Grooved Image Sensor Package Structure for Flare Reduction
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Solution Overview
Problem
Existing image sensor packages suffer from flare issues caused by package components such as the edge of the optically transmissive cover, adhesive material, bond wires, and bond pads, which can lead to image artifacts in advanced driver-assistance systems and autonomous driving systems.
Innovation Solution
The implementation of an image sensor package design that includes an optically transmissive cover with a groove along its entire perimeter, coupled with an image sensor die using an adhesive material, and surrounded by a mold compound that extends into the groove, helps mitigate flare by creating a mask layer that reduces stray light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If package components (edge of optically transmissive cover, adhesive material, bond wires, bond pads) are included in the image sensor package, then the package provides structural support and electrical connectivity, but these components cause flare and image artifacts
Solution Approach 1:
The patent extracts the harmful reflective surfaces by creating a groove that removes material from the optically transmissive cover's perimeter. This groove eliminates the edge of the cover that would otherwise reflect light and cause flare, while preserving the structural integrity of the package through the mold compound filling.
Solution Approach 2:
The mold compound acts as an intermediary material that fills the groove and provides an optically non-reflective surface. It mediates between the need for structural support (maintaining package integrity) and the need to reduce flare (by replacing reflective surfaces with non-reflective mold compound material).
2Reliability
If a groove is added along the entire perimeter of the optically transmissive cover, then flare is reduced by creating a mask layer, but the manufacturing complexity increases
Solution Approach 1:
The patent merges the groove formation step with the existing mold compound application process. The groove is created in the optically transmissive cover before molding, and the mold compound is then applied to fill the groove and encapsulate the package in a single integrated manufacturing flow, rather than adding separate complex assembly steps.
Solution Approach 2:
The groove is applied locally only at the perimeter of the optically transmissive cover where flare problems occur, rather than modifying the entire cover or package structure. This localized approach reduces manufacturing complexity by targeting only the specific area needed for flare reduction while leaving the rest of the package design unchanged.
3Object-affected harmful factors
If mold compound is applied to extend into the groove, then the mask layer is formed to reduce stray light, but the manufacturing process becomes more complex
Solution Approach 1:
The groove is formed in the optically transmissive cover before the mold compound application step. This preliminary action prepares the structure in advance so that when the mold compound is applied, it naturally flows into and fills the groove to create the mask layer, eliminating the need for additional post-molding processing steps to create the flare-reducing structure.
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 design effectively minimizes flare caused by package components, enhancing the image quality and reliability of image sensor packages used in critical applications like advanced driver-assistance systems and autonomous driving systems.
Implementation Method 1
irradiating the adhesive material through the optically transmissive cover with electromagnetic radiation to at least partially cure the adhesive material
Data Source
AI summary
Implementations of an image sensor package may include an optically transmissive cover including a groove along an entire perimeter of the optically transmissive cover; an image sensor die; an adhesive material coupling the optically transmissive cover to the image sensor die; and a mold compound contacting sidewalls of the image sensor die, contacting the adhesive material, and extending into the groove.