KR20190019724A - MLCC having attenuation function for vibration energy and composite functional assembly using the same - Google Patents

Abstract

Disclosed is a multi-layered ceramic capacitor (MLCC) which can attenuate vibration energy of an MLCC soldered to a printed circuit board. The MLCC comprises: a dielectric ceramic main body having an internal electrode embedded therein; and an external electrode formed on both ends of the main body facing each other, and including a first electrode formed in direct contact with the main body, second electrode surrounding the first electrode, and a plating layer formed on an outer surface of the second electrode. The MLCC further comprises: an exposed surface including at least a lower surface of the main body; and a coating layer coated by covering at least an end band of the first electrode on the exposed surface. The first and second electrodes are overlapped by interposing a part of the coating layer in an end band part of the first electrode.

Description

[0001] The present invention relates to an MLCC having a vibration energy attenuation function and a composite functional device using the MLCC,

The present invention relates to an MLCC, and more particularly, to a technique capable of attenuating energy, including acoustic noise and mechanical vibration, of an MLCC mounted soldered to a printed circuit board.

Multilayer ceramic capacitors (hereinafter, referred to as MLCCs) are used in a variety of electronic devices because of their small size, high capacity, and ease of mounting.

Such an MLCC has a structure in which internal electrodes of different polarities are alternately arranged inside a dielectric ceramic body. Since the main body has piezoelectricity due to a high dielectric constant, a piezoelectric phenomenon occurs between internal electrodes when an AC voltage is applied, It is possible to generate periodic vibration while expanding and contracting the volume of the ceramic body.

Such vibration may be transmitted to the substrate through the external electrode of the MLCC and the solder layer, and the entire substrate may become an acoustic reflection surface, which may generate a noisy vibration sound.

Such a vibration sound may correspond to an audible frequency in the range of 20 to 20,000 Hz which is uncomfortable to a person, and the unpleasant vibration sound is referred to as acoustic noise.

In addition, cracks can be generated in the solder layer connecting the circuit board and the MLCC by mechanical vibration.

To solve this problem, in Korean Patent Laid-Open Publication No. 2016-37072, two mounting electrodes electrically connected to the external electrodes of the MLCC are formed on the upper surface, and two connection electrodes electrically connected to the lands of the circuit board are formed on the lower surface , And a plurality of mounting electrodes and connection electrodes are electrically connected to each other through via holes.

Also, in Korean Patent Laid-Open Publication No. 2016-89738, an L-shaped insulating frame arranged to surround a part of the external electrodes of the multilayer ceramic capacitor, an external conductor electrode is disposed on the outer surface of the insulating frame, And an inner conductor electrode connected to the outer electrode is disposed on the inner surface of the ceramic substrate, and the outer conductor electrode and the inner conductor electrode are electrically connected to each other.

In addition, according to Korean Patent Laid-Open Publication No. 2014-136740, in order to prevent the solder placed on the mounting surface from rising on a surface vertical to the mounting surface due to surface tension on the external electrode, The electrodes are covered with the insulating layer so that the solder does not rise or rises to a very small extent, so that the acoustic noise is remarkably reduced.

However, these conventional techniques can obtain the respective effects of reducing acoustic noise, but they have the following problems.

First, since the board-type terminal or the insulating frame is interposed between the MLCC and the circuit board, at least two bonding or soldering must be performed, so that the mounting process is complicated and the manufacturing cost is increased accordingly.

Likewise, there is a problem that the soldering strength is weak because the substrate-type terminal or the insulating frame is interposed between the MLCC and the circuit board and the solder does not form a solder fillet directly on the external electrode of the MLCC during soldering .

This problem occurs not only in the MLCC but also in a complex functional device constituted by stacking MLCC and other functional devices.

On the other hand, there is a need for an MLCC having resistance to ESD, and an MLCC in which an electrode is formed through an air gap space of a minute size is proposed in the MLCC. Since an inert gas is not included in the air gap, Reliability issues have been pointed out due to contamination of fine-sized air gaps during repeated ESD inlet and discharge processes.

