KR101916939B1 - A micro scanner, and fabrication method for the micro scanner - Google Patents

Abstract

A micro scanner according to the present invention includes: a first mass part; A first driving unit provided at an outer periphery of the first mass part at the same center as the first mass part; A second mass portion provided at an outer portion of the first driving portion apart from the first driving portion and coaxially with the first mass portion; A one-way first spring and a one-way second spring provided in one direction so as to connect the first driving portion to the first mass portion and the second mass portion, respectively; A second driving unit provided at an outer periphery of the second mass unit at the same center as the first mass unit; A stationary frame placed on an outer side of the second driving unit; And a bi-directional first spring and a bi-directional second spring provided in opposite directions crossing the one direction so as to connect the second driving portion to the second mass portion and the fixed frame, respectively.

Description

[0001] The present invention relates to a micro scanner, and a method of manufacturing the micro scanner,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro scanner and a method of manufacturing the micro scanner, and more particularly, to a micro scanner and a method of manufacturing the micro scanner, which can be driven using an electromagnetic force.

Micro scanners have the advantages of speed, size, weight, low power and low manufacturing cost compared to conventional galvano scanners. The micro-scanner can be manufactured and operated in a very small size based on MEMS (MEMS) technology.

On the basis of this, micro-scanners have recently been used in various fields such as printers, measuring equipment, precision processing, head-up displays, motion trackers, pico projectors, optical coherence tomography (OCT) light detection and ranging (LiDAR)).

The micro scanner may be driven by electromagnetic force, electrostatic force, heat, and piezoelectric according to a driving method. On the other hand, in order to realize a large optical scan angle, such as the Rada and Pico projectors, an electromagnetic force system having a large torque is preferable.

U.S. Patent No. 2010/0073748 (Cited Document 1) discloses a structure in which a first mass portion (a first mass portion can be understood as a scanner or a mirror, for example) driven by a conductor arranged substantially in the X-axis and Y- The permanent magnets are arranged in the direction of 45 degrees. According to this technique, there is a problem in that alignment between the permanent magnet and the first mass portion becomes difficult due to the current flowing in the conductor and the magnetic field of the permanent magnet, and the size becomes large.

In addition, cross coupling can occur between the two axes X / Y for scanning, so that either action can affect the motion of the other axis. The cross coupling occurs because the conductors for driving between the two axes are performed by a single conductor and the magnetic field is inclined at an angle of 45 degrees with respect to each axis.

Further, according to the cited document 1, when the torque is increased, there is a fear that dynamic deformation in which the first mass portion is deformed by itself may occur. It can be understood that the dynamic deformation modifies the first mass portion in accordance with the vibration mode form of the first mass portion during the rotation operation of the first mass portion. This work becomes larger when the driving frequency of the first mass portion is large. There is a problem that the scanning operation of the laser beam can not be accurately performed due to the problem that the reflection angle is distorted when the dynamic deformation occurs.

As another prior art (cited document 2), OPTICS EXPRESS VOL. 24, No. 14, pages 15813 to 15821, Aleum Han, Chang-Hyeon Ji etc. For example, the 'electromagnetic biaxial vector scanner using a radial magnetic field' can be used.

In the cited document 2, a radial magnet was placed on the lower side of the substrate, and individual conductors for the X / Y axes were intervened. As a result, compared with Reference 1, cross coupling between the two axes is reduced and the effect of reducing the volume is obtained. In addition, a multi-turn is provided for one axis (inner rotation axis) so that a large torque is generated even by a small current. However, there is a problem that a large torque can be obtained for only one uniaxial axis.

Figure 3 and related discussion of U. S. Patent 2010/0073748

OPTICS EXPRESS VOL. 24, No. 14, pages 15813 to 15821, Aleum Han, Chang-Hyeon Ji etc. 6B of the " Electromagnetic biaxial vector scanner using radial magnetic field "

The present invention proposes a micro scanner, and a method of manufacturing a micro scanner, that individually provide a large scan angle for both axes.

A micro scanner according to the present invention includes: a first mass part having a reflective layer on one surface; A first driving unit provided at an outer periphery of the first mass part at the same center as the first mass part; A second mass portion provided at an outer portion of the first driving portion apart from the first driving portion and coaxially with the first mass portion; A one-way first spring and a one-way second spring provided in one direction so as to connect the first driving portion to the first mass portion and the second mass portion, respectively; A second driving unit provided at an outer periphery of the second mass unit at the same center as the first mass unit; A stationary frame placed on an outer side of the second driving unit; A bi-directional first spring and a bi-directional second spring provided in opposite directions crossing the one direction so as to connect the second driving portion with the second mass portion and the fixed frame, respectively; A first electric wire provided to the first driving unit and through which a current supplied from the outside flows; A second electric wire provided to the second driving unit and through which a current supplied from the outside flows; And a magnetic field generating unit disposed below the first driving unit and the second driving unit and spaced apart from each other by a predetermined distance.

Here, the upper side of the first mass portion may be used as a reflection plate, and the lower portion of the first mass portion may be used as a reflector when a reinforcing portion is added above the first mass portion to reduce the dynamic deformation of the first mass portion.

