JP2001247973A - Cleaning and conditioning agent and electroless copper plating method for printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly form electroless copper plating films to various printed circuit boards with tight adhesion. SOLUTION: This cleaning and conditioning agent for electroless copper plating of various kinds of printed circuit boards contains a water soluble titanate coupling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning and cleaning method used for a pretreatment before forming an electroless copper plating film on a non-conductive surface (including a through-hole wall surface and a non-through hole surface) of a printed wiring board.
The present invention relates to a conditioner and a method for electroless copper plating of a printed wiring board using the conditioner.

[0002]

2. Description of the Related Art In order to apply electroless copper plating to a non-conductive surface of a printed wiring board, palladium having a catalytic action on electroless copper plating on a non-conductive surface is required. Grant is required.

Conventionally, a pretreatment step of electroless copper plating for applying palladium is to apply palladium sufficient to uniformly apply electroless copper plating to glass fibers exposed on the surface of a through hole of a printed wiring board. In order to neutralize the negative charge of the glass fiber, a processing solution containing a cationic compound for cleaning and adjustment was required. for that reason,
In a multi-layer printed wiring board (a so-called build-up multi-layer printed wiring board) in which an interlayer resin insulating layer and a conductor circuit are alternately laminated, an interlayer resin insulating layer in which no glass fiber exists,
A layer of a cationic compound is formed on the interlayer resin insulation layer,
There is a problem that the adhesion of the electroless copper plating is reduced.

The present invention has been made to improve the above circumstances, and has good electroless copper plating film adhesion not only to a non-conductive surface where glass fiber is exposed but also to a non-conductive surface where no glass fiber is present. It is an object of the present invention to provide a cleaning / adjusting agent for forming a liquid crystal and a method for electroless copper plating of a printed wiring board using the same.

[0005]

Means for Solving the Problems and Embodiments of the Invention As a result of diligent studies to achieve the above object, the present inventor has conducted a palladium application treatment after treating a printed wiring board with a cleaning and conditioning agent. Performing, then, when performing electroless copper plating to form an electroless copper plating layer on the non-conductive surface of the printed wiring board, by using a cleaning and conditioning agent containing a titanate coupling agent, In the same manner as when a conventional cleaning / conditioning agent containing a cationic compound is applied to the through-hole wall surface of a printed wiring board where glass fibers are exposed, an electroless copper plating film can be formed with good adhesion and uniformity. An electroless copper plating film can be formed with excellent adhesion to a printed wiring board of an interlayer resin insulation layer free of the presence of a non-conductive surface. It has been found that by treating a wall surface and a non-through hole surface with an aqueous solution for cleaning and adjustment containing a titanate coupling agent, electroless copper plating can be performed with good adhesion, and the present invention has been accomplished. Was.

Accordingly, the present invention provides (1) a cleaning and conditioning agent for electroless copper plating of a printed wiring board, which comprises a water-soluble titanate coupling agent, and (2) cleaning and conditioning of a printed wiring board. In the method of electroless copper plating of a printed wiring board, in which a palladium imparting treatment is performed after the treatment with an agent, and then an electroless copper plating is performed to form an electroless copper plating layer on a non-conductive surface of the printed wiring board,・
Provided is a method for electroless copper plating of a printed wiring board, characterized by using a cleaning / conditioning agent containing a water-soluble titanate coupling agent as a conditioner.

Hereinafter, the present invention will be described in more detail.
In the method for electroless copper plating of a printed wiring board according to the present invention, the steps can be performed according to a known step, and cleaning and cleaning are performed for surface conditioning of the printed wiring board.
It is possible to adopt a known method of immersing in an adjusting agent, applying a metal palladium nucleus, and performing electroless copper plating.

Examples of the printed wiring board include those having glass fibers such as glass epoxy resin, those having no glass fibers such as an interlayer resin insulating layer, and those having these laminated. May be a copper-clad board having a copper foil. In addition, through-holes (through holes)
Or a non-through hole. According to the present invention, the non-conductive portion of these printed wiring boards,
That is, the electroless copper plating film is formed on the surface of the printed wiring board (when the copper foil is not laminated), the wall surface of the through hole, the wall surface of the non-through hole, and the bottom surface. In the case of copper-clad boards,
Electroless copper plating is applied to the copper foil surface.

In the present invention, such a printed wiring board is first immersed in a cleaning / conditioning agent for cleaning / adjustment (cleaning and conditioning) of the substrate surface, through holes and non-through holes. However, in the present invention, a cleaning / conditioning agent containing a water-soluble titanate coupling agent is used.

In this case, as the water-soluble titanate coupling agent, for example, isopropyl tri (N-amidoethylaminoethyl) titanate, isopropyl tris (dioctyl pyrophosphate) titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis ( Dioctyl pyrophosphate) ethylene titanate. These titanate coupling agents are preferably contained in the washing / conditioning agent in an amount of 0.1 to 50 g / L, particularly 1 to 10 g / L.

The washing / conditioning agent includes a nonionic surfactant, a copper complexing agent,
A pH adjuster or the like can be blended. As the nonionic surfactant, for example, polyoxyalkylene alkyl ether, polyalkylene glycol, a copolymer of polyalkylene glycol, and the like can be used, and the blending amount is 0.1 to 50 g / L, particularly 1 to 10 g / L. It can be. Further, as a copper complexing agent, diethylene triamine, monoethanolamine, triethanolamine, sodium gluconate and the like can be compounded, and the compounding amount is 0.1 to 10 g / L, particularly 0.5 to 10 g / L. be able to. Further, as the pH adjuster, ammonia water, sodium hydroxide, sodium tetraborate and the like can be blended. In this case, the pH adjuster adjusts the pH of the cleaning / adjusting agent of the present invention to 7 to 13, especially 10 to 12 Can be blended.

