JPH03261114A - Chip inductor - Google Patents

Abstract

PURPOSE:To shorten characteristic tolerance and to improve reliability without failures such as disconnection by cutting coil foil plating which coats the full periphery of a cylindrical insulator so as to connect to a coil form into a coil and by electrically connect terminals to coil foil plating. CONSTITUTION:The full periphery of a cylindrical insulator 1 formed from an insulative magnetic substance such as ferrite core or an insulative nonmagnetic substance such as ceramic and plastic is coated with copper foil plating 2. The copper foil plating is cut in the side face of the cylindrical insulator 1 so as to connect to a coil form into a coil 3, and terminals 6 are inserted into both end holes 5 of the cylindrical insulator 1 to electrically connect with the copper foil plating 2; further, the whole is molded with a molding material so that one end of each terminal 6 may be exposed. This design can finely adjust electric characteristics by dimensional adjustment of the cutting work of the copper foil plating 2 to shorten characteristic tolerance with the result that reliability can be improved with no line-processing problems such as disconnection.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a chip inductor used in various electronic devices.

BACKGROUND OF THE INVENTION In recent years, various electronic devices have become more sophisticated and smaller, and high-quality chip inductors are widely sought after.

Conventionally, this type of chip inductor has generally had a laminated structure in which plated coil plates are stacked, or one shown in FIG. 3 or 4. Below, Figures 3 and 4
The configuration will be explained with reference to figures.

As shown in the figure, a coil 1 wound around a drum-shaped core 10
1 lead wire 12 is connected to the terminal 13 by soldering, and the whole is molded with molding material 14 so that the end of the terminal 13 is exposed.
It had a bottom shape.

Problems to be Solved by the Invention Since such conventional chip inductors with a laminated structure are made of stacked thin plates, there are problems in terms of characteristics such as a decrease in inductance with a small current and a low Q. With the winding structure as shown in Figures 3 and 4, the winding variation is large and the number of turns cannot be adjusted finely, making it difficult to reduce the characteristic tolerance.Furthermore, since the wire is wound with thin wire, there is a possibility of wire breakage or contact with the terminal. Tunnel soldering or baking during connection has problems such as thinning.

The present invention is intended to solve the above-mentioned problems, and aims to improve reliability by improving electrical characteristics and eliminating disconnections and poor solder connections.

Means for Solving the Problems In order to achieve the above object, the present invention uses a cylindrical insulator formed of an insulating magnetic material such as a ferrite core or an insulating non-magnetic material such as ceramic or plastic. W4 foil plating is applied to the entire circumference, and the sides of this cylindrical insulator are li! Cut the foil plating so that it connects into a coil shape, insert the terminals into the holes at both ends of the cylindrical insulator, electrically connect the terminals and the IR-finished plating, and then make one end of the terminals at both ends stick out. The solution to this problem was to mold the entire product using molding material.

Effects The present invention uses the above-mentioned problem-solving means to finely adjust the electrical characteristics and reduce the characteristic tolerance by adjusting the dimensions of the cutting process of W4 foil plating, and has a structure in which a coil is wound in a space winding around a cylindrical insulator. Therefore, stray capacitance is small and Q can be increased. Furthermore, when terminals inserted at both ends of the cylindrical insulator are connected by solder, problems such as wire breakage are eliminated because the terminals are formed in wide areas other than the insertion holes that are in contact with the terminals.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 and 2.

As shown in the figure, the cylindrical insulator 1 is made of an insulating magnetic material such as a ferrite core, or an insulating non-magnetic material such as ceramic or plastic, and the entire circumference of the cylindrical insulator 1 is Copper foil plating 2 is applied, and then the side surfaces are cut to form a coil 3 to form a coil body 4. A protrusion 7 of a terminal 6 is inserted into a hole 5 provided at the center of both ends of the cylindrical insulator 1, and is connected by solder to the copper foil plating 2 in contact with the terminal 6. With the coil body 4 and the terminal 6 electrically connected by solder, the outer periphery is molded with a molding material 9 such as resin so that the end 8 of the terminal 6 is exposed, and the terminal 6 is exposed from the molding material 9. The end portion 8 can be homed and used for surface mounting.

Effects of the Invention As is clear from the above embodiments, according to the present invention, the W4 foil plating on the side surface of the cylindrical insulator is cut into a coil shape, so that the pitch width and number of turns of the coil can be finely adjusted. can be set as desired, and characteristic tolerances can be reduced compared to conventional methods. Additionally, since the coil is space-wound, it has good high-frequency characteristics, and since thin wires are not used, there are no problems with wire processing such as wire breaks, and reliability can be improved.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a chip inductor according to an embodiment of the present invention, FIG. 2 is a perspective view of the same chip inductor as seen through the molding material, and FIG. 3 is a sectional view of an example of a conventional chip inductor. FIG. 4 is a sectional view of another example of the same chip inductor. l... Cylindrical insulator, 2... Ti4 foil plating, 3... Coil, 5... Hole, 6
...Terminal, 8... End, 9...
・Mold material.

Claims (1)

[Claims] A cylindrical insulator, a coil formed by cutting copper foil plating applied to the entire circumference of the cylindrical insulator so as to be connected in a coil shape, and protrusions inserted into holes provided at both ends of the cylindrical insulator. A chip inductor comprising a terminal electrically connected to the copper foil plating and a molding material covering the entire terminal so that the end of the terminal is exposed.