A new type of pneumatic flexible leveling unit

Abstract

The present invention relates to the field of precision assembly technology, and in particular to a novel pneumatic flexible leveling unit, comprising a fixed seat, an elastic diaphragm, an elastic member, a positioning block, and a floating block; the fixed seat is mounted on a movable mechanism, a groove is provided at the bottom of the fixed seat, and the elastic diaphragm covers the groove to form a closed chamber; the positioning block is mounted at the bottom of the fixed seat, the floating block is nested inside the positioning block, and the bottom end of the floating block extends out of the positioning block and is connected to a suction mechanism; the floating block is connected to the positioning block via an elastic member, the elastic member can be extended and retracted in the vertical direction, and the top end of the floating block is always in contact with the elastic diaphragm; the air pressure in the closed chamber is adjusted to a first air pressure, and when the suction mechanism abuts against the workpiece, the abutment of the suction mechanism is supported by the workpiece, driving the floating block to continuously adjust its own posture. During the process, the inclination difference between the suction mechanism and the workpiece is automatically compensated under the dual elastic forces of the elastic diaphragm deformation and the elastic member extension and retraction, ultimately achieving leveling. The present invention achieves automatic adjustment of parallelism with high precision and strong adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of precision assembly, and in particular to a novel pneumatic flexible leveling unit. Background Art

[0002] In the semiconductor chip manufacturing and packaging process, high-precision assembly processes place extremely strict demands on the parallelism between key components of the equipment (such as the nozzle and carrier of the chip moving device). Currently, the industry generally uses manual methods to adjust the parallelism between the nozzle and the carrier (or the workpiece assembly plane). This method has the following significant problems:

[0003] Manual debugging is difficult: Due to the small size of semiconductor chips and the extremely high positioning accuracy requirements, which usually need to reach the micron level, manual adjustment not only relies on the operator's experience and technical level, but also requires repeated testing and calibration, resulting in long debugging cycles, low efficiency, and difficulty in ensuring consistency.

[0004] High fixture consistency requirements: Factors such as machining errors, assembly tolerances, and mechanical deformation from long-term use among different fixtures or carriers further complicate parallelism adjustment. Manual adjustments are difficult to quickly adapt to the differences between different fixtures and are prone to introducing human errors, affecting chip handling stability and yield.

[0005] Furthermore, traditional rigid adjustment mechanisms lack flexible compensation capabilities, which can easily lead to uneven contact stress between the suction head and the carrier when responding to slight deviations or vibration disturbances, potentially damaging the chip or causing positioning deviation. Therefore, a solution is urgently needed to improve the reliability and production efficiency of semiconductor chip handling equipment. Summary of the Invention

[0006] In view of this, the present invention provides a novel pneumatic flexible leveling unit, which automatically adjusts parallelism with high precision and strong adaptability.

[0007] The present invention is realized through the following technical solutions: a novel pneumatic flexible leveling unit, which is arranged between a moving mechanism and a suction mechanism, and comprises a fixed seat, an elastic diaphragm, an elastic member, a positioning block and a floating block; the fixed seat is mounted on the moving mechanism, a groove is provided at the bottom of the fixed seat, and the elastic diaphragm covers the groove to form a closed chamber; the groove is connected to the peripheral inflation device for adjusting the air pressure in the closed chamber; the positioning block is mounted on the bottom of the fixed seat, a recess is provided at the top of the positioning block, a positioning hole and a through hole are provided at the bottom of the recess, wherein the through hole is located in the middle of the recess; the floating block is divided into a floating platform and an extension connected to the middle of the bottom end of the floating platform, the floating platform is nested in the recess, and a pin corresponding to the position of the positioning hole is provided at the bottom end of the floating platform; the extension extends downward from the through hole and is connected to the suction mechanism; the floating platform is connected to the suction mechanism through the elastic member The bottom of the recess of the positioning block is connected, and the elastic member can be expanded and contracted in the vertical direction. Under the action of the elastic member, the top of the floating block is always in contact with the elastic diaphragm; the air pressure in the closed chamber is adjusted to the first air pressure. After the suction mechanism abuts against the workpiece, the abutment point of the suction mechanism is supported by the workpiece, so that the suction mechanism drives the floating block to continuously adjust its own posture in the vertical direction according to the plane of the workpiece. During the adjustment process, the floating block automatically compensates for the inclination difference between the suction mechanism and the workpiece under the dual elastic force of the deformation of the elastic diaphragm and the expansion and contraction of the elastic member, and finally makes the suction mechanism parallel to the plane of the workpiece, so that it is evenly fitted with the workpiece; the air pressure in the closed chamber is adjusted to the second air pressure, and the second air pressure is greater than the first air pressure. The elastic diaphragm is deformed to push the floating block to overcome the elastic force of the elastic member, so that the pin shaft is inserted into the positioning hole, thereby positioning the floating block in the recess.

