JP2009139175A - Parallel mirror device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a parallel mirror which is made up by arranging a pair of mirror chips opposite to each other, to be simply measured in parallelism and displacement for a short time. <P>SOLUTION: A reflector 2D is disposed on a diagonal position of each of mirror chips 2, in order to reflect inspection light for inspecting the parallelism and displacement between the pair of mirror chips 2. Accordingly, the inspection light with which one reflector 2D of the pair of reflectors 2D is irradiated, is reflected toward the other reflector 2D, and the intensity of light reflected by the other reflector 2D and its intensity distribution are detected, thereby the parallelism and displacement between the mirror chips 2 can be determined in a single measurement procedure. Accordingly, the parallelism and displacement between the mirror chips 2 opposite to each other can be measured simply for the short time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a parallel mirror device that multi-reflects light between two opposing mirror chips, and a manufacturing method thereof.

  A gas sensor that measures the concentration of gas utilizes absorption of light of a specific wavelength depending on the type of gas. However, in order to detect a low-concentration gas, it is necessary to increase the length of light passing through the gas (optical path length), which leads to an increase in the size of the gas sensor.

  On the other hand, the inventors made a pair of mirror chips having a concave mirror part with high reflectivity face each other, and made light incident between the pair of mirror chips from the outside of one mirror chip, and the incident light was After making multiple reflections between the mirror parts, a gas sensor with an optical path length longer than the actual distance between the mirror chips by emitting light from the other mirror chip was experimentally studied.

  However, in the gas sensor according to the above-described trial production, the light introduced between the mirror chips is reflected a plurality of times at each mirror part, so the parallelism and the positional deviation between the pair of mirror chips greatly affect the characteristics of the gas sensor. There is a problem. Therefore, in the gas sensor according to the trial manufacture, it is necessary to manage the parallelism and the positional deviation between the pair of facing mirror chips with high accuracy.

For example, in the invention described in Patent Document 1, in order to mount a pair of chips in parallel with high accuracy, the distance between the chips is measured by measuring the distance between the chips at at least three points. While measuring, the parallelism between a pair of chips is readjusted based on the measurement result.
JP-A-5-326633

  However, in the invention described in Patent Document 1, since it is necessary to measure at least three distances between the chips, the measurement is complicated and at least three points each time the parallelism is readjusted. It is necessary to remeasure the distance between the chips, and it is difficult to reduce the number of manufacturing steps.

  In view of the above points, the present invention provides a parallel mirror device in which a pair of mirror chips are arranged so as to face each other as in the gas sensor according to the above-described trial study, and the parallelism and the positional deviation can be measured in a short time. It is an object of the present invention to provide a mirror device and a method of manufacturing the parallel mirror device.

  In order to achieve the above object, the present invention has a mirror part (2C) for reflecting light in the invention according to claim 1, and the mirror part (2C) is disposed so as to be opposed to each other. A pair of mirror chips (2), a holding member (3) for holding the pair of mirror chips (2), and a parallelism between the pair of mirror chips (2) provided on each of the pair of mirror chips (2). And a reflecting portion (2D) that reflects light for detecting misalignment, and each of the pair of reflecting portions (2D) is a mirror on the same side as the surface on which the mirror portion (2C) is formed. A pair of reflections on a virtual surface (S) that is provided in an area other than the portion (2C) and is orthogonal to the direction (L) from the one mirror chip (2) side toward the other mirror chip (2) side. When the part (2D) is projected, one reflection part (2D) Characterized in that it misaligned relative elevation portion (2D).

  Thereby, in invention of Claim 1, while reflecting the light irradiated to any one reflection part (2D) among a pair of reflection parts (2D) toward the other reflection part (2D), By detecting the light amount and the light amount distribution of the light reflected by the other reflecting portion (2D), the parallelism and the positional deviation between the mirror chips (2) can be determined by a single measurement.

Therefore, it becomes possible to measure the parallelism and displacement between the facing mirror chips (2) simply and in a short time.
In addition, when the reflection part (2D) is not provided in the mirror chip (2), the parallelism and the positional deviation between the mirror chips (2) cannot be measured by using the method described above. It is impossible to measure the parallelism and displacement between the facing mirror chips (2) simply and in a short time.

  In a second aspect of the present invention, when the pair of reflecting portions (2D) and the pair of mirror chips (2) are projected onto the virtual plane (S), the pair of reflecting portions (2D) is any mirror chip. (2) It is located in the position which becomes symmetrical with respect to the center.

  Accordingly, in the invention described in claim 2, the distance between the pair of reflection portions (2D) becomes long, and the light reflected by one reflection portion (2D) and incident on the other reflection portion (2D) Since the angle formed with the other reflecting portion (2D) is reduced, the amount of light to be detected and the change in the light amount distribution are increased, and it becomes possible to accurately detect parallelism and positional deviation.

