JP5998785B2 - Laminated electronic components - Google Patents

Description

  The present invention relates to a multilayer electronic component such as a multilayer ceramic capacitor.

  In an electronic component such as a multilayer ceramic capacitor, a dielectric layer and an internal electrode layer are being made thinner in order to reduce the size and increase the capacity. When the dielectric layer and the internal electrode layer are made thinner, it becomes difficult to connect the internal electrode layer and the terminal electrode.

  When the connection between the internal electrode layer and the terminal electrode is incomplete, there is a problem that the obtained capacitance is reduced. In view of this, several methods have been proposed for improving the connectivity of the internal electrode layer connected to the terminal electrode with the terminal electrode.

  For example, we propose a technology that improves the connection between the lead part and the terminal electrode by ensuring the exposure of the lead part of the internal electrode layer on the side end face of the element body by wet barrel polishing of the side end face of the element body after firing Has been. A technique for extending the lead portion of the internal electrode layer using a metal diffusion coefficient (using a chemical phenomenon) is also known.

  However, it is very difficult to physically and reliably connect the lead portion of the internal electrode layer and the terminal electrode, and a method for sufficiently improving the connectivity has not yet been established. In Patent Document 1 below, a method of forming a glass extending portion in order to increase the strength of the lead portion of the internal electrode layer is disclosed. However, since the method of adjusting the amount of added glass is used, the glass diffuses to the opposing region of the internal electrode layer (effective region of the capacitor), which may adversely affect the electrical characteristics.

  Patent Document 2 below discloses a structure in which the side end surface of the element main body is physically cut to form a concave portion as a connection portion to improve plating. However, even in this structure, it is difficult to improve the connection between the lead portion of the internal electrode layer and the terminal electrode, and it has been desired to further improve the electrical characteristics such as capacitance.

  In Patent Document 3 below, an electronic component for forming a through-hole electrode is disclosed. However, with the miniaturization of electronic components, it is difficult to form through holes with high precision in the element body, and mass production is difficult.

  In addition, the following Patent Document 4 proposes that a large amount of metal constituting the internal electrode is deposited at the joint between the internal electrode and the terminal electrode to improve the sealing property against moisture. However, in the invention shown in Patent Document 4, it is preferable that a gap is not formed at the joint between the internal electrode and the terminal electrode, which takes into account improvement of thermal shock resistance and prevention of cracks in the element body. It wasn't.

JP 2009-170706 A JP 2010-21523 A Japanese Patent Application Laid-Open No. 07-201634 JP 2004-79618 A

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a laminate that is excellent in contact characteristics between internal electrodes and terminal electrodes, has excellent thermal shock resistance, and can reduce crack defects in the element body. To provide electronic components.

In order to achieve the above object, the multilayer electronic component according to the present invention is
An element body in which a plurality of internal electrode layers laminated so as to face each other through a ceramic layer are formed;
A laminated electronic component having a terminal electrode provided on a side end surface of the element body,
A gap of a predetermined interval is formed between the terminal electrode and the side end surface,
A lead portion protruding from the side end surface through the gap and connected to the terminal electrode is formed integrally with the internal electrode layer at an end portion in the side end surface direction of the internal electrode layer,
A tip portion of the protruding portion protruding from the side end surface of the lead portion is embedded in the terminal electrode, and a thick portion thicker than the thickness of the lead portion is formed,
The internal electrode main component of the metal component constituting the internal electrode layer is different from the terminal electrode main component of the terminal electrode to which the lead portion of the internal electrode is connected,
The protruding portion and the thick portion are made of an alloy of the internal electrode main component and the terminal electrode main component. Specifically, the internal electrode main component is nickel and the terminal electrode main component is copper.

  In the multilayer electronic component of the present invention, since a gap with a predetermined interval is formed between the terminal electrode and the side end surface, the thermal shock resistance is excellent. In addition, since the tip portion of the protruding portion protruding from the side end surface of the element body in the lead portion is embedded in the terminal electrode and has a thicker portion thicker than the thickness of the lead portion, the terminal electrode and Excellent contact characteristics with internal electrodes.

