Metal Shielding Layer Heat Dissipation in 3D CMOS Image Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Three-dimensional (3D) CMOS image sensors face challenges in dissipating heat and releasing static charge accumulated on the metal shielding layer, which can lead to malfunction due to excessive heat and electrostatic discharge (ESD), respectively.
Innovation Solution
The metal shielding layer is electrically connected to the metal films in the second multi-layer structure through conductive vias, allowing for heat dissipation and static charge release, thereby addressing thermal dissipation and ESD issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metal shielding layer is added to block light and protect the image sensor, then light shielding effectiveness is improved, but heat dissipation capability deteriorates
Solution Approach 1:
A heat dissipation layer is introduced as an intermediary component between the metal shielding layer and the substrate. This heat dissipation layer acts as a thermal mediator that conducts heat away from the metal shielding layer through thermal conduction, thereby resolving the heat accumulation problem caused by the light-shielding metal layer while preserving its light-blocking function.
2Object-affected harmful factors
If a metal shielding layer is added to protect the image sensor, then light shielding effectiveness is improved, but static charge release capability deteriorates
Solution Approach 1:
The heat dissipation layer serves as an electrical intermediary that provides a conductive path for static charge dissipation. By connecting the metal shielding layer to the substrate through this conductive layer, accumulated electrostatic charge can be safely discharged, preventing ESD damage while maintaining the metal shielding layer's light-blocking protection.
3Reliability
If the metal shielding layer is electrically connected to the substrate through conductive vias, then static charge release capability is improved, but manufacturing complexity increases
Solution Approach 1:
The conductive vias for static charge dissipation are merged with the existing interlayer dielectric structure and signal routing infrastructure. By integrating the ESD protection pathways into the standard CMOS fabrication process and existing layer architecture, the patent achieves static charge release capability without proportionally increasing manufacturing complexity.
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 prevents malfunction by ensuring efficient heat dissipation and static charge release, ensuring the normal operation of the 3D CMOS image sensor.
Implementation Method 1
One challenge of the 3D CMOS image sensor is how to dissipate heat generated within the image sensor because excessive heat may adversely affect the image sensor
Implementation Method 2
Another challenge is how to release/discharge the static charge accumulated within or on light shielding metal in the image sensor. The accumulated static charge may cause an electrostatic discharge (ESD), which can damage an integrated circuit (IC) device in the image sensor
Data Source
AI summary
An integrated circuit includes a first semiconductor device, a second semiconductor device, and a metal shielding layer. The first semiconductor device includes a first substrate and a first multi-layer structure, and the first substrate supports the first multi-layer structure. The second semiconductor device includes a second substrate and a second multi-layer structure, and the second substrate supports the second multi-layer structure. The metal shielding layer is disposed between the first multi-layer structure and the second multi-layer structure, wherein the metal shielding layer is electrically connected to the second semiconductor device.