Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
  • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements

Definitions

• This disclosure relates to optical waveguide packages and light source modules.
• Patent Document 1 Conventional optical waveguide packages and light source modules are described in, for example, Patent Document 1.
• the optical waveguide package according to the present disclosure comprises a substrate having a first surface and a first recess opening on the first surface, a clad located on the first surface, the clad having a second surface facing the first surface, a third surface located on the opposite side of the second surface, and an element accommodating space penetrating between the second surface and the third surface, a core located within the clad and having an entrance surface facing the element accommodating space and an exit surface exposed from an end surface of the clad, and an electrode layer located on the bottom surface of the first recess.
• the optical waveguide package comprises a substrate having a first surface and a first recess that opens on the first surface, a cladding located above the first surface, the cladding having a second surface facing the first surface, a third surface located opposite the second surface, and an opening that opens on the third surface, a core located within the cladding and having an entrance surface exposed within the opening and an exit surface exposed at an end surface of the cladding, and an electrode layer located within the opening, the opening having a bottom, the first recess having a bottom surface, the bottom surface and the bottom surface overlap in a plan view, and the electrode layer being located on the bottom.
• the optical waveguide package according to the present disclosure comprises a substrate having a first surface and a first recess opening on the first surface, a clad located above the first surface and having a sidewall, a core located within the clad and having an entrance surface exposed on the sidewall and an exit surface exposed at an end surface of the clad, and an electrode layer located on the bottom surface of the first recess, the clad being spaced from the first recess.
• the light source module comprises the optical waveguide package, a light emitting element mounted on the electrode layer of the optical waveguide package, and a lid body positioned above the light emitting element.
• FIG. 1 is an exploded perspective view showing a light source module including an optical waveguide package according to a first embodiment of the present disclosure
• FIG. 2 is a plan view showing a light source module.
• 3 is an enlarged cross-sectional view of the light source module taken along the line III-III in FIG. 2
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• 1A to 1C are diagrams for explaining a manufacturing procedure of the light source module.
• FIG. 11 is a cross-sectional view showing a configuration of a light source module according to a second embodiment of the present disclosure.
• FIG. 11 is a cross-sectional view showing a configuration of a light source module according to a third embodiment of the present disclosure.
• FIG. 11 is a cross-sectional view showing a configuration of a light source module according to a fourth embodiment of the present disclosure.
• FIG. 13 is a cross-sectional view showing a configuration of a light source module according to a fifth embodiment of the present disclosure.
• FIG. 13 is a cross-sectional view showing a configuration of a light source module according to a sixth embodiment of the present disclosure.
• FIG. 13 is a cross-sectional view showing a configuration of a light source module according to a seventh embodiment of the present disclosure.
• 13 is a cross-sectional view showing a configuration of a light source module according to an eighth embodiment of the present disclosure.
• FIG. 11 is a cross-sectional view showing a configuration of a light source module according to a third embodiment of the present disclosure.
• FIG. 11 is a cross-sectional view showing a configuration of a light
• FIG. 13 is a plan view showing the configuration of a light source module according to a ninth embodiment of the present disclosure.
• FIG. 23 is a plan view showing the configuration of a light source module according to a tenth embodiment of the present disclosure.
• a cross-sectional view showing the configuration of a light source module according to a fourteenth embodiment of the present disclosure A cross-sectional view showing the configuration of a light source module according to a fifteenth embodiment of the present disclosure.
• the light source module includes a light-emitting element and an optical waveguide layer that is made up of a clad and a core located within the clad.
• optical waveguide package and light source module of the present disclosure will be described with reference to the drawings.
• the optical waveguide package 2 and light source module 1 of the present disclosure may be used with either direction being up or down, but for convenience, in this specification, a Cartesian coordinate system X, Y, Z is defined, and the positive direction of the Z axis is up, and terms such as top surface and bottom surface are used.
• the X direction is also referred to as the width direction.
• the Y direction is also referred to as the length direction.
• the Z direction is also referred to as the thickness direction. Note that the same reference symbols are used for parts that are common to each embodiment, and duplicate explanations may be omitted.
• Fig. 1 is an exploded perspective view showing a light source module including an optical waveguide package according to a first embodiment of the present disclosure
• Fig. 2 is a plan view showing the light source module
• Fig. 3 is an enlarged cross-sectional view of the light source module taken along the section line III-III in Fig. 2.
• the light source module 1 of this embodiment includes an optical waveguide package 2 and a light emitting element 4 mounted in an element accommodating space 3 of the optical waveguide package 2.
• the optical waveguide package 2 includes a substrate 9 having a first surface 8 and a first recess 31 opening on the first surface 8, a clad 12 located on the first surface 8, the clad 12 having a second surface 10 facing the first surface 8, a third surface 11 located on the opposite side of the second surface 10, and an element accommodating space 3 penetrating the second surface 10 and the third surface 11, a core 5 located within the clad 12 and having an incident surface 13 facing the element accommodating space 3 and an exit surface 15 exposed from an end surface 14 of the clad 12, and an electrode layer 33 located on the bottom surface 32 of the first recess 31.
• the core 5 and the clad 12 constitute an optical waveguide layer 19.
• the light-emitting element 4 may be, for example, a laser diode (LD) or a Vertical Cavity Surface Emitting Laser (VCSEL).
• the light source module 1 includes a red light-emitting element 4R that emits red light, a green light-emitting element 4G that emits green light, and a blue light-emitting element 4B that emits blue light.
