JP5723577B2 - Manufacturing method of electronic parts - Google Patents

Description

The present invention relates to a method of manufacturing an electronic component, more particularly, from the interface between the surface electrode and the substrate hardly plating solution penetrates, and the surface electrode is hardly peeled off, and the method for manufacturing an electronic component having a high moisture resistance Related.

  In Patent Document 1, external electrodes are formed on both exposed end surfaces of a plurality of internal electrode layers embedded in a ceramic capacitor sintered body to form a multilayer ceramic capacitor element, and a metal copper plate is connected to each of the external electrodes, and the ceramic capacitor An electronic component whose element portion is covered with an insulating resin is described (see claim 1 of FIG. 1 and FIG. 1). In addition, the electronic component disclosed in Patent Document 1 is “a good reflow soldering regardless of the soldering method and conditions because the connection part to the board is a metal plate with good soldering connected to the external electrode” As a matter of course, good flow soldering is possible, and at the same time, the surface of the ceramic sintered body is coated with resin, so there is no collision between parts with a vibration feeder or the impact of the suction nozzle of the chip mounter. The technical effect that “no cracks will occur even if there is” and “there is no restriction when mounting on the board and the characteristic deterioration factor is eliminated, and a highly reliable multilayer ceramic electronic component can be obtained” (See paragraphs 0011 and 0012 of Patent Document 1).

  Furthermore, Patent Document 2 describes an electronic component in which the surface of a solid inductor is formed by a coating layer made of crystallized glass (see Claim 1 of Patent Document 2 and FIG. 1). It is described that the electronic component described in Patent Document 2 has the technical effect of “improvement of the chip surface to improve moisture resistance and prevent infiltration of the electrolytic solution of the electroplating to avoid variation in electrical characteristics”. (See paragraph No. 0006 of Patent Document 2).

  In Patent Document 3, a lid portion is integrated with a laminated portion formed by laminating an internal electrode layer and a ceramic layer, and the via conductor main body portion penetrates the laminated portion and serves as an external terminal formed on the lid portion. There is described a laminated electronic component having a first end face connected and a second end face connected to the via conductor main body and larger than the first end face, and including a via conductor penetrating the lid. (Refer to claim 1 of FIG. 1 and FIG. 1). Further, the multilayer electronic component described in Patent Document 3 suppresses the technical effect that the plating solution can be prevented from entering the interface between the external terminal and the ceramic layer, and the electrical short circuit between the internal electrode layers. It is described that there is a technical effect that it can be performed (see paragraph numbers 0002 to 0005, 0010, and 0043 in Patent Document 3).

  In Patent Documents 4, 5 and 6, a ceramic green sheet is laminated after applying a ceramic paste, a constraining sheet mainly composed of a hardly sinterable inorganic material is laminated, and after firing, the ceramic layer is removed to provide a conductor on the surface. The ceramic substrate obtained by exposing is described (refer to each claim 1 of patent documents 4, 5 and 6 and each FIG. 1). The ceramic substrates described in Patent Documents 4, 5 and 6 have the firing strain while preventing the occurrence of problems such as stamping unnecessary irregularities on the surface conductor, causing foreign matter adhesion, and deterioration of plating properties and solder wettability. Are described as being technically effective (Paragraph No. 0006 column to 0016 column, PTL 5 paragraph number 0006 to 0014 column, PTL 6 paragraph numbers 0006 to 0015). Column).

However, in the present electronic parts, it is required that the plating solution does not enter the interface between the surface electrode and the substrate, and the surface electrode is difficult to peel off and has high moisture resistance.
Further, when manufacturing a wiring board incorporating an electronic component, the surface electrode formed on the surface of the electronic component usually protrudes greatly, so that large irregularities are also formed on the surface of the wiring board. If large irregularities are formed on the surface of the wiring board, poor contact with the electrode terminals connected to the wiring board may occur. Therefore, there has been a demand for a wiring board having a built-in electronic component and small surface irregularities.

Japanese Patent No. 3459186 JP-A-9-283359 JP 2007-48768 A JP 2005-85995 A JP 2005-86017 A JP-A-2005-109462

The problem to be solved by the present invention is that the plating solution is difficult to enter the interface between the surface electrode and the substrate, the surface electrode is difficult to peel off, and a method of manufacturing an electronic component having high moisture resistance, and the surface electrode It is possible to form a metal plating layer by increasing the adhesion with a photoresist film used when performing metal plating for joining external terminals to the surface, thereby producing a method for manufacturing an electronic component with a low occurrence rate of defective products. Is to provide .

As means for solving the problems,
(1) An electronic component comprising a substrate containing a crystalline inorganic compound and a surface electrode present on the surface of the substrate,
A ceramic coating layer that covers a surface of the substrate that is not covered with the surface electrode and covers a surface portion of the edge of the surface electrode; and a surface of the surface electrode that is not covered with the ceramic coating layer directly A method of manufacturing an electronic component having a metal plating layer that covers and covers the edge surface portion of the ceramic coating layer that covers the edge surface portion of the surface electrode ,
Forming a green surface electrode to be the surface electrode on the surface of the green substrate to be the base;
A ceramic coating step of coating a surface of the unfired substrate that is not coated with the unfired surface electrode and an edge surface portion of the unfired surface electrode with a ceramic paste serving as the ceramic coating layer;
A firing step of firing the unfired substrate coated with the ceramic paste;
A metal plating step of covering the surface of the surface electrode obtained by the firing step that is not covered with the ceramic coating layer and the edge surface portion of the ceramic coating layer that covers the edge surface portion of the surface electrode with the metal plating layer When,
A method for manufacturing an electronic component, comprising:
(2) The coating length a of the ceramic coating layer in the direction parallel to the surface of the substrate at the edge surface portion of the surface electrode covered by the ceramic coating layer is the edge of the ceramic coating layer covered by the metal plating layer An electronic component manufacturing method according to (1), wherein an electronic component larger than a coating length b of the metal plating layer in a direction parallel to the surface of the base in the surface portion is manufactured;
(3) The substrate is a laminate in which a conductor layer and a dielectric layer mainly composed of barium titanate are laminated,
The surface electrode is mainly nickel,
The method for producing an electronic component according to (1) or (2), wherein the metal plating layer is a copper-plated layer to produce a laminated electronic component,
(4) A via conductor connecting the conductor layer and the surface electrode in a direction intersecting the surface of the base body,
The via array type multilayer ceramic capacitor in which the via conductors are arranged at equal intervals when the substrate is cut in a plane parallel to the surface of the substrate is manufactured according to (3), Electronic component manufacturing method, and
(5) The electronic component according to any one of (1) to (4), wherein the ceramic coating layer is an electronic component mainly composed of the same material as the crystalline inorganic compound. A manufacturing method can be mentioned.

According to this invention,
(1) Since the edge surface portion of the surface electrode formed on the surface of the substrate is coated with the ceramic coating layer, the surface electrode formed on the substrate surface and the ceramic coating layer are the edge of the surface electrode, that is, the surface. The edge of the surface electrode and the edge of the ceramic coating layer when the edge of the ceramic coating layer, i.e., the edge of the ceramic coating layer from the substrate surface is simply in contact with the rising edge of the electrode from the substrate surface The phenomenon that the plating solution infiltrates toward the substrate from the joint with the part can be prevented,
(2) Since the edge surface portion of the surface electrode is coated with the ceramic coating layer, the edge surface portion of the surface electrode is in a state in which the ceramic coating layer is locked, thereby making it difficult for the surface electrode to peel off from the substrate.
(3) The surface electrode is coated not only with the ceramic coating layer but also with the surface electrode and the edge surface portion of the ceramic coating layer covering the edge surface portion of the surface electrode so as to straddle the boundary between the surface electrode and the ceramic coating layer. Since the metal plating layer to be formed is formed, a path through which moisture existing in the external environment reaches the surface electrode is lengthened, thereby providing a method of manufacturing an electronic component having high moisture resistance.
(4) The electronic components described in JP-A-2005-85995, JP-A-2005-86017, and JP-A-2005-109462 are laminated on a substrate and then laminated with a ceramic green sheet. An electronic component having a structure in which a ceramic sheet is removed in order to expose a surface electrode after firing after laminating a restraint sheet mainly composed of a flammable inorganic material and the surface of the electronic component has an uneven shape and the present invention. As compared with the electronic component, the electronic component according to the present invention has a ceramic coating layer formed between the surface electrodes. Therefore, when the surface electrode and the ceramic coating layer are formed on the substrate surface, the surface electrode and the ceramic coating are formed. Since the thickness of each layer is approximate, it has a surface state with small irregularities, and therefore the external terminals formed on the surface of the surface electrode The photoresist film can be disposed with a high adhesion between the photoresist film and the ceramic coating layer used when forming the composite metal plating layer, so that the metal plating layer can be accurately placed on the surface electrode. The manufacturing method of the electronic component formed can be provided.

