Optical device and optical transceiver module

Abstract

To provide an optical device which realizes both miniaturization and high speed.SOLUTION: The optical device includes an optical integrated circuit chip and a resin member. The optical integrated circuit chip has a first surface on which an optical circuit and a first electrical wiring are formed. The resin member is in contact with at least a part of the optical integrated circuit chip. A dam structure is formed along an outer periphery of the first surface. At least a part of the optical circuit is configured using a heterogeneous material different from a material of the optical integrated circuit chip. The resin member seals the optical integrated circuit chip without sealing a region inside the dam structure on the first surface. A second electric wiring is formed on the surface of the resin member. The second electrical wire is electrically connected to the first electrical wire.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical device and an optical transmitter / receiver module including an optical integrated circuit chip. [Background technology]

[0002] In recent years, there has been a demand for faster and more compact optical devices that convert electrical and optical signals in long-distance optical communications or optical data communications between servers. For example, there is a demand for optical devices to be housed in small components called form factors that can be inserted and removed from optical communication equipment. Furthermore, new high-density packaging technologies at the optical chip level, known as co-packaged optics (CPO) or chiplets, have been developed. To advance such high integration and high density, optical integrated circuit chips, typified by silicon photonics, have attracted attention.

[0003] In silicon photonics optical integrated circuit chips, optical modulators, photodetectors, multiplexers, demultiplexers, and optical waveguides are formed with high precision and high integration using semiconductor processes. However, with the significant increase in signal transmission rates per channel, it is becoming difficult to further increase the modulation speed in optical devices that use silicon materials. For this reason, a configuration has been proposed in which optical modulators and other components are formed on a silicon chip using a material other than silicon that is capable of high-speed operation (for example, Patent Document 1).

[0004] In addition, with the increase in signal transmission rates, there is a demand for a configuration that shortens the transmission distance of electrical signals within a device. For example, it is desirable to shorten the transmission distance between an optical modulator and a driver chip, and between a light-receiving element and an amplifier (TIA: Trans Impedance Amplifier) ​​chip. From this perspective, in addition to the conventional planar mounting structure, a structure in which chips are mounted in a direction perpendicular to the substrate (e.g., a stacked structure) has been proposed (e.g., Non-Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6453796 [Non-patent literature]

[0006] [Non-Patent Document 1] SBN Gourikutty et al., 2023 IEEE 73rd Electronic Components and Technology Conference (ECTC), 207-211. Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, technologies have been proposed that use stacked structures to shorten the transmission distance between the optical modulator and driver chip, and between the light-receiving element and TIA chip. However, in conventional technologies, the molding resin is formed all the way to the surface of the optical integrated circuit chip. This increases the dielectric constant around the optical waveguides and wiring that make up the optical element, which can hinder high-speed operation.

[0008] An object of one aspect of the present invention is to provide an optical device that achieves both miniaturization and high speed. [Means for solving the problem]

[0009] An optical device according to one aspect of the present invention comprises an optical integrated circuit chip having a first surface on which an optical circuit and first electrical wiring are formed, and a resin member in contact with at least a portion of the optical integrated circuit chip. A dam structure is formed along the periphery of the first surface. At least a portion of the optical circuit is made of a different material from the material of the optical integrated circuit chip. The resin member seals the optical integrated circuit chip without sealing the region inside the dam structure on the first surface. A second electrical wiring is formed on the surface of the resin member. The second electrical wiring is electrically connected to the first electrical wiring. [Effects of the Invention]

