JP2003078065A - Substrate for packaging semiconductor device and package for housing optical semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that transmission characteristics are deteriorated by making characteristic impedance discontinuous and increasing the reflection of high frequency signal, since a ground potential is made unstable by the conduction resistance and impedance component of a through conductor for connecting an electrode pad and a semiconductor device in a high frequency range of >=20 GHz. SOLUTION: An interval between an electrode pad 13 and each of inner layer ground conductors 10 and 11 are defined as (d) and the diameter of the electrode pad 13 is defined as (w), in the direction parallel to the principal surface of an insulated substrate 9 configured by laminating a plurality of insulating layers 9a, 9b and 9c and an interval between the electrode pad 13 and each of inner layer ground conductors 10' and 11'. The status of 0<d<=w is provided, two of inner layer ground conductors 10, 11, 10' and 11' are laminated through the insulating layer 9b, and the thickness 14 of the insulating layer 9b between each of inner layer ground conductors 10 and 11 and each of inner layer ground conductors 10' and 11' is <=1/4 the wavelength of a high frequency signal to be transmitted by a through conductor 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor element mounting substrate for mounting a semiconductor element such as an LSI or an IC and an optical semiconductor element housing package using the same.

[0002]

2. Description of the Related Art A conventional package for storing an optical semiconductor element (hereinafter referred to as an optical semiconductor package) for storing an optical semiconductor element such as a semiconductor laser (LD), a light emitting diode (LED) or a photodiode (PD) is generally used. To iron (F
e) -Nickel (Ni) -Cobalt (Co) alloy and copper (Cu) -Tungsten (W) alloy.
This optical semiconductor package includes a base body having a mounting portion on which an optical semiconductor element is mounted at the center of the upper surface, and Fe-Ni-C.
It is made of an o alloy or the like, and is mainly composed of a frame body which is joined to the peripheral portion of the upper surface of the base body through a brazing material such as silver (Ag) brazing so as to surround the mounting portion. In this frame, a ceramic terminal made of alumina ceramics or the like and having a lead terminal for external connection is fitted into a through hole provided in a side portion thereof.

A cylindrical optical fiber fixing member (hereinafter referred to as a fixing member) made of Fe-Ni-Co alloy or the like is fitted in the through hole formed on the other side portion of the frame. This fixing member is brazed and joined to the through hole in the side portion of the frame body with Ag-Cu brazing material or the like. Further, inside the fixing member, an optical fiber for exchanging optical signals between the optical semiconductor element and the outside and a transparent member for condensing, that is, a lens member are installed.

Further, a lid for hermetically sealing the optical semiconductor element is joined to the upper surface of the frame. This lid is made of Fe-Ni
It is joined to the upper surface of the frame body by a seam welding with Ag-Cu brazing material or the like through a seal ring made of -Co alloy or the like.

In an optical semiconductor device using such an optical semiconductor package, for example, an optical semiconductor element is optically excited by a drive signal supplied from an external drive circuit or the like, and optically excited laser light or the like is transmitted. It functions as a photoelectric conversion device for optical communication that transmits and receives a large amount of information by transmitting and receiving an optical fiber through the optical member and transmitting an optical signal through the optical fiber.

In recent years, with the expansion of optical communication networks, there has been a demand for speeding up of optical communication systems, optical communication devices, the above optical semiconductor devices, and the like. Also, the optical semiconductor package is bonded to an external electric circuit board such as an external interface board,
Mounting has come to be performed on an automated line, and there is a demand for an optical semiconductor package capable of supporting such automatic mounting and capable of high-speed transmission of optical signals.

When the conventional optical semiconductor package is mounted on an external electric circuit board, it is necessary to connect and mount the lead terminals and solder connected to the lower surface of the optical semiconductor package. It is necessary to provide an electrode pad on the lower surface of the optical semiconductor package for joining the two. For this reason, the substrate of the optical semiconductor package is a multilayer ceramic substrate, and the electrode pads are firmly formed on the surface of the ceramic substrate by co-firing after applying and printing a metal paste of, for example, tungsten.

However, an electric capacitance (capacitance) is generated between this electrode pad and the inner-layer ground conductor in the base of the optical semiconductor package, and this causes a characteristic impedance of the through conductor connecting the electrode pad and the optical semiconductor element. However, there is a problem in that it is difficult to transmit and receive a high frequency signal of 1 GHz or more, which is a driving signal, with a small transmission loss.

