Strip-Shaped QFN Package for LED Driver ICs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LED display driver IC packages face challenges in increasing the number of drive channels without expanding the IC area, leading to increased bond wire length and impedance, which exceeds the capacity of printed circuit boards.
Innovation Solution
The IC package, die carrier, and die adopt a strip-shaped quad flat no-lead (QFN) or quad flat package (QFP) design where leads are disposed on four sides, with a long side twice or more the length of a short side, reducing bond wire impedance by matching the die carrier shape to the die.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of drive channels is increased by doubling the area of the conventional die, then the number of drive channels is improved, but the area of the IC package increases by four times
Solution Approach 1:
The patent applies asymmetry by changing the IC package from a conventional square shape to a rectangular shape with a length-to-width ratio of 2:1 or greater. This asymmetric configuration allows the leads to be arranged more efficiently along the longer sides, enabling a higher number of drive channels (e.g., 96 channels) within a smaller package area compared to doubling the die area in conventional square packages.
Solution Approach 2:
The patent utilizes dimensional optimization by extending the package in one dimension (length) while constraining the other dimension (width), creating a rectangular footprint rather than a square one. This dimensional change allows for increased lead count and drive channels along the longer sides without proportionally increasing the overall package area, achieving higher productivity with reduced area occupation.
2Productivity
If the number of drive channels is increased by using more leads, then the number of drive channels is improved, but the area of the IC package increases significantly
Solution Approach 1:
The asymmetric rectangular package design with a 2:1 or greater length-to-width ratio optimizes lead placement by concentrating leads along the longer sides. This configuration allows for a higher density of leads (e.g., 24 leads per long side in a 96-channel package) without increasing the package area proportionally, enabling increased productivity with minimal area expansion.
Solution Approach 2:
The patent changes the geometric parameters of the package from a square configuration to a rectangular configuration with specific aspect ratio constraints (length/width ≥ 2). This parameter change optimizes the relationship between the number of leads and the package area, allowing for increased lead count and drive channels while controlling the overall area growth.
3Productivity
If the area of the IC package is increased to accommodate more leads, then the number of drive channels is improved, but the printed circuit board has no more area for placing additional ICs
Solution Approach 1:
The asymmetric rectangular package design minimizes the area occupied by the IC package while maximizing the number of drive channels. By concentrating leads along the longer sides in a compact rectangular footprint, the package achieves high channel density (e.g., 96 channels) with reduced area, leaving more PCB real estate available for placing additional ICs and components.
Solution Approach 2:
The patent optimizes the package area parameter by implementing a rectangular shape with a specific aspect ratio (length/width ≥ 2). This parameter optimization allows for increased lead count and drive channels within a controlled area footprint, ensuring that the IC package does not consume excessive PCB area and maintains compatibility with standard PCB layouts.
Data Source
AI summary
An integrated circuit package, a die carrier, and a die are provided. The die carrier includes at least one die pad and a plurality of leads. The at least one die pad is suitable for carrying the die. The leads surround the at least one die pad. The leads are disposed on four sides of the die carrier. A length of a long side among the four sides is twice or more a length of a short side among the four sides. The die carrier is suitable for a QFN package or a QFP package.