[0010] According to the above-described embodiment, it is possible to realize both a smaller size and a higher speed of the optical device. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating an example of an optical transceiver module according to an embodiment of the present invention; [Figure 2] FIG. 1 is a diagram illustrating an example of an optical integrated circuit chip. [Figure 3] 1A to 1C are diagrams (part 1) illustrating an example of a manufacturing process for an optical device according to an embodiment of the present invention. [Figure 4] 4A to 4C are diagrams (part 2) illustrating an example of a manufacturing process for an optical device according to an embodiment of the present invention. [Figure 5] 10A to 10C are diagrams (part 3) illustrating an example of a manufacturing process for an optical device according to an embodiment of the present invention. [Figure 6] 10A to 10C are diagrams (part 4) illustrating an example of a manufacturing process for an optical device according to an embodiment of the present invention. [Figure 7] 5A to 5C are diagrams showing an example of a manufacturing process for an optical device according to an embodiment of the present invention. [Figure 8] FIG. 1 is a diagram (part 1) showing a variation of a molded resin sealing structure including an optical integrated circuit chip. [Figure 9]FIG. 2 is a diagram (part 2) showing a variation of a molded resin sealing structure including an optical integrated circuit chip. [Figure 10] FIG. 10 is a diagram illustrating an example of an optical transceiver module according to a second embodiment. [Figure 11] 10A and 10B are diagrams illustrating variations of the optical transceiver module according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Fig. 1 shows an example of an optical transceiver module according to an embodiment of the present invention. The optical transceiver module 1 includes a digital signal processor (DSP) 2, a driver 3, a transistor amplifier (TIA) 4, and an optical integrated circuit chip 5. Note that the optical transceiver module 1 may further include other circuits, elements, and functions not shown in Fig. 1.

[0013] The DSP2 is one of the electrical integrated circuit chips included in the optical transceiver module 1, and generates a modulated signal from the transmission data according to the modulation method. The modulated signal contains amplitude and phase information of the transmission symbol. The driver 3 is one of the electrical integrated circuit chips included in the optical transceiver module 1, and amplifies the modulated signal to drive the optical modulator. The TIA 4 is one of the electrical integrated circuit chips included in the optical transceiver module 1, and amplifies the minute current signal output from the optical integrated circuit chip 5 and outputs it as a voltage signal. The DSP2 then demodulates the output signal of the TIA 4. Thus, the DSP2 can regenerate the received data based on the output signal of the TIA 4.

[0014] The optical integrated circuit chip 5 includes an optical modulator and an optical receiver, and is formed of silicon photonics. Furthermore, an optical circuit and electrical wiring are formed on the surface of the optical integrated circuit chip 5. The optical circuit includes an optical circuit for configuring the optical modulator and an optical circuit for configuring the optical receiver. The electrical wiring includes electrical wiring for transmitting a drive signal generated by the driver 3 and electrical wiring for transmitting an output signal from the optical receiver.

[0015] The optical modulator includes an optical waveguide circuit 11 and an optical element wiring 12 (12a). The optical waveguide circuit 11 includes at least one Mach-Zehnder interferometer. Continuous light generated by a light source (not shown) is guided to the optical waveguide circuit 11. The optical element wiring 12a is formed near a corresponding optical waveguide of the optical waveguide circuit 11. A drive signal generated by a driver 3 is applied to the optical element wiring 12a. The continuous light passing through the optical waveguide circuit 11 is modulated by the drive signal, thereby generating a modulated optical signal.

[0016] The optical waveguide circuit 11 that constitutes the optical modulator is formed from a material different from silicon. The different material is a material whose refractive index changes in response to an externally applied electric field. That is, the refractive index of the different material changes in response to the external electric field. Therefore, when a drive signal is applied to the optical element wiring 12a, the refractive index of the optical waveguide circuit 11 changes in response to the change in the electric field caused by the drive signal. This generates a modulated optical signal in response to the drive signal.

[0017] In this embodiment, the optical receiver includes a photodiode 13. An optical signal received by the optical transceiver module 1 is guided to the photodiode 13 via an optical waveguide (not shown). A current signal representing the received optical signal is generated. Here, the optical element wiring 12 (12b) is connected to the photodiode 13. The current signal generated by the photodiode 13 is propagated via the optical element wiring 12b. The photodiode 13 may also be formed from a different material than silicon.

