Irradiation target and method

Abstract

The present invention is for making a hole that is formed in a surface opposite to an irradiated surface of an irradiation target approach perfect circularity.　An irradiation target according to the present invention comprises a first surface and a second surface which is on the opposite side to the first surface. A through hole that penetrates the first surface and the second surface is formed in the irradiation target by irradiating the first surface using an irradiation device with a focal point positioned between the first surface and the second surface.

Description

Irradiation object and method

[0001] The present invention relates to an object to be irradiated and the like.

[0002] Conventionally, as in Patent Document 1, an irradiation object (sample) that is irradiated with laser light has been proposed.

[0003] Japanese Patent Application Laid-Open No. 2022-097265

[0004] However, in some cases, the laser beam is focused so that the focal position is on the surface of the object to be irradiated (sample). In this case, when a through-hole is formed in the object to be irradiated by the laser beam, the hole on the surface opposite to the irradiated surface may have an irregular shape that is not a perfect circle.

[0005] One example of an object of the present invention is to make holes formed on the surface opposite to the irradiated surface of an object to be irradiated nearly perfectly circular. Other objects of the present invention will become apparent from the description of this specification.

[0006] One aspect of the present invention is an irradiation object comprising a first surface and a second surface opposite the first surface, wherein a through hole penetrating the first surface and the second surface is formed by irradiating the first surface from an irradiation device having a focal position between the first surface and the second surface.

[0007] According to the above aspect of the present invention, the hole formed on the surface opposite to the irradiated surface of the irradiation object can be made nearly perfect circular.

[0008] 1 is a perspective view of the drilling set of this embodiment, and is a perspective view showing the positional relationship between the irradiation device and the irradiation object in the second pattern. FIG. 2 is a cross-sectional perspective view of the irradiation object in which a through hole has been formed. FIG. 3 is a cross-sectional perspective view of the irradiation object that has been plated, filled with elastomer, and attached with contact pads, and is a perspective view of the contact pin. FIG. 4 is a perspective view showing the positional relationship between the irradiation device and the irradiation object in the first pattern. FIG. 5 is a perspective view showing the positional relationship between the irradiation device and the irradiation object in the third pattern. FIG. 6 is a perspective view showing the positional relationship between the irradiation device and the irradiation object in the fourth pattern. FIG. 7 is a box-and-whisker plot of the first diameter in the first experimental example. FIG. 8 is a box-and-whisker plot of the second diameter in the first experimental example. FIG. 9 is a box-and-whisker plot of the circularity of the hole on the second surface in the first experimental example. FIG. 10 is a box-and-whisker plot of the first diameter in the second experimental example. FIG. 11 is a box-and-whisker plot of the second diameter in the second experimental example. FIG. 12 is a box-and-whisker plot of the circularity of the hole on the second surface in the second experimental example.

[0009] The present embodiment will be described below with reference to the drawings. However, the embodiments are not limited to the following embodiments. Furthermore, the content described in one embodiment is, in principle, also applicable to other embodiments. Furthermore, the embodiments and modifications can be combined as appropriate. In FIG. 1, the area in which the through-hole 20 is formed by the laser light from the irradiation device 30 is indicated by a dotted line. Furthermore, in FIG. 1 and FIGS. 4 to 6, hatching of the cross section of the front surface of the irradiation target 10 is omitted, and the optical path of the laser light irradiated from the irradiation device 30 is indicated by a dashed line.

[0010] (Drilling Set 1) As shown in FIG. 1, the drilling set 1 according to this embodiment includes an irradiation object 10 and an irradiation device 30.

[0011] (Irradiation object 10) The irradiation object 10 is a plate-like object made of a silicone rubber sheet and has a first surface 11 and a second surface 12. The second surface 12 is located on the opposite side to the first surface 11. A through hole 20 is formed in the irradiation object 10 by irradiating the first surface 11 of the irradiation object 10 with laser light from the irradiation device 30.

[0012] (Irradiation Device 30) The irradiation device 30 emits laser light, for example, femtosecond laser light. However, the irradiation device 30 may be configured to emit laser light other than femtosecond laser light.

