JP5428632B2 - Opto-electric hybrid board, opto-electric hybrid board manufacturing method, and electronic apparatus - Google Patents

Description

  The present invention relates to an opto-electric hybrid board, a method for manufacturing an opto-electric hybrid board, and an electronic apparatus.

  In recent years, with the wave of computerization, wideband lines (broadband) capable of exchanging large amounts of information at high speed have been spreading. Also, as devices for transmitting information to these broadband lines, transmission devices such as router devices and WDM (Wavelength Division Multiplexing) devices are used. In these transmission apparatuses, a large number of signal processing boards in which arithmetic elements such as LSIs and storage elements such as memories are combined are installed, and each line is interconnected.

  Each signal processing board has a circuit in which arithmetic elements, storage elements, etc. are connected by electrical wiring. However, with the increase in the amount of information to be processed in recent years, each board has a very high throughput. It is required to transmit. However, with the speeding up of information transmission, problems such as generation of crosstalk and high-frequency noise, deterioration of electric signals, and mismatch of characteristic impedance are becoming apparent. For this reason, electrical wiring becomes a bottleneck, making it difficult to improve the throughput of the signal processing board.

  On the other hand, an optical communication technique for transferring data using an optical carrier wave has been developed, and in recent years, an optical waveguide is becoming popular as a means for guiding the optical carrier wave from one point to another point. This optical waveguide has a linear core part and a clad part provided so as to cover the periphery thereof. The core part is made of a material that is substantially transparent to the light of the optical carrier wave, and the cladding part is made of a material having a refractive index lower than that of the core part.

  In such an optical waveguide, light introduced from one end of the core portion is conveyed to the other end while being reflected at the boundary with the cladding portion. A light emitting element such as a semiconductor laser is disposed on the incident side of the optical waveguide, and a light receiving element such as a photodiode is disposed on the emission side. Light incident from the light emitting element propagates through the optical waveguide, is received by the light receiving element, and performs communication based on the blinking pattern of the received light.

  Recently, there has been a movement to replace electric wiring in a signal processing board with an optical waveguide. By replacing the electrical wiring with an optical waveguide, it is expected that the problem of the electrical wiring as described above will be solved and the signal processing board will be able to further increase the throughput.

  However, electric wiring for supplying electric power is indispensable for driving each element such as a light emitting element and a light receiving element which perform mutual conversion between an optical signal and an electric signal as well as an arithmetic element and a storage element. For this reason, electric wiring and an optical waveguide are mixedly mounted on the signal processing substrate, and development of such a substrate (photoelectric mixed substrate) is being promoted.

  For example, in Patent Document 1, an optical transmission IC and an optical reception IC are mounted, and a thin-film optical waveguide for transmitting an optical signal between the optical transmission IC and the optical reception IC is formed. A printed circuit board capable of transmitting an optical signal is described. The printed board is provided with a through-hole penetrating in the thickness direction, and through this through-hole, between the optical transmission IC and the optical waveguide mounted on different surfaces of the printed board, and the light The receiving IC and the optical waveguide are connected to each other.

  Further, both end surfaces of the optical waveguide are processed so as to obliquely cross the optical waveguide, and the light traveling direction is changed by reflecting light at the both end surfaces. That is, mirrors (optical path conversion structures) are formed at both ends of the optical waveguide.

  By the way, the formation of this mirror requires extremely high processing accuracy, but it is difficult to perform high-precision processing on a thin-film optical waveguide. For this reason, the accuracy of the processed surface cannot be sufficiently increased, and there is a problem that the coupling loss between the optical transmission IC and the optical waveguide and between the optical reception IC and the optical waveguide increases.

  Further, the reflection angle at the mirror greatly depends on the processing accuracy of the mirror. However, as described above, it is difficult to increase the processing accuracy of the mirror, so that the positional relationship between each IC and the optical waveguide is not stable, and the difficulty of alignment becomes extremely high.

  On the other hand, Patent Document 2 describes an opto-electric hybrid wiring board having a printed wiring board and a light emitting element and a light receiving element provided thereon. The light emitting element and the light receiving element are arranged so that the light emitting point and the light receiving point face each other, and the light emitting point and the light receiving point are directly coupled by an optical waveguide.

  In the opto-electric hybrid board having such a configuration, the coupling loss between the light emitting element or the light receiving element and the optical waveguide is suppressed, but when the optical waveguide is fixed between the light emitting element and the light receiving element, Difficulty in alignment. In particular, an operation of accurately aligning both ends with respect to each element while pulling the optical waveguide in a suspended state requires advanced and delicate techniques. If the length of the optical waveguide and the distance between the two elements do not match, it is impossible to achieve both optical connection and mechanical fixation between the optical waveguide and the two elements. For this reason, it is not easy to manufacture a highly reliable opto-electric hybrid board that suppresses coupling loss, resulting in a significant reduction in productivity.

  Further, the light emitting element and the light receiving element are usually mounted in a CAN package. However, as shown in Patent Document 2, when the flat part of the CAN package and the printed wiring board are fixed vertically, the light emitting element and the light receiving element are fixed. Since the contributing area is small, sufficient fixing strength cannot be obtained.

JP 2005-294407 A JP 2004-206015 A

  It is an object of the present invention to easily align a light emitting / receiving element and an optical circuit and to reliably suppress a coupling loss between them, and to efficiently manufacture such an opto-electric hybrid board. Another object of the present invention is to provide an opto-electric hybrid board manufacturing method and an electronic apparatus including the opto-electric hybrid board.

Such an object is achieved by the present inventions (1) to (14) below.
(1) an optical circuit board having an optical circuit;
An electric circuit board laminated on the optical circuit board and having an electric circuit;
An optical-electric hybrid board comprising: an optical element for chromatic said optical circuit and a light receiver or the light emitting portion is optically connected,
Has end exposed of the optical circuit on the end face of the optical circuit board, so that the end portion of the optical circuit and the light receiving portion or the light emitting portion are opposed to each end face of the optical circuit substrate and the optical element are bonded through an adhesive having optical transparency between,
The end of the electric circuit is exposed at the end surface of the electric circuit board, and the solder spreads in the gap between the end of the electric circuit and the optical element, whereby the end of the electric circuit and the optical element And an opto-electric hybrid board.

  (2) The opto-electric hybrid board according to (1), wherein the adhesive is an adhesive sheet formed by forming an adhesive component into a sheet.

(3) The above-mentioned (1) or () , wherein the end portion of the electric circuit is formed with a base layer for preventing the metal component in the electric circuit from eluting into the solder as the base of the solder. The opto-electric hybrid board according to 2) .

(4) The constituent material of the electric circuit is mainly composed of Cu,
The opto-electric hybrid board according to (3) , wherein the constituent material of the underlayer includes at least one of Au and Ni.

(5) an optical circuit board having an optical circuit;
  An electric circuit board laminated on the optical circuit board and having an electric circuit;
  An opto-electric hybrid board comprising: an optical element having a light receiving part or a light emitting part optically connected to the optical circuit,
  The end face of the optical circuit board is exposed to the end face of the optical circuit board, and the end face of the optical circuit board and the optical element are arranged so that the end of the optical circuit faces the light receiving section or the light emitting section. Are bonded through an adhesive having light transmittance,
  An end portion of the electric circuit is exposed at an end surface of the electric circuit board, and the end portion is partially thickened as compared to a portion other than the end portion of the electric circuit, and the end of the electric circuit An opto-electric hybrid board, wherein the optical element is electrically connected to the optical element.

(6) The opto-electric hybrid board according to (5) , wherein the thickened portion of the electric circuit is configured by a bump portion having a protruding shape.

(7) the electric circuit board, and the electric circuit, to support the electrical circuit, which comprises a supporting substrate through hole is formed, a,
The opto-electric hybrid board according to (5) , wherein the thickened portion of the electric circuit is configured by a through wiring portion provided in the through hole.

(8) The electrical connection between the thickened portion of the electric circuit and the optical element is performed via a conductive material provided in the gaps (5) to ( 5) The opto-electric hybrid board according to any one of 7) .

