US Patent:
20210301086, Sep 30, 2021
Inventors:
- Wilmington DE, US
THOMAS EDWARD CARNEY - Orient OH, US
JOSEPH CASEY JOHNSON - Pickerington OH, US
LIN JU - Grove City OH, US
MICHAEL THOMAS KWASNY - Columbus OH, US
LAILA MACLAUGHLIN - Stoutsville OH, US
GRZEGORZ SLAWINSKI - Fairborn OH, US
International Classification:
C08G 73/10
C08K 3/04
C08K 5/00
C08K 5/17
C08J 5/18
C08L 79/08
Abstract:
In a first aspect, a single layer polymer film includes 60 to 99 wt % of a crosslinked polyimide, having a gel fraction in the range of from 20 to 100% and a refractive index of 1.74 or less, and 1 to 40 wt % of a colorant. A surface of the single layer polymer film has been textured and has a maximum roughness (S) of 6 μm or more, an L* color of 30 or less and a 60 gloss of 15 or less. In a second aspect, a coverlay for a printed circuit board includes the single layer polymer film of the first aspect. In third and fourth aspects, processes are disclosed for forming a single layer polymer film including a crosslinked polyimide film including a dianhydride and a diamine.