JP2002232058A - Optical semiconductor element storage package - Google Patents

Abstract

(57) Abstract: In an optical semiconductor element housing package having a drive frequency band of 1 GHz or more, the amount of heat transmitted from a drive circuit element to an optical semiconductor element is reduced without deteriorating the transmission characteristics of a high-frequency signal. In addition, the heat generated from the optical semiconductor element and the drive circuit element is efficiently radiated to the atmosphere so that the optical semiconductor element can always be kept at an appropriate temperature and can operate normally and stably for a long period of time. SOLUTION: The base 1 of the package for housing the optical semiconductor element is provided.
The driving frequency band of the driving circuit element 7 is 1 GHz or more, the base 1 is made of a dielectric material having a thermal conductivity of 10 to 25 W / m · K, and the thickness of a portion corresponding to the mounting portion 1 a is 0.6. And the distance between the optical semiconductor element 6 and the drive circuit element 7 is 6 to 20 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor element housing package for housing an optical semiconductor element.

[0002]

2. Description of the Related Art FIG. 5 shows an optical semiconductor element housing package (hereinafter referred to as an optical semiconductor package) for housing a semiconductor laser (LD), a photodiode (PD), and the like used in a conventional optical communication field and the like. Show. In the figure, a substrate 21 has a concave portion formed in a substantially central portion of an upper surface thereof, and is made of alumina (Al ₂ O ₃ ) ceramics, aluminum nitride (A).
1N) dielectrics such as ceramics and glass ceramics,
Alternatively, it is made of a metal material such as a flat iron (Fe) -nickel (Ni) -cobalt (Co) alloy or a copper (Cu) -tungsten (W) alloy. Further, the ends of the optical semiconductor element 26 and the optical fiber 28 are provided on the bottom of the concave portion.
And a driving circuit element 27 for inputting and outputting a driving signal to and from the optical semiconductor element 26 around the concave portion around the mounting portion 21a which is attached with a low melting point brazing material such as gold (Au) -germanium (Ge) solder or the like. And a placing portion 21b for placing the.

The mounting base 25 is made of a silicon substrate or the like which is excellent in heat dissipation and workability. An optical semiconductor element 26 is mounted on the upper surface of the mounting base 25, and the end of the optical fiber 28 is positioned by passive alignment. It has a mounting portion 25a in which a groove having a substantially V-shaped cross section is formed.

The optical semiconductor element 26 and the drive circuit element 27 are attached to the mounting portions 25a and 21b by low-melting-point solder such as gold-tin (Sn) solder or tin-lead (Pb) solder. The optical semiconductor element 26 and the drive circuit element 2
The heat generated at the time of operating the base 7 is absorbed by the base 21 and the mounting base 25 via these low melting point solders and is radiated to the atmosphere.

[0005] Further, the outer periphery of the upper surface of the base 21 is surrounded by Fe so as to surround the mounting base 25 and the drive circuit element 27.
A frame body 22 made of a metal material such as a Ni-Co alloy or a Cu-W alloy and having a through hole 22a on a side is attached.

Further, a cylindrical fixing member 24 for inserting and fixing the optical fiber 28 is fixed to the periphery of the through hole 22a on the outer surface of the frame 22 or to the inner peripheral surface of the through hole 22a using a brazing material such as silver brazing. Is done.

Further, electrode pads 29 for electrically connecting the optical semiconductor package and the external electric circuit board are provided along two opposing sides of the lower surface of the base 21. As a result, the reflection loss caused when a high-frequency signal is transmitted between the optical semiconductor package and the external electric circuit board can be reduced, and the mounting deviation when mounting the optical semiconductor package on the external electric circuit board can be reduced. As a result, the input and output of the high-frequency signal into and from the optical semiconductor package are performed efficiently and smoothly. Then, the optical semiconductor package is connected to the external electric circuit board through the electrode pads 29 and the conductive paste such as a solder paste or a solder ball made of tin-lead solder or tin-silver (Ag) solder formed on the external electric circuit board. Joined.