  Moreover, in the multilayer electronic component according to the present invention, the protruding portion and the thick portion are made of an alloy of the internal electrode main component and the terminal electrode main component, and the terminal electrode main component is located inside the element body. The rate of diffusion to the lead is small. Therefore, the occurrence of cracks in the element body due to an increase in the thickness of the lead portion located inside the element body can be prevented.

FIG. 1 is a schematic cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a main part of the capacitor shown in FIG. 3A to 3C are schematic cross-sectional views showing an example of a method for manufacturing the capacitor shown in FIG. FIG. 4 is a schematic cross-sectional view showing a step subsequent to FIG. FIG. 5A to FIG. 5C are schematic cross-sectional views showing a continuation process of FIG.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
As shown in FIG. 1, the multilayer ceramic capacitor 2 according to the present embodiment includes an element body 4, a first terminal electrode 6, and a second terminal electrode 8. The element body 4 has a first internal electrode layer 12 and a second internal electrode layer 13, and these internal electrode layers 12 and 13 are alternately laminated so as to sandwich the inner dielectric layer 10.

  The element body 4 has outer dielectric layers 14 on both end faces in the stacking direction (Z-axis direction). One of the first internal electrode layers 12 stacked alternately is electrically connected to the first terminal electrode 6 formed on the first side end face 5 of the element body 4. The other second internal electrode layer 13 stacked alternately is electrically connected to the second terminal electrode 8 formed on the second side end face 7 of the element body 4.

  The first side end surface 5 and the second side end surface 7 of the element body 4 face each other along the X-axis direction. 1 to 4, the X axis, the Y axis, and the Z axis are perpendicular to each other, the Z axis coincides with the stacking direction of the dielectric layer 10, and the X axis indicates the extraction direction of the internal electrode layers 12 and 13. Matches. The element body 4 has a predetermined width also in the Y-axis direction.

  The material of the inner dielectric layer 10 and the outer dielectric layer 14 is not particularly limited, and is made of a dielectric material such as calcium titanate, strontium titanate and / or barium titanate. The thickness of each inner dielectric layer 10, 11 is not particularly limited, but is generally 0.2 μm to several tens of μm. Further, the thickness of the outer layer portion composed of the outer dielectric layer 14 is not particularly limited, but is preferably in the range of 10 to 200 μm.

  The material of the first internal electrode layer 12 and the second internal electrode layer 13 is not particularly limited, and examples thereof include Ni, Pd, Ag, and Cu. Ni or Ni alloy is preferable.

  The material of the terminal electrodes 6 and 8 is not particularly limited, but usually at least one of Ni, Pd, Ag, Cu, or an alloy thereof can be used. As the terminal electrodes 6 and 8, Cu, Cu alloy, Ni, Ni alloy or the like, Ag, Ag—Pd alloy or the like is usually used. The thickness t0 (see FIG. 2) of the terminal electrodes 6 and 8 is not particularly limited, but is usually about 2 to 50 μm.

  In the present embodiment, the metal main component of the first internal electrode layer 12 and the second internal electrode layer 13 and the metal main component of the terminal electrodes 6 and 8 are preferably different, the internal electrode main component is nickel, The terminal electrode main component is preferably copper. However, other combinations may be used. For example, the internal electrode main component is an Ag—Pd alloy and the terminal electrode main component is a combination of Cu.

  The terminal electrodes 6 and 8 may be composed of a single layer, but may be composed of a plurality of layers. In any case, the portions of the terminal electrodes 6 and 8 that are in direct contact with the side end face 5 or 7 of the element body 4 are preferably composed mainly of a metal different from the main components of the internal electrode layers 12 and 13. For example, when the main component of the internal electrode layers 12 and 13 is Ni, the terminal electrodes 6 and 8 are preferably made of a metal containing Cu as a main component. This is because it is easy to form the protruding portion 26 and the thick portion 28 by utilizing metal diffusion by the Kirkendall effect, as will be described later.

