Optical axis deviation evaluation means, optical axis adjustment means, optical axis deviation evaluation method, and optical axis adjustment method

Abstract

To provide an optical axis misalignment evaluation means and an optical axis adjustment means, or an optical axis misalignment evaluation method and an optical axis adjustment method, that can evaluate and adjust the optical axis misalignment of a field recognition means with high precision. [Solution] The device comprises a first subject having a minute through-hole, a laser irradiation means for irradiating laser light in a direction perpendicular to the second surface through the minute through-hole, a second subject that responds to the wavelength of the laser light and emits a wavelength different from that of the laser light, and a control unit having the function of analyzing the image acquired by the two-field recognition means, wherein the oscillation wavelength of the laser light is outside the sensitivity range of the two-field recognition means, the two-field recognition means recognizes the minute through-hole in the first subject and also recognizes an emission point of a wavelength different from that of the laser light emitted by the second subject, and the calculation unit evaluates the optical axis deviation from the relative position information of the image of the minute through-hole and the emission point.

Description

[Technical Field]

[0001] The present invention relates to a two-view recognition means used for alignment when mounting chip components on a substrate. [Background technology]

[0002] When mounting chip components such as semiconductor chips on a substrate, alignment is performed using alignment marks provided on the chip component and the substrate. The alignment marks on both the chip component and the substrate are provided on the electrode side at fixed positions relative to the electrode arrangement. Therefore, by acquiring positional information on the alignment marks on the chip component and the substrate, the relative positional relationship between the chip component and the substrate can be grasped and position adjustment can be performed.

[0003] It is well known that there are two methods for mounting chip components on a substrate: face-up mounting, in which the electrode surface of the chip component faces the electrode surface of the substrate, and face-down mounting, in which the electrode surface of the chip component faces the electrode surface of the substrate. In face-up mounting, both electrode surfaces face the same direction, so the alignment marks of the chip component and the substrate can be captured within a single field of view. In contrast, face-down mounting typically uses a two-view recognition device 100, as shown in Figure 10, which captures the alignment mark AC of the chip component C in one field of view and the alignment mark AS of the substrate S in the other field of view.

[0004] Here, the dual-field recognition means 100 shown in Fig. 10 has the function of acquiring images of two opposing fields of view, one above the other, and is often equipped with a separate imaging means for each field of view. However, with the increasing demand for shorter mounting takt time, the dual-field recognition means 100 needs to operate at high speed between the position shown in Fig. 10 and the retracted position, and it is also necessary to quickly settle any vibrations that occur immediately after moving to the position shown in Fig. 10. For this reason, there is a strong demand for dual-field recognition means to be smaller and lighter, and from this perspective, there is a great deal of interest in dual-field recognition means that acquire images of two fields of view using a single imaging means (e.g., Patent Document 1).

[0005] Figure 11 shows an example of a two-field recognition means 100 in which one imaging means acquires images of two fields of view. Here, Figure 11(a) shows the basic configuration of the two-field recognition means 100, in which the optical element 3 superimposes the images of the two fields of view and is captured by the imaging means 2. The optical element 3 is composed of a half mirror 31 and a mirror 32, and since there is only one imaging means, as shown in the top view in Figure 11(b), it is possible to make it smaller and lighter compared to one that has two imaging means. In Figure 11, the images of two fields of view are superimposed by the optical element 3 consisting of a half mirror 31 and a mirror 32, but it is also possible to superimpose the two-field images using an optical element 300 consisting of a dichroic prism, such as the two-field recognition means 101 shown in Figure 12. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. WO2024 / 014077 Summary of the Invention [Problem to be solved by the invention]

[0007] Fig. 13 shows a state in which a chip component C and a substrate S, which are arranged parallel and facing each other, are aligned. In the example of Fig. 13, a chip recognition mark AC of the chip component C is located on a perpendicular line (with respect to the substrate S) to a substrate recognition mark AS of the substrate S.

