Displacement sensor and method for manufacturing a displacement sensor

Abstract

This invention provides a displacement sensor that allows for easy adjustment of the distance between the laser element and the mirror, even after the laser element has been mounted. [Solution] The displacement sensor comprises a first member, a second member provided on the first member and having an opening, a laser element provided on the upper surface of the first member within the opening and emitting laser light, a mirror provided on the side surface of the opening and reflecting the laser light, and a first photodetector that receives the reflected light reflected by the object from the laser light reflected by the mirror, wherein the first member and the second member are separate members.

Description

Technical Field

[0001] The present disclosure relates to a displacement sensor and a method for manufacturing the displacement sensor.

Background Art

[0002] Displacement sensors such as optical encoders or Doppler sensors are known, in which laser light emitted by a laser element is reflected by a mirror, and the reflected laser light is detected by a photodetector as reflected light reflected by a diffraction grating or a moving object (for example, Patent Documents 1 to 3). The member on which the laser element is disposed and the member on which the mirror is disposed are integrated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the displacement sensor in the above patent documents, when the member (substrate) on which the laser element is disposed and the member on which the mirror is disposed are integrated, it is difficult to adjust the relative distance between the laser element and the mirror after mounting the laser element. Therefore, since the mounting of the laser element cannot be redone, caution is required.

[0005] An object of the present disclosure is to provide a displacement sensor and a method for manufacturing the displacement sensor, in which the position adjustment of the distance between the laser element and the mirror is easy even after mounting the laser element.

Means for Solving the Problems

[0006] An embodiment of the present disclosure is a displacement sensor comprising: a first member; a second member provided on the first member and having an opening; a laser element provided on the upper surface of the first member within the opening and emitting laser light; a mirror provided on the side surface of the opening and reflecting the laser light; and a first photodetector that receives reflected light reflected by an object from the laser light reflected by the mirror, wherein the first member and the second member are separate members.

[0007] Embodiments of the present disclosure are methods for manufacturing a displacement sensor, comprising the steps of: preparing a first member having a laser element on its upper surface and a second member having an opening and a mirror on the side surface of the opening; arranging the second member on the first member such that the laser element is located within the opening; adjusting the position of the second member on the first member by emitting laser light from the laser element and detecting the laser light reflected by the mirror above the second member; and fixing the second member on the first member at the adjusted position of the second member. [Effects of the Invention]

[0008] According to this disclosure, the distance between the laser element and the mirror can be easily adjusted even after the laser element has been mounted. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a cross-sectional view of the displacement sensor according to the first embodiment. [Figure 2] Figure 2 is a cross-sectional view of the displacement sensor according to the first embodiment. [Figure 3] Figure 3 is a plan view of the first and second members of the displacement sensor according to the first embodiment. [Figure 4] Figure 4 is a plan view of the first member of the displacement sensor according to the first embodiment. [Figure 5] Figure 5 is a flowchart showing a method for manufacturing a displacement sensor according to the first embodiment. [Figure 6]Figure 6 is a cross-sectional view showing a method for manufacturing a displacement sensor according to the first embodiment. [Figure 7] Figure 7 is a cross-sectional view showing a method for manufacturing a displacement sensor according to the first embodiment. [Figure 8] Figure 8 is a cross-sectional view showing a method for manufacturing a displacement sensor according to the first embodiment. [Figure 9] Figure 9 is a plan view of the displacement sensor according to the second embodiment. [Figure 10] Figure 10 is a plan view of the displacement sensor according to the third embodiment. [Modes for carrying out the invention]

[0010] The embodiments for implementing this disclosure will be described in detail below with reference to the drawings. The embodiments described below are examples for realizing the technical concept of the invention and do not limit this disclosure to the configurations and numerical values ​​described. In each drawing, the same reference numerals are used for the same components, and redundant explanations may be omitted as appropriate.

