Light-Shielding Layer for Image Sensor Ghost Image Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor structures used in image-sensing devices suffer from random light reflection and refraction, leading to noise lights that cause ghost images, making it difficult to adjust image parameters and control yield.
Innovation Solution
A semiconductor structure comprising a chip with an image sensor, a light transmissive plate, a spacer, and a light-shielding or reflective layer, where the light-shielding layer absorbs or the reflective layer reflects noise lights, preventing ghost images by filtering out non-perpendicular light reflections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a light transmissive plate is disposed on the chip to protect the image sensor, then the image sensor can detect object images through the glass, but random reflection and refraction of light occur causing noise lights and ghost images
Solution Approach 1:
A light-shielding layer is introduced as an intermediary component between the light transmissive plate and the image sensor. This layer selectively blocks noise lights (reflected and refracted light) while allowing object images to pass through, thus resolving the contradiction between protecting the image sensor and preventing noise light interference
Solution Approach 2:
The space between the light transmissive plate and the image sensor is segmented into different functional zones using the light-shielding layer. The light-shielding layer is positioned at specific locations (surrounding the image sensor or on the back surface) to create distinct optical paths: one for object images and another for noise lights, enabling selective filtering
2Manufacturing precision
If noise lights cause ghost images, then image quality deteriorates, but adjusting parameters (brightness or contrast) becomes difficult and yield control becomes challenging
Solution Approach 1:
The light-shielding layer is incorporated during the manufacturing process to preliminarily eliminate noise lights and ghost images before the product reaches the customer. This preliminary action prevents image quality deterioration at the source, making subsequent parameter adjustments easier and improving yield control
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 filters out noise lights, allowing for improved image conditions and increased yield by preventing ghost images, enabling easier adjustment of parameters like brightness and contrast.
Implementation Method 1
the light-shielding layer may absorb noise lights, such that the noise lights may be filtered out to prevent the image sensor from generating ghost images
Implementation Method 2
the reflective layer may totally reflect noise lights to prevent the image sensor from generating ghost images
Data Source
AI summary
A semiconductor structure includes a chip, a light transmissive plate, a spacer, and a light-shielding layer. The chip has an image sensor, a first surface and a second surface opposite to the first surface. The image sensor is located on the first surface. The light transmissive plate is disposed on the first surface and covers the image sensor. The spacer is between the light transmissive plate and the first surface, and surrounds the image sensor. The light-shielding layer is located on the first surface between the spacer and the image sensor.