LED Mounting on PCB via Fitting Holes for Solder-Free Repair
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional backlight units using light emitting diodes (LEDs) require soldering for mounting on printed circuit boards, making it difficult to replace defective LEDs and posing environmental concerns due to the use of solder.
Innovation Solution
A light source unit where LEDs are mounted on a printed circuit board using a fitting method instead of soldering, utilizing lead terminals with protruding portions and fitting holes to securely and electrically connect the LEDs without the need for solder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If soldering method is used to mount LEDs on printed circuit board, then electrical connection and mechanical strength are improved, but ease of repair and environmental compliance deteriorate
Solution Approach 1:
The lead terminal is divided into distinct functional segments: a mounting portion that inserts into the fitting hole, a head portion that makes electrical contact with the circuit board, and a base portion that connects to the LED. This segmentation allows the LED to be easily removed and replaced by simply pulling it out of the fitting hole without affecting the circuit board or requiring soldering tools.
2Strength
If soldering method is used to mount LEDs on printed circuit board, then electrical connection and mechanical strength are improved, but environmental compliance deteriorates
Solution Approach 1:
The soldering process and solder material are completely extracted from the mounting system. Instead of using solder to create electrical and mechanical connections, the invention uses a pure mechanical fitting structure where the lead terminal's protruding portion inserts into a fitting hole on the circuit board, eliminating all environmental concerns associated with solder.
3Ease of repair
If fitting method is used to mount LEDs on printed circuit board, then ease of repair and environmental compliance are improved, but manufacturing precision deteriorates
Solution Approach 1:
The lead terminal features an asymmetric cross-sectional shape in its protruding portion that corresponds to an asymmetric fitting hole shape on the circuit board. This asymmetric design provides precise positioning and orientation during insertion, ensuring the LED is correctly aligned without requiring complex alignment procedures or sacrificing manufacturing precision.
4Ease of manufacture
If fitting method is used to mount LEDs on printed circuit board, then ease of manufacture is improved, but reliability deteriorates
Solution Approach 1:
The mounting function and electrical connection function are merged into a single integrated structure. The lead terminal simultaneously provides mechanical support through its mounting portion in the fitting hole, electrical connection through its head portion contacting the circuit board, and structural integrity through its base portion connecting to the LED, eliminating the need for separate soldering operations.
Data Source
AI summary
A light source unit including light emitting diodes mounted on a printed circuit board by not using a soldering method but a fitting method, and a backlight unit and liquid crystal display including the light source unit. The light source unit includes light emitting diodes including lead terminals and a printed circuit board including a fitting hole. Each of the lead terminals includes a base part and a fitting part protruding from the base part. The fitting part of the light emitting diode is fitted into the fitting hole of the printed circuit board and so that the light emitting diode is mounted on the printed circuit board.