JP2012049187A - Ceramic multi-layer substrate and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic multi-layer substrate, capable of preventing occurrence of a solder void and a short-circuit failure caused thereby, when a surface-mount component is mounted by soldering, and a manufacturing method of the same.SOLUTION: In the ceramic multi-layer substrate having an external electrode 4 formed of a sintered metal, a plated metal layer 11 is formed in a prescribed surface area of the external electrode 4. On a portion of the surface of the external electrode 4, the plated metal layer is not formed, so that gas such as steam is efficiently ejected from the external electrode area not having the formed plated metal layer. A portion of the external electrode is coated by a porous layer, formed of a nonorganic insulation material to which the plated metal layer is not attached on the surface, and the plated metal layer is formed only in the surface area of the external electrode having no disposition of the porous layer, so that gas such as steam is efficiently ejected from the area having the porous layer formed thereon. The external electrode is a porous electrode formed of a sintered metal including ceramic particles.

Description

  The present invention relates to a ceramic multilayer substrate and a method for manufacturing the same, and more particularly to a ceramic multilayer substrate including an external electrode on which a surface mount component is mounted and a method for manufacturing the same.

In recent years, ceramic multilayer substrates in which wiring conductors are arranged three-dimensionally have been widely used for various applications.
Such a ceramic multilayer substrate usually includes an external electrode on which an electronic component (surface mount component) is mounted.
And in order to improve the mounting reliability of the surface mounting components mounted by methods, such as reflow soldering, it is performing to improve characteristics, such as solder wettability, by plating to an external electrode.

  As one of such ceramic multilayer substrates, there has been proposed a ceramic multilayer substrate in which a surface-mounted component is mounted on an external electrode having a plating film formed on the surface thereof. (See Patent Document 1, paragraphs 0039 and 0043, etc.).

However, in the case of the ceramic multilayer substrate of Patent Document 1, moisture derived from the plating solution used when plating the external electrode or the cleaning water used in the cleaning step remains in the manufacturing process.
Therefore, when the ceramic multilayer substrate is heated in the mounting process using solder when mounting the surface mount component on the external electrode, the internal moisture evaporates and vaporizes and passes through the external electrode and melts. There is a problem that solder voids enter the solder and generate solder voids.
When solder voids are generated, there is a problem that short-circuit defects occur between adjacent external electrodes due to expansion of the solder volume.

  In addition, the gas (water vapor) in which moisture has evaporated passes through the external electrode and enters the solder. The external electrode made of sintered metal formed by baking the conductive paste is easy to infiltrate the gas. However, it passes through the plating film and reaches the solder existing on the surface. In addition, although the plating film is difficult to pass a gas, since it is thin, it passes through the plating film and reaches the molten solder existing on the plating film in a situation where it is difficult to discharge from other regions.

International Publication WO2006 / 027888

  The present invention solves the above problems, and when mounting a surface mount component on an external electrode of a ceramic multilayer substrate, generation of solder voids due to gas passing through the external electrode, resulting in occurrence of short circuit failure It is an object of the present invention to provide a ceramic multilayer substrate and a method for manufacturing the same that can suppress and prevent the above.

In order to solve the above problems, the ceramic multilayer substrate of the present invention comprises:
A substrate having a plurality of laminated ceramic layers;
An external electrode made of sintered metal, formed on the main surface of the substrate, on which a surface mount component is mounted;
And a plated metal layer formed so as to cover a predetermined region excluding a partial region on the surface of the external electrode.

The ceramic multilayer substrate of the present invention is
A substrate having a plurality of laminated ceramic layers;
An external electrode made of sintered metal, formed on the main surface of the substrate, on which a surface mount component is mounted;
A porous layer made of an inorganic insulating material, which is disposed so as to cover a partial region of the surface of the external electrode, and to which the plated metal layer does not adhere to the surface;
And a plated metal layer formed in a region where the porous layer is not provided on the surface of the external electrode.

  The external electrode is preferably a porous external electrode made of a sintered metal containing ceramic particles.

  Further, it is preferable that the external electrode is embedded in the substrate in such a manner that the main surface is exposed, and the plated metal layer is formed so as to cover a predetermined region of the exposed main surface. .

