Optical and electrical transmission composite module

Abstract

Provided is an opto-electrical transmission composite module comprising: an opto-electrical hybrid substrate 5 configured to be optically and electrically connected to a photoelectric conversion unit 6, and including an optical waveguide 51 and an electric circuit substrate 52 successively toward one side in a thickness direction; a printed wiring board 4 electrically connected to the electric circuit substrate 52; a heat-dissipating layer 3; and a metal housing 2 storing the opto-electrical hybrid substrate 5, the printed wiring board 4, and the heat-dissipating layer 3, and having a first wall 21. The first wall 21, the heat-dissipating layer 3, a part of the printed wiring board 4, and the opto-electrical hybrid substrate 5 are arranged successively toward one side in the thickness direction. The heat-dissipating layer 3 is in contact with the first wall 21 and the printed wiring board 4.

Description

[Technical field]

[0001] The present invention relates to an optical and electrical transmission composite module. [Background technology]

[0002] Conventionally, there is known an optical module including an opto-electrical converter, an FPC (printed wiring board), an optical waveguide, a heat dissipation sheet, a printed circuit board, and a housing bottom wall in this order downward (see, for example, Patent Document 1 below). In the optical module of Patent Document 1, heat generated from the opto-electrical converter is mainly dissipated to the housing bottom wall via the heat dissipation sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-22129 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the heat generated by the photoelectric converter itself can damage the converter or affect its operability, the optical module is required to have higher heat dissipation properties. However, the optical module described in Patent Document 1 has a drawback in that it cannot satisfy the above requirements.

[0005] The present invention provides an optical / electrical transmission composite module capable of efficiently dissipating heat from an optical / electrical conversion section. [Means for solving the problem]

[0006] The present invention (1) includes an optical-electrical transmission composite module comprising: an optical-electrical hybrid board configured to be optically and electrically connected to an optical-electrical conversion unit, and including an optical waveguide and an electric circuit board, in that order, toward one side in a thickness direction; a printed wiring board electrically connected to the electric circuit board; a heat dissipation member; and a metal housing that houses the optical-electrical hybrid board, the printed wiring board, and a portion of the heat dissipation member, the housing including a first wall, wherein the first wall, the heat dissipation member, the printed wiring board, and the optical-electrical hybrid board are arranged in that order toward one side in the thickness direction, and the heat dissipation member is in contact with the first wall and the printed wiring board.

[0007] In this optical / electrical transmission composite module, the heat dissipation member is in contact with the first wall and the printed wiring board, so that heat generated in the optical / electrical conversion unit and reaching the heat dissipation member via the optical / electrical hybrid board and the printed wiring board can be efficiently dissipated to the first wall, allowing the optical / electrical conversion unit to operate efficiently and further allowing the heat of the optical / electrical conversion unit to be efficiently dissipated to the housing.

[0008] The present invention (2) includes the optical and electrical transmission composite module according to (1), in which the heat dissipation member has an Asker C hardness at 23° C. of 75 or less.

[0009] Since the heat dissipation member has an Asker C hardness of 75 or less, the heat dissipation member can be in close contact with the first wall and the printed wiring board, allowing the heat from the photoelectric conversion unit to be dissipated more efficiently by the housing.

[0010] The present invention (3) includes the optical and electrical transmission composite module according to (1) or (2), in which the heat dissipation member has a thermal conductivity in a thickness direction of 5 W / m·K or more.

[0011] In this optical / electrical transmission composite module, the thermal conductivity of the heat dissipation member is 5 W / m·K or more, so that the heat generated in the optical / electrical conversion section can be dissipated more efficiently.

[0012] The present invention (4) includes an optical-electrical transmission composite module according to any one of (1) to (3), further comprising a photoelectric conversion unit optically and electrically connected to the optical-electrical hybrid board, and a second heat dissipation member in contact with the photoelectric conversion unit, the housing further including a second wall arranged on the opposite side of the first wall in the thickness direction relative to the photoelectric conversion unit, and the second heat dissipation member in contact with the second wall.

[0013] This optical and electrical transmission composite module further includes a second heat dissipation member, and since the second heat dissipation member is in contact with the second wall, the heat generated in the photoelectric conversion unit can be dissipated more efficiently. In other words, the heat of the photoelectric conversion unit can be efficiently dissipated to the housing by both the heat dissipation member and the second heat dissipation member.

[0014] The present invention (5) includes the optical and electrical transmission composite module according to any one of (1) to (4), in which the second heat dissipation member has an Asker C hardness at 23° C. of 55 or less.