• the light-emitting element 4 is not limited to an LD or a VCSEL, and may be, for example, a light-emitting diode (LED).
• Each of the light-emitting elements 4R, 4G, and 4B is positioned and arranged so that the optical axis of the emission end of each color of light is located at the center of the entrance surface 13R, 13G, and 13B of the core 5.
• the substrate 9 may be, for example, an organic wiring substrate in which the dielectric layer is made of an organic material.
• the organic wiring substrate may be, for example, a printed wiring substrate, a build-up wiring substrate, or a flexible wiring substrate.
• organic materials used in organic wiring substrates include epoxy resin, polyimide resin, polyester resin, acrylic resin, phenolic resin, and fluororesin.
• the substrate 9 may also be a ceramic wiring substrate in which the dielectric layer is made of a ceramic material.
• ceramic materials used in ceramic wiring substrates include aluminum oxide sintered bodies, mullite sintered bodies, silicon carbide sintered bodies, aluminum nitride sintered bodies, and glass ceramic sintered bodies.
• the substrate 9 is a rectangular plate-shaped body in a plan view. That is, the shape of the first surface 8 of the substrate 9 is rectangular.
• the substrate 9 may be, for example, rectangular, square, or other polygonal in a plan view.
• the clad 12 is located on the first surface 8 of the substrate 9, and has an element accommodating space 3 that penetrates between the second surface 10 and the third surface 11.
• the core 5 is located within the clad 12, and has a plurality of split paths 51R, 51G, 51B at each of the incident surfaces 13R, 13G, 13B, a combining section 17 where the multiple split paths 51R, 51G, 51B meet, and an integration path 18 that extends between the combining section 17 and the exit surface 15.
• the core 5 and the clad 12 have different refractive indices, and the core 5 has a higher refractive index than the clad 12. This difference in refractive index is utilized to totally reflect light at the interface between the core 5 and the clad 12.
• the material of the core 5 is, for example, silicon oxynitride (SiON), also known as silicon oxynitride, and the clad 12 is made of silicon oxide (SiO 2 ).
• the material of the electrode layer 33 may be, for example, a single-layer structure of Al (aluminum) or a three-layer structure of Ti (titanium)/Pt (platinum)/Au (gold).
• the first recess 31 opens at a portion of the first surface 8 exposed in the element accommodating space 3 (the bottom surface of the element accommodating space 3).
• An electrode layer 33 is provided on the bottom surface of the first recess 31, and the light emitting element 4 is mounted on the electrode layer 33.
• the first recess 31 has a bottom surface 32 and an inner wall surface 34 that extends in a direction intersecting the bottom surface 32 (a direction including a Z-direction component) and surrounds the space in the first recess 31.
• the inner wall surface 34 has two flat inner wall surfaces 34a and 34b that extend in a direction perpendicular to the optical axis of the light emitted from the light emitting element 4 (X direction).
• the inner wall surface extending in the X direction has one inner wall surface 34a close to the incident surface 13 of the core 5, and the other inner wall surface 34b away from the incident surface 13.
• the inner wall surface 34 has two flat inner wall surfaces 34c that extend in a direction parallel to the optical axis of the light emitted from the light-emitting element 4 (Y direction).
• the bottom of the first recess 31 on which each light-emitting element 4R, 4G, 4B is mounted has a small thickness T2, so that the heat dissipation is high, and the heat generated by each light-emitting element 4R, 4G, 4B can be efficiently released. Even if the thickness T1 of the substrate 9 is thinned without providing the first recess 31, the heat dissipation can be improved, but the strength and rigidity of the substrate will decrease, and there is a possibility that the optical waveguide thereon will be distorted.
• the thickness of the substrate 9 is only partially thinned by providing the first recess 31, so that the decrease in strength and rigidity of the substrate 9 is suppressed, and it is possible to achieve both heat dissipation and strength.
• the optical axis can be adjusted by setting the depth of the first recess 31 (thickness T2 of the bottom of the first recess 31) according to the element height. Although the optical axis can be adjusted by adjusting the thickness of the clad 12, the thickness of the clad 12 affects the emitted light, so the adjustment range is small.
• the depth of the first recess 31 may be such that 0.4T1 ⁇ T2 ⁇ T1. If the thickness T2 of the bottom portion is within this range, it is possible to improve heat dissipation while suppressing a decrease in strength.
• the electrode layer 33 has a first electrode layer 33a and a second electrode layer 33b.
• the first electrode layer 33a is located on the bottom surface of the first recess 31, and the light-emitting element 4 is mounted on it.
• the second electrode layer 33b is connected to the first electrode layer 33a and extends from the inner wall surface 34 (34b) of the first recess 31 to the outside of the element accommodating space 3.
• the second electrode layer 33b passes between the peripheral wall portion of the optical waveguide layer 19 and the first surface 8 of the substrate 9, and extends to the exposed portion of the first surface 8 located outside the element accommodating space 3.
• the first electrode layer 33a is mainly used as an electrode pad connected to each light-emitting element 4R, 4G, 4B.
• the portion of the second electrode layer 33b located outside the element accommodating space 3 is mainly used as an external terminal electrode, and the portion between the first electrode layer 33a and the external terminal electrode portion may be used as a lead-out wiring.
