Offset Semiconductor Die Pad Array for Escape Routing
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Solution Overview
Problem
Traditional semiconductor die pad arrays have an undesirably large pad pitch, limiting the number of pads on the die surface and are inefficient for applications requiring minimal routing layers, as they struggle to escape more than two rows per routing layer, which is problematic for package technologies using buildup-type layering.
Innovation Solution
A semiconductor die structure with a semi-regular pad array pattern that includes offset rows of die pads, allowing unobstructed escape routing and compatibility with high-performance processes, enabling single-layer or reduced-layer escape routing and optimized die floor-planning for embedded die and flip-chip interconnect applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional rectangular, checkerboard or closest-packed pad arrays are used, then the pad pitch is large and the pattern is simple to manufacture, but the number of pads that can be put on the die surface is limited and escape routing requires many layers
Solution Approach 1:
The patent applies asymmetry by using a semi-regular pad array pattern where adjacent rows are offset from one another by a non-zero offset amount, breaking the symmetry of traditional rectangular or checkerboard patterns. This asymmetric arrangement creates unobstructed escape paths between pads, enabling more efficient routing with fewer layers while accommodating a higher density of pads on the die surface.
Solution Approach 2:
The patent utilizes dimensional optimization by carefully controlling the offset amount between adjacent rows to be less than the pad pitch, creating a staggered configuration that optimizes the two-dimensional space utilization. This dimensional arrangement allows escape routing to occur in the lateral dimension between offset rows, reducing the need for additional vertical routing layers.
2Quantity of substance
If traditional pad arrays with large pad pitch are used, then manufacturing is simpler, but the number of pads that can be placed on the die surface is limited
Solution Approach 1:
The patent changes the geometric parameters of the pad array by introducing an offset amount between adjacent rows that is less than the pad pitch. This parameter modification creates a semi-regular pattern that increases pad density while maintaining manufacturability. The offset parameter provides flexibility in optimizing both pad count and routing efficiency without requiring excessive manufacturing precision.
3Ease of operation
If offset rows with offset amount less than pad pitch are used, then escape routing is improved and fewer layers are needed, but the pad array pattern becomes more complex
Solution Approach 1:
The patent applies partial action by offsetting adjacent rows by an amount that is less than the full pad pitch, creating a partial stagger rather than a complete shift. This partial offset is sufficient to create unobstructed escape paths for routing while avoiding the full complexity of completely staggered patterns, achieving a balance between routing efficiency and pattern simplicity.
Data Source
AI summary
A structure includes a semiconductor die that has an arrangement of die pads on a surface of the semiconductor die. A first row of die pads consists of a first group of four die pads and run in a first direction. A second row of die pads are adjacent to the first row and consist of a second group of four die pads running in the first direction. The second row begins at a first offset in the first direction from where the first row begins. A third row of die pads are adjacent to the second row and comprise a third group of four die pads that run in the first direction. The third row begins at a second offset in the first direction from where the second row begins. This allows for relatively easy access to all of the die pads.