JPH0353606A - Manufacture of laminated lr filter - Google Patents
Manufacture of laminated lr filterInfo
- Publication number
- JPH0353606A JPH0353606A JP1189988A JP18998889A JPH0353606A JP H0353606 A JPH0353606 A JP H0353606A JP 1189988 A JP1189988 A JP 1189988A JP 18998889 A JP18998889 A JP 18998889A JP H0353606 A JPH0353606 A JP H0353606A
- Authority
- JP
- Japan
- Prior art keywords
- ferrite
- filter
- external
- electrode
- raw 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.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 15
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 54
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000001301 oxygen Substances 0.000 claims abstract description 10
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 10
- 230000007935 neutral effect Effects 0.000 claims abstract description 6
- 239000010949 copper Substances 0.000 claims description 16
- 229910052802 copper Inorganic materials 0.000 claims description 15
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 14
- 229910003962 NiZn Inorganic materials 0.000 claims description 10
- 229910052709 silver Inorganic materials 0.000 claims description 10
- 239000004332 silver Substances 0.000 claims description 10
- 239000007789 gas Substances 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 9
- SWELZOZIOHGSPA-UHFFFAOYSA-N palladium silver Chemical compound [Pd].[Ag] SWELZOZIOHGSPA-UHFFFAOYSA-N 0.000 claims description 9
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 7
- 238000010304 firing Methods 0.000 claims description 7
- 238000010030 laminating Methods 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 229910052718 tin Inorganic materials 0.000 claims description 2
- 239000004065 semiconductor Substances 0.000 abstract description 4
- 239000002994 raw material Substances 0.000 abstract 5
- 230000008030 elimination Effects 0.000 abstract 1
- 238000003379 elimination reaction Methods 0.000 abstract 1
- 238000007639 printing Methods 0.000 description 7
- 238000000605 extraction Methods 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 238000005476 soldering Methods 0.000 description 4
- 239000007772 electrode material Substances 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 101100313164 Caenorhabditis elegans sea-1 gene Proteins 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Manufacturing Cores, Coils, And Magnets (AREA)
- Coils Or Transformers For Communication (AREA)
- Filters And Equalizers (AREA)
- Apparatuses And Processes For Manufacturing Resistors (AREA)
- Soft Magnetic Materials (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野コ
本発明は、ＮｉＺｎ系フェライトのグリーンシー１・を
積層して形成された積層型ＬＲフィルタの製造方法に関
する．
［背景技術］
現在、ＥＭＩ（電磁干渉）除去用インダクタとしては、
巻線タイプのチップコイルや積層型のチップコイルが多
く使用されている。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a multilayer LR filter formed by stacking NiZn-based ferrite Green Sea 1. [Background technology] Currently, inductors for eliminating EMI (electromagnetic interference) include:
Wire-wound type chip coils and laminated type chip coils are often used.
このうち積層型のチップコイル５１は、第６図及び第７
図に示すように、複数枚のフェライトのグリーンシート
５２．５３及び５４を積層して形成したフェライト素体
５５の内部に、コイル状またはストレート状等の内部電
極５６を形成し、フェライト素体５５の外面に内部電極
５６と導通した外部電極５７を形成したものである。第
