JPH02246199A - Shield structure of high-frequency module - Google Patents

Abstract

PURPOSE:To improve the reliability of shielding between high-frequency circuit devices so that possibility of occurrence of crosstalk can be eliminated by putting a shield plate provided with numerous fins and having a crosssection of inverted U-shape on partition plate sections. CONSTITUTION:A shield plate 20 is constituted of a long main plate member 21, the lower surface of which is brought into tight contact with upper end faced 3A of partition plates 3-1 and 3-2 and a pair of side plates 22, between which the side walls 3B of the partition plates 3-1 and 3-2 are held, and has a crosssection of inverted U-shape. In addition, the shield plate 20 are provided with parallel fins formed by partially cutting and raising the main plate member 21. When the shield plate 20 is put on the partition plates, the numerous fins 23 are arranged at the upper section of the partition plates. When a lid 2 is brought into contact with the opening of a metallic case 1 and the case is sealed by seam welding in such state, the fins 23 elastically come into contact with the inner surface of the lid 2. Therefore, the gap between the partition plates and lid can be sealed stably.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a high-frequency module configured by accommodating a plurality of circuit devices each having a desired high-frequency circuit on a ceramic substrate in the same metal case, and particularly relates to its shield structure. The purpose of this module is to provide a shielding structure for a high-frequency module that has a high degree of shielding between the high-frequency circuit devices housed in the module and eliminates the risk of crosstalk. The inside of the metal case with an opening is partitioned as desired, and each high-frequency circuit configured on a ceramic substrate is mounted in each partitioned area, and the corresponding A high frequency module configured to connect ceramic substrates to each other includes: a main plate member whose lower surface is in close contact with the upper end surface of the partition plate; elastic elastic contact pieces arranged in parallel on the upper surface of the main plate member; A metal plate having an inverted U-shape in cross section, the metal plate having a pair of side plates having bent side edges and sandwiched between the side walls of the partition plate, and a notch provided at a position corresponding to the connection line at the bottom of the side plate. A configuration in which the shield plate is bridge-fitted to the partition plate, and the elastic contact piece comes into elastic contact with the inner surface of the lid while the lid is tightly sealed in the opening of the metal case. shall be.

[Industrial application field]

The present invention relates to a high frequency module configured by accommodating a plurality of circuit devices each having a desired high frequency circuit on a ceramic substrate in the same metal case, and particularly relates to a shield structure thereof.

In communication equipment, etc., devices that have high frequency circuits with different functions configured on circuit boards, such as intermediate frequency amplifiers that convert received microwave signals into intermediate frequency signals and then amplify them, and convert the amplified signals back into microwave signals. High frequency modules are widely used in which devices having different functions, such as a frequency conversion device, are accommodated in the same metal case 1 to simplify the components and downsize the device.

In such a high frequency module, not only the case itself must have a shield structure, but also the high frequency circuit devices must be electromagnetically shielded.

[Conventional technology]

FIG. 4 is a perspective view of a conventional high frequency module, with 1
is a box-shaped metal case 1 with an open top and made of a desired metal material (for example, an iron-nickel-cobalt alloy whose coefficient of thermal expansion is approximately equal to that of a ceramic substrate).

After mounting the desired high-frequency circuit device in the metal case 1, the opening of the metal case 1 is covered with a thin rectangular plate-shaped lid 2 made of the same material as the metal case 1, and the four peripheral edges of the lid 2 are covered. By seam welding etc. to the upper end surface of the side wall of the metal case 1,
The metal case 1 is electromagnetically shielded.

On the other hand, 3-1 is made of the same material as the thin rectangular metal case 1, with its bottom end surface brazed to the bottom plate of the metal case and one side end surface brazed to a selected side wall of the metal case. It is a partition plate.

Further, 3-2 has a bottom end surface brazed to the bottom plate of the metal case, one side end surface to the other side wall, and the other side end surface to the side end surface of the partition plate 3-10 with a desired large gap, that is, communication. This is a partition plate made of the same material as the thin rectangular metal case 1, which is fixed so as to face each other via the portion 4.

The heights of these partition plates 3-1 and 3-2 are equal and slightly lower than the height of the side wall of the metal case 1.

