KR102392305B1 - Multilayer ceramic substrate for high frequency and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a multilayer ceramic substrate for high frequency, wherein the multilayer ceramic substrate for high frequency according to the present invention includes a first thin ceramic plate, a second thin ceramic plate disposed on top of the first thin ceramic plate, and an upper portion of the second thin ceramic plate. A multilayer ceramic substrate comprising a third ceramic thin plate disposed on the third ceramic thin plate, and a fourth ceramic thin plate disposed on the third ceramic thin plate, wherein a first conductive pattern is printed on the upper surface of the first ceramic thin plate, and the second A second conductive pattern is printed on the upper surface of the thin ceramic plate, a third conductive pattern is printed on the lower surface of the fourth thin ceramic plate, and a fourth conductive pattern is printed on the upper surface of the fourth thin ceramic plate, and the fourth conductive pattern is printed on the upper surface of the thin ceramic plate. A space filled with air or a material having a low dielectric constant is formed in at least one of the second thin ceramic plate and the third thin ceramic plate, the first conductive pattern and the third conductive pattern form a ground electrode, and the second conductive pattern comprises: to form a signal electrode.

Description

Multilayer ceramic substrate for high frequency and manufacturing method thereof

The present invention relates to a multilayer ceramic substrate for high frequency use and a method for manufacturing the same, and to a multilayer ceramic substrate for high frequency use and a method for manufacturing the same, which remarkably reduces transmission delay and transmission loss.

A high-frequency semiconductor device, which is the core of mobile communication technology, is a generic term for semiconductor devices manufactured using a semiconductor process among high-frequency devices used in high-frequency systems that can process high-frequency band signals above the GHz band at high speed.

In order to accommodate a large-scale communication capacity, the frequency used gradually increased, and a high-performance and high-speed communication system was required, which further emphasized the necessity of a high-speed high-frequency semiconductor device. The wireless communication technology is advancing as services using new technologies are provided year after year. The first generation is analog mobile communication, the second generation is digital mobile communication, and the third generation is 5G next generation communication is developing Therefore, it is essential to develop a system that can provide next-generation communication services such as 5G and 6G, but it can be said that the first priority is the self-development of each high-frequency semiconductor device constituting such a system.

On the other hand, when the wiring width is reduced in the ultra-high density integrated semiconductor device, the RC delay increases due to the resistance and the capacitance (C) of the metal wiring, thereby reducing the overall operating speed of the semiconductor device. Occurs. As a method to solve this problem, a method of lowering the resistance value by increasing the electrical conductivity of the metal, a method of lowering the capacitance by reducing the dielectric constant of a dielectric disposed between wirings, etc. have been proposed, but there are still many problems that need to be improved there is. For example, an oxide-based dielectric having a low dielectric constant has a limit in lowering the dielectric constant due to the properties of the material itself, and may lead to a decrease in electrical performance due to bonding with a metal wiring.

Korean Intellectual Property Office Registered Patent Publication No. 10-0916075 Korean Intellectual Property Office Registered Patent Publication No. 10-0896600

An object of the present invention to solve the above problems is to form a space in a thin ceramic plate disposed between a ground electrode and a signal electrode to form a dielectric in a multilayer ceramic substrate formed by stacking a plurality of thin ceramic plates, and air and To provide a multilayer ceramic substrate for high frequency use, which reduces the dielectric constant of a dielectric by filling a material with a low dielectric constant and thus has a low capacitance, and a method for manufacturing the same.

In order to achieve the above object, a multilayer ceramic substrate for high frequency according to an embodiment of the present invention includes a first thin ceramic plate, a second thin ceramic plate disposed on the first thin ceramic plate, and an upper portion of the second thin ceramic plate. A multilayer ceramic substrate comprising a third ceramic thin plate disposed on the third ceramic thin plate, and a fourth ceramic thin plate disposed on the third ceramic thin plate, wherein a first conductive pattern is printed on the upper surface of the first ceramic thin plate, and the second A second conductive pattern is printed on the upper surface of the thin ceramic plate, a third conductive pattern is printed on the lower surface of the fourth thin ceramic plate, and a fourth conductive pattern is printed on the upper surface of the fourth thin ceramic plate, and the fourth conductive pattern is printed on the upper surface of the thin ceramic plate. A space filled with air or a material having a low dielectric constant is formed in at least one of the second thin ceramic plate and the third thin ceramic plate, the first conductive pattern and the third conductive pattern form a ground electrode, and the second conductive pattern comprises: to form a signal electrode.

Preferably, the second thin ceramic plate is composed of a 2-1 ceramic thin plate, and a 2-2 second ceramic thin plate disposed on the 2-1 thin ceramic plate, and the third ceramic thin plate is a 3-1 It is composed of a thin ceramic plate, and a 3-2 thin ceramic plate disposed on the 3-1 thin ceramic plate.

Preferably, a space filled with air or a material having a low dielectric constant is formed in the thin ceramic plate 2-1 and the thin ceramic plate 3-2.

Preferably, a space filled with air or a material having a low dielectric constant is formed in the 2-1 thin ceramic plate, the 3-1 thin ceramic plate, and the 3-2 thin ceramic plate.

Preferably, an insulator including a glass component is applied to the exposed surface of the ground electrode or the signal electrode exposed to the air by the space, and the thickness of the insulator is 1 to 100 microns.

