KR19980058557A - Perovskite-based Medium Temperature Thermistor Composition - Google Patents
Perovskite-based Medium Temperature Thermistor Composition Download PDFInfo
- Publication number
- KR19980058557A KR19980058557A KR1019960077882A KR19960077882A KR19980058557A KR 19980058557 A KR19980058557 A KR 19980058557A KR 1019960077882 A KR1019960077882 A KR 1019960077882A KR 19960077882 A KR19960077882 A KR 19960077882A KR 19980058557 A KR19980058557 A KR 19980058557A
- Authority
- KR
- South Korea
- Prior art keywords
- medium temperature
- perovskite
- temperature thermistor
- composition
- range
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
- H01C7/02—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient
- H01C7/022—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient mainly consisting of non-metallic substances
- H01C7/023—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient mainly consisting of non-metallic substances containing oxides or oxidic compounds, e.g. ferrites
- H01C7/025—Perovskites, e.g. titanates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
- H01C7/04—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having negative temperature coefficient
- H01C7/042—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having negative temperature coefficient mainly consisting of inorganic non-metallic substances
- H01C7/043—Oxides or oxidic compounds
- H01C7/045—Perovskites, e.g. titanates
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/46—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on titanium oxides or titanates
- C04B35/462—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on titanium oxides or titanates based on titanates
- C04B35/465—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on titanium oxides or titanates based on titanates based on alkaline earth metal titanates
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Ceramic Engineering (AREA)
- Thermistors And Varistors (AREA)
Abstract
본 발명은 페로브스카이트계 중온용 써미스터 조성물에 관한 것으로, 종래의 중온용 써미스터는 사용온도영역이 좁고 결정구조가 불안정하여 신뢰성에 문제가 있으며, 급격히 증가되는 수요에 대응하기 위해서는 400℃ 이하의 온도범위에서 안정한 결정구조와 적당한 저항값 및 b정수를 갖는 중온용 써미스터의 개발이 요구되어 왔다.The present invention relates to a perovskite-based medium temperature thermistor composition, the conventional medium temperature thermistor has a narrow operating temperature range and unstable crystal structure has a problem in reliability, in order to cope with the rapidly increasing demand temperature below 400 ℃ There has been a demand for the development of a medium temperature thermistor having a stable crystal structure in the range, an appropriate resistance value, and a b constant.
본 발명은 (100-a-b-c)망간산칼슘(CaMnO3) + (a)티산산칼륨(CaTiO3) + (b)티탄산스트론튬(SrTiO3) + (c)티탄산바륨(BaTiO3)계를 기본조성으로 하여 중량%로 각각 75a≤95, 75≤b≤95, 75≤c≤95의 범위와 75≤a+b+c≤95의 범위를 조성으로 하는 페로브스카이트계 중온용 써미스터 조성물을 제공함으로써, 전자렌지, 가스렌지, 가스오븐, 급탕기, 조리기 등 가정용 전기 및 가스기구나 반응조, 건조로 등에 적용하여 신뢰성을 향상시키는 효과를 가져올 수 있다.The present invention is based on (100-abc) calcium manganate (CaMnO 3 ) + (a) potassium titanate (CaTiO 3 ) + (b) strontium titanate (SrTiO 3 ) + (c) barium titanate (BaTiO 3 ) By providing a perovskite-based medium temperature thermistor composition having a composition in the range of 75a≤95, 75≤b≤95, 75≤c≤95 and 75≤a + b + c≤95 by weight, respectively. Can be applied to household electrical and gas appliances such as microwave ovens, gas stoves, gas ovens, hot water heaters, cookers, reactors, drying furnaces, etc., to bring about an effect of improving reliability.
Description
본 발명은 페로브스카이트계 중온용 써미스터 조성물에 관한 것으로서, 더욱 상세하게는 약 400℃ 이하의 중온에서 안정한 결정구조와 적당한 저항값 및 B정수를 갖는 페로브스카이트계 중온용 써미스터 조성물에 관한 것이다.The present invention relates to a perovskite-based medium temperature thermistor composition, and more particularly, to a perovskite-based medium temperature thermistor composition having a stable crystal structure at a moderate temperature of about 400 ° C. or lower, an appropriate resistance value, and a B constant.
금속 산화물계 써미스터 소자는 전이금속화합물을 일정량씩 조합하여 만든 온도에 따라 전기저항이 지수함수적으로 감소하는 반도체로서 온도감지소자, 온도보상 및 조절소자, 전압조절용소자 그리고 각종 정밀측정 및 분석기기의 핵심소자로 이용되고 있다.Metal oxide thermistor element is a semiconductor whose electrical resistance decreases exponentially with the temperature made by combining a certain amount of transition metal compound. It is used for temperature sensing device, temperature compensation and control device, voltage control device and various precision measurement and analyzer. It is used as a core element.
