JP3126244B2 - High frequency LC composite parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency LC composite component (for example, a high frequency LC filter) in which a coil L and a capacitor C are mounted on a multilayer substrate.

[0002]

BACKGROUND OF THE INVENTION FIG. 5 is an explanatory view of a prior art, FIG. 5
A conventional example 1 (sectional view), Fig. 5 B is a conventional example 2 (sectional view)
FIG.

In FIG. 5 , 1 is a multilayer substrate, 1-1 to 1-8 are first to eighth layers (dielectric layers) of the multilayer substrate, 2 is a coil pattern, 3 is a capacitor electrode pattern, and 5 is a via. (Vi
a) and 6 indicate side electrodes (external terminals).

Conventionally, as a high-frequency LC filter using a coil L and a capacitor, an SMD type component (surface mounted component) using a multilayer substrate has been developed. Among them, S
Examples of the high-frequency LC filters MD modularized (Conventional Example 1, Conventional Example 2) are shown in Figure 5. Hereinafter, Conventional Example 1 and Conventional Example 2 will be described.

[0005]: conventional description of Example 1, ... Figure 5 A reference this SMD modular high frequency LC filter (SM
The D module) has a coil portion (L portion) formed by a conductor pattern and a capacitor portion (C portion) built in the multilayer substrate 1, and a side electrode 6 is formed outside the multilayer substrate 1. Specifically, it is as follows.

[0006] In FIG 5 A, the first layer of the multilayer substrate 1 1-
1 is used as a protective layer, and the second layer 1-2 to the fifth layer 1-
A coil pattern (conductor pattern) 2 is formed on each of the coils 5 and these coil patterns 2 are connected by vias 5 to form a coil section (L section).

A capacitor electrode pattern 3 is formed on the sixth layer 1-6 to the eighth layer 1-8 of the multilayer substrate 1.
Then, a capacitor is formed by these capacitor electrode patterns 3 to form a capacitor portion (C portion).

The coil section (L section) and the capacitor section (C
) Is a high-frequency LC filter (high-frequency LC composite component) that is formed as an SMD module by connecting predetermined patterns by vias 5 and connecting predetermined conductor pattern portions of a coil portion and a capacitor portion to side electrodes 6. And

In this case, a plurality of coils are set in the coil section, and a plurality of capacitors are set in the capacitor section. This component (high-frequency LC filter) has a structure in which a capacitor portion is arranged on the lower side (on the mounting surface side on the motherboard), and a coil portion is arranged on the upper side (L and C are arranged vertically).

In each of the above-mentioned layers, only the sixth layer 1-6 and the seventh layer 1-7 of the capacitor portion are thinned, and the other layers are all set to the same thickness. : In the conventional example 2 described ... view 5 B see Figure 5 B, the first layer of the multilayer substrate (top layer) 1-1
Is used as a protective layer and does not pattern a conductor or the like.

The second layer 1-2, the third layer 1-3, and the fourth layer 1-
A coil pattern 2 is formed on each of the coils 4 and these coil patterns are connected by vias to form a coil portion. In this case, the coil unit is composed of two coils.

The capacitor electrode pattern 3 is formed on the fifth layer 1-5, and the capacitor electrode pattern 3 is formed on the sixth layer 1-6. Then, a capacitor is formed between the capacitor electrode pattern 3 formed on the fifth layer 1-5 and the capacitor electrode pattern 3 formed on the sixth layer 1-6.

As described above, side electrodes are formed on the side surfaces of the multilayer substrate in which the layers forming the coil portion and the capacitor portion are laminated, and a high-frequency LC filter is formed as an SMD module.

In this example, in each of the above layers, only the fifth layer 1-5 of the capacitor section is thinned, and all the other layers are set to the same thickness. For example, in FIG. 5 B, the first layer 1-1 fourth layer 1-4, and the sixth layer 1-6 having a thickness of (is set all the same thickness) as the TO, constituting the capacitor portion When the thickness of the fifth layer 1-5 is TC, the thicknesses TO and TC are, for example, TO = 160 μm.
m, TC = 40 μm.

[0015]

The above-mentioned conventional apparatus has the following problems. For example, 50
When designing a high-frequency LC filters MH _Z ~300MH _Z bands, the value of the coil becomes about several 10NH～200nH, a frequency band in which a ferrite material is difficult to use. In a frequency band in which such a ferrite material is difficult, an air-core coil is used.

By the way, in order to realize about 100 nH with an air core coil, it is necessary to wind several turns. However, in order to reduce the size of the module, it was necessary to further increase the number of windings and create a target inductance.

As a result, the number of layers increases and the module becomes thicker. If the module is made of ceramics,
Due to the thickness of the module, debinding treatment and firing control were very difficult.

