Laser Foil Metallization for Solar Cells With Integrated Contact Patterning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solar cell manufacturing processes are inefficient and costly, with conventional metallization techniques requiring multiple steps and high capital investment, limiting the ability to achieve high efficiency and reduce costs per unit produced.
Innovation Solution
A laser-assisted metallization process (LAMP) that deposits and patterns metal on semiconductor substrates in a single operation, using a laser to form conductive contact structures while simultaneously patterning and ablation, eliminating the need for separate vacuum chambers or chemical baths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional separate deposition and patterning processes are used, then manufacturing precision is achieved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines separate deposition and patterning operations into a single laser-based metallization process. The laser beam simultaneously deposits metal and patterns it by controlling the beam's position, duration, and intensity, eliminating the need for sequential processing steps and reducing overall process complexity.
Solution Approach 2:
The laser beam serves multiple functions within a single operation: it heats the metal source for deposition, patterns the deposited metal through selective heating or ablation, and can even prepare the substrate surface. This multi-functionality reduces the number of separate tools and processes needed.
2Reliability
If conventional metallization processes are used, then electrical conductivity is achieved, but manufacturing cost increases
Solution Approach 1:
The patent enables the use of less expensive metal materials such as aluminum or copper foils instead of traditional expensive materials like silver paste. The laser process effectively deposits and patterns these cheaper materials to achieve the required electrical conductivity, significantly reducing material costs.
Solution Approach 2:
The laser parameters (power, pulse duration, scanning speed) are optimized to ensure proper metal deposition and patterning while maintaining electrical conductivity. By controlling these parameters, the process achieves reliable conductive pathways using cost-effective materials.
3Productivity
If feature size is reduced for tighter pitch, then productivity increases, but manufacturing precision requirements become more stringent
Solution Approach 1:
The patent replaces conventional mechanical lithography and patterning tools with a laser-based system. The laser beam's precise optical control allows for accurate feature definition and tight pitch spacing without the limitations of mechanical contact methods, enabling smaller features with high precision.
Solution Approach 2:
The laser beam uses pulsed or modulated delivery to deposit and pattern metal with precise temporal control. This periodic action allows for accurate feature sizing and spacing by controlling pulse duration, frequency, and scanning speed, achieving tight pitch requirements while maintaining manufacturing precision.
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
LAMP techniques enable precise, cost-effective metallization with smaller features, higher efficiency, and reduced manufacturing costs by integrating deposition and patterning in a single step, allowing for the use of less expensive metals like aluminum, and enabling higher yield and finer pitch.
Implementation Method 1
portions of the metal source are exposed to a laser beam to form a plurality of conductive contact structures
Implementation Method 2
The laser beam Welds, Bonds or locally melts or vaporizes the metal source
Implementation Method 3
The laser beam Welds, Bonds or locally melts or vaporizes the metal source
Data Source
AI summary
Local patterning and metallization of semiconductor structures using a laser beam, e.g., micro-electronic devices, semiconductor substrates and/or solar cells, are described. For example, a method of fabricating a solar cell includes providing a substrate having an intervening layer thereon. The method also includes locating a metal foil over the intervening layer. The method also includes exposing the metal foil to a laser beam, wherein exposing the metal foil to the laser beam forms openings in the intervening layer and forms a plurality of conductive contact structures electrically connected to portions of the substrate exposed by the openings.