated exemplary embodiment), corresponding steps of alternately receiving the updated position information of the substrate chuck and repositioning the bonding head based on the received updated position information can be implemented for each additional bonding head. Also, as shown in FIG. 4, the durations of steps S306 and S308 may be different. That is, as described above, the steps of alternately receiving and repositioning continue until the chip contacts the bonding surface. The time required for a particular chip to reach the bonding surface varies. Therefore, as shown in the exemplary embodiment of FIG. 4, the first chip 124a held by the first bonding head BH1 reaches the bonding surface (time t4) before the second chip 124b held by the second bonding head BH2 reaches the bonding surface (time t7).In this exemplary embodiment, the period of step S308 is longer than the period of step S306.

[0120] Figures 6(a) to 6(e) are schematic diagrams showing different positions of the bonding head and the substrate at time t2 that occur during the execution of steps S306 and S308. As shown in FIG. 4, t2 occurs when all four exemplary bonding heads are in the state represented by pattern 404. FIG. 6(a) is a schematic top view of the bonding head and the substrate corresponding to time t2 in FIG. 4. FIG. 6(b) is a schematic side view of the YZ plane of the bonding head and the substrate at time t2. FIG. 6(c) is a schematic side view of the YZ plane of the bonding head and the substrate on the side opposite to FIG. 6(b). FIG. 6(d) is a schematic side view of the XZ plane of the bonding head and the substrate at time t2. FIG. 6(e) is a schematic side view of the XZ plane of the bonding head and the substrate on the side opposite to FIG. 6(d). From all these figures, all the positions of the four exemplary bonding heads (e.g., bonding heads BH1, BH2, BH3, and BH4) at time t2 can be seen.

[0121] Figures 7(a) to 7(e) are schematic diagrams showing different positions of the bonding head and the substrate at time t3 that occur immediately after time t2 during the period when steps S306 and S308 are executed. As shown in FIG. 4, t3 occurs when all four bonding heads are in the state represented by pattern 404 immediately after time t2. The period between t2 and t3 depends on the responsiveness of the bonding head movement control system and can be, for example, 2 to 10 times the sample rate of the substrate position measurement system, which can be 5 ms. FIG. 7(a) is a schematic top view of the bonding head and the substrate corresponding to time t3 in FIG. 4. FIG. 7(b) is a schematic side view of the YZ plane of the bonding head and the substrate at time t3. FIG. 7(c) is a schematic side view of the YZ plane of the bonding head and the substrate on the side opposite to FIG. 7(b). FIG. 7(d) is a schematic side view of the XZ plane of the bonding head and the substrate at time t3. FIG. 7(e) is a schematic side view of the XZ plane of the bonding head and the substrate on the side opposite to FIG. 7(d).

[0122] Time t2 is the time at which there is some movement of the substrate relative to the initial predetermined position, and time t3 is the time at which the bonding head is adjusted to compensate for the movement of the substrate. As seen in FIG. 4, in an exemplary embodiment, times t2 and t3 occur when, in response to the movement of the substrate, all the positions of the four exemplary bonding heads BH1, BH2, BH3, and BH4 are adjusted simultaneously. Thus, FIGS. 6(a) - 6(e) show examples of time t2 when the substrate has moved, and FIGS. 7(a) - 7(e) show examples of time t3 when all the bonding heads have been repositioned to compensate for the moment of the substrate.

[0123] Throughout the figures, solid lines represent the current position of the components, and dashed lines represent the original position of the components. As shown in FIGS. 6(a) to 6(e), at time t2, a disturbance occurs such that the substrate 138 moves in the X direction. As shown in FIGS. 6(a), 6(d), and 6(e), the dashed lines of the substrate 138 indicate where the substrate was previously placed, and the solid lines indicate where the substrate 138 was placed after the disturbance. However, in this example, the disturbance is only in the X direction and tilt (θy). Therefore, FIGS. 6(a), 6(d), and 6(e) show the change in the distance 158 in the X direction, while FIGS. 6(b) and 6(c) do not show a change because there was no movement in the Y or Z direction at time t2. At time t2, the position of the bonding head has not yet been adjusted. Therefore, as shown by the solid lines in FIGS. 5(a) to 5(e), all the bonding heads BH1, BH2, BH3, and BH4 are shown in the same position. FIGS. 6(a), 6(d), and 6(e) show that, before the position of the bonding head is adjusted, due to the movement of the substrate 138 in the X direction, the positions of the target chip positions 150a, 150b, 150c, and 150d no longer match the corresponding chips 124a, 124b, 124c, and 124d in the X direction. On the other hand, since there is no movement in the Y direction in this example, FIGS. 6(b) and 6(c) show that in the Y direction, the positions of the target chip positions 150a, 150b, 150c, and 150d still match the corresponding chips 124a, 124b, 124c, and 124d. Although only the X-direction disturbance is shown for simplicity, the disturbance can occur in any of the above-mentioned directions, namely, X, Y, Z, tilt, tip, and rotation.

[0124] Referring to FIGS. 7(a) to 7(e), as described above, these figures show the time t3 when the bonding head was adjusted to compensate for the movement of the substrate shown in FIGS. 6(a) to 6(e). The dashed lines in FIGS. 7(a) to 7(e) represent the original positions of the bonding head and the substrate, and the solid lines represent the current positions. As shown in FIGS. 7(a), 7(d), and 7(e), all of the bonding heads BH1, BH2, BH3, and BH4 in the exemplary embodiment have been moved the same distance 158 in the X direction to compensate for the movement of the substrate in the X direction that occurred at time t2. In the exemplary embodiment, since the substrate 138 was disturbed only in the X direction, FIG. 7(b) does not show the movement of the bonding heads BH2 and BH3 in the Y direction. Each of the bonding heads BH1, BH2, BH3, and BH4 has moved in the X direction by the same amount as the substrate moved at time t2, but in the opposite direction, so that the chips 124a, 124b, 124c, and 124d are now realigned with the corresponding target chip positions 150a, 150b, 150c, and 150d in the X direction.

[0125] Also, as shown in FIG. 7(e), in addition to the adjustment X-direction movement, the bonding head BH1 of this embodiment moves toward the bonding surface 140 in the Z direction at time t3, and all the other bonding heads (BH2, BH3, BH4) do not change in the Z direction. As described above, one advantage of the method described herein is to solve the chip misalignment that occurs in the inevitable situation where the chips on the bonding head contact the bonding surface at slightly different times (on the scale of nanoseconds to milliseconds). Therefore, as the bonding method progresses where BH1 contacts first, followed by BH2, then BH3, and then BH4, different Z-direction change rates are shown. This order is selected as an exemplary embodiment, and the method described herein can be applied to any contact order and any number of bonding heads.

[0126] The updated position information of the substrate may be obtained by three or more sensors that measure the position and orientation of the substrate chuck. That is, as described above, the updated position information may include changes in the X-direction position of the substrate, changes in the Y-direction position of the substrate, changes in the tilt position of the substrate, changes in the tip position of the substrate, and changes in the rotational position of the substrate. The sensors sense the new positions in all of these aspects, and this information is provided to the controller. The controller may then calculate the necessary corrective adjustments of the bonding head required to cancel out the position changes of the substrate. The sensors can detect the updated position of the substrate every 0.1 - 1 ms to 0.5 - 1 s. The corresponding adjustments of the bonding head can be made every 0.2 milliseconds (ms) to 10 seconds (s). That is, throughout the entire period of steps S306 and S308, repositioning can be performed every 2 ms to 2 s. This corresponds to 2 - 1000 adjustments of the bonding head in the bonding process.

[0127] Figures 8(a) - 8(e) show different schematic views of the bonding head and substrate positions at time t4 that occur when one tip carried by one bonding head contacts the bonding surface 140 and the other tip carried by the other bonding head has not yet contacted the bonding surface. Figure 8(a) is a schematic top view of the bonding head and substrate corresponding to time t4 of Figure 4. Figure 8(b) is a schematic side view of the YZ plane of the bonding head and substrate at time t4. Figure 8(c) is a schematic side view of the YZ plane of the bonding head and substrate on the opposite side of Figure 8(b). Figure 8(d) is a schematic side view of the XZ plane of the bonding head and substrate at time t4. Figure 8(e) is a schematic side view of the XZ plane of the bonding head and substrate on the opposite side of Figure 8(d).

