JPH0536533A - High-frequency coil - Google Patents

Abstract

PURPOSE:To manufacture a coil in high Q factor and gigh self-resonance frequency in relation to the title high-frequency coil. CONSTITUTION:A coil pattern 11-1 on the first layer 10-1 of a multilayered substrate and another coil pattern 11-2 on the second layer 10-2 are connected to be in the same high-frequency potential (between a-c, b-d) as a double conductor, likewise, a coil pattern 11-3 on the third layer 10-3 and another coil 10-4 on the fourth layer 10-4 are connected in the same high-frequency potential (between e-g, f-h) to be another double conductor. Finally said double conductors (between d-e) are connected so that the double conductors as a whole may be wound up in a helical coil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency coil and is used as an LC resonator such as a high frequency oscillator or a high frequency filter used in a high frequency band of 400 MHz or more.

[0002]

2. Description of the Related Art FIG. 3 is an exploded perspective view of a conventional high frequency oscillator module. In the figure, 1-1 is the first layer of the multilayer substrate, 1-2 is the second layer of the multilayer substrate, 1-3 is the third layer of the multilayer substrate, 2 is a component (discrete component), 3-1.
Indicates a first coil pattern, and 3-2 indicates a second coil pattern.

Conventionally, a high-frequency oscillator module using an LC resonator having a coil patterned on a substrate has been considered. One example thereof will be described with reference to FIG. In this example, a coil is patterned and built in a multilayer substrate, and an LC resonator is configured by this coil, and an oscillator is configured by using the LC resonator.

As shown in the figure, components (discrete components) 2 such as a transistor, a resistor and a capacitor that constitute an oscillator are mounted on the first layer 1-1 of the multilayer substrate. In addition, the coil pattern 3 is formed on the second layer 1-2 of the multilayer substrate.
-1 is formed of a thick film conductor, and the coil pattern 3-2 is formed of a thick film conductor on the third layer 1-3. Furthermore, the fourth layer 1
The component 2 is mounted on the lower side (outer surface) of -4.

Between the coil patterns 3-1 and 3-2,
A blind through hole (a through hole whose inside is filled with a conductor) is used for connection (dotted line portion in the drawing) to form one helical coil L. The helical coil L is a coil that constitutes an LC resonator and is connected to other components and the like.

[0006]

SUMMARY OF THE INVENTION The above-mentioned conventional device has the following problems. (1) When an oscillator or filter in a high frequency band (400 MHz or more) is formed by using an LC resonator with a coil patterned on a substrate, the characteristics of the LC resonator depend on the Q of the coil and the self-resonant frequency. Will end up.

In order to use the patterned coil with high Q, it is preferable to use a helical coil as in the conventional example. However, due to the structure of the helical coil, the self-resonant frequency is in the low frequency region around the operating frequency or lower. Therefore, it is difficult to realize a coil having a high Q and a high self-resonant frequency.

(2) The self-resonance frequency can be increased by reducing the width of the coil pattern. However, in this case, since the conductor resistance of the coil pattern increases, the Q of the coil decreases.

(3) When the width of the coil pattern is widened, the property opposite to the above (2) is obtained. That is, if the width of the coil pattern is widened, the resistance is lowered, but the capacitance between the coil patterns is increased and the self-resonance frequency is lowered.

(4) When forming the coil pattern, it is possible to form the coil pattern thicker by printing the thick film conductor a plurality of times to reduce the resistance of the coil pattern.

However, if the coil pattern is made extremely thick, the dielectric layers to be laminated cannot absorb the conductor thickness of the coil pattern. Therefore, peeling occurs between the layers of the multilayer substrate.

Further, the smoothness of the surface of the substrate cannot be obtained, and the printability of the surface conductor and the printing resistor is deteriorated. An object of the present invention is to solve such a conventional problem and to realize a coil having a high Q and a high self-resonance frequency.

[0013]

In order to solve the above problems, the high frequency coil of the present invention has the following structure.
That is, it is a high frequency coil comprising a plurality of coil patterns respectively provided on a plurality of dielectric layers, and the coil patterns on a plurality of adjacent dielectric layers among the coil patterns have the same potential. The coil patterns were connected to form a multi-conductor coil pattern, and a plurality of the multi-conductor coil patterns were connected to form a helical coil.

[0014]

The operation of the present invention based on the above construction will be described. When constructing a coil for high frequency, as in the above configuration, a coil pattern having a double conductor is helically wound. Therefore, even if the pattern width of each coil pattern is narrowed, the resistance value of the entire double conductor can be suppressed to a small value.
As a result, even if the pattern width is narrowed and the self-resonant frequency is increased, Q can be prevented from decreasing.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a multilayer substrate in which a coil is patterned according to an embodiment of the present invention, and FIG. 2 is a sectional view of a multilayer substrate in which a coil is patterned and a connection state explanatory diagram of the coil.