[0011] (First Embodiment) Figures 1 and 2 are cross-sectional views of a displacement sensor according to the first embodiment. Figure 3 is a plan view of the first and second members of the displacement sensor according to the first embodiment. Figure 4 is a plan view of the first member of the displacement sensor according to the first embodiment. The stacking direction of the first member 10 and the second member 20 is the Z direction, the direction in which the laser beam 50A is emitted from the laser element 14 is the X direction, and the direction intersecting the X and Z directions is the Y direction. Figure 1 is a cross-sectional view of AA in Figures 3 and 4. Figure 2 is a cross-sectional view of BB in Figures 3 and 4.

[0012] As shown in Figures 1 to 4, the displacement sensor 100 according to the first embodiment comprises a first member 10, a second member 20, a third member 30, a laser element 14, mirrors 22A to 22D, and a photodetector 34. The second member 20 is provided on the first member 10. The third member 30 is provided on the second member 20.

[0013] The wirings 12A to 12D and the alignment marks 13 are provided on the upper surface of the first member 10. The laser element 14 is mounted on the end of the wiring 12A. The bonding wire 16A electrically connects the upper surface of the laser element 14 and the end of the wiring 12B. The thermistor 15 is mounted on the end of the wiring 12C. The bonding wire 16B electrically connects the upper surface of the thermistor 15 and the end of the wiring 12D. The alignment mark 13 is a mark indicating the approximate position where the second member 20 is to be mounted. The upper surface of the first member 10 is substantially a flat surface. Here, the flat surface does not mean a strictly flat surface, and allows unevenness of the order of manufacturing errors.

[0014] The second member 20 is a frame body having an opening 21 penetrating in the Z direction. The planar shape of the opening 21 is rectangular. The opening 21 has side surfaces 21A to 21D. The side surfaces 21A to 21D are inclined such that the upper surface of the opening 21 is larger than the lower surface. The mirrors 22A to 22D are provided on the side surfaces 21A to 21D. The angle (tilt angle θ) formed by the lower surface of the second member 20 and the side surfaces 21A to 21B is, for example, smaller than 90° and larger than 45°.

[0015] The laser element 14 and the thermistor 15 are provided on the upper surface of the first member 10 within the opening 21. The wirings 12A to 12D pass between the first member 10 and the second member 20 and extend outside the second member 20 from within the opening 21. Thereby, a voltage or current can be supplied to the laser element 14 from outside the second member 20 via the wirings 12A and 12B. A signal can be output from the thermistor 15 outside the second member 20 via the wirings 12C and 12D. Based on the temperature information detected by the thermistor 15, the laser element 14 is controlled. The thermistor 15 is an example of a component provided within the opening 21, and components such as a control circuit for controlling, for example, the laser element 14 other than the thermistor 15 and a drive circuit for driving the laser element 14 may be provided within the opening 21.

[0016] The third member 30 has lenses 32A and 32B on its lower surface (-Z plane). The photodetector 34 is provided on the upper surface of the third member 30.

[0017] In FIG. 1, the intensity distributions of the laser beams 50A and 50B are, for example, Gaussian distributions. In the laser beams 50A to 53A and 50B to 53B, the center line is the line where the intensity is maximum and corresponds to the optical axis. The two outer lines are the lines where the intensity of the laser beam is half of the maximum intensity. The distance between the two outer lines is the full width at half maximum.

[0018] As shown in FIG. 1, the laser element 14 emits the laser beams 50A and 50B in the +X direction and the -X direction, respectively. The laser beams 50A and 50B are divergent light. The mirrors 22A and 22B are provided so as to reflect the light within at least the full width at half maximum of the laser beams 50A and 50B. The optical axes of the laser beams 51A and 51B reflected by the mirrors 22A and 22B approach each other as they go in the +Z direction. The mirrors 22A and 22B are plane mirrors. The laser beams 51A and 51B are divergent light.