A method of manufacturing a multilayer ceramic substrate for high frequency according to another embodiment of the present invention includes: printing a first conductive pattern on an upper surface of a first thin ceramic plate; forming a space in a second thin ceramic plate and printing a second conductive pattern on the upper surface of the second thin ceramic plate, and then disposing the second thin ceramic plate on the first thin ceramic plate; forming a space in a third thin ceramic plate and arranging the third thin ceramic plate on top of the second thin ceramic plate; and printing a third conductive pattern on the lower surface of the fourth ceramic thin plate and printing the fourth conductive pattern on the upper surface of the fourth thin ceramic plate, and then disposing the fourth thin ceramic plate on the third ceramic thin plate. Including, wherein the space formed in the second thin ceramic plate and the third thin ceramic plate is filled with air or a material having a low dielectric constant, the first conductive pattern and the third conductive pattern form a ground electrode, The two conductive patterns form a signal electrode.

In the present invention, in a multilayer ceramic substrate formed by stacking a plurality of thin ceramic plates, a space is formed in a thin ceramic plate disposed between a ground electrode and a signal electrode to form a dielectric, and air and/or a material having a low dielectric constant is filled in the formed space. Accordingly, it is possible to provide a multilayer ceramic substrate for high frequency use, which reduces the dielectric constant of the dielectric and thus has a low capacitance, and a method for manufacturing the same.

The present invention provides a high frequency multilayer ceramic substrate capable of remarkably reducing transmission delay and transmission loss by forming a space filled with air and/or a material having a low dielectric constant inside a dielectric even in a situation where a signal in a high frequency band needs to be processed, and a method for manufacturing the same can provide

1 is a view showing the structure of a multilayer ceramic substrate for high frequency according to an embodiment of the present invention.
2 is a view showing the structure of a multilayer ceramic substrate for high frequency use according to another embodiment of the present invention.
3 is a view showing the structure of a multilayer ceramic substrate for high frequency use according to another embodiment of the present invention.
4 is a diagram illustrating a structure of a multilayer ceramic substrate having no space portion according to an embodiment of the present invention.
5 is a diagram illustrating a structure of a high frequency multilayer ceramic substrate on which a plurality of signal electrodes are formed according to an embodiment of the present invention.
6 is a view showing a sequence of a method of manufacturing a multilayer ceramic substrate for high frequency according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to components in each drawing, it should be noted that the same components are given the same reference numerals as much as possible even though they are indicated in different drawings.

In the description of the embodiment of the present invention, if it is determined that a detailed description of a related known configuration or function interferes with the understanding of the embodiment of the present invention, the detailed description thereof will be omitted.

In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, or order of the elements are not limited by the terms.

1 to 5, the structure of the high frequency multilayer ceramic substrate according to an embodiment of the present invention will be described below.

1 is a diagram showing the structure of a high frequency multilayer ceramic substrate (hereinafter referred to as “the present multilayer ceramic substrate”) according to an embodiment of the present invention.

Referring to FIG. 1 , the sintered multilayer ceramic substrate includes a first thin ceramic plate 100 , a second thin ceramic plate 200 , a third thin ceramic plate 300 and/or a fourth thin ceramic plate 400 . .

The second thin ceramic plate 200 is disposed on the first thin ceramic plate 100 , the third thin ceramic plate 300 is disposed on the second thin ceramic plate 200 , and the fourth thin ceramic plate 400 is It is disposed on the third ceramic thin plate 300 . That is, the first thin ceramic plate 100 to the fourth thin ceramic plate 400 are laminated to form the multilayer ceramic substrate.

At this time, the thickness of the ceramic thin plates 100, 200, 300, 400 may be 10 to 500 microns (μm).

The first conductive pattern 10 is printed on the upper surface of the first thin ceramic plate 100 , the second conductive pattern 20 is printed on the upper surface of the second thin ceramic plate 200 , and the fourth thin ceramic plate 400 . ), the third conductive pattern 30 is printed on the lower surface, and the fourth conductive pattern 40 is printed on the upper surface of the fourth thin ceramic plate 400 . Here, the first conductive pattern 10 and the third conductive pattern 30 form a ground electrode and are electrically connected to the via hole 50 and grounded. In addition, the second conductive pattern 20 is electrically connected to a separate via hole (not shown) to form a signal electrode and is connected to an input signal.

At this time, the conductive patterns 10, 20, 30, and 40 are made of conductive paste. The conductive paste refers to a composite material in which conductor powder, binder, etc. are dispersed in a fluid resin solution. The conductor used may correspond to one or more of Ag, Cu, Au, Pd, Pt, Ag-Pd, Ni, Mo and W. The above-described conductive paste is also filled in the via hole 50 .

At least one of the second thin ceramic plate 200 and the third thin ceramic plate 300 is formed with a space (hereinafter, referred to as a “space portion” 60, 70) filled with air and/or a material having a low dielectric constant. The spaces 60 and 70 reduce the dielectric constant of the dielectric formed between the ground electrode and the signal electrode to lower the capacitance. When the capacitance is lowered, the transmission delay and transmission loss are greatly reduced. In this case, the space may be filled with air or other gas, and a low dielectric constant material or ceramic powder (powder) different from the substrate material may be filled. In addition, it is possible to control the dielectric constant by adjusting the material and/or the amount of the ceramic powder. Alternatively, a glass component may be included in the ceramic powder filled in the space, or a glass component as well as the ceramic powder may be additionally filled in the space. In this case, in the heat treatment process for bonding between the ceramic thin plates, the glass component filled in the space is liquefied and then hardened, so that the ceramic powder can be firmly fixed.

