JPH11150402A - Stacked-type filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To match a frequency characteristic after trimming with a frequency characteristic after shorted circuits are cut by printing a ground pattern on a dielectric green sheet and constituting the ground pattern, the detouring electrode of an input terminal and the electrode of an output terminal do not overlap, namely, in non-overlapped state. SOLUTION: A dielectric green sheet in which a detouring electrode 123 of the input terminal IN and a detouring electrode 124 of the output terminal OUT are formed at the back is stacked on a printing sheet and a ground pattern 121 is printed on it. Recessed parts 131 and 132 are formed on the ground pattern 121. A part where the ground pattern 121 overlaps with the detouring electrodes 123 and 123 so constituted so as not to exist, and floating capacity is prevented from existing in the part. Thus, the dispersion of shift quantity due to the dispersion of the floating capacity of already adjusted filter characteristic can be eliminated at cutting of short circuits SC1 and SC1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a mobile phone,
The present invention relates to a multilayer filter used in a high-frequency circuit of a mobile communication device such as a cordless horn.

[0002]

2. Description of the Related Art In recent years, laminated filters have been widely used in mobile communication devices such as mobile phones. The laminated filter has a circuit as shown in FIG. 7, for example, and has a structure in which a plurality of resonance circuits Z1 and Z2 are formed on one base 1 constituting the filter. These resonance circuits Z1 and Z2 are electrically coupled to each other.

At first, as shown in FIG. 8, a resonance circuit Z1 is a variable impedance element Z12 which is a capacitor whose capacitance can be adjusted by trimming, as will be described later.
And a parallel circuit of an impedance element Z11 which is an inductance. One end of the resonance circuit Z1 is connected to the ground terminal T11, and the other end is connected to a first impedance element Z13 which is a capacitor and a short circuit SC.
It is connected to the input terminal IN via one parallel circuit.

Similarly, the resonance circuit Z2 is constituted by a parallel circuit of a variable impedance element Z22 which is a capacitor whose capacitance can be adjusted by trimming and an impedance element Z21 which is an inductance. One end of the resonance circuit Z2 is connected to the ground terminal T21, and the other end is connected to the output terminal O via a parallel circuit of the second impedance element Z23, which is a capacitor, and the short circuit SC2.
Connected to UT.

[0005] Then, as shown in FIG.
1, a characteristic measuring device 2 such as a network analyzer is connected to an input terminal IN, and a ground terminal T1 is connected to the input terminal IN.
Ground 1 At this time, on the resonance circuit Z2 side, the output terminal OUT and the ground terminal T12 are grounded.

[0006] The circuit constant of the variable impedance element Z12 included in the resonant circuit Z1 in this state, adjusted as described below, to adjust the characteristics of the resonance circuit Z _1. For example, the frequency-reflection characteristic S11 of the resonance circuit Z1 before adjustment is shown in FIG.
8B, when the resonance frequency fr1 is lower than the target frequency fo1, the circuit constant value of the variable impedance element Z12 is adjusted.
As shown in (C), the resonance frequency is adjusted to the target frequency fo1.

At this time, since the output terminal OUT of the resonance circuit Z2 is grounded and short-circuited with the ground terminal T21,
The resonance circuit Z1 during the characteristic adjustment operation is connected to the resonance circuit Z2 during the operation.
Is not affected.

After the characteristic adjustment of the resonance circuit Z1 is completed, the characteristic adjustment of the resonance circuit Z2 is performed in the same manner. This time, FIG.
As shown in the figure, the characteristic measuring device 2 is connected to the output terminal OUT of the resonance circuit Z2, and the ground terminal T21 is grounded. Then, on the resonance circuit Z1 side, the input terminal IN and the ground terminal T11 are grounded.

