JPH0611601Y2 - Terminal structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a terminal structure of a dielectric filter used in a high frequency band such as microwave, and more specifically, a flange of a synthetic resin member surrounding a part of a conductor pin. The present invention relates to a terminal structure in which a portion is formed into an inverted pyramid shape and a projection portion which is continuous to the portion is provided to facilitate frequency adjustment and positioning of an earth metal fitting.

[Prior Art] A filter using a dielectric ceramic is conventionally known,
It is widely used in fields such as mobile radio such as car phones or satellite communication.

As a conventional dielectric filter, for example, as shown in FIG. 4, a sintered dielectric block 10 having a substantially rectangular parallelepiped shape.
Multiple (3 in the figure) with a predetermined interval in the longitudinal direction of
Of the resonator holes 12 and the connector holes 14 are alternately arranged, and one of the surfaces (the upper surface in the same figure) where the resonator holes 12 and the connector holes 14 are open is an open surface, and the other parts are excluded. The conductor layer 16 is formed on the surface and the inner surface of the resonator hole 12 by metallization or the like.
There is a structure that formed. Here, each resonator hole 12 serves as a resonance element having a resonance wavelength four times its length.

The input / output terminal 20 of the dielectric filter has a structure in which a conductor pin 22 serving as an inner conductor is located at the center and a part of the conductor pin 22 is surrounded by a synthetic resin member 24. The synthetic resin member 24 is composed of a cylindrical insertion portion 24a into the resonator hole 12 and a flange portion 24b which serves as a stopper when inserted. Such an input / output terminal 20 is manufactured by integrally molding a synthetic resin with a conductor pin, or by molding only the synthetic resin into a predetermined shape and then press-fitting the conductor pin 22.

Then, by inserting the cylindrical insertion portion 24a into the resonator holes 12 located at both ends of the dielectric block, the mounting of the input / output terminal 20 is completed.

[Problems to be Solved by the Invention] Since the dielectric block 10 is a ceramic sintered body, the dielectric constant and outer dimensions of the final product or the inner diameter of the resonator hole 12 may vary to some extent depending on the manufacturing conditions of the material. Are inevitable, and they deviate from the resonance frequency. When the input / output terminal 20 is attached to the resonator hole 12, the resonance frequency shifts due to stray capacitance or the like.

Therefore, for example, a pattern conductor for frequency adjustment, which is continuous with the conductor layer on the inner surface, is formed on the open end side of the resonator hole 12, and the resonance frequency is adjusted by scraping it off.

However, if the flange portion 24b of the synthetic resin member 24 is disc-shaped as in the prior art, the lower surface of the flange portion 24b comes into close contact with the open surface after the input / output terminal 20 is inserted, so that part of the pattern conductor is formed. Is hidden, the adjustable range is narrowed, and in extreme cases, the frequency cannot be adjusted by scraping.

Further, in this case, a metal plate is used as the grounding metal fitting, which is bent into an inverted U shape so as to cover the open surface and has the grounding terminal protruding so that the resonance frequency can be adjusted even after the grounding metal fitting is attached. With such a structure, alignment becomes difficult at the time of mounting, and it becomes impossible to mount it on a printed circuit board due to misalignment or damage such as terminal damage occurs.

The object of the present invention is to eliminate the drawbacks of the prior art as described above, to facilitate the adjustment of the resonance frequency of the dielectric filter by scraping the pattern conductor, and to widen the adjustment range, and to improve the assembly accuracy and print. It is to provide a terminal structure that can be easily mounted on a substrate.

[Means for Solving the Problems] In the present invention which can achieve the above-mentioned object, a terminal having a structure in which a part of a conductor pin is surrounded by a synthetic resin member is provided.
In a terminal structure to be inserted into a resonator hole formed in a dielectric block, in the vicinity of an end of the resonator hole into which the terminal is inserted, which is on the open surface of the dielectric block, and which is continuous with a conductor layer on the inner surface of the resonator hole. A pattern conductor for frequency adjustment is provided, and the synthetic resin member of the terminal has a shape in which a columnar insertion portion into the resonator hole, an inverted cone-shaped flange portion, and a positioning protrusion of the grounding metal member are continuously integrated. This is the terminal structure used.

Here, the flange portion provided on the synthetic resin member may have an inverted conical shape, an inverted pyramid shape, or the like.

[Operation] When the flange portion of the synthetic resin member that surrounds a part of the conductor pin is formed into an inverted cone shape, the entire frequency-adjusting pattern conductor formed on the open surface of the dielectric block is completely formed even after the input / output terminals are mounted. It is exposed and can be adjusted sufficiently by scraping. That is, the adjustment work becomes easy and the adjustable range is widened.

Further, since the protrusion is formed on the synthetic resin member,
By doing so, the inverted U-shaped grounding metal fitting can be positioned, the relative position of the conductor pin of the input / output terminal and the grounding terminal of the grounding metal fitting is determined, and mounting on a printed circuit board or the like becomes easy, and due to misalignment, etc. It is possible to prevent the occurrence of failures such as terminal damage that often occur.

[Embodiment] FIG. 1 is an exploded perspective view showing an example of a dielectric filter using a terminal according to the present invention, FIG. 2 is a perspective view after assembly thereof, and FIG. 3 is a sectional view thereof. In this embodiment, the present invention is applied to a three-stage filter.