Meanwhile, the thickness of the spaces 60 and 70 may be 10 to 500 microns (μm).

According to an embodiment, the exposed surface of the ground electrode (or, according to the embodiment, the signal electrode may also correspond to this) exposed to air by the spaces 60 and 70 formed inside the present high frequency multilayer ceramic substrate. An insulator containing a glass component may be applied to the surface to form a protective film. In this case, the thickness of the insulator (protective film) may be 1 to 100 microns.

Referring to FIG. 1 , the second thin ceramic plate 200 is composed of a 2-1 thin ceramic plate 210 and a 2-2 thin ceramic plate 220 disposed on the 2-1 thin ceramic plate 210 and , the third ceramic thin plate 300 is composed of a 3-1 thin ceramic plate 310 and a 3-2 thin ceramic plate 320 disposed on the 3-1 thin ceramic plate 310 . That is, the second thin ceramic plate 200 corresponds to a multilayer ceramic substrate on which the 2-1 thin ceramic plate 210 and the 2-2 thin ceramic plate 220 are stacked, and the third ceramic thin plate 300 is the third- 1 corresponds to a multilayer ceramic substrate in which the thin ceramic plate 310 and the 3-2 thin ceramic plate 320 are stacked.

In addition, the first space 60 is formed in the 2-1 th ceramic thin plate 210 , and the second space 70 is formed in the 3-2 th thin ceramic plate 320 .

Meanwhile, the capacitance is calculated by the following equation.

And, when two different materials are connected in series, the dielectric constant of the entire material connected in series is calculated by the following equation.

For example, referring to FIG. 1 , the area of the electrodes 10 and 20 in the multilayer ceramic substrate is constant, the distance between the signal electrode 20 and the ground electrode 10 is constant, and the relative permittivity of air is 1 And under the condition that the dielectric constant of the ceramic thin plate is 8, according to the above two equations, the capacitance between the signal electrode 20 and the ground electrode 10 is the first space 60 and the first space 60 ), it can be seen that the case in which air is filled is 1/9 of the case in which the first space part 60 does not exist. Accordingly, transmission delay and transmission loss are also improved depending on the presence or absence of the first gap 60 .

Furthermore, under the above-described conditions, the capacitance between the signal electrode 20 and the ground electrode 30 is similarly obtained when the second space portion 70 is present when the second space portion 70 does not exist. Since it is 1/9 level, the total capacitance of the present multilayer ceramic substrate is reduced to 1/9 level compared to the case in which these spaces do not exist by forming the first space portion 60 and the second space portion 70 . Able to know.

2 is a view showing the structure of a multilayer ceramic substrate for high frequency use according to another embodiment of the present invention.

Referring to FIG. 2 , unlike the embodiment of FIG. 1 , the second space portion 70 is formed over a 3-1 thin ceramic plate 310 and a 3-2 thin ceramic plate 320 . That is, a space portion is formed in each of the 3-1 thin ceramic plate 310 and the 3-2 thin ceramic plate 320 , and the formed space part is connected to each other to form the second space part 70 . Accordingly, the relative permittivity value between the ground electrode 30 and the signal electrode 20 has a relative permittivity value of 1 of air (when the second space 70 is filled with air), or in the embodiment of FIG. It has a smaller value than the relative permittivity between the ground electrode 30 and the signal electrode 20 .

That is, referring to FIG. 2 , the thickness of the second space portion 70 between the ground electrode 30 and the signal electrode 20 positioned at the upper part is the thickness of the ground electrode 10 and the signal electrode positioned at the lower part. By forming the first space portion 60 thicker than the thickness of the first space portion 60 between 20 , a multilayer ceramic substrate having a structure in which the electrodes face each other in a form in which the upper portion has a lower capacitance value than the lower portion may be formed.

3 is a view showing the structure of a multilayer ceramic substrate for high frequency use according to another embodiment of the present invention.

Referring to FIG. 3 , the second thin ceramic plate 200 includes a 2-1 thin ceramic plate 210 , a 2-2 thin ceramic plate 220 disposed on the 2-1 thin ceramic plate 210 , and a second thin ceramic plate 210 . 2-2 is composed of a 2-3th ceramic thin plate 230 disposed on an upper portion of the 2-2 thin ceramic plate 220 , and the third ceramic thin plate 300 includes a 3-1 thin ceramic plate 310 and a 3-1 thin ceramic plate It is composed of a 3-2 thin ceramic plate 320 disposed on the upper portion of the 310 , and a 3-3 thin ceramic plate 330 disposed on the 3-2 thin ceramic plate 320 . That is, the second thin ceramic plate 200 corresponds to a multilayer ceramic substrate on which the 2-1 thin ceramic plate 210, the 2-2 thin ceramic plate 220 and the 2-3 thin ceramic plate 230 are laminated, The thin ceramic plate 300 corresponds to a multilayer ceramic substrate on which the thin 3-1 ceramic plate 310 , the 3-2 thin ceramic plate 320 , and the 3-3 thin ceramic plate 330 are stacked.

