Capped Semiconductor Sensor Wafer for Dust-Blocked Die Singulation

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Solution Overview

Problem

Semiconductor-based sensor devices with micro- and/or nanostructures are prone to contamination and malfunction due to dust and particles during the dividing process and operation, especially in dusty environments.

Innovation Solution

A method for fabricating semiconductor-based sensor devices involves using a capping wafer with recesses and holes, where a liquid is injected to form gas permeable segments in the passages, protecting the sensor parts from dust and particles during the dividing process and operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a rotating blade is used for dividing the device wafer into individual sensor devices, then the dividing process can be performed efficiently, but particles and heat are generated that may contaminate and damage the micro- and nanostructures

Engineering Contradiction:

Improvedividing process efficiencyVSAvoidparticle contamination and heat damage to microstructures

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

A capping wafer is attached to the device wafer before the dividing process to pre-establish protection for the micro- and nanostructures. This preliminary protective measure ensures that when the rotating blade divides the wafer, particles and heat cannot reach the sensitive structures, thus resolving the contradiction between efficient dividing and contamination prevention

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The capping wafer acts as an intermediary barrier between the rotating blade (dividing tool) and the sensitive micro- and nanostructures. This intermediate layer absorbs the harmful effects of the dividing process while allowing the process to proceed efficiently, thus protecting the structures without compromising productivity

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the waveguide is configured to be partially freehanging to minimize effects from compromising factors, then gas interaction is improved, but the sensor becomes more fragile and sensitive to dust and particles

Engineering Contradiction:

Improvegas sensing accuracyVSAvoiddust and particle contamination

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The capping wafer is attached before the dividing process to pre-establish a protective environment for the freehanging waveguide. This allows the waveguide to maintain its freehanging configuration for optimal gas interaction while being protected from dust and particles generated during dividing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The capping wafer serves as an intermediary protective layer that allows gas to reach the freehanging waveguide through openings while blocking dust and particles from the dividing process. This resolves the contradiction by enabling both freehanging configuration for gas sensing and protection from contamination

Inventive Principle:

Principle #24Intermediary (Mediator)

3Temperature

If water is sprayed onto the blade and wafer during die sawing for cooling, then heat is removed, but water and particles may come into contact with the waveguide

Engineering Contradiction:

Improvecooling during dividingVSAvoidwater and particle contact with waveguide

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The capping wafer acts as an intermediary barrier that allows cooling water to be sprayed during die sawing while preventing both water and particles from reaching the waveguide. The capping wafer's structure enables thermal management without compromising the protected structures

Inventive Principle:

Principle #24Intermediary (Mediator)

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 gas permeable segments effectively prevent dust and particles from reaching the sensor parts during the dividing process and operation, enhancing the reliability and longevity of the sensor devices.

Implementation Method 1

injecting a liquid into the passages and the holes, forming, from the liquid, gas permeable segments in the passages

Methodology Applied

Scientific EffectPhase change: Phase Change

Implementation Method 2

forming, from the liquid, gas permeable segments in the passages

Methodology Applied

Scientific EffectGas permeability: Permeation

Data Source

PatentUS20250044223A1Capped semiconductor based sensor and method for its fabrication

Publication Date: 2025.02.06 SENSEAIR

AI summary

A method for fabricating semiconductor-based sensor devices and such a sensor device are described. The sensor devices comprise sensors comprising micro- and/or nanostructures which are in communication with the environment surrounding the sensor devices. The method comprises the steps of providing a semiconductor-based device wafer, fabricating a plurality of sensors on the semiconductor-based device wafer (1), providing (102) a capping wafer, attaching a first side of the capping wafer on the device wafer with each sensor arranged below a recess. The capping wafer comprises, between the recesses, a plurality of holes extending from the second side, wherein the holes are in fluid communication with the cavities by passages arranged between contact areas when the capping wafer has been attached to the device wafer. The method comprises the steps of injecting a liquid into the passages and the holes, forming, from the liquid, a gas permeable segment in the passages, and dividing the device wafer and the attached capping wafer into individual devices along lines through the holes.