JP2865903B2 - Multilayer inductor element and its inductance adjustment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer inductor element capable of accurately adjusting an inductance value, and a method of adjusting the inductance value.

[0002]

2. Description of the Related Art Conventionally, laminated inductor elements have been generally manufactured by the following method. That is, first, N
A slurry obtained by mixing the i.Zn ferrite magnetic raw material powder and the organic binder is formed into a sheet having a uniform thickness by a doctor blade method or the like. Next, the pattern conductors distributed on the plurality of sheets are printed on each sheet with a conductive paste so that a spiral conductor coil is formed by laminating and connecting with through holes, and these patterns are printed. A predetermined number of sheets are stacked and pressed. After crimping, after firing in a state where both ends of the coil are respectively led out to a pair of opposed end surfaces, a conductive paste is applied to both end surfaces from which the coil ends are led out, and baked to form external electrodes, Obtain a multilayer inductor element.

On the other hand, when the inductance (L) value of the multilayer inductor element manufactured as described above deviates from a desired value, a processing machine using laser light irradiation or the like is used.
A method has been proposed in which the inductance value is adjusted by cutting and removing a ferrite substrate at a position corresponding to the coil core.

[0004]

In the above-described conventional laminated inductor element, the interval (ie, coil pitch) in the direction of the coil axis between adjacent pattern conductors in the internally provided spiral conductor coil is substantially constant. When the L value is adjusted by the above-described conventional inductance value adjustment method, the L value changes substantially in proportion to the depth from which the ferrite base is removed. Therefore, in order to finely adjust the L value, it is necessary to finely control the depth at which the ferrite base is removed. However, it is extremely difficult to minutely control the depth at which the ferrite substrate is removed, and it has been almost impossible to adjust the L value with high accuracy.

Accordingly, the present invention solves the above-mentioned problems of the prior art, and removes a ferrite base at a position corresponding to a coil core of a multilayer inductor element to adjust the inductance value, thereby rapidly increasing the inductance value. It is an object of the present invention to provide a multilayer inductor element that can be changed or finely adjusted with high accuracy and easily, and a method of adjusting the inductance value thereof.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and found that the spacing (coil pitch) of the orbiting pattern conductor in the direction of the coil axis is changed inside the ferrite magnetic material. It has been found that the fine adjustment of the inductance value can be performed with high accuracy and easily by providing a coil having a shape inside, and arrived at the present invention.

That is, the present invention firstly comprises a ferrite magnetic material and a helical conductor coil formed inside the ferrite magnetic material, and a coil axis of adjacent pattern conductors constituting each part of the coil. A laminated inductor element characterized in that the interval in the center direction (coil pitch) is sequentially enlarged (or reduced) from one side to the other side in the coil axis direction; The coil is composed of a helical conductor coil, and is a single continuous coil having the same axis in which two or more types of coils having different coil pitches are arranged in the order of the coil pitch. Thirdly, the coil pitch is gradually increased in the coil axis direction. -Shaped conductor coil, a laminated inductor element provided inside a ferrite magnetic material, or two or more helical conductor coils with different coil pitches are connected and integrated in series in the axial direction of the coil in ascending order of the coil pitch. Using a laminated inductor element in which a single continuous coil with the same axis is provided inside a ferrite magnetic material, a ferrite substrate is formed in the direction of the coil axis from the side of the conductor coil having a large coil pitch. An inductance adjustment method for easily performing high-precision fine-tuning of the inductance by removing the coil; fourthly, a helical conductor coil in which the coil pitch gradually increases in the direction of the coil axis becomes a ferrite magnetic material. Coupling a laminated inductor element or two or more spiral conductor coils with different coil pitches Using a laminated inductor element in which a conductor coil is connected and integrated in series in the axial direction of the coil in order from the one with the smallest pitch to make a single continuous coil with the same axis, which is installed inside the ferrite magnetic material And an inductance adjusting method for removing a large amount of ferrite from a conductor coil having a small coil pitch in the axial direction of the coil. Helical conductor coil whose size gradually increases in the direction of the coil axis is a laminated inductor element in which ferrite magnetic material is installed, or two or more types of helical conductor coils with different coil pitches are used from small coil pitch. One continuous coil with the same axis, connected and integrated in series in the axial direction of the coil in order Using a laminated inductor element in which the conductor coil is provided inside a ferrite magnetic material, first remove the ferrite material in the direction of the coil axis from the conductor coil side with the smaller coil pitch, adjust the inductance greatly, and then adjust the coil pitch. The object of the present invention is to provide an inductance adjusting method characterized in that a ferrite substrate is removed from the side of a conductor coil having a larger diameter in the axial direction of the coil to finely adjust the inductance.

