KR101022355B1 - Composite gasket for shielding electromagnetic wave and sealing electronic device, and electronic device comprising the same - Google Patents

Abstract

PURPOSE: A composite gasket for shielding electromagnetic wave and sealing an electronic device and an electronic device comprising the same are provided to protect an electronic device from moisture by preventing the inflow of exterior air into the device. CONSTITUTION: A composite gasket for shielding electromagnetic wave and sealing an electronic device comprises a first gasket(10) and a second gasket(20). The first gasket is made of an elastic material with a domed top and hollow interior. The second gasket is made of a conductive elastic material in which conductive powder is uniformly dispersed in an elastic body, and the second gasket is joined to a side of the first gasket.

Description

Composite gasket for shielding electromagnetic wave and sealing electronic device, and electronic device comprising the same}

The present invention relates to a composite gasket for electromagnetic shielding and housing sealing, and an electronic device including the same, and more particularly, to effectively block electromagnetic waves generated from the inside of the electronic device from being discharged to the outside, and to prevent outside air into the electronic device. The present invention relates to a composite gasket for electromagnetic shielding and sealing of electronic devices, which prevents the inflow, maintains waterproofness and airtightness, and minimizes the decrease in efficacy due to outside air, and an electronic device including the same.

With the advent of the knowledge and information society in the 21st century, the rapid development of wireless information communication technology using radio waves is taking place. Electromagnetic waves are a key element of such wireless information and communication technology, and are emerging as essential elements in daily life. Electromagnetic wave is a form of energy generated by the use of electricity. It is a synthetic wave of electric field and magnetic field. The electric field is shielded by all conductive objects, but the magnetic field has strong permeability through all objects. Magnetic fields are known to have harmful effects on the human body.

These electromagnetic waves are emitted from electrical appliances and power lines such as home appliances, wireless communication systems, control systems, power systems, high frequency equipment, and lighting equipment that are used around us. There is a great possibility of power generation, and electromagnetic interference is frequently occurring with the development of electronic devices including digitalization of computers and facsimiles. In other words, electromagnetic waves are emitted from the electronic devices in use around us. Among them, when the human body is exposed to very low and low frequencies for a long time, it is likely that biological rhythms will break down with body temperature and develop into diseases. Has a very weak radio wave, but it affects the distribution of ions such as calcium, potassium, sodium, and chlorine that move cell membranes in the human body, causing hormonal abnormal secretion. High-frequency microwaves cause water molecules inside food to fluctuate As the temperature increases, the function of the nervous system is affected by electrical and chemical changes in the body, so very high frequencies can cause stress, heart disease, chemical changes in the blood, and in severe cases, brain tumors. Many researches about the harmfulness of electromagnetic waves have been published. In addition, electromagnetic waves also affect the machine, affecting the electronic circuits of other electronic devices, causing malfunctions.

In electronic devices (e.g. radars) in which electronic circuits and electronic components are housed, water or dust from the outside penetrates through gaps between the lower case and the upper case (e.g., cover), Another problem arises that adversely affects other parts. For this reason, a method is usually employed between the lower case and the upper case (for example, a cover) to prevent the ingress of water and dust from the outside. However, since the gasket is inserted in this way, a gap is formed between the lower case and the upper case (for example, a cover), which causes a problem that electromagnetic waves leak from the gap.

As a countermeasure, electroconductive rubber gaskets are used abundantly. In this case, the conductive rubber is a conductive metal powder dispersed as a filler in the rubber. In general, the conductive rubber gasket seals the inside of the electronic device and is exposed to the external environment at the same time. When the conductive rubber gasket is exposed to an external environment such as water, steam, and brine for a long time, the conductive metal powder is oxidized or corroded, and the rubber Deteriorates due to deterioration of elasticity, which causes problems such as deterioration of durability as a gasket and a significant drop in electromagnetic shielding efficiency.

Therefore, even if it is exposed to external environment such as water, steam, salt water for a long time, electromagnetic shielding efficiency does not decrease, and it prevents the inflow of external air such as water and dust into the electronic device, and develops a gasket that can be used for a long time with excellent durability. Is required.

The present invention is derived to solve the conventional problems, one object of the present invention is to maintain the electromagnetic shielding efficiency reliably even if exposed to external environment such as water, steam, salt water for a long time, the outside air is introduced into the electronic device It is to provide a composite gasket for electromagnetic shielding and sealing the electronic device to prevent water to maintain waterproof and airtight, and to minimize the decrease in efficacy by the outside air.

Another object of the present invention is to provide an electronic device to which the gasket according to the present invention is applied.