６図は、このような積層型チップコイル５１の外観斜視
図であり、第７図はその一製造過程を表している．
第７図を参照しながら、この積層型チップコイル５ｌの
製造方法を詳しく説明する．フェライト素体５５は、印
刷シ一ト５８の上下両面に複数枚のグリーンシート５２
．５４ （ダミーシ一ト）を積層することによって形成
されている．この印刷シート５８は、グリーンシート５
３の表裏両面に銀または銀パラジウムの導電ペーストを
印刷することにより、それぞれ０．７５ターンのコイル
部５９と外部引き出し電極６０からなる内部電極５６を
形戒したものであり、グリーンシート５３に穿孔された
スルーホール６１を通して表裏のコイル部５９の先端同
士を導通させ、外部引き出し電極６０間に１．５ターン
のコイル部５９を形成してある．しかして、上記のよう
な印刷シート５８の上下両面に何も印刷されていない複
数枚のグリーンシー｝５２．５４を積層して平面加圧す
ることにより一体化し、積層されたグリーンシート５２
，５３．５４によってフェライト素体５５が形成される
．この後、生のフェライト素体５５は空気中において適
当な温度で焼成され、一体焼成品のフェライト素体５５
が製作される。さらに、バレル研磨もしくは平面研磨に
よってフェライト素体５５の両端を研削し、内部の外部
引き出し電ｆ！６０を露出させた後、第６図に示すよう
にフェライト素体５５の両端外面に銀または銀パラジウ
ムの導電ペーストを塗布し、空気中で焼成することによ
り外部引き出し電極６０と導通した外部電極５７を形成
している．このようにして製造された積層型チップコイ
ル５１においては、空気中で焼成されたフェライト素体
５５は高抵抗の絶縁体であった．
［発明が解決しようとする課題］
上記のようにして製造された積層型チップコイルをデシ
タル回路等のＥＭＩ除去フィルタ用として使用した場合
、このチップコイルは高周波域で必ず共振点ｆ。を持ち
、それ以上の周波数ではインダクタの働きをせず、むし
ろキャパシタとして働き、周波数−インピーダンス特性
は第８図に実線で示す曲線イのようになる．この共振点
ｆ。においては、インダクタとキャパシタの並列共振の
ため、使用される回路によっては異常発振が発生し、か
えって有害なノイズを発生させる．このような場合には
、インダクタに並列に抵抗体等のインピーダンス素子を
接続して用いられる．このようにインダクタに並列に抵
抗体等のインピーダンス素子を接続して用いると、周波
数−インピーダンス特性は第８図に破線で示す曲線ロの
ように滑らかになり、共振点がなくなる．したがって、
滑らかなノイズ除去特性を得ることができ、使用回路を
制限されることなく広い用途に利用できるようになる．
このように積層型チップコイルを用いた場合には、使用
回路によっては異常発振が発生し、有害なノイズを生じ
ることがあるので、この対策としてインダクタに並列に
抵抗体等のインピーダンス素子を接続する必要があるが
、従来の積層型チップコイルには内部に抵抗体を内蔵し
たものはなかったので、このような場合には抵抗体等の
個別電気部品を外付けする必要があり、電子回路のコス
トが増大すると共に半田付け等の処理が必要となって面
倒が増し、また電子回路の小型化の妨げにもなっていた
。Among these, the laminated type chip coil 51 is shown in FIGS. 6 and 7.
As shown in the figure, a coil-shaped or straight-shaped internal electrode 56 is formed inside a ferrite element body 55 formed by laminating a plurality of ferrite green sheets 52, 53 and 54, and the ferrite element body 55 is An external electrode 57 electrically connected to an internal electrode 56 is formed on the external surface of the external electrode 57 . FIG. 6 is an external perspective view of such a laminated chip coil 51, and FIG. 7 shows one manufacturing process thereof. The manufacturing method of this laminated chip coil 5l will be explained in detail with reference to FIG. The ferrite element body 55 includes a plurality of green sheets 52 on both the upper and lower surfaces of the printing sheet 58.
．． It is formed by stacking 54 (dummy sheets). This printed sheet 58 is the green sheet 5
By printing conductive paste of silver or silver palladium on both the front and back sides of the green sheet 53, an internal electrode 56 consisting of a coil part 59 of 0.75 turns and an external lead electrode 60 is formed, and the green sheet 53 is perforated. The tips of the front and back coil portions 59 are electrically connected to each other through the through-holes 61, and a 1.5-turn coil portion 59 is formed between the external extraction electrodes 60. Thus, a plurality of green sheets 52 and 54 with nothing printed on both the upper and lower surfaces of the printing sheet 58 as described above are stacked and flatly pressed to integrate them, resulting in a stacked green sheet 52.
, 53 and 54 form a ferrite element body 55. Thereafter, the raw ferrite element body 55 is fired in air at an appropriate temperature, and the ferrite element body 55 is integrally fired.
