KR100302455B1 - Dielectric ceramic composition for high frequency - Google Patents

Dielectric ceramic composition for high frequency Download PDF

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KR100302455B1
KR100302455B1 KR1019980030344A KR19980030344A KR100302455B1 KR 100302455 B1 KR100302455 B1 KR 100302455B1 KR 1019980030344 A KR1019980030344 A KR 1019980030344A KR 19980030344 A KR19980030344 A KR 19980030344A KR 100302455 B1 KR100302455 B1 KR 100302455B1
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high frequency
dielectric
mgnb
ceramic composition
tio
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KR20000009735A (en
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김효태
박재관
김인태
박재환
김윤호
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박호군
한국과학기술연구원
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
    • H01B3/12—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances ceramics
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3232—Titanium oxides or titanates, e.g. rutile or anatase
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3251—Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof
    • C04B2235/3255—Niobates or tantalates, e.g. silver niobate

Abstract

본 발명은 고주파용 세라믹스 조성물에 관한 것으로, 특히 1 mole의 MgNb2O6에 대해 각각 0 ∼ 1 mole의 TiO2를 조합으로 하는 것을 주 조성으로 하고 첨가제로서 MO3(M6+= W, Mo, Cr, Se, Te 및 Po)가 각각 0 ∼ 0.4 wt%로 구성되는 것을 특징으로 하는 유전체 세리믹스 조성물에 관한 것으로, 기존의 고주파 유전체 조성보다 비교적 낮은 소결온도 (1,200℃)이면서 높은 품질계수 (QX f > 40,000 GHz)와 유전상수 ( εr > 25) 및 안정된 온도계수 (τf = -49∼ +38 ppm/℃)의 우수한 고주파 유전특성이 MgNb2O6-TiO2와 같은 비교적 저가의 원료로 구현되는 것을 특징으로 한다.The present invention relates to a ceramic composition for high frequency, in particular 0 to 1 mole of TiO 2 in combination with respect to 1 mole of MgNb 2 O 6 as a main composition and as an additive MO 3 (M 6 + = W, Mo , Cr, Se, Te, and Po), each of which is composed of 0 to 0.4 wt% of dielectric dielectric composition, which has a relatively low sintering temperature (1,200 ° C) and high quality factor ( Excellent high frequency dielectric properties of QX f> 40,000 GHz), dielectric constant (εr> 25) and stable temperature coefficient (τf = -49 to +38 ppm / ° C) are relatively inexpensive materials such as MgNb 2 O 6- TiO 2 . Characterized in that implemented.

Description

고주파용 유전체 세라믹스 조성물{DIELECTRIC CERAMIC COMPOSITION FOR HIGH FREQUENCY}Dielectric ceramic composition for high frequency {DIELECTRIC CERAMIC COMPOSITION FOR HIGH FREQUENCY}

본 발명은 고주파용 유전체 세라믹스 조성물에 관한 것으로, 특히 1 mole의 MgNb2O6에 대해 0∼1 mole의 TiO2를 조합으로 하는 것을 주조성으로 하고 첨가제로서 WO3가 0∼0.4 wt.%로 구성되는 것을 특징으로 하는 유전체 세라믹스 조성물에 관한 것이다.The present invention relates to a dielectric ceramic composition for high frequency, in particular 0 to 1 mole of TiO 2 in combination with 1 mole of MgNb 2 O 6 is castable and WO 3 is 0 to 0.4 wt.% As an additive. It is related with the dielectric ceramic composition characterized by the above-mentioned.

최근 이동 통신 및 위성통신의 급속한 발전과 더불어 고주파 집적회로 또는 유전체 공진기의 재료로서 고주파용 유전체 세리믹스 수요가 크게 증가하고 있다.In recent years, with the rapid development of mobile communication and satellite communication, the demand for high-frequency dielectric ceramics as a material for high-frequency integrated circuits or dielectric resonators has been greatly increased.

