Outlines:
- Choosing a Cover Glass for Your Display
- Cover Glass Material
- Heat Strengthened Glass
- Chemically Strengthened Glass
- Glass Hardness Scale
- Bonding Type
- Optical Coatings
- Common Types of Cover Glass Material
- Soda-Lime Glass
- Low-Iron Soda Lime Glass
- Aluminosilicate Glass
- Final Words
There are different types of cover glass with various advantages and disadvantages for protecting an LCD display.
The display cover is just as critical as the display itself when developing a new product. The actual display component normally does not receive any protection, leaving it sensitive to environmental factors and damage from continued use. Depending on product requirements, it is often necessary to add a glass cover to protect the display from scratches while maintaining optical quality. However, not all glass is made equal. The strength, cost, color options, and available thicknesses can influence which cover glass to use.
This article will discuss the options for choosing the best cover glass for your display and application.
1. Choosing a Cover Glass For Your Display
The top layer of a display screen module is a cover glass that acts as a protective layer to the internal display properties, allowing the liquid crystal to shine through it and create a visible image. Cover glass can be customized based on the intended display application and come in various materials and strengths of the material, which is usually correlated with scratch resistance.
Read More About Touchscreen Here
The strength of the cover glass is measured by the mineral hardness and determines the material’s scratch resistance. Glass, the standard material, has a 5-7 Mohs hardness rating used for LCD cover glass. Certain industrial and medical applications require a level 7 hardness rating as a safety glass.
LCD cover glass can be customized for any application, and customizations can include strengthening, waterproofing, temperature shielding, and optical enhancements. Different materials can be added to the glass substrate to strengthen the material and prevent scratching the surface. The cover glass also includes special features and printing options.
2. Cover Glass Material
The cover glass is made of a glass substrate or different glass substrates with unique strengths and material properties and strengthened to be more durable depending on the application.
The type of cover glass material used is up to the designer, and each glass type has different advantages, features, and prices that can be changed for the required application.
3. Heat Strengthened Glass
Heat tempered glass is a special process that involves heating the display glass to a liquid at a high temperature, strengthening the glass because the molecules get realigned into a stable pattern. Heat tempered glass heat-tempered glass is a different type of display glass and four times stronger than regular untreated glass.
Heat-treated glass and heat-tempered glass can still be broken in the right conditions, the heat-tempered glass will fragment or crack used in industries for its safety features, and heat-treated glass will break into large and sharp shards.
4. Chemically Strengthened Glass
Chemically strengthened glass is strengthened through chemical bonding; the glass is submerged in chemicals at high heat, enabling ions to bond to holes in the glass. The chemical process adds potassium bonds in the original sodium bonds during this chemical reaction strengthening the glass while maintaining the clarity of the glass. Chemically strengthened glass maintains optical clarity during the strengthening process and can be cut or drilled after treatment.
5. Glass Hardness Scale
The Mohs hardness scale defines the mineral’s scratch resistance and is a way to measure the hardness of a mineral. This is useful for describing the hardness of different LCD glasses typically measured at a hardness level of 5-7 Mohs to create scratch-resistant displays. Certain cover glass materials will have a larger hardness scale and thus be more scratch-resistant.
Soda Lime glass is chemically treated and is a great option for LCDs that do not require extra glass protection. A standard soda-lime glass for an LCD will have a hardness rated at about 5Mohs. This glass is not fragile and will have normal durability, but it is not rated as an extra-strength display glass.
Our cover Glass is chemically strengthened. It provides more damage resistance than standard untreated glass, common in portable electronic devices because it is thin and lightweight and can also be crack-resistant, ideal for handheld devices.
The hardness rating of Dragontrail glass is 7Mohs, which is equivalent to Gorilla Glass and is scratch resistant with this hardness rating. The Dragon glass is durable with a minimum thickness of 1.1mm.
6. Bonding Type
The cover glass is fixed to the LCD with tape or an OCA bonding material. OCA bonding is an optically clear bond applied in a thin layer of about 0.005″ -0.008″ around the bond line that holds the touch panel, cover glass, and LCD together. The adhesive is clear and will dry without staining the display’s glass and is good for delicate materials such as cover glass and touchscreens.
7. Optical Coatings
Special features and optical coatings on the display’s cover glass can provide moisture protection and dust prevention and increase the display’s durability. The optical coating acts as a protective layer to the display’s internal circuitry and liquid crystal and acts as an adhesive to prevent moisture or dust from entering the section. The cover glass can have an extra layer of protection with an optical coating. The optical coating can protect against external elements and recommend outdoor display applications. The sealing effect of the optical coating will protect the display from harsh conditions.
8. Common Types of Cover Glass Material
Here are the most common types of cover glass used for display modules described below:
- Soda-lime glass
- Low-Iron soda-lime glass
- Aluminosilicate glass
Read More About Cover Glass in detail here.
9. Soda-Lime Glass
Soda-lime glass, also known as soda-lime float glass, is the most frequently used glass in display modules. Soda Lime glass has the features of standard glass and is the most common material you typically see used in windows. This type of glass is strong and cost-efficient, and it can range in thickness like other glasses.
10. Low-Iron Soda Lime Glass
The same strength is slightly more expensive than conventional soda-lime float glass, and low iron soda-lime glass is more transparent and almost tint-free. This glass is commonly used as a cover for any product with a lighter white color around the display since there is no green hue to distort the coloring.
11. Aluminosilicate Glass
Aluminosilicate glass, commonly known as Gorilla Glass™ or Dragontrail™ glass.
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Gorilla Glass
Gorilla Glass is a thin, lightweight, yet strong material. Gorilla Glass is scratch-resistant and damage resistant, and the typical applications for Gorilla Glass include smartwatches, smartphones, and tablets. Gorilla Glass can also be used for industrial and military applications where the display’s durability is essential.
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Dragon Glass
Dragon glass is a type of cover glass treated with chemicals and heat to improve the strength of the material. The glass material is mixed with strengthening particles and heated to a liquid. This chemical and heat strengthening process makes this cover glass scratch-proof and durable. This cover glass is six times as strong as the standard soda-lime glass.
12. Final Words
Whether your biggest concern is thickness, cost, color, or any other combination of factors, createxplay experts can help you find the perfect cover glass for your display. Please find out more about our display integration capabilities by setting up a consultation with our experts.
