JP2009139758A - Opto-electric hybrid package and opto-electric hybrid module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an opto-electric hybrid package and an opto-electric hybrid module capable of reliably reducing loss and degradation of optical signals. <P>SOLUTION: The opto-electric hybrid package 2 includes a solder ball 49, an optical device 24, a protruding section 53, and an optical waveguide structure 71. The solder ball 49 is bonded on a solder ball bonding section 48 and also connected to a substrate 61 with an optical waveguide. The optical device 24 is mounted on an optical device mounting section 56, with a light emitting section 25 of the device opposing to an optical waveguide 81. The protruding section 53 protrudes from the back face 13 of a wiring board 10 toward the substrate 61 with the optical waveguide. The optical waveguide structure 71 includes a core and a clad and penetrates the principal face 12 of the wiring board 10 and the top end face 54 of the protruding section 53. A level difference A1 from the surface of the solder ball bonding section 48 to the top end face 54 of the protruding section 53 is a half or larger than the maximum diameter A2 of the solder ball 49. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an opto-electric hybrid package and an opto-electric hybrid module that can be mounted on a substrate with an optical waveguide provided with an optical waveguide serving as an optical path through which an optical signal propagates.

  In recent years, with the development of information communication technology represented by the Internet and the dramatic improvement in the processing speed of information processing apparatuses, there is an increasing need for transmitting and receiving large-capacity data such as images. An information transmission speed of 10 Gbps or higher is desirable to exchange such a large amount of data freely through an information communication facility, and great expectations are placed on optical communication technology as a technology that can realize such a high-speed communication environment. On the other hand, in recent years, signal transmission paths at relatively short distances such as connections between wiring boards in devices, connections between semiconductor chips in wiring boards, connections within semiconductor chips, and the like have recently been transmitted at high speed. It is desired. For this reason, it is thought that it is ideal to shift from the conventionally common metal cable or metal wiring to optical transmission using an optical waveguide or the like.

In recent years, various opto-electric hybrid modules that include an optical element, a wiring board that supports the optical element, a substrate with an optical waveguide that supports the optical waveguide, and the like that perform optical communication between the optical waveguide and the optical element have been proposed. (For example, refer to Patent Documents 1 to 3). In Patent Document 1, an optical semiconductor element (optical element) that transmits and receives an optical signal is mounted, and a circuit wiring board (wiring board) provided with an optical input / output through-hole through which the optical signal passes is connected to a ball electrode (solder). A structure mounted on an electro-optical wiring substrate (substrate with an optical waveguide) via a ball) has been proposed. In Patent Document 2, an optical semiconductor module (photoelectric hybrid package) in which a surface emitting laser element array (optical element) and a light receiving element array (optical element) are mounted on the lower surface of a module substrate (wiring substrate) is connected via a solder ball. A structure mounted on a core substrate (substrate with an optical waveguide) has been proposed. In Patent Document 3, an optical waveguide structure that penetrates a package and an optical waveguide structure that penetrates the board are connected by solder bumps on the board by solder bumps and a self-alignment effect when the solder bumps are reflowed. The structure which has arrange | positioned the part on the straight line is proposed.
Japanese Patent Laying-Open No. 2005-79385 (FIGS. 1, 3, etc.) JP-A-2005-44970 (FIG. 1 etc.) Japanese Patent No. 3801921 (FIG. 1 etc.)

  However, the conventional techniques described in Patent Documents 1 to 3 have the following problems. That is, even if the wiring board is mounted on the board with the optical waveguide, a large space (gap) is generated between the wiring board and the optical waveguide due to the height of the solder balls. As a result, loss (coupling loss) and degradation of the optical signal are likely to occur when the optical signal propagates through the gap.

  Therefore, in the prior art described in Patent Document 1, a technique for reducing loss and deterioration of an optical signal by providing a lens on a wiring board to reliably propagate the optical signal has been proposed. However, the lens requires high processing accuracy, and the provision of the lens increases the number of parts and man-hours, resulting in an increase in manufacturing cost. Moreover, in the structure described in Patent Document 1, since the optical signal is condensed when passing through the lens, it is difficult to position the wiring board so as not to cause an optical axis shift when the wiring board is mounted on the substrate with the optical waveguide. It is. Therefore, there is a need for new solutions for preventing loss and degradation of optical signals.

  The present invention has been made in view of the above problems, and an object thereof is to provide an opto-electric hybrid package and an opto-electric hybrid module that can reliably reduce loss and deterioration of optical signals.

  Means for solving the above problems (means 1) include the following. An opto-electric hybrid package (2, 3, 4, 126) that can be mounted on a substrate with optical waveguide (61) having an optical waveguide (81) serving as an optical path through which an optical signal propagates, the main surface (12) and A wiring board (10, 100, 110) having a back surface (13) located on the opposite side of the main surface (12), and a solder ball located on the back surface (13) of the wiring board (10, 100, 110) A plurality of solder balls (49) which are bonded onto the bonding portion (48) and connected to the substrate with optical waveguide (61) when mounted on the substrate with optical waveguide (61), a light emitting portion (25) and a light receiving portion The wiring board (10, 100, 110) in a state where at least one of the light emitting portions (25) and the light receiving portion is directed toward the optical waveguide (81). Light located on surface (12) From the back surface (13) side of the optical element (24, 27) mounted on the child mounting portion (55, 56) and the wiring substrate (10, 100, 110) to the substrate (61) side with the optical waveguide A protruding portion (53) formed on the wiring board (10, 100, 110) so as to protrude, a core (72) serving as an optical path through which an optical signal propagates, and a clad (73) surrounding the core (72). And an optical waveguide structure portion (71) penetrating the main surface (12) of the wiring substrate (10, 100, 110) and the tip surface (54) of the protruding portion (53), and the solder ball bonding The step (A1) between the surface of the portion (48) and the tip surface (54) of the protrusion (53) is more than half the maximum diameter (A2) of the solder ball (49). An opto-electric hybrid package.

  Therefore, according to the opto-electric hybrid package of means 1, the step between the surface of the solder ball joint and the tip end surface of the protrusion is at least half the maximum diameter of the solder ball joined on the solder ball joint. is there. For this reason, when an opto-electric hybrid package is mounted on a substrate with an optical waveguide, a space generated between the tip end surface of the protruding portion and the optical waveguide provided in the substrate with the optical waveguide is reduced. Along with this, the optical path connecting the optical waveguide structure and the optical waveguide that penetrates the tip surface of the protruding portion is shortened, so that the loss and deterioration of the optical signal are reliably reduced when the optical signal propagates through the space. be able to.

  Further, when the optical waveguide is exposed on the surface of the substrate with the optical waveguide, a step from the surface of the solder ball joint portion to the tip end surface of the protruding portion is not larger than the maximum diameter of the solder ball. Is preferred. In this way, even if the opto-electric hybrid package is mounted on the substrate with an optical waveguide, the protruding portion is less likely to contact the substrate with the optical waveguide.

  On the other hand, when the optical waveguide is built in the substrate with the optical waveguide, an opening for exposing the optical path changing portion of the optical waveguide is formed in the substrate with the optical waveguide, and the protrusion protrudes from the surface of the solder ball joint portion. Preferably, the step with respect to the tip surface of the part is larger than the maximum diameter of the solder ball, and the protruding part can be inserted into the opening. In this way, the optical path connecting the optical waveguide structure portion and the optical waveguide penetrating the distal end surface of the protruding portion is surely shortened, so that loss and deterioration of the optical signal can be more reliably reduced.

  For example, a resin wiring board, a ceramic wiring board, a glass wiring board, or a metal wiring board can be used as the wiring board constituting the opto-electric hybrid package, but a resin wiring board is preferable in consideration of cost. In addition, when using a ceramic wiring board with higher thermal conductivity than a resin wiring board, the wiring board is less likely to be deformed due to thermal expansion, so when an optical element is mounted on the optical element mounting portion, It becomes easy to hold the optical element, the optical waveguide structure, and the optical waveguide in an aligned state. In addition, since the generated heat is efficiently dissipated, when an optical element is connected to the optical element mounting part, the emission wavelength shift due to the deterioration of heat dissipation is avoided, and the operation stability and reliability are excellent. A wiring board can be realized.

  Preferable examples of such resin wiring boards include wiring boards made of EP resin (epoxy resin), PI resin (polyimide resin), BT resin (bismaleide-triazine resin), PPE resin (polyphenylene ether resin) and the like. In addition, a wiring board made of a composite material of these resins and organic fibers such as glass fibers (glass woven fabric or glass nonwoven fabric) or polyamide fibers may be used. Further, preferable examples of the ceramic wiring board include wiring boards made of alumina, aluminum nitride, silicon nitride, boron nitride, beryllia, mullite, low-temperature fired glass ceramic, glass ceramic, and the like. Preferable examples of the metal wiring board include a wiring board made of copper, a wiring board made of a copper alloy, a wiring board made of a single metal other than copper, and a wiring board made of an alloy other than copper.

