JPS62152111A - High frequency coil - Google Patents

Abstract

PURPOSE:To obtain a very thin type multilayer coil having an electromagnetic shielding function by a method wherein the proximity arrangement of a coil and an electromagnetic shielding conductor can be made possible by providing a solenoid coil, with which the magnetic flux is generated in parallel with the surface of a substrate, on a multilayer circuit substrate. CONSTITUTION:A multilayer circuit substrate is composed of the insulating layers 2 pinched by conductive layers 1A, 1B-1G and each conductive layer. Lines 3A and 3B-3D/4A-4C in parallel with each other are provided on the conductive layers 1B and 1C, the starting points of the lies 3A and 4A are electrically connected using a through hole 5A, and the ending points of the lines 3B and 4A are electrically connected using a through hole 5E. A solenoid type coil having rectangular cross section is formed by successively connecting the starting point and the ending point of each lines as above-mentioned through the intermediary of the insulating layers 2, and also the coil electrodes 8A and 8B provided on the electromagnetic shielding conductor layer 1A are connected to the end part of the coil. As a result, the direction of the magnetic flux generated on the coil is brought in parallel with the surface of the substrate, and the shielding conductive layer 1A can be arranged in close vicinity to the coil without having no influence of the effect of the coil.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high frequency printed coil using a multilayer circuit board.

Conventional technology In recent years, there has been a remarkable trend toward smaller and thinner electronic devices, and as a result, there has been an extremely strong demand for smaller and thinner high-frequency circuit blocks that make up these devices, such as receiver front-end sections and tuner sections. It has become.

The main challenges for making these high-frequency circuits smaller and thinner are making the coil smaller and thinner, establishing thin electromagnetic shielding technology, making the adjustment circuit elements smaller and thinner, such as trimmer capacitors, etc. There are some ways to eliminate adjustment by devising the circuit.

Among the above-mentioned problems, many attempts have been made to reduce the size and thickness of coils, and progress has been particularly remarkable in the field of chip coils and printed coils with leadless structures.

Since the present invention relates to a printed coil, a conventional printed coil will be described first.

FIG. 3 shows a pattern of a planar printed coil, which has been commonly used in the high frequency field.

In FIG. 3, 11 is a circuit board, and 12 is a conductive pattern formed on its surface, which functions as a printed coil. The center of the 12 conductor patterns, together with the outermost end of the conductor pattern, becomes the coil terminal, so when in use it is connected to other circuit parts using through holes or jumper wires, but the details are not shown in the figure. will be omitted.

Problems to be Solved by the Invention The problem with the planar printed coil shown in Figure 3 is that the main part of the magnetic flux generated by the current flowing through the coil occurs in a direction perpendicular to the circuit board surface, so it is close to the circuit board that has this coil part. However, when a conductor or magnetic material is placed, the inductance and Q of the coil change significantly, making it difficult to provide a thin electromagnetic shield. Similarly, it is difficult to make the coils multi-layered.

An object of the present invention is to eliminate the above-mentioned drawbacks and provide a multilayer high-frequency coil having an electromagnetic shielding function.

Means for solving the problem The two opposing inner conductor layers (hereinafter referred to as the second
, third conductor layer), each line of the second and third layer parallel conductors (hereinafter each line is referred to as the first, second, . . . from the end). The starting points of the second and third conductor layer Nth lines face each other between the second conductor layer Nth line and the third conductor layer Nth line (referred to as the Nth line).
N-1) Form a parallel conductor with a certain angle so that each end point of the line faces each other, and form a through hole at each opposing start point and end point of each line of the second and third conductor layers. By connecting, a solenoid type coil having a rectangular cross section is formed, and another conductor layer provided adjacent to the second and third conductor layers is used as a shield layer having the role of electromagnetic shielding for the coil. . Also, similar shielded coils are stacked to form a multilayer structure.

Function The present invention forms a thin solenoid-like coil having a rectangular cross section as described above, and causes the main part of the magnetic flux generated by the current flowing through the coil to be generated in a direction parallel to the circuit board surface. Even if a conductor layer is arranged, the influence of the conductor layer is reduced, thereby realizing a high frequency coil with thin electromagnetic shielding, and further increasing the density by forming multiple layers.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view conceptually showing the structure of the high-frequency coil of the present invention. In Figure 1, IA is the first layer of the seven-layer circuit board.
Conductor layer, IB, 1c, 1. are respectively the second. Third. A fourth conductor layer is shown, 2 is an insulating layer sandwiched between these conductor layers, 3A, 3B, 3o.

3. The first parallel conductor formed using the second conductor layer IB. Second. Third. The fourth line +4AI'48.4o is the first parallel conductor formed using the third conductor layer 1°. Second. The third line, 5A-5° and 5°-5F, respectively,
Each line 3A-3 of parallel conductors. and a through hole 6A for electrically connecting the ends of each starting point and ending point of 4A to 4o.

6B is a through hole 8A for electrically connecting the ends of the parallel conductors formed in the second conductor layer and the third conductor layer in order to take out the coil electrode to the outside.

8B shows a part of the first conductor layer used for electromagnetic shielding where a part is removed in an island shape and a coil electrode provided thereon.

1F8. , IF, and Io are respectively 5th. 6th. 2 indicates a seventh conductor layer, and 2 is an insulating layer sandwiched between these conductor layers;
13A, 138.13o, 13. are the first, second, . . . of parallel conductors formed using the fifth conductor layer IB. Third. 4th line, 14A, 14B.

