KR101630826B1 - manufacturing method of high strength ceramic sheet for firing electronic ceramic and high strength ceramic sheet manufactured by the same - Google Patents

Abstract

A method of manufacturing an electron ceramic fired high strength ceramic substrates and therefore relates to a high strength ceramic substrate for a microwave ceramic sintering is produced by method of manufacturing a high strength ceramic substrate for a microwave ceramic sintering according to the invention are: alumina (Al ₂ O _3), (A) a raw material mixing step of a mixture consisting of yttria-stabilized zirconia (YSZ) and a binder; (B) defoaming and aging the mixed mixture through the step (a); (C) molding the mixture obtained through the step (b) by a thick film molding process; (D) performing lamination and warm-isostatic pressing (WIP) on the molded article molded in the step (c); (E) cutting the formed body after step (d) and sintering the cut body in an electric furnace at a temperature range of 1400 to 1600 ° C.
Accordingly, there is provided a method of manufacturing a high-strength ceramic substrate for electronic ceramic firing, which can produce a high-strength ceramic substrate for electronic ceramic firing such as a setter having a low reactivity with an object to be cleaned at low cost at a low cost, A high strength ceramic substrate can be provided.

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a high strength ceramic substrate for electronic ceramic firing and a high strength ceramic substrate for firing the same,

TECHNICAL FIELD The present invention relates to a method of manufacturing a high strength ceramic substrate for electronic ceramic firing and a high strength ceramic substrate for firing an electronic ceramic manufactured thereby. More particularly, the present invention relates to a high strength ceramic substrate for electronic ceramic firing And a high-strength ceramic substrate for electronic ceramic firing produced by the method.

The sintering process of electronic device parts and injection molded products is a very important process that determines the characteristics of the product. At this time, the setter used in the sintering furnace has a function of removing the organic material (binder) And it is an important firing member that determines the quality of the product by taking charge of the uniform dispersion of the product and easy discharge to the outside.

Such a setter is a high strength ceramic substrate for electronic ceramic firing and is required to have heat shock resistance and bending strength in order to increase the service life. Particularly, it is required to suppress the green sheet and the surface reaction by the constituent elements of the setter and the fired body It tends to be developed in accordance with the substance of the object to be fired and the method of firing.

An example of a method of manufacturing a ceramic substrate using a setter is disclosed in Korean Patent Registration No. 10-1070148 (registered on September 27, 2011, hereinafter referred to as "Patent Document 1").

On the other hand, in recent years, the demand for magnetic sheets for NFC (Near Field Communication) is increasing. Therefore, a ceramic substrate manufacturing method using a setter according to the prior art is applied to the production of magnetic sheets for NFC.

However, since the magnetic sheet for NFC contains a highly reactive component such as zinc oxide (ZnO), the method of manufacturing a ceramic substrate using a setter according to the prior art is applied to cause a fluctuation of component elements by reacting with a setter during baking, There is a problem that a difference in firing shrinkage ratio can be generated.

In addition, this makes it difficult to obtain a smooth ceramic sheet, and problems such as warping and characteristic deterioration may occur.

In addition, the production of the setter basically involves a lot of post-processing after cutting and grinding after press molding in order to maintain a high density, so that the cost can be increased.

Korean Patent Registration No. 10-1070148 (registered on September 27, 2011)

It is an object of the present invention to provide a method for manufacturing a high strength ceramic substrate for electronic ceramic firing which can produce a high-strength ceramic substrate for electronic ceramic firing such as a setter having a low reactivity with an object to be fired at low cost at low cost, And to provide a high strength ceramic substrate for ceramic firing.

In order to achieve the above object, a method of manufacturing a high strength ceramic substrate for electronic ceramic firing according to the present invention is characterized by comprising the steps of: preparing a raw material mixture of alumina (Al ₂ O ₃ ), yttria-stabilized zirconia (YSZ) Mixing step (a); (B) defoaming and aging the mixed mixture through the step (a); (C) molding the mixture obtained through the step (b) by a thick film molding process; (D) performing lamination and warm-isostatic pressing (WIP) on the molded article molded in the step (c); (E) cutting the formed body after step (d) and sintering the cut body in an electric furnace at a temperature range of 1400 to 1600 ° C.

