JP2007115901A - High frequency apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high frequency apparatus including a heat dissipation structure of a high frequency power amplifying element, which provides sufficient heat dissipation effects, even if the high frequency power amplifying element is used with a large calorific value. <P>SOLUTION: The high frequency apparatus consists of: a circuit board 2 having the high frequency power amplifying element 3 including a heat dissipation fin 3b and a body 3a; a case 1 for storing the board 2; and a shield cover 6 to be put over the board 2. Heat generated by the element 3 is dissipated from the rear of the fin 3b to the case 1. In addition, to obtain further sufficient heat dissipation effects; a heat transmission cover 4 formed not in contact with the body 3a and mounted on the surface of the fin 3b, and a thermal conductor 8 thermally connecting the cover 4 with the shield cover 6, are provided so as to dissipate the heat generated by the element 3 to the shield cover 6 through the cover 4 and the conductor 8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a high-frequency device having a heat dissipation structure of a high-frequency power amplifying element such as a power amplifier MMIC (monolithic microwave integrated circuit), GaAsFET (gallium arsenide FET), etc., and to improve thermal conductivity. In addition, the present invention relates to a device that can easily maintain, repair, and replace high-frequency characteristics.

  As a heat dissipation structure of a high-frequency power amplification element such as a power amplifier MMIC, for example, there is a structure as shown in FIG. This is attached to the circuit board 2, the circuit board 2 on which the high-frequency power amplifying element 3 composed of the radiating fins 3b and the main body (element part) 3a is mounted, the casing (case) 1 for housing the circuit board 2, and the circuit board 2. The heat dissipating fin 3b is fixed to the housing 1 with screws 10 and the circuit board 2 is pressed at the tip of the shield cover 6 by tightening the screws 9, so that the high frequency power amplifying element 3 is The generated heat is dissipated from the back surface of the radiation fins 3b to the housing 1, but when the power amplifier has a high output, the amount of heat generated is large, so the size of the housing 1 is limited. However, the above structure has a problem that sufficient heat dissipation cannot be performed.

  As a method for solving the above problem, it is conceivable to dissipate heat generated by the high-frequency power amplifying element 3 also on the shield cover 6 side in addition to the housing 1 in FIG. For example, as shown in FIG. 6B, heat is radiated to the shield cover 6 side. This is composed of a circuit board 12 on which a heat generating component 12a such as a power amplifier is mounted, and a housing (case) 13 (corresponding to the shield cover 6 in FIG. 6A) that houses the circuit board 12. While the component 12a is molded on the circuit board 12 with a resin 14 made of a good thermal conductor, a contact piece 15 whose tip is in contact with the resin 14 is provided on the inner surface of a housing (case) 13, and the heat generated from the heat generating component 12a is resin. 14 is configured to radiate heat through the contact piece 15 and the housing (case) 13 (see, for example, Patent Document 1).

  However, when a high-frequency power amplifying element such as a power amplifier MMIC is mounted on a high-frequency circuit board constituted by a planar circuit such as a microstrip line, the resin 14 is applied to the high-frequency power amplifying element as in the above example. When the mold is applied, there is a problem that the resin 14 may adhere to the terminals and signal line patterns of the high frequency power amplifying element and adversely affect high frequency characteristics. There is also a problem that repair and replacement cannot be performed when the MMIC is broken or needs to be replaced due to variations in high frequency characteristics. Further, the contact piece 15 formed on the casing (case) 13 is brought into contact with the resin 14, but due to variations in dimensional accuracy during assembly, heat conduction becomes insufficient, and high frequency power amplification. There is a risk of damage to the element.

JP-A-8-227952 (second page, FIG. 1)

  In view of the above problems, the present invention, for example, in a high-frequency circuit board mounted with a high-frequency power amplifying element such as a power amplifier MMIC, adversely affects its high-frequency characteristics and makes it impossible to repair or replace the high-frequency power amplifying element. Even when the heat generated by the high-frequency power amplifying element is large (even with a limited size housing), no resin molding is performed, no mechanical stress is applied to the high-frequency power amplifying element. An object of the present invention is to provide a high-frequency device having a heat dissipation structure for a high-frequency power amplifying element that makes it possible to obtain a sufficient heat-dissipation effect and thereby does not reduce the reliability of components and the like.

