Method for manufacturing optical coupler, optical coupler, photoelectric conversion circuit module, and optical transceiver

Abstract

This method for manufacturing an optical coupler comprises: a preparation step for preparing a translucent substrate (11) having a first main surface (SU11) and a second main surface (SU12) arranged in a first direction (DIR1); a first coating step in which a first photosensitive glass paste (12) containing a first filler (P1) is coated on the first main surface (SU11); a masking step in which a gradation mask (10) formed in a binary pattern is disposed on the second main surface (SU12); an exposure step in which the second main surface (SU12) is irradiated with ultraviolet light and the first photosensitive glass paste (12) is exposed; a developing step in which the gradation mask (10) is removed from the second main surface (SU12) and the first photosensitive glass paste (12) is developed; and a curing step in which the light-transmitting substrate (11) is removed from the developed first photosensitive glass paste (12) and the first photosensitive glass paste (12) is cured. The longest length (r1) of the first filler (P1) is longer than the wavelength of the ultraviolet light.

Description

Technical Field

[0001] The invention relates to a manufacturing method of an optical coupler, an optical coupler, a photoelectric conversion circuit module and an optical transceiver. Background Art

[0002] For example, the grayscale mask described in Patent Document 1 is used for the purpose of manufacturing microlenses, etc. The grayscale mask described in Patent Document 1 is composed of a plurality of pixels arranged adjacent to each other. There is at least one unit area in one pixel. The unit area is composed of a first area as a light-transmitting area and a second area as a light-shielding area that is not light-transmitting. The light transmittance of the unit area is determined by the area ratio of the light-transmitting area to the light-shielding area.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 5764948 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In the manufacture of optical couplers such as microlenses, if the grayscale mask described in Patent Document 1 is used as a photomask, the light is diffracted during exposure due to the periodic structure of the light-transmitting region and the light-shielding region. The diffracted light is irradiated in a direction other than the target direction at a high level. As a result, the photosensitive material may not be exposed as designed, and the processing accuracy may be reduced.

[0008] Therefore, an object of the present invention is to provide a method for manufacturing a photocoupler, a photocoupler, a photoelectric conversion circuit module, and an optical transceiver capable of suppressing a decrease in processing accuracy.

[0009] Technical solutions to solve problems

[0010] A method for manufacturing an optical coupler according to one embodiment of the present invention includes:

[0011] A preparation step of preparing a light-transmitting substrate having a first main surface and a second main surface arranged in a first direction;

[0012] A first coating step of coating a first photosensitive glass paste containing a first filler on the first main surface;

[0013] A masking step of disposing a grayscale mask formed in a binary mode on the second main surface;

[0014] An exposure step of irradiating ultraviolet rays to the second main surface to expose the first photosensitive glass paste;

[0015] a developing step of removing the grayscale mask from the second main surface and developing the first photosensitive glass paste; and

[0016] a curing step of removing the light-transmitting substrate from the developed first photosensitive glass paste and curing the first photosensitive glass paste;

[0017] The longest length of the first filler is longer than the wavelength of the ultraviolet light.

[0018] When the longest length of the first filler is longer than the wavelength of the ultraviolet light, the ultraviolet light diffracted by the grayscale mask is scattered by the first filler. As a result, the diffracted light is no longer irradiated in directions other than the target direction at a high level. Therefore, this embodiment can suppress the reduction of processing accuracy.

[0019] A method for manufacturing an optical coupler according to one embodiment of the present invention includes:

[0020] A preparation step of preparing a light-transmitting substrate having a first main surface and a second main surface arranged in a first direction, wherein the light-transmitting substrate includes a third filler;

[0021] A first coating step of coating a first photosensitive glass paste on the first main surface;

[0022] A masking step of disposing a grayscale mask formed in a binary mode on the second main surface;

[0023] An exposure step of irradiating ultraviolet rays to the second main surface to expose the first photosensitive glass paste;

[0024] a developing step of removing the grayscale mask from the second main surface and developing the first photosensitive glass paste; and

[0025] a curing step of removing the light-transmitting substrate from the developed first photosensitive glass paste and curing the first photosensitive glass paste;

[0026] The longest length of the third filler is longer than the wavelength of the ultraviolet rays.

[0027] When the longest length of the third filler is longer than the wavelength of the ultraviolet light, the ultraviolet light diffracted by the grayscale mask is scattered by the third filler. As a result, the diffracted light is no longer irradiated in directions other than the target direction at a high level. Therefore, this embodiment can also suppress the reduction of processing accuracy.

[0028] An optical coupler according to one embodiment of the present invention includes a first photosensitive glass paste including a first filler, wherein:

[0029] The longest length of the first filler is longer than the wavelength of ultraviolet rays irradiated onto the grayscale mask formed in a binary pattern.

[0030] An optical coupler according to one embodiment of the present invention includes:

[0031] a first glass portion including a first glass and a first filler mixed in the first glass; and

[0032] The second glass portion includes at least a second glass and is connected to the first glass portion.

[0033] The second glass portion includes a second filler mixed in the second glass, and a content rate of the second filler included in the second glass portion is lower than a content rate of the first filler included in the first glass portion.

[0034] Alternatively, the second glass portion does not include the second filler.

[0035] In this embodiment, although there is no filler in the second glass portion, or the filler content is lower than that of the first glass portion, if ultraviolet rays are irradiated from the first glass portion, the diffracted light generated during manufacturing is diffused by the first filler of the first glass portion having a relatively high content. As a result, the diffracted light is no longer irradiated in directions other than the target direction at a high level. Therefore, this embodiment can also suppress the reduction of processing accuracy.

[0036] An optical coupler according to one embodiment of the present invention includes:

[0037] Glass section 1; and

[0038] a transmission portion connected to the first glass portion,

[0039] The first glass portion includes glass and a first filler mixed in the glass.

[0040] The permeable portion includes a medium and a second filler mixed in the medium.

[0041] The longest length of the second filler is different from the longest length of the first filler.

[0042] In this embodiment, the ultraviolet rays are irradiated to the first glass portion or the transmission portion having the longest filler among the first glass portion or the transmission portion, so that the diffracted light is diffused. As a result, the diffracted light is no longer irradiated to directions other than the target direction at a high level. Therefore, this embodiment can also suppress the reduction of processing accuracy.

[0043] Effects of the Invention

[0044] According to the method for manufacturing a photocoupler, the photocoupler, the photoelectric conversion circuit module, and the optical transceiver according to the present invention, it is possible to suppress a decrease in processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a perspective view of the optical coupler 1 .

[0046] Figure 2 It is a cross-sectional view of the optical coupler 1 and the optical fiber 5 .

[0047] Figure 3 It is a plan view of the optical coupler 1 as viewed in the first direction DIR1.

[0048] Figure 4 1 is a flowchart showing a method for manufacturing the photocoupler 1 .

[0049] Figure 5 It is a cross-sectional view of the photocoupler 1 during manufacturing.

[0050] Figure 6 is a diagram showing a pixel 15 of the grayscale mask 10 .

[0051] Figure 7 1 is a diagram showing a pattern in which the pixels 15 of the grayscale mask 10 are arranged in the order of aperture ratio.

[0052] Figure 8 This is an example of a grayscale mask 10 corresponding to the optical coupler 1 .

[0053] Fig. 9 This is a light intensity distribution of a comparative example in the exposure process.

[0054] Fig.10 This is the light intensity distribution of the first embodiment in the exposure process.

[0055] Fig.11 It is a perspective view of the light-transmitting substrate 11 .

[0056] Fig.12 It is a cross-sectional view of the optical coupler 1 b and the optical fiber 5 .

[0057] Fig.13 1 is a flowchart showing a method for manufacturing the photocoupler 1 b .

[0058] Fig.14 It is a cross-sectional view of the optical coupler 1b during manufacturing.

[0059] Fig.15 It is a cross-sectional view of the optical coupler 1 c and the optical fiber 5 .

[0060] Fig.16 It is a cross-sectional view of the optical coupler 1c during manufacturing.

[0061] Fig.17 It is a cross-sectional view of the optical coupler 1d and the optical fiber 5.

[0062] Fig.18 It is a perspective view of the photoelectric conversion circuit module 50 and the optical fiber 5 .

[0063] Fig.19 It is a cross-sectional view taken along the line AA of the photoelectric conversion circuit module 50 and the optical fiber 5 .

[0064] Fig. 20 It is a perspective view of the photoelectric conversion circuit module 50 a and the optical fiber 5 .

