CN102130567A - Voice coil motor - Google Patents

Abstract

A voice coil motor relates to an ultra-precise motion positioning device. The present invention includes two upper and lower permanent magnet assemblies and one or two coil assemblies arranged between the upper and lower permanent magnet assemblies, and its technical feature is to increase the freedom of movement of the voice coil motor along the Y axis; When moving along the Y-axis direction, the effective coil area between the permanent magnet components remains unchanged, the resultant Lorentz force of the motor mover along the Y-axis direction is zero, and the Lorentz force along the X-axis direction remains unchanged. The present invention not only satisfies the movement requirement of the voice coil motor mover in the X direction, but at the same time, the motor mover can move along the Y axis for a long distance, which increases the working space of the motor and solves the problem of moving the mover in the existing voice coil motor structure. A problem with limited movement along the Y axis.

Description

A voice coil motor

technical field

The invention relates to an ultra-precise motion positioning device, in particular to a voice coil motor, which belongs to the field of semiconductor equipment.

Background technique

The ultra-precise micro-motion stage with nanometer-level motion positioning accuracy is one of the key components of semiconductor equipment, such as silicon wafer stages and mask stages in lithography machines. In order to meet the ultra-precise positioning requirements of the actuator, the voice coil motor supported by magnetic levitation constraint is widely used as an ultra-precise micro-motion stage. The Lorentz force generated by the energized coil in the air gap magnetic field of the permanent magnet array provides the driving force and suspension support, and the thrust of the execution unit is changed by controlling the current in the coil. It has the advantages of simple structure and easy application in a vacuum environment.

The current commonly used voice coil motor structure is shown in FIG. 1 , including a first coil assembly, a first permanent magnet assembly, and a second permanent magnet assembly. When the coil is energized, a Lorentz force will be generated, and the motor mover can move along the X-axis direction under the action of the Lorentz force. In the common structure, the length L of the first coil assembly along the Y direction is equal to the length of each permanent magnet assembly along the Y axis. When there is an installation error between each permanent magnet assembly and the first coil assembly along the Y direction, or the motor mover When moving along the Y-axis direction, the resultant force of the Lorentz force in the Y direction on the motor mover is not zero, so the motor mover will move in the Y direction due to the force along the Y direction, which affects the positioning accuracy of the voice coil motor, and at the same time The effective area between the first coil assembly and each permanent magnet changes, so the Lorentz force along the X-axis direction on the motor mover will also change, which is inconsistent with the design thrust and affects the thrust constant of the motor. Therefore, in the current structure of the voice coil motor, the movement of the mover along the Y-axis is restricted, and the working space is limited.

Contents of the invention

The purpose of the present invention is to provide a voice coil motor applied to semiconductor equipment, which not only meets the requirement of micro-movement of the motor mover in the X direction, but also solves the current problem that the mover of the voice coil motor is limited in the Y direction.

The first technical scheme of the present invention is as follows:

A voice coil motor, the voice coil motor includes two upper and lower permanent magnet assemblies and a coil assembly arranged between the upper and lower permanent magnet assemblies; each permanent magnet assembly includes two main permanent magnets and an iron yoke, the main The magnetization direction of the permanent magnets is along the Z-axis direction and arranged in a conventional array form. A closed magnetic field is formed between the permanent magnet components; the closed magnetic field passes through the effective surface of the coil component vertically, and the current direction is perpendicular to the magnetic field direction, generating Lorentz force to drive the motor. The motor moves along the X direction, and the feature is that the freedom of movement of the voice coil motor along the Y-axis direction is increased, that is, when the permanent magnet assembly is the mover, the length of the coil in the coil assembly parallel to the Y-axis along the Y-axis direction L2, greater than or equal to the sum of the length L of the permanent magnet assembly along the Y-axis direction and the moving distance L1 of the permanent magnet assembly along the Y-axis direction; when the coil assembly is used as a mover, the length L of the permanent magnet assembly along the Y-axis direction is greater than or equal to the coil assembly The sum of the length L2 of the coil parallel to the Y-axis along the Y-axis and the moving distance L3 of the coil assembly along the Y-axis.