Accordingly, it is an object of the present invention to provide an MLCC capable of minimizing the transfer of vibration energy to a substrate.

Another object of the present invention is to provide an MLCC having a vibration energy attenuating function which is easy to mount on a circuit board and can reduce manufacturing cost.

Another object of the present invention is to provide an MLCC having a vibration energy attenuation function with improved soldering strength by a solder fillet.

It is another object of the present invention to provide an MLCC in which a circuit board can prevent cracking of a solder layer due to vibration energy.

Another object of the present invention is to provide an MLCC having high ESD resistance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a composite functional device in which MLCCs and other functional devices are reliably joined to prevent the risk of electrical shorting due to process variables.

According to an aspect of the present invention, there is provided a plasma display panel comprising: a dielectric ceramic body having internal electrodes embedded therein; and external electrodes formed on opposite ends of the body, the external electrodes comprising: a first electrode formed in direct contact with the body; And a second electrode surrounding the first electrode, wherein the MLCC comprises: an exposed surface including at least an under surface of the body; and a coating layer covering the end band of the first electrode at least at the exposed surface, Wherein the first electrode and the second electrode are overlapped with each other via a part of the coating layer in the end band portion of the first electrode and a solder fillet is formed which rises to the second electrode by soldering with an object The MLCC has a vibration energy attenuation function.

Preferably, the coating layer is made of a polymer material having heat resistance to withstand soldering and has stretchability, elasticity and flexibility, and the coating layer is formed by any one of vapor deposition, printing, and dipping, .

Preferably, the coating layer may be comprised of Teflon, polyimide, epoxy, or parylene.

Preferably, the coating layer is removed by mechanical grinding at both end faces of the first electrode.

Preferably, the coating layer is coated over the entire exposed surface of the body and the entire end band of the first electrode.

Preferably, the body has electrical and electrical insulation properties and the coating layer is electrically insulating and fired.

Preferably, a plating layer may be formed on an outer surface of the second electrode.

Preferably, the distance between the external electrodes is shorter than the distance between the internal electrodes, so that the static electricity introduced from the outside is discharged to the surface of the main body.

Preferably, grooves having a constant width and depth may be formed extending in the longitudinal direction from the upper surface of the main body.

Preferably, a pair of grooves opposed to the upper surface of the body is formed to have a predetermined length from both ends, and extended external electrodes may be formed on the bottom of each of the grooves to be electrically connected to the external electrodes.

Preferably, a pair of grooves may be formed on the top surface of the main body so as to be spaced apart from both ends and overlapped with the outer electrode, and an extended outer electrode electrically connected to the outer electrode may be formed on the bottom of the groove.

According to another aspect of the present invention, there is provided a plasma display panel comprising a dielectric ceramic body having internal electrodes embedded therein, and external electrodes formed at opposite ends of the body, wherein the external electrodes are formed in direct contact with the body, Wherein the MLCC includes an exposed surface including at least a lower surface of the main body and a coating layer covering an end band of the external electrode at least at the exposed surface, Wherein the external electrode overlaps with the main body via a part of the coating layer and forms a solder fillet which rises to the outer surface of the external electrode by soldering with the object. Is provided.

According to another aspect of the present invention, an MLCC and other ceramic functional devices are stacked to form a laminate, and the external electrode of the laminate includes: a first electrode formed on both sides of the MLCC and the functional device; A second electrode covering the first electrode at one time; And a plating layer formed on an outer surface of the second electrode, wherein the layered body includes a coating layer that is coated with an exposed surface of the layered body and at least an end band of the first electrode on the exposed surface Wherein the first electrode and the second electrode are overlapped with each other through a part of the coating layer in the end band portion of the first electrode and solder fillets rising to the second electrode are formed by soldering with the object A composite functional device having a vibration energy attenuation function is provided.

