JP4574269B2 - Manufacturing method of electronic parts - Google Patents

Description

  The present invention relates to a method for manufacturing electronic components such as capacitors, inductors, filters, circuit boards, and the like that are configured by combining a dielectric layer and a conductor layer having a predetermined pattern.

  Conventionally, dielectric materials have been used to form electronic components such as capacitors, inductors, filters, and circuit boards.

  As such a conventional electronic component, for example, a plurality of ceramic layers having a predetermined dielectric constant are laminated with a first internal electrode and a second internal electrode interposed therebetween, and A multilayer ceramic capacitor or the like is well known in which a pair of external electrodes electrically connected to the first and second internal electrodes are provided on the side surface and the main surface of the multilayer body, respectively. A predetermined voltage is applied between the first internal electrode and the second internal electrode via the pair of external electrodes, and a predetermined voltage is applied to the ceramic layer disposed between the first internal electrode and the second internal electrode. It functions as a capacitor by forming a capacitance of.

  The above-mentioned multilayer ceramic capacitor is manufactured through the following steps (for example, see Patent Document 1).

  First, an organic binder and an organic solvent are added to and mixed with a predetermined ceramic material powder to prepare a slurry-like inorganic composition, which is formed into a sheet with a predetermined thickness by a conventionally known doctor blade method, etc. Form a sheet.

  Next, a conductive paste mainly composed of a metal such as nickel is printed and applied in a predetermined pattern on the main surface of the obtained ceramic green sheet by screen printing or the like known in the art, and a plurality of these are stacked to make the ceramic green A laminate of sheets is formed.

Subsequently, the laminate is fired at a high temperature to form a conductor paste as an internal electrode and a ceramic green sheet as a ceramic layer. Finally, the conductor paste is applied to the end face of the laminate by a conventionally known dipping method or the like. A multilayer ceramic capacitor is manufactured by coating and baking to form external electrodes.
JP 2000-243650 A

  By the way, in recent years, with the miniaturization of electronic devices, there has been a demand for miniaturization of electronic components. In the case of the multilayer ceramic capacitor described above, individual ceramic layers and internal electrodes are formed thinly, and further, the number of layers is increased. Various studies have been made to increase the capacity.

  For example, in the above-described conventional multilayer ceramic capacitor, in order to reduce the thickness of the internal electrode, the average particle size of the metal powder contained in the conductor paste used for forming the internal electrode is, for example, about 0.3 μm It is important to make it extremely small.

  However, when the particle size of the metal powder contained in the conductor paste is extremely small, the dispersibility of the metal powder is deteriorated due to the aggregation of the metal powders in the conductor paste. It has a drawback that it is difficult to obtain a conductor paste having characteristics suitable for printing and the like.

  Even if a conductor paste having characteristics suitable for screen printing can be obtained by adjusting various components contained in the conductor paste, it is applied thinly on a ceramic green sheet. When firing, there is a disadvantage that the continuity of the internal electrode is significantly lost due to movement of the metal powder in the conductor paste during firing, and in the worst case, the internal electrode is divided. .

  Accordingly, in order to eliminate the above-mentioned drawbacks, it is conceivable to form a thin internal electrode by forming a metal plating film as an internal electrode in advance and transferring it to a ceramic green sheet.

  However, when an internal electrode is formed by transferring a previously formed metal plating film to a ceramic green sheet, there is a disadvantage that a large internal stress (tensile stress) is generated in the metal plating film when the metal plating film is deposited. . Therefore, when the surface of the base material used for deposition of the metal plating film is flat, if the metal plating film is peeled off from the base material, the metal plating film warps in a shape protruding in the direction opposite to the deposition direction. As a result, there is a disadvantage that deformation or cracking occurs in the ceramic green sheet or metal plating film during transfer to the ceramic green sheet, or delamination or cracking occurs during firing.

  Furthermore, since the thickness of the region without the internal electrode and the region with the internal electrode are different, when a plurality of ceramic green sheets are laminated, the thickness difference of each internal electrode is accumulated, and the delamination and the electrode are curved to cause a short Electrical failure may occur.