The optical semiconductor element 2 is provided on the upper surface of the frame 22.
6 and the drive circuit element 27 are sealed with Fe-N
A cover 23 made of a metal material such as an i-Co alloy or an Fe-Ni alloy, a dielectric such as alumina ceramics, aluminum nitride ceramics, or glass ceramics, or a resin such as an epoxy resin is subjected to seam welding, brazing, or resin bonding. It is joined by an agent or the like.

The optical semiconductor element 26 and the drive circuit element 27 are hermetically housed in the optical semiconductor package to improve the operability.

As described above, the base 21, frame 22, cover 2
3 accommodates the optical semiconductor element 26 and the drive circuit element 27 inside the optical semiconductor package, and
By electrically connecting the optical semiconductor element 26 attached to the a and 21b to the drive circuit element 27 and the external electric circuit board, an optical semiconductor package that inputs and outputs a high-frequency signal to the optical semiconductor element 26 and operates. .

[0011]

However, the driving circuit element 27 accommodated in the above-mentioned conventional optical semiconductor package is not limited to the above.
In recent years, the amount of heat generated from the drive circuit element 27 when the optical semiconductor package is operated has become extremely large as compared with the related art since the density and integration have been rapidly advanced in recent years. Furthermore, miniaturization of optical semiconductor packages,
In response to the market demand for weight reduction, a drive circuit element 27 such as an LSI or an IC is mounted near the optical semiconductor element 26 and operated. As a result, the heat generated from the drive circuit element 27 is transmitted to the optical semiconductor element 26 via the base 21, the mounting base 25, and the atmosphere in the optical semiconductor package, and the optical semiconductor element 26 is heated. In addition, there has been a problem that the temperature becomes higher than a temperature at which the optical semiconductor element 26 can operate normally and stably for a long period of time.

For example, when the temperature of the optical semiconductor element 26 becomes 70 ° C. or more including its own heat generation, the function of photo-excitation is reduced. When the output of the drive circuit element 27 mounted in the vicinity of the optical semiconductor element 26 is 2 W, the vicinity is about 200
Since the temperature rises to 70 ° C., there is a problem that the optical semiconductor element 26 is heated to 70 ° C. or more by the heat of the drive circuit element 27.

As means for solving such a problem,
A configuration in which a thermoelectric cooling element such as a Peltier element or the like is installed below the mounting base 25 to cool the optical semiconductor element 26 can also be adopted, but this configuration is disadvantageous in terms of weight reduction and thickness reduction.
There is a problem that it is inferior in practical use.

Further, the thickness of the base 21 of the mounting portion 21a may be reduced to improve the thermal conductivity of the base 21, but when the base 21 is thinned, the base 21 is formed of a brazing material such as silver brazing. The distortion of the base 21 generated when attaching the base 21 to the frame 22 increases. As a result, the mounting deviation when mounting the optical semiconductor package on the external electric circuit board also increases. Therefore, transmission loss and reflection loss generated when inputting / outputting a high-frequency signal to / from the optical semiconductor package are increased, and there is a problem that input / output of the high-frequency signal in the GHz band is not performed smoothly.

Further, when the thickness of the base 21 of the mounting portion 21a is reduced, the heat diffusibility of the base 21 deteriorates, so that heat generated from the optical semiconductor element 26 and the drive circuit element 27 is stored in the base 21. However, there is a problem that heat is not efficiently released into the atmosphere.

The optical semiconductor element 26 and the drive circuit element 2
By widening the distance from the substrate 7, the amount of heat generated from the drive circuit element 27 and transmitted to the optical semiconductor element 26 via the base 21 and the mounting base 25 can be reduced. , High density in optical semiconductor package,
There has been a problem that the demands for high integration and miniaturization cannot be sufficiently satisfied, and that a transmission line for a high-frequency signal becomes long and transmission loss increases.

