JPS6129529B2 - - Google Patents
Info
- Publication number
- JPS6129529B2 JPS6129529B2 JP53159796A JP15979678A JPS6129529B2 JP S6129529 B2 JPS6129529 B2 JP S6129529B2 JP 53159796 A JP53159796 A JP 53159796A JP 15979678 A JP15979678 A JP 15979678A JP S6129529 B2 JPS6129529 B2 JP S6129529B2
- Authority
- JP
- Japan
- Prior art keywords
- ceramic
- sheet
- ceramic dielectric
- rod
- capacitor
- 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
- 239000000919 ceramic Substances 0.000 claims description 120
- 239000003990 capacitor Substances 0.000 claims description 42
- 238000010304 firing Methods 0.000 claims description 33
- 238000000034 method Methods 0.000 claims description 21
- 239000003985 ceramic capacitor Substances 0.000 claims description 18
- 238000004804 winding Methods 0.000 claims description 18
- 238000004519 manufacturing process Methods 0.000 claims description 14
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 11
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 9
- 239000011230 binding agent Substances 0.000 claims description 9
- 239000003989 dielectric material Substances 0.000 claims description 9
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 8
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 8
- 239000002245 particle Substances 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 6
- 229910052763 palladium Inorganic materials 0.000 claims description 6
- 229910052697 platinum Inorganic materials 0.000 claims description 4
- 239000002003 electrode paste Substances 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 2
- 238000000354 decomposition reaction Methods 0.000 claims description 2
- 230000000694 effects Effects 0.000 description 13
- 239000000843 powder Substances 0.000 description 12
- 239000000463 material Substances 0.000 description 9
- DOIRQSBPFJWKBE-UHFFFAOYSA-N dibutyl phthalate Chemical compound CCCCOC(=O)C1=CC=CC=C1C(=O)OCCCC DOIRQSBPFJWKBE-UHFFFAOYSA-N 0.000 description 6
- 239000010408 film Substances 0.000 description 5
- 229910002113 barium titanate Inorganic materials 0.000 description 4
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 4
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 238000003475 lamination Methods 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 239000004014 plasticizer Substances 0.000 description 2
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 2
- 238000007650 screen-printing Methods 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 229910000679 solder Inorganic materials 0.000 description 2
- 238000005476 soldering Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000032798 delamination Effects 0.000 description 1
- 235000012438 extruded product Nutrition 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 239000013081 microcrystal Substances 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- SWELZOZIOHGSPA-UHFFFAOYSA-N palladium silver Chemical compound [Pd].[Ag] SWELZOZIOHGSPA-UHFFFAOYSA-N 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Landscapes
- Ceramic Capacitors (AREA)
- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
Description
本発明は小型で一体となつた誘電体の中にきわ
めて大きな面積の電極を有する巻回形セラミツク
コンデンサの製造方法に関するものである。
最近、電子機器の複雑化に伴つて電子回路のよ
り小型化、高密度化の傾向が強くなり、コンデン
サにおいても許容される容積的限界から極端に小
形大容量のものが求められており、これまで大容
量を得るため、高誘電率材料の開発および薄い皮
膜を安全に作るなどの技術の開発がなされてき
た。ことにコンデンサ用誘電体材料としてチタン
酸バリウムや酸化チタンやこれに類するセラミツ
ク材料の使用は他の材料においては得られない高
誘電率を有するとともに耐熱性の高い材料である
ため多くの研究がなされてきた。また、誘電体層
形成の方法においても、電極に挾んだ薄いセラミ
ツク誘電体層を幾重にも積層せしめる技術が開発
されてきた。この様なすぐれたセラミツクの特性
を生かしたコンデンサーおよびその製造方法が米
国特許第3004197号明細書の方法がある。
この方法はコンデンサの外形よりも数倍大きな
電極面積を有し、誘電体と電極が連続で、さらに
はこの両者が密着した機械的に強く取り扱い易い
小形大容量の円柱形コンデンサおよびその製造方
法を提供するものである。具体的には微粉砕した