In addition, the first space portion 60 is formed over the 2-1 th ceramic thin plate 210 and the 2-2 thin ceramic plate 220 , and the second space part 70 is the 3-2 th thin ceramic plate 320 . ) and 3-3 is formed over the ceramic thin plate 330 . That is, a space portion is formed in each of the 3-2 thin ceramic plate 320 and the 3-3 thin ceramic plate 330 , and the formed space part is connected to each other to form a second space part 70 , and the 2-1 ceramic thin plate Space portions are formed in each of the 210 and 2-2 thin ceramic plates 220 , and the formed spaces are connected to each other to form the first space portion 60 .

The multilayer ceramic substrate of FIG. 3 has the same structure as the multilayer ceramic substrate of FIG. 1 . However, the thickness of the space formed in the multilayer ceramic substrate is different. That is, the distance between the electrodes can be adjusted by changing the thickness of the space, and the value of the capacitance can be changed according to the distance between the electrodes.

4 is a diagram illustrating a structure of a multilayer ceramic substrate having no space portion according to an embodiment of the present invention.

Referring to FIG. 4, the dielectric constant between the ground electrodes 10 and 30 and the signal electrode 20 is the same as that of the thin ceramic plate, while the dielectric constant between the electrodes in this multilayer ceramic substrate of FIG. 1 is lower than that of the thin ceramic plate. Therefore, it can be said that the multilayer ceramic substrate of FIG. 4 has higher inter-electrode capacitance than the multilayer ceramic substrate of FIG. 1 .

5 is a diagram illustrating a structure of a high frequency multilayer ceramic substrate on which a plurality of signal electrodes are formed according to an embodiment of the present invention.

Referring to FIG. 5 , a plurality of signal electrodes 20 are formed between the first space portion 60 and the second space portion 70 formed in the multilayer ceramic substrate. In this case, the first space 60 and/or the second space 70 may be filled with air, a gas other than air, and/or a low dielectric constant material (which may be in the form of a powder) different from the material of the thin ceramic plate. . Meanwhile, the first space 60 , the second space 70 , the ground electrodes 10 , 30 , and the signal electrode 20 are formed by the method described above with reference to FIGS. 1 to 3 .

6 is a view showing a sequence of a method of manufacturing a multilayer ceramic substrate for high frequency according to an embodiment of the present invention.

Referring to FIG. 6 , the method of manufacturing a multilayer ceramic substrate includes printing a first conductive pattern on the upper surface of the first thin ceramic plate ( S100 ), forming a space in the second thin ceramic plate, and forming an upper portion of the second thin ceramic plate After printing a second conductive pattern on the surface, disposing the second thin ceramic plate on top of the first ceramic thin plate (S200), forming a space in the third ceramic thin plate and applying the third ceramic thin plate to the second ceramic After disposing on the top of the thin plate (S300) and/or printing a third conductive pattern on the lower surface of the fourth thin ceramic plate and printing the fourth conductive pattern on the upper surface of the fourth thin ceramic plate, the fourth thin ceramic plate and placing (S400) on the third thin ceramic plate. At this time, the space formed in the second and third thin ceramic plates is filled with air and/or a material having a low dielectric constant, the first conductive pattern and the third conductive pattern form a ground electrode, and the second conductive pattern is a signal to form an electrode.

Although not shown in the drawings, the present method for manufacturing a multilayer ceramic substrate includes forming a via hole 50 at an edge of the thin ceramic plate 100 . In this step, the thickness of the ceramic thin plate 100 may be 10 to 500 microns (μm), and the diameter of the via hole 50 may be 10 to 200 microns. The via hole 50 may be formed through a process such as laser irradiation, mechanical drilling, chemical etching, or the like.

Although not shown in the drawings, the method for manufacturing the multilayer ceramic substrate includes filling the via hole 50 formed in the ceramic thin plate 100 with a conductive paste and performing heat treatment. In this step, the conductive paste is filled in the via hole 50 of the thin ceramic plate 100 in order to electrically connect the ground electrode 10 to be formed on the first thin ceramic plate 100 later. Furthermore, the conductive paste in this step means a composite material in which a conductor powder, a binder, etc. are dispersed in a fluid resin solution. The conductors used in this conductive paste are Ag, Cu, Au, Pd, Pt, Ag- It may correspond to one or more of Pd, Ni, Mo and W. In this step, the heat treatment temperature varies depending on the melting point of the conductor used as the conductive paste, but when Ag is used as the conductive paste, the heat treatment temperature may correspond to 600°C to 900°C, preferably 800°C, in an atmospheric environment. there is. In this case, the term heat treatment refers to heating in order to impart the original function of the material within the range in which the properties of the material are not changed.

The method of manufacturing a multilayer ceramic substrate includes printing a first conductive pattern on an upper surface of a first thin ceramic plate ( S100 ). This step includes printing and heat treatment of the first conductive pattern. In this step, the first conductive pattern 10 is printed using a conductive paste. The conductor used in the conductive paste in this step may correspond to at least one of Ag, Cu, Au, Pd, Pt, Ag-Pd, Ni, Mo, and W. The thickness of the first conductive pattern 10 may be 1 to 10 microns. In this step, the heat treatment temperature varies depending on the melting point of the conductor used as the conductive paste, but when Ag is used as the conductive paste, the heat treatment temperature may correspond to 600°C to 900°C, preferably 800°C, in an atmospheric environment. there is. The first conductive pattern 10 forms a ground electrode, and is also printed on the upper surface of the via hole 50 to make electrical connection with the via hole 50 , and is also electrically connected to the ground electrode of another layer through the via hole 50 . .

