JPS635138Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a high frequency switching device used for switching high frequency signals.

As is well known, since a normal signal changeover switch is used to switch high frequency signals, a reduction in isolation between transmission lines and generation of unnecessary radiation from the switch itself are unavoidable.

For this reason, a coaxial switch has been developed in which the entire housing housing the switch mechanism has a shield structure, that is, is made of metal.

However, in the above-mentioned housing, the material cost of the housing is of course high, and the manufacturing process must depend on cutting.
The problem was that not only was the molding process time-consuming, but the maintenance and management costs for the cutting tools were also high.

Therefore, instead of being made of metal like this,
It is conceivable that the case is formed of resin or ceramic, and that an external conductor layer is formed on the outer circumferential surface of the case and on the outer circumferential surface of the terminal protrusion formed integrally with the case. However, in this case, during soldering work, the soldering iron, which is usually around 260℃, is pressed for the required time (usually 3 to 10 seconds), which softens the resin and ceramic, causing some of it to gasify and expand. Therefore, there is a drawback that the outer conductor layer ruptures and deforms and loses its function as a terminal.

The object of this invention is to provide a high-frequency switching device that eliminates such inconveniences such as rupture and deformation of the outer conductor layer of the terminal protrusion during soldering work.

An embodiment in which this invention is applied to a high frequency electromagnetic relay will be described below with reference to the drawings.

FIG. 1 is a plan view showing a high frequency electromagnetic relay, and FIG. 2 is a cross-sectional view taken along line A-A in FIG.
FIG. 3 is a schematic exploded perspective view.

The housing is composed of a box-shaped case 1 and a cover 2 made of synthetic resin such as ABS or ceramic. This case 1 is provided with a recess 1a for accommodating a contact circuit section, which will be described later, and a recess 1f for accommodating an electromagnet section, etc. Furthermore, a terminal protrusion 6 protrudes integrally with the case 1 on the outer peripheral surface. It is formed. At least the entire inner circumferential surface of the recess 1a, the outer surface of the terminal protrusion 6 other than the tip surface, and the outer circumferential surface of the case 1 are covered with the outer conductor layer 1c (FIGS. 4 and 5). reference). This outer conductor layer 1c is formed by plating, specifically, first by plating electroless nickel or electroless copper.
Forming a thin uniform coating 1c1 of about 0.2 to 0.5 μm,
On this coating 1c1, a metal coating 1c2 is formed by plating, such as electrolytic nickel, which has good solderability. As shown in FIG. 5A, this outer conductor layer 1c is formed on the entire outer surface including the tip end surface of the terminal protrusion 6, but the tip is later cut to form the outer conductor layer 1c.
c is removed so that only the tip end surface is not covered with the outer conductor layer 1c, as shown in FIG. 5B.

Dielectric blocks 3d, 4d, 5d made of synthetic resin are fitted into the recess 1a of the case 1, and three rod-shaped fixed terminals 3, 4, 5 are held by these dielectric blocks 3d, 4d, 5d. is concave part 1
on the central axis of a, and its contact portion 3
a, 4a, 5a are inside the case 1, terminal parts 3b, 4
b, 5b are fixed so as to protrude outside the case 1. As a result, a coaxial structure is constructed in which the fixed terminals 3, 4, and 5 serve as center conductors, and the outer conductor layer 1c formed on the inner peripheral surface of the insertion hole of dielectric blocks 3d, 4d, and 5d serves as an outer conductor.

The cards 9 and 10 are slidably supported by guide grooves 1d and 1e formed in the case 1, and movable contact pieces 11 and 12 are fixed approximately at the center of the cards 9 and 10, respectively. Both ends of the movable contact piece 11 are contactably opposed to the fixed terminals 3 and 4, and both ends of the movable contact piece 12 are contactably opposed to the fixed terminals 4 and 5. Further, the contact portions 11a, 11 of the movable contact pieces 11, 12
Four ground contact portions 1b, . . . 1b are formed on the side wall of the recessed portion 1a of the case 1 facing the movable contact portions 1b, 12a, 12a.
By forming the outer conductor layer 1c on the surface of the case 1 as described above, the earth contact portion 1b is formed into a protruding shape at a protrusion formed on the side wall of the recess 1a, as shown in an enlarged view in FIG. It is something that can be done.

An electromagnet consisting of an iron core 14, a coil 15, a spool 16, a yoke 17, a movable iron piece 18, and a return spring 19 is fixed in the recess 1f of the case 1. The return spring 19 is clamped at its base by the yoke 17 and the protruding portion 1g of the case 1, and the movable iron piece is pressed by pressing the pressing piece 19a at the free end against the movable iron piece 18 which is hingedly supported on the yoke 17. A restoring force is applied to 18. Both ends of the connecting plate 20 are fitted into the holes 9a and 10a of the cards 9 and 10, so that the cards 9 and 10 are interlocked. A hole 21a is formed in the center of the spring plate 21, and openings 21b, 21b are formed on both sides of the hole 21a. death,
It is held in the case 1 by pressing its both ends against the protrusions 1h, 1h on both sides of the case 1 so as to bend the entire body.

