JP5672680B2 - Window material for solid-state image pickup device package and image pickup apparatus - Google Patents

Description

  The present invention is attached to a light-receiving side opening of a package that houses a solid-state image pickup device, protects the solid-state image pickup device, is used as a light-transmitting window, and has an aberration correction function. The present invention relates to an imaging device using a window material for a solid-state imaging device package.

  In recent years, miniaturization of digital still cameras and video cameras equipped with solid-state imaging devices such as CCDs and CMOSs has progressed, and along with this, imaging devices and optical functional parts mounted have been required to be miniaturized.

  As a method for reducing the size of an imaging apparatus, it has been proposed to implement each filtering function of a color correction filter and an optical low-pass filter with a single glass plate (Patent Document 1). According to this, the number of parts can be reduced, the structure and shape are simplified, and it is said that the downsizing of the imaging device can be achieved by incorporating this into the imaging device.

JP 4-110903 A

On the other hand, the number of pixels in a solid-state imaging device has been increasing year by year, and in order to correct aberrations such as color shift and distortion caused by the lens, the number of lenses tends to increase and the total length of the lens group tends to increase. However, these trends are contrary to the downsizing of the digital still camera and the like from the viewpoint of size. In addition, the optical filter described in Patent Document 1 reduces the number of optical functional parts by combining the filtering functions of the color correction filter and the optical low-pass filter, but is not related to the lens function. It does not contribute to the downsizing of the lens group for high pixels. With such a background, there is a demand for an optical functional component and an imaging apparatus that can cope with downsizing and high pixel size of a camera.
The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical functional component and an imaging apparatus for coping with downsizing and high image quality of a camera equipped with an imaging apparatus. .

As a result of intensive studies to achieve the above object, the present inventor has provided an aberration correction function to the window material for the solid-state image pickup device package, so that the size of the camera can be reduced while supporting the increase in the number of pixels of the solid-state image pickup device. We have found that we can provide optical functional parts that meet the requirements
That is, the window material for a solid-state imaging device package according to the present invention is characterized in that at least one light-transmitting surface has an uneven shape and an α-ray emission amount is 0.005 c / cm ² · hr or less.
The window material is made of glass having a yield point of 580 ° C. or lower.
The window material is made of phosphate glass having an average coefficient of thermal expansion of 50 to 250 ° C. of 100 to 150 × 10 ⁻⁷ K ⁻¹ , and is attached to a resin-made solid-state imaging device package. To do.
Further, the window material is mol%,
P ₂ O ₅ 12~42%,
Al ₂ O ₃ 13-32%,
SiO ₂ 0~17%,
B ₂ O ₃ 0-22%,
Li ₂ O 0-17%,
Na ₂ O 0-27%,
K ₂ O 0~27%,
_{However, Li 2 O + Na 2 O} + K 2 O 18~42%,
MgO + CaO + SrO + ZnO 1-37%,
It is characterized by containing.
Further, the window material is substantially free of Cu.
Further, the window material is characterized in that the outer periphery of the translucent surface is flat.
The imaging device of the present invention includes the solid-state imaging device package window material, a lens group, and the solid-state imaging device package window material and a solid-state imaging device that receives light transmitted through the lens group. Features.

  According to the present invention, the aberration correction function is added to the window material for the solid-state image pickup device package to increase the degree of freedom in optical design of the lens. Therefore, it is possible to cope with the downsizing of the lens group and the increase in the number of pixels of the solid-state image pickup device. Accordingly, it is possible to provide an imaging apparatus that contributes to downsizing of a camera or the like.

It is a side sectional view showing an example of an embodiment of a window material for a solid-state image sensing device package and an imaging device of the present invention. It is the side sectional view and top view showing other examples of the embodiment of the window material for solid-state image sensing device packages of the present invention. It is a top view by the side of the solid-state image sensor of the window material for solid-state image sensor packages in embodiment of FIG. It is a cross-sectional enlarged view of the adhesion part of the window material for solid-state image sensor packages and window frame material in embodiment of FIG. It is a conceptual diagram which shows an example in the manufacturing method of the window material for solid-state image sensor packages of this invention. It is side sectional drawing which shows the other example of embodiment of the window material for solid-state image sensor packages of this invention.

