JP2002184634A - Method for forming inductor provided with on-piece core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inductor provided with a one-piece core with which problems, such as noise and gaps, can be solved. SOLUTION: This method for forming an inductor provided with a one-piece core includes at least a step (a) to provide an in-advance molded core base, that is provided with a groove and two core base openings; a step (b) to form two pins for the inductor by forming, such a flat coil in the groove of the core base, that is provided with a first end and a second end and stretching the first and second ends at a desired angle, for example, stretching or exposing them in parallel or at 90 degrees from the core base openings directed toward the outside; and a step (c) to form a one-piece core to cover the flat coil, by compressing a core powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an inductor and a method for forming the same, and more particularly, to a method for forming an inductor having a one-piece core.

[0002]

2. Description of the Related Art The core of a known inductor is generally formed by combining two cores, so that at a high frequency, a noise problem occurs due to an air gap of the core.
As shown in the cross-sectional view of the known inductor of FIG. 1, the known inductor has two E-shaped cores (the first core 2, respectively).
0 and a second core 21) and a coil 24.
As shown in the figure, an air gap 23 is provided between the center legs of the first core 20 and the second core 21.
Is changed under the influence of the magnetic force, and the first core 20 and the second core 21 jointly move and bend 2 indicated by a dotted line.
Yields 6. In particular, at high frequencies, movement and flexure 26 produce noise. Microscopically, there is an air gap in the two combined cores, that is, the problem of noise is an unavoidable problem for the two combined cores.

In FIG. 1, in addition to this, a first core 2
There is a gap 28 between the 0, the second core 21 and the coil 24, which occupies the volume of the inductor, but has no advantage in increasing the inductor value.

[0004]

Therefore, there is a need for a way to solve the noise and clearance problems.

[0005]

SUMMARY OF THE INVENTION The present invention discloses a method of forming an inductor having a one-piece core, providing at least (a) a preformed core base having a groove and two core base openings. And (b) forming a flat coil in the groove of the core base, wherein the flat coil has a first end and a second end, and an extending direction of the first end and the second end is an arbitrary angle. E.g., parallel or 90 degrees, the first end and the second end extending or exposing outwardly from the core base opening to form two pins of the inductor; and (c) core powder. Forming a one-piece core for covering the flat coil by compacting the flat coil.

[0006] The step of forming a one-piece core includes (d)
Filling a core powder into the grooves of the core base,
(E) compacting the core powder. Thereafter, a heat treatment process is performed on the inductor to remove the binder, and the core powder is hardened to release the stress remaining during the compression process.

The present invention provides a method for forming an inductor with a one-piece core. In addition to eliminating noise, the method of the present invention has a higher inductor value in the same volume because the inductor formed by the method of the present invention has no gap between the core and the coil in the inductor of the present invention. Is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In order to further clarify the above-mentioned objects, features and advantages of the present invention, preferred embodiments of the present invention will be described below with reference to the drawings.

The method of the present invention, as shown in FIG.
First, step 50 is performed. Groove 2 as shown in FIG.
A core base 200 comprising 10 and two core base openings 220 is provided. The external appearance of the core base 200 is a rectangular box shape, and has a bottom surface, four side walls, and a groove 210 that can be stored. In this embodiment, the material of the core base 200 is iron or a silicon alloy.

Referring to FIGS. 2 and 3, a step 60 is subsequently performed. The flat coil 300 shown in FIG. 3 is formed in the groove 210 of the core base 200. The flat coil 300 has a first end 310 and a second end 320 and extends or is exposed outward from the core base opening 220 to form two pins of the inductor. This flat coil 300
Is adapted to the groove 210 so that the flat coil 300 can fit into the groove 210.

It should be noted that since the flat coil 300 is not wound on the surface of the core but is formed in the groove 210 of the core base 200, as can be seen here, the flat coil 300 is manufactured first, It can be combined with the base 200. Alternatively, the coil 300 and the core base 200 can be manufactured at the same time, and it is not necessary to wait for the core to be formed before winding the coil, thereby shortening the manufacturing time.

