JP2938800B2 - Semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device mounted on a high-frequency device such as a communication device and a radar.

[0002]

2. Description of the Related Art A high-frequency semiconductor device is used at a high frequency of a microwave band or higher, and is mounted on a high-frequency device such as a communication device and a radar. As described above, since the influence of high frequency cannot be ignored, the high frequency semiconductor device usually includes a hermetically sealed package.

Here, a conventional high frequency semiconductor device will be described with reference to FIG. FIG. 4A is a sectional view of a conventional semiconductor device including a control circuit and a high-frequency circuit in a package case. The ceramic high-frequency circuit board 41 is provided in one space of the package case 411 having two spaces.
4 is installed, and a ceramic control circuit board 416 is installed in the other space. This package case 411 is sealed with a lid 413. The high-frequency circuit and the control circuit are electrically connected to the outside of the package by a high-frequency coaxial connector 412 and a control connector 418. The control signal transmitted from the ceramic control circuit board 416 to the ceramic high-frequency circuit board 414 is generally connected to the glass terminal 419.

In the above structure, the ceramic high-frequency circuit board 414 and the ceramic control circuit board 416 are not integrated, and therefore, the glass terminals 419 are used for transmitting control signals.
For example, post-joining parts are required, the structure is complicated, and the number of plug-in connections increases, resulting in high cost.

There is a semiconductor device having a structure in which a ceramic high-frequency circuit board and a ceramic control circuit board are integrated. FIG. 4B shows a cross-sectional view of the structure. This structure includes a package case 421 and a high-frequency composite circuit board 42.
4 are joined and sealed with a lid 423. Electrical connection to the outside of the package is made by a high-frequency coaxial connector 422 and a control connector 427. By the way, a via hole is opened in the high-frequency composite circuit board, and the high-frequency circuit and the control circuit are electrically connected by a conductor (hereinafter, referred to as a VIA conductor) provided in the via hole (hereinafter, a via hole). The connection part by a hole is described as VIA). The high-frequency composite circuit board 424 is manufactured by laminating a ceramic substrate and a circuit conductor and simultaneously firing the laminated body (hereinafter, referred to as a co-fire simultaneous firing technique). Circuit conductor and V used in co-fire co-firing technology
As the IA conductor, a thick film sintered metal of a high melting point metal such as tungsten or molybdenum having low conductivity is generally used. Also,
Nickel (N
i), a plating process of gold (Au) or the like is performed.

[0006]

Since the semiconductor device having the above structure has a skin effect as a characteristic of high frequency, most of the high frequency current flows through the thick film layer having low conductivity. As a result, high-frequency loss increases, and high-frequency performance deteriorates. The high frequency composite circuit board 42
4 and the package case 421 are generally joined using a silver brazing material. Since a mechanical buffering effect can hardly be expected from this thick film layer, there is a problem that the semiconductor device itself sometimes breaks due to heat expansion difference from the package case 421 to which the high-frequency composite circuit board 424 is joined due to heat generation of the semiconductor device itself. .

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the high-frequency loss in a semiconductor device and to provide a highly reliable semiconductor device which is not broken by a difference in thermal expansion between a circuit board and a package case.

[0008]

In order to achieve the above-mentioned object, only a ceramic control circuit board is manufactured by using a co-fire co-firing technique, and a ceramic high-frequency circuit is electrically conductive on one side of the ceramic board. A circuit conductor with high efficiency is provided and manufactured. The ceramic control circuit board and the ceramic high-frequency circuit board are integrally joined with a ground conductor interposed therebetween. A copper plate or a copper-based alloy plate having a large ductile and mechanical buffer effect is used for the ground conductor, and the DBC (D-irect Bonding) is used.
(Copper) technology. The DBC technique is a technique for directly joining a substrate such as a ceramic and a copper plate or a copper-based alloy plate. This can be achieved by simultaneously firing a ceramic substrate and a copper plate or a copper-based alloy plate in a vacuum or a reducing atmosphere. With this structure, high-frequency loss of the circuit can be reduced, and cracks in the substrate and the like due to the difference in thermal expansion are reduced.

