Mold-Compound Interconnect Bridge to Reduce Warpage and Cost
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Solution Overview
Problem
The embedded multi-die interconnect bridge (EMIB) faces thermomechanical issues due to the differential thermal expansion between silicon and build-up dielectric materials, leading to stresses and warpage, and is costly to manufacture with traditional wafer fabrication processes.
Innovation Solution
The development of electrical interconnect bridges using a mold compound material with multiple routing layers and vias, where all routing layers have the same coefficient of thermal expansion, mitigating thermomechanical issues and reducing manufacturing costs by employing low-cost techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional silicon interposer with TSV is used, then high density interconnects are achieved, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent replaces expensive silicon interposers with disposable organic substrate carriers that are removed after serving their purpose during assembly. The organic substrate acts as a temporary platform for forming interconnect bridges, which are then transferred to the final package without the substrate, eliminating the need for costly silicon interposers and TSV fabrication
Solution Approach 2:
The patent extracts the interconnect bridge structure from the silicon interposer context and forms it directly on an organic substrate carrier. The interconnect bridges are formed, populated with conductive material, and then the entire assembly is transferred to the final package, leaving behind the simple organic carrier that is subsequently removed, thereby eliminating complex silicon-based interposer structures
2Manufacturing precision
If silicon interposer with TSV is used, then high density interconnects are achieved, but manufacturing cost increases
Solution Approach 1:
The patent uses inexpensive organic substrate carriers as temporary platforms for forming interconnect bridges. These disposable carriers replace expensive silicon interposers and enable the use of cost-effective organic substrate fabrication processes, significantly reducing manufacturing costs while achieving the same interconnect density
Solution Approach 2:
The patent replaces complex mechanical TSV (through-silicon via) fabrication processes with simpler planar fabrication processes on organic substrates. The interconnect bridges are formed using standard PCB-like techniques on the organic carrier, avoiding the need for deep via drilling, plating, and filling operations required for TSV, thereby reducing manufacturing complexity and cost
3Reliability
If silicon and build-up dielectric materials are combined, then interconnect functionality is achieved, but thermomechanical stresses and warpage occur
Solution Approach 1:
The patent changes the material parameter (coefficient of thermal expansion) by using organic substrate materials that have CTE values better matched to silicon than traditional build-up dielectrics. This parameter change reduces thermomechanical stress during thermal cycling and processing, preventing warpage and delamination while maintaining interconnect functionality
Solution Approach 2:
The patent employs composite material structures where organic substrate carriers are combined with metal interconnect bridges and dielectric layers. The organic material provides a balanced CTE that compensates for thermal expansion differences, creating a composite structure that maintains thermomechanical stability across temperature variations while enabling functional interconnects
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
The solution effectively mitigates thermomechanical stresses and reduces manufacturing costs by using a mold compound material with a higher coefficient of thermal expansion than silicon, allowing for dense interconnects without the need for expensive silicon interposers and complex fabrication processes.
Implementation Method 1
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. In one aspect, the electrical interconnect bridge can mitigate thermomechanical issues, such as stresses and warpage, that can occur with typical EMIBs.
Implementation Method 2
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.
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.