JP2003293143A - Cleaning agent for palladium catalyst, method for cleaning palladium catalyst, method for plating electronic parts using the agent, and electronic parts - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently remove palladium deposited on portions other than a portion to be plated. <P>SOLUTION: After subjecting a material to be plated, on whose surface a Cu electrode has been formed, to a dewaxing process 11 and an etching process 12, a palladium catalyst is imparted to the material to be plated in a catalyst-imparting process 13. In a catalyst-cleaning process 14, a palladium catalyst-cleaning agent containing 2 to 6,800 mol/m<SP>3</SP>ammonium ions and chloride ions and having a pH of 5 to 14 is provided, and the palladium catalyst deposited on the portions other than the Cu electrode is cleaned and removed by dipping the material to be plated in the cleaning agent. In an electroless Ni-plating process 15, a Ni-P film is formed on the Cu electrode by carrying out electroless Ni-plating using a phosphinate as a reducing agent. Further, after conducting a dilute acid treatment process 16, an Au film is formed on the Ni-P film in a substitution Au-plating process 17. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a palladium catalyst cleaning agent, a method for cleaning a palladium catalyst, a method for plating an electronic component using the cleaning agent, and an electronic component. A palladium catalyst cleaning agent for cleaning and removing the attached palladium catalyst, a cleaning method for the palladium catalyst, a plating method for electronic parts for electroless plating using the cleaning agent, and a manufacturing method using the plating method Related electronic components.

[0002]

2. Description of the Related Art Conventionally, in an electronic component having a wiring pattern formed on the surface of a ceramic substrate or a printed circuit board,
An Au film is formed by plating on the Cu electrode, which is the base electrode of the wiring pattern, from the viewpoint of improving solderability and bonding property, but to prevent Cu, which is the electrode material, from diffusing into the Au film. In general, a Ni film is generally interposed between the Cu electrode and the Au film.

Further, in this type of electronic component, the electrode pattern has become complicated due to the demand for miniaturization and high density,
Therefore, the Ni film is formed by electroless plating which is not affected by the current distribution. That is, the Ni film is formed by autocatalytic electroless plating using a reducing agent such as a phosphoric acid compound.

By the way, in order for the electroless plating reaction to proceed, Cu as an electrode material needs to be catalytically active for the oxidizing reaction of the reducing agent, but Cu generally oxidizes the reducing agent such as a phosphorus compound. It is said that the catalytic activity is low for the reaction.

Therefore, conventionally, as a pretreatment for the plating treatment, after applying a palladium catalyst showing a good catalytic activity to the oxidation reaction of various reducing agents to the surface of the object to be plated,
Palladium adhering to sites other than the Cu electrode is removed using an acidic solution such as hydrochloric acid or sulfuric acid, and then electroless plating is performed to selectively remove Ni only on the Cu electrode.
A plating film such as a Ni-P film containing as a main component is formed.

[0006]

However, in the above prior art, after the palladium catalyst is applied to the surface of the object to be plated, the palladium adhering to the site other than the Cu electrode, which is the site to be plated, is washed with an acidic solution. Although we are trying to remove it, an acidic solution such as hydrochloric acid or sulfuric acid will dissolve the palladium itself, so even if we want to dissolve and remove only the palladium on the ceramic body, increasing the concentration of the acidic solution on the Cu electrode Even the palladium formed on the surface will be dissolved and removed. On the other hand, if the concentration of the acidic solution is lowered, the washing will be insufficient and the palladium will remain on the ceramic body, so that the palladium on the ceramic body will not be completely removed. There was a problem that it could not be removed.

That is, even if the palladium catalyst is washed with an acidic solution as in the prior art, since the washing method is to dissolve and remove palladium with an acidic solution in principle, the Cu to be plated is the target portion. It is difficult to wash away only the palladium on the non-plating target ceramic body while leaving the palladium on the electrode as it is. Therefore, even if electroless Ni plating is performed, the Cu electrode is not removed on the Cu electrode. A portion where the plating metal does not deposit occurs, and a plating metal with palladium as a catalyst nucleus deposits on the ceramic body. In other words, the conventional catalyst cleaning method has a problem that it is difficult to form a desired Ni film only on the Cu electrode.