is produced. Furthermore, both ends of the ferrite element body 55 are ground by barrel polishing or surface polishing, and the internal external extraction voltage f! After exposing the external electrode 60, as shown in FIG. 6, a conductive paste of silver or silver palladium is applied to the outer surface of both ends of the ferrite element body 55, and the external electrode 57 is electrically connected to the external extraction electrode 60 by baking in air. is formed. In the multilayer chip coil 51 manufactured in this manner, the ferrite element body 55 fired in air was a high-resistance insulator. [Problems to be Solved by the Invention] When the multilayer chip coil manufactured as described above is used as an EMI removal filter for a digital circuit, etc., the chip coil always has a resonance point f in the high frequency range. At frequencies higher than that, it does not act as an inductor, but rather acts as a capacitor, and the frequency-impedance characteristic is as shown by the solid line curve A in Figure 8. This resonance point f. Due to the parallel resonance of the inductor and capacitor, abnormal oscillation may occur depending on the circuit used, which may even generate harmful noise. In such cases, an impedance element such as a resistor is connected in parallel to the inductor. When an impedance element such as a resistor is connected in parallel to an inductor and used in this way, the frequency-impedance characteristic becomes smooth as shown by the broken line in FIG. 8, and there is no resonance point. therefore,
Smooth noise removal characteristics can be obtained, and the circuit used can be used for a wide range of purposes without being restricted. When using a laminated chip coil in this way, abnormal oscillation may occur depending on the circuit used, and harmful noise may be generated.As a countermeasure, an impedance element such as a resistor should be connected in parallel to the inductor. However, conventional multilayer chip coils do not have built-in resistors, so in such cases it is necessary to externally attach individual electrical components such as resistors, which makes it difficult for electronic circuits to function. This increases the cost, requires processes such as soldering, which increases the trouble, and also impedes miniaturization of electronic circuits.
しかして、本発明は叙上の従来例の欠点に鑑みてなされ
たものであり、その目的とするところは個別の電子部品
を外付けすることなく、滑らかなＥＭＩ除去特性を得る
ことのできる積層型ＬＲフィルタの製造方法を提供する
ことにある．［課題を解決するための手段コ
このため、本発明の積層型ＬＲフィルタの製造方法は、
ＮｉＺｎ系フェライｌ・のグリーンシートを積層するこ
とによって形成したフェライト素体の内部に銀、銀パラ
ジウム，銅等の導電ペーストを用いてインダクタンスと
して働く内部電極を形成すると共に、このフェライト素
体の外面に銀、銀パラジウム、銅等の導電ペーストを用
いて外部電極を形成した後、このフェライト素体をＨ２
， ＣＯガス等の還元雰囲気もしくはＮ２， Ａｒガス
等の中性雰囲気で酸素濃度０１％以下の中で焼成するこ
とにより、前記フェライト素体を低抵抗化することを特
徴としている。The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and its purpose is to provide a multilayer structure that can obtain smooth EMI removal characteristics without externally attaching individual electronic components. The purpose of this invention is to provide a method for manufacturing a type LR filter. [Means for Solving the Problems] Therefore, the method for manufacturing a multilayer LR filter of the present invention is as follows:
Inside a ferrite element body formed by laminating green sheets of NiZn-based ferrite, an internal electrode that acts as an inductance is formed using a conductive paste of silver, silver palladium, copper, etc., and the outer surface of this ferrite element body is After forming external electrodes using a conductive paste of silver, silver palladium, copper, etc., this ferrite element body was heated to H2
The ferrite element is characterized in that the resistance of the ferrite element body is reduced by firing in a reducing atmosphere such as , CO gas or a neutral atmosphere such as N2 or Ar gas at an oxygen concentration of 01% or less.
また、内部電極もしくは外部電極のうち少なくとも一方
を銅電極とするのが好ましい。Further, it is preferable that at least one of the internal electrodes and the external electrodes is a copper electrode.
さらに、外部電極の表面にはＮｉ， Ｓｎ等のメッキを
施しても良い。Furthermore, the surface of the external electrode may be plated with Ni, Sn, or the like.
［作用コ
本発明にあっては、焼成前のフェライト素体に導電ペー
ストにより内部電極および外部電極を形成した後、これ
をＨ２， ＣＯガス等の還元雰囲気もしくはＮ２， Ａ
ｒガス等の中性雰囲気で酸素濃度０．１％以下の中で焼
戒したところ、ＮｉＺｎ系フェライト中のＦｅ２０３
， ＣｕＯの中の酸素の一部が抜けてフェライト素体が
半導体化され、低抵抗化した。このため、インダクタン
スとして働く内部電極の両端間に低抵抗のフェライト層
（フェライト素体〉が並列に配置され、内部電極による
インダクタンスとフェライト素体による抵抗を並列接続
したのと同じ等価回路を構成することができた．
したがって、個別の抵抗体を外付けずることなく、従来
の積層型チップコイルに個別部品の抵抗体を外付けした
場合と同様な共振点のない周波数インピーダンス特性を
得ることができる。[Operation] In the present invention, after forming internal electrodes and external electrodes with a conductive paste on a ferrite element body before firing, it is placed in a reducing atmosphere such as H2, CO gas, or N2, A gas.
