Manufacturing method of multilayer inductor

Abstract

To provide a silver paste containing powder with high concentration and excellent in printability and, owing to the same, a silver conductor film having a high filling rate and film density to exhibit high electric conductance and excellent in migration resistance.SOLUTION: A silver paste comprises at least a silver powder, binder resin and organic solvent. Provided that a specific surface area of the silver powder is SBET(m2 / g) and a content percentage of the binder resin to the silver powder is CBND (mass%), then CBND / SBET has a value of 2.0-3.4, the silver powder has a copper content of 10-5000 mass ppm and the silver paste has a dry film density of 7.50 g / cm3 or higher.

Description

[Technical Field]

[0001] The present invention relates to a sintered silver paste containing silver powder and used to form internal and external electrodes in ceramic electronic components such as multilayer ceramic capacitors, inductors, and actuators. [Background technology]

[0002] Conductive pastes containing metal powders have been widely used to form internal and external electrodes of electronic components. This is partly because, compared with conductive inks using organometallic compounds, conductive pastes containing metal powders are compatible with various printing methods, such as screen printing, offset printing, gravure printing, inkjet printing, dipping, dispensing, brush coating, and spin coating, and can form thick films in a single coating printing run, making them advantageous in terms of achieving high conductivity.

[0003] In order to obtain high conductivity, it is preferable that the conductive paste contains a high content of metal powder, and it is also desirable that the coating film obtained by printing the paste is dense and high-density. A high content of metal powder will ensure reliable conductivity even in the formation of even finer patterns in the future.

[0004] For example, Patent Document 1 (JP 2005-174824 A) discloses an invention that uses metal colloid particles instead of metal powder to obtain a highly dense and conductive film, and uses an organometallic compound in combination with these to fill the gaps between the metal colloid particles with the organometallic compound, thereby increasing the density.

[0005] However, because metal colloid particles and organometallic compounds contain a large amount of organic components, when they are used as the main conductive component, the metal component content is lower than that of pastes using metal powders, making it impossible to obtain a conductive film with low specific resistance. Moreover, it is difficult to adapt to the wide variety of printing methods mentioned above. To solve this problem, large amounts of binder resins, viscosity modifiers, etc. are added to the paste, which further reduces the metal ratio in the coating film.

[0006] On the other hand, when metal powder is used as the conductive component of the paste, a conductive film with low resistivity can be obtained if the content of the metal powder is high, but the higher the content of the metal powder, the worse the printability becomes. Therefore, in the case of silver paste, for example, the highest coating density described in Patent Document 2 is 5.4 g / cm. 3 The maximum coating density described in Patent Document 3 is 5.70 g / cm 3 In addition, Patent Document 4 describes a nickel paste with a dry film density of 6.2 g / cm. 3 Examples are disclosed.

[0007] As described above, when attempting to obtain a dense coating film with high conductivity in a conductive paste, printability is sacrificed, and the two are in a trade-off relationship. Therefore, there is a demand for a conductive paste that can simultaneously achieve dense coating film formation and good printability.

[0008] There are known examples of using two types of silver powder with different particle sizes, large and small, to obtain a dense coating film (Patent Document 5 and Patent Document 6). However, a phenomenon called migration is known to occur, particularly in the case of silver pastes that use silver powder, and the more small-diameter silver powder (e.g., less than 0.5 μm) contained in the silver paste, the more likely migration occurs.

[0009] Conventionally, various countermeasures have been attempted to suppress migration, such as adding a migration inhibitor containing fluorine to silver paste (Patent Document 7) or adding a mixed powder, alloy powder, or compound powder containing the three elements copper, tin, and manganese to silver powder (Patent Document 8). [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-174824 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-131950 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-192565 [Patent Document 4] Japanese Patent Application Laid-Open No. 2004-220807 [Patent Document 5] Japanese Patent Application Laid-Open No. 2003-280179 [Patent Document 6] Japanese Patent Application Laid-Open No. 2005-203304 [Patent Document 7] Japanese Patent Application Laid-Open No. 2014-197483 [Patent Document 8] International Publication No. 2014 / 061765 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0011] However, adding a large amount of components other than the silver powder described above to the paste for the purpose of preventing migration is not preferable in terms of obtaining high conductivity.