Therefore, as a means for solving this problem, the applicant of the present invention, as shown in FIG.
Insulating substrate 109 formed by stacking a, 109b, and 109c
A semiconductor element (not shown) is mounted on one main surface, a substantially circular electrode pad 113 for external connection is provided on the other main surface, and a penetrating conductor 112 connecting the electrode pad 113 and the semiconductor element, and a penetrating conductor 112. Using the insulating substrate 109 in which the inner layer ground conductors 110 and 111 having the substantially circular opening formed so as to surround the conductor 112 are arranged, the electrode pad 113 and the inner layer ground conductors 110 and 111 in the direction parallel to the main surface are used.
And the distance d between the electrode pad 113 and the electrode pad 113 is 0 <d ≦
Semiconductor element mounting substrate 10 configured to satisfy w
1 was proposed (see Japanese Patent Laid-Open No. 2001-160598).

According to the semiconductor element mounting substrate 101, an unnecessary capacitance is generated between the inner layer ground conductors 110 and 111 in the insulating substrate 109 and the electrode pad 113, which connects the electrode pad 113 and the semiconductor element. The characteristic impedance of the through conductor 112 is set to a predetermined value (50
Ω), and as a result, it is possible to reduce the transmission loss of the drive signal composed of a high frequency signal of 1 GHz or more and to transmit and receive.

[0011]

However, recent demands for speeding up of optical transmission devices using the Internet have further increased, and there is a strong demand for speeding up in several tens of GHz band. In the substrate 101 for use, the through conductor 11 that connects the electrode pad 113 and the semiconductor element in the high frequency band of several tens GHz or more.
The ground resistance becomes unstable due to the conduction resistance and the inductance component of 2. As a result, there has been a problem that discontinuity of the characteristic impedance occurs as the frequency increases, reflection of the input signal increases, and particularly, the transmission characteristic of the high frequency signal at 20 GHz or higher deteriorates.

Therefore, the present invention has been completed in view of the above problems, and an object thereof is to have a connection structure which can be easily mounted on an external electric circuit and to reduce a transmission loss of a high frequency signal of 20 GHz or more. It is an object to provide a semiconductor element mounting substrate capable of efficient transmission and an optical semiconductor package using the same.

[0013]

A semiconductor element mounting substrate of the present invention has a mounting portion on which a semiconductor element is mounted on one main surface of an insulating substrate formed by laminating a plurality of insulating layers, and the other. A substantially circular electrode pad for external connection is provided on the main surface of
And a semiconductor element mounting substrate provided with a through conductor connecting the semiconductor element and the electrode pad inside the insulating substrate and an inner layer ground conductor having a substantially circular opening formed so as to surround the through conductor. When the distance between the electrode pad and the inner layer ground conductor in the direction parallel to the main surface is d and the diameter of the electrode pad is w, 0 <d ≦
w, and the thickness of the insulating layer between the inner layer ground conductors is one-fourth of the wavelength of the high frequency signal transmitted by the penetrating conductor. It is characterized by the following.

In the semiconductor element mounting substrate of the present invention, the distance d between the electrode pad and the inner layer ground conductor, and the diameter w of the electrode pad.
And 0 <d ≦ w, and the thickness of the insulating layer between the inner-layer ground conductors is set to 1/4 or less of the wavelength of the high-frequency signal transmitted through the through conductor, so that a high frequency of 20 GHz or higher is obtained. In a band, in a signal line composed of an electrode pad, a through conductor, and a connection pad that connects the through conductors to each other, in each insulating layer, the inner layer ground conductor or the distance between the electrode pad and the through conductor causes It is possible to effectively suppress the resonance and radiation phenomenon of electromagnetic waves generated between the two. Therefore, it is possible to prevent the characteristic impedance from changing from the predetermined value (50Ω), and as a result, it becomes possible to transmit and receive the drive signal composed of the high frequency signal with reduced transmission loss.

In the optical semiconductor package of the present invention, the semiconductor element mounting substrate of the present invention, in which the mounting portion is formed for an optical semiconductor element, and the mounting surface are surrounded by the one main surface. And a frame body having a through hole formed on its side,
A tubular optical fiber fixing member fitted in the through hole,
And a translucent member installed inside the optical fiber fixing member.

The optical semiconductor package of the present invention has the above structure and uses a high frequency signal of 20 GHz or more as a drive signal, and has electrode pads with an optical semiconductor package so that the electrode pad has a connection structure that can be easily mounted on an external electric circuit in an automation line. An optical semiconductor device provided on the lower surface can be configured, and a high frequency signal of 20 GHz or higher can be transmitted with reduced transmission loss.

