Pressure-controllable chip mounting head

Abstract

The invention provides a pressure-controllable chip mounting head. The pressure-controllable chip mounting head comprises a vertical driving assembly, a first-stage sliding assembly and a second-stage sliding assembly, the first-stage sliding assembly comprises a first-stage sliding table; the second-stage sliding assembly comprises a second-stage sliding table; a hollow rotating shaft is rotatably mounted in the secondary sliding table, and a suction head is fixed at the bottom of the hollow rotating shaft; a spring assembly is mounted between the first-stage sliding table and the second-stage sliding table; a grating ruler is fixed on the first-stage sliding table, and a reading head is fixed on the second-stage sliding table at a position corresponding to the grating ruler; the spring assembly comprises an extension spring and an adjusting spring assembly, and the extension spring is connected with the first-stage sliding table and the second-stage sliding table so that the second-stage sliding table can be hung below the first-stage sliding table. The adjusting spring assembly comprises a spring guide column, the top of the spring guide column is fixed to the first-stage sliding table, and the bottom of the spring guide column is inserted into the second-stage sliding table in a sliding mode. And a large spring and a small spring are sleeved on the spring guide post. The pressure control difficulty is low, the technical threshold is low, and the chip mounting head is small in overall structure and low in cost.

Description

Technical Field

[0001] The invention relates to the technical field of chip mounting, in particular to a pressure-controllable chip mounting head. Background Art

[0002] In recent years, the semiconductor industry has been booming, and the demands for related chip packaging have emerged one after another. Taking eutectic machines, die bonding machines and sintering machines as examples, their common feature is that different pressures need to be provided during the chip mounting process to achieve the process purpose of chip mounting. Especially for SiC chip-related chip mounting, the pressure control needs to be more precise, so many chip mounting heads that control the pressure of picking up and mounting chips have been born.

[0003] There are two main types of existing chip placement heads:

[0004] A chip placement head adopts a multi-motor method to realize the large and small forces of chip placement. Generally, dual motors are used to control the large and small forces respectively. This technical method forces the overall structure of the chip placement head to be too large, the stroke is shortened, and the cost is increased, which is not conducive to the current demand for miniaturization and cost reduction of various placement equipment.

[0005] Another type of chip mounting head uses strain gauges or pressure sensors to control pressure. This type of chip mounting head is limited by the strain gauge material and the pressure range it controls is very limited. Generally, multiple sensors or strain gauges with different ranges must be used at the same time to control excessive or insufficient pressure separately.

[0006] The chip placement head in the prior art has an overall structure that is too large and costly, and has the problems of high difficulty in pressure control and high technical threshold. Summary of the invention

[0007] The present invention proposes a pressure-controllable chip mounting head to solve the technical problems of the prior art chip mounting head having an overly large overall structure, high cost, high difficulty in pressure control and high technical threshold.

[0008] One aspect of the present invention is to provide a pressure-controllable chip mounting head, the chip mounting head comprising at least a fixed mounting seat, a vertical drive assembly, a primary sliding assembly and a secondary sliding assembly;

[0009] The vertical drive assembly is mounted on the fixed mounting seat; the primary sliding assembly comprises at least a primary sliding platform;

[0010] The vertical driving assembly is connected to the primary slide of the primary sliding assembly, and is used to drive the primary slide to reciprocate in the vertical direction;

[0011] The secondary sliding assembly at least comprises a secondary slide; a hollow rotating shaft is rotatably installed in the secondary slide along the vertical direction, and a suction head is fixed at the bottom of the hollow rotating shaft;

[0012] Wherein, a spring assembly is installed between the primary slide and the secondary slide; a grating ruler is fixed on the primary slide, and a reading head is fixed on the secondary slide corresponding to the position of the grating ruler;

[0013] Wherein, the spring assembly includes a tension spring, one end of which is fixed to the primary slide, and the other end of which is fixed to the secondary slide, so that the secondary slide is suspended below the primary slide and the secondary slide is free to move in a vertical direction relative to the primary slide;

[0014] Wherein, the spring assembly further comprises an adjusting spring assembly, the adjusting spring assembly comprises a spring guide column, the top of the spring guide column is fixed to the primary slide, and the bottom of the spring guide column is inserted into the secondary slide in a sliding manner;

[0015] Wherein, a limiting nut and a limiting sleeve are fixed on the spring guide column, and the limiting sleeve is located below the limiting nut; a large spring is sleeved on the spring guide column, and the large spring is located between the limiting nut and the limiting sleeve;

[0016] A small spring is sleeved on the spring guide column, and the small spring is located between the limiting sleeve and the secondary slide.

