Surface Treatment
Surface Treatment Lineup
We provide several different kinds of surface treatment according to the application and purpose.
Among these, we have developed surface treatments matched to low-permittivity resin for high frequency and high transfer speed applications.
Surface Treatment | BHY | GHY5 | BHM | BHFX |
---|---|---|---|---|
Features | Standard treatment | Low roughness | Circuit patterning properties | Low transmission loss |
(Visibility) | Low transmission loss | |||
Matte surface roughness (For reference: 12 µm copper foil) |
Rz : 0.70µm | Rz : 0.40µm | Rz : 0.70µm | Rz : 0.75µm |
Resin | PI | PI, MPI | PI, MPI | LCP, PTFE |
- Data for matte surface roughness are typical values.
BHM Surface Treatment for High Frequency Use

We developed BHM surface treatment, evaluated by customers for its high frequency performance and suitability for fine pitch circuit patterning. BHM can be applied on our HA, HA-V2, and HG treated rolled copper foils, as well as on JXEFL electro-deposited copper foil for FPC use.
GHY5 Treatment for Ultra Fine Nodules: Improved FPC Visibility
This treatment produces an ultra-fine foil featuring lower roughness surface than conventional BHY treated foils. It results in a highly transparent polyimide film substrate after chemical removal of the FCCL copper foil etching pattern. Excellent visibility is achieved in FPC positioning processes for 50 µm polyimide substrate and multilayer substrate.
Polyimide substrate transparency

Inquiries accepted 24 hours a day.