  It is preferable that a semiconductor integrated circuit element mounting region in which a semiconductor integrated circuit element can be mounted is set on the main surface side of the wiring board. This shortens the wiring connecting the optical element mounted on the optical element mounting portion and the semiconductor integrated circuit element mounted in the semiconductor integrated circuit element mounting region. Here, “semiconductor integrated circuit element” refers to an element mainly used as a microprocessor of a computer or the like.

  In addition, a first recess opening on the main surface side of the wiring substrate is formed, the semiconductor integrated circuit element mounting region is set on the bottom surface of the first recess, and opening is made on the bottom surface of the first recess. A second recess is formed, the optical element mounting portion is set on the bottom surface of the second recess, and a semiconductor integrated circuit element mounted in the semiconductor integrated circuit element mounting region is placed on the optical element mounting portion. It is preferable that a heat dissipating means is provided on the main surface of the wiring board to dissipate heat of the semiconductor integrated circuit element to the outside. In this way, since the heat of the semiconductor integrated circuit element is released by the heat dissipation means and reduced, the adverse effect of the heat of the semiconductor integrated circuit element on the optical element can be more reliably reduced, and the reliability of the optical element is further increased. improves. In addition, since the semiconductor integrated circuit element is disposed in the first recess and the optical element is disposed in the second recess, the opto-electric hybrid package is less likely to be thick even if a heat dissipating means is provided. Further, the second recess is formed at a location on the main surface side of the wiring board and on the opposite side of the protrusion, and the area of the second recess is larger than the area of the tip surface of the protrusion. Small is preferable. When the protrusion is formed at a location where the solder ball joint does not exist, the thickness of the portion where the protrusion is located on the wiring board is larger than the thickness of the portion where the solder ball joint is located on the wiring board. It is likely that it is thick. Therefore, even if the second concave portion is formed at the above-described location, the strength reduction of the wiring board is prevented.

  The wiring board constituting the opto-electric hybrid package is preferably a multilayer wiring board provided with a resin insulating layer and a metal conductor layer. The metal conductor layer may be formed on the main surface or the back surface, or may be formed inside the substrate. Further, in order to achieve interlayer connection between these metal conductor layers, a through-hole conductor may be formed inside the substrate. The metal conductor layer and the through-hole conductor are, for example, conductive metal paste made of gold (Au), silver (Ag), copper (Cu), platinum (Pt), tungsten (W), molybdenum (Mo), or the like. Is formed by printing or filling. An electric signal flows through such a metal conductor layer. In addition to such a multilayer wiring board, for example, it is allowed to use a build-up multilayer wiring board having a build-up layer formed by alternately laminating resin insulating layers and metal conductor layers on the surface layer of the core portion. The This makes it easy to increase the density of the wiring board. When the semiconductor integrated circuit element mounting area is set on the main surface side, the optical element is connected to the semiconductor integrated circuit element mounted in the semiconductor integrated circuit element mounting area via the build-up multilayer wiring board. Electrically connected.

  The solder ball joint portion and the optical element mounting portion are preferably metal layers formed of, for example, a conductive metal. Although it does not specifically limit as said electroconductive metal, For example, 1 type, or 2 or more types of metals selected from copper, gold | metal | money, silver, platinum, palladium, nickel, tin, lead, titanium, tungsten, molybdenum, tantalum, niobium etc. Can be mentioned. Examples of the conductive metal composed of two or more metals include solder that is an alloy of tin and lead. Lead-free solder (for example, Sn—Sb solder, Sn—Ag solder, Sn—Ag—Cu solder, Sn—Ag—Bi solder, Sn—Ag) as a conductive metal composed of two or more metals. -Bi-Cu solder, Sn-Zn solder, Sn-Zn-Bi solder, Au-Ge solder, Au-Sn solder, Au-Si solder, etc. may be used. Examples of the method for forming the solder ball joint portion and the optical element mounting portion include etching, plating, metal paste printing and baking, metal foil sticking, sputtering, vapor deposition, and ion plating.

  The plurality of solder balls are formed of a solder alloy. The solder alloy is appropriately selected according to the material such as a solder ball joint, a connection terminal of a substrate with an optical waveguide, etc. It is formed of Sn—Sb solder, Sn—Ag solder, Sn—Ag—Cu solder, Au—Ge solder, Au—Sn solder, Au—Si solder or the like. In particular, the plurality of solder balls are preferably made of the above-described lead-free solder. In this way, since the solder balls do not contain lead, the load on the environment of the wiring board can be reduced.

  The maximum diameter of the solder ball is set to, for example, 500 μm or more. If the maximum diameter of the solder balls is less than 500 μm, the space formed between the protruding portion and the substrate with the optical waveguide becomes too small when the opto-electric hybrid package is mounted on the substrate with the optical waveguide. There is a risk of contact with the substrate with the optical waveguide. In addition, since the surface of the substrate with the optical waveguide (connection surface with the solder ball) is often wavy, if the maximum diameter of the solder ball is about 100 μm, for example, the solder ball cannot be connected to the substrate with the optical waveguide. .

  The opto-electric hybrid package includes an optical element mounted on the optical element mounting portion. One or more optical elements are mounted according to the number of optical element mounting portions. As the mounting method, for example, a technique such as wire bonding or flip chip bonding can be employed, and in particular, flip chip bonding is preferably employed. In this way, reliability and electrical characteristics are improved as compared with wire bonding. In addition, when wire bonding is employed, the wire becomes long when the optical element is thick. In addition, as an optical element (namely, light emitting element) which has a light emission part, for example, a light emitting diode (Light Emitting Diode; LED), a semiconductor laser diode (Laser Diode; LD), a surface emitting laser (Vertical Cavity Surface Emitting Laser; VCSEL) Etc. These light emitting elements have a function of converting an inputted electric signal into an optical signal and then emitting the optical signal from a light emitting portion toward a predetermined portion. On the other hand, examples of an optical element having a light receiving portion (that is, a light receiving element) include a pin photodiode (pin PD) and an avalanche photodiode (APD). These light receiving elements have a function of causing an optical signal to be incident on the light receiving unit, converting the incident optical signal into an electric signal, and outputting the electric signal. The optical element may have both a light emitting unit and a light receiving unit. Examples of suitable materials used for the optical element include Si, Ge, InGaAs, GaAsP, and GaAlAs. Such an optical element (particularly a light emitting element) is operated by an operation circuit. The optical element and the operation circuit are electrically connected through, for example, a conductor layer (the metal conductor layer) formed on the wiring board.

  The opto-electric hybrid package includes the optical waveguide structure. The opto-electric hybrid package may include only one optical waveguide structure portion or may include two or more optical waveguide structure portions. The optical waveguide structure section has a core that is an optical path through which an optical signal propagates and a cladding that surrounds the core. For example, an organic optical waveguide structure section made of a polymer material or the like, an inorganic optical waveguide structure section made of quartz glass, a compound semiconductor, or the like There is an optical waveguide structure portion of the system. As the polymer material, a photosensitive resin, a thermosetting resin, a thermoplastic resin, or the like can be selected. Specifically, a polyimide resin such as a fluorinated polyimide, an epoxy resin, a UV curable epoxy resin, a PMMA ( Polymethyl methacrylate), acrylic resins such as deuterated PMMA, deuterated fluorinated PMMA, polyolefin resins, and the like are suitable.

  As another means (means 2) for solving the above-mentioned problem, there is the following. A substrate with an optical waveguide (61) having an optical waveguide (81) serving as an optical path through which an optical signal propagates, and an opto-electric hybrid package with optical elements (2, 3, and 3) mounted on the substrate with optical waveguide (61) 4 and 126), wherein the opto-electric hybrid package (2, 3, 4, 126) with an optical element includes a main surface (12) and the main surface (12). A wiring board (10, 100, 110) having a back surface (13) located on the opposite side of the wiring board, and a solder ball joint (48) located on the back surface (13) of the wiring board (10, 100, 110). And a plurality of solder balls (49) connected to the substrate with optical waveguide (61) when mounted on the substrate with optical waveguide (61), and at least one of the light emitting portion (25) and the light receiving portion The light emitting part (2 ) And at least one of the light receiving portions facing the optical waveguide (81), the optical element mounting portions (55, 56) located on the main surface (12) of the wiring board (10, 100, 110). And the optical element (24, 27) mounted on the wiring board (10, 100, 110) and the wiring board (10, 100, 110) so as to protrude from the back surface (13) side to the substrate with optical waveguide (61) side. A protrusion (53) formed in (10, 100, 110), a core (72) serving as an optical path through which an optical signal propagates, and a clad (73) surrounding the core (72); 10, 100, 110) and an optical waveguide structure portion (71) penetrating the tip end surface (54) of the protruding portion (53), and from the surface of the solder ball joint portion (48). The front end surface (54) of the protrusion (53) Opto-electric hybrid module, wherein the step (A1) is the maximum diameter (A2) more than half the size of the solder balls (49) between.

