Galvano mirror and method for manufacturing the same

Abstract

The galvanometer mirror (100) includes a mirror surface (1) having a front surface (1a) serving as a mirror surface and a planar back surface (1b), a reinforcing plate (2) provided on the back surface (1b) side of the mirror surface (1) and separated from the back surface (1b), a plurality of core materials (3) including a foam core (3a) and a honeycomb core (3b) that are sandwiched between the mirror surface (1) and the reinforcing plate (2) and fixed to the back surface (1b) of the mirror surface (1), and a mirror fixing portion (4) that is sandwiched between the mirror surface (1) and the reinforcing plate (2) and formed of a material different from the core material (3). Among the mirror surface (1), the reinforcing plate (2), the core material (3), and the mirror fixing portion (4), adjacent members are fixed via an adhesive layer (5), and the mirror surface (1), the reinforcing plate (2), the core material (3), and the mirror fixing portion (4) are integrated.

Description

Technical Field

[0001] The present disclosure relates to a galvanometer mirror of a galvanometer scanner used in a laser processing machine or the like and a method for manufacturing the galvanometer mirror.

Background Art

[0002] With the increasing integration of substrates for mobile phones and electronic devices, higher precision and higher speed of processing by a laser processing machine are required. In a laser processing machine for performing drilling on a substrate, a galvanometer scanner for deflecting and driving a laser is used, and for higher speed of processing by the laser processing machine, higher speed of the galvanometer scanner is essential.

[0003] A conventional galvanometer scanner generally includes a stator having a coil, a rotor having a permanent magnet and a rotor shaft, and a galvanometer mirror attached to the rotor shaft. The stator is fixed to a housing or the like, the driving torque generated by the coil is received by the permanent magnet, the rotor rotates, and the galvanometer mirror rotates. While the rotor rotates continuously, the galvanometer mirror rotates within a range of ± ten-odd degrees from a reference position.

[0004] When applying a galvanometer scanner to a laser processing machine that continuously performs drilling on a substrate, acceleration → deceleration → stop is repeated, and when the galvanometer scanner is operated at high speed, the frequency of the driving current becomes high. For this reason, eddy currents flow in the permanent magnet, eddy current loss occurs, and the temperature of the permanent magnet rises. When the temperature of the permanent magnet becomes excessively high, thermal demagnetization occurs, the magnet characteristics deteriorate, and the operation of the galvanometer scanner is hindered.

[0005] In addition, when the galvanometer scanner is operated at high speed, the load on the galvanometer mirror and the rotor shaft increases. Therefore, it is necessary to firmly fix the galvanometer mirror to the rotor shaft so that the galvanometer mirror and the rotor shaft do not shift. Conventionally, a mirror fixing portion into which a part of the rotor shaft fits is provided on the galvanometer mirror side, and a structure in which the galvanometer mirror is mechanically fixed to the rotor shaft has been adopted. However, in this structure, when fixing the galvanometer mirror and the rotor shaft, strain occurs in the mirror fixing portion, and the strain in the mirror fixing portion is transmitted to the mirror surface of the galvanometer mirror, causing strain in the mirror surface of the galvanometer mirror. As a result, the accuracy of the mirror surface of the galvanometer mirror deteriorates, and the processing accuracy deteriorates.

[0006] In view of such a situation, Patent Document 1 discloses a galvanometer mirror that suppresses deterioration of the accuracy of the mirror surface when fixing the galvanometer mirror and the rotor shaft. In the technique disclosed in Patent Document 1, a low-density and high-rigidity metal material such as beryllium is used for the material of the galvanometer mirror provided with a mirror surface having optical characteristics, a mirror fixing portion for fixing the mirror surface and the rotor shaft, and a rib as a reinforcing structure. By making a cut in a portion of the rib close to the mirror fixing portion, the strain of the mirror fixing portion is made difficult to be transmitted to the mirror surface of the galvanometer mirror, and the strain generated on the mirror surface of the galvanometer mirror is reduced.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the technology disclosed in Patent Document 1, by making a cut in the portion of the rib close to the mirror fixing portion, the rigidity of the cut portion is reduced. Therefore, when the galvanometer mirror is driven at high speed, there is a problem that the vibration of the galvanometer mirror increases and the displacement of the processing position occurs. In order to reduce such vibration, it is necessary to reduce the weight of the galvanometer mirror and lower the inertia. However, in order to reduce the weight of the galvanometer mirror, it is necessary to make the rib and the mirror surface thinner. However, when the mirror surface is thinned, the rigidity difference between the portion where the rib exists on the back surface of the mirror surface and the portion where it does not exist becomes prominent. The portion where the rib exists is polished because a load is applied during the mirror surface polishing process due to its high rigidity, while the portion where the rib does not exist is difficult to be polished because it bends and the load during the mirror surface polishing process escapes. As a result, there is a problem that the mirror surface cannot be polished uniformly and the mirror surface cannot be processed to the desired flatness. In addition, when the mirror surface is thinned, the rigidity of the mirror surface is reduced, and deformation is likely to occur during the driving of the galvanometer mirror, so there is also a problem that it becomes difficult to increase the speed of the galvanometer scanner.

[0009] The present disclosure has been made in view of the above, and an object thereof is to obtain a galvanometer mirror that can realize weight reduction and a highly accurate mirror surface while ensuring rigidity that is difficult to deform.