Further, it is possible to adopt a configuration in which the heat dissipation of the optical semiconductor package is improved by using a dielectric material having a high thermal conductivity as the base 21, but the heat generated from the drive circuit element 27 and the optical semiconductor element 26 is generated by the base 21. , Frame 22,
The light is transmitted to the entire optical semiconductor package via the lid 23. As a result, there is a problem that the optical semiconductor package itself becomes a high-temperature heat source and heats the optical semiconductor element 26 and the drive circuit element 27.

Further, as another conventional example, in order to reduce the thermal conductivity between the optical semiconductor element and the drive circuit element, a one-way heat conductive member is embedded in the base of the optical semiconductor package to reduce the thermal conductivity. There has been proposed a configuration for dividing an area in which circuit elements are mounted (Japanese Patent Laid-Open No. 2000-16).
No. 4742). However, since it is necessary to form the wiring pattern inside the optical semiconductor package so as to avoid the one-way heat conducting member, the degree of freedom of the wiring pattern is reduced and the transmission line is lengthened. As a result, transmission loss that occurs when transmitting a high-frequency signal in the GHz band increases,
The input and output of high-frequency signals between the optical semiconductor element and the drive circuit element cannot be performed efficiently and smoothly.

Accordingly, the present invention has been completed in view of the above problems, and an object of the present invention is to provide an optical semiconductor package for inputting / outputting a high frequency signal in a GHz band without deteriorating the transmission characteristics of the high frequency signal. It is an object of the present invention to reduce the size, thickness, and weight of an optical semiconductor package by improving heat dissipation in an optical semiconductor package and omitting a thermoelectric cooling element such as a Peltier element. Another object of the present invention is to effectively prevent an increase in the temperature of the optical semiconductor element by suppressing the amount of heat transmitted from the drive circuit element to the optical semiconductor element. Another object of the present invention is to effectively prevent the optical semiconductor package itself from becoming a high-temperature heat source by diffusing the heat generated from the optical semiconductor element and the drive circuit element throughout the optical semiconductor package.

[0020]

According to the optical semiconductor package of the present invention, an optical semiconductor element and an end of an optical fiber are mounted on a bottom surface of a concave portion formed at a substantially central portion of an upper surface via a mounting base. A driving circuit element for driving the optical semiconductor element, which is mounted near the optical semiconductor element in the periphery of the concave portion, and a peripheral part on the upper surface of the base. An optical semiconductor element housing package comprising: a mounting base; and a frame attached to surround the drive circuit element, wherein a lid is joined to an upper surface of the frame. The driving frequency band of the circuit element is 1 GHz or more, and the substrate has a thermal conductivity of 10 to 25 W / m · K.
Wherein the thickness of the portion corresponding to the mounting portion is 0.6 to 2 mm, and the distance between the optical semiconductor element and the drive circuit element is 6 to 20 mm.

According to the present invention, in the optical semiconductor package for inputting / outputting a high-frequency signal in the GHz band with the above configuration, the thickness of the base is designed within an optimum range, without deteriorating the transmission characteristics of the high-frequency signal. The heat dissipation inside the optical semiconductor package can be improved, and by eliminating thermoelectric cooling elements such as Peltier elements,
Enables downsizing, thinning, and weight reduction of optical semiconductor packages. In addition, by optimizing the distance between the optical semiconductor element and the drive circuit element, the amount of heat transmitted from the drive circuit element to the optical semiconductor element can be suppressed, and the temperature rise of the optical semiconductor element can be effectively prevented. Furthermore, by using a dielectric having an optimum thermal conductivity as the base, heat generated from the optical semiconductor element and the drive circuit element can be suppressed from diffusing throughout the optical semiconductor package, and the optical semiconductor package itself can be used as a high-temperature heat source. Can be effectively prevented.

In the present invention, preferably, a through-hole is formed in the base on the portion where the drive circuit element is mounted, and penetrates the upper and lower surfaces of the base, and the through-hole has a thermal conductivity of 130 W / It is characterized in that a heat conducting member of m · K or more is fitted and joined.

