Ceramic electronic component
11659659 · 2023-05-23
Assignee
Inventors
- Naoya MURAKITA (Kyoto, JP)
- Yoshihito Otsubo (Kyoto, JP)
- Issei Yamamoto (Kyoto, JP)
- Yuta Morimoto (Kyoto, JP)
Cpc classification
H05K2203/0597
ELECTRICITY
H05K2201/099
ELECTRICITY
H05K2201/0376
ELECTRICITY
H05K1/115
ELECTRICITY
H05K2201/09909
ELECTRICITY
International classification
Abstract
A ceramic electronic component of the present disclosure includes a component body including a ceramic layer, at least one terminal electrode provided on one main surface of the component body, and an insulating covering layer provided across the ceramic layer and the terminal electrode to cover part, instead of an entire circumference, of a peripheral edge portion of the terminal electrode, wherein when viewed in plan view from one main surface of the component body, the covering layer intersects with the terminal electrode at a non-perpendicular angle at an intersection of the covering layer and the terminal electrode not covered with the covering layer.
Claims
1. A ceramic electronic component comprising: a component body including a ceramic layer; at least one terminal electrode provided on one main surface of the component body; and at least one insulating covering layer each provided across the ceramic layer and the at least one terminal electrode to separately cover a part, instead of an entire circumference, of a peripheral edge portion of each one of the at least one terminal electrode, wherein when viewed in plan view from one main surface of the component body, each one of the at least one insulating covering layer intersects with each one of the at least one terminal electrode at a non-perpendicular angle at least two intersections of the insulating covering layer and the terminal electrode not covered with the insulating covering layer, wherein a bottom surface of the insulating covering layer is tapered toward a top surface of the terminal electrode, and wherein when viewed in plan view from one main surface of the component body, a tip of the insulating covering layer outside of an intersection at which the insulating covering layer and the terminal electrode intersect protrudes from the terminal electrode and is provided on a surface of the ceramic layer, wherein the tip of the insulating covering layer has a curved shape.
2. The ceramic electronic component according to claim 1, wherein when viewed in plan view from one main surface of the component body, the insulating covering layer intersects with the terminal electrode so that an angle between the insulating covering layer and the terminal electrode is an acute angle at the intersection.
3. The ceramic electronic component according to claim 1, wherein a relationship of α.sub.3<α.sub.1<α.sub.2 is established where a coefficient of linear expansion of the ceramic layer is α.sub.1, a coefficient of linear expansion of the terminal electrode is α.sub.2, and a coefficient of linear expansion of the insulating covering layer is α.sub.3.
4. The ceramic electronic component according to claim 1, wherein when viewed in plan view from one main surface of the component body, the insulating covering layer intersects with the terminal electrode so that an angle between the insulating covering layer and the terminal electrode is an obtuse angle at the intersection.
5. The ceramic electronic component according to claim 2, wherein the insulating covering layer has a curved shape toward the intersection.
6. The ceramic electronic component according to claim 2, wherein when viewed in plan view from one main surface of the component body, a tip of the insulating covering layer protrudes from the terminal electrode and is provided on a surface of the ceramic layer.
7. The ceramic electronic component according to claim 2, wherein a relationship of α.sub.3<α.sub.1<α.sub.2 is established where a coefficient of linear expansion of the ceramic layer is α.sub.1, a coefficient of linear expansion of the terminal electrode is α.sub.2, and a coefficient of linear expansion of the insulating covering layer is α.sub.3.
8. The ceramic electronic component according to claim 5, wherein when viewed in plan view from one main surface of the component body, a tip of the insulating covering layer protrudes from the terminal electrode and is provided on a surface of the ceramic layer.
9. The ceramic electronic component according to claim 5, wherein a relationship of α.sub.3<α.sub.1<α.sub.2 is established where a coefficient of linear expansion of the ceramic layer is α.sub.1, a coefficient of linear expansion of the terminal electrode is α.sub.2, and a coefficient of linear expansion of the insulating covering layer is α.sub.3.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
DETAILED DESCRIPTION OF THE DISCLOSURE
(13) Hereinafter, the multilayer ceramic electronic component of the present disclosure will be described. The present disclosure is not limited to the following configurations, but can be applied by appropriately changing the configurations within a range not changing the gist of the present disclosure. Note that a combination of two or more individual desirable configurations described below is also included in the present disclosure.