[0065] Fig.21 It is a perspective view of the optical transceiver 100 and the optical fiber 5 . DETAILED DESCRIPTION

[0066] [First embodiment]

[0067] [Structure of Photocoupler 1]

[0068] Hereinafter, a photocoupler 1 according to a first embodiment of the present invention will be described with reference to the drawings. Figure 1 is a perspective view of the optical coupler 1. Figure 1 In FIG. 1 , only representative first fillers P1 among the plurality of first fillers P1 are denoted by reference symbols. Figure 2 is a cross-sectional view of the optical coupler 1 and the optical fiber 5. Figure 2 In the figure, the second side wall portion 22 and the third side wall portion 23 are omitted. Figure 3 It is a plan view of the optical coupler 1 as viewed in the first direction DIR1.

[0069] In this specification, directions are defined as follows. Figure 1 As shown in the figure, the direction in which the bottom 24 and the reflecting part 3 are arranged in sequence is defined as the first direction DIR1. The direction in which the reflecting part 3 and the optical fiber fixing part 4 are arranged in sequence is defined as the second direction DIR2. The direction in which the second side wall part 22 and the third side wall part 23 are arranged in sequence is defined as the third direction DIR3. The first direction DIR1, the second direction DIR2 and the third direction DIR3 are orthogonal to each other. However, the first direction DIR1, the second direction DIR2 and the third direction DIR3 in this specification are directions defined for the convenience of explanation, and may not be consistent with the first direction DIR1, the second direction DIR2 and the third direction DIR3 when the optical coupler 1 is used.

[0070] The optical coupler 1 is a device for changing the traveling direction of light emitted from a photoelectric conversion circuit or the like and emitting it to an optical fiber, or changing the traveling direction of light emitted from an optical fiber and emitting it to a photoelectric conversion circuit or the like. In this embodiment, the case where the optical coupler 1 changes the traveling direction of light L emitted from a photoelectric conversion circuit or the like from a first direction DIR1 to a second direction DIR2 and emits it to an optical fiber 5 is described. Figure 2As shown, the optical coupler 1 has an incident surface S11 for incident light L in the first direction DIR1 and an exit surface S12 for emitting light L in the second direction DIR2. In addition, when the optical coupler 1 changes the traveling direction of the light L emitted from the optical fiber 5 from the opposite direction of the second direction DIR2 to the opposite direction of the first direction DIR1 and emits it to a photoelectric conversion circuit or the like, the incident surface and the exit surface may be swapped. In addition, the optical coupler 1 is an example of the "optical coupler" of the present invention. The "optical coupler" of the present invention may also be a focusing lens or a microlens array, etc. The structure of the optical coupler 1 is described in detail below.

[0071] like Figure 1 As shown, the optical coupler 1 includes a holding portion 2, a reflecting portion 3, and an optical fiber fixing portion 4. The optical coupler 1 is integrally formed of glass containing a filler. In addition, the optical coupler 1 is a single component. Here, the so-called single component refers to a component having a structure that cannot be separated without breaking it. Therefore, for example, a component in which two resin sheets are fixed by screws is not a single component. In addition, the optical coupler 1 may not be integrally formed of glass containing a filler. In addition, the optical coupler 1 may not be a single component.

[0072] The optical coupler 1 is integrally formed of a material including glass M1 and a plurality of first fillers P1 mixed in the glass M1. Glass is amorphous and is a material that exhibits a glass transition phenomenon. Examples of glass include simple oxide glasses such as SiO2, B2O3, P2O5, GeO2, and AS3O3; silicate glasses such as Li2O-SiO2, Na2O-SiO2, and K2O-SiO2; aluminosilicate glasses such as Na2O-Al2O3-SiO2 and CaO-Al2O3-SiO2; borates such as Li2O-B2O3 and Na2O-B2O3; aluminum borates such as CaO-Al2O3-B2O3; and borosilicate glasses such as Na2O-Al2O3-B2O3-SiO2.

[0073] The plurality of first fillers P1 are metal oxide particles such as crystalline silica, amorphous silica, alumina, magnesium oxide, titanium oxide, barium titanate, calcium titanate, or organic particles such as graphite. The first filler P1 includes a filler having a non-spherical shape. The plurality of first fillers P1 are dispersed throughout the glass M1. In addition, the first filler P1 may not include a filler having a non-spherical shape. In addition, the plurality of first fillers P1 may be uniformly dispersed throughout the glass M1, or may be unevenly dispersed throughout the glass M1.

[0074] The longest length of each of the plurality of first fillers P1 is set to r1. In addition, when the plurality of first fillers P1 each has a spherical shape, the longest length r1 of each of the plurality of first fillers P1 is the diameter of the sphere. In addition, when the plurality of first fillers P1 each has an ellipsoidal shape, the longest length r1 of each of the plurality of first fillers P1 is the length in the long axis direction of the ellipsoidal sphere. In this way, the longest length r1 of each of the plurality of first fillers P1 is the length in the length direction of the longest part of each of the plurality of first fillers P1. In the present embodiment, the maximum value of the longest length r1 of each of the plurality of first fillers P1 is longer than the wavelength λ of the ultraviolet UV described later. That is, there is a first filler P1 having a longest length r1 that is longer than the wavelength λ of the ultraviolet UV.

[0075] The holding part 2 holds the reflecting part 3 and the optical fiber fixing part 4, respectively. The holding part 2 is connected to the reflecting part 3 and the optical fiber fixing part 4, respectively. The holding part 2 includes a first side wall part 21, a second side wall part 22, a third side wall part 23, and a bottom part 24. In addition, the holding part 2 may not include each of the first side wall part 21, the second side wall part 22, and the third side wall part 23.

[0076] The first side wall portion 21 is connected to the second side wall portion 22, the third side wall portion 23 and the bottom portion 24, respectively. In more detail, the first side wall portion 21 has a shape extending in the third direction DIR3. In the present embodiment, the first side wall portion 21 has a plate shape. The end surface of the first side wall portion 21 in the third direction DIR3 is connected to the third side wall portion 23. The end surface of the first side wall portion 21 in the opposite direction to the third direction DIR3 is connected to the second side wall portion 22. The end surface of the first side wall portion 21 in the opposite direction to the first direction DIR1 is connected to the bottom portion 24. In addition, the first side wall portion 21 may not have a plate shape.

[0077] The second side wall portion 22 is connected to the first side wall portion 21, the bottom portion 24, the reflective portion 3, and the optical fiber fixing portion 4, respectively. In more detail, the second side wall portion 22 has a shape extending in the second direction DIR2. In the present embodiment, the second side wall portion 22 has a plate shape. Parts of the end surface of the second side wall portion 22 in the third direction DIR3 are connected to the end surface of the first side wall portion 21 in the opposite direction to the third direction DIR3, the reflective portion 3, and the optical fiber fixing portion 4, respectively. The end surface of the second side wall portion 22 in the opposite direction to the first direction DIR1 is connected to the bottom portion 24. In addition, the second side wall portion 22 may not have a plate shape.

[0078] The third side wall portion 23 is connected to the first side wall portion 21, the bottom portion 24, the reflective portion 3, and the optical fiber fixing portion 4, respectively. In more detail, the third side wall portion 23 has a shape extending in the second direction DIR2. In the present embodiment, the third side wall portion 23 has a plate shape. A portion of the end surface of the third side wall portion 23 in the direction opposite to the third direction DIR3 is connected to the end surface of the first side wall portion 21 in the third direction DIR3, the reflective portion 3, and the optical fiber fixing portion 4, respectively. The end surface of the third side wall portion 23 in the direction opposite to the first direction DIR1 is connected to the bottom portion 24. In addition, the third side wall portion 23 may not have a plate shape.

[0079] The bottom portion 24 is connected to the first side wall portion 21, the second side wall portion 22, the third side wall portion 23, the reflective portion 3, and the optical fiber fixing portion 4, respectively. In more detail, the bottom portion 24 has a plate shape. In the present embodiment, the bottom portion 24 has a rectangular shape when viewed in the first direction DIR1. A portion of the end surface of the bottom portion 24 in the first direction DIR1 is connected to the end surface of the first side wall portion 21 in the direction opposite to the first direction DIR1, the end surface of the second side wall portion 22 in the direction opposite to the first direction DIR1, the end surface of the third side wall portion 23 in the direction opposite to the first direction DIR1, the reflective portion 3, and the optical fiber fixing portion 4, respectively. In addition, the bottom portion 24 may not have a rectangular shape when viewed in the first direction DIR1.

[0080] like Figure 2 As shown, the light L enters the optical coupler 1 from the end surface S1 in the direction opposite to the first direction DIR1 of the bottom 24. Therefore, the end surface S1 in the direction opposite to the first direction DIR1 of the bottom 24 includes the incident surface S11 of the optical coupler 1. The light L that enters the bottom 24 from the end surface S1 in the direction opposite to the first direction DIR1 of the bottom 24 passes through the inside of the bottom 24 and enters the reflecting portion 3.