The present invention has been made in view of the above problems, and a palladium catalyst cleaning agent and a palladium catalyst cleaning method capable of efficiently removing palladium attached to a site other than a plating target site. And a method for plating an electronic component using the cleaning agent, and an electronic component manufactured by using the plating method.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above-mentioned object. As a result, the inclusion of ammonium ions in the cleaning agent prevents the palladium on the Cu electrode from being removed. It was found that only palladium attached to a portion other than the electrode can be removed by washing.

The present invention has been made based on these findings. The palladium catalyst cleaning agent according to the present invention,
A palladium catalyst cleaning agent for cleaning and removing a palladium catalyst adhering to a site other than a plating target site of a plated object having a palladium catalyst provided on the surface thereof, characterized by containing at least ammonium ion .

[0011] Palladium is firmly bonded on the plating target site such as Cu by the substitution reaction with the base metal, but is attached to the surface by weak physical adsorption on the ceramic site other than the plating target site.

Therefore, by containing at least ammonium ion in the detergent, palladium physically adsorbed on the object to be plated easily forms a coordination compound with the ammonium ion and is released from the object to be plated. As a result, it becomes possible to easily wash and remove the palladium adhered to the portion other than the portion to be plated on the object to be plated.

Further, as a result of further intensive studies, the present inventors have found that chloride ions are effective in promoting the formation of the coordination compound.

That is, the palladium catalyst detergent of the present invention is characterized by containing chloride ions.

Further, in order to secure a desired detergency for the palladium catalyst, it is necessary to limit the concentration of ammonium ions and chloride ions, and the hydrogen ion exponent pH of the detergent within a predetermined range.

From this point of view, in the palladium catalyst detergent of the present invention, the ammonium ion has a molar concentration of 2
˜6800 mol / m ³ and a hydrogen ion exponent pH of 5
It is preferable that the chloride ion is adjusted to 2 to 68 at a molar concentration.
00 mol / m ³ and a hydrogen ion exponent pH of 5 to 14
It is also preferable that it is prepared in

Further, the method for cleaning a palladium catalyst according to the present invention is characterized in that the palladium catalyst cleaning agent is brought into contact with an object to be plated having a palladium catalyst.

According to the above-mentioned cleaning method, the palladium catalyst cleaning agent containing at least ammonium ions, preferably containing a predetermined amount of chloride ions and adjusted to a predetermined pH is brought into contact with the object to be plated. Only the palladium catalyst adhering to the site other than the plating target site can be efficiently and promptly washed and removed.

Further, in the method for plating an electronic component according to the present invention, a ceramic element body having a conductive portion formed on the surface of the ceramic element body is used as an object to be plated, and the object to be plated is subjected to electroless plating. A plating method, a catalyst applying step of applying a palladium catalyst to the object to be plated, and a cleaning step of cleaning and removing the palladium catalyst adhered to a site other than the conductive portion by using the cleaning method of the palladium catalyst. In addition, the electroless plating is characterized in that it is an electroless nickel plating, further, the electroless nickel plating, a boron compound is used as a reducing agent, or a phosphorus compound is used as a reducing agent. It is characterized by doing.

According to the above plating method, it is possible to selectively deposit the plating metal only on the conductive portion without depositing the plating metal on the ceramic body. It becomes possible to form a plating film such as a -P film or a Ni-B film.

The electronic component according to the present invention is characterized by being manufactured using the above plating method.

According to the above structure, it is possible to obtain an electronic component such as a ceramic multilayer substrate in which a desired plating film is formed only on the conductive portion even when the conductive portion has a complicated shape pattern.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail.