[0018] The optical integrated circuit chip 5 is sealed with a mold resin 21. However, the region in which the optical waveguide circuit 11 and the optical element wiring 12 are formed is not sealed with the mold resin 21. In other words, even after the optical integrated circuit chip 5 is sealed with the mold resin 21, the optical waveguide circuit 11 and the optical element wiring 12 are in contact with the air around the optical integrated circuit chip 5. In the following description, the structure in which the optical integrated circuit chip 5 is sealed with the mold resin 21 may be referred to as a "molded resin sealing structure." The mold resin 21 is also an example of a resin member that contacts at least a portion of the optical integrated circuit chip 5.

[0019] A rewiring layer 22 is provided on the surface of the mold resin 21. Furthermore, mold wiring 23 is formed using the rewiring layer 22. The mold wiring 23 is electrically connected to the optical element wiring 12 formed on the optical integrated circuit chip 5. Furthermore, some of the terminals of the DSP 2, the driver 3, and the TIA 4 are connected to the mold wiring 23. Note that the periphery of the solder bumps may be sealed with underfill or the like from the viewpoint of reliability.

[0020] The molded resin sealing structure is fixed to the substrate 25 using a die attach adhesive 24 or the like. Low-speed electrical signal lines, power lines, and control lines may be realized by, for example, wire bonding. In this case, the molded resin sealing structure and the substrate 25 are electrically connected by wires. In addition, to shorten the length of the wires, the back surface of the molded resin sealing structure may be ground or polished to thin the molded resin 21. Note that the wires are omitted from FIG. 1 to make the drawing easier to understand.

[0021] A dam structure 14 is formed near the periphery of the surface of the optical integrated circuit chip 5 (the component mounting surface on which the optical waveguide circuit 11 and the optical element wiring 12 are formed). Here, the optical integrated circuit chip 5 is rectangular in shape. As an example, the dam structure 14 is formed near three of the four sides that form the periphery of the component mounting surface of the optical integrated circuit chip 5. In another embodiment, the dam structure may be formed on all four sides. Note that the top view shows dam structures 14a and 14b formed along the upper and lower sides of the optical integrated circuit chip 5. Furthermore, the cross-sectional view shows dam structure 14c formed along the side on which the driver 3 and the like are provided.

[0022] The dam structure 14 is provided to prevent the molding resin 21 from reaching the component mounting region of the optical integrated circuit chip 5 during the process of sealing the optical integrated circuit chip 5. Therefore, the dissimilar material mounted on the optical integrated circuit chip 5 is exposed to air. That is, the dissimilar material comes into contact with a substance (here, air) that has a lower relative dielectric constant than the resin. Here, the response speed of a dissimilar material used in the optical integrated circuit chip 5 (for example, lithium niobate used in an LN modulator) increases when used in contact with a substance (here, air) that has a lower relative dielectric constant.

[0023] Therefore, according to the embodiment of the present invention, the speed of the optical device can be increased. In addition, by electrically connecting devices with the shortest electrical wiring (i.e., mold wiring 23) on the mold resin 21, the transmission loss of high-speed signals can be reduced.

[0024] An optical fiber assembly member is attached to the optical transceiver module 1. At this time, the optical fiber assembly member is precisely aligned with the input / output section of the optical integrated circuit chip 5, and is fixed using a transparent adhesive or the like.

[0025] 2 shows an example of an optical integrated circuit chip 5. As described above, the optical integrated circuit chip 5 includes an optical modulator and an optical receiver. The optical modulator includes an optical waveguide circuit 11 and an optical element wiring 12a, and the optical receiver includes a photodiode 13.

[0026] The optical integrated circuit chip 5 is formed on, for example, a silicon wafer. At this time, optical waveguides and some optical elements are formed by a wafer process such as silicon photonics. Furthermore, to achieve high-speed operation, a heterogeneous material different from silicon is formed (or attached) at a predetermined position. For example, the heterogeneous material may be an oxide ferroelectric such as lithium niobate, lead lanthanum zirconate titanate, or barium titanate, or a compound semiconductor such as indium phosphide or gallium arsenide. Furthermore, the heterogeneous material may be formed by a thin-film transfer process such as microtransfer printing. In this embodiment, for example, at least a portion of the optical waveguide circuit 11 constituting the optical modulator is formed from the heterogeneous material.

