Optical semiconductor equipment

Abstract

To provide an optical semiconductor device with excellent reliability as evaluated by cold thermal shock tests while suppressing the generation of optical noise.SOLUTION: An optical semiconductor device 10 has a semiconductor substrate 12 on which a light-receiving element 11 is provided, a frame-like rib material 13, and a transparent substrate 14, in that order, and an adhesive layer 15 that bonds the rib material 13 and the semiconductor substrate 12. The rib material 13 and adhesive layer 15 are provided to surround the light-receiving element 11. The adhesive layer 15 extends outward from the outer peripheral surface 13b of the rib material 13. The coverage of the adhesive layer 15 on the inner circumferential surface 13a of the rib material 13 is less than 30%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an optoelectronic device. [Background technology]

[0002] Optoelectronic devices such as CMOS sensors and CCD sensors are used in digital cameras and smartphones, and in recent years, their use has increased with the proliferation of surveillance cameras in automobiles and factories, while there is an increasing demand for miniaturization and higher resolution.

[0003] An optoelectronic device, for example, has a hollow structure in which a semiconductor substrate on which a light-receiving element is provided and a glass substrate are laminated with frame-shaped rib material in between. Patent Document 1 proposes an optoelectronic device (solid-state imaging device) in which the rib material and the semiconductor substrate are bonded together with an adhesive. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2005-129720 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, with the increasing demand for further miniaturization and higher resolution of optoelectronic devices in recent years, conventional optoelectronic devices have sometimes been affected by the imaging characteristics. In particular, it has been found that when strong light is incident, optical noise (specifically flare, ghosting, etc.) occurs in the captured image, preventing the device from fully exhibiting its intended imaging characteristics.

[0006] Furthermore, the technology described in Patent Document 1 alone is insufficient to improve the adhesive reliability between the rib material and the semiconductor substrate (especially the reliability evaluated by thermal shock tests).

[0007] In view of the above, the present invention aims to provide an optical semiconductor device that suppresses the generation of optical noise and exhibits excellent reliability as evaluated by thermal shock tests. [Means for solving the problem]

[0008] <Aspects of the Invention> The present invention includes the following embodiments.

[0009] [1] An optoelectronic device comprising, in this order, a semiconductor substrate on which a light-receiving element is provided, a frame-shaped rib material, and a transparent substrate, and having an adhesive layer for bonding the rib material and the semiconductor substrate, The rib material and the adhesive layer are provided so as to surround the light-receiving element. When the rib material and the adhesive layer are viewed from the transparent substrate side, the adhesive layer protrudes outward from the outer surface of the rib material. An optoelectronic device in which the coverage rate of the adhesive layer on the inner circumferential surface of the rib material is 30% or less.

[0010] [2] The optoelectronic device according to [1], wherein the coverage rate of the adhesive layer on the end face of the rib material on the semiconductor substrate side is less than 100%.

[0011] [3] The optoelectronic semiconductor device according to [2], wherein the coverage rate of the adhesive layer on the end face of the rib material on the semiconductor substrate side is 60% or more.

[0012] [4] The optoelectronic device according to any one of [1] to [3], wherein the coverage rate of the adhesive layer on the outer surface of the rib material is 15% or more.

[0013] [5] The optoelectronic device according to any one of [1] to [4], wherein the arithmetic mean roughness Ra of the inner surface of the rib material is 50 nm or more and 3000 nm or less.

[0014] [6] The rib material is composed of a cured product of a photosensitive composition, The photosensitive composition contains a curable compound having a polymerizable group and a photopolymerization initiator, and is alkali-soluble, wherein the optical semiconductor device according to any one of the above [1] to [5].

[0015] [7] The photosensitive composition further contains a colorant, wherein the optical semiconductor device according to the above [6]. Effects of the Invention

[0016] According to the present invention, an optical semiconductor device that suppresses generation of optical noise and has excellent reliability evaluated by a thermal shock test can be provided. Brief Description of the Drawings

[0017] [Figure 1] It is a plan view showing an example of the optical semiconductor device according to the present invention. [Figure 2] It is a cross-sectional view along the line II-II in FIG. 1. [Figure 3] It is a partially enlarged cross-sectional view showing an example of the optical semiconductor device according to the present invention. [Figure 4] It is a partially enlarged cross-sectional view showing another example of the optical semiconductor device according to the present invention. [Figure 5] It is a cross-sectional view showing another example of the optical semiconductor device according to the present invention. [Figure 6] A, B and C are step-by-step cross-sectional views showing a method of manufacturing an example of the optical semiconductor device according to the present invention. [Figure 7] A, B and C are step-by-step cross-sectional views showing a method of manufacturing an example of the optical semiconductor device according to the present invention. [Figure 8] It is a partially enlarged plan view showing an example of a photomask. Mode for Carrying Out the Invention

[0018] Hereinafter, preferred embodiments of the present invention will be described in detail, but the present invention is not limited thereto. In addition, all academic documents and patent documents described in the present specification are incorporated herein by reference.

[0019] First, let's explain the terminology used in this specification. The "main surface" of a layered material (more specifically, a transparent substrate, a semiconductor substrate, a wiring board, etc.) refers to the surface perpendicular to the thickness direction of the layered material. The "arithmetic mean roughness Ra" is measured by the method described in JIS B0601:2013. The "skewness Ssk" is measured by the method described in JIS B0681-2:2018.

[0020] The numerical value for the "thickness" of each layer constituting an optoelectronic device is the "average thickness." The average thickness of each layer constituting an optoelectronic device is the arithmetic mean of 10 measurements obtained by observing the cross-section of each layer cut in the thickness direction with an electron microscope, randomly selecting 10 measurement points from the cross-sectional image, and measuring the thickness of the 10 selected measurement points.

[0021] A "polymerizable group" refers to a functional group that enables polymerization reactions. A "photopolymerization initiator" refers to a compound that generates active species (specifically, radicals, cations, anions, etc.) when irradiated with active energy rays. A "photocationic polymerization initiator" refers to a compound that generates cations (acids) as active species when irradiated with active energy rays. A "photoradical polymerization initiator" refers to a compound that generates radicals as active species when irradiated with active energy rays. Examples of active energy rays include visible light, ultraviolet rays, infrared rays, electron beams, X-rays, alpha rays, beta rays, and gamma rays.

[0022] A "cationic polymerizable group" refers to a functional group that undergoes a chain polymerization reaction in the presence of a cation. An "alicyclic epoxy group" refers to a functional group formed by the bonding of one oxygen atom to two adjacent carbon atoms among the carbon atoms constituting an alicyclic structure, such as the 3,4-epoxycyclohexyl group. A "radical polymerizable group" refers to a functional group having an unsaturated bond that allows for radical polymerization. A "semi-cured state" refers to a state in which the degree of curing can be further increased by a subsequent process (for example, a heating process).

[0023] An "alkali-soluble group" refers to a functional group that enhances solubility in alkaline solutions by interacting with or reacting with alkali. "A photosensitive composition is alkali-soluble" means that the photosensitive composition contains a compound having an alkali-soluble group.

[0024] A "polysiloxane compound" is a compound having a polysiloxane structure composed of siloxane units (Si-O-Si). Examples of polysiloxane structures include linear polysiloxane structures (specifically, linear polysiloxane structures, branched polysiloxane structures, etc.) and cyclic polysiloxane structures.

[0025] Unless otherwise specified, the "main component" of a material refers to the component that is present in the largest quantity by weight.

[0026] "Solid content" refers to the non-volatile components in a composition, and "total solid content" refers to the total amount of the composition's components excluding the solvent.

[0027] In the following, the compound name may be followed by "system" to refer to the compound and its derivatives collectively. When "system" is followed by a compound name to represent a polymer name, it indicates that the repeating units of the polymer originate from the compound or its derivative. Additionally, acrylic and methacrylic may be collectively referred to as "(meth)acrylic." Similarly, acrylate and methacrylate may be collectively referred to as "(meth)acrylate." Furthermore, acryloyl and methacryloyl may be collectively referred to as "(meth)acryloyl."

[0028] "Epoxy adhesives" refer to adhesives that primarily contain compounds having epoxy groups (for example, compounds having at least two epoxy groups in one molecule). "Acrylic adhesives" refer to adhesives that primarily contain (meth)acrylic acid or its derivatives (more specifically, (meth)acrylic acid esters, etc.), or polymers of (meth)acrylic acid or its derivatives.

[0029] Unless otherwise specified, the components and functional groups exemplified herein may be used individually or in combination of two or more.

[0030] The diagrams referenced in the following explanation are schematic representations of each component for ease of understanding, and the size, number, shape, etc., of each component shown may differ from the actual dimensions due to the limitations of drawing creation. Furthermore, for the sake of explanation, components identical to those described earlier may be denoted by the same reference numerals in later diagrams, and their explanations may be omitted.

[0031] <Optical Semiconductor Equipment> The optical semiconductor device according to this embodiment (for example, a solid-state imaging device) comprises a semiconductor substrate on which a photodetector is provided, a frame-shaped rib material, and a transparent substrate in that order, and has an adhesive layer that bonds the rib material and the semiconductor substrate. The rib material and the adhesive layer are provided so as to surround the photodetector. In the optical semiconductor device according to this embodiment, when the rib material and adhesive layer are viewed from the transparent substrate side, the adhesive layer protrudes outward from the outer peripheral surface of the rib material. The coverage rate of the adhesive layer on the inner peripheral surface of the rib material is 30% or less.

[0032] The optical semiconductor device according to this embodiment suppresses the generation of optical noise while exhibiting excellent reliability as evaluated by thermal shock tests (hereinafter sometimes simply referred to as "reliability"). The reason for this is presumed to be as follows.

[0033] In the optical semiconductor device according to this embodiment, the adhesive layer extends outward from the outer surface of the rib material. In other words, in the optical semiconductor device according to this embodiment, the region of the adhesive layer that extends outward is arranged along the outer surface of the rib material, so that the rib material can be stably adhered to the semiconductor substrate during thermal shock testing. For this reason, the optical semiconductor device according to this embodiment has excellent reliability.

[0034] Furthermore, generally, when strong light is incident on an optoelectronic device, stray light is generated in the space inside the rib material (internal space). This generated stray light is reflected from the inner surface of the rib material and incident on the photodetector, resulting in optical noise. Through our research, we have found that if the inner surface of the rib material is covered with adhesive, stray light is more likely to be reflected from the adhesive-covered inner surface. In contrast, in the optoelectronic device according to this embodiment, the coverage rate of the adhesive layer on the inner surface of the rib material is 30% or less, so the reflection of stray light from the inner surface of the rib material can be suppressed. Therefore, the generation of optical noise can be suppressed according to the optoelectronic device according to this embodiment.

[0035] [Configuration of Optoelectronic Devices] The configuration examples of the optical semiconductor device according to this embodiment will be described below with reference to the drawings as appropriate. Figure 1 is a plan view showing an example of the optical semiconductor device according to this embodiment. Figure 2 is a cross-sectional view taken along line II-II in Figure 1.

