JP3189341B2 - Composite varistor - Google Patents
Composite varistorInfo
- Publication number
- JP3189341B2 JP3189341B2 JP33630691A JP33630691A JP3189341B2 JP 3189341 B2 JP3189341 B2 JP 3189341B2 JP 33630691 A JP33630691 A JP 33630691A JP 33630691 A JP33630691 A JP 33630691A JP 3189341 B2 JP3189341 B2 JP 3189341B2
- Authority
- JP
- Japan
- Prior art keywords
- varistor
- composite
- voltage
- sintered body
- green sheet
- 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 - Lifetime
Links
Landscapes
- Thermistors And Varistors (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、例えばノイズ吸収素子
として採用されるＳｒＴｉＯ3 系複合バリスタに関し、
特に高いバリスタ電圧を得ながらサージ耐量を向上でき
るようにした構造に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an SrTiO 3 composite varistor used as a noise absorbing element, for example.
In particular, the present invention relates to a structure capable of improving a surge withstand voltage while obtaining a high varistor voltage.
【０００２】[0002]
【従来の技術】電圧非直線特性を利用してノイズを吸収
するようにしたＳｒＴｉＯ3 系バリスタは、静電容量が
大きいことから、コンデンサとしても有用な複合バリス
タとして知られている。このような複合バリスタは、従
来、セラミック粉末をプレス成形して成形体を形成し、
この成形体を還元性雰囲気中で高温焼成して焼結体を形
成し、しかる後この焼結体にＮａ等の１価金属酸化物や
その化合物を拡散させることによって結晶粒界に電気的
障壁を形成し、これにより電圧非直線特性を得ている。2. Description of the Related Art An SrTiO 3 -based varistor which absorbs noise by utilizing a voltage nonlinear characteristic is known as a composite varistor which is useful also as a capacitor because of its large capacitance. Conventionally, such a composite varistor is formed by pressing a ceramic powder to form a compact,
The molded body is fired at a high temperature in a reducing atmosphere to form a sintered body, and thereafter, a monovalent metal oxide such as Na or a compound thereof is diffused into the sintered body, so that an electric barrier is formed at crystal grain boundaries. Is formed, thereby obtaining a voltage non-linear characteristic.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら上記従来
の複合バリスタでは、焼結体に酸化物等が均一に拡散し
難いことから、焼結体の厚さを厚くしたり，高いバリス
タ電圧を得ようとすると、サージ耐量が悪化するという
問題点がある。However, in the above-mentioned conventional composite varistor, it is difficult to uniformly diffuse oxides and the like into the sintered body. Therefore, it is necessary to increase the thickness of the sintered body and obtain a high varistor voltage. Then, there is a problem that the surge withstand capacity is deteriorated.
【０００４】本発明は上記従来の状況に鑑みてなされた
もので、高いバリスタ電圧を得ながら、サージ耐量を向
上できる複合バリスタを提供することを目的としてい
る。The present invention has been made in view of the above-mentioned conventional circumstances, and has as its object to provide a composite varistor capable of improving surge withstand voltage while obtaining a high varistor voltage.
【０００５】[0005]
【課題を解決するための手段】本発明は、半導体セラミ
ックからなるグリーンシートを複数枚積層して積層体を
形成するとともに、該積層体を一体焼結して焼結体を形
成し、該焼結体に１価金属酸化物又はその化合物を拡散
させた複合バリスタにおいて、上記グリーンシートの表
面にカーボン又は有機化合物を被覆形成したことを特徴
としている。SUMMARY OF THE INVENTION According to the present invention, a plurality of green sheets made of a semiconductor ceramic are laminated to form a laminate, and the laminate is integrally sintered to form a sintered body. In a composite varistor in which a monovalent metal oxide or a compound thereof is diffused in the aggregate, carbon or an organic compound is coated on the surface of the green sheet.
