KR100931324B1 - Thin film 2-axis driving mirror for laser display and manufacturing method - Google Patents

Abstract

The present invention relates to a thin-film biaxial driving mirror for a laser display and a method of manufacturing the same. More particularly, the shape of the cantilever beam is adopted in the shape of the cantilever beam by selecting one of a rhombus, an ellipse, and a diamond with a sharp tip. Since it becomes an ellipse at the mirror surface when entering the cantilever beam surface at the driving angle of 45 °, the effective light area is increased, the air resistance is low, the damping coefficient is small when resonance, and both surfaces of the chemical mechanical polishing (CMP) By using a silicon wafer that has been plasma-treated without a mask for a short time, the microscopic pores at the molecular level are formed on the surface of the silicon where the mechanically rotated and polished marks are generated to relieve residual stresses and to be more reliable than other wafers with polishing marks remaining. Cantilever The front surface of the beam is formed of a thin film, and the coil conductor is formed on the rear surface of the cantilever beam, so that the light efficiency can be improved by increasing the fill factor through enhancing the reflection efficiency. By forming a thin lip shape, it is possible to drive not only flatness but also stable and reliable driving, and by changing the dimensions and shape of the torsion bar of the connecting part of the driving mirror and coating a low friction protective film, The present invention relates to a thin-film two-axis driving mirror for laser display and a method of manufacturing the same that can protect the surface of the cantilever beam while increasing friction and reducing friction.

Thin film type biaxial drive mirror for laser display according to the present invention comprises: a drive mirror chip formed by thin-film processing an SOI wafer subjected to plasma treatment after both surfaces are chemically and mechanically polished; A cantilever beam having a sharp diamond shape, diamond shape, or ellipse having a sharp blade tip formed in the driving mirror chip; Two first torsion bars on the axis of rotation of the cantilever beam and connected at both ends thereof; A horizontal axis drive cantilever beam formed outside the cantilever beam and connected by the two first torsion bars; Two second torsion bars on the axis of rotation of the horizontal axis drive cantilever beam and connected at both ends thereof; A drive mirror chip substrate connected by the two second torsion bars; A coil lead wire positioned at a rear portion of the cantilever beam and configured to flow a current; A printed circuit board or a ceramic substrate mounted on the driving mirror chip to be seated and fixed by a fixing member; A magnetic field line induction frame connected to and supported by a printed circuit board or a ceramic substrate to which the driving mirror chip is fixed; A magnet mounted inside the magnetic force line induction frame and inducing magnetic force lines by having two pairs having different polarities facing each other at intervals so as to be symmetrical with respect to the rotation axis of the torsion bar; An outer case protecting and supporting a driving mirror chip including the cantilever beam, a printed circuit board or a ceramic substrate, and a magnetic force line induction frame to which a magnet is coupled; Characterized by including.

Description

Mirror with thin film type second axis for the laser display and fabrication method

The present invention adopts any one of the shape of the cantilever beam among the rhombus, ellipse, and diamond shape having a sharp tip, so that the laser beam becomes an ellipse in the cantilever beam when the laser beam is incident at an angle of 45 ° to the surface of the cantilever beam driven by the vertical axis. Mechanically rotated and polished by using a thin film of plasma-treated silicon film for a short time on both surfaces of the chemical mechanical polishing (CMP) wafer with high air resistance, low air resistance and low damping coefficient at resonance. Molecular level micropores are formed on the surface where the marks are generated to relieve residual stresses, and the driving mirrors are more reliable and robust than other wafers with polishing marks.The front surface of the cantilever beam is formed of a thin film and coiled. Conducting wires are formed on the back of the cantilever beam, increasing reflection efficiency. Through this, the fill factor can be increased to improve the light efficiency.As it forms a thin lip on the back of the cantilever beam of the horizontal axis driving, the flatness as well as the stable driving stability can be achieved. By changing the dimensions and shape of the torsion bar of the connecting portion of the cantilever beam and coating a low friction protective film, it is possible to increase the resonant frequency, reduce the friction and protect the surface of the cantilever beam. And a technique relating to the production method thereof.