[0015] In this optical / electrical transmission composite module, the second heat dissipation member has an Asker C hardness of 55 or less, so that the second heat dissipation member can flexibly come into contact with the photoelectric conversion section, thereby suppressing damage to the photoelectric conversion section. Effect of the Invention

[0016] In the optical / electrical transmission composite module of the present invention, the heat generated in the optical / electrical conversion section can be dissipated more efficiently. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view of one embodiment of the optical and electrical transmission composite module of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of a modified example of the optical and electrical transmission composite module shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view of a modified example of the optical and electrical transmission composite module shown in FIG. [Figure 4]FIG. 4 is a cross-sectional view of a further modified example of the optical and electrical transmission composite module shown in FIG. [Diagram 5] FIG. 5 is a cross-sectional view of a further modified example of the optical and electrical transmission composite module shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view of the optical and electrical transmission composite module of Comparative Example 1. As shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] <One embodiment> An embodiment of the optical and electrical transmission composite module of the present invention will be described with reference to FIG.

[0019] The optical-electrical transmission composite module 1 has a predetermined thickness and a shape extending in the longitudinal direction. The optical-electrical transmission composite module 1 converts transmitted light into electricity and transmits it, and also converts transmitted electricity into light and transmits it. The optical-electrical transmission composite module 1 includes a housing 2, a heat dissipation layer 3 as an example of a heat dissipation member, a printed wiring board 4, an optical-electrical hybrid board 5, and an optical-electrical conversion unit 6.

[0020] The housing 2 has a generally flat box shape with a thickness length shorter than a width length (a direction perpendicular to the thickness direction and the longitudinal direction). The housing 2 integrally includes at least a first wall 21, a second wall 22, a connecting wall 23, a second connecting wall (not shown), and both side walls (not shown).

[0021] The first wall 21 has a flat plate shape extending along the longitudinal direction.

[0022] The second wall 22 is disposed opposite to and spaced from the first wall 21 on one side in the thickness direction of the first wall 21. The shape of the second wall 22 is the same as that of the first wall 21.

[0023] The connecting wall 23 connects one longitudinal end edge of the first wall 21 and one longitudinal end edge of the second wall 22 in the thickness direction. The connecting wall 23 has a flat plate shape extending in the width direction. A hole 7 into which one end of the printed wiring board 4 is inserted is formed in the middle part of the connecting wall 23 in the thickness direction. The hole 7 penetrates the connecting wall 23 in the longitudinal direction.

[0024] The second connecting wall (not shown) connects in the thickness direction the other longitudinal end edge of the first wall 21 and the other longitudinal end edge of the second wall 22. The second connecting wall extends in the width direction and has the same outer shape as that of the connecting wall 23.

[0025] The unillustrated side walls connect one widthwise end edge of the first wall 21 to one widthwise end edge of the second wall 22 in the thickness direction, and also connect the other widthwise end edge of the first wall 21 to the other widthwise end edge of the second wall 22 in the thickness direction. Furthermore, the unillustrated side walls are continuous with both widthwise end edges of the connecting wall 23 and both widthwise end edges of the unillustrated second connecting wall. Each of the unillustrated side walls extends in the longitudinal direction.

[0026] The housing 2 may be composed of two members: a first member 91 including the first wall 21, the connecting wall 23, the second connecting wall and portions of both side walls (portions on the other side in the thickness direction), and a second member 92 including the second wall 22 and the second connecting wall and remaining portions of both side walls (portions on one side in the thickness direction).

[0027] The housing 2 is made of metal. That is, the material of the housing 2 is a metal. Examples of metals include aluminum, copper, silver, zinc, nickel, chromium, titanium, tantalum, platinum, gold, and alloys thereof (brass, red brass, stainless steel, etc.). Preferably, the alloy is used, and more preferably, brass (an alloy of copper and zinc) is used.

[0028] The heat dissipation layer 3 has a predetermined thickness and a shape extending in the longitudinal direction. The heat dissipation layer 3 is accommodated in the housing 2. Specifically, the heat dissipation layer 3 is in contact with one surface in the thickness direction of the first wall 21. More specifically, the heat dissipation layer 3 is in contact with the entire one surface in the thickness direction of the first wall 21. The heat dissipation layer 3 includes, for example, a heat dissipation sheet, a heat dissipation grease, a heat dissipation plate, and the like. The material of the heat dissipation sheet includes, for example, a filler resin composition in which a filler is dispersed in a resin. Examples of the filler include alumina (aluminum oxide), boron nitride, zinc oxide, aluminum hydroxide, fused silica, magnesium oxide, aluminum nitride, and carbon fiber. Examples of the resin include, for example, silicone resin, epoxy resin, acrylic resin, and urethane resin, and preferably, epoxy resin. A curing agent may be added to the epoxy resin. The heat dissipation sheet includes, for example, one in which anisotropic fillers such as boron nitride and carbon fiber are oriented in the thickness direction in order to obtain high thermal conductivity. In the heat dissipation sheet, for example, the filler may be oriented in the thickness direction relative to the resin. The resin may include a thermosetting resin and be in the B stage or C stage. The resin may include a thermoplastic resin. The ratio of the filler and the resin is appropriately adjusted so as to obtain the Asker C hardness and thermal conductivity described later.

