JP3242022B2 - Inductance element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductor element used for components used in various electronic circuits.

[0002]

2. Description of the Related Art In recent years, various electronic components have been formed into chips due to miniaturization of components.

[0003] Among them, Japanese Patent Laid-Open No.
Japanese Patent Application Laid-Open No. 79706/79 has been proposed. With such a configuration, the noise component can be reduced in size.

FIG. 16 is a side view showing a conventional inductance element. In FIG. 16, 1 is a square pillar-shaped base,
2 is a conductive film formed on the base, 3 is a groove provided in the conductive film 2, and 4 is a protective material laminated on the conductive film 2. Such electronic components are adjusted to predetermined characteristics by adjusting the interval between the grooves and the like.

[0005]

However, the conventional configuration has a problem that it is difficult to manufacture a product having high impedance and high inductance.

An object of the present invention is to solve the above-mentioned conventional problems and to provide an inductance element capable of realizing high impedance and high inductance.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a conductive film formed on a base, a groove provided in the conductive film and the base, an insulating material provided to cover the groove, and a magnetic material. Materials and
And a protective material obtained by mixing, the protective material is provided with to have a magnetic in a groove provided in the base protective member, moreover coercive
A structure in which the ratio of insulating material is higher on the outside than on the inside of the protective material
And

[0008]

DETAILED DESCRIPTION OF THE INVENTION The invention according to a first aspect of the present invention relates to a base, a conductive film formed on the base, a groove provided in the conductive film and the base, and a groove formed in the base. An inductance element including a protective material provided so as to cover,
The protective material is a mixture of an insulating material and a magnetic material to impart magnetism to the protective material, and the protective material is provided in a groove provided in a base.
By percentage of charge is large, it is possible to provide a more element protective material having magnetism, can be realized a high impedance, the element having a high inductance, moreover protective material
Can be improved in mechanical strength.

According to a second aspect of the present invention, the electric current flowing through the protective material can be reduced by setting the electric resistance of the protective material to be 10 ⁷ cmΩ or more. Can be suppressed.

According to a third aspect of the present invention, in the first and second aspects, a protective material in which an insulating material made of at least one of resin and glass and a magnetic material are mixed is used.
Workability when forming the protective material can be improved,
Productivity can be improved, and variations in characteristics can be suppressed.

According to a fourth aspect of the present invention, an insulating property can be easily obtained by using an oxide magnetic material as the magnetic material in the third aspect.

According to a fifth aspect of the present invention, the use of ferrite as the oxide magnetic material in the fourth aspect is advantageous in terms of cost and is easy to process into powder.

According to a sixth aspect of the present invention, the density of the magnetic material in the protective material can be increased by setting the proportion of the insulating material to 20% by weight or less in the third to fifth aspects. A decrease in inductance can be prevented.

According to a seventh aspect of the present invention, in the third to sixth aspects, the average particle size of the pulverized particles of the magnetic material is 0.1 to 10%.
By setting the thickness to μm, the workability in forming the protective material can be improved, and furthermore, it is possible to prevent the magnetic material from being saturated and not being able to obtain sufficient characteristics. It can be easier.

[0015]

According to an eighth aspect of the present invention, in addition to the first to seventh aspects, further providing an insulating material layer on the protective material further increases the mechanical strength of the protective material, particularly the surface portion. Can be.

Hereinafter, embodiments of the inductance element and the wireless terminal device according to the present invention will be described.

FIGS. 1 and 2 are a perspective view and a side view showing an inductance element according to an embodiment of the present invention.

In FIG. 1, reference numeral 11 denotes a base which is formed by subjecting an insulating material or the like to press working, extrusion, or the like.
Reference numeral 2 denotes a conductive film provided on the base 11.
2 is formed on the base 11 by an evaporation method such as a plating method or a sputtering method. Reference numeral 13 denotes a groove provided in the base 11 and the conductive film 12. The groove 13 may be formed by irradiating the conductive film 12 with a laser beam or the like.
Is mechanically formed by applying a grindstone or the like to the surface. 14 is applied to a portion where the groove 13 of the base 11 and the conductive film 12 is provided,
The protection material 14 is a protection material having magnetism, and also enters the groove 13 provided in the base 11. As described above, by adopting a configuration in which the protective material 14 enters the groove 13 provided in each of the base 11 and the conductive film 12, it is possible to increase the application amount of the magnetic protective material 14, and the like.
An element with high impedance and high inductance can be obtained. Reference numerals 15 and 16 denote terminal portions on each of which terminal electrodes are formed. Between the terminal portions 15 and 16, a groove 13 and a protective material 14 are provided. FIG. 2 is a view in which a part of the protection member 14 is removed.

The inductance element according to the present embodiment has a length L1, a width L2, and a height L3 of the inductance element.
Is preferably as follows.