  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 about vertical (0.2 to 5.7 mm) × horizontal (0.1 to 5.0 mm) × thickness (0.1 to 3.2 mm).

  In the present embodiment, a first lead portion 22 exposed at the first side end surface 5 and connected to the first terminal electrode 6 is provided at the end of the first internal electrode layer 12 in the first side end surface 5 direction. It is formed in the same plane as the electrode layer 12. A second lead portion 23 exposed to the second side end surface 7 and connected to the second terminal electrode 8 is provided at the end of the second internal electrode layer 13 in the second side end surface 7 direction. Are formed in the same plane.

  A first intermediate insulating region 20 is formed between the end of the first internal electrode layer 12 in the direction of the second side end face 7 and the second terminal electrode 8. The first intermediate insulating region 20 is formed between the second lead portions 23 adjacent in the Z-axis direction, and is connected to the inner dielectric layer 10. A second intermediate insulating region 21 is formed between the end of the second internal electrode layer 23 in the direction of the first side end face 5 and the first terminal electrode 6.

  As shown in FIG. 2, in the present embodiment, a gap 24 having a predetermined interval is formed between the second side end surface 7 of the element body 4 and the terminal electrode 8. The width Δt of the gap 24 (width gap in the X-axis direction) is preferably 0.5 to 2.0 μm. If the width Δt of the gap 24 is too small, the effect of improving the thermal shock characteristics is small. If the width Δt is too large, the actual thickness is reduced by the gap when the thickness of the terminal electrode is constant. Since moisture easily enters, moisture resistance tends to deteriorate and resistance deterioration tends to occur.

  Further, in the present embodiment, a lead portion 23 protruding from the side end surface 7 through the gap 24 and connected to the terminal electrode 8 is formed integrally with the internal electrode layer 13 at the end portion in the side end surface direction of the internal electrode layer 13. . Further, the leading end portion of the projecting portion 26 projecting from the side end surface 7 in the lead portion 23 is embedded in the terminal electrode 8 and has a thickness t2 larger than the thickness t1 of the lead portion 23 located in the gap 24. A thick portion 28 is formed.

  The ratio t2 / t1 is preferably 1.3 to 2.0. If this ratio is too small, the contact characteristics between the internal electrode and the terminal electrode tend to deteriorate, and if it is too large, the amount of movement of the electrode component of the internal electrode from the inside of the element body to the junction with the terminal electrode is large. If it becomes too much, there is a tendency that structural defects such as discontinuity occur inside the element body and the coverage is lowered tend to occur.

  The thick portions 28 do not necessarily have to be formed in all the lead portions 23, but preferably, the thick portions 28 are formed in 90% or more of the lead portions 23 with respect to the total number of the lead portions 23. preferable.

  In the present embodiment, the protruding portion 26 and the thick portion 28 are made of an alloy of a metal main component constituting the internal electrode 13 and a metal main component of the terminal electrode 8 to which the lead portion 23 is connected. Specifically, the metal main component of the internal electrode is nickel, and the main component of the terminal electrode is copper.

  In the above description, the description has been given of the gap between the second side end face 7 of the element body 4 and the terminal electrode 8, but a similar gap 24 is also provided between the first side end face 5 of the element body 4 and the terminal electrode 6. Are formed, and the same protrusion 26 and thick part 28 are formed. The same applies to the following description.

  In the multilayer ceramic capacitor 2 of the present embodiment, since the gap 24 having a predetermined interval is formed between the terminal electrodes 6 and 8 and the side end surfaces 5 and 7, the thermal shock resistance is excellent. In addition, the lead portions 22 and 23 are embedded in the terminal electrodes 6 and 8 at the tip ends of the protruding portions 26 protruding from the side end surfaces 5 and 7 of the element body 4, and are larger than the thickness of the lead portions 22 and 23. Since the thick and thick portion 28 is formed, the contact characteristics between the terminal electrodes 6 and 8 and the internal electrodes 12 and 13 are excellent.

