JPH08195302A - Positive temperature coefficient thermistor - Google Patents
Positive temperature coefficient thermistorInfo
- Publication number
- JPH08195302A JPH08195302A JP569095A JP569095A JPH08195302A JP H08195302 A JPH08195302 A JP H08195302A JP 569095 A JP569095 A JP 569095A JP 569095 A JP569095 A JP 569095A JP H08195302 A JPH08195302 A JP H08195302A
- Authority
- JP
- Japan
- Prior art keywords
- temperature coefficient
- positive
- resistance
- temperature
- main material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
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- Thermistors And Varistors (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、例えば温度補償装置、
カラーTV消磁装置、電流制御などの各種スイッチング
素子あるいは定温発熱体として利用される正特性サーミ
スタに関するものである。BACKGROUND OF THE INVENTION The present invention relates to a temperature compensator,
The present invention relates to a PTC thermistor used as a color TV degaussing device, various switching elements for current control, or a constant temperature heating element.
【0002】[0002]
【従来の技術】従来の正特性サーミスタの断面図を図2
に示す。円板状ペレットのPTCサーミスタ材料5の表
裏両面に電極1a,1bを設けた構造になっている。2. Description of the Related Art A cross-sectional view of a conventional positive temperature coefficient thermistor is shown in FIG.
Shown in It has a structure in which electrodes 1a and 1b are provided on both front and back surfaces of a PTC thermistor material 5 which is a disk-shaped pellet.
【0003】従来、このような正特性サーミスタ素子の
製造方法として一種類の材料を乾式あるいは湿式成形に
より所定の円板状の形状に成形し、その後焼成過程を経
てその後電極を付け目的の正特性サーミスタ素子を得て
いた。そして、上記正特性サーミスタ素子の抵抗値を増
加または減少させる製造方法としては、焼成時の酸素雰
囲気コントロール、焼成キープ時間延長及び冷却時の徐
冷などによる方法が一般的である。Conventionally, as a method of manufacturing such a positive temperature coefficient thermistor element, one kind of material is molded into a predetermined disk shape by dry or wet molding, and then a firing process is performed to attach an electrode thereafter. I was getting a thermistor element. As a manufacturing method for increasing or decreasing the resistance value of the positive temperature coefficient thermistor element, a method of controlling an oxygen atmosphere during firing, extending the firing keeping time, and gradually cooling during cooling is generally used.
【0004】[0004]
【発明が解決しようとする課題】上記のような焼成によ
るコントロール方法では、抵抗値の増加と共に正の抵抗
温度係数も増加してしまう。正特性サーミスタはキュリ
ー温度にて抵抗値が急激に増加する性質を有しており、
これは結晶粒界部に形成されるポテンシャル障壁に起因
するもので、障壁が高くなるほど抵抗変化率は大きくな
り正の抵抗温度係数は増加する。そして、この障壁の高
さは吸着酸素量に比例する。つまり、上述の焼成方法で
は吸着酸素量が増加する為抵抗値の増加と共に正の抵抗
温度係数も増加してしまうこととなるのである。In the control method by firing as described above, the positive resistance temperature coefficient also increases as the resistance value increases. Positive temperature coefficient thermistors have the property that the resistance value increases rapidly at the Curie temperature.
This is due to the potential barrier formed at the crystal grain boundary portion. The higher the barrier, the greater the rate of resistance change and the more positive the temperature coefficient of resistance. The height of this barrier is proportional to the amount of adsorbed oxygen. That is, since the amount of adsorbed oxygen increases in the above-mentioned firing method, the positive resistance temperature coefficient also increases as the resistance value increases.
【0005】従って、電流制御などの各種スイッチング
素子として利用した場合、抵抗値によって正の抵抗温度
係数が異なるため、異なる抵抗値で同一の電流時間特性
を得る事ができず、抵抗値が異なることによって要求さ
れる特性を満足することができなくなるという問題点を
有していた。Therefore, when used as various switching elements for current control or the like, since the positive resistance temperature coefficient differs depending on the resistance value, the same current-time characteristic cannot be obtained with different resistance values, and the resistance values differ. However, there is a problem in that the characteristics required by the above cannot be satisfied.
【0006】以上の点に鑑み本発明は、異なる抵抗値で
同等の正の抵抗温度係数を有する正特性サーミスタを提
供することを目的とする。In view of the above points, an object of the present invention is to provide a positive temperature coefficient thermistor having different resistance values and having the same positive temperature coefficient of resistance.
