JPH0722885Y2 - Stripline filter package structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a package structure of a stripline filter used as a filter of a microwave band or a millimeter wave band.

[Prior Art] Generally, a waveguide filter, a dielectric filter, a stripline filter, or the like is used as a microwave band or millimeter wave band filter.

A schematic perspective view of a stripline filter element which is the background of the present invention is shown in FIG. The stripline filter element 1 includes a full surface electrode 3 formed on one main surface of a dielectric substrate 2 and resonance electrodes 4 to 8 formed on the other main surface. Full-surface electrode 3 is formed to extend from one main surface of dielectric substrate 2 to the other main surface through the side surface thereof. And the resonance electrodes 4 to 8
Have their one ends commonly connected to this full-surface electrode 3. That is, the resonance electrodes 4 to 8 are arranged so as to extend in parallel from one end of the entire surface electrode 3. Such resonance electrodes 4 to 8 are formed by printing after using a conductive material such as silver and printing. Each resonance electrode 4-8
It is configured as a 1/4 wavelength, and therefore, the end portion on the entire surface electrode side is a short-circuited end, that is, the voltage standing wave is zero. Therefore, the dimension A in Fig. 4 is 1 /
Selected to correspond to four wavelengths. The full-surface electrode 3 does not necessarily need to be formed to extend to a part of the other main surface, but is formed only on one main surface and the side surface, and each end of the resonance electrodes 4 to 8 extends to the side surface. Alternatively, it may be connected to the entire surface electrode. However, in reality, the length A of the resonance electrodes 4 to 8 may be different from the predetermined value (design value) due to the deviation of the pattern printing. Therefore, as shown in FIG. Is preferably extended to the other main surface. These resonance electrodes 4
The inter-spacing of ~ 8 determines the pass (or stop) bandwidth of this stripline filter element 1.

Further, external lead-out electrodes 11 and 12 acting as input / output electrodes are formed on the electrodes at the ends of the arrayed resonant voltages 4 to 8, that is, 4 to 8, respectively.

Conventionally, the stripline filter element 1 having the above-described structure has a package structure as shown in FIGS. 5 and 6, for example.

That is, the stripline filter element 1
The external lead electrodes 11 and 12 are soldered to the input / output lead terminals 13 and 14, respectively, and the entire surface electrode 3 is soldered to the ground lead terminals 15 and 16 to be supported on the fixed substrate 17. To be done. The fixed substrate 17 is made of an insulating resin, and the lead terminals 13 to 16 are integrally penetrated and fixed to the fixed substrate 17 by insert molding.
The fixed substrate 17 is fitted into the metal case 18 having an open end from the fixed side of the stripline filter element 1, and is fixed to the opening of the metal case 18 with an adhesive or the like.

[Problems to be Solved by the Invention] In the stripline filter having the package structure as shown in FIGS. 5 and 6, the external extraction electrodes 11 and 12 and the lead terminals 13 and 14 of the stripline filter element 1 are connected to each other. The soldering positions of 1) and the soldering positions of the whole surface electrode 3 and the lead terminals 15 and 16 are not always constant.
Therefore, the distance between the stripline filter element 1 and the metal case 18 varies in various values, which affects the electromagnetic field of the signal propagating through the stripline filter element 1. As a result, the characteristics of the stripline filter change, and it is difficult to obtain a stripline filter having a characteristic within a certain allowable range, and there is a problem that the mass productivity of the stripline filter is not good.

An object of the present invention is to provide a package structure of a stripline filter which has stable filter characteristics and is free from leaks in the electrode field and has good mass productivity.

[Means for Solving the Problems] Therefore, according to the present invention, a stripline filter element in which a resonance electrode and a full-scale electrode are respectively formed on opposite main surfaces of a dielectric substrate, and the stripline filter element, From a one-end opening-shaped metal case that is housed with a space between the one-end opening and the inner surface, and a low dielectric constant material that fits into the one-end opening of the metal case and is fixed at a fixed position. The fixed frame is characterized in that the stripline filter element is inserted substantially perpendicularly to the fixed frame, and has a fixed hole that is fixed to the fixed frame at a fixed position. .

[Operation] When the stripline filter element is fixed to the fixed frame and the fixed frame is fixed to the metal case, the stripline filter element is positioned with respect to the metal case. As a result, the storage capacitance between the stripline filter element and the metal case becomes constant, and variations in the characteristics of the stripline filter are eliminated.

