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Novel package design to mitigate bump EM challenge Disclosure Number: IPCOM000244045D
Publication Date: 2015-Nov-09
Document File: 6 page(s) / 935K

Publishing Venue

The Prior Art Database


This disclosure describes Novel package design to mitigate bump EM challenge

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Novel package design to mitigate bump EM challenge

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Problem Solved: The impedance variation of on die/package power routing causes uneven current distribution. This may create electromigration (EM) issues in a local area for package/device design and affects long term reliability of the device.

Prior Art: Not aware of any prior art that involves sending power over a Si bridge to help in IR drop or any specific on-bridge layout pattern required for the same.

Brief Description of Invention: The basic ideal is to improve the current distribution by breaking the low resistance path into several multiple power routing paths. The current will distribute evenly across all the paths if the total resistance of each path is similar. We are able to create paths with similar resistance by measures such as controlling the portion of package routing vs. die routing, changing routing width. This reduces current flow congestion and EMI issue is alleviated.

Benefits/Advantages: This technique reduces EM issues due to uneven current distribution without requiring additional routing resources (area, bump)


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Problem to be Solved

Current is not evenly distributed in the case where multiple power/ground vias are used in parallel

  The root cause of the uneven distribution is due to impedance difference between package surface routing and die routing

Uneven distribution creates EM issue


Top view PWR Flow




PWR Flow

Side view



GND/ PWR micro bump

GND/ PWR micro bump with high current


PKG surface routing


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Prior Art

In package routing, the designer adjusts the shape of the package routing to affect the current flow through a particular region to improve the EM situation


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Brief Description of Invention


  The resistance on each of the current flow paths determines the current distribution over those paths

Idea: Create multiple power flow paths to help spread electrical current across multiple vias and hence reduce the risk on EM

  Create multiple surface routing paths that connect different vias

  Determine the impedance ratio needed to meet special current dist...