The method for producing the ceramic multilayer substrate of the present invention comprises:
A substrate having a plurality of laminated ceramic layers, an external electrode made of sintered metal, formed on the main surface of the substrate and mounted with a surface mount component thereon, and a part of the surface of the external electrode A method for producing a ceramic multilayer substrate comprising a plated metal layer formed so as to cover a predetermined region excluding a region,
Forming the external electrode made of sintered metal on the substrate;
By applying a resist to a predetermined region of the external electrode and performing plating, the resist of the external electrode is applied while preventing the plating metal layer from being formed in the region of the external electrode where the resist is applied. And a step of forming the plated metal layer in a region that is not present.

The method for producing the ceramic multilayer substrate of the present invention comprises:
A substrate having a plurality of laminated ceramic layers, an external electrode made of sintered metal, formed on the main surface of the substrate and mounted with a surface mount component thereon, and a part of the surface of the external electrode A method for producing a ceramic multilayer substrate comprising a plated metal layer formed so as to cover a predetermined region excluding a region,
Forming the external electrode made of sintered metal on the substrate;
Forming a plated metal layer on the entire surface of the external electrode, and then removing a part of the plated metal layer to expose a part of the external electrode.

Moreover, the method for producing the ceramic multilayer substrate of the present invention includes:
A substrate having a plurality of laminated ceramic layers, an external electrode made of sintered metal, formed on the main surface of the substrate and mounted with a surface mount component thereon, and a part of the surface of the external electrode A porous layer made of an inorganic insulating material, which is disposed so as to cover the region and does not adhere to the plated metal layer, and a region on the surface of the external electrode where the porous layer is not disposed. A method for producing a ceramic multilayer substrate comprising a plated metal layer,
The porous electrode made of an inorganic insulating material to which the plated metal layer does not adhere so that the external electrode made of sintered metal is disposed on the surface of the substrate and covers a partial region of the surface of the external electrode Forming a structure in which the layers are disposed;
And plating the external electrode to form a plated metal layer in a region not covered by the porous layer of the external electrode.

  In the step of forming the external electrode, it is preferable to form a porous external electrode made of a sintered metal containing ceramic particles.

  In the ceramic multilayer substrate of the present invention, a plated metal layer is provided on the external electrode in a region excluding a part of the external electrode made of sintered metal formed on the main surface of the substrate to expose a part of the external electrode. Since it does in this way, gas, such as water vapor | steam, can be efficiently discharged | emitted from the exposed part which is not covered with the metal plating layer of an external electrode. As a result, the generation of short-circuit defects is effectively prevented by suppressing and preventing the generation of solder voids caused by gas such as water vapor entering the solder existing on the plated metal layer formed on the surface of the external electrode. It becomes possible.

  In addition, a porous layer where the plated metal layer does not adhere to the surface is disposed so as to cover a part of the surface of the external electrode, while the porous layer made of an inorganic insulating material is not disposed in the region. Even when a plated metal layer is arranged, it is possible to efficiently discharge gas such as water vapor from the inside through the porous layer to the outside, suppressing and preventing the generation of solder voids. Thus, it is possible to efficiently prevent the occurrence of short circuit defects.

  When a part of the surface of the external electrode is covered with a porous layer made of an inorganic insulating material, when the surface of the external electrode is plated by immersing the ceramic multilayer substrate in a plating bath, Even if a resist or the like is not used, the plating metal layer is not formed on the surface of the porous layer, which is significant in that the plating process in the manufacturing process can be simplified.

  In addition, by forming a porous external electrode made of sintered metal containing ceramic particles as the external electrode, gas can be discharged more reliably from the portion of the external electrode that is not covered with the plated metal layer. Thus, the present invention can be further effectively realized.

  In addition, the external electrode is embedded in the substrate in such a manner that the main surface is exposed, and the plated metal layer is formed so as to cover other regions without forming the plated metal layer in a predetermined region of the exposed main surface. Thus, for example, even when the external electrode is flush with the main surface of the ceramic substrate to form a ceramic multilayer substrate with a high flatness of the main surface, the inside of the solder applied on the plating film It is possible to suppress and prevent the generation of solder voids due to the entry of gas such as water vapor into the substrate, thereby efficiently preventing the occurrence of short circuit defects.