Next, the operation of the high frequency electromagnetic relay constructed as described above will be explained.

When the coil 15 is de-energized, the movable iron piece 18 is in the return position as shown in FIG.
is urged upward by the spring force of the spring plate 21 transmitted via the connecting plate 20. Therefore, both ends of the movable contact piece 11 are in contact with the ground contact portions 1b, 1b of the recess 1a, and the fixed terminals 3,
4 rooms are in open state. Further, the movable contact piece 12 has its contact portions 12a, 12a in contact with the contact portions 4a, 5a of the fixed terminals 4, 5.
The space is closed.

When the coil 15 is energized in this state, the movable iron piece 18 rotates clockwise and presses the connecting plate 20 downward against the spring force of the spring plate 21. As the connecting plate 20 descends, the cards 9 and 10 also descend, and the contact portions 11a and 11a of the movable contact piece 11 are connected to the contact portions 3a and 4a of the fixed terminals 3 and 4, and the contact portions 12a and 12a of the movable contact piece 12 are connected to the contact portions 3a and 4a of the fixed terminals 3 and 4, respectively. 12a contacts the ground contact portions 1b, 1b of the recessed portion 1a, respectively. Therefore, the fixed terminals 3 and 4 are closed, and the fixed terminals 4 and 5 are opened. And coil 15
When the energization is stopped, the movable iron piece 18 is returned to its initial position by the spring force of the return spring 19, and the cards 9 and 10 are returned to their initial positions by the spring force of the spring plate 21.

Here, since the case 1 is made of resin or ceramic and the outer conductor layer 1c is formed on the inner and outer peripheral surfaces of the case 1, the high frequency current is concentrated on the outer conductor layer 1c, and a so-called skin effect appears. Not only can the isolation between signals be improved, but the material cost is also lower than when the housing is molded from a metal material, and the molding process is easier.

In particular, since the outer conductor layer 1c is formed after the terminal protrusions 6 are integrally formed in the case 1, there is no need to separately provide the terminal protrusions 6, and the number of manufacturing steps is reduced.

Furthermore, when the fixed terminals 3, 4 or 4, 5 are in an open state, the movable contact piece 11 or 12 comes into contact with the ground contact portion 1b and is grounded, so that a high frequency signal is transmitted to the movable contact piece 11 or 12. There is no risk of leakage through the fixed terminals 3, 4 or 4, 5 causing a closed state at high frequencies due to electrostatic coupling, and high isolation can be obtained.

Furthermore, the terminal protrusion 6 serves as a ground terminal, and will be soldered to a conductor pattern on a printed circuit board later without any problem. That is, soldering work is usually done by pressing a solder or iron at around 260°C for the required time (usually 3 to 10 seconds). Then, the resin forming the terminal protrusion 6 is softened, slightly gasified, and expanded. However, since this gas escapes from the tip surface where the outer conductor layer 1c is not provided, the outer conductor layer 1c is prevented from bursting and deforming, and does not lose its sufficient function as a conductive terminal.

In the above embodiment, the outer conductor layer 1c is formed by plating, but it may be formed by other means such as vapor deposition or painting. Furthermore, in order to avoid providing the outer conductor layer 1c on the tip surface of the terminal protrusion 6, the tip surface must not only be cut off afterwards, but also be coated from the beginning by plating, vapor deposition, painting, etc. Measures can also be taken to prevent this from happening.

As described above in the embodiments, the high frequency switch according to the present invention has a case housing the switch mechanism made of resin or ceramic, and a protrusion integrally formed on the outer circumferential surface of the case. At least the outer peripheral surface and the outer surface other than the tip surface of the protrusion are covered with an outer conductor layer, and the protrusion whose outer surface other than the tip surface is covered with the outer conductor layer is used as a grounding terminal. Therefore, it is inexpensive to manufacture and has excellent isolation characteristics. Furthermore, it is possible to prevent the outer conductor layer of the protrusion from being ruptured or deformed during soldering, and it is possible to obtain a grounding terminal that has a sufficient function as a conductive terminal.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view showing a high-frequency electromagnetic relay that is an embodiment of this invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 shows the main parts of this invention. Exploded perspective view; Figure 4 is an enlarged cross-sectional view of the vicinity of the ground contact; Figures 5A and B are enlarged views of the vicinity of the ground terminal; Figure 5A is the cross-section before cutting. Figure 5B is a sectional view after cutting. 1...Case, 1b...Earth contact part, 1c...
...Outer conductor layer, 2...Cover, 3, 4, 5... Fixed terminal, 6... Terminal protrusion, 11, 12... Movable contact piece, 11a, 12a... Contact portion.

Claims (1)

[Scope of utility model registration request] A case housing the switch mechanism is formed of resin or ceramic, and a protrusion is integrally formed on the outer circumferential surface of the case, and at least the outer circumferential surface of the case and the outer surface other than the tip surface of the protrusion are covered with an external conductor layer. A high frequency switching device characterized in that a protruding portion whose outer surface other than the tip surface is covered with an external conductor layer serves as a grounding terminal.