TWI267560B - Method of manufacturing surface-treated copper foil for PCB having fine-circuit pattern and surface-treated copper foil thereof - Google Patents

Abstract

To provide a method for manufacturing copper foil having excellent strength of adhesion to a substrate and heat resistance strength. The method for manufacturing the surface treated copper foil for a microfabrication circuit substrate suitable for production of the substrate having a microfabrication circuit pattern comprises steps of; arranging the copper foil as a cathode in an electroplating bath including Co, Ni, ammonium salt, and citric acid and precipitating and forming a roughening treatment layer of a Co-Ni alloy on the copper foil surface in such a manner that its surface roughness attains <= 0.5 mum; forming a pure Zn or Zn alloy coating layer on the roughening treatment layer; forming an electrolytic chromate layer on the coating layer; and forming a silane coupling agent treatment layer on the electrolytic chromate layer. The manufactured surface treated copper foil is excellent overall in the requirement characteristics as the copper foil, such as the strength of adhesion to the substrate, heat resistant strength of adhesion, chemical resistance, and etching, and is particularly suitable as the copper foil for the microfabrication circuit substrate.

Description

[Technical Field] The present invention relates to a surface-treated copper foil for a printed circuit board, and more particularly to a substrate suitable for manufacturing a fine circuit pattern having a line width of 20//m or less. Method for producing surface-treated copper foil for fine circuit board 0 [Prior Art] Conventionally, the surface-treated copper foil is widely used as a base material for printed circuit boards in the motor and electronics industries. Usually, the surface-treated copper foil is formed into a copper-clad laminate by hot press forming and a polymer-insulating substrate such as a glass-epoxy base material, a phenol resin substrate, or a polyimide, and is used for printing. In the manufacture of circuit boards. The most basic characteristic required for such a copper foil is that it has an excellent bonding strength between the copper foil and the insulating substrate. In particular, the copper foil is not only heated and pressurized with the insulating base substrate, but immediately after the completion of the lamination, the subsequent strength must be maintained above the desired characteristics even after various treatments in the subsequent post-treatment process. Therefore, it is necessary to have excellent chemical resistance, heat resistance, and the like for an acid, a base, or the like. Further, in the process of forming a copper circuit pattern and forming a wiring board, it is necessary to require an excellent etching property such that the etching residue does not remain in the non-pattern portion. In order to improve the adhesion strength of the copper foil, it is usually carried out by depositing fine copper particles and so-called roughening treatment of the steel V from the surface to make the surface of the copper foil surface. There is no m ^ &quot; , and 'only simple roughening treatment, even if it can improve the connection 1267560: 1 ' can not prevent the subsequent strength deterioration due to various chemicals and heat king / θ in the subsequent process. In order to overcome this problem, various post-treatment processes such as forming a zinc layer coating, forming an electrolytic chromate layer, and a rust-preventing treatment layer of the Shih-Shou Oo-Sword processing layer are formed in the above-mentioned roughening. On the other hand, there is a recent increase in the density and high performance of electronic components, and the use of a substrate circuit is also high. Therefore, it is necessary to obtain a slight line width. Therefore, the printed circuit base (4) copper pigs also need to have a fineness of a pattern suitable for such a fine line width. When the thickness of the roughened layer is fine, not only the strength of the surface of the copper foil is deteriorated, but the various characteristics required for the copper foil are also difficult to achieve, and there are dilemmas. Therefore, various studies have been conducted in order to have various characteristics required for fine grain thickness on the one hand and copper drop on the other hand. For example, there are: cu_n system (Japanese/patent special opening 52.145769 and special opening (four) death number), system (Japanese patent 4 inch open Zhao 58_028893, special Kaiping 2-2 like 9&lt; number), Cu-c A technique for forming an alloy roughening layer of a bismuth-Ni system (Japanese Patent Laid-Open Publication No. 02-292894). However, although the conventional technique disclosed above can be subjected to fine roughening treatment, since C is used as the main material of the alloy, only the above-mentioned characteristics required for mi as a printed circuit board are partially made. Improvements have not been made to improve the characteristics of chemical resistance, heat resistance and surnames such as acid resistance and durability, etc., and i, in order to comprehensively improve the above-mentioned required characteristics, additional plating is required. The present invention is intended to provide a fine thickness suitable for a fine circuit substrate and can be comprehensively improved. A method of producing a surface-treated copper foil for a fine circuit board which is a characteristic of a printed circuit board. The method for producing a surface-treated steel 4 for a fine circuit board according to the present invention is characterized by comprising the following Step: Disposing a copper foil on a cathode in an electroplating bath containing Co, Ni, an ammonium salt, and a citrate to reduce the surface roughness to 〇·5 # m or less Forming a roughened layer of a C〇-Ni alloy on the copper/white surface; forming a pure Zn or Zn alloy coating layer on the roughened layer; forming an electrolytic chromate layer on the film layer; Forming a decane coupling agent treatment layer on the chromate layer. The above electroplating bath contains C〇: 1~4〇g/i, Ni: 〇·1~40g/l, and money salt 5~5 0g/l, screwed 5. The citric acid is preferably 5 to 1 〇〇 g /: 1. Further, the electroplating bath further contains Fe, Zn, Cr,