[0009]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to the examples shown in FIGS. FIG. 1 shows one embodiment of the present invention. FIG. 1A shows a perspective cutaway view,
FIG. 1B is a cross-sectional view taken along the line AA ′. The ceramic control circuit board is made by a co-fire co-firing technique after multilayer wiring with a ceramic plate using a high melting point metal such as tungsten or molybdenum as a circuit conductor. Ceramic high-frequency circuit board 115 and ceramic control circuit board 116
To the ground conductor 1 having a hole for passing the transmission pin 120 through.
At 14, bonding is performed by DBC technology, and the circuit board is integrated. As the ground conductor, a copper plate or the like having a high mechanical buffering effect and a high conductivity is used. Then the ceramic high-frequency circuit board 11
The circuit conductor 121 of the high-frequency circuit is formed of a metal having a high conductivity such as gold on the surface on the fifth side. This integrated circuit board is called a composite circuit board. The package case 111 is made of a conductive metal, and the transmission pins 120 are soldered to the mounting portion of the control circuit board 116 made of silver. Electrical input and output to and from the outside of the package case 111 are connected by a high-frequency coaxial connector 112 and a control coaxial connector 119.

With the above configuration, only the ceramic control circuit board 116 is manufactured by the co-firing simultaneous firing technique, so that it can be integrated in a small size. In addition, since the circuit conductor 121 of the ceramic high-frequency circuit board 115 is made of gold or the like and the ground conductor 114 common to the high-frequency circuit and the control circuit is made of a metal having high conductivity such as a copper plate, high-frequency loss can be reduced. As a result, it is possible to simultaneously reduce the external dimensions of the semiconductor device and reduce the loss. Further, the package case 111
Cracks caused by the difference in thermal expansion between the ceramic high-frequency circuit board 115 and the control circuit board 116
Since the ground conductor 114 is annealed during the DBC process, the mechanical buffering effect is high and cracking is reduced.

In addition to the above, a coaxial connector is not used as an input / output unit for electrically connecting to the outside of the package case.
The present invention can be applied to a case where a lead terminal is used. FIG. 2A shows another embodiment, and FIG. 2A shows a perspective cutaway view, and FIG. 2B shows a cross-sectional view taken along line BB ′. The description of the overlapping part corresponding to FIG. 1 is partially omitted.

The ceramic high-frequency circuit board 215 extends to the outside of the package case 211, and a ceramic wall 222 is laminated on the upper surface of the extension. On the other hand, the circuit conductor 221 passes through the lower portion of the ceramic wall 222 and is formed up to the substrate end. High frequency circuit lead terminal 2
Reference numeral 12 is connected to the circuit conductor 221 exposed in the cutout portion of the package case 211. Similarly, for the control circuit, the ceramic control circuit board 216 extends to the outside of the package case 211, and a ceramic wall 223 is laminated on the upper surface of the extension. A control circuit lead terminal 219 is connected to an extension of the control board exposed in the notch of the package case 211.

According to the above configuration, only the ceramic control circuit board 216 is manufactured by the co-firing simultaneous firing technique and compactly integrated, and the circuit conductor 221 of the ceramic high-frequency circuit board 215 and the ground conductor 214 of the composite circuit board are provided. ,
Since a metal having high conductivity can be used, the external dimensions of the semiconductor device can be reduced and the high-frequency low-loss property can be satisfied at the same time. Further, cracks generated due to a difference in thermal expansion between the package case 211 and the composite circuit board are also caused by a DBC between them.
The presence of the ground conductor 214 that has been annealed during the process results in a high mechanical buffering effect and less cracking.

Although the embodiment using only the coaxial connector or the lead terminal has been described above, the present invention can be applied even if the coaxial connector and the lead terminal are mixed. Also,
The same effect as the embodiment using only the coaxial connector and the lead terminal can be obtained.

Another embodiment of the present invention will be described with reference to FIG. As described with reference to FIGS. 1 and 2, the case of the package case using the conductive metal has been described, but the present invention is also applicable to the package case using the ceramic. FIG. 3A is a perspective cutaway view, and FIG.
A cross-sectional view of -C 'is shown. Note that, in FIG. 3, the description of the overlapping portions corresponding to FIGS. 1 and 2 is partially omitted.

The composite circuit board has a structure similar to that of the embodiment shown in FIGS. 1 and 2 described above, and includes a ceramic control circuit board 316 and a ceramic high-frequency circuit board 315 made by co-fire simultaneous firing technology. The ground conductor 314 is joined so as to be interposed therebetween. The semiconductor device of this embodiment has a structure in which the semiconductor device is bonded to a ground plane 324 of a large device including a package. Further, a conductor is formed in a notch provided on the side surface of the package (hereinafter, referred to as a half via). The ground conductor 314 and the ground plane 324 are electrically connected by the half via 323.

