A high-precision frictionless placement machine grasping welding head structure

Abstract

The present invention discloses a high-precision frictionless placement machine grasping welding head structure, comprising a pre-pressure adjustment seat, a frictionless double-air floating cylinder fixedly connected to the welding head base, and a guide spring assembly, one end of the pre-pressure adjustment seat is fixedly connected to the bottom end of the welding head base, and the other end of the pre-pressure adjustment seat is provided with a limit adjustment top screw, the limit adjustment top screw is used to adjust the distance between the pre-pressure adjustment seat and the guide spring assembly connected to the bottom end of the motor support seat, and the guide spring assembly is used to offset the component gravity of the air-floating spindle and the R-axis angle motor, and compensate for the R-axis rotation counter-torque; the air-floating structure for providing radial support force of the air-floating spindle and the pneumatic structure for driving the air-floating spindle to move in the Z direction are provided by the frictionless double-air floating cylinder, so as to achieve high-precision frictionless and radial force-free transmission, thereby realizing precise control corresponding to different load forces and precise control of different placement angles.

Description

Technical Field

[0001] The present invention relates to the technical field of chip manufacturing, and in particular to a high-precision frictionless placement machine grasping welding head structure. Background Art

[0002] With the rapid development of the chip manufacturing industry and the increasingly stringent demand for high-precision and high-efficiency production of high-precision placement machines, the technical research and development of high-precision placement machine welding head structures has become an important direction for the development of the industry.

[0003] The high-precision placement machine welding head structure is a key component for achieving high-precision placement of components. It can quickly grab the chip on the wafer through negative pressure, and rely on vision to achieve angle adjustment and precise positioning functions, place the chip on the lead frame, and complete the precise control of different load forces corresponding to chips of different specifications and precise control of different placement angles. Subsequently, the error of each placement is compensated to meet the placement accuracy.

[0004] The existing support angle patch welding head z-axis control is mostly spline bearing guide and air-floating frictionless guide running with transmission structure such as synchronous belt, and the angular position is transmitted by the side of the R-axis motor. The spline bearing has friction, which has a great impact on the force control accuracy under small load conditions; and the radial support force of the air-floating frictionless guide is small, so the tension of the transmission structure such as synchronous belt will affect the air-floating accuracy and cannot achieve stable load force. Summary of the Invention

[0005] The present invention provides a high-precision frictionless placement machine grasping welding head structure to overcome the above technical problems.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] A high-precision frictionless placement machine grasping welding head structure, comprising a pre-pressure adjustment seat, a frictionless double air-floating cylinder fixedly connected to the welding head base, and a guide spring assembly, wherein one end of the pre-pressure adjustment seat is fixedly connected to the bottom end of the welding head base;

[0008] An R-axis angle motor is provided inside the motor support seat, and guide spring assemblies are respectively provided at both ends of the motor support seat, and the two ends of the motor support seat are respectively connected to one end of the guide spring assembly, and the other end of the guide spring assembly is respectively connected to the two ends of the welding head base shell; and a limit adjustment screw is provided at the other end of the pre-pressure adjustment seat, and the limit adjustment screw is used to adjust the distance between the pre-pressure adjustment seat and the guide spring assembly connected to the bottom end of the motor support seat;

[0009] The frictionless double air-floating cylinder includes a cylinder sleeve and an air-floating spindle, and an air-floating structure for providing radial support force for the air-floating spindle and a pneumatic structure for driving the air-floating spindle to move in the Z direction are provided between the cylinder sleeve and the air-floating spindle.

[0010] The output end of the R-axis angle motor passes through the bottom end of the motor support seat and the guide spring assembly in sequence, and is connected to one end of the air-floating spindle through a coupling, and the other end of the air-floating spindle is connected to a suction nozzle for grabbing wafer chips.

