Image Sensor Module Encapsulation for Low Chip Stress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image sensor modules face challenges in reducing stress on the image sensor chip during encapsulant curing and require additional support structures for optical filters, which can weaken the module's rear surface, especially in downsized and multifunctional electronic devices.
Innovation Solution
The image sensor module incorporates an encapsulant that minimally covers the image sensor chip, reducing stress during curing, and includes a support structure for the housing and optical filter, using a separation space between the encapsulant and housing to enhance rear surface strength, with the encapsulant also supporting the lens holder to distribute stress effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the encapsulant covers the image sensor chip extensively, then the bonding wire is well encapsulated, but stress on the image sensor chip during curing increases
Solution Approach 1:
The encapsulant is designed to provide different coverage levels at different locations: it fully encapsulates the bonding wire in critical areas while minimally covering the image sensor chip body. This localized differentiation allows the bonding wire to be protected without subjecting the entire chip to excessive stress during curing.
2Reliability
If additional support structures are added for optical filters, then the optical filter is properly supported, but the rear surface strength of the module decreases
Solution Approach 1:
The encapsulant serves multiple functions simultaneously: it encapsulates the bonding wire, supports the optical filter, and maintains structural integrity of the module. By making the encapsulant multi-functional, additional dedicated support structures are eliminated, preventing weakening of the rear surface while still providing necessary support for the optical filter.
3Volume of moving object
If the device is downsized for compact electronic devices, then the device size is reduced, but stress management during encapsulant curing becomes more difficult
Solution Approach 1:
Instead of extensively covering the entire image sensor chip with encapsulant, the design applies encapsulant only where absolutely necessary - primarily for bonding wire encapsulation. This partial action approach reduces the overall volume of encapsulant material, thereby reducing curing stress in compact devices while still providing sufficient protection for critical components.
Data Source
AI summary
An image sensor module having an image sensor chip configured to convert light collected from an outside into an electric signal, a substrate on which the image sensor chip is installed, a bonding wire electrically connecting the image sensor chip and the substrate, an encapsulant for encapsulating the bonding wire by surrounding the side part of the image sensor chip, and a housing having a lower part spaced apart from the encapsulant and bonded on the substrate, and an upper part having an opening through which an external light is incident to the image sensor chip and supported by the encapsulant.