Optical device, method of mounting electronic components

Abstract

The present application provides an optical device capable of reliably connecting a wiring arranged along one side of a substrate and a connection terminal of an electronic component vertically extended with respect to the one side of the substrate without connection failure, and a mounting method of the electronic component. An optical device has a laminated substrate with a plurality of functional layers laminated, and an optical component and an electronic component arranged on the laminated substrate, the functional layers having at least a first functional layer on which the optical component is placed, and a second functional layer arranged on a lower layer than the first functional layer and on which the electronic component is placed, a first wiring provided on one side of the first functional layer, a second wiring provided on one side of the second functional layer, and a connection terminal of the electronic component electrically connected to both the first wiring and the second wiring via a conductive material.

Description

Technical Field

[0001] This invention relates to a method for mounting optical devices and electronic components. Background Technology

[0002] In recent years, augmented reality (AR) glasses and small projectors have attracted much attention, as have small planar lightwave circuits (PLCs) using laser diodes. These laser diodes are capable of rendering images with high energy efficiency.

[0003] For example, Patent Document 1 describes a light source with a monitoring function that can be used in a small projector. The light source with a monitoring function described in Patent Document 1 has a detection element using a semiconductor photodiode (PD). The semiconductor photodiode monitors the light output. Based on the monitoring results of the light output, the light source with a monitoring function described in Patent Document 1 adjusts the white balance.

[0004] Semiconductor photodiodes come in various types, including axially leaded (CAN) type and surface-mount (SMD) type. When housing a semiconductor photodiode within a small package of an optical device (light source module) with monitoring capabilities, the CAN type is physically large and unsuitable for miniaturization; therefore, the SMD type is used.

[0005] SMD type semiconductor photodiodes are typically rectangular in shape with a light-receiving surface on one side and a connection terminal (electrode terminal) on the opposite side. When the optical axis of the incident light is along one side of the mounting substrate, this type of SMD semiconductor photodiode is mounted with the light-receiving surface or connection terminal perpendicular to one side of the mounting substrate.

[0006] When the aforementioned semiconductor photodiode is mounted on one side of a mounting substrate, in order to electrically connect the wiring pattern extending along one side of the mounting substrate and the connection terminals extending vertically relative to one side of the mounting substrate, a conductive material is formed, for example, by using a conductive resin such as silver paste to fill these gaps.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2018-180513 Summary of the Invention

[0010] However, the conductive material that electrically connects the wiring pattern and the connection terminal of the semiconductor photodiode is fluid during formation, so the cross-section decreases as the shape increases towards the top, such as a cone shape, resulting in a smaller contact area between the semiconductor photodiode and the connection terminal. Therefore, there is a technical problem where poor electrical connection can easily occur between the wiring pattern on the mounting substrate and the connection terminal of the semiconductor photodiode.

[0011] The present invention was created with this in mind, and its object is to provide a method for mounting optical devices and electronic components that enables reliable connection of wiring arranged along one side of a substrate and connection terminals of electronic components extending perpendicularly to one side of the substrate without poor connection.

[0012] An optical device according to one embodiment of the present invention includes a multilayer substrate having multiple functional layers, and an optical component and an electronic component disposed on the multilayer substrate. The functional layers include at least a first functional layer for mounting the optical component and a second functional layer disposed below the first functional layer for mounting the electronic component. A first wiring is provided on one side of the first functional layer, and a second wiring is provided on one side of the second functional layer. The connection terminals of the electronic component are electrically connected to both the first wiring and the second wiring via a conductive material.

[0013] According to the present invention, even if the connection terminals of the electronic components are installed in a manner that extends perpendicularly to the extension direction of the second wiring extending along one side of the mounting surface, i.e., the second functional layer, poor connection of the connection terminals of the electronic components can be prevented. That is, by connecting both the first wiring and the second wiring, which have the same function, to the connection terminals via conductive material, reliable conduction of the connection terminals can be achieved.

[0014] In another embodiment of the present invention, it is preferable that the first wiring and the second wiring are electrically connected by interlayer connection wiring disposed on the laminated substrate.

[0015] Alternatively, in one embodiment of the present invention, a component mounting hole penetrating the first functional layer may be formed in the first functional layer, and the electronic component may be mounted in the component mounting hole.

[0016] Alternatively, in one embodiment of the present invention, the conductive material may be located between the inner circumferential surface of the component mounting hole and the connecting terminal.

[0017] Alternatively, in one embodiment of the present invention, the end of the first wiring may be located at a position that is recessed from the inner circumferential surface of the component mounting hole.

[0018] Alternatively, in one embodiment of the present invention, an electrode recess cut out in the direction that expands the component mounting hole may be formed at a position adjacent to the end of the wiring in the first functional layer.