  Moreover, in the multilayer ceramic capacitor 2 according to the present embodiment, the protruding portion 26 and the thick portion 28 are made of an alloy of the internal electrode main component and the terminal electrode main component, and the terminal electrode main component is the element main body 4. The ratio of diffusion to the lead portions 22 and 23 located inside (inside the intermediate insulating regions 20 and 21) is small. Therefore, the occurrence of cracks in the element body 4 due to an increase in the thickness of the lead portions 22 and 23 located inside the element body 4 can be prevented.

  Next, the manufacturing method of the multilayer ceramic capacitor 2 as one embodiment of the present invention will be described.

  First, as shown in FIG. 3A, a green sheet 10a is formed on a support sheet 30 made of a PET film or the like by a doctor blade method or the like. The green sheet 10a is a portion that becomes the inner dielectric layer 10 shown in FIG. 1 after firing.

  Next, as shown in FIG. 3B, on the green sheet 10a, the internal electrode pattern layer 12a that becomes the first internal electrode layer 12 or the second internal electrode layer 13 shown in FIG. Alternatively, 13a is formed.

  Next, as shown in FIG. 3C, a blank pattern layer 10b is formed in the gap between the internal electrode pattern layers 12a or 13a by a screen printing method or the like. The blank pattern layer 10b is a portion that becomes a part of the intermediate insulating region 20 or 21 shown in FIG. The blank pattern layer 10b may have the same paint composition as the green sheet 10a or a different composition.

  Next, the unit U1 composed of the green sheet 10a, the electrode pattern layer 12a (or 13a), and the blank pattern layer 10b shown in FIG. 3C is peeled off from the support sheet 30, and as shown in FIG. The green laminate 4a is formed by sequentially laminating on the exterior green sheet 15 previously laminated on the mold 40. When the units U1 are stacked, the electrode pattern layers 12a and 13a are stacked alternately. After a predetermined number of units U1 are stacked, a plurality of exterior green sheets 15 are stacked thereon. The exterior green sheet 15 is a portion that becomes the outer dielectric layer 14 shown in FIG. 1 after firing.

  The dielectric paste for forming the green sheets 10a and 11a is usually composed of an organic solvent-based paste or an aqueous paste obtained by kneading ceramic powder and an organic vehicle. In the present embodiment, these pastes are organic solvent-based pastes.

  The organic vehicle is obtained by dissolving a binder in an organic solvent. The binder used for the organic vehicle is not particularly limited, and may be appropriately selected from usual various binders such as ethyl cellulose and polyvinyl butyral.

  The internal electrode paste for forming the internal electrode patterns 12a, 13a is composed of various conductive metals and alloys, or various oxides, organometallic compounds, resinates, etc. that become conductive materials after firing, and the above-mentioned organic materials. Prepare by kneading with vehicle. The internal electrode paste may contain a ceramic powder as a co-material as necessary. The common material has an effect of suppressing the sintering of the conductive powder in the firing process.

  In FIG. 4, the number of the internal electrode layers 12 a and 13 a is reduced for ease of illustration, but the number of layers can be freely set from several to several hundred. In the green laminate 4a, the first internal electrode pattern 12a and the second internal electrode pattern 13a are linear repetitive patterns that are shifted by a half pattern along the X axis of the patterns 12a and 13a. Further, when viewed along the Y-axis of the patterns 12a and 13a, the first internal electrode pattern 12a and the second internal electrode pattern 13a are separated linear patterns having the same pitch length.

  The green laminate 4a is cut along the planned cutting line 50. In FIG. 4, only the planned cutting line 50 in the X-axis direction is shown, but the planned cutting line is also formed in the Y-axis direction, and cut along these planned cutting lines to obtain a green chip before firing. It is done. An example of the side end face of the green chip before firing is shown in FIG.

