A coaxial decoupling self-adapting pressure head mechanism for flip-chip bonding

Abstract

The application discloses a coaxial decoupling self-adaptive pressure head mechanism for flip-chip bonding, which comprises a quick-change flange joint, a micro-deformation force connecting piece, a floating frame, a flexible hinge, a pressure head mounting seat and a rubber elastic body. The quick-change flange joint is connected with the floating frame through the micro-deformation force connecting piece. The floating frame is internally provided with a containing cavity, the flexible hinge is arranged in the containing cavity, the pressure head mounting seat is rotationally assembled on the flexible hinge, the pressure head mounting seat is internally provided with an air cavity, the bottom of the pressure head mounting seat is provided with a mounting cavity, and the mounting cavity is provided with micro-holes. The rubber elastic body is arranged in the mounting cavity. The coaxial decoupling self-adaptive pressure head mechanism for flip-chip bonding is matched with the rubber elastic body through the mounting cavity of the pressure head mounting seat, contact stress uniform distribution is realized, the micro-hole array on the mounting cavity provides the rubber elastic body with a volume allowance required by thermal expansion, and pressure balance is ensured, so that full-field microscopic conformal wrapping of a warped wafer is realized, and full-field macroscopic residual stress is reduced to below 5 MPa.

Description

Technical Field

[0001] This invention relates to the field of flip-chip bonding equipment, and more particularly to a coaxial decoupling adaptive pressure head mechanism for flip-chip bonding. Background Technology

[0002] With the evolution of 3D integrated circuit and quantum computing packaging technologies, wafer-to-wafer bonding and die-to-wafer bonding with high-density microbumps with a pitch of 10-30 micrometers have become core processes. Especially for 12-inch (300mm) large-size wafers, the bonding process places extremely high demands on the uniformity of pressure across the entire field, temperature gradient, and equipment rigidity.

[0003] Existing general-purpose bonding equipment generally suffers from the following common industry problems: (1) Stress concentration and breakage problems caused by warping of large-size wafers. Large-size wafers will experience macroscopic warping when heated or subjected to pressure. Existing pressure heads mostly use discrete elastic compensation methods such as spring arrays and segmented airbags, or use rigid grid bases. These structures cannot achieve absolutely continuous pressure distribution across the entire field. The "waffle effect" is very likely to occur at the grid partitions or rigid connections, causing local microbumps to be crushed and residual stress to exceed 10MPa, which in turn leads to chip decoherence or severe breakage.

[0004] (2) Thermal expansion displacement accumulation and temperature gradient damage problem. During the bonding process at 150-300℃, the wafer undergoes a large lateral thermal expansion displacement, and there is a large temperature gradient between the metal indenter and the wafer at the moment of contact. This results in a large temperature gradient and irreversible thermal shear stress in the thickness direction of the wafer, which seriously threatens the integrity of the bonding interface.

[0005] (3) The dual pollution problem of magnetic materials and organic matter release. Advanced processes, represented by quantum chips, are extremely sensitive to cleanliness and electromagnetic environment. Traditional pressure heads generally contain ferromagnetic materials, which are prone to magnetic flux vortex interference; at the same time, rubber adhesives are often used, which release small molecule organic volatiles at high temperatures, which seriously shorten the device life and quantum coherence time.

[0006] (4) The physical contradiction between high stiffness and high precision force control. Advanced packaging machine tools require the pressure head to have extremely high macroscopic structural stiffness to suppress vibration. However, under the background of high stiffness structure, when extracting extremely small high-frequency dynamic contact force signals on the order of 0.1mN, they are easily submerged by mechanical noise and pyroelectric drift, making it difficult to achieve true closed-loop control and failing to meet the requirements of precise bonding force control. Summary of the Invention

[0007] The purpose of this invention is to propose a coaxial decoupled adaptive pressure head mechanism for flip-chip bonding, in order to solve the problem that existing pressure head mechanisms cannot simultaneously ensure continuous and uniform pressure across the entire field in large-size wafer bonding, adapt to thermal expansion, be compatible with ultra-clean and non-magnetic environments, and accurately sense minute forces under high stiffness.