[0019] The lenses 32A and 32B are convex lenses and transmit the laser beams 51A and 51B as collimated laser beams 52A and 52B. The lenses 32A and 32B are provided so as to transmit the light within at least the full width at half maximum of the laser beams 51A and 51B. The laser beams 52A and 52B are refracted on the upper surface of the third member 30 and emitted as the laser beams 53A and 53B. The laser beams 53A and 53B are collimated light and approach each other as they go in the +Z direction. Here, the collimated light does not have to be strictly collimated light, and it may be collimated light that functions as a displacement sensor. The object 36 is located in the +Z direction of the displacement sensor 100. The laser beams 53A and 53B are reflected by the object 36. The photodetector 34 receives the reflected light 54A and 54B that the laser beams 53A and 53B are reflected by the object 36. The photodetector 34 may be two photodetectors, one for receiving the reflected light 54A and the other for receiving the reflected light 54B. When the object 36 is a diffraction grating, the displacement sensor 100 functions as an encoder. When the object 36 is an object other than a diffraction grating, the displacement sensor 100 functions as a Doppler sensor.

[0020] The first member 10 is, for example, an insulating substrate such as aluminum nitride, aluminum oxide, or diamond, or a semiconductor substrate such as a silicon substrate. The wiring 12A to 12D is, for example, a metal film such as a copper film, gold film, or aluminum film. The second member 20 is, for example, a semiconductor substrate such as a silicon substrate, an insulating substrate, or a metal substrate. The mirrors 22A to 22D are, for example, metal films such as aluminum film, gold film, and silver film that have high reflectivity at the wavelength of laser light, and are formed on the sides 21A and 21B using, for example, a sputtering method. The third member 30 is a member that is transparent to laser light, for example, an inorganic insulator such as glass, or a transparent resin. The laser element 14 is, for example, a semiconductor laser element, for example, a DFB (Distributed-Feedback Laser) laser. By appropriately setting the reflectivity of the end faces of the laser element 14, laser light 50A and 50B can be emitted from both end faces of the laser element 14. The photodetector 34 is, for example, a photodiode.

[0021] Sides 21C and 21D do not need to be inclined, but they may be inclined when sides 21A and 21B are inclined. Also, mirrors 22C and 22D do not need to be provided, but they may be formed when mirrors 22A and 22B are formed. When a single-crystal silicon substrate with a (100) plane as the main surface is used as the second member 20, if the opening 21 is formed using an etching method with an aqueous potassium hydroxide solution, then sides 21A and 21B become (111) planes. In this case, the inclination angle θ is 54.7°. When the opening 21 is formed in this way, the inclination angles of sides 21C and 21D also become 54.7°. Furthermore, the planar shape of the opening 21 is rectangular.

[0022] Figure 5 is a flowchart illustrating a method for manufacturing a displacement sensor according to the first embodiment. As shown in Figure 5, a first member 10, a second member 20, and a third member 30 are prepared (step S10). Wirings 12A to 12D are formed on the upper surface of the first member 10. An opening 21 is formed in the second member 20, and mirrors 22A to 22D are formed on the side surfaces 21A to 21D. Lenses 32A and 32B are formed on the lower surface of the third member 30. Next, a laser element 14 is mounted on the upper surface of the first member 10 (step S11). As shown in Figure 3, the upper surface of the laser element 14 and the wiring 12B are electrically connected using a bonding wire 16A. A base may be mounted on the first member 10, and the laser element 14 may be mounted on the base.

[0023] Next, the second member 20 is placed on the first member 10 and its position is adjusted (step S12). Figure 6 is a cross-sectional view showing a method for manufacturing a displacement sensor according to the first embodiment. As shown in Figure 6, the laser element 14 is positioned in the opening 21, and the second member 20 is placed on the first member 10 so that the four corners of the second member 20 align with the alignment marks 13 in Figure 4. A camera 38 capable of capturing two dimensions is placed above the laser element 14. The camera 38 captures light of the wavelengths of the laser beams 50A and 50B. If the laser beams 50A and 50B are infrared light, the camera 38 is an infrared camera. The distance between the camera 38 and the first member 10 is set to a predetermined distance. In this state, the laser element 14 emits laser beams 50A and 50B in the ±X directions. The laser beams 50A and 50B are reflected by the mirrors 22A and 22B. The reflected laser beams 51A and 51B reach the imaging surface of the camera 38.

