JPS6133907B2 - - Google Patents
Info
- Publication number
- JPS6133907B2 JPS6133907B2 JP16410979A JP16410979A JPS6133907B2 JP S6133907 B2 JPS6133907 B2 JP S6133907B2 JP 16410979 A JP16410979 A JP 16410979A JP 16410979 A JP16410979 A JP 16410979A JP S6133907 B2 JPS6133907 B2 JP S6133907B2
- Authority
- JP
- Japan
- Prior art keywords
- copper foil
- zinc
- amount
- coating
- chromium oxide
- 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
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 64
- 239000011889 copper foil Substances 0.000 claims description 60
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 48
- 239000011701 zinc Substances 0.000 claims description 48
- 229910052725 zinc Inorganic materials 0.000 claims description 40
- 238000000576 coating method Methods 0.000 claims description 35
- 239000011248 coating agent Substances 0.000 claims description 34
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 25
- 229910000423 chromium oxide Inorganic materials 0.000 claims description 25
- 238000000034 method Methods 0.000 claims description 13
- 239000011651 chromium Substances 0.000 claims description 12
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 11
- 229910052804 chromium Inorganic materials 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 238000011282 treatment Methods 0.000 description 36
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 18
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 15
- 230000002265 prevention Effects 0.000 description 13
- 239000000758 substrate Substances 0.000 description 13
- 229910000679 solder Inorganic materials 0.000 description 11
- 238000003475 lamination Methods 0.000 description 8
- XLOMVQKBTHCTTD-UHFFFAOYSA-N zinc oxide Inorganic materials [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 8
- 238000005530 etching Methods 0.000 description 7
- 239000005011 phenolic resin Substances 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 6
- 239000010410 layer Substances 0.000 description 6
- 229920001568 phenolic resin Polymers 0.000 description 6
- 238000005406 washing Methods 0.000 description 6
- 238000002845 discoloration Methods 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 238000005868 electrolysis reaction Methods 0.000 description 4
- 239000003822 epoxy resin Substances 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 238000007654 immersion Methods 0.000 description 4
- 229920000647 polyepoxide Polymers 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- NWONKYPBYAMBJT-UHFFFAOYSA-L zinc sulfate Chemical compound [Zn+2].[O-]S([O-])(=O)=O NWONKYPBYAMBJT-UHFFFAOYSA-L 0.000 description 4
- 229960001763 zinc sulfate Drugs 0.000 description 4
- 229910000368 zinc sulfate Inorganic materials 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 229910001430 chromium ion Inorganic materials 0.000 description 3
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000004070 electrodeposition Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000005554 pickling Methods 0.000 description 3
- 238000007747 plating Methods 0.000 description 3
- 238000007788 roughening Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 238000005246 galvanizing Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000003449 preventive effect Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 2
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 230000009920 chelation Effects 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000007772 electroless plating Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000005077 polysulfide Substances 0.000 description 1
- 229920001021 polysulfide Polymers 0.000 description 1
- 150000008117 polysulfides Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 239000011550 stock solution Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 235000005074 zinc chloride Nutrition 0.000 description 1
- 239000011592 zinc chloride Substances 0.000 description 1
- GTLDTDOJJJZVBW-UHFFFAOYSA-N zinc cyanide Chemical compound [Zn+2].N#[C-].N#[C-] GTLDTDOJJJZVBW-UHFFFAOYSA-N 0.000 description 1
- OMSYGYSPFZQFFP-UHFFFAOYSA-J zinc pyrophosphate Chemical compound [Zn+2].[Zn+2].[O-]P([O-])(=O)OP([O-])([O-])=O OMSYGYSPFZQFFP-UHFFFAOYSA-J 0.000 description 1
Classifications
-
- 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
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/78—Pretreatment of the material to be coated
-