[0008] To achieve this objective, the present invention adopts the following technical solution: This invention provides a coaxial decoupling adaptive pressure head mechanism for inverted bonding, comprising a quick-change flange joint, a micro-deformation force connector, a floating frame, a flexible hinge, a pressure head mounting base, and a rubber elastomer; The quick-change flange joint is connected to the floating frame via a micro-deformation force connector; the floating frame has a receiving cavity, the flexible hinge is disposed in the receiving cavity, and the pressure head mounting seat is rotatably assembled to the bottom of the flexible hinge; The pressure head mounting base has an air cavity inside, and one side of the pressure head mounting base has an interface communicating with the air cavity; the top surface of the pressure head mounting base has an air outlet communicating with the air cavity; the bottom of the pressure head mounting base has an installation cavity, and the bottom of the installation cavity has multiple micropores communicating with the air cavity; the rubber elastomer is disposed in the installation cavity.

[0009] In the inverted bonding coaxial decoupling adaptive pressure head mechanism, the micro-deformation force connector includes several spring plates, the cross-section of which is arc-shaped; the several spring plates are distributed circumferentially along the floating frame, one end of each spring plate is connected to a quick-change flange joint, and the other end of each spring plate is connected to the floating frame.

[0010] In the inverted bonding coaxial decoupling adaptive pressure head mechanism, the flexible hinge includes a hinge body, a first hinge arm unit, and a second hinge arm unit. The first hinge arm unit is located above the second hinge arm unit. Both the first and second hinge arm units include several hinge arms. One end of each hinge arm is connected to the side wall of the hinge body, and the other end of each hinge arm is connected to the inner wall of the accommodating cavity.

[0011] In the inverted bonding coaxial decoupling adaptive pressure head mechanism, the pressure head mounting base is provided with a mandrel and an oxygen-free copper sleeve, the hinge body is provided with a rotating shaft mounting groove, the upper end of the mandrel is detachably connected to the rotating shaft mounting groove, and the lower end of the mandrel is fixedly connected to the pressure head base; the oxygen-free copper sleeve is sleeved on the outer periphery of the mandrel and embedded in the rotating shaft mounting groove.

[0012] In the aforementioned coaxial decoupling adaptive pressure head mechanism for flip bonding, the pressure head mounting base further includes a piezoelectric ceramic crystal stack, which is sleeved on the outer periphery of the mandrel and disposed between the mandrel and the oxygen-free copper sleeve. The piezoelectric ceramic crystal stack is electrically connected to an external bonding device.

[0013] In the inverted bonding coaxial decoupling adaptive pressure head mechanism, the pressure head mounting base further includes a zirconia pad, which is sleeved on the outer periphery of the piezoelectric ceramic crystal stack; both the piezoelectric ceramic crystal stack and the zirconia pad are disposed between the mandrel and the oxygen-free copper sleeve, with the zirconia pad located below the piezoelectric ceramic crystal stack; the thickness of the zirconia pad is 2-3 mm.

[0014] In the inverted bonding coaxial decoupling adaptive pressure head mechanism, the rubber elastomer includes a material box and an elastomer body. The material box has an elastomer mounting port in the middle, and the elastomer body is disposed in the elastomer mounting port, with the top surface of the elastomer body closely attached to the bottom of the mounting cavity. The material box is detachably installed in the mounting cavity.

[0015] In the inverted bonding coaxial decoupling adaptive pressure head mechanism, the inner wall of the mounting cavity is provided with two spring holes, which are arranged opposite to each other; a spring ball plunger is provided in the spring hole, and the outer wall of the material box is provided with a clearance groove that matches the number and position of the spring ball plunger; the material box and the pressure head mounting seat are detachably connected through the spring ball plunger and the clearance groove.

[0016] In the inverted bonding coaxial decoupling adaptive pressure head mechanism, the bottom surface of the elastomer body is provided with a Parylene conformal coating, the thickness of which is 5 to 15 micrometers.

[0017] In the inverted bonding coaxial decoupling adaptive pressure head mechanism, the depth of the mounting cavity is 0.7-1.0 mm, the bottom of the material box is flush with the edge of the mounting cavity, and the elastomer body protrudes 0.01-0.02 mm from the edge of the mounting cavity.

