Capacitor Module Bus Bar Anchoring for Heat and Vibration Reliability

Solution Overview

Problem

Capacitor modules experience connection failures due to bus bar movement within the sealing resin caused by thermal shock or vibration, leading to unreliable connections.

Innovation Solution

The capacitor module design includes bus bars with contact and buried portions that feature through holes or protrusions surrounded by sealing resin, preventing separation and enhancing connection reliability by restricting movement perpendicular to these features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the bus bar is exposed outside the sealing resin to accelerate heat dissipation, then heat dissipation performance is improved, but the bus bar moves due to thermal shock or vibration causing connection failure

Engineering Contradiction:

Improveheat dissipation performanceVSAvoidconnection reliability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The bus bar is divided into three distinct segments: a contact portion that contacts the capacitor electrode, a buried portion embedded in the sealing resin, and an exposed portion extending outside the sealing resin. This segmentation allows each portion to fulfill its specific function while maintaining overall connection reliability and heat dissipation performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The buried portion of the bus bar is nested within the sealing resin, with through holes formed in the bus bar that are filled with sealing resin. This nesting structure anchors the bus bar firmly in the sealing resin, preventing movement due to thermal shock or vibration while maintaining electrical connection and heat dissipation.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If the bus bar is completely embedded in the sealing resin to prevent movement, then connection reliability is improved, but heat dissipation performance deteriorates

Engineering Contradiction:

Improveconnection reliabilityVSAvoidheat dissipation performance

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The bus bar is divided into three distinct segments: a contact portion that contacts the capacitor electrode, a buried portion embedded in the sealing resin, and an exposed portion extending outside the sealing resin. This segmentation allows each portion to fulfill its specific function while maintaining overall connection reliability and heat dissipation performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the bus bar have different embedding states: the contact portion is exposed for electrical connection, the buried portion is embedded in the sealing resin for mechanical stability, and the exposed portion is outside the sealing resin for heat dissipation. This local quality differentiation allows the bus bar to simultaneously achieve connection reliability and heat dissipation performance.

Inventive Principle:

Principle #3Local quality

3Temperature

If the bus bar is exposed outside the sealing resin to improve heat dissipation, then temperature control is improved, but the bus bar separates from the sealing resin causing connection failure

Engineering Contradiction:

Improvetemperature controlVSAvoidbus bar position stability

Core Design Contradiction:

TemperatureVSStability of the object's composition

Solution Approach 1:

The bus bar is divided into three distinct segments: a contact portion that contacts the capacitor electrode, a buried portion embedded in the sealing resin, and an exposed portion extending outside the sealing resin. This segmentation allows each portion to fulfill its specific function while maintaining overall connection reliability and heat dissipation performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The buried portion of the bus bar is nested within the sealing resin, with through holes formed in the bus bar that are filled with sealing resin. This nesting structure anchors the bus bar firmly in the sealing resin, preventing movement due to thermal shock or vibration while maintaining electrical connection and heat dissipation.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS20230411079A1Capacitor module

Publication Date: 2023.12.21 MURATA MFG CO LTD

AI summary

A capacitor module that includes: a case defining an interior space; a sealing resin in the interior space; one or more capacitors in the sealing resin; a first bus bar and a second bus bar each having a contact portion that is in contact with an electrode of the one or more capacitors, a buried portion in the sealing resin and extending from the contact portion, and an exposed portion that extends from the first buried portion outside the sealing resin, wherein at least one of the first contact portion, the second contact portion, the first buried portion, and the second buried portion define one or more through holes that are filled with the sealing resin or include one or more protrusions surrounded by the sealing resin.