Liquid Ejection Head Wiring Substrate Inclination Clearance

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Solution Overview

Problem

The existing techniques for connecting a terminal on a substrate and a wiring portion of a wiring substrate in liquid ejection heads are prone to electrical connection failures due to unintentional inclinations of the wiring substrate, leading to improper contact areas.

Innovation Solution

The proposed solution involves designing a liquid ejection head where the electrical connection section of the wiring substrate has a non-connection range with an inclined portion, maintaining a significant clearance from the actuator substrate even when the wiring substrate inclines unintentionally, thereby preventing electrical contact failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the wiring substrate is placed close to the element substrate for direct connection, then productivity improves by eliminating wire arrangement operations, but reliability deteriorates due to unintentional contact between non-connection areas and the element substrate

Engineering Contradiction:
ImproveproductivityVSAvoidreliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The wiring substrate is divided into a connection range (where electrical connection occurs) and a non-connection range (where no connection is intended). This segmentation allows the non-connection range to be positioned away from the element substrate, preventing unwanted contact while maintaining the productivity benefits of direct connection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent positions the non-connection range of the wiring substrate at a different spatial location relative to the element substrate, creating vertical or lateral clearance. This dimensional separation prevents unintended contact between non-connection areas and the element substrate while maintaining efficient connection at the designated connection range.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If the wiring substrate inclines unintentionally during connection, then manufacturing simplicity is maintained, but connection precision deteriorates due to improper contact areas

Engineering Contradiction:
Improveease of manufactureVSAvoidconnection precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent designs the wiring substrate with the non-connection range positioned to create a buffer zone or clearance area. This beforehand cushioning ensures that even if inclination occurs during manufacturing, the non-connection range will not contact the element substrate, protecting connection precision without requiring complex manufacturing controls.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP4545305A1Liquid ejection head, liquid ejection apparatus, and manufacturing method of liquid ejection head
Publication Date: 2025.04.30 CANON KK
  • EP4545305A1 patent drawingFigure 1
  • EP4545305A1 patent drawingFigure 2
  • EP4545305A1 patent drawingFigure 3

AI summary

An object is to provide a liquid ejection head (103) capable of improving reliability of the connection section (402) between an element substrate (301) and an electrical wiring substrate (302). The liquid ejection head (103) ejecting liquid includes an element substrate (301) having a terminal (401) and a wiring substrate (302) including a wiring portion (605) connected to the terminal (401) in contact therewith. In a direction perpendicular to a surface on which the terminal (401) is provided on the element substrate (301), a second distance (702) between the end portion of the element substrate (301) and the wiring portion (605) is greater than a first distance (701) between the surface on which the terminal (401) is provided and a portion opposite to the terminal (401) of the wiring portion (605).