The palladium catalyst detergent as one embodiment of the present invention contains 2 to 6800 mol / m ³ of ammonium ion and chloride ion, and has a hydrogen ion exponent pH.
Are prepared in 5-14.

When the ceramic body on which the Cu electrode is formed is used as an object to be plated and the object to be plated is immersed in a palladium catalyzed treatment liquid to apply the palladium catalyst to the surface of the object to be plated, the Cu electrode on the Cu electrode Palladium is fixed on the Cu electrode by a strong bond formed by substitution reaction of the surface layer of the Cu electrode with palladium, whereas palladium on the ceramic body has a force of van der Waals force. It adheres to the ceramic body by weak physical adsorption.

That is, unlike the palladium on the Cu electrode, the palladium on the ceramic body is due to physical adsorption having a weak adsorption force. Therefore, when the object to be plated is immersed in a detergent containing ammonium ions, Coordination compound ([Pd (NH ₃ ) ₄ ] with ammonium ion
⁽²⁺ etc.) can be easily formed and separated from the ceramic body, whereby the palladium catalyst on the ceramic body can be efficiently washed and removed without washing and removing the palladium catalyst on the Cu electrode. .

Moreover, it was found from the experimental results of the present inventors that the chloride ion mixed in the detergent promotes the formation of the above-mentioned coordination compound (complex).

Therefore, the palladium detergent of the present embodiment contains ammonium ions and further chloride ions.

Further, in the present embodiment, the concentrations of ammonium ion and chloride ion in the detergent are 2 to 6800.
The mol / m ³ and the hydrogen ion exponent pH are adjusted to 5 to 14, and the reason will be described below.

When the concentration of ammonium ion and chloride ion is less than 2 mol / m ³ and the pH value of hydrogen ion index is less than 5, the concentration of ammonium ion and chloride ion is low and the pH value of hydrogen ion index is low. It is not possible to form a coordination compound, and therefore it is not possible to exert a sufficient cleaning ability. On the other hand, when the concentration of ammonium ions and chloride ions exceeds 6800 mol / m ³ , palladium on the ceramic body can be completely removed by washing, but since the washing ability is too strong, the plating target Palladium on the Cu electrode, which is a site, is also removed by washing, and as a result, when electroless plating is performed, a non-precipitated portion of the plating metal is generated on the Cu electrode, and a desired plating film may not be formed. is there.

Therefore, in the present embodiment, the concentrations of ammonium ion and chloride ion are 2 mol / m ^{3 to} 680.
0 mol / m ³ , preferably 20 mol / m ^{3 to} 1000 mol
/ M ³ , hydrogen ion exponent pH 5 to 14, preferably 8
-12.

Ion-exchanged water can be used as the solvent of the cleaning agent, and ammonia water or hydrochloric acid can be used as the supply source of ammonium ions or chloride ions.

Next, the plating method of the present invention including the method for cleaning the palladium catalyst will be described.

FIG. 1 is a sectional view showing an embodiment of a ceramic multilayer substrate as an electronic component manufactured by the present plating method. The ceramic multilayer substrate comprises a plurality of ceramic sheets (first to fifth layers). Ceramic sheets 1a-1e)
Are laminated to form the ceramic body 6.

Further, the outer conductors 4 (4a to 4c) are formed on the surface of the ceramic body 6, and the inner conductors 3 (3a to 3) having a predetermined pattern are formed inside the ceramic body 6.
h) is buried, and the inner conductors 3 or the inner conductors 3 and 4 are electrically connected to each other via the via holes 5 (5a to 5k). Then, in the present embodiment, the internal conductor 3g is interposed via the fourth ceramic sheet 1d.
And the inner conductor 3e are arranged to face each other to form a capacitor portion, and the outer conductor 4c and the inner conductors 3h, 3f, 3d, 3
b is electrically connected via via holes 5k, 5g, 5e, and 5c to form an inductor portion.

The outer conductor 4 is, as shown in FIG.
The Ni-P coating 8 is formed on the surface of the Cu electrode 7, and the Au coating 9 is further formed on the surface of the Ni-P coating 8.

