KR101743989B1

KR101743989B1 - Elastic composite filter

Info

Publication number: KR101743989B1
Application number: KR1020150154846A
Authority: KR
Inventors: 김선기
Original assignee: 조인셋 주식회사
Priority date: 2015-10-23
Filing date: 2015-11-05
Publication date: 2017-06-07
Also published as: KR20170048109A

Abstract

A technique is disclosed in which a composite filter having elasticity is provided with a capacitor to remove noise. The composite filter includes at least an elastic core, a first electrically conductive layer bonded to cover the core, a polymer dielectric layer wrapped around the first electrically conductive layer to expose at least a lower surface of the first electrically conductive layer, And a second electrically conductive layer wrapped and bonded to cover the upper surface.

Description

[0001] The present invention relates to a composite filter having elasticity,

Field of the Invention The present invention relates to a composite filter, and more particularly, to a technique for eliminating noise by providing a capacitor elastically in contact with one of the objects interposed between electrically conductive objects.

An electrical connection terminal having elasticity is used for electrically connecting a conductive object such as an antenna or a metal case to a conductive pattern of a circuit board or for electrically connecting to a ground for eliminating static electricity or electromagnetic interference (EMI).

The electrical connection terminal may be soldered to the conductive pattern of the circuit board and fixed or used between the objects.

When these electric connection terminals are used to connect electric power in the vertical direction, the working distance is large in the vertical direction as possible so as to accommodate the dimensional tolerance in the vertical direction of the electrically conductive object to be electrically connected while the electric resistance is small, And structures and materials having good elastic restoring force are required.

Examples of such elastic electrical connection terminals include Korean Patent Registration Nos. 1001354 and 1381127 by the present applicant.

However, these electrical connection terminals have a role of elastically and electrically connecting opposing objects interposed between the electrically conductive objects, but they do not have a function of removing noise from which the electrical connection terminals themselves are introduced.

Generally, noise consists of conduction noise propagated through a signal line or a power line, induction noise propagating through an electromagnetic induction or an electrostatic induction, and radiation noise propagating in the form of electromagnetic waves .

Conventional capacitors are mounted on a printed circuit board and are not resilient, so that they are difficult to mount between electrically conductive objects and also do not elastically contact with a working distance, There is a great risk of being damaged by impact.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a composite filter having elasticity and having a capacitor and having a noise removing function.

Another object of the present invention is to provide a composite filter which is easy to manufacture and install and which is economical.

Another object of the present invention is to provide a composite filter having a large working distance, good elasticity and elastic restoration rate, and little influence on the change in capacitance even when pressed by an object.

Another object of the present invention is to provide a composite filter that is easy to mount and solderable.

The above object is achieved by an elastic core comprising: an elastic core; A first electrically conductive layer wrapped around the core; A dielectric layer made of a polymer or a rubber material to cover and bond the first electrically conductive layer to expose at least a lower surface of the first electrically conductive layer; And a second electrically conductive layer wrapped and bonded to cover at least the upper surface of the dielectric layer, wherein the first and second electrically conductive layers are each used as an electrode and form a capacitor together with the dielectric layer, Wherein the elastic material is used by being pressed by the pressing of the object between the electrically conductive objects which are made of the elastic material.

The above object is achieved by an elastic core having an electrically conductive outer surface; A dielectric layer that covers the core and is bonded to expose at least the lower surface of the core; And an electrically conductive layer wrapped and bonded to cover at least the upper surface of the dielectric layer, wherein the core and the electrically conductive layer are each used as an electrode, together with the dielectric layer constitutes a capacitor, And is pressed by the pressure of the object between the first filter and the second filter.

The above object is achieved by an elastic core comprising: an elastic core; An electrically conductive first rubber coating layer wrapped around the core; An insulating rubber coating layer wrapped around the first rubber coating layer so that at least the lower surface of the first rubber coating layer is exposed; And an electrically conductive second rubber coating layer wrapped and bonded to cover at least the upper surface of the insulating rubber coating layer, wherein the first and second rubber coating layers are used as electrodes, constitute a capacitor together with the insulating rubber coating layer, And the elastic core is pressed and used by the pressing of the object between the opposing electrically conductive objects.

According to the above configuration, the composite filter is provided with a capacitance suitable for elasticity and noise elimination that provide opposed working distances, thereby eliminating noise that flows in and out of contact with the opposing electrically conductive object with elasticity.

Also, it is easy to mount to any one of the electrically conductive objects which are sandwiched between the electrically conductive objects or opposed to each other by double-sided electroconductive adhesive tape or soldering.

In addition, a tubular rubber or an open cell foamed rubber is applied as an elastic core, so that the elasticity and the elastic recovery are good.

