JP2002231974A - Light receiving device, mounting structure thereof, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light receiving device, which has a semiconductor element mounted with a small parasitic inductance caused by mounting and has flat frequency characteristics over a wide range, and which can efficiently radiate an amplifier without disturbing an optical coupling part between an optical fiber and a light receiving element. SOLUTION: In the light receiving device which includes an optical fiber, a light receiving element for receiving an optical signal from the optical fiber, a multilayered substrate having a capacitive element built therein, and an amplifier element for amplifying a signal from the light receiving element; the light receiving element and the signal amplifier element are connected in a flip-chip connection manner as opposed to each other via the multilayered substrate, thus enabling efficient heat radiation of the amplifier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical receiver for receiving an optical signal having excellent low distortion characteristics in a wide band.

[0002]

2. Description of the Related Art In recent years, instead of communication using a metallic cable or wireless communication, optical fiber communication capable of transmitting a large amount of information with low loss has been realized.

When an image signal is received using an optical fiber, a photodiode (PD) that receives an optical signal and generates a small current corresponding to the optical signal is received at a light receiving front end portion.
A light receiving device composed of a light receiving element such as a light receiving element and an element for amplifying and demodulating the signal to a receiving sensitivity required for a television receiver or the like connected after the current after converting the minute current into a voltage is used. Can be

[0004] In the case of CATV or the like, the frequency band of a signal handled by an optical receiving apparatus for receiving such a video signal extends to a high frequency side as the number of channels increases, and is currently 1
It is about to reach GHz.

A system for distributing multi-channel video signals using optical fibers is disclosed in Japanese Patent Application No. 2000-2000.
A broadband optical receiving apparatus having a characteristic that is excellent in low distortion characteristics in a wide band described in US Pat. As shown in FIG. 18, this is a wideband amplifier 1 that amplifies an electric signal with a light receiving element 101 directly above a capacitance layer of a multilayer substrate 103 having a capacitance built in between a bias terminal 105 and a ground terminal 106.
By increasing the resonance frequency by flip-chip mounting 02, the wide band characteristics are improved and the group delay deviation is reduced.

[0006]

However, when a broadband optical signal is converted into an electric signal by a light-receiving element such as a photodiode, and the signal is amplified and demodulated, a plurality of amplifying elements are required. In particular, since the heat generation amount of the demodulation element is large and the light receiving element is arranged adjacently on the same surface, the heat sink is directly joined to the conventional structure to radiate heat from the back surface of the element having the large heat generation amount. In this case, it is necessary to join the heat sink without obstructing the optical coupling portion between the optical fiber and the light receiving element, and to secure an efficient heat conduction path.

However, when an attempt is made to join a heat sink to the amplifier in order to efficiently dissipate the heat from the amplifier, the optical coupling portion is hindered. Cannot be obtained.

Furthermore, in order to radiate heat from the substrate side, it is difficult to reduce the thermal resistance because a multilayer substrate having a built-in capacitive element is always inserted between the heat-generating amplifier and the radiator plate.

That is, there is a problem that an amplifier of an optical receiving device having excellent characteristics with low distortion in a wide band cannot be efficiently dissipated without disturbing an optical coupling portion.

The present invention has been made in consideration of the above problems, and efficiently dissipates heat from an amplifier without hindering an optical coupling portion between an optical fiber and a light receiving element. An object of the present invention is to provide an optical receiving device, a mounting structure of the optical receiving device, and a method of manufacturing the optical receiving device, which can be mounted to obtain a flat frequency characteristic in a wide band.

Further, in consideration of the above problems, the present invention can reduce the number of components when mounted on a main body substrate, and can stably manufacture with little variation in heat radiation characteristics during manufacturing. It is an object of the present invention to provide an apparatus, a method of manufacturing a mounting structure of an optical receiver, and a method of manufacturing an optical receiver.

[0012]

In order to solve the above-mentioned problems, a first invention (corresponding to claim 1) comprises an optical fiber, a light receiving element for receiving an optical signal from the optical fiber, A multi-layer substrate having a built-in capacitance element, and an amplification element for amplifying a signal of the light-receiving element, wherein the light-receiving element and the amplification element are attached to different surfaces of the multi-layer substrate, respectively, Is a light receiving device having a space around which the heat radiation member can be attached.

Further, a second aspect of the present invention (corresponding to claim 2)
Is the optical receiver according to the first aspect of the present invention, wherein the light receiving element and the amplifying element are attached to the multilayer substrate so as to overlap each other.

A third aspect of the present invention (corresponding to claim 3)
Is the optical receiving device according to the first or second aspect of the present invention, wherein the output terminal of the light receiving element and the input terminal of the signal amplifying element are attached to the multilayer substrate so as to overlap each other.

A fourth aspect of the present invention (corresponding to claim 4)
The multi-layer substrate has a peripheral terminal electrode, and the amplifying element is mounted on a surface of the multi-layer substrate on which the terminal electrode is formed. An optical receiver.

A fifth aspect of the present invention (corresponding to claim 5)
The fourth thickness of the terminal electrode is larger than a distance from a surface of the multilayer substrate on which the terminal electrode is formed to a surface of the amplifying element opposite to the surface on which the multilayer substrate is present. Is an optical receiving device according to the present invention.

The sixth invention (corresponding to claim 6)
Comprises an optical fiber, a light receiving element for receiving an optical signal from the optical fiber, a multilayer substrate having a built-in capacitance element, and an amplifier element for amplifying a signal of the light receiving element, wherein the amplifier element is the multilayer substrate The light receiving device is mounted on a main surface of the multi-layer substrate, and the light receiving device is mounted on a side surface of the multilayer substrate.

The seventh invention (corresponding to claim 7)
An optical fiber, a light receiving element for receiving an optical signal from the optical fiber, a multilayer substrate having a built-in capacitive element and having a terminal electrode around, and an amplification element for amplifying the signal of the light receiving element, The light receiving element is directly mounted on the surface of the amplification element on the side where the multilayer substrate is present, the amplification element is mounted on the multilayer substrate, and the tip of an optical fiber is the light receiving element. And there is a space around the amplifying element where a heat radiation member can be attached.

An eighth aspect of the present invention (corresponding to claim 8)
The light receiving device according to any one of the first to seventh aspects of the present invention, wherein the light receiving element is a back-illuminated photodiode.

A ninth aspect of the present invention (corresponding to claim 9)
Are the first to the first, each of which includes a plurality of chips.
An optical receiver according to any one of the sixth to sixth aspects of the present invention.