Means for Solving the Problems

[0010] In order to solve the above-described problems and achieve the object, the galvanometer mirror according to the present disclosure includes a mirror surface, a reinforcing plate, a plurality of types of core materials, and a mirror fixing portion. The mirror surface has a front surface that serves as a mirror surface and a back surface having a planar shape facing the opposite side of the front surface. The reinforcing plate is provided on the back surface side of the mirror surface away from the back surface. The plurality of types of core materials are sandwiched between the mirror surface and the reinforcing plate and are fixed to the back surface of the mirror surface, a foam-like core and Facing away from the mirror surface and fixed to the back of the form coreIt includes a honeycomb core. The mirror fixing part is arranged sandwiched between the mirror surface and the reinforcing plate, formed of a material different from the core material, and fixes the galvanometer mirror to other members. The mirror fixing part has a gripping part for gripping other members. The gripping part is exposed from the mirror surface and the reinforcing plate. Adjacent members among the mirror surface, the reinforcing plate, the core material, and the mirror fixing part are fixed via an adhesive layer, and the mirror surface, the reinforcing plate, the core material, and the mirror fixing part are integrated.

Effect of the Invention

[0011] The galvanometer mirror according to the present disclosure can achieve the effect of ensuring rigidity that is difficult to deform while realizing a lightweight and highly accurate mirror surface.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Mode for Carrying Out the Invention

[0013] Hereinafter, a galvanometer mirror and a method for manufacturing a galvanometer mirror according to an embodiment will be described in detail with reference to the drawings.

[0014] Embodiment 1. FIG. 1 is a side view showing a galvanometer mirror 100 according to Embodiment 1. FIG. 2 is a side view showing a state in which the constituent members of the galvanometer mirror 100 according to Embodiment 1 are separated. FIG. 3 is a perspective view showing the galvanometer mirror 100 according to Embodiment 1. FIG. 4 is a rear view showing the galvanometer mirror 100 according to Embodiment 1. The galvanometer mirror 100 constitutes a galvanometer scanner together with a stator, a rotor, etc. (not shown) and is a member that reflects a laser beam (not shown). The galvanometer mirror 100 rotates within a specific range of deflection angles due to the rotation of the rotor. When the galvanometer mirror 100 rotates, the irradiation position of the laser beam on a workpiece (not shown) can be changed. As shown in FIGS. 1 and 2, the galvanometer mirror 100 includes a mirror surface 1, a reinforcing plate 2, a plurality of types of core materials 3, a mirror fixing portion 4, and an adhesive layer 5. In the following description, the length direction of the galvanometer mirror 100 is defined as the X-axis direction, the thickness direction of the galvanometer mirror 100 is defined as the Y-axis direction, and the width direction of the galvanometer mirror 100 is defined as the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are directions perpendicular to each other.

[0015] As shown in Fig. 2, the mirror surface 1 is a plate-like member having a front surface 1a that is a mirror surface and a back surface 1b having a planar shape facing the opposite side of the front surface 1a. No reinforcing structure such as ribs provided conventionally is formed on the back surface 1b itself. The mirror surface 1 is preferably formed of a material having a high specific elastic modulus (GPa·cm 3 / g), which is a value obtained by dividing the elastic modulus by the density (bulk specific gravity), and good mirror polishing workability. Specifically, the mirror surface 1 is preferably formed of a plate of any one of alumina, sapphire, boron carbide, silicon nitride, aluminum nitride, silicon carbide, B4C-TiB2, beryllium ceramics, or a wafer of any one of single-crystal silicon carbide and single-crystal silicon, or a single-crystal silicon wafer. For example, when using a single-crystal silicon carbide wafer for the mirror surface 1, after trimming the single-crystal silicon carbide wafer, mirror polishing (mirror polish) is performed to obtain the mirror surface 1 that has been made into a mirror surface. The thickness of the mirror surface 1 is preferably less than 1 mm, and more preferably 400 μm or less.

[0016] The reinforcing plate 2 is a plate-like member provided on the back surface 1b side of the mirror surface 1 so as to be separated from the back surface 1b. The reinforcing plate 2 is preferably formed of a material having a small bulk specific gravity and high rigidity. Specifically, the material of the reinforcing plate 2 is preferably carbon fiber reinforced plastic (CFRP: Carbon Fiber Reinforced Plastics) using carbon fibers having an elastic modulus of 600 GPa or more. The specific elastic modulus as carbon fiber reinforced plastic is preferably 100 or more. The thickness of the reinforcing plate 2 is preferably less than 1 mm. It is preferable that the bulk specific gravity of the reinforcing plate 2 is less than 1.85 g / cm 3 and the elastic modulus of the reinforcing plate 2 is 120 GPa or more.

[0017] A plurality of types of core materials 3 are arranged sandwiched between the mirror surface 1 and the reinforcing plate 2, and include a foam core 3a and a honeycomb core 3b. The types of core materials 3 are two types, namely, the foam core 3a and the honeycomb core 3b, in this embodiment.

