JP7193426B2 - Optical waveguide module and light source module - Google Patents

Description

The present disclosure relates to optical waveguide modules and light source modules.

2. Description of the Related Art Conventionally, an optical waveguide module in which an optical waveguide and a light emitting element mounting portion are provided on a base substrate, and a light source module in which a light emitting element is mounted on the optical waveguide module have been used.
Patent Documents 1 to 3 describe inventions designed to connect the optical paths of two optical elements arranged on a substrate.

Japanese Patent Application Laid-Open No. 2007-133011 Japanese Patent Application Laid-Open No. 2001-298199 Japanese Patent No. 6196583

Consider connecting an optical path of a light-emitting element mounted on a base substrate to an incident end surface of a core of an optical waveguide laminated on the base substrate. At this time, it is necessary to align the height of the light emitting portion of the light emitting element with the incident end surface of the core.
In that case, it is desired that the light-emitting element mounting portion be configured without newly introducing a special material or a complicated structure.
In addition, it is desired that the light emitting element can be stably and easily mounted with high positional accuracy without requiring difficult positional adjustment work.

An optical waveguide module according to one aspect of the present disclosure includes a base substrate, an optical waveguide positioned on the base substrate, and a light-emitting element mounting portion for mounting a light-emitting element, wherein the optical waveguide is mounted on the base substrate. It has a laminated portion in which a first lower clad layer, a core having an incident end surface, and an upper clad layer are laminated in order from the substrate in the lamination direction, and a second lower clad layer positioned on the underlying substrate. , and an extension portion extending from the side surface of the lamination portion in the direction of the lamination surface, and the first lower clad layer of the lamination portion is a first clad layer laminated in order from the base substrate. and a second layer, wherein the second lower clad layer of the extension is connected to the first layer of the first lower clad layer, and the second The thickness of the lower clad layer of is substantially the same as the thickness of the first layer, the side surface of the laminated portion includes the incident end surface, the light emitting element has a light emitting portion on the side surface, and the The light-emitting element mounting portion has a mounting surface that abuts on the lower surface of the light-emitting element, and the mounting surface is located on all or part of the upper surface of the extension . A height range from the lower surface of the light emitting element to the light emitting portion is within a height range from the mounting surface to the incident end surface of the core, and the lower surface of the light emitting element is abutted and fixed to the mounting surface. The optical path of the light emitting element is connected to the incident end face of the core in the closed state.

A light source module according to one aspect of the present disclosure includes the optical waveguide module described above and a light emitting element having a lower surface and an optical path. is equal to or less than the distance from the mounting surface to the incident end surface of the core, and the light emitting element is configured such that the lower surface is in contact with the mounting surface and the optical path is connected to the incident end surface of the core. Implemented in the implementation part.

According to the optical waveguide module of the present disclosure, since the position regulation structure of the light emitting element can be configured by the lower cladding layer, it is easy to do without introducing a new special material or complicated structure and without requiring difficult position adjustment work. In addition, the light emitting element can be stably mounted with high positional accuracy.

According to the light source module of the present disclosure, it is possible to realize a light source module with high propagation efficiency at low cost.

1 is a cross-sectional view of a light source module according to a first embodiment of the present disclosure; FIG. 1 is a plan view of a light source module according to a first embodiment of the present disclosure; FIG. FIG. 5 is a cross-sectional view of a light source module according to a second embodiment of the present disclosure; FIG. 4 is a plan view of a light source module according to a second embodiment of the present disclosure; FIG. 5 is a cross-sectional view of a light source module according to a third embodiment of the present disclosure; FIG. 11 is a plan view of a light source module according to a third embodiment of the present disclosure; FIG. 11 is a cross-sectional view of a light source module according to a fourth embodiment of the present disclosure; FIG. 11 is a plan view of a light source module according to a fourth embodiment of the present disclosure; FIG. 11 is a cross-sectional view of a light source module according to a fifth embodiment of the present disclosure; FIG. 11 is a plan view of a light source module according to a fifth embodiment of the present disclosure; It is supplementary drawing regarding a light emitting element mounting part.