In order to solve the object of the present invention, the present invention is inserted between the upper housing, a portion of the surface is conductive and the lower housing, a portion of the surface, so that electromagnetic waves generated inside the electronic device to the outside of the electronic device A gasket for preventing the outside from being introduced into the electronic device, the gasket comprising: a first gasket having a hollow inside as a continuum and made of an elastomer; And a second gasket joined to one side of the first gasket as a continuum and integrated with each other, the second gasket made of a conductive elastic body. In this case, the conductive elastic body is preferably characterized in that the conductive powder is a composition uniformly dispersed in the elastic body, more preferably, the volume ratio of the conductive powder: elastic body is characterized in that 1: 4 ~ 7: 3.

In order to solve the other object of the present invention, the present invention is a part of the upper housing is conductive; A lower housing wherein a portion of the surface is conductive; And a composite gasket according to the present invention, wherein the composite gasket is inserted between the upper lower housing and the lower housing to seal the upper housing and the lower housing. In this case, the electronic device is preferably a radar.

Since the composite gasket according to the present invention integrates a second gasket for electromagnetic shielding and a first gasket for waterproofing and airtight, the second gasket is applied to the external environment by the first gasket. It is blocked. Therefore, the composite gasket according to the present invention maintains electromagnetic wave shielding efficiency reliably even when exposed to external environment such as water, steam, brine for a long time, minimizes the decrease in efficacy due to outside air, and prevents the inflow of outside air into the electronic device. To maintain the waterproof and airtightness of electronic devices.

1 is a cross-sectional view of a composite gasket according to a preferred embodiment of the present invention, Figure 2 shows a state in which the composite gasket according to a preferred embodiment of the present invention is applied to an electronic device.
3 is a cross-sectional view of a first extrusion mold for extruding a first gasket of a composite gasket according to a preferred embodiment of the present invention, Figure 4 is an extrusion of the second gasket of the composite gasket according to a preferred embodiment of the present invention Figure 2 is a cross-sectional view of the second extrusion mold, Figure 5 is a cross-sectional view of the composite extrusion mold to the final extrusion of the composite gasket according to a preferred embodiment of the present invention.

Hereinafter, preferred examples of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, detailed description is abbreviate | omitted when it is judged that it may obscure the summary of this invention. In addition, the following will describe a preferred example of the present invention, but the technical idea of the present invention is not limited thereto, but may be implemented by those skilled in the art.

1 is a cross-sectional view of a composite gasket according to a preferred embodiment of the present invention. As shown in FIG. 1, in the composite gasket according to the present invention, the first gasket 10 and the second gasket 20 are integrated.

First gasket 10

The first gasket is responsible for the waterproof and airtight functions of the electronic device. In addition, the first gasket prevents the second gasket from being exposed to an external environment such as water, steam, and brine. The first gasket 10 is a continuum having a hollow 11 therein, the shape of the hollow is similar to the outer shape of the first gasket, the size of the hollow can be adjusted so that the first gasket has a predetermined thickness. . Since the first gasket has a hollow structure inside, the shape of the first gasket is freely changed and the restoring force is excellent. Therefore, when applied between the case gap of the electronic device is in close contact between the gap, and effectively prevents water, dust, salt water, etc. flow into the electronic device through the gap.

The first gasket is made of an elastomer. The type of elastomer used is not particularly limited as long as it has an appropriate level of hardness and elasticity. Preferably, silicone rubber, ethylene propylene rubber (EPM), and ethylene propylene rubber are used. diene rubber (EPDM), styrene-butadiene rubber (SBR), chloroprene rubber (CR; neoprene), thermoplastic polyurethane, thermoplastic elastomer (TPE), and thermoplastic olefin ( Thermoplastic olefin, TPO) may be composed of one or more selected from the group consisting of. Thermoplastic elastomers (TPE) include styrene-butadiene-styrene rubber (Poly (styrene-butadiene-styrene), SBS Rubber) and the like. Silicone rubber is particularly preferable as the elastic body for forming the first gasket. The silicone rubber is excellent in heat resistance, weather resistance, and water repellency, and can maintain an appropriate rubber elasticity for a long time. In order for the first gasket of the composite gasket according to the present invention to exert its function extremely, it is most preferable that the elastic body, which is the material of the first gasket, is a silicone rubber having a hardness of 50 ± 5 according to the KSM 6511 test method.