[0081] Here, if Figure 3 As shown, in the end surface S1 in the direction opposite to the first direction DIR1 of the bottom 24, the area overlapping with the reflecting portion 3 as viewed in the first direction DIR1 is defined as area A1. In addition, in the end surface S1 in the direction opposite to the first direction DIR1 of the bottom 24, the area not overlapping with the reflecting portion 3 as viewed in the first direction DIR1 is defined as area A2. The end surface S1 in the direction opposite to the first direction DIR1 of the bottom 24 includes both the area A1 and the area A2. The light L enters the optical coupler 1 from the area A1 of the bottom 24. Therefore, the area A1 is the incident surface S11. The area A2 is the mounting surface S21 for mounting the optical coupler 1 on a substrate when the optical coupler 1 is assembled in a photoelectric conversion circuit module or the like. The end surface S1 in the direction opposite to the first direction DIR1 of the bottom 24 includes the incident surface S11 and the mounting surface S21. That is, the mounting surface S21 is in the same plane as the incident surface S11.

[0082] like Figure 1 As shown, the reflection part 3 is connected to the second side wall part 22, the third side wall part 23 and the bottom part 24 respectively. Figure 2 As shown, the reflecting unit 3 changes the traveling direction of the light L incident from the incident surface S11 from the first direction DIR1 to the second direction DIR2, and emits it to any one of the five optical fibers 5. The reflecting unit 3 includes a prism unit 31 and five focusing lens units 32. In addition, the number of the focusing lens units 32 is not limited to five. In addition, the reflecting unit 3 may not include the focusing lens unit 32.

[0083] The prism portion 31 is connected to the second side wall portion 22, the third side wall portion 23 and the bottom portion 24, respectively. In more detail, in the present embodiment, the prism portion 31 has a right-angled isosceles triangular prism shape extending in the third direction DIR3. The prism portion 31 has a prism portion incident surface S2, a prism portion reflecting surface S3, a prism portion emitting surface S4, an end surface in the third direction DIR3, and an end surface in the opposite direction of the third direction DIR3. The end surface in the third direction DIR3 of the prism portion 31 is connected to the third side wall portion 23. The end surface in the opposite direction of the third direction DIR3 of the prism portion 31 is connected to the second side wall portion 22. In addition, the prism portion 31 may not have a right-angled isosceles triangular prism shape.

[0084] The prism portion incident surface S2 is an end surface in the opposite direction to the first direction DIR1 of the prism portion 31. The prism portion incident surface S2 is connected to the bottom 24. The light L that has passed through the inside of the bottom 24 is incident on the prism portion 31 from the prism portion incident surface S2. The light L that is incident on the prism portion 31 from the prism portion incident surface S2 passes through the inside of the prism portion 31.

[0085] When viewed in the third direction DIR3, the prism portion reflecting surface S3 forms an angle of 45 degrees with the prism portion incident surface S2 and the prism portion emitting surface S4. The end of the prism portion reflecting surface S3 in the first direction DIR1 is located closer to the second direction DIR2 than the end of the prism portion reflecting surface S3 in the opposite direction to the first direction DIR1. The prism portion reflecting surface S3 reflects the light L that has passed through the interior of the prism portion 31. Thus, the prism portion reflecting surface S3 changes the traveling direction of the light L from the first direction DIR1 to the second direction DIR2.

[0086] Five condensing lens sections 32 are provided on the prism section reflection surface S3. The five condensing lens sections 32 are arranged in the third direction DIR3. The surface of the condensing lens section 32 is aspherical. The condensing lens section 32 condenses and reflects the light L that passes through the inside of the prism section 31 and whose vector of the traveling direction includes the component of the first direction DIR1. Thus, the condensing lens section 32 changes the traveling direction of the light L from the direction including the component of the first direction DIR1 to the second direction DIR2.

[0087] The prism portion emission surface S4 is an end surface of the prism portion 31 in the first direction DIR1. The prism portion emission surface S4 is orthogonal to the prism portion incident surface S2. The prism portion emission surface S4 emits the light L that is reflected by the prism portion reflection surface S3 or the condenser lens portion 32 and passes through the inside of the prism portion 31. The light L emitted from the prism portion emission surface S4 travels in the first direction DIR1. The prism portion emission surface S4 is the emission surface S12 of the optical coupler 1.

[0088] The optical fiber fixing portion 4 fixes the five optical fibers 5, respectively. The optical fiber fixing portion 4 is connected to the second side wall portion 22, the third side wall portion 23, and the bottom portion 24, respectively. More specifically, the optical fiber fixing portion 4 has a plate shape extending in the third direction DIR3. In the present embodiment, the end surface of the optical fiber fixing portion 4 in the third direction DIR3 is connected to the third side wall portion 23. The end surface of the optical fiber fixing portion 4 in the opposite direction to the third direction DIR3 is connected to the second side wall portion 22. The end surface of the optical fiber fixing portion 4 in the opposite direction to the first direction DIR1 is connected to the bottom portion 24.

[0089] like Figure 1 As shown in FIG. 1 , the end surface of the optical fiber fixing portion 4 in the first direction DIR1 is provided with five grooves G having a V-shape when viewed in the second direction DIR2. The five grooves G each have a shape extending in the second direction DIR2. The five grooves G are arranged in the third direction DIR3. Figure 2 As shown, each of the five optical fibers 5 is fixed to the five grooves G. The five optical fibers 5 are arranged in the third direction DIR3. When viewed in the first direction DIR1, each of the five optical fibers 5 and the five focusing lens units 32 are arranged in the second direction DIR2. In addition, the end surface of the optical fiber fixing unit 4 in the first direction DIR1 may not be provided with the grooves G. In addition, when viewed in the second direction DIR2, each of the five grooves G may have a U-shape. In addition, the number of the grooves G is not limited to five.

[0090] The five optical fibers 5 each have a shape extending in the second direction DIR2. The end faces of the five optical fibers 5 in the direction opposite to the second direction DIR2 face the direction opposite to the second direction DIR2. The end faces of the five optical fibers 5 in the direction opposite to the second direction DIR2 face the prism portion emission surface S4 with a gap therebetween. Thus, the light L emitted from the prism portion emission surface S4 is incident on any one of the five optical fibers 5.

[0091] [Method of Manufacturing Optical Coupler 1]

[0092] Next, a method for manufacturing the photocoupler 1 will be described with reference to the drawings. Figure 4 1 is a flowchart showing a method for manufacturing the photocoupler 1 . Figure 5 is a cross-sectional view of the optical coupler 1 during manufacture. Figure 5 In the figure, the second side wall portion 22 and the third side wall portion 23 are omitted. Figure 6 is a diagram showing a pixel 15 of the grayscale mask 10 . Figure 7 1 is a diagram showing a pattern in which the pixels 15 of the grayscale mask 10 are arranged in the order of aperture ratio. Figure 8 This is an example of a grayscale mask 10 corresponding to the optical coupler 1 .

[0093] First, if Figure 5 As shown, a light-transmitting substrate 11 having a first main surface SU11 and a second main surface SU12 arranged in a first direction DIR1 is prepared (preparation step, Figure 4 : Step ST1). The first main surface SU11 is located closer to the second main surface SU12 in the first direction DIR1. The light-transmitting substrate 11 has a plate shape.

[0094] Next, the first photosensitive glass paste 12 is applied to the first main surface SU11 of the light-transmitting substrate 11 (first application step). Figure 4 :Step ST2). In the present embodiment, the first photosensitive glass paste 12 is a negative type. In the development process described later, the solubility of the exposed portion in the developer is reduced. As a result, the exposed portion of the first photosensitive glass paste 12 remains. In addition, the first photosensitive glass paste 12 may also be a positive type. In this case, in the development process described later, the solubility of the exposed portion in the developer is increased. As a result, the unexposed portion of the first photosensitive glass paste 12 remains. In addition, the first photosensitive glass paste 12 contains glass M1 and a plurality of first fillers P1 mixed in the glass M1. In addition to the glass M1 and the plurality of first fillers P1 mixed in the glass M1, the first photosensitive glass paste 12 may also contain additives such as a dispersant and a light absorber.

[0095] Next, a grayscale mask 10 is disposed on the second main surface SU12 of the light-transmitting substrate 11 (masking step, Figure 4 : Step ST3). The grayscale mask 10 is formed in a binary pattern. The grayscale mask 10 adjusts light transmittance by controlling the aperture ratio. The grayscale mask 10 will be described in detail below.