[0018] One of the technical solutions in this invention can have the following beneficial effects: The flip-chip bonding coaxial decoupling adaptive pressure head mechanism cooperates with the rubber elastomer through the mounting cavity of the pressure head mounting seat to achieve uniform contact stress distribution. The micropore array and cavitation on the mounting cavity provide the rubber elastomer with the volume margin required for thermal expansion and ensure pressure balance, thereby achieving full-field micro-conformal wrapping of the warped wafer and reducing the full-field macroscopic residual stress to below 5MPa. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of one embodiment of the present invention; Figure 2 This is a cross-sectional schematic diagram of one embodiment of the present invention; Figure 3 yes Figure 2 A magnified view of a section at point A in the middle; Figure 4This is a schematic diagram of the internal structure of one embodiment of the present invention; Figure 5 This is a bottom view of one embodiment of the present invention; Figure 6 This is a cross-sectional schematic diagram of a flexible hinge in one embodiment of the present invention; Figure 7 This is a schematic diagram illustrating the operation of one embodiment of the present invention; In the attached diagram: 1. Quick-change flange connector; 2. Micro-deformation force connector; 3. Floating frame; 4. Flexible hinge; 5. Pressure head mounting base; 6. Rubber elastomer; 7. Flip-chip; 8. Substrate to be bonded; 9. Spring ball plunger. Spring sheet 21; receiving cavity 30; hinge body 41; hinge arm 42; cavitation 51; interface 52; vent 53; micropore 54; mandrel 55; oxygen-free copper sleeve 56; piezoelectric ceramic crystal stack 57; zirconia pad 58; material box 61; elastomer body 62; Piriton conformal coating 63; shaft mounting groove 410. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0021] In the description of this invention, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, features defined with "first" and "second" may explicitly or implicitly include one or more of these features, used to distinguish and describe features, without any order or emphasis.

[0022] In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Please refer to Figures 1-7 The present invention provides a coaxial decoupling adaptive pressure head mechanism for inverted bonding, including a quick-change flange joint 1, a micro-deformation force connector 2, a floating frame 3, a flexible hinge 4, a pressure head mounting base 5, and a rubber elastomer 6; The quick-change flange joint 1 and the floating frame 3 are connected by a micro-deformation force connector 2; the floating frame 3 is provided with a receiving cavity 30, the flexible hinge 4 is disposed in the receiving cavity 30, and the pressure head mounting seat 5 is rotatably assembled on the bottom of the flexible hinge 4. The pressure head mounting base 5 has an air cavity 51 inside, and one side of the pressure head mounting base 5 has an interface 52 communicating with the air cavity 51; the top surface of the pressure head mounting base 5 has an air outlet 53 communicating with the air cavity 51; the bottom of the pressure head mounting base 5 has an installation cavity, and the bottom of the installation cavity has a plurality of microholes 54 communicating with the air cavity 51; the rubber elastomer 6 is disposed in the installation cavity.

[0025] The components and fasteners of the flip-bonded coaxial decoupling adaptive pressure head mechanism are all made of non-magnetic materials, such as beryllium bronze, TC4 titanium alloy, or oxygen-free copper. The top of the quick-change flange connector 1 is equipped with a non-magnetic interface flange, which adopts a large conical surface positioning and mechanical self-locking structure, allowing for rapid offline replacement of pressure head modules of different wafer or chip process sizes, while ensuring repeatability and mechanical stiffness transmission after replacement.

[0026] On the bottom of the mounting cavity, hundreds of micropores 54 are evenly distributed, forming a compensating micropore array. The diameter of the micropores is 10-50 μm, leading to the air cavity 51. The rubber elastomer 6 is specifically perfluoroether rubber. Utilizing the viscoelastic frequency response characteristics of the rubber elastomer 6, under the condition of rapid contact and force application by the pressure head, the rubber elastomer 6 exhibits an extremely high transient bulk modulus, demonstrating high rigidity mechanical transmission characteristics. During the pressure holding stage, under the condition of slow temperature rise, the redundant part of the rubber elastomer 6 that expands due to heat is in a viscous flow state, slowly creeping and overflowing into the air cavity 51 above through the micropore array, preventing large-area bulging of the rubber elastomer 6 due to heat, which would damage the flatness of the contact surface.

[0027] The flip-chip bonding coaxial decoupling adaptive pressure head mechanism cooperates with the rubber elastomer 6 through the mounting cavity of the pressure head mounting seat 5 to achieve uniform distribution of contact stress. The micro-pore array and cavitation 51 on the mounting cavity provide the rubber elastomer 6 with the volume margin required for thermal expansion and ensure pressure balance, thereby achieving full-field micro-conformal wrapping of the warped wafer and reducing the full-field macroscopic residual stress to below 5MPa.

