AG Paste (Silver Metallization Paste)

For front and back bus contact

Better yields and higher outputs for solar cell manufacturers.

In partnership with Heraeus, Targray offers the HeraSol Ag paste compositions.

These silver metallization pastes are customizable to your process, thus increasing efficiency and fill factor while providing wider processing windows.

The HeraSol compositions are a series of screen-printable front and back side silver conductors for crystalline solar cells. The front side formulation is ideal for lightly-doped emitter designs and optimized for high throughput processing to deliver excellent aspect ratios and fine line resolution. For back side solder applications, the new lead-free silver paste significantly lowers material consumption due to high coverage and excellent initial and soldered age adhesion.

Benefits

• Targray’s HeraSol Ag metallization pastes are all very high quality and uniformly consistent from batch to batch.
• Customizable to your unique wafer design and processes.
• All formulations cadmium-free. Lead-free pastes also available.
• Formulations suitable for SiNx or TiOx anti-reflective coatings are available.
• Co-fireable with commercial back side Ag/Al pastes.

Customized AG paste solutions

Targray offers a variety of standard formulations or tailor-made Ag paste solutions for optimal concordance with your particular needs..
Heraeus’ state-of-the-art paste manufacturing technology allows fine-tuning of the size, shape and distribution of particles for optimum paste performance.  All of our Heraeus Silver metallization pastes are specially formulated to provide higher efficiencies and wider processing windows, resulting in better yields and higher output for cell manufacturers

	SOL950	SOL952	SOL953	SOL930	SOL230
Description	Front side Ag conductive paste for general application	Front side Ag conductive paste	Front side Ag conductive paste for high sheet resistance emitter	Pb-Free front side Ag conductive paste	Back-side Ag paste for solderable busbar application
Wafer sheet resistance	= 45 ohms/sq	= 70 ohms/sq	= 80 ohms/sq. shallow emitter	<70 ohms/sq
Glass frits	Cd free	Cd free	Cd free	Cd free, Pb free	Cd free, Pb free
Viscosity*	180 – 220 kcps	180 – 240 kcps	180 – 240 kcps	160 – 260 kcps	100 – 160 kcps
Solid contents	83.0 ± 1%	84.0 ± 1%	84.5 ± 1%	81.5 ± 1%	71.5 ± 1%
Solder alloy	Sn62 / Pb36 / Ag2 or Sn96.5 / Ag3.0 / Cu0.5
Wafer types	monocrystalline and multicrystalline silicon
Wafer surface treatment	Textured/planar	Textured	Textured	Textured	Textured/planar
Anti-reflection coating	SiNx:H	SiNx:H	SiNx:H	SiNx:H
Print screen	280 – 325 mesh S/S screen
Screen emulsion thinkness	15 µm – 25 µm	20 µm – 30 µm	20 µm – 30 µm	18 µm – 25 µm	10 µm – 15 µm
Drying	150°C for 10 minutes in circulated air oven or 250 – 300°C for 20 seconds in belt dryer
Firing	IR belt furnace, Spike Fire
Peak firing temperature** (not setpoint temperature)	750 – 790°C	740 – 800°C	740 – 800°C	750 – 790°C	725 – 825°C
Print line resolution (finger width)	= 100 µm	= 100 µm	= 80 µm	= 100 µm
Fired film thickness	10 µm - 16 µm	15 µm - 20 µm	15 µm - 25 µm	12 µm - 18 µm	= 7 µm
Shelf life	6 months
Storage	5 – 25° C.   Do not refrigerate. Allow paste to come to room temperature prior to opening. Spatulate well before using

SOL 950 Product Specifications (.PDF)
SOL 952 Product Specifications (.PDF)
SOL 953 Product Specifications (.PDF)
SOL 230 Product Specifications (.PDF)

Please ask us about our latest generation of paste for high sheet resistance wafers – CL80-9235H. Capture an increased efficiency with this cutting edge Ag paste.