KR20190075385A - Apparatus and method for treating surface of multi-layer ceramic capacitor - Google Patents

Abstract

According to an embodiment of the present invention, an apparatus for treating the surface of a multilayer ceramic capacitor is provided. The apparatus includes a chamber where a plasma is formed; a stage which is positioned in the chamber, has a conductive tape layer disposed on an upper surface thereof, and has a space for accommodating a multilayer ceramic capacitor (MLCC) on the upper surface of the conductive tape layer; and an electron gun which includes an acceleration electrode including a cathode and an anode and a solenoid coil, and for irradiating a pulse beam on the stage through the plasma, and a control part for controlling the electron gun and the stage. The control part adjusts the voltage of the acceleration electrode to 12 kV to 13 kV. It is possible to improve stability and yield.

Description

TECHNICAL FIELD [0001] The present invention relates to a multilayer ceramic capacitor surface treatment apparatus and method,

An embodiment of the present invention relates to an apparatus and a method for treating a multilayer ceramic capacitor.

Recently, as the trend toward miniaturization of electronic devices has progressed rapidly, miniaturization and performance improvement of electronic parts are progressing at a rapid pace. Also, electronic parts requiring high reliability corresponding to electrical products and industrial applications such as automobiles and network equipments . Competition is accelerating in the development of passive components (inductors, capacitors, and resistors) to meet these market demands. Particularly in the case of multilayer ceramic chip capacitors (MLCCs), thinner dielectric layers and internal electrode layers Efforts are being made to preoccupy the market by developing ultra-high-capacity products.

A multilayer ceramic capacitor is manufactured by laminating a printed sheet obtained by printing and drying an internal electrode paste on a ceramic green sheet, and laminating it. The internal electrode paste includes a metal powder, a ceramic powder, a dispersant, an additive, a binder and a solvent, which are materials of the internal electrode. When the internal electrode paste is printed on the ceramic green sheet, metal powder, ceramic powder, solvent, and other organic materials are present in a coated state.

However, when the paste is dried, the components such as the solvent contained in the paste are volatilized, resulting in a porous space partially on the dry surface, reduced density, and irregular curves of the print thickness section.

Therefore, in order to make the printing thickness of the internal electrode layer uniform, the dispersibility is increased in the mixing process of the metal powder used for manufacturing the internal electrode paste, the ceramic powder, the dispersant, the additive, the binder and the solvent, It is important.

On the other hand, the surface roughness (roughness), which is a measure indicating the dry surface shape of the printing section curve, is mainly expressed by the centerline average roughness Ra of the cross-sectional curve and the highest value roughness Rmax obtained by taking the highest portion from the centerline and the highest portion.

Here, the higher the roughness Ra, the more uneven the dry surface and the higher the difference in height. The higher the Rmax, the more uneven the thickness of each measurement site and the irregularity of the dry surface. It is also possible to check the illuminance by dividing the height in the form of a contour line by observing the microscopic surface enlarged.

In the manufacturing process of a multilayer ceramic capacitor, a paste is printed on a ceramic green sheet, and a dried printed sheet is stacked with a stack of hundreds of layers. In this case, a short defect may occur when the dry surface roughness of the paste is locally high.

An object of the present invention is to provide a multilayer ceramic capacitor surface treatment apparatus and method capable of improving stability and yield through planarization of surface roughness.

According to an embodiment of the present invention, there is provided a plasma processing apparatus including: a chamber in which a plasma is formed; A stage disposed in the chamber and having a conductive tape layer disposed on an upper surface thereof and a space for accommodating a multi-layer ceramic capacitor (MLCC) on an upper surface of the conductive tape layer; And a control unit for controlling the electron gun and the stage, wherein the controller controls the voltage of the accelerating electrode and the voltage of the accelerating electrode, Is adjusted to 12 kV to 13 kV.

The conductive tape layer may include a carbon tape.

A plurality of multilayer ceramic capacitors may be disposed on the conductive tape layer at a predetermined interval.

The control unit may control the electron gun and the stage to control the pulse beam to be irradiated to the termination of the multilayer ceramic capacitor.

The controller may adjust the voltage of the solenoid coil to 0.5 to 1.5 kV to adjust the radius of rotation of the pulse beam accelerator electron.

