Through-Hole Electrodes for Uniform Interconnection in APD Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor light detection elements with avalanche photodiodes connected in parallel, varying interconnection distances among pixels lead to differences in temporal resolution due to resistance and capacitance influences.
Innovation Solution
A light detection device configuration featuring through-hole electrodes penetrating the semiconductor substrate to connect quenching resistors, with bump electrodes linking these to corresponding electrodes on a mounting substrate, ensuring uniform interconnection distances and reducing the impact of resistances and capacitances, while a glass substrate enhances mechanical strength and facilitates scintillator installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If quenching resistors are connected in parallel to signal lines with varying interconnection distances, then device complexity is reduced, but temporal resolution uniformity deteriorates due to different resistance and capacitance influences
Solution Approach 1:
The patent transitions from planar surface connections to three-dimensional through-hole connections. By routing electrodes through the substrate thickness rather than along the surface, all pixels achieve equal interconnection distances equal to the substrate thickness, eliminating the variation problem while maintaining simple parallel connection architecture.
Solution Approach 2:
The substrate is divided into multiple through-holes distributed across its area, with each through-hole serving as an independent connection path. This segmentation allows each pixel to have its own dedicated through-hole electrode, ensuring uniform connection characteristics across all pixels while keeping the overall connection structure simple.
2Measurement precision
If through-hole electrodes are used to penetrate the semiconductor substrate, then interconnection distance uniformity is improved, but manufacturing complexity increases
Solution Approach 1:
The through-hole structure serves multiple functions simultaneously: it provides uniform interconnection distance, acts as a mechanical support, and enables electrical connection. The same through-hole geometry is used for all pixels, allowing standardized manufacturing processes to be applied across the entire substrate.
Solution Approach 2:
The patent changes the connection path from two-dimensional surface routing to one-dimensional vertical penetration through the substrate. This parameter change in connection geometry transforms the manufacturing challenge from complex lateral routing to simpler vertical drilling or etching processes, which are more easily standardized.
3Measurement precision
If multiple through-hole electrodes are formed in the semiconductor substrate, then temporal resolution is improved by equalizing interconnection distances, but substrate mechanical strength may be compromised
Solution Approach 1:
The through-hole electrodes are strategically positioned in specific regions of the substrate rather than uniformly distributed. This local placement optimizes the balance between achieving uniform interconnection distances for temporal resolution and maintaining adequate mechanical strength by minimizing the number and distribution of holes in critical structural areas.
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 significantly improves temporal resolution by equalizing interconnection distances among pixels and enhancing mechanical strength, reducing dead space, and maintaining high fill factor without compromising temporal resolution.
Implementation Method 1
a plurality of avalanche photodiodes operating in Geiger mode and formed in the semiconductor substrate
Implementation Method 2
when an avalanche photodiode forming a pixel detects a photon to induce Geiger discharge
Implementation Method 3
a plurality of through-hole electrodes electrically connected to the quenching resistors and formed so as to penetrate the semiconductor substrate
Implementation Method 4
the through-hole electrodes and the first electrodes are electrically connected through bump electrodes
Data Source
AI summary
A semiconductor light detection element includes a plurality of avalanche photodiodes operating in Geiger mode and formed in a semiconductor substrate, quenching resistors connected in series to the respective avalanche photodiodes and arranged on a first principal surface side of the semiconductor substrate, and a plurality of through-hole electrodes electrically connected to the quenching resistors and formed so as to penetrate the semiconductor substrate from the first principal surface side to a second principal surface side. A mounting substrate includes a plurality of electrodes arranged corresponding to the respective through-hole electrodes on a third principal surface side. The through-hole electrodes and the electrodes are electrically connected through bump electrodes, and a side surface of the semiconductor substrate and a side surface of a glass substrate are flush with each other.