PCB Liquid Crystal Phase Shifter With Optical Alignment Marks

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Solution Overview

Problem

Designing and manufacturing a liquid crystal phase shifter and antenna suitable for ultra-high frequency bands is challenging due to high dielectric loss in substrate materials and inaccurate alignment issues with non-transparent PCBs, which affects signal performance in wireless communications.

Innovation Solution

The method involves using PCBs with low dielectric loss as substrates, employing metal alignment marks and through holes for precise alignment, and utilizing a CCD lens for bonding, along with transparent carrier layers to support metal alignment marks and maintain transparent mark capturing, enabling efficient assembly of liquid crystal phase shifters with improved performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If glass substrates are used in liquid crystal panels, then structural stability is improved, but dielectric loss increases at ultra-high frequencies

Engineering Contradiction:
Improvestructural stabilityVSAvoiddielectric loss
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The patent changes the substrate material from glass to PCB (printed circuit board), fundamentally altering the material parameters to reduce dielectric loss at ultra-high frequencies while maintaining structural stability through the PCB's rigid structure and controlled impedance characteristics

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structures including the PCB substrate combined with liquid crystal layers and metal patterns, creating a hybrid system that leverages the low dielectric loss of PCB materials while maintaining the functional properties of liquid crystal components

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If transparent substrates are used for mark capturing, then alignment precision is improved, but dielectric loss increases at ultra-high frequencies

Engineering Contradiction:
Improvealignment precisionVSAvoiddielectric loss
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The patent introduces transparent carrier layers as intermediary elements that support metal alignment marks during the bonding process. These carrier layers enable optical alignment through transparency while the final structure uses PCB substrates with low dielectric loss, separating the alignment function from the structural substrate

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent divides the substrate system into separate functional components: transparent carrier layers for alignment marking and PCB substrates for structural support and low dielectric loss. This segmentation allows each component to optimize its specific function without compromise

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If metal alignment marks are used on non-transparent PCBs, then dielectric loss is reduced, but alignment accuracy deteriorates due to non-transparency

Engineering Contradiction:
Improvedielectric lossVSAvoidalignment accuracy
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent uses transparent carrier layers as mediators that hold the metal alignment marks during bonding. These carrier layers are transparent to light, enabling optical alignment methods to work effectively, while the final assembled structure relies on the PCB's low dielectric loss properties for ultra-high frequency performance

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach reduces dielectric loss and ensures accurate alignment, enhancing the performance of liquid crystal antennas in ultra-high frequency bands by using PCBs with lower dielectric constants and dielectric loss, and facilitating precise bonding through metal alignment marks and transparent mark capturing.

Implementation Method 1

A first carrier layer with high light transmittance is disposed between the first metal film layer and the first substrate... A second carrier with high light transmittance is disposed between the second metal film layer and the second substrate... an oppositely bonding mechanism oppositely bonds the first substrate and the second substrate respectively via the first through hole and the second through hole by using the first alignment mark and the second alignment mark

Methodology Applied
Scientific EffectLight transmission: Light

Data Source

PatentEP3745527B1Liquid crystal phase shifter, liquid crystal antenna and manufacturing method for liquid crystal phase shifter
Publication Date: 2023.11.15 TRULY SEMICON
  • EP3745527B1 patent drawingFigure 1~3
  • EP3745527B1 patent drawingFigure 4~5
  • EP3745527B1 patent drawingFigure 6~7

AI summary

The present disclosure provides a liquid crystal phase shifter, including a first substrate and a second substrate which are disposed oppositely, and a liquid crystal layer located between the first substrate and the second substrate. A first metal film layer is disposed on a side of the first substrate facing the second substrate. A second metal film layer is disposed on a side of the second substrate facing the first substrate. The first metal film layer and the second metal film layer arc both patterned metal film layers. The first substrate and the second substrate are both PCBs. The present disclosure further provides a liquid crystal antenna, including the abovementioned liquid crystal phase shifter. The present disclosure further provides a manufacturing method of a liquid crystal phase shifter, which is used for manufacturing the abovementioned liquid crystal phase shifter. In ultra-high-frequency wireless communications, the larger a dielectric constant and a dielectric loss value of a substrate material are, the higher the dielectric loss is, and the poorer signals are. The PCBs used in the present application are used as the substrates of the liquid crystal antenna. The dielectric constants and the dielectric loss of the PCBs are less than those of a glass substrate usually used by a liquid crystal panel, so that the PCBs are lower in dielectric loss, which is favorable for improving the performance of the liquid crystal antenna in ultra-high frequency band application.