According to an embodiment of the present invention, there is provided a method comprising: placing a conductive tape layer on a stage in a chamber; Disposing a multilayer ceramic capacitor on the conductive tape layer; Generating a plasma in the chamber by applying a pulse current to the solenoid coil; Adjusting the voltage of the acceleration electrode including the cathode and the anode in the chamber from 12 kV to 13 kV; Generating a pulse beam between the acceleration electrodes; And the pulse beam is spirally accelerated by a solenoid coil and irradiated to the multilayer ceramic capacitor on the stage.

The conductive tape layer may include a carbon tape.

A plurality of multilayer ceramic capacitors may be disposed on the conductive tape layer at a predetermined interval.

The controller may further include adjusting a rotation radius of the pulse beam accelerator electron by adjusting a voltage of the solenoid coil to 0.5 to 1.5 kV.

Controlling the electron gun and the stage to control the pulse beam to be irradiated to a termination portion of the multilayer ceramic capacitor.

And coating the surface of the multilayer ceramic capacitor irradiated with the pulse beam.

The multilayer ceramic capacitor surface treatment apparatus and method of the present invention can improve the stability and yield by flattening the surface roughness of the multilayer ceramic capacitor.

In addition, cracks in the multilayer ceramic capacitor can be prevented by irradiating a pulse beam having an optimum intensity.

In addition, an environmentally friendly technique can improve the surface performance of a material to be treated without using chemical harmful substances.

1 is a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention.
2 is a cross-sectional view of a multilayer ceramic capacitor surface treatment apparatus according to an embodiment of the present invention.
3 is an image for explaining the result of the multilayer ceramic capacitor surface treatment according to the embodiment of the present invention.
4 to 9 are views for explaining a comparative example for comparison with the result of the finishing treatment of the multilayer ceramic capacitor according to the embodiment of the present invention.
10 is a flowchart of a surface treatment method of a multilayer ceramic capacitor according to an embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms including ordinal, such as second, first, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as a first component, and similarly, the first component may also be referred to as a second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description thereof will be omitted.

1 is a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. Referring to FIG. 1, the multilayer ceramic capacitor 100 includes a body 110. The body 110 may have a hexahedral shape. The edges of the body 110 include rounded corners or ridges, and irregularities may be formed on the surface.

The body 110 may include a plurality of stacked ceramic layers 120 and a plurality of internal electrodes 130 formed along a specific interface between the plurality of ceramic layers 120.

The ceramic layer 120 may be made of a dielectric ceramic containing barium titanate (BaTiO3), calcium titanate (CaTiO3), strontium titanate (SrTiO3), or calcium zirconate (CaZrO3) as a main component. The ceramic layer 120 may further contain Mn, Mg, Si, Co, Ni, rare earth elements, or the like as a subcomponent.

External electrodes 140, which are electrically connected to the internal electrodes 130, may be formed on the side surfaces of the body 110 facing each other. The external electrode 140 may be formed by baking, for example, a conductive paste containing Ni powder and ceramic powder.

The external electrodes 140 may be formed to cover the edges or corners of the body 110.

A plating film may be formed on the external electrode 140. The plated film may be composed of, for example, a Cu plated film, or may be composed of a Cu plated layer, a Ni plated layer thereon, and a Sn plated layer thereon. For example, when the multilayer ceramic capacitor 100 is provided on a multilayer substrate, a Cu plated film may be formed, and in the case where the multilayer ceramic capacitor 100 is used as a surface mounted component, a plated film composed of a Cu plating layer, a Ni plating layer, and a Sn plating layer may be formed .

In the present invention, the plating film for mounting the external electrode 140 of the multilayer ceramic capacitor 100 will be described as a termination.

2 is a cross-sectional view of a multilayer ceramic capacitor surface treatment apparatus according to an embodiment of the present invention.

1 and 2, a multilayer ceramic capacitor surface treatment apparatus according to the present invention includes a chamber 10, a stage 20, a conductive tape layer 21, an electron gun 30, and a control unit 40, .

The chamber 10 is in a vacuum state and is filled with argon gas. The inside of the chamber 10 is evacuated to 0.03 Pa, and argon (Ar) gas is injected to maintain the degree of vacuum at 0.05 Pa.