Furthermore , when the electronic component is built in, the length of protrusion of the surface electrode is reduced compared to an electronic component not provided with the ceramic coating layer, and as a result, the unevenness on the outermost surface of the electronic component is reduced. A wiring board with small surface irregularities can be provided.

FIG. 1 is a cross-sectional view showing an embodiment of an electronic component obtained by the method of manufacturing an electronic component according to the present invention (hereinafter sometimes referred to as “electronic component according to the present invention”) . FIG. 2 is a sectional view showing another embodiment of the electronic component according to the present invention. FIG. 3 is a cross-sectional view of the electronic component shown in FIG. 2 along the X-X ′ plane. 4 is a cross-sectional view of the electronic component shown in FIG. 2 along the Y-Y ′ plane. FIG. 5 is an explanatory view showing a method of manufacturing an example of an electronic component according to the present invention. FIG. 6 is a schematic cross-sectional view showing an example of a wiring board (hereinafter, sometimes referred to as “wiring board according to the present invention”) incorporating an electronic component obtained by the electronic component manufacturing method according to the present invention. .

The electronic component according to the present invention is
(1) An electronic component comprising a substrate formed mainly of a crystalline inorganic compound and a surface electrode formed on the surface of the substrate, and
(2) A ceramic coating layer that covers the surface of the substrate that is not covered by the surface electrode and the edge surface portion of the surface electrode, and a surface that is not covered by the ceramic coating layer in the surface electrode is directly coated. A metal plating layer, and
(3) The metal plating layer straddles at least the boundary between the ceramic coating layer and the surface electrode.
Here, “stretching” means that when the surface of the substrate on which the surface electrode and the ceramic coating layer are formed is a flat surface, the ceramic coating layer covers the surface of the surface electrode up to the edge surface portion of the surface electrode. When the state is observed from the plane side of the substrate, the state in which the metal plating layer covers the surface of the surface electrode exposed without being coated with the ceramic coating layer of the surface electrode and the edge surface portion of the ceramic coating layer is designated.

  Here, an embodiment of the electronic component according to the present invention will be described with reference to the drawings.

  FIG. 1 shows an electronic component 1 which is an embodiment of the present invention. The electronic component 1 includes a substrate 2, a surface electrode 3, a ceramic coating layer 4, a metal plating layer 5, and a via conductor 6.

  The substrate 2 contains a crystalline inorganic compound as a main component. Examples of crystalline inorganic compounds include ceramics having a high dielectric constant, such as barium titanate, lead titanate, lead magnesium niobate, lead zinc niobate, barium zirconate, calcium titanate, calcium zirconate, Examples thereof include strontium titanate and potassium sodium lithium niobate. These compounds may be used alone or in combination. As a material for forming the base body 2, it is preferable to use a ceramic mainly composed of barium titanate. More specifically, the content of a crystalline inorganic compound contained in the substrate 2 as a main component, for example, a raw material before sintering, such as barium titanate is usually at least 90% by mass. The substrate may contain other ceramics as long as a constant sinterability and a high dielectric constant can be maintained.

  In addition to the crystalline inorganic compound, acetone, methyl ethyl ketone, diacetone, methyl isobutyl ketone, benzene, bromine are used as materials used to form the substrate 2 so that the substrate 2 has a preferable high dielectric constant after firing. Solvents such as chloromethane, ethanol, butanol, propanol, toluene and xylene; acrylic resins such as polyacrylates and polymethyl methacrylate; binders such as cellulose acetate butyrate, polyethylene, polyvinyl alcohol, and polyvinyl butyral; Plasticizers such as butyl benzyl phthalate, dibutyl phthalate, dimethyl phthalate, phthalate ester, polyethylene glycol derivatives, and tricresol phosphate, fatty acids such as glycerol trioleate Deflocculant, surfactants such as benzenesulfonic acid, and can include alkylaryl polyether alcohols, polyethylene glycol ethyl ether, ethyl phenyl glycol, and wetting agents such as polyoxyethylene esters.

  The shape of the substrate 2 may be any shape as long as a surface electrode 3 and a ceramic coating layer 4 described later can be formed on the surface of the substrate 2, and examples thereof include a plate shape, a rod shape, a lump shape, and a cylindrical shape. it can. A base 2 shown in FIG. 1 is a member having a smooth plate shape.

  Further, the size of the substrate 2 is not particularly limited, and may be determined according to the size of the wiring board in which the electronic component is incorporated when the electronic component according to the present invention is a multilayer ceramic capacitor, for example. . When the electronic component 1 is used as a multilayer ceramic capacitor, the base 2 is often formed to have a thickness of about 300 to 3000 μm.

  The surface electrode 3 is a conductor formed on the surface of the substrate 2. The surface electrode 3 is a member that is electrically connected to an appropriate conductor through a metal plating layer 5 described later when the electronic component 1 is used. The via conductor 6 extends from the surface electrode 3 toward the inside of the base 2 and is electrically connected to a conductor other than the appropriate surface electrode 3 provided inside or outside the base 2. It is a conductor.

  The surface electrode 3 and the via conductor 6 may be formed of the same material or different materials. The metal component contained in the surface electrode 3 and the via conductor 6 is preferably a metal component capable of realizing the electrical characteristics required for the electrode of the electronic component 1, for example, nickel, silver, copper, gold, platinum, and lead. In addition, alloys of these metal components can be used. As a preferable metal component contained in the surface electrode 3 and the via conductor 6, a metal component mainly composed of nickel can be exemplified. In addition, as a metal component contained in the surface electrode 3, it is preferable that it is 99.8 mass%-100 mass% with respect to the surface electrode total mass.

  The surface electrode 3 is formed by, for example, applying a paste obtained by mixing the above metal component powder and an organic solvent such as butyl diglycol to the surface of the substrate 2 by screen printing or the like and then baking the paste. Can be formed. In addition, the via conductor 6 is formed by adding, for example, a crystalline inorganic compound of the base 2, powder of an inorganic compound such as aluminum oxide, silicon dioxide, and titanium oxide and / or an organic binder such as ethyl cellulose to the paste. It can be formed by pouring into a through-hole provided at an appropriate location in the material 2 and further firing. The size of the surface electrode 3 may be determined according to the surface area of the substrate 2, and the size of the via conductor 6 may be determined according to the thickness of the substrate 2. It is preferable that the thickness of the surface electrode 3 is 2 to 20 μm because it is not necessary to increase the thickness of the ceramic coating layer 4 described later, and the material of the ceramic coating layer 4 can be reduced.

Further, as the cross-sectional shape of the surface electrode 3, as shown in FIG. 1, a semicircular shape, a square shape, a horizontally long rectangular shape, rise vertically or obliquely from the base, and the rising tip is rounded and curved, Examples include a shape having a cross-sectional contour that is formed into a gentle convex shape horizontally or upward after being curved, then rounded downward and curved downward, and then vertically or diagonally to the substrate. .
The shape of the via conductor 6 may be a bar shape when the via conductor 6 penetrates the base 2 as in the electronic component 1 shown in FIG.

  Subsequently, the ceramic coating layer 4 covers the surface of the base 2 not covered with the surface electrode 3 and also covers the edge surface portion of the surface electrode 3. The surface electrode 3 is covered with a ceramic coating layer 4 at the edge surface portion, but the surface other than the edge surface portion is directly covered with a metal plating layer. However, the metal plating layer 5 covers the surface of the surface electrode 3 that is not covered with the ceramic coating layer 4, and at least the boundary surface of the ceramic coating layer 4 across the boundary between the ceramic coating layer 4 and the surface electrode 3. The part is also covered.

  In FIG. 1, which is a cross-sectional view taken in the thickness direction of the substrate 2, the surface electrode 3, the ceramic coating layer 4, and the metal plating layer 5 in the electronic component 1, the surface of the substrate 2 is a portion covered with the surface electrode 3. And the portion covered with the ceramic coating layer 4. Furthermore, the surface of the surface electrode 3 is divided into a portion covered with the ceramic coating layer 4 and a portion covered directly with the metal plating layer 5. In FIG. 1, a point where a contour line indicating the surface of the substrate 2 and a contour line indicating the surface of the surface electrode 3 intersect is shown as a substrate-electrode junction 7. Further, the point where the contour line indicating the surface of the surface electrode 3 and the contour line indicating the surface of the ceramic coating layer 4 on the side not in contact with the substrate 2 intersect is shown as an electrode-coating layer junction 8. In other words, the boundary between the surface electrode 3, the ceramic coating layer 4, and the metal plating layer 5 is the electrode-coating layer junction 8. Furthermore, the point where the contour line indicating the surface of the ceramic coating layer 4 on the side not in contact with the substrate 2 and the contour line indicating the surface of the metal plating layer 5 intersect is shown as a coating layer-plating layer junction 9. .

