Wiring Substrate Recessed Adhesive Section for Droplet Ejection Head

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing droplet ejection heads face issues with wire migration and short circuits due to the presence of conductive substances in the adhesive, leading to potential electrical failures in the wiring substrates used in printing apparatuses.

Innovation Solution

The implementation of a wiring substrate design with recessed sections in the adhesive between wires, which increases the inter-wire length and prevents contact between conductive wires and the adhesive, thereby reducing migration and short circuits. This design includes a sacrificial film to separate wires from the adhesive, and the use of non-conductive adhesives to further mitigate these issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wires are set on the adhesive surface to connect substrates, then electrical connection is achieved, but wire migration and short circuits occur due to contact with conductive substances in the adhesive

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidwire migration and short circuit

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A recessed section is formed in the adhesive layer between adjacent wires, creating a physical barrier that prevents wire migration and short circuits. The recessed section acts as an intermediary structure that maintains electrical connection while eliminating the harmful contact between wires and conductive adhesive substances.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The adhesive layer is segmented into different regions: areas where wires are bonded and a recessed section where wires are separated. This segmentation prevents continuous contact between wires and adhesive, reducing migration while maintaining necessary electrical connections.

Inventive Principle:

Principle #1Segmentation

2Length of stationary object

If the adhesive layer is made thin to reduce overall device thickness, then device compactness is improved, but wire migration risk increases due to reduced separation distance

Engineering Contradiction:

Improveadhesive layer thicknessVSAvoidwire migration prevention

Core Design Contradiction:

Length of stationary objectVSReliability

Solution Approach 1:

Instead of increasing adhesive layer thickness in the vertical dimension to prevent wire migration, the solution creates a recessed section that introduces a horizontal dimension separation. This allows the adhesive layer to remain thin overall while providing sufficient wire separation through the recessed geometry.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS9321261B2Wiring substrate, droplet ejection head, printing apparatus, electronic device, and manufacturing method for wiring substrate

Publication Date: 2016.04.26 SEIKO EPSON CORP

AI summary

A wiring substrate includes a device substrate having a first surface, a sealing plate having a second surface superimposed on the first surface via an adhesive film and crossing the first surface, and wires set along the surfaces of the first surface, the adhesive film, and the second surface. The wiring substrate includes, between the wires adjacent to each other, a recessed section forming a recess with respect to a first bonding surface of the adhesive which is in contact with the first wire and a second bonding surface of the adhesive which is in contact with the second wire.