The ceramic multi-layer substrate is made up of ceramic sheets 1a to 1 having a predetermined size by a doctor blade method or the like.
After producing e, the inner conductors 3a to 3h having a predetermined pattern are screen-printed using a Cu paste, and then the ceramic sheets 1a to 1e are laminated and pressure-bonded,
After firing, the surface of the ceramic body 6 is Cu
The paste is applied and baked to form the Cu electrode 7 having a predetermined pattern. Then, the ceramic element body 6 having the Cu electrode 7 formed thereon is subjected to electroless plating to form a Ni-P film 8 and an Au film 9 on the Cu electrode 7, thereby forming the ceramic multilayer substrate. Is manufactured.

FIG. 3 is a plating process diagram showing the processing procedure of the present plating method.

First, in the degreasing step 11, the object to be plated is degreased by using an acidic degreasing solution or an alkaline degreasing solution in order to remove contaminants from the object to be plated by an organic substance or an inorganic substance, followed by a water washing treatment. Do.

Next, in the etching step 12, the object to be plated is immersed in a predetermined etching solution to remove the oxide formed on the surface of the Cu electrode 7 by etching and to improve the adhesion with the plating film. Therefore, the surface shape is appropriately smoothed or roughened to finely adjust the surface shape, and then washed with water.

Here, a hydrogen peroxide type solution or an ammonium persulfate type solution can be used as the etching solution.

Next, in the catalyst applying step 13, the object to be plated is immersed in a mixed solution of hydrochloric acid and palladium chloride for a predetermined time (for example, 3 minutes) to apply the catalyst to the surface of the object to be plated.

Then, in the catalyst cleaning step 14, the above-mentioned palladium catalyst cleaning agent, that is, 2 to 6800 mol / m 2 is used.
^3. A palladium catalyst cleaning agent containing ammonium ion and chloride ion of ³ and having a hydrogen ion exponent pH of 5 to 14 is used, and the object to be plated is immersed in the cleaning agent for a predetermined time (for example, 1 minute). To do.

That is, by immersing the object to be plated in a palladium catalyst cleaning agent and bringing the cleaning agent into contact with the object to be plated, the coordination compound ([[ pd _{(NH 3) 4]}
²⁺ ) is formed, and the palladium component directly attached to the ceramic body is detached from the ceramic body.

In this way, only the palladium catalyst on the ceramic body 6 can be washed and removed from the surface of the ceramic body 6 without washing and removing the palladium catalyst on the Cu electrode 7. Then, after this, a water washing process is performed, and then the process proceeds to the electroless Ni plating step 15.

Next, in the electroless Ni plating step 15, N
A phosphinate as a phosphorus compound having an excellent reducing property for i is added as a reducing agent to a Ni plating solution, and electrocatalytic electroless Ni plating is performed to form a film having a thickness of 2 μm to 5 μm on the Cu electrode 7. The Ni-P film 8 is formed, and then water washing treatment is performed.

As the phosphinic acid salt, soluble salts such as sodium phosphinate, potassium phosphinate, calcium phosphinate and the like can be used.

In addition to the above-mentioned reducing agent, various nickel salts, complexing agents, pH buffering agents, stabilizers and the like are appropriately added to the Ni plating solution as a supply source of Ni ²⁺ .

Here, nickel hydroxide, nickel carbonate, nickel sulfate, nickel chloride, nickel sulfamate, nickel ammonium sulfate or the like can be used as the nickel salt.

A complexing agent is added in order to prevent Ni ²⁺ from existing in the plating solution and to precipitate as a nickel salt. Examples of such complexing agents include citric acid, lactic acid and tartaric acid. Oxycarboxylic acids such as, malonic acid, maleic acid, succinic acid, dicarboxylic acids such as glutamic acid, acetic acid,
A monocarboxylic acid such as glycine can be used.

