Image Sensor Module With Package Cavity And RDL
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Solution Overview
Problem
Conventional image sensor module packaging techniques are limited by wire bonding, leading to larger sizes and higher costs, and fail to meet the demands of miniaturization and high-density device requirements, especially in digital cameras where multiple lenses are needed for minimal distortion and chromatic aberration.
Innovation Solution
An image sensor module with a substrate having a package receiving cavity and conductive traces, where a die with a micro lens is attached, and a dielectric layer is formed with openings to expose the micro lens area, allowing for a re-distribution layer (RDL) and solder bridges to connect the die to the substrate, enabling a super thin, re-workable, and cost-effective package with a small footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wire bonding is used to connect CCD or CMOS chip to substrate, then electrical connection is achieved, but the size of the sensor module increases and manufacturing complexity increases
Solution Approach 1:
The patent extracts and eliminates the wire bonding process from the sensor module assembly. Instead of using separate metal wires to connect the chip to the substrate, the invention directly bonds the chip pads to the substrate contact pads through die bonding, removing the intermediate wire bonding step and reducing overall module size and manufacturing complexity
Solution Approach 2:
The patent merges the electrical connection function with the mechanical bonding process. By integrating the bonding pads and contact pads directly into the substrate structure, the invention combines what were previously separate functions (wire bonding for electrical connection and die bonding for mechanical support) into a single integrated bonding process
2Reliability
If traditional resin packaging method is used, then device protection is achieved, but the package size is large and manufacturing time is long
Solution Approach 1:
The patent applies preliminary action by pre-forming contact pads on the substrate before mounting the die. This allows the bonding process to occur in a single step without requiring subsequent wire bonding or complex packaging operations, significantly reducing manufacturing time while maintaining device protection
Solution Approach 2:
The invention changes the packaging approach from traditional resin encapsulation to a direct bond method where the substrate itself serves as the package structure. This parameter change in packaging methodology eliminates the need for additional packaging materials and steps, reducing both size and manufacturing time while maintaining reliability
3Manufacturing precision
If multiple lenses are arranged to generate a flat optical plane, then image quality with minimal distortion is achieved, but the number of expensive optical elements increases
Solution Approach 1:
The patent applies multi-functionality by making the substrate serve multiple functions: it provides mechanical support for the die, establishes electrical connections through integrated contact pads, and creates the optical plane for multiple lenses. This eliminates the need for separate structural components and reduces overall device complexity while maintaining image quality
4Reliability
If conventional package techniques (lead frame, flex, rigid package) are used, then device protection and support are achieved, but the manufacturing process is time-consuming and cannot meet high-density device requirements
Solution Approach 1:
The patent merges the functions of lead frame packages (structural support and electrical connection) into a single substrate structure. The substrate simultaneously provides mechanical support, electrical pathways through integrated contact pads, and mounting surfaces for the die, eliminating the need for separate lead frames and reducing manufacturing steps
Solution Approach 2:
The invention extracts and eliminates the lead frame component from the package structure. By directly integrating all necessary functions into the substrate, the patent removes the time-consuming lead frame attachment and wire bonding processes, significantly improving manufacturing efficiency for high-density devices
Data Source
AI summary
The present invention provides an image sensor module having build-in package cavity and the Method of the same. An image sensor module structure comprising a substrate with a package receiving cavity formed within an upper surface of the substrate and conductive traces within the substrate, and a package having a die with a micro lens disposed within the package receiving cavity. A dielectric layer is formed on the package and the substrate, a re-distribution conductive layer (RDL) is formed on the dielectric layer, wherein the RDL is coupled to the die and the conductive traces and the dielectric layer has an opening to expose the micro lens. A lens holder is attached on the substrate and the lens holder has a lens attached an upper portion of the lens holder. A filter is attached between the lens and the micro lens. The structure further comprises a passive device on the upper surface of the substrate within the lens holder.