In this method of manufacturing a multilayer ceramic substrate, a space is formed in a second thin ceramic plate, a second conductive pattern is printed on the upper surface of the second thin ceramic plate, and then the second thin ceramic plate is disposed on the first ceramic thin plate. Step S200 is included. In this step, the space portion 60 formed in the second thin ceramic plate 200 may be formed through processes such as laser irradiation, mechanical drilling, chemical etching, and the like. The second conductive pattern 20 is printed using a conductive paste, and the description of the conductive paste has been described above. The thickness of the second conductive pattern 20 may also be 1 to 10 microns. In addition, this step includes printing and heat treatment of the second conductive pattern 20 , and since the heat treatment temperature is set in the same manner as the heat treatment temperature of the first conductive pattern, a description thereof will be omitted. The second conductive pattern 20 constitutes a signal electrode, and is electrically connected to via holes (not shown) formed in upper and lower portions of the second conductive pattern 20, and is electrically connected to an input signal through the via holes (not shown). In addition, a via hole 50 is also formed in the second thin ceramic plate 200 , and the formed via hole 50 is electrically connected to the via hole 50 formed in the first thin ceramic plate 100 . When the second conductive pattern 20 is formed, the second thin ceramic plate 200 is laminated on the first thin ceramic plate 100 . At this time, the via hole 50 formed in each ceramic thin plate is electrically connected, and the space portion 60 is located above the first conductive pattern 10 and below the second conductive pattern 20 , so that the second ceramic A thin plate 200 is laminated on the first ceramic thin plate 100 .

The method of manufacturing a multilayer ceramic substrate includes forming a space in a third thin ceramic plate and arranging the third thin ceramic plate on top of the second thin ceramic plate (S300). In this step, the space portion 70 formed in the third ceramic thin plate 300 may be formed through processes such as laser irradiation, mechanical drilling, and chemical etching. In addition, a via hole 50 is also formed in the third ceramic thin plate 300 , and the formed via hole 50 is electrically connected to the via hole 50 formed in the first ceramic thin plate 100 and the second thin ceramic plate 200 . When the space portion 70 is formed, the third thin ceramic plate 300 is laminated on the second thin ceramic plate 200 . At this time, the third ceramic thin plate 200 is connected to the second thin ceramic plate 100 so that the via hole 50 formed in each ceramic thin plate is electrically connected, and the space part 70 is located on the second conductive pattern 20 . laminated on top of

In this method of manufacturing a multilayer ceramic substrate, a third conductive pattern is printed on the lower surface of a fourth thin ceramic plate, a fourth conductive pattern is printed on the upper surface of the fourth thin ceramic plate, and then the fourth ceramic thin plate is applied to the third ceramic plate. It includes a step (S400) of arranging on top of the thin plate. In this step, the third conductive pattern 30 and the fourth conductive pattern 40 are printed using a conductive paste, and the description of the conductive paste has been described above. The thickness of the third conductive pattern 30 and the fourth conductive pattern 40 may also be 1 to 10 microns. In addition, this step includes the process of printing and heat-treating the third conductive pattern 20 and the fourth conductive pattern 40, and the heat treatment temperature is set in the same manner as the heat treatment temperature of the first conductive pattern. omit The third conductive pattern 30 forms a ground electrode and is electrically connected to the via hole 50 formed under the third conductive pattern 30 and is also electrically connected to the ground electrode of another layer through the via hole 50 . do. In addition, a via hole 50 is also formed in the fourth thin ceramic plate 400 , and the formed via hole 50 is electrically connected to the via hole 50 formed in the thin ceramic plates. When the third conductive pattern 30 and the fourth conductive pattern 40 are formed, a fourth thin ceramic plate 400 is laminated on the third thin ceramic plate 300 . At this time, the via hole 50 formed in each thin ceramic plate is electrically connected, and the fourth ceramic is positioned so that the space portion 70 is positioned above the second conductive pattern 20 and positioned below the third conductive pattern 30 . The thin plate 400 is laminated on the third ceramic thin plate 300 .

The method for manufacturing a multilayer ceramic substrate includes applying a bonding agent to the cross-sections of thin ceramic plates (first to third thin ceramic plates), avoiding via holes. The bonding agent is also applied to the top of the conductive pattern and is made of a thin ceramic plate and a material that does not affect the conductive pattern. The bonding agent is used to bond the ceramic thin plates, and the bonding agent may be an inorganic material and/or an organic material, the inorganic material may include glass, ceramic, etc., and the organic material may include an epoxy, polyimide, and the like. The bonding agent later forms a bonding layer (not shown), and the thickness of the bonding layer may be 2 to 100 microns. According to another embodiment, the bonding agent may be applied only to the cross section of the ceramic thin plate avoiding the conductive pattern. This step is performed before laminating each ceramic sheet.

The method of manufacturing a multilayer ceramic substrate includes heat-treating a plurality of laminated ceramic thin plates. That is, the plurality of ceramic thin plates may be adhered to each other by heat-treating the plurality of laminated ceramic thin plates to melt the bonding agent applied to each end surface of the plurality of ceramic thin plates. In this step, the heat treatment temperature may vary depending on the melting point of the bonding agent, and in order to prevent melting of the conductive paste filled in the ceramic thin plate, printed conductive patterns and/or via holes during the heat treatment process, the melting point of the bonding agent The point may be lower than the melting point of the ceramic thin plate, the melting point of the conductive paste used for pattern printing, and the melting point of the conductive paste filled in the via hole. Therefore, in this step, an embodiment of the present invention may be heat-treated at a temperature higher than the melting point of the bonding agent and lower than the melting point of the ceramic thin plate and the melting point of the conductive paste.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein.

