Mold-Compound Interconnect Bridge for Low-Warpage Multi-Die Packaging
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Solution Overview
Problem
Existing embedded multi-die interconnect bridges (EMIBs) face thermomechanical issues due to the differential thermal expansion between silicon and the build-up dielectric material in package substrates, leading to stresses and warpage.
Innovation Solution
The development of electrical interconnect bridges formed from low-cost mold compound material, utilizing low-cost techniques, and incorporating multiple routing layers with fine line and spaced (FLS) traces, which mitigates thermomechanical issues by matching the coefficient of thermal expansion (CTE) of the mold compound with the package substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If silicon material is used for interconnect bridge, then manufacturing precision and interconnect density are improved, but thermomechanical stresses and warpage increase due to differential thermal expansion
Solution Approach 1:
The patent changes the material parameter (CTE) of the interconnect bridge from silicon to mold compound material, matching the CTE of the package substrate. This parameter change eliminates differential thermal expansion, resolving the contradiction between achieving high interconnect density and avoiding thermomechanical stresses.
Solution Approach 2:
The patent uses mold compound material, which is a composite material commonly used in packaging, to fabricate the interconnect bridge. This composite material approach allows the bridge to have both the required interconnect functionality and thermal expansion characteristics that match the package substrate, reducing warpage and stresses.
2Manufacturing precision
If silicon interposer with TSV is used, then high-density interconnects are achieved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the interconnect bridge function from a separate silicon interposer and integrates it directly into the package substrate using mold compound material. This eliminates the need for TSVs and specialized interposer silicon, simplifying the packaging structure while maintaining high-density interconnect capabilities.
Solution Approach 2:
The mold compound material serves multiple functions: it provides the interconnect bridge structure, enables fine line and spaced traces for high-density interconnects, and matches thermal expansion characteristics of the substrate. This multi-functionality reduces overall device complexity compared to using separate silicon interposers.
3Manufacturing precision
If silicon interposer with TSV is used, then high-density interconnects are achieved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive silicon interposer material with mold compound material, which is a lower-cost material commonly used in packaging applications. This substitution significantly reduces manufacturing cost while maintaining the ability to achieve high-density interconnects through FLS traces.
Solution Approach 2:
The patent changes the material composition parameter from silicon to mold compound, which has lower material cost and can be processed using existing packaging manufacturing techniques. This parameter change enables cost-effective production of high-density interconnects without requiring expensive TSV fabrication processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively reduces thermomechanical stresses and warpage, enabling reliable and cost-effective high-density interconnects between heterogeneous dies on a single package substrate, while maintaining the advantages of EMIBs such as lower cost and simpler 2.5D packaging.
Implementation Method 1
mitigates thermomechanical issues by matching the coefficient of thermal expansion (CTE) of the mold compound with the package substrate
Data Source
AI summary
Electrical interconnect bridge technology is disclosed. An electrical interconnect bridge can include a bridge substrate formed of a mold compound material. The electrical interconnect bridge can also include a plurality of routing layers within the bridge substrate, each routing layer having a plurality of fine line and space (FLS) traces. In addition, the electrical interconnect bridge can include a via extending through the substrate and electrically coupling at least one of the FLS traces in one of the routing layers to at least one of the FLS traces in another of the routing layers.