Integrated Multilayer Capacitor and Overcurrent Protection Device
Solution Overview
Problem
Existing electronic components with multilayer capacitors face issues with overcurrent flow during short-circuit conditions, leading to potential damage and vibration-induced noise when mounted in electronic devices.
Innovation Solution
Incorporating an overcurrent protection device, such as a PTC thermistor or fuse, in series with the multilayer capacitor and connected via metal terminals, which absorbs electrostrictive vibrations and prevents overcurrent flow by altering resistance or melting upon excessive current, respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a multilayer capacitor is used without an overcurrent protection device, then the device complexity is reduced and manufacturing is simpler, but overcurrent can flow during short-circuit conditions causing damage
Solution Approach 1:
The patent combines the multilayer capacitor and overcurrent protection device into a single integrated component. The capacitor element and protection element are formed together in one body with shared external electrodes, eliminating the need for separate components and reducing overall device complexity while maintaining overcurrent protection functionality.
Solution Approach 2:
The integrated component serves multiple functions simultaneously: energy storage/coupling through the capacitor element and overcurrent protection through the protection element. Both functions are achieved within a single component structure, reducing the number of separate parts needed in the circuit.
2Device complexity
If the multilayer capacitor and overcurrent protection device are integrated into one component, then the device complexity is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The integrated component is divided into distinct functional elements (capacitor element and protection element) with separately formed internal electrodes. This segmentation allows each element to be optimized independently while maintaining precise alignment through the shared external electrode structure and coordinated formation process.
Solution Approach 2:
The external electrodes are formed first on the outer surfaces of the element body, establishing reference points before the internal electrodes are formed. This preliminary action ensures precise alignment of subsequent internal electrode structures, reducing manufacturing precision requirements for the more complex internal features.
3Productivity
If the multilayer capacitor is mounted in electronic devices, then the functionality is achieved, but electrostrictive vibrations cause noise and potential damage
Solution Approach 1:
The integrated protection element acts as an intermediary that absorbs and dampens electrostrictive vibrations generated by the capacitor element. By incorporating the protection element within the same body and using conductive paste connections, vibration energy is dissipated internally rather than being transmitted to mounted electronic devices.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively prevents overcurrent flow and suppresses electrostrictive vibrations, ensuring the electronic component's safety and reducing vibration-induced noise in electronic devices.
Implementation Method 1
the protection circuit element is connected to the third external electrode and the fourth external electrode. A length in the first direction of the second element body is smaller than a length in the first direction of the first element body. The multilayer capacitor and the overcurrent protection device are disposed in such a manner that the side surface on which the electrode portion of the first external electrode is disposed and the side surface of the second element body oppose each other. The electrode portion of the first external electrode and the fourth external electrode are connected to each other, and the connection conductor and the third external electrode are connected to each other.
Implementation Method 2
When voltage is applied to the multilayer capacitor, mechanical strain arises in magnitude depending upon the applied voltage in the first element body due to an electrostrictive effect. The mechanical strain generates vibration of the multilayer capacitor (hereinafter, referred to as electrostrictive vibration).
Implementation Method 3
The first metal terminal includes a first connection portion connected to the electrode portion of the second external electrode, and a first leg portion extending from the first connection portion. The second metal terminal includes a second connection portion connected to the conductor portion of the connection conductor, and a second leg portion extending from the second connection portion.
Data Source
AI summary
A first metal terminal includes a first connection portion connected to an electrode portion of a second external electrode, and a first leg portion extending from the first connection portion. A second metal terminal includes a second connection portion connected to a conductor portion of a connection conductor, and a second leg portion extending from the second connection portion. A multilayer capacitor and an overcurrent protection device are disposed in such a manner that a side surface on which an electrode portion of a first external electrode is disposed and a side surface of a second element body oppose each other. The electrode portion of the first external electrode and a fourth external electrode are connected to each other, and the connection conductor and a third external electrode are connected to each other.