Dual-Stretch Wafer Segmentation for Isolated LED Arrays
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Solution Overview
Problem
Segmented matrix LEDs face challenges in achieving uniform scene illumination due to color variations and light guiding issues, and wafer level processing that separates light emitters widely increases costs and wastes space, particularly in compact devices like mobile phones.
Innovation Solution
A method involving dual stretching of wafers to create isolated segmented chip scale packages, where a wafer with LEDs is scribed into segments, placed on a stretchable substrate, and optically opaque materials are deposited in separation gaps to provide both optical and electrical connectivity, allowing for individual addressability of each LED segment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wafer level processing is used to create segmented matrix LEDs, then manufacturing cost is reduced and reliability is improved, but light guiding issues and color variations occur due to monolithic blocks
Solution Approach 1:
The patent divides the monolithic wafer into multiple segmented blocks using scribing and stretching techniques. Each segment is optically isolated from others through physical separation and filling of separation gaps with optically opaque materials, eliminating light guiding between segments while maintaining wafer-level processing benefits
Solution Approach 2:
The patent applies different optical properties to different regions of the wafer. Specifically, optically opaque materials are applied in separation gaps between segments to block light guiding, while the LED blocks themselves maintain their light-emitting properties. This local differentiation resolves the color variation issue
2Object-generated harmful factors
If light emitters are widely separated on a wafer, then optical isolation is improved, but space is wasted and manufacturing cost increases
Solution Approach 1:
The patent applies partial separation by filling only the separation gaps between segments with optically opaque materials, rather than adding large spacing between all emitters. This provides sufficient optical isolation while maintaining close packing of segments, thus utilizing wafer space efficiently
Solution Approach 2:
The patent introduces optically opaque materials as intermediary substances in the separation gaps between LED segments. These materials act as optical barriers that provide effective isolation without requiring physical distance between segments, enabling close packing while maintaining optical independence
3Area of stationary object
If segments are closely packed on a wafer, then space efficiency is improved, but optical separation between segments becomes difficult
Solution Approach 1:
The patent introduces optically opaque materials as intermediary substances in the separation gaps between LED segments. These materials act as optical barriers that provide effective isolation without requiring physical distance between segments, enabling close packing while maintaining optical independence
Solution Approach 2:
The patent changes the optical parameters of the separation regions by filling them with materials having different optical properties (optically opaque) compared to the LED segments. This parameter change enables optical isolation even when segments are closely spaced
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 enables cost-effective and space-efficient production of closely packed yet optically well-separated light emitters, reducing color shading and improving contrast in adaptive flash and IR illumination applications.
Implementation Method 1
The scribed wafer is placed on a stretchable substrate or tape. The tape is stretched and a layer of optically opaque, either highly reflective or absorbing, material is placed in the separation gaps.
Implementation Method 2
a layer of optically opaque, either highly reflective or absorbing, material is placed in the separation gaps
Implementation Method 3
a layer of optically opaque, either highly reflective or absorbing, material is placed in the separation gaps
Data Source
AI summary
Described herein is a method and system for dual stretching of wafers to create isolated segmented chip scale packages. A wafer having an array of light-emitting diodes (LEDs) is scribed into LED segments, where each LED segment includes a predetermined number of LEDs. The scribed wafer is placed on a stretchable substrate or tape. The tape is stretched and a layer of optically material is placed in the separation gaps. The stretched wafer is scribed on a LED level. The tape is stretched and another layer of optically opaque material is placed in the separation gaps. The same or different optically opaque material can be used for the layers. The two layers of optically opaque material are formed to provide electrical connectivity between the LEDs in each LED segment. In an implementation, each segment or LED is individually addressable.