[iPad mini Teardown (3)] Film Substrate Employed for Touch Panel
Continued from [iPad mini Teardown (2)] 60% Lower Battery Capacity
Nikkei Electronics Teardown Squad succeeded in the teardown of Apple Inc's iPad mini without serious trouble and started to examine its major components.
One of the features of the iPad mini is the capacitive touch panel that is attached to the cover glass with an adhesive. The touch panel of the iPad mini uses a film (resin) substrate instead of a glass substrate.
One of the advantages of replacing a glass substrate with a film is that it becomes possible to reduce the thickness of a touch panel. The thickness of the iPad mini's cover glass combined with its touch panel is about 0.8mm, which is about 0.5mm slimmer than in the case of the third-generation iPad (about 1.3mm), which uses a glass substrate for its touch panel.
So, it can be said that the film contributed to the thickness reduction though not as much as the in-cell technology that embeds a touch panel function in an LCD panel and has been employed for the iPhone 5 smartphone.
Also, the two touch controller chips of the iPad mini's touch panel are positioned on a printed circuit board (PCB) mounted on the flexible printed circuit (FPC) board that connects the touch panel and the main board. In the previous three types of the iPad series, touch controller chips are mounted on their main boards.
We assumed that Apple changed the location of the chips to improve touch panel sensitivity or in response to the reduction in thickness. The two touch controller chips of the iPad mini were made by Broadcom Corp.
We went on to examine the other major components of the iPad mini.