JPH11154612A - Electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component in high conformability and reliability easy to be manufactured at low cost. SOLUTION: In an electronic component, thickness of a topmost insulating layer 12d among the insulating layers comprising a circuit element wherein conductor pattern layers 13a, 13b, 13c, 13d and insulating layers 12a, 12b, 12c and 12d are laminated on an insulating substrate 11 is specified to exceed two times of the maximum thickness of the conductor pattern layers. The insulating layer 12a in the thickness exceeding five times of the surface roughness Ra (mean roughness of central line) is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electronic component,
In particular, an inductor (L) suitable for use on a surface mount board,
The present invention relates to a single element component such as a capacitor (C) and a resistance element (R), and a composite element component such as an EMI filter, a common mode choke coil, a current sensor, and a signal transformer.

[0002]

2. Description of the Related Art A partial cross-sectional view of an example of a conventional electronic component is shown in FIG.
As shown in FIG. As shown in FIG. 4, a conventional electronic component is formed on a substrate 101 by sputtering or the like.
Conductor pattern 1 made of i, Ti-Ag, or Ag
03 and insulating layers 102 made of polyimide resin or the like are alternately laminated to form the circuit element 100. In general, a plurality of circuit elements 100 are formed on a single substrate made of an insulating substrate by arranging them vertically and horizontally, and then cut and divided to obtain circuit elements formed into chips.

Further, at the end of the conductor pattern 103,
An electronic component is formed by forming a base electrode 14 extending from the upper end of the chip to the lower end of the chip via the side surface of the chip and forming the external electrode 15.

[0004]

However, since the circuit element is damaged by external mechanical stress, the non-defective rate in the process after the circuit element is formed into a chip is low.

When an electronic component is used in an atmosphere of high humidity, migration occurs in a conductor pattern due to moisture absorption of an insulating (resin) layer, thereby deteriorating the dielectric strength of the electronic component and reducing the reliability of equipment. Sex was reduced.
In addition, a part of the uppermost insulating layer may be peeled off in the process, and a part of the conductor pattern may be exposed.

Further, when a conductor pattern is laminated using an insulating substrate having a surface roughness Ra of about 1 μm, irregularities are generated in the formed conductor pattern layer due to the influence of the surface roughness. ) Deterioration of the mask and occurrence of an abnormal appearance product of the conductor pattern layer were caused.

Further, when monitoring the shape, the shape cannot be clearly distinguished due to the unevenness due to the surface roughness of the insulating substrate, and there is a concern about the quality judgment in the process. Therefore, although the cost of the insulating substrate to be used is increased, mirror processing is performed to reduce the surface roughness Ra of the insulating substrate to 0.1.
It was necessary to be 1 μm or less.

It is an object of the present invention to provide an electronic component which is easy to manufacture, inexpensive, has a high yield rate, and has high reliability.

[0009]

The present invention relates to an electronic component comprising a circuit element formed by laminating at least one conductive pattern layer and at least one insulating layer on an insulating substrate. An electronic component in which the thickness of the uppermost insulating layer (of the insulating layers) is at least twice the maximum thickness of the conductor pattern layer.

Further, the present invention is the above electronic component, wherein the insulating layer in contact with the insulating substrate has a thickness of at least five times the surface roughness Ra (center line average roughness) of the insulating substrate.

That is, according to the present invention, a circuit element is formed by laminating at least one or more conductor pattern layers and one or more insulating layers on an insulating substrate by using a thin film process. An electronic component provided with, the thickness of the insulating layer to be the uppermost layer, the spin coating conditions lower rotation,
An electronic component in which the number of layers is increased to more than twice the maximum thickness of the conductor pattern layer of the circuit element.

Further, in order to stabilize the thin film laminating process and reduce the cost, the substrate to be used is an insulative substrate having a substrate roughness Ra of 1 μm level, which is not mirror-finished, and the lowermost layer of the thin film laminating process is formed of an insulating layer. And an electronic component in which the thickness of the insulating layer is at least five times the surface roughness Ra of the insulating substrate.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below using an EMI filter as an example of an electronic component of the present invention.

FIG. 1 is a partial sectional view of the electronic component of the present invention, FIG. 2 is a perspective view showing the electronic component of FIG. 1, and FIG. 3 is an exploded view schematically showing the structure of the circuit element. It is a perspective view.

As shown in FIG. 1, the electronic component of the present invention comprises:
An insulating layer 12a is provided in contact with the insulating substrate 11, and the insulating layer 1
2a, a conductor pattern layer 13a is laminated thereon, and
The insulating layer 12b is laminated, the conductor pattern layer 13b is laminated on the insulating layer 12b, the insulating layer 12c is laminated thereon, the conductor pattern layer 13c is laminated on the insulating layer 12c, and further thereon. , An insulating layer 12d and an insulating layer 1
A conductor pattern layer 13d is laminated on 2d.

A base electrode 14 is provided in contact with the conductor pattern layer 13d, and external electrode films 15a and 15b are provided thereon. Since the external electrode film 15b is formed so as to cover both end surfaces and a part of the side surface of the circuit element 21 on the insulating substrate 11, it functions as the external electrode terminal portion 22 of the electronic component (EMI filter) 10 (FIG. 2). In FIG. 2,
Since the insulating layer used in the present embodiment has transparency, the conductor pattern layer can be seen through the insulating layer.

