Electric Picker Actuator Using Polygonal Guide

Abstract

The present invention relates to an electric picker actuator used for precisely picking up small components such as electronic components or semiconductor chips. More specifically, the invention relates to an electric picker actuator capable of realizing high speed, high precision, high rigidity, and long lifespan by applying a picker capable of linear motion, a polygonal ball guide (PBG) that guides the picker, and a linear motor including a square coil with high efficiency and minimized losses.

Description

Technology Field

[0001] The present invention relates to an electric picker actuator used for precisely picking up small components such as electronic components or semiconductor chips. More specifically, the invention relates to an electric picker actuator capable of realizing high speed, high precision, high rigidity, and long lifespan by applying a picker capable of linear motion, a polygonal ball guide (PBG) that guides the picker, and a linear motor including a square coil with high efficiency and minimized losses. Background Technology

[0002] Electric picker actuators are key components used to precisely pick up and move small parts in semiconductor equipment, electronic component assembly equipment, and the like. Generally, these actuators must be capable of high-speed and high-precision position control and stable torque control, and must maintain high durability and reliability in repetitive operating environments. To meet these requirements, conventional picker actuators are constructed with a structure that combines linear motion guide systems, such as LM guides (Linear Motion Guides), keyways, or ball splines, with linear motors, voice coil motors (VCMs), or pneumatic air cylinders.

[0003] However, these conventional structures exhibit various problems due to structural limitations. For example, when using LM guides or ball splines, minute vibrations may occur within the stroke, straightness may be poor, and the lifespan is shortened due to wear caused by repetitive motion. In particular, the sliding type has a higher coefficient of friction and lower durability compared to the rolling type, making it unsuitable for long-term operation. Furthermore, when a small torque or external force is applied, the precision of position control is reduced due to the moment generated in the guide section, and unnecessary three-degree-of-freedom motions such as pitching, rolling, and yawing occur, which can degrade overall performance. Additionally, when applied to pneumatic air cylinders, there are problems with speed control and multi-position control.

[0004] Furthermore, coil structures using conventional linear motors mostly feature a circular cross-section, resulting in low space utilization and limited power density; consequently, it is difficult to simultaneously achieve miniaturization and high output. Accordingly, conventional technology has limitations in various aspects such as precision, rigidity, lifespan, and efficiency, and structural alternatives are required to overcome these challenges. The problem to be solved

[0005] The present invention was devised to solve the above-mentioned problems, and the objective of the present invention is to improve the various problems arising from guide methods such as LM guides, sliding guides, and ball splines, and driving methods using pneumatic air cylinders, which are used in conventional electric picker actuators for precisely picking up small components such as electronic components or semiconductor chips.

[0006] More specifically, the purpose is to improve the problem of shaking and reduced straightness that occurs during pickup operation, solve the problem of reduced positional accuracy caused by moments generated by external forces, suppress the problem of excessive 3-degree-of-freedom oscillation such as pitching, rolling, and yawing of the linear guide, improve the problem of shortened guide life caused by friction and wear, compensate for the instability of rotational direction control caused by external minute torque, overcome the limitations of existing electric coil structures that lack space efficiency and structural stability, and solve the problem of difficulty in speed control and multi-position control when using pneumatic air cylinders.

[0007] As described above, the present invention aims to solve existing problems by providing an improved method that enables the precision, durability, stability, speed control, position control, and multi-position control required for a pickup system. means of solving the problem

[0008] An electric picker actuator according to one embodiment of the present invention comprises a polygonal guide for guiding the linear movement of a picker and a picker including a guide post movable in the vertical direction within the polygonal guide, wherein the guide comprises a guide housing, a through hole penetrating the guide housing to allow the guide post to move vertically, and a plurality of balls disposed between the inner surface of the through hole and the outer surface of the guide post to minimize friction and improve straightness during the linear movement of the guide post.

[0009] In addition, the guide post and the through hole have a polygonal cross-section, and the plurality of balls are disposed on the inner surface of each polygonal through hole.

[0010] In addition, the ball is composed of a plurality of balls spaced apart at regular intervals to suppress shaking of the guide post by being positioned in a point contact state with the outer surface of the guide post.

