Light Source Assembly Welding via Air Interface
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Solution Overview
Problem
Conventional light source assembly welding processes result in non-uniform thermal stresses and potential damage due to high temperatures, leading to irregular warpages and reduced optical efficiency, as the heat-conducting paths between the light bar and back plate are mismatched and require excessive energy for deeper welding.
Innovation Solution
A method involving a weld-processing area with an air interface between the light bar and back plate, where a laser beam is reflected to melt and fill the area, reducing laser power and preventing damage, using connecting portions formed by stamping to separate the light bar and back plate, and forming a welding layer for effective heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the welding process uses high laser power to achieve deeper heat conduction, then the heat conduction effect is improved, but the light bar is likely to be damaged due to excessive temperature
Solution Approach 1:
The patent introduces a preliminary air interface between the light bar and back plate before welding. This air interface acts as a thermal insulation barrier that prevents excessive heat from damaging the light bar while still allowing sufficient heat conduction for effective welding. The air gap is created by positioning the light bar at a specific distance from the back plate surface.
Solution Approach 2:
The air interface serves as an intermediary layer between the light bar and back plate. It mediates the thermal interaction by allowing controlled heat transfer - sufficient for welding but limited enough to prevent thermal damage to the light bar. This intermediary air layer resolves the contradiction between needing deep heat conduction and avoiding overheating.
2Device complexity
If the welding process directly contacts the light bar with the back plate, then the welding process is simpler, but non-uniform thermal stresses are generated due to mismatched heat-conducting paths
Solution Approach 1:
The patent applies a preliminary action by creating an air interface gap before the welding process. This pre-established gap ensures uniform thermal stress distribution during welding by preventing direct contact between the mismatched heat-conducting surfaces, thereby eliminating the thermal stress uniformity problem while adding minimal complexity to the overall process.
3Speed
If the welding process heats the peripheral position first, then the welding process starts at the edge, but the light bar becomes inclined or the back plate develops irregular warpages
Solution Approach 1:
The air interface gap is established as a preliminary measure before welding begins. This pre-positioning prevents the light bar from tilting during the welding process by maintaining a consistent distance from the back plate surface, thereby preventing inclination and warpage issues while allowing the welding process to proceed at normal speed.
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 method ensures uniform thermal stress, prevents damage, and enhances the quality of the light source assembly by allowing deeper heat conduction without excessive energy, improving the flatness and optical efficiency of the backlight module.
Implementation Method 1
a laser beam is reflected back and forth between the back plate and the light bar to melt the light bar and the back plate in the weld-processing area rapidly
Implementation Method 2
One of the major functions of the welding layer 170 is to transfer the heat generated by the light bar 110 to the back plate 130 and further to the ambience
Data Source
AI summary
A light source assembly and a method for manufacturing the same are provided. The method for manufacturing the light source assembly includes the following steps. A back plate and a light bar are provided, in which the light bar includes a substrate and plural light emitting diodes disposed on a mounting surface of the substrate. The light bar is disposed on the back plate and a weld-processing area which includes an air interface is formed between the light bar and the back plate. The light bar and/or the back plate are/is melted by welding to form melted materials for filling the weld-processing area to fix the substrate on the back plate.