PCB Signal Line Isolation Patterns for WWAN Noise Reduction
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Solution Overview
Problem
Liquid crystal display devices in notebook computers generate WWAN noise due to electromagnetic interference from the inverter and signal lines on the printed circuit board, degrading wireless communication quality and reliability.
Innovation Solution
A printed circuit board design featuring a first and second layer with insulating layers in between, including isolation patterns between signal lines to prevent interference, achieving impedance matching and reducing WWAN noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If signal lines are densely arranged on the PCB to increase integration, then productivity and signal transmission efficiency are improved, but electromagnetic interference between adjacent signal lines increases, generating WWAN noise
Solution Approach 1:
The patent applies segmentation by dividing the continuous signal line structure into isolated segments using ground patterns positioned between adjacent signal lines. This segmentation prevents electromagnetic interference from propagating along the entire length of parallel signal lines, thereby reducing WWAN noise while maintaining high signal line integration density on the PCB.
Solution Approach 2:
The patent uses ground patterns as intermediary elements positioned between adjacent signal lines. These ground patterns act as electromagnetic shields that block interference between signal lines carrying different signals, allowing dense signal line arrangement while preventing WWAN noise generation through the mediating ground structures.
2Object-generated harmful factors
If additional noise reduction structures are added to the PCB, then WWAN noise is decreased, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent merges the noise reduction function with the existing ground reference structures already present in standard PCB designs. By combining the ground patterns that serve both as electrical references and as electromagnetic shields between signal lines, the design reduces WWAN noise without adding separate noise reduction structures, thereby avoiding increased device complexity and manufacturing cost.
Solution Approach 2:
The ground patterns in the patent serve multiple functions simultaneously: they provide electrical reference potentials for signal lines and act as electromagnetic shielding structures to prevent interference between adjacent signal lines. This multi-functionality eliminates the need for separate noise reduction components, maintaining simple PCB structure while effectively reducing WWAN noise.
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
The design effectively decreases WWAN noise, improving wireless communication conditions and reducing manufacturing costs by eliminating the need for separate noise reduction processes.
Implementation Method 1
electromagnetic waves are generated from an inverter for driving the backlight unit. Furthermore, the LCD device generates signal interference when the notebook computer accesses and communicates with a WWAN, due to various signals supplied to various components mounted on the PCB, for example, the timing controller, and signal lines formed on the PCB
Data Source
AI summary
A printed circuit board (PCB) capable of decreasing wireless wide area network (WWAN) noise generated due to internal signal interference occurring in the PCB is disclosed. The PCB printed circuit board includes a first layer, a second layer, and at least one insulating layer formed between the first and second layers. The PCB board further includes a first signal line group disposed on the first layer while including a plurality of first signal lines each supplying a first signal, isolation patterns disposed on the first layer such that the isolation patterns are arranged between adjacent ones of the first signal lines, respectively, to prevent the adjacent first signal lines from interfering with each other, and a second signal line group disposed on the second layer while including a plurality of second signal lines each supplying a second signal different from the first signal. The second signal line group corresponds to the isolation patterns.