  An embodiment of a window member for a solid-state imaging device package according to the present invention will be described. FIG. 1 is a side sectional view showing an example of an embodiment of a window member 4 for a solid-state image pickup device package and an image pickup apparatus 100 according to the present invention. As shown in FIG. 1, a CCD or CMOS solid-state image pickup device 3 is provided on the bottom surface of a recess of a solid-state image pickup device package (hereinafter referred to as a package) composed of a substrate 1 and a window frame member 2. 4 (hereinafter referred to as a window material) is bonded to the opening of the package in order to hermetically seal the recessed space in which the solid-state imaging device 3 is housed. A plurality of lens groups 10 that refract light from the subject are provided on the subject side of the window material 4 (the back side of the surface facing the solid-state imaging device). Although not shown, a near-infrared cut filter for correcting the color tone and a low-pass filter for reducing moire and false colors may be installed between the window material 4 and the lens group 10.

As the package, an alumina ceramic package or a resin package can be used. However, it is preferable to use a resin package because it can contribute to weight reduction of the image pickup apparatus 100 and has high productivity and low cost. Various resin materials can be used for the resin package without particular limitation. Specifically, thermosetting resins such as epoxy resins, imide resins, polyimide resins, silicone resins, acrylic resins, phenol resins, and unsaturated polyester resins, and thermoplastic resins such as polyphenylene sulfide resins and polysulfone resins can be used. These resins can be appropriately mixed with a curing agent, a release agent, a filler and the like.
The window material 4 needs to use a material having a thermal expansion coefficient comparable to the thermal expansion coefficient of the package so that cracks and distortion do not occur when the window material 4 is attached to the package. When the alumina ceramic package is used, the thermal expansion coefficient of the alumina ceramic is usually in the range of 60 to 75 × 10 ⁻⁷ K ⁻¹ , and the thermal expansion coefficient of the window material 4 is equal to or slightly smaller than 45 to 75 × The range of 10 ⁻⁷ K ⁻¹ is desirable. When a resin package is used, the thermal expansion coefficient of the resin material is 110 to 180 × 10 ⁻⁷ K ⁻¹ , and the thermal expansion coefficient of the window material 4 is the same as or slightly smaller than 100 to 170 ×. The range of 10 ⁻⁷ K ⁻¹ is desirable.
In addition to the embodiment of FIG. 1, the package may be one in which the substrate 1 provided with the solid-state imaging device 3 and the window frame member 2 are integrally formed.

  The window material 4 is bonded to the opening of the package in order to hermetically seal the solid-state imaging device 3. The reason why the solid-state imaging device 3 is hermetically sealed is to prevent dust and the like in the atmosphere from adhering to the light receiving surface of the solid-state imaging device 3 provided in the package and causing image noise. Conventionally, since the window material 4 has not been particularly required except for the hermetic sealing function of the solid-state imaging device 3, it is almost always used in a flat plate shape. On the other hand, along with the increase in the number of pixels of the solid-state imaging device 3, the total length of the lens group 10 of the imaging device 100 tends to be long, while the downsizing of the imaging device 100 is also required. In addition, it has become necessary to reduce the size of the imaging apparatus while supporting the increase in the number of pixels. Therefore, the present inventor forms a concavo-convex shape having an aberration correction function on at least one light-transmitting surface of a window material that has been a flat plate, thereby forming a part of image formation and aberration correction functions by the lens group 10. It gave to the window material 4 and discovered that these subjects were solved.

  There is no particular restriction on the uneven shape formed on the light-transmitting surface of the window material 4, but the shape is uniform at a distance from the optical axis in the in-plane direction perpendicular to the optical axis, with the optical axis of the lens group 10 as the center, It is preferable to have a shape that corrects magnification and spherical aberration, or a shape that corrects astigmatism. By making the shape to correct the magnification and spherical aberration, a part of the imaging function of the lens group 10 can be added to the window member 4 and the entire length of the lens group 10 can be shortened, which is very preferable. In particular, adding a shape for correcting higher-order spherical aberration of the fifth or higher order to the window member 4 makes it possible to correct aberrations that cannot be removed by adjusting each lens position when the lens group 10 is assembled. The performance can be improved, which is preferable. Further, when a plastic lens is used for the lens group 10, particularly when the molding method is injection molding, the refractive index distribution in the lens is generated and astigmatism is likely to occur. By providing the shape of astigmatism to be performed, these problems can be solved. Specifically, by providing an aberration correction function to the window member 4, the lens group 10 is rotated when the lens group 10 is assembled to adjust the position with the window member 4, thereby reducing aberration caused by the lens group 10. The imaging performance can be improved. The concavo-convex shape formed on the translucent surface of the window material 4 may be a concavo-convex shape only on one of the translucent surfaces on the lens group 10 side or the solid-state imaging device 3 side, and the other translucent surface may be a flat surface. Both light-transmitting surfaces may be uneven. FIGS. 2A and 2B are (a) a side sectional view and (b) a plan view of the window member 4 according to the embodiment in which both light-transmitting surfaces are uneven. The concave / convex shape is appropriately optimized depending on the optical design.For example, spherical, aspherical concave lenses, convex lenses, Fresnel lenses, cylindrical lenses, fly-eye lenses, and lenses with a combination of concave and convex, etc. have an aberration correction function. Any uneven shape can be applied as long as the shape is obtained. In addition, when the window material 4 is plate shape, the outer surface which opposes the plate | board thickness direction is called the translucent surface, respectively.

