Optical module and method for manufacturing optical module

Abstract

The invention provides an optical module and a manufacturing method of the optical module. The optical module includes a base material, an optical semiconductor element, an optical loop element, a first adhesive, and a second adhesive. The base material has a first surface. The optical semiconductor element is provided on the first surface, and has, on a side surface, a first optical port through which light enters, exits, or enters and exits. The optical circuit element has, on a side surface thereof, a second optical port that is optically coupled to the first optical port so as to face the first optical port, and that enters, exits, or enters and exits light. The optical loop element and the optical semiconductor element are arranged side by side on the first surface. The first adhesive mainly comprises a UV curing material and has a first heat conductivity coefficient. The first adhesive is disposed between the optical semiconductor element and the first surface, and fixes the optical semiconductor element to the first surface. The second adhesive mainly comprises a thermosetting material and has a second thermal conductivity higher than the first thermal conductivity. The second adhesive is disposed between the optical semiconductor element and the first surface, and fixes the optical semiconductor element to the first surface.

Description

Technical Field

[0001] The present disclosure relates to an optical module and a method for manufacturing the optical module. Background Art

[0002] Patent Document 1 discloses a flip-chip connection method. This method includes a first step and a second step. In the first step, a conductive paste is transferred to bumps provided on a semiconductor chip. In the second step, the bumps are connected to a conductive pattern on a substrate, and the portions of the semiconductor chip not formed with bumps are bonded to the substrate using an adhesive sealing resin.

[0003] Patent Document 2 discloses a light-emitting device. This device includes a semiconductor light-emitting element, a conductive member, a conductive paste, and a fixing resin. The conductive paste electrically connects the electrodes of the semiconductor light-emitting element to the conductive member. The fixing resin covers the lower side surfaces and bottom surface of the semiconductor light-emitting element, where the conductive paste is not applied, to secure the semiconductor light-emitting element to the conductive member.

[0004] Patent Document 3 discloses a semiconductor device comprising a semiconductor element, a support, sintered silver bonding the semiconductor element to the support, and a resin bonding the semiconductor element to the support. The resin is formed in at least a portion of a contour region along the contour of the semiconductor element.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2000-236002

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2006-108238

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2017-092389

[0010] Patent Document 4: Japanese Patent Application No. 2022-522796

[0011] Sometimes, an optical semiconductor element having an optical port on its side is fixed to a base material after its optical axis is adjusted relative to an optical circuit element having another optical port on its side. To dissipate heat from the optical semiconductor element, it is ideal to use a thermosetting material such as sintered silver with good thermal conductivity to fix the optical semiconductor element to the base material. However, the curing of thermosetting materials such as sintered silver requires extremely high temperatures. Therefore, it is difficult to cure the thermosetting material while holding the optical semiconductor element in a state where its optical axis has been adjusted using a chuck or the like. In addition, when a UV curing material such as a UV curing resin is used to fix the optical semiconductor element to the base material, it is easy to irradiate the UV curing material with ultraviolet light while holding the optical semiconductor element in a state where its optical axis has been adjusted using a chuck or the like, thereby easily curing the UV curing material. However, in this case, due to the low thermal conductivity of the UV curing material, heat dissipation from the optical semiconductor element may be insufficient. Summary of the Invention

[0012] An object of the present disclosure is to provide an optical module and a method for manufacturing the optical module, which can fix the optical semiconductor element to a base material using a thermosetting material with high heat dissipation while maintaining the position of the optical semiconductor element after optical axis adjustment.

[0013] According to one embodiment of the present disclosure, an optical module comprises a base material, an optical semiconductor element, an optical circuit element, a first adhesive, and a second adhesive. The base material has a first surface. The optical semiconductor element is provided on the first surface and has a first optical port on the side for incident, emitted, or incident and output light. The optical circuit element has a second optical port on the side for incident, emitted, or incident and output light and optically coupled to the first optical port. The optical circuit element and the optical semiconductor element are arranged side by side on the first surface. The first adhesive mainly contains a UV curing material and has a first thermal conductivity. The first adhesive is arranged between the optical semiconductor element and the first surface to fix the optical semiconductor element to the first surface. The second adhesive mainly contains a thermosetting material and has a second thermal conductivity higher than the first thermal conductivity. The second adhesive is arranged between the optical semiconductor element and the first surface to fix the optical semiconductor element to the first surface.

[0014] Effects of the Invention

[0015] According to the present disclosure, an optical module and a method for manufacturing the optical module can be provided, which can fix the optical semiconductor element to a base material using a thermosetting material with high heat dissipation while maintaining the position of the optical semiconductor element after optical axis adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a perspective view of an optical module according to one embodiment of the present disclosure.

[0017] Figure 2 It is along Figure 1 A cross-sectional view of the optical module of line II-II.

[0018] Figure 3 1 is a flowchart showing a method for manufacturing the optical module according to the present embodiment.

[0019] Figure 4 This is a cross-sectional view of an optical module according to a modified example of the above embodiment.

[0020] Figure 5 It is a plan view showing a base material, a first adhesive, and a second adhesive.

[0021] Figure 6 It is a cross-sectional view showing the second step in the manufacturing process of the optical module.

[0022] Figure 7 It is a cross-sectional view showing the second step in the manufacturing process of the optical module.

[0023] Figure 8 It is a cross-sectional view showing the second step in the manufacturing process of the optical module.

[0024] Figure 9 It is a plan view showing a base material, a first adhesive, and a second adhesive according to another modified example.

[0025] Figure 10 is a cross-sectional view of an optical module according to a third modified example.

[0026] Figure 11 It is a perspective view showing the appearance of a carrier according to a third modified example.

[0027] Figure 12 This is a diagram for explaining issues associated with optical modules.

[0028] Figure 13 It is a cross-sectional view showing a state where the portion where the first adhesive has spread is blocked by the step.

[0029] Figure 14 This is a perspective view showing the appearance of a carrier as another embodiment of the third modification.

[0030] Figure 15 4 is a cross-sectional view showing an optical module according to a fourth modified example.

[0031] Figure 16 It is a perspective view showing the appearance of a carrier according to a fourth modification.

[0032] Figure 17 It is a cross-sectional view showing a state where the first adhesive is prevented from spreading toward the second contact surface.

[0033] Figure 18This is a perspective view showing the appearance of a carrier as another embodiment of the fourth modification.

[0034] Figure 19 is a cross-sectional view of an optical module according to a fifth modification.

[0035] Description of reference numerals:

[0036] 1A, 1B, 1C, 1D, 1E: optical modules;

[0037] 10A, 10B, 10C: base material;

[0038] 11: first side;

[0039] 11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h: area;

[0040] 12, 13: Groove (concave);

[0041] 12a, 12b, 12c, 13a, 13b, 13c, 13d, 13e: part;

[0042] 20: Optical semiconductor components;

[0043] 20a: first optical port;

[0044] 21: side;

[0045] 22: Optical semiconductor chip;

[0046] 23, 23A, 23B, 23C, 23D, 23E: vector;

[0047] 23a: mounting surface;

[0048] 23b: bottom surface;

[0049] 23ba: first contact surface;

[0050] 23bb: second contact surface;

[0051] 23bc, 23bd: third contact surface;

[0052] 23c: side view;

[0053] 23e, 23i: steps;

[0054] 23j, 23k: side view;

[0055] 30: Optical circuit components;

[0056] 30a: second optical port;

[0057] 30b: monitoring optical port;

[0058] 31: Main side;

[0059] 32: side view;

[0060] 33, 35, 36: optical waveguide;

[0061] 33a: reflection end;

[0062] 34: Built-in photodiode;

[0063] 40: first adhesive;

[0064] 41, 42, 231: part;

[0065] 50: second adhesive;

[0066] 60: third adhesive;

[0067] A1, A2, A3, A4: arrows;

[0068] C1, C2: axis;

[0069] D1, D2, D3, D4: distance;

[0070] OH: distance;

[0071] ST1: first process;

[0072] ST2: second process;

[0073] ST3: The third process;

[0074] ST4: the fourth process;

[0075] ST5: The fifth step;

[0076] W: width. DETAILED DESCRIPTION

[0077] [Description of Embodiments of the Present Disclosure]

[0078] First, the contents of the embodiments of the present disclosure will be described by way of examples.