일반적으로 써미스터 소자는 사용온도에 따라 100℃ 이하의 상온용, 400℃ 이하의 중온용 그리고 1000℃ 이하의 고온용 써미스터로 구분되며, 상온용 써미스터의 경우 스핀넬계인 망간-니켈-코발트-구리계 금속화합물이 조성에 따라 넓은 범위의 저항값과 온도에 따른 큰 저항 변화(B 정수)를 가짐으로써 널리 이용되고 있다.In general, thermistor elements are classified into room temperature of less than 100 ℃, medium temperature of less than 400 ℃ and high temperature of less than 1000 ℃ according to the operating temperature. Metal compounds are widely used because they have a wide range of resistance values depending on the composition and a large resistance change (B constant) with temperature.
고온용 써미스터의 경우 자동차 및 각종 엔진, 보일러 등 산업용 설비의 배기온도 검출 및 제어를 위하여 사용되고 있으며, 스핀넬계(Al2O3- CoO계 및 MgO - Al2O3- Cr2O3계) ZrO2계(ZrO2- Y2O3계) 및 페로브스카이트계(BaO-TiO2계) 등이 이용되고 있다.The high temperature thermistor is used to detect and control the exhaust temperature of industrial facilities such as automobiles, engines, boilers, etc., and spinel system (Al 2 O 3 -CoO and MgO-Al 2 O 3 -Cr 2 O 3 ) 2 type (ZrO 2 -Y 2 O 3 type ), perovskite type (BaO-TiO 2 type ), and the like are used.
한편, 전자렌지, 가스렌지, 가스오븐, 급탕기, 조리기 등 가정용 전기 및 가스기구나 반응조, 건조로 등에 사용되는 중온용 써미스터는 산업기기의 중가로 그 수요가 급격히 늘어나고 있는 추세에 있으며, 높은 저항을 갖는 조성의 상온용 재료가 일부 이용되고 있다.On the other hand, the medium temperature thermistors used in household appliances such as microwave ovens, gas stoves, gas ovens, hot water heaters, cookers, and gas appliances, reactors, drying furnaces, etc., are in the midst of increasing demand for industrial equipment. The material for normal temperature of the composition which has is used partially.
그러나 종래의 중온용 써미스터는 사용온도영역이 좁고 결정구조가 불안정하여 신뢰성에 문제가 있으며, 급격히 증가되는 수요에 대응하기 위해서는 400℃ 이하의 온도범위에서 안정한 결정구조와 적당한 저항값 및 b 정수를 갖는 중온용 써미스터의 개발이 요구되어 왔다.However, the conventional medium temperature thermistor has a problem of reliability due to its narrow operating temperature range and unstable crystal structure, and has a stable crystal structure, an appropriate resistance value, and a b constant in the temperature range of 400 ° C. or lower in order to meet the rapidly increasing demand. Development of medium temperature thermistors has been required.
따라서, 본 발명은 이와같은 종래의 문제점 해결 및 요구에 부응하기 위한 것으로, 값이 저렴한 산화망간(Mn3O4), 산화티탄(TiO2), 탄산칼슘(CaCO3), 탄산스트론튬(SrCO3), 탄산바륨(BaCO3)을 사용하여 사용온도 영역이 넓고 신뢰성이 높은 양질의 중온용 써미스터를 저렴하게 양산할 수 있는 페로브스카이트계 중온용 써미스터 조성물을 제공하는데 그 목적이 있다.Accordingly, the present invention is to meet such a conventional problem solving and needs, inexpensive manganese oxide (Mn 3 O 4 ), titanium oxide (TiO 2 ), calcium carbonate (CaCO 3 ), strontium carbonate (SrCO 3 It is an object of the present invention to provide a perovskite-based medium temperature thermistor composition capable of inexpensively mass-producing a high-quality medium temperature thermistor having a wide range of use temperature and high reliability using barium carbonate (BaCO 3 ).
