A thermocompression bonding head for three-dimensional chip stacking

Abstract

This invention relates to the field of thermocompression bonding technology for semiconductor devices, specifically a thermocompression bonding head for three-dimensional chip stacking. To address the technical problem that existing thermocompression bonding heads cannot guarantee high-precision thermocompression bonding quality, a new thermocompression bonding head for three-dimensional chip stacking is provided, comprising a rotation drive module, a force control module, an air flotation module, a leveling module, and a heating stage module. The thermocompression bonding head of this invention adopts a modular integrated design of the rotation drive module, force control module, air flotation module, leveling module, and heating stage module. Each module has a clear function and independent structure, facilitating assembly, debugging, and maintenance. Reliable connections are achieved between modules through couplings, fixed connections, etc., resulting in a compact overall structure that can adapt to the miniaturization and high-precision packaging requirements of three-dimensional chip stacking. Furthermore, it facilitates subsequent upgrades or replacements of individual modules according to process requirements, improving the equipment's versatility and scalability.

Description

Technical Field

[0001] This invention relates to the field of thermo-press bonding technology for semiconductor devices, specifically a thermo-press bonding head for three-dimensional chip stacking. Background Technology

[0002] With the evolution of Moore's Law and the continuous improvement of semiconductor device integration, advanced semiconductor device packaging technology has become a key path to continue Moore's Law and improve system performance. 3D chip stacking is a technology that overcomes the limitations of traditional 2D integrated circuits by vertically stacking multiple layers of chips and interconnecting them. It is currently the mainstream technology for semiconductor devices, and thermocompression bonding technology is the core process for realizing 3D chip stacking.

[0003] Thermocompression bonding technology applies pressure and high temperature simultaneously, causing metal bumps (such as copper pillars or solder) on the chip to diffuse or melt with pads on the substrate, thus forming a reliable electrical and mechanical connection. Compared to traditional reflow soldering, thermocompression bonding effectively avoids thermal damage to surrounding packaged devices and significantly reduces the height of the package layer, meeting the stringent requirements of high I / O density and miniaturization in fields such as high-performance computing and artificial intelligence.

[0004] As the core execution component of thermocompression bonding technology, the thermocompression bonding head integrates functions such as multi-dimensional motion, precision force control, and rapid heating. Its performance directly determines the alignment accuracy, connection yield, and production efficiency of thermocompression bonding. However, existing thermocompression bonding heads still have many shortcomings: First, due to limitations in chip manufacturing processes, differences in the coefficient of thermal expansion of materials, and machining accuracy errors of the fixture, the chip and substrate often exhibit microscopic warping or relative tilting under high-temperature environments, making it impossible for the chip and substrate to bond evenly. Second, the force control module, due to its large load, experiences severe heat generation and insufficient response capability, making it difficult to perfectly adapt to the surface morphology of the warped chip, easily leading to uneven local pressure and resulting in poor soldering or chip crushing. In addition, the thermocompression bonding process has high precision requirements for Z-axis displacement and rotation angle, and existing thermocompression bonding heads cannot guarantee the high-precision thermocompression bonding quality requirements. Summary of the Invention

[0005] In order to solve the technical problem that existing thermocompression bonding heads cannot guarantee the high-precision thermocompression bonding quality requirements, this invention provides a new thermocompression bonding head for three-dimensional chip stacking.

[0006] This invention is achieved using the following technical solution:

[0007] A thermocompression bonding head for three-dimensional chip stacking includes:

[0008] A rotary drive module, including a rotary motor whose axis is vertically arranged;

[0009] The force control module includes a linear voice coil motor with its axis arranged vertically, and the stator of the linear voice coil motor is connected to the shaft of a rotary motor via a coupling.

[0010] The air bearing module includes an air bearing and an air bearing guide mechanism. The top of the mover of the air bearing is fixed to the bottom of the mover of the linear voice coil motor. The air bearing guide mechanism is used to ensure that the stator of the air bearing can only move axially.

