Stacked Die Package System Separate Testing Yield
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Solution Overview
Problem
The challenge in integrated circuit (IC) package miniaturization is the low final test yield of stacked die packages due to handling difficulties and the inability to separately test individual dies, leading to increased costs and reduced semiconductor module efficiency.
Innovation Solution
A stacked die package system is developed, comprising a bottom and top package with substrates and dies electrically connected via wires, encapsulated for protection, and connected using solder balls, allowing for separate testing and efficient use of space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If dies are stacked in a stacked die package system to increase die density and reduce footprint, then the number of electronic devices within smaller areas is improved, but the final test yield deteriorates due to inability to separately test individual dies
Solution Approach 1:
The patent divides the stacked die package into separable segments (individual dies on separate substrates) that can be tested independently before final assembly. This allows quality verification of each die separately, preventing defective dies from compromising the entire package yield while maintaining high die density in the final stacked configuration.
Solution Approach 2:
The patent implements preliminary testing of individual dies on their respective substrates before the stacking assembly process. This preliminary quality assurance action enables identification and removal of defective dies prior to final package formation, thereby improving overall package yield while achieving high die density through subsequent stacking of only verified good dies.
2Length of stationary object
If dies are stacked with adhesive or spacer to reduce package thickness, then the required interconnect density is reduced, but handling difficulties increase making separate testing impossible
Solution Approach 1:
The patent maintains segmentation of dies on separate substrates with adhesive or spacer layers that provide mechanical separation and handling capability. This segmentation allows each die-substrate assembly to be handled and tested independently before final stacking, overcoming the handling difficulties that would arise from pre-assembled stacked configurations.
Solution Approach 2:
The patent uses substrates as intermediary carriers between individual dies and the final stacked package. These substrates provide a stable platform for handling and testing individual dies, acting as mediators that enable separate testing while the adhesive or spacer layers facilitate the eventual stacking process to achieve reduced package thickness.
3Quantity of substance
If multiple dies are integrated in a horizontal plane to increase device count, then the number of electronic devices is improved, but the area required increases
Solution Approach 1:
The patent transitions from two-dimensional horizontal integration of multiple dies to three-dimensional vertical stacking configuration. By arranging dies in stacked layers along the vertical dimension rather than spreading them horizontally, the system achieves higher device count within a smaller footprint area, effectively resolving the contradiction between quantity of devices and package area.
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
This approach enhances the testing efficiency of individual dies, improves yield, and reduces costs by enabling separate testing before assembly, thus addressing the limitations of existing miniaturized IC packages.
Implementation Method 1
connected using solder balls
Data Source
AI summary
A stacked die package system including forming a bottom package including a bottom substrate and a bottom die mounted and electrically connected under the bottom substrate and forming a top package including a top substrate and a top die mounted and electrically connected over the top substrate. Mounting the top package by the top substrate over the bottom substrate and electrically connecting the bottom and top substrates. Mounting system electrical connectors under the bottom substrate adjacent the bottom die.