[0012] Therefore, an object of the present invention is to solve these problems. That is, an object of the present invention is to provide a silver paste that contains a high concentration of silver powder and has excellent printability, and thereby to provide a silver conductor film that has a high filling rate and film density, exhibits high conductivity, and has excellent migration resistance. [Means for solving the problem]

[0013] As a result of intensive research to solve the above problems, the present inventors have found that even when a paste contains a high concentration of silver powder, by controlling the specific surface area of ​​the silver powder and the solid component of the binder resin within a specific range, a dense dry film can be obtained without sacrificing printability, and further, by simply adding the minimum necessary amount of copper component to the silver powder, migration can be effectively suppressed. This discovery led to the completion of the present invention. That is, the present invention (1) is a silver paste containing at least silver powder, a binder resin, and an organic solvent, The specific surface area of ​​the silver powder is S BET (m 2 / g), and the content ratio of the binder resin to the silver powder is C BND (mass%), C BND / S BET The value of is 2.00 to 3.40, The copper content of the silver powder is 10 to 5000 ppm by mass, The dry film density of the silver paste is 7.50 g / cm 3 That is all, The present invention provides a silver paste characterized by the following:

[0014] In addition, the present invention (2) is a method for producing a film having a dry film density of 7.60 g / cm. 3 The present invention provides a silver paste according to (1) characterized by the above.

[0015] The present invention (3) also provides the above-mentioned C BND / S BET The present invention provides a silver paste according to either (1) or (2), characterized in that the value of (1) is 2.50 to 3.10.

[0016] The present invention (4) also provides the silver paste of any one of (1) to (3), wherein the silver powder contains 30 to 500 ppm by mass of copper.

[0017] In addition, the present invention (5) is characterized in that the content C of the silver powder relative to the silver paste AG The present invention provides a silver paste according to any one of (1) to (4), characterized in that the content of the silver in the silver paste is 80.00 to 97.00 mass %.

[0018] In addition, the present invention (6) provides a silver paste having a silver powder content C AG The present invention provides a silver paste according to (5), characterized in that the content of the silver in the silver paste is 92.00 to 96.00 mass %.

[0019] In addition, the present invention (7) provides a method for manufacturing a silver powder having a specific surface area S BET 0.10~0.30m 2 The present invention provides a silver paste according to any one of (1) to (6), characterized in that the silver paste is a powder having a silver content of 1 / g.

[0020] The present invention (8) provides a silver paste according to any one of (1) to (7), characterized in that, when D10 and D50 are the 10% and 50% values, respectively, of the volume-based cumulative fraction of the silver powder measured by laser diffraction particle size distribution measurement, D10 is 1.00 to 3.00 μm and D50 is 3.00 to 7.00 μm.

[0021] The present invention (9) also provides the silver paste according to (8), wherein the D10 is 1.20 to 2.00 μm.

[0022] The present invention (10) also provides the silver paste according to either (8) or (9), wherein the D50 is 3.90 to 5.00 μm.

[0023] The present invention (12) also provides a silver paste according to any one of (1) to (10), which is used to form a conductive film by heat treatment at 700° C. or less. [Effects of the Invention]

[0024] According to the present invention, a silver paste containing a high concentration of silver powder and having excellent printability is provided, and thereby a silver conductor film having a high filling rate and film density, high conductivity, and excellent migration resistance can be provided. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 2 is an external view of a laminated inductor. [Figure 2] FIG. 2 is an exploded view of an element part of the laminated inductor. [Figure 3] FIG. 2 is a simplified cross-sectional view taken along the XX axis of FIG. 1. [Figure 4] FIG. 4 is a simplified enlarged view of a part of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0026] The silver paste of the present invention contains at least silver powder, a binder resin, and an organic solvent, The specific surface area of ​​the silver powder is S BET (m 2 / g), and the content ratio of the binder resin to the silver powder is C BND (mass%), C BND / S BET The value of is 2.00 to 3.40, The copper content of the silver powder is 10 to 5000 ppm by mass, The dry film density of the silver paste is 7.50 g / cm 3 That is all, This is a silver paste characterized by the following.

