KR100981299B1 - Manufacturing method of unfired ceramic hybrid substrate - Google Patents

Abstract

The present invention relates to a method for producing an anisotropic ceramic hybrid thick film substrate, comprising the steps of preparing an ink composition comprising ceramic powder suspended in a solvent, a polymer resin, and a dispersant, and using droplets of the ink composition as ink jets. Forming a thick film by spraying on a substrate, forming a self-array of the ceramic molecules by evaporation of the solvent in the thick film, and filling the polymer resin in the arranged internal space, and Curing to form an unfired ceramic hybrid thick film substrate. At this time, the polymer resin is a thermosetting resin or a thermoplastic resin.

Ceramic Hybrid Composites, Inkjet, Plasticless Ceramics

Description

Manufacturing method of non-fired ceramic hybrid thick film substrate {MANUFACTURING METHOD OF UNFIRED CERAMIC HYBRID SUBSTRATE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a ceramic thick film substrate. In particular, an ink-free ceramic hybrid thick film in which a firing process is omitted by spraying an ink composition composed of ceramic powder and a polymer resin suspended in a solvent with an ink jet to form a coating layer. It relates to a method for manufacturing a substrate.

delete

Under the ubiquitous environment, we seek to improve convenience and efficiency by communication between things and people anytime and anywhere for remote medical care or environmental monitoring. For this purpose, not only complex, miniaturized, lightweight, and high performance of electronic components are required, but signal delay and signal loss due to high frequency wireless communication must be minimized.

As described above, the signal loss generated during high frequency communication is proportional to the dielectric tangent (tan δ), which is the inverse of the quality factor Q, which is a characteristic of the dielectric used as the electronic component substrate, and is also proportional to the square root of the dielectric constant thereof, thereby minimizing the loss. In order to achieve this, the dielectric must be made of a material having a particularly small dielectric loss tangent. However, the FR-4 polymer material used as a general substrate material has a relatively large dielectric loss and thus has a limitation in lowering the dielectric loss tangent. Therefore, a ceramic material having a dielectric loss tangent of 1/10 or less of the polymer material is desired.

Such ceramic substrates are usually laminated with a plurality of thick film substrates on which a plurality of internal electrodes are printed and co-fired with the electrodes, and used for high temperature cofired ceramic (HTCC) and low temperature cofired ceramics according to the firing temperature. (Low Temperature Cofired Ceramics: LTCC).

However, in the case of HTCC containing alumina (Al ₂ O ₃ ) and the like, the sintering is not only possible at high temperatures, but also must be sintered at a high temperature of 1500 ° C. or higher in a reducing atmosphere to prevent oxidation of the electrode. Since the metal electrode material is melted at such a high temperature, there is a problem that only the high temperature baking electrode material such as tungsten should be used for the simultaneous firing. In addition, this also involves the problem of the resistance value of the tungsten electrode and the cost problem for firing the high temperature atmosphere.

In contrast, LTCC, which is currently being developed, has a relatively low sintering temperature (for example, it can be fired in an air atmosphere of 900 ° C. or lower when using an Ag electrode, and around 950 ° C. when using a Cu electrode. It can be fired in a reducing atmosphere), and it is possible to co-fire with them by using Cu and Ag for low temperature firing as internal electrodes.

However, since LTCC is still essential, the sintering process is still essential. Thus, in the manufacture and sintering of a green sheet through a conventional casting process, a large amount of organic materials included in the green sheet are thermally decomposed to cause volume shrinkage of the ceramic. do. This is not suitable for the realization of fine patterns of several tens of micrometers which are currently required in printed circuits due to the trend of thinning and miniaturization of integrated modules.

Accordingly, the present invention was devised to solve the above problems, and an object of the present invention is to prepare an ink composition composed of ceramic powder and a polymer resin and spray the same with an inkjet to prepare a thick film substrate, thereby performing a heat treatment process such as baking. Provided is a method for manufacturing an unfired ceramic hybrid thick film substrate which eliminates the volume shrinkage problem.