According to another aspect of the present invention, there is provided a method of manufacturing a micro scanner, comprising: providing an insulating film on an upper side of an SOI substrate and a lower side of the SOI substrate; Providing a patterned metal layer over the SOI substrate; Selectively removing an upper portion of the SOI substrate except for the metal layer by a deep reactive ion etching (DRIE) process, thereby providing a substrate structure for a micro scanner; Removing a lower portion of the SOI substrate by an etching process to provide a depression; And providing a reflective layer on the depressed surface. When providing the metal layer, a reinforcing portion is provided together with the upper side of the SOI substrate to suppress the dynamic strain of the electric wire and the moving first mass portion.

According to still another aspect of the present invention, there is provided a micro scanner comprising: a first mass part having a reflective layer on one surface; A first driving unit disposed on a spaced apart outer side of the first mass part; A second mass located on an outer side of the first drive; A second driving unit disposed on a spaced apart outer side of the second mass part; A stationary frame placed on an outer side of the second driving unit; A unidirectional first spring and a unidirectional second spring for connecting the first driving portion to the first mass portion and the second mass portion to allow dynamic amplification of the first driving portion; A bi-directional first spring and a bi-directional second spring connecting the second driving portion to the second mass portion and the fixed frame to allow dynamic amplification of the second driving portion; A first electric wire provided to the first driving unit and through which a current supplied from the outside flows; A second electric wire provided to the second driving unit and through which a current supplied from the outside flows; And a magnetic field generator positioned below the first driver and the second driver.

According to the present invention, a large scan angle can be obtained for each of the two axes.

According to the present invention, both axes can implement a larger scan angle using dynamic amplification.

According to the present invention, it is possible to reduce the fatigue breakage of the metal lead used for the individual drive of the two shafts.

According to the present invention, a plurality of turns can be implemented for two axes, so that a large torque can be obtained even at a low power.

According to the present invention, the V-shape and W-shape springs are used to increase the scan angle and to suppress motion in the sliding and yaw directions.

1 is a plan view of a substrate provided in a micro-scanner;
2 is a plan view of a magnet placed on the underside of a substrate provided in the micro-scanner;
3 is a view for explaining an alignment relationship between a substrate and a magnetic field generating portion;
4 is a view showing a magnetic flux vector as it goes radially from the center of the magnetism generating portion.
5 is a graph showing the magnetic flux density in the radial direction when radially going out from the center of the magnetism generating portion.
6 is a plan view of a substrate for explaining the arrangement of a conductor and the generation of an electromagnetic force;
Figs. 7 to 12 are views sequentially showing a manufacturing method of a micro scanner. Fig.
13 is a plan view photograph of the micro scanner.
14 is an enlarged view of a portion A in Fig.
15 is an enlarged view of a portion C in Fig.
FIG. 16 is an enlarged view of a portion B in FIG. 13; FIG.
17 is an enlarged view of a portion D in Fig.
18 is a view showing vibration resonance frequencies in order to explain the strength of a W-shape spring when compared with an I-shape spring;
Fig. 19 is a view showing rotation stiffness in order to explain the strength of a W-shape spring when compared with an I-shape spring. Fig.
20 is a view showing a rotation angle in order to explain the strength of a W-shape spring when compared with an I-shape spring;
FIGS. 21 and 22 are views showing frequency response characteristics of the vertical and horizontal axes of the micro scanner. FIG.
23 and 24 are graphs showing the twist angle of the vertical axis for each voltage (Vpp) in the static mode and the resonance mode on the vertical axis.
25 is a graph showing the twist angle of the horizontal axis for each voltage (Vpp) in the resonance mode of the horizontal axis.
Figs. 26 and 27 show the result of performing laser reflection in the case of driving only one axis among the horizontal axis and the vertical axis without driving the other axis. Fig.
28 to 30 are photographs in which the laser is reflected in a raster scan mode in which the vertical axis is a static mode and the horizontal axis is a resonance mode.
31 and 32 are photographs in which the laser beam is reflected in the Lissajous mode in which the vertical axis and the horizontal axis are set to the resonance mode.
33 is a plan view of a micro scanner according to another embodiment;
34 is an enlarged view of E in Fig.
35 is an enlarged view of F in Fig. 33;

The constitution of the present invention and the effect thereof will be more clearly understood by the following examples.

On the other hand, in the following description of the embodiment, each part is often provided with a pair of parts symmetrical to each other. In this case, any one of the parts will be described and a symmetrically paired component will not be described. However, the same description applies. Also, in order to explain the operation of the parts in the drawings, the parts may be highlighted and displayed differently from the actual articles, but this is for the sake of understanding, and the size and the specific shape may be changed.

FIG. 1 is a plan view of a substrate provided on a micro scanner, and FIG. 2 is a plan view of a magnet placed on a lower side of a substrate provided on a micro scanner.

Referring to FIG. 1, a stationary frame 5, which is illustrated in a rectangular shape, is placed on a substrate 1. Inside the stationary frame 5, a driving part 20 for driving the first mass part 10 A plurality of springs 60, 61, 80, and 81 for elastically supporting a deforming force applied from the driving unit and a plurality of springs 60, A second mass portion 300 is provided to perform a gimbal function.