[0013] (Positional Relationship Between Irradiation Object 10 and Irradiation Device 30) When forming a through-hole 20 in the irradiation object 10 by irradiating it with laser light, the irradiation device 30 is installed to meet the following conditions (first to third conditions) (focal position setting process). First condition: The irradiation device 30 irradiates the first surface 11 of the irradiation object 10 with laser light. Second condition: A position that is a depth Z away from the first surface 11 of the irradiation object 10 becomes the focal position P of the irradiation device 30. In other words, the lens of the irradiation device 30 focuses the laser light emitted from the irradiation device 30 so that the focal position P of the laser light is a position that is a depth Z away from the first surface 11. In other words, the distance between the position that is a depth Z (a predetermined depth) away from the first surface 11 and the irradiation device 30 is equal to the focal length F1 of the irradiation device 30. The alignment of the irradiation object 10 with the irradiation device 30 is performed, for example, by moving a stage (not shown) that holds the irradiation object 10 while keeping the irradiation device 30 fixed. Third condition: The depth Z is approximately half the thickness of the irradiation object 10.

[0014] Therefore, laser light is irradiated from the irradiation device 30 onto the first surface 11 with a region of a predetermined depth (such as an intermediate region) between the first surface 11 and the second surface 12, away from the first surface 11, at the focal position P (irradiation process).

[0015] 2, a through hole 20 is formed in the irradiation object 10 by laser light from the irradiation device 30. The through hole 20 has a generally truncated cone shape with a larger diameter (first diameter d1) on the first surface 11 side and a smaller diameter (second diameter d2) on the second surface 12 side.

[0016] For example, as shown in FIG. 3 , the inner wall of the through hole 20 is coated with a metal thin film 13 by plating (coating process). The space inside the region of the inner wall of the through hole 20 coated with the metal thin film 13 is filled with an elastomer 14 (filling process). The through hole 20 coated with the metal thin film 13 and filled with the elastomer 14 is used as a through hole. A first contact pad 11a is attached to the opening of the through hole 20 on the first surface 11 (attaching process). The irradiation object 10 having the through hole 20 for the through hole formed therein and the first contact pad 11a attached thereto is used, for example, as an inspection board. A contact pin 50 is pressed against the first contact pad 11a during inspection. A second contact pad 12a may also be attached to the opening of the through hole 20 on the second surface 12. However, the irradiation object 10 having the through hole 20 formed therein may be used for other purposes.

[0017] (Effect of setting the focal position inside the irradiation object 10 rather than on the surface of the irradiation object 10) When irradiating the irradiation object 10 with laser light, the irradiation object 10 and the irradiation device 30 are generally aligned so that the focal position of the laser light emitted from the irradiation device 30 is on the surface (first surface 11) of the irradiation object 10. In this case, the difference in the irradiation degree of the laser light (the difference in energy applied from the laser light) between the region close to the focal position (first surface 11) and the region away from the focal position (second surface 12) becomes large, and there is a possibility that the hole formed in the second surface 12 will have an irregular shape that is different from a perfect circle.

[0018] In this embodiment, the irradiation object 10 and the irradiation device 30 are aligned so that the focal position P of the laser light emitted from the irradiation device 30 is located inside the irradiation object 10, away from the first surface 11, specifically in the region between the front surface (first surface 11) and the back surface (second surface 12) of the irradiation object 10. Therefore, compared to a mode in which laser light is irradiated with the focal position P on the first surface 11, in this embodiment, the difference in the irradiation intensity of the laser light between the first surface 11 and the second surface 12 is smaller, and a hole that is close to a perfect circle can be formed in the second surface 12.

[0019] In particular, when the irradiation object 10 and the irradiation device 30 are aligned so that the focal position P of the laser light emitted from the irradiation device 30 is in the intermediate region between the front surface (first surface 11) and the back surface (second surface 12) of the irradiation object 10 (a region at a depth half the distance between the first surface 11 and the second surface 12), the laser light can be irradiated in a well-balanced manner near the focal position P on both the first surface 11 and the second surface 12. Furthermore, compared to a mode in which the laser light is irradiated with the focal position P on the first surface 11, the hole formed in the second surface 12 is larger. When the hole in the second surface 12 is larger, the hole in the second surface 12 is less likely to be blocked, and material scraped by the laser light can be more easily discharged through the hole in the second surface 12. This makes it easier to remove scorch caused by the laser light near the hole in the second surface 12, reducing the possibility of insufficient coating of the metal thin film 13 and insufficient filling of the elastomer 14.

[0020] (First Experimental Example) Laser light was irradiated by changing the focal position to form nine holes each, and the diameter (incident diameter) of the holes formed on the first surface 11, the diameter (exit diameter) of the holes formed on the second surface 12, and the circularity of the holes formed on the second surface 12 were compared.

