Photolithography of polytetrafluoroethylene for tailored adhesion

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5131276

Rye, R R; Martinez, R J

Irradiation of polytetrafluoroethylene (PTFE) with Mg(K..cap alpha..) x-rays is shown to protect the surface against the chemical etching steps used to prepare PTFE for adhesion. Pre-irradiated etched samples of PTFE have adhesion strengths using epoxies of less than 3% of that for non-irradiated etched samples. The major portion of this decrease in/sub 3/ adhesion strength occurs for x-rays exposures of less than 10 min (/approximately/4.8 x 10/sup 3/ mrads) and failure in every case occurs in PTFE and not in the bonded transiton region. XPS measurements (20 A sampling depth) show little difference in F content between irradiated and non-irradiated samples, but thermal desorption shows increasing fluorocarbon desorption with irradiation time. These results are consistent with the known radiation chemistry of PTFE. Irradiation produced free radicals lead to branching andor cross-linking, and a surface rich in low molecular weight fluorocarbons. The more rigid cross-linked surface is resistant to deep (10,000 A) chemical attack and the bond formed is with a surface rich in short chain fluorocarbons. Both a thin boundary region and bonding to short chain species is expected to lead to weak adhesive bonding. Electron irradiation results are obtained which are comparable to the x-ray irradiation results. With electrons one has the capability of rastering the electron beam and drawing low adhesion strength patterns with resolution limited by the beam diameter. 5 figs., 8 refs.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5131276
• Report Number(s): SAND-88-0874C; CONF-880408-12; ON: DE88008796
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360605* -- Materials-- Radiation Effects
ADHESION
ADHESIVES
BEAMS
CHEMICAL REACTIONS
DEHALOGENATION
DOSES
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
ETCHING
FLUORINATED ALIPHATIC HYDROCARBONS
HALOGENATED ALIPHATIC HYDROCARBONS
INDUSTRY
IONIZING RADIATIONS
LEPTON BEAMS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC POLYMERS
PARTICLE BEAMS
POLYETHYLENES
POLYMERS
POLYOLEFINS
POLYTETRAFLUOROETHYLENE
PRINTING AND PUBLISHING INDUSTRY
RADIATION DOSES
RADIATION EFFECTS
RADIATIONS
SURFACE FINISHING
X RADIATION