  The present invention has been devised in view of the above-mentioned drawbacks, and its purpose is to reduce the thickness of the conductor layer to produce a small electronic component, and to deform or crack the conductor layer or dielectric layer. An object of the present invention is to provide an electronic component manufacturing method that can effectively prevent the occurrence of defects.

The method for producing an electronic component of the present invention includes a step A in which a base having a convex curved surface is prepared, and a metal plating film is deposited on the surface of the base.
The metal plating film is transferred to a resin film, and then a dielectric slurry is attached so as to cover the metal plating film transferred to the resin film, and the resin film to which the dielectric slurry is attached is heated and dried. Forming a dielectric sheet in which a metal plating film is embedded by the step B,
And firing the dielectric sheet in which the metal plating film is embedded to obtain an electronic component having a portion in which the conductor layer is deposited on the dielectric layer. .

  The electronic component manufacturing method of the present invention is characterized in that the firing temperature of the dielectric sheet in the step C is lower than the melting point of the metal forming the metal plating film and higher than the recrystallization temperature of the metal. It is what.

  Furthermore, in the method of manufacturing an electronic component according to the present invention, the base body has a cylindrical shape or a columnar shape. In the step A, while rotating the base body around an axis, a part of the base body is used as a plating solution in a plating tank. The metal plating film is formed by immersing and applying an electric field to a plating solution between the substrate and the plating tank.

  Furthermore, in the method for manufacturing an electronic component according to the present invention, the base is cylindrical or columnar, and the curvature radius of the surface of the base is 50 mm to 2000 mm.

  Furthermore, the method for manufacturing an electronic component according to the present invention is characterized in that a mask layer for restricting a deposition region of the metal plating film is formed on the surface of the base.

  Furthermore, the electronic component manufacturing method of the present invention is characterized in that the mask layer is made of diamond-like carbon (DLC) or graphite-like carbon (GLC).

  Furthermore, the electronic component manufacturing method of the present invention is characterized in that an angle of a corner formed between the side surface and the lower surface of the mask layer is 90 degrees or less.

Still further, in the method of manufacturing an electronic component according to the present invention, the surface of the substrate on which the metal plating film is deposited has at least titanium aluminum nitride, chromium nitride, titanium nitride, titanium nitride chromium, titanium carbonitride, titanium carbide, or conductive DLC. It consists of one kind, and the surface roughness is 0.5 μm or less at the maximum height Ry, and the specific resistance of the substrate surface is 10 ⁻² Ωcm or less.

According to the present invention, a base having a convex curved surface is prepared, a metal plating film is deposited on the surface of the base, the obtained metal plating film is transferred onto a resin film, and then a dielectric sheet and Since the metal plating film is deposited, even when internal stress (tensile stress) is generated in the metal plating film, if the metal plating film is peeled off from the base, Deformation in the flattening direction. Therefore, when the metal plating film is transferred to the main surface of the resin film, it is possible to effectively prevent inconveniences such as deformation and cracks in the metal plating film, and the resin film after the metal plating film is transferred. since also substantially flat maintained, it is possible to control the thickness of the dielectric slurry over which is coated on the resin film with high precision, it is possible to improve the productivity of the electronic component.

  Further, the dielectric sheet obtained as described above has no step between the portion where the metal plating film is present and the portion where the metal plating film is not present, and even if a plurality of such dielectric sheets are laminated, the internal electrode Since the deformation is suppressed, it is possible to effectively prevent the occurrence of electrical failure and delamination.

  Furthermore, according to the present invention, the above-described metal plating film is subjected to heat treatment at a temperature higher than the recrystallization temperature of the metal forming the metal plating film and lower than the melting point during firing of the dielectric sheet. Thus, there is no inconvenience that the metal plating film is melted by the heat and the metal plating film is divided, and a conductor layer having excellent continuity can be formed. Here, the metal plating film becomes a conductor layer with excellent continuity, because the metal forming the metal plating film is recrystallized at the time of firing the dielectric sheet, so that the metal is moderately softened. This is because the (ceramic) particles in the dielectric sheet enter the surface of the metal plating film, whereby the adhesion between the metal plating film and the dielectric sheet is improved, and an electronic component with few structural defects is obtained.

