Lid body, package for mounting optical element, optical device, and optical module

Abstract

This lid body comprises: a transparent plate body having a first surface and a second surface positioned on the opposite side from the first surface; a first optical film positioned on the first surface; a second optical film positioned on the second surface; a first inclined part positioned at an edge portion of the first surface and inclined in a direction in which the thickness of the plate body decreases toward the end of the plate body; a second inclined part positioned at an edge portion of the first optical film and inclined in a direction in which the thickness of the first optical film decreases toward the end of the first optical film; and a third inclined part positioned at an edge portion of the second optical film and inclined in a direction in which the thickness of the second optical film decreases toward the end of the second optical film. In a plan view, the second inclined part is positioned outward of the third inclined part.

Description

Lid, package for mounting optical element, optical device and optical module

[0001] The present disclosure relates to a lid, a package for mounting an optical element, an optical device, and an optical module.

[0002] Japanese Unexamined Patent Publication No. 2000-171294 discloses a silicon infrared transmission window in which an infrared antireflection layer is formed on a silicon window material.

[0003] The lid according to the present disclosure comprises: a transparent plate body having a first surface and a second surface located opposite to the first surface; a first optical film located on the first surface; a second optical film located on the second surface; a first inclined portion located at an edge of the first surface, the first inclined portion being inclined in a direction that decreases the thickness of the plate body as it approaches the end of the plate body; a second inclined portion located at an edge of the first optical film, the second inclined portion being inclined in a direction that decreases the thickness of the first optical film as it approaches the end of the first optical film; and a third inclined portion located at an edge of the second optical film, the third inclined portion being inclined in a direction that decreases the thickness of the second optical film as it approaches the end of the second optical film, wherein in a plan view, the second inclined portion is located outward of the third inclined portion.

[0004] The package for mounting an optical element according to the present disclosure comprises: the above lid; a base body having a recess including a mounting portion for an optical element; and a bonding material that bonds the lid and the base body.

[0005] The optical device according to the present disclosure comprises: the above package for mounting an optical element; and an optical element mounted on the mounting portion.

[0006] The optical module according to the present disclosure comprises: the above optical device; and a module substrate on which the optical device is mounted.

[0007] This is a cross-sectional view showing the lid of Embodiment 1 of the present disclosure. This is a plan view showing the lid of Embodiment 1 of the present disclosure. This is an enlarged cross-sectional view showing the lid of Embodiment 1 of the present disclosure. This is a diagram showing a first example of incident or reflected light in Embodiment 1. This is a diagram showing a second example of incident or reflected light in Embodiment 1. This is a diagram showing a third example of incident or reflected light in Embodiment 1. This is a diagram showing a fourth example of incident or reflected light in Embodiment 1. This is a cross-sectional view showing the lid of Embodiment 2 of the present disclosure. This is a plan view showing the lid of Embodiment 2 of the present disclosure. This is an enlarged cross-sectional view showing the lid of Embodiment 2 of the present disclosure. This is a diagram showing a first example of incident or reflected light in Embodiment 2. This is a diagram showing a second example of incident or reflected light in Embodiment 2. This is a diagram showing a third example of incident or reflected light in Embodiment 2. This is a diagram showing a fourth example of incident or reflected light in Embodiment 2. This is a diagram showing a modified example 1 of the edge of the plate. This is a diagram showing a modified example 2 of the edge of the plate. This is a diagram showing a modified example 3 of the edge of the plate. This is a diagram showing a modified example 4 of the edge of the plate. This is a diagram showing a modified example 5 of the edge of the plate. This is a diagram showing a modified example 6 of the edge of the plate. This is a diagram showing a modified example 7 of the edge of the plate. This figure shows an optical element mounting package, optical device, and optical module according to Embodiment 1 of the present disclosure.

[0008] Embodiments of this disclosure will be described in detail below with reference to the drawings. In the following description, the direction perpendicular to the second surface S2, extending from the second surface S2 toward the first surface S1, will be referred to as the upward direction, and the direction along the second surface S2 will be referred to as the horizontal direction. The directions described in this description may differ from the directions used in actual use. The vertical direction also corresponds to the thickness direction of the plate body 10. In each figure, the dimensions of the members do not faithfully represent the dimensions and dimensional ratios of the actual constituent members. In the following description, "plan view" means viewing from above or below, or viewing through the frame. Also, "inclination angle" is expressed as the angle where, on the upper side, the plane parallel to the first surface S1 is 0° and the plane perpendicular to the first surface S1 is 90°, and on the lower side, the angle where, the plane parallel to the second surface S2 is 0° and the plane perpendicular to the second surface S2 is 90°.

