JP2001118734A - Composite laminated filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite laminated filter wherein problems such as disconnection of an inductance element and conductor loss are excluded and filter characteristic can be improved. SOLUTION: A laminated filter is constituted by bonding a laminate 1 and a resin molded member 2. A ground conductor 7b is stuck on the resin molded member 2. In the resin molded member 2, rod-shaped protrusions 2b, 2c or penetrating holes are formed perpendicularly on a bonding surface to the laminate 1. Conducting material 7a wherein the opposite side end portion of the bonding surface to the laminate is connected with the ground conductor 7b is stuck on the surfaces of the rod-shaped protrusions 2b, 2c or the inner surfaces of the penetrating holes, and inductance elements L1, L2 are constituted. The laminate 1 forms capacitors Ci, Cr and Cm in the inside by using a laminated structure and has I/O terminal electrodes 4, 5 and a ground terminal electrode 6. The capacitors Cr and the inductance elements L1, L2 are connected in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer filter used in a high-frequency region, and more particularly, to a filter having a band-pass filter characteristic used for, for example, a portable telephone, which uses a laminate and a resin molded product. And a composite laminated filter.

[0002]

2. Description of the Related Art A conventional laminated filter is generally formed as a stripline resonator obtained by laminating and sintering a dielectric layer and a conductor layer by a sheet laminating method or a screen printing method. Then, in order to reduce the size of the multilayer filter, a capacitor is provided inside the multilayer body and connected in parallel with the inductance element, so that the resonance frequency is lowered and a target filter characteristic is obtained.

However, in a multilayer filter using such a resonator, current concentrates on the edge portion of the conductor layer and the Q value is deteriorated, so that good filter characteristics cannot be obtained. There was a problem.

For the purpose of solving such a problem, Japanese Patent Application Laid-Open No. 9-35936 proposes that an inductance element is formed by laminating conductors filled in through holes.

[0005]

However, in the above-mentioned publication, since the inductance element is formed by a laminated structure, the position of the conductor in each layer of the through-hole varies and the filling property of the conductor paste into the through-hole is poor. Accordingly, there is a problem that the conductor loss of the inductance element becomes large or a disconnection failure occurs, and a laminated filter having a high Q value and good characteristics cannot be obtained.

The present invention has been made in view of the above-mentioned problems of the prior art,
It is an object of the present invention to provide a composite multilayer filter that can improve the filter characteristics without the problem of disconnection of the inductance element and conductor loss.

[0007]

According to a first aspect of the present invention, there is provided a composite laminated filter in which a laminated body and a resin molded body are joined, a ground conductor is applied to the resin molded body, and the resin molded body is attached to the resin molded body. A rod-shaped projection or a through hole is formed perpendicularly to the joint surface with the laminate, and an end opposite to the joint surface with the laminate is connected to the ground conductor on a surface of the rod-like protrusion or an inner surface of the through hole. Forming an inductance element by applying a conductive material such that a capacitor is formed inside the laminated body and has an input / output terminal electrode and a ground terminal electrode,
The capacitor and the inductance element are connected in parallel.

The inductance element of the present invention is formed by applying a conductor by plating or the like to a rod-like projection or a through hole formed in a resin molded body, so that the conductor layer is formed to have a smooth and uniform thickness. Therefore, there is no possibility of disconnection, the conductor loss is small, and good filter characteristics with a high Q value can be obtained.

According to a second aspect of the present invention, there is provided a composite laminated filter according to the first aspect.
In the above, the resin molded body includes a plurality of the inductance elements, has a plurality of capacitors respectively connected in parallel to each of the inductance elements to form a plurality of resonators, and forms an adjacent one of the plurality of resonators by electromagnetic waves. Each of the capacitors is coupled to an input / output terminal electrode by at least one of inductive coupling and capacitive coupling.

As described above, by providing a plurality of inductance elements having small conductor loss, connecting a capacitor to each inductance element in parallel to form a plurality of filters, and coupling them to each other, a filter having a narrow pass band is provided. Can be provided.

[0011]

FIG. 1A is a sectional view showing an embodiment of a composite laminated filter according to the present invention, FIG. 1B is a perspective view showing the resin molded product upside down, and FIG. (A)
Is a cross-sectional view of the composite laminated filter, FIG. 2B is an equivalent circuit diagram thereof, and FIG. 3 is a laminated structure diagram thereof.