(14) The ceramic electronic component of the present disclosure is a ceramic electronic component that can be mounted on a mounting board. The present disclosure can be applied to various laminated ceramic electronic components such as multilayer ceramic board. However, the ceramic electronic component of the present disclosure is not limited to the laminated structure, and may be a single-layer structure.
(15)
(16) The ceramic electronic component 1 shown in
(17)
(18) As shown in
(19) The planar shape of the terminal electrode 20 is not particularly limited, but is preferably a square shape or a substantially rectangular shape as shown in
(20) Although not shown, it is preferable that a plating film be formed on the surface of the terminal electrode 20. In this case, the plating film is preferably formed so as to cover part of the covering layer 30 in addition to the entire terminal electrode 20.
(21) In the present embodiment, as shown in
(22) As shown in
(23) In this way, the ceramic electronic component of the present disclosure is characterized in that when viewed in plan view from one main surface of the component body, the covering layer intersects with the terminal electrode at a non-perpendicular angle at the intersection of the covering layer and the terminal electrode not covered with the covering layer.
(24) Since the exposed area of the terminal electrode 20 can be increased when a part of the peripheral edge portion of the terminal electrode 20 is covered with the covering layer 30 as shown in
(25) Furthermore, unlike the case where the terminal electrode 20 is covered with the covering layer 30 so that the covering layer 30 intersects with the terminal electrode 20 perpendicularly as shown in
(26)
(27) In the ceramic electronic component of the present disclosure, it is preferable that as shown in
(28) When the covering layer has a curved shape as shown in
(29) In the ceramic electronic component of the present disclosure, when the angle θ.sub.1 formed by the covering layer and the terminal electrode is an acute angle, the angle θ.sub.1 is preferably 20° or more, and preferably 60° or less.
(30) In the ceramic electronic component of the present disclosure, as shown in
(31) When the covering layer 30 has a curved shape toward the intersection X, it may have an upwardly convex curved shape or a downwardly convex curved shape. The top of the curved shape may be located outside or inside the terminal electrode 20. Further, it may have a curved shape having a plurality of curved portions.
(32)
(33) When the covering layer 30 has a linear shape toward the intersection X, it may have a linear shape having a plurality of curved portions.
(34) In the ceramic electronic component of the present disclosure, it is preferable that as shown in
(35) When the tip of the covering layer 30 protrudes from the terminal electrode 20 and is provided on the surface of the ceramic layer 11, it is preferable that the tip of the covering layer 30 have a curved shape. In this case, the stress applied to the tip of the covering layer 30 can be more dispersed.
(36) When the tip of the covering layer 30 has a curved shape, it is preferable that as shown in
(37)
(38) When the tip of the covering layer 30 has a linear shape, it may have a linear shape having a plurality of curved portions.
(39)
(40) When the tip of the covering layer protrudes from the terminal electrode, it is preferable that the length of the covering layer protruding from the terminal electrode (length indicated by D.sub.1 in
(41) The length D.sub.1 of the covering layer protruding from the terminal electrode is not particularly limited, and may be, for example, 4 times or less or 2 times or less the width W.sub.1 of the covering layer covering the terminal electrode. Further, the length D.sub.1 of the covering layer protruding from the terminal electrode may be equal to or greater than the width W.sub.1 of the covering layer covering the terminal electrode.
(42) In the ceramic electronic component of the present disclosure, it is preferable that the relationship of α.sub.3<α.sub.1<α.sub.2 be established where the coefficient of linear expansion of the ceramic layer is α.sub.1, the coefficient of linear expansion of the terminal electrode is α.sub.2, and the coefficient of linear expansion of the covering layer is α.sub.3.
(43)
(44) The coefficient of linear expansion is obtained as the values measured by thermomechanical analysis (TMA) from room temperature to 500° C. at a heating rate of 5° C./rain.
(45) Until this point, an embodiment is described in which the covering layer intersects with the terminal electrode so that the angle formed by the covering layer and the terminal electrode is an acute angle at the intersection of the terminal electrode not covered with the covering layer and the covering layer. However, the covering layer may intersect with the terminal electrode so that the angle formed by the covering layer and the terminal electrode is an obtuse angle at the intersection of the terminal electrode not covered with the covering layer and the covering layer.