[0096] like Figure 6 As shown, the grayscale mask 10 has a structure in which a plurality of pixels 15 are arranged adjacent to each other. The pixel 15 has a unit area 16 and a runner part 17. When viewed in the first direction DIR1, the unit area 16 is square-shaped. Furthermore, the unit area 16 is divided into four square-shaped parts A11, A12, A21, and A22. When viewed in the first direction DIR1, the runner part 17 is arranged around the unit area 16. The runner part 17 is a light-shielding area b that is not transparent.

[0097] The unit area 16 is composed of an open (transmissive) light-transmitting area a and an unopened (opaque) light-shielding area b. Moreover, regarding the unit area 16, the aperture ratio (light transmittance) in the unit area 16 changes by changing the area ratio of the light-transmitting area a to the light-shielding area b.

[0098] For example, when all four square-shaped portions A11, A12, A21, and A22 are open, the aperture ratio of the unit area 16 is 100%. In addition, when all two square-shaped portions A12 and A21 are open and none of the two square-shaped portions A11 and A22 are open, the area ratio of the light-transmitting region a to the light-shielding region b is 1:1, and the aperture ratio (light transmittance) in the unit area 16 is 50%. In addition, when none of the four square-shaped portions A11, A12, A21, and A22 are open, the aperture ratio of the unit area 16 is 0%.

[0099] like Figure 7 As shown in FIG. 1 , if the unit areas 16 with an aperture ratio of 0% to 100% in the grayscale mask 10 are arranged in sequence in the second direction DIR2, the pattern of the grayscale mask 10 becomes a gradient. Figure 7 In the embodiment, the unit areas 16 with aperture ratios differing by 10% are arranged in sequence, but for example, the resolution of the aperture ratio can be improved by arranging the unit areas 16 with aperture ratios differing by 0.1% in sequence, and the continuity of the light transmittance can be maintained. In this way, the grayscale mask 10 adjusts the light transmittance by controlling the aperture ratio.

[0100] like Figure 8 As shown, the optical coupler 1 can be manufactured using the grayscale mask 10 by increasing the aperture ratio of the portion of the grayscale mask 10 corresponding to the first side wall portion 21 , the second side wall portion 22 , and the third side wall portion 23 and reducing the aperture ratio of the portion of the grayscale mask 10 corresponding to the groove G.

[0101] Then, if Figure 5 As shown, ultraviolet light UV is irradiated onto the second main surface SU12 of the light-transmitting substrate 11 to expose the first photosensitive glass paste 12 (exposure step, Figure 4 : Step ST4). The wavelength λ of the ultraviolet UV is longer than 10 nm and shorter than 380 nm. The first photosensitive glass paste 12 is exposed to light by the exposure process. In this embodiment, as described above, the maximum value of the longest length r1 of each of the plurality of first fillers P1 is longer than the wavelength λ of the ultraviolet UV.

[0102] Next, the grayscale mask 10 is removed from the second main surface SU12 of the light-transmitting substrate 11, and the first photosensitive glass paste 12 is developed (development step, Figure 4: Step ST5). More specifically, the first photosensitive glass paste 12 and the light-transmitting substrate 11 are immersed in a developer. Through the development process, the exposed portion of the first photosensitive glass paste 12 remains, and the unexposed portion is removed. After the development, the first photosensitive glass paste 12 and the light-transmitting substrate 11 are cleaned and dried.

[0103] Finally, the light-transmitting substrate 11 is removed from the developed first photosensitive glass paste 12, and the first photosensitive glass paste 12 is cured (curing step). Figure 4 : Step ST6). More specifically, the first photosensitive glass paste 12 is fired to solidify the first photosensitive glass paste 12. After the above steps, the optical coupler 1 is completed. Figure 5 As shown, grayscale masks 10 corresponding to the plurality of optical couplers 1 may be arranged on the second main surface SU12 of the light-transmitting substrate 11, and after the first photosensitive glass paste 12 is cured, the cured first photosensitive glass paste 12 may be cut, thereby completing the plurality of optical couplers 1.

[0104] [Effect]

[0105] According to the method for manufacturing the optical coupler 1, it is possible to suppress a decrease in processing accuracy. As a comparative example, a method for manufacturing an optical coupler that does not include a filler will be described with reference to the drawings. Fig. 9 This is a light intensity distribution of a comparative example in the exposure process. Fig.10 is the light intensity distribution of the first embodiment in the exposure process. Fig. 9 as well as Fig.10 In the embodiment, the ultraviolet light UV is laser light. In addition, the beam diameter of the ultraviolet light UV is sufficiently small compared with the light transmission area a.

[0106] In the exposure process, the ultraviolet light UV is diffracted by the periodic structure of the light-transmitting region a and the light-shielding region b of the grayscale mask 10. In the case where the first photosensitive glass paste 12 does not contain a filler, as in Fig. 9 As shown, high-level light is also distributed outside the position x1 in the second direction DIR2 of the ultraviolet UV. Therefore, the portion outside the position x1 in the first photosensitive glass paste 12 is also exposed to high-level ultraviolet UV. In this embodiment, the first photosensitive glass paste 12 is a negative type. Therefore, in the development process, the portion outside the position x1 in the first photosensitive glass paste 12 also becomes easy to remain. In this way, the light distributed outside the position x1 becomes a cause of reduced processing accuracy.

[0107] Thus, according to the manufacturing method of the optical coupler 1, the first photosensitive glass paste 12 includes the first filler P1. The longest length r1 of the first filler P1 is longer than the wavelength λ of the ultraviolet light UV. Therefore, the ultraviolet light UV diffracted by the periodic structure of the light-transmitting region a and the light-shielding region b of the grayscale mask 10 is scattered by the first filler P1. As a result, the light intensity distribution of the ultraviolet light UV becomes a normal distribution with the strongest intensity at the position x1, as shown in FIG. Fig.10 As shown in FIG. 1 , the light intensity I(x) distributed outside the position x1 is smaller than that of the comparative example, and high-level ultraviolet light UV is no longer irradiated outside the position x1. Therefore, in the development process, the portion outside the position x1 of the first photosensitive glass paste 12 becomes less likely to remain. As a result, according to the manufacturing method of the optical coupler 1, it is possible to suppress the reduction of processing accuracy.

[0108] In addition, when the longest length r1 of the first filler P1 is less than the wavelength λ of the ultraviolet UV, the scattering of the ultraviolet UV is suppressed. Therefore, when using the grayscale mask 10 formed in a binary pattern, the longest length r1 of the first filler P1 is longer than the wavelength λ of the ultraviolet UV, thereby generating scattering of the ultraviolet UV, and the light intensity I(x) of the ultraviolet UV distributed outside the position x1 in the second direction DIR2 can be reduced.

[0109] Furthermore, according to the method for manufacturing the optical coupler 1, the content of the first filler P1 included in the first photosensitive glass paste 12 can be reduced. More specifically, the first filler P1 includes a filler having a non-spherical shape. Thus, compared with the case where the first filler P1 includes only a filler having a spherical shape, it is possible to further scatter the ultraviolet light UV. As a result, according to the method for manufacturing the optical coupler 1, the content of the first filler P1 included in the first photosensitive glass paste 12 can be reduced.

[0110] [First Modification]

[0111] [Structure of Photocoupler 1a]

[0112] Hereinafter, an optical coupler 1a according to a first modification of the present invention will be described. In addition, regarding the structure of the optical coupler 1a according to the first modification, only the parts that are different from the structure of the optical coupler 1 according to the first embodiment will be described, and the rest will be omitted.

[0113] In this modification, the longest length r1 of each of the plurality of first fillers P1 is smaller than the wavelength λ of the ultraviolet UV. In addition, in this modification, the longest length r1 of each of the plurality of first fillers P1 may be greater than the wavelength λ of the ultraviolet UV. In addition, in this modification, the optical coupler 1a may not include the first filler P1. In addition, in this modification, the optical coupler 1a corresponds to the "first glass portion" of the present invention.

[0114] [Method of Manufacturing Optical Coupler 1a]

[0115] Next, a method for manufacturing the optical coupler 1 a according to a first modified example of the present invention will be described with reference to the drawings. Fig.11 is a three-dimensional diagram of the light-transmitting substrate 11. Fig.11 In the above description, only the representative third fillers P3 among the plurality of third fillers P3 are given reference numerals. In addition, regarding the method for manufacturing the optical coupler 1a according to the first modification, only the parts that are different from the method for manufacturing the optical coupler 1 according to the first embodiment will be described, and the rest will be omitted.

[0116] The light-transmitting substrate 11 includes a medium M2 and a plurality of third fillers P3 mixed in the medium M2. The medium M2 is, for example, a resin. Alternatively, the medium M2 may be glass or the like.