[0017]

DETAILED DESCRIPTION OF THE INVENTION A semiconductor element mounting substrate (hereinafter referred to as a semiconductor element substrate) and an optical semiconductor package of the present invention will be described in detail below. And in FIG.
FIG. 2 is a cross-sectional view showing an example of an embodiment of an optical semiconductor package using the semiconductor element substrate of the present invention as a base, and FIG. 2 is an enlarged view of a main part of the semiconductor element substrate forming the optical semiconductor package of FIG. It is an expanded sectional view.

In FIGS. 1 and 2, 1 is a base made of the semiconductor element substrate of the present invention, 2 is a frame, 20 is a lid, and 3 is a light mainly composed of the base 1 and the frame 2. It is a semiconductor package. The base body 1, the frame body 2 and the lid body 20 basically constitute a container in which the optical semiconductor element 4 and the drive element 21 including an LSI, an IC and the like are housed. An optical semiconductor device is formed by joining the lid 20 to the upper surface of the frame 2.

In the base 1 of the present invention, a mounting portion for mounting the semiconductor element 4 is formed on one main surface of the insulating substrate, and the frame body 2 having the through holes 2a on its side is mounted. It is bonded to the upper surface of the base 1 so as to surround the portion 5. A cylindrical optical fiber fixing member (hereinafter referred to as a fixing member) is provided in the through hole 2a.
In this fixing member 8, an optical fiber 6 for transmitting and receiving an optical signal between the optical semiconductor element 4 and the outside and a transparent member 7 (lens member) for condensing are inserted inside. Has been fixed. Further, a lid 20 that hermetically seals the optical semiconductor element 4 is joined to the upper surface of the frame 2.

The base 1 made of the semiconductor element substrate of the present invention has a plurality of insulating layers 9a, 9b, as shown in FIG.
A mounting portion for mounting the semiconductor element 4 is formed on one main surface of an insulating substrate 9 formed by stacking 9c, and a substantially circular electrode pad 13 for external connection is provided on the other main surface. Inner layer ground conductors 10, 10 ', 1 in which a substantially circular opening is formed so as to surround the penetrating conductor 12 connecting the semiconductor element 4 and the electrode pad 13 inside the substrate 9 and the penetrating conductor 12.
1, 11 'are provided. In addition, as shown in FIG. 1, the electrode pad 13 is the electrode pad 27 of the external electric circuit board 22.
Is electrically connected via the conductor bump 23.

In the present invention, as shown in FIG. 2, the distance between the electrode pad 13 and the inner layer ground conductors 10 and 11 in the direction parallel to the main surface of the substrate 1 and the electrode pad 13 and the inner layer ground conductors 10 'and 11'. And d is the distance between the two electrodes and w is the diameter of the substantially circular electrode pad 13, the relationship 0 <d ≦ w is satisfied. That is, the distance between the inner layer ground conductor 10 and the inner layer ground conductor 11 and the distance w1 between the inner layer ground conductor 10 'and the inner layer ground conductor 11' are w <w1≤3w.

The inner layer ground conductors 10 and 11 and the inner layer ground conductors 10 ′ and 11 ′ have substantially circular openings formed so as to surround the through conductor 12. Also, FIG.
In the above, reference numeral 24 is a connection pad of the through conductor (via conductor) 12, and 25 is a signal pad for a high frequency signal.

The distance d is 0 or less, that is, in the thickness direction of the substrate 1, the electrode pad 13 and the inner layer ground conductors 10 and 11 are formed.
And the inner-layer ground conductors 10 ′ and 11 ′ overlap, an unnecessary capacitance is generated between the electrode pad 13 and the inner-layer ground conductors 10 and 11 and the inner-layer ground conductors 10 ′ and 11 ′, and the electrode pads 13 and the through conductors. 12, inner layer ground conductor 1
The characteristic impedance of the transmission line formed by 0, 11 and the inner-layer ground conductors 10 ', 11' becomes lower than a predetermined value, and the transmission loss of high frequency signals increases.

When the distance d exceeds w, the characteristic impedance increases, and the transmission loss also increases.

In the present invention, by providing a plurality of inner layer ground conductors through the insulating layer and having the above-mentioned configuration with respect to the plurality of inner layer ground conductors, unnecessary capacitance components can be effectively removed and a high frequency band exceeding 20 GHz can be obtained. Is extremely effective in suppressing transmission loss.