[0029] The Asker C hardness of the heat dissipation layer 3 is, for example, 75 or less, preferably 55 or less, more preferably 50 or less, even more preferably 40 or less, and for example, 1 or more. The Asker C hardness of the heat dissipation layer 3 is determined with an Asker hardness tester type C. When the Asker C hardness of the heat dissipation layer 3 is equal to or less than the above-mentioned upper limit, the heat dissipation layer 3 can be in close contact with the first wall 21 and the printed wiring board 4, and therefore the heat dissipation properties of the heat dissipation layer 3 can be improved.

[0030] The thermal conductivity of the heat dissipation layer 3 in the thickness direction is, for example, 1 W / m·K or more, preferably 5 W / m·K or more, more preferably 8 W / m·K or more, even more preferably 10 W / m·K or more, and is, for example, 200 W / m·K or less. The thermal conductivity of the heat dissipation layer 3 is determined by a steady method in accordance with ASTM-D5470 or a hot disk method in accordance with ISO-22007-2. When the thermal conductivity of the heat dissipation layer 3 is equal to or higher than the above-mentioned lower limit, the heat generated in the photoelectric conversion section 6 can be efficiently dissipated through the heat dissipation layer 3.

[0031] The heat dissipation layer 3 has a thickness of, for example, 100 μm or more, preferably 300 μm or more, and for example, 3000 μm or less, preferably 1000 μm or less.

[0032] The heat dissipation layer 3 may be a commercially available product.

[0033] The printed wiring board 4 has a predetermined thickness and a shape extending in the longitudinal direction. A portion (an example of a portion) of the printed wiring board 4 other than a protruding end portion 76 described later is housed in the housing 2.

[0034] Specifically, printed wiring board 4 has a generally rectangular outer shape in a plan view. Printed wiring board 4 is in contact with one surface in the thickness direction of heat dissipation layer 3. Printed wiring board 4 includes a support plate 71 and a conductor circuit 72.

[0035] The support plate 71 is parallel to the first wall 21 and has a shape extending in the longitudinal direction. The support plate 71 includes a protruding end 76. The protruding end 76 is provided at one longitudinal end of the support plate 71 and protrudes from the connecting wall 23 toward one longitudinal side. The material of the support plate 71 may be, for example, a hard material such as glass fiber reinforced epoxy resin. The Shore A hardness of the support plate 71 is, for example, 80 or more, or further 90 or more, and, for example, 200 or less. If the Shore A hardness of the support plate 71 is equal to or more than the above-mentioned lower limit, the strength of the protruding end 76 can be ensured and the photoelectric hybrid board 5 and the photoelectric conversion unit 6 can be reliably supported. The Shore A hardness is measured using a durometer (spring type rubber hardness tester) based on JIS K 6253-3 (2012).

[0036] Conductive circuit 72 is disposed on one surface in the thickness direction of support plate 71. Conductive circuit 72 includes a third terminal 73, a fourth terminal 74, and wiring (not shown).

[0037] The third terminal 73 is accommodated in the housing 2. The third terminal 73 is disposed on the other side in the longitudinal direction of the connecting wall 23 at a distance.

[0038] The fourth terminal 74 is disposed on one surface of the protruding end portion 76 in the thickness direction.

[0039] A wire (not shown) connects the third terminal 73 and the fourth terminal 74 together.

[0040] The material of the conductor circuit 72 may be, for example, a conductor such as copper.

[0041] The thickness of the printed wiring board 4 is, for example, 100 μm or more, preferably 500 μm or more, more preferably 1,000 μm or more, and is, for example, 10,000 μm or less.

[0042] The optical-electrical hybrid board 5 is housed in the housing 2 and mounted on the printed wiring board 4. The optical-electrical hybrid board 5 has a predetermined thickness and has a flat plate shape extending in the longitudinal direction. Specifically, the optical-electrical hybrid board 5 is in contact with one surface in the thickness direction of the printed wiring board 4. The optical-electrical hybrid board 5 includes an optical waveguide 51 and an electric circuit board 52 in this order toward one side in the thickness direction.

