JPH0121604B2 - - Google Patents
Info
- Publication number
- JPH0121604B2 JPH0121604B2 JP57083651A JP8365182A JPH0121604B2 JP H0121604 B2 JPH0121604 B2 JP H0121604B2 JP 57083651 A JP57083651 A JP 57083651A JP 8365182 A JP8365182 A JP 8365182A JP H0121604 B2 JPH0121604 B2 JP H0121604B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- heat treatment
- sintering
- hours
- zno
- 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.)
- Expired
Links
- 238000010438 heat treatment Methods 0.000 claims description 20
- 238000005245 sintering Methods 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 2
- 238000000465 moulding Methods 0.000 claims description 2
- 239000002994 raw material Substances 0.000 claims description 2
- 230000003247 decreasing effect Effects 0.000 claims 1
- 229910015902 Bi 2 O 3 Inorganic materials 0.000 description 5
- 238000007796 conventional method Methods 0.000 description 5
- 239000013078 crystal Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001994 activation Methods 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000007725 thermal activation Methods 0.000 description 1
- 230000036962 time dependent Effects 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Thermistors And Varistors (AREA)
Description
【発明の詳細な説明】
本発明はZnOを主成分とする非直線抵抗体の製
造方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a nonlinear resistor containing ZnO as a main component.
ZnOを主成分とするZnO系素子は、優れた非直
線性を呈し、ギヤツブレス避雷器など常時課電状
態の使用を可能にする。しかし、ZnO系素子は課
電状態で微小な漏れ電流を伴い、この漏れ電流は
長期間にわたる課電で次第に増加し、熱暴走する
ことがある。このため、ZnO系素子の寿命向上に
は漏れ電流の増加率が小さいことが重要となる。
特に、近年には直流で使用できる非直線抵抗体の
要望も高く、寿命特性の良い素子開発が望まれて
いる。 ZnO-based elements, whose main component is ZnO, exhibit excellent nonlinearity and enable use in constantly energized state, such as in gear brace arresters. However, ZnO-based elements have a small leakage current when energized, and this leakage current gradually increases when energized over a long period of time, resulting in thermal runaway. Therefore, in order to improve the lifespan of ZnO-based elements, it is important that the rate of increase in leakage current is small.
In particular, in recent years there has been a high demand for nonlinear resistors that can be used with direct current, and there is a desire to develop elements with good lifetime characteristics.
これまでのZnOを主成分とする非直線抵抗体
は、焼結に1050〜1300℃の高温で１〜12時間保持
した後、100℃／hr以下の降温速度で徐冷し、そ
の後寿命特性の向上のために500〜700℃で１〜２
時間の熱処理を施している。しかし、従来方法で
は直流系統に高課電率使用するためには信頼性の
点で不充分であるし、熱処理によつて素子の低電
流域での電圧―電流特性が大きく低下する問題も
あつた。 Conventional non-linear resistors mainly composed of ZnO are sintered by holding at a high temperature of 1050 to 1300℃ for 1 to 12 hours, and then slowly cooling at a cooling rate of 100℃/hr or less. 1-2 at 500-700℃ for improvement
It has been heat treated for several hours. However, conventional methods are insufficient in terms of reliability for use in high charging rates in DC systems, and there is also the problem that heat treatment significantly degrades the voltage-current characteristics of the device in the low current range. Ta.
本発明の目的は、寿命及び電圧―電流特性を向
上した製造方法を提供することにある。 An object of the present invention is to provide a manufacturing method with improved lifespan and voltage-current characteristics.
本発明方法は1050℃〜1300℃で焼結された素子
のその後の熱処理を複数回に分けて行なうことを
特徴とする。 The method of the present invention is characterized in that the subsequent heat treatment of the element sintered at 1050°C to 1300°C is performed in multiple steps.
本発明においては、第１図に示す焼結と熱処理
パターンにする。ZnOを主成分とする原材料を混
合成形した素体は、まず1050〜1300℃で１〜12時
間の焼結を施す。この焼結工程での焼結温度まで
の昇温速度及び焼結温度からの降温速度は素子が
熱破壊しない程度に早くし、例えば300℃／hrに
して時間短縮を図る。 In the present invention, the sintering and heat treatment pattern shown in FIG. 1 is used. The element body, which is made by mixing and molding raw materials mainly composed of ZnO, is first sintered at 1,050 to 1,300 degrees Celsius for 1 to 12 hours. In this sintering process, the rate of temperature increase up to the sintering temperature and the rate of temperature decrease from the sintering temperature are set to be fast enough to prevent thermal destruction of the element, for example, to 300° C./hr to shorten the time.
