Pre-patterned Fine-pitch Bond Pads for High-density Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current interconnect configurations for stacked dies in electronic packaging are not suitable for high density and high performance packages, as they require high temperature processes, are costly, and face limitations in pitch and size, making them unsuitable for high I/O components and small form factors.
Innovation Solution
The use of pre-patterned fine-pitch bond pads for wire bonding, which eliminates the need for redistribution layers, allows for quicker assembly, enhanced signal integrity, and improved thermal management, enabling high I/O density and performance in electronic packages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If through mold vias are used to connect stacked dies, then electrical coupling is achieved, but pitch and size are constrained by part thickness, limiting high I/O components and small form factor applications
Solution Approach 1:
The patent transitions from vertical through-mold via connections to a hybrid approach where wire bonds connect dies to bond pads on the mold surface. This dimensional change allows connections to extend beyond the constrained thickness of the mold, enabling finer pitch and smaller form factors while accommodating high I/O components.
2Reliability
If vertical wires are used to couple stacked dies to RDL, then electrical coupling is achieved, but high temperature process and special processing increase costs and variability
Solution Approach 1:
The patent extracts the wire bonding process from the high-temperature RDL manufacturing sequence and performs it separately at lower temperatures. The bond pads are pre-formed on the mold surface before die stacking, allowing wire bonds to be made in a controlled, lower-temperature process that reduces variability and cost.
Solution Approach 2:
The bond pads are pre-patterned and pre-formed on the mold surface before the die stacking and wire bonding operations. This preliminary action allows for precise positioning and reduces variability in the final wire bond connections, while enabling a simpler, lower-temperature manufacturing process.
3Quantity of substance
If stacked dies are packaged in high density configuration, then memory density increases, but thermal management and signal integrity become more challenging
Solution Approach 1:
The patent segments the connection interface into discrete bond pads distributed on the mold surface, rather than using concentrated via structures. This segmentation improves heat dissipation by distributing thermal load across multiple contact points and enhances signal integrity by providing dedicated, well-defined connection paths for each I/O.
Data Source
AI summary
Embodiments disclosed herein include electronic packages and methods of forming such electronic packages. In an embodiment, the electronic package comprises, a package substrate, a die stack on the package substrate, and a mold layer encapsulating the die stack. In an embodiment, the electronic package further comprises a bond pad having a first surface and a second surface, where the die stack is electrically coupled to the first surface of the bond pad with a wire bond, and the second surface of the bond pad is substantially coplanar with a surface of the mold layer.