[0027] Furthermore, optical element wiring 12 is formed on the surface of the optical integrated circuit chip 5. The optical element wiring 12 includes a conductor pattern (optical element wiring 12a) that propagates a drive signal output from the driver 3 shown in Fig. 1. The optical element wiring 12 also includes a conductor pattern (optical element wiring 12b) that propagates a current signal generated by the photodiode 13.

[0028] Dam structures 14 (14a to 14d) are formed on the surface of the optical integrated circuit chip 5. The dam structure 14 is formed along the outer periphery of the optical integrated circuit chip 5 on the component mounting surface where the optical waveguide circuit 11, the optical element wiring 12, and the photodiode 13 are formed. The dam structure 14 is also formed so as to surround the optical waveguide circuit 11, the optical element wiring 12, and the photodiode 13. The height H of the dam structure 14 is the same as or slightly higher than the height of the protrusion structure formed on the surface of the optical integrated circuit chip 5. In other words, the height of the dam structure 14 relative to the surface of the optical integrated circuit chip 5 is equal to or higher than the height of the protrusion structure formed on the surface of the optical integrated circuit chip 5. The protrusion structure formed on the surface of the optical integrated circuit chip 5 is formed by the optical waveguide circuit 11 and the optical element wiring 12. Alternatively, the protrusion structure is formed by the photodiode 13.

[0029] The dam structure 14 may be formed by the same process as the optical element wiring 12, or by another process. For example, the dam structure 14 is realized by plating to a thickness of about 10 μm. In this case, the dam structure 14 may be formed by plating with Au or Cu. Then, the optical integrated circuit chip 5 on which the dam structure 14 is formed is cut out from the wafer by dicing or the like.

[0030] 3 to 7 show an example of a manufacturing process for an optical device according to an embodiment of the present invention. Here, it is assumed that the optical integrated circuit chip 5 shown in FIG. 2 is formed on a wafer and is cut out from the wafer by dicing or the like. That is, the optical integrated circuit chip 5 is prepared as shown in FIG. 3A.

[0031] As shown in Figures 3B and 3C, the optical integrated circuit chip 5 is pressed and fixed upside down onto the thermal release sheet 31. At this time, the component mounting surface of the optical integrated circuit chip 5 (the surface on which the optical waveguide circuit 11, optical element wiring 12, and photodiode 13 are formed) is pressed against the thermal release sheet 31. However, a dam structure 14 is formed on the component mounting surface of the optical integrated circuit chip 5. Therefore, in reality, the optical integrated circuit chip 5 is fixed to the thermal release sheet 31 with the dam structure 14 pressed against the thermal release sheet 31.

[0032] The optical integrated circuit chip 5 is placed in a mold of a predetermined shape while being fixed to the thermal release sheet 31. A specified amount of molding resin 21 is poured into the mold and heated to form the mold. As a result, the optical integrated circuit chip 5 is sealed with the molding resin 21, as shown in FIG. 4A. However, since the dam structure 14 is formed on the component mounting surface of the optical integrated circuit chip 5, the molding resin 21 does not fill the area inside the dam structure 14.

[0033] After the molding resin 21 has hardened, the thermal release sheet 31 is peeled off, as shown in FIGS. 4B and 4C. Here, the molding resin 21 is not filled in the area inside the dam structure 14. Therefore, the optical waveguide circuit 11, the optical element wiring 12, and the photodiode 13 are not sealed with the molding resin 21. In other words, the different materials provided on the component mounting surface of the optical integrated circuit chip 5 are exposed to air.

[0034] Next, mold wiring is formed on the mold resin sealing structure. The mold wiring is formed, for example, by a semiconductor manufacturing process. Specifically, the process is as follows.