[0036] As shown in Figures 1 and 2, the optoelectronic device 10 is a laminate comprising a semiconductor substrate 12 on which a light-receiving element 11 is provided, a frame-shaped rib material 13, and a transparent substrate 14 in that order, and having an adhesive layer 15 that bonds the rib material 13 and the semiconductor substrate 12. The rib material 13 and the adhesive layer 15 are provided so as to surround the light-receiving element 11. As shown in Figure 1, a plan view of the rib material 13 and the adhesive layer 15 as seen from the transparent substrate 14 side, the adhesive layer 15 protrudes outward from the outer peripheral surface 13b of the rib material 13. In the optoelectronic device 10 shown in Figure 1, the adhesive layer 15 also protrudes inward from the inner peripheral surface 13a of the rib material 13.

[0037] (Transparent substrate 14) As the transparent substrate 14, for example, a glass substrate, a transparent plastic substrate (more specifically, an acrylic resin substrate, a polycarbonate substrate, etc.) can be used, and a glass substrate is preferred from the viewpoint of reliability. The type of glass is not particularly limited, but examples include quartz glass, borosilicate glass, and alkali-free glass. The thickness of the transparent substrate 14 is, for example, 50 μm or more and 2000 μm or less.

[0038] If necessary, a coating film having functions such as an infrared reflective film (or infrared cut filter), an anti-reflective film (AR coating), a non-reflective film, a protective film, a strengthening film, a shielding film, a conductive film, an anti-static film, a low-pass filter, a high-pass filter, or a band-pass filter may be formed on the surface of the transparent substrate 14. In particular, an anti-reflective film or an infrared reflective film (or infrared cut filter) is preferred because it further reduces optical noise in the captured image.

[0039] In particular, when using an anti-reflective coating, it is preferable to use a multilayer anti-reflective coating containing one or more inorganic materials selected from the group consisting of TiO2, Nb2O5, Ta2O5, CaF2, SiO2, Al2O3, MgS2, ZrO2, NiO, and MgF2.

[0040] These coatings can be applied to one or both main surfaces of the transparent substrate 14. If applied to both main surfaces, the coatings may be of the same type or different types. It is also possible to laminate different types of coatings with the same function on one main surface. Furthermore, it is possible to laminate different types of coatings with different functions on one main surface. The number of layers is not particularly limited and can range from several layers to several tens of layers.

[0041] (Rib material 13) The material of the rib material 13 is not particularly limited, but examples include cured products of photosensitive compositions and cured products of thermosetting resins. From the viewpoint of ease of patterning, cured products of photosensitive compositions are preferred. In other words, from the viewpoint of ease of patterning, it is preferable that the rib material 13 is made of cured products of photosensitive compositions. Details of the photosensitive composition will be described later.

[0042] The shape of the rib material 13 is not particularly limited, as long as it is frame-shaped. In Figures 1 and 2, a rib material 13 having a rectangular tubular structure is shown as an example of a frame shape, but it may also be a rib material having a cylindrical structure, or a rib material having a polygonal tubular structure other than a rectangular tubular shape.

[0043] The length of one side of the rib material 13 is, for example, 0.1 mm or more and 5.0 mm or less, preferably 0.5 mm or more and 2.0 mm or less. The shape of the four corners of the rib material 13 is preferably curved, as shown in Figure 1. When the shape of the four corners of the rib material 13 is curved, stress concentration at the four corners is mitigated during solder reflow and thermal shock testing, which can reduce delamination and cracking of the rib material 13. In order to further reduce delamination and cracking of the rib material 13 during solder reflow and thermal shock testing, the radius of curvature on both the outer and inner sides of the four corners of the rib material 13 is preferably 0.01 mm or more and 1.0 mm or less.

[0044] To obtain an optical semiconductor device with superior reliability, the thickness T (height) of the rib material 13 is preferably 500 μm or less, more preferably 400 μm or less, even more preferably 300 μm or less, even more preferably 150 μm or less, and may also be 140 μm or less, 130 μm or less, 120 μm or less, 110 μm or less, or 100 μm or less. Furthermore, to further suppress the generation of optical noise, the thickness T (height) of the rib material 13 is preferably 10 μm or more, more preferably 12 μm or more, even more preferably 15 μm or more, even more preferably 20 μm or more, and particularly preferably 25 μm or more.

[0045] In order to further miniaturize the optoelectronic device while improving the adhesion between the transparent substrate 14 and the rib material 13, the width W1 of the rib material 13 is preferably 10 μm or more and 300 μm or less, and more preferably 20 μm or more and 250 μm or less.

[0046] (Adhesive layer 15) The adhesive layer 15 is composed of a cured adhesive. Examples of adhesives used as materials for the adhesive layer 15 include epoxy adhesives and acrylic adhesives. Examples of epoxy adhesives include adhesives that mainly contain a compound having an epoxy group and also contain a photocationic polymerization initiator. Examples of acrylic adhesives include adhesives that mainly contain a radical polymerizable compound having a (meth)acryloyl group and also contain a photoradical polymerization initiator. The content of polymerization initiators (photocationic polymerization initiators, photoradical polymerization initiators, etc.) in the adhesive is, for example, 1 part by weight or more and 5 parts by weight or less per 100 parts by weight of the main component (compound having an epoxy group, radical polymerizable compound, etc.).

[0047] To obtain an optoelectronic device with superior adhesion between the semiconductor substrate 12 and the rib material 13, an epoxy adhesive is preferred as the adhesive material for the adhesive layer 15. When using an epoxy adhesive as the adhesive material for the adhesive layer 15, to obtain an optoelectronic device with even better adhesion between the semiconductor substrate 12 and the rib material 13, the main component of the epoxy adhesive is preferably an aromatic epoxy compound having two or more epoxy groups, more preferably a bisphenol epoxy compound (more specifically, bisphenol A epoxy compounds, bisphenol F epoxy compounds, bisphenol S epoxy compounds, etc.), and even more preferably a bisphenol A epoxy compound.

[0048] The adhesive may contain additives such as rheology modifiers and gap spacers. Examples of rheology modifiers include inorganic particles such as fumed silica, precipitated silica, asbestos powder, copper oxide, copper hydroxide, iron oxide, alumina, zinc oxide, lead oxide, magnesia, tin oxide, calcium carbonate, carbon, mica, smectite, and carbon black; organic particles such as polystyrene beads, polyethylene particles, acrylic particles, polysiloxane particles, isoprene rubber particles, and polyamide particles; and organic compounds such as amide wax, modified polyester polyol, ethylcellulose, methylcellulose, and organic bentonite. In order to adjust the viscosity of the adhesive to a range suitable for application, the content of the rheology modifier in the adhesive is preferably 1 to 20 parts by weight, and more preferably 5 to 18 parts by weight, per 100 parts by weight of the main component (compounds having epoxy groups, radical polymerizable compounds, etc.).

[0049] When a gap spacer is incorporated into the adhesive, the thickness of the adhesive layer 15 can be easily adjusted to a preferred range described later. As the gap spacer, particles with a sharp particle size distribution are preferred. Examples of gap spacer materials include silica, calcium carbonate, resin, and rubber. The particle size of the gap spacer can be adjusted according to the thickness of the formed adhesive layer 15. To easily adjust the thickness of the adhesive layer 15 to a preferred range described later, the content of the gap spacer in the adhesive is preferably 0.1 parts by weight or more and 5 parts by weight or less, and more preferably 0.5 parts by weight or more and 2 parts by weight or less, per 100 parts by weight of the main component (compounds having epoxy groups, radical polymerizable compounds, etc.).

[0050] To improve the application accuracy of the adhesive, the viscosity of the adhesive is preferably between 10 Pa·s and 800 Pa·s, and more preferably between 50 Pa·s and 600 Pa·s.

[0051] The width W2 of the adhesive layer 15 can be appropriately changed according to the width W1 of the rib material 13, but for example it is 10 μm or more and 500 μm or less, preferably 10 μm or more and 400 μm or less, and more preferably 20 μm or more and 300 μm or less.

[0052] In order to obtain an optoelectronic device that is highly reliable while having excellent adhesion between the rib material 13 and the semiconductor substrate 12, the distance between the rib material 13 and the semiconductor substrate 12 is preferably 0.01 μm or more and 100 μm or less, more preferably 0.1 μm or more and 80 μm or less, even more preferably 0.5 μm or more and 50 μm or less, and even more preferably 1 μm or more and 30 μm or less. Hereinafter, the distance between the rib material and the semiconductor substrate may be referred to as the "thickness of the adhesive layer".

[0053] (Semiconductor substrate 12) Examples of semiconductor substrates 12 include image sensor substrates. The thickness of the semiconductor substrate 12 is, for example, 50 μm to 800 μm.

[0054] The internal space Z, enclosed by the semiconductor substrate 12, the transparent substrate 14, and the rib material 13, may be a sealed space. In this case, the rib material 13 functions as a partition to prevent moisture and dust from entering the effective pixel area. If ventilation holes are formed in the rib material 13, foreign matter can be prevented from entering the internal space Z by forming the rib material 13 in a labyrinthine pattern.

[0055] Furthermore, in the optoelectronic device 10, the coverage rate of the adhesive layer 15 on the inner circumferential surface 13a of the rib material 13 is 30% or less. Hereinafter, the coverage rate of the adhesive layer on the inner circumferential surface of the rib material may be referred to as the "inner circumferential coverage rate." The method for measuring the inner circumferential coverage rate will be explained with reference to Figure 3, which is an enlarged partial cross-sectional view of the adhesive layer 15 and its surroundings. The inner circumferential coverage rate is measured from electron microscope images of the cross-section of the adhesive layer 15 and its surroundings. In the following explanation, the direction perpendicular to the thickness direction of the rib material 13 is defined as the X direction, and the direction parallel to the thickness direction of the rib material 13 is defined as the Y direction.

[0056] In measuring the inner circumference coverage, first, the length L1 in the Y direction of the inner surface 13a and the length L2 in the Y direction of the area covered by the adhesive layer 15 on the inner surface 13a are measured in the electron microscope image described above. Then, the inner circumference coverage (unit: %) is calculated according to the formula "Inner circumference coverage = 100 × L2 / L1".

[0057] To further suppress the generation of optical noise, the inner circumference coverage is preferably 25% or less, more preferably 20% or less, even more preferably 15% or less, even more preferably 10% or less, particularly preferably 5% or less, and may even be 0%.

[0058] As shown in Figure 3, the adhesive layer 15 may cover at least a portion of the outer circumferential surface 13b of the rib material 13. To obtain a more reliable optoelectronic device, the coverage rate of the adhesive layer 15 on the outer circumferential surface 13b of the rib material 13 is preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, even more preferably 20% or more, particularly preferably 25% or more, and may also be 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more, or 100%. Hereinafter, the coverage rate of the adhesive layer on the outer circumferential surface of the rib material may be referred to as "outer circumferential coverage rate".