(9) an optical circuit board having an optical circuit;
  An electric circuit board laminated on the optical circuit board and having an electric circuit;
  An opto-electric hybrid board comprising: an optical element having a light receiving part or a light emitting part optically connected to the optical circuit,
  The end of the optical circuit is exposed at the end face of the optical circuit board, and the optical element is placed on the end face of the optical circuit board so that the end of the optical circuit faces the light receiving section or the light emitting section. Is placed,
  One sheet formed by forming an adhesive component into a sheet shape between the end face of the optical circuit board and the optical element, and between the optical circuit board and the electric circuit board, and being bent in the middle. An opto-electric hybrid board, wherein at least a portion corresponding to an end face of the optical circuit board and the optical element is bonded by an adhesive sheet having light transmittance.

(10) an optical circuit board having an optical circuit;
An electric circuit board laminated on the optical circuit board and having an electric circuit;
Having said optical circuit and optically connected to light receiving unit or a light emitting unit, a method of manufacturing an optical-electric hybrid board comprising, said electrical circuit and electrically connected to the optical device,
Laminating the optical circuit board and the electric circuit board with solder attached to the end of the electric circuit, to obtain a laminate,
After attaching an adhesive to the end face of the laminate or the optical element, the end face of the laminate and the optical element are bonded via the adhesive, and the optical circuit and the light receiving part or the light emitting part are bonded. A second step of optically connecting;
A third step of electrically connecting the electrical circuit and the optical element by melting the solder and spreading the solder in a gap formed between the electrical circuit and the optical element ; A method for manufacturing an opto-electric hybrid board, comprising:

(11) An end portion of the electric circuit is formed so as to be exposed on an end surface of the electric circuit board,
End of the electric circuit is exposed on the end surface of the electric circuit board, the opto-electric hybrid board according to (10) and is formed by cutting the electric circuit board in the course of the electric circuit Production method.

(12) A method of cutting the electric circuit board in the middle of the electric circuit includes a step of forming a groove so as to penetrate the electric circuit in a thickness direction;
Forming a base layer for preventing the metal component in the electrical circuit from eluting into the solder as the solder base for the electrical circuit;
Manufacturing method of the opto-electric hybrid board according to the above (11) having, a step of cutting the electrical circuit board so as to cross the groove.

(13) In the second step, the laminated body of the optical circuit board and the electric circuit board is arranged so as to be parallel to the vertical direction, and the flip chip is formed on the end surface of the optical circuit board facing vertically upward. The method for manufacturing an opto-electric hybrid board according to any one of (10) to (12) , wherein the optical element is arranged by a bonder.

(14) An electronic apparatus comprising the opto-electric hybrid board according to any one of (1) to (9) .

  According to the present invention, in the optical connection between the light emitting / receiving element and the optical circuit, it is not necessary to use an optical path conversion structure such as a mirror, so that no optical loss occurs during the optical path conversion, and the optical loss in the optical circuit Can be obtained.

FIG. 3 is a perspective view showing an embodiment of the opto-electric hybrid board of the present invention (partially shown). It is the sectional view on the AA line of FIG. It is a figure for demonstrating the manufacturing method of the opto-electric hybrid board shown in FIG. It is a figure for demonstrating the manufacturing method of the opto-electric hybrid board shown in FIG. It is a figure for demonstrating the manufacturing method of the opto-electric hybrid board shown in FIG. It is a figure for demonstrating the manufacturing method of the opto-electric hybrid board shown in FIG. It is a figure which shows the other structural example of the opto-electric hybrid board shown in FIG. It is a figure for demonstrating the manufacturing method of the opto-electric hybrid board shown in FIG. It is a figure which shows the other structural example of the opto-electric hybrid board shown in FIG. It is a figure for demonstrating the manufacturing method of the opto-electric hybrid board shown in FIG. It is a figure which shows the other structural example of the manufacturing method of the opto-electric hybrid board shown in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an opto-electric hybrid board, a method for manufacturing an opto-electric hybrid board, and an electronic apparatus according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<Opto-electric hybrid board>
FIG. 1 is a perspective view showing an embodiment of the opto-electric hybrid board of the present invention (partially shown), FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIGS. It is a figure for demonstrating the manufacturing method of the opto-electric hybrid board shown in FIG. In the following description, the upper side in FIGS. 1 to 6 is referred to as “upper” and the lower side is referred to as “lower”.

  An opto-electric hybrid board 1 shown in FIG. 1 includes an optical circuit board 2 including an optical circuit 22 formed of an optical waveguide, and an electric circuit board 3 including an electric circuit 32 stacked thereon. The optical circuit board 2 and the electric circuit board 3 are bonded via a bonding sheet (adhesive sheet) 41.

  Moreover, the opto-electric hybrid board 1 has a light emitting / receiving element 5 provided on an end face of the laminated board.

  The light emitting / receiving element 5 includes a light emitting / receiving section 52 responsible for light emission or light reception of an optical signal, and an electrical connection pad 53 for inputting / outputting an electric signal for driving the light receiving / emitting element 5.

  The light emitting / receiving unit 52 of the light emitting / receiving element 5 is optically connected to the optical circuit 22 without interposing an optical path changing structure such as a mirror. At the same time, the electrical connection pad 53 of the light emitting / receiving element 5 is electrically connected to the electrical circuit 32 via the terminal portion 34. As a result, the light emitting / receiving element 5 emits an optical signal to the optical circuit 22 and can receive the optical signal propagated through the optical circuit 22.

  Such an opto-electric hybrid board 1 does not need to use an optical path conversion structure such as a mirror, so that no optical loss occurs during optical path conversion, and the optical loss in the optical circuit can be greatly suppressed. . Furthermore, when the light emitting / receiving element 5 is aligned, since there is no optical path conversion structure such as a mirror, variations in the optical path are suppressed. For this reason, at the time of alignment, for example, the center axis of the core portion 224 and the center of the light receiving / emitting portion 52 may be matched, and the process can be simplified.

Hereinafter, each part of the opto-electric hybrid board 1 will be described in detail.
(Optical circuit board)
An optical circuit board 2 shown in FIG. 1 includes a layered optical circuit 22 and a support substrate 21 that supports the optical circuit board 22 from below.

  The optical circuit 22 includes an optical waveguide in which a cladding layer (lower cladding layer) 221, a core layer 223, and a cladding layer (upper cladding layer) 222 are laminated in this order from below. Among these, the core layer 223 is formed with a long core portion 224 in a plan view and a side clad portion 225 adjacent to the side surface of the core portion 224. It should be noted that dense dots are attached to the core portion 224 shown in FIG. 1, and sparse dots are attached to the side clad portions 225.

Both end portions of the core portion 224 are exposed at the end face of the core layer 223, respectively.
In the optical circuit board 2 shown in FIG. 1, the light incident on one end of the core part 224 is totally transmitted at the interface between the core part 224 and the clad parts (the clad layers 221 and 222 and the side clad parts 225). By reflecting and propagating to the other side, it can be taken out from the other end of the core part 224. Thereby, optical communication can be performed based on the blinking pattern of the light received on the emission end side.

  In order to cause total reflection at the interface between the core part 224 and the clad part, a difference in refractive index needs to exist at the interface. Although the refractive index of the core part 224 should just be larger than the refractive index of a clad part, the difference is not specifically limited, However, It is preferable that it is 0.5% or more, and it is more preferable that it is 0.8% or more. On the other hand, the upper limit value may not be set, but is preferably about 5.5%. If the difference in refractive index is less than the lower limit, the effect of transmitting light may be reduced, and even if the upper limit is exceeded, no further increase in light transmission efficiency can be expected.

The refractive index difference is expressed by the following equation, where A is the refractive index of the core portion 224 and B is the refractive index of the cladding portion.
Refractive index difference (%) = | A / B-1 | × 100

  In the configuration shown in FIG. 1, the core portion 224 is formed in a straight line shape in a plan view, but may be curved or branched in the middle, and the shape is arbitrary.

  1 has a quadrangular shape such as a square or a rectangle (rectangle) in cross-sectional shape.

  The width and height of the core part 224 are not particularly limited, but are preferably about 1 to 200 μm, more preferably about 5 to 100 μm, and still more preferably about 20 to 70 μm.

  The constituent material of the core layer 223 is not particularly limited as long as the above-described refractive index difference is generated, but specifically, acrylic resin, methacrylic resin, polycarbonate, polystyrene, epoxy resin, polyamide, polyimide, polybenzo In addition to various resin materials such as oxazole, polysilane, polysilazane, and cyclic olefin resins such as benzocyclobutene resin and norbornene resin, glass materials such as quartz glass and borosilicate glass can be used.

