Photon Counting Detector Ground Plane Layout for Lower Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current photon counting detectors face challenges with high Ohmic losses and increased noise due to the use of through silicon vias and dedicated ground lines, which affect efficiency and accuracy, and are costly to produce.
Innovation Solution
The detector design incorporates an electrical ground plane near the interface between the carrier and ROIC die, with peripheral circuitry arranged in an extension region outside the photon conversion assembly, allowing power supply lines to extend between the carrier and ROIC die, reducing Ohmic losses and eliminating the need for dedicated ground lines, and using bond wires for signal connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If through silicon vias and dedicated ground lines are used in photon counting detectors, then electrical connections are established, but Ohmic losses increase and noise increases
Solution Approach 1:
The patent extracts the ground connection function from the traditional through-silicon-via implementation and relocates it to an external ground plane on the carrier substrate. This separation eliminates the need for ground lines traversing the ROIC die thickness, removing the source of Ohmic losses while maintaining reliable electrical grounding for the peripheral circuitry.
Solution Approach 2:
The invention transitions the ground connection from a vertical through-silicon implementation to a horizontal plane-based implementation on the carrier substrate. By moving the ground plane to the carrier dimension rather than embedding it within the ROIC die thickness, the patent eliminates the need for vertical ground lines and reduces Ohmic losses in the signal path.
2Power
If through silicon vias are used for power supply connections, then power is delivered to peripheral circuitry, but manufacturing costs increase
Solution Approach 1:
The patent extracts the power delivery function from the through-silicon-via implementation and relocates it to external power supply lines on the carrier substrate. This separation eliminates the need for costly via formation and redistribution layer fabrication while maintaining reliable power delivery to the peripheral circuitry.
Solution Approach 2:
The invention replaces expensive through-silicon-via and redistribution layer structures with simpler, cheaper wire bond or printed circuit board trace connections on the carrier substrate. This substitution maintains power delivery functionality while significantly reducing manufacturing complexity and cost.
3Device complexity
If peripheral circuitry is arranged on the ROIC die, then integration is achieved, but input capacitance increases
Solution Approach 1:
The patent segments the detector system into two distinct functional modules: the ROIC die containing only the pixel array and photon detection circuitry, and the carrier substrate containing the peripheral circuitry. This segmentation physically separates the high-precision pixel inputs from the capacitive loads of peripheral circuits, minimizing input capacitance while maintaining system integration.
Solution Approach 2:
The carrier substrate acts as an intermediary between the ROIC die and the external world, housing the peripheral circuitry that would otherwise be integrated onto the ROIC die. This intermediary approach allows the ROIC die to maintain low input capacitance while still providing access to full detector functionality through the carrier interface.
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 configuration reduces power consumption, noise, and input capacitance, enabling improved performance at lower power levels while eliminating the need for costly through silicon vias and redistribution layers.
Implementation Method 1
photoconductor 2, and each pixel 101 comprises a photodiode 2 by which an incoming X-ray photon is directly converted into an electrical signal
Implementation Method 2
an electrical ground plane 202 is arranged in between ROIC die 133 and carrier 136... reducing Ohmic losses
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Aspects of the present disclosure relate to a photon counting detector and to a read-out integrated circuit to be used in such detector. Aspects of the present disclosure particularly relate to X-ray applications. According to an aspect of the present disclosure, the detector comprises an electrical ground plane arranged at or near an interface between the carrier and at least one ROIC die. Each ROIC die comprises an extension region that laterally extends beyond the photon conversion assembly, wherein peripheral circuitry for a given ROIC die is arranged in the extension region of that ROIC die. The detector comprises at least one electrical connection that connects the power supply line that is arranged on the carrier to the peripheral circuitry of the at least one ROIC die.