According to another aspect of the present invention, an MLCC and other ceramic functional elements are stacked to form a laminate, and the external electrode of the laminate includes: a first electrode formed on both ends of the laminate; A second electrode surrounding the first electrode; And a plating layer formed on an outer surface of the second electrode, wherein the layered body includes a coating layer that is coated with an exposed surface of the layered body and at least an end band of the first electrode on the exposed surface Wherein the first electrode and the second electrode are overlapped with each other through a part of the coating layer in the end band portion of the first electrode and solder fillets rising to the second electrode are formed by soldering with the object A composite functional device having a vibration energy attenuation function is provided.

According to another aspect of the present invention, there is provided a method of manufacturing a MLCC, the method comprising: dipping a dielectric ceramic body of the MLCC at opposite ends thereof into a liquid conductive material comprising an epoxy resin and a metal powder; Forming a coating layer having elasticity, flexibility and stretchability on an exposed surface including at least a lower surface of the body; Exposing an end face of the first electrode by grinding a portion of the coating layer corresponding to both end faces of the first electrode; Dipping the opposing opposite ends of the body into the liquid conductive material and curing to form a second electrode; And forming a plating layer of silver or tin / gold on the second electrode, wherein, by forming the second electrode, the second electrode is electrically connected to a portion of the coating layer in the endband portion of the first electrode Wherein the first electrode is surrounded by the first electrode and the second electrode is directly contacted with the first electrode at another portion of the first electrode, thereby electrically connecting the MLCC.

According to the above structure, since the end band portion of the external electrode and the main body are in contact via the coating layer having elasticity, flexibility and stretchability, the vibration energy generated in the main body is absorbed by the coating layer to attenuate, thereby minimizing the transfer to the circuit board , And as a result, it is possible to reduce the acoustic noise and to prevent cracking of the solder layer due to mechanical vibration.

In addition, since nothing is interposed between the external electrode and the solder cream, when the solder cream is hardened to form the solder layer, the solder cream is raised to the external electrode to form the solder fillet, thereby improving the soldering strength.

In addition, since there is no intervening between the MLCC and the circuit board, the process of mounting the MLCC by the soldering is simple, and the structure and the shape are simple, so that the manufacturing cost is low due to mass production, .

In addition, the coating layer can protect the device from chip surface contamination that can occur during the overall component handling process such as packaging, surface mounting, and soldering of the MLCC.

In addition, the electrode tip extended from the external electrode can be formed on the surface of the MLCC to induce discharge of the introduced ESD, and the dielectric breakdown due to the electrostatic discharge can be prevented even in a small MLCC having a capacitance lower than 1 V .

Further, by using the coating layer for the purpose of bonding the multi-function functional elements including the MLCC to each other in addition to the attenuation of the acoustic noise, it is possible to improve the bonding strength of the multi-functional functional element and to minimize the gap in the bonding surface.

1 shows an MLCC according to an embodiment of the present invention.
2 is a sectional view taken along line 2-2 in Fig.
3 shows an example in which the MLCC of the present invention is mounted on a circuit board.
4 is a cross-sectional view illustrating an MLCC according to another embodiment of the present invention.
Fig. 5 (a) shows an appearance of an MLCC according to another embodiment of the present invention, and Fig. 5 (b) is a cross-sectional view taken along line bb.
6 (a) shows an appearance of an MLCC according to another embodiment of the present invention, and FIG. 6 (b) is a cross-sectional view taken along line bb.
7 (a) to 7 (c) show the appearance of an MLCC according to another embodiment of the present invention, respectively.
8 shows a composite functional device according to an embodiment of the present invention.
Figure 9 shows a composite functional device 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.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 shows an MLCC according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line 2-2 in FIG.

The MLCC 100 includes a dielectric ceramic body 110 having a high dielectric constant embedded with an internal electrode 112, an external electrode 120 formed at opposite ends of the body 110, And a coated coating layer 130.

