Photoelectric mixed galvanizing system

Abstract

To provide an optical-electric mixed-signal device having an optical connection structure with high connectivity reliability. [Solution] The optical-electric mixed-signal device comprises a wiring substrate having a glass layer and a wiring layer including pads provided on the glass layer; an optical integrated circuit disposed on the glass layer and electrically connected to the pads; an optical fiber disposed on the glass layer and capable of transmitting and receiving optical signals with the optical integrated circuit; and a glass fixing member disposed on the glass layer and sandwiching the optical fiber between itself and the glass layer.

Description

Technical Field

[0001] The present invention relates to an optoelectronic hybrid device.

Background Art

[0002] In a data center or the like where various devices such as computers and data communication devices are installed, an optical connection structure for connecting an optical waveguide device and an optical fiber or the like may be used. As an example of such an optical connection structure, an optical connection component using a planar lightwave circuit is adhesively fixed to the end face of the input / output waveguide of the optical waveguide device, and the optical waveguide device and the optical fiber are optically connected via the planar lightwave circuit (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above optical connection structure, since the optical waveguide device and the optical connection component are adhesively fixed with a small adhesive area, the adhesive strength between the two is weak. Therefore, when stress is applied to the connection portion between the optical waveguide device and the optical connection component, there is a risk that the connection between the optical waveguide device and the optical connection component will break, and the connection reliability cannot be said to be high.

[0005] The present invention has been made in view of the above points, and an object thereof is to provide an optoelectronic hybrid device having an optical connection structure with high connection reliability.

Means for Solving the Problems

[0006] The optical-electric mixed-signal device comprises a wiring substrate having a glass layer and a wiring layer including pads provided on the glass layer; an optical integrated circuit disposed on the glass layer and electrically connected to the pads; an optical fiber disposed on the glass layer and capable of transmitting and receiving optical signals with the optical integrated circuit; and a glass fixing member disposed on the glass layer and sandwiching the optical fiber between itself and the glass layer. [Effects of the Invention]

[0007] According to the disclosed technology, it is possible to provide an optoelectronic hybrid device having an optical connection structure with high connectivity reliability. [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view illustrating a photoelectric mixed-signal device according to the first embodiment. [Figure 2] This is a cross-sectional view (part 1) illustrating a photoelectric mixed-signal device according to the first embodiment. [Figure 3] This is a cross-sectional view (part 2) illustrating a photoelectric mixed-signal device according to the first embodiment. [Figure 4] This is a plan view illustrating a photoelectric mixed-signal device according to a modified example 1 of the first embodiment. [Figure 5] This is a cross-sectional view illustrating a photoelectric mixed-signal device according to Modification 1 of the First Embodiment. [Modes for carrying out the invention]

[0009] The embodiments for carrying out the invention will be described below with reference to the drawings. In each drawing, the same reference numerals are used for identical components, and redundant explanations may be omitted.

[0010] <First Embodiment> [Structure of a photoelectric mixed-signal device] Figure 1 is a plan view illustrating an optical-electric combined galvanizing apparatus according to the first embodiment. Figure 2 is a cross-sectional view illustrating an optical-electric combined galvanizing apparatus according to the first embodiment, showing a cross-section along line AA in Figure 1. Figure 3 is a cross-sectional view illustrating an optical-electric combined galvanizing apparatus according to the first embodiment, showing a cross-section along line BB in Figure 1.

[0011] Referring to Figures 1 to 3, the photoelectric mixed-signal device 1 includes a wiring board 10, an optical integrated circuit 20, an optical fiber 40, and a fixing member 50. The photoelectric mixed-signal device 1 may further include a bonding material 30 and a resin part 60.

[0012] The wiring board 10 comprises a glass layer 11 and a wiring layer 12. The wiring board 10 may also include electronic components electrically connected to the wiring layer 12. The electronic components include passive and active components. An example of an active component is a semiconductor device that has the function of amplifying an electrical signal input from the optical integrated circuit 20.