[0009] (Embodiment 1) Figures 1A to 1C are a cross-sectional view, a plan view, and an enlarged cross-sectional view showing the lid 1 of Embodiment 1 of the present disclosure, respectively. Figures 2A to 2D are diagrams showing the first to fourth examples of incident light or reflected light, respectively. In Figures 2A to 2D, light is represented by dashed arrows.

[0010] The lid 1 according to this embodiment 1 may have the function of a lid that closes the opening of a recess (i.e., cavity) of the package. This function may also be a sealing function that makes the inside of the cavity airtight. In addition, the lid 1 may have the function of transmitting light and exerting an optical effect on the transmitted light. The optical effect may be a reflection reduction effect that reduces the reflection of light of a target wavelength, and the target wavelength may be in the ultraviolet region. The target wavelength may be any one of the ultraviolet regions from the UV-A, UV-B, UV-C, and DUV (deep ultraviolet) regions, or any multiple consecutive ultraviolet regions. The target wavelength may be in the DUV region. The wavelength range for UV-A is 400 to 315 [nm], the wavelength range for UV-B is 315 to 280 [nm], the wavelength range for UV-C is 280 to 200 [nm], and the wavelength range for deep ultraviolet is 200 [nm] or less. When the target wavelength is in the ultraviolet region, particularly the DUV region, the short wavelength of light means that if minute fragments or other particles are generated from the constituent material of the lid 1 and wander into the light path, noise is likely to be added to the transmitted light. Furthermore, when the target wavelength is in the ultraviolet region, particularly the DUV region, the short wavelength of light means that if there are minute chips or other irregularities in the light path or at the reflection points, noise is likely to be added to the transmitted light. Therefore, this embodiment aims to reduce the above-mentioned noise factors.

[0011] The lid 1 may comprise a transparent plate 10 having a first surface S1 and a second surface S2, a first optical film 20 located on the first surface S1, and a second optical film 30 located on the second surface S2, as shown in Figure 1A. The first surface S1 and the second surface S2 may be located on opposite sides of each other. The first optical film 20 and the second optical film 30 may be made of magnesium fluoride (MgF ２ ) It may also be a film. The first optical film 20 and the second optical film 30 can be formed using various film formation techniques for forming thin films.

[0012] The plate 10 may be rectangular in plan view, as shown in Figure 1B. In the case of a rectangular plate 10, the four corners in plan view may include chamfered shapes such as C-faces or R-faces. The size of the plate 10 is not particularly limited, but as an example, the width along one side may be 2 to 10 [mm], the thickness 0.2 to 1 [mm], and the chamfered shape may have a dimension of 0.1 to 0.2 [mm] along one side. The size of the plate 10 may also be a large size, for example, with a width along one side of 45 to 200 [mm]. The film thickness of the first optical film 20 and the second optical film 30 is not particularly limited, but as an example, it may be 20 to 50 [nm].

[0013] <Details of the lid 1 1> The plate body 10 may have a first inclined portion 11 on the edge of the first surface S1 that is inclined in a direction that reduces the thickness of the plate body 10 as it approaches the edge. The "direction of inclination" means a direction that reduces the thickness of the plate body 10 as it approaches the edge, compared to the thickness when there is no inclination (i.e., when the first surface S1 is spread out in a planar shape). The first inclined portion 11 may be located on the entire outer circumference of the plate body 10 in a planar view. The inclined surface of the first inclined portion 11 may be planar.

[0014] The first optical film 20 may have a second inclined portion 21 at its edge, which is inclined in a direction that reduces the thickness of the first optical film 20 as it approaches the edge. The "direction of inclination" means a direction that reduces the thickness of the first optical film 20 as it approaches the edge, compared to the thickness when there is no inclination (i.e., when the upper surface of the first optical film 20 is flat). The second inclined portion 21 may be located around the entire outer circumference of the first optical film 20 in a plan view. The inclined surface of the second inclined portion 21 may be flat.

[0015] The second optical film 30 may have a third inclined portion 31 at its edge, which is inclined in a direction that reduces the thickness of the second optical film 30 as it approaches the edge. The "direction of inclination" means a direction that reduces the thickness of the second optical film 30 as it approaches the edge, compared to the thickness when there is no inclination (i.e., when the lower surface of the second optical film 30 is flat). The third inclined portion 31 may be located around the entire outer circumference of the second optical film 30 in a plan view. The inclined surface of the third inclined portion 31 may be a curved surface, or even a convexly curved surface.