The stage 20 is located inside the chamber 10 and can accommodate the multilayer ceramic capacitor 100. The stage 20 may be positioned in the irradiation direction of the pulse beam so that the pulse beam can be irradiated. The stage 20 is provided so as to be rotatable and movable under the control of the control unit 40.

A conductive tape layer 21 may be disposed on the top of the stage 20. The conductive tape layer 21 may be arranged to cover a part or the entire surface of the upper surface of the stage 20 along the upper surface of the stage 20. [ A space for accommodating the multilayer ceramic capacitor 100 may be provided on the upper surface of the conductive tape layer 21. The conductive tape layer 21 can transfer heat generated on the stage 20 to the multilayer ceramic capacitor 100. The conductive tape layer 21 may be made of a material having excellent heat conduction characteristics, and may be made of, for example, carbon tape.

The multilayer ceramic capacitor 100 may be disposed along the upper surface of the conductive tape layer 21. [ The multilayer ceramic capacitor 100 may have a plurality of multilayer ceramic capacitors 100 spaced apart from the conductive tape 21 by a predetermined distance. The arrangement area and the spacing distance of the multilayer ceramic capacitor 100 may vary depending on the radius of rotation of the pulse beam accelerating electrons.

The electron gun 30 includes an acceleration electrode 33 and a solenoid coil 34 including a cathode 31 and an anode 32 and is capable of irradiating a pulse beam onto the stage 20 through plasma. The solenoid coil 34 may be disposed along the exterior of the chamber 10. When a pulse current is applied to the solenoid coil 34, electrons in the chamber are generated and maintained by application of a magnetic field. When an accelerating electrode voltage is applied between the anode 31 and the cathode 32 after sufficient plasma has been generated, electrons are generated explosively and electrons are accelerated corresponding to the applied accelerating electrode voltage. At this time, the electrons are accelerated to the helical path by using the electric and magnetic fields induced by the solenoid coil 34.

The control unit 40 can control the electron gun 30 and the stage 20. [

The control unit 40 can adjust the voltage of the accelerating electrode 33 from 12 kV to 13 kV.

In addition, the controller 40 may adjust the voltage of the solenoid coil 34 to 0.5 to 1.5 kV to adjust the radius of rotation of the pulse beam accelerator electrons.

In addition, the control unit 40 can control the pulse beam to have 1 to 10 pulses.

At this time, the control unit 40 controls the electron beam gun and the stage to control the pulse beam to be irradiated to the finishing portion 140 of the multilayer ceramic capacitor 100. That is, the control unit 40 may control the electron gun 30 and the stage 20 so that a pulse beam is irradiated to at least one of the body 110 and the finishing portion 140 of the multilayer ceramic capacitor 100. The control unit 40 irradiates the entire body 110 and the finishing portion 140 of the multilayer ceramic capacitor 100 with a pulse beam or irradiates a pulse beam only to the body 110 to improve the surface roughness, It is possible to selectively enhance the surface roughness by irradiating only the finishing portion 140 with a pulse beam. At this time, the controller 40 controls the acceleration electrode voltage of the pulse beam irradiated on the body 110 of the multilayer ceramic capacitor 100 and the number of irradiation of the pulse beam, the acceleration electrode voltage of the pulse beam irradiated on the finishing portion 140, The number of irradiation times of the pulse beam can be adjusted differently. Thus, the surface roughness of the body 110 and the finishing portion 140 of the multilayer ceramic capacitor 100 can be variously adjusted according to a desired specification.

3 is an image for explaining the result of the multilayer ceramic capacitor surface treatment according to the embodiment of the present invention.

3 is an SEM (Scanning Electron Microscope) image of a body and a closed portion of the multilayer ceramic capacitor when a pulse beam is irradiated by varying the accelerating electrode voltage Va. Referring to FIG. 3, when the accelerating electrode voltage Va is decreased from 15 kV and 14 kV to 13 kV, it can be seen that the crack of the body is remarkably reduced. Further, when the accelerating electrode voltage Va is 11 kV, it can be confirmed that the gloss of the body and the finish portion is remarkably lower than that in the case of 12 kV. Therefore, it can be confirmed that when the pulse beam is irradiated with the accelerating electrode voltage Va of 12 kV to 13 kV, the luster of the body and the finishing portion of the multilayer ceramic capacitor is remarkably improved and the generation of cracks can be significantly suppressed .