L1 = 0.5 to 2.1 mm (preferably 0.6 to 1.0 mm) L2 = 0.2 to 1.3 mm (preferably 0.3 to 0.6 mm)
mm) L3 = 0.2 to 1.3 mm (preferably 0.3 to 0.6)
mm) When L1 is 0.5 mm or less, the self-resonant frequency f0 is lowered and the Q value is lowered, so that good characteristics cannot be obtained. Further, if L1 exceeds 2.1 mm, the element itself becomes large, and a substrate or the like on which an electronic circuit or the like is formed (hereinafter abbreviated as a circuit substrate or the like)
It is not possible to reduce the size of a circuit board or the like, and thus it is impossible to reduce the size of an electronic device or the like on which the circuit board or the like is mounted.
When L2 and L3 are each 0.2 mm or less,
The mechanical strength of the element itself becomes too weak, and when the element is mounted on a circuit board or the like by a mounting device or the like, the element may be broken. On the other hand, if L2 and L3 are 1.3 mm or more, the elements become too large, and it is impossible to reduce the size of the circuit board and the like, and furthermore, the size of the device. Note that L4 (depth of step drop) is preferably about 5 μm to 50 μm, and if it is 5 μm or less, the thickness and the like of the protective material 14 must be reduced, and good protection characteristics and the like cannot be obtained. On the other hand, if L4 exceeds 50 μm, the mechanical strength of the base is weakened, which may also cause element breakage.

With respect to the inductance element configured as described above, each part will be described in detail below. FIG. 3 is a cross-sectional view of a base on which a conductive film used for an inductance element according to one embodiment of the present invention is formed, and FIGS. 4 (a) and 4 (b).
FIG. 2 is a diagram showing a base used for an inductance element according to one embodiment of the present invention.

First, the shape of the base 11 will be described.
As shown in FIGS. 3 and 4, the base 11 is provided with a central portion 11a having a rectangular cross section and both ends of the central portion 11a so as to be easily mounted on a circuit board or the like. It is constituted by ends 11b and 11c. Although the end portions 11b and 11c and the central portion 11a have a rectangular cross section, they may have a polygonal shape such as a pentagonal shape or a hexagonal shape. The central portion 11a is configured to drop down from the end portions 11b and 11c. In the present embodiment, the end portions 11b, 1
By making the cross-sectional shape of 1c substantially square, the mountability of the inductance element to a circuit board or the like was improved.
Further, in the present embodiment, the groove 13 is provided laterally in the central portion 11a.
Is formed, there is no direction even if it is mounted on a circuit board or the like, so that the handling becomes easy. Further, an element portion (the groove 13 and the protective material 14) is formed in the central portion 11a, and terminal portions 15 and 16 are formed in the end portions 11b and 11c.

In this embodiment, both the central portion 11a and the end portions 11b and 11c are substantially square.
The shape may be a regular polygon such as a regular pentagon. Furthermore, in the present embodiment, the central section 11a and the end sections 11c and 11b have the same cross-sectional shape such as a regular square.
May be different. That is, the cross-sectional shape of the end portions 11b and 11c may be a regular polygonal shape, and the cross-sectional shape of the central portion 11a may be another polygonal shape or a circular shape. Central part 11a
The groove 13 can be formed satisfactorily by making the cross-sectional shape circular.

Further, in this embodiment, the central portion 11a
By stepping down from the ends 11b and 11c,
When the protective material 14 was applied, contact between the protective material 14 and a circuit board or the like was prevented.
The center part 11a depends on the thickness of the circuit board 4 and the condition of the circuit board or the like to be mounted (a groove is formed in a part where the circuit board or the like is mounted, or an electrode portion of the circuit board or the like is raised).
Need not be dropped. Center 11a to end 11
If the step is not dropped from b and 11c, the structure of the base 11 is simplified, the productivity is improved, and the mechanical strength of the central portion 11a is also improved. Even if you do not let the steps drop like this,
It may be a quadrangular prism having a quadrangular cross section, or a prism having a polygonal cross section.

As shown in FIG. 4A, the heights Z1 and Z2 of the ends of the base 11 preferably satisfy the following conditions.

| Z1-Z2 | ≦ 80 μm (preferably 50 μm) The height difference between Z1 and Z2 is 80 μm (preferably 50 μm).
m or less), when the element is mounted on a circuit board and attached to a circuit board or the like with solder or the like, the element is pulled to one end by surface tension of the solder or the like, and the element stands up. The probability of occurrence is very high. This Manhattan phenomenon is shown in FIG. As shown in FIG. 5, an inductance element is arranged on a substrate 200,
Solder 20 between each of terminal portions 15 and 16 and substrate 200
Although the solders 201 and 202 are provided, when the solders 201 and 202 are melted by reflow or the like, the molten solders 201 and 202 are melted due to a difference in the application amount of each of the solders 201 and 202 and a difference in melting point due to a difference in material. 5 differs between the terminal portion 15 and the terminal portion 16, and as a result, as shown in FIG. 5, one of the terminal portions (the terminal portion 1 in FIG.
5), the inductance element rises. If the difference between the heights of Z1 and Z2 exceeds 80 μm (preferably 50 μm or less), the elements are arranged on the substrate 200 in an inclined state, and the standing of the elements is promoted. In addition, the Manhattan phenomenon occurs remarkably particularly in small and lightweight chip-type electronic components (including a chip-type inductance element), and one of the causes of the Manhattan phenomenon is the difference in height between the terminal portions 15 and 16. It was noted that the device was inclined and was arranged on the substrate 200. As a result, by forming the base 11 by molding or the like so that the difference between the heights of Z1 and Z2 is 80 μm or less (preferably 50 μm or less), the occurrence of the Manhattan phenomenon could be significantly suppressed. . By setting the difference between the heights of Z1 and Z2 to 50 μm or less, the occurrence of the Manhattan phenomenon can be substantially suppressed.