[0011] In addition, the ball receiving hole, which accommodates a plurality of the balls, is formed through the inner surface to the outer surface of the through hole.

[0012] Additionally, the guide includes a ball cage provided on the inner surface of each of the through holes, having a plurality of ball grooves formed therein to accommodate each of the plurality of balls, thereby enabling alignment and free rolling between the balls.

[0013] In addition, the above-mentioned picker includes an internal pneumatic passage and is equipped with a suction part at the bottom capable of adsorbing an object, and the pneumatic passage is connected to a pneumatic part that receives pneumatic pressure from a pneumatic supply means to receive pneumatic pressure or vacuum.

[0014] In addition, the electric picker actuator includes a linear motor that is the driving source for the linear motion of the picker, and the linear motor includes a permanent magnet and a coil, and the coil moves linearly in the up and down direction when power is supplied.

[0015] In addition, the coil is a square coil with a rectangular or square cross-section.

[0016] In addition, the through hole and the guide post are characterized by having a square or hexagonal cross-sectional shape. Effects of the invention

[0017] The electric picker actuator using the polygonal guide of the present invention, configured as described above, has the effect of suppressing shaking and rotation in the X and Y directions, excluding the Z-axis which is the driving direction of the picker, and securing high rigidity through the combination of a polygonal structured post, an outer casing, and a multi-row arranged ball cage.

[0018] In addition, due to point contact between the ball and the rolling surface, friction loss is low, and stable high-speed operation is possible.

[0019] In addition, through a structure with a low coefficient of friction and a ball cage design with strong durability, it is possible to achieve a lifespan more than three times longer than that of conventional guides.

[0020] In addition, the adoption of a coaxial alignment structure and polygonal linear bearings minimizes rotational direction errors and improves position control precision.

[0021] In addition, it is possible to design a structure with minimized external dimensions, which reduces the impact on surrounding devices and improves the energy efficiency of the entire system.

[0022] In addition, by applying a square coil structure that improves density by more than 50% compared to conventional circular coils, it is possible to achieve higher output in the same space.

[0023] In addition, it has the effect of being applicable to high-performance precision processes, as it enables repeatability of ±0.5㎛ or less, acceleration of up to 10G, and high-speed movement of 1,000mm / sec. Brief explanation of the drawing

[0024] FIG. 1 is a front perspective view of an electric picker actuator using a polygonal guide and a linear motor according to an embodiment of the present invention. FIG. 2 is a front view of the actuator of the present invention. FIG. 3 is a perspective view of a picker assembly showing the combined structure of the polygonal guide and the picker of the present invention. FIG. 4 is a longitudinal cross-sectional view of a picker assembly illustrating the combined structure of the polygonal guide and the picker of the present invention. FIG. 5 is a cross-sectional view of a picker assembly showing the combined structure of the polygonal guide and the picker of the present invention. FIG. 6 is a partially enlarged perspective view comparing a conventional linear coil and a polyhedral coil of the present invention. Specific details for implementing the invention

[0025] Hereinafter, an embodiment of the present invention as described above will be explained in detail with reference to the drawings.

[0026] FIG. 1 shows a front view of an electric picker actuator (1000) using a polygonal guide (300) according to an embodiment of the present invention.

[0027] As described, the electric picker actuator (1000) comprises a body (100), a linear motor (actuator) (200), a picker assembly (500) including a polygonal guide (300) and a picker (400), and a pneumatic part (600).

[0028] The body (100) is configured to accommodate or combine a linear motor (200), a picker assembly (500), and a pneumatic part (600) on the housing.

[0029] The linear motor (200) may be an electric actuator requiring precise control that induces linear reciprocating motion of the picker (400) by utilizing the interaction between a permanent magnet and a coil.

[0030] The polygonal guide (300) is configured to guide the up and down Z direction movement of the picker (400) and is described in detail below with reference to the drawings.

[0031] The picker (400) is connected to the coil of the linear motor (200) and configured to move in the up and down direction in conjunction with the up and down movement of the coil. A suction part (420) is formed at the bottom so that it can suction an object by the pneumatic pressure of the pneumatic part (600). Additionally, the picker (400) is configured to be fitted into a polygonal guide (300) to guide its up and down movement, and will be described in detail below with reference to the drawings.

