TWI387984B - Stacking electronics devices and producing methods - Google Patents

Description

Laminated electronic component and method of making same

The present invention relates to a laminated electronic component and a method of manufacturing the same, and more particularly to a laminated electronic component in which a dielectric layer and an internal electrode layer are thinned and multilayered, such as a laminated ceramic capacitor, and a method of manufacturing the same.

In recent years, a multilayer ceramic capacitor which is a type of laminated electronic component has been thinned and multilayered in a dielectric layer and an internal electrode layer in order to reduce the size and capacitance (for example, JP-A-11-251173).

However, in the conventional laminated electronic component, since the dielectric layer and the internal electrode layer are thinned and the area ratio of the internal electrode layer to the dielectric layer is increased, the bonding region between the dielectric layers is gradually reduced, thereby generating The problem of reduced mechanical strength of the electronic component body. Further, the difference between the thickness of the dielectric layer and the thickness of the internal electrode layer is small, and in the laminating step, since the dielectric green sheet is difficult to absorb the step portion of the internal electrode pattern, after lamination or after firing, There is a problem in that separation easily occurs between layers of the electronic component body.

An object of the present invention is to provide a laminated electronic component capable of improving the mechanical strength of an electronic component body and suppressing separation between layers even when a thin layer of a dielectric layer and an internal electrode layer is multilayered, and a method for producing the same.

The laminated electronic component of the present invention has external power on an end face of an electronic component body formed by alternately laminating a plurality of dielectric layers and internal electrode layers A multilayer laminated electronic component characterized in that a portion of the dielectric layer in the dielectric layer is a dielectric layer having a thickness greater than that of other dielectric layers.

Thus, even if a thin layer of the dielectric layer and the internal electrode layer is multilayered, the mechanical strength of the electronic component body can be improved, and separation between layers can be suppressed.

In the laminated electronic component, the layer configuration ratio of the thick dielectric layer to the other dielectric layer (the number of layers of the thick dielectric layer/the number of other dielectric layers) is preferably 1/5 to 1 /20.

Further, in the laminated electronic component, the thick dielectric layer and the other dielectric layers are preferably homogenous materials. Further, when the thickness of the other dielectric layer is t1 and the thickness of the thick dielectric layer is t2, it is preferable to satisfy the relationship of t2/t1≧1.2.

By setting the material of the thick dielectric layer to be uniform with the other dielectric layers as described above, and by setting the thickness ratio as described above, it is possible to integrate the other dielectric layers and the thick dielectric layer, and it is possible to improve the strength.

The present invention is suitable for the case where the other dielectric layers are thin layers, and specifically, it is suitable for other dielectric layers having a thickness of 3 μm or less, and is particularly suitable for the case of 1 to 2 μm. Further, the thickness of the internal electrode layer is preferably 2 μm or less, and particularly preferably 0.1 to 1.8 μm.

Further, in the laminated electronic component of the present invention, the average crystal grain size of the crystal grains of the ceramic constituting the other dielectric layer is Φ 1, and the crystal grains of the ceramic constituting the thick dielectric layer are formed. When the average crystal grain size is Φ 2 , it is preferable to satisfy the relationship of Φ 2 / Φ 1 ≧ 1.1, and the internal electrode layer is preferably a metal foil, and the metal foil is preferably a plated film.

In the laminated electronic component, the larger the particle diameter of the crystal grains constituting the dielectric layer, the higher the dielectric constant of the dielectric. Therefore, by setting the average crystal grain size constituting the dielectric to the above range, The reduction in electrostatic capacitance due to thickening of a portion of the dielectric layer is suppressed.

Further, in the present invention, if the internal electrode layer is formed of a plating film, homogenization can be formed, thickness unevenness can be reduced, and the effective area can be increased, and the internal electrode layer can be made extremely thin.

The method for producing a laminated electronic component according to the present invention is characterized in that it has a step of preparing a dielectric green sheet containing at least a dielectric powder and a dielectric green sheet having a thickness larger than that of the dielectric green sheet, and the dielectric green sheet and the a step of forming an internal electrode pattern on the thick dielectric green sheet, a step of laminating the dielectric green sheet on which the internal electrode pattern is formed, and the thick dielectric green sheet to form a laminated molded body, and cutting the laminated molded body A step of forming an electronic component main body molded body and baking it.