[0024] Using the jig 28, the position of the second member 20 in the X direction is adjusted so that the laser beams 50A and 50B are in predetermined positions in the image captured by the camera 38. For example, the position of the second member 20 in the X direction is adjusted so that the distance D2A between the position where the laser beam 51A is irradiated onto the camera 38 and the center line 39 is equal to the distance D2B between the position where the laser beam 51B is irradiated onto the camera 38 and the center line 39. As a result, the distance D1A between the laser element 14 and the mirror 22A is equal to the distance D1B between the laser element 14 and the mirror 22B.

[0025] Returning to Figure 5, the second member 20 is fixed to the first member 10 at the position adjusted in step S12 (step S13). For fixing the second member 20, an adhesive is used, for example. Next, the third member 30 is fixed onto the second member 20 (step S14). The photodetector 34 is mounted on the third member 30. The photodetector 34 may be mounted on the third member 30 in advance. Thus, the displacement sensor 100 according to the first embodiment is manufactured.

[0026] In the displacement sensor 100, it is important to adjust the distance over which the laser beams 50A, 51A, 52A, and 53A propagate from the laser element 14 to the object 36. In particular, when interfering the laser beams 53A and 53B, it is important to adjust the distance over which the laser beams 50A, 51A, 52A, and 53A propagate, and the distance over which the laser beams 50B, 51B, 52B, and 53B propagate. For example, to make the distance over which the laser beams 50A, 51A, 52A, and 53A propagate equal to the distance over which the laser beams 50B, 51B, 52B, and 53B propagate, distances D1A and D1B are made equal.

[0027] When the first member 10 and the second member 20 are provided as a single unit, the mounting position of the laser element 14 is moved in the X direction to adjust the distances D1A and D1B. However, in order to adjust the position of the laser element 14 while it is emitting laser beams 50A and 50B, the position of the laser element 14 must be adjusted while supplying voltage or current to the laser element 14. In addition, a jig must be placed inside the aperture 21 to adjust the position of the laser element 14. For this reason, adjusting the distances D1A and D1B is difficult. In the first embodiment, as shown in Figure 6, the distances D1A and D1B can be easily adjusted.

[0028] Figure 7 is a plan view of the displacement sensor according to the first embodiment. As shown in Figure 7, the distances D1A and D1B can be adjusted in step S12 of Figure 5. For example, to make the distance D1B longer than the distance D1A, the second member 20 can be moved in the -Y direction as shown by arrow 41, thereby making the distance D1B longer than the distance D1A.

[0029] Figure 8 is a plan view of the displacement sensor according to the first embodiment. As shown in Figure 8, in step S12 of Figure 5, if there is an abnormality at locations 43A and 43B where the laser beams 50A and 50B are irradiated onto the mirrors 22A and 22B, the second member 20 is moved in the +X direction as indicated by arrow 42. This makes it possible to shift the locations where the laser beams 50A and 50B are irradiated onto the mirrors 22A and 22B.

[0030] As described above, according to the first embodiment, the first member 10 and the second member 20 are separate members. As shown in step S10 of Figure 5, a first member 10 with a laser element 14 on its upper surface and a second member 20 with mirrors 22A and 22B on the sides 21A and 21B of the opening 21 are prepared. As shown in step S11, the second member 20 is placed on the first member 10 so that the laser element 14 is located inside the opening 21. As shown in step S12 and Figure 6, laser beams 50A and 50B are emitted from the laser element 14, and the position of the second member 20 on the first member 10 is adjusted by detecting the laser beams 51A and 51B reflected by the mirrors 22A and 22B above the second member 20. As shown in step S13, the second member 20 is fixed onto the first member 10 at the adjusted position of the second member 20. As a result, as shown in Figure 6, the position of the second member 20 in the X direction can be easily adjusted by pressing the outer surface of the second member 20 using the jig 28. Furthermore, it is not necessary to adjust the position of the laser element 14 on the upper surface of the first member 10. Therefore, it is easy to emit laser beams 50A and 50B from the laser element 14.