[0079] [1] According to one embodiment of the present disclosure, an optical module comprises a base material, an optical semiconductor element, an optical circuit element, a first adhesive, and a second adhesive. The base material has a first surface. The optical semiconductor element is provided on the first surface and has a first optical port on the side for incident, emitted, or incident and output light. The optical circuit element has a second optical port on the side for incident, emitted, or incident and output light and optically coupled to the first optical port. The optical circuit element and the optical semiconductor element are arranged side by side on the first surface. The first adhesive mainly contains a UV curing material and has a first thermal conductivity. The first adhesive is arranged between the optical semiconductor element and the first surface to fix the optical semiconductor element to the first surface. The second adhesive mainly contains a thermosetting material and has a second thermal conductivity higher than the first thermal conductivity. The second adhesive is arranged between the optical semiconductor element and the first surface to fix the optical semiconductor element to the first surface.

[0080] In the optical module of the above-mentioned [1], the optical semiconductor element is fixed to the first surface of the base material by a first adhesive and a second adhesive. The first adhesive mainly contains a UV curing material. The second adhesive has a second thermal conductivity higher than the first thermal conductivity and mainly contains a thermosetting material. When manufacturing the optical module, the position of the optical semiconductor element after the optical axis is adjusted can be maintained by a chuck or the like, and the first adhesive can be cured by irradiating ultraviolet light. Then, the second adhesive can be cured by heating while the position of the optical semiconductor element after the optical axis is adjusted is maintained by the first adhesive. Therefore, according to the optical module of the above-mentioned [1], the optical semiconductor element can be fixed to the base material using a thermosetting material with high heat dissipation while maintaining the position of the optical semiconductor element after the optical axis is adjusted.

[0081] [2] In the optical module of [1] above, the optical semiconductor element may include: an optical semiconductor chip having a first optical port; and a carrier carrying the optical semiconductor chip, the carrier being fixed to the first surface by a first adhesive and a second adhesive. In this case, even when the thickness of the optical semiconductor chip is smaller than the thickness of the optical circuit element, the height of the first optical port can be matched with the height of the second optical port.

[0082] [3] In the optical module according to any one of [1] and [2] above, the UV curing material may be a UV curing resin. In this case, the optical semiconductor element can be easily fixed to the base material.

[0083] [4] In the optical module according to any one of [1] to [3] above, the thermosetting material may be sintered silver. Sintered silver has an extremely high thermal conductivity, and thus, in this case, heat from the optical semiconductor element can be efficiently transferred to the base material.

[0084] [5] In the optical module according to any one of [1] to [3] above, the thermosetting material may be sintered silver containing epoxy resin. The second adhesive containing sintered silver containing epoxy resin can suppress shrinkage of the second adhesive during sintering, making it difficult for the second adhesive to peel off from the optical semiconductor element.

[0085] [6] In the optical module of any one of [1] to [5] above, the first adhesive and the second adhesive may be separated from each other on the first surface. In this case, mixing of the first adhesive and the second adhesive before curing is avoided. Thus, curing of the first adhesive can be prevented from being hindered by the second adhesive.

[0086] [7] In the optical module of any one of [1] to [6] above, the base material may have a recess formed between the first adhesive and the second adhesive when viewed from the normal direction of the first surface. The height from the bottom surface of the optical semiconductor element to the first optical port has unevenness due to manufacturing errors. The height position of the first optical port is determined based on the height position of the second optical port of the optical circuit element, so the unevenness in the height from the bottom surface of the optical semiconductor element to the first optical port is absorbed by the thickness of the first adhesive and the second adhesive. When the thickness of the first adhesive and the second adhesive is small, the first adhesive and the second adhesive spread in the lateral direction (along the direction of the first surface) and approach each other. Since the base material has a recess formed between the first adhesive and the second adhesive, the first adhesive and the second adhesive that spread in the direction of approaching each other can fall into the recess. Therefore, the mixing of the first adhesive and the second adhesive on the first surface before curing is avoided, and thus the curing of the first adhesive on the first surface can be prevented from being hindered by the second adhesive.

[0087] [8] Alternatively, the optical module according to any one of [1] to [7] may further include a third adhesive disposed between the first optical port and the second optical port, the third adhesive primarily comprising a UV-curing material that cures faster than the UV-curing material of the first adhesive. In this case, the third adhesive cures faster than the first adhesive when irradiated with ultraviolet light. Therefore, the optical coupling state between the first optical port and the second optical port after the optical axis adjustment can be more firmly maintained.

[0088] [9] In the optical module according to any one of [1] to [8] above, the contact area between the second adhesive and the optical semiconductor element may be larger than the contact area between the first adhesive and the optical semiconductor element. In this case, heat from the optical semiconductor element can be more efficiently transferred to the base material.

[0089]

[10] In the optical module of any one of [1] to [9] above, the first adhesive may be provided on a plurality of areas of the first surface separated by the second adhesive. In this case, when the second adhesive is cured by heating, the position of the first optical port after the optical axis adjustment can be more stably maintained.

[0090]

[11] In the optical module of

[10] , the plurality of regions may be arranged in line symmetry with respect to an axis along the first surface. In this case, the position of the first optical port after the optical axis is adjusted can be maintained more stably.

[0091]

[12] In the optical module of any one of [1] to

[11] above, the optical semiconductor element may have a bottom surface facing the first surface. Alternatively, the first adhesive and the second adhesive may be separated from each other on the bottom surface of the optical semiconductor element. In this case, mixing of the first adhesive and the second adhesive before curing is avoided. Therefore, curing of the first adhesive can be prevented from being hindered by the second adhesive.

[0092]

[13] In the optical module of any one of [2] to

[12] above, the carrier may have a bottom surface opposite to the first surface. Alternatively, the bottom surface may include a first contact surface for the first adhesive to contact and a second contact surface for the second adhesive to contact. Alternatively, the distance between the second contact surface and the first surface may be smaller than the distance between the first contact surface and the first surface. In this case, even if the first adhesive before curing spreads along the bottom surface of the carrier, the extended portion of the first adhesive is blocked by the step between the first contact surface and the second contact surface, thereby preventing the first adhesive from spreading toward the second contact surface. Therefore, according to the optical module of

[13] above, it is possible to avoid the first adhesive and the second adhesive from mixing on the bottom surface of the carrier or in the vicinity thereof, and to avoid the curing of the first adhesive on the bottom surface of the carrier or in the vicinity thereof being hindered by the second adhesive. Moreover, it is possible to prevent the first adhesive from entering between the second adhesive and the bottom surface of the carrier, thereby increasing the area of the second contact surface and improving heat dissipation.

[0093]

[14] In the optical module of

[13] above, the bottom surface of the carrier may further include a third contact surface for the first adhesive to contact. Alternatively, when viewed from the normal direction of the bottom surface of the carrier, the first contact surface is located between the second contact surface and the third contact surface. Alternatively, the distance between the third contact surface and the first surface is smaller than the distance between the first contact surface and the first surface. In this case, the portion of the first adhesive located on the side surface of the carrier and the portion of the first adhesive located on the first contact surface become a form that sandwiches a portion of the carrier from both sides, that is, a portion of the carrier that is arranged between the side surface and the first contact surface. As a result, the fixing strength between the carrier and the base material can be improved.

[0094]

[15] In the optical module of

[13] above, the bottom surface of the carrier may further include a third contact surface for the first adhesive to contact. Alternatively, when viewed from the normal direction of the bottom surface of the carrier, the first contact surface is located between the second contact surface and the third contact surface. Alternatively, the distance between the third contact surface and the first surface is greater than the distance between the first contact surface and the first surface. In this case, the extended portion of the first adhesive before curing is further blocked by the step between the first contact surface and the third contact surface. Therefore, the first adhesive is more effectively prevented from extending toward the second contact surface.

