High temperature resistant multilayer ceramic capacitors

Abstract

The present invention discloses a high temperature resistant multilayer ceramic capacitor, comprising a laminate, wherein the two ends of the laminate are respectively connected to a first external electrode and a second external electrode, wherein the laminate further comprises a first ceramic layer and a first internal electrode and a second internal electrode staggered in the first ceramic layer, wherein the first internal electrode is connected to the first external electrode, and the second internal electrode is connected to the second external electrode. The present invention improves the high temperature resistance of the capacitor, and can still maintain a long service life under high temperature conditions, and no defective products are produced after 1000 hours of high temperature load at 150°C.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic capacitors, and in particular to high temperature resistant multilayer ceramic capacitors. Background Art

[0002] Multilayer ceramic capacitors are mainly ceramic chips formed by stacking ceramic dielectric diaphragms with printed inner electrodes in an offset manner and sintering at high temperature. For existing multilayer ceramic capacitors, the stability is not high when used in high temperature environments, and the service life will be greatly shortened, and they need to be replaced frequently, which increases the cost of use. Therefore, it is urgent to develop a new multilayer ceramic capacitor to improve high temperature resistance. Summary of the invention

[0003] Based on the technical problems existing in the background technology, the present invention proposes a high-temperature resistant multilayer ceramic capacitor, which improves the high-temperature resistance of the capacitor and can still maintain a long service life under high temperature conditions.

[0004] The high temperature resistant multilayer ceramic capacitor proposed in the present invention comprises a laminate, wherein two ends of the laminate are respectively connected to a first external electrode and a second external electrode, wherein the laminate further comprises a first ceramic layer and a first internal electrode and a second internal electrode alternately distributed in the first ceramic layer, wherein the first internal electrode is connected to the first external electrode, and the second internal electrode is connected to the second external electrode;

[0005] The first ceramic layer comprises the following raw materials in parts by weight: 100 parts of Ba3(VO4)2, 80-120 parts of Sr2TiO4, 1-10 parts of Yb2O3, and 1-10 parts of Nb2O5.

[0006] Preferably, the stacked body further includes a protective layer, and the protective layer is arranged outside the first ceramic layer.

[0007] Preferably, a second ceramic layer is further provided on the outer sides of both ends of the stack, the second ceramic layer is located between the stack and the first external electrode / the second external electrode, and the second ceramic layer is completely covered by the first external electrode / the second external electrode.

[0008] Preferably, the material of the second ceramic layer is the same as that of the first ceramic layer.

[0009] Preferably, an electroplating layer is further provided on the outer side of the first external electrode / the second external electrode.

[0010] Preferably, the electroplating layer includes a tin electroplating layer and a nickel electroplating layer which are distributed in an annular and staggered manner.

[0011] Preferably, the sintering temperature of the first ceramic layer is 800-1000°C.

[0012] Beneficial technical effects of the present invention:

[0013] (1) The present invention provides a second ceramic layer outside the laminate, and the second ceramic layer is completely covered by the external electrode. The second ceramic layer can provide a better bonding force between the external electrode and the first ceramic layer, and can improve the stability of the capacitor.

[0014] (2) The ceramic layer of the present invention is composed of Ba3(VO4)2, Sr2TiO4, Yb2O3 and Nb2O5, which significantly improves the high temperature resistance of the ceramic capacitor. No defective products are found after 1000 hours of high temperature load at 150°C. In addition, Yb2O3 and Nb2O5 in the ceramic layer also have a certain synergistic promoting effect in improving the high temperature resistance of the capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of a high temperature resistant multilayer ceramic capacitor proposed by the present invention;

[0016] Figure 2 This is a schematic diagram of the structure of the electroplating layer proposed by the present invention.

[0017] In the figure: 1-stacked body, 2-first ceramic layer, 3-first external electrode, 4-first internal electrode, 5-second ceramic layer, 6-second internal electrode, 7-protective layer, 8-electroplating layer, 81-tin electroplating layer, 82-nickel electroplating layer, 9-second external electrode. DETAILED DESCRIPTION

[0018] The present invention will be further explained below in conjunction with specific embodiments.

[0019] Example 1

[0020] Reference Figure 1-2 The high temperature resistant multilayer ceramic capacitor proposed in the present invention comprises a laminate 1, wherein the first external electrode 3 and the second external electrode 9 are connected to the two ends of the laminate 1, respectively, and the laminate 1 further comprises a first ceramic layer 2 and a first internal electrode 4 and a second internal electrode 6 staggered in the first ceramic layer 2, wherein the first internal electrode 4 is connected to the first external electrode 3, and the second internal electrode 6 is connected to the second external electrode 9. The laminate 1 further comprises a protective layer 7, which is arranged outside the first ceramic layer 2.

[0021] A second ceramic layer 5 is further provided on the outer sides of both ends of the stacked body 1 . The second ceramic layer 5 is located between the stacked body 1 and the first external electrode 3 / the second external electrode 9 , and the second ceramic layer 5 is completely covered by the first external electrode 3 / the second external electrode 9 .

