JP4649817B2 - Palladium removing solution and method for removing palladium - Google Patents
Palladium removing solution and method for removing palladium Download PDFInfo
- Publication number
- JP4649817B2 JP4649817B2 JP2002513968A JP2002513968A JP4649817B2 JP 4649817 B2 JP4649817 B2 JP 4649817B2 JP 2002513968 A JP2002513968 A JP 2002513968A JP 2002513968 A JP2002513968 A JP 2002513968A JP 4649817 B2 JP4649817 B2 JP 4649817B2
- Authority
- JP
- Japan
- Prior art keywords
- palladium
- removing solution
- ether
- solution according
- nitrate
- 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 - Fee Related
Links
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/22—Secondary treatment of printed circuits
- H05K3/26—Cleaning or polishing of the conductive pattern
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F1/00—Etching metallic material by chemical means
- C23F1/10—Etching compositions
- C23F1/14—Aqueous compositions
- C23F1/16—Acidic compositions
- C23F1/30—Acidic compositions for etching other metallic material
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/07—Electric details
- H05K2201/0753—Insulation
- H05K2201/0761—Insulation resistance, e.g. of the surface of the PCB between the conductors
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/07—Treatments involving liquids, e.g. plating, rinsing
- H05K2203/0779—Treatments involving liquids, e.g. plating, rinsing characterised by the specific liquids involved
- H05K2203/0786—Using an aqueous solution, e.g. for cleaning or during drilling of holes
- H05K2203/0789—Aqueous acid solution, e.g. for cleaning or etching
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/12—Using specific substances
- H05K2203/121—Metallo-organic compounds
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
- H05K3/18—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using precipitation techniques to apply the conductive material
- H05K3/181—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using precipitation techniques to apply the conductive material by electroless plating
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Manufacturing Of Printed Wiring (AREA)
Description
技術分野
本発明は、パラジウム除去液および該除去液を使用したパラジウムの除去方法に関し、さらに詳しくは、被処理基板の表面に存在するパラジウムを、被処理基板にダメージを与えずに除去するための除去液および除去方法に関するものである。
背景技術
