Progress in optical adhesive and lamination process of touch screen in 3C products

Compared with the traditional keyboard and mouse input method, touch screen technique has high convenience for users. With the development of technology, touch screen is widely application in various electronic products because of their high transmittance, clear images, and convenient operation. This review mainly introduces the optical clear adhesive (OCA), liquid optical clear adhesive (LOCA), and the most commonly used LOCA ultra violet (UV)-curable adhesives. Preparation and performance of UV-curable adhesives are deeply explored. The structure of touch screen, such as one glass solution (OGS), on-cell and in-cell is discussed. Moreover, lamination process includes full lamination and non-full lamination is also discussed. This review introduces the alignment technique comprise mechanical alignment technique and non-mechanical alignment technique (such as machine vision) and laminating equipment. The recent development and existing problems with the touch screen lamination process are discussed. Furthermore, this review describes the latest developments in the adhesive of touch screen lamination process and predicts possible future development trends, which could provide references for subsequent research work.