  Next, a binder removal process and a firing process are performed on these green chips. Various conditions for the binder removal process and the baking process are not particularly limited. However, as shown in FIG. 5B, after baking, the lead part 23 of the internal electrode protrudes from the side end face 7 of the element body 4, and the thick part 28. Is performed under such conditions that can be formed. As such a binder removal condition, it is preferable to lower the temperature as compared with a normal binder removal condition. Further, as firing conditions, it is preferable to increase the oxygen partial pressure in order to weaken the reducing atmosphere as compared with normal firing conditions. Furthermore, the chip size of the element body 4 is also affected, and the chip size is vertical (2.0 to 5.7 mm) × horizontal (1.2 to 5.0 mm) × thickness (1.2 to 3.2 mm). It is also preferable.

  Thereafter, the terminal electrode paste for forming the terminal electrodes 6 and 8 is applied to the both side end faces 5 and 7 of the element body 4 without polishing the both end faces 5 and 7 of the element body 4 after firing shown in FIG. To do. Thereafter, after the binder removal treatment, the terminal electrode paste is baked.

  The binder removal and terminal electrode paste baking conditions are set so that the Kirkendall effect occurs effectively and the gap 24 and the protrusion 26 described above are easily formed as shown in FIGS. The As a condition for such a binder removal treatment, for example, the heat treatment temperature of the binder removal treatment is preferably performed in the range of 470 to 550 ° C. When the binder removal temperature is low, the resin is not sufficiently decomposed, and when the binder removal temperature is high, the resin is decomposed and the Cu powder is sintered at the same time, which may cause the occurrence of terminal cracking or the like. When the resin is sufficiently decomposed from the terminal electrode paste, the adhesiveness with the end face of the element body can be lowered, so that it becomes easy to form the gap (gap 24).

  The terminal electrode paste preferably has a Cu powder particle size of 1 to 5 μm, the solvent is terpineol, toluene, acetone, methyl ethyl ketone, and the binder resin is preferably ethyl cellulose or butyral. Moreover, the ratio of the binder resin in the terminal electrode paste is preferably 2 to 10% by weight, more preferably 4 to 6% by weight.

Moreover, although the specific conditions at the time of a baking process change also with the metal contained in a terminal electrode paste, for example, baking temperature becomes like this. Preferably, it is 700-800 degreeC, More preferably, it is 725-800 degreeC, The atmosphere gas is preferably a mixed gas of N ₂ and H ₂ or only N ₂ , and the concentration of H ₂ is preferably 1.0 to 0%, which is lower than the conventional one.

  In the present embodiment, after the terminal electrode paste is baked, the plating process is performed and the plating film is laminated, so that the first terminal electrode 6 and the second terminal electrode 8 shown in FIG. 1 are formed. The multilayer ceramic capacitor 2 of the present embodiment manufactured as described above is mounted on a printed circuit board by soldering or the like, and used for various electronic devices.

  In the present embodiment, when the electrode paste constituting the base electrode of the terminal electrodes 6 and 8 is baked, the protruding portion 26 is formed, and the connection interface between the terminal electrodes 6 and 8 and the internal electrode layers 12 and 13 is formed by the Kirkendall effect. The metal diffusion occurs toward the lead portions 22 and 23 of the internal electrode layer. However, since the protruding portion 26 and the thick portion 28 are formed, the proportion of the terminal electrode main component diffused to the lead portions 22 and 23 located inside the element body 4 (inside the intermediate insulating regions 20 and 21) is high. Few. Generation of cracks in the element body 4 due to an increase in the thickness of the lead portions 22 and 23 located inside the element body 4 can be prevented.

  Further, in the multilayer ceramic capacitor 2 of the present embodiment, the gap 24 having a predetermined interval is formed between the terminal electrodes 6 and 8 and the side end surfaces 5 and 7, so that the thermal shock characteristics are excellent. In addition, the lead portions 22 and 23 are embedded in the terminal electrodes 6 and 8 at the tip ends of the protruding portions 26 protruding from the side end surfaces 5 and 7 of the element body 4, and are larger than the thickness of the lead portions 22 and 23. Since the thick and thick portion 28 is formed, the contact characteristics between the terminal electrodes 6 and 8 and the internal electrodes 12 and 13 are excellent.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention. For example, the method for forming the protruding portion 26 protruding in the gap 24 and the thick portion 28 positioned inside the terminal electrode on the lead portions 22 and 23 of the internal electrode is not limited to the above-described embodiment.