セラミツク誘電体粉に約10〜20％wtのプラスチ
ツクを可塑剤と共に混合したスリツプを支持体基
板上に塗布乾燥して、保形性可撓性のある未焼成
セラミツクシートを作り、適当な寸法切りの後、
白金あるいはパラジウムなどの貴金属ペーストを
塗布して、これを細い未焼成セラミツク棒体の囲
りに巻回して渦巻き状とし1148℃〜1426℃の範囲
の適当な温度において焼成し、シート中の有機物
を追い出すとともにセラミツクの微結晶の成長に
よつて誘電体材料と電極を一体に固く焼き締め、
次いでその両端面部において銀電極を焼付けて端
子とし、さらにこの端子にリード線をはんだ付け
して円柱体のコンデンサとするものである。
しかし、この様な未焼成セラミツクシートを巻
回積層して焼成して得られるセラミツクコンデン
サは、その巻回積層の状態によつては、焼成後に
おいても誘電体が均一に一体化せず部分的に層間
ではく離（デラミネーシヨン）を起こすものが現
れることがある。この層はく離現象は、結果的に
は未焼成セラミツクシート中のセラミツク粒子が
層間において焼成前において充分に相互に接触し
ていなかつたため起るものであるが、層間におい
て全てのセラミツク粒子を接触の状態にするに
は、何らかの方法でシート間に圧力を加えること
が必要である。巻回形セラミツクコンデンサにお
いては、ことに引張り強度の弱い未焼成セラミツ
クシートにおいては、層間に圧力を加えることは
容易な構造ではなく、前記米国特許第3004197号
に明細書の方法においては、未焼成セラミツクシ
ート巻回後、芯にした未焼成セラミツク棒体を数
回回転せしめて巻き締めを行ない層間の圧着を行
つている。しかし未焼成セラミツクシートならび
に未焼成セラミツク棒体の機械的強度の制約上、
このような方法では十分巻き締めを行うことが容
易でなく、上述の層はく離を起こす危険性が強
い。その結果、コンデンサの吸湿特性機械的強度
の低下、さらにははんだ付け等の高温処理におい
て誘電体層の破損を起こすなどの問題がある。
本発明の目的はこれらの欠点を除去して、信頼
性の高い小形で大容量の巻回形セラミツクコンデ
ンサの製造方法を提供することである。
この目的を達成するために、金属電極ペースト
を印刷した可撓性のある未焼成セラミツク誘電体
シートよりなるシート状容量体を、シートの焼成
における収縮率より小さい収縮率を有する未焼成
セラミツク誘電体の棒体上に巻き回わして円柱形
容量体とし、これを通常のセラミツクの焼成条件
で焼成し、さらに端面に外部電極またさらに外部
電極にリード線を付けるなどして巻回形セラミツ
クコンデンサを得るものである。
以上のような本発明により得られたコンデンサ
は、未焼成セラミツクシート相互間、未焼成セラ
ミツクシートと電極間、未焼成セラミツクシート
と未焼成セラミツク棒体間の積層がきわめて緊密
で、一体化され、高密度のセラミツク焼結体が得
られ、層はく離などは全く生じない。この結果、
耐湿特性、機械的強度、ハンダ耐熱性などのすぐ
れ、しかも、小形で大容量のセラミツクコンデン
サを得ることができる。
このような本発明の効果の生ずる原因として
は、軸芯である未焼成セラミツク棒体よりも、巻
回された未焼成セラミツクシートの方が焼成にお
いて収縮率が大きいために生ずるものである。す
なわち、焼成時において、あたかも機械的な圧力
を加えるのと同じような力が巻回されたシートに
生じこれが巻き締め作用となつて現れるものであ
る。このような焼成収縮率の差を応用した巻き締
めをする方法はこの種、機械的強度の弱い未焼成
セラミツクシートを巻き回して焼成とするコンデ
ンサにおいては、きわめて工業的に有用である。
すなわち、巻き締め操作、加圧操作などが省略さ
れるだけではなく、焼成において、自ずから生ず
る圧力は外部から加える力では得られない均一で
しかも巻回形に適したものであるため、従来の方
法では得られなかつた高品質の焼成品を得ること
が出来る。
次に本発明の一実施例を図を用いて詳細に説明
する。未焼成セラミツク誘電体シートは公知の方
法によつて作られる。セラミツク誘電体材料とし
ては公知の材料組成を有する例えば酸化チタン、
あるいはチタン酸バリウムの微粉末に有機バイン
ダーとして例えばポリビニルプチラール樹脂、可
塑剤としてフタル酸ジブチルなどを適当な溶剤と
共にポールミルなどで均一に混合してスリツプを
作り、これをナイフコータ、パイプコータ、リバ
ースロールコータ、あるいはスクリーン印刷など
の方法によつて第１図に示すように表面に適当な
離形処理を施こしたフイルムベース１上に皮膜を
形成し、乾燥して所定の厚さ寸法のグリーンシー
ト２を得る。次いでこれらの未焼成セラミツクシ
ート２上にパラジウム、白金、あるいは白金−パ
ラジウムなどの貴金属導電ペーストで、複数ケの
短冊形のパターンを有する版を用いて、短冊状電
極３，４を印刷し、第２図および第３図にしめす
ような二種類の電極を設けた未焼成セラミツクシ
ート５，６を作る。この短冊形電極の長手方向の
長さは、一つのコンデンサーに巻き込まれる電極
の全長であり、短い方の長さである。
次にこれら二種類の未焼成セラミツクシートを
一方のシートの短冊形電極３の中心線７と他方の
シートの短冊形電極４の中心線８とが互にわずか
にずれる様な位置において重ね合わせて接着して
シート状容量体９とし、さらにこのシート状容量
体９を平坦な台上において、後述する未焼成セラ
ミツク棒体１０を短冊形電極４の長手方向と直角
にして適当な接着剤で容量体９の端縁１１に接着
する。第４図にこれらの関係をしめす。次いで平
面板１２で未焼成セラミツク棒体１０の上から押
えて電極長手方向に転がし、フイルムベース１か
ら容量体９を引き剥がしながら巻き込みを行な
い、最終端を適当な接着剤で固定して棒状の巻き
取り品１３を得る。次いで第６図に示されるよう
な点線１４上の位置において切断し、これを未焼
成セラミツクシートの最適な焼成条件において焼
成を行ない第７図に示すコンデンサー素体１５を
得る。さらに第８図に示すようにこの素体１５の
両端面１６，１７に銀−パラジウムを焼き付けて
外部電極１８，１９とし、あるいはまたさらに第
９図に示すように外部電極１８，１９にリード線
２０，２１をはんだなどでつけてセラミツクコン
デンサーとする。
本発明における未焼成セラミツク棒体の焼成に
おける収縮率は未焼成セラミツクシートの焼成さ
れる最適の焼成条件で焼成した時、未焼成セラミ
ツクシートの収縮率よりも小さいものでなければ
ならない。未焼成セラミツク棒体の焼成における
収縮率は、焼成条件が一定の場合これを構成する
セラミツク粉末の物理的、化学的性質、有機バイ
ンダの特性、これら構成材料の配合量ならびにグ
リーンデンシテイなどによつて決定される。具体
的には、未焼成セラミツクシートと同一組成のセ
ラミツクならびに有機バインダより構成されるこ
とが望ましい。この場合は未焼成セラミツクシー
トに使用されるセラミツク誘電体の粒径よりも大
きい粒径のものを使用するが、未焼成セラミツク
シートの有機バインダの配合量よりも少い有機バ
インダの配合量にするか、未焼成セラミツク棒体
を加圧などして高密度にするか、あるいは未焼成
セラミツク棒体を予め有機バインダの分解温度よ
り低い温度で熱処理を加えるなどによつて実現さ
れる。また他の方法としては、焼成後のコンデン
サの電気特性に影響を与えない程度に、未焼成セ
ラミツクシートのセラミツク誘電体に対して、未
焼成セラミツク棒体のセラミツクの組成または組
成比をかえることもできる。例えば温度補償用の
材料は、酸化チタンを主成分として、温度特性を
かえるため、Mg，Zr，Ca，Alなどの成分が含ま
れているが、このような材料に酸化チタンを混合
したものをコンデンサ構成物として未焼成セラミ
ツク棒体を作ると、収縮率を小さくすることがで
きる。酸化チタン以外にも、アルミナ、シリカ、
マグネシアなどのコンデンサ粉末を混合すること
もできる。チタン酸バリウム等のチタン酸塩の材
料についても上と同様、他成分のセラミツクを混
合するか、成分比をかえるなどにより、未焼成セ
ラミツクシートの収縮率に対して、未焼成セラミ
ツク棒体の収縮率を小さくすることができる。す
なわち、未焼成セラミツクシートのセラミツクよ
りも、同一条件の焼成では焼結が若干遅れるよう
なセラミツクを未焼成セラミツク棒体に使用す
る。
未焼成セラミツク棒体の作成は、上述したもの
から選ばれたセラミツク粉末ならびに有機バイン
ダをロール機、らいかい機などで混練をし、この
