Patent ID: 7361705
Filing Date: 2008-04-22
Classification: C08K,H05K,Y10S,Y10T

Abstract:
1. A flexible circuit board incorporating a heat-resistant film formed from a thermoplastic resin composition comprising: (A) a thermoplastic resin having a melting temperature of 300° C. or above, and (B) a platy inorganic filler incorporated in the thermoplastic resin and having the following properties: pH of aqueous dispersion: which is determined by metering a 1 g sample into a 100 ml beaker, introducing 100 ml of deionized water into the beaker, stirring the beaker content by a magnetic stirrer for 10 minutes, and then measuring its pH by a nH meter: 5.5-8.0, amount of extracted alkalis: which is determined by dispersing a 1 g sample in 100 ml water and stirring the resulting aqueous dispersion at room temperature for 1 hour and filtering it through a No. 5 filter gaper to obtain a filtrate which subsequently is measured by atomic absorption spectrometry: Na 30 ppm or below and K 40 ppm or below, maximum diameter a: 50 μm or below, thickness b: 1.0 μm or below, and aspect ratio (a/b): 20 or above wherein said platy inorganic filler is incorporated in said thermoplastic resin, and said resin composition has thermal plasticity.