[0028] To prevent the internal gas from expanding rapidly due to high temperature and being ejected from the rubber elastomer 6 due to the air pocket 51 being sealed, an interface 52 is installed on one side of the air pocket 51, and an air outlet 53 is provided on the top of the pressure head mounting base 5. The air outlet 53 ensures that the pressure inside the air pocket 51 is connected to the external nitrogen gas source when the rubber elastomer 6 expands under heat and pressure. Interface 52 has two working states: When the rubber elastomer 6 is in the expansion stage, air is drawn into the air cavity 51 to maintain a negative pressure inside the air cavity 51, guiding the rubber elastomer 6 to deform towards the air cavity 51, preventing the rubber elastomer 6 from bulging due to large-area heating, thereby avoiding damage to the flatness of the contact surface of the rubber elastomer 6; When the rubber elastomer 6 is in the contraction stage, nitrogen is continuously injected into the air cavity 51 through interface 52 to maintain a positive pressure inside the air cavity 51, preventing the rubber elastomer 6 from generating suction when contracting and drawing environmental micro-pollutant particles into the air cavity 51, thereby avoiding the problem of micropore blockage in the micropore array, and forming an oxygen-free or low-oxygen environment, delaying the oxidation of the rubber elastomer 6, and also helping the rubber elastomer 6 to recover its shape.

[0029] The workflow of the inverted bonding coaxial decoupling adaptive pressure head mechanism includes: Chip placement: The flip chip 7 is placed on the substrate 8 to be bonded. The substrate 8 is heated by the main heating mechanism, and the flip chip 7 undergoes slight thermal deformation due to the heat. Press head mechanism movement: The flip bonding coaxial decoupling adaptive press head mechanism moves above the flip chip 7; there is a heating device on the substrate to be bonded to help melt the solder joints. During the movement, the flip bonding coaxial decoupling adaptive press head mechanism is heated by the overall working environment temperature rise. During this preheating stage, the rubber elastomer 6 inside the mounting cavity expands due to heat. Because the deformation is at a low speed, the redundant volume of the rubber elastomer 6 flows uniformly into the air cavity 51 in a viscous flow state through the 10–50 μm micropore array at the bottom, ensuring a smooth bottom interface. The zirconia pad 58 blocks heat conduction to the piezoelectric ceramic crystal stack 57 and the mandrel 55 above.

[0030] Pressing: The pressure head mechanism continues to press downwards, maintaining a certain pressure. Upon contact with the back of the flip chip 7, warping or unevenness may occur due to slight deformation from heat or unevenness of the bottom bumps. During the contact process, the unbalanced force is first transmitted through the rubber elastomer 6 and the pressure head mounting base 5 to the spindle 55, zirconia pad 58, and piezoelectric ceramic stack 57. After contact, the coaxial decoupling adaptive pressure head mechanism for flip bonding is further heated. Due to the rapid pressing contact of the pressure head mechanism, the rubber elastomer 6 exhibits an extremely high transient bulk modulus and cannot pass through the micropore array, instantly generating hyperelastic conformal pressure equalization. The high-temperature pyrene conformal coating 63 on the surface of the rubber elastomer 6 seamlessly adheres to the chip surface contour, achieving effective pressure equalization. The piezoelectric ceramic stack 57 can measure the pressure signal generated at this time and transmit it to the host, realizing closed-loop pressure control.

[0031] The unbalanced force is mainly transmitted coaxially through the mandrel 55, and partly through the zirconia pad 58, the piezoelectric ceramic crystal stack 57 and the oxygen-free copper sleeve 56, forming a resultant force on the central axis of the flexible hinge 4.

[0032] The unbalanced force consists of two main parts: first, a longitudinal force with a small angle to the vertical direction, generated by the thermal micro-deformation of the flip chip 7 or the unevenness of the bottom bumps; and second, a horizontal shear stress generated by the compressive deformation of the surface, bumps, and substrate 8 of the flip chip 7. When the unbalanced force is transmitted to the central axis of the flexible hinge 4, the longitudinal force and the horizontal shear stress are decoupled here because the flexible hinge 4 has high rigidity in the vertical direction but can undergo micro-deformation in the horizontal direction: the longitudinal force continues to be transmitted to the floating frame 3 and the micro-deformation force connector 2; while the horizontal shear stress is passively relieved by the small deformation of the hinge arm 42 of the flexible hinge 4 through the horizontal elastic micro-movement of the upper and lower parallel structures of the flexible hinge 4, without generating a parasitic tilt angle. The longitudinal force is transmitted to the micro-deformation force connector 2 through the floating frame 3, and the micro-deformation of the micro-deformation force connector 2 withstands the passive deflection of the floating frame 3 to adapt to the macroscopic tilt angle of the flip chip 7. During the pressure holding stage, the micro-deformation force connector 2 and the flexible hinge 4, under the decoupling effect of micro-deformation force, continuously maintain the pressure head mechanism to effectively achieve pressure equalization for flip chip bonding.