As shown in FIGS. 1A and 2A, in the composite laminated filter of the present invention, a laminated body 1 and a resin molded body 2 are joined by a fixing agent 3 such as solder or a conductive adhesive. Do it. As shown in FIG. 1 (B), the resin molded body 2 has a single-sided opening structure having a concave portion 2a on the joint surface side with the laminate 1, and the joint surface with the laminate 1 is provided in the concave portion 2a. And two rod-like projections 2b and 2c perpendicular to the projection. In the present embodiment, as shown in FIG.
The conductor 7 is attached to the entire surface of the substrate by plating or the like. Among the conductors 7, the conductor 7a formed on the bar-shaped projections 2b, 2c functions as inductance elements L1, L2 (see FIG. 2B), and the other portion 7b functions as a ground conductor.

As a material of the resin molded body 2, either a thermosetting resin or a thermoplastic resin is used. In order to withstand high temperatures during reflow when the resin molded body 2 is joined to the laminate 1 by soldering, the thermosetting resin is selected from epoxy, phenol, diallyl phthalate, cyanate ester and the like. Is preferred. Also,
Among the thermoplastic resins, it is preferable to select from aromatic polyester (liquid crystal polymer), polyphenylene sulfide, polyamide, polyetherimide, and polyetheretherketone. The molding of the resin molded body 2 is performed by a molding method such as injection molding.

The conductor 7 is formed by plating.
The plating is made thin (several μm
About) plating is performed, and then the conductor 7 is formed to a desired thickness by electrolytic plating. The material of the conductor 7 is C
u, Ni, Sn, Pd, solder plating, etc. are considered,
In general, Cu plating is used, and Ni + Au plating, Ni + Sn
Plating, Ni + solder plating or the like may be applied. If a predetermined peel strength is required, a surface treatment is performed before plating.
The surface treatment includes chemical etching using an acid or an alkali, and surface modification using plasma or UV irradiation.

On the other hand, as shown in FIG. 1A, the laminated body 1 is provided with terminal electrodes 4 and 5 used as input terminal electrodes or output terminal electrodes on both end surfaces, and ground terminal electrodes 6 on both side surfaces. ing.

Next, the laminated structure in the laminated body 1 will be described with reference to FIG.
(A) will be described with reference to FIG. This laminate is manufactured by a sheet laminating method or a screen printing method. In FIG. 3, reference numerals 1 a to 1 f denote a dielectric layer made of a ceramic dielectric sheet in the sheet laminating method or one layer printed by the screen printing method 2 shows a ceramic dielectric layer of the present invention. Reference numerals 8a and 8b denote capacitor electrodes whose lead portions 8c and 8d are connected to the input / output terminal electrodes 4 and 5, respectively. 9a to 9c are capacitor electrodes connected to each other by via holes 10a, 10b and 10c, 10d. 11a to 11c are via holes 12a, 12
b and capacitor electrodes connected to each other by 12c and 12d.

The capacitor electrodes 8a and 9a, 8b and 1
1a constitutes a capacitance component Ci for impedance matching for preventing reflection in FIG. 2B.

The capacitor electrodes 9a, 11a and 9b,
11b, a capacitor electrode 13 sandwiched between the dielectric layers 1c and 1d is formed.
The coupling capacitance component Cm between the resonators shown in FIG.

The capacitor electrodes 9b, 11b and 9c,
11c, a grounding capacitor electrode 14 sandwiched between the dielectric layers 1e and 1f is formed, and a resonance capacitor connected in parallel to the inductance elements L1 and L2 shown in FIG. It constitutes a loading capacity component Cr for vessel formation. On the uppermost dielectric layer 1f, a grounding capacitor electrode 15 is formed so as to surround the capacitor electrodes 9c and 11c.
Is formed.

The production of the multilayer filter is performed by forming the dielectric layers 1a to 1c in which each of the capacitor electrodes is formed by a plurality of the multilayer filters.
If is overlapped, press-bonded, cut, and fired, terminal electrodes 4, 5, and 6 are provided for each chip by baking or plating. The input / output terminal electrodes 4 and 5 are connected to the lead portions 8c and 8d of the capacitor electrodes 8a and 8b, respectively, and the ground terminal electrode 6 is connected to side surfaces of the grounding capacitor electrodes 14 and 15.

The lower surface of the resin molding 2, ie, the bonding surface, is placed on the upper surface of the laminate 1 thus manufactured, ie, the bonding surface, with the bonding agent 3 interposed therebetween, and the ground terminal electrode 6 is attached to the resin molding 2. In addition to being electrically connected to the ground conductor 7b, the capacitor electrodes 9c and 11c are electrically connected to the conductor 7a at the tip of the rod-shaped projections 2b and 2c, and are also mechanically joined. In this case, short-circuits between the input / output terminal electrodes 4 and 5 and the ground conductor 7b are prevented by providing concave portions 2d and 2e at both ends of the lower surface of the resin molded body 2 in advance.