[0019] Alternatively, in one embodiment of the present invention, a component mounting recess that is recessed in the thickness direction may be formed in the area exposed from the component mounting hole in the second functional layer, and a component fixing resin layer that fills the interior of the component mounting recess and is in contact with at least the bottom of the electronic component may be formed.

[0020] Alternatively, in one embodiment of the present invention, the conductive material may be a conductive resin.

[0021] Alternatively, in one embodiment of the present invention, the electronic component may be a light-receiving element, and the optical component may include an optical waveguide, such that the light-receiving element receives at least a portion of the light propagating in the optical waveguide.

[0022] An embodiment of the present invention discloses a method for mounting an electronic component in a multilayer substrate. The multilayer substrate has at least a first functional layer having a first wiring on one side, a second functional layer disposed below the first functional layer and having a second wiring on one side, and a component mounting hole penetrating the first functional layer and exposing one side of the second functional layer. The mounting method includes at least: a mounting step of inserting the electronic component into the component mounting hole and positioning the electronic component on one side of the second functional layer; and a connection step of providing a conductive material between a connection terminal of the electronic component and the first wiring and the second wiring and making an electrical connection.

[0023] Alternatively, in one embodiment of the present invention, the connection process may be a process in which conductive resin is used as the conductive material, and the conductive resin is filled between the connection terminal and the inner peripheral surface of the component mounting hole, thereby electrically connecting one connection terminal of the electronic component to the first wiring and the second wiring.

[0024] According to the present invention, a method for mounting optical devices and electronic components is provided, which enables reliable connection of wiring arranged along one side of a substrate and connection terminals of electronic components extending vertically relative to one side of the substrate without connection defects. Attached Figure Description

[0025] Figure 1 This is a perspective view showing the interior of the optical device according to the first embodiment of the present invention as viewed from above.

[0026] Figure 2 It means to observe from above. Figure 1 A top view of the interior of the optical device.

[0027] Figure 3 It is along Figure 2 A cross-sectional view of the laminated substrate of the optical device that forms the A-A' line.

[0028] Figure 4 It is an enlarged 3D view showing the main parts of the mounting section of the electronic components.

[0029] Figure 5 This is an enlarged cross-sectional view showing the main parts of the mounting section of the electronic components.

[0030] Figure 6 It means equivalent to along Figure 2 A cross-sectional view of the light source unit (optical device) of the second embodiment, showing the position of the A-A' line.

[0031] Figure 7 It is an enlarged 3D view showing the main parts of the mounting section of the electronic components.

[0032] Figure 8 This is an enlarged perspective view of the main part of the mounting portion of the electronic components in the light source unit (optical device) of the third embodiment.

[0033] Figure 9 This is an enlarged perspective view of the main part of the mounting portion of the electronic components in the light source unit (optical device) of the fourth embodiment.

[0034] Figure 10 It means in Figure 9 A top view showing the state of the electronic components installed and viewed from above.

[0035] Figure 11 This is an enlarged perspective view of the main part of the mounting portion of the electronic components in the light source unit (optical device) of the fifth embodiment.

[0036] Figure 12 Is Figure 11 An enlarged 3D view of the main part of the device with electronic components installed.

[0037] Figure 13 This is an enlarged cross-sectional view of the main part of the light source unit along the stacking direction in the fifth embodiment.

[0038] Explanation of symbols

[0039] 10 light source units (optical devices)

[0040] 40-layer stacked substrate

[0041] Functional layers 41-47

[0042] 43 Second Functional Layer

[0043] 44 First Functional Layer

[0044] 60. Light-receiving element (electronic component)

[0045] 62a, 62b connection terminals

[0046] 73a, 73b First Wiring

[0047] 74a, 74b Second Wiring

[0048] 77. Conductive materials. Detailed Implementation

[0049] Hereinafter, with reference to the accompanying drawings, an embodiment of the present invention, namely an optical device and an electronic component mounting method, will be described. Furthermore, the embodiments shown below are detailed descriptions provided to better understand the spirit of the invention, and are not intended to limit the invention unless otherwise specified. Additionally, in the accompanying drawings used in the following description, for ease of understanding of the features of the invention, some parts that will be considered key components are sometimes shown as enlarged portions, and the dimensions and proportions of each component may not be identical to the actual dimensions.

[0050] (Optical device: First embodiment)

[0051] In the following embodiments, as an example of an optical device, a light source unit with monitoring function (hereinafter, sometimes referred to as a light source unit) that can be used in AR glasses or small projectors will be described.

[0052] Figure 1 This is a perspective view showing the interior of the optical device according to the first embodiment of the present invention as viewed from above. Additionally, Figure 2 It means to observe from above. Figure 1 A top view of the interior of the optical device. Figure 3 It is along Figure 2 A cross-sectional view of the laminated substrate of the optical device that forms the A-A' line.

[0053] The light source unit (optical device) 10 in this embodiment is a combiner that aligns the three primary colors of light, namely red (R), green (G), and blue (B). This optical device 10 is used, for example, as a combiner mounted on a head-mounted display.