  In other words, the description of the arrangement of the surface electrode 3 and the ceramic coating layer 4 described above is that the surface electrode 3 is from the base-electrode junction 7 to the electrode-coating layer junction 8 on the edge surface portion, that is, the surface of the surface electrode 3. Are covered with the ceramic coating layer 4. Therefore, in the contour line indicating the surface of the surface electrode 3, the portion from one electrode-coating layer junction 8 to the other electrode-coating layer junction 8 is not covered with the ceramic coating layer 4.

  In other words, the description of the arrangement of the surface electrode 3, the ceramic coating layer 4, and the metal plating layer 5 is as follows. In the contour line indicating the surface of the surface electrode 3, from one electrode—coating layer junction 8 to the other electrode— In the contour line indicating the portion up to the coating layer junction point 8 and the surface of the ceramic coating layer 4 on the side not in contact with the substrate 2, the portion from the electrode-coating layer junction point 8 to the coating layer-plating layer junction point 9 is The metal plating layer 5 is covered.

  As a preferred embodiment of the electronic component according to the present invention, as shown in FIG. 1, when the cut surface of the electronic component is observed in the horizontal direction, the substrate-electrode junction 7, the electrode-coating layer junction 8, and the coating layer-plating An embodiment in which the layer junction 9 is in a specific positional relationship can be given.

  Specifically, in the electronic component 1, the coating length “a” of the ceramic coating layer 4 in the direction parallel to the surface of the substrate 2 at the edge surface portion of the surface electrode 3 coated with the ceramic coating layer 4 is It is preferable that the surface of the edge of the ceramic coating layer 4 to be coated is larger than the coating length b of the metal plating layer 5 in the direction parallel to the surface of the substrate 2. In other words, the electronic component 1 has the horizontal distance a (hereinafter referred to as the horizontal distance a) between the substrate-electrode junction 7 and the electrode-coating layer junction 8 in FIG. It is preferable that the aspect is larger than b (hereinafter referred to as horizontal distance b) which is a horizontal distance between the point 8 and the coating layer-plating layer junction 9. When the horizontal distance a is greater than the horizontal distance b, the area where the metal plating layer 5 and the ceramic coating layer 4 overlap is relatively smaller than when the horizontal distance a is smaller than the horizontal distance b. If the area where the metal plating layer 5 and the ceramic coating layer 4 overlap is small, even if residual internal stress due to the difference in thermal expansion coefficient between the ceramic coating layer 4 and the metal plating layer 5 is applied, the metal plating which is a different material is used. Since the residual internal stress applied to the interface between the layer 5 and the ceramic coating layer 4 is reduced, the adhesion between the metal plating layer 5 and the ceramic coating layer 4 can be maintained, and cracks can be prevented. There is an advantage. Conversely, if the horizontal distance a is smaller than the horizontal distance b, cracks may occur near the coating layer-plating layer junction 9 of the ceramic coating layer 4 due to residual internal stress.

The preferred dimension of a which is the horizontal distance between the substrate-electrode junction 7 and the electrode-coating layer junction 8 is 20 μm or more and 125 μm or less, and the electrode-coating layer junction 8 and the coating layer-plating layer junction The preferred dimension of b, which is the horizontal distance from 9, is preferably 5 μm to 124 μm.
When the horizontal distance a is 20 μm or more and 125 μm or less, the surface electrode 3 has a large area sandwiched between the base 2 and the ceramic coating layer 4, so that the plating solution enters the interface between the base 2 and the surface electrode 3. It becomes possible to prevent the surface electrode 3 more reliably and to prevent the surface electrode 3 from being peeled off from the substrate 2. On the other hand, when the horizontal distance a is less than 20 μm, the ceramic coating layer covers the surface electrode. Therefore, the plating solution enters the interface between the ceramic coating layer and the surface electrode, and the plating solution easily enters the interface between the surface electrode and the substrate. There is a high possibility that the surface electrode will fall off the substrate due to poor pressing, and if the horizontal distance a exceeds 125 μm, the ceramic coating of the surface electrode 3 The surface area of 4 surface which is not covered by the (exposed surface) is small, it can cause failure of the energized state.
Further, when the horizontal distance b is 5 μm or more and 124 μm or less, cracks and chipping occur in the ceramic coating layer 4, particularly in the portion covering the edge surface portion of the surface electrode 3 in the ceramic coating layer 4. It becomes possible to prevent. Since the length in the horizontal direction of the cross section, such as cracking and chipping, is usually 120 μm or less, there is little need to increase the horizontal distance b beyond 120 μm. When the horizontal distance b is less than 5 μm, if the growth such as cracking and chipping is fast, there is a possibility that a situation in which the plating solution enters between the surface electrode 3 and the substrate 2 within a short period of time may occur in the future.

  As the material of the ceramic coating layer 4, since the plating solution is often alkaline when forming the metal plating layer 5, a ceramic that is not attacked by the alkaline plating solution is preferable. For example, barium titanate, lead titanate, magnesium niobium Lead acid, zinc zinc niobate, barium zirconate, calcium titanate, calcium zirconate, strontium titanate, and potassium, sodium, lithium niobate, etc., these compounds may be used alone, You may mix and use.

  As a preferable embodiment of the ceramic coating layer 4, an embodiment mainly composed of the same material as the crystalline inorganic compound contained in the substrate 2 can be mentioned. Since the base 2 and the ceramic coating layer 4 are mainly composed of the same material, when the base 2 and the ceramic coating layer 4 are sintered, the base 2 and the ceramic coating layer 4 are easily adapted to each other. The bonding strength with 2 is increased. The increase in the bonding strength makes it difficult for the ceramic coating layer 4 to peel from the base 2. If the ceramic coating layer 4 is difficult to peel from the substrate 2, a part of the ceramic coating layer 4 is formed so as to sandwich the surface electrode 3 together with the surface of the substrate 2. In other words, the surface coating 3 is formed by the ceramic coating layer 4. Is pressed against the substrate 2, the surface electrode 3 is difficult to peel from the substrate 2. When the ceramic coating layer 4 contains 90% by mass or more of the same material as the crystalline inorganic compound of the substrate 2 with respect to the total mass of the ceramic coating layer 4, the bonding strength between the substrate 2 and the ceramic coating layer 4 is increased. The above effect can be easily obtained.

  The size of the ceramic coating layer 4 may be determined according to the size of the surface of the substrate 2 and not covered by the surface electrode 3, and the thickness of the ceramic coating layer 4 is as described above. In addition, the horizontal distance b between the electrode-coating layer bonding point 8 and the coating layer-plating layer bonding point 9 is larger than the horizontal distance a between the substrate-electrode bonding point 7 and the electrode-coating layer bonding point 8. What is necessary is just to determine so that it may become small. Specifically, for example, when the shape of the surface electrode 3 is a flat dome shape as shown in FIG. 1 and the thickness of the most raised portion of the surface electrode 3 is 2 to 20 μm, the surface electrode 3 When the cross-sectional shape is square or rectangular, when the thickness of the surface electrode is 2 to 20 μm, the thickness of the ceramic coating layer 4 may be 1.5 to 15 μm.

  The shape of the ceramic coating layer 4 is not particularly limited because it is determined according to the shape of the surface of the substrate 2 that is not covered by the surface electrode 3 and the shape of the edge surface portion of the surface electrode 3. .

  As a method for forming the ceramic coating layer 4, the material of the surface electrode 3 is applied to the surface of the substrate 2 by screen printing as described above to form the unfired surface electrode 3, and then the unfired substrate 2. And a method of firing after applying the above material of the ceramic coating layer 4 to the edge surface portion of the unfired surface electrode 3 by screen printing or the like. As long as the electronic component 1 has desired electrical characteristics and the object of the present invention can be achieved, the substrate 2, the surface electrode 3, and the ceramic coating layer 4 may be fired separately, and at the same time You can go.