As a feature of the present invention for achieving the above object, a method for producing an anisotropic ceramic hybrid thick film substrate according to one aspect of the present invention is to prepare an ink composition comprising a ceramic powder suspended in a solvent, a polymer resin and a dispersant Forming a thick film by spraying droplets of the ink composition onto the substrate by an ink jet, and self-arrangement of the ceramic molecules is formed by the evaporation of the solvent in the thick film, and the arranged interior The method may include filling the space with the polymer resin, and curing the polymer resin to form an unfired ceramic hybrid thick film substrate. At this time, the polymer resin is a thermosetting resin or a thermoplastic resin.

delete

delete

According to the present invention, by manufacturing a ceramic hybrid thick film substrate by inkjet spraying ink of ceramic powder and resin composition, the heat treatment process for baking can be omitted, and a thin layer can be achieved. Very suitable. In addition, such a thick film substrate is in the form of a kind of composite to maintain the low loss characteristics inherent to the ceramics as it is, as well as its inherent brittleness has excellent characteristics resistant to impact. In addition, since the firing process is excluded, not only the manufacturing cost of the module is reduced, but also the dimensional stability is excellent, making it easy to manufacture a highly integrated module having a fine pattern.

Hereinafter, the present invention will be described in detail.

The ceramic hybrid composite according to the present invention may be prepared by spraying an ink composition composed of ceramic powder and a polymer resin with an ink jet to form a coating layer. As a result, the high temperature heat treatment for the firing of the ceramic is completely excluded from the manufacturing process so that the shrinkage of the ceramic substrate due to the heat treatment is not accompanied.

1 shows a conceptual diagram thereof.

An inkjet process according to an embodiment of the present invention will be briefly described with reference to FIG. 1. First, when an ink composition in which ceramic powder and a polymer resin are mixed with a predetermined solvent is sprayed onto a predetermined substrate with an ink jet (first step), the droplets formed on the substrate are fluids due to spontaneous evaporation of the solvent. The convection phenomenon leads to the formation of a self-aligned array of high-density ceramic molecules (second step). Then, the polymer resin is filled in the ceramic powder internal space in which ceramic particles are regularly arranged (third step), and then a ceramic hybrid composite substrate is manufactured by curing the resin (fourth step). The ceramic hybrid composite thus prepared retains the intrinsic dielectric properties of the ceramics without additional sintering process, and also reduces the stress of the ceramic whose internal resin is the main component, thereby reducing the inherent brittleness of the ceramics, thereby making it more resistant to impact.

2 and 3 are schematic process diagrams for explaining the manufacturing method according to two preferred embodiments of the present invention.

First, a preferred embodiment of the present invention will be described with reference to FIG. 2, in which the ink composition for the inkjet process is mainly composed of ceramic powder suspended in a solvent (S201).

At this time, the solvent is water, ethanol (ethanol), diethylene glycol (DiethyleneGlycol: DEG), formamide (FA), α-terpineol (TP), γ-butyrolactone (γ-butylrolactone: BL), methylcellosolve (MCS), propylmethylcellosolve (PM), or a combination thereof, but are not limited thereto.

In addition, the composition of the ceramic powder may include all dielectric compositions suitable for the intended properties. For example, in one embodiment of the present invention, in order to impart functionality as a communication device substrate, BaTiO ₃ based ceramics and SrTiO ₃ based ceramics may be used. , PbTiO ₃ -based ceramics, ferrite ceramics, and Pb (Zr, Ti) O ₃ -based ceramics. In addition, the ceramic powder has a particle size of preferably 0.1-0.7 μm, very preferably 0.1-0.5 μm. In addition, the particle concentration of the ceramic powder is preferably 10-50 vol%.

In addition, the ink composition may be added to the dispersing agent to 5 vol% or less for controlling the surface tension thereof, examples of the dispersing agent is a nonionic surfactant, cationic surfactant, anionic surfactant, octyl alcohol (actyl alcohol), acrylic type It includes any one or more of the polymer, but is not limited thereto.