A tenth aspect of the present invention (corresponding to claim 10) is an optical receiving device according to the fourth or fifth aspect of the present invention,
An optical receiver comprising: a main body substrate connected to the terminal electrode of the multilayer substrate via a conductive electrode; and a radiator plate connected to a surface of the amplifying element opposite to a surface on which the multilayer substrate exists. This is the mounting structure of the device.

According to an eleventh aspect of the present invention (corresponding to claim 11), in the ninth aspect of the present invention, the radiator plate is connected to the surface via a resin composition having thermal conductivity. 4 is a mounting structure of the optical receiver.

A twelfth aspect of the present invention (corresponding to claim 12) is an optical receiving apparatus according to the fourth or fifth aspect,
A main body substrate facing the multi-layer substrate and connected to the terminal electrode of the multi-layer substrate, wherein a gap between the main body substrate and at least a surface of the amplifying element opposite to a side surface on which the multi-layer substrate is present is provided. 1 is a mounting structure of an optical receiver filled with a resin composition having thermal conductivity.

According to a thirteenth aspect of the present invention (corresponding to claim 13), the resin composition according to the twelfth aspect, wherein a spherical filler having a particle diameter equal to the gap between the amplifying element and the main substrate is dispersed. 4 is a mounting structure of the optical receiver according to the present invention.

A fourteenth aspect of the present invention (corresponding to claim 14) is an optical receiving device according to the fourth or fifth aspect of the present invention,
A main body substrate facing the multi-layer substrate and connected to the terminal electrodes of the multi-layer substrate, wherein a gap between the amplifying element and the multi-layer substrate and the main substrate is filled with a thermally conductive resin composition. 4 is a mounting structure of the optical receiver.

According to a fifteenth aspect of the present invention (corresponding to claim 15), the filling with the thermally conductive resin composition means that a gap between the amplifying element and the main body substrate has a first thermal conductivity. The optical receiver according to the fourteenth aspect of the present invention, wherein the optical receiving device is filled with a conductive resin composition, and a gap between the multilayer substrate and the main substrate is filled with a second heat conductive resin composition. The mounting structure.

According to a sixteenth aspect of the present invention (corresponding to claim 16), the thermal conductivity of the first thermally conductive resin composition is as follows:
The first thermal conductive resin composition has a first thermal conductivity higher than that of the second thermal conductive resin composition.
5 is a mounting structure of the optical receiver according to the fifth aspect of the present invention.

According to a seventeenth aspect of the present invention (corresponding to claim 17), the heat conductive resin composition contains inorganic particles. It is a mounting structure of the optical receiver of description.

According to an eighteenth aspect of the present invention (corresponding to claim 18), the heat conductive resin composition comprises alumina, AlN, silicon nitride, beryllia (Be) as an insulating filler.
17) A mounting structure of the optical receiver according to any one of the twelfth to sixteenth aspects of the present invention, including at least one of O).

According to a nineteenth aspect of the present invention (corresponding to claim 19), a step of mounting a light receiving element and an amplifying element on the front and back surfaces of a multilayer substrate having a built-in capacitive element, respectively, A step of sealing the space between the light-receiving element and the back surface of the multilayer substrate and the space between the amplifying element with a resin composition, and the back surface of the multilayer substrate and the main body substrate via terminal electrodes of the multilayer substrate A method for manufacturing an optical receiving device, comprising: a step of electrically connecting; and a step of filling a heat conductive resin composition between the amplifying element and the main body substrate.

According to a twentieth aspect of the present invention (corresponding to claim 20), a step of mounting a light receiving element and an amplifying element on the front and back surfaces of a multilayer substrate having a built-in capacitance element, respectively, A step of sealing the space between the light-receiving element and the space between the back surface of the multilayer substrate and the amplification element with a resin composition, and supplying the resin composition in which a filler having a uniform particle size is dispersed to the main body substrate And mounting the rear surface of the multilayer substrate and the main substrate on the main substrate while pressing the multi-layer substrate and / or the amplifying element. .

According to a twenty-first aspect of the present invention (corresponding to claim 21), the step of mounting the light receiving element on the active surface of the amplifying element, the step of processing the end surface obliquely with respect to the optical axis and forming the reflection film. Fixing the optical fiber on the multilayer substrate, performing the electrical connection while attaching the amplifying element on the multilayer substrate, and simultaneously performing the optical coupling between the light receiving element and the optical fiber; and Filling a space between an element and the multilayer substrate with a material that is transparent to signal light propagating through the optical fiber.

The present invention is configured as described above,
The amplifier can be dissipated more efficiently than before without disturbing the optical coupling portion between the optical fiber and the light receiving element.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS.

(First Embodiment) FIG. 1 is a cross-sectional view schematically showing a configuration of a high heat radiation broadband optical receiver according to a first embodiment of the present invention.

In FIG. 1, reference numeral 101 denotes a light receiving element;
Is an amplifier, 103 is a multilayer substrate, 105 is a bias terminal,
106 is a ground terminal, 107 is a bump, 108 is a via conductor, and 109 is a capacitor. Hereinafter, the optical receiver according to the first embodiment will be described with reference to FIG.

As shown in FIG. 1, a predetermined position where the terminal electrodes of the light receiving element 101 and the amplifier 102 for converting an optical input signal into an electric signal are provided and an electrode terminal on the multilayer substrate 103 are connected via bumps 107 to the element. Flip-chip mounting is performed in which the active surface is connected face-down with the substrate facing the substrate. In particular, the light receiving element 101 and the amplifying element 102 are mounted facing each other with the multilayer substrate 103 interposed therebetween.

The light receiving element 101 has one end connected to the bias terminal 10.
5, one end of the amplifier 102 is connected to the ground terminal, and the other end of the amplifier 102 is connected to the light receiving element 101.
It is connected to the. A back illuminated photodiode is used as the light receiving element, and an amplifier using a transimpedance circuit system using a gallium arsenide field effect transistor in the first stage is used as the amplifier.

The via conductor 108 is provided inside the multilayer substrate 103.
A capacitive element 109 is formed by a counter electrode connected to the bias terminal 105 and the ground terminal 106 through the capacitor.

As shown in FIG. 2A, a method of forming the capacitor element 109 inside the multilayer substrate 103 is as follows.
4 is sandwiched. As shown in FIG. 2B, holes are formed in predetermined portions by punching in advance, and the holes are filled with via conductors 108 by printing. The ceramic components are made of a mixture of borosilicate glass and alumina. A capacitor electrode 113 is formed by screen printing, and an insulating layer green sheet 112 on which an electrode pattern is printed on the surface layer and a via conductor 108 is formed from both sides thereof is laminated and fired to form a capacitor electrode 114 from both sides. A multilayer substrate in which a capacitor is formed by the counter electrode sandwiched between the capacitor electrodes 113 is obtained.

