JP2002305262A - Package for packaging semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package for packaging a semiconductor device, that matches the impedance between a semiconductor device and a wiring board, reduces signal loss at the connection point between the semiconductor device and wiring board, and at the same, time can be packaged finely and accurately. SOLUTION: The package for packaging a semiconductor device has a frame 1, that has an opening 11 at the upper section, a hollow section 12, and a glass coaxial bead 5 on the sidewall, a wiring board 3 that is accommodated in the frame 1, is made of a semiconductor, and is mechanically and electrically connected to the glass coaxial bead 5, the semiconductor device 2 that is accommodated in the frame 1, and a cap 4 that covers the opening 11. In the package for packaging a semiconductor device, an electrode terminal, provided on the lower surface of the semiconductor device 2, is connected to an electrode terminal provided on the upper surface of the wiring board 3 by bump bonding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a package for mounting a semiconductor element.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view showing the structure of a conventional example of a package for mounting a semiconductor element.

[0003] 1 is a frame, 11 is an opening at the top of the frame 1, 12 is a hollow portion of the frame 1, 13 is a frame 1
2, a semiconductor element, 21 is a wiring on the semiconductor element 2, 3 is a wiring board, 31 is a planar waveguide wiring on the wiring board 3, 32 is a cavity (hole) provided in the center of the wiring board 3, 4 is a seal cap, 5 is a high-frequency glass coaxial bead, 51 is a center conductor of the glass coaxial bead 5, 52 is a dielectric of the glass coaxial bead 5, and 10 is a bonding wire.

[0004] In this conventional semiconductor device mounting package, a metal housing is used as the frame 1.
On the side wall of the metal frame 1, a coaxial terminal which is a component of the high-frequency coaxial connector, that is, a glass coaxial bead 5 is provided. After mounting the semiconductor element 2,
Airtightness is ensured by connecting the seal cap 4 to the upper surface of the frame 1 by means such as seam welding, brazing, or bonding. Inside the frame 1, a semiconductor element 2
A wiring substrate 3 provided with a cavity 32 for mounting the center is disposed, and a planar waveguide wiring 31 such as a microstrip or a grounded coplanar is disposed on the wiring substrate 3. Planar waveguide wiring 31 on wiring substrate 3
And the central conductor 51 of the coaxial bead 5 are electrically and mechanically connected by solder, silver paste, or the like.

[0005]

In this package for mounting a semiconductor element, a bonding wire 10 or a bonding ribbon is used to connect the wiring 21 on the semiconductor element 2 and the planar waveguide wiring 31 on the wiring board 3. Had been. For this reason, impedance mismatch occurs at the bonding portion of the bonding wire 10 or the bonding ribbon, and the reflection loss and the insertion loss of the signal at the bonding portion are large. Therefore, in order to mount a high-frequency semiconductor element of a quasi-millimeter-wave band or higher, the level difference between the semiconductor element 2 and the wiring board 3 must be reduced to within several tens of μm in order to minimize reflection loss and insertion loss of this signal. A great deal of labor was required, such as reducing the length of the bonding wire 10 or the bonding ribbon to several hundred μm.

As described above, in the prior art, the wiring 21 on the semiconductor element 2 and the planar waveguide wiring 31 on the wiring board 3 are used.
Since the bonding wire 10 or the bonding ribbon is used for connection with the semiconductor, the reflection loss and insertion loss of the signal are usually large, and the frequency band used is limited to a quasi-millimeter wave band or less, and a semiconductor having a higher frequency performance than that. When the element 2 is mounted, there is a problem that its performance cannot be sufficiently brought out due to impedance mismatch of the bonding portion of the bonding wire 10 or the bonding ribbon.

Further, since the wiring board 3 is made of ceramic or glass ceramic provided with printed wiring, it can be mounted on a fine structure required in a high frequency band of quasi-millimeter wave or millimeter wave or higher, and high positioning accuracy can be obtained. Implementation was difficult.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, achieve impedance matching between a semiconductor element and a wiring board, reduce a signal loss at a connection point between the two, and realize a fine and highly accurate semiconductor element. To provide a package for mounting.

[0009]

In order to solve the above problems, a package for mounting a semiconductor device according to the present invention has an opening at an upper portion, a hollow portion, and at least one coaxial terminal on a side wall. A frame having, a wiring board housed inside the frame, made of semiconductor, mechanically and electrically connected to the coaxial terminal, a semiconductor element housed inside the frame, and a cap covering the opening. Wherein the electrode terminals provided on the lower surface of the semiconductor element and the electrode terminals provided on the upper surface of the wiring board are connected by bump bonding.