  The present invention has been made to solve the above problems, and as a first means, a circuit board on which a high-frequency power amplifying element composed of a radiating fin and a main body is mounted, and a housing for housing the circuit board, And a shield cover attached to the circuit board or the housing, and the heat generated by the high-frequency power amplifying element is radiated from the back surface of the radiation fin to the housing and is not in contact with the main body. A heat transfer cover to be mounted on the surface of the heat dissipating fin; and a heat conduction means for thermally connecting the heat transfer cover and the shield cover, and the high frequency via the heat transfer cover and the heat conduction means. The heat generated by the power amplification element is radiated to the shield cover.

  As a second means, a circuit board on which a high-frequency power amplifying element composed of a radiating fin and a main body is mounted, a housing that houses the circuit board, a shield cover that adheres to the circuit board or the housing, An exterior cover that covers the shield cover and is attached to the casing, and is formed so that heat generated by the high-frequency power amplification element is radiated from the back surface of the radiation fin to the casing and is not in contact with the main body. A heat transfer cover that is mounted on the surface of the heat radiating fin; and heat conduction means that thermally connects the heat transfer cover and the exterior cover, and the high frequency signal is provided via the heat transfer cover and the heat conduction means. The heat generated by the power amplification element is radiated to the exterior cover.

  In the first or second means, the heat conducting means is formed integrally with the shield cover.

  In the first or second means, the heat conducting means is formed separately from the shield cover.

  In the case of a high-frequency device having a heat dissipation structure for a high-frequency power amplification element according to the present invention, when the high-frequency power amplification element is fixed to a housing or a circuit board, the high-frequency power amplification element is formed so as not to apply mechanical stress. While covering the heat transfer cover and fixing both together to the housing, the heat transfer cover and the heat transfer means for thermally connecting the shield cover or the exterior cover located on the heat transfer cover are provided. Therefore, it is possible to dissipate heat from the high frequency power amplifying element not only to the housing side to which the high frequency power amplifying element is fixed, but also to a shield cover or an exterior cover located above the high frequency power amplifying element. Become. Accordingly, since it is not necessary to mold the high-frequency power amplifying element with resin, there is no adverse effect on the high-frequency characteristics due to the resin, and the high-frequency power amplifying element can be easily repaired and replaced. Furthermore, since a sufficient heat dissipation effect can be obtained even with a high-frequency power amplification element with a large amount of heat generation, the heat dissipation structure can be changed according to the heat generation amount of the high-frequency power amplification element to be used, and a limited size common housing Thus, it is possible to realize an optimal heat dissipation structure for high-frequency power amplifying elements having different outputs (different heat generation amounts).

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
Note that the same components as those in FIG.

FIG. 1 is a side sectional view showing a first embodiment of a high-frequency device, and FIG. 2 is an exploded perspective view of the high-frequency device. In the figure, 1 is a case (case) made of a metal having good thermal conductivity, 2 is a circuit board on which a high-frequency power amplifying element 3 comprising heat radiating fins 3b and a main body 3a is mounted, and 4 is a main body of the high-frequency power amplifying element 3. A heat transfer cover formed so as not to come into contact with 3a, 5 is a gap formed between the main body 3a of the high-frequency power amplifying element 3 and the heat transfer cover 4, 6 is a shield cover attached to the circuit board 2, and 8 is a shield cover 6 The heat conductor is integrally formed with the heat transfer cover 4 and acts as a heat transfer means from the heat transfer cover 4 to the shield cover 6.
The casing 1 and the shield cover 6 are made of, for example, an aluminum die cast that is strong and has good thermal conductivity, and the heat transfer cover 4 is made of aluminum, brass, or the like that has good thermal conductivity and is easy to process. Use.

