Photolithography in Eyewear Manufacturing

2025,05,14

Technical principle and realization path

Dazzle lithography is based on the optical principle of micro-nano structure, through the construction of periodic micro-nano texture on the surface of the mold (feature size 0.5-5μm), the use of light interference and diffraction effects to achieve specific optical effects. As the process can not directly act on the plastic substrate, the need to use “mold lithography - injection transfer” two-step method: first in the nickel alloy or silicone-based mold surface through the photoresist exposure, development, etching and other processes to form the design texture, hard chrome plating treatment to enhance wear resistance, used for optical lenses or frames of the injection molding, so that the surface of the product The surface of the product will have the same micro-nano structure as that of the mold.

Photolithography in Eyewear Manufacturing

Technical parameters of lens application

In the manufacture of optical lenses, this technology is mainly applied to non-functional surface area. PC lenses, for example, can be realized after injection molding by photolithography:

Optical performance: in the 400-760nm visible light band, the light transmittance remains ≥90% (in line with GB 10810.3 standard), haze <1%, to meet the requirements of optical performance of the lens
Surface precision: micro-nanostructure replication accuracy of ±50nm, to ensure the uniformity of the color effect
Durability: Passed 500 hours xenon lamp aging test, no obvious color fading or structural damage.
Typical case is a customized water drop texture lens for an eyeglasses factory, the mold adopts electron beam lithography technology to make the master plate, and after 2,000 injection cycles, the surface contour error of the product is still controlled within ±150nm, and batch production is realized.

Innovation of mirror frame manufacturing process

In the field of mirror frame manufacturing, photolithography is mainly used in decorative surface treatment. By building geometric texture or brand logo on the mold surface, it can be formed after injection molding:

Surface roughness: Ra value 0.2-0.5μm, to realize mirror-level reflective effect
Color rendering: By adjusting the cycle parameters of the micro-nano structure, structural colors in the 450-650nm wavelength range can be produced.
Adhesion: Class 5B by ASTM D3359 to meet the needs of daily use.

A high-end mirror frame project adopts photolithography technology to realize gradient rainbow effect. By controlling the micro-nano structure cycle in different areas of the mold, continuous spectral reflection is formed on the surface of the mirror legs, and the production cost is 30% lower than that of traditional vacuum coating process.

Advantages of industrialized application

Mass production stability: lithography mold life can reach more than 100,000 times, the coefficient of variation of copying accuracy <3%.
Process integration: can be combined with two-color injection molding, insert molding and other processes to achieve functional and decorative integration
Environmental characteristics: no electroplating, spraying and other chemical processes, in line with RoHS 2.0 environmental standards.

At present, this technology has realized the adaptation of PC, PMMA and other mainstream eyeglasses materials, providing differentiated surface solutions for eyeglasses products under the premise of guaranteeing optical performance and mechanical strength.

Author:

Ms. Annie Liu

E-mail:

sales@mlmeyewear.com

Phone/WhatsApp:

+86 13829903822