For the formation of the base electrode 14, a conductive paste made of an epoxy resin or the like containing a metal powder such as Ni and effective for product reliability was used. The external electrode film 1 is formed using an electrolytic barrel plating method, which is an effective means in the manufacturing process.
5a is a Ni film, and 15b is a solder film.

Then, as shown in FIG. 3, the circuit element 21 of the EMI filter is
a, 12b, 12c, 12d and the conductor pattern layer 13a,
The circuit is formed by laminating 13b, 13c, 13d, and one circuit is constituted by the conductor pattern layer 13a, and the conductor pattern layers 13b and 13c are formed through holes (not shown) provided in the insulating layer 12c. Are connected to each other to form one circuit, and as a whole, are constituted by two circuits (two coils) opposed to each other with the insulating layer 12b interposed therebetween. The conductor pattern layer 13d
Is provided to ensure connection with external electrodes.

The insulating substrate 11 has a surface roughness Ra.
An inexpensive substrate having a surface roughness Ra of the order of 1 μm, which was not subjected to mirror finishing of 0.1 μm or less, was used. Then, the thickness of the insulating layer 12a in contact with the insulating substrate 11 was set to five times the surface roughness Ra (1 μm) of the insulating substrate 11.

The insulating layers 12a, 12b, 12
For c and 12d, a benzocyclobutene resin is used, and the thickness of the uppermost insulating layer 12d is
The maximum thickness of a, 13b, 13c, and 13d is twice as large. In order to control the thickness of the insulating layer, the number of layers was increased and spin coating conditions were controlled.

The conductor pattern layers 13a, 13b, 1
3c and 13d were formed by forming a base film of Ti and Cu by sputtering or the like, forming a pattern with a resist, and electrodepositing a Cu film by electrolytic plating.

The EMI filter, which is an electronic component of the present invention, obtained as described above, has less damage to circuit elements due to external mechanical stress, improves the non-defective rate, and
Even when used in high humidity, the occurrence of migration of the conductor pattern layer due to moisture absorption of the insulating layer is significantly reduced, and high quality,
It became a highly reliable electronic component.

Further, even when a substrate having a surface roughness Ra of 1 μm level is used, the deterioration of the PR mask and the occurrence of abnormal shape of the conductor pattern layer in the thin film laminating process are reduced, and the quality is judged in the process. Thus, stable and inexpensive electronic components could be manufactured.

When the thickness of the uppermost insulating layer is less than twice the maximum thickness of the conductor pattern layer, a part of the insulating layer is peeled off in the process, and a part of the conductor pattern is removed. Some of them were exposed, and the occurrence of abnormal appearance products could not be suppressed.

Further, the lowermost layer of the thin film laminating process is used as an insulating layer, and the thickness of the insulating layer is set to a value equal to the surface roughness Ra of the insulating substrate.
When it is less than twice, the occurrence of unevenness due to the effect of the roughness Ra of the insulating substrate could not be completely suppressed.
R) The deterioration of the mask and the occurrence of abnormal appearance products of the conductor pattern layer could not be suppressed.

In the embodiment of the present invention, an EMI filter has been exemplified as an electronic component. However, a single element component such as an inductor (L), a capacitor (C), a resistance element (R), a common mode choke coil, etc. Even when used for electronic components (surface-mounted components, lead components) such as composite device components such as current sensors and signal transformers, and their circuit elements, their effects remain unchanged.

Further, in the description of the present embodiment, the insulation made of benzocyclobutene resin is used. However, if an insulating material capable of forming a thin film is used, the effect is the same regardless of what kind of insulating material is used. .

[0028]

According to the present invention, it is easy and inexpensive to manufacture,
An electronic component with a high non-defective rate and high reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of an electronic component according to the present invention.

FIG. 2 is a perspective view showing an electronic component of the present invention.

FIG. 3 is an exploded perspective view schematically showing a configuration of a circuit element of the electronic component of the present invention.

FIG. 4 is a partial cross-sectional view of an example of a conventional electronic component.

[Explanation of symbols]

10 Electronic component (of the present invention) 11 Insulating substrate 12a, 12b, 12c, 12d (used for the electronic component of the present invention) Insulating layer 13a, 13b, 13c, 13d (used for the electronic component of the present invention) Pattern layer 14 base electrode 15 external electrode 15a, 15b external electrode film 21 circuit element 22 external electrode terminal part 100 (conventional) electronic component 101 (used for conventional electronic component) insulating substrate 102 Insulating layer 103 (used for conventional electronic components) Conductor pattern (used for conventional electronic components)

Claims (2)

[Claims] An electronic component comprising a circuit element formed by laminating at least one conductive pattern layer and at least one insulating layer on an insulating substrate, wherein the thickness of the uppermost insulating layer is Electronic component, which is not less than twice the maximum thickness of the conductor pattern layer. 2. An electronic component comprising a circuit element by laminating at least one conductor pattern layer and at least one insulating layer on an insulating substrate, wherein the insulating layer in contact with the insulating substrate is An electronic component having a thickness of at least five times the surface roughness Ra of the insulating substrate.