Light-shielding film, optical components, lids, electronic component mounting packages, and imaging devices

Abstract

Provided is a light-shielding film having a first surface and a second surface located opposite the first surface. The light-shielding film comprises a resin, carbon black, and a type 1 graphite filler, and in a longitudinal cross-section, the longitudinal direction of the type 1 graphite filler extends along at least one surface from among the first surface and the second surface.

Description

【Technical Field】 【0001】 The present disclosure relates to a light-shielding film, an optical component, a lid body, an electronic component mounting package, and an imaging device. parts 【Background Art】 【0002】 Japanese Patent Application Laid-Open No. 2007-115921 discloses a light-shielding film containing carbon black and a solid-state imaging device having the light-shielding film. 【Summary of the Invention】 【Means for Solving the Problems】 【0003】 The light-shielding film according to the present disclosure is a light-shielding film having a first surface and a second surface located opposite to the first surface, containing a resin, carbon black, and a first type of graphite filler, Type 2 graphite filler, Type 3 graphite filler, in a longitudinal section, the longitudinal direction of the first type of graphite filler is along at least one of the first surface and the second surface Occasionally, In the longitudinal section, the longitudinal direction of the second type of graphite filler is aligned with the thickness direction of the light-shielding film. In the longitudinal section, the longitudinal direction of the third type of graphite filler is inclined midway between the thickness direction of the light-shielding film and the direction along one of the surfaces. When the layer from the first surface that is 1 / 4 of the thickness of the light-shielding film is called the first layer, the layer from the second surface that is 1 / 4 of the thickness of the light-shielding film is called the third layer, and the layer between the first layer and the third layer is called the second layer, In the first layer, the amount of the first type graphite filler is greater than the sum of the second type graphite filler and the third type graphite filler. In the third layer, the amount of the first type graphite filler is greater than the sum of the second type graphite filler and the third type graphite filler. In the second layer, the sum of the second type graphite filler and the third type graphite filler is greater than the first type graphite filler. 【0004】 The optical component according to the present disclosure is an optical member having a third surface, and the above light-shielding film located on the third surface. 【0005】 The lid body according to the present disclosure is a base having a fourth surface, and the above light-shielding film located on the fourth surface. 【0006】 The package for mounting electronic components according to the present disclosure is a mounting portion for mounting an electronic component, an opening through which light passes, the above-described light-shielding film, and includes. 【0007】 The imaging device according to the present disclosure is the above-described package for mounting electronic components, an imaging element mounted on the package for mounting electronic components, and includes. 【Brief Description of the Drawings】 【0008】 [Figure 1A] It is a plan view showing an optical component according to Embodiment 1 of the present disclosure. [Figure 1B] It is a cross-sectional view taken along line B1-B1 of FIG. 1A. [Figure 2] It is a view showing a longitudinal cross-section of a light-shielding film according to an embodiment of the present disclosure. [Figure 3] It is a view for explaining the first action of the graphite filler. [Figure 4] It is a view for explaining the second action of the graphite filler. [Figure 5] It is a view for explaining the third action of the graphite filler. [Figure 6] It is a view for explaining the fourth action of the graphite filler. [Figure 7] It is a graph showing the relationship between the content rate of the graphite filler and the reflectance of the light-shielding film. [Figure 8] It is a view showing the distribution of the first to third types of graphite fillers in the longitudinal cross-section of the light-shielding film. [Figure 9] It is a graph showing the transmittance of the light-shielding film according to the embodiment. [Figure 10] It is a graph showing the reflectance of the light-shielding film according to the embodiment. [Figure 11] It is a perspective view showing a graphite filler. [Figure 12A] It is a plan view showing an optical component according to Embodiment 2 of the present disclosure. [Figure 12B] It is a longitudinal sectional view taken along line B2 - B2 of FIG. 12A. [Figure 13A] It is an exploded perspective view showing a package for mounting electronic components and an imaging device according to an embodiment of the present disclosure. [Figure 13B] It is a sectional view showing a package for mounting electronic components and an imaging device according to an embodiment of the present disclosure. 【Embodiments for Carrying out the Invention】 【0009】 Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. FIG. 1A is a plan view showing an optical component according to Embodiment 1 of the present disclosure. FIG. 1B is a sectional view taken along line B1 - B1 of FIG. 1A. 