[0059] The outer perimeter coverage rate can be measured using the same method as the inner perimeter coverage rate described above. Specifically, first, the length L3 in the Y direction of the outer perimeter surface 13b and the length L4 in the Y direction of the area covered by the adhesive layer 15 on the outer perimeter surface 13b are measured in the electron microscope image above. Then, the outer perimeter coverage rate (unit: %) is calculated according to the formula "Outer perimeter coverage rate = 100 × L4 / L3".

[0060] In order to further miniaturize the optoelectronic device while increasing its reliability, it is preferable that the shortest distance D1 (see Figure 3) from the contact point 12a between the outer peripheral portion 15a of the adhesive layer 15 and the semiconductor substrate 12 to the extension line EL1 of the outer peripheral surface 13b of the rib material 13 in the cross-section of the adhesive layer 15 is 10 μm or more and 75 μm or less. Hereinafter, in the cross-section of the adhesive layer, the shortest distance from the contact point between the outer peripheral portion of the adhesive layer and the semiconductor substrate to the extension line of the outer peripheral surface of the rib material may be referred to as the "overhang length". In order to further miniaturize the optoelectronic device while increasing its reliability, the overhang length is preferably 15 μm or more and 75 μm or less, more preferably 20 μm or more and 75 μm or less, even more preferably 25 μm or more and 75 μm or less, even more preferably 30 μm or more and 75 μm or less, and may also be 35 μm or more and 75 μm or less, 40 μm or more and 75 μm or less, or 45 μm or more and 75 μm or less.

[0061] To further suppress the generation of optical noise, it is preferable that the arithmetic mean roughness Ra of the inner circumferential surface 13a of the rib material 13 be between 50 nm and 3000 nm. When the arithmetic mean roughness Ra of the inner circumferential surface 13a is between 50 nm and 3000 nm, the generated stray light is diffusely reflected when it is reflected off the inner circumferential surface 13a. Even if the diffusely reflected stray light is incident on the photodetector 11, it does not have enough intensity to generate optical noise, so when the arithmetic mean roughness Ra of the inner circumferential surface 13a is between 50 nm and 3000 nm, the generation of optical noise can be further suppressed. To further suppress the generation of optical noise, it is preferable that the arithmetic mean roughness Ra of the inner circumferential surface 13a of the rib material 13 be between 100 nm and 2000 nm, more preferably between 200 nm and 900 nm, and even more preferably between 350 nm and 850 nm. In this specification, "arithmetic mean roughness Ra of the inner surface of the rib material" means the arithmetic mean roughness Ra of at least a portion of the inner surface of the rib material. Furthermore, in the following, a surface with an arithmetic mean roughness Ra of 50 nm to 3000 nm may be simply referred to as "surface surface."

[0062] To further suppress the generation of optical noise, the proportion of the area formed in an uneven shape on the inner circumferential surface 13a of the rib material 13 is preferably 50% or more, more preferably 80% or more, even more preferably 90% or more, and particularly preferably 100% (the entire surface is formed in an uneven shape), when the total area of ​​the inner circumferential surface 13a of the rib material 13 is taken as 100%.

[0063] When the inner surface 13a is formed with an uneven shape, in order to further suppress the generation of optical noise, the skewness Ssk of the inner surface 13a is preferably a negative value, more preferably between -0.80 and -0.10, even more preferably between -0.70 and -0.10, and even more preferably between -0.70 and -0.20. The skewness Ssk indicates the symmetry of the height distribution with respect to the average plane of the uneven surface. When the skewness Ssk is 0, the height distribution is a normal distribution (symmetrical vertically). On the other hand, when the skewness Ssk is a negative value, the surface has many fine valleys, and when the skewness Ssk is a positive value, the surface has many fine peaks.

[0064] The surface irregularity can be regular or irregular, as long as the arithmetic mean roughness Ra is between 50 nm and 3000 nm. To further reduce optical noise, it is preferable that the inner surface 13a is formed with an irregular surface irregularity. When the surface irregularity of the inner surface 13a is irregular, the reflected light from the inner surface 13a can be diffusely reflected more effectively.

[0065] The inner circumferential surface 13a of the rib material 13 may have a bumpy shape formed only in the X direction, or only in the Y direction, or in both the X and Y directions. Here, "a bumpy shape formed only in the X direction (or Y direction)" means that the bumpy shape is observed only when scanned in the X direction (or Y direction), and is not observed when scanned in a direction perpendicular to that direction. To further reduce optical noise, it is preferable that the inner circumferential surface 13a of the rib material 13 has a bumpy shape formed in both the X and Y directions.

[0066] The method for forming the uneven shape on the inner circumferential surface 13a of the rib material 13 is not particularly limited, and examples include a method of forming the rib material 13 from a material containing a filler, a method of forming the unevenness using a mold, a method of using a photomask with unevenness formed on it when patterning a photosensitive composition by photolithography, and a method of forming the rib material 13 by photolithography from a photosensitive composition having a linear structure and a non-linear structure.

[0067] Among these, the method of forming the rib material 13 by photolithography from a photosensitive composition having a linear structure and a non-linear structure is preferred because it can form fine irregularities, reduce the number of steps, and easily form a highly accurate pattern shape. When the rib material 13 is formed by photolithography from a photosensitive composition having a linear structure and a non-linear structure, an irregular shape can be formed on the surface including the inner circumferential surface 13a of the rib material 13. The reason for this is presumed to be that when a photosensitive composition having a linear structure and a non-linear structure is used, a phase separation structure is expressed in the photosensitive composition before the photolithography development step, and as a result, irregularities originating from the phase separation structure are formed on the surface of the rib material 13 after the development step.

[0068] The above-mentioned "structures other than linear structures" include branched structures, network structures, and annular structures. In order to easily adjust the arithmetic mean roughness Ra of the inner circumferential surface 13a of the rib material 13 to a range of 50 nm to 3000 nm, an annular structure is preferred as the structure other than linear. The "photosensitive composition having a linear structure and a structure other than linear structures" may contain a compound having a linear structure and a compound having a structure other than linear, or it may contain a compound having both a linear structure and a structure other than linear. Examples of compounds having a linear structure include polysiloxane compounds having both a linear structure and a structure other than linear, linear polysiloxane compounds, linear polyacrylates, linear polyethers, linear polyesters, linear polyimides, linear polyolefins, etc. From the viewpoint of heat resistance, polysiloxane compounds having both a linear structure and a structure other than linear, or linear polysiloxane compounds are preferred.

[0069] Furthermore, when rib material 13 is formed by photolithography from a photosensitive composition having a linear structure and a non-linear structure, the skewness Ssk of the surface including the inner circumferential surface 13a of the rib material 13 tends to be a negative value. On the other hand, when rib material 13 is formed from a material containing a filler, the skewness Ssk of the surface including the inner circumferential surface 13a of the rib material 13 tends to be a positive value. Details of the above photosensitive composition will be described later.

[0070] The cross-sectional shape of the adhesive layer 15 is not limited to the shape shown in Figure 3. The cross-sectional shape of the adhesive layer 15 may be, for example, the shape shown in Figure 4. In Figure 4, a portion of the end face 13c of the rib material 13 on the semiconductor substrate 12 side is not covered by the adhesive layer 15. In order to further suppress the generation of optical noise, it is preferable that the coverage rate of the adhesive layer 15 on the end face 13c of the rib material 13 on the semiconductor substrate 12 side is less than 100%, as shown in Figure 4. Hereinafter, the coverage rate of the adhesive layer on the end face of the rib material on the semiconductor substrate side may be referred to as the "end face coverage rate".

[0071] The end face coverage rate can be measured using the same method as the inner circumference coverage rate described above. Specifically, first, in the electron microscope image above, measure the length L5 in the width direction of the rib material 13 at the end face 13c and the length L6 in the width direction of the area covered by the adhesive layer 15 at the end face 13c. Then, calculate the end face coverage rate (in %) according to the formula "end face coverage rate = 100 × L6 / L5".

[0072] To further suppress the generation of optical noise, the end face coverage is preferably 99% or less, and may be 98% or less, 97% or less, 96% or less, 95% or less, 94% or less, or 93% or less. To obtain an optical semiconductor device with superior reliability, the end face coverage is preferably 60% or more, more preferably 65% ​​or more, even more preferably 70% or more, even more preferably 75% or more, and particularly preferably 77% or more.

[0073] Furthermore, if the end face coverage rate is less than 100%, there is usually no adhesive covering the inner circumferential surface 13a of the rib material 13, as shown in Figure 4. Therefore, in this specification, if the end face coverage rate is less than 100%, the inner circumferential coverage rate is assumed to be 0%.

[0074] [Configuration of other embodiments] The configuration examples of the optical semiconductor device according to this embodiment have been described above with reference to Figures 1 to 4, but the present invention is not limited to the embodiments described above. For example, in addition to the above-described configuration, the optical semiconductor device according to the present invention may also include a wiring board as shown in Figure 5.

[0075] Figure 5 is a cross-sectional view of an optoelectronic device according to another embodiment of the present invention. The optoelectronic device 50 shown in Figure 5 includes, in addition to the configuration of the optoelectronic device 10 shown in Figure 2, a wiring board 52 (interposer) bonded to the main surface of the semiconductor substrate 12 opposite to the transparent substrate 14 side via a die bond material 51.

[0076] The semiconductor substrate 12 and the wiring board 52 are provided with electrode pads 53 for the semiconductor substrate and electrode pads 54 for the wiring board, respectively. The electrode pads 53 and 54 are electrically connected via metal wires 55. The rib material 13 is positioned between the electrode pads 53 and the light-receiving element 11, and the peripheral portion of the rib material 13 (the area including the wires 55) is sealed with sealing resin 57. In addition, solder balls 56 (external connection terminals) are formed on the main surface 52a of the wiring board 52 opposite to the die bond material 51 side.

[0077] The die bond material 51 is not particularly limited, but thermosetting resins such as epoxy resins and silicone resins that do not degrade easily during reflow at temperatures of around 260°C are preferred.

[0078] The wiring board 52 is a multilayer wiring board having a glass epoxy resin substrate or the like and metal wiring, with wiring and interlayer connection vias formed on its surface and inside. The wiring board 52 also functions as a support substrate to suppress deformation of the semiconductor substrate 12.

[0079] The encapsulating resin 57 is not particularly limited, but thermosetting resins such as epoxy resins, acrylic resins, and silicone resins are preferred, with epoxy resins being preferred from the viewpoint of toughness and heat resistance. From the viewpoint of reducing optical noise such as flare, the encapsulating resin 57 is preferably colored black. Furthermore, from the viewpoint of handling, the encapsulating resin 57 is preferably thixotropic, containing a filler such as silica before curing.