The present invention solves such a conventional problem and reduces the thickness of an LC composite component made into an SMD module.
An object is to realize a high Q of the coil.

[0019]

FIG. 1 is an explanatory view of the principle of the present invention. In FIG. 1, the same components as those in FIG. 7 are denoted by the same reference numerals.

The present invention is configured as follows to achieve the above object. : A plurality of dielectric sheets (first layer 1-1 to seventh layer 1-
7). A conductor pattern (coil pattern 2) constituting a coil (L) is provided on a part of the dielectric sheets (second layer 1-2 to fourth layer 1-4) of the multilayer substrate. )
And the other dielectric sheet (the sixth layer 1-
6, the seventh layer 1-7) is provided with a capacitor portion in which a conductor pattern (capacitor electrode pattern 3) constituting the capacitor (C) is set, and the coil portion and the capacitor portion face each other in the stacking direction of the multilayer substrate. In the high-frequency LC composite component arranged at the position, the dielectric sheet (the second layer 1-2 ) positioned between the uppermost conductor pattern and the lowermost conductor pattern set in the coil portion in the stacking direction of the multilayer substrate. , The thickness (TL) of the third layer 1-3) is set to be smaller (TL <TO) than the thickness (TO) of the other dielectric sheets (the first layer 1-1 etc.) excluding the capacitor section. ,And,
Between the coil section and the capacitor section,
Spacer layer (1-
5) was set.

[0021]

[0022]

The operation of the present invention based on the above configuration will be described with reference to FIG. : As described above, the thickness TL of the layer constituting the coil portion
If TL <TO, the number of coil turns per unit length (in this case, layer thickness) increases (compared to the case where TL = TO), as in the case of the solenoid coil. Goes up.

Further, since the conductor length (coil pattern length) does not change, the conductor loss does not change. Therefore, the coil has a high Q. As a result, when a filter is formed with the configuration, insertion loss and the like are improved.

Therefore, a high-inductance air-core coil can be set in a small module. In addition, the entire module can be reduced in thickness as the coil layer becomes thinner. For this reason, when the module is made of ceramics, the binder removal and the firing process at the time of manufacturing are facilitated.

When a spacer layer is set between the coil portion and the capacitor portion, the distance between the coil conductor and the conductor forming the capacitor electrode increases. This makes it possible to reduce the stray capacitance between the two conductors (compared to the case where no spacer layer is provided).

Therefore, unlike the conventional case, the impedance of the coil hardly decreases, and the actual resistance of the coil pattern does not need to be increased. As a result, the Q of the coil does not need to be reduced.

As described above, with the high-frequency LC composite component of the present invention, it is possible to realize a high Q coil in a small and thin SMD module.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. §1: Description of Embodiment FIGS. 2 to 4 are explanatory diagrams of an embodiment of the present invention .
Is an exploded perspective view of the high-frequency LC filter, FIG. 3A is a perspective view of the high-frequency LC filter, FIG. 3B is a cross-sectional view taken along the line XY of FIG. 3A, FIG.
FIG. 3 is a diagram showing passband characteristics of a high-frequency LC filter.

2 to 4, the same elements as those in FIGS. 1 and 5 are denoted by the same reference numerals. 6-1 is a terminal (OU)
T), 6-2 are terminals (IN), and 7 is a relay pad. This embodiment is an example of a high-frequency LC filter formed as a small SMD module by mounting a coil section (L section) and a capacitor section (C section) on a multilayer substrate, and will be described in detail below.

Description of Configuration of High-Frequency LC Filter As shown in FIG. 2, the multilayer substrate has first to seventh layers 1-1 to seventh.
It is composed of a dielectric sheet (dielectric layer) of layer 1-7. Each invitation
The conductor pattern formed on the electric sheet (dielectric layer) is as follows.

The first layer (uppermost layer) 1-1 of the multilayer substrate is used as a protective layer and does not pattern conductors or the like. Second layer 1-2, third layer 1-3, fourth layer 1-4
A coil pattern (conductor pattern) 2 is formed on the upper side by printing a conductor or the like, and these coil patterns are connected to each other by a via (a dotted line portion in FIG. 2) to form a coil portion. In this case, the coil unit includes two coils L1,
L2.

The fifth layer 1-5 is a spacer layer (dummy layer)
In this layer, only the relay pad 7 is formed by a conductor, and other conductor patterns and the like are not formed.

The sixth layer 1-6 is formed by printing a conductor or the like.
Forming a capacitor electrode pattern (conductor pattern) 3;
On the seventh layer 1-7, a capacitor electrode pattern (conductor pattern) 3 is formed.