[0011] The leveling module includes a base, a leveling component, a magnet for adsorbing the leveling component, and a limiting mechanism. The bottom of the air bearing's mover is fixed to the top surface of the base. The bottom surface of the base has a ball groove, and a porous, permeable spherical seat with a spherical bottom is installed in the ball groove. The center of the porous, permeable spherical seat has a central hole, through which the magnet is installed in the ball groove. The top of the leveling component is spherical and fits into the porous, permeable spherical seat to form a spherical mating pair. The base has a positive pressure air inlet and a negative pressure air inlet. Compressed air introduced through the positive pressure air inlet is evenly output through the porous, permeable spherical seat and forms a uniform air film between the porous, permeable spherical seat and the leveling component. Negative pressure gas is introduced through the negative pressure air inlet and evenly extracted through the porous, permeable spherical seat, so that the leveling component is negatively locked to the porous, permeable spherical seat. The limiting mechanism is used to restrict the circumferential rotation of the leveling component.

[0012] The heating platform module is fixed to the bottom end of the leveling component and is used to adsorb the chip and heat the chip.

[0013] Principle Description: During use, both the rotary motor and the air bearing guide mechanism are fixed to the gantry of the thermosetting bonding equipment. The rotary drive module mainly uses a rotary motor to rotate the thermosetting bonding head; the force control module mainly uses a linear voice coil motor to press down the thermosetting bonding head; the rotary motor and the linear voice coil motor are connected by a coupling, so that when the rotary motor rotates, it drives the linear voice coil motor to rotate; the air bearing module is installed at the bottom of the linear voice coil motor, mainly to counteract the load installed below the linear voice coil motor, facilitating high-precision pressing control of the linear voice coil motor. When the linear voice coil motor rotates with the rotary motor, the mover of the air bearing also rotates. By introducing compressed air into the air bearing, rotation with near-zero friction is achieved. Simultaneously, when the mover of the linear voice coil motor presses down, it drives the air bearing to press down; the leveling module, during use, uses a heating stage assembly to adsorb the chip, and then compressed air is introduced into the positive pressure air inlet to compress... Air is evenly output through the porous spherical spherical seat, forming a uniform air film between the seat and the leveling component. At this point, the leveling component is only subject to a weak pre-tightening adsorption force provided by the magnet. The air film eliminates the mechanical frictional resistance between the spherical mating pairs, allowing the leveling component to automatically adjust its angle according to the bonding surface between the chip and the substrate, achieving unconstrained adaptive leveling. Simultaneously, the limiting mechanism restricts the circumferential rotation of the leveling component around the vertical axis, preventing deflection during adjustment. After leveling, the positive pressure air inlet is closed, and the negative pressure air inlet is opened. Gas is evenly drawn through the porous spherical spherical seat, evacuating the air film between the seat and the leveling component, forming a uniform vacuum adsorption force. With the assistance of the magnet, the leveling component is rigidly locked onto the porous spherical spherical seat, and the posture of the spherical mating pairs is completely fixed, ensuring stable leveling accuracy and no deviation in subsequent processes.

[0014] Furthermore, the air flotation module also includes a self-weight offsetting mechanism fixed to the air flotation guide mechanism, which supports the force control module. This self-weight offsetting mechanism further offsets the load on the force control module, preventing the linear voice coil motor from continuously supplying a large current to offset the load and avoiding severe overheating of the linear voice coil motor. Simultaneously, a large load can also cause the linear voice coil motor to respond slowly, affecting the downward positioning of the linear voice coil motor's mover.

[0015] Furthermore, the air-bearing guide mechanism includes two air-bearing guide mounting plates and two dovetail-shaped sliders respectively fixed to the left and right side walls of the air bearing stator. One side of each of the two air-bearing guide mounting plates is equipped with a dovetail-shaped guide rail adapted to the dovetail-shaped slider. In use, both air-bearing guide mounting plates are fixed to the gantry of the hot-press bonding equipment. The structure of the air-bearing guide mechanism is specific, simple, and easy to implement.

[0016] Furthermore, the self-weight offsetting mechanism includes a bushing fixed to the other side of one of the air-bearing guide mounting plates. A support plate is supported above the bushing via a cylinder. The support plate has an air-bearing guide shaft that is axially slidably connected to the bushing. The top surface of the support plate abuts against the bottom surface of the force control module. In use, the cylinder supports the support plate upwards, further offsetting the load on the linear voice coil motor and preventing the linear voice coil motor from continuously supplying a large current to offset the load.

[0017] Furthermore, the air flotation module also includes an angle detection component for detecting the rotation angle of the air bearing mover and a displacement detection component for detecting the axial displacement of the air bearing stator. The angle detection component transmits the detected signal to the host computer, which controls the rotation of the rotary motor based on the signal detected by the angle detection component. The displacement detection component transmits the detected signal to the host computer, which controls the movement of the linear voice coil motor based on the signal detected by the displacement detection component, forming a closed-loop control to achieve high-precision control of height and angle, thereby ensuring the quality of the final hot-pressed bonded product.

