Aligned Solder Ball and Bump Patterns for Power Distribution
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Solution Overview
Problem
The conventional configuration of solder balls on a substrate and bumps on a semiconductor die results in long current paths, higher parasitic inductance, uneven current distribution, and high-voltage drops due to varying lengths of current paths between VDD solder balls and bumps, leading to increased on-die capacitance.
Innovation Solution
The patterns of solder balls on the substrate and solder bumps on the semiconductor die are redesigned to be complementary and aligned, with VDD balls and bumps arranged in alternating rows to minimize current paths and ensure uniform lengths, reducing parasitic inductance and voltage irregularities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solder balls are arranged around the outer periphery and bumps in alternating rows, then the substrate can be soldered to host device and signals can be transferred, but the current path length becomes long and uneven, resulting in higher parasitic inductance and voltage drops
Solution Approach 1:
The patent applies asymmetry by changing from traditional alternating row patterns to aligned patterns where VDD balls are positioned directly beneath corresponding VDD bumps. This asymmetric arrangement optimizes current path geometry, reducing length and uniformity variations, thereby minimizing parasitic inductance and voltage drops while maintaining reliable signal transfer.
Solution Approach 2:
The aligned configuration of VDD balls and bumps creates more uniform current paths with equal lengths from each ball to its corresponding bump. This equipotential approach ensures that all VDD current paths experience similar electrical characteristics, reducing voltage drops and improving power distribution uniformity across the die.
2Ease of manufacture
If current paths between VDD solder balls and bumps are long and uneven, then manufacturing is simpler with conventional patterns, but on-die capacitance increases and voltage distribution becomes uneven
Solution Approach 1:
The patent implements asymmetry in the ball-bump alignment pattern, deviating from conventional symmetric alternating rows. This asymmetric design directly addresses voltage distribution uniformity by ensuring equal current path lengths, achieving precise voltage control across the die while remaining manufacturable with standard PCB and die attachment processes.
3Object-affected harmful factors
If solder balls and bumps are aligned to minimize current paths, then parasitic inductance and voltage irregularities are reduced, but the configuration becomes more complex compared to conventional alternating patterns
Solution Approach 1:
The patent applies equipotentiality through aligned ball-bump configurations that create uniform current paths. This approach reduces voltage irregularities by ensuring all VDD paths have equal lengths and similar electrical characteristics. The pattern complexity increase is minimal and can be implemented through straightforward design rules in standard manufacturing processes.
Data Source
AI summary
A semiconductor device is disclosed including a semiconductor die mounted on a substrate. The substrate includes a pattern of solder balls which is complementary and aligned to a pattern of solder bumps on the semiconductor die. These complementary and aligned patterns of solder balls and solder bumps minimize the lengths of current paths between the solder balls and solder bumps, and provide current paths between the solder balls and solder bumps of relatively uniform lengths.