[0017] In a preferred embodiment, the vertical drive assembly includes a first motor, a ball screw shaft and a ball screw seat;

[0018] The first motor is fixed on the fixed mounting seat, and the ball screw shaft is connected to the output shaft of the first motor; the ball screw seat is fixed to the primary slide, and the ball screw shaft is installed in the ball screw seat and passes through the primary slide;

[0019] When the first motor drives the ball screw shaft to rotate, the ball screw shaft drives the ball screw seat to reciprocate in the vertical direction, thereby driving the primary slide to reciprocate in the vertical direction.

[0020] In a preferred embodiment, the vertical drive assembly further includes a first motor mounting seat, the first motor is fixed on the first motor mounting seat, and the first motor mounting seat is fixed on the fixed mounting seat.

[0021] In a preferred embodiment, the output shaft of the first motor is connected to the ball screw shaft through a first coupling.

[0022] In a preferred embodiment, the primary sliding assembly further comprises a slide rail and a slider;

[0023] The slider is fixed to the primary slide, the slide rail is fixed to the fixed mounting seat, and the slider is slidably connected to the slide rail;

[0024] When the primary slide table reciprocates along the vertical direction, the slider reciprocates along the slide rail.

[0025] In a preferred embodiment, a cross roller guide is installed between the primary slide and the secondary slide.

[0026] In a preferred embodiment, the chip placement head further comprises a rotation drive assembly;

[0027] The rotary drive assembly includes a second motor, a hollow ball spline shaft and a ball spline seat;

[0028] The second motor is fixed on the fixed mounting seat, and the ball spline seat is rotatably mounted in the fixed mounting seat; the second motor is used to drive the ball spline seat to rotate;

[0029] The hollow ball spline shaft is installed in the ball spline seat, and the hollow ball spline shaft is configured to reciprocate in a vertical direction relative to the ball spline seat, and the hollow ball spline shaft is driven to rotate when the ball spline seat rotates;

[0030] The hollow ball spline shaft passes through the fixed mounting seat and the primary slide, and is connected to the hollow rotating shaft;

[0031] When the ball spline seat rotates and drives the hollow ball spline shaft to rotate, the hollow ball spline shaft drives the hollow rotating shaft and the suction head to rotate.

[0032] In a preferred embodiment, the outer surface of the hollow ball spline shaft is provided with a first ball groove extending in the vertical direction, and the inner surface of the ball spline seat is provided with a second ball groove extending in the vertical direction;

[0033] Balls are installed in the first ball groove and the second ball groove, so that the hollow ball spline shaft reciprocates relative to the ball spline seat in a vertical direction, and the hollow ball spline shaft is driven to rotate when the ball spline seat rotates.

[0034] In a preferred embodiment, the rotary drive assembly further comprises a second motor mounting seat, the second motor is fixed on the second motor mounting seat, and the second motor mounting seat is fixed on the fixed mounting seat;

[0035] The output shaft of the second motor is connected to the first pulley, and the ball spline seat fixes the second pulley; a belt is arranged around the first pulley and the second pulley;

[0036] When the second motor drives the first pulley to rotate, the second pulley drives the ball spline seat to rotate.

[0037] In a preferred embodiment, an air extraction interface is installed on the top of the hollow ball spline shaft;

[0038] The bottom of the hollow ball spline shaft is connected to the hollow rotating shaft through a second coupling.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The present invention proposes a pressure-controllable chip mounting head, in which a grating ruler is fixed on a primary slide, a reading head is fixed at a position corresponding to the grating ruler on a secondary slide, a spring assembly is installed between the primary slide and the secondary slide, and the elongation of the tension spring and the compression of the large spring and the small spring are read by the reading head, thereby obtaining the pressure of the suction head on the chip, and further controlling the pressure of the chip.

[0041] The present invention provides a pressure-controllable chip mounting head, which has low pressure control difficulty and low technical threshold, a small overall structure of the chip mounting head, low cost, and more convenient chip mounting head routing. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation of the present invention or the technical solution in the prior art, the following briefly introduces the drawings required for use in the specific implementation or the prior art description. Obviously, the drawings described below are some implementations of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 It is a three-dimensional view of a pressure-controllable chip mounting head of the present invention.

