Photodiode Array with Vertical Conductive Vias for Dead Space Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing photodiode arrays face challenges in minimizing dead space as the number of elements increases, with traditional methods either requiring complex and costly epitaxial layer transfer or increasing insensitive space between photodiodes due to the need for conductive strips.
Innovation Solution
A dielectric structure with face and back conductive areas on a semiconductor substrate, where photodiodes have separate face and back electrodes, and conductive holes connect these areas to minimize dead space and reduce fabrication complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional conductive strips are used to route contacts from center elements to perimeter, then electrical connection is achieved, but dead space between photodiodes increases
Solution Approach 1:
The patent routes conductive vias through the third dimension (vertical depth) of the substrate rather than along the surface. Multiple conductive vias are stacked vertically to create three-dimensional conductive pathways that connect center photodiodes to perimeter contacts without requiring horizontal conductive strips that would occupy valuable surface area between photodiode elements.
Solution Approach 2:
The patent implements nested conductive structures where multiple conductive vias are positioned concentrically or in overlapping patterns. Inner vias connect to outer vias through vertical conductive pathways, creating a nested arrangement that efficiently routes signals from center elements to perimeter contacts while minimizing the horizontal footprint and dead space between photodiodes.
2Reliability
If epitaxial layer transfer technology is used to manufacture photodiode arrays, then array element connectivity is improved, but fabrication complexity and cost increase
Solution Approach 1:
The patent divides the photodiode array into modular units with standardized conductive via patterns. Each photodiode element is connected through identical via structures that are replicated across the array, eliminating the need for complex epitaxial layer transfer processes. The segmentation approach allows independent fabrication of photodiode elements and conductive pathways.
Solution Approach 2:
The patent introduces conductive vias as intermediary structures that facilitate electrical connection between photodiode elements and perimeter contacts. These vias serve as mediators that replace the need for complex epitaxial layer transfer technology, providing a simpler fabrication pathway while maintaining reliable electrical connectivity across the array.
3Area of stationary object
If photodiode array size is increased to reduce dead space proportion, then sensitive area efficiency improves, but manufacturing difficulty increases
Solution Approach 1:
The patent addresses manufacturing scalability by transitioning to three-dimensional conductive via structures. This vertical routing approach allows photodiode arrays to be scaled to larger sizes without proportionally increasing the complexity of interconnect routing, as the via-based system can accommodate larger arrays through systematic replication of vertical pathways rather than complex horizontal trace routing.
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 allows for the creation of low-cost, compact photodiode arrays with minimal dead space, enabling efficient signal readout and reduced sensitive area reduction, suitable for large arrays.
Implementation Method 1
Each conductive area contains at least one individual conductive hole penetrating the dielectric structure from the face side to the opposite side of the dielectric structure. The conductive holes going to backside of the dielectric structure are connected with back conductive areas formed on back side of dielectric structure.
Implementation Method 2
Photodetector array and method of manufacture... position-sensitive detectors of weak light signals... photodiode arrays are widely used in research equipment and in consumer electronics as position-sensitive light detectors
Data Source
AI summary
The present invention is directed to photodiode arrays comprising a dielectric structure containing an array of face conductive areas (pads) and. Each photodiode is fully separated from each other. Every photodiode has a face electrode formed on sensitive side of the semiconductor substrate and an individual back electrode formed on the opposite side. The number of conductive areas on the dielectric structure is equal to number of photodiodes in the array. The photodiodes of the array are installed on the conductive areas so that their back electrodes have electrical contact with the corresponding conductive area. Each conductive area contains at least one individual conductive hole penetrating the dielectric package from the face side to the opposite side of the dielectric structure. The conductive holes going to backside of the dielectric structure are connected with the back conductive areas formed on back side of dielectric package.