When the window material 4 contains an α-ray emitting element in a certain amount or more and emits α-ray particles, it causes a transient malfunction in the solid-state imaging device 3 and becomes noise. Therefore, the window material 4 emits α-rays. The amount needs to be 0.005 c / cm ² · hr or less. The α-ray particles are charged particles that are released when a radioactive isotope such as uranium (U), thorium (Th), and radium (Ra) that exist in nature undergoes α decay. In order to eliminate noise caused by α-ray particles, these radioisotopes contained as impurities in the material may be removed. For this purpose, it is necessary to manufacture the window material 4 by using a raw material refined as highly as possible and preventing impurities from being mixed in the melting step. For example, when the window material 4 is formed of glass, it is preferable to control impurities in the glass so that the U content is 10 ppb or less and the Th content is 20 ppb or less. Note that it is not preferable that the α-ray emission amount exceeds 0.005 c / cm ² · hr because noise of the solid-state imaging device 3 increases.

  As a method for forming the uneven shape of the light-transmitting surface of the window material 4, for example, a method of press-molding a softened glass lump with a pressing mold is suitably used. As a glass pressing mold, one made of carbide or silicon carbide can be used. In addition, molding under conditions in which the atmosphere is adjusted, such as press molding in an inert gas such as nitrogen, or press molding in a state where the pressure is reduced to a vacuum, is preferably used. In particular, when the concavo-convex shape to be molded has a plurality of inflection points, gas may be involved during pressing, so press molding in a state where the pressure is reduced to a vacuum is preferable. Moreover, the outer periphery may be cut after press molding to adjust the shape. By processing the corners and ridges of the window material after press molding into a curved surface, the breaking strength of the window material 4 is improved, and the generation of foreign matter due to chipping of the corners is suppressed, which is preferable. In addition, when forming a flat part in the translucent surface of the window material 4, it is preferable to form simultaneously with the said press molding, but you may grind | polish separately after press molding.

  The molding conditions in the press molding method are adjusted according to the thermal characteristics (for example, softening point and yield point) of the glass to be molded. At this time, as the molding temperature is lower, the press mold can be used more frequently and the mold replacement frequency is lower, so that the productivity of press molding can be improved. As described above, it is preferable to use a glass having a yield point of 580 ° C. or lower as a glass material in consideration of a press mold. Thereby, since press molding is possible at a relatively low temperature, the number of times the press mold can be used can be increased, and the productivity of press molding is improved. The yield point of the glass material is more preferably 490 ° C. or lower.

  The material used for the window material 4 transmits light from the subject without any limitation, except that the content of the radioisotope in the material is regulated so that the α-ray emission amount becomes a certain value or less as described above. Any material having a high light transmittance can be used. For example, borosilicate glass that has been adjusted so that the amount of α-ray emission conventionally used for the window material 4 is low can be suitably used.