[0054] The light source unit 10 includes a laminated substrate 40, an LD (optical semiconductor element) 30 disposed on the laminated substrate 40, a PLC (optical component) 50 serving as an optical waveguide, and a light-receiving element (electronic component) 60.

[0055] The laminated substrate 40 is a substrate in which multiple functional layers are stacked, and in this embodiment, seven functional layers 41 to 47 are stacked sequentially from the bottom layer. Cavities 48 are formed in functional layers 45 to 47, with the periphery retaining a wall-like structure and the interior being hollow. With this structure, the laminated substrate 40 is formed into a cavity structure that houses the LD30, PLC50, and light-receiving element 60 within the cavity 48. Furthermore, the upper open surface of this cavity 48 is closed by a cover (not shown) made of, for example, a metal plate. This cover is fixed to a metal frame formed on the functional layer 47 by nickel-gold plating via resistance welding.

[0056] An opening 81, covered by a glass dome 82, is formed on one side wall of the partition cavity 48. This opening 81 serves as a window for the tri-color light (projection light) emitted from the main core of the PLC 50 to exit towards the outside of the cavity 48. The interior of the cavity 48 is kept airtight, for example, by being replaced by an inert gas. Furthermore, a collimating lens or the like may also be disposed inside the opening 81.

[0057] The LD (optical semiconductor element) 30 is composed of LD30-1 emitting red light, LD30-2 emitting green light, and LD30-3 emitting blue light. LD30-1, 30-2, and 30-3 are arranged at a predetermined interval from each other in a direction approximately orthogonal to the emission direction of the light emitted from each LD30, for example, they can be disposed on the upper surface of the subcarrier.

[0058] In addition, of course, the LD30 can also use light other than red (R), green (G), and blue (B) shown in this embodiment. The order in which the red (R), green (G), and blue (B) are mounted does not need to be this order and can be appropriately changed.

[0059] In addition, for example, red light can use light with a peak wavelength of 605nm to 750nm, green light can use light with a peak wavelength of 495nm to 570nm, and blue light can use light with a peak wavelength of 405nm to 494nm.

[0060] The multiple functional layers 41 to 47 constituting the laminated substrate 40 can be made of dielectric materials, such as ceramic sheets. Thus, the light source unit 10 is formed as a ceramic package. Furthermore, a semi-cylindrical cutout 11, called a caster, can be formed on the outer peripheral surface of the light source unit 10. With this cutout, when the light source unit 10 is fixed to a mounting substrate, for example, by solder, the climb of the solder towards the cutout 11 can be visually confirmed, improving the reliability of the light source unit 10's mounting.

[0061] In this embodiment, among the plurality of functional layers 41 to 47, the third functional layer from the bottom forms a second functional layer 43 that supports the light-receiving element (electronic component) 60, and the fourth functional layer from the bottom forms a first functional layer 44 that supports the PLC (optical component) 50.

[0062] The PLC (optical component) 50 is formed using a quartz plate with known semiconductor processes, including photolithography or dry etching, used in the formation of microstructures such as integrated circuits. The PLC 50 is provided with main cores (optical waveguides) 51-1, 51-2, and 51-3 corresponding to LD30-1, 30-2, and 30-3, respectively, sub-cores (optical waveguides) 52-1, 52-2, and 52-3 branching off from the paths of the main cores 51-1, 51-2, and 51-3, respectively, and cladding 53 surrounding these main cores 51 and sub-cores 52.

[0063] Therefore, the main cores 51-1, 51-2, and 51-3, after branching out along the direction of light propagation from the sub-cores 52-1, 52-2, and 52-3, merge into one, serving as the combining main core 51-4, which reaches the main output end 55 of the PLC 50. This combining main core 51-4 faces the opening 81, and through a cover glass 82 or similar material, the main output light after the three colors of light are combined is emitted to the outside of the cavity 48.

[0064] On the other hand, sub-cores 52-1, 52-2, and 52-3 merge into one along the direction of light propagation, forming a multiplexer sub-core 52-4 that reaches the sub-emission end 56 of the PLC 50. This multiplexer sub-core 52-4's sub-emission end 56 is positioned opposite to the light-receiving surface 61 of the light-receiving element (electronic component) 60 described below, and light emitted from the sub-emission end 56 is incident on the light-receiving element (electronic component) 60. That is, the light-receiving element (electronic component) 60 is configured to receive the light propagating in the multiplexer sub-core 52-4. Furthermore, the sub-emission end 56 and the light-receiving surface 61 can also be optically connected.

[0065] There are no particular restrictions on the thickness of the cladding 53, or the width dimensions of the main core 51 and the sub-core 52. For example, a main core 51 and a sub-core 52 with width dimensions of a few micrometers can be disposed in a cladding 53 with a thickness of about 50 μm.

