Bonding device

Abstract

The invention relates to the technical field of semiconductor packaging equipment, in particular to a bonding device which comprises a box body, a Z-direction driving assembly, a T-direction motor, a T-direction band-type brake mechanism, an air bearing assembly, a main air bearing, a mechanical guide rail assembly, an air spring, a suction nozzle rod and a suction nozzle. The Z-direction driving assembly comprises a voice coil motor, a Z-direction connecting seat and a grating ruler assembly, the lower end of the voice coil motor is connected with the Z-direction connecting seat, and the grating ruler assembly is arranged on the Z-direction connecting seat; the T-direction motor is arranged on the Z-direction connecting seat, and the lower end of the T-direction motor is connected with the gas spring; the T-direction band-type brake mechanism blows air outwards, so that an air film is formed between the T-direction band-type brake mechanism and the air spring upper flange; the air bearing assemblies are arranged on the two sides of the Z-direction connecting base. The main air bearing is arranged on the suction nozzle rod; the mechanical guide rail assembly is arranged at the rear end of the Z-direction connecting seat; the suction nozzle rod is connected with the air spring, the suction nozzle is arranged at the lower end of the suction nozzle rod, mechanical guide rail guiding and air bearing guiding decoupling are adopted, and the bonding precision is improved.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor packaging equipment and particularly to a bonding device. Background Art

[0002] The bonding head is a key component for high-precision placement and bonding of components such as chips. Through the handover of complex mechanisms and the use of vacuum adsorption of chips, the chip can be accurately placed from the wafer to the target object to achieve the circuit interconnection function of the chip. In the process of chip placement, the bonding head needs to strictly control the rotation angle and positioning accuracy in the XY direction. Only by strictly controlling the accuracy in each direction can high-precision placement be achieved. At the same time, the bonding head also needs to provide precise pressure control to prevent pressure fluctuations from damaging the chip.

[0003] Due to the design of the equipment architecture, the bonding head of the prior art is generally designed as a cantilever mechanism. This design has a great impact on the dynamic performance of the bonding head, and it is difficult to achieve sub-micron level mounting accuracy. At the same time, due to the cantilever setting, the load on the running guide rail is large, which reduces the service life of the guide rail. The Z-direction motion guide of the bonding head of the prior art is mostly a mechanical guide rail or a ball bushing structure, which leads to a certain friction during the movement process, which will have a great impact on the precise pressure control; at the same time, the movement repeatability of the mechanical guide rail is difficult to control to less than 100nm, so it is difficult to achieve the sub-micron level mounting accuracy of the bonding head. According to the use requirements of the bonding head, a vacuum adsorption air pipe needs to be provided. Due to the limitation of the rotating mechanism in the prior art, the bonding head cannot achieve both 360° rotation and a large Z-direction motion stroke. The existing T-direction rotation mechanism of the bonding head is generally driven by a servo motor, but due to the characteristics of the servo motor itself, the motor has 2 to 3 small fluctuations during the control process, which will cause a large top angle deflection error when mounting large chips, and cannot achieve high-precision mounting requirements. Summary of the invention

[0004] The present invention provides a bonding device to solve the problems in the prior art.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A bonding device, comprising: a box, a Z-direction drive assembly, a constant force spring assembly, a T-direction motor, a brake assembly, an air bearing assembly, a main air bearing, a mechanical guide rail assembly, a gas spring, a nozzle rod and a nozzle; The box body includes a bonding head shell, a shell mounting seat is provided on the box body, one end of the shell mounting seat is connected to a driving mechanism, and the bonding head device is driven to move horizontally by the driving mechanism, and a reading head is provided on the box body; the Z-axis driving assembly includes a voice coil motor, a Z-axis connecting seat and a grating ruler assembly, the voice coil motor is fixed in the box body and the lower end is connected to the Z-axis connecting seat, the Z-axis connecting seat is driven to move by the voice coil motor, and the grating ruler assembly is arranged on the Z-axis connecting seat; the constant force spring assembly is arranged on both sides of the Z-axis connecting seat, and the weight of the Z-axis driving assembly is balanced by the constant force spring assembly; the T-axis motor is arranged on the Z-axis connecting seat, the lower end of the T-axis motor is connected to a gas spring, and the upper end of the gas spring is connected to the gas spring upper flange; the brake assembly The components include an X-direction brake 1, an X-direction brake 2 and a T-direction brake mechanism, wherein the X-direction brake 1 and the X-direction brake 2 are arranged on both sides of the box body, and the T-direction brake mechanism is connected with a T-direction brake joint, through which a vacuum or atmosphere is introduced into the inside of the T-direction brake mechanism, and the T-direction brake mechanism blows air outward to form an air film between the T-direction brake mechanism and the upper flange of the gas spring, allowing the T-direction motor to rotate freely; the air-floating bearing assembly is arranged on both sides of the Z-direction connecting seat, and the air-floating bearing assembly provides air-floating gas to enable the T-direction brake mechanism to move frictionlessly in the Z direction; the main air-floating bearing is arranged on the nozzle rod; the mechanical guide rail assembly is arranged at the rear end of the Z-direction connecting seat; the nozzle rod is connected to the gas spring, and the nozzle is arranged at the lower end of the nozzle rod.

[0006] A further improvement is that the air bearing assembly also includes air bearing 1, air bearing 2, guide rod 1, guide rod 2, ball joint 1, ball joint 2, a main air bearing and a main air bearing joint connected to the main air bearing, a chip air path joint and a nozzle air path joint; a rotation stop seat is provided at the lower end of the Z-axis connecting seat; the air bearing 1 and the air bearing 2 are interference fit and symmetrically arranged inside the rotation stop seat; an air bearing 1 joint is provided on the air bearing 1, and an air bearing 2 joint is provided on the air bearing 2; the guide rod 1 and the guide rod 2 are respectively passed through the air bearing 1 and the air bearing 2, and the ball joint 1 and the ball joint 2 are respectively arranged at the lower ends of the guide rod 1 and the guide rod 2.

