Backlight Module Thermal Design via Flexible Circuit Board Heat Dissipation
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Solution Overview
Problem
Conventional backlight modules for portable devices face challenges in heat dissipation due to insufficient contact area between the light source module and the supporting frame, leading to inefficient heat conduction and increased production costs, which impairs portability and flexibility.
Innovation Solution
A backlight module design featuring a flexible circuit board with a heat-dissipating area and a heat conductive glue layer that increases the contact area between the light source module and the supporting frame, utilizing a metal layer and through holes filled with heat conductive material to enhance heat transfer, and a bent holding portion to create multiple heat-dissipating paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the area of the supporting frame is increased to facilitate heat dissipating, then heat dissipation efficiency is improved, but production cost and weight increase, impairing portability
Solution Approach 1:
The supporting frame is designed with non-uniform thickness, being thicker at locations requiring enhanced heat dissipation (such as near the light source module) and thinner at other areas. This local variation in thickness provides superior heat dissipation efficiency where needed while minimizing overall weight and material usage compared to a uniformly thick frame.
2Ease of manufacture
If a single-sided adhesive tape is used to fasten the light source module to the supporting frame, then ease of assembly is improved, but contact area between light source module and supporting frame is insufficient, resulting in poor heat conduction
Solution Approach 1:
The adhesive tape and heat conductive material are combined into a single integrated layer. The heat conductive material is disposed on the adhesive tape, creating a composite structure that simultaneously provides mechanical bonding and thermal conduction. This merged structure maintains the ease of assembly advantage while dramatically improving heat conduction efficiency between the light source module and supporting frame.
3Temperature
If the area of the supporting frame is increased to facilitate heat dissipating, then heat dissipation efficiency is improved, but production cost increases
Solution Approach 1:
The supporting frame employs non-uniform thickness distribution, concentrating material where heat dissipation is most critical rather than uniformly increasing the entire frame area. This localized approach achieves effective heat dissipation while minimizing overall material consumption and production cost.
Solution Approach 2:
The heat conductive material acts as an intermediary substance between the light source module and the supporting frame. This intermediate layer enhances thermal coupling efficiency, allowing the supporting frame to achieve superior heat dissipation performance without requiring increased frame area or additional costly structural modifications.
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
Effectively guides and transfers heat generated by high-density light sources, improving heat dissipation efficiency while maintaining portability and reducing production costs by enhancing thermal conductivity and contact area.
Implementation Method 1
the heat conductive glue layer is disposed between the flexible circuit board and the holding portion for fastening the light source module to the holding portion and for attaching the light source-bearing area and/or at least a portion of the heat-dissipating area of the flexible circuit board to the inner side of the holding portion
Implementation Method 2
The heat-dissipating area includes a substrate and a metal layer; the flexible circuit board further has a plurality of through holes formed in the heat-dissipating area and has a heat conductive material filled therein
Data Source
AI summary
A backlight module includes a light guide plate, a light source module, a supporting frame, and a heat conductive glue layer. The light guide plate has a light-entering end; the light source module is disposed corresponding to the light-entering end and includes a flexible circuit board and a plurality of light sources. The flexible circuit board extends along the light-entering end and has a light source-bearing area and a heat-dissipating area, wherein a width of the heat-dissipating area in a direction perpendicular to the light-entering end is not smaller than a width of the light source-bearing area. The plurality of light sources are disposed in the light source-bearing area. The supporting frame has a holding portion which is bent to form an accommodation space for accommodating the light source module and the light-entering end. The heat conductive glue layer is disposed between the heat-dissipating area and an inner side of the holding portion for conducting heat from the heat-dissipating area to the holding portion.