  Of these, norbornene resins are particularly preferable. These norbornene-based polymers include, for example, ring-opening metathesis polymerization (ROMP), combination of ROMP and hydrogenation reaction, polymerization by radical or cation, polymerization using a cationic palladium polymerization initiator, and other polymerization initiators ( For example, it can be obtained by any known polymerization method such as polymerization using a polymerization initiator of nickel or another transition metal).

  On the other hand, the clad layers 221 and 222 constitute clad portions located below and above the core layer 223, respectively. With such a configuration, each core portion 224 functions as a light guide path whose outer periphery is surrounded by the clad portion.

  The average thickness of the clad layers 221 and 222 is preferably about 0.1 to 1.5 times the average thickness of the core layer 223 (the average height of each core portion 224). More preferably, the average thickness of the clad layers 221 and 222 is not particularly limited, but is usually preferably about 1 to 200 μm and about 5 to 100 μm, respectively. More preferably, it is about 10 to 60 μm. Thereby, the function as a clad layer is suitably exhibited while preventing the optical circuit 22 from becoming unnecessarily large (thickened).

  Further, as the constituent material of the clad layers 221 and 222, for example, the same material as the constituent material of the core layer 223 described above can be used, but a norbornene polymer is particularly preferable.

  Further, when selecting the constituent material of the core layer 223 and the constituent materials of the clad layers 221, 222, the material may be selected in consideration of the difference in refractive index between them. Specifically, the material may be selected so that the constituent material of the core layer 223 becomes sufficiently large in order to surely totally reflect light at the boundary between the core layer 223 and the cladding layers 221 and 222. Thereby, a sufficient refractive index difference is obtained in the thickness direction of the optical circuit 22, and light can be prevented from leaking from the respective core portions 224 to the cladding layers 221 and 222.

  From the viewpoint of suppressing light attenuation, it is also important that the adhesiveness (affinity) between the constituent material of the core layer 223 and the constituent materials of the cladding layers 221 and 222 is high.

  The support substrate 21 is a substrate that supports the optical circuit 22 provided below one end of the optical circuit 22.

  As the support substrate 21, a flexible substrate having relatively high flexibility or a rigid substrate having relatively high rigidity is used.

  Among these, specific examples of the flexible substrate include a flexible insulating substrate included in a polyester copper-clad film substrate, a polyimide copper-clad film substrate, an aramid copper-clad film substrate, and the like.

  The average thickness of the flexible substrate is preferably about 5 to 200 μm and more preferably about 10 to 100 μm from the viewpoint of flexibility and thinning of the opto-electric hybrid board 1. A flexible substrate having such a thickness has sufficient flexibility and prevents unintentional deformation due to its own weight or the weight of various elements to be mounted.

  On the other hand, as specific examples of rigid substrates, glass substrate copper-clad laminates such as glass cloth and epoxy copper-clad laminates, composite copper-clad laminates such as glass nonwoven fabric and epoxy copper-clad laminates, polyetherimide resin substrates, Examples thereof include heat-resistant / thermoplastic organic rigid substrates included in polyetherketone resin substrates, polysulfone-based resin substrates and the like, and ceramic rigid substrates included in alumina substrates, aluminum nitride substrates, silicon carbide substrates and the like.

(Electric circuit board)
An electric circuit board 3 shown in FIG. 1 is a laminated board having an electric circuit 32, a support substrate 31 that supports the electric circuit 32 from below, and a resist layer (solder resist) 33 that covers the electric circuit 32.

  Further, there is a partially missing region near the left end of the resist layer 33 shown in FIG. 2, and a terminal portion 34 is provided in that region. The terminal portion 34 is in contact with the lower electric circuit 32, and thereby the electric circuit 32 and the terminal portion 34 are electrically connected.

  Although not shown, the electric circuit 32 is formed by patterning a conductive layer into a predetermined shape. The electric circuit 32 electrically connects the light emitting / receiving element 5 to a power source and various ICs (not shown), and has a function of supplying drive power to the light emitting / receiving element 5 and sending a control signal. It is. The electric circuit 32 can control the driving of the light emitting / receiving element 5.

  The average thickness of the conductive layer constituting the electric circuit 32 is appropriately set according to the constituent material of the electric circuit 32, the electric resistance value required for the electric circuit 32, and the like, but is about 1 to 30 μm as an example. .

  Examples of the constituent material of the electric circuit 32 include aluminum (Al), copper (Cu), gold (Au), silver (Ag), platinum (Pt), nickel (Ni), tungsten (W), and molybdenum (Mo). And various metal materials.

The support substrate 31 is a substrate that is provided below the electric circuit 32 and supports the electric circuit 32.
As the support substrate 31, the thing similar to the support substrate 21 mentioned above is used.

The resist layer 33 is an insulating film (solder resist) provided so as to cover a region excluding the terminal portion 34 on the upper surface of the electric circuit 32.
Examples of the constituent material of the resist layer 33 include various thermosetting resins.

  By providing such a resist layer 33, a part of the electric circuit 32 is exposed in a region where the terminal portion 34 is to be formed on the upper surface of the electric circuit 32, and the other region is covered with the resist layer 33. It will be. Thereby, when the electric circuit board 3 provided with the resist layer 33 is immersed in molten solder or brought into contact with the molten solder, the solder adheres only to a region where the electric circuit 32 is exposed. As a result, the terminal portion 34 made of solder can be efficiently formed in this region.

  As the solder constituting the terminal portion 34, for example, Sn-Pb lead solder, Sn-Ag-Cu system, Sn-Zn-Bi system, Sn-Cu system, Sn-Ag-In-Bi system, Sn-Zn-Al-based various lead-free solders, various low-temperature brazing materials and the like can be mentioned.

  The terminal portion 34 is obtained by firing after supplying a conductive material other than solder, such as a conductive paste (solder paste, Ag paste, Cu paste, Au paste, etc.) or conductive ink. May be.

  Moreover, when the terminal part 34 is comprised with solder, there exists a possibility that the phenomenon in which a part of metal component which comprises the electric circuit 32 melt | dissolves in the solder side may arise. This phenomenon is called “copper erosion” because it often occurs particularly with respect to copper wiring. Hereinafter, an example of copper erosion will be described.

  If copper erosion occurs, the electric circuit 32 may be thinned or disconnected, and the function of the electric circuit 32 may be impaired.

  Therefore, it is preferable to form a copper erosion preventive film (underlayer) on the surface of the electric circuit 32 in contact with the terminal portion 34 as a solder base prior to the formation of the terminal portion 34. By forming the copper erosion prevention film, copper erosion is prevented and the function of the electric circuit 32 can be maintained for a long period of time.

  Examples of the constituent material of the copper corrosion prevention film include nickel (Ni), gold (Au), platinum (Pt), tin (Sn), palladium (Pd), and the like. A single layer composed of one kind of metal composition may be used, or a composite layer containing two or more kinds (for example, a Ni—Au composite layer, a Ni—Sn composite layer, etc.) may be used.

  The average thickness of the copper erosion preventing film is not particularly limited, but is preferably about 0.05 to 5 μm, and more preferably about 0.1 to 3 μm. Thereby, it is possible to exhibit a sufficient copper erosion preventing action while suppressing the electrical resistance of the copper erosion preventing film itself.

(Bonding sheet)
The bonding sheet 41 is a sheet-like adhesive that bonds between the optical circuit board 2 and the electric circuit board 3 and between the optical circuit board 2 and the light receiving and emitting element 5. The bonding sheet 41 is light transmissive.

  Such a bonding sheet 41 is preferably made of a material having a lower refractive index than the cladding layer 222 of the optical circuit 22. As a result, the interface between the optical circuit 22 and the electric circuit board 3 has a lower refractive index than that of the optical circuit 22, so that light leakage from the optical circuit 22 can be suppressed. As a result, the transmission loss of the optical circuit 22 can be reduced.

  Here, examples of the bonding sheet 41 include a sheet formed by molding an adhesive containing at least one of a thermosetting resin, a urethane resin, and an acrylic resin.

