3D IC Backside TSVs for Pre-bond Testing and Thermal Dissipation
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Solution Overview
Problem
Conventional 3D ICs face challenges in comprehensive pre-bond testing due to limited access to internal chip elements, particularly in the center, and inadequate thermal dissipation post-manufacturing.
Innovation Solution
Incorporating through-silicon vias (TSVs) across the entire design of each die for pre-bond testing and using them for improved thermal dissipation by applying a heat conductor on the top tier's backside TSVs post-bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If TSVs are placed across the entire design of each die for pre-bond testing, then testing coverage is improved, but device complexity increases
Solution Approach 1:
The patent applies multi-functionality by using TSVs for dual purposes: first as test access points during pre-bond testing, and then as thermal dissipation pathways after bonding. This eliminates the need for separate dedicated test structures, improving testing coverage without proportionally increasing device complexity.
Solution Approach 2:
The patent implements preliminary action by forming TSVs through the silicon substrate before bonding occurs. These TSVs are prepared in advance to serve as both test access points and future thermal pathways, enabling comprehensive testing while the structures are already in place, thus avoiding additional complexity from post-bonding modifications.
2Temperature
If a heat conductor is applied on the top tier's backside TSVs post-bonding, then thermal dissipation is improved, but manufacturing complexity increases
Solution Approach 1:
The TSVs are formed through the silicon substrate before bonding, preparing the thermal pathways in advance. This preliminary action simplifies post-bonding manufacturing because the structural framework for heat dissipation is already established, and only the heat conductor material needs to be applied.
Solution Approach 2:
The same TSV structures serve dual purposes: test access during pre-bond testing and thermal dissipation pathways after bonding. This multi-functionality reduces manufacturing complexity by eliminating the need for separate dedicated thermal management structures, as the test structures are repurposed for thermal management.
3Adaptability or versatility
If TSVs are used for both pre-bond testing and thermal dissipation, then resource utilization is improved, but reliability requirements increase
Solution Approach 1:
The patent implements multi-functionality by designing TSVs to serve as both test access points and thermal dissipation pathways. This increases resource utilization efficiency, though it does impose higher reliability requirements on the TSV structures to fulfill both functions effectively throughout the device lifecycle.
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
Enhances pre-bond testing coverage and thermal dissipation capabilities by enabling efficient power delivery and heat management across the 3D IC, improving testing efficiency and performance.
Implementation Method 1
A heat conductor can be formed from a passivation material layer, a thermal interface material layer, and a heat spreader... using the backside TSVs of the top tier to support improved heat dissipation
Data Source
AI summary
A three-dimensional (3D) integrated circuit (IC) can include a bottom tier with first circuitry and first backside TSVs coupled to a substrate; a top tier coupled to the first tier at a front side and having second circuitry and second backside TSVs; and a heat conductor on the second backside TSVs of the top tier. The heat conductor is coupled to the second backside TSVs to provide improved heat dissipation through the top tier. During pre-bond testing, the top tier can be tested at speed using the second backside TSVs.