JP2013093462A - Manufacturing method of lamination electronic component and manufacturing method of lamination unit used in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a lamination electronic component which prevents sheet attack phenomenon when the lamination electronic component is manufactured by using so-called multi-layer application technique and consequently achieves low short circuit failure rate in the electronic component obtained in the manufacturing method, and to provide a lamination unit used in the manufacturing method and a manufacturing method of the lamination unit.SOLUTION: A lamination unit has a first green sheet 10a, a first electrode pattern 12a formed on the first green sheet 10a, a second green sheet 10b formed on a surface of the first green sheet 10a where the first electrode pattern 12a is formed, and a second electrode pattern 12b formed on the second green sheet 10b. A binder resin contained in the first green sheet 10a is a first butyral resin and a binder resin contained in the second green sheet 10b is a second butyral resin that is different from the first butyral resin.

Description

  The present invention relates to a method for manufacturing a multilayer electronic component, a multilayer unit used in the method, and a method for manufacturing the same.

  As a method for manufacturing a laminated electronic component such as a capacitor, a piezoelectric element, a PTC thermistor, an NTC thermistor, or a varistor, for example, the following method is known. That is, first, a ceramic coating containing ceramic powder, an organic binder, a plasticizer, a solvent and the like is formed into a sheet shape on a flexible support (for example, a PET film) by a doctor blade method or the like to obtain a green sheet. On the green sheet, a paste containing an electrode material such as palladium, silver, or nickel is printed in a predetermined pattern to form an electrode pattern layer.

  When obtaining a laminated structure, the obtained green sheets are laminated so as to have a desired laminated structure, and a ceramic green chip is obtained through a press cutting step. The binder in the ceramic green chip thus obtained is burned out and fired at 1000 ° C. to 1400 ° C., and terminal electrodes such as silver, silver-palladium, nickel, or copper are formed on the obtained fired body. Then, a ceramic multilayer electronic component is obtained.

  In the above-described manufacturing method, for example, when manufacturing a multilayer ceramic capacitor, it is conceivable to reduce the thickness of the dielectric layers per layer and increase the number of stacks as a technique for reducing the size and increasing the capacity. However, in the method in which the green sheet is peeled off from the flexible support and laminated, particularly in the case of a thin green sheet, the green sheet cannot be peeled off well from the flexible support, resulting in a very poor lamination yield. In addition, since a thin green sheet is handled, a defective product such as a short circuit frequently occurs in the finished product.

  As a means for solving such problems, a step of forming a green sheet on a flexible support and a step of printing an electrode pattern on the green sheet include a necessary number of layers (sheet application and printing). It is conceivable to obtain a laminated unit by repeating the process only, and to stack these laminated units (hereinafter, this construction method is referred to as a multilayer coating construction method). As a result, the sheet stacking unit can be peeled from the support without damaging the sheet because the thickness of the sheet stacking unit to be peeled off from the support is increased (Patent Document 1, etc.).

  However, in this conventional manufacturing method, the process of printing an electrode pattern on the dried first green sheet and further laminating the second green sheet thereon is a wet-on-dry process. There is an inconvenience due to the system. That is, the first layer sheet is eroded by the solvent during printing of the second layer green sheet (sheet attack by the solvent). Therefore, the thickness of the green sheet in the laminated unit becomes non-uniform, the surface roughness of the sheet increases, and the short-circuit defect rate of the laminated electronic component obtained by laminating and firing the laminated unit increases.

  In particular, when the thickness of the sheet per layer is reduced, such inconvenience appears remarkably, making it difficult to manufacture a small-sized and large-capacity multilayer ceramic capacitor.

  As shown in Patent Document 2, a multilayer electronic component in which the first layer green sheet is composed of an organic paint and the second layer green sheet is composed of a water-soluble paint, thereby preventing sheet attack. The manufacturing method is known. However, when the second-layer green sheet is made of a water-soluble paint to prevent sheet attack, the strength of the laminated unit tends to be insufficient, and the laminated unit is damaged in the peeling process from the support. It is difficult to peel without.

  When a laminated unit is formed by applying a third green sheet to make up the insufficient strength of the laminated unit, there is a problem that the total number of steps increases because the number of green sheet manufacturing steps increases.

Japanese Patent No. 3190177 JP 2007-234829 A

  The present invention has been made in view of such a situation, and the object thereof is to prevent occurrence of a sheet attack phenomenon when manufacturing a multilayer electronic component by using a multilayer coating method, and a short defect rate of the resulting electronic component. The present invention is to provide a method for manufacturing a laminated electronic component with a small number of layers, a laminated unit used in the method, and a method for producing the laminated unit.

  When manufacturing multilayer electronic components using the multilayer coating method, the present inventors have produced a method of manufacturing a multilayer electronic component that does not cause a sheet attack phenomenon and has a low short-circuit defect rate of the resulting electronic component, and its As a result of earnest studies on the laminated unit used in the manufacturing method, the following invention has been completed.

That is, the laminated unit according to the present invention is
A first green sheet containing a dielectric pigment;
A first electrode pattern formed on the first green sheet;
A second green sheet formed on a surface of the first green sheet on which the first electrode pattern is formed and including a dielectric pigment;
A second electrode pattern formed on the second green sheet;
The binder resin contained in the first green sheet is a first butyral resin,
The binder resin contained in the second green sheet is a second butyral resin having a functional group ratio different from that of the first butyral resin.

In the laminated unit according to the present invention, the binder resin contained in the first green sheet and the binder resin contained in the second green sheet are butyral based resins having different butyral group amounts and / or acetyl group amounts, Sheet attack (erosion of the lower green sheet) can be suppressed. On the other hand, when the binder resin of the first green sheet and the second green sheet is a butyral resin having the same butyral group amount and acetyl group amount (conventional technology), sheet attack cannot be effectively prevented.

  In the laminated unit according to the present invention, since the sheet attack can be effectively prevented, the thickness of the green sheet is not uneven and the surface roughness of the green sheet is not increased, and the laminated unit is laminated and fired. The short-circuit defect rate of the multilayer electronic component obtained in this way is reduced.

  In the present invention, the butyral resin is used as a concept including polyvinyl butyral and polyvinyl acetal.