The printed wiring board can be treated by immersing it in this cleaning / conditioning agent. The treatment conditions are 30 to 70 ° C., particularly 40 to 60 ° C., and 1 to 20 ° C.
Minutes, particularly preferably 3 to 10 minutes.

In the present invention, after the treatment with the above-mentioned washing / conditioning agent, palladium imparting treatment is performed.
In the case of a copper-clad printed board, an etching process (soft etching) of the copper surface and an acid cleaning for cleaning the copper surface can be performed according to a conventional method before the palladium application process.

The above-mentioned palladium imparting treatment can also be performed by a known method, for example, an Alcup process manufactured by Uemura Kogyo KK can be adopted.

Next, electroless copper plating is performed, and a known method can also be adopted. A known electroless copper plating solution can be used, and plating can be performed under the usual conditions.

According to the present invention, the use of the above-mentioned cleaning / adjusting agent containing the titanate coupling agent makes it possible to obtain an electroless copper plating with good adhesion to a printed wiring board having an interlayer resin insulating layer free of glass fibers. A film can be formed, and an electroless copper plating film can be formed with good adhesiveness to a printed wiring board on which glass fibers are exposed. Therefore, it is effective for through-hole plating of a multilayer printed wiring board such as a build-up multilayer printed wiring board in which interlayer resin insulating layers and conductive circuits are alternately laminated.

[0017]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Example 1 For a printed wiring board having a surface of an epoxy-based interlayer resin insulating layer, 50
After immersion treatment at 7 ° C. for 7 minutes, palladium imparting treatment is performed in accordance with a conventional method (using Alcup process manufactured by Uemura Kogyo Co., Ltd.), and then into an electroless copper plating solution (Sulcup PEA manufactured by Uemura Kogyo Co., Ltd.) at 36 ° C. It was immersed for 30 minutes to perform electroless copper plating. Thereafter, for the purpose of measuring the adhesion strength, 30 μm of electrolytic copper plating was applied as auxiliary plating, and then 150 μm was applied.
C. for 1 hour, and then measured the 90.degree. Peel strength. Cleaning / conditioning agent composition Isopropyl tri (N-amidoethylaminoethyl) titanate 5 g / L Polyethylene glycol 5 g / L Diethylene triamine 5 g / L

Example 2 Example 2 was performed in the same manner as in Example 1 except that a printed wiring board having a surface made of glass epoxy resin was used for the test.

Example 3 A test was performed in the same manner as in Example 1 except that a printed wiring board made of a glass epoxy resin having a copper foil and a surface having an exposed through-hole of glass fiber was used for the test.

Comparative Example 1 The same operation as in Example 1 was carried out except that the cleaning / conditioning agent had the following composition containing a cationic compound. Cleaning / conditioning agent composition Quaternary compound of polyvinylimidazole 5 g / L Polyethylene glycol 5 g / L Diethylenetriamine 5 g / L

[Comparative Example 2] The same operation as in Comparative Example 1 was carried out except that a printed wiring board having a surface made of glass epoxy resin was used for the test.

[Comparative Example 3] The same procedure as in Comparative Example 1 was carried out except that a printed wiring board made of a glass epoxy resin having a copper foil and a surface having an exposed through-hole of glass fiber was used for the test.

Comparative Example 4 The same procedure as in Example 1 was carried out except that the cleaning / conditioning agent had the following composition without a titanate coupling agent and a cationic compound. Cleaning / conditioning agent composition Polyethylene glycol 5 g / L Diethylene triamine 5 g / L

[Comparative Example 5] The same procedure as in Comparative Example 4 was carried out except that a printed wiring board having a surface made of glass epoxy resin was used for the test.

Comparative Example 6 The same procedure as in Comparative Example 4 was carried out except that a printed wiring board made of a glass epoxy resin having a copper foil and having a through hole in which glass fibers were exposed was used for the test. Table 1 shows the above results.

[0027]

[Table 1]

[0028]

According to the present invention, an electroless copper plating film can be formed on various printed wiring boards uniformly and with good adhesion.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 3/26 H05K 3/26 E (72) Inventor Masahiro Maruko 1-5-1, Exit Hirakata-shi, Osaka 4H003 BA12 DA15 EB13 EB26 EB36 ED02 4K022 AA02 AA13 AA18 AA37 BA08 CA03 CA06 CA16 CA17 CA21 CA22 DA01 5E343 AA15 AA17 BB24 BB67 CC73 DD33 EE02 GG02

Claims (2)

[Claims] 1. A cleaning / conditioning agent for electroless copper plating of a printed wiring board, comprising a water-soluble titanate coupling agent. 2. A printed circuit board comprising a printed wiring board, which is treated with a cleaning and conditioning agent, palladium is applied, and then electroless copper plating is performed to form an electroless copper plating layer on a non-conductive surface of the printed wiring board. An electroless copper plating method for a printed wiring board, wherein a cleaning / conditioning agent containing a water-soluble titanate coupling agent is used as the cleaning / conditioning agent.