Here, in the step (a), the particle sizes of the alumina and yttria-stabilized zirconia powder are 0.3 to 10 μm and 0.1 to 3 μm, respectively, and the binder preferably includes a polyvinyl butyral (PVB) system.

Wherein the weight ratio of alumina to yttria stabilized zirconia is from 2: 8 to 8: 2 and the weight ratio of binder added to the alumina and yttria stabilized zirconia mixture is in the range of: The binder is preferably 1: 0.5.

In step (b), defoaming is performed for 1 hour, and ball milling is preferably performed at 20 rpm for 24 hours to evenly disperse the defoamed slurry.

In the step (c), it is preferable that the thick film forming is performed using a tape casting equipment.

The step (d) is preferably a step of laminating the formed bodies by using a laminator, setting the upper and lower temperatures at 60 DEG C, laminating them, and performing a compression process for 30 minutes at a pressure of 30 MPa using WIP equipment .

The step (e) is preferably a step of cutting the laminated sheet using a cutter and sintering the cut formed body at a temperature of 1400 ° C, 1500 ° C, and 1600 ° C by 5 ° C per minute for 10 minutes Do.

In order to achieve the above object, a high strength ceramic substrate for electronic ceramic firing according to the present invention is manufactured by the above manufacturing method.

According to the present invention, there is provided a method for producing a high-strength ceramic substrate for electronic ceramic firing, which can produce a high-strength ceramic substrate for electronic ceramic firing such as a setter having a low reactivity with a fired product at low cost at a low cost, A high strength ceramic substrate for firing can be provided.

1 is a schematic process flow diagram of a method for manufacturing a high-strength ceramic substrate for electronic ceramic firing according to the present invention,
2 is a graph showing a volume shrinkage ratio of a specimen according to a sintering temperature,
FIG. 3 is a graph showing a change in the molding density of the specimen according to the sintering temperature,
4 is a graph showing Vickers hardness values of specimens according to sintering temperatures,
FIG. 5 is a SEM photograph of an alumina substrate produced according to sintering temperature and weight ratio of alumina and YSZ.

As shown in FIG. 1, the present invention is characterized in that an additive yttria-stabilized zirconia (YSZ) powder is added to an alumina powder and a sintering process in an atmospheric environment using a thick film So that a high-strength ceramic substrate for electronic ceramic firing such as a setter can be manufactured.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

(a) raw material mixing step

Alumina (Al ₂ O ₃ ) and YSZ powder are mixed in a binder of polyvinyl butyral (PVB) system and mixed.

At this time, the alumina and YSZ are mixed so that the weight mixing ratio is 2: 8 to 8: 2. For example, if the weight percentage of alumina is 20 wt%, the weight% of YSZ is 80 wt%, and if the weight percentage of alumina is 30 wt%, the weight% of YSZ is 70 wt% Is 80% by weight, the weight% of YSZ is 20% by weight.

In one embodiment of the present invention, the sizes of the raw material powders of alumina and yttria-stabilized zirconia are preferably 0.3 to 10 mu m and 0.1 to 3 mu m, respectively.

Thereafter, the mixed solution of the alumina, YSZ and binder is subjected to a ball milling process so as to be sufficiently performed at 180 rpm for 24 hours.

For effective ball milling, zirconia balls having diameters of 3 mm, 5 mm, and 10 mm are added to the mixed solution of alumina, YSZ, and binder so that the total weight of the zirconia balls is 300 g.

In one embodiment of the present invention, it is preferable that the mixed liquid of alumina, YSZ and the binder is subjected to a ball milling process under the same conditions in the same ball milling machine.

(b) Degassing and aging step

The mixture is subjected to a ball milling process for 24 hours to remove the zirconia balls from the mixture, followed by sufficiently defoaming the bubbles.

The aging process is then continued for 24 hours to evenly disperse the bubbled mixture.

(c) a step of molding by a thick film molding process

Subsequently, the mixture was subjected to thick film formation using a tape casting equipment. A high density polyethylene film having a thickness of 70 탆 was used. The molding speed was 1.0 m / min. The comma head comma head height is set to 300 탆.

At this time, the drying temperature is progressed at about 35 to 75 ° C for each section, thereby enabling effective drying.

(d) Pressurization (WIP) step such as lamination and warming

The formed molded object is laminated by setting the upper and lower temperature at 60 占 폚 with a pressing time of 60 seconds per sheet using a laminator such as a laminator.