Preferably, in the first binder resin contained in the first green sheet and the second binder resin contained in the second green sheet, the butyral group amount in the first butyral resin constituting the first binder resin is X1. Mol%, the amount of hydroxyl groups in the first butyral resin is Y1 mol%, the amount of butyral groups in the second butyral resin constituting the second binder resin is X2 mol%, and the second butyral resin By satisfying the following formula (1) when the amount of the hydroxyl group in the Y is 2 mol%, sheet attack (erosion of the lower green sheet) can be further suppressed.
(1) 4 ≦ | (X1 + Y1) − (X2 + Y2) | ≦ 15

  In the present invention, the structure of the first butyral resin is not particularly specified. However, as described above, the sum of the butyral group amount and the hydroxyl group amount in the first butyral resin is within a predetermined amount, which is more effective. In addition, it is possible to suppress sheet attack and effectively prevent a short circuit failure.

More preferably, the amount of butyral group in the first butyral resin is X1 mol%,
When the acetyl group in the first butyral resin is Y1 mol%,
By satisfying the following formula (2), the sheet attack can be further suppressed.
(2) 58 ≦ | (X1 + Y1) | ≦ 75

  Preferably, the degree of polymerization of the first butyral resin and the second butyral resin is 800 to 3300, respectively. By using a butyral resin having a degree of polymerization in such a range, sheet attack can be suppressed particularly effectively, and short circuit defects can be effectively prevented.

  Preferably, the film thicknesses of the first green sheet and the second green sheet are each 5 μm or less, more preferably 2 μm or less.

  When the first green sheet and the second green sheet are thick, the influence of the sheet attack is small and the short-circuit defect rate is small. However, as the sheet thickness of the first green sheet and the second green sheet becomes thinner, the influence of the sheet attack becomes larger. However, according to the present invention, the occurrence of sheet attack is suppressed even when the thicknesses of the first green sheet and the second green sheet are as thin as 5 μm or less, 2 μm or less, 0.5 μm or less, and 0.15 μm or less, respectively. can do.

The laminated unit according to the present invention is
The surface roughness (arithmetic average surface roughness Ra) of the exposed portion of the first green sheet before the second green sheet is formed is defined as Ras, and the second green sheet When the surface roughness (arithmetic average surface roughness Ra) of the portion where the second green sheet is exposed after the formation of the second surface roughness Ram,
The absolute value of the difference between the second surface roughness Ram and the first surface roughness Ras | Ram−Ras | is divided by the first surface roughness Ras, and the surface roughness change rate ΔRa (= (| Ram-Ras |) × 100 / Ras) is 25% or less, preferably 14% or less, more preferably 8% or less.

  In the method for manufacturing a laminated unit according to the present invention, the binder resin contained in the first green sheet and the binder resin contained in the second green sheet are made into a butyral resin having different butyral group amounts and / or acetyl group amounts. Thus, the surface roughness change rate ΔRa can be reduced as described above. As a result, the short circuit defect rate of the multilayer electronic component obtained by laminating and firing the multilayer units is reduced.

A method for manufacturing a laminated electronic component according to the present invention includes:
Stacking the above-mentioned laminated units to obtain a ceramic laminate;
Cutting the ceramic laminate to obtain a ceramic green chip;
Firing the ceramic green chip.

FIG. 1 is a schematic cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. 2 (A) to 2 (D) are cross-sectional views showing the main part of the manufacturing process of the method for manufacturing the multilayer ceramic capacitor shown in FIG. FIG. 3 is a fragmentary cross-sectional view showing the manufacturing process subsequent to FIG.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

Overall Configuration of Multilayer Ceramic Capacitor First, the overall configuration of a multilayer ceramic capacitor will be described as an embodiment of the multilayer electronic component manufactured by the method according to the present invention.

  As shown in FIG. 1, the multilayer ceramic capacitor 2 according to this embodiment includes a capacitor body 4, a first terminal electrode 6, and a second terminal electrode 8. The capacitor body 4 includes dielectric layers 10 and internal electrode layers 12, and the internal electrode layers 12 are alternately stacked between the dielectric layers 10. One internal electrode layer 12 stacked alternately is electrically connected to the first terminal electrode 6 formed at the first end of the capacitor body 4. The other internal electrode layer 12 that is alternately stacked is electrically connected to the second terminal electrode 8 formed at the second end of the capacitor body 4.

  The material of the dielectric layer 10 is not particularly limited, and is made of a dielectric pigment such as calcium titanate, strontium titanate and / or barium titanate. The thickness of each dielectric layer 10 is not particularly limited, but is generally several μm to several hundred μm. In particular, in this embodiment, the thickness is preferably 5 μm or less, more preferably 2 μm or less, and particularly preferably 1 μm or less.

  The material of the first terminal electrode 6 and the second terminal electrode 8 is not particularly limited, but usually copper, copper alloy, nickel, nickel alloy, or the like is used. Silver or an alloy of silver and palladium can also be used. Although the thickness of the 1st terminal electrode 6 and the 2nd terminal electrode 8 is also not specifically limited, Usually, it is about 10-50 micrometers.

  The shape and size of the multilayer ceramic capacitor 2 may be appropriately determined according to the purpose and application. When the multilayer ceramic capacitor 2 has a rectangular parallelepiped shape, it is usually vertical (0.6 to 5.6 mm, preferably 0.6 to 3.2 mm) × horizontal (0.3 to 5.0 mm, preferably 0.3 to 1.6 mm) × thickness (0.1 to 1.9 mm, preferably 0.3 to 1.6 mm).

  Next, an example of a method for manufacturing the multilayer ceramic capacitor 2 according to the present embodiment will be described. First, the composition of the paint used for production will be described.

First Green Sheet Paint In the present embodiment, the first green sheet is formed from the first green sheet paint. The first green sheet paint is obtained by kneading a dielectric pigment and an organic vehicle. The organic vehicle is obtained by dissolving a binder resin in an organic solvent.

  The dielectric pigment can be appropriately selected from various compounds to be complex oxides and oxides, such as carbonates, nitrates, hydroxides, organometallic compounds, and the like, and can be used in combination. The dielectric pigment is usually used as a powder having an average particle size of 0.3 μm or less, preferably 0.2 μm or less. In order to form a very thin green sheet, it is desirable to use a powder finer than the thickness of the green sheet.

  In the present embodiment, a first butyral resin such as polyvinyl butyral is used as the binder resin used in the organic vehicle for the first green sheet paint. Moreover, it is preferable that a plasticizer is content of 10-50 mass parts with respect to 100 mass parts of binder resin. If the amount of the plasticizer is too small, the green sheet tends to become brittle. If the amount is too large, the plasticizer oozes out and it becomes difficult to handle the green sheet. Examples of the plasticizer include phthalic acid esters such as dioctyl phthalate (DOP) and benzylbutyl phthalate (BBP), adipic acid, phosphoric acid ester, and glycols.