[0044] Figure 2 It is a front view of a pressure-controllable chip mounting head of the present invention.

[0045] Figure 3 It is a three-dimensional view of the primary sliding assembly, the secondary sliding assembly and the spring assembly of the present invention being connected to each other.

[0046] Figure 4 It is a front view of the primary sliding assembly, the secondary sliding assembly and the spring assembly of the present invention being connected to each other.

[0047] Figure 5is a side view of the interconnection of the primary sliding assembly, the secondary sliding assembly and the spring assembly of the present invention (by Figure 4 (from the right side of the image, looking left).

[0048] Figure 6 Schematic diagram of the adjusting spring assembly of the present invention.

[0049] Figure 7 yes Figure 6 Cross-sectional view along the AA direction.

[0050] Figure 8 It is a schematic diagram of the hollow ball spline shaft of the present invention being installed in the ball spline seat.

[0051] Fig. 9 yes Figure 8 Cross-sectional view along the BB direction. DETAILED DESCRIPTION

[0052] In order to make the above and other features and advantages of the present invention more clear, the present invention is further described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explaining to those skilled in the art and are only exemplary and not restrictive.

[0053] Combination Figures 1 to 9 According to an embodiment of the present invention, a pressure-controllable chip mounting head is provided. The chip mounting head includes a mounting adapter plate 1, a fixed mounting seat 2, a vertical drive assembly 3, a primary sliding assembly 4, a secondary sliding assembly 5, a spring assembly 6, a rotation drive assembly 7 and a suction head 8.

[0054] The installation adapter plate 1 is fixed on a machine platform (not shown in the figure), and the fixed mounting seat 2 is fixed to the installation adapter plate 1, so that the fixed mounting seat 2 is fixed on the machine platform.

[0055] Combination Figure 1 and Figure 2 According to an embodiment of the present invention, the vertical drive assembly 3 is mounted on the fixed mounting seat 2. Specifically, the vertical drive assembly 3 includes a first motor mounting seat 301, a first motor 302, a ball screw shaft 303, a ball screw seat 304 and a first coupling 305.

[0056] The first motor 302 is fixed on the fixed mounting seat 2, and the ball screw shaft 303 is connected to the output shaft of the first motor 302. Specifically, the first motor 302 is fixed on the first motor mounting seat 301, and the first motor mounting seat 301 is fixed on the fixed mounting seat 2, so that the first motor 302 is fixed on the fixed mounting seat 2. The output shaft of the first motor 302 is connected to the ball screw shaft 303 through the first coupling 305, so that the ball screw shaft 303 is connected to the output shaft of the first motor 302.

[0057] The ball screw shaft 303 is installed in the ball screw seat 304. When the first motor 302 drives the ball screw shaft 303 to rotate, the ball screw shaft 303 drives the ball screw seat 304 to reciprocate in the vertical direction.

[0058] Combination Figure 1 and Figure 2 According to an embodiment of the present invention, the primary sliding assembly 4 includes a primary sliding table 401 , a sliding rail 402 , a slider 403 and a grating ruler 404 .

[0059] The vertical driving assembly 3 is connected to the primary slide 401 of the primary sliding assembly 4 and is used to drive the primary slide 401 to reciprocate in the vertical direction.

[0060] Specifically, the ball screw seat 304 of the vertical driving assembly 3 is fixed to the primary slide 401 , and the ball screw shaft 303 is installed in the ball screw seat 304 and passes through the primary slide 401 .

[0061] When the first motor 302 drives the ball screw shaft 303 to rotate, the ball screw shaft 303 drives the ball screw seat 304 to reciprocate in the vertical direction, thereby driving the primary slide 401 to reciprocate in the vertical direction.

[0062] The slider 403 is fixed to the primary slide 401, the slide rail 402 is fixed to the fixed mounting seat 2, and the slider 403 is slidably connected to the slide rail 402. When the primary slide 401 reciprocates along the vertical direction, the slider 403 reciprocates along the slide rail 402.

[0063] The grating ruler 404 is fixed on the primary slide 401. When the primary slide 401 reciprocates in the vertical direction, the grating ruler 404 reciprocates in the vertical direction synchronously with the primary slide 401.

