Multi-Architecture BGA Interconnect Layout for Package Warpage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High temperature warpage of finished electronic packages leads to increased defects in second level interconnects (SLIs) during surface mount technology (SMT) assembly, negatively impacting yield and requiring costly and complex warpage mitigation processes.
Innovation Solution
Implementing multiple different interconnect architectures with varying material compositions, diameters, and structures across different regions of the package substrate to reduce defects and accommodate warpage, while maintaining assembly complexity and cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single type of interconnect is used across the entire substrate, then manufacturing simplicity is maintained, but warpage causes increased defects such as solder bump bridging and non-contact opens
Solution Approach 1:
The patent applies local quality by implementing different interconnect architectures in different regions of the substrate. Specifically, it uses first interconnects (e.g., solder balls) in a first region and second interconnects (e.g., copper bumps) in a second region, allowing each region to be optimized for its specific warpage conditions and electrical requirements, thereby reducing defects while maintaining overall system reliability
2Manufacturing precision
If uniform interconnect architecture is used, then assembly process simplicity is maintained, but warpage leads to solder bump bridging and non-contact opens
Solution Approach 1:
Different interconnect types are deployed in different regions to address local precision requirements. The first interconnects in the first region and second interconnects in the second region are configured with different structures (solder ball vs. copper bump) to optimize placement precision for their respective locations, compensating for warpage-induced positioning errors
Solution Approach 2:
The substrate is segmented into multiple regions (first region and second region), each with its own interconnect architecture optimized for local conditions. This segmentation allows the system to handle warpage-related precision issues regionally rather than requiring a complex uniform solution across the entire substrate
3Reliability
If weighted reflow process is used to flatten package, then warpage effect is decreased, but assembly cost and process complexity increase significantly
Solution Approach 1:
The patent applies preliminary action by configuring different interconnect architectures in different regions before the assembly process begins. This pre-configuration addresses warpage-related reliability issues at the design stage, eliminating the need for costly and complex weighted reflow processes during assembly, thereby maintaining ease of manufacture while improving assembly yield
Data Source
AI summary
Embodiments disclosed herein include systems with interconnects that comprise four or more different interconnect types. In an embodiment, an apparatus comprises a substrate and a ball grid array across a surface of the substrate. In an embodiment, the ball grid array comprises first interconnects in a first region of the ball grid array, second interconnects in a second region of the ball grid array, third interconnects in a third region of the ball grid array, and fourth interconnects in a fourth region of the ball grid array. In an embodiment, the first interconnects, the second interconnects, the third interconnects, and the fourth interconnects all have a difference in one or more of a composition, a dimension, and a structure.