Substrate Terminal Slit Design for Solder Stress Reduction

Solution Overview

Problem

Conventional substrate terminals face issues with high load on solder portions during attachment and detachment, leading to potential deterioration of the electric connection state due to insufficient strength of resin housings or increased size and cost with additional parts.

Innovation Solution

A substrate terminal design featuring a slit between the substrate abutting and connection portions, which disperses the pressing force and reduces stress concentration on the solder portion, allowing for a simple configuration that maintains the electric connection state without additional parts or complex processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the resin housing is made stronger to support pressing force and tensile force, then the reliability improves, but the device complexity and cost increase

Engineering Contradiction:

Improveelectric connection stateVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The substrate terminal body is divided into multiple portions: substrate abutting portion, substrate connection portion, intermediate portion, and terminal connection portion. This segmentation allows each part to bear specific loads independently, protecting the solder portion from excessive stress while maintaining a relatively simple overall structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The intermediate portion acts as a mediator between the substrate connection portion and terminal connection portion. It transmits and distributes forces, preventing direct transmission of tensile and pressing forces to the solder portion, thereby protecting the electric connection state without requiring a complex reinforced housing.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If additional plates are added to receive pressing force and tensile force, then the reliability improves, but the quantity of parts and cost increase

Engineering Contradiction:

Improveelectric connection stateVSAvoidnumber of parts

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The substrate abutting portion, intermediate portion, and substrate connection portion are merged into a single integrated substrate terminal body. This unified structure performs multiple functions (receiving pressing force, transmitting forces, protecting solder joint) without requiring separate plates or additional components, thereby maintaining reliability while reducing part quantity and cost.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The substrate terminal body serves multiple functions simultaneously: it provides mechanical support, distributes applied forces through its segmented structure, protects the solder portion, and maintains electrical connection. This multi-functionality eliminates the need for separate protective plates or housing components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If the substrate terminal structure is simplified, then the device complexity decreases, but the ability to reduce load on solder portion may be compromised

Engineering Contradiction:

Improvestructure complexityVSAvoidelectric connection state

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The substrate terminal body is divided into multiple portions: substrate abutting portion, substrate connection portion, intermediate portion, and terminal connection portion. This segmentation allows each part to bear specific loads independently, protecting the solder portion from excessive stress while maintaining a relatively simple overall structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The intermediate portion acts as a mediator between the substrate connection portion and terminal connection portion. It transmits and distributes forces, preventing direct transmission of tensile and pressing forces to the solder portion, thereby protecting the electric connection state without requiring a complex reinforced housing.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9774118B2Substrate terminal and substrate with terminal

Publication Date: 2017.09.26 YAZAKI CORP

AI summary

A substrate terminal includes at least one substrate abutting portion configured to be made to abut against a substrate, at least one substrate connection portion configured to be inserted into a hole portion in the substrate and be soldered together with the hole portion with the substrate abutting portion and the substrate abutting against each other, a terminal connection portion to which an opposite-side terminal is inserted in a direction same as an insertion direction of the substrate connection portion into the hole portion and connected, and an intermediate portion configured to connect the substrate abutting portion and the substrate connection portion with the terminal connection portion. A slit is provided between the substrate abutting portion and the substrate connection portion adjacent to each other.