[0117] The plurality of third fillers P3 are metal oxide particles such as crystalline silica, amorphous silica, alumina, magnesium oxide, titanium oxide, barium titanate, calcium titanate, or organic particles such as graphite. The third filler P3 includes a filler having a non-spherical shape. The plurality of third fillers P3 are dispersed throughout the medium M2. In addition, the third filler P3 may not include a filler having a non-spherical shape. In addition, the plurality of third fillers P3 may be uniformly dispersed throughout the medium M2, or may be unevenly dispersed throughout the medium M2.

[0118] The longest length of each of the plurality of third fillers P3 is set to r3. In addition, when the plurality of third fillers P3 each has a spherical shape, the longest length r3 of each of the plurality of third fillers P3 is the diameter of the sphere. In addition, when the plurality of third fillers P3 each has an ellipsoidal shape, the longest length r3 of each of the plurality of third fillers P3 is the length in the long axis direction of the ellipsoidal sphere. Like this, the longest length r3 of each of the plurality of third fillers P3 is the length in the length direction of the longest part of each of the plurality of third fillers P3. In this modification, the maximum value of the longest length r3 of each of the plurality of third fillers P3 is longer than the wavelength λ of the ultraviolet light UV. Therefore, the maximum value of the longest length r3 of each of the plurality of third fillers P3 is longer than the maximum value of the longest length r1 of each of the plurality of first fillers P1. There is a third filler P3 having a longest length r3 that is longer than the maximum value of the longest length r1 of the first filler P1.

[0119] In this modification, in the curing step, the light-transmitting substrate 11 may not be removed from the first photosensitive glass paste 12 after development. That is, the light-transmitting substrate 11 may be connected to the optical coupler 1a. In this case, the light-transmitting substrate 11 corresponds to the "transmitting portion" of the present invention.

[0120] In the manufacturing method of the optical coupler 1a as described above, the same effect as the manufacturing method of the optical coupler 1 is achieved. In addition, according to the manufacturing method of the optical coupler 1a, the content of the first filler P1 contained in the first photosensitive glass paste 12 can be reduced. In more detail, the longest length r3 of the third filler P3 contained in the translucent substrate 11 is longer than the wavelength λ of the ultraviolet UV. Therefore, the ultraviolet UV diffracted by the periodic structure of the light-transmitting area a and the light-shielding area b of the grayscale mask 10 is scattered by the third filler P3 contained in the translucent substrate 11. As a result, the light intensity distribution of the ultraviolet UV becomes a normal distribution that is strongest at the position x1, and the light intensity I (x) distributed outside the position x1 becomes smaller than that of the comparative example, and high-level ultraviolet UV is no longer irradiated outside the position x1. Therefore, in the development process, the portion outside the position x1 in the first photosensitive glass paste 12 becomes less likely to remain. This can suppress reduction in processing accuracy even when the content of the first filler P1 included in the first photosensitive glass paste 12 is reduced. As a result, according to the method for manufacturing the photocoupler 1a, the content of the first filler P1 included in the first photosensitive glass paste 12 can be reduced.

[0121] Furthermore, according to the manufacturing method of the optical coupler 1a, the processing accuracy of the optical coupler 1a can be improved. More specifically, the third filler P3 includes a filler having a non-spherical shape. Thus, compared with the case where the third filler P3 includes only a filler having a spherical shape, it is possible to further scatter the ultraviolet light UV. Therefore, according to the manufacturing method of the optical coupler 1a, the content of the third filler P3 included in the light-transmitting substrate 11 can be reduced. As a result, according to the manufacturing method of the optical coupler 1a, the processing accuracy of the optical coupler 1a can be improved.

[0122] [Second Modification]

[0123] [Structure of Photocoupler 1b]

[0124] Hereinafter, an optical coupler 1 b according to a second modified example of the present invention will be described with reference to the drawings. Fig.12 is a cross-sectional view of the optical coupler 1b and the optical fiber 5. Fig.12 , the second side wall portion 22 and the third side wall portion 23 are omitted. In addition, regarding the structure of the optical coupler 1b according to the second modification, only the parts that are different from the structure of the optical coupler 1 according to the first embodiment will be described, and the rest will be omitted.

[0125] In this modification, the plurality of first fillers P1 are included only in the bottom 24, and no fillers are included in each of the first side wall portion 21, the second side wall portion 22, the third side wall portion 23, the reflective portion 3, and the optical fiber fixing portion 4. In addition, the plurality of first fillers P1 may be included only in the end surface S1 in the direction opposite to the first direction DIR1 of the bottom 24, and no fillers may be included except for the end surface S1 in the direction opposite to the first direction DIR1 of the bottom 24. In addition, in this modification, the bottom 24 corresponds to the "first glass portion" of the present invention. The first side wall portion 21, the second side wall portion 22, the third side wall portion 23, the reflective portion 3, and the optical fiber fixing portion 4 respectively correspond to the "second glass portion" or "transmitting portion" of the present invention. The "second glass portion" of the present invention contains at least glass.

[0126] [Method of Manufacturing Optical Coupler 1b]

[0127] Next, a method for manufacturing the optical coupler 1 b according to a second modified example of the present invention will be described with reference to the drawings. Fig.13 1 is a flowchart showing a method for manufacturing the photocoupler 1 b . Fig.14 is a cross-sectional view of the optical coupler 1b during manufacture. Fig.14 , the second side wall portion 22 and the third side wall portion 23 are omitted. In addition, regarding the method for manufacturing the optical coupler 1b according to the second modification, only the parts that are different from the method for manufacturing the optical coupler 1 according to the first embodiment will be described, and the rest will be omitted.

[0128] In this modification, after the first coating step, the second photosensitive glass paste 13 not containing a filler is coated on the first photosensitive glass paste 12 (the second coating step, Fig.13 :Step ST21). In this modification, the second photosensitive glass paste 13 is a negative type. In addition, when the first photosensitive glass paste 12 is a positive type, the second photosensitive glass paste 13 may also be a positive type. In addition, the second photosensitive glass paste 13 may also contain additives such as a dispersant and a light absorber in addition to glass. In addition, the second coating process may also be after the masking process. The second coating process only needs to be between the first coating process and the exposure process.

[0129] In the exposure step, ultraviolet light UV is irradiated onto the second main surface SU12 of the light-transmitting substrate 11 to expose the first photosensitive glass paste 12 and the second photosensitive glass paste 13 ( Fig.13 : Step ST4). Through the exposure process, the first photosensitive glass paste 12 and the second photosensitive glass paste 13 are exposed to light.

[0130] In the development step, the grayscale mask 10 is removed from the second main surface SU12 of the light-transmitting substrate 11, and the first photosensitive glass paste 12 and the second photosensitive glass paste 13 are developed ( Fig.13: Step ST5). In more detail, the first photosensitive glass paste 12, the second photosensitive glass paste 13, and the translucent substrate 11 are immersed in a developer. Through the development process, the exposed portions of the first photosensitive glass paste 12 and the second photosensitive glass paste 13 remain, and the unexposed portions are removed. After the development, the first photosensitive glass paste 12, the second photosensitive glass paste 13, and the translucent substrate 11 are cleaned and dried.

[0131] In the curing step, the light-transmitting substrate 11 is removed from the developed first photosensitive glass paste 12, and the first photosensitive glass paste 12 and the second photosensitive glass paste 13 are cured ( Fig.13 : Step ST6 ). More specifically, the first photosensitive glass paste 12 and the second photosensitive glass paste 13 are fired to solidify the first photosensitive glass paste 12 and the second photosensitive glass paste 13 .

[0132] In the manufacturing method of the optical coupler 1b as described above, the same effect as the manufacturing method of the optical coupler 1 is achieved. More specifically, in the exposure process, the ultraviolet light UV is irradiated to the second main surface SU12 of the translucent substrate 11. Therefore, the longest length r1 of the first filler P1 included in the first photosensitive glass paste 12 applied to the first main surface SU11 of the translucent substrate 11 is longer than the wavelength λ of the ultraviolet light UV, so that the ultraviolet light UV diffracted by the periodic structure of the light-transmitting area a and the light-shielding area b of the grayscale mask 10 is scattered by the first filler P1. As a result, the light intensity distribution of the ultraviolet light UV becomes a normal distribution that is strongest at the position x1, and the light intensity I (x) distributed outside the position x1 becomes smaller than that of the comparative example, and the high-level ultraviolet light UV is no longer irradiated outside the position x1. Therefore, in the development process, the portion outside the position x1 of the first photosensitive glass paste 12 and the second photosensitive glass paste 13 becomes less likely to remain. Therefore, even when the second photosensitive glass paste 13 applied to the first photosensitive glass paste 12 does not contain a filler, the same effects as those of the method for manufacturing the photocoupler 1 are achieved.

