Planar tuning lines for RF power package impedance matching
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Solution Overview
Problem
Conventional wire bonding for impedance matching in RF power packages is complex, expensive, and difficult to maintain consistency across multiple parts/wafers, requiring specialized equipment and costly low-loss materials.
Innovation Solution
The use of optically defined planar tuning lines on a substrate to transform impedance, eliminating the need for wire bonds and providing consistent and cost-effective impedance matching/transformation by routing signals and power between packaging components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wire bonds are used for impedance matching, then impedance transformation can be achieved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent replaces the mechanical wire bonding system with a planar transmission line system fabricated using standard PCB techniques. The impedance matching function previously achieved through mechanical wire bonds is now accomplished through carefully designed planar trace geometries with specific characteristic impedances, eliminating the need for specialized wire bonding equipment and procedures.
Solution Approach 2:
The patent uses planar transmission lines that replicate the impedance transformation function of wire bonds through a different physical implementation. The planar lines are designed with specific geometric parameters (width, spacing, substrate thickness) to achieve the same electrical function as the wire bonds, providing a cost-effective alternative that maintains performance.
2Manufacturing precision
If wire bonds are used for impedance matching, then impedance transformation can be achieved, but the manufacturing cost increases
Solution Approach 1:
The patent replaces the expensive mechanical wire bonding process with planar transmission lines fabricated using standard PCB manufacturing techniques such as copper trace deposition and etching. This substitution eliminates the need for specialized wire bonding equipment, gold or low-loss wire bond materials, and precise assembly procedures, significantly reducing manufacturing costs while maintaining impedance matching precision.
Solution Approach 2:
The patent employs standard copper traces on PCB substrates instead of expensive gold wire bonds. The planar transmission lines are fabricated using conventional, cost-effective PCB manufacturing processes that are already widely available in the industry, making the solution economically viable for mass production.
3Manufacturing precision
If wire bonds are used for impedance matching, then impedance transformation can be achieved, but consistency across multiple parts deteriorates
Solution Approach 1:
The patent replaces the mechanical wire bonding process with planar transmission lines fabricated using standard PCB techniques. This substitution eliminates the variability introduced by manual or automated wire bonding processes, such as bond strength variations, wire tension inconsistencies, and alignment errors. The planar lines provide uniform, repeatable impedance characteristics across all manufactured parts.
4Manufacturing precision
If wire bonds are used for impedance matching, then impedance transformation can be achieved, but specialized equipment and procedures are required
Solution Approach 1:
The patent replaces the specialized wire bonding equipment and procedures with standard PCB manufacturing processes. The impedance matching function is achieved through planar transmission lines fabricated using conventional copper trace deposition, patterning, and substrate lamination techniques that are already widely available in the electronics manufacturing industry, eliminating the need for specialized wire bonding machinery and expert assembly procedures.
Data Source
AI summary
An RF power package includes a substrate having a metallized part and an insulating part, an RF power transistor die embedded in or attached to the substrate, the RF power transistor die having a die input terminal, a die output terminal, an input impedance and an output impedance, a package input terminal formed in the metallized part or attached to the insulating part of the substrate, a package output terminal formed in the metallized part or attached to the insulating part of the substrate, and a first plurality of planar tuning lines formed in the metallized part of the substrate and electrically connecting the die output terminal to the package output terminal. The first plurality of planar tuning lines is shaped so as to transform the output impedance at the die output terminal to a higher target level at the package output terminal.