[0007] A further improvement is that the constant force spring assembly includes a constant force spring bracket one, a constant force spring bracket two, a constant force spring one and a constant force spring two, the constant force spring bracket one and the constant force spring bracket two are symmetrically fixed on the Z-direction connecting seat, the constant force spring one and the constant force spring two are symmetrically mounted inside the constant force spring bracket one and the constant force spring bracket two, and the upper ends of the constant force spring one and the constant force spring two are locked on the bonding head shell.

[0008] As a further improvement, T-direction brake return spring 1 and T-direction brake return spring 2 are symmetrically installed at the lower end of the T-direction brake mechanism; a T-direction brake mechanism throttle hole and a V-shaped T-direction brake mechanism air path groove are distributed on the upper surface of the T-direction brake mechanism, and there are interconnected cavities inside the T-direction brake mechanism and the lower surface is sealed by a sealing member.

[0009] A further improvement is that a Z-direction fixing seat 1 and a Z-direction fixing seat 2 are symmetrically connected to the inner side of the bonding head shell, and the lower ends of the Z-direction fixing seat 1 and the Z-direction fixing seat 2 are connected to a Z-direction fixing plate, and the lower end surface of the Z-direction fixing plate is fixedly connected to piezoelectric ceramic 1, piezoelectric ceramic 2 and piezoelectric ceramic 3, the upper end surfaces of the piezoelectric ceramic 1, piezoelectric ceramic 2 and piezoelectric ceramic 3 are all planes and the lower end surfaces are all spherical, the lower ends of the piezoelectric ceramic 1, piezoelectric ceramic 2 and piezoelectric ceramic 3 are supported and arranged on the upper surface of the main air floating sleeve, and the piezoelectric ceramic 1, piezoelectric ceramic 2 and piezoelectric ceramic 3 are arranged in an isosceles triangle, and high-elastic tension springs for pre-tightening the piezoelectric ceramic 1, piezoelectric ceramic 2 and piezoelectric ceramic 3 are symmetrically arranged on both sides of the Z-direction fixing plate and the main air floating sleeve, and the left and right sides of the main air floating sleeve are connected with a small leaf spring and a small leaf spring 2 through a pressure block 3.

[0010] As a further improvement, a gas spring fixing column is provided inside the gas spring, a height adjustment column is provided on the gas spring fixing column, a positioning step is provided at the lower end of the height adjustment column, a flexible hinge is provided on the inner circle of the upper flange of the gas spring, and a height gap is provided between the flexible hinge and the height adjustment column.

[0011] A further improvement is that a Z-axis motion plate is provided on the mechanical guide rail assembly, a safety position sensor is provided on the inner side of the bonding head housing, a light shield is slidably provided on the Z-axis motion plate, and the light shield can block the safety position sensor when it moves; a Z-axis limit block is provided inside the bonding head housing, and the Z-axis limit block is located on one side of the Z-axis motion plate; the grating scale assembly includes a grating scale mounting seat and a grating scale, the grating scale mounting seat is arranged on the Z-axis connecting seat, and the grating scale is arranged on the grating scale mounting seat.

[0012] A further improvement is that the box body is provided with a reading head mounting seat, the reading head is arranged on the reading head mounting seat, the box body is also provided with an eddy current sensor support and an eccentric pin fixing seat, the eccentric pin is installed on the eccentric pin fixing seat by locking with a top screw, the position of the eddy current sensor support is adjusted by rotating the eccentric pin, and the eddy current sensor is clamped on the eddy current sensor support.

[0013] As a further improvement, the box body is also connected to an exhaust connector 1 and an exhaust connector 2, a large leaf spring is provided at the bottom of the bonding head shell, pressure blocks 1 and 2 are provided on the outside of the large leaf spring, and exhaust gap 1 and exhaust gap 2 are provided on the bottom of the box body, which cooperate with exhaust connector 1 and exhaust connector 2 to form a circulating airflow from bottom to top, and exhaust gap 1 and exhaust gap 2 are located on both sides of the large leaf spring.

[0014] As a further improvement, the brake assembly also includes a T-direction motor fixing flange and a T-direction motor rotating flange, the T-direction motor is connected to the Z-direction connecting seat via the T-direction motor fixing flange, the T-direction motor rotating flange is arranged at the lower end of the T-direction motor, and the gas spring upper flange at the upper end of the gas spring is connected to the T-direction motor rotating flange; a T-direction motor connector is provided at the hollow shaft end at the upper end of the T-direction motor, and the T-direction motor connector is connected to an electromagnetic proportional valve, which controls the compressed gas to pass through the T-direction motor into the interior of the gas spring.