The “center of the mirror chip (2)” means the centroid (position where the area moment is balanced) of the mirror chip (2) projected on the virtual plane (S).
In the third aspect of the invention, the outline of the pair of mirror chips (2) is rectangular, and the pair of reflecting portions (2D) and the pair of mirror chips (2) are projected onto the virtual plane (S). Then, one reflection part (2D) is located in the diagonal position of a mirror chip (2) with respect to the other reflection part (2D).

  Thereby, also in the invention of Claim 3, while the distance between a pair of reflection parts (2D) becomes long similarly to the invention of Claim 2, it reflects with one reflection part (2D). Since the angle formed between the light incident on the other reflecting portion (2D) and the other reflecting portion (2D) becomes small, it becomes possible to accurately detect parallelism and positional deviation.

In invention of Claim 4, one reflection part (2D) is larger than the other reflection part (2D) among a pair of reflection parts (2D), It is characterized by the above-mentioned.
Thereby, in invention of Claim 4, light is first irradiated to a smaller reflective part (2D), and the light reflected by this smaller reflective part (2D) is reflected on the larger reflective part (2D). If the parallelism and the positional deviation between the pair of mirror chips (2) are within the target predetermined accuracy range, the light reflected by the smaller reflecting portion (2D) Are incident on the larger reflecting portion (2D).

  On the contrary, when the parallelism and the positional deviation between the pair of mirror chips (2) are outside the target predetermined accuracy range, all of the light reflected by the smaller reflecting portion (2D) is the larger reflected. The incident light does not enter the part (2D), and the amount of light to be detected decreases.

  Therefore, by detecting whether or not all of the light reflected by the smaller reflecting portion (2D) is incident on the larger reflecting portion (2D), the parallelism between the pair of mirror chips (2) and It becomes possible to perform the measurement of positional deviation more easily.

  Incidentally, when light is first irradiated to the larger reflecting portion (2D) and the light reflected by the larger reflecting portion (2D) is incident on the smaller reflecting portion (2D), a pair of mirror chips ( 2) All of the light reflected by the larger reflecting portion (2D) is made incident on the smaller reflecting portion (2D) even if the parallelism and positional deviation between them are within the target predetermined accuracy range. Therefore, it becomes difficult to measure parallelism and displacement between the pair of mirror chips (2).

  In the invention according to claim 5, the pair of reflection portions (2D) includes a high reflection region (2E) for reflecting light and a low reflection region (2F) provided on the outer peripheral side of the high reflection region (2E). It is characterized by having.

  Accordingly, in the invention described in claim 5, if the parallelism and the positional deviation between the pair of mirror chips (2) are outside the target predetermined accuracy range, the irradiated light is highly reflected. Since the light is reflected from the low reflection area (2F) without being reflected from the area (2E), the change in the light quantity and the light quantity distribution of the detected light becomes large, and the parallelism and the positional deviation can be accurately detected. It becomes.

  Note that the low reflection region (2F) and the high reflection region (2E) have different light reflection states because at least one of light reflectance, scattering rate, and diffusivity is different. Say.

  By the way, since the light irradiated to the reflection part (2D) is a beam-shaped light ray which has a circular cross section normally, a light ray reflects in an elliptical area | region in a reflection part (2D). Accordingly, the invention according to claim 6 is characterized in that the high reflection region (2E) and the low reflection region (2F) are elliptical with the same point as the center.

Accordingly, in the invention described in claim 6, it is possible to efficiently acquire the information about the parallelism and the positional deviation between the pair of mirror chips (2), that is, the light amount and the light amount distribution of the detected light.
In the invention according to claim 7, when the beam diameter of the light irradiated to the reflecting portion (2D) is a and the angle between the reflecting portion (2D) and the light is θ, the high reflecting region (2E) The minor axis dimension is a or more, the major axis dimension is a / sin θ or more, and the minor axis dimension and major axis dimension of the low reflection region (2F) are respectively the minor axis dimension and major axis dimension of the high reflection region (2E). It is characterized by being twice or more.

Thus, in the invention described in claim 7, it is possible to perform measurement according to the target accuracy.
The invention according to claim 8 is characterized in that the reflection portion (2D) is formed on the bottom surface of the recess (2G) formed in the mirror chip (2).

  Thereby, in invention of Claim 8, the reflection part (2D) formed in the bottom face of a recessed part (2G) functions as a highly reflective area | region (2E) described in Claim 5, and of a recessed part (2G) Sites other than the bottom surface function as the low reflection region (2F) described in claim 5.

