Bonding equipment including variable force distribution

Abstract

The bonding device includes a holding element, a holding element actuator, a sensor, a controller, and a bonding force adjustment actuator. When in use, the holding element holds the electronic component, and the holding element is moved by the holding element actuator along one or more actuation directions to make the electronic component contact with the base member. In response to the contact between the electronic component and the base member, the sensor measures the reaction force applied to the holding element. The controller determines the bonding force to be applied to the actuation area of ​​the holding element during the bonding process based on the measured reaction force, and the bonding force adjustment actuator applies these bonding forces to the actuation area of ​​the holding element during the bonding process to adjust the inclination of the electronic component relative to the base member.

Description

Technical Field

[0001] The present invention generally relates to a bonding apparatus having a mechanism for adjusting force distribution or tilt of an electronic component relative to a base member (eg, substrate) when bonding an electronic component (eg, chip). Background Art

[0002] The manufacture of semiconductor devices generally involves a bonding process in which an electronic component is attached to a base member using a bonding material. For example, the electronic component may be a chip, the base member may be a substrate, and the bonding material may be an adhesive such as an epoxy resin. The bonding process is generally performed using a bonding device including a pick-up tool (e.g., a bonding head). The bonding head picks up the electronic component from a component holder (e.g., a wafer or a wafer tray) and then brings the electronic component into contact with a base member to which the bonding material has been dispensed. Thereafter, a bonding force is applied to the electronic component to push the electronic component toward the base member for bonding. The bonding force is generally applied over a certain period of time. During this period of time, the bonding material may be heat treated to change its state so that the bonding material is able to hold the electronic component and the base member together.

[0003] When the electronic component is in contact with the base member, the bonding head may occasionally tilt. This may cause the electronic component to tilt relative to the base member during the bonding process. As a result, misalignment may occur between the electronic component and the base member, which in turn affects the quality of the semiconductor device finally formed.

[0004] Conventional methods for solving the above problems include detecting the tilt in the bond head, measuring the degree of the tilt, and adjusting the bond head to correct the tilt. The tilt in the bond head can be detected in various ways. For example, a contact sensor can be used to check whether any part of the electronic component is in improper contact with the base member. Alternatively, a displacement sensor can be used to measure the displacement of various parts of the electronic component relative to the base member. A pressure detector (e.g., pressure sensitive paper) can be used to determine the distribution of the pressure applied by the electronic component on the base member, and uneven pressure distribution may indicate tilt of the bond head. After detecting the presence of tilt in the bond head, a calibration tool is typically used to measure the degree of the tilt, and the bond head is adjusted accordingly based on the measurement.

[0005] Although the above-mentioned conventional methods can reduce the tilt of the electronic component relative to the substrate member during the bonding process, these methods are very time-consuming and are performed offline. In particular, before the bonding process begins, a lot of time is required to detect, measure and correct the tilt of the bond head. This affects the time required to manufacture each semiconductor device and thus leads to a reduction in yield. In addition, due to the variation in thickness of different electronic components and substrate members, the calibration tool used in the method may not accurately measure the tilt of the electronic component relative to the substrate member. Therefore, the tilt of the bond head may often be overcorrected or undercorrected. Summary of the invention

[0006] The present invention aims to provide a novel and useful bonding apparatus.

[0007] In summary, the present invention provides a bonding device having a mechanism for adjusting the inclination of an electronic component relative to a substrate member, wherein the mechanism measures a reaction force using a sensor in response to contact between the electronic component and the substrate member, and applies a bonding force (determined based on the measured reaction force) to the electronic component during a bonding process using an actuator.

[0008] Specifically, according to a first aspect of the present invention, a bonding device is provided, comprising: a holding element configured to hold an electronic component; a plurality of holding element actuators configured to move the holding element along one or more actuation directions to bring the electronic component into contact with a base member, wherein the one or more actuation directions are arranged substantially parallel to a central axis of the holding element, the central axis extending through the electronic component and the base member; a plurality of sensors, each of which is configured to measure a reaction force applied to the holding element at a corresponding position of the holding element in response to contact between the electronic component and the base member; a controller configured to determine a bonding force to be applied to two or more actuation regions of the holding element during a bonding process based on the reaction forces measured at the corresponding positions, so as to bond the electronic component to the base member; and a plurality of bonding force adjustment actuators, which are operable to apply the determined bonding force to the corresponding actuation regions of the holding element during the bonding process.

[0009] With the above bonding device, the holding element actuator can be used to first achieve the preliminary contact between the electronic component and the base member, and then the sensor and the bonding force adjustment actuator can be used to adjust the tilt of the electronic component relative to the base member in real time. The sensor measures the reaction force indicating that the electronic component is tilted relative to the base member, and the bonding force adjustment actuator applies a bonding force (determined based on the measured reaction force) during the bonding process, wherein the bonding force helps to adjust the tilt of the electronic component relative to the base member. Therefore, unlike the prior art, the bonding device adjusts the tilt of the electronic component in real time during the bonding process. In addition, different electronic components and base members may have different characteristics, for example, different thicknesses. Since in the above bonding device, the output of the sensor is obtained in response to the contact between a specific electronic component and a specific base member to be bonded to, and each electronic component is tilted based on the output, the tilt adjustment can better match the electronic component and the base member. Therefore, the quality of the connection between each electronic component and the corresponding base member can be improved.

[0010] The holding element and the plurality of bonding force adjustment actuators are operably connected to move together along the one or more actuation directions. The relative positions of the bonding force adjustment actuator and the holding element can therefore be kept relatively consistent and close enough so that the tilt adjustment of the electronic component by the bonding force adjustment actuator can be more precise.