[0027] The silver paste of the present invention contains at least silver powder, a binder resin, and an organic solvent.

[0028] The silver powder according to the silver paste of the present invention, i.e., the silver powder contained in the silver paste of the present invention, is not particularly limited in shape, particle size, production method, etc. as long as it can satisfy the requirements described below.

[0029] The copper content of the silver powder in the silver paste of the present invention is 10 to 5000 ppm by mass, preferably 30 to 500 ppm by mass. When the copper content of the silver powder is within the above range, migration is less likely to occur. On the other hand, if the copper content of the silver powder is below the above range, migration is more likely to occur. From the viewpoint of migration resistance, there is no upper limit to the copper content, but if it exceeds the above range, the resistivity increases. Therefore, in the present invention, the copper content of the silver powder is within the range of 10 to 5000 ppm by mass. In this specification, the symbol "~" indicating a numerical range indicates a range including the numerical values ​​written before and after the symbol "~", unless otherwise specified. That is, for example, the expression "10 to 5000" is synonymous with "10 or more and 5000 or less" unless otherwise specified.

[0030] The binder resin for the silver paste of the present invention is not particularly limited, and examples thereof include binder resins used in ordinary silver pastes, such as cellulose resins, acrylic resins, phenolic resins, epoxy resins, urethane resins, polyester resins, and polyethylene resins.

[0031] The organic solvent for the silver paste of the present invention is not particularly limited, and examples thereof include organic solvents commonly used in silver pastes, such as alcohol-based, ether-based, ester-based, and hydrocarbon-based organic solvents, water, and mixtures thereof.

[0032] The specific surface area of ​​the silver powder is S BET (m 2 / g), and the content ratio of binder resin to silver powder is C BND (mass%), the "C" of the silver paste of the present invention BND / S BET The value of " is 2.00 to 3.40, preferably 2.50 to 3.10. BND / S BET When the value of C is within the above range, the silver content in the silver paste can be increased while maintaining good printability, and as a result, a conductive film with high dry film density, denseness, and high conductivity can be obtained.BND / S BET If the value of C is less than the above range, the amount of binder resin covering the silver surface will be insufficient, which will impair the dispersibility of silver particles in the silver paste and reduce the strength of the dried film. For example, in the case of screen printing, this will result in poor screen removal and difficulty in maintaining the shape of the coating film after printing and drying. BND / S BET If the value of S exceeds the above range, a large amount of organic solvent will be used to maintain appropriate printability, and the silver content in the silver paste will decrease, resulting in a low dry film density and poor compactness and conductivity. BET (m 2 / g) is the specific surface area determined by the BET method in which helium gas is adsorbed on the surface of silver powder. BND (% by mass) is the content ratio (% by mass) of binder resin relative to silver powder, which is calculated by the formula "(content of binder resin in silver paste / content of silver powder in silver paste) x 100".