  Therefore, according to the opto-electric hybrid module of means 2, the step between the surface of the solder ball joint and the tip end surface of the protrusion is at least half the maximum diameter of the solder ball joined on the solder ball joint. Therefore, the space generated between the protruding portion and the optical waveguide provided in the substrate with the optical waveguide is reduced. Along with this, the optical path connecting the optical waveguide structure and the optical waveguide that penetrates the tip surface of the protruding portion is shortened, so that the loss and deterioration of the optical signal are reliably reduced when the optical signal propagates through the space. be able to.

  Here, as the substrate with an optical waveguide, for example, a resin substrate, a ceramic substrate, a glass substrate, or a metal substrate can be used, but a resin substrate is preferable in consideration of cost. The substrate with an optical waveguide is preferably a wiring substrate with an optical waveguide provided with an insulating layer and a conductor layer, and particularly preferably a multilayer wiring substrate. In addition to such a wiring board, for example, it is allowed to use a build-up multilayer wiring board having a build-up layer formed by alternately laminating insulating layers and conductor layers on the surface layer of the core portion.

  The substrate with an optical waveguide includes the optical waveguide. The substrate with an optical waveguide may include only one optical waveguide, or may include two or more optical waveguides. An optical waveguide refers to a plate-like or film-like member having a core serving as an optical path through which an optical signal propagates and a clad surrounding the core. For example, an organic optical waveguide made of a polymer material, quartz glass or a compound There are inorganic optical waveguides made of semiconductors and the like. As the polymer material, a photosensitive resin, a thermosetting resin, a thermoplastic resin, or the like can be selected. Specifically, a polyimide resin such as a fluorinated polyimide, an epoxy resin, a UV curable epoxy resin, a PMMA ( Polymethyl methacrylate), acrylic resins such as deuterated PMMA, deuterated fluorinated PMMA, polyolefin resins, and the like are suitable.

[First Embodiment]

  Hereinafter, the opto-electric hybrid module according to the first embodiment embodying the present invention will be described in detail with reference to FIGS.

  As shown in FIG. 1 to FIG. 4, the opto-electric hybrid module 1 of the present embodiment includes three opto-electric modules with optical elements on an upper surface 62 (front surface) of a wiring board 61 with optical waveguide (substrate with optical waveguide). It is configured by mounting mixed packages 2, 3 and 4.

  The wiring substrate 61 with an optical waveguide according to the present embodiment is a plate member having a substantially rectangular shape in plan view and having an upper surface 62 and a lower surface 63. The wiring substrate 61 with an optical waveguide includes a substrate body 69, an optical waveguide 81, and the like. As shown in FIG. 4, the board body 69 is a multilayer wiring board constituted by a resin insulating layer 64 and a metal conductor layer 65. The resin insulating layer 64 is, for example, about 30 μm thick, and is made of a resin-resin composite material obtained by impregnating continuous porous PTFE with an epoxy resin, or a glass cloth base epoxy resin having a thickness of about 100 μm.

  As shown in FIG. 4, through holes 66 for internal conduction penetrating in the thickness direction of the resin insulating layer 64 are formed at a plurality of locations in the resin insulating layer 64. These through-hole portions 66 serve to electrically connect metal conductor layers 65 of different layers. Further, a pad 67 serving as a connection terminal is arranged at a position where the upper end surface of each through-hole portion 66 is located on the upper surface 62 of the wiring substrate 61 with an optical waveguide.

  As shown in FIGS. 1 to 4, the optical waveguide 81 is formed in a mounting recess 68 provided on the upper surface 62 side of the wiring substrate 61 with an optical waveguide. It is exposed to the upper surface 62 and is flush with the upper surface 62. The optical waveguide 81 has a core 83 and a clad 84 surrounding it. It should be noted that the core 83 substantially becomes an optical path through which the optical signal propagates. In the case of this embodiment, the core 83 and the clad 84 are formed of transparent polymer materials having different refractive indexes, specifically, PMMA (polymethyl methacrylate) having different refractive indexes. The number of cores 83 serving as optical paths is 12, which are linear and are formed to extend in parallel to each other.

  A V-shaped groove 85 opened at the lower surface of the optical waveguide 81 is formed at a predetermined location in the optical waveguide 81. The tip of the V-shaped groove 85 extends to a certain depth of the core 83. The inner surface of the V-shaped groove 85 is an inclined surface having an angle of about 45 ° with respect to the upper surface 62 of the wiring substrate 61 with an optical waveguide, and a thin film 87 made of a metal capable of totally reflecting light is formed on the inclined surface. Vapor deposited. As a result, an optical path conversion mirror (optical path conversion unit) that reflects light at an angle of 90 ° is configured.

  As shown in FIGS. 1 to 4, the opto-electric hybrid package 2 includes a wiring board 10. The wiring board 10 has a main surface 12 and a back surface 13 located on the opposite side, and has a square plate shape of 50.0 mm long × 50.0 mm wide × 1.0 mm thick. The wiring board 10 includes a substantially rectangular plate-shaped core substrate 14 (core portion) made of glass epoxy, and a first buildup on a core main surface 15 (upper surface in FIG. 4) that is a surface layer of the core substrate 14. This is a build-up multilayer wiring board having a layer 31 and having a second build-up layer 32 on the core back surface 16 (the lower surface in FIG. 4) that is also a surface layer of the core substrate 14.

  As shown in FIG. 4, through-hole conductors 17 that penetrate the core main surface 15 and the core back surface 16 are formed at a plurality of locations on the core substrate 14. These through-hole conductors 17 connect and conduct the core main surface 15 side and the core back surface 16 side of the core substrate 14. Note that the inside of the through-hole conductor 17 is filled with a closing body 18 such as an epoxy resin. A lid-like conductor 19 made of a copper plating layer is formed in the opening of the through-hole conductor 17, and as a result, the through-hole conductor 17 is closed. A wiring pattern 20 made of a copper plating layer is formed at a location where the through-hole conductor 17 does not exist on the core main surface 15 and the core back surface 16 of the core substrate 14.

  The first buildup layer 31 has a structure in which five resin insulation layers 33 made of thermosetting resin (epoxy resin) and metal conductor layers 42 made of copper are alternately laminated. In addition, inner layer connection via conductors 43 connected to the metal conductor layer 42 are formed at a plurality of locations in each resin insulating layer 33. Further, the surface of the fifth resin insulating layer 33 is almost entirely covered with a solder resist 37.

  As shown in FIG. 3, the main surface 12 side of the wiring board 10 is covered with a metal lid 11. 1 to 4, main surface side recesses 50 and 51 are formed on the main surface 12 side of the wiring substrate 10. The main surface side concave portion 50 is disposed in a region that becomes the central portion of the substrate on the main surface 12 side of the wiring substrate 10 and has a substantially rectangular shape in plan view. On the other hand, the main surface side recess 51 is disposed in a region closer to the outer periphery of the substrate than the main surface side recess 50 on the main surface 12 side of the wiring substrate 10 and has a substantially rectangular shape in plan view. In addition, a plurality of CPU connection terminals 58 each having a substantially rectangular shape are formed on the bottom surface of the main surface side recess 50, and each of the CPU connection terminals 58 having a substantially rectangular shape in plan view is formed on the bottom surface of the main surface side recess 51. A plurality of driver IC connection terminals 57 are formed. Each CPU connection terminal 58 and each driver IC connection terminal 57 are electrically connected to each other. A region to which each CPU connection terminal 58 belongs on the main surface 12 side of the wiring substrate 10 (a bottom surface of the main surface side recess 50), or a region to which each driver IC connection terminal 57 belongs on the main surface 12 side of the wiring substrate 10. The (bottom surface of the main surface side recess 51) becomes the semiconductor integrated circuit element mounting region 23. The bottom surfaces of the main surface side recesses 50 and 51 are part of the surface of the first resin insulation layer 33, respectively. Solder balls 45 are disposed on the surfaces of the CPU connection terminal 58 and the driver IC connection terminal 57, respectively.

  As shown in FIGS. 1 and 3, each solder ball 45 disposed on the surface of the CPU connection terminal 58 belonging to the semiconductor integrated circuit element mounting region 23 is provided with an IC chip 21 (semiconductor integrated circuit element). CPU) is joined. The IC chip 21 having a function as an MPU has a rectangular flat plate shape of 10.0 mm long × 7.5 mm wide × 0.7 mm thick. Circuit elements (not shown) are formed on the lower surface layer of the IC chip 21. A plurality of element-side terminals (not shown) are provided in a grid pattern on the lower surface side of the IC chip 21.