[0011] An actuating member may be connected between the plurality of bonding force adjustment actuators and the holding element. The bonding force adjustment actuators are capable of applying bonding forces on the holding element via the actuating member. Additional actuators may also be connected to the actuating member to move the holding element, and thus, using the actuating member may allow the holding element to have a greater freedom of movement.

[0012] The actuating member may include a first actuating member portion and a second actuating member portion having a first elongated hole and a second elongated hole oriented parallel to the central axis, respectively. The first actuating member portion may be closer to the retaining element than the second actuating member portion, and the diameter of the first elongated hole may be smaller than the diameter of the second elongated hole. The use of a hollow actuating member can help reduce the weight of the bonding device and reduce the force required to move the actuating member. The difference in diameter of the first elongated hole and the second elongated hole can increase the weight of the actuating member closer to the retaining element and allow the actuating member to move the retaining element with less force and greater stability.

[0013] The bonding device may further include a flexible element coupled to the actuating member. The flexible element may be compressed by rotating the actuating member about one or more axes perpendicular to the central axis. This helps to reduce the friction applied to hinder the actuating member from moving along the central axis and allows the actuating member to rotate.

[0014] The bonding force adjustment actuators may be arranged equidistantly around the central axis, which helps to distribute the bonding force applied to the holding element more evenly.

[0015] For example, the plurality of bonding force adjustment actuators may include a first bonding force adjustment actuator, a second bonding force adjustment actuator, a third bonding force adjustment actuator, and a fourth bonding force adjustment actuator. The first bonding force adjustment actuator may be arranged relative to the central axis to be radially opposite to the third bonding force adjustment actuator, and the second bonding force adjustment actuator may be arranged relative to the central axis to be radially opposite to the fourth bonding force adjustment actuator. This helps to achieve two-dimensional application of bonding force to better adjust the tilt of the electronic component relative to the base member.

[0016] At least one of the plurality of bond force adjustment actuators may be aligned on an axis that is the same as or parallel to an axis of at least one of the plurality of sensors. This facilitates determining a bond force to be applied by the bond force adjustment actuator based on the reaction force measured by the sensor.

[0017] During the bonding process, the plurality of bonding force adjustment actuators may be operated to apply different bonding forces at different corresponding actuation regions of the holding element. This can help to adjust the tilt of the electronic component relative to the base member.

[0018] The plurality of retaining element actuators can be operated to tilt the retaining element about one or more axes perpendicular to the central axis. This allows the electronic component to contact the base member at an angle so that the gap between the electronic component and the base member is removed by subsequent controlled movement of the retaining element.

[0019] The bonding device may further include a plurality of connectors, and each of the plurality of holding element actuators is configured to push a corresponding one of the plurality of connectors in one or more directions parallel to the central axis to move the holding element in the one or more actuation directions. This allows the holding element actuator to move the holding element along the one or more actuation directions together with the bonding force adjustment actuator and to tilt the holding element.

[0020] The bonding apparatus may further comprise a rotary actuator configured to rotate the holding element around the central axis. This allows the holding element to have greater freedom of movement.

[0021] The controller is configured to determine the bonding force to be applied by each of the plurality of bonding force adjustment actuators based on the reaction force measured by one of the plurality of sensors that is closest to the bonding force adjustment actuator. This helps to simplify the determination of the bonding force based on the measured reaction force.

[0022] The number of the bonding force adjustment actuators may be equal to the number of the sensors. This helps to simplify the determination of the bonding force based on the measured force. Alternatively, the number of the sensors may be greater than the number of the bonding force adjustment actuators. This helps to reduce the number of components in the bonding device, thereby helping to reduce the manufacturing cost of the bonding device.

[0023] According to a second aspect of the present invention, there is provided a method for bonding an electronic component to a base member, comprising: moving a holding element that holds the electronic component along one or more actuation directions to bring the electronic component into contact with the base member, wherein the one or more actuation directions are substantially parallel to a central axis of the holding element, and the central axis extends through the electronic component and the base member; measuring a reaction force applied to the holding element at a corresponding position of the holding element using a sensor in response to contact between the electronic component and the base member; determining a bonding force to be applied to two or more actuation regions of the holding element during a bonding process to bond the electronic component to the base member, wherein the bonding force is determined based on the measured reaction force; and applying the determined bonding force to the actuation regions of the holding element during the bonding process.

[0024] The above-mentioned moving the holding element may further include: tilting the holding element around an axis perpendicular to the central axis; bringing the electronic component into contact with the base member while the holding element remains tilted; rotating the holding element around an axis perpendicular to the central axis to further bring the electronic component into contact with the base member until the electronic component is substantially parallel to the base member. This helps to remove any gaps (e.g., bubbles) between the electronic component and the base member. In turn, the quality of the connection between the electronic component and the base member can be improved, and the yield rate of the device manufacturing process can be improved.

[0025] The above-mentioned rotating the holding element around an axis perpendicular to the central axis may also include: applying a first force on a first side of the holding element in a direction away from the base member; applying a second force on a second side of the holding element in a direction toward the base member, wherein the second force is greater than the first force. Such force control helps to balance the bonding load and also helps to remove the gap between the electronic component and the base member in a more gradual manner, so that any gap can be removed more thoroughly.