Another technical solution of the present invention is as follows: a voice coil motor, the voice coil motor includes two upper and lower permanent magnet assemblies and one or two coil assemblies arranged between the upper and lower permanent magnet assemblies; The magnet assembly includes a main permanent magnet, an auxiliary permanent magnet and an iron yoke; the magnetization direction of the main permanent magnet is along the Z-axis direction, and the magnetization direction of the auxiliary permanent magnet is along the X-axis direction. Each permanent magnet assembly is arranged in the form of a Halbach array, and each permanent magnet A closed magnetic field is formed between the components; the closed magnetic field passes through the effective surface of the coil component vertically, the direction of the current is perpendicular to the direction of the magnetic field, and a Lorentz force is generated to drive the motor mover to move in the X direction, and the characteristic is that: when the permanent magnet component is the mover , the length L2 of the coil parallel to the Y-axis in the coil assembly along the Y-axis direction is greater than or equal to the sum of the length L of the permanent magnet assembly along the Y-axis direction and the moving distance L1 of the permanent magnet assembly along the Y-axis direction; when the coil assembly is used as a mover , the length L of the permanent magnet assembly along the Y-axis direction is greater than or equal to the sum of the length L2 of the coil in the coil assembly parallel to the Y-axis direction along the Y-axis direction and the moving distance L3 of the coil assembly along the Y-axis direction.

Compared with the prior art, the present invention has the following advantages and outstanding effects:

In the structure of the voice coil motor of the present invention, even if there is an installation error along the Y direction between each permanent magnet assembly and the coil assembly, or the motor mover moves along the Y axis due to an external force, the motor mover is subjected to a force along the Y axis. The resultant Lorentz force is always zero, and the effective coil area through which the magnetic field passes between the permanent magnet components remains unchanged, so the Lorentz force on the motor mover along the X-axis direction remains unchanged, which not only satisfies the requirements of the voice coil motor. The movement requirements of the micro-movement in the X direction, and the mover can move along the Y-axis for a long distance, which increases the freedom of movement of the motor in the Y direction, increases the working space of the motor, and solves the problem of the mover in the existing voice coil motor structure. Problems with limited movement in the Y-axis direction.

Description of drawings

Figure 1 is an axonometric view of a commonly used voice coil motor structure.

Figure 2 is a top view of a commonly used voice coil motor.

Fig. 3 is a structural axonometric view of the voice coil motor scheme 1 of the present invention.

Figure 4 is a top view of the structure of Scheme 1.

Fig. 5 is a cross-sectional view of the structure of Scheme 1 along plane A-A.

Fig. 6 is an axonometric view of the second structure of the voice coil motor scheme of the present invention.

Fig. 7 is a top view of the structure of the second scheme.

Fig. 8 is a sectional view of the structure of the second scheme along the B-B plane.

Fig. 9 is an axonometric view of the third structure of the voice coil motor scheme of the present invention.

Figure 10 is a top view of the structure of the third scheme.

Fig. 11 is a sectional view of the structure of Scheme 3 along plane C-C.

Figure 12 is a structural axonometric view of Scheme 4.

Fig. 13 is a top view of the structure of Scheme 4.

Fig. 14 is a top view of the structure of the fifth scheme.

Figure 15 is a structural axonometric view of Scheme 6.

Fig. 16 is a top view of the structure of Scheme 6.

In the picture:

100-the first permanent magnet assembly;

101-the first main permanent magnet; 102-the second main permanent magnet; 103-the first iron yoke; 103a-the surface of the first iron yoke; 200-the second permanent magnet assembly;

201-the third main permanent magnet; 202-the fourth main permanent magnet; 203-the second iron yoke; 203a-the surface of the second iron yoke; 300-the first coil assembly;

300a-partial coil of the first coil assembly; 300b partial coil of the first coil assembly; 400-third permanent magnet assembly;

111-the first attached permanent magnet; 112-the second attached permanent magnet; 113-the third attached permanent magnet; 500-the fourth permanent magnet assembly;

211-the fourth attached permanent magnet; 212-the fifth attached permanent magnet; 213-the sixth attached permanent magnet; 600-the second coil assembly;

600a-the effective coil part of the second coil assembly; 600b-the effective coil part of the second coil assembly; 700-the fifth permanent magnet assembly;

104-the fifth main permanent magnet; 800-the sixth permanent magnet assembly;

204-the sixth main permanent magnet;

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings to the principle, structure and working process of the present invention.