【0010】 The light - shielding film 1 according to the embodiment of the present disclosure has a first surface S1 irradiated with light and a second surface S2 located opposite to the first surface S1, and is a film that reduces the amount of light transmitted and reflected. In FIGS. 1A and 1B, the light - shielding film 1 is shown with shading. 【0011】 The optical component 10 according to Embodiment 1 of the present disclosure includes an optical member 11 having a third surface S3 and the light - shielding film 1. The optical member 11 may be plate - shaped as shown in FIGS. 1A and 1B, or may be in a prism shape or a lens shape. The optical member 11 is a translucent member (such as glass), and a part of the third surface S3 may be a surface through which light passes. Alternatively, the optical member 11 may be an optical filter member that exerts an action according to the wavelength, polarization plane, incident angle, etc. of light. Or, the optical member 11 may be a mirror that reflects light at a part of the third surface S3. 【0012】 The light - shielding film 1 is located on the third surface S3 of the optical member 11. The light - shielding film 1 may be fixed to the third surface S3 of the optical member 11. As shown in FIG. 1A, the light - shielding film 1 may be located around the light - transmitting region R1 that transmits light, or may be located at various sites where light shielding is required. 【0013】 Figure 2 shows a longitudinal cross-section of a light-shielding film according to an embodiment of the present disclosure. In Figures 2 to 6, the irradiated light is indicated by a dashed-dotted arrow. The longitudinal cross-section of the light-shielding film 1 refers to the cross-section obtained when the film is cut along the thickness direction (the direction perpendicular to the film surface). The light-shielding film 1 contains a resin Ha, carbon black Hb, and a plurality of graphite fillers F. In Figure 2, to avoid complexity, only a few of the plurality of graphite fillers F are labeled with reference numerals. 【0014】 The resin Ha may be a thermosetting resin or an epoxy resin. This configuration makes it possible to keep outgassing (gas generated by heating after curing) to a minimum. 【0015】 Carbon black Hb may be mixed with resin Ha so as to be uniformly distributed within the resin Ha. Carbon black Hb mixed with resin Ha has the properties of reducing light transmission, reducing light reflection, and absorbing light over a wide wavelength range. 【0016】 The graphite filler F may be in the form of flakes. In the longitudinal cross-section of the light-shielding film 1, the graphite filler F often has a shape that is longer on one side. The graphite filler F has the properties of reducing the amount of light transmitted, reducing the amount of light reflected, and absorbing light over a wide wavelength range. 【0017】 Carbon black Hb mixed with resin Ha has a higher light absorption rate than graphite filler F. When the thickness of resin Ha containing carbon black Hb is the same as that of graphite filler F, graphite filler F has a lower light transmittance than the carbon black Hb mentioned above. 【0018】 <Arrangement structure of graphite filler in longitudinal section> Figures 3 to 6 illustrate the arrangement and function of graphite fillers. 【0019】 The light-shielding film 1 may contain a type 1 graphite filler F1 whose longitudinal direction is aligned with at least one of the first surface S1 and the second surface S2 (hereinafter referred to as "one film surface") in a longitudinal cross-section (see Figures 3 to 6). Here, the graphite filler F with this orientation is called "type 1 graphite filler F1". "Longer direction aligned with one film surface" means that the longitudinal direction is parallel to one film surface at an angle of ±30°. Furthermore, the longitudinal direction of the graphite filler F means the straight line direction connecting one end and the other end in the longitudinal direction. 【0020】 By including the first type graphite filler F1 in the light-shielding film 1, the light incident in the thickness direction of the light-shielding film 1 is received over a wide surface area of ​​the first type graphite filler F1, thereby efficiently reducing the light transmittance of the light-shielding film 1. In other words, by including the first type graphite filler F1, the light transmittance of the light-shielding film 1 can be reduced with a small amount of graphite filler F. 【0021】 The first type graphite filler F1 may be located in the third layer L3, which is closer to the second surface S2 than to the central surface S0 between the first surface S1 and the second surface S2 of the light-shielding film 1 (see Figures 3 to 6). With this configuration, light entering the light-shielding film 1 from the first surface S1 is absorbed by the carbon black Hb mixed in the resin Ha. Furthermore, even if the entering light reaches the third layer L3, it is blocked by the wide surface of the first type graphite filler F1 in the third layer L3, significantly reducing the amount of light that passes through the light-shielding film 1. Therefore, the transmittance of the light-shielding film 1 can be reduced. In addition, although not shown in the figures, the first type graphite filler F1 has numerous irregularities on its surface. Therefore, by positioning the first type graphite filler F1 in the third layer L3, the irregular shape of the surface of the first type graphite filler F1 appears on the second surface S2 of the light-shielding film 1, making the second surface S2 a rough surface. Furthermore, the surface roughness can reduce surface reflection on the second surface S2. Therefore, even if some of the light transmitted through the optical component 10 becomes stray light and returns to the second surface S2 of the light-shielding film 1, the reflection of that light can be reduced, thereby reducing stray light. 