[0015] Compared with the prior art, the bonding device of the present invention has the following beneficial effects: The bonding device provided by the present invention adopts a symmetrical structural design and is supported at both ends, thereby avoiding a cantilever structure, and can effectively improve the dynamic performance and thermal stability of the mechanism; a scheme of decoupling the mechanical guide rail guidance and the air bearing guidance is adopted to reduce the influence of the repeated random errors of the mechanical guide rail on the patch accuracy; the rotation positioning mechanism adopted by the bonding head of the present invention can realize Z-direction movement with a large stroke, and can also realize 360-degree rotation of the nozzle rod; the brake mechanism of the present invention includes an X-direction brake and a T-direction brake, and the X-direction brake 1 and the X-direction brake 2 realize the X-direction brake, which can reduce the horizontal jitter of the entire mechanism during bonding, and the T-direction brake mechanism adopts an air bearing brake, which can reduce the rotation jitter during bonding, and can greatly improve the bonding accuracy to reach the sub-micron level. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the overall appearance diagram of the present invention; Figure 2 It is the front view of the present invention; Figure 3 It is a rear side view of the present invention; Figure 4 It is a bottom view of the present invention; Figure 5 This is an internal view of the present invention; Figure 6 It is a front view of the internal structure of the present invention; Figure 7 It is a rear view of the internal structure of the present invention; Figure 8 It is a schematic diagram of the T-direction brake mechanism in the present invention; Fig. 9 It is a schematic diagram of the T-direction brake mechanism in the present invention from another perspective; Fig.10 It is a rear view of the internal structure of the gas spring in the present invention; Fig.11 This is a schematic diagram of the nozzle clamping in the present invention; In the figure, 1-bonding head housing, 2-housing cover plate, 3-housing mounting seat, 4-exhaust joint 1, 5-exhaust joint 2, 6-reading head mounting seat, 7-reading head, 8-eddy current sensor support, 9-eccentric pin, 10-eccentric pin fixing seat, 11-X-axis brake 1, 12-X-axis brake 2, 13-suction nozzle rod, 1301-suction nozzle airway, 1302-chip airway, 14-suction nozzle, 15-large leaf spring, 16-pressing block 1, 17-pressing block 2, 18-exhaust gap 1, 19-exhaust gap 2, 20 - Voice coil motor, 21- Constant force spring bracket 1, 22- Constant force spring bracket 2, 23- Constant force spring 1, 24- Constant force spring 2, 25- Safety position sensor, 26- Light shield, 27- Guide rod 1, 28- Guide rod 2, 29- Air bearing 1, 30- Air bearing 2, 31- Air bearing 1 connector, 32- Air bearing 2 connector, 33- T-axis motor, 34- Rotary stop seat, 35- Eddy current sensor, 36- Small leaf spring 1, 37- Small leaf spring 2, 38- Pressure block 3, 39- Z-axis limit block, 40-Z-axis connecting seat, 41-T-axis motor connector, 42-grating ruler mounting seat, 43-grating ruler, 44-gas spring, 4401-gas spring upper flange, 4402-gas spring fixing column, 45-Z-axis fixing seat 1, 46-Z-axis fixing seat 2, 47-Z-axis fixing plate, 48-preload spring 1, 49-preload spring 2, 50-piezoelectric ceramic 1, 51-piezoelectric ceramic 2, 52-main air floating shaft sleeve, 53-main air floating bearing, 54-main air floating bearing connector, 55-chip gas circuit connector, 56-nozzle air Road joint, 57-Z-axis motion plate, 58-mechanical guide rail one, 59-mechanical guide rail two, 60-piezoelectric ceramic three, 61-ball joint one, 62-ball joint two, 63-T-axis motor fixing flange, 64-T-axis motor rotating flange, 65-T-axis brake joint, 66-T-axis brake return spring one, 67-T-axis brake return spring two, 68-T-axis brake mechanism, 6801-T-axis brake mechanism throttle hole, 6802-T-axis brake mechanism air path groove, 69-flexible hinge, 70-height adjustment column, 71-height gap. DETAILED DESCRIPTION

[0017] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] Below is a combination of the embodiments and the attached Figure 1 to Figure 11 , the technical solution of the present invention is further elaborated.

[0019] Embodiment 1: A bonding device, comprising: a housing, a Z-direction drive assembly, a constant force spring assembly, a T-direction motor 33, a brake assembly, an air bearing assembly, a main air bearing 53, a mechanical guide assembly, a gas spring 44 (a frictionless homemade gas spring, different gas pressures can correspond to different output pressures), a nozzle rod 13 and a nozzle 14; The box body comprises a bonding head housing 1, a housing mounting seat 3 is provided on the box body, one end of the housing mounting seat 3 is connected to a driving mechanism (not shown in the figure), and the driving mechanism drives the bonding head device to move horizontally to realize the chip transportation function, and a reading head 7 is provided on the box body; The Z-axis driving assembly includes a voice coil motor 20, a Z-axis connecting seat 40, a grating ruler assembly and a reading head 7. The voice coil motor 20 is fixed in the box 1 and the lower end is connected to the Z-axis connecting seat 40. The Z-axis connecting seat 40 is driven to move by the voice coil motor 20. The entire Z-axis driving assembly can be driven to move by pushing the Z-axis connecting seat 40. The grating ruler assembly is arranged on the Z-axis connecting seat 40. The voice coil motor 20 cooperates with the grating ruler assembly and the reading head 7 to achieve precise Z-axis position control. The grating ruler assembly includes a grating ruler mounting seat 42 and a grating ruler 43. The grating ruler mounting seat 42 is arranged on the Z-axis connecting seat 40, and the grating ruler 43 is arranged on the grating ruler mounting seat 42. The constant force spring assembly is arranged on both sides of the Z-direction connecting seat 40, and the weight of the Z-direction driving assembly is balanced by the constant force spring assembly; The T-direction motor 33 is disposed on the Z-direction connection seat 40, the lower end of the T-direction motor 33 is connected to a gas spring 44, and the upper end of the gas spring 44 is connected to a gas spring upper flange 4401; The brake assembly includes an X-direction brake 11, an X-direction brake 2 12 and a T-direction brake mechanism 68, wherein the X-direction brake 11 and the X-direction brake 2 12 are arranged on both sides of the box body, and after the bonding head moves horizontally into place and the X-direction brake 11 and the X-direction brake 2 12 are locked and maintain a high stability state, the nozzle rod 13 can move in the Z direction to achieve chip bonding and picking, and the X-direction brake 11 and the X-direction brake 2 12 ensure that the bonding head is locked after moving horizontally into place, so that the bonding head box body is in a completely locked rigid body state when bonding, reducing the interference of motor jitter and guide rail stiffness on bonding accuracy; The T-direction brake mechanism 68 is connected to a T-direction brake connector 65, through which a vacuum or atmosphere is introduced into the interior of the T-direction brake mechanism 68. The T-direction brake mechanism 68 blows air outward to form an air film between the T-direction brake mechanism 68 and the upper flange 4401 of the gas spring, allowing the T-direction motor 33 to rotate freely 360 degrees. When the T-direction motor 33 rotates into place and needs to be locked, the T-direction brake mechanism 68 starts to draw a vacuum, so that the T-direction brake mechanism 68 and the upper flange 4401 of the gas spring fit tightly. The T-direction motor 33 selected in the present invention is a hollow motor, and gas can pass through its interior.