The main body 110 is fired and has electrical and electrical insulation due to a high dielectric constant, and the coating layer 130 has electrical insulation.

2, the external electrode 120 includes a first electrode 122 formed in direct contact with the main body 110, a second electrode 124 and a second electrode 124 surrounding the first electrode 122, And a plating layer 126 formed on the outer surface of the substrate.

The second electrode 124 is coated on the exposed surface of the body 110 and the curved horizontal portion of the first electrode 122, that is, the end band 122a, A part of the coating layer 130 is interposed between the endbond 122a of the first electrode 122 and the second electrode 124. As a result,

According to this structure, the coating layer 130 is made of a polymer material having heat resistance to withstand soldering, and has elasticity, elasticity, and flexibility. Therefore, when the vibration energy generated in the main body 110 is radiated through the entire surface, .

Particularly, since a part of the coating layer 130 is interposed between the endbond 122a of the first electrode 122 and the second electrode 124, the second electrode 124 to be soldered to the circuit board, as described later, The vibration transmitted to the circuit board can be attenuated, and the crack of the solder layer can be prevented.

The coating layer 130 is formed by vapor deposition, printing, or dipping, and may be mechanically or chemically bonded to the body 110. In other words, fine gaps can be formed between the main body 110 and the main body 110 by mechanical bonding, and they can be bonded completely by chemical bonding.

In this embodiment, the coating layer 130 is formed entirely on the exposed surface of the body 110, and may be formed only on the lower surface of the body 110 to attenuate the transmission of acoustic noise through the solder layer formed by soldering with the circuit board . However, it is preferable to form the coating layer 130 on the entire exposed surface of the main body 110, considering that the acoustic noise generated in the main body 110 is transmitted to all directions of the exposed surface.

In addition, the thickness of the coating layer 130 on the lower surface of the main body 110 may be made somewhat thicker than other exposed surfaces.

Hereinafter, a process of manufacturing the MLCC 100 will be described.

The opposite ends of the body 110 are dipped in a liquid conductive material made of an epoxy resin and a metal powder, and then hardened to form the first electrode 122.

Next, the coating layer 130 is formed on the entire surface of the main body 110 where the first electrodes 122 are formed at opposite ends.

The coating layer 130 may be formed by deposition, printing or dipping.

In this embodiment, the coating layer 130 is formed on the entire surface of the main body 110. However, when the main purpose is to prevent cracking of the solder layer and the absorption of vibrational energy is a secondary purpose, (130) can be formed.

The coating layer 130 is not particularly limited in thickness, but may have a thickness of about 0.5 to 30 占 퐉. The coating layer 130 may have elasticity, flexibility and stretchability to absorb vibration energy and absorb the vibration energy. For example, Polyimide, epoxy, parylene, or the like.

Particularly, since the coating layer 130 has flexibility and stretchability, even when impact or vibration is externally applied to the MLCC 100, the coating layer 130 is stretched to prevent the main body 110 from being broken.

The coating layer 130 may have acid resistance to the plating solution used to form the plating layer 126, and may be made of a material having heat resistance corresponding to the chemical resistance and the soldering temperature.

Particularly, the parylene of the polymer type penetrates into fine gaps through the vaporization and vacuum deposition process of the polymer, and has the advantage of being able to uniformly coat it with a thin thickness.

The coating layer 130 is formed on the entire surface and then the portion of the coating layer 130 corresponding to the end surface of the first electrode 122 is removed by mechanical grinding so that the end surface of the first electrode 122 is exposed.

As a result, the coating layer 130 remains only on the exposed surface of the main body 110 and the end band 122a of the first electrode 122.

Next, opposite ends of the body 110 are dipped in a liquid conductive material made of an epoxy resin and a metal powder, and then cured to form a second electrode 124.

The second electrode 124 may surround the first electrode 122 through the coating layer 130 in the end band 122a of the first electrode 122 and may be formed in the other part of the first electrode 122, One electrode 122 is directly contacted and electrically connected.