이와같은 목적을 실현하기 위한 본 발명은 (100-a-b-c)망간산칼슘(CaMnO3) + (a)티산산칼륨(CaTiO3) + (b)티탄산스트론튬(SrTiO3) + (c)티탄산바륨(BaTiO3)계를 기본조성으로 하여 중량%로 각각 75a≤95, 75≤b≤95, 75≤c≤95의 범위와 75≤a+b+c≤95의 범위를 조성으로 하는 페로브스카이트계 중온용 써미스터 조성물을 제공한다.The present invention for achieving the above object is (100-abc) calcium manganate (CaMnO 3 ) + (a) potassium titanate (CaTiO 3 ) + (b) strontium titanate (SrTiO 3 ) + (c) barium titanate ( Perovskite based on the composition of BaTiO 3 ) based on the composition of the range of 75a≤95, 75≤b≤95, 75≤c≤95 and 75≤a + b + c≤95 Provides a medium temperature thermistor composition.
도 1은 본 발명에 따른 페로브스카이트계 중온용 써미스터의 조성에 따른 300℃에서 비저항의 변화를 나타낸 그래프.1 is a graph showing the change in specific resistance at 300 ℃ according to the composition of the perovskite-based medium temperature thermistor according to the present invention.
도 2는 본 발명에 따른 페로브스카이트계 중온용 써미스터의 조성에 따른 B정수의 변화를 나타낸 그래프.2 is a graph showing the change of B constant according to the composition of the perovskite-based medium temperature thermistor according to the present invention.
도 3은 본 발명에 따른 페로브스카이트계 중온용 써미스터의 저항-온도 특성 그래프.Figure 3 is a resistance-temperature characteristic graph of the perovskite-based medium temperature thermistor according to the present invention.
이하 본 발명의 구성 및 작용효과를 첨부도면과 함께 상세히 설명하면 다음과 같다.Hereinafter, the configuration and operation of the present invention will be described in detail with the accompanying drawings.
써미스터는 온도에 의해 전기저항이 크게 변하는 저항소자를 말하며, 망간, 코발트, 니켈, 철 등의 천이 금속 산화물에 적당한 금속 산화물을 산소 분위기 중에서 혼합 소결하고 이것에 저항성 전극을 부착한 것으로, T[°K]에서의 전기저항치 R과 온도계수 α는 근사적으로 하기의 식으로 주어진다.Thermistor refers to a resistance element whose electrical resistance varies greatly with temperature. A thermistor is a mixture of sintered metal oxides suitable for transition metal oxides such as manganese, cobalt, nickel, and iron in an oxygen atmosphere, and a resistive electrode is attached thereto. The electrical resistance value R and the temperature coefficient α in K] are approximately given by the following equation.
여기서 R0[Ω] 는 T0[°K]에서의 저항치로 B[°K]는 재료에 의한 정수이다. B는 써미스터의 특성을 나타내는 중요한 양으로 B가 클수록 상기식에서 알 수 있는 바와 같이 동일온도 변화에 대한 저항치 변화가 큰 것으로 바람직한 일이다. 그러나 B가 크면 일반적으로 R도 커지므로 B가 큰 재료를 사용하는데는 한계가 있다.Where R 0 [Ω] is the resistance value at T 0 [° K] and B [° K] is an integer by material. B is an important amount indicating the characteristics of the thermistor. As B becomes larger, it is preferable that the resistance change with respect to the same temperature change is larger as shown in the above formula. However, if B is large, R is generally large, so there is a limit to using a material with large B.
본 발명의 페로브스카이트계 중온용 써미스터는 통상적으로 널리 사용되는 산화물 혼합방법으로 용이하게 제조가 가능하다.The perovskite-based medium temperature thermistor of the present invention can be easily manufactured by an oxide mixing method which is commonly used.
산화망간(Mn3O4), 산화티탄(TiO2), 탄산칼슘(CaCO3), 탄산스트론튬(SrCO3), 탄산바륨(BaCO3)을 각각 망간산칼슘(CaMnO3), 티탄산칼륨(CaTiO3), 티탄산스트론튬(SrTiO3), 티탄산바륨(BaTiO3)의 조성이 되도록 정확히 칭량하여 지르코니아 볼밀에서 증류와 함께 잘 혼합하고 분쇄한다.Manganese oxide (Mn 3 O 4 ), titanium oxide (TiO 2 ), calcium carbonate (CaCO 3 ), strontium carbonate (SrCO 3 ) and barium carbonate (BaCO 3 ), respectively, calcium manganese (CaMnO 3 ) and potassium titanate (CaTiO) 3 ), accurately weighed to the composition of strontium titanate (SrTiO 3 ), barium titanate (BaTiO 3 ), mixed well with distillation in a zirconia ball mill and ground.
이때 사용되는 원료는 하소(Calcination)공정을 통하여 산화물로의 전환이 용이한 화합물 즉, 수산화물 및 황산염 등이 포함된 원료 화합물도 가능하다.In this case, the raw material used may be a raw material compound containing a compound which is easily converted to an oxide through a calcination process, that is, a hydroxide and a sulfate.