[0016] As shown in Figure 1B, in a plan view, the second inclined portion 21 may be located outward from the third inclined portion 31.

[0017] As described above, according to the lid 1 of Embodiment 1, the plate body 10 has a first inclined portion 11, which reduces the number of fragile parts of the plate body 10 (for example, sharp corners). Therefore, when handling the parts including the lid 1, it is possible to reduce the generation of fine fragments from fragile parts or the generation of fine irregularities on fragile parts due to stress or external force. In particular, when targeting light in the ultraviolet range such as the DUV range, fine fragments or fine irregularities can cause noise in the light transmitted through the lid 1. However, according to the lid 1 of Embodiment 1, the generation of fine fragments or fine irregularities is reduced, and noise in the light transmitted through the lid 1 can be reduced.

[0018] Furthermore, as shown in Figure 2A, the first inclined portion 11 of the plate body 10 and the second inclined portion 21 of the first optical film 20 can reflect light incident on the edge of the first optical film 20 and light incident on the edge of the plate body 10 outwards from the lid 1. This reflection reduces the transmission of light incident on the edges as noise through the lid 1.

[0019] Furthermore, as shown in Figure 2B, the third inclined portion 31 of the second optical film 30 allows unwanted incident light that enters through the first optical film 20 and then reaches the edge of the second optical film 30 to be reflected outward. This reflection reduces the amount of noise that reaches the edge of the second optical film 30, which mixes with the light that has been normally transmitted through the lid 1.

[0020] Furthermore, in a plan view, the second inclined portion 21 is located outward from the third inclined portion 31, so as shown in Figure 2C, a region A11 is obtained on the second surface S2 of the plate body 10 that is located outside the second optical film 30. This region A11 can then be used as a bonding surface to which the bonding material 130 is attached in order to bond the lid 1 (see Figure 7). Therefore, as shown in Figure 2C, it is possible to reduce the transmission of unwanted incident light that enters through the first optical film 20 and reaches the region A11 outside the second optical film 30 through the lid 1. On the other hand, as shown in Figure 2D, light that enters through the first optical film 20 from a field of view angle direction that is wider than that of a straight line can be transmitted through the second optical film 30. Therefore, incident light of a predetermined field of view angle can be transmitted normally.

[0021] <Details of Lid 1 2> As shown in Figure 1A, the plate body 10 may further have a fourth inclined portion 12 located at the edge of the second surface S2, which is inclined in a direction that reduces the thickness of the plate body 10 as it approaches the edge. The "direction of inclination" means a direction that reduces the thickness of the plate body 10 as it approaches the edge, compared to the thickness when there is no inclination (i.e., when the second surface S2 is spread out in a planar shape). The fourth inclined portion 12 may be located around the entire outer circumference of the plate body 10 in a planar view. The fourth inclined portion 12 may have a planar inclined surface.

[0022] With this configuration, the fourth inclined portion 12 reduces the number of fragile parts of the plate body 10 (for example, sharp corners). Therefore, when handling the parts including the lid 1, it is possible to reduce the generation of fine fragments from fragile parts or the generation of fine irregularities on fragile parts. When dealing with ultraviolet light, fine fragments or fine irregularities reflect incident light and tend to add noise to the light transmitted through the lid 1. However, the fourth inclined portion 12 reduces the generation of fine fragments or fine irregularities, thereby reducing noise in the light transmitted through the lid 1.

[0023] Furthermore, the presence of the fourth inclined portion 12 creates a space between the fourth inclined portion 12 and the base 114 of the base 110 when the lid 1 is joined to the package base 110 (see Figure 7). When the bonding material 130 is filled into this space, a gentle meniscus (i.e., curvature) 131 is created in the bonding material 130. The bonding material 130 may be filled until it touches the outer edge of the fourth inclined portion 12, or it may be filled less, only partway up the fourth inclined portion 12. The gentle meniscus 131 of the bonding material 130 in this space allows for adjustment of errors in the amount of bonding material 130 filled, thereby improving the reliability of mounting the lid 1 and the reliability of sealing by the bonding material 130. In addition, when the bonding material 130 touches the fourth inclined portion 12 of the plate body 10, the weak parts of the lid 1 can be protected by the bonding material 130.