  As an organic solvent used for the first green sheet paint, a solvent that is a good solvent for the butyral resin is preferably contained as a main component. Solvents that serve as good solvents for butyral resins include at least one alcohol solvent such as ethanol, npropanol, isopropanol, 1-butanol, 2-butanol, acetone, methyl ethyl ketone (MEK), and methyl isobutyl. The solvent contains at least one or more ketone-based solvents represented by ketone (MIBK) or cyclohexanone as a main component.

  The organic solvent used for the first green sheet paint preferably contains an aromatic solvent that is a poor solvent for the butyral resin, and preferably 40 to 60% by volume of an alcohol solvent (good). Solvent), a mixed solvent of 5 to 40% by volume of a ketone solvent (good solvent) and 20 to 30% by volume of an aromatic solvent (poor solvent) is used as an organic solvent in the first green sheet paint. It is done.

The structure of the first butyral resin in the first green sheet paint is not specified, but preferably the butyral group amount in the first butyral resin is X1 mol%, and the hydroxyl group amount in the first butyral resin is Y1 mol%. when it is desirable that you have to satisfy the following equation (2).
(2) 58 ≦ | (X1 + Y1) | ≦ 75
The degree of polymerization of the first butyral resin is 800 to 3300, preferably 1000 to 2600.

  The first butyral resin in the first green sheet paint is included in an amount of 10 to 26 parts by mass, preferably 12 to 24 parts by mass with respect to 100 parts by mass of the dielectric pigment. If the amount of this resin is too small, the increase in surface roughness due to sheet attack tends to be significant, and if it is too large, the adhesion to the carrier sheet becomes high, and the laminated unit is peeled off from the carrier sheet and laminated. At this time, a portion that cannot be peeled is generated, and a part of the laminated unit tends to be defective.

  The organic solvent is preferably 100 to 500 parts by mass with respect to 100 parts by mass of the dielectric pigment. The first green sheet paint may contain an additive selected from various dispersants, plasticizers, dielectrics, glass frit, insulators, antistatic agents, and the like as necessary. However, the total content of these additives is desirably 10 parts by mass or less with respect to 100 parts by mass of the paint.

1st electrode coating material In this embodiment, a 1st electrode pattern layer is formed from a 1st electrode coating material. In the present embodiment, an organic solvent-based paint that is incompatible with the first green sheet paint is preferably used as the first electrode paint. The first electrode paint is prepared by kneading a conductive material made of various conductive metals or alloys, or various oxides, organometallic compounds, resinates, or the like, which become the conductive material described above after firing, and an organic vehicle. .

  As the conductor material used when the first electrode paint is manufactured, Ni, Ni alloy, or a mixture thereof is used. There are no particular restrictions on the shape of such a conductor material, such as a spherical shape or a flake shape, and a mixture of these shapes may be used. The average particle diameter of the conductor material is usually 0.1 to 2 μm, preferably about 0.2 to 1 μm.

  In the present embodiment, examples of the binder resin contained in the first electrode paint include ethyl cellulose and polyvinyl butyral. Preferably, ethyl cellulose is used. The binder resin for the first electrode paint is preferably contained in the electrode paste in an amount of 4 to 10 parts by mass with respect to 100 parts by mass of the conductor material (metal powder).

  In the present embodiment, an organic solvent that is incompatible with the first green sheet paint is preferably used as the organic solvent for the first electrode paint. Examples of the solvent for the first electrode coating material include terpineol and dihydroterpineol. Preferably, dihydroterpineol is used. The solvent content for the first electrode paint is preferably about 20 to 55 mass% with respect to the entire first electrode paint.

  The first electrode paint preferably contains a plasticizer or an adhesive. As a result, the adhesiveness and tackiness between each electrode pattern layer and the green sheet are improved. As a plasticizer, the same thing as a 1st green sheet coating material can be used, The addition amount of a plasticizer is 10-300 mass parts with respect to 100 mass parts of binders in a 1st electrode coating material, More preferably 10 to 200 parts by mass. In addition, when there is too much addition amount of a plasticizer or an adhesive, there exists a tendency for the intensity | strength of a 1st electrode pattern layer to fall remarkably.

Second Green Sheet Paint In the present embodiment, the second green sheet is formed from the second green sheet paint. The second green sheet paint is obtained by kneading a dielectric pigment and an organic vehicle. The organic vehicle is obtained by dissolving a binder resin in an organic solvent.

  As the dielectric pigment, the same pigment as the first green sheet paint is used. In the present embodiment, as the binder resin used in the organic vehicle for the second green sheet paint, a second butyral resin such as polyvinyl butyral having a different sum of butyral group amount and acetyl group amount from the first butyral resin described above is used. Use.

The butyral group amount in the first butyral resin is X1 mol%, the hydroxyl group amount in the first butyral resin is Y1 mol%, the butyral group amount in the second butyral resin is X2 mol%, and A second butyral resin that satisfies the following formula (1) is selected when the amount of hydroxyl group in the second butyral resin is Y2 mol%.
(1) 4 ≦ | (X1 + Y1) − (X2 + Y2) | ≦ 15
The degree of polymerization of the second butyral resin is 800 to 3300, preferably 1000 to 2600.

  The second butyral resin in the second green sheet paint is included in an amount of 10 to 26 parts by mass, preferably 12 to 24 parts by mass, with respect to 100 parts by mass of the dielectric pigment. If the amount of the resin is too small, the increase in surface roughness due to sheet attack tends to be significant.If the amount is too large, when the laminated unit is peeled off from the carrier sheet and laminated, a part of the laminated unit is applied to the pressure plate. It adheres and the part tends to become a defect.

  As the organic solvent used for the second green sheet paint, the same solvent as the first green sheet paint is used, and the blending ratio is also the same. Other components and blending ratios other than the butyral resin contained in the second green sheet paint are also the same as in the first green sheet paint.

Second electrode paint In the present embodiment, the second electrode pattern layer is formed from the second electrode paint. In the present embodiment, an organic solvent-based paint that is incompatible with the second green sheet paint is preferably used as the second electrode paint. More preferably, an organic solvent-based paint that is incompatible with the second green sheet paint and the first green sheet paint is used as the second electrode paint. As the second electrode paint, for example, the same one as the first electrode paint may be used.

