WO2006085465A1

WO2006085465A1 - Lc filter composite module

Info

Publication number: WO2006085465A1
Application number: PCT/JP2006/301729
Authority: WO
Inventors: Tsuyoshi Suesada; Toshihiro Hosokawa; Kazushige Sato; Toshifumi Oida
Original assignee: Murata Manufacturing Co., Ltd.
Priority date: 2005-02-10
Filing date: 2006-02-02
Publication date: 2006-08-17
Also published as: JPWO2006085465A1

Abstract

An LC filter composite module wherein first built-in capacitors (C5, C6) provided inside a multilayer board (20) are arranged directly under chip type inductors (L1, L2), and the first built-in capacitors (C5, C6) are positioned in a region at least partially overlapped with the chip type inductors (L1, L2) in plane view. The chip type inductors (L1, L2), the first built-in capacitors (C5, C6) and second built-in capacitors (C1-C4) are electrically connected to configure a highpass filter (35). Ground electrode patterns (G1, G2) are provided with a notched section or an opening section (K) at a section directly below the chip type inductors (L1, L2). The first built-in capacitors (C5, C6) and the chip type inductors (L1, L2) are electrically connected through a via hole conductor (VH).

Description

Specification

LC filter composite module technology

The present invention relates to an LC filter composite module, and more particularly to an LC filter composite module used for a mobile communication device or the like.

Background art

[0002] Conventionally, the LC filter composite module described in Patent Document 1 is known. As shown in FIG. 8, in this LC filter composite module 60, the coil electrode pattern of the inductor L and the capacitor electrode pattern of the capacitor C constituting the L C filter 62 are all provided in the multilayer substrate 61. Further, a ground electrode pattern G is also provided inside the multilayer substrate 61. On one main surface of the multilayer substrate 61, a surface mounting component 63 such as a chip resistor and a semiconductor device (IC) 64 are mounted.

Incidentally, the substrate built-in LC filter 62 of Patent Document 1 requires a high Q value in order to obtain high attenuation in the stop band near the pass band. However, when the coil electrode pattern and the ground electrode pattern G come close to each other, the Q value of the inductor L deteriorates by blocking the magnetic flux generated in the ground electrode pattern G force inductor L built in the multilayer substrate 61. The For this reason, the coil electrode pattern and the ground electrode pattern G cannot be brought close to each other, and there is a problem that the thickness of the multilayer substrate 61 cannot be reduced.

Therefore, the present inventors do not incorporate the LC filter in the multilayer substrate 71 like the LC filter composite module 70 shown in FIG. 9, but mount it on one main surface of the multilayer substrate 71 as the chip component 72. I thought about what I did. However, the LC filter configured as the chip component 72 has a built-in ground electrode pattern to suppress the coupling between the coil electrode pattern and the capacitor electrode pattern. The coil electrode pattern and the ground electrode pattern tend to be close to each other. Then, the reason factor similar to that described above is deteriorated, and the Q value of the LC filter is deteriorated, so that the coil electrode pattern and the ground electrode pattern cannot be brought close to each other. As a result, the thickness of the multilayer substrate 71 can be made thinner than the multilayer substrate 61 of FIG. However, there is a limit to downsizing the composite module 70 because a large LC chip component 72 must be installed.

Patent Document 1: JP 2000-165273 A

Disclosure of the invention

Problems to be solved by the invention

[0005] Therefore, an object of the present invention is to provide an LC filter composite module that can obtain high attenuation in the stop band near the pass band and can be sufficiently reduced in height.

Means for solving the problem

In order to achieve the above object, the LC filter composite module according to the present invention includes:

(a) a multilayer substrate formed by stacking a plurality of dielectric layers;

(b) a surface mount component including a chip type inductor mounted on one main surface of the multilayer substrate;

(c) When including a first built-in capacitor formed by a capacitor electrode provided inside the multilayer board and a chip-type inductor provided on one main surface of the multilayer board, and in plan view An LC filter in which the first built-in capacitor is arranged in a region at least partially overlapping the chip inductor;

(d) Arranged in the vicinity of one main surface of the multilayer substrate, and provided on substantially the entire surface of the dielectric layer with a notch or opening in the portion immediately below the chip-type inductor when viewed in plan. Grounded electrodes,

It is provided with.

Here, the surface mount component includes a semiconductor device and the like. It is preferable that the first built-in capacitor and the chip inductor are electrically connected via a via-hole conductor or the like provided in the dielectric layer. The via hole conductor may be provided in a notch or an opening formed in the ground electrode.

[0008] In addition, the LC filter preferably includes a series circuit of a first built-in capacitor and a chip inductor, and the first built-in capacitor is preferably disposed immediately below the chip inductor.

