Thin-Film Transistor (TFT) Array: Dynamic Range >14 bits

Q: What is the role of the TFT Array in a Flat Panel Detector?

The TFT Array serves as the active readout layer that converts X-ray-induced signals (via a scintillator) into electrical charges at each pixel, which are then sequentially read out to form a digital image.

Q: Why is amorphous silicon commonly used in TFT Arrays for medical imaging?

Amorphous silicon (a-Si) is preferred due to its ability to be deposited uniformly over large glass substrates at relatively low temperatures, its good electronic properties for TFTs and photodiodes, and its cost-effectiveness for large-area applications.

Q: How does pixel pitch affect image quality in a TFT Array?

Smaller pixel pitch increases spatial resolution, allowing finer details to be resolved in the image. However, it may reduce the fill factor and charge collection efficiency, requiring a balance based on the clinical application (e.g., mammography vs. general radiography).

Component Specifications

Definition

A Thin-Film Transistor (TFT) Array is a sophisticated electronic matrix composed of millions of individual TFT pixels fabricated on a glass substrate. In Flat Panel Detectors (FPDs) for medical imaging, it functions as the active readout layer. Each pixel contains a photodiode (typically amorphous silicon) that converts incoming X-ray photons into electrical charge, and a TFT switch that controls the readout of this charge to external circuitry. The array's high density and precision enable the capture of high-resolution digital X-ray images with minimal noise and rapid frame rates.

Working Principle

The TFT Array operates on the principle of photoelectric conversion and active matrix addressing. When X-rays strike the scintillator layer above the array, visible light is produced. This light is absorbed by the photodiodes in each pixel, generating electron-hole pairs and storing electrical charge. During readout, a gate driver sequentially activates rows of TFTs. When a TFT is switched on, the stored charge in its corresponding photodiode is transferred through the TFT to a data line, where it is amplified and digitized by external readout electronics. This process converts the spatial distribution of X-ray intensity into a digital image matrix.

Materials

Glass substrate (e.g., Corning Eagle XG), amorphous silicon (a-Si) for TFTs and photodiodes, silicon nitride (SiNx) for gate dielectric and passivation layers, metal layers (e.g., molybdenum, aluminum) for electrodes and interconnects.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Array Size	Up to 43 cm x 43 cm for medical panels
Fill Factor	>70%
Pixel Pitch	100-200 μm
Dark Current	<1 pA per pixel
Readout Time	<200 ms for full frame
Dynamic Range	>14 bits
Number Of Pixels	Up to 9 megapixels (e.g., 3000 x 3000)

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

ISO 9236-1, IEC 62220-1, DIN 6868-57

Parent Products

This component is used in the following industrial products

Flat Panel Detector

A digital X-ray imaging component that converts X-ray radiation into electronic signals for medical imaging.

View Product Details

Engineering Analysis

Risks & Mitigation

Delamination of layers due to thermal stress
Pixel defects (dead or stuck pixels) affecting image quality
Degradation of amorphous silicon performance over time
Electrostatic discharge (ESD) damage during handling

FMEA Triads

Trigger: Contamination during fabrication or thermal mismatch between materials.
Failure: Layer delamination leading to open circuits or increased noise.
Mitigation: Implement cleanroom protocols, use materials with matched thermal expansion coefficients, and apply robust passivation layers.

Trigger: Manufacturing defects or prolonged exposure to high radiation doses.
Failure: Pixel defects (dead/stuck pixels) causing artifacts in the medical image.
Mitigation: Employ rigorous testing and pixel correction algorithms, design with radiation-hard materials, and follow dose management protocols.

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

Pixel pitch uniformity within ±2%, geometric distortion <0.5% over entire array, defect pixel clusters limited to <5 contiguous pixels.

Test Method

ISO 9236-1 for detective quantum efficiency (DQE), IEC 62220-1 for digital X-ray imaging performance, visual inspection for defects, electrical testing of TFT characteristics.

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Thin-Film Transistor (TFT) Array

Manufacturer profiles associated with Thin-Film Transistor (TFT) Array.

Sourcing Thin-Film Transistor (TFT) Array from China?

Tell us your specification and target quantity — we will match it against manufacturer records and come back with the factories that fit.

Request manufacturers We manufacture this

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

Related Components

Dielectric Layer

Insulating layer in surface mount capacitors that stores electrical energy through polarization.

Optical Window

Transparent optical component for light transmission in polycarbonate lens housings

PCB Substrate

PCB substrate is the foundational insulating layer that provides mechanical support and electrical connectivity for electronic components in high-speed memory modules.

Edge Connector

Edge connector is a printed circuit board (PCB) connector that mates with the edge of another PCB, commonly used in high-speed memory modules for reliable electrical connections.

Frequently Asked Questions

What is the role of the TFT Array in a Flat Panel Detector?