According to such a manufacturing method, even if the dielectric green sheet or the internal electrode pattern is thinned, since the dielectric green sheet having a large thickness is interposed, the embedding property of the internal electrode pattern on the dielectric green sheet can be improved, thereby eliminating The step caused by the internal electrode pattern can easily prevent delamination even after lamination and firing.

Further, in the manufacturing method of the present invention, the layer composition ratio of the thicker dielectric green sheet and the dielectric green sheet (the number of layers of the thick dielectric green sheet/the number of layers of the dielectric green sheet) is preferably 1/5 to 1 /20, the thicker dielectric green sheet and the dielectric green sheet are preferably homogenous materials, when the thickness of the dielectric green sheet is tG1, and the thickness of the thick dielectric green sheet is tG2, the best When the relationship of tG2/tG1≧1.2 is satisfied, the average particle diameter of the dielectric powder constituting the dielectric green sheet is Φ G1 , and the average particle diameter of the dielectric powder constituting the thick dielectric green sheet is Φ G2 . Preferably, the relationship of Φ G2 / Φ G1 ≧ 1.1 is satisfied, and the internal electrode pattern is preferably a metal foil, and the metal foil is preferably a plated film.

By the above, the dielectric powder contained in the dielectric green sheet and the thick dielectric green sheet is a particle diameter ratio (Φ 2 / Φ 1 ≧ 1.1) as described above, even if a part of the dielectric green sheet is thickened. Further, the firing shrinkage ratio can be suppressed, and the internal stress before and after the firing can be reduced.

As described above, according to the present invention, even if the dielectric layer and the internal electrode layer are thinned, the mechanical strength of the electronic component body can be improved, and the separation between the layers can be suppressed.

One embodiment of the laminated electronic component of the present invention will be described in detail. The first drawing is a schematic cross-sectional view of a multilayer ceramic capacitor as a representative example of the laminated electronic component of the present invention. The laminated electronic component has external electrodes 3 formed on both end faces 2 of the electronic component body 1. The electronic component body 1 is constructed by laminating the dielectric layer 10 and the internal electrode layer 7 alternately. The internal electrode layer 7 is interactively connected to the external electrode 3 on the same end face 2 of the electronic component body 1.

Further, in the present invention, it is important that a part of the dielectric layers among the dielectric layers 10 is a dielectric layer 8 thicker than the other dielectric layers 5. In addition, the thickness of the other dielectric layer 5 is set to t1, and the The ratio t2/t1 when the thickness of the thick dielectric layer 8 is t2 is more preferably 1.2 or more.

Further, the thick dielectric layer 8 is preferably made of a homogenous material to the other dielectric layers 5, because the sinterability of the other dielectric layers 5 and the thick dielectric layer 8 is improved to improve the mechanical strength. Here, the "homogeneous material" means a material in which the main component is composed of the same element.

Further, the average crystal grain size of the crystal grains of the ceramic constituting the other dielectric layer 5 is Φ 1, and the average crystal grain size of the crystal grains of the ceramic constituting the thick dielectric layer 8 is Φ 2 when Φ 2 The ratio of /Φ 1 is preferably 1.1 or more, more preferably 1.15 or more. Specifically, the average crystal grain size Φ 1 is preferably about 0.1 to 1 μm, and the average crystal grain size Φ 2 is preferably from about 0.2 to 1.2 μm. On the other hand, when the dielectric layer 8 thicker than the other dielectric layers 5 is not inserted in the electronic component body 1, the mechanical strength of the electronic component 1 cannot be improved.

In the present invention, the term "thin-layer multilayering" means that the thickness of the other dielectric layer 5 is 3 μm or less, the thickness of the internal electrode layer 7 is 2 μm or less, and the dielectric layer and the internal electrode layer are laminated by 100 or more layers, respectively. The present invention is suitable for such a laminated electronic component which is thinned or multilayered. It is particularly preferable that the thickness of the other dielectric layer 5 is 1 to 2 μm, and the thickness of the internal electrode layer 7 is 0.1 to 1.8 μm.

Further, in the present invention, the layer constitution ratio of the thick dielectric layer 8 and the other dielectric layers 5 (the number of layers of the thick dielectric layer 8 / the number of layers of the other dielectric layers 5) is preferably 1/5 to 1/20.

The dielectric layers 5 and 8 are, for example, ceramic layers including a crystal phase mainly composed of BaTiO ₃ or the like.

The internal electrode layer 7 constituting the electronic component main body 1 of the present invention is preferably a metal foil, and is preferably formed of a plating film. Further, the plating film is preferably a base metal material as a main component, and particularly preferably one of Ni and Cu or an alloy thereof.