[0018] Furthermore, a pressure sensor is clamped between the bottom of the mover of the linear voice coil motor and the top of the mover of the air bearing. Force control guide mechanisms are provided on both the left and right sides of the pressure sensor. The force control guide mechanisms are used to ensure that the pressure sensor only bears axial force. The output end of the pressure sensor is connected to the host computer to achieve high-precision pressure feedback.

[0019] Furthermore, each force-controlled guide mechanism includes an upper mounting plate fixed to the linear voice coil motor mover and a lower mounting plate fixed to the top of the air bearing mover. The pressure sensor is located between the bottom end of the linear voice coil motor mover and the lower mounting plate. The bottom surface of the upper mounting plate is provided with a force-controlled guide shaft, and the top surface of the lower mounting plate is provided with a force-controlled guide sleeve adapted to the force-controlled guide shaft. The two form an axial sliding pair, which effectively constrains the radial offset of the linear voice coil motor mover, ensures that the bonding pressure is uniformly transmitted in the vertical direction, eliminates the interference of lateral force on the measurement accuracy of the pressure sensor, and improves the quality of the finished product after the three-dimensional stacking and hot-pressing bonding of the chip.

[0020] Furthermore, the hot-press bonding head also includes a vertically arranged fixing plate, and the rotary drive module includes a fixing cylinder fixed to the upper front side of the fixing plate. The fixing cylinder is sleeved on the rotary motor, and the rear end faces of the two air-bearing guide mounting plates are respectively fixed to the left and right ends of the lower front side of the fixing plate. In use, the fixing plate is fixed to the gantry of the hot-press bonding equipment. By setting the fixing plate, the structure of the hot-press bonding head is integrated and it is convenient to install and fix it as a whole.

[0021] Furthermore, the force control module also includes a bearing retaining ring and a bearing. The bearing retaining ring is integrally fixed to the stator of the linear voice coil motor, and the bearing is fitted onto the stator of the linear voice coil motor. The bearing retaining ring is fixed to the inner ring of the bearing, and multiple pressure plates are circumferentially fixed to the outer ring of the bearing. All pressure plates are fixed to the bottom end of the fixed cylinder, which facilitates better support of the linear voice coil motor and realizes the rotational guidance of the stator of the linear voice coil motor through the bearing, ensuring the coaxiality and stability of the rotational motion.

[0022] The beneficial effects of this invention are as follows: 1) This invention uses a spherical mating pair and a combination of positive and negative pressure air inlets, enabling the leveling component to achieve adaptive deflection, resulting in high leveling efficiency and good parallelism accuracy, effectively avoiding the problem of uneven bonding between the chip and the substrate in the hot-press bonding process; 2) The air-bearing module of this invention uses an air bearing structure with a frictionless and contactless air-bearing support method to ensure the smooth axial movement of the linear voice coil motor's mover, effectively eliminating motion errors caused by mechanical friction, significantly improving the coaxiality and straightness of the bonding motion, and avoiding skewing and lateral deviation problems during the bonding process, providing a basic guarantee for high-precision bonding; 3) The force control module of this invention uses a linear voice coil motor as the core driving element, combined with a pressure sensor at the bottom, to achieve high-precision, high-dynamic-response bonding pressure. The ring control can accurately output the minute pressure required for bonding, avoiding problems such as excessive pressure damaging the chip and insufficient pressure causing bonding failure; 4) The force control guiding mechanism described in this invention ensures that the pressure sensor only bears axial force, eliminating the influence of radial interference force on the pressure feedback accuracy and improving the stability and repeatability of pressure control; 5) The hot-press bonding head described in this invention adopts a modular integrated design of rotary drive module, force control module, air flotation module, leveling module, and heating platform module. Each module has a clear function and independent structure, which is convenient for assembly, debugging and maintenance; each module is reliably connected through couplings, fixed connections and other means. The overall structure is compact and can be adapted to the miniaturization and high-precision packaging requirements of three-dimensional chip stacking. At the same time, it is convenient to upgrade or replace individual modules according to process requirements, improving the versatility and scalability of the equipment. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1This is a schematic diagram of the overall structure of the thermo-press bonding head described in this invention;

[0026] Figure 2 This is a schematic diagram of the overall structure of the rotary drive module described in this invention;

[0027] Figure 3 This is a schematic diagram of the rotary drive module and coupling after removing the fixed cylinder;

[0028] Figure 4 This is a structural diagram of the force control module;

[0029] Figure 5 Schematic diagram of the air flotation module Figure 1 ;

[0030] Figure 6 Schematic diagram of the air flotation module Figure 2 ;

[0031] Figure 7 This is a schematic diagram of a half-section of an air bearing.