• the first electrode layer 33a may be larger than one or both of the width (dimension in the X direction) and length (dimension in the Y direction) of the bottom surface 32, and may extend to the inner wall surface 34 (34a, 34b, 34c) of the first recess 31.
• the first electrode layer 33a may be smaller than one or both of the width (dimension in the X direction) and length (dimension in the Y direction) of the bottom surface 32, and a part of the bottom surface 32 may be located between the inner wall surface 34 (34a, 34b, 34c) of the first recess 31.
• the second electrode layer 33b may extend from the bottom surface 32 of the first recess 31 to the exposed part of the first surface 8 located outside the element accommodating space 3.
• the first electrode layer 33a and the second electrode layer 33b may have the same width or different widths, and the shape is not limited.
• Each lead-out wiring 61R, 61G, and 61B extends parallel to the second electrode layer 33b on the first surface 8 of the substrate 9, passes between the peripheral wall of the optical waveguide layer 19 and the first surface 8 of the substrate 9, and extends from inside the element accommodating space 3 to the outside of the element accommodating space 3.
• the portion of each lead-out wiring 61R, 61G, and 61B located outside the element accommodating space 3 may be mainly used as an external terminal electrode.
• the optical axis of the light emitted from the emission portion of each of the light-emitting elements 4R, 4G, and 4B is positioned to coincide with the center of each of the incident surfaces 13R, 13G, and 13B of the core 5.
• the thickness T2 of the bottom is determined so that the height from the surface (lower surface) 38 opposite the first surface 8 of the substrate 9 to the center of each of the incident surfaces 13R, 13G, and 13B of the core 5 coincides with the height from the lower surface 38 of the substrate 9 to the emission portion of each of the light-emitting elements 4R, 4G, and 4B.
• the bottom surface 32 is located at a position obtained by subtracting the dimension L1 from the center of each of the incident surfaces 13R, 13G, and 13B to the mounting surface of the light-emitting elements 4R, 4G, and 4B and the thickness T3 of the electrode layer 33 (first electrode layer 33a) from the height position from the lower surface 38 of the substrate 9 to the center of each of the incident surfaces 13R, 13G, and 13B. That is, the thickness T2 of the bottom portion is determined by adjusting the depth of the first recess 31 to a dimension corresponding to the thickness of each light-emitting element 4R, 4G, 4B and the thickness T3 of the electrode layer 33.
• the thickness T2 of the bottom portion of the first recess 31 of such a substrate 9 is set to 0.4T1 ⁇ T2 ⁇ T1 as described above.
• the bottom surface 32 of the first recess 31 may have a surface roughness Ra2 (Ra2>Ra1) that is greater than the surface roughness Ra1 of the first surface 8, in terms of arithmetic mean roughness.
• the surface roughness Ra2 of the bottom surface 32 of the first recess 31 is greater than the surface roughness Ra1 of the first surface 8. This improves the adhesion strength of the electrode layer 33 to the substrate 9 and suppresses the occurrence of film peeling of the electrode layer 33 when the electrode layer 33 is directly formed on the bottom surface 32.
• the contact area between the electrode layer 33 and the light-emitting element 4B increases, and the adhesion strength between the substrate 9, the electrode layer 33, and the light-emitting element 4B can be improved.
• the surface of the electrode layer 33 also has a large surface roughness, it is possible to reduce the possibility that stray light that does not enter the core 5 from the incident surface 13 will be re-reflected on the surface of the electrode layer 33 and enter the core 5. Furthermore, since the surface area of the electrode layer 33, which is most affected by thermal expansion, is increased, it is possible to improve heat dissipation and reduce the occurrence of film peeling of the electrode layer 33.
• the inner wall surface 34 surrounding the space in the first recess 31 may have a surface roughness Ra3 greater than the surface roughness Ra1 of the first surface 8. If the other inner wall surface 34b of the first recess 31 is parallel to the inner surface 19a, the thickness T5 of the electrode layer 33 on the other inner wall surface 34b is small, and a break may occur. In contrast, by making the surface roughness Ra3 of the inner wall surface 34 greater than the surface roughness Ra1 of the first surface 8, the adhesion strength between the electrode layer 33 and the inner wall surface 34 can be improved and the occurrence of film peeling can be suppressed.
• the surface roughness of the inner wall surface 34 and the surface of the electrode layer 33 thereon is also large, the possibility of stray light being re-reflected on the surface of the electrode layer 33 and entering the core 5 can be reduced. If the first electrode layer 33a of the electrode layer 33 does not extend to the inner wall surface 34 (34a, 34b, 34c) of the first recess 31, only the other inner wall surface 34b where the second electrode layer 33b is located may have a surface roughness Ra3 greater than the surface roughness Ra of the first surface 8.
• the surface roughness Ra1 of the first surface 8 may be 0.1 nm or more and 10 nm or less
• the surface roughness Ra2 of the bottom surface 32 may be 1 ⁇ m or more and 100 ⁇ m or less
• the surface roughness Ra3 of the inner wall surface 34 may be 10 ⁇ m or more and 500 ⁇ m or less.
• the example shown in FIG. 3 is an example in which the surface roughness Ra2 of the bottom surface 32 and the surface roughness Ra3 of the inner wall surface 34 are both greater than the surface roughness Ra1 of the first surface 8, but only one of the surface roughness Ra2 of the bottom surface 32 and the surface roughness Ra3 of the inner wall surface 34 may be greater than the surface roughness Ra1 of the first surface 8.
