Tungsten-Capped Redistribution Layer for Chip X-Ray Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuits are vulnerable to reverse engineering via x-ray techniques, such as ptychographic x-ray laminography, which can quickly and easily reveal confidential chip designs, posing a security risk for proprietary designs.
Innovation Solution
A redistribution layer incorporating a tungsten cap layer with a thickness of at least 1 μm is integrated into the integrated circuit package to effectively block soft and ptychographic x-rays, enhancing design security by preventing x-ray detection of circuit layouts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a redistribution layer is used to electrically connect integrated circuits, then electrical connectivity is improved, but the integrated circuit becomes vulnerable to x-ray reverse engineering
Solution Approach 1:
The redistribution layer is constructed as a composite structure with a first conductive layer (copper or aluminum) providing electrical connectivity and a second tungsten layer providing x-ray shielding. This composite material approach allows simultaneous achievement of low electrical resistivity and high x-ray attenuation without compromising either function.
Solution Approach 2:
The redistribution layer is designed to perform multiple functions: the first conductive layer provides electrical connectivity between integrated circuits, while the second tungsten layer provides x-ray shielding. This multi-functional design eliminates the need for separate shielding structures and integrates security directly into the electrical interconnect system.
2Reliability
If conventional conductive layers are used for redistribution, then electrical conductivity is maintained, but they cannot block soft x-rays effectively
Solution Approach 1:
The patent employs a composite structure where copper or aluminum provides excellent electrical conductivity (resistivity less than 3.6×10^-8 Ω·m) while tungsten provides superior x-ray attenuation. The combination leverages the complementary properties of these materials to satisfy both electrical and shielding requirements.
Solution Approach 2:
The tungsten layer thickness is optimized to be greater than or equal to 1 μm, which is the critical threshold for effective soft x-ray blocking. This parameter optimization ensures sufficient x-ray attenuation while minimizing impact on electrical performance and manufacturing complexity.
3Object-affected harmful factors
If additional shielding layers are added to block x-rays, then security is improved, but manufacturing complexity increases
Solution Approach 1:
The redistribution layer structure is designed to simultaneously serve as both the electrical interconnect and the x-ray shielding barrier. By integrating the tungsten shielding layer directly into the redistribution layer stack, the patent eliminates the need for separate shielding structures, thereby maintaining manufacturing simplicity while achieving effective x-ray blocking.
Solution Approach 2:
The electrical conductive layer and x-ray shielding layer are merged into a single integrated redistribution layer structure. The first conductive layer (copper/aluminum) and second tungsten layer are deposited together in sequence, forming a unified component that performs both electrical connectivity and security functions without requiring additional manufacturing steps.
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 tungsten-capped redistribution layer effectively shields against soft x-ray beams, providing enhanced security for integrated circuit designs by blocking x-ray-based reverse engineering attempts, thereby protecting proprietary information.
Implementation Method 1
A redistribution layer incorporating a tungsten cap layer with a thickness of at least 1 μm is integrated into the integrated circuit package to effectively block soft and ptychographic x-rays
Implementation Method 2
The first conductive layer has a resistivity of less than 3.6*10−8 Ω·m and has a thickness of greater than or equal to 1 μm
Data Source
AI summary
A redistribution layer for an integrated circuit package is provided. The redistribution layer includes a first conductive layer and a second layer disposed directly on the first conductive layer. The first conductive layer has a resistivity of less than 3.6*10−8 Ω·m and has a thickness of greater than or equal to 1 μm. The second layer includes tungsten. An integrated circuit package is also provided that includes the redistribution layer electrically connecting a first integrated circuit of the first integrated circuit package to a first input/output of a frame of the integrated circuit package. The frame is connected to the first integrated circuit. A method for manufacturing a redistribution layer is also provided.