Embodiments of the present disclosure will be described with reference to the drawings. It should be noted that terms such as "upper surface" and "lower surface" that refer to the upper and lower sides are simply terms that refer to the base substrate side downward, and do not specify the arrangement when using the modules described below.

[First Embodiment]
First, the optical waveguide module 201 of the first embodiment of the present disclosure and the RGB light source module 101 including the optical waveguide module 201 will be described.
As shown in FIGS. 1, 2 and 11, the RGB light source module 101 of this embodiment comprises an optical waveguide module 201 and light emitting elements 301-303.
The optical waveguide module 201 includes a base substrate 1, an optical waveguide 100 positioned on the base substrate 1, and light emitting element mounting portions 301M-303M for mounting light emitting elements 301-303. The optical waveguide 100 includes, in order from the base substrate 1, a lower clad layer 10 laminated, a core 20 laminated in a partial region on the lower clad layer 10 (first lower clad layer 111), and the lower clad layer 10. (first lower clad layer 111)) and an upper clad layer 30 laminated on the core 20, and the core 20 includes an incident end surface 20a for incident light. The lower clad layer 10 has a first lower clad layer 111 and a second lower clad layer 112 . In addition, the first lower clad layer 111 of the laminated part 50 includes a first layer (a part of the lower part 11 of the lower clad layer) and a second layer (an upper part 12 of the lower clad layer) laminated in order from the base substrate 1. The second lower clad layer 112 of the extension portion 11 a described later may be connected to the first layer of the first lower clad layer 111 . Also, the thickness of the second lower clad layer 112 of the extending portion 11a may be substantially the same as the thickness of the first layer. Also, the thickness of the second lower clad layer 112 of the extension portion 11 a may be substantially the same as the thickness of the first lower clad layer 111 . Note that the first lower clad layer 111 and the second lower clad layer 112 will be collectively referred to as the lower clad layer 10 hereinafter.
The RGB light source module 101 includes a red (R) light emitting element 301 , a green (G) light emitting element 302 , a blue (B) light emitting element 303 , and an emission optical system 401 .
The light-emitting elements 301, 302, and 303 may be edge-emitting light-emitting elements such as LDs (Laser Diodes) and LEDs (Light Emitting Diodes).

The optical waveguide module 201 also includes wiring members 41 laid on the underlying substrate 1 .
The figure shows light emitting elements 301 to 303 mounted on light emitting element mounting portions 301M to 303M. Light emitting elements 301 to 303 are bonded to the upper surface of wiring material 41 via bonding material 42 such as solder.

The lower clad layer 10 has an extension 11a. The extending portion 11 a extends in the stacking surface direction from a side surface 51 of the stacking portion 50 positioned above the extending portion 11 a in the stacking direction. The stacking direction is the Z direction, and the stacking surface directions are the X and Y directions.
In the light emitting element mounting portions 301M to 303M, the mounting surface 11b that contacts the lower surfaces of the light emitting elements 301 to 303 to regulate the positions in the stacking direction is all or part of the upper surface of the extension portion 11a. In this embodiment, the mounting surface 11b is a part of the upper surface of the extending portion 11a.
The incident end surface 20a of the core 20 is arranged at a predetermined height from the mounting surface 11b.
In this embodiment, the extending portion 11a is the lower portion 11 when the lower clad layer 10 is divided into the upper portion 12 and the lower portion 11 at a predetermined position in the stacking direction.

The optical waveguide module 201 has a groove portion 11c that opens to the upper surface of the extension portion 11a. The mounting surface 11b is all or part of the upper surface around the opening of the groove 11c.
The wiring material 41 is bonded to the electrodes on the lower surfaces of the light emitting elements 301 to 303 via the bonding material 42 . As a result, the light emitting elements 301 to 303 are mechanically fixed and electrically connected to the optical waveguide module 201 .
This wiring member 41 is arranged at the bottom of the groove portion 11c.