上記焼結終了時の降温は300℃以下まで冷却さ
せ、素子の結晶、粒界構造の安定化を図る。300
℃以下までの降温後、保持時間Thを待つてもし
くは焼結に続いて直ちに熱処理工程に入る。その
第１段階として、焼結素子を850〜950℃まで昇温
して１〜２時間の熱処理を施し、素子内のBi2O3
層を再融解させる。この熱処理における昇降温速
度は焼結時と同様の理由から300℃／hr程度にす
る。この第１段階の熱処理において、850℃以下
ではBi2O3層が充分融解しないし、950℃以上で
はZnO結晶の熱活性化が高くなりすぎてBi2O3層
融解が粒界領域にとどまらないので思わしくな
い。また、熱処理時間は１時間以下ではその温度
に保持した効果が少なく、２時間以上ではZnO結
晶の活性化の問題が起きる。 At the end of the sintering process, the temperature is lowered to 300° C. or less in order to stabilize the crystal and grain boundary structure of the device. 300
After the temperature is lowered to below .degree. C., the heat treatment step begins immediately after waiting for the holding time Th or following sintering. As the first step, the sintered element is heated to 850-950°C and heat treated for 1-2 hours to remove Bi 2 O 3 inside the element.
Remelt the layers. The temperature increase/decrease rate in this heat treatment is set to about 300°C/hr for the same reason as in sintering. In this first stage heat treatment, the Bi 2 O 3 layer does not melt sufficiently at temperatures below 850°C, and the thermal activation of the ZnO crystal becomes too high at temperatures above 950°C, causing the Bi 2 O 3 layer to melt only in the grain boundary region. I'm not happy because there isn't one. Further, if the heat treatment time is less than 1 hour, the effect of maintaining the temperature is small, and if it is more than 2 hours, the problem of activation of the ZnO crystals occurs.
次に、熱処理の第２段階として、上記熱処理で
の降温が300℃以下に達して適当な保持時間Thを
待つてもしくは直ちに、500〜700℃まで昇温し、
この温度に１〜２時間保持して降温処理に入る。
この第２段階の熱処理により、Bi2O3層をγ相に
変態させる。このときの温度500〜700℃はBi2O3
がγ相に変化するのに必要な温度であり、またそ
の保持時間１〜２時間は前記と同様の理由から決
められる。また、昇降温速度については、昇温に
は前記と同様に300℃／hr程度にし、降温速度は
50〜150℃／hrと遅くする。これは熱歪みを取除
くなど素子特性向上に重要となる。 Next, as the second stage of heat treatment, after the temperature drop in the heat treatment reaches 300 °C or less and after waiting for an appropriate holding time Th, or immediately, the temperature is raised to 500 to 700 °C,
The temperature is maintained at this temperature for 1 to 2 hours and the temperature is lowered.
This second stage heat treatment transforms the Bi 2 O 3 layer into the γ phase. The temperature at this time is 500 to 700℃, which is Bi 2 O 3
This is the temperature required to change into the γ phase, and the holding time of 1 to 2 hours is determined for the same reasons as above. In addition, regarding the temperature increase/decrease rate, the temperature increase should be approximately 300℃/hr as described above, and the temperature decrease rate should be approximately 300℃/hr.
Slow down to 50-150℃/hr. This is important for improving device characteristics such as removing thermal distortion.
以上の焼結と熱処理を施す本発明方法による素
子は、低電流域での電圧―電流特性では第２図Ａ
に示すように特性イのものになり、従来方法によ
る特性ロのものに比して同じ課電圧に対する漏れ
電流の増加も小さく後述のように課電特性向上と
なる実験結果を得た。図中特性ハは焼結後の電圧
―電流特性である。 The device according to the method of the present invention, which undergoes the above sintering and heat treatment, has voltage-current characteristics in the low current range as shown in Figure 2A.
As shown in Figure 2, the characteristic A is obtained, and the increase in leakage current for the same applied voltage is smaller than that obtained by the conventional method with characteristic B, and as will be described later, we obtained experimental results showing that the applied voltage characteristics are improved. Characteristic C in the figure is the voltage-current characteristic after sintering.
また、本発明方法による素子は、直流印加によ
る漏れ電流の経時変化が第２図Ｂに示す特性イの
ものになり、従来方法による特性ロのものに比し
て漏れ電流の増加が少なく、長寿命が期待できる
実験結果を得た。図中特性ハは焼結後のもれ電流
の経時変化特性である。なお、第２図Ｂの実験に
おいて、直流印加は140℃温度雰囲気中で70％
V1nA課電にした。 In addition, in the device manufactured by the method of the present invention, the change in leakage current over time due to the application of direct current has the characteristic A shown in Figure 2B, and the increase in leakage current is smaller than that of the characteristic B obtained by the conventional method. We obtained experimental results that indicate a long service life. Characteristic C in the figure is the time-dependent change characteristic of the leakage current after sintering. In the experiment shown in Figure 2B, the direct current was applied at 70% in an atmosphere at a temperature of 140°C.
The voltage was set to 1nA .
こうした効果は、ZnO素子の配合に依らず認め
られた。 These effects were observed regardless of the ZnO element composition.
