LED Package Lead Frame Terminal Segmentation for Testing Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light emitting diode packages face reliability issues during electrical testing and bonding to printed circuit boards due to restricted terminal width and arrangement, leading to potential failures.
Innovation Solution
The design includes lead frames with terminals of varying widths and arrangements, where specific terminals are separated to prevent short circuits and ensure stable bonding, with a dummy terminal aiding in reliable mounting, and a heat sink with zone-specific heat dissipation fins to manage thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If terminals are arranged with restricted width and intervals within the package body, then the package structure is compact, but electrical testing reliability fails
Solution Approach 1:
The terminal structure is segmented into multiple sections with varying widths. The first terminal has a first width in the crossing region and a second width outside the package body, where the second width is greater than the first width. This segmentation allows the terminal to provide sufficient bonding area for electrical testing while maintaining a compact arrangement within the package body.
Solution Approach 2:
Different regions of the terminal have different widths to satisfy different functional requirements. The crossing region within the package body has a smaller width to maintain compactness, while the region outside the package body has a larger width to ensure reliable electrical testing and bonding. This local quality variation resolves the contradiction between compactness and testing reliability.
2Area of stationary object
If terminals are arranged with restricted width and intervals within the package body, then the package structure is compact, but bonding reliability to printed circuit board fails
Solution Approach 1:
The terminal is divided into different width sections, with the outer region having a greater width than the inner crossing region. This segmentation provides sufficient bonding area for reliable connection to the printed circuit board while maintaining compact terminal arrangement within the package body.
Solution Approach 2:
The terminal exhibits local quality variation with different widths at different locations. The expanded width outside the package body provides adequate bonding surface area for reliable electrical connection, while the compact width inside the package body maintains space efficiency.
3Adaptability or versatility
If separate terminals are placed between existing terminals at both sides of the package body, then terminal connectivity is improved, but terminal width and arrangement restrictions cause testing failure
Solution Approach 1:
Each terminal is segmented into multiple width sections, allowing the terminal structure to accommodate both the need for additional connectivity terminals and the need for sufficient bonding area. The varying width sections ensure that even with increased terminal count, each terminal maintains adequate dimensions for reliable electrical testing.
Solution Approach 2:
The terminal structure uses local quality variation with different widths at different positions. This allows the package to include multiple terminals for improved connectivity while ensuring that each terminal has sufficient bonding area in its outer region for reliable electrical testing, overcoming the restrictions imposed by increased terminal density.
Data Source
AI summary
The present invention provides a light emitting diode package including a light emitting diode chip, a lead frame having a chip area on which the light emitting diode chip is disposed, and a package body having a cavity and supporting the lead frame. The chip area is exposed through the cavity. The lead frame includes a first terminal group disposed at a first side of the chip area and a second terminal group disposed at a second side of the chip area. The first terminal group and the second terminal group each include a first terminal connected to the chip area and a second terminal separated from the chip area. The second terminal of the first terminal group is exposed through the cavity, and the second terminal of the second terminal group is buried in the package body.