[0009] Further, the LC filter includes a second built-in capacitor constituted by a capacitor electrode provided inside the multilayer substrate, and the second built-in capacitor is a first built-in capacitor. It may be arranged at a position facing the chip type inductor with a gap therebetween.

[0010] The LC filter may be a noise-pass filter in which a series circuit of a first built-in capacitor and a chip inductor is electrically shunt-connected to a second built-in capacitor.

The invention's effect

[0011] According to the present invention, since the LC filter is composed of the first built-in capacitor provided inside the multilayer substrate and the chip inductor, the coil electrode in the chip inductor is connected to the multilayer substrate. The ground electrode force can also be released. On the other hand, the effective height of the LC filter is the sum of the thickness of the multilayer substrate and the height of the chip inductor. In other words, about half of the LC filter is equivalent to being embedded in a multilayer substrate. As a result, a low profile LC filter composite module can be obtained.

[0012] Since the first built-in capacitor is arranged in a region at least partially overlapping with the chip inductor when seen in a plan view, the distance between the first built-in capacitor and the chip inductor is reduced, and the parasitic inductance is reduced. The Q value of the LC filter can be increased. Furthermore, since the ground electrode has a notch or an opening immediately below the chip inductor, it is possible to prevent the Q value from deteriorating because the ground electrode may not block the magnetic flux generated in the chip inductor.

Brief Description of Drawings

FIG. 1 is a schematic front view showing an embodiment of an LC filter composite module according to the present invention.

FIG. 2 is a top view showing (a) the first sheet to (f) the sixth sheet constituting the multilayer substrate of the LC filter composite module of FIG.

FIG. 3 is a top view showing (a) the seventh sheet to (f) the twelfth sheet constituting the multilayer substrate of the LC filter composite module of FIG.

4 is a (a) 13th sheet to (e) top view showing a 17th sheet and (f) a bottom view showing the 17th sheet constituting the multilayer substrate of the LC filter composite module of FIG. 1.

FIG. 5 is a schematic diagram showing a vertical cross section of the LC filter composite module shown in FIG. 1.

FIG. 6 is an electrical equivalent circuit diagram of the LC filter composite module shown in FIG.

FIG. 7 is a graph showing the attenuation characteristics of the LC filter composite module shown in FIG. FIG. 8 is a schematic front view of a conventional LC filter composite module.

FIG. 9 is a schematic front view of another conventional LC filter composite module.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the LC filter composite module according to the present invention will be described with reference to the accompanying drawings.

[0015] As shown in FIG. 1, the LC filter composite module 1 is composed of chip-type inductors LI and L2, which constitute an LC filter on the upper surface of a multilayer substrate 20, surface mount components 3 such as chip resistors, and semiconductor devices ( IC) 4 is mounted.

FIGS. 2 to 4 are a top view of dielectric sheets 21a to 21q and a bottom view of dielectric sheet 21q constituting the multilayer substrate 20 of the LC filter composite module 1 of FIG. Dielectric sheets 21a to 21q are prepared by dispersing a ceramic powder mainly composed of barium oxide, aluminum oxide, and silica in a solvent to prepare a ceramic slurry, which is then formed into a sheet by a doctor blade method. obtain. Next, electrode patterns are formed on each of the dielectric sheets 21a to 21q by a screen printing method.

[0017] On the upper surface of the first dielectric sheet 21a, lands 22 and 23 for mounting the chip type inductors LI and L2 mounted on the upper surface of the multilayer substrate 20 and the surface mount component 3 are mounted. Land 24 and land 25 for mounting the semiconductor device 4 are formed. That is, as shown by a broken line in FIG. 2 (a), the chip type inductor L1 is connected to the land 22 via a bonding material such as solder, and the chip type inductor L2 is connected via a bonding material such as solder. Connected to Land 23.

Capacitor electrode patterns Cpl to Cp8 are formed on the top surfaces of the sixth, thirteenth, fourteenth and fifteenth dielectric sheets 21f, 21m, 21η, 21ο. Further, stripline electrode patterns SL are formed on the top surfaces of the eleventh and twelfth dielectric sheets 21k and 211, respectively.

[0019] Ground electrode patterns G1 to G5 are formed on the top surfaces of the third, fifth, seventh, tenth, and fifteenth dielectric sheets 21c, 21e, 21g, 21j, and 21o to cover substantially the entire surface of the dielectric sheets. Has been. The ground electrode patterns G1 to G5 are used to prevent electromagnetic interference between the surface mount component 4 such as a semiconductor device (IC chip) and circuit elements in the multilayer substrate 20, or to strip the multilayered substrate 20 into the This is necessary for forming a line structure. In particular, the ground electrode patterns Gl and G2 disposed in the vicinity of the upper surface of the multilayer substrate 20 have notches (or openings) K directly below the chip inductors LI and L2 when viewed in plan. Yes. The Q values of these chip-type inductors L1 and L2 that do not block the magnetic field generated around the chip-type inductors LI and L2 due to the notches K formed in the ground electrode patterns Gl and G2 in this way. Is not reduced.

