Boron-10 Shielding for Thermal Neutron Protection in IC Packages
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Solution Overview
Problem
Integrated circuits, particularly SRAM cells in programmable logic ICs, are vulnerable to single event upsets (SEUs) caused by radiation, leading to incorrect bit storage and functional failures in radiation-laden environments.
Innovation Solution
Incorporating a thermal neutron shield with boron-10 in semiconductor packages to convert thermal neutrons into alpha particles, which have reduced penetration and can be easily stopped, thereby reducing the number of particles striking the IC die and minimizing SEUs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal neutron shielding with boron-10 is added to semiconductor packages, then reliability against SEUs is improved, but device complexity increases
Solution Approach 1:
The thermal neutron shield is nested within the existing semiconductor package structure, utilizing the package cavity space that would otherwise be empty. The shield is positioned between the IC die and the package lid, effectively nesting the shielding function within the existing package layers without requiring external additions.
Solution Approach 2:
The package lid is designed to serve multiple functions: it provides mechanical closure for the package, structural support, and thermal neutron shielding when constructed with or lined with boron-10 containing material. This multi-functionality reduces the need for separate dedicated shielding components.
2Object-affected harmful factors
If a thermal neutron shield is added to the semiconductor package, then protection against thermal neutrons is improved, but manufacturing complexity increases
Solution Approach 1:
The shielding effectiveness is achieved by modifying the material composition parameter of the package lid or internal shield, specifically incorporating boron-10 at concentrations of 5-65% by weight. This parameter change allows the use of existing manufacturing processes for forming metal or ceramic components, avoiding the need for new fabrication techniques.
Solution Approach 2:
The thermal neutron shield can be formed as a composite structure combining base materials (metal or ceramic) with boron-10 containing compounds or coatings. This composite approach leverages the mechanical properties of the base material while adding the neutron shielding capability through the boron-10 component.
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 use of boron-10 shielding materials effectively reduces the failure-in-time rate of semiconductor packages by inhibiting at least 50% of thermal neutrons, thereby enhancing the reliability of ICs in radiation-exposed environments.
Implementation Method 1
the shielding material includes boron-10 and is configured to inhibit a portion of thermal neutrons that encounter the thermal neutron shield from passing through the thermal neutron shield
Data Source
AI summary
A semiconductor package with thermal neutron shielding is disclosed. The semiconductor package includes a substrate and an integrated circuit die disposed on the substrate. The semiconductor package also has a thermal neutron shield including a shielding material. The shielding material includes boron-10 and is configured to inhibit a portion of thermal neutrons that encounter the thermal neutron shield from passing through the thermal neutron shield.