• a high-precision optical waveguide layer 19 is formed thereon.
• the above effects can be obtained more effectively, and cracks originating from the rough surface due to thermal stress, etc., are less likely to occur.
• the inner wall surface 34 surrounding the space in the first recess 31 may be flat and inclined with respect to the bottom surface 32 of the first recess 31.
• the inner wall surface 34 inclined with respect to the bottom surface 32 means that the inner wall surface 34 is not perpendicular to the bottom surface 32, and the angle between the bottom surface 32 and the inner wall surface 34 is an obtuse angle.
• the inner wall surface 34 inclined with respect to the bottom surface 32 means that the inner wall surface 34 is inclined with respect to the inner surface 19a of the optical waveguide layer 19 facing the element accommodating space 3.
• the opening edge of the first recess 31 is located outside the edge of the bottom surface 32 of the first recess 31, and the inner wall surface 34 is inclined outward from the first recess 31.
• the thickness T5 of the electrode layer 33 on the other inner wall surface 34b is small, and a break may occur.
• the thickness T5 of the electrode layer 33 can be increased, making it possible to suppress the occurrence of disconnections.
• the angle between the bottom surface 32 and the inner wall surface 34 is an obtuse angle, stress is less likely to concentrate compared to when this angle is a right angle or an acute angle, and the possibility of cracks starting from the corner occurring is reduced.
• the inclination angles of the inner wall surfaces 34a, 34b, and 34c of the first recess 31 may all be the same or different from each other.
• one inner wall surface 34a has an angle ⁇ 1 with respect to an imaginary plane including the inner surface 19a facing the element accommodating space 3 of the optical waveguide layer 19
• the other inner wall surface 34b has an angle ⁇ 2 with respect to an imaginary plane parallel to the inner surface 19a, and ⁇ 1 ⁇ 2 may be satisfied.
• the two inner wall surfaces 34c extending in the Y direction are approximately perpendicular to the bottom surface 32, and some of the inner wall surfaces 34a, 34b, and 34c may be inclined with respect to the bottom surface 32.
• the above angle ⁇ 1 may be, for example, 5° or more and 60° or less.
• the above angle ⁇ 2 may be, for example, 5° or more and 60° or less.
• the angle between the bottom surface 32 of the first recess 31 and the inner wall surfaces 34a, 34b is an obtuse angle of 95° or more and 150° or less.
• the angle ⁇ 1 of one inner wall surface 34a and the angle ⁇ 2 of the other inner wall surface 34b may be the same or different.
• the light source module 1 includes the optical waveguide package 2 described above, a focusing lens 6 located on the optical path of the light emitted from the core 5, a box-shaped lid body 7 with one side open, for example, that covers the element housing space 3, and a ring-shaped metal film 22 interposed between the lid body 7 and the cladding 12.
• the focusing lens 6 may collimate or focus the light emitted from the core 5.
• the focusing lens 6 may be, for example, a plano-convex lens with a flat entrance surface and a convex exit surface.
• the lid body 7 is not limited to a box shape, and may be, for example, a plate shape, and other different shapes can be adopted as appropriate.
• the lid body 7 may be made of a glass material such as quartz, borosilicate, or sapphire.
• the bonding material may be any material that can bond the clad 12 and the lid body 7 and hermetically seal them, and may be, for example, Au-Sn or Sn-Ag-Cu solder, metal nanoparticle paste such as Ag or Cu, or glass paste.
• the lid body 7 is hermetically bonded by the bonding material with the metal film 22 sandwiched between it and the clad 12, and therefore the element housing space 3 may be hermetically sealed from the outside.
• FIGS. 4A to 4L are diagrams for explaining an example of a manufacturing procedure for a light source module.
• a substrate 9 is prepared.
• a resist 40 is applied onto a first surface 8 of the substrate 9, and the first surface 8 is exposed from a portion where the resist 40 is not applied, and a first recess 31 is formed by an etching process, for example, by laser light irradiation.
• a bottom surface 32 of the first recess 31 is roughened by an isotropic etching process, for example, dry etching, so that the surface roughness Ra2 is greater than the surface roughness Ra1 of the first surface 8. If the surface roughness of the bottom surface 32 is sufficiently large by the etching process for forming the first recess 31, this etching process for roughening may be omitted.
• FIG. 4C after removing all the resist 40, as shown in FIG. 4D, a part of the electrode layer 33 is formed on the first surface 8, and the clad 12 is laminated halfway.
• a core layer 5a is formed, and as shown in FIG. 4F, a resist 41 for patterning is laminated on the core layer 5a.
• the core layer 6a is etched from above the resist 41 to pattern the core layer 5a, and the core 5 is formed as shown in FIG. 4G.
• FIG. 4H the clad 12 is laminated, and then a resist 42 for forming the element accommodating space 3 is laminated on the clad 12 as shown in FIG. 4I.
• the clad 12 is etched until the first surface 8 of the substrate 9 is exposed together with the bottom surface 32, and the element accommodating space 3 is formed. Then, as shown in FIG. 4K, an electrode layer 33 is formed on the exposed bottom surface 32 to form the optical waveguide package 2.
• the light emitting element 4 is mounted, for example, by flip-chip mounting on the electrode layer 33 of the optical waveguide package 2, and the opening of the element housing space 3 is closed with a lid 7 to manufacture a light source module.