The driving unit, the spring, and the second mass unit are paired on the first mass unit (in the case of a spring) or have the same center of gravity (in the case of the driving unit and the second mass unit) . As a result, the micro scanner can be driven smoothly.

Electrical conductors are provided in the driving portion, the spring and the second mass portion so that electromagnetic force necessary for movement of the first mass portion 10 is generated by the action of the magnet in Fig.

The detailed configuration of the driving portion, the spring, and the second mass portion will be described.

The driving unit includes a first driving unit 20 for generating a torsional movement with the horizontal axis of the first mass unit 10 as a center axis on the basis of the drawing, And a second driving unit 40 for generating a torsional motion with the vertical direction of the first driving unit 10 as a central axis.

The connection between the first driving part 20 and the first mass part 10 is achieved by a pair of unidirectional first springs (not shown) connecting the first driving part 20 and the first mass part 10 in the horizontal direction 60). In other words, the first mass portion 10 is located at the innermost position, and is radially arranged in the shape of a pair of unidirectional first springs 60 and a circular mold (donut shape for the sake of understanding) The driving unit 20 is placed.

And a second mass portion 300 is disposed outside the first driving portion 20. [ The second mass part 300 is not a part for directly providing a driving force but is a part for connecting the first driving part 20 and the second driving part 40. The second mass portion 300 can reduce the influence of deformation that occurs during driving due to each of the driving portions 20 and 40 between the driving portions so that the dynamic amplification described later can be smoothly performed can do.

The connection between the second mass part 300 and the first driving part 20 may be realized by a pair of unidirectional second springs connecting the first driving part 20 and the second mass part 300 in the horizontal direction 61). In other words, the first driving portion 20 is located inside, is radially provided with a pair of unidirectional second springs 61, and a second mass portion, which is presented in the form of a circular frame (donut shape for the sake of understanding) (300).

When the first driving unit 20 is viewed as a center, a unidirectional first spring 60 is provided on the inside and a unidirectional second spring 61 is provided on the outside of the first driving unit 20. Therefore, the force generated by the first driving unit 20 is supported by the unidirectional first spring and the unidirectional second spring 60 (61), amplified by the resonance phenomenon, and transmitted to the first mass unit 10 . For this purpose, the unidirectional first spring and the unidirectional second spring may be connected in the same direction when viewed from the first mass portion 10. In other words, it can be understood that one direction refers to the same direction.

As a result of the static operation of the first mass part 10, the unidirectional first spring 61 and the unidirectional second spring 60 (61) Respectively. However, in the dynamic driving of the present invention, even if the twisting force of the first driving part 20 is small, the first mass part 10 is dynamically amplified by the unidirectional first spring and the unidirectional second spring 60 (61) The inclination angle of the first mass portion 10 may be amplified.

By the dynamic amplification, the conductor provided on the unidirectional second spring 61 can be twisted with a small deformation. That is, even if the first mass portion 10 is greatly inclined, the spring 61 can be slightly twisted, so that fatigue breakdown that may occur in a metal wire can be suppressed.

Since the unidirectional second springs 61 are branched from each other in a "V" shape, the two rods provided in the spring are prevented from short-circuiting, So that a relatively small spring constant can be obtained.

The second mass part 300 is connected to the second driving part 40 outwardly.

More specifically, the connection between the second driving unit 40 and the second mass unit 300 may be realized by connecting the second driving unit 40 and the second mass unit 300 in the vertical direction, 80). In other words, the second driving portion 40 is connected to the second mass portion 300 by the pair of bi-directional first springs 80 in the vertical radial direction with the second mass portion 300 inside.

A fixed frame 5 is placed on the outside of the second driving part 40.

The connection between the second driving unit 40 and the stationary frame 5 may be realized by a pair of second directional second springs 81 connecting the second driving unit 40 and the stationary frame 5 in the vertical direction, Lt; / RTI > In other words, there is a pair of bi-directional second springs 81, in which the second drive part 40 is located inside and is provided in a vertical radial direction, and a stationary frame 5 which is presented in the form of a square frame.

When the second driving part 40 is viewed as a center, a bi-directional first spring 80 and a bi-directional second spring 81 are provided around the second driving part 40. Therefore, the force generated by the second driving unit 40 is supported by the bi-directional first spring and bi-directional second spring 60 (61), amplified by the dynamic amplification, and transmitted to the second mass unit 300 Lt; / RTI > For this purpose, the bi-directional first spring and the bi-directional second spring may be connected in the same direction when viewed from the first mass portion. In other words, it can be understood that the direction is referred to as the same direction, and when the direction is different from the one direction, and preferably, when the one direction is the horizontal direction, the direction may be provided in the vertical direction.

As shown in FIG. 5, when the second mass portion 300 is inclined, the bi-directional first spring 80 and the bi-directional second spring 81 move in the direction of the second mass portion 300, Can support the respective inclination angles. However, in the dynamic driving, even if the torque of the second driving part 40, that is, the torsional force is small, it is amplified by the bi-directional first spring and bi-directional second spring 60 (61) The tilt angle can be dynamically amplified.

By the dynamic amplification, the conductor provided in the bi-directional second spring 81 can be deformed small. That is, even if the second mass portion 300 is largely inclined, the spring 81 can be twisted to a small extent, so that the fatigue breakage of the metal wire can be suppressed.