When burned in a neutral atmosphere such as r gas with an oxygen concentration of 0.1% or less, Fe203 in NiZn ferrite was
, Some of the oxygen in CuO was removed and the ferrite element became a semiconductor, resulting in lower resistance. For this reason, a low-resistance ferrite layer (ferrite element body) is placed in parallel between both ends of the internal electrode that acts as an inductance, forming an equivalent circuit similar to connecting the inductance of the internal electrode and the resistance of the ferrite element in parallel. Therefore, without having to externally attach individual resistors, it is possible to obtain frequency impedance characteristics without resonance points, similar to when externally attaching individual resistors to a conventional multilayer chip coil. .
また、低濃度酸素雰囲気中で内部電極及び外部電極を焼
或することにより、両電極の酸化を防止することができ
る．
［実施例コ
以下、本発明の実施例を添付図に基づいて詳述する．
フェライト素体４は、第１図に示すように、印刷シ一ト
７の上下両面にそれぞれ複数枚のＮｉＺｎ系フェライト
のグリーンシート１．３を積層し、平面加圧したもので
ある。印刷シ一ト７は、ＮｉＺｎ系フェライトのグリー
ンシート２の表面に銀、銀パラジウムもしくは銅等の内
部電極５を形成したものであり、第１図の図示例では、
グリーンシート２の一方表面において外部引き出し電極
８間にストレート状のインダクタ部９を設けてある。ま
た、印刷シ一ト７の上下のグリーンシート１．３は、ダ
ミーシ一トであって、電極等の設けられていないもので
みる．積層型ＬＲフィルタ１ｏは、上記のようにして積
層一体化した生のフェライト素体４を焼成して得た一体
焼成品の両端部外面に外部引き出し電極８と導通した銀
、銀パラジウムもしくは銅等の外部電極６を形成したも
のである．また、このＮｉＺｎ系フェライトがらなるフ
ェライト素体４は、半導体化させることによって低抵抗
化されており、この結果外部電極６間にはインダクタ部
９によって付与されるインダクタンスＬと低抵抗化され
たフェライト素体４によって付与された抵抗Ｒとが並列
に接続されており、この積層型ＬＲフィルタ１０の等価
回路は第３図のようになっている．
つぎに、上記積層型ＬＲフィルタ１０の製造方法を説明
する．まず、ＮｉＺｎ系フェライト粉末及び有機溶媒、
バインダー等を混練して泥しようにした後、押し出し法
、引き上げ法あるいはブレード法によりシート状に或形
し、複数枚のＮｉＺｎ系フェライトのグリーンシート１
，２及び３を得る．ついで、グリーンシー１・２の表面
に銀、銀バラジウムもしくは銅等の導電ペーストを印刷
して所定パターンの内部ｔ％５を形成し、印刷シ一ト７
を得る．印刷シ一ト７の表裏両面に適宜の枚数のグリー
ンシート１，３をダミーシ一トとして重ね、ダミーシ一
ト間に印刷シ一ト７を挟み込み、上下から平面加圧し、
各グリーンシート１，２及び３を密着させ、生のフェラ
イト素体４を成形する。この後、フェライト素体４の両
端に外部引き出し電極８を露出させ、この外部引き出し
電極８の露出部分と導通させるようにしてフェライト素
体４の両端部外面に銀、銀パラジウムもしくは銅等の導
電ペーストを塗布し、外部電極６を形成する．この後、
生のフェライト素体４及び導電ペーストによりて形成さ
れている内部電極５及び外部電極６が同時に焼成され、
一体焼戒品の積層型ＬＲフィルタ１０が製造される．本
発明の実施例にあっては、この焼或工程で、Ｈ２， Ｃ
Ｏガス等の還元雰囲気もしくはＮ２， Ａｒガス等の中
性雰囲気で酸素濃度Ｏ．１％以下の雰囲気中において、
適宜温度で焼成される。このような低酸素濃度雰囲気中
で内部電極５及び外部電ｆ！６を焼成すれば、焼成中に
おける両電８ｉ！５及び６の酸化を防止することができ
る。しかも、スビネル型フェライトを還元または中性雰
囲気などの酸素分圧の低い雰囲気中で熱処理すると、フ
ェライト組成中のＦｅ２０３ ， ＣｕＯの中の酸素原
子の一部が抜け出てＦｅ及びＣｕの原子価の一部がＦｅ
”→Ｆｅ” ， Ｃｕ”→Ｃｕ＋と変化する．この結果
、フェライト素体４が半導体化して低抵抗となり、空気
中で焼成した場合のＮｉＺｎ系フェライトの固有抵抗が
１０９Ωｃｍ以上であるのに対し、１０〜１０４Ωｃｍ
という小さな抵抗率が得られた。Furthermore, by burning the internal and external electrodes in a low concentration oxygen atmosphere, oxidation of both electrodes can be prevented. [Embodiments] Hereinafter, embodiments of the present invention will be described in detail based on the attached drawings. As shown in FIG. 1, the ferrite element body 4 is made by laminating a plurality of NiZn-based ferrite green sheets 1.3 on both the upper and lower surfaces of a printing sheet 7, and pressing them flatly. The printed sheet 7 has an internal electrode 5 made of silver, silver palladium, copper, etc. formed on the surface of the NiZn-based ferrite green sheet 2, and in the illustrated example in FIG.