【0022】 The first type graphite filler F1 may also be located in the first layer L1, which is closer to the first surface S1 than the central surface S0 between the first surface S1 and the second surface S2 of the light-shielding film 1 (see Figures 4 to 6). By being located in the first layer L1, the light transmittance in the vicinity of the first surface S1 can be significantly reduced, and the thickness of the light-shielding film 1 required to reduce the transmittance to a predetermined value or less can be reduced. Furthermore, the first type graphite filler F1 located in the first layer L1 can make the first surface S1 of the light-shielding film 1 a rough surface, thereby reducing the reflectance of the first surface S1. Therefore, the transmittance and reflectance of the light-shielding film 1 can be reduced. 【0023】 The first type graphite filler F1 located in the first layer L1 and the first type graphite filler F1 located in the third layer L3 may have surfaces facing each other along their longitudinal direction (see Figures 4 to 6). In Figures 4 to 6, surfaces S11 and S12 face each other, and surfaces S13 and S14 face each other. With this configuration where the surfaces face each other, even if light penetrates from the first surface S1 beyond the first type graphite filler F1 of the first layer L1 into the interior, much of this light is blocked by the first type graphite filler F1 of the third layer L3. Therefore, the amount of light that passes through the light-shielding film 1 can be reduced. Furthermore, light confined between the first type graphite filler F1 of the first layer L1 and the first type graphite filler F1 of the third layer L3 (see light ray Lr1) is absorbed by the carbon black Hb between them. Therefore, the transmittance and reflectance of the light-shielding film 1 can be further reduced. 【0024】 The light-shielding film 1 may include a type 2 graphite filler F2 whose longitudinal direction is aligned with the thickness direction of the light-shielding film 1 in a longitudinal cross-section (see Figures 5 and 6). Here, the graphite filler F with this orientation is called "type 2 graphite filler F2". The above statement that the longitudinal direction is aligned with the thickness direction means that the longitudinal direction is parallel to the thickness direction within ±30°. By including the type 2 graphite filler F2, light that has penetrated into the interior of the light-shielding film 1 beyond the type 1 graphite filler F1 of the first layer L1 is also blocked from the lateral direction by the type 2 graphite filler F2. Therefore, it is possible to reduce the leakage of such light from any point in the light-shielding film 1 to the outside of the film. 【0025】 Multiple Type 2 graphite fillers F2 may be positioned so that their longitudinal surfaces face each other (see Figures 5 and 6). In Figures 5 and 6, surfaces S21 and S22 face each other. With this configuration where the surfaces face each other, light that penetrates beyond the Type 1 graphite filler F1 of the first layer L1 into the interior of the light-shielding film 1 can be trapped between the multiple Type 2 graphite fillers F2 from the side. This light is then absorbed by the carbon black Hb between them, reducing leakage to the outside of the film. Therefore, the transmittance and reflectance of the light-shielding film 1 can be further reduced. 【0026】 The light-shielding film 1 may further include a type 3 graphite filler F3 whose longitudinal direction is inclined midway between the thickness direction of the light-shielding film 1 and the direction along the surface of the film in a longitudinal section (see Figure 6). Here, the graphite filler F in this orientation is called "type 3 graphite filler F3". The inclination of the longitudinal direction midway means that the longitudinal direction is greater than 30° and less than 60° with respect to the thickness direction of the light-shielding film 1. 【0027】 Because the light-shielding film 1 contains a type 3 graphite filler F3, light that enters the interior of the light-shielding film 1 is reflected by the type 3 graphite filler F3 and easily propagates along the film surface, and is easily absorbed by carbon black Hb during this propagation (see light ray Lr2). Therefore, the transmittance and reflectance of the light-shielding film 1 can be further reduced. 【0028】 The light-shielding film 1 may contain multiple graphite fillers F in a longitudinal cross-section so as to surround the carbon black Hb and resin Ha (see Figures 5 and 6). The graphite fillers F surrounding the carbon black Hb and resin Ha may be at least two (two types) of graphite fillers F from among type 1 graphite filler F1, type 2 graphite filler F2, and type 3 graphite filler F3. In Figure 5, the region R10 of resin Ha is surrounded by multiple graphite fillers F each having surfaces S21, S11, S13, S22, S14, and S12. In Figure 6, the region R11 of resin Ha is surrounded by multiple graphite fillers F each having surfaces S11, S21, S12, and S31. Similarly, the region R12 of resin Ha is surrounded by multiple graphite fillers F each having surfaces S13, S22, S14, and S32. According to this configuration, light entering regions R10, R11, and R12 surrounded by multiple graphite fillers F is confined within these regions and readily absorbed by carbon black Hb in these regions. Therefore, the transmittance and reflectance of the light-shielding film 1 can be further reduced. 