[0026] The reaction force may include a first reaction force applied to the first position of the holding element and a second reaction force applied to the second position of the holding element, and the method may further include: repeatedly measuring the reaction force, determining the bonding force based on the measured reaction force, and applying the determined bonding force to the actuation area of ​​the holding element until the difference between the first reaction force and the second reaction force is below a predetermined threshold. In this way, the tilt of the electronic component relative to the base member can be repeatedly adjusted and fine-tuned until the electronic component is sufficiently parallel to the base member for a specific bonding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Embodiments of the present invention will now be described, for purposes of example only, with reference to the following drawings, in which:

[0028] Figure 1A , Figure 1B and Figure 1C 1 and 2 respectively show a three-dimensional view, a top view and a partial cross-sectional front view of a bonding device according to an embodiment of the present invention, Figure 1D Shows Figures 1A to 1C A top view of the bonding device with some parts removed. Figure 1E Shows Figures 1A to 1C Flexible elements in bonding equipment.

[0029] FIG. 2A to FIG. 2C Shows the use of Figures 1A to 1C bonding equipment.

[0030] Figure 3 The use of the embodiment according to the present invention is shown Figures 1A to 1C A flow chart of a method for bonding an electronic component to a substrate member using a bonding apparatus.

[0031] Figure 4 A top view of a portion of a bonding apparatus according to an alternative embodiment of the present invention is shown.

[0032] Figure 5 A top view of a portion of a bonding apparatus according to another alternative embodiment of the present invention is shown.

[0033] Figure 6 A top view of a portion of a bonding apparatus according to another alternative embodiment of the present invention is shown.

[0034] Figure 7 A top view of a bonding apparatus according to another alternative embodiment of the present invention is shown.

[0035] Figure 8 Shows the available Figures 1A to 1C Optional flexible element in the bonding device. DETAILED DESCRIPTION

[0036] Figure 1A and Figure 1B A perspective view and a top view of a bonding device 100 according to an embodiment of the present invention are respectively shown. Figure 1C A partial cross-sectional elevation view (along the XZ plane) of the bonding apparatus 100 is shown.

[0037] The bonding apparatus 100 includes a frame 102. The frame 102 has a substantially rectangular base member 102a located in a plane parallel to the XZ plane. A curved recess 102b extends parallel to a central axis (Z axis) along a middle portion of an inner surface of the base member 102a. The frame 102 also includes a first elongated frame extension 102c and a second elongated frame extension 102d protruding from the inner surface of the base member 102a. The frame extensions 102c, 102d are substantially parallel to the curved recess 102b and extend parallel to each other along a relative width of the base member 102a.

[0038] The bonding device 100 further includes a bonding head structure 104 configured to hold an electronic component (such as but not limited to a chip). The bonding head structure 104 is movably connected to the frame 102. Figures 1A to 1C As shown, the bonding device 100 has a plurality of connectors, including a first bonding head connector 106 and a second bonding head connector 108 respectively connected to first and second sides opposite to each other of the bonding head structure 104. The first bonding head connector 106 is connected to a first guiding element 110, and the second bonding head connector 108 is connected to a second guiding element 112. The first guiding element 110 and the second guiding element 112 are respectively connected to a first frame extension 102c and a second frame extension 102d of the frame 102.

[0039] The bonding apparatus 100 further comprises a first encoder element 114 and a second encoder element 116. The guide elements 110, 112 are in the form of Z linear guides and the encoder elements 114, 116 are in the form of Z linear encoders. The first encoder element 114 is configured to cooperate with the first guide element 110 to determine a displacement relative to the frame 102 (particularly the first frame extension 102c) parallel to the Z axis of the first bond head connector 106. The second encoder element 116 is configured to cooperate with the second guide element 112 to determine a displacement relative to the frame 102 (particularly the second frame extension 102d) parallel to the Z axis of the second bond head connector 108.

[0040] The bonding device 100 also includes a plurality of holding element actuators, including a first holding element actuator 118 and a second holding element actuator 120. The holding element actuators 118, 120 are in the form of motors. Each holding element actuator 118, 120 is held in a respective actuator holder 122, 124, which in turn is connected to a corresponding frame extension 102c, 102d of the frame 102. The holding element actuators 118, 120 are configured to move the bond head structure 104 along one or more actuation directions parallel to the Z axis so that the electronic component held by the bond head structure 104 is in contact with the substrate member. More specifically, the first holding element actuator 118 and the second holding element actuator 120 are connected to the first bond head connector 106 and the second bond head connector 108, respectively. Each holding element actuator 118, 120 is configured to push the corresponding bond head connector 106, 108 relative to the frame 102 in one or more directions parallel to the Z-axis to move the bond head structure 104 along the actuation direction. In addition, the holding element actuators 118, 120 are also operable to tilt the bond head structure 104 about the X-axis and the Y-axis perpendicular to the Z-axis.

[0041] like Figures 1A to 1C As shown, the bonding apparatus 100 further includes an imaging unit 126 connected to the bond head structure 104 via a connecting element 128. The imaging unit 126 is configured to capture an image of an electronic component held by the bond head structure 104.

[0042] The bond head structure 104 will now be described in more detail.

[0043] Reference Figures 1A to 1C The bonding head structure 104 includes an actuator housing 130 in the form of a fixed bracket. The actuator housing 130 has a cylindrical structure with a central hole and is as shown in FIG. Figure 1C As shown, a groove 130 a is provided around the inner surface of the actuator housing 130 .