[0021] A silicone rubber sheet with a thickness of 500 μm was used as the irradiation target 10. Laser light irradiation was performed using an irradiation device 30 that emits a femtosecond laser in the following four patterns. Specifically, laser light irradiation was performed in a first pattern (see FIG. 4, Z = 0) in which the surface of the first surface 11 was the focal position P. Laser light irradiation was also performed in a second pattern (see FIG. 1, Z = 250 μm) in which the focal position P was 250 μm away from the surface of the first surface 11 (the midpoint between the first surface 11 and the second surface 12). Laser light irradiation was also performed in a third pattern (see FIG. 5, Z = 375 μm) in which the focal position P was 375 μm away from the surface of the first surface 11. Laser light irradiation was also performed in a fourth pattern (see FIG. 6, Z = 500 μm) in which the focal position P was 500 μm away from the surface of the first surface 11 (the surface of the second surface 12).

[0022] For each pattern, the maximum, minimum, first quartile, second quartile, third quartile, and average value of the diameters (incident diameter, first diameter d1) of the nine holes formed on the first surface 11 were calculated. Furthermore, for each pattern, the maximum, minimum, first quartile, second quartile, third quartile, and average value of the diameters (exit diameter, second diameter d2) of the nine holes formed on the second surface 12 were calculated. Furthermore, for each pattern, the maximum, minimum, first quartile, second quartile, third quartile, and average value of the circularity of the nine holes formed on the second surface 12 were calculated. Circularity is calculated by dividing the difference in the radii of two concentric geometric circles (radius of the maximum circle - radius of the minimum circle) by 2. The smaller the circularity value, the closer the hole is to a perfect circle.

[0023] The first quartile is the number at 25% of the data when sorted from smallest to largest (the value in the middle of the lowest data). The second quartile is the number at 50% of the data when sorted from smallest to largest (the value in the middle of the data). The third quartile is the number at 75% of the data when sorted from smallest to largest (the number in the middle of the highest data). The maximum is the largest value of the data excluding outliers. The minimum is the smallest value of the data excluding outliers. An outlier is a data value that is greater than the value obtained by adding 1.5 times the difference between the third quartile and the first quartile to the third quartile, or a data value that is smaller than the value obtained by subtracting 1.5 times the difference between the third quartile and the first quartile from the first quartile.

[0024] Based on these calculated values, a box plot of the diameters of the holes formed on the first surface 11 was created (see FIG. 7 ). For the first pattern, the minimum diameter of the holes formed on the first surface 11 was 78.1 μm, the first quartile was 79.1 μm, the average was 82.3 μm, the second quartile was 82.8 μm, the third quartile was 84.7 μm, and the maximum was 86.9 μm. For the second pattern, the minimum diameter of the holes formed on the first surface 11 was 80.1 μm, the first quartile was 81.3 μm, the average was 84.6 μm, the second quartile was 84.1 μm, the third quartile was 87.5 μm, and the maximum was 90.8 μm. In the third pattern, the minimum diameter of the holes formed on the first surface 11 was 78.0 μm, the first quartile was 78.6 μm, the average was 79.8 μm, the second quartile was 79.4 μm, the third quartile was 81.2 μm, and the maximum was 81.7 μm. In the fourth pattern, the minimum diameter of the holes formed on the first surface 11 was 75.0 μm, the first quartile was 77.5 μm, the average was 78.5 μm, the second quartile was 78.1 μm, the third quartile was 80.2 μm, and the maximum was 80.9 μm.

[0025] Based on these calculated values, a box-and-whisker plot of the diameters of the holes formed on the second surface 12 was also created (see FIG. 8 ). For the first pattern, the minimum diameter of the holes formed on the second surface 12 was 25.7 μm, the first quartile was 30.1 μm, the average was 32.4 μm, the second quartile was 33.5 μm, the third quartile was 35.2 μm, and the maximum was 36.0 μm. For the second pattern, the minimum diameter of the holes formed on the second surface 12 was 29.7 μm, the first quartile was 30.6 μm, the average was 32.1 μm, the second quartile was 32.2 μm, the third quartile was 33.9 μm, and the maximum was 34.5 μm. In the third pattern, the minimum diameter of the holes formed on the second surface 12 was 24.9 μm, the first quartile was 25.6 μm, the average was 28.9 μm, the second quartile was 30.4 μm, the third quartile was 31.6 μm, and the maximum was 32.0 μm. In the fourth pattern, the minimum diameter of the holes formed on the second surface 12 was 22.3 μm, the first quartile was 23.4 μm, the average was 24.8 μm, the second quartile was 25.1 μm, the third quartile was 25.8 μm, and the maximum was 27.7 μm.

