Continuoushyphen;wave laser radiation from an argonhyphen;ion laser in the wavelength range 300ndash;330 m1;amp;3.6nm or 350ndash;380 nm, when focused to a spot such that the power density is sim;10 kW/cm2, can be used to etch polyimide (DuPont KaptonTM) films with as little thermal damage as from an excimer laser (308 or 351 nm) provided the laser spot is moved over the surface at speeds at which the transit time over its own diameter is in the order of 1ndash;1000 mgr;s. There is an optimum speed at which the cutting action is a maximum for a given power density per unit area. The fluence (in J/cm2) at which etching occurs is comparable to results obtained with excimer laser pulses but the depth of the material that is removed per joule of incident laser is energy is sim;100hyphen;fold less. In the present process there is no ablation and no acoustic report accompanies it. Only a fraction of the polyimide that is removed from the surface is seen as debris.
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