[0031] The laser element 14 emits a pair of laser beams 50A and 50B in opposite directions. Mirrors 22A and 22B are provided in pairs corresponding to the pair of laser beams 50A and 50B. The photodetector 34 (first photodetector) receives a pair of reflected light beams 54A and 54B that are reflected by the object 36 from the pair of laser beams 53A and 53B reflected by the mirrors 22A and 22B. In such a displacement sensor 100, adjusting the phase of the laser beams 53A and 53B is important in order to cause interference between the reflected light beams 54A and 54B. Therefore, by treating the first member 10 and the second member 20 as separate members and adjusting the position of the second member 20 on the first member 10, the distances D1A and D1B can be adjusted with high precision.

[0032] The intensity ratio of laser beams 50A and 50B may be 1:1 or different. The intensity ratio of laser beams 50A and 50B should be within the range in which reflected light 54A and 54B can interfere. The laser element 14 may emit laser beam 50A but not laser beam 50B, and the mirror 22B and lens 32B may not be provided. For example, a configuration like that in Patent Document 1 may be used.

[0033] In order to cause the reflected light beams 54A and 54B to interfere, it is preferable to make the distance D1A between the laser element 14 and one mirror 22A equal to the distance D1B between the laser element 14 and the other mirror 22B. Equal distances D1A and D1B do not mean strictly equal. It is sufficient that the distances D1A and D1B are equal to the extent that the reflected light beams 54A and 54B interfere, and the difference between distances D1A and D1B is preferably less than or equal to, for example, the wavelength of the laser light beams 50A and 50B in air.

[0034] When the first member 10 and the second member 20 are a single unit, the wiring 12A to 12D would be provided on the side and top surfaces of the second member 20. In this case, forming the wiring 12A to 12D becomes difficult, such as forming the wiring 12A to 12D in areas other than the mirrors 22A and 22B, or forming the wiring 12A to 12D continuously on the top and side surfaces. In the first embodiment, the first member 10 and the second member 20 are separate members. The wiring 12A to 12D is provided on the top surface of the first member 10, connecting the inside of the opening 21 and the outside of the second member 20, and passing between the first member 10 and the second member 20. This makes it easy to form the wiring 12A to 12D.

[0035] Wires 12A and 12B are electrically connected to the laser element 14. This allows voltage or current to be supplied to the laser element 14 via wires 12A and 12B.

[0036] In order to precisely control the inclination angle θ of the sides 21A and 21B, the material of the second member 20 may be selected. For example, by making the second member 20 a silicon substrate with (100) as its main surface, the inclination angle of the sides 21A and 21B can be precisely set to 54.7°. When the first member 10 and the second member 20 are a single silicon substrate, an insulating film is formed between the silicon substrate and the wirings 12A to 12D in order to electrically insulate the wirings 12A to 12D. However, the insulating film has a lower thermal conductivity than the silicon substrate, which can affect the heat dissipation of the laser element 14. Therefore, by using a material for the first member 10 that has high insulating properties and high thermal conductivity, the wirings 12A to 12D can be electrically insulated without forming an insulating film. This improves the heat dissipation from the laser element 14.

[0037] When a material with low thermal conductivity is used as the second member 20, the first member 10 having a higher thermal conductivity than the second member 20 is used. This allows the heat generated in the laser element 14 to be efficiently dissipated. The thermal conductivity of the first member 10 is preferably 1.1 times or more than the thermal conductivity of the second member 20, and more preferably 1.2 times or more.

[0038] Lenses 32A and 32B are mounted on the second member 20, and laser light 52A and 52B reflected by mirrors 22A and 22B are incident on them. Laser light 53A and 53B that have passed through lenses 32A and 32B are irradiated onto the object 36. This allows collimated light to be irradiated onto the object 36.

[0039] (Second Embodiment) Figure 9 is a plan view of the displacement sensor according to the second embodiment. In Figure 9, the third member 30 is not shown. As shown in Figure 9, in the displacement sensor 102 according to the second embodiment, the planar shape of the second member 20 is a rectangle with one side missing. The opening 21 is open in the +Y direction. That is, the second member 20 has portions 23A, 23B and 23D. Portions 23A and 23B are portions having sides 21A and 21B, respectively. Portion 23D is the portion connecting the pair of sides 21A and 21B of the opening 21. The second member 20 is not provided in the region 44 facing portion 23D relative to the opening 21. The other configurations are the same as in the first embodiment and are not described.

