JPH0631112U - Chip coil - Google Patents

Abstract

(57) [Abstract] [Purpose] To develop a product that can reduce the production cost by omitting the lead wire attaching step in the production of wire-wound chip coils. [Constitution] If an electrode is provided on the outer end face of the core flange of the chip core in order to omit the lead wire, the coil characteristic value (Q) will be lowered, so an insulator layer such as glass should be provided between the outer end face of the core and the electrode face. By sandwiching the coil winding and connecting the ends of the coil to the electrodes, a chip coil having a coil characteristic value (Q) comparable to the conventional product was obtained. Since the chip coil can omit the lead wire attaching step, the production cost can be greatly reduced as compared with the conventional product.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a wire-wound chip coil in which an external lead wire is omitted. The present invention relates to a wire-wound chip coil having a structure in which lead wires are omitted by connecting ends.

[0002]

[Prior art]

 The conventional method of connecting the winding end and the lead wire in the winding type chip coil is as shown in FIGS. 3 and 4, for example. That is, in the example shown in FIG. 3, the drum core flange portion 2 is processed as shown by the dotted line, the lead wire 7 is pressed and attached, and the end of the lead wire 6 of the chip coil 11 is connected thereto. On the other hand, in the example shown in FIG. 4, the drum core flange portion 2 is processed as shown by the dotted line, and the lead wire 7 is attached thereto by rotting or the like. In the conventional wire-wound chip coil having the structure in which the lead wire is attached to the drum core, the processing cost is high and the production cost is inevitably increased in any case, and it is difficult to provide an inexpensive chip coil.

Therefore, as shown in FIG. 5, if a plate-shaped electrode 5 is directly attached to the outer end surface of the flange portion 2 of the drum core and the coil winding end portion is connected to the electrode, it is used in a conventional product. It was thought that the projecting rod-shaped lead wire could be omitted, thus reducing the production cost.

[0004]

[Problems to be solved by the device]

 However, as described above, when the plate-shaped electrode 5 is directly attached to the outer end surface of the flange portion 2 of the drum core, the magnetic field lines 8 are generated in the direction shown in FIG. , It penetrates the collar portion 2 of the drum core and crosses the electrode 5 mounted on the collar portion 2, and the electromagnetic induction action acts to generate an eddy current in the electrode 5, and the coil characteristic value (Q) However, there was a problem in that

Therefore, an object of the present invention is to provide a chip coil which can omit the attachment of the lead wire and can suppress the decrease of the coil characteristic value (Q) to the minimum.

[0006]

[Means for Solving the Problems]

 If a flat plate-shaped electrode is attached to the outer end surface of the brim of the chip coil with an insulator layer sandwiched between them, and the coil winding end is connected to the electrode, a protruding rod-shaped lead wire as used in conventional products Can be omitted and the production cost can be saved.

The present inventor has conducted earnest research to find a method for mounting an electrode according to the above-mentioned idea without causing such a decrease in the coil characteristic value (Q). If an electrode is attached with an insulator layer sandwiched between them and the end of the coil winding is connected to this electrode, the coil characteristic value (Q) can be suppressed from decreasing and the electrode can be integrated with the chip coil. It was possible to provide the present invention.

The present invention will be described in more detail with reference to FIGS. 1 and 2A and 2B. FIG. 1 is an elevation view of a drum core 1 which constitutes a chip coil of the present invention. Reference numeral 2 in the figure denotes a collar portion of the core, which is integrally provided at both ends of the coil winding portion 3 adjacent to the winding portion. Further, 4 is a glass insulator layer formed by printing a glass paste and then firing it. Reference numeral 5 is an electrode forming the outermost layer of the chip coil. Furthermore, FIG. 2 is a diagram showing the appropriateness of the position and shape of the electrode to be provided on the outer end surface of the flange portion 2 of the drum core shown in FIG. 1, and in the shaded portion of FIG. The shaded portion in (b) shows the shape of the electrode to be formed correspondingly. The insulator layer 4 does not necessarily have to be provided on the entire outer end surface of the core flange portion 2 and may be formed in a portion sandwiched between the electrode 5 and the core flange portion 2. A coil element in which a conductor wire 6 is wound around a core winding portion 3 which is a central portion of a drum core having such a structure to form a winding portion, and the end of the conductor wire 6 is connected to the electrode 5 is a chip according to the present invention. It is a coil. This is because the coil characteristic value (Q) is almost comparable to that of the conventional product with a lead wire, and as a result of the effect of omitting the lead wire, it is possible to provide a cheaper coil chip than the conventional product.