  Examples of thermosetting resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD type epoxy resins, bisphenol type epoxy resins such as bisphenol S type epoxy resins, phenol novolac type epoxy resins, and cresol novolac type epoxies. In addition to various epoxy resins such as novolak type epoxy resins such as resins, aromatic epoxy resins such as trisphenolmethane triglycidyl ether, naphthalene type epoxy resins and dicyclopentadiene type epoxy resins, such as polyimide and polyamideimide Examples thereof include imide resins, silicone resins, phenol resins, urea resins, and the like, and one or more of them can be used in combination.

  Specific examples of the bonding sheet 41 include SB30 manufactured by Kyoku Giken Chemical Co., Ltd., E50 manufactured by Shin-Etsu Chemical Co., Ltd., TSU0042 manufactured by Toyo Ink Manufacturing Co., Ltd., and the like.

  The constituent material of the bonding sheet 41 is made of the above-mentioned thermosetting resin such as acrylonitrile-butadiene rubber (NBR), reactive terminal carboxyl group NBR (CTBN), styrene-butadiene rubber (SBR), polybutadiene, acrylic rubber, etc. A rubber component, a vinyl acetate resin, a polyvinyl alcohol resin, a polyvinyl acetal resin, an acrylic resin, a polyacrylonitrile resin, a vinyl urethane resin, a polyester resin, or a thermoplastic resin such as a polyamide resin may be contained. The content of these rubber components and thermoplastic resin is preferably about 10 to 200% by mass, more preferably about 20 to 150% by mass, respectively, based on the epoxy resin.

  Furthermore, additives such as various curing agents such as amine-based curing agents and phenol-based curing agents, curing accelerators, and silane coupling agents may be added to the thermosetting resin as necessary. .

  The bonding sheet 41 is pre-cured (semi-cured) by adding a solvent to the raw material (adhesive component) as described above, applying the obtained liquid material on the substrate, and heating the obtained liquid film. It is formed by doing. This pre-curing is performed by heating the liquid film at a temperature below the curing temperature of the thermosetting resin and above the softening point of the thermoplastic resin. As a specific example of the heating conditions in the pre-curing, it is about 50-100 ° C. × 5-60 seconds. In such a pre-cured state, the adhesiveness of the bonding sheet 41 is relatively weak, so that the re-adhesion (repair) can be easily performed.

  The average thickness of the bonding sheet 41 is not particularly limited, but is preferably about 1 to 100 μm, and more preferably about 5 to 50 μm. By setting the thickness of the bonding sheet 41 within the above range, the bonding sheet 41 can securely bond between the optical circuit board 2 and the electric circuit board 3 and between the optical circuit board 2 and the light receiving and emitting element 5 respectively. In addition, it has sufficient light transmittance. Therefore, the optical circuit board 2 and the light emitting / receiving element 5 are securely fixed, and the bonding sheet 41 is transmitted even if the bonding sheet 41 is interposed between the optical circuit board 2 and the light receiving / emitting element 5. It is possible to sufficiently suppress the optical loss during the process.

  Furthermore, if the thickness of the bonding sheet 41 is within the above range, the bonding sheet 41 itself can be expected to reduce the difference in thermal expansion between the optical circuit board 2 and the light emitting / receiving element 5. Thereby, the opto-electric hybrid board 1 provided with the bonding sheet 41 can prevent problems such as a deformation such as a curve and an increase in optical loss associated therewith.

(Light emitting / receiving element)
The light emitting / receiving element 5 is a light emitting element that converts an electric signal into an optical signal and enters the optical signal 22 or a light receiving element that receives an optical signal emitted from the optical circuit 22 and converts it into an electric signal.

  Examples of the light emitting element include a surface emitting laser (VCSEL), a light emitting diode (LED), and the like, and examples of the light receiving element include a photodiode (PD, APD).

  The light emitting / receiving element 5 shown in FIG. 2 includes a package 51, and a light receiving / emitting part 52 provided at a position facing the end face of the core part 224 on the side surface of the package 51, and an electric provided at a position facing the terminal part 34. And a connection pad 53.

  The light emitting / receiving element 5 is bonded to the optical circuit board 2 by the bonding sheet 41 described above. As a result, the end face of the optical circuit 22 and the light emitting / receiving unit 52 are arranged to face each other, and the space between them is fixed and optically connected.

  Further, the solder constituting the terminal portion 34 is melted and fluidized by reflow and is in contact with the electrical connection pad 53 located in the vicinity of the terminal portion 34. As a result, the electrical circuit 32 and the electrical connection pad 53 are fixed and electrically connected via the terminal portion 34.

  The left end face of the electric circuit 32 is exposed at the end face of the electric circuit board 3 as shown in FIG. The molten solder wets and spreads on the left end face of the electric circuit 32, so that the electric circuit 32 and the electric connection pad 53 are connected in a wider area. As a result, it is possible to reliably relieve stress that tends to concentrate on the connection portion.

  The opto-electric hybrid board 1 as described above does not need to use an optical path conversion structure such as a mirror as described above, so that it is possible to greatly suppress optical loss during optical path conversion. Furthermore, when aligning the light emitting / receiving element 5, for example, the central axis of the core portion 224 and the center of the light receiving / emitting portion 52 may be aligned, and the alignment process can be simplified.

  Therefore, according to the opto-electric hybrid board of the present invention, a high-quality opto-electric hybrid board 1 having high optical connectivity and high electrical connectivity can be obtained.

<Method for manufacturing opto-electric hybrid board>
Next, the manufacturing method of the opto-electric hybrid board 1 as described above (the opto-electric hybrid board manufacturing method of the present invention) will be described.

  The opto-electric hybrid board 1 shown in FIG. 1 is prepared with an optical circuit board 2, an electric circuit board 3, and a bonding sheet 41, and after laminating them, the obtained laminate and the light emitting / receiving element 5 are bonded. It is manufactured by.

  The optical circuit board 2 is manufactured by preparing the clad layer 221, the core layer 223, the clad layer 222, and the support substrate 21 and laminating them.

  Furthermore, the electric circuit board 3 is manufactured by forming a conductive layer on which the electric circuit 32 is formed on the support substrate 31, and then sequentially forming a resist layer 33 and a terminal portion.

Hereinafter, a method for manufacturing the opto-electric hybrid board 1 will be sequentially described.
[1] Manufacture of electric circuit board [1-1] First, the support substrate 31 is prepared, and a conductive layer is formed so as to cover a part or all of the upper surface thereof.

  This conductive layer is a film having the above-described metal composition, and such a film is formed by chemical vapor deposition such as plasma CVD, thermal CVD, or laser CVD, physical vapor deposition such as vacuum vapor deposition, sputtering, or ion plating, electroplating, It is formed by a plating method such as electroless plating, a thermal spraying method, a sol-gel method, a MOD method, or the like.

Next, this conductive layer is patterned by various patterning methods. Examples of the patterning method include a method in which a photolithography method and an etching method are combined.
As described above, the electric circuit 32 is formed in the conductive layer.

  The method for forming the electric circuit 32 is not limited to the above method, and a conductive paste, a conductive ink, or the like is supplied to a predetermined region on the upper surface of the support substrate 31 (along the pattern of the electric circuit 32). Thereafter, a firing method may be used. Examples of the supply method include various printing methods and various coating methods.

  [1-2] Next, a resist layer 33 is formed on the conductive layer on which the electric circuit 32 is formed (see FIG. 3A).

  The resist layer 33 is formed by applying a forming composition to form a liquid film and then evaporating (desolving) the solvent. Note that the resist layer 33 is formed so that a part of the resist layer 33 is missing, but this part (the missing part 330 in FIG. 3A) is cut in a process to be described later in a region where the terminal part 34 is formed. Therefore, it is formed to include this region.

  Next, the defect portion 330 is cut along the cutting line CL shown in FIG. 3B in accordance with the region where the terminal portion 34 is formed. The defect portion 330 is cut along the width direction (the depth direction of the paper surface of FIG. 3), so that a region for forming the terminal portion 34 is easily formed in the defect portion 330 after cutting. Become. In FIG. 3C, this region is a terminal portion formation region 340, and the end surface of the conductive layer adjacent to this terminal portion formation region 340 is a conductive layer end surface 341.