  As a material for the metal plating layer 5, it is necessary for preventing the oxidation of the surface electrode 3 and satisfying the electrical and mechanical properties required for the electronic component 1 and for producing a wiring board incorporating the electronic component 1. As long as the wettability of the solder can be ensured, examples thereof include copper, gold, silver, aluminum, nickel, zinc, tin, iron, rhodium, palladium and platinum, and alloys thereof. A preferred material for the metal plating layer 5 is copper.

  As a method for forming the metal plating layer 5, a conventionally known plating method can be employed. For example, the metal coating layer 5 is covered with the ceramic coating layer 4 of the surface electrode 3 while straddling the boundary between the surface electrode 3 and the ceramic coating layer 4. Examples of the method include plating using electrolytic copper plating with an alkaline copper pyrophosphate bath so that the metal plating layer 5 is formed in a portion that is not. The metal plating layer 5 may have a single layer structure as shown in FIG. 1 or a multi-layer structure.

  In the electronic component 1, the edge surface portion of the surface electrode 3 is covered with the ceramic coating layer 4, so that the plating solution for forming the metal plating layer 5 does not easily enter the interface between the substrate 2 and the surface electrode 3. . If the plating solution does not easily enter the interface between the substrate 2 and the surface electrode 3, it is possible to prevent a situation in which a member to be insulated in the substrate 2 enters a conductive state due to the infiltration of the members to be insulated.

  Further, as shown in FIG. 1, the electronic component 1 is coated with the metal-plated layer 5 at the electrode-coating layer junction 8 and the ceramic coating layer 4 at the substrate-electrode junction 7 so that It is difficult for moisture to enter between the plating layer 5 and the ceramic coating layer 4, between the ceramic coating layer 4 and the surface electrode 3, and between the surface electrode 3 and the substrate 2. Preventing moisture from entering between each member and preventing a situation in which the members to be insulated in the base body 2 are in a conductive state due to the penetration of moisture, and a situation in which each member deteriorates early due to moisture. Can do.

  As the thickness of the metal plating layer 5 to be formed, for example, if it is 10 to 20 μm, the metal plating layer 5 is not easily peeled off or damaged, and moisture can be prevented from entering between the members. preferable.

In the electronic component 1, the substrate 2 and the ceramic coating layer 4 may contain glass. The glass contained in the substrate 2 and the ceramic coating layer 4 may be either crystalline or non-crystalline, for example, silicon dioxide. In addition, when the glass contained in the base body 2 and the ceramic coating layer 4 is 1% by mass or less with respect to the total mass of the base body 2 and the ceramic coating layer 4, it is often used when forming the metal plating layer 5. It is preferable because it is not affected by the plating solution.
A suitable substrate can be formed of a mixture of barium titanate, magnesium oxide, silicon dioxide, manganese dioxide, yttrium oxide, and the composition for forming a suitable substrate includes 95 to 99 masses of barium titanate. Parts, magnesium oxide 0.1-0.8 parts by mass, silicon dioxide 0.1-1.0 parts by mass, manganese dioxide 0.01-0.4 parts by mass, yttrium oxide 0.3-2.7 parts by mass, And a composition comprising 0 to 0.1 parts by mass of calcium oxide.

  When the electronic component according to the present invention is a multilayer ceramic capacitor, a preferable embodiment of the multilayer ceramic capacitor is a multilayer body in which a base is laminated with a conductor layer and a dielectric layer mainly composed of barium titanate. Further, there can be mentioned a laminated structure in which the surface electrode is mainly nickel and the metal plating layer is a copper plating layer. With this preferred embodiment, the electronic component according to the present invention has electrical and mechanical characteristics that can be used as a multilayer ceramic capacitor.

  A further preferred embodiment of the electronic component according to the present invention is shown in FIG. The electronic component 101 shown in FIG. 2 includes a ground via conductor 601 that connects the ground conductor layer 10A and the surface electrode 31 in a direction perpendicular to the surface of the base 21, and the power conductor layer 10B and the surface. A power supply via conductor 602 connecting the electrode 31 is formed. The via array type multilayer ceramic capacitor is configured such that the ground via conductor 601 and the power supply via conductor 602 are aligned at equal intervals when the substrate 21 is cut in a plane parallel to the surface of the substrate 21.

  The base 21 is a laminate formed by laminating the ground conductor layer 10A, the power source conductor layer 10B, and the dielectric layer 11 as in the above-described preferred embodiment. The ground conductor layers 10A and the power source conductor layers 10B are alternately stacked.

  The ground conductor layer 10 </ b> A has conductivity and is electrically connected to the ground via conductor 601. Furthermore, the power supply conductor layer 10 </ b> B has conductivity and is electrically connected to the power supply via conductor 602. The ground conductor layer 10A and the power source conductor layer 10B are formed on the surface of the plate-like dielectric layer 11 by screen printing or the like, for example. The shape and size of the ground conductor layer 10A and the power source conductor layer 10B are not particularly limited, and are appropriately determined depending on the electrical connection between members required for the electronic component 101, the size of the base 21, and the like. It only has to be decided. The material for the ground conductor layer 10A and the power source conductor layer 10B may be determined according to the electrical characteristics required for the electronic component 101 and the adhesion and affinity to the dielectric layer 11, for example. It is preferable to use nickel as a main component. As a material of the ground conductor layer 10A and the power source conductor layer 10B, a dielectric containing nickel as a main component, for example, barium titanate, or magnesium oxide, silicon dioxide, manganese dioxide, yttrium oxide or the like mainly containing barium titanate. It is further preferable to contain.

  The dielectric layer 11 is a part that forms most of the base 21 and is a member in which sheet-like materials are laminated. The dielectric layer 11 has a plate shape, and is laminated so as to sandwich the ground conductor layer 10A and the power supply conductor layer 10B. The ground via conductor 601 and the power supply via conductor 602 are stacked. It is a member that penetrates in the thickness direction. The size and shape of the dielectric layer 11 are not particularly limited. For example, when the electronic component 101 is a capacitor and is incorporated in the wiring substrate, it may be determined so as to match the size and shape of the wiring substrate. . The material of the dielectric layer 11 is preferably mainly composed of barium titanate. Further, it is more preferable that the dielectric layer 11 includes a dielectric material such as magnesium oxide, silicon dioxide, manganese dioxide and yttrium oxide mainly composed of barium titanate.

  As shown in FIG. 2, the ground via conductor 601 and the power supply via conductor 602 penetrate from one surface of the base body 21 to the surface on the opposite side of the ground conductor layer 10 </ b> A and the power supply conductor layer 10 </ b> B in the base body 21. By doing so, the surface electrode 31 formed on one surface of the base 21 and the opposite surface is electrically connected. In the electronic component according to the present invention, when a surface electrode is formed on one surface of the substrate and the surface on the opposite side, a single bar-shaped via conductor penetrates from one surface of the substrate to the surface on the opposite side. As long as at least the conductor layer and the surface electrode are electrically connected to each other, the via conductor may be formed to be inclined with respect to the surface of the substrate, and the rod-like shape may be short in the thickness direction of the substrate. Via conductors may be arranged with their axes shifted. The material, shape, size, and the like of the ground via conductor 601 and the power supply via conductor 602 are the same as those of the via conductor 6 shown in FIG. As a preferred embodiment of the ground via conductor 601 and the power supply via conductor 602, for example, a plurality of ground via conductors 601 and power supply via conductors 602 penetrate from one surface of the base 21 to the opposite surface, and further each ground. When the base 21 is cut along a plane parallel to the surface of the base 21, the via via conductor 601 and the power supply via conductor 602 are installed so that the axes thereof are parallel to each other. An example is an embodiment in which the conductors 602 are arranged at equal intervals, and the ground via conductors 601 and the power supply via conductors 602 are alternately arranged. In the electronic component of this aspect, inductance can be reduced by making the polarities of adjacent via conductors alternate.

  The positional relationship among the surface electrode 31, the ceramic coating layer 41, and the metal plating layer 51 of the electronic component 101 shown in FIG. 2, that is, the ceramic coating layer 41 is formed on the edge surface portion of the surface electrode 31, and the surface electrode 31 and the ceramic coating layer are formed. As for the aspect in which the metal plating layer 51 is formed on the surface of the surface electrode 31 so as to straddle the boundary with 41, the surface electrode 3, the ceramic coating layer 4 and the metal plating layer 5 of the electronic component 1 shown in FIG. This is the same as the positional relationship.

  Here, FIG. 3 shows a cross-sectional view of the electronic component 101 shown in FIG. 2 cut along the X-X ′ plane, and FIG. 4 shows a cross-sectional view of the electronic component 101 cut along the Y-Y ′ plane.