- 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
- H05K3/38—Improvement of the adhesion between the insulating substrate and the metal
- H05K3/382—Improvement of the adhesion between the insulating substrate and the metal by special treatment of the metal
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrochemical Coating By Surface Reaction (AREA)
- Electroplating Methods And Accessories (AREA)
- Chemical Treatment Of Metals (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
- Manufacturing Of Printed Wiring (AREA)
Description
本発明は、印刷回路用銅箔の製造方法に関する
ものであり、特には防錆特性を始めとして印刷回
路用銅箔として要求される様々の特性を改善した
印刷回路用銅箔の製造方法に関するものである。
印刷回路用銅箔は一般に樹脂基材に高温高圧下
で積層接着される。その後、目的にあつた回路を
形成するべくエツチング処理が施され、最終的に
所要の電気素子が半田付けされてテレビ、ラジオ
等の一般家電用の回路板あるいは電算機を含む各
種電子機器用の精密制御回路板が形成される。銅
箔の樹脂基材に接着される表面は接着目的のため
に粗化されておりそして積層回路板上で露呈され
る他面は平滑状態とされている。従つて、印刷回
路用銅箔には、以下に記載するような様々の特性
が要求される。
先ず、平滑な光沢面の側に要求される特性とし
ては、(1)外観がきれいであること、(2)防錆力が適
度にあり、美観を損わないこと、(3)積層接着時に
熱変色しないこと、(4)半田とよく濡れること等が
挙げられ、他方粗面の側に要求される特性として
は半田づけ前後の剥離強度が大きいことおよび防
錆力が適度にあることが特に重要である。更に、
銅箔全体として要求される特性としては(1)エツチ
ング速度が遅すぎたり、エツチング残を生じたり
またオーバーエツチングを生じることがないよう
適正なエツチング処理を行いうること、(2)比抵抗
が小さいこと等が主に挙げられる。このように、
印刷回路用銅箔には多様のしかも異質の特性が要
求され、しかも電子機器分野の進歩に伴い印刷回
路板に要求される品質は益々厳しいものとなつて
いる。
印刷回路用銅箔の特性を改善するための方法と
して従来から行われてきたものの一つとしてクロ
メート処理法がある。クロメート処理法は、六価
のクロムイオンを含む溶液中に銅箔を浸漬する等
して、銅箔表面に酸化クロム層を形成するもので
あり、剥離強度、耐食性等の面で銅箔の印刷回路
用特性をかなり改善する。
しかしながら、クロメート処理銅箔は高温多湿
時における防錆力が弱く、更に銅箔平滑面に対し
ては半田濡れ性および積層接着時の熱変色の点で
問題があり、また銅箔粗化面についてもその剥離
強度が現在要求される水準に不足している。クロ
メート処理銅箔は高温多湿環境では３日位で発銹
するから、処理ずみ銅箔に積層接着処理を施すま
での輸送や保管中に早くも発銹を生じ、そのため
剥離強度の低下やその後の加工処理に支障を与え
ることが多い。クロメート処理に当つて、浴中に
添加剤を加えたりまた他の被覆層の併用と云つた
試みも為されているが、まだ尚満足すべきものは
得られていない。
本発明者は、銅箔の平滑面側および粗面側それ
ぞれについて印刷回路用途に要求される特性をク
ロメート処理のみにより得られる場合より更に改
善するべく検討を重ねた。その結果、クロメート
処理前に亜鉛被膜層を形成しておくことが、銅箔
の平滑面側および粗面側のそれぞれについて、そ
の要求される特性が相異するにもかかわらず、等
しく有用であることを見出した。すなわち、銅箔
の平滑面に亜鉛およびクロム酸化物の２重被膜を
形成することにより、銅箔平滑面に要求される積
層接着時の熱変色および半田濡れ性は改善されそ
して防錆性も大巾に向上する。他方、銅箔の粗面
側に亜鉛およびクロム酸化物の２重被膜を形成す
ることにより、銅箔粗面側に要求される剥離強度
は改善されまた防錆効果により積層接着時までの
発銹防止が保証される。銅箔の平滑面側あるいは
粗面側に上記２重被膜形成処理を行つた場合、残
る側には、もちろん同じ亜鉛およびクロム酸化物
被膜を形成してもよいが、その残る面側に適した
従来から知られる化成処理、有機剤処理あるいは
金属被覆処理を施すことも可能である。用途に応
じて特別に要求される特性がある場合には、それ
に最適の処理を選択することができる。例えば、
半田濡れ性が強く必要とされる場合には、銅箔の
粗面側に亜鉛およびクロム酸化物２重被膜処理を
行いそして平滑面側にキレート有機剤による処理
を施してもよい。あるいは、特別な機械的処理あ
るいは電解処理により銅箔に粗面を形成して剥離
強度を改善することが知られているが、そのよう
な方法によつて粗面を形成した場合には、銅箔の
平滑面にのみ亜鉛およびクロム酸化物２重被覆処
理を施し、粗面はそのままとすることもできよ
う。
斯くして、本発明は、銅箔の粗面あるいは平滑
な光沢面のいずれか一方に亜鉛の被膜を形成し、
次いで亜鉛被膜の上にクロム酸化物の被膜を形成
することを特徴とする印刷回路用銅箔の製造方法
を提供する。
以下、本発明について詳しく説明する。
本発明の処理の対象とする銅箔は圧延銅箔ある
いは電解銅箔の片面を粗化処理したものである。
粗化処理は、樹脂基材に接着する面の積層後の剥
離強度を高めることを目的とするもので、銅箔の
表面に銅の突起状の電着層を形成するための所謂
焼き電着により行われるのが一般的である。粗化
処理に使用される電解液組成、電解条件、前処理
ならびに後処理等については様々なものが既に公
知されておりここでは説明を省略する。いずれに
せよ、こうして得られる銅箔は、一側において平
滑な光沢面をそして他側において凹凸のある粗面
を有している。
本発明に従えば、銅箔の平滑光沢面あるいは粗
面のいずれか一方に亜鉛被膜とクロム酸化物被膜
が被覆される。
亜鉛被膜の形成は、亜鉛電気めつきおよび無電
解めつきいずれでも行いうるが、片面にのみ被膜
を形成するためには亜鉛電解操作による方が便宜
である。また、厚さの精確な制御、厚さの一様
性、付着層の緻密化等の観点からも電解操作が好
ましい。亜鉛電解操作は、硫酸亜鉛めつき浴や塩
化亜鉛めつき浴に代表される酸性亜鉛めつき浴、
シアン化亜鉛めつき浴のようなアルカリ性亜鉛め
つき浴、あるいはピロリン酸亜鉛めつき浴が使用
しうるが、もつとも一般的に使用される硫酸亜鉛
浴で充分である。硫酸亜鉛浴を使用した場合の好
ましい亜鉛電解条件は下記の通りである。
The present invention relates to a method for producing copper foil for printed circuits, and in particular to a method for producing copper foil for printed circuits that improves various properties required of copper foil for printed circuits, including anti-corrosion properties. It is. Copper foil for printed circuits is generally laminated and bonded to a resin base material under high temperature and pressure. After that, an etching process is performed to form a circuit suitable for the purpose, and finally the necessary electrical elements are soldered to form a circuit board for general home appliances such as televisions and radios, or for various electronic devices including computers. A precision control circuit board is formed. The surface of the copper foil to be bonded to the resin substrate is roughened for bonding purposes, and the other surface exposed on the laminated circuit board is smooth. Therefore, copper foil for printed circuits is required to have various properties as described below. First of all, the characteristics required for the smooth, glossy side are (1) good appearance, (2) appropriate rust prevention ability that does not impair the aesthetics, and (3) no damage to the surface during lamination bonding. (4) good wettability with solder; on the other hand, characteristics required for the rough surface side include high peel strength before and after soldering, and moderate rust prevention ability. is important. Furthermore,