As shown in FIG. 1, a second gasket is joined to one side of the first gasket, and a portion 12 of the first gasket joined to the second gasket has a shape protruding outwardly to facilitate the joining. It is desirable to have. In addition, it is preferable that the upper portion 13 of the first gasket has a dome shape, and the upper portion 13 of the first gasket has a dome shape. It can be sprayed and the final shape can be flat when the shape changes due to pressure. In addition, the first gasket is preferably characterized in that the lower end 14 of both sides has a wedge shape inclined outward. When the first gasket has a dove tail structure by the wedges at the lower sides of both sides as shown in FIG. 1, when the composite gasket is applied to an electronic device, the wedge acts as a locking jaw so that the upper housing (for example, Firmly attached to the inner surface of the cover). At this time, the inner surface of the upper housing which is bound with the wedge of the first gasket is formed with a groove, both ends of the groove has a reverse shape of the wedge (see Fig. 2). If the upper housing is made of a metallic material, the groove may be formed through mechanical processing, and if the upper housing is made of a material such as plastic, the groove may be formed through a mold in the injection molding step.

2nd Gasket (20)

The second gasket is responsible for the electromagnetic shielding function. The second gasket 20 is a continuous body having the same length as the first gasket, and is joined to and integrated with one side of the first gasket. In the composite gasket according to the present invention, since the first gasket for waterproofing and airtightness and the second gasket for electromagnetic wave shielding are integrated, electromagnetic wave shielding, waterproofing and airtightness of the electronic device can be simultaneously achieved by simple installation. In particular, since the second gasket is protected from outside air by the first gasket, the durability and reliability of the electromagnetic shielding performance are excellent.

The second gasket is made of a conductive elastomer. The conductive elastic body means a material having conductivity and appropriate hardness and elasticity, and specifically, has a form of a composition in which conductive powder is uniformly dispersed in the elastic body. At this time, the volume ratio of the conductive powder to the elastic body is not particularly limited, but is preferably 1: 4 to 7: 3, and more preferably 2: 3 to 3: 2, but the volume ratio of the conductive powder to the elastic body is 1: 4. If less than, it may not have an appropriate level of conductivity, and if the volume ratio of the conductive powder to the elastomer exceeds 7: 3, the amount of the elastomer serving as a matrix for uniformly dispersing the conductive powder is conditionally small so that The manufacture of the second gasket may not be smooth, and the second gasket may not have an appropriate level of elasticity. The conductive powder is not limited in kind, but considering the economics, versatility, conductivity, and the like, gold, silver, copper, aluminum, nickel, silver coated copper, silver coated nickel, nickel coated copper, and expanded graphite It is preferable that it consists of 1 or more types chosen from the group which consists of, and it is more preferable that it is especially copper coated with silver. The size of the conductive powder is also not limited, but considering the uniform degree of dispersion in the elastic body and the like, it is preferable that it is between several nanometers and several millimeters, especially between several micrometers and hundreds of micrometers. In addition, the elastic body constituting the second gasket may be selected from the elastic body constituting the first gasket. In particular, when the elastic body constituting the second gasket and the elastic body constituting the first gasket are made of the same material, the first gasket and the first gasket may be selected. Excellent adhesion between the two gaskets, smooth bonding, the composite gasket according to the present invention can be easily produced by extrusion molding. Since the content of the elastic body constituting the second gasket is the same as the content of the elastic body constituting the first gasket, description thereof is omitted.

2 illustrates a state in which a composite gasket according to an exemplary embodiment of the present invention is applied to an electronic device. Figure 2a shows a state before assembling the upper housing and the lower housing of the electronic device, b of Figure 2 shows a state of completing the assembly between the upper housing and the lower housing of the electronic device. As shown in FIG. 2, the electronic device includes an upper housing 110, a lower housing 120, and composite gaskets 130 and 140 according to the present invention. In electronics the upper housing generally serves as a cover.

The composite gasket according to the present invention is inserted between the upper housing and the lower housing to seal between the upper housing and the lower housing. More specifically, as shown in FIG. 2, the second gasket 140 of the composite gasket faces toward an inside of an electronic device in which an electronic component or an electronic circuit, which is an electromagnetic wave generation source, is formed, and the first gasket 130 of the composite gasket includes an electron. Facing the external environment of the device. At this time, at least a portion of the upper housing surface and at least a portion of the lower housing surface should be conductive to achieve electromagnetic shielding by the second gasket. That is, an electronic component or an electronic circuit which is an electromagnetic wave generating source is disposed in an inner space of the electronic device formed by a part of the surface of the conductive upper housing, a part of the surface of the conductive lower housing and the second gasket, and the internal space of the electronic device is physically And a part of the surface of the conductive upper housing surrounding the inner space, a part of the surface of the conductive lower housing and the second gasket are electrically connected to shield the electromagnetic wave.