Next, the chamfering of the base 11 will be described.
FIG. 6 is a perspective view of a base used for the inductance element according to one embodiment of the present invention. As shown in FIG. 6, each corner 1 of the ends 11 b and 11 c of the base 11 is provided.
The chamfered edges 1e and 11d are preferably formed, and the radius of curvature R1 of the chamfered corners 11e and 11d and the radius of curvature R2 of the corner 11f of the central portion 11a are preferably formed as follows.

0.03 <R1 <0.15 (mm) 0.01 <R2 (mm) If R1 is less than 0.03 mm, the corners 11e and 11d
Since the corners are sharp, the corners 11e and 11d may be chipped due to a slight impact or the like, and the chipping may cause deterioration of characteristics or the like. When R1 is 0.15 mm or more, the corner 11
Since e and 11d are too round, the above-mentioned Manhattan phenomenon is likely to occur, which causes a problem. Furthermore, when R2 is 0.
When the thickness is less than 01 mm, burrs and the like are likely to be generated on the corners 11f, and the thickness of the conductive film 12, which is formed on the central portion 11a and greatly affects the characteristics of the element, differs greatly between the corners 11f and the flat portion. And the variation in element characteristics becomes large.

Next, the constituent materials of the base 11 will be described. It is preferable to satisfy the following characteristics as a constituent material of the base 11.

Volume resistivity: 10 ¹³ or more (preferably 10 ¹⁴ or more) Thermal expansion coefficient: 5 × 10 ⁻⁴ or less (preferably 2 × 10 ⁻⁵ or less) [Coefficient of thermal expansion at 20 ° C. to 500 ° C.] Dielectric constant : 1 or less at 1 MHz (preferably 10 or less) Flexural strength: 1300 kg / cm ² or more (preferably 20
(00 kg / cm ² or more) Density: ^{2 to 5} g / cm ³ (preferably ³ to 4 g / cm ³ ) When the constituent material of the base 11 has a volume resistivity of 10 ¹³ or less, the base 11 together with the conductive film 12 Also, since a current starts to flow in a predetermined manner, a parallel circuit is formed, and the self-resonant frequency f0 and the Q value become low, which is not suitable for a high-frequency element.

If the coefficient of thermal expansion is 5 × 10 ⁻⁴ or more, cracks may occur in the base 11 due to heat shock or the like. In other words, when the thermal expansion coefficient is 5 × 10 ⁻⁴ or more, the laser beam or the grindstone is used when forming the groove 13 as described above. Although cracks and the like may occur, the occurrence of cracks and the like can be largely suppressed by having the above-described coefficient of thermal expansion.

If the dielectric constant is 12 or more at 1 MHz, the self-resonant frequency f0 and the Q value become low, which is not suitable for a high-frequency device.

If the bending strength is 1300 kg / cm ² or less, the device may be broken when mounted on a circuit board or the like by a mounting apparatus.

When the density is 2 g / cm ³ or less, the base 1
1, the water absorption rate is increased, the characteristics of the base 11 are significantly deteriorated, and the characteristics as an element are deteriorated. The density is 5 g / c
If it exceeds m ³ , the weight of the base will be heavy, and there will be a problem in mountability and the like. In particular, when the density is set within the above range, the water absorption rate is small, the water hardly enters the base 11, and the weight is light, so that there is no problem when mounting the chip on a substrate by a chip mounter or the like.

By defining the volume resistivity, thermal expansion coefficient, dielectric constant, bending strength, and density of the base 11 as described above, the self-resonant frequency f0 and the Q value do not decrease. It is possible to suppress the occurrence of cracks and the like in the base 11 due to heat shock or the like, so that the defect rate can be reduced, and further, the mechanical strength can be improved. Therefore, excellent effects such as an improvement in productivity can be obtained.

As a material for obtaining the above-mentioned various properties, a ceramic material containing alumina as a main component can be used. However, simply using a ceramic material mainly composed of alumina cannot obtain the above-mentioned characteristics. That is,
Since the above-mentioned various characteristics vary depending on the pressing pressure, the sintering temperature, and the additives at the time of producing the base 11, the production conditions and the like must be appropriately adjusted. Specific manufacturing conditions include a pressing pressure of 2 to 5 tons when processing the base 11, a firing temperature of 1500 to 1600 ° C., and a firing time of 1 to 3 hours. Specific examples of the alumina material include Al ₂ O ₃ of 92 wt% or more, SiO ₂ of 6 wt% or less, MgO of 1.5 wt% or less, and Fe ₂ O ₃ of 0.1 wt% or less.
% Or less, and Na ₂ O of 0.3% by weight or less.

