JPH08264371A - Manufacture of electronic component with electroless plated film - Google Patents

Abstract

PURPOSE: To reduce the variation in thickness of an electroless plated film by forming at least one of a plurality of conductive layers of an external electrode of an electroless plated film. CONSTITUTION: A baked conductive film 4 is formed by applying nickel conductive paste to both ends of a ceramic material 3 comprising internal electrodes 1 and ceramic inductors 2 alternately laminated and baking them. The material 3 is soaked in electroless copper plating liquid to form an electroless copper plated film 5 on the baked conductive film 4. After the electroless copper plated film 5 is degreased by alkaline liquid and rinsed in acid, soft-etching is done for removing oxide on a surface, and it is further soaked in electroless solder plating liquid to form an electroless solder plated film 6. Thus external electrodes 7, 7 are formed comprising the baked conductive film 4, the electroless copper plated film 5 and the electroless solder plated film 6 at both ends of the material 3. Thus an electronic component with an electroless plated film which is excellent in solder wettability and inexpensive can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an electronic component such as a chip type multilayer capacitor having an electroless plating film on an external electrode.

[0002]

2. Description of the Related Art Electronic components such as capacitors and inductors are used in many electronic devices. With the recent miniaturization of electronic devices, circuit components in which electronic components are densely mounted on a printed circuit board are used. As such electronic components for high-density mounting, chip-shaped electronic components such as chip-shaped multilayer ceramic capacitors, chip-shaped ceramic thermistors, and chip-shaped inductors are often used. These chip-shaped electronic components are made by forming external electrodes on both end faces of a prismatic type or columnar type ceramic element body of each element, and these external electrodes are soldered to the soldering lands of the printed circuit board before use. To be done. For example, in a chip-shaped monolithic ceramic capacitor, ceramic dielectric layers and internal electrodes are alternately laminated so that the end portions of the internal electrodes are alternately opposite to each other on both end faces of the ceramic body of the laminated body. External electrodes connected to the ends of the printed circuit board are formed on the end face, and the external electrodes are used by being soldered to the soldering lands of the printed board. In order to form the external electrodes of this chip-shaped monolithic ceramic capacitor and other chip-shaped electronic parts, a baking-type conductive paste containing Ag, Ag-Pd, Cu, Ni, etc. is applied to both end faces of each ceramic body. Then, baking is performed to form a thick underlayer. Next, with this baking film alone, when it is soldered to the soldering land of the printed circuit board, Ag is melted and transferred to the molten solder, and the baking film is thinned.
Since the phenomenon of so-called "solder erosion" occurs, plating of metals such as Ni and Cu is performed on this baked film, and further, the molten solder cannot be well wetted by the plating layer, Since practical soldering strength cannot be obtained, it is common practice to plate Sn or Sn and Pb solder on the plated layer to improve wettability with molten solder.

[0003]

The plating layer of these chip-shaped electronic parts is formed by electrolytic plating. It is necessary to provide the plating layer via an underlayer so that the non-conductor such as ceramics is directly electrolyzed. This is because plating cannot be performed, and the underlying layer is a thick film made of a coating film as described above. Therefore, for example, a thick film using a nickel-baking conductive paste avoids unevenness on the surface. I can't. When direct electrolytic solder plating is applied to the uneven surface, the plating current density in the convex portion increases and the plating film is formed thick, and the plating current density in the concave portion decreases and the plating film is formed thin. The plating current density varies, and the thickness of the plating film also varies accordingly. So-called plating throwing power is poor, and it is difficult to obtain a uniform plating film. As a result, when soldering chip-shaped electronic components to a printed circuit board, soldering May deteriorate the wettability of. As a solution in that case, electrolytic copper plating and electrolytic nickel plating are sequentially performed on the nickel thick film conductive film, and then electrolytic solder plating is performed, but the number of steps is large and it is disadvantageous in terms of cost. there were.

