A hot pressing method has been known as a method intended for bonding of sheets or heat transfer of a transfer layer coated on a film. For example, in the case of performing hot pressing, such as bonding or heat sealing of an anisotropic conductive film (ACF) or bonding of electronic components such as FPC, thermal distribution in the press surfaces may affect the quality of manufactured products.
On the occasion of manufacturing by performing hot pressing, in order to enhance the quality of manufactured products and to shorten the tact time required in manufacturing, it is important to manage the temperature and the temperature distribution at the hot-press surfaces to attain adequate values. In order to do so, an operation of measuring the actual temperature and regulating the temperature according to the temperature distribution that has occurred, is required.
However, for the tracing of the temperature distribution in pressed surfaces, a method of measuring the temperature by interposing, between hot pressed surfaces, a pseudo-surface temperature sensor that is formed by disposing a number of thermocouples, resistance temperature detectors, thermistors or the like on a sheet or a plate member, has been carried out (see, for example, Japanese Patent Application Laid-Open (JP-A) No. H5-52666).
Furthermore, as a sheet or method for checking the temperature of a large hot surface, there has been suggested a temperature measurement method that is carried out by providing a hot pressing process of superposing a thermosensitive sheet on an article to be processed or within the material of the article, supplying the article between hot-press surfaces that face each other, and performing hot pressing; a density measurement process of measuring the density of measurement sites at the thermosensitive sheet after performing hot pressing; and a temperature calculation process of calculating the heating temperature of the hot press based on the density thus measured (see, for example, JP-A No. 2004-117145).
Furthermore, in recent years, a thermal distribution measurement film (THERMOSCALE) that develops black color when heat is applied thereto has been marketed, and a method which allows investigation of the heat quantity distribution of a contacting surface has been provided.