[0133] Furthermore, according to the method for manufacturing the optical coupler 1b, the second photosensitive glass paste 13 does not contain a filler. Therefore, according to the method for manufacturing the optical coupler 1b, the shape accuracy of the optical coupler 1b can be improved.

[0134] [Third Modification]

[0135] [Structure of Photocoupler 1c]

[0136] Next, an optical coupler 1c according to a third modified example of the present invention will be described. Fig.15 is a cross-sectional view of the optical coupler 1c and the optical fiber 5. Fig.15, the second side wall portion 22 and the third side wall portion 23 are omitted. In addition, regarding the structure of the optical coupler 1c according to the third modification, only the parts that are different from the structure of the optical coupler 1b according to the second modification are described, and the rest are omitted.

[0137] In this modification, the bottom 24 includes glass M1 and a plurality of first fillers P1 mixed in the glass M1. The first side wall portion 21, the second side wall portion 22, the third side wall portion 23, the reflector portion 3, and the optical fiber fixing portion 4 each include glass M1 and a plurality of second fillers P2 mixed in the glass M1. The content of the second filler P2 included in each of the first side wall portion 21, the second side wall portion 22, the third side wall portion 23, the reflector portion 3, and the optical fiber fixing portion 4 is lower than the content of the first filler P1 included in the bottom 24. In addition, the content of the second filler P2 included in the bottom 24 other than the end surface S1 in the direction opposite to the first direction DIR1 may be lower than the content of the first filler P1 included in the end surface S1 in the direction opposite to the first direction DIR1 of the bottom 24.

[0138] The plurality of second fillers P2 are metal oxide particles such as crystalline silica, amorphous silica, alumina, magnesium oxide, titanium oxide, barium titanate, calcium titanate, or organic particles such as graphite. The second filler P2 includes a filler having a non-spherical shape. The plurality of second fillers P2 are dispersed throughout the glass M1. In addition, the second filler P2 may not include a filler having a non-spherical shape. In addition, the plurality of second fillers P2 may be uniformly dispersed throughout the glass M1, or may be unevenly dispersed throughout the glass M1.

[0139] [Method for manufacturing optical coupler 1c]

[0140] Next, a method for manufacturing the optical coupler 1 c according to the third modified example of the present invention will be described with reference to the drawings. Fig.16 is a cross-sectional view of the optical coupler 1c during manufacturing. Fig.16 , the second side wall portion 22 and the third side wall portion 23 are omitted. In addition, regarding the method for manufacturing the optical coupler 1c according to the third modification, only the parts that are different from the method for manufacturing the optical coupler 1b according to the second modification are described, and the rest are omitted.

[0141] In this modification, after the first coating step, the second photosensitive glass paste 13 containing the second filler P2 is coated on the first photosensitive glass paste 12 (second coating step). The content of the second filler P2 contained in the second photosensitive glass paste 13 is lower than the content of the first filler P1 contained in the first photosensitive glass paste 12. In addition, the second coating step may be after the masking step. The second coating step only needs to be between the first coating step and the exposure step.

[0142] In the manufacturing method of the optical coupler 1c as described above, the same effect as the manufacturing method of the optical coupler 1b is achieved. More specifically, for the same reason as the manufacturing method of the optical coupler 1b, even when the content of the second filler P2 included in the second photosensitive glass paste 13 applied to the first photosensitive glass paste 12 is lower than the content of the first filler P1 included in the first photosensitive glass paste 12, the same effect as the manufacturing method of the optical coupler 1b is achieved.

[0143] Furthermore, according to the method for manufacturing the optical coupler 1c, the content of the second filler P2 included in the second photosensitive glass paste 13 is lower than the content of the first filler P1 included in the first photosensitive glass paste 12. Therefore, according to the method for manufacturing the optical coupler 1c, the shape accuracy of the optical coupler 1c can be improved.

[0144] [Fourth Modification]

[0145] [Structure of Optical Coupler 1d]

[0146] Hereinafter, an optical coupler 1d according to a fourth modified example of the present invention will be described with reference to the drawings. Fig.17 is a cross-sectional view of the optical coupler 1d and the optical fiber 5. Fig.17 , the second side wall portion 22 and the third side wall portion 23 are omitted. In addition, regarding the structure of the optical coupler 1d according to the fourth modification, only the parts that are different from the structure of the optical coupler 1c according to the third modification are described, and the rest are omitted.

[0147] The longest length of each of the plurality of second fillers P2 is set to r2. In addition, when the plurality of second fillers P2 each have a spherical shape, the longest length r2 of each of the plurality of second fillers P2 is the diameter of the sphere. In addition, when the plurality of second fillers P2 each have an ellipsoidal shape, the longest length r2 of each of the plurality of second fillers P2 is the length in the long axis direction of the ellipsoidal sphere. Like this, the longest length r2 of each of the plurality of second fillers P2 is the length in the length direction of the longest part of each of the plurality of second fillers P2. In this modification, the maximum value of the longest length r2 of each of the plurality of second fillers P2 is longer than 0 and is less than the wavelength λ of the ultraviolet UV. Therefore, the maximum value of the longest length r2 of each of the plurality of second fillers P2 is shorter than the maximum value of the longest length r1 of each of the plurality of first fillers P1. There is a first filler P1 having a longest length r1 that is longer than the maximum value of the longest length r2 of the second filler P2. The maximum value of the longest length r2 of each of the plurality of second fillers P2 is different from the maximum value of the longest length r1 of each of the plurality of first fillers P1.

[0148] [Method for manufacturing optical coupler 1d]

[0149] Hereinafter, an optical coupler 1d according to a fourth modification of the present invention will be described. In addition, regarding the method for manufacturing the optical coupler 1d according to the fourth modification, only the parts that are different from the method for manufacturing the optical coupler 1c according to the third modification will be described, and the rest will be omitted.

[0150] In the present modification, the maximum value of the longest length r2 of each of the plurality of second fillers P2 included in the second photosensitive glass paste 13 is longer than 0 and is equal to or less than the wavelength λ of the ultraviolet light UV.

[0151] In the manufacturing method of the optical coupler 1d as described above, the same effect as the manufacturing method of the optical coupler 1c is achieved. More specifically, for the same reason as the manufacturing method of the optical coupler 1c, even when the longest length r2 of the second filler P2 included in the second photosensitive glass paste 13 applied to the first photosensitive glass paste 12 is longer than 0 and is less than the wavelength λ of the ultraviolet light UV, the same effect as the manufacturing method of the optical coupler 1c is achieved.

[0152] Furthermore, according to the method for manufacturing the optical coupler 1d, the longest length r2 of the second filler P2 included in the second photosensitive glass paste 13 is longer than 0 and is equal to or shorter than the wavelength λ of the ultraviolet UV. Therefore, according to the method for manufacturing the optical coupler 1d, the processing accuracy of the optical coupler 1d can be improved.

[0153] [Fifth Modification]

[0154] [Configuration of Photoelectric Conversion Circuit Module 50]

[0155] Hereinafter, a photoelectric conversion circuit module 50 according to a fifth modification will be described with reference to the drawings. Fig.18 is a perspective view of the photoelectric conversion circuit module 50 and the optical fiber 5. Fig.18 In the figure, only representative optical couplers 1 , optical fibers 5 , and optical waveguides OW among the plurality of optical couplers 1 , the plurality of optical fibers 5 , and the plurality of optical waveguides OW are denoted by reference symbols. Fig.19 It is a cross-sectional view taken along the line AA of the photoelectric conversion circuit module 50 and the optical fiber 5 .

[0156] like Fig.18As shown, the photoelectric conversion circuit module 50 includes a plurality of optical couplers 1, a substrate 51, and a photoelectric conversion circuit 52. The plurality of optical couplers 1 and the photoelectric conversion circuit 52 are mounted on the substrate 51. When viewed in the first direction DIR1, the photoelectric conversion circuit 52 is arranged in the center of the substrate 51. When viewed in the first direction DIR1, the plurality of optical couplers 1 are arranged around the photoelectric conversion circuit 52. The plurality of optical fibers 5 are respectively fixed to the optical fiber fixing parts 4 of the plurality of optical couplers 1. In addition, the number of optical couplers 1 is not limited to a plurality, and may be one. In addition, when viewed in the first direction DIR1, the photoelectric conversion circuit 52 may not be arranged in the center of the substrate 51. In addition, when viewed in the first direction DIR1, the plurality of optical couplers 1 may not be arranged around the photoelectric conversion circuit 52. In addition, the photoelectric conversion circuit module 50 may also include an optical coupler 1a, an optical coupler 1b, an optical coupler 1c, or an optical coupler 1d instead of the optical coupler 1.