  Therefore, since the same effect as that of the invention described in claim 5 can be obtained without forming two types of reflection regions, the target accuracy can be achieved while reducing the number of manufacturing steps of the reflection portion (2D). It is possible to perform measurement in accordance with.

  The invention according to claim 9 is the method for manufacturing the parallel mirror device according to any one of claims 1 to 8, wherein the pair of mirror chips (2) are arranged substantially in parallel with each other. The first step of holding the chip (2), and the light irradiated to one of the reflecting parts (2D) of the pair of reflecting parts (2D) is reflected by one reflecting part (2D) and the other A second step of irradiating one reflective part (2D) with light toward the reflective part (2D), and the other reflective part in a light receiver (26) in which optical elements for measuring the amount of light are arranged in a matrix. Based on the third step of detecting the light reflected at (2D) and the light quantity and light quantity distribution detected by the light receiver (26), the parallelism and positional deviation between the pair of mirror chips (2) are detected. 4 steps and a pair of mirror chips (2 A fifth step of correcting the parallelism and the positional deviation between the pair of mirror chips (2) so as to be within a predetermined range based on the parallelism and the positional deviation between the pair of mirror chips (2) and the parallelism between the pair of mirror chips (2). And a sixth step of holding and fixing the pair of mirror chips (2) by the holding member (3) when the degree and the positional deviation are within a predetermined range.

  Accordingly, in the invention described in claim 9, the parallelism and the positional deviation between the mirror chips (2) are measured at a time by detecting the light quantity and the light quantity distribution of the light reflected by the other reflecting part (2D). Can be judged. Therefore, it becomes possible to measure the parallelism and displacement between the facing mirror chips (2) simply and in a short time.

  In the invention according to claim 10, in the first step, the holding block (21) that contacts the mirror chip (2) from the opposite side of the mirror portion (2C), and the mirror chip (2) and the holding block (21). And a pair of mirror chips (2) in a state where the pair of mirror chips (2) are arranged substantially in parallel using a chucking device having a vacuum pump (22) for sucking air present in the gap between the pair of mirror chips (2). ).

Thereby, in invention of Claim 10, a mirror chip | tip (2) can be attached or detached easily.
Incidentally, the reference numerals in parentheses for each of the above means are examples showing the correspondence with the specific means described in the embodiments described later, and the present invention is indicated by the reference numerals in the parentheses of the above respective means. It is not limited to specific means.

In this embodiment, the parallel mirror device according to the present invention is applied to a gas sensor, and the embodiment of the present invention will be described below with reference to the drawings.
(First embodiment)
1. DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a structure of a gas sensor 1 according to the present embodiment, and FIG. 2A is a diagram showing an outline of an assembly jig 20 of the gas sensor 1 according to the present embodiment. FIG. 2B is a perspective view of the holding block 21 that holds the mirror chip 2.

  3 (a) is a front view of the mirror chip 2, FIG. 3 (b) is a cross-sectional view taken along the line AA of FIG. 3 (a), and FIG. 4 is a diagram showing the positional relationship of the reflecting portion 2D. FIG. 5A is a front view of the reflecting portion 2D, and FIG. 5B is a side view of the reflecting portion 2D.

  FIG. 6A is a diagram showing the trajectory of the measuring beam when measuring parallelism and displacement, and FIG. 6B shows the light receiver 26 used when measuring parallelism and displacement. FIG. 7 is a conceptual diagram, and FIG. 7 is a process diagram showing an operation procedure when measuring parallelism and misalignment.

  FIG. 8A to FIG. 8C are diagrams showing types of assumed parallelism deviation and positional deviation, and FIG. 8D is a diagram showing the definition of the deviation direction, and FIG. FIG. 9C is a diagram showing an example of detection results corresponding to the types of parallelism deviation and positional deviation.

2. Gas sensor configuration (see Fig. 1)
As shown in FIG. 1, the gas sensor 1 includes a pair of mirror chips 2 having a rectangular outline, a housing 3 that holds the pair of mirror chips 2 facing each other, and a mirror chip 2 ( Hereinafter, the mirror chip 2 is referred to as the first mirror chip 2A. The light emitting unit 4 is disposed on the side, and the mirror chip 2 on the right side of the paper (hereinafter, the mirror chip 2 is referred to as the second mirror chip 2B). The light receiving unit 5 and the like are provided.

  In addition, the first mirror chip 2A and the second mirror chip 2B are opposed to each other with a gap 3A filled with a gas to be measured interposed therebetween, and are opposed to each other. Each is provided with a mirror portion 2C that reflects light (in this embodiment, infrared light) incident from the light emitting portion 4 into the gap 3A.