As a flip chip mounting method, for example, the following method is used. As shown in FIG. 3A, a protruding electrode made of Au or the like is formed on the terminal electrode of the light receiving element 101 by a wire bonding method or a plating method.
Next, as shown in FIG. 3B, the protruding electrodes are connected to the electrode terminals of the multilayer substrate 103 via a conductive adhesive in which flake-shaped Ag particles are dispersed. At this time, after transferring the conductive adhesive to the protruding electrodes, alignment is performed so that the conductive adhesive is in contact with the electrode terminals of the multilayer substrate 103, and the conductive adhesive is cured, so that the light-receiving element 101 and the light receiving element 101 are cured. Electrical connection with the multilayer substrate 103 is realized. Further, as shown in FIG. 3C, in order to reinforce the connection, a space formed by the light receiving element 101 and the multilayer substrate 103 is sealed with a liquid resin composition and cured. In this case, the resin composition contains an epoxy resin and a filler such as silica, and the filler is uniformly dispersed in the resin composition.

After mounting the light receiving element 101 on the multilayer substrate 103 by using the same method, the amplifier 102 is flip-chip mounted on the surface of the multilayer substrate 103 where the light receiving element 101 is not mounted.

The coupling between the optical signal from the optical fiber and the light-receiving element uses a back-illuminated photodiode as shown in FIG. 4, and the optical signal is incident on the light-receiving element from the back of the element. In the case where an optical fiber is fixed to a groove formed on a multilayer substrate to couple an optical signal and a light receiving element, an optical signal is incident on the light receiving element from the surface of the element using a surface-incident planar photodiode. A configuration is used.

On the other hand, a high heat radiation broadband optical receiver is mounted on a main body substrate as shown in FIG. The connection terminal 122 provided around the multilayer substrate 103 and the connection terminal 1 on the body substrate side
23 is electrically connected using a conductive electrode 121, and the amplifier 102 is connected to a heat sink 134 by a heat conductive resin composition 124.
Is thermally connected via the. As the conductive electrode, a chip component or the like having a low electric resistance can be used, and it can be connected using solder or the like. As the thermally conductive resin composition, a paste-like one in which a filler having a high thermal conductivity is dispersed in a resin component, a film-like one that can be deformed by pressure, and the like can be used. Further, when an amplifier using a gallium arsenide substrate having a similar thermal expansion coefficient between the amplifier and the main body substrate and a main body substrate made of alumina are used (the respective thermal expansion coefficients are 6.0 × 10 ⁻⁶ / ° C. 0.0 × 1
0 ⁻⁶ / ° C.), the connection between the amplifier and the main body substrate is made of metal such as solder, so that thermal connection reliability can be ensured and the heat radiation effect can be further enhanced.

FIG. 5 shows the relationship between the power consumption of the amplifying element and the difference between the ambient temperature and the temperature difference of the amplifying element in the mounting structure of the high heat radiation broadband optical receiver according to the present embodiment. And (b) are characteristics according to the embodiment of the present invention. As is apparent from the figure, in the embodiment of the present invention, the amplifier can be directly joined to the heat sink, so that the heat dissipation of the amplifier can be efficiently performed.

By adopting such a configuration, the heat radiation plate can be directly bonded to the back surface of the element of the amplifier without preventing the optical signal from the optical fiber from being input to the light receiving element. The heat can be dissipated efficiently, and the parasitic inductance due to the mounting can be reduced, and a flat frequency characteristic can be obtained in a wide band.

When the gap between the multilayer substrate 103 and the heat radiating plate 134 is filled with the heat conductive resin composition 124, a material having an electrically insulating property is used as the heat conductive resin composition, so that the use environment can be reduced. Since a change in characteristics due to a slight change in electrical resistance due to a change in the thermal conductive resin composition due to a change can be prevented, a highly reliable mounting structure of a high heat radiation broadband optical receiver can be obtained. .

Although the present embodiment has been described using an example in which the amplifier is composed of one element, when the amplifier is composed of a plurality of elements, the heat generation density per unit area of the amplifier is reduced, so that the efficiency is improved. Heat can be dissipated.

(Second Embodiment) FIG. 6 is a cross-sectional view schematically showing a configuration of a high heat radiation broadband optical receiver according to a second embodiment of the present invention.

In the first embodiment, the light receiving element and the amplifier are flip-chip mounted facing each other with the multi-layer substrate interposed therebetween. In the second embodiment, the light receiving element and the amplifier are mounted on the multi-layer substrate. And are flip-chip mounted facing each other so as to overlap with each other.

The predetermined positions where the terminal electrodes of the light receiving element 101 and the amplifier 102 are provided and the electrode terminals on the multilayer substrate 103 are connected via bumps 107 in a face-down state with the active surface of the element facing the substrate. So that it is flip-chip mounted.

In particular, the light receiving element 101 and the amplifying element 102 are mounted so as to face each other with the multilayer substrate 103 interposed therebetween. The light receiving element 101 has one end connected to the bias terminal 105, one end of the amplifier 102 connected to the ground terminal, and the other end of the amplifier 102 connected to the light receiving element 101. Via conductor 10 is provided inside multilayer substrate 103.
A capacitance element 109 is formed by a counter electrode connected to the bias terminal 105 and the ground terminal 106 through the capacitor 8.

With this configuration, the connection distance between the light receiving element and the amplifier and the connection distance between the capacitance element formed in the multi-layer substrate, the light receiving element and the amplifier can be shortened. , It is possible to efficiently dissipate the heat from the amplifier and obtain a flatter frequency characteristic in a wide band.

(Third Embodiment) FIG. 7 is a cross-sectional view schematically showing a configuration of a high heat radiation broadband optical receiver according to a third embodiment of the present invention.

In the second embodiment, the light receiving element and the amplifier are flip-chip mounted so as to face each other with the multilayer substrate interposed therebetween. On the other hand, in the present embodiment, the output terminal of the light receiving element is mounted. And the input terminals of the signal amplifying elements are flip-chip connected so that they overlap with each other via a multilayer substrate.