【0007】[0007]
【課題を解決するための手段】この目的を達成するため
に本発明は、チタン酸バリウムを主成分とする正特性サ
ーミスタの主材料からなる表裏面部の2層と上記主材料
と正の抵抗温度係数が同等でかつ比抵抗の異なる副材料
からなる中間層との3層に構成するものである。In order to achieve this object, the present invention provides two layers of front and back surfaces made of the main material of a positive temperature coefficient thermistor containing barium titanate as a main component, the main material and the positive resistance temperature. It is composed of three layers including an intermediate layer made of sub-materials having the same coefficient and different specific resistances.
【0008】[0008]
【作用】この構成により、中間層の比抵抗が主材料より
も高い為正特性サーミスタ素子全体の抵抗値が増加し、
中間層と表裏層との厚みの割合によって抵抗値を調整す
ることができる。また、3層各々の正の抵抗温度係数が
同等のため、抵抗値が異なっても正の抵抗温度係数は同
等になる。これにより、異なる抵抗値にても同一の電流
時間特性(発熱特性)を得ることができる。With this configuration, since the resistivity of the intermediate layer is higher than that of the main material, the resistance value of the entire positive temperature coefficient thermistor element increases,
The resistance value can be adjusted by the ratio of the thicknesses of the intermediate layer and the front and back layers. Further, since the positive resistance temperature coefficients of the three layers are the same, the positive resistance temperature coefficients are the same even if the resistance values are different. As a result, the same current-time characteristic (heat generation characteristic) can be obtained even with different resistance values.
【0009】[0009]
【実施例】以下に本発明の実施例について説明する。本
実施例では電流制御などに用いられるスイッチング素子
を例として用いた。先ず主材料を作成するのにキュリー
温度:120℃となるように市販のBaCO3、Ti
O2、PbO、SrCO3、Y2O3、Al2O3、Mn(N
O3)2及びCaTiO3を秤量し、原料280gを4寸
ポットに入れ純水350ccと直径5mmのYTZボール6
00gとを加え20時間湿式混合し、150℃で乾燥し
た。その後、この混合物を粗砕し1100℃で2時間仮
焼し、次に、仮焼粉を4寸ポットに入れ純水300ccと
直径5mmのYTZボール600gとを加え20時間湿式
粉砕した後150℃で乾燥した。次に、得られた粉砕粉
に5%ポリビニルアルコール水溶液を10wt%加え、
ライカイ機で5分間造粒した後20メッシュパスして造
粒粉を得た。この造粒粉を表裏の両面部の2層用とす
る。その後組成比は主材料よりもTiO2とCaTiO3
の二者の混合比率を多くした副材料で、同様の方法で中
間層用の造粒粉を得た。そして、(表1)に示す割合に
粉体を秤量し直径10mmの成形金型に2b部の量を入れ
て仮プレスし、次に3部の量を入れて仮プレスし、最後
に2a部の量を入れて1000kg/cm2の圧力で本プレ
スしディスク形状に成形した。次に、その成形物を焼成
炉中で300℃/hrの速度で昇温し、1300℃の温
度で1時間焼成した後、250℃/hrの降温速度で室
温まで徐冷した。その後、得られた焼結体の両面にアル
ミメタリコン溶射電極を設けて正特性サーミスタ素子を
得た。このサーミスタの断面を図1に示す。直径は約8
mmであり、厚みは2aと3と2bとを合わせて約3mmで
ある。出来上がった比抵抗は副材料のものは主材料のも
のの約2倍になっている。EXAMPLES Examples of the present invention will be described below. In this embodiment, a switching element used for current control or the like is used as an example. First, to prepare the main material, commercially available BaCO 3 and Ti are adjusted so that the Curie temperature is 120 ° C.