In the present invention, the wiring board is made of a semiconductor,
A planar waveguide wiring such as a microstrip or grounded coplanar formed on the wiring board and a center conductor of a coaxial terminal provided on the package frame are electrically connected by solder, silver paste, or the like; Since the semiconductor element and the wiring board are electrically connected directly by bump bonding, impedance mismatch is sufficiently suppressed inside the package, and signal loss at a connection point between the two is reduced.

In addition, by using a semiconductor substrate for the wiring substrate, the semiconductor substrate can be manufactured using a high-precision semiconductor process, and can be mounted with high accuracy. Even when a semiconductor element having the same is mounted, its performance can be sufficiently brought out. Further, since the stress caused by the difference in linear expansion coefficient between the semiconductor element and the wiring board made of the semiconductor can be reduced, the reliability of the connection portion between the two is improved, and a high-precision semiconductor capable of coping with an ultra-high frequency element is provided. An element mounting package can be realized.

Further, the wiring board is made of gallium arsenide, and the frame is made of Kovar. As described above, by selecting a material having a close linear expansion coefficient as the material of the wiring board and the frame, the thermal stress generated inside the package can be reduced.

Further, an elastic buffer layer is inserted between the lower surface of the wiring board and the inner surface of the frame. By inserting such a buffer layer,
Thermal stress generated inside the package can be further reduced.

Further, the coaxial terminal is provided so as to pass through a through hole provided in a side wall of the frame, and an elastic buffer layer is provided between the through hole and the coaxial terminal. As described above, by inserting the elastic buffer layer into the through hole for attaching the coaxial terminal, the stress applied to the mechanical / electrical connection between the central conductor of the coaxial terminal and the wiring board can be reduced.

Further, a heat radiating member is provided between the inner surface of the cap and the upper surface of the semiconductor element, and between the heat radiating member and the semiconductor element, or between the inner surface of the cap and the heat radiating member. It is characterized in that an elastic buffer layer is inserted. By inserting such a heat radiating member and a buffer layer, it is possible to further reduce the thermal stress generated inside the package and to make the heat radiation from the semiconductor element more efficient.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings described below, those having the same functions are denoted by the same reference numerals, and the repeated description thereof will be omitted.

Embodiment 1 FIG. 1 is a sectional view showing the structure of a package for mounting a semiconductor element according to Embodiment 1 of the present invention.

1 is a frame, 11 is an opening at the top of the frame 1, 12 is a hollow portion of the frame 1, and 13 is a frame 1
2, a semiconductor element; 21, a wiring formed on the lower surface of the semiconductor element 2; 3, a wiring substrate made of a semiconductor; 31, a planar waveguide wiring formed on the upper surface of the wiring substrate 3; Is a high-frequency glass coaxial bead, 51 is a center conductor of the glass coaxial bead 5, and 52 is a glass coaxial bead 5.
And 23 are bonding bumps.

The frame 1 is made of, for example, copper, copper tungsten, aluminum, stainless steel, Kovar, titanium,
It is made of a metal housing such as molybdenum and invar. A coaxial terminal which is a component of the high-frequency coaxial connector, that is, a glass coaxial bead 5 is provided on a side wall of the metal frame 1. A wiring board 3 is arranged inside the frame 1. The wiring substrate 3 is made of a semiconductor such as silicon, gallium arsenide, gallium nitride, indium phosphide, and silicon carbide. Also, on the upper surface of the wiring board 3,
A planar waveguide wiring 31 such as a microstrip or a grounded coplanar is formed using a thin film of copper, gold, tungsten, or an alloy thereof. The planar waveguide wiring 31 on the wiring board 3 and the center conductor 51 of the coaxial bead 5 arranged on the side wall of the frame 1 are connected by solder,
They are mechanically and electrically connected by means such as silver paste, welding, brazing, or bonding.

Electrode terminals (not shown) for bump bonding are formed on the upper surface of the wiring board 3 and the lower surface of the semiconductor element 2. Each electrode terminal is electrically connected by bump bonding, that is, by a bump 23. It is connected to the.

In this semiconductor element mounting package, airtightness is ensured by mechanically connecting the seal cap 4 to the upper surface of the frame 1 by means such as seam welding, brazing, or bonding.

As described above, the package for mounting a semiconductor element according to the first embodiment has the opening 11 at the upper part, the hollow part 12, and at least one coaxial terminal on the side wall, that is, the glass coaxial bead. Frame 1, a wiring board 3 housed inside the frame 1 and made of a semiconductor and mechanically and electrically connected to the glass coaxial bead 5, a semiconductor element 2 housed inside the frame 1, and an opening. A cap 4 covering the portion 11 is provided, and an electrode terminal (not shown) provided on the lower surface of the semiconductor element 2 and an electrode terminal (not shown) provided on the upper surface of the wiring board 3 are formed by bump bonding (that is, the bump 23). Connection).