According to the present invention, the heat generated from the drive circuit element can be efficiently transferred to the lower surface of the optical semiconductor package via the heat conducting member and radiated to the atmosphere by the above structure. Can always be at an appropriate temperature and can effectively prevent heat transmitted from the drive circuit element to the optical semiconductor element. Therefore, the optical semiconductor element and the drive circuit element can be normally and stably operated for a long time.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The optical semiconductor package of the present invention will be described in detail below. FIG. 1 is a sectional view of an optical semiconductor package of the present invention, and FIG. 2 is a top view thereof. In these figures, 1 is a base, 2 is a frame, and 3 is a lid. The base 1, the frame 2, and the lid 3 basically constitute a container in which the optical semiconductor element 6 and a driving circuit element 7 such as an LSI or an IC for driving the optical semiconductor element 6 are housed.

The base 1 is made of a dielectric material such as alumina (Al ₂ O ₃ ) ceramic and functions as a support member for supporting the optical semiconductor element 6 and the drive circuit element 7. A mounting base 5 having a mounting portion 5a on which the ends of the optical semiconductor element 6 and the optical fiber 8 are mounted is provided on the bottom surface of the concave portion formed substantially at the center of the upper surface. It has a mounting portion 1a attached with a solder material such as Ge solder. Further, a mounting portion 1b is provided on the outer peripheral portion of the upper surface of the concave portion, which is disposed close to the optical semiconductor element 6 and on which a drive circuit element 7 for driving the optical semiconductor element 6 is mounted. The base 1 may be made of a multilayer ceramic.

On the outer peripheral portion of the upper surface of the base 1, a mounting portion 1a is provided.
A frame 2 is attached so as to surround the mounting portion 1b. Inside the frame 2, an empty space for accommodating the optical semiconductor element 6, the driving circuit element 7, and the mounting base 5 is provided. Place is formed. The frame 2 is formed into a predetermined shape by forming ceramics into a multilayer, and a through hole 2a is formed in a side portion thereof, and silver brazing or the like is interposed through a metallized layer attached to the lower surface of the frame 2. Is attached to the upper surface of the base 1 by the brazing material. The frame 2 is made of an Fe—Ni—Co alloy or Cu
-W alloy or the like, and may be made of Fe-N
It is formed by forming an ingot (lump) such as an i-Co alloy into a frame shape by press working. Further, a cylindrical fixing member 3 for fixing the optical fiber 8 around the opening on the outer surface side of the frame 2 or on the inner peripheral surface of the through hole 2a is attached to the through hole 2a.

The base 1 is formed into a paste by adding and mixing an appropriate organic binder, a solvent, and the like to the raw material powder, and forming the paste into a ceramic green sheet by a doctor blade method or a calendar roll method. The ceramic green sheet is produced by subjecting a ceramic green sheet to a suitable punching process, laminating a plurality of the sheets, and firing at a high temperature of about 1600 ° C.

The metallized layer made of tungsten (W), molybdenum (Mo), manganese (Mn), or the like, which is formed as a wiring pattern on the surface of the base 1 and the frame 2 or inside the optical semiconductor package, has A metal layer having excellent corrosion resistance and good wettability to brazing material, for example, a Ni plating layer having a thickness of 1.5 to 6 μm and an Au plating layer having a thickness of 0.2 to 5 μm are sequentially deposited on the outer surface. It is better to let it. In this case, the base 1 can be effectively prevented from being oxidized and corroded, and the mounting base 5, the frame 2, the drive circuit elements 7, and the bonding wires can be firmly attached to the base 1.

Further, on the lower surface of the base 1, electrode pads 9 for electrically connecting the optical semiconductor package and the external electric circuit board are provided along two opposing sides. The electrode pads 9 can reduce the reflection loss that occurs when transmitting a high-frequency signal between the optical semiconductor package and the external electric circuit board, as compared with the lead terminals, and mount the optical semiconductor package on the external electric circuit board. In such a case, the displacement of the mounting can be suppressed. Note that the optical semiconductor package is mounted on the external electric circuit board via a conductive paste such as a solder paste or a solder ball made of Sn-Pb solder, Sn-Ag solder or the like formed on the external electric circuit board and the electrode pad 9. Be worn.