When an inductance element is used as a noise component, the base 11 is preferably made of a magnetic material. Among magnetic materials, a ferrite material is preferable, particularly in view of workability and cost. Further, a magnetic material, which has an insulating property, is most preferable. As these specific materials, materials composed of at least one soft ferromagnetic material such as Mn-Zn ferrite and Ni-Zn ferrite are preferable.

Next, the surface roughness of the base 11 will be described. The surface roughness described below means the average roughness of the center line, and the roughness described in the description of the conductive film 12 is also the average roughness of the center line.

The surface roughness of the base 11 is 0.15 to 0.5 μm
m, preferably about 0.2 to 0.3 μm. FIG. 7 is a graph showing the surface roughness and the rate of occurrence of peeling of a base used for an inductance element according to an embodiment of the present invention. FIG. 7 shows the results of an experiment as described below. The base 11 and the conductive film 12 are made of alumina and copper, respectively. Samples with various surface roughnesses of the base 11 are prepared, and the conductive film 12 is formed on each sample under the same conditions.
Was formed. Perform ultrasonic cleaning on each sample,
Thereafter, the surface of the conductive film 12 was observed to determine whether or not the conductive film 12 had peeled off. The surface roughness of the base 11 was measured using a surface roughness measuring device (574A, manufactured by Tokyo Seimitsu Surfcom Co., Ltd.), and had a tip R of 5 μm. As can be seen from the result, when the average surface roughness is 0.15 μm or less, the peeling rate of the conductive film 12 formed on the base 11 is 5%.
%, And good bonding strength between the base 11 and the conductive film 12 can be obtained. Further, if the surface roughness is 0.2 μm or more, peeling of the conductive film 12 hardly occurs. Therefore, if possible, the surface roughness of the base 11 is preferably 0.2 μm or more. Since the peeling of the conductive film 12 is a major factor in deterioration of the characteristics of the device, the rate of occurrence is 5 from the viewpoint of yield and the like.
% Or less is preferable.

FIG. 8 is a graph showing the relationship between the frequency and the Q value with respect to the surface roughness of the base used for the inductance element according to one embodiment of the present invention. FIG. 8 shows the results of the following experiment. First, each sample of the base 11 having a surface roughness of 0.1 μm or less, the base 11 having a surface roughness of 0.2 to 0.3 μm, and the base 11 having a surface roughness of 0.5 μm or more was prepared. Then, a conductive film having the same thickness and the same material (copper) was formed on each sample. Then, in each sample, the Q value at a predetermined frequency F was measured. As can be seen from FIG. 8, the surface roughness of the base 11 is 0.5 μm.
If it is more than m, a decrease in the Q value, which is considered to be caused by the deterioration of the film structure of the conductive film 12, is observed. Particularly in the high frequency region, the Q value is significantly deteriorated. Also, the self-resonant frequency f0 (maximum value of each line) has a surface roughness of 0.5
Those of μm are shifted to the lower frequency side. Therefore, the surface roughness of the base 11 is preferably 0.5 μm or less from the viewpoint of the Q value and the surface of the self-resonant frequency f0.

As described above, judging from the results of both the adhesion strength between the conductive film 12 and the base 11, the Q value of the conductive film, and the self-resonant frequency f0, the surface roughness of the base 11 is 0.15.
μm to 0.5 μm, more preferably 0.2 μm
０．３0.3 μm is good.

It is preferable that the end portions 11b and 11c and the center portion 11a have different average surface roughnesses. That is, the average surface roughness of the end portions 11b and 11c is set in the central portion 1 within the range of 0.15 to 0.5 μm.
It is preferable to make the average surface roughness smaller than 1a.
Since the terminal portions 15 and 16 are formed by laminating the conductive films 12 on the end portions 11b and 11c as described above, the surface roughness of the end portions 11b and 11c is made smaller than that of the central portion 11a, so that the end portions 11b and 11c are formed. Since the surface roughness of the conductive film 12 formed on 11b and 11c can be reduced, the adhesion to electrodes such as a circuit board can be improved, and the inductance element can be securely bonded to the circuit board and the like. it can. Further, a conductive film 12 is laminated on the central portion 11a to form a groove 13
Is formed, so that the conductive film 12 does not come off from the base 11 when the groove 13 is formed by a laser or the like.
Therefore, it is preferable that the surface roughness of the central portion 11a is larger than that of the end portions 11b and 11c because the adhesion strength between the base 11 and the base 11 must be improved. In particular, when the groove 13 is formed by laser, the temperature of the portion irradiated with the laser rises more rapidly than other portions, and the conductive film 12 may peel off due to heat shock or the like. Therefore, when the grooves 13 are formed by laser, it is necessary to increase the bonding density between the conductive film 12 and the base 11 as compared with other portions.

As described above, the center portion 11a and the end portions 11b, 11
By making the surface roughness different from that of c, it is possible to prevent the conductive film 12 from peeling off at the time of forming the groove 13 and the adhesion to a circuit board or the like.

In the present embodiment, the bonding strength between the conductive film 12 and the base 11 is improved by adjusting the surface roughness of the base 11.
2 to improve the adhesion strength between the conductive film 12 and the base 11 without adjusting the surface roughness by providing an intermediate layer composed of Cr alone or an alloy of Cr and another metal. Can be. Of course, when the surface roughness of the base 11 is adjusted and the intermediate layer and the conductive film 12 are laminated on the base 11, it is possible to obtain a stronger adhesion strength between the conductive film 12 and the base 11. it can.