[0013] The glass layer 11 is an insulating layer. The type of glass that makes up the glass layer 11 is not limited, but for example, alkali-free glass, quartz glass, borosilicate glass, etc. can be used. The thickness of the glass layer 11 is, for example, about 100 to 1000 μm.

[0014] The wiring layer 12 is provided on the upper surface 11a of the glass layer 11. The wiring layer 12 may be provided such that its lower and side surfaces are embedded in the glass layer 11, and its upper surface is exposed from the upper surface 11a of the glass layer 11. The wiring layer 12 includes pads and wiring patterns. As the material for the wiring layer 12, for example, copper (Cu) can be used. The thickness of the wiring layer 12 is, for example, about 10 to 40 μm.

[0015] If necessary, a metal layer may be formed on the upper surface of the pads constituting the wiring layer 12, or an antioxidant treatment such as OSP (Organic Solderability Preservative) treatment may be performed. Examples of the metal layer include an Au layer, a Ni / Au layer (a metal layer in which a Ni layer and an Au layer are laminated in this order), a Ni / Pd / Au layer (a metal layer in which a Ni layer, a Pd layer, and an Au layer are laminated in this order), and the like.

[0016] The glass layer 11 may be provided with through-holes penetrating the glass layer 11 in the thickness direction. Further, a wiring layer may be provided on the lower surface of the glass layer 11. The wiring layer provided on the lower surface of the glass layer 11 may be connected to the wiring layer 12 through through-holes penetrating the glass layer 11.

[0017] The photonic integrated circuit 20 (PIC: Photonic Integrated Circuit) has a main body 21 and electrodes 22. The main body 21 is, for example, a substrate such as silicon on which a plurality of optical waveguides, light-emitting elements, light-receiving elements, etc. are provided. The electrodes 22 are, for example, connection terminals composed of gold bumps, solder bumps, copper posts with solder at the tips, etc. The electrodes 22 are disposed on one surface side of the main body 21. The optical waveguides are disposed on the same surface side as the electrodes 22 of the main body 21.

[0018] The photonic integrated circuit 20 may be referred to as silicon photonics or the like. The photonic integrated circuit 20 can have a function of converting an optical signal input from the optical fiber 40 into an electrical signal, and / or a function of converting an input electrical signal into an optical signal and outputting it to the optical fiber 40.

[0019] The photonic integrated circuit 20 is disposed on the glass layer 11 and is electrically connected to the pads constituting the wiring layer 12. Specifically, the photonic integrated circuit 20 is flip-chip mounted in a face-down state on the upper surface 11a of the glass layer 11. That is, the electrodes 22 of the photonic integrated circuit 20 are joined to the pads constituting the wiring layer 12 through a conductive bonding material 30 such as solder.

[0020] The optical fiber 40 is disposed on the glass layer 11 adjacent to the optical integrated circuit 20. The number of optical fibers 40 may be any number of one or more, but in the illustrated example, four optical fibers 40 are juxtaposed at a predetermined interval. The optical fiber 40 extends outside the glass layer 11 across one side of the upper surface 11a of the glass layer 11 in a plan view.

[0021] The gap between each optical fiber 40 and the optical integrated circuit 20 is, for example, about several tens of μm. The end of each optical waveguide of the optical integrated circuit 20 faces the end of each optical fiber 40. Therefore, each optical waveguide of the optical integrated circuit 20 can transmit and receive optical signals to and from each optical fiber 40. A bonding material may be disposed in the gap between each optical fiber 40 and the optical integrated circuit 20. As the bonding material, for example, an optical adhesive having good transmittance with respect to the wavelength of the optical signal transmitted and received between the optical fiber 40 and the optical integrated circuit 20 can be used.

[0022] The fixing member 50 is disposed on the glass layer 11 and sandwiches the optical fiber 40 between it and the glass layer 11. The fixing member 50 is, for example, made of glass. The fixing member 50 has, for example, an elongated groove 50x on a surface facing the upper surface 11a of the glass layer 11. The cross section of the groove 50x cut perpendicular to the longitudinal direction is, for example, V-shaped. The cross section of the groove 50x cut perpendicular to the longitudinal direction may be other than V-shaped, such as U-shaped.