  Incidentally, the mirror part 2C is constituted by a concave mirror having a focal point in the gap 3A, and this mirror part 2C is formed by a thin film formed by vapor-depositing aluminum on the mirror chip 2. The housing 3 is provided with an inlet 3B that guides the inspection target gas to the gap 3A.

  Further, as shown in FIGS. 3 and 4, each of the mirror chips 2A and 2B has a beam-like light for detecting parallelism and displacement between the pair of mirror chips 2 (hereinafter, this light is inspected). The planar reflection part 2D which reflects light is provided, and these reflection parts 2D are areas other than the mirror part 2C on the same side as the surface on which the mirror part 2C is formed in the mirror chip 2. Is provided.

And as shown in FIG. 4, a pair of reflection part 2D is provided in the mutually diagonal position so that one reflection part 2D may shift | deviate with respect to the other reflection part 2D.
That is, when the pair of reflecting portions 2D and the pair of mirror chips 2 are projected onto the virtual plane S orthogonal to the direction L from the second mirror chip 2B side toward the first mirror chip 2A side, the projected pair of reflections The part 2D1 has a positional relationship that is symmetric with respect to the center O1 of any one of the mirror chips 2 projected onto the virtual plane S.

  The “center O1 of any mirror chip 2 projected on the virtual surface S” is a point on the virtual surface S corresponding to the center O of any mirror chip 2, and “the center of the mirror chip 2”. “O” means the centroid of the mirror chip 2 (position where the area moments are balanced).

  Further, as shown in FIG. 5 (a), the reflection portion 2D is configured by two elliptical reflection areas 2E and 2F centered on the same point, and among these two reflection areas 2E and 2F, The reflection area 2E on the center side (hereinafter, this reflection area is referred to as “high reflection area 2E”) is compared with the reflection area 2F provided on the outer peripheral side (hereinafter, this reflection area is referred to as “low reflection area 2F”). The amount of light reflected in a specific direction is set to be large.

  Here, “light reflected in a specific direction” means light that is reflected according to the law of reflection of Euclidean light when the reflecting portion 2D (the high reflection region 2E and the low reflection region 2F) is a flat mirror without unevenness, that is, The light reflected in the direction of the angle equal to the incident angle.

  In this embodiment, the highly reflective region 2E is formed by vapor-depositing Al or Ge / ZnS, and the low reflective region 2F is formed by applying carbon black to the film formed by vapor-depositing Al or Ge / ZnS. The amount of light that is formed and reflected in a specific direction in the high reflection region 2E is made larger than the amount of light reflected in a specific direction in the low reflection region 2F.

  Further, as shown in FIGS. 5A and 5B, when the beam diameter of the light irradiated to the reflecting portion 2D is a and the angle between the reflecting portion 2D and the inspection light is θ, the height is high. The minor axis dimension W1 of the reflection region 2E is a or more, the major axis dimension H1 is a / sin θ or more, and the minor axis dimension W2 and the major axis dimension H2 of the low reflection region 2F are respectively the minor axis dimension W1 of the high reflection region 2E. And it is set to be twice or more of each of the major axis dimension H1.

  As shown in FIG. 3, the pair of reflecting portions 2D are formed on the mirror chip 2 so that the major axis direction thereof is substantially parallel to the diagonal line of the mirror chip 2, and the inspection light is first transmitted to the first mirror. When irradiating the reflection part 2D of the chip 2A, the reflection part 2D (high reflection area 2E and low reflection area 2F) of the second mirror chip 2B is reflected by the reflection part 2D (high reflection area 2E and low reflection area 2F) of the first mirror chip 2A. The dimension is set larger than the area 2F).

3. Operation of the Gas Sensor The gas sensor 1 according to the present embodiment is configured so that the light irradiated from the light emitting unit 4 into the gap 3A is subjected to multiple reflection between the mirror parts 2C in a state where the gap 3A is filled with the inspection target gas, and then the light receiving unit By detecting light at 5, the concentration of the inspection target gas is measured.

  Note that the light reflectance of the mirror portion 2C is not 100%, but about 1% to 10% of the light is transmitted through the mirror portion 2C (mirror chip 2). Therefore, in the present embodiment, light is incident on the gap 3A from the back side of the first mirror chip 2A, and the light is detected by the light receiving unit 5 provided on the back side of the second mirror chip 2B.

  That is, light incident on the gap 3A from the back side of the mirror part 2C of the first mirror chip 2A is reflected by the mirror part 2C of the second mirror chip 2B, but a part of the light is transmitted through the mirror part 2C and received. The light is received by the unit 5.

