Solar Interconnector Assembly Heating Drum

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Solution Overview

Problem

The fabrication of solar cell interconnectors faces challenges in reliably bonding electrical conductors to insulating sheets without causing damage to the fabrication apparatus and ensuring high-quality interconnector assemblies, as heating the sheets to make them sticky can lead to adherence issues and material distortions.

Innovation Solution

A method involving a rotatable heating drum with a structured surface that selectively heats only the contact zones of the sheet above the melting temperature, while keeping the rest below, using a combination of heat transfer and inductive heating to maintain the non-sticky state of the sheet's intermediate portions, preventing adherence to apparatus components and ensuring reliable bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sheet is heated to make it sticky for bonding conductors, then the bonding reliability is improved, but the sheet adheres to fabrication apparatus components causing damage and contamination

Engineering Contradiction:
Improvebonding reliabilityVSAvoidsheet adherence to apparatus
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The heating drum is designed with alternating heated and non-heated zones along its circumference. The heated zones (first portions) locally heat the sheet material to melting temperature only in the regions where conductors are being bonded, while the non-heated zones (second portions) keep other regions below melting temperature. This local quality approach allows the sheet to be sticky only where needed, preventing adherence to apparatus components in non-bonding areas.

Inventive Principle:
Principle #3Local quality

2Reliability

If the sheet is heated uniformly to make it sticky, then the bonding reliability is improved, but the deformability of the sheet causes distortions of the interconnector assembly

Engineering Contradiction:
Improvebonding reliabilityVSAvoidassembly distortion
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

By implementing localized heating zones on the heating drum, only specific regions of the sheet are heated to melting temperature where conductor bonding is required. The rest of the sheet remains below melting temperature and maintains its structural integrity. This prevents unwanted deformations and distortions of the interconnector assembly while still achieving reliable bonding at the contact zones.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The heating drum surface is segmented into multiple heated and non-heated zones arranged alternately along its circumference. This segmentation allows different regions of the sheet to be at different temperatures simultaneously, with heated zones providing bonding capability and non-heated zones maintaining dimensional stability, thus preventing assembly distortion.

Inventive Principle:
Principle #1Segmentation

3Reliability

If the sheet is heated to make it sticky, then the bonding reliability is improved, but the cleaning and service time increases due to apparatus contamination

Engineering Contradiction:
Improvebonding reliabilityVSAvoidcleaning and service time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The heating drum creates localized sticky zones only where conductors are being bonded, while other areas of the sheet remain non-sticky and do not adhere to apparatus components. This dramatically reduces contamination of the fabrication apparatus, minimizing cleaning and service time while maintaining reliable bonding at the contact zones.

Inventive Principle:
Principle #3Local quality

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 sheet adherence to fabrication apparatus components, maintains the quality of interconnector assemblies by controlling temperature distribution, and reduces cleaning and service time, resulting in cost-effective and high-quality interconnectors.

Implementation Method 1

increasing the temperature in the at least one contact zone of the sheet above the first temperature, wherein the first temperature is above the temperature at which the material forming that contact zone becomes sticky

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

the first temperature is above the temperature at which the material forming that contact zone becomes sticky

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

the side of the sheet that faces away from the conductor array is kept at a second temperature, wherein the second temperature is below the temperature at which the material forming the side of the sheet that faces away from the conductor array becomes sticky

Methodology Applied
Scientific EffectTemperature control: Heating

Implementation Method 4

using a combination of heat transfer and inductive heating to maintain the non-sticky state of the sheet's intermediate portions

Methodology Applied
Scientific EffectInductive heating: Induction Heating

Data Source

PatentEP3046151B1Method and apparatus of fabricating an interconnector assembly
Publication Date: 2019.04.03 SOMONT
  • EP3046151B1 patent drawingFigure 1~2
  • EP3046151B1 patent drawingFigure 3~4
  • EP3046151B1 patent drawingFigure 5~8

AI summary

The invention to a method of making an interconnector assembly for electrically interconnecting solar cells, wherein the method comprises: feeding a plurality of (preferably elongated) electrical conductors that form an conductor array defining interspaces that are free from conductors; and applying at least one sheet, preferably made of electrically insulating material, to a side of the conductor array, wherein the sheet has at least one contact zone coming into contact with the conductors and intermediate portions overlapping with the interspaces of the conductor array. The invention also refers to an apparatus for fabricating an interconnector assembly for electrically interconnecting solar cells and to a rotatable heating drum.