• the electrode layer 33 may be formed up to the first recess 31. As described above, by forming the electrode layer 33 separately on the first surface 8 and in the first recess 31, the surface roughness in the first recess 31 can be made rougher by the etching process of FIG. 4J.
• Second Embodiment 5 is a cross-sectional view showing the configuration of a light source module according to a second embodiment of the present disclosure.
• the inner wall surface 34 of the first recess 31 of the substrate 9 is flat and connected to the bottom surface 32 via a curved surface 34a1.
• one of the inner wall surfaces 34a of the first recess 31 of the substrate 9 has a curved surface 34a1 that is curved convexly outward toward the side away from the opening of the first recess 31, that is, toward the lower left in FIG. 5, and is connected to the bottom surface 32 via the curved surface 34a1.
• all of the inner wall surfaces 34 (34a, 34b, 34c) including the other inner wall surface 34b and the other two inner wall surfaces 34c extending in the Y direction may be connected to the bottom surface 32 via the curved surface 34a1.
• the corner between the inner wall surface 34 and the bottom surface 32 may be a curved surface (concave curved surface).
• the inner wall surface 34 that is continuous with the bottom surface 32 via the curved surface 34 a 1 may be inclined with respect to the bottom surface 32 .
• the stress generated at the corners between the bottom surface 32 and the inner wall surface 34 is dispersed, reducing the occurrence of cracks originating from the corners due to stress concentration, and reducing damage to the substrate 9.
• the curved corners of the electrode layer 33 located from the bottom surface 32 to the inner wall surface 34 reduce the possibility of the electrode layer 33 breaking at the corners.
• Third Embodiment 6 is a cross-sectional view showing the configuration of a light source module according to a third embodiment of the present disclosure.
• the inner wall surface 34 of the first recess 31 of the substrate 9 is concave and is connected to the bottom surface 32 via a curved surface 34a1.
• both the one inner wall surface 34a and the other inner wall surface 34b are concave surfaces that are curved as a whole from the first surface 8 of the substrate 9 to the bottom surface 32.
• the curved surface 34a1 between the inner wall surfaces 34a, 34b and the bottom surface 32 is not clear, it can be said that the inner wall surface 34 is connected to the bottom surface 32 via the curved surface 34a1 in this case as well.
• all the inner wall surfaces 34 (34a, 34b, 34c) including the other two inner wall surfaces 34c extending in the Y direction may be connected to the bottom surface 32 via the curved surface 34a1.
• Fourth Embodiment 7 is a cross-sectional view showing the configuration of a light source module according to a fourth embodiment of the present disclosure.
• a step portion 39 is disposed between the first recess 31 and the inner surface 19a of the cladding 12 and the core 5 facing the element housing space 3.
• the step portion 39 is formed by an intersection between the first surface 8 and one of the inner wall surfaces 34a.
• the first recess 31 opens to the first surface 8 at a position away from the inner surface 19a.
• step portion 39 is provided on the inner surface 19a side of the first recess 31, it is easy to confirm the position of each of the light-emitting elements 4R, 4G, 4B relative to the step portion 39 from the underside 38 of the substrate 9, and good positioning can be obtained.
• the bottom of the first recess 31 is thin, the visibility of each of the light-emitting elements 4R, 4G, 4B can be improved when mounting the elements.
• Fifth Embodiment 8 is a cross-sectional view showing the configuration of a light source module according to a fifth embodiment of the present disclosure.
• the bottom surface 32 of the first recess 31 is deepest on the side of the incident surface 13B relative to the first surface 8, and becomes shallower as it moves away from the incident surface 13B. Therefore, the bottom surface 32 is inclined upward as it moves away from the inner surface 19a of the optical waveguide layer 19 facing the element accommodating space 3.
• the inner surface 19a of the optical waveguide layer 19 facing the element accommodating space 3 is perpendicular to the bottom surface 32 of the first recess 31 and is inclined relative to the first surface 8.
• the thickness of the bottom constituting the bottom surface 32 of the first recess 31 is reduced in thickness T2a on the side of the emission portion where the heat generated by the light emitting element 4B is greatest, improving heat dissipation, and the thickness T2b of the portion farther from the emission portion is increased in thickness, improving strength. Therefore, it is possible to achieve both improved heat dissipation and improved strength.
• Sixth Embodiment 9 is a cross-sectional view showing the configuration of a light source module according to a sixth embodiment of the present disclosure.
• the light source module 1e may include a second recess 35 further recessed from the bottom surface 32 of the first recess 31.
• the light source module 1e of this embodiment includes a second recess 35 between the light emitting element 4 and the other inner wall surface 34b away from the incident surface 13B.
• the thickness T2c of the bottom of the second recess 35 is thinner than the thickness T2 of the bottom of the first recess 31.
• the electrode layer 33 includes a first electrode layer 33a located on the bottom surface 32 closer to the incident surface 13B than the second recess 35, and a second electrode layer 33b connected to the first electrode layer 33a, passing through the second recess 35 and the inner wall surface 34 (34b) of the first recess 31, and extending to the outside of the element accommodating space 3.
• the unnecessary bonding material 47 is likely to flow into the second recess 35, so that the bonding material 47 creeps up the side of the light-emitting element 4B, and the possibility of short-circuiting between one electrode located on the lower surface of the light-emitting element 4B and the other electrode located on the upper surface can be reduced.