An example of a conventional MEMS type driving mirror for a laser display is as follows.

As shown in FIG. 1, a constant power driving mirror, which is Korean Patent Application Publication No. 2006 (No. 64219), is coated with an insulator on a lower portion of the first silicon 150 and then patterned to form an air-gap having a depth of 8 μm. ) Wells, embedding and flattening electrodes in the second silicon substrate 250, and then bonding the first silicon substrate and the second silicon substrate by anodic bonding or the like, and chemically mechanically bonding the second silicon substrate to a thickness of 20 탆. After polishing and planarization, the second silicon top is patterned and etched to form drive mirrors and electrode shapes. The structure of the driving mirror is simpler and cheaper than the SOI process, and the fill factor is high. However, since the thickness of the air gap is limited, damping is easily caused due to air resistance.

As shown in FIGS. 2A and 2B, the electromagnetic force driving mirror 11 of the Republic of Korea Patent Application Publication No. 84307 (2006) is composed of a permanent magnetic material 15 and a magnetic generating coil on the rear of the mirror. In the frame 12 for suppressing the deformation of the mirror and a hole for mass reduction are formed. However, such an electromagnetic force driving mirror is disadvantageous in obtaining a large driving angle due to the limited size of the permanent magnetic material, and has a problem in that the resonance frequency of the driving mirror falls due to the mass of the frame.

There is also a uniaxial or biaxial electromagnetic force driving mirror of Nippon Signal, Japan, which is a driving mirror for a conventional laser scanner.

As shown in FIG. 3, the electromagnetic force driving mirror for the laser scanner includes a reflection mirror 1 having a reflective metal layer at the center of the cantilever portion, a coil lead portion 2 through which current flows around the driving mirror, and a driving mirror amount. The drive torsion bar 4 is located on the side, and the permanent magnet 5 is located on both sides of the wafer level drive mirror chip. When a current is applied to the coil lead 2 outside the reflecting mirror 1 of the cantilever 3 inside the permanent magnet 5 of the drive mirror, the cantilever axis the torsion bar 4 by the Lorentz force. Rotational drive is used to change the path of the laser light. When an alternating current is applied at the resonant frequency of the driving mirror of several kHz, it is alternately driven at a large angle. The laser light is scanned on the screen by scanning two driving mirrors or one driving mirror for driving the vertical axis and the horizontal axis.

Referring to FIG. 3 and FIG. 4, the conventional electromagnetic force driving mirror used an SOI wafer 10. The SOI wafer is bonded together with the silicon oxide 8 between the first silicon wafer 7 and the second silicon wafer 9 which are manufactured by chemical mechanical polishing (CMP). The SOI wafer is chemically mechanically mechanically polished (CMP) due to the mechanical rotation of the etching marks are formed on the wafer surface to increase the residual stress. Therefore, there is a problem that the SOI wafer can be easily destroyed by external impact even during the process or after the final product is manufactured.

Referring to FIG. 3, the conventional electromagnetic force driving mirror is a reflection mirror 1 and a coil conductor 2 through which current flows around the reflection mirror 1, so that the conventional electromagnetic force driving mirror is an SOI wafer. Increasing the number of windings of the coil to increase the first silicon wafer driving angle by using the laser beam reduces the fill factor of the driving mirror, thereby reducing the light efficiency, and the cantilever beam 3 is subjected to friction of the torsion bar 4 when driving the kHz. There is a problem in that it is difficult to drive and the durability is poor.

Therefore, when the laser beam enters the cantilever beam surface at an angle of 45 ° to the cantilever beam surface of the vertical axis, the effective light area is increased, the air resistance is low, the damping coefficient is small during resonance, and the mechanically rotated and polished marks are generated. Molecular-level micropores are formed on the surface to relieve residual stress, and are more reliable and robust than the other wafers with polishing marks, and have higher fill factor through increased reflection efficiency. Thin film type 2-axis driving mirror for laser display that can improve efficiency, ensure flatness as well as stable and robust driving, and increase the resonant frequency and reduce friction while protecting the surface of the cantilever beam. The development of is urgently needed.