[0044] like Figure 1CAs shown, the actuating member 132 in the form of a shaft is arranged through the central hole of the actuator housing 130. In particular, the actuating member 132 includes a first actuating member portion 132a and a second actuating member portion 132b arranged above the first actuating member portion 132a. Figure 1B and Figure 1C , each of the first actuating member portion 132a and the second actuating member portion 132b has a hollow cylindrical structure. In particular, the first actuating member portion 132a has a first elongated hole, and the second actuating member portion 132b has a second elongated hole. Each elongated hole generally extends through the middle of the corresponding cylindrical structure and is oriented parallel to the Z axis. The first elongated hole of the first actuating member portion 132a has an X-shaped cross-section, while the second elongated hole of the second actuating member portion 132b has a circular cross-section. The centers of the first elongated hole and the second elongated hole are roughly aligned, and the diameter of the X-shaped cross-section of the first elongated hole (in other words, the dimension between the farthest ends of the cross-section) is smaller than the diameter of the circular cross-section of the second elongated hole. The actuating member 132 also includes a groove 132c surrounding the outer surface of the first actuating member portion 132a. As Figure 1C As shown, the groove 132c of the actuating member 132 is arranged to face the groove 130a of the actuator housing 130, and the tops of the grooves 130a and 132c are aligned. In addition, the actuating member 132 also includes an extension 132d, which protrudes from the outer surface of the second actuating member part 132b around the top of the actuating member part 132b.

[0045] like Figure 1B and Figure 1C As shown, the bonding device 100 further comprises a support element 134 having an X-shaped cross-section extending through a first elongated hole of the first actuating member portion 132a. Specifically, the support element 134 comprises four arms 134a-134d, wherein each pair of adjacent arms 134a-134d defines a tapered elongated groove.

[0046] The bonding head structure 104 further comprises a holding element 136 in the form of a pick-up tool / bonding head, which is configured to hold an electronic component such as a chip. The holding element 136 is coupled to the actuating member 132, and the sensor unit 138 is disposed between the holding element 136 and the actuating member 132. In particular, the actuating member 132 is arranged relative to the holding element 136, so that the first actuating member portion 132a is closer to the holding element 136 than the second actuating member portion 132b.

[0047] The bond head structure 104 further includes a rotary actuator 140 having a fixed element 140a in the form of a fixed θ magnet and a movable element 140b in the form of a movable θ coil. The fixed element 140a and the movable element 140b of the rotary actuator 140 have a hollow cylindrical structure with a central hole. The movable element 140b is disposed in the central hole of the fixed element 140a, and the fixed element 140a is disposed on the actuator housing 130. Figure 1C As shown, the actuating member 132 extends beyond the central hole of the actuator housing 130 and enters the central hole of the movable element 140a of the rotary actuator 140. The rotary actuator 140 is configured to rotate the actuating member 132 (and thus the retaining element 136) around the central axis (Z axis). In particular, the movable element 140b of the rotary actuator 140 is connected to the actuating member 132, more specifically, to the second actuating member portion 132b and the extension portion 132d. The rotary actuator 140 can be driven to rotate the movable element 140b (together with the actuating member 132 connected thereto) relative to the fixed element 140a around the Z axis.

[0048] like Figures 1A to 1C As shown, the cover 142 is disposed above the actuating member 132. Figure 1C As shown, the cover 142 is arranged to be located on the extension 132d of the actuating member 132. The cover 142 includes a lower inner surface 142a and an upper inner surface 142b. The upper inner surface 142b defines a cylindrical hole, and the lower inner surface 142a tapers toward the upper inner surface 142b and forms a truncated conical hole. The top of the truncated conical hole is aligned with the cylindrical hole defined by the upper inner surface 142b. Figure 1A and Figure 1B As shown, the cover 142 includes a plurality of circular grooves 142c and corresponding first engaging elements 142d disposed therein. Figure 1C As shown, a plurality of second engagement elements 142e extend through the cover 142. Circular grooves 142c and second engagement elements 142e are alternately arranged around the top surface of the cover 142.

[0049] Figure 1D A top view of a portion of the bonding apparatus 100 is shown, particularly with portions of the actuation member 132 , the rotary actuator 140 , and the cover 142 omitted.

[0050] refer to Figure 1C and Figure 1D , the bonding apparatus 100 includes a flexible element 144 having an annular structure disposed around the actuating member 132 . Figure 1E An enlarged front view of the flexible element 144 and a portion of the actuation member 132 is shown. Figure 1EAs shown, the flexible element 144 is in the form of a flexible air bearing, which has a housing 144a, a flexible compartment 144b, and an air film 144c in the flexible compartment 144b. The air film 144c includes compressed air and serves as a flexible layer. Figure 1C As shown, the flexible element 144 is arranged between the actuator housing 130 and the actuating member 132. In particular, the flexible element 144 is arranged between the groove 132c of the actuating member 132 and a portion of the actuator housing 130 located below the groove 130a. The actuating member 132 can move along the Z axis relative to the flexible element 144 (e.g., Figure 1E 143 in the figure), the flexible element 144 is used to reduce the friction that hinders the movement. In addition, the flexible element 144 can be compressed by rotating the actuating member 132 around one or more axes perpendicular to the Z axis. For example, when a torque is applied to the actuating member 132, the actuating member 132 can be rotated around the Y axis by compressing the flexible element 144 (as shown by arrow 145). However, since the flexible compartment 144b also has a certain rigidity, only a limited part of it can be compressed. Accordingly, the extent to which the actuating member 132 rotates around the axis perpendicular to the Z axis is limited.

[0051] refer to Figure 1C and Figure 1D , the bond head structure 104 further comprises a plurality of bond force adjustment actuators, namely a first bond force adjustment actuator 146, a second bond force adjustment actuator 148, a third bond force adjustment actuator 150 and a fourth bond force adjustment actuator 152 in the form of motors. The actuating member 132 is connected between the plurality of bond force adjustment actuators 146-152 and the holding element 136. In particular, each bond force adjustment actuator 146-152 is respectively connected to a corresponding side of the actuating member 132, which in turn is connected to the holding element 136 via the sensor unit 138. The holding element 136 and the plurality of bond force adjustment actuators 146-152 are thus operably connected to be moved together in one or more actuation directions via the holding element actuators 118, 120.

