JPH02208907A - Inductance element and its manufacturing method - Google Patents

Abstract

PURPOSE:To contrive improvement in quality characteristics by a method wherein a comb terminal and the junction part of the lead wire of a coil and the comb terminal are covered with insulative resin, and the entire body, excluding the tip of the pectinated terminal is sealed and molded with Mn-Zn ferrite powder containing resin. CONSTITUTION:The lead wire 11 of a coil 10, wound around a ferrite core 9, is connected to a comb terminal 7, a covering of insulative resin 12 is formed on the comb terminal 7 containing the lead wire 11 and the connected part, and the entire body is sealed and molded with Mn-Zn ferrite powder containing resin 13. When a sealing and molding operation is conducted using the Mn-Zn ferrite powder containing resin as above-mentioned, a Qmax value can be improved by covering the comb terminal and the junction part of the lead wire 11 of the coil 10 and the comb terminal 7.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an inductance element used in various electronic devices and a method for manufacturing the same.

2. Description of the Related Art The structure of a conventional magnetically shielded wire-wound inductance element is shown in FIG.

In FIG. 2, 1 is a drum-shaped ferrite core, a coil 2 is wound around this ferrite core 1, a comb terminal 3 is bonded to the bottom surface of this ferrite core 1 with adhesive 4, and this The lead wire 6 of the coil 2 is connected to the comb terminal 3, and the comb terminal 3 is molded with a resin 6 containing Mn-Zn ferrite powder so that only the tip of the comb terminal 3 is exposed, and the comb terminal 3 protrudes from the resin 6. It was constructed by bending along the side surface of the resin 6.

In this way, in the shield type chip inductor, the current product is made of insulating resin 6 containing Ni-Zn ferrite.
Sealing molding is performed using In order to further improve the characteristics, Mn-Zn ferrite powder with high magnetic permeability was used.

However, the Mn--Zn ferrite sintered body has a low electrical resistance, which causes eddy current loss, and the eddy current loss increases in a high frequency band, making it difficult to use.

As a countermeasure, Mn-Zn ferrite powder is mixed with insulating resin and kneaded, and the surface of the powder is covered with insulating resin to increase electrical resistance, thereby suppressing the increase in eddy current loss and allowing use in high frequency bands. Now you can.

Problems to be Solved by the Invention However, when sealing is performed with an insulating resin using the above-mentioned Mn-Zn ferrite powder with high magnetic permeability, N
There is a problem that the Q characteristic is lower than that when i-Zn ferrite powder is used, and the Q characteristic must be improved.

Means for Solving the Problems In order to solve the above-mentioned problems, the inductance element of the present invention has a structure in which the comb terminal in the element and the joint between the coil lead wire and the comb terminal are coated with an insulating resin. It is something.

Effects As described above, the Q characteristic can be improved by using the structure of the present invention in which the comb wire portion and the joint portion between the coil lead wire and the comb terminal are insulated and coated with an insulating resin. The main reason for this seems to be that the comb terminal and the joint between the coil terminal and the comb terminal no longer come into direct contact with the Mn--Zn ferrite powder.

EXAMPLES Hereinafter, the present invention will be explained in detail using specific examples.

A detailed explanation will be given using a cross-sectional view of an example of a wire-wound inductance element shown in FIG.

In FIG. 1, a drum-shaped ferrite core 9 is bonded to the comb terminal 7 via an adhesive 8, and a lead wire 11 of a coil 10 wound around the ferrite core 9 is connected to the comb terminal 7. The com terminal 7 including the connection part with the lead wire 11 is coated with an insulating resin 12, and the whole is made of M
An exterior is formed of a resin 13 containing n-Zn ferrite powder, and the tip of the comb terminal 7 that protrudes outside of the resin 13 containing n-Zn ferrite powder and is not covered with the insulating resin 12 is folded along the exterior. It is bent to form a chip-type inductance element.

The method for manufacturing this inductance element is to apply adhesive 8 to comb terminal 7, place Ni-Zn ferrite core 9 on top of it, solidify adhesive 8, and solidify ferrite core 9 and comb terminal 7. Then, an insulated copper wire with a diameter of 30 μm is wound with 42 turns around the ferrite core 9 to form the coil 1.
The lead wires 11 at both ends of the wire were connected to the com terminal 7 by soldering, and the joints between the com terminal 7 and the lead wire 11 of the coil 10 and the com terminal 7 were insulated with insulating resin 12 (sample point 1). For comparison, we also created a coil in which the connecting part between the COM terminal 7 and the lead wire 11 of the coil 1Q was not insulated (Sample 52).
.

On the other hand, a calcined Mn-Zn ferrite ingot was crushed.

The powder is classified into powders with a particle size of 105 μm or less, mixed by 76% by weight in an epoxy resin as a sealing resin, and kneaded with a hot roll.
Formed into a tablet. Next, the coil 1o fixed to the above-mentioned com terminal 7 is installed in the mold, and the mold is heated to 170°C.
After raising the temperature to , a transfer molding machine was operated to perform sealing molding using the tablets of the epoxy resin 13 containing the Mn-Zn ferrite powder described above. After curing for a certain period of time, the sealed molded product was removed from the mold and
After assimilation treatment at ℃ for about 6 hours, the protruding part of the comb terminal 7 was bent and the length was 3.2M, the width was 1.6ffJ+, and the height was 1.1
Finished with my inductance element.

This insulates the inductance element that insulates the joint between the COM terminal 7 and the lead wire 11 of the coil 10 and the COM terminal 7, and the joint between the COM terminal 7 and the lead wire 11 of the coil 1Q and the COM terminal 7. It was possible to create an uncoated inductance element. For these two types of inductance elements, L and Q are measured using an L-C-R meter.
was measured.

The results are shown in Table-1.

(The following is a blank space) From the above results, the inductance element of the present invention shown in black 1 is as follows:
The com terminal 7 and the lead wire 11 of the coil 10 and the com terminal 7
Qw compared to A2 which does not have insulation coating on the joint part with
An improvement of 106 factors was observed in the ax value.

Effect of the invention As mentioned above, in the inductance element.

When performing sealing molding using an insulating resin containing Mn-Zn ferrite powder, Qma
The x value can be improved by 106% compared to the case where it is not covered, and a practical chip inductor element can be obtained. Furthermore, in contrast to the Ni-Zn ferrite powder that is currently mainly used in shield-type chip-type inductance elements, the present invention can use Mn-Zn ferrite powder that has even higher characteristics and is cheaper. It has great industrial significance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of an inductance element according to the present invention, and FIG. 2 is a sectional view showing the structure of a conventional magnetically shielded wire-wound inductance element. 7...Com terminal, 8...Adhesive, 9.
...Fenite Core, 10...Coil
11...Leader line. 12...Insulating resin, 13...Ni-
Zn-based fue. Resin containing light powder. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (2)

[Claims] (1) The comb terminal that connects the core around which the coil is wound and the joint between the coil lead wire and the comb terminal are covered with insulating resin, and the entire comb terminal except the tip is filled with Mn-Zn ferrite powder. Inductance element externally molded with resin. (2) After gluing a ferrite core to a comb terminal, winding the ferrite core to form a coil, and connecting the lead wire of the coil to the comb terminal, join the comb terminal and the lead wire of the coil to the comb terminal. 1. A method for manufacturing an inductance element, comprising covering a portion with an insulating resin, and then sealing and molding with an insulating resin containing Mn-Zn ferrite powder.