[0018] The foam core 3a is a plate-like member fixed to the back surface 1b of the mirror surface 1. The foam core 3a is a plate material obtained by foaming a hard plastic or the like. The foam core 3a is preferably formed of a material having isotropic properties like a rigid plastic closed-cell foam. Specifically, the material of the foam core 3a is preferably a material having a small bulk specific gravity and an elastic modulus / (bulk specific gravity)^3 value of 100 GPa or more, such as ROHACELL 110HP manufactured by EVONIK, and more preferably a closed-cell structural material. Also, the material of the foam core 3a may be graphoform which is a carbon foam, or a foam-like material having a bulk specific gravity of less than 0.4 g / cm 3 Hereinafter, as long as it is a foam-like material having an elastic modulus / (bulk specific gravity)^3 value of 100 GPa or more, it may be a metal, ceramics, or the like. As the material of the core material 3 fixed to the back surface 1b of the mirror surface 1, the foam core 3a is more preferable than a structural material having a large density difference in a large space at the visual level like the honeycomb core 3b. The thickness of the foam core 3a is preferably 2 mm or more and less than 10 mm, and more preferably less than 5 mm. The bulk specific gravity of the foam core 3a is less than 0.4 g / cm 3 and it is preferable that the elastic modulus of the foam core 3a is 0.1 GPa or more. As shown in FIG. 3, a notch portion 3c into which a part of the mirror fixing portion 4 is fitted is formed at one end of the foam core 3a in the X-axis direction.

[0019] As shown in FIG. 2, the honeycomb core 3b is a plate-like member provided between the foam core 3a and the reinforcing plate 2. The honeycomb core 3b is preferably formed of carbon fiber reinforced plastic or the like. Specifically, the material of the honeycomb core 3b is preferably a material having a high specific elastic modulus, such as honeycomb UCF-137-3 / 8-10 manufactured by Ultracor. The bulk specific gravity of the honeycomb core 3b is preferably less than 0.2 g / cm 3 and the specific elastic modulus of the honeycomb core 3b is preferably 10 or more. The thickness of the honeycomb core 3b is preferably 3 mm or more and less than 15 mm, and more preferably less than 10 mm. As shown in FIG. 3, a notch 3d into which a part of the mirror fixing portion 4 fits is formed at one end of the honeycomb core 3b in the X-axis direction.

[0020] As shown in FIG. 1, the mirror fixing portion 4 is disposed between the mirror surface 1 and the reinforcing plate 2 and is a portion for fixing the galvanometer mirror 100 to other members (not shown). The other member is, for example, a rotor shaft. The mirror fixing portion 4 is formed of a material different from that of the core material 3. As shown in FIG. 3, the mirror fixing portion 4 is fitted into the notch 3c of the foam core 3a and the notch 3d of the honeycomb core 3b. The mirror fixing portion 4 is disposed adjacent to the foam core 3a and the honeycomb core 3b in the X-axis direction and the Z-axis direction. The mirror fixing portion 4 is preferably formed of a material having a small bulk specific gravity and a high elastic modulus. Specifically, the material of the mirror fixing portion 4 is a composite of silicon carbide and carbon fiber, such as C / SiC (bulk specific gravity: 2.95 g / cm 3 , elastic modulus: 350 GPa), with a bulk specific gravity of less than 4 g / cm 3 and an elastic modulus of 300 GPa or more and a specific elastic modulus of 100 or more. In addition to C / SiC, the material of the mirror surface 1 may also be ceramics such as alumina, boron carbide, silicon nitride, aluminum nitride, silicon carbide, and B4C-TiB2.

[0021] The mirror fixing portion 4 has a gripping portion 4a for gripping other members. The gripping portion 4a is exposed from the mirror surface 1 and the reinforcing plate 2 without being covered by the mirror surface 1 and the reinforcing plate 2. The shape of the gripping portion 4a is rectangular in the present embodiment, but is not particularly limited. If other members are directly gripped (fixed) by the mirror surface 1 and the reinforcing plate 2, it is not preferable because the strain generated when the galvanometer mirror 100 and other members are fixed is likely to be transmitted to the mirror surface 1. However, in the present embodiment, since other members are directly gripped by the gripping portion 4a exposed from the mirror surface 1 and the reinforcing plate 2, the strain generated when the galvanometer mirror 100 and other members are fixed is less likely to be transmitted to the mirror surface 1.

[0022] Each adhesive layer 5 shown in FIG. 2 is a layer for fixing adjacent members among the constituent members of the galvanometer mirror 100. That is, adjacent members among the mirror surface 1, the reinforcing plate 2, the core material 3, and the mirror fixing portion 4 are fixed via the adhesive layer 5, and the mirror surface 1, the reinforcing plate 2, the core material 3, and the mirror fixing portion 4 are integrated. The adhesive layer 5 is, for example, a film-shaped adhesive made of a resin sheet or a liquid adhesive. The number of the adhesive layers 5 is three in the present embodiment. When distinguishing the three adhesive layers 5, they are referred to as a first adhesive layer 5a, a second adhesive layer 5b, and a third adhesive layer 5c. The first adhesive layer 5a fixes the back surface 1b of the mirror surface 1, the foam core 3a, and the mirror fixing portion 4. The second adhesive layer 5b fixes the foam core 3a and the honeycomb core 3b. The third adhesive layer 5c fixes the honeycomb core 3b, the mirror fixing portion 4, and the reinforcing plate 2.

[0023] As shown in FIGS. 3 and 4, the external shape of the galvanometer mirror 100 is generally elliptical (oval shape) in this embodiment, but it may be changed as appropriate. Each component member of the galvanometer mirror 100 has an outer periphery processed into a curved surface shape or a tapered shape, and an adhesive surface adhered to an adjacent member is processed into a planar shape. FIG. 5 is a cross-sectional view taken along the line V-V shown in FIG. 4. As shown in FIG. 5, the XY cross-sectional shape of the galvanometer mirror 100 is a trapezoidal shape in which the area of the reinforcing plate 2 is smaller than the area of the mirror surface 1 in this embodiment, but it may be changed as appropriate. Note that in FIG. 5, the illustration of the mirror fixing portion 4 is omitted.