(46)
(47) With the structures shown in
(48) Further, in the structures shown in
(49) In the ceramic electronic component of the present disclosure, when the angle θ.sub.2 formed by the covering layer and the terminal electrode is an obtuse angle, the angle θ.sub.2 is preferably 120° or more, and preferably 160° or less.
(50) As shown in
(51) Alternatively, the covering layer 30 may have a linear shape toward the intersection X. In this case, it may have a linear shape having a plurality of curved portions.
(52) As shown in
(53) When the tip of the covering layer 30 has a curved shape, it is preferable that as shown in
(54) Alternatively, when the tip of the covering layer 30 protrudes from the terminal electrode 20 and is provided on the surface of the ceramic layer 11, the tip of the covering layer 30 may have a linear shape. When the tip of the covering layer 30 has a linear shape, it may have a linear shape having a plurality of curved portions. Further, the tip end portion of the covering layer 30 may not protrude from the terminal electrode 20 and may be at the same position as the end face of the terminal electrode 20.
(55) When the tip of the covering layer protrudes from the terminal electrode, it is preferable that the length of the covering layer protruding from the terminal electrode (length indicated by D.sub.2 in
(56) The length D.sub.2 of the covering layer protruding from the terminal electrode is not particularly limited, and may be, for example, 4 times or less or 2 times or less the width W.sub.2 of the covering layer covering the terminal electrode. Further, the length D.sub.2 of the covering layer protruding from the terminal electrode may be equal to or greater than the width W.sub.2 of the covering layer covering the terminal electrode.
(57) When the angle formed by the covering layer and the terminal electrode is an obtuse angle, it is also preferable that the relationship of α.sub.3<α.sub.1<α.sub.2 be established where the coefficient of linear expansion of the ceramic layer is α1, the coefficient of linear expansion of the terminal electrode is α2, and the coefficient of linear expansion of the covering layer is α3.
(58) The ceramic electronic component of the present disclosure is preferably manufactured as follows. Hereinafter, an example of a method of manufacturing the ceramic electronic component 1 shown in
(59) First, a plurality of ceramic green sheets to be the plurality of ceramic layers 11 is prepared. The ceramic green sheet is formed, for example, by applying the doctor blade method or the like to the ceramic slurry on the carrier film.
(60) The thickness of the ceramic green sheet is, for example, 5 μm or more and 100 μm or less.
(61) The ceramic slurry includes, for example, a ceramic powder, a binder, a plasticizer and the like. An example of the ceramic material contained in the ceramic green sheet may include a low-temperature sintered ceramic (LTCC) material. The low-temperature sintered ceramic material is a ceramic material that can be sintered at a temperature of 1000° C. or lower and can be simultaneously fired with Au, Ag, Cu, and the like having a small resistivity. Examples of the low-temperature sintered ceramic material include, specifically, a glass composite low-temperature sintered ceramic material made by mixing borosilicate glass with ceramic powders such as alumina, zirconia, magnesia, and forsterite, a crystallized glass-based low-temperature sintered ceramic material including ZnO—MgO—Al.sub.2O.sub.3—SiO.sub.2-based crystallized glass, a non-glass low-temperature sintered ceramic materials including BaO—Al.sub.2O.sub.3—SiO.sub.2 ceramic powder and Al.sub.2O.sub.3—CaO—SiO.sub.2—MgO—B.sub.2O.sub.3 ceramic powder.
(62) The inner conductor film 12 and the via conductor 13 are formed on a specific ceramic green sheet using a conductive paste. The inner conductor film 12 is formed, for example, by printing a conductive paste using a method such as screen printing. The via conductor 13 is formed by, for example, irradiating a ceramic green sheet with a laser beam or applying a mechanical punch to provide a through hole, and filling the through hole with a conductive paste.
(63) The conductive paste includes, for example, a conductive metal powder, a binder, a plasticizer, and the like. A co-based material (ceramic powder) for adjusting the shrinkage rate may be added to the conductive paste. Examples of the conductive metal material contained in the conductive paste include a metal or the like containing at least one of Ag, Ag—Pt alloy, Ag—Pd alloy, Cu, Ni, Pt, Pd, W, Mo and Au as a main component. Among these conductive metal materials, Ag, Ag—Pt alloy, Ag—Pd alloy and Cu have low resistivity, and therefore can be more preferably used especially in a conductor pattern for high-frequency.