[0080] [Photosensitive composition] Next, a photosensitive composition that can be used as a material for the rib material 13 will be described. Examples of photosensitive compositions that can be used as a material for the rib material 13 include a photosensitive composition that contains a curable compound having a polymerizable group and a photopolymerization initiator, and is alkali soluble. Examples of polymerizable groups include cationic polymerizable groups such as epoxy groups, glycidyl groups, oxetanyl groups, vinyl ether groups, and alkoxysilyl groups, and radical polymerizable groups having an unsaturated bond that can be radically polymerized. From the viewpoint of storage stability of the photosensitive composition, it is preferable that the cationic polymerizable group be one or more selected from the group consisting of glycidyl groups, alicyclic epoxy groups, and oxetanyl groups, and more preferably one or more selected from the group consisting of glycidyl groups and alicyclic epoxy groups. Specific examples of radical polymerizable groups include (meth)acryloyl groups and vinyl groups. The curable compound having a polymerizable group may have both cationic polymerizable groups and radical polymerizable groups in one molecule, or it may have only one of them. Furthermore, a compound having a cationic polymerizable group and a compound having a radical polymerizable group may be used in combination.

[0081] Furthermore, the photosensitive composition contains a compound having an alkali-soluble group. The alkali-soluble group is preferably one or more selected from the group consisting of a monovalent organic group represented by the following chemical formula (X1) (hereinafter sometimes referred to as "X1 group"), a divalent organic group represented by the following chemical formula (X2) (hereinafter sometimes referred to as "X2 group"), a phenolic hydroxyl group, and a carboxyl group. Note that the X1 group is a monovalent organic group derived from N-monosubstituted isocyanuric acid. The X2 group is a divalent organic group derived from N,N'-disubstituted isocyanuric acid.

[0082] [ka]

[0083] In order to form a rib material 13 with excellent heat resistance, it is preferable to use one or more alkali-soluble groups selected from the group consisting of X1 groups and X2 groups.

[0084] The photosensitive composition may contain a coloring agent. The rib material 13 obtained using a photosensitive composition containing a coloring agent can be used, for example, as a light-shielding partition to suppress flare and ghosting. Therefore, by using a photosensitive composition containing a coloring agent, the generation of optical noise can be further suppressed.

[0085] Examples of colorants include organic pigments, inorganic pigments, and dyes. From the viewpoint of heat resistance and colorability, it is preferable to use pigments as colorants. When forming a black colored pattern such as a light-shielding partition, it is preferable to use black pigment as the colorant. In addition to black patterns, other colored patterns include red, yellow, and blue patterns. The arithmetic mean roughness Ra of the inner circumferential surface 13a of the rib material 13 described above can also be adjusted by changing the particle size of the pigment.

[0086] Pigments that absorb a wide range of wavelengths in the visible light region are preferred. Among pigments that absorb a wide range of wavelengths in the visible light region, examples of black organic pigments include anthraquinone-based black pigments, perylene-based black pigments, azo-based black pigments, and lactam-based black pigments. Among these, perylene-based black pigments and lactam-based black pigments are preferred due to their excellent light-shielding properties. Examples of black inorganic pigments include carbon black and black lower-order titanium oxynitride. Examples of other inorganic pigments include composite metal oxide pigments, titanium dioxide, barium sulfate, lead sulfate, yellow lead, red iron oxide, ultramarine, Prussian blue, chromium oxide, antimony white, zinc sulfide, zinc, manganese purple, cobalt purple, and magnesium carbonate. Examples of dyes include azo compounds, anthraquinone compounds, perylene compounds, perinone compounds, phthalocyanine compounds, carbonium compounds, and indigoid compounds.

[0087] Pigments used to obtain colored patterns other than black include chromatic pigments such as red, orange, yellow, green, blue, purple, cyanine, and magenta. Lactam pigments and perylene pigments are preferred as chromatic pigments.

[0088] Specific examples of chromatic pigments include Color Index (CI) Pigment Yellow 1, 10, 83, etc.; CI Pigment Orange 2, 5, 13, etc.; CI Pigment Red 1, 2, 3, etc.; CI Pigment Green 7, 10, 36, etc.; and CI Pigment Blue 1, 2, 15, etc. These pigments can be used individually or in various combinations.

[0089] To further suppress the generation of optical noise, a black pigment (more specifically, a black organic pigment, etc.) or a blue pigment (more specifically, a blue organic pigment, etc.) is preferred as the coloring agent, with a black pigment being more preferred.

[0090] In order to obtain a photosensitive composition with excellent photopolymerization properties while further suppressing the generation of residue and optical noise after development, the amount of colorant is preferably 0.1 parts by weight or more and 10 parts by weight or less, more preferably 0.3 parts by weight or more and 7 parts by weight or less, and even more preferably 0.3 parts by weight or more and 5 parts by weight or less, per 100 parts by weight of the curable compound.

[0091] In order to form a rib material 13 with excellent heat resistance, it is preferable that the photosensitive composition contains a polysiloxane compound. Below, preferred examples of photosensitive compositions containing a polysiloxane compound are described.

[0092] A preferred photosensitive composition (hereinafter sometimes referred to as "specific photosensitive composition") as a material for the rib material 13 contains a polysiloxane compound having a cationic polymerizable group and an alkali-soluble group in one molecule (hereinafter sometimes referred to as "component (A)") and a photopolymerization initiator (hereinafter sometimes referred to as "component (B)"). Component (A) is an example of a curable compound having a polymerizable group.

[0093] {Component (A)} Component (A) is not particularly limited as long as it is a polysiloxane compound having both cationic polymerizable groups and alkali-soluble groups in one molecule. By having both cationic polymerizable groups and alkali-soluble groups in one molecule of component (A), a specific photosensitive composition with excellent developability and curability can be obtained. It is preferable that component (A) has multiple cationic polymerizable groups in one molecule. When component (A) has multiple cationic polymerizable groups in one molecule, a rib material 13 with high crosslink density can be obtained, and as a result, the heat resistance of the rib material 13 tends to be further improved. The multiple cationic polymerizable groups may be of the same type or two or more different functional groups. It is also preferable that component (A) has multiple alkali-soluble groups in one molecule. When component (A) has multiple alkali-soluble groups in one molecule, the removal of unexposed areas during development is improved, and thus the developability tends to be further improved. The multiple alkali-soluble groups may be of the same type or two or more different functional groups.

[0094] Component (A) may have a linear polysiloxane structure or a cyclic polysiloxane structure. To form a rib material 13 with superior heat resistance, it is preferable that component (A) has a cyclic polysiloxane structure. Furthermore, when component (A) has a cyclic polysiloxane structure, the film-forming and developability of the specific photosensitive composition tend to be improved.

[0095] Component (A) may have a polysiloxane structure in its main chain or in its side chains. To form a rib material 13 with superior heat resistance, it is preferable that component (A) has a polysiloxane structure in its main chain. To form a rib material 13 with even superior heat resistance, it is preferable that component (A) has a cyclic polysiloxane structure in its main chain.

[0096] The cyclic polysiloxane structure may be monocyclic or polycyclic. The polycyclic structure may also be polyhedral.

[0097] When component (A) is a polymer having a polysiloxane structure in its main chain, the weight-average molecular weight of the polymer is preferably 10,000 or more and 50,000 or less. When the weight-average molecular weight is 10,000 or more, the heat resistance of the resulting rib material 13 tends to be improved. On the other hand, when the weight-average molecular weight is 50,000 or less, the developability tends to be improved.

[0098] Examples of cationic polymerizable groups in component (A) include epoxy groups, glycidyl groups, vinyl ether groups, oxetanyl groups, and alkoxysilyl groups. From the viewpoint of storage stability of the specific photosensitive composition, it is preferable that the cationic polymerizable group be one or more selected from the group consisting of glycidyl groups, alicyclic epoxy groups, and oxetanyl groups, and more preferably one or more selected from the group consisting of glycidyl groups and alicyclic epoxy groups. Among these, alicyclic epoxy groups are particularly preferred because they have excellent photocationic polymerization properties.

[0099] Examples of alkali-soluble groups in component (A) include X1 groups, X2 groups, phenolic hydroxyl groups, and carboxyl groups. In order to form a rib material 13 with excellent heat resistance, it is preferable that the alkali-soluble groups in component (A) be one or more selected from the group consisting of X1 groups and X2 groups.

[0100] While there are no particular limitations on the method for introducing cationic polymerizable groups into a polysiloxane compound, a method using a hydrosilylation reaction is preferred because it allows for the introduction of cationic polymerizable groups into the polysiloxane compound via chemically stable silicon-carbon bonds (Si-C bonds). In other words, component (A) is preferably a polysiloxane compound that has been organically modified by a hydrosilylation reaction and into which cationic polymerizable groups have been introduced via silicon-carbon bonds. It is also preferable that alkali-soluble groups are introduced into the polysiloxane compound via a hydrosilylation reaction and silicon-carbon bonds.

[0101] Component (A) can be obtained, for example, by a hydrosilylation reaction using the following compounds (α), (β), and (γ) as starting materials. • Compound (α): A polysiloxane compound having at least two SiH groups (hydrosilyl groups) in one molecule. • Compound (β): A compound having a carbon-carbon double bond that is reactive with a SiH group and a cationic polymerizable group in one molecule. • Compound (γ): A compound having a carbon-carbon double bond that is reactive with a SiH group and an alkali-soluble group in one molecule.

[0102] (Compound (α)) Compound (α) is a polysiloxane compound having at least two SiH groups in one molecule. For example, a compound described in International Publication No. 96 / 15194, which has at least two SiH groups in one molecule, can be used. Specific examples of compound (α) include hydrosilyl group-containing polysiloxanes with a linear structure, polysiloxanes with hydrosilyl groups at the molecular ends, and cyclic polysiloxanes with hydrosilyl groups (hereinafter sometimes simply referred to as "cyclic polysiloxanes"). Cyclic polysiloxanes may have a polycyclic structure, and the polycyclic structure may be a polyhedral structure. To form a rib material 13 with high heat resistance and mechanical strength, it is preferable to use a cyclic polysiloxane having at least two SiH groups in one molecule as compound (α). Compound (α) is preferably a cyclic polysiloxane having three or more SiH groups in one molecule. From the viewpoint of heat resistance and light resistance, it is preferable that the group present on the Si atom is either a hydrogen atom or a methyl group.

[0103] Examples of hydrosilyl group-containing polysiloxanes having a linear structure include copolymers of dimethylsiloxane units, methylhydrogensiloxane units, and terminal trimethylsiloxy units; copolymers of diphenylsiloxane units, methylhydrogensiloxane units, and terminal trimethylsiloxy units; copolymers of methylphenylsiloxane units, methylhydrogensiloxane units, and terminal trimethylsiloxy units; and polysiloxanes whose ends are sealed by dimethylhydrogensilyl groups.

[0104] Polysiloxanes having hydrosilyl groups at their molecular ends include polysiloxanes whose ends are sealed by dimethylhydrogensilyl groups, and dimethylhydrogensiloxane units (H(CH3)2SiO 1 / 2 (units), and SiO2 units, SiO 3 / 2 Examples include polysiloxanes, which consist of one or more siloxane units selected from the group consisting of units and SiO units.