混練物を加熱加圧などによりノから棒状に押出し
をすることにより得られる。
未焼成セラミツクシートの収縮率S1と未焼成セ
ラミツク棒体の収縮率S2の差S1−S2は、これが大
きくなれば、焼成においてシートの巻き締め効果
が大きく、高密度の焼成品が得られるが、一方で
は軸方向において段差が生じたり、クラツクが生
ずる。また、未焼成セラミツク棒体の外径R2と
未焼成セラミツク棒体上に未焼成セラミツクシー
トを巻き回わした円柱体の外径R1との比R2／R1
については、これが大きくなれば（棒体が太）巻
き締め効果が大きくなるが、この値が小さくなれ
ば（棒体が細い）十分な巻き締め効果が得られな
い。本発明者らは種々研究の結果R2／R1が0.2か
ら0.9の範囲内において、S1−S2の値が15％から
２％の範囲内であれば、上に述べたようなことは
起こらず、巻き締め効果のよい、電気的、機械的
強度のすぐれたコンデンサを得ることを見い出し
た。S1−S2が15％以上になると焼成後軸方向の段
差、クラツクなどが生じやすく、２％以下では十
分な巻き締めがおこなわれない。またR2／R1が
0.2以下であれば、十分な巻き締め効果が得られ
ず、0.9以上では、全容積に占めるシート状容量
体の割合が少なくなり、小形大容量のコンデンサ
を期待することはできない。S1−S2とR2／R1の
関係で最適な範囲としてはR2／R1が小さい領域
ではS1−S2を大きくし、R2／R1が大きい領域で
はS1−S2を小さくすることが望ましい。
＜実施例＞
温度補償用の酸化チタンの誘電体粉末（ε＝
40、平均粒径１μ）85wt％、ブチラール樹脂
7.5wt％、フタル酸ジブチル（DBP）7.5wt％、溶
剤としてイソプロピルアルコールをボールミルで
混合したスリツプを逆回転塗布機（リバースロー
ルコータ）を35μの未焼成セラミツクシートを作
成する。次いで先に述べた方法によりパラジウム
ペーストを印刷した２枚の未焼成セラミツクシー
トをポリエステルフイルムベース上に重ね合わせ
シート状容量体とする。
未焼成セラミツク棒体に使用するセラミツク粉
末として
(1) 未焼成セラミツクシートと同一の誘電体粉
末。
(2) 未焼成セラミツクシートと同一の誘電体粉末
を1100℃で仮焼し、粉砕したもの（平均粒径２
μ）。
(3) 未焼成セラミツクシートと同一の誘電体粉末
に酸化チタン粉末（ルチル）を１：１の重量比で
混合したもの。
(4) 上と同様の粉末を重量比で１：４で混合した
もの。
未焼成セラミツク棒体の構成物の配合量として
The present invention relates to a method for manufacturing wound ceramic capacitors having extremely large area electrodes within a compact, integral dielectric. Recently, as electronic devices have become more complex, there has been a strong trend toward smaller and higher density electronic circuits, and capacitors are required to be extremely small and large in capacity due to the limits of allowable volume. In order to obtain large capacitance, efforts have been made to develop materials with high dielectric constants and techniques to safely create thin films. In particular, much research has been conducted into the use of barium titanate, titanium oxide, and similar ceramic materials as dielectric materials for capacitors, as they have a high dielectric constant that cannot be obtained with other materials and are highly heat resistant. It's here. Furthermore, as a method for forming dielectric layers, a technique has been developed in which thin ceramic dielectric layers sandwiched between electrodes are laminated in multiple layers. A capacitor that takes advantage of such excellent characteristics of ceramics and a method for manufacturing the same are disclosed in US Pat. No. 3,004,197. This method creates a small, high-capacity cylindrical capacitor that has an electrode area several times larger than the capacitor's external shape, and has a continuous dielectric and an electrode that are in close contact with each other, making it mechanically strong and easy to handle, and a method for manufacturing the same. This is what we provide. Specifically, a slip made by mixing finely ground ceramic dielectric powder with approximately 10 to 20% wt of plastic along with a plasticizer is applied onto a support substrate and dried to form a shape-retaining and flexible unfired ceramic sheet. After making and cutting to appropriate dimensions,
A noble metal paste such as platinum or palladium is applied, then wound around a thin unfired ceramic rod to form a spiral and fired at a suitable temperature in the range of 1148°C to 1426°C to remove organic matter in the sheet. At the same time, the dielectric material and electrode are hardened together by the growth of ceramic microcrystals.