[0035] As shown in FIG. 5A, an insulating layer 41 is formed on the upper surface of the molding resin 21. At this time, the insulating layer 41 is formed up to the edge of the optical integrated circuit chip 5. Specifically, the insulating layer 41 is formed up to the upper side of the optical element wiring 12. The insulating layer 41 is realized by, for example, a photosensitive resin. In this case, after performing a surface treatment, the insulating layer 41 is formed only in the necessary region by application by spin coating and an exposure and development process. Subsequently, as shown in FIG. 5B, openings 42 are formed at predetermined positions in the insulating layer 41. The openings 42 are formed, for example, above the pads of the optical element wiring 12 and / or control lines provided on the optical integrated circuit chip 5.

[0036] As shown in FIG. 5C, an electrical wiring layer 43 of mold wiring is formed. The electrical wiring layer 43 is formed on the insulating layer 41 by a plating process. Specifically, first, a seed layer is formed on the upper surface of the insulating layer 41 and in the opening 42. The seed layer is realized by, for example, a thin film of Cu / Ti or the like. Then, a resist opening pattern for forming the electrical wiring layer is formed. That is, Cu pattern plating is performed by passing current through the seed layer in a plating bath, and then Cu wiring of the desired shape is obtained by stripping the resist and wet etching the seed layer. This forms the electrical wiring layer 43. At this time, the electrical wiring layer 43 is electrically connected to the optical element wiring 12, as shown in FIG. 5C.

[0037] As shown in FIG. 6A, an insulating layer 44 is formed on top of an electrical wiring layer 43. The method for forming the insulating layer 44 may be the same as the method for forming the insulating layer 41 shown in FIG. 5. Furthermore, molded wiring can be further formed on the upper surface of the insulating layer 44. The method for forming the molded wiring on the upper surface of the insulating layer 44 may be the same as the method for forming the electrical wiring layer 43 shown in FIG. 5. In this embodiment, as shown in FIG. 6A, openings 45 are formed at predetermined positions. Each opening 45 is used as a via, as shown in FIG. 6B. Then, pads 46 are formed to connect to each via. The surfaces of the pads 46 are preferably plated with Ni or the like so that they can withstand connection with solder bumps.

[0038] Insulating layer 41, electrical wiring layer 43, insulating layer 44, and pad 46 constitute a redistribution layer, which corresponds to redistribution layer 22 and mold wiring 23 shown in FIG. 1. In this embodiment, the redistribution layer has a two-layer structure, but may have a multi-layer structure of three or more layers. Furthermore, each pad 46 may be in direct contact with a corresponding terminal of, for example, DSP 2, driver 3, or TIA 4 shown in FIG. 1.

[0039] The electrical connection terminals on the substrate (for example, substrate 25 shown in FIG. 1) and the electrical connection terminals at the ends of the optical element wiring formed on the optical integrated circuit chip 5 may be misaligned during the molding resin sealing process. If the misalignment is large, it is preferable to use a direct writing exposure device to enlarge / reduce and rotate the pattern when forming the mold wiring layer in order to absorb the misalignment and overlap the patterns so that electrical connection can be established.

[0040] Thereafter, as shown in FIG. 7A, the back surface of the molded resin sealing structure is ground to thin the device. That is, a portion of the molded resin 21 is removed. Furthermore, as shown in FIG. 7B, the end of the optical integrated circuit chip 5 is cut off. At this time, a portion of the dam structure 14 is cut off. Specifically, the dam structure 14 formed on the side where optical input / output is performed as shown in FIG. 1 is cut off. In the example shown in FIG. 2, the dam structure 14d is cut off. Furthermore, optical end face polishing is performed.

[0041] After the above-described processing, the molded resin encapsulated structure is mounted on another substrate with a die attach adhesive using a die bonder. That is, as shown in FIG. 1, this molded resin encapsulated structure is fixed to substrate 25 using die attach adhesive 24. Electrical wiring for connection to corresponding conductor patterns on substrate 25 is also provided by wire bonding. Furthermore, optical axis alignment is performed between the optical input / output section composed of an optical waveguide on optical integrated circuit chip 5 and the optical fiber assembly member shown in FIG. 1. The optical fiber assembly member is then fixed using, for example, a transparent adhesive. In this manner, an optical device according to an embodiment of the present invention is constructed.