The metal case 1 that accommodates two high-frequency circuit devices has a space inside the metal case divided by a pair of partition plates 3-1 as described above.
．． It is divided into two areas by 3-2. However, in order to wire a connection line that connects both high-frequency circuit devices, the spaces between the two are communicated through a communication section 4.

The inner surface of the metal case 1, the surface of the partition plate, and the lower surface of the lid 2 are all plated with gold.

On the other hand, 5A and 5B are ceramic substrates, on the surface of which a desired chip component 6 is mounted and further a film circuit or the like is formed, thereby forming a desired high frequency circuit.

Further, a conductor layer is provided on the bottom surface of the ceramic substrates 5^, 5B by vapor depositing gold or the like.

Then, the bottom surface of the ceramic substrate 5A is brought into close contact with the bottom plate of one area partitioned by the partition plates 3-1 and 3-2, and the ceramic substrate 5A is mounted using a conductive adhesive or the like. Furthermore, the bottom surface of another ceramic substrate 5B is brought into close contact with the bottom plate of the other region, and the ceramic substrate 5B is mounted using a conductive adhesive or the like.

In addition, a desired pattern is provided on the portions of the ceramic substrates 5A and 5B corresponding to the communication portions 4, and the ends of the connection wires 8 made of, for example, gold wire, which are routed through the communication portions 4, are connected to each other. By thermocompression bonding to the terminals of the pattern, the double-cylinder frequency circuit device is electrically connected.

Note that each high-frequency circuit device is connected to the outside via a glass-sealed terminal 7 provided on the bottom plate of the metal case l.

In the high frequency module configured as described above, it is very difficult to seam weld the partition plate and the lid 2 when fixing the lid 2 to the metal case 1.

Therefore, a gap exists between the lid 2 and the upper end surface 3A of the partition plate 3-1, 3-2, which may cause crosstalk between the art dealer frequency circuit devices.

Therefore, conventionally, as shown in FIG.
Gold ribbons 10 are disposed at equal pitches on the upper end surface 3A of each of -1.3-2. These gold ribbons 10 are
It is fixed to the partition plate by thermocompression bonding only one end.

Therefore, when the lid 2 is fixed to the metal case 1, the gold ribbon 1
0 is inserted into the gap between the lid 2 and the upper end surface of the partition plate, and the lid and the partition plate are in contact with each other via the gold ribbon 10. That is, the double-cylinder frequency circuit device is electromagnetically cut off.

[Problem to be solved by the invention]

However, the regions on which the ceramic substrates 5A and 5B are mounted are connected via the communication portion 4. Therefore, there is a problem in that crosstalk occurs through the communication section 4.

Further, since the gold ribbon 10 has poor spring properties, there is a risk that it may come into close contact with the upper end surface of the partition plate over time. As a result, the gold ribbon IO no longer comes into contact with the inner surface of the lid, resulting in a problem that the shielding performance deteriorates.

The present invention was created in view of these points, and provides a shield structure for a high frequency module in which the reliability of the shield between high frequency circuit devices housed in a metal case is high and there is no risk of crosstalk occurring. It is intended to.

[Means to solve the problem]

In order to achieve the above object, the present invention, as illustrated in FIG.
The respective high-frequency circuits configured on the ceramic substrates 5^, 5B are mounted in the respective partitioned areas, and via the connection wires 8 wired to the communication portions 4 between adjacent partition plates,
In the high frequency module configured to connect the ceramic substrates 5A and 5B, each partition plate 3-
1, the main plate member 2 whose lower surface is in close contact with the upper end surface 3A of 3-2
1, elastic contact pieces 23 arranged in parallel on the upper surface of the main plate member 21, and a pair sandwiched between the side walls of partition plates 3-1 and 3-2 provided by bending both side edges of the main plate member 21. A shield plate 20 made of a metal plate and having an inverted U-shape in cross section is provided, having a side plate 22 and a notch 24 provided at a position corresponding to the connection line 8 at the bottom of the side plate 22.

Then, the shield plate 20 is bridged and fitted to the partition plate 3-1, 3-2, and the lid 2 is tightly sealed to the opening of the metal case 1.
The elastic contact piece 23 is configured to come into elastic contact with the inner surface of the lid 2.

[Effect]

As described above, adjacent partition plates 3-1.
3-2, the shield 1tIi20 is fitted so as to bridge the shield 1tIi20. Therefore, the communication portion 4 is electromagnetically blocked by the side plate 22 of the shield plate 20.