Next, silver electrodes are baked on both end faces to form terminals, and lead wires are soldered to the terminals to form a cylindrical capacitor. However, in ceramic capacitors obtained by winding and laminating unfired ceramic sheets and firing them, depending on the state of the winding and lamination, the dielectric material may not be uniformly integrated even after firing and may be partially formed. In some cases, substances that cause delamination between layers may appear. This layer peeling phenomenon occurs because the ceramic particles in the unfired ceramic sheet were not in sufficient contact with each other between the layers before firing, but if all the ceramic particles were in contact between the layers. To achieve this, it is necessary to apply pressure between the sheets in some way. In wound ceramic capacitors, it is not easy to apply pressure between layers, especially in unfired ceramic sheets with low tensile strength. After winding the ceramic sheet, the core of the unfired ceramic rod is rotated several times to tighten the winding and press the layers together. However, due to the mechanical strength limitations of unfired ceramic sheets and unfired ceramic rods,
In such a method, it is not easy to perform sufficient winding, and there is a strong risk that the above-mentioned layer peeling will occur. As a result, there are problems such as a decrease in the moisture absorption characteristics and mechanical strength of the capacitor, and furthermore, damage to the dielectric layer during high temperature processing such as soldering. SUMMARY OF THE INVENTION An object of the present invention is to eliminate these drawbacks and provide a highly reliable method for manufacturing a small, large-capacity wound ceramic capacitor. To achieve this objective, a sheet-like capacitor consisting of a flexible unfired ceramic dielectric sheet printed with a metal electrode paste was fabricated using a green ceramic dielectric material having a shrinkage rate smaller than that during firing of the sheet. A rolled ceramic capacitor is made by winding it around a rod to form a cylindrical capacitor, firing it under normal ceramic firing conditions, and attaching an external electrode to the end face and a lead wire to the external electrode. It's something you get. In the capacitor obtained by the present invention as described above, the laminations between the green ceramic sheets, between the green ceramic sheets and the electrodes, and between the green ceramic sheets and the green ceramic rods are extremely tight and integrated. A high-density ceramic sintered body is obtained, and no layer peeling occurs. As a result,
It is possible to obtain a small-sized, large-capacity ceramic capacitor that has excellent moisture resistance, mechanical strength, and soldering heat resistance. The reason for this effect of the present invention is that the shrinkage rate of the wound unfired ceramic sheet during firing is greater than that of the unfired ceramic rod serving as the shaft core. That is, during firing, a force similar to applying mechanical pressure is generated on the wound sheet, and this appears as a tightening effect. A method of winding and tightening that takes advantage of the difference in firing shrinkage rate is extremely useful industrially for capacitors of this type in which unfired ceramic sheets with low mechanical strength are wound and fired.
In other words, not only is the tightening operation and pressurizing operation omitted, but the pressure that is naturally generated during firing is uniform and suitable for the rolled shape, which cannot be obtained with external force. It is possible to obtain high-quality fired products that could not be obtained otherwise. Next, one embodiment of the present invention will be described in detail using the drawings. Green ceramic dielectric sheets are made by known methods. Ceramic dielectric materials include, for example, titanium oxide, which has a known material composition.