[0042] As described above, according to the embodiment of the present invention, high-speed operation is achieved by mounting a different material, whose refractive index changes efficiently in response to an external electric field, on the optical integrated circuit chip 5 sealed with the mold resin 21. Here, the dam structure 14 is formed along the outer periphery of the optical integrated circuit chip 5, preventing the molding resin from penetrating into the component mounting surface of the optical integrated circuit chip 5 during the molding resin sealing process. Therefore, the component mounting surface of the optical integrated circuit chip 5 can be exposed to air, resulting in a low-permittivity medium (i.e., air) surrounding the optical modulator, thereby achieving even higher speeds of the optical modulator. Additionally, the mold wiring layer formed on the upper surface of the mold resin 21 is used to form electrical terminals (pads 46) for connection to the electrical integrated circuit chips (DSP 2, driver 3, TIA 4). The signal lines transmitting high-speed signals between the optical integrated circuit chip 5 and the electrical integrated circuit chips are shortened. This results in a smaller, faster optical transceiver module 1.

[0043] 8 and 9 show variations of the molded resin sealing structure including the optical integrated circuit chip 5. Note that in Figs. 8 and 9, a cross section of a part of the molded resin sealing structure is depicted.

[0044] In the embodiment shown in Figures 2 to 7, the cross-sectional shape of the dam structure 14 is rectangular. However, the cross-sectional shape of the dam structure 14 is not limited to a rectangle. In the variation shown in Figures 8 to 9, the cross-sectional shape of the dam structure is different from that of the embodiment shown in Figures 2 to 7.

[0045] In the variation shown in Fig. 8, the cross section of the dam structure 15 is tapered. Specifically, the cross section of the dam structure 15 is wider on the lower side (or bottom side) than on the upper side (or ceiling side). In addition, the cross section of the dam structure 15 has a tapered side that faces inward from the component mounting surface of the optical integrated circuit chip 5. That is, as shown in Fig. 8A, the dam structure 15 has a tapered side on the side where optical elements (optical waveguide circuit 11, optical element wiring 12, and photodiode 13) are formed on the optical integrated circuit chip 5.

[0046] The dam structure 15 is formed by, for example, gradational exposure of a photosensitive polymer. However, the material of the dam structure 15 is not limited to polymer. That is, the dam structure 15 may be formed by pattern plating, or other dam structure components may be bonded in addition to the dam structure 14 shown in FIG. 2.

[0047] Here, there is a step between the upper surface of the mold resin 21 and the surface of the optical integrated circuit chip 5. Therefore, if the side surface of the dam structure is perpendicular to the surface of the optical integrated circuit chip 5, the insulating layer 41 may become thin at the corners of the dam structure 14, as shown in Fig. 5. In this case, there is a risk that sufficient insulation may not be achieved at the corners of the dam structure 14 (the upper right corner of the dam structure 14 in Fig. 5).

[0048] In contrast, the cross section of the dam structure 15 is tapered, with obtuse corners as shown in Fig. 8B. Therefore, the insulating layer 41 does not become thin at the corners of the dam structure 15, and the region from the upper surface of the mold resin 21 to the surface of the optical integrated circuit chip 5 can be covered without any exposure. In addition, since the insulating layer 41 is gently formed in the region from the upper surface of the mold resin 21 to the surface of the optical integrated circuit chip 5, a patterning resist can be appropriately applied in the process of forming the electrical wiring layer 43 on the insulating layer 41. This reduces the risk of disconnection of the electrical wiring layer 43 near the boundary between the mold resin 21 and the optical integrated circuit chip 5, as shown in Fig. 8C.