In this state, the circuit constant value of the variable impedance element Z22 of the resonance circuit Z2 is adjusted, and its characteristics are adjusted. After the characteristic adjustment of the resonance circuits Z1 and Z2 is completed in this way, as shown in FIG.
The input terminal IN is cut off as shown in B1, and the short circuit SC2 is cut off as shown in B2 and the output terminal OU is cut out.
Disconnect from T. Thereby, as shown in FIG. 7, an original circuit configuration in which the resonance circuits Z1 and Z2 are connected to the input terminal IN or the output terminal OUT via the first impedance elements Z13 and Z23 forming the filter circuit is obtained. .

It is clear that the characteristics of the filter as a whole after such characteristic adjustment are obtained by combining the characteristics of the adjusted resonance circuits Z1 and Z2. FIG. 11 shows an example of a frequency-insertion loss characteristic obtained by combining the characteristics of the adjusted resonance circuits Z1 and Z2.

FIGS. 12 and 13 show the outer shape of the multilayer filter and the adjusting method according to the method described in Japanese Patent Application Laid-Open No. 9-36607. FIG. 12A is an external view of the multilayer filter, showing a state before trimming for adjustment and a short circuit are cut off, and FIG. 12B is a cross-sectional view showing the inside thereof.

In FIG. 12, a substrate 10 has variable impedance elements Z12 and Z2, which are capacitors, inside thereof.
2, pattern conductors 18 and 19 forming impedance elements Z13 and Z23 as capacitors, and pattern conductors 16 forming impedance elements Z11 and Z21 as inductances.
17 is provided in the dielectric layer, and the input terminal I
N, an output terminal OUT, and a ground conductor 11 are formed. The upper portion of the main surface of the ground conductor 11 constitutes a trimming electrode portion 111. A ground conductor 11-0 is also formed on the lower surface.

The characteristic adjustment of the resonance circuit Z1 is performed as shown in FIG.
As shown in (A), a wiring 2 such as a cable is connected to the input terminal IN.
1, the characteristic measuring device 2 is connected, and the output terminal OUT is grounded by a wiring 22 such as a cable. In this state, the trimming electrode unit 111 is trimmed, that is, partially deleted by using a trimming device 23 such as a laser or a sandblast. Thereafter, the characteristics of the resonance circuit Z2 are similarly adjusted by trimming. The deletion units 112 and 113 in FIG. 13B show these trimmed states.

Only by this trimming, the first short-circuit SC1 and the second short-circuit SC required for the characteristic adjustment
2 does not function as it is because the impedance elements Z13 and Z23 are short-circuited. In order for these to function, it is necessary to disconnect the short circuits SC1 and SC2.

Therefore, as shown in FIG. 13 (C), the input terminal IN is cut in the direction of arrow X1 on the main surface of the trimming electrode section 111 by using the trimming device 23.
I do. Further, as shown in FIG. 13D, the output terminal OUT is cut B2 in the direction of the arrow X2. In this way, a multilayer filter having a circuit as shown in FIG. 7 is obtained.

When a laminated filter as shown in FIG. 12 is prepared, first, pattern conductors 16 and 17 for inductance, pattern conductors 18 and 19 for input / output capacitors, and impedance elements are printed on a printing sheet (base). A plurality of types of dielectric green sheets prepared according to patterns such as the pattern conductors 12 and 13 for Z12 and Z22, the pattern conductor 111 for the trimming electrode portion, and a blank (pattern) for adjusting the interval in the thickness direction of each pattern conductor. The laminated and stacked dielectric green sheets (with no conductor formed) are inverted, and the pattern conductor 11-0 for the ground conductor 11 is printed. Thereafter, individual chips (substrate 10) are formed through processes such as baking and cutting, and conductive paste for the input / output terminals IN and OUT and the ground terminal 11 is adhered using a transfer technique, and is baked.

Although not shown in FIG.
0, a via hole is formed, and pattern conductors 16 and 17 for inductance and impedance element Z12,
The first short circuit SC1 and the second short circuit SC2 are formed by connecting the pattern conductors 12 and 13 for Z22. The ground conductors 11 and 11-
0 is formed.