回路パターン形成法の１つにアディティブ法がある。このアディディブ法では、絶縁性基板の表面全体にパラジウムを付与した後、パラジウム層の上に、無電解銅めっき法で銅めっき層が形成される。この銅めっき層の回路パターンとなる部分だけをエッチングレジストで覆い、次にレジストで覆われていない部分の銅はエッチングにより除去される。その後、エッチングレジストを除去し回路パターンが形成される。
この従来方法によれば、回路パターン形成後に絶縁性基板表面が現れるが、この絶縁性基板表面には前記のパラジウムが残存している。パラジウムは無電解めっきの際の触媒として働き、導体層を容易に形成させるのに有効であるが、通常のエッチング液に溶解しにくいため、上記の銅エッチング後も残存し、回路パターンの絶縁性を低下させる。
また回路パターンの表面全体あるいは部品接合用のパッド部分には表面処理として無電解ニッケルめっき、無電解金めっきなどを行うことがあるが、絶縁性基板表面にパラジウムが残っていると、このパラジウムが触媒となって不要な部分にもニッケルや金が付着して回路パターンの絶縁性が悪くなる。
したがって、この残存パラジウムを除去することは、高品質の回路基板を得るためには、極めて重要なことである。このため従来のアディティブ法においては、エッチングレジストを剥離した後、基板表面の不要なパラジウムを次のような方法で除去していた。
（１）基板をヨウ素／ヨウ化アンモニウム溶液に浸漬し、パラジウムを溶解する方法。
（２）基板を過マンガン酸カリウム溶液に浸漬し、パラジウムを溶解する方法。
（３）ＲＩＥ（リアクティブイオンエッチング）等の真空排気装置を用いて、パラジウムを基板表面から離脱させる方法。
しかしながら、前述した従来のパラジウムの除去方法には以下に示す問題点があった。
（１）ヨウ素／ヨウ化アンモニウム溶液に浸漬する方法では、パラジウム溶解と同時に銅も溶解するため、配線の細りや断線が発生しやすい。
（２）過マンガン酸カリウム溶液に浸漬する方法では、樹脂基板表面が酸化され、その表面が微細な凹凸形状となる。この樹脂酸化がパラジウムの溶解より速く進むため、樹脂酸化層の凹部に存在するパラジウムに処理液が接触しにくく、部分的にパラジウム残りが発生する。
（３）真空排気装置を用いる方法は、上記のウエット処理に比べ装置が高価なことや、処理できる基板枚数に制限が生じ易いことから配線板製造コストが高くつく。
また、特開平３−２５４１７９号公報及び特開平４−１７９１９１号公報などには、基板を過マンガン酸カリウム溶液に浸漬した後、所望に応じて超音波水洗し、さらに芳香族ニトロ化合物、アミン化合物、アミノカルボン酸、カルボン酸、水酸化ナトリウム、及び硫酸ヒドロキシアンモニウムを含む溶液に浸漬し、パラジウムを除去する方法が開示されている。しかしながら、これらの除去液では、基板表面の樹脂酸化層と共にパラジウムを除去するものであるため、過マンガン酸カリウム溶液により基板表面が粗化されるばかりか銅回路パターンと基板の界面部も浸食される等の種々の欠点を有する。
発明の開示
本発明の目的は、前記課題を解決する被処理基板の表面に存在するパラジウムを、被処理基板にダメージを与えずに除去するための除去液および除去方法を提供することにある。さらに詳しくは、本発明の目的は、回路基板の製造工程において回路パターン形成後に絶縁性基板表面に残留するパラジウムを容易に除去でき、且つ配線材料や絶縁性基板等を浸蝕しないパラジウム除去液および該除去液を使用した除去方法を提供することにある。
本発明者らは前記目的を達成すべく鋭意研究を重ねた結果、（ａ）硝酸塩、（ｂ）パラジウム酸化物を水溶化する水溶化剤、（ｃ）水、および必要に応じて（ｄ）湿潤剤及び／又はキレート化剤からなる溶液が、アディティブ法により回路パターンを形成後の絶縁性基板表面に残留するパラジウムを短時間で容易に除去でき、回路パターンの絶縁性を向上させ、高信頼性のプリント配線基板を製造できることを見出し、この知見に基づいて本発明を完成した。
即ち、本発明の第一の態様は、（ａ）硝酸塩、（ｂ）パラジウム酸化物を水溶化する水溶化剤および（ｃ）水を含有することを特徴とするパラジウム除去液である。該除去液は、必要に応じて、（ｄ）湿潤剤及び／又は（ｅ）キレート化剤を含有してもよい。
本発明の第二の態様は、絶縁性基板表面にパラジウムを付着してパラジウム層を形成し、パラジウム層の上に銅メッキ層を形成し、該メッキ層にレジストを施した後エッチングして回路パターンを形成し、レジストを剥離した後、基板表面に残存するパラジウムを、前記パラジウム除去液を用いて除去するパラジウムの除去方法である。
発明を実施するための最良の形態
前記（ａ）硝酸塩としては、硝酸アンモニウム、硝酸リチウム、硝酸亜鉛、硝酸マンガン、硝酸ニッケル、硝酸コバルト、硝酸ナトリウム、及び硝酸カリウムがあげられ、特に好ましくは硝酸アンモニウムである。硝酸塩はパラジウムを酸化する作用を有する。硝酸塩のパラジウム除去液中の濃度は０．００１〜４０重量％であり、好ましくは０．００５〜３０重量％である。
前記（ｂ）パラジウム酸化物を水溶化する物質（水溶化剤）としては、無機酸とその塩が挙げられ、好ましくは、塩酸、硝酸、硫酸、塩化アンモニウム、塩化アルミニウムなどの塩酸塩、硫酸アンモニウム、硫酸アルミニウムなどの硫酸塩等が挙げられる。水溶化剤のパラジウム除去液中の濃度は０．０１〜５０重量％、好ましくは０．０５〜３０重量％である。
本発明の効果を損なわない範囲で、酸化力を高める為に他のパラジウム酸化性物質を混合したり、パラジウム酸化物を水溶化する能力を挙げる為に他のパラジウム酸化物を水溶化する物質を混合してもよい。