[0023] The optical fiber 40 is in contact with the upper surface 11a of the glass layer 11 and the inner wall of the groove 50x. Thereby, the optical fiber 40 is held between the glass layer 11 and the fixing member 50. The fixing member 50 is preferably made of the same glass material as the glass layer 11. Thereby, since the thermal expansion coefficients of the members positioned in the vertical direction of the optical fiber 40 are equal, it is possible to suppress the displacement of the position of the optical fiber 40 depending on the change in the temperature environment. As a result, it becomes possible to stably transmit and receive optical signals between the optical fiber 40 and the optical integrated circuit 20.

[0024] The resin portion 60 is located on the upper surface 11a of the glass layer 11. The resin portion 60 is located at least around the bonding material 30 between the optical integrated circuit 20 and the upper surface 11a of the glass layer 11, and around the optical fiber 40 between the inner wall of the groove 50x and the upper surface 11a of the glass layer 11. This improves the connection reliability between the optical integrated circuit 20 and the glass layer 11, and allows the fixing member 50 to be bonded to the glass layer 11. As the material for the resin portion 60, it is preferable to use a material with good fluidity because it needs to be poured into a narrow space. As the material for the resin portion 60, for example, an insulating resin such as epoxy resin can be used.

[0025] Thus, in the optical-electric mixed-signal device 1, the connection portion between the optical integrated circuit 20 and the optical fiber 40 is located on the glass layer 11. Furthermore, the optical fiber 40 is sandwiched between the glass layer 11 and the fixing member 50. This differs from conventional structures where the connection portion of the two members is located on the outside of the substrate in a plan view, making it less likely for stress to concentrate at the connection portion between the optical integrated circuit 20 and the optical fiber 40. Therefore, the risk of breakage at the connection portion between the optical integrated circuit 20 and the optical fiber 40 can be reduced. In other words, a highly reliable optical connection structure can be realized between the optical integrated circuit 20 and the optical fiber 40.

[0026] Furthermore, since the photoelectric mixed-signal device 1 has a resin part 60, the strength of the connection between the optical integrated circuit 20 and the optical fiber 40 can be increased.

[0027] <Variation 1 of the First Embodiment> Modification 1 of the first embodiment shows an example of a photoelectric mixed-signal device having a resin substrate. Figure 4 is a plan view illustrating the photoelectric mixed-signal device according to Modification 1 of the first embodiment. Figure 5 is a cross-sectional view illustrating the photoelectric mixed-signal device according to Modification 1 of the first embodiment, showing a cross-section along line CC in Figure 4. Referring to Figures 4 and 5, the photoelectric mixed-signal device 1A differs from the photoelectric mixed-signal device 1 in that it has a resin substrate 80.

[0028] The resin substrate 80 is formed from an insulating resin material such as epoxy resin. The resin substrate 80 may have reinforcing members such as glass cloth. The resin substrate 80 may be a build-up substrate in which an insulating layer and a wiring layer are laminated. The resin substrate 80 has an upper surface 80a, a stepped surface 80b that is recessed below the upper surface 80a, and an inner surface 80c that connects the upper surface 80a and the stepped surface 80b. The upper surface 80a and the stepped surface 80b can be, for example, parallel. The stepped surface 80b and the inner surface 80c can be, for example, perpendicular.

[0029] The glass layer 11 is positioned on the stepped surface 80b with the wiring layer 12 facing away from the stepped surface 80b. By positioning the glass layer 11 on the stepped surface 80b, which is recessed below the upper surface 80a, the height of the photoelectric mixed-signal device 1A can be reduced. The resin substrate 80 may include electronic components. The electronic components include passive and active components. For example, a semiconductor device can be mounted on the resin substrate 80, and the semiconductor device and the optical integrated circuit 20 can be electrically connected via the wiring layer provided on the resin substrate 80 and the through-holes provided in the glass layer 11.