【0029】 <Detailed example of light-shielding film 1> In the longitudinal cross-section of the light-shielding film 1, the graphite filler F may be present in an area ratio of 32% to 48%, preferably 36% to 44%, and more preferably 38% to 42%. An area ratio of 32% or more for graphite filler F sufficiently reduces the transmittance of the light-shielding film 1 by reducing the amount of light transmitted by the graphite filler F. Furthermore, a concentration of 32% or more provides sufficient surface roughening, thereby reducing surface reflection of the light-shielding film 1. An area ratio of 36% or more, or 38% or more for graphite filler F, further enhances the above-mentioned transmittance reduction and surface reflection reduction effects. 【0030】 Figure 7 is a graph showing the relationship between the graphite filler content and the reflectance of the light-shielding film. This graph shows the results of testing the reflectance in the ultraviolet and visible light wavelength ranges for multiple light-shielding films 1 with varying graphite filler content, while keeping the film thickness constant at "20 μm". As shown in the graph of Figure 7, the reflectance of the light-shielding film 1 is kept low when the area ratio of graphite filler F is 32% or more. 【0031】 On the other hand, when the area ratio of graphite filler F is 48% or less, appropriate fluidity is obtained in the uncured resin Ha containing graphite filler F, improving the workability for printing the light-shielding film 1. When the area ratio of graphite filler F is 44% or less, or 42% or less, the above workability is further improved. 【0032】 The ratio of the area of ​​graphite filler F to the mass of graphite filler F is approximately 1.6. 【0033】 The thickness of the light-shielding film 1 may be 10 μm to 25 μm, preferably 12 μm to 20 μm, and more preferably 14 μm to 18 μm. If the fluidity of the resin Ha having the above-mentioned graphite filler F content ratio is sufficient, the light-shielding film 1 having the above-mentioned thickness can be produced with a small number of printing passes (for example, one pass) and with minimal printing inconsistencies. Furthermore, a light-shielding film 1 having the above-mentioned thickness can achieve a sufficiently low light transmittance. 【0034】 More specifically, in terms of area ratio in the longitudinal section, the first type graphite filler F1 (graphite filler F whose longitudinal direction is aligned with one film surface) may be present in an amount of 16% to 25%, preferably 18% to 23%, and more preferably 19% to 22%. 【0035】 Furthermore, in terms of area ratio in the longitudinal section, the second type graphite filler F2 (graphite filler F whose longitudinal direction is aligned with the thickness direction of the film) may be present in an amount of 7.5% to 11.5%, preferably 8.5% to 10.5%, and more preferably 9.0% to 10.0%. 【0036】 Furthermore, in terms of area ratio in the longitudinal section, the third type graphite filler F3 (graphite filler F whose longitudinal direction is aligned with the intermediate inclined direction) may be present in an amount of 7.5% to 11.5%, preferably 8.5% to 10.5%, and more preferably 9.0% to 10.0%. 【0037】 Furthermore, in terms of area ratio in the longitudinal section, the total amount of Type 2 graphite filler F2 and Type 3 graphite filler F3 may be 15% to 23%, preferably 17% to 21%, and more preferably 18% to 20%. 【0038】 This blending ratio allows the effects of graphite filler F, as explained with reference to Figures 3 to 6, to be more pronounced. 【0039】 <Detailed example of light-shielding film 2> Figure 8 shows the distribution of Type 1 to Type 3 graphite fillers in the longitudinal section of the light-shielding film. In this figure, Type 1 graphite filler F1 is shown in white, and Type 2 and Type 3 graphite fillers F2 and F3 are shown in shaded areas. Type 1 graphite filler F1 is a graphite filler F whose longitudinal direction is aligned with one film surface (longitudinal direction is parallel to one film surface within ±30°). Type 2 graphite filler F2 is a graphite filler F whose longitudinal direction is aligned with the thickness direction of the film (0° or more and less than 30° relative to the thickness direction). Type 3 graphite filler F3 is a graphite filler F whose longitudinal direction is sloped midway between the thickness direction of the light-shielding film 1 and the direction aligned with one film surface. 【0040】 In terms of area ratio in the longitudinal section, the distribution ratio of Type 1 graphite filler F1 and Type 2 and Type 3 graphite fillers F2 and F3 in each layer (L1 to L3) of the light-shielding film 1 may have the following relationship: That is, in the first layer L1, the amount of Type 1 graphite filler F1 may be greater than the sum of the Type 2 and Type 3 graphite fillers F2 and F3. In the third layer L3, the amount of Type 1 graphite filler F1 may be greater than the sum of the Type 2 and Type 3 graphite fillers F2 and F3. In the second layer L2, the sum of Type 2 and Type 3 graphite fillers F2 and F3 may be greater than the amount of Type 1 graphite filler F1. 【0041】 The first layer L1 is a layer that is 1 / 4 of the thickness of the light-shielding film 1 from the film surface on the light-incident side, the third layer L3 is a layer that is 1 / 4 of the thickness of the light-shielding film 1 from the film surface on the light-emitting side, and the second layer L2 corresponds to the layer between the first layer L1 and the third layer L3. 