本発明のパラジウム除去液は、前記成分（ａ）〜（ｃ）に加えて、湿潤剤（ｄ）を更に含有していてもよい。湿潤剤（ｄ）としては、界面活性剤、アルコール類、エーテル類が挙げられる。界面活性剤としては、カチオン系、ノニオン系、アニオン系等が挙げられる。アルコール類としては、エチルアルコール、イソプロピルアルコール、ブタノール、エチレングリコール、ジエチレングリコール、プロピレングリコール、ジプロピレングリコールが挙げられる。エーテル類としてエチレングリコールモノエチルエーテル、エチレングリコールモノブチルエーテル、ジエチレングリコールモノメチルエーテル、ジエチレングリコールモノエチルエーテル、ジエチレングリコールモノブチルエーテル、プロピレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテル、プロピレングリコールモノブチルエーテル、ジプロピレングリコールモノメチルエーテル、ジプロピレングリコールモノエチルエーテル、ジプロピレングリコールモノブチルエーテル、ジエチレングリコールジメチルエーテル、ジプロピレングリコールジメチルエーテル、ポリオキシエチレンメチルフェニルエーテル、ポリオキシエチレンエチルフェニルエーテル、ポリオキシエチレンオクチルフェニルエーテル、ポリオキシエチレンノニルフェニルエーテル等が挙げられる。
上記湿潤剤は、単独でも２種類以上組み合わせても使用できる。上記湿潤剤のパラジウム除去液中の濃度は０．００１〜１０重量％、好ましくは０．００５〜５重量％、特に好ましくは０．００５〜１重量％である。
本発明のパラジウム除去液は、前記成分（ａ）〜（ｃ）或いは成分（ａ）〜（ｄ）に加えて、キレート化剤（ｅ）を更に含有してもよい。キレート化剤とは、パラジウムと錯体を形成する化合物であり、ジメチルグリオキシム、チオ尿素、チオオキシン（８−メルカプトキノリン）、ジチゾン、２−ニトロソ−１−ナフトール、ｐ−ニトロソジメチルアニリンなどが挙げられる。ジメチルグリオキシム及びチオ尿素が特に好ましい。
キレート化剤（ｅ）は、パラジウム酸化物の水溶化剤として作用するだけでなく、絶縁性基板の表面粗化凹部に少量残存するパラジウムと錯体を形成し、パラジウムを回路パターン形成後の無電解ニッケルメッキ、無電解金メッキなどに対して不活性にし、不要な部分にニッケル、金などが付着して回路パターンの絶縁性が悪くなるのを防止する。
キレート化剤のパラジウム除去液中の濃度は０．０１〜５重量％、好ましくは０．０１〜２重量％、特に好ましくは０．０５〜２重量％である。
本発明のパラジウム除去液は、上記硝酸塩、水溶化剤、任意成分の湿潤剤及び／又はキレート化剤、及び残部の水とからなる水性の液であり、その状態は、分散液あるいは懸濁液であっても良いが、通常は水溶液である。
本発明のパラジウム除去液は、成分（ａ）〜（ｂ）、及び任意成分（ｄ）及び／又は（ｅ）を水に溶解、分散、又は懸濁することにより製造される。各成分の添加順序は特に制限されない。
本発明のパラジウム除去方法は、通常、常温〜８０℃で被処理基板をパラジウム除去液に１〜１０分間浸漬することにより行う。パラジウム除去液のｐＨは、通常０〜５の範囲で使用される。ｐＨの調整は成分（ｂ）として使用される無機酸の添加量を変えることにより行う。パラジウム除去液の使用量は、パラジウムが被処理基板から有効に除去される量であり、当業者であれば容易に決めることができる。本発明のパラジウム除去方法により、回路パターン形成後に残存するパラジウムを実質的に完全に（回路基板に対する残留パラジウム濃度が５ｐｐｍ以下）除去することができる。
次に実施例および比較例により本発明をさらに具体的に説明する。但し、本発明はこれらの実施例により制限されるものではない。
図１に、回路基板の製造における回路パターン形成までの工程を示した。
図１ａは絶縁性基板１上にパラジウム触媒層２を形成した状態を示している。このパラジウムは通常、絶縁性基板に吸着された状態で極めて薄い層をなして存在し無電解めっきの場合における触媒として機能する。
絶縁性基板表面のパラジウム触媒層２の上には、図１ｂに示すように無電解めっきによる銅めっき層からなる導体層３が形成される。この導体層は、無電解めっき面に必要に応じて電気めっきを施して形成した導体層であってもよい。
次に、図１ｃに示すように、導体層３の回路となるべき部分をフォトレジスト層４で覆い、その後導体層３の非被覆部分をエッチング液で溶解除去する。この場合レジストとしては、例えば、ドライフォトフイルム、フォトレジストインク、スクリーン印刷レジスト等が使用でき、また、エッチング液としては、硫酸と過酸化水素混合液、塩化第二銅含有液、塩化第二鉄含有液等が使用できる。
エッチング後、フォトレジストを除去することにより図１ｄに示すように絶縁性基板１の表面に導体回路３ａが形成される。銅めっき層をエッチングした後、絶縁性基板１の表面に付着したパラジウム２ａは除去されずに絶縁性樹脂に吸着された状態でそのまま残存する。
実施例１〜７
上記のパラジウム残存回路基板を表１で示したパラジウム除去液を用いて所定の条件で浸漬した後、純水でリンスして乾燥した。しかる後に、回路間隔が２０ミクロンの回路部分について絶縁抵抗値の測定、絶縁性基板表面について蛍光Ｘ線分析法およびＸ線マイクロアナライザーによるパラジウム残存量の測定、回路パターン部について無電解ニッケルめっきを施した際の、絶縁性基板表面でのニッケルの析出の有無、また回路パターン部について銅の腐食性の有無を観察した。この測定結果と観察結果は、それぞれ下記の判断基準に従って評価した。その結果を表１に示した。
１ 絶縁性