  For the cutting of the support substrate 31 and the electric circuit 32, a dicer such as a blade-cut dicer or a laser dicer is used.

  The left part of FIG. 3 divided by cutting is normally discarded, but the left part can also be used for manufacturing the electric circuit board 3 by optimizing the position of the cutting line CL. In this case, what is necessary is just to design the structure on either side with respect to the cutting line CL so that a line-symmetrical relationship may be satisfy | filled. Thereby, the two members divided by cutting are substantially equivalent to each other. Therefore, two members for manufacturing the electric circuit board 3 can be manufactured simultaneously by a single cutting process.

  [1-3] Next, the above-described copper erosion prevention film (not shown) is formed on the terminal portion formation region 340 and the conductive layer end surface 341. Such a copper erosion prevention film is formed by various plating methods such as an electroplating method and an electroless plating method (see FIG. 3D).

  The formation region of the copper erosion prevention film is not limited to the above example, and may be formed only on the terminal portion formation region 340 or only on the conductive layer end surface 341.

  [1-4] Next, the molten solder is brought into contact with the terminal portion forming region 340. As a result, the molten solder adheres to the terminal portion forming region 340, and the terminal portion 34 is formed (see FIG. 3E).

  The method for forming the terminal portion 34 by bringing molten solder into contact with the terminal portion forming region 340 has been described above. However, as described above, the terminal portion 34 can be formed by a method other than the above method.

  Specifically, a method of applying a solder paste to the terminal portion forming region 340, a method of plating solder, and the like can be mentioned.

  Among these, examples of the solder paste coating method include various coating methods (printing methods) such as a roll coating method, a screen printing method, an ink jet printing method, and a dispenser coating method.

  On the other hand, examples of the method for plating the solder include various plating methods such as an electrolytic plating method and an electroless plating method.

In addition, the terminal portion 34 can also be formed by placing a solder material such as a solder ball or solder flake on the terminal portion forming region 340 and then melting the solder material.
The electric circuit board 3 is manufactured as described above.

[2] Manufacture of Optical Circuit Board [2-1] First, the cladding layer 221, the core layer 223, and the cladding layer 222 are respectively manufactured. On these substrates, after forming the liquid film by applying the composition for forming each layer on the base material, in the level table where the base material is ventilated, the uneven surface portion of the liquid film surface is leveled. Formed by evaporation (desolvation) of the solvent.

  Examples of the coating method for forming the liquid film include a doctor blade method, a spin coating method, a dipping method, a table coating method, a spray method, an applicator method, a curtain coating method, and a die coating method.

  In addition, as a method for forming the core portion 224 and the side cladding portion 225 in the same layer (core layer 223), for example, a photobleaching method, a photolithography method, a direct exposure method, a nanoimprinting method, a monomer Examples include the diffusion method.

  Then, the formed clad layer 221, core layer 223, and clad layer 222 are pressure-bonded to each other. Thereby, the clad layer 221, the core layer 223, and the clad layer 222 are joined and integrated, and the optical circuit 22 is obtained.

  [2-2] Next, the support substrate 21 is prepared, and the manufactured optical circuit 22 and the support substrate 21 are laminated.

The optical circuit 22 and the support substrate 21 may be bonded with various adhesives (including an adhesive). However, when the cladding layer 221 has adhesiveness, The support substrate 21 may be directly bonded.
The optical circuit board 2 is manufactured as described above.

[3] Lamination of Electric Circuit Board and Optical Circuit Board First, as shown in FIG. 4 (f), a bonding sheet 41 is attached to the lower surface of the electric circuit board 3. At this time, among the end portions of the bonding sheet 41, the left end portion is pasted so as not to overlap the electric circuit board 3. That is, the bonding is performed so that the left end portion of the bonding sheet 41 protrudes from the electric circuit board 3. The length of the portion that does not overlap the electric circuit board 3 is equal to or greater than the thickness of the optical circuit board 2.

  Next, as shown in FIG. 4G, the optical circuit board 2 is attached to the lower surface of the bonding sheet 41. Thereby, the electric circuit board 3 and the optical circuit board 2 are laminated via the bonding sheet 41 (first step).

  At this time, it is preferable to laminate so that the left end face of the electric circuit board 3 and the left end face of the optical circuit board 2 coincide.

  Next, as shown in FIG. 4H, the left end of the bonding sheet 41 is bent toward the optical circuit board 2 side. The bent portion of the bonding sheet 41 is a bent portion 410 shown in FIG. The bent portion 410 is bonded so as to cover the end surface of the optical circuit board 2.

  The bent portion 410 serves to bond the end face of the optical circuit board 2 and the light emitting / receiving element 5. In this way, by bending a part of the bonding sheet 41 responsible for adhesion between the electric circuit board 3 and the optical circuit board 2, the bonding sheet 41 is attached to the end face of the optical circuit board 2 which is a very narrow area. Can be pasted easily and accurately.

  In addition, the electrical circuit board 3 and the optical circuit board 2 and the end face of the optical circuit board 2 and the light emitting / receiving element 5 may be bonded with individual bonding sheets. As described above, since one bonding sheet 41 is used while being bent in the middle, it is not necessary to align each other as compared with the case where individual bonding sheets are used, so that the bonding operation becomes easier. is there.

  In addition, when bonding between the electric circuit board 3 and the optical circuit board 2 and between the end face of the optical circuit board 2 and the light emitting / receiving element 5 with individual bonding sheets, the electric circuit board 3 and The bonding sheet for bonding between the optical circuit board 2 and the optical circuit board 2 does not necessarily have to be light transmissive.

  Further, in this case, when the end face of the optical circuit board 2 and the light receiving / emitting element 5 are bonded with a bonding sheet, the bonding sheet is used for bonding in a state of being bonded to the end face of the optical circuit board 2 in advance. On the contrary, it may be used for bonding in a state of being attached to the light emitting / receiving element 5. In some cases, the bonding sheets may be bonded to each other and then bonded to each other.

  Further, the electric circuit board 3 and the optical circuit board 2 may be bonded by a method other than the bonding sheet.

  Examples of this method include thermocompression bonding and adhesion using an adhesive (including a pressure-sensitive adhesive).

  Among these, the thermocompression bonding is performed by developing the adhesiveness by heating when the clad layer 222 has adhesiveness or when the support substrate 31 of the electric circuit board 3 has adhesiveness. In this method, the electrical circuit board 3 and the optical circuit board 2 are bonded together.

On the other hand, as an adhesive agent, various hot-melt-adhesives (polyester type | system | group, modified olefin type | system | group) etc. are mentioned other than an acrylic adhesive, a urethane type adhesive agent, a silicone type adhesive agent, for example. Moreover, as a thing with especially high heat resistance, thermoplastic polyimide adhesive agents, such as a polyimide, a polyimide amide, a polyimide amide ether, a polyester imide, a polyimide ether, are mentioned.
As described above, the laminated substrate (laminated body) 10 shown in FIG.

[4] Mounting of light emitting / receiving element First, as shown in FIG. 5I, the obtained laminated substrate 10 is rotated and fixed so that the bent portion 410 faces upward. In other words, the laminated substrate 10 is arranged so as to be parallel to the vertical direction so that the bent portion 410 is vertically upward.

  Next, the light emitting / receiving element 5 is placed on the end surface (on the bent portion 410) of the multilayer substrate 10 from above (second step). This placement can be performed using, for example, various bonders such as a flip chip bonder. Thereby, the incident end or the emission end of the optical circuit 22 and the light emitting / receiving unit 52 of the light receiving / emitting element 5 can be aligned with high accuracy.

  When the light emitting / receiving element 5 is placed on the end surface of the multilayer substrate 10, the optical circuit board 2 and the light emitting / receiving element 5 are temporarily bonded by the bent portion 410 of the bonding sheet 41, and the bonding sheet 41 is finally cured by heating thereafter. This completes the adhesion between the two. As a result, the optical circuit 22 and the light emitting / receiving element 5 are optically connected. Since the bonding sheet 41 is a sheet having a relatively high flexibility, when the light emitting / receiving section 52 protrudes from the side surface of the light receiving / emitting element 5, the light receiving / emitting section 52 is embedded in the bonding sheet 41. It will be in the state. Thereby, the light emitting / receiving unit 52 can be reliably protected. Although the heating conditions in this case are not particularly limited, as an example, it is set to about 120 to 300 ° C. for about 1 to 120 minutes.