[0095]

[16] A method for manufacturing an optical module according to one embodiment of the present disclosure includes: a configuration step, a configuration step, a step of curing a first adhesive, and a step of curing a second adhesive. In the first configuration step, an optical circuit element, a first adhesive, and a second adhesive are configured on a first surface of a base material, wherein the optical circuit element has a second optical port on a side for incident, emitted, or incident and outgoing light, the first adhesive mainly contains a UV curing material and has a first thermal conductivity, and the second adhesive mainly contains a thermosetting material and has a second thermal conductivity higher than the first thermal conductivity. In the second configuration step, an optical semiconductor element having a first optical port on a side for incident, emitted, or incident and outgoing light is configured. In the second configuration step, the optical semiconductor element is brought into contact with the first adhesive and the second adhesive, and the position of the optical semiconductor element is adjusted in such a way that the first optical port and the second optical port are optically coupled. Such adjustment can also be performed by an active centering method or a passive centering method. In the step of curing the first adhesive, the optical semiconductor element is held in a position adjusted for optical coupling, and the first adhesive is cured by irradiation with ultraviolet light. In the step of curing the second adhesive, the second adhesive is cured by heating while the first adhesive is already cured.

[0096] In the manufacturing method of the above-mentioned

[16] , the optical semiconductor element is fixed to the first surface of the base material by a first adhesive and a second adhesive. The first adhesive mainly contains a UV curing material. The second adhesive has a second thermal conductivity higher than the first thermal conductivity of the first adhesive and mainly contains a thermosetting material. In the process of curing the first adhesive, the position of the optical semiconductor element after the optical axis is adjusted can be maintained by a chuck or the like and ultraviolet light can be irradiated to cure the first adhesive. Then, in the process of curing the second adhesive, the second adhesive can be cured by heating while the position of the optical semiconductor element after the optical axis is adjusted is maintained by the first adhesive. Therefore, according to the manufacturing method of the above-mentioned

[16] , the optical semiconductor element can be fixed to the base material using a thermosetting material with high heat dissipation while maintaining the position of the optical semiconductor element after the optical axis is adjusted.

[0097] [Details of the embodiments of the present disclosure]

[0098] Specific examples of the present disclosure are described below with reference to the accompanying drawings. It should be noted that the present invention is not limited to these examples but is defined by the claims, which are intended to encompass all modifications within the meaning and scope of the claims. In the following description, identical elements are denoted by the same reference numerals throughout the accompanying drawings, and duplicate descriptions are omitted.

[0099] Figure 1 This is a perspective view of an optical module 1A according to one embodiment of the present disclosure. Figure 2 It is along Figure 1 A cross-sectional view of the optical module 1A along line II-II. Figure 1 and Figure 2 As shown in FIG. 1 , the optical module 1A of the present embodiment includes a substrate 10A, an optical semiconductor element 20 , an optical circuit element 30 , a first adhesive 40 , a second adhesive 50 , and a third adhesive 60 . Figure 1 , the first adhesive 40 , the second adhesive 50 , and the third adhesive 60 are schematically shown.

[0100] The base material 10A has a flat first surface 11. While the figure illustrates a rectangular planar shape for the first surface 11, the planar shape of the first surface 11 is not limited thereto. The base material 10A is, for example, an insulating substrate. A metal film is formed on the first surface 11 for bonding with the second adhesive 50.

[0101] The optical semiconductor element 20 is provided on the first surface 11. The optical semiconductor element 20 has a first optical port 20a for incident, emitted, or incident and emitted light on the side surface 21. The optical semiconductor element 20 of the illustrated example includes an optical semiconductor chip 22 and a carrier 23. The optical semiconductor chip 22 has an end surface constituting the side surface 21, and has a first optical port 20a on the end surface. The optical semiconductor chip 22 is, for example, a semiconductor optical amplifier (SOA). The optical semiconductor chip 22 is made of, for example, a compound material such as indium phosphide (InP). The carrier 23 has a roughly rectangular appearance, having a mounting surface 23a and a bottom surface 23b facing opposite to the mounting surface 23a. The optical semiconductor chip 22 is mounted on the mounting surface 23a. The bottom surface 23b is opposite to the first surface 11. The bottom surface 23b is also the bottom surface of the optical semiconductor element 20. The bottom surface 23b in this embodiment is a flat surface. The carrier 23 is formed by forming a metal film such as a gold (Au) film on the surface of a ceramic material such as aluminum nitride (AlN). The back electrode of the optical semiconductor chip 22 is electrically connected to the metal film provided on the mounting surface 23 a of the carrier 23 .

[0102] The optical circuit element 30 and the optical semiconductor element 20 are arranged side by side on the first surface 11. For example, the optical circuit element 30 is fixed to the first surface 11 by an adhesive (not shown). The optical circuit element 30 is, for example, a silicon photonic chip (SiPh) having an optical circuit formed on the main surface 31. The optical circuit element 30 has a second optical port 30a on the side surface 32 for inputting, outputting, or both inputting and outputting light. The second optical port 30a is opposite to the first optical port 20a and is optically coupled to the first optical port 20a. There is only a third adhesive 60 between the first optical port 20a and the second optical port 30a, or when the third adhesive 60 is not provided, there is only air, and no optical components such as lenses are provided between the first optical port 20a and the second optical port 30a. This configuration is called edge coupling. The distance between the first optical port 20a and the second optical port 30a is, for example, several μm.

[0103] As an example, the optical circuit element 30 further includes a linear optical waveguide 33, a built-in photodiode 34, and a monitoring optical port 30b. The optical waveguide 33 is formed on the main surface 31. The first end of the optical waveguide 33 serves as the second optical port 30a. The second end of the optical waveguide 33 serves as a reflection end 33a. Light introduced from the second optical port 30a is reflected at the reflection end 33a and emitted from the second optical port 30a. Thus, the optical waveguide 33, together with the optical waveguide within the optical semiconductor chip 22, forms a laser resonator. A spot size converter may also be provided between the second optical port 30a and the first end of the optical waveguide 33. The laser light generated by the optical semiconductor chip 22 and the optical waveguide 33 is emitted, for example, from an optical port (not shown) of the optical semiconductor chip 22 that is opposite the first optical port 20a to the outside of the optical module 1A.

[0104] A built-in photodiode 34 is formed on the main surface 31. The built-in photodiode 34 is optically coupled to the optical waveguide 33 via an optical waveguide 35 formed on the main surface 31. The built-in photodiode 34 outputs an electrical signal corresponding to the optical intensity of the laser light generated within the optical waveguide 33. For example, a control device located outside the optical module 1A controls the gain of the optical semiconductor element 20 based on this electrical signal. The monitoring optical port 30b is optically coupled to the optical waveguide 33 via an optical waveguide 36 formed on the main surface 31. A portion of the laser light generated within the optical waveguide 33 is supplied to the outside of the optical module 1A from the monitoring optical port 30b.

[0105] The first adhesive 40 is arranged between the optical semiconductor element 20 and the first surface 11. In the example shown in the figure, the first adhesive 40 is arranged between the bottom surface 23b of the carrier 23 and the first surface 11, and is in contact with both the bottom surface 23b and the first surface 11. That is, the bottom surface 23b of the carrier 23 includes a first contact surface 23ba for the first adhesive 40 to contact. Alternatively, the first adhesive 40 is also in contact with the side surface of the carrier 23. The first adhesive 40 mainly includes a UV curing material that is cured by irradiation with ultraviolet rays (UV). The UV curing material can also be a UV curing resin. The first adhesive 40 fixes the optical semiconductor element 20 (in the example shown in the figure, the carrier 23) to the first surface 11. The thickness of the first adhesive 40, in other words, the distance between the bottom surface 23b of the carrier 23 and the first surface 11 is, for example, greater than 20 μm and less than 70 μm when the first adhesive 40 is cured. The first adhesive 40 has a thermal conductivity (first thermal conductivity). The first thermal conductivity of the first adhesive after curing may be less than 1 W / m·K.

