JP4790571B2 - High frequency module - Google Patents

Description

  The present invention relates to a high-frequency module on which high-frequency components such as an amplifier component, a power supply component, and an oscillator are mounted and an EMI (Electro Magnetic Interference) shield is required.

  In a high-frequency module in which high-frequency components such as amplifier components, power supply components, and oscillators are mounted, a phenomenon called oscillation, which does not operate normally due to leakage of radio waves into the high-frequency components, has been a problem. As one of measures for preventing this oscillation, a method of machining a case for a high frequency module into a desired shape so that radio waves do not leak is employed. However, in order to prevent radio waves from leaking, it must be processed into a complicated shape, and the number of processing steps increases, making it impossible to obtain an inexpensive high-frequency module.

  Further, conventionally, as another method for preventing leakage of radio waves, a method of sandwiching a conductive material between the upper surface of the high-frequency component and the cover has been taken. Among these methods, the most general method is a method in which a metal block is fixed between a high-frequency component upper surface and a cover with a conductive adhesive. In this method, it is necessary to cope with various gaps between the upper surface of the high-frequency component and the cover. Therefore, several types of metal blocks must be prepared in advance, and metal blocks having appropriate dimensions must be selected and used. In addition, since the number of parts increases and the manufacturing time increases, it is not suitable for mass-produced products.

  Therefore, conventionally, as another method, instead of the metal block, a comb-like thin plate spring metal member (hereinafter referred to as a finger) is adhered to the upper surface of the high frequency component with a conductive adhesive, and the finger and the high frequency module cover are bonded. And a method of bringing them into electrical contact. This method can reduce the number of parts and the number of work steps (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 07-162183

  However, in the method using the finger described in Patent Document 1 described above, when the environmental conditions of the place where the high-frequency module is installed are severe, the resin material to which the finger is bonded deteriorates due to a continuous cycle of high temperature and high humidity. In addition, stable performance cannot be obtained, and there is an unsolved problem that the case for the high-frequency module must be processed into a complicated shape.

  The present invention has been made to solve the above-described problems, and a desired radio wave shielding space can be formed in the module without requiring a case having a complicated shape and without increasing the number of parts. An object of the present invention is to obtain a high-frequency module that can be an inexpensive high-frequency module and that can be highly reliable because a resin material is not required for bonding purposes.

  In order to solve the above-described problems, a high-frequency module according to the present invention includes a box-shaped case made of a metal material and provided with an input / output connector for an electric signal on an opposite surface, and a substantially entire length of the case fixed in the case. A substrate with an extended ground pattern formed on the surface, a high-frequency component that is fixed on the same side as the substrate in the case and the surface is formed of a metal material, and is made of a spring metal and is opposite to the substrate in the member case A shield member having a fixed portion fixed to the wall surface, a ground pattern contact portion erected from the fixed portion toward the ground pattern, and a high-frequency component contact portion erected from the fixed portion toward the high-frequency component. The shield member has a ground pattern contact portion that is electrically connected to the ground pattern at the front end portion of the shield member. The first space for storing the high-frequency component and the other second space are partitioned in a radio wave shielding manner so that the first space has a desired cross-sectional shape. Is brought into contact with the high frequency component to obtain electrical continuity between the case and the high frequency component.

  In the high-frequency module according to the present invention, the fixed portion of the shield member is fixed by caulking to a protrusion formed on the inner wall of the case.

  Furthermore, the high-frequency module according to the present invention is formed of a flexible material, a substrate having a ground pattern formed on the surface thereof, a container containing the substrate, and a case having a conductive lid placed on the upper surface of the container. A shield member erected between the lid and the substrate so that one end is electrically connected to the lid and the other end is electrically connected to the ground pattern of the substrate. It has a strip-shaped contact portion that contacts the ground pattern or the conductive surface of the lid, and an electromagnetic partition space is formed in the container by the shield member.