[0008] Furthermore, there are at least two positioning holes, and a corresponding number of pins are provided at the bottom end of the floating platform.

[0009] Furthermore, a bushing is provided in the positioning hole, and the bushing is interference fit with the positioning hole; and only one of the bushings is a circular hole bushing, and the rest are oblong hole bushings.

[0010] Furthermore, several elastic members are evenly arranged between the bottom end of the floating platform and the bottom of the recess; the bottom end of the floating platform is provided with several first card slots, the bottom of the recess is provided with several second card slots, and the two ends of the elastic member are respectively arranged in the first card slot and the second card slot.

[0011] Furthermore, the extending portion of the floating block is connected to the suction mechanism via a limit block, and the limit block is used to limit the upward travel of the floating block.

[0012] Furthermore, the elastic diaphragm is made of a composite material of rubber and fiber.

[0013] Compared with the existing technology, the beneficial effects of the present invention are:

[0014] 1. In the present invention, after the suction mechanism contacts the workpiece, the floating block continuously adjusts the posture of the suction mechanism under the combined force of the deformation of the elastic diaphragm and the expansion and contraction of the spring, so that the suction mechanism automatically compensates for the inclination difference with the plane of the workpiece, and finally makes the suction mechanism fit the workpiece; it effectively eliminates the off-load stress of traditional rigid assembly, improves the stability and precision of the workpiece suction process, and automatically adjusts the level throughout the process without manual debugging. At the same time, it has good adaptability and can be adapted to different suction heads and chip carriers, reducing processing costs.

[0015] 2. The floating block of the present invention is equipped with a pin that cooperates with the positioning block bushing to limit the floating block within the positioning block, ensuring the stability of the suction mechanism during movement. By changing the air pressure, the elastic diaphragm is deformed, thereby pushing the floating block, achieving the switching between positioning and floating of the floating block.

[0016] 3. The present invention has only one circular hole bushing to ensure the alignment accuracy between the floating platform and the positioning block, and the other oblong hole bushings prevent the floating block from getting stuck during the floating process.

[0017] 4. The elastic diaphragm of the present invention is made of a composite material of rubber and fiber. The rubber ensures the elasticity of the elastic diaphragm, and the fiber embedded in the rubber can improve the rigidity of the elastic diaphragm, so that the elastic diaphragm can still support the upward reaction force of the floating block when it is compressed and deformed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is an exploded view of the overall structure of the present invention.

[0019] Figure 2 It is a cross-sectional view of the present invention.

[0020] Among them, 1-elastic part, 2-fixed seat, 3-groove, 4-limiting block, 5-positioning block, 6-floating block, 7-elastic diaphragm, 8-inflating hole, 9-circular hole bushing, 10-positioning hole, 11-through hole, 12-pin shaft, 13-oblong hole bushing. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] A suction mechanism (such as a suction head) sucks the workpiece from the assembly platform or carrier. The suction mechanism is generally directly connected to a moving mechanism (such as a rotating shaft). The present invention provides a new pneumatic flexible leveling unit. The leveling unit is arranged between the moving mechanism and the suction mechanism. When the suction mechanism contacts the workpiece, the leveling unit automatically adjusts the parallelism of the suction mechanism and the workpiece according to the plane posture of the workpiece, that is, adjusts the inclination angle of the plane where the suction mechanism and the workpiece are in contact, so that the suction mechanism is parallel to the workpiece, thereby being able to completely fit the workpiece, avoiding chip damage or positioning offset due to uneven contact stress between the suction mechanism and the workpiece.