4 to 9 are views for explaining a comparative example for comparison with the result of the finishing treatment of the multilayer ceramic capacitor according to the embodiment of the present invention.

Fig. 4 is a surface image in the case where ten pulsed beams at 30 mm irradiation height are irradiated to a non-plated finish portion in accordance with an accelerating electrode voltage Va of 30 kV and a solenoid voltage of 1.5 kV. Referring to FIG. 4, by irradiation of the pulse beam, surface voids are generated in the unplated ceramic due to too high an energy density, and both the surface, the upper edge and the side edge are damaged .

FIG. 5 is a surface image when 10 pulsed beams at 30 mm irradiation height are irradiated to Cu and glass-finished portions, according to an accelerating electrode voltage (Va) of 30 kV and a solenoid voltage of 1.5 kV. Referring to FIG. 5, it can be confirmed that the finished portion is dissolved and shrunk due to rapid melting and re-solidification. In addition, the surface of the finishing portion (right portion of the surface) was polished, but the surface of the body (the left portion of the surface) was found to be severely damaged by LPEB irradiation.

FIG. 6 is a surface image when 10 pulsed beams are irradiated to Cu, Glass and Sn-finished portions at an irradiation height of 30 mm according to an accelerating electrode voltage (Va) of 30 kV and a solenoid voltage of 1.5 kV. Referring to FIG. 6, it can be seen that the finishing portion is polished in a good state by the pulse beam irradiation, but the surface of the body (the left portion of the surface) is greatly damaged. Therefore, the size of the accelerating electrode voltage Va must be reduced in order for the finishing portion and the body surface to be simultaneously polished well.

FIG. 7 is a cross-sectional SEM image obtained when one pulse beam is irradiated onto the body at an irradiation height of 30 mm according to an accelerating electrode voltage Va of 30 kV and a solenoid voltage of 1.5 kV. Referring to FIG. 7, it can be seen that the surface of the body made of ceramics is cracked and fatally damaged by the pulse beam irradiation. In addition, it can be seen that the ceramic and the internal electrode are separated by a large thermal gradient, and it can be confirmed that after the pulse beam is irradiated on the surface of the body showing the homogeneous structure, a re-adherence layer with less pores is formed.

Fig. 8 is a cross-sectional SEM image obtained when one pulse beam is irradiated onto the body at an irradiation height of 30 mm according to an accelerating electrode voltage Va of 20 kV and a solenoid voltage of 1.2 kV. Referring to FIG. 8, by decreasing the acceleration electrode voltage Va to 20 kV, a homogeneous amorphous recoat layer was formed after the pulse beam irradiation, and it was confirmed that the size of the crack was mostly reduced. However, high-density microcracks were still generated by the pulse beam irradiation, and minute delamination was observed at the interface between the body and the internal electrode.

Fig. 9 is a cross-sectional SEM image obtained when one pulse beam is irradiated onto the body at an irradiation height of 30 mm according to an accelerating electrode voltage Va of 15 kV and a solenoid voltage of 1.0 kV. Referring to FIG. 9, by decreasing the accelerating electrode voltage Va to 15 kV, fine cracks were only generated intermittently, and no peeling was observed at the interface between the body and the internal electrode. In addition, although the crack density greatly decreases after the pulse beam irradiation, it can be confirmed that further reduction of the accelerating electrode voltage Va is required to further suppress the occurrence of cracks.

Referring again to FIG. 3, when a pulse beam is irradiated according to an accelerating electrode voltage of 12 kV to 13 kV according to an embodiment of the present invention, cracks are remarkably suppressed in both the body and the finishing portion of the multilayer ceramic capacitor . In addition, it can be confirmed that the degree of polishing is remarkably improved as compared with the range of other accelerating electrode voltages.

10 is a flowchart of a surface treatment method of a multilayer ceramic capacitor according to an embodiment of the present invention.

Referring to Fig. 10, first, a conductive tape layer is disposed on a stage in a chamber. The conductive tape layer may be disposed continuously along the upper surface of the stage, and may be made of, for example, carbon tape (S1001).

Next, a multilayer ceramic capacitor is disposed on the conductive tape layer. The multilayer ceramic capacitor may be arranged such that a plurality of multilayer ceramic capacitors are spaced apart from each other by a predetermined distance (S1002).