The characteristics required for the copper foil as a whole are (1) the ability to perform proper etching treatment so that the etching speed is too slow, etching residue does not occur, or overetching occurs, and (2) specific resistance is low. The main things that can be mentioned are: in this way,
Copper foils for printed circuits are required to have various and different characteristics, and the quality required for printed circuit boards is becoming increasingly strict as the electronic equipment field progresses. Chromate treatment is one of the conventional methods for improving the properties of copper foil for printed circuits. The chromate treatment method involves dipping the copper foil in a solution containing hexavalent chromium ions to form a chromium oxide layer on the surface of the copper foil. Significantly improves circuit characteristics. However, chromate-treated copper foil has weak rust prevention ability under high temperature and humidity conditions, and also has problems with solder wettability and thermal discoloration during lamination bonding on smooth copper foil surfaces. However, its peel strength is insufficient to the currently required level. Chromate-treated copper foil will rust in about 3 days in a high-temperature and humid environment, so rusting will occur even during transportation and storage before the laminated adhesive treatment is applied to the treated copper foil, resulting in a decrease in peel strength and subsequent damage. It often interferes with processing. In the chromate treatment, attempts have been made to add additives to the bath and to use other coating layers in combination, but nothing satisfactory has yet been achieved. The present inventor has conducted repeated studies to further improve the characteristics required for printed circuit applications on both the smooth side and the rough side of copper foil compared to those obtained by chromate treatment alone. As a result, forming a zinc coating layer before chromate treatment is equally useful for the smooth and rough sides of the copper foil, even though their required properties are different. I discovered that. In other words, by forming a double layer of zinc and chromium oxide on the smooth surface of copper foil, thermal discoloration and solder wettability during lamination bonding required for the smooth surface of copper foil are improved, and rust prevention is also improved. Improving dramatically. On the other hand, by forming a double coating of zinc and chromium oxide on the rough side of the copper foil, the peel strength required for the rough side of the copper foil is improved, and the rust prevention effect prevents rusting until lamination bonding. Prevention is guaranteed. When the above-mentioned double film formation treatment is performed on the smooth or rough side of the copper foil, the same zinc and chromium oxide film may of course be formed on the remaining side, but It is also possible to perform conventionally known chemical conversion treatment, organic agent treatment, or metal coating treatment. If there are special characteristics required depending on the application, the most suitable treatment can be selected. for example,
If solder wettability is strongly required, the rough side of the copper foil may be treated with a double layer of zinc and chromium oxide, and the smooth side may be treated with a chelating organic agent. Alternatively, it is known that special mechanical treatment or electrolytic treatment is used to form a rough surface on copper foil to improve peel strength. It would also be possible to apply the zinc and chromium oxide double coating only to the smooth side of the foil, leaving the rough side alone. Thus, the present invention forms a zinc coating on either the rough surface or the smooth glossy surface of the copper foil,
The present invention provides a method for producing copper foil for printed circuits, which comprises forming a chromium oxide film on the zinc film. The present invention will be explained in detail below. The copper foil to be treated in the present invention is a rolled copper foil or an electrolytic copper foil that has been roughened on one side.