Ａ：処理前絶縁抵抗値 数ＭΩ→処理後絶縁抵抗値 ∞
Ｃ：処理前絶縁抵抗値 数ＭΩ→処理後絶縁抵抗値 数ＭΩ
２ パラジウム除去性
Ａ：完全に除去された。
Ｂ：一部残存していた。
Ｃ：大部分残存していた。
３ ニッケル析出性
Ａ＋：析出が全く認められなかった。
Ａ：析出がほとんど認められなかった。
Ｂ：一部析出が認められた。
Ｃ：析出が認められた。
４ 銅腐食性
Ａ：腐食が認められなかった。
Ｂ：一部腐食が認められた。
Ｃ：全面に腐食が認められた。
表３に示した組成のパラジウム除去液を使用する以外は、上記実施例１〜７と同様にした。実験結果を表２に示した。
キレート化剤を含むパラジウム除去液を用いた以外は実施例１〜７と同様にした。結果を表３に示した。
本発明のパラジウム除去液に浸漬することにより、被処理基板の表面に存在するパラジウムを除去することができる。本発明のパラジウム除去液は、特に、絶縁性基板の表面に残留するパラジウムを除去するのに好適であり、銅配線を浸蝕することがなく、また絶縁性基板表面をも粗らすことがないので、回路パターンの絶縁性を向上させることができる。
さらに、回路パターンに無電解ニッケルめっきや無電解金めっきなどのめっき処理を施す場合にも、表面のパラジウムが除去されているので絶縁性基板表面へのめっき付着による絶縁性の低下を未然に防止することができる。
【図面の簡単な説明】
図１ａ〜図１ｄは、プリント配線基板の製造において、本発明のパラジウム除去液により処理される回路パターン形成基板までの製造工程を示す模式図である。 TECHNICAL FIELD The present invention relates to a palladium removing solution and a method for removing palladium using the removing solution, and more specifically, palladium present on the surface of a substrate to be treated without damaging the substrate to be treated. The present invention relates to a removing liquid and a removing method.
BACKGROUND ART An additive method is one of circuit pattern forming methods. In this additive method, after palladium is applied to the entire surface of the insulating substrate, a copper plating layer is formed on the palladium layer by an electroless copper plating method. Only the portion of the copper plating layer that will be the circuit pattern is covered with an etching resist, and then the copper that is not covered with the resist is removed by etching. Thereafter, the etching resist is removed to form a circuit pattern.
According to this conventional method, the surface of the insulating substrate appears after the circuit pattern is formed, but the palladium remains on the surface of the insulating substrate. Palladium acts as a catalyst for electroless plating and is effective for easily forming a conductor layer, but it remains difficult to dissolve in a normal etching solution, so it remains after the above copper etching, resulting in an insulating circuit pattern. Reduce.
In addition, electroless nickel plating, electroless gold plating, etc. may be applied to the entire circuit pattern surface or pad bonding parts as surface treatment. If palladium remains on the surface of the insulating substrate, this palladium Nickel and gold adhere to unnecessary portions as a catalyst, and the insulation of the circuit pattern deteriorates.