以上のとおり、本発明方法によれば、焼結と熱
処理の間に１回の熱処理工程を増すことにより、
従来方法に比して電圧―電流特性に優れ、寿命向
上を期待できる効果がある。また、焼結と熱処理
の連続処理にして処理時間の増分を軽減できる。 As described above, according to the method of the present invention, by adding one heat treatment step between sintering and heat treatment,
Compared to conventional methods, this method has superior voltage-current characteristics and is expected to have a longer lifespan. Further, the increase in processing time can be reduced by performing sintering and heat treatment continuously.
第１図は本発明方法における焼結と熱処理パタ
ーン図、第２図は本発明方法による素子特性を従
来方法のものと併せて示す図である。
FIG. 1 is a diagram showing the sintering and heat treatment patterns in the method of the present invention, and FIG. 2 is a diagram showing device characteristics according to the method of the present invention together with those of the conventional method.
Claims (1)
結と熱処理を施して得る非直線抵抗体の製造方法
において、1050〜1300℃で１〜12時間保持した焼
結後、一旦300℃以下に降温し、次いで850〜950
℃に昇温して１〜２時間の第１の熱処理を施し、
この熱処理後一旦300℃以下に降温し、次いで500
〜700℃に昇温して１〜２時間の第２の熱処理を
施し、この熱処理後の降温は50〜150℃／hrの降
温速度で冷却することを特徴とする非直線抵抗体
の製造方法。1 In the manufacturing method of non-linear resistors obtained by mixing and molding raw materials mainly composed of ZnO, sintering and heat treatment, after sintering which is held at 1050 to 1300℃ for 1 to 12 hours, the temperature is once lowered to below 300℃. Temperature drops, then 850-950
A first heat treatment is performed for 1 to 2 hours by raising the temperature to ℃,
After this heat treatment, the temperature was lowered to below 300℃, and then heated to 500℃.
A method for manufacturing a non-linear resistor, characterized by raising the temperature to ~700°C, performing a second heat treatment for 1 to 2 hours, and cooling after this heat treatment at a temperature decreasing rate of 50 to 150°C/hr. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57083651A JPS58200508A (en) | 1982-05-18 | 1982-05-18 | Method of producing nonlinear resistor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57083651A JPS58200508A (en) | 1982-05-18 | 1982-05-18 | Method of producing nonlinear resistor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58200508A JPS58200508A (en) | 1983-11-22 |
| JPH0121604B2 true JPH0121604B2 (en) | 1989-04-21 |
Family
ID=13808349
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57083651A Granted JPS58200508A (en) | 1982-05-18 | 1982-05-18 | Method of producing nonlinear resistor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58200508A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2816258B2 (en) * | 1991-04-23 | 1998-10-27 | 株式会社日立製作所 | Method of manufacturing voltage non-linear resistor and lightning arrester |
| EP0667626A3 (en) * | 1994-02-10 | 1996-04-17 | Hitachi Ltd | Voltage non-linear resistor and fabricating method thereof. |
-
1982
- 1982-05-18 JP JP57083651A patent/JPS58200508A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58200508A (en) | 1983-11-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5807510A (en) | Electric resistance element exhibiting voltage nonlinearity characteristic and method of manufacturing the same | |
| JPH0121604B2 (en) | ||
| US5707583A (en) | Method for preparing the zinc oxide base varistor | |
| US3533966A (en) | Process for making current limiting devices | |
| US4219518A (en) | Method of improving varistor upturn characteristics | |
| JP3867135B2 (en) | Nanocrystal structure, nanocrystal structure manufacturing method, and nonlinear resistance element | |
| JPH0121603B2 (en) | ||
| JP2816258B2 (en) | Method of manufacturing voltage non-linear resistor and lightning arrester | |
| US4409728A (en) | Method of making a stable high voltage DC varistor | |
| JP3331716B2 (en) | Method for manufacturing positive characteristic semiconductor device | |
| JP2860262B2 (en) | Method of firing glazed porcelain | |
| JPH04186702A (en) | Manufacture of voltage dependent nonlinear resistor and arrestor | |
| JPH0249521B2 (en) | ||
| JPH0136681B2 (en) | ||
| JP2006045058A (en) | Nanocrystal structure, manufacturing method of the nanocrystal structure and thermoelectric element | |
| JP3286515B2 (en) | Voltage non-linear resistor | |
| JP2519374B2 (en) | Method of firing beta-alumina solid electrolyte | |
| JPS58159302A (en) | Voltage nonlinear resistor | |
| KR840002452B1 (en) | Nonlinear resistor | |
| KR100264529B1 (en) | Pct thermister | |
| US3622312A (en) | Method for rejuvenating refractory articles | |
| JPS58225602A (en) | Method of producing nonlinear resistor | |
| JPH01295402A (en) | Manufacture of zinc oxide type lightning arrestor element | |
| JPS59115503A (en) | Method of producing current limiting element | |
| JPS6338841B2 (en) |