[0043] The optical waveguide 51 has a predetermined thickness and extends in the longitudinal direction. The optical waveguide 51 is in contact with one surface in the thickness direction of the printed wiring board 4. The optical waveguide 51 includes an undercladding layer 53, a core layer 54, and an overcladding layer 55.

[0044] The undercladding layer 53 has the same shape as the optical waveguide 51 in a plan view.

[0045] The core layer 54 is disposed in the widthwise center portion on the other thickness-wise surface of the undercladding layer 53. The width of the core layer 54 is narrower than the width of the undercladding layer 53 in a plan view.

[0046] The overclad layer 55 is disposed on the other thickness-wise surface of the underclad layer 53 so as to cover the core layer 54. In a plan view, the overclad layer 55 has the same shape as the outer shape of the underclad layer 53. Specifically, the overclad layer 55 is disposed on the other thickness-wise surface and both width-wise side surfaces of the core layer 54, and on both width-wise outer portions of the core layer 54 on the other thickness-wise surface of the underclad layer 53. The overclad layer 55 is in contact with one thickness-wise surface of the printed wiring board 4.

[0047] Furthermore, a mirror 16 is formed at one end of the core layer 54 in the longitudinal direction.

[0048] As the material of the optical waveguide 51, for example, a transparent material such as an epoxy resin can be mentioned. The refractive index of the core layer 54 is higher than the refractive index of the underclad layer 53 and the refractive index of the overclad layer 55. The thickness of the optical waveguide 51 is, for example, 20 μm or more and, for example, 200 μm or less.

[0049] The electric circuit board 52 has the same shape as the optoelectronic hybrid board 5 in a plan view. That is, the electric circuit board 52 has a predetermined thickness and has a flat plate shape extending in the longitudinal direction. It is disposed on one side in the thickness direction of the optical waveguide 51.

[0050] This electric circuit board 52 includes a metal support layer 56, a base insulating layer 57, a conductor layer 58, and a cover insulating layer (not shown).

[0051] The metal support layer 56 has the same outer shape as the optoelectronic hybrid board 5 in a plan view. The optical waveguide 51 is the outermost side part in the thickness direction of the optoelectronic hybrid board 5. Therefore, the metal support layer 56 is in contact with the underclad layer 53. Examples of the material of the metal support layer 56 include metals such as stainless steel. The thickness of the metal support layer 56 is, for example, 3 μm or more and, for example, 100 μm or less. Note that the metal support layer 56 includes a through hole 8 that penetrates in the thickness direction. When projected in the thickness direction, the through hole 8 overlaps with the mirror 16.

[0052] The base insulating layer 57 has the same outer shape as the metal support layer 56 in a plan view. The base insulating layer 57 is disposed on one side in the thickness direction of the metal support layer 56. Specifically, the base insulating layer 57 is in contact with all of one side in the thickness direction of the metal support layer 56. Further, the base insulating layer 57 closes one end edge in the thickness direction of the through hole 8. Examples of the material of the base insulating layer 57 include resins such as polyimide. The thickness of the base insulating layer 57 is, for example, 5 μm or more and, for example, 40 μm or less.

[0053] The conductor layer 58 is disposed on one side in the thickness direction of the base insulating layer 57. The conductor layer 58 includes a first terminal 27, a second terminal 28, and wiring (not shown).

[0054] The first terminal 27 is arranged corresponding to the photoelectric conversion unit 6 described below. A plurality of the first terminals 27 are arranged at intervals from each other.

[0055] The second terminal 28 is arranged at an interval on one side in the longitudinal direction of the first terminal 27. The second terminal 28 is electrically connected to the third terminal 73 via the wire 65.

[0056] Wiring (not shown) connects the first terminal 27 and the second terminal 28.

[0057] Examples of the material of the conductor layer 58 include conductors such as copper. The thickness of the conductor layer 58 is, for example, 3 μm or more and, for example, 20 μm or less.

[0058] A cover insulating layer (not shown) covers the wiring (not shown). It is arranged on one side in the thickness direction of the base insulating layer 57. The material and thickness of the cover insulating layer are the same as those of the base insulating layer 57.

[0059] The thickness of the optoelectronic hybrid substrate 5 is, for example, 20 μm or more and, for example, 200 μm or less.

[0060] The photoelectric conversion unit 6 is housed in the housing 2 and mounted on the optoelectronic hybrid substrate 5. The photoelectric conversion unit 6 is arranged to face one side in the thickness direction of the first terminal 27. The photoelectric conversion unit 6 includes a light emitting and receiving member 61 and a bump 62.