Comparative Example 1 (refer to FIG. 4, a multilayer ceramic substrate without a space portion)

A via hole having a diameter of 20 microns is formed through laser irradiation on the first thin ceramic plate 100 microns in thickness, and a conductive paste made of Ag is filled in the via hole, and the first ceramic plate made of Ag 10 micron thick on the lower surface of the first ceramic plate is formed. After the conductive pattern is printed, heat treatment is performed at a temperature of 800°C.

Thereafter, a second thin ceramic plate with a thickness of 100 microns is prepared, a via hole with a diameter of 20 micron is formed in the second thin ceramic plate through laser irradiation, a conductive paste made of Ag is filled in the via hole, and the lower surface of the second thin ceramic plate is A second conductive pattern made of Ag with a thickness of 10 microns is printed, and then heat-treated at a temperature of 800°C. Then, a second thin ceramic plate is laminated on top of the first thin ceramic plate.

After that, a third ceramic thin plate 100 microns thick is prepared, 20 microns via holes are formed, Ag conductive paste is filled in the via holes, and a third conductive pattern made of 10 micron thick Ag on the lower surface of the third ceramic thin plate. is printed, and a fourth conductive pattern made of Ag with a thickness of 10 microns is printed on the upper surface of the third ceramic thin plate, and then heat-treated at a temperature of 800°C. Then, a third ceramic thin plate is laminated on top of the second thin ceramic plate. Here, the dielectric constant of the ceramic thin plate is 8.0, and the density of Ag used as the conductive paste is 82%.

Through the above-described process, a multilayer ceramic substrate in which the first ceramic plate, the second thin ceramic plate, and the third thin ceramic plate are laminated is manufactured.

Example 1 (see Fig. 1)

A via hole 50 having a diameter of 20 microns is formed through laser irradiation on the first thin ceramic plate 100 having a thickness of 50 microns, and a conductive paste made of Ag is filled in the via hole 50, and the first ceramic plate 100 is A first conductive pattern 10 made of Ag with a thickness of 10 microns is printed on the upper surface, and then heat-treated at a temperature of 800°C.

Thereafter, a thin 2-1 ceramic plate 210 having a thickness of 50 microns is prepared, and a via hole 50 having a diameter of 20 microns is formed in the 2-1 thin ceramic plate 210 through laser irradiation, and a second -1 The space portion 60 is formed in the thin ceramic plate 210 . A conductive paste made of Ag is filled in the via hole and heat-treated at a temperature of 800°C. Then, a 2-1 thin ceramic plate is laminated on the first thin ceramic plate.

Thereafter, a 2-2 thin ceramic plate 220 having a thickness of 50 microns is prepared, a via hole 50 of 20 microns is formed, a conductive paste made of Ag is filled in the via hole 50, and a 2-2 thin ceramic plate 220 is formed. ), a second conductive pattern 20 made of Ag with a thickness of 10 microns is printed on the upper surface, and then heat-treated at a temperature of 800°C. Then, a 2-2 thin ceramic plate 220 is laminated on the 2-1 thin ceramic plate 210 .

Thereafter, a 3-1 thin ceramic plate 310 having a thickness of 50 microns is prepared, a via hole 50 of 20 microns is formed, a conductive paste made of Ag is filled in the via hole 50, and heat treatment is performed at a temperature of 800 degrees. Then, a 3-1 thin ceramic plate 310 is laminated on the 2-2 thin ceramic plate 220 .

Thereafter, a 3-2 thin ceramic plate 320 having a thickness of 50 microns is prepared and a via hole 50 having a diameter of 20 microns is formed in the 3-2 thin ceramic plate 320 through laser irradiation, and a third -2 The space portion 70 is formed in the thin ceramic plate 320 . A conductive paste made of Ag is filled in the via hole and heat-treated at a temperature of 800°C. Then, a 3-2 thin ceramic plate 320 is laminated on the 3-1 thin ceramic plate 310 .

Thereafter, a fourth ceramic thin plate 400 having a thickness of 100 microns is prepared, and a third conductive pattern 30 made of Ag 10 microns thick is printed on the lower surface of the fourth thin ceramic plate 400, and the fourth ceramic thin plate ( A fourth conductive pattern 40 made of Ag with a thickness of 10 microns is printed on the upper surface of 400) and heat-treated at a temperature of 800 degrees. Then, a fourth thin ceramic plate 400 is laminated on the 3-2 thin ceramic plate 320 .

Through the above-described process, a multilayer ceramic substrate in which the first thin ceramic plate, the 2-1 ceramic plate, the 2-2 thin ceramic plate, the 3-1 thin ceramic plate, the 3-2 thin ceramic plate, and the fourth ceramic thin plate are laminated was manufactured do. Here, the dielectric constant of the ceramic thin plate is 8.0, and the density of Ag used as the conductive paste is 82%.

Example 2 (refer to FIG. 2, a multilayer ceramic substrate designed in such a way that the upper space has a lower capacitance value than the lower space)

Prepare a 3-1 thin ceramic plate 310 with a thickness of 50 microns, form a via hole 50 of 20 microns through laser irradiation, and insert a space 70 in the 3-1 thin ceramic plate 320 through laser irradiation. to form A conductive paste made of Ag is filled in the via hole 50 and heat-treated at a temperature of 800°C. Then, a 3-1 thin ceramic plate 310 is laminated on the 2-2 thin ceramic plate 220 . Here, the dielectric constant of the ceramic thin plate is 8.0, and the density of Ag used as the conductive paste is 82%.