The basic structure of the dielectric filter is similar to that of the conventional technique described in FIG. A rectangular parallelepiped dielectric block 10 made of a sintered body of a high dielectric constant ceramic material such as barium titanate.
3 resonator holes 12 are formed in the longitudinal direction of the dielectric block 10 at intervals, and a connector hole 14 is provided between the resonator holes 12, so that all side surfaces and the bottom surface of the dielectric block 10 and the resonator hole 12 are formed. In this structure, the conductor layer 16 is formed on the inner surface by metallization. The conductor layer 16 serves as an outer conductor, and the upper surface of the dielectric block 10 serves as an open surface. Then, the frequency adjustment pattern conductor 18 is formed on this open surface. The pattern conductor 18 is electrically connected to the metallized layer formed on the inner surface of the resonator hole 12, and is provided so as to spread toward both ends. The pattern conductor 18 is formed in the same process as the other conductor layer by metallization by a method such as screen printing.

In FIGS. 1 and 2, the portions (open surfaces) where the base of the dielectric material is exposed as it is without metallization are shown with fine dots. Further, in FIG. 3, the conductor layer 16 formed by metallization is drawn to have a considerable thickness for the sake of easy understanding of the drawing, but it is actually an extremely thin layer formed by baking a silver paste or the like.

Input / output terminals 30 for coupling with an external circuit are inserted into the resonator holes 12 at both ends of the dielectric block 10. The input / output terminal 30 has a structure in which a conductor pin 32 serving as an inner conductor is located at the center and a part of which is surrounded by a synthetic resin material 34.

The present invention is significantly different from the prior art in the structure of the synthetic resin portion 34. The synthetic resin member 34 has a resonator hole 1
The columnar insertion portion 34a into the second member 2, the inverted pyramid-shaped flange portion 34b, and the positioning projection portion 34c of the grounding metal fitting are continuously integrated. The flange portion 34b may have an inverted conical shape or an inverted pyramid shape.

Then, as shown in FIGS. 2 and 3, the insertion portion 34a is press-fitted from the open surface side so that the insertion portion 34a enters the resonator hole 12. When the flange portion 34b of the synthetic resin member 34 is formed in an inverted cone shape in this manner, the frequency adjusting pattern conductor 1 formed on the open surface of the dielectric block 10 even after the input / output terminal 30 is mounted.
The whole 8 is completely exposed, and it is possible to make adjustments by sufficient scraping. That is, the adjustment work becomes easy and the adjustable range is widened.

An earth metal fitting 40 is attached to the open surface of the dielectric block 10 so as to cover it. This earth metal fitting 40
Is a structure in which a metal plate is punched into a predetermined shape and bent into an inverted U shape. The ground terminals 40a project upward at the four corners, and the central flat portion 40b has a short length and projections of the synthetic resin member 34 at both ends thereof. Notch 40 that exactly fits the portion 34c
c is provided. Such an earth metal fitting 40 is the second
As clearly shown in the figure, the notch 40c is aligned with the protrusion 34c, and the side walls 40 are aligned.
At d, it is connected and fixed to the outer conductor layer 16 of the dielectric block 10 by soldering or the like.

Therefore, even after the ground metal fitting 40 is attached, the frequency adjusting pattern conductor 18 can be approached from both ends and fine adjustment is possible. Since it is positioned in the longitudinal direction (the direction indicated by the arrow X) by the engagement of the projection 34c and the notch 40c, it does not move, and the relative position between the conductor pin 32 and the ground terminal 40a is always constant. . As a result, mounting on a printed circuit board or the like becomes easy, and it is possible to eliminate the drawbacks of the conventional technique in which the conductor pin and the ground terminal are damaged by the forced mounting even if there is a displacement.

The above embodiment is an example in which the present invention is applied to a filter having a three-stage structure, but the present invention can be applied to any dielectric filter having two or more stages. Further, it goes without saying that the present invention can also be applied to a dielectric filter or the like in which a coupling degree is adjusted by a pattern conductor without providing a coupling hole between the resonator holes.

[Effects of the Invention] As described above, the present invention has the flange portion of the synthetic resin member that surrounds a part of the conductor pin in the shape of an inverted cone, so that when inserted into the resonator hole formed in the dielectric block, The frequency adjustment pattern conductor formed so as to be continuous with the conductor layer on the inner surface of the resonator hole is completely exposed up to the vicinity of the hole end, and adjustment work by scraping can be easily performed and adjustment is possible. The effect of widening the range is produced. Of course, it goes without saying that the flange portion can function as a stopper to prevent the synthetic resin member from slipping into the resonator hole.

Further, in the present invention, since the protrusion is provided continuously on the flange portion, the positioning with respect to the ground metal fitting is facilitated, and the relative positional accuracy between the ground terminal and the conductor pin can be improved. As a result, it is easy to mount on a printed circuit board or the like, and it is possible to prevent the occurrence of troubles such as damage to the conductor pin or the ground terminal due to excessive force due to displacement or the like.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an example of a dielectric filter using terminals according to the present invention, FIG. 2 is a perspective view after assembly thereof, FIG. 3 is a sectional view thereof, and FIG. 4 is an example of prior art. It is an exploded perspective view showing. 10 ... Dielectric block, 12 ... Resonator hole, 14 ...
Connector hole, 16 ... Conductor layer, 30 ... Input / output terminal, 32
...... Conductor pin, 34 …… Synthetic resin member, 34a …… Column insertion part, 34b …… Inverse cone shaped flange part, 34c …… Positioning projection part, 40 …… Ground metal fitting.

Claims (1)

[Scope of utility model registration request] 1. A terminal structure in which a terminal having a structure in which a synthetic resin member surrounds a part of a conductor pin is inserted into a resonator hole formed in a dielectric block, and the terminal on the open surface of the dielectric block is inserted. A pattern conductor for frequency adjustment, which is continuous with the conductor layer on the inner surface of the resonator hole, is provided in the vicinity of the end of the resonator hole, and the synthetic resin member of the terminal includes a columnar insertion portion into the resonator hole and an inverted cone. The terminal structure has a shape in which the ring-shaped flange and the protrusion for positioning the ground metal fitting are continuously integrated.