Flexible Electrical Connection Structure for Low-Height Repairable Assembly

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Solution Overview

Problem

Existing electrical connection methods in electronic devices are limited by their permanent nature, making repairs and component replacements difficult, and they often compromise on reliability, space-saving, and cost due to high connection heights and limited pitch options.

Innovation Solution

A flexible electrical connection structure featuring a first connecting member with a conductive pad and through-hole, and a second connecting member with a conductive projection, allowing for detachable connections with a height of 0.5 mm or less, utilizing a grid-like array arrangement for increased reliability and space efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If ACF connection method is used, then height of connection structure is reduced to 100 μm or less, but connection reliability is low and large current cannot flow

Engineering Contradiction:
Improveheight of connection structureVSAvoidconnection reliability
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The invention changes the physical parameters of the connection structure by using a recessed pad design where the pad surface is lower than the substrate surface. This allows the conductive projection to insert deeply into the recess, creating a low-profile connection (100 μm or less height) while maintaining reliable electrical contact through the elastic deformation of the pad material during insertion and connection.

Inventive Principle:
Principle #35Parameter changes

2Ease of repair

If connector structure with male and female connectors is used, then connecting members can be attached and detached repeatedly, but height of connection structure cannot be reduced

Engineering Contradiction:
Improverepeatability of connectionVSAvoidheight of connection structure
Core Design Contradiction:
Ease of repairVSLength of stationary object

Solution Approach 1:

The invention segments the connection structure into a substrate with recessed pads and a separate component with conductive projections. This segmentation allows the component to be detached and reattached multiple times (improving ease of repair) while the recessed pad design keeps the overall connection height minimal (100 μm or less), resolving the contradiction between repeatability and height reduction.

Inventive Principle:
Principle #1Segmentation

3Length of stationary object

If pitch between pads is narrowed to 40 μm or so, then height of connection structure is reduced, but connection reliability is low and noise level is high

Engineering Contradiction:
Improveheight of connection structureVSAvoidnoise level
Core Design Contradiction:
Length of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The invention uses a nested structure where the conductive projection inserts into a recess formed within the substrate surface, creating a multi-level nested arrangement. This nesting allows the connection height to be reduced to 100 μm or less while the recessed design provides better shielding and lower inductance, reducing noise levels even at narrow pitch intervals of 40 μm or less.

Inventive Principle:
Principle #7Nested doll (Nesting)

4Ease of repair

If conventional connector structure is used, then connecting members can be detached and attached repeatedly, but fine connectors with high accuracy are difficult to produce

Engineering Contradiction:
Improverepeatability of connectionVSAvoidaccuracy of connector
Core Design Contradiction:
Ease of repairVSManufacturing precision

Solution Approach 1:

The invention uses a flexible pad structure made of elastic material that forms the female connector portion on the substrate. This flexible thin-film approach allows for the formation of fine, high-precision connectors with narrow pitch (40 μm or less) that can still accommodate repeated insertion and detachment operations, resolving the contradiction between manufacturing precision and ease of repair.

Inventive Principle:
Principle #30Flexible shells and thin films

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 enables reliable, repeatable connections with low contact resistance and high mechanical strength, facilitating easy repair and replacement of components while achieving significant space-saving and cost-effectiveness in electronic devices.

Implementation Method 1

a conductive projection formed on a surface of a counterpart to function as a male terminal, into an elastic female terminal, formed to a first connecting member formed of a thin flexible insulating film, and a pad constituting the female terminal is formed of an elastic material

Methodology Applied
Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 2

a pad constituting the female terminal is formed of an elastic material

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2117082B1Electrical connection structure
Publication Date: 2016.05.18 ASAHI DENKA KENKYUSHO
  • EP2117082B1 patent drawingFigure 1~2
  • EP2117082B1 patent drawingFigure 3~4
  • EP2117082B1 patent drawingFigure 5~6

AI summary

An electrical connection structure allowing reduction in height and easy disassembly, wherein a first connecting member comprises a flexible substrate comprising a flexible insulating film, at least one conductive pad formed on at least one side thereof, a conductive circuit pattern extending from the rim of the pad, a through-hole formed through the thickness thereof at a planar position within the pad, and a small aperture formed at a planar position within the pad and communicating with the through-hole, and a second connecting member comprises a conductive projection formed at least one side thereof and electrically connected with a conductive circuit pattern formed inside or on the second connecting member, where the electrical connection is formed in the manner such that the conductive projection is inserted in the through-hole, through the small aperture, and mechanically contacts the pad.