[0105] Examples of cyclic polysiloxanes include 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane, 1-propyl-3,5,7-trihydrogen-1,3,5,7-tetramethylcyclotetrasiloxane, 1,5-dihydrogen-3,7-dihexyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5-trihydrogen-1,3,5-trimethylcyclotrisiloxane, 1,3,5,7,9-pentahydrogen-1,3,5,7,9-pentamethylcyclopentasiloxane, and 1,3,5,7,9,11-hexahydrogen-1,3,5,7,9,11-hexamethylcyclohexasiloxane. Among these, 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane is preferred from the viewpoint of availability and the reactivity of the SiH group.

[0106] Compound (α) can be obtained by known synthesis methods. For example, cyclic polysiloxanes can be synthesized by methods described in International Publication No. 96 / 15194, etc. Cyclic polysiloxanes having a polyhedral skeleton can be synthesized by methods described in, for example, Japanese Patent Publication No. 2004-359933, Japanese Patent Publication No. 2004-143449, Japanese Patent Publication No. 2006-269402, etc. Alternatively, commercially available polysiloxane compounds may be used as compound (α).

[0107] (Compound (β)) Compound (β) is a compound having a carbon-carbon double bond that reacts with a SiH group (hydrosilyl group) and a cationic polymerizable group in one molecule, and is a compound for introducing a cationic polymerizable group into a polysiloxane compound. The cationic polymerizable group in compound (β) is the same as the cationic polymerizable group in component (A) described above, and the preferred embodiment is also the same. That is, compound (β) preferably has one or more cationic polymerizable groups selected from the group consisting of a glycidyl group, an alicyclic epoxy group, and an oxetanyl group, more preferably one or more selected from the group consisting of a glycidyl group and an alicyclic epoxy group, and even more preferably an alicyclic epoxy group.

[0108] Groups containing a carbon-carbon double bond that are reactive with the SiH group (hereinafter sometimes simply referred to as "alkenyl groups") include, for example, vinyl groups, allyl groups, methallyl groups, and allyloxy groups (-O-CH2-CH=CH2). From the viewpoint of reactivity with the SiH group, compound (β) preferably has one or more alkenyl groups selected from the group consisting of vinyl groups, allyl groups, and allyloxy groups, and more preferably has one or more alkenyl groups selected from the group consisting of vinyl groups and allyl groups.

[0109] Specific examples of compound (β) include 1-vinyl-3,4-epoxycyclohexane, allyl glycidyl ether, allyl oxetanyl ether, diallyl monoglycidyl isocyanurate, and monoallyl diglycidyl isocyanurate. From the viewpoint of reactivity in cationic polymerization, compound (β) is preferably a compound having one or more functional groups selected from the group consisting of alicyclic epoxy groups and glycidyl groups, and a compound having an alicyclic epoxy group is more preferred. To further enhance the reactivity in cationic polymerization, compound (β) is preferably one or more compounds selected from the group consisting of diallyl monoglycidyl isocyanurate and 1-vinyl-3,4-epoxycyclohexane, and 1-vinyl-3,4-epoxycyclohexane is more preferred.

[0110] (Compound (γ)) Compound (γ) is a compound having a carbon-carbon double bond that reacts with a SiH group and an alkali-soluble group in one molecule, and is a compound for introducing an alkali-soluble group to a polysiloxane compound. The alkali-soluble group in compound (γ) is the same as the alkali-soluble group in component (A) described above, and the preferred embodiment is also the same. That is, it is preferable that compound (γ) has one or more alkali-soluble groups selected from the group consisting of X1 and X2 groups.

[0111] Compound (γ) has a group (alkenyl group) containing a carbon-carbon double bond that is reactive with a SiH group. Examples of the alkenyl group of compound (γ) include the same alkenyl group as exemplified for compound (β) above, and the preferred embodiments are also the same. That is, compound (γ) preferably has one or more alkenyl groups selected from the group consisting of vinyl groups, allyl groups, and allyloxy groups, and more preferably has one or more alkenyl groups selected from the group consisting of vinyl groups and allyl groups.

[0112] To obtain a specific photosensitive composition with superior developability, compound (γ) is preferably one or more selected from the group consisting of diallyl isocyanurate, monoallyl isocyanurate, and 2,2'-diallylbisphenol A, and more preferably one or more selected from the group consisting of diallyl isocyanurate and monoallyl isocyanurate. When monoallyl isocyanurate is used as compound (γ), component (A) having an X1 group as an alkali-soluble group is obtained. When diallyl isocyanurate is used as compound (γ), component (A) having an X2 group as an alkali-soluble group is obtained.

[0113] (Other starting materials) In the hydrosilylation reaction, other starting materials may be used in addition to the above-mentioned compounds (α), (β), and (γ). For example, other starting materials may include alkenyl group-containing compounds different from those described above as compounds (β) and (γ) (hereinafter sometimes referred to as "other alkenyl group-containing compounds").

[0114] In order to adjust the skewness Ssk of the inner circumferential surface 13a of the rib material 13 to a negative value by forming irregularities derived from the phase separation structure on the inner circumferential surface 13a, it is preferable to use a linear polysiloxane compound having alkenyl groups at both ends (hereinafter sometimes referred to as "compound (δ)") as another alkenyl group-containing compound, and to use a cyclic polysiloxane as compound (α). When compound (δ) is used, a polysiloxane compound having a linear structure is obtained as component (A). Furthermore, when a cyclic polysiloxane is used as compound (α) and compound (δ) is used, a specific photosensitive composition having a linear structure and a cyclic structure is obtained. In other words, when a cyclic polysiloxane is used as compound (α) and compound (δ) is used, a linear structure portion (a linear structure portion derived from compound (δ)) and a cyclic structure portion (a cyclic structure portion derived from cyclic polysiloxane) are introduced into component (A). A specific example of compound (δ) is the compound represented by the following general formula (Y).

[0115] [ka]

[0116] In general formula (Y), the ratio of r, s, and t (r:s:t) represents the molar ratio of each structural unit. For example, r+s+t=100. Furthermore, in general formula (Y), the arrangement of structural units is not particularly limited.

[0117] To further suppress the generation of optical noise, the weight-average molecular weight of compound (δ) is preferably between 1,000 and 30,000, and more preferably between 2,000 and 29,000.

[0118] To further suppress the generation of optical noise, the content of structural units derived from compound (δ) in component (A) is preferably 1.0% by weight or more and 10.0% by weight or less, and more preferably 1.2% by weight or more and 5.0% by weight or less, based on 100% by weight of component (A).

[0119] The arithmetic mean roughness Ra of the inner circumferential surface 13a of the rib material 13 and the skewness Ssk of the inner circumferential surface 13a of the rib material 13 can be adjusted, for example, by changing at least one of the content of structural units derived from compound (δ) in component (A) and the weight-average molecular weight of compound (δ).

[0120] (Hydrosilylation reaction) The sequence and method of the hydrosilylation reaction to obtain component (A) are not particularly limited. For example, component (A) can be obtained by a hydrosilylation reaction using the above-mentioned compound (α), compound (β), compound (γ), and other optional starting materials in accordance with the method described in International Publication No. 2009 / 075233. Component (A) obtained using the above-mentioned compound (α), compound (β), compound (γ), and other optional starting materials is, for example, a polymer having multiple cationic polymerizable groups and multiple alkali-soluble groups in one molecule, and having a polysiloxane structure in the main chain.

[0121] To further suppress the generation of optical noise, it is preferable that the content of component (A) in the specific photosensitive composition be 20% by weight or more and 97% by weight or less, relative to the total solid content of the specific photosensitive composition.

[0122] {Component (B)} Component (B) is preferably one or more selected from the group consisting of photocationic polymerization initiators and photoradical polymerization initiators. Since the specific photosensitive composition contains component (A) having a cationic polymerizable group, if the specific photosensitive composition contains a photocationic polymerization initiator as component (B), component (A) can be crosslinked by photocationic polymerization. Furthermore, if component (C), which will be described later, is used, if the specific photosensitive composition contains a photoradical polymerization initiator as component (B), component (C) can be crosslinked by photoradical polymerization. The specific photosensitive composition may contain both a photocationic polymerization initiator and a photoradical polymerization initiator as component (B).

[0123] (Photocationic polymerization initiator) As the photocationic polymerization initiator, for example, known photocationic polymerization initiators can be used. For example, various compounds that are preferred as photocationic polymerization initiators in Japanese Patent Publication No. 2000-1648, Japanese Patent Publication No. 2001-515533, International Publication No. 2002 / 83764, etc., can be cited, but are not particularly limited. As the photocationic polymerization initiator, sulfonate ester compounds, carboxylic acid ester compounds, or onium salt compounds are preferred, onium salt compounds are more preferred, and sulfonium salt compounds are even more preferred.

[0124] There are no particular restrictions on the content of the photocationic polymerization initiator in the specific photosensitive composition. From the viewpoint of the curing speed and the balance of physical properties of the cured product, the content of the photocationic polymerization initiator is preferably 0.1% by weight or more and 10% by weight or less, and more preferably 0.3% by weight or more and 5% by weight or less, based on the total solid content of the specific photosensitive composition.

[0125] (Photoradical polymerization initiator) Examples of photoradical polymerization initiators include acetophenone compounds, acylphosphine oxide compounds, benzoin compounds, α-diketone compounds, biimidazole compounds, polynuclear quinone compounds, triazine compounds, oxime ester compounds, titanocene compounds, xanthone compounds, thioxanthone compounds, ketal compounds, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, and fluoroamine compounds. From the viewpoint of ease of patterning, one or more selected from the group consisting of acetophenone compounds, benzophenone compounds, and oxime ester compounds are preferred as photoradical polymerization initiators, with benzophenone compounds being more preferred.

[0126] Examples of benzophenone compounds include benzyldimethyl ketone, benzophenone, 4,4'-bis(dimethylamino)benzophenone, and 4,4'-bis(diethylamino)benzophenone.

[0127] There are no particular restrictions on the content of the photoradical polymerization initiator in the specific photosensitive composition. From the viewpoint of curing speed and balance of physical properties of the cured product, the content of the photoradical polymerization initiator is preferably 0.1% to 5% by weight, and more preferably 0.3% to 1% by weight, based on the total solid content of the specific photosensitive composition.

[0128] {solvent} The specific photosensitive composition may contain a solvent. For example, the specific photosensitive composition can be obtained by dissolving or dispersing the above-mentioned component (A), component (B), and other components used as needed (described later) in a solvent.

[0129] Specific examples of solvents include hydrocarbon solvents such as benzene; ether solvents such as tetrahydrofuran; ketone solvents such as acetone; glycol solvents such as propylene glycol 1-monomethyl ether 2-acetate; ester solvents such as isobutyl isobutyrate; and halogen solvents such as chloroform. From the viewpoint of the coatability (film-forming stability) of the specific photosensitive composition, glycol solvents are preferred as solvents, and propylene glycol 1-monomethyl ether 2-acetate is more preferred.