14o is the first parallel conductor formed using the sixth conductor layer IF. Second. 3rd line, 15A~15° and 15D
~15F are parallel conductor lines 13A~13. Through holes 14A to 14G are used to electrically connect the ends of the starting and ending points, and 16A and 16B are parallel conductors formed in the fifth and sixth conductor layers in order to take out the coil electrodes to the outside. A through hole 7 for electrically connecting the ends of the first through hole 7 is used for electromagnetic shielding.
A conductive layer and a fourth layer also used for electromagnetic shielding.
Through holes 18A and 188 are for electrically connecting the conductor layer and the seventh conductor layer, which is also used for electromagnetic shielding. shows the removed part and the installed coil electrode.

Figure 2 is a perspective view of the external appearance of a high-frequency coil with a shielding function in which the coil is formed inside the 7R circuit board shown in Figure 1. This is the same thing, so detailed explanation will be omitted.

By forming a thin solenoidal coil in the multilayer circuit board as described above, the main magnetic flux generated by the current flowing through the coil is confined to the insulating layer between the second and third conductor layers and the insulating layer portion in the vicinity. Therefore, even if the conductor layer for electromagnetic shielding is placed close to the coil, the coil is not strongly affected by it, making it possible to have multiple layers, and it is possible to obtain a multilayer high-frequency coil with thin electromagnetic shielding.

In the above explanation, an example was explained in which the coil electrodes are led out to the first conductor layer and the seventh conductor layer, but design changes such as leading out to the side of the board can be easily made depending on the purpose of use. Needless to say.

Furthermore, it goes without saying that three or more coils can be stacked using the same procedure.

Also, the first one for electromagnetic shielding. 4th. Although no particular mention was made of the electrode for connecting the seventh conductor layer to the ground of the circuit, it is easy to understand that it may take various forms depending on the purpose of use.

Furthermore, in the embodiment, the first one for electromagnetic shielding. 4th I explained the method of connecting the 7th conductor layer with one through hole, but this is to make the drawing f + JjtL, and it is better to provide a large number of through holes around the coil for better shielding. Of course, the effect is the same as above. It goes without saying that the present invention includes modifications such as providing a tap at any point on the coil depending on the purpose of use.

Effects of the Invention As described above, the present invention forms a solenoid-shaped coil with a rectangular cross section in a multilayer circuit board, so that an electromagnetic coil conductor can be placed close to the coil, and the multilayer circuit board can be utilized. As a result, an extremely thin multilayer high-frequency coil with an electromagnetic shielding function can be formed.

[Brief explanation of drawings]

Fig. 1 is a perspective view conceptually showing the structure of a high-frequency coil according to an embodiment of the present invention, Fig. 2 is a perspective view showing the external appearance of the high-frequency coil based on Fig. 1, and Fig. 3 is a conventional planar printed coil. FIG. IA, IB, io, ID, IB, IF, 1o...
・Conductor layer, 2...Insulating layer, 3A to 3D, 13A
~13,. 4A-4o, 14A-14G...Parallel conductor, 5A-5F, 6A, 6B, 15A-15F. 16A, 16B, 7...Through hole, 8A. 88.18A, 19.・・・・・・Coil electrode. Name of agent: Patent attorney Toshio Nakao (1 person) Figure 1

Claims (3)

[Claims] (1) When forming interrupted parallel conductors in two opposing inner conductor layers (hereinafter referred to as the second conductor layer and third conductor layer) of a multilayer circuit board, the second conductor layer parallel conductor Between the grid line and each line of the third conductor layer (hereinafter, each line of the parallel conductor is referred to as the first line, second line, third line, etc. sequentially from the end), the second Nth line of the conductor layer and Nth line of the third conductor layer (N is a positive integer starting from 1)
forming the parallel conductors at a certain angle so that the starting points of the Nth line of the second conductor layer and the (N-1)th line of the third conductor layer face each other; 2nd above
The parallel conductors formed in the second conductor layer and the third conductor layer and the second conductor are connected by through-hole connecting the mutually opposing starting points and end points of each line of the conductor layer and each line of the third conductor layer, respectively. and a second insulating layer between the third conductive layer and the through hole to form a solenoid-type first coil having a rectangular cross section, and at a position sandwiching the second conductive layer from the second insulating layer. a first insulator layer provided, a first conductor layer provided at a position sandwiching the first insulator layer from the second conductor layer, and a third conductor layer sandwiching the third conductor layer from the second insulator layer. a third insulator layer provided at a position sandwiching the third insulator layer from the third conductor layer, and a fourth conductor layer provided at a position sandwiching the third insulator layer from the third conductor layer; The conductor layer is a shield layer having an electromagnetic shielding role for the first coil, and the second conductor layer, the third conductor layer, the fourth conductor layer, the first insulator layer, and the first insulator layer in the first coil. A fifth conductor layer, a sixth conductor layer, a seventh conductor layer, a fourth insulator layer, a fifth insulator layer with the same structure as the second insulator layer and the third insulator layer, respectively.
a sixth insulator layer, a fourth insulator layer, a fifth conductor layer, a fifth insulator layer, a sixth conductor layer, a sixth insulator layer at a position sandwiching the fourth conductor layer from the third insulator layer; , a seventh conductor layer, and a fifth conductor layer, a sixth conductor layer, and a fifth conductor layer, similar to the first coil.
a second coil formed by an insulating layer;
A high-frequency coil characterized in that a conductor layer and a seventh conductor layer are used as a shield layer having a role of electromagnetic shielding for the second coil, and a plurality of coils are stacked in a multilayer manner using the same procedure. (2) The high-frequency coil according to claim 1, wherein a large number of through-hole connections are provided between the conductors of each shield layer in the periphery of the coil in order to enhance the shielding effect of the coil. (3) The high-frequency coil according to claim 1, wherein a tap is provided at an arbitrary portion of each coil.