Moreover, as a material used for the window material 4, it is possible to use the window material 4 stably for a long period of time without causing cracks or distortion of the window material 4 by using glass having a thermal expansion coefficient similar to that of the package. Become. It is preferable to use a borosilicate glass having a thermal expansion coefficient of 48 to 75 × 10 ⁻⁷ K ⁻¹ as a glass suitable for bonding with an alumina ceramic package. Moreover, as glass suitable for adhesion | attachment with resin packages, the thermal expansion coefficient of 50-250 degreeC is 100-150 * 10 <^-7> K < ^-1 >, and the phosphate glass which has a thermal expansion coefficient comparable as a resin package. Is preferably used. A resin material such as an acrylic resin having the same thermal expansion coefficient as that of the resin package can also be suitably used.
Phosphate glass has a higher strength than, for example, fluorophosphate glass, and has a small proportion of occurrence of minute chips at the end when optical polishing is performed. For this reason, when an external force is applied to the glass, the possibility of breakage starting from the end portion is low and the strength is high. Moreover, even with the same phosphate glass by a specific range and P ₂ O ₅ component and Al ₂ O ₃ component and an alkali metal component, it is possible to increase the strength of the glass.
Specifically, in mol%,
P ₂ O ₅ 13~42%,
Al ₂ O ₃ 13-32%,
SiO ₂ 0~17%,
B ₂ O ₃ 0-22%,
Li ₂ O 0-17%,
Na ₂ O 0-27%,
K ₂ O 0~27%,
_{However, Li 2 O + Na 2 O} + K 2 O 18~42%,
MgO + CaO + SrO + ZnO 1-37%,
It is preferable to use phosphate glass containing The reason why the preferable range of the content (in mol%) of each component is set as described above will be described below.

P ₂ O ₅ is an essential component for forming a glass network structure, but if it is less than 13%, the stability of the glass deteriorates, and if it exceeds 42%, the strength and weather resistance deteriorate. A preferred range is 25-35%.

Al ₂ O ₃ is an essential component for improving the strength and weather resistance of glass, but if it is less than 13%, the effect cannot be obtained, and if it exceeds 32%, devitrification becomes strong and vitrification becomes difficult. . A preferable range is 17 to 27%, and a more preferable range is 20 to 27%.

SiO ₂ is a component that forms a glass network structure, and has an effect of improving weather resistance. In that case, if it exceeds 17%, vitrification becomes difficult. A preferable range is 12% or less.

B ₂ O ₃ is a component that reinforces the glass structure and facilitates vitrification, but if it exceeds 22%, the weather resistance decreases. A preferred range is 15% or less.

Li ₂ O, Na ₂ O, and K ₂ O are components that improve solubility and mainly adjust the expansion coefficient, and need to contain any of them. When Li ₂ O exceeds 17%, the weather resistance decreases. A preferable range is 12% or less. When Na ₂ O exceeds 27%, the weather resistance decreases. A preferable range is 20% or less. When K ₂ O exceeds 27%, the weather resistance decreases. A preferable range is 20% or less. When the total amount of Li ₂ O, Na ₂ O, and K ₂ O is less than 18% and exceeds 42%, a desired expansion coefficient cannot be obtained, which is not preferable. A preferred range is 25-35%.

  MgO, CaO, SrO, and ZnO are components that improve the solubility. However, when the total amount of these is less than 1%, the effect is not obtained, and when it exceeds 37%, the tendency of devitrification increases, which is not preferable. A preferred range is 10-25%.

Further, as other _{components, La 2 O 3, Y 2} O 3, Gd 2 O 3, Ta 2 O 5, Yb 2 O 3, may also contain such TiO _2.

  As a component which comprises the window material 4, it is preferable not to contain Ba and Zr substantially. Radioisotopes are contained in trace amounts as impurities in the glass raw material, but are particularly abundant in compound raw materials of Ba and Zr. Although it is not impossible to separate radioisotopes from Ba and Zr compound raw materials, the raw material costs are very high and are substantially difficult. Therefore, Ba and Zr are not substantially contained as components constituting the window material 4, thereby preventing radioisotopes from being mixed in, and thus reducing the amount of α rays emitted from the window material 4. .

Since the phosphate glass having these composition ranges has a yield point of 450 to 490 ° C., the durability of the mold can be increased when the concavo-convex shape is formed by press molding. Suitable as glass. _{Further, Li 2 O, Na 2 O} , an alkali metal component _{K 2} O is an effective component to lower the deformation point of the glass, the preferred range of the total amount of these components in the phosphate glass is 25 40%.