[0011] Furthermore, the air-floating structure comprises an upper air-floating porous graphite bearing and a lower air-floating porous graphite bearing, both ends of which are provided with sealing washers;

[0012] The two ends of the cylinder liner are provided with sealing covers with sealing rings, and a main shaft accommodating groove is provided inside the cylinder liner; a first groove structure and a second groove structure for installing an upper air-floating porous graphite bearing and communicating with a lower air-floating porous graphite bearing are respectively provided between the two ends of the main shaft accommodating groove and the cylinder liner.

[0013] A first hole structure connected to the first air pipe joint is provided between the side wall of the first groove structure and the cylinder liner, and an upward floating air pressure relief hole connected to the outside is provided at the bottom end of the first groove structure; a second hole structure connected to the second air pipe joint is provided between the side wall of the second groove structure and the cylinder liner, and a downward floating air pressure relief hole connected to the outside is provided at the top end of the second groove structure;

[0014] The pneumatic structure includes a pressure sensor and a third hole structure for compressed gas to drive the air-floating spindle to move in the Z direction;

[0015] The third hole structure is provided between the first slot structure and the second slot structure, and one side of the third hole structure is connected to the third air pipe joint, and the other side is connected to a connection hole for installing a pressure sensor;

[0016] Furthermore, the air-floating main shaft includes a first shaft component and a second shaft component, and the outer diameter of the first shaft component is smaller than the outer diameter of the second shaft component, and the first shaft component and the second shaft component are fixedly connected to form a stepped structure;

[0017] The connecting end of the second shaft component and the first shaft component is provided with a chamfered structure, and a cavity structure is formed between the stepped structure and the cylinder liner.

[0018] Furthermore, the inner ring diameters of the sealing washers provided on the upper air-floating porous graphite bearing and the lower air-floating porous graphite bearing are both larger than the inner ring diameters of the corresponding air-floating porous graphite bearings.

[0019] Furthermore, the guide spring assembly includes a spring body and a spring mounting plate arranged between adjacent spring bodies;

[0020] Both ends of the spring body are provided with spring connecting plates, and the spring connecting plates include a first fixing plate for connecting to the motor support seat and a second fixing plate for connecting to the welding head base shell;

[0021] In addition, spring reinforcement plates connected by arc-shaped plates are provided on both sides of the spring body.

[0022] Furthermore, the distances between the outer wall of the first shaft component and the inner wall of the upper air-floating porous graphite bearing, and the distances between the outer wall of the second shaft component and the inner wall of the lower air-floating porous graphite bearing are both 8 μm-15 μm.

[0023] Furthermore, the motor support base is also provided with a cooling gas delivery cavity;

[0024] One side of the cooling gas delivery cavity is connected to the cooling gas delivery cavity pipeline, and the other side of the cooling gas delivery cavity is provided with a plurality of cooling gas outlets for heat dissipation of the R-axis angle motor at equal intervals.

[0025] Furthermore, a reading head is installed on the side wall of the motor support seat.

[0026] Beneficial effect: The present invention provides a high-precision frictionless placement machine grasping welding head structure, comprising a pre-pressure adjustment seat, a frictionless double air-floating cylinder fixedly connected to the welding head base, and a guide spring assembly. One end of the pre-pressure adjustment seat is fixedly connected to the bottom end of the welding head base, and the other end of the pre-pressure adjustment seat is provided with a limit adjustment screw. The limit adjustment screw is used to adjust the distance between the pre-pressure adjustment seat and the guide spring assembly connected to the bottom end of the motor support seat. The guide spring assembly offsets the component gravity of the air-floating spindle and the R-axis angle motor, and compensates for the R-axis rotation counter-torque. The air-floating structure for providing radial support force for the air-floating spindle and the pneumatic structure for driving the air-floating spindle to move in the Z direction are provided by the frictionless double air-floating cylinder, thereby achieving high-precision, frictionless and radial force-free transmission, thereby achieving precise control corresponding to different load forces and precise control of different placement angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0028] Figure 1 This is a schematic diagram of a high-precision frictionless placement machine grasping welding head structure of the present invention;