The purpose of the roughening treatment is to increase the peel strength after lamination of the surface that will be bonded to the resin base material, and is a so-called baked electrodeposition process to form a protruding copper electrodeposition layer on the surface of the copper foil. This is generally done by Various electrolytic solution compositions, electrolytic conditions, pre-treatments, post-treatments, etc. used in the roughening treatment are already known and will not be described here. In any case, the copper foil thus obtained has a smooth, shiny surface on one side and an uneven, rough surface on the other side. According to the present invention, either the smooth glossy surface or the rough surface of the copper foil is coated with a zinc coating and a chromium oxide coating. The zinc coating can be formed by either zinc electroplating or electroless plating, but in order to form a coating only on one side, zinc electrolysis is more convenient. Electrolytic operation is also preferred from the viewpoint of precise control of thickness, uniformity of thickness, and densification of the deposited layer. Zinc electrolysis is performed using acidic zinc plating baths such as zinc sulfate plating baths and zinc chloride plating baths.
Alkaline galvanizing baths such as zinc cyanide baths or zinc pyrophosphate baths may be used, although the commonly used zinc sulfate baths are sufficient. Preferred zinc electrolysis conditions when using a zinc sulfate bath are as follows.
【表】【table】
【表】
電解条件は所望の亜鉛被覆厚さを得るよう選定
されるが、後述する理由のために、銅箔の平滑光
沢面側が処理される場合には亜鉛被覆量を30〜
250μｇ／ｄm2とすることが好ましく、他方粗面
側が処理される場合には15〜1500μｇ／ｄm2の亜
鉛被覆量とすることが好ましい。この場合、粗面
側における亜鉛被覆量は、積層時の樹脂基板の種
類によつて異なる。例えばフエノール樹脂基板用
は、15〜60μｇ／ｄm2とし、ガラスエポキシ樹脂
基板用は60〜1500μｇ／ｄm2とする。電解処理
は、銅箔シートをその処理すべき面を陽極に対面
させて電解槽内を連続的に通す等の方法で実施さ
れうる。処理すべき面が平滑光沢面か粗面かに応
じて、所望の電着量を得るべく、電流密度、銅箔
〜陽極面間距離、移動速度等が適宜調節される。
上記操作で片面に亜鉛被覆された銅箔はその亜
鉛被膜上にクロム酸化物被膜を形成される。この
操作は、周知のクロメート処理即ち六価のクロム
イオンを含む溶液中に亜鉛被覆銅箔を浸漬し、銅
箔表面の亜鉛と六価のクロムイオンとの酸化還元
反応により酸化クロム層を被覆することにより行
なう。浸漬法あるいは電解法いずれも使用しうる
が、亜鉛を被覆していない面へのクロム酸化物の
付着を防止する為に浸漬法の場合、非処理面に適
宜のカバーを付す必要があるため電解クロメート
処理が好ましい。クロメート処理液は現在使用さ
れている様々の処理液いずれも使用しうるが、好
ましいクロメート処理条件例を以下に示す。[Table] The electrolytic conditions are selected to obtain the desired zinc coating thickness, but for the reasons explained below, when the smooth shiny side of the copper foil is treated, the zinc coating amount is
Preferably, the zinc coating amount is 250 μg/dm 2 , whereas if the rough side is treated, a zinc coating amount of 15 to 1500 μg/dm 2 is preferred. In this case, the amount of zinc coating on the rough surface side varies depending on the type of resin substrate at the time of lamination. For example, for phenol resin substrates, the amount is 15 to 60 μg/dm 2 , and for glass epoxy resin substrates, it is 60 to 1500 μg/dm 2 . The electrolytic treatment can be carried out by a method such as continuously passing the copper foil sheet through an electrolytic cell with the surface to be treated facing the anode. Depending on whether the surface to be treated is a smooth glossy surface or a rough surface, the current density, the distance between the copper foil and the anode surface, the moving speed, etc. are adjusted as appropriate to obtain the desired amount of electrodeposition. In the above operation, the copper foil coated with zinc on one side has a chromium oxide coating formed on the zinc coating. This operation is a well-known chromate treatment, in which the zinc-coated copper foil is immersed in a solution containing hexavalent chromium ions, and a chromium oxide layer is coated by an oxidation-reduction reaction between the zinc on the surface of the copper foil and the hexavalent chromium ions. Do it by doing this. Both the immersion method and the electrolytic method can be used, but in the case of the immersion method, it is necessary to attach an appropriate cover to the untreated surface to prevent chromium oxide from adhering to the surface that is not coated with zinc. Chromate treatment is preferred. Although any of the various currently used chromate treatment solutions can be used, examples of preferred chromate treatment conditions are shown below.