  Then, the light reflected by the mirror part 2C of the second mirror chip 2B is reflected by the mirror part 2C of the first mirror chip 2A, and reaches the mirror part 2C of the second mirror chip 2B again, part of which is a mirror. The light passes through the part 2C and is received by the light receiving part 5, and the others are reflected by the mirror part 2C of the second mirror chip 2B and reach the mirror part 2C of the first mirror chip 2A.

Thus, in the present embodiment, the gas sensor 1 is miniaturized by making the optical path length longer than the actual distance between the mirror chips 2 by multiple reflection of light between the mirror portions 2C.
4). 4. Manufacturing (assembling) method of gas sensor 4.1. Outline of Manufacture (Assembly) of Gas Sensor FIG. 2A is a view showing an outline of the jig 20 used when the gas sensor 1 is assembled.

  The holding block 21 is made of metal (made of aluminum in this embodiment) that contacts the mirror chip 2 from the opposite side of the mirror portion 2C and holds the mirror chip 2, and the vacuum pump 22 The mirror chip 2 is brought into close contact with the holding block 21 by sucking air that exists in the gap with the holding block 21.

As shown in FIG. 2B, the holding block 21 is provided with a step portion 21 </ b> A for positioning the mirror chip 2 and a communication port 21 </ b> B communicating with the vacuum pump 22.
Further, in FIG. 2A, the valve 23 is for interrupting the negative pressure generated by the vacuum pump 22, and when the valve 23 is closed, the supply of the negative pressure is stopped and the mirror chip 2 is turned off. On the other hand, when the valve 23 is opened, since the negative pressure is supplied, the mirror chip 2 is held in close contact with the holding block (chucking).

The stage 21 </ b> C is a displacement means for displacing the holding block 21, and the measuring instrument 21 </ b> D measures the amount of displacement of the holding block 21.
The light source 25 irradiates the inspection light toward the reflecting portion 2D. In the present embodiment, a He—Ne laser light source is used as the light source 25.

  The light receiver 26 detects the amount of inspection light reflected by the reflecting portion 2D. The light receiver 26 includes a plurality of optical elements 26A (such as PIN diodes) as shown in FIG. By arranging the parts D1-1 and D5-5 shown in FIG. 6B in a matrix (lattice), the amount of light corresponding to the received position can be detected. It is.

  Then, when the pair of mirror chips 2 are held by the jig 20 substantially parallel to each other at a predetermined interval, the parallelism between the first mirror chip 2A and the second mirror chip 2B according to the process chart shown in FIG. Misalignment is corrected. Incidentally, the process chart shown in FIG. 7 shows the work performed by the worker in the order of the processes.

  That is, when the pair of mirror chips 2 are held by the jig 20 substantially parallel to each other at a predetermined interval, first, as shown in FIG. 2 (a), FIG. 6 (a) or FIG. Then, the inspection light is irradiated toward the reflecting portion 2D of the first mirror chip 2A (S1).

  At this time, the direction of the inspection light emitted from the light source 25 is such that, in the design dimension, all of the inspection light is incident on the high reflection region 2E of the first mirror chip 2A and reflected, and the mirror of the first mirror chip 2A. All of the inspection light reflected by the portion 2C is set so as to be incident and reflected on the high reflection region 2E of the second mirror chip 2B.

  For this reason, when the parallelism and the positional deviation between the first mirror chip 2A and the second mirror chip 2B deviate from the design tolerance range, the light quantity and the light quantity distribution of the light received by the light receiver 26 change greatly accordingly. .

  Therefore, when the inspection light is irradiated from the light source 25 toward the reflecting portion 2D of the first mirror chip 2A, the amount of light received and the shape of light received by the light receiver 26 (the shape of the light amount distribution graph) are changed as shown in FIG. Then, it is determined whether or not it is within the design target range (S5).

  At this time, if it is determined that the amount of light received and the shape of light received by the light receiver 26 are not within the designed target range (S5: NO), the tilt and position of the mirror chip 2 are corrected via the stage 21C. (S7). Details of the determination method performed in S5 will be described later.

  When the tilt and position of the mirror chip 2 are corrected (S7), it is again determined whether or not the amount of light received and the shape of light received by the light receiver 26 are within the designed target range (S5). When it is determined that the amount of light received and the shape of light received at 26 are within the designed target range (S5: YES), after the pair of mirror chips 2 is fixed to the housing 3 (S9), the pair of mirrors The chip 2 is removed from the jig 20 (holding block 21) (S11), and then other components such as the light emitting unit 4 and the light receiving unit 5 are assembled (S13).

4.2. Details of determination of received light amount and received light shape (S5) As shown in FIG. 6A, the direction of the inspection light emitted from the light source 25 is the same as that of the first mirror chip 2A in the design dimension. It is set so that all of the inspection light reflected by the mirror part 2C of the first mirror chip 2A is incident and reflected on the high reflection area 2E of the second mirror chip 2B. Therefore, when the parallelism and the positional deviation between the first mirror chip 2A and the second mirror chip 2B deviate from the design tolerance range, the light quantity and the light quantity distribution of the light received by the light receiver 26 change greatly accordingly. To do.

