JP2000303186A - Electroless plating method, electrode structural body and conductive paste used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely and efficiently execute plating on desired electrodes by forming electrodes contg. a metallic component to be formed into a catalyst and applying electroless plating on the electrodes. SOLUTION: Ag powder as conductive component, Pd powder to be formed into a catalyst, an organic solvent and a resin are blended and kneaded to prepare conductive paste 1. This conductive paste 1 is applied to a prescribed position on a substrate 2 so as to form into a prescribed electrode pattern. The conductive paste 1 is heat-treated and baked to form plural thick film electrodes 3. If required, the surfaces of the thick film electrodes 3 are degreased or subjected to etching for improving their adhesion with plating films. Then, the substrate 2 is dipped into an electroless plating bath contg. Ni as plating metal to form Ni plating films 4 on he surfaces of the thick film electrodes 3. Moreover, this substrate 2 is dipped into an electroless plating bath contg. Au as plating metal, and Au plating films 5 are formed on the Ni plating films 4 formed on the surfaces of the thick film electrodes 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer ceramic electronic component having a structure in which ceramic layers and internal electrodes are stacked.

[0002]

2. Description of the Related Art
As a method of forming electrodes on substrates and electronic component elements,
A method is widely used in which an electrode is formed by applying (printing) a conductive paste to a predetermined position on a substrate or an electronic component element by screen printing or the like, and then firing the applied paste.

In order to improve the solderability and solder heat resistance of the electrode formed as described above, the surface of the electrode is plated with Ni, and then the Ni is plated.
Au plating is further applied on the plating film, or
Sn plating, solder plating, and the like are further performed on the Ni plating film.

[0004] Further, when plating is performed on an electrode in a small area, it is difficult to perform electroplating by energizing the electrode.
An electroless plating method of performing plating using a reduction reaction is widely used.

[0005] In the conventional electroless plating method, a substrate or an electronic component element on which an electrode is formed is chemically replaced.
To promote the reduction reaction, immerse in a solution containing a catalyst for electroless plating (catalyst applying solution) to apply the catalyst to the electrodes, and then immerse the substrate and electronic component elements in the electroless plating solution. By doing so, a substitution / reduction reaction between the catalyst and the main metal ion in the plating solution is caused to form an electroless plating film on the surface of the electrode.

However, in the above-mentioned conventional method, the substrate on which the electrodes are formed is immersed in a catalyst application liquid to apply a catalyst to the electrodes, and then electroless plating is performed. The catalyst will adhere to portions other than the electrodes. Therefore, before performing the electroless plating, cleaning is performed in order to remove a catalyst attached to an unnecessary portion. For this reason, there is a problem that the time required for the entire electroless plating process becomes longer, and improvement in productivity is hindered.

Further, even if a cleaning step is provided to perform the cleaning,
There is a problem that a small amount of the adsorbed catalyst remains and the plating metal adheres to the portion, which may cause a short circuit between independent electrodes in some cases.

Further, in the conventional electroless plating method, the entire substrate or electronic component element is immersed in the catalyst-imparting liquid, so that the electroless plating is selectively performed only on a desired electrode among a plurality of electrodes. Is difficult to perform.

The present invention solves the above-mentioned problems, and does not require a step of applying a catalyst and a step of washing after the formation of an electrode, and can reliably and efficiently apply electroless plating to a desired electrode. An object of the present invention is to provide a possible electroless plating method, a highly reliable electrode structure, and a conductive paste for forming an electrode suitable for use in the electroless plating method of the present invention.

[0010]

In order to achieve the above object, an electroless plating method according to the present invention (claim 1) is an electroless plating method for forming a plating film on the surface of an electrode. It is characterized in that an electrode containing a metal component serving as a catalyst when plating is formed, and electroless plating is performed on the electrode.

In the electroless plating method of the present invention,
After forming an electrode containing a metal component serving as a catalyst when performing electroless plating, since the electroless plating is performed on the electrode, the formed electrode already contains a catalyst metal, As in the case of the conventional electroless plating method, a step of applying a catalyst (catalyst metal) to the electrode before performing the electroless plating and a washing step for removing the catalyst attached to the periphery of the electrode are not required. Therefore, production efficiency can be improved. In addition, since the plating metal does not adhere to unnecessary portions, short-circuiting between independent electrodes can be prevented, and reliability can be improved.

The electrode may be formed by applying a conductive paste containing a metal component (catalyst metal) serving as a catalyst when applying electroless plating and baking the same to form a thick-film electrode. It can be formed by various methods such as a method of forming a thin film electrode by a dry thin film forming method using the method, and there is no particular limitation on a method of forming the electrode.

[0013] Further, by making only the electrode to be subjected to electroless plating an electrode containing a catalytic metal, it becomes possible to selectively perform electroless plating only on a desired electrode.