  When the electronic component 101 is cut along the XX ′ plane, as shown in FIG. 3, the ground conductor layer 10A is exposed, and the ground via conductor 601 and the power via conductor 602 are arranged in 7 rows and 7 columns, etc. The ground via conductors 601 are electrically connected by the ground conductor layer 10A, and the ground conductor layer 10A and each power supply via conductor 602 are electrically connected. Therefore, it can be seen that the ground via conductors 601 and the power supply via conductors 602 are not electrically connected.

  When the electronic component 101 is cut along the YY ′ plane, as shown in FIG. 4, the power supply conductor layer 10B is exposed, and the ground via conductor 601 and the power supply via conductor 602 are arranged in 7 rows and 7 columns, etc. The power supply via conductors 602 are electrically connected by the power supply conductor layer 10B, and the power supply conductor layer 10B and the ground via conductors 601 are electrically connected. Therefore, it can be seen that the ground via conductors 601 and the power supply via conductors 602 are not electrically connected.

  Here, a method for manufacturing an electronic component according to the present invention will be described.

  The method of manufacturing an electronic component according to the present invention includes a step of forming an unfired surface electrode as a surface electrode on the surface of an unfired substrate as a substrate, and a surface not covered with the unfired surface electrode on the surface of the unfired substrate And a ceramic coating step of coating the peripheral surface portion of the unfired surface electrode with a ceramic paste to be a ceramic coating layer, a firing step of firing an unfired substrate coated with the ceramic paste, and a surface electrode obtained by the firing step, The metal plating process which coat | covers the surface which is not coat | covered with the ceramic coating layer with a metal plating layer across the boundary of a ceramic coating layer and a surface electrode at least can be mentioned. Hereinafter, as a specific example, a method for manufacturing the electronic component 101 according to one embodiment of the present invention will be described.

  The base 21 of the electronic component 101 includes the ground conductor layer 10A, the power source conductor layer 10B, and the dielectric layer 11, and the steps for forming each of them are different.

  In order to form an unfired substrate to be the substrate 21, an unfired dielectric layer to be the dielectric layer 11 is first prepared. The unfired dielectric layer is composed of, for example, a barium titanate powder as a main component, a dielectric powder such as magnesium oxide, silicon dioxide, manganese dioxide and yttrium oxide, an appropriate dispersant, an appropriate plasticizer, ethanol, and toluene. It can be formed by forming a slurry obtained by wet mixing in a mixed solvent, etc., adding a binder and further mixing into a sheet-like material sometimes called a green sheet by the doctor blade method or the like. it can.

  Further, when the ground conductor layer 10A and the power source conductor layer 10B are provided in the base body 21 as in the electronic component 101, the ground conductor layer 10A and the power source conductor layer 10B are formed on the surface of the unfired dielectric layer. An unsintered conductor layer is formed. The unfired conductor layer is, for example, nickel powder, dielectric powder containing barium titanate as the main material, magnesium oxide, silicon dioxide, manganese dioxide, yttrium oxide, terpineol and butyldiglycol solvent, and cellulose resin. It can be formed by applying a paste obtained by wet-mixing an organic vehicle containing an appropriate volume ratio to an object such as an unfired dielectric layer by screen printing. At this time, the diameter of the clearance hole of the unfired conductor layer may be about 100 to 800 μm. But when the electronic component which concerns on this invention is an aspect by which a conductor layer is not provided in a base | substrate, the process of forming an unbaking conductor layer is unnecessary.

In the step of preparing the unfired substrate, a plurality of unfired dielectric layers formed by forming an unfired conductor layer on the surface are formed on a desired substrate 21 under conditions of, for example, 60 to 80 ° C. and 200 to 500 kgf / cm ^2. This is achieved by laminating and pressure bonding to a thickness of.

  When the ground via conductor 601 and the power supply via conductor 602 are formed as in the electronic component 101, before the step of forming the unfired surface electrode to be the surface electrode 31 on the surface of the unfired substrate. An unfired via conductor may be formed in the unfired substrate. The unfired via conductor is composed of nickel powder, dielectric powder such as magnesium oxide, silicon dioxide, manganese dioxide, yttrium oxide based on barium titanate, terpineol and butyldiglycol solvent, and cellulose resin. It can be formed using a paste obtained by wet-mixing the organic vehicle containing with an appropriate volume ratio. As a method for forming an unfired via conductor, for example, a method is used in which a through hole having a diameter of about 100 to 300 μm is formed in an unfired substrate by a laser molding machine or the like, and a paste obtained by screen printing or the like is filled in the through hole. Can be mentioned.

  In the electronic component 101, the ground via conductor 601 and the power supply via conductor 602 are formed in a single bar shape perpendicular to the surface of the base 21, but short bar-shaped via conductors are arranged with their axes shifted. In this case, an unsintered via conductor is formed by laminating and pressing the unsintered dielectric layers after providing through holes in the unsintered dielectric layer formed by printing the unsintered conductor layer and filling the paste. A formed green substrate can be produced.

  Next, as a step of forming an unfired surface electrode to be the surface electrode 31 on the surface of the unfired substrate, first, nickel powder, barium titanate, and barium titanate are used as the main materials, magnesium oxide, silicon dioxide, manganese dioxide, and oxidation. A dielectric powder containing yttrium, etc., and a terpineol and butyl diglycol solvent, and an organic vehicle containing a cellulose resin, etc. are wet mixed at an appropriate volume ratio to prepare a paste, which is used as a surface electrode forming paste. When the surface electrode forming paste is applied on the surface of the unfired substrate by screen printing or the like so that the desired surface electrode 31 is disposed, the surface of the unfired substrate 21A is unfired as shown in FIG. A surface electrode 31A is formed. The unsintered surface electrode 31A is also formed on the back surface of the unsintered substrate 21A. In FIG. 5, reference numeral 61A denotes an unfired via conductor. After printing the surface electrode forming paste, dry the unfired surface electrode and solidify the unfired surface electrode to some extent, without breaking the shape of the formed unfired surface electrode. The layer 41 is preferable because it is easy to form.

  Further, the ceramic coating process for coating the surface of the unfired substrate that is not covered with the unfired surface electrode and the edge surface portion of the unfired surface electrode with a ceramic paste that forms the ceramic coating layer 41 is shown in FIG. Thus, the mask member 27 is disposed on the surface of the unfired substrate 21A on which the unfired surface electrode 31A is formed, and ceramic powders such as barium titanate, magnesium oxide, silicon dioxide, manganese dioxide, and yttrium oxide, A ceramic coating layer forming paste 28 obtained by kneading a dispersant and a binder with terpineol and a butyl diglycol solvent is used to paste the peripheral surface portion of the green surface electrode 31A and the green surface through the mask member 27. Coating is performed by so-called screen printing or the like that covers the surface of the base 21A. And, the green ceramic coating layer 41A is formed. Here, the unfired ceramic coating layer 41A contains silicon dioxide, but the content of silicon dioxide is 1% by mass or less with respect to the total mass of the unfired ceramic coating layer 41. The ceramic coating layer 41 formed by firing the coating layer is not attacked by the alkaline plating solution.

  The unfired surface electrode and the unfired ceramic coating layer take into account the deformation or shrinkage of the material due to firing, and the horizontal distance between the substrate-electrode junction 7 and the electrode-coating layer junction 8 as shown in FIG. It may be formed so that a has a desired size.

  Subsequently, the firing step of firing the unfired substrate coated with the ceramic paste is a step of firing the unfired substrate, the unfired via conductor, the unfired surface electrode, and the unfired ceramic coating layer. An example is a condition in which an unfired substrate is defatted at 200 to 300 ° C. for 5 to 20 hours in the air and then fired at 1100 to 1400 ° C. in a reducing atmosphere. As shown in FIG. 5, a fired body including the surface electrode 31 and the ceramic coating layer 41 is formed on the surface of the base 21 by firing.

  Next, the metal plating step of covering the surface of the surface electrode 31 obtained by the firing step that is not covered with the ceramic coating layer 41 with at least the boundary between the ceramic coating layer 41 and the surface electrode 31 with the metal plating layer 51, For example, it is achieved by applying electrolytic plating with an alkaline copper pyrophosphate bath to the surface of the surface electrode 31 so as to straddle the boundary between the ceramic coating layer 41 and the surface electrode 31. That is, regarding the electronic component 1 in which the positional relationship among the surface electrode, the ceramic coating layer, and the metal plating layer in the electronic component 101 is the same, the metal plating layer 5 (51) is as shown in FIGS. The front electrode 3 (31) is directly covered, and a part of the ceramic covering layer 4 (41) is also covered across the electrode-covering layer junction 8.