  In the method for producing a ceramic multilayer substrate of the present invention, an external electrode made of sintered metal is formed on the substrate, and then a resist is applied to a predetermined position of the external electrode and plating is performed. It is possible to reliably form the plating metal layer in the region where the resist of the external electrode is not applied while preventing the plating metal layer from being formed in the applied region. Therefore, it is possible to efficiently discharge gas such as water vapor from the exposed part that is not covered with the plated metal layer of the external electrode, and suppress the generation of solder voids due to gas such as water vapor entering the inside of the solder. Therefore, it is possible to efficiently manufacture a highly reliable ceramic multilayer substrate that can prevent the occurrence of short-circuit defects.

  Moreover, after forming a plating metal layer on the entire surface of the external electrode made of sintered metal formed on the substrate, as in another method for manufacturing a ceramic multilayer substrate of the present invention, a part of the plating metal layer is removed. Even when a part of the external electrode is exposed, an external electrode having a region where the plating metal layer is not formed and a gas such as water vapor is easily discharged (region not covered by the plating metal layer) is provided. A highly reliable ceramic multilayer that can be efficiently formed and suppresses the generation of solder voids caused by gas such as water vapor entering the solder, thereby preventing the occurrence of short circuits. A board | substrate can be manufactured efficiently.

  Further, as in another method for manufacturing a ceramic multilayer substrate of the present invention, an external electrode made of sintered metal is disposed on the surface of the substrate, and a part of the surface of the external electrode is covered. After forming a structure in which a porous layer made of an inorganic insulating material to which the plated metal layer does not adhere is disposed, the external electrode is plated, and the plated metal is applied to the region not covered by the porous layer of the external electrode When a layer is formed, gas such as water vapor can be efficiently discharged from the porous layer, and generation of solder voids due to gas such as water vapor entering the inside of the solder is suppressed. Therefore, it is possible to efficiently manufacture a highly reliable ceramic multilayer substrate capable of preventing the occurrence of a short circuit failure due to the above.

  Also, in the step of forming the external electrode, by forming a porous external electrode made of a sintered metal containing ceramic particles, the area of the external electrode that is not covered with the plated metal layer or the porous layer is plated. The gas can be discharged more reliably from the region not covered with the metal layer, and the present invention can be further effectively realized.

It is a figure which shows the structure of the ceramic multilayer substrate concerning the Example (Example 1) of this invention. It is a figure which shows the principal part structure of the ceramic multilayer substrate concerning Example 1 of this invention. (a), (b) is a figure explaining the manufacturing method of the ceramic multilayer substrate concerning Example 1 of this invention shown to FIG. 1 and 2. FIG. It is a figure which shows the state from which the gas is discharged | emitted from the area | region in which the plating metal layer of an external electrode is not formed in the ceramic multilayer substrate concerning Example 1 of this invention. It is a figure which shows typically the structure of the conventional ceramic multilayer substrate in which the plating metal layer was formed in the whole surface of an external electrode. (a), (b) is a figure explaining the manufacturing method of the ceramic multilayer substrate concerning the other Example (Example 2) of this invention shown in FIG. It is a figure which shows the principal part structure of the ceramic multilayer substrate concerning further another Example (Example 3) of this invention. It is a figure explaining the manufacturing method of the ceramic multilayer substrate concerning Example 3 of this invention shown in FIG.

  Examples of the present invention will be described below to describe the features of the present invention in more detail.

  FIG. 1 is a sectional view showing a configuration of a ceramic multilayer substrate according to an embodiment of the present invention, and FIG. 2 is a diagram schematically showing an enlarged main part thereof.

  As shown in FIG. 1, a ceramic multilayer substrate A of Example 1 includes a substrate 2 formed by laminating a plurality of ceramic layers 1 as a base layer, internal conductors 3 disposed between the layers, and a surface. A formed external electrode 4 and a via-hole conductor 5 for interlayer connection are provided. The internal conductor 3 and the external electrode 4 arranged in different layers are electrically connected to each other through the via-hole conductor 5.

The external electrode 4 on which the surface-mounted component 6 is mounted via the solder 8 is embedded in the substrate 2 and formed so that the upper surface thereof is substantially flush with the upper surface of the substrate 2.
In the ceramic multilayer substrate A of Example 1, the external electrode 4 is a porous electrode formed from a sintered metal containing ceramic particles.

In Example 1, a sintered external metal (Cu sintered metal) containing ceramic particles (Al ₂ O ₃ (alumina) particles in this example) is used so that a porous external electrode 4 can be formed. An external electrode is formed.

