JPS5933185B2 - chemical copper plating liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chemical copper plating solution, and particularly to a chemical copper plating solution capable of providing a matted film with excellent mechanical properties.

Chemical copper plating solutions typically include copper salts such as copper sulfate and cupric chloride, ethylenediaminetetraacetic acid, N, N, N, N'-
It contains a complexing agent such as tetrakis-(2-hydroxypropyl) monoethylenediamine, a reducing agent such as formaldehyde, and a pH adjuster such as sodium hydroxide, but is obtained from a chemical copper plating solution consisting only of these. Plating films are generally brittle and lack mechanical properties, especially spreadability, for practical use.

For example, in the production of so-called additive printed wiring boards in which the conductive circuit portion of the printed wiring board is formed by chemical copper plating, thermal stress and physical shock due to processing of the printed wiring board and environmental changes occur. Easy to cause circuit breakage. In order to improve the above drawbacks, by further adding dipyridyls, phenanthrolines, or water-soluble cyanide compounds to a chemical copper plating solution consisting of a copper salt, a complexing agent, a reducing agent, and a pH adjuster, Attempts have been made to improve the spreadability of chemical copper plating films. However, even with the addition of the dipyridyls mentioned above, the spreadability of the chemical copper plating film is only slightly improved, and the mechanical properties are insufficient for practical use as a copper film that forms conductive circuits on printed wiring boards, for example. It is still not possible to obtain a plated film having . The present invention takes these points into consideration and aims to provide a chemical copper plating solution that provides a matted film with excellent mechanical properties, especially spreadability. A feature of the present invention is that a chemical copper plating solution containing a copper salt, a complexing agent, a reducing agent, and a pH adjusting agent, or a chemical copper plating solution containing a copper salt, a complexing agent, a reducing agent, and a pH adjusting agent, or 2,2'-dipyridyl In particular, a nonionic surfactant consisting of a polyoxyethylene derivative of a phenol resin is added to a chemical copper plating solution containing one or more of the following: 1,10 phenanthroline or its derivative, and a water-soluble cyanide compound. It is a combination.

In the present invention, the chemical copper plating solution based on a copper salt, a complexing agent, a reducing agent, and a PH adjuster, to which a nonionic surfactant based on a polyoxyethylene derivative of a phenol resin is added, has the following composition, for example. be.

The chemical copper plating solution that is the basis of the present invention may be a four-component system consisting of a copper salt, a complexing agent, a reducing agent, and a PH adjuster as described above, but it may also include 2,2'-dipyridyl or its derivatives, 1
, 10-phenanthrylone or a derivative thereof, a water-soluble cyanide compound, etc. may be further added and blended.
Examples of the water-soluble cyanide compounds include sodium cyanide, potassium cyanide, sodium nitroprusside, potassium nickel cyanide, potassium ferrocyanide, potassium ferricyanide, etc. The amount of these added is 2W19 to 39/l, preferably 0. 5W
Approximately 19 to 19 is good.

In the present invention, the nonionic surfactant made of a polyoxyethylene derivative of phenolic resin that is particularly added to the chemical copper plating solution is, for example, a polycondensate of a phenol derivative and formalin, a co-condensate of a phenol derivative and furfuryl alcohol, etc. , by subjecting the phenolic hydroxyl group of a polyalkylene polyphenol condensate or the like to an appropriate etherification reaction with ethylene glycol or polyoxyethylene glycol. However, such a nonionic surfactant has the following general formula (where R, , R
2 is a hydrogen atom, an alkyl group, a cycloalkyl group, an allyl group, an aralkyl group, 1, m, and n are integers of 1 or more)
This is shown in .

However, these nonionic surfactants may be used alone or in a mixed system of two or more, and the addition amount thereof is about 0.1 to 2.09 per 11 parts of the chemical copper plating solution. Next, the present invention will be explained using specific examples. Copper sulfate (pentahydrate), ethylenediaminetetraacetic acid, formaldehyde,
A nonionic surfactant consisting of sodium hydroxide, 2,2'-dipyridyl, 2-9-dimethyl 1,10-phenanthrone, sodium cyanide, and a polyoxyethylene derivative of a phenol resin was dissolved in water.
EXAMPLE 1 Fourteen types of chemical copper plating solutions having the compositions shown in 1 were prepared.

In addition, the surfactant is expressed by the following formula (where Rl and R2 are nonyl groups, and l is a number from 1 to 3), where m+n=3 is type (A), m+n=20 is type (B), and m+n-9. The case is indicated by type (O).

On the other hand, a rolled copper foil with a thickness of 10 μm was immersed in a 10% caustic soda aqueous solution for 30 seconds and then washed with water, followed by 100! ) The surface was cleaned by immersing it in a nitric acid aqueous solution and then washing it with water.

The surface-cleaned copper foil was immersed for 2 minutes in a pretreatment solution consisting of 509 tin chloride/l and 10 d/l hydrochloric acid, the balance being water, and then rinsed with running water for 1 minute.

After that, this pretreated copper foil was treated with palladium chloride 0.2
The sample was immersed for 1 minute in a sensitizing solution consisting of 10 ml of 59/11 hydrochloric acid and the balance of 1/11 was water, and washed in running water for 1 minute. The copper foils subjected to the above treatment were immersed in the chemical copper plating solution prepared above (bath temperature 70°C), and both sides of the copper foils were coated with a thickness of 4 to 6 cm.
Copper plating films with a thickness of μm were deposited and formed.

The malleability of the copper-plated films thus formed was measured by a 180° bending test, and the results are shown in Table 2. The ductility test was conducted by rolling the copper plated film in a certain direction at 180°C.
゜Repeat the operation of bending, returning the fold to its original position, applying pressure to flatten the crease, and the number of times it takes for the copper plating film to break at the crease (number of times the plating film can withstand) It was evaluated based on the following.

In addition, in the chemical copper plating solution having the composition of Example 7, a water-soluble cyanide compound was used instead of sodium cyanide (
a) = Sodium nitroprusside (50W19/l)
, (b) Potassium nickel cyanide (100mg/l)
or (c) potassium ferrocyanide (50W19/
A copper plating film was precipitated and formed under the same conditions using a plating solution with the same composition as above (a), and the spreadability of the plating film was evaluated.
22 times in the case of (b) and 20 times in the case of (c).

Tables 1 and 2 also include, as comparative examples, the case where chemical copper plating without adding a nonionic surfactant, which is a feature of the present invention, is used.

Claims (1)

[Scope of Claims] 1. A chemical copper plating solution characterized by containing a copper salt, a complexing agent, a reducing agent, a pH adjuster, and a nonionic surfactant consisting of a polyoxyethylene derivative of a phenolic resin. 2 In claim 1, the nonionic surfactant made of a polyoxyethylene derivative of phenolic resin has a general formula, ▲mathematical formula, chemical formula, table, etc.▼ (In the formula, R_1 and R_2 are hydrogen atoms, alkyl groups, cyclo Alkyl group, allyl group, aralkyl group, l, m, n are 1
A chemical copper plating solution characterized by being a compound represented by (indicating an integer greater than or equal to).