Predetermined positions where the terminal electrodes of the light receiving element 101 and the amplifier 102 are provided and the electrode terminals on the multilayer substrate 103 are connected via bumps 107 in a face-down state with the active surface of the element facing the substrate. In particular, the output terminal 131 of the light receiving element 101 is mounted.
The input terminal 132 of the amplifying element 102 and the input terminal 132 are mounted to face each other with the multilayer substrate 103 interposed therebetween, and the output terminal 131 and the input terminal 132 are connected via the via conductor 108 at the shortest distance.

With this configuration, the amplifier can be efficiently dissipated and the connection distance between the light receiving element and the amplifier can be minimized, so that a flatter frequency characteristic can be obtained in a wide band. be able to.

(Fourth Embodiment) FIG. 8 is a sectional view schematically showing a configuration of a high heat radiation broadband optical receiver according to a fourth embodiment of the present invention. In FIG. 8, 133 is a terminal electrode. FIG. 8A shows a portion of the multilayer substrate 103 and the optical fiber 104 of the high heat radiation broadband optical receiver according to the present embodiment. As shown in FIG. 8A, the light receiving element 10
A predetermined position where terminal electrodes of the first and the amplifier 102 are provided and an electrode terminal on the multilayer substrate 103 are connected via a bump 107 in a face-down state with the active surface of the element facing the substrate side. In particular, the output terminal 131 of the light receiving element 101 and the input terminal 132 of the amplifying element 102 are mounted so as to face each other with the multilayer substrate 103 interposed therebetween.

FIG. 8B shows the multi-layer substrate 103 and the main substrate 135 of the high heat radiation broadband optical receiver of this embodiment.
Part is shown. As shown in FIG. 8B, the multilayer substrate 1
03 is electrically connected to the main substrate 135 via the terminal electrode 133. At this time, the distance from the multilayer substrate 103 to the back surface of the amplifier 102 is shorter than the thickness of the terminal electrode 133.

Thus, the light receiving element 101 and the amplifier 10
2 is mounted on the main substrate via the terminal electrode 133, a gap can be provided between the back surface of the amplifier 102 and the main substrate 134, and this gap is formed by the heat conductive resin composition 124. Filling with amplifier 10
2 can efficiently dissipate heat.

When mounting is performed, solder or the like is used as a terminal electrode. When the heat conductive resin composition 124 is in a paste form in a predetermined area on the main body substrate 135, the heat conductive resin composition 124 is supplied by printing or dispensing. When the composition 124 is on a film, it can be realized by attaching a film cut into a predetermined shape and then mounting the film on a main substrate by reflow or the like.

With this configuration, it is possible to reduce the number of components when mounting on the main body substrate, and to realize a high-radiation broadband optical receiver with less variation in radiation characteristics during manufacturing.

(Fifth Embodiment) FIG. 9 is a cross-sectional view schematically showing a configuration of a high heat radiation broadband optical receiver according to a fifth embodiment of the present invention.

In the first embodiment, the light receiving element and the amplifier are flip-chip mounted so as to face each other with the multilayer substrate interposed therebetween.
In this example, the light receiving element is mounted on the side surface of the multilayer substrate, and the amplifier element is flip-chip mounted on the main surface of the multilayer substrate.

In particular, the signal output terminal of the light receiving element 101 and the signal input terminal of the amplifying element 102 are electrically connected at the shortest distance, and the power supply terminal and the ground terminal of the light receiving element 101 and the amplifying element 102 Connected to the capacitive element.

With such a configuration, the optical coupling portion between the optical fiber and the light receiving element can be three-dimensionally isolated from the amplifying element 102, so that the heat radiating plate can be directly bonded to the chip back surface of the amplifying element. Accordingly, the amplifier can be efficiently dissipated without disturbing the optical coupling portion.

When a paste-like high thermal conductive resin composition is filled between the amplifying element and the heat radiating plate in order to improve the heat radiation efficiency of the amplifier, the heat radiation is performed after applying the high thermal conductive resin composition to the back surface of the amplifier. When joining the plates, the resin composition is deformed by the pressure at the time of joining, and the spread occurs, but since the optical coupling portion and the amplifier are three-dimensionally isolated, they do not affect the optical coupling portion. It is possible to radiate heat efficiently.

(Sixth Embodiment) FIG. 10 is a sectional view schematically showing a configuration of a high heat radiation broadband optical receiver according to a sixth embodiment of the present invention.

In the first to fifth embodiments, the light receiving element and the amplifying element are electrically connected to each other through the wiring in the multilayer substrate or on the multilayer substrate.
1 shows an example in which the light receiving element is flip-chip mounted directly on the active surface of the amplifying element.

The amplifying element 102 on which the light receiving element 101 is flip-chip mounted is flip-chip mounted on the multilayer substrate 103 via the bump 107. The height of the bump 107 is mounted higher than the sum of the element thickness of the light receiving element 101 and the gap between the light receiving element 101 and the amplification element 102.
For example, when the thickness of the light receiving element is about 100 μm and the distance between the light receiving element and the amplification element is about 60 μm, the amplification element and the multi-layer substrate are connected via the bump at an interval of about 200 μm.

The bump 107 is made of solder or Au
And so on. An optical fiber 104 whose end face is obliquely processed with respect to the optical axis is mounted on the multilayer substrate 103, and a reflection film is preferably formed on the end face. Multilayer substrate 10 on which optical fiber 104 is mounted
3 is provided with a fixing groove for the optical fiber 104.
The gap between the amplifying element 102 and the multilayer substrate 103 is sealed with a resin transparent to the wavelength of light received by the light receiving element with a refractive index smaller than the refractive index of the optical fiber core. The connection reliability between the multilayer substrate 102 and the multilayer substrate 103 can be improved.

With this configuration, the heat sink can be directly bonded to the back surface of the amplifier element without preventing the optical signal from the optical fiber from being input to the light receiving element. Since the elements can be electrically connected very short, heat can be efficiently dissipated and good electrical frequency characteristics can be obtained.

(Seventh Embodiment) FIG. 11 is a sectional view schematically showing a mounting structure of a high heat radiation broadband optical receiver according to a seventh embodiment of the present invention.

In this embodiment, the light receiving element and the amplifier are flip-chip mounted on both sides of the multilayer substrate, and terminal electrodes are formed around the surface of the multilayer substrate on which the amplifier is mounted. When mounting the high heat radiation broadband optical receiver on the main body substrate, the gap between the amplification element and the main body substrate has a mounting structure filled with a thermally conductive resin composition in which a filler having a uniform particle size is dispersed. An example is shown.