[0008] In Figure 13, both the first optical path OP1, which guides the image of the upper field of view, and the second optical path OP2, which guides the image of the lower field of view, are perpendicular to the surface of the substrate S (and the surface of the chip component C). In this state, the image of the upper field of view guided by the first optical path OP1 and the image of the lower field of view guided by the second optical path OP2 are superimposed by the optical element 3 and guided by the third optical path, and the image acquired by the imaging means 2 is as shown in Figure 15(a). In other words, the aligned state can be confirmed by the captured image.

[0009] However, if the first optical path OP1 that guides the image of the upper field of view and the second optical path OP2 that guides the image of the lower field of view are not parallel to the perpendicular line of the substrate S surface (and the surface of the chip component C) due to the tilt of the two-field recognition means 100 when it is installed, the result will be as shown in Figure 14, and the image acquired by the imaging means 2 will be as shown in Figures 15(b) and 15(c). In other words, even though the chip component C and the substrate S are aligned and positioned parallel to each other, a misalignment will be detected.

[0010] Here, since the first optical path OP1 that guides the image of the upper field of view and the second optical path OP2 that guides the image of the lower field of view are on the same optical axis, it is clear that aligning the optical axis of the two-field of view recognition means perpendicular to the surface of the substrate S (and the surface of the chip component C) is important for alignment accuracy.

[0011] Therefore, as a method for aligning the optical axis of the two-field recognition means, as shown in Figures 13 and 14, it is possible to use a measurement target that is fixed in such a state that the recognition mark of the second surface lies on the perpendicular line of the recognition mark of the first surface, and then detect and adjust the tilt of the optical axis from the positional relationship of both recognition marks in the image acquired by the imaging means.

[0012] However, even if materials with minimal thermal deformation are used for the first and second surfaces, the positions of the upper and lower recognition marks may change slightly due to temperature and humidity changes. Therefore, even if this change is only a few micrometers, it cannot be used for alignment requiring submicron accuracy.

[0013] The present invention has been made in consideration of the above-mentioned problems, and provides an optical axis deviation evaluation means and optical axis adjustment means, or an optical axis deviation evaluation method and optical axis adjustment method, which are capable of evaluating and adjusting the optical axis deviation of a two-viewpoint recognition means with high accuracy. [Means for solving the problem]

[0014] In order to solve the above problem, the invention described in claim 1 is as follows: An optical axis misalignment evaluation means for evaluating the optical axis misalignment of two field-of-view recognition means installed between a first surface and a second surface arranged parallel to each other, a first object disposed on the first surface side and having a minute through-hole; and a laser irradiation means for irradiating a laser beam in a direction perpendicular to the second surface through the minute through-hole; a second object provided on the second surface, emitting a wavelength different from that of the laser light in response to the wavelength of the laser light; and a control unit having a function of analyzing the image acquired by the two-view recognition means; The oscillation wavelength of the laser light is outside the sensitivity range of the two-field-of-view recognition means, which recognizes the minute through-hole in the first subject and also recognizes an emission point of a wavelength different from that of the laser light emitted by the second subject, and the control unit is an optical axis deviation evaluation means which evaluates the optical axis deviation from relative position information of the images of the minute through-hole and the emission point.

[0015] The invention described in claim 2 is the optical axis misalignment evaluation means described in claim 1, The optical axis shift evaluation means is configured so that the two-view recognition means includes a first optical path that guides a first image of the first surface, a second optical path that guides a second image of the second surface, a third optical path that is perpendicular to the first optical path and the second optical path, an optical element that guides the first image and the second image onto the third optical path while superimposing them, and an imaging means that captures the first image and the second image guided onto the third optical path.

[0016] The invention described in claim 3 is Optical axis adjustment means for adjusting the optical axis of the two field recognition means so that it is perpendicular to the first and second surfaces, An optical axis adjustment means for adjusting the optical axis of the two field recognition means based on the evaluation result of the optical axis misalignment evaluation means described in either claim 1 or claim 2.

