Wiring Board Notch Segmentation for Positioning Accuracy

Solution Overview

Problem

Existing wiring board connection structures face challenges in maintaining precise positioning and reliable contact between components with different thermal expansion coefficients, leading to positional deviations and erroneous contacts during soldering.

Innovation Solution

A wiring board design featuring a substrate with notches between electrode groups and the use of anisotropic conductive paste, which self-aligns and grows solder to connect electrodes, absorbing thermal expansion variations through notches to maintain accurate positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If flexible printed circuit boards with narrow electrode pitches are used to reduce size, then miniaturization is achieved, but positional deviations and erroneous contacts occur during soldering due to thermal expansion differences

Engineering Contradiction:

Improvesize of wiring boardVSAvoidpositioning accuracy of electrodes

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The substrate is divided into multiple rigid sections by introducing notches between electrode groups. This segmentation allows each section to independently manage thermal expansion while maintaining overall flexibility, preventing positional deviations between electrodes during soldering processes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The anisotropic conductive paste serves as an intermediary material between the rigid substrate and flexible printed circuit board. It absorbs dimensional variations through its self-aligning properties and provides reliable electrical connection despite thermal expansion differences, eliminating erroneous contacts.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If rigid substrates are used to maintain positioning accuracy, then manufacturing precision is improved, but flexibility and adaptability are reduced

Engineering Contradiction:

Improvepositioning accuracy of electrodesVSAvoidflexibility of wiring board

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The substrate is divided into multiple rigid sections by introducing notches between electrode groups. This segmentation allows each section to independently manage thermal expansion while maintaining overall flexibility, preventing positional deviations between electrodes during soldering processes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The wiring board combines rigid substrate sections with flexible printed circuit boards using anisotropic conductive paste. This composite structure maintains positioning accuracy where needed while preserving flexibility in other areas, achieving both precision and adaptability.

Inventive Principle:

Principle #40Composite materials

3Device complexity

If thermal expansion differences are not compensated, then device complexity is reduced, but reliability of solder connections deteriorates

Engineering Contradiction:

Improvestructure complexityVSAvoidconnection reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The substrate is divided into multiple rigid sections by introducing notches between electrode groups. This segmentation allows each section to independently manage thermal expansion while maintaining overall flexibility, preventing positional deviations between electrodes during soldering processes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The anisotropic conductive paste serves as an intermediary material between the rigid substrate and flexible printed circuit board. It absorbs dimensional variations through its self-aligning properties and provides reliable electrical connection despite thermal expansion differences, eliminating erroneous contacts.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution effectively suppresses positional deviations caused by thermal expansion differences, ensuring reliable and precise connections between components with different materials, even under varying temperatures.

Implementation Method 1

differences in thermal expansion coefficients, leading to positional deviations and erroneous contacts during soldering

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

anisotropic conductive paste that self-aligns and grows solder connections

Methodology Applied

Scientific EffectSelf-alignment: Self-Assembly

Data Source

PatentUS10194531B2Wiring board and connection structure

Publication Date: 2019.01.29 FUJIFILM BUSINESS INNOVATION CORP

AI summary

Provided is a wiring board including a substrate formed of an insulation material, and plural conductive patterns including plural electrodes arranged on a surface of the substrate along an end surface of the substrate, and plural wiring patterns connected to the plural electrodes, respectively, wherein the substrate includes a notch formed between electrode groups each of which includes a predetermined number of the electrodes.