[0061] The light receiving and emitting member 61 has a generally flat rectangular shape extending in the longitudinal direction and the width direction. The light receiving and emitting member 61 includes a light receiving and emitting opening 63. A plurality of (for example, four) light receiving and emitting openings 63 are provided at intervals from each other on the other surface in the thickness direction of the light receiving and emitting member 61. The light receiving and emitting openings 63 overlap with the through hole 8 when projected in the thickness direction. This allows the optical waveguide 51 of the optical-electrical hybrid substrate 5 to be optically connected to the photoelectric conversion section 6. When projected in the thickness direction, the light receiving and emitting member 61 does not overlap with the second terminal 28 and is shifted to the other side in the longitudinal direction. Examples of the light receiving and emitting member 61 include a light emitting element that converts electricity into light, specifically a surface-emitting light emitting diode (VECSEL). Examples of the light receiving and emitting member 61 include a light receiving element that converts light into electricity, specifically a photodiode (PD) or the like. These can be used alone or in combination. In the light receiving and emitting member 61, a light emitting driving element (specifically, a Driver IC) may be provided near the light emitting element, and a light receiving driving element (specifically, a TIA) may be provided near the light receiving element.

[0062] The bump 62 is provided so as to protrude from the other surface in the thickness direction of the light receiving and emitting member 61 toward the other side in the thickness direction. The bump 62 is located around the light receiving and emitting port 63. The length (length in the thickness direction, thickness) of the bump 62 is, for example, 1 μm or more and, for example, 100 μm or less. Examples of materials for the bump 62 include conductors such as copper, gold, and solder. The bump 62 contacts the first terminal 27. This electrically connects the light receiving and emitting member 61 of the photoelectric conversion unit 6 to the electric circuit board 52 of the opto-electric hybrid substrate 5.

[0063] Furthermore, the light receiving and emitting members 61, the bumps 62, and the mounting portion of the opto-electrical hybrid board 5 are fixed and reinforced by an adhesive.

[0064] In this optical and electrical transmission composite module 1, a first wall 21, a heat dissipation layer 3, a printed wiring board 4, an optical and electrical hybrid board 5, and an optical and electrical conversion section 6 are arranged in this order toward one side in the thickness direction.

[0065] Next, a method for manufacturing this optical and electrical transmission composite module 1 will be described.

[0066] First, the heat dissipation layer 3 is disposed on the first wall 21 of the housing 2 .

[0067] Next, the heat dissipation layer 3 is placed on one thickness direction surface of the first wall 21. More specifically, the heat dissipation layer 3 is attached to one thickness direction surface of the first wall 21. When the housing 2 is composed of two members (the first member 91 and the second member 92), one longitudinal end face of the heat dissipation layer 3 is brought into contact with the connecting wall 23 of the first member 91 and the inner surfaces of both side walls.

[0068] Next, the printed wiring board 4 is placed on one surface in the thickness direction of the heat dissipation layer 3. Specifically, when the first wall 21 is included in the first member 91, the printed wiring board 4 is placed with respect to the housing 2 (first member 91) and the heat dissipation layer 3 such that the portion of the support plate 71 other than the protruding end portion 76 is attached to the heat dissipation layer 3 and the protruding end portion 76 protrudes from the connecting wall 23.

[0069] Separately, an opto-electrical hybrid board 5 and an opto-electrical conversion section 6 are prepared.

[0070] To prepare the opto-electrical hybrid board 5, the optical waveguide 51 is provided on the electric circuit board 52 by a known method. In addition, the bumps 62 are disposed on the first terminals 27, and then the light receiving and emitting members 61 are connected to the bumps 62, thereby mounting the opto-electrical conversion unit 6 on the opto-electrical hybrid board 5. In this way, the opto-electrical hybrid board 5 on which the photoelectric conversion unit 6 is mounted is prepared.

[0071] Next, the optoelectronic hybrid board 5 on which the optoelectronic conversion unit 6 is mounted is mounted on the printed wiring board 4. Specifically, the optical waveguide 51 is fixed to the printed wiring board 4 (bonded via an adhesive not shown), and the second terminal 28 and the third terminal 73 are connected via the wire 65.

[0072] Thereafter, the second member 92 including the second wall 22 is placed on the first member 91. Specifically, the connecting wall 23, the second connecting wall (not shown), and both side walls (not shown) of the second member are joined to the connecting wall 23, the second connecting wall (not shown), and both side walls (not shown) of the first member 91. In this way, the housing 2 is produced.

[0073] In this way, the optical / electrical transmission composite module 1 including the housing 2, the heat dissipation layer 3, the printed wiring board 4, the optical / electrical hybrid board 5, and the optical / electrical conversion unit 6 is manufactured.