  The multilayer electronic component according to the present invention is not limited to the multilayer ceramic capacitor described above, and may be a multilayer thermistor, multilayer inductor, multilayer chip varistor, or the like. That is, depending on the type of the laminated electronic component, the element body 4 may be composed of a ceramic layer other than the dielectric layer.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.

Examples 1 to 4 and Comparative Example 1
Inner and outer green sheet paste, blank pattern layer paste First, BaTiO ₃ system powder as ceramic powder: 100 parts by weight, polyvinyl butyral (PVB) as binder: 6 parts by weight, ethanol as solvent: 19 parts by weight, solvent N-propanol: 19 parts by weight, xylene: 14 parts by weight, mineral spirit: 7 parts by weight, dioctyl phthalate (DOP): 3 parts by weight as plasticizer A sheet paste was obtained.

  The molecular weight of polyvinyl butyral used for the inner green sheet paste was 92,000.

Next, BaTiO ₃ system powder as ceramic powder: 100 parts by weight, polyvinyl butyral (PVB): 6 parts by weight as binder, ethanol: 15 parts by weight as solvent, n-propanol: 15 parts by weight as solvent, and as solvent 7 parts by weight of xylene, 11 parts by weight of toluene as a solvent, 10 parts by weight of mineral spirit as a solvent, and 3 parts by weight of dioctyl phthalate (DOP) as a plasticizer were slurried with a ball mill to prepare a paste for an outer green sheet. Obtained. As the diameter of the BaTiO ₃ system powder, a diameter observed by SEM and having a D50 diameter of 0.5 μm was used.

  The molecular weight of polyvinyl butyral used for the outer green sheet paste was 92,000.

Next, an organic vehicle was prepared by stirring and dissolving 4 parts by weight of ethyl cellulose resin having a molecular weight of 130,000 and 4 parts by weight of ethyl cellulose resin having a molecular weight of 230,000 in 92 parts by weight of isobornyl acetate at a temperature of 70 ° C. . That is, an 8% by weight isobornyl acetate solution of ethyl cellulose resin was used as the organic vehicle. Next, BaTiO ₃ powder: 95.70 parts by weight, organic vehicle: 104.36 parts by weight, polyethylene glycol-based dispersant: 1.0 part by weight, dioctyl phthalate (plasticizer): 2.61 parts by weight, isobornyl acetate : 19.60 parts by weight, acetone 57.20 parts by weight, and imidazoline surfactant (charging aid): 0.4 parts by weight were mixed using a ball mill to form a paste. As the diameter of the BaTiO ₃ system powder, a diameter observed by SEM and having a D50 diameter of 0.7 μm was used. Next, the obtained paste was removed by evaporating acetone by using an agitator equipped with an evaporator and a heating mechanism to obtain a blank pattern paste.

Preparation of paste for internal electrode pattern layer Ni particles: 44.6 parts by weight, terpineol: 52 parts by weight, ethyl cellulose: 3 parts by weight, benzotriazole: 0.4 parts by weight are kneaded by three rolls, An internal electrode pattern layer paste was prepared by slurrying.

Formation of Green Chip Next, the multilayer ceramic chip capacitor 2 shown in FIG. 1 was manufactured using the green sheet paste prepared above and the internal electrode pattern layer paste as follows.

  First, an inner green sheet paste was applied to a predetermined thickness on a PET film as a support by a doctor blade method and dried to prepare a green sheet.

  Next, the internal electrode pattern layer 12a or 13a (see FIG. 3B) having a predetermined pattern was formed on the obtained inner green sheet using the internal electrode paste. Further, a blank pattern layer 10b was formed in the pattern gap of the internal electrode pattern layer 12a or 13a.

  On the other hand, separately from the above, an outer green sheet was formed on the PET film using the outer green sheet paste, and then the sheet was peeled from the PET film.