[0020] The air bearing assembly is arranged on both sides of the Z-direction connection seat 40. The air bearing forms an air film through high-pressure gas to support the shaft rod, thereby achieving frictionless guidance and support, which is convenient for improving the running accuracy of the shaft rod. The air bearing assembly provides air floating gas to enable the T-direction brake mechanism 68 to move frictionlessly in the Z direction. The main air bearing 53 is arranged on the nozzle rod 13. The mechanical guide rail assembly is arranged at the rear end of the Z-direction connection seat 40, and the Z-direction connection seat 40 is connected to the mechanical guide rail assembly through the Z-direction motion plate 57. The mechanical guide rail assembly includes a mechanical guide rail 1 58 and a mechanical guide rail 2 59, and the mechanical guide rail 1 58 and the mechanical guide rail 2 59 are installed inside the bonding head housing 1. The back of the Z-direction motion plate 57 is installed on the sliders of the mechanical guide rail 1 58 and the mechanical guide rail 2 59, and the front of the Z-direction motion plate 57 is connected to the Z-direction connection seat 40; The nozzle rod 13 is connected to the gas spring 44, and the nozzle 14 is arranged at the lower end of the nozzle rod 13. The gas spring 44 and the nozzle rod 13 can realize both Z-direction movement and T-direction rotation through the T-direction motor 33.

[0021] The brake mechanism of a traditional motor has a large gap, and the brake function is limited to preventing falling in the Z direction, without any accuracy. The brake assembly of the present invention includes an X-direction brake 11, an X-direction brake 2 12 and a T-direction brake mechanism 68. The X-direction brake 11 and the X-direction brake 2 12 realize the X-direction brake, which can reduce the horizontal jitter of the entire mechanism during bonding. The T-direction brake mechanism 68 adopts an air-floating brake, which can reduce the rotational jitter during bonding and greatly improve the bonding accuracy.

[0022] The Z-axis mechanism of the bonding head must be supported by a guiding mechanism when it moves. At the same time, in order to reduce the random errors introduced by the repetitive movement of the traditional mechanical guide rail, it is considered to use an air bearing (frictionless) as a guiding mechanism. However, since the Z-axis motion mechanism is relatively heavy, a simple air bearing is not enough to provide sufficient support; therefore, the present invention provides a special guiding method, that is, a supporting guiding mechanism used in combination with a mechanical guide rail + an air bearing. The Z-axis motion guides of the heavier parts such as the Z-axis drive assembly of the bonding head, the T-axis motor 33, and the T-axis brake mechanism 68 are supported by mechanical guide rails 1 58 and 2 59, and the lighter nozzle rod 13 is supported by the main air bearing 53. The upper end of the gas spring 44 is connected to the heavy moving part, and the lower end is connected to the nozzle rod 13. At the same time, the gas spring 44 is connected to the main air bearing 53. The flexible characteristic of the gas spring 44 is used to decouple the over-constrained installation of the mechanical guide rail and the air bearing, that is, the motion error of the mechanical guide rail is absorbed by the deformation of the gas spring 44 and will not be transmitted to the air bearing, thereby ensuring both motion support and accuracy during end bonding. The air bearing assembly can effectively reduce tiny mechanical errors while avoiding over-constrained design, ensuring nanometer-level anti-rotation function, combining the advantages and disadvantages of the guide mechanism, having good dynamic performance, providing sub-micron bonding accuracy, and increasing service life, and can be widely used in advanced packaging patch, flip-chip and other equipment.