First Layer Laminating Step Next, each manufacturing step will be described. First, as shown in FIG. 2A, a first green sheet paint is applied on a carrier sheet 20 (support) to form a first green sheet 10a.

  If necessary, the formed first green sheet 10a is dried. The drying temperature of the first green sheet 10a is preferably 50 to 100 ° C., and the drying time is preferably 1 to 20 minutes. The thickness of the green sheet 10a after drying shrinks to a thickness of 5 to 25% as compared with that before drying. The thickness of the green sheet after drying is preferably 5 μm or less, more preferably 2 μm or less.

  Although it does not specifically limit as a formation method of the 1st green sheet 10a, For example, a doctor blade method etc. are mentioned.

  As the carrier sheet 20, for example, a PET film or the like is used, and a film coated with silicon or the like is preferable in order to improve peelability. Although the thickness of this carrier sheet 20 is not specifically limited, Preferably, it is 5-100 micrometers.

  Next, as shown in FIG. 2 (B), the first electrode paint is printed in a predetermined pattern on the surface of the first green sheet 10a formed on the carrier sheet 20 to form the first electrode pattern layer 12a. . In addition, before and after that, a first green sheet paint is printed on the surface of the first green sheet 10a on which the first electrode pattern layer 12a is not formed, and a first blank having substantially the same thickness as the first electrode pattern layer 12a. A pattern layer may be formed. In the illustrated embodiment, the first blank pattern layer is not formed.

  Even if the second green sheet 10b is formed on the first electrode pattern layer 12a by forming the first blank pattern layer, no step or the like is formed on the second green sheet 10b. The chip shape is also good.

  Examples of the method for forming the first electrode pattern layer 12a include the above-described printing (screen printing method, gravure printing method) thick film forming method, or thin film methods such as vapor deposition and sputtering. In the present embodiment, preferably, the printing method using the first electrode paint described above is used.

  The 1st electrode pattern layer 12a is dried as needed. The drying temperature is not particularly limited, but is preferably 70 to 120 ° C., and the drying time is preferably 5 to 15 minutes. The thickness of the first electrode pattern layer 12a after drying is not particularly limited, but is about 30 to 80% of the thickness of the first green sheet 10a after drying.

Step of Laminating Second Layer Next, as shown in FIG. 2C, a second green sheet paint is applied on the first electrode pattern layer 12a to form a second green sheet 10b. The second green sheet 10b is formed by the same method as the first green sheet 10a.

  If necessary, the formed second green sheet 10b is dried. The thickness of the second green sheet 10b after drying shrinks to a thickness of 5 to 25% as compared with that before drying. The thickness of the second green sheet 10b after drying is preferably 5 μm or less, and more preferably 2 μm or less.

  Next, as shown in FIG. 2D, a second electrode paint layer is printed on the surface of the second green sheet 10b in a predetermined pattern to form a second electrode pattern layer 12b. In addition, before and after that, a second green sheet paint is printed on the surface of the second green sheet 10b on which the second electrode pattern layer 12b is not formed, and a second blank having substantially the same thickness as the second electrode pattern layer 12b. A pattern layer may be formed. In the illustrated embodiment, the second blank pattern layer is not formed. The second electrode pattern layer 12b is formed and dried by the same method as the first electrode pattern layer 12a.

  In the present embodiment, the stacked unit U1 is obtained without forming another third green sheet on the surface of the second green sheet 10b on which the second electrode pattern layer 12b is formed.

  In the present embodiment, the first green sheet 10a and the first electrode pattern layer 12a of the first layer, and the second green sheet 10b and the second electrode pattern layer 12b of the second layer form a single stacked unit U1. Configure. A large number of stacked units U1 are stacked in the next step.

Lamination Press Process of Laminating Unit U1 Next, in the laminating press process, as shown in FIG. 3, another laminating unit in which the laminating unit U1 peeled off from the carrier sheet 20 is laminated on the carrier sheet 20 is provided. A large number of layers are stacked on U1. The carrier sheet 20 shown in FIG. 2 and the carrier sheet 20 shown in FIG. 3 may be the same or different. By repeating the stacking of the stacking unit U1, a stacked body in which a large number of green sheets and electrode pattern layers are stacked in the stacking direction Z is obtained.

  In the present embodiment, a large number of stacking units U1 are stacked in the stacking direction Z, the stacked body is heated and pressurized, and then cut into a predetermined size to form a green chip. Although not shown, an exterior green sheet on which no electrode pattern layer is formed is laminated at the lamination end in the lamination direction Z of the lamination unit U1. The heating temperature is preferably 40 to 100 ° C. The pressure during pressurization is preferably 10 to 200 MPa.

  In the present embodiment, the first electrode pattern layer 12a and the second electrode pattern layer 12b (FIG. 2) in the green chip become the internal electrode layer 12 (FIG. 1) after firing, and the first green sheet 10a and the second green sheet 10b. (FIG. 2) becomes the dielectric layer 10 (FIG. 1) after firing.

Debinding the green chip, baking treatment, and heat treatment Next, the green chip was subject to binder removal treatment, firing treatment, and heat treatment for re-oxidizing the dielectric layer is performed.

  The binder removal treatment may be performed under normal conditions. However, when a base metal such as Ni or a Ni alloy is used as the conductive material of the electrode pattern layer, it is particularly preferable to perform under the following conditions.

Temperature increase rate: 5 to 300 ° C./hour,
Holding temperature: 200-400 ° C.
Retention time: 0.5-20 hours,
Atmospheric gas: A mixed gas of humidified N ₂ and H ₂ .

The firing conditions are preferably the following conditions.
Temperature increase rate: 50 to 500 ° C./hour,
Holding temperature: 1100-1300 ° C.
Retention time: 0.5-8 hours,
Cooling rate: 50 to 500 ° C./hour,
Atmospheric gas: A mixed gas of humidified N ₂ and H ₂ or the like.

It is preferable that the oxygen partial pressure in the atmosphere at the time of baking is 10 ⁻² Pa or less, particularly 10 ⁻⁸ to 10 ⁻² Pa. If the oxygen partial pressure is too high, the electrode pattern layer tends to oxidize. If the oxygen partial pressure is too low, the conductor material of the electrode pattern layer tends to abnormally sinter and tend to break.

The heat treatment after such firing is preferably performed at a holding temperature or a maximum temperature of 1000 ° C. or higher, more preferably 1000 to 1100 ° C. The oxygen partial pressure during the heat treatment is higher than the reducing atmosphere during firing, and is preferably 10 ⁻³ Pa to 1 Pa, more preferably 10 ⁻² Pa to 1 Pa.