【0042】 With this configuration, in the visible light range, the first type graphite filler F1 of the first layer L1 blocks the entry of light over a wide area, making it possible to sufficiently reduce the light transmittance. Furthermore, the first type graphite filler F1 of the third layer L3 creates irregularities on the second surface S2, making the second surface S2 a rough surface, thereby reducing the reflectance of the film surface. If the first surface S1 does not adhere closely to a component (optical component 11, etc.), the surface of the first surface S1 can also be made rough, further reducing the reflectance of the film surface. 【0043】 Furthermore, in the near-infrared and short-wavelength infrared regions, a certain percentage of light passes through the first type graphite filler F1 of the first layer L1 due to diffraction and other factors. However, this light is confined in regions surrounded by multiple graphite fillers F in the second layer L2 and the third layer L3, and absorbed by the carbon black Hb contained in these regions. Through this action, the transmittance and reflectance of the light-shielding film 1 can be sufficiently reduced even in the near-infrared and short-wavelength infrared regions. 【0044】 The thickness of the light-shielding film 1 may be at least twice the average maximum longitudinal dimension of the graphite filler F in the longitudinal section. The average maximum longitudinal dimension of the graphite filler F refers to the average of the top 90% to 98% of the longitudinal dimensions of each graphite filler F in any region of the longitudinal section containing a large number of graphite fillers F. If the average maximum longitudinal dimension of the graphite filler F is 4 μm to 6 μm, the above condition is satisfied with a film thickness of 10 μm to 25 μm. 【0045】 By using the above film thickness, it is easier to ensure that the longitudinal direction of the graphite filler F in the second layer L2 is less than ±60° from the film thickness direction. Therefore, it is easier to use more of the second and third type graphite fillers F2 and F3 than the first type graphite filler F1 in the second layer L2. 【0046】 <Optical properties of light-shielding films> Figure 9 is a graph showing the transmittance of the light-shielding film according to the embodiment. Figure 10 is a graph showing the reflectance of the light-shielding film according to the embodiment. These two graphs show the characteristics of the light-shielding film 1 with a thickness of 20 μm. 【0047】 As shown in Figure 9, the light-shielding film 1 may have a light transmittance of less than 0.2% in the ultraviolet region to the short-wavelength infrared region (250 nm to 2500 nm). Furthermore, as shown in Figure 10, the light-shielding film 1 may have a light reflectance of less than 0.5% in the ultraviolet region to the short-wavelength infrared region (250 nm to 2500 nm). 【0048】 Having such transmittance and reflectivity, the light-shielding film 1 can sufficiently block unwanted light when used with various optical elements. Here, for example, consider a case where the optical element is an image sensor, the light-shielding film 1 is positioned in front of the image sensor so as to surround the incident range of light, and the image sensor has sensitivity beyond the visible light wavelength range to the ultraviolet or infrared region. Even in such a case, the light-shielding film 1 having the above-mentioned transmittance and reflectivity characteristics can reduce the effect of flare or ghosting on the signal from the image sensor. 【0049】 <Explanation of the arrangement and function of graphite fillers when viewed in three dimensions> Next, the arrangement and function of the graphite filler F when viewed three-dimensionally within the light-shielding film 1 will be explained. Figure 11 is a perspective view of the graphite filler. The graphite filler F may be in the form of flakes (disk-shaped including distortion and irregularities), as shown in Figure 11. Each graphite filler F can be associated with the flat disk D1 that has the closest shape. For example, the least squares method may be used to make the above association. Hereinafter, the central axis A1 and surface Sd1 of the flat disk D1 will be referred to as the central axis A1 and surface Sd1 of the graphite filler F. 【0050】 The light-shielding film 1 may include a graphite filler F whose surface Sd1 is aligned with at least one of the first surface S1 and second surface S2 (hereinafter referred to as "one film surface") (see Figures 3 to 6). Although the definition of the graphite filler F in this orientation differs from that of the aforementioned first-type graphite filler F1, it is almost equivalent to the aforementioned first-type graphite filler F1, and therefore will also be referred to as first-type graphite filler F1 here. The statement that the surface Sd1 is aligned with one film surface means that the acute angle between the central axis A1 of the graphite filler F and the normal to the surface is 30° or less. By including first-type graphite filler F1, light incident in the thickness direction of the light-shielding film 1 can be received by a wide surface of the first-type graphite filler F1, and the light transmittance of the light-shielding film 1 can be efficiently reduced. In other words, the inclusion of Type 1 graphite filler F1 allows for a reduction in the light transmittance of the light-shielding film 1 with a smaller amount of graphite filler F. 