The bi-directional second spring 81 may have a large " W "shape and may have a large supporting force, and may prevent shorting of three wires in the first place, A relatively small spring constant can be obtained by an empty space portion.

The bi-directional second spring 81 is of a " W "shape and the unidirectional second spring 61 may be provided differently as a" V " According to this, there is an advantage that the rotation rigidity is reduced, the scan angle is increased, and the rigidity in the sliding direction is increased, thereby suppressing motion in an undesired direction.

Fig. 2 shows a magnetic field generating part provided on one side of the upper and lower sides of the substrate.

Referring to FIG. 2, the magnetic field generating unit 100 is a part for supplying a magnetic field to the driving units 20 and 40. The magnetic field generating section 100 has a concentric circle as seen from a plan view of the magnetic field generating section 100 shown in the lower side of FIG. 2, and has the innermost first magnet 101, The second magnet 102, and the third magnet 103 outside the second magnet.

The polarities of the magnets 101, 102, and 103 are provided alternately to each other, as can be seen from the side view of the magnetic field generator 100 shown in the lower side of FIG.

3 is a view for explaining an alignment relationship between the substrate and the magnetic field generating portion.

Referring to FIG. 3, the magnetic field generating unit 100 is placed on the upper side or the lower side of the substrate 1, so that the operation of the micro scanner is not affected. However, for convenience of explanation, it is assumed that the magnetic field generating unit 100 is provided below the substrate 1.

In Fig. 3, three meshing guide lines 2011 (2021) and 2031 are shown. Each of the marking leader lines is shown by point by point where the substrate 1 and the magnetic field generator 100 are vertically aligned. The first marking guide line 2011 connects the center 201 of the line width of the first driving unit 20 and the point 201 between the first magnet 101 and the second magnet 102, (2011) are aligned vertically. The second marking line 2021 connects the center 202 of the line width of the second mass part 300 and the center of the line width of the second magnet 102. The point at which the second marking line 2021 connects is vertical . The third matching leader 2031 connects the center 203 of the line width of the second driving unit 40 and the point 203 between the second magnet 102 and the third magnet 103, (2031) are vertically aligned.

The coupling of the marking leaders is performed such that the magnetic field in the magnetism generating unit 100 generates the maximum electromagnetic force by applying the highest effective magnetic flux to the driving units 20 and 40, ), The minimum effective magnetic flux is applied to generate the minimum electromagnetic force.

The characteristics of the electromagnetic force generated in the driving units 20 and 40 and the second mass unit 300 will be described in more detail. It should be understood that the following description of electromagnetic force and magnetic field has an engineering error.

FIG. 4 is a view showing a magnetic flux vector when radially moving from the center of the magnetism generating portion, and FIG. 5 is a graph showing a magnetic flux density in a radial direction as it goes radially from the center of the magnetism generating portion.

It can be assumed that the magnetic flux density shown in Fig. 5 is the data of 450 micrometers above the surface of the magnetism generating portion 100, and the substrate 1 is placed at that position. The gap between the substrate and the magnetism generating portion can act as an interval for allowing the rotation of the first mass portion 10. Hereinafter, the description of the magnetic flux density will be described with reference to FIG.

4 and 5, the magnetic flux gradually increases in the radial direction, and the magnetic flux directed toward the inside (the center direction of the magnetism generating portion) becomes the maximum in the first matching line 201. A maximum torque can be generated in the first driving unit 20 aligned with the first matching line 201. [

As the magnetic flux passes through the first matching line 201 in the radial direction, the magnetic fluxes radially inward and outward are canceled, and the magnetic flux density becomes zero. In the second matching line 202 where the magnetic flux density becomes zero, there is no magnetic flux density. No torque is generated in the second mass portion 300 that is aligned with the second matching line 202.

The magnetic flux gradually increases in the radial direction passing through the second matching line 202, and the magnetic flux directed toward the outside (radial direction) in the third matching line 203 becomes the maximum. A maximum torque can be generated in the second driving unit 40 aligned with the third matching line 203.

After passing through the third matching line, the magnetic flux can be gradually reduced.

According to the alignment relationship between the substrate 1 and the magnetism generation unit 100, the maximum electromagnetic force and torque are generated in the driving units 20 and 40 and the electromagnetic force is not generated in the second mass unit 300 have.

6 is a plan view of the substrate for explaining the arrangement of the conductive wire and the generation of the electromagnetic force.

6, a first wire 70 for supplying a current to the first driving unit 20 is connected to the second frame 70 through a second forward biasing spring 812 through a terminal provided in the fixed frame 5, do. Then, after passing through the second driving portion 40 as it is, the air passes through the bi-directional first spring 80 and reaches the second mass portion 300. And then extends 90 degrees in the circumferential direction along the second mass portion 300. Thereafter, the unidirectional second spring 61 is divided into two branches by the first unidirectional second spring 611 and the second unidirectional second spring 612, and passes through the first driving part 20. And then extend to the stationary frame 5 as shown in the direction symmetrical with the above description.