The electrode pad 9 is formed of a metallized layer of W, Mo, Mn or the like. For example, a metal paste obtained by adding an organic solvent or a solvent to a powder of W or the like is used.
The ceramic green sheet before firing of the base 1 is formed by printing and applying a predetermined pattern on the ceramic green sheet in advance by a conventionally known screen printing method, and firing.

Further, on the surface of the electrode pad 9, a metal having excellent heat resistance and excellent wettability with the brazing material, specifically, a Ni layer having a thickness of 0.5 to 9 μm, and a metal layer having a thickness of 0.5 to 9 μm are provided. It is preferable to sequentially deposit a 5 μm Au layer, so that oxidation and corrosion of the electrode pad 9 can be effectively prevented. Further, since the optical semiconductor package can be firmly joined to the external electric circuit board via the conductor bumps, distortion of the base 1 and the mounting base 5 caused by an environmental test such as a temperature cycle test or a thermal shock test can be reduced. As a result, the deviation of the optical axis between the optical semiconductor element 6 mounted on the mounting substrate 5 and the optical fiber 8 is reduced, and the fluctuation of the optical coupling efficiency can be suppressed.
The planar shape of the electrode pad 9 is not limited to a circular shape,
The shape may be elliptical or polygonal.

In the present invention, the substrate 1 is made of a dielectric material having a thermal conductivity of 10 to 25 W / m · K. For example, when a glass ceramic having a thermal conductivity of less than 10 W / m · K is used as the base 1, heat generated from the optical semiconductor element 6 and the drive circuit element 7 can be efficiently transmitted to the lower surface of the base 1. Therefore, the heat dissipation of the optical semiconductor package is reduced.

For example, the substrate 1 has a thermal conductivity of 2
When aluminum nitride ceramics exceeding 5 W / m · K is used, heat generated from the optical semiconductor element 6 and the drive circuit element 7 is transmitted to the entire optical semiconductor package via the base 1, the frame 2, and the lid 3, The optical semiconductor package itself becomes a high-temperature heat source. As a result, the optical semiconductor element 6 and the drive circuit element 7 are heated to a temperature higher than a temperature at which the optical semiconductor element 6 and the drive circuit element 7 do not function normally and stably for a long time.

In the present invention, the thickness of the base 1 at a portion corresponding to the mounting portion 1a is 0.6 to 20 mm. If the thickness is less than 0.6 mm, the substrate 1 has reduced heat diffusivity, so that the heat generated from the optical semiconductor element 6 and the drive circuit element 7 can be efficiently absorbed and cannot be radiated into the atmosphere.
In addition, distortion of the base 1 caused when assembling the optical semiconductor package using a silver brazing material having a melting point of about 780 ° C. increases. As a result, the temperature of the optical semiconductor element 6 and the drive circuit element 7 becomes equal to or higher than a temperature at which normal and stable operation can be performed for a long period of time. In addition, the mounting deviation that occurs when the optical semiconductor package is mounted on an external electric circuit board increases, and transmission loss and reflection loss when inputting and outputting a high-frequency signal increase.

Here, when the optical semiconductor element 6 and the drive circuit element 7 are driven, the temperature of the junction between the optical semiconductor element 6 and the drive circuit element 7 and the mounting portions 5a and 1b (hereinafter, referred to as the temperature).
An example of the result of measuring the chip junction temperature) will be described. The measurement conditions were as follows. Alumina ceramics having a thermal conductivity of 15 W / m · K was used as the substrate 1, a GaAs-based semiconductor element was driven as the optical semiconductor element 6 and the drive circuit element 7, and the optical semiconductor package was cooled around. Natural cooling was performed at a temperature of 25 ° C.