One or more of Mo, W, V, Mn, Ti, and Sn are formed to form Co, Ni, and additional components, which are selected from Fe, Zn, and Cr.

A roughening layer composed of one or more of Mo W, V, Mil, Ti, and Sii is preferred. The present invention will be described in detail below. The present invention can be applied to any type of copper foil such as electrolytic copper foil or rolled copper foil, and is applicable to all rigid and flexible printed circuit boards. In particular, according to the manufacturing method of the present invention, all of the required characteristics of the steel box can be satisfied, and 1267560 can achieve fineness, so that it can be preferably used for copper foil lamination of a so-called flexible printed circuit board which requires a fine line width. For the production of film (FCCL), 0 is a copper foil for FCCL, and at least a roughening layer having a thickness of 〇·5 # m or less is required. However, when the thickness is low, the strength and chemical resistance are followed. The required characteristics such as heat resistance and etching property are deteriorated, which is a problem. The main characteristics of 乂+3⁄4 months are different from those of the conventional ones. The roughening treatment layer is required to contain a nickel-cobalt alloy as a main component, so that the characteristics of such a nickel-based alloy can be maximized. The salt and citric acid, which are the vehicles of the electrolysis reaction, are added to the electric ore bath to carry out the electric clock. In this case, the fineness can be formed and the coarsening treatment layer can be satisfied. Nickel, which has various properties required for white, can improve chemical resistance and heat resistance. However, in the case where zinc is used to form a roughened layer separately, it is necessary to precipitate fineness = the residue will occur when the money is examined. Is the disadvantage = θ is difficult' point is that it can be precipitated in fine thickness, and the surname is good. If the recording is reversed, the roughening treatment layer is formed, and the order is to be resistant. At the same time add force = is its problem. When we meet all the required characteristics, we can see that it is expected that it can be the same as nickel and cobalt as the main _ _ _ _ _ _ _ 'actually into the desired fine roughening sound, not only can not Shape, chemical resistance and money, etc. also have 'expected improvement, and then the inventors, etc.' For the results of these back-force studies, found: 1267560 If adding ammonium salt and lemon The acid salt can maximize the effect of nickel and cobalt. It can form a roughened layer with fineness which is significantly improved in various characteristics. I believe that the ammonium salt will participate in the electrolysis of the reaction path between nickel and cobalt. The nickel-cobalt alloy is precipitated in the form of a finer ball, and the ball is uniformly precipitated in the form of a ball. The type of the applicable ammonium salt is not particularly limited, and for example, sulfuric acid can be used. Ammonium, ammonium chloride, ammonium, etc. Further, the 'citric acid system functions as a complex to form an ampoule with an ammonium salt and a metal ion of nickel and cobalt to improve heat resistance. # nucleic acid as a reaction between nickel-gu and ammonium salts The agent has a particularly good function, and contributes to the action of firmly binding the nickel-cobalt ball formed by the ammonium salt to the copper foil. As a suitable citric acid in the present invention, the acid is Sodium, potassium citrate, ammonium citrate, diammonium citrate, citrate iron ~ 巫 珂仗 珂仗 蚀刻 etch and chemical resistance further increase the physical properties or mechanical properties of the copper box For the purpose of adding or improving the peeling strength of the bright substrate and the copper foil, it is possible to additionally add components other than Fe, Zn, Cr, Mo, W, V, Mn, Ti, and Sn to the surface of Co and Ni. In the electroplating bath, for example, if Fe and Zn are contained in the blackened plating layer, the adhesion strength to the PET substrate can be improved, and the etching degree is faster, which is an advantage. The coin is used to form the roughening according to the present invention. The composition of the preferred plating bath that can be used for the treatment layer is as follows, but is not particularly limited thereto. It is 1267560