Finally, the second electrode 124 forms a plating layer 126 with silver or tin / gold to form the external electrode 120.

3 shows an example in which the MLCC of the present invention is mounted on a circuit board.

The MLCC 100 is tapped on a reel carrier and placed on the land pattern 12 of the circuit board 10 using surface mount technology (SMT). After mounting on the solder cream formed on the land pattern 12, And is mounted on the solder layer 14.

Since nothing is interposed between the external electrode and the solder cream to form the solder filler 14a as the solder cream rises up to the external electrode 120 when the melted solder cream is cured to form the solder layer 14, The strength is improved.

Since the end portion 122a of the first electrode 122 of the external electrode 120 contacts with the second electrode 124 via the coating layer 130 having elasticity and flexibility and stretchability, Can be absorbed and attenuated in the coating layer 130 to reduce acoustic noise and to prevent cracking of the solder layer 14 due to mechanical vibration.

Incidentally, the coating layer 130 can protect the device from chip surface contamination that may occur in the overall component handling process such as packaging, surface mounting, and soldering of the MLCC 100.

4 is a cross-sectional view illustrating an MLCC according to another embodiment of the present invention.

In this embodiment, the MLCC 100 includes a dielectric ceramic body 110, an external electrode 120 formed at opposite ends of the body 110, and a coating layer 130 coated on the exposed surface of the body 110. [ The external electrode 120 includes a first electrode 125 formed in direct contact with the main body 110 and a plating layer 126 formed on an outer surface of the first electrode 125. [

Therefore, a part of the coating layer 130 is interposed between the endbond 125a of the first electrode 125 and the main body 110.

In this embodiment, the acoustic noise generated in the main body 110 is transmitted to the coating layer 130 and attenuated, and the vibration energy of the main body 110 is absorbed by the coating layer 130 having elasticity, flexibility and stretchability.

In addition, since the first electrode 125 is provided, the structure is simple and the manufacturing process is simple compared to the above embodiment.

In the following embodiments, an MLCC having a coating layer to attenuate vibrational energy will be described in which an electrode tip extending from an external electrode is formed on the surface of an MLCC to induce and discharge induced ESD through the electrode tip.

5 (a) shows an appearance of an MLCC according to another embodiment of the present invention, and Fig. 5 (b) is a cross-sectional view taken along line b-b.

In this embodiment, the distance d between the outer electrodes 120 is closer to the distance L between the inner electrodes 112 buried in the inner portion of the main body 110.

That is, as described above, when the external electrodes 120 are formed by dipping both ends of the main body 110 into the liquid conductive paste, endbands of a predetermined distance BW1 to BW4 are formed so that the distance between the external electrodes 120 d is formed to be closer to the distance L between the internal electrodes 112.

According to this structure, ESD introduced from the outside can be discharged to the surface of the main body 110 rather than the inside thereof.

The effect of the above structure is effective for a small size MLCC having a size of 1005 [metric] or smaller. In particular, in the case of 0603 [metric], the length of the main body 110 is 0.6 mm, so that induced discharge of the introduced static electricity can be efficient.

6 (a) is an external view of an MLCC according to another embodiment of the present invention, and FIG. 6 (b) is a cross-sectional view taken along line b-b.

A groove 140 having a predetermined width and depth is extended from the top surface of the main body 110 in the longitudinal direction and a coating layer 130 is formed on the exposed surface of the main body 110 including the grooves 140 do.

A pair of extended external electrodes 120a (or electrode tips) having a certain length from both ends of the groove 140 are formed on the bottom of the grooves 140 and are formed integrally with the external electrodes 120.

The distance d between the pair of extended external electrodes 120a is designed to be smaller than the distance between the external electrodes 120 formed on the lower surface of the main body 110 and closer to the distance L between the internal electrodes.

As described above, when the static electricity flows into the MLCC, the extended external electrode 120a formed on the upper surface of the MLCC preferentially induces the electrostatic discharge and has the effect of maintaining the insulation property of the MLCC.