[0033] The dry film density of the silver paste of the present invention is 7.50 g / cm 3 The lower limit of the dry film density of the silver paste of the present invention is preferably 7.60 g / cm. 3 , particularly preferably 7.80 g / cm 3 The upper limit of the dry film density of the silver paste of the present invention is preferably as high as possible as long as printability is good. 3 ) and, taking into consideration workability and productivity, a realistic limit is 8.50 g / cm 3The upper limit is about 100%. Regarding the method for controlling the dry film density, the dry film density can be controlled by widely known general techniques. Examples of such methods include adjusting the particle size distribution of the silver powder and its surface condition (smoothness, presence or absence of surface treatment, etc.), changing the binder resin or organic solvent used, or, if a dispersant is added to the paste, changing the type and amount of the dispersant added. In the present invention, the dry film density refers to the density of a dry film obtained by drying a silver paste coating without applying pressure. In the example described below, the silver paste to be measured is applied to a PET film to a thickness of approximately 150 μm, and then temporarily dried at 80 ° C. for 10 minutes. The PET film is then punched into a circle with a diameter of 15 mm, and the film is further dried at 150 ° C. for 1 hour. The PET film is then peeled off, and the mass W and volume V of the resulting dry film are measured to calculate W / V.

[0034] In the silver paste of the present invention, C BND / S BET When the value of and the copper content in the silver powder satisfy the above-mentioned ranges and the dry film density is within the above-mentioned range, a dense, highly conductive film can be obtained. As a result, the silver paste of the present invention can form a dense, low-resistivity conductor film, while also providing a conductor film with excellent printability and coating film shape, and furthermore, excellent migration resistance and reduced short-circuiting between conductor films. In the experimental examples described below, after screen printing the silver paste of the present invention on a substrate to be printed, the closer the contact angle (rectangleness) between the substrate and the coating film is to 90°, the more favorable the coating film shape (printing pattern) and the better the printability.

[0035] The higher the silver content in the silver paste, the more conductive the film obtained, but if it is too high, the printability will be reduced. AGis preferably 80.00 to 97.00 mass%, and particularly preferably 92.00 to 96.00 mass%, in that both conductivity and printability can be improved. The silver content (mass%) in the silver paste is the content ratio of silver powder to the silver paste calculated by the formula "(silver powder content / silver paste mass) × 100".

[0036] The specific surface area S of the silver powder in the silver paste of the present invention BET is 0.10~0.30m 2 / g. The specific surface area S BET 0.10~0.30m 2 / g, the content of small-diameter silver powder, which is prone to migration, is low, so short circuits between conductor films are more effectively suppressed. BET is particularly preferably 0.12 to 0.20 m 2 / g. The shape of the silver powder may be granular, flake-like, or irregular, but is preferably spherical. In the present invention, "spherical" refers to a particle in which the average aspect ratio of any 50 particles within the field of view is within the range of 1.0 to 1.5 when observed with a scanning electron microscope (SEM). In the present invention, it is particularly preferred that the average aspect ratio is within the range of 1.0 to 1.3.

[0037] Furthermore, the silver powder used in the silver paste of the present invention preferably has a D10 of 1.00 to 3.00 μm and a D50 of 3.00 to 7.00 μm, and more preferably a D10 of 1.20 to 2.00 μm and a D50 of 3.90 to 5.00 μm. When the D10 and D50 of the silver powder satisfy the above requirements, the dry film density is increased and the content of small-diameter silver powder that is prone to migration is reduced, thereby more effectively suppressing short circuits between conductor films.

[0038] Furthermore, the silver powder used in the silver paste of the present invention is preferably a mixed powder containing two or more types of silver powders with different average particle sizes (D50). By using a mixed powder containing two or more types of silver powders with different average particle sizes (D50), it becomes easier to obtain a conductive film with a high dry film density and a dense, highly conductive film.

[0039] The silver powder for the silver paste of the present invention may be: (a) a first silver powder having a D50 in the range of 3.50 to 7.50 μm, preferably 3.70 to 7.50 μm, and particularly preferably 4.00 to 6.00 μm; (b) a second silver powder having a D50 of 0.80 to 2.70 μm, which may be 0.80 to 2.00 μm, and preferably in the range of 0.80 to 1.80 μm; In this case, the specific surface area S BET The various physical quantities, such as D50, D10, copper content, etc., of the mixed powder as a whole after mixing two or more types of silver powders may be within the above-mentioned numerical ranges. Note that, because the second silver powder tends to lower the D10 value of the mixed powder as a whole, it is preferable to use a second silver powder whose D10 is adjusted to 0.70 μm or more.