  Furthermore, according to the present invention, by forming a mask layer for regulating the deposition region of the metal plating film on the surface of the substrate, the substrate is immersed in the plating solution without passing through complicated steps such as photoetching. Thus, a metal plating film having a desired pattern can be easily obtained simply by applying an electric field between the plating tank and the productivity of electronic parts can be improved.

  Furthermore, according to the present invention, if the mask layer is formed by DLC or GLC, a relatively thin and strong mask layer can be formed. Furthermore, such a film has a strong adhesion to the substrate and can provide sufficient electrical insulation, and can also have good releasability when the metal plating film is peeled from the substrate.

  Furthermore, according to the present invention, if the angle of the corner formed between the side surface and the lower surface of the mask layer is 90 degrees or less, the area of the lower surface of the metal plating film in contact with the substrate is the area of the upper surface. Therefore, when the metal plating film is transferred onto the resin film, the outer peripheral portion of the metal plating film is hardly caught by the max layer, so that the “missing” of the metal plating film can be improved.

Furthermore, according to the present invention, the surface of the substrate on which the metal plating film is deposited is formed of at least one of titanium aluminum nitride, chromium nitride, titanium nitride, titanium nitride chromium, titanium carbonitride, titanium carbide, and conductive DLC. When the surface roughness of the substrate surface is set to 0.5 μm or less at the maximum height Ry and the specific resistance is set to 10 ⁻² Ωcm or less, when the metal plating film is deposited on the surface of the substrate, The current density between the substrate and the plating tank becomes more uniform, and the thickness of the metal plating film can be made more uniform. In addition, in this case, the hardness of the substrate surface is high and the surface state is extremely smooth, so that the peelability of the metal plating film is also good.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing a multilayer ceramic capacitor as an electronic component manufactured by a manufacturing method according to an embodiment of the present invention. The multilayer ceramic capacitor 1 shown in FIG. It is composed of an internal electrode 3 as a layer, a dielectric layer 4 and an external electrode 5.

  The multilayer ceramic capacitor 1 is formed by alternately laminating internal electrodes 3 and dielectric layers 4 having a predetermined dielectric constant to form a rectangular parallelepiped-shaped multilayer body, and dielectric layers 4 on both upper and lower surfaces of the multilayer body. An insulating layer 2 made of the same material is formed, and an external electrode 5 electrically connected to the internal electrode 3 is attached and formed at both ends of the laminate.

  The dielectric layer 4 is formed of a ceramic material or an organic material. When made of a ceramic material, it is formed of, for example, barium titanate, calcium titanate, strontium titanate or the like. In the case of an organic material, it is made of, for example, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PP (polypropylene), PPS (polyphenylene sulfide) or the like. The thickness of the dielectric layer 4 is set to, for example, 1.0 μm to 4.0 μm per layer, and the number of stacked layers is set to, for example, 30 to 600 layers. As the material of the insulating layer 2, a ceramic material or an organic material similar to that of the dielectric layer 4 is used.

  The outer shape of the multilayer ceramic capacitor 1 is, for example, formed with dimensions of 1.2 mm in width, 2 mm in length, and 1.2 mm in height, and the number of stacked dielectric layers 4 and internal electrodes 3 is 30 to 600 layers. Set to

  The thickness of the internal electrode 3 is set to about 0.5 μm to 2.0 μm, and the thickness of the dielectric layer 4 is set to about 1.0 μm to 4.0 μm.

  The material and thickness of the dielectric layer 4, the number of stacked layers, the facing area of the internal electrode 3, and the like are appropriately determined depending on the desired capacitance.

The multilayer ceramic capacitor 1 applies a predetermined voltage to the adjacent internal electrodes 3-3 through the external electrodes 5, and applies a predetermined capacitance to the dielectric layer 4 disposed between the internal electrodes 3-3. Next, a method for manufacturing the above-described multilayer ceramic capacitor will be described with reference to FIGS.

  2 schematically shows a manufacturing apparatus used in the manufacturing method of the present invention, FIG. 3 is a plan view of the substrate 11 used in the manufacturing apparatus of FIG. 2 as viewed from the direction A in FIG. 2, and FIG. It is an expanded sectional view which shows the structure of the base | substrate surface used for this manufacturing apparatus.

