JPH0361365B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method of manufacturing a bead filter by passing a signal line through a through hole of a magnetic material such as ferrite beads, and particularly relates to a method of manufacturing a bead filter by passing a signal line through a through hole of a magnetic material such as a ferrite bead. The present invention relates to a method of manufacturing a bead filter device in which bead filters are collectively arranged on a pedestal so as to be suitable for mounting a substrate or the like.

[Conventional technology]

Digitization of signals processed by electronic equipment, etc.
As speed increases, electromagnetic noise generated by electronic devices can propagate to other electronic devices via signal lines and power lines, interfering with their operation, or conversely, electromagnetic noise generated by other electronic devices can interfere with signals. Problems have arisen in which electronic devices are adversely affected by flowing into the electronic devices through power lines and power lines. One of the countermeasures against these noises has recently been the use of a filter, a so-called bead filter, in which a signal line is passed through a magnetic material such as a ferrite bead having a through-hole. However, in the method of manufacturing a bead filter by immediately passing signal lines on a printed circuit board through the through holes of ferrite beads, the manufacturing process is not easy because there are many signal lines and the ferrite beads are small.

Therefore, a bead filter device has been proposed in which a bead filter is housed in a container having the same terminal arrangement as a general integrated circuit package so as to be suitable for use by being attached to a printed circuit board or the like. This bead filter device connects an electric wire inserted through a through hole of a ferrite bead to the inner protruding end of an external connection terminal of a container with a terminal by soldering.
It is manufactured by fixing ferrite beads with adhesive.

[Problem that the invention seeks to solve]

Such a manufacturing method has the disadvantage that assembly work is complicated and takes a long time, and automation of the work is difficult.

[Means for solving problems]

In the present invention, as components, a plurality of magnetic bodies having through holes, a pedestal made of an insulating material, and a flat lead frame are prepared. The pedestal has a first recess of the same number as the number of magnetic bodies provided along the opposing side wall at a predetermined interval so that the magnetic body can fit therein, and a center penetrating hole provided at the bottom of the first recess. It has a small hole and a second recess provided on the upper surface at positions equidistant from the first recesses adjacent to each other. The lead frame includes a central connecting conductor portion having a length approximately equal to the distance between the opposing end walls of the pedestal, and a central connecting conductor portion extending from the central connecting conductor portion to both sides in a direction orthogonal to the length direction of the pedestal. The central through-holes are arranged at substantially equal intervals to the intervals between the first recesses adjacent to each other along the opposing side walls of the upper surface, and have at least a width on the tip end side provided at the bottom of the first recess; and a band-shaped conductor portion having a diameter equal to or less than the diameter of the through-hole of the magnetic material.

The present invention provides a step of fitting the magnetic material into the first recess of the pedestal with its through hole visible from the top and bottom sides of the pedestal, and a step of inserting the band-shaped conductor portion of the lead frame into the first recess of the pedestal. A step of forming both leg portions by bending the two leg portions at right angles to the same side at a position approximately equal to the interval between the first concave portions facing each other along the end wall direction of the pedestal; and The lead frame, excluding both legs, is attached to the pedestal so that the lead frame, excluding both legs, is inserted through the through hole and the central small through hole provided at the bottom of the first recess, and its tip protrudes from the bottom surface of the pedestal. inserting the conductor until it abuts the top surface; and cutting the central connecting conductor of the lead frame at approximately the midpoint between the strip conductor parts adjacent to each other in the length direction to form a tongue part; The method includes the step of bending the formed tongue portion along the upper edge of the second recess into the second recess.

[Effect]

Pass both legs of the strip-shaped conductor part of the rib-like lead frame through the through-hole of the magnetic material fitted into the first recess of the pedestal, cut the central connecting conductor part of the lead frame at a predetermined position, and insert it into the second recess. By folding it, it can be divided into a plurality of bead filters and attached to a pedestal, and the ends of both legs protrude from the bottom of the pedestal so that they can be easily mounted on a printed circuit board as external connection terminals.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an external perspective view showing the structure of an embodiment of a bead filter device manufactured according to the present invention;
FIG. 2 is an exploded perspective view of FIG. 1, showing the structure of the parts constituting FIG. 1. In the figure, 1 is a rectangular base made of an insulating material, 2 is a ferrite bead as a magnetic material having a through hole, and 3 is a lead frame.

The pedestal 1 is provided with eight recesses 11 on each side at regular intervals along both long side walls (for example, so that the axes of the recesses 11 are in the same arrangement as the terminal arrangement of the integrated circuit package). There is a small central through hole 12 at the bottom (partially shown in FIG. 2).
is installed vertically. The recess 11 has a required depth larger than the height of the ferrite beads 2. Furthermore, rectangular recesses 13 (seven in the figure) are bored in the upper surface of the pedestal 1 at the intersections of diagonal lines connecting four adjacent recesses 11. The depth dimension of the rectangular recess 13 is set to be more than half the length of the upper edge of the rectangular recess 13 in the direction parallel to the long side of the pedestal 1.