The range of height from the lower surface of each of the light emitting elements 301 to 303 to the light emitting portion 61 of the corresponding light emitting element 301 to 303 is within the range of the height of the incident end surface 20a of the core 20 from the mounting surface 11b. In other words, the distance from the bottom surface of the light emitting elements 301 to 303 to the light emitting portions 61 of the light emitting elements 301 to 303 is less than or equal to the distance from the mounting surface 11b to the incident end surface 20a of the core 20 in the stacking direction.
The light emitting elements 301 to 303 are mounted on the light emitting element mounting portions 301M to 303M with their lower surfaces abutting and fixed to the mounting surface 11b and optical paths connected to the incident end surface 20a of the core 20. FIG.
The electrodes on the lower surfaces of the light emitting elements 301 to 303 and the wiring member 41 are joined together via a jointing member 42 arranged in a gap caused by the drop between the mounting surface 11b and the upper surface of the wiring member 41. FIG.
As shown in FIG. 2, wirings 301a-303a are connected to the electrodes on the upper surfaces of the light-emitting elements 301-303. Electrodes on the lower surfaces of the light emitting elements 301 to 303 are led out by wirings 301b to 303b through the wiring material 41. FIG. The wirings 301a-303a and the wirings 301b-303b are connected to a driving circuit (not shown), and the light-emitting elements 301-303 can be driven to emit light.

The flatness of the mounting surface 11b is higher than the flatness of the underlying substrate 1 . This can be easily achieved by forming the clad layers 10 and 30 and the core 20 by CVD, flame deposition, or the like. By absorbing the unevenness of the upper surface of the base substrate 1 and depositing the constituent material of the lower clad layer 10 , the flatness of the mounting surface 11 b becomes higher than the flatness of the base substrate 1 .
After forming the lower cladding layer 10 up to the lower portion 11, the upper portion 12 may be formed on a region other than the extension portion 11a to realize the flatness of the mounting surface 11b. Further, after forming the lower clad layer 10, the mounting surface 11b may be formed by etching back the upper portion 12 to realize the flatness of the mounting surface 11b.

According to the above configuration, the height positions of the lower surfaces of the light emitting elements 301 to 303 are determined by the mounting surface 11b regardless of the amount of the bonding material 42 being varied. That is, since the position regulating structure of the light emitting elements 301 to 303 can be configured by the lower clad layer 10, the light emitting elements can be easily manufactured without newly introducing a special material or a complicated structure and without requiring difficult position adjustment work. 301-303 can be stably mounted with high positional accuracy. Therefore, it is possible to reduce the optical loss in the connection between the light emitting elements 301 to 303 and the core 20, and to construct a light source module with high propagation efficiency at low cost.
Note that the groove portion 11c may not be provided when electrodes are arranged on the side surfaces of the light emitting element. Even in that case, the lower surfaces of the light emitting elements 301 to 303 are placed in contact with the mounting surface 11b to regulate the positions thereof, so that the height positions of the lower surfaces of the light emitting elements 301 to 303 are determined by the mounting surface 11b, and the same effect can be obtained. be done.

Further, according to the above configuration, since the flatness of the mounting surface 11b is higher than the flatness of the underlying substrate 1, it is possible to accurately suppress variations in tilts during mounting of the light emitting elements 301-303.

Further, according to the above configuration, the extending portion 11a is the lower portion 11 when the lower clad layer 10 is divided into the upper portion 12 and the lower portion 11 at a predetermined position in the stacking direction. The thickness can be arbitrarily selected, and the corresponding force for aligning the light emitting portions 61 of the light emitting elements 301 to 303 with the incident end surface 20a of the core 20 is large.

By abutting the front surfaces of the light emitting elements 301 to 303 having the light emitting portions 61 against the side surfaces 51 of the laminated portion 50, the mounting positions in the direction of the optical axis (X) can be determined. That is, the side surface 51 including the incident end surface 20a of the core 20 constitutes a front restricting surface that abuts against the surface having the light emitting portion 61 of the light emitting elements 301 to 303 and restricts the position in the lamination surface direction (X). .

