JPH0715269A - Noise filter - Google Patents

Abstract

PURPOSE:To make automatic assembly possible, to facilitate manufacture, to reduce a substrate mounting area, to lighten the weight as well and to lower the price at the noise filter constituted by connecting circuit elements such as a common mode choke coil, which winds two winding wires around a closed magnetic path magnetic core in the same direction, capacitor, varistor and resistor. CONSTITUTION:A divided cylindrical winding frame 4 with gear is assembled to a O-shaped ferrite core 7, two winding wires 3 are wound, and pin terminals 10 and 20 are inserted and mounted at through holes 16 and 26 on the face of a wiring board 2 connecting and mounting the filter circuit element such as a laminated ceramic capacitor 15, which fits a pin terminal 13 for ground between a gear choke coil 1 fitted to a O-shaped terminal stand 8 with pin terminals 10 and 20 or a bobbin type common choke coil integrated with a U-shaped divided core by winding the two winding wires around an O-shaped bobbin winding frame with pin terminal and a laminated ceramic capacitor 14, to a printed wiring conductor 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise filter used to prevent electromagnetic noise in electronic equipment.

[0002]

2. Description of the Related Art A conventional noise filter uses a common mode choke coil formed by winding two windings in the same direction around a magnetic path of a toroidal ferrite core, a plastic film capacitor or a ceramic capacitor, and a substrate. Instead, the parts are assembled by aerial wiring in which parts are connected with insulation-coated copper wires, or the parts are connected to the printed wiring conductor on the board and connected to the filter circuit, and the metal with external connection terminals provided on the opposite side walls. It is a structure in which a box-shaped container made of resin or resin or a cylindrical container having external connection terminals attached to one end surface is housed.

[0003]

The conventional noise filter has a drawback that the manufacturing cost is high because most of the assembling work is manual work, and there is an electrical insulation between the filter circuit elements housed in the container. Space needed to guarantee
Along with that, there is a disadvantage that the external dimensions are large because it is stored with a wasted space, and in the case of aerial wiring, the embedded resin is injected into the container to fix the circuit element,
There is a drawback that both the shape and the weight become large.

[0004]

The noise filter according to the present invention is a common mode choke coil, which is replaced by a toroidal type, and is a gear choke coil comprising a date-shaped core, a gear split type cylindrical reel and a terminal block with pin terminals. , Surface mount type filter circuit element such as bobbin type common mode choke coil assembled in a king-shaped bobbin winding frame with pin terminals wound with U-shaped core, and chip type ceramic capacitor with ceramic dielectric laminated and sintered And connecting the pin terminals of the four common mode choke coils through which a line current or a signal current flows to a printed wiring conductor for connecting a filter circuit element to form a through hole and insert the through hole into the through hole. In close proximity to the circuit element mounted on the top surface of the wiring board provided with one external connection terminal for grounding,
The pin terminals of the gear choke coil or bobbin type common mode choke coil are inserted through the through holes to form an integrated noise filter.

Alternatively, in addition to a conventional pin terminal through which a line current or a signal current flows, a ground pin terminal is previously provided on a terminal block with a pin terminal of a gear choke coil or a king-shaped bobbin with a pin terminal of a bobbin type common mode choke coil. The common mode choke coil and the circuit element are installed by mounting them in a through hole connected to a printed wiring conductor on a wiring board on which a surface-mountable filter circuit element such as a multilayer sintered ceramic capacitor is mounted. A noise filter is integrated with the mounted wiring board.

That is, according to the present invention, two windings are wound in the same direction on a split type cylindrical winding frame with a gear attached to a central magnetic leg of a date-shaped ferrite core, and the terminal block with a pin terminal is provided with the above-mentioned structure. A common mode gear choke coil with the winding ends connected to the pin terminals, or a king-shaped bobbin bobbin with pin terminals, with two windings applied in the same direction A bobbin type common mode choke coil which is connected to pin terminals, two U-shaped ferrite cores are combined in a rectangular shape on the winding part of the bobbin winding frame, and the U-shaped ferrite core is fixed with a metal holder. ,
The choke coil pin terminals are provided on the wiring board in close proximity to the upper surface of the filter circuit element on the wiring board in which the surface mount type monolithic ceramic capacitor and the filter circuit element such as a varistor or a resistor are connected and mounted by a printed wiring conductor. The noise filter is characterized in that it is inserted and connected to a through hole provided in the printed wiring conductor end, and is attached integrally.

[0007]

[Function] The pin terminals of the gear choke coil or bobbin type common mode choke coil are electrically connected to the printed wiring conductor to which the wiring circuit element connected to the through hole is connected, and the external connection terminal is Form. Further, the gear choke coil and the bobbin type common mode choke coil are arranged on the upper surface of the substrate on which the circuit elements connected by the printed wiring conductors constituting the noise filter are mounted, in the vicinity of the circuit elements. Therefore, the circuit element and the board conductor are covered, the printed wiring conductor and the circuit element are isolated and protected from the external environment, and the circuit element and the common mode choke coil are stacked to form a noise filter with a small board mounting area. .

[0008]

FIG. 1 is a front view showing an embodiment of a noise filter according to the present invention, and FIG. 2 is provided with a gear choke coil 1 of the noise filter shown in FIG. 1, a noise filter component and a printed wiring conductor 12. FIG. 3 is an external perspective view showing a wiring board 2 separated. Further, FIG. 3 is an external perspective view showing separately the noise filter in which the bobbin type common choke coil 17 of the noise filter according to the present invention and the wiring board 2 are combined. FIG. 4 shows an equivalent circuit of the noise filter shown in FIGS. 2 and 3, and pin terminals 1 at both ends of the gear choke coil 1 and the bobbin type common choke coil 17 are shown.
It is a noise filter configured by connecting a laminated ceramic capacitor 14 between 0 and 20 and a laminated ceramic capacitor 15 between the ground pin terminal 13 and the pin terminals 10 and 20. An L type filter is formed, and for normal mode noise, a leakage inductance of the common mode choke coil and the monolithic ceramic capacitors 14 and 15 form a π type noise filter. A line current or a signal current flows between the pin terminals 20 and between the pin terminals 10. The gear choke coil 1 is a common mode choke coil having two windings 3.

