JP2605332B2 - Method for forming grain boundary layer of semiconductor porcelain - Google Patents
Method for forming grain boundary layer of semiconductor porcelainInfo
- Publication number
- JP2605332B2 JP2605332B2 JP6238788A JP6238788A JP2605332B2 JP 2605332 B2 JP2605332 B2 JP 2605332B2 JP 6238788 A JP6238788 A JP 6238788A JP 6238788 A JP6238788 A JP 6238788A JP 2605332 B2 JP2605332 B2 JP 2605332B2
- Authority
- JP
- Japan
- Prior art keywords
- semiconductor porcelain
- diffusing agent
- grain boundary
- semiconductor
- boundary layer
- 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
- 239000004065 semiconductor Substances 0.000 title claims description 32
- 229910052573 porcelain Inorganic materials 0.000 title claims description 23
- 238000000034 method Methods 0.000 title claims description 9
- 239000003795 chemical substances by application Substances 0.000 description 23
- 238000010438 heat treatment Methods 0.000 description 12
- 239000013078 crystal Substances 0.000 description 7
- 229910044991 metal oxide Inorganic materials 0.000 description 5
- 150000004706 metal oxides Chemical class 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- 239000000919 ceramic Substances 0.000 description 4
- 239000003985 ceramic capacitor Substances 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 4
- 239000003990 capacitor Substances 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 239000002966 varnish Substances 0.000 description 2
- 229910015902 Bi 2 O 3 Inorganic materials 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000002003 electrode paste Substances 0.000 description 1
- 238000000921 elemental analysis Methods 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/002—Details
- H01G4/018—Dielectrics
- H01G4/06—Solid dielectrics
- H01G4/08—Inorganic dielectrics
- H01G4/12—Ceramic dielectrics
- H01G4/1272—Semiconductive ceramic capacitors
- H01G4/1281—Semiconductive ceramic capacitors with grain boundary layer
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Ceramic Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Ceramic Capacitors (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は半導体磁器コンデンサに用いられる半導体磁
器の粒界に金属酸化物を熱拡散する半導体磁器の粒界層
形成方法に関するものである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a grain boundary layer of a semiconductor ceramic which thermally diffuses a metal oxide to a grain boundary of the semiconductor ceramic used for a semiconductor ceramic capacitor.
従来の技術 従来、チタン酸ストロンチウム系半導体磁器は、その
結晶粒界を絶縁化することにより、大きな見掛誘電率を
持つ粒界絶縁型半導体磁器コンデンサが得られることが
知られている。この粒界絶縁型半導体磁器コンデンサは
小型で大容量が得られることから、デレビジョン受像
機，ビデオテープレコーダーのカップリング回路等に使
用され、他にも多くの分野に応用されている。2. Description of the Related Art Conventionally, it is known that a strontium titanate-based semiconductor porcelain can obtain a grain boundary insulated semiconductor porcelain capacitor having a large apparent dielectric constant by insulating crystal grain boundaries. Since the grain boundary insulated semiconductor ceramic capacitor has a small size and a large capacity, it is used for a coupling circuit of a devision receiver, a video tape recorder, and the like, and is applied to many other fields.
このような粒界絶縁型半導体磁器コンデンサの結晶粒
界の絶縁化方法としては、金属酸化物とワニスからなる
金属酸化物ペーストを半導体磁器に塗着し、乾燥後大気
中で熱処理を行うことによって結晶粒界に拡散させて絶
縁化する方法が一般的である。また、最近では上記金属
酸化物ペーストの代わりに、拡散剤の成分を有する有機
系金属石ケンと、有機系バインダよりなる混合液を半導
体磁器に塗着し、同様に熱処理する方法（特開昭59−17
228号公報参照）も行われている。熱処理は、拡散剤乾
燥後、第４図に示すような構成でアルミナ質のサヤ５に
拡散剤を塗布した半導体磁器４をバラ詰めして、アルミ
ナ質の蓋６を被せ空気中で行われている。As a method of insulating the crystal grain boundaries of such a grain boundary insulating semiconductor ceramic capacitor, a metal oxide paste composed of a metal oxide and a varnish is applied to the semiconductor ceramic, dried, and then heat-treated in the air. In general, a method of diffusing into a crystal grain boundary to insulate the crystal grain is used. Recently, instead of the above-mentioned metal oxide paste, a mixed solution of an organic metal soap having a diffusing agent component and an organic binder is applied to semiconductor porcelain and heat treated similarly (Japanese Patent Application Laid-Open No. 59-17
228). The heat treatment is performed by drying the diffusing agent, packing the semiconductor porcelain 4 coated with the diffusing agent on the alumina sheath 5 in a configuration as shown in FIG. I have.