In addition, the ink composition may include a resin composition filled in the space between the ceramic powders. The resin includes a thermosetting resin or a thermoplastic resin, and examples thereof include polyacrylate resins, epoxy resins, phenolic resins, polyamides resins, and polyimide resins. (polyimides rein), unsaturated polyesters resin, polyphenylene ether resin (PPE), polyphenilene oxide resin (PPO), polyphenylene sulfide resin (polyphenylenesulfides) resins, cyanate ester resins, benzocyclobutene (BCB), or combinations thereof, but are not limited thereto, and any other thermosetting resin may be used in the present invention. At this time, the resin composition is to maintain the ceramic fraction while maintaining a minimum distribution of the internal space of the ceramic powder, 5-50 vol%, preferably 5-20 vol% is added. In addition, according to another preferred embodiment of the present invention, as shown in FIG. 3, the resin composition is added to the ink composition and is not sprayed at the same time, but may be separately prepared and inkjet sprayed (S303).

In addition, the ceramic ink may further include any one or more binders of an epoxy resin, an acrylic resin, polyurethane, and a polyester resin.

Thereafter, the ink composition is inkjet sprayed onto a predetermined substrate, foil, or film to form a uniform film, and then dried and heat treated to cure the resin contained in the uniform film, thereby completing a ceramic hybrid composite substrate (S202-). S205). In this case, the substrate, foil or film may be a polymer film such as a Si semiconductor substrate, Cu foil, or a PET film that is separated and removable. In addition, a lower electrode, which is a predetermined metal conductor, is printed on the substrate before the spraying, and the spraying may be performed on the lower electrode.

In addition, the heat treatment temperature for curing of the resin is approximately 300 ℃ or less, it is preferable to vary depending on the resin composition used. For example, it may be about 300 ° C. for BCB resin, about 140-250 ° C. for PPE resin, about 150-250 ° C. for cyanate ester resin, and about 140-220 ° C. for epoxy resin.

Another preferred embodiment of the present invention is shown in Figure 3, which is composed of only the ceramic powder and the dispersant of the above-mentioned composition in which the original ink composition does not contain a resin (S301).

Then, the ink composition is inkjet sprayed to form a uniform film, and then the resin having the composition described above is inkjet sprayed on the uniform film (S302, S303). Thereby, the resin injected later is filled in the space in the ceramic powder which is already formed inside the said uniform film.

Thereafter, as in the exemplary embodiment of FIG. 2, the final uniform film is dried and cured to complete the ceramic hybrid composite substrate (S304).

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. However, the embodiments described below are provided to aid the overall understanding of the present invention, and the present invention is not limited thereto.

Example  One

In this embodiment, according to an embodiment of the present invention described above with reference to FIG. 3, an ink composition including ceramic powder, a mixed solvent, and a dispersant is prepared, and inkjet sprayed to form a uniform film, followed by A resin hybrid was sprayed on the resin to prepare a ceramic hybrid composite substrate having an alumina (Al ₂ O ₃ ) composition.

First, Al ₂ O ₃ After dispersing the particles (AKP-30, ShowaDenko) in the TP / MCS mixed solvent, the ink composition was prepared by milling. That is, 25 ml of TP and 75 ml of MCS are mixed with 100 ml of mixed solvent, 40 vol% of Al ₂ O ₃ particles and 1 vol% BYK-111 dispersant, and then 200 g of zirconia balls (φ 1 mm) are added and ball milled for 24 hours. It was milled at 2000 rpm for 6 minutes using a mixer (AR-250, Thinky). The final composition obtained was a white suspension. After spraying this ink composition on the silicon substrate in which the Au lower electrode was formed using the inkjet, it confirmed that the uniform film was formed. At this time, it was sprayed in an area of 12 x 12 (mm) at intervals of 120 ㎛, the thickness of the substrate formed by five times and 10 times repeated in the number of injection was 5.12 ㎛ (5 times) and 8.03 ㎛ (10 times). After inkjetting the PPO solution on the alumina thick film thus prepared, heat treatment was performed at 250 ° C. for 3 hours to prepare a thick film having enhanced loss characteristics and brittleness.