[0106] The second adhesive 50 is arranged side by side with the first adhesive 40 on the first surface 11 and between the optical semiconductor element 20 and the first surface 11. In the illustrated example, the second adhesive 50 is arranged between the bottom surface 23b of the carrier 23 and the first surface 11, contacting both the bottom surface 23b and the first surface 11, more specifically, the metal films formed on the bottom surface 23b and the first surface 11, respectively. That is, the bottom surface 23b of the carrier 23 includes a second contact surface 23bb with which the second adhesive 50 contacts. Alternatively, the second adhesive 50 may also contact the side surfaces of the carrier 23, more specifically, the metal films formed on the side surfaces of the carrier 23. The second adhesive 50 primarily comprises a thermosetting material that cures by heating. The thermosetting material may be sintered silver or sintered silver containing an epoxy resin. The second adhesive 50 has a higher thermal conductivity (second thermal conductivity) than the thermal conductivity (first thermal conductivity) of the first adhesive 40. The second thermal conductivity of the second adhesive after curing may also be greater than 20 W / m·K. The second thermal conductivity may also be greater than 20 times the first thermal conductivity. Sintered silver has a thermal conductivity greater than 100 W / m·K. The second thermal conductivity may also be greater than 100 times the first thermal conductivity. The second adhesive 50 fixes the optical semiconductor element 20 (in the illustrated example, the carrier 23) to the first surface 11. Moreover, the second adhesive 50 conducts the heat generated in the optical semiconductor element 50 to the base material 10A more efficiently than the first adhesive.

[0107] like Figure 2As shown, after each of the first and second adhesives 40 and 50 has been cured, they are not in contact with each other on the first surface 11 (or on the bottom surface 23b of the carrier 23), but are separated from each other. In the cured state, the width of the gap between the first and second adhesives 40 and 50 is, for example, not less than 0.05 mm and not more than 0.25 mm. The contact area between the second adhesive 50 and the optical semiconductor element 20 (in the illustrated example, the carrier 23) is larger than the contact area between the first adhesive 40 and the optical semiconductor element 20 (in the illustrated example, the carrier 23).

[0108] The third adhesive 60 is disposed between the first optical port 20a and the second optical port 30a, contacting both the first optical port 20a and the second optical port 30a. Alternatively, the third adhesive 60 may also contact one or both of the upper surface of the optical semiconductor element 20 (in the illustrated example, the upper surface of the optical semiconductor chip 22) and the main surface 31 of the optical circuit element 30. The third adhesive 60 primarily comprises a UV-curing material that cures faster than the UV-curing material of the first adhesive 40 under UV irradiation. The UV-curing material may be a UV-curing resin. The third adhesive 60 is translucent to light transmitted between the first optical port 20a and the second optical port 30a, and performs refractive index matching between the first optical port 20a and the second optical port 30a. The third adhesive 60 is, for example, an epoxy resin, and its refractive index after curing may be 1.4 to 1.6. Furthermore, the optical semiconductor chip 22 protrudes further toward the optical circuit element 30 in the X direction than the side surface 23c of the carrier 23 facing the optical circuit element 30. Therefore, in the X-direction, the side surface 21 of the optical semiconductor chip 22 is located between the side surface 23c of the carrier 23 and the optical circuit element 30. The optical semiconductor element 20 has a distance OH between the side surface 21 of the optical semiconductor chip 22 and the side surface 23c of the carrier 23 in the X-direction. Providing this distance OH prevents the second adhesive 50 from contacting the third adhesive 60 when it creeps up the side surface 23c toward the optical semiconductor chip 22 in the z-direction. The distance OH can be, for example, 0.05 mm or greater, or 0.1 mm or less.

[0109] Figure 3 FIG. 1 is a flowchart showing a method for manufacturing the optical module 1A of the present embodiment. Figure 3As shown, this manufacturing method includes a first step ST1, a second step ST2, a third step ST3, a fourth step ST4, and a fifth step ST5. In the first step ST1, the lightwave circuit element 30, the first adhesive 40, and the second adhesive 50 are placed on the first surface 11 of the substrate 10A. At this time, the first adhesive 40 and the second adhesive 50 are applied to the first surface 11. The thickness of the first adhesive 40 and the second adhesive 50 at this time, in other words, the height from the first surface 11 to each vertex of the first adhesive 40 and the second adhesive 50, is, for example, 70 μm or greater, and in one example, 100 μm. This height represents the height before the optical axis adjustment described later.

[0110] In the second step ST2, the optical semiconductor element 20 is grasped by a chuck or the like. Then, a driving current is supplied to the optical semiconductor element 20 via the chuck or the like, thereby emitting light from the first optical port 20a of the optical semiconductor element 20. The optical semiconductor element 20 (specifically, the bottom surface 23b of the carrier 23) is brought into contact with the first adhesive 40 and the second adhesive 50, and the position and angle of the optical semiconductor element 20 are adjusted (optical axis adjustment) in such a manner that the first optical port 20a and the second optical port 30a are optically coupled. The optical coupling state of the first optical port 20a and the second optical port 30a can be known, for example, by detecting the size of the electrical signal output from the built-in photodiode 34 or the intensity of the light emitted from the monitoring optical port 30b. Adjustment of the position and angle of the optical semiconductor element 20 includes adjustment of the position in the direction of the optical axis ( Figure 1 The adjustment of the horizontal position intersecting the optical axis direction ( Figure 1 The arrow A2 shown in FIG. 1 is used to adjust the position of the normal direction of the first surface 11 ( Figure 1 The arrow A3 shown) and the adjustment of the angle around the axis along the normal line of the first surface 11 ( Figure 1 The optical axis is adjusted so that the magnitude of the electrical signal output from the built-in photodiode 34 or the intensity of the light emitted from the monitoring optical port 30b is greater than a specified value. The thickness of the first adhesive 40 and the second adhesive 50 can be varied by adjusting the position of the normal direction of the first surface 11 during optical axis adjustment. The first adhesive 40 and the second adhesive 50 are each easily deformed by external forces before curing. It should be noted that in the following description, for convenience, the optical axis direction is sometimes referred to as the X direction, the lateral direction intersecting the optical axis direction is referred to as the Y direction, and the height direction intersecting the X and Y directions is referred to as the Z direction.

[0111] In the third step ST3, the optical semiconductor element 20, after the optical axis has been adjusted, is held by a chuck or the like in the position adjusted for optical coupling, maintaining the position and angle of the optical semiconductor element 20. Furthermore, a third adhesive 60 is placed (applied) between the first optical port 20a and the second optical port 30a. In the fourth step ST4, the optical semiconductor element 20, after the optical axis has been adjusted, is held by a chuck or the like, maintaining the position and angle of the optical semiconductor element 20. Furthermore, the first adhesive 40 and the third adhesive 60 are cured by irradiation with ultraviolet light. As described above, the third adhesive 60 primarily contains a UV-curing material that cures faster than the UV-curing material of the first adhesive 40. Therefore, at this stage, the third adhesive 60 cures faster than the first adhesive 40. During the curing of the third adhesive 60, the exposed area around the first adhesive 40 can be temporarily covered with a shield to prevent ultraviolet light from irradiating the first adhesive 40.

[0112] In the fifth step ST5, while the first adhesive 40 and the third adhesive 60 are already cured, the second adhesive 50 is cured (sintered) by heating. In this fifth step ST5, multiple semi-finished products that have completed the steps up to the fourth step ST4 can be placed in a heating furnace to collectively cure the second adhesive 50 of the multiple semi-finished products. The above steps are used to manufacture the optical module 1A of this embodiment.

[0113] The effects achieved by the optical module 1A and its manufacturing method of the present embodiment described above will now be described. In the optical module 1A of this embodiment, the optical semiconductor element 20 is secured to the first surface 11 of the base material 10A by a first adhesive 40 and a second adhesive 50. The first adhesive 40 primarily comprises a UV-curable material and has a thermal conductivity (first thermal conductivity). The second adhesive 50 primarily comprises a thermosetting material and has a thermal conductivity (second thermal conductivity) higher than that of the first adhesive 40 (first thermal conductivity). During the manufacture of this optical module 1A, the optical axis can be adjusted while the first and second adhesives 40, 50 are deformable. After the optical axis is adjusted, the optical semiconductor element 20 is held in position by a chuck or the like, and then irradiated with ultraviolet light to cure the first adhesive 40. Subsequently, while the optical semiconductor element 20 is held in position by the first adhesive 40 after the optical axis is adjusted, the second adhesive 50 can be cured by heating. Therefore, according to the optical module 1A of this embodiment, the optical semiconductor element 20 can be fixed to the base material 10A using a thermosetting material with high heat dissipation properties while maintaining the position of the optical semiconductor element 20 after optical axis adjustment. As a result, optical axis displacement between the first optical port 20a and the second optical port 30a during thermal curing of the second adhesive 50 can be prevented, while heat dissipation from the optical semiconductor element 20 to the base material 10A is improved. It should be noted that the thermal resistance from the bottom surface 23b of the carrier 23 to the first surface 11 is, for example, 5K / W or less.