Accordingly, the present invention has been conceived to solve the above problems, by adopting any one of the shape of the cantilever beam of the pointed rhombus, ellipse, diamond shape, the laser beam at a 45 ° angle to the surface of the cantilever beam of the vertical axis drive It is an object of the present invention to provide a thin-film two-axis driving mirror for laser display and a method of manufacturing the same because it becomes an ellipse at the surface of the cantilever beam at the time of incidence, thereby increasing the effective optical area, the low air resistance, and the low damping coefficient at resonance.

Another object of the present invention is to use a silicon thin film that is plasma treated without a mask for a short time on both surfaces of the chemical mechanically polished wafer surface, thereby forming a microscopic pore at the molecular level on the surface where the mechanically rotated and polished marks have occurred, thereby remaining stress. The present invention provides a thin-film two-axis driving mirror for laser display and a method of manufacturing the same, which has more reliable and robust driving mirror characteristics than other wafers with polishing marks remaining.

Another object of the present invention is to form a thin film on the front of the cantilever beam, the coil lead is formed on the back of the cantilever beam, laser display that can improve the light efficiency by increasing the fill factor through the reflection efficiency enhancement To provide a thin-film two-axis driving mirror and a method for manufacturing the same.

Another object of the present invention is to form a thin lip on the back of the cantilever beam of the horizontal axis driving during driving, the thin film type 2-axis driving mirror for laser display that can be stable and robust driving as well as flatness during driving and its manufacture To provide a method.

Another object of the present invention is to change the dimensions and shape of the torsion bar of the connection portion of the cantilever beam and to coat the low friction protective film, thereby increasing the resonant frequency, reducing the friction force and at the same time protect the surface of the cantilever beam To provide a thin-film two-axis driving mirror and a method for manufacturing the same.

Laser display thin film biaxial driving mirror according to a preferred embodiment of the present invention for achieving the above object is a driving mirror chip 20 formed by thin-film processing the SOI wafer subjected to plasma treatment after both surfaces are chemically mechanically polished and ; A cantilever beam 30 having a sharp diamond shape, a diamond shape, or an oval shape having a sharp blade tip formed in the driving mirror chip 20; Two first torsion bars (31) on the axis of rotation of said vertical axis drive cantilever beam and connected at both ends thereof; A horizontal axis drive cantilever beam 32 formed outside the vertical axis drive cantilever beam and connected by the two first torsion bars 31; Two second torsion bars (33) on the axis of rotation of the horizontal axis drive cantilever beam and connected at both ends thereof; A drive mirror chip substrate 34 connected by the two second torsion bars; A coil lead wire 40 positioned at the rear portions of the vertical and horizontal axis driving cantilever beams 30 and 32 so as to flow current; and placing the driving mirror chip 20 so as to be seated thereon, and fixing members 51. A printed circuit board or a ceramic substrate 50 which can be fixed by; A magnetic field line induction frame 60 connected and supported by a printed circuit board or a ceramic substrate 50 to which the driving mirror chip 20 is fixed; A magnet 70 mounted inside the magnetic force line induction frame 60 and inducing magnetic force lines by facing two pairs having different polarities so as to be symmetrical with respect to the rotation axes of the torsion bars 31 and 33, respectively; Protecting and supporting the magnetic force line induction frame 60 to which the driving mirror chip 20 including the cantilever beams 30 and 32, the printed circuit board or the ceramic substrate 50, and the magnet 70 are coupled. Exterior case 80; Characterized by including.