  According to the high frequency module of the present invention, the ground pattern contact portion of the shield member forms a radio wave shielding space having a desired cross-sectional shape by electrically contacting the tip portion extending over the entire length of the case to the ground pattern. In this case, the high-frequency component is housed, and the high-frequency component contact portion of the shield member contacts the high-frequency component with the tip portion to obtain electrical continuity between the case and the high-frequency component. Therefore, a desired radio wave shielding space can be formed in the module without increasing the number of components, and an inexpensive high-frequency module can be obtained.

  Further, according to the high frequency module according to the present invention, since the fixing portion of the shield member is fixed by caulking to the protrusion formed on the inner wall of the case, it is highly reliable without requiring a resin material for bonding purposes. can do.

  According to the high-frequency module of the present invention, the substrate having the ground pattern formed on the surface thereof, the case for housing the substrate, the case having the conductive lid disposed on the upper surface of the vessel, and one end of the lid And a flexible shield member erected between the lid and the substrate so that the other end is electrically connected to the ground pattern of the substrate. It has a strip-shaped contact portion that contacts the conductive surface of the ground pattern or the lid, and an electromagnetic partition space is formed in the container by this shield member, so a complicated shape case is not required, Further, a desired radio wave shielding space can be formed in the module without increasing the number of components, and an inexpensive high-frequency module can be obtained.

  Embodiments of a high-frequency module according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment FIG. 1 is a perspective view showing a state in which a case lid showing an embodiment of a high-frequency module according to the present invention is opened. FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 of the high-frequency module with the case lid closed. FIG. 3 is a partial cross-sectional view of the high-frequency module with the case lid closed, in a direction orthogonal to the cross-section of FIG. 1 to 3, a high-frequency module 100 according to the present embodiment includes a box-shaped case 10 made of a metal material, a substrate 20 and a high-frequency component (semiconductor component) 30 housed in the case 10, and a high-frequency module. A finger (shield member) 40 made of a thin spring metal material (flexible material) provided in the case 10 to prevent radio waves from leaking into the component 30 is provided.

  The case 10 is made of a metal material and includes a case main body (container) 11 and a case lid body (lid body) 12 that closes the opening of the case main body 11. The case main body 11 is manufactured by die casting, has a substantially rectangular parallelepiped box shape with the entire one side opened, and the substrate 20 and the high-frequency component 30 are accommodated in the bottom of the box. The case lid 12 is made by press molding, has a substantially flat plate shape, and is made of a conductive rubber provided on the entire edge of the flat plate for the purpose of sealing the opening of the case body 11 in a radio wave shielding manner. The EMI gasket 13 is sandwiched and fastened to the case body 11 with screws. An input connector 14 and an output connector 15 are provided on two surfaces of the case main body 11 that are opposed to each other in the length direction.

  The substrate 20 is made of ceramic, glass epoxy, or the like as a base material, is divided into three pieces, is arranged over substantially the entire bottom portion of the case body 11, and is fixed to the case body 11 with screws. Adjacent substrates 20 are electrically connected by a wire 22 such as a gold wire or a gold ribbon. Electrical components are mounted on the substrate 20. On the surface of the substrate 20, a ground pattern 21 formed of a material having excellent conductivity such as gold is provided. The ground pattern 21 includes a long portion 21 a formed over substantially the entire length of the case body 11 and a short portion 21 b that is bent at a right angle at the end of the substrate 20 and extends.

  The high-frequency component (semiconductor component) 30 is specifically an amplifier component or an oscillator provided with at least two, and is disposed in the notch of the substrate 20 and fixed to the bottom of the case body 11 with a screw 31. 20 is electrically connected by a wire 22 such as a gold wire or a gold ribbon, and transmits a signal in a high frequency band in cooperation with an electrical component on the substrate 20. The surface of the high-frequency component 30 is covered with a metal material, and a ground surface is formed on at least the upper surface.