4 is a photograph of the alumina thick film prepared in this embodiment, Figures 5a and 5b is a cross-sectional electron micrograph of the alumina thick film formed according to the number of times (5 and 10 times) of the ink composition in the present embodiment.

Example  2

In this embodiment, a ceramic hybrid composite substrate having an alumina composition was manufactured according to the embodiment of the present invention as described above with reference to FIG. 3.

First, Al ₂ O ₃ After dispersing the particles (ASFP-20, Denka) and BYK-111 in the TP / MCS solvent, the ink composition was prepared by milling. That is, after mixing 40 vol% Al ₂ O ₃ particles and 1 vol% BYK-111 dispersant in 100 ml of TP and 25 ml of 75 ml mixed solution of MCS, 200 g of zirconia balls (φ1 mm) were added and ball milled for 24 hours. Using a mixer (AR-250, Thinky) was milled at 2000 rpm for 6 minutes. The final composition obtained was a white suspension. The ink composition was sprayed onto the silicon substrate in the same manner as in Example 1 using an inkjet, and then it was confirmed that a uniform film was formed. The PPO solution was ink jetted onto the alumina thick film thus prepared, and heat treated at 250 ° C. for 3 hours to prepare a thick film having enhanced loss characteristics and brittleness.

FIG. 6A is a cross-sectional electron micrograph of the alumina thick film prepared in this embodiment, and FIG. 6B is a surface electron micrograph thereof.

Example  3

In this embodiment, according to an embodiment of the present invention described above with reference to FIG. 2, an ink composition comprising ceramic powder, a mixed solvent, a dispersant, and a resin is prepared, and inkjet sprayed to form a uniform film to form an alumina composition. Ceramic hybrid composite substrates were prepared.

First, Al ₂ O ₃ Particles (ASFP-20, Denka Co., Ltd.), an epoxy resin, and BYK-111 were dispersed in a TP / MCS solvent to prepare an ink composition through milling. That is, after mixing 40 vol% Al ₂ O ₃ particles and 1 vol% BYK-111 dispersant in 100 ml of a mixed solvent of 25 ml of TP and 75 ml of MCS, 200 g of zirconia balls (φ1 mm) were added thereto, and a ball mill was used for 24 hours. Mixed. In order to reinforce the brittleness of the thick film and to improve the two types of bonding properties, a 19 vol% epoxy resin mixture was added thereto, followed by milling at 2000 rpm for 6 minutes using a mixer (AR-250, Thinky). The epoxy resin mixture is a mixture of Noblelock and Bromine epoxy resin KDB KDB YDB-400, YD-128, KBPN-120 6: 2: 2 after mixing the mass of the curing agent (bis-phenol A type, KBH- L2121) and a curing catalyst (2MI) were prepared by mixing in a mass ratio of 5.8: 4: 0.2. The final composition obtained was a pale yellow suspension. The ink composition was sprayed onto the silicon substrate in the same manner as in Example 1 using an inkjet, and then it was confirmed that a uniform film was formed. After drying 30 minutes in an oven at 150 ° C., heat treatment was performed at 200 ° C. for 3 hours to prepare a thick film having enhanced loss characteristics and brittleness.

FIG. 7A is a cross-sectional electron micrograph of the alumina thick film prepared in this embodiment, and FIG. 7B is a surface electron micrograph thereof.

Example  4

In this embodiment, as in Example 3, according to the embodiment of the present invention described above with reference to FIG. 2, a ceramic hybrid composite substrate having an alumina composition was manufactured.