【0051】 The first type graphite filler F1 may be located in the third layer L3 of the light-shielding film 1 (see Figures 3 to 6). By being located in the third layer L3, even if light that enters the interior of the light-shielding film 1 proceeds without being absorbed by the carbon black Hb, the first type graphite filler F1 blocks the light near the second surface S2, reducing the amount of light that passes through the light-shielding film 1. Furthermore, since the first type graphite filler F1 has numerous irregularities on its surface, the irregular shape of the surface of the first type graphite filler F1 located in the third layer L3 appears on the second surface S2, making the second surface S2 a rough surface. As a result, the surface reflection of the second surface S2 is reduced by the roughness of the surface, and the reflectivity of the light-shielding film 1 can be lowered. 【0052】 The first type graphite filler F1 may also be located in the first layer L1 of the light-shielding film 1 (see Figures 4 to 6). The first type graphite filler F1 located in the first layer L1 blocks light from entering over a wide area near the first surface S1, thereby reducing the transmittance of the light-shielding film 1. In addition, the unevenness of the first type graphite filler F1 located in the first layer L1 can make the first surface S1 of the light-shielding film 1 rough when it is not in close contact with a material, thereby reducing surface reflection on the first surface S1. Therefore, the transmittance and reflectance of the light-shielding film 1 can be reduced. 【0053】 The first type graphite filler F1 located in the first layer L1 and the first type graphite filler F1 located in the third layer L3 may have their respective surface Sd1s facing each other (see Figures 4 to 6). That is, when viewed perpendicularly to the surface of the light-shielding film 1, the first type graphite filler F1 of the first layer L1 and the first type graphite filler F1 of the third layer L3 may be positioned to overlap. In Figure 4, the above surface Sd1 corresponds to surfaces S11 to S14. In Figures 5 and 6, the above surface Sd1 corresponds to surfaces S11 to S14. 【0054】 With this configuration, even if light incident from the first surface S1 penetrates beyond the first type graphite filler F1 of the first layer L1 into the interior, much of this light is blocked by the first type graphite filler F1 of the third layer L3, reducing the amount of light that passes through the light-shielding film 1. Furthermore, light confined between the first type graphite filler F1 of the first layer L1 and the first type graphite filler F1 of the third layer L3 is absorbed by the carbon black Hb confined between them. Therefore, the transmittance and reflectance of the light-shielding film 1 can be further reduced. 【0055】 The light-shielding film 1 may include graphite filler F whose surface Sd1 is aligned with the thickness direction of the light-shielding film 1 (see Figures 5 and 6). Although the definition of graphite filler F in this orientation differs from that of the aforementioned type 2 graphite filler F2, it is almost equivalent to the aforementioned type 2 graphite filler F2, and therefore will be referred to as type 2 graphite filler F2 here as well. The statement that the surface Sd1 is aligned with the thickness direction of the light-shielding film 1 means that the acute angle between the central axis A1 of the graphite filler F and the normal to the surface of the light-shielding film 1 is between 60° and 90°. By including type 2 graphite filler F2, light that has penetrated into the interior of the light-shielding film 1 beyond the type 1 graphite filler F1 of the first layer L1 is also blocked by the type 2 graphite filler F2 from the direction along the film surface. Therefore, leakage of such light from any point in the light-shielding film 1 to the outside of the film is reduced. 【0056】 Multiple Type II graphite fillers F2 may be positioned so that their surfaces Sd1 face each other (see Figures 5 and 6). Opposition means that when viewed through the direction of the central axis A1 of one Type II graphite filler F2, the surface Sd1 of one Type II graphite filler F2 overlaps with the surface Sd1 of another Type II graphite filler F2. Furthermore, opposition may also mean that the acute angle between the central axis A1 of one Type II graphite filler F2 and the central axis A1 of the other Type II graphite filler F2 is 45° or less, and the central axis A1 of one Type II graphite filler F2 intersects the surface Sd1 of the other Type II graphite filler F2. In Figures 5 and 6, the surfaces Sd1 of the opposing Type II graphite fillers F2 correspond to surfaces S21 and S22. 【0057】 In this configuration, where the surfaces Sd1 of the Type 2 graphite filler F2 face each other, light that penetrates beyond the Type 1 graphite filler F1 of the first layer L1 into the interior of the light-shielding film 1 is sandwiched between multiple Type 2 graphite fillers F2 from the side. Therefore, the light can be trapped between them. The trapped light is then absorbed by the carbon black Hb between them, reducing leakage to the outside of the film. Thus, the transmittance and reflectance of the light-shielding film 1 can be further reduced. 