JP3464119B2 - High frequency package and its connection structure - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a high frequency package for hermetically sealing a high frequency semiconductor element, a high frequency element such as a high frequency passive element, and a connection structure thereof.
The present invention relates to a high-frequency package that can be directly connected to a waveguide formed in an external electric circuit or the like while maintaining airtightness, and a connection structure thereof.

[0002]

2. Description of the Related Art In recent years, the informationization of society has progressed, and the transmission of information has become wireless and personalized as typified by mobile phones. Under such circumstances, in order to enable higher speed and large capacity information transmission, millimeter wave (30 to 300 GHz)
The development of semiconductor devices operating in the z) region is in progress. Recently, with the progress of such high frequency semiconductor device technology,
As its application, various application systems using millimeter-wave radio waves such as inter-vehicle radar and wireless LAN have been proposed. For example, an inter-vehicle radar using millimeter waves (see Electronics Society Conference of the Institute of Electronics, Information and Communication Engineers 1995, SC-7-6), cordless camera system (Electronic Society Conference of the Institute of Electronics, Information and Communication Engineers 1995, C-137). See), high-speed wireless LA
N (see Electronics Society of Electronics, Electronics Society Conference, 1995, C-139) has been proposed.

As the application of millimeter waves progresses in this way, the development of elemental technologies for enabling those applications is also proceeding at the same time. In particular, various electronic parts have required transmission characteristics. However, how to reduce the size and cost is a major issue.

Among such elemental technologies, how to connect the package housing the high frequency element and the external electric circuit with a simple and small structure is an important element. In particular, how to connect the external electric circuit in which the waveguide with the smallest transmission loss is formed and the package in which the high frequency element is mounted has been a big problem.

As a conventional method of connecting a high-frequency package to a waveguide formed in an external electric circuit, a method of temporarily converting the high-frequency package into a coaxial line using a connector and connecting it to the waveguide is used. In an electric circuit, a method is used in which a waveguide is once connected to a microstrip line or the like and then the microstrip line is connected to a high frequency package.

Recently, a method of directly connecting a package containing a high frequency element to a waveguide of an external electric circuit has been proposed (see Electronics Society Conference of the Institute of Electronics, Information and Communication Engineers 1995, SC-7-5). In this proposal, quartz is embedded in a part of a lid that hermetically seals an element in the cavity, an electromagnetic wave is introduced into the cavity through the quartz embedded portion, and a waveguide installed in the cavity is used.
It is connected to a microstrip line conversion board.

[0007]

However, as described above, the waveguide of the external electric circuit is once provided with another transmission line configuration such as a connector or a microstrip line.
The method of connecting to the package has a problem that the connection structure becomes complicated and the connection structure itself becomes large because it is necessary to secure a region for forming a connector and other transmission lines. In addition, the transmission loss may increase due to other line configurations or connectors.

On the other hand, the method of directly introducing from the waveguide into the inside of the cavity of the package in the form of electromagnetic waves is effective in that the connection structure can be miniaturized, but passes through the cavity forming member such as the lid. In this case, in order to reduce the loss of electromagnetic waves, it is necessary to use a material having a low dielectric constant and a low dielectric loss tangent in the passage part, and as a result, as described in the above document, a low dielectric constant such as quartz is used. , A process of embedding a low loss material is required. Such an embedding process not only impairs the reliability of hermetic sealing, but also
It is completely unsuitable for mass production.

It is also conceivable that the cavity forming member is made of a material having a low dielectric constant and low loss.
In addition to those electrical properties, various other properties such as mechanical strength, hermetic sealing, and metallization are required as the materials that make up the package. Suitable materials that satisfy all of these properties and can be manufactured at low cost. Is not found.

That is, the above difficulty is caused by trying to introduce a high frequency signal into the cavity of the package as an electromagnetic wave through the waveguide. That is, since the signal is an electromagnetic wave in the portion introduced into the cavity, it is necessary to achieve both airtight sealing and low loss in this portion.

The present invention has been made to solve the above-mentioned problems, and can be directly connected to a waveguide provided in an external electric circuit with low loss without affecting the airtightness of a high frequency element. It is an object of the present invention to provide a high frequency package including various connecting portions. Another object of the present invention is to provide a connection structure that can be connected with low loss to a waveguide provided in an external electric circuit using the high frequency package.