The pH adjusting agent is added in order to prevent the hydrogen ion exponent pH in the Ni plating solution from greatly decreasing and the plating rate from decreasing. As such a pH buffering agent, For example, ammonium salts can be used.

As the stabilizer, for example, one or more selected from nitrates such as lead, bismuth and thallium, and predetermined sulfur compounds can be used.

Next, in the dilute acid treatment step 16, the object to be plated is immersed in 3 vol% to 10 vol% dilute sulfuric acid to perform dilute acid treatment. That is, there is a possibility that the Ni-P coating 8 is oxidized by the water washing treatment performed after the formation of the Ni-P coating 8 described above, and an oxide is formed on the surface. Therefore, the Au coating in the displacement Au plating described below is formed. In order to secure the adhesiveness with 9, a dilute sulfuric acid treatment is carried out with dilute sulfuric acid to remove the oxide, and then a water washing treatment is carried out.

Next, in the replacement Au plating step 17, Au is used.
⁺ Or Au ^{3 +} -containing plating solution (Au plating solution)
The object to be plated is dipped in to perform substitutional electroless Au plating (substitution Au plating), and the Au coating 9 is formed on the Ni-P coating 8.
To form.

[0055] That is, when immersing the object to be plated which Ni-P film 8 is formed on the Au plating solution, an electron is electrochemically less noble metal Ni is eluted (e ^-) to release, the release Noble Au ⁺ or Au due to the generated electrons (e ⁻ ).
³⁺ is reduced and Au is deposited on the Ni-P coating 8, whereby an Au coating 9 having a film thickness of 0.05 μm to 0.2 μm is formed on the Ni-P coating 8.

The Au plating solution Au ⁺ or Au ^{3+ is used.}
A gold salt such as sodium gold chloride, sodium gold sulfite, or potassium gold cyanide can be used as a supply source for the gold plating solution. In addition to the above gold salt, the Au plating solution can also contain sodium cyanide or sodium sulfite, Contains a complexing agent such as thiosulfate and other additives, and has a hydrogen ion index p
H is adjusted to 3-13.

In this embodiment, 2 to 6800
Since the palladium catalyst was washed using a palladium catalyst detergent containing a mol / m ³ ammonium ion and chloride ion and having a hydrogen ion exponent pH of 5 to 14, the palladium catalyst was provided on the Cu electrode 7. Only the palladium fixed to the ceramic body 6 can be efficiently washed and removed without washing and removing the removed palladium.
A desired plating film can be formed only on the electrode 7.

As described above, according to the present embodiment, even when the Cu electrode 7 has a complicated shape pattern, a desired plating film is formed on the entire surface of the Cu electrode 7 without protruding from the shape pattern. Therefore, it is possible to easily obtain a ceramic multilayer substrate as a high-quality and highly reliable electronic component in which external conductors 4 are not short-circuited with each other and migration or the like does not occur.

The present invention is not limited to the above embodiment. In the above-mentioned embodiment, Ni is formed on the Cu electrode 7.
-P coating 8 is formed, but electroless Ni plating using a boron compound such as dimethylamine borane or sodium tetrahydroborate as a reducing agent is applied to form Ni on the Cu electrode 7.
It is also preferable to form a -B film.

In the present embodiment, the case where Ni is used as the plating metal deposited by electroless plating has been described in detail, but the present invention is applicable to all electroless plating using palladium as a catalyst nucleus. Co, Cu, Ru,
Rh, Pd, Ag, Cd, In, Sn, Pb, Pt, A
When depositing a metal such as u alone, N, V, Cr,
It goes without saying that the present invention can also be applied to the case of depositing an alloy containing Mn, Fe, Zn, Mo, W, Re, Tl and the like.

Further, in the above embodiment, the Au film 9
Is formed only by the displacement Au plating, but after the displacement Au plating, self-catalytic electroless plating is performed to obtain a film thickness of 0.2.
It is also free to form a thick Au film of μm to 1 μm.