Next, the control unit applies a pulse current to the solenoid coil to generate a plasma in the chamber. The chamber is in a vacuum state and is filled with argon gas. The interior of the chamber was evacuated to 0.03 Pa and then argon (Ar) gas was injected to maintain the degree of vacuum at 0.05 Pa. At this time, when a pulse current is applied to the solenoid coil, plasma is generated and maintained using electrons in the chamber by application of a magnetic field (S1003).

Next, the control unit adjusts the voltage of the acceleration electrode including the cathode and the anode in the chamber from 12 kV to 13 kV. The control unit applies a high voltage to the cathode to form an acceleration voltage of 12 kV to 13 kV between the anode and the cathode (S1004).

Next, a pulse beam is generated between the acceleration electrodes. After sufficient plasma is generated, when an acceleration voltage is applied between the anode and the cathode, electrons are generated explosively, and electrons are accelerated corresponding to the applied acceleration voltage to generate a pulse beam (S1005).

Next, the pulse beam is spirally accelerated by the solenoid coil and irradiated to the multilayer ceramic capacitor on the stage. The electrons are accelerated by the helical path using the electric and magnetic fields induced by the solenoid coil and irradiated to the multilayer ceramic capacitor on the stage (S1006).

As used in this embodiment, the term " portion " refers to a hardware component such as software or an FPGA (field-programmable gate array) or ASIC, and 'part' performs certain roles. However, 'part' is not meant to be limited to software or hardware. &Quot; to " may be configured to reside on an addressable storage medium and may be configured to play one or more processors. Thus, by way of example, 'parts' may refer to components such as software components, object-oriented software components, class components and task components, and processes, functions, , Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and components may be further combined with a smaller number of components and components or further components and components. In addition, the components and components may be implemented to play back one or more CPUs in a device or a secure multimedia card.

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 scope of the present invention as defined by the following claims It can be understood that

10: chamber
20: stage
30: Electron gun
40:
100: Multilayer Ceramic Capacitor
110: Body
120: Ceramic layer
130: internal electrode
140: external electrode

Claims (11)

A chamber in which a plasma is formed;
A stage disposed in the chamber and having a conductive tape layer disposed on an upper surface thereof and a space for accommodating a multi-layer ceramic capacitor (MLCC) on an upper surface of the conductive tape layer;
An electron gun including an accelerating electrode including a cathode and an anode and a solenoid coil and irradiating a pulse beam onto the stage through the plasma,
And a control unit for controlling the electron gun and the stage,
Wherein the controller adjusts the voltage of the acceleration electrode to 12 kV to 13 kV.
The method according to claim 1,
Wherein the conductive tape layer comprises a carbon tape.
3. The method of claim 2,
Wherein a plurality of multilayer ceramic capacitors are disposed above the conductive tape layer at a predetermined distance.
The apparatus of claim 1, wherein the control unit
And controls the electron gun and the stage to control the pulse beam to be irradiated to the termination of the multilayer ceramic capacitor.
The method according to claim 1,
Wherein the controller adjusts the voltage of the solenoid coil to 0.5 to 1.5 kV to adjust the radius of rotation of the pulse beam accelerator electron.
Disposing a conductive tape layer on the stage in the chamber;
Disposing a multilayer ceramic capacitor on the conductive tape layer;
Generating a plasma in the chamber by applying a pulse current to the solenoid coil;
Adjusting the voltage of the acceleration electrode including the cathode and the anode in the chamber from 12 kV to 13 kV;
Generating a pulse beam between the acceleration electrodes;
Wherein the pulse beam is spirally accelerated by a solenoid coil and irradiated to the multilayer ceramic capacitor on the stage.
The method according to claim 6,
Wherein the conductive tape layer comprises a carbon tape.
8. The method of claim 7,
Wherein a plurality of multilayer ceramic capacitors are disposed on the conductive tape layer at a predetermined interval.
The method according to claim 6,
Wherein the control unit adjusts the voltage of the solenoid coil to 0.5 to 1.5 kV to adjust the radius of rotation of the pulse beam accelerating electrons.
The method according to claim 6,
And controlling the electron gun and the stage to control the pulse beam to be irradiated to a termination portion of the multilayer ceramic capacitor.
The method according to claim 6,
Further comprising the step of coating the surface of the multilayer ceramic capacitor irradiated with the pulse beam.

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