[0066] The main core 51, sub-core 52, and cladding 53 are, for example, made of quartz, with the refractive index of the main core 51 and sub-core 52 being a predetermined value higher than that of the cladding 53. Thus, light incident on each of the main core 51 and sub-core 52 undergoes total internal reflection at the interface between each core and the cladding 53, and then propagates within each core. The main core 51 and sub-core 52 can be doped with impurities such as germanium (Ge) in amounts corresponding to the aforementioned predetermined values.

[0067] Regarding the PLC50 with the above structure, the light output from LD30-1, 30-2, and 30-3 is incident on the main cores (optical waveguides) 51-1, 51-2, and 51-3 respectively, and propagates towards the main output end 55. During this propagation, at least a portion of the propagating light is split into sub-cores 52-1, 52-2, and 52-3. Then, the light propagating in the main cores 51-1, 51-2, and 51-3 is combined and emitted as the main output light from the main output end 55 of the combined main core 51-4.

[0068] On the other hand, the light that is split from the main core 51 and propagates in the sub-cores 52-1, 52-2, and 52-3 is also combined and emitted from the sub-emission end 56 of the combined sub-core 52-4.

[0069] The sub-output light emitted from the sub-emission end 56 is used, for example, as a monitoring light to confirm the amount or hue of the main output light, and is incident on the light-receiving element (electronic component) 60 for photoelectric conversion.

[0070] Regarding the light-receiving element (electronic component) 60, for example, it is formed in a cuboid shape and is mounted on one side 43a of the second functional layer 43 of the laminated substrate 40. In the mounted state, the light-receiving element (electronic component) 60 has a light-receiving surface 61 formed on a vertical surface 60a perpendicular to one side 43a of the second functional layer 43. Furthermore, a pair of connecting terminals 62a and 62b are formed on another vertical surface 60b opposite to this vertical surface 60a. These connecting terminals 62a and 62b can be simply flat metal plates extending vertically relative to one side 43a of the second functional layer 43.

[0071] A component mounting hole 71 is formed in the first functional layer 44 of the laminated substrate 40, exposing one side 43a of the second functional layer 43. This component mounting hole 71 is formed at a position overlapping with the mounting position of the light-receiving element 60, and the light-receiving element 60 is mounted through the component mounting hole 71. Thus, the connecting terminals 62a and 62b are formed in a manner that extends parallel to the inner peripheral surface 71a of the component mounting hole 71 when the light-receiving element 60 is mounted.

[0072] Furthermore, when the first functional layer 44 and the second functional layer 43 are separated, or when one or more other functional layers are stacked between the first functional layer 44 and the second functional layer 43, such component mounting holes 71 can also be formed in a manner that penetrates the first functional layer 44 and other functional layers.

[0073] The second functional layer 43 has a second wiring 74a electrically connected to one connection terminal 62a of the light-receiving element 60 and a second wiring 74b electrically connected to another connection terminal 62b of the light-receiving element 60. As for the second wirings 74a and 74b, a portion of them is exposed from the first functional layer 44 in the opening area of ​​the component mounting hole 71.

[0074] On the other hand, the first functional layer 44 also has a first wiring 73a electrically connected to a connection terminal 62a of the light-receiving element 60 and a first wiring 73b electrically connected to another connection terminal 62b of the light-receiving element 60.

[0075] These first wirings 73a, 73b, and second wirings 74a, 74b can be, for example, tungsten or molybdenum wirings, and can be formed with a thickness of about 5 μm to 30 μm. Furthermore, an electroless nickel plating with a thickness of about 1 μm to 10 μm can be formed on these tungsten or molybdenum wirings; moreover, an electroless gold plating with a thickness of about 1 μm to 4 μm can also be formed.

[0076] Therefore, interlayer connection wiring (through-hole wiring) 75a electrically connecting the first wiring 73a and the second wiring 74a, and interlayer connection wiring (through-hole wiring) 75b electrically connecting the first wiring 73b and the second wiring 74b are respectively formed in the first functional layer 44. Such interlayer connection wiring (through-hole wiring) 75a, 75b can be formed, for example, by forming vias (through holes) in the first functional layer 44 and filling the interior of the vias with conductive material.

[0077] Therefore, the first wiring 73a and the second wiring 74a are wirings with the same function that have been branched into two wirings. Similarly, the first wiring 73b and the second wiring 74b are wirings with the same function that have been branched into two wirings.

[0078] like Figure 4 As shown in the enlarged view of the main part, the first wirings 73a and 73b formed on one side 44a of the first functional layer 44 are formed such that the wiring ends 73a1 and 73b1 on one side, which are respectively connected to the connection terminals 62a and 62b of the light-receiving element 60 by the conductive material 77 described below, are located at the position facing the inner peripheral surface 71a of the component mounting hole 71.