Alternatively, a fine powder of barium titanate, an organic binder such as polyvinyl butyral resin, and a plasticizer such as dibutyl phthalate are mixed uniformly with a suitable solvent in a pole mill, etc. to make a slip, which is coated with a knife coater, pipe coater, or reverse roll coater. Alternatively, as shown in FIG. 1, a film is formed on a film base 1 whose surface has been subjected to an appropriate release treatment by a method such as screen printing, and dried to form a green sheet 2 of a predetermined thickness. get. Next, strip-shaped electrodes 3 and 4 are printed on these unfired ceramic sheets 2 using a plate having a plurality of strip-shaped patterns using a noble metal conductive paste such as palladium, platinum, or platinum-palladium. Unfired ceramic sheets 5 and 6 provided with two types of electrodes as shown in FIGS. 2 and 3 are prepared. The length of this rectangular electrode in the longitudinal direction is the entire length of the electrode wound around one capacitor, and is the shorter length. Next, these two types of unfired ceramic sheets are overlapped at a position such that the center line 7 of the rectangular electrode 3 of one sheet and the center line 8 of the rectangular electrode 4 of the other sheet are slightly shifted from each other. This sheet-like capacitor 9 is bonded to form a sheet-like capacitor 9. Further, this sheet-like capacitor 9 is placed on a flat table, and an unfired ceramic rod 10 (to be described later) is placed at right angles to the longitudinal direction of the rectangular electrode 4, and a capacitor is attached using an appropriate adhesive. Glue it to the edge 11 of the body 9. Figure 4 shows these relationships. Next, the unfired ceramic rod 10 is pressed down with a flat plate 12 and rolled in the longitudinal direction of the electrode, rolled up while peeling off the capacitor 9 from the film base 1, and the final end is fixed with an appropriate adhesive to form a rod-shaped rod. A rolled product 13 is obtained. Next, it is cut at a position on the dotted line 14 as shown in FIG. 6, and fired under optimum firing conditions for an unfired ceramic sheet to obtain a capacitor body 15 shown in FIG. Further, as shown in FIG. 8, silver-palladium is baked on both end surfaces 16, 17 of this element body 15 to form external electrodes 18, 19, or as shown in FIG. 20 and 21 are attached with solder etc. to make a ceramic capacitor. The shrinkage rate of the green ceramic rod in the present invention during firing must be smaller than the shrinkage rate of the green ceramic sheet when fired under the optimum firing conditions for firing the green ceramic sheet. The shrinkage rate during firing of an unfired ceramic rod depends on the physical and chemical properties of the ceramic powder, the characteristics of the organic binder, the blending amount of these constituent materials, and the green density under certain firing conditions. will be determined. Specifically, it is desirable that the ceramic sheet be made of ceramic having the same composition as the unfired ceramic sheet and an organic binder. In this case, use a ceramic dielectric material with a particle size larger than that of the ceramic dielectric used in the unfired ceramic sheet, but the amount of organic binder mixed is smaller than that of the unfired ceramic sheet. Alternatively, this can be realized by pressurizing the unfired ceramic rod to make it denser, or by previously heat treating the unfired ceramic rod at a temperature lower than the decomposition temperature of the organic binder. Another method is to change the composition or composition ratio of the ceramic in the green ceramic rod relative to the ceramic dielectric in the green ceramic sheet to the extent that the electrical characteristics of the capacitor after firing are not affected. can. For example, materials for temperature compensation have titanium oxide as the main component and also contain components such as Mg, Zr, Ca, and Al to change the temperature characteristics. By making green ceramic rods as capacitor components, shrinkage can be reduced. In addition to titanium oxide, alumina, silica,
Capacitor powders such as magnesia can also be mixed. Similarly to the above, for titanate materials such as barium titanate, by mixing other ceramic components or changing the component ratio, the shrinkage of the unfired ceramic rod can be reduced relative to the shrinkage rate of the unfired ceramic sheet. The rate can be reduced. That is, the green ceramic rod is made of a ceramic that sinters a little more slowly than the ceramic of the green ceramic sheet when fired under the same conditions. To create an unfired ceramic rod, ceramic powder selected from those mentioned above and an organic binder are kneaded using a roll machine, a sieve machine, etc., and this kneaded material is extruded into a rod shape by heating and pressurizing. It can be obtained by The difference S 1 - S 2 between the shrinkage rate S 1 of the green ceramic sheet and the shrinkage rate S 2 of the green ceramic rod is the larger the difference, S 1 −S 2 , the greater the effect of tightening the sheet during firing, and the higher the density of the fired product. However, on the other hand, steps and cracks occur in the axial direction. Also, the ratio R 2 /R 1 of the outer diameter R 2 of the green ceramic rod and the outer diameter R 1 of the cylindrical body obtained by winding the green ceramic sheet around the green ceramic rod.