[0040] According to the second embodiment, the second member 20 can be positioned at a desired location on the first member 10 by sliding the second member 20 in the +Y direction, as shown by arrow 40. Therefore, when positioning the second member 20 on the first member 10, contact between the second member 20 and the laser element 14, thermistor 15, bonding wire 16A, or 16B can be reduced.

[0041] (Third embodiment) Figure 10 is a plan view of the displacement sensor according to the third embodiment. In Figure 10, the third member 30 is not shown. As shown in Figure 10, in the displacement sensor 104 according to the third embodiment, the second member 20 has portions 23A to 23C. Portion 23C is the portion that connects a pair of sides 21A and 21B of the opening 21. The second member 20 is not provided in the region 44 facing portion 23C with respect to the opening 21. As a result, the second member 20 can be positioned at a desired location on the first member 10 by sliding the second member 20 in the -Y direction, as shown by the arrow 40.

[0042] On the upper surface of the first member 10, in addition to wirings 12A to 12D, wirings 12E and 12F are provided. The photodetector 17 (second photodetector) is mounted on the end of wiring 12E on the upper surface of the first member 10 in region 44. The bonding wire 16C electrically connects the upper surface of the photodetector 17 to the end of wiring 12F. Wirings 12E and 12F extend through a part of region 44. This allows the photodetector 17 to output a signal via wirings 12E and 12F. Light scattered by the member from laser beams 50A and 50B is incident on the light-receiving surface of the photodetector 17. The control circuit controls the output of the laser element 14 based on the output of the photodetector 17. The other configurations are the same as in the second embodiment and are omitted from the description.

[0043] According to the third embodiment, the second member 20 can be positioned at a desired location on the first member 10 by sliding the second member 20 in the -Y direction, as shown by arrow 40. Furthermore, components such as a photodetector 17 may be mounted in region 44. Components mounted in region 44 may include a thermistor, a drive circuit, or a control circuit, in addition to the photodetector 17. By mounting components on the upper surface of the first member 10 in region 44 in this way, the displacement sensor 104 can be miniaturized.

[0044] To monitor the laser beam from the laser element 14, it is common to monitor the laser beam emitted from the side opposite to the laser beam emission surface. However, when laser beams 50A and 50B are emitted from both end faces of the laser element 14, it is not possible to monitor one of the laser beams. According to the third embodiment, a photodetector 17 is provided in region 44 to detect a portion of the laser beam. This makes it possible to provide a photodetector 17 for monitoring and controlling the laser element 14. The photodetector 17 may also be provided in region 44 of the displacement sensor 102 of the second embodiment.

[0045] As described above, embodiments have been explained, but these embodiments are presented as examples only, and the present invention is not limited by these embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, and modifications are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