[0114] As shown in this embodiment, the optical semiconductor element 20 may include an optical semiconductor chip 22 having a first optical port 20a, and a carrier 23 carrying the optical semiconductor chip 22, with the carrier 23 being fixed to the first surface 11 via a first adhesive 40 and a second adhesive 50. In this case, even when the thickness of the optical semiconductor chip 22 is smaller than the thickness of the optical circuit element 30, the height of the first optical port 20a can be matched to the height of the second optical port 30a.

[0115] As described above, the UV curing material may also be a UV curing resin. In this case, the optical semiconductor element 20 can be easily fixed to the base material 10A after adjusting the optical axis. Thus, the optical semiconductor element 20 can be fixed to the base material 10A with sufficient strength using the first adhesive 40. As a result, it is possible to prevent the optical axis from shifting between the first optical port 20a and the second optical port 30a when the second adhesive 50 is thermally cured.

[0116] As mentioned above, the thermosetting material can also be sintered silver. Sintered silver has an extremely high thermal conductivity. Therefore, in this case, the thermal resistance between the optical semiconductor element 20 and the substrate 10A can be reduced. This allows heat from the optical semiconductor element 20 to be transferred to the substrate 10A more efficiently.

[0117] As mentioned above, the thermosetting material may also be sintered silver containing epoxy resin. The second adhesive 50 containing sintered silver containing epoxy resin improves the adhesion between the second adhesive 50 and the optical semiconductor element 20. As a result, shrinkage of the second adhesive 50 during sintering can be suppressed, making it difficult for the second adhesive 50 to peel from the optical semiconductor element 20.

[0118] As shown in this embodiment, the first adhesive 40 and the second adhesive 50 may be separated from each other on the first surface 11 (or on the bottom surface 23b of the carrier 23). In this case, mixing of the first adhesive 40 and the second adhesive 50 before curing is avoided. Therefore, the curing of the first adhesive 40 can be prevented from being hindered by the second adhesive 50.

[0119] As shown in this embodiment, the optical module 1A may further include a third adhesive 60 disposed between the first optical port 20a and the second optical port 30a. Alternatively, the third adhesive 60 may primarily contain a UV-curing material that cures faster (i.e., is highly reactive) than the UV-curing material of the first adhesive 40. In this case, when irradiated with ultraviolet light, the third adhesive 60 cures faster than the first adhesive 40. Therefore, the optical coupling state between the first optical port 20a and the second optical port 30a after optical axis adjustment can be more firmly maintained. It should be noted that as long as only the third adhesive 60 can be selectively irradiated with ultraviolet light without irradiating the first adhesive 40 with ultraviolet light, the curing speed of the UV-curing material of the third adhesive 60 may be the same as that of the UV-curing material of the first adhesive 40.

[0120] As shown in this embodiment, the contact area between the second adhesive 50 and the optical semiconductor element 20 may be larger than the contact area between the first adhesive 40 and the optical semiconductor element 20. By setting the contact area of the first adhesive 40 to a size sufficient to ensure sufficient fixing strength, and by making the contact area of the second adhesive 50 larger than the contact area of the first adhesive 40, heat from the optical semiconductor element 20 can be more efficiently transferred to the base material 10A. For example, the fixing strength of the first adhesive 40 is greater than or equal to a level sufficient to suppress optical axis misalignment between the first optical port 20a and the second optical port 30a during thermal curing of the second adhesive 50.

[0121] In the manufacturing method of this embodiment, the optical semiconductor element 20 is fixed to the first surface 11 of the base material 10A by a first adhesive 40 and a second adhesive 50. The first adhesive 40 mainly contains a UV curable material and has a thermal conductivity (first thermal conductivity). The second adhesive 50 has a thermal conductivity (second thermal conductivity) higher than the thermal conductivity (first thermal conductivity) of the first adhesive 40 and mainly contains a thermosetting material. In the step of curing the first adhesive 40, the position of the optical semiconductor element 20 after the optical axis is adjusted can be maintained by a chuck, etc., while irradiating ultraviolet light, thereby curing the first adhesive 40 while the second adhesive 50 is in an uncured state. Then, in the step of curing the second adhesive 50, the position of the optical semiconductor element 20 after the optical axis is adjusted can be maintained by the cured first adhesive 40, and the second adhesive 50 can be cured by heating. Therefore, according to the manufacturing method of this embodiment, the optical semiconductor element 20 can be fixed to the base material 10A using a thermosetting material with high heat dissipation properties while maintaining the position of the optical semiconductor element 20 after the optical axis is adjusted. As a result, it is possible to prevent the optical axis from shifting between the first optical port 20a and the second optical port 30a, and to efficiently transfer heat from the optical semiconductor element 20 to the base material 10A.

[0122] [First Modification]

[0123] Figure 4 This is a cross-sectional view of an optical module 1B according to a first variation of the above-described embodiment. This variation differs from the optical module 1A of the above-described embodiment in the following respects, but otherwise is identical to the optical module 1A of the above-described embodiment. In this variation, the third adhesive 60 is omitted. Furthermore, this variation includes a base material 10B in place of the base material 10A. Figure 5 This is a top view showing the base material 10B, the first adhesive 40, and the second adhesive 50. It should be noted that the third adhesive 60 is omitted in the optical module 1B of this modified example. However, the third adhesive 60 can also be provided in the same manner as in the optical module 1A. For example, the third adhesive 60 can be provided to achieve refractive index matching between the first optical port 20a and the second optical port 30a. The third adhesive 60 has a refractive index closer to that of the optical semiconductor chip 22 and the optical circuit element 30 than that of air (refractive index matching). This suppresses reflections between the first optical port 20a and the second optical port 30a. In the optical modules 1A and 1B, the optical semiconductor element 20 is primarily secured to the base materials 10A and 10B using the first adhesive 40 and the second adhesive 50.

[0124] like Figure 4 and Figure 5As shown, the first adhesive 40 in this variation is applied to two areas of the first surface 11, sandwiched between the second adhesive 50. In other words, the area provided with the first adhesive 40, the second adhesive 50, and another area provided with the first adhesive 40 are arranged in this order. This arrangement direction can coincide with the arrangement direction (X direction) of the optical semiconductor element 20 and the lightwave circuit element 30. Furthermore, on the bottom surface 23b of the carrier 23, a first contact surface 23ba with which the first adhesive 40 contacts, a second contact surface 23bb with which the second adhesive 50 contacts, and another first contact surface 23ba with which the first adhesive 40 contacts are arranged in this order.

[0125] The base material 10B has a first surface 11 and a groove 12 (recess) formed on the first surface 11. The groove 12 is formed at least between the first adhesive 40 and the second adhesive 50 when viewed from the normal direction (Z direction) of the first surface 11. Figure 4 As shown, in the cross section extending in the X direction and the Z direction, the shape of the groove 12 can be various shapes such as a rectangle, an inverted trapezoid or a semicircle. In one example, the width of the groove 12 (in Figure 4 The length in the X direction is 0.1 mm, and the depth of the groove 12 (the length in the Z direction) is 0.12 mm. Alternatively, the groove 12 may be formed on the side opposite to the second adhesive 50 when viewed from the first adhesive 40 and on the side opposite to the first adhesive 40 when viewed from the second adhesive 50. Figure 5 In the example shown, the groove 12 includes a portion 12a, a portion 12b, and a portion 12c. The portion 12a surrounds an area 11a provided with the first adhesive 40. The portion 12b surrounds another area 11b provided with the first adhesive 40. The portion 12c surrounds an area 11c provided with the second adhesive 50. The shape of the portion 12a and the portion 12b observed from the normal direction (Z direction) of the first surface 11 is, for example, a square or a rectangle. The shape of the portion 12c observed from the normal direction (Z direction) of the first surface 11 may also be a square or a rectangle. Alternatively, as Figure 5 As shown, the shape of the portion 12c viewed from the normal direction (Z direction) of the first surface 11 may also be a shape in which the portions 12a and 12b are embedded in a square or a rectangle. In this case, the area provided with the second adhesive 50 has an H-shape. Figure 5 In the embodiment, the portion 12a and the portion 12b are arranged in the X direction with the region 11c therebetween, but the portion 12a and the portion 12b may be arranged in the Y direction with the region 11c therebetween.