[0030] In a plan view, the optical fiber 40 extends to the outside of the resin substrate 80, straddling one side of the resin substrate 80. The upper surface 80a of the resin substrate 80 and the upper surface 11a of the glass layer 11 can be, for example, flush. This allows for the continuous formation of a wiring layer on the upper surface 80a of the resin substrate 80 and the upper surface 11a of the glass layer 11.

[0031] In a plan view, it is preferable that the entire upper surface 11a of the glass layer 11 overlaps with the resin substrate 80. In other words, it is preferable that the side surface of the glass layer 11 does not protrude from the side surface of the resin substrate 80. This suppresses the occurrence of cracks or chips at the edges of the glass layer 11. The side surface of the glass layer 11 may be flush with the side surface of the resin substrate 80, or it may be recessed inward from the side surface of the resin substrate 80.

[0032] The stepped surface 80b can be formed, for example, by counterboring a resin substrate 80 that does not have a stepped surface 80b formed on it. The stepped surface 80b may also be formed by laminating multiple resin layers. For example, it can be formed by laminating a second resin layer on the upper surface of a lower first resin layer, exposing a part of the upper surface of the first resin layer. In this case, the upper surface of the first resin layer exposed from the second resin layer becomes the stepped surface 80b.

[0033] In the example of the photoelectric mixed-signal device 1A, the glass layer 11 is rectangular in plan view, and the resin substrate 80 is provided such that three sides of the glass layer 11 are in contact with the inner surface 80c in plan view. However, it is not limited to this, and for example, the resin substrate 80 may be provided such that all four sides of the glass layer 11 are in contact with the inner surface 80c. In this case, in plan view, the glass layer 11 is framed and surrounded by the resin substrate 80, so that all sides of the glass layer 11 can be protected by the resin substrate 80.

[0034] Although preferred embodiments and their variations have been described in detail above, the invention is not limited to the embodiments and their variations described above, and various modifications and substitutions can be made to the embodiments and their variations described above without departing from the scope of the claims. [Explanation of Symbols]

[0035] 1.1A Photoelectric Mixed-Platform 10 Wiring board 11 glass layer 11a Top side 12 wiring layer 20 Optical Integrated Circuits 21 Main unit 22 electrodes 30 Bonding material 40 Optical Fibers 50 Fixing member 50x grooves 60 Resin part 80 Resin substrate 80a top 80b Step surface 80c inner surface

Claims

1. A wiring substrate comprising a glass layer and a wiring layer including pads provided on the glass layer, An optical integrated circuit disposed on the glass layer and electrically connected to the pad, An optical fiber disposed on the glass layer and capable of transmitting and receiving optical signals with the optical integrated circuit, A photoelectric mixed-signal device having a glass fixing member disposed on the glass layer and sandwiching the optical fiber between itself and the glass layer.

2. The fixing member has a groove on the surface facing the upper surface of the glass layer, The optical fiber is in contact with the upper surface of the glass layer and the inner wall of the groove, as described in claim 1.

3. Having a resin portion located on the upper surface of the glass layer, The optical integrated circuit is bonded to the pad via a conductive bonding material. The photoelectric mixed-signal apparatus according to claim 2, wherein the resin portion is located at least around the bonding material between the optical integrated circuit and the upper surface of the glass layer, and around the optical fiber between the inner wall of the groove and the upper surface of the glass layer.

4. The optical fiber extends to the outside of the glass layer, crossing one side of the upper surface of the glass layer in a plan view, as described in claim 1.

5. The photoelectric mixed-loading apparatus according to claim 1, wherein the fixing member is made of the same glass material as the glass layer.

6. It has a resin substrate having an upper surface and a stepped surface that is recessed below the upper surface, The glass layer is arranged on the stepped surface with the wiring layer facing away from the stepped surface, In a plan view, the optical fiber extends across one side of the resin substrate and outward from the resin substrate, as described in any one of claims 1 to 5.

7. The photoelectric mixed-loading apparatus according to claim 6, wherein the upper surface of the resin substrate and the upper surface of the glass layer are flush.

8. The photoelectric mixed-signal apparatus according to claim 6, wherein, in a plan view, the entire upper surface of the glass layer overlaps with the resin substrate.

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