Of the first wires 70, the current direction of the first active conductor 72 extending along the first driving part 20 is not radially symmetrical but symmetrical up and down. In other words, the current directions of the first active conductive lines 72 flow in the same direction to the right, with reference to the drawing. Accordingly, when the magnetic field in the radial direction is applied to the first matching line 201, the first driving unit 20 can vibrate and rotate in a twisted manner about the horizontal axis because the current direction is symmetrical up and down. Specifically, it can be understood by referring to the direction of the magnetic field (B) and the direction of the current (I) shown in the figure and the direction of the resulting electromagnetic force.

The current direction of the first connection portion 71 extending along the second mass portion 300 among the first electric wires 70 is symmetrical in the radial direction but the magnetic field of the magnetic field generating portion 100 is in the radial direction The electromagnetic force is not generated.

An electromagnetic force is not generated in the first connection portion 71 so that no force is generated in the second mass portion 300 and an electromagnetic force is applied to the first active wire 72. [ And a torque is generated in the first driving unit 20. As shown in FIG.

The second wire 90 for supplying current to the second driving part 40 is branched from the terminal provided to the stationary frame 5 and is drawn in and out through the bi-directional second springs 811 and 813. Next, the second driving unit 40 is divided into two parts.

Of the second wires 90, the current direction of the second active conductor 91 extending along the second drive part 40 is not radially symmetrical but symmetrical to the left and right. In other words, the current direction of the second active conductor 91 flows downward in the same direction with reference to the drawing. Therefore, when the radial magnetic field is applied to the third matching line 203, the current direction is symmetrical to the left and the right, so that the second driving unit 40 can vibrate and rotate with respect to the vertical axis. Specifically, it will be fully understood by referring to the magnetic field direction B and the current direction I shown in the drawing, and the direction of the resulting electromagnetic force.

The electromagnetic force corresponding to the Lorentz force is generated by the current flowing along each of the electric wires 70 and 90 and the magnetic field of the magnetic field generating part 100 as described above and the driving parts 20 and 40 Torsion can be rotated.

An alternating current flows through the electric wire so that the driving part can vibrate and rotate. The first mass portion 10 is supplied with the alternating current at a resonance frequency corresponding to the shape of each driving portion, the spring, the second mass portion, and the vibration system of the first mass portion and the spring constant, It can be twisted and vibrated. At this time, the horizontal axis may be a high-speed axis that vibrates and rotates at high speed, and the vertical axis may be a low-speed axis that vibrates and rotates at a low speed.

On the other hand, the first mass portion 10 may be provided in a circular shape and may be provided in an elliptical shape in order to irradiate the laser obliquely when the first mass portion 10 is applied as a reflector of the laser, as the case may be.

The first mass portion 10 may be provided with a reinforcing portion 11 for suppressing dynamic deformation. As an example of the reinforcement portion 11, a cross shape can be exemplified. By increasing the area moment of inertia of the first mass portion 10, the reinforcement portion 11 is rotated at a high frequency, The deformation can be reduced. The reinforcement portion 11 may be provided in various shapes such as an orthogonal cross, a diagonal cross, a circle, a symmetrical rectangle, and combinations thereof. Since the reinforcing portion 11 can be provided together when the lead wires are provided, an advantage that a separate process is not required can be obtained.

Hereinafter, a method of manufacturing the micro scanner according to the embodiment will be described.

FIGS. 7 to 12 are views sequentially showing the method of manufacturing the micro scanner.

First, a substrate as shown in FIG. 7 is prepared. The substrate may be an SOI (Silicon On Insulator) substrate. The multilayer substrate 200 has a first silicon layer 205 and a second silicon layer 204 and has a lower insulating film 203 on the lower side and an upper insulating film 202 on the upper side and an insulating layer 201 . The insulating layer 201 and the insulating films 202 and 203 may be provided with silicon oxide (SiO 2).

Then, as shown in FIG. 8, a metal layer 210 is stacked on the upper surface of the multilayer substrate 200. The method of laminating the metal layer 210 may be performed by sputtering and laminating a seed layer (Cu / Ti), patterning using photoresist development, and then plating copper by electroplating .

The metal layer 210 not only provides the wires 70 and 90 but also the reinforcing part 11. In other words, since a wire and a reinforcing portion are provided together as a lead portion through a single process, a simple manufacturing process can be achieved. Considering that the microfabrication process applied in the field of MEMS has a problem in that the product yield is reduced as the number of manufacturing processes increases, the reinforcement portion 11 and the wires 70 and 90 can be provided in a single process It can have a good effect on product yield.

Thereafter, as shown in FIG. 9, the first silicon layer 205 is selectively removed by an upper insulating film 202 and a deep RIE process by an RIE process to form a substrate structure necessary for a micro scanner do. In other words, the fixed frame, the driving portion, the second mass portion, and the spring can be separated from each other.

Then, as shown in FIGS. 10 and 11, the second silicon layer 204 and the insulating layer 201 are sequentially removed. The recessed surface 210 may be provided at the lower portion of the multi-layer substrate 200.

Thereafter, as shown in FIG. 12, the reflective layer 212 is provided with a metal having a high reflectance on the lower surface including the recessed surface 210. The reflective layer 212 may be protected by a protective layer.

The reflective layer 212 may be a reflector reflecting the laser beam in the first mass portion 10 of the micro scanner. That is, when the first mass portion 10 rotates and vibrates, the laser beam incident on the reflection plate 212 is reflected at various angles, and the reflected light can be scanned by the laser beam, which is a point light source, in a wide space.