Co metal ion concentration··

Ni metal ion concentration··0.1~40g/l Other metal ion concentration··0.001~5g/l Ammonium salt·· 5~50g/l

Sodium citrate (C6H5Na3〇7·2h2〇): 5~1〇〇g/I If the roughening layer is formed by the plating bath of the above composition, the roughened layer is an advantage. More: The roughening treatment layer of the electric money bath. It is:

Furthermore, the electrolysis conditions can be electrolyzed near the current density at which the rough layer boundary can be formed.

From the point of view of the consideration, the ratio is much better than L | VA. The following range is good pH ·· 2~6 Plating solution temperature: 20~60°C 黾流度度··1~5 0A/dm2 Processing time: 1 The ~2 〇 second knife forms a pure Ζ or 211 ❹ ❹ 理 理 / gold coating layer. As a soluble Ζη alloy, there are:

:, Z-n-Cr, Zn-C〇, Zn_Ni, ^^^ Temple. The film formation condition can be selected by generally using (4) conditions. For example, a preferred effect can be obtained by using the following conditions. i Other metal ions: l〇g/l or less electrolytic bath composition: Zn metal ion: PH: 3.0~4.0 Temperature: normal temperature 10 1267560 Current density · · 0.1~3A/dm2 Processing time: 1~4 seconds into the tenth The old μ can be formed by forming a common copper plate for preventing circuit boards, such as an electrolytic chromate layer and an alkane coupling agent treatment layer. In the first layer, the fine (tetra) salt treatment condition 'is according to the present invention can be selected and used in accordance with usual processing conditions. For example, the following conditions can be used as the right, and it is particularly limited thereto. (4) The best effect, however, is not the Cr〇3 concentration of the electrolytic bath··1~1〇g/1 pH of the electrolyte: 4.0~5«〇 electrolyte temperature·normal temperature current density: 0.2~2A/dm2 Processing time: 2~5 seconds can be formed by drying thin chrome hydroxide and chromium by weight chopping

If the chromate treatment is carried out, the anti-rust layer composed of the oxide is treated with a decane coupling agent. For example, the 〇 5 5 coupling agent can be diluted into water and applied to the chromate layer. [Embodiment] (Example 1) A rolled copper crucible having a surface roughness (RZ) of U... and a thickness of m was used. The surface of the copper junction was subjected to electrolytic alkaline degreasing, and was immersed in sulfuric acid for H), and then washed with pure water to form a roughened condition under the following conditions. 11 I267560

<Colding treatment layer formation conditions> The conditions disclosed below were followed by [the sensation coupling agent treatment. Electrolytic bath composition:

Co metal ion (C〇s〇4 · 7H20) concentration: 5g / l, Ni metal ion (NiS 〇 4 · 6H2 〇) concentration: 2g / sodium citrate (C6H5Na307 · 2h2 〇): 25g / b ammonium sulfate ( (NH4)2S04) : 15g/l PH : 5.4 Electrolyte temperature: 25°C Current density: 25A/dm2 Plating time: 8 seconds &lt;Ζη Film formation conditions〉

ZnS04 . h2〇 : 5g/l PH : 3.0 Temperature: normal temperature Current density: 1 A/dm2 Treatment time 4 seconds &lt;Chromate anti-rust treatment conditions&gt;

Cr03 concentration: 5g/i pH : 5.0 Temperature: normal temperature current density: 0.5A/dm2 treatment time: 4 seconds &lt; simmering coupling agent treatment conditions > 12 1267560 After performing chromate rust treatment, 3-epoxy An aqueous solution of propoxypropyltrimethoxydecane 0.1% by weight was applied by spraying, and then dried in a drying oven at 150 ° C for 30 seconds. (Example 2) In addition to the conditions for forming the roughened layer disclosed below, the type of steel foil to be used, the pretreatment conditions such as degreasing, pickling, and water washing, and other surface treatment conditions (formation of Zn film layer, chromium) The acid salt treatment and the decane coupling agent treatment conditions were the same as in Example 1. &lt;Roughening treatment layer formation conditions&gt; Electrolysis bath composition:

Co metal #子(CoS04 · 7H20) concentration: 6g / l, Ni metal ion (NiS 〇 4 · 6H20) concentration: 〇. 5g /; l, sodium citrate (C6H5Na3 〇 7 · 2H2 〇): 25g / l, Ammonium sulphate ((NH4)2S04): 15g/l PH : 5.4 Temperature of electrolyte: 25 ° C Current density · 20 A/dm 2 Plating time: 10 seconds (Example 3) In addition to the coarsening disclosed below In addition to the treatment layer formation conditions, the pretreatment conditions such as the seed m and the rinsing, and the surface treatment conditions (the Zn coating layer formation, the chromate treatment, and the bismuth treatment conditions) were the same as in the first embodiment. 13 1267560 &lt;Roughening treatment layer formation conditions> Electrolytic bath composition:

Co metal ion (CoS04 · 7H2 〇) concentration: 6g / l, Ni metal ion (NlS04 · 6H20) concentration: lg /; l, sodium citrate (C6H5Na307 · 2H2 〇): 25g / l, ammonium sulfate ((NH4) 2S04) ·· I5g/1 PH : 5.4 Temperature of electrolyte: 25 ° C Current density: 22 A/dm 2 Plating time: 10 seconds (Example 4) In addition to the conditions for forming the roughened layer disclosed below, The type of copper foil to be used, the pretreatment conditions such as degreasing, pickling, and water washing, and other surface treatment conditions (formation of Zn coating layer, chromate treatment, and treatment conditions of decane coupling agent) are the same as in the first embodiment. &lt;Roughening treatment layer formation conditions> Electrolysis bath composition:

Co metal ion (C0SO4 · 71^0) concentration: 5g / dip metal ion (NiS 〇 4. 6H20) concentration. 2g / l, Fe metal ion (FeS 〇 4 · 7H2 〇) wave · lg / 1, lemon Sodium (C6H5Na307 · 2H2〇): 25g/l, ammonium sulfate ((NH4)2S〇4): 15g/l PH : 5.4 Temperature of electrolyte: 25°C Current density: 25A/dm2 14 1267560 Plating time: 8 seconds (Example 5) In addition to the conditions for forming the roughened layer disclosed below, the type of copper v| used, the pretreatment conditions such as degreasing, pickling, and water washing, and other surface treatment conditions (Ζιι film layer) The formation, chromate treatment, and decane coupling agent treatment conditions were the same as in Example 1. &lt;Roughening treatment layer formation conditions&gt; Electrolysis bath composition:

Co metal ion (C〇S04 · 7H20) concentration: 5g /; l, Ni metal ion (NiS04 · 6H20) concentration: 2g / l, Zn metal ion (ZnS 〇 4 · h2 〇) concentration: lg / 1, citric acid Sodium (C6H5Na307 · 2H2〇): 25g/l, ammonium sulfate ((NH4)2S04): 15g/l PH : 5.4 Electrolyte temperature: 25°C Current density: 25A/dm2 Plating time: 8 seconds (Comparative example) 1) The surface treatment was carried out in the same manner as in Example 1 except that the ammonium sulfate was not contained in the plating bath in the conditions for forming the roughened layer of Example 1. (Comparative Example 2) 15 1267560 In addition to the examples! The roughening treatment layer is not winter. This is for the private κ 丨丨々, electric 趟 bath, 彳 = ' 纳 纳 纳 纳 纳 纳 纳 纳 纳 纳 纳 纳 纳 纳 纳 纳 纳 ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( In the layer formation conditions, the surface treatment was carried out in the same manner as in Example ' except for the conditions other than 3 N in the plating bath. (Comparative Example 4) Except that the conditions for forming the roughened layer of Example 1 were such that Co was not contained in the electrocalation bath, the other conditions were carried out in the same manner as in Example 表, and the examples and comparisons were carried out. EXAMPLES The results of comparison of various desired characteristics were measured under the following test conditions. [Table 1]

Characteristic test results Next strength (Kgf/cm) Heat resistance strength (Kgf/cm) HC1 resistance KCN resistance Boiling resistance Alkali etching property Example 5 9 0. % 6 9 0. 1 73 0. 75 0. 1.74 ο