The upper housing or the lower housing may be formed of a metal (for example aluminum), preferably a sandwich panel. In particular, when the upper housing or the lower housing is formed of a sandwich panel, the conductive layers 115 and 125 are laminated on one surface of the sandwich panel. The conductive layer may be a metal foil adhered by a conductive adhesive, or a known conductive paint. It may be formed by coating and drying.

In addition, since the first gasket 130 of the composite gasket according to an exemplary embodiment of the present invention has a dove tail structure as shown in FIG. 2, the first gasket 130 is firmly connected to an inner surface of the upper housing (eg, a cover). Is bound. In this case, a groove inverted from the dove tail structure is formed on the inner surface of the upper housing to stably accommodate the dove tail structure. In addition, a sealant is preferably applied around the first gasket stably received on the inner surface of the upper housing by the dovetail structure.

The composite gasket according to the present invention is applied to an electronic device in which an electronic circuit, an electronic component, and the like are accommodated. Electronic components are the basic electronic components of electronic devices. Typically packaged in conjunction with two or more leads or metal pads. Electronic components are soldered to printed circuit boards (PCBs) and connected to each other to operate with special functions such as amplifiers, receivers, and oscillators. Electronic components may also be packaged in a single device, such as resistors, capacitors, transistors, diodes, or integrated circuits such as op amps, array resistors, and logic circuits. The type of electronic device is not limited to a large number, and there are home appliances, wireless communication systems, control systems, power systems, high frequency equipment, lighting equipment, computers, medical diagnostic equipment, and the like. In particular, the composite gasket according to the present invention is preferably applied to the radar, because the radar used in military equipment such as ships, aircraft carriers can be easily exposed to external environments such as water, steam, dust, salt water for a long time.

Hereinafter, the manufacturing process of the composite gasket according to the preferred embodiment of the present invention will be described. 3 is a cross-sectional view of a first extrusion mold for extruding a first gasket of a composite gasket according to a preferred embodiment of the present invention, Figure 4 is an extrusion of the second gasket of the composite gasket according to a preferred embodiment of the present invention Figure 2 is a cross-sectional view of the second extrusion mold, Figure 5 is a cross-sectional view of the composite extrusion mold to the final extrusion of the composite gasket according to a preferred embodiment of the present invention.

The first gasket and the second gasket are respectively extruded using the first extrusion mold 200 shown in FIG. 3 and the second alloy mold 300 shown in FIG. More specifically, after melting the elastic body, a first gasket is obtained through the first extrusion mold. The first extrusion mold has an opening 210 corresponding to the outer shape of the first gasket as shown in FIG. 3. Further, after melting the composition in which the conductive powder is uniformly dispersed in the elastic body, a second gasket is obtained through the second extrusion mold. The second extrusion mold has an opening 310 corresponding to the outer shape of the second gasket as shown in FIG. 4. At this time, the first extrusion mold and the second extrusion mold are located in the adjacent forming line, the first gasket and the second gasket is extruded at the same time. At this time, the extrusion temperature of the first gasket and the second gasket is equal to or higher than the melting point of the elastic body used, and when the elastic body used in the first gasket and the elastic body used in the second gasket are the same material, the first gasket and the second gasket are extruded the same. Because of the extrusion at a temperature, the configuration and operation of the extruder can be simplified and the manufacturing process can be simplified. At the same time, the extruded first gasket and the second gasket are supplied to the compound extrusion mold, and the first gasket and the second gasket are joined in the compound extrusion mold. In more detail, as shown in FIG. 5, the composite extrusion mold 400 has an opening 410 corresponding to the outer shape of the composite gasket according to an exemplary embodiment of the present invention, and includes a first extrusion mold and a second extrusion mold. Is in direct contact with The opening of the composite extrusion mold has a cross-sectional area that is slightly larger than the cross-sectional area that combines the opening of the first extrusion mold and the opening of the second extrusion mold, and the second gasket passing through the first extrusion mold and the second extrusion mold. The gasket has a temperature close to the melting point, and when supplied to the composite extrusion mold, the pressure is released momentarily to expand. At this time, the first gasket and the second gasket are temporarily joined while mutual movement between the elastic components occurs in contact with each other. Thereafter, when the welded first and second gaskets expand to the same size as the opening volume of the composite extrusion mold, they are pressurized by the composite compression mold from then on, thereby forming the elastic body and the second gasket constituting the first gasket. By firm bonding between the elastomer components, the first gasket and the second gasket are integrated to complete the composite gasket. The composite gasket is then extruded from the composite extrusion mold.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are only for clearly illustrating the present invention and do not limit the protection scope of the present invention.