A straight inductor portion 9 is provided between external lead-out electrodes 8 on one surface of the green sheet 2 . In addition, the green sheets 1.3 above and below the printing sheet 7 are dummy sheets and are not provided with electrodes or the like. The multilayer LR filter 1o is an integrally fired product obtained by firing the raw ferrite body 4 that is laminated and integrated as described above, and has silver, silver palladium, copper, etc. electrically connected to the external extraction electrode 8 on the outer surface of both ends of the integrally fired product. The external electrode 6 is formed. Further, the ferrite element body 4 made of NiZn-based ferrite has a low resistance by being made into a semiconductor, and as a result, the inductance L provided by the inductor part 9 and the low resistance ferrite are connected between the external electrodes 6. The resistor R provided by the element body 4 is connected in parallel, and the equivalent circuit of this multilayer LR filter 10 is as shown in FIG. Next, a method for manufacturing the multilayer LR filter 10 will be explained. First, NiZn-based ferrite powder and organic solvent,
After kneading a binder etc. to make a slurry, it is shaped into a sheet by an extrusion method, a pulling method or a blade method to form a plurality of NiZn ferrite green sheets 1.
, 2 and 3 are obtained. Next, a conductive paste such as silver, silver-valadium or copper is printed on the surfaces of the green sheets 1 and 2 to form an internal t%5 of a predetermined pattern.
obtain. An appropriate number of green sheets 1 and 3 are stacked on both sides of the printing sheet 7 as dummy sheets, the printing sheet 7 is sandwiched between the dummy sheets, and plane pressure is applied from above and below.
The green sheets 1, 2, and 3 are brought into close contact with each other to form a raw ferrite body 4. After that, external lead-out electrodes 8 are exposed at both ends of the ferrite element body 4, and a conductive material such as silver, silver palladium, or copper is applied to the outer surface of both ends of the ferrite element body 4 so as to be electrically connected to the exposed portions of the external lead-out electrodes 8. Apply paste to form external electrodes 6. After this,
The raw ferrite element body 4 and the internal electrodes 5 and external electrodes 6 formed from the conductive paste are fired at the same time,
A monolithically fired multilayer LR filter 10 is manufactured. In the embodiment of the present invention, in this baking step, H2, C
The oxygen concentration is O. in a reducing atmosphere such as O gas or a neutral atmosphere such as N2 or Ar gas. In an atmosphere of 1% or less,
It is fired at an appropriate temperature. In such a low oxygen concentration atmosphere, the internal electrode 5 and the external electrode f! If you fire 6, it will be 8i during firing! Oxidation of 5 and 6 can be prevented. Moreover, when Subinel type ferrite is heat-treated in an atmosphere with low oxygen partial pressure such as a reducing or neutral atmosphere, some of the oxygen atoms in Fe203 and CuO in the ferrite composition escape and the valences of Fe and Cu are reduced. Part is Fe
"→Fe" and Cu"→Cu+. As a result, the ferrite element body 4 becomes a semiconductor and has a low resistance, whereas the specific resistance of NiZn ferrite when fired in air is 109 Ωcm or more. 10~104Ωcm
A small resistivity was obtained.