  Through the above steps, for example, an electronic component 101 as shown in FIG. 2 can be manufactured. In the manufactured electronic component 101, the ceramic coating layer 41 covers the edge surface portion of the surface electrode 31, so that when the metal plating layer is formed, the plating solution enters from the interface between the surface electrode 31 and the substrate 21. Since the portion where the surface electrode 31 is exposed is reduced by forming the ceramic coating layer 41, the impact that the surface electrode 31 receives from the external environment is reduced, and as a result, the surface electrode 31 becomes difficult to peel, Normally, there is a possibility that moisture in the use environment may enter between the dielectric layer of the substrate and the via conductor, and between the conductor layer and the dielectric layer. Since it coat | covers with the layer 41 and a part of ceramic coating layer 41 and the surface electrode 31 are coat | covered with the metal plating layer 51, it has high moisture resistance. In addition, when the electronic component has moisture resistance, it is possible to prevent a situation in which a member to be insulated is in a conductive state due to moisture that has entered, and a situation in which each member is deteriorated early due to moisture. it can.

  The electronic component according to the present invention can be applied to a multilayer ceramic capacitor, an inductor, and an ultrasonic vibrator, and is particularly suitable for a multilayer ceramic capacitor.

  Furthermore, the wiring board according to the present invention includes the electronic component according to the present invention. Normally, when a wiring board that contains electronic components such as capacitors is formed, the outer shape of the wiring board is formed according to the unevenness of the surface of the electronic component, and when metal plating for external terminals is applied on the surface electrode of the laminated electronic component The photoresist film used as the masking needs to be closely attached to the unevenness of the surface of the electronic component. Therefore, when the unevenness on the surface of the electronic component is large, the adhesion of the photoresist film on the surface of the electronic component is reduced, the variation in the thickness of the metal plating for the external terminal, the unevenness in the outer shape of the wiring board, etc. Can happen. Note that if the wiring board has irregularities in its outer shape, contact failure may occur when the wiring board is electrically connected to another electronic device.

  In the electronic component according to the present invention, the length of the surface electrode protruding from the base is smaller than that of the conventional electronic component. More specifically, compared with the thickness of the surface electrode when the ceramic coating layer is not provided, that is, the thickness of the surface electrode at the most protruding portion of the surface electrode from the surface of the substrate, the electronic component according to the present invention Since the ceramic coating layer is provided on the surface, the length of the surface electrode protruding from the surface of the ceramic coating layer, which is the thickness of the surface electrode, is small. In other words, the electronic component according to the present invention has less unevenness on the surface than in the past. Therefore, the electronic component according to the present invention can obtain high adhesion when the photoresist film is brought into close contact with the surface having less unevenness in the electronic component.

  Therefore, since the wiring board according to the present invention in which the electronic component according to the present invention is incorporated has small irregularities on the surface of the electronic component according to the present invention, the thickness of the metal plating for the external terminal is less likely to vary. As a result, the outer shape of the wiring board is less likely to be uneven. Further, even if variations in the thickness of the metal plating for the external terminal and irregularities in the outer shape of the wiring board occur, it can be in a very small range. Therefore, the wiring board according to the present invention is less likely to cause an electrical contact failure between the wiring board and another electronic device due to the fact that there is no unevenness in the outer shape, or even if the unevenness occurs.

  Here, an embodiment of the wiring board according to the present invention will be described with reference to the drawings.

  FIG. 6 is a schematic sectional view showing an example of a wiring board according to the present invention. The wiring board 12 is formed on the base 141 having the core main surface 13a and the core back 13b, the wiring laminated portion 15a formed on the core main surface 13a of the base 141, and the core back 13b of the base 141. And the electronic component 101 accommodated in the substrate 141 or the wiring laminate portions 15a and 15b. In addition, a member formed by laminating a base material 141 and resin insulating layers 23a and 23b described later may be referred to as “resin core substrate 14” below. Note that the electronic component 101 shown in FIG. 6 is made of the same member as the electronic component 101 shown in FIG.

  The resin core substrate 14 is a core substrate that accommodates the electronic component 101 and supports the entire wiring substrate 12. The resin core substrate 14 usually has a housing portion 16 that houses the electronic component 101. The accommodating portion 16 is formed by at least one of a through hole and a bottomed hole provided in the resin core substrate 14. The material of the resin core substrate 14 is not particularly limited, but it is preferable to use a heat-resistant polymer material such as an epoxy resin, a polyimide resin, a bismaleimide / triazine resin, or a polyphenylene ether resin. Furthermore, in order to obtain a resin core substrate 14 having even better strength and thermal characteristics, glass fiber, glass fiber woven fabric, glass fiber nonwoven fabric, polyamide fiber woven fabric, or the like may be provided as a core material.

  The resin core substrate 14 can be provided with a through-hole conductor 17 that conducts the core main surface 13a and the core back surface 13b. The through-hole conductor 17 may be filled in the through-hole, and other portions except for the through-hole conductor 17 formed on the inner wall surface of the through-hole are closed by the insulating cured body 18. May be.

  The electronic component 101 is usually fixed in the housing portion 16 with a filler 19 containing a resin material such as an epoxy resin while being housed in the housing portion 16 having the resin core substrate 14.

  The wiring laminated portions 15 a and 15 b are usually laminated on both surfaces of the resin core substrate 14 and the electronic component 101 accommodated in the resin core substrate 14. The wiring laminated portion 15a is formed by alternately laminating conductive layers 20a and 20b and resin insulating layers 22a, 22b, 23a, and 23b, and includes resist layers 24a and 24b in the outermost layer. The wiring laminated portions 15a and 15b may be formed only on one surface side of the wiring substrate 12, but are usually formed on both surface sides and are preferably formed symmetrically in the stacking direction.

  In general, the inter-terminal pitch of the connection terminals 25a arranged on the semiconductor element 26 side of the wiring board 12 incorporating the laminated electronic component and the like and the inter-terminal pitch of the connection terminals 25b arranged on the motherboard side of the wiring board 12 are: There is a big difference. Therefore, by providing the wiring laminated portions 15a and 15b, the pitch can be freely adjusted in the wiring laminated portions 15a and 15b, and the terminal board pitch of the wiring board 12 is output from the upper surface side to the lower surface side in FIG. Can be.

  Further, the material of the resin insulating layers 22a, 22b, 23a, and 23b in the wiring laminated portions 15a and 15b is not particularly limited, but has heat resistance such as epoxy resin, polyimide resin, bismaleimide / triazine resin, polyphenylene ether resin, and the like. It is preferable to use a polymer material. In addition, the conductive layers 20a and 20b of the wiring laminated portions 15a and 15b may be electrically connected to other conductive layers using vias or the like as necessary.

  Here, a method for manufacturing the wiring board 12 shown in FIG. 6 will be described.

  First, for example, a copper clad laminate (not shown) in which a copper foil is pasted on both surfaces of a base material 141 having a length of 400 mm, a width of 400 mm, and a thickness of 0.65 mm is prepared. After roughening the upper surface and the lower surface of the substrate 141, an epoxy resin film with a thickness of 80 μm to which an inorganic filler has been added is attached to the upper surface and the lower surface of the substrate 141 by thermocompression to form the resin insulating layers 23a and 23b. To do.

  Next, a conductive layer 20a having a thickness of 50 μm is formed on the upper surface of the resin insulating layer 23a and the lower surface of the resin insulating layer 23b. Specifically, after performing electroless copper plating on the upper surface of the resin insulating layer 23a and the lower surface of the resin insulating layer 23b, an etching resist is formed, and then electrolytic copper plating is performed. Further, the etching resist is removed and soft etching is performed. Next, the laminated body composed of the base material 141 and the resin insulating layers 23a and 23b is perforated using a router to form a through hole serving as the accommodating portion 16 at a predetermined position, Get the product.

  Subsequently, with the core main surface 13a and the electronic component main surface 13c facing the same side, and the core back surface 13b and the electronic component back surface 13d facing the same side, the electronic component 101 is appropriately placed in the housing portion 16. It is accommodated using a mounting device. The opening on the core back surface 13b side of the housing portion 16 is sealed with a peelable adhesive tape, and the electronic component 101 is attached to the adhesive surface of the tape and temporarily fixed.

  Further, a filler 19 made of a thermosetting resin is filled in the gap between the inner surface of the housing portion 16 and the side surface of the electronic component 101 using an appropriate dispenser device. Then, when heat processing are performed, the electronic component 101 is fixed in the accommodating part 16 because the filler 19 hardens | cures. The adhesive tape peels at this point.