The window member 4 is hermetically sealed with an adhesive 6 to a package in which the solid-state imaging device 3 is housed. An ultraviolet curable adhesive may be used for the purpose of shortening the curing time of the adhesive 6. There are various types of ultraviolet curable adhesives, and as an example, the adhesive is cured with ultraviolet rays having a wavelength of 250 to 350 nm. On the other hand, if the glass contains Cu, it absorbs near-infrared and ultraviolet wavelengths, so that the ultraviolet rays do not reach the ultraviolet curable adhesive sufficiently, and it takes a long time to cure. Productivity in the process deteriorates. Further, when Cu is contained in the glass, visible light is also slightly absorbed. Therefore, there is a problem that the sensitivity of the solid-state image pickup device 3 is lowered by reducing the amount of visible light reaching the solid-state image pickup device 3. For these reasons, it is preferable that the window material 4 does not substantially contain Cu when it is bonded to the package using an ultraviolet curable adhesive.
Further, when a thermosetting adhesive is used as the adhesive 6, since the ultraviolet ray transmission of the window material 4 is irrelevant, Cu may be contained for the purpose of providing the window material 4 with a near infrared cut function. Thereby, since the near-infrared cut filter used separately from the window material 4 becomes unnecessary, it can contribute to the cost reduction of the imaging device 100. In addition, when it contains Cu in the composition range of the said phosphate glass, it is preferable to contain 0.1-15 mass% in conversion of CuO.

  An antireflection film made of a dielectric multilayer film or the like, an ultraviolet cut film that reflects ultraviolet rays of 400 nm or less, or a near infrared cut film that reflects near infrared rays of 700 to 1200 nm may be formed on the light transmitting surface of the window material 4. Good.

As for window material 4, it is preferred that the perimeter of a translucent surface is flat. As shown in FIG. 3, the outer periphery (hatched portion in FIG. 3) of the translucent surface that is not the portion through which the light of the subject image of the window material 4 passes is defined as the flat surface 5. The bonding portion of the window material 4 in the package is also a flat shape, and the thickness of the adhesive 6 can be made uniform when bonding. For this reason, it is possible to suppress the occurrence of peeling or distortion during warpage during bonding or a process after bonding, for example, a reflow process during substrate mounting.
Moreover, although the uneven shape of the light-transmitting surface of the window material 4 can be changed by different imaging devices 100, the window frame material 2 is preferably formed in a common shape in order to share parts for cost reduction. In that case, it is preferable that the edge portion of the window member 4 is flat because it is easy to share parts. The flat surface of the window member 4 may be formed on the outer periphery of the light transmitting surface facing the solid-state imaging device 3 as in the embodiment shown in FIG. 2, or the lens group as in the embodiment shown in FIG. You may form in the outer periphery of the translucent surface facing 10.
FIG. 4 shows an enlarged cross-sectional view in which the bonding portion between the window material 4 of the embodiment shown in FIG. 2 and the window frame material 2 of the package is enlarged. The window frame material 2 and the window material 4 are bonded with an adhesive 6, and the protrusion of the adhesive 6 from the joint surface is larger than the flat surface 5 of the window material 4 and protrudes into the uneven portion of the window material 4. It is preferable that the amount of protrusion is substantially uniform. As a result, the stress due to the shrinkage of the adhesive 6 at the time of bonding becomes uniform, so that the uneven shape of the window material 4 is distorted and the desired uneven shape can be reduced. The adhesive 6 is not particularly limited, and an acrylic or epoxy adhesive, a heat resistant glass frit, or the like can be used.
Further, the window material 4 may be formed by using a pressing mold capable of simultaneously press-molding a plurality of windows, and then integrally cutting the plurality of windows and cutting them to take out small pieces. By doing in this way, the manufacturing cost of the window material 4 can be reduced significantly. FIG. 5 is a conceptual diagram showing a manufacturing method in which 25 window members 4 that are simultaneously press-molded are cut along the cutting line 20.

  The window material 4 of the present invention can be manufactured as follows as an example. First, the raw materials are weighed and mixed so that the obtained glass has the composition range of the phosphate glass. This raw material mixture is accommodated in a platinum crucible and heated and melted at a temperature of 1100 to 1350 ° C. in an electric furnace. After thorough stirring and clarification, cool to a temperature that allows press molding. Then, a softened glass lump having a predetermined weight is supplied into a press mold and press-molded. And after taking out glass from the metal mold | die for press and annealing, the unnecessary part of an outer periphery is cut | disconnected and the window material 4 of a predetermined shape is obtained. Alternatively, the plate-like glass may be press-molded after being reheated in a press mold.