[0032] The pneumatic section (600) is configured to transmit pneumatic pressure to the picker (400) through a pneumatic supply means (not shown) and is provided on the body (100), and is configured to include a pneumatic connector (610) connected to the pneumatic supply means and a pneumatic transmission pipe (620) that transmits pneumatic pressure by connecting the pneumatic connector (610) to a pneumatic flow path (412).

[0033] FIG. 2 shows a front view of the linear motor (200) of the present invention. As shown, the linear motor (200) is configured to include a permanent magnet (210), a square coil (220), a coil housing (230), and a guide post connector (240).

[0034] The permanent magnet (210) is a component that forms a magnetic field to generate driving force for the square coil (220), and is formed of a material capable of stably generating a constant magnetic flux (e.g., NdFeB magnet, etc.). In this embodiment, the permanent magnet (210) acts as a stator and interacts with the square coil (220) to induce linear motion of the square coil (220).

[0035] The square coil (220) is formed in a precise square or rectangular shape instead of a conventional circular coil, thereby increasing space utilization and improving magnetic flux density. In particular, by applying a square coil (220) having a square or rectangular cross-section, a coil density of approximately 50% or more compared to a conventional circular coil can be secured, thereby enabling higher output and response speed within the same space. The square coil (220) is housed in a coil housing (230), and the coil housing (230) is coupled to the body (100) to enable vertical linear movement. Additionally, the coil housing (230) is firmly coupled to the picker (400) through a guide post connector (240), so that the movement of the square coil (220) is directly transmitted to the linear movement of the picker (400) through the coil housing (230). The square coil (220) generates a driving force in a linear direction (Z-axis) through interaction with the permanent magnet (210) when current is applied. The coil housing (230) supports the square coil in a fixed manner and performs the role of structurally ensuring stability so that the generated driving force is effectively transmitted to the picker (400).

[0036] Meanwhile, when current is applied to the square coil (220) during driving, it moves in a straight direction within the magnetic field of the permanent magnet (210) due to the Lorentz force, and this movement becomes the driving operation of the linear motor (200). Accordingly, the linear motor (200) can achieve precise linear driving without complex mechanical links or gears.

[0037] In addition, the power connection unit (250, see FIG. 1) is a connection unit for receiving electrical signals and current from an external controller or power supply unit, and performs the role of stably supplying current to the square coil (220). The power connection unit (250) is designed to be connected to a control board or driver module so as to drive the square coil (220) according to operation commands.

[0038] The linear motor (200) of the present invention as described above provides high output and high responsiveness with a simple structure and can be applied to small precision devices requiring precise position control (e.g., semiconductor equipment, medical equipment, precision assembly equipment, etc.). In addition, through the high-density arrangement of square coils (220) and the precise alignment structure with the permanent magnet (210), unnecessary vibration or heat generation that may occur during operation is suppressed, and high-efficiency, low-noise operation is possible.

[0039] FIG. 3 shows a perspective view of a picker assembly (500) in which the combined structure of the polygonal guide (300) and the picker (400) of the present invention is shown, and FIG. 4 shows a cross-sectional view (cross-sectional view AA' of FIG. 3) of a picker assembly (500) in which the combined structure of the polygonal guide (300) and the picker (400) of the present invention is shown.

[0040] As described, the picker assembly (500) is configured so that the picker (400) can move precisely in a straight up and down direction within a polygonal guide (300), which is a fixed guide structure, and has a structure for accurately picking up and moving small parts.

[0041] The polygonal guide (300) performs the function of guiding the movement of the picker (400) and supporting it so that it can move up and down in a straight line without shaking, and its composition includes a guide housing (310), a polygonal through hole (320), a polygonal ball cage (340), and a plurality of balls (350).

[0042] The guide housing (310) is a main body forming the entire guide structure and is formed of a durable metal or high-strength synthetic resin, and the polygonal through-hole (320) formed in the guide housing (310) has a cross-section that is, for example, square or hexagonal in shape. This polygonal through-hole (320) suppresses the rotation of the picker (400), which is formed with a shape corresponding to the cross-section of the polygonal through-hole (320), while simultaneously providing structural stability in which the bearing is evenly supported.