  The bonding sheet 41 is generally one that develops strong adhesiveness by heating, and the adhesiveness before heating is relatively weak. For this reason, after temporarily attaching / receiving the light emitting / receiving element 5 to the end face of the optical circuit board 2, it is possible to perform position adjustment such as shifting the positions of the light receiving / emitting element 5, and the position accuracy can be easily increased.

  Next, the assembly of the laminated substrate 10 and the light emitting / receiving element 5 is subjected to reflow. Thereby, the solder constituting the terminal portion 34 is melted, and the melted solder wets and spreads so as to fill a gap between the electrical connection pad 53 of the light emitting and receiving element 5 and the terminal portion 34. Thereby, the electrical connection pad 53 and the terminal portion 34 are electrically connected, and the opto-electric hybrid board 1 shown in FIG. 6K is manufactured (third step).

  Here, a gap as shown in FIG. 5J is generally generated between the electrical connection pad 53 of the light emitting and receiving element 5 and the terminal portion 34. Even if the thickness of the electrical connection pad 53 and the dimensions of the terminal portion 34 are designed in advance so that such a gap does not occur, a gap is generated between the two due to inevitable errors or thermal expansion during manufacturing. This is because it is inevitable.

  On the other hand, when the assembly of the laminated substrate 10 and the light emitting / receiving element 5 is subjected to reflow as described above, the molten solder wets and spreads on the surface of the terminal portion forming region 340 and the conductive layer end surface 341. The surface of the terminal portion formation region 340 and the conductive layer end surface 341 is made of a metal material such as copper and has high solder wettability. For this reason, this wettability serves as a driving force, so that the surfaces of the terminal portion formation region 340 and the conductive layer end surface 341 are covered with solder, and also spread in the gaps described above. As a result, regardless of the size of the gap, the gap can be filled with solder, and the electrical connection between the electrical connection pad 53 and the terminal portion 34 can be reliably performed.

  Moreover, in realizing such electrical connection, it is effective that the laminated substrate 10 and the light emitting / receiving element 5 are bonded in advance by the bent portion 410 of the bonding sheet 41 before reflow. Yes. This is because, in the assembly, the bonding sheet 41 holds the laminated substrate 10 and the light emitting / receiving element 5 in a completed state, so that this state can be maintained even during reflow. It is. As a result, the gap between the electrical connection pad 53 and the terminal portion 34 can be kept constant during reflow.

  Also, when mounting (bonding) and fixing a light emitting / receiving element on a substrate or the like, conventionally, a method of fixing only with solder (or conductive paste) has been common. However, in the case of solder, it is fluidized at the time of melting, so that the positional relationship between the light emitting / receiving element and the substrate changes, and it is difficult to maintain the position even once the alignment is performed.

  On the other hand, according to the present invention, by performing the optical connection with the bonding sheet 41, the alignment accuracy can be easily increased.

  Further, in reflow, it is only necessary that the solder wets and spreads in the gap formed between the electrical connection pad 53 and the terminal portion 34. Therefore, it is not necessary to strictly control the molten state of the solder. For this reason, regarding the reflow conditions that influence the molten state of the solder, the tolerance of the variation can be greatly relaxed, and the ease of the reflow process can be greatly improved.

  In addition, since it is not necessary to strictly control the gap generated between the electrical connection pad 53 and the terminal portion 34, the thickness of the electrical connection pad 53, the optical circuit board 2 and the electrical circuit board 3 are eliminated. , The thickness of the bonding sheet 41, and the tolerances in the variation in various manufacturing conditions such as the positional accuracy in the lamination of the optical circuit board 2 and the electric circuit board 3 can be greatly reduced.

  Thereafter, if necessary, the vicinity of the light emitting / receiving element 5 and the terminal portion 34 is covered with the mold resin 6 (see FIG. 6L). Thereby, the light emitting / receiving element 5 and the terminal portion 34 can be sealed to enhance the weather resistance and to reinforce the connection portion.

  Examples of the mold resin 6 include an epoxy resin, a polyester resin, and a polyurethane resin.

  Thereafter, if necessary, the electronic component 7 is placed on the electric circuit board 3 (see FIG. 6 (m)). Thereby, the electric circuit 32 and the electronic component 7 are electrically connected.

  Examples of the electronic component 7 include an LSI (Large Scale Integration), an IC (Integrated Circuit), a memory, a resistor, and a capacitor. These electronic components 7 may have a function of controlling driving of the light emitting / receiving element 5.

  The opto-electric hybrid board 1 as described above does not need to use an optical path conversion structure such as a mirror as described above, so that it is possible to greatly suppress optical loss during optical path conversion. Furthermore, when aligning the light emitting / receiving element 5, for example, the central axis of the core portion 224 and the center of the light receiving / emitting portion 52 may be aligned, and the alignment process can be simplified.

  Therefore, according to the opto-electric hybrid board of the present invention, a high-quality opto-electric hybrid board 1 with high optical connectivity and electrical connectivity can be obtained, and according to the method of manufacturing an opto-electric hybrid board of the present invention. Thus, the opto-electric hybrid board 1 can be manufactured efficiently.

<Another configuration example of the opto-electric hybrid board>
7 and 9 are diagrams showing other examples of the configuration of the opto-electric hybrid board shown in FIG.

  The opto-electric hybrid board 1a and 1b shown in FIGS. 7 and 9 are the same as the opto-electric hybrid board 1 shown in FIG. 2 except that the configurations of the electric circuit 32 and the terminal portion 34 are different.

  In the electric circuit board 3a provided in the opto-electric hybrid board 1a shown in FIG. 7, the electric circuit 32 is partially thicker at the left end than at the other parts (thick film). ). Specifically, the left end portion of the electric circuit 32 is partially thick so as to protrude downward, so that the end surface of the left end portion of the electric circuit 32 blocks the end surface of the support substrate 31. Has spread. As a result, the solder in the molten state can be greatly wetted and spread in the thickened portion. And in the reflow process mentioned above, the tolerance | permissible_range of the position shift of the electrical connection pad 53 and the terminal part 34 can further be eased. That is, even if the position of the pad 53 for electrical connection in the light emitting / receiving element 5 is shifted to the support substrate 31 side from the surface on which the resist layer 33 is located, only the thickness of the electrical circuit 32 is increased. Therefore, the allowable range of deviation can be relaxed. As a result, not only the dimensional accuracy restriction and the design freedom restriction of the light emitting / receiving element 5 are eased, but also solder is spread over a wider range, so that stress that tends to concentrate on the connection portion can be eased. it can.

  Here, the portion where the thickness of the electric circuit 32 shown in FIG. 7 is increased is constituted by, for example, a through wiring portion (filled via) 311 that fills the through hole 310 provided in the support substrate 31.

  Hereinafter, a method for manufacturing the opto-electric hybrid board 1a shown in FIG. 7 will be described. FIG. 8 is a diagram for explaining a method of manufacturing the opto-electric hybrid board 1a.

  First, as shown in FIG. 8A, a support substrate 31 having a through hole 310 is prepared.

  Next, as illustrated in FIG. 8B, a conductive layer in which the electric circuit 32 is formed on the upper surface of the support substrate 31 is formed so that the through hole 310 is filled with a conductive material. As a result, a through wiring portion 311 filled with a conductive material is formed in the through hole 310.

  Next, a resist layer 33 is formed so as to cover a region other than the defective portion 330 on the upper surface of the electric circuit 32.

  Next, the defect portion 330 is cut along the cutting line CL shown in FIG. 8C so as to divide the obtained through wiring portion 311.

  As shown in FIG. 8D, the conductive layer end surface 341 formed by cutting has an area that is wider than that of FIG. 2 by the thickness of the support substrate 31.

  Next, a copper erosion prevention film is formed on the terminal portion formation region 340 and the conductive layer end surface 341 by plating or the like (see FIG. 8E).

  Next, the terminal part 34 is formed by bringing the molten solder into contact with the terminal part forming region 340, whereby the electric circuit board 3a is manufactured.

  Thereafter, the opto-electric hybrid board 1a can be manufactured in the same manner as the above-described method for manufacturing the opto-electric hybrid board 1.

