Screen-Printing Mask Layout for Variable-Thickness Conductive Glazing
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Solution Overview
Problem
Current screen printing technologies require multiple steps and significant investment to achieve varying thicknesses of electrically conductive patterns on motor-vehicle glazings, particularly in central portions, to meet stringent temperature cycling tests, which is inefficient and costly.
Innovation Solution
A screen printing screen with a main mask and a secondary mask, where the secondary mask is bonded to the main mask at an angle, allowing for thicker patterns to be printed in central portions in a single pass by varying the aperture sizes and wire density, enabling thicker conductive tracks where needed, such as soldering zones, while maintaining thinner tracks elsewhere.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple screen-printing operations are performed to obtain thicker patterns in central portions, then the thickness requirement is met, but production complexity and cost increase
Solution Approach 1:
The screen is divided into multiple zones with different aperture characteristics: central portions with larger apertures for thicker patterns, lateral portions with smaller apertures for thinner patterns, and transition zones with intermediate apertures. This segmentation allows a single printing operation to produce variable thickness patterns across different regions of the glazing.
Solution Approach 2:
Each zone of the screen is designed with locally optimized aperture size to match the specific thickness requirements of that region. The central portion uses larger apertures to deposit thicker paste for soldering zones, while lateral portions use smaller apertures for thinner conductive tracks, eliminating the need for multiple printing passes.
2Manufacturing precision
If variable aperture masks are used to obtain different thicknesses in lateral portions, then thickness variation is achieved, but central portion patterns remain uniformly thin
Solution Approach 1:
The screen aperture distribution is segmented into distinct zones: central portions with larger apertures, lateral portions with smaller apertures, and transition zones with intermediate apertures. This segmentation enables each zone to independently control paste deposition thickness according to its specific requirements.
Solution Approach 2:
The invention extends the variable aperture concept from one-dimensional lateral variation to two-dimensional spatial distribution across the entire screen surface. Aperture size now varies in both lateral and central dimensions, allowing independent optimization of thickness in any region of the glazing.
3Reliability
If thicker patterns are printed in central portions, then temperature cycling test requirements are met, but visibility of the glazing decreases
Solution Approach 1:
Thicker conductive patterns are deposited only in central portions where soldering and connection functions are required, while lateral portions maintain thinner patterns that preserve glazing visibility. This local differentiation ensures reliability where needed without compromising optical performance in visible areas.
Solution Approach 2:
The screen uses aperture size as a template to control paste deposition thickness. Larger apertures in central zones create thicker patterns for functional requirements, while smaller apertures in lateral zones create thinner patterns for aesthetic requirements, all in a single printing operation.
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 allows for the production of glazings with electrically conductive patterns of varying thicknesses in a single screen-printing pass, meeting the requirements of temperature cycling tests without the need for additional equipment or processes, thereby reducing costs and improving efficiency.
Implementation Method 1
using a photocrosslinkable emulsion to block apertures
Implementation Method 2
secondary mask fastened to a face of said main mask
Data Source
AI summary
A screen-printing screen for printing electrically conductive patterns on glass sheets, includes a main mask, the aperture size of the main mask being larger in a lateral portion than in the central portion, the screen furthermore including, in at least one double-mask zone, located in the central portion, at least one secondary mask fastened to a face of the main mask, the aperture size of the or each secondary mask being larger than the aperture size of the main mask in the central portion, and the mesh of the or each secondary mask making, with the mesh of the main mask, an angle α comprised between 1 and 89°.