Light Emitting Module Groove Thermal Expansion Compensation
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Solution Overview
Problem
Display devices experience a light-out phenomenon due to rapid temperature rise and thermal expansion mismatch between the light source structure and protective sealant, leading to increased maintenance costs and device scrapping.
Innovation Solution
A light-emitting module with a substrate and protective sealant where the thermal expansion rate of the sealant is greater than the substrate, featuring grooves on the substrate to mechanically compensate for thermal expansion, reducing the squeeze on light-emitting elements and preventing light-out by matching the expansion of the substrate with the sealant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the protective sealant has a higher thermal expansion rate than the substrate, then the sealant can accommodate thermal expansion differences, but it causes squeeze on the light-emitting elements leading to light-out phenomenon
Solution Approach 1:
The substrate is segmented into multiple regions by introducing grooves between adjacent light-emitting elements. These grooves divide the continuous substrate into discrete segments that can expand independently, preventing the accumulation of thermal stress that would otherwise squeeze the light-emitting elements.
Solution Approach 2:
The grooves are strategically positioned only in specific regions between light-emitting elements, creating local variations in substrate structure. This allows the substrate to have different expansion characteristics in different areas - constrained under the light-emitting elements and free to expand in the groove regions.
2Object-affected harmful factors
If grooves are added to the substrate to compensate for thermal expansion, then the squeeze on light-emitting elements is reduced, but the structural strength of the substrate may be compromised
Solution Approach 1:
The grooves are designed with asymmetric characteristics - they are positioned only between light-emitting elements and not directly under them. This asymmetric placement ensures that the substrate maintains sufficient structural integrity in the critical areas while providing expansion relief in the non-critical areas between elements.
Solution Approach 2:
Rather than creating a complete grid of grooves across the entire substrate, the invention applies grooves partially - only in the regions between light-emitting elements where expansion relief is needed. This partial application maintains overall substrate strength while providing sufficient thermal expansion compensation.
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 design effectively reduces the relative displacement between the substrate and protective sealant, minimizing the squeeze on light-emitting elements and preventing failures, thus overcoming the light-out issue and enhancing the reliability and longevity of display devices.
Implementation Method 1
the thermal expansion rate of the protective sealant is greater than a thermal expansion rate of the substrate... When the light source is turned on, the temperature of the light source structure may rise rapidly
Implementation Method 2
A plurality of grooves are defined in the side of the substrate facing the protective sealant... to mechanically compensate the substrate, so that the deformation of the substrate at the position of each of the grooves is relatively larger
Data Source
AI summary
A light-emitting module and a display device are disclosed. The light-emitting module includes a substrate, a light-emitting element, and a protective sealant. The protective sealant has a thermal expansion rate that is greater than a thermal expansion rate of the substrate. There is defined a plurality of grooves in a side of the substrate facing the protective sealant. Each groove is disposed between adjacent light-emitting elements.