[0064] Combination Figure 1 and Figure 2 According to an embodiment of the present invention, the secondary sliding assembly 5 includes a secondary slide 501, a cross roller guide 502, a reading head 503 and a hollow rotating shaft 504.

[0065] A cross roller guide rail 502 is installed between the primary slide 401 and the secondary slide 501. In the vertical direction, a hollow shaft 504 is installed in a rotatable manner in the secondary slide 501, and a suction head 8 is fixed at the bottom of the hollow shaft 504.

[0066] A spring assembly 6 is installed between the primary slide 401 and the secondary slide 501. A grating ruler 404 is fixed on the primary slide 401, and a reading head 503 is fixed on the secondary slide 501 at a position corresponding to the grating ruler 404.

[0067] Combination Figure 3 , Figure 4 and Figure 5 According to an embodiment of the present invention, the spring assembly 6 includes a tension spring 601 and an adjustment spring assembly 602 .

[0068] One end of the tension spring 601 is fixed to the primary slide 401, and the other end of the tension spring 601 is fixed to the secondary slide 501, so that the secondary slide 501 is suspended below the primary slide 401 and can move freely in the vertical direction relative to the primary slide 401.

[0069] Specifically, the two ends of the tension spring 601 are fixed with tension spring columns 603, and the tension spring columns 603 at the two ends of the tension spring 601 are respectively fixed to the primary slide 401 and the secondary slide 501, so that the secondary slide 501 is suspended below the primary slide 401. The tension spring 601 suspends the secondary slide 501 below the primary slide 401, and the tension spring 601 is in a tensioned state.

[0070] like Figure 5 As shown, in this embodiment, two tension springs 601 are provided so that the secondary slide 501 is stably suspended below the primary slide 401. The number of tension springs 601 is not specifically limited, and the tension springs 601 can be one or more, which are specifically provided according to actual needs.

[0071] Combination Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 According to an embodiment of the present invention, the adjusting spring assembly 602 includes a spring guide column 6021, the top of the spring guide column 6021 is fixed to the primary slide 401, and the bottom of the spring guide column 5021 is inserted into the secondary slide 501 in a sliding manner.

[0072] A limiting nut 6025 and a limiting sleeve 6023 are fixed on the spring guide column 6021, and the limiting sleeve 6023 is located below the limiting nut 6025. A large spring 6022 is sleeved on the spring guide column 6021, and the large spring 6022 is located between the limiting nut 6025 and the limiting sleeve 6023.

[0073] A small spring 6024 is sleeved on the spring guide column 6021 , and the small spring 6022 is located between the limiting sleeve 6023 and the secondary slide 501 (the upper surface of the secondary slide 501 ).

[0074] When the tension spring 601 suspends the secondary slide 501 under the primary slide 401, the tension spring 601 is in a stretched state, the large spring 6022 is located between the limit nut 6025 and the limit sleeve 6023 and is in an initial state (the large spring 6022 is neither stretched nor compressed), and the small spring 6024 is located between the limit sleeve 6023 and the secondary slide 501 and is in an initial state (the small spring 6024 is neither stretched nor compressed).

[0075] Combination Figure 1 , Figure 2 , Figure 8 and Fig. 9 According to an embodiment of the present invention, the rotation drive assembly 7 includes a second motor mounting seat 701, a second motor 702, a hollow ball spline shaft 703, a first pulley 704, a belt 705, a second pulley 706, a ball spline seat 707 and a second coupling 708.

[0076] The second motor 702 is fixed on the fixed mounting seat 2, and the ball spline seat 707 is rotatably mounted in the fixed mounting seat 2. The second motor 702 is used to drive the ball spline seat 707 to rotate.

[0077] Specifically, the second motor 702 is fixed on the second motor mounting seat 701 , and the second motor mounting seat 701 is fixed on the fixed mounting seat 2 , thereby fixing the second motor 702 on the fixed mounting seat 2 .

[0078] The output shaft of the second motor 702 is connected to the first belt pulley 704 , the ball spline seat 707 fixes the second belt pulley 706 , and a belt 705 is arranged around the first belt pulley 704 and the second belt pulley 706 .

[0079] When the second motor 702 drives the first pulley 704 to rotate, the belt 705 drives the second pulley 706 to rotate, and the second pulley 706 drives the ball spline seat 707 to rotate.