[0020] An external terminal electrode 30 is formed on the bottom surface (Fig. 4 (f)) of the seventeenth dielectric sheet 21q. In addition, the first to seventeenth dielectric sheets 21a to 21q have lands 22 to 25, capacitor electrode patterns Cpl to Cp8, stripline electrode patterns SL1 and SL2, ground electrode patterns G1 to G5, and external parts at predetermined positions. A via hole conductor VH for connecting the terminal electrode 30 is provided.

Here, the capacitor electrode patterns Cp5, Cp6 constitute first built-in capacitors C5, C6, respectively, facing the ground electrode pattern G3 with the sixth dielectric sheet 21f interposed therebetween. The capacitor electrode patterns Cp2 and Cp3 constitute the second built-in capacitors C2 and C3, respectively, facing the capacitor electrode patterns Cp7 and Cp8 across the thirteenth dielectric sheet 21m. The capacitor electrode patterns Cpl and Cp4 constitute the second built-in capacitors CI and C4, respectively, facing the capacitor electrode patterns Cp7 and Cp8 with the 14th dielectric sheet 21η interposed therebetween.

In this embodiment, the capacitance C for constituting the LC filter includes a built-in capacitor C 5 formed between the capacitor electrode pattern Cp5 and the ground electrode pattern G3, and the capacitor electrode pattern Cp6 and the ground electrode. It is composed of a built-in capacitor C6 formed between the pattern G3. The inductance L for configuring the LC filter is composed of a chip inductor Ll and a chip inductor L2. The chip inductor L1 and the capacitor electrode pattern Cp5 are connected in series via the via-hole conductor VH1, and an LC series resonance circuit of the chip inductor L1 and the built-in capacitor C5 is formed. Similarly, the chip inductor L2 and the capacitor electrode pattern Cp6 are connected in series via the via-hole conductor VH2, and an LC series resonance circuit of the chip inductor L2 and the built-in capacitor C6 is formed. These bi The hole conductors VH1 and VH2 are notched portions formed in the ground electrode patterns Gl and G2 provided in the layer between the upper surface of the multilayer substrate 20 and the dielectric layer provided with the capacitor electrode patterns Cp5 and Cp6, respectively. It is provided at K.

[0023] The dielectric sheets 21a to 21q are sequentially laminated with an upper force, and then pressed to form a laminated body block. The laminate block is fired after being cut into a predetermined size. As a result, the multilayer substrate 20 is obtained. External electrodes 32 are formed on the end portions of the multilayer substrate 20 by applying and baking a conductive paste. The external electrode 32 is electrically connected to the lead parts such as the ground electrodes G2 to G5.

In the LC filter composite module 1 obtained in this way, as shown in FIG. 5, the first built-in capacitors C5 and C6 provided inside the multilayer substrate 20 are arranged immediately below the chip inductors LI and L2. In plan view, the capacitor electrode patterns Cp5 and Cp6 for forming the first built-in capacitors C5 and C6 are located in a region at least partially overlapping the region where the chip inductors LI and L2 are provided. The second built-in capacitors C1 to C4 are arranged at positions opposite to the chip inductors LI and L2 across the first built-in capacitors C5 and C6. In this embodiment, the second built-in capacitors C1 to C4 are placed close to the first built-in capacitors C5 and C6 to shorten the routing pattern. It is not always necessary to place them at positions facing the type inductors L 1 and L2.

The chip inductors LI and L2, the first built-in capacitors C5 and C6, and the second built-in capacitors C1 to C4 are electrically connected to form a hynos filter 35.

FIG. 6 is an electrical equivalent circuit diagram of the high pass filter 35. A series resonant circuit of first built-in capacitors C5 and C6 and chip inductors LI and L2 is electrically shunt-connected to the second built-in capacitors C1 to C4. This shunt-connected series resonant circuit determines the blocking pole frequency. By changing the inductance values of chip-type inductors LI and L2, the resonant frequency of the shunt-connected series resonant circuit can be changed, and the frequency of the stopband also changes.