[0033] After the holding pressure phase ends, the pressure head mechanism lifts and returns to its original position. Once the environment has cooled, the bonded flip chip can be removed, ready for the next batch of chips to be bonded, thus beginning the next work cycle.

[0034] Specifically, the micro-deformation force connector 2 includes a plurality of spring plates 21, the cross-section of which is arc-shaped; the plurality of spring plates 21 are distributed at intervals along the circumference of the floating frame 3, one end of the spring plate 21 is connected to the quick-change flange connector 1, and the other end of the spring plate 21 is connected to the floating frame 3.

[0035] In one specific embodiment of the present invention, three spring plates 21 are used, which are distributed circumferentially at 120° intervals. The spring plates 21 are made of beryllium bronze and are arc-shaped. They provide equidirectional reset force through three-point kinematic support and have a omnidirectional deflection capability of ±5°, which is used to passively absorb macroscopic parallelism deviations between the wafer and the pressure head.

[0036] Specifically, the flexible hinge 4 is provided with a hinge body 41, a first hinge arm unit and a second hinge arm unit; the first hinge arm unit is located above the second hinge arm unit, and both the first hinge arm unit and the second hinge arm unit include a plurality of hinge arms 42, one end of the hinge arm 42 is connected to the side wall of the hinge body 41, and the other end of the hinge arm 42 is connected to the inner wall of the accommodating cavity 30.

[0037] In a specific embodiment of the present invention, the flexible hinge 4 is integrally wire-cut from TC4 titanium alloy. The hinge arm 42 is a sheet-like shape that is thicker longitudinally and thinner laterally, with a cut thickness of 0.8–1.2 mm. The end of the hinge arm 42 connected to the hinge body 41 has a large arc transition end to achieve an anti-instability effect. The first hinge arm unit and the second hinge arm unit are a double-layer structure, maintaining high force transmission stiffness in the vertical direction while allowing elastic micro-deformation in the horizontal direction. This completely eliminates parasitic tilt angles and passively unloads the shear stress caused by lateral thermal expansion displacement.

[0038] Specifically, the pressure head mounting base 5 is provided with a mandrel 55 and an oxygen-free copper sleeve 56, the hinge body 41 is provided with a pivot mounting groove 410, the upper end of the mandrel 55 is detachably connected to the pivot mounting groove 410, and the lower end of the mandrel 55 is fixedly connected to the pressure head base; the oxygen-free copper sleeve 56 is sleeved on the outer periphery of the mandrel 55 and embedded in the pivot mounting groove 410.

[0039] The hinge body 41, spindle 55, and oxygen-free copper sleeve 56 adopt a coaxial nesting design. The upper end of the spindle 55 and the shaft mounting groove 410 are both threaded. The upper end of the spindle 55 is threadedly connected to the shaft mounting groove 410 of the hinge body 41, and the lower end of the spindle 55 is fixedly connected to the pressure head base. The spindle 55 and the pressure head base are integrally formed. When the spindle 55 is tightened, a certain preload is maintained between the piezoelectric ceramic crystal stack 57 and the oxygen-free copper sleeve 56.

[0040] Furthermore, the pressure head mounting base 5 also includes a piezoelectric ceramic crystal stack 57, which is sleeved on the outer periphery of the mandrel 55 and disposed between the mandrel 55 and the oxygen-free copper sleeve 56. The piezoelectric ceramic crystal stack 57 is electrically connected to an external bonding device.

[0041] The mandrel contains a piezoelectric ceramic crystal stack 57, which, together with an external charge amplification circuit, can achieve an ultra-high force measurement resolution of 0.1mN. It can capture the instantaneous force change at the moment of contact, allowing the control system to respond within microseconds and precisely control the bonding force within a safe range.

[0042] Furthermore, the pressure head mounting base 5 also includes a zirconia pad 58, which is sleeved on the outer periphery of the piezoelectric ceramic crystal stack 57; both the piezoelectric ceramic crystal stack 57 and the zirconia pad 58 are disposed between the mandrel 55 and the oxygen-free copper sleeve 56, with the zirconia pad 58 located below the piezoelectric ceramic crystal stack 57; the thickness of the zirconia pad 58 is 2-3 mm.