FIG. 3 is an axonometric view of the structure of the first solution of the voice coil motor provided by the present invention, and FIG. 4 is a top view of the structure of the first solution in FIG. . The length of each permanent magnet assembly along the Y-axis direction is L, the motor mover is a permanent magnet assembly, and the distance that each permanent magnet assembly moves along the Y-axis direction is L1, and the coil part parallel to the Y-axis in the first coil assembly 300 is along the Y axis. The length of the axis is L2. In the present invention, the freedom of movement of the voice coil motor along the Y-axis direction is added, that is, the length L2 of the coil in the first coil assembly 300 parallel to the Y-axis along the Y-axis direction is greater than or equal to that of each permanent magnet assembly. The sum of the length L along the Y-axis direction and the moving distance L1 of the permanent magnet assembly along the Y-axis direction, even if there is an installation error in the Y direction between each permanent magnet assembly and the first coil assembly 300, or each permanent magnet assembly is caused by an external force. Moving along the Y-axis, the resultant Lorentz force along the Y-axis direction received by each permanent magnet assembly is always zero. On the other hand, when each permanent magnet assembly moves along the Y direction, the effective coil areas in the first permanent magnet assembly 100 and the second permanent magnet assembly 200 remain unchanged, so the thrust of the motor along the X direction remains unchanged.

Fig. 5 is a sectional view of A-A section of the structure in Fig. 3 . The structure of Solution 1 includes a first permanent magnet assembly 100 , a second permanent magnet assembly 200 and a first coil assembly 300 . The first coil assembly 300 is located between the plane frames of the first permanent magnet assembly 100 and the second permanent magnet assembly 200 with a gap.

As shown in FIG. 5 , the first permanent magnet assembly 100 includes a first main permanent magnet 101 , a second main permanent magnet 102 , and a first iron yoke 103 . The second permanent magnet assembly 200 includes a third main permanent magnet 201 , a fourth main permanent magnet 202 , and a second iron yoke 203 . The first main permanent magnet 101 and the second main permanent magnet 102 are adhesively fixed on the surface 103 a of the first iron yoke 103 , and there is a gap between the first main permanent magnet 101 and the second main permanent magnet 102 . The third main permanent magnet 201 and the fourth main permanent magnet 202 are adhesively fixed on the surface 203 a of the second iron yoke 203 , and there is a gap between the third main permanent magnet 201 and the fourth main permanent magnet 202 . The magnetization directions of the second main permanent magnet 102 and the fourth main permanent magnet 202 are along the positive direction of the Z axis, the magnetization directions of the first main permanent magnet 101 and the third main permanent magnet 201 are along the negative direction of the Z axis, and the first main permanent magnets are along the negative direction of the Z axis. The N pole surface of the magnet 101 is opposite to the S pole surface of the third main permanent magnet 201, and the S pole surface of the second main permanent magnet 102 is opposite to the N pole surface of the fourth main permanent magnet 202, so in the first permanent magnet assembly 100 A closed magnetic circuit is formed with the second permanent magnet assembly 200 .

The first coil assembly 300 is located between the first permanent magnet assembly 100 and the second permanent magnet assembly 200 . Wherein the coil 300a part of the first coil assembly 300 is located between the first main permanent magnet 101 and the third main permanent magnet 201, and the coil 300b part of the first coil assembly 300 is located between the second main permanent magnet 102 and the fourth main permanent magnet 202 between. The wire direction of the coil 300a part and the coil 300b part is along the Y-axis direction, the magnetic field generated between the first main permanent magnet 101 and the third main permanent magnet 201 passes through the surface of the coil 300a part vertically, the second main permanent magnet 102, the fourth main permanent magnet The magnetic field between the main permanent magnets 202 passes through part of the surface of the coil 300b perpendicularly. When the first coil assembly 300 is energized, the direction of the current in the coil is perpendicular to the direction of the magnetic field in the area, so Lorentz force will be generated. The direction of the Lorentz force, the current direction of the energized coil and the direction of the magnetic induction intensity are perpendicular to each other, so that the mover can move along the X-axis under the action of the Lorentz force.