  As shown in FIGS. 1 to 4, each solder ball 45 disposed on the surface of the driver IC connection terminal 57 belonging to the semiconductor integrated circuit element mounting region 23 is provided with a driver IC 22 which is a semiconductor integrated circuit element. Are joined. The driver IC 22 of the present embodiment has a substantially rectangular flat plate shape of 3.5 mm long × 2.5 mm wide. Circuit elements (not shown) are formed on the lower surface layer of the driver IC 22. Further, the plurality of terminals 28 of the driver IC 22 are joined to the solder balls 45, respectively.

  As shown in FIG. 3 and FIG. 4 and the like, a plurality of portions each having a substantially rectangular shape in plan view are formed on the surface of the first resin insulating layer 33 and on the bottom surface of the main surface side recess 51. The optical element connecting terminal 55 (optical element mounting portion) is formed. Solder balls 56 (optical element mounting portions) are disposed on the surface of each optical element connection terminal 55.

  As shown in FIG. 1 to FIG. 4, the VCSEL 24, which is a kind of optical element (light emitting element), is disposed below the light emitting surface (described above) on the solder ball 56 disposed on the surface of the optical element connecting terminal 55. It is mounted by flip-chip bonding in a state directed toward the optical waveguide 81 side. The VCSEL 24 of this embodiment has a substantially rectangular flat plate shape of 3.0 mm long × 0.25 mm wide × 0.2 mm thick. The VCSEL 24 has a plurality of (here, 12) light emitting units 25 arranged in a line along the longitudinal direction of the VCSEL 24 in the light emitting surface. These light emitting portions 25 emit laser light (optical signals) having a predetermined wavelength in a direction orthogonal to the main surface 12 of the wiring board 10 (that is, in the downward direction in FIGS. 2 to 4). Yes. The plurality of terminals 29 included in the VCSEL 24 are joined to the solder balls 56, respectively. The VCSEL 24 is electrically connected to the driver IC 22 via the optical element connecting terminal 55 and the driver IC connecting terminal 57 constituting the wiring board 10, and is driven by the driver IC 22. Yes.

  As shown in FIG. 4, the second buildup layer 32 has substantially the same structure as the first buildup layer 31 described above. That is, the second buildup layer 32 has a structure in which five resin insulation layers 34 made of thermosetting resin (epoxy resin) and metal conductor layers 42 are alternately laminated. In addition, inner layer connection via conductors 47 connected to the metal conductor layer 42 and the like are formed at a plurality of locations in each resin insulating layer 34.

  As shown in FIGS. 2 to 4, a back surface side recess 52 is formed on the back surface 13 side of the wiring substrate 10, and a protrusion 53 is formed at a location where the back surface side recess 52 is not formed on the back surface 13 side. ing. BGA pads 48, which are solder ball joints, are formed in a lattice pattern at a plurality of locations on the bottom surface of the back-side recess 52. That is, the BGA pad 48 is located on the back surface 13 side of the wiring board 10. Further, the protruding portion 53 protrudes from the back surface 13 side of the wiring substrate 10 toward the wiring substrate 61 with an optical waveguide. And the protrusion part 53 is the state protruded to the wiring board 61 with an optical waveguide rather than the pad 48 for BGA. Note that the bottom surface of the back surface side recess 52 is a part of the surface of the first resin insulating layer 34. Further, the lower surface of the first resin insulating layer 34 is almost entirely covered with a solder resist 38. An opening 39 for exposing the BGA pad 48 is formed at a predetermined position of the solder resist 38. A plurality of solder balls 49 that can be electrically connected to the wiring substrate 61 with an optical waveguide are joined on the surface of the BGA pad 48. Each solder ball 49 is soldered to the pad 67 of the wiring substrate 61 with an optical waveguide, whereby the wiring substrate 10 is mounted on the wiring substrate 61 with an optical waveguide.

  As shown in FIGS. 2 to 4, the wiring substrate 10 has a plurality of optical waveguide structure holes 70. The optical element connection terminal 55 is disposed in the vicinity of the opening on the main surface 12 side of each optical waveguide structure hole 70. Each optical waveguide structure hole 70 has a circular cross section and an equal cross section, and penetrates the main surface 12 of the wiring substrate 10 and the front end surface 54 of the protrusion 53 (the back surface 13 of the wiring substrate 10). In the present embodiment, the diameter of each optical waveguide structure hole 70 is set to about 0.05 mm.

  In each optical waveguide structure hole 70, an optical waveguide structure 71 provided in the opto-electric hybrid package 2 is formed. Each optical waveguide structure 71 has a core 72 and a clad 73 surrounding it. The core 72 substantially becomes an optical path through which the optical signal propagates. In the case of this embodiment, the core 72 and the clad 73 are formed of transparent polymer materials having different refractive indexes, specifically, PMMA (polymethyl methacrylate) having different refractive indexes. The clad 73 is formed by filling the optical waveguide structure hole 70 with a liquid clad material and solidifying it. The core 72 is formed by filling a liquid core material into a core hole formed by removing a part of the clad 73 and solidifying it. The number of cores 72 serving as an optical path is 12 as the number of the light emitting portions 25 of the VCSEL 24, and they are formed so as to extend linearly and in parallel to each other.

  As a result, the VCSEL 24 and the optical waveguide structure 71 are fixed while being aligned in the planar direction. Here, the “aligned state in the plane direction” means a state in which the optical waveguide structure portion 71 is directly below each light emitting portion 25 and the optical axes of each core 72 and each light emitting portion 25 are aligned.

  As shown in FIG. 2, the step A1 between the surface of the BGA pad 48 and the front end surface 54 of the protrusion 53 (the back surface 13 of the wiring board 10) is more than half of the maximum diameter A2 (diameter) of the solder ball 49. The solder ball 49 has a maximum diameter A2 or less. In the present embodiment, the maximum diameter A2 of the solder ball 49 is set to 500 μm, and the step A1 is set to 475 μm. The space A3 (gap) generated between the tip surface 54 of the protrusion 53 and the upper surface of the optical waveguide 81 (the upper surface 62 of the wiring substrate 61 with an optical waveguide) is preferably 0 μm or more and 200 μm or less. In the embodiment, it is 25 μm. The distance (light transmission distance) between the end portion on the back surface side of the optical waveguide structure 71 (tip surface 54 of the protruding portion 53) and the core 83 of the optical waveguide 81 is preferably 200 μm or less. In the embodiment, it is set to 100 μm.

  In addition, the main surface side recessed part 51 is also formed in the main surface 12 of the wiring board 10 with which the opto-electric hybrid packages 3 and 4 on the right side and the lower side in FIG. A plurality of receiver IC connection terminals (not shown) are formed on the bottom surface of the main surface side recess 51, and solder balls 45 are formed on the surface of each receiver IC connection terminal. Each solder ball 45 is joined to a receiver IC 26 which is a semiconductor integrated circuit element. The receiver IC 26 of the present embodiment has a substantially rectangular flat plate shape of 3.5 mm long × 2.5 mm wide. Circuit elements (not shown) are formed on the lower surface layer of the receiver IC 26. A plurality of terminals (not shown) of the receiver IC 26 are joined to the solder balls 45, respectively.

  A plurality of optical element connection terminals 55 are also formed on the main surface 12 of the wiring board 10 included in the opto-electric hybrid packages 3 and 4. On the surface of each optical element connection terminal 55, a photodiode 27, which is a kind of optical element (light receiving element), is bonded with the light receiving surface facing downward (on the optical waveguide 81 side). The photodiode 27 of the present embodiment has a substantially rectangular flat plate shape of 3.0 mm long × 0.25 mm wide × 0.2 mm thick. The photodiode 27 has a plurality of (here, 12) light receiving portions (not shown) arranged in a line along the longitudinal direction of the photodiode 27 in the light receiving surface. Therefore, these light receiving portions are configured to easily receive laser light (optical signal) from the optical waveguide 81 side toward the photodiode 27 side. Note that the photodiode 27 is electrically connected to the receiver IC 26 and is driven by the receiver IC 26.

  A general operation of the opto-electric hybrid module 1 configured as described above will be briefly described.

