Stacked Solar Cell and Drive Circuit Integration for Compact Chips

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Solution Overview

Problem

Existing methods fail to produce an electronic device with a drive circuit, a solar cell structure, and a capacitor-function portion in one chip, leading to high production costs and large device area requirements.

Innovation Solution

A method involving bonding a first wafer with solar cell structures and a second wafer with drive circuits and capacitor-function laminated portions, followed by wiring and dicing to create a compact electronic device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a drive circuit and solar cell are integrated in one chip, then device area is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvedevice areaVSAvoidmanufacturing complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The device is divided into separate functional modules: a drive circuit module formed on a first substrate, and a solar cell module formed on a second substrate. These modules are manufactured independently and then bonded together, allowing each to be optimized separately while achieving integration in the final device.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A bonding process acts as an intermediary step between the separately manufactured drive circuit and solar cell modules. This bonding interface enables the integration of the two modules into one chip without requiring complex co-manufacturing processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If Si-based solar cell is used with drive circuit mounted, then manufacturing is simplified, but power receiving efficiency is low

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidpower receiving efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The material parameter of the solar cell is changed from conventional Si-based material to compound semiconductor material. This parameter change significantly improves power receiving efficiency while the separate module manufacturing approach keeps the overall manufacturing process manageable.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If compound semiconductor solar cell is epitaxially grown on Si substrate, then power receiving efficiency is improved, but production cost increases

Engineering Contradiction:
Improvepower receiving efficiencyVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The device is divided into separate functional modules: a drive circuit module formed on a first substrate, and a solar cell module formed on a second substrate. These modules are manufactured independently and then bonded together, allowing each to be optimized separately while achieving integration in the final device.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The material parameter of the solar cell is changed from conventional Si-based material to compound semiconductor material. This parameter change significantly improves power receiving efficiency while the separate module manufacturing approach keeps the overall manufacturing process manageable.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If solar cell area is increased, then power receiving efficiency is improved, but device area requirement increases

Engineering Contradiction:
Improvepower receiving efficiencyVSAvoiddevice area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The device transitions from a planar layout to a three-dimensional stacked configuration. The drive circuit module and solar cell module are arranged in different layers and bonded together, allowing the solar cell to have a larger effective area without increasing the device's footprint area.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 method results in a small-area electronic device with suppressed production costs by integrating a solar cell structure, diode circuit, and capacitor-function portion in one chip.

Implementation Method 1

A power receiving device for optical wireless power receiving is a solar cell

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Implementation Method 2

a first wafer having a plurality of independent solar cell structures comprising a compound semiconductor, the solar cell structures being formed on a starting substrate by epitaxial growth

Methodology Applied
Scientific EffectEpitaxial growth: Epitaxy

Data Source

PatentEP3985743B1Electronic device and method for manufacturing electronic device
Publication Date: 2025.12.10 SHIN ETSU HANDOTAI CO LTD
  • EP3985743B1 patent drawingFigure 1~2
  • EP3985743B1 patent drawingFigure 3~4
  • EP3985743B1 patent drawingFigure 5~6

AI summary

The present invention is a method for producing an electronic device having a drive circuit including a solar cell structure, the method including the steps of: providing a first wafer having solar cell structures on a starting substrate and a second wafer having drive circuits formed, so that either one of the first wafer or the second wafer has a plurality of independent diode circuits and capacitor-function laminated portions; obtaining a bonded wafer by bonding so that the solar cell structures, the diode circuits, the capacitor-function laminated portions, and the drive circuits are superimposed; wiring; and dicing the bonded wafer. This provides: a method for producing an electronic device including a drive circuit, a solar cell structure, and a capacitor-function portion in one chip and having a suppressed production cost; and such an electronic device.