[0052] like Figure 1D As shown, the bond force adjustment actuators 146-152 are equidistantly arranged around the Z axis, or more specifically, around the actuation member 132. The bond force adjustment actuators 146-152 are symmetrically arranged around the X axis and the Y axis, with the first bond force adjustment actuator 146 aligned with the third bond force adjustment actuator 150 on the X axis, and the second bond force adjustment actuator 148 aligned with the fourth bond force adjustment actuator 152 on the Y axis. The first bond force adjustment actuator 146 is arranged to be diametrically opposite to the third bond force adjustment actuator 150 with respect to the Z axis, and the second bond force adjustment actuator 148 is arranged to be diametrically opposite to the fourth bond force adjustment actuator 152 with respect to the Z axis.

[0053] Each bonding force adjustment actuator 146-152 includes a fixed element 146a, 148a, 150a, 152a in the form of a magnet and a movable element 146b, 148b, 150b, 152b in the form of a coil unit having a plurality of coil segments spaced apart from each other. Figure 1C As shown, the fixed element 146a-152a of each bonding force adjustment actuator 146-152 is arranged in the groove 130a of the actuator housing 130, and each movable element 146b-152b is arranged above the flexible element 144 with a gap therebetween. In addition, the movable element 140b of the rotary actuator 140 is arranged above the movable elements 146b-152b of the bonding force adjustment actuators 146-152 with another gap therebetween.

[0054] The bonding force adjustment actuators 146-152 are associated with two or more actuation regions of the holding element 136 and are configured to apply bonding force to these associated actuation regions of the holding element 136 during bonding. In particular, each bonding force adjustment actuator 146-152 is actuated to push the movable element 146b-152b of the actuator 146-152 relative to the fixed element 146a-152a. The movable element 146b-152b of each bonding force adjustment actuator 146-152 is connected to the corresponding side of the actuation member 132 and is configured to move parallel to the Z axis with the side of the actuation member 132. Therefore, the actuation of the bonding force adjustment actuator 146-152 causes the corresponding side of the actuation member 132 to move, and then pushes the holding element 136 at the associated actuation region of the holding element 136. Because the bond force adjustment actuators 146 - 152 are independently controllable, they are operable to apply different bonding forces at different associated actuation regions of the retaining element 136 during the bonding process.

[0055] The bonding device 100 also includes a sensor array having a plurality of sensors, including a first sensor 154, a second sensor 156, a third sensor 158, and a fourth sensor 160 in the form of force sensors, which are configured to measure the reaction force applied to the holding element 136 in response to the contact between the electronic component held by the holding element 136 and the substrate member. The sensors 154-160 are arranged within a sensor unit 138 located between the holding element 136 and the actuating member 132. The sensors 154-160 are arranged to detect reaction forces and moments in different directions in response to the contact between the electronic component and the substrate member. Each sensor 154-160 is associated with a corresponding position of the holding element 136. As shown in FIG. Figure 1DAs more clearly shown in , the sensors 154-160 are arranged equidistantly around the Z axis. In particular, the sensors 154-160 are arranged symmetrically around the Z axis, wherein the first sensor 154 and the third sensor 158 are aligned on the same axis (X axis) as the first bonding force adjustment actuator 146 and the third bonding force adjustment actuator 150, and the second sensor 156 and the fourth sensor 160 are aligned on the same axis (Y axis) as the second bonding force adjustment actuator 148 and the fourth bonding force adjustment actuator 152. Figure 1C and Figure 1D , each sensor 154 - 160 is arranged to be located below a corresponding tapered elongated recess defined by adjacent arms 134 a - 134 d of the support element 134 .

[0056] Although not shown in the figures, the bonding apparatus 100 further includes a controller configured to determine a bonding force to be applied to the two or more actuation regions of the holding element 136 during the bonding process to bond the electronic component held by the holding element 136 to the substrate member. The controller is operable to determine the bonding force based on the reaction force measured by the sensors 154-160.

[0057] FIG. 2A to FIG. 2C The bonding apparatus 100 is shown in use. Figure 3 A flow chart of a method for bonding an electronic component to a substrate member using the bonding apparatus 100 is shown. Figure 2C The method 300 is described in more detail.

[0058] In step 302, the holding element 136 of the bonding apparatus 100 picks up the electronic component 202 and brings the electronic component 202 to a position above the base member 204. At this position, the Z axis extends through the electronic component 202 and the base member 204 (eg, a substrate to which the electronic component 202 will be bonded).

[0059] In step 304 , the holding element actuators 118 , 120 move the holding element 136 (which holds the electronic component 202 ) to bring the electronic component 202 into contact with the substrate member 204 .

[0060] like Figure 2AAs shown, the bonding apparatus 100 tilts the bond head structure 104 (and thus the holding element 136) about the Y-axis to bring the electronic component 202 into contact with the substrate member 204. Specifically, the first holding element actuator 118 is driven to exert a downward force (i.e., a force toward the substrate member 204) on the first bond head connector 106 connected to the first side of the bond head structure 104, and the second holding element actuator 120 is driven to exert an upward force (i.e., a force away from the substrate member 204) on the second bond head connector 108 connected to the second side of the bond head structure 104. Thus, the first bond head connector 106 (together with the first side of the bond head structure 104) moves along a first actuation direction 206; conversely, the second bond head connector 108 (together with the second side of the bond head structure 104) moves along a second actuation direction 208. The actuation directions 206, 208 are generally parallel to the Z-axis and opposite to each other. This causes the retaining element 136 to tilt about the Y axis. Figure 2A As shown, while the holding element 136 remains tilted, the electronic component 202 comes into contact with the base member 204. This initial contact between the electronic component 202 and the base member 204 occurs at the contact area 204a.

