Rotatable Die-Substrate Layout for Shorter SerDes Traces

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Solution Overview

Problem

ASIC development incurs higher upfront costs and inefficiencies due to reduced SerDes channel numbers in cost-sensitive products, leading to suboptimal usage of available dies.

Innovation Solution

Configuring a die into multiple rotational states with bifurcated slices and a substrate that accommodates SerDes channels to minimize trace lengths and optimize communication pathways.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a die is configured as a lite version with reduced SerDes channel numbers to keep costs down, then manufacturing costs are reduced, but die usage efficiency deteriorates

Engineering Contradiction:
Improvemanufacturing costVSAvoiddie usage efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The die is designed with full SerDes functionality that can operate in multiple modes. The same die can be configured as either a full-featured version or a lite version with reduced channels, allowing one die design to serve multiple product tiers and applications, thereby maintaining high die usage efficiency while accommodating cost-sensitive markets

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If SerDes channels are reduced in lite versions, then device complexity is reduced, but trace route efficiency deteriorates

Engineering Contradiction:
ImproveSerDes channel countVSAvoidtrace route length
Core Design Contradiction:
Device complexityVSLength of stationary object

Solution Approach 1:

The substrate is designed with differentiated trace route configurations for different channel groups. Full SerDes channels utilize optimized trace routes with appropriate length and impedance control, while lite version channels use simplified trace configurations. This local differentiation allows the system to maintain optimal trace characteristics where needed while reducing complexity where full performance is not required

Inventive Principle:
Principle #3Local quality

3Reliability

If a die is fully utilized with all SerDes channels, then performance is improved, but manufacturing cost increases

Engineering Contradiction:
ImproveperformanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The system implements dynamic configuration capabilities where the die can be programmed or configured at runtime to enable or disable specific SerDes channels based on the application requirements. This allows a single die to deliver full performance when needed while operating in a reduced-channel mode for cost-sensitive applications, effectively decoupling performance from manufacturing cost

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4589637A1Die rotation setup with reduced serdes trace route lengths
Publication Date: 2025.07.23 CISCO TECHNOLOGY INC
  • EP4589637A1 patent drawingFigure 1
  • EP4589637A1 patent drawingFigure 2
  • EP4589637A1 patent drawingFigure 3

AI summary

Devices, systems, methods, and processes for allowing for the orientation of a die within a processing unit to be rotated while still maintaining suitable communication channels. During manufacturing, dies may be configured into multiple slices. Some of these slices may end up becoming non-functional due to a defect or other condition. However, a remaining functional slice may still be utilized and coupled to a substrate. The die can be configured such that the communication channels are available on one specific section of the die, even if it is rotated. Likewise, the substrate can also be configured to compress the location of the corresponding communication channels into a smaller area closer to that specific section. In this way, shorter trace lines can be made increasing performance and reducing manufacturing costs. Thus, the die can be rotated depending on which slice is functional, and still be suitable for coupling to the substrate.