LED Package Wiring via Laser-Ablated Metal Paste
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Solution Overview
Problem
Existing methods for manufacturing light-emitting devices are inefficient and prone to short-circuiting due to the complexity and cost of forming metal layers using sputtering or vapor deposition, and the need for thick metal layers which can break easily.
Innovation Solution
A method involving a metal paste layer made of a mixture of resin and metal powder, where laser ablation is used to remove the metal paste layer between electrodes, forming wirings and preventing short-circuits, allowing for precise and efficient formation of paired wirings without the need for sophisticated equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sputtering or vapor deposition is used to form metal layers, then electrical conductivity is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent replaces complex vacuum deposition equipment (sputtering or vapor deposition) with a simple screen printing process. The metal paste is printed through a screen onto the substrate, eliminating the need for sophisticated vacuum chambers and deposition machinery while achieving sufficient electrical conductivity for the wiring layers.
Solution Approach 2:
The patent uses a disposable screen printing mask instead of expensive, complex deposition equipment. The screen can be discarded after use, and the process requires no expensive vacuum systems or specialized deposition tools, significantly reducing manufacturing complexity and cost.
2Reliability
If thick metal layers are used to prevent short-circuits, then reliability is improved, but the metal layers become more prone to breaking
Solution Approach 1:
The patent uses a composite metal paste material containing metal particles (for conductivity), glass powder (for adhesion and flexibility), and organic vehicle (for screen printing). This composite formulation creates wirings that are sufficiently thick to prevent short-circuits but flexible enough to resist breaking, combining the benefits of thickness with improved mechanical strength.
Solution Approach 2:
The patent changes the physical and chemical parameters of the metal layer by using metal paste with controlled particle size distribution, glass content, and organic binders. These parameter changes allow the formation of wirings with optimal thickness that prevent short-circuits while maintaining flexibility and resistance to breakage.
3Manufacturing precision
If laser ablation is used to remove metal paste between electrodes, then manufacturing precision is improved, but processing time increases
Solution Approach 1:
The patent performs preliminary action by applying a thick metal paste layer that automatically bridges gaps between electrodes during screen printing. The excess metal paste between electrodes is then removed by laser ablation, but the preliminary formation of continuous metal paths ensures that even if some removal occurs, electrical connectivity is maintained while achieving precise wiring patterns.
Solution Approach 2:
The patent replaces mechanical machining or photoresist-based patterning methods with laser ablation. The laser directly removes metal paste with high precision without requiring masks or mechanical tooling, achieving accurate wiring patterns while maintaining relatively fast processing speeds suitable for manufacturing.
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 improves working efficiency, reduces the risk of wiring breakage, and enables the creation of smaller, reliable light-emitting devices with enhanced electrical conductivity and reduced electric resistance.
Implementation Method 1
The paired wirings are formed by irradiation of laser light on a metal paste layer continuously covering the paired electrodes and the first covering member to remove the metal paste layer between the paired electrodes
Data Source
AI summary
A light-emitting device comprising a package comprising a light-emitting element comprising a first surface and a second surface opposite to the first surface, a first light-transmissive member arranged on the second surface of the light-emitting element, paired electrodes at the first surface of the light-emitting element, and a first covering member covering the light-emitting element such that the paired electrodes are exposed from the first covering member. The light-emitting device further comprises a light-guiding plate on which the package is placed, and a second covering member arranged on the light-guiding plate and covering laterally the package. The light-emitting device further comprises paired wirings continuously covering the paired electrodes exposed and the first covering members and being connected to the paired electrodes respectively. The paired wirings are formed by irradiation of laser light on a metal paste layer continuously covering the paired electrodes and the first covering member to remove the metal paste layer between the paired electrodes, the metal paste layer comprising a mixture of a resin and metal powder.