Mitsuru Tahara

Preparation of PTFE Film With Adhesive Surface Treated by Atmospheric-Pressure Nonthermal Plasma Graft Polymerization

A surface modification technique that improves the adhesion of fluorocarbon polymer films such as polytetrafluoroethylene (PTFE), perfluoroalkoxy fluoroplastics, and polychlorotrifluoroethylene is developed using argon at atmospheric pressure and acrylic acid vapor nonthermal plasma. The results of the T-type peeling test show that the peeling strength of the treated PTFE film is approximately 70 times greater than that of the untreated film. From X-ray photoelectron spectroscopy and scanning electron microscope analyses, it is confirmed that chemical bonds with F atoms decrease greatly on the surface and that a hydrophilic layer is formed due to the plasma graft polymerization process. Using the present surface treatment apparatus, it is possible to bond A4-sized sheets of PTFE and metals without losing the excellent physical properties of PTFE.

Surface modification by nonthermal plasma induced by using magnetic-field-assisted gliding arc discharge

The authors report on the introduction of a magnetic field to gliding arc discharge (GD) in order to enhance surface modification by nonthermal plasma at atmospheric-pressure. The GD is induced between two wire electrodes by using a pulse high-voltage power supply with peak-to-peak voltage of 5 kV. When a magnetic field of 0.25 T is applied, the GD enlarged and a 19-cm-long stretch of plasma is excited. The surface treatment of polyethylene terephthalate and polytetrafluoroethylene films is performed. The adhesion improved by up to ∼30 times due to the enhanced chemical activity in the films.

Microfabrication and Metal Plating Technologies on Polytetrafluoroethylene Film Surface Treated by Atmospheric-Pressure Nonthermal-Plasma Graft Polymerization Process

Microfabrication by photolithography and nickel plating of fluoropolymer film, exposed to atmospheric-pressure nonthermal-plasma (NTP) graft polymerization, are investigated. Electroless nickel plating on the NTP-graft-polymerizationtreated polytetrafluoroethylene (PTFE) film is successfully achieved. Highly adhesive nickel plating is obtained by reverse bend test. Furthermore, photolithographic patterns are formed on the plated PTFE film. This process is expected to be applied to flexible printed substrates and millimeter-wave antenna.

Electroless nickel plating on fluoroplastics films using atmospheric pressure nonthermal plasma graft polymerization process

Electroless nickel plating and photolithography on a fluoroplastics film, which is treated by atmospheric pressure nonthermal plasma graft polymerization, is investigated. Fluoroplastics such as PFA (perfluoroalkoxy fluoroplastics) and PTFE (polytetrafluoroethylene) are extremely stable, inactive, and hydrophobic. Therefore, it is difficult to apply them to electric circuits without surface treatment. In this study, a low-environmental load surface modification of a PTFE film using an atmospheric nonthermal plasma graft polymerization device that can treat A4-size sample is performed. In addition, electroless nickel plating and photolithography on the treated PTFE film are achieved successfully.