In the present invention, as shown in FIG. 2, the thickness 14 of the insulating layer 9b between the inner-layer ground conductors 10 and 11 and the inner-layer ground conductor layers 10 'and 11' immediately above the inner-layer ground conductors 10 and 11, that is, the inner layer. Ground conductors 10 and 11 and inner ground conductor layers 10 'and 1
The distance between 1'and 1'is less than or equal to a quarter of the wavelength of the high-frequency signal transmitted through the through conductor 12. Therefore, the specific thickness 14 is as follows depending on the frequency of the high frequency signal used. For example, 1.2 mm or less for a high frequency signal of 20 GHz, 0.8 mm or less for a 30 GHz signal, 4
0.6 mm or less in the case of 0 GHz, 0.
It is 5 mm or less and 0.4 mm or less in the case of 60 GHz.

With this configuration, in the signal line composed of the electrode pads, the through conductors, etc., it is generated between the electrode pads 13 and the through conductors 12 depending on the distance between the electrode pads 13 and the through conductors 12 between the insulating layers. Resonance and radiation phenomenon of electromagnetic waves can be suppressed. as a result,
The semiconductor element substrate has excellent transmission characteristics in a high frequency band of 20 GHz or higher.

Further, in the structure of FIG. 2, the inner layer ground conductors 10 and 11 and the inner layer ground conductor layers 10 'and 11' immediately above them.
And the thickness 14 of the insulating layer 9b are set to 1/4 or less of the wavelength of the high frequency signal, the applicable frequency band is expanded. Therefore, in the present invention, the preferable frequency range of the high frequency signal is 60 GHz or less,
When the frequency exceeds GHz, the current is concentrated on the surfaces of the electrode pad 13 and the signal pad 25 due to the skin effect of the current, and the capacitance between the electrode pad 13 and the inner-layer ground conductors 10 and 11 and the electrode pad 13 and the inner-layer ground conductor 10 '. , 11 '
The capacitance between and decreases, but signal propagation due to the magnetic field occurs, propagation of the electric field deteriorates, and transmission loss tends to increase.

The lower limit of the frequency range of the high frequency signal is not particularly limited, but 20 GHz or more is practical for high speed transmission of optical communication which meets the recent demands.

The base 1 also functions as a support member for supporting the optical semiconductor element 4. The optical semiconductor element 4 is on the upper surface.
Is mounted on the mounting portion 5, and the optical semiconductor element 4 is mounted on the mounting portion 5 via a mounting substrate 26 made of silicon or the like having good heat dissipation and workability. It is fixed by adhesion. In addition, the base 1 is composed of a plurality of insulating layers 9a, 9
The insulating substrate 9 is a multilayer ceramic substrate formed by stacking b and 9c. On the other hand, the frame body 2 may be formed by molding ceramics similarly to the base body 1, or Fe-N.
It may be made of a metal such as an i-Co alloy.

The metallized layer made of W, Mn or the like formed on the surface or inside of the substrate 1 and the frame 2 for the wiring pattern of the inner layer ground conductors 10 and 11 has excellent corrosion resistance and solder on the outer surface. A metal layer having good wettability with respect to the material, for example, a Ni plating layer having a thickness of 2 to 6 μm and a thickness of 0.
It is preferable to sequentially deposit an Au plating layer of 5 to 5 μm so that oxidative corrosion of the substrate 1 can be effectively prevented and the mounting substrate 26 disposed on the upper surface of the substrate 1 can be firmly adhered and fixed. You can

As described above, the optical semiconductor element 4 is mounted on one main surface of the base 1 made of a multilayer ceramic substrate formed by laminating a plurality of ceramic layers, and the other main surface has a substantially circular shape for external connection. The electrode pad 13 is provided. This electrode pad 1
3 is provided to reduce the transmission loss of the high frequency signal and to transmit the high frequency signal to the external electric circuit board 22 such as the external interface board, and is composed of a metallized layer such as W or Mo-Mn.

On the surface of the electrode pad 13, a metal plating layer such as a Ni plating layer and an Au plating layer, which has excellent corrosion resistance, brazing properties and wettability with a solder material, is formed.
It is preferable that the conductive bumps 23 are deposited in a thickness of 0.2 to 20 μm, and the oxidative corrosion of the conductor bumps 23 can be effectively prevented. And
The diameter of the substantially circular electrode pad 13 is preferably 0.2 to 10 mm. If the diameter is less than 0.2 mm, solder breakdown is likely to occur due to the temperature difference with the external atmosphere during manufacturing, and as a result, high frequency signal loss increases. On the other hand, when it exceeds 10 mm, the reflection loss of the high frequency signal at the conductor bump 23 becomes large, and
It is unsuitable for transmission of high frequency signals of z or higher.

