Ultra Fine Etching COF

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Ultra Fine Etching COF

Fine pitch has been demanded for the display drivers because of the year-by-year evolution of pixel density and panel size in display products.

By conventional etching technology, the shape of cross-sectioned leads become trapezoid due to effect of side etching, especially in the case of fine pitch. This would affect on the reliability of connection between the leads and glass of display.
Ultra Fine Circuit by Anisotropic Etching In order to solve the issue above, anisotropic etching technology, so called "Ultra Fine Etching", was introduced. By the technology fine pitch circuit such as in 23um pitch or less was realized in high volume production, which it is difficult to achieve by the conventional etching.

  • SEM Image of Cross Section (Min Pitch 20 (um) Leads by Ultra Fine Etching

    SEM Image of Cross Section

"Straight Wall" Lead Shape In the area of ultra fine etching, anisotropic etching, (that is, etching in horizontal direction is limited and as a result etching in vertical direction becomes dominant), realizes the "Straight Wall" shape of leads.