  Next, a plurality of inner green sheets 10a on which the internal electrode pattern layer 12a or 13a was formed were stacked, and a plurality of outer green sheets 14a were stacked to obtain a green stacked body 4a shown in FIG. Then, the obtained green laminate 4a was cut into a predetermined size to obtain a green chip.

Firing or the like of the green chip Next, the obtained green chip was subject to binder removal treatment, baked and annealed under the following conditions to obtain a sintered body.

  The binder removal was performed under the conditions of a temperature rising rate: 200 ° C./hour, a holding temperature: 250 ° C., a holding time: 8 hours, and a processing atmosphere: in air.

Firing is performed at a heating rate of 200 ° C./hour, a holding temperature of 1100 to 1380 ° C., a holding time of 2 hours, a cooling rate of 100 ° C./hour, a processing atmosphere: a reducing atmosphere (oxygen partial pressure: 5 × 10 ⁻⁵ Pa. And a mixed gas of N ₂ and H ₂ was adjusted by passing water vapor).

The annealing was performed under the conditions of holding temperature: 1050 ° C., holding time: 2 hours, temperature drop rate: 100 ° C./hour, treatment atmosphere: humidified N ₂ gas atmosphere. A wetter was used to wet the gas during firing and annealing, and the water temperature was set to 35 ° C.

  A terminal electrode paste (including Cu as a main component of a conductive material) is applied to both side end faces of the element body 4 without polishing the side end faces 5 and 7 of the obtained sintered body (element body 4). After the binder was removed under the removal conditions (470 to 550 ° C.) so that the resin in the paste was sufficiently removed, a baking process was performed under the temperature conditions shown in Table 1 to form terminal electrodes. A sample of the multilayer ceramic capacitor shown in FIG. As the terminal electrode paste, a Cu powder particle size of 2 μm, terpineol as a solvent, ethyl cellulose as a resin, and a resin ratio of 5% in the terminal electrode paste were used.

The firing conditions of the terminal electrode paste were, for example, about 10 to 20 minutes at 700 to 800 ° C. in a humidified mixed gas of N ₂ and H ₂ . The size of the obtained sintered body is 3.2 mm long × 1.6 mm wide × 1.6 mm high, and the thickness of the inner dielectric layer 10 sandwiched between the pair of internal electrode layers is about 1.7 μm. The thickness t1 of the electrode layer 12 was 1.0 μm.

  When a sample of the obtained multilayer ceramic capacitor 2 was cut and confirmed with a micrograph, as shown in FIG. 2, there was a lead portion between the side end surfaces 5 and 7 of the element body 4 and the terminal electrodes 6 and 8. It was confirmed that a gap 24 was formed at a position where 22 and 23 were formed, and a protruding portion 26 and a thick portion 28 were formed on the lead portions 22 and 23. Further, as shown in Table 1, it was confirmed that the gap Δt changes according to the terminal baking temperature.

  In addition, the gap Δt shown in Table 1 was obtained by cutting the cross section and measuring the thickness of the void with a metal microscope. The measurement points were 10 points, and the average value was Δt. Further, the thermal shock resistance of the obtained capacitor sample was measured. The thermal shock resistance was measured as follows.

Thermal shock resistance, that is, the obtained capacitor sample was mounted on a circuit board, and one heat treatment cycle including the following steps (i) to (iv) was repeated 1000 times. One heat treatment cycle includes the following steps (i) to (iv).
(I) a step of holding a sample of a circuit board and a capacitor for 30 minutes under a temperature condition where the temperature of the chip body is −55 ° C .;
(Ii) raising the temperature of the chip body to 125 ° C. within 10% of the holding time (3 minutes);
(Iii) a step of holding for 30 minutes under a temperature condition where the temperature of the chip body is 125 ° C .;
(Iv) The step of lowering the temperature of the chip body to −55 ° C. within 10% of the holding time (3 minutes).

  Here, the circuit board was a glass epoxy (epoxy resin having a glass fiber sheet as a core) substrate. The thermal shock resistance was evaluated from the presence or absence of cracks after the above thermal shock test. Here, from the evaluation result of the presence or absence of cracks in 1000 samples, the case where even one crack occurred was rated as x, and the case where no crack was observed was marked as ◯.