[0157] The substrate 51 has a plate shape having two main surfaces arranged in the first direction DIR1. Fig.19 As shown, an optical waveguide OW and a reflector M are provided inside the substrate 51. The optical waveguide OW is provided between the photoelectric conversion circuit 52 and each of the plurality of optical couplers 1. The reflector M is provided in the opposite direction of the first direction DIR1 from the reflection unit 3. The light L emitted from the photoelectric conversion circuit 52 passes through the optical waveguide OW.

[0158] The plurality of photocouplers 1 are mounted on the principal surface located in the first direction DIR1 among the two principal surfaces of the substrate 51. More specifically, the mounting surface S21 is mounted on the principal surface located in the first direction DIR1 among the two principal surfaces of the substrate 51.

[0159] The photoelectric conversion circuit 52 is mounted on the main surface located in the first direction DIR1 among the two main surfaces of the substrate 51. The photoelectric conversion circuit 52 converts an electrical signal into light incident on the optical coupler 1, or converts light emitted from the optical coupler 1 into an electrical signal. The case where the photoelectric conversion circuit 52 converts an electrical signal into light incident on the optical coupler 1 will be described.

[0160] The photoelectric conversion circuit 52 converts the electrical signal into light L that is incident on the plurality of optical couplers 1. The light L emitted from the photoelectric conversion circuit 52 travels along the second direction DIR2 in the optical waveguide OW. The light L traveling along the second direction DIR2 in the optical waveguide OW is reflected by the reflector M. As a result, the traveling direction of the light L is changed from the second direction DIR2 to the first direction DIR1. Thereafter, the light L is incident on the incident surface S11 of the optical coupler 1, passes through the optical coupler 1, changes the traveling direction from the first direction DIR1 to the second direction DIR2, and is emitted from the emission surface S12 of the optical coupler 1. As a result, the light L is incident on the five optical fibers 5, respectively.

[0161] The above-described photoelectric conversion circuit module 50 also produces the same effects as those of the photocoupler 1 .

[0162] [Sixth Modification]

[0163] [Configuration of Photoelectric Conversion Circuit Module 50a]

[0164] Hereinafter, a photoelectric conversion circuit module 50a according to a sixth modification will be described with reference to the drawings. Fig. 20 is a perspective view of the photoelectric conversion circuit module 50a and the optical fiber 5. Fig. 20 In the figure, only the representative optical couplers 1 and optical fibers 5 among the plurality of optical couplers 1 and the plurality of optical fibers 5 are marked with reference marks. In addition, regarding the photoelectric conversion circuit module 50a involved in the sixth modification, only the parts different from the photoelectric conversion circuit module 50 involved in the fifth modification are described, and the rest are omitted.

[0165] The photoelectric conversion circuit module 50a is different from the photoelectric conversion circuit module 50 in that the substrate 51 is a semiconductor substrate and the substrate 51 includes a plurality of light emitting portions 53. The number of the light emitting portions 53 is not limited to a plurality, and may be one.

[0166] The plurality of light emitting parts 53 are, for example, surface light emitting elements formed on the main surface located in the first direction DIR1 among the two main surfaces of the substrate 51. The plurality of light emitting parts 53 are, for example, VCSELs (Vertical Cavity Surface Emitting Lasers). The plurality of light emitting parts 53 emit light L based on the electrical signal generated by the photoelectric conversion circuit 52. The light L emitted by the plurality of light emitting parts 53 is incident on each of the plurality of optical fibers 5 via each of the plurality of optical couplers 1.

[0167] The above-described photoelectric conversion circuit module 50 a also produces the same effects as those of the photoelectric conversion circuit module 50 .

[0168] [Seventh Modification]

[0169] [Structure of the optical transceiver 100]

[0170] Hereinafter, the optical transceiver 100 will be described with reference to the drawings. Fig.21 1 is a perspective view of the optical transceiver 100 and the optical fiber 5. Fig.21 In FIG. 1 , only representative optical fibers 5 among the five optical fibers 5 are denoted by reference numerals. In addition, regarding the optical transceiver 100 according to the seventh modification, only the parts different from the photoelectric conversion circuit module 50a according to the sixth modification will be described, and the rest will be omitted.

[0171] The optical transceiver 100 is different from the photoelectric conversion circuit module 50 a in that the number of optical couplers 1 is one and the number of light emitting units 53 is one.

[0172] The light L emitted from the light emitting unit 53 enters each of the five optical fibers 5 via the optical coupler 1 , or the light L emitted from each of the five optical fibers 5 enters the photoelectric conversion circuit 52 via the optical coupler 1 .

[0173] The optical transceiver 100 described above also has the same effects as those of the photoelectric conversion circuit module 50 a.

[0174] [Other embodiments]

[0175] The optical coupler of the present invention is not limited to the optical coupler 1, the optical coupler 1a, the optical coupler 1b, the optical coupler 1c, and the optical coupler 1d, and can be modified within the scope of the gist thereof. In addition, the structures of the optical coupler 1, the optical coupler 1a, the optical coupler 1b, the optical coupler 1c, and the optical coupler 1d can be arbitrarily combined.

[0176] The photoelectric conversion circuit module according to the present invention is not limited to the photoelectric conversion circuit module 50 and the photoelectric conversion circuit module 50a, and can be modified within the scope of the gist thereof. In addition, the structures of the photoelectric conversion circuit module 50 and the photoelectric conversion circuit module 50a can be arbitrarily combined.

[0177] The optical transceiver according to the present invention is not limited to the optical transceiver 100 , and can be modified within the scope of the gist thereof.

[0178] The present invention has the following structure. (1)

[0180] A method for manufacturing an optical coupler, comprising:

[0181] A preparation step of preparing a light-transmitting substrate having a first main surface and a second main surface arranged in a first direction;

[0182] A first coating step of coating a first photosensitive glass paste containing a first filler on the first main surface;

[0183] A masking step of disposing a grayscale mask formed in a binary mode on the second main surface;

[0184] An exposure step of irradiating ultraviolet rays to the second main surface to expose the first photosensitive glass paste;

[0185] a developing step of removing the grayscale mask from the second main surface and developing the first photosensitive glass paste; and

[0186] a curing step of removing the light-transmitting substrate from the developed first photosensitive glass paste and curing the first photosensitive glass paste;

[0187] The longest length of the first filler is longer than the wavelength of the ultraviolet light. (2)

[0189] In the method for manufacturing an optical coupler described in (1),

[0190] Between the first coating step and the exposure step, a second coating step of coating a second photosensitive glass paste on the first photosensitive glass paste is included.

[0191] In the exposure step, the first photosensitive glass paste and the second photosensitive glass paste are exposed.

[0192] In the developing step, the first photosensitive glass paste and the second photosensitive glass paste are developed.

[0193] In the curing step, the first photosensitive glass paste and the second photosensitive glass paste are cured.

[0194] The second photosensitive glass paste includes a second filler, and a content rate of the second filler included in the second photosensitive glass paste is lower than a content rate of the first filler included in the first photosensitive glass paste.

[0195] Alternatively, the second photosensitive glass paste does not include the second filler. (3)

[0197] In the method for manufacturing an optical coupler described in (1),

[0198] Between the first coating step and the exposure step, a second coating step of coating a second photosensitive glass paste containing a second filler on the first photosensitive glass paste is included.

[0199] In the exposure step, the first photosensitive glass paste and the second photosensitive glass paste are exposed.

[0200] In the developing step, the first photosensitive glass paste and the second photosensitive glass paste are developed.

[0201] In the curing step, the first photosensitive glass paste and the second photosensitive glass paste are cured.

[0202] The longest length of the second filler is longer than 0 and is shorter than the wavelength of the ultraviolet rays. (4)

[0204] In the method for manufacturing an optical coupler according to any one of (1) to (3),

[0205] The first filler includes a filler having a non-spherical shape. (5)

[0207] A method for manufacturing an optical coupler, comprising:

[0208] A preparation step of preparing a light-transmitting substrate having a first main surface and a second main surface arranged in a first direction, wherein the light-transmitting substrate includes a third filler;

[0209] A first coating step of coating a first photosensitive glass paste on the first main surface;

[0210] A masking step of disposing a grayscale mask formed in a binary mode on the second main surface;

[0211] An exposure step of irradiating ultraviolet rays to the second main surface to expose the first photosensitive glass paste;

[0212] a developing step of removing the grayscale mask from the second main surface and developing the first photosensitive glass paste; and

[0213] a curing step of removing the light-transmitting substrate from the developed first photosensitive glass paste and curing the first photosensitive glass paste;

[0214] The longest length of the third filler is longer than the wavelength of the ultraviolet rays. (6)

[0216] In the method for manufacturing an optical coupler described in (5),

[0217] The third filler includes a filler having a non-spherical shape. (7)

[0219] An optical coupler includes a first photosensitive glass paste, wherein the first photosensitive glass paste includes a first filler, wherein:

[0220] The longest length of the first filler is longer than the wavelength of ultraviolet rays irradiated onto the grayscale mask formed in a binary pattern. (8)

[0222] An optical coupler comprising:

[0223] a first glass portion including a first glass and a first filler mixed in the first glass; and

[0224] The second glass portion includes at least a second glass and is connected to the first glass portion.