上記のようにして製造された積層型ＬＲフィルタ１０に
あっては、内部電極５によって付与されたインダンタン
スＬとフェライト素体４によってけ与された抵抗Ｒとに
よって第３図のようなインダクタンスＬと抵抗Ｒからな
るフィルタが構成されるので、従来のインダクタンス素
子としてのみ働く積層型チップコイルに外部抵抗体を外
付けしたのと同じ機能を得ることができる．すなわち、
この積層型ＬＲフィルタ１０の周波数−インピーダンス
特性は第４図に示すようになり、積層型チップコイルに
抵抗体を並列に外付けした時の周波数−インピーダンス
特性（第８図の曲線ロ）と同様、共振点のない滑らかな
周波数−インピーダンス特性を得ることができた。しか
も、フェライト素体４を低抵抗化することによって内部
抵抗を形成しているので、外形寸法が大きくなることが
なく、部品を小形化でき、従来のように外付け抵抗体を
用いる場合と比較すると、部品点数を少なくできて電気
回路をコンパクト化して高集積化を図れ、また外付け抵
抗体を半田付けする手間が省けると共に半田付け不良の
おそれがなくて接続信頼性が向上し、コストも安価にで
きる．また、電極材料として安価な銅を使用すると酸化
し易いという問題があるが、本発明にあっては内部及び
外部電極５．６を低酸素濃度雰囲気で焼成しているので
、電極材料に銅を使用しても焼成時における酸化を防止
でき、コストをより安価に抑えることができる。さらに
、外部に露出している外部電極６の表面にＮｉメッキや
Ｓｎメッキ等を施せば、焼成後も外部電ｉ６の酸化を防
止することができる．
なお、上記の説明では、積層型ＬＲフィルタを個々に製
造するように述べたが、実際の量産工程では、内部電極
の繰り返しパターンを印刷された大きな印刷マザーシ一
トの両面に大きなダミーのマザーシ一トを積層して加圧
一体化し、この生成形体をカットして一度に多数のフェ
ライト素体を製作する．
第５図に示すものは本発明の他例であり，印刷シ一ト７
の一方表面において、外部引き出し電極８間にジグザグ
状のインダクタ部９を設けたものである．
また、図示しないが、内部電極の構造としては、第７図
に従来例として示した内部電極のようにグリーンシート
の表裏に設けた０．７５ターンのＪ形電極をスルーホー
ルを通して連続させて１．５ターンのインダクタ部を形
成したものでもよい。In the multilayer LR filter 10 manufactured as described above, the inductance L as shown in FIG. Since a filter consisting of the resistor R and the resistor R is constructed, it is possible to obtain the same function as when an external resistor is attached externally to a conventional multilayer chip coil that functions only as an inductance element. That is,
The frequency-impedance characteristic of this multilayer LR filter 10 is shown in FIG. 4, and is similar to the frequency-impedance characteristic (curve RO in FIG. 8) when a resistor is externally connected to the multilayer chip coil in parallel. , we were able to obtain smooth frequency-impedance characteristics with no resonance points. Moreover, since the internal resistance is formed by lowering the resistance of the ferrite element 4, the external dimensions do not increase and the components can be made smaller, compared to the conventional case of using an external resistor. As a result, the number of parts can be reduced, the electrical circuit can be made more compact, and higher integration can be achieved.In addition, the trouble of soldering external resistors can be eliminated, and there is no risk of soldering defects, improving connection reliability and reducing costs. It can be done cheaply. In addition, there is a problem that copper is easily oxidized when cheap copper is used as an electrode material, but in the present invention, since the internal and external electrodes 5 and 6 are fired in a low oxygen concentration atmosphere, copper is used as an electrode material. Even if used, oxidation during firing can be prevented and costs can be kept lower. Furthermore, by applying Ni plating, Sn plating, etc. to the surface of the external electrode 6 exposed to the outside, oxidation of the external electrode 6 can be prevented even after firing. In the above explanation, it was stated that the laminated LR filters were manufactured individually, but in the actual mass production process, large dummy mother sheets are printed on both sides of a large printed mother sheet on which repeating patterns of internal electrodes are printed. A large number of ferrite bodies are produced at once by stacking the sheets and pressurizing them into one piece, and then cutting this formed body. What is shown in FIG. 5 is another example of the present invention, in which the printed sheet 7
A zigzag-shaped inductor section 9 is provided between the external lead-out electrodes 8 on one surface of the inductor. Although not shown, the structure of the internal electrode is that, like the internal electrode shown as a conventional example in FIG. An inductor portion having .5 turns may be formed.