[0008]

According to the present invention, the interval (coil pitch) of the spiral conductor pattern in the spiral conductor coil provided in the ferrite magnetic body in the coil axis direction is changed from one direction to the other in the coil axis direction. By sequentially expanding (or reducing), or by connecting two or more types of coils having different intervals (coil pitch) in series in the order of the coil pitch and integrating them, Fine adjustment and rapid change of the inductance value can be performed relatively easily. That is, in the multilayer inductor element, when removing the magnetic ferrite at a position corresponding to the coil core from the surface having the larger coil pitch toward the side having the smaller coil pitch,
The rate of change of the L value with respect to the amount of magnetic ferrite removed is small, and control of the amount removed is extremely easy. On the other hand, when the magnetic ferrite at the position corresponding to the coil core is removed from the surface having the smaller coil pitch toward the side having the larger coil pitch, the rate of change of the L value with respect to the magnetic ferrite removal amount is large. The L value can be rapidly changed by the removal amount. Therefore, L to be changed
If the direction in which the magnetic ferrite is removed, that is, the trimming direction, is selected in consideration of the value, the L value can be adjusted with high accuracy, efficiently, and easily.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by the following examples.

[0010]

Embodiment 1 The multilayer inductor element of the present invention can be manufactured by the following method. First, from 30μm to 70μ
A plurality of Ni / Zn-based ferrite green sheets 1 each having a thickness of 100 μm and having a thickness of 5 μm were prepared at predetermined intervals, and through holes 3 were formed at predetermined positions. Next, a conductor 2 having a pattern in which a helical coil was formed by laminating and connecting these sheets with through holes was printed on these sheets. After printing, as shown in FIG. 1, these sheets are laminated from bottom to top in order of thickness, and the upper and lower outermost layers have a thickness of 45% where no pattern is printed.
μm sheets were stacked and pressed.

Next, the pressed body was cut into a predetermined size to obtain a chip piece. The cutting was performed at a position where the end of the coil conductor was led out only to a pair of opposing end surfaces of the chip. After the chip obtained by cutting in this manner was fired, external electrodes were formed on a set of end faces from which the ends of the coil conductor were led out, to obtain a multilayer inductor element. The inductance (L) value of the multilayer inductor element thus obtained is
30 μH.

[0012] The inductance value of the manufactured laminated inductor element was adjusted. A laser beam having a spot diameter of 0.3 mm is radiated along the coil core from the surface having the larger coil pitch of the conductor coil provided in the multilayer inductor element, that is, the lower surface in the example of FIG. The magnetic material was sublimated and removed. In addition,
The trimming amount was defined as the depth at which the ferrite magnetic material was removed. The trimming amount was determined to be large when the ferrite magnetic material was deeply removed, and small when the ferrite magnetic material was removed shallowly.

As a result, the L value of 30 μH was changed to 29.5 μH
The trimming amount required to adjust to
The trimming amount required to adjust to 29.0μH is 0.8mm
Met. Therefore, in the above-mentioned laminated inductor element, since the trimming amount required to change the L value from 30 μH to 0.5 μH is relatively large at 0.6 mm, the L value during this period is relatively large.
Fine adjustment of the value can be easily performed with high accuracy.

[0014]

Embodiment 2 In a laminated inductor element manufactured in the same manner as in Embodiment 1, a spot is formed along the coil core from the surface of the inner conductor coil having the smaller coil pitch, that is, the upper surface in the example of FIG. A ferrite magnetic material was sublimated and removed by irradiating a laser beam having a diameter of 0.3 mm, and the inductance value was adjusted. As a result, 30μ
The trimming amount required to adjust the L value from H to 29.5 μH was 0.2 mm, and the trimming amount required to adjust the L value to 29.0 μH was 0.5 mm.