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In addition, a method of manufacturing a thin film biaxial driving mirror for a laser display according to a preferred embodiment of the present invention for achieving the above object comprises the steps of plasma treatment on both sides of the SOI wafer; Depositing an oxide film, applying a photoresist and fabricating a first coil lead on the SOI wafer; Fabricating a photoresist and fabricating a second coil lead on the SOI wafer; Forming an electrode on the SOI wafer; Forming and etching a cantilever beam shape on the SOI wafer; Etching a silicon layer under the SOI wafer to form a cantilever beam; Forming a reflection surface of the cantilever beam and performing flip chip bonding; Characterized by including.

In the present invention, in the step of depositing an oxide film, applying a photoresist, and fabricating a first coil lead on the SOI wafer, anodic bonding of one silicon wafer on which the oxide film is deposited and the other silicon wafer is performed. Oxide films are deposited on the top and bottom of the mechanically polished SOI wafer, and then a negative photoresist (PR) is applied to the top surface of the wafer to form a pattern, and chromium (Cr), copper (Cu), and gold (Au) are deposited. ) Is sequentially thermally deposited, followed by lift-off to generate a first coil lead, and then depositing an oxide film on the first coil lead.

In the present invention, in the step of forming a photoresist coating and a second coil lead on the SOI wafer, a negative photoresist (PR) is applied to the upper surface of the SOI wafer to form a pattern, chromium (Cr), Thermally depositing copper (Cu) and then gold (Au), and then generating a second coil lead by lift-off, and then depositing an oxide film on the second coil lead. .

In the present invention, in the step of forming and etching the cantilever beam shape on the SOI wafer, a photoresist is applied to form a pattern, dry etching the oxide film, and at the same time opening a pad portion and then top silicon. Etching by using the RIE equipment characterized in that it comprises forming the shape of the cantilever beam.

In the present invention, in the step of forming the cantilever beam by etching the silicon layer on the lower part of the wafer, after forming an oxide hard mask on the back side of the SOI wafer, the silicon layer on the back side of the SOI wafer is etched and then dried using a dry etching method. And release the cantilever beam to move freely.

In the present invention, in forming the reflective surface of the cantilever beam and flip chip bonding, after depositing the silicon layer of the etched cantilever beam under the wafer with aluminum (Al) to form the reflective surface of the mirror, Forming a ball with a wire bonder (wire bonder) on the pad (pad) portion and then dicing the wafer (dic), characterized in that it comprises flip-chip bonding (flip-chip bonding).

The thin-film biaxial driving mirror for a laser display according to the present invention and a manufacturing method thereof have the following effects.

First, the present invention is effective because the laser beam becomes an ellipse at the mirror surface when the laser beam is incident at a 45 ° angle to the cantilever beam surface of the vertical axis drive by adopting any one of a pointed rhombus, an ellipse, and a diamond shape in the shape of a cantilever beam. High light area, low air resistance and low damping coefficient at resonance.

Second, the present invention uses a silicon thin film that is plasma-treated on both sides of a chemical mechanically polished wafer surface without a mask for a short time, thereby forming a microscopic pore of molecular level on the surface on which mechanically rotated and polished marks are generated, thereby reducing residual stress. It solves the problem and has a more reliable and robust driving mirror characteristic than other wafers with polishing marks remaining.

Third, in the present invention, the cantilever beam on the front surface of the cantilever is formed of a thin film, and the coil lead wire is formed on the rear surface of the cantilever beam, so that the light efficiency can be improved by increasing the fill factor through reflection efficiency enhancement.

Fourth, the present invention forms a thin lip on the rear surface of the cantilever beam of the horizontal axis drive, it is possible to drive not only flatness but also stable and robust reliable driving.

Fifth, the present invention can change the dimensions and shape of the torsion bar of the connection portion of the cantilever beam, and by coating a low friction protective film, it is possible to protect the surface of the cantilever beam while increasing the resonant frequency, reduce the frictional force.

Looking at the preferred embodiment of the present invention together with the accompanying drawings as follows, when it is determined that the detailed description of the known art or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention The description will be omitted, and the following terms are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or custom, and the definitions thereof are defined by the present invention. It should be made based on the contents throughout the present specification for explaining the manufacturing method.