【表】
鋼板
酸性が高すぎると、亜鉛の溶解度が大きいの
で、これを抑制して皮膜生成を容易にするべく硫
酸カルシウム等を添加してもよい。クロム酸化物
付着量はいずれの面が処理される場合でもクロム
量として50μｇ／ｄm2以下で充分であり、好まし
くは15〜30μｇ／ｄm2とされる。
前述した通り、本発明においては好ましくは、
粗面側に被膜が形成される場合、亜鉛被覆量を亜
鉛量で表わして15〜1500μｇ／ｄm2としそしてク
ロム酸化物量をクロム量として表わして15〜30μ
ｇ／ｄm2となし、他方平滑な光沢面側に被膜が形
成される場合、亜鉛被覆量を亜鉛量で表わして30
〜250μｇ／ｄm2としそしてクロム酸化物量をク
ロム量として表わして15〜30μｇ／ｄm2とする。
これは次のような理由による。
平滑な光沢面の側において、亜鉛被覆量が、30
μｇ／ｄm2以下であれば防錆力が劣り、250μ
ｇ／ｄm2以上であれば、銅箔の銅色が失われて外
観が劣り、比抵抗の点でも問題がある。またクロ
ム酸化物被膜中のクロム量が15μｇ／ｄm2以下で
あれば、防錆力が劣るとともに熱変色しやすくな
り、30μｇ／ｄm2以上であれば、エツチング性が
悪くなるとともに半田濡れ性も悪くなる。
一方粗面の側においては、フエノール樹脂基板
に積層した場合、亜鉛被覆量が15〜60μｇ／ｄm2
の範囲に剥離強度の最大値（2.2Kg／cm）が現わ
れ、またガラスエポキシ樹脂基板に積層した場合
には亜鉛被覆量が60〜1500μｇ／ｄm2の範囲に剥
離強度（半田付け後）の最大値（2.0〜2.2Kg／
cm）が現われる。また、クロム酸化物被膜中のク
ロム量が15μｇ／ｄm2以下であれば、フエノール
樹脂基板に対しては剥離強度が1.5Kg／cm以下と
なり、ガラスエポキシ樹脂基板に対してはフエノ
ール樹脂基板の場合ほど顕著でないが約0.2Kg／
cm低下する。またクロム量が30μｇ／ｄm2以上に
なれば防錆力は向上するがエツチング性が低下す
る。一般に防錆力と半田濡れ性とは互いに相反す
る傾向があり、防錆力を強化すれば、半田濡れ性
が悪化する。しかし本発明のように各被膜の被覆
量を上記値に設定することにより十分な防錆力を
有し、しかも比較的簡単な前処理（10％硫酸酸洗
及び／又はプリフラツクス、ポストフラツクス塗
布）のみで半田濡れ性の非常に良い銅箔の製造が
可能となる。
本発明における銅箔製造方法は、銅箔を水洗、
亜鉛めつき、水洗、クロメート処理、水洗、乾燥
の各ステージを順次連続的に通すことにより実施
される。銅箔表面に被覆された亜鉛は活性なもの
であり、水洗中およびクロメート処理中溶解しや
すいので、PH、液濃度等の浴管理を厳密にする必
要がある。
こうして片面を２重被膜処理された銅箔は、残
る面を必要に応じ別様に処理するかあるいは処理
することなく、粗面に接着剤を塗布して基板に加
熱圧着することにより印刷回路用銅貼フイルムと
され、所定の加工操作を経た後、印刷回路板とし
て使用に供される。本発明の処理を施されなかつ
た面の処理方法としては、クロメート処理を含む
各種化成処理、銅とのキレート化反応を利用した
有機剤処理、銅より卑な金属ないし合金の被覆処
理等その面において要求される特定水準に応じて
適当なものが選ばれよう。接着性のよい粗面が従
来法により既に形成されまた積層接着時までの防
錆を考慮する必要のない状況においては、本発明
に従い平滑光沢面に２重被膜処理を施した後その
まま積層接着工程にまわされる。
以下、実施例を示す。
実施例 １
あらかじめ片面に粗面化処理を施してある厚さ
35μの銅箔の平滑光沢面側に本発明に従う亜鉛お
よび酸化クロム２重被膜処理を施した。先ず、銅
箔の平滑光沢面に亜鉛被膜を形成するため、PH
3.5および浴温度50℃の、200g／のZnSO4・
7H2Oを含有する硫酸亜鉛溶液中に銅箔をその平
滑光沢面を亜鉛陽極に対面して浸漬し、0.15A／
ｄm2の電流密度で15秒間亜鉛電解を行つた。その
後、銅箔を水洗後、電解クロメート処理により亜
鉛被膜上にクロム酸化物被膜を形成した。電解ク
ロメート処理は次の浴組成および条件によつて実
施した。
浴組成：1g／のK2Cr2O7を含むりん酸溶液
PH：3.0
浴温度：30℃
浸漬時間：30秒
電流密度：0.3A／ｄm2
その後、銅箔を水洗および乾燥した。このよう
にして得られた処理ずみ銅箔の単位小片を切取
り、分析測定したところ、平滑光沢面における亜
鉛およびクロム酸化物の被覆量はそれぞれ150μ
ｇ／ｄm2および25μｇ／ｄm2であつた。
比較例 １
実施例１と同じ銅箔にその円滑光沢面において
電解クロメート処理により酸化クロム被膜のみを
形成した。被膜のクロム量は45μｇ／ｄm2とし
た。
以上のようにして得られた実施例１および比較
例１の生成銅箔をフエノール樹脂上に加熱圧着
し、平滑光沢面の各種特性を比較評価した。結果
を下表に示す：[Table] Steel Sheet If the acidity is too high, the solubility of zinc will be high, so calcium sulfate or the like may be added to suppress this and facilitate film formation. Regardless of which surface is treated, a chromium oxide deposit of 50 μg/dm 2 or less is sufficient, and preferably 15 to 30 μg/dm 2 . As mentioned above, in the present invention, preferably,
When a film is formed on the rough surface side, the amount of zinc coating expressed as zinc amount is 15 to 1500μg/ dm2 , and the amount of chromium oxide expressed as chromium amount is 15 to 30μg/dm2.
g/dm 2 , and when a film is formed on the smooth glossy side, the amount of zinc coating is expressed as the amount of zinc, and is 30
~250 μg/dm 2 and the amount of chromium oxide expressed as the amount of chromium is 15 to 30 μg/dm 2 .
This is due to the following reasons. On the smooth shiny side, the zinc coverage is 30
If it is less than μg/dm 2 , the rust prevention ability will be poor, and 250μ