The conditions for the heat treatment are preferably as follows.
Retention time: 0-6 hours,
Cooling rate: 50 to 500 ° C./hour,
Atmospheric gas: humidified N ₂ gas or the like.

Note that to wet the N ₂ gas and mixed gas, etc., through a gas, for example, water heated, may be used to bubbling to device. In this case, the water temperature is preferably about 0 to 75 ° C. The binder removal treatment, firing and heat treatment may be performed continuously or independently.

  When performing these continuously, after removing the binder, the atmosphere is changed without cooling, and then the temperature is raised to the holding temperature at the time of baking to perform baking, and then cooled to reach the heat treatment holding temperature. Sometimes it is preferable to perform heat treatment by changing the atmosphere.

On the other hand, when performing these independently, at the time of firing, after raising the temperature under N ₂ gas atmosphere with N ₂ gas or wet to the holding temperature of the binder removal processing, further continuing the heating to change the atmosphere Preferably, after cooling to the holding temperature at the time of heat treatment, it is preferable to change to N ₂ gas or a humidified N ₂ gas atmosphere and continue cooling. In the heat treatment, the temperature may be changed to a holding temperature in an N ₂ gas atmosphere, and the atmosphere may be changed, or the entire process of the heat treatment may be a humidified N ₂ gas atmosphere.

The sintered body (capacitor body 4 in FIG. 1) thus obtained is subjected to end surface polishing by, for example, barrel polishing, sand blasting, etc., and terminal electrode paste is baked to form terminal electrodes (first terminal electrodes). 6, a second terminal electrode 8) is formed. The firing conditions for the terminal electrode paste are preferably, for example, about 10 minutes to 1 hour at 600 to 800 ° C. in a humidified mixed gas of N ₂ and H ₂ . Then, if necessary, a pad layer is formed on the first terminal electrode 6 and the second terminal electrode 8 by plating or the like. The terminal electrode paste may be prepared in the same manner as the first electrode paint or the second electrode paint (electrode pattern layer paste).

  The multilayer ceramic capacitor 2 of the present invention thus manufactured is mounted on a printed circuit board by soldering or the like and used for various electronic devices.

  In the manufacturing method using the laminated unit U1 of the present embodiment, the binder resin contained in the first green sheet 10a and the binder resin contained in the second green sheet 10b are different in butyral group amount and / or acetyl group amount. By using this butyral resin, so-called sheet attack (erosion of the lower green sheet) can be suppressed.

  In the laminated unit U1 according to the present embodiment, since the sheet attack can be effectively suppressed, the thickness of the green sheets 10a and 10b does not become non-uniform and the surface roughness of the green sheets 10a and 10b increases. Disappear. For example, as shown in FIG. 2B, a portion where the first green sheet 10a is exposed before the second green sheet 10b is formed and after the first electrode pattern layer 12a is formed. As shown in FIG. 2D, the second surface roughness of the portion where the surface of the second green sheet 10b after the second electrode pattern layer 12b is formed is exposed. The following relationship is found when the thickness is Ram.

  That is, the absolute value of the difference between the second surface roughness Ram and the first surface roughness Ras | Ram−Ras | is divided by the first surface roughness Ras, and the surface roughness change rate ΔRa (= (| Ram-Ras |) × 100 / Ras) is 25% or less, preferably 14% or less, and more preferably 8% or less. This indicates that the seat attack is suppressed. Conversely, when the surface roughness change rate ΔRa is large, it is considered that a large amount of sheet attack occurs.

  In the present embodiment, it is possible to reduce the short-circuit defect rate of the multilayer ceramic capacitor 2 shown in FIG. 1 obtained by laminating and firing the multilayer unit U1 in which the sheet attack is suppressed.

  Moreover, since the laminated unit U1 is thicker than the green sheet alone, it has a high strength. Therefore, the laminated unit can be easily peeled from the carrier sheet 20 without damaging the laminated unit U1. The laminated unit U1 of the present embodiment is configured as a laminated unit U1 with a two-layer green sheet structure of a first green sheet 10a and a second green sheet 10b without forming another third green sheet. Therefore, compared with the case where three or more green sheets are laminated to form a laminated unit, there is an advantage that the green sheet manufacturing process can be shortened. In addition, when calling a two-layer green sheet structure, an electrode pattern layer and a blank pattern layer are not counted in the total number.

  The present invention is not limited to the above-described embodiments, and can be variously modified within the scope of the present invention. For example, in the above-described embodiment, the second green sheet 10b is laminated on the first green sheet 10a. However, even if the first green sheet 10a is laminated on the second green sheet 10b, the sheet is similarly formed. Attack can be prevented.

  The method of the present invention is not limited to a method for manufacturing a multilayer ceramic capacitor, but can also be applied as a method for manufacturing other multilayer ceramic electronic components.

  Hereinafter, the present invention will be described based on further detailed examples, but the present invention is not limited to these examples.

Sample 1
First, a first green sheet paint was prepared. The first green sheet paint was produced as follows. That is, a mixed organic solvent of BaTiO ₃ , MgCO ₃ , MnCO ₃ , (Ba, Ca) SiO ₃ and rare earth compound having an average particle size of 120 nm, a polyvinyl butyral resin, an alcohol solvent, a ketone, and an aromatic solvent. Was prepared, and a dispersant, a plasticizer, and the like were added and mixed as necessary to form a slurry to prepare a first green sheet paint.

  As the polyvinyl butyral resin, a polyvinyl butyral resin having a degree of polymerization of 1200, a butyral group amount of 65 mol%, and an acetyl group amount of 3 mol% is used. The addition amount is 15 parts by mass with respect to 100 parts by mass of the dielectric pigment. Part by mass.

  As the alcohol solvent used for the first green sheet paint, at least one selected from ethanol, npropanol, pentanol, 1-butanol, and 2-butanol, or a mixture of two or more, an alcohol solvent in the solvent is used. The content ratio of the solvent was 55% by volume. Further, as the aromatic solvent, at least one selected from toluene, xylene, and ethylbenzene, or a mixture of two or more thereof was used, and the content of the aromatic solvent in the solvent was 20% by volume. Furthermore, as the ketones, at least one selected from acetone, cyclohexanone, MEK, MIBK, and DIBK, or a mixture of two or more thereof was used, and the content of the ketone solvent in the solvent was 25% by volume. .