発明が解決しようとする課題 このような従来の方法では、半導体磁器４によって空
気及びサヤ５との接触状態が異なる。従って、空気中へ
の拡散剤の蒸発や、サヤ５への拡散の条件が不均等にな
り熱処理後の拡散剤の残存量が半導体磁器４によって異
なるので、電気特性のバラツキが大きくなり歩留りの低
下を引き起こすという問題があった。Problems to be Solved by the Invention In such a conventional method, the contact state between the air and the sheath 5 differs depending on the semiconductor porcelain 4. Accordingly, the conditions for the evaporation of the diffusing agent into the air and the diffusion to the sheath 5 become uneven, and the residual amount of the diffusing agent after the heat treatment varies depending on the semiconductor porcelain 4. Therefore, the variation in the electrical characteristics increases, and the yield decreases. Had the problem of causing
本発明はこのような問題点を解決するもので、電気特
性のバラツキを低減することを目的とするものである。The present invention has been made to solve such a problem, and has as its object to reduce variations in electrical characteristics.
課題を解決するための手段 この課題を解決するために本発明は、あらかじめ均一
に拡散剤を塗着し、乾燥させた半導体磁器を互いに接す
るように規則的に並べ、前記半導体磁器をサヤの内壁に
均等に接するように詰めて熱処理することによって結晶
留界を絶縁化する方法としたものである。Means for Solving the Problems In order to solve this problem, the present invention is to uniformly disperse the diffusing agent in advance, regularly arrange the dried semiconductor porcelain so as to be in contact with each other, and connect the semiconductor porcelain to the inner wall of the sheath. In this method, the crystal boundary is insulated by packing and heat treatment so that the crystal boundary is uniformly contacted.
作用 この方法により、半導体磁器と空気及びサヤとの接触
面積を等しくすることができるため、熱処理後の拡散剤
の残存量のバラツキが減少し、電気特性のバラツキを小
さくすることができる。さらに空気中への蒸発量を抑え
ることができるので、従来と同同等の電気特性を得るに
は拡散剤塗着量を少なくできる。Effect This method makes it possible to equalize the contact area between the semiconductor porcelain, the air, and the sheath, thereby reducing the variation in the remaining amount of the diffusing agent after the heat treatment and reducing the variation in the electrical characteristics. Further, since the amount of evaporation into the air can be suppressed, the amount of the diffusing agent applied can be reduced in order to obtain the same electrical characteristics as in the past.
実施例 以下、実施例に基づき本発明を詳細に説明する。SrTi
O390モル％,CaTiO310モル％,Nb2O50.2モル％の組成比に
なるように配合し、湿式ポットミルで混合した後、乾燥
した。バインダとしてポリビニルアルコールの５％水溶
液を添加して造粒した後、30メッシュのフルイを通して
整粒し、油圧プレスを用いて直径7mm,肉厚0.4mmの円板
に1000kg/cm2の圧力で成形した。成形円板を大気中にお
いて400℃で２時間加熱した後、90％N2−10％H2の混合
ガス気流中において1420℃で２時間還元焼成して、直径
6mm,肉厚0.35mmの半導体磁器を得た。Examples Hereinafter, the present invention will be described in detail based on examples. SrTi
They were blended so as to have a composition ratio of 90 mol% of O 3 , 10 mol% of CaTiO 3 and 0.2 mol% of Nb 2 O 5 , mixed by a wet pot mill, and dried. After adding a 5% aqueous solution of polyvinyl alcohol as a binder and granulating, it is sized through a 30-mesh sieve, and formed into a disk with a diameter of 7 mm and a thickness of 0.4 mm using a hydraulic press at a pressure of 1000 kg / cm 2. did. The molded disc is heated at 400 ° C. for 2 hours in the atmosphere, and then reduced and fired at 1420 ° C. for 2 hours in a mixed gas stream of 90% N 2 -10% H 2 to obtain a diameter.