The process in which the multilayer substrate 200 becomes the substrate 1 of the micro scanner by the above process has been described. In the substrate of Fig. 12, the center portion may be the first mass portion 10 and the outermost portion may be the stationary frame 5, and each internal component may be provided with a drive portion, a second mass portion, and a spring.

13 is a plane photograph of a micro scanner actually manufactured.

Referring to Fig. 13, the center first mass portion of the substrate 1 is laid. FIG. 14 is an enlarged view of part A of FIG. 13, and FIG. 15 is an enlarged view of part C of FIG.

13 to 15, the unidirectional first spring 60 connected to the first mass portion 10 and the unidirectional second spring 61 connected to the first mass portion 10, And the second mass portion 300 is provided outwardly thereof. The first active conductor 72 and the first connection part 71 are laminated on the upper side of the first driving part 20 and the upper side of the second mass part 300.

FIG. 16 is an enlarged view of a portion B in FIG. 13, and FIG. 17 is an enlarged view of a portion D in FIG.

Referring to FIGS. 13, 16 and 17, the bi-directional first spring 80 and the bi-directional second spring 81 serve as a part mainly providing the vibration system of the second drive unit 40, 40) in the outside of the eye.

As described in the above description, the unidirectional second spring 61 and the bi-directional second spring 81 are provided in the shape of 'V' and 'W', respectively, Can be seen. This is to reduce the influence of the rotational motion of the scanner by increasing the spring stiffness in the direction of the yawing mode and the unnecessary sliding mode of the first mass part.

This will be described in more detail below.

According to the embodiment, the inclination angle of the first mass portion 10 can be increased by the dynamic amplification, and the resonance torsional vibrations of the horizontal axis and the vertical axis defined by the shape of the micro scanner at the time of designing can be achieved. In this case, it is possible to make the resonance frequency of the sliding mode of the first mass portion 10 and the resonance frequency of the yawing mode larger by increasing the spring constant of the springs 61 and 81 with respect to other modes except the rotation mode of the scanner will be.

Can be more easily understood with reference to the table of the resonance frequency according to the vibration mode shown in FIG.

18 shows the resonance torsional frequency, the resonant sliding frequency, and the resonant yaw frequency of the first mass part 10 in comparison with the case of using the I-shaped spring and the W-shaped spring .

When the resonant torsional frequency is designed to be 429 Hz by using the I-shaped spring and the W-shaped spring, the resonant sliding frequency is 1073 Hz and the resonant yawing frequency is 2180 Hz. On the other hand, in the case of the 'W' shaped spring, the resonance sliding frequency is 3777 Hz and the resonance yaw frequency is 4436 Hz.

According to the above simulation results, it can be seen that, by using a spring having a large spring constant, the resonance sliding frequency and the resonance yawing frequency become larger when compared with the required resonance torsional frequency. Therefore, the resonance sliding operation and the resonance yaw operation have a small effect on the twisting motion of the first mass portion 10, and can reduce the adverse effect on the reflection angle of the first mass portion 10. This action can be similarly seen in the 'V' spring.

It should be noted that a similar effect can be achieved by increasing the thickness and width of the 'I' spring. However, in such a case, not only a change in the resonance torsional frequency (for example, a phenomenon that the spring constant becomes unnecessarily too large, and thus a change in the resonance torsional frequency) 2 spring 61 and the bi-directional second spring 81 may cause a short circuit of a plurality of branched conductors.

For example,

The maximum current density of copper is 0.1 MA / cm ² (1 mA / μm ² ). In this case, the minimum line width of the wire above the spring is required to be 20 占 퐉 or more for a sufficiently large current (200 mA _rms ) to flow for driving the micro scanner using the electromagnetic force. Likewise, the minimum line width of the spring located at the lower portion of the conductor is also required to be at least 20 탆.

When the number of lines connected to the driving units 20 and 40 is three (slow axis axis driving) or two (fast axis axis driving) as in the embodiment, the spring width becomes thick and the torsional stiffness ) Is increased, which may lower the scan angle. In this case, the torsional rigidity of the spring can be greatly reduced by dividing the spring in parallel into a "W" shape or a "V" shape.

Fig. 19 shows the simulation result of the finite element analysis of the torsional stiffness.

Referring to FIG. 19, a spring structure having an 'I' shape (width: 60 μm, thickness: 50 μm, length: 2000 μm) and a W 'shape (width: 20 μm, thickness: 50 μm, The respective torsional stiffnesses can be known. When three wires are required, the torsional stiffness of the 'I' shape is 7.9424e-5 [Nm] and the torsional stiffness of the 'W' shape is 2.1322e-5.

FIG. 20 is a graph showing a scan angle. Referring to FIG. 20, it can be seen that the scan angle is significantly improved in the spring of the 'W' shape compared to the spring of the 'I' shape.

In summary, if the 'W' shape is used instead of the generally used 'I' shape, the spring stiffness of the rotation mode can be reduced to increase the rotation angle, and the spring stiffness of the sliding mode and the yawing mode can be increased You can reduce movement in unwanted directions.

Hereinafter, experimental results using the manufactured micro scanner will be described.