[0074] <Effects of one embodiment> In the optical / electrical transmission composite module 1, the heat dissipation layer 3 is in contact with the first wall 21 and the printed wiring board 4, so that the heat generated in the photoelectric conversion unit 6 and reaching the heat dissipation layer 3 via the optical / electrical hybrid substrate 5 and the printed wiring board 4 can be efficiently dissipated to the first wall 21. This allows the photoelectric conversion unit 6 to operate efficiently, and further allows the heat of the photoelectric conversion unit 6 to be efficiently dissipated to the housing 2.

[0075] As described above, the material of the heat dissipation layer 3 is a filler resin composition containing a resin, and the heat dissipation layer 3 has appropriate softness, so that the heat dissipation layer 3 can flexibly contact both the first wall 21 and the printed wiring board 4. Specifically, if the Asker C hardness of the heat dissipation layer 3 is low, such as 75 or less, the heat dissipation layer 3 can be reliably adhered to the first wall 21 and the printed wiring board 4, thereby improving the heat dissipation performance.

[0076] On the other hand, in the optical module described in Patent Document 1, even if the heat dissipation sheet is flexible, the heat dissipation sheet comes into contact with the printed circuit board and the optical waveguide but does not come into contact with the housing, and therefore the above-mentioned excellent effects cannot be achieved.

[0077] Furthermore, in this optical and electrical transmission composite module 1, if the thermal conductivity of the heat dissipation layer 3 is 5 W / m·K or more, the heat generated in the photoelectric conversion section 6 can be released more efficiently.

[0078] <Modification> In the following modifications, the same reference numerals are used for the same components and steps as those in the above-described embodiment, and detailed descriptions thereof will be omitted. The embodiment and each modification can be appropriately combined. Furthermore, each modification can achieve the same effects as the embodiment, unless otherwise specified.

[0079] The optical and electrical transmission composite module 1 shown in FIG. 2 further includes a second heat dissipation layer 80 as an example of a second heat dissipation member.

[0080] The second heat dissipation layer 80 is interposed between the photoelectric conversion unit 6 and the second wall 22 and is in contact with them. The second heat dissipation layer 80 also contacts at least one thickness direction surface of the light receiving and emitting member 61. As shown by the imaginary lines in FIG. 2, the second heat dissipation layer 80 may further contact the peripheral side surfaces (both longitudinal sides and both width direction sides) of the light receiving and emitting member 61. In this case, the second heat dissipation layer 80 also contacts one thickness direction surface of the electric circuit board 52 around the photoelectric conversion unit 6.

[0081] The physical properties of the second heat dissipation layer 80 are the same as those of the heat dissipation layer 3. In particular, if the Asker C hardness of the second heat dissipation layer 80 is equal to or less than the above upper limit (preferably equal to or less than 50), the second heat dissipation layer 80 can flexibly contact the light receiving and emitting member 61 of the photoelectric conversion section 6. Damage to the photoelectric conversion section 6 caused by contact with the second heat dissipation layer 80 can be suppressed.

[0082] In particular, when the second wall 22 presses against the second heat dissipation layer 80 when the first member 91 and the second member 92 are joined together, the second heat dissipation layer 80 is likely to damage the photoelectric conversion body 6.

[0083] However, in this modified example, since the second heat dissipation layer 80 has the low Asker C hardness (for example, 55 or less) as described above, damage to the photoelectric conversion section 6 can be effectively suppressed.

[0084] To provide the second heat dissipation layer 80 in the optical / electrical transmission composite module 1, for example, the heat dissipation layer 3 is disposed on the first wall 21, the printed wiring board 4 is disposed on the heat dissipation layer 3, the optical / electrical hybrid board 5 on which the photoelectric conversion unit 6 is mounted is disposed on the printed wiring board 4, and then the second heat dissipation layer 80 is disposed on the photoelectric conversion unit 6. The second heat dissipation layer 80 is formed in a sheet shape from the same material as the heat dissipation layer 3.

[0085] Thereafter, the second member 92 including the second wall 22 is connected to the first member 91. At that time, the second wall 22, for example, presses the second heat dissipation layer 80 of the B stage toward the other side in the thickness direction. Then, the second heat dissipation layer 80 deforms and comes into contact with the peripheral side surface of the light receiving and emitting member 61 and one side in the first direction of the optical-electrical hybrid substrate 5 around the light receiving and emitting member 61.

[0086] In this way, an optical / electrical transmission composite module 1 including the housing 2, the heat dissipation layer 3, the printed wiring board 4, the optical / electrical hybrid board 5, the optical / electrical conversion section 6, and the second heat dissipation layer 80 is obtained.