If it is more than g/dm 2 , the copper color of the copper foil is lost, the appearance is poor, and there are also problems in terms of resistivity. Furthermore, if the amount of chromium in the chromium oxide film is less than 15 μg/dm 2 , the rust prevention ability will be poor and it will easily discolor due to heat, and if it is more than 30 μg/dm 2 , the etching property will be poor and the solder wettability will be poor. Deteriorate. On the other hand, on the rough surface side, when laminated on a phenolic resin substrate, the zinc coating amount is 15 to 60 μg/dm 2
The maximum peel strength (2.2 Kg/cm) appears in the range of Value (2.0~2.2Kg/
cm) will appear. Additionally, if the amount of chromium in the chromium oxide film is 15 μg/dm 2 or less, the peel strength will be 1.5 Kg/cm or less for a phenolic resin substrate, and for a phenolic resin substrate it will be less than 1.5 kg/cm for a glass epoxy resin substrate. Although it is not as noticeable as that, about 0.2Kg/
cm decreases. Furthermore, if the amount of chromium is 30 μg/dm 2 or more, the rust prevention ability will improve, but the etching property will decrease. Generally, rust preventive power and solder wettability tend to be contradictory to each other, and if the rust preventive power is strengthened, the solder wettability deteriorates. However, as in the present invention, by setting the coating amount of each coating to the above value, it has sufficient rust prevention ability, and also requires relatively simple pretreatment (10% sulfuric acid pickling and/or pre-flux, post-flux). Copper foil with very good solder wettability can be produced by simply applying the coating. The copper foil manufacturing method in the present invention includes washing the copper foil with water,
It is carried out by sequentially passing through the following stages: galvanizing, water washing, chromate treatment, water washing, and drying. Zinc coated on the copper foil surface is active and easily dissolves during water washing and chromate treatment, so it is necessary to strictly control the bath pH, liquid concentration, etc. Copper foil that has been double-coated on one side can be used for printed circuits by applying an adhesive to the rough surface and heat-pressing it to a substrate, either by treating the remaining surface differently as necessary or without any treatment. It is made into a copper-plated film, and after undergoing certain processing operations, it is used as a printed circuit board. Treatment methods for surfaces that have not been subjected to the treatment of the present invention include various chemical conversion treatments including chromate treatment, organic agent treatments using chelation reactions with copper, coating treatments with metals or alloys less base than copper, etc. An appropriate one will be selected depending on the specific level required. In situations where a rough surface with good adhesion has already been formed by the conventional method and there is no need to consider rust prevention before lamination bonding, the smooth glossy surface can be subjected to double coating treatment according to the present invention, and then the lamination bonding process can be carried out directly. be passed around. Examples are shown below. Example 1 Thickness with roughening treatment applied to one side in advance
A double coating of zinc and chromium oxide according to the present invention was applied to the smooth glossy side of a 35μ copper foil. First, in order to form a zinc coating on the smooth glossy surface of the copper foil, PH
3.5 and 200 g/ZnSO 4 at bath temperature 50 °C.
