JPH02202095A - Grounding of microwave circuit - Google Patents

Abstract

PURPOSE:To enable a printed board to be grounded enough at an optional position by a method wherein a metal pin is inserted into a through-hole provided inside a ground pattern until one end of it reaches a through-hole stopper, the other end is held by a conductive metal pin retaining part, and an elastic metal contact section is brought into contact with a metal lid on a component mounting side. CONSTITUTION:A conductive metal pin retaining section 4 is fixed to a metal lid 22 on a pattern face side of a printed board 11. A metal pin 3 is provided with a metal rod 31, which is small enough in diameter to penetrate through a through-hole 12 provided to a printed board 11, where an elastic metal contact part 33 is provided to one end of the rod 31 and a through-hole stopper 32 is provided to a part of the rod 31 separate from the end by a specified distance. The metal pin 3 is inserted into the through-hole 12 provided in the grounding pattern on the pattern side as far as the through-hole stopper 32, the elastic metal contact part 33 is brought into contact with a metal lid 21 on a component mounting face side of the printed board 11, and the other end of the metal rod 31 is held by the conductive metal pin retaining section 4 to ground the printed board to a metal case 17. By this setup, a printed board can be grounded sufficiently at an optional position.

Description

[Detailed Description of the Invention] [Summary] Regarding the microwave circuit grounding method used in microwave radio equipment with one frequency up to about 2 GIIz, for example, when the microwave circuit is formed on a printed board, any In order to ensure sufficient grounding at the position of Contain it inside.

When grounding the printed board to the metal case, a conductive metal pin holding portion is fixed to the metal lid on the pattern side of the printed board, and at least one end of a metal rod having a diameter that can pass through the through hole is attached. One elastic metal contact part is placed at a predetermined distance from one end, and a metal pin with a through-hole stopper attached thereto is inserted into a through hole provided in the ground pattern from the component mounting surface side, with the elastic metal contact part first. Insert and penetrate the through hole to the stopper,
The elastic metal contact portion is brought into contact with a metal lid on the component mounting side of the printed board, and the other end is held by the conductive metal pin holding portion to ground the printed board to the metal case. .

[Industrial application field]

The present invention relates to a method for grounding a microwave circuit used in a microwave radio device having a frequency up to about 2 Gllz, for example.

Generally, a microwave circuit used at a frequency of about 2 GHz or less is formed on a printed circuit board and housed in a metal case with a metal lid. At this time, in order to faithfully bring out the electrical characteristics of the microwave circuit, it is necessary to ensure that sufficient grounding can be achieved at any position on the printed board.

[Conventional technology]

FIG. 4 is an example of a printed board mounting diagram. FIG. 4(a) is a sectional view taken along line AA' in FIG. 4(b), FIG. 4(b) is a perspective view of the component mounting surface of the printed board, and FIG. FIG. 4(C) is a perspective view of the pattern surface of the printed board, and FIG. 4(d) is a view of the through-hole portion of the pattern surface.

Generally, the printed board 11 is composed of a component mounting surface on which components are mainly mounted and a pattern surface on which a pattern is mainly formed, as shown in FIG. 4(a).

The component mounting surface is the surface on which components 1 such as hybrid ICs, l-transistors, resistors, coils, etc. are mounted, as shown in FIG. A pattern 15 is formed.

Further, the surface opposite to the component mounting surface is a patterned surface as shown in FIGS. 4(C) and 4(d), and a signal pattern 14 is formed in a part thereof. This signal pattern has a grounding pattern formed on the back side and has an impedance of 1, for example 5.
It is 0Ω. Note that a chip component 13 such as an amplifier is connected to this signal pattern.

Note that the ground pattern on the component mounting surface of the printed board 11 and the ground pattern on the pattern surface are connected via a plurality of through holes 12.

Now, the microphone η wave circuit formed on the printed board as shown in FIGS. 4(a) to 4(d) is shown in FIG. 5(a).

As shown in FIG. 5 (■), all or a part of the periphery of the printed board 11 and the inside of the metal case 17 are soldered 18L to bring the printed board and the metal case into contact to establish grounding.

At this time, at B° near the center of the printed board, the distance from the contact portion with the metal case is longer than the distance from B, for example. Further, as shown in FIG. 5(C), when the arrangement and mounting density of components is increased, signal patterns and power supply patterns are formed, and there are cases where ground patterns are almost impossible to remove.

[Problem to be solved by the invention]

Here, the distance from B on the printed board to the contact part of the metal case is short, so sufficient grounding can be achieved, but the distance between B° near the center of the printed board and the contact part of the metal case is long, so Bo A potential difference occurs between the contact parts and the grounding becomes incomplete.

Furthermore, when the grounding pattern is almost impossible to obtain, the grounding is also incomplete.

That is, there is a problem in that it is difficult to obtain sufficient grounding at any arbitrary position on the printed board.

In this case, the electrical performance of the microwave circuit cannot be fully exploited.