고주파용으로 사용되는 유전체 세리믹스의 주요 특성으로는 가능한 한 높은 유전상수(εr〉25) 및 안정 (stable)하고도 조절 가능한 (tunable) 공진 주파수의 온도 계수 (τf)가 요구된다.The main characteristics of dielectric ceramics used for high frequencies require a high dielectric constant (ε r > 25) and a temperature coefficient of stable and tunable resonant frequency (τ f ).

지금까지 알려진 대표적인 고주파용 유전체 조성은 (Zr, Sn)TiO4계, BaO-TiO2계,(Mg, Ca)TiO3계, Ba-페로브스카이트계 {Ba(Zn1/3Ta2/3)O3, Ba(Mg1/3Ta2/3)O3, Ba(Zn1/3Nb2/3)O3등}이다. 그러나, 이들 조성은 대부분 1,300 ∼ 1,500℃의 고온에서 소결 가능하거나, 유전 상수가 낮거나 또는 고가의 원료를 사용하여야 한다.Representative high frequency dielectric compositions so far known are (Zr, Sn) TiO 4 based, BaO-TiO 2 based, (Mg, Ca) TiO 3 based, Ba-perovskite based {Ba (Zn 1/3 Ta 2/3 ) O 3 , Ba (Mg 1/3 Ta 2/3 ) O 3 , Ba (Zn 1/3 Nb 2/3 ) O 3, and the like. However, most of these compositions must be sinterable at high temperatures of 1,300 to 1,500 ° C, or have low dielectric constant or expensive raw materials.

상술한 문제점을 극복하기 위해, 본 발명은 상기 조성보다 비교적 낮은 소결 온도(1,200℃)이면서도 높은 품질계수(Q×f ＞ 40,000 ㎓)와 유전상수 (εr＞ 25) 및 안정된 온도계수 (τf= -49 ∼+38 ppm/℃)의 우수한 고주파 유전특성을 비교적 저가의 원료로부터 구현할 수 있도록 하는 것을 목적으로 한다.In order to overcome the above-mentioned problems, the present invention has a relatively low sintering temperature (1,200 ° C.) and a high quality factor (Q × f> 40,000 kPa), a dielectric constant (ε r > 25) and a stable temperature coefficient (τ f). It is an object of the present invention to realize excellent high frequency dielectric properties (= -49 to +38 ppm / ° C) from relatively inexpensive raw materials.

이에, 본 발명은, MgNb2O6+ xTiO2(여기서 x = 0 ∼ 1.0)으로 이루어지는 고주파 유전체 세라믹스 조성물을 제공한다.Accordingly, the present invention provides a high frequency dielectric ceramic composition composed of MgNb 2 O 6 + xTiO 2 (where x = 0 to 1.0).

또한, 상기 조성물에 MO3(M = W, Mo, Cr, Se, Te, Po 중 선택되는 어느 한 종)가 0 ∼ 0.4 wt%로 첨가된 고주파 유전체 세라믹스 조성물을 제공한다.In addition, there is provided a high frequency dielectric ceramic composition in which MO 3 (any one selected from M = W, Mo, Cr, Se, Te, Po) is added to the composition at 0 to 0.4 wt%.