Moreover, the 2nd green sheet coating material was prepared. The second green sheet paint was produced as follows. That is, a mixed organic solvent of BaTiO ₃ , MgCO ₃ , MnCO ₃ , (Ba, Ca) SiO ₃ and rare earth compound having an average particle size of 120 nm, a polyvinyl butyral resin, an alcohol solvent, a ketone, and an aromatic solvent. A second green sheet coating material was prepared by adding a dispersing agent, a plasticizer, and the like as necessary and mixing to make a slurry.

  As the polyvinyl butyral resin, a polyvinyl butyral resin having a degree of polymerization of 1200, a butyral group amount of 60 mol% and an acetyl group amount of 3 mol% is used, and the addition amount is 15 parts by mass with respect to 100 parts by mass of the dielectric pigment. Part by mass.

  As the alcohol solvent used in the second green sheet paint, at least one selected from ethanol, npropanol, pentanol, 1-butanol, and 2-butanol, or a mixture of two or more alcohol-based solvents in the solvent is used. The content ratio of the solvent was 55% by volume. Further, as the aromatic solvent, at least one selected from toluene, xylene, and ethylbenzene, or a mixture of two or more thereof was used, and the content of the aromatic solvent in the solvent was 20% by volume. Furthermore, as the ketones, at least one selected from acetone, cyclohexanone, MEK, MIBK, and DIBK, or a mixture of two or more thereof was used, and the content of the ketone solvent in the solvent was 25% by volume. .

  Moreover, the 1st electrode coating material and the 2nd electrode coating material were prepared. The first electrode paint and the second electrode paint are the same electrode paste, and are Ni pastes composed of solvent species that are incompatible with the first green sheet paint. Specifically, the Ni paste is a paste containing Ni powder having an average particle size of 0.2 μm, dihydroterpineol, ethyl cellulose resin, and DOP.

  Next, as shown in FIG. 2A, first, a first green sheet paint is applied to a thickness of 20 μm on a PET film (carrier sheet 20) by a doctor blade method, and the first green sheet 10a is applied. Formed. Next, the 1st green sheet 10a formed on the PET film was continuously sent in the drying furnace, and the solvent contained in the 1st green sheet 10a was dried. The drying temperature was 75 ° C. and the drying time was 2 minutes. The thickness of the first green sheet after drying was 2 μm.

  Next, the 1st electrode coating material was apply | coated to the surface of the 1st green sheet 10a formed on PET film by the screen printing method, and the 1st electrode pattern layer 12a was formed. Next, the first electrode pattern layer 12a formed on the first green sheet 10a was continuously fed into a drying furnace and dried at 90 ° C. for 10 minutes.

  Next, the second green sheet paint is applied to the surface of the first green sheet 10a on which the first electrode pattern layer 12a is formed to a thickness of 20 μm by the doctor blade method using the second green sheet paint described above. Then, the second green sheet 10b was formed. Next, the carrier sheet 20 on which the second green sheet 10b was formed was continuously fed into a drying furnace to dry the solvent. The drying temperature was 75 ° C. and the drying time was 2 minutes. The thickness of the second green sheet after drying was 2 μm.

  Next, the 2nd electrode coating material was apply | coated to the surface of the 2nd green sheet 10b with the screen printing method, and the 2nd electrode pattern layer 12b was formed. The second electrode pattern layer 12b formed on the second green sheet 10b was continuously fed into a drying furnace and dried at 90 ° C. for 10 minutes. After drying, a laminated unit U1 was obtained. A plurality of the laminated units U1 were produced.

  Next, after peeling the carrier sheet 20 from each lamination unit U1, as shown in FIG. 3, lamination units U1 were laminated | stacked one after another and thermocompression bonded, and the laminated body was obtained.

  Next, this laminate was cut to a predetermined size to obtain a ceramic green chip. Next, the ceramic green chip was heated to remove the binder. Next, the ceramic green chip was fired at 1000 ° C. to 1400 ° C. to obtain a sintered body. Next, in order to re-oxidize the dielectric layer in the sintered body, the sintered body was heat-treated. A terminal electrode was formed on the fired body that had been heat-treated for reoxidation to obtain a multilayer ceramic capacitor.

  The size of the multilayer ceramic capacitor was 1.6 mm in the L dimension and 0.8 mm in the W dimension. The number of stacked layers (number of electrode pattern layers) was 100 layers.

  Next, a multilayer ceramic capacitor of Sample 2 shown below was produced. Table 1 shows combinations of the binder resins of the first green sheet and the second green sheet used for the production of each sample.

Sample 2
In Sample 2, the same polyvinyl butyral resin was used for the first green sheet paint and the second green sheet paint, and the same amount of resin was added. As the polyvinyl butyral resin, a polyvinyl butyral resin having a degree of polymerization of 1200, a butyral group amount of 65 mol%, and an acetyl group amount of 3 mol% is used. Part by mass. Otherwise, a multilayer ceramic capacitor of Sample 2 was produced under the same conditions as Sample 1.

(Evaluation)
Surface roughness measurement
In the manufacturing process of the laminated unit U1 obtained in the samples 1 and 2, the surface roughness of the first green sheet 10a in the state shown in FIG. 2B: Ras and the second in the state shown in FIG. Green sheet surface roughness: Ram was measured. The surface roughness was measured using a surf coder (ET3000i manufactured by Kosaka Laboratory Ltd.). From the obtained surface roughness value, the surface roughness change rate: ΔRa was calculated from the formula [ΔRa = ( | Ram−Ras | ) × 100 / Ras]. The results are shown in Table 1. ΔRa is preferably 25% or less, more preferably 14% or less, and particularly preferably 8% or less.

The short defect rate was evaluated as a measurement and characteristic evaluation of the short defect rate. The short defect rate was evaluated by measuring the insulation resistance of 100 samples of the multilayer ceramic capacitor. Insulation resistance was measured using an insulation resistance meter (E2377A manufactured by HEWLETT PACKARD). The resistance value of each sample was measured, and a sample having a resistance value of 100 kΩ or less was determined as a short-circuit defective sample. The ratio of the sample that caused the short defect to the total measurement sample was defined as the short defect rate. The results are shown in Table 1. The short-circuit defect rate is preferably 25% or less, more preferably 12% or less, and particularly preferably 8% or less.