[0049] In the variation shown in Fig. 9 (Figs. 9A to 9C), the dam structure 16 is formed by droplets. Therefore, the cross section of the dam structure 16 has a tapered shape on both the side surface facing inward of the optical integrated circuit chip 5 and the side surface facing outward of the optical integrated circuit chip 5. Therefore, the structure shown in Fig. 9 can achieve the same effect as the structure shown in Fig. 8.

[0050] The dam structure 16 is formed, for example, by applying a resin dropwise along the outer periphery of the surface of the optical integrated circuit chip 5. In this case, the resin for forming the dam structure 16 is, for example, an epoxy resin or a polyimide resin.

[0051] <Second embodiment> 10 shows an example of an optical transceiver module according to a second embodiment of the present invention, in which an auxiliary circuit board is embedded in a molded resin.

[0052] As shown in FIG. 10A , at least one via is formed in the auxiliary circuit board 50. Conductive patterns and pads are formed on the upper and lower surfaces of the auxiliary circuit board 50, respectively. Each via electrically connects the conductive pattern formed on the upper surface of the auxiliary circuit board 50 to the conductive pattern formed on the lower surface. The auxiliary circuit board 50 is realized by, for example, an organic substrate or a ceramic substrate. Alternatively, the auxiliary circuit board 50 may be a silicon substrate or a glass substrate with a through-via formed therein. The auxiliary circuit board 50 is then sealed with a mold resin 21. Specifically, the optical integrated circuit chip 5 and the auxiliary circuit board 50 are sealed with the mold resin 21 in the same process.

[0053] As shown in FIG. 10B , the molded resin sealing structure in which the optical integrated circuit chip 5 and the auxiliary circuit board 50 are sealed is mounted on the upper surface of the substrate 25. Here, a redistribution layer 22 is formed on the upper surface of the molded resin sealing structure. Then, the electrical integrated circuit chips (DSP 2, driver 3, TIA 4) are mounted on the upper side of the redistribution layer 22. Also, a redistribution layer 26 is formed on the upper surface of the molded resin sealing structure. The redistribution layer 26 can provide connection with the conductor patterns formed on the substrate 25. Then, predetermined terminals of the electrical integrated circuit chip are electrically connected to the corresponding conductor patterns formed on the substrate 25 through vias 51 in the auxiliary circuit board 50.

[0054] 10, one auxiliary circuit board 50 is provided for each electrical integrated circuit chip, but the second embodiment is not limited to this configuration. That is, one auxiliary circuit board 50 may be provided for a plurality of electrical integrated circuit chips.

[0055] According to the second embodiment, the connection between each electrical integrated circuit chip and the circuit on the substrate 25 can be realized by a ball grid array (BGA) or Cu pillars, instead of wire bonding. This configuration therefore contributes to the miniaturization of the substrate 25 or the optical transceiver module 1. In addition, because the connection is realized using vias, which have a smaller inductance component than wires, loss in high-frequency signal lines is suppressed, and an increase in impedance of the power supply line is also suppressed.

[0056] The terminals (for example, pads or under bump metal (UBM)) of the auxiliary circuit board 50 can be used as they are on the upper surface side of the molded resin sealing structure. On the lower surface side of the molded resin sealing structure, connection terminals to the lower substrate, such as Cu pillars, may be formed by a mold wiring process.

[0057] 11 shows a variation of the optical transceiver module according to the second embodiment. In this example, one or more circuit elements are provided for vias 51 inside an auxiliary circuit board 50. Specifically, as shown in FIG. 11A, a capacitor C, an inductor L, and / or a resistor R are formed inside the auxiliary circuit board 50. Then, as shown in FIG. 11B, the auxiliary circuit board 50 on which the capacitor C, the inductor L, and / or the resistor R are formed is sealed with molded resin 21.

[0058] The capacitor C is realized, for example, by forming a capacitance between layers or in a wiring layer on the surface of the auxiliary circuit board 50. In this case, the capacitance may be formed using a ferroelectric material. The inductor L is realized, for example, by a rectangular spiral coil structure. The resistor R is realized, for example, by arranging a material with high resistivity within a layer of the auxiliary circuit board 50.