A copper foil was immersed in a zinc sulfate solution containing 7H 2 O with its smooth, shiny surface facing the zinc anode, and a current of 0.15A/
Zinc electrolysis was carried out at a current density of dm 2 for 15 seconds. Thereafter, after washing the copper foil with water, a chromium oxide film was formed on the zinc film by electrolytic chromate treatment. The electrolytic chromate treatment was carried out using the following bath composition and conditions. Bath composition: Phosphoric acid solution containing 1 g/K 2 Cr 2 O 7 PH: 3.0 Bath temperature: 30° C. Immersion time: 30 seconds Current density: 0.3 A/dm 2 The copper foil was then washed with water and dried. When a unit piece of the treated copper foil obtained in this way was cut out and analyzed, the coating amount of zinc and chromium oxide on the smooth glossy surface was 150 μm each.
g/dm 2 and 25 μg/dm 2 . Comparative Example 1 Only a chromium oxide film was formed on the smooth glossy surface of the same copper foil as in Example 1 by electrolytic chromate treatment. The amount of chromium in the coating was 45 μg/dm 2 . The copper foils of Example 1 and Comparative Example 1 obtained as described above were hot-pressed onto a phenolic resin, and various characteristics of the smooth and glossy surfaces were comparatively evaluated. The results are shown in the table below:
【表】
尚表における各評価事項は次の方法条件の下で
試験されたものである：
防錆力
(A) 温度40℃、湿度80〜100％の雰囲気下で表面
を観察
(B) 10％多硫化アンモニア中に浸漬し変色するま
での腐食時間を測定
熱変色
温度160℃の熱オーブン中に15分間静置し表面
の焼け状態を観察
エツチング
38％の塩化第２鉄原液に浸漬
半田濡れ性
銅箔と半田との接触角を市販のソルダグラムに
より測定
前処理(A) 酸洗、乾燥後プリフラツクス塗布
(B) プリフラツクス塗布後、ポストフラ
ツクス塗布
(C) 酸洗、機械研磨、水洗、乾燥後プリ
フラツクス塗布
上表から印刷回路用銅箔の平滑光沢面において
要求される防錆性、耐熱変色性および半田濡れ性
がいずれも改善されていることがわかる。
実施例 ２
実施例１とは逆に銅箔の粗面側に実施例１と同
様にして亜鉛および酸化クロム被膜形成処理を施
した。但し、被膜の厚さは、フエノール樹脂基板
用として亜鉛が20μｇ／ｄm2そしてクロムが25μ
ｇ／ｄm2、また、ガラスエポキシ樹脂基板用とし
て、亜鉛が360μｇ／ｄm2、そしてクロムが30μ
ｇ／ｄm2となるよう条件を設定した。
比較例 ２
実施例２と同じく銅箔の粗面側にのみ酸化クロ
ム被膜を電解クロメート法により形成した。被覆
量はクロム45μｇ／ｄm2とした。
実施例２及び比較例２によつて生成された銅箔
をフエノール樹脂基板およびガラスエポキシ樹脂
基板に加熱圧着した後剥離強度を測定した。結果
は以下の通りである：[Table] Each evaluation item in the table was tested under the following method conditions: Rust prevention power (A) Observation of the surface in an atmosphere with a temperature of 40℃ and a humidity of 80 to 100% (B) 10 % immersion in ammonia polysulfide to measure the corrosion time until discoloration Heat discoloration Leave to stand in a hot oven at a temperature of 160°C for 15 minutes and observe the burnt state of the surface Etching Immerse in 38% ferric chloride stock solution for solder wetting Measurement of the contact angle between copper foil and solder using a commercially available soldergram Pretreatment (A) Pickling, drying, then preflux application (B) Preflux application, then postflux application (C) Pickling, mechanical polishing, water washing , Preflux application after drying From the above table, it can be seen that the rust prevention, heat discoloration resistance, and solder wettability required for the smooth glossy surface of copper foil for printed circuits are all improved. Example 2 Contrary to Example 1, zinc and chromium oxide coatings were formed on the rough side of the copper foil in the same manner as in Example 1. However, the film thickness is 20μg/ dm2 for zinc and 25μg/dm2 for chromium for phenolic resin substrates.
g/dm 2 , and for glass epoxy resin substrates, zinc is 360μg/dm 2 and chromium is 30μg/dm 2 .