The catalyst metals usable in the present invention include palladium (Pd) and gold (A
u), platinum (Pt), and alloys thereof.
When plating a metal that functions as a self-catalyst by a reduction reaction, the same metal as the metal to be plated by electroless plating can be used as the catalyst metal.

In the electroless plating method according to a second aspect of the present invention, a thick-film electrode is formed by applying and baking a conductive paste containing a metal component serving as a catalyst when performing electroless plating. It is characterized by.

A thick-film electrode is formed by applying and baking a conductive paste containing a catalyst metal as an electrode,
By performing electroless plating on this thick film electrode, it becomes possible to easily form an electrode containing a catalytic metal, and it is possible to efficiently perform electroless plating on the surface thereof. It can be more effective.

Further, by forming only the electrode to be subjected to electroless plating using a conductive paste containing a catalytic metal, it is possible to selectively perform electroless plating only on a desired electrode.

The electrode structure of the present invention (claim 3) includes an electrode containing a metal component serving as a catalyst for electroless plating, and an electroless plating film formed on the surface of the electrode. It is characterized by:

The electrode structure of the present invention comprises an electrode containing a metal component which serves as a catalyst when performing electroless plating, and an electroless plating film formed on the surface thereof. It has excellent weather resistance and high reliability. Further, the electrode structure having such a configuration,
According to the electroless plating method of the present invention described in the first aspect, it is possible to surely and efficiently manufacture.

The electrode structure according to a fourth aspect of the present invention is a thick-film electrode formed by applying and baking a conductive paste containing a metal component that becomes a catalyst when performing electroless plating. It is characterized by:

Applying a conductive paste to form electrodes (thick film electrodes)
In the case of forming an electrode, it is possible to easily form an electrode containing a catalyst metal without needing a special process or special conditions only by blending the catalyst metal into the conductive paste in advance. The present invention can be made more effective.

The conductive paste of the present invention (claim 5) is a conductive paste for forming a thick-film electrode to be subjected to electroless plating, and contains a metal component serving as a catalyst for electroless plating. It is characterized by containing.

Since the conductive paste contains a metal component serving as a catalyst for electroless plating, it is coated and baked, and no special process for applying the catalyst is required. It is possible to easily and reliably form a thick film electrode containing a metal. Therefore,
By using this conductive paste, the electroless plating method of the present invention can be efficiently performed.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be shown and the features thereof will be described in more detail.

In this embodiment, a plurality of electrodes are formed on a substrate, and the surface thereof is subjected to electroless plating, and the electrode includes an electrode and an electroless plating film formed on the surface. The case where a structure is formed will be described as an example. First, silver (Ag) powder, which is a conductive component, and metal powder, which serves as a catalyst when performing electroless plating (in this embodiment, P
d powder), an organic solvent, and a resin are blended and kneaded to prepare a conductive paste. Then, as shown in FIG.
Is applied to a predetermined position on the substrate 2 so as to form a predetermined electrode pattern. Then, a plurality of electrodes (thick film electrodes) 3 are formed as shown in FIG. Then, if necessary, the surface of the thick film electrode 3 is degreased to remove dirt and oil, and the surface of the thick film electrode 3 is improved to improve the adhesion between the thick film electrode 3 and the plating film. Is etched. Then, the substrate 2 on which the thick film electrode 3 is formed is immersed in a plating bath for electroless plating containing nickel (Ni) as a plating metal to perform electroless plating, and as shown in FIG. A Ni plating film 4 is formed on the surface of the thick film electrode 3. Further, the substrate 2 was immersed in a plating bath for electroless plating containing Au as a plating metal to perform electroless plating, and formed on the surface of the thick film electrode 3 as shown in FIG. An Au plating film 5 is further formed on the Ni plating film 4.

According to the electroless plating method of the above embodiment, the metal component (P
After the thick-film electrode is formed using the conductive paste containing d), the electroless plating of Ni is performed on the thick-film electrode, so that the formed thick-film electrode already contains the catalytic metal. As in the case of the above-mentioned conventional electroless plating method, a step of applying a catalyst to a thick film electrode before performing electroless plating is not only unnecessary, but also a catalyst metal adheres around the thick film electrode. This eliminates the need for a washing step for removing the attached catalyst metal before the electroless plating is performed, thereby improving production efficiency. In addition, it is possible to reliably prevent the plating metal from adhering to unnecessary portions, to prevent short-circuiting between independent thick film electrodes, and to improve reliability.

Further, as described above, N on the Ag thick film electrode
The electrode structure formed by providing the i-plated film and the Au-plated film is excellent in solderability, corrosion resistance, weather resistance, and the like, and has high reliability.