First, the thickness of the mounting portion 1a of the base 1 is set to 1 m.
m, the distance between the optical semiconductor element 6 and the drive circuit element 7 is about 7 m
When the optical semiconductor element 6 and the drive circuit element 7 were operated as m, the chip junction temperature of the optical semiconductor element 6 was 69.1 ° C., and the chip junction temperature of the drive circuit element was 106.4 ° C. This is the chip junction temperature generally required for the optical semiconductor device 6 to operate normally and stably for a long period of time.
Satisfies the temperature below ℃. In addition, it satisfies a chip junction temperature of 110 ° C. or less, which is generally required for the drive circuit element 7 to operate normally and stably for a long period of time. That is, the heat generated from the optical semiconductor element 6 and the drive circuit element 7 is efficiently radiated to the atmosphere via the base, and the base 1, the mounting base 5, the optical semiconductor It has been found that heat transmitted to the optical semiconductor element 6 through the atmosphere in the package can be effectively suppressed.

Further, the thickness of the mounting portion 1b of the base 1 is set to 0.
When the optical semiconductor element 6 and the drive circuit element 7 are operated with the distance between the optical semiconductor element 6 and the drive circuit element 7 being about 7 mm, the chip junction temperature of the optical semiconductor element 6 is 69.7 ° C. and the drive circuit element The chip junction temperature of No. 7 was 114.2 ° C., and could not satisfy the condition of the chip junction temperature generally required for the drive circuit element 7 to operate normally and stably for a long period of time. That is, in the above configuration, the heat generated by the optical semiconductor element 6 and the drive circuit element 7
It was found that heat was not efficiently radiated to the atmosphere via the.

The base 1 at a position corresponding to the mounting portion 1a
When the thickness is more than 2 mm, the distortion of the base 1 generated when assembling the optical semiconductor package is reduced and the heat diffusibility of the base 1 is improved, but the optical semiconductor package is reduced in size, height and weight. Cannot fully satisfy the market requirements for Further, the transmission line of the high-frequency signal between the wiring pattern formed on the upper surface of the base 1 and the electrode pad 9 provided on the lower surface of the base 1 becomes longer, and the transmission loss increases.

The optical semiconductor element 6 and the drive circuit element 7 are mounted so that the interval is 6 to 20 mm. If the distance is smaller than 6 mm, the amount of heat transmitted from the drive circuit element 7 to the optical semiconductor element 6 via the base 1, the mounting base 5, and the atmosphere in the optical semiconductor package increases, so that the optical semiconductor element 6 The temperature rises.

When the distance between the optical semiconductor element 6 and the drive circuit element 7 is wider than 20 mm, the optical semiconductor element 6 is transferred from the drive circuit element 7 through the substrate 1, the mounting base 5, and the atmosphere in the optical semiconductor package. Although the amount of heat transmitted to 6 is suppressed, the transmission loss of the high-frequency signal between optical semiconductor element 6 and drive circuit element 7 increases because the transmission line becomes longer. In addition, the requirements for miniaturization and high integration of the optical semiconductor package cannot be sufficiently satisfied.

Further, in the optical semiconductor package of the present invention, a through hole 1c penetrating the upper and lower surfaces of the base 1 is formed in a portion corresponding to the mounting portion 1b of the drive circuit element 7, and the thermal conductivity is formed in the through hole 1c. Is a heat conducting member 1 of 130 W / m · K or more
It is good to insert and join 0. As a result, the drive circuit element 7
Heat is efficiently transmitted to the lower surface of the optical semiconductor package via the heat conducting member 10 and radiated to the atmosphere through the heat conducting member 10. Accordingly, the drive circuit element 7 always has an appropriate temperature, and heat transmitted to the optical semiconductor element 6 via the base 1 and the mounting base 5 can be effectively suppressed.

The heat conducting member 10 is made of, for example, copper (C
u)-A metal material such as a tungsten alloy or a Cu-Mo alloy. In addition, a unidirectional composite material in which carbon fibers arranged in one direction are bonded with carbon may be used.