As shown in Table 1, the amount of butyral groups in the first butyral resin in the first green sheet paint is X1 mol%, the amount of hydroxyl groups in the first butyral resin is Y1 mol%, and the second green sheet In sample 1 satisfying the following formula (1) when the amount of butyral group in the second butyral resin in the paint is X2 mol% and the amount of hydroxyl group in the second butyral resin is Y2 mol%, The rate of change in surface roughness is 4%, and the degree of sheet attack is expected to be light. Therefore, the short defect rate is 3%, which is a good result.
(1) 4 ≦ | (X1 + Y1) − (X2 + Y2) | ≦ 15

On the contrary, in the sample 2 in which the binder resin of the first green sheet paint and the second green sheet paint is the same, since the above formula (1) is not satisfied, the surface roughness change rate ΔRa is high, and a severe sheet attack occurs. It is predicted that it has occurred. As a result, the short defect rate also shows a high value.

Samples 20-27

  In the first green sheet paint and the second green sheet paint, samples 20 to 25 of the multilayer ceramic capacitor were prepared and evaluated in the same manner as in the sample 1 except that the butyral base amount of the polyvinyl butyral resin was changed. . The results are shown in Table 2.

As shown in Table 2, the amount of butyral groups in the first butyral resin in the first green sheet paint is X1 mol%, the amount of hydroxyl groups in the first butyral resin is Y1 mol%, and the second green sheet Samples 21 and 22 satisfying the following formula (1) when the amount of butyral group in the second butyral resin in the paint is X2 mol% and the amount of hydroxyl group in the second butyral resin is Y2 mol%. 23 and 24, it was confirmed that the change rate ΔRa of the surface roughness was small and the short-circuit defect rate was low.
(1) 4 ≦ | (X1 + Y1) − (X2 + Y2) | ≦ 15

  On the other hand, in the sample 20 that does not satisfy the above formula (1), the surface roughness change rate ΔRa is large, and it is predicted that severe sheet attack occurs.

  On the other hand, in the sample 25 in which the above formula (1) is removed on the upper side, since the compatibility between the first butyral resin and the second butyral resin is low, the change rate ΔRa of the surface roughness is low, but the second slurry application Occasionally, repellency and pinholes occur frequently, and it was confirmed that a short circuit defect due to this sheet defect occurred. This is expected to be a malfunction that occurs when the total amount of butyral groups and acetyl groups of the first butyral resin and the second butyral resin are greatly different.

Samples 30-34
In the first green sheet paint and the second green sheet paint, the sum of the butyral group amount and the acetyl group amount in the second butyral resin is larger than the sum of the butyral group amount and the acetyl group amount in the first butyral resin. Samples 30 to 35 of the multilayer ceramic capacitor were produced in the same manner as Sample 1, except that the sample was changed to, and the same evaluation was performed. The results are shown in Table 3.

As shown in Table 3, the amount of butyral group in the first butyral resin in the first green sheet paint is X1 mol%, the amount of hydroxyl group in the first butyral resin is Y1 mol%, and the second green sheet (X2 + Y2) is larger than (X1 + Y1) when the amount of butyral group in the second butyral resin in the paint is X2 mol% and the amount of hydroxyl group in the second butyral resin is Y2 mol%. Even so, it was confirmed that the samples 31, 32, 33 and 34 satisfying the following formula (1) had a small surface roughness change rate ΔRa and a low short-circuit defect rate.
(1) 4 ≦ | (X1 + Y1) − (X2 + Y2) | ≦ 15

  However, in the sample 30 that does not satisfy the above formula (1), the surface roughness change rate ΔRa is large, and it is predicted that severe sheet attack occurs.

  Further, in the sample 35 in which the above formula (1) is removed on the upper side, the change rate ΔRa of the surface roughness is small because the compatibility between the first butyral resin and the second butyral resin is low as in the sample 25. It was also confirmed that repelling and pinholes occurred frequently during the application of the second slurry, and a short-circuit defect due to this sheet defect occurred.

Samples 40-44
In the first green sheet paint and the second green sheet paint, samples 40 to 44 of the multilayer ceramic capacitor were prepared in the same manner as the sample 1 except that the butyral group amount and the acetyl group amount in the butyral resin were changed. Was evaluated. The results are shown in Table 4.

In all the samples shown in Table 4, the amount of butyral group in the first butyral resin in the first green sheet paint is X1 mol%, the amount of hydroxyl group in the first butyral resin is Y1 mol%, When the amount of butyral group in the second butyral resin in the green sheet coating is X2 mol% and the amount of hydroxyl group in the second butyral resin is Y2 mol%, the following formula (1) is satisfied. Therefore, the change rate ΔRa of the surface roughness and the short-circuit defect rate are shown as a whole, but the samples 41 and 44 do not satisfy the following formula (2) at the same time. Although there is a tendency to have a high short defect rate.
(1) 4 ≦ | (X1 + Y1) − (X2 + Y2) | ≦ 15
(2) ... 58 ≦ (X1 + Y1) ≦ 75

  This is presumably because in Sample 41, the total amount of butyral groups and acetyl groups in the first polyvinyl butyral resin in the first green sheet paint was large, so that it was easy to attack the sheet. In the sample 44 in which the total amount of butyral groups and acetyl groups in one polyvinyl butyral resin is small, the surface roughness of the first green sheet itself is slightly reduced, so the short-circuit defect rate in the final product is also higher than that of other samples. Presumed to indicate a high value.

Sample 50-57
In the first green sheet paint and the second green sheet paint, the butyral group amount and the acetyl amount of the polyvinyl butyral resin are changed, and the effect of the respective values of the butyral group amount and the acetyl group amount on the sheet attack is investigated and evaluated. Samples 50 to 56 of the multilayer ceramic capacitor were produced and evaluated in the same manner. The results are shown in Table 5.

As shown in Table 5, the sheet attack does not depend on the values of the butyral group and the acetyl group, and is influenced only by the difference in the total amount of the butyral group and the acetyl group. The butyral group amount in the first butyral resin is X1 mol%, the hydroxyl group amount in the first butyral resin is Y1 mol%, and the butyral group amount in the second butyral resin in the second green sheet paint is Samples 50, 51, 52, 53, 54, 55, and 56 satisfy the following formula (1) when X2 mol% and the amount of hydroxyl group in the second butyral resin is Y2 mol%. It shows a good surface roughness change rate ΔRa and a short-circuit defect rate.
(1) 4 ≦ | (X1 + Y1) − (X2 + Y2) | ≦ 15

  In the first green sheet paint and the second green sheet paint, samples 60 to 64 of the multilayer ceramic capacitor were prepared and evaluated in the same manner as in the sample 1 except that the polymerization degree of the polyvinyl butyral resin was changed. The results are shown in Table 6.