【０００６】[0006]
【作用】本発明に係る複合バリスタによれば、グリーン
シートの表面にカーボン，有機化合物を被覆形成したの
で、積層したグリーンシートの接合面におけるポアの形
成を促し、もって１価金属酸化物等の拡散を促進できる
とともに、酸素を十分に供給できる。その結果、肉厚を
厚くしたり，バリスタ電圧を高く設定したりしても、サ
ージ耐量を向上できる。According to the composite varistor according to the present invention, since the surface of the green sheet is coated with carbon or an organic compound, the formation of pores at the bonding surfaces of the laminated green sheets is promoted, and thus the monovalent metal oxide or the like is formed. Diffusion can be promoted and oxygen can be sufficiently supplied. As a result, even when the thickness is increased or the varistor voltage is set high, the surge withstand capability can be improved.
【０００７】[0007]
【実施例】以下、本発明の実施例を図について説明す
る。図１は本発明の一実施例による複合バリスタを説明
するための図である。本実施例では、本発明の複合バリ
スタを製造し、これにより得られたバリスタの効果を確
認するために行った試験について説明する。まず、本実
施例の複合バリスタの製造方法について説明する。Ｓｒ
ＣＯ3 ，ＣａＣＯ3 ，ＴｉＯ2 ，及びＥｒ2 Ｏ3 の各原
料粉をそれぞれＳｒ0.9 Ｃａ0.1 Ｅｒ0.005 ＴｉＯ3 と
なるよう配合し、これに純水を加えてボールミルで混合
する。これをフィルタで脱水，乾燥させるとともに、メ
ッシュで造粒した後、1200℃で２時間仮焼成する。BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a view for explaining a composite varistor according to one embodiment of the present invention. Example 1 In this example, a composite varistor of the present invention was manufactured, and a test performed to confirm the effect of the obtained varistor will be described. First, a method for manufacturing the composite varistor of this embodiment will be described. Sr
Each raw material powder of CO 3 , CaCO 3 , TiO 2 , and Er 2 O 3 is blended so as to be Sr 0.9 Ca 0.1 Er 0.005 TiO 3, and pure water is added thereto and mixed with a ball mill. This is dehydrated and dried with a filter, granulated with a mesh, and calcined at 1200 ° C. for 2 hours.
【０００８】次に、上記仮焼成体を乾式粉砕した後、こ
の仮焼成粉末にＳｉＯ2 を0.5 wt％の割合で添加し、こ
れに純水を加えてボールミルで混合，粉砕してスラリー
を形成する。次いで、このスラリーにバインダを混合
し、ドクターブレード法により厚さ100 μm のセラミッ
クシートを形成する。Next, after the above-mentioned calcined body is dry-pulverized, 0.5 wt% of SiO 2 is added to the calcined powder, pure water is added thereto, and the mixture is mixed and pulverized with a ball mill to form a slurry. I do. Next, a binder is mixed with the slurry, and a ceramic sheet having a thickness of 100 μm is formed by a doctor blade method.
【０００９】次いで、図１（ａ）に示すように、上記セ
ラミックシートを矩形状に切断して多数のグリーンシー
ト１ａを形成する。そして、各グリーンシート１ａの表
面にポリビニルアルコール，カーボンを塗布し、この各
グリーンシート１ａを２１枚積層するとともに、この積
層方向に２ｔ／ｃｍ2 の圧力を加えて圧着し、これによ
り積層体１を形成し、この積層体１を１０．５ｍｍ×１
０．５ｍｍの大きさになるようカットする。Next, as shown in FIG. 1 (a), the green sheet 1a is formed by cutting the ceramic sheet into a rectangular shape. Then, polyvinyl alcohol and carbon are applied to the surface of each green sheet 1a, and 21 sheets of each green sheet 1a are laminated, and a pressure of 2 t / cm 2 is applied in the laminating direction to press-bond, whereby the laminate 1 Is formed, and the laminate 1 is 10.5 mm × 1
Cut to a size of 0.5 mm.
【００１０】次に、上記積層体１を空気中にて500 ℃×
２時間熱処理してバインダを燃焼させた後、1200℃に昇
温して２時間焼成し、続いて還元性雰囲気に置換して14
00℃で１時間焼成して焼結体１´を得る。これにより結
晶粒子の異常成長が抑制されて粒径が均一化されるとと
もに、上記積層体１の各グリーンシート１ａの接合面に
ポアが形成されることとなる。ここで、上記焼結体１´
の大きさは各辺が8.5mm ×8.5mm で厚さが1.7mm であっ
た。Next, the laminate 1 is placed in air at 500 ° C. ×
After heat treating the binder for 2 hours to burn the binder, the temperature is raised to 1200 ° C. and calcined for 2 hours.