Warm Isostatic Pressing (WIP) uses WIP equipment to perform the pressing process at a pressure of 30 MPa for 30 minutes at a water temperature of 70 ° C.

(e) cutting and sintering in air atmosphere

After completion of the squeezing, the laminated molded body is cut to a proper size using a cutter, and a sintering process is performed using an electric furnace in an atmospheric environment.

Sintering may be performed at temperatures of 1400 ° C, 1500 ° C, and 1600 ° C, respectively, and the temperature rise time is preferably 5 ° C per minute. In one embodiment of the present invention, the sintering is preferably performed at a temperature of 1400 ° C, 1500 ° C, or 1600 ° C at a rate of 5 ° C per minute, and maintained at a temperature elevated for 10 minutes.

On the other hand, by forming a smooth high-strength and high-density coating layer on the alumina substrate thus produced, reactivity with the object to be cleaned is lowered, and a setter having high strength, that is, a ceramic substrate for firing an electronic ceramic can be produced.

As a result, a large-sized high-strength ceramic substrate can be mass-produced at a lower cost than the compression compression molding method. In addition, the alumina-YSZ composite has a very high mechanical strength as compared with conventional alumina, and has a high thermal conductivity and a very low sintering temperature of 1400 to 1600 ° C.

[Example]

Alumina and yttria stabilized zirconia (YSZ) powder are mixed with a binder, and the weight percentages of alumina and YSZ powder are mixed so that a weight mixing ratio of alumina: YSZ = 20 to 80 wt%: 80 to 20 wt%. In this embodiment, the most optimum condition was observed when alumina and YSZ powder were mixed at a weight mixing ratio of alumina: YSZ = 60 wt%: 40 wt%.

This is because the weight ratio of alumina to YSZ powder is the most appropriate in the weight percent of the mixture and the mechanical strength is also high.

Table 1 below shows blending amounts of alumina, YSZ powder and binder. The binder is added to the mixture 1 of alumina and YSZ powder in the same weight ratio of all 0.5.

Psalter Al ₂ O ₃ (wt%) YSZ (wt%) Binder (wt%) Al ₂ O ₃ (8) YSZ (2) 80 20 50 Al ₂ O ₃ (6) YSZ (4) 60 40 50 Al ₂ O ₃ (4) YSZ (6) 40 60 50 Al ₂ O ₃ (2) YSZ (8) 20 80 50

For reference, Al ₂ O ₃ (8) YSZ (2) in Table 1 indicates that the weight mixing ratio of alumina: YSZ powder is 8: 2.

Thereafter, a mixed solution of the alumina, the YSZ powder and the binder is sufficiently subjected to a ball milling process at 180 rpm for 24 hours.

At this time, zirconia balls having diameters of 3 mm, 5 mm, and 10 mm are added to the mixed solution of alumina, YSZ and binder so that the total weight of the zirconia balls is 300 g, so that a dry ball milling process is performed. Zirconia balls are made of high density and are very strong and hard. Their surface is smooth and the risk of breakage is low. In order to effectively mix the alumina and YSZ powder particles used, efficient mixing process was performed by mixing ball sizes during ball milling .

Thereafter, the mixture is subjected to a ball milling process for 24 hours to remove the zirconia balls, followed by thoroughly defoaming for 1 hour to remove bubbles and aging treatment for 24 hours to allow secondary mixing. At this time, ball milling is performed at 20 rpm for 24 hours so that the defoamed mixture slurry is uniformly dispersed.

After completion of the aging treatment, the mixture was molded into a sheet through a thick film forming process using a tape casting machine, and the laminate was subjected to a lamination process by setting the upper and lower temperatures at 60 DEG C for 60 seconds per sheet, lamination. Thereafter, a warm-pressing (WIP) process is performed.

The compacted body having undergone the warm pressing process is cut to an appropriate size and sintered in an atmospheric environment at 1400 to 1600 ° C using an electric furnace.

The sintered specimens were surface polished through a hot mounting press process and then compared with hardness measurements using a Vickers hardness tester. After that, SEM (Scanning Electron Microscope) And how the structure changes.

FIG. 2 is a graph showing the sintering temperature and the volume shrinkage ratio of the specimen according to the weight mixing ratio of alumina and YSZ. As the sintering temperature and YSZ content increased, the volume shrinkage (%) tended to increase.

