JPH0555604U - Dielectric filter - Google Patents

Abstract

(57) [Summary] [Object] To provide a dielectric filter capable of preventing the bonded substrate from being cracked by an external force at the time of assembly or the like and improving the reliability of quality. [Configuration] A coupling substrate 5 to which a plurality of resonators 3 are connected,
When the dielectric filter 1 is arranged on the grounding case 2a in a non-contact state via the spacer substrate 7 and the input and output terminals 6 are sandwiched between the coupling substrate 5 and the spacer substrate 7, The resin sheet 8 fills the gap between the combined substrate 5 and the spacer substrate 7.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a dielectric filter in which a plurality of resonators are capacitively coupled to each other via a coupling substrate on which a capacitor electrode is formed, and the resonator and the input and output terminals are coupled by an external capacitance. Particularly, the present invention relates to a structure that prevents the connecting base plate from being cracked by an external force at the time of assembling, so that the reliability of quality can be improved.

[0002]

[Prior Art]

 As an example of a dielectric filter using a plurality of dielectric coaxial resonators, there is conventionally one having a structure shown in FIGS. 4 and 5. This dielectric filter 1 is configured by arranging three dielectric coaxial resonators 3 in parallel in a metal case 2 composed of a grounding case plate 2a and a case cover 2b. A coupling terminal 4 is press-fitted into the resonator hole 3a of each dielectric resonator 3, and a part of the coupling terminal 4 projects outward. In addition, a strip-shaped coupling substrate 5 is arranged in front of each of the dielectric resonators 3 described above. Capacitor electrodes C are formed on the upper surface of the coupling substrate 5, and the protruding portions of the coupling terminals 4 are soldered to each electrode C. Further, on the lower surface of the coupling substrate 5, there are formed counter electrodes C'opposing each of the capacitor electrodes C with the substrate 5 sandwiched therebetween. Are connected by soldering. As a result, the dielectric resonators 3 are coupled to each other with the opposing capacitance, and the dielectric resonators 3 at both ends and the input and output terminals 6 are externally coupled with the opposing capacitance.

By the way, when the combined substrate 5 is arranged on the case plate 2a, the combined substrate 5 is supported in a floating state so that the electrode C'of the substrate 5 and the input / output terminals 6 do not come into contact with the ground plate 2a. There is a need to. For this reason, conventionally, a spacer base plate 7 made of glass epoxy, BT resin, alumina or the like having a small dielectric constant is provided between the case plate 2a and the coupling substrate 5 so as not to fall to the ground. The input / output terminals 6 are sandwiched and fixed by the board 7 and the connection board 5.

[0004]

[Problems to be solved by the device]

 However, in the above-described conventional dielectric filter 1, since a gap t is formed between the spacer substrate 7 and the coupling substrate 5 by the thickness of the input and output terminals 6, an external force is applied to the central portion of the coupling substrate 5 during assembly. If added, it is easily damaged or cracked, and the reliability of quality is low. Further, in the above-mentioned combined substrate 5, the area and the thickness of the combined substrate 5 are reduced by taking a capacitance between the electrodes C and C'which face each other with the substrate 5 sandwiched therebetween, so that the combined substrate 5 can be miniaturized. , It is even easier to crack.

Here, in order to eliminate the gap t between the two substrates 5 and 7, the spacer substrate 7 is shortened so that the spacer substrate 7 is brought into contact with only the central portion of the coupling substrate 5 excluding the connecting portions of the input and output terminals 6. It is possible to do it. However, in this case, since the input and output terminals 6 are in a floating state, when external force is applied to the terminals 6, there is a problem that they shift or peel off.

The present invention has been made in view of the above-mentioned conventional situation, and while securing the connection strength of the input and output terminals, preventing the bonded substrate from cracking during assembly, and improving the reliability of the quality. It is an object of the present invention to provide a dielectric filter capable of improving the above.

[0007]

[Means for Solving the Problems]

 Therefore, in the present invention, a coupling substrate to which a plurality of resonators are connected is arranged in a non-contact state on a case via a spacer substrate, and the coupling substrate has the input and output terminals sandwiched between the substrate and the spacer substrate. In the dielectric filter configured to be connected in step 1, the gap between the coupling substrate and the spacer substrate is filled with a resin sheet.

Here, it is preferable that the resin sheet has a dielectric constant of about 2 to 3 that does not affect the electrical characteristics, and has heat resistance to a reflow soldering temperature, for example, a polyimide sheet, Alternatively, it is desirable to use a PTFE sheet or the like.

