Importance

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Abstract

A method and associated structure for excising laminate chip carriers from a panel that has a thickness less than about 100 mils. A laser beam is focused on a surface of the panel, and the panel is moved relative to the laser beam in a geometric pattern, such that cells of the panel (e.g., chip carriers) are excised from the panel. The laser parameters include a wavelength between about 500 nanometers and about 600 nanometers, a pulse width greater than about 100 nanoseconds and less than about 350 nanoseconds, an average power of at least about 1 watt, a pulse repetition rate between about 5,000 pulses/sec and about 20,000 pulses/sec, and a target diameter (D) between about 2 microns and about 30 microns. The kerf width between adjacent excised cells is between about 2 microns and about 75 microns. The width of an excised cell is at least 5 mm. A displacement between successive pulses of the laser beam is less than about 2D. The panel may comprise a layered structure that includes an organic layer and a metal layer. The laser includes, inter alia, a lasant of Nd:YAG, Nd:YLF, Nd:YAP, or Nd:YVO.sub.4. The method of the present invention wastes less panel area by at least a factor of about 13 than does the mechanical excising techniques of the related art.

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First Claim