With the above structure, only the ceramic control circuit board 316 is manufactured by the co-firing simultaneous firing technique and compactly integrated, and the circuit conductor 321 of the ceramic high-frequency circuit board 315 and the ground conductor 314 of the composite circuit board are provided. ,
Since a metal having high conductivity can be used, the external dimensions of the semiconductor device can be reduced and the high-frequency low-loss property can be satisfied at the same time. In addition, cracks caused by the difference in thermal expansion between the package case 311 and the composite circuit board are also caused by DBC between them.
The presence of the ground conductor 314 that has been annealed during the process results in a high mechanical buffering effect and less cracking. further,
The package case 311 and the composite circuit board can be integrated all at once by the DBC technique using the ground conductor 314 using a copper plate.

[0018]

According to the present invention, it is possible to provide a highly reliable semiconductor device which is small and lightweight and has a small high-frequency loss.

[Brief description of the drawings]

FIG. 1 is a diagram showing a semiconductor device according to an embodiment of the present invention;

FIG. 2 is a diagram showing a semiconductor device according to another embodiment of the present invention;

FIG. 3 is a diagram showing a semiconductor device according to another embodiment of the present invention;

FIG. 4 is a diagram of a semiconductor device according to a conventional example.

[Explanation of symbols]

111,211,311,411,421 ・ ・ ・ ・ Package case 112,412,422 ・ ・ ・ ・ ・ ・ ・ High frequency coaxial connector 113,213,313,413,423 ・ ・ ・ ・ Lid 114,214,314・ ・ ・ ・ ・ Ceramic control circuit board 117,217,317,415,425 ・ ・ ・ ・ High frequency element 118,218,318,417,426 ・ ・ ・ ・ Control element 119,418,427・ ・ ・ ・ ・ ・ ・ Circuit conductor 212,312 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ High frequency circuit lead terminal 219,319 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Control circuit lead terminal 222,223,322 ・ ・ ・ ・ ・ ・ ・ ・ Ceramic wall 323 ・ ・ ・ ・ Half via 424 ・ ・ ・ ・ High frequency composite circuit board 428 ・ ・ ・ ・ VIA

Claims (7)

(57) [Claims] At least one layer of a first substrate and a circuit conductor is provided.
The first circuit board laminated above and one surface of the second board
A second circuit board provided with circuit conductors, each of said circuit boards
Connected to one side and sandwiched between the two circuit boards
A ground conductor, and the ground conductor and the package case;
Is formed by joining at least a part of the semiconductor device. 2. The method according to claim 1, wherein the first substrate and the circuit conductor have at least one layer.
The first layer formed by stacking the above and firing the obtained laminate is
And a circuit conductor provided on one surface of the second substrate.
A second circuit board, each connected to one side of the circuit board;
A ground conductor sandwiched between the two circuit boards is provided.
And at least one of the ground conductor and the package case is
A semiconductor device formed by joining parts . 3. The first circuit according to claim 1, wherein a hole is formed in the ground conductor.
Providing a transmission pin for connecting the substrate and the second circuit board;
The semiconductor device according to claim 1 or 2, wherein: 4. The method according to claim 1, wherein the first substrate and the circuit conductor have at least one layer.
The first circuit board laminated above and one surface of the second board
A second circuit board provided with circuit conductors, each of said circuit boards
Connected to the ground plane, and sandwiched between the two circuit boards.
Having a common ground conductor, and drilling a hole in the ground conductor,
Connecting the first circuit board and the second circuit board
A semiconductor device comprising a transmission pin . 5. The method according to claim 1, wherein the first substrate and the circuit conductor are formed in at least one layer.
The first layer formed by stacking the above and firing the obtained laminate is
And a circuit conductor provided on one surface of the second substrate.
A second circuit board, each connected to a ground plane of the circuit board;
And a common ground conductor sandwiched between the two circuit boards.
A hole in said ground conductor, said first circuit
Providing a transmission pin for connecting the substrate and the second circuit board;
A semiconductor device characterized by the above. 6. The method of claim 1 which comprises using the copper material to the ground conductor, claim 2, claim 4 or claim 5 Symbol
Mounting semiconductor device. 7. The method of claim 1, characterized in that a ceramic material in the first, second circuit board, according to claim 2, wherein
6. The semiconductor device according to claim 4 or claim 5 .