Stack Module Selection Terminal Interconnection Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing stacked semiconductor structures face challenges in forming pads or interconnections on both surfaces of semiconductor chips, particularly when the chips are warped due to thermal transients, leading to reliability issues and increased manufacturing complexity.
Innovation Solution
A stack module design where unit substrates are alternately stacked with first and second selection lines electrically connected to selection terminals, allowing for simplified and cost-effective interconnection by using only two kinds of interconnection structures, which reduces manufacturing costs and maintains high connection reliability even when substrates are warped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pads or interconnections are formed on both surfaces of semiconductor chips to enable stacked structure, then electrical connection between stacked chips is achieved, but manufacturing complexity and cost increase significantly
Solution Approach 1:
The patent divides the interconnection function into two parts: through-holes providing vertical electrical connection through the substrate, and surface pads providing horizontal connection on the top surface. This segmentation eliminates the need for rear surface pads, simplifying manufacturing while maintaining connection reliability.
Solution Approach 2:
The patent transitions from a two-dimensional surface pad arrangement to a three-dimensional structure by introducing through-holes that extend vertically through the substrate. This dimensional change allows electrical connection without requiring rear surface pads, reducing manufacturing complexity.
2Reliability
If through-holes are formed to connect stacked substrates, then electrical connection is achieved, but manufacturing precision requirements increase
Solution Approach 1:
The patent introduces a ball structure at the bottom of through-holes as an intermediary element that facilitates alignment and connection between stacked substrates. This ball structure compensates for minor misalignments, reducing the precision requirements for through-hole formation while ensuring reliable electrical connection.
3Ease of manufacture
If selection terminals are positioned to avoid through-holes, then manufacturing simplicity is improved, but electrical connection reliability may be compromised
Solution Approach 1:
The patent applies different functional qualities to different regions of the substrate: through-holes are concentrated in specific areas for electrical connection, while selection terminals are positioned in regions free of through-holes for reliable signal transmission. This local differentiation optimizes both manufacturing simplicity and connection reliability.
Data Source
AI summary
Provided are a high reliability stack module fabricated at low cost by using simplified processes, a card using the stack module, and a system using the stack module. In the stack module, unit substrates are stacked with respect to each other and each unit substrate includes a selection terminal. First selection lines are electrically connected to selection terminals of first unit substrates disposed in odd-number layers, pass through some of the unit substrates, and extend to a lowermost substrate of the unit substrates. Second selection lines are electrically connected to selection terminals of second unit substrates disposed in even-number layers, pass through some of the unit substrates, and extend to the lowermost substrate of the unit substrates. The selection terminal is disposed between the first selection lines and the second selection lines.