[0024] <Details of the Lid 1 3> As shown in Figure 1C, the inclination angle φ1 at the first outer endpoint p1 of the first inclined portion 11 of the plate body 10 may be acute. The inclination angle φ2 at the second outer endpoint p2 of the second inclined portion 21 of the first optical film 20 may be acute. Furthermore, the inclination angle φ3 at the third outer endpoint p3 of the third inclined portion 31 of the second optical film 30 may be acute. This is as shown in the following equations (1) to (3): 15°≦φ1≦60° ... (1) 15°≦φ2≦60° ... (2) 15°≦φ3≦60° ... (3)

[0025] This inclination angle allows light incident on the edge of the plate 10 or the edge of the first optical film 20, as well as light reaching the edge of the second optical film 30, to be reflected further outward in a planar view, thereby reducing the amount of noise that passes through the lid 1.

[0026] The inclination angle φ1 of the first inclined section 11 and the inclination angle φ2 of the second inclined section 21 may be equal, as shown in equation (4). "Equal" includes not only cases where they are exactly equal, but also cases where they are equal within the margin of error. The error in these inclination angles is ±10.0°. φ1 = φ2 ... (4)

[0027] With this configuration, the direction of the critical angle in the first inclined section 11 and the direction of the critical angle in the second inclined section 21 are the same. Therefore, the reflection effect of light incident on the first inclined section 11 and the second inclined section 21 from the same direction is the same. In other words, the difference in reflection effect between the first inclined section 11 and the second inclined section 21 can be reduced. Therefore, when light is incident on the area including the first inclined section 11 and the second inclined section 21, the light can be reflected equally to the outside of the lid 1 regardless of which section the light is incident on. Therefore, the transmission of unwanted light as noise through the lid 1 can be reduced.

[0028] The first inclined portion 11 and the second inclined portion 21 may be continuous. That is, the second endpoint p2 on the outer side in a plan view of the second inclined portion 21 may coincide with the second endpoint p2 on the inner side in a plan view of the first inclined portion 11. With this configuration, irregular reflections and transmissions are less likely to occur even with respect to light incident on the boundary between the first inclined portion 11 and the second inclined portion 21. Therefore, the transmission of unwanted light as noise through the lid 1 can be further reduced.

[0029] According to the above configuration, the first inclined portion 11 of the plate body 10 and the second inclined portion 21 of the first optical film 20 can be formed together by, for example, the following method: grinding using a grinding wheel (e.g., a blade) with an inclination corresponding to the inclination angle φ1 = φ2. According to this formation method, the first optical film 20 can be formed on the entire surface of the first surface S1 of a large plate body for multiple pieces, and then the first inclined portion 11 and the second inclined portion 21 can be formed in the same grinding process when or after individual piece formation. Therefore, the number of manufacturing steps can be reduced. The fourth inclined portion 12 of the plate body 10 can be formed by, for example, grinding using a grinding wheel (e.g., a blade) with an inclination corresponding to the inclination angle of the fourth inclined portion 12. The third inclined portion 31 of the second optical film 30 can be formed by, for example, performing the film formation process in the film formation process using a jig that reduces the amount of film formed at the edges of the second optical film 30 towards the edges. The first inclined section 11, the second inclined section 21, the third inclined section 31, and the fourth inclined section 12 are not limited to being formed by the above construction method.

[0030] (Embodiment 2) Figures 3A to 3C are a cross-sectional view, a plan view, and an enlarged cross-sectional view showing the lid 1A of Embodiment 2 of the present disclosure, respectively. The lid 1A of Embodiment 2 differs in that a third optical film 40 and a fourth optical film 50 are added, and other components may be the same as those of the lid 1 of Embodiment 1.

[0031] The lid 1A of Embodiment 2 may further include a third optical film 40 located on the first optical film 20 and a fourth optical film 50 located on the second optical film 30. "Located on the film" means that it is in contact with the film and located on the outside of the film (i.e., on the upper side if it is the film on the first surface S1 side, and on the lower side if it is the film on the second surface S2 side). The third optical film 40 and the fourth optical film 50 are silicon dioxide (SiO ２ ) It may also be a film. The third optical film 40 and the fourth optical film 50 can be formed using various film formation techniques for forming thin films. According to the lid 1A of Embodiment 2, by having the third optical film 40 and the fourth optical film 50, the reflectance of light transmitted through the lid 1A can be further reduced.

[0032] <Details of Lid 1A 4> As shown in Figure 3A, the third optical film 40 may have a fifth inclined portion 41 at its edge, the surface of which approaches the first surface S1 as it gets closer to the edge of the third optical film 40. The fifth inclined portion 41 may be located around the entire outer circumference of the third optical film 40 in a plan view. The inclined surface of the fifth inclined portion 41 may be planar.