즉, 혼합된 원료를 1000~1100℃에서 2 시간동안 하소하여 합성한 후, 합성된 원료들을 하기의 표 1의 조성이 되도록 각 중량 %에 따라 정확히 칭양하여 지르코니아 볼밀에서 증류수와 함께 재혼합하여 분쇄한다.That is, the mixed raw materials are calcined at 1000 to 1100 ° C. for 2 hours, and then synthesized, followed by precisely weighing the synthesized raw materials according to the weight percentages to obtain the composition shown in Table 1 below, followed by remixing and grinding with distilled water in a zirconia ball mill. .
혼합된 시료는 PVA 수용액 등의 일반적인 결합제를 1 중량%정도 첨가하여 1 ton/㎠의 압력으로 가압성형하여 알루미나 기판 위에 올려놓고 1300~1350℃의 온도범위에서 2 시간동안 소결한다.The mixed sample was pressed by 1 ton / cm 2 by adding a general binder such as PVA aqueous solution to about 1% by weight and placed on the alumina substrate and sintered for 2 hours in the temperature range of 1300 ~ 1350 ℃.
소결시에는 결합제 등 유기물의 휘발을 위하여 600℃에서 1 시간 동안 유지하며 승온 및 냉각속도는 300℃/hr을 유지한다.During sintering, the mixture is maintained at 600 ° C. for 1 hour for volatilization of organic matter such as a binder, and the temperature rising and cooling rates are maintained at 300 ° C./hr.
소결체는 양면에 백금 페이스트를 스크린 인쇄하여 전극을 형성하고 백금선으로 단자선을 부착하여 1250℃에서 30분간 열처리한 후 600℃에서 10 시간동안 재열처리 한다.The sintered body is screen-printed with platinum paste on both sides to form an electrode, and the terminal wire is attached to the platinum wire and heat-treated at 1250 ° C. for 30 minutes and then reheated at 600 ° C. for 10 hours.
시편의 전기적 특성은 소형 전기로 안에 넣고 100℃에서 500℃ 온도구간에서 2 단자법으로 저항을 측정하며 이때 온도는 3℃/분의 속도로 변화시킨다.The electrical properties of the specimens are placed in a small electric furnace and the resistance is measured by the two-terminal method over a temperature range of 100 ℃ to 500 ℃. At this time, the temperature changes at a rate of 3 ℃ / min.
한편, B 정수는 다음식에 의해 계산된다.On the other hand, the B constant is calculated by the following equation.
표 1은 상기방법으로 제조한 페로브스카이트계 중온용 써미스터의 조성비에 따른 전기적 특성의 결과를 나타낸 도표이며, 이 표에서 조성비는 중량 %이고 비저항은 300℃에서 측정한 값으로 ohm·cm이며 B 정수는 °K로 나타낸 것이다.Table 1 is a table showing the results of the electrical properties according to the composition ratio of the perovskite-based medium temperature thermistor manufactured by the above method, in which the composition ratio is weight% and the specific resistance is measured at 300 ° C. The integer is expressed in ° K.
[표 1]TABLE 1
표 1에 나타난 바와 같이, 반도체 특성을 갖는 망간산칼슘, 티탄산스트론튬, 티탄산바륨을 중량비로 각각 75중량%에서 95중량%까지 증가시킴에 따라 비저항과 B정수는 증가함을 알 수 있으며, 도 1 에서 티탄산스트론튬을 첨가하는 경우 비저항이 낮은 반면 티탄산바륨을 첨가하는 경우 비저항값과 변화율이 큼을 볼 수 있다.As shown in Table 1, it can be seen that the specific resistance and B constant increase as the calcium manganate, strontium titanate, and barium titanate having semiconductor properties are increased from 75% to 95% by weight, respectively. When strontium titanate is added at, the resistivity is low, whereas when barium titanate is added, the resistivity and change rate are large.
이러한 전기적 특성의 변화는 망간산 칼슘에 티탄산칼슘, 티탄산스트론튬, 티탄산바륨을 중량비로 75%에서 95%범위에서 두가지 화합물 이상을 동시에 첨가할 경우에도 동일한 경향을 나타냄을 알 수 있다.This change in electrical properties can be seen that the same tendency in the case of adding more than two compounds at the same time in the range of 75% to 95% calcium titanate, strontium titanate, barium titanate by weight ratio.