<Step 1>
First, the metal plating film 9 having a convex curved surface is formed on the surface of the substrate 11 having a convex curved surface.

The base 11 is formed of, for example, stainless steel or the like so as to have a columnar shape or a cylindrical shape with a radius of curvature of 200 mm and a length of 200 mm, and a conductive film formed of titanium nitride having a specific resistance of 10 ⁻⁴ Ωcm on the surface. A film 7 is formed. A mask layer 8 made of DLC having a thickness of about 1 μm is formed on the conductive film 7 so that a plurality of rectangular regions having a width of 1.2 μm and a length of 2 μm are exposed. The angle α of the corner formed by the side surface and the lower surface (the surface of the base 11) of the mask layer 8 is set to 90 to 85 degrees, for example.

  Such a lower region of the base body 11 is immersed in the plating solution 17 injected into the plating tank 16, and the base body 11 is rotated around the axis of the rotary shaft 12 at a predetermined rotational speed. For example, a predetermined potential difference is provided between the plating tank 16 so that the current density is 2 A / dm 2 to 15 A / dm 2, and each rectangular region of the base 11 is subjected to electroplating to thereby form the base 11. A metal plating film 9 is formed along the convex curved surface.

  Thus, while rotating the cylindrical or columnar substrate 11 around its axis, the substrate 11 is immersed in the plating solution 17 in the plating tank 16 and an electric field is applied to the plating solution 17 between the substrate 11 and the plating tank 16. By forming the metal plating film 9 in this way, the metal plating film 9 can be formed continuously, thereby improving the productivity of the multilayer ceramic capacitor. In addition, in this case, since the current density between the base 11 and the plating tank 17 becomes substantially uniform, the metal plating film 9 can be formed with a substantially constant thickness.

  The rotating shaft 12 of the base 11 is supported at both ends by bearings (not shown) so that the base 11 does not move vertically and horizontally. By connecting the rotary shaft 12 and the main shaft of the prime mover and transmitting the rotational motion of the prime mover, the base 11 rotates around the axis at a predetermined speed.

  The rotating shaft 12 of the base 11 is electrically connected to a power supply device 13 via a rotating brush, thereby causing the base 11 to function as a cathode in electrolytic plating.

  On the other hand, the plating tank 16 holds the plating solution 17 therein and functions as an anode during electrolytic plating. The inner surface of the plating tank 16 is, for example, concentrically arranged with the outer surface of the substrate 11. A predetermined gap for filling the plating solution 17 is formed, for example, a gap of 5 to 30 mm.

  The plating solution 17 in the plating tank 16 is preferably always flowed in a predetermined direction by the circulation device 14 or the like when performing electroplating in order to obtain a uniform metal plating film 9. In order to deposit the nickel metal plating film 9 with high purity, it is preferable to form the inner surface of the plating tank 18 with a metal material having the same quality as the metal plating film 9.

  The metal plating film 9 formed on the surface of the base 11 as described above is pulled up from the plating solution 17 by the rotation of the base 11, and then washed and dried by the cleaning means 15.

  In addition to the stainless steel described above, a metal material having conductivity such as iron, aluminum, copper, nickel, titanium, tantalum, and molybdenum is used as the material of the base 11 described above. Among these, it is preferable to use stainless steel and titanium from the viewpoint of chemical resistance.

  The radius of curvature of the substrate surface is preferably set in the range of 50 mm to 2000 mm, and particularly preferably 50 mm to 500 mm from the viewpoint of ease of maintenance, productivity, and the like.

  Furthermore, the surface roughness of the above-described substrate surface is set to 0.5 μm or less, for example, at a maximum height Ry, and more preferably set to Ry 0.2 μm or less. Here, the surface roughness of the substrate surface is made small because when the thickness of the metal plating film 9 is reduced, the convex portions of the substrate 11 are transferred to the metal plating film 9 to form pinholes in the metal plating film 9. This is because structural defects may occur when this is heat-treated.