In this embodiment, in the above process, the Ni plating film 4 formed on the surface of the thick film electrode 3 is formed.
Is further electrolessly plated on the Ni plating film 4. When Au is electrolessly plated on the Ni plating film 4, even if the Ni plating film 4 is not provided with a catalyst metal,
Since the electroless plating of Au can be performed, a treatment for imparting a catalytic metal is not particularly required. However, Ni
In the case where another metal is electrolessly plated on the plating film 4, if necessary, the electroless plating may be performed after the catalyst metal is applied.

Further, in the above embodiment, the case where the Ni electroless plating film and the Au electroless plating film are formed on the Ag thick film electrode has been described as an example. There is no special restriction on the type of electroless plating film to be formed on the surface, and it can be widely applied to the case where electroless plating films made of various metals are formed on thick film electrodes made of various electrode materials. It is possible.

Further, in the above embodiment, the case where the electroless plating film is formed on the surface of the electrode formed on the substrate has been described as an example. The present invention is also applicable to a case where electroless plating is performed on an electrode formed on a component element.

The present invention is not limited to the above embodiment in other respects, and various applications and modifications can be made within the scope of the invention.

[0032]

As described above, according to the electroless plating method of the present invention (claim 1), after forming an electrode containing a metal component serving as a catalyst when performing electroless plating, the electroless plating method is performed on the electrode. Since the electroplating is performed, the formed electrode already contains the catalyst metal, and the catalyst (catalyst metal) is applied to the electrode before performing the electroless plating as in the case of the conventional electroless plating method described above. ) Is unnecessary, and the washing step for removing the catalyst attached to the periphery of the electrode is not required, so that the production efficiency can be improved. In addition, since the plating metal does not adhere to unnecessary portions, short-circuiting between independent electrodes can be prevented, and reliability can be improved.

Further, by making only the electrode to be subjected to electroless plating an electrode containing a catalyst metal, it becomes possible to selectively apply electroless plating only to a desired electrode.

Further, as in the electroless plating method of the present invention, a thick-film electrode is formed as an electrode by applying and baking a conductive paste containing a catalyst metal, and the electroless plating is performed on the thick-film electrode. Thus, the electrode containing the catalyst metal can be easily formed, and the surface thereof can be efficiently subjected to the electroless plating, so that the present invention can be made more effective.

Further, by forming only the electrodes to be subjected to electroless plating using a conductive paste containing a catalyst metal, it becomes possible to selectively perform electroless plating only on desired electrodes.

Further, the electrode structure of the present invention (claim 3) includes an electrode containing a metal component serving as a catalyst when performing electroless plating, and an electroless plating film formed on the surface thereof. It is excellent in solderability, corrosion resistance, weather resistance, etc., and has high reliability. Further, the electrode structure having such a configuration can be reliably and efficiently manufactured by the electroless plating method according to the present invention.

In the case where an electrode (thick film electrode) is formed using a conductive paste as in the electrode structure of the fourth aspect, a special effect is obtained only by blending a catalyst metal in the conductive paste in advance. The electrode containing the catalyst metal can be easily formed without requiring any special steps or special conditions, and the present invention can be made more effective.

In the conductive paste of the present invention (claim 5), since the conductive paste contains a metal component serving as a catalyst for electroless plating, the catalyst is applied only by coating and baking. It is possible to easily and surely form a thick-film electrode containing a catalytic metal without specially requiring a special step for forming the thick-film electrode. Therefore, by using this conductive paste, the electroless plating method of the present invention can be efficiently performed.

[Brief description of the drawings]

FIGS. 1A to 1D are views showing each step of an electroless plating method according to an embodiment (Embodiment 1) of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive paste 2 Substrate 3 Electrode (thick film electrode) 4 Ni plating film 5 Au plating film

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiro Adachi 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto F-term in Murata Manufacturing Co., Ltd. (reference) 4K022 AA02 AA41 BA03 BA14 CA06 CA20 CA21 CA22 CA29 DA01 5E001 AF06 AH07 AJ03 5E082 AB03 BC36 FG26 GG10 GG26 GG28 JJ03 JJ21 JJ23 5E343 AA23 BB23 BB25 BB44 BB48 BB72 CC71 DD33 ER32 GG11

Claims (5)

[Claims] 1. An electroless plating method for forming a plating film on a surface of an electrode, comprising: forming an electrode containing a metal component serving as a catalyst when performing electroless plating; An electroless plating method characterized by applying. 2. A thick-film electrode according to claim 1, wherein said electrode is formed by applying and baking a conductive paste containing a metal component to be a catalyst when performing electroless plating. Electroplating method. 3. An electrode structure comprising: an electrode containing a metal component serving as a catalyst for electroless plating; and an electroless plating film formed on a surface of the electrode. 4. The electrode according to claim 3, wherein said electrode is a thick-film electrode formed by applying and baking a conductive paste containing a metal component which becomes a catalyst when performing electroless plating. Electrode structure. 5. A conductive paste for forming a thick film electrode to be subjected to electroless plating, wherein the conductive paste contains a metal component serving as a catalyst for electroless plating.