Patterned Leadframe Power Distribution in BGA Packages
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor device packaging methods, such as wirebonding, face challenges in delivering power uniformly across the integrated circuit die due to the large size of leadframe conductors, leading to power loss and performance impairment, especially in high-speed devices, and are costly compared to flip-chip packaging.
Innovation Solution
A patterned leadframe structure is encapsulated and connected to the integrated circuit die to distribute power and ground across the die area, using short, low-profile wirebonds and conductive die attach techniques, ensuring that power and signal lines are connected efficiently without extending leadframe conductors to the package surface, thereby improving power distribution and increasing signal line density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional wirebond packaging is used with peripheral bonding pads, then the package structure is simple and cost-effective, but power distribution across the die area becomes non-uniform causing voltage drops and performance impairment
Solution Approach 1:
The patent segments the power distribution function by introducing multiple independent leadframe conductors (first, second, and third conductors) that connect to different bonding pad locations on the die. This segmentation allows power to be delivered from multiple peripheral locations simultaneously, improving uniformity across the die area while maintaining the simplicity of conventional wirebond packaging processes
Solution Approach 2:
The patent transitions from a two-dimensional peripheral power distribution (single layer of bonding pads around the edge) to a three-dimensional configuration by stacking leadframe conductors in multiple layers. The first conductor connects to first bonding pads, the second conductor to second bonding pads, and the third conductor to third bonding pads at different vertical levels, enabling more comprehensive power distribution across the die area
2Reliability
If leadframe conductors are extended to the package surface for external connections, then electrical connectivity is achieved, but the integrated circuit die becomes vulnerable to moisture and environmental damage
Solution Approach 1:
The patent implements nesting by placing the leadframe conductors inside the encapsulation body, which contains a cavity that houses both the die and the conductors. The encapsulation material seals the entire assembly, protecting the internal electrical connections from environmental factors while maintaining external electrical connectivity through sealed pathways
3Adaptability or versatility
If the number of signal and power lines is increased to match circuit complexity, then device functionality is enhanced, but the available space for connections decreases due to shrinking device sizes
Solution Approach 1:
The patent utilizes the vertical dimension by implementing multi-layer leadframe conductors at different heights within the encapsulation body. This allows multiple signal and power lines to be routed through the same horizontal footprint by stacking them vertically, effectively increasing connection capacity without requiring additional lateral space
Data Source
AI summary
A packaging assembly (30), such as a ball grid array package, is formed which distributes power across an interior region of an integrated circuit die (52) by using an encapsulated patterned leadframe conductor (59) that is disposed over the die (52) and bonded to a plurality of bonding pads (45) formed in a BGA carrier substrate (42) and in the interior die region, thereby electrically coupling the interior die region to an externally provided reference voltage.