  Further, in the ceramic multilayer substrate A of Example 1, a plated metal layer 11 is disposed on the surface of the external electrode 4 as shown in FIG. Although not particularly shown, the plated metal layer 11 has a two-layer structure including a Ni plated layer as a base layer and an Au plated layer formed thereon.

  The plated metal layer 11 is formed on the central portion 4c excluding a part of the surface of the external electrode 4 (both end portions 4a and 4b in FIG. 2), and both end portions 4a and 4b of the external electrode 4 are exposed. Yes.

  In the ceramic multilayer substrate A of Example 1, the external electrode 4 is a porous electrode formed of a sintered metal containing ceramic particles, and both end portions 4a and 4b of the external electrode 4 are plated metal layers. 11 is exposed to the outside and is configured to be able to efficiently pass a gas such as water vapor from the inside of the substrate 2 to be discharged to the outside.

Next, a method for manufacturing the ceramic multilayer substrate A will be described.
(1) Production of unfired laminated body In producing the ceramic multilayer substrate A, first, a plurality of ceramic green sheets for a substrate to be the ceramic layer 1 are prepared.

  Next, a through hole for disposing the via-hole conductor 5 is formed in a predetermined ceramic green sheet for a substrate. Then, the via hole conductor 5 is formed by filling the through hole with a conductive paste.

Further, a conductive film to be an internal conductor or an external electrode is formed by printing a conductive paste in a predetermined pattern on a predetermined ceramic green sheet for a substrate.
In Example 1, a conductive paste mainly composed of Cu powder and Al ₂ O ₃ powder is applied to the conductor film serving as the external electrode so that a sufficiently porous external electrode can be formed. By doing so, a conductor film is formed.
On the other hand, as the conductor film serving as the internal conductor, a conductor film is formed using a Cu paste not containing Al ₂ O ₃ powder. However, there is no special restriction on the type of conductive paste for forming the inner conductor.

  Next, as described above, the base-material ceramic green sheet on which the via-hole conductor and / or conductor film is formed and the base-material ceramic green sheet on which the via-hole conductor and conductor film are not formed are laminated in a predetermined order. The laminated body which becomes the ceramic multilayer substrate A as shown in FIG. In addition, in crimping | bonding said laminated body, the method of an isostatic press is used, for example.

(2) Firing of Laminate Next, the pressure-bonded laminate produced as described above is degreased and then fired at a temperature at which the ceramic material powder constituting the ceramic green sheet for a substrate is sintered.
Thus, the laminate having a porous outer electrode made of a Cu sintered metal containing Al ₂ O ₃ particles (sintered body) is obtained.

  In firing the laminate, in order to suppress or prevent shrinkage in a direction parallel to the main surface of the laminate, at least one main surface of the laminate is substantially sintered at the firing temperature of the laminate. A shrinkage suppression layer (restraint layer) made of a material that is not used may be disposed and fired.

(3) Formation of plating metal layer on external electrode Then, Ni plating and Au plating are applied to the porous external electrode of the fired laminate, and a Ni plating layer as a base layer is formed on the surface of the external electrode; A plated metal layer 11 having a two-layer structure (not shown) of an Au plating layer formed thereon is formed.

  At this time, as shown in FIG. 3A, a resist agent 12 is applied onto both end portions 4a and 4b of the external electrode 4, the central portion 4c of the external electrode 4 is exposed, and both end portions 4a and 4b are In the state of being coated with the resist agent 12, first, Ni plating is performed by the electroless plating method, and then Au plating is performed. As shown in FIG. 3B, Ni is formed on the central portion 4 c of the external electrode 4. A plated metal layer 11 having a two-layer structure (not shown) of a plated layer and an Au plated layer formed thereon is formed.

Then, by removing the resist agent 12, both end portions 4a and 4b of the external electrode 4 are exposed as shown in FIG.
As a result, as shown in FIG. 2, both end portions 4a and 4b of the external electrode 4 are exposed, and a ceramic multilayer substrate A having a structure in which the plated metal layer 11 is formed on the central portion 4c is obtained.

(4) Mounting of surface mount component The surface mount component 6 is mounted on the ceramic multilayer substrate A by a reflow soldering method.
In the ceramic multilayer substrate A of this embodiment, as shown in FIG. 2, the plated metal layer 11 is provided at the central portion 4c of the external electrode 4, while a part of the external electrode 4 (both end portions 4a and 4b) is exposed. Therefore, as shown in FIG. 4, when the surface mount component 6 is mounted using the solder 8, the both ends 4a and 4b not covered with the plating metal layer of the external electrode 4 are used in the plating process or the like. Gases such as water vapor generated by evaporation of moisture that has entered the substrate 2 are efficiently discharged. As a result, it is possible to suppress the occurrence of short-circuit defects by suppressing the generation of solder voids caused by gas such as water vapor entering the solder 8 applied on the plated metal layer 11.