[0126] Figure 6 、 Figure 7 as well as Figure 8 This is a diagram showing the second step ST2 (see Figure 3 First, the optical semiconductor element 20 held by a chuck or the like is brought close to the first adhesive 40 and the second adhesive 50 arranged on the first surface 11 (see Figure 6 At this time, the first adhesive 40 and the second adhesive 50 are applied thickly in advance, taking into account the unevenness caused by the manufacturing error in the height from the bottom surface 23b of the optical semiconductor element 20 to the first optical port 20a. Next, the optical semiconductor element 20 (specifically, the bottom surface 23b of the carrier 23) is brought into contact with the first adhesive 40 and the second adhesive 50 (see Figure 7 Then, the position and angle of the optical semiconductor element 20 are adjusted so that the first optical port 20a and the second optical port 30a are optically coupled (see Figure 8 ). At this time, the height position of the first optical port 20a is determined by the height position of the second optical port 30a. Therefore, the unevenness in the height from the bottom surface 23b of the optical semiconductor element 20 to the first optical port 20a is absorbed by the deformation of the first adhesive 40 and the second adhesive 50 (the change in thickness in the Z direction). When the height from the bottom surface 23b to the first optical port 20a is large, the first adhesive 40 and the second adhesive 50 are flattened by the optical semiconductor element 20, and the thickness of the first adhesive 40 and the second adhesive 50 becomes smaller. In this case, the remaining portions of the first adhesive 40 and the second adhesive 50 expand in the X direction and approach each other. It should be noted that the remaining portions of the first adhesive 40 and the second adhesive 50 also expand in the Y direction.

[0127] In this modified example, the base material 10B includes a groove 12 formed between the first adhesive 40 and the second adhesive 50. This allows the remaining portions of the first adhesive 40 and the second adhesive 50, which have expanded toward each other, to fall into the groove 12. This prevents mixing of the uncured first adhesive 40 and the second adhesive 50 on the first surface 11. Consequently, the curing of the first adhesive 40 on the first surface 11 is prevented from being hindered by the second adhesive 50. For example, when uncured sintered silver is mixed with uncured UV-curable resin, the UV-curable resin may not fully cure. It should be noted that in this case, the first adhesive 40 and the second adhesive 50 are mixed within the groove 12. However, even if the first adhesive 40 within the groove 12 does not fully cure, the effect on the fixing strength between the base material 10B and the carrier 23 and the effect on heat dissipation through the second adhesive 50 are minimal.

[0128] In this modified example, the first adhesive 40 is applied to multiple regions 11a and 11b of the first surface 11, separated by the second adhesive 50. In this case, when the second adhesive 50 is cured by heating, the optical semiconductor element 20 is prevented from tilting relative to the first surface 11, and the position of the first optical port 20a after optical axis adjustment is more stably maintained. As a result, optical axis misalignment between the first optical port 20a and the second optical port 30a can be more reliably prevented.

[0129] like Figure 5 As shown, the regions 11a and 11b may be arranged symmetrically about an axis C1 extending along the first surface 11. In this case, tilting of the optical semiconductor element 20 can be suppressed after the first adhesive 40 is cured, and the position of the first optical port 20a after optical axis adjustment can be further stably maintained. The axis C1 may also be the center line of the region 11c in the X direction.

[0130] As shown in this modified example, portion 12a of the groove 12 may surround region 11a where the first adhesive 40 is provided, while portion 12b of the groove 12 may surround region 11b where the first adhesive 40 is provided. In this case, surface tension generated by the edge of the groove 12 in the first adhesive 40 can be increased, thereby increasing the thickness of the first adhesive 40, which has low thixotropy, before contact with the optical semiconductor element 20. As a result, the width of uneven absorption caused by manufacturing errors in the height from the bottom surface 23b of the optical semiconductor element 20 to the first optical port 20a, that is, the range of variation in the thickness of the first adhesive 40, can be increased.

[0131] [Second Modification]

[0132] Figure 9 1 is a top view of a base material 10C, a first adhesive 40, and a second adhesive 50 according to a second modification. In this example, four regions 11d, 11e, 11f, and 11g provided with the first adhesive 40 are arranged at the four corners of the region 11h provided with the second adhesive 50. The base material 10C has a groove 13 (recess). The groove 13 includes a portion 13a, a portion 13b, a portion 13c, a portion 13d, and a portion 13e. The portions 13a to 13d respectively surround the four regions 11d to 11g provided with the first adhesive 40. The portion 13e surrounds the region 11h provided with the second adhesive 50. The shapes of the portions 13a to 13d observed from the normal direction (Z direction) of the first surface 11 are, for example, square or rectangular. The shape of the portion 13e observed from the normal direction (Z direction) of the first surface 11 may also be a square or a rectangle. Alternatively, as Figure 9As shown, the shape of portion 13e viewed from the normal direction (Z direction) of first surface 11 may be a shape in which portions 13a to 13d are partially embedded in a square or rectangle. In this case, region 11h where second adhesive 50 is provided has a cross shape.

[0133] exist Figure 9 In the illustrated example, the base material 10C also includes a groove 13 formed between the first adhesive 40 and the second adhesive 50. This allows the first adhesive 40 and the second adhesive 50, which expand toward each other during optical axis adjustment, to fall into the groove 13. This prevents the uncured first adhesive 40 and the uncured second adhesive 50 from mixing on the first surface 11. Consequently, the curing of the first adhesive 40 on the first surface 11 is prevented from being hampered by the mixing of the second adhesive 50.

[0134] exist Figure 9 In the example shown, the first adhesive 40 is also applied to the plurality of regions 11d, 11e, 11f, and 11g of the first surface 11, sandwiched between the second adhesive 50. In this case, when the second adhesive 50 is cured by heating, the optical semiconductor element 20 is secured to the first surface 11 by the first adhesive 40, which has cured first. This prevents tilting of the optical semiconductor element 20 and more stably maintains the position of the first optical port 20a after optical axis adjustment. As a result, optical axis misalignment between the first optical port 20a and the second optical port 30a can be more reliably prevented.

[0135] exist Figure 9 In the example shown, regions 11d through 11g are also arranged symmetrically about axis C2 and axis C3 along first surface 11. This prevents tilting of optical semiconductor element 20 after curing of first adhesive 40, further stably maintaining the position of first optical port 20a after optical axis adjustment. Axis C2 may also be the centerline of region 11h in the X direction, and axis C3 may be the centerline of region 11h in the Y direction.

[0136] exist Figure 9 In the example shown, portions 13a through 13d of the groove 13 may each surround regions 11d through 11g where the first adhesive 40 is provided. In this case, surface tension is generated in the first adhesive 40 by the edges of the groove 13, thereby increasing the thickness of the first adhesive 40, which has low thixotropy, before contact with the optical semiconductor element 20. As a result, the absorption width caused by manufacturing errors in the height from the bottom surface 23b of the optical semiconductor element 20 to the first optical port 20a, or the range of variation in the thickness of the first adhesive 40, can be increased.

[0137] [Third Modification]

[0138] Figure 10 This is a cross-sectional view of an optical module 1C according to a third variant. Optical module 1C according to this variant differs from optical module 1B according to the first variant in the following respects; otherwise, it is identical to optical module 1B according to the first variant. Optical module 1C according to this variant includes a carrier 23A in place of carrier 23. Like carrier 23 in the aforementioned embodiment, carrier 23A has a generally rectangular parallelepiped shape, including a mounting surface 23a and a bottom surface 23b. An optical semiconductor chip 22 is mounted on mounting surface 23a. Bottom surface 23b is opposed to first surface 11. Carrier 23A is made of the same material as carrier 23 in the aforementioned embodiment.

