JPH01199416A - Inductance element - Google Patents

Abstract

PURPOSE:To obtain the wound type thin inductance element of small size equal to C and R chip parts by a method wherein a coil is formed by winding a copper wire around the winding groove of a square-shaped core, a heatproof plastic wire is wound and fixed on the coil, and a pair of electrodes, which is electrically connected to the lead part of the coil, are provided on the opposing end face of the square-shaped core. CONSTITUTION:A coil 2 is formed by winding a copper wire on the winding groove 5 of a square-shaped core 1, a heat-resisting plastic wire 3 is wound and fixed on the coil 2, and a pair of electrodes 4a and 4b, which are electrically connected to the lead part of the coil 2 respectively, are provided on the end face opposing to the end face having the above- mentioned winding groove 5. For example, a coil 2 is provided by winding a copper wire on the winding groove 5 provided on the end face of a square-shaped core 1 in the prescribed number of turns, and after winding a heatproof plastic wire 3 of polyester, polyimide and the like on the surface of which a thermosetting bonding agent was coated in advance, on the above-mentioned coil 2, the plastic wire 3 is adhered to the square-shaped core 1 and the coil 2 by heating. Then, the pair of electrodes 4a and 4b, which are electrically connected to the lead part of the coil 2, are provided in such a manner that the one end of the metal plate bent in L-shape is fixed to the bottom face of the square-shaped core 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to inductance elements used in electronic circuits in various fields such as video and television, and in particular to high-density packaging 1 in recent years.
The present invention provides a small and thin inductance element suitable for surface mounting.

2. Description of the Related Art A conventional inductance element having a structure as shown in FIG. 4 is well known. In FIG. 4, 41 is a drum core, and generally a sintered body of ML-zn ferrite is used. 42 is a coil, and the drum core 41 is wound with a copper wire having a diameter of 30 to 60 μm. The drum core 41 provided with the coil 42 is fixed to metal plate terminals 44fL and 44b, and the lead portion (not shown) of the coil 42 is connected to the metal plate terminal 44! L and 44b, respectively.

43 is resin, and the drum core 41. A portion of the coil 42 and metal plate terminals 44&, 44b are integrally molded.

The conventional inductance element, which has a configuration that exceeds the problem to be solved by the invention, has features such as a single winding, so it has a high Q and can obtain a large inductance, and can be mass-produced at a relatively low cost, so it is suitable for surface mounting. It has become the mainstream inductance element for applications.

However, due to constraints in manufacturing the drum core, which is mainly made of sintered ferrite, it has been difficult to make the drum core smaller and thinner than C and H chip parts.

The present invention eliminates the drawbacks of the conventional inductance element and provides a single-winding inductance element that is small and thin and comparable to C and H chip components.

Means for Solving the Problems In order to solve the problems above, the inductance element of the present invention is made by winding a copper wire in the winding groove of a square core to form a coil, and then winding a heat-resistant plastic wire on top of the coil. A pair of electrodes each electrically connected to the lead portion of the coil is provided on opposing end surfaces of the square core.

The present invention, which has the above means, does not use molding resin and uses the rectangular core itself as the main body of the inductance element, thereby making it compact without reducing the core size.

By making the coil thinner and wrapping and fixing a heat-resistant plastic wire over the coil, the coil installed in the single-turn groove is protected from the heat received during mounting of inductance elements such as solder dips and (infrared) reflow. We are working to improve reliability.

Example The present invention will be explained in detail below based on examples.

FIG. 1 is a perspective view showing an embodiment of the inductance element of the present invention, and FIG. 2 is a sectional view taken along the line 5' of FIG. In both figures.

1 is a rectangular core, and a coil 2 is provided by winding a copper wire a predetermined number of times in a winding groove 6 provided on the end face of the core. 3 is a heat-resistant plastic wire made of polyester, polyimide, etc. that is further wound on top of the coil 2. The surface of the wire is coated with a thermosetting adhesive in advance, and after being wound around the 9-turn groove 6, it is heated. and fix it to the square core 1 and coil 2. 4a and 4b are a pair of electrodes electrically connected to the lead portion (not shown) of the coil 2, and in this embodiment, one end of a metal plate bent into an L shape is fixed to the lower surface of the square core 1. It was set up as follows.

In this embodiment having the above configuration, by using the rectangular core 1 itself as the main body of the inductance element without using molding resin, it is possible to significantly reduce the size and thickness compared to the conventional inductance element.

To give an example of a specific value, the required wall thickness of the molding resin is generally 0.3W or more, and if it is less than this, unfilling will occur. Therefore, simply by not using resin molding, the thickness of the inductance element can be reduced by 0.69 or more. In this example, 3,2 (#X 1.e (TSX 1,1 (t) II
II' dimensions have been achieved. The minimum dimensions of a conventional wound wire inductance element are 3.2 (j7) x 2,5
(w)X 2.2 (t)s+s3, and the thickness is 1 bar
A small and thin inductance element with a volume of W or less can be realized.

Furthermore, by winding and fixing the heat-resistant plastic wire 3 over the coil 2, the heat applied to the coil 2 is reduced and accidents such as layer shorts are prevented.

In addition, soldering prevents flux from adhering to the coil 2, eliminates characteristic deterioration such as a decrease in self-resonance frequency, and greatly improves reliability.

Note that if a sintered ferrite body is used as the square core 1, an inductance element with a large inductance and Q can be realized. Furthermore, when non-magnetic ceramics such as alumina are used, the inductance is small but the frequency characteristics are improved, making it possible to realize an inductance element for high-frequency circuits.

FIG. 3 shows a sectional view of another embodiment of the invention.

The constituent elements of this embodiment are the same as those of the previous embodiment, so their explanation will be omitted.

The feature of this embodiment is that the square core 1 is made of resin containing magnetic material.
1, the terminals 4a and 4b can be embedded in the rectangular core 1 as shown in the figure, and the two can be firmly fixed. Also, the terminals aa and 4b are made of metal plates,
A plurality of these are connected to form a hoop terminal, and the rectangular core 1 can be fixed to the hoop terminal continuously and at high speed by molding, thereby reducing the number of man-hours and material costs.

As the magnetic substance contained in the resin, ferrite powder, amorphous powder, etc. can be used.

Further, by using a mixture of two or more types of magnetic materials, for example, by mixing ferrite powder and amorphous powder at a predetermined ratio, the desired frequency characteristics can be easily achieved.

Effects of the Invention As stated above, the present invention provides a small and thin inductance element that is wound and has a thickness smaller than that of conventional inductance elements in terms of A1 volume, and is suitable for high-density mounting on circuit boards. This will greatly contribute to the miniaturization and thinning of electronic devices.

[Brief explanation of the drawing]

1 and 2 are a perspective view and a sectional view showing one embodiment of the inductance element of the present invention, FIG. 3 is a sectional view showing another embodiment, and FIG. 4 is a sectional view showing a conventional inductance element. It is. 1... Square core, 2... Coil, 3.
...Heat-resistant plastic wire, 4a, 4b...
...Terminal. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 4 uj IPI child

Claims (3)

[Claims] (1) Copper wire is wound around the winding groove of a rectangular core to form a coil, and a heat-resistant plastic wire is further wound and fixed on top of the coil, and the coil is attached to the facing surface of the end face having the winding groove. An inductance element that has a pair of electrodes each electrically connected to a lead part. (2) The inductance element according to claim 1, wherein the square core is made of ferrite or non-magnetic ceramic. (3) Claim 1 in which the square core is made of a resin containing a magnetic substance.
The inductance element described.