For example, in a laminated LC chip component, the inductors L ₁ and L ₂ and the capacitor C shown in FIG.
In the case of a T-type LC circuit connected to the mold, as shown in FIG.
The inductor section 11 and the capacitor section 12 are laminated, the former is constructed by connecting a pair of left and right coils 13, 14 and the latter is constructed by sandwiching a dielectric between a pair of upper and lower internal electrodes 15, 16, and a laminated body thereof. The external electrodes 17 on the outer wall of the LC circuit corresponding to the LC connection portion of the LC circuit, and the terminals of the coils 13 and 14 corresponding to the terminals of L ₁ and L ₂ respectively, are connected to the external electrodes 18 and 19 of the coils 13 and 14 similarly to A capacitor having a structure in which an external electrode 20 is provided on each terminal of the internal electrodes of the capacitor corresponding to the terminal is manufactured. The external electrode is obtained by performing so-called barrel electrolytic plating on a baking type conductive paste film. . In barrel electroplating, a cathode is provided inside a mesh barrel, and a plating bath is interposed between the cathode and an anode provided outside the barrel, and a plating target and a granular conductor dummy are placed in the barrel. , The plating is performed while stirring them together, and as is known from FIG. 2, _one of the terminals of L ₁ and L ₂ and its connecting portion is electrically connected to the cathode. Then, the other terminals are also electrically conducted, but the terminal of the capacitor C is electrically insulated from these, and the probability that the portion of is conducted is 1/3 of the case of, and as a result, The external electrodes 17 to 19 corresponding to are thicker in the plating film, and the external electrodes 20 corresponding to are thinner in thickness, causing variations in the thickness of the plating film and causing the same problem as described above.

A first object of the present invention is to provide an electronic component with an electroless plating film having an electroless plating film with a small variation in film thickness. A second object of the present invention is to provide an electronic component with an electroless plating film having an electroless plating film having excellent solder wettability. A third object of the present invention is to provide an electronic component with an electroless plating film, which has a small number of steps and has an electroless plating film which is advantageous in terms of cost.

[0006]

In order to solve the above-mentioned problems, the present invention provides (1) a method for manufacturing an electronic component having at least an external electrode on a ceramic body, wherein the external electrode contains a base layer and tin-containing material. A method for manufacturing an electronic component with an electroless plating film, which has a plurality of conductive layers having a plating layer as a surface layer, and at least one layer of the plurality of conductive layers is formed by an electroless plating film forming step. is there. Further, the present invention provides (2), in at least a method of manufacturing an electronic component having an external electrode on a ceramic body, the external electrode having a plurality of conductive layers having a base layer and a tin-containing plating layer as a surface layer, At least one layer of the plurality of conductive layers is formed by an electroless plating film forming step, and the tin-containing plating layer is formed by an electroless plating film forming step and heat-treated. (3) In the method for manufacturing an electronic component having an external electrode on at least a ceramic body, the external electrode has three layers of a base layer, a surface layer of a tin-containing plating layer, and an intermediate layer of both layers. Is a method of manufacturing an electronic component with an electroless plating film formed by an electroless copper plating film forming step, (4), a method of manufacturing an electronic component having an external electrode on at least a ceramic body, wherein the external electrode It has three layers, an underlayer, a surface layer of a tin-containing plating layer, and an intermediate layer between them, the intermediate layer being formed by an electroless copper plating film forming step, and the tin-containing plating layer being formed by an electroless plating film forming step. A method for manufacturing an electronic component with an electroless plated film which is formed and heat treated, (5), wherein the underlayer is a thick film of a coating film, and the electronic component with an electroless plated film according to any one of the above (1) to (4) The present invention provides a method for manufacturing the same.