[0032] Figure 8 This is a schematic diagram of the leveling module.

[0033] Figure 9 This is a schematic diagram of the leveling component.

[0034] Figure 10 This is a schematic diagram of the assembly structure of the base, the porous spherical surface seat, the magnet, and the two limiting plates.

[0035] Figure 11 This is a schematic diagram of the ring-shaped component.

[0036] In the diagram: 1-Rotary drive module, 101-Rotary motor, 102-Fixed cylinder, 103-Sensor fixing plate, 104-Origin sensor, 105-Positive limit sensor, 106-Negative limit sensor, 107-Coupling, 2-Force control module, 201-Linear voice coil motor, 202-Pressure sensor, 203-Force control guide mechanism, 2031-Upper mounting plate, 2032-Lower mounting plate, 2033-Force control guide shaft, 2034-Force control guide sleeve, 204-Bearing pressure ring, 205-Bearing, 206-Pressure plate, 3-Air bearing module, 301-Air bearing, 3011-Upper moving plate, 3012-Lower moving plate, 3013-Rotating shaft, 3014-Fixed cylinder, 302-Air bearing guide mechanism, 3021-Air bearing bearing. Floating guide mounting plate, 3022-Dovetail slider, 3023-Dovetail guide rail, 303-Weight-counteracting mechanism, 3031-Shaft sleeve seat, 3032-Cylinder, 3033-Support plate, 3034-Air-floating guide shaft, 4-Leveling module, 401-Base seat, 402-Magnet, 403-Leveling component, 404-Porous permeable balloon surface seat, 405-Positive pressure air inlet, 406-Negative pressure air inlet, 407-Ring component, 408-Limiting plate, 409-First limiting notch, 410-First limiting post, 411-Second limiting notch, 412-Second limiting post, 413-Clamping plate, 414-Locking bolt, 415-Mounting notch, 416-Spring, 417-Fixing hole, 5-Heating platform module, 6-Fixing plate. Detailed Implementation

[0037] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0038] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0039] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0040] like Figure 1 , 2 As shown in Figures 3, 4, 5, and 8, a thermocompression bonding head for three-dimensional chip stacking includes:

[0041] The rotary drive module 1 includes a rotary motor 101 whose axis is arranged vertically;

[0042] Force control module 2 includes a linear voice coil motor 201 with its axis arranged vertically. The stator of the linear voice coil motor 201 is connected to the shaft of the rotary motor 101 via a coupling 107.

[0043] The air bearing module 3 includes an air bearing 301 and an air bearing guide mechanism 302. The top of the moving part of the air bearing 301 is fixed to the bottom of the moving part of the linear voice coil motor 201. The air bearing guide mechanism 302 is used to ensure that the stator of the air bearing 301 can only move axially.

[0044] The leveling module 4 includes a base 401, a leveling component 403, a magnet 402 for adsorbing the leveling component 403, and a limiting mechanism. The bottom of the mover of the air bearing 301 is fixed to the top surface of the base 401. The bottom surface of the base 401 is provided with a ball groove, and a porous, permeable spherical surface seat 404 with a spherical bottom is installed in the ball groove. The porous, permeable spherical surface seat 404 has a central hole, and the magnet 402 is installed in the ball groove through the central hole. The top end of the leveling component 403 is spherical and fits into the porous, permeable spherical surface seat 404. A spherical mating pair is formed. The base 401 is provided with a positive pressure air port 405 and a negative pressure air port 406. Compressed air introduced through the positive pressure air port 405 is evenly output through the porous permeable spherical seat 404 and forms a uniform air film between the porous permeable spherical seat 404 and the leveling component 403. Negative pressure gas is introduced through the negative pressure air port 406 and the gas is evenly drawn through the porous permeable spherical seat 404, so that the leveling component 403 is negatively locked to the porous permeable spherical seat 404. The limiting mechanism is used to limit the circumferential rotation of the leveling component 403.