[0033] The fourth optical film 50 may have a sixth inclined portion 51 at its edge, the surface of which approaches the second surface S2 as it gets closer to the edge of the fourth optical film 50. The sixth inclined portion 51 may be located on the entire outer circumference of the fourth optical film 50 in a plan view. The inclined surface of the sixth inclined portion 51 may be a curved surface, or even a convex curved surface.

[0034] As shown in Figure 3B, in a plan view, the fifth inclined portion 41 may be located outward from the sixth inclined portion 51.

[0035] Figures 4A to 4D show the first to fourth examples of incident light or reflected light, respectively. According to the lid 1A of Embodiment 2, as shown in Figure 4A, light incident on the edge of the first optical film 20, the edge of the third optical film 40, or the edge of the plate body 10 is easily reflected outward from the lid 1A by the first inclined portion 11, the second inclined portion 21, and the fifth inclined portion 41. Therefore, it is possible to reduce the amount of light incident on the edges that passes through the lid 1A as noise. Furthermore, as shown in Figure 4B, light reaching the edge of the second optical film 30 or the edge of the fourth optical film 50 is easily reflected outward from the lid 1A (i.e., away from the central axis) by the third inclined portion 31 and the sixth inclined portion 51. Therefore, it is possible to reduce the amount of light reaching the edges that mixes with the light that has been normally transmitted through the lid 1A as noise.

[0036] In addition, the presence of a second inclined portion 21 and a fifth inclined portion 41 at the edges of the first optical film 20 and the third optical film 40 on the first surface S1 side makes it less likely for the layers of the laminated first optical film 20 and the third optical film 40 to delaminate, thereby improving the durability of the lid 1A. Similarly, the presence of a third inclined portion 31 and a sixth inclined portion 51 at the edges of the second optical film 30 and the fourth optical film 50 on the second surface S2 side makes it less likely for the layers of the laminated second optical film 30 and the fourth optical film 50 to delaminate, thereby improving the durability of the lid 1A.

[0037] Furthermore, in a plan view, the fifth inclined portion 41 is positioned outward from the sixth inclined portion 51, so that, as shown in Figure 4C, an area A11 outside the second optical film 30 and the fourth optical film 50 is obtained on the second surface S2 of the plate body 10. This area A11 can then be used as a bonding surface to which the bonding material 130 is attached in order to bond the lid body 1A (see Figure 7). Therefore, as shown in Figure 4C, it is possible to reduce the transmission of unwanted incident light that enters through the first optical film 20 and the third optical film 40 and reaches the area A11 outside the second optical film 30 and the fourth optical film 50 through the lid body 1A. On the other hand, as shown in Figure 4D, light that enters through the first optical film 20 and the third optical film 40 from a field of view angle direction wider than that of a straight line can be transmitted through the second optical film 30 and the fourth optical film 50. Therefore, incident light at a predetermined field of view angle can be transmitted normally.

[0038] <Details of Cover 1A 5> As shown in FIG. 3C, the inclination angle φ5 of the fifth inclined portion 41 and the inclination angle φ6 of the sixth inclined portion 51 may be acute angles as shown in the following formulas (5) and (6). 15°≦φ5≦60° ・・・ (5) 20°≦φ6≦75° ・・・ (6)

[0039] The fifth inclined portion 41 may have a planar inclined surface. The above inclination angle φ5 of the fifth inclined portion 41 may be an inclination angle at an end point p4 on the outer side of the fifth inclined portion 41 in a plan view.

[0040] The above inclination angle φ6 of the sixth inclined portion 51 may be an inclination angle at an end point p5 on the outer side of the sixth inclined portion 51 in a plan view.

[0041] With the inclination angle, light incident on the edge of the third optical film 40 and light reaching the edge of the fourth optical film 50 can be reflected more toward the outside in a plan view, and the transmission of such light as noise through the cover 1A can be further reduced.

[0042] The fifth inclined portion 41 of the third optical film 40 can be formed, for example, by grinding using a grindstone (e.g., a blade) having an inclination corresponding to the inclination angle φ5. The sixth inclined portion 51 of the fourth optical film 50 can be formed, for example, by performing a film formation process via a jig that reduces the film formation amount at the edge of the fourth optical film 50 toward the end in the film formation step. Note that the fifth inclined portion 41 and the sixth inclined portion 51 are not limited to being formed by the above construction methods.

