Combination of mold and release film, release film, mold, and method for manufacturing molded article
An object of the invention is to provide a method for conditioning a surface of a molded article. The present invention relates to a combination of a mold used for curing a thermosetting resin and a release film placed between the thermosetting resin and the mold during the curing. The release film comprises a base layer formed of a thermoplastic resin and a surface layer formed of a particle-containing fluororesin and laminated to the face which is placed during the curing on the side of the thermosetting resin among the two faces of the base layer. The mold has an irregularity formed on the face brought into contact with the release film during the curing.
1. A combination, comprising:
a mold used for curing a thermosetting resin, and
a release film placed between the thermosetting resin and the mold during curing, wherein:
the release film comprises:
a base layer formed of a thermoplastic resin, and
a surface layer formed of a particle-containing fluororesin and having a surface shape attributable to particles contained in the surface layer,
the fluororesin of the surface layer comprises an isocyanate curing agent and a tetrafluoroethylene resin,
said isocyanate curing agent is a combination of an isocyanurate-type polyisocyanate and an adduct-type polyisocyanate having a mass ratio of 10:6 to 10:10,
the surface layer is laminated to a face of the base layer,
the face is placed on a side of the thermosetting resin during the curing,
the particles are inorganic particles, and an average particle size of the particles determined by laser diffraction particle size analysis is 1 μm to 10 μm,
the mold has an irregularity formed on the face that is brought into contact with the release film during the curing, and
a surface roughness Ra of the face of the mold is 1 μm to 4 μm.
2. The combination according to claim 1 , wherein the particles are silicon dioxide.
3. The combination according to claim 1 , wherein the thermoplastic resin of the base layer is a polyethylene terephthalate resin.
4. The combination according to claim 1 , wherein the thermosetting resin is an epoxy resin.
5. The combination according to claim 1 , which is used in a method of manufacturing a molded article that has an irregularity on a surface of the molded article, the method comprising:
a placing step for placing the release film in the mold used for curing the thermosetting resin,
a curing step, after the placing step, for curing the thermosetting resin, while being in contact with the release film, in the mold to form the molded article, and
a releasing step, after the curing step, for releasing the molded article from the mold thereby obtaining the molded article.
6. The combination according to claim 5 , wherein the irregularity formed on the surface of the molded article is different from the irregularity of the mold.
7. The combination according to claim 5 , wherein the method is transfer molding process or compression molding process.
8. The combination according to claim 5 , wherein in the method, semiconductor devices are sealed in the molded article.
9. The combination according to claim 5 , wherein the molded article has a surface whose glossiness at an incidence angle of 60 degrees is 3 to 50.
10. The combination according to claim 1 , wherein the tensile breaking strength of the release film is 40 MPa to 200 MPa, as determined at 175° C. in accordance with JIS K7127.
11. The combination according to claim 1 , wherein the tensile elongation at break of the release film is 200% to 500%, as determined at 175° C. in accordance with JIS K7127.
12. The combination according to claim 1 , wherein the particle on the surface layer of the molded body side are present in an amount of 16 parts by mass or less per 100 parts by mass of fluorinated resin.