5 is a perspective view showing the shape of a thin film dual axis driving mirror for a laser display according to an embodiment of the present invention, Figure 6 is an exploded thin film type biaxial driving mirror for a laser display according to an embodiment of the present invention Figure 7 is an exploded perspective view showing the shape, Figure 7 is a front view showing the shape of the thin-film biaxial driving mirror for laser display according to an embodiment of the present invention.

5 to 7, the thin-film biaxial driving mirror for a laser display according to an embodiment of the present invention is a driving mirror formed by thin-film processing an SOI wafer subjected to plasma treatment after both surfaces are chemically and mechanically polished. A chip 20; A lozenge, diamond, or elliptical cantilever beam having a sharp tip of a vertical axis drive formed in the driving mirror chip 20; Two first torsion bars (31) on the axis of rotation of said vertical axis drive cantilever beam and connected at both ends thereof; A horizontal axis drive cantilever beam 32 formed outside the vertical axis drive cantilever beam and connected by the two first torsion bars 31; Two second torsion bars (33) on the axis of rotation of the horizontal axis drive cantilever beam and connected at both ends thereof; A drive mirror chip substrate 34 connected by the two second torsion bars; A coil lead wire positioned at a rear portion of the cantilever beams 30 and 32 for driving the vertical and horizontal axes so as to flow current; A printed circuit board or ceramic substrate 50 mounted on the driving mirror chip 20 to be seated thereon and fixed by the fixing member 51; A magnetic field line induction frame 60 connected and supported by a printed circuit board or a ceramic substrate 50 to which the driving mirror chip 20 is fixed; A magnet 70 mounted inside the magnetic force line induction frame 60 and inducing magnetic force lines by facing two pairs having different polarities so as to be symmetrical with respect to the rotation axes of the torsion bars 31 and 33, respectively; Protecting and supporting the magnetic force line induction frame 60 to which the driving mirror chip 20 including the cantilever beams 30 and 32, the printed circuit board or the ceramic substrate 50, and the magnet 70 are coupled. Exterior case 80; It is provided.

When the current is applied to the coil conductor located at the outermost part of the back of the cantilever beam, the technical functions of the thin film 2-axis driving mirror for driving the torsion bar by the Lorentz force will be described as follows.

The driving mirror chip 20 is formed by penetrating up and down a thin silicon substrate subjected to plasma treatment after both surfaces are chemically and mechanically polished.

The cantilever beams 30 and 32 are formed in the driving mirror chip 20 and are symmetrically connected to the two torsion bars 31 and 33. Here, when the torsion bars 31 and 33 connected to the cantilever beams 30 and 32 are formed in the same horizontal axis and the vertical axis, respectively, the driving angle and the residual angle remain with respect to the same input current value according to the change of the shape of the torsion bar 31. Looking at the table and the relationship that can be seen that the stress is changed as follows.

Next, in the case where the torsion bars 31 connected to the cantilever beam 30 are formed in the same vertical axis, the driving angle and the residual stress of the same DC input current value are changed according to the change of the shape of the torsion bar 31. The change is noticeable: the thickness of the silicon formed in the cantilever beam and torsion bar is 50 μm, the length of the torsion bar is 1.2 mm, and the line width is 0.18 mm.

Table 1. Change of driving angle and residual stress according to the change of torsion bar shape (vertical axis).

In addition, according to the change of the shape of the torsion bar 33 connected to the cantilever beam 32 of the horizontal axis drive, it is possible to know the change of the driving angle and the residual stress for the same DC input current value, which is connected to the frame before the shape change. The length of the torsion bar is 0.8mm, the line width is 0.3mm, and after the change, if the tip of the torsion bar is formed wider than the middle part, the residual stress is reduced.

Table 2. Change of driving angle and residual stress according to the change of the torsion bar shape (horizontal axis).

As described above, as the shape of the torsion bars 31 and 33 connected to the cantilever beams 30 and 32 changes, the driving angle and the residual stress are reduced with respect to the same input current value.

The following is the equation of motion for the cantilever beam when an alternating current is applied.

