CN216015093U

CN216015093U - Chip type multilayer ceramic capacitor

Info

Publication number: CN216015093U
Application number: CN202122091197.2U
Authority: CN
Inventors: 古月; 谢波; 易凤举; 罗道隆; 范青富; 蒋贤
Original assignee: Chengdu Hongke Electronic Technology Co ltd
Current assignee: Chengdu Hongke Electronic Technology Co ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2022-03-11
Anticipated expiration: 2031-08-31

Abstract

The utility model relates to a ceramic capacitor field provides a chip multilayer ceramic capacitor, include inner electrode, ceramic body and set up in the end electrode of ceramic body both sides, the end electrode includes four layer upon layer laminated structures, is nickel layer, copper layer, nickel layer, tin lead layer respectively from inside to outside. The terminal electrode can be prevented from warping and falling off.

Description

Chip type multilayer ceramic capacitor

Technical Field

The utility model relates to a ceramic capacitor technical field particularly, relates to a piece formula multilayer ceramic capacitor.

Background

A chip type multi-layer ceramic capacitor (mlcc) -chip capacitor for short is composed of ceramic dielectric films with printed electrodes (internal electrodes) and stacked in staggered mode, ceramic chip formed by one-step high-temp sintering, and metal layers (end electrodes) sealed at both ends of chip to form a monolithic structure, so called monolithic capacitor.

According to the development trend of the existing capacitor products, due to the excellent electrical property and relatively low-cost material acquisition, copper is generally applied to the preparation of the capacitor terminal electrode. However, due to the inherent characteristics of the copper paste, the defects such as holes exist after the firing of the terminal, which can cause the permeation of Ni or acid electroplating solution during electroplating to damage the glass phase of the terminal electrode, and finally cause the terminal electrode to warp and fall off. The schematic diagram of Ni infiltration is shown in FIG. 1, and holes are ubiquitous in the Cu layer of the rear end electrode after the end burning is finished; during electroplating, the electroplating solution and the Ni layer can penetrate into the holes, and even enter into the contact interface between the terminal electrode and the ceramic body. This phenomenon can lead to failure of the capacitor product when subjected to an ambient temperature-type evaluation, and the ambient temperature is unacceptable.

After the electroplating solution permeates into the copper terminal electrode, when the capacitor is vibrated, the terminal electrode is easy to warp and fall off, and the reliability of the product is influenced. The inherent characteristics of the copper paste are directly adjusted, so that the process difficulty is high and the production cost is high.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a chip multilayer ceramic capacitor, it can prevent that the end electrode warpage from droing.

The embodiment of the utility model discloses a realize through following technical scheme:

a chip multilayer ceramic capacitor comprises an inner electrode, a ceramic body and end electrodes arranged on two sides of the ceramic body, wherein each end electrode comprises a four-layer laminated structure, and a nickel layer, a copper layer, a nickel layer and a tin-lead layer are respectively arranged from inside to outside.

Furthermore, ceramic body protrusions are fixedly arranged at the top and the bottom of the ceramic body, and the end parts of the tin-lead layers are tightly attached to the ceramic body protrusions.

Furthermore, a plurality of heat dissipation strips are fixedly arranged on the ceramic body protrusion.

Furthermore, the heat dissipation strip is insulating heat conduction silica gel material.

And the bottom end of the terminal electrode is fixedly connected with the shell, and one side of the terminal electrode, which is far away from the ceramic body, is connected with the shell through a spring.

Further, the top of the terminal electrode is connected with the shell through a spring.

Further, the housing is an insulating material.

The utility model discloses technical scheme has following advantage and beneficial effect at least:

the utility model provides a chip multilayer ceramic capacitor, the end electrode is nickel layer, copper layer, nickel layer, tin lead layer from inside to outside respectively, has replaced the three-layer structure of copper layer, nickel layer, tin lead layer among the prior art, adds a layer of nickel layer in the copper layer again, prevents that nickel or acid plating solution from infiltrating into the copper electrode and leading to the phenomenon that the end electrode warpage drops;

because the nickel has better compactness, the nickel or the acid electroplating solution for subsequent electroplating can be prevented from entering the interface between the terminal electrode and the ceramic body, thereby ensuring the connection tightness between the terminal electrode and the ceramic body and improving the reliability of the product;

meanwhile, the nickel electrode can be co-fired with the ceramic body, so that the connection between the ceramic body and the terminal electrode is tighter.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic view of Ni infiltration;

fig. 2 is a cross-sectional view of a chip multilayer ceramic capacitor provided in embodiment 1 of the present invention;

fig. 3 is a cross-sectional view of a chip multilayer ceramic capacitor provided in embodiment 2 of the present invention;

fig. 4 is a schematic structural diagram of a chip multilayer ceramic capacitor provided in embodiment 2 of the present invention.

Icon:

10-ceramic body, 11-internal electrode, 20-terminal electrode, 21-nickel layer, 22-copper layer, 23-tin-lead layer, 30-ceramic body protrusion, 40-heat dissipation strip, 50-shell and 60-spring.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Example 1

As shown in fig. 2, the present embodiment provides a chip multilayer ceramic capacitor, which includes an inner electrode 11, a ceramic body 10, and terminal electrodes 20 disposed on two sides of the ceramic body 10, wherein the terminal electrodes 20 include four layered structures, and a nickel layer 21, a copper layer 22, a nickel layer 21, and a tin-lead layer 23 from inside to outside.