[0009]

[Action]

 According to the dielectric filter of the present invention, since the gap between the coupling substrate and the spacer substrate is filled with the resin sheet, the gap due to the thickness of the input and output terminals can be eliminated, and the cracking of the coupling substrate at the time of assembly. And cracks can be prevented. As a result, the reliability of quality can be improved and the defective rate in mass production can be reduced. Further, in the present invention, since the input and output terminals are sandwiched and fixed by both boards, the input and output terminals will not be displaced even if an external force is applied, and the connection strength can be improved. Can be improved.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 are views for explaining a dielectric filter according to an embodiment of the present invention, in which the same reference numerals as those in FIGS. 4 and 5 denote the same or corresponding portions. The dielectric filter 1 of this embodiment is configured by arranging three dielectric coaxial resonators 3 in parallel in a metal case 2 composed of a grounding case plate 2a and a box-shaped case cover 2b. In each of the dielectric coaxial resonators 3, a resonator hole 3a is formed so as to penetrate the axis of a rectangular parallelepiped dielectric block 3b, and the inner peripheral surface of the resonator hole 3a and the outside of the dielectric block 3b. The structure is such that a conductive film is formed on each part of the surface except the open side end face 3c.

Further, a cylindrical coupling terminal 4 is press-fitted into the resonator hole 3a of each dielectric resonator 3, and a part of the coupling terminal 4 projects from the open side end surface 3c. Further, a coupling substrate 5 is arranged in front of the dielectric resonator 3, and the projecting portions of the coupling terminals 4 are soldered to the upper surface of the coupling substrate 5 for each capacitor electrode C. .. As a result, the dielectric resonators 3 are capacitively coupled to each other.

Further, one end of the input / output terminal 6 is soldered to the counter electrode C ′ on the lower surface of the coupling substrate 5, and the other end of each input / output terminal 6 is connected to the case cover 2 b. From the opening 2c. As a result, the dielectric resonator 3 and the input / output terminals 6 on both ends are capacitively coupled to an external circuit. The case plate 2a and the case cover 2b are mechanically and electrically connected to the dielectric resonator 3 by the solder filled in the solder holes 2d.

A spacer substrate 7 is arranged between the case plate 2 a and the combined substrate 5. The spacer substrate 7 is in the form of a strip having substantially the same length and width as the combined substrate 5, and the spacer substrate 7 is fixed to the case plate 2a with an adhesive or the like. The joint substrate 5 is arranged on the case plate 2a in a non-contact state via the spacer substrate 7, and one end of the input / output terminal 6 is sandwiched between the spacer substrate 7 and the joint substrate 5. Has been done.

A resin sheet 8, which is a feature of this embodiment, is arranged in the gap between the spacer substrate 7 and the combined substrate 5. The resin sheet 8 is made of a polyimide sheet or a PTFE sheet having a dielectric constant of about 2 to 3, and the thickness of the resin sheet 8 is set so as to fill the gap corresponding to the thickness of the input and output terminals 6. There is.

Next, the function and effect of this embodiment will be described. According to the dielectric filter 1 of this embodiment, the coupling substrate 5 and the spacer substrate 7 sandwich one ends of the input and output terminals 6, and the thickness of the input and output terminals 6 of both substrates 5 and 7 causes Since the other gap is filled with the resin sheet 8, it is possible to prevent cracks or cracks due to the pressing force from above the combined substrate 5, and to improve the substrate strength against external force. As a result, the reliability of quality can be improved, and the defective rate in mass production can be reduced. Since the gap due to the thickness of the input and output terminals 6 is about 0.15 mm, the resin sheet 8 does not significantly increase the product cost. In addition, the pressure resistance can be increased to about 2 Kgf by filling this gap.

In the above embodiment, the case where the input and output terminals are projected in the direction orthogonal to the dielectric resonator is taken as an example, but the present invention is designed so as to be projected in the axial direction of the dielectric resonator. It can also be applied to structures. In the above embodiment, the dielectric filter using the dielectric coaxial resonator is described as an example, but the present invention is not limited to this, and can be applied to, for example, an integrally molded dielectric filter. ..

[0017]

[Effect of the device]

 As described above, according to the dielectric filter of the present invention, since the gap between the coupling substrate and the spacer substrate is filled with the resin sheet, the substrate strength against external force can be improved, cracks at the time of assembly can be prevented, and reliability of quality can be improved. There is an effect that can improve the sex.

[Brief description of drawings]

FIG. 1 is a front view illustrating a dielectric filter according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a resin sheet of the above embodiment.

FIG. 3 is an exploded perspective view showing the dielectric filter of the above embodiment.

FIG. 4 is a front view showing a conventional dielectric filter.

FIG. 5 is an exploded perspective view showing a conventional bonded substrate.

[Explanation of symbols]

 1 Dielectric Filter 2a Grounding Case 3 Dielectric Coaxial Resonator 5 Coupling Board 6 Input / Output Terminals 7 Spacer Board 8 Resin Sheet

Claims (1)

[Scope of utility model registration request] 1. A coupling substrate to which a plurality of resonators are connected,
Placed on the case in a non-contact state via the spacer substrate,
In a dielectric filter in which an input terminal and an output terminal are sandwiched and connected to the combined substrate, the gap between the combined substrate and the spacer substrate is filled with a resin sheet. Body filter.