It is fired at 00 ° C. for 1 hour to obtain a sintered body 1 ′. As a result, abnormal growth of crystal grains is suppressed and the grain size is made uniform, and pores are formed on the bonding surfaces of the green sheets 1 a of the laminate 1. Here, the sintered body 1 '
The size of each was 8.5 mm x 8.5 mm on each side and 1.7 mm in thickness.
【００１１】次に、上記焼結体１´に面取り加工を施し
た後、これをアルミナ磁器ポット内に収容し、この磁器
ポット内にＮａをＮａＣＯ3 に換算して0.5 wt％添加す
る。次いで、上記アルミナ磁器ポットを回転させながら
1250℃で３時間熱処理する。この熱処理によって上記焼
結体１´の結晶粒界にこれのポアからＮａ酸化物が拡散
されるとともに、酸素が供給されることとなる。Next, after the above-mentioned sintered body 1 'is chamfered, it is accommodated in an alumina porcelain pot, and 0.5 wt% of Na is added to the porcelain pot in terms of NaCO 3 . Next, while rotating the alumina porcelain pot,
Heat treatment at 1250 ° C for 3 hours. By this heat treatment, Na oxide is diffused from the pores into the crystal grain boundaries of the sintered body 1 ', and oxygen is supplied.
【００１２】次いで、上記焼結体１´の両主面にＡｇペ
ーストを塗布した後、焼き付けて６mm×６mmの大きさの
電極２を形成する。この場合、この電極２の角部にｒ＝
1.0mm 程度のアール部Ｒを形成する。最後に、上記両電
極２にリード線を半田付け接続し、上記焼結体１´の外
表面部分に外装樹脂をコーティングする。これにより本
実施例の複合バリスタ３が製造される。Next, an Ag paste is applied to both main surfaces of the sintered body 1 'and baked to form an electrode 2 having a size of 6 mm × 6 mm. In this case, r =
A round portion R of about 1.0 mm is formed. Finally, lead wires are connected to the two electrodes 2 by soldering, and the outer surface of the sintered body 1 'is coated with an exterior resin. Thereby, the composite varistor 3 of the present embodiment is manufactured.
【００１３】[0013]
【表１】 [Table 1]
【００１４】[0014]
【表２】 [Table 2]
【００１５】表１は本発明の成立過程における複合バリ
スタの試験結果を示す。この試験は、ポリビニルアルコ
ール，カーボンを塗布していない多数の比較例試料を上
記製造方法にて作成し、この比較例試料のバリスタ電圧
Ｖ1mA ，非直線係数α，静電容量ｎＦ，及び３０００Ａ
サージ後のバリスタ電圧の変化率％を測定した。この３
０００Ａサージは８×２０μｓｅｃの三角電流波を５分
間隔で２回印加した後のＶ1mA の変化を測定した。ま
た、比較するために従来の複合バリスタを作成し、この
従来試料についても同様の測定を行った。この従来試料
は、上述の製造工程において形成されたスラリーにバイ
ンダを混合した後、スプレー乾燥，造粒してセラミック
粉末を形成し、この粉末をプレスにより３．５ｔ／ｃｍ
2 の圧力を加えて１０ｍｍ×１０ｍｍ，厚さ２．０ｍｍ
の成形体を形成した。表１からも明らかなように、従来
試料の場合は、バリスタ電圧が４１３Ｖ，非直線係数が
１６．３，静電容量が６．７ｎＦとなっており、また３
０００Ａサージ後のバリスタ電圧の変化率は−１８．３
％と大きく、サージ耐量が悪化している。これに対して
比較例試料の場合は、バリスタ電圧が４７６Ｖ，非直線
係数が１７．５，静電容量が７．１ｎＦと少し向上して
おり、バリスタ電圧の変化率は−２．１％と小さくなっ
ている。これによりグリーンシートを積層することによ
って高電圧を得ながらサージ耐量を向上できることがわ
かる。Table 1 shows the test results of the composite varistor in the process of establishing the present invention. In this test, a number of comparative samples not coated with polyvinyl alcohol and carbon were prepared by the above-described manufacturing method, and the varistor voltage V 1 mA , nonlinear coefficient α, capacitance nF, and 3000 A of the comparative samples were obtained.
