Solar Cell Chip Laser Cutting Geometry for Wafer Utilization

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Solution Overview

Problem

Existing methods for manufacturing solar cell chips result in inefficient use of cost-intensive wafers due to the rectangular geometry and sawing process, leading to significant area loss and high production costs, especially when using secondary concentrators with high reflectance and low absorption materials.

Innovation Solution

The method involves cutting solar cell chips from wafers using a laser in non-rectangular geometries such as hexagonal, sinusoidal, or circular shapes to maximize active area utilization, allowing for continuous cutting and reducing waste, with active areas optimized for solar energy conversion and non-active areas used for electric bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If rectangular solar cell chips are cut from wafers using sawing, then the manufacturing process is simple and straightforward, but the wafer area utilization is low with significant cutting waste

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidwafer area utilization

Core Design Contradiction:

Ease of manufactureVSLoss of substance

Solution Approach 1:

The patent applies curved cutting paths (sinusoidal, circular, or other curved geometries) instead of straight linear cuts to separate solar cell chips from the wafer. This curvature allows the cutting laser to follow optimal paths that maximize the number of chips obtained from each wafer, reducing waste material while maintaining continuous cutting operation capability.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent changes the geometric parameters of the cutting process by introducing curved paths with specific mathematical descriptions (sinusoidal functions, circular arcs). These parameter changes in cutting trajectory enable more efficient wafer utilization, increasing chip yield from approximately 60% with rectangular cuts to over 70% with optimized curved cutting paths.

Inventive Principle:

Principle #35Parameter changes

2Loss of substance

If the number of solar cell chips per wafer is increased through non-rectangular geometries, then wafer area utilization improves, but the cutting process complexity increases

Engineering Contradiction:

Improvewafer area utilizationVSAvoidcutting process complexity

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical sawing with laser cutting technology. This substitution enables continuous cutting along complex curved paths without the mechanical constraints of saw blades, allowing sinusoidal and circular cutting patterns to be implemented easily through laser beam control, thus managing complexity through software rather than mechanical complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements continuous cutting paths without interruptions, repositioning, or tool changes. The laser beam continuously traces the curved cutting paths (sinusoidal or circular) from one edge of the wafer to the other, maintaining uninterrupted cutting action. This continuity simplifies the overall process by eliminating multiple discrete cutting operations and positioning steps.

Inventive Principle:

Principle #20Continuity of useful action

3Productivity

If cell sizes are reduced below 2 mm to increase concentration, then the concentration factor increases, but the usable area is drastically reduced due to cutting waste

Engineering Contradiction:

Improveconcentration factorVSAvoidusable area

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

For small cell sizes below 2 mm, the patent employs curved cutting paths that are particularly effective at minimizing waste. The sinusoidal and circular patterns allow closely spaced cuts with optimized spacing, ensuring that even tiny cells can be extracted from the wafer with minimal material loss, maintaining high concentration factors while preserving usable area.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent adjusts the parameters of the curved cutting paths (amplitude, frequency, radius, spacing) to optimize for small cell dimensions. By changing these geometric parameters, the cutting pattern adapts to produce numerous small cells per wafer while minimizing the kerf loss and waste, enabling high concentration applications to maintain economic viability.

Inventive Principle:

Principle #35Parameter changes

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 increases the number of solar cell chips per wafer by approximately 16% and enhances wafer area utilization, reducing production costs and improving the efficiency of solar cell module manufacturing.

Implementation Method 1

separating them into a plurality of solar cell chips by means of a continuous cutting operation of the laser

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentUS9059365B2Solar cell chips with new geometry and method for manufacturing the same

Publication Date: 2015.06.16 SAINT AUGUSTIN CANADA ELECTRIC

AI summary

A method for manufacturing solar cell chips having an active surface area configured to directly convert solar energy into electrical energy. The method including cutting the solar cell chips out of a wafer using a laser such that the solar cell chips include a non-rectangular geometry. The non-rectangular geometry facilitate continuous cutting by the laser and maximizing a number of solar cell chips cut from the wafer.