Stacked Ball Bond Interconnects for RF Impedance Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for connecting circuit boards and MMICs face challenges in impedance matching, especially at higher frequencies, which can lead to time-consuming simulations and potential re-spins due to inaccuracies or mismatches.
Innovation Solution
The use of wire bonding equipment to form stacked balls, or stud bumps, with selected impedance characteristics, allowing for precise impedance matching and adjustment by varying the number and size of the balls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional simulation methods are used to match impedance for each trace, then impedance matching accuracy can be achieved, but the process becomes time consuming and complex
Solution Approach 1:
The patent changes the physical parameters of the ball bond interconnect by varying ball diameter, ball stack height, and wire diameter to achieve impedance matching. This eliminates the need for time-consuming simulations by directly adjusting physical dimensions to match impedance requirements.
Solution Approach 2:
The patent extracts the impedance matching function from the trace design and implements it separately through ball bond interconnect structures. This allows impedance matching to be achieved independently without requiring complex simulations of the entire signal path.
2Measurement precision
If traditional simulation methods are used to model every interface, then accurate impedance matching can be achieved, but the device complexity and time consumption increase significantly
Solution Approach 1:
The patent extracts the impedance matching function from the trace design and implements it separately through ball bond interconnect structures. This allows impedance matching to be achieved independently without requiring complex simulations of the entire signal path.
Solution Approach 2:
The patent changes the physical parameters of the ball bond interconnect by varying ball diameter, ball stack height, and wire diameter to achieve impedance matching. This eliminates the need for time-consuming simulations by directly adjusting physical dimensions to match impedance requirements.
3Manufacturing precision
If fabrication errors result in out-of-specification connection impedance, then re-spins are required, but this increases time consumption and reduces productivity
Solution Approach 1:
The patent makes the ball bond interconnect dynamic and adjustable by varying ball diameter, ball stack height, and wire diameter. This allows for compensation of fabrication errors and achievement of compliant impedance matching without requiring re-spins, thereby maintaining high productivity.
4Speed
If frequency is increased to improve signal transmission, then transmission speed improves, but impedance mismatch effects increase
Solution Approach 1:
The patent changes the physical parameters of the ball bond interconnect by varying ball diameter, ball stack height, and wire diameter to achieve impedance matching. This eliminates the need for time-consuming simulations by directly adjusting physical dimensions to match impedance requirements.
Data Source
AI summary
Methods and apparatus for providing an interconnection including a stack of wirebond balls having a selected impedance. The wirebond balls may have a size, which may comprise a radius, configured for the selected impedance. The stack may comprise a number of wirebond balls configured for the selected impedance and/or may comprise a material selected for the selected impedance. In embodiments, the selected impedance is primarily resistive (e.g., 50 Ohms), such that the overall reactance is minimized.