  The above-described constituent members are configured as shown in FIG. 2, and the casing 1 has a plurality of screw holes 1a for screwing the heat radiation fins 3b of the high-frequency power amplifying element 3 on the bottom side thereof, and a shield cover. 6 and a plurality of screw holes 1b for fixing the circuit board 2 are provided.

  The circuit board 2 is provided with a square hole 2a corresponding to the heat radiation fin 3b of the high-frequency power amplifying element 3 at the center, and a plurality of holes 2b through which the mounting screws 9 of the shield cover 6 are passed. Yes.

  The heat transfer cover 4 is open at the front and rear, and has holes 4a through which the mounting screws 10 are passed before and after the left and right mounting surfaces (flanges). The heat transfer cover 4 is covered from the upper part of the main body 3a of the high-frequency power amplifying element 3, and is fixed to the bottom surface of the housing 1 by using the mounting screws 10 together with the heat radiation fins 3b. A gap 5 as shown in FIG. 1 is formed between them to protect the main body 3a of the high-frequency power amplifying element 3 from mechanical external pressure.

  The shield cover 6 has a box shape with an open bottom, a columnar heat conductor 8 is integrally provided at the ceiling, and holes 6b through which mounting screws 9 are passed at the four corners. The heat conductor 8 comes into contact with the upper surface of the heat transfer cover 4 when inserted into the circuit board, the lower end of the side wall contacts the circuit board 2, and the shield cover 6 and the circuit board 2 are attached to the housing 1 by tightening the mounting screws 9. It is designed to be fixed.

FIG. 3 is a side sectional view showing a second embodiment of the high-frequency device. FIG. 4 is an exploded perspective view of the high-frequency device. The difference from the first embodiment is that the high-frequency device is less leaky and waterproof. In other words, an exterior cover 7 that covers the shield cover 6 is attached to the upper portion of the housing 1 in order to keep it. The outer cover 7 is made of, for example, an aluminum die cast that is strong and has high thermal conductivity.
Hereinafter, description of members common to Example 1 will be omitted, and differences will be described.

  The structural member has a form as shown in FIG. 4, and the casing 1 has a plurality of screw holes 1 a for screwing the heat radiation fins 3 b of the high frequency power amplifying element 3 on the bottom side thereof, and a shield cover 6. A plurality of screw holes 1b for fixing the circuit board 2 are provided, and a stepped portion 1c and a plurality of screw holes 1d for mounting and fixing the exterior cover 7 on the top are provided.

  The shield cover 6 has a box shape with an open bottom, holes 6a through which the heat conductor 8 passes through the ceiling, holes 6b through which the mounting screws 9 pass through at the four corners. When inserted, the circuit board 2 is pressed by the lower end of the side wall, and the shield cover 6 and the circuit board 2 are fixed to the housing 1 by tightening the mounting screws 9.

The exterior cover 7 is provided with a plurality of holes 7 a through which the mounting screws 11 are passed, and is fixed to the case 1 through the mounting screws 11.
In addition, the heat conductor 8 provided between the heat transfer cover 4 and the case cover 7 has a larger diameter at the upper part to increase the contact area with the exterior cover 7.
Furthermore, examples of the high-frequency device provided with the heat dissipation structure of the high-frequency power amplifying element 3 according to the first embodiment or the second embodiment are devices such as a transmitter in which electronic components such as a mixer are mounted together with the high-frequency power amplifying element 3.

  As described above, in the case of a high-frequency device having a heat dissipation structure for a high-frequency power amplifying element according to the present invention, when the high-frequency power amplifying element 3 is fixed to the housing 1, mechanical stress is applied to the high-frequency power amplifying element 3. A heat transfer cover 4 formed so as not to be added is covered and fixed to the housing 1 integrally, while the heat transfer cover 4 and the shield cover 6 or the outer cover 7 positioned above the heat transfer cover 4 are thermally applied. Since the heat conductor 8 is connected to the heat conductor 8, the heat generated by the high-frequency power amplifying element 3 is not limited to the case 1 side to which the high-frequency power amplifying element 3 is fixed. Heat can be radiated to the shield cover 6 or the outer cover 7 located above the high-frequency power amplifying element 3 through the body 8, and the high-frequency power amplifying element 3 can be easily repaired and replaced.