  The VCSEL 24 and the photodiode 27 become operable by supplying power through the metal conductor layer 65 of the wiring substrate 61 with an optical waveguide, the metal conductor layer 42 of the wiring substrate 10, or the like. When an electrical signal is output from the driver IC 22 on the wiring board 10 to the VCSEL 24, the VCSEL 24 converts the input electrical signal into an optical signal (laser light), and then converts the optical signal to one end of the core 83 (right end in FIG. 2). The light is emitted from the light emitting unit 25 toward the optical path changing mirror located at (3). The laser light emitted from the light emitting unit 25 travels through the core 72 of the optical waveguide structure 71, enters from the upper surface side of the optical waveguide 81, and enters the optical path changing mirror of the core 83. The laser light incident on the optical path conversion mirror changes its traveling direction by 90 °, passes through the core 83, and enters the optical path conversion mirror on the other end side (the left end side in FIG. 2) of the core 83. Then, the laser light incident on the optical path conversion mirror on the other end side changes its traveling direction by 90 ° and is emitted from the upper surface side of the optical waveguide 81. Further, the laser light travels through the core 72 of the optical waveguide structure 71 and then enters the light receiving portion of the photodiode 27. The photodiode 27 converts the received laser light into an electrical signal and outputs the converted electrical signal to the receiver IC 26.

  Next, a manufacturing method of the opto-electric hybrid module 1 having the above configuration will be described.

  First, the wiring board 10 is prepared by a conventionally known method and prepared in advance. The wiring board 10 is manufactured as follows. First, a copper clad laminate (not shown) in which a copper foil is pasted on both sides of a base 50 mm long × 50 mm wide × 0.6 mm thick is prepared. Then, laser drilling is performed using a YAG laser or a carbon dioxide gas laser, and a through hole penetrating the copper-clad laminate is formed in advance at a predetermined position. Next, after the through-hole conductor 17 is formed by performing electroless copper plating and electrolytic copper plating according to a conventionally known method, the closing body 18 is filled in the through-hole conductor 17. Further, copper plating is performed to form the lid-like conductor 19, and the copper foil on both sides of the copper-clad laminate is further etched to pattern the wiring pattern 20. Specifically, after electroless copper plating, exposure and development are performed to form a predetermined pattern of plating resist. In this state, after electrolytic copper plating is performed using the electroless copper plating layer as a common electrode, first, the resist is dissolved and removed, and further unnecessary electroless copper plating layer is removed by etching. As a result, the core substrate 14 is obtained.

  Next, a photosensitive epoxy resin is applied to the core main surface 15 and the core back surface 16 of the core substrate 14, and exposure and development are performed, so that blind holes are formed at positions where the inner layer connection via conductors 43 and 47 are to be formed. The first resin insulation layers 33 and 34 are formed. Further, electrolytic copper plating is performed according to a conventionally known method (for example, semi-additive method) to form inner layer connection via conductors 43 and 47 inside the blind holes, and a metal conductor layer 42 is formed on the resin insulating layers 33 and 34. Form.

  Next, a photosensitive epoxy resin is deposited on the first resin insulation layers 33 and 34, and exposure and development are performed, whereby blind holes are formed at positions where the inner layer connection via conductors 43 and 47 are to be formed. Second resin insulation layers 33 and 34 are formed. Next, electrolytic copper plating is performed according to a conventionally known method to form inner layer connection via conductors 43 and 47 inside the blind holes, and a metal conductor layer 42 is formed on the second resin insulation layers 33 and 34. To do.

  Further, a photosensitive epoxy resin is deposited on the second resin insulation layers 33 and 34, and exposure and development are performed, whereby blind holes are formed at positions where the inner layer connection via conductors 43 and 47 are to be formed. Three resin insulation layers 33 and 34 are formed. Next, electrolytic copper plating is performed in accordance with a conventionally known method to form inner layer connection via conductors 43 and 47 inside the blind holes and to form a metal conductor layer 42 on the third resin insulation layers 33 and 34. To do.

  Next, a photosensitive epoxy resin is applied onto the third resin insulation layers 33 and 34, and exposure and development are performed, so that blind holes are formed at positions where the inner layer connection via conductors 43 and 47 are to be formed. Fourth resin insulation layers 33 and 34 are formed. Next, electrolytic copper plating is performed according to a conventionally known method to form inner layer connection via conductors 43 and 47 inside the blind holes, and a metal conductor layer 42 is formed on the fourth resin insulation layers 33 and 34. To do.

  Furthermore, a photosensitive epoxy resin is deposited on the resin insulation layers 33 and 34 of the fourth layer, and exposure and development are performed, whereby blind holes are formed at positions where the inner layer connection via conductors 43 and 47 are to be formed. Five resin insulation layers 33 and 34 are formed. Next, electrolytic copper plating is performed in accordance with a conventionally known technique to form inner layer connection via conductors 43 and 47 inside the blind hole. At this point, the first buildup layer 31 and the second buildup layer 32 are completed (see FIG. 5).

  Next, milling using the router 91 is performed on the second to fifth resin insulation layers 33 constituting the first buildup layer 31 to form the main surface side recesses 50 and 51 (FIG. 6). reference). Similarly, milling processing using the router 91 is performed on the second to fifth resin insulating layers 34 constituting the second buildup layer 32 to form the back surface side recess 52. Further, a CPU connection terminal 58 is formed on the bottom surface of the main surface side recess 50, and a driver IC connection terminal 57 (or receiver IC connection terminal) and an optical element connection terminal are formed on the bottom surface of the main surface side recess 51. 55 is formed (see FIG. 7). Similarly, a BGA pad 48 is formed on the bottom surface of the back surface side recess 52.

  Thereafter, a solder resist 37 is formed on the fifth resin insulating layer 33 and a solder resist 38 is formed on the first resin insulating layer 34. Next, exposure and development are performed with a predetermined mask placed, and the opening 39 is patterned in the solder resist 38. As a result, the desired wiring board 10 having the build-up layers 31 and 32 on both sides is completed.

  Next, the hole 70 for optical waveguide structures is formed in the wiring board 10 by performing the precision drilling process using the precision drill 111 with respect to the wiring board 10 (refer FIG. 8). Further, finishing is performed by a well-known method to finely adjust the hole diameter of the optical waveguide structure hole 70 to 0.05 mm. Specifically, the accuracy required for processing at this time is ± 0.003 mm.

  Next, a clad 73 in the optical waveguide structure 71 and a core 72 in the optical waveguide structure 71 are formed in the optical waveguide structure hole 70 (see FIG. 9). In the present embodiment, the clad 73 is formed by filling a liquid clad material into the optical waveguide structure hole 70 and solidifying it. A core hole penetrating the main surface 12 and the back surface 13 is formed by removing a part of the clad 73 by performing a precision drill using a precision drill. The core hole may be formed by removing a part of the clad 73 by performing laser processing using a YAG laser or a carbon dioxide gas laser. Next, the core 72 is formed by filling the core hole with a liquid core material and solidifying it. As a result, the optical waveguide structure 71 is formed.

  If the above method is adopted, when the clad 73 is precision drilled, the inner wall surface of the core hole may be roughened. Therefore, the optical waveguide structure 71 may be formed in the optical waveguide structure hole 70 subjected to precision drilling using the following method. Specifically, first, a clad 73 having a core hole is formed by applying a liquid clad material to the inner wall surface of the optical waveguide structure hole 70 and solidifying it. Next, the core 72 is formed by printing and filling a liquid core material into the core hole to be solidified. According to this method, the inner wall surface of the core hole can be smoothed, and the inner wall surface of the core hole can be used as a reflecting surface. Loss and deterioration can be reduced.

  Also, a substrate body 69 constituting the optical waveguide-equipped wiring substrate 61 is prepared and prepared by a conventionally known method. As a specific example, a copper-clad laminate is used as a starting material, and copper foil etching, electroless copper plating, or the like is performed to form a resin insulating layer 64 having a metal conductor layer 65 and a through-hole portion 66. Next, a resin insulating layer 64 is further laminated on the surface layer of the resin insulating layer 64, and pads 67 and mounting recesses 68 are formed on the upper surface 62 of the uppermost resin insulating layer 64. Further, according to a conventionally known method, the clad 84 and the core 83 are sequentially laminated on the bottom surface of the mounting recess 68 to form the optical waveguide 81.

  Further, in the completed wiring board 10, solder balls 45 are formed on the CPU connection terminal 58 and the driver IC connection terminal 57 (or on the receiver IC connection terminal), and the BGA pad 48. Solder balls 49 are formed thereon (see FIG. 10). More specifically, solder balls 45 are formed by applying a solder paste to the CPU connection terminals 58 and the driver IC connection terminals 57 (or receiver IC connection terminals) and reflowing, and solder is applied to the BGA pads 48. Solder balls 49 are formed by applying paste and reflowing.

  Next, the IC chip 21 is mounted on the semiconductor integrated circuit element mounting region 23 of the wiring board 10. At this time, reflow is performed by aligning the CPU connection terminal 58 and the element side terminal of the IC chip 21. As a result, the CPU connection terminal 58 and the element side terminal are joined together, and the wiring board 10 and the IC chip 21 are electrically connected.