[Advantages of the Invention] According to the present invention, since the stripline filter element is fixed at a fixed position in the metal case by the fixing frame made of the low relative dielectric constant material, the stress between the stripline filter element and the metal case is increased. The capacitance becomes constant, the characteristic of the stripline filter does not vary, and the mass productivity of the stripline filter is improved.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

An exploded perspective view and a longitudinal sectional view of an embodiment of a stripline filter package structure according to the present invention are shown in FIGS. 1 and 2, respectively.

The stripline filter package structure described above is different from the stripline filter package structures shown in FIGS. 5 and 6 in that it includes a fixing frame 21 that is fitted into one end opening of the metal case 18 and fixed at a fixed position. Fixed frame 21
The stripline filter element 1 is vertically inserted into and fixed to the fixing frame 21 in the fixing hole 22 formed in the above.

In FIGS. 1 and 2, parts corresponding to those in FIGS. 5 and 6 are designated by the corresponding reference numerals, and a duplicate description will be omitted.

The fixed frame 21 is made of a low dielectric constant material such as ceramics and has a substantially constant thickness, and has a shape and dimensions that can be fitted into the opening of the metal case 18. Then, the fixed frame 21 is positioned with respect to the metal case 18 by a ridge 23 formed at a position equal to the thickness of the fixed frame 21 inward from the opening end of the metal case 18.

In the fixing hole 22 of the fixing frame 21, the lead terminals 13 and 14 are respectively provided to the external extraction electrodes 11 and 12, and the lead terminal 1 is provided to the entire surface electrode 3.
The stripline filter element 1, to which 5 and 16 are soldered, is inserted and fixed. Therefore, in the fixing hole 22, the grooves 24, 25, into which the lead terminals 13 to 16 are fitted,
26 and 27 are formed. The stripline filter element 1 has lead terminals 13-16.
From the pull-out side, the insertion amount equal to the thickness of the fixed frame 21 is inserted into the fixed hole 22, and is vertically fixed to the fixed frame 21.

With such a configuration, the fixed frame 21 is positioned with respect to the metal case 18 by the protrusion 23 of the metal case 18.
Further, the stripline filter element 1 is fixed at a fixed position with respect to the fixed frame 21 when fixed to the fixed frame 21. As a result, the stripline filter element 1 is fixed at a fixed position with respect to the metal case 18, the storage capacitance between the stripline filter element 1 and the metal case 18 is also constant, and variations in the characteristics of the stripline filter are caused. Disappear. Further, since the fixed frame 21 is made of a material having a low relative dielectric constant, even if the stripline filter element 1 is directly fixed to the fixed frame 21 as described above, the electrical characteristics of the stripline filter are Almost no impact.

In the embodiment described above, for example, as shown in FIG. 3, if the lead terminals 13 to 16 are pulled out to the end surface of the fixed frame 21 along the main surface inside the metal case 18 of the fixed frame 21, It is possible to obtain a so-called surface mount type stripline filter that can be directly mounted on the pattern surface of the printed circuit board. However, in the strip line filter of FIG.
In order to prevent electrical contact between 16 and the metal case 18, a cutout 28 is formed in the metal case 18 at a position where the lead terminals 13 to 16 are drawn out.

Although not specifically shown, in the stripline filter of FIG. 3, the entire surface electrode 3 of the stripline filter element 1 is directly connected to the metal case 18, and the metal case 18 is provided with a grounding terminal. Good.

[Brief description of drawings]

1 and 2 are an exploded perspective view and a longitudinal sectional view, respectively, of a package structure of a stripline filter according to the present invention, and FIG. 3 is a modification of the package structure of the stripline filter of FIGS. 1 and 2. Partially broken perspective view, FIG. 4 is a perspective view of a stripline filter element, and FIGS. 5 and 6 are an exploded perspective view and a longitudinal sectional view showing a conventional stripline filter package structure, respectively. 1 ... Stripline filter element, 2 ... Dielectric substrate, 3 ... Full surface electrode, 4-8 ... Resonant electrode, 18 ...
… Metal case, 21 …… Fixed frame, 23 …… Fixed hole, 23 …… Ridge.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-262301 (JP, A) Actually opened 56-105901 (JP, U) Actually opened 56-96704 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A stripline filter element having a resonant electrode and a full-scale electrode formed on opposite main surfaces of a dielectric substrate, respectively, and the stripline filter element is provided with a space between an opening at one end and an inner surface. A metal case having an opening at one end that is housed therein is provided, and a fixing frame made of a low relative dielectric constant material that is fitted into the opening at one end of the metal case and fixed at a fixed position. A stripline filter package structure, wherein a stripline filter element is inserted substantially perpendicularly to the fixed frame and has a fixing hole fixed to the fixed frame at a fixed position.