Therefore, removing this residual palladium is extremely important for obtaining a high-quality circuit board. For this reason, in the conventional additive method, after removing the etching resist, unnecessary palladium on the surface of the substrate is removed by the following method.
(1) A method in which palladium is dissolved by immersing the substrate in an iodine / ammonium iodide solution.
(2) A method in which the substrate is immersed in a potassium permanganate solution to dissolve palladium.
(3) A method of separating palladium from the substrate surface using a vacuum exhaust apparatus such as RIE (reactive ion etching).
However, the conventional palladium removal method described above has the following problems.
(1) In the method of immersing in an iodine / ammonium iodide solution, copper is dissolved at the same time as dissolution of palladium, so that wiring thinning and disconnection are likely to occur.
(2) In the method of immersing in a potassium permanganate solution, the surface of the resin substrate is oxidized, and the surface has a fine uneven shape. Since this resin oxidation proceeds faster than the dissolution of palladium, the treatment liquid is less likely to come into contact with the palladium present in the recesses of the resin oxide layer, and a palladium residue is partially generated.
(3) The method using the vacuum evacuation device is expensive compared to the above-described wet processing, and the number of substrates that can be processed is likely to be limited, resulting in high wiring board manufacturing costs.
JP-A-3-254179 and JP-A-4-179191 disclose that a substrate is immersed in a potassium permanganate solution and then ultrasonically washed as desired, and further an aromatic nitro compound and an amine compound. A method of removing palladium by immersing in a solution containing aminocarboxylic acid, carboxylic acid, sodium hydroxide, and hydroxyammonium sulfate is disclosed. However, since these removal liquids remove palladium together with the resin oxide layer on the substrate surface, not only the surface of the substrate is roughened by the potassium permanganate solution but also the interface between the copper circuit pattern and the substrate is eroded. Have various disadvantages.
DISCLOSURE OF THE INVENTION An object of the present invention is to provide a removing liquid and a removing method for removing palladium present on the surface of a substrate to be processed without damaging the substrate to be processed, which solves the above problems. There is. More specifically, an object of the present invention is to remove palladium remaining on the surface of an insulating substrate after forming a circuit pattern in a circuit board manufacturing process, and to remove a palladium removing liquid that does not corrode wiring materials, insulating substrates and the like. It is providing the removal method which uses a removal liquid.
As a result of intensive studies to achieve the above object, the present inventors have (a) nitrate, (b) a water-solubilizing agent for water-solubilizing palladium oxide, (c) water, and (d) as necessary. A solution consisting of a wetting agent and / or a chelating agent can easily remove palladium remaining on the surface of the insulating substrate after the circuit pattern is formed by the additive method in a short time, improving the insulation of the circuit pattern, and highly reliable. The present invention was completed based on this finding.
That is, the first aspect of the present invention is a palladium removing liquid characterized by containing (a) nitrate, (b) a water solubilizing agent that solubilizes palladium oxide, and (c) water. The removal liquid may contain (d) a wetting agent and / or (e) a chelating agent, if necessary.
According to the second aspect of the present invention, a palladium layer is formed by attaching palladium to the surface of an insulating substrate, a copper plating layer is formed on the palladium layer, a resist is applied to the plating layer, and then etching is performed. This is a palladium removal method in which after forming a pattern and stripping the resist, palladium remaining on the substrate surface is removed using the palladium removing solution.
Best Mode for Carrying Out the Invention Examples of the (a) nitrate include ammonium nitrate, lithium nitrate, zinc nitrate, manganese nitrate, nickel nitrate, cobalt nitrate, sodium nitrate, and potassium nitrate, and particularly preferably Ammonium nitrate. Nitrate has the effect of oxidizing palladium. The concentration of nitrate in the palladium removal solution is 0.001 to 40% by weight, preferably 0.005 to 30% by weight.
Examples of the substance (water-solubilizing agent) for solubilizing the palladium oxide (b) include inorganic acids and salts thereof, preferably hydrochlorides such as hydrochloric acid, nitric acid, sulfuric acid, ammonium chloride, aluminum chloride, ammonium sulfate, Examples thereof include sulfates such as aluminum sulfate. The concentration of the water solubilizer in the palladium removing solution is 0.01 to 50% by weight, preferably 0.05 to 30% by weight.