[0026] Based on these calculated values, a box plot of the circularity of the holes formed on the second surface 12 was also created (see FIG. 9 ). For the first pattern, the minimum value of the circularity of the holes formed on the second surface 12 was 2.3 μm, the first quartile was 3.3 μm, the average value was 4.3 μm, the second quartile was 4.4 μm, the third quartile was 4.9 μm, the maximum value was 4.9 μm, and one outlier was 7.4 μm. For the second pattern, the minimum value of the circularity of the holes formed on the second surface 12 was 1.5 μm, the first quartile was 1.7 μm, the average value was 2.3 μm, the second quartile was 2.0 μm, the third quartile was 3.1 μm, and the maximum value was 3.5 μm. For the third pattern, the minimum value of the circularity of the holes formed on the second surface 12 is 1.6 μm, the first quartile is 1.8 μm, the average value is 2.3 μm, the second quartile is 2.2 μm, the third quartile is 2.8 μm, and the maximum value is 3.7 μm. For the fourth pattern, the minimum value of the circularity of the holes formed on the second surface 12 is 0.8 μm, the first quartile is 1.2 μm, the average value is 1.8 μm, the second quartile is 2.0 μm, the third quartile is 2.4 μm, and the maximum value is 2.8 μm.

[0027] In a box plot, the horizontal line at the bottom of the whiskers indicates the minimum value, the horizontal line at the top of the whiskers indicates the maximum value, the horizontal line at the bottom of the box indicates the first quartile, the horizontal line at the top of the box indicates the third quartile, the horizontal line inside the box indicates the second quartile, the cross mark indicates the mean value, and the black mark indicates an outlier.

[0028] (Trends in incident diameter) Compared to the mode in which laser light irradiation is performed in the first pattern, the mode in which laser light irradiation is performed in the second pattern tends to result in larger diameters of holes formed on the first surface 11 (see FIG. 7 ). Compared to the conventional mode in which laser light irradiation is performed in the first pattern, the modes in which laser light irradiation is performed in the third and fourth patterns tend to result in smaller diameters of holes formed on the first surface 11.

[0029] (Trends in emission diameter) In the conventional mode in which laser light irradiation is performed in the first pattern, the diameter of the holes formed on the second surface 12 tended to be approximately the same as the diameter of the holes formed on the second surface 12 in the mode in which laser light irradiation is performed in the second pattern (see FIG. 8). Compared to the conventional mode in which laser light irradiation is performed in the first pattern, the diameter of the holes formed on the second surface 12 tended to be smaller in the modes in which laser light irradiation is performed in the third and fourth patterns.

[0030] (Trends in circularity) Compared to the conventional form in which laser light is irradiated in the first pattern, the forms in which laser light is irradiated in the second to fourth patterns show a tendency for the circularity of the holes formed on the second surface 12 to become smaller (tend to become closer to a perfect circle) (see Figure 9).

[0031] (Second Experimental Example) Laser light was irradiated by changing the focal position, forming 605 holes each, and the diameter (incident diameter) of the holes formed on the first surface 11, the diameter (exit diameter) of the holes formed on the second surface 12, and the circularity of the holes formed on the second surface 12 were compared.

[0032] A silicone rubber sheet having a thickness of 500 μm was used as the irradiation object 10. Laser light irradiation was performed using an irradiation device 30 that emits a femtosecond laser in the following two patterns. Specifically, laser light irradiation was performed in a first pattern (see FIG. 4, Z=0) in which the surface of the first surface 11 was set as the focal position P. Laser light irradiation was also performed in a second pattern (see FIG. 1, Z=250 μm) in which the focal position P was set at a position 250 μm away from the surface of the first surface 11 (the midpoint between the first surface 11 and the second surface 12).

[0033] For each pattern, the maximum value, minimum value, first quartile, second quartile, third quartile, and average value of the diameter (incident diameter, first diameter d1) of the 605 holes formed on the first surface 11 were calculated. Furthermore, for each pattern, the maximum value, minimum value, first quartile, second quartile, third quartile, and average value of the diameter (exit diameter, second diameter d2) of the 605 holes formed on the second surface 12 were calculated. Furthermore, for each pattern, the maximum value, minimum value, first quartile, second quartile, third quartile, and average value of the circularity of the 605 holes formed on the second surface 12 were calculated.