[0130] From the viewpoint of the coatability (film-forming stability) of the specific photosensitive composition, the amount of solvent is preferably 0.5 parts by weight or more and 100 parts by weight or less, and more preferably 1 part by weight or more and 70 parts by weight or less, per 100 parts by weight of component (A).

[0131] {other components} The specific photosensitive composition may contain components other than the above-mentioned components (A) and (B) as solid content (components other than the solvent) to the extent that it does not impair the purpose and effects of the present invention. However, in order to further suppress the generation of optical noise and form a rib material 13 with excellent heat resistance, the total content of components (A) and (B) is preferably 50% by weight or more, more preferably 60% by weight or more, and even more preferably 70% by weight or more and 100% by weight or less, based on the total amount of solid content of the specific photosensitive composition.

[0132] Other components include compounds having radical polymerizable groups (radical polymerizable compounds), colorants (specific examples are the same as the compounds listed above as examples of colorants), reactive diluents, sensitizers, polymer dispersants, thermoplastic resins, fillers, crosslinking agents, basic compounds, adhesion modifiers, coupling agents (silane coupling agents, etc.), antioxidants, radical scavengers, mold release agents, flame retardants, flame retardant aids, surfactants, defoamers, emulsifiers, leveling agents, anti-repellent agents, ion trapping agents (antimony-bismuth, etc.), thixotropic agents, tackifiers, storage stability modifiers, ozone degradation inhibitors, light stabilizers, thickeners, plasticizers, thermal stabilizers, conductivity modifiers, antistatic agents, radiation shielding agents, nucleating agents, phosphorus-based peroxide decomposing agents, lubricants, metal deactivators, thermal conductivity modifiers, and property modifiers.

[0133] (Compounds having radical polymerizable groups) The specific photosensitive composition may also contain a compound having a radical polymerizable group (hereinafter sometimes referred to as "component (C)") as another component. Since component (C) is another component (a component other than components (A) and (B)), it is a compound that has a radical polymerizable group and does not have siloxane units. The specific photosensitive composition containing component (C) tends to have excellent deep curing properties (the property of being able to be photocrosslinked to a deep level) when patterning.

[0134] Component (C) may include compounds having radically polymerizable unsaturated bonds (such as ethylenically unsaturated bonds). Examples of ethylenically unsaturated bonds include (meth)acryloyl groups and vinyl groups.

[0135] Specific examples of component (C) include allyl (meth)acrylate, vinyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, butanediol di(meth)acrylate, nonanediol di(meth)acrylate, polypropylene glycol (meth)acrylate, bisphenol A di(meth)acrylate, tris(2-(meth)acryloyloxyethyl) isocyanurate, etc.

[0136] In order to obtain an optical semiconductor device with superior reliability while further suppressing the generation of optical noise, the content of component (C) in the specific photosensitive composition is preferably 1% to 50% by weight, more preferably 5% to 40% by weight, and even more preferably 10% to 30% by weight, based on the total amount of solids in the specific photosensitive composition.

[0137] In addition to the specified photosensitive composition described above, other photosensitive compositions containing cationic polymerizable compounds other than component (A) can also be used as the photosensitive composition material for the rib material 13. Furthermore, a specified photosensitive composition containing component (A) and cationic polymerizable compounds other than component (A) can also be used. Examples of cationic polymerizable compounds other than component (A) include bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, novolacphenol type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, bisphenol F diglycidyl ether, bisphenol A diglycidyl ether, 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel Corporation's "Celoxide® 2021P"), and ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (Daicel Corporation's "Celoxide® 2081"), etc.

[0138] When component (A) is used in combination with a cationic polymerizable compound (curable compound) other than component (A), in order to form a rib material 13 with excellent heat resistance while improving the storage stability of the specific photosensitive composition, the amount of the cationic polymerizable compound other than component (A) is preferably 1 part by weight or more and 10 parts by weight or less, and more preferably 3 parts by weight or more and 8 parts by weight or less, per 100 parts by weight of component (A).

[0139] [Preferred embodiment of an optoelectronic device] In order to obtain an optical semiconductor device that further suppresses the generation of optical noise and exhibits even greater reliability as evaluated in thermal shock tests, the optical semiconductor device according to the present invention preferably satisfies the following condition 1, more preferably satisfies the following condition 2, even more preferably satisfies the following condition 3, and even more preferably satisfies the following condition 4. Condition 1: The end face coverage rate is 60% or more and 99% or less. Condition 2: The above condition 1 is met, and the arithmetic mean roughness Ra of the inner surface of the rib material is 50 nm or more and 3000 nm or less. Condition 3: The above condition 2 is met, and the skewness Ssk of the inner surface of the rib material is a negative value. Condition 4: The above condition 3 is met, and the skewness Ssk of the inner surface of the rib material is between -0.80 and -0.10.

[0140] [Manufacturing method for optoelectronic devices] Next, a preferred manufacturing method for the optical semiconductor device 10 described above will be explained with reference to Figures 6A-C and 7A-C.

[0141] First, a photosensitive composition is applied to a large transparent substrate 14 to form a coating film 100 (Figure 6A) composed of the photosensitive composition. The application method is not particularly limited, and general application methods such as spin coating and slit coating can be used. Next, the coating film 100 is heated to remove the solvent in the coating film 100. The heating temperature of the coating film 100 can be set as appropriate, but is preferably 60°C to 200°C.

[0142] Next, a photomask 101 with a light-transmitting region 101a formed in a predetermined position is placed on the coating film 100, and the coating film 100 is irradiated with an active energy ray E (Figure 6B). As a result, only the coating film 100 located below the light-transmitting region 101a (exposed area 100a) is exposed, and the photocuring reaction proceeds. The cumulative exposure amount during exposure is not particularly limited, but preferably 1 mJ / cm². 2 More than 20000mJ / cm 2 The following is more preferable: 10 mJ / cm² 2 More than 10000mJ / cm 2 The following applies: The time for irradiating the coating film 100 with active energy rays E is preferably 1 second or more and 600 seconds or less, and more preferably 1 second or more and 150 seconds or less.

[0143] Next, the exposed coating 100 is developed. The method of developing the coating 100 is not particularly limited. For example, by contacting the coating 100 with an alkaline developer by immersion or spraying, the unexposed areas 100b are dissolved and removed, thereby forming a patterned, semi-cured rib material 13 on the transparent substrate 14 (Figure 6C). Any commonly used alkaline developer can be used without particular limitation. Specific examples of alkaline developers include organic alkaline aqueous solutions such as tetramethylammonium hydroxide (TMAH) aqueous solution and choline aqueous solution; and inorganic alkaline aqueous solutions such as potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, potassium carbonate aqueous solution, sodium carbonate aqueous solution, and lithium carbonate aqueous solution. From the viewpoint of increasing the contrast between the exposed areas 100a and the unexposed areas 100b, the alkali concentration is preferably 25% by weight or less, more preferably 10% by weight or less, and even more preferably 5% by weight or less. Alcohol or surfactants may be added to the alkaline developer for purposes such as adjusting the dissolution rate. Alternatively, the coating 100 may be washed with water after contacting it with the alkaline developer. When washing the coating 100 with water, it is preferable to remove the moisture from the surface of the coating 100 with compressed air after washing.

[0144] Next, the rib material 13 formed in a semi-cured state on the transparent substrate 14 is heated to further cure the semi-cured photosensitive composition. The heating temperature at this time is preferably 80°C to 350°C, and more preferably 150°C to 250°C. Next, the transparent substrate 14 on which multiple rib materials 13 are formed is diced along the dividing line 102 in Figure 6C to separate each rib material 13 into individual pieces. Hereinafter, a laminate obtained by separating a transparent substrate on which multiple rib materials are formed (more specifically, a transparent substrate on which one rib material is formed) may be referred to as a "ribbed substrate".

[0145] Next, adhesive is applied to the semiconductor substrate 12 on which the light-receiving element 11 is provided, surrounding the light-receiving element 11 to form a frame-shaped coating film 150 made of adhesive (Figure 7A). The method of applying the adhesive is not particularly limited, and methods such as applying with a dispenser, applying with a syringe, screen printing, or stamping can be used. To improve the application accuracy, applying with a dispenser is preferred. Furthermore, to further improve the application accuracy, the adhesive may be applied by combining a coating robot and a dispenser.

[0146] When applying adhesive with a dispenser, either an air-pulse type dispenser or a mono type dispenser can be used. Furthermore, when applying adhesive with a dispenser, the amount of adhesive applied and the width of the coated film 150 can be adjusted by changing the outer diameter of the nozzle, the distance between the nozzle and the semiconductor substrate 12, etc. When using an air-pulse type dispenser, the amount of adhesive applied can also be adjusted by changing the air pressure. When using a mono type dispenser, the amount of adhesive applied can also be adjusted by changing the rotor rotation speed.

[0147] When applying the adhesive, it is preferable to adjust the coating diameter D2 (inner circumference diameter of the coating film 150) of the coating film 150 so that the inner circumference-center line distance, as described later, reaches the target value.

[0148] Next, for example, using a flip-chip bonder, the ribbed substrate 151 obtained in the above procedure is moved above the semiconductor substrate 12 on which the coated film 150 is formed (Figure 7B). At this time, the ribbed substrate 151 and the semiconductor substrate 12 are aligned so that the distance D3 (see Figure 7B) between the extension line EL2 of the inner circumferential surface 13a of the rib material 13 and the center line CL that bisects the coated film 150 in the width direction becomes the target value. Hereinafter, the distance between the extension line of the inner circumferential surface of the rib material and the center line that bisects the coated film in the width direction may be referred to as the "inner circumferential surface-center line distance".

[0149] Next, the rib material 13 is brought into contact with the coating film 150, and the ribbed substrate 151 and the semiconductor substrate 12 are bonded together via the coating film 150, after which the coating film 150 is cured. This forms an adhesive layer 15 (see Figure 7C) that bonds the rib material 13 and the semiconductor substrate 12. The method for curing the coating film 150 can be appropriately selected depending on the type of adhesive that makes up the coating film 150. Specific examples of methods for curing the coating film 150 include curing by heating, curing by ultraviolet irradiation, and a method using both heating and ultraviolet irradiation. After the above procedure, the optoelectronic device 10 shown in Figure 7C is obtained.

[0150] The overhang length, inner circumference coverage, outer circumference coverage, and end face coverage can be adjusted, for example, by changing at least one of the following: the viscosity of the adhesive, the particle size of the gap spacers incorporated into the adhesive, the content of the gap spacers incorporated into the adhesive, the inner surface-centerline distance, the outer diameter of the nozzle, the distance between the nozzle and the semiconductor substrate, the air pressure, and the rotational speed of the rotor. [Examples]

[0151] The following describes embodiments of the present invention, but the present invention is not limited to the following embodiments.