In the first embodiment, the wiring board 3 is made of a semiconductor, and the planar waveguide wiring 3 such as a microstrip or a grounded coplanar formed on the wiring board 3 is used.
1 and the center conductor 51 of the glass coaxial bead 5 provided on the frame 1 are connected by solder or silver paste, and the semiconductor element 2 is directly connected to the wiring board 3 by bump bonding. Inside, the center conductor 51 of the glass coaxial bead 5 is connected to the semiconductor element 2 without a large impedance mismatch, the signal loss at the connection point between the two is reduced, and the performance of the high-frequency semiconductor element over the millimeter wave band is improved. It is possible to draw out enough.

Since the wiring board 3 is made of a semiconductor,
It can be manufactured using a high-precision semiconductor process, and can be mounted with high precision.Even if a semiconductor element with a quasi-millimeter-wave band, a millimeter-wave band and higher-frequency characteristics is mounted, its performance can be fully exploited. be able to. Further, since the stress caused by the difference in linear expansion coefficient between the semiconductor element 2 and the wiring substrate 3 made of a semiconductor can be reduced, the reliability of the connection between them can be improved, and a high-precision element capable of coping with an ultra-high frequency element can be realized. A semiconductor device mounting package can be realized.
Furthermore, if the same semiconductor as the semiconductor element 2 is used as the material of the wiring board 3, it is possible to eliminate stress caused by a difference in linear expansion coefficient between the semiconductor element 2 and the wiring board 3 made of the semiconductor. Therefore, by selecting a material having a similar linear expansion coefficient as the material of the wiring board 3 and the frame 1 (for example, the wiring board 3 is made of gallium arsenide and the frame 1 is made of Kovar), the thermal stress generated inside the package is reduced. can do. As a result, the life of the semiconductor package can be extended.

Embodiment 2 FIG. 2 is a sectional view showing the structure of a semiconductor device mounting package according to Embodiment 2 of the present invention.

Reference numeral 8 denotes a buffer layer having elasticity.

In the second embodiment, in addition to the structure of the first embodiment, a rubber-like film, resin, paste material, etc. having a thickness of 10 to 500 μm is provided between the lower surface of the wiring board 3 and the inner surface of the frame 1. An elastic buffer layer 8 made of

In the second embodiment, such a buffer layer 8
, The thermal stress generated inside the package can be further reduced.

Third Embodiment FIG. 3A is a cross-sectional view showing a structure of a semiconductor device mounting package according to a third embodiment of the present invention, and FIG. 3B is a view of part A of FIG. Enlarged detailed side view, (c), (d)
Is a view similar to (b) showing another configuration.

Reference numeral 53 denotes a conductive buffer layer having elasticity, and reference numeral 54 denotes a metal conductor.

In the third embodiment, in addition to the structure of the first embodiment, for example, the through-hole 13 for mounting the glass coaxial bead 5 on the side wall of the frame 1 and the glass coaxial bead 5 are coaxially arranged. This is provided with a conductive buffer layer 53 having elasticity such as conductive silicon rubber. Metal conductor 5
4 is made of a metal such as copper, copper tungsten, aluminum, stainless steel, Kovar, titanium, molybdenum, and invar.

For example, there is a configuration as shown in FIGS. 3A and 3B, a metal conductor 54 and a conductive buffer layer 53 having elasticity are arranged around a high-frequency glass coaxial bead 5 composed of a central conductor 51 and a dielectric 52, and a mechanical hole is formed in the through-hole 13. (C) is a configuration in which a metal conductor 54, a conductive buffer layer 53 having elasticity, and a metal conductor 54 are arranged around the glass coaxial bead 5 and mechanically connected to the through-hole 13; d) around the glass coaxial bead 5,
An electrically conductive buffer layer 53 having elasticity and a metal conductor 54 are arranged,
The configuration is such that it is mechanically connected to the through hole 13.

The reason why the buffer layer 53 is made conductive is that the thickness of the dielectric 52 of the glass coaxial bead 5 is not changed.
That is, the configuration of the glass coaxial beads 5 is not changed.

In the third embodiment, the stress applied to the mechanical / electrical connection between the central conductor 51 of the glass coaxial bead 5 and the wiring board 3 by inserting the elastic buffer layer 53 into the through hole 13. Can be alleviated.

Fourth Embodiment FIG. 4 is a sectional view showing the structure of a semiconductor device mounting package according to a fourth embodiment of the present invention.

Reference numeral 9 denotes a heat radiating member (lid), and reference numeral 10 denotes a buffer layer having elasticity.

