Transparent Stainless Steel?

    Well, not exactly. HTI’s fine etching capability is being demonstrated by Keith Johnson, HTI Director of Marketing & New Business Development. This sheet of 40 micrometer thick stainless steel has been chemically etched with a pattern of over 8 million 55 micrometer (~ 2mil) holes in an 8″ square area. The holes are so small and packed so densely that they are not able to be perceived by the naked eye, causing the metal to appear transparent. HTI’s fine screen etching capability is currently being used for solar and fluid filtering applications, but can also be used in medical, aerospace, food processing, and many other industries requiring durability and precision. This particular screen is used in the solar industry to print silver conductors on crystalline cells. A patterned emulsion is placed over the screen leaving tiny one hole wide lines where the silver ink is screen printed through. Etched screens are much more consistent and durable than standard mesh screens and enable more print cycles and reduced silver ink consumption. Additionally, HTI’s ability to make smaller holes than standard mesh enabled a reduction in the conductor size. For solar cells this is critical, since the conductors are on top of the cell and block light from entering the cell, therefore improving efficiency.