| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a biaxially oriented polyester film, capable of restraining a curl from being generated in high-temperature heat treatment such as solder reflow treatment, even when using any film widthwise position, and usable suitably as applications for an FPC circuit board and electronic equipment. <P>SOLUTION: Average values of thermal shrinkage at 250°C in both end parts and the central part are brought into -1.0% or more to 1.0% or less in both of a TD direction and an MD direction, in a widthwise 100 cm of the biaxially oriented polyester film, and dispersions of heat shrinkage factors are brought into 0.5% or less in the both of the TD direction and the MD direction. <P>COPYRIGHT: (C)2013,JPO&INPIT |