[0043] <Details of Cover 1A 6> As shown in FIG. 3C, the inclination angle φ5 of the fifth inclined portion 41 and the inclination angle φ1 of the first inclined portion 11 may be equal as shown in the following formula (7). The inclination angle φ5 of the fifth inclined portion 41 and the inclination angle φ2 of the second inclined portion 21 may be equal as shown in the following formula (8). The term "equal" includes not only the case of being strictly equal, but also the case of being equal within an error range. The error of the inclination angle is ±10.0°. φ5 = φ1 ・・・ (7) φ5 = φ2 ・・・ (8)

[0044] With this configuration, the direction of the critical angle in the fifth inclined section 41 and the direction of the critical angle in the first inclined section 11 become the same, and the reflection effect of light incident on the first inclined section 11 and the second inclined section 21 from the same direction becomes the same. Similarly, the direction of the critical angle in the fifth inclined section 41 and the direction of the critical angle in the second inclined section 21 become the same, and the reflection effect of light incident on the fifth inclined section 41 and the second inclined section 21 from the same direction becomes the same. In other words, the difference in the reflection effects of the first inclined section 11, the second inclined section 21 and the fifth inclined section 41 can be reduced. Therefore, when light is incident on an area including the first inclined section 11, the second inclined section 21 and the fifth inclined section 41, the light incident on any of the inclined sections can be reflected equally outward from the lid 1A. Therefore, it is possible to reduce the transmission of unwanted light as noise through the lid 1A.

[0045] The fifth inclined portion 41 and the second inclined portion 21 may be continuous. That is, the outer endpoint p4 of the fifth inclined portion 41 in a plan view may coincide with the inner endpoint p4 of the second inclined portion 21 in a plan view. With this configuration, irregular reflections and transmissions are less likely to occur even with respect to light incident on the boundary between the fifth inclined portion 41 and the second inclined portion 21. Therefore, the transmission of unwanted light as noise through the lid 1A can be further reduced.

[0046] According to the above configuration, the first inclined portion 11, the second inclined portion 21, and the fifth inclined portion 41 can be formed together by, for example, the following method: grinding using a grinding wheel (e.g., a blade) with an inclination corresponding to the inclination angles φ1 = φ2 = φ5. According to this forming method, the first optical film 20 and the third optical film 40 are formed on the entire surface of the first surface S1 side of a large plate body for multiple pieces, and then, when or after individual piece formation, the first inclined portion 11, the second inclined portion 21, and the fifth inclined portion 41 can be formed in the same grinding process. Therefore, the manufacturing process can be reduced. Note that the first inclined portion 11, the second inclined portion 21, and the fifth inclined portion 41 are not limited to being formed by the above method.

[0047] <Modified Example of Edge of Plate Body 10> FIGS. 5A to 5D are diagrams each showing Modified Examples 1 to 4 of the edge of the plate body 10. FIGS. 6A to 6C are diagrams each showing Modified Examples 5 to 7 of the edge of the plate body 10.

[0048] The inclination angle φ1 of the first inclined portion 11 may be 45° as shown in FIG. 5A. However, the angle is not limited thereto, and may be within an angle range of 30° to 55°. When the size of the lid body 1A in plan view is small, as shown in FIG. 5B, the inclination angle φ1 may be an angle within a larger range of the above angle range (for example, 50° to 55°, etc.). One or both of the second inclined portion 21 of the first optical film 20 and the fifth inclined portion 41 of the third optical film 40 may have an inclination angle corresponding to the inclination angle φ1 of the first inclined portion 11 described above.

[0049] In Embodiments 1 and 2, the first inclined portion 11 and the fourth inclined portion 12 may have equal sizes (that is, L1x≒L2x, L1y≒L2y) as shown in FIG. 6A. However, as shown in FIG. 6B, the size of the first inclined portion 11 may be larger than the size of the fourth inclined portion 12 (that is, L1x>L2x, L1y>L2y). Alternatively, as shown in FIG. 6C, the size of the first inclined portion 11 may be smaller than the size of the fourth inclined portion 12 (that is, L1x<L2x, L1y<L2y).

[0050] As shown in FIG. 5C, the outer peripheral side surface S3 of the plate body 10 may include a step q1. The step q1 may be located in a height range of 40% to 60% when the height of the first surface S1 is defined as 0% height and the height of the second surface S2 is defined as 100% height.

