Silver Pastes for Mono p-Type Cells

The Heraeus SOL9671B series front side silver paste was specially designed for ULDE (Ultra Lightly Doped Emitter) plus SE (Selective Emitter). SOL9671B series based on the glass chemistry upgraded from the last generation to offer superior metallization contact on ULDE plus SE, combined with the latest improvement in organic vehicle system for UFL(Ultra-Fine-Line) printing.

SOL9671B has a wide firing window toward lower temperature side, which makes the series well-performed on PERC solar cells, meanwhile, superior UFL printing ability gives more space to customer to reduce laydown and improve efficiency. It is worth mentioning that the SOL9671B platform is suitable for SP and DuP which allows our customers more choice of printing method.

KEY BENEFITS

• Ultra-Fine-Line screen printing
• Superior metallization for both Single print and Dual print
• Low laydown and high adhesion
• High VOC, extra protection on laser damaged Selective Emitter
• Low firing temperature and wide contact window can further reduce LeTID
• Perfect compatibility with multi Busbar printing

The Heraeus SOL9661B series front side silver paste was specially designed for ULDE (Ultra Lightly Doped Emitter) plus SE (Selective Emitter). SOL9661B series is based on the glass chemistry upgraded from the last generation to offer high adhesion and extra protection on laser damaged area, combined with the latest improvement in organic vehicle system for UFL(Ultra-Fine-Line) printing. As confirmed by customers, SOL9661B has efficiency gain > 0.05% in mass production.

SOL9661B has a wide firing window toward lower temperature side, which makes the series well-performed on PERC solar cells, meanwhile, superior UFL printing ability gives more space to customer to reduce laydown and improve efficiency. It is worth mentioning that the SOL9661B platform allows our R&D to offer solutions for different printing technology and emitter.

KEY BENEFITS

• Ultra-Fine-line screen printing
• Superior contact and Voc for SE PERC emitter
• Low laydown and high adhesion
• High Voc, extra protection on laser damaged Selective Emitter
• Low firing temperature and wide contact window can further reduce LeTID
• Perfect compatibility with multi Busbar printing
• Allow quick and efficient customization

Heraeus, the technology leader, closely following the industry trend, has developed the SOL9651B series based on the paste chemistry upgraded from last generation for ULDE (Ultra Lightly Doped Emitter) with Selective Emitter (SE), combined with the latest improvement in organic vehicle system for UFL (Ultra-Fine-Line) printing. As confirmed by customers, SOL9651B has efficiency gain > 0.10 % in mass production.

SOL9651B is an evolutionary product family designed for advanced PERC (Passivated Emitter Rear Contact) technology. Such paste chemistry provides a wide firing window toward lower temperature side, which makes this series well-performed on PERC. It is worth mentioning that the 9651B formulation also allows our local PML (Product Modification Labs) to do quick and efficient customization for versatile customer applications.

KEY BENEFITS

• High Voc, extra protection of laser damaged selective emitter area
• High FF, superior contact performance to provide more space of diffusion optimization
• Ultra-fine-line (UFL) screen printing for defect-free mass production
• Wide process window
• Great CTM (cell-to-module) performance
• Allows quick and efficient customization
• Double and Dual printing packages available
  • A+A’: SOL9652B1/SOL9652B2
  • A+B: SOL9651B/SOL9622B

Double printing has always been one of a synonym for high efficiency cell because of its advantages in finger quality and aspect ratio. Conceptually, Double printing gives them the ability to print very narrow printing finger lines on top of each other, this can be technically challenging for both cell manufacturer and metallization paste supplier.

Heraeus, the technology leader, closely collaborating with customers, has developed SOL9662B double-print front-side silver paste package. The SOL9662B has been formulated based on our unique patent-pending SOL9661B glass chemistry, combined with the upgraded organic vehicle system for DP-UFL. This new double print package has the state-of-art formulation with perfectly balanced metallization contact and passivation damaged. As confirmed by customers, with the new screen design, SOL9662B can further narrow the line width to improve the aspect ratio and to reduce the laydown.

KEY BENEFITS

• Ultra-low laydown and high adhesion
• Great printability and superior overlapping
• A+A’ and A+B double-print packages available
• Outstanding efficiency gain through improved Ulta-Fine-Line and contact on Perc with SE
• Improved paste rheology with better finger geometry that can print through (< 18 μm) screen printing

Double-printing for Ultra finger line (DP-ULF) is a technique many c-Si PV cell manufacturers support for improving cell efficiency. Conceptually, double printing

gives them the ability to print very narrow line widths without compromising line quality by printing finger lines on top of each other. This can be technically challenging for both cell manufacturer and metallization paste supplier.

Collaborating with customers, Heraeus Photovoltaic has developed SOL9652B double-print front-side silver paste packages. The SOL9652B package has been formulated

based on our unique patent-pending 9651B glass chemistry, combined with the upgraded organic vehicle system for DP-UFL; This new double print package has the state-of-art paste formulation with perfectly balanced metallization contact and passivation damage.

