# US 12,002,625 B2 · Ceramic electronic device and manufacturing method of the same

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- Number: US 12,002,625 B2
- Document ID: US12002625B2
- Status: Granted
- Kind: B2
- Application number: 17/883,375
- Filed: 2022-08-08
- Published: 2023-03-16
- Granted: 2024-06-04
- Earliest claimed: 2021-08-31
- Assignees: Taiyo Yuden Co., Ltd.
- Applicants: Taiyo Yuden Co., Ltd.
- Inventors: Yasuyuki Inomata; Kazumichi Hiroi
- Web page: https://patentgrep.com/patent/US12002625B2

## CPC

- H01G 4/1227: {based on alkaline earth titanates}
- B32B 18/00: Layered products essentially comprising ceramics, e.g. refractory products
- C04B 35/4682: {based on BaTiO3 perovskite phase}
- C04B 35/49: containing also titanium oxides or titanates
- C04B 35/64: Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F})
- H01G 4/008: Selection of materials
- H01G 4/012: Form of non-self-supporting electrodes
- H01G 4/30: Stacked capacitors (H01G4/33 takes precedence)
- C04B 2235/3206: Magnesium oxides or oxide-forming salts thereof
- C04B 2235/3208: Calcium oxide or oxide-forming salts thereof, e.g. lime
- C04B 2235/3213: Strontium oxides or oxide-forming salts thereof
- C04B 2235/3215: Barium oxides or oxide-forming salts thereof
- C04B 2235/3225: Yttrium oxide or oxide-forming salts thereof
- C04B 2235/3236: Alkaline earth titanates
- C04B 2235/3244: Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof
- C04B 2235/3262: Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO
- C04B 2235/3418: Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
- C04B 2235/5454: nanometer sized, i.e. below 100 nm
- C04B 2235/6584: at an oxygen percentage below that of air
- C04B 2235/768: Perovskite structure ABO3
- C04B 2235/781: Nanograined materials, i.e. having grain sizes below 100 nm
- C04B 2235/785: Submicron sized grains, i.e. from 0,1 to 1 micron
- C04B 2237/346: Titania or titanates
- C04B 2237/588: by joining layers or articles of the same composition but having different particle or grain sizes
- C04B 2237/704: of one or more of the ceramic layers or articles
- C04B 2237/80: Joining the largest surface of one substrate with a smaller surface of the other substrate, e.g. butt joining or forming a T-joint
- H01G 4/1209: {characterised by the ceramic dielectric material (H01G4/1272, H01G4/1281 take precedence)}
- H01G 4/1245: {containing also titanates}
- H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10)
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

A ceramic electronic device includes a multilayer structure in which a plurality of dielectric layers and a plurality of internal electrode layers are alternately stacked. Each of the plurality of dielectric layers includes ceramic grains of a main component thereof expressed by (Ba1-x-yCaxSry)(Ti1-zZrz)O3 (0<x≤0.2, 0≤y≤0.1, 0≤z≤0.1). D3<D1<D2 is satisfied when an average grain diameter of the ceramic grains of the main component of the plurality of dielectric layers in a section in which each two internal electrode layers is D1, an average grain diameter of the ceramic grains of the main component of first dielectric layers which are located at different height positions from the internal electrode layers is D2, an average grain diameter of the ceramic grains of the main component of second dielectric layers which are located at same height positions of the internal electrode layers is D3.

## Claims

### Claim 1

A ceramic electronic device comprising:
a multilayer structure having a substantially rectangular parallelepiped shape in which a plurality of dielectric layers and a plurality of internal electrode layers are alternately stacked, the plurality of internal electrode layers being alternately exposed to two end faces opposite to each other of the multilayer structure, the multilayer structure including a side margin section at each of side faces thereof that covers lateral side edges of the internal electrodes,
wherein each of the plurality of dielectric layers and each of the side margin sections include, as a main component, ceramic grains of (Ba1-x-yCaxSry)(Ti1-zZrz)O3 (0<x≤0.2, 0≤y≤0.1, 0≤z≤0.1), where the value of x, y, and z may differ depending on layers and locations therein, and
wherein D3<D1<D2 is satisfied, where:
D1 is an average grain diameter of the ceramic grains in the plurality of dielectric layers in a section sandwiched by, and next to, two adjacent internal electrode layers,
D2 is an average grain diameter of the ceramic grains in the side margin section in a region that is located at height positions different from the internal electrode layers, and
D3 is an average grain diameter of the ceramic grains in the side margin section in a region that is located at the same height as the internal electrode layer.

### Claim 2 (depends on 1)

The ceramic electronic device as claimed in claim 1,
wherein the region in the side margin section that is located at the same height as the internal electrode layer in which D3 is defined has a first section and a second section, the first section being closer to the plurality of internal electrode layers than the second section, and
wherein D4′<D3′ is satisfied where D3′ is an average grain diameter of the ceramic grains in the second section, and D4′ is an average grain diameter of the ceramic grains in the first section.

### Claim 3 (depends on 2)

The ceramic electronic device as claimed in claim 2, wherein a width of the first section is 20 μm or more and 80 μm or less.

### Claim 4 (depends on 1)

The ceramic electronic device as claimed in claim 1,
wherein D1 is 100 nm or more and 400 nm or less,
wherein D2 is 200 nm or more and 750 nm or less, and
wherein D3 is 75 nm or more and 200 nm or less.

### Claim 5 (depends on 1)

The ceramic electronic device as claimed in claim 1, wherein a thickness of each of the plurality of internal electrode layers is 0.3 μm or more and 1.5 μm or less.

### Claim 6

A manufacturing method of a ceramic electronic device comprising:
forming an electrode pattern of metal conductive paste on each of a plurality of green sheets that include, as a main component, ceramic particles of (Ba1-x-yCaxSry)(Ti1-zZrz)O3 (0<x≤0.2, 0≤y≤0.1, 0≤z≤0.1);
thereafter, on each of the plurality of green sheets on which the electrode pattern has been formed, forming a first pattern around the electrode pattern, the first pattern including, as a main component, ceramic particles of (Ba1-x-yCaxSry)(Ti1-zZrz)O3 (0<x≤0.2, 0≤y≤0.1, 0≤z≤0.1);
stacking the plurality of green sheets on which the electrode pattern and the first pattern have been formed to form a multilayer structure such that the first patterns are alternately shifted in lateral positions; and
firing the multilayer structure, thereby converting the respective ceramic particles to corresponding ceramic grains, respectively,
wherein an average grain diameter D3 of the ceramic grains in the first pattern after the firing is smaller than an average grain diameter D1 of the ceramic grains in the plurality of green sheets after the firing in a section sandwiched by, and next to, two adjacent electrode patterns, and
wherein an average grain diameter D2 of the ceramic grains in the plurality of green sheets in a section corresponding to the first pattern in lateral position is greater than the average grain diameter D1, thereby satisfying D3<D1<D2.

### Claim 7 (depends on 6)

The method as claimed in claim 6, further comprising:
after the forming of the first pattern and before stacking the plurality of green sheets, forming a second pattern around the first pattern on the each of the plurality of green sheets, a main component of the second pattern being ceramic particles of (Ba1-x-yCaxSry)(Ti1-zZrz)O3 (0<x≤0.2, 0≤y≤0.1, 0≤z≤0.1),
wherein an average particle diameter of the ceramic particles in the second pattern is larger than the average particle diameter of the ceramic particles in the first pattern and is smaller than the average particle diameter of the ceramic particles in the plurality of green sheets.