On the other hand, as the conductive film 7 formed on the surface of the substrate 11, it is preferable to use a film having a smooth film quality that is hard and has few film defects such as pinholes. The conductive film 7 preferably has a specific resistance of 10 ⁻² Ωcm or less. From the viewpoint of current density during electrolytic plating, the specific resistance is 10 ⁻³ Ωcm or less, for example, nitriding The conductive film 7 is preferably formed of titanium aluminum, chromium nitride, titanium nitride, titanium nitride chromium, titanium carbonitride, titanium carbide, conductive DLC, or the like. Of these materials, titanium aluminum nitride, chromium nitride, titanium nitride, titanium nitride chromium, and titanium carbonitride are particularly preferable in consideration of the peelability of the metal plating film 9, and titanium nitride is preferable from the viewpoint of durability. preferable.

  The conductive film 7 is formed by a conventionally known thin film forming method, for example, a sputtering method, an ion plating method, a chemical vapor deposition method (CVD) or the like.

  The mask layer 8 formed on the surface of the conductive film 7 is for regulating the deposition region of the metal plating film 9, and has sufficient electrical insulation so that the metal plating film is not deposited on the surface. The specific resistance is set to, for example, 104 Ωcm or more, and is formed of a film having a Vickers hardness Hv of 1000 or more and a friction coefficient μ of 0.3 or less. Examples of materials that can satisfy such various characteristics include amorphous DLC and GLC.

  Thus, by forming the mask layer 8 that regulates the deposition region of the metal plating film 9 on the surface of the base 11, the base 11 is immersed in the plating solution 17 without a complicated process such as photoetching. Thus, the metal plating film 9 having a desired pattern can be easily obtained simply by applying an electric field between the plating tank 16 and the productivity of the multilayer ceramic capacitor can be improved.

  The thickness of the mask layer 8 is arbitrarily set depending on the desired thickness of the metal plating film 9 and is preferably formed to be the same as the metal plating film 9 or slightly thicker than the metal plating film 9. This is to prevent the metal plating film 9 in the middle of deposition from spreading over the mask layer 8.

  The mask layer 8 is formed by depositing and forming DLC, GLC, etc. on the surface of the substrate 11 with a predetermined thickness by a conventionally known thin film forming method such as sputtering, ion plating, or CVD. The film is formed by processing the obtained film into a predetermined pattern having a plurality of openings corresponding to the deposition region of the metal plating film 9 by employing a conventionally known photo-etching method or the like.

  Since DLC and GLC used as the material of the mask layer 8 have high electric resistance, plating does not deposit on the surface of the mask layer 8, and the surface peelability is good, and the friction resistance Therefore, when the metal plating film 9 is transferred to the resin film 21 which is a transfer target in the present embodiment, the transfer target is hardly damaged, and the durability of the substrate 11 is improved and can be extended over a long period of time. Even when used repeatedly, the high-quality metal plating film 9 can be formed.

  The metal plating film 9 formed on the surface of the substrate 11 as described above is made of nickel, copper, silver, gold, platinum, palladium, chromium or the like, or an alloy of these metals. It is deposited and formed on the surface of the substrate 11.

  In the formation of the metal plating film 9, when the metal plating film 9 is formed of nickel, for example, a nickel sulfamate plating solution is used. By using the nickel sulfamate plating solution, the metal plating film 9 is formed. The metal plating film 9 with little internal stress can be formed. As the nickel sulfamate plating solution, for example, an aqueous solution having a composition of nickel chloride 30 g / liter, nickel sulfamate 300 g / liter, boric acid 30 g / liter is used, and the pH value thereof is, for example, 3.0. In order to keep the internal stress in the metal plating film 9 small, it is preferable to set the pH value to 3.5 to 4.0. The temperature of the plating solution is set to, for example, 25 ° C. to 70 ° C., and is preferably set to 45 ° C. to 50 ° C. in order to keep the internal stress in the metal plating film 9 small.