Next, the conductive film 12 will be described. The conductive film 12 preferably has a small inductance of 50 nH or less and a Q value of 30 or more for a high frequency signal of 800 MHz or more. Conductive film 1 having such characteristics
In order to obtain 2, it is necessary to select a material and a manufacturing method.

Hereinafter, the conductive film 12 will be specifically described. Examples of a constituent material of the conductive film 12 include conductive materials such as copper, silver, gold, and nickel. A predetermined element may be added to the material such as copper, silver, gold, and nickel to improve weather resistance and the like. Alternatively, an alloy such as a conductive material and a nonmetallic material may be used. Copper and its alloys are often used as constituent materials in terms of cost, corrosion resistance, and ease of fabrication. When copper or the like is used as the material of the conductive film 12, first, a base film is formed on the base 11 by electroless plating, and a predetermined copper film is formed on the base film by electrolytic plating. The conductive film 12 is formed. Further, when the conductive film 12 is formed of an alloy or the like, it is preferable to form the conductive film 12 by a sputtering method or a vapor deposition method. When copper or an alloy thereof is used as a constituent material, the thickness of the conductive film 12 is preferably 15 μm or more. If the thickness is less than 15 μm, the conductive film 12
Is small, and it is difficult to obtain a predetermined characteristic. FIG. 9 is a graph showing the relationship between the film pressure of the conductive film used for the inductance element and the Q value in one embodiment of the present invention. Copper is used as a constituent material of the conductive film 12, and a material and a surface roughness of the base 11 are set under the same conditions.
The thickness of the conductive film 12 formed on the base 11 was changed, and the Q value in each case was measured. As can be seen from FIG. 9, when the thickness of the conductive film 12 is 15 μm or more,
The Q value exceeds 30. The thickness of the conductive film 12 is 1
In the region of 5 μm or more, the Q value is not so much improved, and the film thickness of the conductive film 12 is 35 μm in order to reduce the cost and the defective rate.
It is preferable that the thickness be not more than μm. The thickness of the conductive film 12 is more preferably 21 μm or more.

The conductive film 12 may be composed of a single layer, but may have a multilayer structure. That is, a plurality of conductive films having different constituent materials may be stacked. For example, first, a copper film is formed on the base 11, and then a metal film having good weather resistance (such as nickel) is laminated thereon, so that corrosion of copper, which is somewhat problematic in weather resistance, can be prevented. .

Examples of the method for forming the conductive film 12 include a plating method (such as an electrolytic plating method and an electroless plating method), a sputtering method, and a vapor deposition method. Among these forming methods,
A plating method with good mass productivity and small variations in film thickness is often used.

The surface roughness of the conductive film 12 is preferably 1 μm or less, more preferably 0.2 μm or less. When the surface roughness of the conductive film 12 exceeds 1 μm, the Q value at high frequencies decreases due to the skin effect. FIG. 10 is a graph showing the relationship between the frequency and the Q value with respect to the surface roughness of the conductive film used for the inductance element according to one embodiment of the present invention. FIG. 10 was derived through the following experiment.
First, a conductive film 12 made of copper is formed on a base 11 having the same size and the same material with the same surface roughness while changing the surface roughness. Was measured. As can be seen from FIG.
If the surface roughness of No. 2 is 1 μm or more, it can be seen that the Q value in the high frequency region is low. Further, it can be seen that when the surface roughness of the conductive film 12 is 0.2 μm or less, the Q value particularly in a high frequency region is extremely high.

As described above, the surface roughness of the conductive film 12 is 1.
The thickness is preferably 0 μm or less, and more preferably 0.2 μm or less, the skin effect of the conductive film 12 can be reduced, and the Q value particularly at high frequencies can be improved.

Further, the adhesion strength between the conductive film 12 and the base 11 is as follows:
After leaving the base 11 on which the conductive film 12 is formed at a temperature of 400 ° C. for a few seconds, it is preferable that the conductive film 12 be separated from the base 11 by a degree or more. When the element is mounted on a substrate or the like, a temperature of 200 ° C. or more may be applied to the element due to self-heating or heat from other members. Therefore, the conductive film 12 from the base 11 at 400 ° C.
If the adhesion strength is such that no peeling occurs, even if heat is applied to the element, the characteristics of the element do not deteriorate.