[0128] During the state represented by the third pattern 406, each control state of the bonding head stage 120 is a state in which each of the bonding head stages is under motion control, taking into account the displacement of the product substrate 138 on the product substrate chuck 136 during the initial contact period IC (IC1 of BH1 and IC2 of BH2). During the initial contact period IC, the chip 124 begins to contact the product substrate 138. Due to the friction between the product substrate 138 and the chip 124, the effectiveness of the motion control of the bonding head stage 120 in the plane of the bonding interface decreases. This initial contact period IC can be detected by an increase in the residual force in the Z direction. Detecting the start of the initial contact period IC in a high-speed moving bonding system can be difficult. The end of the initial contact period IC is defined as when the residual force applied in the Z direction by the bonding head stage 120 is greater than threshold value 2. Threshold value 2 can be determined by the noise limit of the system where the residual force can be reliably detected. Threshold value 2 can also be determined based on when the shear stress resulting from performing motion control is too high and may cause damage to one or both of the chip 102 and the product substrate. The timing chart of FIG. 4 shows the case where time t4 occurs at the end of the initial contact IC1. In the illustrated embodiment, at time t4, while the chip carried by the first bonding head BH1 is in contact with the bonding surface 140, the chips carried by the other bonding heads BH2, BH3, BH4 are not yet in contact with the bonding surface 140. When the chip is reliably in contact with the bonding surface 140, the steps of alternately receiving the updated position information of the substrate chuck and repositioning the first bonding head based on the received updated position information end. That is, there is no further adjustment of the position of the bonding head in contact with the bonding surface. Thus, in the exemplary embodiment, at time t4, the position of the first bonding head BH1 can no longer be adjusted, and the chip attempts to follow the position and orientation of the stage, but the actual relative movement of the chip with respect to the substrate may be impossible.Over the duration of the IC1, an increase in the total residual Z force is observed. When the total residual Z force exceeds a predetermined threshold (threshold 2), it is determined that BH1 is in contact with the product substrate 138. BH1 stops adjusting the position of the chip at any location on the product substrate and transitions to force-moment control. That is, the steps of alternately receiving new position information of the substrate chuck and repositioning the bonding head based on that information for the specific bonding head with which the chip has contacted the bonding surface are no longer executed. However, at the same time, the positions of all bonding heads that are not yet in contact with the bonding surface continue to be adjusted based on the movement of the substrate. The substrate can continue to move or change its orientation after the chip has contacted the bonding surface. Therefore, there is no longer a need to adjust the bonding head carrying the chip that is already in contact with the bonding surface, but the remaining bonding heads may continue to require adjustment. When the chip makes contact, it is identified by measuring the residual force in the Z direction, which will be explained in more detail below with respect to FIG. 21.

[0129] The time t4 shown in FIGS. 8(a) to 8(e) is the moment when the first bonding head BH1 starts to contact the bonding surface 140, and no disturbance has occurred yet. This is identified when the total residual Z force or the total chip (tip)-tilt residual moment begins to increase in magnitude due to the initial contact. Therefore, in FIGS. 8(a) to 8(e), compared with the time t3 shown in FIGS. 7(a) to 7(e), the change in position is only the movement of the first bonding head BH1 in the Z direction. As also shown in FIG. 4, when a chip carried by one of the bonding heads (for example, the first chip 124a carried by the first bonding head BH1) contacts the bonding surface, the bonding head enters a new state represented by the end of the third pattern 406 in FIG. 4. As described in the key of FIG. 4, during the period of the initial contact IC1 represented by the third pattern 406, the first bonding head BH1 can no longer move (that is, it can no longer move in X, Y, Z, tilt, tip, rotation), but the initial contact force (total residual Z force) or the total residual moment over the short duration IC1 begins to increase in magnitude, and the contact of the chip with the substrate is established. Over the duration of the initial contact period IC1, an increase in the total residual Z force is seen, and when it exceeds a predetermined threshold value (threshold value 2), it is determined that BH1 is in contact with the substrate, and BH1 stops adjusting any position of the chip relative to the substrate and shifts to force moment control.

[0130] Figs. 9(a) to 9(g) show schematic views of different positions of the bonding head and the substrate at time t5 that occur when the substrate moves after any one of the chips contacts the bonding surface and the other chips have not yet contacted the bonding surface. Fig. 9(a) is a schematic top view of the bonding head and the substrate corresponding to time t5 in Fig. 4. Fig. 9(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t5. Fig. 9(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to Fig. 9(b). Fig. 9(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t5. Fig. 9(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to Fig. 9(d). Fig. 9(f) of Fig. 18 is a schematic side view of the bonding head and the substrate in the XZ plane showing the tilt (θY) of the product substrate in the first direction at time t5, and this tilt can be, for example, a reaction to the first chip 124a that contacts the product substrate 138. Note that the chip chuck of BH1 is in a distorted state due to the tilt of the substrate and the stationary state of the chip chuck. In Fig. 9(f) of Fig. 18, the distortion is exaggerated as can be seen in the figure, and the actual distortion is very small. Fig. 9(g) of Fig. 18 is a schematic side view on the side opposite to Fig. 9(f) of Fig. 18 showing that the product substrate tilts.

[0131] Figures 10(a) to 10(e), 10(f) and 10(g) of FIG. 18 show schematic views of different positions of the bonding head and the substrate at time t6, which occur when the bonding head having chips not in contact with the bonding surface moves in response to the movement of the substrate occurring at time t5. FIG. 10(a) is a schematic top view of the bonding head and the substrate corresponding to time t6 in FIG. 4. FIG. 10(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t6. FIG. 10(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that of FIG. 10(b). FIG. 10(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t6. FIG. 10(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that of FIG. 10(d). 10(f) of FIG. 18 is a schematic side view of the bonding head and the substrate in the XZ plane showing the product substrate still tilted in the first direction at time t6, and the bonding head stages 120 of the bonding heads (BH2, BH3, BH4) not in contact with the product substrate tilt the chip chuck in response to the tilt of the product substrate. 10(g) of FIG. 18 is a schematic side view on the side opposite to that of 10(f) of FIG. 18 showing the bonding head stages 120 of the bonding heads BH3 and BH4 that tilt the chip chuck.

[0132] The timing chart of FIG. 4 shows the case when times t5 and t6 occur. In the illustrated exemplary embodiment, at time t5, the substrate 138 moves. The response of the bonding head to the movement of the substrate occurs at time t6. Since the chips (e.g., 124b, 124c, 124d) carried by the bonding heads (e.g., BH2, BH3, BH4) are not yet in contact with the bonding surface 140, at time t6, the step of adjusting the positions of the bonding heads BH2, BH3, BH4 to cancel out the movement of the substrate that occurred at time t5 is still executed. However, at time t4, since the chip 124a carried by the bonding head BH1 is already in contact with the bonding surface, the bonding head BH1 does not move at time t6 in response to the movement of the substrate that occurred at time t5. The simultaneous states of the bonding heads are shown in FIG. 4. As can be seen in FIG. 4, at the end of time t4, the first bonding head BH1 is at the end of the state represented by the third pattern 406 with no movement of the bonding head, and during the initial contact period IC1, there may be an increase in the total residual Z force (the force by which the actuator of the bonding head stage 102 for BH1 conforms the chip to the substrate so that the chip conforms to the substrate) for BH1 that has established contact. This residual Z force excludes the force required to overcome elastic forces such as springs and flexures that assist the Z-direction movement of the BH by the bonding head stage. As also shown in FIG. 4 at the same times t5 and t6, the second bonding head BH2, the third bonding head BH3, and the fourth bonding head BH4 all remain in the state represented by the second pattern 404. That is, each of the bonding heads BH2, BH3, BH4 remains in the state where the bonding head has moved in response to the movement of the substrate. In short, only the bonding heads where the substrate moves at time t5 and the chips are not yet in contact with the substrate at time t6 are moved in consideration of the movement of the substrate.