That is, when trimming is performed from the upper surface, the amount of trimming necessary to change the initial 0.5 μH is relatively small at 0.2 mm, and thereafter, the rate of change of the L value with respect to the cutting amount becomes small. In the case where fine adjustment is performed after the L value is largely changed, cutting is performed from the upper surface (the surface with the smaller coil pitch). In the case where only fine adjustment is performed, the lower surface (coil It is good to cut from the surface with the larger pitch).

[0016]

Comparative Example As a comparative example of the present invention, a conventional laminated inductor element was manufactured and its inductance value was adjusted. First, a Ni—Zn-based ferrite green sheet having a thickness of 45 μm was cut into a 100 mm square, and a through hole was formed at a predetermined position. Then on the sheet:
After printing a conductive pattern that forms a helical coil by laminating and connecting with through holes, it is laminated with a predetermined configuration, and a 45 μm thick sheet with no conductive pattern printed on the upper and lower outermost layers And crimped.

Next, the pressed body was cut into a predetermined size to obtain a chip piece. This cutting was performed at a position where the end of the coil conductor was led out only to a pair of opposing end surfaces of the chip. After the chip obtained by cutting in this manner was fired, external electrodes were formed on a set of end faces from which the ends of the coil conductor were led out, to obtain a multilayer inductor element. The inductance (L) value of the multilayer inductor element thus obtained is 30
μH.

The laminated inductor element produced above was irradiated with laser light from one surface in the coil axis direction in the same manner as in Example 1 to adjust the inductance value. As a result, the trimming amount required to adjust the L value from 30 μH to 29.5 μH is as small as 0.35 mm, and 29.0 μH.
The trimming amount required to adjust to μH is 0.6 mm, and the trimming amount required to adjust to 28.7 μH is
At 1.0 mm, the L value increased almost in proportion to the trimming amount.

[0019]

According to the laminated inductor element of the present invention, the interval (coil pitch) in the coil axis direction of the adjacent spiral conductor pattern in the internally provided spiral conductor coil.
Is gradually increased from one side to the other side of the coil axis direction, or two or more types of coils having different intervals are integrally formed, so that the inductance value changes rapidly by changing the trimming direction. And small changes can be easily and accurately performed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a lamination mode of a ferrite sheet at the time of manufacturing a multilayer inductor element of the present invention.

[Explanation of symbols]

 1) Ferrite green sheet 2) Conductor 3) Through hole

Claims (5)

(57) [Claims] The present invention comprises a ferrite magnetic material and a helical conductor coil formed inside the ferrite magnetic material, and a distance between adjacent ones of pattern conductors constituting each part of the coil in a coil axis direction is defined by a coil axis. A multilayer inductor element which is sequentially enlarged from one side to the other side in a center direction. 2. A ferrite magnetic body and a helical conductor coil formed inside the ferrite magnetic body, wherein the coil is the same in which two or more types of coils having different coil pitches are arranged in the order of the coil pitch. A multilayer inductor element, which is connected in series and integrally formed so as to form one continuous coil having an axis. 3. A laminated inductor element in which a helical conductor coil having a coil pitch gradually increasing in the direction of the coil axis is provided in a ferrite magnetic material, or two or more helical conductor coils having different coil pitches. Are connected in series in the direction of the axis of the coil in ascending order of coil pitch, and a continuous coil having the same axis is formed as a single continuous coil. A method of adjusting inductance, which comprises removing a ferrite material from a conductor coil side having a large coil pitch in a direction of a coil axis center using a coil. 4. A laminated inductor element in which a helical conductor coil having a coil pitch gradually increasing in a coil axis direction is provided in a ferrite magnetic material, or two or more helical conductor coils having different coil pitches Are connected in series in the direction of the axis of the coil in ascending order of coil pitch, and a continuous coil having the same axis is formed as a single continuous coil. An inductance adjustment method comprising removing a ferrite material from a conductor coil side having a small coil pitch in a direction of a coil axis center using a coil. 5. A laminated inductor element in which a helical conductor coil having a coil pitch gradually increasing in a coil axis direction is provided in a ferrite magnetic material, or two or more helical conductor coils having different coil pitches Are connected in series in the direction of the axis of the coil in ascending order of coil pitch, and a continuous coil having the same axis is formed as a single continuous coil. An inductance adjustment method that first removes the ferrite material from the conductor coil side having the smaller coil pitch in the coil axis direction, and then removes the ferrite material from the conductor coil side having the larger coil pitch in the coil axis direction.