• the thickness T2c of the bottom of the second recess 35 is even thinner than the thickness T2 of the bottom of the first recess 31, and the second electrode layer 33b of the electrode layer 33 is located in a position close to the lower surface 38 opposite to the first surface 8 of the substrate 9.
• the heat generated by the light-emitting element 4B can be efficiently dissipated through the second electrode layer 33b located on the bottom surface of the second recess 35, and the heat dissipation can be further improved.
• the bonding material 47 with a relatively high thermal conductivity accumulates in the second recess 35, a large heat conduction path is formed between the light-emitting element 4B and the electrode layer 33, so that the heat dissipation can be improved.
• Seventh Embodiment 10 is a cross-sectional view showing the configuration of a light source module according to a seventh embodiment of the present disclosure.
• the light source module 1f of this embodiment is different from the light source module 1e of the sixth embodiment in the position of the second recess 35.
• the light source module 1f of this embodiment is provided with the second recess 35 on the incident surface 13B side of the light emitting element 4B. It can also be said that the second recess 35 is located between the light emitting element 4B and one of the inner wall surfaces 34a.
• the thickness T2c of the bottom of the second recess 35 is even thinner than the thickness T2 of the bottom of the first recess 31.
• the bottom surface 32 of the first recess 31 is not located between the second recess 35 and one of the inner wall surfaces 34a, and one of the inner wall surfaces 34a of the first recess 31 and the inner wall surface of the second recess 35 are continuous.
• the first electrode layer 33a located directly below the light emitting element 4B may extend into the second recess 35.
• the thickness of the substrate 9 becomes thinner at a position close to the emission part where the heat generation of the light-emitting element 4B is the greatest, so that the heat dissipation can be further improved.
• unnecessary bonding material 47 flows into the second recess 35, so that the bonding material 47 creeps up the side of the light-emitting element 4B, and the possibility of a short circuit between one electrode located on the lower surface of the light-emitting element 4B and the other electrode located on the upper surface can be reduced.
• the bonding material 47 does not creep up and cause a short circuit, if it creeps up to the emission part of the light-emitting element 4B, the emission of light from the light-emitting element 4B is hindered.
• the second recess 35 is located closer to the incident surface 13B than the light-emitting element 4B and is located near the emission part of the light-emitting element 4B, so that the possibility of the bonding material 47 creeping up to the side where the emission part of the light-emitting element 4B is located can be effectively reduced.
• the bonding material 47 tends to spread over the extended first electrode layer 33a, making it easier to guide unnecessary bonding material 47 into the second recess 35 and more likely to prevent bonding material 47 from creeping up the side of the light-emitting element 4B.
• heat can be transferred to the thinner part of the substrate 9 via the bonding material 47, further improving heat dissipation.
• Eighth Embodiment 11 is a cross-sectional view showing the configuration of a light source module according to an eighth embodiment of the present disclosure.
• the light source module 1g of this embodiment has a second recess 35 on the side of the light emitting element 4B facing the incident surface 13B and on the side of the light emitting element 4B facing the incident surface 13.
• the second recess 35 is provided between the light emitting element 4B (the first electrode layer 33a on which the light emitting element 4B is mounted) and one of the inner wall surfaces 34a, and between the light emitting element 4B (the first electrode layer 33a on which the light emitting element 4B is mounted) and the other inner wall surface 34b.
• the second recess 35 may also be provided between the light emitting element 4B and the other two inner wall surfaces 34c extending in the Y direction.
• the second recess 35 may be an annular groove surrounding the light emitting element 4B in a plan view.
• the second inner wall surface 35a of the second recess 35 of the light source module 1g of this embodiment is inclined in the same manner as the inner wall surface 34 of the first recess 31.
• the second inner wall surface 35a of the second recess 35 may be inclined with respect to the bottom surface of the second recess 35. This inclination is such that the angle between the second inner wall surface 35a and the bottom surface of the second recess 35 is an obtuse angle.
• the opening edge of the second recess 35 is located outside the edge of the bottom surface of the second recess 35, and the second inner wall surface 35a is inclined outward from the second recess 35.
• the angle between the second inner wall surface 35a and the bottom surface of the second recess 35 may be 95° to 150°.
• This configuration provides the same effects as those of the sixth and seventh embodiments. Furthermore, since the second inner wall surface 35a of the second recess 35 is inclined relative to the bottom surface of the second recess 35, the thickness change from the thickness T2 from the bottom surface 32 of the first recess 31 to the bottom surface 38 of the substrate 9 to the thickness T2c from the bottom surface of the second recess 35 to the bottom surface 38 of the substrate 9 becomes gradual, which disperses thermal stress and reduces the occurrence of cracks.
• the corner between the second inner wall surface 35a and the bottom surface of the second recess 35 is an obtuse angle, the stress applied to this corner and the electrode layer 33 located above this corner is dispersed, and the occurrence of cracks in the substrate 9 and the electrode layer 33 can be reduced. Furthermore, when the heat generated by the light emitting element 4 (4B) is conducted to the bottom surface 38 of the substrate 9, it is conducted while diffusing in the width direction (X direction) and length direction (Y direction) of the inclination of the second inner wall surface 35a, so that the heat dissipation efficiency is further improved.
• the corner between the bottom surface of the second recess 35 and the second inner wall surface 35a may be a curved concave surface, or the entire second inner wall surface 35a may be a curved concave surface. In this case, the effect of reducing cracks in the substrate 9 and the electrode layer 33 due to the dispersion of stress is further enhanced.