(64) In addition, as a constituent material of the covering layer 30, the mixed raw material powder obtained by adding and mixing an appropriate amount of alumina (Al.sub.2O.sub.3) powder to the ceramic powder for the ceramic layer 11 described above, is dispersed and kneaded in an organic vehicle to prepare a ceramic paste for the covering layer.
(65) The organic vehicle is a mixture of a binder and a solvent, and the types of the binder and the solvent and their blending ratios are not particularly limited. Examples of the organic vehicle may include alcohol such as terpineol, isopropylene alcohol, butyl carbitol, or butyl carbitol acetate in which an acrylic resin, an alkyd resin, a butyral resin, an ethyl cellulose, or the like is dissolved. In addition, various dispersants, plasticizers, and activators may be added as needed.
(66) The coefficient of linear expansion of the covering layer can be adjusted by adjusting the amount of alumina powder added when producing a ceramic paste for the covering layer. As a result, it is preferable that the relationship of α.sub.3<α.sub.1<α.sub.2 be established where the coefficient of linear expansion of the ceramic layer is α.sub.1, the coefficient of linear expansion of the terminal electrode is α.sub.2, and the coefficient of linear expansion of the covering layer is α.sub.3. For example, it is preferable that the coefficient of linear expansion of the ceramic layer α.sub.1 be 10 ppm/° C., the coefficient of linear expansion of the terminal electrode α.sub.2 be 16 ppm/° C., and the coefficient of linear expansion of the covering layer α.sub.3 be 9 ppm/° C.
(67) The terminal electrode 20 is formed in the ceramic green sheet disposed on one main surface after laminating by using the above-mentioned conductive paste. The terminal electrode 20 is formed, for example, by printing a conductive paste using a method such as screen printing.
(68) The thickness of the terminal electrode 20 after printing is, for example, 10 μm or more and 20 μm or less.
(69) After that, the ceramic paste for the covering layer is printed so as to cover part, instead of the entire circumference, of the peripheral edge portion of the terminal electrode 20 by a method such as screen printing. For example, printing is performed using a screen plate on which the covering layer 30 having the shape shown in
(70) The thickness of the covering layer 30 after printing is, for example, 20 μm or more and 30 μm or less. The amount of overlap between the covering layer 30 and the terminal electrode 20 is, for example, 30 μm or more and 200 μm or less.
(71) The step of printing the ceramic paste for the covering layer may be carried out on the ceramic green sheet as described above, or may be carried out before the firing step is started after the laminating step described later is completed.
(72) An unfired component body 10 is produced by laminating and pressure bonding a plurality of ceramic green sheets in a predetermined order.
(73) The obtained unfired component body 10 is fired to obtain the sintered component body 10. Here, the inner conductor film 12, the via conductor 13, and the terminal electrode 20 are also sintered.
(74) When necessary, a plating step is carried out to form a plating film on the terminal electrode 20. As a result, the ceramic electronic component 1 shown in
(75) In the ceramic electronic component 1 shown in
(76) When the above-mentioned step is performed in the state of a mother electronic component in which it is possible to produce the plurality of ceramic electronic components 1, the step of dividing the mother electronic component to produce each ceramic electronic component 1 is further performed.
(77) The ceramic electronic component of the present disclosure is not limited to the above embodiments, and various applications and modifications may be made within the scope of the present disclosure with regard to the configuration, manufacturing conditions, and the like of the ceramic electronic component.
(78) In the ceramic electronic component of the present disclosure, it is preferable that the covering layer do not intersect with the terminal electrode perpendicularly at all intersections of the intersections of the terminal electrode not covered with the covering layer and the covering layer, but the covering layer may not intersect with the terminal electrode perpendicularly at at least one intersection.
(79) The planar shape of the tip of the covering layer may be the same or different. For example, while the covering layer intersects with the terminal electrode so that the angle formed by the covering layer and the terminal electrode is an acute angle at one intersection, the covering layer may intersect with the terminal electrode so that the angle formed by the covering layer and the terminal electrode is an obtuse angle at another intersection. 1: Ceramic electronic component 10: Component body 10a: One main surface of component body 11: Ceramic layer 12: Inner conductor film 13: Via conductor 20: Terminal electrode 30: Covering layer D.sub.1, D.sub.2, Length of covering layer protruding from terminal electrode W.sub.1, W.sub.2, Width of covering layer covering terminal electrode X: Intersection of terminal electrode not covered with covering layer and covering layer θ.sub.1, θ.sub.2: Angle formed by covering layer and terminal electrode