Vertical-Wire Memory Die Stacking for Compact Package-in-Package Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in packaging memory-die stacks for computing devices such as memory modules, smartphones, and tablets is the limited available space, which restricts size reduction and poses challenges for effective packaging solutions.
Innovation Solution
A vertical wire package-in-package (VWPiP) apparatus is developed, utilizing a memory-die stack with vertical bond wires that are anchored to a spacer and encapsulated in a matrix, allowing for high-capacity storage with a stair-step configuration and redistribution layers to facilitate efficient assembly and testing before integration into a quad-pack package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If memory-die stacks are assembled with vertical bond wires in a package-in-package configuration, then storage capacity is increased and space utilization is improved, but manufacturing complexity and assembly difficulty increase
Solution Approach 1:
The patent implements package-in-package (PiP) configuration where a first memory module is nested within a second memory module, allowing multiple memory dice to be stacked vertically. This nesting approach increases storage capacity by utilizing three-dimensional space while maintaining a compact footprint, directly addressing the contradiction between increasing storage capacity and managing assembly complexity
Solution Approach 2:
The patent transitions from traditional planar packaging to vertical three-dimensional packaging by implementing stair-step configurations and vertical bond wires. Memory dice are arranged in multiple vertical layers (first stack and second stack at different heights), enabling high-capacity storage in a limited footprint while managing complexity through systematic vertical organization
2Volume of moving object
If vertical bond wires are used to connect memory dice in stacked configuration, then space efficiency is improved and storage density increases, but manufacturing precision requirements and process difficulty increase
Solution Approach 1:
The patent introduces spacers as intermediary components between memory dice in the stack. These spacers provide mechanical support, maintain precise spacing, and facilitate wire bonding operations. The spacers act as mediators that reduce the direct precision requirements for wire bonding by providing a structured framework, thus enabling vertical stacking while managing manufacturing precision challenges
Solution Approach 2:
The patent implements preliminary assembly steps where memory dice are stacked and secured with spacers before wire bonding. This preliminary structuring establishes a stable framework that simplifies subsequent wire bonding operations, reducing the precision burden during the critical wire bonding process while achieving compact vertical integration
3Quantity of substance
If multiple memory modules are assembled in quad-pack configuration, then storage capacity is increased, but testing complexity and assembly time increase
Solution Approach 1:
The patent performs testing on individual memory modules before final assembly into the quad-pack configuration. This preliminary testing approach identifies and isolates defects early in the manufacturing process, preventing cascading failures and reducing rework time during final assembly. The known-good module approach streamlines the overall assembly and testing timeline while achieving high storage capacity
Data Source
AI summary
A vertical-wire package-in-package includes at least two memory-die stacks that form respective memory modules that are stacked vertically on a bond-wire board. Each memory die in the memory-die stack includes a vertical bond wire that emerges from a matrix for connection. The matrix encloses the memory-die stack, the spacer, and a redistribution layer. At least two memory modules are assembled in a vertical-wire package-in-package.