[0087] This optical and electrical transmission composite module 1 further includes a second heat dissipation layer 80, and since this second heat dissipation layer 80 contacts the second wall 22, the heat generated in the photoelectric conversion unit 6 can be dissipated more efficiently. In other words, the heat of the photoelectric conversion unit 6 can be efficiently dissipated to the housing 2 by both the heat dissipation layer 3 and the second heat dissipation layer 80.

[0088] In this optical / electrical transmission composite module 1, if the second heat dissipation layer 80 has a low Asker C hardness of 55 or less, the second heat dissipation layer 80 can flexibly contact the photoelectric conversion section 6. Therefore, damage to the photoelectric conversion section 6 can be suppressed.

[0089] Furthermore, the optical / electrical transmission composite module 1 only needs to include the first terminal 27 and the second terminal 28 that are electrically connected to the optical / electrical conversion unit 6, and the optical / electrical hybrid board 5 does not need to have the optical / electrical conversion unit 6 mounted thereon yet.

[0090] As shown in FIGS. 3 to 5, the arrangement of the optical waveguide 51, the electric circuit board 52, and the photoelectric conversion section 6 in the thickness direction may be reversed.

[0091] As shown in FIG. 3, in this optical / electrical transmission composite module 1, an optical waveguide 51, an electric circuit board 52, and an optical / electrical conversion section 6 are arranged in this order toward the other side in the thickness direction.

[0092] The printed wiring board 4 has a through hole 41 penetrating in the thickness direction. The photoelectric conversion unit 6 is disposed in the through hole 41. The third terminal 73 is disposed on one side of the through hole 41 in the longitudinal direction and in the vicinity of the through hole 41. In addition, the electric circuit board 52 is fixed via an adhesive 42 to one surface of the photoelectric conversion unit 6 around the through hole 41 in the thickness direction.

[0093] In the modified example of Figure 3, the heat dissipation layer 3 contacts the other thickness-wise surface of the printed wiring board 4 and the inner surface of the through hole 41, the other thickness-wise surface and outer peripheral surface of the photoelectric conversion unit 6, and the other thickness-wise surface of the electric circuit board 52 surrounding the photoelectric conversion unit 6.

[0094] 4, a second heat dissipation layer 80 is disposed between the second wall 22 and the optical waveguide 51. The second heat dissipation layer 80 contacts the second wall 22 and the optical waveguide 51.

[0095] 5, the first wall 21 has a first protrusion 25. The second wall 22 has a second protrusion .

[0096] The first protruding portion 25 protrudes toward one side in the thickness direction at the first wall 21. The first protruding portion 25 is in contact with the heat dissipation layer 3.

[0097] The second protruding portion 26 protrudes toward the other side in the thickness direction at the second wall 22. The second protruding portion 26 contacts the second heat dissipation layer 80. EXAMPLES

[0098] The present invention will be described in more detail below with reference to preparation examples, examples, and comparative examples. The present invention is not limited to the preparation examples, examples, and comparative examples. The specific numerical values ​​of the blending ratio (ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit (a numerical value defined as "equal to or less than") or lower limit (a numerical value defined as "equal to or more than" or "exceeding") of the corresponding blending ratio (ratio), physical property values, parameters, etc. described in the above "Form for carrying out the invention".

[0099] Preparation Example 1 LiPOLY's PK95 was used as the heat dissipation sheet. (Heat dissipation sheet A)

[0100] Preparation Example 2 A varnish was prepared by mixing appropriate amounts of alumina (DAM-70, manufactured by Denka Co., Ltd.) as a filler, epoxy resin (jER828, manufactured by Mitsubishi Chemical Co., Ltd.) as a resin, and hardener (SI-60, SI-S, manufactured by Sanshin Chemical Co., Ltd.). Next, the varnish was applied to a film of about 1 mm thickness using an applicator, and then heated in an oven at 80°C for 30 minutes to produce heat dissipation sheet B.

[0101] Preparation Example 3 Heat dissipation sheet C was produced in the same manner as in Preparation Example 1, except that the amount of alumina was reduced so that the thermal conductivity would be lower than that of heat dissipation sheet B of Preparation Example 2.

[0102] <Physical properties of heat dissipation sheet> The physical properties of the heat-dissipating sheet and the second heat-dissipating sheet are shown in Table 1.

[0103] Examples 1 to 3 The optical and electrical transmission composite module 1 according to the embodiment shown in FIG. 1 was manufactured.

[0104] In Example 1, the heat dissipation sheet A was used to prepare the heat dissipation layer 3 .

[0105] In Example 2, the heat dissipation sheet B was used to prepare the heat dissipation layer 3 .