Next, FIG. 5 will be described. FIG. 5 shows another embodiment of the present invention. In the case shown in FIG. 5A, the heat conductor 8 is formed into a simple columnar shape, while the heat transfer cover 4 and the exterior cover 7 are both provided. Circular recesses 4b and 7b for holding (standing) the heat conductor 8 are provided, and conductive grease is applied to the recesses 7b in order to improve thermal conductivity.
With such a configuration, the heat conductor 8 can be provided at a lower cost.

  In (B), the exterior cover 7 and the heat conductor 8 are integrally formed, and the heat transmitted through the heat transfer cover 4 if both are integrated in this way. Can be reliably transmitted to the exterior cover 7.

  Both (C) and (D) show that the shield cover 6 and the heat conductor 8 are integrally formed, and in the case of (D), the contact area with the exterior cover 7 is larger. It has become. Thus, if the shield cover 6 and the heat conductor 8 are integrated, the reliability of the shield cover 6 against high frequency leakage can be further increased.

  In (E), the heat conductor 8 is formed in a screw shape, while the female screw portion 7c is formed at a predetermined position of the exterior cover 7 to adjust the contact state between the heat transfer cover 4 and the heat conductor 8. The shield cover 6 is formed with a hole 6a through which the heat conductor 8 is passed.

  As described above, some forms of the heat transfer cover 4, the shield cover 6, the exterior cover 7, and the like that are deeply related to the heat conductor 8 are not limited to those illustrated in FIGS. 1 to 4. 5 may be configured as shown in each figure.

It is a sectional side view of the high frequency device which shows the 1st Embodiment of this invention. 1 is an exploded perspective view of a high-frequency device showing a first embodiment of the present invention. It is a sectional side view of the high frequency device which shows the 2nd Embodiment of this invention. It is a disassembled perspective view of the high frequency apparatus which shows the 2nd Embodiment of this invention. It is principal part sectional drawing which shows other embodiment of this invention, (A) is what simplified the shape of the heat conductor, (B) is what integrated the heat conductor and the exterior cover, (C) And (D) The heat conductor and the shield cover are integrated, and (E) is the heat conductor made into a screw shape. It is a sectional side view of the heat dissipation structure of the high frequency power amplifying element showing the conventional example. (A) is an example of the heat dissipation structure of the high frequency power amplifying element in which the heat radiating fin and the main body are integrated. An example of molding is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Circuit board 3 High frequency power amplification element 3a Main body 3b Radiation fin 4 Heat transfer cover 5 Air gap 6 Shield cover 6a Hole 7 Exterior cover 8 Thermal conductor

Claims (4)

  A circuit board on which a high-frequency power amplifying element composed of a radiating fin and a main body is mounted; a housing that houses the circuit board; and a shield cover that adheres to the circuit board or the housing; The heat generated from the back surface of the heat radiating fin is radiated from the back surface of the heat radiating fin to the housing, and is formed so as not to contact the main body, and is mounted on the surface of the heat radiating fin; And a heat conduction means for thermally connecting to the shield cover, and the heat generated by the high-frequency power amplifying element is radiated to the shield cover through the heat transfer cover and the heat conduction means.   A circuit board on which a high-frequency power amplifying element composed of a radiating fin and a main body is mounted; a housing that houses the circuit board; a shield cover that is attached to the circuit board or the housing; An outer cover that covers the shield cover, and heat generated by the high-frequency power amplifying element is radiated from the back surface of the radiating fin to the casing and is not in contact with the main body. A heat transfer cover to be mounted on the surface, and heat conduction means for thermally connecting the heat transfer cover and the exterior cover are provided, and the high-frequency power amplification element is generated through the heat transfer cover and the heat conduction means. A high-frequency device characterized in that heat is radiated to the exterior cover.   The high-frequency device according to claim 1 or 2, wherein the heat conducting means is formed integrally with the shield cover.   The high-frequency device according to claim 1 or 2, wherein the heat conducting means is formed separately from the shield cover.

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