  The finger 40 is a thin rectangular plate that is made of a material such as phosphor bronze that is flexible and has high springiness and good conductivity, and is fixed by a thin rectangular shape that is fixed to the inner side wall surface of the case lid 12. A portion 41, a comb-like shape (strip shape), a ground pattern contact portion 42 erected toward the ground pattern 21 so as to be bent from an edge of the fixing portion 41, and a comb-like shape (strip shape). The high-frequency component contact portion 43 is formed by cutting and raising on the main surface of the fixed portion 41 and standing from the fixed portion 41 toward the high-frequency component 30. The ground pattern contact portion 42 further includes a long portion 42 a formed over the entire long side of the fixed portion 41 and a short portion 42 b formed over the entire short side of the fixed portion 41. The fixing portion 41 is fixed by caulking to a protrusion 12 a formed on the inner side wall surface of the case lid 12. The protrusions 12a are formed at a pitch at which radio waves having a desired frequency do not leak.

  The ground pattern contact portion 42 is electrically conductive by bringing the tip of the long portion 42 a into contact with the long portion 21 a of the ground pattern 21 and bringing the tip of the short portion 42 b into contact with the short portion 21 b of the ground pattern 21. Have taken. In this way, the finger 40 and the ground pattern 21 partition the space inside the case 10 into a first space B that accommodates the high-frequency component 30 and another second space C in a radio wave shielding manner, and at the same time, One space B has a desired cross-sectional shape (FIG. 2). The high frequency component contact portion 43 obtains electrical continuity by bringing the tip portion into contact with the ground surface above the high frequency component 30.

  Next, the operation will be described. The electrical components inside the case 10 (electrical components on the substrate 20 and high-frequency components 30) are connected by a wire 22 such as a gold wire or a gold ribbon, and high-frequency band signals are transmitted from the connectors 14 and 15 provided on the wall surface of the case 10. Perform input and output. At this time, since the signal in the high frequency band also propagates in the space inside the case 10, the inside of the case 10 can be regarded as a waveguide, and the width dimension a of the case internal sectional space is at least twice the height dimension b. In this case, the characteristics of a waveguide generally called a rectangular waveguide can be approximated. The frequency band of the signal propagating through the rectangular waveguide can be defined by Equation (1), and a signal in a frequency band lower than fc (cutoff frequency) in Equation (1) propagates in this space. I can't.

fc = C / 2a (1)
here
fc = cut-off frequency [Hz]
C = speed of light [3 × 10 ⁸ m / s]
a = Width dimension of the internal cross-section space [mm]

  From the propagation characteristics of the rectangular waveguide, it can be seen that desired electrical characteristics can be obtained by controlling the dimensions of the internal space of the case 10. In the present embodiment, the dimension of the case internal space B is controlled by bringing the finger 40 attached to the case lid 12 into contact with the ground pattern 21 and the high frequency component 30 provided on the substrate 20, and desired electrical characteristics can be easily achieved. Can be obtained. Further, by attaching the EMI gasket 13 to the case lid 12 and sandwiching the EMI gasket 13 between the case body 11 and the case main body 11, leakage of external signals to the high frequency module 100 and leakage to the outside can be performed without using many screws. Can be prevented.

  Next, a method for manufacturing the high-frequency module 100 according to the present embodiment will be described. The ground pattern contact portion 42 and the high frequency component contact portion 43 of the finger 40 are made of a material such as phosphor bronze, which is a thin plate and has high spring property and conductivity in order to reduce the contact pressure with the ground pattern 21 and the high frequency component 30. It is desirable to mold into a shape. By determining the desired inter-slit dimension from the above formula (1) by determining the desired dimension, signal leakage can be prevented without completely shielding the space. Therefore, there is no risk of applying an excessive load to the electrical component, and a high-reliability high-frequency module can be obtained.

  The finger 40 is fixed to the case lid 12 by fitting into the protrusion 12a formed by extrusion processing on the case lid 12, and crushing and crimping the protrusion 12a. At this time, the finger 40 and the case lid 12 are fixed without any gaps by bonding or the like by determining the interval for caulking the finger 40, that is, the interval between the protrusions 12a by obtaining a desired dimension from the above equation (1) Even without this, it is possible to prevent leakage of signals from the gaps in the joints. As described above, since the finger 40 and the case lid 12 can be joined without interposing a resin material such as an adhesive, it is stable without deterioration even when the environmental conditions where the high frequency module 100 is installed are severe. Performance can be obtained.