[0024] Next, with reference to FIGS. 6 to 8, a method for manufacturing the galvanometer mirror 100 according to Embodiment 1 will be described. FIG. 6 is a flowchart showing an example of a manufacturing process of the galvanometer mirror 100 according to Embodiment 1. FIG. 7 is a diagram showing an example of a manufacturing process of the mirror surface 1 in Embodiment 1. FIG. 8 is a diagram showing an example of an assembly procedure of the galvanometer mirror 100 according to Embodiment 1.

[0025] The method for manufacturing the galvanometer mirror 100 includes a preparation step, a fixing step, a film formation step, and a coating step.

[0026] The preparation step is a step of preparing the mirror surface 1, a plurality of types of core materials 3, the reinforcing plate 2, and the mirror fixing portion 4. As shown in FIG. 6, in the preparation step, a mirror surface formation step, a foam core formation step, a honeycomb core formation step, a reinforcing plate formation step, and a mirror fixing portion formation step are performed.

[0027] In the mirror surface forming process, a single crystal ingot 1c such as SiC shown in FIG. 7 is prepared (step S11), and the single crystal ingot 1c is sliced to obtain a wafer 1d (step S12). A plurality of wafers 1d are obtained from one single crystal ingot 1c. Further, in the mirror surface forming process, each wafer 1d is trimmed so as to have a desired shape (step S13) to obtain a trimming member 1e. A plurality of trimming members 1e are obtained from one wafer 1d. Thereafter, a mirror polishing process of mirror-polishing each trimming member 1e is performed by a lapping device or the like (step S14). Thereby, a mirror-finished mirror surface 1 is obtained.

[0028] In the foam core forming process shown in FIG. 6, a bulk material obtained by foaming a hard plastic or the like is sliced to a predetermined thickness (step S21), and then the bulk material is trimmed according to the shape of the mirror surface 1 (step S22). Thereby, a foam core 3a is obtained. Since the bulk material is a low-density foam material that has been foamed, the bulk material can be easily processed with an ordinary processing machine.

[0029] Also, in the honeycomb core forming process, a honeycomb material formed of carbon fiber reinforced plastic or the like is sliced to a predetermined thickness (step S31), and then the honeycomb material is trimmed according to the shape of the foam core 3a (step S32). Thereby, a honeycomb core 3b is obtained.

[0030] In the reinforcing plate forming process, a plate is formed using high-rigidity carbon fiber (step S41), and then the plate is trimmed according to the shape of the mirror surface 1 (step S42). Thereby, a reinforcing plate 2 is obtained.

[0031] In the mirror fixing portion forming process, ceramics are block-molded to obtain a bulk material (step S51), and then the bulk material is trimmed (step S52). Thereby, a mirror fixing portion 4 is obtained.

[0032] The fixing process (step S61) is a process of fixing adjacent members among the mirror surface 1, the reinforcing plate 2, the core material 3, and the mirror fixing portion 4 shown in FIG. 8 with an adhesive layer 5 to integrate the mirror surface 1, the reinforcing plate 2, the core material 3, and the mirror fixing portion 4. In the fixing process, the mirror surface 1, the first adhesive layer 5a, the foam core 3a, the second adhesive layer 5b, the honeycomb core 3b, the mirror fixing portion 4, the third adhesive layer 5c, and the reinforcing plate 2 are laminated in this order. Specifically, in the fixing process, first, a mirror surface 1 is prepared as shown in the upper left of FIG. 8. Subsequently, the first adhesive layer 5a is applied to the back surface 1b of the mirror surface 1. Subsequently, the foam core 3a is fixed to the back surface 1b of the mirror surface 1 via the first adhesive layer 5a.

[0033] Subsequently, as shown in the upper center of FIG. 8, the second adhesive layer 5b is applied to the surface of the foam core 3a that faces away from the first adhesive layer 5a. Subsequently, the honeycomb core 3b is fixed to the foam core 3a via the second adhesive layer 5b. Subsequently, the mirror fixing portion 4 is disposed in the notch portion 3c of the foam core 3a and the notch portion 3d of the honeycomb core 3b, and the mirror fixing portion 4 is disposed on the exposed surface 5d of the first adhesive layer 5a, and the mirror fixing portion 4 is fixed to the back surface 1b of the mirror surface 1 via the first adhesive layer 5a. The exposed surface 5d of the first adhesive layer 5a is a portion exposed through the notch portions 3c and 3d.

[0034] Subsequently, as shown in the upper right of FIG. 8, the third adhesive layer 5c is applied to the surface of the honeycomb core 3b that faces away from the second adhesive layer 5b and the surface of the mirror fixing portion 4 that faces away from the first adhesive layer 5a. Subsequently, the reinforcing plate 2 is disposed on the side opposite to the honeycomb core 3b and the mirror fixing portion 4 with the third adhesive layer 5c interposed therebetween. Subsequently, the reinforcing plate 2 is fixed to the honeycomb core 3b and the mirror fixing portion 4 via the third adhesive layer 5c. Thereby, the mirror surface 1, the reinforcing plate 2, the foam core 3a, the honeycomb core 3b, and the mirror fixing portion 4 are integrated. The first adhesive layer 5a, the second adhesive layer 5b, and the third adhesive layer 5c are film-like adhesives made of resin sheets here.

[0035] The film forming process (step S62) shown in FIG. 6 is a process of depositing a metal-based material on the mirror surface of the mirror surface 1 or coating the mirror surface by sputtering to form a film on the mirror surface after the fixing process. That is, the film forming process is a process of performing an antireflection coating. The film is a metal film.