[0043] A polygonal through-hole (320) is formed in the center of the guide housing (310) to allow the picker (400) to move in the up and down direction. The polygonal through-hole (320) is machined with a precise tolerance so as not to be excessively loose while minimizing interference with the guide post (410).

[0044] Additionally, a polygonal ball cage (340) in the shape of a polygonal frame is provided inside the polygonal through hole (320), and a plurality of balls (350) are arranged inside. The balls (350) minimize friction by making point contact with the outer surface of the guide post (410) and suppress three-degree-of-freedom movements such as pitching, rolling, and yawing that may occur during vertical movement, thereby improving the straightness of the guide post (410). Therefore, the guide post (410) is capable of stable and accurate linear movement.

[0045] The picker (400) is a component that actually adsorbs and moves an object, and includes a guide post (410) and an adsorption part (420). The guide post (410) is formed in a polygon corresponding to the polygonal through hole (320) so that it is inserted into the polygonal through hole (320) of the guide housing (310) and moves linearly in the up and down direction, and its outer surface is mirror-finished or coated to ensure contact with the ball (350) inside the polygonal through hole (320). A pneumatic transmission pipe (411) for pneumatic supply is formed at the top of the guide post (410) and is connected to an external pneumatic part (600) to receive pneumatic pressure according to a control signal.

[0046] A pneumatic channel (412) is formed inside the guide post (410) along the vertical length direction, and this channel is connected from a pneumatic transmission pipe (411) located on the upper side of the picker (400) to a suction part (420) located on the lower side. The suction part (420) is provided at the bottom of the guide post (410) and functions to perform vacuum suction by adhering to the surface of the target part.

[0047] The adsorption part (420) has an adsorption channel (421) formed therein, which is connected to a pneumatic channel (412) and performs the operation of adsorbing or releasing an object according to the pneumatic pressure or vacuum provided from the pneumatic part (600). The adsorption part may be composed of a rubber pad or a silicone material and can flexibly accommodate electronic components and semiconductor chips of various shapes.

[0048] The picker assembly (500) of the present invention can simultaneously achieve high-precision linear motion, rotation suppression function, and improved durability that go beyond a simple linear guide by adopting a polygonal guide structure, and can be applied to various industrial fields such as small precision devices, semiconductor packaging, and high-speed assembly lines.

[0049] Meanwhile, the picker (400) is mechanically connected to a coil housing (230) that accommodates a square coil (220) via a guide post connector (240), and a connecting member such as a bracket, a connecting block, or a fixing pin may be used as the means of connection. This connecting structure is precisely fastened so that the picker (400) can move linearly in the up-and-down direction as a whole, directly linked to the operation of the coil (220).

[0050] The picker (400) is firmly connected to the lower or one side of the coil housing (230), and the guide post connector (240) is selected and applied with a material and shape to maintain constant tension or mechanical strength. The connection structure using the guide post connector (240) is precisely fastened so that no relative shaking or play occurs between the coil housing (230) and the guide post (410), and a positioning pin or guide pin may also be provided to prevent alignment errors during assembly.

[0051] Due to this structure, when current is applied to the square coil (220) and it moves in a straight line upward or downward, the movement is transmitted directly to the picker (400) through the guide post connector (240) connected to the coil housing (230), and as a result, the picker (400) moves in the up and down direction in precise synchronization with the movement of the square coil (220).

[0052] That is, the linear motor (200) of the present invention is configured so that the picker (400) moves directly in a linear motion through the driving of the square coil (220), thereby enabling fast and precise picker operation without mechanical links or reduction gears. In particular, this configuration is designed to maintain positional accuracy even during high-speed operation, so that precise picking and transfer of objects can be performed repeatedly.

[0053] This interlocking structure is one of the key elements for improving the response speed and control precision of the electric picker actuator (1000) of the present invention, and because the energy transfer path between the linear motor (200) and the picker (400) is simple and linear, the efficiency and stability of operation are also greatly improved. In addition, while using a pneumatic air cylinder causes difficulties in speed control and multi-position control, the above problems can be solved by using an electric picker actuator (1000) using a linear motor (200).