[0062]

EXAMPLE [First Example] As shown in FIGS. 4 and 5, the present inventors have prepared a large number of child substrates 2 having a length of 5 mm and a width of 4 mm.
100 mm in length and 100 mm in width in which 2 are arranged vertically and horizontally
Of the ceramic substrate 21 (parent substrate) is prepared, Cu electrodes 23 having a predetermined pattern (see FIG. 5) having a film thickness of 10 μm are formed so that the minimum distance between electrodes is 100 μm, and the ceramic substrate 21 is plated. As a result, electroless Ni plating was applied.

That is, first, the object to be plated is degreased by using ICP Clean 91 manufactured by Okuno Pharmaceutical Co., Ltd. as a degreasing solution, washed with water, and then the OPC-400 Soft Touch manufactured by Okuno Pharmaceutical Co. is used to perform the plating. The material was subjected to etching treatment to finely adjust the surface shape, smut was removed, and then washed with water.

Next, a mixed solution of hydrochloric acid-palladium chloride is prepared so that the palladium concentration becomes about 50 ppm to prepare a palladium catalyzed treatment liquid, and then the ceramic substrate is immersed in the palladium catalyzed treatment liquid for 3 minutes. Then, a palladium catalyst was applied to the ceramic substrate 21 and then washed with water.

After that, using ion-exchanged water as a solvent,
A palladium catalyst detergent containing 2 to 6800 mol / m ³ of ammonium ion and chloride ion and having a hydrogen ion exponent pH adjusted to 5 to 14 with aqueous ammonia was prepared. It was immersed in the cleaning agent at room temperature for 1 minute and then washed with water.

Next, "ICP nicol" manufactured by Okuno Seiyaku Co., Ltd., to which sodium phosphinate was added as a reducing agent, was added to Ni.
It was used as a plating solution and subjected to electroless Ni plating to prepare test pieces of Examples (Examples 1 to 4).

As a comparative example, the present inventors have found that the ammonium ion and chloride ion both have a molar concentration of 1.0.
Mol / m ³ and 8000 mol / m ³ of palladium catalyst cleaner were prepared, and then the palladium catalyst was cleaned using the cleaner, and then electroless Ni plating was performed as in Examples 1 to 4 above. Then, a comparative example test piece was produced (Comparative Examples 1 and 2).

Furthermore, the present inventors used 3 vol% sulfuric acid, 5 vol sulfuric acid, and 10 vol% sulfuric acid as a palladium catalyst cleaning agent, and after cleaning the palladium catalyst, the same as in Examples 1 to 4 above. Electroless Ni plating was performed to prepare comparative test pieces (Comparative Examples 3 to 5).

Further, a palladium catalyst was applied to the ceramic substrate 21 without washing with palladium, and after washing with water,
Immediately, a comparative test piece plated with electroless Ni was prepared (Comparative Example 6).

For each of the examples and comparative examples, N
The number of non-precipitations in the pattern where the i-P coating was not deposited on the Cu electrode 23 and the number of depositions outside the pattern where the Ni-P coating was deposited on the ceramic substrate 21 other than the Cu electrode 23 were measured.

Table 1 shows the measurement results.

[0072]

[Table 1] As is clear from Table 1, in Comparative Example 1, the hydrogen ion exponent pH is "5", but the molar concentration of ammonium ion and chloride ion is as low as 1.0 mol / m ^3, and therefore the cleaning ability is unsatisfactory. Sufficient, and deposition outside the pattern was confirmed at 5 locations.

In Comparative Example 2, the hydrogen ion exponent pH was "1.
4 ”, the ammonium ions and chloride ions have a high molar concentration of 8000 mol / m ^3, and therefore the cleaning ability is too strong, and not only the palladium catalyst on the ceramic substrate 21 but also the palladium catalyst on the Cu electrode 23 is used. It was removed by washing, and as a result, non-precipitation in the pattern was confirmed at three locations.