[0018]

There is no problem if the ground conductor 11-0 can be first printed on a printing sheet (base), but the ground conductor 11-0 can be laminated like a dielectric green sheet. However, since it is printed with a conductive paste, as described above, a step for printing the ground conductor 11-0 on the outside when forming the base 10 is required.

In order to improve this and print the ground conductor 11-0 on the dielectric green sheet in the same manner as other conductive patterns for inductance and capacitors without printing the ground conductor 11-0 on the outside later, FIG. As shown in FIG. 7, a dielectric green sheet 120 is laminated on a printing sheet (base) (not shown), and a ground pattern 121 corresponding to the ground conductor 11-0 is printed thereon with a conductive paste.

Then, in the same manner as described above, after laminating a certain number of dielectric green sheets, the pattern conductors L1 and L2 of the inductance part of the resonator are printed, and the pattern conductors Cio1 and Cio2 of the input / output capacitor are printed. The pattern conductors Ct1 and Ct2 of the capacitor portion of the container are printed, and the ground pattern 122 on the surface serving as the trimming electrode portion, the wraparound electrode 125 of the input terminal IN, and the wraparound electrode 126 of the output terminal OUT are printed.

At this time, a via hole VH for connecting the pattern conductors L1 and L2 of the inductance portion and the pattern conductors Ct1 and Ct2 of the capacitor portion of the resonator is formed, and both are connected to form a short circuit SC1 and SC2.
SC2 is formed and the wraparound electrodes 125 and 126 are formed.
And the pattern conductors Ct1 and Ct in the capacitor portion of the resonator.
t2 is connected.

A wraparound electrode 123 for the input terminal IN, which is a side electrode, and a wraparound electrode 124 for the output terminal OUT, which is also a side electrode, are formed on the back side of the base. These wraparound electrodes 123 and 124 are not specially printed, but when the input terminal IN and the output terminal OUT are transferred and printed on the side surface of the laminated filter with a rubber stamp, a part of the conductive paste existing in the groove of the rubber stamp becomes a rubber stamp. When these are pressed, they wrap around (fall downward) to the surface of the base, and these wraparound electrodes 123 and 124 are formed.

In the same manner as described above, the laminated filter having the above-described structure is connected to an input terminal S1 shown in FIG.
1 and the output terminal S22 is grounded, the frequency-reflection characteristic of the resonance circuit is measured, and as shown in FIG. At this time, a part of the ground pattern 122 is trimmed by a trimming device, and the capacitance of the capacitor Ct1 of the resonator is adjusted so that the resonance frequency becomes the target frequency Ft. Similarly, on the output terminal side, the output terminal S22 is connected to a characteristic measuring device, the input terminal S11 is grounded, and the ground pattern 12 is connected.
2 is trimmed to adjust the capacitance of the resonator capacitor Ct2. Note that the capacitors Cf and Cf respectively connected to the input terminal S11 and the output terminal S22 shown in FIG. 16A are stray capacitances.

The stray capacitances Cf, Cf exist between the wraparound electrode 123 of the input terminal IN and the ground pattern 121 and the wraparound electrode 124 of the output terminal OUT and the ground pattern 121 shown in FIG.

At the time of adjustment, the stray capacitances Cf and Cf are changed from the short-circuits SC1 and SC2 to the capacitors Ct of the respective resonance circuits.
1 and Ct2 are equivalent to being connected in parallel. Ct1 including the effect of each stray capacitance Cf,
Ct2 is trimmed to adjust the resonance frequency (A characteristic in FIG. 17 (B)).
By separating SC2, the stray capacitance Cf is separated from each resonance circuit, which has the effect of shifting the characteristics of the entire filter. Therefore, an object of the present invention is to provide a laminated filter having a ground pattern printed on a dielectric green sheet, in which a frequency characteristic after trimming and a frequency characteristic after cutting a short circuit are cut. Is to provide something that substantially matches.