FIGS. 21 and 22 are views showing the resonance frequencies of the vertical and horizontal axes of the micro scanner.

Referring to FIG. 21, it can be seen that resonance occurs at 429 Hz at an input voltage of 100 mV and a current of 33 mA. Referring to FIG. 22, it can be seen that the resonance occurs at 1634 Hz at an input voltage of 200 mV and a current of 37 mV.

23 and 24 are graphs showing the twist angle of the vertical axis for each voltage Vpp in the static mode and the resonance mode on the vertical axis.

Referring to FIG. 23, in the static mode, the twist angle increases according to the voltage and increases to 9.06 degrees. Referring to FIG. 24, in the resonant mode, the twist angle increases according to the voltage and increases to 20.65 degrees.

25 is a graph showing the twist angle of the horizontal axis for each voltage Vpp in the resonance mode of the horizontal axis.

Referring to FIG. 25, it can be seen that the twist angle increases according to the voltage in the resonance mode to 50.55 degrees.

26 and 27 show the result of performing laser reflection in the case of driving only one axis among the horizontal axis and the vertical axis without driving the other axis. FIG. 26 shows a case where the horizontal axis is driven at 1.2 Vpp in the resonance mode, FIG. 27 shows a case where the vertical axis is operated in a static mode at 20 Vpp, and a torsional vibration occurs in each case.

28 to 30 are photographs in which the laser is reflected in a raster mode in which the vertical axis is a static mode and the horizontal axis is a resonance mode.

FIG. 28 shows a case where the vertical axis is operated at 20 Vpp and the horizontal axis at 0.8 Vpp. FIG. 29 shows a case where the vertical axis is operated at 20 Vpp and the horizontal axis is operated at 1.6 Vpp. FIG. 30 shows a case where the vertical axis is operated at 2.8 Vpp and the horizontal axis is operated at 20 Vpp , And the laser reflections were different in each case.

31 and 32 are photographs in which the laser is reflected in the Lissajous mode in which the vertical axis and the horizontal axis are set to the resonance mode.

FIG. 31 shows a case where the vertical axis is operated at 200 mVpp and the horizontal axis is operated at 2.8 Vpp. FIG. 32 shows a case where the vertical axis is 500 mVpp and the horizontal axis is operated at 2.8 Vpp.

As seen from the above experimental results, according to this embodiment, various laser reflection angles can be realized.

In the above embodiment, by providing the second mass portion 300 of the circular shape, that is, the donut shape, no electromagnetic force is generated in the driving portion even if current flows through the electric wire placed in the second mass portion 300. The second mass part 300 is provided with a plurality of connection parts including a spring, which enables dynamic amplification.

Other embodiments for further enhancing the above advantages will be described.

33 is a plan view of a micro scanner according to another embodiment.

The other embodiment is characterized in that the electric wire provided to the driving part and the second mass part is provided in a double line. By providing the electric wire as a double wire in the driving section, the required current for obtaining the same torque can be reduced.

In the following description of the drawings, parts that are not specifically described can be applied as they are with changes in the scope of the description of the original embodiment, and only the parts which are characteristically different in the case of the other embodiments will be described. In addition, one place is described symmetrically, and the same explanation applies to symmetric places.

Referring to FIG. 33, electric wires supplying electric current to the first driving part 20 are vertically separated and provided as a pair, and the first-first electric wire 75 and the first-second electric wire 76 are provided.

The first wire (75) is configured to rotate the first driving part (20) and the second mass part (300) twice in the same direction as shown. So that the Lorentz force as the current in the same direction can be doubled when compared to the original embodiment. Specifically, the first wire (75) can rotate the first driving part (20) and the second mass part (300) by 180 degrees.

The providing direction of the 1-1 wire 75 can be understood more clearly through an enlarged view of FIG. 33E shown in FIG.

Referring to FIGS. 33 and 34, the first wire 75 is first extended 90 degrees in the counterclockwise direction in the second mass part 300, and the first unidirectional second spring 611 Enters the first driving part 20 and extends in the clockwise direction by 180 degrees from the first driving part 20. Thereafter, the second mass part 300 is further extended 180 degrees counterclockwise, then again through the second unidirectional second spring 612 into the first driving part 20 and extended 180 degrees.

As a result of the above arrangement of the conductors, the first driving section 20 is provided with two conductors, that is, the 1-1-1 active conductors 77 and the 1-1-2 active conductors 78, Three leads may be provided at the first and second connection portions 300 and 300. The first connection portion 751, the first connection portion 752, and the 1-2-3 connection portion 753 may be provided at the first connection portion 300 and the second connection portion 300, respectively.

According to the extension path as described above, the first driving part 20 is provided with two electric wires running in the same direction to generate an electromagnetic force. Similarly, although the second mass portion 300 is provided with two electric wires, it does not generate an electromagnetic force as described in the first embodiment.

The first 1-2 wire 76 on the lower side may be provided with a similar shape symmetrically.

The second electric wire 95 is configured to rotate the second mass part 300 once twice in the same direction as the second driving part 40 as shown in the figure. Hence, the Lorentz force can be doubled when compared with the original embodiment by the current in the same direction.

The generation direction of the second electric wire 95 can be clearly understood through an enlarged view of FIG. 33F shown in FIG.

