Wafer Carrier for Image Sensor Protection and Light Transmittance

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Solution Overview

Problem

The manufacturing of image sensor chips faces challenges with dust pollution and increased costs due to the need for a glass sheet for protection, which also reduces light transmittance and makes wafer handling difficult, and the vulnerability of image sensing areas without protection during the manufacturing process.

Innovation Solution

A manufacturing method involving a carrier and a dam element with a temporary bonding layer to support and protect the wafer, allowing for the formation of isolation and conductive structures, dicing, and eventual removal of the carrier to align a light transmissive member with the image sensing area, enhancing detection capability while eliminating the need for a glass sheet.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a glass sheet is used to cover the wafer surface for protection, then the image sensing area is protected from dust pollution, but the light transmittance is reduced and manufacturing cost increases

Engineering Contradiction:

Improveprotection from dust pollutionVSAvoidlight transmittance

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The carrier is attached to the wafer before dicing and processing to provide protection during manufacturing. The carrier is removed after dicing but before final assembly, so the protection is provided only when needed during vulnerable manufacturing stages, not during final operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The protection function is segmented into different stages: the carrier provides protection during dicing and handling, then is removed, and finally a light transmissive member provides protection during operation. Each stage uses the appropriate protective element for its specific requirements.

Inventive Principle:

Principle #1Segmentation

2Reliability

If a glass sheet is used to cover the wafer surface, then the image sensing area is protected from dust pollution, but the manufacturing cost increases

Engineering Contradiction:

Improveprotection from dust pollutionVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The carrier is designed as a temporary, disposable protective element used only during the dicing and handling process. It is attached to the wafer, provides protection during vulnerable stages, then is discarded after serving its purpose, eliminating the need for expensive permanent protective glass sheets.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Illumination intensity

If the wafer thickness is reduced to improve light transmittance, then the image sensing capability is enhanced, but the wafer becomes difficult to handle and move

Engineering Contradiction:

Improvelight transmittanceVSAvoidease of handling

Core Design Contradiction:

Illumination intensityVSEase of operation

Solution Approach 1:

The carrier acts as an intermediary support structure that enables handling of thin wafers. By attaching the thin wafer to the rigid carrier, the carrier provides the mechanical strength needed for handling, while the thin wafer maintains its optical properties for light transmittance.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Illumination intensity

If the image sensing area is left unprotected during manufacturing, then the light transmittance is improved, but the image sensing area is vulnerable to dust pollution causing yield loss

Engineering Contradiction:

Improvelight transmittanceVSAvoidyield loss

Core Design Contradiction:

Illumination intensityVSProductivity

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

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 method supports the wafer during processing, prevents dust pollution, and improves image sensing capability while reducing costs by eliminating the need for a glass sheet, enhancing light transmittance and manufacturing efficiency.

Implementation Method 1

a first surface of the dam element is adhered to the carrier by a temporary bonding layer

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS9397138B2Manufacturing method of semiconductor structure

Publication Date: 2016.07.19 XINTEC INC

AI summary

A manufacturing method of a semiconductor structure includes the following steps. A carrier and a dam element are provided, and the dam element is adhered to the carrier by a temporary bonding layer. The dam element is bonded on the wafer. A first isolation layer, a redistribution layer, a second isolation layer, and a conductive structure are formed on the wafer in sequence. The carrier, the dam element and the wafer are diced to form a semiconductor element. The semiconductor element is disposed on a printed circuit board, such that the conductive structure is electrically connected to the printed circuit board. An adhesion force of the temporary bonding layer is eliminated to remove the carrier. A lens assembly is disposed on the printed circuit board, such that the semiconductor element without the carrier is located in the lens assembly.