[0036] The coating process (step S63) is a process of further coating the dielectric multilayer film on the film of the mirror surface. That is, the coating process is a process of performing an antireflection coating. By performing the film forming process and the coating process, the reflectivity of the mirror surface of the mirror surface 1 can be increased. By performing the above processes, the galvanometer mirror 100 shown in FIG. 1 is manufactured.

[0037] Next, the effects of the galvanometer mirror 100 according to Embodiment 1 will be described.

[0038] First, referring to FIGS. 9 to 12, the galvanometer mirrors 200 and 300 according to the prior art will be described. FIG. 9 is a perspective view showing an example of a galvanometer mirror 200 formed of a single material according to the prior art. FIG. 10 is a perspective view showing a deformed state of the galvanometer mirror 200 shown in FIG. 9 after mirror polishing. FIG. 11 is a perspective view showing a deformed state of a sandwich-structured galvanometer mirror 300 according to the prior art. FIG. 12 is an enlarged view of part A shown in FIG. 11. In the galvanometer mirror 200 according to the prior art shown in FIG. 9, weight reduction is achieved by grinding the back surface 230 of the mirror surface 210. On the other hand, on the back surface 230 of the mirror surface 210, a rib 240 is provided, which includes a backbone structure portion 250 extending in the X-axis direction at the center in the Z-axis direction and a plurality of rib reinforcement portions 260 extending from the backbone structure portion 250 toward the outer peripheral edge of the mirror surface 210, thereby reducing the decrease in the rigidity of the galvanometer mirror 200 due to weight reduction. In the conventional galvanometer mirror 200, when mirror polishing the front surface 220 of the mirror surface 210 after performing weight reduction processing on the back surface 230 of the mirror surface 210, the rigidity of the mirror surface 210 becomes non-uniform due to the influence of the rib 240. Therefore, a difference occurs in the amount of deflection due to the surface pressure of the mirror polishing between the portion where the rib 240 exists and the portion where it does not exist. The portion where the rib 240 exists is polished because it has high rigidity, while the portion where the rib 240 does not exist is difficult to be polished because it has low rigidity and bends. As a result, the dimple 270 shown in FIG. 10 occurs, and a highly accurate mirror surface cannot be obtained. On the other hand, in the galvanometer mirror 200 according to the prior art, when performing weight reduction processing on the back surface 230 of the mirror surface 210 after mirror polishing the mirror surface 210, strain occurs during the weight reduction processing, and the accuracy of the mirror surface of the mirror surface 210 deteriorates. Therefore, a highly accurate mirror surface cannot be obtained. That is, in the galvanometer mirror 200 according to the prior art, it is impossible to achieve both weight reduction and high accuracy of the mirror surface.

[0039] Also, as shown in FIG. 11, when the galvanometer mirror 300 has a sandwich panel structure, in order to reduce the weight, a honeycomb core 320 with a large cell size and a low core density is sandwiched between two thin surface plates 310 to form a sandwich panel structure. When the surface plate 310 and the honeycomb core 320 are fixed, they are affected by adhesion. As a result, as shown in FIG. 12, dimples 330 tracing the cell pattern of the honeycomb core 320 are generated on the surface plate 310, and the accuracy of the mirror surface of the surface plate 310 decreases. In order to solve the decrease in the accuracy of the mirror surface, it is necessary to reduce the cell size of the honeycomb core 320 and increase the density, or increase the thickness of the surface plate 310 to increase the rigidity of the surface plate 310. However, if this is done, the weight of the galvanometer mirror 300 increases. That is, in the galvanometer mirror 300 according to the prior art, it is impossible to achieve both weight reduction and high-precision mirror surface.

[0040] In this regard, in the present embodiment, as shown in FIG. 2, since the back surface 1b of the mirror surface 1 is planar, the mirror surface 1 alone can be mirror-polished, and a highly accurate mirror surface can be easily obtained. And in the present embodiment, the back surface 1b of the mirror surface 1 that has been preliminarily thinned and mirror-polished is reinforced with a lightweight and highly rigid foam core 3a, and then further reinforced with a honeycomb core 3b with a low core density, thereby reducing the weight of the galvanometer mirror 100 while preventing a decrease in the accuracy of the mirror surface due to deformation of the mirror surface 1. That is, in the present embodiment, it is possible to achieve both weight reduction and high-precision mirror surface.

[0041] In the present embodiment, as shown in FIG. 1, the galvanometer mirror 100 has a sandwich structure in which a foam core 3a that is light and highly rigid, an ultra-lightweight honeycomb core 3b formed of carbon fiber reinforced plastic, and a mirror fixing portion 4 formed of ceramics are sandwiched between a mirror surface 1 formed of ceramics having a high specific modulus of elasticity and a reinforcing plate 2 formed of carbon fiber reinforced plastic having a high specific modulus of elasticity. With such a structure, it is possible to obtain a galvanometer mirror 100 that can realize weight reduction and a highly accurate mirror surface while ensuring high rigidity that is difficult to deform.

[0042] In the present embodiment, since the mirror fixing portion 4 shown in FIG. 1 is formed of a material different from the core material 3, the physical properties become discontinuous. Therefore, the strain generated when the galvanometer mirror 100 and other members are fixed is difficult to be transmitted to the mirror surface 1 via the core material 3, and the deterioration of the accuracy of the mirror surface of the mirror surface 1 can be reduced. In addition, since a large adhesive area between the mirror fixing portion 4 and the core material 3 can be ensured, the strain generated at the boundary between the mirror fixing portion 4 and the mirror surface 1 during the driving of the galvanometer mirror 100 can be reduced.

