Liquid Discharge Head Compatible Layer Thickness Control

Solution Overview

Problem

Conventional liquid discharge head manufacturing methods face challenges in achieving uniform thickness of the compatible layer formed by the intermingling of a coated resin layer and a mold member, leading to inconsistencies in flow path formation and ink re-filling speed.

Innovation Solution

A method involving the formation of a mold using positive photosensitive resin, application of a coated layer with epoxy resin and solvent, solvent removal at normal temperature to reduce weight by 7%, followed by curing and depressurization to achieve uniform layer thickness, and subsequent removal of the mold to form flow paths with high accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the wafer-shaped substrate grows in size, then the production capacity increases, but the dispersion of the compatible layer thickness becomes larger

Engineering Contradiction:

Improveproduction capacityVSAvoidcompatible layer thickness uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by removing the solvent from the coated resin layer before the curing process. This preliminary solvent removal prevents the solvent from causing expansion and thickness variation during curing, thereby maintaining uniform compatible layer thickness even on large-scale wafers. The process explicitly states that solvent removal is performed prior to curing to avoid thickness dispersion.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If the solvent is removed under depressurized condition only, then the solvent removal is efficient, but the compatible layer thickness becomes non-uniform on large wafers

Engineering Contradiction:

Improvesolvent removal efficiencyVSAvoidcompatible layer thickness uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent segments the solvent removal process into two distinct stages: first removing solvent under depressurized conditions, then removing remaining solvent under heated conditions. This segmentation allows each stage to optimize for its specific purpose - rapid initial removal followed by complete removal - thereby achieving both efficiency and uniformity in compatible layer thickness across the wafer.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the parameters of the solvent removal process by transitioning from depressurized conditions to heated conditions. This parameter change enables complete solvent removal that maintains uniform compatible layer thickness, as the heating process ensures thorough evaporation without causing the thickness variations that would result from depressurized removal alone.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If the compatible layer thickness varies, then the flow path formation accuracy decreases, but the manufacturing process remains simple

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidflow path formation accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by removing the solvent from the coated resin layer before the curing process. This preliminary solvent removal prevents the solvent from causing expansion and thickness variation during curing, thereby maintaining uniform compatible layer thickness even on large-scale wafers. The process explicitly states that solvent removal is performed prior to curing to avoid thickness dispersion.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameters of the solvent removal process by transitioning from depressurized conditions to heated conditions. This parameter change enables complete solvent removal that maintains uniform compatible layer thickness, as the heating process ensures thorough evaporation without causing the thickness variations that would result from depressurized removal alone.

Inventive Principle:

Principle #35Parameter changes

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

This approach results in a consistent and thin compatible layer, enabling precise flow path formation and maintaining a constant ink re-filling speed across multiple liquid discharge heads.

Implementation Method 1

forming a mold of the flow path made of a positive photosensitive resin on a substrate

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

removing the solvent from the coated layer at a normal temperature under substantially 1 atm

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 3

curing the coated layer

Methodology Applied

Scientific EffectCuring: Photopolymerisation

Data Source

PatentUS8241540B2Method of manufacturing liquid discharge head

Publication Date: 2012.08.14 CANON KK

AI summary

A method of manufacturing a liquid discharge head including a flow path member for forming a flow path communicating with a discharge port discharging a liquid includes forming a mold of the flow path made of a positive photosensitive resin on a substrate; applying a coated layer on the mold for forming the flow path member, which coated layer includes a solvent, an epoxy resin, and a curing agent of the epoxy resin; removing the solvent from the coated layer at a normal temperature under substantially 1 atm. so that the weight of the coated layer may become 93% or less of that thereof at a time of applying of the coated layer, and then further removing the solvent from the coated layer under a depressurized condition; curing the coated layer; and removing the mold to form the flow path.