Comparative Examples 3 to 5 are 3 vol% to 10 vol.
%, The palladium catalyst is washed by using sulfuric acid, so that the palladium catalyst on the Cu electrode 23 is also dissolved and removed by these dilute sulfuric acid, and as a result, non-precipitation in the pattern at 3 to 33 locations is confirmed. Since the cleaning of the portion other than the electrode 23 on the ceramic substrate 21 is insufficient, 2
Deposition outside the pattern was confirmed at -20 locations.

Regarding the sulfuric acid concentration, as the volume fraction of sulfuric acid becomes higher, the dissolving power (etching power) increases and the dissolution of palladium progresses, so that the number of out-of-pattern precipitations decreases while the pattern precipitation number decreases. It was confirmed that the number of unprecipitated particles tends to increase.

In Comparative Example 6, since the palladium catalyst was not washed, it was confirmed that 105 out-of-pattern depositions were observed, and that out-of-pattern depositions increased.

On the other hand, in Examples 1 to 4,
The palladium catalyst was washed using a palladium catalyst detergent containing 6800 mol / m ³ of ammonium ion and chloride ion and adjusted to have a hydrogen ion exponent pH of 5 to 14, followed by electroless Ni plating. Therefore, the palladium firmly adhered to the Cu electrode 23 by chemical adsorption is not washed and removed from the Cu electrode 23, while the palladium physically adsorbed on the ceramic substrate 21 is ammonium ion and a coordination compound. ([Pd
(NH ₃ ) ₄ ] ²⁺ ) to form the ceramic substrate 2
It was confirmed that it was easily removed by washing from above 1 and that the number of non-precipitations in the pattern and the number of precipitations outside the pattern could both be "0".

[Second Embodiment] The present inventors prepared palladium catalyst detergents having different hydrogen ion exponents pH, and used the detergent to wash the palladium catalyst detergents as in the first embodiment. After that, electroless Ni plating was performed, and the number of non-precipitation in the pattern and the number of precipitation outside the pattern were measured.

Specifically, the molar concentration of ammonium ions was kept constant at 200 mol / m ³ , and the hydrogen ion exponent pH was
Of "5" and "5.4" were prepared, palladium cleaning and electroless Ni plating were carried out, thereby producing Example test pieces (Examples 11 and 12). Detergents having index pHs of "2", "3", and "4" were prepared, palladium cleaning and electroless Ni plating were performed, thereby preparing comparative test pieces (Comparative Examples 11 to 11).
13).

Then, the present inventors measured the number of non-precipitations in the pattern and the number of precipitations outside the pattern for each of the examples and comparative examples, as in the first example.

Table 2 shows the measurement results.

[0082]

[Table 2] As is clear from Table 2, Comparative Examples 11 to 13 have a hydrogen ion exponent pH of less than 5, and therefore have poor cleaning ability,
Therefore, some out-of-pattern precipitation was observed.

On the other hand, in Examples 11 and 12, since the hydrogen ion exponent pH was 5 or more, the palladium catalyst cleaning agent had sufficient cleaning ability, and the number of non-precipitation in the pattern and the number of non-precipitation in the pattern. It was confirmed that both can be set to "0".

[0084]

As described above in detail, the palladium catalyst cleaning agent according to the present invention cleans and removes the palladium catalyst adhered to a portion other than the plating target portion of the object to be plated having the palladium catalyst on the surface. Since it is a palladium catalyst cleaning agent and contains at least ammonium ions, palladium physically adsorbed on the object to be plated should easily form a coordination compound with the ammonium ions and be released from the object to be plated. Therefore, it becomes possible to easily wash and remove only the palladium that adheres to the site other than the site to be plated.

The ammonium ion content is 2 to 6800 mol / m ³ in terms of molar concentration, and the hydrogen ion exponent pH is adjusted to 5 to 14 to easily secure a desired cleaning ability. be able to.

Further, the present invention is 2-6800 mol / m.
By containing the chloride ion of ³ , the formation of the coordination compound can be promoted.