In the ceramic multilayer substrate A of Example 1, a porous electrode made of a sintered metal containing ceramic particles (Al ₂ O ₃ particles) is formed as the external electrode 4. The gas can be more reliably discharged from both end portions 4a and 4b that are not covered with the plated metal layer 11.

<Short incidence>
In addition, as shown in FIG. 2, the plated metal layer 11 is provided in the central portion 4c of the external electrode 4, while a part of the external electrode 4 (both end portions 4a and 4b) is exposed. For a ceramic multilayer substrate A and a conventional ceramic multilayer substrate having a structure in which the entire surface of the external electrode 4 is covered with a plated metal layer 11 as shown in FIG. The state of occurrence of short circuit failure was compared.

As a result, in the case of the conventional ceramic multilayer substrate of FIG. 5, solder voids were generated, and out of 76 samples subjected to the test, occurrence of short-circuit defects was observed in 44 samples.
On the other hand, in the case of the ceramic multilayer substrate A of the present invention, as shown in FIG. 4, it penetrated into the substrate 2 in the plating process or the like from both end portions 4a and 4b not covered with the plating metal layer of the external electrode 4. Since gas such as water vapor generated by evaporation of water was efficiently discharged, no occurrence of short circuit was observed in any of the 76 samples used in the test.

  Further, in the ceramic multilayer substrate A of Example 1, the external electrode 4 is embedded in the substrate 2, the upper surface of the external electrode 4 is substantially flush with the main surface of the substrate 2, and both end portions of the exposed main surface are Since no plated metal layer is formed on 4a and 4b, but the plated metal layer 11 is formed on the central portion 4c, it is possible to obtain a highly reliable ceramic multilayer substrate with excellent flatness of the main surface. it can.

  The area of the portion of the external electrode 4 that is not covered with the plated metal layer is usually preferably 25 to 50% of the surface area of the external electrode. This is because if the proportion of the region where the plated metal layer 11 is disposed becomes too small, the bonding strength of the surface-mounted component 6 is lowered and the mounting reliability is lowered.

  In Example 2, a ceramic multilayer substrate having the same structure as the ceramic multilayer substrate A (FIGS. 1 and 2) of Example 1 was manufactured by the method described below.

  (1) First, the baked substrate 2 was produced by the same method up to the step of firing the laminate of (2) in Example 1 above.

  (2) Then, in this embodiment, the main surface of the external electrode 4 is plated without applying a resist agent, and as shown in FIG. 11 was formed. The plated metal layer 11 is not particularly shown in the figure, as in the case of the ceramic multilayer substrate of Example 1 above, but is a two-layer including an Ni plated layer as an underlayer and an Au plated layer formed thereon. It has a structure.

(3) Next, as shown in FIG. 6B, after the mask 13 is applied to the central portion 4c of the external electrode 4, a blast process is performed, and the plated metal on both end portions 4a and 4b of the external electrode 4 Layer 11 was removed.
As a result, as shown in FIG. 2, both end portions 4a and 4b of the external electrode 4 of the external electrode 4 are exposed, and a ceramic multilayer substrate having a structure in which the plated metal layer 11 is formed on the central portion 4c is obtained. .

  Similarly to the ceramic multilayer substrate A of Example 1 described above, the ceramic multilayer substrate of Example 2 manufactured in this way also has a gas such as water vapor from the exposed ends that are not covered with the plated metal layer of the external electrode. Since it is efficiently discharged, it is possible to reliably prevent the occurrence of short-circuit defects by suppressing the generation of solder voids due to the entry of gas such as water vapor into the solder during the mounting of surface-mounted components.

  For the ceramic multilayer substrate of Example 2, surface-mounted components were mounted and the occurrence of short-circuit failure was examined, but no occurrence of short-circuit failure was observed in any of the 76 samples used for the test. It was.