[0152] <Synthesis of curable compounds (polysiloxane compounds)> The synthesis methods for curable compounds P1 and P2 are described below. The weight-average molecular weights of curable compounds P1 and P2 were calculated from chromatograms obtained using Tosoh Corporation's "HLC-8420GPC" (columns: Shodex GPC KD-806M (2) and TSKgel SuperAWM-H (2)) with N,N-dimethylformamide as the solvent at a flow rate of 1.0 mL / min, and converted to standard polystyrene equivalents.

[0153] [Synthesis of curable compound P1] Solution S1 was obtained by adding 143 μL of a xylene solution of a platinum-vinylsiloxane complex (Pt-VTSC-3X, manufactured by Yumicore Precious Metals Japan, containing 3% by weight of platinum) to a mixture of 40 g of diallyl isocyanurate, 29 g of diallyl monomethyl isocyanurate, and 264 g of 1,4-dioxane. Separately, solution S2 was obtained by dissolving 88 g of 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane in 176 g of toluene.

[0154] Then, under a nitrogen atmosphere containing 3 volume% oxygen, solution S2 was heated to a temperature of 105°C, and solution S1 was added dropwise to solution S2 over 3 hours. After the dropwise addition was complete, the mixture was stirred for 30 minutes while maintaining the temperature at 105°C to obtain solution S3. The reaction rate of the alkenyl groups of the compounds contained in the obtained solution S3 was then determined. 1 When measured by 1H-NMR, the reaction rate was found to be over 95%.

[0155] In addition, solution S4 was obtained by dissolving 62 g of 1-vinyl-3,4-epoxycyclohexane in 62 g of toluene.

[0156] Then, under a nitrogen atmosphere containing 3% by volume of oxygen, solution S3 was heated to a temperature of 105°C, and solution S4 was added dropwise to solution S3 over 1 hour. After the dropwise addition was complete, the mixture was stirred for 30 minutes while maintaining the temperature at 105°C to obtain solution S5. The reaction rate of the alkenyl groups of the compounds contained in the obtained solution S5 was then determined. 1 When measured by 1H-NMR, the reaction rate was found to be over 95%.

[0157] Next, after cooling solution S5, the solvents (toluene, xylene, and 1,4-dioxane) were removed from solution S5 under reduced pressure to obtain a solid. Then, propylene glycol 1-monomethyl ether 2-acetate (hereinafter referred to as "PGMEA") was added to the obtained solid to obtain solution SP1 containing curable compound P1 (concentration of curable compound P1: 70% by weight). Curable compound P1 was a polysiloxane compound (a polymer with a weight-average molecular weight of 30,000) having multiple cationic polymerizable groups (specifically alicyclic epoxy groups) and multiple alkali-soluble groups (specifically X2 groups) in one molecule, and having a cyclic polysiloxane structure in its main chain.

[0158] [Synthesis of curable compound P2] Solution SP2 (concentration of curable compound P2: 70% by weight) containing curable compound P2 was obtained by the same synthesis method as described in [Synthesis of curable compound P1] above, except that solution S1 was obtained by adding 143 μL of a xylene solution of a platinum-vinylsiloxane complex (Pt-VTSC-3X, manufactured by Yumicore Precious Metals Japan, containing 3% by weight of platinum) to a mixture of 40 g of diallyl isocyanurate, 29 g of diallyl monomethyl isocyanurate, 3.4 g of a linear polysiloxane compound, and 264 g of 1,4-dioxane. The linear polysiloxane compound was the compound represented by the general formula (Y) described above. Furthermore, the linear polysiloxane compound had a molar ratio of each structural unit (r, s, and t ratio) of r:s:t = 30:0:70 and a weight-average molecular weight of 26000.

[0159] The curable compound P2 was a polysiloxane compound (a polymer with a weight-average molecular weight of 30,000) having multiple cationic polymerizable groups (specifically alicyclic epoxy groups), multiple alkali-soluble groups (specifically X2 groups), and a linear structural portion (a linear structural portion derived from the above-mentioned linear polysiloxane compound) in one molecule, and having a cyclic polysiloxane structure in its main chain.

[0160] <Preparing other materials> In addition to the above-mentioned solutions SP1 and SP2 and PGMEA, the following materials were prepared as materials for the photosensitive composition. • 3',4'-Epoxycyclohexylmethyl 3,4-Epoxycyclohexanecarboxylate (Daicel Corporation's "Celoxide® 2021P," hereinafter referred to as "2021P") • Ditrimethylolpropanetetraacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., "AD-TMP," a radical polymerizable compound having four acryloyl groups in one molecule, hereinafter referred to as "AD-TMP") • Sulfonium salt-based photocationic polymerization initiator (SunApro Co., Ltd.'s "CPI-210S," hereinafter referred to as "CPI-210S") • Benzophenone compounds as photoradical polymerization initiators (Omnirad® 651, manufactured by IGM Resins, hereinafter referred to as "651") • Black organic pigment (NPFT-80565, manufactured by Nippon Pigment Co., Ltd.) • Blue organic pigment (Dainichi Seika Kogyo Co., Ltd.'s "Pigment Blue 15") • Yellow organic pigment (Dainichi Seika Kogyo Co., Ltd.'s "Pigment Yellow 83")

[0161] <Preparation of photosensitive composition> The materials listed in Table 1 were blended in the amounts specified in Table 1 to obtain the photosensitive compositions PS1 to PS5 used in the examples and comparative examples, respectively. When curable compounds P1 and P2 were blended, they were blended as solutions SP1 and SP2, respectively. In Table 1, the amount of PGMEA in the photosensitive compositions PS1 to PS5 also includes the amount of PGMEA in solution SP1 or solution SP2. In Table 1, "-" means that the material was not blended.

[0162] [Table 1]

[0163] <Preparation of adhesive> [Preparing the materials] The following materials were prepared as adhesive components. • Bisphenol A-based epoxy compound (Mitsubishi Chemical Corporation's "jER828," hereinafter referred to as "828") · CPI-210S • Tripropylene glycol diacrylate (Daicel Corporation's "TPGDA," a radical polymerizable compound having two acryloyl groups in one molecule; hereinafter referred to as "TPGDA") 651 • Rheology modifier (AEROSIL® R972, manufactured by Nippon Aerosil Co., Ltd., fumed silica particles surface-treated with dimethyldichlorosilane, particle size: 16 nm, hereinafter referred to as "R972") • Gap spacer with a median diameter of 10 μm (Ube Eximo Co., Ltd.'s "HighPresica® N3N", high-purity monodisperse spherical silica particles, hereinafter referred to as "N3N-10") • Gap spacer with a median diameter of 20 μm (Ube Eximo Co., Ltd.'s "HighPresica® N3N", high-purity monodisperse spherical silica particles, hereinafter referred to as "N3N-20")

[0164] [Mixing the ingredients] The materials listed in Table 2 were blended in the amounts specified in Table 2. The resulting mixture was then kneaded in a three-roll mill (three times) to obtain adhesives AD1 to AD7, which were used in the examples and comparative examples, respectively. In Table 2, "-" indicates that the material was not blended. The "viscosity" in Table 2 is the viscosity indicated by the Brookfield rotational viscometer (Brookfield HBDV-I) 3 minutes after the start of measurement (rotation), using spindle No. 3, measurement temperature: 25°C, and rotation speed: 50 rpm.

[0165] [Table 2]

[0166] <Fabrication of Optoelectronic Devices> The following describes the methods for fabricating the optical semiconductor devices of Examples 1 to 16, Comparative Example 1, and Comparative Example 2.

[0167] [Example 1] (Manufacturing Process of Ribbed Substrate) The photosensitive composition PS1 was applied onto a glass substrate serving as a transparent substrate by a spin coater to obtain a first laminate in which a coating film formed of the photosensitive composition PS1 was formed on the glass substrate. Next, the first laminate was heated for 10 minutes on a hot plate heated to a temperature of 120°C. Then, using a manual exposure machine ("MA-1300" manufactured by Dainippon Kagaku Kenkyusho Co., Ltd., lamp: high-pressure mercury lamp), through a photomask 101 shown in FIG. 6B (photomask 101 having a light-transmitting region 101a with a width of 150 µm), with an integrated exposure amount of 3000 mJ / cm 2 Under the above conditions, the coating film of the first laminate after heating was irradiated with light to expose the coating film (specifically, soft contact exposure).

[0168] Then, the first laminate after exposure was left to stand for 1 minute in an atmosphere at a temperature of 25°C, and then immersed in a TMAH aqueous solution serving as an alkaline developer (TMAH concentration: 2.38 wt%) for 60 seconds. Next, the first laminate immersed in the alkaline developer was washed with water for 30 seconds, and then water on the surface was removed with compressed air. Thus, a second laminate including a patterned coating film (specifically, a coating film patterned into a frame shape in a semi-cured state) on the glass substrate was obtained. Next, the second laminate was heated for 30 minutes on a hot plate heated to a temperature of 230°C to further cure the patterned coating film, thereby obtaining a third laminate including a plurality of frame-shaped (square cylindrical) rib materials (thickness: 100 µm, width: 150 µm, side length: 0.9 mm) on the glass substrate.

[0169] Next, the third laminate was cut for each rib material with a dicing blade to obtain a ribbed substrate (the singulated third laminate).

[0170] (Adhesive Coating Step) First, a semiconductor substrate laminate was prepared in which a semiconductor substrate on which a photodetector is provided is bonded to a wiring board via a die bond material, and electrode pads on the semiconductor substrate and electrode pads on the wiring board are electrically connected via metal wires. Next, adhesive AD1 was applied around the photodetector in the semiconductor substrate laminate. Specifically, an air pulse type dispenser (ML-808GX, manufactured by Musashi Engineering Co., Ltd.) and a desktop coating robot (IMAGE MASTER 350PC SMART, manufactured by Musashi Engineering Co., Ltd.) were combined to adjust the coating diameter (inner diameter of the coated film) so that the inner surface-center line distance in the bonding process described later was 90 μm, and adhesive AD1 was applied around the photodetector. When applying adhesive AD1, a nozzle with an inner diameter of 100 μm and an outer diameter of 150 μm (DSHN-M2-0.10F, manufactured by Musashi Engineering Co., Ltd.) was used. Furthermore, when applying adhesive AD1, the dispenser air pressure was set to 300 kPa, the distance between the nozzle and the semiconductor substrate (hereinafter sometimes referred to as "nozzle spacing") was set to 40 μm, and the application speed was set to 8 mm / s.

[0171] (Adhesion process) Next, a flip-chip bonder (CB-505, manufactured by Athlete FA Co., Ltd.) was used to laminate the ribbed substrate obtained in the procedure described above with a semiconductor substrate laminate coated with adhesive AD1. Specifically, the semiconductor substrate laminate coated with adhesive AD1 was set on the flip-chip bonder's stage, and the side of the ribbed substrate without ribs was adsorbed and fixed with a collet. Then, while checking with a camera attached to the flip-chip bonder, the collet was moved to a position above the adhesive AD1 applied to the semiconductor substrate laminate. At this time, the distance between the inner surface and the center line was adjusted to 90 μm. After that, the position of the collet was gradually brought closer to the semiconductor substrate laminate, and when the load detection sensor attached to the collet showed 1N, the adsorption of the ribbed substrate by the collet was released, and a fourth laminate was obtained in which the ribbed substrate and the semiconductor substrate laminate were laminated via adhesive AD1.

