Stacked Lens Camera Module Direct Bonding Accuracy

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Solution Overview

Problem

The wafer-level lens process faces challenges in achieving shape and position accuracy for stacked lenses, particularly in manufacturing stacked lens structures, which limits their application in camera modules, especially for mass production beyond three layers.

Innovation Solution

A camera module design incorporating a first pixel array for R, G, or B wavelengths and a second pixel array for visible light, with dedicated optical units to converge light onto each array, utilizing direct bonding between substrates with oxide or nitride-based surface layers to enhance accuracy and prevent deformation from curing shrinkage and thermal expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If wafer-level lens process is used to manufacture stacked lenses, then mass production capability is improved, but shape accuracy and position accuracy deteriorate

Engineering Contradiction:

Improvemass production capabilityVSAvoidshape accuracy and position accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent divides the stacked lens structure into separate substrates (first substrate with first lens, second substrate with second lens) that are bonded together. Each substrate can be manufactured independently with high precision using wafer-level processes, then assembled through direct bonding to achieve both mass production capability and high accuracy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary bonding process (direct bonding with oxide or nitride-based surface layers) between the separately manufactured substrates. This intermediary step enables precise alignment and bonding of multiple substrates, maintaining high shape and position accuracy while enabling mass production of stacked lens structures.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If three or more wafer substrates are stacked to manufacture stacked lens structure, then functionality is improved, but manufacturing difficulty increases significantly

Engineering Contradiction:

Improvestacked lens structure functionalityVSAvoidmanufacturing difficulty

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent segments the stacked lens into multiple independent substrates that can be manufactured separately using standardized wafer-level processes. This segmentation makes it feasible to stack three or more layers by treating each as an independent unit that can be precisely bonded to others.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs direct bonding technology with oxide or nitride-based surface layers as an intermediary bonding mechanism. This enables reliable bonding of three or more substrates together, overcoming the manufacturing difficulty that arises when attempting to stack multiple wafer substrates.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If lens material is used as adhesive to stack wafer substrates, then process simplicity is improved, but shape accuracy and position accuracy deteriorate

Engineering Contradiction:

Improveprocess simplicityVSAvoidshape accuracy and position accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent replaces the lens material adhesive with a dedicated bonding layer (oxide or nitride-based surface layer) that serves as an intermediary for substrate bonding. This intermediary layer enables precise alignment and bonding without the deformation and accuracy issues caused by using lens material as adhesive.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent substitutes the chemical bonding mechanism (lens material as adhesive) with a physical bonding mechanism (direct bonding through oxide or nitride layers). This substitution eliminates the harmful effects of curing shrinkage and thermal expansion that occur with material-based adhesives, maintaining high manufacturing precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 solution enables the creation of camera modules with improved accuracy and reliability for various applications, allowing for the use of stacked lenses in camera modules beyond three layers, addressing the limitations of existing wafer-level lens processes.

Implementation Method 1

a first optical unit that converges incident light onto the first pixel array

Methodology Applied

Scientific EffectLight convergence: Lens

Implementation Method 2

a second optical unit that converges the incident light onto the second pixel array

Methodology Applied

Scientific EffectLight convergence: Lens

Data Source

PatentUS10375282B2Camera module with stacked lens structure and electronic apparatus

Publication Date: 2019.08.06 SONY SEMICON SOLUTIONS CORP

AI summary

The present technique relates to a camera module and an electronic apparatus that allow a camera module to be used for various purposes. The camera module includes a first pixel array in which pixels that receive light having an R, G, or B wavelength are two-dimensionally arranged in a matrix form and a second pixel array in which pixels that receive light having a wavelength region of visible light are two-dimensionally arranged in a matrix form and a first optical unit that converges incident light onto the first pixel array and a second optical unit that converges the incident light onto the second pixel array. The present technique can be for example applied to a camera module and the like.