As described above, the inductance elements L1, L
By forming the resin filter 2 from the resin molded body 2, there is no possibility of disconnection, and a multilayer filter having good characteristics and a small Q with a small conductor loss can be realized. Also,
As in the present embodiment, a plurality of inductance elements L
1 and L2 and loading capacitance components (capacitors) Cm, respectively forming resonators to form inductance elements L1 and L2.
By coupling (M coupling) by electromagnetic induction or coupling by capacitive coupling by the coupling capacitance component Cm, a filter having a narrow frequency band and steep characteristics can be realized. The number of resonators can be configured as three or more.

FIG. 4 is a cross-sectional view showing another embodiment of the present invention. In the present embodiment, through holes 2f, 2g perpendicular to the joint surface with the laminated body 1 are formed in the resin molded body 2. The conductor 7c is provided by plating or the like in the through-holes 2f and 2g, and the conductor 7 is not provided on the joint surface with the laminate 1, and the ground conductor 7b is provided on the other portion, so that the through-hole can be provided. The holes 2f and 2g are configured as inductance elements. In the structure in which the conductor 7 is not provided on the joint surface of the resin molded body 2, the mask is removed on the joint surface during plating, and the mask is removed after plating, or the joint surface is polished after plating the entire surface to remove the conductor 7. And the like.
Also in the structure of FIG. 4, it is possible to realize a multilayer filter having good characteristics having a high Q value with a small internal loss and a small conductor loss as the inductance element, which may be disconnected.

In the present invention, as the laminate 1, a resin laminate in which the dielectric layers 1a to 1f are not ceramic but the above-mentioned resin or a mixture of these and ceramic powder can be employed.

[0025]

According to the first aspect of the present invention, an inductance element is formed by applying a conductor to the rod-shaped protrusion or through-hole formed in the resin molded body by plating or the like, and the resin molded body is formed into a laminated body having a built-in capacitor. Since the conductor of the inductance element has a smooth and uniform thickness of the conductor layer, there is no risk of disconnection, and the conductor loss is small.
Good filter characteristics with a high Q value can be obtained.

According to the second aspect, in the first aspect, a plurality of inductance elements having small conductor loss are provided, and a plurality of filters are formed by connecting capacitors in parallel to each of the inductance elements, and are connected to each other. Can be provided.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view showing an embodiment of a composite laminated filter according to the present invention, and FIG. 1B is a perspective view showing a resin molded product thereof.

FIG. 2A is a cross-sectional view of the composite laminated filter of FIG. 1,
(B) is an equivalent circuit diagram thereof.

FIG. 3 is a diagram illustrating a multilayer structure of the multilayer filter of FIGS. 1 and 2;

FIG. 4 is a cross-sectional view showing another embodiment of the composite laminated filter according to the present invention.

[Explanation of symbols]

1: laminated body, 1a to 1f: dielectric layer, 2: resin molded body,
2b, 2c: rod-shaped projection, 2f, 2g: through hole, 3: adhesive, 4, 5: input / output terminal electrode, 6: ground terminal electrode, 7,
7a, 7c: conductor, 7b: ground conductor, 8a, 8b, 9a
To 9c, 11a to 11c, 13: capacitor electrode, 1
4, 15: grounding capacitor electrode

Claims (2)

[Claims] A laminated body and a resin molded body are joined together. A ground conductor is applied to the resin molded body, and a rod-shaped member is formed on the resin molded body so as to be perpendicular to a joint surface of the resin molded body with the laminate. A projection or a through-hole is formed, and a conductive material whose end opposite to the joint surface with the laminate is connected to the ground conductor is formed on the surface of the rod-shaped projection or the inner surface of the through-hole to form an inductance element. A composite multilayer filter, wherein the multilayer body has a capacitor formed therein in a multilayer structure, has an input / output terminal electrode and a ground terminal electrode, and has the capacitor and the inductance element connected in parallel. 2. The plurality of resonators according to claim 1, wherein the resin molded body includes a plurality of the inductance elements and a plurality of capacitors connected in parallel to each of the inductance elements to form a plurality of resonators. A composite multilayer filter, wherein adjacent resonators are coupled by at least one of electromagnetic induction coupling and capacitive coupling, and each capacitor is coupled to an input / output terminal electrode.