[0017] The invention described in claim 4 uses the optical axis misalignment evaluation means described in either claim 1 or claim 2, The optical axis deviation evaluation method includes a through hole observation step of acquiring position information of the minute through hole on the first surface side, a light emitting point observation step of irradiating the laser light and acquiring position information of the light emitting point emitted on the second surface side, and an optical axis deviation calculation step of calculating at least the direction of the optical axis deviation from the position information of the minute through hole and the position information of the light emitting point.

[0018] The invention described in claim 5 is A method for adjusting the optical axis of the two field recognition means so that it is perpendicular to the first and second surfaces, This is an optical axis adjustment method for adjusting the optical axis of the field recognition means described in claim 4, based on the results obtained by the optical axis misalignment evaluation method described in claim 4. [Effects of the Invention]

[0019] The present invention enables high-precision evaluation and adjustment of the optical axis misalignment of a two-field recognition means, thereby improving the alignment accuracy in mounting devices that use a two-field recognition means. [Brief explanation of the drawings]

[0020] [Figure 1] This figure shows the configuration of the optical axis misalignment evaluation means according to an embodiment of the present invention. [Figure 2] This diagram illustrates the roles of the laser irradiation means, the first subject, and the second subject in the optical axis misalignment evaluation means according to an embodiment of the present invention. [Figure 3] This figure shows a state in which the laser beam emitted by the laser irradiation means of the optical axis misalignment evaluation means according to an embodiment of the present invention is parallel to the optical axis of the two-field recognition means. [Figure 4] This figure shows the state in which the two-field recognition means recognizes a minute through-hole using the optical axis misalignment evaluation means according to an embodiment of the present invention. [Figure 5] This figure shows the state in which the two-field recognition means recognizes the light emission point using the optical axis misalignment evaluation means according to an embodiment of the present invention. [Figure 6]FIG. 10 is a diagram showing a state in which the optical axis of the two-viewpoint recognition means is tilted with respect to the laser light irradiated by the laser irradiation means of the optical axis deviation evaluation means according to the embodiment of the present invention; [Figure 7] This diagram shows the positional relationship between the minute through-hole and the light-emitting point as observed by the two-field recognition means when the in-plane positions of the chip component and the substrate are aligned. The diagrams show: (a) when the optical axis of the two-field recognition means is perpendicular to the chip component and the substrate; (b) when the optical axis of the two-field recognition means is tilted in the X direction; and (c) when the optical axis of the two-field recognition means is tilted in both the X and Y directions. [Figure 8] FIG. 10 is a diagram showing the configuration of an optical axis deviation evaluation unit according to a modified example of the embodiment of the present invention. [Figure 9] FIG. 2 is a diagram showing a configuration including an optical axis adjusting unit according to an embodiment of the present invention. [Figure 10] FIG. 10 is a diagram showing the state in which a two-view recognition means is used when aligning a chip component with a substrate. [Figure 11] This is an example in which one imaging means acquires images of two fields of view. (a) shows a configuration in which both upper and lower optical paths are guided to the imaging means, and (b) is a top view of a two-field of view recognition means composed of a combination of one imaging means and an optical element. [Figure 12] FIG. 10 is a diagram showing an example in which a dichroic prism is used as an optical element for guiding the optical paths of the two fields of view toward the imaging means. [Figure 13] This shows a state in which the two-view recognition means is observing the chip recognition mark and the board recognition mark with the chip component and the board aligned in-plane. [Figure 14] This shows the state in which the chip recognition mark and the board recognition mark are observed with the optical axis of the two-view recognition means tilted and the in-plane positions of the chip component and the board aligned. [Figure 15] This diagram shows the positional relationship between the chip recognition mark and the substrate recognition mark as observed by the two-field recognition means when the in-plane positions of the chip component and the substrate are aligned. The diagrams show the cases when (a) the optical axis of the two-field recognition means is perpendicular to the chip component and the substrate, (b) the optical axis of the two-field recognition means is tilted in the X direction, and (c) the optical axis of the two-field recognition means is tilted in both the X and Y directions. DETAILED DESCRIPTION OF THE INVENTION