An object of the present invention is to enable sufficient grounding at any position on the printed board when a microwave circuit is formed on the printed board.

[Means to solve problems] FIG. 1 shows a block diagram of the principle of the present invention.

4 is a conductive metal pin holding part that is fixed to the metal lid on the pattern side of the printed board; 3 is a metal rod having a diameter that can pass through the through hole; and at least one elastic metal contact part at one end of the metal rod; These are metal pins with through-hole stoppers attached at predetermined distances from each other.

Then, a metal pin is inserted into a through hole provided in the ground pattern on the pattern surface and penetrated to the through hole stopper. 1. The elastic metal contact portion is brought into contact with the metal lid on the component mounting surface side of the printed board. At the same time, the other end is held by the conductive metal bottle holding portion to ground the printed board to the metal case.

[Effect]

In the present invention, the conductive metal bottle holding portion 4 is fixed to the metal lid 22 on the pattern side of the printed board.

Further, a metal pin 3 has at least one elastic metal contact portion 33 attached to one end of a metal rod 31 having a diameter that can pass through a through hole 12 provided in a printed board, and a through hole stopper 32 attached at a predetermined distance from the one end. Prepare.

Then, insert a metal pin into the through hole provided in the ground pattern and pass it through to the through hole stopper, hold the other end in the conductive metal bottle holding part, and connect the elastic metal contact part to the high mounting surface side. contact with the metal lid.

Thereby, the printed board can be grounded to the metal case at any through-hole location within the grounding pattern.

〔Example〕

FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a diagram showing an example of the shape of the elastic metal contact portion in FIG. 2. Here, the conductive sponge 41 represents a component of the conductive metal bottle holding portion. Note that the same reference numerals indicate the same objects throughout the figures. The operation shown in FIG. 2 will be explained below with reference to FIG.

First, a conductive sponge 41 of a predetermined thickness is adhered to the entire surface of the metal lid 22 facing the printed board pattern surface using a conductive adhesive.

In addition, one end of a metal rod 31 having a diameter smaller than the diameter of the through hole 12 (the inner surface of the hole is covered with a conductive layer) provided in the printed surface is provided with a spring-like structure as shown in FIG. 3(a). A metal pin is made by attaching a perforated disc having a diameter larger than the diameter of the through hole to a certain rectangular metal piece 331 at a position D from one end as a through hole stopper 32.

Note that the rectangular metal piece 331 mentioned above is the elastic metal contact portion 3.
This is an example of No. 3.

Then, when a metal pin is inserted into an arbitrary through hole 12 provided in the ground pattern and penetrated to the through hole stopper, the other end of the metal pin sticks into the conductive sponge 41, so it can be easily connected to the metal M22. Can be contacted.

Further, the rectangular metal piece 331 is pressed against the metal lid 21, making the contact more complete.

Examples of other metal pin shapes include a hollow cylindrical one in which the upper part of the elastic contact part is divided into four rectangular metal pieces and the lower part is a common hollow cylindrical piece, as shown in FIG. 3(b); There is a bent metal rod 333, but in any case, the contact between the metal pin and the metal lid 21 is more complete.

Furthermore, by surrounding the device etc. with metal pins at an interval shorter than the wavelength, it becomes possible to shield the device etc.

That is, when a microwave circuit is formed on a printed board, sufficient grounding can be achieved at any position on the printed board.

〔Effect of the invention〕

As explained in detail above, according to the present invention, when a microwave circuit is formed on a printed board, sufficient grounding can be achieved at any position on the printed board.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a configuration diagram of an embodiment of the present invention, Fig. 3 is an example of the shape of the metal pin in Fig. 2, Fig. 4 is an example of a printed board mounting diagram, FIG. 5 shows a configuration diagram of a conventional example. In the figure, 3 is a metal pin, 4 is a conductive metal pin holding part, 11 is a printed board, 12 is a through hole, 17 is a metal case, 21 and 22 are metal lids, (t)n' II 2 U tP f) && e://)1
9Jc (3711vI 3 Illustration Kneeling O Roasted Example/) Item 8 Illustration Me 2 Note α)

Claims (1)

[Claims] A printed board (11) on which a microwave circuit is formed and a through hole (12) is provided between the component mounting surface and the pattern surface is made of metal with a metallic lid (21, 22). When housing the printed board in the case (17) and grounding the printed board to the metal case, fix the conductive metal pin holding portion (4) to the metal lid (22) on the pattern side of the printed board. , at least one elastic metal contact portion (33) at one end of the metal rod (31) having a diameter that can pass through the through hole;
A through-hole stopper (3
2) respectively attached to the metal pins (3) are inserted into the through holes provided in the grounding pattern from the component mounting surface side, with the elastic metal contact portion first, and penetrated to the through hole stopper, and the elastic metal The contact portion (33) is brought into contact with the metal lid (21) on the component mounting side of the printed board, and the other end is held by the conductive metal pin holding portion (4) to place the printed board in the metal case. A microwave circuit grounding method characterized by grounding.