Then, the capacitor C1 is formed between the capacitor electrode pattern 3 formed on the sixth layer 1-6 and the capacitor electrode pattern 3 formed on the seventh layer 1-7. Further, the end of the coil pattern 2 formed on the fourth layer 1-4 and the capacitor electrode pattern 3 formed on the sixth layer 1-6 are connected to each other via the relay pad 7 via (see dotted line in FIG. 2). Part) to connect the coil part and the capacitor part.

As described above, the multilayer substrate 1 in which the layers forming the coil portion and the capacitor portion are laminated (see FIG. 3A)
Side electrode (external terminal) 6-1 (OUT),
6-2 (IN) is formed, and a high frequency LC filter is formed as an SMD module.

FIG. 3C shows an equivalent circuit of the high-frequency LC filter having the small size and the SMD structure having the above-described configuration. This component (high-frequency LC filter) has a structure in which a capacitor portion is disposed on the lower side (on the mounting surface side on the motherboard) (located at a position facing each other in the stacking direction of the multilayer substrate), and a coil portion is disposed on the upper side thereof ( (L and C are arranged vertically).

: Explanation of the thickness of the layers of each part -1: Explanation of the thickness of the coil parts Each layer of the multi-layer substrate is configured as described above, but the first layer 1-1 to the seventh layer 1-7 Of these, the thicknesses of the second layer 1-2 and the third layer 1-3 constituting the coil portion are different from those of the other layers (the first layer 1-6) except the sixth layer 1-6 constituting the capacitor portion.
1, the fourth layer 1-4, the fifth layer 1-5, and the seventh layer 1-7).

For example, the second layer 1-2 and the third layer 1-3
(These layers have the same thickness.) The thickness of the first layer 1-1, the fourth layer 1-4, the fifth layer 1-5, and the seventh layer 1-
The thickness of 7 (these layers have the same thickness) is defined as TO,
Assuming that the thickness of the sixth layer 1-6 is TC, there is a relationship of TL <TO between TL and TO.

Although the thickness TC of the sixth layer 1-6 of the capacitor portion is usually set smaller than the thickness TO, the relationship with the thickness TL is arbitrary. The above thickness T
O, TL, and TC are, for example, TO = 160 μm and TL =
80 μm, TC = 40 μm.

The thickness TL of the coil portion varies depending on the inductance value of the coil to be set.
Is set to about 25 to 75%. When the inductance value of the coil is large, it is particularly effective to set the TL to be thin.

-2: Explanation of the thickness of the spacer layer The thickness of the fifth layer 1-5 as the spacer layer is set to TO (TO = 160 μm) as described above, but may be thicker than TO. In this case, for example, in order to obtain a required thickness, a plurality of dielectric sheets can be laminated to form a spacer layer.

However, if the thickness of the fifth layer 1-5 serving as the spacer layer is too large, it is difficult to control the binder removal and firing when the module is made of ceramics. Therefore, it is necessary to determine the shape after considering the shape of the entire filter. As a guide, for example, the total thickness should be set to 2 mm or less.

: Description of each part based on the above configuration -1: Description of the relation of TL <TO As described above, the thickness TL of the layer (dielectric layer or insulator layer) constituting the coil part is calculated as follows. If TL <TO, then
As in the case of the solenoid, the number of turns of the coil per unit length (in this case, the thickness of the layer) is increased (compared to the case where TL = TO), so that the inductance value of the coil is increased.

On the other hand, since the conductor length of the coil (coil pattern length) does not change, the conductor loss does not change. Therefore, the coil has a high Q. As a result, when a filter is made, the insertion loss is improved.

Therefore, a high inductance (100 nH)
) Can be set in a small module. Also, as the coil layer became thinner,
The whole module can be made thin. For this reason, when the module is configured as a ceramic, the binder is removed during manufacturing, and
The firing process is facilitated.

-2: Explanation of setting spacer layer As described above, since the spacer layer 1-5 is set between the coil section and the capacitor section, the distance (distance) between the coil section and the capacitor section is set. Can be increased.

That is, the coil pattern 2 formed on the fourth layer 1-4 and the capacitor electrode pattern 3 formed on the sixth layer 1-6 are separated by the thickness of the spacer layer 1-5. Become.

Therefore, the stray capacitance between the coil pattern 2 and the capacitor electrode pattern 3 is reduced as compared with the conventional example. As a result, the coil has a higher Q,
It is also effective in terms of insertion loss and the like.

Explanation of the characteristics of the high-frequency LC filter
FIG. 4 shows the characteristics (passband characteristics) of the high-frequency LC filter of the above embodiment. This pass band characteristic is a characteristic example based on measured data. For comparison, the characteristics of Conventional Example 2 are also shown.

In FIG. 4, the horizontal axis represents the frequency (fM
_Hz ), and the vertical axis indicates the attenuation (dB). Further, characteristics of the indicated by the dotted line in the figure, the a pass band characteristic of the conventional example 2 (see FIG. 5 B), the characteristics of the shown by the solid line, the above-described
It is a passband characteristic of an example (refer FIG. 2, FIG. 3).