[0021] An embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic diagram for explaining the configuration of an optical axis deviation evaluation means 1 in the embodiment of the present invention. The optical axis deviation evaluation means 1 evaluates the optical axis deviation of the two-field of view recognition means 100, and more specifically, evaluates the inclination of the optical axis of the two-field of view recognition means 100, which is arranged between a chip component C and a substrate C that are arranged parallel and facing each other as shown in Fig. 10, with respect to a line perpendicular to both facing surfaces of the chip component C and the substrate S. Here, since the chip component C and the substrate S are usually parallel to a horizontal plane (XY plane), the inclination of the optical axis of the two-field of view recognition means 100 with respect to the Z-axis direction is often evaluated.

[0022] It should be noted that the use of the two-viewpoint recognition means 100 for evaluating optical axis deviation by the optical axis deviation evaluation means 1 of the present invention is not limited to the combination of chip component C and substrate S as shown in Fig. 10. In other words, the use is not limited as long as the two-viewpoint recognition means 100 is placed between two surfaces (first surface and second surface) arranged parallel to each other and acquires images of the first surface and the second surface, and the optical axis deviation evaluation means 1 can be used to evaluate the inclination of the optical axis of the two-viewpoint recognition means 100 with respect to the perpendicular to the first surface and the second surface.

[0023] In FIG. 1, the two-viewpoint recognition means 100 is a target for which the optical axis deviation evaluation means 1 evaluates optical axis deviation. The two-viewpoint recognition means 100 shown in FIG. 1 is composed of an imaging means 2 and an optical element 3. As in the example shown in FIG. 11(a), the optical element 3 includes a half mirror 31 and a mirror 32 as components. As shown in FIG. 11(a), the two-viewpoint recognition means 100 reflects an upper view field image, which passes through the first optical path OP1 indicated by the dashed-dotted line, off the surface 31B of the half mirror 31 toward the mirror 32, reflects it off the mirror surface 32M of the mirror 32, and transmits it through the half mirror 31, where it is captured by the imaging means 2 along the third optical path OP3. In addition, the lower view field image, which passes through the second optical path OP2 indicated by the dashed-dotted line, is reflected off the surface 31A of the half mirror 31 and captured by the imaging means 2 along the third optical path OP3.

[0024] Here, the first optical path OP1 and the second optical path OP2 are aligned along the same straight line. Therefore, it can be said that the first optical path OP1 and the second optical path OP2 form the optical axis of the two-viewpoint recognizing means 100.

[0025] The optical axis deviation evaluation means 1 of the present invention includes, as its constituent elements, a first subject 6, a laser irradiation means 7, a second subject 8, and a control unit 9. In the embodiment of the present invention, the first subject 6 and the second subject 8 are arranged parallel to a horizontal plane, and the inclination of the optical axis of the two-view field recognition means 100 with respect to the vertical direction perpendicular to the horizontal plane is evaluated.

[0026] The first subject 6 is made of a light-shielding material and has a minute through-hole 6H, and the laser irradiation device 7 irradiates laser light vertically downward (in the −Z direction). Here, it is desirable that the wavelength of the laser light is outside the sensitivity range of the imaging means 2 constituting the two-field recognition means 100. For this reason, light of the wavelength of the laser light is difficult to detect by the imaging means 2.

[0027] The second subject 8 responds to the wavelength of the laser light and emits light of a different wavelength from that of the laser light, but the wavelength of the light emitted by the second subject 8 in response to the laser light is within the sensitivity range of the imaging means 2. In other words, the light emitted by the second subject 8 in response to the laser light is detected by the imaging means. As shown in Figure 1, the second subject 8 is a plate-like object placed on a horizontal plane 80.