[0023] Due to the characteristics of the servo motor itself, the motor has 2 to 3 small fluctuations during the control process, which will cause a large vertex angle deflection error when mounting a large chip. As a further preferred embodiment, in order to achieve frictionless movement in the Z direction and high-precision repetitive movement, the air bearing assembly also includes an air bearing 1 29, an air bearing 2 30, a guide rod 1 27, a guide rod 28, a ball joint 1 61, a ball joint 2 62, a main air bearing 53 and a main air bearing joint 54 connected to the main air bearing 53, a chip air path joint 55 and a nozzle air path joint 56; the main air bearing joint 54, the chip air path joint 55 and the nozzle air path joint 56 can provide three independent air supplies. The main air bearing joint 54 provides positive pressure gas to form an air film with the nozzle rod 13, which can ensure that the nozzle rod 13 is not affected by external friction when rotating in the T direction and moving in the Z direction, thereby providing a more precise repetitive movement. The chip air circuit connector 55 cooperates with the electromagnetic valve to provide vacuum or positive pressure gas, which is finally transmitted to the inside of the suction nozzle rod 13. The suction nozzle air circuit connector 56 cooperates with the electromagnetic valve to provide vacuum or positive pressure gas, which is finally transmitted to the inside of the suction nozzle rod 13. The lower end of the Z-axis connecting seat 40 is provided with a rotating stop seat 34, and the air bearing 1 29 and the air bearing 2 30 are interference fit and symmetrically arranged inside the rotating stop seat 34; the air bearing 1 29 is provided with an air bearing 1 connector 31, and the air bearing 2 30 is provided with an air bearing 2 connector 32 for providing air bearing gas; the guide rod 1 27 and the guide rod 2 28 are respectively passed through the air bearing 1 29 and the air bearing 2 30, and can perform frictionless movement in the Z direction. The ball joint 1 61 and the ball joint 2 62 are respectively arranged at the lower ends of the guide rod 1 27 and the guide rod 2 28, and at the same time, the ball joint 1 61 and the ball joint 2 62 ensure that the T-axis brake mechanism 68 performs Z-axis movement, but cannot perform T-axis rotation. The ball joint and air bearing are used together to further reduce tiny mechanical errors while avoiding over-constrained design, ensuring nanometer-level anti-rotation function.

[0024] As a further preferred embodiment, in order to improve the stability of the movement of the Z-direction drive assembly and the stability of the movement of the bonding head, the constant force spring assembly includes a constant force spring bracket 1 21, a constant force spring bracket 22, a constant force spring 1 23 and a constant force spring 24, the constant force spring bracket 1 21 and the constant force spring bracket 2 22 are symmetrically fixed on the Z-direction connecting seat 40, the constant force spring 1 23 and the constant force spring 2 24 are respectively symmetrically mounted inside the constant force spring bracket 1 21 and the constant force spring bracket 2 22, and are locked therein, and the upper ends of the constant force spring 1 23 and the constant force spring 2 24 are locked on the bonding head housing 1. The function of the constant force spring is mainly to balance the weight of the Z-direction motion mechanism to ensure that the entire Z-direction drive assembly will not fall when the motor is unenabled or damaged, and the force of the constant force spring is constant, which can balance the gravity and will not change according to the elastic force after the movement of the Z-direction drive assembly. It is superior to ordinary springs (tension springs or compression springs). Ordinary springs gradually change their elastic force as the movement displacement changes, which will bring additional additional force.

[0025] As a further preferred embodiment, in order to improve the tightness of the upward movement of the T-direction brake mechanism 68 and the contact with the upper flange 4401 of the gas spring, the lower end of the T-direction brake mechanism 68 is symmetrically installed with T-direction brake return spring 1 66 and T-direction brake return spring 2 67, and the T-direction brake return spring 1 66 and T-direction brake return spring 2 67 assist in pushing the T-direction brake mechanism 68 to move upward and contact the upper flange 4401 of the gas spring; the upper surface of the T-direction brake mechanism 68 is distributed with a T-direction brake mechanism throttle hole 6801 and a V-shaped T-direction brake mechanism air path groove 6802, and the T-direction brake mechanism 68 has an interconnected cavity inside and the lower surface is sealed by a sealing member. When positive pressure gas is passed through the T-direction brake joint 65, gas is discharged through the T-direction brake mechanism throttle hole 6801 and the T-direction brake mechanism gas path groove 6802, forming an air-floating air film on the upper surface of the T-direction brake mechanism 68 and the gas spring upper flange 4401, and the gas spring 44 can rotate freely. When vacuum gas is passed through the T-direction brake joint 65, a vacuum negative pressure cavity is formed through the T-direction brake mechanism throttle hole 6801 and the T-direction brake mechanism gas path groove 6802, so that the T-direction brake mechanism 68 is tightly adsorbed to the gas spring upper flange 4401, and the gas spring 44 cannot rotate freely.

[0026] As a further preferred embodiment, in order to improve the leveling accuracy of the overall mechanism, the inner side of the bonding head housing 1 is symmetrically connected with a Z-direction fixing seat 1 45 and a Z-direction fixing seat 2 46, the lower ends of the Z-direction fixing seat 1 45 and the Z-direction fixing seat 2 46 are connected with a Z-direction fixing plate 47, the lower end surface of the Z-direction fixing plate 47 is fixedly connected with a piezoelectric ceramic 1 50, a piezoelectric ceramic 2 51 and a piezoelectric ceramic 3 60, the upper end surfaces of the piezoelectric ceramic 1 50, the piezoelectric ceramic 2 51 and the piezoelectric ceramic 3 60 are all planes and the lower end surfaces are all spherical, the lower ends of the piezoelectric ceramic 1 50, the piezoelectric ceramic 2 51 and the piezoelectric ceramic 3 60 are supported and arranged on the upper surface of the main air-floating sleeve 52, and the piezoelectric ceramic 1 50, the piezoelectric ceramic 2 51 and the piezoelectric ceramic 3 60 are The piezoelectric ceramics 3 and 60 are arranged in an isosceles triangle. High-elastic tension springs for pre-tightening the piezoelectric ceramics 1 50, the piezoelectric ceramics 2 51 and the piezoelectric ceramics 3 60 are symmetrically arranged on both sides of the Z-direction fixed plate 47 and the main air-floating sleeve 52. The high-elastic tension springs are used to pre-tighten the piezoelectric ceramics so that the three piezoelectric ceramics are always in close contact with the Z-direction fixed plate 47 and the main air-floating sleeve 52; the left and right sides of the main air-floating sleeve 52 are connected with small leaf springs 1 36 and small leaf springs 2 37 through pressure blocks 3 38 (a leaf spring is a structure that can provide support and have a certain amount of deformation in a certain direction, which can reduce over-constraint in the design). Using pressure blocks 3 38 for installation can increase the contact area of ​​the leaf springs, thereby providing better stiffness support. The main air-floating sleeve 52 is installed in the bonding head housing through a large leaf spring 15, a small leaf spring 1 36 and a small leaf spring 2 37. It has good constraints and rigidity in the horizontal direction, but has a certain degree of freedom in the Z direction due to the flexibility of the leaf spring. With the three piezoelectric ceramics, the main air-floating bearing 53 can be leveled, thereby leveling the suction nozzle 14 to meet the angle requirements during chip bonding. At the same time, when the module is assembled, the bonding head mechanism will also place high-precision leveling gaskets at different positions on the lower surface of the shell mounting seat 3 to pre-level the entire mechanism. Therefore, the bonding head mechanism has two leveling functions: manual leveling and automatic leveling, which can meet the requirements of high-precision leveling.