[0026]

In order to achieve the above object, in the multilayer filter of the present invention, as shown in FIGS. 1A and 1B, a ground pattern 121, a wraparound electrode 123 of an input terminal IN, and an output terminal. OUT wraparound electrode 1
24 are configured so as not to overlap, that is, in a non-overlapping state. For example, concave portions 131 and 132 are formed in the ground pattern 121 so that the wraparound electrodes 123 and 124 and the ground pattern 121 do not overlap. As a result, no stray capacitance exists between the input terminal IN and the sneak electrode 123, and no stray capacitance exists between the output terminal OUT and the sneak electrode 124. Thus, it is possible to provide a laminated filter that solves the above-mentioned problem caused by the variation of the above.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1A is an exploded configuration view of a laminated filter according to an embodiment of the present invention, and FIG. 1B is a view showing the overlapping relationship between a wraparound electrode 123 of an input terminal IN and a ground pattern 121 and an output terminal as viewed from the back side. This shows the overlapping relationship between the OUT wraparound electrode 124 and the ground pattern 121. FIG. 2 is an upper and lower perspective view of the multilayer filter shown exploded in FIG. FIG. 3 is a circuit diagram of the laminated filter of the present invention after the short circuit has been cut.

As shown in FIG. 1A, the multilayer filter of the present invention has a wraparound electrode 12 of the input terminal IN on the back surface thereof.
3 and the dielectric green sheet 120 on which the wraparound electrode 124 of the output terminal OUT is formed is printed on a printing sheet (base).
(Not shown) stacked on top, and a ground pattern 1
21 is printed with a conductive paste. The ground pattern 121 has recesses 131 and 132 formed therein.
The wraparound electrode 123 is located in the recess 131, and the wraparound electrode 124 is located in the recess 132, so that there is no portion where the ground pattern 121 and the wraparound electrodes 122 and 123 overlap each other. I have.

On the ground pattern 121, as described above, the pattern electrodes L1,
L2 are laminated via a dielectric green sheet, and the pattern conductors Cio1, C for input / output capacitors are further laminated thereon.
io2 is laminated via a dielectric green sheet. A pattern electrode Ct for a capacitor of the resonator is formed thereon.
1, Ct2 is laminated via a dielectric green sheet,
On the main surface, the upper wraparound electrode 125 for the input terminal IN and the upper wraparound electrode 1 for the output terminal OUT are provided on the main surface.
26 and the ground pattern 122 are laminated via a dielectric green sheet.

The pattern electrodes L1 and L2 for inductance of the resonator are connected to the pattern electrodes Ct1 and Ct2 for capacitors by via holes VH and VH, respectively. The pattern electrodes Ct1 and Ct2 are connected to the short circuit SC1 and SC2, respectively.
SC2 is connected to the upper wraparound electrodes 125 and 126.

FIG. 2A is a perspective view of the laminated filter as viewed from above, and FIG. 2B is a perspective view of the laminated filter as viewed from below. 1 and 2, an input terminal IN and an output terminal OUT are formed by transfer on the left and right side surfaces of the multilayer filter, and the input terminal IN is connected to the upper wraparound electrode 125 and the lower wraparound electrode 123 is formed by sagging. I do.
Similarly, the output terminal OUT is connected to the upper wraparound electrode 126 to form the lower wraparound electrode 124 by sagging.
The ground conductor 11 connects the ground pattern 122 on the main surface and the ground pattern 121 on the bottom side.
Are formed on the other side surfaces of the laminated filter. This ground conductor 11 is connected to the pattern electrode L for inductance.
1, and also connected to one end of L2.