[0029] Figure 2 This is a right view of a high-precision frictionless placement machine grasping welding head structure of the present invention;

[0030] Figure 3 This is a side perspective diagram of a gripping welding head structure of a high-precision frictionless placement machine according to the present invention;

[0031] Figure 4 This is a front view of a high-precision frictionless placement machine grasping welding head structure of the present invention;

[0032] Figure 5 for Figure 4 Cross-sectional view along AA direction;

[0033] Figure 6 is a cross-sectional view of the air-bearing main shaft in this embodiment;

[0034] Figure 7 Schematic diagram of the structure of the guide spring assembly in this embodiment;

[0035] Figure 8 Schematic diagram of the structure of the spring body in this embodiment;

[0036] Figure 9 This is an exploded view of a high-precision frictionless placement machine grasping welding head structure in this embodiment;

[0037] Figure 10 This is a first flow diagram of the welding head force control gas circuit in this embodiment;

[0038] Figure 11 2 is a second flow chart of the welding head force control gas circuit in this embodiment.

[0039] Figure: 1, welding head base; 11, welding head base shell; 2, pre-pressure adjustment seat; 3, frictionless double air-floating cylinder; 31, cylinder sleeve; 311, spindle accommodating groove; 32, air-floating spindle; 01, first shaft component; 02, second shaft component; 021, chamfer structure; 321, third hole structure; 322, third air pipe joint; 33, upper air-floating porous graphite bearing; 331, first groove structure; 3310, first air pipe joint; 3311, first hole structure; 3312, upper air-floating pressure relief hole; 34, lower air-floating porous graphite shaft Bearing; 341, second groove structure; 3410, second air pipe joint; 3411, second hole structure; 3412, downward floating air pressure relief hole; 4, guide spring assembly; 41, spring body; 42, spring mounting plate; 43, spring mounting plate; 44, arc plate; 5, coupling; 6, motor support seat; 60, cooling gas delivery pipeline; 61, cooling gas delivery cavity; 62, cooling gas outlet; 7, R-axis angle motor; 8, suction nozzle; 81, vacuum suction air path; 82, magnet; 9, pressure sensor; 10, reading head. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0041] This embodiment provides a high-precision frictionless placement machine grasping welding head structure, such as Figures 1 to 4 As shown, it includes a pre-pressure adjustment seat 2, a frictionless double air-floating cylinder 3 fixedly connected to the welding head base 1, and a guide spring assembly 4, one end of the pre-pressure adjustment seat 2 is fixedly connected to the bottom end of the welding head base 1, and the other end of the pre-pressure adjustment seat 2 is provided with a limit adjustment screw, and the limit adjustment screw is used to adjust the distance between the pre-pressure adjustment seat 2 and the guide spring assembly 4 connected to the bottom end of the motor support seat 6; the motor support seat 6 is provided with an R-axis angle motor 7, the top and bottom ends of the motor support seat 6 are respectively provided with a guide spring assembly 4, and the top and bottom ends of the motor support seat 6 are respectively connected to one end of the guide spring assembly 4, and the other end of the guide spring assembly 4 is respectively connected to the top and bottom of the welding head base shell 11; and the other end of the pre-pressure adjustment seat 2 is provided with a limit adjustment screw, and the limit adjustment screw is used to adjust the distance between the pre-pressure adjustment seat 2 and the guide spring assembly 4 connected to the bottom end of the motor support seat 6; specifically, as Figures 7 to 9As shown, the guide spring assembly 4 includes a plurality of spring bodies 41 and a spring mounting plate 42 arranged between adjacent spring bodies 41 (and the spring mounting plate 42 close to the end of the motor support seat 6 is a plate structure with an annular through hole, and the spring mounting plate 42 away from the end of the motor support seat 6 is a strip plate structure), and spring connecting plates 43 are provided at both ends of the spring body 41 (including a first fixing plate 430 for connecting the motor support seat 6 and a second fixing plate 431 for connecting the welding head base shell 11, and the first fixing plate 430 / the second fixing plate 431 are curved and transitionally connected to the spring body 41), and spring reinforcement plates 45 are transitionally connected on both sides of the spring body 41 through an arc plate 44, and the angle between the planes of the spring body 41 and the spring reinforcement plate 45 is 70 degrees, that is, the spring body 41 and the spring reinforcement plate 45 are transitionally connected through the arc plate 44 to form an integrated structure, so as to increase the strength of the spring to prevent It bends itself; an R-axis angle motor 7 is provided inside the motor support seat 6, and guide spring assemblies 4 are respectively provided at both ends of the motor support seat 6, and are connected to one end of the guide spring assembly 4, and the other end of the guide spring assembly 4 is respectively connected to the two ends of the welding head base shell 11, so that the guide spring assembly 4 at both ends of the motor support seat 6, the motor support seat 6 and the welding head base shell together form a parallelogram structure to ensure the stability of the z-direction movement, and the force of the spring body 41 is always on the z-axis of the air-floating main shaft, thereby effectively providing a supporting force for balancing the gravity of the air-floating main shaft 32, the coupling 5, the motor support seat 6 and the R-axis angle motor through the guide spring assembly 4, and by adjusting the position of the guide spring assembly 4, the z-axis of the frictionless dual air-floating cylinder 3 is made to coincide with the set z-standard axis, so as to avoid additional radial force between the air-floating main shaft 32 of the frictionless dual air-floating cylinder 3 and the output end of the R-axis angle motor 7. A limit adjustment screw is provided between the top of the pre-pressure adjustment seat 2 and the bottom of the motor support seat 6 for adjusting the pre-initial pressure of the guide spring assembly 4, that is, by adjusting the limit distance between the top of the pre-pressure adjustment seat 2 and the bottom of the motor support seat 6, the guide spring assembly 4 provides an increased pre-pressure when the air-floating main shaft is at the lower limit patch.