As for , if this value is large (the rod is thick), the tightening effect will be large, but if this value is small (the rod is thin), a sufficient tightening effect will not be obtained. As a result of various studies, the present inventors have found that if R 2 /R 1 is within the range of 0.2 to 0.9 and the value of S 1 −S 2 is within the range of 15% to 2%, the above-mentioned effect can be achieved. It has been found that a capacitor with good winding effect and excellent electrical and mechanical strength can be obtained. If S 1 -S 2 is more than 15%, steps and cracks in the axial direction are likely to occur after firing, and if it is less than 2%, sufficient winding cannot be achieved. Also, R 2 / R 1
If it is less than 0.2, a sufficient winding effect cannot be obtained, and if it is more than 0.9, the proportion of the sheet-like capacitor in the total volume will be small, and a small, large-capacity capacitor cannot be expected. The optimal range for the relationship between S 1 − S 2 and R 2 /R 1 is to increase S 1 −S 2 in the region where R 2 /R 1 is small, and to increase S 1 −S 2 in the region where R 2 /R 1 is large. It is desirable to reduce 2 . <Example> Titanium oxide dielectric powder for temperature compensation (ε=
40, average particle size 1μ) 85wt%, butyral resin
7.5wt% dibutyl phthalate (DBP) and isopropyl alcohol as a solvent are mixed in a ball mill and a reverse roll coater is used to create a 35μ unfired ceramic sheet. Next, two unfired ceramic sheets printed with palladium paste by the method described above are superimposed on a polyester film base to form a sheet-like capacitor. Ceramic powder used for the unfired ceramic rod: (1) The same dielectric powder as the unfired ceramic sheet. (2) The same dielectric powder as the unfired ceramic sheet was calcined at 1100℃ and crushed (average particle size 2
μ). (3) Titanium oxide powder (rutile) is mixed with the same dielectric powder as the unfired ceramic sheet at a weight ratio of 1:1. (4) A mixture of the same powders as above in a weight ratio of 1:4. As the compounding amount of the components of the unfired ceramic rod
【表】
以上の夫々の配合品に若干の溶剤を加えて２段ロ
ールで混練し、加熱加圧によりノから押出し未焼
成セラミツク棒体を作成した。未焼成セラミツク
シートならびに未焼成セラミツク棒体の収縮率
は、未焼成セラミツクシートの焼成条件、空気中
で200℃／Hrの昇降温速度400℃と1200℃で2Hrs
保持で焼成した後焼成前からの長さ変化で測定し
た。なお、未焼成セラミツクシートの収縮率は未
焼成セラミツクシートを単独で巻回し棒状にした
ものを上の条件で焼成したもので測定した。
次いで、前述した方法により、シート状容量体
を夫々の未焼成セラミツク棒体に巻き回して外径
３mm、長さ５mmの円柱形容量体とし、これを先述
した焼成条件で焼成した後、両端部に銀電極を焼
付けてコンデンサとした。R2／R1の可変は、未
焼成セラミツク棒体の径ならびに未焼成セラミツ
クシートの巻き数をかえることにより実現した。
（R2／R1＝０は芯のないもの）
第１表に夫々の未焼成セラミツク棒体を使用し
た巻き回し品の焼成後における薄片化ならびにク
ラツクなど外観の観察結果を示す。[Table] A small amount of solvent was added to each of the above blended products, kneaded with two-stage rolls, and extruded by heating and pressure to produce unfired ceramic rods. The shrinkage rate of the unfired ceramic sheet and the unfired ceramic rod is determined by the firing conditions of the unfired ceramic sheet: 200°C/Hr heating/cooling rate in air of 400°C and 2Hrs at 1200°C.
After holding and firing, the change in length from before firing was measured. The shrinkage rate of the unfired ceramic sheet was measured by winding the unfired ceramic sheet alone into a rod shape and firing it under the above conditions. Next, by the method described above, the sheet-shaped capacitor is wound around each unfired ceramic rod to form a cylindrical capacitor with an outer diameter of 3 mm and a length of 5 mm. After firing this under the firing conditions described above, both ends are A capacitor was made by baking a silver electrode onto the capacitor. Variation of R 2 /R 1 was achieved by changing the diameter of the green ceramic rod and the number of turns of the green ceramic sheet.
(R 2 /R 1 = 0 means no core) Table 1 shows the observation results of the external appearance such as flaking and cracks after firing of the rolled products using each unfired ceramic rod.
【表】
なおＧの巻き芯はＡの未焼成セラミツク棒体を予
め上に述べた焼成条件で焼成したものを使用し
た。表中で巻き締め効果のすぐれた、すなわち薄
片化かかつクラツク、段差などのないものを〇
印、薄片化、クラツク、段差などの生じたものを
×印で示した。〇印のコンデンサの電気的、機械
的な特性は、40℃における相対湿度94％ならびに
85℃においてDC150Vを印加して1000時間、260
℃のハンダ槽中に10秒浸漬などの試験後において
も、容量、誘電体損失などは損こなわれず、また
外観的な損傷も認められない。また、未焼成セラ
ミツク棒体Ｅ，Ｆを使用したものは、温度特性、
誘電体損失、その他の特性は他のものに比して何
ら変ることはなかつた。
S1−S2の０のものあるいは小さいものは薄片化
が生じ、また、差が大きすぎるものはクラツクが
生じているが、このようなコンデンサは、機械的
強度が弱いのみならず、40℃における相対湿度94
％で直流電圧を印加すると絶縁不良を起したり、
短絡するものが多数発生する。
以上の実施例においては温度補償用の酸化チタ
ンの材料を用いたが、チタン酸バリウムの高誘電
率材料を用いたグリーンシートについても、同様
の効果のあることを確認した。これら以外のセラ
ミツク誘電体、たとえば、1000℃以下で焼成可能
なものについても本発明の効果を有する。
未焼成セラミツクシート、未焼成セラミツク棒
体、巻き込み方法などは、実施例に述べた以外の
方法であつてもこれに拘束されることなく本発明