  Here, the plating solution 17 described above includes, as necessary, a pH buffer agent made of boric acid, nickel formate, nickel acetate or the like, a pit inhibitor made of sodium lauryl sulfate, or an aromatic hydrocarbon such as benzene or naphthalene. Stress reducing agent consisting of chemicals with sulfonic acid, sulfonate, sulphonamide, sulphonimide, etc., curing agent consisting of aromatic sulphonic acid and its derivatives, butynediol, 2-butyne 1.4 diol, ethylene cyanide Needless to say, a smoothing agent composed of hydrin, formaldehyde, coumarin, pyrimidine, pyrazole, imidazole, or the like may be added as appropriate. Specific examples of the stress reducing agent include saccharin, p-toluenesulfonamide, benzenesulfonamide, benzenesulfonimide, sodium benzenedisulfonate, sodium benzenetrisulfonate, sodium naphthalenedisulfonate, naphthalenetri Examples thereof include sodium sulfonate.

<Step 2>
Next, the metal plating film 9 obtained in step 1 is transferred onto the resin film 20.

  As the resin film 20, what formed the adhesive layer 21 of thickness 0.05micrometer-10 micrometers on the main surfaces, such as a polyethylene terephthalate film (PET film) of thickness 20-50 micrometers, for example is used. The pressure-sensitive adhesive layer 21 is formed by, for example, applying an acrylic (solvent), acrylic emulsion (water), butyral, phenol, silicon, or epoxy adhesive (solvent) to the main surface of a PET film or the like. It is preferable to adjust the adhesive strength after drying to be, for example, 0.1 N / cm.

  Such a resin film 20 is sequentially supplied to the substrate 11 side by the delivery unit 22, and the side on which the adhesive layer 21 is formed is applied to the surface of the substrate 11 on which the metal plating film 9 is formed by the pressure roller 23. For example, the metal plating film 9 is transferred onto the resin film 20 by applying pressure with a pressing force of 10N. Thereafter, the resin film 20 is wound up by the winding unit 24 at the same speed as the peripheral speed of the substrate surface.

  At this time, if the angle α of the corner formed between the side surface and the lower surface of the mask layer 8 is 90 degrees or less, the area of the lower surface of the metal plating film 9 in contact with the substrate 11 is larger than the area of the upper surface. Therefore, when the metal plating film 9 is transferred to the resin film 20 or the like, the outer peripheral portion of the metal plating film 9 is hardly caught by the max layer 8 and the “plating” of the metal plating film 9 is improved. Can do.

  The adhesive layer 21 is made of a material that is reliably pyrolyzed at a relatively low temperature. Specifically, even if it adheres to the metal plating film 9, it is an acrylic (solvent) that decomposes thermally upon firing. Type), acrylic emulsion type (water type), and butyral type adhesives are preferred, and among these, it is particularly preferred to use acrylic adhesives with good peelability. The pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer 21 is, for example, 0.005 N / cm to 1.0 N / cm, and from the viewpoint of transferability, a pressure of 0.01 N / cm to 1.0 N / cm is used. In particular, from the viewpoint of releasability, it is preferable to use one having a density of 0.01 N / cm to 0.2 N / cm.

  Further, as the pressure roll 23, a surface portion formed of an elastic material such as urethane rubber coat, neoprene rubber coat, natural rubber coat, etc. so that the resin film 20 can be uniformly pressed against the base 11. It is preferable to use it.

<Step 3>
Then, the main surface of the resin film 20 in which the metal plating film 9 is transferred, the ceramic slurry over 26 was applied so as to cover the metal plating film 9, forming a ceramic green sheet 26 'by drying it To do.

The ceramic slurry over 26, for example, barium titanate, calcium titanate, dielectric material powder in a suitable organic solvent mainly composed of strontium titanate, mud漿状was added and mixed an organic binder or the like and Nasukoto Is applied to the resin film 20 to a thickness of, for example, 1 μm to 20 μm using the coating means 27, and then dried by a drying means 28 of, for example, 70 ° C. to 85 ° C. heated at a temperature of about 30 seconds to 60 seconds, the ceramic green sheet 26 'is obtained by evaporating a number of organic solvent present in the ceramic slurry over 26.

  As the drying means 28, a drying means using hot air, infrared rays, microwaves, or the like, or a drying means using a combination of these is preferably employed.

  As a result, a ceramic green sheet 26 ′ in which the metal plating film 9 is embedded is formed on the main surface of the resin film 20, and the metal plating film 9 and the ceramic green sheet 26 ′ are integrated.