[0042] The frictionless dual air-floating cylinder 3 includes a cylinder sleeve 31 and an air-floating spindle 32, and an air-floating structure for providing radial support force for the air-floating spindle 32 and a pneumatic structure for driving the air-floating spindle 32 to move in the Z direction are provided between the cylinder sleeve 31 and the air-floating spindle 32; the output end of the R-axis rotation motor 7 passes through the bottom end of the motor support seat 6 and the guide spring assembly 4 in sequence, and is connected to one end of the air-floating spindle 32 through a coupling 5 (and the positional relationship between the coupling 5 and the pre-pressure adjustment seat 2 is: one end of the pre-pressure adjustment seat 2 is provided with a through-hole structure with a diameter larger than the diameter of the coupling 5) to realize the rotation angle of the R axis of the welding head, and the other end of the air-floating spindle 32 is connected to the suction nozzle 8 for wafer chip grabbing.

[0043] In this embodiment, the guide spring assembly is used to offset the component gravity of the air-floating spindle and the R-axis angle motor, and compensate for the R-axis rotation counter-torque. The air-floating structure for providing radial support force for the air-floating spindle and the pneumatic structure for driving the air-floating spindle to move in the Z direction are provided on the frictionless double air-floating cylinder to realize and achieve high-precision frictionless and radial force-free transmission, thereby achieving precise control corresponding to different load forces and precise control of different patch angles.