  Further, as the types of parallelism and positional deviation of the second mirror chip 2B with respect to the first mirror chip 2A, positional deviation on the XY plane and rotational deviation on the XY plane (around the Z axis) shown in FIG. Hereinafter, this type is referred to as an in-plane shift), a shift in the Z-axis direction shown in FIG. 8B (hereinafter, this type is referred to as a shift in distance), and a shift in parallelism shown in FIG. 8C. (Rotational deviation around the X axis or around the Y axis) can be considered.

  Incidentally, as shown in FIG. 8D, the X axis, the Y axis, and the Z axis are axes that are orthogonal to each other in a plane parallel to the first mirror chip 2A, and the Z axis is the X axis. It is an axis orthogonal to the axis and the Y axis.

  If only a deviation in the plane occurs, for example, the amount of light detected by the optical element 26A indicated by Dn-3 (n = 1 to 5) of the light receiver 26 is as shown in FIG. 9A. The amount of light received by the specific optical element 26A (D2-3) changes with respect to the target value (value within the design tolerance range) indicated by the broken line.

  If only a distance shift occurs, for example, the amount of light detected by the optical element 26A indicated by Dn-3 (n = 1 to 5) of the light receiver 26 is a broken line as shown in FIG. 9B. The optical element 26A that receives light changes with respect to the target value indicated by (D2-3 → D5-3).

  Also, if only a deviation in parallelism occurs, for example, the amount of light detected by the optical element 26A indicated by Dn-3 (n = 1 to 5) of the light receiver 26 is as shown in FIG. The amount of light received by the specific optical element 26A (D2-3, D3-3, D4-3) decreases and changes with respect to the target value (value within the design tolerance range) indicated by the broken line. The optical element 26A (D5-3) changes.

  As described above, when the parallelism and positional deviation of the second mirror chip 2B with respect to the first mirror chip 2A occur, the amount of light received by the light receiver 26 and the shape of the light amount distribution graph change with respect to the designed target values. Therefore, based on the amount of light received by the light receiver 26 and the shape of the light amount distribution graph, it can be estimated how the second mirror chip 2B is displaced from the first mirror chip 2A.

5). Features of the Gas Sensor According to the Present Embodiment In the present embodiment, since the reflection portion 2D that reflects the inspection light is provided in the pair of mirror chips 2, either one of the pair of reflection portions 2D (the present embodiment) In the embodiment, the inspection light applied to the reflection part 2D) of the first mirror chip 2A is reflected toward the other reflection part 2D (in this embodiment, the reflection part 2D of the second mirror chip 2B), and the other By detecting the light quantity and the light quantity distribution of the light reflected by the reflecting part 2D, the parallelism and the positional deviation between the mirror chips 2 can be determined by a single measurement.

Therefore, as described above, the parallelism and positional deviation between the facing mirror chips 2 can be measured easily and in a short time.
Moreover, in this embodiment, when a pair of reflection part 2D and a pair of mirror chip 2 are projected on the virtual surface S, a pair of reflection part 2D1 projected on the virtual surface S is with respect to the center O1 of the mirror chip 2. Therefore, the distance between the pair of reflecting portions 2D is increased, and the angle formed between the light reflected by one reflecting portion 2D and incident on the other reflecting portion 2D and the other reflecting portion 2D is Since it becomes small, the change of the light quantity and light quantity distribution of the light to detect becomes large, and it becomes possible to detect a parallelism and position shift accurately.

  Moreover, in this embodiment, since one reflection part 2D is larger than the other reflection part 2D among a pair of reflection parts 2D, the smaller reflection part 2D (in this embodiment, the reflection part of the first mirror chip 2A). 2D) is irradiated with light first, and the light reflected by the smaller reflecting portion 2D is made incident on the larger reflecting portion 2D (the reflecting portion 2D of the second mirror chip 2B in this embodiment). For example, if the parallelism and the positional deviation between the pair of mirror chips 2 are within the target predetermined accuracy range, all of the light reflected by the smaller reflecting portion 2D is transferred to the larger reflecting portion 2D. Incident.

  On the contrary, when the parallelism and the positional deviation between the pair of mirror chips 2 are outside the target predetermined accuracy range, all of the light reflected by the smaller reflecting portion 2D enters the larger reflecting portion 2D. Otherwise, the amount of light to be detected is reduced.

