JPH05217753A - Method for trimming composite electronic component - Google Patents

Abstract

PURPOSE:To develop a method in which a magnetic process is used for regener ating out-of-spec products that produced slight resonance frequency deviation occurring in the manufacturing process of a monolithic composite electronic component. CONSTITUTION:On a variable magnetic force electromagnet whose lines of magnetic force 5, can be controlled a composite electronic component 4 consisting of an inductor section 2 and a capacitor section 3 is placed, and the inductance value of the inductor section is adjusted by controlling the magnetic force, thereby to regulate and stabilize the resonance frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of trimming an inductor in a laminated composite electronic component, and more specifically, it applies a magnetic force to a magnetic material forming an inductor section to adjust the inductance value of a coiled conductor. And a trimming method for the electronic component inductor.

[0002]

2. Description of the Related Art Conventional laminated composite electronic components have slight variations in inductance value and capacitance value.
It often happens that the resonance frequency in the device to which the application circuit is set deviates from the target frequency. In order to correct this, a trimming method has been developed in which the inductance value is adjusted by, for example, scraping off a part of the magnetic material forming the composite component (Patent Application Publication No. 60-50046), sandblast trimming device, laser trimming device, etc. Is used to adjust the inductance value. However, when a part of the magnetic material is scraped off using the above-mentioned device to make a hole, (1) it is difficult to make a hole for trimming, and a hole is often made in the coil conductor pattern of the magnetic material. There is a risk that the inductance value will be opened, (2) If the inductance value deviates from the target value by scraping the magnetic material too much, it is impossible to reproduce, (3) Since a hole is formed on the back surface, there are inevitably problems that foreign matter easily enters and causes a failure.

[0003]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the object of the present invention is to adjust the inductor stance value without cutting a part of the magnetic material forming the inductor part to form a hole. It is to develop and provide a possible method.

[0004]

In order to solve such a problem, the present inventor has conducted earnest research and, as a result, applies a magnetic force of adjusted strength to a magnetic material forming an inductor section. It has been found that an inductance value corresponding to strength can be obtained in the inductor. That is, since the inductance value can be selected by adjusting the strength of the magnetic force applied, the required inductance value can be obtained without damaging the magnetic body by scraping off the magnetic body, and the resonance frequency of the inductor can be easily adjusted. The present invention has been accomplished by knowing that the target frequency can be tuned to.

There are the following two methods of applying a magnetic force. (1) Apply a direct current to the coil-shaped conductor embedded in the inductor. (2) Fig. 1 on the variable magnetic force type electromagnet 1 that can adjust the magnetic force lines 5.
The composite electronic component 4 including the inductor portion 2 and the capacitor portion 3 is placed as shown in FIG. FIG. 2 shows the relationship between the applied DC current strength (mA) and the inductance value (μH) of the inductor when a magnetic force is applied to the magnetic material by the method (1).

It can be seen that the inductance value does not change when the strength of the applied DC current is 10 mA or less, but gradually decreases when it exceeds 10 mA. If the inductance of the composite component is L and the capacitance value is C, the resonance frequency fo is

[0007]

[Chemical 1] It is represented by. Therefore, it can be seen from the above equation that if L decreases, fo increases.

FIG. 3 shows the relationship between the magnetic field strength (Gauss) and the inductance value (μH) when a magnetic force is applied to the magnetic material by the method (2). Magnetic field strength is 3
It can be seen that the inductance does not decrease until 0 gauss, but it gradually decreases above 0 gauss.

[0009]

[Function] When a magnetic force is applied to a magnetic body, the inductance of the coil-shaped conductor surrounding it does not immediately decrease, but changes appear only when the applied magnetic force exceeds a certain value, after which the strength of the magnetic force increases. As it does, the drop increases. This phenomenon will be described with reference to FIG. It is in the reversible magnetization range while the magnetic force of the magnetic field is very small. That is, within this range, if the magnetic force of the magnetic field disappears (H = 0), the residual magnetism of the magnetic material disappears (W = 0). If the strength of the magnetic field falls within the irreversible magnetization range exceeding this value, even if the magnetic force of the magnetic field disappears (H = 0), the residual magnetism indicated by OB remains in the magnetic substance (W> 0). This phenomenon is considered to be due to the residual magnetostriction in the sintered body due to the application of magnetic force to the magnetic body, but as a result, the inductance of the coil-shaped conductor surrounding the magnetic body decreases,
Moreover, the higher the strength of the magnetic field, the larger the ratio.