[0079] like Figure 5 As shown in the enlarged view of the main part, the connection terminal 62a of the light-receiving element (electronic component) 60 is electrically connected to the first wiring 73a formed on the first functional layer 44 and the second wiring 74a formed on the second functional layer 43 via the conductive material 77.

[0080] Similarly, the connection terminal 62b of the light-receiving element (electronic component) 60 is electrically connected to the first wiring 73b formed on the first functional layer 44 and the second wiring 74b formed on the second functional layer 43 via the conductive material 77.

[0081] The conductive material 77 is formed in such a way that it fills the gap between the connection terminals 62a and 62b of the light-receiving element (electronic component) 60 extending along the stacking direction and the inner peripheral surface 71a of the component mounting hole 71. It is connected at the bottom to the second wirings 74a and 74b extending along one side 43a of the second functional layer 43, and at the top to the wiring ends 73a1 and 73b1 of the first wirings 73a and 73b extending along one side 44a of the first functional layer 44, respectively, in a manner that covers them.

[0082] This conductive material 77 can be, for example, a conductive resin such as silver paste mixed with silver particles and a curing resin, or copper paste mixed with copper particles and a curing resin.

[0083] According to the above-described embodiment of the light source unit (optical device) 10, even if the connection terminals 62a and 62b of the light receiving element (electronic component) 60 are installed in a manner that extends perpendicularly to the extension direction of the second wiring 74a and 74b extending along the mounting surface, i.e., one side 43a of the second functional layer 43, poor connection of the connection terminals 62a and 62b of the light receiving element (electronic component) 60 can be prevented.

[0084] That is, by connecting a connection terminal 62a to both the first wiring 73a and the second wiring 74a, which have the same function, via a conductive material 77, the continuity of the connection terminal 62a can be made reliable. Similarly, by connecting a connection terminal 62b to both the first wiring 73b and the second wiring 74b, which have the same function, via a conductive material 77, the continuity of the connection terminal 62b can be made reliable.

[0085] Furthermore, the conductive material 77 extends in the narrow gap between the connecting terminals 62a, 62b and the inner peripheral surface 71a of the component mounting hole 71, resulting in minimal variation in width in the vertical direction. It is formed on the upper side in such a way that it covers the wiring ends 73a1, 73b1 of the first wirings 73a, 73b respectively. Therefore, a large contact area can be ensured relative to the first wirings 73a, 73b and the second wirings 74a, 74b, and reliable conduction can be achieved.

[0086] In addition, in this embodiment, the first functional layer 44 and the second functional layer 43 are formed as adjacent layers, but it can also be structured as follows: at the position where the first functional layer 44 and the second functional layer 43 are separated, for example, between the first functional layer 44 and the second functional layer 43, one or more other functional layers are stacked.

[0087] In addition, in this embodiment, the second functional layer 43 constitutes the third layer from the bottom of the laminated substrate 40, and the first functional layer 44 constitutes the fourth layer. However, there is no limitation on the position of the first or second functional layer in the laminated substrate, as long as the second functional layer is arranged in a structure that is at least lower than the first functional layer.

[0088] (Optical device: Second embodiment)

[0089] The light source unit (optical device) according to the second embodiment of the present invention will be described. Furthermore, structures identical to those in the first embodiment will be labeled with the same reference numerals, and repeated descriptions will be omitted.

[0090] Figure 6 It means equivalent to along Figure 2 A cross-sectional view of the light source unit (optical device) in the second embodiment, showing the position of line A-A'. Additionally, Figure 7 It is an enlarged 3D view showing the main parts of the mounting section of the electronic components.

[0091] Regarding the light-receiving element (electronic component) 160 of the light source unit (optical device) 110 of this embodiment, which is mounted on the second functional layer 43 of the laminated substrate 40, a light-receiving surface 161 and a pair of connection terminals 162a and 162b are simultaneously formed on a vertical surface 160a perpendicular to one side 43a of the second functional layer 43. That is, connection terminals 162a and 162b are formed on both sides of the light-receiving surface 161.

[0092] Additionally, a second wiring 74a electrically connected to one connection terminal 162a of the light-receiving element 160 and a second wiring 74b electrically connected to another connection terminal 162b of the light-receiving element 160 are respectively formed in the second functional layer 43. As for the second wirings 74a and 74b, a portion of them is exposed from the first functional layer 44 in the opening area of ​​the component mounting hole 71.

[0093] On the other hand, a first wiring 73a electrically connected to a connection terminal 162a of the light-receiving element 160 and a first wiring 73b electrically connected to another connection terminal 162b of the light-receiving element 160 are also formed in the first functional layer 44. These first wirings 73a and 73b are formed in such a way that they extend toward the component mounting hole 71 facing the side opposite to a vertical surface 160a of the light-receiving element (electronic component) 160.

[0094] Therefore, in this embodiment, a connection terminal 162a of the light-receiving element (electronic component) 160 is also electrically connected to the first wiring 73a formed on the first functional layer 44 and the second wiring 74a formed on the second functional layer 43 via the conductive material 77.