[0133] Figures 9(a) - 9(e) and FIGS. 9(f) and 9(g) of FIG. 18 show what happens before time t6, at which the corresponding correction operations are applied to the bonding head, at time t5 when substrate movement has occurred. As can be best seen in FIGS. 9(a), 9(d), and 9(e), the substrate 138 has moved a distance 162 relative to the initial position in FIGS. 5(a) - 5(e). In the illustrated exemplary embodiment, the substrate is moving in the X direction or is tilted about the y-axis (θy). However, the substrate can move in the X, Y, and Z directions or can tip, tilt, or rotate. Each of the motions can occur alone or in any combination of motions including instances where all six motions occur at once. As shown in FIGS. 9(a), 9(d), 9(e), and FIG. 9(g) of FIG. 18, since the substrate 138 is moving in the X direction and tilting about the y-axis (θy), the positions of the tips that are not in contact with the bonding surface no longer coincide with the target bonding positions 150. In the illustrated embodiment, the second tip 124b, the third tip 124c, and the fourth tip 124d are no longer aligned with their respective target positions 150b, 150c, and 150d. However, despite the movement of the substrate, the tips that are in contact with the bonding surface remain at the correct target positions because they are fixed after contact. Thus, in the illustrated embodiment, the first tip 124a still coincides with the target position 150a. In practice, when one of the BH1s contacts the substrate at a location, this initial contact can induce tip-tilt motion of the substrate because the tip-tilt rotation axis of the substrate can be in a plane different from the substrate plane. This tip-tilt motion can appear as a position error, an attitude error, or both, observed by the substrate stage position sensor. These position errors observed by the substrate stage sensor can be converted and supplied as an offset to the bonding head controller that is not yet in contact with the substrate. As best shown in FIG. 9(f) of FIG. 18, the contact of the first tip 124a with the product substrate induces tilting of the product substrate 138.

[0134] Figures 10(a) to 10(e), 10(f), and 10(g) of FIG. 18 show what happens at time t6 when a corresponding correction operation is applied to a bonding head to which the chip has not yet made contact with the bonding surface. In the illustrated exemplary embodiment, the first bonding head BH1 is no longer repositioned based on the movement of the substrate. As can be seen by comparing FIGS. 10(a) and 10(e) with FIGS. 9(a) and 9(e), the position of the bonding head BH1 in the X direction does not change even when the substrate moves in the X direction at time t5. As described above, when the chip contacts the bonding surface 140, the steps of alternately receiving updated position information of the substrate chuck and repositioning the first bonding head based on the received updated position information are completed. However, as can be best seen in FIGS. 10(a), 10(d), and 10(e), the remaining bonding heads BH2, BH3, and BH4 have been moved in the X direction by the same distance 158 as the substrate has moved. Thus, as shown in FIG. 4, at time t6, each of the bonding heads BH2, BH3, and BH4 is still in a state represented by the pattern 404 in which the bonding head is moved in consideration of the movement of the substrate. At the same time, in the exemplary embodiment, as shown in FIG. 10(b), the second bonding head BH2 is moving downward in the Z direction close to the bonding surface, while the third bonding head BH3 and the fourth bonding head BH4 are not moving.

[0135] Figures 11(a) to 11(e), 11(f) and 11(g) of FIG. 18 show schematic views at different positions of the bonding head and the substrate at time t7, which occur when the second chip among the chips carried by one bonding head contacts the bonding surface 140 and the other chips carried by other bonding heads have not yet contacted the bonding surface. FIG. 11(a) is a schematic top view of the bonding head and the substrate corresponding to time t7 in FIG. 4. FIG. 11(b) is a schematic side view of the YZ plane of the bonding head and the substrate at time t6. FIG. 11(c) is a schematic side view of the YZ plane of the bonding head and the substrate on the side opposite to FIG. 11(b). FIG. 11(d) is a schematic side view of the XZ plane of the bonding head and the substrate at time t7. FIG. 11(e) is a schematic side view of the XZ plane of the bonding head and the substrate on the side opposite to FIG. 11(d). 11(f) and 11(g) of FIG. 18 are schematic side views of the XZ plane of the bonding head and the substrate, showing that the product substrate is tilted (θY) in the first direction while the bonding head is in contact with the product substrate at time t7.

[0136] The timing chart of FIG. 4 shows the case where time t7 occurs at the end of the initial contact period IC2. In the illustrated embodiment, at time t7, the chip carried by the second bonding head BH2 contacts the bonding surface 140, but the chips 124c and 124d carried by the bonding heads BH3 and BH4 have not yet contacted the bonding surface 140. The chip 124a carried by the first bonding head BH1 has previously contacted the bonding surface. Similar to the first chip 124a, when the second chip 124b contacts the bonding surface 140, the steps of alternately receiving the updated position information of the substrate chuck and repositioning the second bonding head based on the received updated position information are completed. That is, the position of the second bonding head BH2 that has contacted the bonding surface cannot be further adjusted. Thus, in this embodiment, at time t7, the position of the second bonding head BH2 is not adjusted even if the substrate moves. However, at the same time, the positions of all the bonding heads that are not in contact with the bonding surface (for example, the third bonding head BH3 and the fourth bonding head BH4) continue to be adjusted based on the movement of the substrate.

[0137] Specifically, the time t7 shown in FIGS. 11(a) to (e) and FIGS. 11(f) and 11(g) of FIG. 18 is the moment when the second bonding head BH2 contacts the bonding surface 140, and no disturbance has occurred yet. Therefore, in FIGS. 11(a) to (e), compared with the time t6 shown in FIGS. 10(a) to (e), the change in position is only the movement of the second bonding head BH2 in the Z direction. In the illustrated exemplary embodiment, since there is no movement of the substrate either, at this specific time t7, there is no X / Y movement of any bonding head with respect to time t6. Also, as shown in FIG. 4, when the second chip 124b carried by the second bonding head BH2 contacts the bonding surface, the second bonding head BH2 exits the state represented by the third pattern 406 in FIG. 4. As described in the key of FIG. 4, during the period represented by the third pattern 406, the second bonding head BH2 is still moving, but the residual force applied by the bonding head increases until a residual force exceeding the threshold value 2 is measured. Also, as shown in FIG. 4, prior to time t7, the state of the first bonding head BH1 switches from the state represented by the third pattern 406 to the state represented by the fourth pattern 408. As described in the key of FIG. 4, during the period represented by the fourth pattern 408, there is no movement of the bonding head, but a constant low force is maintained in the Z direction. The control state of each bonding head stage 120 while in the state represented by the fourth pattern 408 is a constant low force in the Z direction without considering the disturbance of the position of the product substrate on the product substrate chuck, and is as low as zero moment control. The disturbance of the position of the product substrate is very small and can be absorbed as distortion in one or both of the chip chuck 122 and a part of the bonding head stage 120. BH1 switches from position control to force-moment control in Z-tip-tilt, BH1 holds the last set of currents applied at the end of IC1 and S306, and holds the last positions in X, Y, and θZ. In the Z-tip-tilt direction, force-moment control means that the actuator of the bonding head stage 120 controls the force and moments Mx and My supplied to the chip chuck in the Z direction.This may involve adjusting the moments of Mx and My to zero, a low constant value, or a low constant average value according to the reference force trajectory for the total Z force. The moment Mx is the x-component of the moment of the force applied by the bonding head stage to the chip chuck. The moment My is the y-component of the moment of the force applied by the bonding head stage 120 to the chip chuck 122. The total force trajectory in the Z direction is supplied to BH1 maintained at a small force magnitude. In one embodiment, the small force magnitude in the Z direction can be 0.1 N, 0.5 N, 1 N, 2 N, 5 N. The force trajectory in the Z direction can be a series of values that ultimately reach a small force trajectory. The force trajectory can be critically damped, overdamped, or underdamped. This relatively low force (small force magnitude) is sufficient to maintain an incomplete bond between the chip and the bonding surface, but is insufficient to completely bond the entire surface area of the chip to the bonding surface.