Next, a method of manufacturing a multilayer ceramic capacitor which is an application example of the laminated electronic component of the present invention will be described. The second drawings (a) to (d) are process drawings for manufacturing the laminated ceramic capacitor.

(a) First, a ceramic slurry is prepared by adding a sintering aid, a binder, a solvent, or the like to a dielectric powder such as BaTiO ₃ , and then coating the ceramic slurry on a carrier film 51 to form a carrier slurry 51. The dielectric green sheet 53a. Further, in the present invention, it is important to prepare a dielectric green sheet 53b thicker than the dielectric green sheet 53a. The thick dielectric green sheet 53b and the dielectric green sheet 53a are preferably homogenous materials for the purpose of facilitating integral firing with the dielectric green sheet 53a. Further, the thickness of the dielectric green sheet 53a is tG1, and the ratio of the thickness of the thick dielectric green sheet 53b to tG2 is preferably 1.2 or more.

Further, the average particle diameter of the dielectric powder constituting the dielectric green sheet 53a is Φ G1 , and the Φ G2 / Φ G1 ratio when the average particle diameter of the dielectric powder constituting the thick dielectric green sheet 53b is Φ G2 is more preferable. Above 1.1.

In the present invention, the thickness of the dielectric green sheet 53a is preferably 12 μm or less. In particular, the thickness of the laminated electronic component is preferably in the range of 1.5 to 5 μm.

(b) Then, on the dielectric green sheet 53a and the thicker dielectric green sheet 53b Upper, internal electrode patterns 54a, 54b are formed, respectively. At this time, the effective area of the internal electrode patterns 54a and 54b is preferably 60% or more, and particularly preferably 65% or more. Further, in order to eliminate the step caused by the internal electrode patterns 54a and 54b formed on the dielectric green sheet 53a and the thick dielectric green sheet 53b, an organic resin or the like may be applied around the internal electrode patterns 54a and 54b. Further, it is preferable that the coating thickness of the organic resin is formed so as to correspond to the thickness of the internal electrode patterns 54a and 54b.

(c) Then, the dielectric green sheets 53a and the thick dielectric green sheets 53b on which the internal electrode patterns 54a and 54b are formed are laminated in a specific configuration, and then, on the upper and lower surfaces, by laminating a plurality of layers in which internal electrode patterns are not formed The dielectric green sheet 53a is heated and pressurized to form a laminated molded body 57.

The layer configuration ratio of the dielectric green sheet 53a and the thick dielectric green sheet 53b of the multilayer molded body 57 (the number of layers of the thick dielectric green sheet 53b / the number of layers of the dielectric green sheet 53a) is more preferably 1/5 to 1/ 20.

Further, as shown in the second (c) and third figures, the internal electrode patterns 54a and 54b are composed of a plurality of internal electrodes regularly arranged on the surfaces of the dielectric green sheets 53a and the thick dielectric green sheets 53b. Further, the internal electrode pattern 54a and the internal electrode pattern 54b are stacked with respect to a length of about half of the longitudinal direction of the internal electrode. Further, in the third drawing, although the internal electrode patterns 54b are drawn wider than the internal electrode patterns 54a for convenience, their widths are preferably the same.

(d) Then, the laminated molded body 57 is cut into a lattice shape along the cutting portion C shown in the second (c) and third drawings, and a plurality of electrons are formed at a time. Component body molded body 59. The cutting portion C is a surface perpendicular to the dielectric green sheets 53a, 53b passing between the respective internal electrodes constituting the internal electrode pattern 54a or between the internal electrodes constituting the internal electrode pattern 54b and the dielectric green sheets 53a, 53b. Vertical face.

The obtained electronic component main body molded body 59 is subjected to binder removal treatment at 250 to 300 ° C in the atmosphere or 500 to 800 ° C in a low oxygen atmosphere having a partial pressure of oxygen of 0.1 to 1 Pa, and then in a non-oxidizing atmosphere. The main body 1 of the electronic component was produced by firing at 1250 to 1350 ° C for 2 to 3 hours. Further, in order to obtain a desired dielectric property, heat treatment is performed at 900 to 1100 ° C for 5 to 15 hours under a low partial pressure of oxygen having an oxygen partial pressure of about 0.1 to 10 ^-4 Pa.

Finally, an external electrode paste is applied onto the end surface 11 of the obtained electronic component body 1 and baked to form the external electrode 3. Then, a Ni plating film and a Sn plating film were formed on the external electrode 3 to form a multilayer ceramic capacitor.