【0058】 The light-shielding film 1 may further include a graphite filler F whose surface Sd1 is tilted midway between the thickness direction of the light-shielding film 1 and the direction along one of the film surfaces (see Figure 6). Although the definition of the graphite filler F in this orientation differs from that of the aforementioned third-type graphite filler F3, it is almost equivalent to the aforementioned third-type graphite filler F3, and therefore will be referred to as third-type graphite filler F3 here as well. The fact that the surface Sd1 is tilted midway means that the acute angle between the central axis A1 of the graphite filler F and the normal to the film surface of the light-shielding film 1 is between 30° and 60°. By including the third-type graphite filler F3 in the light-shielding film 1, light that enters the interior of the light-shielding film 1 is reflected by the third-type graphite filler F3, making it easier to propagate in the direction along the film surface, and is easily absorbed by carbon black Hb during this propagation. Therefore, the transmittance and reflectance of the light-shielding film 1 can be further reduced. 【0059】 The light-shielding film 1 may include a plurality of graphite fillers F surrounding the carbon black Hb and resin Ha from the thickness direction of the film and from the direction along the film surface (see Figures 5 and 6). The plurality of graphite fillers F surrounding from the direction along the film surface may be configured to surround the carbon black Hb and resin Ha from three or more directions along the film surface. The graphite fillers F surrounding the carbon black Hb and resin Ha may be at least two (two types) of graphite fillers F from Type 1 graphite filler F1, Type 2 graphite filler F2, and Type 3 graphite filler F3. With this configuration, light entering regions R10, R11, and R12 surrounded by the plurality of graphite fillers F is confined within those regions and is easily absorbed by the carbon black Hb in those regions. Therefore, the transmittance and reflectance of the light-shielding film 1 can be further reduced. 【0060】 <Optical Components> Figure 12A is a plan view showing an optical component of Embodiment 2 of the present disclosure. Figure 12B is a longitudinal cross-sectional view taken along the line B2-B2 in Figure 12A. 【0061】 The optical component 10A of Embodiment 2 comprises an optical member 11 having a third surface S3 and a light-shielding film 1. The optical member 11 may be plate-shaped as shown in Figures 12A and 12B. The optical member 11 is a light-transmitting material (such as glass), and a light-transmitting region R1 that allows light to pass through may be included in a part of the third surface S3. 【0062】 The light-shielding film 1 is located on the third surface S3 of the optical member 11. The light-shielding film 1 may be fixed to the third surface S3 of the optical member 11. As shown in Figure 12A, the light-shielding film 1 may be located around the light-transmitting region R1 that transmits light, extending to the edge of the third surface S3. The light-shielding film 1 has the structure and characteristics described above. 【0063】 Furthermore, the light-shielding film 1 may include a region R11 that is thicker than other parts, as shown in Figure 12B. The thick region R11 may be shaped along a closed path surrounding the light-transmitting region R1. The thick region R11 may function as a bonding material and bond to the periphery of the package opening before curing, so that the optical component 10A seals the opening. 【0064】 With the optical component 10A configured as described above, the process of adding a sealing bonding material can be integrated into the process of adding the light-shielding film 1, thereby reducing the number of steps involved in manufacturing the optical component 10A and lowering the manufacturing cost of the optical component 10. 【0065】 <Packages for mounting electronic components and imaging devices> Figure 13A is an exploded perspective view showing an electronic component mounting package and imaging device according to an embodiment of the present disclosure. Figure 13B is a cross-sectional view showing an electronic component mounting package and imaging device according to an embodiment of the present disclosure. 【0066】 The electronic component mounting package 100 of this embodiment comprises a base body 101 having a mounting section 102 and an opening 103, and a cover body 110 for covering the opening 103. An electronic component 201 is mounted in the mounting section 102. Part of the opening 103 functions as a light passage. The base body 101 may have a recess, with the mounting section 102 inside the recess, and the opening of the recess may be the opening 103. The base body 101 may have a base 104 around the opening 103 that faces the cover body 110. 【0067】 The imaging device 200 of this embodiment comprises an electronic component mounting package 100 and an electronic component 201 which is an image sensor. 【0068】 The substrate 101 may have an insulating portion made of an insulating material and a conductive portion located inside and on the surface of the insulating portion. Power, signals, or both may be transmitted between the outside and inside of the substrate 101 via the conductive portion. The insulating portion may be made of a ceramic material such as an aluminum oxide sintered body (alumina ceramics), an aluminum nitride sintered body, a mullite sintered body, or a glass ceramic sintered body. 【0069】 The lid 110 has a base 111 having a fourth surface S4 and a light-shielding film 1 located on the fourth surface S4. The base 111 may be made of a light-transmitting material (such as glass). The lid 110 is joined to the base 104 of the base 101. This joining may be performed by curing the light-shielding film 1. The light-shielding film 1 has the structure and properties described above. 