[0138] Figures 12(a) to (e) and 12(f), 12(g) of FIG. 19 show schematic diagrams of different positions of the bonding head and the substrate at time t8 that occur when the substrate moves after two chips come into contact with the bonding surface and the other chips are not yet in contact with the bonding surface. FIG. 12(a) is a schematic top view of the bonding head and the substrate corresponding to time t8 in FIG. 4. FIG. 12(b) is a schematic side view of the YZ plane of the bonding head and the substrate at time t8. FIG. 12(c) is a schematic side view of the YZ plane of the bonding head and the substrate on the opposite side to FIG. 12(b). FIG. 12(d) is a schematic side view of the XZ plane of the bonding head and the substrate at time t8. FIG. 12(e) is a schematic side view of the XZ plane of the bonding head and the substrate on the opposite side to FIG. 12(d). 12(f), 12(g) of FIG. 19 are schematic side views of the XZ plane of the bonding head and the substrate showing that the product substrate tilts (θY) in the second direction after the bonding head contacts the product substrate at time t8. Note that the chip chucks of BH1 and BH2 are in a strained state due to the tilt of the substrate and the stationary state of the chip chuck. In 12(f) of FIG. 19, the strain is exaggerated as can be seen in the figure, and the actual strain is very small.

[0139] Figs. 13(a) to 13(e), 13(f) and 13(g) of Fig. 19 show schematic views with different positions of the bonding head and the substrate at time t9, which occur when the bonding head having chips not in contact with the bonding surface moves in response to the movement of the substrate occurring at time t8. Fig. 13(a) is a schematic top view of the bonding head and the substrate corresponding to time t9 in Fig. 4. Fig. 13(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t9. Fig. 13(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to Fig. 13(b). Fig. 13(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t9. Fig. 13(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to Fig. 13(d). 13(f) and 13(g) of Fig. 19 are schematic side views of the bonding head and the substrate in the XZ plane showing that the product substrate is tilted (θY) in the second direction at time t9. Fig. 13(g) of Fig. 19 shows the bonding head stage of the bonding heads (BH3 and BH4) not in contact with the product substrate that tilts the chip chuck in response to the tilt of the product substrate.

[0140] The timing chart of FIG. 4 shows the case where times t8 and t9 occur. In the illustrated exemplary embodiment, at time t8, the substrate 138 moves. The response of the bonding head to the movement of the substrate occurs at time t9. Since the chips (e.g., 124c, 124d) carried by the bonding heads (e.g., BH3, BH4) are not yet in contact with the bonding surface 140, at time t9, the step of adjusting the positions of the bonding heads BH3 and BH4 is still executed to cancel out the movement of the substrate that occurred at time t8. However, since the chip 124a carried by the bonding head BH1 and the chip 124b carried by the second bonding head BH2 are already in contact with the bonding surface, at time t9, the bonding head BH1 and the bonding head BH2 do not move in response to the movement of the substrate that occurred at time t8. The simultaneous state of the bonding heads is shown in FIG. 4. As shown in FIG. 4, at times t8 and t9, the first bonding head BH1 is in the state shown in the fourth pattern 408 where there is no movement of the bonding head and the constant force in the Z direction is small. At time t7, as also shown in FIG. 4, the second bonding head BH2 is at the end of the state represented by the third pattern 406, where the bonding head is still under motion control, but the amount of the residual force in the Z direction has changed due to the initial contact. Finally, FIG. 4 shows that the third bonding head BH3 and the fourth bonding head BH4 are still in the state represented by the second pattern 404. That is, the bonding heads BH3 and BH4 are still in the state where the bonding heads are moved in response to the movement of the substrate. In short, at time t8, the substrate moves, and at time t9, only the bonding heads whose chips are not yet in contact with the substrate move in consideration of the movement of the substrate.

[0141] Figures 12(a) to 12(e), 12(f), and 12(g) of FIG. 19 show what occurs before time t9 when the corresponding correction operations are applied to the bonding heads BH3 and BH4 at time t8 when substrate movement occurs. As can be best seen in FIGS. 12(a), 12(d), and 12(e), the substrate 138 has moved a distance 164 relative to the initial position in FIGS. 5(a) to 5(e). FIGS. 12(f) and 12(g) of FIG. 19 show the tilt of the product substrate. In the illustrated exemplary embodiment, the substrate moves only in the X direction and the tilt direction. However, the substrate may move in the X, Y, and Z directions, or may tip, tilt, or rotate. Each of the motions can occur alone or in any combination of motions including instances where all six motions occur at once. As shown in FIGS. 12(a) and 12(d), when the substrate 138 moves in the X direction, the tips that are not in contact with the bonding surface become misaligned with the target bonding positions 150. In the illustrated embodiment, the third tip 124c and the fourth tip 124d are no longer aligned with their respective target positions 150c and 150d. However, the tips that are in contact with the bonding surface remain at the correct target positions despite the movement of the substrate because the positions of the tips are fixed after contact. Thus, in the illustrated embodiment, the first tip 124a and the second tip 124b still remain aligned with the target positions 150a and 150b.

[0142] Figures 13(a) to 13(e), 13(f) and 13(g) of FIG. 19 show what happens at time t9 when a correction operation corresponding to a bonding head to which the chip has not yet contacted the bonding surface is applied. In the illustrated exemplary embodiment, the first bonding head BH1 and the second bonding head BH2 are no longer repositioned based on the movement of the substrate. Thus, as can be seen by comparing FIGS. 13(a) and 13(e) with FIGS. 12(a) and 12(e), even if the substrate moves in the X direction at time t8, the X-direction positions of the bonding heads BH1 and BH2 do not change. As described above, when the chip contacts the bonding surface 140, the steps of alternately receiving the updated position information of the substrate chuck and repositioning the bonding heads (for example, the bonding head BH1 and the bonding head BH2) based on the received updated position information are completed. However, as can be best seen in FIGS. 13(a) and 13(d), all of the remaining bonding heads BH3 and BH4 have moved in the X direction by the same distance 158 as the substrate has moved. Thus, as shown in FIG. 4, at time t9, each of the bonding heads BH3 and BH4 is still in a state represented by the pattern 404 in which the bonding head is moved in consideration of the movement of the substrate. At the same time, in the exemplary embodiment, as shown in FIG. 13(c), the third bonding head BH3 is moving downward in the Z direction close to the bonding surface, while the fourth bonding head BH4 is not moving. As seen in FIG. 13G, the bonding head stages 120 of the bonding heads BH3 and BH4 tilt the chip chuck 122.

[0143] Figs. 14(a) to (e), 14(f), and 14(g) of Fig. 19 show schematic views of different positions of the bonding head and the substrate at time t10 when the third chip 124c carried by the third bonding head BH3 contacts the bonding surface 140 and the remaining fourth chip 124d carried by the fourth bonding head BH4 has not yet contacted the bonding surface. Fig. 14(a) is a schematic top view of the bonding head and the substrate corresponding to time t10 in Fig. 4. Fig. 14(b) is a schematic side view of the YZ plane of the bonding head and the substrate at time t10. Fig. 14(c) is a schematic side view of the YZ plane of the bonding head and the substrate on the side opposite to Fig. 14(b). Fig. 14(d) is a schematic side view of the XZ plane of the bonding head and the substrate at time t10. Fig. 14(e) is a schematic side view of the XZ plane of the bonding head and the substrate on the side opposite to Fig. 14(d). Figs. 14(f) and 14(g) of Fig. 19 are schematic side views of the XZ plane of the bonding head and the substrate showing that the product substrate is tilted (θY) in the second direction at time t10. Fig. 14(g) of Fig. 19 shows the bonding head BH3 in contact with the product stage.

[0144] The timing chart of FIG. 4 shows the case where time t10 occurs. In the illustrated exemplary embodiment, at time t10, the chip 124c carried by the third bonding head BH3 contacts the bonding surface 140, while the chip 124d carried by the fourth bonding head BH4 has not yet contacted the bonding surface 140. The chip 124a carried by the first bonding head BH1 and the chip 124b carried by the second bonding head BH2 have previously contacted the bonding surface. Similar to the first chip 124a and the second chip 124b, when the third chip 124c contacts the bonding surface 140, the steps of alternately receiving the updated position information of the substrate chuck and repositioning the third bonding head BH3 based on the received updated position information end. That is, the position of the third bonding head BH3 that has contacted the bonding surface cannot be further adjusted. Therefore, in this embodiment, at time t10, even if the substrate moves, the position of the third bonding head BH3 will not be adjusted. However, at the same time, the positions of the remaining bonding heads BH4 that have not yet contacted the bonding surface continue to be adjusted based on the movement of the substrate.