The description of other parts is as follows.
The constituent material of the optical waveguides (10, 20, 30) may be, for example, glass such as quartz, resin, or the like. Both the materials forming the core 20 and the clads 10 and 30 may be glass or resin, or one may be glass and the other resin. In this case, the core 20 and the clads 10 and 30 have different refractive indices, and the core 20 should preferably have a higher refractive index than the clads 10 and 30 . This difference in refractive index is used to cause total reflection of light. In other words, if a path is made of a material with a high refractive index and surrounded by a material with a low refractive index, light can be confined in the path with a high refractive index.
The core 20 includes a plurality of split paths, one end of which is the incident end face 20a, and a combining portion where the plurality of split paths meet, A multiplexing path is formed which is connected through an integration path whose one end is the output end face 20b.
The configuration of the multiplexing path, the application of the three-color light-emitting elements, and the like described above are merely specific examples for explanation, and the optical waveguide module and the light source module of the present disclosure are not limited to this.

[Second embodiment]
Next, the optical waveguide module 202 of the second embodiment of the present disclosure and the RGB light source module 102 including the optical waveguide module 202 will be described. This embodiment is different from the above-described first embodiment in the following points, and is otherwise carried out in the same manner as the above-described first embodiment.
As shown in FIGS. 3 and 4, in the optical waveguide module 202 of this embodiment, the layer thickness of the extending portion 11a is the entire layer thickness of the lower clad layer 10. As shown in FIG.
In this manner, the thickness of the extending portion 11a may be selected to be the entire thickness of the lower clad layer 10 . Therefore, it is not necessary to form the lower clad layer 10 in two stages, which simplifies the structure and the formation process.
Also, in this embodiment, the light emitting portions 61 of the light emitting elements 301-303 are closer to the bottom surface of the light emitting elements than to the top surface of the light emitting elements. As a result, variations in the height of the light emitting section 61 from the mounting surface 11b can be suppressed.

[Third Embodiment]
Next, the optical waveguide module 203 of the third embodiment of the present disclosure and the RGB light source module 103 including the optical waveguide module 203 will be described. The present embodiment differs from the above-described first embodiment in the following points, and is otherwise carried out in the same manner as the above-described first embodiment.
As shown in FIGS. 5 and 6, in the optical waveguide module 203 of this embodiment, the light emitting element mounting portions 301M to 303M are in contact with the opposite surface of the light emitting elements 301 to 303 having the light emitting portion 61. It has a rear restricting surface 71 that restricts the position in the stacking surface direction (X). The rear restricting surface 71 is formed of a side surface (71) of the laminated portion 70 which is located in a surface area substantially perpendicular to the lamination surface direction of the side surfaces of the laminated portion 70 and which is higher in the lamination direction than the extending portion 11a.
In the first and second embodiments, the front restricting surface 51 is the only surface that restricts the light emitting elements 301 to 303 in the X direction. On the other hand, according to this embodiment, since there are the front restricting surface 51 and the rear restricting surface 71, these two surfaces 51, 71 can positionally restrict the light emitting elements 301 to 303 so as to sandwich them in the X direction. Therefore, the positioning of the light emitting elements 301 to 303 in the X direction is easy, and the bonding process using the bonding material 42 can be performed while the positions of the light emitting elements 301 to 303 in the X and Z directions are stabilized. This improves the mounting position accuracy of the light emitting elements 301-303.
It is optional whether the entire thickness of the lower clad layer is applied as the extending portion 11a or a part of the thickness is applied (the same applies to the fourth and fifth embodiments).