According to the present invention, the heat generated from the optical semiconductor element 6 and the drive circuit element 7 can be efficiently radiated from the substrate 1 to the atmosphere without deteriorating the transmission characteristics of the high-frequency signal. . In addition, since a dielectric having a moderately low thermal conductivity is used as the base 1, heat generated from the optical semiconductor element 6 and the drive circuit element 7 diffuses throughout the optical semiconductor package, and the optical semiconductor package itself becomes a high-temperature heat source. Can be prevented. further,
Since the amount of heat transmitted from the drive circuit element 7 to the optical semiconductor element 6 via the substrate 1, the mounting base 5, and the atmosphere in the optical semiconductor package can be suppressed, the temperature rise of the optical semiconductor element 6 can be suppressed. . As a result, the optical semiconductor element 6 and the drive circuit element 7 can operate normally and stably for a long period of time, and the optical semiconductor package can be reduced in size and thickness by eliminating thermoelectric cooling elements such as Peltier elements. ， Enables weight reduction.

FIGS. 3 and 4 show another embodiment of the optical semiconductor package according to the present invention. These figures show radiant heat (radiant heat) emitted from the drive circuit element 7, which is one of the factors that increase the temperature of the optical semiconductor element 6.
This is a configuration for reducing the influence of the above. As shown in FIG. 3, the heat conductive member 10 at the portion where the drive circuit element 7 is mounted
Is made lower than the upper surface of the base 1, radiant heat that propagates from the drive circuit element 7 to the optical semiconductor element 6 can be effectively reduced. The height of the heat conductive member 10 where the drive circuit element 7 is placed is determined by the length of the bonding wire for electrically connecting the electrode on the upper surface of the drive circuit element 7 and the wiring pattern on the upper surface of the base 1. In order to shorten the length and reduce the transmission loss of the high-frequency signal, when the drive circuit element 7 is mounted on the upper surface of the heat conducting member 10, the upper surface of the drive circuit element 7 is flush with the upper surface of the base 1. Preferably, it is formed.

Further, as shown in FIG.
By providing the standing wall portion 1d between the driving circuit element 7 and the driving circuit element 7, radiant heat transmitted from the driving circuit element 7 to the optical semiconductor element 6 can be effectively reduced. Note that the height of the upright wall portion 1d is preferably equal to or greater than the height of the drive circuit element 7, and the length thereof is preferably equal to or greater than the length of the drive circuit element 7. With these configurations, when the optical semiconductor package operates, radiant heat that propagates from the drive circuit element 7 to the semiconductor element can be effectively reduced, and heating of the optical semiconductor element 6 can be effectively suppressed.

The fixing member 4 has a function of fixing the optical fiber 8 to the frame 2, and is attached around the outer opening of the through hole 2a of the frame 2 or on the inner peripheral surface of the through hole 2a. It is joined to the metallized layer via a brazing material such as silver brazing. Also,
The fixing member 4 is made of a metal material such as an Fe-Ni-Co alloy or a Cu-W alloy, and is formed, for example, by pressing an ingot (lump) such as an Fe-Ni-Co alloy into a tubular shape. An optical fiber 8 is inserted into the fixing member 4 and fixed with an adhesive 11 such as resin or solder, and the airtightness inside the optical semiconductor package is maintained. When a solder material is used as the adhesive, a metallization layer is previously applied to the outer peripheral surface of the joint portion of the optical fiber 8 by a conventionally known metallization method.

The upper surface of the frame 2 is, for example, Fe-
A lid 3 made of a metal material such as a Ni—Co alloy or an Fe—Ni alloy is attached, and the attachment is performed by, for example, welding using a seam welding method or the like or using a low melting point brazing material such as an Au—Sn alloy solder. It is done by attaching. Thereby, the base 1
The optical semiconductor element 6 and the drive circuit element 7 are hermetically sealed inside a container including the frame 2 and the lid 3.

Thus, in the optical semiconductor package of the present invention, the optical semiconductor element 6 and the drive circuit element 7
a. The mounting portion 1b is attached via a solder material such as Au-Sn solder or Sn-Pb solder, and is electrically connected to a wiring pattern formed inside the optical semiconductor package by a bonding wire. Thereafter, the lid 3 is placed on the upper surface of the frame 2 with Au-
The optical semiconductor element 6 and the drive circuit element 7 are attached via a low melting point brazing material such as Sn alloy solder, and housed in a container including the base 1, the frame 2, the fixing member 4, and the lid 3. Thus, an optical semiconductor device as a product is obtained.

