Insulated Power Module Layout for Narrow Terminal Clearance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In power modules, securing the clearance distance between terminals according to the applied voltage increases the module size, which is undesirable.
Innovation Solution
A power module design with a first insulating portion covering the main surfaces and fastening portions of conductors, and a second insulating portion extending from the terminals, filling the gaps to maintain insulation while minimizing size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a large number of capacitors are mounted in parallel on the same board as the switching element, then the switching element can be cooled effectively, but the device size increases and modularization becomes difficult
Solution Approach 1:
The power conversion device is divided into multiple independent power modules, each containing a switching element and its dedicated cooling capacitor. This segmentation allows each module to be compact while maintaining effective cooling, and enables modular assembly that reduces overall device size compared to mounting all capacitors on a single board.
Solution Approach 2:
A capacitor mounting board is introduced as an intermediary component that couples the switching element and capacitor electrically while allowing thermal connection. This intermediary enables the capacitor to serve as a heat sink for the switching element without requiring direct mounting on the same PCB, thus improving cooling while maintaining compact dimensions.
2Temperature
If a large number of capacitors are mounted in parallel on the same board, then the switching element can be cooled effectively, but the number of parts increases and assembly complexity increases
Solution Approach 1:
By segmenting the power conversion device into multiple identical power modules, the assembly process is simplified through repetition. Each module is a self-contained unit that can be manufactured and tested independently, then assembled in parallel to achieve the required total capacitance, reducing overall assembly complexity compared to mounting individual capacitors on a single board.
Solution Approach 2:
The switching element and capacitor are merged into a single integrated power module unit. This combination reduces the total number of separate components and interconnections required, simplifying both manufacturing and assembly processes while maintaining effective thermal coupling for cooling.
3Reliability
If different types of capacitors are mounted in parallel, then reliability improves through redundancy, but manufacturing precision requirements increase
Solution Approach 1:
Each power module uses capacitors of the same type with identical specifications, ensuring uniform electrical and thermal characteristics. This homogeneity simplifies manufacturing and quality control while still achieving reliability through parallel redundancy of identical modules. The modular approach allows for easier selection and assembly compared to mixing different capacitor types.
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
This design suppresses the increase in module size by narrowing the clearance distance and reducing parasitic inductance, while effectively insulating and canceling magnetic fluxes.
Implementation Method 1
a capacitor that cools the switching element
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A power module of the present disclosure includes a main terminal portion including a first conductor including a P terminal at one end thereof, and a second conductor including an N terminal at one end thereof, connected to a capacitor together with the first conductor, and arranged side by side with the first conductor with a gap interposed therebetween; a circuit board including a power semiconductor element configured to convert a DC voltage from the main terminal portion into an AC voltage; an output terminal portion configured to output an AC voltage from the power semiconductor element; a pair of fastening portions connecting the P terminal and a positive-electrode-side terminal of the capacitor to each other and connecting the N terminal and a negative-electrode-side terminal of the capacitor to each other; a base plate to which the circuit board is fixed; a case fixed to a front surface of the base plate and including an accommodation space accommodating the P terminal, the N terminal, and the pair of fastening portions; and a first insulating portion disposed in the accommodation space and covering a first main surface of the P terminal, a second main surface of the N terminal, and the pair of fastening portions from a side opposite to the base plate, in a state of the gap is filled therewith.