[0028] In the optical axis deviation evaluation means 1 of the embodiment shown in FIG. 1, the second subject 8 generates second harmonics of the received light due to a nonlinear optical phenomenon. For example, a laser detection target that emits visible light from an irradiated spot of near-infrared laser light can be used. Therefore, when using an imaging means 2 that is sensitive to wavelengths in the visible range, by setting the wavelength of the laser light emitted by the laser irradiation means to be in the near-infrared range, the second subject 8 that receives the laser light will emit visible light that can be detected by the imaging means 2. Here, the wavelength of the near-infrared range is preferably in the range of 1000 nm to 1400 nm.

[0029] In the optical axis deviation evaluation means 1 in Fig. 1, the control unit 9 essentially consists mainly of a CPU and a storage device, with interfaces interposed between each device as necessary. The control unit 9 also has a built-in program, which allows it to perform calculations using acquired data and output the results of the calculations. It is also desirable that the control unit 9 also has a function to record acquired data and calculation results and use them as new calculation data.

[0030] The control unit 9 is connected to the imaging means 2 of the two-view recognition means 100, and controls the image acquisition operation by imaging, and also has the function of importing imaging data and processing the imported image data to calculate position information, etc.

[0031] The control unit 9 is connected to the laser irradiation means 7 and controls the on / off of the laser irradiation. It may also have a function to adjust the laser irradiation output.

[0032] A method for evaluating the tilt of the optical axis of the two-viewpoint recognition means 100 using the optical axis deviation evaluation means 1 will be described below.

[0033] 2 shows a state in which the first subject 6 formed on the first surface side and the second subject 8 formed on the second surface side are horizontally opposed to each other, and the laser irradiation means 7 is irradiating the laser (without the two-viewpoint recognition means 100). Here, the first subject 6 and the second subject 8 forming the second surface are horizontal, and the laser irradiation means 7 irradiates the laser vertically downward from above the first subject 6 toward the second subject 8, so that the laser light LH that passes through the minute through-hole 6H in the first subject 6 is irradiated onto the second subject 8, and the irradiated spot portion emits visible light as a light-emitting point R8. Therefore, if the minute through-hole 6H is a hole that penetrates in the vertical direction, the shapes of the minute through-hole 6H and the light-emitting point R8 will be approximately the same.

[0034] Furthermore, since the light-emitting point R8 is located directly below the minute through-hole 6H in the vertical direction, the state in Fig. 2 can also be said to be a state in which the minute through-hole 6H and the light-emitting point R8 are aligned. Even if the in-plane position of the minute through-hole 6H in the first subject 6 changes due to thermal expansion or the like, the position of the light-emitting point R8 also changes accordingly, so the aligned state between the minute through-hole 6H and the light-emitting point R8 is always maintained.

[0035] Therefore, the optical axis deviation evaluation means 1 of the present invention evaluates the optical axis deviation of the two-field-of-view recognition means 100 using images of the minute through-hole 6H and the light-emitting point R8. In a configuration such as the two-field-of-view recognition means 100 that acquires two fields of view with one imaging means, as shown in FIG. 3, part of the laser light LH can pass through a half mirror 31 and irradiate the second subject 8. This makes it possible to observe both the minute through-hole 6H and the light-emitting point R8. In contrast, a two-field-of-view recognition means that has an imaging means for each field of view often has a configuration in which a mirror is provided for each field of view, making it difficult to irradiate the laser light LH onto the second subject 8, and is therefore unsuitable for application of the present invention.

[0036] FIG. 3 shows a state in which the optical axis of the two-view recognition means 100 is in the same direction as the laser light LH, i.e., the optical axis is vertical. In this state, FIGS. 4 and 5 show the process of acquiring images of the minute through-hole 6H and the light-emitting point R8.