[0054] In addition, since the picker (400) is positioned within the polygonal guide (300), the linear motion generated by the driving of the square coil (220) is assisted by the polygonal guide (300), thereby maximizing straightness and vibration suppression performance. This provides a very advantageous effect in semiconductor equipment or micro-assembly lines handling high-precision parts.

[0055] FIG. 5 shows a cross-sectional view (BB' cross-sectional view of FIG. 3) illustrating the combined structure of the polygonal guide (300) and the picker (400) of the present invention.

[0056] As described, the picker assembly (500) includes a guide housing (310) and a polygonal guide post (410) slidably accommodated therein, and is equipped with a precision guide structure to guide the linear movement of the guide post (410) through a polygonal through hole (320) and to suppress shaking.

[0057] The polygonal guide (300) includes a guide housing (310) that forms the outer perimeter of the entire structure and a polygonal through hole (320) that penetrates the center of the guide housing (310) in the longitudinal direction, and the through hole (320) is formed with a polygonal cross-sectional shape such as a square or a hexagon. This polygonal shape performs the function of mechanically suppressing the rotation of the polygonal guide post (410) and provides a structural basis that enables high-precision linear motion.

[0058] A polygonal ball cage (340) having a cross-section in the shape of a polygonal frame (square frame) is disposed on the inner surface of the polygonal through hole (320) along the outer surface of the guide post (410), and a plurality of balls (350) are inserted into the ball receiving hole (341) of the polygonal ball cage (340). The plurality of balls (350) are interposed between the outer surface of the guide post (410) and the through hole (320) through the polygonal ball cage (340), thereby inducing rolling motion when the guide post (410) moves up and down, significantly reducing friction, and ensuring straightness. That is, the plurality of balls (350) can be evenly distributed and disposed on each side of the guide post (410) through the polygonal ball cage (340).

[0059] Each ball (350) is positioned in point contact with the inner surface of the through hole (320) and the outer surface of the guide post (410), thereby effectively suppressing three-degree-of-freedom shaking such as pitching, rolling, and yawing that may occur during the linear movement of the guide post (410). In addition, the degree of shaking of the picker (400) is also improved by designing it so that a preload of several microns is applied consistently.

[0060] Meanwhile, as a plurality of balls (350) are used, a structure is additionally provided to prevent the balls (350) from being ejected from the polygonal ball cage (340) due to external impact or vibration. Specifically, the polygonal ball cage (340) has a ball receiving hole (341) formed therein for receiving the balls (350), and an anti-ejection projection (342) is formed at the outer or inner end of the ball receiving hole (341) to mechanically limit the balls (350) from protruding beyond a certain amount. The anti-ejection projection (342) protrudes a predetermined length radially inward from the circumference of the ball receiving hole (341).

[0061] Additionally, ball receiving holes (341) are arranged at regular intervals on the polygonal ball cage (340) so that each ball (350) can maintain a regular spacing and be aligned, which prevents collisions or alignment errors between the balls (350) and serves to improve the durability and lifespan of the entire bearing.

[0062] As a result, the picker assembly (500) of the present invention illustrated in FIG. 5 guides the picker (400) to move precisely up and down in a straight line within a polygonal guide (300), minimizes friction and ensures straightness through a plurality of balls (350), and at the same time maximizes reliability and durability through a non-detachment structure.

[0063] FIG. 6 is a partial enlarged perspective view comparing a conventional circular coil and a polyhedral coil of the present invention.

[0064] As shown in FIG. 6a, the conventional circular coil (22) has a problem in that the coil is wound in a circular cross-section, so the coil placement efficiency within a limited space is low and the space utilization inside the motor or actuator is poor.

[0065] First, due to the winding shape of circular coils, the effective area between adjacent coils is formed inefficiently, making it difficult to increase electrical density within the same volume. Consequently, the output density due to electromagnetic induction is low, and the magnetic field formation of the coil is dispersed, leading to a decrease in motor driving efficiency. Additionally, the curved cross-sectional structure results in lower relative alignment precision and carries the possibility of vibration during high-speed operation.

[0066] On the other hand, as illustrated in FIG. 6b, the square coil (220) according to the present invention is formed with a precise rectangular cross-section, thereby enabling a greater number of coil turns within the same space. This enables the maximization of coil occupancy and allows for a high density of substantially more than 50%. Consequently, a higher electromagnetic force can be generated in an actuator of the same size, and output and responsiveness are improved.