이하에서는 본 발명에 의한 고주파 유전체 세라믹스 조성물의 대표적인 실시예를 나타낸다. 본 발명의 주조성으로서 MgNb2O6는 1 mole의 MgO (>99%)와 1 mole의 Nb2O5(>99%)를 습식 볼 밀링법으로 혼합하여 건조 후 1100℃에서 4시간 하소하여 합성하였다. 이 하소 분말을 다시 24시간 분쇄한 다음 건조한 분말에 2 wt%의 PVA 바인더를 첨가한 수용액을 분사하여 약 200 μm 크기의 조립 (granule)으로 만들어98 MPa의 압력으로 직경 10 mm, 두께 4.8mm인 디스크 시편을 형성한다. 성형 시편은 300 ∼500℃에서 3 시간 이상 유지시켜 바인더를 제거하고 나서 1150∼1250℃로 대기중에서 4 시간 동안 소성한다. 이때, 승온 속도는 각각 5℃/min으로 하였다. 소결 시편은 SiC 연마지 (#1,500)로 연마하여 시편의 직경 대비 두께의 비가 약 0.45가 되도록 하였다. 고주파 유전 특성은 네트워크 분석기 (network analyzer : HP 8720C)를 써서 TE01δ모드에서 측정하였으며, 유전상수는 하키 콜만 (Hakki - Coleman)법으로 그리고 품질계수는 오픈 캐비티 (open cavity)법으로, 공진 주파수의 온도 계수는 인바 캐비티 (invar cavity)를 써서 +20∼+70℃의 온도 범위에서 측정하였다. 표 1의 실시예 1번은 1200℃에서 4시간 소결한 시편의 고주파 유전특성을 나타낸 것이다. 실시예에서 순수한 MgNb2O6의 유전 상수는 약 22, 품질계수는 74,100 그리고 온도계수는 -15 ppm/℃로 나타났다. 이조성은 품질 계수는 우수하지만 유전 상수가 낮고 온도 계수가 비교적 커서 (일반적으로 < ±10ppm/℃가 요구됨) 이를 좀더 개선할 필요가 있다. 따라서, 본 발명에서는 온도계수를 0 ppm/℃ 부근으로 안정화시키기 위해 온도 계수가 +430 ppm/℃이고 품질계수가 10,000 (4 ㎓,즉 Q×f = 40,000 ㎓)그리고 유전상수가 105인 TiO2를 온도 보상 물질로 선택하였다. 본 발명에서는 MgNb2O61 mole에 대해 0 ∼ 1.0 mole의 TiO2를 첨가하는 조성을 고안하였으며, 그 결과를 실시예인 표 1의 실시예 2번 내지 6번에 나타내었다.Hereinafter, a representative embodiment of the high frequency dielectric ceramic composition according to the present invention is shown. As castability of the present invention, MgNb 2 O 6 is mixed with 1 mole of MgO (> 99%) and 1 mole of Nb 2 O 5 (> 99%) by wet ball milling and then calcined at 1100 ° C. for 4 hours. Synthesized. The calcined powder was pulverized again for 24 hours and then sprayed with an aqueous solution containing 2 wt% PVA binder to dry powder to form granules of about 200 μm in size, 10 mm in diameter and 4.8 mm thick at a pressure of 98 MPa. Form a disk specimen. The molded specimen is kept at 300 to 500 ° C. for at least 3 hours to remove the binder, and then fired at 1150 to 1250 ° C. for 4 hours in the air. At this time, the temperature increase rate was 5 degrees C / min, respectively. The sintered specimens were polished with SiC abrasive paper (# 1,500) so that the ratio of the thickness to the diameter of the specimens was about 0.45. The high frequency dielectric properties were measured in TE 01δ mode using a network analyzer (HP 8720C), and the dielectric constant was determined by the hakki- coleman method and the quality factor was determined by the open cavity method. The temperature coefficient was measured in the temperature range of +20 ~ +70 ℃ using an invar cavity. Example 1 of Table 1 shows the high frequency dielectric properties of the specimen sintered at 1200 ℃ for 4 hours. In the examples, the pure MgNb 2 O 6 had a dielectric constant of about 22, a quality factor of 74,100 and a temperature coefficient of -15 ppm / ° C. This composition has a good quality factor but a low dielectric constant and a relatively large temperature coefficient (typically <± 10 ppm / ° C), which needs to be further improved. Therefore, in the present invention, TiO 2 having a temperature coefficient of +430 ppm / ° C, a quality factor of 10,000 (4 mV, Q × f = 40,000 mV) and a dielectric constant of 105 in order to stabilize the temperature coefficient near 0 ppm / ° C. Was chosen as the temperature compensating material. In the present invention, a composition in which 0 to 1.0 mole of TiO 2 is added to MgNb 2 O 6 1 mole was devised, and the results are shown in Examples 2 to 6 of Table 1 as examples.

