Off-Substrate Bond Wire Kinking for High Aspect Ratio Microcontacts
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Solution Overview
Problem
Conventional etching processes struggle to form microcontacts with a high aspect ratio and are limited in creating arrays with small pitch or spacing, making it difficult to achieve efficient interconnects in microelectronic packaging.
Innovation Solution
A method using a bonding tool to form electrically conductive leads by bonding a wire to a metal surface, clamping it, and then using a kink and tensioning mechanism to sever the wire, potentially with twisting, to create leads that extend vertically for interconnects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching processes are used to form microcontacts, then the manufacturing process is simple, but the ability to form high aspect ratio microcontacts with small pitch is limited
Solution Approach 1:
The patent replaces the conventional chemical etching process with a mechanical bonding and severing process. A bonding tool bonds a wire to a metal surface, then uses mechanical movement to impart a kink to the wire, and finally tensions or twists the wire to cause it to break at the kink location. This mechanical approach enables formation of microcontacts with high aspect ratios and small pitches that cannot be achieved through etching processes.
Solution Approach 2:
The patent changes the fundamental parameters of the microcontact formation process by transitioning from chemical removal (etching) to mechanical bonding and severing. This allows control over microcontact geometry through mechanical parameters such as bonding force, kink location, tension force, and twist amount, enabling high aspect ratios and small pitches.
2Manufacturing precision
If wire bonding method is used to form leads, then high aspect ratio and small pitch are achievable, but the process complexity increases compared to etching
Solution Approach 1:
The bonding tool is designed to perform multiple functions: bonding the wire to the metal surface, clamping the wire, imparting a kink to the wire, and tensioning or twisting the wire to sever it. This multi-functional tool consolidates what would otherwise require separate process steps and equipment, reducing overall process complexity despite the advanced capabilities required.
Solution Approach 2:
The patent combines several operations (bonding, clamping, kinking, tensioning, and severing) into a single integrated bonding tool and process flow. This merging of operations reduces the number of separate process steps and equipment requirements, making the complex process more manageable and efficient.
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 method allows for the formation of electrically conductive leads with controlled shapes and orientations, enabling efficient vertical interconnects in microelectronic assemblies, improving packaging density and high-speed operation.
Implementation Method 1
bonding a wire extending beyond a surface of a bonding tool to a metal surface
Implementation Method 2
movement of the bonding tool can impart a kink to the wire at a location where the wire is fully separated from any metal element other than the bonding tool
Implementation Method 3
The wire may then be tensioned using the bonding tool, or may also be twisted at the same time to cause the wire to break and define an end
Implementation Method 4
The wire may then be tensioned using the bonding tool, or may also be twisted at the same time to cause the wire to break and define an end
Data Source
AI summary
An electrically conductive lead is formed using a bonding tool. After bonding the wire to a metal surface and extending a length of the wire beyond the bonding tool, the wire is clamped. Movement of the bonding tool imparts a kink to the wire at a location where the wire is fully separated from any metal element other than the bonding tool. A forming element, e.g., an edge or a blade skirt provided at an exterior surface of the bonding tool can help kink the wire. Optionally, twisting the wire while tensioning the wire using the bonding tool can cause the wire to break and define an end. The lead then extends from the metal surface to the end, and may exhibit a sign of the torsional force applied thereto.