[0095] Similarly, another connection terminal 162b of the light-receiving element (electronic component) 160 is electrically connected to the first wiring 73b formed on the first functional layer 44 and the second wiring 74b formed on the second functional layer 43 via a conductive material 77.

[0096] The conductive material 77 is formed in such a way that it fills the gap between the connection terminals 162a and 162b of the light-receiving element (electronic component) 160 extending along the stacking direction and the inner peripheral surface 71a of the component mounting hole 71. It is connected at the bottom to the second wirings 74a and 74b extending along one side 43a of the second functional layer 43, and at the top to the wiring ends 73a1 and 73b1 of the first wirings 73a and 73b extending along one side 44a of the first functional layer 44, respectively, in a manner that covers them.

[0097] Thus, even when the light-receiving surface 161 of the light-receiving element (electronic component) 160 and the pair of connecting terminals 162a and 162b are both formed on the same surface (a vertical surface 160a), the connection terminal 62a can be reliably connected by connecting one connecting terminal 162a to both the first wiring 73a and the second wiring 74a, which have the same function, via the conductive material 77. Similarly, the connection terminal 62b can be reliably connected by connecting one connecting terminal 162b to both the first wiring 73b and the second wiring 74b, which have the same function, via the conductive material 77.

[0098] (Optical device: Third embodiment)

[0099] The light source unit (optical device) of the third embodiment of the present invention will be described. Furthermore, structures identical to those in the first embodiment will be labeled with the same reference numerals, and repeated descriptions will be omitted.

[0100] Figure 8 This is an enlarged perspective view of the main part of the mounting portion of the electronic components in the light source unit (optical device) of this embodiment.

[0101] In the light source unit (optical device) 210 of this embodiment, the wiring ends 73a1 and 73b1 facing the component mounting holes 71 formed on the first functional layer 44 are formed at a position that is set back from the inner peripheral surface 71a of the component mounting holes 71. The distance Δt between the inner peripheral surface 71a of the component mounting holes 71 and each end face of the wiring ends 73a1 and 73b1 can be, for example, in the range of 0.1 mm to 0.5 mm.

[0102] With this structure of the present embodiment, when the connection terminal of the transverse light-receiving element is electrically connected to both the first wiring 73a, 73b and the second wiring through conductive material, in particular, by forming a gap between the inner peripheral surface 71a of the component mounting hole 71 and the wiring ends 73a1, 73b1 of the first wiring 73a, 73b respectively, the contact portion of the conductive material is increased, and the conductive material can be more firmly fixed to the connection portion.

[0103] (Optical device: Fourth embodiment)

[0104] The light source unit (optical device) according to the fourth embodiment of the present invention will be described. Furthermore, structures identical to those in the first embodiment will be labeled with the same reference numerals, and repeated descriptions will be omitted.

[0105] Figure 9 This is an enlarged perspective view showing the main part of the mounting portion of the electronic components in the light source unit (optical device) of this embodiment. Additionally, Figure 10 It means in Figure 9 A top view showing the state of the electronic components installed and viewed from above.

[0106] In the light source unit (optical device) 310 of this embodiment, electrode recesses 311a and 311b are respectively formed at the wiring ends 73a1 and 73b1 facing the component mounting holes 71 formed on the first wirings 73a and 73b of the first functional layer 44. These recesses are connected to the inner peripheral surface 71a of the component mounting holes 71 and extend along the stacking direction.

[0107] These electrode recesses 311a and 311b are, for example, semi-cylindrical cutouts formed by crossing the first functional layer 44 from the respective wiring ends 73a1 and 73b1 of the first wirings 73a and 73b.

[0108] According to this embodiment, when the connection terminals 362a and 362b of the light-receiving element (electronic component) 360 are electrically connected to the first wiring 73a, 73b and the second wiring through the conductive material 77, by increasing the contact area relative to the conductive material 77, the conduction between the connection terminals 362a and 362b of the light-receiving element (electronic component) 360 and the first wiring 73a, 73b and the second wiring can be made reliable and poor connection can be prevented.

[0109] In addition, when the conductive material 77 is formed, it also flows into the electrode recesses 311a and 311b, which makes the conduction between the first wiring 73a and 73b and the second wiring more reliable.

[0110] (Optical device: Fifth embodiment)

[0111] The light source unit (optical device) according to the fifth embodiment of the present invention will be described. Furthermore, structures identical to those in the first embodiment will be labeled with the same reference numerals, and repeated descriptions will be omitted.

[0112] Figure 11 This is an enlarged perspective view showing the main part of the mounting portion of the electronic components in the light source unit (optical device) of this embodiment. Additionally, Figure 12 Is Figure 11 An enlarged 3D view of the main parts with electronic components installed. Additionally, Figure 13 This is an enlarged cross-sectional view of the main part of the light source unit along the stacking direction in this embodiment.