  Such a ceramic green sheet 26 ′ has no step between the portion where the metal plating film 9 is present and the portion where the metal plating film 9 is not present, and a plurality of obtained ceramic green sheets 26 ′ are laminated in a laminating step 4 described later. However, since the deformation of the internal electrode is suppressed, it is possible to effectively prevent the occurrence of electrical failure and delamination.

<Step 4>
Next, a plurality of ceramic green sheets 26 ′ with the metal plating film 9 obtained in the above-described step 3 are prepared, and a laminated body is formed by pressing and laminating them together.

Such a laminate is, for example, temporarily pressure-bonded at a pressure of 0.9 MPa while being heated at a temperature of 60 ° C., and then the laminate is heated at a temperature of 70 ° C. and a pressure of 50 MPa by a conventionally known hydrostatic pressure press or the like. The ceramic green sheet 26 ' with the metal plating film 9 to be formed is formed by pressure bonding to each other.

<Step 5>
Finally, the laminate obtained in step 4 is cut into a predetermined shape and fired at a high temperature.

What is important here is that the firing temperature of the laminate is fired at a temperature lower than the melting point of the metal forming the metal plating film 9 and higher than the recrystallization temperature of the metal. The sheet 26 ′ becomes the dielectric layer 4 of the multilayer ceramic capacitor, and the metal plating film 9 becomes the internal electrode 3.

  Here, metal recrystallization is a phenomenon in which when a processed metal material is heated, the metal is suddenly softened at a certain temperature and stabilized so as to reduce internal strain. The temperature at which this recrystallization starts is called the recrystallization temperature. For example, in the case of nickel, the recrystallization temperature is 530 ° C. to 660 ° C., the melting point is 1458 ° C., in the case of copper, the recrystallization temperature is 200 ° C. to 250 ° C., the melting point is 1083 ° C., and in the case of gold, the recrystallization temperature is about The melting point is 200 ° C. and 1060 ° C. Therefore, when the metal plating film 8 is made of nickel, the laminate is fired at a temperature of 1300 ° C., for example.

  By firing the metal plating film 9 at a temperature lower than the melting point of the metal forming the plating film 9 in this way, the disadvantage that the metal plating film 9 melts and the metal plating film 9 is divided during firing is ensured. The internal electrode 3 which is prevented and has excellent continuity can be formed.

In this case, since the firing temperature of the laminate is set higher than the recrystallization temperature of the metal forming the metal plating film 9, recrystallization of the metal forming the metal plating film 9 during firing is performed. As the metal advances, the metal softens moderately, and the ceramic particles in the ceramic green sheet 26 ′ enter the surface of the metal plating film 9, thereby improving the adhesion between the metal plating film 9 and the ceramic green sheet 26 ′. As a result, a multilayer ceramic capacitor with few structural defects can be obtained.

<Step 6>
Finally, a conductive paste for external electrodes is applied to both ends of the multilayer body, fired, and further subjected to plating to form external electrodes 5, thereby completing a multilayer ceramic capacitor 1 as a product.

According to the manufacturing method of the first embodiment as described above, the metal plating film 9 having a convex curved section is formed on the surface of the substrate 11 having a convex curved surface, and the obtained metal plating film 9 is formed into a ceramic green sheet. Since it is transferred to the main surface of 26 ' , when the metal plating film 9 is deposited, the metal plating film 9 is peeled off from the base 11 even if internal stress (tensile stress) is generated in the metal plating film 9. The convex-curved metal plating film 9 is deformed in a flattening direction. Therefore, when the metal plating film 9 is transferred to the main surface of the resin film 20, the disadvantage that the metal plating film 9 is deformed or cracked is effectively prevented. Since the thickness of the ceramic slurry 26 applied on the resin film 20 can be controlled with high accuracy, the productivity of the multilayer ceramic capacitor 1 can be improved. it can.

  In addition, this invention is not limited to the above-mentioned embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.

For example, in the above-described embodiment has described the case of applying the ceramic slurry over 26 by conventionally known die coating on the resin film 20, instead of this, a roll coating method or a screen printing method the ceramic slurry over 26 You may make it apply | coat on the resin film 20 by other application | coating methods, such as.