Semiconductor porcelain with a thickness of 6 mm and a thickness of 0.35 mm was obtained.
拡散剤としては、Cu2O35モル％,Bi2O365モル％とワニ
スを混練して調製した金属酸化物ペーストを用いた。As the diffusing agent, a metal oxide paste prepared by kneading 35 mol% of Cu 2 O, 65 mol% of Bi 2 O 3 and varnish was used.
この半導体磁器に所定量の拡散剤ペーストを均一に塗
着して乾燥させた後、第１図のように半導体磁器１を規
則的に並べ、第２図のように円筒状のサヤ２に詰めす
る。第１図及び第２図において、１は拡散剤を塗着した
半導体磁器、２は円筒状のアルミナ質のサヤである。第
２図のようにサヤ詰めした円筒状のサヤ２をさらに第３
図のように両端を塞ぐように熱処理用サヤ３に並べ、空
気中において1100℃で４時間熱処理した。熱処理によっ
て拡散剤は半導体磁器１の結晶粒界に拡散し、絶縁化す
る。After uniformly applying a predetermined amount of a diffusing agent paste to the semiconductor porcelain and drying, the semiconductor porcelains 1 are regularly arranged as shown in FIG. 1 and packed in a cylindrical sheath 2 as shown in FIG. I do. 1 and 2, reference numeral 1 denotes a semiconductor porcelain coated with a diffusing agent, and reference numeral 2 denotes a cylindrical alumina sheath. As shown in FIG. 2, the cylindrical sheath 2 packed with sheaths is further
As shown in the figure, the heat treatment sheath 3 was arranged so as to close both ends, and heat treatment was performed in air at 1100 ° C. for 4 hours. By the heat treatment, the diffusing agent diffuses into the crystal grain boundaries of the semiconductor porcelain 1 and becomes insulated.
比較のために所定量の拡散剤を均一に塗着して乾燥さ
せた後、第４図のようにバラ詰めして同様に熱処理を行
った。第４図において、４は拡散剤を塗着した半導体磁
器、５はアルミナ質のサヤ、６はアルミナ質の蓋であ
る。このようにして得られた粒界絶縁型半導体磁器の両
面に電極ペーストを塗布し、850℃で焼付けてコンデン
サとし、見掛誘電率，誘電損失，破壊電圧を測定し、静
電容量のバラツキを算出した。見掛誘電率及び誘電損失
は、1V,1kHzの条件で測定し、破壊電圧はコンデンサの
電極間に1mA以上の電流が流れる直前の電圧を測定し
た。静電容量のバラツキは の式より算出した。熱処理後の拡散剤残存量は発光分光
分析法による元素分析値から求めた。なお、測定は両端
部に位置した半導体磁器を除いて行った。その結果を第
１表に示す。For comparison, a predetermined amount of a diffusing agent was uniformly applied and dried, then, as shown in FIG. In FIG. 4, reference numeral 4 denotes a semiconductor porcelain coated with a diffusing agent, 5 denotes an alumina sheath, and 6 denotes an alumina lid. The electrode paste is applied to both surfaces of the thus obtained grain boundary insulated semiconductor porcelain and baked at 850 ° C. to form a capacitor. Calculated. Apparent permittivity and dielectric loss were measured under the conditions of 1 V and 1 kHz, and breakdown voltage was measured immediately before a current of 1 mA or more flowed between the electrodes of the capacitor. Variation in capacitance It calculated from the formula of. The residual amount of the diffusing agent after the heat treatment was determined from the elemental analysis value by the emission spectroscopy. In addition, the measurement was performed except for the semiconductor porcelain located at both ends. Table 1 shows the results.