[0106] In Example 3, the heat dissipation sheet C was used to fabricate the heat dissipation layer 3.

[0107] Examples 4 to 6 The optoelectronic transmission composite module 1 of the modified example shown in FIG. 2 was manufactured. This optoelectronic transmission composite module 1 further includes a second heat dissipation layer 80.

[0108] In Example 4, two heat dissipation sheets A were used to fabricate the heat dissipation layer 3 and the second heat dissipation layer 80.

[0109] In Example 5, two heat dissipation sheets B were used to fabricate the heat dissipation layer 3 and the second heat dissipation layer 80.

[0110] In Example 6, two heat dissipation sheets C were used to fabricate the heat dissipation layer 3 and the second heat dissipation layer 80.

[0111] Comparative Example 1 The optoelectronic transmission composite module 1 shown in FIG. 6 was manufactured in the same manner as in Example 1, except that the arrangement of the printed wiring board 4 and the heat dissipation layer 3 in the thickness direction was interchanged.

[0112] In the optoelectronic transmission composite module 1 of Comparative Example 1, the first wall 21, the printed wiring board 4, the heat dissipation layer 3, the optoelectronic hybrid substrate 5, and the optoelectronic conversion unit 6 are arranged in order toward one side in the thickness direction, and the heat dissipation layer 3 does not contact the first wall 21.

[0113] <Evaluation> The following items were evaluated.

[0114] (1) Heat dissipation of the optoelectronic conversion unit The optoelectronic conversion unit 6 was driven, and the heat dissipation performance was evaluated according to the following criteria.

[0115] The temperature of the light-emitting element during driving was calculated by simulation, and the heat dissipation performance was evaluated. In the simulation, a model provided with the optoelectronic conversion unit 6 including the light-emitting element, the light-emitting driving element, the light-receiving element, and the light-receiving driving element was used, and the environment was cooled at a wind speed of 0.1 m / s. ◎: The temperature of the light-emitting element was less than 50°C. ◯: The temperature of the light-emitting element was 50° C. or higher and less than 55° C. Δ: The temperature of the light-emitting element was 55° C. or higher and less than 60° C. ×: The temperature of the light-emitting element was 60° C. or higher.

[0116] (2) Damage to the photoelectric conversion section The photoelectric conversion section 6 was observed, and damage was evaluated according to the following criteria. ⊚: No damage was observed at all in the photoelectric conversion section 6. ◯: Slight damage to the photoelectric conversion part 6 was observed.

[0117] [Table 1]

[0118] The above invention is provided as an exemplary embodiment of the present invention, but this is merely an example and should not be interpreted as being limited. Modifications of the present invention that are obvious to those skilled in the art are included in the scope of the following claims. [Industrial Applicability]

[0119] The optical and electrical transmission composite module is used for signal transmission. [Explanation of symbols]

[0120] 1. Optical and electrical transmission composite module 2. Chassis 3 Heat dissipation layer 4. Printed Wiring Boards 5. Optical / electrical hybrid board 6 Photoelectric conversion section 21 1st wall 22 Second wall 51 Optical waveguide 52 Electrical Circuit Board 80 Second heat dissipation layer

Claims

1. A photoelectric conversion unit, an opto-electrical hybrid board configured to be optically and electrically connected to the opto-electrical conversion unit and including an optical waveguide and an electric circuit board in this order toward one side in a thickness direction; a printed wiring board electrically connected to the electric circuit board; A heat dissipation member; a metal housing that houses the optical / electrical hybrid board, the printed wiring board, and a part of the heat dissipation member, the housing including a first wall; the first wall, the heat dissipation member, the printed wiring board, the optical / electrical hybrid board, and the optical / electrical conversion unit are arranged in this order toward one side in the thickness direction, The heat dissipation member is in contact with the first wall and the printed wiring board. Optical and electrical transmission composite module.

2. The heat dissipation member has an Asker C hardness of 75 or less at 23°C.

2. The optical and electrical transmission composite module according to claim 1.

3. 3. The optical and electrical transmission composite module according to claim 1, wherein the heat dissipation member has a thermal conductivity in a thickness direction of 5 W / m·K or more.

4. Further comprising a second heat dissipation member in contact with the photoelectric conversion unit, the housing further includes a second wall disposed on an opposite side of the first wall in the thickness direction with respect to the photoelectric conversion unit, 3. The optical and electrical transmission composite module according to claim 1, wherein the second heat dissipation member is interposed between the photoelectric conversion section and the second wall and is in contact with the second wall.

5. 5. The optical and electrical transmission composite module according to claim 4, wherein the second heat dissipation member has an Asker C hardness of 55 or less at 23[deg.] C.

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