7 (a) to 7 (c) show the appearance of an MLCC according to another embodiment of the present invention, respectively.

7A, a pair of grooves 141 and 142 facing the upper surface of the main body 110 are formed to have a constant length from both ends, and extended external electrodes 141 and 142 are formed on the bottoms of the grooves 141 and 142, (120a) is formed and is formed integrally with the external electrode (120).

The above structure is different from the shape of the grooves 140 of FIG. 5, and has an advantage that the length of the extended external electrode 120a can be efficiently controlled.

Referring to FIG. 7B, a pair of grooves 143 and 144 having extended external electrodes 120a are formed on the bottom surface of the main body 110 so as to overlap with the external electrodes 120 do.

Unlike the grooves 140, 141, and 142, the structure has a certain size and depth on the surface of the chip, so that the thickness of the electrode used as the discharge electrode can be reliably secured.

7 (c) is a modification of Fig. 7 (a), in which a groove 145 is formed extending in the width direction in the middle of the grooves 141 and 142. As shown in Fig. Since the grooves 145 are located at a certain depth from the dielectric ceramic surface, when the repeated electrostatic discharge occurs between the two extended external electrodes 120a, the grooves 145 are spaced apart from the connected contamination that may occur on the ceramic surface, And thus it is possible to help maintain a stable insulation state.

Hereinafter, a structure capable of improving the bonding strength between functional devices in addition to the application of a coating layer to a multi-functional device having an MLCC to attenuate acoustic noise will be described.

8 shows a composite functional device according to an embodiment of the present invention.

The composite functional device 200 includes a fired varistor 210 which is laminated and joined with a bonding agent 240, first electrodes 212 and 222 of the MLCC 220, the varistor 210, and the MLCC 220, The coating layer 230 coated on the exposed surface of the varistor 210 and the MLCC 220 stacked body and the common second electrode 250 wrapped around the first electrodes 212 and 222 to be buried are exposed do.

The first electrodes 212 and 222 and the second common electrode 240 are formed by curing after being dipped in a liquid conductive material made of an epoxy resin and a metal powder. The coating layer 230 is exposed by grinding.

Here, the bonding agent 240 is for bonding between the varistor 210 and the MLCC 220, and may be omitted by applying the coating layer 230.

The first electrode 212 of the varistor 210 and the first electrode 222 of the MLCC 220 may be in physical contact with each other or may be mechanically or chemically Lt; / RTI > For example, if the bonding agent 240 is applied in a state where the first electrodes 212 and 222 are made of an epoxy-based conductive material and then a post-process such as heat treatment is performed, The chemical bonding can proceed through the epoxy that is formed. As another example, the contact surfaces of the first electrodes 212 and 222 may be formed to have high mechanical strength by joining the contact surfaces of the first electrodes 212 and 222 through external heat treatment such as fusion bonding by ultrasonic welding.

According to this embodiment, a gap is present between the varistor 210 and the MLCC 220 which are stacked due to the presence of a gap due to the absence of the bonding agent 240 or the uneven application of the bonding agent 230, Since the outer surface of the varistor 210 and the MLCC 220 are covered by the coating layer 230 even if the physical and chemical functions of the varistor 210 and the MLCC 220 are weak, The contact portions of the electrodes 212 and 222 can be protected together.

Since the varistor 210 and the MLCC 220 are wrapped by the coating layer 230, the bonding strength of the varistor 210 and the MLCC 220 can be increased There is an advantage.

The MLCC 220 can be applied to circuits having various capacitance capacities and serving as a filtering function or DC blocking function in various frequency ranges. The overvoltage of the static electricity or the like flowing in the circuit is attenuated by the varistor 210. The MLCC 220 is relatively vulnerable to excessive energy due to electrostatic discharge or a surge current. However, since the varistor 210 connected in parallel structure absorbs and limits the transient energy, the MLCC 220 protects the MLCC 220 .