The characteristics of the high-frequency filter is that it has become a passband characteristic having a pass band (frequency f _p) and an attenuation band (the frequency f _r). Note that when measuring characteristics of FIG. 4, for matching the frequency of the pass band and the frequency (f _r) of the attenuation band (f _p), patterning of the coils L1, L2, in embodiments, as compared with the conventional example 2 It was set slightly smaller in shape.

For this reason, in the embodiment, the coils L1,
Since the conductor resistance of L2 is low, the Q of the coil is high. Therefore, the characteristics are as shown in the figure.

That is, in the characteristic (characteristic of the dotted line) of the conventional example 2, in the attenuation band (frequency f _r ), the 20 dB attenuation bandwidth (Δf1) is narrow and the maximum attenuation is not large. In the pass band (frequency f _p), the insertion loss is large.

[0054] shown in, for the characteristic of the conventional example 2
In the characteristics of the embodiment , since the configuration is as described above, the characteristics are as illustrated. That is, the attenuation band (frequency f
_r ), the 20 dB attenuation bandwidth (Δf2) can be larger than the above Δf1 (Δf2> Δf1),
In addition, the maximum attenuation is larger than that of.

[0055] In addition, in the pass band (frequency _{f p)} is,
Thus, the insertion loss can be reduced as compared with. From the above characteristics , it was demonstrated that the high-frequency LC filter of the example achieved higher coil Q compared to the conventional example 2.

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

(Other Embodiments) Although the embodiments have been described above, the present invention can be implemented as follows. : Not limited to high frequency LC filters, but applicable to other LC composite parts using coils, capacitors, and the like.

The number of spacer layers may be any number.

[0064]

As described above, the present invention has the following effects. : If the thickness TL of the layer constituting the coil portion is set to be TL <TO with respect to the thickness TO of the other layers other than the capacitor portion, the winding of the coil per unit length (in this case, the thickness of the layer) Since the number increases (compared to the case where TL = TO), the inductance value of the coil increases.

Since the conductor length of the coil (coil pattern length) does not change, the conductor loss does not change. Therefore, the coil has a high Q. As a result, for example, when a filter is made, the insertion loss is improved.

: High inductance (about 100 nH)
A simple air-core coil can be set in a small module. In addition, the entire module can be reduced in thickness as the coil layer becomes thinner.

Since the high-frequency LC composite component can be made thinner, when the module is made of ceramics, the binder removal and the firing process at the time of manufacture are facilitated. : By providing a spacer layer between the coil and the capacitor, the stray capacitance between the coil and the capacitor can be reduced.

Accordingly, the Q of the coil can be increased, the insertion loss is reduced, and a predetermined attenuation characteristic can be secured.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory view (exploded perspective view of a high-frequency LC filter) of an embodiment of the present invention .

3A and 3B are explanatory diagrams of an embodiment of the present invention . FIG. 3A is a perspective view (external view) of a high-frequency LC filter, FIG. 3B is a cross-sectional view taken along line XY of FIG. 3A, and FIG. 3C is an equivalent circuit.

FIG. 4 is an explanatory diagram (passband characteristics of a high-frequency LC filter) of an embodiment of the present invention .

[Figure 5] is an explanatory view of a prior art, FIG. 5 A conventional example 1
(Sectional view), Fig. 5 B is a diagram showing a conventional example 2 (sectional view).

[Explanation of symbols]

1-1 to 1-7 First to seventh layers (dielectric substrate) of a multilayer substrate
1 ) Fifth layer (spacer layer) 2 Coil pattern (conductor pattern) 3 Capacitor electrode pattern (conductor pattern)

Claims (1)

(57) [Claims] 1. A plurality of dielectric sheets (1-1 to 1-7) comprises a multilayer substrate formed by laminating, part of the multilayer substrate dielectric sheet (1-2 to 1-4)
And a conductor pattern (2) constituting a coil (L) and a conductor pattern (3) constituting a capacitor (C) on another dielectric sheet (1-6, 1-7). In a high-frequency LC composite component in which a capacitor section is provided and the coil section and the capacitor section are arranged at positions facing each other in the stacking direction of the multilayer board, the uppermost conductor set in the coil section in the stacking direction of the multilayer board. Located between the pattern and the bottom conductor pattern
Dielectric thickness of the sheet (1-2, 1-3) a (TL), excluding the capacitor portion, another dielectric sheet having a thickness (T
O) is set to be thinner (TL <TO) , and a space between the coil section and the capacitor section is increased to increase the distance between the coil section and the capacitor section.
A high frequency layer L, wherein a laser layer (1-5) is set.
C composite parts.