Thus, the input / output capacitor C
A laminated filter in which io1 and Cio2 are short-circuited to short-circuits SC1 and SC2 is obtained. After that, similarly to the above, first, a characteristic measuring device is connected to the input terminal IN side, the output terminal OUT is grounded, the ground pattern 122 on the main surface is trimmed by the trimming device, and the resonance frequency fr1 of the resonator Z1 is targeted. Adjust to the value. Next, input terminal I
N is grounded, the characteristic measuring device is connected to the output terminal OUT, and the ground pattern 1 on the main surface is trimmed by the trimming device.
22 is trimmed to adjust the resonance frequency fr2 of the resonator Z2 to a target value. Then, the short circuits SC1 and SC2 are cut by the trimming device.

Thus, the electric circuit of the multilayer filter is as shown in FIG. At this time, FIGS.
As shown in FIG.
31 and 132 are formed and do not overlap with the wraparound electrode 123 of the input terminal IN and the wraparound electrode 124 of the output terminal OUT, so that no stray capacitance exists between them.
Therefore, the electric circuit shown in FIG.

Therefore, as shown in FIG. 14 to FIG. 17, it is possible to effectively improve the conventional structure in which the stray capacitance has an adverse effect on the resonator. The method of non-overlapping is not limited to the formation of the concave portion. For example, as shown in FIG.
1 linear side lines P1 and P2
Patterning can also be performed so as not to overlap with 3, 124.

FIGS. 5 and 6 show a second embodiment of the present invention.
This will be described below. Although the input terminal IN and the output terminal OUT shown in FIGS. 1 and 2 are formed on different side surfaces of the multilayer filter, in the second embodiment, as shown in FIG. Input terminal IN and output terminal O
The UT is formed on the same side.

In the laminated filter of the second embodiment, as shown in FIG. 6, a dielectric green sheet 120 is laminated on a printing sheet (base) (not shown), and a ground pattern 121 is formed thereon. Print with conductive paste.
Side lines 121-1, 121 of this ground pattern 121
-2 is formed at a position that does not overlap with the wraparound electrodes 123 and 124.

On the ground pattern 121, as described above, the pattern electrodes L1, L for inductance of the resonator are provided.
2 are laminated via a dielectric green sheet, and further thereon are patterned conductors Cio1 and Ci for input / output capacitors.
o2 is laminated via a dielectric green sheet. A pattern electrode Ct for a capacitor of the resonator is formed thereon.
1, Ct2 is laminated via a dielectric green sheet,
The upper wraparound electrode 125 for the input terminal IN and the upper wraparound electrode 12 for the output terminal OUT are formed on the main surface on the upper side.
6 and the ground pattern 122 are laminated via a dielectric green sheet. In FIG. 6, the input terminal IN and the output terminal OUT are not shown.

The pattern electrodes L1 and L2 for inductance of the resonator are connected to the pattern electrodes Ct1 and Ct2 for capacitors by via holes VH and VH, respectively.
The pattern electrodes Ct1 and Ct2 are connected to the short circuit SC.
1. The upper wraparound electrodes 125, 12 by SC2
6 is connected.

After forming the laminated shape in this way,
As shown in FIG. 5, for example, an input terminal IN, an output terminal OUT, and a ground conductor
Transfer 1 At this time, the wraparound electrode 123 of the input terminal IN, the wraparound electrode 124 of the output terminal OUT, and the wraparound portion 11-1 of the ground conductor 11 are formed by dripping of the conductive paste at the time of this transfer. This FIG.
These input terminals IN, output terminals OUT,
It is preferable that a ground conductor is printed on the opposite side surface on which the ground conductor 11 is transferred and printed.

In the configuration of FIGS. 5 and 6, even if the input terminal IN, the output terminal OUT, and the ground conductor 11 are printed on the opposite side where the ground conductor is printed, the input terminal IN shown in FIG. Since there is no need to print anything on the two surfaces on which the output terminals on the opposite side are transferred and printed, there is an advantage that the number of printing steps may be reduced.