[0027] As a further preferred embodiment, in order to improve the safety of the bonding head during high-speed movement, a Z-axis motion plate 57 is provided on the mechanical guide rail assembly, a safety position sensor 25 is provided on the inner side of the bonding head housing 1, and a light blocking plate 26 is slidably provided on the Z-axis motion plate 57. The light blocking plate 26 can block the safety position sensor 25 when it moves. When the light blocking plate 26 blocks the safety position sensor 25, a signal is output, indicating that the bonding head mechanism can move horizontally at this time, which can effectively avoid the bonding head from colliding during high-speed movement; a Z-axis limit block 39 is provided inside the bonding head housing 1, and the Z-axis limit block 39 is located on one side of the Z-axis motion plate 57, which is used as a mechanical limit of the Z-axis motion mechanism to ensure that the Z-axis drive assembly operates within a safe range.

[0028] As a further preferred embodiment, in order to more accurately obtain the Z-direction position of the bonding head, a reading head mounting seat 6 is provided on the box body, and the reading head 7 is arranged on the reading head mounting seat 6. The reading head 7 can read the signal and accurately obtain the Z-direction position of the bonding head; the box body is also provided with an eddy current sensor support 8 and an eccentric pin fixing seat 10, and an eccentric pin 9 is installed on the eccentric pin fixing seat 10 by locking with a top screw. The position of the eddy current sensor support 8 is adjusted by rotating the eccentric pin 9. The eddy current sensor support 8 is clamped with an eddy current sensor 35, which is convenient for adjusting the eddy current sensor 35 to the optimal distance and detecting the best signal; when the gas spring 44 moves downward, the eddy current sensor 35 can detect different displacement distances of the lower surface of the gas spring 44. The eddy current sensor has a high-precision and high-resolution signal feedback function. The eddy current sensor 35 can feedback different signals, so that the Z-direction position of the nozzle rod 13, that is, the Z-direction position of the bonding head, can be obtained, the movement position can be monitored in real time, and the chip can be protected from damage. The eddy current sensor 35 can provide a distance detection function, and can also monitor the Z-axis position of the nozzle rod 13 in real time, and promptly alarm when height abnormalities occur during bonding (such as chip stacking or foreign matter on the chip).

[0029] As a further preferred embodiment, in order to improve the supporting stiffness of the end of the bonding head, a large leaf spring 15 is provided at the bottom of the bonding head shell 1, and a pressure block 16 and a pressure block 2 17 are provided on the outside of the large leaf spring 15. The large leaf spring 15 can increase the stiffness in the horizontal direction and provide flexibility in the vertical direction; the pressure block 16 and the pressure block 2 17 are intended to increase the contact area of ​​the large leaf spring 15 during installation and increase the connection stiffness.

[0030] The moving mechanism in the bonding head box may generate wear particles near the bonding area. When the bonding head is attached, tiny particles will fall onto the wafer, thereby affecting the cleanliness. As a further preferred embodiment, the box is also connected to an exhaust connector 1 4 and an exhaust connector 2 5. An exhaust gap 18 and an exhaust gap 2 19 are provided on the bottom of the box, which cooperate with the exhaust connector 1 4 and the exhaust connector 2 5 to form a circulating airflow from bottom to top. The exhaust gap 18 and the exhaust gap 2 19 are located on both sides of the large leaf spring 15. The design of the exhaust gap 18 and the exhaust gap 2 19 is to reserve an air intake gap for the bonding head box. In cooperation with the exhaust connector 1 4 and the exhaust connector 2 5, a vacuum state is achieved in the bonding head box by vacuuming. The circulating airflow can effectively remove particles and dust in the box and near the bonding area, ensuring a high cleanliness area during bonding, and no particles will fall on the bonded chips.

[0031] As a further preferred embodiment, the brake assembly also includes a T-direction motor fixing flange 63 and a T-direction motor rotating flange 64. The T-direction motor 33 is connected to the Z-direction connecting seat 40 through the T-direction motor fixing flange 63, and can move up and down with the Z-direction connecting seat 40. At the same time, it can also rotate itself to adjust the angle of the chip during patching; the T-direction motor rotating flange 64 is arranged at the lower end of the T-direction motor 33, and the gas spring upper flange 4401 at the upper end of the gas spring 44 is connected to the T-direction motor rotating flange 64. The hollow shaft end at the upper end of the T-direction motor 33 is provided with a T-direction motor connector 41, and the T-direction motor connector 41 is connected to an electromagnetic proportional valve, which controls the compressed gas to pass through the T-direction motor 33 into the gas spring 44 through the electromagnetic proportional valve. The gas spring 44 can provide different thrusts to the nozzle rod 13 according to compressed gases of different pressures, thereby providing corresponding bonding forces.