[0034] Based on these calculated values, a box plot of the diameters of the holes formed on the first surface 11 was created (see FIG. 10 ). For the first pattern, the minimum diameter of the holes formed on the first surface 11 was 78.1 μm, the first quartile was 82.6 μm, the average was 84.2 μm, the second quartile was 84.3 μm, the third quartile was 85.9 μm, and the maximum was 90.1 μm. For the second pattern, the minimum diameter of the holes formed on the first surface 11 was 81.4 μm, the first quartile was 87.2 μm, the average was 89.4 μm, the second quartile was 89.6 μm, the third quartile was 91.7 μm, the maximum was 98.1 μm, and the largest outlier was 98.4 μm.

[0035] Based on these calculated values, a box-and-whisker plot of the diameters of the holes formed on the second surface 12 was also created (see FIG. 11 ). For the first pattern, the minimum diameter of the holes formed on the second surface 12 was 23.4 μm, the first quartile was 28.7 μm, the average was 30.3 μm, the second quartile was 30.5 μm, the third quartile was 32.3 μm, the maximum was 36.9 μm, and the smallest outlier was 18.6 μm. For the second pattern, the minimum diameter of the holes formed on the second surface 12 was 25.5 μm, the first quartile was 30.6 μm, the average was 32.2 μm, the second quartile was 32.5 μm, the third quartile was 34.0 μm, the maximum was 39.1 μm, and the smallest outlier was 22.4 μm.

[0036] Based on these calculated values, a box-and-whisker plot of the circularity of the holes formed on the second surface 12 was also created (see FIG. 12 ). For the first pattern, the minimum value of the circularity of the holes formed on the second surface 12 was 1.4 μm, the first quartile was 4.6 μm, the average value was 6.0 μm, the second quartile was 5.9 μm, the third quartile was 7.3 μm, the maximum value was 10.9 μm, and the largest outlier was 11.7 μm. For the second pattern, the minimum value of the circularity of the holes formed on the second surface 12 was 0.8 μm, the first quartile was 2.5 μm, the average value was 3.4 μm, the second quartile was 3.2 μm, the third quartile was 4.2 μm, the maximum value was 6.7 μm, and the largest outlier was 8.5 μm.

[0037] (Trends in incident diameter) Compared to the conventional form in which laser light is irradiated in the first pattern, the form in which laser light is irradiated in the second pattern showed a tendency for the diameter of the hole formed on the first surface 11 to be larger (see Figure 10).

[0038] (Trends in emission diameter) Compared to the conventional form in which laser light is irradiated in the first pattern, the form in which laser light is irradiated in the second pattern showed a tendency for the diameter of the hole formed on the second surface 12 to be larger (see Figure 11).

[0039] (Trends in circularity) Compared to the conventional form in which laser light is irradiated in the first pattern, the form in which laser light is irradiated in the second pattern showed a tendency for the circularity of the holes formed on the second surface 12 to be smaller (tend to be closer to a perfect circle) (see Figure 12).

[0040] In the second to fourth patterns of the first experimental example and the second pattern of the second experimental example, the focal position P of the laser light emitted from the irradiation device 30 was set to be inside the irradiation object 10, away from the first surface 11, specifically, in the region between the front surface (first surface 11) and the back surface (second surface 12) of the irradiation object 10. In this case, compared to the mode in which the laser light was irradiated with the focal position P on the first surface 11 (first pattern of the first experimental example and the second experimental example), it was possible to form a hole that was close to a perfect circle on the second surface 12.

[0041] In particular, in the second pattern of the first experimental example and the second experimental example, the focal position P of the laser light emitted from the irradiation device 30 was set to an intermediate region (a region with a depth half the distance between the first surface 11 and the second surface 12) between the front surface (first surface 11) and the back surface (second surface 12) of the irradiation target 10. Compared to the mode in which the laser light was irradiated with the focal position P on the first surface 11 (the first pattern of the first experimental example and the second experimental example), it was possible to form holes in the second surface 12 with diameters roughly the same as or larger than that of the mode in which the laser light was irradiated with the focal position P on the first surface 11 (the first pattern of the first experimental example and the second experimental example).

[0042] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

[0043] According to the present specification, the following aspects of the irradiation object are provided: (Aspect 1) Aspect 1 includes a first surface and a second surface opposite to the first surface, and a through-hole penetrating the first surface and the second surface is formed by irradiating the first surface from an irradiation device with a focal position between the first surface and the second surface.

[0044] According to the above-described aspect, the distance between the focal position and the second surface is shorter than in a case where irradiation is performed with the focal position on the first surface, and a hole that is close to a perfect circle can be formed on the second surface.