[0113] In the light source unit (optical device) 410 of this embodiment, the first wirings 73aA and 73bA formed on the first functional layer 44 are formed with one side 71a1 facing the inner peripheral surface 71a of the component mounting hole 71, and the first wirings 73aB and 73bB are formed with the other side 71a2 facing the inner peripheral surface 71a of the component mounting hole 71.

[0114] Therefore, interlayer connection wiring (through-hole wiring) 75a1 and 75b1 are formed in the first functional layer 44 to electrically connect each of the second wirings 74a and 74b formed in the lower layer of the first functional layer 44, namely the second functional layer 43, to each of the first wirings 73aA and 73bA. Similarly, interlayer connection wiring (through-hole wiring) 75a2 and 75b2 are formed in the first functional layer 44 to electrically connect each of the second wirings 74a and 74b to each of the other first wirings 73aB and 73bB.

[0115] With this structure, the first wiring 73aA and the first wiring 73aB are electrically connected via the second wiring 74a, functioning as a series of wirings with the same function. Additionally, the first wiring 73bA and the first wiring 73bB are electrically connected via the second wiring 74b, functioning as a series of wirings with the same function.

[0116] On the other hand, in this embodiment, the light-receiving element (electronic component) 460 has a light-receiving surface 461 formed on a vertical surface 460a perpendicular to one side 43a of the second functional layer 43, and connection terminals 462a1 and 462b1 are formed on both sides thereon. On the other hand, connection terminals 462a2 and 462b2 are formed on another vertical surface 460b of the light-receiving element (electronic component) 460. Connection terminals 462a1 and 462a2 are electrically identical terminals that are interconnected, and connection terminals 462b1 and 462b2 are electrically identical terminals that are interconnected.

[0117] Additionally, bumps 465a and 465b are formed in the areas of the second wirings 74a and 74b exposed from the component mounting holes 71 in the second functional layer 43. These bumps 465a and 465b can be formed by stacking conductive metals, such as gold, silver, solder alloys, or tungsten layers constituting the first wirings 73aA and 73bA, and the second wirings 74a and 74b.

[0118] The conductive material 77 is formed to connect the connection terminal 462a1, the first wiring 73aA, and the second wiring 74a; and also to connect the connection terminal 462a2, the first wiring 73aB, and the second wiring 74a. Similarly, the conductive material 77 is formed to connect the connection terminal 462b1, the first wiring 73bA, and the second wiring 74b; and also to connect the connection terminal 462b2, the first wiring 73bB, and the second wiring 74b.

[0119] That is, the light-receiving element (electronic component) 460 connects the electrically identical 462a1 and the connecting terminal 462a2 to the first wiring 73aA and the second wiring 74a and the first wiring 73aB and the second wiring 74a respectively via conductive material 77. Additionally, the electrically identical 462b1 and the connecting terminal 462b2 are connected to the first wiring 73bA and the second wiring 74b and the first wiring 73bB and the second wiring 74b respectively via conductive material 77.

[0120] In addition, each conductive material 77 is also connected to the conductive bumps 465a and 465b formed on the second wirings 74a and 74b.

[0121] Thus, in this embodiment, by forming multiple electrically identical connection terminals in the light-receiving element (electronic component) 460, and then forming each connection terminal across the first wiring and the second wiring, it is possible to more reliably prevent poor connection of the light-receiving element (electronic component) 460 compared to the embodiments described above.

[0122] Furthermore, in the light source unit (optical device) 410 of this embodiment, a component mounting recess 481 is formed in the portion of the second functional layer 43 that is exposed from the component mounting hole 71 and held by the second wiring 74a and the second wiring 73b, and is recessed in the thickness direction of the second functional layer 43. Then, the interior of the component mounting recess 481 is filled to form a component fixing resin layer 482 that is in contact with the bottom of the light-receiving element (electronic component) 460.

[0123] With this structure, when installing the light-receiving element 460, the light-receiving element 460 can be fixed to the second functional layer 43 by the component fixing resin layer 482, and then each connection terminal of the light-receiving element 460 can be electrically connected to the first wiring and the second wiring by each conductive material 77. Therefore, the workability of installing the light-receiving element 460 can be improved, and the installation operation can be made easier.

[0124] (Installation method for electronic components)

[0125] Next, the formation of the first implementation method ( Figures 1-5 The installation method of the electronic components of the light source unit (optical device) 10 is explained.

[0126] When mounting electronic components, such as light-receiving elements 60, onto the laminated substrate 40 before mounting the electronic components, firstly, the light-receiving elements 60 are positioned at a predetermined position on one side 43a of the second functional layer 43 exposed from the component mounting hole 71 formed in the first functional layer 44 (mounting process).