[Fourth Embodiment]
Next, the optical waveguide module 204 of the fourth embodiment of the present disclosure and the RGB light source module 104 including the optical waveguide module 204 will be described. This embodiment is different from the above-described third embodiment in the following points, and is otherwise carried out in the same manner as the above-described third embodiment.
As shown in FIGS. 7 and 8, in the optical waveguide module 204 of this embodiment, the light emitting element mounting portions 301M to 303M are in contact with the side surfaces of the light emitting elements 301 to 303 adjacent to the surface having the light emitting portion 61. It has side regulating surfaces 72 for regulating the position in the stacking direction (Z) and in the direction (Y) perpendicular to the optical axis direction X of the light emitting element. The side regulating surface 72 is located in a surface region of the side surfaces of the laminated portion 70 substantially parallel to the lamination direction and the optical axis direction of the light emitting elements 301 to 303, and is positioned above the extension portion 11a in the lamination direction. The sides (72) of the
In the third embodiment, there is no surface for restricting the position of the light emitting elements 301-303 in the Y direction. On the other hand, according to this embodiment, in addition to the front restricting surface 51 and the rear restricting surface 71, a pair of side restricting surfaces 72, 72 are provided to restrict the positions of the light emitting elements 301 to 303 so as to sandwich them in the Y direction. The positions of the light emitting elements 301 to 303 can be regulated so as to sandwich the light emitting elements 301 to 303 in the Y direction. Therefore, it is easy to position the light emitting elements 301 to 303 in the X direction and the Y direction, and the bonding process using the bonding material 42 can be performed while the positions of the light emitting elements 301 to 303 in the X direction, the Y direction, and the Z direction are stabilized. can be implemented. This improves the mounting position accuracy of the light emitting elements 301-303.

[Fifth embodiment]
Next, the optical waveguide module 205 of the fifth embodiment of the present disclosure and the RGB light source module 105 including the optical waveguide module 205 will be described. The present embodiment differs from the above fourth embodiment in the following points, and is otherwise carried out in the same manner as the above fourth embodiment.
As shown in FIGS. 9 and 10, in the optical waveguide module 205 of the present embodiment, the light emitting element mounting portions 301M to 303M have side regulating surfaces 52 in addition to the side regulating surfaces 72 .
Here, the side regulation surface 72 regulates the side surfaces at the rear end portions of the light emitting elements 301-303. The side restraint surfaces 52 added in this embodiment restrain the sides at the front ends of the light emitting elements 301-303.
The side regulating surface 52 is formed by a side surface (52) of the laminated portion 50 located above the extending portion 11a in the lamination direction.
According to this embodiment, the positional accuracy and stability of the light emitting elements 301 to 303 in the Y direction are further improved as compared with the fourth embodiment.

Although the embodiment of the present disclosure has been described above, this embodiment is shown as an example, and can be implemented in various other forms. , can be replaced and changed.
Any one or more of the front regulating surface 51, the rear regulating surface 71, the side regulating surface 52, and the side regulating surface 72 can be selected and any combination thereof can be implemented.
In the above-described embodiment, the lateral regulation surface 52 and the lateral regulation surface 72 are separated, but the lateral regulation surface 52 and the lateral regulation surface 72 may be configured as one continuous surface.
The extending portion 11a is a portion projecting in the stacking plane direction from the stacking portions (50, 70) positioned above in the stacking direction. It may be separated into parts. The extending portions 11a may be integrally connected as long as an opening for connecting to the wiring member 41 on the underlying substrate 1 can be secured. In addition, if the wiring connection structure to the light emitting elements 301 to 303 does not pass through the wiring material on the base substrate 1, the extending portion 11a may be integrally connected, or may have no opening. may

1 base substrate 10 lower clad layer 11 lower clad layer 111 first lower clad layer 112 second lower clad layer 11a extension 11b mounting surface 11c groove 12 upper portion of lower clad layer 20 core 20a incident end surface 20b exit end surface 30 Upper clad layer 41 Wiring material 42 Joining material 50 Laminated part 51 Side surface (front restricting surface)
52 Side regulating surface 61 Light-emitting portion 70 Laminated portion 71 Rear regulating surface 72 Side regulating surface 100 Optical waveguide 101 RGB light source module 102 RGB light source module 103 RGB light source module 104 RGB light source module 105 RGB light source module 201 Optical waveguide module 202 Optical waveguide Module 203 Optical waveguide module 204 Optical waveguide module 205 Optical waveguide modules 301, 302, 303 Light emitting elements 301M to 303M Light emitting element mounting portion