When the conductor bump 23 is a protrusion or a sphere, the diameter of the electrode pad 13 may be in the above range, but when the conductor bump 23 is a lead terminal (not shown), the diameter of the electrode pad 13 is 0. 2 to 0.8 mm is preferable.

That is, the diameter of the electrode pad 13 is 0.2 mm.
If less than, the area of the electrode pad 13 connected to the main surface of the tip portion of the flat lead terminal becomes too small with respect to the main surface of the tip portion of the lead terminal. The meniscus of the brazing material is less likely to be formed, and the bonding strength of the lead terminal is likely to deteriorate.

The diameter of the electrode pad 13 is 0.8 mm.
If it exceeds, the area of the electrode pad 13 becomes large with respect to the main surface of the tip portion of the lead terminal, so that the brazing material meniscus is easily formed around the edge portion of the tip portion of the lead terminal,
Although the bonding strength of the lead terminals can be secured, the area of the electrode pad 13 unnecessarily increases, so the electrode pad 13
The reflection loss of the high frequency signal at the connection between the lead terminal and the lead terminal becomes large, which is not suitable for the transmission of the high frequency signal of 20 GHz or more.

Further, in the present invention, the electrode pad 13
Is a structure connected to the electrode pad 27 of the external electric circuit board through the conductor bump 23, a so-called BGA (Ball Grid Arra).
y) The structure is preferable. In this case, it is possible to reduce the transmission loss at the connection portion with respect to the higher frequency of the high frequency signal, and to reduce the reflection of the high frequency signal on the conductor bump 23. As a result, the connection structure can be easily mounted on the external electric circuit board 22, and the high-frequency signal can be transmitted with reduced transmission loss.

The conductor bump 23 is made of a low melting point brazing material such as Sn-Pb alloy eutectic solder or Sn-Ag alloy solder, and its size is about the same as that of the electrode pad 13. It is preferable in terms of properties and electrical characteristics. If the diameter of the conductor bumps 23 is larger than the diameter of the electrode pads 13, the pitch between them is narrowed, and problems tend to occur in terms of increased capacitance and electrical insulation.

The frame body 2 of the present invention has a through hole 2a in its side portion.
The cylindrical fixing member 8 is fitted and joined to the through hole 2a via a silver brazing material or the like. This fixing member 8 is Fe-
It is made of a metal material such as a Ni—Co alloy or an Fe—Ni alloy, and is produced, for example, by pressing an ingot (lump) of the metal material into a cylindrical shape by pressing.

The optical fiber 6 is inserted and fixed inside the cylindrical fixing member 8, and the transparent member 7 for condensing light is arranged at the end of the fixing member 8 inside the frame 2. Fiber 6
Optical signals can be exchanged between the optical semiconductor element 4 and the optical semiconductor element 4. The fixing member 8 and the optical fiber 6 are joined and fixed by solder or resin adhesive so that the inside of the optical semiconductor package 3 becomes airtight. At this time, in the case of joining with solder, it is preferable to previously form a metallized layer on the joining portion by a thin film forming method such as a sputtering method because the joining strength is improved.

A lid 20 made of a metal material such as an Fe-Ni-Co alloy or an Fe-Ni alloy is joined to the upper surface of the frame body 2, so that the base body 1, the frame body 2 and the lid body 20 are formed. The optical semiconductor element 4 is housed in the container in an airtight state. The lid 20 is joined to the upper surface of the frame 2 by a welding method such as a seam weld method.

Thus, according to the present invention, in a high frequency band of 20 GHz or more, in a signal line composed of an electrode pad, a through conductor, etc., the distance between the electrode pad and the through conductor is different between each insulating layer depending on the distance between the electrode pad and the through conductor. It is possible to suppress the resonance of the electromagnetic wave generated in 1 and the radiation phenomenon of the high frequency signal passing through the through conductor.

That is, it is possible to suppress the characteristic impedance from changing from a predetermined value (50Ω) because it can be suppressed to the extent that it does not affect the transmission property of the high frequency signal in the high frequency band used (60 GHz or less). As a result, it is possible to reduce the transmission loss of the high frequency signal flowing through the through conductor and to transmit and receive the high frequency signal between the optical semiconductor element 4 and the external electric circuit.

