Semiconductor Package Carrier Opening for Stress Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor packages face stress issues due to differing coefficients of thermal expansion between the carrier and the semiconductor chip, potentially leading to delamination and device failure, and require optically transparent structures for certain applications.
Innovation Solution
A semiconductor package design featuring a carrier with an opening that relieves stress, where a semiconductor chip is attached to the carrier, and an optically transparent paste is used within the opening, covered by an encapsulation body, allowing for stress relief and optical passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a carrier and semiconductor chip are attached together to form a semiconductor package, then electrical connectivity and structural support are achieved, but stress is induced due to different coefficients of thermal expansion which may lead to delamination and device failure
Solution Approach 1:
The carrier is segmented by creating an opening (through-hole or cavity) that divides the continuous carrier structure. This segmentation allows differential thermal expansion between the carrier and semiconductor chip without transmitting stress across the entire bonding interface, thereby preventing delamination while maintaining electrical connectivity through the opening.
Solution Approach 2:
The carrier incorporates a porous or open structure via the opening, which provides stress relief pathways. This porous feature allows the carrier to accommodate thermal expansion differences without generating harmful stresses, while the opening can be filled with conductive materials to maintain electrical connectivity.
2Adaptability or versatility
If the carrier is structured to provide optical passage for optoelectronic applications, then optical functionality is enabled, but structural integrity and stress resistance may be compromised
Solution Approach 1:
The opening in the carrier serves multiple functions simultaneously: it provides stress relief for thermal expansion differences and enables optical passage for optoelectronic applications. This multi-functional design resolves the contradiction by making the same structural feature beneficial for both mechanical reliability and optical functionality.
Solution Approach 2:
The opening acts as an intermediary structure that mediates between the conflicting requirements of stress resistance and optical functionality. By filling the opening with optically transparent and conductive materials, the structure enables both stress relief and optical signal transmission without compromising either function.
3Reliability
If an opening is fabricated in the carrier to relieve stress, then stress-induced warpage and delamination are reduced, but manufacturing complexity increases
Solution Approach 1:
The opening is fabricated in the carrier before attaching the semiconductor chip. This preliminary action allows the stress relief structure to be integrated into the carrier manufacturing process itself, rather than requiring additional post-assembly steps. The opening can be created using standard semiconductor fabrication techniques such as photolithography and etching, which are already part of the carrier manufacturing workflow.
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
The design effectively reduces stress-induced warpage and delamination, while enabling optical communication in optoelectronic applications by providing a flexible packaging method that maintains electrical connectivity.
Implementation Method 1
The semiconductor chip and the carrier may exhibit different coefficients of thermal expansion (CTEs) which may induce stress in the semiconductor package
Implementation Method 2
an optically transparent paste arranged in the opening... wherein the photo active area faces the opening
Data Source
AI summary
A method of fabricating a semiconductor package comprises providing a carrier, fabricating an opening in the carrier, attaching a semiconductor chip to the carrier and fabricating an encapsulation body covering the semiconductor chip.