In order not to impair the effects of the present invention, other palladium oxidizing substances are mixed in order to increase the oxidizing power, or substances that solubilize other palladium oxides to increase the ability to solubilize palladium oxides. You may mix.
The palladium removing solution of the present invention may further contain a wetting agent (d) in addition to the components (a) to (c). Examples of the wetting agent (d) include surfactants, alcohols, and ethers. Surfactants include cationic, nonionic, anionic and the like. Examples of alcohols include ethyl alcohol, isopropyl alcohol, butanol, ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol. As ethers, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, di Propylene glycol monoethyl ether, dipropylene glycol monobutyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, polyoxyethylene methyl phenyl ether, polyoxyethylene ethyl phenyl ether, polyoxyethylene octyl phenyl ether, polyethylene Polyoxyethylene nonylphenyl ether.
These wetting agents can be used alone or in combination of two or more. The concentration of the wetting agent in the palladium removing solution is 0.001 to 10% by weight, preferably 0.005 to 5% by weight, and particularly preferably 0.005 to 1% by weight.
The palladium removing solution of the present invention may further contain a chelating agent (e) in addition to the components (a) to (c) or the components (a) to (d). A chelating agent is a compound that forms a complex with palladium, and examples thereof include dimethylglyoxime, thiourea, thiooxin (8-mercaptoquinoline), dithizone, 2-nitroso-1-naphthol, and p-nitrosodimethylaniline. . Dimethylglyoxime and thiourea are particularly preferred.
The chelating agent (e) not only acts as a water-solubilizing agent for the palladium oxide, but also forms a complex with a small amount of palladium remaining on the surface roughened recesses of the insulating substrate. It is inactive against nickel plating, electroless gold plating, etc., and prevents the insulating properties of the circuit pattern from being deteriorated due to nickel, gold, etc. adhering to unnecessary portions.
The concentration of the chelating agent in the palladium removing solution is 0.01 to 5% by weight, preferably 0.01 to 2% by weight, particularly preferably 0.05 to 2% by weight.
The palladium removing liquid of the present invention is an aqueous liquid composed of the above-mentioned nitrate, water-soluble agent, optional wetting agent and / or chelating agent, and the balance of water, and the state thereof is a dispersion or suspension. Usually, it is an aqueous solution.
The palladium removing solution of the present invention is produced by dissolving, dispersing, or suspending components (a) to (b) and optional components (d) and / or (e) in water. The addition order of each component is not particularly limited.
The palladium removal method of the present invention is usually performed by immersing the substrate to be treated in a palladium removal solution at room temperature to 80 ° C. for 1 to 10 minutes. The pH of the palladium removing solution is usually used in the range of 0 to 5. The pH is adjusted by changing the amount of the inorganic acid used as component (b). The amount of the palladium removing solution used is an amount by which palladium is effectively removed from the substrate to be processed, and can be easily determined by those skilled in the art. By the palladium removing method of the present invention, palladium remaining after the circuit pattern is formed can be removed substantially completely (residual palladium concentration with respect to the circuit board is 5 ppm or less).
Next, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited by these examples.
FIG. 1 shows a process until formation of a circuit pattern in manufacturing a circuit board.
FIG. 1 a shows a state in which a palladium catalyst layer 2 is formed on an insulating
On the palladium catalyst layer 2 on the surface of the insulating substrate, as shown in FIG. 1b, a
Next, as shown in FIG. 1c, a portion of the
After the etching, the photoresist is removed to form a
Examples 1-7
The palladium remaining circuit board was immersed in the palladium removing solution shown in Table 1 under predetermined conditions, rinsed with pure water and dried. After that, the insulation resistance value is measured for the circuit portion having a circuit interval of 20 microns, the residual amount of palladium is measured by the fluorescent X-ray analysis method and the X-ray microanalyzer on the surface of the insulating substrate, and the electroless nickel plating is applied to the circuit pattern portion. The presence or absence of nickel deposition on the surface of the insulating substrate and the presence or absence of copper corrosiveness in the circuit pattern portion were observed. The measurement results and the observation results were evaluated according to the following criteria. The results are shown in Table 1.
1 Insulation A: Insulation resistance before treatment Several MΩ → Insulation resistance after treatment ∞
C: Insulation resistance value before treatment: several MΩ → Insulation resistance value after treatment: several MΩ
2 Palladium removability A: Completely removed.
B: Some remained.