[0172] Next, the fourth laminate was subjected to an integrated exposure of 3000 mJ / cm². 2After exposure under these conditions, the material was heated in an oven at 200°C for 2 hours. This bonded the rib material to the semiconductor substrate laminate. Next, the area around the rib material of the fourth laminate (the region including the wires) was sealed with sealing resin, and solder balls were formed on the side of the wiring board opposite to the semiconductor substrate side to obtain the optical semiconductor device of Example 1. The optical semiconductor device of Example 1 had the structure shown in Figure 5.

[0173] [Examples 2-6, 9-11, 13, 16, Comparative Example 1 and Comparative Example 2] Except for the type of photosensitive composition, the type of adhesive, the inner surface-center line spacing, and the air pressure being as described in Tables 3 and 4 below, the photosemiconductor devices for Examples 2-6, 9-11, 13, 16, Comparative Example 1, and Comparative Example 2 were obtained using the same method as in Example 1.

[0174] [Examples 7 and 8] Except for the fact that the adhesive was applied using a combination of a mono-type dispenser (Hyoshin Equipment Co., Ltd. "3HD006G30") and a desktop coating robot (Janome Corporation "JR3300"), that a nozzle manufactured by Hyoshin Equipment Co., Ltd. (model "FST100", inner diameter: 100 μm, outer diameter: 200 μm) was used instead of a nozzle manufactured by Musashi Engineering Co., Ltd., and that the type of adhesive, the inner surface-center line spacing, and the nozzle spacing were as described in Table 3 below, the optoelectronic devices of Examples 7 and 8 were obtained using the same method as in Example 1. The rotation speed of the rotor when using the mono-type dispenser was as described in Table 3 below.

[0175] [Example 12] The photoelectronic device of Example 12 was obtained using the same method as in Example 1, except that the photomask 202 shown in Figure 8 was used instead of the photomask 101 shown in Figure 6B, and the inner surface-center line spacing was changed to 120 μm. The photomask 202 used had multiple light-transmitting regions 202a with a width of 150 μm arranged in a grid pattern. Furthermore, the inner surface 202b of the light-transmitting region 202a had corrugated irregularities (depth of recesses: 50 μm, pitch of protrusions: 58 μm), and these corrugated irregularities were formed only in a direction perpendicular to the thickness direction of the photomask 202. No irregularities were formed on the photomask 101.

[0176] [Examples 14 and 15] The type of photosensitive composition and the cumulative exposure amount when irradiating the coating film of the first laminate after heating with light are specified as 5000 mJ / cm². 2 Except for the change made, the optical semiconductor devices of Examples 14 and 15 were obtained in the same manner as in Example 1, respectively.

[0177] <Methods for measuring and evaluating physical properties> Next, we will explain the methods for measuring and evaluating various physical properties.

[0178] [Surface shape of rib material] Using a 3D measuring laser microscope (Olympus "LEXT® OLS5100"), the arithmetic mean roughness Ra and skewness Ssk of the inner surface of the rib material of a ribbed substrate were measured. For the measurement of the arithmetic mean roughness Ra, 10 measurement locations (evaluation length: 20 μm) were randomly selected on the inner surface of the rib material. At the selected measurement locations, the arithmetic mean roughness Ra was measured in a direction perpendicular to the thickness direction of the rib material. The arithmetic mean of the 10 obtained measurements was used as the evaluation value (arithmetic mean roughness Ra shown in Tables 3 and 4 below). For the measurement of skewness Ssk, 10 measurement locations (20 μm × 20 μm square areas) were randomly selected on the inner surface of the rib material. The skewness Ssk at the selected measurement locations was measured, and the arithmetic mean of the 10 obtained measurements was used as the evaluation value (skewness Ssk shown in Tables 3 and 4 below).

[0179] [Cross-sectional observation of the adhesive layer] Ten measurement locations were randomly selected in and around the adhesive layer of the optoelectronic device. At each of the cross-sections of the selected measurement locations, the following values ​​1) to 6) were obtained using a scanning electron microscope (Hitachi High-Tech Corporation's "Miniscope TM3030Plus," observation magnification: 800x). For each of the following 1) to 6), the arithmetic mean of the 10 obtained values ​​was used as the evaluation value shown in Tables 3 and 4 below. 1) Thickness of the adhesive layer 2) Width of the adhesive layer 3) Overhang length 4) Inner circumference coverage 5) Perimeter coverage rate 6) End face coverage

[0180] [Reliability based on thermal shock testing] Five optoelectronic devices were prepared for each example and comparative example, and thermal shock tests were conducted on each using a heat shock test apparatus (Hitachi Global Life Solutions "ES-57L"). The thermal shock test consisted of holding the optoelectronic device in a -50°C atmosphere for 30 minutes, followed by holding it in a 125°C atmosphere for 30 minutes, with each cycle repeated 100 times. Next, the optoelectronic devices were observed from the glass substrate side using an optical microscope and judged according to the following criteria. If the judgment result was A or B, it was evaluated as "excellent reliability as evaluated by thermal shock testing." On the other hand, if the judgment result was C, it was evaluated as "not excellent reliability as evaluated by thermal shock testing." A: No delamination of the rib material was observed in any of the five optoelectronic devices. B: Delamination of the rib material (specifically, partial delamination) was observed in one of the five optoelectronic devices, but the total number of delaminate areas (the total number of delaminate areas on all five optoelectronic devices) was only one. C: Delamination of the rib material (specifically, partial delamination) was observed in at least one of the five optoelectronic devices, and the total number of delaminate locations (total of delaminate locations on the five optoelectronic devices) was two or more.

[0181] [Ghost Index] First, for the optoelectronic device under evaluation, the number of pixels exceeding a predetermined threshold (1 / 100 millionth of the brightness of the light source) (hereinafter referred to as "abnormal pixel count") was determined using a ghost flare evaluation system (GCS-2T, manufactured by Tsubosaka Electric Co., Ltd.). Then, the value obtained by dividing the abnormal pixel count by the total number of pixels (abnormal pixel count / total number of pixels) was calculated. Hereafter, the value obtained by dividing the abnormal pixel count by the total number of pixels (abnormal pixel count / total number of pixels) may be referred to as the abnormal pixel count ratio.

[0182] Then, the abnormal pixel count ratio of Comparative Example 1 was set to 100, and the abnormal pixel count ratios of Examples 1 to 16 and Comparative Example 2 were normalized. The normalized value (hereinafter referred to as the "ghost index") was used as an indicator of the performance in suppressing ghosting. If the ghost index was 80 or less, it was evaluated that ghosting was being suppressed. On the other hand, if the ghost index exceeded 80, it was evaluated that ghosting was not being suppressed.

[0183] <Result> Tables 3 and 4 show, respectively, the type of photosensitive composition used, the type of adhesive used, the type of photomask used, the inner surface-center line spacing, the nozzle outer diameter, the nozzle spacing, the air pressure (Examples 1-6, Examples 9-16, Comparative Examples 1 and 2), the rotor rotation speed (Examples 7 and 8), the arithmetic mean roughness Ra of the inner surface of the rib material, the skewness Ssk of the inner surface of the rib material, the thickness of the adhesive layer, the width of the adhesive layer, the overhang length, the inner surface coverage rate, the outer surface coverage rate, the end surface coverage rate, the reliability determination results from the thermal shock test, and the ghost index for Examples 1-16, Comparative Examples 1 and 2. Note that "101" in the "Type of Photomask" column of Tables 3 and 4 means photomask 101 (see Figure 6B). Also, "202" in the "Type of Photomask" column of Table 4 means photomask 202 (see Figure 8).

[0184] [Table 3]

[0185] [Table 4]

[0186] In the optical semiconductor devices of Examples 1 to 16, the overhang length was greater than 0 μm. In other words, in the optical semiconductor devices of Examples 1 to 16, when the rib material and adhesive layer were viewed from the glass substrate side, the adhesive layer protruded outward from the outer surface of the rib material. In the optical semiconductor devices of Examples 1 to 16, the inner circumference coverage was 30% or less.

[0187] In the optical semiconductor devices of Examples 1 to 16, the reliability evaluation result from the thermal shock test was A or B. Therefore, the optical semiconductor devices of Examples 1 to 16 had excellent reliability as evaluated by the thermal shock test. In the optical semiconductor devices of Examples 1 to 16, the ghosting index was 80 or less. Therefore, the optical semiconductor devices of Examples 1 to 16 were able to suppress the occurrence of ghosting.

[0188] In Comparative Example 1, the inner circumference coverage rate exceeded 30%. In Comparative Example 2, the overhang length was 0 μm. In other words, in Comparative Example 2, when the rib material and adhesive layer were viewed from the glass substrate side, the adhesive layer did not extend beyond the outer circumference of the rib material.

[0189] In Comparative Example 1, the ghosting index was 100. Therefore, the optical semiconductor device in Comparative Example 1 failed to suppress the occurrence of ghosting. In Comparative Example 2, the reliability evaluation result from the thermal shock test was C. Therefore, the optical semiconductor device in Comparative Example 2 did not have excellent reliability as evaluated by the thermal shock test.

[0190] The results above demonstrate that the present invention can provide an optical semiconductor device that suppresses the generation of optical noise while exhibiting excellent reliability as evaluated by thermal shock tests. [Explanation of symbols]

[0191] 10, 50 Optoelectronic devices 11. Photodetector 12 Semiconductor substrates 13 Rib material 14 Transparent substrate 15 Adhesive layer

Claims

1. An optoelectronic device comprising, in this order, a semiconductor substrate on which a light-receiving element is provided, a frame-shaped rib material, and a transparent substrate, and having an adhesive layer for bonding the rib material and the semiconductor substrate, The rib material and the adhesive layer are provided so as to surround the light-receiving element. When the rib material and the adhesive layer are viewed from the transparent substrate side, the adhesive layer protrudes outward from the outer surface of the rib material. The coverage rate of the adhesive layer on the inner circumferential surface of the rib material is 30% or less. An optoelectronic device in which the coverage rate of the adhesive layer on the end face of the rib material on the semiconductor substrate side is 60% or more and less than 100%.

2. The optical semiconductor device according to claim 1, wherein the coverage rate of the adhesive layer on the outer surface of the rib material is 15% or more.

3. The optoelectronic device according to claim 1, wherein the arithmetic mean roughness Ra of the inner circumferential surface of the rib material is 50 nm or more and 3000 nm or less.

4. The rib material is composed of a cured product of a photosensitive composition, The photosensitive composition contains a curable compound having polymerizable groups and a photopolymerization initiator, and is alkali soluble, as described in claim 1, for the photoelectronic device according to claim 1.

5. The photosensitive composition further contains a coloring agent, as described in claim 4, for the optoelectronic device according to claim 4.

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