In Equation 1, θ of the left side term is the driving angle of the cantilever beam having the torsion bars 31 and 33 as the drive shaft, J is the inertia moment of the cantilever beam, c is the damping coefficient, and K _t is the Torsional spring constant. The right side term is the rotational force term by Lorentz force, proportional to the applied current i _D , and A is a constant. In Equation 2, i _p is a direct current bias current and i _d is an amplitude of an alternating current. In Equation 3, θ _s is a drive angle of the cantilever beam by DC bias, and θ _a is an angle driven by AC current.

The following equation (4) is the driving angle relationship of the cantilever beam derived from (1), (2), (3).

W _r in Equation 5 is the resonance frequency, and Equation 6 represents the input AC current and the maximum driving angle at the resonance frequency.

The following equations (7) and (8) are related to damping coefficients of the cantilever beam.

Where μ is air viscosity, D is the width of the cantilever beam in a direction perpendicular to the drive axis, L _m is the length of the cantilever beam parallel to the drive axis, and h _o is the air gap of the cantilever beam. gap), and b = D / L _m .

As can be seen from the above relations, the smaller the damping coefficient is, the larger the driving angle is. In the present invention, the damping coefficient is small and the driving mirror can increase the driving angle. If the width D is small compared to the length L _m , the damping coefficient becomes very small.

Therefore, the present invention is a thin-film two-axis drive mirror chip for laser display has an elliptical structure with a sharp tip of the cantilever beam 30 of the vertical axis drive driven at a high frequency, the damping coefficient is small and obtains the maximum driving angle and at the same time light efficiency It is a structure that enlarges. Since the width of the cantilever beam 30 is shorter than the length, the damping coefficient is reduced. In addition, the tip of the wing in the driving direction has the effect of splitting air and having a larger effective light area for reflecting an elliptical laser beam.

The coil leads (not shown) are positioned at the rear portions of the cantilever beams 30 and 32 so that current flows.

The printed circuit board or the ceramic substrate 50 may be mounted on the driving mirror chip 20 so as to be seated thereon and fixed by the fixing member 51. The fixing member 51 is most preferably using a bolt, pins, etc. may be possible.

The magnetic field line induction frame 60 is connected and supported by a printed circuit board or ceramic substrate 50 to which the driving mirror chip 20 is fixed.

The magnet 70 is mounted inside the magnetic force line induction frame 60 and induces magnetic force lines by facing two pairs having different polarities so as to be symmetrical with respect to the rotation axes of the torsion bars 31 and 33, respectively. . Here, the magnet 70 may be a conventional magnet, but it would be reasonable to use rare earth magnets of the Sm series and the Nd series with high strength of magnetic force and uniform magnetic density.

The case 80 is a magnetic force line induction frame 60 to which the chip 20 for the driving mirror including the cantilever beams 30 and 32, the printed circuit board or the ceramic substrate 50, and the magnet 70 are coupled. Protect and support

In addition, as shown in Figures 8 to 9t, the manufacturing process of the thin-film biaxial driving mirror for laser display according to an embodiment of the present invention will be described.

The first is the plasma treatment on both sides of the SOI wafer. In the above process, the SOI wafer that has been removed from the residual stress is rinsed in the surface of the SOI wafer with SF ₃ plasma after being cleaned in the hydrofluoric acid (HF) and HNO ₃ mixed solution to solve the residual stress of the mechanical polishing surface.