In the present invention, the "electroless plating film forming step" is a plating film forming step obtained by plating with an "electroless plating solution". The "electroless plating solution" is a metal ion for plating. , An electroless plating solution containing at least a reducing agent, a complexing agent and an alkaline agent. Here, the metal ions for plating are ions of the metal to be plated on the object to be treated, for example, copper ions are used for copper plating, and nickel ions are used for nickel plating. Not limited to gold (Au) electroless plating, platinum (Pt) electroless plating, silver (Ag) electroless plating, palladium (Pd) electroless plating, electroless plating of these alloys and other metals, etc. Electroless metal plating can be performed, and in these cases, it refers to metal ions such as Au ions and Pt ions. Examples of counter ions of these metal ions include sulfate ions, nitrate ions, mineral ions such as chlorine ions, cyanide ions, and pyrophosphate ions. To supply them, for example, in the case of Cu ions, copper sulfate is used. , Copper nitrate, copper chloride, copper cyanide, copper pyrophosphate, etc., and the second cupric salt is particularly preferable, but other copper compounds such as metallic copper, copper oxides and the like are added to a mineral acid solution such as sulfuric acid. You may make it melt | dissolve and may be supplied, and also in the case of another metal ion, it can carry out according to this. The concentration of metal ions in the electroless plating bath is preferably 5 g / liter to 10 g / liter. If it is more than this, the metal deposition reaction is likely to occur in the plating bath, and if it is less than this, the metal deposition reaction of the plating on the object to be treated tends to be low.

The reducing agent refers to a compound capable of forming a metal film by reducing metal ions to be plated in the electroless plating solution and depositing the metal on the surface of the object to be treated. formalin, paraformaldehyde, dimethylamine borane, hypophosphite, hydrazine, glyoxylic acid, KBH _4, NaBH _4, Rosshoeru salts. These can be used alone or in combination. The concentration of the reducing agent in the electroless plating solution is preferably 0.1 g / liter to 20 g / liter. If more than this,
A metal precipitation reaction is likely to occur in the plating solution, and if it is less than this, the plating metal precipitation reaction on the object to be treated tends to be low. Alkaline agents include NaOH, KOH, Li
A hydroxide of an alkali metal such as OH is preferable, and it is preferable to add it so that the pH of the plating solution becomes 11.0 to 13.0. The complexing agent refers to a substance capable of forming a complex, and specifically, for example, tartrate, EDTA.
(Ethylenediaminetetraacetic acid), NTA (Nitriloacetic acid), HEDTA (Oxyethylethylenediaminetriacetic acid) DHEDDA (Dihydroxyethylethylenediaminediacetic acid), 1,3PDTA (1,3-Propenediaminetetraacetic acid), DTPA (Diethylenetriaminepentaacetic acid) , TTHA (triethylenetetramine hexaacetic acid), H
Examples thereof include compounds such as IMDA (hydroxyethyliminodiacetic acid) and ammonia, which are capable of forming a complex with a metal, particularly with a transition metal such as Cu. It is also preferable to use a stabilizer for the electroless plating solution. Examples of the stabilizer include DDCN (sodium diethyldithiocarbamate), KSCN (potassium thiocyanide),
2,2'-bipyridyl, 2,2'-dipyridine, nicotinic acid, thiourea, tetramethylthiourea, cupron, cuperone, thiazole, 2-mercaptobenzothiazole, potassium ferrocyanide, potassium ferricyanide, sodium cyanide, pyrrole, pyrazole, Imidazole, 1,2,4-triazole, 1,2,4-benzotriazole, thiophene, thiomelide, rhodanine, rubeanic acid, pyridine, triazine, methyl orange, benzoquinoline, 2,2'-biquinoline, dithizone, diphenylcarbazide , Nerocuproine, 2 (2-
Pyridyl) imidazoline, a cyan compound such as 1,10-phenanthroline, a nitrogen-based organic compound, a sulfur compound and the like are preferably added, and these may be used alone or in combination. The concentration of the stabilizer in the electroless plating solution is preferably 0.01 to 100 ppm. If it is more than this, the plating reaction on the object to be treated is likely to stop, and if it is less than this, the plating reaction becomes difficult to occur.