[0043] To minimize thermal interference from the bottom layer, a zirconia pad 58 is placed between the force measuring mandrel and the bottom layer for isolation. The zirconia pad 58, with a thickness of 2–3 mm, is coaxially nested to achieve both compressive strength and physical isolation. This gives the flip-bonded coaxial decoupling adaptive pressure head mechanism high rigidity and high-temperature resistance, enabling effective force closed-loop control.

[0044] Specifically, the rubber elastomer 6 includes a material box 61 and an elastomer body 62. The material box 61 has an elastomer mounting port in the middle. The elastomer body 62 is disposed at the elastomer mounting port, and the top surface of the elastomer body 62 is in close contact with the bottom of the mounting cavity. The material box 61 is detachably installed in the mounting cavity.

[0045] Perfluoroelastomer rubber will undergo permanent deformation after long-term use and is a consumable. The above structure can be used to quickly replace the aged perfluoroelastomer rubber body.

[0046] Furthermore, the inner wall of the mounting cavity is provided with two spring holes, which are arranged opposite to each other; a spring ball plunger 9 is provided in the spring hole, and the outer wall of the material box 61 is provided with a clearance groove that matches the number and position of the spring ball plunger 9; the material box 61 and the pressure head mounting seat 5 are detachably connected through the spring ball plunger 9 and the clearance groove.

[0047] The structure of the spring ball plunger 9 can refer to the existing spring plunger. The spring plunger includes a housing, a spring and a ball plunger. The spring ball plunger 9 is installed in the spring hole through the external thread of the housing. The spring is installed inside the housing, and one end of the spring is connected to the bottom of the cavity of the housing, and the other end of the spring is connected to the ball plunger. The spring pushes the spring plunger out of the opening of the housing.

[0048] In one specific embodiment of the present invention, the elastomer body 62 is disposed in the material box 61, which allows for quick and complete replacement. The size of the material box 61 is adapted to the mounting cavity, allowing it to be embedded within the cavity and clamped and fixed by spring ball plungers 9 disposed on the inner wall of the mounting cavity. The material box 61 is clamped by the preload of the spring ball plungers 9 on both sides. Since the outer wall of the material box 61 has a clearance groove, the spring ball plungers 9 can rest in the clearance groove. When disassembly is required, it can be pulled out by force using a clamp. The relative position of the spring ball plungers 9 and the clearance groove changes, and the spring in the spring ball plungers 9 is compressed, causing the ball plungers of the spring ball plungers 9 to disengage from the groove, thereby allowing the material box 61 to be removed.

[0049] Furthermore, the bottom surface of the elastomer body 62 is provided with a paraben conformal coating 63, the thickness of which is 5 to 15 micrometers.

[0050] In a specific embodiment of the present invention, a room temperature vacuum chemical vapor deposition (CVD) process is used to grow a 5-15 μm thick high-temperature phenelzine conformal coating containing a perfluorinated aliphatic chain structure on the elastomer body 62.

[0051] The Pirilin conformal coating 63 can withstand high temperatures of 350°C without melting, has a Young's modulus of 2-3 GPa, and combines flexibility with anti-adhesion, high chemical stability, and no organic matter release characteristics. Moreover, it can achieve non-destructive deformation with the hyperelastic conformal pressure uniform pressure of the elastomer body 62, and fit the warped wafer surface.

[0052] By using non-magnetic components and fasteners, along with the Parylene conformal coating 63, electromagnetic interference and organic contamination sources are minimized, thereby improving the yield rate of highly sensitive devices such as chips.

[0053] Specifically, the depth of the mounting cavity is 0.7 to 1.0 mm, the bottom of the material box 61 is flush with the edge of the mounting cavity, and the elastomer body 62 protrudes 0.01 to 0.02 mm from the edge of the mounting cavity.

[0054] The elastomer body 62 is made of perfluoroether rubber, and the thickness of the elastomer body 62 is slightly convex to the mounting cavity of 0.01 to 0.02 mm. The total metal ion content of the perfluoroether rubber is controlled below 5 ppm, which is a high-purity perfluoroether rubber. When subjected to bonding pressure, the elastomer body 62 is volume-locked by the circumferential rigid sidewalls, generating a hyperelastic conformal uniform pressure across the entire surface.