  Therefore, by detecting whether all of the light reflected by the smaller reflecting portion 2D is incident on the larger reflecting portion 2D, the parallelism and the positional deviation between the pair of mirror chips 2 are measured. It becomes possible to carry out more simply.

  Further, in the present embodiment, the pair of reflection portions 2D includes the high reflection region 2E that reflects light and the low reflection region 2F provided on the outer peripheral side of the high reflection region 2E. When the parallelism and positional deviation between the mirror chips 2 are outside the target predetermined accuracy range, the irradiated light is reflected by the low reflection region 2F without being reflected by the high reflection region 2E. .

Therefore, the change in the light quantity and the light quantity distribution of the detected light becomes large, and it becomes possible to detect the parallelism and the positional deviation with high accuracy.
By the way, since the inspection light is a beam-like light beam having a circular cross section, and the inspection light is incident on the reflection portion 2D from an oblique direction, the light beam is an elliptical region in the reflection portion 2D. reflect.

  Therefore, in the present embodiment, the high reflection region 2E and the low reflection region 2F are formed into an ellipse centered on the same point, whereby information on the parallelism and positional deviation between the pair of mirror chips 2, that is, the detected light. The light quantity and the light quantity distribution are configured to be acquired from the efficiency.

6). Correspondence between Invention Specific Items and Embodiment In this embodiment, the housing 3 corresponds to the holding member described in the claims, and the holding block 21 and the vacuum pump 22 are used to check the chat. King device is configured.

(Second Embodiment)
In the first embodiment, the reflection part 2D is configured by the elliptical high reflection area 2E and the low reflection area 2F formed concentrically. However, in the present embodiment, as shown in FIG. 2 is formed on the bottom surface of the recess 2G formed in 2 to reflect the same amount of light as the highly reflective region 2E in a specific direction.

  10A is a front view of the mirror chip 2 according to the present embodiment, FIG. 10B is a cross-sectional view taken along line AA in FIG. 10A, and FIG. It is a figure which shows the outline | summary of the shift | offset | difference in the plane in this embodiment, FIG.11 (b) is a figure which shows the outline | summary of the shift | offset | difference of distance in this embodiment, FIG.11 (c) is a parallel in this embodiment. It is a figure which shows the outline | summary of the shift | offset | difference of a degree, and FIG.11 (d) is a figure which shows the definition of the direction of a shift | offset | difference.

  Thereby, in this embodiment, in the reflection part 2D formed on the bottom surface of the recess 2G, an amount of light equivalent to that of the highly reflective region 2E is reflected in a specific direction, and the inspection light is incident on a part other than the bottom surface of the recess 2G. As shown in FIGS. 11A to 11C, the light scatters without reflecting in a specific direction and functions as a low reflection region 2F.

  Therefore, the same effects as those of the first embodiment can be obtained without forming two types of reflection regions, and therefore, measurement according to the target accuracy can be performed while reducing the number of manufacturing steps of the reflection portion 2D. Is possible.

(Other embodiments)
In the above-described embodiment, the parallel mirror device according to the present invention is applied to the gas sensor, but the application of the present invention is not limited to this.

  In the first embodiment described above, the light reflectance is changed between the high reflection region 2E and the low reflection region 2F. However, the present invention is not limited to this, and the low reflection region 2F and the high reflection region are the same. It is sufficient that the light reflection state is different from that of the region 2E, for example, by at least one of light reflectance, scattering rate, and diffusivity being different.

In the above-described embodiment, the contour of the mirror chip 2 is rectangular. However, the present invention is not limited to this. For example, the contour of the mirror chip 2 may be circular or elliptical.
In the above-described embodiment, the pair of reflecting portions 2D are provided at symmetrical positions with respect to the center of one of the mirror chips 2, but the present invention is not limited to this.

  In the above-described embodiment, since the cross section of the inspection light is circular, the shape of the reflecting portion 2D is an ellipse. However, the present invention is not limited to this, and the shape of the reflecting portion 2D is other than an ellipse. (For example, it may be rectangular).

  Further, the present invention is not limited to the above-described embodiment as long as it matches the gist of the invention described in the claims.