[0012]

Means for Solving the Problems As a result of intensive studies on the above problems, the inventors of the present invention have found that a line connected to a high frequency element housed in a cavity is electromagnetically coupled, a via conductor, a microstrip line-strip line. Using a line that can transmit high frequency signals such as through the dielectric,
Causes led outside the cavity, the package-side heat
The terminal sink is provided with a waveguide termination structure, and by arranging it so as to close the open end of the waveguide of the external electric circuit, it is possible to directly connect with the waveguide having the open end. It was found that the device can be sealed and the device can be reliably sealed.

That is, the high-frequency package of the present invention includes a dielectric substrate made of a dielectric material, a cavity for accommodating a high-frequency element, and a waveguide formed on a part of the surface of the dielectric substrate outside the cavity. A connection part for connecting to a tube, a high-frequency transmission line for connecting the high-frequency element and the connection part, and a high- frequency element bonded to the dielectric substrate
A high-frequency package including a metal heat sink on which the connecting part is formed, the connecting part being formed on one surface of the dielectric substrate, and having an open end with an end being electromagnetically opened. And a signal conductor that functions as a monopole antenna in the waveguide, and a termination structure that is formed on the other surface of the dielectric substrate and that functions as the termination of the waveguide, and the termination structure is the heat sink. Provided in
It is characterized in that the opened cross section is composed of a concave cavity .

The high-frequency package connection structure of the present invention is formed on a dielectric substrate made of a dielectric material, a cavity for housing a high-frequency element, and a part of the surface of the dielectric substrate outside the cavity. And a high-frequency transmission line for connecting the high-frequency element and the connection part, and a connection part for connecting to the waveguide, and a high-frequency transmission line connected to the dielectric substrate.
And a structure for connecting a high-frequency package including a metal heat sink on which the high-frequency element is mounted to a waveguide having an open end that is electromagnetically open,
As the connecting portion of the high-frequency package, a signal conductor which is formed on one surface of the dielectric substrate and has an open end portion whose tip is electromagnetically opened and which functions as a monopole antenna in the waveguide. And a termination structure formed on the other surface of the dielectric substrate and functioning as a termination of the waveguide, the termination structure being provided on the heat sink.
It is characterized in that the provided cross section is composed of a concave cavity .

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a high frequency package will be described below with reference to FIGS. According to each figure,
In the high frequency package, a high frequency element 4 is mounted and mounted on the surface of the dielectric substrate 1 in a cavity 3 formed by a dielectric substrate 1 and a lid 2, and the cavity 3 is hermetically sealed. A high-frequency transmission line connected to the high-frequency element 4 is formed on the surface of the dielectric substrate 1 inside the cavity 3, and the high-frequency transmission line is formed on a part of the surface of the dielectric substrate outside the cavity 3. In addition, it is connected to a connection portion that can be connected to a waveguide formed in an external electric circuit or the like by a connection line such as electromagnetic coupling, a via conductor, or a microstrip line-strip line.

In the package of FIG. 1, a high frequency element 4 is mounted on the surface of a dielectric substrate 1, and the high frequency element 4 is connected to an end portion thereof, together with a ground layer 5 formed inside the dielectric layer 1. The center conductor 6 forming the microstrip line a is adhered and formed. The center conductor 7 forming the microstrip line b together with the ground layer 5 is also formed as a high frequency transmission line on the back surface of the dielectric layer. Then, the microstrip lines a and b
Has a structure that is electromagnetically coupled by the slot hole 8 formed in the ground layer 5. Specifically, such an electromagnetic coupling structure faces the positions where the ends of the respective lines project from the center of the slot with a length of ¼ wavelength of the signal frequency, as described in JP-A-1-266578. To be combined.

Further, a planar signal conductor 9 is formed on the back surface of the dielectric substrate 1 so as to extend from the central conductor 7 of the microstrip line b, and an electromagnetic wave having no ground layer 5 at the tip thereof is formed. An open end 10 is formed which is open to the outside. The distance x from the end of the ground layer 5 to the open end of the signal conductor 9 is set to a quarter wavelength length of the transmission signal wavelength.

According to this high frequency package,
The connection portion A is provided with a waveguide termination structure. In the package of FIG. 1, the signal conductor 9 of the dielectric substrate 1
A metallic waveguide terminating member 11 having a concave cross section is placed on the surface opposite to the surface on which is formed. As shown in the perspective view of FIG. 1 (c), the concave waveguide terminating member 11 has a hollow shape, and its inner peripheral shape matches the inner circumference of the waveguide to be connected. The bottom surface 12 of the inner wall of this member forms the end of the waveguide. The recess forming surface of the member 11 is joined to the surface of the dielectric substrate 1 of the package by brazing or the like. The depth of the concave portion of the member 11 is set such that the distance Y from the inner wall bottom surface 12 of the member to the signal conductor 9 when joined to the dielectric substrate 1 is a quarter wavelength length of the transmission signal wavelength.