  Also in the manufacturing method of the opto-electric hybrid board 1a as described above, the same operation and effect as the manufacturing method of the opto-electric hybrid board 1 can be obtained.

  Moreover, in the electric circuit board 3b provided in the opto-electric hybrid board 1b shown in FIG. 9, the electric circuit 32 has a partially thicker left end than the other parts (see FIG. 9). Thicker). Specifically, the left end portion of the electric circuit 32 is partially thick so as to protrude upward. As a result, the solder in the molten state can be greatly wetted and spread over the thickened portion. As a result, in the reflow process described above, it is possible to further relax the allowable range of misalignment between the electrical connection pad 53 and the terminal portion 34. That is, even if the position of the electrical connection pad 53 in the light emitting / receiving element 5 is shifted to the opposite side of the support substrate 31 from the surface on which the resist layer 33 is located, the thickness of the electrical circuit 32 is thick. Therefore, the allowable range of deviation can be relaxed. As a result, not only the dimensional accuracy restriction and the design freedom restriction of the light emitting / receiving element 5 are eased, but also solder is spread over a wider range, so that stress that tends to concentrate on the connection portion can be eased. it can.

  Here, the portion where the thickness of the electric circuit 32 shown in FIG. 9 is increased is constituted by, for example, a bump portion 312 having a protruding shape placed on the conductive layer on which the electric circuit 32 is formed.

  Hereinafter, a method for manufacturing the opto-electric hybrid board 1b shown in FIG. 9 will be described. FIG. 10 is a diagram for explaining a method of manufacturing the opto-electric hybrid board 1b.

  First, as shown in FIG. 10A, after forming a conductive layer on which the electric circuit 32 is formed so as to cover the upper surface of the support substrate 31, a bump portion 312 is formed on a part of the upper surface of the electric circuit 32. . The bump portion 312 is a protruding member made of the same conductive material as the material forming the conductive layer, and is electrically connected to the electric circuit 32.

  Next, as illustrated in FIG. 10B, a resist layer 33 is formed so as to cover a region other than the defective portion 330 on the upper surface of the electric circuit 32.

  Next, the defect portion 330 is cut along the cutting line CL shown in FIG. 10C so as to divide the obtained bump portion 312.

  As shown in FIG. 10D, the conductive layer end surface 341 formed by cutting has an area larger than that of FIG. 2 by the thickness of the support substrate 31.

  Next, a copper erosion prevention film is formed on the terminal portion formation region 340 and the conductive layer end surface 341 by plating or the like (see FIG. 10E).

  Next, the terminal part 34 is formed by bringing the molten solder into contact with the terminal part forming region 340, whereby the electric circuit board 3b is manufactured.

  Thereafter, the opto-electric hybrid board 1b can be manufactured in the same manner as the above-described method for manufacturing the opto-electric hybrid board 1.

  Also in the manufacturing method of the opto-electric hybrid board 1b as described above, the same operation and effect as the manufacturing method of the opto-electric hybrid board 1 can be obtained.

<Another configuration example of a method for manufacturing an opto-electric hybrid board>
FIG. 11 is a diagram showing another configuration example of the method for manufacturing the opto-electric hybrid board shown in FIG.

  The manufacturing method of the opto-electric hybrid board shown in FIG. 11 differs in the order of the step of cutting the support substrate 31 and the electric circuit 32 and the step of forming the copper erosion prevention film on the terminal portion forming region 340 and the conductive layer end face 341. Except for this, the method is the same as the method for manufacturing the opto-electric hybrid board shown in FIG.

Hereinafter, a method for manufacturing the electric circuit board will be described.
First, as shown in FIG. 11A, a conductive layer on which an electric circuit 32 is formed is formed so as to cover the upper surface of the support substrate 31.

  Next, a resist layer 33 is formed so as to cover a region other than the defective portion 330 on the upper surface of the electric circuit 32.

  Next, a groove 313 is formed along the width direction of the electric circuit board (the depth direction of the paper surface of FIG. 11) at a position where the electric circuit 32 exposed to the defective portion 330 is cut thereafter (FIG. 11B). )reference). The groove 313 is preferably formed to a depth that penetrates the electric circuit 32 in the thickness direction. The formation method of the groove 313 is not particularly limited, but a method of forming a scratch on a part of the electric circuit 32 using a needle-like body or the like is used.

  Next, a copper erosion prevention film is formed on the defect portion 330 by plating or the like (see FIG. 11C). This copper erosion prevention film is formed so as to enter the groove 313 especially when formed by a plating method.

  Next, as shown in FIG. 11 (d), the defective portion 330 is cut along the center of the width of the groove 313 so as to cut the groove 313 longitudinally. By this cutting, the copper erosion prevention film formed in advance is also cut, and the terminal portion forming region 340 located in the cut portion 330 after cutting and the conductive layer end surface 341 corresponding to the inner surface of the groove 313 are formed. Each has a copper erosion prevention film on its surface (see FIG. 11E).

  According to the method as described above, the electric circuit board can be easily formed by simply forming the copper erosion prevention film after forming the groove 313 and then performing cutting.

  Here, the cross-sectional shape of the groove 313 is V-shaped, U-shaped, or the like, but the inner surface preferably satisfies the following conditions.

  First, as shown in FIG. 11B, the surface on the side to be the conductive layer end surface 341 (the right side in FIG. 11B) of the inner surface of the groove 313 is 0 with respect to the normal line of the support substrate 31. The angle is preferably about ˜20 °, more preferably about 0 ° (perpendicular to the support substrate 31). Thus, the formed conductive layer end surface 341 is substantially parallel to the connection surface of the electrical connection pad 53 of the light emitting / receiving element 5 when the light emitting / receiving element 5 is placed in the third step described above. As a result, a gap of a certain distance is formed between the conductive layer end surface 341 and the connection surface of the electrical connection pad 53. Here, since the conductive layer end surface 341 and the connection surface of the electrical connection pad 53 have high wettability of the solder, if the solder enters the gap, the connection surface of the conductive layer end surface 341 and the electrical connection pad 53 Both will drive the wetting and spreading of the solder. As a result, the solder surely wets and spreads in the gap between the conductive layer end surface 341 and the connection surface of the electrical connection pad 53, and the two are firmly and reliably connected. That is, the electrical circuit 32 and the light emitting / receiving element 5 can be reliably connected mechanically and electrically.

  On the other hand, of the inner surface of the groove 313, the angle formed between the surface opposite to the side that should be the conductive layer end surface 341 (the left side in FIG. 11B) and the normal line of the support substrate 31 is the right surface and the support surface. It is preferable that the angle formed by the normal line of the substrate 31 is larger, and specifically, an angle of about 30 to 80 ° is preferable. Accordingly, since the groove 313 has an opening having an appropriate width, the plating solution used in the plating method can surely enter the back of the groove 313. As a result, the inner surface of the groove 313 can be plated evenly, and a copper erosion prevention film can be reliably formed.

Thereafter, the opto-electric hybrid board can be manufactured in the same manner as the method shown in FIG.
In such a method for manufacturing an opto-electric hybrid board, the same operation and effect as the method shown in FIG. 3 can be obtained.

<Electronic equipment>
The electronic device including the opto-electric hybrid board of the present invention (the electronic device of the present invention) can be applied to any electronic device that performs signal processing of both an optical signal and an electric signal. For example, a router device, a WDM device, etc. Application to electronic devices such as mobile phones, game machines, personal computers, televisions, home servers, etc. is preferable. In any of these electronic devices, it is necessary to transmit a large amount of data at high speed between an arithmetic device such as an LSI and a storage device such as a RAM. Therefore, by providing such an electronic device with the opto-electric hybrid board according to the present invention, problems such as noise and signal deterioration peculiar to the electric wiring are eliminated, and a dramatic improvement in the performance can be expected.

  In addition, the amount of heat generated in the optical waveguide portion is greatly reduced compared to electrical wiring. For this reason, the degree of integration in the substrate can be increased, the power required for cooling can be reduced, and the power consumption of the entire electronic device can be reduced.

  As described above, the embodiments of the opto-electric hybrid board, the opto-electric hybrid board manufacturing method, and the electronic apparatus according to the present invention have been described. However, the present invention is not limited to this, and for example, each part constituting the opto-electric hybrid board Can be replaced with any structure capable of performing the same function. Moreover, arbitrary components may be added.

