JPS603561Y2 - high frequency inductor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a chip-type high-frequency inductor made by winding a coil around a small rod-shaped magnetic core bobbin, and aims to provide a high-frequency inductor with a constant external shape and no lead breakage.

Conventionally, this type of chip-type high-frequency inductor has been constructed by placing conductive caps 2 on both ends of a rod-shaped magnetic core bobbin 1, and placing a coil 7 between the caps 2 and a collar 5 provided on the bobbin, as shown in FIG. A structure in which the coil is wound and the lead 7' of the coil is connected and fixed to the outer periphery of the cap 2 with solder 8 is well known.

However, in a high-frequency inductor with this structure, since the coil lead 7' is soldered to the outer periphery of the cap 2, a raised part of the solder 8 is formed on the outer periphery of the cap, and the external shape and dimensions of the high-frequency inductor are not constant. Automatic parts insertion machines had the drawback of being difficult to handle.

Furthermore, when the cap of a high-frequency inductor is placed on a printed circuit board and soldered to the circuit pattern on the board, the connecting solder between the circuit pattern and the cap and the solder 8 for connecting the lead of the coil are easily fused, and the solder 8 There were many accidents where the lead 7' came off from the cap 2 due to melting.

The present invention is intended to improve the above-mentioned drawbacks, and examples thereof will be described below.

FIG. 2 shows an embodiment of the present invention, in which a coil 7 is wound around the middle of a rod-shaped magnetic core bobbin 1, and conductive metal caps 3 are inserted into both ends of the bobbin 1. The inner diameter of the cap is made larger than the outer diameter of the bobbin 1, and the insertion open end 3' of the cap is constricted into a tapered shape, and the lead 7' of the coil 7 is connected to the constricted part with solder 8, etc., and the constricted part is connected. This high frequency inductor is characterized by a structure in which the outer periphery of the portion and the coil 7 are covered with an insulating synthetic resin 9, and the connecting solder 8 does not protrude beyond the outer periphery of the portion of the cap that cannot be compressed.

Note that 5 is a brim formed on the bobbin 1 between the caps 3, and although this brim is not essential, the coil 7
is stably fixed to bobbin 1.

The collar 5, like the coil 7, is covered with the synthetic resin 9.

Further, it is preferable that the synthetic resin 9 has the same outer diameter or shape as the outer diameter of the cap 3.

In a high-frequency inductor having such a structure, the mutually opposing open ends 3' of the caps 3 inserted into both ends of the bobbin 1 are tapered, and the tapered portions form a recess to which the leads 7' are connected by soldering. Therefore, even if the connecting solder 8 swells up, it does not protrude beyond the outer diameter of the cap 3, and the outer shape and dimensions are constant, the appearance is good, and it can be stored in the magazine of an automatic inserter for printed circuit boards without any problem. Because
Suitable for automated integration into circuit boards.

Also, when soldering to a circuit pattern on a printed circuit board, the connection solder between the circuit pattern and the cap 3 is located far away from the connection solder 8 between the coil lead 7' and the cap 3, so it is difficult to fuse. Accidents where 7' comes off will be improved.

The shapes and dimensions of the rod-shaped magnetic core bobbin 1, conductive metal cap 3, and coil 7 used in the present invention may be arbitrarily determined upon implementation.

However, for the bobbin 1, if a flat part 1' is formed on the outer periphery of the end of the round bar-shaped magnetic core bobbin 1 as shown in FIG. 3A, the cap 3 inserted into the bobbin and closing the open end 3' will not rotate. Furthermore, the recess is also formed with a flat portion, making it easier to solder the coil lead 7'.

It also shows a modification of the cap 3 shown in FIG.
A longitudinal slit 4 is formed from the end of the cap to provide a section 4', making it easier to close the section 4' at the open end 3' of the cap.

Note that the insulating synthetic resin 9 is not limited to this, but if magnetic powder is mixed into the synthetic resin or other magnetic material is used, the inductance and Q of the coil can be prevented from decreasing, and the overall A wide variety of common insulating materials can be used to increase mechanical strength.

[Brief explanation of the drawing]

FIG. 1: A cross-sectional view showing a conventional high-frequency inductor. FIG. 2 is a sectional view showing one embodiment of the high frequency inductor of the present invention. FIG. 3 is a perspective view showing another embodiment A of the bobbin and another embodiment B of the cap used in the present invention. 1: rod-shaped magnetic core bobbin, 2, 3: cap, 5 nippers, 7: coil.

Claims (1)

[Scope of utility model registration request] In a high-frequency inductor in which a coil is wound around the middle of a rod-shaped magnetic core bobbin and conductive caps are inserted at both ends of the bobbin, the inner diameter of the cap is made larger than the outer diameter of the bobbin.
A high-frequency inductor characterized in that the insertion open end of the cap is tapered and constricted, a coil lead is connected to the constricted part, and the connecting part does not protrude at least beyond the outer periphery of the cap.