Claims (9)

an underlying substrate;
an optical waveguide located on the underlying substrate;
and a light-emitting element mounting portion for mounting the light-emitting element,
The optical waveguide is
a laminated portion in which a first lower clad layer, a core having an incident end face, and an upper clad layer are laminated in the lamination direction in order from the base substrate;
a second lower cladding layer positioned on the base substrate, and an extension part extending from the side surface of the lamination part in the direction of the lamination plane,
The first lower cladding layer of the laminated portion has a first layer and a second layer laminated in order from the base substrate,
The second lower clad layer of the extension is connected to the first layer of the first lower clad layer,
The thickness of the second lower clad layer of the extending portion is substantially the same as the thickness of the first layer,
the side surface of the laminated portion includes the incident end surface;
The light emitting element has a light emitting part on its side surface,
The light emitting element mounting portion has a mounting surface that contacts the lower surface of the light emitting element,
The mounting surface is located on all or part of the upper surface of the extension ,
In the stacking direction, the range of height from the lower surface of the light emitting element to the light emitting section is within the range of the height of the incident end surface of the core from the mounting surface,
An optical waveguide module configured such that an optical path of the light-emitting element is connected to an incident end face of the core in a state where the lower surface of the light-emitting element is fixed to the mounting surface in contact with the mounting surface . It further comprises a wiring material that joins with the electrode of the light emitting element,
The extending portion has a groove opening to the upper surface,
the mounting surface is located on the upper surface of the extension part on all or part of the periphery of the opening of the groove part,
2. The optical waveguide module according to claim 1, wherein the wiring material is arranged on the bottom of the groove. The light-emitting element mounting portion further has a front restricting surface that abuts on the surface of the light-emitting element having the light-emitting portion,
3. The optical waveguide module according to claim 1, wherein the front restricting surface is positioned on the side surface including the incident end surface of the core. The light-emitting element mounting portion further has a rear restricting surface that abuts against a surface of the light-emitting element opposite to the surface having the light-emitting portion,
4. The optical waveguide module according to any one of claims 1 to 3 , wherein the rear regulating surface is located in a surface region of the side surface of the lamination portion substantially perpendicular to the direction of the lamination surface. The light-emitting element mounting portion further has a side regulating surface that contacts a side surface of the light-emitting element adjacent to the surface having the light-emitting portion,
5. The side regulating surface according to any one of claims 1 to 4 , wherein the side regulating surface is located in a surface region of the side surface of the lamination portion that is substantially parallel to the lamination direction and the optical axis direction of the light emitting element. optical waveguide module. 6. The optical waveguide module according to claim 1 , wherein the flatness of the mounting surface is higher than the flatness of the underlying substrate. An optical waveguide module according to any one of claims 1 to 6 , and a light emitting element having a lower surface and an optical path,
In the stacking direction, the distance from the lower surface of the light emitting element to the light emitting portion of the light emitting element is set to be equal to or less than the distance from the mounting surface to the incident end surface of the core,
A light source module in which the light emitting element is mounted on the light emitting element mounting portion with the lower surface abutting against the mounting surface and the optical path being connected to the incident end surface of the core. An optical waveguide module according to claim 2, and a light-emitting element having an upper surface, a lower surface, an optical path, and an electrode located on the lower surface,
In the stacking direction, the distance from the lower surface of the light emitting element to the light emitting portion of the light emitting element is set to be equal to or less than the distance from the mounting surface to the incident end surface of the core,
the light emitting element is mounted on the light emitting element mounting portion with the lower surface in contact with the mounting surface and the optical path connected to the incident end surface of the core;
A light source module, wherein the electrode of the light emitting element and the wiring member are bonded via a bonding material disposed between the mounting surface and the upper surface of the wiring member. the light-emitting portion of the light-emitting element is positioned closer to the bottom surface of the light-emitting element than the top surface of the light-emitting element;
9. The light source module according to claim 7 , wherein the lower surface is in contact with the mounting surface.

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