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 board having a first insulating layer mainly composed of resin and a wiring layer including a pad provided on the first insulating layer; an optical integrated circuit disposed on the first insulating layer and electrically connected to the pad; an optical fiber disposed on the first insulating layer and capable of transmitting and receiving optical signals with the optical integrated circuit; and a glass fixing member disposed on the first insulating layer and sandwiching the optical fiber between itself and the first insulating 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 optical waveguide 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 optical waveguide 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-described 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 of breakage between the optical waveguide device and the optical connection component, 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 first insulating layer mainly composed of resin and a wiring layer including pads provided on the first insulating layer; an optical integrated circuit disposed on the first insulating layer and electrically connected to the pads; an optical fiber disposed on the first insulating layer and capable of transmitting and receiving optical signals with the optical integrated circuit; and a glass fixing member disposed on the first insulating layer and sandwiching the optical fiber between itself and the first insulating 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 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 first insulating layer 11, a wiring layer 12, and a second insulating layer 13. 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 first insulating layer 11 mainly consists of an insulating resin such as an epoxy resin or a polyimide resin. The first insulating layer 11 may have reinforcing members such as glass cloth. The first insulating layer 11 may contain fillers such as silica (SiO2). The thickness of the first insulating layer 11 can be, for example, about 15 to 35 μm. The first insulating layer 11 is, for example, an insulating layer that constitutes a build-up substrate. In this case, any layer such as a wiring layer, insulating layer, or core layer can be placed below the first insulating layer 11. Furthermore, the wiring layer 12 can be electrically connected to the wiring layer below via via wiring provided in the first insulating layer 11.

[0014] The wiring layer 12 is provided on the upper surface 11a of the first insulating layer 11. The wiring layer 12 may be provided such that its lower surface and sides are embedded in the first insulating layer 11, and its upper surface is exposed from the upper surface 11a of the first insulating 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 anti-oxidation treatment such as OSP (Organic Solderability Preservative) treatment may be applied. Examples of metal layers include an Au layer, a Ni / Au layer (a metal layer in which Ni and Au layers are stacked in that order), and a Ni / Pd / Au layer (a metal layer in which Ni, Pd, and Au layers are stacked in that order).

[0016] The second insulating layer 13 is placed on the first insulating layer 11. The second insulating layer 13 is a so-called solder resist layer. The second insulating layer 13 has openings 13x that expose a part of the upper surface 11a of the first insulating layer 11 and the pads that constitute the wiring layer 12. The second insulating layer 13 mainly consists of an insulating resin such as a photosensitive epoxy resin or an acrylic resin. The thickness of the second insulating layer 13 is, for example, about 15 to 35 μm.

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

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

[0019] The optical integrated circuit 20 is disposed on the first insulating layer 11 exposed within the opening 13x and is electrically connected to the pads constituting the wiring layer 12. Specifically, the optical integrated circuit 20 is flip-chip mounted in a face-down state on the upper surface 11a of the first insulating layer 11. That is, the electrodes 22 of the optical integrated circuit 20 are joined to the pads constituting the wiring layer 12 via a conductive bonding material 30 such as solder.

[0020] The optical fiber 40 is disposed adjacent to the optical integrated circuit 20 on the first insulating layer 11 exposed within the opening 13x. The number of optical fibers 40 may be one or more arbitrary numbers, but in the illustrated example, four optical fibers 40 are juxtaposed at a predetermined interval. The optical fiber 40 extends outside the first insulating layer 11 across one side of the upper surface 11a of the first insulating layer 11 in a plan view. That is, the opening 13x reaches one side of the upper surface 11a of the first insulating layer 11. In other words, in a plan view, the second insulating layer 13 located around the opening 13x is not frame-shaped but is open in one direction. Thereby, the optical fiber 40 can extend outside the first insulating layer 11 across one side of the upper surface 11a of the first insulating layer 11 exposed from the opening 13x 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 a 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 positioned on the first insulating layer 11 exposed within the opening 13x, and sandwiches the optical fiber 40 between itself and the first insulating layer 11. The fixing member 50 is made of, for example, glass. The fixing member 50 has, for example, an elongated groove 50x on the surface facing the upper surface 11a of the first insulating layer 11. The cross-section of the groove 50x, when cut perpendicular to the longitudinal direction, is, for example, V-shaped. The cross-section of the groove 50x, when cut perpendicular to the longitudinal direction, may be U-shaped or other than V-shaped. The optical fiber 40 is in contact with the upper surface 11a of the first insulating layer 11 and the inner wall of the groove 50x. As a result, the optical fiber 40 is held between the first insulating layer 11 and the fixing member 50.

[0023] The resin portion 60 is located on the upper surface 11a of the first insulating layer 11 that is exposed within the opening 13x. 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 first insulating layer 11, and around the optical fiber 40 between the inner wall of the groove 50x and the upper surface 11a of the first insulating layer 11. This improves the connection reliability between the optical integrated circuit 20 and the first insulating layer 11, and allows the fixing member 50 to be joined to the first insulating layer 11.