Next, the protective member 14 will be described. As the protective material 14, an organic material having excellent weather resistance and insulating properties,
For example, a material having an insulating property such as an epoxy resin is used. Further, it is preferable that the protective material 14 has a transparency such that the condition of the groove 13 can be observed. Protective material 14
When a material having transparency is used, the shape of the groove 13, the number of turns of the groove 13, the peeling of the conductive film 12 around the groove 13, and the like can be observed even after the protective material 14 is formed, and the defective product is found. Greatly contributes to In particular, the conductive film 1 around the groove 13
Peeling of 2 may cause deterioration of characteristics with the passage of time, and it is very useful to know the peeling of this conductive film before shipment. Further, it is preferable that the protective material 14 has a predetermined color while having transparency.
The protective material 14 is made of a conductive film 12 such as red, blue, or green,
By coloring different colors such as 5, 16 and the like, it is possible to distinguish each part of the element (a part where a terminal part and a groove are formed), and to easily inspect each part of the element. Especially terminal part 1
If a defective portion (peeling of the electrode film or the like) is generated in the portions 5 and 16, an element may not be properly attached to the substrate during a process such as reflow. Also,
By changing the color of the protective material 14 in at least one of the size of the element, the width of the groove 13, the type and thickness of the conductive film 12, and the material of the base 11, an element having a different characteristic or part number can be erroneously determined. It is possible to reduce mistakes such as attachment to a part. Further, the sorting of the finished product can be easily performed, so that the productivity is improved. In addition, by changing the color of the protective member 14 depending on the type of electronic device, etc., the same electronic device uses the same color inductance element as the protective member 14 so that an incorrect component is mounted on the substrate. Can be prevented.

Therefore, the protection member 14 is provided with the terminal portions 15 and 16.
Is provided so that it is exposed and colored according to the characteristics etc.
Moreover, by providing transparency, the type of the inductance element can be easily determined, and the terminal portions 15 and 1 can be easily determined.
6 can be easily inspected (since the portion where the groove 13 is formed is covered with a protective material) and the state of the groove 13 can be easily observed, so that the process control is very easy. And productivity is improved. On the other hand, in a configuration in which an opaque resin or the like is provided so as to cover the entire element like a conventional resistor, the terminal portion is not exposed after the opaque resin is applied, and the terminal portion cannot be observed. Defective products cannot be found, and grooves 13 formed by laser, grinding stone, etc.
It is very difficult to find a defective product because the peeling of the conductive film in the peripheral portion cannot be found.

As shown in FIG. 11, the protection member 14 has a length Z1 between the corner 13a of the groove 13 and the surface of the protection member 14.
Is preferably 5 μm or more. Z
When 1 is smaller than 5 μm, it is conceivable that characteristic deterioration, discharge, and the like are likely to occur, and the characteristics of the element are significantly deteriorated.
In addition, the corner 13a of the groove 13 is a portion where discharge or the like is particularly likely to occur, and it is highly preferable that a protective material 14 having a thickness of 5 μm or more is formed on the corner 13a. In some cases, after the protective material 14 is formed, plating is performed again to form an electrode film or the like. However, if the protective material 14 having a thickness of 5 μm or more is not formed on the corners 13a, the electrode film or the like may adhere. Thus, an electrode film or the like is formed on the protective material 14 in which the characteristics are deteriorated, and the characteristics are deteriorated.

Further, by providing the protective member 14 with magnetism, it can be particularly usefully functioned as a noise component. At this time, the electric resistance of the protective material 14 is 10 ⁷ c
By setting the resistance to mΩ or more, the current flowing through the protective member 14 can be reduced, and deterioration of characteristics can be prevented. As a constituent material of the protective material 14, a mixture of an insulating material made of a resin material such as an epoxy resin, a liquid crystal polymer, a plastic, or a glass material, and a powder of a magnetic material is used. As the magnetic material, an oxide magnetic material which can be easily processed into a powder and has a high insulating property is suitably used, and in particular, a soft ferromagnetic material such as Mn-Zn ferrite or Ni-Zn ferrite is preferably used. At this time, the mixing ratio of the insulating material and the magnetic material is 20% by weight of the insulating material.
Hereinafter, the magnetic material is preferably 80% by weight or more. Furthermore,
The average particle size of the pulverized particles of the magnetic material is preferably 0.1 to 10 μm. When the average particle size is 0.1 μm or less,
When the magnetic material is saturated, desired characteristics cannot be obtained, and when the average particle diameter is 10 μm or more, it is difficult to enter the groove 13 provided in the base 11.

FIG. 12 is a graph showing the relationship between the frequency and the impedance when the protective material used in the inductance element according to the embodiment of the present invention is in the groove and when it is not.

As can be seen from the graph of FIG.
It can be seen that the impedance is higher when the protective material 14 is provided inside than when it is not provided. As described above, in the present embodiment, in addition to the groove 13 provided in the conductive film 12, the base 11
A high impedance element can be formed by providing a configuration in which the magnetic protective material 14 is provided in the groove 13 provided in the device. Further, since the protection member 14 is configured to enter the groove 13 provided in the base 11, the bonding strength between the base 11 and the protection member 14 can be improved. Groove 1
By adjusting the depth of 3, the amount of the protective material 14 entering the groove 13 can be adjusted, so that the impedance can be adjusted to some extent. Further, it is preferable that air bubbles and the like do not enter the protection member 14 entering the groove 13.

Further, in order to improve the mechanical strength of the protective member 14 (particularly, the mechanical strength of the surface portion that comes into contact with other parts, etc.), the surface portion of the protective member 14 is more than the other portions. It is preferable to increase the content ratio of the insulating material.
Furthermore, in order to improve the mechanical strength of the protective material 14,
A protective member such as glass or resin may be further provided on the protective member 14.

