Bonding Wire Impedance Matching Circuit Using Vertical Transformer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional impedance matching methods for millimeter bands, particularly for bonding wires, face challenges in achieving effective impedance matching without using very thin transmission lines or specialized antennas, especially when dealing with circuits behind chips or other transmission lines, leading to significant transmission loss and performance degradation.
Innovation Solution
An impedance matching circuit utilizing a transformer arranged inside a dielectric substrate, overlapping with bonding pad and transmission line areas, which generates series and parallel capacitance components and forms an LC resonation circuit, allowing for impedance matching without thin transmission lines or specialized antennas, and is produced using the LTCC method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional LC transmission lines are used for impedance matching, then impedance matching can be achieved, but very thin transmission lines of several to dozens of μm are required which are difficult to embody in actual passive environment
Solution Approach 1:
The patent introduces a vertical dimension by placing a second pad inside the dielectric substrate overlapping with the first pad area and transmission line end, creating a three-dimensional impedance matching structure. This vertical stacking approach replaces the conventional planar thin transmission line design, allowing impedance matching without requiring extremely thin lateral transmission lines that are difficult to manufacture.
2Adaptability or versatility
If bonding wire length increases to hundreds of μm, then connection flexibility improves, but the impedance (Lp) required in the actual impedance compensation circuit becomes greater requiring very thin transmission lines
Solution Approach 1:
By transitioning from a two-dimensional planar transmission line design to a three-dimensional structure with overlapping pads in vertical layers, the patent enables the use of longer bonding wires (hundreds of μm) without requiring imprecisely thin transmission lines. The vertical overlap configuration provides the necessary impedance transformation without lateral dimension constraints.
3Device complexity
If antenna impedance design is used to match bonding wire impedance, then matching circuit size is minimized, but it is difficult to apply to cases where circuits behind chips are transmission lines and not antennas
Solution Approach 1:
The patent creates a universal impedance matching structure using overlapping pads and transmission line configuration that can serve multiple functions: it works with antennas, transmission lines, and various chip circuits. The second pad inside the dielectric substrate overlapping with the first pad area creates a general-purpose matching structure applicable to different circuit configurations behind chips, not limited to antenna-specific designs.
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 solution enables minimal insertion loss and effective signal transmission across various millimeter bands, applicable to both antennas and chip circuits, without requiring thin transmission lines or specialized antennas, thus addressing the limitations of existing methods.
Implementation Method 1
the second pad may generate a series capacitance component with the first pad, generate a parallel capacitance component with the ground
Implementation Method 2
the first pad, second pad, and one end of the transmission line may form an LC resonation circuit
Implementation Method 3
a bonding wire impedance matching circuit may include a dielectric substrate; a ground arranged on a lower surface of the dielectric substrate; a first pad which is arranged on an upper surface of the dielectric substrate, and to which bonding wires is connected; a transmission line which is arranged on an upper surface of the dielectric substrate, and of which an end is arranged by a certain distance from the first pad; and a second pad which is arranged inside the dielectric substrate, and is arranged to overlap with the first pad area and one end area of the transmission line
Data Source
AI summary
An impedance matching circuit is provided. The present impedance matching circuit is able to match impedance using a transformer which is arranged inside a dielectric substrate and arranged to overlap with a bonding pad area and an end of a transmission line, thereby enabling transmitting signals at a desired frequency with a minimum insertion loss without using a very thin transmission line which is several to dozens of μm wide or specially designed antennas in order to compensate for inductance. Thus, the present impedance matching circuit may be applied to various millimeter bands.