In the LC filter composite module 1 having the above configuration, the high-pass filter 35 is mounted on the surfaces of the built-in capacitors C1 to C6 provided inside the multilayer substrate 20 and the multilayer substrate 20. The chip electrode inductors LI and L2 are separated from the ground electrode patterns Gl and G2 arranged in the vicinity of the upper surface of the multilayer substrate 20. it can. On the other hand, the effective height of the hynos filter 35 is the total dimension of the thickness of the multilayer substrate 20 and the heights of the chip inductors LI and L2. That is, about half of the high-pass filter 35 is equivalent to being embedded in the multilayer substrate 20. As a result, a low-profile LC filter composite module 1 is obtained.

[0028] When viewed in plan, the first built-in capacitors C5 and C6 are arranged in a region at least partially overlapping the chip inductors LI and L2, and are connected substantially only via via-hole conductors. As a result, the parasitic inductance where the distance between the first built-in capacitors C5 and C6 and the chip inductors LI and L2 is reduced can be reduced, and the Q value of the high-pass filter 35 can be increased.

[0029] Further, the ground electrode patterns Gl and G2 arranged between the first built-in capacitors C5 and C6 and the chip inductors LI and L2 are notched (or notched) directly below the chip inductors LI and L2. Since the opening portion (K) is provided, it is possible to prevent the Q value from deteriorating because the ground electrode patterns Gl and G2 are not likely to block the magnetic flux generated in the chip type inductors LI and L2.

[0030] Also, the first built-in capacitor C5 and the chip inductor L1 are electrically connected via via-hole conductors VH 1 provided in the first to fifth dielectric sheets 21a to 21e! . Similarly, the first built-in capacitor C6 and the chip inductor L2 are also electrically connected via via-hole conductors VH2 provided in the first to fifth dielectric sheets 21a to 21e. Since the via-hole conductor generally has a lower resistance value than the thick film conductor, the Q value of the high-pass filter 35 can be further increased.

[0031] As a result, the high-performance L is low in profile and has low unwanted radiation near the passband and low interference wave penetration.

C filter composite module 1 is obtained.

[0032] Figure 7 shows that the passband is 2.402 to 2.480 GHz, and the stopband near the passband is 2.11.

2. This graph shows the attenuation characteristics of the LC filter composite module 1 equipped with the high-pass filter 35 designed to be 17 GHz. Since the high-pass filter 35 has a high Q value, a steep stopband can be obtained, which makes it difficult to understand.

[0033] The LC filter composite module according to the present invention is not limited to the above-described embodiment. Various modifications can be made within the scope of the gist.

[0034] In particular, in the above embodiment, dielectric sheets are stacked to form a laminated body !, but the laminated body is formed by a method in which dielectric slurry and conductive paste are sequentially overcoated. May be. Further, the laminate may be a ceramic multilayer structure in which ceramic green sheets are laminated, or a resin multilayer structure in which a resin layer is laminated.

Industrial applicability

[0035] As described above, the present invention is useful for LC filter composite modules used in mobile communication devices and the like, and in particular, high attenuation is obtained in the stopband near the passband, and sufficient. It is excellent in that a low profile can be achieved.

Claims

The scope of the claims

[1] a multilayer substrate formed by stacking a plurality of dielectric layers;

Provided on one main surface of the multilayer substrate and a first built-in capacitor composed of a surface mount component including a chip-type inductor mounted on one main surface of the multilayer substrate, and a capacitor electrode provided inside the multilayer substrate An LC filter configured to include the chip-type inductor, and the first built-in capacitor disposed in a region at least partially overlapping the chip-type inductor when viewed in plan,

Arranged in the vicinity of one main surface of the multilayer substrate, and provided on substantially the entire surface of the dielectric layer with a notch or an opening in a portion immediately below the chip-type inductor when viewed in plan. Ground electrode,

LC filter composite module characterized by comprising

[2] The LC filter includes a series circuit of the first built-in capacitor and the chip inductor, and the first built-in capacitor is arranged immediately below the chip inductor. LC filter composite module according to item 1.

[3] The LC filter further includes a second built-in capacitor configured by a capacitor electrode provided inside the multilayer substrate, and the second built-in capacitor is interposed between the first built-in capacitor and the chip. 3. The LC filter composite module according to claim 2, wherein the LC filter composite module is disposed at a position facing the type inductor.

[4] The LC filter is a no-pass filter in which a series circuit of the first built-in capacitor and the chip inductor is electrically shunt-connected to the second built-in capacitor. The LC filter composite module according to claim 3.

[5] The first built-in capacitor and the chip inductor are electrically connected via a via-hole conductor provided in the dielectric layer.

The LC filter composite module described in V!

[6] The via hole conductor for electrically connecting the first built-in capacitor and the chip inductor is provided in the notch or the opening of the ground electrode. The LC filter composite module according to claim 5. 7. The LC filter composite module according to claim 6, wherein said surface mount component includes a semiconductor device.