In the present invention, "electronic parts having at least external electrodes on the ceramic body" include chip-shaped ceramic electronic parts, including chip-shaped cylindrical capacitors, chip-shaped resistors, and chip-shaped ferrites. Examples thereof include a bead inductor, an NTC or PTC type chip thermistor, a chip varistor, and a chip multilayer electronic component. Examples of the chip multilayer electronic component include a chip multilayer ceramic capacitor, a chip multilayer ceramic inductor, and a chip multilayer. Examples thereof include a ceramic transformer and a chip-shaped multilayer ceramic LC component (multilayer LC chip component). It should be noted that the "electronic component" may be "an electronic component having a circuit that has a built-in capacitor and an inductor and that electrically connects between the external electrodes and a circuit that electrically cuts off DC current". In the present invention, the “ceramic element body” refers to a body mainly composed of a fired body of a ceramic material. When an electronic component using this is a thermistor, it is a resistor body, and when it is a ferrite bead, it is a conductor magnetic body. In the case of a cover, a laminated ceramic capacitor, a laminated body in which ceramic layers are laminated with an internal electrode sandwiched, in the case of a laminated ceramic inductor, a laminated ceramic transformer, a laminated body in which ceramic layers are laminated with an internal conductor sandwiched. The ceramic element body of the part also conforms to these.

In the present invention, "having at least external electrodes on the ceramic body" means not only the case where external electrodes are provided on both ends of the ceramic body, but also an insulating film is formed on the ceramic body between the external electrodes. This is also the case when they have. The external electrode preferably has at least a base layer of a conductive layer formed on the ceramic body and a surface layer of a tin-containing plating layer, and further preferably has an intermediate layer therebetween. The intermediate layer is provided when the tin-containing plating layer is directly provided on the underlayer to cause "solder erosion" phenomenon,
The underlayer may be an electroless plating film itself, but may be a coating film of a conductive paste containing a conductor powder, and a metal layer can be formed on the surface of a defective conductor such as a vapor deposition film, an ion plating film, a sputtering film, etc. Can be used. These films include Au, Ag, Pd, A
Metallic materials such as g-Pd, Cu, Zn, Ni and their alloys can be used. In addition, in order to selectively form the electroless plated film on both ends of the ceramic body, the electroless plated film can be formed only on that part by performing activation treatment on the corresponding part. As the activation treatment, when electroless nickel plating is performed, the treatment is performed with a solution of Sn, Pd, etc. (sequential immersion in tin chloride solution, palladium chloride solution, etc.) Can be treated by using a solution of sodium hypophosphite, formalin or the like, and immersing the solution in the solution.

Generally, a base layer of a conductive layer formed of a baked film of a conductive material paste film of Ag, Ag-Pd or Pd,
A structure in which an intermediate layer of a plating film containing Cu, Ni or Pd as a main component, and a tin-containing plating layer on the intermediate layer, and the tin-containing plating layer is exposed, or Cu, Ni or P
There is an electrode having a structure in which a tin-containing plating layer is formed on a base layer made of a baked film of a conductive material paste film containing a conductor containing d as a main component, and the tin-containing plating layer is exposed. Not limited to The tin-containing plating layer is a plating layer containing only Sn as a main component, and the main component containing Sn and Pb is S.
The solder plating layer of n / Pb = 85-98 / 2-15 is mentioned.

In the present invention, "at least one layer of a plurality of conductive layers" means, for example, at least one layer of the above-mentioned underlayer, intermediate layer, and tin-containing plating layer when the surface layer is provided, and therefore Examples include a single layer, any two layers, or all layers. At least one of the layers may be an electroless plated film according to the present invention, other layers may be provided with a thick film conductive film made of the above material as a base layer, and other layers except the base layer may be electroplated films. However, an electroless plating film is preferable. In any case, even if the underlayer has irregularities, it is possible to make the film thickness constant by providing an electroless plating film on it, and especially for the underlayer, a thick film made of a nickel baking film is used. An electroless solder plating solution that, when provided and plated with electroless copper and further electroless solder plated, has a small number of steps and that chemically replaces the copper of the electroless copper plating with the solder to deposit the solder. Can be used, which is preferable. Since electroless copper plating has good plating properties, it is preferable because it is unlikely to be affected by the material and surface condition of the underlying thick film. The deposition of electroless solder plating on the copper plating film is based on the principle of a galvanic cell composed of tin, a lead alloy and copper. tin,
Although copper is the most noble in a system in which metal ions of lead and copper exist as an acocomplex, the presence of a complexing agent significantly changes the equilibrium potential and spontaneous potential of these metals, making copper the least base. Can be done. In such a state, tin and lead are deposited on the surface of copper by the following substitution reaction. 2Cu → 2Cu ⁺ + 2e Sn ²⁺ (Pb ²⁺ ) + 2e → Sn (Pb)