［発明の効果］
本発明によれば、フェライト素体を低抵抗化させること
によりワンチップの積層型ＬＲフィルタ内に抵抗体を形
成することができる。このため、内部電極によるインダ
クタンスにフェライト素１水による抵抗を並列に接続し
たのと等価な回路の積層型ＬＲフィルタを製造すること
ができ、共振点のない周波数インピーダ特性を得ること
ができる．すなわち、滑らかなＥＭＩ除去特性が得られ
、使用回路等の制限をなくすことができ、汎用性が増す
。[Effects of the Invention] According to the present invention, a resistor can be formed in a one-chip multilayer LR filter by reducing the resistance of the ferrite element. Therefore, it is possible to manufacture a multilayer LR filter with a circuit equivalent to connecting a resistor made of ferrite element 1 water in parallel to the inductance provided by the internal electrode, and to obtain frequency impedance characteristics without resonance points. That is, smooth EMI removal characteristics can be obtained, and restrictions on the circuits used can be eliminated, and versatility can be increased.
また、外付け抵抗を必要としなくなるので、電子回路の
コストを安価にできると共に電子回路を小形化すること
ができ、外付け抵抗を半田付けずる必要がないので、接
続信頼性が増すと共に半田付け作業も不要となる。In addition, since an external resistor is not required, the cost of the electronic circuit can be reduced and the electronic circuit can be made smaller.Since there is no need to solder the external resistor, connection reliability is increased and the soldering No work is required.
また、内部電極及び外部電極が、焼き付け時に酸化しな
いので、銅のような安価な電極材料を用いることができ
る。Additionally, since the internal and external electrodes do not oxidize during baking, inexpensive electrode materials such as copper can be used.
第１図は本発明の一実施例における製造過程の斜視図、
第２図は同上の積層型ＬＲフィルタの断面図、第３図は
同上の等価回路図、第４図は同上の周波数一インピーダ
ンス特性を示すグラフ、第５図は本発明の他例における
製造過程の斜視図、第６図は従来例の斜視図、第７図は
従来例の製造過程における斜視図、第８図は従来例の周
波数一インピーダンス特性を示すグラフである。
１，２．３・・・グリーンシート
４・・・フェライト素体
５・・・内部電極
６・・・外部電極
第
１
図
第
２
図
第
４
図
１２＋
第
６
図
５１
第
８
図
１２＋FIG. 1 is a perspective view of the manufacturing process in an embodiment of the present invention;
FIG. 2 is a cross-sectional view of the multilayer LR filter same as above, FIG. 3 is an equivalent circuit diagram of same as above, FIG. 4 is a graph showing the frequency-impedance characteristic as above, and FIG. 5 is a manufacturing process in another example of the present invention FIG. 6 is a perspective view of the conventional example, FIG. 7 is a perspective view of the conventional example in the manufacturing process, and FIG. 8 is a graph showing frequency-impedance characteristics of the conventional example. 1, 2.3... Green sheet 4... Ferrite element body 5... Internal electrode 6... External electrode 1 Fig. 2 Fig. 4 Fig. 12+ Fig. 6 Fig. 51 Fig. 8 Fig. 12+
Claims (3)
ることによって形成したフェライト素体の内部に銀、銀
パラジウム、銅等の導電ペーストを用いてインダクタン
スとして働く内部電極を形成すると共に、このフェライ
ト素体の外面に銀、銀パラジウム、銅等の導電ペースト
を用いて外部電極を形成した後、 このフェライト素体をＨ＿２，ＣＯガス等の還元雰囲気
もしくはＮ＿２，Ａｒガス等の中性雰囲気で酸素濃度０
．１％以下の中で焼成することにより、前記フェライト
素体を低抵抗化することを特徴とする積層型ＬＲフィル
タの製造方法。(1) Inside a ferrite element body formed by laminating NiZn-based ferrite green sheets, an internal electrode that acts as an inductance is formed using a conductive paste of silver, silver palladium, copper, etc. After forming an external electrode on the outer surface using a conductive paste of silver, silver palladium, copper, etc., this ferrite element body is heated to zero oxygen concentration in a reducing atmosphere such as H_2, CO gas or a neutral atmosphere such as N_2, Ar gas.