[0044] In a specific embodiment, Figures 5 and 6 As shown, the air-floating structure includes an upper air-floating porous graphite bearing 33 and a lower air-floating porous graphite bearing 34, both ends of which are provided with sealing washers (preferably nitrile washers), and the diameter of the upper air-floating porous graphite bearing 33 is larger than the diameter of the lower air-floating porous graphite bearing 34; the two ends of the cylinder sleeve 31 are provided with sealing covers with sealing rings, and the cylinder sleeve 31 is provided with a main shaft accommodating groove 311; the two ends of the main shaft accommodating groove 311 and the cylinder sleeve 31 are respectively provided with a first groove structure 331 and a second groove structure 341 for installing the upper air-floating porous graphite bearing 33 and connecting with the lower air-floating porous graphite bearing 34, and the side of the first groove structure 331 is provided with a sealing ring. A first hole structure 3311 connected to the first air pipe joint 3310 is provided between the wall and the cylinder sleeve 31, and an upward floating air pressure relief hole 3312 connected to the outside world is provided at the bottom end of the first groove structure 331; a second hole structure 3411 connected to the second air pipe joint 3410 is provided between the side wall of the second groove structure 341 and the cylinder sleeve 31, and a downward floating air pressure relief hole 3412 connected to the outside world is provided at the top of the second groove structure 341; specifically, the distance between the outer wall of the first shaft component 01 and the inner wall of the upper air-floating porous graphite bearing 33, and the distance between the outer wall of the second shaft component 02 and the inner wall of the lower air-floating porous graphite bearing 34 are both 8μm-15μm.

[0045] In this embodiment, the upper air-floating porous graphite bearing 33 and the lower air-floating porous graphite bearing 34 installed in the cylinder sleeve 31 are radially sealed by a sealing gasket, and axially sealed by a sealing ring provided on the sealing cover, and compressed gas of different pressures is respectively introduced into the first hole structure 3311 and the second hole structure 3411 through the first air pipe joint 3310 and the second air pipe joint 3410, so that the compressed gas enters the porous graphite bearing evenly from all sides to form a double air-floating structure, and floating holes are left near the cylinder end on both sides. The air pressure relief hole 3312 and the lower floating air pressure relief hole 3412 are used to prevent the floating compressed gas and the cylinder compressed gas from affecting each other and failing. The sealing cover with a sealing ring and the sealing gaskets at both ends of the upper floating porous graphite bearing 33 and the lower floating porous graphite bearing 34 are used to seal the axial and radial directions of the floating structure respectively to ensure the stability of the air film at the upper floating porous graphite bearing 33 and the lower floating porous graphite bearing 34, and the sealing covers at both ends of the cylinder sleeve 31 are connected to the cylinder sleeve 31 by screws to ensure the firmness of the structural connection.

[0046] In a specific embodiment, the pneumatic structure includes a pressure sensor 9 and a third hole structure 321 for compressed gas driving the air-floating main shaft 32 to move in the Z direction; the third hole structure 321 is arranged between the first groove structure 331 and the second groove structure 341, and one side of the third hole structure 321 is connected to the third air pipe joint 322, and the other side is connected to a connection hole for installing the pressure sensor 9. The gas pressure of the third hole structure 321 is measured in real time by the pressure sensor 9, and the electric proportional valve connected to the third air pipe joint 322 is controlled and adjusted according to the detected gas pressure by a preset controller to achieve pressure control of the compressed gas out of the third air pipe joint 322. The control method of the electric proportional valve according to the preset controller is an existing well-known machine technology and will not be repeated here.

[0047] The air-floating main shaft 32 includes a first shaft component 01 and a second shaft component 02, and the outer diameter of the first shaft component 01 is smaller than the outer diameter of the second shaft component 02, and the first shaft component 01 and the second shaft component 02 are fixedly connected to form a stepped structure; the connecting end of the second shaft component 02 and the first shaft component 01 is provided with a chamfered structure 021, and a cavity structure is formed between the stepped structure and the cylinder sleeve 31. The present invention prevents the air-floating main shaft 32 from hitting the upper limit and being stuck, so that the compressed gas cannot enter the cavity structure or enters slowly, resulting in an unbalanced load. Therefore, the chamfered structure is added to enable the air-floating main shaft 32 to always maintain force control under the action of compressed gas. The other end of the air-floating main shaft 32 is provided with a vacuum suction air path 81 and a magnet 82, and the magnet 82 drives the suction nozzle 8 to communicate with the bottom end of the vacuum suction air path 81. By setting a chamfered structure at the step of the air-floating spindle 32 to form a cavity structure between it and the cylinder sleeve 31, and using a pressure sensor to feedback the gas pressure in the cavity structure in real time, the frictionless dual air-floating cylinder 3 can be controlled by controlling the electrical proportional valve to achieve different load conditions. In addition, the bottom end of the air-floating spindle 32 is sealed and connected to different types of suction nozzles through a magnet 82 and a sealing ring, and vacuum air is introduced through the vacuum suction air path 81 to realize the wafer chip grabbing function.