[0032] Since the pressure output of the gas spring 44 is provided by filling with compressed gas, but the gas spring 44 is a flexible structure, if there is no limit design, the length of the gas spring 44 will be different with the compressed gas pressure, and the elongation will be not fixed, which will cause the Z-axis mechanism height of the bonding head to shift. As a further preferred embodiment, a gas spring fixing column 4402 is provided inside the gas spring 44, and a height adjustment column 70 is provided on the gas spring fixing column 4402. A positioning step is provided at the lower end of the height adjustment column 70, and a flexible hinge 69 is provided on the inner circle of the gas spring upper flange 4401, which can ensure that the gas spring 44 can maintain the same length when filled with gases of different pressures.

[0033] Since the bonding head can only provide a pressure greater than or equal to the gravity of the suction nozzle rod itself, the pressure range is limited. As a further preferred embodiment, a height gap 71 is also provided between the flexible hinge 69 and the height adjustment column 70. The special design of the height gap 71 can ensure that the bonding head provides a pressure starting from 0N, and the force control range is wider. If there is no special design of the height gap 71, when the gas spring 44 is inflated, its own length will gradually extend, and the height gap 71 will gradually decrease until it is 0, that is, the flexible hinge 69 is in contact with the height adjustment column 70. At this time, the gas spring 44 maintains a fixed value, the flexible hinge 69 has a flexible hinge structure, and the interior is a bowl-shaped structure, and the upper end of the height adjustment column 70 is a spherical structure. When the flexible hinge 69 and the height adjustment column 70 are in contact, the height adjustment column 70 can rotate slightly along the spherical direction inside the flexible hinge 69, and will not cause constraints on the automatic leveling of the piezoelectric ceramics, so that the bonding head cannot be automatically leveled.

[0034] As a further preferred embodiment, in order to improve the rigidity and movement accuracy of the box, the box includes a bonding head shell 1 and a shell cover plate 2, and the bonding head shell 1 and the shell cover plate 2 are fixed to form a box by multiple sets of screws. The use of the box structure can effectively improve the rigidity of the mechanism, so as to improve the dynamic performance and accuracy of the mechanism. The bonding head shell 1 and the shell cover plate 2 are made into separate and detachable structures, which take into account both machinability and assemblability while ensuring high rigidity.

[0035] As a further preferred embodiment, in order to improve the applicability of the bonding head, the suction nozzle 14 includes a large-sized portion at the upper end and a small-sized portion at the lower end, and the small-sized portion at the lower end is arranged at the lower end of the large-sized portion at the upper end. The suction nozzle 14 can be made into a square or other shapes, and is composed of two parts of large and small sizes. The large-sized portion remains unchanged, and the small-sized portion can be adjusted to the corresponding size according to customer needs. The large-sized portion remains unchanged to ensure the same installation interface. The interface remains consistent when corresponding to products of different sizes of customers, and can be compatible with suction nozzles of various sizes and specifications; the end of the suction nozzle rod 13 is designed with a fixed-size interface, which can be square or circular or other shapes. The fixed-size installation interface is designed to be compatible with suction nozzles 14 corresponding to chips of various sizes, and the compatibility is higher; the end of the suction nozzle rod 13 is provided with a suction nozzle airway 1301 and a chip airway 1302. Through the internal airway design of the suction nozzle rod 13, in conjunction with the gas input by the chip airway connector 55 and the suction nozzle airway connector 56, the chip can be taken and placed and the suction nozzle 14 can be automatically replaced.

[0036] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A bonding device, characterized in that: include: Box, Z-axis drive assembly, constant force spring assembly, T-axis motor, brake assembly, air bearing assembly, main air bearing, mechanical guide assembly, gas spring, nozzle rod and nozzle; The box body comprises a bonding head housing, a housing mounting seat is provided on the box body, one end of the housing mounting seat is connected to a driving mechanism, and the driving mechanism drives the bonding head device to move horizontally, and a reading head is provided on the box body; The Z-axis driving assembly includes a voice coil motor, a Z-axis connecting seat and a grating ruler assembly. The voice coil motor is fixed in the box and the lower end is connected to the Z-axis connecting seat. The Z-axis connecting seat is driven to move by the voice coil motor. The grating ruler assembly is arranged on the Z-axis connecting seat. The constant force spring assembly is arranged on both sides of the Z-direction connecting seat, and the weight of the Z-direction driving assembly is balanced by the constant force spring assembly; The T-direction motor is arranged on the Z-direction connection seat, the lower end of the T-direction motor is connected to the gas spring, and the upper end of the gas spring is connected to the gas spring upper flange; The brake assembly includes an X-direction brake 1, an X-direction brake 2 and a T-direction brake mechanism, wherein the X-direction brake 1 and the X-direction brake 2 are arranged on both sides of the box body, and the T-direction brake mechanism is connected to a T-direction brake connector, through which a vacuum or atmosphere is introduced into the T-direction brake mechanism, and the T-direction brake mechanism blows air outward to form an air film between the T-direction brake mechanism and the upper flange of the gas spring, allowing the T-direction motor to rotate freely; The air bearing assembly is arranged on both sides of the Z-direction connecting seat, and the air bearing assembly provides air-floating gas to enable the T-direction brake mechanism to perform frictionless movement in the Z-direction; The main air bearing is arranged on the nozzle rod; The mechanical guide rail assembly is arranged at the rear end of the Z-axis connecting seat; The suction nozzle rod is connected to the gas spring, and the suction nozzle is arranged at the lower end of the suction nozzle rod.