[0061] The tilt of the bond head structure 104 about the Y-axis is controlled by a feedback loop. In particular, when the first side and the second side of the bond head structure 104 are moved respectively in the first actuation direction 206 and the second actuation direction 208, the displacement of the first bond head connector 106 and the second bond head connector 108 relative to the frame 102 is determined by the guide elements 110, 112 and the encoder elements 114, 116 and fed back to the controller. The controller determines the amount of further displacement to be performed on the first bond head connector 106 and the second bond head connector 108 to achieve the desired tilt of the bond head structure 104. Then, the holding element actuators 118, 120 are driven to achieve the further displacement.

[0062] Figure 2B and Figure 2C 2 shows that when the electronic component 202 initially contacts the base member 204 at the contact area 204a Figure 2A An enlarged view of the retaining element 136. Figure 2B and Figure 2CAs shown, when the electronic component 202 initially contacts the base member 204, a plurality of gaps 212 (e.g., bubbles) may exist between the electronic component 202 and the base member 204. After the initial contact, the holding element 136 is rotated about the Y axis to further contact the electronic component 202 with the base member 204 until the electronic component 202 is substantially parallel to the base member 204. In particular, by moving the first bond head connector 106, the first holding element actuator 118 is driven to apply a first force (upward force) on a first side of the holding element 136 in a direction away from the base member 204, and by moving the second bond head connector 108, the second holding element actuator 120 is driven to apply a second force (downward force) on a second side of the holding element 136 in a direction toward the base member 204. The downward force on the holding element 136 is greater than the upward force on the holding element 136. Thus, while the second side of the retaining element 136 is pushed downward (as indicated by arrow 216, toward the base member 204), the first side of the retaining element 136 is lifted upward (as indicated by arrow 214). This gradually compresses the gap 212 between the electronic component 202 and the base member 204 and pushes air out of the gap in a direction away from the contact area 204a (as indicated by arrow 218).

[0063] In step 306, sensors 154-160 measure reaction forces applied to electronic component 202 (and therefore, to holding element 136) in response to contact between electronic component 302 and base member 204 in step 304. These reaction forces are measured at corresponding locations of holding element 136 associated with each sensor 154-160. The reaction forces, or the distribution of forces applied by base member 204 to electronic component 202, indicate the tilt of holding element 136 about one or more axes perpendicular to the Z axis. For example, a greater reaction force detected by first sensor 154 than by third sensor 156 indicates tilt of holding element 136 about the Y axis, where holding element 136 is closer to base member 204 along the axis where first sensor 154 is located than along the axis where third sensor 156 is located.

[0064] In step 308, the controller of the bonding apparatus 100 determines a bonding force to be applied to two or more actuation regions of the holding element 136 during the bonding process to bond the electronic component 202 to the substrate member 204. The bonding force is determined based on the reaction force measured by the sensors 154-160. In particular, the bonding force is determined so that applying the bonding force on the holding element 136 causes the holding element 136 to rotate about one or more axes perpendicular to the Z axis, so that the holding element 136 is substantially parallel to each of these axes. Further or alternatively, the controller is configured to determine that a larger bonding force is applied to the holding element 136 at an actuation region associated with a smaller reaction force.

[0065] In step 310, a bonding process is performed, and during bonding, the plurality of bond force adjustment actuators 146-152 apply the desired bonding forces to the associated actuation areas of the holding element 136. In particular, the controller sends control signals to the bond force adjustment actuators 146-152 to apply these bonding forces.

[0066] The method 300 includes repeatedly measuring the reaction force, determining the bonding force based on the measured reaction force, and applying the determined bonding force to the associated actuation area of ​​the holding element 136 in steps 306 to 310 until the distribution of the reaction force on the electronic component 304 is sufficiently balanced as measured by the sensors 146-152. In particular, in step 310, after the bonding force is applied to the holding element 136, the reaction force on the holding element 136 is again detected by the sensors 154-160 in step 306, and in step 308, the controller determines a corrected bonding force to be applied to the holding element 136 based on the most recently detected reaction force. In step 310, the updated bonding force is applied to the holding element 136, and steps 306 to 310 are repeated again. Until the reaction forces detected by sensors 154 - 160 in step 306 are substantially the same, or more specifically, until the difference between a first reaction force applied at the first position of retaining element 136 and a second reaction force applied at the second position of retaining element 136 is less than a predetermined threshold.

[0067] Therefore, the bonding apparatus 100 can make the force distribution applied to the electronic component 202 during the bonding process more balanced. More specifically, the controller together with the sensors 154-160 and the bonding force adjustment actuators 146-152 form a closed-loop servo control system that can achieve a balanced force distribution on the electronic component 202 during the bonding process.

[0068] Various modifications may be made to the above-described embodiments.

[0069] For example, a different number of bond force adjustment actuators and / or sensors than described above may be provided, and the bond force adjustment actuators and / or sensors may be arranged in a different manner. In some embodiments, the number of bond force adjustment actuators may be equal to the number of sensors, however, in other embodiments, the number of bond force adjustment actuators may be less than the number of sensors. In some embodiments, at least one of the bond force adjustment actuators is aligned on the same axis as at least one of the sensors.

[0070] Figures 4 to 7 1 and 2. Top views of bonding apparatuses 400, 500, 600, 700 according to alternative embodiments of the present invention are shown, respectively. Because bonding apparatuses 400, 500, 600, 700 are similar to bonding apparatus 100, common features are labeled with the same reference numerals and need not be discussed again. Figures 4 to 7 The top view of FIG. 1 shows each bonding apparatus 400 , 500 , 600 , 700 with the actuation member 132 , the rotary actuator 140 , and the cover 142 omitted.

