In a liquid crystal display (LCD) device, a display region is formed such that a TFT substrate over which pixel electrodes and thin-film transistors (TFTs), inter alia, are formed in a matrix and an opposing substrate over which color filters, inter alia, are formed in positions corresponding to the pixel electrodes in the TFT substrate are placed facing each other and liquid crystals are sandwiched between the TFT substrate and the opposing substrate. An image is produced by controlling light transmissibility through liquid crystal molecules pixel by pixel.
A miniature display of a mobile phone or the like is strongly required to be made thinner, which thus results in a strong demand for making a liquid crystal display device thinner. Therefore, thinning a liquid crystal display panel is pursued in addition to thinning a backlight and decreasing the thickness of a metal frame forming a casing.
A liquid crystal display panel has a structure such that a liquid crystal layer is sandwiched between the TFT substrate and the opposing substrate and a lower polarizing plate is attached to the underside of the TFT substrate, while an upper polarizing plate is attached to the upper surface of the opposing substrate, and this area defines the display region. The TFT substrate is formed larger than the opposing substrate and, in a terminal section where the opposing substrate does not extend over the TFT substrate, an IC driver is installed and a flexible wiring board is connected.
The terminal section of the TFT substrate is weak in mechanical strength, because it is made of a single glass plate. In order to decrease the thickness of the liquid crystal display panel, the liquid crystal display panel is ground to decrease its thickness after the panel is finished. In the manufacturing process of the liquid crystal display panel, for example, if the TFT substrate and the opposing substrate are made so that their glass plates each have a thickness of 0.5 mm, the TFT substrate and the opposing substrate, together, will be about 1 mm thick.
For such liquid crystal display panel, both the TFT substrate and the opposing substrate are thinned to be about 0.2 mm thick, respectively, by grinding the outer surfaces of the TFT substrate and the opposing substrate. In this case, an area where the TFT substrate and the opposing substrate are superposed on each other has a thickness of about 0.4 mm, but the terminal section where the TFT substrate only extends just has a thickness of about 0.2 mm. Further, the area where the TFT substrate and the opposing substrate are superposed on each other defines the display region and the polarizing plates with a thickness of about 0.13 mm, respectively, are attached to the substrates. Hence, when comparing the mechanical strength of the terminal section of the TFT substrate with that of the area where the TFT substrate and the opposing substrate are superposed on each other, the strength of the terminal section where the TFT substrate only extends is very small.
The terminal section is easy to warp, because its glass plate thickness is very small. Meanwhile, the IC driver is installed in the terminal section. When the glass is warped by an external force, the IC driver is also warped. However, because silicon of which the IC driver is made is not so much warped as glass, there also arises a problem that the IC driver may be broken when an external force is exerted on the terminal section.
In Japanese Published Unexamined Patent Application No. 2005-274632, an arrangement is described such that a front frame having an emboss portion is placed over the IC driver section. This arrangement is to restrain warping of the terminal section and to mechanically protect the IC driver by the emboss portion formed in the front frame.