Next, the terminals 15 and 16 will be described.
Although the terminal portions 15 and 16 function satisfactorily even with the conductive film 12 alone, it is preferable that the terminal portions 15 and 16 have a multilayer structure in order to adapt to various environmental conditions and the like.

FIG. 13 is a sectional view of a terminal portion of an inductance element according to an embodiment of the present invention. In FIG. 13, a conductive film 12 is formed on an end 11b of a base 11, and a protective layer 300 made of a weather-resistant material such as nickel or titanium is formed on the conductive film 12. Further, a bonding layer 301 made of solder or the like is formed on the protective layer 300. The protective layer 300 improves the bonding strength between the bonding layer and the conductive film 12, and
The weather resistance of the conductive film can be improved. In the present embodiment, at least one of nickel and a nickel alloy is used as a constituent material of the protective layer 300, and solder is used as a constituent material of the bonding layer 301. Protective layer 300 (nickel)
The thickness is preferably 2 to 7 μm, and if it is less than 2 μm, the weather resistance is deteriorated, and if it is more than 7 μm, the electric resistance of the protective layer 300 (nickel) itself is increased, and the element characteristics are greatly deteriorated. The thickness of the bonding layer 301 (solder) is 5 μm to 1 μm.
It is preferably about 0 μm, and if it is less than 5 μm, a solder erosion phenomenon occurs and good bonding between the element and the circuit board cannot be expected. If it is more than 10 μm, the Manhattan phenomenon easily occurs and the mountability is very poor. Become.

The inductance element configured as described above has no characteristic deterioration and has very good mountability and productivity.

The method of manufacturing the inductance element having the above configuration will be described below.

First, the base 11 is manufactured by pressing or extruding an insulating material such as alumina. Next, a conductive film 12 is formed on the entire base 11 by a plating method, a sputtering method, or the like. Next, a spiral groove 13 is formed in the base 11 on which the conductive film 12 is formed. The groove 13 is formed by laser processing or cutting. Since the laser processing has very high productivity, the laser processing will be described below. First, the base 11 is mounted on a rotating device, the base 11 is rotated, and a laser is applied to the central portion 11a of the base 11 to remove both the conductive film 12 and the base 11, thereby forming a spiral groove. I do. At this time, an excimer laser, a carbon dioxide gas laser, or the like can be used as the laser, and the laser beam is focused on the central portion 11a of the base 11 by narrowing the laser beam with a lens or the like. Further, the groove 13
The depth or the like can be adjusted by adjusting the power of the laser, and the width or the like of the groove 13 can be adjusted by exchanging a lens when narrowing down the laser beam. Also, depending on the constituent material of the conductive film 12, etc.,
Since the laser absorptivity is different, it is preferable that the type of laser (laser wavelength) be appropriately selected depending on the constituent material of the conductive film 12.

After the groove 13 is formed, a protective material 14 is applied to the portion where the groove 13 is formed (the central portion 11a) and dried. At this time, the protective material 14 has an inductance value of the element,
As described above, the color of the device is varied by at least one of the following: the corresponding frequency of the device, the size of the device, the width of the groove, the type and thickness of the conductive film, and the material of the base. Management such as sorting becomes very easy, and productivity is improved.

At this point, the product is completed, but in particular, a nickel layer or a solder layer may be laminated on the terminal portions 15 and 16 to improve the weather resistance and the joining property. The nickel layer and the solder layer are formed on a semi-finished product on which the protective material 14 is formed by a plating method or the like.

Although the present embodiment has been described with respect to an inductance element, the same effect can be obtained with an electronic component in which a conductive film is formed on a base made of an insulating material.

FIGS. 14 and 15 are a perspective view and a block diagram showing a wireless terminal device according to one embodiment of the present invention. 14 and 15, reference numeral 29 denotes a microphone for converting a voice into a voice signal, 30 denotes a speaker for converting a voice signal into a voice, 31 denotes an operation unit including dial buttons and the like, and 32 denotes a display unit for displaying an incoming call or the like , 33 are antennas,
A transmission unit 34 demodulates an audio signal from the microphone 29 and converts it into a transmission signal. The transmission signal produced by the transmission unit 34 is emitted outside through an antenna. A receiving unit 35 converts a received signal received by the antenna into an audio signal.
The audio signal created by the receiving unit 35 is converted into audio by the speaker 30. A control unit 36 controls the transmission unit 34, the reception unit 35, the operation unit 31, and the display unit 32.

Hereinafter, an example of the operation will be described. First, when there is an incoming call, the receiving unit 35 sends the
The control unit 36 displays a predetermined character or the like on the display unit 32 based on the incoming signal,
Further, when a button or the like for receiving an incoming call is pressed from the operation unit 31, a signal is sent to the control unit 36, and the control unit 36
Set each part to the incoming call mode. That is, the signal received by the antenna 33 is converted into an audio signal by the receiving unit 35, and the audio signal is output from the speaker 30 as audio.
The voice input from the microphone 29 is converted into a voice signal, and is transmitted to the outside via the transmitting unit 34 and the antenna 33.