[0045] Heating platform module 5 is fixed to the bottom end of leveling component 403 and is used to adsorb the chip and heat the chip.

[0046] Principle Description: In use, both the rotary motor 101 and the air-bearing guide mechanism 302 are fixed to the gantry of the hot-press bonding equipment. The rotary drive module 1 mainly uses the rotary motor 101 to rotate the hot-press bonding head; the force control module 2 mainly uses the linear voice coil motor 201 to press down the hot-press bonding head; the rotary motor 101 and the linear voice coil motor 201 are connected by a coupling 107, so that when the rotary motor 101 rotates, it drives the linear voice coil motor 201 to rotate; the air-bearing module 3 is installed at the bottom of the linear voice coil motor 201, mainly used to counteract the load installed below the linear voice coil motor 201. The linear voice coil motor 201 achieves high-precision downward pressure control. When the linear voice coil motor 201 rotates along with the rotary motor 101, the mover of the air bearing 301 also rotates. By introducing compressed air into the air bearing 301, rotation with near-zero friction is achieved. Simultaneously, when the mover of the linear voice coil motor 201 presses down, it drives the air bearing 301 to press down. The leveling module 4, during use, uses the heating stage assembly to adsorb the chip, and then the positive pressure air inlet 405 is opened. Compressed air is uniformly output through the porous spherical surface holder 404, forming a uniform air film between the porous spherical surface holder 404 and the leveling component 403. At this time, the leveling component 403 is only subject to the weak pre-tightening adsorption force provided by the magnet 402. The air film eliminates the mechanical frictional resistance between the spherical surfaces, allowing the leveling component 403 to automatically adjust its angle according to the bonding surface between the chip and the substrate, achieving unconstrained adaptive leveling. At the same time, the limiting mechanism restricts the circumferential rotation of the leveling component 403 around the vertical axis. To prevent deflection during adjustment, after leveling, close the positive pressure air inlet 405 and open the negative pressure air inlet 406. Gas is evenly drawn through the porous permeable spherical seat 404, evacuating the air film between the porous permeable spherical seat 404 and the leveling component 403 to form a uniform vacuum adsorption force. With the assistance of the magnet 402, the leveling component 403 is rigidly locked onto the porous permeable spherical seat 404, and the posture of the spherical pair is completely fixed, ensuring stable leveling accuracy and no deviation in subsequent processes.

[0047] In specific implementation, such as Figure 6 As shown, the air flotation module 3 also includes a self-weight offsetting mechanism 303 fixed to the air flotation guide mechanism 302. The self-weight offsetting mechanism 303 is used to support the force control module. The self-weight offsetting mechanism 303 is used to further offset the load of the force control module 2, to prevent the linear voice coil motor 201 from continuously supplying a large current to offset the load, and to prevent the linear voice coil motor 201 from overheating. At the same time, a large load will also cause the linear voice coil motor 201 to respond slowly, affecting the downward positioning of the linear voice coil motor 201's mover.

[0048] In practical implementation, the air-bearing guide mechanism 302 includes two air-bearing guide mounting plates 3021 and two dovetail-shaped sliders 3022 respectively fixed to the left and right side walls of the stator of the air bearing 301. One side of each of the two air-bearing guide mounting plates 3021 is provided with a dovetail-shaped guide rail 3023 adapted to the dovetail-shaped slider 3022. In use, both air-bearing guide mounting plates 3021 are fixed to the gantry of the hot-press bonding equipment. The structure of the air-bearing guide mechanism 302 is specific, simple, and easy to implement.

[0049] In specific implementation, the self-weight offsetting mechanism 303 includes a bushing seat 3031 fixed to the other side of one of the air-bearing guide mounting plates 3021. A support plate 3033 is supported above the bushing seat 3031 by a cylinder 3032. The support plate 3033 is provided with an air-bearing guide shaft 3034 that is axially slidably connected to the bushing seat 3031. The top surface of the support plate 3033 abuts against the bottom surface of the force control module 2. In use, the cylinder 3032 supports the support plate 3033 upward, further offsetting the load of the linear voice coil motor 201 and preventing the linear voice coil motor 201 from continuously supplying a large current to offset the load.