Further, even when the composite filter is pressed by the object, there is no change in the distance between the electrodes having a small electric resistance, so that the change in the capacitance of the composite filter is not greatly affected.

1 is a perspective view illustrating a composite filter according to an embodiment of the present invention.
Fig. 2 is a cross-sectional view taken along AA of Fig.
Figure 3 shows the use of a composite filter.
4 is a cross-sectional view illustrating a composite filter according to another embodiment of the present invention.
5 is a cross-sectional view illustrating a composite filter according to another embodiment of the present invention.

It is noted that the technical terms used in the present invention are used only to describe specific embodiments and are not intended to limit the present invention. In addition, the technical terms used in the present invention should be construed in a sense generally understood by a person having ordinary skill in the art to which the present invention belongs, unless otherwise defined in the present invention, Should not be construed as interpreted or interpreted in an excessively reduced sense. In addition, when a technical term used in the present invention is an erroneous technical term that does not accurately express the concept of the present invention, it should be understood that technical terms can be understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted according to a predefined or prior context, and should not be construed as being excessively reduced.

Furthermore, the singular expressions used in the present invention include plural expressions unless the context clearly dictates otherwise. In the present invention, the terms such as " comprises " or " comprising " and the like should not be construed as encompassing various elements or various steps of the invention, Or may further include additional components or steps.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a composite filter according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A-A in FIG.

The composite filter 100 includes an elastic core 110 and an electrically conductive layer 130 wrapped around the core 110 with the adhesive layer 120 interposed therebetween. A dielectric layer 140 made of a polymer material which is wrapped around the dielectric layer 130 and an electrically conductive layer 150 wrapped and bonded to cover at least the upper surface of the dielectric layer 140.

In this embodiment, the surface area of the electrically conductive layer 130 is formed to be larger than the surface area of the electrically conductive layer 150 due to the nature of the structure.

Here, the adhesion is used to mean both adhesion and adhesion, and may be broadly interpreted to include physical bonding.

At least the lower surface of the electrically conductive layer 130 is exposed to solder by the solder cream through the exposed bottom surface.

In this embodiment, the lower surface of the conductive layer 130 and the portions 132 corresponding to both corners thereof are exposed to the outside. As will be described later, in this portion 132, an electrically conductive object, And the dielectric layer 140 is formed only up to the boundary of the exposed portions at both corners.

As described later, since the area of the electrically conductive layer 150 is smaller than that of the electrically conductive layer 130, it is applied to determine the area of the counter electrode that calculates the magnitude of the capacitance. In this embodiment, But it is not limited thereto and may be formed to have the same area as the dielectric layer 140 at the maximum.

The dimensions of the composite filter 100 are not limited. For example, the composite filter 100 may have a width of 1 mm to 3 mm, a length of 1 mm to 10 mm, a height of 0.5 mm to 2.0 mm, a capacitance, .

The capacitance, which is the capacitance of the capacitor formed by the dielectric layer 140 interposed between the conductive layers 130 and 150, is not limited, but may be a value that facilitates removing noise corresponding to a related frequency. For example, it may be a capacitance of 2 to 50 pF for an LTE band and the like, but is not limited thereto.

For example, the capacitance may be a dimension that can attenuate unwanted noise, such as unwanted static electricity or an electrical shock through ground.

The compression ratio of the composite filter 100 by the core 110 may be 25% or more of the original height, and the elastic restoration ratio after pressing may be maintained at 90% or more.

The core 110 serves to provide elasticity and elastic restoring force of the composite filter 100, such as tubular insulation, electrically conductive or semi-conductive rubber, or a foam rubber such as a sponge, as in this embodiment.

The electrically conductive layers 130 and 150 may be a metal foil such as a copper foil, a plated electroconductive fiber, a polymer film having a metal layer formed on its outer surface, or an electrically conductive polymer coating layer, wherein the polymer comprises rubber, Silicone rubber coating layer.

When the conductive layers 130 and 150 are formed of a metal foil or a polymer film having a metal layer formed thereon, a metal foil or a metal layer may be plated with tin, silver, nickel, gold or the like, or an electrically conductive polymer resin having a low electrical resistance may be coated Corrosion can be prevented.

When the conductive layers 130 and 150 are formed of a metal foil, a plated electroconductive fiber, or a polymer film having a metal layer formed on the outer surface thereof, a separate adhesive may be applied to each of the dielectric layers 140. As the adhesive, May be applied. When the electrically conductive layers 130 and 150 are electrically conductive polymer coating layers, they may be integrally bonded to the lower surface and the upper surface of the dielectric layer 140, for example, by casting to form a unitary body.

