Flexible PCB Guard Pattern for Print Head Ink Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing solutions for preventing ink penetration into flexible printed circuit boards in print heads, such as reinforcement plates or sealing materials, compromise the flexibility of the circuit boards and are not effective when components like capacitors are mounted, leading to potential short circuits and damage.
Innovation Solution
A flexible printed circuit board design with a guard pattern and wiring part configuration, where the side parts include low-potential ground wiring and signal lines that can detect ink penetration without new configurations, allowing for the regulation of ink penetration and monitoring of signal values, thereby preventing short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a reinforcement plate or sealing material is used to prevent ink penetration, then the reliability of the flexible printed circuit board is improved, but the flexibility of the circuit board deteriorates
Solution Approach 1:
The patent applies different properties to different parts of the flexible printed circuit board. Specifically, the side part includes low-potential ground wiring and signal lines that are not covered by ink-resistant resin, creating a protective barrier only where needed (near high-potential wiring) while leaving other areas flexible and accessible for component mounting and signal transmission.
Solution Approach 2:
The patent introduces an intermediary structure (ink-resistant resin covering) that mediates between the high-potential wiring and the ink environment. This intermediary layer prevents direct contact between ink and critical wiring, providing protection without requiring a complete sealing approach that would compromise flexibility.
2Reliability
If the entire side part is sealed to prevent ink penetration, then the reliability is improved, but the ease of manufacture deteriorates due to inability to mount components
Solution Approach 1:
The ink-resistant resin covering is applied selectively only to the side part of the flexible printed circuit board, not to the entire board. This localized application protects critical areas from ink penetration while leaving other areas accessible for mounting electronic components such as capacitors, maintaining ease of manufacture.
3Measurement precision
If low-potential ground wiring and signal lines are positioned near high-potential wiring, then the ability to detect ink penetration is improved, but the risk of short circuit increases
Solution Approach 1:
The patent implements a feedback mechanism where low-potential ground wiring and signal lines positioned near high-potential wiring serve as sensors. When ink penetrates and causes a short circuit, the change in electrical characteristics of these nearby lines provides feedback that enables detection of the ink penetration event, allowing for timely response before catastrophic damage occurs.
Data Source
AI summary
A flexible printed circuit board whose end part side is connected to a print element substrate capable of ejecting ink using a print element, so as to be capable of transmitting a signal from a control part of a printing apparatus to the print element substrate via wiring and to be capable of transmitting a signal from the print element substrate to the control part via the wiring, wherein a side part side of high-potential wiring includes at least one of a regulation part that regulates penetration of ink and a wiring part that is configured with low-potential ground wiring and low-potential liquid signal line whose signal value transmitted by the control part or operation based on a signal is monitored.