• Fig. 12 is a plan view showing a configuration of a light source module according to a ninth embodiment of the present disclosure.
• the three light emitting elements 4R, 4G, and 4B are individually accommodated in the first recess 31 in the above-described embodiments, but in this embodiment, as shown in Fig. 12, the three light emitting elements 4R, 4G, and 4B may be accommodated in one first recess 31.
• each light-emitting element 4R, 4G, 4B is improved by the thin portion of the bottom of the first recess 31 of the substrate 9. Also in this embodiment, if the bottom surface 32 of the first recess 31 has a surface roughness Ra2 that is greater than the surface roughness Ra1 of the first surface 8 of the substrate 9, the adhesion strength between the substrate and the electrode layer is improved, and peeling of the electrode layer can be reduced. Also, the characteristic configurations in the first to eighth embodiments can be applied to this embodiment.
• Tenth Embodiment 13 is a plan view showing the configuration of a light source module according to the tenth embodiment of the present disclosure.
• the same reference numerals are used for parts corresponding to the above-mentioned embodiments, and duplicated descriptions are omitted.
• the above-mentioned embodiments are configured such that the three cores 5 are integrated at the multiplexing section 17 where they meet to form one waveguide, which extends to the output end.
• the light source module 1i of the tenth embodiment is the same in that the three input surfaces 13R, 13G, and 13B are located apart from each other in accordance with the centers of the input surfaces 13R, 13G, and 13B of each core 5 (5R, 5G, and 5B) and the positions of the light emitting elements 4R, 4G, and 4B.
• the output end surfaces 15R, 15G, and 15B of the three cores 5 are located close to each other but apart from each other.
• the three cores 5 may be concentrated so as to be close to each other between each of the incident surfaces 13R, 13G, and 13B and each of the exit end faces 15R, 15G, and 15B, and may extend in parallel from there to each of the exit end faces 15R, 15G, and 15B.
• the three cores 5 do not have to be parallel, and may be arranged so that they are almost parallel and the intervals become smaller toward the exit end.
• the cores 5 may be greatly bent so as to be close to each other, and may be arranged so that the intervals become smaller toward the exit end.
• the cores 5 may be greatly bent so as to be close to each other, and may extend in parallel to each other toward the exit end.
• the intervals between the adjacent cores 5 may become smaller from the close portions toward the exit end.
• the light beams emitted from the exit end faces 15R, 15G, and 15B of each core 5 may be multiplexed by, for example, a condenser lens 6.
• the light beams emitted from each core 5 may be emitted in parallel by, for example, a condenser lens 6.
• images or the like formed by the light emitted from the three emission end faces 15R, 15G, and 15B may be synthesized by, for example, an external device.
• Eleventh Embodiment 14 is a cross-sectional view showing the configuration of a light source module according to the eleventh embodiment of the present disclosure.
• the substrate 9 has a back surface 8a located on the opposite side to the first surface 8, and the electrode layer 33 extends to the back surface 8a, which is different from the above-described embodiments.
• the electrode layer 33 does not need to be provided behind the element accommodating space 3 (i.e., in the positive direction of the X-axis), so the dimension of the light source module 1j in the X-direction can be reduced.
• the light source module 1j can be connected to a printed circuit board or the like by a conductive bonding material such as solder.
• the electrode layer 33 may have a through conductor 33c located in the substrate 9 and a back electrode 33d located on the back surface 8a.
• the through conductor 33c is located at a position overlapping the element accommodating space 3 in a plan view, but for example, the electrode layer 33 may extend to between the clad 12 and the substrate 9, and the through conductor 33c may overlap the clad 12 in a plan view.
• the optical waveguide package 2 has a plurality of wiring conductors, it is not necessary that all of the wiring conductors extend to the rear surface 8a of the substrate 9, and only some of the wiring conductors may extend to the rear surface 8a of the substrate 9.
• the rear surface electrode 33d may overlap the element accommodating space 3.
• ⁇ Twelfth embodiment> 15 is a cross-sectional view showing the configuration of a light source module according to a twelfth embodiment of the present disclosure.
• the light source module 1k according to the twelfth embodiment is different from the above-described embodiments in that it further includes an insulating film 43 located between the bottom surface 32 and the electrode layer 33.
• Examples of materials for the insulating film 43 include resin, glass, quartz, and ceramic. According to this configuration, even if the substrate 9 is made of a conductive material such as silicon, the possibility that the electrode layers 33 will short-circuit on the substrate 9 can be reduced.
• the positional relationship between the light emitting element 4 and the incident surface 13 in the Z direction can be easily adjusted by adjusting the thickness of the insulating film 43 (in other words, the dimension in the Z direction).
• the thickness of the insulating film 43 may be different for each light emitting element 4.
• the light source module 1l according to the thirteenth embodiment is different from the above-mentioned embodiments in that the clad 12 has a portion that does not penetrate from the second surface 10 to the third surface 11.
• the light source module 1l includes a substrate 9, a clad 12, a core 5, and an electrode layer 33.
• the substrate 9 has a first surface 8 and a first recess 31 that opens on the first surface 8.
• the clad 12 is located above the first surface 8.
• the clad 12 has a second surface 10 facing the first surface 8, a third surface 11 located on the opposite side of the second surface 10, and an opening 3a that opens on the third surface 11.
• the core 5 is located in the clad 12 and has an incident surface 13 exposed in the opening 3a and an exit surface 15 exposed at an end surface of the clad 12.