[0024] To form the resin portion 60, liquid resin is applied to the opening 13x of the second insulating layer 13 in the state shown in Figures 1 and 2, where the resin portion 60 is not present. The liquid resin flows around the bonding material 30 between the optical integrated circuit 20 and the upper surface 11a of the first insulating layer 11, and around the optical fiber 40 between the inner wall of the groove 50x and the upper surface 11a of the first insulating layer 11. By curing the resin in this state, the resin portion 60 shown in Figures 1 and 2 is formed. As the liquid resin flows, the inner surface of the opening 13x acts as a barrier, preventing the resin from flowing into unwanted areas.

[0025] As the material for the resin part 60 needs to be poured into a narrow space, it is preferable to use a material with good fluidity. For example, an insulating resin such as epoxy resin can be used as the material for the resin part 60.

[0026] 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 first insulating layer 11. Furthermore, the optical fiber 40 is sandwiched between the first insulating 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.

[0027] Furthermore, in the optical-electric combined-signal device 1, the first insulating layer 11 also serves as the lower component of the structure that fixes the optical fiber 40, making it possible to reduce the height of the optical-electric combined-signal device 1. In addition, in the optical-electric combined-signal device 1, the first insulating layer 11 also serves as the lower component of the structure that fixes the optical fiber 40, and the fixing member 50 is arranged on the first insulating layer 11, making it possible to miniaturize the optical-electric combined-signal device 1 in the direction in which the optical fiber 40 extends.

[0028] 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.

[0029] <Variation 1 of the First Embodiment> Modification 1 of the first embodiment shows an example of an optical-electric mixed-signal device in which the optical fiber is not in contact with the upper surface of the first insulating layer. Figure 4 is a cross-sectional view illustrating an optical-electric mixed-signal device according to Modification 1 of the first embodiment.

[0030] Referring to Figure 4, the optical-electric combined-signal device 1A differs from the optical-electric combined-signal device 1 in that the optical fiber 40 is in contact with the resin portion 60 located on the upper surface 11a of the first insulating layer 11 and the inner wall of the groove 50x of the fixing member 50. The optical fiber 40 is not in contact with the upper surface 11a of the first insulating layer 11. The optical fiber 40 is located around the bonding material 30 between the optical integrated circuit 20 and the upper surface 11a of the first insulating layer 11, which is the same as in the optical-electric combined-signal device 1.

[0031] Thus, the resin portion 60 may be interposed between the optical fiber 40 and the upper surface 11a of the first insulating layer 11. For example, by performing active alignment before curing the resin portion 60 to position the optical fiber 40 so that it makes optical connection with the optical waveguide of the optical integrated circuit 20, and then curing the resin portion 60, the alignment of the optical fiber 40 and the optical waveguide of the optical integrated circuit 20 can be easily performed.

[0032] 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]

[0033] 1.1A Photoelectric Mixed-Platform 10 Wiring board 11. First insulating layer 11a Top side 12 wiring layer 13. Second insulating layer 13x opening 20 Optical Integrated Circuits 21 Main unit 22 electrodes 30 Bonding material 40 Optical Fibers 50 Fixing member 50x grooves 60 Resin part

Claims

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

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

3. The fixing member has a groove on the surface facing the upper surface of the first insulating layer, The optical fiber is in contact with the resin portion located on the upper surface of the first insulating layer and the inner wall of the groove, as described in claim 1.

4. The second insulating layer is disposed on the first insulating layer and has an opening that exposes a part of the upper surface of the first insulating layer and the pad, The optical integrated circuit, the optical fiber, and the fixing member are arranged on the first insulating layer exposed in the opening, as described in claim 2.

5. Having a resin part located within the aforementioned opening, The optical integrated circuit is bonded to the pad via a conductive bonding material. The photoelectric mixed-signal apparatus according to claim 4, wherein the resin portion is located at least around the bonding material between the optical integrated circuit and the upper surface of the first insulating layer, and around the optical fiber between the inner wall of the groove and the upper surface of the first insulating layer.

6. The second insulating layer is disposed on the first insulating layer and has an opening that exposes a part of the upper surface of the first insulating layer and the pad, The optical integrated circuit, the optical fiber, and the fixing member are arranged on the first insulating layer exposed in the opening, as described in claim 3.

7. The optical integrated circuit is bonded to the pad via a conductive bonding material. The photoelectric mixed-signal apparatus according to claim 6, wherein the resin portion is located at least within the opening around the bonding material between the optical integrated circuit and the upper surface of the first insulating layer, and around the optical fiber between the inner wall of the groove and the upper surface of the first insulating layer.

8. The opening extends to one side of the upper surface of the first insulating layer. The optical fiber extends to the outside of the first insulating layer, in a plan view, straddling one side exposed from the opening, as described in any one of claims 4 to 7.

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