The conditions were set so that it was g/dm 2 . Comparative Example 2 As in Example 2, a chromium oxide film was formed only on the rough side of the copper foil by electrolytic chromate method. The coating amount was 45 μg/dm 2 of chromium. The copper foils produced in Example 2 and Comparative Example 2 were bonded under heat and pressure to a phenolic resin substrate and a glass epoxy resin substrate, and then their peel strengths were measured. The results are as follows:
【表】
以上説明した通り、本発明は、印刷回路用銅箔
の平滑光沢面あるいは粗面いずれに適用するにせ
よ、その面において固有に要求される特性を改善
するので、印刷回路用銅箔製造方法として斯界に
寄与するところは大きい。[Table] As explained above, regardless of whether the present invention is applied to a smooth glossy surface or a rough surface of a copper foil for printed circuits, it improves the properties uniquely required for that surface. It has made a great contribution to this industry as a manufacturing method.
Claims (1)
一方に亜鉛の被膜を形成し、次いで亜鉛被膜の上
にクロム酸化物の被膜を形成することを特徴とす
る印刷回路用銅箔の製造方法。 ２ 粗面側に被膜が形成される場合、亜鉛被覆量
を亜鉛量で表わして15〜1500μｇ／ｄm2としそし
てクロム酸化物量をクロム量として表わして15〜
30μｇ／ｄm2とする特許請求の範囲第１項記載の
方法。 ３ 平滑な光沢面側に被膜が形成される場合、亜
鉛被覆量を亜鉛量で表わして30〜250μｇ／ｄm2
としそしてクロム酸化物量をクロム量として表わ
して15〜30μｇ／ｄm2とする特許請求の範囲第１
項記載の方法。[Claims] 1. A printed circuit characterized in that a zinc coating is formed on either the rough surface or the smooth glossy surface of a copper foil, and then a chromium oxide coating is formed on the zinc coating. A method for producing copper foil for use. 2 When a coating is formed on the rough surface side, the amount of zinc coating expressed as zinc amount is 15 to 1500 μg/ dm2 , and the amount of chromium oxide is expressed as chromium amount of 15 to 1500 μg/dm2.
The method according to claim 1, wherein the amount is 30 μg/dm 2 . 3 When a film is formed on a smooth glossy surface, the amount of zinc coating expressed in terms of zinc amount is 30 to 250 μg/dm 2
and the amount of chromium oxide expressed as the amount of chromium is 15 to 30 μg/dm 2
The method described in section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16410979A JPS5687676A (en) | 1979-12-19 | 1979-12-19 | Production of copper foil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16410979A JPS5687676A (en) | 1979-12-19 | 1979-12-19 | Production of copper foil |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21235592A Division JPH05275817A (en) | 1992-07-17 | 1992-07-17 | Manufacture of copper foil |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5687676A JPS5687676A (en) | 1981-07-16 |
| JPS6133907B2 true JPS6133907B2 (en) | 1986-08-05 |
Family
ID=15786917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16410979A Granted JPS5687676A (en) | 1979-12-19 | 1979-12-19 | Production of copper foil |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5687676A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014208893A (en) * | 2013-03-28 | 2014-11-06 | 古河電気工業株式会社 | Surface-treated copper foil, method of treating surface of the copper foil, copper-clad laminate sheet and method of producing the laminate sheet |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3768104B2 (en) * | 2001-01-22 | 2006-04-19 | ソニーケミカル株式会社 | Flexible printed circuit board |
| WO2012173178A1 (en) | 2011-06-14 | 2012-12-20 | 大日本印刷株式会社 | Conductive base for forming wiring pattern of collector sheet for solar cells, and method for producing collector sheet for solar cells |
| JP5919656B2 (en) * | 2011-06-14 | 2016-05-18 | 大日本印刷株式会社 | Conductive substrate for wiring pattern formation of current collector sheet for solar cell |
-
1979
- 1979-12-19 JP JP16410979A patent/JPS5687676A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014208893A (en) * | 2013-03-28 | 2014-11-06 | 古河電気工業株式会社 | Surface-treated copper foil, method of treating surface of the copper foil, copper-clad laminate sheet and method of producing the laminate sheet |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5687676A (en) | 1981-07-16 |
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