• the electrode layer 33 is located in the opening 3a.
• the opening 3a has a bottom 12b.
• the first recess 31 has a bottom surface 32. In a plan view, the bottom 12b and the bottom surface 32 overlap each other.
• the electrode layer 33 is located on the bottom 12b.
• At least a portion of the electrode layer 33 may be located within the first recess 31. More specifically, the dimension in the Z direction of the portion of the electrode layer 33 located at the bottom 12b may be smaller than the depth of the first recess 31 (i.e., the distance in the Z direction from the first surface 8 to the back surface 8a).
• the bottom surface 32 may have a surface roughness greater than that of the first surface 8.
• the bottom portion 12b may have a surface roughness greater than that of the first surface 8.
• the inner wall surface 34a of the first recess 31 may be flat and inclined relative to the bottom portion 12b.
• ⁇ Fourteenth embodiment> 17 is a cross-sectional view showing the configuration of a light source module according to the fourteenth embodiment of the present disclosure.
• the first recess 31 may have a second recess 35 further recessed from the bottom surface 32.
• the second recess 35 may be located between the light emitting element 4 and the incident surface 13, or may be located behind the light emitting element 4 at the opening 3a (in other words, in the positive direction of the X-axis in the drawing), or may be located between the light emitting element 4 and the incident surface 13 and behind the light emitting element 4 at the opening 3a as shown in FIG. 17.
• the cladding 12 may not be located on the bottom surface of the second recess 35.
• the bottom 12b may include a hole 12o that reaches the second surface 10.
• the first recess 31 may be exposed within the hole 12o.
• the second recess 35 may also be exposed within the hole 12o.
• ⁇ Fifteenth embodiment> 18 is a cross-sectional view showing the configuration of a light source module according to the fifteenth embodiment of the present disclosure.
• the light source module 1n according to the fifteenth embodiment differs from the above-mentioned embodiments in that the clad 12 does not include either the element accommodating space 3 or the opening 3a. That is, in the light source module 1l in which the light emitting element 4 is mounted, the light emitting element 4 faces the side wall 19b of the clad 12.
• the light source module 1l includes a substrate 9, a clad 12, a core 5, and an electrode layer 33.
• the substrate 9 has a first surface 8 and a first recess 31 that opens on the first surface 8.
• the clad 12 is located above the first surface 8 and has a side wall 19b.
• the core 5 is located in the clad 12.
• the core 5 also has an incident surface 13 exposed to the side wall 19b and an exit surface 15 exposed to the end surface of the clad.
• the electrode layer 33 is located on the bottom surface 32 of the first recess 31.
• the cladding 12 is spaced from the first recess 31. With this configuration, the positional relationship in the Z direction between the light emitting element 4 and the incident surface 13 can be easily adjusted by adjusting the depth of the first recess 31.
• an insulating film 43 located between the bottom surface 32 and the electrode layer 33 may be further provided.
• the optical waveguide package 2 in each embodiment includes a light-emitting element 4 mounted on the electrode layer 33 and a lid body 7 positioned above the light-emitting element 4.
• This disclosure makes it possible to provide an optical waveguide package and a light source module that can improve heat dissipation and reduce damage to the substrate.
• optical waveguide package according to the present disclosure can be implemented in the following aspects (1) to (19).
• a substrate having a first surface and a first recess opening onto the first surface; a clad located on the first surface, the clad having a second surface facing the first surface, a third surface located on the opposite side of the second surface, and an element accommodating space penetrating between the second surface and the third surface; a core located within the cladding and having an entrance surface facing the element accommodating space and an exit surface exposed from an end surface of the cladding;
• the waveguide package includes an electrode layer located on a bottom surface of the first recess.
• An optical waveguide package according to any one of the above aspects (1) to (5), further including a step portion disposed between the first recess and the inner surfaces of the cladding and the core facing the element housing space.
• a substrate having a first surface and a first recess opening on the first surface; a clad located above the first surface, the clad having a second surface facing the first surface, a third surface located on the opposite side to the second surface, and an opening opening into the third surface; a core located within the cladding, the core having an entrance surface exposed within the opening and an exit surface exposed at an end surface of the cladding; an electrode layer located within the opening;
• the opening has a bottom.
• the first recess has a bottom surface, The bottom portion and the bottom surface overlap each other in a plan view, The electrode layer is located on the bottom.
• the bottom portion includes a hole reaching the second surface,
• a substrate having a first surface and a first recess opening on the first surface; a cladding located above the first surface and having a sidewall; a core located within the cladding, the core having an entrance surface exposed to the side wall and an exit surface exposed to an end surface of the cladding; an electrode layer located on a bottom surface of the first recess; The cladding is spaced from the first recess.
• optical waveguide package according to aspect (1) above further comprising an insulating film located between the bottom surface and the electrode layer.
• the light source module according to the present disclosure can be implemented in the following manner (20):
• An optical waveguide package according to any one of the above aspects (1), (11), or (18); a light emitting element mounted on the electrode layer of the optical waveguide package; and a lid body located above the light emitting element.

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• 2024
  • 2024-03-28 JP JP2025511230A patent/JPWO2024204657A1/ja active Pending
  • 2024-03-28 WO PCT/JP2024/012912 patent/WO2024204657A1/ja not_active Ceased
  • 2024-03-28 TW TW113111882A patent/TW202445191A/zh unknown

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