First, Al ₂ O ₃ Particles (ASFP-20, Denka), PPO and BYK-111 were prepared by dispersing in TP / MCS solvent and then milling. That is, after mixing 40 vol% Al ₂ O ₃ particles and 1 vol% BYK-111 dispersant in 100 ml of a mixed solvent of 25 ml of TP and 75 ml of MCS, 200 g of zirconia balls (φ1 mm) were added and mixed using a ball mill for 24 hours. It was. In addition, 19 vol% PPO resin was added to reinforce the brittleness and dielectric loss characteristics of the thick film, and then milled at 2000 rpm for 6 minutes using a mixer (AR-250, Thinky). The final composition obtained was a white suspension. After spraying the ink composition on the silicon wiper in the same manner as in Example 1 using an inkjet, it was confirmed that a uniform film was formed. After drying 30 minutes in an oven at 150 ° C., heat treatment was performed at 250 ° C. for 3 hours to prepare a thick film having enhanced loss characteristics and brittleness.

Example  5

In this embodiment, as in Example 3, according to the embodiment of the present invention described above with reference to FIG. 2, a ceramic hybrid composite substrate having an alumina composition was manufactured.

First, Al ₂ O ₃ Particles (ASFP-20, Denka) and BCB and BYK-111 were prepared by milling after dispersing in TP / MCS solvent. That is, after mixing 40 vol% Al ₂ O ₃ particles, 19 vol% BCB resin, and 1 vol% BYK-111 dispersant to 100 ml of a mixed solvent of 25 ml of TP and 75 ml of MCS, 200 g of zirconia ball (φ1 mm) was added thereto for 24 hours. While mixing using a ball mill. In order to reinforce the brittleness and dielectric loss characteristics of the thick film, 19 vol% BCB resin was added, and then milled at 2000 rpm for 6 minutes using a mixer (AR-250, Thinky). The final composition obtained was a pale yellow suspension. After spraying this ink composition to the silicon wiper by the method similar to Example 1 using an inkjet, it confirmed that a uniform film was formed. After drying 30 minutes in an oven at 150 ° C., heat treatment was performed at 300 ° C. for 3 hours to prepare a thick film having enhanced loss characteristics and brittleness.

Comparative example  1-3 (alumina by casting Thick  Produce)

In Comparative Examples 1-3, the alumina thick film was manufactured by casting, and each composition of the paste for casting was shown in Table 1 below:

TABLE 1

Comparative example Al ₂ O ₃ Powder (g) PVB
Binder (g) Dispersant (g)
(BYK-111) Solvent (g)
(γ-butyrolactone) One 82 One 1.0 16 2 80 2 1.5 17.5 3 75 5 1.5 18.5

First, 200 g of zirconia balls (φ1 mm) were added to each composition to prepare a uniform paste, mixed by using a ball mill for 24 hours, and then milled at 2000 rpm for 6 minutes using a mixer (AR-250, Thinky). The Al ₂ O ₃ paste prepared in the present Comparative Examples composition was printed on a Cu foil using a 400mesh screen, and then the printed Al ₂ O ₃ layer was dried in an oven at 90 ° C. for 30 minutes, and 60-80 wt% of the solvent. The epoxy solution, which had been changed in concentration, was double printed on the Al ₂ O ₃ layer by using a 400mesh screen. The printed sample was dried in an oven at 90 ° C. for 10 minutes and then cured in an oven at 170 ° C. for 30 minutes to prepare an alumina thick film.

The filling density, dielectric loss tangent, dimensional deformation rate, and thermal conductivity of the thick alumina films prepared in Examples 1-5 and Comparative Examples 1-3, respectively, were measured and the results are shown in Table 2 below.

TABLE 2

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Fill rate (%) 55 65 52 55 55 40 37 35 Genetic tangency
(tanδ) 0.004 0.0035 0.005 0.004 0.002 0.012 0.015 0.02 Z axis
Dimensional strain (%) 0.2 0.1 0.2 0.2 0.2 3 5 6 Thermal conductivity
(W / mK) 3 3 2.3 2.4 2.2 1.3 1.1 1.2

Referring to Table 2, the various properties of the alumina hybrid thick film prepared in Examples 1-5 of the present invention, that is, low loss characteristics due to low dielectric loss tangent value, dimensional stability, and heat dissipation are compared by conventional casting It can be seen that it is much superior to the alumina thick film prepared in Example 1-3.