[0225] The second glass portion includes a second filler mixed in the second glass, and a content rate of the second filler included in the second glass portion is lower than a content rate of the first filler included in the first glass portion.

[0226] Alternatively, the second glass portion does not include the second filler. (9)

[0228] An optical coupler comprising:

[0229] Glass section 1; and

[0230] a transmission portion connected to the first glass portion,

[0231] The first glass portion includes glass and a first filler mixed in the glass.

[0232] The permeable portion includes a medium and a second filler mixed in the medium.

[0233] The longest length of the second filler is different from the longest length of the first filler. (10)

[0235] In the optical coupler described in (9),

[0236] The medium is glass. (11)

[0238] In the optical coupler described in any one of (7) to (10),

[0239] The first filler includes a filler having a non-spherical shape. (12)

[0241] In the optical coupler described in (9) or (10),

[0242] The transmissive portion is a light-transmissive substrate. (13)

[0244] In the optical coupler described in (12),

[0245] The second filler includes a filler having a non-spherical shape. (14)

[0247] A photoelectric conversion circuit module, comprising:

[0248] The optical coupler according to any one of (7) to (13);

[0249] substrate; and

[0250] A photoelectric conversion circuit is mounted on the substrate,

[0251] The photoelectric conversion circuit converts an electric signal into light incident on the photocoupler, or converts light emitted from the photocoupler into an electric signal. (15)

[0253] In the photoelectric conversion circuit module described in (14),

[0254] The substrate is a semiconductor substrate and includes a light emitting portion for emitting light.

[0255] The optical coupler is mounted on the substrate. (16)

[0257] An optical transceiver comprises the optical coupler described in any one of (7) to (13).

[0258] Description of Reference Numerals

[0259] 1, 1a, 1b, 1c, 1d: Optocoupler

[0260] 2: Maintaining part

[0261] 3: Reflection part

[0262] 4: Optical fiber fixing part

[0263] 5. Fiber Optic

[0264] 10: Grayscale mask

[0265] 11: Translucent substrate

[0266] 12: No. 1 photosensitive glass paste

[0267] 13: Second photosensitive glass paste

[0268] 15: Pixels

[0269] 16: Unit area

[0270] 17: Runner

[0271] 21: 1st side wall

[0272] 22: Second side wall

[0273] 23: The third side wall

[0274] 24: Bottom

[0275] 31: Prism Department

[0276] 32: Focusing lens

[0277] 50, 50a: Photoelectric conversion circuit module

[0278] 51: Substrate

[0279] 52: Photoelectric conversion circuit

[0280] 53: Light emitting part

[0281] 100: Optical transceiver

[0282] A1, A2: Area

[0283] A11, A12, A21, A22: Square shape

[0284] DIR1: Direction 1

[0285] DIR2: Direction 2

[0286] DIR3: 3rd direction

[0287] G: Slot

[0288] I: Light intensity

[0289] L: Light

[0290] M: Reflector

[0291] M1: Glass

[0292] M2: Medium

[0293] OW: Optical Waveguide

[0294] P1: First filler

[0295] P2: Second filler

[0296] P3: The third filler

[0297] S1: End face

[0298] S11: Incident surface

[0299] S12: Ejection surface

[0300] S2: Prism incident surface

[0301] S21: Mounting surface

[0302] S3: Prism reflection surface

[0303] S4: Prism exit surface

[0304] SU11: 1st main surface

[0305] SU12:Second main surface

[0306] UV: Ultraviolet

[0307] a: Light transmission area

[0308] b: Light shielding area.

Claims

1. A method for manufacturing an optical coupler, comprising: A preparation step of preparing a light-transmitting substrate having a first main surface and a second main surface arranged in a first direction; A first coating step of coating a first photosensitive glass paste containing a first filler on the first main surface; A masking step of disposing a grayscale mask formed in a binary mode on the second main surface; An exposure step of irradiating ultraviolet rays to the second main surface to expose the first photosensitive glass paste; A developing step of removing the grayscale mask from the second main surface to develop the first photosensitive glass paste; as well as a curing step of removing the light-transmitting substrate from the developed first photosensitive glass paste and curing the first photosensitive glass paste; The longest length of the first filler is longer than the wavelength of the ultraviolet light.

2. The method for manufacturing an optical coupler according to claim 1, wherein: Between the first coating step and the exposure step, a second coating step of coating a second photosensitive glass paste on the first photosensitive glass paste is included. In the exposure step, the first photosensitive glass paste and the second photosensitive glass paste are exposed. In the developing step, the first photosensitive glass paste and the second photosensitive glass paste are developed. In the curing step, the first photosensitive glass paste and the second photosensitive glass paste are cured. The second photosensitive glass paste includes a second filler, and a content rate of the second filler included in the second photosensitive glass paste is lower than a content rate of the first filler included in the first photosensitive glass paste. Alternatively, the second photosensitive glass paste does not include the second filler.

3. The method for manufacturing an optical coupler according to claim 1, wherein: Between the first coating step and the exposure step, a second coating step of coating a second photosensitive glass paste containing a second filler on the first photosensitive glass paste is included. In the exposure step, the first photosensitive glass paste and the second photosensitive glass paste are exposed. In the developing step, the first photosensitive glass paste and the second photosensitive glass paste are developed. In the curing step, the first photosensitive glass paste and the second photosensitive glass paste are cured. The longest length of the second filler is longer than 0 and is shorter than the wavelength of the ultraviolet rays.

4. The method for manufacturing an optical coupler according to any one of claims 1 to 3, wherein: The first filler includes a filler having a non-spherical shape.

5. A method for manufacturing an optical coupler, comprising: A preparation step of preparing a light-transmitting substrate having a first main surface and a second main surface arranged in a first direction, wherein the light-transmitting substrate includes a third filler; A first coating step of coating a first photosensitive glass paste on the first main surface; A masking step of disposing a grayscale mask formed in a binary mode on the second main surface; An exposure step of irradiating ultraviolet rays to the second main surface to expose the first photosensitive glass paste; A developing step of removing the grayscale mask from the second main surface to develop the first photosensitive glass paste; as well as a curing step of removing the light-transmitting substrate from the developed first photosensitive glass paste and curing the first photosensitive glass paste; The longest length of the third filler is longer than the wavelength of the ultraviolet rays.

6. The method for manufacturing an optical coupler according to claim 5, wherein: The third filler includes a filler having a non-spherical shape.

7. An optical coupler, comprising a first photosensitive glass paste, wherein the first photosensitive glass paste comprises a first filler, wherein: The longest length of the first filler is longer than the wavelength of ultraviolet rays irradiated onto the grayscale mask formed in a binary pattern.

8. An optical coupler comprising: a first glass portion including a first glass and a first filler mixed in the first glass; and The second glass portion includes at least a second glass and is connected to the first glass portion. The second glass portion includes a second filler mixed in the second glass, and a content rate of the second filler included in the second glass portion is lower than a content rate of the first filler included in the first glass portion. Alternatively, the second glass portion does not include the second filler.

9. An optical coupler comprising: Glass section 1; and a transmission portion connected to the first glass portion, The first glass portion includes glass and a first filler mixed in the glass. The permeable portion includes a medium and a second filler mixed in the medium. The longest length of the second filler is different from the longest length of the first filler.

10. The optical coupler according to claim 9, wherein The medium is glass.

11. The optical coupler according to any one of claims 7 to 10, wherein: The first filler includes a filler having a non-spherical shape.

12. The optical coupler according to claim 9 or 10, wherein: The transmissive portion is a light-transmissive substrate.

13. The optical coupler according to claim 12, wherein: The second filler includes a filler having a non-spherical shape.

14. A photoelectric conversion circuit module, comprising: The optical coupler according to any one of claims 7 to 13; substrate; and a photoelectric conversion circuit mounted on the substrate, The photoelectric conversion circuit converts an electric signal into light incident on the photocoupler, or converts light emitted from the photocoupler into an electric signal.

15. The photoelectric conversion circuit module according to claim 14, wherein: The substrate is a semiconductor substrate and includes a light emitting portion for emitting light. The optical coupler is mounted on the substrate.

16. An optical transceiver comprising the optical coupler according to any one of claims 7 to 13.

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