The particle size of the filler is selected to be equal to or smaller than the gap between the amplifying element and the main body substrate. For example, inorganic particles are used as the filler and alumina, AlN, silicon nitride, beryllia ( By selecting at least one of BeO), the heat dissipation can be further improved. A filler having a maximum particle size of about 18 μm ± 2 μm is selected, and a filler having a small particle diameter of about 3 to 5 μm is dispersed. Improve the effect.

By adopting such a mounting structure, an optical signal can be converted into an electric signal having excellent low distortion characteristics in a wide band, and at the same time, the efficiency of the area amplifier can be improved without disturbing the optical coupling portion between the optical fiber and the light receiving element. In manufacturing the package, the spacing between the amplifier and the main board becomes uniform, and the dispersion of the heat radiation characteristics in the package of each high-radiation broadband optical receiver becomes small. Product can be manufactured stably.

(Eighth Embodiment) FIG. 12 is a sectional view schematically showing a mounting structure of a high heat radiation broadband optical receiver according to an eighth embodiment of the present invention.

In this embodiment, the light receiving element and the amplifier are flip-chip mounted on both sides of the multilayer substrate, and terminal electrodes are formed around the surface of the multilayer substrate on which the amplifier is mounted. 1 shows an example of a mounting structure mounted on a main substrate of a high heat radiation broadband optical receiver.

The multilayer substrate 103 and the main substrate 135 are electrically connected via the terminal electrode 133, and the gap between the multilayer substrate 103 and the amplifying element 102 and the main substrate 135 is filled with the heat conductive resin composition 124. Have been.

By filling all the gaps between the multilayer substrate 103 and the main substrate 135 with the heat conductive resin composition, the heat radiation from the amplifier is further effectively improved.

In this case, when an epoxy resin composition is used as the heat conductive resin composition, the connection reliability between the multilayer substrate 103 and the main substrate 135 can be improved by adhesion and curing shrinkage.

In this configuration, when a thermosetting resin having fluidity is used as the heat conductive resin composition, the light receiving element 101 and the amplifier 102 are flip-chip mounted, and are electrically connected to the main body substrate by reflow. After being connected,
This can be realized by injecting and sealing the gap between the multilayer substrate 103 and the main substrate 135 as an underfill.

With this configuration, when manufacturing the mounting structure of the high heat radiation broadband optical receiver, the heat conductive resin composition to be filled between the amplifier and the main body substrate and the multi-layer substrate and the main body substrate Since the resin composition for improving the connection reliability can be collectively formed of one kind of material, it is possible to obtain a low-cost, high-radiation, broadband optical receiver mounting structure.

(Ninth Embodiment) FIG. 13 is a sectional view schematically showing a mounting structure of a high heat radiation broadband optical receiver according to a ninth embodiment of the present invention.

In the eighth embodiment, the gap between the multi-layer substrate and the amplifying element and the main substrate is filled with a uniform resin composition. On the other hand, in the eighth embodiment, the amplifying element Resin composition 1 filled in gap between main substrate and resin composition 2 filled in gap between multilayer substrate and main substrate
3 shows an example in which a different composition is formed.

An example of such an example is a mounting structure of a high heat radiation broadband optical receiver as shown in FIG. That is, in FIG. 13A, the gap between the amplifier 102 and the main substrate 103 is filled with the resin composition 2 having higher thermal conductivity than the resin composition 1. As the resin composition 2, a thermally conductive resin composition in which a spherical filler such as alumina or aluminum nitride having high thermal conductivity is dispersed in a resin is used. Thereby, heat can be efficiently dissipated.

As still another example, there is a mounting structure of a high heat radiation broadband optical receiver as shown in FIG. That is, as shown in FIG. 13B, the gap between the amplifier 102 and the main body substrate 135 is filled with the compressible resin composition 2 and the space between the multilayer substrate 103 and the main body substrate 135 is made of epoxy or the like. It is filled with a resin composition 1 that shrinks when cured. With such a configuration, a compressive force acts between the amplifier 102 and the main body substrate 135 at the time of manufacturing, so that the compressible resin composition 2 is compressed in the completed mounting structure of the optical receiver. The filling rate of the filler dispersed in the resin composition 2 is higher than that before the compression. As a result, the thermal conductivity of the resin composition 2 in the mounting structure of the optical receiver becomes higher than that of the resin composition 2 alone, so that heat can be radiated extremely efficiently.

With this structure, the amplification element can be efficiently dissipated and the mechanical strength between the multilayer substrate and the main substrate can be increased. Can improve the electrical connection reliability.

(Tenth Embodiment) FIG. 14 is a sectional view schematically showing a method of manufacturing a high heat radiation broadband optical receiver according to a tenth embodiment of the present invention, and FIG. It is sectional drawing which shows the outline of the manufacturing method of the mounting structure of the high heat radiation broadband optical receiver in 10th Embodiment.

In this embodiment, first, as shown in FIG. 14A, paste-like eutectic solder is supplied by a printing method or the like to a predetermined region on a multilayer substrate 103 having a built-in capacitive element. After that, a spherical terminal electrode 1 is formed by coating a metal such as a ball or copper having a high-temperature solder with solder or the like.
By mounting the device 33 and performing reflow, (b) of FIG.
As shown in (1), a multilayer substrate 103 on which terminal electrodes are formed is obtained.

At this time, the size of the spherical terminal electrode 133 depends on the chip thickness of the amplifier 102, the distance between the amplifier 102 and the multilayer substrate 103 after flip-chip mounting, and the size of the main substrate 1.
A substrate having a diameter equal to the sum of the intervals between the main body substrate 103 and the amplifier 102 when mounting on the substrate 03 is selected.

Thereafter, as shown in FIG.
After positioning the amplifier 102 at a predetermined position on the side on which the terminal electrode 133 is mounted on the multilayer substrate 103, the amplifier 102 is mounted face-down, and as shown in FIG. The gap with 103 is sealed.

Subsequently, as shown in FIG. 14E, the light receiving element 101 is positioned face-to-face with the surface on which the amplifier 102 is mounted on the multilayer substrate 103, and then mounted face-down. As shown in FIG.
Similarly to the above, a gap between the multilayer substrate 103 and the light receiving element 101 is sealed to manufacture a high heat radiation broadband optical receiver.

