Optical bonding of the touch sensor, cover glass and the display are made possible by means of different bonding technologies. At our site in Weikersheim, the bonding process was continuously developed along with the production of PCAP touch sensors and the possibility to bond these with custom-made cover glass. The bonding process takes place in a cleanroom where the air gap between the touch sensor and the cover glass is replaced with a transparent adhesive to guarantee error-free touch functionality. Touch front assembly of the display unit also takes place in a cleanroom and varies between air bonding or full bonding, depending on customer requirements.
During the process of air bonding, the components are bonded to the display by means of a double-sided industrial adhesive. In the full bonding process, the air gap between the components is bonded with transparent adhesive. Full bonding technology requires a high degree of expertise in order to improve optical display characteristics and minimize reflection.