Next, a case of transmitting a call will be described. First, when transmitting a signal, a signal indicating that the signal is transmitted from the operation unit 31 is input to the control unit 36. Subsequently, when a signal corresponding to the telephone number is transmitted from the operation unit 31 to the control unit 36, the control unit 36 transmits a signal corresponding to the telephone number from the antenna 33 via the transmission unit 34. When communication with the other party is established by the transmission signal, a signal to that effect is sent to the control unit 36 through the reception unit 35 via the antenna 33, and the control unit 36 sets each unit to the transmission mode. That is, the signal received by the antenna 33 is converted into an audio signal by the receiving unit 35, the audio signal is output as audio from the speaker 30, and the audio input from the microphone 29 is converted into an audio signal, Through the antenna 33 to the outside.

The inductance element described above (FIG. 1)
13 to FIG. 13) are used for a filter circuit, a matching circuit, and the like in the transmission unit 34 and the reception unit 35, and the number thereof is about several to 40 for one wireless terminal device. I have. By using the inductance element having the above-described configuration, good noise removal characteristics can be obtained, so that occurrence of malfunction of the device can be suppressed.

When an inductance element is used as a noise component, it is used as a noise countermeasure component such as a clock line, a high-speed bus line, and a high-speed analog line of a personal computer, a word processor, a communication device, a digital TV, a VTR, and the like. You. Further, it is also used as a noise suppression component of a power supply circuit.

The present invention relates to a conductive film formed on a base.
And a groove provided in the conductive film and the base, and covering the groove.
Protection provided by mixing insulating and magnetic materials
The protective material has magnetism and is installed on the base.
Protective material is provided in the groove, and from the inside of the protective material
The outside is also configured so that the proportion of insulating material is higher,
As the amount of protective material applied can be increased, high impedance and high inductance elements can be obtained .
Moreover, the mechanical strength of the protective material can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an inductance element according to an embodiment of the present invention.

FIG. 2 is a side view showing the inductance element according to the embodiment of the present invention;

FIG. 3 is a cross-sectional view of a base on which a conductive film used for an inductance element according to an embodiment of the present invention is formed.

FIG. 4 is a diagram showing a base used for an inductance element according to one embodiment of the present invention;

FIG. 5 is a side view showing the Manhattan phenomenon.

FIG. 6 is a perspective view of a base used for the inductance element according to the embodiment of the present invention.

FIG. 7 is a graph showing the surface roughness and the rate of occurrence of peeling of a base used for an inductance element according to an embodiment of the present invention.

FIG. 8 is a graph showing a relationship between a frequency and a Q value with respect to a surface roughness of a base used for an inductance element according to an embodiment of the present invention.

FIG. 9 is a graph showing a relationship between a film pressure of a conductive film used for an inductance element and a Q value according to one embodiment of the present invention.

FIG. 10 is a graph showing a relationship between frequency and Q value with respect to surface roughness of a conductive film used for an inductance element according to one embodiment of the present invention.

FIG. 11 is a side view of a portion provided with a protective material for an inductance element according to an embodiment of the present invention.

FIG. 12 is a graph showing a relationship between frequency and impedance when a protective material used in an inductance element according to an embodiment of the present invention is in a groove and not in a groove.

FIG. 13 is a sectional view of a terminal portion of the inductance element according to the embodiment of the present invention.

FIG. 14 is a perspective view showing a wireless terminal device according to one embodiment of the present invention;

FIG. 15 is a block diagram showing a wireless terminal device according to one embodiment of the present invention;

FIG. 16 is a side view showing a conventional inductance element.

[Explanation of symbols]

 Reference Signs List 11 base 11a central part 11b, 11c end part 11d, 11e, 11f corner part 12 conductive film 13 groove 14 protective material 15, 16 terminal part 30 speaker 31 operation part 32 display part 33 antenna 34 transmission part 35 reception part 36 control part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Iso Saki Kenzo 1006 Ojidoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-58-79706 (JP, A) JP-A Sho-59-208707 (JP, A) JP-B Sho 62-8924 (JP, B2)

Claims (8)

(57) [Claims] A base, a conductive film formed on the base, a groove provided in the conductive film and the base, and a protective material provided to cover the groove. Insulation element and magnetic material
And the protective material in the groove provided in the base along with the impart a magnetic to the protective material provided, than inside of the protective material
An inductance element characterized in that the ratio of the insulating material is higher on the outer side . 2. The inductance element according to claim 1, wherein the electric resistance of the protective material is set to 10 ⁷ cmΩ or more. 3. The inductance element according to claim 1, wherein a protective material is used in which a magnetic material is mixed with an insulating material made of at least one of resin and glass. 4. The inductance element according to claim 3, wherein an oxide magnetic material is used as the magnetic material. 5. The inductance element according to claim 4, wherein ferrite is used as the oxide magnetic material. 6. The inductance element according to claim 3, wherein the proportion of the insulating material is not more than 20% by weight. 7. An average particle size of the pulverized particles of the magnetic material is from 0.1 to 0.1.
The inductance element according to claim 3, wherein the inductance element is 10 μm. 8. The inductance element according to claim 1-7, wherein the further by providing the insulating material layer on the protective material. "