Moisture resistance load test 100 samples were subjected to an accelerated moisture resistance load test in which voltage was applied in an atmosphere of 85 ° C. and 85% humidity. After the implementation, the case where even one piece in which the insulation resistance decreased by two digits relative to the initial value occurred was regarded as defective (x). The results are shown in Table 1.

Examples 21 to 22 and Comparative Example 2
Except that the firing temperature and atmosphere of the element body 4 were changed, a capacitor sample was prepared in the same manner as in Example 2, the thickness ratio was measured, and the contactability and crack resistance were examined. The measurement of the thickness ratio was performed in the same manner as the measurement of the gap Δt. Regarding Comparative Example 2, firing conditions were employed in which the thick portion 28 was not formed at the stage after firing of the element body shown in FIG.

Contactability Contactability is judged as defective (x) when the capacitance drops by 5% or more even if one out of 1000 capacitors is the target capacitance of the capacitor sample. Those not present were determined to be not defective (◯).

Crack resistance Crack resistance is achieved by placing a capacitor sample in a pressure cooker tank, performing an accelerated moisture resistance load test (PCBT test) in which voltage is applied in an atmosphere of 121 ° C. and 95% humidity, and charging N = 1000. If even one crack occurred, it was judged as defective (x), and the other one was judged as not defective (O). The capacitance was measured using an LCR meter.

Further , in the present invention, in the present invention, on the surface obtained by cutting the element body along a plane parallel to the stacking direction, the line length when the electrode layer is assumed to have no electrode absent portion (the line length on which the electrode layer is to be formed) )) Is defined as 100%, and the ratio of the line length where the electrode layer is actually formed (the line length actually covering the dielectric layer) is defined as the coverage.
If the coverage is too small, the characteristics of the dielectric layer existing immediately below the uncovered region cannot be exhibited, and the effective capacity (relative dielectric constant) of the dielectric layer tends to decrease. When the coverage was 80% or more, it was determined as not defective (O), and when it was less than 80%, it was determined as defective (X). The results are shown in Table 2.

2 ... multilayer ceramic capacitor 4 ... element body 4a ... green laminated body 5 ... first side end face 7 ... second side end face 6 ... first terminal electrode 8 ... second terminal electrode 10 ... inner dielectric layer 10a ... green sheet 10b ... Blank pattern layer 12 ... First internal electrode layer 12a ... Internal electrode pattern 13 ... Second internal electrode layer 13a ... Internal electrode pattern 14 ... Outer dielectric layer 14a ... Outer green sheet 20 ... First lead insulation region 21 ... Second lead Insulating region 22 ... 1st lead part 23 ... 2nd lead part 24 ... Gap 26 ... Projection part 28 ... Thick part 50 ... Planned cutting line

Claims (2)

An element body in which a plurality of internal electrode layers laminated so as to face each other through a ceramic layer are formed;
A laminated electronic component having a terminal electrode provided on a side end surface of the element body,
A gap of a predetermined interval is formed between the terminal electrode and the side end surface,
A lead portion protruding from the side end surface through the gap and connected to the terminal electrode is formed integrally with the internal electrode layer at an end portion in the side end surface direction of the internal electrode layer,
A tip portion of the protruding portion protruding from the side end surface of the lead portion is embedded in the terminal electrode, and a thick portion thicker than the thickness of the lead portion is formed,
The internal electrode main component of the metal component constituting the internal electrode layer is different from the terminal electrode main component of the terminal electrode to which the lead portion of the internal electrode is connected,
The protrusions and the thick portion is Ri tare composed of an alloy of the terminal electrode main component and the internal electrode main component,
When the thickness of the lead portion located in the gap is t1, and the thickness of the thick portion is t2,
multilayer electronic component t2 / t1 is you, characterized in that 1.3 to 2.0.   The multilayer electronic component according to claim 1, wherein the internal electrode main component is nickel and the terminal electrode main component is copper.

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