Fig. 6 is an axonometric view of the second structure of the voice coil motor of the present invention, Fig. 7 is a top view of the second structure of the voice coil motor, and Fig. 8 is a cross-sectional view of the second structure along the B-B plane. The second structure includes the third permanent magnet assembly 400 , the fourth permanent magnet assembly 500 , and the first coil assembly 300 . The length of each permanent magnet assembly along the Y-axis direction is L, the motor mover is a permanent magnet assembly, and the distance that each permanent magnet assembly moves along the Y-axis direction is L1, and the coil part parallel to the Y-axis in the first coil assembly 300 is along the Y axis. The length of the axis is L2, and the voice coil motor has a degree of freedom of movement along the Y-axis in the structure of the second scheme, that is, the length L2 of the coil in the first coil assembly 300 parallel to the Y-axis along the Y-axis is greater than or equal to that of each permanent magnet The sum of the length L of the assembly along the Y-axis direction and the moving distance L1 of each permanent magnet assembly along the Y-axis direction.

In the structure of the third permanent magnet assembly 400, there are first attached permanent magnet 111, first main permanent magnet 101, second attached permanent magnet 112, second main permanent magnet 102, and third attached permanent magnet along the positive direction of the X axis. 113. The main and auxiliary permanent magnets are bonded to each other along the X-axis direction, and are bonded and fixed on the surface 103 a of the first iron yoke 103 . In the fourth permanent magnet assembly 500, the fourth permanent magnet 211, the third main permanent magnet 201, the fifth permanent magnet 212, the fourth main permanent magnet 202, and the sixth permanent magnet along the positive direction of the X-axis 213. The main and attached permanent magnets are bonded together along the X-axis direction, and are bonded and fixed on the surface 203 a of the second iron yoke 203 . The magnetization direction of the first attached permanent magnet 111, the third attached permanent magnet 113, and the fifth attached permanent magnet 212 is the positive direction of the X axis, and the second attached permanent magnet 112, the fourth attached permanent magnet 211, and the sixth attached permanent magnet 213 The magnetization direction is the negative direction of the X axis. The magnetic field directions of each attached permanent magnet and each main permanent magnet are perpendicular to each other, and the N pole surface of the first main permanent magnet 101 is opposite to the S pole surface of the third main permanent magnet 201, and the S pole surface of the second main permanent magnet 102 is opposite to the S pole surface of the second main permanent magnet 102. The N-pole faces of the fourth main permanent magnet 202 are facing each other. The Halbach array forms are respectively formed in the third permanent magnet assembly 400 and the fourth permanent magnet assembly 500, and between the third permanent magnet assembly 400 and the fourth permanent magnet assembly 500 A closed magnetic circuit is formed between them. Compared with the permanent magnet components in the first solution, the permanent magnet components in the second solution have additional permanent magnets, so the magnetic field and the air gap magnetic induction can be enhanced, and the thrust can be increased.

The first coil assembly 300 is located between the third permanent magnet assembly 400 and the planar skeleton of the fourth permanent magnet assembly 500 . Wherein the 300a coil portion of the coil is located between the first main permanent magnet 101 and the third main permanent magnet 201, and a gap is left, and the 300b coil portion of the coil is located between the second main permanent magnet 102 and the fourth main permanent magnet 202, And leave a gap. The wire direction of the coil 300a part and the coil 300b part is along the Y-axis direction, the magnetic field generated between the first main permanent magnet 101 and the third main permanent magnet 201 passes through the coil surface of the 300a part of the coil vertically, and the second main permanent magnet 102 and The magnetic field between the fourth main permanent magnet 202 is perpendicular to the coil surface of the part 300b of the coil. When the coil is energized, the direction of the current is perpendicular to the direction of the magnetic field in the area, so a Lorentz force will be generated. The direction of the Lorentz force, the current direction of the energized coil and the direction of the magnetic induction intensity are perpendicular to each other, so that the mover of the voice coil motor can move along the X-axis direction under the action of the Lorentz force.

