Light Emitting Device Mounting Board Block for Reduced Depth
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Solution Overview
Problem
Existing light emitting devices for liquid crystal display backlights have a significant depth, which limits the miniaturization of devices due to the bulky structure of the thin light emitting devices used in backlight units.
Innovation Solution
A light emitting device mounting board block with a plate-shaped lead frame and a resin molded body having a recessed portion, where the lead frame includes support leads and outer leads connected to the resin molded body, allowing for a thinner package by reducing the depth of the light emitting device through strategic cutting and bending of the leads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a conventional light emitting device structure is used, then the device can provide sufficient light emission, but the depth and thickness of the device become too large
Solution Approach 1:
The patent reconfigures the lead frame structure from a conventional three-dimensional arrangement to a flattened two-dimensional layout. The lead frame is designed with a plate shape where the light emitting device is mounted on one surface, and the leads extend planarly to connection terminals. This dimensional transformation reduces the depth direction size while maintaining electrical connectivity and light extraction functionality through optimized lead routing in the length and width directions.
Solution Approach 2:
The lead frame is segmented into distinct functional regions: a mounting area for the light emitting device, support leads for mechanical and electrical support, outer leads for electrical connection, and connection terminals. This segmentation allows each component to be optimized independently - the mounting area can be minimized for thinness, while the leads are routed efficiently to maintain electrical performance without increasing overall device depth.
2Length of moving object
If the depth of the light emitting device is reduced, then the device size and thickness decrease, but the mechanical strength and electrical connectivity may be compromised
Solution Approach 1:
The lead frame employs local quality optimization by varying the thickness and cross-sectional area of different lead portions. The support leads have increased thickness in regions requiring mechanical strength to hold the light emitting device, while the outer leads are optimized for electrical connectivity. This localized structural enhancement maintains mechanical strength without increasing the overall device depth, as the reinforcement is applied only where specifically needed rather than uniformly throughout the entire lead frame.
3Length of moving object
If the lead frame structure is simplified to reduce depth, then the device thickness decreases, but the electrical connectivity and signal transmission may be affected
Solution Approach 1:
The outer leads serve as intermediary elements that efficiently transfer electrical signals from the light emitting device mounting area to the connection terminals. These leads are strategically positioned and dimensioned to minimize electrical resistance and inductance while maintaining the flattened device structure. The intermediary lead structure ensures reliable electrical connectivity without requiring vertical depth, as the electrical path is optimized through the planar layout of the lead frame.
Data Source
AI summary
A light emitting device mounting board block includes: a lead frame having a plate-shape, the lead frame having a first surface, and a second surface located opposite to the first surface; and a resin molded body located on the first surface of the lead frame, the resin molded body having a recessed portion therein. The resin molded body includes a first lateral wall, a second lateral wall, a third lateral wall and a fourth lateral wall, the first and second lateral walls extending in a length direction, the third and fourth lateral walls extending in a width direction.