    As shown in Table 6, in the first green sheet paint and the second green sheet paint, in samples 60, 61, 62, 64 and 65 in which the degree of polymerization of the polyvinyl butyral resin is within a desired range, the change in surface roughness It was confirmed that the rate ΔRa was small and the short-circuit defect rate was low. In addition, in the sample in which the polymerization degree of the polyvinyl butyral resin is within a desired range, it becomes possible to prevent sheet attack particularly effectively as compared with the sample 63 in which the polymerization degree of the polyvinyl butyral resin exceeds the desired range. It was confirmed that short-circuit defects can be effectively prevented.

Sample 70-78
In the first green sheet paint and the second green sheet paint, samples 70 to 78 of the multilayer ceramic capacitor were produced and evaluated in the same manner as in the sample 1 except that the amount of the polyvinyl butyral resin was changed. The results are shown in Table 7.

    As shown in Table 7, in the first green sheet paint and the second green sheet paint, in the samples 70, 72, 74 and 78 in which the resin amount of the polyvinyl butyral resin is within a predetermined range, the surface roughness change rate ΔRa Is small and the short defect rate is low.

  On the other hand, in the first green sheet paint and the second green sheet paint, in the samples 71, 75, and 77 in which the resin amount of the polyvinyl butyral resin is less than a predetermined range, the absolute amount of the resin in the green sheet is small, so the sheet attack is The result is remarkable and the short defect rate is high.

  Further, in the first green sheet paint and the second green sheet paint, in the samples 73 and 76 in which the amount of the polyvinyl butyral resin is larger than the predetermined range, there is almost no influence of the sheet attack. When peeling from the substrate, the peeling adsorption plate and the laminated unit adhered to each other, so that the lamination could not be continued, and the production of the multilayer ceramic capacitor was stopped.

Samples 80-86
Except for changing the thicknesses of the first green sheet and the second green sheet, samples 80 to 82 of the multilayer ceramic capacitor were produced in the same manner as the sample 1, and the same evaluation was performed. In the first green sheet paint and the second green sheet paint, the butyral group amount, the acetyl group amount, and the resin amount of the polyvinyl butyral resin are changed so that the thicknesses of the first green sheet and the second green sheet are 0.5 μm. Except for the above, samples 83 to 86 of multilayer ceramic capacitors were produced in the same manner as Sample 1, and the same evaluation was performed. The results are shown in the table.

  As shown in Table 8, it is confirmed that the samples 80 to 82 in which the thicknesses of the first green sheet and the second green sheet are within a desired range have a small surface roughness change rate ΔRa and a low short-circuit defect rate. It was done. Further, in the first green sheet paint and the second green sheet paint, the thicknesses of the first green sheet and the second green sheet can be changed even when the butyral group amount, the acetyl amount, and the resin amount of the polyvinyl butyral resin are changed within predetermined ranges, respectively. It was confirmed that samples 63 to 66 having a thickness within a desired range have a small surface roughness change rate ΔRa and a low short-circuit defect rate.

2 ... Multilayer ceramic capacitor 4 ... Capacitor body 6 ... First terminal electrode 8 ... Second terminal electrode 10 ... Dielectric layer 10a ... First green sheet 10b ... Second green sheet 12 ... Internal electrode layer 12a ... First electrode pattern Layer 12b ... Second electrode pattern layer 20 ... Carrier sheet (support)
U1, U2 ... Stacked unit

Claims (6)

A first green sheet containing a dielectric pigment;
A first electrode pattern formed on the first green sheet;
A second green sheet formed on a surface of the first green sheet on which the first electrode pattern is formed and including a dielectric pigment;
A laminated unit having a second electrode pattern formed on the second green sheet,
The binder resin contained in the first green sheet is a first butyral resin,
A laminated unit in which the binder resin contained in the second green sheet is a second butyral resin having a functional group ratio different from that of the first butyral resin, and the laminated unit is cut to obtain a ceramic green Obtaining a chip;
Firing the ceramic green chip;
A method of manufacturing a laminated electronic component having The content of the first butyral resin contained in the first green sheet and the content of the second butyral resin contained in the second green sheet are each 100 parts by mass of the dielectric pigment. , 10 to 26 parts by mass,
The butyral group amount in the first butyral resin is X1 mol%,
The amount of hydroxyl group in the first butyral resin is Y1 mol%,
The butyral group content in the second butyral resin is X2 mol%,
When the amount of hydroxyl group in the second butyral resin is Y2 mol%,
Stacking laminated units characterized by satisfying the following formula (1) to obtain a ceramic laminate;
Cutting the ceramic laminate to obtain a ceramic green chip;
And a step of firing the ceramic green chip.
(1) 4 ≦ | (X1 + Y1) − (X2 + Y2) | ≦ 15 The butyral group amount in the first butyral resin is X1 mol%,
When the acetyl group in the first butyral resin is Y1 mol%,
The process of obtaining the ceramic laminate by stacking the laminate units according to claim 1, wherein the following formula (2) is satisfied:
Cutting the ceramic laminate to obtain a ceramic green chip;
And a step of firing the ceramic green chip.
(2) 58 ≦ | (X1 + Y1) | ≦ 75 The degree of polymerization of the first butyral resin and the second butyral resin is 800 to 3300, respectively, and stacking the multilayer units according to claim 1 or 2 to obtain a ceramic laminate,
Cutting the ceramic laminate to obtain a ceramic green chip;
And a step of firing the ceramic green chip. The film thicknesses of the first green sheet and the second green sheet are each 5 μm or less, and the step of stacking the multilayer units according to claim 1 to obtain a ceramic laminate,
Cutting the ceramic laminate to obtain a ceramic green chip;
And a step of firing the ceramic green chip. A method for producing the laminated unit according to claim 1,
Ras is the first surface roughness of the exposed portion of the first green sheet before the second green sheet is formed, and the second green sheet is exposed after the second green sheet is formed. If the second surface roughness of the part that is doing is Ram,
The surface roughness change rate ΔRa expressed as a percentage by dividing the absolute value of the difference between the second surface roughness Ram and the first surface roughness Ras by the first surface roughness Ras is 25% or less. Stacking laminated units characterized by obtaining a ceramic laminate,
Cutting the ceramic laminate to obtain a ceramic green chip;
And a step of firing the ceramic green chip.

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