[0080] like Figure 8 and Fig. 9 As shown, the hollow ball spline shaft 703 is installed in the ball spline seat 707, and the ball spline seat 707 is rotatably installed in the fixed mounting seat 2. The hollow ball spline shaft 703 is configured to reciprocate in the vertical direction relative to the ball spline seat 707, and the ball spline seat 707 rotates to drive the hollow ball spline shaft 703 to rotate.

[0081] Specifically, a first ball groove 7031 extending in the vertical direction is formed on the outer surface of the hollow ball spline shaft 703 , and a second ball groove 7071 extending in the vertical direction is formed on the inner surface of the ball spline seat 707 .

[0082] The balls 7072 are installed in the first ball groove 7031 and the second ball groove 7071, so that the hollow ball spline shaft 703 reciprocates in the vertical direction relative to the ball spline seat 707, and the hollow ball spline shaft 703 is driven to rotate when the ball spline seat 707 rotates.

[0083] Back to Figure 1 and Figure 2 The hollow ball spline shaft 703 passes through the fixed mounting seat 2 and the primary slide 701 and is connected to the hollow rotating shaft 504 .

[0084] When the ball spline seat 707 rotates to drive the hollow ball spline shaft 703 to rotate, the hollow ball spline shaft 703 drives the hollow rotating shaft 705 and the suction head 8 to rotate, thereby adjusting the angle of the suction head 8.

[0085] Furthermore, an exhaust port 704 is installed on the top of the hollow ball spline shaft 703 for connecting a vacuum generator. The vacuum generator is used to draw a vacuum, and the suction head 8 is vacuumed through the hollow ball spline shaft 703 and the hollow rotating shaft 504, so that the suction head 8 adsorbs the chip.

[0086] Furthermore, the bottom of the hollow ball spline shaft 703 is connected to the hollow rotating shaft 504 via a second coupling 708 .

[0087] Combine the following Figures 1 to 9 , the chip picking and chip mounting process of a pressure-controllable chip mounting head of the present invention is described.

[0088] Chip picking.

[0089] When picking up a chip, the first motor 302 drives the ball screw shaft 303 to rotate, and the ball screw shaft 303 drives the ball screw seat 304 to move downward in the vertical direction, thereby driving the first slide 401 to move downward in the vertical direction, and the slider 403 moves downward along the slide rail 402 to guide the first slide 401.

[0090] During the downward movement of the primary slide 401 in the vertical direction, the primary slide 401 drives the spring guide column 6021 to move downward in the vertical direction, the spring guide column 6021 transmits force to the limit nut 6025, the limit nut 6025 transmits force to the large spring 6022, the large spring 6022 transmits force to the limit sleeve 6023, the limit sleeve 6023 transmits force to the small spring 6024, and the small spring 6024 transmits force to the secondary slide 501, so that the secondary slide 501 moves downward in the vertical direction driven by the primary slide 401. In this process, the slight up and down sliding of the secondary slide 501 relative to the primary slide 401 is guided by the cross roller guide 502.

[0091] When the secondary slide 501 moves downward in the vertical direction driven by the primary slide 401, it drives the suction head 8, the hollow shaft 504, the second coupling 708, the hollow ball spline shaft 703 and the air extraction interface 704 to move downward in the vertical direction synchronously. When the hollow ball spline shaft 703 moves downward in the vertical direction, it generates relative motion with the ball spline seat 707.

[0092] When the suction head 8 contacts the chip, the secondary slide 501 stops moving downward in the vertical direction. At this time, the tension spring 601 is in a stretched state, the large spring 6022 is in an initial state (the large spring 6022 is neither stretched nor compressed), and the small spring 6024 is in an initial state (the small spring 6024 is neither stretched nor compressed).

[0093] At this time, the tension spring 601 is in a stretched state, suspending the secondary slide 501 under the primary slide 401. The tension of the tension spring 601 offsets the overall gravity of the suction head 8, the hollow rotating shaft 504, the secondary slide 501, the second coupling 708, the hollow ball spline shaft 703 and the vacuum interface 704, and the chip is not subjected to force (does not bear the pressure of the suction head 8).

[0094] The primary slide 401 continues to move downward in the vertical direction. Since the suction head 8 abuts against the chip, the secondary slide 501 cannot continue to move downward in the vertical direction. The primary slide 401 and the secondary slide 501 produce relative motion. In this process, the relative motion of the primary slide 401 and the secondary slide 501 is guided by the cross roller guide 502.