[0023] like Figure 1 As shown, the leveling unit includes a fixed base 2, an elastic diaphragm 7, an elastic member 1, a positioning block 5, a floating block 6, and a limit block 4. The fixed base 2 is mounted on the moving mechanism. A groove 3 is defined at the bottom of the fixed base 2, the horizontal cross-section of which completely covers the plane of the workpiece to be sucked. A gas filling hole 8 is provided at the top of the fixed base 2, communicating with the groove 3. The elastic diaphragm 7 covers the groove 3, forming a sealed chamber. The gas filling hole 8 is connected to an external gas filling device, and a proportional valve is installed in the connecting pipeline. The proportional valve is used to adjust the total amount of gas filled into the sealed chamber, thereby adjusting the gas pressure within the sealed chamber.

[0024] In this embodiment, the top of the fixing base 2 is connected to the moving mechanism through fasteners. The four corners of the fixing base 2 are provided with mounting holes, and bolts are passed through the mounting holes to be fixed to the moving mechanism.

[0025] A positioning block 5 is mounted at the bottom of the fixed base 2, while a floating block 6 is nested within it. The bottom end of the floating block 6 extends beyond the positioning block 5 and is connected to the suction mechanism via a limit block 4. This limit block 4 limits the vertical upward travel of the floating block 6. The floating block 6 is connected to the positioning block 5 via an elastic member 1. This elastic member 1 is vertically retractable and always in a compressed state. The elastic force of this elastic member 1 ensures that the top end of the floating block 6 is always in contact with the elastic diaphragm 7.

[0026] In a specific implementation, the top of the positioning block 5 can completely cover the elastic diaphragm 7, and fasteners can be used to connect the fixing base 2, the elastic diaphragm 7, and the positioning block 5 together. In this embodiment, the elastic diaphragm 7 is rectangular, and the positioning block 5 is a cubic structure. Threaded holes are provided at the four corners of the elastic diaphragm 7, the four corners of the positioning block 5, and the corresponding positions of the fixing base 2. The three are connected together by bolts.

[0027] When it is necessary to absorb a workpiece, gas is injected into the groove 3 through the gas filling hole 8, causing the gas pressure in the sealed chamber to reach a first pressure. This first pressure causes the elastic diaphragm 7 to deform. The suction mechanism is then lowered to contact the workpiece. In the initial state, because the suction mechanism and the workpiece plane are not parallel, the suction mechanism and the workpiece partially abut each other. The abutment of the suction mechanism is supported by the workpiece, causing the suction mechanism to float the floating block 6 in the vertical direction. During the floating process, the floating block 6 automatically compensates for the inclination difference between the suction mechanism and the workpiece under the dual elastic forces of the deformation of the elastic diaphragm 7 and the expansion and contraction of the elastic member 1 until the suction mechanism and the workpiece plane are parallel, that is, the suction mechanism and the workpiece are evenly attached.

[0028] Floating means that the suction mechanism and the floating block 6 continuously adjust their own posture in the vertical direction according to the plane of the workpiece, so that the suction mechanism is parallel to the plane of the workpiece and can fit completely and evenly with the plane of the workpiece. The floating process is not a nonlinear movement, but a posture adjustment process of the suction mechanism and the floating block 6 as a whole.

[0029] Specifically, the positioning block 5 has a recessed top, with a positioning hole 10 and a through-hole 11 defined at its bottom. The through-hole 11 is located in the middle of the recess, extending through the bottom surface of the positioning block 5. The positioning holes 10 are arranged around the through-hole 11, but do not extend through the bottom of the recess. The floating block 6 comprises a floating platform and an extension connected to the middle of the bottom end of the platform. The floating platform is located within the recess, and a pin 12 is located at the bottom end of the floating platform, corresponding to the position of the positioning hole 10. The extension extends downward from the through-hole 11 and connects to the suction mechanism through the stop block 4. In this embodiment, a connecting hole is provided at the bottom end of the floating platform, into which the pin 12 is inserted with an interference fit. A bushing is located within the positioning hole 10, forming an interference fit with the positioning hole 10.

[0030] When not in contact with the workpiece, in order to ensure the stability of the suction mechanism during movement, the floating block 6 can be limited in the positioning block 5, as follows: Figure 2 As shown, gas is filled into the groove 3 through the inflation hole 8, so that the gas pressure in the closed chamber is a second air pressure, which is greater than the first air pressure. The second air pressure causes the elastic diaphragm 7 to deform, and the deformation of the elastic diaphragm 7 pushes the floating block 6 to overcome the elastic force of the elastic part 1, so that the pin shaft 12 is inserted into the bushing of the positioning hole 10, thereby positioning the floating block 6 in the recess of the positioning block 5.