[0043] In the present embodiment, as shown in FIG. 1, the galvanometer mirror 100 can be manufactured by adhering and integrating the mirror surface 1, the reinforcing plate 2, the two types of core materials 3, and the mirror fixing portion 4. Therefore, complicated processing for weight reduction becomes unnecessary, and the galvanometer mirror 100 can be manufactured by simple processing and manufacturing processes. In particular, since the mirror surface 1 alone can be mirror-polished, the mirror-polishing process can be realized by a simple process, and a highly accurate mirror surface can be obtained.

[0044] In the present embodiment, when the mirror surface 1 shown in FIG. 1 is a sapphire plate, a single-crystalline silicon carbide wafer, or a single-crystalline silicon wafer, compared with the case of obtaining the mirror surface 210 (see FIG. 9) by performing weight reduction processing and mirror polishing on a bulk material such as silicon carbide or beryllium as in the prior art, a thin and light mirror surface 1 can be obtained, and the accuracy of the mirror surface of the mirror surface 1 can be easily increased.

[0045] In the present embodiment, since the adhesive layer 5 shown in FIG. 2 is a film-shaped adhesive, fine displacement of the adhesive surfaces of the respective constituent members can be absorbed, so that the outer dimensions of the respective constituent members after adhesion are stabilized, and a galvanometer mirror 100 with high dimensional accuracy can be obtained.

[0046] Next, a modified example of the galvanometer mirror 100 according to Embodiment 1 will be described.

[0047] The shape of the gripping portion 4a shown in FIG. 3 was rectangular in the present embodiment, but may be, for example, cylindrical or have the cylindrical shape shown in FIG. 13. FIG. 13 is a perspective view showing the galvanometer mirror 100 according to Modified Example 1 of Embodiment 1. Note that FIG. 13 shows a state in which the galvanometer mirror 100 is inverted up and down on the paper surface from the state shown in FIG. 3.

[0048] The XY cross-sectional shape of the galvanometer mirror 100 shown in FIG. 5 was trapezoidal in the present embodiment, but when the overall thickness of the galvanometer mirror 100 is thin, for example, when it is 5 mm or less, it may have a rectangular shape or the like shown in FIG. 14. Note that FIG. 14 is a view showing the cross-sectional shape of the galvanometer mirror 100 according to Modified Example 2 of Embodiment 1, and corresponds to a cross-sectional view taken along the line V-V shown in FIG. 4. In FIG. 14, the illustration of the mirror fixing portion 4 is omitted.

[0049] Next, the effects of the present disclosure will be further described with reference to Examples and Comparative Examples.

[0050] (Example 1) The galvanometer mirror according to Example 1 has a sandwich structure in which a foam core, a honeycomb core, and a mirror fixing portion are sandwiched between a mirror surface and a reinforcing plate. A Si wafer was used for the mirror surface constituting the surface of the galvanometer mirror. ROHACELL 110HP manufactured by EVONIC was used for the foam core. Honeycomb UCF-137-3 / 8-10 manufactured by Ultracor was used for the honeycomb core. DIALEAD k63712 was used for the reinforcing plate constituting the back surface of the galvanometer mirror, and a CFRP plate formed with a fiber content of 60% and a fiber orientation of 0 / 90 degrees was used. A C / SiC material was used for the mirror fixing portion. Adjacent members were fixed to each other using a 100-μm-thick film adhesive, and the mirror surface, the reinforcing plate, the foam core, the honeycomb core, and the mirror fixing portion were integrated. Note that the detailed dimensions of each member were set to be equivalent to the inertia of the galvanometer mirror according to Comparative Example 1.

[0051] (Comparative Example 1) The galvanometer mirror according to Comparative Example 1 is composed of a single material. Specifically, the galvanometer mirror according to Comparative Example 1 was obtained by subjecting a sintered SiC material to weight reduction processing and then mirror polishing to make it mirror-like. The outer shape of the galvanometer mirror according to Comparative Example 1 is the same as the shape shown in FIG. 9. The detailed dimensions are omitted.

[0052] (Comparative Example 2) The galvanometer mirror according to Comparative Example 2 has a configuration in which only one type of honeycomb core is sandwiched as a core material between two CFRP plates on the front and back. The same material as the reinforcing plate of Example 1 was used for the CFRP plates. The same honeycomb UCF-137-3 / 8-10 manufactured by Ultracor as the honeycomb core of Example 1 was used for the honeycomb core. Adjacent members were fixed to each other using a 100-μm-thick film adhesive, and the two CFRP plates and the honeycomb core were integrated. Note that in Comparative Example 2, the plate thickness of the CFRP plate and the thickness of the honeycomb core were set so that the amount of deformation during driving of the galvanometer mirror would be about the same as that of the galvanometer mirror according to Comparative Example 1.

[0053] (Comparative Example 3) The galvanometer mirror according to Comparative Example 3 was configured in the same manner as in Example 1, except that the core material was only one type of foam core.

[0054] (Test Method) Regarding the galvanometer mirrors of the above Example 1 and Comparative Examples 1 to 3, evaluations were made on weight, inertia, mirror surface accuracy, and amount of deformation during driving (high rigidity: difficulty of deformation). Regarding the amount of deformation during driving, each galvanometer mirror was incorporated into a galvanometer scanner, and the amount of deformation of the mirror surface of the galvanometer mirror when the galvanometer scanner was driven at the maximum acceleration was obtained by finite element analysis.

