Semiconductor Package Stiffener With Dummy Corner Connectors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor packages face reliability issues due to flexing or bowing under temperature changes, leading to stress and damage at solder connections, particularly at corner regions, which can impair functionality and reduce the lifetime of solder joints.
Innovation Solution
A stiffener is integrated onto the semiconductor package, featuring a connection portion that overhangs the substrate and extends toward the bottom surface, with a second array of connectors providing dummy connections to enhance mechanical strength and distribute stress, thereby reducing damage to active connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If connectors are extended to the corners of the substrate, then routing is improved and connection density is increased, but stress concentration and damage risk at corner solder connections increase
Solution Approach 1:
The connector array is segmented into active connectors on the substrate and dummy connectors on the stiffener. This segmentation allows the active connectors to be positioned optimally for routing while the dummy connectors absorb stress, preventing corner damage and improving overall reliability.
Solution Approach 2:
The stiffener acts as an intermediary element between the substrate and the circuit board. It provides a platform for dummy connectors that mediate the stress distribution, protecting the active connectors on the substrate from excessive stress while maintaining routing efficiency.
2Reliability
If the package structure is made more rigid to resist flexing, then solder joint reliability is improved, but device complexity increases
Solution Approach 1:
The stiffener is merged with the substrate to form an integrated package structure. This combination provides the necessary rigidity to resist flexing and protect solder joints without requiring separate complex support structures, thereby improving reliability while controlling complexity.
Solution Approach 2:
The stiffener serves multiple functions: it provides mechanical support to resist flexing, holds dummy connectors for stress distribution, and maintains coplanar alignment with the substrate. This multi-functionality improves solder joint reliability without proportionally increasing device complexity.
3Reliability
If dummy connectors are added to the stiffener, then stress distribution is improved and active connection protection is enhanced, but manufacturing complexity increases
Solution Approach 1:
The dummy connectors are preliminarily positioned on the stiffener during the packaging process. This preliminary action establishes the stress distribution network before the package is subjected to operational stresses, enhancing protection for active connections while streamlining the manufacturing process.
Solution Approach 2:
The addition of dummy connectors changes the mechanical parameters of the package structure, specifically the stress distribution characteristics. This parameter change improves reliability by distributing stresses away from active connections, while the standardized implementation keeps manufacturing complexity manageable.
Data Source
AI summary
In some implementations, an apparatus includes a substrate having a top surface and a bottom surface, a first array of connectors on the bottom surface of the substrate, a semiconductor device disposed on the top surface of the substrate, and a stiffener having a connection portion that extends along at least a portion of a side edge of the substrate. A bottom surface of the connection portion may be coplanar with the bottom surface of the substrate. The apparatus may include a second array of connectors on the bottom surface of the connection portion.