の効果を有する。例えば、一枚の未焼成セラミツ
クシートの上に一対の電極を形成したものを巻回
することもできる。また、未焼成セラミツク棒体
は、押出し品ではなく、未焼成セラミツクシート
を巻回して棒状にしたものであつてもよい。また
シート状容量体は２枚のシートを貼り合わせる方
法でなくても、フイルムベース上にスクリーン印
刷手法などによつて、誘電体層、電極層を順次形
成する方法であつてもよい。
巻き芯の形状は、断面が面形であることに拘束
されず、だ円形、扁平形であつても本発明の効果
は有するものである。
以上述べたように本発明は未焼成セラミツク誘
電体のシートよりなるシート状容量体を、該シー
トの焼成収縮率よりも小さい収縮率を有する未焼
成セラミツク棒体を巻き軸として巻回積層され、
これを焼成するセラミツクコンデンサの製造方法
であり、このコンデンサは、焼成時において未焼
成セラミツクシートと未焼成セラミツク棒体の収
縮率の差による巻き締め圧力により、きわめて層
間の稠密で一体化された、薄片化、クラツクなど
のないものであり、電気的、機械的特性のすぐれ
かつ小形、大容量の実現しうるものである。[Table] The winding core of G was obtained by firing the unfired ceramic rod of A under the firing conditions described above. In the table, those with excellent winding effect, that is, those with flaking and no cracks or steps, are marked with ○, and those with flaking, cracks, steps, etc. are marked with x. The electrical and mechanical properties of capacitors marked with
1000 hours with DC150V applied at 85℃, 260
Even after tests such as immersion in a solder bath at ℃ for 10 seconds, the capacitance and dielectric loss remain intact, and no external damage is observed. In addition, those using unfired ceramic rods E and F have temperature characteristics,
The dielectric loss and other characteristics did not change at all compared to the others. Capacitors with S 1 - S 2 of 0 or small have flaking, and capacitors with too large a difference have cracks, but such capacitors not only have weak mechanical strength but also Relative humidity at 94
If DC voltage is applied at %, insulation failure may occur.
Many short circuits occur. Although titanium oxide material for temperature compensation was used in the above embodiments, it was confirmed that a green sheet made of barium titanate, a high dielectric constant material, had similar effects. Ceramic dielectrics other than these, for example those that can be fired at 1000° C. or lower, also have the effects of the present invention. Even if the unfired ceramic sheet, the unfired ceramic rod, the winding method, etc. are used in a manner other than those described in the embodiments, the effects of the present invention are still achieved without being restricted thereto. For example, a pair of electrodes formed on a single unfired ceramic sheet may be wound. Moreover, the unfired ceramic rod may not be an extruded product but may be a rod-shaped product obtained by winding an unfired ceramic sheet. Further, the sheet-like capacitor does not have to be formed by bonding two sheets together, but may be formed by sequentially forming a dielectric layer and an electrode layer on a film base by screen printing or the like. The shape of the winding core is not limited to a planar cross section, and the effects of the present invention can be obtained even if the core is oval or flat. As described above, the present invention comprises a sheet-shaped capacitor made of a sheet of unfired ceramic dielectric material, which is wound and laminated around an unfired ceramic rod having a shrinkage ratio smaller than that of the sheet when fired, and
This is a method of manufacturing a ceramic capacitor in which the ceramic capacitor is produced by firing the unfired ceramic sheet, and this capacitor is produced by the tightening pressure caused by the difference in shrinkage rate between the unfired ceramic sheet and the unfired ceramic rod during firing, so that the layers are extremely dense and integrated. It does not cause flaking or cracking, has excellent electrical and mechanical properties, and can be made compact and large in capacity.
図面は本発明にかかるセラミツクコンデンサの
製造方法の工程を説明するためのものであり、第
１図から第５図までは斜視図、第６図は断面図、
第７図〜第９図は斜視図である。
１……フイルムベース、２，３……未焼成セラ
ミツク誘電体シート、４，５……電極ペースト、
６……電極中心線、７……電極間中心線、８……
未焼成セラミツク棒体、９……平面板、１０……
棒状巻きとり品、１１……円柱状容量体、１２…
…セラミツクチツプコンデンサ、１３……セラミ
ツクリード付コンデンサ、１４，１５……内部電
極、１６……誘電体、１７……未焼成セラミツク
棒体、１８，１９……外部電極、２０，２１……
リード線、２２……未焼成セラミツクシート終
端。
The drawings are for explaining the steps of the method for manufacturing a ceramic capacitor according to the present invention, and FIGS. 1 to 5 are perspective views, FIG. 6 is a sectional view, and FIG.
7 to 9 are perspective views. 1... Film base, 2, 3... Unfired ceramic dielectric sheet, 4, 5... Electrode paste,
6... Electrode center line, 7... Center line between electrodes, 8...
Unfired ceramic rod, 9... flat plate, 10...
Rod-shaped rolled product, 11...Cylindrical capacitor, 12...
... Ceramic chip capacitor, 13 ... Capacitor with ceramic lead, 14, 15 ... Internal electrode, 16 ... Dielectric, 17 ... Unfired ceramic rod, 18, 19 ... External electrode, 20, 21 ...
Lead wire, 22... end of unfired ceramic sheet.