한편, 도 3은 본 발명에 따른 페로브스카이트계 중온용 써미스터의 저항-온도특성을 나타낸 그래프로서, 표 1의 조성물 중에서 선택한 것이며, 공히 400℃ 이하의 온도범위에서 넓은 범위의 비저항값을 갖는 것을 알 수 있다.On the other hand, Figure 3 is a graph showing the resistance-temperature characteristics of the perovskite-based medium temperature thermistor according to the present invention, it is selected from the composition of Table 1, and having a specific resistance of a wide range in the temperature range of 400 ℃ or less Able to know.
이상, 상기 내용은 바람직한 일 실시예를 단지 예시한 것으로 본 발명의 당업자는 본 발명의 요지를 변경시킴 없이 본 발명에 대한 수정 및 변경을 가할 수 있음을 인지해야 한다.In the foregoing description, it should be understood that those skilled in the art can make modifications and changes to the present invention without changing the gist of the present invention as it merely illustrates one preferred embodiment.
따라서 본 발명에 따르면, 400℃이하의 중간온도 범위에서 안정된 결정구조와 적당한 저항값 및 B 정수를 갖는 중온용 써미스터 조성물을 제공함으로써 전자렌지, 가스렌지, 가스오븐, 급탕기, 조리기 등 가정용 전기 및 가스기구나 반응조, 건조로 등에 적용하여 신뢰성을 향상시키는 효과를 가져올 수 있다.Therefore, according to the present invention, by providing a medium temperature thermistor composition having a stable crystal structure, moderate resistance value and B constant in the intermediate temperature range of 400 ° C or less, electric household appliances such as microwave ovens, stoves, gas ovens, water heaters, cookers, etc. It can be applied to a mechanism, a reaction tank, a drying furnace, or the like to bring about an effect of improving reliability.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019960077882A KR100190271B1 (en) | 1996-12-30 | 1996-12-30 | Thermister composition of ferovskite system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019960077882A KR100190271B1 (en) | 1996-12-30 | 1996-12-30 | Thermister composition of ferovskite system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR19980058557A true KR19980058557A (en) | 1998-10-07 |
| KR100190271B1 KR100190271B1 (en) | 1999-06-01 |
Family
ID=19492709
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1019960077882A KR100190271B1 (en) | 1996-12-30 | 1996-12-30 | Thermister composition of ferovskite system |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR100190271B1 (en) |
-
1996
- 1996-12-30 KR KR1019960077882A patent/KR100190271B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| KR100190271B1 (en) | 1999-06-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4891158A (en) | Oxide semiconductor for thermistor and manufacturing method thereof | |
| KR20170016805A (en) | Semiconductive ceramic composition and ptc thermistor | |
| US5858902A (en) | Semiconducting ceramic compounds having negative resistance-temperature characteristics with critical temperatures | |
| JP2004221519A (en) | Sintered compact for thermistor element and manufacturing method therefor,thermistor element and temperature sensor | |
| KR100190271B1 (en) | Thermister composition of ferovskite system | |
| KR930005249B1 (en) | Metal-oxide system thermistor | |
| KR100225499B1 (en) | Material of metallic oxide system thermistor using for high temperature | |
| KR980009198A (en) | Dielectric ceramic composition | |
| KR100190270B1 (en) | Thermister composition of metal oxide system | |
| KR100225500B1 (en) | Material of ilimenite system thermistor using for high temperature | |
| KR100225501B1 (en) | Material of ilimenite system thermistor using for middle temperature | |
| KR100225498B1 (en) | Material of ferovskite system thermistor | |
| JP4990072B2 (en) | Thermistor for high temperature | |
| KR0135637B1 (en) | Thermister composition | |
| JPS6143841B2 (en) | ||
| JP3598177B2 (en) | Voltage non-linear resistor porcelain | |
| KR100941522B1 (en) | Lead free ceramic composition for ptc thermistor and ptc thermistor thereby | |
| JP2003335578A (en) | Voltage-dependent nonlinear resistor | |
| KR940011793B1 (en) | Ceramic humidity sensor | |
| JPH06163204A (en) | Semiconducting bismuth-layer-form structure oxide and ptc thermistor element | |
| JP2002222703A (en) | Voltage-dependent nonlinear resistor porcelain and its manufacturing method | |
| JPS6191060A (en) | Thermistor for high temperature | |
| JPS6246958A (en) | Pyroelectric ceramic material | |
| JPH0543161B2 (en) | ||
| JPH11116326A (en) | Thermistor with positive characteristic and its production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant | ||
| FPAY | Annual fee payment |
Payment date: 20021231 Year of fee payment: 5 |
|
| LAPS | Lapse due to unpaid annual fee | ||
| FPAY | Annual fee payment |
Payment date: 20160810 Year of fee payment: 20 |