[0040] In the present invention, the method for producing silver powder is not particularly limited, but for example, conventionally known atomization methods, wet reduction methods, CVD methods, PVD methods such as those described in Japanese Patent No. 3541939, spray pyrolysis methods described in Japanese Patent Publication No. 63-31522, and "method for thermally decomposing a thermally decomposable metal-containing compound in a gas phase" as described in Japanese Patent No. 3812359. Silver powder can be produced by such methods. Among these, the above-mentioned PVD method, spray pyrolysis method, or "method for thermally decomposing a thermally decomposable metal-containing compound in a gas phase" production method is preferred in that it can easily produce spherical, highly crystalline, and uniform silver powder of particle size.

[0041] In the silver paste of the present invention, the content ratio of binder resin to silver powder is C BDN is preferably 0.430 to 0.750 mass %, particularly preferably 0.440 to 0.600 mass %.

[0042] The silver paste of the present invention can appropriately contain, as necessary, glass frit, inorganic compounds such as metal oxides, and additives that are typically used in silver pastes, such as plasticizers, viscosity modifiers, surfactants, dispersants, and oxidizers.

[0043] The silver paste of the present invention is produced in a conventional manner by kneading together silver powder, a binder resin, an organic solvent, and, as necessary, inorganic oxides, additives, and the like, and uniformly dispersing them to prepare a paste having a rheology suitable for screen printing and other printing methods.

[0044] The silver paste of the present invention is used to form internal electrodes, external electrodes, and thick-film conductor circuits in electronic components such as multilayer ceramic capacitors, inductors, actuators, etc. In particular, the silver paste of the present invention is suitably used to form internal electrodes of powder magnetic core materials, particularly multilayer inductors in which soft magnetic metal particles are used as the magnetic material.

[0045] To facilitate understanding of the "printability" in the present invention, the following description will be given taking a laminated inductor as an example. Typically, a laminated inductor 10 is composed of an element body 11 and a first external electrode 12 and a second external electrode 13 covering a pair of end faces of the element body 11, as shown in FIG.

[0046] As shown in FIG. 2, the element body 11 is constructed by laminating magnetic layers A1 to A20 and internal electrode layers B1 to B17. The magnetic layers A1 to A20 are obtained by kneading core-shell composite particles, in which the surfaces of soft magnetic iron alloy particles, primarily composed of iron, are coated with an insulating film made of resin, oxide, or the like, together with an appropriate binder resin and organic solvent to prepare a magnetic paste, which is then formed into a sheet and dried. The internal electrode layers B1 to B17 are formed in a predetermined pattern on the surfaces of the magnetic layers A3 to A19 by screen printing. The silver paste of the present invention is used to form these internal electrode layers. One end of the internal electrode layer B1 is exposed at the end face of the magnetic layer A3 and is electrically connected to the external electrode 12, and one end of the internal electrode layer B17 is similarly electrically connected to the external electrode 13. The internal electrode layers B1 to B17 are electrically connected via through-hole electrodes C1 to C16 formed through the magnetic layers A3 to A19 in the thickness direction, and the internal electrode layers B1 to B17 are generally coil-shaped in the stacking direction. When the internal electrode layers B1 to B17 are formed on the magnetic layers A3 to A19, it is preferable to further stack a magnetic layer (not shown) on the magnetic layers A3 to A19, the magnetic layer having a shape that can fill in the steps caused by the film thickness of the internal electrode layers B1 to B17. The element body 11, in which the magnetic layers A1 to A20 and the internal electrode layers B1 to B17 are stacked, undergoes a thermocompression bonding process and is sintered at approximately 700°C. External electrodes 11 and 12 are then formed on a pair of ends to form a multilayer inductor. The external electrodes may be formed using the silver paste of the present invention or a conductive paste primarily containing nickel or copper.