When the conductive layer 130 is electrically conductive, the adhesive layer 120 may not be extended to the lower surface of the elastic core 110, but the lower surface of the elastic core 110 may be flattened to attach the metal foil .

The dielectric layer 140 is electrically insulated. The dielectric layer 140 is made mainly of BaTiO ₃ , such as Y5V (capacitance change with temperature change) of about 18,000 or X7R (capacitance change with temperature change) having a dielectric constant of about 3,000 It can be a hardened dielectric sheet mixed with high dielectric ceramics powder. Because it is flexible, it is well bent and hardness is low, so it is easy to cut such as cutting a blade.

For example, the dielectric layer 140 may be formed of an insulating polymer film or an insulating polymer coating layer or an insulating polymer film having an insulating polymer coating layer. In this case, the conductive layer 130 or 150 may be formed on the upper surface of the insulating polymer film And a metal foil or an electrically conductive coating layer integrally formed on the lower surface.

Since all the other constituent parts except for the dielectric layer 140 have a much lower dielectric constant than the dielectric layer 140, the dielectric constant of the dielectric layer 140, together with the spacing between the electrically conductive layers 130 and 150, The capacitance is mainly determined.

Specifically, the capacitance of the composite filter 100 is calculated by the following equation (1).

Here, S is the facing area of the conductive layers 130 and 150, d is the distance between the horizontal conductive layers 130 and 150, and? Is the relative dielectric constant of the material constituting the dielectric layer 140.

Accordingly, the capacitance of the composite filter 100 is proportional to the opposed area of the electrically conductive layers 130 and 150 used as the electrodes, the relative dielectric constant of the dielectric layer 140 is proportional to the distance between the electrically conductive layers 130 and 150 Inversely. Here, since the areas of the electrically conductive layers 130 and 150 are different, the opposite area is determined by the electrically conductive layer 150 having a small area.

Figure 3 shows the use of a composite filter.

3, the composite filter 100 is interposed between an electrically conductive object such as a metal case 20 and a circuit board 10 to elastically connect them together. The composite filter 100 has a Reel Taping And then surface mounted so that the portion 132 of the electrically conductive layer 130 is soldered to the circuit board 10 by reflow soldering with a solder cream.

The electrically conductive layer 150 is in contact with the metal case 20 and the electrically conductive layer portion 132 is in contact with and soldered to the electrically conductive pattern 12 of the circuit board 10, 150 by a dielectric layer 140 interposed between them.

As a result, noise flowing through any one of the conductive layers 130 and 150 due to the capacitance of the composite filter 100 can be attenuated or blocked by the other. For example, the high-frequency noise introduced from the metal case 20 is blocked by the composite filter 100 and does not flow into the circuit board 10. [

Conversely, when the capacitance of the composite filter 100 is set to correspond to another related frequency, e.g., a low frequency, the low frequency noise introduced through the conductive layer 150 is transmitted through the conductive layer portion 132 to the circuit board 10, As shown in FIG.

The meaning of the high frequency and the low frequency used in the present invention is a relative concept that can be determined according to the use of the composite filter 100. For example, in a smartphone, a high frequency means about 30 MHz or more, But it is not limited to this.

Therefore, since the noise removed or suppressed by the capacitance of the composite filter 100 is different, the capacitance can be set in consideration of the frequency and the size of the noise to be removed.

The tolerance of the capacitance of the composite filter 100, that is, the variation of the capacitance of the composite filter 100 when the composite filter 100 is pressed to the maximum and the minimum, may be within ± 30%, but is not limited thereto.

When the composite filter 100 is pressed between the metal case 20 and the circuit board 10, the core 110 is pressed but the gap between the conductive layers 130 and 150 is not changed. As a result, 1, the change of the capacitance of the composite filter 100 is not large.

As in this embodiment, although the electrically conductive layer portion 132 can be effectively utilized by soldering to the elastic and resilient restoring forces of the core 110 by being fixedly mounted to the electrically conductive object, such as the circuit board 10, And the electrically conductive layer 130 is adhered to the electrically conductive object by the double-sided electroconductive adhesive tape, or the composite filter 100 is forcibly sandwiched between the electrically conductive objects, which will be described in the following embodiments .

For the soldering of the composite filter 100, the dielectric layer 140 and the core 110 need to have heat resistance enough to satisfy the soldering condition by the solder cream.

Although not shown, a reinforcing layer or an adhesive layer of an insulating material may be interposed between the dielectric layer 140 and the electrically conductive layer 130 or between the dielectric layer 140 and the electrically conductive layer 150, or between them.

The reinforcing layer serves to strengthen the mechanical strength of the composite filter 100 and to adhere the dielectric layer 140 and the conductive layers 130 and 150 to each other.

