Patent•
Beam shaping and projection imaging with solid state uv gaussian beam to form vias
26 May 2000-
TL;DR: In this article, a diode-pumped solid-state laser (52) of a laser system (50) provides ultraviolet Gaussian output (54) that is converted by a diffractive optical element (90) into shaped output (94) having a uniform irradiance profile.
Abstract: A diode-pumped, solid-state laser (52) of a laser system (50) provides ultraviolet Gaussian output (54) that is converted by a diffractive optical element (90) into shaped output (94) having a uniform irradiance profile. A high percentage of the shaped output (94) is focused through an aperture of a mask (98) to provide imaged shaped output (118). The laser system (50) facilitates a method for increasing the throughput of a via drilling process over that available with an analogous clipped Gaussian laser system. This method is particularly advantageous for drilling blind vias (20b) that have better edge, bottom, and taper qualities than those produced by a clipped Gaussian laser system. An alternative laser system (150) employs a pair of beam diverting galvanometer mirrors (152, 154) that directs the Gaussian output around a shaped imaging system (70) that includes a diffractive optical element (90) and a mask (98). Laser system (150) provides a user with the option of using either a Gaussian output or an imaged shaped output (118).
Citations
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Patent•
18 May 2007TL;DR: In this article, the authors present a Verfahren umfasst: Bestimmen einer minimalenLaserabschmelzschwelle fur jede der Vielzahl von Schichten; Auswahlen; Erzeugen; Strahls von einem oder mehreren Laserimpulsen with einer Fluenz; and ungefahr zehnmal der ausgewahlten Laserabschnelle;
Abstract: Verfahren
zum Schneiden einer Vielzahl von Schichten, die uber einem
Substrat ausgebildet sind, wobei jede der Vielzahl von Schichten
eine jeweilige Laserabschmelzschwelle aufweist, die mit der Laserimpulsbreite
variiert, wobei das Verfahren umfasst: Bestimmen einer minimalen
Laserabschmelzschwelle fur jede der Vielzahl von Schichten; Auswahlen
der hochsten der minimalen Laserabschmelzschwellen; Erzeugen
eines Strahls von einem oder mehreren Laserimpulsen mit einer Fluenz
in einem Bereich zwischen der ausgewahlten Laserabschmelzschwelle
und ungefahr zehnmal der ausgewahlten Laserabschmelzschwelle;
und Ritzen eines Einschnitts zwischen einer Vielzahl von integrierten
Schaltungen, die in der Vielzahl von Schichten ausgebildet sind,
wobei der Einschnitt durch die Vielzahl von Schichten zu einer oberen
Oberflache des Substrats verlauft.
References
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TL;DR: In this paper, the authors introduce phase filters having a predetermined phase function into optical coherent systems in such a manner that the local phase variations influence light from local object areas, where the object distribution is multiplied by the phase function so that its spectrum at the frequency plane constitutes the desired transformation.
Abstract: Geometrical image modifications such as coordinate transformations and local translation, inversion, reflection, stretching which require space-variant optical coherent systems are provided by introducing phase filters having a predetermined phase function into optical coherent systems in such a manner that the local phase variations influence light from local object areas. In one embodiment, the object distribution is multiplied by the phase function so that its spectrum at the frequency plane constitutes the desired transformation. In a second embodiment, the aforementioned concept is applied to produce a transformation in an image plane. The phase filters, in a preferred embodiment, comprise computer generated holograms.
311 citations
Patent•
06 Jul 1995TL;DR: In this paper, the output of a continuously pumped, Q-switched, Nd:YAG laser (10) is frequency converted to provide ultraviolet light for forming vias (72, 74) in multi-layered targets (40).
Abstract: The output of a continuously pumped, Q-switched, Nd:YAG laser (10) is frequency converted to provide ultraviolet light (62) for forming vias (72, 74) in multi-layered targets (40). The parameters of the output pulses (62) are selected to facilitate substantially clean, simultaneous or sequential drilling or via formation in a wide variety of materials such as metals, organic dielectrics, and reinforcement materials having different thermal absorption characteristics in response to ultraviolet light. These parameters typically include at least two of the following criteria: high average power of greater than about 100 milliwatts measured over the beam spot area, a temporal pulse width shorter than about 100 nanoseconds, a spot diameter of less than about 50 microns, and a repetition rate of greater than about one kilohertz. The laser system (10) and method circumvent conventional depth of cut saturation limitations and can achieve an increased depth of cut per pulse in a target (40) formed of either single- or multi-layered material.
258 citations
Patent•
17 May 1996TL;DR: In this article, the output of a continuously pumped, Q-switched, Nd:YAG laser is converted to provide ultraviolet light for forming vias in targets (40) having metallic layers (64,68) and a dielectric layer (66).
Abstract: The output of a continuously pumped, Q-switched, Nd:YAG laser (10) is frequency converted to provide ultraviolet light (62) for forming vias (72, 74) in targets (40) having metallic layers (64,68) and a dielectric layer (66) The invention employs a first laser output of high power density to ablate the metallic layer and a second laser output of a lower power density to ablate the dielectric layer The parameters of the output pulses (62) are selected to facilitate substantially clean, sequential drilling or via formation These parameters typically include at least two of the following criteria: power density first above and then below the ablation threshold of the conductor, wavelength less than 400 nm, a temporal pulse width shorter than about 100 nanoseconds, and a repetition rate of greater than about one kilohertz The ability to generate ultraviolet light output pulses at two power densities facilitates the formation of depthwise self-limiting blind vias in multilayer targets, such as a target composed of a layer dielectric material covered on either surface by a layer of metal
154 citations
Patent•
17 Nov 1981
TL;DR: An optical beam homogenizer divides and redirects an incident beam to provide uniform irradiation to a plane surface as mentioned in this paper, which is useful for metal hardening, semiconductor annealing, or other materials processing applications.
Abstract: An optical beam homogenizer divides and redirects an incident beam to provide uniform irradiation to a plane surface. The beam homogenizer is particularly useful in an apparatus and method for uniform laser irradiation of materials. The apparatus comprises a laser, a beam homogenizer, and a support for the material being irradiated. Depending on the system parameters, the apparatus is useful for metal hardening, semiconductor annealing, or other materials processing applications.
152 citations
TL;DR: A versatile, rapidly convergent, iterative algorithm is presented for the construction of kinoform phase plates for tailoring the far-field intensity distribution of laser beams that contains more than 95% of the incident energy inside a desired region and is relatively insensitive to beam aberrations.
Abstract: A versatile, rapidly convergent, iterative algorithm is presented for the construction of kinoform phase plates for tailoring the far-field intensity distribution of laser beams The method consists of repeated Fourier transforming between the near-field and the far-field planes with constraints imposed in each plane For application to inertial confinement fusion, the converged far-field pattern contains more than 95% of the incident energy inside a desired region and is relatively insensitive to beam aberrations
141 citations