[0051] As shown in FIG. 5D, in the height range from the first surface S1 to the second surface S2, the proportion occupied by the outer peripheral side surface S3 excluding the ranges of the first inclined portion 11 and the fourth inclined portion 12 may be 30% to 70%. It is represented by the following formula (9). Ly0×30%≦Ly3≦Ly0×70% ...(9)

[0052] (Package for mounting optical elements, optical device, and optical module) Figure 7 is a cross-sectional view showing an optical element mounting package 100, an optical device 200, and an optical module 300 according to an embodiment of the present disclosure. The optical element mounting package 100 of this embodiment may include the lid 1A of Embodiment 2 described above, a base body 110 having a recess 111 including a mounting portion 112 for the optical element 210, and a bonding material 130 for joining the lid 1A and the base body 110. The lid 1A may be replaced with the lid 1 of Embodiment 1. The base body 110 may include a wiring conductor, not shown, extending between the optical element 210 and the outside of the recess 111.

[0053] The optical device 200 of this embodiment may include an optical element mounting package 100 and an optical element 210 mounted on the mounting section 112. The optical element 210 may be a light receiving device such as an image sensor, or a light emitting device.

[0054] The optical module 300 of this embodiment comprises an optical device 200 and a module substrate 310, wherein the optical device 200 may be mounted on the module substrate 310. The module substrate 310 may include wiring conductors, not shown, connected to the optical device 200. Various other electronic elements and various other electrical elements may be mounted on the module substrate 310.

[0055] The recess 111 of the optical element mounting package 100 may be configured to be airtight when the lid 1A is joined to the base 110. The joining material 130 may be resin. The base 110 may have a planar base 114 around the opening of the recess 111, and the lid 1A may be joined to the base 114 via the joining material 130. As described above, the plate body 10 of the lid 1A may have a region A11 on the second surface S2 that is outside the second optical film 30 and the fourth optical film 50. The base 114 may be positioned opposite region A11 of the lid 1A. The joining material 130 may be interposed between region A11 of the lid 1A and the base 114, away from the second optical film 30 and the fourth optical film 50.

[0056] Furthermore, a space is created between the fourth inclined portion 12 of the lid 1A and the base 114 of the base 110, and the bonding material 130 may be filled into this space. A gentle meniscus (i.e., curvature) 131 of the bonding material 130 may be formed on the outer circumference side of this space. As mentioned above, the bonding material 130 may be filled until it contacts the outer circumference end of the fourth inclined portion 12, or it may be filled less, up to partway up the fourth inclined portion 12. The formation of a gentle meniscus 131 of the bonding material 130 in this space allows for adjustment of the amount of bonding material 130 filled, thereby improving the reliability of mounting the lid 1A and the reliability of sealing by the bonding material 130. It also reduces the likelihood of the bonding material 130 bulging outward horizontally from the lid 1A. Furthermore, by the bonding material 130 contacting the fourth inclined portion 12 of the plate 10, the weak parts of the lid 1A can be protected by the bonding material 130.

[0057] The embodiments of this disclosure have been described above. However, the lids, optical element mounting packages, optical devices, and optical modules of this disclosure are not limited to the lids 1, 1A, optical element mounting package 100, optical device 200, and optical module 300 of the above embodiments. For example, the details shown in the embodiments can be modified as appropriate without departing from the spirit of the invention.

[0058] An embodiment of the present disclosure is shown below. In one embodiment, (1) the lid comprises a transparent plate having a first surface and a second surface located opposite to the first surface, a first optical film located on the first surface, a second optical film located on the second surface, a first inclined portion located on the edge of the first surface and inclined in a direction that reduces the thickness of the plate as it approaches the edge of the plate, a second inclined portion located on the edge of the first optical film and inclined in a direction that reduces the thickness of the first optical film as it approaches the edge of the first optical film, and a third inclined portion located on the edge of the second optical film and inclined in a direction that reduces the thickness of the second optical film as it approaches the edge of the second optical film, wherein in a plan view, the second inclined portion is located outward from the third inclined portion.

[0059] (2) The cover of (1) above has an inclination angle of 15° to 60° at the first outer endpoint of the first inclined portion in a plan view, an inclination angle of 15° to 60° at the second outer endpoint of the second inclined portion in a plan view, and an inclination angle of 15° to 60° at the third outer endpoint of the third inclined portion in a plan view.

[0060] (3) The cover of (1) or (2) above has an inclination angle equal to the inclination angle of the first inclined portion and the inclination angle of the second inclined portion.

[0061] (4) Any one of the lids described in (1) to (3) above further comprises a fourth inclined portion located on the edge of the second surface, which is inclined in a direction that reduces the thickness of the plate as it approaches the edge of the plate.

