Semiconductor Package Routable Leadframe Parasitic Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor packages face challenges in achieving ultra-low RLC parasitics, high frequency bandwidth, circuit stability, and controllable broadband impedance, particularly in high-speed and high-frequency applications like 5G mobile devices, where existing designs suffer from poor insertion loss and resonance issues.
Innovation Solution
The semiconductor package incorporates a routable leadframe (RLF) structure with tunable interconnecting and bypass traces, varying dimensions of traces and pads to compensate for parasitics, and a flip chip QFN package framework that optimizes electrical and thermal performance, enabling broadband capability and resonance-free operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional semiconductor package structures are used, then manufacturing is simpler, but RLC parasitics are high and frequency bandwidth is limited
Solution Approach 1:
The package structure is segmented into distinct functional zones: a first region containing RF circuitry with optimized trace routing, and a second region containing mixed-signal circuitry. This segmentation allows each region to be optimized independently for its specific function, enabling ultra-low RLC parasitics in the RF region while maintaining manufacturability through standardized processes.
Solution Approach 2:
Different regions of the package are assigned different trace widths, via sizes, and material properties tailored to local requirements. The RF region uses narrower traces and smaller vias to minimize parasitics, while other regions use broader traces for power handling. This local optimization achieves high frequency bandwidth without requiring complete redesign of the entire package structure.
2Reliability
If trace dimensions are reduced to lower parasitics, then RLC performance improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs a multi-layer trace architecture where traces are distributed across different vertical layers rather than being confined to a single plane. This three-dimensional arrangement allows sufficient electrical performance with larger, more manufacturable trace dimensions at each layer, while the cumulative effect achieves the required low parasitics. Standard manufacturing processes can accommodate these larger dimensions with conventional precision tolerances.
3Reliability
If broadband impedance control is implemented, then frequency bandwidth increases, but circuit stability becomes more difficult to maintain
Solution Approach 1:
The package is divided into RF and mixed-signal regions with separate power and ground distribution networks. This segmentation isolates the broadband RF paths from the digital switching activity, allowing each region to be optimized for its specific stability requirements. The RF region maintains stable broadband impedance through dedicated reference planes, while the mixed-signal region handles transient loads independently.
Solution Approach 2:
Buffer zones and isolation structures are introduced between RF and mixed-signal regions to mediate interactions. These intermediary elements include guard rings, isolation trenches, and filtered power distribution networks that prevent digital switching transients from coupling into RF paths, thereby maintaining circuit stability across broadband frequencies.
Data Source
AI summary
A semiconductor package includes a die attach pad and a plurality of leads, and a die attached to the die attach pad and electrically coupled to the plurality of leads. The plurality of leads includes power leads and signal leads. An interconnecting trace is electrically coupled between a bond pad of the die and a via-pad. A via is coupled to the via-pad, and the via pad is coupled to one of the signal leads. A bypass trace includes a proximal end connected to the interconnecting trace and a distal end floating inside a mold compound of the semiconductor package.