[0048] In this specific embodiment, the inner ring diameter of the sealing gasket arranged on the upper air-floating porous graphite bearing 33 is larger than the inner ring diameter of the upper air-floating porous graphite bearing 33, and the outer ring diameter of the corresponding sealing gasket is equal to the outer ring diameter of the upper air-floating porous graphite bearing 33; wherein, since the lower air-floating structure is closer to the patch end, the lower air-floating porous graphite bearing 34 is used as the main air-floating, and its graphite bearing diameter is larger than the diameter of the upper air-floating porous graphite bearing 33, providing greater radial support force for the air-floating main shaft 32; the inner ring diameter of the sealing gasket arranged on the lower air-floating porous graphite bearing 34 is larger than the inner ring diameter of the lower air-floating porous graphite bearing 34, and the outer ring diameter of the corresponding sealing gasket is equal to the outer ring diameter of the lower air-floating porous graphite bearing 33. That is, by setting the diameter of the sealing gasket, it is convenient to leave gaps between the air-floating main shaft 32 and the upper air-floating porous graphite bearing 33 and the lower air-floating porous graphite bearing 34 at both ends. The gaps are the compressed gas outlets of the dual air-floating structure, thereby ensuring that the compressed gas entering the first hole structure 3311 and the second hole structure 3411 does not leak, while facilitating the discharge of the compressed gas passing through the upper air-floating porous graphite bearing 33 and the lower air-floating porous graphite bearing 34 from both ends along the gaps, thereby forming a dual air-floating structure with a stable air film.

[0049] In a specific embodiment, the motor support seat 6 is also provided with a cooling gas delivery chamber 61; one side of the cooling gas delivery chamber 61 is connected to the cooling gas delivery pipeline 60, and a number of cooling gas outlets 62 are evenly spaced on the other side of the cooling gas delivery chamber 61, so that the solenoid valve arranged in the cooling gas delivery pipeline 60 can be controlled by a preset controller to allow cooling gas to cool the R-axis angle motor.

[0050] In a specific embodiment, a reading head (grating encoder) 10 is installed on the side wall of the motor support base 6. The reading head 10 is fixedly installed on one side of the motor support base 6 through a reading head mounting plate, that is, when the air-floating spindle moves in the Z direction, the reading head 10 is used to monitor the Z-direction displacement of the air-floating spindle during the patch process; the position feedback of the R-axis angle motor driven by the coupling 5 is realized by the encoder provided by the motor.

[0051] The working principle of this embodiment is as follows: Figures 10 and 11 As shown, taking a load of 5g and a 1*1 chip UPH12k as an example: when the welding head is started, the solenoid valve a and the solenoid valve b connected to the first air pipe joint 3310 and the second air pipe joint 3410 are controlled by a preset controller to be normally open, and the total gas source 0.5Mpa compressed gas passes through the pressure reducing valve a and the pressure reducing valve b, and then passes through the first air pipe joint 3310 and the second air pipe joint 3410 respectively into the upper air-floating porous graphite bearing 33 and the lower air-floating porous graphite bearing 34 to form a double air-floating structure, and the pressure reducing valve a and the pressure reducing valve b must ensure that the gas pressure introduced is less than the cylinder pressure in the third hole structure 321 to prevent gas blowby. ; Then, adjust the pre-pressure adjustment seat 2 so that the guide spring assembly 4 balances the gravity of the air-floating spindle 32, the coupling 5, the motor support seat 6 and the R-axis angle motor, and then control the solenoid valve c and the electric proportional valve through the preset controller to introduce compressed gas into the third air pipe joint 322 to move the air-floating spindle 32 downward. When the air-floating spindle 32 drives the motor support seat 6 to contact the top of the adjustment screw of the pre-pressure adjustment seat, the z-direction displacement of the patch process is monitored by the reading head 10, and the patch pressure is measured and calibrated by an additional pressure sensor set at the suction nozzle, and the z-direction position monitored by the reading head 10 is recorded as the Z-direction position of the welding head to grab the chip;