Next, as shown in FIG. 15A, a region where the amplifier 102 and the main substrate 135 are thermally bonded on the main substrate 135 by applying the heat conductive resin composition 124 by a printing method or a dispensing method. After the alignment, the terminal electrode 133 of the high-radiation broadband optical receiver and the main substrate 135 are aligned, and the high-radiation broadband optical receiver is mounted on the main substrate 135 and subjected to a heat process such as reflow. As a result, electrical bonding between the multilayer substrate 103 and the main substrate 135 and thermal bonding between the amplifier 102 and the main substrate 135 can be performed at the same time, and a high heat radiation broadband optical receiver as shown in FIG. Can be manufactured.

By manufacturing in this manner, the gap between the amplifier 102 and the main body substrate 135 formed when mounted on the main body substrate 135 can be controlled by the size of the spherical terminal electrode 133. In this case, it is possible to provide a high-radiation broadband optical receiver that suppresses variations in the gap between the amplifier 102 and the main body substrate 135 after mounting.

(Eleventh Embodiment) FIG. 16 is a sectional view schematically showing a method of manufacturing a mounting structure of a high heat radiation broadband optical receiver according to an eleventh embodiment of the present invention.

In the tenth embodiment, the heat conductive resin composition 124 is supplied to the main substrate 135 when the high heat radiation broadband optical receiver is mounted on the main substrate 135. In the embodiment, before mounting the high heat radiation broadband optical receiver on the main body substrate 135, the heat conductive resin composition 124 in which a filler having a uniform particle size is dispersed is used.
Is supplied to the main body substrate, and then mounted on the main body substrate 135 while applying pressure to the high heat radiation broadband optical receiver.

As shown in FIG. 16A, when the high heat radiation broadband optical receiver is mounted on the main body substrate 135, the cream is provided on the main substrate 135 in the area where the terminal electrode 133 of the high heat radiation light receiver is mounted. A solder or the like is formed by printing, and then, a heat conductive resin composition 124 in which a filler having a uniform particle size is dispersed in a region where the amplifying element 102 and the main substrate 135 are opposed to each other is printed or dispensed on the main substrate 135. Supply. At this time, the particle size of the filler is selected to be equal to or smaller than the gap between the amplifying element 102 and the main body substrate 135. For example, as an inorganic insulating filler, alumina, AlN, silicon nitride, beryllia (BeO) is used as the insulating filler. At least one can be selected.

Thereafter, as shown in FIG. 16B, the high-radiation broadband optical receiver is mounted on the main body substrate 135 while applying pressure, and a heat process such as reflow is performed to form the multilayer substrate 103 and the main body substrate 135. It is electrically connected, and the gap between the amplification element 102 and the main body substrate 135 does not become smaller than the particle diameter of the filler. 12
4 is filled.

By adopting such a manufacturing method, even when warpage occurs in the multilayer substrate 103, the amplifier 102
Therefore, the mounting structure of the high heat radiation wide band optical receiver having extremely stable heat radiation characteristics can be obtained.

(Twelfth Embodiment) FIG. 17 is a sectional view schematically showing a method of manufacturing a mounting structure of a high heat radiation broadband optical receiver according to a twelfth embodiment of the present invention.

In the present embodiment, the light receiving element 101
Is an example of a manufacturing method of a mounting structure of a high heat radiation broadband optical receiver in which the amplifier 102 is flip-chip mounted directly on the active surface of the amplifier 102 and the amplifier 102 is flip-chip mounted on the multilayer substrate 103 to which the optical fiber 104 is fixed. Is shown.

First, as shown in FIG. 17A, the light receiving element 101 is directly mounted on the active surface of the amplifying element 102 by flip mounting. At this time, as the flip-chip mounting, a projecting electrode is formed on the light receiving element 101 by using, for example, a gold wire having a diameter of 18 μm by wire bonding or the like, and the projecting electrode formed on the light receiving element 101 and the electrode of the amplification element 102 are aligned. After that, a method of performing metallic bonding by ultrasonic waves, heating and pressurizing is used.

At this time, the element thickness of the light receiving element 101 is set to 1
If the one having a thickness of 00 μm is used, the distance from the back surface of the light receiving element 101 to the surface of the amplification element 102 can be formed to be 130 μm or less.

After that, as shown in FIGS. 17B and 17C, the optical fiber 104 is aligned with the multilayer substrate 103 to which the optical fiber 104 is fixed, and the light receiving element 101 is mounted on the amplifying element 102 in the same manner. The amplifying element 102 is flip-chip mounted on the multilayer substrate 103 by using the above method. At this time, the amplifying element 102 forms a metal bump higher in height than the metal bump formed when the light receiving element 101 is flip-chip mounted by the same method.

For example, a bump electrode having a height of 150 μm or more can be formed by using a gold wire having a diameter of 50 μm.
The distance between the back surface of the optical fiber 104 and the optical fiber 104 can be controlled. Further, by using a resin composition having a high transmittance for light transmitted through the optical fiber 104 between the amplifier 102 and the multilayer substrate 103, the connection with higher connection reliability can be realized.

Further, as shown in FIGS. 17C and 17D, the heat conductive resin composition 124
The amplifier 102 can be efficiently dissipated by joining the heat sink 134 via the heat sink.

With such a configuration, the amplifier 10
2 can be simultaneously mounted on the multilayer substrate 103 and the positioning of the light receiving element 101 and the optical fiber 104 can be performed at the same time, thereby simplifying the manufacturing process and manufacturing the mounting structure of the high heat radiation broadband optical receiver at low cost. Can be.

[0109]

As is apparent from the above description, the present invention provides an optical receiving apparatus and an optical receiving apparatus capable of efficiently dissipating heat from an amplifier without hindering an optical coupling portion between an optical fiber and a light receiving element. And a method of manufacturing the optical receiving device can be provided.

Further, the present invention provides an optical receiving device, a mounting structure of an optical receiving device, and an optical receiving device capable of mounting a semiconductor element with a small parasitic inductance due to mounting and obtaining a flat frequency characteristic in a wide band. Can be provided.

Further, according to the present invention, an optical receiving device which can reduce the number of components when mounted on a main body substrate and can stably manufacture an optical receiving device with less variation in heat radiation characteristics during manufacturing. The mounting structure of the optical receiver and the method for manufacturing the optical receiver can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an optical receiving device according to a first embodiment of the present invention.

FIG. 2A shows a configuration before laminating an insulating layer green sheet on which a capacitor layer used in forming a capacitive element in a multilayer substrate according to a first embodiment of the present invention is formed. FIG. FIG. 2B is a diagram illustrating a multilayer substrate in which the capacitive element according to the first embodiment of the present invention is formed inside the multilayer substrate.