Further, as the internal electrode pattern 54 used in the present invention, not only a printed film of a metal paste but also a plating film, a sputtered film, or a vapor deposited film can be used.

[Industrial use possibility]

The present invention is suitable as a small-sized, high-capacity laminated ceramic capacitor.

[Examples]

Hereinafter, the examples and comparative examples will be described in further detail, but the present invention is not limited to the following examples.

A laminated ceramic capacitor which is one type of laminated electronic component was produced as follows. First, a dielectric powder containing BaTiO ₃ as a main component and having an average particle diameter of a crystal diameter ratio (average crystal grain size ratio) shown in Table 1 is prepared, and each ceramic composed of a dielectric powder, an organic binder, and a solvent is prepared. In the slurry, two kinds of green sheets (dielectric green sheets and thick dielectric green sheets) having different thicknesses were produced. The thickness of the dielectric green sheet was set to 3.5 μm, and the thickness of the thick dielectric green sheet was adjusted so that the thickness ratio (t2/t1) of the dielectric layer after firing reached the ratio shown in Table 1. The average particle diameter Φ G2 of the dielectric powder constituting the thick dielectric green sheet is 0.5 μm, and the average particle diameter Φ G1 of the dielectric powder constituting the dielectric green sheet is in accordance with the average crystal grain size ratio of the dielectric layer after firing (Φ 2 / Φ 1) The ratio shown in Table 1 was adjusted.

Then, a substrate plate made of a stainless steel plate subjected to mirror processing was used for the internal electrode pattern, and a photosensitive resist resin was applied to the surface of the internal electrode pattern, and after exposure and cleaning, a mask pattern was formed.

Thereafter, the stainless steel plate substrate was immersed in a Ni plating solution, and a plating treatment was performed to form a metal film containing Ni as a main component of 4 mm × 1 mm and an average thickness of 0.5 μm.

Thereafter, the internal electrode pattern is thermocompression-bonded onto the dielectric green sheet and the thick dielectric green sheet under conditions of 80 ° C and 80 kg/cm ² to form a dielectric material forming an internal electrode pattern. Sheets and thicker dielectric green sheets. The effective area of the internal electrode with respect to each dielectric layer was set to 65%.

Then, the dielectric green sheets and the thick dielectric green sheets to which the internal electrode patterns were transferred were laminated in a total of 200 sheets at a composition ratio shown in Table 1, and laminated by a temperature of 100 ° C and a pressure of 80 kgf/cm ² . It becomes a laminated body.

Thereafter, the laminated molded body was cut into a lattice shape to obtain an electronic component main body molded body. At one end surface of the electronic component main body molded body, one end of the internal electrode pattern is alternately exposed. Further, an electrode pattern of the internal electrode layers stacked in the thickness direction is formed without a positional deviation.

Then, after the electronic component main body molded body is subjected to binder removal treatment at 500 ° C in a low oxygen atmosphere at a partial pressure of oxygen of 0.1 to 1 Pa in the atmosphere, the partial pressure of oxygen is 10 ^{-7 .} The Pa was fired at 1300 ° C for 2 hours in a non-oxidizing atmosphere, and then subjected to reoxidation treatment at 1000 ° C for 10 hours under a low partial pressure of oxygen having an oxygen partial pressure of 0.01 Pa to obtain an electronic component body.

Finally, the electronic component body obtained as described above was coated with a Cu paste containing glass powder on each end surface on which the internal electrode layer was exposed and an extension portion was formed, and then baked at 900 ° C in a nitrogen atmosphere. Thereafter, a Ni plating layer and a Sn plating layer were formed, and an external electrode electrically connected to the internal electrode layer was formed to form a laminated ceramic capacitor.

The obtained monolithic ceramic capacitor has an outer dimension of 1.25 mm in width, 2.0 mm in length, and 1.25 mm in thickness, sandwiched between the dielectric layers between the internal electrode layers, and the dielectric layer as the sintered body of the dielectric green sheet has a thickness t1 of 2.5. Μm, the ratio of the thickness t2 of the dielectric layer as the sintered body of the thicker dielectric green sheet to the thickness t1 is a value shown in Table 1.

After the firing, the obtained multilayer ceramic capacitor was subjected to evaluation of electrostatic capacitance and delamination for each of 100 samples. The delamination is the evaluation of the sample after the section grinding. The mechanical strength was a three-point bending strength test for each of the 20 pieces. The respective measurement results are shown in Table 1.