The terminal electrode 20 is respectively a nickel layer 21, a copper layer 22, a nickel layer 21 and a tin-lead layer 23 from inside to outside, the three-layer structure of the copper layer 22, the nickel layer 21 and the tin-lead layer 23 in the prior art is replaced, and the nickel layer 21 is added in the copper layer 22 to prevent the phenomenon that the terminal electrode 20 is warped and falls off due to the fact that nickel or acid electroplating solution permeates into the copper electrode. Because nickel has better compactness, the nickel or acid electroplating solution for subsequent electroplating can be prevented from entering the interface between the terminal electrode 20 and the ceramic body 10, so that the tightness of the connection between the terminal electrode 20 and the ceramic body 10 is ensured, and the reliability of the product is improved.

Example 2

As shown in fig. 3 to 4, the present embodiment provides a chip multilayer ceramic capacitor, which includes an inner electrode 11, a ceramic body 10, and terminal electrodes 20 disposed on two sides of the ceramic body 10, wherein the terminal electrodes 20 include four layered structures, and a nickel layer 21, a copper layer 22, a nickel layer 21, and a tin-lead layer 23 from inside to outside.

In this embodiment, the ceramic body protrusions 30 are fixedly disposed on the top and bottom of the ceramic body 10, and the ends of the tin-lead layer 23 are closely attached to the ceramic body protrusions 30. In the preparation process, the tin-lead layer 23 is firstly coated on the outer side of the terminal electrode 20, and then the ceramic body bulge 30 is sintered on the ceramic body 10 at the end part of the tin-lead layer 23, so that the edge of the tin-lead layer 23 is fixed by the ceramic body bulge 30, and the phenomenon that the edge is warped and falls off to influence the working effect of the capacitor is avoided.

In this embodiment, a plurality of heat dissipation bars 40 are fixedly disposed on the ceram protrusions 30. In the working process of the chip type multilayer ceramic capacitor, the situation that the working effect is influenced by overhigh temperature can occur, in order to help the ceramic capacitor to dissipate heat, a plurality of heat dissipation strips 40 are fixed on the ceramic protrusion 30, the area in contact with air is increased, heat dissipation is facilitated, and overhigh temperature of the ceramic capacitor is avoided.

In this embodiment, the heat dissipation strip 40 is made of an insulating and heat-conducting silica gel material. The heat dissipation strip 40 is selected to be made of an insulating material, normal work of the capacitor is prevented from being influenced, the heat conduction material is favorable for accelerating the heat dissipation speed, and silica gel is a suitable material.

In this embodiment, the terminal electrode further includes a housing 50, a bottom end of the terminal electrode 20 is fixedly connected to the housing 50, and a side of the terminal electrode 20 away from the ceramic body 10 is connected to the housing 50 through a spring 60. Can protect ceramic capacitor better through the design of shell 50, set up spring 60 in the terminal electrode 20 outside, in the scene of vibration, chip type multilayer ceramic capacitor can obtain fine protection, avoids terminal electrode 20 to bump and leads to the metal level warpage to drop.

In this embodiment, the top of the terminal electrode 20 is connected to the housing 50 by a spring 60. The spring 60 connection is also added on the top, so that the ceramic capacitor can be further protected from collision.

In this embodiment, the housing 50 is an insulating material.

In summary, in the chip multilayer ceramic capacitor provided by this embodiment, the inner layer of the terminal electrode is a dense nickel layer, which can prevent the terminal electrode from warping and falling off due to the permeation of electroplating solution into the terminal electrode, and thus the reliability of the ceramic capacitor is affected; the heat dissipation of the ceramic capacitor can be accelerated, and the ceramic capacitor is prevented from being overhigh in temperature.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The chip type multilayer ceramic capacitor is characterized by comprising an inner electrode (11), a ceramic body (10) and end electrodes (20) arranged on two sides of the ceramic body (10), wherein the end electrodes (20) comprise four layers of layered structures, namely a nickel layer (21), a copper layer (22), a nickel layer (21) and a tin-lead layer (23) from inside to outside.

2. The chip multilayer ceramic capacitor according to claim 1, wherein ceramic bumps (30) are fixedly provided on the top and bottom of the ceramic body (10), and the ends of the tin-lead layer (23) are closely attached to the ceramic bumps (30).

3. The chip multilayer ceramic capacitor according to claim 2, wherein a plurality of heat dissipation bars (40) are fixedly provided on the ceramer protrusions (30).

4. The chip multilayer ceramic capacitor according to claim 3, wherein the heat dissipation bars (40) are made of insulating and heat-conducting silicone.

5. The chip multilayer ceramic capacitor according to claim 1, further comprising a housing (50), wherein the bottom end of the terminal electrode (20) is fixedly connected to the housing (50), and the side of the terminal electrode (20) away from the ceramic body (10) is connected to the housing (50) by a spring (60).

6. The chip multilayer ceramic capacitor according to claim 5, wherein the top of the terminal electrode (20) is connected to the case (50) by a spring (60).

7. The chip multilayer ceramic capacitor according to claim 5, wherein the case (50) is an insulating material.