[0145] Specifically, the time t10 shown in FIGS. 14(a) to (e), 14(f), and 14(g) of FIG. 19 is the moment when the third bonding head BH3 contacts the bonding surface 140, and no disturbances have occurred yet. Therefore, in FIGS. 13(a) to 13(e), compared with the time t9 shown in FIGS. 13(a) to 13(e), the change in position is only the movement of the third bonding head BH3 in the Z direction. In the illustrated exemplary embodiment, since there is no movement of the substrate either, at this specific time t10, there is no X / Y movement of any bonding head with respect to time t9. Also, as shown in FIG. 4, when the third chip 124c mounted on the third bonding head BH3 begins to contact the bonding surface, the third bonding head BH3 enters a new state represented by the third pattern 406 in FIG. 4. That is, during the initial contact period IC3 represented by the third pattern 406, the third bonding head BH3 still moves, but the residual force applied by the bonding head begins to increase. As also shown in FIG. 4, immediately before time t10, the state of the first bonding head BH1 is still the state represented by the fourth pattern 408, and the second bonding head BH2 has also entered the state represented by the fourth pattern 408. As described above, during the period represented by the fourth pattern 408, there is still no movement of the bonding head, but a constant low force is maintained in the Z direction. Therefore, at time t10, both the first bonding head BH1 and the second bonding head BH3 apply relatively low forces to their respective chips, and this force is sufficient to maintain an incomplete bond between the chip and the bonding surface, but is insufficient to completely bond the entire surface area of the chip to the bonding surface.

[0146] Figures 15(a) to (e), 15(f), and 15(g) of FIG. 20 show schematic views of different positions of the bonding head and the substrate at time t11, which occur when there is movement of the substrate after the three chips (124a, 124b, 124c) come into contact with the bonding surface, and the fourth chip 124d has not yet come into contact with the bonding surface. FIG. 15(a) is a schematic top view of the bonding head and the substrate corresponding to time t11 in FIG. 4. FIG. 15(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t11. FIG. 15(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that of FIG. 15(b). FIG. 15(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t11. FIG. 15(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that of FIG. 15(d). FIGS. 15(f) and 15(g) are schematic side views of the bonding head and the substrate in the XZ plane at time t11, showing that the product substrate tilts (θY) in the first direction in response to the chips coming into contact with the product substrate.

[0147] Figures 16(a) to (e), 16(f), and 16(g) of FIG. 20 are schematic diagrams of the positions of the bonding head and the substrate at time t12, which occur when the fourth bonding head BH4 having the fourth chip 124d that is not in contact with the bonding surface moves in response to the movement of the substrate at time t11. FIG. 16(a) is a schematic top view of the bonding head and the substrate corresponding to time t12 in FIG. 4. FIG. 16(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t12. FIG. 16(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to that of FIG. 16(b). FIG. 16(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t12. FIG. 16(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to that of FIG. 16(d). FIGS. 16(f) and 16(g) of FIG. 20 are schematic side views of the bonding head and the substrate in the XZ plane according to the embodiment, showing that at time t12, the product substrate 138 tilts (θY) in the first direction, and the bonding head stage of the bonding head moves the chip chuck so as to match the tilt of the product substrate.

[0148] The timing chart of FIG. 4 shows the case where times t11 and t12 occur. In the illustrated exemplary embodiment, at time t11, the substrate 138 moves. The response of the bonding head BH4 to the movement of the substrate occurs at time t12. Since the chip 124d carried by the fourth bonding head BH4 has not yet contacted the bonding surface 140, at time t12, in order to cancel out the movement of the substrate that occurred at time t11, the step of adjusting the position of the bonding head BH4 is still executed. However, since the chips 124a carried by the bonding head BH1, the chips 124b carried by the second bonding head BH2, and the chips 124c carried by the third bonding head BH3 have already contacted the bonding surface, the bonding heads BH1, BH2, and BH3 do not move at time t12 in response to the movement of the substrate that occurred at time t11. The simultaneous states of the bonding heads are shown in FIG. 4. As shown in FIG. 4, at times t11 and t12, the first bonding head BH1 and the second bonding head BH2 are in the state shown in the fourth pattern 408 where there is no movement of the bonding head and the constant force in the Z direction is small. As also shown in FIG. 4, at time t10, the third bonding head BH3 is at the end of the state represented by the third pattern 406 where the bonding head is still moving but the residual force in the Z direction is increasing. Finally, FIG. 4 shows that the fourth bonding head BH4 is still in the state represented by the second pattern 404. That is, the bonding head BH4 is still in the state where the bonding head is moved in consideration of the movement of the substrate. In short, at time t11, the substrate moves, and at time t12, only the fourth bonding head BH4 moves in consideration of the movement of the substrate because the fourth bonding head BH4 is the only remaining bonding head whose chip has not yet contacted the substrate.

[0149] Figures 15(a)-(e), 15(f), and 15(g) of FIG. 20 show what occurs prior to time t12 at which the corresponding correction operation is applied to the fourth bonding head BH4 at time t11 when movement of the substrate has occurred. As can be best seen in FIGS. 15(a), 15(d), and 15(e), the substrate 138 has moved a distance 166 relative to the initial position in FIGS. 5(a)-(e). In the illustrated embodiment, the substrate has moved only in the X direction and the tilt direction θy. However, the substrate may move in the X, Y, and Z directions, or tip, tilt, or rotate. Each of the motions may occur alone or in any combination of motions including instances where all six motions occur at once. As shown in FIGS. 15(a) and 15(d), when the substrate 138 moves in the X direction, the fourth tip 124d that is not in contact with the bonding surface becomes misaligned with the target bonding position 150d. However, since the position of the tip that has contacted the bonding surface is fixed after contact, it remains at the correct target position even when the substrate moves. Thus, in the illustrated embodiment, the first tip 124a, the second tip 124b, and the third tip 124c still remain aligned with the target positions 150a, 150b, and 150c.

[0150] Figures 16(a) to (e), 16(f) and 16(g) of FIG. 20 show the operations at time t12 when corresponding correction operations are performed on the fourth bonding head BH4 where the chip 124d is not in contact with the bonding surface. In the illustrated exemplary embodiment, the first bonding head BH1, the second bonding head BH2, and the third bonding head BH3 are no longer repositioned based on the movement of the substrate. Therefore, as can be seen by comparing FIGS. 16(a), 16(d), 16(e) with FIGS. 15(a), 15(d), 15(e), even if the substrate moves in the X direction at time t11, the X-direction positions of the bonding heads BH1, BH2, and BH3 do not change. As described above, when the chip contacts the bonding surface 140, the steps of alternately receiving the updated position information of the substrate chuck and repositioning the bonding head (for example, bonding head BH1, bonding head BH2, bonding head BH3) based on the received updated position information are completed. However, as most clearly seen in FIGS. 16(a) and 16(d), the remaining bonding head BH4 has moved in the X direction by the same distance 166 as the substrate has moved. Therefore, as shown in FIG. 4, at time t12, the bonding head BH4 is still in the state represented by the pattern 404 in which the bonding head is moved in consideration of the movement of the substrate. At the same time, in the exemplary embodiment, as shown in FIG. 16(b), the fourth bonding head BH4 is moving downward in the Z direction close to the bonding surface. As shown in 16(g) of FIG. 20, the bonding head stage 120 tilts the chip chuck 120 of the bonding head BH4 so that the fourth chip is positioned at the fourth target chip position 150d.