FIG. 3A is a cross-sectional view illustrating a step of forming a protruding electrode on the light receiving element in the step of mounting the light receiving element on the multilayer substrate according to the first embodiment of the present invention. FIG. 4B is a cross-sectional view illustrating a step of mounting the light receiving element on the multilayer substrate in the step of mounting the light receiving element on the multilayer substrate according to the first embodiment of the present invention. FIG. 3C is a cross-sectional view illustrating a step of sealing the light receiving element mounted on the multilayer substrate with a resin composition in the step of mounting the light receiving element on the multilayer substrate according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a schematic configuration of a mounting structure of the high heat radiation broadband optical receiver according to the first embodiment of the present invention.

FIG. 5 is a graph showing heat radiation characteristics of the mounting structure of the high heat radiation broadband optical receiver according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a schematic configuration of a high heat radiation broadband optical receiver according to a second embodiment of the present invention.

FIG. 7 is a schematic configuration of a high heat radiation broadband optical receiver according to a third embodiment of the present invention.

FIG. 8A is a schematic diagram of a high heat radiation broadband optical receiver according to a fourth embodiment of the present invention. (B) It is sectional drawing which shows the mounting structure to the main-body board | substrate of the high heat radiation broadband optical receiver in 4th Embodiment of this invention.

FIG. 9 is a cross-sectional view illustrating a schematic configuration of a high heat radiation broadband optical receiver according to a fifth embodiment of the present invention.

FIG. 10 is a cross-sectional view illustrating a schematic configuration of a high heat radiation broadband optical receiver according to a sixth embodiment of the present invention.

FIG. 11 is a cross-sectional view schematically illustrating a mounting structure of a high heat radiation broadband optical receiver according to a seventh embodiment of the present invention.

FIG. 12 is a cross-sectional view schematically illustrating a mounting structure of a high heat radiation broadband optical receiver according to an eighth embodiment of the present invention.

FIG. 13 (a) A resin composition 1 filled in a gap between an amplifying element and a main substrate and a resin composition 2 filled in a gap between a multilayer substrate and a main substrate in a ninth embodiment of the present invention.
FIG. 4 is a cross-sectional view schematically showing a mounting structure of a high heat radiation broadband optical receiver formed of a composition different from that of FIG. (B) A resin composition 1 filled in the gap between the amplification element and the main substrate and a resin composition 2 filled in the gap between the multilayer substrate and the main substrate according to the ninth embodiment of the present invention are different. It is sectional drawing which shows the outline of the mounting structure of another high heat radiation broadband optical receiver formed by (1).

FIG. 14 (a) shows a multilayer substrate 1 in a manufacturing process of a high heat radiation broadband optical receiver according to a tenth embodiment of the present invention.
FIG. 13 is a cross-sectional view showing a step of mounting a terminal electrode 133 in a predetermined area on a surface 03. (B) It is sectional drawing which shows the process of forming the terminal electrode 133 in the multilayer substrate 103 among the manufacturing processes of the high heat radiation broadband optical receiver in 10th Embodiment of this invention. (C) In the manufacturing process of the high heat radiation broadband optical receiver according to the tenth embodiment of the present invention, the amplifier 10
FIG. 9 is a cross-sectional view showing a step of mounting face-down after positioning No. 2; (D) It is sectional drawing which shows the process of sealing the clearance gap between the amplifier 102 and the multilayer substrate 103 by underfill in the manufacturing process of the high heat radiation broadband optical receiver in 10th Embodiment of this invention. (E) In the manufacturing process of the high heat radiation broadband optical receiver according to the tenth embodiment of the present invention, after aligning the light receiving element 101 with the surface of the multilayer substrate 103 opposite to the surface on which the amplifier 102 is mounted. It is sectional drawing which shows the process of mounting by face-down. (F) is a cross-sectional view showing a step of sealing a gap between the multilayer substrate 103 and the light receiving element 101 in the same manner as the amplifier 102, in the manufacturing steps of the high heat radiation broadband optical receiver according to the tenth embodiment of the present invention. is there.

FIG. 15 (a) shows a manufacturing process of a mounting structure of a high heat radiation broadband optical receiver according to a tenth embodiment of the present invention;
FIG. 9 is a cross-sectional view showing a step of supplying a thermally conductive resin composition 124 to a predetermined region on the main substrate 135 facing the amplification element 102. (B) The terminal electrode 1 in the manufacturing process of the mounting structure of the high heat radiation broadband optical receiver according to the tenth embodiment of the present invention.
FIG. 13 is a cross-sectional view showing a step of mounting the high heat radiation broadband optical receiver on the main body substrate 135 by reflowing the multilayer substrate 103 on which the substrate 33 is mounted.

FIG. 16A shows a step of manufacturing a mounting structure of a high heat radiation broadband optical receiver according to an eleventh embodiment of the present invention;
Terminal electrode 133 of high heat radiation light receiving device on main body substrate 135
Is formed, and then the heat conductive resin composition 124 is applied to the region where the amplification element 102 and the main body substrate 135 face each other.
It is sectional drawing which shows the process of supplying to 35. (B) In the manufacturing process of the mounting structure of the high-radiation broadband optical receiver according to the eleventh embodiment of the present invention, the high-radiation broadband optical receiver is mounted on the main body substrate 135 while pressing,
It is sectional drawing which shows the process of performing a thermal process, such as reflow.

FIG. 17 (a) shows a manufacturing process of a mounting structure of a high heat radiation broadband optical receiver according to a twelfth embodiment of the present invention;
FIG. 9 is a cross-sectional view showing a step of flip-mounting the light receiving element 101 directly on the active surface of the amplification element 102. (B) In the manufacturing process of the mounting structure of the high heat radiation broadband optical receiver according to the twelfth embodiment of the present invention, the amplifying element 102 on which the light receiving element 101 is mounted in the step (a) and the bump 107 is formed in the step (a). FIG. (C) In the manufacturing process of the mounting structure of the high heat radiation broadband optical receiver according to the twelfth embodiment of the present invention, the amplifier element 102 is aligned with the multilayer substrate 103 to which the optical fiber 104 is fixed, and FIG. 10 is a cross-sectional view showing a step of flip-chip mounting on the semiconductor device 103. (D) The amplifier 10 in the manufacturing process of the mounting structure of the high heat radiation broadband optical receiver according to the twelfth embodiment of the present invention.
2 on the back surface of the heat sink 1 via the heat conductive resin composition 124
It is sectional drawing which shows the process of joining 34. (E) It is sectional drawing which shows the high heat radiation wide band optical receiver which completed the process of (d) among the manufacturing processes of the mounting structure of the high heat radiation wide band optical receiver in the 12th Embodiment of this invention.