  Tables 1 and 2 show Examples 1 to 12 and Comparative Examples 1 to 4 of the present invention. In addition, the glass composition in a table | surface is shown by mol%. These glasses are weighed and mixed so as to have the composition shown in the table, placed in a platinum crucible having an internal volume of about 300 cc, melted at 1100 to 1350 ° C. for 1 to 3 hours, clarified and stirred, and then about 300 to 500 The sample was cast into a rectangular mold having a length of 50 mm, a width of 50 mm and a height of 20 mm preheated to ° C., and then slowly cooled at about 1 ° C./min to prepare a sample. The glass was visually observed at the time of sample preparation, and it was confirmed that there were no bubbles or striae. The weather resistance and α-ray emission amount were evaluated by the following methods.

  As for weather resistance, glass having a predetermined shape (25 mm × 25 mm × 1 mm) subjected to double-sided optical polishing so as to have a thickness of 1 mm is maintained at a temperature of 60 ° C. and a relative humidity of 90%. Time to appear is shown. The α-ray emission amount was measured using a low-level α-ray measuring device (LACS-4000M, manufactured by Sumitomo Chemical Co., Ltd.).

As is clear from Tables 1 and 2, it can be seen that the glass of the comparative example has a bad weather resistance of less than 800 hours compared to the glass of the example. The reason for this is considered to be that there are few Al ₂ O ₃ components in the glass. Also, Comparative Examples 3 and 4 are considered as also reasons that _P 2 _{O 5} component is great. Moreover, since the glass of a comparative example contains Ba and Zr in glass, it turns out that there are many alpha rays discharge | release amounts from glass compared with the glass of an Example.

Next, press molding is performed using the phosphate glass described in Example 3. The glass of Example 3 was adjusted to a length of 7 mm, a width of 10 mm, and a thickness of 0.5 mm, and this was pressed at 500 ° C. using a press mold, with a depth of 280 μm on one side and the other side. A concentric concavo-convex shape having a depth of 20 μm is formed. Subsequently, after cooling to room temperature, the outer periphery is cut by dicing to prepare a window material having a rectangular shape of 6 mm in length and 8 mm in width. When the window material after press molding was confirmed, the shape of the press mold was well transferred, and no defects such as cloudiness were observed on the glass surface.
Next, this window material is bonded to a resin package mainly composed of an epoxy resin. An acrylic ultraviolet curable adhesive is used as the adhesive, and after placing the window material on the package, the adhesive is cured by irradiation with ultraviolet rays for a predetermined time. Further, the lens group is inserted and fixed in a lens holder (not shown), and the lens holder and the package are bonded and fixed, thereby obtaining an imaging device having a thickness in the optical axis direction of about 8 mm.

  According to the present invention, the aberration correction function is added to the window member 4 for the solid-state image pickup device package to increase the degree of freedom in lens optical design. Therefore, the lens group 10 can be downsized and the solid-state image pickup device 3 can have a higher pixel count. Accordingly, it is possible to provide the imaging apparatus 100 that contributes to downsizing of a camera or the like.

  DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Window frame material, 3 ... Solid-state image sensor, 4 ... Window material for solid-state image sensor package, 5 ... Flat surface, 6 ... Adhesive, 10 ... Lens group, 20 ... Cutting line, 100 ... Image sensor .

Claims (5)

At least one of the light-transmitting surfaces has an uneven shape, and the α-ray emission amount is 0.005 c / cm ² · hr or less
In mol%
P ₂ O ₅ 13~42%,
Al ₂ O ₃ 17-32%,
SiO ₂ 0~17%,
B ₂ O ₃ 0-22%,
Li ₂ O 0-17%,
Na ₂ O 0-27%,
K ₂ O 2.0 ~27%,
_{However, Li 2 O + Na 2 O} + K 2 O 18~42%,
MgO + CaO + SrO + ZnO 1-37%,
A window material for a solid-state imaging device package, comprising a phosphate glass containing substantially no Ba and Cu .   The window material for a solid-state imaging device package according to claim 1, wherein the window material is made of glass having a yield point of 580 ° C. or less. The said window material consists of phosphate glass whose average thermal expansion coefficient of 50-250 degreeC is 100-150 * 10 <^-7> K < ^-1 >, and is attached to resin-made solid-state image sensor packages, It is characterized by the above-mentioned. Item 3. The window material for a solid-state imaging device package according to Item 1 or 2. The window material, a solid-state imaging element package window material according to any one of claims 1 to 3, the outer periphery of the light-transmitting surface and wherein the flat. The solid-state image sensor package window material according to any one of claims 1 to 4 , a lens group, the solid-state image sensor package window material, and a solid-state image sensor that receives light transmitted through the lens group. An imaging apparatus comprising:

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