Wiring Board Reinforcement Layer for Stress Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Electronic device modules face stress concentration issues due to differences in thermal expansion rates and rigidity characteristics between components, leading to potential damage to wiring in electronic apparatuses like HDDs during thermal expansion or mechanical stress.

Innovation Solution

Incorporating a reinforcement layer, such as a conductive ground layer, between components and attaching a support plate with higher thermal expansion rate than the wiring board, which reduces stress on the wiring by distributing it across wider areas and reducing the difference in rigidity characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a reinforcement layer is added to reduce stress concentration on wiring, then wiring durability is improved, but device complexity increases

Engineering Contradiction:

Improvewiring durabilityVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the reinforcement layer with the ground layer, making the ground layer serve dual purposes: electrical grounding and mechanical reinforcement. This eliminates the need for a separate reinforcement structure, thereby improving wiring durability without increasing device complexity

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The ground layer is designed to perform multiple functions simultaneously: providing electrical reference potential and acting as a structural reinforcement element. This multi-functionality resolves the contradiction by achieving wiring protection without adding extra components

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Stress or pressure

If the support plate has higher thermal expansion rate than the wiring board, then stress on wiring is reduced, but thermal management becomes more challenging

Engineering Contradiction:

Improvewiring stressVSAvoidthermal management

Core Design Contradiction:

Stress or pressureVSTemperature

Solution Approach 1:

The patent selects materials for the support plate with specific thermal expansion properties that differ from the wiring board. By carefully choosing materials with higher thermal expansion rates, the design compensates for stress concentration during thermal cycles, reducing wiring stress while managing thermal effects through material selection

Inventive Principle:

Principle #35Parameter changes

3Reliability

If additional reinforcing members are added to protect wiring, then wiring protection is improved, but manufacturing cost increases

Engineering Contradiction:

Improvewiring protectionVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines the ground layer and reinforcement function into a single integrated structure. By making the ground layer serve as the reinforcement element, the design eliminates the need for additional reinforcing members, thereby protecting wiring without increasing manufacturing cost

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The ground layer is designed to perform multiple functions simultaneously: providing electrical grounding and acting as a structural reinforcement element. This multi-functionality resolves the contradiction by achieving wiring protection without adding extra components that would increase manufacturing cost

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

The reinforcement layer effectively reduces stress concentration on the wiring, preventing damage and enhancing the durability of the electronic device module without increasing manufacturing costs by eliminating the need for additional reinforcing members.

Implementation Method 1

attaching a support plate with higher thermal expansion rate than the wiring board, which reduces stress on the wiring by distributing it across wider areas and reducing the difference in rigidity characteristics

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS9538661B2Electronic device module including a printed circuit

Publication Date: 2017.01.03 KK TOSHIBA

AI summary

An electronic device module includes a wiring board having a first surface including first and second electrodes formed thereon and a second surface opposite to the first surface, a supporting member attached to the second surface of the wiring board, a first electronic unit mounted on the first surface of the wiring board and electrically connected to the first electrode, and a second electronic unit mounted on the first surface of the wiring board and electrically connected to the second electrode. The wiring board includes a wiring extending from the first electronic unit to a position closer to the second electronic unit, and a reinforcement layer disposed between the first and second electronic units and apart from the wiring in a thickness direction of the wiring board.