[0095] As the primary slide 401 continues to move downward in the vertical direction, the stretching amount of the tension spring 601 is shortened, the spring guide column 6021 transfers the force to the limit nut 6025, the limit nut 6025 transfers the force to the large spring 6022, the large spring 6022 transfers the force to the limit sleeve 6023, and the limit sleeve 6023 transfers the force to the small spring 6024.

[0096] Since the elastic coefficient of the small spring 6024 is much smaller than the elastic coefficient of the large spring 6022, the small spring 6024 located between the limiting sleeve 6023 and the secondary slide 501 (the upper surface of the secondary slide 501) begins to compress first.

[0097] The reading head 503 reads the reading of the grating ruler 404 and calculates the relative displacement between the primary slide 401 and the secondary slide 501, that is, the compression amount of the small spring 6024. At this time, the shortening amount of the tension spring 601 is equal to the compression amount of the small spring 6024.

[0098] The pressure N1 of the small spring 6024 and the tension N2 of the extension spring 601 are calculated by Hooke's law. Finally, the pressure N generated by the suction head 8 on the chip is calculated by the following method:

[0099] The suction head 8 exerts a pressure N on the chip = the pressure N1 of the small spring 6024 + the gravity G - the tension N2 of the tension spring 601 .

[0100] The gravity G is the overall gravity of the suction head 8 , the hollow rotating shaft 504 , the secondary slide 501 , the second coupling 708 , the hollow ball spline shaft 703 and the air extraction interface 704 .

[0101] When the pressure N generated by the suction head 8 on the chip reaches a certain value, the vacuum generator evacuates the exhaust interface 704, and evacuates the suction head 8 through the hollow ball spline shaft 703 and the hollow channel inside the hollow shaft 504, so that the suction head 8 adsorbs the chip.

[0102] Chip mounting.

[0103] After the suction head 8 adsorbs the chip, the first motor 302 drives the ball screw shaft 303 to rotate, and the ball screw shaft 303 drives the ball screw seat 304 to move upward in the vertical direction, thereby driving the primary slide 401 to move upward in the vertical direction.

[0104] When the primary slide 401 moves upward in the vertical direction, the primary slide 401 drives the secondary slide 501 to move upward in the vertical direction through the tension spring 601 and the tension spring 601.

[0105] When the secondary slide 501 moves upward in the vertical direction driven by the primary slide 401, it drives the suction head 8, the hollow rotating shaft 504, the second coupling 708, the hollow ball spline shaft 703 and the vacuum interface 704 to move upward in the vertical direction synchronously, so that the chip leaves the working surface where the chip is placed.

[0106] The chip mounting head is transferred as a whole to the upper side of the chip mounting work surface, the second motor 702 drives the first pulley 704 to rotate, the belt 705 drives the second pulley 706 to rotate, and the second pulley 706 drives the ball spline seat 707 to rotate.

[0107] The rotation of the ball spline seat 707 drives the hollow ball spline shaft 703 to rotate, and the hollow ball spline shaft 703 drives the hollow rotating shaft 705 and the suction head 8 to rotate, thereby adjusting the angle of the suction head 8 and the angle of the chip adsorbed by the suction head 8.

[0108] The first motor 302 drives the ball screw shaft 303 to rotate, and the ball screw shaft 303 drives the ball screw seat 304 to move downward in the vertical direction, thereby driving the primary slide 401 to move downward in the vertical direction.

[0109] During the downward movement of the primary slide 401 in the vertical direction, the primary slide 401 drives the spring guide column 6021 to move downward in the vertical direction, the spring guide column 6021 transfers the force to the limit nut 6025, the limit nut 6025 transfers the force to the large spring 6022, the large spring 6022 transfers the force to the limit sleeve 6023, the limit sleeve 6023 transfers the force to the small spring 6024, the small spring 6024 transfers the force to the secondary slide 501, thereby causing the secondary slide 501 to move downward in the vertical direction driven by the primary slide 401.

[0110] When the secondary slide 501 moves downward in the vertical direction driven by the primary slide 401, it drives the suction head 8, the hollow rotating shaft 504, the second coupling 708, the hollow ball spline shaft 703 and the air extraction interface 704 to move downward in the vertical direction synchronously.