The present invention is not limited to the above-described embodiment, and various changes may be made without departing from the scope of the present invention.

For example, by providing an electrode pad 9 on the lower surface of the heat conductive member 10 fitted into the through hole 1c, heat generated from the drive circuit element 7 can be transferred to the external electric circuit board via the heat conductive member 10 and the electrode pad 9. By transmitting to
Further, heat can be efficiently dissipated. Further, a substantially U-shaped or substantially inverted U-shaped cutout is provided on the side surface of the frame 2 without using the fixing member 4 for fixing the optical fiber 8, and the optical fiber 8 is fitted thereto, and a solder material or a resin is used. Or the like.

[0051]

According to the present invention, there is provided an optical semiconductor package having a drive frequency band of 1 GHz or more, wherein the drive circuit element has a drive frequency band of 1 GHz or more, and the substrate has a heat conductivity of 10 to 25 W / m · K. Since the thickness of the portion corresponding to the mounting portion is 0.6 to 2 mm and the distance between the optical semiconductor element and the drive circuit element is 6 to 20 mm, transmission characteristics of a high-frequency signal are reduced. Without increasing the heat dissipation of the optical semiconductor package and eliminating the need for a thermoelectric cooling element such as a Peltier element, the optical semiconductor package can be reduced in size, thickness, and weight. Further, the amount of heat transmitted from the drive circuit element to the optical semiconductor element can be suppressed, and the optical semiconductor package itself can be effectively prevented from becoming a high-temperature heat source.

Further, according to the present invention, preferably, a heat conductive member having a heat conductivity of 130 W / m · K or more is inserted into a through hole formed at a portion where the drive circuit element is mounted and penetrating the upper and lower surfaces of the base. By joining, heat generated from the drive circuit element can be efficiently transferred to the lower surface of the optical semiconductor package via the heat conducting member and radiated to the atmosphere. Accordingly, the temperature of the drive circuit element is always kept at an appropriate temperature, and heat transmitted from the drive circuit element to the optical semiconductor element can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an embodiment of an optical semiconductor package of the present invention.

FIG. 2 is a top view of the optical semiconductor package of FIG. 1;

FIG. 3 is a sectional view showing another example of the embodiment of the optical semiconductor package of FIG. 1;

FIG. 4 is a sectional view showing another example of the embodiment of the optical semiconductor package of FIG. 1;

FIG. 5 is a sectional view of an example of a conventional optical semiconductor package.

[Explanation of symbols]

 1: base 1a, 1b: mounting portion 1c: through hole 2: frame body 3: lid 5: mounting base 6: optical semiconductor element 7: drive circuit element 8: optical fiber 10: heat conductive member

Claims (2)

[Claims] A base having a mounting portion on which an optical semiconductor element and an end of an optical fiber are mounted via a mounting base on a bottom surface of a concave portion formed at a substantially central portion of an upper surface; A drive circuit element for driving the optical semiconductor element, mounted on the periphery of the optical semiconductor element in proximity to the optical semiconductor element, and surrounding the mounting base and the drive circuit element on the periphery of the upper surface of the base. And a lid attached to the upper surface of the frame, wherein the driving circuit element has a driving frequency band of 1G.
Hz or more, and the substrate has a thermal conductivity of 10 to 25 W /
a thickness of a portion corresponding to the mounting portion, which is made of a dielectric material of m · K, is 0.6 to 2 mm, and a distance between the optical semiconductor element and the drive circuit element is 6 to 20 mm. Package for storing an optical semiconductor element. 2. A through-hole penetrating the upper and lower surfaces of the base at a portion of the base on which the drive circuit element is mounted, and the through-hole has a heat conductivity of 130 W / m · K or more. 2. The conductive member is fitted and joined.
The package for storing an optical semiconductor element according to the above.