．． A method for manufacturing a multilayer LR filter, characterized in that the resistance of the ferrite element is reduced by firing in a concentration of 1% or less.
れか一方を銅ペーストを用いて形成することを特徴とす
る請求項１に記載の積層型ＬＲフィルタの製造方法。(2) The method for manufacturing a multilayer LR filter according to claim 1, wherein at least one of the internal electrodes and the external electrodes is formed using copper paste.
したことを特徴とする請求項１又は２に記載の積層型Ｌ
Ｒフィルタの製造方法。(3) The laminated type L according to claim 1 or 2, wherein the surface of the external electrode is plated with Ni, Sn, etc.
Method of manufacturing R filter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1189988A JP2710244B2 (en) | 1989-07-20 | 1989-07-20 | Laminated LR filter and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1189988A JP2710244B2 (en) | 1989-07-20 | 1989-07-20 | Laminated LR filter and method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0353606A true JPH0353606A (en) | 1991-03-07 |
| JP2710244B2 JP2710244B2 (en) | 1998-02-10 |
Family
ID=16250512
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1189988A Expired - Fee Related JP2710244B2 (en) | 1989-07-20 | 1989-07-20 | Laminated LR filter and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2710244B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7317660B2 (en) | 1998-08-04 | 2008-01-08 | Teledyne Rd Instruments, Inc. | System and method for measuring wave directional spectrum and wave height |
| JP2010245088A (en) * | 2009-04-01 | 2010-10-28 | Murata Mfg Co Ltd | Method for manufacturing multilayer ceramic electronic component |
| WO2012173147A1 (en) * | 2011-06-15 | 2012-12-20 | 株式会社 村田製作所 | Laminated coil component and method for manufacturing said laminated coil component |
| WO2013024807A1 (en) * | 2011-08-18 | 2013-02-21 | 株式会社村田製作所 | Laminated coil component and method for manufacturing same |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5269563U (en) * | 1975-11-20 | 1977-05-24 | ||
| JPS63102215A (en) * | 1986-10-20 | 1988-05-07 | Taiyo Yuden Co Ltd | Manufacture of laminated type inductor |
| JPS63129604A (en) * | 1986-11-20 | 1988-06-02 | Fujitsu Ltd | High-frequency choke |
-
1989
- 1989-07-20 JP JP1189988A patent/JP2710244B2/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5269563U (en) * | 1975-11-20 | 1977-05-24 | ||
| JPS63102215A (en) * | 1986-10-20 | 1988-05-07 | Taiyo Yuden Co Ltd | Manufacture of laminated type inductor |
| JPS63129604A (en) * | 1986-11-20 | 1988-06-02 | Fujitsu Ltd | High-frequency choke |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7317660B2 (en) | 1998-08-04 | 2008-01-08 | Teledyne Rd Instruments, Inc. | System and method for measuring wave directional spectrum and wave height |
| US7545705B2 (en) | 1998-08-04 | 2009-06-09 | Teledyne Rd Instruments, Inc. | System and method for measuring wave directional spectrum and wave height |
| JP2010245088A (en) * | 2009-04-01 | 2010-10-28 | Murata Mfg Co Ltd | Method for manufacturing multilayer ceramic electronic component |
| WO2012173147A1 (en) * | 2011-06-15 | 2012-12-20 | 株式会社 村田製作所 | Laminated coil component and method for manufacturing said laminated coil component |
| JPWO2012173147A1 (en) * | 2011-06-15 | 2015-02-23 | 株式会社村田製作所 | Multilayer coil component and method for manufacturing the multilayer coil component |
| US9281113B2 (en) | 2011-06-15 | 2016-03-08 | Murata Manufacturing Co., Ltd. | Laminated coil component, and method of manufacturing the laminated coil component |
| WO2013024807A1 (en) * | 2011-08-18 | 2013-02-21 | 株式会社村田製作所 | Laminated coil component and method for manufacturing same |
| JPWO2013024807A1 (en) * | 2011-08-18 | 2015-03-05 | 株式会社村田製作所 | Multilayer coil component and manufacturing method thereof |
| US9299487B2 (en) | 2011-08-18 | 2016-03-29 | Murata Manufacturing Co., Ltd. | Laminated coil component and method for manufacturing same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2710244B2 (en) | 1998-02-10 |
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