[0031] On the basis that the floating block 6 is limited in the positioning block 5, if the workpiece needs to be sucked, there is no need to introduce gas into the closed chamber through the inflation hole 8. Instead, the gas pressure in the closed chamber is reduced from the second air pressure to the first air pressure through the proportional valve. At this time, the elastic diaphragm 7 is deformed and becomes smaller, and the downward thrust of the elastic diaphragm 7 on the floating block 6 becomes smaller. The floating block 6 moves upward under the elastic force of the elastic part 1, and the pin shaft 12 disengages from the bushing of the positioning hole 10, that is, the floating block 6 can float in the positioning block 5, and then the operation of sucking the workpiece and leveling it is performed.

[0032] As an improvement, there are at least two positioning holes 10, optimally symmetrically arranged on either side of the through-hole 11. A corresponding number of pins 12 are located at the bottom of the floating platform. The bushings are divided into circular-hole bushings 9 and oblong-hole bushings 13; only one of these is circular-hole bushing 9, while the remaining oblong-hole bushings 13 are oblong-hole bushings. The circular-hole bushing 9 ensures accurate alignment between the floating platform and the positioning block 5, while the remaining oblong-hole bushings 13 prevent the floating block 6 from jamming during floating.

[0033] In this embodiment, several elastic members 1 are evenly spaced between the bottom of the platform and the bottom of the recess. These elastic members 1 are linear springs. The bottom of the platform is provided with several first slots, and the bottom of the recess is provided with several second slots. The ends of the elastic members 1 are positioned in the first and second slots, respectively.

[0034] In this embodiment, the top of the limit block 4 is connected to the bottom of the extension of the floating block 6 via fasteners, and the bottom of the limit block 4 is connected to the suction mechanism via bolts. When the floating platform is restrained in the positioning block 5 (the pin 12 is fully inserted into the bushing), the distance A between the top of the limit block 4 and the bottom of the positioning block 5 represents the vertical floating travel of the floating platform. By adjusting the distance A, the upward travel range of the floating platform is restricted.

[0035] In this embodiment, the elastic diaphragm 7 is made of a composite material of rubber and fiber, wherein the rubber ensures the elasticity of the elastic diaphragm 7, and the fiber embedded in the rubber can improve the rigidity of the elastic diaphragm 7, so that the elastic diaphragm 7 can still support the upward reaction force of the floating block 6 when it is compressed and deformed.

[0036] The present invention can be applied to semiconductor chip handling equipment to achieve precise adjustment of the parallelism between the chip suction head and the carrier. In a specific implementation, the pin 12 uses a φ3mm pin with a tolerance of 0 / +0.002mm, and the inner diameter of the circular hole bushing 9 is φ3mm with a tolerance of +0.002 / +0.008mm, ensuring a 0.006mm alignment accuracy between the pin 12 and the circular hole bushing 9. At the same time, in order to ensure that the floating block 6 does not get stuck during the process of being limited in the positioning block 5 and detaching from the positioning block 5, the bushing can use only one circular hole bushing 9, and the rest can use oblong hole bushings 13 (width 3mm, long axis direction ±0.1mm tolerance); the pin can be provided with a guide section with a length of 2mm to facilitate insertion into the bushing; in addition, the positioning height of the pin and the bushing can be minimized, and the length of the positioning section of the pin can be set to 1mm, that is, the total length of the bushing can be set to 3mm.

[0037] In its initial state, i.e., when not inflated, the elastic diaphragm 7 is undeformed, the spring is compressed, and the spring forces the floating block 6, causing its top end to contact the elastic diaphragm 7. During the movement of the nozzle, the floating block 6 is held in place by the positioning block 5. Compressed gas is then introduced into the sealed chamber, reaching a pressure of 0.5 MPa. This causes the elastic diaphragm 7 to deform axially, pushing the floating block 6 downward, overcoming the spring force. The pin on the floating block 6 then precisely engages the bushing on the positioning block 5, ensuring the nozzle remains stable during movement.