O 2 , PbO, SrCO 3 , Y 2 O 3 , Al 2 O 3 , Mn (N
O 3 ) 2 and CaTiO 3 are weighed, 280 g of the raw material is put in a 4 inch pot, 350 cc of pure water and YTZ ball 6 having a diameter of 5 mm
00g was added and wet-mixed for 20 hours, and dried at 150 ° C. Then, this mixture is crushed and calcined at 1100 ° C. for 2 hours, then calcined powder is put in a 4 inch pot, 300 cc of pure water and 600 g of YTZ balls having a diameter of 5 mm are added, and wet pulverized for 20 hours, and then 150 ° C. Dried in. Next, 10% by weight of a 5% polyvinyl alcohol aqueous solution was added to the obtained pulverized powder,
After granulating for 5 minutes with a Reiki machine, 20 mesh was passed to obtain granulated powder. This granulated powder is used for two layers on both the front and back sides. After that, the composition ratio was TiO 2 and CaTiO 3
A granulated powder for the intermediate layer was obtained in the same manner by using the sub-materials in which the mixing ratio of the two was increased. Then, the powder is weighed in the proportions shown in (Table 1), and the amount of 2b is put into a molding die having a diameter of 10 mm and temporarily pressed, then the amount of 3 parts is put and temporarily pressed, and finally the 2a part. Was put into a disk shape and subjected to main pressing at a pressure of 1000 kg / cm 2 . Next, the molded product was heated in a firing furnace at a rate of 300 ° C./hr, fired at a temperature of 1300 ° C. for 1 hour, and then gradually cooled to room temperature at a temperature lowering rate of 250 ° C./hr. Then, aluminum metallikon sprayed electrodes were provided on both surfaces of the obtained sintered body to obtain a positive temperature coefficient thermistor element. A cross section of this thermistor is shown in FIG. Diameter is about 8
mm, and the total thickness of 2a, 3 and 2b is about 3 mm. The finished specific resistance of the auxiliary material is about twice that of the main material.
【0010】[0010]
【表1】 [Table 1]
【0011】また、比較のため従来の方法として(表
2)に示すような焼成キープ時間及び冷却速度を設定し
たサンプルを作った。実施例は焼成条件を変えるのでは
なく、中間層の配合比を変えることによって抵抗値を高
くすることがねらいであるから、焼成条件は従来例1と
同様である。For comparison, as a conventional method, a sample having a firing keeping time and a cooling rate as shown in Table 2 was prepared. In the examples, the firing conditions are the same as those of the conventional example 1 because the resistance value is increased by changing the compounding ratio of the intermediate layer instead of changing the firing conditions.
【0012】[0012]
【表2】 [Table 2]
【0013】本実施例による正特性サーミスタ素子の抵
抗値及び正の抵抗温度係数と従来の正特性サーミスタ素
子の抵抗値及び正の抵抗温度係数を(表3)に比較して
示している。The resistance value and the positive resistance temperature coefficient of the PTC thermistor element according to this embodiment and the resistance value and the positive resistance temperature coefficient of the conventional PTC thermistor element are shown in comparison with each other (Table 3).
【0014】[0014]
【表3】 [Table 3]
【0015】(表3)において、従来例では抵抗値が異
なると、抵抗値温度係数も異なってしまっているが、本
実施例1,2,3においては、異なる抵抗値にても同等
の正の抵抗温度係数を得ることができた。従来の方法で
は抵抗値の増加と共に正の抵抗温度係数も増加してしま
う。In Table 3, when the resistance value is different in the conventional example, the temperature coefficient of resistance value is also different, but in the first, second and third embodiments, the same positive value is obtained even if the resistance value is different. The temperature coefficient of resistance of was obtained. In the conventional method, the positive temperature coefficient of resistance increases as the resistance value increases.
【0016】尚、ここで行った正特性サーミスタの抵抗
温度特性の測定方法を説明する。まず室温から300℃
までの温度変化に対する正特性サーミスタの抵抗値変化
を測定しプロットする。次に抵抗値が室温抵抗値の2倍
になる温度をキュリー温度とし、キュリー温度での抵抗
値とキュリー温度+30℃での抵抗値を求め、その抵抗
変化率を(数1)により算出し抵抗温度係数とした。The method of measuring the resistance temperature characteristic of the positive temperature coefficient thermistor performed here will be described. First, room temperature to 300 ° C
Measure and plot the change in resistance value of the PTC thermistor with respect to temperature changes up to. Next, the temperature at which the resistance value is twice the room temperature resistance value is the Curie temperature, and the resistance value at the Curie temperature and the resistance value at the Curie temperature + 30 ° C are calculated, and the resistance change rate is calculated by (Equation 1) The temperature coefficient was used.