Fig. 3 is a graph showing changes in the molding density depending on the sintering temperature and the weight mixing ratio of alumina and YSZ. As the sintering temperature and the amount of YSZ added increased, the molding density tended to increase.

FIG. 4 is a graph showing Vickers hardness values of specimens according to sintering temperatures and weight mixing ratios of alumina and YSZ. The higher the sintering temperature and the YSZ content in proportion to the volume shrinkage and the molding density, the higher the Vickers hardness value.

Table 2 below shows Vickers hardness values according to the sintering temperature.

Psalter
Vickers Hardness Number (Hv) GPa 1400 ° C 1500 ℃ 1600 ° C 1400 ° C 1500 ℃ 1600 ° C Al ₂ O ₃ (8) YSZ (2) 981 1240 1421 9.6 12.2 14.0 Al ₂ O ₃ (6) YSZ (4) 1116 1558 1946 11.0 15.3 19.1 Al ₂ O ₃ (4) YSZ (6) 1308 1769 2346 12.8 17.4 23.0 Al ₂ O ₃ (2) YSZ (8) 1511 1988 2686 14.8 19.5 26.3

As shown in Table 2, as the sintering temperature increases, the hardness value increases and the crack length decreases.

FIG. 5 shows the microstructure at a sintering temperature of 1400 to 1600 ° C. It can be seen that as the sintering temperature and the amount of YSZ added increase, the microstructure tends to become more dense.

Accordingly, the Vickers hardness of the alumina substrate as the high strength ceramic substrate for electronic ceramic firing according to the present invention can be greatly increased.

A maximum Vickers hardness value of 2600 Hv was observed even at a sintering temperature of 1600 ° C. However, in this case, the ratio of YSZ is 80 wt% and the ratio of alumina is 20 wt%. Therefore, considering the material cost of alumina and YSZ, Al ₂ O ₃ which alumina is the Vickers hardness value of at sintering temperature of 1600 ℃ because it is much cheaper 2000 Hv and out of observation than YSZ (6) YSZ (4) and Al ₂ O ₃ (4) Al ₂ O ₃ (6) YSZ (4) conditions in which the alumina ratio is 60 wt% and the YSZ ratio is 40 wt% in YSZ (6) can be selected as a condition for obtaining optimum mechanical strength have.

In other words, because it uses the thick film process which is easy to mass-produce, the process cost is saved, and it is easy to match the size and thickness of the desired substrate. The effect of additive YSZ enables sintering even at a low temperature of 1400 ° C. to 1600 ° C., It is possible to obtain a higher mechanical strength than the alumina substrate at a sintering temperature of 1700 DEG C or higher.

Thus, according to the present invention, there is provided a method for manufacturing a high-strength ceramic substrate for electronic ceramic firing, which can produce a high-strength ceramic substrate for electronic ceramic firing such as a setter having a low reactivity with a fired product at low cost at low cost, A high strength ceramic substrate for electronic ceramic firing can be provided.

While the invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (8)

Alumina (Al ₂ O ₃ ) having a particle diameter of 0.3 to 10 μm and yttria-stabilized zirconia (YSZ) having a thickness of 0.1 to 3 μm were mixed at a weight ratio of 6: 4, and polyvinyl butyral (PVB) (A) adding a binder to the alumina and yttria-stabilized zirconia mixture so that the binder has a weight ratio of 1: 0.5;
(B) defoaming and aging the mixed mixture through the step (a);
(C) forming the mixture through the step (b) into a thick film molding process using a tape casting equipment;
(WIP) process in which a molded article molded in the step (c) is laminated by using a laminator and laminated by setting the upper and lower temperatures at 60 DEG C and subjected to a compression process at a pressure of 30 MPa for 30 minutes, Warm Isostatic Pressing);
(E) cutting the formed body after step (d), heating the cut body in an electric furnace at a temperature of 1600 ° C at a rate of 5 ° C per minute for 10 minutes and sintering;
Wherein the first ceramic substrate and the second ceramic substrate are bonded to each other. The method according to claim 1,
In the step (b)
Degassing is performed for 1 hour, and ball milling is performed at 20 rpm for 24 hours so that the defoamed mixture slurry is uniformly dispersed. A high strength ceramic substrate for electronic ceramic firing, which is produced by the manufacturing method according to any one of claims 1 to 2. delete delete delete delete delete

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