[0055] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A coaxial decoupling adaptive pressure head mechanism for inverted bonding, characterized in that, This includes quick-change flange joints, micro-deformation force connectors, floating frames, flexible hinges, pressure head mounting bases, and rubber elastomers; The quick-change flange joint is connected to the floating frame via a micro-deformation force connector; the floating frame has a receiving cavity, the flexible hinge is disposed in the receiving cavity, and the pressure head mounting seat is rotatably assembled to the bottom of the flexible hinge; The pressure head mounting base has an air cavity inside, and one side of the pressure head mounting base has an interface communicating with the air cavity; the top surface of the pressure head mounting base has an air outlet communicating with the air cavity; the bottom of the pressure head mounting base has an installation cavity, and the bottom of the installation cavity has multiple micropores communicating with the air cavity; the rubber elastomer is disposed in the installation cavity.

2. The coaxial decoupling adaptive pressure head mechanism for inverted bonding according to claim 1, characterized in that, The micro-deformation force connector includes several spring plates, each spring plate having an arc-shaped cross-section; the several spring plates are distributed circumferentially along the floating frame, one end of each spring plate is connected to a quick-change flange joint, and the other end of each spring plate is connected to the floating frame.

3. The coaxial decoupling adaptive pressure head mechanism for inverted bonding according to claim 1, characterized in that, The flexible hinge includes a hinge body, a first hinge arm unit, and a second hinge arm unit. The first hinge arm unit is located above the second hinge arm unit. Both the first and second hinge arm units include several hinge arms. One end of each hinge arm is connected to the side wall of the hinge body, and the other end of each hinge arm is connected to the inner wall of the accommodating cavity.

4. The coaxial decoupling adaptive pressure head mechanism for inverted bonding according to claim 3, characterized in that, The pressure head mounting base is provided with a mandrel and an oxygen-free copper sleeve. The hinge body is provided with a pivot mounting groove. The upper end of the mandrel is detachably connected to the pivot mounting groove, and the lower end of the mandrel is fixedly connected to the pressure head base. The oxygen-free copper sleeve is sleeved on the outer circumference of the mandrel and embedded in the pivot mounting groove.

5. A coaxial decoupling adaptive pressure head mechanism for inverted bonding according to claim 3, characterized in that, The pressure head mounting base also includes a piezoelectric ceramic crystal stack, which is sleeved on the outer periphery of the mandrel and disposed between the mandrel and the oxygen-free copper sleeve. The piezoelectric ceramic crystal stack is electrically connected to an external bonding device.

6. The coaxial decoupling adaptive pressure head mechanism for inverted bonding according to claim 5, characterized in that, The pressure head mounting base also includes a zirconia pad, which is sleeved on the outer periphery of the piezoelectric ceramic crystal stack; both the piezoelectric ceramic crystal stack and the zirconia pad are disposed between the mandrel and the oxygen-free copper sleeve, with the zirconia pad located below the piezoelectric ceramic crystal stack; the thickness of the zirconia pad is 2-3 mm.

7. A coaxial decoupling adaptive pressure head mechanism for inverted bonding according to claim 1, characterized in that, The rubber elastomer includes a material box and an elastomer body. The material box has an elastomer mounting port in the middle. The elastomer body is disposed in the elastomer mounting port, and the top surface of the elastomer body is in close contact with the bottom of the mounting cavity. The material box is detachably installed in the mounting cavity.

8. A coaxial decoupling adaptive pressure head mechanism for inverted bonding according to claim 7, characterized in that, The inner wall of the mounting cavity is provided with two spring holes, which are arranged opposite to each other; a spring ball plunger is provided in the spring hole, and the outer wall of the material box is provided with a clearance groove that matches the number and position of the spring ball plunger; the material box and the pressure head mounting seat are detachably connected through the spring ball plunger and the clearance groove.

9. A coaxial decoupling adaptive pressure head mechanism for inverted bonding according to claim 7, characterized in that, The bottom surface of the elastomer body is provided with a phenelzine conformal coating, the thickness of which is 5 to 15 micrometers.

10. A coaxial decoupling adaptive pressure head mechanism for inverted bonding according to claim 7, characterized in that, The depth of the mounting cavity is 0.7 to 1.0 mm, the bottom of the material box is flush with the edge of the mounting cavity, and the elastomer body protrudes 0.01 to 0.02 mm from the edge of the mounting cavity.

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