  Thereafter, the surface of the metal plating layer 51 covering the surface electrode 31 in the electronic component 101 is roughened to obtain a rough surface having a surface roughness Ra of about 0.3 μm.

  Further, based on a conventionally known method, the wiring laminated portion 15a is formed on the core main surface 13a, and the wiring laminated portion 15b is formed on the core back surface 13b. The resist layers 24a and 24b are formed by applying and curing a photosensitive epoxy resin on the surface of the layer including the conductive layers 20a and 20b formed on the surfaces of the resin insulating layers 23a and 23b. Thereafter, exposure and development are performed in a state where a predetermined mask is arranged, thereby patterning openings for forming the connection terminals 25a and 25b in the resist layers 24a and 24b. Further, the connection terminals 25a and 25b are formed in the opening by solder, thereby completing the wiring board 12.

  The electronic component according to the present invention was verified with respect to the difficulty of penetrating the electronic component plating solution, the difficulty of peeling off the surface electrode, and the difficulty of generating cracks in the ceramic coating layer.

Example 1
In Example 1, a laminated electronic component including a laminate formed by laminating a conductor layer and a dielectric layer, a via conductor, a surface electrode, a ceramic coating layer, and a metal plating layer was prepared. . The manufacturing process of the multilayer electronic component is as follows.
(1) Green sheet Average grain containing 98.5 parts by mass of barium titanate, 0.3 parts by mass of magnesium oxide, 0.4 parts by mass of silicon dioxide, 0.2 parts by mass of manganese dioxide, and 0.6 parts by mass of yttrium oxide A dielectric powder mixture having a diameter of 0.5 μm, 1.0 part by mass of a polymer type anionic dispersant as a dispersant, 3.0 parts by mass of dibutyl phthalate as a plasticizer, 15 parts by mass of ethanol and 25 toluene. Wet mixing was performed using a mixed solvent with parts by mass. To the mixture obtained by wet mixing, 9.0 parts by weight of polyvinyl butyral having a molecular weight of about 50000 was added as a butyral binder and further mixed to obtain a slurry. A 7 μm thick sheet and 30 μm thick sheet were produced from the slurry by a doctor blade method. The sheet-like material having a thickness of 7 μm is a green sheet that forms a layer other than the surface of the substrate that is a laminate, that is, a layer that will be positioned inside, and the sheet-like material having a thickness of 30 μm is a surface layer of the substrate. Is a green sheet.
(2) Surface electrode paste Next, 80 parts by mass of nickel powder, 19.7 parts by mass of barium titanate powder, and 0.06 parts by mass of magnesium oxide, all having a particle size of 0.4 to 10.0 μm. A dielectric ceramic composition powder mainly comprising rare earth oxides of 0.08 parts by mass of silicon dioxide, 0.04 parts by mass of manganese dioxide, and 0.12 parts by mass of yttrium oxide, and mainly composed of barium titanate; A paste for a surface electrode was prepared by kneading 80 parts by mass of an inorganic solid formed by mixing an organic vehicle containing 20 parts by mass of terpineol and 80 parts by mass of ethyl cellulose. The surface electrode paste was kneaded with three rolls and adjusted so that the viscosity was about 100 Pa · s when the paste was applied.
(3) Conductor layer paste Subsequently, 12% by volume of nickel powder having an average particle size of 0.2 μm, 3% by volume of the dielectric powder mixture having an average particle size of 0.1 μm, and 85 of the organic vehicle. A conductor layer paste was prepared by wet mixing at a volume percentage. The conductor layer paste was adjusted to have a viscosity of about 11 Pa · s.
(4) Via conductor paste Furthermore, 40% by volume of nickel powder having an average particle diameter of 2.5 μm, 16% by volume of the dielectric powder mixture having an average particle diameter of 0.5 μm, and 44 of the organic vehicle. A via conductor paste was prepared by wet mixing at a volume percentage. The via conductor paste was adjusted to have a viscosity of about 1000 Pa · s.
(5) Ceramic coating layer paste A slurry obtained in the same manner as in step (1) except that the viscosity of the slurry was adjusted to about 100 Pa / s was used as the ceramic coating layer paste.
(6) Unsintered laminated body Next, the conductor layer paste is screened on the surface of the 7 μm thick green sheet prepared in (1) so that the hole diameter of the clearance hole of the conductor layer is about 400 μm in the unsintered state. It was coated by printing. 100 to 150 green sheets formed by applying the conductor layer paste were pressure-bonded and laminated under the conditions of 60 to 80 ° C. and about 300 kgf / cm ² . Further, the green sheet having a thickness of 30 μm prepared in (1) is pressure-bonded to both sides of the laminate of the green sheets coated with the conductor layer paste under the conditions of 60 to 80 ° C. and about 300 kgf / cm ^2. A green laminate having a thickness of about 1200 μm was formed.
(7) Through-holes Through-holes having a hole diameter of about 120 μm were formed at 450 to 700 μm intervals on the unfired laminate by a laser molding machine.
(8) Unsintered via conductor By filling the through-hole formed in the unsintered laminate with via conductor paste by screen printing, an unsintered via conductor was formed inside the unsintered laminate.
(9) Unsintered surface electrode Next, the unsintered laminated body in which the unsintered via conductor is formed is installed in a screen printing apparatus. On the surface of the installed unfired laminate, a mask member in which a through-hole having an appropriate shape is formed is disposed so that a surface electrode is formed at a desired position. Further, the surface electrode paste is supplied to the surface of the mask member while the mask member is arranged, and the squeegee is slid on the mask member so that the surface electrode paste is applied to the mask member by scissors. By this sliding of the squeegee, the surface electrode paste is imprinted in the through hole of the mask member. Therefore, the pattern of the surface electrode is printed on the surface of the unfired laminated body through each through hole of the mask member. After printing, the mask member is removed from the green laminate. The unfired laminate on which the unfired surface electrode is printed is removed from the screen printing apparatus and dried to solidify the unfired surface electrode to some extent.
(10) Coating of ceramic coating layer paste The ceramic coating layer paste was applied to the green laminate produced in (9). The coating of the ceramic coating layer paste is basically performed in accordance with the process shown in (9) above, and instead of a mask member in which a through-hole is provided at the position of the surface electrode, an unfired laminate A mask member was used in which a through hole was provided at a location where the mask member was placed on the surface of the body and contacted with the surface of the laminate and the peripheral surface portion of the unfired surface electrode.
(11) Firing laminate A non-firing laminate formed by forming an unfired via conductor, an unfired surface electrode, and an unfired ceramic coating layer is degreased at 250 to 300 ° C in the atmosphere for 10 to 20 hours. Then, a fired laminate was obtained by firing at 1200 to 1300 ° C. in a reducing atmosphere.
(12) Metal plating layer The surface of the fired laminate was cleaned by wet blasting, for example, by removing the oxide layer on the surface of the fired laminate. Furthermore, the metal plating layer that straddles the boundary between the surface electrode and the ceramic coating layer and covers the surface electrode by electrolytic copper plating using an alkaline copper pyrophosphate bath is adjusted so that the thickness of the plating is 10 to 20 μm. While forming. The plating thickness was measured by fluorescent X-ray.
Through the above steps, a laminated electronic component including a substrate, a surface electrode, a via conductor, a ceramic coating layer, and a metal plating layer was produced.

  As data indicating the overlapping state of the surface electrode and the ceramic coating layer and the overlapping state of the ceramic coating layer and the metal plating layer, the substrate-electrode junction point 7 and the electrode-coating layer junction point 8 as shown in FIG. The horizontal distance a and the horizontal distance b between the electrode-coating layer junction 8 and the coating layer-plating layer junction 9 were measured. The horizontal distance a and the horizontal distance b are measured by first cutting the manufactured electronic component in the thickness direction of the substrate, the surface electrode, and the ceramic coating layer, and mirror-polishing the cut surface to obtain an electronic device as shown in FIG. The cross section of the part can be observed, and a method of measuring the horizontal distance a and the horizontal distance b on the cut surface with a scanning electron microscope based on an image obtained at a magnification of 1000 times was adopted. Table 1 shows the measurement results of the horizontal distance a and the horizontal distance b of the electronic component manufactured in Example 1.

(Examples 2-4 and 6)
In Examples 2 to 4 and 6, the same steps as in Example 1 except that the horizontal distance a, which is the overlap length between the surface electrode and the ceramic coating layer of the multilayer electronic component produced in Example 1, was changed. A laminated electronic component was fabricated along The horizontal distance a and the horizontal distance b of Examples 2 to 4 and 6 are shown in Table 1, respectively.