C: Most remained.
3 Nickel precipitation A + : no precipitation was observed at all.
A: Almost no precipitation was observed.
B: Partial precipitation was observed.
C: Precipitation was observed.
4 Copper corrosiveness A: Corrosion was not recognized.
B: Partial corrosion was observed.
C: Corrosion was observed on the entire surface.
Except using the palladium removal liquid of the composition shown in Table 3, it carried out similarly to the said Examples 1-7. The experimental results are shown in Table 2.
The same procedure as in Examples 1 to 7 except that a palladium removing solution containing a chelating agent was used. The results are shown in Table 3.
In addition, when the circuit pattern is plated with electroless nickel plating or electroless gold plating, the palladium on the surface is removed, so it is possible to prevent deterioration of insulation due to adhesion of the plating to the surface of the insulating substrate. can do.
[Brief description of the drawings]
FIGS. 1a to 1d are schematic views showing manufacturing steps up to a circuit pattern forming substrate to be processed by the palladium removing solution of the present invention in manufacturing a printed wiring board.
Claims (14)
前記硝酸塩が、硝酸アンモニウム、硝酸リチウム、硝酸亜鉛、硝酸マンガン、硝酸ニッケル、硝酸コバルト、硝酸ナトリウム、及び硝酸カリウムからなる群より選ばれた少なくとも一の化合物であることを特徴とするパラジウム除去液。(A) a nitrate, (b) a water solubilizing agent that solubilizes palladium oxide, and (c) a palladium removing solution containing water ,
A palladium removing solution , wherein the nitrate is at least one compound selected from the group consisting of ammonium nitrate, lithium nitrate, zinc nitrate, manganese nitrate, nickel nitrate, cobalt nitrate, sodium nitrate, and potassium nitrate .
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000225938 | 2000-07-26 | ||
| PCT/JP2001/006334 WO2002008491A1 (en) | 2000-07-26 | 2001-07-23 | Palladium removing solution and method for removing palladium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP4649817B2 true JP4649817B2 (en) | 2011-03-16 |
Family
ID=18719641
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002513968A Expired - Fee Related JP4649817B2 (en) | 2000-07-26 | 2001-07-23 | Palladium removing solution and method for removing palladium |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP4649817B2 (en) |
| KR (1) | KR100761608B1 (en) |
| TW (1) | TW539773B (en) |
| WO (1) | WO2002008491A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3168326B1 (en) | 2014-07-10 | 2020-07-29 | Okuno Chemical Industries Co., Ltd. | Resin plating method |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7189289B2 (en) * | 2002-02-08 | 2007-03-13 | Sk Corporation | Cleaning agent and method for cleaning heater tubes |
| AU2003902423A0 (en) * | 2003-05-19 | 2003-06-05 | Intellirad Solutions Pty. Ltd | Apparatus and method |
| JP2008106354A (en) * | 2006-09-25 | 2008-05-08 | Mec Kk | Metal removing solution and metal removing method using the same |
| JP5304637B2 (en) * | 2007-03-12 | 2013-10-02 | 三菱化学株式会社 | Etching solution and etching method |
| KR20110016418A (en) | 2009-08-11 | 2011-02-17 | 동우 화인켐 주식회사 | Resist stripper composition and a method of stripping resist using the same |
| CN102191501B (en) * | 2010-03-10 | 2013-01-30 | 比亚迪股份有限公司 | Palladium remover and preparation method thereof, and plastic surface activation method |
| JP5195858B2 (en) * | 2010-09-22 | 2013-05-15 | 日立金属株式会社 | Silicon nitride substrate |
| CN103945654A (en) * | 2013-01-18 | 2014-07-23 | 北大方正集团有限公司 | Method for leaving palladium ions in non-metallized holes of passivation circuit board and circuit board manufactured through same |
| CN103249254A (en) * | 2013-04-22 | 2013-08-14 | 胜宏科技（惠州）股份有限公司 | Method of removing palladium in NPTHs of PCB |
| CN114945246A (en) * | 2022-05-11 | 2022-08-26 | 深圳市松柏实业发展有限公司 | Palladium removal process of circuit board, palladium passivator with non-metal holes and preparation method of palladium passivator |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5112582B1 (en) * | 1970-10-17 | 1976-04-20 | ||
| JPS58500765A (en) * | 1981-05-21 | 1983-05-12 | テレフオンアクチ−ボラゲツト エル エム エリクソン | A method for chemically stripping a plating layer containing palladium and at least one of copper and nickel, and a bath used in the method |