As another example, the ceramic functional device 210 may be an NTC thermistor, and the ceramic functional device 220 may be a chip fixed resistor. Such a configuration may serve as a linear resistor applied to the temperature change sensing circuit, As a result, it is possible to reduce the space to be mounted on the printed circuit board.

As described above, the ceramic functional devices 210 and 220 may be composed of two or more of a varistor, a capacitor, an NTC thermistor, a PTC thermistor, an inductor, and a chip fixing resistor to constitute a complex functional device.

On the other hand, the MLCC is located at a lower portion in at least the multifunction functional device 200 including the MLCC. For example, the sintered body of a MLCC made of a dielectric ceramic has higher density and higher mechanical strength than a varistor, a thermistor, or a magnetic ceramic inductor made of a semiconductor ceramic.

In addition, since the functional device located below the multifunction device 200 has a portion contacting the circuit board on which the multifunction device 200 is mounted, there is a high possibility that the functional device 200 is affected by the external shock. Therefore, when a functional device having a relatively low plastic density is located below the multi-function device 200, there is a high risk that mechanical defects such as cracks will occur in a process such as soldering.

In consideration of this point, it is preferable that the MLCC is located at the bottom in at least the multifunction functional device 200 including the MLCC.

Figure 9 shows a composite functional device according to another embodiment of the present invention.

The composite functional device 300 includes a varistor 310, an MLCC 320, a varistor 310, and an MLCC 320 laminated in a state in which external electrodes are not formed and joined together via a bonding agent 340 A first electrode 352 formed on each of opposite side surfaces and electrically connected to each of the internal electrodes 311 and 312 and a varistor 310 and an MLCC 320 laminated body except for an end surface of the first electrode 352. [ And a second electrode 354 wrapped around the coating layer 330 and the first electrode 352.

The varistor 310 and the MLCC 320 laminate are coated with the coating layer 330 except for the end face of the first electrode 352 and the second electrode 354 is coated on the end face of the first electrode 352, As shown in FIG.

As described above, the varistor 310 and the MLCC 320 are joined together by the bonding agent 340 in the state where external electrodes are not formed. As a result, the bonding agent 340 can be uniformly applied because there is no space on the bonding surface due to the contact between the varistor 310 and the external electrodes of the MLCC 320, and the density of the bonding agent 340 Can be increased. In other words, the bonding agent 340 can be applied to the varistor 310 and the MLCC 320 where the external electrode is present. Particularly, after the bonding agent 340 is coated on the MLCC 320, It is possible to enlarge the bonding surface to a wide area because the flow of the bonding agent 340 is smooth.

In addition, since the varistor 310 and the MLCC 320 are laminated and bonded to each other by the first electrode 350 in the state of being bonded by the bonding agent 340, the bonding strength is also advantageous.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Accordingly, the scope of the present invention should not be construed as being limited to the embodiments described above, but should be construed in view of the claims set forth below.

100: MLCC
110:
112: internal electrode
120: external electrode
122: first terminal
124: second terminal
126: Plating layer
130: Coating layer
200, 300: Multifunctional functional element

Claims (19)