【0070】 In the electronic component mounting package 100 of this embodiment, the light-shielding film 1 can sufficiently reduce the amount of unwanted light entering the mounting section 102 through the cover 110. Furthermore, the workability of adding the light-shielding film 1 to the base 111 of the cover 110 is improved, leading to improved yield and reduced manufacturing costs. In addition, in the imaging device 200 of this embodiment, the light-shielding film 1 on the cover 110 reduces the amount of unwanted light irradiated onto the electronic component 201, which is the image sensor, thereby reducing the effect of flare or ghosting on the signal of the electronic component 201. Furthermore, since the light-shielding film 1 is included in the cover 110, the height of the device can be reduced compared to when the cover and the light-shielding film are configured as separate components. 【0071】 The embodiments of the present disclosure have been described above. However, the present disclosure is not limited to the light-shielding film 1, optical components 10, 10A, cover 110, electronic component mounting package 100, and imaging device 200 of the above embodiments, and details shown in the embodiments can be modified as appropriate without departing from the spirit of the invention. [Industrial applicability] 【0072】 This disclosure relates to light-shielding films, optical partsIt can be used for lids, packages for mounting electronic components, and imaging devices. [Explanation of symbols] 【0073】 1. Light-shielding film Ha resin Hb Carbon Black F Graphite Filler F1 Grade 1 Graphite Filler F2 Type 2 Graphite Filler F3 Type 3 Graphite Filler L1: First layer (the layer closest to the first face) L2 2nd layer L3 Third layer (the layer closest to the second face) S0 Central face S1 page 1 S2 side 2 10, 10A Optical Components 11 Optical components S3 3rd page 100 Electronic component mounting packages 101 Base 102 Mounting section 103 Opening 110 Lid 111 Base S4 4th page 200 Imaging device 201 Electronic Components (Image Sensors)

Claims

[Claim 1] A light-shielding film having a first surface and a second surface located opposite to the first surface, It contains resin, carbon black, type 1 graphite filler, type 2 graphite filler, and type 3 graphite filler. In the longitudinal section, the longitudinal direction of the first type graphite filler is aligned with at least one of the first and second surfaces, In the longitudinal section, the longitudinal direction of the second type of graphite filler is aligned with the thickness direction of the light-shielding film. In the longitudinal section, the longitudinal direction of the third type of graphite filler is inclined midway between the thickness direction of the light-shielding film and the direction along one of the surfaces. When the layer from the first surface that is 1 / 4 of the thickness of the light-shielding film is called the first layer, the layer from the second surface that is 1 / 4 of the thickness of the light-shielding film is called the third layer, and the layer between the first layer and the third layer is called the second layer, In the first layer, the amount of the first type graphite filler is greater than the sum of the second type graphite filler and the third type graphite filler. In the third layer, the amount of the first type graphite filler is greater than the sum of the second type graphite filler and the third type graphite filler. In the second layer, the sum of the second type graphite filler and the third type graphite filler is greater than the first type graphite filler. Light-blocking film. [Claim 2] The first surface is the surface to which light is irradiated, The first type of graphite filler is located in a layer closer to the second surface than to the central surface between the first and second surfaces. The light-shielding film according to claim 1. [Claim 3] The first type of graphite filler is further located in a layer closer to the first surface than the central surface between the first and second surfaces. The light-shielding film according to claim 2. [Claim 4] The light-shielding film according to claim 1, comprising a plurality of the second type graphite fillers whose surfaces facing each other along the longitudinal direction in a longitudinal cross-section. [Claim 5] The light-shielding film according to claim 1, wherein in a longitudinal section, the resin and the carbon black are surrounded by the first type graphite filler and the second type graphite filler. [Claim 6] The light-shielding film according to claim 1, wherein in a longitudinal section, the resin and the carbon black are surrounded by the first type graphite filler and the third type graphite filler. [Claim 7] The light-shielding film according to claim 1, wherein in a longitudinal section, the resin and the carbon black are surrounded by at least two graphite fillers selected from the first type graphite filler, the second type graphite filler, and the third type graphite filler. [Claim 8] An optical member having a third surface, A light-shielding film according to any one of claims 1 to 7 located on the third surface, An optical component equipped with the following features. [Claim 9] A base having a fourth surface, A light-shielding film according to any one of claims 1 to 7 located on the fourth surface, A lid equipped with a cover. [Claim 10] The mounting section for electronic components, An opening that lets light through, A light-shielding film according to any one of claims 1 to 7, A package for mounting electronic components, equipped with the following features. [Claim 11] The electronic component mounting package according to claim 10, The image sensor mounted in the aforementioned electronic component mounting package, An imaging device equipped with the following features.

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