SOLAR TEMPERED GLASS

Product Overview

Solar tempered glass is low-iron (ultra-clear) glass specifically produced for photovoltaic modules. It is used as the front cover glass of crystalline silicon modules and as the front/rear glass of dual-glass (glass–glass) modules. The glass is fully tempered to provide mechanical strength, thermal-shock resistance, and impact safety required in outdoor PV service.

The product is supplied in standard thicknesses of 2.0 mm, 2.5 mm, and 3.2 mm, and is available in uncoated and AR-coated versions. Processing options include silk-screen printing and hole drilling.

Optical Performance — Light Transmittance

Light transmittance is a primary performance parameter of solar glass, as it directly affects the irradiance reaching the solar cells and therefore module power output.

Notes (objective):

• Transmittance is measured under standard solar spectral conditions for PV glass (commonly referenced to ISO / IEC solar glass practice; exact test method and wavelength range should be confirmed on the inspection report for each lot).
• Values vary slightly with thickness: thinner glass generally shows a small transmittance advantage at equal iron content and coating design.
• After tempering and optional silk-screen / AR processes, final transmittance is verified against the agreed specification for the order.

Thickness Options

Thickness tolerance is controlled per drawing / order agreement (typical industrial tolerance for solar glass is on the order of ±0.2 mm for common thicknesses; confirm on the technical data sheet).

Silk-Screen Printing

The glass supports high-temperature ceramic frit silk-screen printing before tempering.

Typical uses:

• White or black grid / mesh glaze on dual-glass rear glass to improve light reflection into the cell gaps
• Edge / busbar masking and aesthetic patterns
• Custom patterns per customer artwork

The printed frit is fired during the tempering cycle, forming a durable, chemically bonded layer with good weather and abrasion resistance under normal module operating conditions. Print pattern, color, coverage ratio, and reflectivity (for white glaze) are defined by customer drawings.

Hole Drilling / Openings

Holes and openings can be processed before tempering, including:

• Junction-box cable holes
• Mounting / positioning holes
• Custom cut-outs per module design

Hole diameter, position tolerance, edge finishing, and quantity are executed according to the approved drawing. All drilling and edge work is completed prior to tempering to avoid post-temper breakage risk.

Coating Options

1. Uncoated Solar Tempered Glass

• Low-iron ultra-clear substrate
• Solar transmittance typically ≥ 91.5% (3.2 mm class)
• No AR film; surface remains as tempered glass finish (patterned or float, as specified)
• Suitable for applications that do not require AR coating, or where coating will be managed separately

2. AR-Coated Solar Tempered Glass

• Anti-reflective coating applied to one or both faces as specified
• Solar transmittance typically ≥ 93.5% – 94.0% (depending on coating system and glass thickness)
• Reduces first-surface reflection and increases light available to the cells
• Coating durability and adhesion are verified after tempering per product specification

Mechanical & Safety Characteristics (Tempered)

• Fully tempered safety glass for PV use
• Higher bending strength and impact resistance than annealed glass of the same thickness
• When broken, fragments into small granular pieces (safety fracture mode)
• Suitable for outdoor exposure in combination with standard PV encapsulants and framing / dual-glass structures

Surface stress, bow/warp, and fragment density are controlled to agreed PV-glass standards and customer drawings.

Processing Capability Summary

Applications

• Front cover glass for crystalline silicon PV modules
• Front and rear glass for dual-glass (bifacial) modules
• Thin dual-glass and lightweight module designs (2.0 / 2.5 mm)
• Modules requiring silk-screened rear glass and/or pre-drilled openings

Ordering Information

Please specify when ordering:

1. Thickness: 2.0 / 2.5 / 3.2 mm
2. Coating: uncoated or AR-coated
3. Silk-screen: yes/no, and artwork / coverage if required
4. Holes: yes/no, with dimensional drawing
5. Size, edge finish, patterned or float surface, and packaging requirements

Final optical and dimensional acceptance criteria are as stated on the contract / inspection report for each shipment.