The characteristics of the preferred embodiments of the present invention described above may vary somewhat within the usual error range depending on the powder characteristics such as the average particle size, distribution and specific surface area of the composition powder, the purity of the raw material, the amount of impurity added and the sintering conditions. It is only natural for those with ordinary knowledge in the field.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, any person having ordinary skill in the art will be able to various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications, changes And additions should be regarded as within the scope of the claims.

1 is a conceptual diagram illustrating a manufacturing process of a ceramic hybrid composite according to the present invention.

Figure 2 is a process flow diagram for explaining the manufacturing method according to an embodiment of the present invention.

Figure 3 is a flow chart illustrating a manufacturing method according to another preferred embodiment of the present invention.

Figure 4 is a photograph of the alumina thick film prepared in Example 1 of the present invention.

FIG. 5A is a cross-sectional electron micrograph of a thick alumina film formed according to the number of jets of the ink composition (5 times) in Example 1 of the present invention. FIG.

FIG. 5B is a cross-sectional electron micrograph of a thick alumina film formed according to the number of injections of the ink composition (10 times) in Example 1 of the present invention. FIG.

Figure 6a is a cross-sectional electron micrograph of the alumina thick film prepared in Example 2 of the present invention.

Figure 6b is a surface electron micrograph of the alumina thick film prepared in Example 2 of the present invention.

Figure 7a is a cross-sectional electron micrograph of the alumina thick film prepared in Example 3 of the present invention.

Figure 7b is a surface electron micrograph of the alumina thick film prepared in Example 3 of the present invention.

Claims (16)

In the method for producing a non-fired ceramic hybrid thick film substrate, Preparing an ink composition comprising ceramic powder suspended in a solvent, a polymer resin, and a dispersant; Spraying the droplets of the ink composition onto the substrate with an ink jet to form a thick film; Forming a self-alignment of the ceramic molecules by evaporation of the solvent in the thick film and filling the polymer resin in the arranged internal space; Curing the polymer resin to form an unfired ceramic hybrid thick film substrate. delete The method of claim 1, The polymer resin is characterized in that the thermosetting resin or a thermoplastic resin. The method of claim 3, The polymer resin may be a polyacrylate resin, an epoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, or an unsaturated polyester resin. unsaturated polyesters resin, polyphenylene ether resin (PPE), polyphenilene oxide resin (PPO), polyphenylenesulfides resin, cyanate ester resin , Benzocyclobutene (BCB), or a combination thereof. delete The method of claim 1, The solvent is water, ethanol (ethanol), diethylene glycol (DEG), formamide (FA), α-terpineol (TP), γ-butyrolactone (γ-butylrolactone: BL), methylcellosolve (MCS), propylmethylcellosolve (PM), or a combination thereof. The method of claim 1, The dispersing agent is characterized in that it comprises one or more selected from the group consisting of nonionic surfactants, cationic surfactants, anionic surfactants, octyl alcohol and acrylic polymer. The method of claim 1, The ink composition further comprises at least one binder selected from the group consisting of epoxy resins, acrylic resins, polyurethane resins and polyester resins. The method of claim 1, The particle size of the ceramic powder is characterized in that 0.1 to 0.7 ㎛. The method of claim 1, Particle concentration of the ceramic powder is characterized in that 10 to 50 vol% compared to the ink composition. The method of claim 1, The polymer resin is characterized in that it comprises 5 to 50 vol% compared to the ink composition. The method of claim 1, The dispersant is greater than 0 compared to the ink composition, characterized in that included in the range of 5 vol% or less. The method of claim 1, The composition of the ceramic powder is characterized in that it comprises at least one selected from the group consisting of BaTiO ₃ ceramics, SrTiO ₃ ceramics, PbTiO ₃ ceramics and ferrite, Pb (Zr, Ti) O ₃ ceramics. The method of claim 1, Wherein said substrate is a Si substrate, a Cu foil, or a separate removable PET film. The method of claim 1, And said curing treatment comprises a heat treatment process. delete

Images