Thinned Photosensor Substrate for X-ray Detector Resolution
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Solution Overview
Problem
Conventional spectral CT scanners have limited resolution in the x-direction due to the finite thickness of photodiode substrates in detector arrays, which are also fragile and unsuitable for constructing detector modules.
Innovation Solution
A method involving a photosensor substrate with an initial thickness of at least 100 microns, optically coupled with a scintillator array, and then thinned to less than 100 microns, allowing for a higher resolution detector array with more detector modules per given length, enhancing x-direction resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the photodiode substrate thickness is increased to improve structural integrity, then the detector array can be constructed more reliably, but the resolution in the x-direction deteriorates
Solution Approach 1:
The patent applies preliminary action by obtaining the photosensor substrate with sufficient thickness (≥100 microns) before thinning, allowing the substrate to be constructed with adequate structural integrity. The substrate is then thinned to <100 microns after construction, achieving both reliable construction and high resolution. This sequence resolves the contradiction by performing the thick-construction action before the thinning action.
Solution Approach 2:
The patent changes the thickness parameter of the photosensor substrate through a two-stage process: first maintaining thickness ≥100 microns for structural integrity during construction, then reducing thickness to <100 microns for high resolution. This parameter change sequence resolves the contradiction between reliability and manufacturing precision.
2Manufacturing precision
If the photodiode substrate is thinned to improve x-direction resolution, then more detector modules can be arranged per given length, but the substrate becomes fragile and difficult to construct
Solution Approach 1:
The patent performs the construction action while the substrate is still thick (≥100 microns), making it easy to handle and assemble. After construction is complete, the substrate is thinned to <100 microns to achieve high resolution. This preliminary construction before thinning resolves the contradiction between ease of manufacture and manufacturing precision.
Solution Approach 2:
The scintillator array is optically coupled to the photosensor substrate before thinning, ensuring that all components are in place while the substrate is still structurally sound. This preliminary assembly resolves the manufacturing difficulty that would arise from handling thin substrates during construction.
3Strength
If a thick photosensor substrate is used, then the detector modules are structurally sound, but the detector array resolution in the x-direction is limited
Solution Approach 1:
The patent changes the thickness parameter from ≥100 microns (for strength) to <100 microns (for resolution) through a controlled thinning process. The substrate is first constructed with sufficient thickness for strength, then thinned to achieve high resolution, resolving the contradiction between strength and manufacturing precision.
Solution Approach 2:
The detector modules are constructed with thick substrates for structural soundness, then the substrate is thinned after construction is complete. This preliminary construction with thick substrates resolves the contradiction by ensuring structural integrity during assembly before reducing thickness for resolution.
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 thinned photosensor substrate with a scintillator array increases detector resolution by up to 30-60% in the x-direction, enabling higher definition imaging without compromising the structural integrity of the detector modules.
Implementation Method 1
Each module 102 includes first and second scintillator rows 108 and 110 optically coupled to corresponding first and second detection regions 112 and 114 of a photodiode substrate 116
Implementation Method 2
The detector array detects the radiation and generates electrical signals indicative of the examination region and the subject or object disposed therein
Data Source
AI summary
A method includes obtaining a photosensor substrate (236) having two opposing major surfaces. One of the two opposing major surfaces includes at least one photosensor row (230) of at least one photosensor element (232, 234), and the obtained photosensor substrate has a thickness equal to or greater than one hundred microns. The method further includes optically coupling a scintillator array (310) to the photosensor substrate. The scintillator array includes at least one complementary scintillator row (224) of at least one complementary scintillator element (226, 228), and the at least one complementary scintillator row is optically coupled to the at least one photosensor row (230) and the at least one complementary scintillator element is optically coupled to the at least one photosensor element. The method further includes thinning the photosensor substrate optically coupled to the scintillator producing a thinned photosensor substrate that is optically coupled to the scintillator and that has a thickness on the order of less than one hundred microns.