(Examples 5 and 6)
A laminated electronic component was manufactured in the same manner as in Example 1 except that the horizontal distance a and the horizontal distance b were set to the values shown in Table 1, respectively.

(Comparative Example 1)
A laminated electronic component was produced in the same manner as in Example 1 except that the horizontal distance b was changed to the value shown in Table 1.

(Comparative Example 2)
In Comparative Example 2, a laminated electronic component was produced according to the same steps as in Example 1 except that the ceramic coating layer and the metal plating layer of the laminated electronic component produced in Example 1 were not formed.

(Comparative Example 3)
In Comparative Example 3, a laminated electronic component was produced according to the same steps as in Example 1 except that a glass layer was formed instead of the ceramic coating layer of the laminated electronic component produced in Example 1. The glass layer was completely different from the ceramic coating layer as described below. Glass paste was used as the material for the glass layer. First, powders such as silicon dioxide, barium oxide, aluminum oxide, calcium oxide, zinc oxide, sodium carbonate, potassium carbonate, magnesium oxide, barium oxide, strontium oxide, and zirconium oxide are mixed, heated, melted, and then poured into water. By this, the glass frit crushed and ground is obtained. Next, the glass frit is pulverized by a ball mill until it becomes a powder having an average particle diameter of 3 μm to obtain glass powder. Next, 50% by mass of the obtained glass powder and 50% by mass of the aluminum oxide powder were mixed by a ball mill. A glass paste was prepared by adding 18 parts by mass of ethyl cellulose as a binder, 2 parts by mass of dibutyl phthalate as a plasticizer, and 80 parts by mass of terpineol as a solvent to 100 parts by mass of the mixed powder.
A laminated electronic component was manufactured in the same manner as in Example 4 except that the glass paste was used instead of the ceramic coating layer paste.

  In Table 1, when the material used for forming the ceramic coating layer in Examples 1 to 6 and Comparative Examples 1 to 3 is a crystalline inorganic compound, it is indicated as “dielectric porcelain composition” and is made of glass such as silicon dioxide. In some cases, “glass paste” was indicated, and in the case where the ceramic coating layer was not formed, “−” was indicated.

  The difficulty of penetration of the plating solution in the manufactured electronic component was evaluated by measuring the insulation resistivity before and after the formation of the metal plating layer and calculating the reduction rate of the insulation resistivity. For the measurement of the insulation resistance value, the electrical resistance was measured before and after the formation of the metal plating layer of the above (12) using an ultrahigh resistance meter. In addition, before the measurement of electrical resistance, the process by wet blasting was performed before and after plating. When the plating solution entered between the surface electrode and the substrate, and further between the via conductor, the conductor layer, and the dielectric layer, the insulation resistance value decreased. In addition, as an evaluation standard, an electronic component having a decrease rate of the insulation resistance value of 30% or more cannot be practically used.

  The presence or absence of peeling of the surface electrode in the produced electronic component was evaluated by mirror-polishing the cross section and observing the surface electrode with a magnification of 1000 times using an operation microscope.

  Regarding the difficulty of cracking of the ceramic coating layer in the fabricated electronic component, the thickness of the ceramic coating layer of the electronic component, particularly the ceramic coating layer covering the edge surface portion of the surface electrode, is reduced by a scanning electron microscope. The observed part was observed at a magnification of 1000 times, and judged by the presence or absence of cracks. Each measurement result is shown in Table 2.

  As shown in the results of Examples 1 to 6, the ceramic coating layer is formed so as to cover the edge surface portion of the surface electrode, and the surface electrode is formed so as to straddle the boundary between the surface electrode and the ceramic coating layer. When the metal plating layer to be coated was formed, there was little or no penetration of the plating solution, no peeling of the surface electrode occurred, and no crack was generated in the ceramic coating layer. The absence or small penetration of the plating solution is less likely to cause unintended electrical connection in the electronic components of Examples 1 to 6 than in Comparative Examples 2 and 3 in which the rate of decrease in the insulation resistance value was large. Further, considering that no cracks were generated in the ceramic coating layer, the electronic components of Examples 1 to 6 were not resistant to moisture as compared to Comparative Examples 1 and 2 in addition to Comparative Examples 2 and 3. High nature. As compared with Comparative Example 2 in which the ceramic coating layer was not formed, the electronic components of Examples 1 to 6 were less likely to cause the surface electrode to peel off.

  For the electronic component of Comparative Example 3, when the glass layer formed in place of the ceramic coating layer formed the metal plating layer, the glass layer was attacked by the alkaline plating solution and the infiltration of the plating solution was allowed. In addition to this, it is considered that the stress that presses the surface electrode against the substrate by covering a part of the surface electrode is lowered and the surface electrode is peeled off.

  Therefore, a ceramic coating layer that covers the surface of the substrate that is not covered by the surface electrode and covers the edge surface portion of the surface electrode, and a metal plating layer that covers the surface of the surface electrode that is not covered by the ceramic coating layer In addition, the metal plating layer prevents at least the penetration of plating solution, peeling of the surface electrode, and the generation of cracks in the ceramic coating layer when the metal plating layer straddles the boundary between the ceramic coating layer and the surface electrode. can do.

DESCRIPTION OF SYMBOLS 1,101 Electronic component 2,21 Base | substrate 21A Unbaked base | substrate 3,31 Surface electrode 31A Unbaked surface electrode 4,41 Ceramic coating layer 41A Unbaked ceramic coating layer 5,51 Metal plating layer 6 Via conductor 601 Ground via conductor 602 Via conductor for power supply 61A Unfired via conductor 7 Substrate-electrode junction 8 Electrode-coating layer junction 9 Covering layer-plating layer junction 10A Ground via conductor 10B Power conductor layer 11 Dielectric layer 12 Wiring substrate 13a Core main Surface 13b Core back surface 13c Electronic component main surface 13d Electronic component back surface 14 Resin core substrate 14 Base material 15a, 15b Wiring laminated portion 16 Housing portion 17 Through-hole conductor 18 Insulating cured body 19 Filler 20a, 20b Conductive layers 22a, 22b, 23a, 23b Resin insulating layer 24a, 24b Resist layer 25a, 25b Connection terminal 26 Semiconductor element 27 Mask member 28 Ceramic coating layer forming paste

Claims (5)

An electronic component comprising a substrate containing a crystalline inorganic compound and a surface electrode present on the surface of the substrate,
A ceramic coating layer that covers a surface of the substrate that is not covered with the surface electrode and covers a surface portion of the edge of the surface electrode; and a surface of the surface electrode that is not covered with the ceramic coating layer directly A method of manufacturing an electronic component having a metal plating layer that covers and covers the edge surface portion of the ceramic coating layer that covers the edge surface portion of the surface electrode ,
Forming a green surface electrode to be the surface electrode on the surface of the green substrate to be the base;
A ceramic coating step of coating a surface of the unfired substrate that is not coated with the unfired surface electrode and an edge surface portion of the unfired surface electrode with a ceramic paste serving as the ceramic coating layer;
A firing step of firing the unfired substrate coated with the ceramic paste;
A metal plating step of covering the surface of the surface electrode obtained by the firing step that is not covered with the ceramic coating layer and the edge surface portion of the ceramic coating layer that covers the edge surface portion of the surface electrode with the metal plating layer When,
A method for manufacturing an electronic component, comprising: The coating length a of the ceramic coating layer in the direction parallel to the surface of the substrate in the edge surface portion of the surface electrode covered by the ceramic coating layer is the edge surface portion of the ceramic coating layer covered by the metal plating layer. 2. The method of manufacturing an electronic component according to claim 1, wherein an electronic component having a length greater than a coating length b of the metal plating layer in a direction parallel to the surface of the substrate is manufactured.   The base is a laminate formed by laminating a conductor layer and a dielectric layer mainly composed of barium titanate,
  The surface electrode is mainly nickel,
  3. The method of manufacturing an electronic component according to claim 1, wherein the metal plating layer is a multilayer electronic component that is a copper plating layer.   A via conductor connecting the conductor layer and the surface electrode in a direction intersecting the surface of the substrate;
  4. The via array type multilayer ceramic capacitor in which the via conductors are arranged at equal intervals when the base is cut along a plane parallel to the surface of the base. Manufacturing method of electronic components.   5. The method of manufacturing an electronic component according to claim 1, wherein the ceramic coating layer is an electronic component mainly composed of the same material as the crystalline inorganic compound.

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