[0151] Figures 17(a) to (e), 17(f) and 17(g) of FIG. 20 show schematic views of different positions of the bonding head and the substrate at time t13, which occur when the fourth chip 124d carried by the fourth bonding head BH4 contacts the bonding surface 140 while all other chips 124a, 124b, 124c remain in contact with the bonding surface. FIG. 17(a) is a schematic top view of the bonding head and the substrate corresponding to time t13 in FIG. 4. FIG. 17(b) is a schematic side view of the bonding head and the substrate in the YZ plane at time t13. FIG. 17(c) is a schematic side view of the bonding head and the substrate in the YZ plane on the side opposite to FIG. 17(b). FIG. 17(d) is a schematic side view of the bonding head and the substrate in the XZ plane at time t13. FIG. 17(e) is a schematic side view of the bonding head and the substrate in the XZ plane on the side opposite to FIG. 14(d). 17(f) and 17(g) of FIG. 20 are schematic side views of the bonding head and the substrate in the YZ plane showing that at time t13, the product substrate is tilted (θY) in the first direction and the chip has contacted the product substrate.

[0152] The timing chart of FIG. 4 shows the case where time t13 occurs. In the illustrated embodiment, at time t13, the chip 124d carried by the fourth bonding head BH4 is in contact with the bonding surface 140. The chip 124a carried by the first bonding head BH1, the chip 124b carried by the second bonding head BH2, and the chip 124c carried by the third bonding head BH3 were previously in contact with the bonding surface. Similar to the first chip 124a, the second chip 124b, and the third chip 124c, when the fourth chip 124d contacts the bonding surface 140, the steps of alternately receiving the updated position information of the substrate chuck and repositioning the fourth bonding head BH4 based on the received updated position information are completed. That is, it becomes impossible to further adjust the position of the fourth bonding head BH4 where the chip has contacted the bonding surface. Therefore, in the present embodiment, at time t13, the position of the fourth bonding head BH4 is no longer adjusted even if the substrate moves.

[0153] As described above, the time t13 shown in FIGS. 17(a) to 17(e) is the moment when the fourth bonding head BH4 contacts the bonding surface 140. In the illustrated embodiment, since the fourth bonding head BH4 is the final bonding head, after the fourth chip 124d contacts the bonding surface 140, there is no longer a need to adjust the position of any of the bonding heads to compensate for changes in the position of the substrate. Therefore, in FIGS. 17(a) to 17(e), it is compared with the time t12 shown in the figures. Therefore, in FIGS. 17(a) to 17(e), compared with the time t12 shown in FIGS. 16(a) to (e), the position of the bonding head does not change except that the fourth bonding head BH4 moves so that the fourth chip 124d contacts the bonding surface 140. Even if the substrate moves, none of the bonding heads move, so at this specific time t13, there is no X / Y movement of any of the bonding heads with respect to time t12. As also shown in FIG. 4, when the fourth chip 124d carried by the fourth bonding head BH4 contacts the bonding surface, the fourth bonding head BH4 enters a new state represented by the third pattern 406 in FIG. 4. That is, during the period represented by the third pattern 406, the fourth bonding head BH4 is no longer moved (i.e., no longer moved in the X, Y, Z, tilt, tip, rotation directions), but the force applied by the bonding head changes. Also, as shown in FIG. 4, immediately before time t13, the states of the first bonding head BH1 and the second bonding head BH2 are still the states represented by the fourth pattern 408, and the third bonding head BH3 is also in the state represented by the fourth pattern 408. As described above, during the period represented by the fourth pattern 408, there is still no movement of the bonding head, but a constant low force is maintained in the Z direction. Therefore, at time t13, all of the first bonding head BH1, the second bonding head BH2, and the third bonding head BH3 apply a relatively low force to their respective chips, and this force is sufficient to maintain an incomplete bond between the chip and the bonding surface, but is insufficient to completely bond the entire surface area of the chip to the bonding surface.

[0154] Figure 4 further shows the time t14 when the fourth bonding head BH4 has completed the state represented by the third pattern 406 and entered the state represented by the fourth pattern 408 where there is still no movement of the bonding head but a constant low force is maintained in the Z direction. For this reason, at time t14, all the bonding heads are in the same state. That is, all the chips are in contact with the bonding surface, all the bonding heads are stationary, all the bonding heads apply a relatively low force in the Z direction, and that force is sufficient to maintain an incomplete bond between the chip and the bonding surface but insufficient to completely bond the entire surface area of the chip to the bonding surface.

[0155] In particular, as also shown in Figure 4, time t15 is when all the bonding heads switch from the state represented by the fourth pattern 408 to a new state represented by the fifth pattern 410. The fifth pattern in Figure 4 represents a state where there is still no movement of the bonding head but a much higher bonding force is applied in the Z direction to the chips held by the bonding heads. Each control state of the bonding head stage 120 while in the state represented by the fifth pattern 410 is such that each of the bonding head stages has a high constant force in the Z direction and low or zero moment control without considering the disturbance of the position of the product substrate on the product substrate chuck. The force applied during the state represented by the fifth pattern 410 is 2 to 20 times higher than the force applied during the state represented by the fourth pattern 408. This force is sufficient to completely bond the chips to the bonding surface. In particular, at t14 for all the bonding heads simultaneously, a switch occurs. That is, although all other states may last for different times for each bonding head, the timing is controlled such that all the bonding heads simultaneously switch from the state represented by the fourth pattern 408 to the state represented by the fifth pattern 410. In other words, a relatively much stronger bonding force is applied to all the chips simultaneously. The bonding process ends at time tf when all the chips are completely bonded to the bonding surface and the force applied by each bonding head is no longer applied.

[0156] Figure 21(a) is a timing chart of the X-direction position control signal of the four bonding heads and the substrate measurement position in the present embodiment. The X-direction position control signal is a signal sent by the controller to the bonding head stage 120. The X-axis represents the same period as the timing chart of FIG. 4. The Y-axis represents the X position. As shown in FIG. 21(a), in the present embodiment, during the period from the start to the end of the bonding process, the substrate moves sporadically in the X direction by a relatively small amount. FIG. 21(a) shows a ramp period during which the substrate / bonding head moves to the overall predetermined initial X-direction position with respect to the reference point for each of the bonding head and the substrate. At the same time, the bonding head moves toward the substrate in the Z direction.

[0157] Figure 21(b) shows a timing chart of the Z-direction positions of the four bonding heads. The X-axis represents the same period as the timing chart of FIG. 4. The Y-axis represents the Z position. As shown in FIG. 21(b), in the present embodiment, the bonding head moves in the X direction (FIG. 21(a)) and at the same time moves toward the substrate. When the bonding head reaches a predetermined Z-position threshold (threshold 1), the state of the bonding head switches from operation control that does not consider the position of the substrate to operation control that considers the position of the substrate. Threshold 1 can be a Z position that is a small gap / distance from the product substrate. This gap can be 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, 100 μm. The non-uniformity of the uniform line in FIG. 21(a) indicates the adjustment made to the X-position control signal as a result of the movement of the substrate in the X direction. For each bonding head, when the processor detects the intersection of the Z-position threshold (threshold 1), the bonding head operates in the control state represented by the second pattern 404.

[0158] FIG. 21(c) shows a timing chart of the total Z-direction force applied by the actuators of the four bonding heads (Z direction) of the embodiment. The X-axis represents the same period as the timing chart of FIG. 4. The Y-axis represents the total force (magnitude) applied in the Z direction by the actuators of the bonding head. The total Z-direction force is the sum of all the Z-direction force components of all the actuators for a particular bonding head. That is, since each bonding head has a plurality of actuators that move in a plurality of directions, the Z components of each actuator are combined so as to reach the total Z force. As shown in FIG. 21(c), in this embodiment, the total Z force steadily increases for each bonding head until the period in which the total Z force is kept constant is reached. In the state represented by the fourth pattern 408 of FIG. 4, there is a period in which the total Z force is kept constant. When the second threshold value (threshold value 2) is reached, it is determined that the state switches from the previous state (third pattern 406) to the fourth pattern 408.