[0041]

According to the present invention, the following effects can be obtained. (1) Since the lower surface side wraparound portion of the input terminal and the ground electrode built in on the lower surface side of the base and the lower side wraparound portion of the output terminal do not overlap with the ground electrode built in the lower surface side of the base, neither No stray capacitance exists in the part. Therefore, it is an object of the present invention to improve the disadvantage that the shift amount of the adjusted filter characteristic varies when the first and second short circuits are cut off due to the variation of the stray capacitance on the input side and the output side which has conventionally existed in this portion. Can be.

(2) By a simple method of forming a concave portion on the lower surface side of the input terminal and the lower surface side of the output terminal of the ground electrode built in the lower surface side, the disadvantage due to the variation of the stray capacitance can be reduced. It can be improved effectively.

(3) A simple method in which a side line portion of a ground electrode built in the lower surface side is formed inside each position of the lower surface side wraparound portion of the input terminal and the lower surface side wraparound portion of the output terminal. Thereby, the defect caused by the variation of the stray capacitance can be effectively improved.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory diagram of an embodiment of the present invention.

FIG. 2 is a perspective view of an embodiment of the laminated filter of the present invention.

FIG. 3 is an electric circuit diagram of the multilayer filter of the present invention.

FIG. 4 is an explanatory view of a second embodiment of the laminated filter of the present invention.

FIG. 5 is a perspective view of a third embodiment of the present invention.

FIG. 6 is a configuration explanatory diagram of a third embodiment of the present invention.

FIG. 7 is an electric circuit diagram of the multilayer filter.

FIG. 8 is an explanatory diagram (part 1) of characteristic adjustment of the multilayer filter.

FIG. 9 is an explanatory diagram (part 2) of adjusting characteristics of the multilayer filter.

FIG. 10 is an explanatory view of a short circuit cut state.

FIG. 11 shows filter characteristics of the multilayer filter after characteristic adjustment.

FIG. 12 is an explanatory diagram of a configuration of a conventional laminated filter.

FIG. 13 is an explanatory diagram of a trimming state of a conventional laminated filter.

FIG. 14 is an explanatory diagram (part 1) of a configuration of a conventional laminated filter.

FIG. 15 is a diagram (part 2) illustrating the configuration of a conventional laminated filter.

FIG. 16 is an explanatory diagram of an electric circuit and characteristic adjustment of a conventional laminated filter.

FIG. 17 is a diagram illustrating a problem of a conventional laminated filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Base 11 Ground conductor 121,122 Ground pattern

Claims (3)

[Claims] A base, an input terminal, an output terminal,
A multilayer filter in which a ground conductor, a plurality of resonance circuits, a first impedance element, a second impedance element, a first short circuit, and a second short circuit are formed; A polyhedron having six major surfaces,
The input terminal and the output terminal are formed on at least one of both side surfaces of the base, have a trimming electrode portion on one of the main surfaces, and the first short circuit is provided on the base and one end is provided. Is connected to one of the resonance circuits, and the other end is led out to the outer surface of the base and connected to the input terminal, thereby short-circuiting the first impedance element. One end is provided on the base, one end is connected to the other one of the resonance circuits, and the other end is led out to the outer surface of the base and connected to the output terminal, thereby short-circuiting the second impedance element; The trimming electrode portion constitutes a part of the resonance circuit, and in the multilayer filter which is provided on the base so as to be capable of being trimmed, in the lower surface side wrap around the input terminal and the lower surface side around the output terminal. Laminated filters, characterized by comprising a viewing portion and a ground electrode which is built on the lower surface side non-overlapping state. 2. The multilayer filter according to claim 1, wherein a concave portion is formed in the ground electrode as the non-overlapping state. 3. The non-overlapping state wherein the side line portion of the ground electrode is located inside the positions of the lower surface side wraparound portion and the output side wraparound portion of the input terminal. Item 2. The laminated filter according to Item 1.