[0047] The cross section of the multilayer inductor shown in Figure 1 manufactured in this manner along the XX axis is shown in Figure 3, and an enlarged portion of it is shown in Figure 4. Note that both Figures 3 and 4 are simplified diagrams and do not necessarily match the content and structure shown in Figure 2, including the number of layers. As shown in Figure 3, the cross section of the internal electrode layer is ideally rectangular. However, in reality, when the silver paste is applied and printed onto the substrate, the viscosity and fluidity of the paste affect the cross section, so the actual cross section of the internal electrode layer is usually approximately trapezoidal, as shown in Figure 4. To achieve a rectangular shape, it is necessary to obtain a paste with high fluidity when printing and that quickly exhibits high viscosity after printing. However, there are an extremely large number of parameters that must be controlled in the paste, and these parameters interact in complex ways, so it is no exaggeration to say that there are almost no cases in which the expected results and characteristics are obtained.

[0048] As described above, in this specification, "printability" means not only that the composition exhibits appropriate fluidity when printed by screen printing, gravure printing, or the like, and can be printed, but also that the composition quickly exhibits high viscosity after printing, and a coating film (conductor film) having a shape closer to a rectangle can be obtained.

[0049] The silver paste of the present invention is suitable for use as a fired silver paste used to form internal and external electrodes in ceramic electronic components such as multilayer ceramic capacitors, inductors, actuators, etc. For example, the silver paste of the present invention is used to form a conductor film by heat treatment at 700°C or less.

[0050] The present invention will be described below based on specific experimental examples, but the present invention is not limited to these. [Example]

[0051] <Manufacturing of silver powder> First, silver powders 1 to 21 listed in Table 1 were prepared based on the spray pyrolysis method described in Japanese Patent Publication No. 63-31522. That is, for silver powders 6, 8, 13 to 17, and 19 to 21, an aqueous solution in which silver salt and copper salt were weighed and dissolved was spray pyrolyzed, and the collected silver powder was classified to adjust the D10 and D50 values ​​so that the copper content in the resulting silver powder would be the value listed in the "All Silver Powders" column in Table 1. Furthermore, for silver powders 1 to 5, 7, 9 to 12, and 18, an aqueous solution in which silver salt and copper salt were weighed and dissolved was spray pyrolyzed, and the collected silver powder was classified to adjust the D10 and D50 values ​​so that the copper content in the resulting silver powder would be the value listed in the "First Silver Powder" or "Second Silver Powder" column in Table 1. The first silver powder and second silver powder obtained were then mixed to obtain a mixed powder as silver powder. For each silver powder, the 10% value (D10) and 50% value (D50) of the volume-based cumulative fraction were determined using a laser diffraction particle size distribution analyzer. In addition, the specific surface area (S BET ) was measured, and the aspect ratio of 50 arbitrarily selected silver powder particles was measured by SEM (scanning electron microscope) image observation, and the average value was calculated. The results are shown in Table 1.

[0052] [Table 1]

[0053] (Examples 1 to 13 and Comparative Examples 1 to 9) The silver powder listed in Table 1 was mixed with the content C listed in Table 2. AG and ethyl cellulose was added at a content C shown in Table 2. BND The remainder was terpineol (TPO), and these were kneaded to prepare silver paste samples a to u. Next, each of the silver paste samples a to u was applied to a PET film in an area of ​​20 mm x 20 mm x 151 μm, dried at 80°C for 10 minutes, punched out using a 15 mm diameter punch, and further dried at 150°C for 1 hour. The mass W and volume V of the resulting dried film were then measured, and the dry film density was calculated using the W / V formula. The results are shown in Table 2. The acceptable standard for dry film density was 7.50 g / cm. 3 That's all. Next, the silver paste sample was applied and printed onto a ceramic substrate in the shape of a rectangular parallelepiped measuring 60 mm x 0.6 mm x 40 μm, and fired at 650°C in an oxidizing atmosphere (air) to form a conductive film. After that, the electrical resistance was measured using the four-terminal method, and the specific resistance was calculated. The results are shown in Table 2. The pass standard for specific resistance was 2.00 μΩ·cm or less, and preferably 1.90 μΩ·cm or less.