FIG. 18 is a cross-sectional view illustrating a schematic configuration of a conventional broadband optical receiver.

[Explanation of symbols]

 Reference Signs List 101 light receiving element 102 amplifier 103 multilayer substrate 104 optical fiber 105 bias terminal 106 ground terminal 107 bump 108 via conductor 109 capacitance element 112 green sheet 113 capacitor electrode 114 capacitor layer 121 conductive electrode 122 connection terminal 123 body terminal side connection terminal 124 Thermal conductive resin composition 131 Output terminal 132 Input terminal 133 Terminal electrode 134 Heat sink 135 Body board

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yutaka Taguchi 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Minehiro 1006 Kadoma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. F term (reference) 4M109 AA01 BA03 CA05 DB02 EB12 EC06 GA01 GA05 4M118 AA10 AB05 CA02 GA02 HA20 HA22 HA23 HA24 HA31 5F088 AA01 BA16 BB01 EA07 JA03 JA09 JA14 JA20

Claims (21)

[Claims] An optical fiber, a light receiving element for receiving an optical signal from the optical fiber, a multilayer substrate having a built-in capacitance element, and an amplifying element for amplifying a signal from the light receiving element. The optical receiver, wherein the amplifying elements are attached to different surfaces of the multilayer substrate, respectively, and there is a space around the amplifying element where a heat radiation member can be attached. 2. The optical receiving device according to claim 1, wherein said light receiving element and said amplifying element are respectively mounted on said multilayer substrate so as to overlap each other. 3. The optical receiver according to claim 1, wherein an output terminal of the light receiving element and an input terminal of the signal amplifying element are attached to the multilayer substrate so as to overlap each other. 4. The multi-layer substrate according to claim 1, wherein the multi-layer substrate has a terminal electrode on a periphery thereof, and the amplification element is mounted on a surface of the multi-layer substrate on which the terminal electrode is formed. Optical receiver. 5. The thickness of the terminal electrode is determined by a distance from a surface of the multilayer substrate on which the terminal electrode is formed to a surface of the amplifying element opposite to a surface on which the multilayer substrate is present. The optical receiving device according to claim 4, which is large. 6. An optical fiber, comprising: a light receiving element for receiving an optical signal from the optical fiber; a multilayer substrate having a built-in capacitance element; and an amplifying element for amplifying a signal of the light receiving element. An optical receiving device attached to a main surface of the multilayer substrate, the light receiving element is attached to a side surface of the multilayer substrate, and a space around the amplifying element where a heat radiation member can be attached exists. 7. An optical fiber, a light receiving element for receiving an optical signal from the optical fiber, a multilayer substrate having a built-in capacitance element and having a terminal electrode around it, and an amplifying element for amplifying a signal of the light receiving element Wherein the light receiving element is directly mounted on the surface of the amplification element on the side where the multilayer substrate is present, the amplification element is mounted on the multilayer substrate, and the tip of the optical fiber is An optical receiving device which is in contact with the light receiving element and has a space around the amplification element to which a heat radiation member can be attached. 8. The optical receiver according to claim 1, wherein said light receiving element is a back-illuminated photodiode. 9. The optical receiving device according to claim 1, wherein said amplifying element is constituted by a plurality of chips. 10. The optical receiving device according to claim 4 or 5, a main substrate connected to the terminal electrode of the multilayer substrate via a conductive electrode, and a surface of the amplification element on which the multilayer substrate exists. And a heat sink connected to a surface on the opposite side of the optical receiver. 11. The mounting structure for an optical receiver according to claim 9, wherein said heat sink is connected to said surface via a resin composition having thermal conductivity. 12. The optical receiving device according to claim 4, further comprising: a main body substrate facing the multilayer substrate and connected to the terminal electrode of the multilayer substrate, wherein at least the multilayer substrate of the amplifying element is provided. The mounting structure of the optical receiving device, wherein a gap between the surface opposite to the side surface on which the surface exists and the main body substrate is filled with a resin composition having thermal conductivity. 13. The mounting structure of an optical receiver according to claim 12, wherein the resin composition has a spherical filler having a particle diameter equal to a gap between the amplifying element and the main substrate dispersed therein. 14. The optical receiving device according to claim 4, further comprising: a main body substrate facing the multilayer substrate and connected to the terminal electrode of the multilayer substrate, wherein the amplifying element and the multilayer substrate And a mounting structure of the optical receiver in which a gap with the main substrate is filled with a thermally conductive resin composition. 15. The term “filled with the thermally conductive resin composition” means that a gap between the amplifying element and the main body substrate is the first.
15. The optical receiving device according to claim 14, wherein the gap between the multilayer substrate and the main body substrate is filled with a second heat conductive resin composition. Mounting structure. 16. The mounting structure for an optical receiver according to claim 15, wherein the thermal conductivity of the first thermal conductive resin composition is higher than the thermal conductivity of the second thermal conductive resin composition. 17. The mounting structure for an optical receiver according to claim 12, wherein the heat conductive resin composition includes inorganic particles. 18. The optical receiver according to claim 12, wherein the thermally conductive resin composition contains at least one of alumina, AlN, silicon nitride, and beryllia (BeO) as an insulating filler. Mounting structure. 19. A step of mounting a light receiving element and an amplifying element respectively on a front surface and a back surface of a multilayer substrate having a built-in capacitance element; A step of sealing the space between the multi-layer substrate and the amplifying element with a resin composition; a step of electrically connecting the back surface of the multilayer substrate and the main substrate via terminal electrodes of the multilayer substrate; Filling the space between the amplifying element and the main body substrate. 20. A step of mounting a light receiving element and an amplifying element respectively on a front surface and a back surface of a multilayer substrate having a built-in capacitance element; A step of sealing the space between the multi-layer substrate and the amplification element with a resin composition, a step of supplying a resin composition in which a filler having a uniform particle size is dispersed to the main substrate, Mounting the multi-layer substrate and / or the amplifying element on the main body substrate while applying pressure to the main body substrate. 21. A step of mounting a light receiving element on an active surface of an amplifying element; a step of fixing an optical fiber having an end face processed obliquely to an optical axis and having a reflective film formed thereon, on a multilayer substrate; Attaching an amplifying element on the multilayer substrate to perform electrical connection while simultaneously performing optical coupling between the light receiving element and the optical fiber; and a signal propagating through the optical fiber between the amplifying element and the multilayer substrate. Filling with a material transparent to light.