2A and 2B are views for explaining a structure for connecting the package of FIG. 1 to a waveguide 13 connected to an external electric circuit or the like. FIG. 2A is an assembly drawing and FIG. 2B is a connection structure. FIG. According to FIG. 2, the waveguide 13 connecting this package comprises an electromagnetically open end 14 which has no termination. Then, as shown in FIG. 2A, the dielectric layer 1b is used as the waveguide 1
While being sandwiched between the open end portion 14 and the terminating member 11, the connection portion A of the high-frequency package is joined so as to close the open end portion of the waveguide 13.

With such a connection structure, as shown in FIG.
As shown in FIG. 3, the open end 14 of the waveguide 13 is terminated by the termination member 11 mounted on the dielectric substrate 1. Then, inside the waveguide 13 terminated by the terminating member 11, the signal conductor 9 having the open end 10 is inserted into the waveguide 13. At this time, by setting the length X of the open end 10 to be a quarter wavelength of the transmission signal wavelength, the signal conductor 9 having the open end 10 is set to 4
It functions as a one-wavelength monopole antenna, resulting in a package and a waveguide 13 having an open end 14.
Can be connected with.

According to the connection structure of FIG. 2, the high-frequency signal transmitted through the waveguide 13 is planar due to the conversion structure of the waveguide constituted by the waveguide 13 and the connection portion A and the signal conductor 9. Is converted into a signal on the signal conductor 9. The high-frequency signal converted into the signal on the signal conductor 9 is transmitted through the microstrip line b, and is transmitted to the microstrip line a inside the package by electromagnetic coupling through the slot hole 8 formed in the ground layer 5. It is transmitted to the element 4.

As described above, according to this embodiment, the high-frequency signal transmitted through the waveguide is converted into the signal on the planar circuit by the conversion structure for the signal conductor, and then the signal conductor inside the cavity of the package is converted. Therefore, it is possible to connect the high frequency element in the package and the waveguide while surely sealing the cavity. Moreover, since the package itself is provided with the termination structure of the waveguide, it is possible to connect to the waveguide having the open end.

In the package of FIG. 1, the microstrip line a and the microstrip line b are electromagnetically coupled to each other by the slot hole 8, but in addition, each is a through-hole conductor penetrating the slot hole 8. It is also possible to connect the ends of the lines.

Further, the ends of the center conductors 6 and 7 of the microstrip lines a and b are made to have a large line width at the ends of the center conductors 6 and 7 for good electromagnetic coupling through the slot holes 8. Or the shape of the slot hole 8 is dogbone type,
The via hole conductor connected to the ground layer 5 is used as the slot hole 8
It is desirable to form a plurality so as to surround the.

Next, FIG. 3 is a schematic sectional view of a package having the termination structure of the present invention. In such an example,
According to the package, on the back surface of the dielectric substrate 1, a central conductor 16 forming a microstrip line c together with the ground layer 15 formed inside the dielectric substrate 1 as a high frequency transmission line connected to the high frequency element 4. Are formed. And the central conductor 1 of the microstrip line c
Reference numeral 6 denotes the wall body 1 when penetrating the wall body 17 made of a dielectric material.
Conductor layer 1 formed to join lid 2 to the surface of 7
8 and the ground layer 15 form the dielectric layer 1a and the wall 17
It is converted into a strip line 19 having a structure sandwiched via the, passes through the inside of the wall body 17, and is led out of the cavity 3. Then, on the surface of the dielectric substrate 1, a microstrip line d is formed by the ground layer 15 and the central conductor 20 formed by extending from the central conductor 16 of the microstrip line c via the strip line 19. A signal conductor 22 having an open end portion 21 having no ground layer is formed by extending the central conductor 20 of the microstrip line d.

On the surface of the dielectric substrate 1 opposite to the surface on which the signal conductor 22 is formed, a termination member 11 similar to that described with reference to FIG. 1 can be mounted, and as shown in FIG. 3, the inner surface terminates. A block 24 having a structure and having a cavity 23 made of metal is joined to the dielectric substrate 1. Then, as described with reference to FIG. 2, the termination member 11 is mounted on the waveguide 13 having the open end 14 so as to close the open end 14, so that the termination member 11 terminates the waveguide 13. And the signal conductor 22 having the open end portion 21 functions as a monopole antenna, so that the package and the waveguide can be directly connected. Further, the block 24 is
It is made entirely of metal and functions as a heat sink by mounting the high-frequency element 4 on a part of this block.
There is.