[0059] The configuration shown in Figure 11 enables a high-density mounting structure without using chip components. By forming a capacitor C inside the board, a large capacitance component is added to the power supply wiring, thereby reducing the power supply impedance. By introducing an inductor L into part of the signal line, it becomes possible to reduce transmission loss caused by peaks at specific frequencies due to resonance in the signal line. Resistor R can function as a damping resistor that suppresses resonance in the signal line and resonance caused by the power supply impedance. [Explanation of symbols]

[0060] 1 Optical transceiver module 2 Digital Signal Processor (DSP) 3 Driver 4 Transistor Amplifier (TIA) 5. Optical integrated circuit chip 11 Optical waveguide circuit 12 (12a, 12b) Optical element wiring 13 Photodiode 14~16 Dam Structure 21 Molding resin 22 Redistribution layer 23 Molded wiring 31 Heat release sheet 41, 44 Insulating layer 42, 45 Opening 43 Electrical wiring layer 46 pads 50 Auxiliary Circuit Board 51 Beer

Claims

1. an optical integrated circuit chip having a first surface on which an optical circuit and a first electrical wiring are formed; a resin member in contact with at least a portion of the optical integrated circuit chip, a dam structure formed along the periphery of the first surface; At least a part of the optical circuit is made of a material different from a material of the optical integrated circuit chip, the resin member seals the optical integrated circuit chip without sealing the region inside the dam structure on the first surface, a second electrical wiring is formed on a surface of the resin member; The second electrical wiring is electrically connected to the first electrical wiring. An optical device characterized by:

2. The height of the dam structure relative to the first surface is equal to or greater than the height of the optical circuit and the first electrical wiring.

2. The optical device according to claim 1.

3. the first surface is rectangular in shape; The dam structure is formed in the vicinity of at least three of four sides that form the periphery of the first surface.

2. The optical device according to claim 1.

4. The refractive index of the dissimilar material changes in response to an external electric field.

2. The optical device according to claim 1.

5. the optical circuit includes an optical waveguide circuit formed of the different materials, at least a portion of the first electrical wiring is formed in the vicinity of the optical waveguide circuit; The optical waveguide circuit and at least a part of the first electrical wiring formed in the vicinity of the optical waveguide circuit constitute an optical modulator.

5. The optical device according to claim 4.

6. The cross section of the dam structure has a tapered shape on the side facing inward of the first surface.

2. The optical device according to claim 1.

7. The second electrical wiring includes a pad for electrically connecting with a terminal of an electrical integrated circuit chip.

2. The optical device according to claim 1.

8. the second electrical wiring is formed on a first surface of the resin member, a third electrical wiring is formed on a second surface of the resin member; an auxiliary circuit board having vias formed therein is embedded in the resin member; The second electrical wiring and the third electrical wiring are electrically connected by the via.

2. The optical device according to claim 1.

9. A capacitor, an inductor, or a resistor is electrically connected to the via in the auxiliary circuit board.

9. The optical device according to claim 8.

10. an optical integrated circuit chip having a first surface on which an optical circuit and a first electrical wiring for forming an optical modulator and an optical receiver are formed; a resin member in contact with at least a portion of the optical integrated circuit chip; a driver chip for driving the optical modulator; an amplifier chip for amplifying the output signal of the optical receiver; a digital signal processor chip for controlling the driver chip and for processing an output signal of the amplifier chip; a dam structure formed along the periphery of the first surface; At least a part of the optical circuit is made of a material different from a material of the optical integrated circuit chip, the resin member seals the optical integrated circuit chip without sealing the region inside the dam structure on the first surface, a second electrical wiring is formed on a surface of the resin member; a terminal of the driver chip, a terminal of the amplifier chip, and a terminal of the digital signal processor chip are electrically connected to the second electrical wiring on the resin member, respectively; The second electrical wiring is electrically connected to the first electrical wiring. An optical transceiver module characterized by:

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