  Further, in the opto-electric hybrid package 2 at the center in FIG. 1, the driver IC 22 and the VCSEL 24 are mounted on the main surface 12 side of the wiring board 10 (see FIG. 10). Further, in the opto-electric hybrid packages 3 and 4 on the right side and the lower side in FIG. 1, the receiver IC 26 and the photodiode 27 are mounted on the main surface 12 side of the wiring board 10. More specifically, reflow is performed with the driver IC 22 pressed against the solder ball 45, and the terminal 28 of the driver IC 22 is soldered to the solder ball 45. On the other hand, the receiver IC 26 is also mounted on the main surface 12 side of the wiring board 10 through the same process as the driver IC 22. Further, reflow is performed in a state where the VCSEL 24 is pressed against the solder ball 56, and the terminals 29 of the VCSEL 24 are soldered to the solder ball 56. At this time, the optical axis alignment between the light emitting part 25 of the VCSEL 24 (or the light receiving part of the photodiode 27) and the core 72 of the optical waveguide structure 71 is performed by the self-alignment action when the solder balls 56 are reflowed. On the other hand, the photodiode 27 is also mounted on the main surface 12 side of the wiring substrate 10 through the same process as the VCSEL 24. As a result, desired opto-electric hybrid packages with optical elements 2, 3, and 4 are completed.

  In addition, the solder balls 49 of the opto-electric hybrid packages 2, 3 and 4 are reflowed in a state where the solder balls 49 are in close contact with the upper surface 62 of the wiring substrate 61 with an optical waveguide. At this time, the optical axis alignment between the core 72 of the optical waveguide structure 71 and the core 83 of the optical waveguide 81 is performed by a self-alignment action when the solder balls 49 are reflowed. As a result, the solder balls 49 and the pads 67 of the wiring board 61 with the optical waveguide are joined, and the opto-electric hybrid packages 2, 3 and 4 are soldered to the wiring board 61 with the optical waveguide. As described above, the opto-electric hybrid module 1 of this embodiment shown in FIG. 1 is completed.

  Therefore, according to the present embodiment, the following effects can be obtained.

  (1) According to the opto-electric hybrid module 1 of the present embodiment, the step A1 between the surface of the BGA pad 48 and the tip surface 54 of the projecting portion 53 is the maximum of the solder ball 49 joined on the BGA pad 48. The size is more than half of the diameter A2. For this reason, when the opto-electric hybrid packages 2, 3, and 4 are mounted on the wiring substrate 61 with the optical waveguide, the space A3 generated between the tip surface 54 and the optical waveguide 81 is reduced. Accordingly, the optical path connecting the optical waveguide structure 71 and the optical waveguide 81 is shortened, so that loss and degradation of the optical signal can be reliably reduced when the optical signal propagates through the space A3. In particular, when the structure of this embodiment is employed when there are many optical waveguide structures 71, that is, when there are many optical elements, the optical paths connected to the optical elements can be shortened. Loss and deterioration are more effectively reduced.

  (2) In this embodiment, the space A3 is reduced to reduce the loss and deterioration of the optical signal. Therefore, in order to reduce the loss and deterioration of the optical signal, a lens for allowing laser light to pass from the light emitting portion 25 of the VCSEL 24 toward the core 83 of the optical waveguide 81, or from the core 83 toward the light receiving portion of the photodiode 27. Thus, it is not necessary to provide a lens for allowing the laser beam to pass through on the front end surface 54 of the protruding portion 53. Therefore, the number of parts of the opto-electric hybrid package 2, 3, 4 is reduced, and the number of man-hours at the time of manufacture is reduced.

  (3) The VCSEL 24 of the present embodiment is configured to emit an optical signal in a direction orthogonal to the main surface 12 of the wiring board 10 from the light emitting unit 25 (that is, downward in FIGS. 2 to 4). The main surface 12 of the wiring board 10 is mounted. In addition, the photodiode 27 of the present embodiment has a configuration in which the light receiving portion easily receives an optical signal from the optical waveguide 81 side toward the photodiode 27 side, and is similarly mounted on the main surface 12 of the wiring board 10. Therefore, since the VCSEL 24 and the photodiode 27 can be mounted by a conventional technique such as flip chip bonding, the opto-electric hybrid module 1 can be manufactured at low cost.

(4) For example, if the optical waveguide structure 71 is exposed to the outside, the light is likely to be scattered, so that the quality of the optical signal is deteriorated. On the other hand, the optical waveguide structure 71 of this embodiment is formed in the optical waveguide structure hole 70 penetrating the wiring substrate 10. As a result, the optical signal propagates through the optical waveguide structure 71 while being reflected by the inner wall surface of the optical waveguide structure hole 70, so that the optical signal is transmitted without loss or scattering. Therefore, it is possible to prevent the quality deterioration of the optical signal.
[Second Embodiment]

  Hereinafter, the opto-electric hybrid module 1 according to the second embodiment embodying the present invention will be described in detail with reference to FIGS. Here, the points different from those of the first embodiment will be mainly described, and common points will be simply denoted by the same member numbers.

  As shown in FIG. 12, the opto-electric hybrid module 1 of the present embodiment is different from the first embodiment in the structure of the wiring board. The wiring substrate 100 of this embodiment is a ceramic multilayer wiring substrate configured by laminating a plurality of ceramic layers 101 at once. Each ceramic layer 101 has an upper surface 102 and a lower surface 103. An upper surface side wiring layer 104 that extends in the substrate plane direction is formed on the upper surface 102, and a lower surface side wiring layer 105 that also extends in the substrate plane direction is formed on the lower surface 103. The ceramic layer 101 is mainly composed of a ceramic sintered body obtained by firing a green sheet 107 (see FIG. 11) mainly composed of alumina, and the upper surface side wiring layer 104 and the lower surface side wiring layer 105 are formed of tungsten. . The ceramic layer 101 is provided with a plurality of via conductors 106 that penetrate the upper surface 102 and the lower surface 103. The upper end surface of each via conductor 106 can be electrically connected to the upper surface side wiring layer 104, and the lower end surface of each via conductor 106 can be electrically connected to the lower surface side wiring layer 105. Yes.

  Next, a procedure for manufacturing the wiring board 100 will be described.

  First, a raw material slurry is prepared by uniformly mixing and kneading alumina powder, an organic binder solvent, a plasticizer, and the like, and using this raw material slurry, a sheet is formed by a doctor blade device, and a green sheet 107 (ceramic) having a predetermined thickness is formed. A green body) is formed for a plurality of layers. Next, a predetermined portion of each green sheet 107 is punched to form a through hole 74 to be an optical waveguide structure hole 70 and a via hole for the via conductor 106. Since it is still unsintered at this stage, drilling can be performed relatively easily and at low cost. Thereafter, the via paste is filled with the metal paste 108 and the metal paste 109 is printed on the surface of the green sheet 107.

  Next, a plurality of green sheets 107 are stacked and arranged, and are pressed and integrated using a press device, thereby producing a ceramic laminate having the optical waveguide structure hole 70. At this time, the part which becomes the protrusion part 53 in a ceramic laminated body is also produced simultaneously. Next, after performing a drying process, a degreasing process, etc. according to a well-known method, a baking process is further performed at the heating temperature (1650 degreeC-1950 degreeC) which an alumina can sinter. Thereby, the ceramic laminate is sintered to form the wiring substrate 100 (see FIG. 12). At this point, the ceramic hardens and shrinks. Also, the metal paste 108 filled in the via hole becomes the via conductor 106, and the metal paste 109 printed on the surface of the green sheet 107 becomes the upper surface side wiring layer 104 and the lower surface side wiring layer 105.

Therefore, according to the present embodiment, the wiring board 100 constituting the opto-electric hybrid package 2, 3, 4 is a ceramic multilayer wiring board. Since this ceramic multilayer wiring board has higher thermal conductivity than other wiring boards such as a resin board, the wiring board 100 is hardly deformed by thermal expansion. Therefore, it is possible to prevent a positional shift between the optical waveguide structure 71 and the optical waveguide 81 due to thermal expansion. Further, since the generated heat is efficiently dissipated from the wiring substrate 100, it is possible to avoid the shift of the emission wavelength due to the deterioration of the heat dissipation property, and to realize the wiring substrate 100 excellent in operational stability and reliability. it can.
[Third Embodiment]

  Hereinafter, the opto-electric hybrid module 1 according to the third embodiment of the present invention will be described in detail with reference to FIGS. Here, the points different from those of the first embodiment will be mainly described, and common points will be simply denoted by the same member numbers.