[0022] The material of the second ceramic layer 5 is the same as that of the first ceramic layer 2 .

[0023] An electroplating layer 8 is further disposed outside the first external electrode 3 / the second external electrode 9 , wherein the electroplating layer 8 includes a tin electroplating layer 81 and a nickel electroplating layer 82 that are alternately distributed in an annular shape.

[0024] Among them: the first ceramic layer contains the following raw materials in parts by weight: Ba3(VO4)21000g, Sr2TiO41000g, Yb2O350g, Nb2O550g.

[0025] The specific preparation method of the ceramic layer of the present application is as follows:

[0026] S1: Add Ba3(VO4)2 and Sr2TiO4 to anhydrous ethanol solution for ultrasonic activation, then add ethyl orthosilicate and mix well;

[0027] S2: Ammonia water is added to the solution of S1, and after reaction, the solution is dried and sintered at 900°C to obtain a ceramic layer.

[0028] Example 2

[0029] The first ceramic layer of this embodiment contains the following raw materials in parts by weight: Ba3(VO4)2 1000 g, Sr2TiO4 800 g, Yb2O3 10 g, and Nb2O5 10 g.

[0030] The sintering temperature of the first ceramic layer is 800°C.

[0031] Example 3

[0032] The first ceramic layer of this embodiment contains the following raw materials in parts by weight: Ba3(VO4)2 1000 g, Sr2TiO4 1200 g, Yb2O3 100 g, and Nb2O5 100 g.

[0033] The sintering temperature of the first ceramic layer is 1000°C.

[0034] Comparative Example 1

[0035] The first ceramic layer of this embodiment contains the following raw materials in parts by weight: Ba3(VO4)2 1000 g, Sr2TiO4 1000 g, and Yb2O3 100 g.

[0036] The sintering temperature of the first ceramic layer is 900°C.

[0037] Comparative Example 2

[0038] The first ceramic layer of this embodiment includes the following raw materials in parts by weight: Ba3(VO4)2 1000 g, Sr2TiO4 1000 g, and Nb2O5 100 g.

[0039] The sintering temperature of the first ceramic layer is 900°C.

[0040] A high temperature resistance test was carried out on Examples 1-3 and Comparative Examples 1-2 at a temperature of 150° C. The number of defective products after 1000 hours was counted. The results are shown in Table 1.

[0041] Table 1 High temperature resistance test results

[0042] Group Total number of capacitors tested Number of defective capacitors Defective rate (%) Example 1 100 0 0 Example 2 100 0 0 Example 3 100 0 0 Comparative Example 1 100 17 17 Comparative Example 2 100 11 11

[0043] It can be seen from the data in Table 1 that the capacitor of the present invention has no defective products after 1000 hours of high temperature load at 150°C, which shows that the multilayer ceramic capacitor of the present invention has good high temperature resistance. From the results of Example 1, Comparative Example 1 and Comparative Example 2, it can be seen that the Yb2O3 and Nb2O5 added to the ceramic of the present invention also have a certain synergistic promoting effect in improving the high temperature resistance of the capacitor, thereby making the capacitor have excellent high temperature resistance.

Claims

1. A high temperature resistant multilayer ceramic capacitor, characterized in that: A laminated body is provided, wherein two ends of the laminated body are respectively connected to a first external electrode and a second external electrode, and the laminated body further comprises a first ceramic layer and a first internal electrode and a second internal electrode alternately distributed in the first ceramic layer, wherein the first internal electrode is connected to the first external electrode, and the second internal electrode is connected to the second external electrode; The first ceramic layer comprises the following raw materials in parts by weight: 100 parts of Ba3(VO4)2, 80-120 parts of Sr2TiO4, 1-10 parts of Yb2O3, and 1-10 parts of Nb2O5.

2. The high temperature resistant multilayer ceramic capacitor according to claim 1, characterized in that: The stacked body further includes a protective layer disposed outside the first ceramic layer.

3. The high temperature resistant multilayer ceramic capacitor according to claim 1, characterized in that: A second ceramic layer is further disposed outside both ends of the stack, the second ceramic layer is located between the stack and the first external electrode / the second external electrode, and the second ceramic layer is completely covered by the first external electrode / the second external electrode.

4. The high temperature resistant multilayer ceramic capacitor according to claim 3, characterized in that: The material of the second ceramic layer is the same as that of the first ceramic layer.

5. The high temperature resistant multilayer ceramic capacitor according to claim 1, characterized in that: An electroplating layer is also provided on the outer side of the first external electrode / the second external electrode.

6. The high temperature resistant multilayer ceramic capacitor according to claim 5, characterized in that: The electroplating layer comprises a tin electroplating layer and a nickel electroplating layer which are distributed in an annular and staggered manner.

7. The high temperature resistant multilayer ceramic capacitor according to claim 1, characterized in that: The sintering temperature of the first ceramic layer is 800-1000°C.

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