Also in the structure of FIG. 3, the sealing structure in the cavity 3 is not affected at all,
In addition, it is possible to directly connect to a waveguide having an open end by a combination of conventionally known high-frequency transmission lines capable of low-loss transmission.

In the package of the present invention, the dielectric substrate 1 is made of a raw material powder made of a ceramic material such as Al ₂ O ₃ or AlN, a glass material, or a glass ceramic material made of a composite of glass and an inorganic filler. In addition to being formed by firing after molding using, it can be formed by a printed board made of an organic material. Further, each conductor line and the ground layer for transmitting a signal can be formed of a refractory metal such as tungsten or molybdenum, or a low resistance metal such as gold, silver, copper, aluminium, or platinum. It is also a great feature that they can be integrally formed by the conventional laminating technique.

[0029]

As described in detail above, according to the high-frequency package and its connection structure of the present invention, the tip is electromagnetically opened outside the cavity, which functions as a monopole antenna when combined with a waveguide. By forming a signal conductor having an open end that is formed as a connection portion and connecting the signal conductor to the high-frequency transmission line of the package,
A connection structure with low transmission loss of high-frequency signals can be realized without affecting the package sealing structure. As a result, the reliability and mass productivity of the package forming this connection structure can be improved. Moreover, since the package itself is provided with the terminal structure of the waveguide, the package can be directly connected to the waveguide having the open end.

[Brief description of drawings]

1A and 1B are views for explaining one embodiment of a high-frequency package, where FIG. 1A is a schematic sectional view, FIG. 1B is a plan view thereof (however, a lid is not shown), and FIG. It is a perspective view of a member.

2 is a view for explaining a connection structure of the high-frequency package of FIG. 1 with a waveguide having an open end,
(A) is an exploded perspective view for explaining a connection method, (b)
[FIG. 4] is a cross-sectional view of a main part when connected.

FIG. 3 is a schematic cross-sectional view of a high frequency package including the termination structure of the present invention.

[Explanation of symbols]

1 Dielectric substrate 2 lid 3 cavities 4 High frequency element 5, 15 Ground layer 6,7,16,20 Central conductor a, b, c, d Microstrip line 8 slot holes 9,22 Signal conductor 10, 21 open end 11 Termination member 12 Inner wall bottom 13 Waveguide 14 Open end 17 wall 18 Conductor layer 19 strip line 23 Cavity 24, 25 blocks 26, 27 metal layer

Continuation of front page (56) Reference JP-A-7-221223 (JP, A) JP-A-8-148930 (JP, A) JP-A-8-274513 (JP, A) JP-A-6-268402 (JP , A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01P 5/107 H01L 23/12 301 H03F 3/60 WPI (DIALOG)

Claims (2)

(57) [Claims] 1. A dielectric substrate made of a dielectric material, a cavity for accommodating a high frequency element, and a connection portion formed on a part of the surface of the dielectric substrate outside the cavity for connecting to a waveguide. And a high-frequency transmission line for connecting the high-frequency element and the connection part, and joined to the dielectric substrate
A high frequency package comprising a metal heat sink on which a high frequency element is mounted , wherein the connecting portion is formed on one surface of the dielectric substrate, and an open end portion is electromagnetically opened at a tip end. has, and a signal conductor that functions as a monopole antenna in waveguide, formed on the other surface of the dielectric substrate, comprising a termination structure that serves as a termination of the waveguide, the termination structure
Structure is a cavity with a concave cross section provided in the heat sink
High-frequency package characterized by consisting of parts . 2. A dielectric substrate made of a dielectric material, a cavity for housing a high-frequency element, and a connection formed on a part of the surface of the dielectric substrate outside the cavity for connecting to a waveguide. Section, a high-frequency transmission line for connecting the high-frequency element and the connection section, and a contact with the dielectric substrate.
A structure for connecting a high-frequency package including a metal heat sink on which a combined high-frequency element is mounted to a waveguide having an electromagnetically open end. A signal conductor, wherein the connection portion of the high frequency package is formed on one surface of the dielectric substrate, has an open end portion whose tip is electromagnetically opened, and functions as a monopole antenna in the waveguide. A termination structure functioning as a termination of a waveguide formed on the other surface of the dielectric substrate, the termination structure being provided on the heat sink.
A connecting structure for a high-frequency package, characterized in that the formed cross section comprises a hollow portion having a concave shape.