Ultra-Thin Time-of-Flight Sensor With Coplanar Filter Package

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Solution Overview

Problem

Conventional time-of-flight sensors are too thick, limiting their application in consumer electronics and industrial products due to increased thickness.

Innovation Solution

A time-of-flight sensor design comprising a substrate, single photon avalanche detection chip, vertical cavity surface-emitting laser, narrowband pass filter glasses, and a resin shell, with specific adhesive frames and manufacturing processes to achieve a slim form factor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the sensor thickness is reduced to enable integration into handheld devices, then the adaptability and ease of installation improve, but the structural complexity of achieving such thinness increases

Engineering Contradiction:

Improveintegration capability into handheld devicesVSAvoidstructural complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The sensor is divided into multiple functional layers including substrate, semiconductor layer, first electrode, second electrode, and protective layer. Each layer performs a specific function, allowing the overall thickness to be reduced while maintaining functionality through optimized layering rather than bulk structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from a conventional thick vertical stack to an ultra-thin planar structure by optimizing the thickness of each layer in the vertical dimension. The coplanar arrangement of filter glass upper surfaces creates a flat profile suitable for handheld device integration.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If the sensor thickness is reduced, then the compactness improves, but the manufacturing precision required to maintain functionality increases

Engineering Contradiction:

Improvesensor thicknessVSAvoidlayer thickness control

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent specifies precise thickness parameters for each layer: semiconductor layer (1-10 μm), first electrode (0.1-5 μm), second electrode (0.1-5 μm), and protective layer (0.1-5 μm). These parameter specifications enable manufacturing precision control while achieving ultra-thin overall dimensions.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The use of thin film structures for electrodes and protective layers allows precise thickness control during manufacturing. The thin film technology enables accurate deposition and uniform thickness across the sensor area, maintaining functionality despite reduced overall thickness.

Inventive Principle:

Principle #30Flexible shells and thin films

3Ease of manufacture

If conventional thick sensor design is used, then the manufacturing process is simpler, but the sensor cannot be integrated into space-constrained devices

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidsensor thickness

Core Design Contradiction:

Ease of manufactureVSLength of moving object

Solution Approach 1:

The sensor structure is segmented into standard semiconductor layers that can be manufactured using conventional CMOS or semiconductor fabrication processes. This segmentation allows existing manufacturing equipment and techniques to be used, maintaining ease of manufacture while achieving thin dimensions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs composite material structures combining semiconductor materials, conductive materials for electrodes, and protective materials. These composite structures are designed to be compatible with standard manufacturing processes while achieving the required thin profile for device integration.

Inventive Principle:

Principle #40Composite materials

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 sensor achieves a thickness of less than 400 μm, enabling easy installation in handheld devices like smartphones and improving ranging functions.

Implementation Method 1

single photon avalanche detection chip

Methodology Applied

Scientific EffectAvalanche breakdown: Avalanche Breakdown

Implementation Method 2

vertical cavity surface-emitting laser

Methodology Applied

Scientific EffectLaser emission: Laser

Implementation Method 3

first narrowband pass filter glass, second narrowband pass filter glass

Methodology Applied

Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentUS12603472B2Time-of-flight sensor and manufacturing method thereof

Publication Date: 2026.04.14 RECO TECH CHENGDU CO LTD

AI summary

A time-of-flight sensor includes a substrate, a single photon avalanche detection chip, a vertical cavity surface-emitting laser, a first narrowband pass filter glass, and a second narrowband pass filter glass and a resin shell. The single photon avalanche detection chip is attached on the substrate, and the vertical cavity surface-emitting laser is also attached on the substrate. The first narrowband pass filter glass is arranged above the single photon avalanche detection chip, and the second narrowband pass filter glass is arranged above the vertical cavity surface-emitting laser. The resin shell covers the first narrowband pass filter glass and the second narrowband pass filter glass, and an upper surface of the first narrowband pass filter glass and an upper surface of the second narrowband pass filter glass are coplanar with an upper surface of the resin shell.