JPH0448015Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a multi-terminal noise filter used to remove high frequency noise.

(Prior Art) A conventional multi-terminal noise filter is constructed as shown in FIGS. 5 and 6. FIG. 5 is a perspective view of the multi-terminal noise filter, and FIG. 6 is a plan view thereof.

In these figures, 1 is a capacitor base material, and electrodes 2,
3. 4 is a ground side lead terminal connected along one of the electrodes 2.
Reference numerals 5 and 6 denote a pair of hot line side lead terminals connected along the other electrode 3, and the side connected to the electrode 3 is connected in a U-shape. The lower end sides of these lead terminals 4, 5, and 6 are each pulled out in the same direction. 7 is an insulating protection material that covers the capacitor base material 1.

A multi-terminal noise filter with such a configuration has an equivalent circuit as shown in Figure 7.
The earth side lead terminal 4 is grounded, and the pair of hot line side lead terminals 5 and 6 are connected to the signal line for use.

(Problem to be solved by the invention) In the conventional multi-terminal noise filter as described above, the three lead terminals 4, 5, and 6 are provided in a straight line along the electrodes 2 and 3 surfaces, respectively.
The book's lead terminals are arranged so that the cross section connecting them is triangular. Therefore, there was a problem in that it was difficult to chuck the lead terminals 4, 5, and 6 using an existing automatic insertion machine that handles two-terminal type components, making it difficult to attach them to a printed circuit board.

Furthermore, although the conventional multi-terminal noise filters as described above have excellent characteristics in a high frequency range, they do not necessarily have sufficient characteristics.

This idea was created in view of the problems mentioned above, and allows for attachment to printed circuit boards using existing automatic insertion machines, as well as a multi-terminal design with even better characteristics in the high frequency range. The purpose is to provide a noise filter.

(Means for solving the problem) In order to achieve the above-mentioned purpose, the multi-terminal noise filter of this invention has a ground side lead terminal provided along one electrode surface of the capacitor base material, and a pair of hot line side The lead terminal is inserted into the through hole of a pair of ferrite beads arranged along the other electrode surface, and the lower end thereof is bent toward the ground side lead terminal side, and the lead terminal is bent in the direction along the ground side lead terminal. , the lower ends of the ground side lead terminal and the pair of hot line side lead terminals are arranged in the same plane.

(Function) Since the lower end sides of the ground side lead terminal and the pair of hot line side lead terminals are arranged in the same plane, attachment to the printed circuit board using an existing automatic insertion machine is possible.

In addition, while the inductance of the ground side lead terminal is the same as that of the conventional one, the inductance of the hot line side lead terminal in the high frequency range is due to the fact that the hot line side lead terminal is inserted into the through hole of the ferrite bead. By arranging the hot line side lead terminal along the electrode surface of the capacitor base material, the length of the hot line side lead terminal inserted into the through hole is increased;
Also, the length of the hot line side lead terminal is made longer by bending the hot line side lead terminal toward the ground side lead terminal side, which makes the hot line side lead terminal longer than the conventional one. Therefore, the characteristics as a noise filter in a high frequency range become more excellent.

(Example) An example of this invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view of the multi-terminal noise filter of this invention, FIG. 2 is a sectional side view of the main part thereof, and FIG. 3 is a plan view thereof. In these figures, 1 is a flat capacitor base material made of a dielectric material, etc.;
2 and 3 are electrodes provided on both sides of the capacitor base material 1 so as to face each other. 4 is a ground side lead terminal connected along the 2 sides of one electrode, 5 and 6 are a pair of hot line side lead terminals connected to the other electrode 3, and the side connected to electrode 3 is connected in a U shape. It is what was done. 8,8
are ferrite beads arranged along the surface of the other electrode 3, and have through holes 8a, 8a in the axial direction.
was formed. The pair of hot line side lead terminals 5, 6 are inserted into the through holes 8a, 8a of the ferrite beads 8, 8, and are bent toward the ground side lead terminal 4 at their lower ends. Further, the pair of hot line side lead terminals 5 and 6 are bent in the direction along the ground side lead terminal 4,
The lower end sides of the pair of hot line side lead terminals 5 and 6 are arranged in the same plane. 7 is an insulating protection material that covers the capacitor base material 1 and the ferrite beads 8, 8.

The multi-terminal noise filter of this invention constructed in this manner is used with the earth side lead terminal 4 being grounded and the pair of hot line side lead terminals 5 and 6 being connected in the signal line, as in the conventional one. FIG. 4 is an example of an insertion loss characteristic diagram showing a comparison between the multi-terminal noise filter according to this invention and a conventional one. In this figure, the horizontal axis shows the frequency and the vertical axis shows the attenuation amount, and the solid line (symbol A
Indicated by ) shows the characteristics of the multi-terminal noise filter of this invention, and the broken line (indicated by symbol B) shows the characteristics of the conventional multi-terminal noise filter. From this insertion loss characteristic diagram, it can be seen that the multi-terminal noise filter of this invention has much better characteristics in the high frequency range than the conventional one.
Note that the samples used for this comparison are all made of the same material in common parts and have the same dimensions.