Further, in the present invention, "heat treated"
Means, for example, when an electroless solder plating film is obtained by a substitution reaction with an electroless copper plating film as a base, the plating film is slightly lacking in denseness. This refers to modifying the electroless plating film by heating, such as melting and densifying the solder plating film. The heating atmosphere is preferably a non-oxidizing atmosphere in order to prevent the electroless solder plating film from being oxidized. It does not matter whether it is in a gas, a vacuum, a liquid or the like as long as it is a non-oxidizing atmosphere. Further, the heating temperature needs to be changed according to the ratio of tin and lead in the electroless solder plating film. When the amount of tin is large, a heat treatment at a higher temperature is necessary, and when it is close to the eutectic solder composition, a heat treatment at a lower temperature is preferable. When the heating temperature exceeds 300 ° C., evaporation of tin occurs, and when the heating temperature is lower than 100 ° C., the film cannot be densified, so 100 to 300 ° C. is preferable. The heating time is preferably 10 minutes to 60 minutes.

[0014]

For example, in electroless copper plating, copper ions are reduced by the following reaction and metallic copper is deposited on the surface of the object to be treated. CuSO ₄ + 2HCHO + 4NaOH → Cu + 2H ₂ O
+ 2HCOONa + Na ₂ SO _{4 From} this equation, Cu deposition shows that even if an underlying layer of a nickel-baked conductive film is formed on the surface of the object to be processed and irregularities are formed on the surface, the current density in the case of electrolytic plating is As compared with the case where the thickness of the plating film varies depending on the variation, there is no local selectivity, and an electroless copper plating film having a relatively uniform thickness can be obtained. Further, when the tin-containing plating film is provided on the electroless plating film having a uniform thickness,
The variation in the film thickness can be reduced, and the wettability with respect to the molten solder, that is, the solder wettability can be improved. In particular, by changing the tin-containing plating film to the electroless plating film, the variation in the film thickness can be further reduced, and the solder wettability can be improved. It can be further improved. The electroless plated film of the tin-containing plated film is densified by heat treatment, and the solder wettability is further improved.

[0015]

EXAMPLES Examples of the present invention will be described below. Example 1 (a) As shown in FIG. 1, a nickel conductive paste prepared by kneading nickel powder with ethyl cellulose and terpineol was dipped on both ends of a ceramic body 3 in which internal electrodes 1 and ceramic dielectrics 2 were alternately laminated. Method and then dry the nickel conductive paste film at 800 ℃
To form a baked conductive film 4 having a film thickness of 15 μm.
In this way, a test piece having a baked conductive film formed on the ceramic body was prepared. (B) Next, an electroless copper plating solution having the following composition was prepared. CuSO ₄ .5H ₂ O 8.75 g / l (liter) Rochelle salt 37.50 g / l NaOH 11.30 g / l formaldehyde 8.5 ml / l The test piece was dipped in this for 43 minutes at 43 ° C. An electroless copper plated film 5 having a film thickness of about 1 μm was formed on the film 4. (C) The electroless copper-plated film of the test piece was degreased with an alkaline solution and then washed with acid, and then a soft etching treatment for removing oxides on the surface (sulfuric acid 16 g / L (liter) and sodium persulfate 20 g The solution is dissolved in an aqueous solution of / L). Then, the test piece was dipped in an electroless solder plating solution (beam solder Pc-RBL-41 manufactured by Uemura Kogyo Co., Ltd.) at 70 ° C. for 30 minutes to form an electroless solder plating film of about 2 μm.