Referring to FIGS. 33 and 35, the second wire 95 drawn in is branched into left and right portions, and the second driving portion 40 is extended 180 degrees in different directions. Thereafter, the second electric wire 65 enters the second mass part 300 and rotates 180 degrees, and is again drawn out after the second driving part 40 is extended by 180 degrees.

As a result of the arrangement of the conductors, the second driving unit 20 is provided with two conductors, that is, the 2-1 active conductors 96 and the 2-2 active conductors 97, and the second mass unit 300 And one lead, which is the (2-1) connecting portion 951, may be provided.

According to the extension path as described above, the second driving part 40 is provided with two electric wires running in the same direction, thereby generating an electromagnetic force. Similarly, the second mass portion 300 is provided with one electric wire, but does not generate the electromagnetic force as described in the first embodiment.

The same type of wire on the opposite side of the branch can be provided symmetrically.

According to another embodiment of the present invention, the structure of the substrate is the same as that of the first embodiment, and the wires of the first driver and the second driver are all provided in a multi-turn . Therefore, the torque of both the driving portions can be increased.

According to another embodiment of the present invention, there is a disadvantage in that the metal layer 210 must be provided in multiple layers, for example, two layers in order to allow the wiring of the conductive wires to ride over each other without being short- In operation, a larger torque can be provided with the same current.

When the metal layer 210 is provided in multiple layers, the following process may be further provided. First, a metal layer 210 provided in a predetermined structure is provided in the first embodiment, an insulating layer is laid on the metal layer 210, and the insulating layer is patterned to provide a via structure. A multilayered metal layer can be obtained by providing a patterned seed layer again and conducting electroplating again.

Such another embodiment may be more preferably applied in the case of a micro scanner in which a large force is desired.

According to the present invention, a larger reflection angle of the first mass portion with respect to both axes can be realized with a low current by using dynamic amplification and multi-turn. Accordingly, the scanning range of the laser scanner can be increased.

10: First mass part
300: Second mass part

Claims (17)

A first mass portion having a reflective layer on one surface thereof;
A first driving unit provided at an outer periphery of the first mass part at the same center as the first mass part;
A second mass portion provided at an outer portion of the first driving portion apart from the first driving portion and coaxially with the first mass portion;
A one-way first spring and a one-way second spring provided in one direction so as to connect the first driving portion to the first mass portion and the second mass portion, respectively;
A second driving unit provided at an outer periphery of the second mass unit at the same center as the first mass unit;
A stationary frame placed on an outer side of the second driving unit;
A bi-directional first spring and a bi-directional second spring provided in opposite directions crossing the one direction so as to connect the second driving portion with the second mass portion and the fixed frame, respectively;
A first electric wire provided to the first driving unit and through which a current supplied from the outside flows;
A second electric wire provided to the second driving unit and through which a current supplied from the outside flows; And
And a magnetic field generating unit disposed below the first driving unit and the second driving unit and spaced apart from each other by a predetermined distance,
A reinforcing portion for suppressing dynamic deformation of the first mass portion is provided on the opposite surface of the first mass portion on which the reflective layer is provided,
Wherein the reinforcing portion is provided in the same material as the first electric wire and the second electric wire. The method according to claim 1,
Wherein the magnetic field generating portion includes three magnets having the same center,
The three magnets,
Wherein the polarities cross at a predetermined interval so that the two polarity opposite in polarity in the radial direction and having the maximum magnetic flux and a single symmetric line in which the magnetic flux is zero in the radial direction. 3. The method of claim 2,
Wherein the first wire and the second wire are aligned with two symmetrical lines having the maximum magnetic flux,
And the second mass part is aligned with one meshing line where the magnetic flux is zero. The method according to claim 1,
Wherein the current flowing through the first driving unit flows in the same direction about the axis when the one direction is the axis. The method according to claim 1,
And the current flowing through the second driving unit flows in the same direction about the axis when the direction is the axis. The method according to claim 1,
Wherein the electric wire placed in the first driving part and the electric wire placed in the second driving part are both provided in a double line. The method according to claim 1,
Wherein the first mass portion is provided in a circular shape or an elliptical shape. The method according to claim 1,
Wherein at least one of the one-way first spring, the one-way second spring, the first bi-directional spring, and the bi-directional second spring is provided in at least one of a 'V' shape and a 'W' shape. delete The method according to claim 1,
Wherein the reinforcing portion is provided in one of an orthogonal cross, a diagonal cross, a circle, a symmetrical rectangle, and a combination of two or more thereof. delete Providing an insulating film on the upper side of the SOI substrate and the lower side of the SOI substrate;
Providing a patterned metal layer over the SOI substrate;
Selectively removing the upper portion of the SOI substrate except for the metal layer by a DRIE process to provide a substrate structure for the micro-scanner;
Removing a lower portion of the SOI substrate by an etching process to provide a depression; And
Providing a reflective layer on said depressed surface,
Wherein the reinforcing portion is provided together with the metal layer to suppress the dynamic strain of the electric wire and the moving first mass portion when the metal layer is provided. 13. The method of claim 12,
Wherein the metal layer is provided by electroplating. 14. The method of claim 13,
Wherein the metal layer is provided in a laminated structure having a via structure. delete delete delete

Images