In addition, since the notch 24 is provided in the lower part of the side plate 22, the connection wire 8 is routed through the notch 24,
The shielding performance of the communicating part 4 is high.

On the other hand, on the main plate member 21 of the shield plate 20, elastic contact pieces 23 made of an elastic metal plate are arranged in parallel at a desired pitch.

Therefore, the elastic contact piece 23 is always in elastic contact with the inner surface of the lid 2, and the gap between the partition plate and the lid is stably shielded.

〔Example〕

The present invention will be specifically described below with reference to the drawings. Note that the same reference numerals indicate the same objects throughout the figures.

FIG. 1 is an exploded perspective view of an embodiment of the present invention;
FIG. 2 is a sectional view of an embodiment of the invention, and FIG. 3 is a perspective view of a shield plate of another embodiment of the invention.

In FIGS. 1 and 2, the metal case 1 has a box shape with an open top, and is made of a metal material whose coefficient of thermal expansion is approximately equal to that of the ceramic substrate.

After mounting the ceramic substrates 5A and 5B with desired high-frequency circuits in the metal case 1, the opening of the metal case 1 is covered with a thin rectangular plate-shaped lid 2.
The metal case 1 is electromagnetically shielded by seam welding the peripheral edge to the upper end surface of the side wall of the metal case 1.

On the other hand, the bottom end surface of the partition plate 3-1 is brazed to the bottom plate of the metal case, and one side end surface is brazed to the selected side wall of the metal case, so that the partition plate 3-1 is fixed inside the metal case 1. .

Also, the bottom end surface of the partition plate 3-2 is brazed to the bottom plate of the metal case, and one side end surface is brazed to the other side wall, so that the partition plate 3-2 is fixed adjacent to the partition plate 3-1. be. At this time, the side end surfaces of the partition plate 3-1 and the partition plate 3-2 face each other with a desirably large gap, that is, the communication portion 4 interposed therebetween. Further, the heights of these partition plates 3-1 and 3-2 are equal to each other and slightly lower than the height of the side wall of the metal case 1.

A desired chip component 6 is surface-mounted on the surface of the ceramic substrate 5A, and a film circuit is further formed to constitute a high-frequency circuit having a desired function. Furthermore, desired chip components 6 are surface-mounted on the surface of another ceramic substrate 5B, and a film circuit is further formed to constitute a high-frequency circuit having a function different from that of the ceramic substrate 5A.

Then, a ceramic substrate 5 is placed on the bottom plate of one area partitioned by the partition plate 3-1 and 3-2 using a conductive adhesive or the like.
A is mounted, and a ceramic substrate 5B is mounted on the bottom plate in the other region using a conductive adhesive or the like.

In addition, a desired pattern is provided on the portions of the ceramic substrates 5A and 5B corresponding to the communication portions 4, and the ends of the connection wires 8 made of, for example, gold wire, which are routed through the communication portions 4 are connected to the respective portions. The art dealer frequency circuit device is electrically connected by thermocompression bonding to the terminals of the pattern.

Note that each high-frequency circuit device is connected to the outside via a glass-sealed terminal 7 provided on the bottom plate of the metal case 1 or the like.

20 processes an elastic metal plate such as steel into a desired shape,
Furthermore, it is a shield plate with gold plating on its surface.

The shield plate 20 includes an elongated main plate member 21 whose lower surface is in close contact with the upper end surface 3A of each partition plate 3-1. This is a shield plate having an inverted U-shape in cross section, and is composed of a pair of side plates 22 that sandwich the side wall 3B of 1.3-2.

The length of the shield plate 20 is approximately equal to the width of the metal case 1, that is, (the length of the upper end surface of the partition plates 3-1, 3-2 + the gap width of the communication part 4), and the height of the side plate 22 is approximately equal to the width of the metal case 1. The depth is slightly less than 1.

The shield plates 20 each have a small square piece shape, and one side edge is connected to the main plate member 21, and the main plate member 21 is partially cut and raised so that the opposite side edge protrudes diagonally upward. 23 are arranged in parallel.

In addition, at the lower part of the side plate 22, at a position corresponding to the connection line 8,
A semicircular notch 24 is provided.