In this way, the conductive film 4 (film thickness 15 μm) and the electroless copper plating film 5 are baked on both ends of the ceramic body 3.
2.0 × 1. Having external electrodes 7 made of electroless solder plating film 6 (film thickness of about 2 μm) and electroless solder plating film 6 (film thickness of about 2 μm).
A test piece of a 25 × 1.25 (mm) shape chip-shaped multilayer ceramic capacitor was prepared. With respect to the external electrodes of this test piece, the wettability of solder was measured by the meniscograph method described later. As a result, the zero cross time, which is an index of solder wettability, was 0.77 seconds. The value was comparable to 0.75 seconds of a similar conventional product (thick film of nickel, electrolytic copper plating and electrolytic nickel plating were sequentially performed and then electrolytic solder plating was performed). When the electroless solder plating film of the external electrode of this test piece was observed from the surface with an electron microscope, a thin copper plating layer was observed through the solder plating layer, but the wettability of the solder was not affected. .

The meniscograph method is a time until the external electrode of the test piece is gradually pushed into the molten solder at 230 ° C. until the test piece overcomes the buoyancy of the molten solder and penetrates (also called wetting time, zero cross time). ) Is measured. The average value of the wetting time is obtained for 10 test pieces. The shorter the wetting time, the better the solder wettability.

Example 2 Regarding the laminated LC chip component having the circuit-isolated external electrode 20 as shown in FIG.
A silver conductive paste prepared by kneading silver powder with ethyl cellulose and terpineol was applied to a portion of the ceramic body corresponding to 0 by a printing method and dried, and the silver conductive paste film was baked at 800 ° C. to have a thickness of 15 μm. A baking conductive film was formed respectively. The thus obtained test piece was added to a commercially available electroless nickel plating solution (manufactured by Uemura Industry Co., Ltd.).
It was immersed at 30 ° C. for 30 minutes to form a 1.5 μm electroless nickel film. Further, the test piece on which the electroless nickel plating film was formed was subjected to electroless copper plating in the same manner as in Example 1,
An electroless copper plating film of about 2 μm was formed. Hereinafter, an electroless solder plating film was formed on the electroless copper plating film in the same manner as in Example 1 to prepare a test piece of a laminated LC chip component having the external electrodes 17 to 20 shown in FIG. When the solder wettability of this test piece was measured by the meniscograph method as in Example 1, the zero cross time was 0.
It was 79 seconds. It is comparable to 0.75 seconds of similar conventional products (electroless nickel plating, electroless copper plating, electroless solder plating performed by electrolytic nickel plating, electrolytic copper plating, and electrolytic solder plating, respectively). It was In addition, regarding this test piece, each external electrode 17-2
The cross section of No. 0 was observed with an electron microscope, and the total thickness of the electroless nickel plating film, the electroless copper plating film and the electroless solder plating film was found by changing the same number for each external electrode and changing the place, and showed variations. Standard deviation is 4 compared to the conventional product
It was found that the reduction was 2%, and the variation in the plating film thickness was significantly reduced. From this, the structure of "external electrode having a plating film capable of reducing the standard deviation of the thickness of the plating film having the electroless plating film by up to 40% of the standard deviation of the thickness of the plating film having the electrolytic plating film" Can be considered.

Example 3 In the same manner as in Example 1, 2.0 × 1.25 × 1.25
(Mm) shaped chip-shaped monolithic ceramic capacitor test pieces were prepared, and the test pieces were further heated in oil at 210 ° C. for 15 minutes.
Heat treatment was performed for a second. The thickness of the electroless solder-plated film of the obtained test piece was about 1.8 μm. With respect to this test piece as well, when the solder wettability was measured by the meniscograph method as in Example 1, the zero cross time was 0.60.
It was seconds. Similar conventional products (electroless nickel plating, electroless copper plating, electroless solder plating performed by electrolytic nickel plating, electrolytic copper plating, and electrolytic solder plating, respectively)
Was 0.75 seconds, which was a good value.

