Patent Application
20080088768
102—liquid crystal display panel; 103—control circuit substrate; 104—hole at the tip of the slit; 105—slit; 106—drive chip; 112—COF mounting film for a liquid crystal display drive chip; 121—line that is substantially parallel to the engaging side of the liquid crystal display panel with the COF mounting films for drive chips; W11, W12 and W13—distance between the control circuit substrate and the liquid crystal display panel at different positions.
Embodiments of the present invention will be described hereinafter with reference to accompany drawings.
In
The COF mounting films for liquid crystal display drive chips 112 according to one embodiment of the present invention each is provided with a slit 105 and a circular hole is defined at the tip of the slit 105. With adjusting the opening degree of the slit, identical COF mounting films for liquid crystal display drive chips may be arranged between the liquid crystal panel and the control circuit substrate, even though the distance between the liquid crystal panel and the control circuit substrate varies with position. Furthermore, the film material around the slit is prevented from cranking caused by stress concentration, since the circular hole provided at the tip of the slit may disperse stresses in this region regardless of the slit is opened or closed.
The slit is preferably cut along a direction that is substantially parallel to the engaging side of the liquid crystal display panel 102 with the COF mounting films for liquid crystal display drive chips. Alternatively, the slit may be cut along a direction that is substantially parallel to the engaging side of the control circuit substrate 103 with the COF mounting films for liquid crystal display drive chips. Therefore, the slit may be opened according to the variation of the distance between the liquid crystal display panel and the control circuit substrate.
More preferably, equal-numbered slits are respectively provided on the two opposite, non-engaging sides of the COF mounting films for liquid crystal display drive chips, i.e., the two sides which do not engage with either the liquid crystal display panel 102 or the control circuit substrate 103. Therefore, variation of the distance at the two opposite sides may be equally accommodated by opening and closing of respective slits.
Hereinafter, a method for manufacturing a COF mounting film for a liquid crystal display drive chips will be described. The description will be only directed to a characterizing part thereof.
In
The slit is formed in the base film 402 at the region which is outside of the region 401 and also outside of the region 403 and the direction of the slit is substantially parallel to that of the region 403 where an I/O pad is provided.
As to methods for forming the slit, it can be envisaged that a weakened line is preformed. That is to say, the slit is not physically cut. Instead, when needed, moderate forces may be applied to break the weakened line so as to form the slit. This embodiment is advantageous in that: it is quite difficult to mount a drive chip on the film provided with a cut or opened slit; however, mounting a drive chip on the film provided with a weakened line is relatively simply. The drive chip may be mounted even though the film has been provided with the weakened line. Therefore, the procedure of providing the weakened line may be carried out prior to or after the mounting procedure of the drive chip, thus increasing a degree of freedom in the manufacturing process. Furthermore, as compared with the case of forming a cut or opened slit, only providing a weakened line is relatively easy to perform connection operation during the COF mounting film for liquid crystal display drive chip is mounted on the substrate.
By the way, for the case where the slit is physically cut on the film, this slit needs to be formed after the drive chip has been mounted onto the film.
The shape of the slit will be described further hereinafter.
The optimized method lies in that a region around the slit and the hole at the tip of the slit is coated with solder resist or provided with dummy wirings. These provisions of the solder resist or dummy wirings may optimize the slit region. Furthermore, it may incorporate the procedure for coating the solder resist or providing dummy wirings into current manufacturing process, without offering a further procedure. Thus, the manufacturing cost of the COF film will be not increased.
When the slit is not completely cut open, its presence will not adversely affect the mounting of the drive chip. Furthermore, when the COF mounting film for a liquid crystal display drive chip is used to perform a connection operation, a slit not completely cut open may facilitate the connection operation.
In such a case, the drive chip may be mounted even after the weakened line has been provided.
Besides, formation of the slit and weakened line as well as manufacturing of the COF mounting film for a liquid crystal display drive chip according to one embodiment of the present invention are well known to those skilled in the art. Therefore, a detailed description is omitted. Furthermore, the COF film is made of conventional materials, such as polyimide.
Obviously, the present invention is not limited to providing COF films between a liquid crystal display panel and a control circuit substrate; it may also be applied to providing COF films between two substrates separated by a variable distance, with the COF film is arranged between the two substrates.
The embodiment described above is merely used to explain the principle of the invention. It can be appreciated that the present invention is not limited thereto. For those skilled in the art, various variations and modifications which are made without departing from the spirit and the scope of the invention shall fall within the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-281036 | Oct 2006 | JP | national |
