Semiconductor Antenna Interface Using Conductive Elastomer Gaps
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Solution Overview
Problem
The presence of air gaps between the encapsulant and the antenna portion in mm-wave semiconductor devices leads to mismatch, higher insertion losses, and reduced isolation, which is problematic for communication and radar systems requiring high isolation (>30dB).
Innovation Solution
The use of a conductive elastomer as an intermediate portion to attach the antenna portion and encapsulant together, creating an electrically contiguous passage for electromagnetic radiation, thereby eliminating air gaps and associated losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an air gap is present between the radiation transmitting and receiving parts and the antenna portion, then the device structure is simpler and easier to manufacture, but this leads to mismatch, higher insertion losses and reduced isolation between transmit and receive channels
Solution Approach 1:
A dielectric layer is introduced as an intermediary between the radiation transmitting and receiving parts and the antenna portion. This dielectric layer fills the air gap and provides a controlled impedance environment that maintains electrical continuity for electromagnetic signals while allowing mechanical separation. The dielectric material with specific permittivity matches the impedance between the radiating elements and antenna, preventing signal mismatch and reducing insertion losses without complicating the manufacturing process.
2Device complexity
If an air gap is present between the radiation transmitting and receiving parts and the antenna portion, then the device structure is simpler, but this causes discontinuities in surface currents leading to mismatch and reduced isolation (>30dB requirement not met)
Solution Approach 1:
The dielectric layer serves as a mediator that maintains electromagnetic field continuity between the radiation transmitting and receiving parts and the antenna portion. By providing a controlled permittivity environment, it ensures smooth surface current transitions and prevents discontinuities that would cause signal mismatch and reduce isolation between transmit and receive channels, thereby meeting the >30dB isolation requirement without increasing device complexity.
Solution Approach 2:
The permittivity of the dielectric layer is specifically selected and tuned to match the impedance between the radiating elements and the antenna portion. By adjusting this material parameter, the electromagnetic field distribution is optimized to maintain continuous surface currents, prevent signal reflections and mismatch, and ensure high isolation between channels while keeping the device structure simple.
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 prevents mismatch and insertion losses, enhances mechanical stress absorption, improves surface flatness, and acts as a heat sink and EMC/EMI shield, ensuring high isolation and efficient radiation transmission.
Implementation Method 1
Each opening of the antenna portion and each corresponding opening of the intermediate portion forms an electrically contiguous passage for conveying the electromagnetic radiation to the electromagnetic radiation transmitting and receiving parts in the encapsulant
Implementation Method 2
The conductive elastomer can allow the antenna portion and the encapsulant to be attached together in such a way that the intermediate portion can absorb mechanical stress between the antenna portion and the encapsulant
Implementation Method 3
The conductive elastomer may also serve as a heat sink for moving heat from the encapsulant and the components located therein toward the antenna portion
Implementation Method 4
The conductive elastomer can act as a shield to prevent EMC/EMI radiation
Data Source
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AI summary
A semiconductor device and a method of making the same. The device includes an encapsulant. The device also includes a semiconductor die in the encapsulant. The device further includes electromagnetic radiation transmitting and receiving parts in the encapsulant. The device also includes an intermediate portion having a first surface and a second surface. The first surface is attached to the encapsulant. The device also includes an antenna portion attached to the second surface of the intermediate portion. The antenna portion includes one or more openings for conveying electromagnetic radiation. The intermediate portion includes one or more corresponding openings aligned with the openings of the antenna portion. Each opening of the antenna portion and each corresponding opening of the intermediate portion forms an electrically contiguous passage for conveying the electromagnetic radiation to the electromagnetic radiation transmitting and receiving parts in the encapsulant.