  Further, the case lid 12, the finger 40, and the caulking structure of the finger to the case lid 12 are all moldable by pressing with a mold, and the EMI gasket 13 provided on the case lid 12 is Since it can be molded by application of an electrically conductive rubber by an automatic machine, a significantly cheaper high-frequency module can be obtained compared to the conventional one.

  As described above, according to the high-frequency module of the present embodiment, a case with a complicated shape is not required, and the number of parts does not increase, so that an assembling that is easy and inexpensive can be obtained. In addition, since the structure is simple and it is not necessary to use an adhesive or the like, there is an effect that a high-frequency module with stable performance can be obtained without deterioration even when the environmental conditions are severe. Further, since the case lid 12 and the finger 40 can be manufactured by press molding, the EMI gasket 13 is automatically applied, and the case main body 11 can be manufactured by die casting, there is an effect that a high-frequency module that can be easily mass-produced can be obtained.

  The present invention is suitable for application to high-frequency modules on which high-frequency components such as amplifier components, power supply components, and oscillators are mounted, and is particularly installed in places with severe environmental conditions such as high-temperature and high-humidity continuous cycles. It is optimally applied to high frequency modules.

It is a perspective view which shows a mode that the case cover which shows embodiment of the high frequency module of this invention was opened. It is arrow sectional drawing which follows the AA line of FIG. 1 of the high frequency module of the state which closed the case cover body. It is a fragmentary sectional view of the direction orthogonal to the section of Drawing 2 of a high frequency module in the state where a case lid was closed.

Explanation of symbols

10 Case 11 Case body (container)
12 Case lid (lid)
13 Conductive rubber (EMI gasket)
14 Input connector 15 Output connector 20 Substrate 21 Ground pattern 22 Wire rod 30 High frequency component 31 Screw 40 Finger (shield member made of spring metal member)
41 Finger fixed portion 42 Finger ground pattern contact portion 43 Finger high frequency component contact portion 100 High frequency module

Claims (8)

A box-shaped case made of a metal material and provided with an input / output connector for electrical signals on the opposite surface; a substrate on which a ground pattern fixed in the case and extending over the entire length of the case is formed;
A high-frequency component fixed on the same side as the substrate in the case and having a surface formed of a metal material;
Produced by a spring metal, the substrate and the fixed portion fixed to the wall on the opposite side, a ground pattern contacting portion erected from the fixed portion toward the ground pattern in the case, and the from the fixed part A shield member having a high-frequency component contact portion erected toward the high-frequency component,
The ground pattern contact portion of the shield member is configured such that the tip portion is brought into electrical contact with the ground pattern, so that the space inside the case is divided into a first space for housing the high-frequency component and other second spaces. In addition, the first space is partitioned in a radio wave shielding manner so as to have a desired cross-sectional shape,
The high-frequency module contact portion of the shield member has an end portion in contact with the high-frequency component to obtain electrical continuity between the case and the high-frequency component. The high-frequency module according to claim 1, wherein the fixing portion of the shield member is fixed by caulking to a protrusion formed on an inner wall of the case. The high-frequency module according to claim 2, wherein the protrusions are formed at a pitch at which desired radio waves do not leak on the inner wall of the case. The ground pattern contact portion and the high-frequency component contact portion of the shield member have a comb-like shape, and the comb-teeth pitch is set to a pitch at which a desired radio wave does not leak. The high-frequency module according to claim 1. The high-frequency module according to any one of claims 1 to 4, wherein the shield member is manufactured by press molding. The case includes a box-shaped case body having an opening on one side, and a case lid that closes the opening of the case body.
The high frequency according to any one of claims 1 to 5, wherein the case lid is fixed to the case body by sandwiching conductive rubber so as to seal the opening of the case body. module. The high-frequency module according to claim 6, wherein the case lid is produced by press molding. The high-frequency module according to claim 6, wherein the conductive rubber is formed by automatic coating.

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