An MLCC comprising a dielectric ceramic body having internal electrodes embedded therein and external electrodes formed at opposite ends of the body,
The external electrode
A first electrode that is in direct contact with the body and is electrically connected to the internal electrode; And
And a second electrode surrounding the first electrode,
Wherein the MLCC includes an exposed surface including at least a lower surface of the body and a coating layer covering at least an end band of the first electrode on the exposed surface,
Wherein the first electrode and the second electrode are overlapped with each other via a part of the coating layer in the end band portion of the first electrode,
And a solder fillet rising to the second electrode is formed by soldering to an object. In claim 1,
Wherein the coating layer is made of a polymer material having heat resistance to withstand soldering, and has elasticity, flexibility and flexibility. In claim 2,
Wherein the coating layer is formed by vapor deposition, printing, or dipping. In claim 1,
Wherein the coating layer has a thickness of 0.5 占 퐉 to 30 占 퐉. In claim 1,
Wherein the coating layer is composed of Teflon, polyimide, epoxy, or parylene. In claim 1,
Wherein the coating layer is removed by mechanical grinding at both end surfaces of the first electrode. In claim 1,
Wherein the coating layer is coated by covering the entire exposed surface of the body and the entire end band of the first electrode. In claim 1,
Wherein the body has electrical and electrical insulation properties and the coating layer has electrical insulation properties. In claim 1,
And a plating layer is formed on an outer surface of the second electrode. In claim 1,
Wherein the coating layer is formed on the entire exposed surface of the main body, and is coated by covering the entire end band of the first electrode. In claim 1,
Wherein the body is fired. In claim 1,
Wherein a distance between the external electrodes is shorter than a distance between the internal electrodes, so that static electricity introduced from the outside is discharged to the surface of the main body and discharged. In claim 1,
Wherein a groove having a predetermined width and a predetermined depth is formed on the upper surface of the main body in the longitudinal direction of the MLCC. In claim 1,
A pair of grooves opposed to the upper surface of the main body are formed to have a constant length from both ends,
And an extended external electrode is formed on the bottom of each of the grooves so as to be electrically connected to the external electrode. In claim 1,
A pair of grooves are formed on the upper surface of the main body so as to be spaced apart from both ends and overlap the external electrodes,
And an extended external electrode electrically connected to the external electrode is formed on the bottom of the groove. An MLCC comprising a dielectric ceramic body having internal electrodes embedded therein and external electrodes formed at opposite ends of the body,
Wherein the external electrode is formed in direct contact with the body, and is electrically connected to the internal electrode,
Wherein the MLCC includes an exposed surface including at least a lower surface of the main body and a coating layer covering at least an end band of the external electrode at the exposed surface,
Wherein the outer electrode is overlapped with the main body through a part of the coating layer in an end band portion of the outer electrode,
And a solder fillet is formed on the outer surface of the external electrode by soldering with the object. MLCC and other ceramic functional devices are laminated to constitute a laminate,
Wherein the external electrode of the laminate comprises:
A first electrode formed on both ends of the MLCC and the functional device; And
And a second electrode covering the first electrode at a time,
Wherein the laminate includes a coating layer which is coated by coating an exposed surface of the laminate and at least an end band of the first electrode on the exposed surface,
Wherein the first electrode and the second electrode are overlapped with each other via a part of the coating layer in the end band portion of the first electrode,
And a solder fillet rising to the second electrode is formed by soldering to an object. MLCC and other ceramic functional devices are laminated to constitute a laminate,
Wherein the external electrode of the laminate comprises:
A first electrode formed on both ends of the laminate; And
And a second electrode surrounding the first electrode,
Wherein the laminate includes a coating layer that is coated with an exposed surface of the laminate and at least an end band of the first electrode on the exposed surface,
Wherein the first electrode and the second electrode are overlapped with each other via a part of the coating layer in the end band portion of the first electrode,
And a solder fillet rising to the second electrode is formed by soldering to an object. Dipping the opposing opposite ends of the dielectric ceramic body of the MLCC into a liquid conductive material made of an epoxy resin and a metal powder, and then curing to form a first electrode;
Forming a coating layer having elasticity, flexibility and stretchability on an exposed surface including at least a lower surface of the body;
Exposing an end face of the first electrode by grinding a portion of the coating layer corresponding to both end faces of the first electrode;
Dipping the opposing opposite ends of the body into the liquid conductive material and curing to form a second electrode; And
Forming a plating layer of silver or tin / gold on the second electrode,
Wherein the second electrode surrounds the first electrode through a part of the coating layer in the end band portion of the first electrode, and the second electrode surrounds the first electrode at another portion of the first electrode, Wherein the electrodes are directly connected to the electrodes and are electrically connected to each other.

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