In the figure, 10-1 to 10-4 are first to fourth layers (dielectric layers) of the multilayer substrate, 11-1 to 11-4 are coil patterns, and a to h are points of the coil pattern. Indicates. The high frequency coil of this embodiment is used as a high frequency oscillator module as shown in FIG. 3, for example. 1 and 2, only the coil portion is shown.

As shown, the first layer 10-1 of the multilayer substrate
A coil pattern 11-1 is formed on the second layer 10-
The coil pattern 11-2 is formed on the second layer 10 and the third layer 10 is formed.
A coil pattern 11-3 is formed on -3, and
A coil pattern 11-4 is formed on the fourth layer 10-4.

Each of the coil patterns 11-1 to 11-4
Is formed as a thick film conductor pattern (printing pattern) on each layer (dielectric layer) of the multilayer substrate, and the coil patterns 11-1 and 11-2 have the same shape. 11-4 have the same shape.

The coil patterns are connected by blind through holes at the positions indicated by the dotted lines in the figure.
That is, the points a and c, the points b and d, the points d and e, the points e and g, and the points f and h are respectively connected.

In this way, the two points connected as described above are electrically short-circuited, so that the coil pattern 11-
1 and 11-2 are coil patterns of the same potential in terms of high frequency,
The coil patterns 11-3 and 11-4 are high-frequency coil patterns having the same potential.

Therefore, the coil patterns 11-1 and 11-
2 forms a double conductor (double conductor in this case), and the coil patterns 11-3 and 11-4 form a double conductor. Then, the coil patterns formed into the double conductor are connected at the points (between d and e) to form a helical coil as a whole.

In this case, in particular, as shown in FIG. 2B, a coil of one turn is constituted by a double conductor composed of coil patterns 11-1 and 11-2, and coil patterns 11-3 and 11-4. 1 with a double conductor consisting of
Make up a coil of turns.

Therefore, by connecting between the multiple conductors, a helical coil having a two-turn double conductor is formed. By doing so, even when the width of each coil pattern is narrowed and the self-resonance frequency is set high,
Since the resistance value as a multiple conductor can be kept low,
A coil having a high Q and a high self-resonant frequency can be obtained.

Since a coil used in a high frequency band of 400 MHz or more is about 40 nH or less, it is sufficient to cover about 2 to 3 turns though it depends on the diameter of the coil to be patterned. Therefore, even if the helical coil is a double conductor of two conductors or three conductors, the number of laminated layers is not difficult to manufacture.

In addition, between the coil patterns of double conductor,
Since the dielectric layer may be thin (because the coil pattern has the same potential in terms of high frequency), even if the number of laminated layers increases, overall,
The multilayer board does not become extremely thick. Furthermore, since the coil pattern is formed separately for each dielectric layer, the dielectric layer can sufficiently absorb the thickness (coil pattern) of the conductor layer.

(Description of Other Embodiments) The embodiments have been described above, but the present invention can also be implemented as follows. (1) The high frequency coil according to the present invention may be a coil that constitutes an LC resonator such as an oscillator or a filter, or may be a chip component having only the coil.

(2) The number of turns (the number of turns) of the coil may be any number as long as the helical coil can be constructed. (3) The number of double conductors may be arbitrary as long as it is 2 or more (for example, 3
It may be a helical coil made of a conductor).

[0028]

As described above, the present invention has the following effects. (1) A coil having a high Q and a high self-resonant frequency can be obtained even in a high frequency band of 400 MHz or more. (2) In the high frequency band, an oscillator, a filter or the like using the LC resonator of the high frequency coil of the present invention can be designed without difficulty.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a multilayer substrate in which a coil is patterned according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a multi-layer substrate in which a coil is patterned and a connection state explanatory diagram of the coil.

FIG. 3 is an exploded perspective view of a conventional high frequency oscillator module.

[Explanation of symbols]

10-1 to 10-4 First layer to fourth layer (dielectric layer) of multilayer substrate 11-1 to 11-4 Coil pattern

Claims (1)

Claims: 1. A plurality of dielectric layers (10-1 to 10-4).
A plurality of coil patterns (11-1
11-4), wherein a plurality of dielectric layers (1) adjacent to each other in the coil pattern are provided.
0-1 and 10-2, and 10-3 and 10-4) coil patterns (11-1 and 11-2 and 11-3 and 11-).
A coil for high frequency, wherein 4) is connected so as to have the same potential in a high frequency to form a coil pattern of multiple conductors, and a plurality of the coil patterns of the multiple conductors are connected to form a helical coil.