MgNb2O6+ xTiO2의 마이크로파 유전특성Microwave Dielectric Properties of MgNb 2 O 6 + xTiO 2 No.No. x(mol)x (mol) 유전상수(εr)Dielectric constant (ε r ) 품질계수(Q×f ㎓)Quality factor (Q × f ㎓) 공진 주파수의온도 계수(τf: ppm/℃)Temperature coefficient of resonant frequency (τ f : ppm / ℃) 1One 00 22.122.1 74,10074,100 -15-15 22 0.20.2 23.023.0 83,90083,900 -49-49 33 0.40.4 26.626.6 78,00078,000 -37-37 44 0.60.6 32.432.4 41,80041,800 00 55 0.80.8 39.939.9 23,90023,900 +38+38 66 1.01.0 47.547.5 11,60011,600 +82+82 * 1200℃, 4시간 공기중에서 소결* Sintered in air at 1200 ℃ for 4 hours

그 결과 본 발명의 목적대로 유전 상수가 약 22에서 32로, 온도계수는 0 ppm/℃ 부근에서 TiO2의 양에 따라 온도 보상 특성을 보였다. 한편, 품질 계수는 순수 MgNb2O5보다 감소한 값을 보였는데, 이것은 첨가된 TiO2가 MgNb2O6와 복합체 구조를 이루고, 또한 일부의 Ti4이온이 Nb5+를 치환함에 따른 반도체화 (소결 시편이 순수 MgNb2O6보다 약간 어두운 색을 띠었음)에 기인하는 것으로 분석되었다. 따라서, 후자의 원인에 따른 품질계수의 저하를 개선하기 위해 전하 보상의 기구 (charge compensation mechanism)를 적용하여 양이온이 M+6(M = W, Mo, Cr, Se, Te, Po)인 산화물 (MO3)을 소량 (0∼0.4 wt.%) 첨가하였다. 그 결과, 소결 시편의 색이 밝은 색으로 변함으로써 본 발명의 의도가 작용함을 확인할 수 있었다. 더 구체적으로는 표 2와 같이 첨가물 중에서 대표적인 W6+를 첨가 (WO3로서)한 경우 시료의 고주파 유전 특성으로서, 실시예인 표 2의 7 ∼ 12번과 같이 품질 계수가 약 20% 향상되었다. 한편, 이들 첨가물에 의한 유전상수의 감소는 매우 작았으며, 온도계수는 양으로 미소하게 이동하였는데 이에 따른 추가적인 온도보상은 실시예인 표 1의 결과를적용하여 TiO2의 앙을 미소 변화 (약간 감소)시킴으로써 0 ppm/℃ 부근으로 조절 가능하다.As a result, the dielectric constant was about 22 to 32 for the purpose of the present invention, and the temperature coefficient showed temperature compensation characteristics according to the amount of TiO 2 in the vicinity of 0 ppm / ° C. On the other hand, the quality factor was lower than that of pure MgNb 2 O 5 , which means that the added TiO 2 forms a complex structure with MgNb 2 O 6, and some Ti 4 ions are replaced by Nb 5+ . Sintered specimens were slightly darker than pure MgNb 2 O 6 ). Therefore, in order to improve the degradation of the quality factor due to the latter cause, an oxide having a cation of M +6 (M = W, Mo, Cr, Se, Te, Po) by applying a charge compensation mechanism ( MO 3 ) was added in small amounts (0 to 0.4 wt.%). As a result, it was confirmed that the intention of the present invention works by changing the color of the sintered specimen to a bright color. More specifically, when representative W 6+ was added (as WO 3 ) in the additives as shown in Table 2, the quality factor of the sample was improved by about 20% as shown in Tables 7 to 12 in Examples. On the other hand, decrease in the dielectric constant due to these additives were very small, the temperature coefficient is were smiling moved in both this additional temperature compensation is carried out applying a result of the towing Table 1 Ang a fine change (a slight decrease) of TiO 2 according to It is possible to adjust to around 0 ppm / ° C.