Claims (1)
成セラミツク誘電体シートよりなるシート状容量
体を、該シートの焼成における収縮率より小さい
収縮率を有するセラミツク誘電体よりなる未焼成
セラミツク誘電体棒体上に巻き回し、円柱状容量
体を得て、これを焼成することを特徴とした巻回
形セラミツクコンデンサの製造方法。 ２ 未焼成セラミツク誘電体棒体の直径をR2、
円柱状容量体の直径をR1、未焼成セラミツク誘
電体シートの焼成における収縮率をS1、前記棒体
の焼成における収縮率をS2としたとき〔R2／
R1〕が0.2から0.9の範囲内で〔S1−S2〕が２％から
15％である特許請求の範囲第１項記載の巻回形セ
ラミツクコンデンサの製造方法。 ３ セラミツク誘電体が酸化チタンまたはチタン
酸塩である特許請求の範囲第１項記載の巻回形セ
ラミツクコンデンサの製造方法。 ４ 金属電極が白金、パラジウムおよび白金、パ
ラジウムで構成された特許請求の範囲第１項記載
の巻回形セラミツクコンデンサの製造方法。 ５ 未焼成セラミツク誘電体棒体が未焼成セラミ
ツク誘電体シートと同一組成のセラミツク誘電体
ならびに有機バインダより構成された特許請求の
範囲第１項記載の巻回形セラミツクコンデンサの
製造方法。 ６ 未焼成セラミツク誘電体棒体が、未焼成セラ
ミツク誘電体シートの有機バインダ含有量よりも
少い有機バインダ含有量である特許請求の範囲第
１項記載の巻回形セラミツクコンデンサの製造方
法。 ７ 未焼成セラミツク誘電体棒体が、未焼成セラ
ミツク誘電体シートのセラミツク誘電体の粒径よ
りも大きい粒径のセラミツク誘電体より構成され
た特許請求の範囲第１項記載の巻回形セラミツク
コンデンサの製造方法。 ８ 未焼成セラミツク誘電体棒体を、有機バイン
ダの分解温度以下で熱処理する特許請求の範囲第
１項記載の巻回形セラミツクコンデンサの製造方
法。[Scope of Claims] 1. A sheet-like capacitor made of a flexible unfired ceramic dielectric sheet printed with a metal electrode paste is made of a ceramic dielectric material having a shrinkage rate smaller than the shrinkage rate of the sheet during firing. A method for manufacturing a wound ceramic capacitor, which comprises winding an unfired ceramic dielectric rod onto a rod to obtain a cylindrical capacitor, which is then fired. 2 The diameter of the unfired ceramic dielectric rod is R 2 ,
When the diameter of the cylindrical capacitor is R 1 , the shrinkage rate during firing of the unfired ceramic dielectric sheet is S 1 , and the shrinkage rate during firing of the rod is S 2 [R 2 /
R 1 ] is within the range of 0.2 to 0.9 and [S 1 −S 2 ] is from 2%
15%. A method for manufacturing a wound ceramic capacitor according to claim 1. 3. The method for manufacturing a wound ceramic capacitor according to claim 1, wherein the ceramic dielectric is titanium oxide or titanate. 4. The method for manufacturing a wound ceramic capacitor according to claim 1, wherein the metal electrode is composed of platinum, palladium, and platinum, palladium. 5. The method of manufacturing a wound ceramic capacitor according to claim 1, wherein the green ceramic dielectric rod is composed of a ceramic dielectric having the same composition as the green ceramic dielectric sheet and an organic binder. 6. The method of manufacturing a wound ceramic capacitor according to claim 1, wherein the green ceramic dielectric rod has an organic binder content lower than that of the green ceramic dielectric sheet. 7. The wound ceramic capacitor according to claim 1, wherein the green ceramic dielectric rod is made of a ceramic dielectric having a particle size larger than the particle size of the ceramic dielectric of the green ceramic dielectric sheet. manufacturing method. 8. The method of manufacturing a wound ceramic capacitor according to claim 1, wherein the unfired ceramic dielectric rod is heat-treated at a temperature below the decomposition temperature of the organic binder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15979678A JPS5585016A (en) | 1978-12-21 | 1978-12-21 | Method of fabricating spiral ceramic capacitor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15979678A JPS5585016A (en) | 1978-12-21 | 1978-12-21 | Method of fabricating spiral ceramic capacitor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5585016A JPS5585016A (en) | 1980-06-26 |
| JPS6129529B2 true JPS6129529B2 (en) | 1986-07-07 |
Family
ID=15701442
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15979678A Granted JPS5585016A (en) | 1978-12-21 | 1978-12-21 | Method of fabricating spiral ceramic capacitor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5585016A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02265311A (en) * | 1989-04-05 | 1990-10-30 | Matsushita Electric Ind Co Ltd | Crystal resonator |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58222515A (en) * | 1982-06-18 | 1983-12-24 | Matsushita Electric Ind Co Ltd | Manufacture of coil parts |
| JPH02161710A (en) * | 1989-08-05 | 1990-06-21 | Matsushita Electric Ind Co Ltd | Manufacture of coil parts |
| TW428184B (en) * | 1998-02-19 | 2001-04-01 | Teijin Ltd | Method and apparatus for producing laminated type electronic component |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5230704A (en) * | 1975-09-04 | 1977-03-08 | Koichi Ogiso | Process and apparatus for treating molten metal by convection |
-
1978
- 1978-12-21 JP JP15979678A patent/JPS5585016A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5230704A (en) * | 1975-09-04 | 1977-03-08 | Koichi Ogiso | Process and apparatus for treating molten metal by convection |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02265311A (en) * | 1989-04-05 | 1990-10-30 | Matsushita Electric Ind Co Ltd | Crystal resonator |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5585016A (en) | 1980-06-26 |
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