JPH06302435A - High frequency transformer - Google Patents

Abstract

PURPOSE:To automate the manufacture by arranging the magnetic core on a printed wiring board, and providing a lead wire astride this magnetic core, and inserting both ends into the small holes made in a printed wiring board, and connecting one end of one hand of adjacent lead wires, inserted from one side and projected on the other side, with the other end of the other of them zigzag by means of a wiring pattern. CONSTITUTION:A magnetic core 22 is arranged on a printed wiring board 21, and a plurality of jumper lines 23 are arranged nearly parallel astride one side of the magnetic core 22, and both ends of each jumper line 23 are inserted into the small holes made in the board 21. And, a printed wiring pattern 25 is made on the opposite face from the face where the magnetic core 22 is provided, and one end of one hand of adjacent jumper lines 23 and the other end of the other hand are connected with each other by a wiring pattern 25, severally, in order, and a primary coil 26 is constituted by solder 30. Likewise, a secondary coil 29 is constituted of jumper lines 27 and the wiring patterns 28 of the board 21, on the side opposite to the side where the coil 26 of the magnetic core 22 is wound. Hereby, the manufacture can be automated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency transformer mounted on a printed wiring board.

[0002]

2. Description of the Related Art A conventional high frequency transformer of this type is shown in FIG. That is, the bobbin 12 is inserted through the central portion 11A of the sun-shaped magnetic core 11, and the coil 13 is wound on the bobbin 12. Although not shown in the figure, the coil 13 has a primary winding and a secondary winding, which form a transformer. The magnetic core 11 is arranged on the wiring board 14 so that the axis of the bobbin 12 is perpendicular to the wiring board 14, and the terminal 16 mounted by projectingly formed on the collar 15 of the bobbin 12 on the wiring board side is wired. It is inserted into the board 14 and soldered to the wiring pattern.

[0003]

In a conventional high frequency transformer, a primary coil and a secondary coil are wound on independent bobbins, and a magnetic core is inserted into the bobbin to form a closed magnetic circuit. Since the transformer is assembled and then attached to the wiring board, there is a problem that the number of manufacturing steps is relatively large.

[0004]

According to the present invention, a magnetic core is arranged on a wiring board, and both ends of a plurality of conducting wires are inserted into the wiring board across the magnetic core, and the conductor is provided on the opposite surface of the wiring board. The formed wiring pattern sequentially connects one end and the other end of adjacent conductors to form a coil.

[0005]

1 shows an embodiment of a high frequency transformer according to the present invention. In this example, a rectangular ring-shaped magnetic core 22 is arranged on a printed wiring board 21, and a plurality of jumper wires 23 bent in a U-shape as conductors are arranged substantially parallel to each other across one side of the magnetic core 22. Both ends of each jumper wire 23 are inserted into a small hole formed in the wiring board 21. Further, in this example, the insulating layer 24 is interposed between the jumper wire 23 and the magnetic core 22. The insulating layer 24 has a U-shaped cross section along the shape of the rectangular ring-shaped magnetic core 22 in the drawing. A printed wiring pattern 25 is formed on the surface of the printed wiring board 21 opposite to the surface on which the magnetic core 22 is provided, and one end and the other end of adjacent jumper wires 23 are sequentially connected by the wiring pattern 25, that is, printing is performed. A plurality of printed wiring patterns 25 are formed in parallel with each other diagonally opposite to the jumper wire 23 via the wiring board 21 and the magnetic core, and one end of each wiring pattern 25 and one end of the adjacent one of the jumper wires 23 are formed. Further, the other end of the wiring pattern 25 and the other end of the adjacent one of the jumper wires 23 are respectively soldered and connected by the solder 30. In this way, the jumper wire 23 and the wiring pattern 25 constitute the primary coil 26 in which one side of the magnetic core 22 is wound.

Similarly, the jumper wire 27 and the printed wiring pattern 28 of the printed wiring board 21 form a secondary coil 29 on the side of the magnetic core 22 opposite to the side where the coil 26 is wound. The magnetic core 22 is formed by both the jumper wires 23 and 27.
Are fixedly held on the printed wiring board 21. 2 shows another embodiment of the present invention, in which parts corresponding to those in FIG. 1 are designated by the same reference numerals. In this example, a flat cable 31 is provided so as to straddle one side of the magnetic core 22, and core wires 31a at both ends of the flat cable 31 are exposed and inserted into the holes formed in the wiring board 21, respectively, and vice versa. Is connected by soldering to the wiring pattern 25 on the surface of the magnetic core 22 to form the primary coil 26. Similarly, the flat cable 32 straddles one side of the magnetic core 22 opposite to the flat cable 31. This is the case where the core wires 32a at both ends thereof are exposed and inserted through the holes provided in the wiring board 21 and connected to the wiring patterns 28 to form the secondary coil 29. In this case, the insulating layer 24 of FIG. 1 is omitted.

As shown in FIG. 3A, the primary coil 26 is
For example, as shown in FIG. 1A, the jumper wire 23 and the wiring pattern 2
5 and the secondary coil may be one in which the coil 34 is wound around the bobbin 33 inserted into one side of the magnetic core 22. In this case, as shown in the figure, the bobbin 33 and the coil 34 are arranged so that the wiring board 2 and the coil 34 do not get in the way.
The opening 35 may be formed in a part of 1.

The magnetic core 22 does not have a ring shape, but a rod-shaped magnetic core 36 is arranged on the wiring board 21 as shown in FIG. Alternatively, the secondary coil 29 formed by the jumper wire 27 and the pattern 28 may be formed on the magnetic core 36 side by side. Also in this case, the coil may be configured by the flat cable and the wiring pattern instead of the jumper wire. FIG. 3C
As shown in FIG. 3, a H-shaped magnetic core 37 is used, and the primary coil 2 is formed on the central connecting portion 37a by a jumper wire and a pattern.
6. The secondary coil 29 may be similarly formed.

[0009]

As described above, according to the present invention, the magnetic core is arranged on the printed wiring board 21, and a jumper wire, a flat cable or the like is provided across the magnetic core, and the magnetic core is provided on the printed wiring board. Since the coil is formed by inserting both ends and shifting the inserted and protruding ends one by one, and connecting them by a wiring pattern, for example, when a jumper wire is used, the coil is sequentially connected to the wiring board 21. It can be mechanically inserted, and the magnetic core can be held on the wiring board by the wiring board and jumper wires or flat cables. In many cases, the high-frequency coil has a relatively small number of turns, and it is easy to configure in this way. Rather, the manufacturing can be performed automatically as compared with the conventional one shown in FIG. 4, and the number of man-hours is small, and the manufacturing can be performed inexpensively.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, and B is a sectional view taken along the line AA.

FIG. 2A is a plan view showing another embodiment according to the present invention,
B is the BB sectional view taken on the line.

FIG. 3A is a sectional view corresponding to FIG. 1B or FIG. 2B showing still another embodiment of the present invention, and B and C are plan views showing still another embodiment of the present invention.

FIG. 4 is a front view and B is a side view showing a conventional high frequency transformer of this type.

Claims (1)

[Claims] 1. A printed wiring board, a magnetic core arranged on the printed wiring board, a plurality of conductive wires, both ends of which are inserted into the holes of the wiring board across the magnetic core, and the printed wiring board. And a wiring pattern formed on the surface opposite to the surface on which the magnetic core is arranged and printed, and sequentially connecting one end and the other end of the adjacent ones of the conductive wires.