The second process is to deposit oxide film, PR coating and fabricate first coil lead on SOI wafer. In this process, oxide films are deposited on the top and bottom surfaces of the SOI wafer (FIG. 9A). At this time, the thickness of the oxide film is 0.5㎛, deposited using a PECVD (Plasma Enhanced Chemical Vapor Deposition) equipment, it is possible to use a variety of deposition equipment. Then, a photoresist (PR) is applied to the upper surface of the wafer by using a primary mask (FIG. 9D) to form a pattern, and chromium (Cr), copper (Cu), and gold (Au) are respectively 0.01, 0.4, Thermal evaporation to 0.1 μm thickness (FIG. 9B). The photoresist uses a negative photoresist dedicated to lift-off for forming an electrode. Next, an oxide film is deposited using a PECVD (Plasma Enhanced Chemical Vapor Deposition) apparatus. Next, an oxide film is deposited on the first coil lead (Fig. 9E), and the thickness of the oxide film is 0.5 mu m. Thereafter, an oxide film is formed to have a thickness of 0.5 μm to form a connection portion of the coil lead on the upper surface of the wafer using a secondary mask (FIG. 9G) (FIG. 9F).

The third step is to form a second coil lead and an electrode on the SOI wafer. In the above process, chromium (Cr), copper (Cu), and gold (Au) are 0.01, 0.4, and 0.1 μm thick by sputtering or evaporating on one side of the wafer using a tertiary mask (FIG. 9i). After the deposition in order, the second coil lead wire and the electrode is formed by performing a lift-off process in which an ultrasonic wave is put in an acetone solution (FIG. 9H).

The fourth step is to deposit an oxide film, form a cantilever beam, and etch on an SOI wafer. In this process, a nitride film is deposited to a thickness of 0.5 mu m to protect the wafer surface on the SOI wafer (FIG. 9J). After that, the cantilever beam shape is patterned using a fourth mask (FIG. 9M) and the pad part is opened (FIG. 9K). Subsequently, the upper silicon is etched by about 50 μm using an RIE device to form a cantilever beam shape (FIG. 9L).

Fifth, the silicon layer under the SOI wafer is etched to form a cantilever beam. In the above process, a photoresist is applied to the backside of the SOI wafer using a fifth mask (FIG. 9Q) to pattern the photoresist, and an oxide film is etched to form a hard mask for lip and cavity formation (FIG. 9N), and then silicon is dried by a dry etching method. Etch (Fig. 9O). After that, the structure is released using a dry etching method to secure a space for the cantilever beam to move freely (FIG. 9P).

Sixth is the process of forming the mirror reflection surface and flip chip bonding. In the above process, a silicon layer of the etched cantilever beam under the wafer is deposited with gold or aluminum (Al) to a thickness of 0.15 μm to form a mirror reflective surface (FIG. 9R), and then a protective coating is applied. The protective film increases the silicon oxide film or the reflectance. Alternatively, the protective film may be deposited by sputtering a similar diamond of low friction and low stress used in conventional Diamond Micro Electro Mechanical Systems (MEMS) technology. Next, a ball is formed on the pad by a wire bonder (Fig. 9s). Thereafter, the wafer is diced and flip-chip bonding is performed (FIG. 9T). After the above process, the chip for the driving mirror of the wafer is diced with a laser or the like to separate the chip for the driving mirror from the wafer to complete the final wafer-level driving mirror product.

As described above, various substitutions, modifications, and changes can be made by those skilled in the art without departing from the technical spirit of the present invention, and thus, the embodiments and the accompanying drawings are limited. It doesn't happen.

1 is a cross-sectional view of a conventional electrostatic driving mirror.

2A and 2B are perspective views of a conventional electrostatic driving mirror.

3 is a perspective view of a conventional laser application electromagnetic force driving mirror.

4 is a cross-sectional view taken along the line AA ′ of FIG. 3.

5 is a perspective view showing the shape of a thin-film two-axis driving mirror for laser display according to an embodiment of the present invention.

Figure 6 is an exploded perspective view showing the shape of the disassembled thin-film biaxial driving mirror for laser display according to an embodiment of the present invention.

Figure 7 is a front view showing the shape of the thin-film two-axis driving mirror for laser display according to an embodiment of the present invention.

8 is a manufacturing flow chart of a thin-film two-axis driving mirror for laser display according to an embodiment of the present invention.