Fig. 9 is a structural axonometric view of the third embodiment of the voice coil motor of the present invention, Fig. 10 is a top view of the structure of the third embodiment, and Fig. 11 is a cross-sectional view of the structure of the third embodiment C-C. The third structure includes the fifth permanent magnet assembly 700 , the sixth permanent magnet assembly 800 , the first coil assembly 300 and the second coil assembly 600 . The first coil assembly 300 and the second coil assembly 600 are located between the fifth permanent magnet assembly 700 and the sixth permanent magnet assembly 800 with a gap. The length of each permanent magnet assembly along the Y-axis direction is L, the motor mover is a permanent magnet assembly, and the distance that each permanent magnet assembly moves along the Y-axis direction is L1, the first coil assembly 300, the second coil assembly 600 and the Y-axis The length of the parallel coil part along the Y axis is L2. In the third structure, the degree of freedom of movement of the voice coil motor along the Y axis is increased, that is, the coils in the first coil assembly 300 and the second coil assembly 600 are parallel to the Y axis. The length L2 of the Y-axis direction is greater than or equal to the sum of the length L of each permanent magnet assembly along the Y-axis direction and the moving distance L1 of each permanent magnet assembly along the Y-axis direction.

The main and auxiliary permanent magnets in each permanent magnet assembly are bonded to each other along the X direction. In the permanent magnet assembly 700 , there are first main permanent magnet 101 , second auxiliary permanent magnet 112 , second main permanent magnet 102 , third auxiliary permanent magnet 113 , and fifth main permanent magnet 104 along the positive direction of the X-axis. The main and attached permanent magnets are glued together along the X-axis direction, and are glued and fixed on the surface 103 a of the first iron yoke 103 . In the sixth permanent magnet assembly 800, there are the third main permanent magnet 201, the fifth attached permanent magnet 212, the fourth main permanent magnet 202, the sixth attached permanent magnet 213, and the sixth main permanent magnet along the positive direction of the X axis. 204. The magnetization direction of the fifth main permanent magnet 104 and the sixth main permanent magnet 204 is the negative direction of the Z axis. The N pole face of the first main permanent magnet 101 faces the S pole face of the third main permanent magnet 201, the S pole face of the second main permanent magnet 102 faces the N pole face of the fourth main permanent magnet 202, and the fifth main permanent magnet The N pole face of the magnet 104 faces the S pole face of the sixth main permanent magnet 204 . The magnetic field directions of each main and auxiliary permanent magnets are perpendicular to each other, so the Halbach array form is respectively formed in the fifth permanent magnet assembly 700 and the sixth permanent magnet assembly 800, and in the fifth permanent magnet assembly 700 and the sixth permanent magnet assembly 800 A closed magnetic circuit is formed between them.

There are two coil components in the structure of the third solution, namely the first coil component 300 and the second coil component 600 . The winding planes of the first coil assembly 300 and the second coil assembly 600 are in the same plane, and are located between the plane skeleton of the fifth permanent magnet assembly 700 and the sixth permanent magnet assembly 800 . The 300a coil part of the first coil assembly 300 is located between the first main permanent magnet 101 and the third main permanent magnet 201, and there is a gap, and the 300b coil part of the first coil assembly 300 is located between the second main permanent magnet 102 and the third main permanent magnet 201. There are gaps between the four main permanent magnets 202 . The 600a coil part of the second coil assembly 600 is located between the second main permanent magnet 102 and the fourth main permanent magnet 202, and the direction is along the Y-axis direction, and the 600b coil part of the second coil assembly 600 is located between the fifth main permanent magnet 104 and the fourth main permanent magnet 202. Between the six main permanent magnets 204, the direction is along the Y-axis direction. The magnetic field between the first main permanent magnet 101 and the third main permanent magnet 201 passes through part of the coil surface of the coil 300a of the first coil assembly vertically, and the magnetic field between the second main permanent magnet 102 and the fourth main permanent magnet 202 passes through vertically. Through the coil 300b part of the coil surface of the first coil assembly, the magnetic field between the second main permanent magnet 102 and the fourth main permanent magnet 202 is perpendicular to the coil 600a part of the coil surface of the second coil assembly, the fifth main permanent magnet 104, The magnetic field between the sixth main permanent magnet 204 passes perpendicularly across the coil surface of the second coil assembly 600 at 600b part. When the coil is energized, the direction of the current is perpendicular to the direction of the magnetic field, so a Lorentz force will be generated. The direction of the Lorentz force, the current direction of the energized coil and the direction of the magnetic induction intensity are perpendicular to each other, and the mover of the voice coil motor can move along the X-axis direction under the action of the Lorentz force.