[0055] Table 1 is a table showing the evaluation results of the galvanometer mirrors according to Example 1 and Comparative Examples 1 to 3. In Table 1, the numerical values of each evaluation item are expressed as indices with the numerical value of the galvanometer mirror of Comparative Example 1 being 100. The smaller the numerical value of each evaluation item, the better the characteristics of each evaluation item.

[0056]

Table 1

[0057] As is clear from Table 1, in Comparative Example 2, when the rigidity was designed so that the amount of deformation during driving was equivalent to that of Comparative Example 1, the weight and inertia were reduced to less than 50% of those of Comparative Example 1, but the accuracy of the mirror surface deteriorated to about 1.5 times that of Comparative Example 1. This is due to the dimples generated on the surface of the CFRP plate (see Fig. 11). To eliminate the generation of dimples, it is necessary to make the thickness of the CFRP plate 3 to 4 times thicker than that of Comparative Example 2. However, if this is done, the weight and inertia will be more than twice that of Comparative Example 1. Furthermore, even if the generation of dimples is eliminated, in the case of the CFRP plate, due to the influence of the curing shrinkage of the resin during molding, the accuracy of the molding surface becomes insufficient. In addition, since the molding surface is a mixture of two types of materials, resin and fiber, even if mirror polishing is performed on the molding surface, sufficient surface roughness cannot be obtained and the molding surface cannot be made into a mirror surface. As a method of mirroring the molding surface, there is a method of covering the molding surface with a single material and performing mirror polishing again. However, if this is done, the weight and inertia will become even larger, and when metallization or the like is performed, bimetal deformation will occur in the galvanometer mirror, which is not preferable.

[0058] In Comparative Example 3, there is no reinforcing structure on the back surface of the Si wafer, and since no weight reduction process is performed on the back surface of the Si wafer, the accuracy of the mirror surface is better than that of Comparative Example 1. Also, in Comparative Example 3, although the weight is reduced compared to Comparative Example 1, since the overall thickness of the galvanometer mirror is thicker than that of Comparative Example 1, the inertia becomes larger than that of Comparative Example 1. In addition, since the rigidity of the foam core is lower than that of the honeycomb core and the rigidity of the entire core is insufficient, the amount of deformation during driving becomes larger than that of Comparative Example 1. To reduce the amount of deformation during driving, it is necessary to increase the thickness of the foam core. However, if this is done, the weight will become larger than that of Comparative Example 1. Furthermore, the inertia also becomes larger, and when driving with the same galvanometer motor, the driving speed of the galvanometer mirror decreases, which is not preferable.

[0059] In Example 1, when designed such that the inertia is equivalent to that of Comparative Example 1, the weight, the accuracy of the mirror surface, and the amount of deformation during driving were all reduced compared to Comparative Example 1. That is, when the galvanometer mirror of Example 1 is mounted on a laser processing machine or the like, high-precision and high-speed processing can be realized.

[0060] The configurations shown in the above embodiments are merely examples, and it is also possible to combine them with other known technologies, and it is also possible to omit or change a part of the configuration without departing from the gist.

[0061] Hereinafter, various aspects of the present disclosure will be summarized and described as appendices.

[0062] (Appendix 1) A mirror surface having a front surface that becomes a mirror surface and a planar back surface facing the opposite side of the front surface, A reinforcing plate provided away from the back surface on the back surface side of the mirror surface, A plurality of types of core materials including a foam core and a honeycomb core that are sandwiched between the mirror surface and the reinforcing plate and fixed to the back surface of the mirror surface, A mirror fixing portion that is sandwiched between the mirror surface and the reinforcing plate, is formed of a material different from the core material, and is for fixing the galvanometer mirror to other members, Comprising, Among the mirror surface, the reinforcing plate, the core material, and the mirror fixing portion, adjacent members are fixed via an adhesive layer, and the mirror surface, the reinforcing plate, the core material, and the mirror fixing portion are integrated. A galvanometer mirror characterized by this. (Appendix 2) On the mirror surface, a plate of any one of ceramics such as alumina, sapphire, boron carbide, silicon nitride, aluminum nitride, silicon carbide, B4C-TiB2, beryllium, or a wafer of any one of single-crystalline silicon carbide and single-crystalline silicon, or The galvanometer mirror according to Appendix 1, characterized in that a single-crystalline silicon wafer is used. (Supplementary Note 3) The types of the core materials are two types, namely the foam core and the honeycomb core, the bulk specific gravity of the foam core is less than 0.4 g / cm 3 and the elastic modulus of the foam core is 0.1 GPa or more, the bulk specific gravity of the honeycomb core is less than 0.2 g / cm 3 and the specific elastic modulus of the honeycomb core is 10 or more, the galvanometer mirror according to Supplementary Note 1 or 2, characterized in that. (Supplementary Note 4) The material of the reinforcing plate is carbon fiber reinforced plastic, the bulk specific gravity of the reinforcing plate is less than 1.85 g / cm 3 and the elastic modulus of the reinforcing plate is 120 GPa or more, the galvanometer mirror according to any one of Supplementary Notes 1 to 3, characterized in that. (Supplementary Note 5) The material of the mirror fixing portion is a ceramic having a specific elastic modulus of 100 or more, the galvanometer mirror according to any one of Supplementary Notes 1 to 4, characterized in that. (Supplementary Note 6) A galvanometer mirror manufacturing method comprising: a mirror surface having a front surface that becomes a mirror surface and a planar back surface facing the opposite side of the front surface; a reinforcing plate provided away from the back surface on the back surface side of the mirror surface; a plurality of types of core materials including a foam core and a honeycomb core that are sandwiched between the mirror surface and the reinforcing plate and are fixed to the back surface of the mirror surface; and a mirror fixing portion that is sandwiched between the mirror surface and the reinforcing plate, is formed of a material different from that of the core material, and is for fixing the galvanometer mirror to another member, a fixing step of fixing adjacent members among the mirror surface, the reinforcing plate, the core material, and the mirror fixing portion with an adhesive layer to integrate the mirror surface, the reinforcing plate, the core material, and the mirror fixing portion; After the fixing step, a film forming step of depositing a metal-based material on the mirror surface of the mirror surface or coating the mirror surface by sputtering to form a film on the mirror surface; A coating step of further coating the film on the mirror surface with a dielectric multilayer film; A method for manufacturing a galvanometer mirror, comprising the steps of: (Appendix 7) The method for manufacturing a galvanometer mirror according to Appendix 6, further comprising a mirror finishing step of mirror-polishing the front surface of the mirror surface before the fixing step. (Appendix 8) The method for manufacturing a galvanometer mirror according to Appendix 6 or 7, wherein the adhesive layer is a film-shaped adhesive made of a resin sheet.