[0037] FIG. 4 illustrates the through-hole observation process for acquiring positional information of the micro through-hole 6H from an image of the micro through-hole 6H. In the state shown in FIG. 4, the micro through-hole 6H is within the upper field of view of the two-field recognition means 100. The micro through-hole 6H is surrounded by the first object 6 made of a light-shielding material, allowing the inner portion of the micro through-hole 6H to be captured as a bright image. The image of the upper field of view is acquired by the imaging means 2 along the first optical path OP1, the optical element 3, and the third optical path OP3. If the brightness above the first object 6 is constant, the shape of the micro through-hole 6H can be recognized, and positional information of the micro through-hole 6H within the field of view can be acquired. If the imaging means 2 is not sensitive to the wavelength of the laser light, the same image can be obtained regardless of whether the laser irradiation device 7 is on or off.

[0038] FIG. 5 illustrates a light-emitting point observation process for acquiring position information of light-emitting point R8 from an image of light-emitting point R8 that appears on second subject 8 when irradiated with laser light that has passed through minute through-hole 6H. The image of light-emitting point R8, generated by turning on laser irradiation means 7 and irradiating it with laser light, falls within the lower field of view of two-view recognition means 100 in the state shown in FIG. 5. Because other parts of second subject 8 do not emit light, light-emitting point R8 can be captured as a bright image. The image of the lower field of view is acquired by imaging means 2 along third optical path OP3, passing through optical element 3 from third optical path OP2. If the output of laser irradiation means 7 is adjusted so that the brightness of light-emitting point R8 is constant, the shape of light-emitting point R8 can be recognized, and position information of light-emitting point R8 within the field of view can be acquired.

[0039] As mentioned above, if the minute through-hole 6H is a hole that penetrates in the vertical direction, the shapes of the minute through-hole 6H and the light-emitting point R8 will be approximately the same, but the light-emitting point R8 will have a color with a wavelength determined by the wavelength of the laser light (half the wavelength of the laser light), so it is easy to distinguish between the minute through-hole 6H and the light-emitting point R8. Also, in the above explanation, the explanation of the through-hole observation step and the light-emitting point observation step are separated, but the through-hole observation step and the light-emitting point observation step may be performed separately, or they may be performed simultaneously.

[0040] 4 and 5, the optical axis of the two-viewpoint recognition means 100 is oriented vertically and there is no optical axis misalignment. Therefore, in this state, the image captured by the imaging means 2 shows the minute through-hole 6H and the light-emitting point R8 overlapping as shown in FIG. 7(a).

[0041] In contrast, if the optical axis direction of the two-field recognition means 100 (the direction of the first optical path OP1 and the second optical path OP2) is tilted with respect to the vertical direction as shown in Figure 6, even if the positions of the micro-through hole 6H and the light-emitting point R8 are aligned, the image obtained by the imaging means 2 will detect the micro-through hole 6H and the light-emitting point R8 as being in separate positions, as shown in Figures 7(b) and 7(c). In other words, the tilt (of the optical axis) of the two-field recognition means 100 can be detected from the relative position information of the micro-through hole 6H and the light-emitting point R8. Furthermore, it is also possible to infer the direction and angle of the tilt of the optical axis from the relative positional relationship between the micro-through hole 6H and the light-emitting point R8 obtained by the imaging means 2.

[0042] Incidentally, in the optical axis misalignment evaluation means 1 shown in Figure 1, the wavelength of the laser light emitted by the laser irradiation means 7 is in the near-infrared region, but the present invention is not limited to this. For example, in the optical axis misalignment evaluation means 1001 shown in Figure 8, an ultraviolet shielding filter 21 is provided in the light receiving part of the imaging means 2. Furthermore, by setting the wavelength of the laser light emitted by the laser irradiation means 7 to the near-ultraviolet region and using a fluorescent material or phosphorescent material that converts near-ultraviolet light to visible light for the second subject 8, it is possible to observe the minute through-hole 6H and the light emission point R8.