[0046] The embodiments of the present invention are, for example, as follows. <1> A displacement sensor comprising: a first member; a second member provided on the first member and having an opening; a laser element provided on the upper surface of the first member within the opening and emitting laser light; a mirror provided on the side surface of the opening and reflecting the laser light; and a first photodetector that receives reflected light from an object after the laser light reflected by the mirror has been reflected. The first member and the second member are separate components. <2> The laser element emits a pair of laser beams in opposite directions, the mirrors are provided in pairs corresponding to the pair of laser beams, and the first photodetector receives a pair of reflected light beams that are reflected by the object from the pair of laser beams reflected by the pair of mirrors. <2> Displacement sensor as described above. <3> The second member has a portion that connects a pair of sides of the opening in which the pair of mirrors are provided, and the second member is not provided in the region opposite to the portion with respect to the opening. <2> Displacement sensor as described above. <3> The above region includes a component provided on the upper surface of the first member, <3> Displacement sensor as described above. <5> The aforementioned component is a second photodetector, <4> Displacement sensor as described above. <6> The distance between the laser element and one of the pair of mirrors is equal to the distance between the laser element and the other of the pair of mirrors. <2> from <5> A displacement sensor as described in any one of the items. <7> The first member is provided on the upper surface of the first member, and has wiring that connects the inside of the opening to the outside of the second member and passes between the first member and the second member. <1> from <6> A displacement sensor as described in any one of the items. <8> The wiring is electrically connected to the laser element. <7> Displacement sensor as described above. <9> The thermal conductivity of the first member is higher than the thermal conductivity of the second member. <1> from <8> A displacement sensor as described in any one of the items. <10> The second member is provided with a lens into which the laser light reflected by the mirror is incident, and the laser light that has passed through the lens is irradiated onto the object, <1> from <9> A displacement sensor as described in any one of the items. <11> A method for manufacturing a displacement sensor, comprising the steps of: preparing a first member having a laser element on its upper surface and a second member having an opening and a mirror on the side of the opening; arranging the second member on the first member such that the laser element is located within the opening; adjusting the position of the second member on the first member by emitting laser light from the laser element and detecting the laser light reflected by the mirror above the second member; and fixing the second member on the first member at the adjusted position of the second member. [Explanation of Symbols]

[0047] 10 First Member 12A, 12B, 12C, 12D, 12E, 12F wiring 14 Laser elements 15 Thermistor 16A, 16B, 16C bonding wires 17, 34 Photodetectors 20 Second Member 21 Aperture 21A, 21B, 21C, 21D side 22A, 22B, 22C, 22D Miller 23A, 23B, 23C, 23D parts 28 Jig 30 Third Member 32A, 32B lenses 36. Object 38 Cameras 44 areas 50A, 50B, 51A, 51B, 51A, 52B, 53A, 53B, Laser light 54A, 54B reflected light

Claims

1. First member and A second member provided on the first member and having an opening, A laser element that emits laser light is provided on the upper surface of the first member within the opening, A mirror provided on the side of the opening, which reflects the laser light, A first photodetector receives the reflected light from the object, which is the laser light reflected by the mirror. Equipped with, A displacement sensor in which the first member and the second member are separate members.

2. The aforementioned laser element emits a pair of laser beams in opposite directions. The mirrors are provided in pairs, corresponding to the pair of laser beams. The displacement sensor according to claim 1, wherein the first photodetector receives a pair of reflected light from the object, which is a pair of laser beams reflected by the pair of mirrors.

3. The second member has a portion that connects the pair of sides of the opening in which the pair of mirrors are provided, The displacement sensor according to claim 2, wherein the second member is not provided in the region opposite to the portion with respect to the opening.

4. The displacement sensor according to claim 3, comprising a component provided on the upper surface of the first member in the region.

5. The displacement sensor according to claim 4, wherein the component is a second photodetector.

6. The displacement sensor according to any one of claims 2 to 5, wherein the distance between the laser element and one of the pair of mirrors is equal to the distance between the laser element and the other of the pair of mirrors.

7. A displacement sensor according to any one of claims 1 to 5, comprising a wiring provided on the upper surface of the first member, connecting the inside of the opening to the outside of the second member, and passing between the first member and the second member.

8. The displacement sensor according to claim 7, wherein the wiring is electrically connected to the laser element.

9. The displacement sensor according to any one of claims 1 to 5, wherein the thermal conductivity of the first member is higher than that of the second member.

10. The second member is provided with a lens into which the laser light reflected by the mirror is incident, The displacement sensor according to any one of claims 1 to 5, wherein a laser beam that has passed through the lens is irradiated onto the object.

11. The process involves preparing a first member having a laser element on its upper surface, and a second member having an opening with a mirror on the side surface of the opening, The steps include: arranging the second member on the first member such that the laser element is located within the aperture; A step of adjusting the position of the second member on the first member by emitting laser light from the laser element and detecting the laser light reflected by the mirror above the second member, The steps include fixing the second member onto the first member at the adjusted position of the second member, A method for manufacturing a displacement sensor, including the method described above.

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