【0017】[0017]
【数1】 [Equation 1]
【0018】[0018]
【発明の効果】以上のように本発明は、チタン酸バリウ
ムを主成分とする正特性サーミスタにおいて、主材料か
らなる2層と前記主材料と正の抵抗温度係数が同等でか
つ比抵抗の高い中間層からなる3層に構成することによ
り、異なる抵抗値にても同等の正の抵抗温度係数を有す
る正特性サーミスタが得られ、その結果、異なる抵抗値
で同一の電流時間特性を得ることができるものである。As described above, according to the present invention, in the positive temperature coefficient thermistor containing barium titanate as a main component, the two layers made of the main material have the same positive temperature coefficient of resistance as the main material and high specific resistance. By forming the intermediate layer into three layers, a positive temperature coefficient thermistor having the same positive temperature coefficient of resistance can be obtained even with different resistance values, and as a result, the same current-time characteristics can be obtained with different resistance values. It is possible.
【0019】また、抵抗値の高い層を抵抗値の低い2層
で挟み込むことの効果は、常に抵抗値の高い層1層と低
い層1層の合計2層にしてしまうと、抵抗値の高い層の
方にばかり電力がかかり発熱及び放熱が不均一となり、
表か裏かどちらか一方のみ熱膨張が大きくなり、反って
割れてしまうからである。だから本発明においても、挟
み込む方の表裏の2層はほぼ同じ厚みにするのが発熱に
よる反りがなくなる為好ましい。Further, the effect of sandwiching the layer having a high resistance value between the two layers having a low resistance value is that the layer having a high resistance value and the layer having a low resistance value are combined into a total of two layers so that the resistance value is high. Electric power is applied only to the layers and heat generation and heat dissipation become uneven,
This is because only one of the front side and the back side has a large thermal expansion and warps and cracks. Therefore, also in the present invention, it is preferable that the two layers on the front and back sides to be sandwiched have substantially the same thickness, since warpage due to heat generation is eliminated.
【図1】本発明の正特性サーミスタの断面図FIG. 1 is a sectional view of a positive temperature coefficient thermistor of the present invention.
【図2】従来例の正特性サーミスタの断面図FIG. 2 is a cross-sectional view of a conventional positive temperature coefficient thermistor.
1a 表面電極 1b 裏面電極 2a 主材料の表面層 2b 主材料の裏面層 3 中間層 1a Front surface electrode 1b Back surface electrode 2a Main material front surface layer 2b Main material back surface layer 3 Intermediate layer
Claims (2)
の主材料からなる表裏面部の2層と、上記主材料と正の
抵抗温度係数が同等でかつ比抵抗の異なる副材料からな
る中間層とを備えた正特性サーミスタ。1. A front and back surface two layer composed of a main material of barium titanate having a positive characteristic as a main component, and an intermediate layer composed of a sub material having a positive temperature coefficient of resistance equal to that of the main material and a different specific resistance. Positive temperature coefficient thermistor with and.
1記載の正特性サーミスタ。2. The positive temperature coefficient thermistor according to claim 1, wherein the two layers of the front and back surfaces have the same layer thickness.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP569095A JPH08195302A (en) | 1995-01-18 | 1995-01-18 | Positive temperature coefficient thermistor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP569095A JPH08195302A (en) | 1995-01-18 | 1995-01-18 | Positive temperature coefficient thermistor |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH08195302A true JPH08195302A (en) | 1996-07-30 |
Family
ID=11618105
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP569095A Pending JPH08195302A (en) | 1995-01-18 | 1995-01-18 | Positive temperature coefficient thermistor |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH08195302A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005512317A (en) * | 2001-12-04 | 2005-04-28 | エプコス アクチエンゲゼルシャフト | Electrical device with negative temperature coefficient |
WO2012036142A1 (en) * | 2010-09-17 | 2012-03-22 | 株式会社 村田製作所 | Positive characteristic thermistor and method for manufacturing positive characteristic thermistor |
EP3761325B1 (en) * | 2019-07-01 | 2023-11-29 | Littelfuse, Inc. | Pptc device having resistive component |
-
1995
- 1995-01-18 JP JP569095A patent/JPH08195302A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005512317A (en) * | 2001-12-04 | 2005-04-28 | エプコス アクチエンゲゼルシャフト | Electrical device with negative temperature coefficient |
JP2010258482A (en) * | 2001-12-04 | 2010-11-11 | Epcos Ag | Electrical device with negative temperature coefficient |
WO2012036142A1 (en) * | 2010-09-17 | 2012-03-22 | 株式会社 村田製作所 | Positive characteristic thermistor and method for manufacturing positive characteristic thermistor |
EP3761325B1 (en) * | 2019-07-01 | 2023-11-29 | Littelfuse, Inc. | Pptc device having resistive component |
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