9a to 9t are views showing a detailed manufacturing process of the thin-film two-axis driving mirror for laser display according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

20 ... chip for driving mirror 30 ... cantilever beam with vertical axis drive

31 ... torsion bar on vertical axis 32 ... cantilever beam with horizontal drive

33.Horizontal torsion bar

50 ... printed circuit board (ceramic board) 51 ... fixing member

60 ... magnetic field guide frame 70 ... magnet

80.Exterior case

Claims (8)

In thin film type 2-axis driving mirror for laser display, A driving mirror chip formed by thin-film processing an SOI wafer after both surfaces are chemically and mechanically polished; A lozenge, diamond, or elliptical cantilever beam having a sharp tip of a vertical axis drive formed in the driving mirror chip; Two first torsion bars on the axis of rotation of the cantilever beam of vertical drive and connected at both ends thereof; A horizontal axis drive cantilever beam formed outside the vertical axis drive cantilever beam and connected by the two first torsion bars; Two second torsion bars on the axis of rotation of the horizontal axis drive cantilever beam and connected at both ends thereof; A drive mirror chip substrate connected by the two second torsion bars; A coil lead wire positioned at a rear portion of the cantilever beam for driving the vertical axis and the horizontal axis to flow a current; A printed circuit board or a ceramic substrate mounted on the driving mirror chip to be seated and fixed by a fixing member; A magnetic field line induction frame connected to and supported by a printed circuit board or a ceramic substrate to which the driving mirror chip is fixed; A magnet mounted inside the magnetic force line induction frame and inducing magnetic force lines by having two pairs having different polarities facing each other at intervals so as to be symmetrical with respect to the rotation axis of the torsion bar; An outer case protecting and supporting a driving mirror chip including the cantilever beam, a printed circuit board or a ceramic substrate, and a magnetic force line induction frame to which a magnet is coupled; Thin-film two-axis driving mirror for laser display, characterized in that it comprises a. delete delete In the manufacturing method of the thin-film biaxial driving mirror for laser display, Plasma treating both sides of the SOI wafer; Depositing an oxide film, applying a photoresist and fabricating a first coil lead on the SOI wafer; Fabricating a photoresist and fabricating a second coil lead on the SOI wafer; Forming an electrode on the SOI wafer; Forming and etching a cantilever beam shape on the SOI wafer; Etching a silicon layer under the SOI wafer to form a cantilever beam; Forming a reflective surface of the cantilever beam and performing flip chip bonding; Method of manufacturing a thin-film two-axis driving mirror for laser display comprising a. The method of claim 4, wherein In the step of depositing an oxide film, applying a photoresist, and manufacturing a first coil lead on the SOI wafer, an oxide film is deposited on the top and bottom surfaces of the SOI wafer, and then a photoresist is applied to the top surface of the wafer to form a pattern. Fabrication of a thin film biaxial driving mirror for laser display, characterized in that after the thermal deposition of Cu (Cu) to produce a first coil lead by a lift-off, an oxide film is deposited on the first coil lead. Way. The method of claim 4, wherein In the forming and etching of the cantilever beam on the SOI wafer, an oxide film is deposited on the SOI wafer to protect the wafer surface, and then, the cantilever beam is formed, the pad part is opened, and then the cantilever beam is formed. A method of manufacturing a thin-film two-axis driving mirror for laser display, characterized in that the shape is etched using RIE equipment. The method of claim 4, wherein  In the step of forming the cantilever beam by etching the silicon layer under the wafer, after forming an oxide hard mask on the back side of the SOI wafer, the silicon layer on the back side of the SOI wafer is etched and then the structure is released using a dry etching method to free the cantilever beam. A method of manufacturing a thin film two-axis driving mirror for laser display, characterized in that to move. The method of claim 4, wherein In the step of forming a reflective surface on the surface of the cantilever beam and performing flip chip bonding, a silicon layer of an etched mirror and a frame under the wafer is deposited with aluminum (Al) to form a reflective surface, and then a pad portion. A method of manufacturing a thin film biaxial driving mirror for a laser display, comprising: forming a ball with a wire bonder and then flipping the wafer after dicing the wafer.

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