  As shown in FIG. 15, the opto-electric hybrid module 1 of the present embodiment is different from the first embodiment in the structure of the wiring board. The wiring board 110 of the present embodiment is configured by molding a laminate (see FIG. 13) made of two resin insulating layers 111. The resin insulating layer 111 has an upper surface 112 and a lower surface 113. An upper surface side wiring layer 114 that extends in the substrate plane direction is formed on the upper surface 112, and a lower surface side wiring layer 115 that also extends in the substrate plane direction is formed on the lower surface 113. The resin insulating layer 111 is provided with a plurality of via conductors 116 that penetrate the upper surface 112 and the lower surface 113. The upper end surface of each via conductor 116 can be electrically connected to the upper surface side wiring layer 114, and the lower end surface of each via conductor 116 can be electrically connected to the lower surface side wiring layer 115. Yes.

  Next, a procedure for manufacturing the wiring board 110 will be described.

  First, the laminate shown in FIG. 13 is produced. Next, after placing the laminated body on the flat lower jig 117, the flat upper jig 118 is placed on the lower jig 117 and the laminated body (see FIG. 14). Thereby, the stacked body is sandwiched between the lower jig 117 and the upper jig 118. Further, a pressing force (4 MPa) is applied in the thickness direction (bonding direction) while heating to a temperature of 260 ° C. or higher under a vacuum of 20 Torr (≈2666 Pa) or less (vacuum hot press). Accordingly, the stacked body is pressed along the stacking direction and deformed along the pressing surfaces of the lower jig 117 and the upper jig 118. As a result, the wiring board 110 having the main surface side recess 51 and the back surface side recess 52 is formed.

  In addition, you may change embodiment of this invention as follows.

  -Although the opto-electric hybrid package 2, 3, and 4 of the said 1st Embodiment were comprised by the one wiring board 10, you may comprise by bonding a some wiring board. For example, as shown in FIG. 16, a first wiring board 124 to which solder balls 49 are bonded to the lower surface (BGA pad 48) and a second wiring board 125 that constitutes the protruding portion 53 are optically transparent. Alternatively, an opto-electric hybrid package 126 configured by bonding via 127 may be used.

  In the above embodiment, the step A1 between the surface of the BGA pad 48 and the tip surface 54 of the protruding portion 53 is set to a size equal to or smaller than the maximum diameter A2 of the solder ball 49. However, as shown in FIG. 17, the step A <b> 1 may be larger than the maximum diameter A <b> 2 of the solder ball 49. In this case, the optical waveguide 81 is built in the wiring substrate 61 with the optical waveguide, an opening 128 is formed in the wiring substrate 61 with the optical waveguide to expose the optical path conversion mirror, and the protruding portion 53 is inserted into the opening 128. . With such a configuration, since the optical path connecting the optical waveguide structure 71 and the optical waveguide 81 penetrating the tip surface 54 of the protrusion 53 is reliably shortened, loss and deterioration of the optical signal can be more reliably reduced. .

  As shown in FIG. 18, on the main surface 12 side of the wiring substrate 10, a first recess 131 that opens at the bottom surface of the main surface side recess 51 and a second recess 132 that opens at the bottom surface of the first recess 131. And may be formed. Then, the driver IC 22 is mounted on the semiconductor integrated circuit element mounting region 23 set on the bottom surface of the first recess 131, the IC chip 21 is mounted on the bottom surface of the main surface side recess 51, and the IC chip 21 is mounted on the driver IC 22. You may make it arrange | position just above. In addition, the VCSEL 24 may be mounted on the optical element mounting portion set on the bottom surface of the second recess 132, and the driver IC 22 may be disposed immediately above the VCSEL 24. Further, a heat sink 121 (heat dissipating means) may be surface bonded to the outer peripheral portion of the main surface 12 of the wiring board 10.

  In FIG. 18, the first recess 131 is opened at a substantially central portion of the bottom surface of the main surface side recess 51, and only the driver IC 22 is mounted on the bottom surface of the first recess 131. However, as shown in FIG. 19, the first recess 131 is opened at a position displaced in the substrate plane direction from the substantially central portion of the bottom surface of the main surface side recess 51, and the IC chip is formed on the bottom surface of the first recess 131. Both 21 and the driver IC 22 may be mounted.

  With such a configuration, the heat of the IC chip 21 and the driver IC 22 is released by the heat sink 121 and decreases, so that the adverse effect of the heat of the IC chip 21 and the driver IC 22 on the VCSEL 24 can be reduced more reliably, and the reliability of the VCSEL 24 Sex is further improved. Further, since the driver IC 22 is disposed in the first recess 131 and the VCSEL 24 is disposed in the second recess 132, even if the heat sink 121 is provided, the opto-electric hybrid package 2 is not easily thickened.

  Further, in FIG. 18 and FIG. 19, the second recess 132 is formed at a location on the main surface 12 side of the wiring substrate 10 and on the opposite side of the protrusion 53, and the area of the second recess 132 is It is smaller than the area of the front end surface 54. In this case, the thickness of the portion of the wiring board 10 where the protrusion 53 is located is likely to be thicker than the thickness of the portion of the wiring board 10 where the solder ball 49 (and the BGA pad 48) is located. . Therefore, even if the second recess 132 is formed at the above-described location, the strength reduction of the wiring board 10 is prevented.

  In the above embodiment, the mounting method of the IC chip 21, the driver IC 22, the receiver IC 26, the VCSEL 24, and the photodiode 27 may be changed as appropriate. For example, at least one of the IC chip 21, the driver IC 22 and the receiver IC 26 is connected to a bonding pad (not shown) formed on the main surface 12 or the back surface 13 of the wiring board 10 via a wire (not shown). May be.

  Next, the technical ideas grasped by the embodiment described above are listed below.

  (1) An opto-electric hybrid package that can be mounted on a substrate with an optical waveguide having an optical waveguide serving as an optical path through which an optical signal propagates, the wiring substrate having a main surface and a back surface located on the opposite side of the main surface; A plurality of solder balls that are bonded onto the solder ball bonding portion located on the back surface of the wiring substrate and connected to the substrate with the optical waveguide when mounted on the substrate with the optical waveguide, and among the light emitting portion and the light receiving portion An optical element mounted on an optical element mounting part located on the main surface of the wiring board, with at least one of the light emitting part and the light receiving part facing the optical waveguide side A protrusion formed on the wiring board so as to protrude from the back side of the wiring board toward the substrate with the optical waveguide, a core serving as an optical path through which an optical signal propagates, and a clad surrounding the core. An optical waveguide structure portion penetrating the main surface of the wiring board and the tip end surface of the protruding portion, and a step from the surface of the solder ball joint portion to the tip end surface of the protruding portion is the maximum diameter of the solder ball. The wiring board is a build-up multilayer wiring board having a build-up layer formed by alternately laminating resin insulating layers and metal conductor layers on the surface layer of the core part, and the optical element Electrically connected to a semiconductor integrated circuit element mounted on a semiconductor integrated circuit element mounting region set on the main surface side, and the optical element mounting portion and the semiconductor integrated circuit element mounting region are on the main surface side An opto-electric hybrid package characterized in that it is set on the bottom surface of a concave portion on the main surface side formed by performing router processing on the build-up layer located.

  (2) An opto-electric hybrid package that can be mounted on a substrate with an optical waveguide having an optical waveguide serving as an optical path through which an optical signal propagates, the wiring substrate having a main surface and a back surface located on the opposite side of the main surface; A plurality of solder balls that are bonded onto the solder ball bonding portion located on the back surface of the wiring substrate and connected to the substrate with the optical waveguide when mounted on the substrate with the optical waveguide, and among the light emitting portion and the light receiving portion An optical element mounted on an optical element mounting part located on the main surface of the wiring board, with at least one of the light emitting part and the light receiving part facing the optical waveguide side A protrusion formed on the wiring board so as to protrude from the back side of the wiring board toward the substrate with the optical waveguide, a core serving as an optical path through which an optical signal propagates, and a clad surrounding the core. An optical waveguide structure portion penetrating the main surface of the wiring board and the tip end surface of the protruding portion, and a step from the surface of the solder ball joint portion to the tip end surface of the protruding portion is the maximum diameter of the solder ball. An opto-electric hybrid package having a size of more than half, wherein the wiring board is formed by laminating a plurality of insulating layers at once.

  (3) An opto-electric hybrid package that can be mounted on a substrate with an optical waveguide provided with an optical waveguide serving as an optical path through which an optical signal propagates, the wiring substrate having a main surface and a back surface opposite to the main surface; A plurality of solder balls that are bonded onto the solder ball bonding portion located on the back surface of the wiring substrate and connected to the substrate with the optical waveguide when mounted on the substrate with the optical waveguide, and among the light emitting portion and the light receiving portion An optical element mounted on an optical element mounting part located on the main surface of the wiring board, with at least one of the light emitting part and the light receiving part facing the optical waveguide side A protrusion formed on the wiring board so as to protrude from the back side of the wiring board toward the substrate with the optical waveguide, a core serving as an optical path through which an optical signal propagates, and a clad surrounding the core. An optical waveguide structure portion penetrating the main surface of the wiring board and the tip end surface of the protruding portion, and a step from the surface of the solder ball joint portion to the tip end surface of the protruding portion is the maximum diameter of the solder ball. An opto-electric hybrid package having a size of half or more, wherein the wiring board is formed by applying a pressing force in a thickness direction while being sandwiched between an upper jig and a lower jig.