KEY BENEFITS

• Outstanding efficiency gain through improved ultra-fine-line (DP-UFL) and contact on PERC
• Improved paste rheology with better finger geometry that can print through (< 18 μm) screen opening
• Compatible to different screens design and type (high mesh and Knotless screen);
• Better 1st layer and 2nd layer pastes compatibility and overlapping
• Great yield rate in high throughput mass production (> 350 mm/s) without printing defects
• A+A, A+A’, A+B printing packages available for higher Fill-Factor and Voc
• Flexible packages to balance paste laydown and efficiency under different test conditions

As different passivation technologies were matured in PERC process, such as PECVD (Plasma Enhanced Chemical Vapor Deposition) and ALD (Atomic Layer Deposition), the Alumina oxide and Silicon nitride layers are intentionally (double passivation) or unintentionally (wrap-deposition) stacked on the front-side of silicon solar cell. This has given FS paste more challenges.

Heraeus, the technology leader, closely following the industry trend, has developed the SOL9661B2 series based on the paste chemistry specially designed for stack passivation PERC cell. As confirmed by customers, SOL9661B2 single printing, dual printing and double printing packages provide efficiency gain > 0.10% in mass production. Such paste chemistry provides a wide firing window toward lower temperature side, which makes this series well-performed on PERC and SE-PERC cells.

KEY BENEFITS

• Specially designed paste for “Double Passivation” PERC cell
• High FF, Ultra-Fine-line printability for better efficiency
• Single, Dual and Double printing package available for efficiency boost
• Wide process window
• Allows quick and efficient customization

As different passivation technologies were matured in PERC process, such as PECVD (Plasma Enhanced Chemical Vapor Deposition) and ALD (Atomic Layer Deposition), the Alumina oxide and Silicon nitride layers are intentionally (double passivation) or unintentionally (wrap-deposition) stacked on the front-side of silicon solar cell. This has given FS paste more challenges.

Heraeus, the technology leader, closely following the industry trend, has developed the SOL9651B2 series based on the paste chemistry specially designed for stack passivation PERC cell; As confirmed by customers, SOL9651B2 dual printing and double printing packages provide efficiency gain > 0.15 % in mass production. Such paste chemistry provides a wide firing window toward lower temperature side, which makes this series well performed on PERC cell.

KEY BENEFITS

• High FF, superior contact performance on stack passivation solar cell
• Ultra-fine-line (UFL) screen printing for defect-free mass production
• Wide process window
• Allows quick and efficient customization
• Double and Dual printing packages available
  • A+A’: SOL9652B packages
  • A+B : SOL9651B2/SOL9622B

Heraeus’ newly developed SOL6700 dual printing busbar paste helps to realize higher efficiency and lower manufacturing costs of solar cells. SOL6700 contains a specific glass chemistry, imparting controlled reaction between Ag paste and the dielectric layer. At the same time, because of separate printing of busbar and finger paste, it does not need to consider the height of the busbar area, and allow to do more optimization on screen, to reduce the usage of the silver paste. The SOL6700 is designed to maximize the protection of the dielectric layer of cells from damage during metallization thus contributing to reduce electron recombination and improving the open-circuit voltage. Especially matching with mainstream finger paste on the market at present, can further improve the efficiency when combined with UFL screen printing technology. SOL6700 series, moreover, can be compatible with a variety of mainstream cell technology at present, including Mono PERC, Multi, N-type and so on.

KEY BENEFITS

• Less reactivity into the passivation SiNx and AlOx/SiNx
• Excellent adhesion and wide soldering window
• Compatible with all kinds of mainstream cell technology
• Compatible with Multi Busbar
• Better contact to boost efficiency gain in Multi Busbar

Heraeus’ newly developed SOL6600B dual printing busbar paste helps to realize its higher efficiency and lower manufacturing costs of solar cells. SOL6600B contains a specific glass chemistry, imparting controlled reaction between Ag paste and the dielectric layer. At the same time, on account of separate printing of busbar and finger paste, it does not need to consider the height of the busbar area, and allow to do more optimization on screen, to reduce the usage of the silver paste.

The SOL6600B is designed to maximize the protection of the dielectric layer of cells from damage during metallization thus contributing to reduce electron recombination and improving the open-circuit voltage. Especially matching with mainstream finger paste on

the market at present, can further improve the efficiency when combined with knot-less screen-printing technology. SOL6600B series, moreover, can be compatible with a variety of mainstream cell technology at present, including MCCE, DWC, mono PERC, and so on.

KEY BENEFITS

• Higher efficiency
• Less reactivity into the passivation SiNx and Al2O3/SiOx
• Excellent adhesion and wide soldering window
• Reduce the manufacturing cost of silicon solar cells
• Compatible with all kinds of mainstream cell technology
• No Cd and Pb*