Coplanar Conductive Interconnect for Solar Cell Electrical Coupling

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Solution Overview

Problem

The existing methods for interconnecting photovoltaic cells result in overlapping structures that increase the thickness of solar panels and can lead to short circuits due to uncontrolled conductive material overflow, necessitating additional insulation and diode connections to prevent energy dissipation.

Innovation Solution

The solution involves a photovoltaic cell design with front and back conductive layers, a support substrate, and vias filled with conductive material, where the conductive material forms electrical contacts with the front electrodes while being insulated from the back electrodes and the p-side of the photovoltaic layer, allowing for efficient electrical coupling without overlapping and reduced thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If solar cells are interconnected by overlapping with vias filled with conductive material, then electrical connection between cells is achieved, but the panel thickness increases and conductive material may overflow causing short circuits

Engineering Contradiction:
Improveelectrical connectionVSAvoidpanel thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent transitions from vertical overlapping connection to a planar TEP connection architecture. The conductive interconnect is disposed substantially coplanar with the front surface of the photovoltaic layer, eliminating the need for vertical via penetration through multiple cell layers. This dimensional change from 3D overlapping to 2D planar arrangement reduces panel thickness while maintaining electrical connectivity.

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

Solution Approach 2:

The patent introduces a conductive interconnect as an intermediary element that facilitates electrical connection between series of photovoltaic cells. Instead of direct cell-to-cell via connection, the conductive interconnect acts as a mediator that receives electrical connection from front electrodes of one series of cells and provides connection to back electrodes of another series, eliminating the need for thick overlapping structures.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If conductive material is overfilled in back vias to prevent void formation, then electrical contact reliability is improved, but lateral overflow occurs causing short circuits between electrodes

Engineering Contradiction:
Improveelectrical contactVSAvoidconductive material overflow
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the electrical connection function from the overlapping cell structure and relocates it to a separate conductive interconnect element. The TEP connection architecture removes the need for via filling with conductive material that causes overflow problems. Electrical connectivity is achieved through the conductive interconnect disposed coplanar with the cell surface, eliminating the harmful lateral overflow effect entirely.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The conductive interconnect serves as an intermediary that eliminates the need for via filling operations. Instead of injecting conductive material into vias that may overflow, the conductive interconnect provides a controlled, planar connection interface that achieves reliable electrical contact without the harmful overflow associated with via filling.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If insulating material is deposited around solar cell perimeters and insulating adhesive is applied, then short circuit prevention is achieved, but device complexity and manufacturing steps increase

Engineering Contradiction:
Improveshort circuit preventionVSAvoidinsulation structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the insulation function from separate adhesive layers and integrates it into the TEP connection architecture itself. The coplanar conductive interconnect design inherently prevents short circuits by eliminating vertical conductive paths through overlapping cells. This integration removes the need for separate insulating adhesive layers and perimeter insulation, reducing device complexity while maintaining short circuit prevention.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If overlapping structure with vias and conductive material is used, then electrical interconnection is achieved, but the overall thickness of the solar panel increases

Engineering Contradiction:
Improveelectrical interconnectionVSAvoidpanel thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent fundamentally changes the connection dimension from vertical overlapping to horizontal coplanar arrangement. The conductive interconnect is disposed substantially coplanar with the front surface of the photovoltaic layer, creating a 2D connection architecture instead of 3D vertical stacking. This dimensional transformation maintains electrical interconnection functionality while dramatically reducing panel thickness by eliminating multiple overlapping cell layers.

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

This design enables efficient electrical interconnection of photovoltaic cells without the need for overlapping structures, reducing panel thickness and preventing short circuits, while allowing for convenient connection of diodes to protect against energy dissipation.

Implementation Method 1

a photovoltaic layer configured to convert light energy to electrical energy

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Implementation Method 2

a front via extends through the support substrate layer, the back conductive layer and the photovoltaic layer, dispensed with a conductive material and a insulation material. The insulation material insulates the conductive material from an electrical contact with the back conductive layer and a P side of the photovoltaic layer, the conductive material forms an electrical contact with the front conductive layer.

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3403283B1Method for interconnecting solar cells
Publication Date: 2019.10.30 ALTA DEVICES INC
  • EP3403283B1 patent drawingFigure 1A
  • EP3403283B1 patent drawingFigure 1B~1C
  • EP3403283B1 patent drawingFigure 2A

AI summary

A photovoltaic module comprises a back substrate having a plurality of conductive interconnects on top thereof. A conductive interconnect includes a first contact region and a second contact region. The photovoltaic module further comprises a plurality of photovoltaic cells comprising front electrodes disposed on a front surface of a photovoltaic layer on top of back electrodes on top of a support substrate. A plurality of back vias extending through the support substrate of a first cell form an electrical contact between the back electrodes and the second contact region, and a plurality of front vias extending through the support substrate, the back electrodes and the photovoltaic layer of a second cell form an electrical contact between the front electrodes and the first contact region, and is insulated from an electrical contact with the back electrodes and a P side of the photovoltaic layer.