[0139] Figure 11 23A is a perspective view showing the appearance of the carrier 23A. Figure 10 and Figure 11 As shown, in the carrier 23A, the first contact surface 23ba and the second contact surface 23bb are both flat surfaces, and the distance D2 between the second contact surface 23bb and the first surface 11 is smaller than the distance D1 between the first contact surface 23ba and the first surface 11. In other words, the first contact surface 23ba is recessed relative to the second contact surface 23bb in the direction toward the mounting surface 23a. That is, relative to the imaginary plane containing the second contact surface 23bb, the first contact surface 23ba is located close to the mounting surface 23a. Therefore, a step 23e is formed between the first contact surface 23ba and the second contact surface 23bb. The surface of the step 23e is perpendicular to the bottom surface 23b or inclined relative to the bottom surface 23b. The difference between the distance D2 and the distance D1 (D2-D1), that is, the height of the step 23e, is, for example, greater than 20μm and less than 50μm. The distance D1 is, for example, greater than 20μm and less than 70μm.

[0140] One of the two first contact surfaces 23ba of the carrier 23A is connected to the region 11a (see Figure 5 ) and extends in the Y direction. The other of the two first contact surfaces 23ba is in contact with the first adhesive 40 provided in the region 11b (refer to Figure 5 ) and extend along the Y direction. Both ends of these first contact surfaces 23ba reach a pair of side surfaces of the carrier 23A, namely, the side surface 23j and the side surface 23k that intersect the Y direction and face opposite to each other.

[0141] The position of the step 23e in the X direction may also be determined by the relative positional relationship between the step 23e and the groove 12. That is, the step 23e may be located on the groove 12 or outside the groove 12 when viewed from the normal direction of the bottom surface 23b.

[0142] The effects obtained by this modification example will be described. Figure 12It is a figure for explaining the problems of the optical module of the above-mentioned embodiment and each modified example. As described above, on the first surface 11, the first adhesive 40 and the second adhesive 50 are isolated from each other. In addition, in the first modified example and the second modified example, before the first adhesive 40 and the second adhesive 50 are cured, the remaining parts of the first adhesive 40 and the second adhesive 50 that spread in the direction of approaching each other fall into the groove 12. However, the first adhesive 40 with relatively high fluidity before curing sometimes spreads along the bottom surface 23b of the carrier 23. In this case, as shown in FIG. Figure 12 As shown in section A of FIG, the first adhesive 40 comes into contact with the second adhesive 50 on and near the bottom surface 23b. As a result, the first adhesive 40 and the second adhesive 50 mix on the first surface 11, and the curing of the first adhesive 40 on the first surface 11 may be hindered by the second adhesive 50. Furthermore, when the first adhesive 40 enters between the second adhesive 50 and the bottom surface 23b, the area of the second contact surface 23bb decreases, reducing heat dissipation.

[0143] To address the above-mentioned problem, in this modified example, the distance D2 between the second contact surface 23bb and the first surface 11 on the bottom surface 23b of the carrier 23A is smaller than the distance D1 between the first contact surface 23ba and the first surface 11. In this case, Figure 13 As shown, even if the uncured first adhesive 40 spreads along the bottom surface 23b, the extended portion of the first adhesive 40 is blocked by the step 23e, thus preventing the first adhesive 40 from spreading toward the second contact surface 23bb. Therefore, according to this variation, the first adhesive 40 and the second adhesive 50 from mixing on or near the bottom surface 23b, and the curing of the first adhesive 40 on or near the bottom surface 23b is prevented by the second adhesive 50. Furthermore, the first adhesive 40 is prevented from entering between the second adhesive 50 and the bottom surface 23b, which increases the area of the second contact surface 23bb and improves heat dissipation.

[0144] Figure 14 2 is a perspective view showing the appearance of a carrier 23B as another embodiment of this modification. The difference between the carrier 23B and the carrier 23A is that the four corners of the bottom surface 23B each have a first contact surface 23ba. Figure 9 The second modified example shown uses this carrier 23B, and the effects of the above-mentioned present modified example can be achieved.

[0145] [Fourth Modification]

[0146] Figure 15This is a cross-sectional view of an optical module 1D according to a fourth variant. The optical module 1D of this variant differs from the optical module 1C of the third variant in the following respects; otherwise, it is identical to the optical module 1C of the third variant. The optical module 1D of this variant includes a carrier 23C in place of the carrier 23A. Like the carrier 23 of the aforementioned embodiment, the carrier 23C has a generally rectangular parallelepiped shape, including a mounting surface 23a and a bottom surface 23b. The optical semiconductor chip 22 is mounted on the mounting surface 23a. The bottom surface 23b is opposite the first surface 11. The constituent materials of the carrier 23C are the same as those of the carrier 23 of the aforementioned embodiment.

[0147] Figure 16 2 is a perspective view showing the appearance of the carrier 23C. Figure 15 and Figure 16 As shown, the bottom surface 23b of the carrier 23C includes, in addition to the first contact surface 23ba and the second contact surface 23bb, a third contact surface 23bc with which the first adhesive 40 contacts. When viewed from the normal to the bottom surface 23b, the first contact surface 23ba is located between the second contact surface 23bb and the third contact surface 23bc. In other words, the third contact surface 23bc is located further outboard of the first contact surface 23ba and on the opposite side of the first contact surface 23ba from the second contact surface 23bb. Like the first and second contact surfaces 23ba and 23bb, the third contact surface 23bc is a flat surface. The distance D3 between the third contact surface 23bc and the first surface 11 is smaller than the distance D1 between the first contact surface 23ba and the first surface 11. In other words, the third contact surface 23bc protrudes relative to the first contact surface 23ba in the direction toward the first surface 11. That is, relative to the imaginary plane containing the first contact surface 23ba, the third contact surface 23bc is located closer to the first surface 11. Therefore, the first contact surface 23ba forms the bottom surface of the groove arranged between the second contact surface 23bb and the third contact surface 23bc. The side surface of the groove is perpendicular to the bottom surface 23b or inclined relative to the bottom surface 23b. The shape of the groove in the cross section perpendicular to the extension direction of the first contact surface 23ba is, for example, a rectangle. The cross-sectional shape of the groove is not limited to this, and various shapes such as a trapezoid or a semicircle can be applied. The width W of the groove in the direction perpendicular to the extension direction is, for example, greater than 50 μm and less than 140 μm. The depth of the groove, that is, the difference between the distance D2 and the distance D1 (D2-D1), is, for example, greater than 50 μm and less than 100 μm.

[0148] The first adhesive 40 enters the groove and contacts the inner surface of the groove. Figure 16As shown, the groove and first contact surface 23ba extend linearly along the Y direction. This allows for easy formation of the groove using, for example, a dicing blade. The ends of the groove and first contact surface 23ba reach the side surfaces 23j and 23k of the carrier 23A. Furthermore, distance D3 can be greater than, smaller than, or equal to distance D2 between the second contact surface 23bb and the first surface 11.

[0149] In this modification, the distance D2 between the second contact surface 23bb and the first surface 11 is also smaller than the distance D1 between the first contact surface 23ba and the first surface 11. Figure 17 As shown, the first adhesive 40 is prevented from spreading toward the second contact surface 23bb. Therefore, it is possible to avoid the first adhesive 40 and the second adhesive 50 from mixing on or near the bottom surface 23b, and to avoid the curing of the first adhesive 40 on or near the bottom surface 23b being hindered by the second adhesive 50.

[0150] Moreover, if Figure 17 As shown, when the cured first adhesive 40 reaches the side surface of the carrier 23C, the portion 41 of the first adhesive 40 located on the side surface of the carrier 23C and the portion 42 of the first adhesive 40 located on the first contact surface 23ba (i.e., inside the groove) sandwich a portion of the carrier 23C, i.e., the portion 231 of the carrier 23C including the third contact surface 23bc, from both sides. This improves the fixing strength between the carrier 23C and the base material 10B.

[0151] Figure 18 This is a three-dimensional diagram showing the appearance of a carrier 23D as another scheme of this modification. The difference between the carrier 23D and the carrier 23C is that the two ends of the groove with the first contact surface 23ba as the bottom surface do not reach both the side surface 23j and the side surface 23k. In other words, there is a gap between the first contact surface 23ba and the side surface 23j and the side surface 23k. Even with such a scheme, the above-mentioned effect of this modification can be obtained. However, in Figure 18 In the embodiment shown, since the groove cannot be formed using a cutting blade, the groove is formed by sandblasting or the like.