[0127] At this time, it is also preferable to use a resin such as an adhesive to fix the bottom surface of the light-receiving element 60 and the side 43a of the second functional layer 43 exposed between the second wirings 74a and 74b. As an adhesive, an adhesive called a chip bonding material, such as an epoxy-based adhesive, can also be used. Specifically, after dispensing the chip bonding material (adhesive), after placing and temporarily fixing the light-receiving element 60, the conductive resin described below is filled and heat-cured.

[0128] Next, a conductive resin, such as silver paste, is filled in such a way that it fills the gap between the connection terminal 62a of the light-receiving element 60 and the inner peripheral surface 71a of the component mounting hole 71, forming a conductive material 77 that electrically connects the connection terminal 62a to the first wiring 73a and the second wiring 74a (connection process).

[0129] Similarly, conductive resin is filled in such a way that it fills the gap between the connection terminal 62b of the light-receiving element 60 and the inner peripheral surface 71a of the component mounting hole 71, forming a conductive material 77 (connection process) that electrically connects the connection terminal 62b to the first wiring 73b and the second wiring 74b.

[0130] Thus, by electrically connecting a connection terminal 62a to both the first wiring 73a and the second wiring 74a, which have the same function, via a conductive material 77 filled with conductive resin and cured, the continuity of the connection terminal 62a can be reliably ensured. Similarly, by electrically connecting a connection terminal 62b to both the first wiring 73b and the second wiring 74b, which have the same function, via a conductive material 77 filled with conductive resin and cured, the continuity of the connection terminal 62b can be reliably ensured.

[0131] The foregoing has described one embodiment of the present invention, but this embodiment is merely illustrative and is not intended to limit the scope of the invention. This embodiment can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. This embodiment or its variations are included within the scope or spirit of the invention, and also within the scope of the invention as described in the claims and its equivalents.

Claims

1. An optical device, wherein, It is an optical device having a multilayer substrate with multiple functional layers, and optical and electronic components disposed on the multilayer substrate. The functional layer has at least a first functional layer for housing the optical components and a second functional layer disposed closer to the lower layer than the first functional layer and for housing the electronic components. A first wiring is provided on one side of the first functional layer, and a second wiring is provided on one side of the second functional layer. A component mounting hole is formed in the first functional layer, which penetrates the first functional layer, and the electronic component is mounted in the component mounting hole. The connection terminals of the electronic component are electrically connected to both the first wiring and the second wiring via a conductive material. An electrode recess is formed at the end of the first wiring of the first functional layer, which is connected to the inner peripheral surface of the component mounting hole and extends along the stacking direction, and is cut out in the direction that expands the component mounting hole. The electrode recess crosses the first functional layer from the end of the first wiring and is connected to the second wiring via the conductive material, and the conductive material flows into the electrode recess.

2. The optical device according to claim 1, wherein, The first wiring and the second wiring are electrically connected via interlayer connection wiring disposed on the laminated substrate.

3. The optical device according to claim 1, wherein, The conductive material is located between the inner circumferential surface of the component mounting hole and the connecting terminal.

4. The optical device according to claim 1 or 3, wherein, The end of the first wiring is located behind the inner circumferential surface of the component mounting hole.

5. The optical device according to claim 1, wherein, In the second functional layer, a component mounting recess is formed in the area exposed from the component mounting hole, which is recessed in the thickness direction, and a component fixing resin layer is formed to fill the interior of the component mounting recess and to be in contact with at least the bottom of the electronic component.

6. The optical device according to claim 1, wherein, The conductive material is a conductive resin.

7. The optical device according to claim 1, wherein, The electronic component is a light-receiving element, and the optical component includes an optical waveguide. The light-receiving element is optically connected to receive at least a portion of the light propagating in the optical waveguide.

8. A method for installing an electronic component, wherein, This is a mounting method for electronic components mounted on a laminated substrate. The laminated substrate has at least a first functional layer with a first wiring on one side, a second functional layer disposed closer to the lower layer than the first functional layer and with a second wiring on one side, and a component mounting hole penetrating the first functional layer and exposing one side of the second functional layer. An electrode recess is formed at the end of the first wiring of the first functional layer, which is connected to the inner peripheral surface of the component mounting hole and extends along the lamination direction, and is cut out in the direction that expands the component mounting hole. The installation method has at least the following characteristics: The process of inserting the electronic component into the component mounting hole and positioning the electronic component on one side of the second functional layer; and A connection process in which conductive material is disposed between a connection terminal of the electronic component and the first wiring and the second wiring, and an electrical connection is made. The electrode recess extends from the end of the first wiring across the first functional layer and is connected to the second wiring via the conductive material, which flows into the electrode recess.

9. The method for installing electronic components according to claim 8, wherein, The connection process involves using conductive resin as the conductive material, filling the space between the connection terminal and the inner circumferential surface of the component mounting hole with the conductive resin, and electrically connecting one connection terminal of the electronic component to the first wiring and the second wiring.

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