[0111] When the chip adsorbed by the suction head 8 contacts the product to be mounted (such as a PCB board), the secondary slide 501 stops moving downward in the vertical direction. At this time, the tension spring 601 is in a stretched state, the large spring 6022 is in an initial state (the large spring 6022 is neither stretched nor compressed), and the small spring 6024 is in an initial state (the small spring 6024 is neither stretched nor compressed).

[0112] At this time, the stretch spring 601 is in a stretched state, suspending the secondary slide 501 under the primary slide 401. The tension of the stretch spring 601 offsets the overall gravity of the suction head 8, the hollow rotating shaft 504, the secondary slide 501, the second coupling 708, the hollow ball spline shaft 703 and the vacuum interface 704. The chip adsorbed by the suction head 8 does not generate pressure on the product to be mounted (such as a PCB board).

[0113] The first slide 401 continues to move downward in the vertical direction. Since the chip adsorbed by the suction head 8 abuts against the product to be mounted (such as a PCB board), the second slide 501 cannot continue to move downward in the vertical direction, and the first slide 401 and the second slide 501 produce relative movement.

[0114] As the primary slide 401 continues to move downward in the vertical direction, the stretching amount of the tension spring 601 is shortened, the spring guide column 6021 transfers the force to the limit nut 6025, the limit nut 6025 transfers the force to the large spring 6022, the large spring 6022 transfers the force to the limit sleeve 6023, the limit sleeve 6023 transfers the force to the small spring 6024, and the small spring 6024 located between the limit sleeve 6023 and the secondary slide 501 (the upper surface of the secondary slide 501) begins to compress first.

[0115] Since the elastic coefficient of the small spring 6024 is much smaller than the elastic coefficient of the large spring 6022, the small spring 6024 located between the limiting sleeve 6023 and the secondary slide 501 (the upper surface of the secondary slide 501) begins to compress first.

[0116] When the compression amount of the small spring 6024 reaches the limit compression amount (the small spring 6024 stops compressing), the large spring 6022 located between the limiting nut 6025 and the limiting sleeve 6023 starts to compress.

[0117] The reading head 503 reads the reading of the grating ruler 404 and calculates the relative displacement between the primary slide 401 and the secondary slide 501, that is, the limit compression of the small spring 6024 + the compression of the large spring 6022. At this time, the shortening amount of the tension spring 601 is equal to the limit compression amount of the small spring 6024 + the compression amount of the large spring 6022.

[0118] The pressure N1' of the limit compression of the small spring 6024, the pressure N3 of the large spring 6022, and the tension N2' of the extension spring 601 are calculated by Hooke's law. Finally, the pressure N' (i.e., mounting force) generated by the chip adsorbed by the suction head 8 on the product to be mounted (e.g., PCB board) is calculated by the following method:

[0119] The mounting force N'=the pressure N1' of the limit compression of the small spring 6024+the pressure N3 of the large spring 6022+the gravity G-the tension N2' of the tension spring 601.

[0120] The gravity G is the overall gravity of the suction head 8 , the hollow rotating shaft 504 , the secondary slide 501 , the second coupling 708 , the hollow ball spline shaft 703 and the air extraction interface 704 .

[0121] The present invention fixes a grating ruler 404 on a primary slide 401, fixes a reading head 503 on a secondary slide 501 at a position corresponding to the grating ruler, and installs a spring assembly 6 between the primary slide 401 and the secondary slide 501. The reading head reads the elongation of the tension spring 601 and the compression of the large spring 6022 and the small spring 6024, thereby obtaining the pressure of the suction head 8 on the chip, and then controlling the pressure of the chip. The pressure control is easy and the technical threshold is low. The overall structure of the chip mounting head is small and the cost is low. The routing of the chip mounting head is more convenient, and low-cost precise pressure control is achieved.