On the other hand, as a comparative example, a laminated electronic component composed of a dielectric layer (thickness: 2.5 μm) having a uniform thickness in all layers was produced, and was evaluated in the same manner as in the present invention.

As is clear from the results of Table 1, in Sample Nos. 2 to 8 having a thick dielectric layer, the electrostatic capacitance was 4.7 μF or more, the delamination was 2/100 or less, and the mechanical strength was 10 kgf or more. In particular, in Sample Nos. 3 to 8 in which the ratio t2/t1 of the thickness t1 of the dielectric layer to the thickness t2 of the thick dielectric layer was 1.2 or more, the electrostatic capacitance was 4.7 μF or more, and there was no delamination, and the mechanical strength was as high as possible. 10.4kgf. On the other hand, an electronic component body having a dielectric layer of the same thickness (2.5 μm) in a full layer without a thick dielectric layer interposed therebetween In sample No. 1, the electrostatic capacitance was as high as 4.9 μF, but the number of occurrences of delamination was as high as 10/100, and the mechanical strength was as low as 9.5 kgf.

1‧‧‧Electronic component body

2‧‧‧ end face

3‧‧‧External electrode

7‧‧‧Internal electrode layer

5, 10‧‧‧ dielectric layer

8‧‧‧Thick dielectric layer

11‧‧‧ end face

51‧‧‧ carrying film

53a, 53b‧‧‧ dielectric green film

54‧‧‧Internal electrode pattern

54a, 54b‧‧‧ internal electrode pattern

57‧‧‧Laminated molded body

59‧‧‧Electronic component body molded body

C‧‧‧Cutting parts

The first drawing is a schematic cross-sectional view of a multilayer ceramic capacitor as a representative example of the laminated electronic component of the present invention.

The second drawing is a process diagram for manufacturing the laminated electronic component of the present invention.

The third drawing is a plan view showing a cut portion when the laminated molded body is cut.

1‧‧‧Electronic component body

2‧‧‧ end face

3‧‧‧External electrode

7‧‧‧Internal electrode layer

5, 10‧‧‧ dielectric layer

8‧‧‧Thick dielectric layer

Claims (4)

A laminated electronic component is a laminated electronic component having an external electrode on an end surface of an electronic component body formed by alternately laminating a plurality of dielectric layers and internal electrode layers, characterized in that a part of the dielectric in the dielectric layer The layer is a dielectric layer having a thickness greater than that of the other dielectric layers, and when the thickness of the other dielectric layer is t1 and the thickness of the thick dielectric layer is t2, it satisfies t2/t1≧ In the relationship of 1.2, the average crystal grain size of the crystal grains of the ceramic constituting the other dielectric layer is Φ 1, and the average crystal grain size of the crystal grains constituting the dielectric layer having the thick thickness is set to When Φ 2 , the relationship of Φ 2 / Φ 1 ≧ 1.1 is satisfied. The laminated electronic component according to claim 1, wherein the thick dielectric layer is formed in a ratio of layers of the other dielectric layers, that is, the number of layers of the thick dielectric layer/other The number of layers of the dielectric layer is 1/5 to 1/20. A method for producing a laminated electronic component, comprising: a step of preparing a dielectric green sheet containing at least a dielectric powder; and a dielectric green sheet having a thickness thicker than the dielectric green sheet, and the dielectric green sheet and the thickness a step of forming an internal electrode pattern on a thick dielectric green sheet, a step of laminating the dielectric green sheet on which the internal electrode pattern is formed, and a dielectric green sheet having a large thickness to form a laminated molded body, and cutting the laminate a step of forming a molded body of an electronic component body and firing it, wherein the thickness of the dielectric green sheet is tG1, and when the thickness of the thick dielectric green sheet is tG2, satisfies tG2/tG1 The relationship of ≧ 1.2 is such that the average particle diameter of the dielectric powder constituting the dielectric green sheet is Φ G1 , and the dielectric constituting the thick dielectric green sheet is formed. When the average particle diameter of the powder is Φ G2 , the relationship of Φ G2 / Φ G1 ≧ 1.1 is satisfied. The method for manufacturing a laminated electronic component according to claim 3, wherein the thicker dielectric green sheet and the dielectric green sheet have a layer ratio, that is, a layer of a thicker dielectric green sheet. The number of layers of the dielectric/dielectric green sheets is 1/5 to 1/20.