[0054] [Table 2] 1) Content of silver powder in silver paste: (silver powder / silver paste) x 100 2) Ethyl cellulose content relative to silver powder: (Ethyl cellulose / silver powder) x 100

[0055] (Examples 14 to 26, Comparative Examples 10 to 18) A rectangular parallelepiped pattern was formed on a 30 μm-thick magnetic layer prepared in advance using the silver paste samples a to u by screen printing, and then a magnetic layer was printed to fill in the steps caused by the thickness of the pattern. Three such sets were stacked, and magnetic layers for covers were stacked on the top and bottom. The stacks were then thermocompressed, degreased in an oxidizing atmosphere, and fired at 650°C to obtain a laminate. Next, the printability was evaluated using the obtained laminate. Specifically, the laminate was cut as shown in Figure 4, the rectangularity of the cross section of the conductive film was observed, and the average value of the angle corresponding to θ in Figure 4 was measured. The results are shown in Table 3. The acceptable criterion for printability was 55° or more, preferably 65° or more. In addition, 25 laminates were prepared in the same manner as above, and the short-circuit rate of the laminates was measured. Specifically, the electrical resistance between the top and middle layers and between the middle and bottom layers of the three conductive films in the laminate was measured, and this was repeated for the 25 laminates prepared. The ratio of the number of times that conduction occurred to the total number of measurements was taken as the short-circuit rate. The results are shown in Table 3. The pass criterion for the short-circuit rate was set to 5% or less, preferably 3% or less.

[0056] [Table 3]

Claims

1. A method for manufacturing a laminated inductor having a laminate in which a plurality of magnetic layers and internal electrode layers formed on the surfaces of the magnetic layers are stacked, and external electrode layers formed on end surfaces of the laminate and electrically connected to the internal electrode layers, comprising: The silver powder contains at least silver powder, a binder resin, and an organic solvent, and the specific surface area of ​​the silver powder is S ＢＥＴ (m ２ / g), and the content ratio of the binder resin to the silver powder is C ＢＮＤ (mass%), C ＢＮＤ / S ＢＥＴ The value of is 2.00 to 3.40, the copper content of the silver powder is 10 to 5000 mass ppm, and the dry film density is 7.50 g / cm ３ forming the internal electrode layers using the silver paste; A method for manufacturing a laminated inductor, comprising:

2. 2. The method for manufacturing a laminated inductor according to claim 1, further comprising laminating a magnetic layer on said magnetic layer to fill in a step caused by the thickness of said internal electrode layer.

3. 3. The method for manufacturing a laminated inductor according to claim 1, wherein the internal electrode layers are electrically connected to each other via through-hole electrodes formed to penetrate the magnetic layers in the thickness direction.

4. 3. The method for manufacturing a laminated inductor according to claim 1, wherein the laminate is formed by firing at 700° C. or less.

5. Content C of the silver powder relative to the silver paste ＡＧ 3. The method for manufacturing a laminated inductor according to claim 1, wherein the content of the SiO 2 is 80.00 to 97.00 mass %.

6. The specific surface area S of the silver powder ＢＥＴ is 0.10 to 0.30 m ２ 3. The method for manufacturing a laminated inductor according to claim 1, wherein the thickness of said laminated inductor is 1 / g.

7. When the 10% value and the 50% value in the volume-based cumulative fraction of the laser diffraction particle size distribution measurement of the silver powder are D10 and D50, respectively, D10 is 1.00 to 3.00 μm and D50 is 3.00 to 7.00 μm. The method for manufacturing a laminated inductor according to claim 1 or 2, characterized in that

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