The lead frame 3 has a rib-like shape in which a pattern of band-shaped conductors 31 of a predetermined length with wide portions at two middle locations are formed at regular intervals, and the conductors 31 are connected to each other by a central connecting conductor 32 at the center. ,
It is made by punching or chemical etching using a highly elastic and electrically conductive metal plate such as phosphor bronze or beryllium copper. In the state of eight series of strip-shaped conductors 31 corresponding to No. 11, and the strip-shaped conductors 31
It is used in a state in which both ends of the leg portions 33 are bent at the middle wide portion on the same side into a U-shape (shape in the figure).

Next, the assembly of the bead filter device will be explained.

As shown in FIG. 2, the ferrite bead 2 is fitted into the recess 11 of the pedestal 1, and then both legs 33 of the lead frame 3 are inserted into the center hole of the ferrite bead 2 and the center through-hole 12 at the base of the strip conductor 31. ) until it contacts the top surface of the pedestal 1 (therefore, the tips of both legs 33 protrude from the bottom surface of the pedestal 1), then press-fit a jig (not shown) into the seven rectangular recesses 13 at the same time. cut the central connecting conductor 32 in the middle,
Then, the tongue-shaped conductor 32 is folded inward along the upper edge of the rectangular recess 13 (see FIG. 1) to bring it into close contact with the inner wall of the rectangular recess 13, and the eight band-shaped conductors 3
A bead filter device is made by attaching the bead filters 1 to the base 1 independently from each other. As shown in FIG. 2, a notch 34 is made in the center of the central connecting conductor 32 from both sides to make it narrow, so that the tip of the press-fitting jig comes into contact with this narrow part.

Note that the band-shaped conductor 31 can be firmly attached to the pedestal 1 by bonding the band-shaped conductor 31 and the upper surface of the pedestal 1 with an adhesive or the like, or by injecting and solidifying an embedding resin into the rectangular recess 13. Further, the upper part of the pedestal may be covered with a box-shaped lid (not shown) that fits onto the pedestal 1.

Since the wide transition portions at the bases of both legs 33 of the band-shaped conductor 31 come into contact with the upper inner peripheral edge of the ferrite bead 2 and suppress the movement of the ferrite bead 2 within the recess 11, it is not necessary to fix the ferrite bead 2 within the recess 11. do not have.

〔Effect of the invention〕

As described above, according to the present invention, ferrite beads are arranged all at once on a pedestal and a lead frame that is easy to handle is used, so the process is simple and the beads are suitable for mounting on printed circuit boards, etc. The assembly time of the filter device can be shortened and the assembly can be automated.

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing the structure of an embodiment of a bead filter device manufactured according to the present invention;
FIG. 2 is an exploded perspective view of FIG. 1, showing the structure of the parts constituting FIG. 1. 1... Insulating pedestal, 2... Ferrite beads,
3...Lead frame, 11...Recess, 12...
Central through-hole, 13... rectangular recess, 31... band-shaped conductor, 32... center connecting conductor, 33... both legs.

Claims (1)

[Claims] 1 The base includes a plurality of magnetic bodies having through holes, a pedestal made of an insulating material, and a flat lead frame, and the pedestal is provided at predetermined intervals on the upper surface along the opposing side wall so that the magnetic body can be fitted therein. a number of first recesses equal to the number of the magnetic bodies, a central through hole provided at the bottom of each of the first recesses, and a central through hole provided at a position equidistant from the first recesses adjacent to each other on the upper surface; the lead frame has a central connecting conductor portion having a length approximately equal to the spacing between opposing end walls of the pedestal; The first concave portions extend on both sides in a direction perpendicular to the length direction, are arranged at substantially equal intervals to the intervals between the first concave portions adjacent to each other along the opposite side walls of the upper surface of the pedestal, and have at least a width on the tip end side of the first concave portions. The magnetic material is placed in the first recess of the pedestal. a step of fitting the magnetic material into the through-hole in a state visible from the top and bottom sides of the pedestal; and inserting the band-shaped conductor portion of the lead frame into the first recess facing each other along the direction of the end wall of the pedestal. a step of bending the legs at right angles to the same side at positions approximately equal to the spacing between the legs, and bending the legs at right angles to the same side at positions approximately equal to the spacing of a step of inserting the lead frame, excluding the leg portions, into the top surface of the pedestal so that the lead frame, excluding the leg portions, comes into contact with the top surface of the pedestal; cutting the connecting conductor at approximately the midpoint between the strip-shaped conductor portions adjacent to each other in the length direction to form a tongue portion; and placing the formed tongue portion above the second recessed portion. and bending the second concave portion along the edge thereof.