[0067] Since the square coil (220) ensures a uniform spacing between coils and facilitates alignment, the electromagnetic field distribution is uniform, and as a result, stable linear driving is possible. Additionally, because the outer shape of the square coil (220) is straight, fixing and coupling within the housing is easy, and the structural integrity and assembly of the entire device are improved.

[0068] Furthermore, the square coil (220) has a uniform heat distribution and excellent heat dissipation characteristics, so it can suppress temperature rise even during long-term operation, thereby increasing durability and reliability. This is a particularly advantageous characteristic for small actuators or semiconductor pickup devices that require precise control.

[0069] In conclusion, as can be clearly seen from FIG. 6, conventional circular coils have significant limitations in terms of space utilization and output, whereas the square coil of the present invention enables high-density design and high-efficiency driving, thereby improving the efficiency of the linear motor and dramatically improving the performance of the electric picker actuator.

[0070] The technical concept of the present invention should not be interpreted as being limited to the above-described embodiments. Not only is the scope of application diverse, but various modifications are possible at the level of a person skilled in the art without departing from the essence of the invention claimed in the claims. Accordingly, such improvements and modifications fall within the scope of protection of the present invention insofar as they are obvious to a person skilled in the art. Explanation of the symbols

[0071] 100 : Body 200 : Linear motor 210 : Permanent magnet 220 : Square coil 230 : Coil housing 240 : Guidepost Connector 250 : Power connector 300 : Polygon Guide 310 : Guide housing 320: Polygonal through-hole 340 : Polygonal ball cage 341: Ball receiving hall 342 : Anti-slip protrusion 350 : Ball 400 : Picker 410 : Guidepost 411: Pneumatic transmission pipe 412 : Pneumatic fluid path 420 : Adsorption part 421 : Adsorption channel 500 : Picker assembly 600 : Pneumatic section 610 : Pneumatic connector 620 : Pneumatic transmission pipe

Claims

Claim 1 An electric picker actuator using a polygonal guide, comprising a picker including a polygonal guide for guiding linear movement of the picker and a guide post movable in the up-and-down direction within the polygonal guide; wherein the guide includes a guide housing, a through hole penetrating the guide housing to allow the guide post to move up and down, and a plurality of balls disposed between the inner surface of the through hole and the outer surface of the guide post to minimize friction and improve straightness during linear movement of the guide post, and further includes a linear motor for driving the linear movement of the picker, wherein the linear motor includes a fixedly positioned permanent magnet and a square coil that moves linearly in the up-and-down direction when power is supplied, wherein the square coil has a cross-section formed as a rectangle or a square, wherein the square coil is accommodated in a coil housing, wherein the coil housing is coupled to the picker through a guide post connector, and wherein the linear movement of the square coil is transmitted to the up-and-down movement of the picker through the coil housing and the guide post connector. Claim 2 An electric picker actuator using a polygonal guide, wherein, in claim 1, the guide post and the through hole have a polygonal cross-section, and the plurality of balls are disposed on the inner surface of each polygonal through hole. Claim 3 An electric picker actuator using a polygonal guide, wherein the ball is arranged in a point contact state with the outer surface of the guide post and is composed of a plurality of balls spaced apart at regular intervals to suppress shaking of the guide post. Claim 4 In claim 2, the electric picker actuator using a polygonal guide, wherein the through hole is a ball receiving hole formed through the inner surface to the outer surface of the through hole for receiving a plurality of the balls. Claim 5 In claim 2, the electric picker actuator using a polygonal guide comprises a ball cage formed with a plurality of ball grooves that accommodate each of the plurality of balls, provided on the inner surface of each of the through holes, so as to enable alignment and free rolling between the balls. Claim 6 In claim 1, the picker includes a pneumatic fluid passage inside and is equipped with a suction part at the bottom capable of suctioning an object, and the pneumatic fluid passage is connected to a pneumatic part that receives pneumatic pressure from a pneumatic supply means and receives pneumatic pressure or vacuum, an electric picker actuator using a polygonal guide. Claim 7 delete Claim 8 delete Claim 9 delete

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