[0152] [Fifth Modification]

[0153] Figure 19This is a cross-sectional view of an optical module 1E according to a fifth variant. The optical module 1E of this variant differs from the optical module 1C of the third variant in the following respects; otherwise, it is identical to the optical module 1C of the third variant. The optical module 1E of this variant includes a carrier 23E in place of the carrier 23A. Similar to the carrier 23 of the aforementioned embodiment, the carrier 23E has a generally rectangular parallelepiped shape, with a mounting surface 23a and a bottom surface 23b. The optical semiconductor chip 22 is mounted on the mounting surface 23a. The bottom surface 23b is opposite the first surface 11. The constituent materials of the carrier 23E are the same as those of the carrier 23 of the aforementioned embodiment.

[0154] like Figure 19 As shown, the bottom surface 23b of the carrier 23E includes, in addition to the first contact surface 23ba and the second contact surface 23bb, a third contact surface 23bd for contact with the first adhesive 40. When viewed from the normal to the bottom surface 23b, the first contact surface 23ba is located between the second contact surface 23bb and the third contact surface 23bd. In other words, the third contact surface 23bd is located further outboard of the first contact surface 23ba and on the opposite side of the first contact surface 23ba from the second contact surface 23bb. Like the first and second contact surfaces 23ba and 23bb, the third contact surface 23bd is a flat surface. The distance D4 between the third contact surface 23bd and the first surface 11 is greater than the distance D1 between the first contact surface 23ba and the first surface 11. In other words, the third contact surface 23bd is recessed relative to the first contact surface 23ba in the direction toward the mounting surface 23a. That is, relative to the imaginary plane containing the first contact surface 23ba, the third contact surface 23bd is located closer to the mounting surface 23a. Therefore, a step 23i is formed between first contact surface 23ba and third contact surface 23bd. Step 23i is perpendicular to or inclined relative to bottom surface 23b. The difference between distance D4 and distance D1 (D4 - D1), i.e., the height of step 23i, is, for example, not less than 0.01 mm and not more than 0.05 mm.

[0155] In this variation, the distance D2 between the second contact surface 23bb and the first surface 11 is also smaller than the distance D1 between the first contact surface 23ba and the first surface 11. Therefore, the first adhesive 40 is prevented from spreading toward the second contact surface 23bb. Furthermore, in this variation, the distance D4 between the third contact surface 23bd and the first surface 11 is greater than the distance D1 between the first contact surface 23ba and the first surface 11. In this case, the first adhesive 40 is further blocked by the step 23i, thus more effectively preventing the first adhesive 40 from spreading toward the second contact surface 23bb. Therefore, according to this variation, the first adhesive 40 and the second adhesive 50 from mixing on or near the bottom surface 23b, as well as the curing of the first adhesive 40 on or near the bottom surface 23b being hindered by the second adhesive 50, can be more effectively prevented. Furthermore, the first adhesive 40 is further prevented from entering between the second adhesive 50 and the bottom surface 23b, further increasing the area of the second contact surface 23bb, thereby further improving heat dissipation.

[0156] The optical module and the manufacturing method of the optical module according to the present disclosure are not limited to the above-mentioned embodiments and modifications, and various other modifications are also possible. For example, the configuration of the first adhesive 40 and the second adhesive 50 is not limited to the above-mentioned embodiments and modifications. In the above-mentioned embodiments and modifications, an optical semiconductor element having an optical semiconductor chip 22 mounted on a carrier 23 is shown as an example as the optical semiconductor element 20, but the carrier 23 can also be omitted and the optical semiconductor element 20 can be constituted by a single optical semiconductor chip 22. The optical semiconductor chip 22 is not limited to a semiconductor optical amplifier (SOA), and can also be, for example, other optical semiconductor chips such as semiconductor lasers. The optical circuit element 30 is not limited to a silicon photonic chip, and can also be, for example, other optical circuit elements such as an optical waveguide substrate.

[0157] Furthermore, the third, fourth, and fifth modified examples illustrate the case where the substrate 10B having the groove 12 is used. However, the present invention is not limited to this example. In the third, fourth, and fifth modified examples, the substrate 10A of the embodiment (see Figure 1 ).

Claims

1. An optical module comprising: a base material having a first surface; An optical semiconductor element is provided on the first surface and has a first optical port on a side surface for incident light, emitted light, or both incident light and emitted light; an optical circuit element arranged on the first surface in parallel with the optical semiconductor element, and having a second optical port on a side surface thereof for inputting, outputting, or outputting light and for optically coupling with the first optical port in opposition thereto; a first adhesive mainly comprising a UV curing material and having a first thermal conductivity, disposed between the optical semiconductor element and the first surface to fix the optical semiconductor element to the first surface; as well as The second adhesive mainly includes a thermosetting material and has a second thermal conductivity higher than the first thermal conductivity. The second adhesive is disposed between the optical semiconductor element and the first surface to fix the optical semiconductor element to the first surface.

2. The optical module according to claim 1, wherein: The optical semiconductor element includes: an optical semiconductor chip having the first optical port; and A carrier carries the optical semiconductor chip, and is fixed to the first surface by the first adhesive and the second adhesive.

3. The optical module according to claim 1 or 2, wherein: The UV curing material is a UV curing resin.

4. The optical module according to any one of claims 1 to 3, wherein The thermosetting material is sintered silver.

5. The optical module according to any one of claims 1 to 3, wherein The thermosetting material is sintered silver containing epoxy resin.

6. The optical module according to any one of claims 1 to 5, wherein: The first adhesive and the second adhesive are isolated from each other on the first surface.

7. The optical module according to any one of claims 1 to 6, wherein: The base material has a recessed portion formed between the first adhesive and the second adhesive when viewed in a normal direction of the first surface.

8. The optical module according to any one of claims 1 to 7, further comprising: The third adhesive is disposed between the first optical port and the second optical port. The third adhesive mainly comprises a UV curing material having a faster curing speed than the UV curing material of the first adhesive.

9. The optical module according to any one of claims 1 to 8, wherein: A contact area between the second adhesive and the optical semiconductor element is larger than a contact area between the first adhesive and the optical semiconductor element.

10. The optical module according to any one of claims 1 to 9, wherein: The first adhesive is provided on a plurality of regions of the first surface separated by the second adhesive.

11. The optical module according to claim 10, wherein: The plurality of regions are arranged in line symmetry with respect to an axis along the first surface.

12. The optical module according to any one of claims 1 to 11, wherein: The optical semiconductor element has a bottom surface facing the first surface, The first adhesive and the second adhesive are spaced apart from each other on the bottom surface of the optical semiconductor element.

13. The optical module according to claim 2, wherein: The carrier has a bottom surface opposite to the first surface, The bottom surface includes a first contact surface for contact with the first adhesive and a second contact surface for contact with the second adhesive, A distance between the second contact surface and the first surface is smaller than a distance between the first contact surface and the first surface.

14. The optical module according to claim 13, wherein: The bottom surface also has a third contact surface for the first adhesive to contact. When viewed from the normal direction of the bottom surface, the first contact surface is located between the second contact surface and the third contact surface. A distance between the third contact surface and the first surface is smaller than a distance between the first contact surface and the first surface.

15. The optical module according to claim 13, wherein: The bottom surface also has a third contact surface for the first adhesive to contact. When viewed from the normal direction of the bottom surface, the first contact surface is located between the second contact surface and the third contact surface. The distance between the third contact surface and the first surface is greater than the distance between the first contact surface and the first surface.

16. A method for manufacturing an optical module, comprising the following steps: The optical circuit element, the first adhesive, and the second adhesive are arranged on the first surface of the base material, wherein The optical circuit element has a second optical port on a side surface for light input, output, or input and output; the first adhesive mainly comprises a UV curing material and has a first thermal conductivity; the second adhesive mainly comprises a thermosetting material and has a second thermal conductivity higher than the first thermal conductivity; An optical semiconductor element having a first optical port for incident, emitted, or both incident and emitted light on a side surface is brought into contact with the first adhesive and the second adhesive, and the optical semiconductor element is arranged so that the first optical port and the second optical port are optically coupled; holding the optical semiconductor element at a position adjusted to perform the optical coupling, and curing the first adhesive by irradiation with ultraviolet light; as well as The second adhesive is cured by heating while the first adhesive is cured.

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