Titanium Ribbon Laser Welding for High Density Circuit Connections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for connecting electronic circuits, such as integrated circuit chips, using bond pads are limited by density and reliability issues, leading to increased complexity and cost, especially as feature sizes decrease and input/output pin density increases, necessitating a more efficient and cost-effective solution.
Innovation Solution
The use of titanium ribbons directly welded to bonding sites on printed wiring boards and electrical components without bond pads, employing laser welding to create reliable connections that minimize space and avoid damage to underlying metal layers, allowing for higher density and reduced profile connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bond pads are used to connect ribbons to substrates or components, then reliable electrical connections are achieved, but device density is reduced and fabrication complexity increases
Solution Approach 1:
The patent removes bond pads from the connection structure, eliminating the intermediate bonding layer between ribbons and substrates/components. This extraction of the bond pad element directly increases device density while maintaining connection reliability through direct ribbon-to-target bonding.
Solution Approach 2:
The patent merges the bonding function directly into the ribbon-to-substrate or ribbon-to-component interface, eliminating the separate bond pad structure. This consolidation reduces the number of discrete elements and increases overall device density while preserving electrical connection reliability.
2Object-affected harmful factors
If bond pads are used to provide resistance to compressive forces and heat, then protection of the PWB and electrical connection is achieved, but available spatial configurations are limited
Solution Approach 1:
The patent extracts the protective function from the bond pad structure and integrates it directly into the connection interface between ribbons and substrates or components. This eliminates the need for separate bond pad elements, freeing up spatial area while maintaining protection against compressive forces and heat through the ribbon connection itself.
3Reliability
If the wire or ribbon bonding process fuses the bond pad and wire together using compressive force and thermal energy, then electrical connection is achieved, but the bond pad may be damaged
Solution Approach 1:
The patent removes the bond pad from the bonding process, eliminating the object that would otherwise be damaged by compressive force and thermal energy. The ribbon bonds directly to the substrate or component, transferring the mechanical and thermal stress away from vulnerable bond pad structures and preserving their integrity.
4Productivity
If feature sizes are reduced to increase I/O pin density, then productivity is improved, but bond pad size and pitch cannot be reduced proportionally
Solution Approach 1:
The patent extracts the bond pad element that constrains further miniaturization. By eliminating bond pads, the design allows feature sizes and pitch to be reduced proportionally with I/O pin density increases, removing the manufacturing precision bottleneck that previously limited scaling.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach eliminates the need for bond pads, reduces space requirements, minimizes labor and component costs, and simplifies manufacturing by enabling direct, reliable connections with increased density and reduced profile, suitable for implantable medical devices and other electronic applications.
Implementation Method 1
employing laser welding to create reliable connections that minimize space and avoid damage to underlying metal layers
Data Source
AI summary
Articles and methods of manufacture are provided for using laser energy in an automated bonding machine to effect laser welding of ribbons to electronic components, particularly conductive ribbons comprising titanium for microelectronic circuits. Bonding and connection of microelectronic circuits with discrete heating avoids heat damage to peripheral microelectronic components. Bonding of flexible materials and low-resistance materials are possible, and are less dependant on substrate and terminal stability in comparison to other bonding methods. The ribbon-connections can forgo the use of blocks, bond pads, and bond pad arrays for attaching ribbon to a printed wiring board. Profile height of the ribbon-connection is decreased and the density of ribbons and bonding sites can be increased compared to ribbon-connections employing bonding pads.