Wafer Level Image Sensor Packaging with Encapsulant Reinforcement
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Solution Overview
Problem
Conventional wafer level image sensor packaging structures are prone to cracking due to the thinness of the image sensing chip, and they require complex and costly processes, including the use of substrates and metal wires, which increases the risk of dust intrusion and moisture permeation.
Innovation Solution
A wafer level image sensor packaging method using a through-silicon vias (TSV) wafer that eliminates the need for substrates and metal wires, employing a transparent lid and encapsulant to reinforce the chip and prevent cracking, while simplifying the packaging process and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional COB packaging method is used with substrates and metal wires, then electrical connection is achieved, but the packaging structure becomes large in size and height
Solution Approach 1:
The patent removes substrates and metal wires from the packaging structure, retaining only the essential image sensing chip and encapsulant. This extraction eliminates unnecessary components that increase size and complexity, achieving compact packaging without compromising electrical connection functionality.
Solution Approach 2:
The patent integrates the image sensing chip directly with the encapsulant in a unified structure, eliminating the need for separate substrates and wire bonds. This merging of functions reduces the overall packaging volume and structural complexity while maintaining electrical connectivity.
2Reliability
If COB packaging process is used, then image sensing chip is attached to substrate, but the structure is susceptible to dust intrusion and moisture permeation
Solution Approach 1:
The patent uses an encapsulant that fully encapsulates the image sensing chip, creating a sealed protective barrier against dust and moisture. This thin film encapsulation provides comprehensive protection without requiring complex multi-layer substrate structures, simplifying the manufacturing process while enhancing reliability.
3Volume of moving object
If image sensing chip is made thin to reduce size, then compactness is achieved, but the chip is likely to crack during handling
Solution Approach 1:
The patent applies an encapsulant that completely surrounds the thin image sensing chip before final assembly, providing mechanical support and protection against cracking. This pre-cushioning approach allows the chip to be made extremely thin for compactness while the encapsulant prevents damage during handling and assembly operations.
4Ease of operation
If all lateral sides of image sensing chip are exposed, then access is improved, but the chip is more likely to be damaged during back-end assembly
Solution Approach 1:
The encapsulant forms a protective shell around the image sensing chip, allowing controlled access to necessary surfaces while protecting exposed lateral sides from damage during back-end assembly. This thin film enclosure maintains operational accessibility while significantly improving damage resistance.
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3
AI summary
The present invention discloses a wafer level image sensor packaging structure and a manufacturing method of the same. The manufacturing method includes the following steps: providing a silicon wafer (S100), dicing the silicon wafer (S200), providing a plurality of transparent lids (S300), fabricating a plurality of semi-finished products (S400), performing a packaging process (S500), mounting solder balls (S600), and cutting an encapsulant between the semi-finished products (S700). The manufacturing method of the invention has the advantage of being straightforward, uncomplicated, and cost-saving. Thus, the wafer level image sensor package structure is lightweight, thin, and compact. To prevent the image sensor chip from cracking on impact during handling, the encapsulant (300) will be arranged on the lateral sides of the semi-finished products (100) during the packaging process.