3D IC Packaging with Stair-Structure Interconnects
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Solution Overview
Problem
Conventional semiconductor package structures face challenges in miniaturization, reliability, and cost-effectiveness, particularly in portable devices, where they require smaller, thinner, and more densely packed integrated circuits with improved yield and performance.
Innovation Solution
The method involves a carrier with contact pads, multiple resist layers with specific openings, and internal interconnects that fill these openings without gaps, forming a stair structure for enhanced connectivity and underfill formation, using resist layers made of non-conductive materials like resins or polymers to protect against shorting and facilitate robust joint formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional semiconductor package structures are used, then manufacturing is simpler, but miniaturization and packaging density are limited
Solution Approach 1:
The patent implements package-on-package (POP) architecture where multiple integrated circuit packages are stacked vertically, with upper packages nested above lower packages. This nesting approach achieves miniaturization by utilizing the vertical dimension, reducing the horizontal footprint while maintaining high component density. The interconnect structures penetrate through multiple package layers to establish electrical connections between stacked packages.
Solution Approach 2:
The invention transitions from conventional two-dimensional planar packaging to three-dimensional vertical stacking. By introducing the vertical dimension with multiple package layers stacked above each other, the system achieves higher packaging density without increasing the horizontal area, effectively resolving the contradiction between miniaturization and structural complexity.
2Quantity of substance
If package-on-package (POP) designs are used, then packaging density increases, but reliability challenges arise
Solution Approach 1:
The patent incorporates underfill material applied beneath the integrated circuits before final packaging. This preliminary action prevents delamination at the interfaces between stacked packages by providing adhesive support, thereby enhancing reliability while maintaining the high component density achieved through POP architecture.
Solution Approach 2:
The invention introduces interconnect structures that penetrate through multiple package layers as intermediary elements. These interconnects serve as mediators establishing reliable electrical pathways between upper and lower packages, reducing signal integrity issues and improving overall package reliability while enabling high component density.
3Volume of moving object
If miniaturization is pursued, then device size decreases, but manufacturing precision requirements increase
Solution Approach 1:
The patent divides the interconnect structure into multiple segmented components distributed across different package layers. This segmentation allows for modular manufacturing and assembly, where each segment can be precisely positioned and connected sequentially, reducing the cumulative alignment errors that would occur in a single continuous interconnect spanning multiple layers.
Solution Approach 2:
The invention implements localized alignment features and registration marks at each package interface to ensure precise interconnect alignment. By providing local quality enhancements at critical bonding regions rather than requiring uniform precision throughout the entire structure, the system achieves accurate alignment while maintaining manufacturability.
4Reliability
If resist layers with openings are used for interconnect formation, then connectivity is improved, but delamination risks increase
Solution Approach 1:
The patent applies underfill material to the substrate before mounting the integrated circuits and forming the resist layer structures. This preliminary action provides mechanical support and adhesive reinforcement to the resist layers, preventing delamination that could occur during subsequent processing steps while maintaining the connectivity benefits of the resist opening structure.
Solution Approach 2:
The invention uses composite material structures combining resist layers with supporting underfill materials and adhesive layers. This composite approach maintains the electrical connectivity function of the resist openings while the additional material layers provide mechanical strength and delamination resistance, resolving the contradiction between connectivity and adhesion.
Data Source
AI summary
A method of manufacture of an integrated circuit packaging system includes: providing a carrier having a contact pad; forming a first resist layer, having a first resist opening, over the carrier and the contact pad, the first resist opening partially exposing the first contact pad; forming a second resist layer, having a second resist opening over the first resist opening, the second resist opening partially exposing the first resist layer; mounting an integrated circuit over the carrier; and forming an internal interconnect between the integrated circuit and the carrier, the internal interconnect filling the second resist opening with no space between the second resist layer in the second resist opening.