FIG. 12 is an axonometric view of the fourth structure of the voice coil motor of the present invention, and FIG. 13 is a top view of the fourth structure of the voice coil motor. The structure includes a first permanent magnet assembly 100 , a second permanent magnet assembly 200 , and a first coil assembly 300 . In the structure of Scheme 4, the electric mover is the first coil assembly 300, and the length L of each permanent magnet assembly along the Y-axis direction is greater than or equal to the length L2 of the coil parallel to the Y-axis in the first coil assembly 300 and the length L2 of the first coil assembly 300 along the Y-axis direction. A coil assembly 300 is moved along the Y-axis by the sum of the distance L3.

FIG. 14 is a top view of the fifth structure of the voice coil motor of the present invention, the structure includes a third permanent magnet assembly 400 , a fourth permanent magnet assembly 500 , and a first coil assembly 300 . In the structure of Scheme 5, the electric mover is the first coil assembly 300, and the length L of each permanent magnet assembly along the Y-axis direction is greater than or equal to the length L2 of the coil parallel to the Y-axis in the first coil assembly 300 and the length L2 of the first coil assembly 300 along the Y-axis direction. A coil assembly 300 is moved along the Y-axis by the sum of the distance L3.

Figure 15 is an axonometric view of the sixth structure of the voice coil motor of the present invention, and Figure 16 is a top view of the sixth structure of the voice coil motor, which includes the fifth permanent magnet assembly 700, the sixth permanent magnet assembly 800, the first coil assembly 300, and the second coil assembly 600. In the structure of Scheme 6, the electric mover is the first coil assembly 300 and the second coil assembly 600, and the length L of each permanent magnet assembly along the Y-axis direction is greater than or equal to the first coil assembly 300, and the second coil assembly 600 is parallel to the Y-axis The sum of the length L2 of some coils along the Y-axis direction and the moving distance L3 of the first coil assembly 300 and the second coil assembly 600 along the Y-axis direction.

Claims (2)

1. A voice coil motor, which comprises two permanent magnet assemblies up and down and a coil assembly arranged between the two permanent magnet assemblies up and down; each permanent magnet assembly includes two main permanent magnets and iron yoke , the magnetization direction of the main permanent magnet is along the Z-axis direction and arranged in a conventional array form, a closed magnetic field is formed between the permanent magnet components; the closed magnetic field passes through the effective surface of the coil component vertically, the current direction is perpendicular to the magnetic field direction, and a Lorentz force is generated The mover of the driving motor moves along the X direction, and the feature is that the freedom of movement of the voice coil motor along the Y-axis direction is increased, that is, when the permanent magnet assembly is the mover, the coil of the coil assembly parallel to the Y-axis moves along the Y-axis direction The length L2 of the permanent magnet assembly is greater than or equal to the sum of the length L of the permanent magnet assembly along the Y-axis direction and the moving distance L1 of the permanent magnet assembly along the Y-axis direction; when the coil assembly is used as a mover, the length L of the permanent magnet assembly along the Y-axis direction is greater than or equal to The sum of the length L2 of the coil parallel to the Y-axis in the coil assembly along the Y-axis direction and the moving distance L3 of the coil assembly along the Y-axis direction. 2. A voice coil motor, which comprises two permanent magnet assemblies up and down and one or two coil assemblies arranged between the two permanent magnet assemblies up and down; each permanent magnet assembly includes a main permanent magnet, an auxiliary Permanent magnet and iron yoke; the magnetization direction of the main permanent magnet is along the Z-axis direction, and the magnetization direction of the auxiliary permanent magnet is along the X-axis direction. Each permanent magnet assembly is arranged in the form of a Halbach array, and a closed magnetic field is formed between each permanent magnet assembly; closed The magnetic field passes through the effective surface of the coil assembly vertically, and the direction of the current is perpendicular to the direction of the magnetic field, generating Lorentz force to drive the motor mover to move along the X direction. When the magnet assembly is a mover, the length of the coil in the coil assembly parallel to the Y-axis along the Y-axis direction is greater than or equal to the sum of the length of the permanent magnet assembly along the Y-axis direction and the moving distance of the permanent magnet assembly along the Y-axis direction; when the coil assembly When used as a mover, the length L of the permanent magnet assembly along the Y-axis direction is greater than or equal to the sum of the length L2 of the coil in the coil assembly parallel to the Y-axis direction along the Y-axis direction and the moving distance L3 of the coil assembly along the Y-axis direction.

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