| 摘要 |
PURPOSE:To obtain a carrier film, excellent in adhesiveness and mold releasability and suitable for use in transfer molded wiring boards by making a specific wax present in a polyester film, reducing heat shrinkage of the above- mentioned film and specifying the film thickness. CONSTITUTION:A biaxially oriented polyester film (e.g., polyethylene terephthalate), obtained by containing 0.1-3wt.%, preferably 0.3-2wt.% wax (e.g., montanic acid ester wax) consisting essentially of a 50-100C ester compound containing a >=20C higher fatty acid as an acid component and a >=20C higher alcohol or >=2C polyol as an alcohol component and having <=0.5%, preferably <=0.1% heat shrinkage factor (150 deg.C) and 25-150mu, preferably 50-100mu thickness. |
