Touch screen bonding process that suppresses Newton rings

Abstract

The invention discloses a touch screen bonding process for suppressing the generation of Newton's rings. The ITO conductive film that has been screen-printed is allowed to stand for 12 hours under the conditions of a temperature of 22° C.±5° C. and a humidity of 40%-75% to make the ITO film. The conductive film fully absorbs moisture, and the ITO conductive film is attached to the ITO glass on the negative pressure vacuum workbench. The lamination process conditions of the negative pressure vacuum workbench are: vacuum degree: ‑0.15±0.02Mpa, Vacuum suction time: 13±5S, bonding pressure: 0.22±0.04Mpa, bonding maintenance time: 60±10S. After fully absorbing moisture, the ITO conductive film remains completely flat and no longer deforms. Therefore, the touch screen formed after lamination will no longer collapse due to the deformation of the ITO conductive film, thereby avoiding Newton's rings. production.

Description

technical field [0001] The invention relates to the field of touch screen manufacturing, in particular to a touch screen bonding process for suppressing the generation of Newton's rings. Background technique [0002] In the field of industrial automation, touch screens are widely used as human-machine interfaces, and the requirements are getting higher and higher. Customers require the service life of the products to be more than 10 years, and the environmental conditions during use are also high. General requirements: temperature -30°C-85°C , and the humidity is 90% RH at 40°C. Judging from user feedback, some touch screens are very normal at the beginning of use under extreme conditions, but after a period of use, the Newton ring phenomenon (an optical phenomenon that occurs after the touch surface partially collapses), and then after a long period of use The upper and lower layers of the touch screen are short-circuited directly and cannot be used, that is, the touch scr...

AI Technical Summary

Problems solved by technology

[0003] By collecting a large amount of user feedback information on the above problems and conducting data analysis, we found a common feature: touch screens made of ITO conductive films produced in Japan will not have the above problems, but ITO conductive films produced by Taiwan and domestic companies The touch screen produced by the film will have the above problems, which shows that the materials of the two ITO conductive films are different

[0004] Why are there such big differences between these two ITO conductive films? Through the analysis of these two types of film materials, it is found that although the main components of both are PET film (content above 87%), and the PET film has water absorption characteristics, the thickness of the hardened layer on the PET of the two types of ITO conductive films is different. The experimental verification of ITO conductive films of two types of materials found that: under the same printing and heating conditions, the two types of materials were produced to the pre-lamination process, and it can be seen that both ITO conductive films have obvious positive warpage (around Warping towards the ITO surface), there is no difference between the two, but after the two films are left to stand for 12 hours under normal temperature and humidity conditions, although the ITO conductive film made in Japan absorbs water but because of the thick hardened layer, its The positive warping phenomenon basically remains unchanged, while the ITO conductive film PET produced by Taiwan and domestic enterprises becomes completely flat and no longer warped because of the thin hardened layer after absorbing water! That is to say, the latter is more likely to deform due to water absorption. That is to say, if the ITO conductive film produced by Taiwan and domestic enterprises is not allowed to stand for enough time, if the bonding operation is carried out without absorbing enough water, it will look warped. The touch screen made of curved ITO conductive film absorbs water after being used in a normal temperature and humidity environment, and the positive warping will gradually disappear. Newton rings will gradually appear, which will eventually lead to a shortened product life.