For example, in the case where the electrically conductive layer 150 exposed to the outside is made of a metal foil, the surface of the electrically conductive layer 150 is scratched because the reinforcing layer supports the exposed surface of the electrically conductive layer 150, .

The reinforcing layer may be composed of an insulating polymer film such as polyimide (PI) or polyester (PET), a fiber, or a composite insulating circuit board such as FR-4.

For example, when the metal layer is integrally formed on the lower surface of the circuit board, the reinforcing layer may be composed of a composite insulating circuit board. In this case, the metal layer serves as the conductive layer 130, .

4 shows a composite filter according to another embodiment of the present invention.

In this embodiment, the same reference numerals as in the embodiment are assigned to the same components.

In this embodiment, at least the outer surface of the elastic core 210 is electrically conductive, and the lower surface and both corners thereof are exposed to the outside.

Thus, the elastic core may be, for example, a rubber having an outer metal layer formed thereon.

The dielectric layer 240 made of polymer or rubber is bonded to the outer surface of the core 210 through the adhesive layer 220 and the electrically conductive layer 250 is adhered to the upper surface of the dielectric layer 240 and both corners thereof.

Here, the adhesive layer 220 may be insulated or electrically conductive, and there is only a difference in contributing to the determination of the capacitance.

The core 210 serves as one electrode of the capacitor constituting the composite filter 200 and serves to provide an elastic and elastic restoring force. The core 210 may be a tube-shaped rubber or an open- .

In the case of the composite filter 200 according to this embodiment, soldering with the solder cream is not possible, but when the conductive layer 250 contacts one electrically conductive object and the core 210 contacts another electrically conductive object A capacitor composed of an electrically conductive layer 250, a dielectric layer 240, and a core 210 with elasticity is formed.

If necessary, an electrically conductive double-sided adhesive tape may be applied to the upper surface of the conductive layer 250 and the lower surface of the core 210.

5 shows a composite filter according to another embodiment of the present invention.

In this embodiment, the elastic core 310 may be insulative or electrically conductive.

The entire outer surface of the core 310 is surrounded by the first electrically conductive rubber coating layer 330 and is surrounded by the insulating rubber coating layer 340 which is a dielectric layer except the lower surface of the electrically conductive rubber coating layer 330 and both edges thereof, The electrically conductive second rubber coating layer 350 is wrapped on the upper surface of the insulating rubber coating layer 340 and both corners thereof.

The core 210 serves to provide elasticity and elastic restoring force of the composite filter 300. The core 210 may be a tube-shaped rubber or an open-cell foamed rubber. If the rubber is a rubber, the composite filter 300 may be a single rubber material .

In the case of the composite filter 300 according to this embodiment, the second rubber coating layer 350 is in contact with one electrically conductive object and the first rubber coating layer 330 is in contact with another electrically conductive material A capacitor composed of the second rubber coating layer 350, the insulating rubber coating layer 340, and the first rubber coating layer 330 is formed with elasticity by contacting the object.

If necessary, an electrically conductive double-faced adhesive tape may be applied to the upper surface of the second rubber coating layer 350 and the lower surface of the first rubber coating layer 330.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100, 200, 300: Compound filter
110, 210, 310: elastic core
120, 220: adhesive layer
130, 150, 250: electrically conductive layer
140, 240: dielectric layer
330, 350: electrically conductive rubber coating layer
340: insulated rubber coating layer

Claims

A composite filter interposed between opposing electrically conductive objects,
Elastic core;
A first electrically conductive layer wrapped around the core;
A dielectric layer made of a polymer or rubber material, the dielectric layer being wrapped around the first conductive layer so that a part of the first conductive layer is exposed; And
And a second electrically conductive layer wrapped and bonded to cover at least the upper surface of the dielectric layer,
The first and second electrically conductive layers are used as electrodes, respectively, to form a capacitor together with the dielectric layer,
Wherein the exposed first electrically conductive layer is soldered to one of the electrically conductive objects by a solder cream,
Wherein the elastic core is pressed by the pressure of the other one of the electrically conductive objects.

In claim 1,
Wherein the surface area of the first electrically conductive layer is larger than the surface area of the second electrically conductive layer.

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In claim 1,
Wherein the first and second electrically conductive layers are a metal foil, a plated electroconductive fiber, a polymer film having a metal layer formed on an outer surface thereof, or an electrically conductive polymer coating layer.

In claim 5,
When the first and second electrically conductive layers are made of a metal foil, a plated electroconductive fiber, or a polymer film having a metal layer formed on the outer surface thereof, a separate adhesive is applied to the dielectric layer and the first and second electrically conductive layers Wherein the dielectric layer is integrally bonded to the lower surface of the dielectric layer by casting in the case of a polymer coating layer.

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