[0038] When the chip is sucked up, the air pressure in the closed chamber is dynamically adjusted to the range of 0.05-0.2MPa through the proportional valve, and the axial force of the elastic diaphragm 7 on the floating block 6 is weakened accordingly. The floating block 6 moves upward under the action of the spring, and the floating block 6 is separated from the positioning block 5. During the process, the floating block 6 is always in contact with the elastic diaphragm 7. According to specific usage requirements, the air pressure in the closed chamber can be adjusted through the proportional valve pressure closed-loop control and the maximum upward stroke of the floating block 6 can be set through the limit block 4, which is equivalent to controlling the floating stroke range of the floating block 6 in the vertical direction. For example, the vertical floating stroke range of the floating block 6 can be set to a fine-motion stroke of ±1mm. After the floating block 6 is separated from the positioning block 5 and is 1mm away from the positioning block 5 (the distance between the bottom end of the pin and the top end of the bushing is 1mm), the floating state can be adjusted.

[0039] The floating adjustment process is that under the combined force of the deformation of the elastic diaphragm 7 and the expansion and contraction of the spring, the floating block 6 automatically compensates for the inclination difference between the suction head and the chip plane. The elastic diaphragm 7 is a nonlinear elastic deformation of each point on the overall plane. During the process, the floating block 6 is subjected to force to continuously adjust the posture of the limit block 4 in the vertical direction, that is, to adjust the posture of the suction head until the suction head and the chip plane are evenly fitted in the entire area, effectively eliminating the off-load stress of traditional rigid assembly, improving the stability of the chip suction process, and eliminating the need for manual debugging, thereby improving efficiency. At the same time, it has good adaptability and can be adapted to different suction heads and chip carriers, reducing processing costs.

[0040] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A new type of pneumatic flexible leveling unit, characterized in that: The leveling unit is arranged between the moving mechanism and the suction mechanism, and includes a fixing seat, an elastic diaphragm, an elastic member, a positioning block and a floating block; The fixing seat is mounted on the moving mechanism, and a groove is provided at the bottom of the fixing seat. The elastic diaphragm covers the groove to form a closed chamber. The groove is connected to the peripheral inflation device to adjust the air pressure in the closed chamber. The positioning block is installed at the bottom of the fixing seat, and the top of the positioning block is provided with a recess, and the bottom of the recess is provided with a positioning hole and a through hole, wherein the through hole is located in the middle of the recess; the floating block is divided into a floating platform and an extension connected to the middle of the bottom end of the floating platform, the floating platform is nested in the recess, and the bottom end of the floating platform is provided with a pin corresponding to the position of the positioning hole; the extension extends downward from the through hole and is connected to the suction mechanism; the floating platform is connected to the bottom of the recess of the positioning block through an elastic member, and the elastic member can be stretched in the vertical direction. Under the action of the elastic member, the top of the floating block is always in contact with the elastic diaphragm; The air pressure in the sealed chamber is adjusted to a first air pressure. When the suction mechanism contacts the workpiece, the contact point of the suction mechanism is supported by the workpiece, causing the suction mechanism to drive the floating block to continuously adjust its posture in the vertical direction according to the plane of the workpiece. During the adjustment process, the floating block automatically compensates for the inclination difference between the suction mechanism and the workpiece under the dual elastic forces of the deformation of the elastic diaphragm and the expansion and contraction of the elastic member, ultimately making the suction mechanism parallel to the plane of the workpiece, thereby evenly fitting the workpiece. The air pressure in the sealed chamber is adjusted to a second air pressure which is greater than the first air pressure. The elastic diaphragm is deformed to push the floating block to overcome the elastic force of the elastic member, so that the pin shaft is inserted into the positioning hole, thereby positioning the floating block in the recess.

2. The novel pneumatic flexible leveling unit according to claim 1, characterized in that: There are at least two positioning holes, and a corresponding number of pins are provided at the bottom end of the floating platform.

3. The novel pneumatic flexible leveling unit according to claim 2, characterized in that: A bushing is provided in the positioning hole, and the bushing is interference fit with the positioning hole; and only one of the bushings is a circular hole bushing, and the rest are oblong hole bushings.

4. The novel pneumatic flexible leveling unit according to claim 1, characterized in that: Several elastic members are evenly arranged between the bottom of the floating platform and the bottom of the recess; the bottom of the floating platform is provided with several first slots, the bottom of the recess is provided with several second slots, and the two ends of the elastic member are respectively arranged in the first slots and the second slots.

5. The novel pneumatic flexible leveling unit according to any one of claims 1 to 4, characterized in that: The extending portion of the floating block is connected to the suction mechanism through a limit block, and the limit block is used to limit the upward stroke of the floating block.

6. The novel pneumatic flexible leveling unit according to claim 5, characterized in that: The elastic diaphragm is made of a composite material of rubber and fiber.

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