[0071] refer to Figure 4 Compared with the bonding device 100, the bonding device 400 includes only three bonding force adjustment actuators 402, 404, 406. The bonding force adjustment actuators 402-406 are arranged equidistantly around the Z axis. When the first bonding force adjustment actuator 402 is aligned with the first sensor 154 and the third sensor 158 on the X axis, the second bonding force adjustment actuator 404 and the third bonding force adjustment actuator 406 are located outside the Y axis, and the second sensor 156 and the fourth sensor 160 are located on the Y axis.

[0072] refer to Figure 5 Compared with the bonding device 100, the bonding device 500 includes only three bonding force adjustment actuators 502, 504, 506. In addition, unlike the bonding devices 100, 400, the bonding device 500 includes only three sensors 508, 510, 512. Figure 5 As shown, the bonding force adjustment actuators 502, 504, 506 are arranged equidistantly around the Z axis. Likewise, the sensors 508, 510, 512 are arranged equidistantly around the Z axis. Each bonding force adjustment actuator 502, 504, 506 is aligned with a corresponding one of the sensors 508, 510, 512 on the same axis.

[0073] like Figure 6 As shown, unlike the bonding devices 100, 400, 500, the bonding device 600 only includes two bonding force adjustment actuators 602, 604 and two sensors 606, 608. Figure 6As shown, the bonding force adjustment actuators 602 and 604 are arranged equidistantly around the Z axis and symmetrically around the X axis. Similarly, the sensors 606 and 608 are arranged equidistantly around the Z axis and symmetrically around the X axis. The bonding force adjustment actuators 602 and 604 are aligned on the same axis (Y axis) as the sensors 606 and 608, respectively.

[0074] refer to Figure 7 , the bonding device 700 includes only two bonding force adjustment actuators 702, 704 and two sensors 706, 708, similar to the bonding device 600. The bonding force adjustment actuators 702, 704 and sensors 706, 708 of the bonding device 700 are arranged in the same manner as the bonding force adjustment actuators and sensors in the bonding device 600, except that they are aligned on the X-axis instead of the Y-axis.

[0075] A further variation that may be made to the above described embodiment is to omit the rotary actuator 140 and / or the actuation member 132. For example, the bond force adjustment actuators 146-152 may be coupled directly to the retaining element 136 to exert a bond force on an associated actuation region of the retaining element 136.

[0076] Furthermore, the actuation member 132 may have a Figure 1C In some embodiments, the actuating member 132 may have a structure different from the structure shown. In particular, the actuating member 132 need not have a first actuating member portion 132a and a second actuating member portion 132b with elongated holes of different types of cross-sections. Instead, the actuating member 132 may have elongated holes with the same type of cross-section, such as a circular cross-section, and the diameter of the first elongated hole of the first actuating member portion 132a is smaller than the diameter of the second elongated hole of the second actuating member portion 132b. In some variations, the actuating member 132 may have a single elongated hole with a constant diameter. In some variations, the actuating member 132 may not even have a hollow structure.

[0077] Additionally, the flexible element 144 need not be in the form of a flexible air bearing. Figure 8 A flexible element 144 in the form of a flexible ball bearing is shown. The ball bearing 144 includes a housing 144a, a flexible compartment 144b, and a plurality of balls 144c disposed within the flexible compartment 144b. Since each ball 144c is made of an elastic material, it is deformable. Accordingly, similar to an air bearing, the flexible compartment 144b of the ball bearing 144 can be compressed by rotating the actuating member 132 about one or more axes perpendicular to the Z axis. Therefore, the actuating element 132 can not only move relative to the flexible element 144 along the Z axis (as shown by arrow 143), but can also rotate about the Y axis (as shown by arrow 145) by compressing the flexible element 144. However, the degree of rotation is limited by the stiffness of the flexible compartment 144b.

[0078] Moreover, the controller may be configured to determine the bonding force in various ways. For example, the controller may be configured to determine the bonding force to be applied by each of the plurality of bonding force adjustment actuators 146-152 based on the reaction force measured by the one of the plurality of sensors 154-160 closest to the bonding force adjustment actuator 146-152.

[0079] In addition, if Figure 2A As shown, when the electronic component 202 contacts the base member 204, the bonding head structure 104 can be tilted at various angles around the Y axis. Figure 2A As shown, the angle 210 between the electronic component 202 and the base member 204 may range from 5 degrees to 10 degrees. Figure 2A , the bond head structure 104 is shown as tilted counterclockwise about the Y axis. However, in some embodiments, the bond head structure 104 can be tilted clockwise about the Y axis. In other words, the first holding element actuator 118 can push the bond head structure 104 along the second actuation direction 208 (upward), and the second holding element actuator 120 can push the bond head structure 104 along the first actuation direction 206 (downward).

[0080] In some embodiments, the bond head structure 104 is not tilted about the Y-axis to bring the electronic component 202 into contact with the base member 204. Instead, the holding element actuators 118, 120 can be configured to exert substantially equal forces on the respective bond head connectors 106, 108 in the same direction (first actuation direction 206) so that the holding element 136 remains substantially parallel to the base member 204 throughout the movement of the holding element 136 toward the base member 204. In other words, the holding element 136 can only be moved along a single actuation direction that is parallel to the Z-axis.

[0081] Further, in the above embodiments, various tools may be used with the bonding device. For example, a calibration tool or chuck may be used to measure the tilt of the electronic component 202, and the bonding force applied by the bonding force adjustment actuator 146-152 may be based on the output of the calibration tool or chuck and the output of the sensors 154-160.