[0045] (Aspect 2) In aspect 2, the distance between the first surface and the focal position is half the distance between the first surface and the second surface.

[0046] According to the above-described embodiment, the laser beam can be irradiated in a well-balanced manner on both the first and second surfaces near the focal position. Furthermore, the holes formed on the second surface are larger than in a configuration in which irradiation is performed with the focal position on the first surface. The larger holes on the second surface make them less likely to become clogged, making it easier to expel material removed by the laser beam through the holes on the second surface.

[0047] (Aspect 3) In aspect 3, the irradiation object is made of a silicone rubber sheet, the inner wall of the through hole is coated with a metal thin film, and the space in the area of ​​the inner wall of the through hole coated with the metal thin film is filled with elastomer.

[0048] According to the above-described embodiment, it is possible to easily remove scorch in the vicinity of the holes on the second surface, and to reduce the possibility of insufficient coating of the metal thin film and insufficient filling of the elastomer.

[0049] According to the present specification, there are provided methods having the following aspects.

[0050] (Aspect 4) Aspect 4 includes a focal position setting step of aligning an irradiation object having a first surface and a second surface opposite the first surface with an irradiation device, and an irradiation step of using the irradiation device to irradiate the irradiation object in the positional relationship set in the focal position setting step to form a through hole in the irradiation object, wherein the alignment sets the area between the first surface and the second surface as the focal position.

[0051] According to the above-described aspect, the distance between the focal position and the second surface is shorter than in a case where irradiation is performed with the focal position on the first surface, and a hole that is close to a perfect circle can be formed on the second surface.

[0052] (Aspect 5) In aspect 5, the distance between the first surface and the focal position is half the distance between the first surface and the second surface.

[0053] According to the above-described embodiment, the laser beam can be irradiated in a well-balanced manner on both the first and second surfaces near the focal position. Furthermore, the holes formed on the second surface are larger than in a configuration in which irradiation is performed with the focal position on the first surface. The larger holes on the second surface make them less likely to become clogged, making it easier to expel material removed by the laser beam through the holes on the second surface.

[0054] (Aspect 6) In Aspect 6, the irradiation object is made of a silicone rubber sheet, and the method further includes a coating step of coating an inner wall of the through hole with a metal thin film, and a filling step of filling an elastomer into a space inside the region of the inner wall of the through hole coated with the metal thin film.

[0055] According to the above-described embodiment, it is possible to easily remove scorch in the vicinity of the holes on the second surface, and to reduce the possibility of insufficient coating of the metal thin film and insufficient filling of the elastomer.

[0056] 1 Perforation set, 10 Irradiation object, 11 First surface, 11a First contact pad, 12 Second surface, 12a Second contact pad, 13 Metal thin film, 14 Elastomer, 20 Through hole, 30 Irradiation device, 50 Contact pin, d1 First diameter, d2 Second diameter, F1 Focal length of irradiation device, P Focal position of irradiation device, Z Depth from first surface

Claims

1. Page 1 and, A second surface opposite to the first surface, An object to be irradiated, wherein a through-hole is formed between the first surface and the second surface by irradiating the first surface with a femtosecond laser from an irradiation device that irradiates with a femtosecond laser, with the focal position being between the first surface and the second surface.

2. The irradiated object according to claim 1, wherein the distance between the first surface and the focal position is half the distance between the first surface and the second surface.

3. The object to be irradiated is made of a silicone rubber sheet. The inner wall of the through hole is covered with a thin metal film. The irradiated object according to claim 1 or claim 2, wherein the space in the region of the inner wall of the through hole that is covered with the metal thin film is filled with an elastomer.

4. A method for forming a through hole in an object to be irradiated, having a first surface and a second surface opposite to the first surface, A focal position setting step involves setting the focal position of the irradiation device that irradiates with a femtosecond laser relative to the object to be irradiated, The process includes an irradiation step of irradiating the first surface with the femtosecond laser to form the through hole, In the focal position setting step, the focal position is set to the region between the first surface and the second surface. A forming method comprising the irradiation step of irradiating the first surface which is set as the focal point.

5. The forming method according to claim 4, wherein the distance between the first surface and the focal position is half the distance between the first surface and the second surface.

6. The object to be irradiated is made of a silicone rubber sheet. A coating step of coating the inner wall of the through hole with a thin metal film, The forming method according to claim 4 or 5, further comprising a filling step of filling the space inside the region of the inner wall of the through hole that is covered with the metal thin film with an elastomer.