[0052] After the welding head picks up the chip, it moves at high speed on the three-axis module within the standard UPH range, and controls the solenoid valve f to continuously introduce vacuum air above -70kPa into the vacuum suction air path 81, and before reaching the chip position, controls the solenoid valve c and the electric proportional valve to introduce given compressed air into the cylinder air pipe joint, so that the motor support seat 6 is close to the top screw of the pre-pressure adjustment seat 2 to prevent the inertial force generated by all moving parts during high-speed movement from affecting the patch accuracy, so that the welding head is in a fast-drop and high-load state, that is, the welding head fast-drop stage; before the preset safety time before reaching the chip position, controls the solenoid valve c and the electric proportional valve to introduce compressed air with a converted load of 5g into the third air pipe joint 322 to make the motor support seat 6 close to the pre-pressure adjustment seat 2. The force is adjusted to adjust the top screw at the top of the seat 2, so that the welding head is in a slow-descent and small-load state, that is, the slow-descent stage of the welding head. At the same time, the high-sampling-rate pressure sensor 10 provides real-time feedback of the air pressure in the cylinder, and adjusts the air pressure value in the cylinder cavity through the electric proportional valve. The R-axis angle motor is used to rotate to the target position according to the chip rotation angle under the working conditions; after the nozzle touches the chip, the air-floating spindle moves upward, and continuously applies a constant load force to put it in a welding state; the compressed gas is connected to the vacuum suction air path through the solenoid valve f to destroy the vacuum, the chip is separated from the nozzle, and the patch action is completed, and then the compressed gas introduced into the air pipe is controlled to put it in a slow-rise state, and the fast-rise working principle is the same as the slow-rise state, and then the next chip picking cycle is carried out to perform the welding action.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-precision frictionless placement machine grasping welding head structure, characterized in that: It comprises a pre-pressure adjustment seat (2), a frictionless double air-floating cylinder (3) fixedly connected to the welding head base (1), and a guide spring assembly (4), wherein one end of the pre-pressure adjustment seat (2) is fixedly connected to the bottom end of the welding head base (1); An R-axis angle motor (7) is provided inside the motor support seat (6), and guide spring assemblies (4) are provided at both ends of the motor support seat (6), and the two ends of the motor support seat (6) are respectively connected to one end of the guide spring assembly (4), and the other end of the guide spring assembly (4) is respectively connected to the two ends of the welding head base shell (11); and a limit adjustment screw is provided at the other end of the pre-pressure adjustment seat (2), and the limit adjustment screw is used to adjust the distance between the pre-pressure adjustment seat (2) and the guide spring assembly (4) connected to the bottom end of the motor support seat (6); The frictionless double air-floating cylinder (3) comprises a cylinder sleeve (31) and an air-floating main shaft (32), and an air-floating structure for providing radial support force for the air-floating main shaft (32) and a pneumatic structure for driving the air-floating main shaft (32) to move in the Z direction are provided between the cylinder sleeve (31) and the air-floating main shaft (32); The air-floating structure comprises an upper air-floating porous graphite bearing (33) and a lower air-floating porous graphite bearing (34) with sealing washers at both ends; The cylinder sleeve (31) is provided with sealing covers with sealing rings at both ends, and a main shaft accommodating groove (311) is provided inside the cylinder sleeve (31); a first groove structure (331) and a second groove structure (341) for installing an upper air-floating porous graphite bearing (33) and communicating with a lower air-floating porous graphite bearing (34) are respectively provided between the two ends of the main shaft accommodating groove (311) and the cylinder sleeve (31); A first hole structure (3311) communicating with the first air pipe joint (3310) is provided between the side wall of the first groove structure (331) and the cylinder sleeve (31), and an upward floating air pressure relief hole (3312) communicating with the outside is provided at the bottom end of the first groove structure (331); a second hole structure (3411) communicating with the second air pipe joint (3410) is provided between the side wall of the second groove structure (341) and the cylinder sleeve (31), and a downward floating air pressure relief hole (3412) communicating with the outside is provided at the top end of the second groove structure (341); The pneumatic structure includes a pressure sensor (9) and a third hole structure (321) for compressed gas used to drive the air-floating main shaft (32) to move in the Z direction; The third hole structure (321) is arranged between the first slot structure (331) and the second slot structure (341), and one side of the third hole structure (321) is connected to the third air pipe joint (322), and the other side is connected to a connection hole for installing a pressure sensor (9); The output end of the R-axis rotation motor (7) passes through the bottom end of the motor support seat (6) and the guide spring assembly (4) in sequence, and is connected to one end of the air-floating main shaft (32) through a coupling (5), and the other end of the air-floating main shaft (32) is connected to a suction nozzle (8) for grabbing wafer chips.