[0122] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A pressure-controllable chip placement head, characterized in that: The chip placement head at least includes a fixed mounting seat, a vertical drive assembly, a primary sliding assembly and a secondary sliding assembly; The vertical drive assembly is mounted on the fixed mounting seat; the primary sliding assembly comprises at least a primary sliding platform; The vertical driving assembly is connected to the primary slide of the primary sliding assembly, and is used to drive the primary slide to reciprocate in the vertical direction; The secondary sliding assembly at least comprises a secondary slide; a hollow rotating shaft is rotatably installed in the secondary slide along the vertical direction, and a suction head is fixed at the bottom of the hollow rotating shaft; Wherein, a spring assembly is installed between the primary slide and the secondary slide; a grating ruler is fixed on the primary slide, and a reading head is fixed on the secondary slide corresponding to the position of the grating ruler; Wherein, the spring assembly includes a tension spring, one end of which is fixed to the primary slide, and the other end of which is fixed to the secondary slide, so that the secondary slide is suspended below the primary slide and the secondary slide is free to move in a vertical direction relative to the primary slide; Wherein, the spring assembly further comprises an adjusting spring assembly, the adjusting spring assembly comprises a spring guide column, the top of the spring guide column is fixed to the primary slide, and the bottom of the spring guide column is inserted into the secondary slide in a sliding manner; Wherein, a limiting nut and a limiting sleeve are fixed on the spring guide column, and the limiting sleeve is located below the limiting nut; a large spring is sleeved on the spring guide column, and the large spring is located between the limiting nut and the limiting sleeve; A small spring is sleeved on the spring guide column, and the small spring is located between the limiting sleeve and the secondary slide.

2. The chip placement head according to claim 1, characterized in that: The vertical drive assembly includes a first motor, a ball screw shaft and a ball screw seat; The first motor is fixed on the fixed mounting seat, and the ball screw shaft is connected to the output shaft of the first motor; the ball screw seat is fixed to the primary slide, and the ball screw shaft is installed in the ball screw seat and passes through the primary slide; When the first motor drives the ball screw shaft to rotate, the ball screw shaft drives the ball screw seat to reciprocate in the vertical direction, thereby driving the primary slide to reciprocate in the vertical direction.

3. The chip placement head according to claim 2, characterized in that: The vertical drive assembly also includes a first motor mounting seat, the first motor is fixed on the first motor mounting seat, and the first motor mounting seat is fixed on the fixed mounting seat.

4. The chip placement head according to claim 2, characterized in that: The output shaft of the first motor is connected to the ball screw shaft through a first coupling.

5. The chip placement head according to claim 1, characterized in that: The primary sliding assembly also includes a slide rail and a slider; The slider is fixed to the primary slide, the slide rail is fixed to the fixed mounting seat, and the slider is slidably connected to the slide rail; When the primary slide table reciprocates along the vertical direction, the slider reciprocates along the slide rail.

6. The chip placement head according to claim 1, characterized in that: A cross roller guide is installed between the primary slide and the secondary slide.

7. The chip placement head according to claim 1, characterized in that: The chip placement head also includes a rotation drive assembly; The rotary drive assembly includes a second motor, a hollow ball spline shaft and a ball spline seat; The second motor is fixed on the fixed mounting seat, and the ball spline seat is rotatably mounted in the fixed mounting seat; the second motor is used to drive the ball spline seat to rotate; The hollow ball spline shaft is installed in the ball spline seat, and the hollow ball spline shaft is configured to reciprocate in a vertical direction relative to the ball spline seat, and the hollow ball spline shaft is driven to rotate when the ball spline seat rotates; The hollow ball spline shaft passes through the fixed mounting seat and the primary slide, and is connected to the hollow rotating shaft; When the ball spline seat rotates and drives the hollow ball spline shaft to rotate, the hollow ball spline shaft drives the hollow rotating shaft and the suction head to rotate.

8. The chip placement head according to claim 7, characterized in that: The outer surface of the hollow ball spline shaft is provided with a first ball groove extending in the vertical direction, and the inner surface of the ball spline seat is provided with a second ball groove extending in the vertical direction; Balls are installed in the first ball groove and the second ball groove, so that the hollow ball spline shaft reciprocates relative to the ball spline seat in a vertical direction, and the hollow ball spline shaft is driven to rotate when the ball spline seat rotates.

9. The chip placement head according to claim 7, characterized in that: The rotary drive assembly further comprises a second motor mounting seat, the second motor is fixed on the second motor mounting seat, and the second motor mounting seat is fixed on the fixed mounting seat; The output shaft of the second motor is connected to the first pulley, and the ball spline seat fixes the second pulley; a belt is arranged around the first pulley and the second pulley; When the second motor drives the first pulley to rotate, the second pulley drives the ball spline seat to rotate.

10. The chip placement head according to claim 7, characterized in that: An air extraction interface is installed on the top of the hollow ball spline shaft; The bottom of the hollow ball spline shaft is connected to the hollow rotating shaft through a second coupling.

Images