Further, in the method for cleaning a palladium catalyst according to the present invention, since the palladium catalyst cleaning agent is brought into contact with the object to be plated with the palladium catalyst, the palladium catalyst attached to the object to be plated is selectively removed. It can be easily removed by washing.

In addition, the method for plating an electronic component according to the present invention uses a ceramic body having a conductive portion formed on the surface of the ceramic body as an object to be plated, and an electronic component to be electroless plated on the object. A plating method, which comprises a catalyst applying step of applying a palladium catalyst to the object to be plated, and a cleaning step of cleaning and removing the palladium catalyst adhering to a site other than the conductive portion by using the cleaning method of the palladium catalyst. Therefore, it is possible to selectively wash and remove only the palladium catalyst that is physically adsorbed on the ceramic body other than the conductive part, without washing and removing the palladium catalyst on the conductive part that replaces the surface layer. You can

The electroless plating is electroless nickel plating, and the electroless nickel plating is
By using a phosphorus compound as a reducing agent, or by using a boron compound as a reducing agent, the plating metal will not be deposited on the ceramic body other than the conductive portion,
Therefore, a plating film such as a Ni-P film or a Ni-B film can be formed only on the conductive portion.

Further, since the electronic component according to the present invention is manufactured by using the above plating method, even if the conductive portion has a complicated shape pattern, a desired plating film is formed only on the conductive portion. A high-quality and highly reliable electronic component that can be formed without short-circuiting conductors or migration or the like can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an electronic component manufactured by a plating method according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of the electronic component.

FIG. 3 is a plating process diagram showing a processing procedure of a plating method for an electronic component according to the present invention.

FIG. 4 is a plan view schematically showing a ceramic substrate used in an example of the present invention.

5 is an enlarged view of part A in FIG.

[Explanation of symbols]

6 Ceramic body 7 Cu electrode (conductive part)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Soushi Numata             2-10-10 Tenjin, Nagaokakyo, Kyoto Stock             Murata Manufacturing Co., Ltd. F term (reference) 4K022 AA02 AA04 AA42 BA14 BA16                       CA07 DA01 DB02                 5E343 AA23 BB24 BB44 CC73 CC78                       DD33 EE02 EE16 GG11

Claims (10)

[Claims] 1. A palladium catalyst cleaning agent for cleaning and removing a palladium catalyst adhering to a site other than a site to be plated of an object to be plated on which a palladium catalyst has been applied, which contains at least ammonium ion. A palladium catalyst detergent characterized by the above. 2. The palladium according to claim 1, wherein the ammonium ion content is 2 to 6800 mol / m ³ in molar concentration, and the hydrogen ion exponent pH is adjusted to 5 to 14. Catalyst cleaning agent. 3. The palladium catalyst cleaning agent according to claim 1 or 2, which contains chloride ions. 4. The chloride ion content is 2 to 6800 mol / m ³ in molar concentration, and the hydrogen ion index p is
The palladium catalyst cleaning agent according to claim 3, wherein H is adjusted to 5-14. 5. A method for cleaning a palladium catalyst, which comprises bringing the palladium catalyst cleaning agent according to claim 1 into contact with an object to be plated with a palladium catalyst. 6. A method of plating an electronic component, wherein a ceramic body having a conductive portion formed on the surface of the ceramic body is used as an object to be plated, and the object to be plated is subjected to electroless plating. An electron comprising: a catalyst applying step of applying a palladium catalyst; and a washing step of washing and removing the palladium catalyst adhered to a portion other than the conductive portion by using the palladium catalyst washing method according to claim 5. Parts plating method. 7. The method of plating an electronic component according to claim 6, wherein the electroless plating is electroless nickel plating. 8. The method of plating an electronic component according to claim 7, wherein the electroless nickel plating uses a phosphorus compound as a reducing agent. 9. The electroless nickel plating is characterized by using a boron compound as a reducing agent.
The plating method for the electronic component described. 10. An electronic component manufactured by using the plating method according to any one of claims 6 to 9.