A low-temperature, direct bonding method for poly(methyl methacrylate) (PMMA) plates has been developed by employing surface treatment by atmospheric pressure oxygen plasma, vacuum oxygen plasma, ultraviolet (UV)/ozone or vacuum ultraviolet (VUV)/ozone. Reasonable bonding strength, as evaluated by a tensile test, was achieved below the glass transition temperature (Tg). The highest bonding strength among the achieved results is 1.43 MPa (about three times the value for conventional direct bonding) at an annealing temperature of 50°C and an applied pressure of 2.5 MPa for 10 min. Low-temperature bonding prevents deformation of the PMMA microstructure. A prototype PMMA microchip that has fine channels of 5μm depth was fabricated by hot-embossing using a Si mold. After atmospheric pressure oxygen plasma activation, direct bonding was carried out at an annealing temperature of 75°C and an applied pressure of 3 MPa for 3 min. The method gives good bonding characteristics without deformation and leakage. This low-temperature bonding technology can be applied to polymer micro/nano structures.
|ジャーナル||IEEJ Transactions on Electrical and Electronic Engineering|
|出版ステータス||Published - 2007 5月|
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