[0009]

[Action]

 The operation of the chip coil according to the present invention will be described with reference to FIG.

In FIG. 1, the insulating layer provided between the outer end surface of the flange portion 2 of the drum core and the flat plate-shaped electrode 5 has a low magnetic permeability, and is generated when a current flows through the coil winding. It becomes difficult for the magnetic force lines to pass through the glass insulator, and the magnetic field lines pass toward the peripheral surface of the flange portion 2 of the drum core. Therefore, the magnetic lines of force passing through the plate-shaped electrode 5 are reduced, and the generation of eddy current is suppressed.

Therefore, the insulator layer may be formed only on the outer end surface of the flange portion 2 of the drum core where the electrodes are formed.

[0012]

Example 1 A glass paste for crossover used for hybrid ICs was printed to a thickness of 30 μm on the outer end surface (A side) of one brim of the green core in the conventional product production process, and dried at 150 ° C for 10 minutes. did. Next, the same treatment was performed on the flange surface (B surface) of the opposite core. A 10 μm thick silver-palladium paste was printed on the A side of the obtained green core, dried at 150 ° C for 10 minutes, and the same treatment was applied to the B side again. Were fired at a temperature at which they could be fired simultaneously to obtain a sintered body core. Finally, a conducting wire was wound around the coil winding portion of the core and the winding ends were connected to the electrodes to obtain a chip according to the present invention.

As a result of measuring the coil characteristic value (Q) of the chip coil, assuming that Q is 100 in the case of a chip core close to a conventional product in which no electrode is provided in the core, 39 is obtained when the electrode is directly attached to the core, It was 70 when a glass layer was provided between the electrode and the core brim according to the present invention. In other words, the chip coil according to the present invention was a product that was comparable to the conventional product.

[0014]

Second Embodiment Some application examples of the present invention will be described below. (1) FIG. 6 shows an example of the chip coil of the present invention in which electrode contacts are attached to one side. (A) is an elevation view of the chip coil, and (b) is a view showing the shape of the electrode. (2) FIG. 7 shows an example of the chip coil of the present invention in which the electrode contacts are attached to the lower side of the core collar. Since the electrode does not cross the magnetic field lines, the size of the electrode may be 1/6 to 1/4 of the entire circumference of the flange surface. (3) FIG. 8 is a modification of (2). If the ends of the winding are mounted in this way, rolling can be prevented when mounted on the land of the board.

[0015]

[Effect of device]

 According to the present invention, an electrode is provided on the outer end surface of the drum core flange portion that constitutes the chip core with an insulating layer sandwiched between them, and the coil winding terminal is connected to the electrode. Since it is possible to suppress a significant decrease in Q), it is possible to omit the step of attaching the lead wire as in the conventional product, and it is possible to significantly reduce the production cost.

[Brief description of drawings]

FIG. 1 is a schematic elevational view for explaining the structure of a chip coil according to the present invention.

FIG. 2A is a diagram showing a position (shaded portion) where electrode formation on the outer end face of the core flange should be avoided, and FIG. 2B is a diagram showing a preferable electrode shape (shaded portion) in this case. Is.

FIG. 3 is a schematic elevational view for explaining the structure of a conventional chip coil with a lead wire, particularly how to attach the lead wire.

FIG. 4 is a schematic elevational view for explaining the structure of another example of the conventional chip coil with leads.

FIG. 5 is an explanatory diagram of the action of magnetic lines of force on the characteristic value of the chip coil in which the electrode is directly attached to the outer end surface of the core flange portion.

FIG. 6 is a view showing an example of a chip coil of the present invention in which electrodes are provided on one side of a core collar.

FIG. 7 is a view showing an example of a chip coil of the present invention in which electrodes are provided on both sides of a core collar.

8 is a perspective view for clearly showing how to attach the coil chip shown in FIG. 7. FIG.

[Explanation of symbols]

 1 Drum Core 2 Collar 3 Coil Winding Part 4 Glass Insulator Layer 5 Electrode 6 Conductor 7 Lead Wire 8 Magnetic Field Line 9 Land 10 Winding Part 11 Chip Coil

Claims (1)

[Scope of utility model registration request] 1. A chip coil having a conductor wound around a coil winding portion of a drum core, wherein an insulator layer is formed on an outer end surface of a core flange portion, and an external terminal electrode is formed on the insulator layer. A chip coil, wherein the external terminal electrode is connected to an end of the conductor.