The change rate% of the varistor voltage after the surge was measured. This 3
000A surge measured the change of V 1mA after applying twice a triangular current wave of 8 × 20 .mu.sec at 5 minute intervals. Further, a conventional composite varistor was prepared for comparison, and the same measurement was performed on this conventional sample. This conventional sample is prepared by mixing a binder with the slurry formed in the above-described manufacturing process, spray drying and granulating to form a ceramic powder, and pressing this powder by 3.5 t / cm.
Apply pressure 2 and apply 10mm × 10mm, 2.0mm thick
Was formed. As is clear from Table 1, in the case of the conventional sample, the varistor voltage was 413 V, the nonlinear coefficient was 16.3, and the capacitance was 6.7 nF.
Variation of varistor voltage after 000A surge is -18.3
%, And the surge withstand capability is degraded. On the other hand, in the case of the comparative example, the varistor voltage was slightly improved to 476 V, the nonlinear coefficient was 17.5, and the capacitance was 7.1 nF, and the varistor voltage change rate was -2.1%. It is getting smaller. This shows that the surge withstand capability can be improved while obtaining a high voltage by laminating the green sheets.
【００１６】表２は、本発明に係る複合バリスタの効果
を確認するために行った試験結果を示す。この試験は、
各グリーンシート１ａの表面にポリビニルアルコール，
カーボンを塗布して本実施例の複合バリスタを製造し、
これのバリスタ電圧Ｖ1mA ，非直線係数α，静電容量ｎ
Ｆ，及び３０００Ａサージ後のバリスタ電圧の変化率％
を測定した。表２に示すように、グリーンシートにポリ
ビニルアルコールを塗布した場合は、バリスタ電圧が４
５８Ｖ，非直線係数が１７．１，静電容量が６．８ｎＦ
で、バリスタ電圧の変化率は−２．３％となっている。
またカーボンを塗布した場合は、バリスタ電圧が４７９
Ｖ，非直線係数が１７．６，静電容量が６．４ｎＦで、
バリスタ電圧の変化率は−１．９％となっており、この
場合にも高電圧を得ながらサージ耐量を向上できること
がわかる。Table 2 shows the results of tests performed to confirm the effects of the composite varistor according to the present invention. This exam is
Polyvinyl alcohol on the surface of each green sheet 1a,
The composite varistor of this embodiment is manufactured by applying carbon,
The varistor voltage V1mA , the nonlinear coefficient α, the capacitance n
Variation rate of varistor voltage after F and 3000A surge%
Was measured. As shown in Table 2, when polyvinyl alcohol was applied to the green sheet, the varistor voltage was 4
58V, non-linear coefficient 17.1, capacitance 6.8nF
Thus, the change rate of the varistor voltage is -2.3%.
When carbon is applied, the varistor voltage is 479
V, the nonlinear coefficient is 17.6, the capacitance is 6.4 nF,
The rate of change of the varistor voltage is -1.9%, indicating that the surge withstand voltage can be improved while obtaining a high voltage in this case as well.
【００１７】[0017]
【発明の効果】以上のように本発明に係る複合バリスタ
によれば、セラミックグリーンシートの表面にカーボン
又は有機化合物を被覆形成したので、グリーンシートの
接合面におけるポアの形成を促し、ひいては金属酸化物
等の拡散，酸素の供給を促進できることから、高いバリ
スタ電圧を得ながらサージ耐量を向上できる効果があ
る。As described above, according to the composite varistor according to the present invention, since the surface of the ceramic green sheet is coated with carbon or an organic compound, the formation of pores at the bonding surface of the green sheet is promoted, and the metal oxide is thereby oxidized. Since the diffusion of substances and the supply of oxygen can be promoted, the surge immunity can be improved while a high varistor voltage is obtained.
【図１】本発明の一実施例による複合バリスタを説明す
るための図である。FIG. 1 is a view for explaining a composite varistor according to one embodiment of the present invention.