The reason why the multi-terminal noise filter of this invention has such excellent characteristics is as follows. That is, while the inductance of the ground side lead terminal 4 is the same as that of the conventional one, the inductance in the high frequency range of the hot line side lead terminals 5 and 6 is as follows. By inserting the ferrite beads 8, 8 into the through holes 8a, 8a, and by arranging the ferrite beads 8, 8 along the other electrode 3 surface of the capacitor base material 1, the lengths of the lead terminals 5, 6 inserted into the through holes 8a, 8a are determined. It is different from the conventional one because of the fact that the length of the lead terminals 5 and 6 is made longer, and that the length of the lead terminals 5 and 6 is further increased by bending the hot line side lead terminals 5 and 6 toward the ground side lead terminal 4 side. becomes larger compared to The earth side lead terminal 4 of such a multi-terminal noise filter is grounded, one of the pair of hot line side lead terminals 5 and 6 (for example, lead terminal 5) is set as the input side, and the other (for example, lead terminal 6) is set as the output side. Then, when the frequency of the input signal is low, the impedance of the capacitor composed of the capacitor base material 1 and the electrodes 2 and 3 for that signal is large, and the hot line side lead terminals 5,
Since the inductance of 6 is small, the signal passes from one lead terminal 5 on the hot line side to the other lead terminal 6 without being attenuated much. However, when the frequency of the input signal is high, the impedance of the capacitor composed of the capacitor base material 1 and the electrodes 2 and 3 to that signal is small, and the inductance of the hot line side lead terminals 5 and 6 is the same as that of the conventional one. Since the signal is larger than , the signal flows to the ground side lead terminal 4 side, and is effectively attenuated and does not flow much from one lead terminal 5 to the other lead terminal 6 on the hot line side. Therefore, in the multi-terminal noise filter of this invention, the desired low frequency signal in the signal line is passed from one of the hot line side lead terminals 5, 6 to the other, but the high frequency noise component is passed through the ground side lead terminal. It flows toward terminal 4, effectively removing noise from the signal line.

The multi-terminal noise filter of this invention is constructed as in the above embodiment, but some changes may be made as desired. For example, although the hot line side lead terminals 5 and 6 are connected in a U-shape in the above embodiment, they may be independent. In addition, the ground side lead terminal 4 is one in the above embodiment, but it is made into a U-shape and has two, for example, placed between the hot line side lead terminals 5 and 6 to form a four-terminal. It can also be a mold.

(Effects of the invention) Since the multi-terminal noise filter of this invention is configured as explained above, it can be attached to the print substrate using an existing automatic insertion machine, and it has characteristics in the high frequency range. Become better than the.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a multi-terminal noise filter according to an embodiment of this invention, Fig. 2 is a cross-sectional side view of its main parts,
FIG. 3 is a plan view thereof, and FIG. 4 is an insertion loss characteristic diagram showing a comparison between the multi-terminal noise filter according to this invention and a conventional one. FIG. 5 is a perspective view of a conventional multi-terminal noise filter, FIG. 6 is a plan view thereof, and FIG. 7 is an equivalent circuit diagram thereof. 1... Capacitor base material, 2, 3... Electrode, 4
... Earth side lead terminal, 5, 6 ... Hot line side lead terminal, 7 ... Insulation protection material, 8 ... Ferrite bead, 8a ... Through hole.

Claims (1)

[Claims for Utility Model Registration] A ground side lead terminal 4 is connected to one electrode 2 of a capacitor base material 1 provided with electrodes 2 and 3 facing each other on the front and back sides, and a pair of electrodes 2 and 3 are connected to the other electrode 3. In a multi-terminal noise filter in which the hot line side lead terminals 5 and 6 are connected and the lower ends of the earth side lead terminal 4 and the pair of hot line side lead terminals 5 and 6 are pulled out in the same direction, the earth side lead terminal 4 is Capacitor base material 1
The pair of hot line side lead terminals 5 and 6 are provided along the two surfaces of one electrode, and the pair of ferrite beads 8 and 8 are provided along the three surfaces of the other electrode.
is inserted into the through holes 8a, 8a, and is bent toward the ground side lead terminal 4 side at the lower end side,
Moreover, it is bent in the direction along the ground side lead terminal 4, and the lower end sides of the ground side lead terminal 4 and the pair of hot line side lead terminals 5 and 6 are arranged in the same plane. Multi-terminal noise filter.