FIG. 7 is a cross-sectional view showing a main part of the ceramic multilayer substrate A1 according to Example 3 of the present invention.
In the ceramic multilayer substrate A1 of this Example 3, an inorganic insulating material (with no plated metal layer adhering to the surface so as to cover a predetermined region on the surface of the external electrode 4 (both ends 4a and 4b in this Example 3) In Example 3, porous layers 14a and 14b made of Al ₂ O ₃ (alumina) are provided, and regions where the porous layers 14a and 14b made of an inorganic insulating material are not provided (central portion 4c). ) Is provided with a plated metal layer 11 having a two-layer structure (not shown) of an Ni plating layer and an Au plating layer formed thereon.

The ceramic multilayer substrate A1 of Example 3 can be manufactured, for example, by the method described below.
(1) First, by a method according to the steps (1) and (2) of Example 1, a step of laminating, press-bonding and firing predetermined ceramic green sheets for a substrate, as shown in FIG. A fired laminate in which porous layers 14a and 14b made of an inorganic insulating material to which a plated metal layer does not adhere are disposed on the surface so as to cover predetermined regions (both ends 4a and 4b) on the surface of the external electrode 4. A body (substrate) 2 is formed.

The porous layers 14a and 14b are formed, for example, by forming a conductor layer for an external electrode on a ceramic green sheet for a base material that is the uppermost layer, and using Al ₂ O ₃ powder and an inorganic insulating material at both ends thereof. It can be formed by applying an alumina paste to be laminated, laminating and pressing the ceramic green sheet for a substrate together with other ceramic green sheets, and then firing the obtained unfired laminate.

  However, the formation method of the porous layers 14a and 14b is not particularly limited, and can be formed by other methods. For example, it can be formed by a method in which an alumina paste is applied to both ends of the external electrode of the fired laminated body and then fired.

  (2) Next, a fired laminate in which porous layers 14a and 14b made of an inorganic insulating material with no plating metal layer attached to the surface are disposed so as to cover both end portions 4a and 4b of the external electrode 4. 2 (FIG. 8) is plated, and a plated metal layer 11 (FIG. 7) having a two-layer structure of an Ni plating layer and an Au plating layer is formed in the central portion 4c where the porous layers 14a and 14b are not disposed. To do.

  As a result, as shown in FIG. 7, the porous layers 14a and 14b formed on the both end portions 4a and 4b of the external electrode 4 are exposed, and the plated metal layer 11 is formed on the central portion 4c. A ceramic multilayer substrate A1 is obtained.

  Similarly to the ceramic multilayer substrate A of Example 1, the ceramic multilayer substrate A1 also efficiently discharges gas such as water vapor through the exposed porous layers 14a and 14b that are not covered with the plated metal layer 11. Therefore, it is possible to suppress the occurrence of short-circuit defects by suppressing the generation of solder voids caused by gas such as water vapor entering the solder used when mounting the surface-mounted component.

  For the ceramic multilayer substrate A1 of Example 3, surface mount components were mounted and the occurrence of short-circuit failure was examined, but no occurrence of short-circuit failure was observed in any of the 76 samples. .

  The ratio of the porous layers 14a and 14b covering the surface of the external electrode 4 is usually preferably 25 to 50% of the surface area of the external electrode. This is because if the proportion of the area covered with the porous layers 14a and 14b of the plated metal layer 11 becomes too large, the bonding strength of the surface-mounted component 6 is lowered and the mounting reliability is lowered.

In each of the above embodiments, in order to form a porous external electrode, an external electrode made of a sintered metal containing alumina particles (Cu sintered metal) is formed as ceramic particles. Porous external electrodes can be formed by adding zirconia (ZrO ₂ ) or the like as particles instead of alumina particles.

Moreover, although the said Example demonstrated the case where the plating metal layer was a plating metal layer which has a 2 layer structure of Ni plating layer which is a base layer, and Au plating layer formed on it as an example, plating The layer structure of the metal layer, the type and combination of metals constituting the plated metal layer are not limited thereto.
In addition to the above Ni and Au, various metals such as tin, solder, Ag, and Cu are exemplified as the metal constituting the plated metal layer.

  In the first and second embodiments, as a method of exposing a predetermined region of the external electrode, a method of performing a plating process by applying a resist agent, and a method of performing a blast process in a state where a mask is applied to the predetermined region. Although the case where it is used has been described, there is no particular restriction on the method of exposing a predetermined region of the external electrode, and for example, a method such as etching or milling can be applied.