  Moreover, in the method for manufacturing an opto-electric hybrid board according to the present invention, one or two or more steps for an arbitrary purpose may be added.

  In the above-described embodiment, the optical circuit 22 (single channel) having one core part 224 has been described. However, the present invention can also be applied to an optical circuit (multi-channel) having a plurality of core parts 224. it can. In this case, the optical circuit board 2 and the light emitting / receiving element 5 are bonded so that the light emitting / receiving portions 52 are positioned corresponding to the end surfaces of the plurality of core portions 224, respectively. Also, a plurality of terminal portions 34 are provided according to the number of core portions 224, and each terminal portion 34 and the electrical connection pad 53 are electrically connected.

  Further, in this case, the light emitting / receiving element 5 may be provided with a plurality of light receiving / emitting portions 52 and a plurality of electrical connection pads 53 in one element. On the other hand, a plurality of light emitting / receiving elements 5 may be mounted.

  In the above embodiment, the case where the electrical connection pad 53 and the electrical circuit 32 are electrically connected by the terminal portion 34 made of solder or the like has been described, but the connection between the two is not limited to this method. For example, it may be performed by a method using a conductive paste, a wire bonding method, or the like.

  Among these, specific examples of the former method include a method of applying a conductive paste to the terminal portion forming region 340, a method of plating a brazing material, and the like.

  Examples of the coating method of the conductive paste include various coating methods (printing methods) such as a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, and an ink jet printing method. It is done.

  The conductive paste is a paste containing conductive metal powder (brazing material powder) and a binder component, and is fired after application to remove the binder component and bind the metal powder particles to each other. 34.

  In the above embodiment, the case where the optical circuit board 2 and the light emitting / receiving portion 52 of the light emitting / receiving element 5 are bonded together by the bonding sheet 41 has been described. You may carry out using the adhesive agent (a pressure sensitive adhesive is included) which has a light transmittance. That is, after applying an optically transparent adhesive to the end face of the laminated substrate 10 formed by laminating the electric circuit board 3 and the optical circuit board 2 or to the light emitting / receiving element 5, the lamination is performed via the applied adhesive. The substrate 10 and the light emitting / receiving element 5 may be bonded. Even in this case, the same operation and effect as in the above embodiment can be obtained. In addition to the various adhesives described above, the raw material of the bonding sheet 41 can be diverted to the adhesive as an adhesive.

DESCRIPTION OF SYMBOLS 1, 1a, 1b Opto-electric hybrid board 10 Laminated board 2 Optical circuit board 21 Support board 22 Optical circuit 221, 222 Clad layer 223 Core layer 224 Core part 225 Side clad part 3, 3a, 3b Electric circuit board 31 Support board 310 Through Hole 311 Through wiring part 312 Bump part 313 Groove 32 Electric circuit 33 Resist layer 330 Defect part 34 Terminal part 340 Terminal part formation area 341 Conductive layer end face 41 Bonding sheet 410 Bending part 5 Light emitting / receiving element 51 Package 52 Light emitting / receiving part 53 Electrical connection Pad 6 Mold resin 7 Electronic component CL Cutting line

Claims (14)

An optical circuit board having an optical circuit;
An electric circuit board laminated on the optical circuit board and having an electric circuit;
An optical-electric hybrid board comprising: an optical element for chromatic said optical circuit and a light receiver or the light emitting portion is optically connected,
Has end exposed of the optical circuit on the end face of the optical circuit board, so that the end portion of the optical circuit and the light receiving portion or the light emitting portion are opposed to each end face of the optical circuit substrate and the optical element are bonded through an adhesive having optical transparency between,
The end of the electric circuit is exposed at the end surface of the electric circuit board, and the solder spreads in the gap between the end of the electric circuit and the optical element, whereby the end of the electric circuit and the optical element And an opto-electric hybrid board.   The opto-electric hybrid board according to claim 1, wherein the adhesive is an adhesive sheet formed by forming an adhesive component into a sheet. The said end portion of said electric circuit, as a base of the solder, the light according to claim 1 or 2 base layer is formed to prevent the metal components in the electric circuit is eluted in the solder Electric mixed board. The constituent material of the electric circuit is mainly composed of Cu,
The opto-electric hybrid board according to claim 3 , wherein the constituent material of the underlayer includes at least one of Au and Ni. An optical circuit board having an optical circuit;
An electric circuit board laminated on the optical circuit board and having an electric circuit;
An optical-electric hybrid board comprising: an optical element for chromatic said optical circuit and a light receiver or the light emitting portion is optically connected,
Has end exposed of the optical circuit on the end face of the optical circuit board, so that the end portion of the optical circuit and the light receiving portion or the light emitting portion are opposed to each end face of the optical circuit substrate and the optical element are bonded through an adhesive having optical transparency between,
An end portion of the electric circuit is exposed at an end surface of the electric circuit board, and the end portion is partially thickened as compared to a portion other than the end portion of the electric circuit, and the end of the electric circuit An opto-electric hybrid board , wherein the optical element is electrically connected to the optical element . The opto-electric hybrid board according to claim 5 , wherein the thickened portion of the electric circuit is configured by a bump portion having a protruding shape. Said electric circuit board, and the electric circuit, to support the electrical circuit, which comprises a supporting substrate through hole is formed, a,
The opto-electric hybrid board according to claim 5 , wherein the thickened portion of the electric circuit is configured by a through wiring portion provided in the through hole. Electrical connection between the thickened portion and the optical element of the electrical circuit to either 5 claims have been made to seventh through the conductive material provided in these gaps The opto-electric hybrid board described. An optical circuit board having an optical circuit;
An electric circuit board laminated on the optical circuit board and having an electric circuit;
An optical-electric hybrid board comprising: an optical element for chromatic said optical circuit and a light receiver or the light emitting portion is optically connected,
Has end exposed of the optical circuit on the end face of the optical circuit board, so that the end portion of the optical circuit and the light receiving portion or the light emitting portion are opposed, the optical element on the end face of the optical circuit board Is placed,
One sheet formed by forming an adhesive component into a sheet shape between the end face of the optical circuit board and the optical element, and between the optical circuit board and the electric circuit board, and being bent in the middle. An opto-electric hybrid board , wherein at least a portion corresponding to an end face of the optical circuit board and the optical element is bonded by an adhesive sheet having light transmittance . An optical circuit board having an optical circuit;
An electric circuit board laminated on the optical circuit board and having an electric circuit;
Having said optical circuit and optically connected to light receiving unit or a light emitting unit, a method of manufacturing an optical-electric hybrid board comprising, said electrical circuit and electrically connected to the optical device,
Laminating the optical circuit board and the electric circuit board with solder attached to the end of the electric circuit, to obtain a laminate,
After attaching an adhesive to the end face of the laminate or the optical element, the end face of the laminate and the optical element are bonded via the adhesive, and the optical circuit and the light receiving part or the light emitting part are bonded. A second step of optically connecting;
A third step of electrically connecting the electrical circuit and the optical element by melting the solder and spreading the solder in a gap formed between the electrical circuit and the optical element ; A method for manufacturing an opto-electric hybrid board, comprising: The end of the electric circuit is formed so as to be exposed on the end surface of the electric circuit board,
11. The opto-electric hybrid board manufacturing method according to claim 10 , wherein an end portion of the electric circuit exposed at an end surface of the electric circuit board is formed by cutting the electric circuit board in the middle of the electric circuit. Method. The method of cutting the electric circuit board in the middle of the electric circuit, the step of forming a groove so as to penetrate the electric circuit in the thickness direction,
Forming a base layer for preventing the metal component in the electrical circuit from eluting into the solder as the solder base for the electrical circuit;
The method for manufacturing an opto-electric hybrid board according to claim 11 , further comprising a step of cutting the electric circuit board so as to cut the groove vertically. In the second step, the laminated body of the optical circuit board and the electric circuit board is disposed so as to be parallel to the vertical direction, and on the end surface of the optical circuit board facing vertically upward, by a flip chip bonder, opto-electric hybrid board manufacturing method according to any one of claims 10 to 12 disposing the optical element. An electronic apparatus comprising the electro-optic hybrid circuit board according to any one of claims 1 to 9.

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