Image Sensor Package Guide Pin Alignment
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Solution Overview
Problem
Conventional image sensor packages face significant positional deviations between the sensor chip and the lens element due to manufacturing errors and limitations in positioning accuracy, particularly in high pin count COB-type packages, leading to suboptimal imaging performance and increased manufacturing complexity.
Innovation Solution
The image sensor package incorporates a substrate, sensor chip, frame, and guide pins, where the guide pins are formed integrally inside the frame by injection molding, aligning the lens central axis with the sensor chip's sensing region central axis, thereby reducing positional deviations and enhancing positioning accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional adhesive attachment methods are used to mount the sensor chip and frame, then the packaging process is simple, but positional deviation between the lens element and sensor chip increases
Solution Approach 1:
The patent introduces guide pins as an intermediary component between the frame and sensor chip. These guide pins are integrally formed with the frame through injection molding and provide precise mechanical positioning features that guide the sensor chip into correct alignment, thereby reducing positional deviation without complicating the overall packaging process
Solution Approach 2:
The guide pins are pre-formed integrally with the frame during the injection molding process before the sensor chip is mounted. This preliminary formation of positioning features ensures that the correct alignment structure is already in place, eliminating the need for complex post-assembly positioning operations
2Manufacturing precision
If multiple stepped positioning portions are formed on the supporting member to improve positioning accuracy, then manufacturing errors of positioning portions accumulate, increasing device complexity
Solution Approach 1:
The patent extracts the positioning function from the supporting member structure and concentrates it into separate, dedicated guide pin components. By taking out the positioning function and implementing it through simple cylindrical pins with positioning features, the structure is simplified while maintaining high positioning accuracy, avoiding the need for multiple stepped positioning portions on the supporting member
Solution Approach 2:
The positioning function is segmented into separate guide pin components rather than being integrated into the supporting member. This segmentation allows each guide pin to be independently formed with precise positioning features, reducing the accumulation of manufacturing errors that would occur with multiple stepped portions on a single component
3Device complexity
If the supporting member is directly formed on the leadframe for low pin count devices, then the structure is simplified, but it cannot fulfill requirements for high pin count COB-type packages
Solution Approach 1:
The patent designs the frame with integrally formed guide pins that create a universal mounting structure capable of accommodating both low pin count and high pin count sensor chips. The guide pins provide standardized positioning features that work across different package types, making the frame structure versatile and adaptable to various pin count requirements without needing separate supporting member designs
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 aligns the lens and sensor chip central axes, improving positioning accuracy and reducing manufacturing complexity, thereby enhancing the imaging performance and yield of the image sensor package.
Implementation Method 1
The guide pins locate oppositely inside the inner space of the frame with an interval between the tips of the guide pins substantially identical to the distance between the opposite sides of the sensor chip, wherein the central line of the interval between the tips of the guide pins defines a positioning line, which is substantially coincided with the lens central axis; wherein the tip of each guide pin is aligned with one of the opposite sides of the sensor chip respectively
Implementation Method 2
The guide pins are formed integrally inside the frame by injection molding
Data Source
AI summary
An image sensor package includes a substrate, a sensor chip, a frame, a lens element and at least a pair of guide pins. The sensor chip is mounted on the substrate, and has two opposite sides and a sensing region, which has a sensing region central axis. The frame is mounted on the substrate, and has an aperture and an inner space with the sensor chip disposed therein. The lens element is disposed inside the aperture and has a lens central axis. The guide pins locate oppositely inside the inner space of the frame with an interval between the tips of the guide pins substantially identical to the distance between the opposite sides of the sensor chip, wherein the central line of the interval between the tips of the guide pins defines a positioning line, which substantially coincides with the lens central axis; wherein the tip of each guide pin is aligned with one of the opposite sides of the sensor chip such that the positioning line is substantially coincided with the sensing region central axis.