2. A bonding device according to claim 1, characterized in that: The air-floating bearing assembly also includes air-floating bearing 1, air-floating bearing 2, guide rod 1, guide rod 2, ball joint 1, ball joint 2, main air-floating bearing and main air-floating bearing joint connected to the main air-floating bearing, chip air path joint and nozzle air path joint. A rotation stop seat is provided at the lower end of the Z-axis connecting seat. The air-floating bearing 1 and the air-floating bearing 2 are interference fit and symmetrically arranged inside the rotation stop seat. The air-floating bearing 1 is provided with an air-floating bearing 1 joint, and the air-floating bearing 2 is provided with an air-floating bearing 2 joint. The guide rod 1 and the guide rod 2 are respectively passed through the air-floating bearing 1 and the air-floating bearing 2, and the ball joint 1 and the ball joint 2 are respectively arranged at the lower ends of the guide rod 1 and the guide rod 2.

3. A bonding device according to claim 1, characterized in that: The constant force spring assembly includes a constant force spring bracket 1, a constant force spring bracket 2, a constant force spring 1 and a constant force spring 2. The constant force spring bracket 1 and the constant force spring bracket 2 are symmetrically fixed on the Z-direction connecting seat. The constant force spring 1 and the constant force spring 2 are symmetrically mounted inside the constant force spring bracket 1 and the constant force spring bracket 2, respectively, and the upper ends of the constant force spring 1 and the constant force spring 2 are locked on the bonding head housing.

4. A bonding device according to claim 1, characterized in that: The lower end of the T-direction brake mechanism is symmetrically installed with T-direction brake return spring 1 and T-direction brake return spring 2; the upper surface of the T-direction brake mechanism is distributed with a T-direction brake mechanism throttle hole and a V-shaped T-direction brake mechanism air path groove, and the T-direction brake mechanism has interconnected cavities inside and the lower surface is sealed by a sealing member.

5. A bonding device according to claim 1, characterized in that: The inner side of the bonding head shell is symmetrically connected with a Z-direction fixing seat 1 and a Z-direction fixing seat 2, and the lower ends of the Z-direction fixing seat 1 and the Z-direction fixing seat 2 are connected with a Z-direction fixing plate, and the lower end surface of the Z-direction fixing plate is fixedly connected with piezoelectric ceramics 1, 2 and 3, and the upper end surfaces of the piezoelectric ceramics 1, 2 and 3 are all planes and the lower end surfaces are all spherical surfaces, and the lower ends of the piezoelectric ceramics 1, 2 and 3 are supported and arranged on the upper surface of the main air-floating sleeve, and the piezoelectric ceramics 1, 2 and 3 are arranged in an isosceles triangle, and high-elastic tension springs for pre-tightening the piezoelectric ceramics 1, 2 and 3 are symmetrically arranged on both sides of the Z-direction fixing plate and the main air-floating sleeve, and the left and right sides of the main air-floating sleeve are connected with small leaf springs and small leaf springs 2 through pressure blocks 3.

6. A bonding device according to claim 1, characterized in that: A gas spring fixing column is provided inside the gas spring, a height adjustment column is provided on the gas spring fixing column, a positioning step is provided at the lower end of the height adjustment column, a flexible hinge is provided on the inner circle of the gas spring upper flange, and a height gap is provided between the flexible hinge and the height adjustment column.

7. A bonding device according to claim 1, characterized in that: The mechanical guide rail assembly is provided with a Z-axis motion plate, the inner side of the bonding head housing is provided with a safety position sensor, a light shielding sheet is slidably provided on the Z-axis motion plate, and the light shielding sheet can block the safety position sensor when it moves; a Z-axis limit block is provided inside the bonding head housing, and the Z-axis limit block is located on one side of the Z-axis motion plate; the grating scale assembly includes a grating scale mounting seat and a grating scale, the grating scale mounting seat is arranged on the Z-axis connecting seat, and the grating scale is arranged on the grating scale mounting seat.

8. A bonding device according to claim 1, characterized in that: A reading head mounting seat is provided on the box body, and the reading head is arranged on the reading head mounting seat. An eddy current sensor support and an eccentric pin fixing seat are also provided on the box body. An eccentric pin is installed on the eccentric pin fixing seat through a top screw locking, and the position of the eddy current sensor support is adjusted by rotating the eccentric pin. An eddy current sensor is clamped on the eddy current sensor support.

9. A bonding device according to claim 1, characterized in that: The box body is also connected to an exhaust connector 1 and an exhaust connector 2, a large leaf spring is provided at the bottom of the bonding head shell, pressure blocks 1 and 2 are provided on the outside of the large leaf spring, and exhaust gaps 1 and 2 are provided on the bottom of the box body, which cooperate with exhaust connectors 1 and 2 to form a circulating airflow from bottom to top, and the exhaust gaps 1 and 2 are located on both sides of the large leaf spring.

10. A bonding device according to claim 1, characterized in that: The brake assembly also includes a T-direction motor fixing flange and a T-direction motor rotating flange. The T-direction motor is connected to the Z-direction connecting seat via the T-direction motor fixing flange. The T-direction motor rotating flange is arranged at the lower end of the T-direction motor. The gas spring upper flange at the upper end of the gas spring is connected to the T-direction motor rotating flange. A T-direction motor connector is provided at the hollow shaft end at the upper end of the T-direction motor. The T-direction motor connector is connected to an electromagnetic proportional valve, and the electromagnetic proportional valve is used to control the compressed gas to pass through the T-direction motor into the interior of the gas spring.

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