여기서 상기 첨가제로는 W, Mo, Cr, Se, Te 및 Po로 구성되는 군으로부터 선택되는 어느 하나이어도 본 발명의 효과는 충분히 달성될 수 있다.In this case, the additive may be sufficiently attained even if the additive is one selected from the group consisting of W, Mo, Cr, Se, Te, and Po.

(MgNb2O6+ 0.6TiO2) +yM(M = W)O3의 마이크로파 유전특성Microwave Dielectric Properties of (MgNb 2 O 6 + 0.6TiO 2 ) + yM (M = W) O 3 No.No. y(wt%)y (wt%) 유전상수(εr)Dielectric constant (ε r ) 품질계수(Q×f ㎓)Quality factor (Q × f ㎓) 공진 주파수의온도 계수(τf: ppm/℃)Temperature coefficient of resonant frequency (τ f : ppm / ℃) 77 0.100.10 31.631.6 43,00043,000 +6+6 88 0.150.15 31.931.9 45,00045,000 +5+5 99 0.200.20 31.531.5 50,10050,100 +4+4 1010 0.250.25 31.531.5 47,80047,800 +4+4 1111 0.300.30 31.531.5 46,80046,800 +8+8 1212 0.400.40 32.232.2 44,60044,600 +17+17 * 1200℃, 4시간 공기 중에서 소결.* Sintered at 1200 ° C for 4 hours in air.

본 발명에 따르면, 기존의 고주파 유전체 조성보다 비교적 낮은 소결온도 (1,200℃)이면서 높은 품질계수 (QX f > 40,000 GHz)와 유전상수 ( εr > 25) 및 안정된 온도계수 (τf = -49∼ +38 ppm/℃)의 우수한 고주파 유전특성이 비교적 저가의 원료로 구현될 수 있다.According to the present invention, it has a relatively low sintering temperature (1,200 ° C.), a high quality factor (QX f> 40,000 GHz), a dielectric constant (εr> 25), and a stable temperature coefficient (τf = -49 to +38). Excellent high frequency dielectric properties (ppm / ° C.) can be implemented as a relatively low cost raw material.

Claims (2)

다음 식으로 이루어지는 것을 특징으로 하는 고주파 유전체 세라믹스 조성물:A high frequency dielectric ceramic composition comprising the following formula: MgNb2O6+ xTiO2, 여기서 x = 0 ∼ 1.0.MgNb 2 O 6 + xTiO 2 , where x = 0 to 1.0. 제 1 항에 있어서, 상기 조성물에 MO3(M = W, Mo, Cr, Se, Te, Po 중 선택되는 어느 한 종)가 0 ∼ 0.4 wt%로 첨가된 것을 특징으로 하는 고주파 유전체 세라믹스 조성물.The high frequency dielectric ceramic composition according to claim 1, wherein MO 3 (any one selected from M = W, Mo, Cr, Se, Te, Po) is added to the composition at 0 to 0.4 wt%.
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KR100365294B1 (en) 2000-04-21 2002-12-18 한국과학기술연구원 Low temperature sinterable and low loss dielectric ceramic compositions and method of thereof
KR100365295B1 (en) 2000-05-03 2002-12-18 한국과학기술연구원 Low temperature sinterable and low loss dielectric ceramic compositions and method of thereof
KR100372689B1 (en) * 2000-06-28 2003-02-17 삼성전기주식회사 A method for manufacturing microwave dielectrics

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JPH0959062A (en) * 1995-06-15 1997-03-04 Matsushita Electric Ind Co Ltd Conductor ceramic composition, its production and laminate-type high-frequency device
KR19980029499A (en) * 1996-10-26 1998-07-25 김영귀 Intake port structure of cylinder head

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* Cited by examiner, † Cited by third party
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JPH0959062A (en) * 1995-06-15 1997-03-04 Matsushita Electric Ind Co Ltd Conductor ceramic composition, its production and laminate-type high-frequency device
KR19980029499A (en) * 1996-10-26 1998-07-25 김영귀 Intake port structure of cylinder head

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