<Examples>

The first gasket was extruded from a silicone rubber having a hardness of 50 ± 5 by the KSM 6511 test method. In addition, the composition was prepared with a volume ratio of silicon rubber: silver-coated copper particles having a hardness of 50 ± 5 by KSMM 6511 test method 1: 1, and a second gasket was extruded therefrom. The extrusion temperature of the first gasket and the second gasket was about 200 ° C. Thereafter, the first gasket and the second gasket were supplied to the composite extrusion mold and extruded again in a bonded state to prepare a composite gasket. The manufactured composite gasket was inserted into a gap between the inside of the radar main body and the cover, and then assembled to seal the inside of the radar electronic component.

The US military standard physical environment test (MIL-STD-810-F, Method 506.4) was conducted with radar to evaluate the watertightness of the composite gasket. Results The radar met US military standards for rainfall. In addition, the US military standard electromagnetic environment test (MIL-STD-461E RE102) was performed to evaluate the electromagnetic shielding ability of the composite gasket. Results The radar meets US military standards for electromagnetic environment.

So far, the present invention has been described with reference to the preferred embodiments. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

10, 130: first gasket 20, 140: second gasket
110: upper housing 120: lower housing
115, 125: conductive layer 200: first extrusion mold
300: second extrusion mold 400: composite extrusion mold

Claims (17)

A first gasket having a hollow inside and formed of an elastomer; And
A second gasket joined to one side of the first gasket as a continuum and integrated with each other and formed of a conductive elastic body;
The composite gasket is inserted into the gap of the electronic device is characterized in that the electromagnetic waves generated from the inside of the electronic device to block the discharge to the outside of the electronic device and to prevent the outside air flow into the electronic device.
The composite gasket of claim 1, wherein the conductive elastomer is a composition in which conductive powder is uniformly dispersed in the elastic body.
The composite gasket according to claim 2, wherein the volume ratio of the conductive powder: elastomer constituting the second gasket is 1: 4 to 7: 3.
The conductive powder constituting the second gasket is selected from the group consisting of gold, silver, copper, aluminum, nickel, silver coated copper, silver coated nickel, nickel coated copper, and expanded graphite. Composite gasket, characterized in that composed of one or more.
4. The composite gasket of claim 3, wherein the elastic body constituting the second gasket is made of the same material as the elastic body constituting the first gasket.
The method of claim 5, wherein the elastic body constituting the first gasket and the second gasket is silicon rubber, ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), Selected from the group consisting of styrene-butadiene rubber (SBR), chloroprene rubber (CR), thermoplastic polyurethane, thermoplastic elastomer (TPE), and thermoplastic olefin (TPO) Composite gasket, characterized in that composed of one or more.
7. The composite gasket of claim 6, wherein the elastic bodies constituting the first gasket and the second gasket are silicon rubber having a hardness of 50 ± 5 according to the KSM 6511 test method.
The composite gasket according to any one of claims 1 to 7, wherein the first gasket has a wedge shape in which lower ends of both sides are inclined outward.
8. The composite gasket according to any one of claims 1 to 7, wherein the first gasket has a dome shape at an upper portion thereof.
The method according to any one of claims 2 to 7, wherein the joining of the first gasket and the second gasket is formed by adhesion between the elastic body constituting the first gasket and the elastic component constituting the second gasket. Composite gaskets.
The composite gasket according to any one of claims 1 to 7, wherein the first gasket and the second gasket are formed by extrusion molding.
12. The composite gasket of claim 11, wherein the extruded first gasket and the extruded second gasket are fed into one mold, integrated in a bonded state, and then extruded again.
An upper housing wherein a portion of the surface is conductive;
A lower housing wherein a portion of the surface is conductive; And
A composite gasket according to any one of claims 1 to 7;
The composite gasket is inserted between the upper lower housing and the lower housing to seal between the upper housing and the lower housing.
The electronic device of claim 13, wherein the second gasket is electrically connected to a portion of the conductive surface of the upper housing and a portion of the conductive surface of the lower housing.
The electronic device of claim 13, wherein the upper housing or the lower housing comprises a sandwich panel and a conductive layer laminated on one surface of the sandwich panel.
The electronic device of claim 13, wherein an electronic component is disposed in a space formed between a conductive surface portion of the upper housing and a conductive surface portion of the lower housing.
17. The electronic device of claim 16, wherein the electronic device is a radar.

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