All processes other than the above-described processes were performed in the same manner as in Example 1 to prepare a multilayer ceramic substrate.

Example 3 (refer to FIG. 3, multilayer ceramic substrate with increased inter-electrode distance compared to Example 1)

All processes except that the thickness of the 2-1 ceramic thin plate 210 and the 3-2 thin ceramic plate 320 were 100 microns were performed in the same manner as in Example 1 to prepare a multilayer ceramic substrate. Here, the dielectric constant of the ceramic thin plate is 8.0, and the density of Ag used as the conductive paste is 82%.

A signal of 30 GHz frequency was input to each of the multilayer ceramic substrates according to Comparative Example 1, Example 1, Example 2, and Example 3, and transmission loss was measured.

As a result, the transmission loss of Comparative Example 1 was -7.35 dB, the transmission loss of Example 1 was -2.81 dB, the transmission loss of Example 2 was -2.18 dB, and the transmission loss of Example 3 was -2.38 dB.

Through the above experimental results, it was found that the transmission loss decreased when a space portion existed between the ground electrode and the signal electrode, and that the transmission loss decreased as the thickness of the space portion increased.

The protection scope of the present invention is not limited to the description and expression of the embodiments explicitly described above. In addition, it is added once again that the protection scope of the present invention cannot be limited due to obvious changes or substitutions in the technical field to which the present invention pertains.

100: first ceramic thin plate 200: second ceramic thin plate 210: 2-1 ceramic thin plate
220: 2-2 thin ceramic plate 300: Third ceramic thin plate 310: 3-1 thin ceramic plate
320: 3-2 thin ceramic plate 400: fourth thin ceramic plate 10: first conductive pattern
20: second conductive pattern 30: third conductive pattern 40: fourth conductive pattern
50: via hole 60: first space part 70: second space part

Claims (6)

