Piezoelectric Reflecting Layer Printing for Backlight Plates

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Solution Overview

Problem

The existing silk-screen printing process for backlight panel reflecting layers is inaccurate, affecting subsequent processes and increasing costs, with issues such as warping and ink overflow leading to poor accuracy and appearance.

Innovation Solution

A method and device using piezoelectric injection valves for precise control of the reflecting layer thickness, involving correction processing, specification parameter acquisition, and controlled printing paths to ensure accuracy and prevent warping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If silk-screen printing is used to coat the reflecting layer, then the reflecting layer can be formed on the backlight panel, but the printing accuracy is low and it affects subsequent solder paste printing accuracy

Engineering Contradiction:
Improveprinting accuracyVSAvoidsolder paste printing accuracy
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical silk-screen printing system with a piezoelectric injection valve system. The piezoelectric injection valves precisely control the ejection of ink droplets through piezoelectric actuation, enabling accurate positioning and thickness control without the mechanical limitations of screen printing, thereby resolving the accuracy and reliability issues

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the controlling parameter from mechanical screen tension and pressure to piezoelectric voltage control. By adjusting the voltage applied to piezoelectric injection valves, the thickness and position of ink droplets are precisely controlled, achieving high printing accuracy that maintains subsequent solder paste printing accuracy

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multiple silk-screen printings are performed to increase reflecting layer height, then the reflectivity requirement can be met, but ink overflow occurs leading to poor accuracy and appearance

Engineering Contradiction:
Improvereflecting layer heightVSAvoidink overflow
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent uses periodic pulsed ejection of ink droplets through piezoelectric injection valves. Each pulse precisely deposits a controlled amount of ink, and the periodic nature allows for accurate cumulative thickness control without continuous pressure application that causes overflow, achieving required reflecting layer height with clean edges

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent employs pneumatic control through piezoelectric actuation to eject ink droplets. The piezoelectric valves provide precise volumetric control of liquid ejection, allowing accurate thickness accumulation without the uncontrolled flow and overflow problems of conventional multi-pass screen printing

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Ease of manufacture

If silk-screen printing is performed on integrated backlight panel, then the reflecting layer can be coated, but the panel is prone to warping

Engineering Contradiction:
Improvereflecting layer coatingVSAvoidpanel warping
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent replaces the mechanical screen printing process with piezoelectric droplet ejection. This substitution eliminates the mechanical stress and heat generation that cause warping, while still achieving effective reflecting layer coating through precise droplet placement and controlled thickness

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the coating process parameters from mechanical pressure and heat to controlled piezoelectric actuation and droplet ejection. This parameter change eliminates the thermal and mechanical stressors that cause panel warping while maintaining effective coating performance

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

The method and device provide flexible and accurate printing of the reflecting layer, avoiding interference with solder paste accuracy and preventing warping, thus ensuring high preparation precision.

Implementation Method 1

controlling piezoelectric injection valves to achieve a stepless change in the thickness of the reflecting layer

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4307038B1Printing method and apparatus for reflecting layer of backlight plate
Publication Date: 2025.09.10 ENOVATE3D (HANGZHOU) TECH DEV CO LTD
  • EP4307038B1 patent drawingFigure 1~2
  • EP4307038B1 patent drawingFigure 3
  • EP4307038B1 patent drawingFigure 4

AI summary

The embodiment of the present application provides a method and device for printing a reflecting layer of a backlight panel. The method includes performing first correction processing on at least two piezoelectric injection valves firstly, then acquiring specification parameters of the backlight panel, generating moving paths of the at least two piezoelectric injection valves according to the specification parameters of the backlight panel, and controlling the corrected piezoelectric injection valves to print according to the moving paths. The reflecting layer is printed by controlling the piezoelectric injection valves to achieve stepless change in the film thickness of the reflecting layer, and the method can be implemented before or after the die bonding process. Compared with the conventional silk-screen printing method, the method is more flexible, which can not only avoid influence on the solder paste printing accuracy of the backlight panel, but also prevent the cured reflecting layer from warping, so as to ensure the preparation accuracy of the reflecting layer.