[0050] In specific implementation, the air flotation module 3 also includes an angle detection component for detecting the rotation angle of the mover of the air bearing 301 and a displacement detection component for detecting the axial displacement of the stator of the air bearing 301. The angle detection component transmits the detected signal to the host computer, which controls the rotation of the rotary motor 101 based on the signal detected by the angle detection component. The displacement detection component transmits the detected signal to the host computer, which controls the movement of the linear voice coil motor 201 based on the signal detected by the displacement detection component, forming a closed-loop control to achieve high-precision control of height and angle, thereby ensuring the quality of the final hot-pressed bonded product.

[0051] In specific implementation, a pressure sensor 202 is also clamped between the bottom of the mover of the linear voice coil motor 201 and the top of the mover of the air bearing 301. Force control guide mechanisms 203 are provided on both the left and right sides of the pressure sensor 202. The force control guide mechanisms 203 are used to ensure that the pressure sensor 202 only bears axial force. The output end of the pressure sensor 202 is connected to the host computer to realize high-precision pressure feedback.

[0052] In specific implementation, each force-controlled guide mechanism 203 includes an upper mounting plate 2031 fixed to the mover of the linear voice coil motor 201 and a lower mounting plate 2032 fixed to the top of the mover of the air bearing 301. The pressure sensor 202 is located between the bottom end of the mover of the linear voice coil motor 201 and the lower mounting plate 2032. The bottom surface of the upper mounting plate 2031 is provided with a force-controlled guide shaft 2033, and the top surface of the lower mounting plate 2032 is provided with a force-controlled guide sleeve 2034 adapted to the force-controlled guide shaft 2033. The two form an axial sliding pair, which effectively constrains the radial offset of the mover of the linear voice coil motor 201, ensures that the bonding pressure is uniformly transmitted in the vertical direction, eliminates the interference of lateral force on the measurement accuracy of the pressure sensor 202, and improves the quality of the finished product after the three-dimensional stacking and hot-pressing bonding of the chip.

[0053] In practical implementation, the hot-press bonding head also includes a vertically arranged fixing plate 6, and the rotary drive module 1 includes a fixing cylinder 102 fixed to the upper front side of the fixing plate 6. The fixing cylinder 102 is sleeved on the rotary motor 101, and the rear end faces of the two air-bearing guide mounting plates 3021 are respectively fixed to the left and right ends of the lower front side of the fixing plate 6. In use, the fixing plate 6 is fixed to the gantry of the hot-press bonding equipment. By setting the fixing plate 6, the structure of the hot-press bonding head is integrated and it is convenient to install and fix it as a whole.

[0054] In specific implementation, the force control module 2 also includes a bearing pressure ring 204 and a bearing 205. The bearing pressure ring 204 is integrally fixed to the stator of the linear voice coil motor 201, and the bearing 205 is fitted to the stator of the linear voice coil motor 201. The bearing pressure ring 204 is fixed to the inner ring of the bearing 205, and multiple pressure plates 206 are circumferentially fixed to the outer ring of the bearing 205. The multiple pressure plates 206 are all fixed to the bottom end of the fixed cylinder 102, which facilitates better support of the linear voice coil motor 201 and realizes the rotational guidance of the stator of the linear voice coil motor 201 through the bearing 205, ensuring the coaxiality and stability of the rotational motion.

[0055] In this specific embodiment, the rotary drive module 1 further includes an origin sensor 104, a positive limit sensor 105, and a negative limit sensor 106. A sensor fixing plate 103 is fixed to the bottom end of the fixed cylinder 102. The origin sensor 104, positive limit sensor 105, and negative limit sensor 106 are all mounted on the sensor fixing plate 103 and are respectively used to achieve zero-position return of the rotary motor 101, positive stroke limit protection, and negative stroke limit protection, thereby improving the rotational accuracy of the rotary drive module 1. In this specific embodiment, to make the thermocouple head more stable, the axial length of the fixed cylinder 102 is relatively long, and the bottom end of the fixed cylinder 102 corresponds to the stator position of the linear voice coil motor 201. This means that the origin sensor 104, positive limit sensor 105, and negative limit sensor 106 detect the rotational position of the stator of the linear voice coil motor 201. Since the linear voice coil stator is fixedly connected to the rotary motor 101 via a coupling, the detected rotational position of the linear voice coil motor 201 stator is equivalent to the detected rotational position of the rotary motor 101.

