Chip Package Color Filter Layer Optical Crosstalk
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical crosstalk in chip packages, particularly in image sensors, leads to distorted images due to infrared light passing through non-photo-sensitive regions, degrading image quality.
Innovation Solution
A chip package design featuring a substrate with a sensing device, a color filter layer on the upper surface, and a redistribution layer on the lower surface, with openings to shield and absorb external light sources, reducing optical crosstalk by blocking or absorbing unwanted light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional chip package structure is used without additional light filtering, then the device complexity is low, but optical crosstalk occurs and image quality deteriorates
Solution Approach 1:
The chip package structure is segmented into distinct functional layers: a substrate containing sensing devices, a first color filter layer on the upper surface, and a second color filter layer on the lower surface. Each layer performs specific light filtering functions to prevent optical crosstalk while maintaining clear imaging through designated openings.
Solution Approach 2:
Color filter layers are introduced as intermediary structures between the external environment and the sensing devices. These filter layers selectively block unwanted wavelengths of light (particularly infrared) while allowing visible light to pass through, thereby preventing optical crosstalk without completely isolating the sensing region.
2Object-affected harmful factors
If color filter layers are added to block infrared light, then optical crosstalk is reduced, but the device complexity increases
Solution Approach 1:
The color filter layers are applied selectively to specific regions of the chip package. The first color filter layer is disposed on the upper surface in regions adjacent to sensing devices, and the second color filter layer is disposed on the lower surface, creating localized light filtering exactly where optical crosstalk occurs without adding filters to the entire substrate.
Solution Approach 2:
The light filtering solution is implemented in multiple dimensions by placing color filter layers on both the upper and lower surfaces of the substrate. This bidirectional filtering approach blocks infrared light from entering the sensing region from either direction, providing comprehensive optical crosstalk prevention.
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 mitigates optical crosstalk, enhancing image quality by preventing external light from interfering with the sensing region, thereby improving the overall performance of the chip package.
Implementation Method 1
a first color filter layer disposed on the upper surface of the substrate to shield the light source
Data Source
AI summary
A chip package is provided. the chip package includes a substrate having an upper surface, a lower surface, and a sidewall surface that is at an edge of the substrate. The substrate includes a sensing device adjacent to the upper surface of the substrate to sense a light source. The chip package also includes a first color filter layer disposed on the upper surface of the substrate to shield the light source. The first color filter layer includes an opening, so that the first color filter layer surrounds the sensing device via the opening. In addition, the chip package includes a redistribution layer disposed on the lower surface of the substrate. A method of forming the chip package is also provided.