Explanation of symbols

[0063] 1,210 mirror surface, 1a,220 front surface, 1b,230 back surface, 1c single crystal ingot, 1d wafer, 1e trimming member, 2 reinforcing plate, 3 core material, 3a foam core, 3b,320 honeycomb core, 3c,3d notch, 4 mirror fixing portion, 4a gripping portion, 5 adhesive layer, 5a first adhesive layer, 5b second adhesive layer, 5c third adhesive layer, 5d exposed surface, 100,200,300 galvanometer mirror, 240 rib, 250 backbone structure portion, 260 rib reinforcement portion, 270,330 dimple, 310 surface plate.

Claims

1. A mirror surface having a front surface that acts as a mirror and a back surface that has a planar shape facing the opposite direction from the front surface, A reinforcing plate is provided on the rear side of the mirror surface, away from the rear surface, A plurality of core materials, including a foam core and a honeycomb core, are sandwiched and positioned between the mirror surface and the reinforcing plate and fixed to the back surface of the mirror surface. A mirror fixing portion is positioned sandwiched between the mirror surface and the reinforcing plate, formed from a material different from the core material, and is used to fix the galvanic mirror to another member. Equipped with, The mirror fixing portion has a gripping portion for gripping the other member, The gripping portion is exposed from the mirror surface and the reinforcing plate. A galvanic mirror characterized in that adjacent members of the mirror surface, reinforcing plate, core material, and mirror fixing portion are fixed together via an adhesive layer, and the mirror surface, reinforcing plate, core material, and mirror fixing portion are integrated together.

2. The galvanometer mirror according to claim 1, characterized in that the mirror surface is made of a ceramic plate of alumina, sapphire, boron carbide, silicon nitride, aluminum nitride, silicon carbide, B4C-TiB2, or beryllium, or a wafer of single-crystal silicon carbide, single-crystal silicon, or a single-crystal silicon wafer.

3. The core material can be of two types: the foam core and the honeycomb core. The bulk density of the aforementioned foam core is 0.4 g / cm³. 3 Less than and the elastic modulus of the foam core is 0.1 GPa or more. The bulk density of the aforementioned honeycomb core is 0.2 g / cm³. 3 The galvanometer mirror according to claim 1, characterized in that it is less than and the specific modulus of elasticity of the honeycomb core is 10 or more.

4. The material of the reinforcing plate is carbon fiber reinforced plastic. The bulk density of the reinforcing plate is 1.85 g / cm³. 3 The galvanometer mirror according to claim 1, characterized in that it is less than and the modulus of elasticity of the reinforcing plate is 120 GPa or more.

5. The galvanometer mirror according to any one of claims 1 to 4, characterized in that the material of the mirror fixing part is a ceramic with a specific modulus of 100 or more.

6. A method for manufacturing a galvanometer mirror, comprising: a mirror surface having a mirror-like front surface and a planar back surface facing the opposite direction from the front surface; a reinforcing plate provided on the back side of the mirror surface, away from the back surface; a plurality of core materials, including a foam core and a honeycomb core, sandwiched between the mirror surface and the reinforcing plate and fixed to the back surface of the mirror surface; and a mirror fixing portion, sandwiched between the mirror surface and the reinforcing plate and formed of a material different from the core materials, for fixing the galvanometer mirror to another member, wherein the mirror fixing portion has a gripping portion for gripping the other member, and the gripping portion is exposed from the mirror surface and the reinforcing plate. A fixing step in which adjacent members of the mirror surface, the reinforcing plate, the core material, and the mirror fixing part are fixed together with an adhesive layer, thereby integrating the mirror surface, the reinforcing plate, the core material, and the mirror fixing part; After the fixing step, a coating step is performed in which a metal-based material is deposited onto the mirror surface of the mirror surface or the mirror surface is coated with sputter to form a coating on the mirror surface, A coating step is to further coat the aforementioned coating on the mirror surface with a dielectric multilayer coating, A method for manufacturing a galvanometer mirror, characterized by including the following:

7. The method for manufacturing a galvanic mirror according to claim 6, characterized in that it includes a mirror polishing step of mirror polishing the front surface of the mirror surface before the fixing step.

8. The method for manufacturing a galvanometer mirror according to claim 6 or 7, characterized in that the adhesive layer is a film-like adhesive made of a resin sheet.

Images