Wire Grid Polarizer Electrical Connection for Imaging Device Manufacturing

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Solution Overview

Problem

In manufacturing wire grid polarizers for imaging devices, the light-reflecting and light-absorbing layers are in a floating state, leading to potential charging and discharge issues during film formation or etching, which can damage the polarizer and photoelectric conversion unit, and result in electrostatic dust adhesion before the device is sealed.

Innovation Solution

A method where the light-reflecting layer is formed and electrically connected to the substrate or photoelectric conversion unit, followed by the formation of a light-absorbing layer in contact with the light-reflecting layer, and both are patterned to create a wire grid polarizer with stacked structures, ensuring electrical connection and preventing charging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the light-reflecting layer-forming layer and light-absorbing layer-forming layer are formed in a floating state (not electrically connected), then the wire grid polarizer can be formed with isolated stacked structures, but the layers may be charged during film formation or etching causing discharge that damages the polarizer and photoelectric conversion unit

Engineering Contradiction:

Improveease of forming isolated stacked structuresVSAvoidrisk of discharge damage

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

A conductive layer is introduced as an intermediary between the light-reflecting layer-forming layer and the light-absorbing layer-forming layer. This conductive layer acts as a mediator that provides electrical connection to prevent charging, while allowing the stacked structures to maintain their functional isolation for polarizer operation. The conductive layer is formed to extend beyond the stacked structures to provide adequate electrical connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a conductive layer is formed on all surfaces of the wire grid polarizer to prevent charging, then electrostatic dust adhesion is prevented, but it becomes difficult to prevent the light-reflecting layer-forming layer or light-absorbing layer-forming layer from being charged during film formation or etching processes

Engineering Contradiction:

Improveelectrostatic dust adhesionVSAvoidcharging during manufacturing

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The conductive layer is formed preliminarily, before the wire grid polarizer is fully assembled and sealed. This preliminary formation of the conductive layer ensures that electrical connection is established during the manufacturing process, preventing charging of the layer-forming layers during subsequent film formation and etching steps. The conductive layer is prepared in advance to cover necessary areas for electrical connection.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the light-reflecting layer and light-absorbing layer are electrically connected, then charging during manufacturing is prevented, but the structural complexity increases compared to completely isolated floating layers

Engineering Contradiction:

Improveprevention of chargingVSAvoidelectrical connection structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The conductive layer serves multiple functions simultaneously: it provides electrical connection to prevent charging during manufacturing, extends beyond the stacked structures to ensure adequate coverage, and maintains compatibility with the isolated stacked structure design for polarizer functionality. This multi-functional approach reduces the need for separate components and simplifies the overall structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 approach prevents damage to the wire grid polarizer and photoelectric conversion unit during manufacturing by maintaining electrical connection, reducing discharge risks, and preventing electrostatic dust adhesion, thus enhancing the reliability and cleanliness of the imaging device.

Implementation Method 1

a light-reflecting layer made of a first electrical conducting material

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 2

a light-absorbing layer made of a second electrical conducting material

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS11652122B2Imaging element, method of manufacturing imaging element, imaging device, and method of manufacturing imaging device

Publication Date: 2023.05.16 SONY SEMICON SOLUTIONS CORP

AI summary

There is provided a method of manufacturing an imaging device including a plurality of imaging elements in an imaging area, where each imaging element includes a photoelectric conversion unit in a substrate and a wire grid polarizer arranged at a light-incident side of the photoelectric conversion unit. The method generally includes forming the wire grid polarizer that includes a plurality of stacked strip-shaped portions, where each of the plurality of stacked strip-shaped portions includes a portion of a light-reflecting layer and a portion of a light-absorbing layer. The light-reflecting layer may include a first electrical conducting material that is electrically connected to at least one of the substrate or the photoelectric conversion unit. The light-absorbing layer may include a second electrical conducting material, where at least a portion of the light-absorbing layer is in contact with the light-reflecting layer.