１ 積層体 １´ 焼結体 １ａ グリーンシート ３ 複合バリスタ DESCRIPTION OF SYMBOLS 1 Laminated body 1 'Sintered body 1a Green sheet 3 Composite varistor
───────────────────────────────────────────────────── フロントページの続き (72)発明者 服部 康次 京都府長岡京市天神２丁目26番10号 株 式会社村田製作所内 (56)参考文献 特開 平１−295403（ＪＰ，Ａ) 特開 昭59−215701（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H01C 7/10 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Koji Hattori 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Murata Manufacturing Co., Ltd. (56) References JP-A-1-295403 (JP, A) JP 59-215701 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) H01C 7/10
Claims (1)
トを複数枚積層して積層体を形成するとともに、該積層
体を一体焼結して焼結体を形成し、該焼結体に１価金属
酸化物又はその化合物を拡散させた複合バリスタにおい
て、上記グリーンシートの表面にカーボン又は有機化合
物を被覆形成したことを特徴とする複合バリスタ。1. A laminated body is formed by laminating a plurality of green sheets made of a semiconductor ceramic, and the laminated body is integrally sintered to form a sintered body, and a monovalent metal oxide is formed on the sintered body. Or a compound varistor with the compound diffused
Carbon or organic compound on the surface of the green sheet
A composite varistor characterized in that an object is formed by coating .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33630691A JP3189341B2 (en) | 1991-11-25 | 1991-11-25 | Composite varistor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33630691A JP3189341B2 (en) | 1991-11-25 | 1991-11-25 | Composite varistor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05152106A JPH05152106A (en) | 1993-06-18 |
| JP3189341B2 true JP3189341B2 (en) | 2001-07-16 |
Family
ID=18297751
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33630691A Expired - Lifetime JP3189341B2 (en) | 1991-11-25 | 1991-11-25 | Composite varistor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3189341B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016070280A (en) * | 2014-10-01 | 2016-05-09 | 周 文三 | Air compressor structure |
-
1991
- 1991-11-25 JP JP33630691A patent/JP3189341B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016070280A (en) * | 2014-10-01 | 2016-05-09 | 周 文三 | Air compressor structure |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05152106A (en) | 1993-06-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0437613A1 (en) | Laminated and grain boundary insulated type semiconductor ceramic capacitor and method of producing the same | |
| JPH0524646B2 (en) | ||
| JP2757587B2 (en) | Grain boundary insulating semiconductor ceramic capacitor and method of manufacturing the same | |
| JPH06302403A (en) | Lamination type semiconductor ceramic element | |
| JPH0226775B2 (en) | ||
| JP3189341B2 (en) | Composite varistor | |
| JPH06151103A (en) | Laminated semiconductor porcelain composition | |
| JP2727626B2 (en) | Ceramic capacitor and method of manufacturing the same | |
| JPH11340090A (en) | Manufacture of grain boundary insulated multilayer ceramic capacitor | |
| JP2705221B2 (en) | Ceramic capacitor and method of manufacturing the same | |
| JPH1012043A (en) | Conductive composition and boundary layer ceramic capacitor | |
| JP2697095B2 (en) | Ceramic capacitor and method of manufacturing the same | |
| JP2956131B2 (en) | Strontium titanate-based semiconductor porcelain and method of manufacturing the same | |
| JPH0722208A (en) | Composite varistor | |
| JPH0547589A (en) | Intergranular insulation type semiconductor ceramic capacitor | |
| JP2707706B2 (en) | Grain boundary insulating semiconductor ceramic capacitor and method of manufacturing the same | |
| JPH08222468A (en) | Ceramic element and manufacture thereof | |
| JP3240689B2 (en) | Laminated semiconductor porcelain composition | |
| JP2850355B2 (en) | Ceramic capacitor and method of manufacturing the same | |
| JPS63219115A (en) | Manufacture of laminated semiconductor porcelain electronic component | |
| JP2934388B2 (en) | Manufacturing method of semiconductor porcelain | |
| JP2737280B2 (en) | Ceramic capacitor and method of manufacturing the same | |
| JP2646734B2 (en) | Ceramic capacitor and method of manufacturing the same | |
| JP3223462B2 (en) | Method for producing reduction-reoxidation type varistor | |
| JP2743448B2 (en) | Ceramic capacitor and method of manufacturing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20010417 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090518 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090518 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100518 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100518 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110518 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120518 Year of fee payment: 11 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120518 Year of fee payment: 11 |