74 0.I 76 0.i 〇 〇 〇 〇 〇 〇 〇 〇

P

P Comparative Example 8 6 0. 5 8 a 5 8 0. 76 0. 9 0.41 0.57 2 5 0. 0. 〇

X 〇 〇 〇 〇 〇0〇

X

000〇〇/X D

X X

Xi 16 1267560 Quality test conditions Next strength: The epoxy resin impregnated substrate and the non-smooth surface of the copper foil are laminated to form a laminate, and the test piece is made to have a width of 10 mm, and the strength tester (Universal Test) is used. Macliine: UTM) was measured. Heat resistant strength: at 177. (: Dry baking oven (Dry〇ven) was baked for 24 hours, and the subsequent strength was measured. Resistance to Ηα: After immersion in 18% KC1 for 1 hour, the subsequent strength deterioration rate was measured. Boiling resistance (Loss in After boling in water): After immersing in H 〇 for 2 hours, the rate of deterioration of the strength was measured. <Evaluation criteria for HC1 resistance, KCN resistance, and boiling resistance> 〇: Deterioration before and after immersion The rate is 5 % or less △ ·· The deterioration rate before and after immersion is 5% to 25% or less x · The deterioration rate before and after immersion is 2 5 〇 / 〇 or more. · 于 · · · · · · 2. In the residual liquid of the specific gravity of 119 to 121, after being immersed for 8 minutes at a temperature of 50 ° C, the residual copper remaining on the substrate in the range of 1 〇 dm 2 was observed by an optical microscope. Etching evaluation standard> After etching, there is no residual copper or alloy layer remaining on the substrate. △ • After etching, there are some residual residual copper or alloy layers on the substrate. X: After etching, at the base There are many copper or alloy layers remaining on the material. As shown in the above table, it can be seen that in the case of the embodiment of the present invention, the strength and resistance are followed. It is excellent in chemical resistance, boilability, and alkali etching property, such as heat (heat-resistance strength) and potassium cyanide resistance. 17 1267560 In contrast, the method of removing the method according to the present invention from 4 to W is used. The comparative example of one or more of the necessary constituent elements of the chemical treatment layer is combined with 乂w, and at least one of the above characteristics is inferior to the embodiment of the present invention, for example, in terms of adhesion strength and thermal strength. According to the present invention, the yoke example is substantially increased by 9.6 % or more and 21 9% or more as compared with the comparative example. The effect of the invention is as described above, and is produced by the production method of the present invention. surface

The copper can be excellent as a copper foil for a fine circuit substrate, because it is excellent in the properties required for the copper foil, such as the adhesive strength of the substrate, the heat-resistant adhesive strength, the chemical resistance, and the etching property.儿 [Simple diagram description] None [Main component symbol description]

18

Claims (1)

1267560 Announcement, X. Patent application scope: h A method for manufacturing a surface-treated copper drop for a fine circuit substrate, characterized in that the R human body comprises the following steps: combining Co, Ni, ammonium salt and lemon In the electroplating bath of the acid salt, the copper foil is disposed on the cathode, and the surface roughness is 0.5//m or less, and the roughened layer of the Co-Ni alloy is formed on the surface of the copper crucible; A pure Zn or Zn alloy coating layer is formed on the roughening treatment layer; an electrolytic chromate layer is formed on the &quot;Hai film layer; and a decane coupling agent treatment layer is formed on the 4 complex acid layer. 2. The method of surface-treating copper enamel, raw + coating k for a fine circuit substrate according to claim 1, wherein the plating bath contains C 〇: 1 to 4 〇 g / 卜 Ni : 〜4 〇 g The method for producing a surface-treated copper foil for a fine circuit substrate according to the first aspect of the invention, wherein the electroplating bath further comprises a method selected from the group consisting of: 5 to 50 g of an ammonium salt; One or more of Fe, Zn, Cr, Mo, w, V, Μη, Ti, and Sri to form Co, Ni containing an essential component and containing additional components selected from Fe, Zn, Cr, Mo, w, One of V, Μη, Ti, and Sn is a roughened layer composed of a composition of μ, and aa t 扪 or more. 4. A surface-treated copper foil for a fine circuit substrate, the complex r~ is to be hunted by any one of the first to third aspects of the patent application. , the method of manufacturing XI, schema: