| 摘要 |
<p>A laser machining apparatus by which via-holes which have very small diameters can be formed at a low cost. The wavelength of a laser beam emitted from a CO2 laser oscillator (60) is shortened by a tellurium crystal (94) to suppress the diffraction of the laser beam and reduce the value of the focusing limit when the laser beam is focused. Thus, the spot diameter of the laser beam is reduced and holes for the via-holes can be formed in an interlayer insulating resin film on a board (10). Since the diameters of the holes are not increased even if the power of the laser beam is increased to form deeper holes, the holes for via-holes having very small diameters can be formed. An apparatus and method for manufacturing a multilayer printed wiring board is also disclosed.</p> |