As shown in FIG. 3, a flat coil 300
Is formed by winding a thin flake wire uniformly covered with an insulating layer at least once by a parallel layer tatami mat method. The flake conductor is a flat strip-shaped flake, the cross section of which is a rectangle having a width (for example, 10 times) larger than the height (thickness) and having an upper surface and a lower surface. The surface is substantially adhered to the lower surface. Thereby, the gaps in the tatami mats are reduced or minimized to a minimum. In addition, when the thickness of the thin wire is about t and the number of turns is N, the height (thickness) of the flat coil 300 is about tN. In a preferred embodiment, the thickness and width of the flake conductor are 0.24 mm and 2.4 mm, respectively. However, the thickness and width of the thin conductor are not limited, and may be changed as needed.

As shown in FIGS. 2 and 3, a subsequent step 70 forms a one-piece core enclosing the flat coil 300 by powder compaction, and the step 70 includes the steps 73 and 7.
5 and 77. Step 73 fills a groove 210 of the core base 200 with a core powder 500 (indicated by a dotted line), the core powder including a binder and a material generally forming a core, such as iron, nickel, and the like. It is a mixture of silicon. Step 75 is core powder 500
Is pressed with a press machine, and core powder 50 is pressed.
Make 0 more tight. Thus, the gap inside the inductor 100 is greatly reduced, and more core powder enters the unit volume of the inductor 100. Step 77 performs a heat treatment step on the inductor 100, at least
(1) Remove the binder. (2) The core powder 500 is cured. (3) The purpose is to release the stress remaining during the above-mentioned compacting step. The heat treatment temperature is about 2 degrees Celsius
A suitable temperature is between 00 ° C and 400 ° C, 350 ° C. The heat treatment time is 2 hours to 4 hours, and 3 hours is appropriate.

It should be noted that the inductor 1 of the present invention
Since the pins of 00 are not needle-shaped, the inductor 100 can be mounted on a circuit board by surface mounting technology (SMT), and there is no need to insert it by an artificial method.

Clearly, the area of the inductor 100 of the present invention is smaller than known inductors of the same inductor value,
Since the inductor of the present invention does not form a coil by a known winding method, for example, the cross section of the coil 300 of the present invention is not circular but flat.

As described above, the core of the inductor according to the present invention is of a one-piece type, which can solve the problem of noise caused by the gap between the two-part cores of the known art.

In another preferred embodiment, the inductor value is 0.8 to 2.0 microhenry (μH), the maximum load current is 22 amps and the DC resistance is 2.5 to 4.3 ohms.
The thickness, length and width of the inductor of the present invention are each about 4
Mm, 12 mm, 12 mm.

Although the preferred embodiments of the present invention have been disclosed above, they are not intended to limit the invention in any way, and any person skilled in the art will be aware of this without departing from the spirit and scope of the invention. Thus, various variations and colors can be added, and the protection scope of the present invention is based on the contents specified in the claims.

[0019]

According to the present invention, the problem of noise caused by a gap between two-part cores of the prior art is solved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a known inductor.

FIG. 2 shows a process of the present invention.

FIG. 3 shows an inductor, a core, and a flat coil of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 inductor 200 core base 210 groove 220 core base opening 300 flat coil 310 first end 320 second end 500 core powder

Claims (6)

[Claims] 1. A method of forming an inductor comprising a one-piece core, comprising: (a) providing a preformed core base comprising at least a groove and two core base openings; and (b) the core base. Forming a flat coil in the groove of
The flat coil has a first end and a second end, and the extending directions of the first end and the second end are parallel, and the first end and the second end extend outward from the core base opening or Exposure,
Forming the two pins of the inductor; and (c) forming a one-piece core enclosing the flat coil by compacting the core powder. Method. 2. The method according to claim 1, wherein the step (c) further comprises: (d) filling a groove of the core base with the core powder; and (e) compacting the core powder. The method of claim 1. 3. The method according to claim 2, further comprising a heat treatment step after the step (e). 4. The temperature of the heat treatment step is about 200 to 100 degrees Celsius.
4. The method according to claim 3, wherein the temperature is 400C. 5. The method of claim 3, wherein the duration of the heat treatment step is about 2-4 hours. 6. The flat coil is formed by winding a thin wire at least once in a parallel-layered tatami mat system, the cross section of the thin wire is rectangular, having an upper surface and a lower surface, and after winding the thin wire, The method of claim 1, wherein the upper surface is snugly attached to the lower surface.