Then, align the shield plate 20 so as to bridge the partition plate 3-1, 3-2, press the shield plate 20,
By bringing the side plate 22 into elastic contact with the side wall 3B of the partition plate 3-1.3-2, the shield plate 20 is fitted onto the partition plate.

Therefore, as shown in FIG. 2, a large number of elastic contact pieces 23 are arranged on the upper part of the partition plate.

In this state, when the lid 2 is brought into close contact with the opening of the metal case 1 and sealed by seam welding, the elastic contact piece 23 comes into elastic contact with the inner surface of the lid 2.

Therefore, the gap between the partition plate and the lid is stably shielded.

Furthermore, since almost the entire surface of the communication section 4 except for the vicinity of the connection line 8 is shielded by the side plate 22, the communication section 4 is also electromagnetically blocked.

Further, since the shield plate 20 can be fitted to the partition plate simply by pressing, the mounting operation is easy. Further, since the shield plate 20 is made of steel or the like plated with gold, the material cost is lower than that of the conventional shield plate using a large number of gold ribbons.

Although the illustrated example uses a pair of adjacent partition plates to partition the inside of the metal case into two areas, the shield plate of the present invention can partition the metal case into three or four areas. Of course, it can be applied.

On the other hand, the shield plate 20-1 shown in FIG.
1, elastic contact pieces 23 are arranged in two rows in a staggered manner. Further, the side plate 22 is divided into desired small side plates by slits 25.

By providing the elastic contact pieces 23 in a staggered manner in this way, there are many contact points between the lid 2 and the shield plate 20-1, so the shielding performance is higher than that shown in FIG. Become.

Further, by dividing the side plate 22 into a large number of parts, there is an advantage that even if the side wall surface of the partition plate has some unevenness, the side plates can be better adhered to each other.

〔Effect of the invention〕

As explained above, the present invention provides a shield structure for a high frequency module in which a shield plate having a large number of elastic contact pieces and having an inverted U-shaped cross section is fitted into a partition plate portion, and the high frequency circuit housed in a metal case. The reliability of the shielding between devices is high (therefore, there is no risk of crosstalk occurring), and there are excellent practical effects in that the workability of attaching the shield plate is good and the cost is low.

[Brief explanation of drawings]

1. Fig. 1 is a perspective view showing an separated form of an embodiment of the present invention, Fig. 2 is a sectional view of an embodiment of the present invention, and Fig. 3 is a perspective view of a shield plate of another embodiment of the present invention. , FIG. 4 is a perspective view of a conventional example. In the figure, 1 is the metal case, 2 is the lid, 3-1.3-2
is the partition plate, 3A is the top end surface, 3B is the side wall,
4 is a communication part, 5A and 5B are ceramic substrates, 6 is a chip component, 7 is a glass sealed terminal, 8 is a connecting wire, 10 is a gold ribbon, 21 is a main plate member,
20. 20-1 is a shield plate, 22 is a side plate, 23 is an elastic contact piece, 24 is a notch, and 25 is a slit. a
, 4 sho JL diagram 1 fig. the present invention n good for the sword l/) time 圓 あ uzuki old mei's i tun ti: 托捌のshield sakame 41 child d oka diagram ichi shiba rice threat 10 Figure 7'/L diagram

Claims (1)

[Claims] Partition plates (3-1, 3-2,...) provided perpendicularly to the bottom plate
The inside of the metal case (1) with an open top is partitioned as desired, and each high frequency circuit configured on the ceramic substrate (5A, 5B,...) is mounted in each partitioned area, and the adjacent partition plate is mounted. The ceramic substrate (5A,
5B,...) in a high frequency module configured to connect each other, a main plate member (21) whose lower surface is in close contact with the upper end surface (3A) of the partition plate, and a main plate member (21) arranged in parallel on the upper surface of the main plate member (21). a pair of side plates (22) which are formed by bending both side edges of the main plate member (21) and are sandwiched between the side walls of the partition plate; and a lower part of the side plates (22). The connection line (
8) and a notch (24) provided at a position corresponding to
A shield plate (20) made of a metal plate and having an inverted U-shape in cross section is used, and the shield plate (20) is connected to the partition plates (3-1, 3-2,
...), and the lid (2) is attached to the metal case (1).
A shielding structure for a high frequency module, characterized in that the elastic contact piece (23) is configured to come into elastic contact with an inner surface of the lid (2) while being tightly sealed in an opening of the lid (2).