[0043] As mentioned above, if the tilt direction and angle can be inferred from the relative positional relationship between the micro-through hole 6H and the light-emitting point R8, it is possible to adjust the orientation and angle of the optical axis of the two-field recognition means 100 so that the optical axis points in the vertical direction based on the results. An example of this is shown in Figure 9, where the optical axis adjustment means 10 is provided with the optical axis misalignment evaluation means 1 in Figure 1 and the optical axis drive unit 11 is provided with the two-field recognition means 100. The optical axis drive unit 11 is connected to the control unit 9 and is driven to correct the tilt direction or tilt angle of the optical axis obtained by the function of the optical axis misalignment evaluation means 1.

[0044] As described above, the optical axis deviation evaluation means of the present invention uses a laser irradiated in the vertical direction, so the minute through-hole and the light-emitting part are always aligned, making it possible to evaluate the optical axis deviation with high precision, and by adjusting the optical axis based on the evaluation results of this optical axis deviation, accurate alignment using the two-view recognition means becomes possible. By using this in a mounting device, high-precision mounting can be performed. [Explanation of symbols]

[0045] 1. Optical axis misalignment evaluation means 2. Imaging means 3 Optical elements 6. First subject 6H Micro through hole 7. Laser irradiation means 8. Second subject 9 Control Unit 10 Optical axis adjustment means 11 Optical axis drive unit 21 UV-blocking filter 31 Half Mirror 31A, 31B (half-mirror) surface 32 Mirror 32M mirror surface 80 horizontal plane 100, 101 2 visual field recognition means 300 optical elements OP1 1st optical path OP2 2nd optical path OP3 3rd optical path L laser light LH Microscopic through hole transmitted light R8 Light source

Claims

1. An optical axis deviation evaluation means for evaluating an optical axis deviation of a two-viewpoint recognition means installed between a first surface and a second surface arranged in parallel and facing each other, a first object disposed on the first surface side and having a minute through-hole; a laser irradiation means for irradiating the second surface with a laser beam in a direction perpendicular to the second surface through the minute through-hole; a second object provided on the second surface, which emits a wavelength different from that of the laser light in response to the wavelength of the laser light; a control unit having a function of analyzing the image acquired by the two-viewpoint recognition means, The oscillation wavelength of the laser light is outside the sensitivity range of the two-field recognition means, the two-viewpoint recognition means recognizes the minute through-hole in the first object and recognizes a light-emitting point of a wavelength different from that of the laser light emitted in the second object, The control unit evaluates optical axis deviation based on relative position information of the image of the minute through-hole and the image of the light-emitting point.

2. 2. The optical axis deviation evaluation means according to claim 1, The optical axis shift evaluation means is configured so that the two-view recognition means has a first optical path that guides a first image of the first surface, a second optical path that guides a second image of the second surface, a third optical path that is perpendicular to the first optical path and the second optical path, an optical element that guides the first image and the second image onto the third optical path while superimposing them, and an imaging means that captures the first image and the second image guided onto the third optical path.

3. an optical axis adjusting means for adjusting the optical axis of the two-viewpoint recognition means so that it is perpendicular to the first surface and the second surface, 3. An optical axis adjusting means for adjusting the optical axis of said two-view recognition means based on the evaluation result of the optical axis deviation evaluating means according to claim 1.

4. Using the optical axis deviation evaluation means according to claim 1 or 2, a through-hole observation step of acquiring position information of the minute through-holes on the first surface side; a light-emitting point observation step of irradiating the laser light and acquiring position information of the light-emitting point emitted on the second surface side; The optical axis deviation evaluation method includes an optical axis deviation calculation step of calculating at least the direction of the optical axis deviation from the position information of the minute through-hole and the position information of the light emitting point.

5. An optical axis adjustment method for adjusting an optical axis of the two-viewpoint recognition means so that the optical axis is perpendicular to the first surface and the second surface, 5. A method for adjusting an optical axis of the second visual field recognition means based on a result obtained by the method for evaluating an optical axis deviation according to claim 4.

Images