Multi-Die SiP SMT Memory Card Assembly for High Capacity
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Solution Overview
Problem
The existing portable memory devices face limitations in increasing storage capacity due to the thickness constraints of standard-sized slots in host devices, which restrict the number of memory dies that can be used within the package.
Innovation Solution
A multi-die assembly is formed by combining a System-In-Package (SiP) semiconductor package and a leadframe-based Surface Mount Technology (SMT) package, both affixed to a Printed Circuit Board (PCB), and encased within a standard-sized lid, such as an SD lid, allowing for increased storage capacity by optimizing the package thickness and layout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of memory dies is increased to increase storage capacity, then storage capacity is improved, but the package thickness exceeds the constraint of standard-sized slots
Solution Approach 1:
The patent transitions from a planar arrangement of memory dies to a three-dimensional stacked configuration. Multiple memory dies are vertically stacked and interconnected through through-silicon via (TSV) technology, allowing storage capacity to increase while maintaining a compact thickness profile that fits within standard slot constraints.
Solution Approach 2:
The patent implements a nested structure where multiple memory dies are stacked within a single package footprint. The controller die is positioned at the bottom layer, with memory dies stacked above it, creating a nested arrangement that maximizes storage capacity within the thickness limitation of standard slots.
2Reliability
If a rigid substrate with etched conductive layers is used, then electrical connections are established, but the package size and complexity increase
Solution Approach 1:
The patent extracts the traditional rigid substrate with etched conductive layers and replaces it with a simplified leadframe structure. The leadframe provides the necessary electrical connections and mechanical support with reduced complexity and smaller form factor, while maintaining reliable electrical connectivity between components.
Solution Approach 2:
The patent changes the fundamental parameter of the substrate material from rigid PCB material to flexible leadframe material. This parameter change enables a more compact package structure with reduced complexity while maintaining electrical connection reliability through the leadframe's conductive traces and solderable pads.
Data Source
AI summary
A portable memory card formed from a multi-die assembly, and methods of fabricating same, are disclosed. One such multi-die assembly includes an LGA SiP semiconductor package and a leadframe-based SMT package both affixed to a PCB. The multi-die assembly thus formed may be encased within a standard lid to form a completed portable memory card, such as a standard SD™ card. Test pads on the LGA SiP package, used for testing operation of the package after it is fabricated, may also be used for physically and electrically coupling the LGA SiP package to the PCB.