| JPS6421020A (en) * | 1987-07-15 | 1989-01-24 | Fuji Electric Co Ltd | Etching recovery method for palladium |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6030520A (en) | 1997-04-23 | 2000-02-29 | The Regents Of The University Of California | Nitrate reduction |
-
2001
- 2001-07-23 KR KR1020037000582A patent/KR100761608B1/en not_active IP Right Cessation
- 2001-07-23 JP JP2002513968A patent/JP4649817B2/en not_active Expired - Fee Related
- 2001-07-23 WO PCT/JP2001/006334 patent/WO2002008491A1/en active Application Filing
- 2001-07-26 TW TW090118283A patent/TW539773B/en not_active IP Right Cessation
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5112582B1 (en) * | 1970-10-17 | 1976-04-20 | ||
| JPS58500765A (en) * | 1981-05-21 | 1983-05-12 | テレフオンアクチ−ボラゲツト エル エム エリクソン | A method for chemically stripping a plating layer containing palladium and at least one of copper and nickel, and a bath used in the method |
| JPS6421020A (en) * | 1987-07-15 | 1989-01-24 | Fuji Electric Co Ltd | Etching recovery method for palladium |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3168326B1 (en) | 2014-07-10 | 2020-07-29 | Okuno Chemical Industries Co., Ltd. | Resin plating method |
| US11047052B2 (en) | 2014-07-10 | 2021-06-29 | Okuno Chemical Industries Co., Ltd. | Resin plating method |
| EP3168326B2 (en) † | 2014-07-10 | 2023-09-20 | Okuno Chemical Industries Co., Ltd. | Resin plating method |
Also Published As
| Publication number | Publication date |
|---|---|
| TW539773B (en) | 2003-07-01 |
| WO2002008491A1 (en) | 2002-01-31 |
| KR20030015392A (en) | 2003-02-20 |
| KR100761608B1 (en) | 2007-09-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4224652B2 (en) | Resist stripping solution and resist stripping method using the same | |
| JP3810607B2 (en) | Cleaning aqueous solution for removing impurities on substrate surface of integrated circuit and cleaning method using the same | |
| KR100340274B1 (en) | Cleaning Method of Semiconductor Substrate | |
| WO2006103751A1 (en) | Copper etchant and method of etching | |
| JP3481379B2 (en) | Electroplating method | |
| JP4649817B2 (en) | Palladium removing solution and method for removing palladium | |
| US6080709A (en) | Cleaning solution for cleaning substrates to which a metallic wiring has been applied | |
| JP2001100436A (en) | Resist removing solution composition | |
| JP2010093126A (en) | Alkaline aqueous solution composition for substrate processing | |
| JP2006111953A (en) | Etching agent for copper or copper alloy, its manufacturing method, replenishing liquid, and method for manufacturing wiring substrate | |
| JP2001140084A (en) | Etching solution for nickel or nickel alloy | |
| EP0270658A1 (en) | Process for stripping tin or tin-lead alloy from copper | |
| JP3165801B2 (en) | Cleaning solution | |
| JP2005105410A (en) | Copper etchant and etching method | |
| KR101050011B1 (en) | Release agent composition and peeling cleaning method using the same | |
| TW200304507A (en) | Method of stripping silver from a printed circuit board | |
| JP4689855B2 (en) | Residue stripper composition and method of use thereof | |
| EP0906968A1 (en) | Composition and method for stripping solder and tin from printed circuit boards | |
| JP4418916B2 (en) | Etching composition | |
| JP4637010B2 (en) | Release agent composition | |
| EP1917340A1 (en) | Aqueous solution and method for removing ionic contaminants from the surface of a workpiece | |
| JP3540887B2 (en) | Selective nickel stripping solution and stripping method using the same | |
| JP4296320B2 (en) | Resist stripper composition and method of using the same | |
| JP2006210857A (en) | Cleaning liquid composition for removal of impurity, and impurity removal method using the composition | |
| JP2587254B2 (en) | Removal method of tin or tin-lead alloy |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20080508 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100831 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20101022 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20101116 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20101129 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131224 Year of fee payment: 3 |
|
| LAPS | Cancellation because of no payment of annual fees |