If too much magnetic force is applied to the magnetic substance, the magnetic strain disappears if the magnetic substance is heated again to a temperature just above the magnetic transformation temperature (Curie point), so that the initial state can be restored. That is, it is a feature of the method according to the present invention that reproduction can be performed by this method when trimming is excessively performed.

The present invention will be described in more detail with reference to the following examples.

[0012]

[Example 1] Using a known sheet method using soft ferrite powder, five layers of electrodes were alternately laminated with a dielectric material sandwiched in a capacitor portion, and an inductor portion was formed on a magnetic material sheet. A 20-turn winding coil was formed using the conductor pattern, and then compressed, fired, and sintered by an ordinary method to manufacture an LC laminated composite component having one capacitor and one inductor. Take out the extraordinary products from the obtained products,
The trimming method according to the present invention was performed.

The resonance circuit of this product is shown in FIG. The standard values are resonance frequency (fo) 3.58 MHz, capacitor capacity C: 110 pF, and inductance value: 18 μH. In order to confirm the effect of the present invention, an extraordinary product having an inductance value of 20 μH was taken out from the product and used as a sample. The resonance frequency is 3.39 MHz.

First, as a result of magnetizing a coil-shaped conductor through a direct current of 12 mA, C: 110 pF, L: 19 μH, and a resonance frequency (fo) of 3.48 MHz, 3.58 M
It did not reach Hz. Furthermore, as a result of passing a direct current of 20 mA, the L becomes 18 μH, and the resonance frequency fo: 3.58
It reached to MHz (Fig. 6) and the effect of the present invention was confirmed.

[0015]

Example 2 The test sample is the same as in Example 1. That is, the resonance frequency (fo) is 3.39 MHz with a capacitor capacity of 110 pF and an inductor value of 20 μF.

This was placed on a variable magnetic force type electromagnet by the method according to the present invention, and a magnetic field of 500 gauss was applied, resulting in C: 1.
10pF, L: 19μH, fo: 3.48MHz
Met. As a result of applying a magnetic field of 1000 gauss, C: 110 pF, L: 18 μH, fo: 3.58 MHz
As shown in FIG. 6, the effect of the present invention could be confirmed also in this example.

In the above-described embodiments, the parallel resonant circuit is shown as the laminated composite component in both the first and second embodiments.
The method of the present invention can be applied to a composite component forming a series resonance circuit or other composite components.

[0018]

As a result of the development of the present invention, a direct current is passed through the coil-shaped conductor that constitutes the inductor portion of the laminated composite electronic component, or the component is surrounded by the coil-shaped conductor by holding the component in a magnetic field. The inductance can be adjusted by applying a magnetic force to the magnetic body.
Therefore, there is no need to trim the part or trim the part, and if trimming is excessive, the part can be regenerated simply by heating to a temperature just above the magnetic transformation point (Curie point).

[Brief description of drawings]

FIG. 1 is an explanatory diagram related to a method of placing an LC composite component on a magnet and applying a magnetic force to a magnetic body of an inductor.

FIG. 2 is a diagram showing the relationship between the strength of a current flowing through a coil-shaped conductor forming an inductor section and the inductance value.

3 is a diagram showing a relationship between a magnetic field strength and an inductor value in the method shown in FIG.

FIG. 4 is a hysteresis loop diagram showing the relationship between magnetic field strength and residual magnetism, and is an explanatory diagram of an irreversible range.

FIG. 5 is a parallel resonant circuit of an LC composite component.

FIG. 6 is a diagram showing a transmission characteristic of a resonance frequency.

[Explanation of symbols]

 1 ... variable magnetic force type electromagnet 2 ... inductor section 3 ... capacitor section 4 ... composite electronic component 5 ... magnetic field lines

Claims (3)

[Claims] 1. An inductance value of a coiled conductor is adjusted by applying a magnetic force of adjusted strength to a magnetic material forming an inductor part of a laminated composite electronic component including a combination of an inductor part and a capacitor part. Trimming method of composite electronic component characterized by 2. The method according to claim 1, wherein a magnetic force is applied to the magnetic material by passing a direct current through a coil-shaped conductor embedded in the inductor portion of the electronic component. 3. The method of claim 1, wherein a magnetic force is applied to the magnetic body by holding the electronic component in an adjustable magnetic field.