It is a schematic diagram which shows the structure of the gas sensor 1 which concerns on this embodiment. (A) is a figure which shows the outline of the jig | tool 20 for the assembly of the gas sensor 1 which concerns on this embodiment, (b) is a perspective view of the holding block 21 holding the mirror chip 2. FIG. (A) is a front view of the mirror chip 2, (b) is AA sectional drawing of Fig.3 (a). It is the figure which showed the reflection part 2D positional relationship. (A) is a front view of reflection part 2D, (b) is a side view of reflection part 2D. (A) is a figure which shows the locus | trajectory of the beam for measurement at the time of measuring parallelism and position shift, (b) is a conceptual diagram of the light receiver 26 used when measuring parallelism and position shift. . It is process drawing which shows the work procedure at the time of measuring parallelism and position shift. It is a figure which shows the pattern of the shift | offset | difference of parallelism assumed, and position shift, (d) is a figure which shows the definition of the direction of a shift | offset | difference. It is a figure which shows an example of the detection result corresponding to the type | mold of the shift | offset | difference of parallelism, and a position shift. (A) is a front view of the mirror chip 2, (b) is AA sectional drawing of (a). It is a figure which shows the pattern of the shift | offset | difference of parallelism assumed, and position shift, (d) is a figure which shows the definition of the direction of a shift | offset | difference.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gas sensor, 2 ... Mirror chip, 2C ... Mirror part, 2D ... Reflection part,
2E ... High reflection region, 2F ... Low reflection region, 2G ... Recess, 3 ... Housing, 3A ... Air gap,
3B ... Introduction port, 4 ... Light emitting part, 5 ... Light receiving part, 20 ... Jig for assembly,
21 ... Holding block, 21A ... Stepped portion, 21B ... Communication port, 21C ... Stage,
21D ... Measuring instrument, 22 ... Vacuum pump, 23 ... Bulb, 25 ... Light source,
26: Light receiver, 26A: Optical element.

Claims (10)

A pair of mirror chips, each having a mirror part for reflecting light, and spaced apart so as to face the mirror part;
A holding member for holding the pair of mirror chips;
A reflection part provided on each of the pair of mirror chips, and reflecting light for detecting parallelism and displacement between the pair of mirror chips;
Each of the pair of reflection portions is provided in a region other than the mirror portion on the same side as the surface on which the mirror portion is formed,
Furthermore, when the pair of reflecting portions are projected on a virtual plane orthogonal to the direction from the one mirror chip side toward the other mirror chip side, one of the reflecting portions is opposite to the other reflecting portion. A parallel mirror device characterized by being misaligned.   When the pair of reflecting portions and the pair of mirror chips are projected onto the virtual plane, the pair of reflecting portions are located at positions that are symmetric with respect to the center of any one of the mirror chips. The parallel mirror device according to claim 1. The outline of the pair of mirror chips is rectangular,
Furthermore, when the pair of reflecting portions and the pair of mirror chips are projected onto the virtual plane, one of the reflecting portions is positioned at a diagonal position of the mirror chip with respect to the other reflecting portion. The parallel mirror device according to claim 2.   4. The parallel mirror device according to claim 1, wherein one of the pair of reflecting portions is larger than the other reflecting portion. 5.   The pair of reflecting portions includes a high-reflecting region that reflects light and a low-reflecting region that is provided on an outer peripheral side of the high-reflecting region. Parallel mirror device described in 1.   The parallel mirror device according to claim 5, wherein the high reflection region and the low reflection region have an elliptical shape centered on the same point. When the beam diameter of the light applied to the reflecting portion is a and the angle formed by the reflecting portion and the light is θ,
The minor axis dimension of the high reflection region is a or more, and the major axis dimension is a / sin θ or more,
The parallel mirror device according to claim 6, wherein each of the minor axis dimension and the major axis dimension of the low reflection region is at least twice the minor axis dimension and the major axis size of the high reflection region.   5. The parallel mirror device according to claim 1, wherein the reflecting portion is formed on a bottom surface of a recess formed in the mirror chip. 6. A method of manufacturing a parallel mirror device according to any one of claims 1 to 8,
A first step of holding the pair of mirror chips in a state in which the pair of mirror chips is disposed substantially in parallel;
Second light that irradiates light on one of the pair of reflective portions so that the light reflected on one of the reflective portions is reflected by the one reflective portion and travels toward the other reflective portion. Process,
A third step of detecting light reflected by the other reflecting portion with a light receiver in which optical elements for measuring the amount of light are arranged in a matrix;
A fourth step of detecting parallelism and displacement between the pair of mirror chips based on the light quantity and light quantity distribution detected by the light receiver;
A fifth step of correcting the parallelism and displacement between the pair of mirror chips within a predetermined range based on the parallelism and displacement between the pair of mirror chips detected in the fourth step; ,
And a sixth step of holding and fixing the pair of mirror chips by the holding member when the parallelism and positional deviation between the pair of mirror chips are within a predetermined range. Production method. In the first step,
Using a chucking device configured to have a holding block that comes into contact with the mirror chip from the opposite side of the mirror part, and a vacuum pump that sucks air that exists in the gap between the mirror chip and the holding block, The method of manufacturing a parallel mirror device according to claim 9, wherein the pair of mirror chips are held in a state where the pair of mirror chips are arranged substantially in parallel.

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