Bump Bond Interconnect Layout for Front-Side Power Chip Current Handling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The fabrication of semiconductor power devices requires extensive processing to eliminate series resistance, leading to increased costs and complexity due to the need for metal deposition on both sides of the device, including backside contacts, which complicates current handling and increases manufacturing expenses.
Innovation Solution
The use of bump bonds as interconnects between metal lines and between the semiconductor device and the lead-frame eliminates the need for backside contacts, allowing for a simpler manufacturing process by distributing current and reducing the requirement for low resistance substrates, thereby reducing processing steps and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal deposition is performed on both front and back sides of the semiconductor device to handle high current densities, then current carrying capability is improved, but device complexity and manufacturing cost increase due to extensive processing steps
Solution Approach 1:
The patent extracts the backside contact requirement by implementing front-side-only metal deposition. The bump bonds are formed exclusively on the front side of the semiconductor device, eliminating the need for backside metal deposition and associated processing steps while maintaining current carrying capability through the lead-frame integration
Solution Approach 2:
The bump bonds serve multiple functions: they act as current carrying conductors, provide mechanical bonding between the semiconductor device and lead-frame, and serve as interconnects between separate metal lines. This multi-functionality eliminates the need for separate backside contact structures
2Reliability
If backside contacts are used to handle current, then current handling is improved, but manufacturing cost increases due to extensive processing to eliminate series resistance
Solution Approach 1:
The patent removes the backside contact processing step entirely by forming all current handling structures on the front side. The metal lines and bump bonds are deposited and formed only on the front surface, eliminating the need for backside contact fabrication and series resistance elimination processing
Solution Approach 2:
Instead of using backside contacts as conventionally done, the patent inverts the approach by implementing all current handling and bonding structures on the front side only, reversing the traditional front-side device/back-side contact architecture
3Reliability
If extensive processing is performed to eliminate series resistance, then current handling performance is improved, but manufacturing time and cost increase
Solution Approach 1:
The patent extracts and eliminates the series resistance elimination processing step by designing a structure where series resistance is inherently minimized through the front-side-only metal deposition and direct bump bond formation, removing the need for extensive additional processing
Solution Approach 2:
The metal lines and bump bonds are formed in advance during the front-side processing sequence, incorporating current handling functionality into the primary fabrication steps rather than requiring separate subsequent processing to address series resistance
Data Source
Figure 1A~1C
Figure 2A~2B
Figure 3~4
AI summary
A semiconductor power chip has a semiconductor power device formed on a semiconductor die; wherein the semiconductor power device comprises an array of conductive contact elements; a passivation layer formed over the plurality of conductive contact elements, the passivation layer comprising passivation openings over a plurality of the conductive contact elements; and an array of conductive bumps including one or more interconnection bumps, wherein each interconnection bump is formed over the passivation layer and extends into at least two of the passivation openings and into contact with at least two underlying conductive contact elements to thereby provide a conductive coupling between the at least two underlying conductive contact elements.