Also in Figure 2, the coating unit 27 is arranged below the resin film 20, but a ceramic slurry over 26 shows the case of coating from below of the resin film 20, the ceramic slurry over 26 from above the resin film 20 coating or, may be applied or from the side of the resin film 20.

Further in the embodiment described above, by placing the doctor blade in the downstream side of the resin film 20 to the coating unit 27, so as to uniform the thickness of the ceramic slurry over 26 to be applied on the resin film 20 Also good.

  Further, in the above-described embodiment, the case where the multilayer ceramic capacitor is manufactured has been described as an example. However, even in the case where other electronic components other than the multilayer ceramic capacitor, for example, other electronic components such as an inductor, a filter, and a circuit board are manufactured. Needless to say, the present invention is applicable.

It is sectional drawing which shows the multilayer ceramic capacitor as an electronic component manufactured with the manufacturing method which concerns on one Embodiment of this invention. It is a figure which shows typically the structure of the manufacturing apparatus used for the manufacturing method of this invention. It is the top view which looked at the base | substrate 11 used for the manufacturing apparatus of FIG. 2 from the A direction of FIG. It is an expanded sectional view which shows the structure of the base surface used for the manufacturing apparatus of FIG.

Explanation of symbols

1 ... Multilayer ceramic capacitor (electronic component)
2 ... Insulating layer 3 ... Internal electrode (conductor layer)
4. Ceramic layer (dielectric layer)
DESCRIPTION OF SYMBOLS 5 ... External electrode 7 ... Conductive film 8 ... Mask layer 9 ... Metal plating film 11 ... Base | substrate 12 ... Rotating shaft 13 ... Power supply device 14 ... Circulating device 15 ... Drying section 16 ... Plating tank (anode)
17 ... plating solution 20 ... resin film 21 ... adhesive layer 22 ... feeding unit 23 ... pressing roller 24 ... take-up unit 26 ... ceramic slurry over (dielectric slurry over )
26 '・ ・ Ceramic green sheet (dielectric sheet)
27 ... Application means 28 ... Drying means

Claims (8)

Preparing a substrate having a convex curved surface, and depositing a metal plating film on the surface of the substrate;
The metal plating film is transferred to a resin film, and then a dielectric slurry is attached so as to cover the metal plating film transferred to the resin film, and the resin film to which the dielectric slurry is attached is heated and dried. Step B of forming a dielectric sheet with a metal plating film embedded therein,
And firing the dielectric sheet in which the metal plating film is embedded to obtain an electronic component having a portion in which a conductor layer is deposited on the dielectric layer. 2. The electronic component according to claim 1, wherein the firing temperature of the dielectric sheet in the step C is lower than the melting point of the metal forming the metal plating film and higher than the recrystallization temperature of the metal. Production method. The substrate has a cylindrical or columnar shape, and in the step A, while rotating the substrate around an axis, a part of the substrate is immersed in a plating solution of the plating tank, and the substrate and the plating tank The method of manufacturing an electronic component according to claim 1, wherein the metal plating film is formed by applying an electric field to the plating solution between the two. 4. The method of manufacturing an electronic component according to claim 1, wherein the base body has a cylindrical shape or a columnar shape, and a curvature radius of a surface of the base body is 50 mm to 2000 mm. . 5. The method of manufacturing an electronic component according to claim 1, wherein a mask layer for regulating a deposition region of the metal plating film is formed on a surface of the base. 6. The method of manufacturing an electronic component according to claim 5, wherein the mask layer is made of diamond-like carbon (DLC) or graphite-like carbon (GLC). 7. The method of manufacturing an electronic component according to claim 5, wherein an angle of a corner formed between the side surface and the lower surface of the mask layer is 90 degrees or less. The surface of the substrate on which the metal plating film is deposited is made of at least one of titanium aluminum nitride, chromium nitride, titanium nitride, titanium nitride chromium, titanium carbonitride, titanium carbide, and conductive DLC, and has a maximum surface roughness. 8. The method of manufacturing an electronic component according to claim 1, wherein Ry is 0.5 μm or less and a specific resistance of the substrate surface is 10 ⁻² Ωcm or less.

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