In Example 3 described above, a porous layer made of alumina was formed as a porous layer disposed so as to cover a part of the external electrode. However, as a material constituting the porous layer, In addition to alumina, various materials can be used, and preferred examples include zirconia (ZrO ₂ ).

  In the above embodiment, the ceramic multilayer substrate in which the external electrode is embedded in the substrate has been described as an example. However, the external electrode is formed on the surface of the substrate and protrudes from the surface of the substrate by the thickness of the external electrode. In this case, each of the above embodiments can be provided by providing a region in the external electrode that is not covered with the plating metal layer and can efficiently discharge a gas such as water vapor. The same effect as in the case of can be obtained.

  In addition, the present invention is not limited to the above-described embodiments, but the number of ceramic layers constituting the ceramic multilayer substrate, the arrangement of external electrodes and internal conductors, the ceramic layers and internal conductors, and the like. Various applications and modifications can be made within the scope of the invention with respect to the materials constituting the above and the specific conditions in the manufacturing process of the ceramic multilayer substrate.

A, A1 Ceramic multilayer substrate 1 Ceramic layer 2 Substrate 3 Internal conductor 4 External electrode 4a, 4b Both ends of external electrode 4c Central portion of external electrode 5 Via hole conductor 6 Surface mount component 8 Solder 11 Plating metal layer 12 Resist agent 13 Mask 14a 14b Porous layer

Claims (8)

A substrate having a plurality of laminated ceramic layers;
An external electrode made of sintered metal, formed on the main surface of the substrate, on which a surface mount component is mounted;
And a plated metal layer formed so as to cover a predetermined region excluding a partial region on the surface of the external electrode. A substrate having a plurality of laminated ceramic layers;
An external electrode made of sintered metal, formed on the main surface of the substrate, on which a surface mount component is mounted;
A porous layer made of an inorganic insulating material, which is disposed so as to cover a partial region of the surface of the external electrode, and to which the plated metal layer does not adhere to the surface;
And a plated metal layer formed in a region of the surface of the external electrode where the porous layer is not disposed.   3. The ceramic multilayer substrate according to claim 1, wherein the external electrode is a porous electrode made of a sintered metal containing ceramic particles.   The external electrode is embedded in the substrate in such a manner that the main surface is exposed, and the plated metal layer is formed so as to cover a predetermined region of the exposed main surface. The ceramic multilayer substrate according to claim 1. A substrate having a plurality of laminated ceramic layers, an external electrode made of sintered metal, formed on the main surface of the substrate and mounted with a surface mount component thereon, and a part of the surface of the external electrode A method for producing a ceramic multilayer substrate comprising a plated metal layer formed so as to cover a predetermined region excluding a region,
Forming the external electrode made of sintered metal on the substrate;
By applying a resist to a predetermined region of the external electrode and performing plating, the resist of the external electrode is applied while preventing the plating metal layer from being formed in the region of the external electrode where the resist is applied. And a step of forming the plated metal layer in a region that is not formed. A substrate having a plurality of laminated ceramic layers, an external electrode made of sintered metal, formed on the main surface of the substrate and mounted with a surface mount component thereon, and a part of the surface of the external electrode A method for producing a ceramic multilayer substrate comprising a plated metal layer formed so as to cover a predetermined region excluding a region,
Forming the external electrode made of sintered metal on the substrate;
Forming the plated metal layer on the entire surface of the external electrode, and then removing a part of the plated metal layer to expose a part of the external electrode. Method. A substrate having a plurality of laminated ceramic layers, an external electrode made of sintered metal, formed on the main surface of the substrate and mounted with a surface mount component thereon, and a part of the surface of the external electrode A porous layer made of an inorganic insulating material, which is disposed so as to cover the region and does not adhere to the plated metal layer, and a region on the surface of the external electrode where the porous layer is not disposed. A method for producing a ceramic multilayer substrate comprising a plated metal layer,
The porous electrode made of an inorganic insulating material to which the plated metal layer does not adhere so that the external electrode made of sintered metal is disposed on the surface of the substrate and covers a partial region of the surface of the external electrode Forming a structure in which the layers are disposed;
And a step of plating the external electrode to form a plated metal layer in a region not covered with the porous layer of the external electrode.   The method for producing a ceramic multilayer substrate according to claim 5, wherein in the step of forming the external electrode, a porous external electrode made of a sintered metal containing ceramic particles is formed.

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