A first ceramic thin plate, a second ceramic thin plate disposed on the first ceramic thin plate, a third ceramic thin plate disposed on the second ceramic thin plate, and a fourth ceramic thin plate disposed on the third ceramic thin plate A multilayer ceramic substrate comprising:
A first conductive pattern is printed on an upper surface of the first thin ceramic plate, a second conductive pattern is printed on an upper surface of the second thin ceramic plate, and a third conductive pattern is printed on a lower surface of the fourth thin ceramic plate, , a fourth conductive pattern is printed on the upper surface of the fourth ceramic thin plate,
A space filled with air or a material having a lower dielectric constant than that of the substrate is formed in at least one of the second thin ceramic plate and the third thin ceramic plate,
The first conductive pattern and the third conductive pattern form a ground electrode, and the second conductive pattern forms a signal electrode,
The second thin ceramic plate is composed of a 2-1 thin ceramic plate and a 2-2 thin ceramic plate disposed on top of the 2-1 thin ceramic plate,
The third thin ceramic plate is composed of a 3-1 thin ceramic plate and a 3-2 thin ceramic plate disposed on the 3-1 thin ceramic plate,
In the 2-1 ceramic thin plate,
A first space filled with a material having a lower dielectric constant than the substrate material is formed,
The air-filled space portion is formed in each of the 3-1 thin ceramic plate and the 3-2 thin ceramic plate,
The space portions formed in each of the 3-1 thin ceramic plate and the 3-2 thin ceramic plate are connected to each other to form a second space,
The second space portion is formed to be thicker than the first space portion, so that the capacitance value between the ground electrode and the signal electrode formed by the third conductive pattern is determined by the ground electrode formed by the first conductive pattern and the signal. have a lower capacitance value than the inter-electrode capacitance value,
Via holes are formed at edges of the first thin ceramic plate, the second thin ceramic plate, and the third thin ceramic plate,
After the conductive paste is filled in the via holes formed in the first thin ceramic plate, the second thin ceramic plate and the third thin ceramic plate, heat treatment is performed,
The first conductive pattern, the second conductive pattern, the third conductive pattern and the fourth conductive pattern are heat-treated after being printed,
A bonding agent is applied to the upper surfaces of the first thin ceramic plate, the 2-1 ceramic plate, the 2-2 thin ceramic plate, the 3-1 thin ceramic plate, and the 3-2 thin ceramic plate, respectively, avoiding the via hole. After being placed,
The multilayer ceramic thin plate is higher than the melting point of the bonding agent, and lower than the melting point of the first ceramic plate, the second ceramic plate, the third ceramic plate and the fourth thin ceramic plate and the melting point of the conductive paste. The first thin ceramic plate, the second thin ceramic plate, the third thin ceramic plate, and the fourth thin ceramic plate are adhered to each other through a heat treatment process that is heat-treated at a temperature;
In the interior of the first space, a glass component is further included, and the glass component is liquefied in the heat treatment process and then hardened,
An insulator containing a glass component is coated on an exposed surface of the ground electrode or the signal electrode exposed to the air filled in the second space, and the insulator has a thickness of 1 to 100 microns, characterized in that for multilayer ceramic substrates. delete delete delete delete A method for manufacturing a multilayer ceramic substrate for high frequency, the method comprising:
printing a first conductive pattern on the upper surface of the first thin ceramic plate;
forming a space in a second thin ceramic plate, printing a second conductive pattern on an upper surface of the second thin ceramic plate, and then disposing the second thin ceramic plate on top of the first thin ceramic plate;
forming a space in a third thin ceramic plate and arranging the third thin ceramic plate on top of the second thin ceramic plate; and
Printing a third conductive pattern on the lower surface of the fourth thin ceramic plate and printing the fourth conductive pattern on the upper surface of the fourth thin ceramic plate, and then disposing the fourth thin ceramic plate on the upper surface of the third thin ceramic plate includes,
Each of the spaces formed in the second thin ceramic plate and the third thin ceramic plate is filled with air or a material having a lower dielectric constant than that of the substrate material,
The first conductive pattern and the third conductive pattern form a ground electrode, and the second conductive pattern forms a signal electrode,
The second thin ceramic plate is composed of a 2-1 thin ceramic plate and a 2-2 thin ceramic plate disposed on top of the 2-1 thin ceramic plate,
The third thin ceramic plate is composed of a 3-1 thin ceramic plate and a 3-2 thin ceramic plate disposed on the 3-1 thin ceramic plate,
A first space portion filled with a material having a lower dielectric constant than that of the substrate is formed in the 2-1 ceramic thin plate,
The air-filled space portion is formed in each of the 3-1 thin ceramic plate and the 3-2 thin ceramic plate,
The space portions formed in each of the 3-1 thin ceramic plate and the 3-2 thin ceramic plate are connected to each other to form a second space,
The second space portion is formed to be thicker than the first space portion, so that the capacitance value between the ground electrode and the signal electrode formed by the third conductive pattern is determined by the ground electrode formed by the first conductive pattern and the signal. have a lower capacitance value than the inter-electrode capacitance value,
The method, before the step of printing the first conductive pattern on the upper surface of the first ceramic thin plate,
forming via holes at edges of the first thin ceramic plate, the second thin ceramic plate, and the third thin ceramic plate; and
The method further comprising: filling via holes formed in the first thin ceramic plate, the second thin ceramic plate, and the third thin ceramic plate with a conductive paste and performing heat treatment;
The step of printing the first conductive pattern on the upper surface of the first ceramic thin plate includes a process of heat-treating the printed first conductive pattern,
The step of forming a space in the second thin ceramic plate and printing a second conductive pattern on the upper surface of the second thin ceramic plate and then disposing the second thin ceramic plate on the top of the first thin ceramic plate is the second ceramic Before disposing the thin plate on the first thin ceramic plate, a process of heat-treating the printed second conductive pattern,
Printing a third conductive pattern on the lower surface of the fourth thin ceramic plate and printing a fourth conductive pattern on the upper surface of the fourth thin ceramic plate, and then disposing the fourth thin ceramic plate on top of the third thin ceramic plate includes the process of heat-treating the printed third conductive pattern and the fourth conductive pattern before disposing the fourth ceramic thin plate on the third ceramic thin plate,
The step of forming a space in the second thin ceramic plate and printing a second conductive pattern on the upper surface of the second thin ceramic plate and then disposing the second thin ceramic plate on the top of the first thin ceramic plate is the second ceramic Before disposing the thin plate on the first thin ceramic plate, the bonding agent is applied to the upper surface of the first thin ceramic plate and the upper surface of the 2-1 thin ceramic plate avoiding the via hole,
Forming a space in the third thin ceramic plate and arranging the third thin ceramic plate on the second thin ceramic plate includes, before placing the third ceramic thin plate on the second thin ceramic plate, the second - Applying a bonding agent to the upper surface of the thin ceramic plate and the upper surface of the thin ceramic plate 3-1 avoiding the via hole,
Printing a third conductive pattern on the lower surface of the fourth thin ceramic plate and printing a fourth conductive pattern on the upper surface of the fourth thin ceramic plate, and then disposing the fourth thin ceramic plate on the third thin ceramic plate Before disposing the fourth ceramic thin plate on top of the third ceramic thin plate, applying a bonding agent to the upper surface of the 3-2 thin ceramic plate avoiding the via hole,
In the method, a third conductive pattern is printed on the lower surface of the fourth thin ceramic plate and a fourth conductive pattern is printed on the upper surface of the fourth thin ceramic plate, and then the fourth ceramic thin plate is applied to the upper surface of the third ceramic thin plate. After the step of disposing, further comprising the step of heat-treating the multilayer ceramic substrate comprising the first ceramic plate, the second thin ceramic plate, the third thin ceramic plate, and the fourth thin ceramic plate, which are respectively arranged and stacked,
The step of heat-treating the multilayer ceramic substrate is higher than the melting point of the bonding agent, and the melting points of the first ceramic plate, the second ceramic plate, the third ceramic plate, and the fourth thin ceramic plate, and the conductive paste. By heat-treating the multilayer ceramic substrate at a temperature lower than the melting point, the first thin ceramic plate, the second thin ceramic plate, the third thin ceramic plate, and the fourth thin ceramic plate are adhered to each other;
In the interior of the first space, a glass component is further included so that the glass component is liquefied and then cured in the heat treatment of the multilayer ceramic substrate,
An insulator containing a glass component is coated on an exposed surface of the ground electrode or the signal electrode exposed to the air filled in the second space, and the insulator has a thickness of 1 to 100 microns, characterized in that A method for manufacturing a multilayer ceramic substrate for

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