[0020]

According to the present invention, since at least one of the plurality of conductive layers of the external electrodes is formed by the electroless plating film, the variation in the thickness of the electroless plating film is reduced and so-called throwing power is improved. It is possible to improve the film quality, to make the film thickness relatively uniform, and to form the plating film provided thereon with a uniform and uniform thickness. Therefore, even if an underlayer of a baked conductive film of nickel is formed on the surface of the object to be processed and unevenness is formed on the surface, the film thickness of the electroless plating film formed thereon can be made uniform, The thickness of the tin-containing plating layer provided on the surface can be made uniform, and even when soldering a chip-shaped electronic component equipped with an external electrode having an electroless plating film to a printed circuit board, wetting by molten solder, that is, solder wettability The solder wettability can be further improved by heat-treating the electroless solder plating layer. In addition, as in the case of performing electrolytic plating, the number of steps is not increased such that a copper plating film and a nickel plating film are sequentially provided on a base layer of a nickel-baked conductive film and then an electrolytic solder plating film is provided thereon. In the extreme case, for example, the external electrode of the multilayer capacitor is formed by directly providing the electroless solder plating film on the copper plating film on the nickel baking film or the thick film made of the copper baking film. And the process can be further simplified, which is advantageous in terms of cost. Further, even if the electronic component is an electronic component having multi-terminal external electrodes, such as a laminated LC chip component, and is electrically isolated within the circuit, such as an external electrode for a capacitor, the external electrode is subjected to barrel electrolytic plating. There is no need to say that the thickness of the plating film of the external electrode differs depending on whether the internal element is an inductor or a capacitor as in the case of forming it, and the same film thickness as the external electrode for other inductors. It is possible to form a non-electrolytic plating film of (3), reduce variations in film thickness of the entire external electrode, and supply a product of stable quality.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a chip-shaped monolithic ceramic capacitor provided with an external electrode having an electroless plating film according to the present invention.

FIG. 2 is a T-type LC circuit diagram.

FIG. 3 is a laminated LC chip component incorporating the circuit.

[Explanation of symbols]

 1 Ceramic Dielectric Layer 2 Internal Electrode 3 Ceramic Element 4 Baking Conductive Film 5 Electroless Copper Plating Film 6 Electroless Solder Plating Film 7 External Electrode

Claims (5)

[Claims] 1. A method of manufacturing an electronic component having an external electrode on at least a ceramic body, wherein the external electrode has a plurality of conductive layers having a base layer and a tin-containing plating layer as a surface layer, and the plurality of conductive layers. At least one layer is formed by an electroless plating film forming step. 2. A method of manufacturing an electronic component having an external electrode on at least a ceramic body, wherein the external electrode has a plurality of conductive layers having a base layer and a tin-containing plating layer as a surface layer, and the plurality of conductive layers. At least one layer is formed by an electroless plating film forming step, and the tin-containing plating layer is formed by an electroless plating film forming step and heat-treated. 3. A method for manufacturing an electronic component having an external electrode on at least a ceramic body, wherein the external electrode has three layers of an underlayer, a surface layer of a tin-containing plating layer, and an intermediate layer of both layers. Is a method of manufacturing an electronic component with an electroless plating film formed by an electroless copper plating film forming step. 4. A method of manufacturing an electronic component having an external electrode on at least a ceramic body, wherein the external electrode has three layers of a base layer, a surface layer of a tin-containing plating layer, and an intermediate layer of both layers. Is a method for manufacturing an electronic component with an electroless plated film, which is formed by an electroless copper plated film forming step, and a tin-containing plated layer is formed by a non-electrolytic plated film forming step and heat-treated. 5. The method for manufacturing an electronic component with an electroless plating film according to claim 1, wherein the underlayer is a thick film formed by a coating film.