[0062] (5) Any one of the covers described in (1) to (4) above comprises: a third optical film located on the first optical film; a fourth optical film located on the second optical film; a fifth inclined portion located at the edge of the third optical film, the surface of which approaches the first surface as it gets closer to the edge; and a sixth inclined portion located at the edge of the fourth optical film, the surface of which approaches the second surface as it gets closer to the edge, wherein in a plan view, the fifth inclined portion is located outward from the sixth inclined portion.

[0063] (6) The lid of (5) above has an inclination angle of 15° to 60° for the fifth inclined portion and an inclination angle of 20° to 75° for the sixth inclined portion.

[0064] (7) The cover of (5) or (6) above has an inclination angle equal to the inclination angle of the first inclined portion and the inclination angle of the fifth inclined portion.

[0065] In one embodiment, (8) the optical element mounting package comprises one of the lids described in (1) to (7) above, a base having a recess including a mounting portion for an optical element, and a bonding material for joining the lid and the base.

[0066] In one embodiment, (9) the optical device comprises the optical element mounting package described in (8) above, and the optical element mounted on the mounting portion.

[0067] In one embodiment, (10) the optical module comprises the optical device described in (9) above, and a module substrate on which the optical device is mounted.

[0068] This disclosure relates to a cover, a package for mounting optical elements, an optical device, and an optical module.

[0069] 1, 1A Lid body 10 Plate body S1 First surface S2 Second surface A11 Area S3 Outer peripheral side surface q1 Step 11 First inclined part 12 Fourth inclined part 20 First optical film 21 Second inclined part 30 Second optical film 31 Third inclined part 40 Third optical film 41 Fifth inclined part 50 Fourth optical film 51 Sixth inclined part φ1, φ2, φ3, φ5, φ6 Inclination angle p1 First end point p2 Second end point p3 Third end point p4, p5 End point 100 Optical element mounting package 110 Base 111 Recessed part 112 Mounting part 114 Pedestal 130 Bonding material 131 Meniscus 200 Optical device 300 Optical module

Claims

1. A lid comprising: a transparent plate having a first surface and a second surface located opposite to the first surface; a first optical film located on the first surface; a second optical film located on the second surface; a first inclined portion located on the edge of the first surface, which is inclined in a direction that reduces the thickness of the plate as it approaches the edge of the plate; a second inclined portion located on the edge of the first optical film, which is inclined in a direction that reduces the thickness of the first optical film as it approaches the edge of the first optical film; and a third inclined portion located on the edge of the second optical film, which is inclined in a direction that reduces the thickness of the second optical film as it approaches the edge of the second optical film, wherein in a plan view, the second inclined portion is located outward from the third inclined portion.

2. The lid according to claim 1, wherein the inclination angle at the first outer endpoint of the first inclined portion in a plan view is 15° to 60°, the inclination angle at the second outer endpoint of the second inclined portion in a plan view is 15° to 60°, and the inclination angle at the third outer endpoint of the third inclined portion in a plan view is 15° to 60°.

3. The lid according to claim 1 or claim 2, wherein the inclination angle of the first inclined portion is equal to the inclination angle of the second inclined portion.

4. The lid according to any one of claims 1 to 3, further comprising a fourth inclined portion located on the edge of the second surface, which is inclined in a direction that reduces the thickness of the plate as it approaches the edge of the plate.

5. A lid according to any one of claims 1 to 4, comprising: a third optical film located on the first optical film; a fourth optical film located on the second optical film; a fifth inclined portion located at the edge of the third optical film, the surface of which approaches the first surface as it gets closer to the edge; and a sixth inclined portion located at the edge of the fourth optical film, the surface of which approaches the second surface as it gets closer to the edge, wherein in a plan view, the fifth inclined portion is located outward from the sixth inclined portion.

6. The lid according to claim 5, wherein the inclination angle of the fifth inclined portion is 15° to 60°, and the inclination angle of the sixth inclined portion is 20° to 75°.

7. The lid according to claim 5 or claim 6, wherein the inclination angle of the first inclined portion is equal to the inclination angle of the fifth inclined portion.

8. An optical element mounting package comprising: a lid according to any one of claims 1 to 7; a substrate having a recess including a mounting portion for an optical element; and a bonding material for joining the lid and the substrate.

9. An optical device comprising: an optical element mounting package according to claim 8; and an optical element mounted on the mounting portion.

10. An optical module comprising: an optical device according to claim 9; and a module substrate on which the optical device is mounted.

Images