[0056] In this specific implementation, such as Figure 7 As shown, the moving part of the air bearing 301 includes an upper moving plate 3011, a lower moving plate 3012, and a rotating shaft 3013. The upper moving plate 3011 and the lower moving plate 3012 are arranged horizontally and vertically. The rotating shaft 3013 is fixed between the upper moving plate 3011 and the lower moving plate 3012. The stator of the air bearing 301 is a fixed cylinder 3014 adapted to the rotating shaft 3013. The inner wall of the fixed cylinder 3014 has a circular cross-section, and the outer wall of the fixed cylinder 3014 has a square cross-section. Air film gaps are provided between the rotating shaft 3013 and the fixed cylinder 3014, between the top surface of the upper moving plate 3011 and the fixed cylinder 3014, and between the bottom surface of the lower moving plate 3012 and the fixed cylinder 3014. The fixed cylinder 3014 has an air inlet that communicates with the air film gap. This air bearing 301 has a simple structure and is easy to manufacture.

[0057] In this specific implementation, such as Figure 9 , 10As shown in Figure 11, the limiting mechanism includes a ring-shaped component 407 and two limiting plates 408. The ring-shaped component 407 is movably fitted onto the bottom end of the leveling component 403. The top surface of the ring-shaped component 407 has first limiting notches 409 on both the left and right sides. One end of each of the two limiting plates 408 is fixed to the left and right sides of the base 401, respectively. The inner sides of the other ends of each of the two limiting plates 408 are fixed with first limiting posts 410 that are adapted to the first limiting notches 409. The depth in the height direction of the ring part 407 is greater than the diameter of the first limiting post 410. The front and rear sides of the top surface of the ring part 407 are provided with second limiting notches 411. The bottom end of the leveling part 403 is cylindrical and the circumferential surface of the bottom end of the leveling part 403 is provided with two second limiting posts 412 that are respectively adapted to the two second limiting notches 411. The depth in the height direction of the second limiting notch 411 is greater than the diameter of the second limiting post 412, thereby restricting the leveling part 403 from rotating circumferentially around the vertical axis.

[0058] In this specific embodiment, the limiting mechanism also includes a clamping plate 413. The clamping plate 413 is fixed to the bottom end of the leveling component 403, and the edge of the top surface of the clamping plate 413 blocks the bottom surface of the annular component 407. The other ends of both limiting plates 408 are also fixed with locking bolts 414 for locking the clamping plate 413 during transport. During transport, the negative pressure air inlet 406 is not ventilated, and the leveling component 403 cannot be effectively fixed by the magnet 402 alone. Furthermore, since the annular component 407 has no fixed structure, it can only be disassembled and cannot be transported as a whole. Therefore, the clamping plate 413 is added to fix the annular component 407 and the leveling component 403, facilitating transport. The bottom surface of the annular component 407 has multiple mounting notches 415 evenly distributed circumferentially. Each mounting notch 415 is provided with a spring 416 axially arranged in the vertical direction between itself and the top surface of the clamping plate 413, improving the stability during leveling.

[0059] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. A thermocompression bonding head for three-dimensional chip stacking, characterized in that, include: A rotary drive module (1) includes a rotary motor (101) whose axis is arranged vertically. The force control module (2) includes a linear voice coil motor (201) with its axis arranged vertically. The stator of the linear voice coil motor (201) is connected to the shaft of the rotary motor (101) via a coupling (107). The air bearing module (3) includes an air bearing (301) and an air bearing guide mechanism (302). The top of the mover of the air bearing (301) is fixed to the bottom of the mover of the linear voice coil motor (201). The air bearing guide mechanism (302) is used to ensure that the stator of the air bearing (301) can only move axially. The leveling module (4) includes a base (401), a leveling component (403), a magnet (402) for adsorbing the leveling component (403), and a limiting mechanism. The bottom of the mover of the air bearing (301) is fixed to the top surface of the base (401). The bottom surface of the base (401) is provided with a ball groove. A porous, permeable balloon surface seat (404) with a spherical bottom is installed in the ball groove. The center of the porous, permeable balloon surface seat (404) is provided with a central hole. The magnet (402) is installed in the ball groove through the central hole. The top part of the leveling component (403) is spherical and fits into the porous, permeable balloon surface seat (404). To form a spherical mating pair, the base (401) is provided with a positive pressure air port (405) and a negative pressure air port (406). Compressed air introduced through the positive pressure air port (405) is uniformly output through the porous permeable spherical seat (404) and forms a uniform air film between the porous permeable spherical seat (404) and the leveling component (403). Negative pressure gas is introduced through the negative pressure air port (406) and the gas is uniformly extracted through the porous permeable spherical seat (404) to realize the negative pressure locking of the leveling component (403) to the porous permeable spherical seat (404). The limiting mechanism is used to limit the circumferential rotation of the leveling component (403). Heating platform module (5), which is fixed to the bottom end of leveling component (403) and is used to adsorb the chip and heat the chip.