The present invention is not limited to the above embodiment, and various modifications may be made without departing from the scope of the present invention. For example, the fixing member 8 into which the optical fiber 6 is inserted and fixed is not limited to a tubular shape, and may have a U-shaped cross section with a groove formed on the upper surface. Further, the base 1 does not have to be a multilayer ceramic substrate, and may be, for example, a multilayer of resin layers such as polyimide. Further, although the optical semiconductor package has been mainly described in the above embodiments, the configuration of the present invention can be applied to a semiconductor element substrate and a semiconductor package for semiconductor elements such as LSI and IC.

[0045]

According to the semiconductor element substrate of the present invention, when the distance between the electrode pad and the inner layer ground conductor in the direction parallel to the main surface of the insulating substrate is d and the diameter of the electrode pad is w, 0 <d ≦.
w, and the thickness of the insulating layer between the inner-layer ground conductors is one-fourth or less of the wavelength of the high-frequency signal transmitted by the through conductors, because the inner-layer ground conductors are laminated with the insulating layer in between. , Resonance of electromagnetic wave generated between the electrode pad and the through conductor depending on the distance between the electrode pad and the through conductor between the insulating layers in the signal line composed of the electrode pad, the through conductor, and the connecting pad connecting the through conductors to each other. Also, the radiation phenomenon can be suppressed, and the characteristic impedance can be prevented from changing from a predetermined value (50Ω). As a result, particularly in a high frequency band of 20 GHz or more, it becomes possible to transmit and receive a drive signal composed of a high frequency signal with a small transmission loss.

Further, the electrode pad formed on the other main surface of the semiconductor element substrate is connected to the electrode pad of the external electric circuit board via the conductor bump, so that the external electric power is supplied via the lead terminal, the pin and the like. Compared to the case of connecting to a circuit board, the reflection of high frequency signals on the conductor bumps can be reduced, resulting in a connection structure that is easy to mount on an external electric circuit and a reduction in transmission loss of high frequency signals. Can be transmitted.

In the optical semiconductor package of the present invention, the mounting portion is attached to the semiconductor element mounting substrate of the present invention in which the mounting portion is formed for an optical semiconductor element, and the mounting portion is surrounded by one main surface, By including a frame body in which a through hole is formed in the side portion, a cylindrical optical fiber fixing member fitted in the through hole, and a translucent member installed inside the optical fiber fixing member, An optical semiconductor device that uses a high-frequency signal of 20 GHz or higher as a drive signal has a connection structure that can be easily mounted on an external electric circuit board in an automation line, and can transmit a high-frequency signal with reduced transmission loss.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an embodiment of an optical semiconductor package using a semiconductor element substrate of the present invention as a base.

2 is a partial enlarged cross-sectional view showing an enlarged main part of a semiconductor element substrate in the optical semiconductor package of FIG.

FIG. 3 is a partial enlarged cross-sectional view showing a main part of a conventional semiconductor element substrate.

[Explanation of symbols]

1: Base 2: Frame body 2a: through hole 3: Optical semiconductor package 4: Optical semiconductor element 5: Placement section 6: Optical fiber 7: Translucent member 8: Optical fiber fixing member 9: Insulating substrate 9a, 9b, 9c: insulating layer 10, 10 ', 11, 11': inner layer ground conductor 12: Through conductor 13: Electrode pad 14: Thickness of insulating layer

Claims (2)

[Claims] 1. A mounting portion on which a semiconductor element is mounted is formed on one main surface of an insulating substrate formed by laminating a plurality of insulating layers,
A substantially circular electrode pad for external connection is provided on the other main surface, and a through conductor connecting the semiconductor element and the electrode pad is provided inside the insulating substrate, and a substantially circular opening so as to surround the through conductor. A semiconductor element mounting substrate provided with an inner layer grounding conductor having a groove formed therein, wherein a distance between the electrode pad and the inner layer grounding conductor in a direction parallel to the main surface is d, and a diameter of the electrode pad is w. 0 <
d ≦ w, a plurality of the inner layer ground conductors are stacked with the insulating layer interposed therebetween, and the thickness of the insulating layer between the inner layer ground conductors is 4 minutes of the wavelength of the high frequency signal transmitted by the penetrating conductor. 1. A semiconductor element mounting substrate characterized by being 1 or less. 2. The substrate for mounting a semiconductor element according to claim 1, wherein the mounting portion is formed for an optical semiconductor element, and the one main surface is attached so as to surround the mounting portion, and a side thereof. A frame body having a through hole formed therein, a cylindrical optical fiber fixing member fitted into the through hole, and a translucent member installed inside the optical fiber fixing member. Characteristic package for optical semiconductor device storage.