In the fourth embodiment, in addition to the structure of the first embodiment, a heat radiating member 9 is provided between the inner surface of the cap 4 and the upper surface of the semiconductor element 2, and the heat radiating member 9 and the semiconductor element 2 are connected. An elastic buffer layer 10 is inserted between them.

The heat radiation member 9 is made of, for example, copper, copper tungsten, aluminum, stainless steel, Kovar, titanium,
Molybdenum, metal plate such as invar, or alumina,
It is made of ceramic such as aluminum nitride. The elastic buffer layer 10 is made of a rubber-like film, resin, paste, or the like having a thickness of 10 to 500 μm. in this case,
The inner surface of the cap 4 and the heat dissipating member 9 may be mechanically connected by means such as bonding. Further, the heat dissipating member 9 and the buffer layer 10 may be mechanically connected by means such as adhesion.

The elastic buffer layer 10 may be disposed between the inner surface of the cap 4 and the heat radiating member 9 without being inserted between the heat radiating member 9 and the semiconductor element 2. in this case,
The heat radiating member 9 and the semiconductor element 2 may be mechanically connected by means such as bonding. Further, the inner surface of the cap 4 and the buffer layer 10 may be mechanically connected by means such as adhesion.

In the fourth embodiment, by inserting such a heat radiating member 9 and a buffer layer 10, the thermal stress generated inside the package can be further reduced and the semiconductor element 2
The efficiency of heat radiation from the device can be improved.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments, and it is needless to say that various changes can be made without departing from the gist of the present invention. It is.

[0042]

As described above, according to the present invention,
By using a semiconductor as the wiring board and using bump bonding to connect the semiconductor element and the wiring board, it is possible to support the quasi-millimeter wave band, the millimeter wave band and higher frequency bands, Since it can be manufactured in the same semiconductor process as the element, high-precision mounting is possible, and the characteristics of the ultrahigh-frequency semiconductor element can be sufficiently brought out. Further, by using a semiconductor of the same material as the semiconductor element for the wiring board, it is possible to eliminate stress caused by a difference in linear expansion coefficient between the semiconductor element and the wiring board,
The life of the semiconductor package can be extended.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a semiconductor element mounting package according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a structure of a package for mounting a semiconductor element according to a second embodiment of the present invention;

FIG. 3A is a cross-sectional view showing a structure of a semiconductor element mounting package according to a third embodiment of the present invention, FIG. 3B is an enlarged detailed side view of part A of FIG. (C),
(D) is an enlarged detailed side view similar to (b) showing another configuration.

FIG. 4 is a sectional view showing a structure of a package for mounting a semiconductor element according to a fourth embodiment of the present invention;

FIG. 5 is a sectional view showing a structure of a conventional package for mounting a semiconductor element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Frame, 2 ... Semiconductor element, 3 ... Wiring board, 4 ... Seal cap, 5 ... Glass coaxial bead, 8, 10 ... Buffer layer, 9 ... Heat dissipation member, 11 ... Opening of frame, 12 ... Hollow part of frame Reference numeral 13 denotes a through hole of a frame, 21 denotes wiring of a semiconductor element, 23 denotes a bump, 31 denotes a planar waveguide wiring on a wiring board, 51 denotes a central conductor of a glass coaxial bead, and 52
... A dielectric of glass coaxial beads, 53. A conductive buffer layer having elasticity, 54.

Claims (5)

[Claims] 1. A frame having an opening at an upper portion, a hollow portion, and at least one coaxial terminal on a side wall; and a semiconductor housed in the frame and made of a semiconductor. An electrically connected wiring board, a semiconductor element housed inside the frame, and a cap covering the opening; an electrode terminal provided on a lower surface of the semiconductor element; and an electrode terminal provided on an upper surface of the wiring board. A package for mounting a semiconductor element, wherein the electrode terminals are connected by bump bonding. 2. The package according to claim 1, wherein said wiring board is made of gallium arsenide, and said frame is made of Kovar. 3. The package for mounting a semiconductor device according to claim 1, wherein an elastic buffer layer is inserted between a lower surface of said wiring board and an inner surface of said frame. 4. The coaxial terminal is provided through a through hole provided in a side wall of the frame, and an elastic buffer layer is provided between the through hole and the coaxial terminal. Item 2. The package for mounting a semiconductor element according to Item 1. 5. A heat radiation member is provided between the inner surface of the cap and the upper surface of the semiconductor element, and between the heat radiation member and the semiconductor element, or between the inner surface of the cap and the heat radiation member. 2. The package for mounting a semiconductor element according to claim 1, wherein an elastic buffer layer is inserted.