2. The thermocompression bonding head for three-dimensional chip stacking according to claim 1, characterized in that, The air flotation module (3) also includes a self-weight offsetting mechanism (303) fixed on the air flotation guide mechanism (302), which is used to support the force control module.

3. The thermocompression bonding head for three-dimensional chip stacking according to claim 2, characterized in that, The air-bearing guide mechanism (302) includes two air-bearing guide mounting plates (3021) and two dovetail sliders (3022) respectively fixed to the left and right side walls of the stator of the air bearing (301). One side of each of the two air-bearing guide mounting plates (3021) is provided with a dovetail guide rail (3023) that is compatible with the dovetail slider (3022).

4. A thermocompression bonding head for three-dimensional chip stacking according to claim 3, characterized in that, The self-weight offset mechanism (303) includes a bushing seat (3031) fixed to the other side of one of the air-bearing guide mounting plates (3021). A support plate (3033) is supported above the bushing seat (3031) by a cylinder (3032). The support plate (3033) is provided with an air-bearing guide shaft (3034) that is axially slidably connected to the bushing seat (3031). The top surface of the support plate (3033) abuts against the bottom surface of the force control module (2).

5. A thermocompression bonding head for three-dimensional chip stacking according to claim 4, characterized in that, The air flotation module (3) also includes an angle detection component for detecting the rotation angle of the mover of the air bearing (301) and a displacement detection component for detecting the axial displacement of the stator of the air bearing (301). The angle detection component transmits the detected signal to the host computer, and the host computer controls the rotation of the rotary motor (101) according to the signal detected by the angle detection component. The displacement detection component transmits the detected signal to the host computer, and the host computer controls the movement of the linear voice coil motor (201) according to the signal detected by the displacement detection component.

6. A thermocompression bonding head for three-dimensional chip stacking according to claim 5, characterized in that, A pressure sensor (202) is also clamped between the bottom of the mover of the linear voice coil motor (201) and the top of the mover of the air bearing (301). Force control guide mechanisms (203) are provided on both the left and right sides of the pressure sensor (202). The force control guide mechanisms (203) are used to ensure that the pressure sensor (202) only bears axial force. The output end of the pressure sensor (202) is connected to the host computer.

7. A thermocompression bonding head for three-dimensional chip stacking according to claim 6, characterized in that, Each force control guide mechanism (203) includes an upper mounting plate (2031) fixed to the mover of the linear voice coil motor (201) and a lower mounting plate (2032) fixed to the top of the mover of the air bearing (301). The pressure sensor (202) is located between the bottom end of the mover of the linear voice coil motor (201) and the lower mounting plate (2032). The bottom surface of the upper mounting plate (2031) is provided with a force control guide shaft (2033), and the top surface of the lower mounting plate (2032) is provided with a force control guide sleeve (2034) adapted to the force control guide shaft (2033).

8. A thermocompression bonding head for three-dimensional chip stacking according to claim 7, characterized in that, The hot-press bonding head also includes a vertically arranged fixing plate (6), and the rotary drive module (1) also includes a fixing cylinder (102) fixed to the upper front side of the fixing plate (6). The fixing cylinder (102) is sleeved on the rotary motor (101), and the rear end faces of the two air-bearing guide mounting plates (3021) are respectively fixed to the left and right ends of the lower front side of the fixing plate (6).

9. A thermocompression bonding head for three-dimensional chip stacking according to claim 8, characterized in that, The force control module (2) also includes a bearing pressure ring (204) and a bearing (205). The bearing pressure ring (204) is integrally fixed to the stator of the linear voice coil motor (201). The bearing (205) is fitted to the stator of the linear voice coil motor (201). The bearing pressure ring (204) is fixed to the inner ring of the bearing (205). Multiple pressure plates (206) are fixed to the outer ring of the bearing (205) in a circumferential direction. The multiple pressure plates (206) are all fixed to the bottom end of the fixed cylinder (102).

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