[0159] Threshold 2 is shown in Fig. 21(d). Fig. 21(d) shows the timing chart of the residual force of the four bonding heads of the present embodiment. The X-axis represents the same period as the start timing chart of Fig. 4. The Y-axis represents the residual force. Since the bonding head includes a flexure and a spring that prevent all the forces of the actuator from being applied, the resulting actual force is the residual force. That is, the residual Z force received by the chip is the total Z force applied by all the actuators of the bonding head that carry the chip balanced with respect to the flexure / spring force. The excess Z force applied by the actuator of the bonding head that overcomes the flexure / spring force is the residual force. The controller can calculate the residual force based on the measured position of the bonding head and subtract the elastic force of the bonding head stage 120 based on the pre-calibration data and the measured position of the bonding head. When a predetermined residual Z force (threshold 2) is reached, it is determined that contact has occurred, and the Z force applied to the contacted chip is rapidly increased to a magnitude of a first force that is insufficient to completely bond the chip to the bonding surface. The magnitude of the first force is held constant when the chips contact, and is applied to each subsequent chip when they contact. When all the chips are in contact and held with the same total Z force and residual Z force, a magnitude of a second force is applied to all the chips simultaneously to completely bond the chips to the bonding surface. The magnitude of the second force is greater than the magnitude of the first force. The magnitude of the second force is 5 to 10 times greater than the magnitude of the first force.

[0160] Fig. 21(e) shows the same timing chart as Fig. 4. Since Fig. 21(e) is described in parallel with Figs. 21(a) to 21(d), the state of the bonding head can be easily confirmed on the same time axis shown in Figs. 21(a) to 21(d). By viewing Figs. 21(a) to 21(e) comprehensively, the state of the bonding head, the X position, the Z position, the total Z force, and the residual Z force at any point in time can be understood.

[0161] FIG. 21(a) is a chart showing the X position for illustrative purposes, and the same principle can be applied to any of the other five directions, namely, Y, Z, tilt, tip, and rotation. FIGS. 21(a)-(e) are intended to be understood together. Although no scale is shown for any axis, the timing of the horizontal axis is the same in all figures and is intended to show the correlated operation of the various functions of the bonding head. The scale of the values is not quantitative but is for a qualitative understanding of the behavior of the bonding head and the substrate.

[0162] FIG. 22 is a flowchart showing a part of the information flow of the bonding process 2300 in the tip bonding section 106 of the bonding system 100. The bonding process 2300 includes a first receiving step 2302a, a second receiving step 2304b, and a third receiving step 2304c. The first receiving step 2302a includes the processor 154 receiving a desired substrate position. The second receiving step 2302b includes the processor 154 receiving a desired bonding head position Di of the i-th bonding head BHi of the N bonding heads. The third receiving step 2302c includes the processor 154 receiving a measured tip position Ci of the tip 124 on the tip chuck 122 of the i-th bonding head BHi of the N bonding heads. The desired substrate position, the desired bonding head position, and the tip position may each include 1 to 6 coordinate positions.

[0163] The bonding process 2300 has a substrate position measuring step 2304a and a bonding head position measuring step 2304b for each bonding head BHi. Each bonding head BHi includes one or more sensors for measuring the relative position of the tip chuck of each bonding head BHi in 2 to 6 coordinates, and their positions are provided to the processor 154 as the measured bonding head position Mi for each tip chuck. The substrate position measuring step 2304a may include measuring the position of the product substrate chuck.

[0164] The bonding process 2300 includes a substrate position error estimation step 2306. In the substrate position error estimation step 2306, the processor 154 estimates the position of the substrate based on the measured substrate position, calibration data, the known relative positions of the sensors, the position and orientation of the substrate on the product substrate chuck, and the target chip position on the product substrate, and identifies the position of the bonding surface of the product substrate. Thereafter, the processor 154 compares the estimated position of the substrate with the desired substrate position to obtain the substrate position error ΔS in six directions. The substrate position measurement step 2304a and the substrate position error estimation step 2306 are repeatedly performed until the bonding process is completed. Typically, the substrate position error ΔS is initially large but decreases over time. The substrate position error ΔS is continuously acquired to take into account random and predictable disturbances. The substrate position error ΔS is then supplied to a position controller such as a proportional-integral-derivative (PID) controller to determine the adjustment signal that needs to be transmitted to the substrate positioning system. The bonding process 2300 includes a first transmission step 2312a in which the processor transmits the adjustment signal to the substrate positioning system.

[0165] The bonding process 2300 includes a Z-position estimation step 2308. The Z-position estimation step 2308 includes the step of the processor estimating a position Zi, which is the Z position of the chip chuck on BHi, based on the calibration data and the measured bonding head position Mi. The position Zi is compared with a threshold 1 in the first test step 2310. If the Z position is greater than the threshold 1, the bonding process 2300 proceeds to the second transmission step 2312b. If the Z position is not greater than the threshold 1, the bonding process 2300 proceeds to the first estimation step 2314. In the second transmission step 2312b for each bonding head BHi, the processor 154 determines an adjustment signal to be sent to the bonding head stage to adjust the position of the chip chuck based on the PID controller, the chip position Ci, the desired bonding head position Di, and the measured bonding head position Mi. Then, the processor sends the adjustment signal to the chip chuck of the bonding head BHi. Steps 2404b, 2308, 2310, 2312b are repeatedly performed until the result in the first test step 2310 is NO.

[0166] If the result in the first test step 2310 is NO, the processor executes the first estimation step 2314. The first estimation step 2314 includes, for each bonding head BHi, obtaining an adjustment signal Fi to be sent to the bonding head stage to adjust the position of the chip chuck using a PID controller, the chip position Ci, the desired bonding head position Di, the measured bonding head position Mi, and the substrate position error ΔS. After the first estimation step 2314, a second estimation step 2316 is executed by the processor. The second estimation step 2316 includes the processor estimating a residual force Ri of the bonding head BHi based on the adjustment signal Fi, the measured bonding head position Mi, and the calibration data.

[0167] The bonding process 2300 includes a second test step 2318 executed by a processor. The second test step 2318 includes the processor determining whether the residual force Ri of the bonding head BHi is greater than a threshold value 2. If the result of the second test step 2318 is NO, a third transmission step 2312c is executed, and if the result of the second test step 2318 is YES, a fourth transmission step 2312d is executed. The third transmission step 2312c includes the processor transmitting an adjustment signal Fi to the bonding head stage 120 of BHi. If the result of the first test step 2310 is NO, steps 2304b, 2314, 2316, 2318b are repeatedly performed until the result of the second test step 2318 becomes YES.

[0168] If the result of the second test step 2318 is YES, a fourth transmission step 2312d is executed. The fourth transmission step 2312d includes the processor transmitting a command to the bonding head stage 120 of the bonding head BHi and maintaining the force moment around the X-axis and Y-axis (Mx and My) low or zero while applying a low holding force FL. After the low holding force is sent to the bonding head BHi, the processor continuously executes a third test step 2320. The third test step includes determining whether all bonding heads are held at the low holding force FL for longer than a minimum low force holding time. If the result of the third test step 2320 is NO, the third test step 2320 is repeatedly executed periodically. If the result of the third test step 2320 is YES, a fourth transmission step 2312e is executed. The fourth transmission step 2322 includes transmitting a command to apply a high holding force having a low or zero force moment around the x-axis and y-axis (Mx and My) to the bonding head stage 120. After the fourth transmission step 2312e is executed during the high force holding time, all chips are released from the chip chuck, and all bonding heads are moved away from the product substrate chuck together with the bonding head stage.

[0169] After all the chips are completely bonded to the bonding surface, all of the bonded chips are released from the bonding head. That is, with one side of the chip bonded to the bonding surface, the bonding head can release the opposite side of the chip held by the bonding head. When released, the bonding process is complete. At this time, the bonding process can be repeated using more chips.

[0170] By implementing the bonding method described in this specification, alignment errors due to tilting or other disturbances to the substrate are eliminated or minimized. In particular, until the chip carried by the bonding head contacts the bonding surface, the position of each bonding head is adjusted based on the position of the substrate (substrate chuck), so the influence of substrate movement on alignment is eliminated or minimized. That is, if the substrate moves while the chip is approaching the bonding surface, it is countered by moving the bonding head that carries the chip.