第１表から明らかなように、同じ量の拡散剤を塗着し
た場合、熱処理後の半導体磁器中の拡散剤残存量は従来
の方法に比べて多く、空気中への蒸発及びサヤへの拡散
が減少したことが確認できる。また、従来法と同等の電
気特性を得るためには拡散剤塗着量を減らすことによっ
て可能となり、しかも静電容量のバラツキだけを減少さ
せることができる。 As is clear from Table 1, when the same amount of the diffusing agent is applied, the residual amount of the diffusing agent in the semiconductor porcelain after the heat treatment is larger than that of the conventional method, and the amount of the diffusing agent is evaporated into the air and diffused into the sheath. Can be confirmed to have decreased. Further, it is possible to obtain the same electrical characteristics as in the conventional method by reducing the amount of the diffusing agent applied, and it is possible to reduce only the variation in the capacitance.
発明の効果 以上のように、本発明の方法によれば、半導体磁器を
規則的に並べ、サヤと均等に接するように詰めて熱処理
することによって、拡散剤の空気中への蒸発を抑え、か
つ熱処理後の拡散剤残存量のバラツキを減少させ、電気
特性のバラツキを減少させることができる。また、拡散
剤塗着量が少なくても従来法と同等の電気特性を得るこ
とが可能であり、その際静電容量のバラツキだけを低減
させることができ、歩留り良く粒界絶縁型半導体磁器コ
ンデンサを製造できるという効果が得られる。Effect of the Invention As described above, according to the method of the present invention, semiconductor porcelain is regularly arranged, and packed and heat-treated so as to be in uniform contact with the sheath, thereby suppressing evaporation of the diffusing agent into the air, and Variations in the residual amount of the diffusing agent after the heat treatment can be reduced, and variations in electrical characteristics can be reduced. In addition, even if the amount of the diffusion agent applied is small, it is possible to obtain the same electrical characteristics as the conventional method, and at this time, it is possible to reduce only the variation in the capacitance, and to achieve a good yield with a grain boundary insulated semiconductor ceramic capacitor. Can be produced.
第１図〜第３図は本発明の一実施例による半導体磁器の
粒界層形成方法を示す工程毎の斜視図、第４図は従来法
による熱処理時を示す断面図である。 １……拡散剤を塗着した半導体磁器、２……サヤ、３…
…熱処理用サヤ。1 to 3 are perspective views showing steps of a method for forming a grain boundary layer of a semiconductor ceramic according to one embodiment of the present invention, and FIG. 4 is a cross-sectional view showing a conventional heat treatment. 1 ... semiconductor porcelain coated with a diffusing agent, 2 ... Saya, 3 ...
... Saya for heat treatment.
Claims (1)
するように規則的に並べ、前記半導体磁器を筒状のサヤ
の内壁に均等に接するように詰めて熱処理することによ
って粒界を絶縁化する半導体磁器の粒界層形成方法。1. A semiconductor porcelain coated with a diffusing agent is regularly arranged so as to be in contact with each other, and the semiconductor porcelain is packed so as to be uniformly in contact with the inner wall of a cylindrical sheath and heat treated to insulate grain boundaries. A method for forming a grain boundary layer of a semiconductor porcelain to be transformed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6238788A JP2605332B2 (en) | 1988-03-16 | 1988-03-16 | Method for forming grain boundary layer of semiconductor porcelain |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6238788A JP2605332B2 (en) | 1988-03-16 | 1988-03-16 | Method for forming grain boundary layer of semiconductor porcelain |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01235320A JPH01235320A (en) | 1989-09-20 |
| JP2605332B2 true JP2605332B2 (en) | 1997-04-30 |
Family
ID=13198664
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6238788A Expired - Lifetime JP2605332B2 (en) | 1988-03-16 | 1988-03-16 | Method for forming grain boundary layer of semiconductor porcelain |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2605332B2 (en) |
-
1988
- 1988-03-16 JP JP6238788A patent/JP2605332B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01235320A (en) | 1989-09-20 |
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