2. A high-precision frictionless placement machine grasping welding head structure according to claim 1, characterized in that: The air-floating main shaft (32) comprises a first shaft component (01) and a second shaft component (02), wherein the outer diameter of the first shaft component (01) is smaller than the outer diameter of the second shaft component (02), and the first shaft component (01) and the second shaft component (02) are fixedly connected to form a stepped structure; The connecting end of the second shaft component (02) and the first shaft component (01) is provided with a chamfered structure (021), and a cavity structure is formed between the stepped structure and the cylinder sleeve (31).

3. The high-precision frictionless placement machine grasping welding head structure according to claim 2 is characterized in that: The inner ring diameters of the sealing washers provided on the upper air-floating porous graphite bearing (33) and the lower air-floating porous graphite bearing (34) are both larger than the inner ring diameters of the corresponding air-floating porous graphite bearings.

4. The high-precision frictionless placement machine grasping welding head structure according to claim 1 is characterized in that: The guide spring assembly (4) comprises a spring body (41) and a spring mounting plate (42) arranged between adjacent spring bodies (41); Both ends of the spring body (41) are provided with spring connection plates (43), and the spring connection plates (43) include a first fixing plate (430) for connecting to the motor support seat (6) and a second fixing plate (431) for connecting to the welding head base shell (11); Furthermore, spring sheet reinforcement plates (45) are provided on both sides of the spring sheet body (41) and are transitionally connected via arc-shaped plates (44).

5. The high-precision frictionless placement machine grasping welding head structure according to claim 3 is characterized in that: The distances between the outer wall of the first shaft component (01) and the inner wall of the upper air-floating porous graphite bearing (33), and the distances between the outer wall of the second shaft component (02) and the inner wall of the lower air-floating porous graphite bearing (34) are both 8 μm-15 μm.

6. The high-precision frictionless placement machine grasping welding head structure according to claim 1 is characterized in that: The motor support base (6) is further provided with a cooling gas delivery cavity (61); One side of the cooling gas delivery chamber (61) is in communication with the cooling gas delivery pipeline (60), and the other side of the cooling gas delivery chamber (61) is provided with a plurality of cooling gas outlets (62) for heat dissipation of the R-axis angle motor at equal intervals.

7. The high-precision frictionless placement machine grasping welding head structure according to claim 6 is characterized in that: A reading head (10) is installed on the side wall of the motor support seat (6).

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