[0082] Although the present invention has been described in detail above, various changes, modifications and / or additions can be easily made to the present invention. It should be understood that the changes, modifications and / or additions made to the present invention fall within the spirit and scope of the above description.

Claims

1. A bonding device, comprising: a holding component configured to hold an electronic component; a plurality of holding element actuators configured to move the holding element in one or more actuation directions so that the holding element tilts about an axis perpendicular to a central axis of the holding element to bring the electronic element into contact with the base member, and to rotate the holding element about the axis to bring the electronic element into further contact with the base member until the electronic element is parallel to the base member; wherein the one or more actuation directions are arranged parallel to the central axis of the holding element, and the central axis of the holding element extends through the electronic element and the base member; a plurality of sensors, each of the sensors being configured to measure a reaction force applied to the holding element at a corresponding position of the holding element in response to contact between the electronic component and the base member; a controller being configured to determine a bonding force to be applied to two or more actuation regions of the holding element during a bonding process to bond the electronic component to the base member based on the reaction forces measured at the corresponding positions; and A plurality of bonding force adjustment actuators are operable to apply a determined bonding force to corresponding said actuation areas of said retaining element during said bonding process.

2. The bonding device according to claim 1, wherein: The retaining element and the plurality of bond force adjustment actuators are operably connected to move together along the one or more actuation directions. 3 . The bonding apparatus according to claim 1 , further comprising an actuating member connected between the plurality of bonding force adjustment actuators and the holding element.

4. The bonding device according to claim 3, wherein: The actuating member includes a first actuating member portion having a first elongated hole and a second actuating member portion having a second elongated hole, wherein the first elongated hole and the second elongated hole are oriented parallel to the central axis, and wherein the first actuating member portion is closer to the retaining element than the second actuating member portion, and a diameter of the first elongated hole is smaller than a diameter of the second elongated hole.

5. The bonding apparatus of claim 3, further comprising a flexible element coupled to the actuation member, wherein The flexible element can be compressed by rotating the actuation member about one or more axes perpendicular to the central axis.

6. The bonding device according to claim 1, wherein: The bonding force adjustment actuators are arranged equidistantly around the central axis.

7. The bonding apparatus according to claim 1, wherein: The multiple bond force adjustment actuators include a first bond force adjustment actuator, a second bond force adjustment actuator, a third bond force adjustment actuator and a fourth bond force adjustment actuator, wherein the first bond force adjustment actuator is arranged relative to the center axis to be radially opposite to the third bond force adjustment actuator, and the second bond force adjustment actuator is arranged relative to the center axis to be radially opposite to the fourth bond force adjustment actuator.

8. The bonding apparatus according to claim 1, wherein: At least one of the plurality of bond force adjustment actuators is aligned on an axis that is the same as or parallel to an axis of at least one of the plurality of sensors.

9. The bonding apparatus according to claim 1, wherein: During the bonding process, the plurality of bond force adjustment actuators are operable to apply different bonding forces at different corresponding actuation regions of the retaining element.

10. The bonding apparatus according to claim 1, wherein: The plurality of retaining element actuators include a first retaining element actuator operable to apply a first force on a first side of the retaining element in a direction away from the base member and a second retaining element actuator operable to apply a second force on a second side of the retaining element in a direction toward the base member, wherein the second force is greater than the first force.

11. The bonding device according to claim 1 further includes a plurality of connectors, and each of the plurality of retaining element actuators is configured to push a corresponding one of the plurality of connectors along one or more directions parallel to the central axis to move the retaining element along the one or more actuation directions.

12. The bonding apparatus of claim 1, further comprising a rotary actuator configured to rotate the holding element about the central axis.

13. The bonding apparatus according to claim 1, wherein: The controller is configured to determine a bond force to be applied by each of the plurality of bond force adjustment actuators based on a reaction force measured by a sensor of the plurality of sensors that is closest to the bond force adjustment actuator.

14. The bonding apparatus according to claim 1, wherein: The number of the bonding force adjustment actuators is equal to the number of the sensors.

15. The bonding apparatus according to claim 1, wherein: The number of the sensors is greater than the number of the bonding force adjustment actuators.

16. A method for bonding an electronic component to a substrate member, comprising: Using a plurality of holding element actuators to move a holding element holding the electronic element along one or more actuation directions so that the holding element is tilted around an axis perpendicular to a central axis of the holding element so that the electronic element contacts the base member, and the holding element is rotated around the axis so that the electronic element contacts the base member further until the electronic element is parallel to the base member; wherein the one or more actuation directions are parallel to the central axis of the holding element, and the central axis of the holding element extends through the electronic element and the base member; In response to contact between the electronic component and the base member, measuring a reaction force applied to the holding element at a corresponding position of the holding element using a sensor; determining a bonding force to be applied to the two or more actuation regions of the holding element during a bonding process to bond the electronic component to the substrate member, wherein the bonding force is determined based on the measured reaction force; During the bonding process, a determined bonding force is applied to the actuation area of ​​the holding element using a plurality of bonding force adjustment actuators.

17. The method according to claim 16, wherein: Rotating the holding element about an axis perpendicular to the central axis further comprises: applying a first force on a first side of the retaining element in a direction away from the base member; and A second force is applied on a second side of the retaining element in a direction toward the base member, wherein the second force is greater than the first force.

18. The method according to claim 16, wherein: The reaction force includes a first reaction force applied at a first position of the holding element and a second reaction force applied at a second position of the holding element, and wherein the method further comprises: repeatedly measuring the reaction force; determining the bonding force based on the measured reaction force; and applying the determined bonding force to the actuating area of ​​the holding element until the difference between the first reaction force and the second reaction force is lower than a predetermined threshold.

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