In the gear choke coil 1 , a split type cylindrical bobbin 4 with a gear in which a central collar 5 is provided with a gear 6 is fitted to the central magnetic leg of a date-shaped ferrite core 7, and further, the date-shaped ferrite core 7 is provided. It is placed on a square-shaped terminal block 8 having almost the same outer shape, and an adhesive is applied to the concave portion 9 on the side surface of the square-shaped terminal block 8 to fix the date-shaped ferrite core 7 to the terminal block 8, and then the split type cylindrical reel 4 with gears. Is rotated to wind the winding 3.

In the gear choke coil 1 , only the work of twisting the start end of the winding 3 to the pin terminals 10 and 20 is a manual work, and the other work can be automated and made highly efficient. The structure is easy to process. The square-shaped terminal block 8 has four standoff pieces 11.

The wiring board 2 has the same shape and size as the planar outer shape of the square-shaped terminal block 8 and is provided with a required printed wiring conductor 12 which is connected to the pin terminals 10 and 20 to form a filter circuit on the upper surface. It is connected to the printed wiring conductor 12 and has a monolithic ceramic capacitor 15 inserted therebetween and a grounding pin terminal 13 provided vertically.

On this wiring board 2, a monolithic ceramic capacitor 1 having a thickness smaller than the height of the standoff piece 11 is formed.
It is necessary to prevent the standoff 11 and the monolithic ceramic capacitors 14 and 15 from overlapping when the wiring board 2 on which the surfaces 4 and 15 are mounted and the gear choke coil are combined. Off 1
1 may overlap. The two monolithic ceramic capacitors 14 are line-to-line capacitors, and the two capacitors are line-to-ground capacitors.

A gear choke coil is further provided on the wiring board 2.
The pin terminals 10 and 20 of the first through-holes 16 and 2 of the wiring board 2.
Insert the gear choke coil 1 through 6 and pin terminal 1
A board-mounted noise filter in which 0, 20 and the ground pin terminal 13 are external connection terminals is completed. Also, FIG. 1 and FIG.
4 is changed and a surface mount type varistor is inserted in parallel to the monolithic ceramic capacitors 14 and 15, or the monolithic ceramic capacitors 14 on the left side of FIG. By changing the circuit element on the wiring board such as connecting a resistor, it is possible to configure a noise filter in which various circuit elements are combined.

Similarly, in FIG. 3, the bobbin type common choke coil 17 including the U-shaped split core 18, the holder 19, the winding 3, the pin terminal 10 and the king-shaped bobbin winding frame 22 is mounted on the wiring board 2. And pin terminals 10 and 20
Completed a board-mounted noise filter that shares external connection terminals. The ground pin terminal 13 is integrated with the bobbin type common choke coil 17 in the same manner as the pin terminal,
The ground pattern 21 provided on the wiring board 2 is connected to the through hole so as to be connected and shared with the external connection terminal.

[0015]

According to the present invention, the board-mounted gear choke coil and the bobbin-type common choke coil have an easy-to-handle structure, and the surface-mounted capacitor can be automatically mounted on the board. It is a noise filter that can be automated assembling without performing it, and because the container that houses the filter circuit element is not used, the manufacturing cost can be reduced, and the common mode choke coil is placed on the wiring board. Since the terminal is formed so as to be inserted into the through hole connecting to the printed wiring conductor to which the circuit element on the wiring board is connected and shared with the external connection terminal, the board mounting area is small, and the cost is low and the weight is low. It has the effect of providing an easy-to-use noise filter.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a noise filter of the present invention.

FIG. 2 is an exploded perspective view showing an embodiment of the present invention.

FIG. 3 is an exploded perspective view showing another embodiment of the present invention.

FIG. 4 is a circuit configuration diagram of the noise filter shown in FIGS. 2 and 3.

[Explanation of Codes] 1 gear choke coil 2 wiring board 3 winding 4 split type cylindrical reel with gear 5 center collar 6 gear 7 day-shaped ferrite core 8 square shaped terminal block 9 recess 10 and 20 pin terminal 11 standoff piece 12 Printed wiring conductor 13 Ground pin terminal 14,15 Multilayer ceramic capacitor 16,26 Through hole 17 Bobbin type common choke coil 18 U-shaped split core 19 Holder 21 Through hole 22 King bobbin winding frame

Claims (1)

[Claims] 1. A split type cylindrical bobbin with a gear attached to a central magnetic leg of a day-shaped ferrite core is provided with two windings in the same direction, and a terminal block with pin terminals is provided with the windings of the windings. A common mode gear choke coil with a winding terminal connected to a pin terminal, or a king-shaped bobbin winding frame with a pin terminal, and two windings are applied in the same direction so that the winding terminal is a pin terminal. Surface mount a bobbin type common mode choke coil in which two U-shaped ferrite cores are connected to the winding part of the king-shaped bobbin winding frame in a rectangular shape and the U-shaped ferrite core is fixed with a metal holder. Type monolithic ceramic capacitor and a filter circuit element such as a varistor or a resistor are connected and mounted by a printed wiring conductor, and the pin terminals of the choke coil are placed close to the upper surface of the filter circuit element. A noise filter characterized by being inserted and connected to a through hole provided in the printed wiring conductor terminal provided on a wiring board, mounted and integrally assembled.