Universal Lead Frame Without Tie Bars for IC Packages
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Solution Overview
Problem
Existing lead frame designs for integrated circuit (IC) packages are not uniform and often require large tie bars at corners, necessitating non-uniform lead arrangements and longer wire connections, which complicates the accommodation of different IC designs and increases wire length.
Innovation Solution
A universal lead frame structure with varying length lead fingers that extend from a center region to hold the die attach paddle in place, eliminating the need for tie bars and allowing for a more compact and adaptable design, where lead fingers of different lengths and widths facilitate shorter wire connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If tie bars are used to hold the die attach paddle in place, then the die attach paddle is securely positioned, but the tie bars occupy substantial area at each corner of the lead frame, requiring non-uniform lead arrangements and longer wire connections
Solution Approach 1:
The patent removes the tie bars from the lead frame structure entirely. Instead of using separate tie bars to hold the die attach paddle, the design uses lead fingers that directly support the paddle without requiring additional corner-mounted tie bar elements, thereby eliminating the area occupation problem
Solution Approach 2:
The patent combines the functions of lead fingers and support structure into a single integrated element. The lead fingers serve both as electrical connection paths and as mechanical support for the die attach paddle, eliminating the need for separate tie bars and enabling more efficient space utilization
2Stability of the object's composition
If tie bars are used to hold the die attach paddle, then the paddle is securely positioned, but the leads must be arranged at specific angles with adequate spacing, complicating the design for different IC configurations
Solution Approach 1:
The patent creates a universal lead frame design where the lead fingers can accommodate different IC configurations without requiring redesign. The uniform lead finger structure with varying lengths provides a flexible template that works for different numbers and arrangements of die pads, making the lead frame adaptable to various IC designs
Solution Approach 2:
The patent varies the lengths of lead fingers to optimize different connection requirements. By changing the length parameter of lead fingers rather than the overall structure, the design maintains uniformity while adapting to different IC configurations, reducing complexity
3Stability of the object's composition
If tie bars are used at corners of the lead frame, then the die attach paddle is held in place, but longer wires are required to connect the IC to leads at corner positions
Solution Approach 1:
The patent removes tie bars from the corner positions, allowing lead fingers to extend closer to the die attach paddle. This elimination enables shorter wire connections from the die pads to the lead fingers, reducing overall wire length while maintaining secure positioning
Data Source
AI summary
A lead frame for an integrated circuit (IC) package is disclosed. The lead frame includes a center region and a plurality of lead fingers surrounding the center region. The plurality of lead fingers that surrounds the center region defines a periphery region around the center region. A portion of the plurality of lead fingers extends from the center region to hold the center region in place. Tie bars that are typically used to hold the center region in place may not be included in the lead frame.