  (4) An opto-electric hybrid package that can be mounted on a substrate with an optical waveguide provided with an optical waveguide serving as an optical path through which an optical signal propagates, the wiring substrate having a main surface and a back surface located on the opposite side of the main surface; A plurality of solder balls that are bonded onto the solder ball bonding portion located on the back surface of the wiring substrate and connected to the substrate with the optical waveguide when mounted on the substrate with the optical waveguide, and among the light emitting portion and the light receiving portion An optical element mounted on an optical element mounting part located on the main surface of the wiring board, with at least one of the light emitting part and the light receiving part facing the optical waveguide side A protrusion formed on the wiring board so as to protrude from the back side of the wiring board toward the substrate with the optical waveguide, a core serving as an optical path through which an optical signal propagates, and a clad surrounding the core. An optical waveguide structure portion penetrating the main surface of the wiring board and the tip end surface of the protruding portion, and a step from the surface of the solder ball joint portion to the tip end surface of the protruding portion is the maximum diameter of the solder ball. An opto-electric hybrid package having a size of more than half and having no lens provided on a tip surface of the protrusion.

The schematic perspective view which shows the opto-electric hybrid module in 1st Embodiment. Similarly, the schematic sectional drawing which shows a photoelectric mixed module. Similarly, the schematic sectional drawing which shows a photoelectric mixed module. Similarly, principal part sectional drawing which shows a photoelectric mixed module. Similarly, explanatory drawing which shows the manufacturing method of an opto-electric hybrid module. Similarly, explanatory drawing which shows the manufacturing method of an opto-electric hybrid module. Similarly, explanatory drawing which shows the manufacturing method of an opto-electric hybrid module. Similarly, explanatory drawing which shows the manufacturing method of an opto-electric hybrid module. Similarly, explanatory drawing which shows the manufacturing method of an opto-electric hybrid module. Similarly, explanatory drawing which shows the manufacturing method of an opto-electric hybrid module. Explanatory drawing which shows the manufacturing method of the wiring board in 2nd Embodiment. Similarly, explanatory drawing which shows the manufacturing method of a wiring board. Explanatory drawing which shows the manufacturing method of the wiring board in 3rd Embodiment. Similarly, explanatory drawing which shows the manufacturing method of a wiring board. Similarly, the schematic plan view which shows a photoelectric mixed package. The schematic sectional drawing which shows the opto-electric hybrid module in other embodiment. The schematic sectional drawing which shows the opto-electric hybrid module in other embodiment. The schematic sectional drawing which shows the opto-electric hybrid module in other embodiment. The schematic sectional drawing which shows the opto-electric hybrid module in other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Opto-electric hybrid module 2, 3, 4, 126 ... Opto-electric hybrid package with optical element (opto-electric hybrid package)
DESCRIPTION OF SYMBOLS 10,100,110 ... Wiring board 12 ... Main surface 13 of a wiring substrate ... Back surface 14 of a wiring substrate ... Core substrate 15 as a core part ... Core main surface 16 as a surface layer of a core part ... Core back surface as a surface layer of a core part 21 ... IC chip as a semiconductor integrated circuit element 22 ... Driver IC as a semiconductor integrated circuit element
23 ... Semiconductor integrated circuit element mounting region 24 ... VCSEL as an optical element
25. Light emitting unit 26... Receiver IC as a semiconductor integrated circuit element
27 ... Photodiode 31 as optical element ... First buildup layer 32 as buildup layer ... Second buildup layer 33, 34 as buildup layer ... Resin insulating layer 42 ... Metal conductor layer 48 ... Solder ball joint BGA pad 49 ... solder ball 53 ... protruding portion 54 ... tip end surface 55 ... optical device connecting terminal 56 as optical device mounting portion ... solder ball 61 as optical device mounting portion ... as substrate with optical waveguide Wiring substrate with optical waveguide 62 ... Upper surface 71 as the surface of the substrate with optical waveguide ... Optical waveguide structure 72 ... Core 73 ... Cladding 81 ... Optical waveguide 121 ... Heat sink 128 as heat dissipation means ... Opening 131 ... First recess 132 ... second recess A1 ... step A2 ... maximum diameter

Claims (9)

An opto-electric hybrid package that can be mounted on a substrate with an optical waveguide provided with an optical waveguide serving as an optical path through which an optical signal propagates,
A wiring board having a main surface and a back surface located on the opposite side of the main surface;
A plurality of solder balls that are bonded onto the solder ball bonding portion located on the back surface of the wiring board and connected to the substrate with the optical waveguide when mounted on the substrate with the optical waveguide;
On an optical element mounting portion located on the main surface of the wiring board with at least one of a light emitting portion and a light receiving portion, with at least one of the light emitting portion and the light receiving portion facing the optical waveguide side An optical element mounted on
A protruding portion formed on the wiring board so as to protrude from the back side of the wiring board to the substrate side with the optical waveguide;
An optical waveguide structure having an optical path through which an optical signal propagates and a clad surrounding the core, and penetrating a main surface of the wiring board and a tip end surface of the protruding portion;
The opto-electric hybrid package is characterized in that a step from the surface of the solder ball joint portion to the tip end surface of the protruding portion has a size of half or more of the maximum diameter of the solder ball. The optical waveguide is exposed on the surface of the substrate with the optical waveguide;
2. The opto-electric hybrid package according to claim 1, wherein a step between the surface of the solder ball joint portion and the tip end surface of the protruding portion has a size equal to or smaller than the maximum diameter of the solder ball. The optical waveguide is built in the substrate with the optical waveguide,
An opening that exposes the optical path changing portion of the optical waveguide is formed in the substrate with the optical waveguide,
2. The step according to claim 1, wherein a step from a surface of the solder ball joint portion to a tip end surface of the protrusion is larger than a maximum diameter of the solder ball, and the protrusion can be inserted into the opening. The described opto-electric hybrid package.   4. The opto-electric hybrid package according to claim 1, wherein a maximum diameter of the solder ball is 500 μm or more. 5.   5. The opto-electric hybrid package according to claim 1, wherein a semiconductor integrated circuit element mounting region in which a semiconductor integrated circuit element can be mounted is set on the main surface side of the wiring board. 6. . A first recess opening on the main surface side of the wiring substrate is formed, the semiconductor integrated circuit element mounting region is set on the bottom surface of the first recess, and a second opening opening on the bottom surface of the first recess. A recess is formed, and the optical element mounting portion is set on the bottom surface of the second recess,
A semiconductor integrated circuit element mounted in the semiconductor integrated circuit element mounting region is disposed immediately above the optical element mounted on the optical element mounting portion;
6. The opto-electric hybrid package according to claim 5, wherein a heat radiating means for releasing heat of the semiconductor integrated circuit element to the outside is provided on the main surface of the wiring board. The second recess is formed at a location on the main surface side of the wiring board and on the opposite side of the protruding portion,
The photoelectric hybrid package according to claim 6, wherein an area of the second recess is smaller than an area of a front end surface of the protrusion. The wiring board is a build-up multilayer wiring board having a build-up layer formed by alternately laminating resin insulating layers and metal conductor layers on the surface layer of the core part,
The optical element is electrically connected to a semiconductor integrated circuit element mounted in a semiconductor integrated circuit element mounting region set on the main surface side through the build-up multilayer wiring board. The opto-electric hybrid package according to any one of claims 1 to 7. An opto-electric hybrid module comprising a substrate with an optical waveguide provided with an optical waveguide serving as an optical path through which an optical signal propagates, and an opto-electric hybrid package with an optical element mounted on the substrate with the optical waveguide,
The opto-electric hybrid package with an optical element is:
A wiring board having a main surface and a back surface located on the opposite side of the main surface;
A plurality of solder balls that are bonded onto the solder ball bonding portion located on the back surface of the wiring board and connected to the substrate with the optical waveguide when mounted on the substrate with the optical waveguide;
On an optical element mounting portion located on the main surface of the wiring board with at least one of a light emitting portion and a light receiving portion, with at least one of the light emitting portion and the light receiving portion facing the optical waveguide side An optical element mounted on
A protruding portion formed on the wiring board so as to protrude from the back side of the wiring board to the substrate side with the optical waveguide;
An optical waveguide structure having an optical path through which an optical signal propagates and a clad surrounding the core, and penetrating a main surface of the wiring board and a tip end surface of the protruding portion;
The opto-electric hybrid module is characterized in that a step between the surface of the solder ball joint portion and the tip end surface of the protruding portion is a size of half or more of the maximum diameter of the solder ball.

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