[0171] After the process of bonding the chips to the bonding surface (which may include many cycles of bonding method 200 for bonding hundreds, thousands, or tens of thousands of chips) is completed, the product substrate 138 is removed from the chip bonding section 106, for example, by a transfer robot 126 or the like. Thereafter, the product substrate can be subjected to an annealing process (which may include one or both of heat and pressure) in which the hybrid bonding process is completed. The product substrate may be subjected to an additional process of adding additional chips to the product substrate before or after the annealing process. Next, the product substrate can be subjected to additional processes such as singulation, inspection, and encapsulation, which are used to manufacture a plurality of articles from the product substrate.

[0172] Not all of the operations described above in the general description or examples are required, and some of the specific operations may not be essential, and it should be noted that one or more additional operations may be performed in addition to those described. Further, the order in which the operations are listed is not necessarily the order in which they are performed. Although the above description has been presented in the context of a hybrid bonding process, other bonding processes may be used, such as soldering, flip-chip bonding, ball grid array bonding, or another process used to form multiple electrical connections between chips.

[0173] In the above description, with respect to specific embodiments, advantages, other advantages, and solutions to problems have been described. However, advantages, benefits, solutions to problems, and any features that may give rise to or make more prominent any advantage, benefit, or solution should not be construed as important, essential, or essential features of some or all of the claims in the claims.

[0174] The embodiments and examples described herein are intended to enable a general understanding of the structures of various embodiments. This specification and the examples do not comprehensively and inclusively describe all of the elements and features of the apparatus and system using the structures or methods described herein. Separate embodiments can also be provided in combination in a single embodiment, and conversely, for the sake of brevity, the various features described in the context of a single embodiment can be provided individually or in any sub-combination. Further, reference to a value specified in a range includes each and every value within that range. Many other embodiments will become apparent to those skilled in the art after reading this specification. Without departing from the scope of the present disclosure, structural substitutions, logical substitutions, or other changes can be made, and other embodiments can be used and derived from the present disclosure. Therefore, the present disclosure should be regarded as illustrative rather than restrictive.

Claims

1. A method for bonding chips, comprising: initially positioning a first bonding head holding a first chip at a first predetermined position relative to an initial position of a substrate chuck that supports a bonding surface; initially positioning a second bonding head holding a second chip at a second predetermined position relative to the initial position of the substrate chuck; alternately receiving updated position information of the substrate chuck and repositioning the first bonding head based on the received updated position information until the first chip contacts the bonding surface; alternately receiving updated position information of the substrate chuck and repositioning the second bonding head based on the received updated position information until the second chip contacts the bonding surface; bonding the first chip and the second chip to the bonding surface; A method characterized by comprising the above steps.

2. The step of alternately receiving the updated position information and repositioning the first bonding head until the first chip contacts the bonding surface is performed in a first period, The step of alternately receiving the updated position information and repositioning the second bonding head until the second chip contacts the bonding surface is performed in a second period, The first period and the second period overlap; The method according to claim 1, characterized in that.

3. The method according to claim 1, characterized in that the length of the first period is different from the length of the second period.

4. After the first chip contacts the bonding surface, operating the first bonding head to apply a first force in a direction toward the bonding surface to the first chip; After the second chip contacts the bonding surface, operating the second bonding head to apply a second force in a direction toward the bonding surface to the second chip; The method according to claim 1, further characterized by comprising the above steps.

5. After applying the first force and the second force, simultaneously operating the first bonding head and the second bonding head so that the first bonding head applies a third force in a direction toward the bonding surface to the first chip and the second bonding head applies a fourth force in a direction toward the bonding surface to the second chip The method according to claim 4, further characterized by comprising the above steps.

6. The magnitude of the third force is sufficient to completely bond the first chip to the bonding surface, The magnitude of the fourth force is sufficient to completely bond the second chip to the bonding surface. The method according to claim 5, characterized in that.

7. The magnitude of the third force is greater than the magnitude of the first force, The magnitude of the fourth force is greater than the magnitude of the second force, The method according to claim 5, characterized in that.

8. The magnitude of the first force is ±10% with respect to the magnitude of the second force, The magnitude of the third force is ±10% with respect to the magnitude of the fourth force, The method according to claim 5, characterized in that.

9. The magnitude of the third force is 10 times greater than the magnitude of the first force, The magnitude of the fourth force is 10 times greater than the magnitude of the second force, The method according to claim 5, characterized in that.

10. The magnitude of the first force is insufficient to completely bond the first chip to the bonding surface, The magnitude of the second force is insufficient to completely bond the second chip to the bonding surface, The method according to claim 4, characterized in that.

11. Initial positioning of a third bonding head holding a third chip at a third predetermined position with respect to the initial position of the substrate chuck; Receiving the updated position information of the substrate chuck and repositioning the third bonding head based on the received updated position information, alternately performing the above until the third chip contacts the bonding surface; The method according to claim 1, further comprising the above.

12. The step of alternately receiving the updated position information and repositioning the first bonding head until the first chip contacts the bonding surface is performed in a first period, The step of alternately receiving the updated position information and repositioning the second bonding head until the second chip contacts the bonding surface is performed in a second period, The step of alternately receiving the updated position information and repositioning the third bonding head until the third chip contacts the bonding surface is performed in a third period, The first period, the second period, and the third period overlap. The method according to claim 11, characterized in that.

13. After the first chip contacts the bonding surface, operating the bonding head to apply a first force in a direction toward the bonding surface to the first chip; After the second chip contacts the bonding surface, operating the second bonding head to apply a second force in a direction toward the bonding surface to the second chip; After the third chip contacts the bonding surface, operating the third bonding head to apply a third force in a direction toward the bonding surface to the third chip; The method according to claim 11, further comprising the above.

14. After applying the first force, the second force, and the third force, the first bonding head applies a fourth force in a direction toward the bonding surface to the first chip, the second bonding head applies a fifth force in a direction toward the bonding surface to the second chip, and the third bonding head applies a sixth force in a direction toward the bonding surface to the third chip, and simultaneously operating the first bonding head, the second bonding head, and the third bonding head; The method according to claim 13, further comprising the above.

15. The magnitudes of the first force, the second force, and the third force are each insufficient to completely bond the first chip, the second chip, and the third chip to the bonding surface; The magnitudes of the fourth force, the fifth force, and the sixth force are each sufficient to completely bond the first chip, the second chip, and the third chip to the bonding surface; The method according to claim 14, characterized by the above.

16. When the first chip contacts the bonding surface, ending the repositioning of the first bonding head; When the second chip contacts the bonding surface, ending the repositioning of the second bonding head; The method according to claim 1, characterized by the above.

17. Continuously receiving the updated position information of the substrate chuck and repositioning the second bonding head based on the received updated position information alternately after the first chip contacts the bonding surface and before the second chip contacts the bonding surface; The method according to claim 1, characterized by the above.

18. The updated position information includes one or more of updated X position information, updated Y position information, updated tilt information, updated rotation information, and updated tip information. The method according to claim 1, characterized by the above.

19. A system for bonding chips, a first bonding head for holding a first chip; a second bonding head for holding a second chip; a substrate chuck for supporting a bonding surface; one or more processors; one or more memories for storing instructions, and having, when the instructions are executed by the one or more processors, initializing the first bonding head to a first predetermined position relative to an initial position of the substrate chuck; initializing the second bonding head to a second predetermined position relative to the initial position of the substrate chuck; alternately receiving updated position information of the substrate chuck and repositioning the first bonding head based on the received updated position information until the first chip contacts the bonding surface; alternately receiving updated position information of the substrate chuck and repositioning the second bonding head based on the received updated position information until the second chip contacts the bonding surface; bonding the first chip and the second chip to the bonding surface; A system characterized by including instructions for causing the system to perform the above.

20. A method for manufacturing a plurality of articles, comprising: initializing a first bonding head for holding a first chip to a first predetermined position relative to an initial position of a substrate chuck for supporting a bonding surface; initializing a second bonding head for holding a second chip to a second predetermined position relative to the initial position of the substrate chuck; alternately receiving updated position information of the substrate chuck and repositioning the first bonding head based on the received updated position information until the first chip contacts the bonding surface; alternately receiving updated position information of the substrate chuck and repositioning the second bonding head based on the received updated position information until the second chip contacts the bonding surface; bonding the first chip and the second chip to the bonding surface; dicing the substrate to manufacture the plurality of articles; A method characterized by having the above steps.

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