Electro Scientific Industries, Inc.

Other

Esi-pyrophotonics Lasers, Inc.

Corey M Dunsky

Ho Wai Lo

Hisashi Matsumoto

Xinbing Liu

Bryan C Gundrum

Nicholas J Croglio

Leon A Newman

John T Kennedy

Vernon A Seguin

Tullio Panarello

Richard Murison

Richard S Harris

Matthew Noel Rekow

Spencer Barrett

Donald R Wilt

Ken Whiteman

Raman Sudhakar

A series of laser pulses in a pulse train, each pulse with a predetermined temporal power shape, scribes a line in a thin film of material on a substrate. The predetermined temporal pulse shape has a fast risetime and fast falltime and a pulse length between 10% power points of less than 10 ns. Scribing a line in the thin film is achieved by placing the series of laser pulse spots on the line to be scribed such that there is some overlapping area between adjacent laser pulse spots along the line. The use of a series of laser pulses with the predetermined pulse shape to scribe a line in the thin film results in a better quality and cleaner scribing process compared to that achieved with a conventional pulse shape.

Method and apparatus for scribing a line in a thin film using a series of laser pulses

A diode-pumped, solid-state laser ( ) of a laser system ( ) provides ultraviolet Gaussian output ( ) that is converted by a diffractive optical element ( ) into shaped output ( ) having a uniform irradiance profile. A high percentage of the shaped output ( ) is focused through an aperture of a mask ( ) to provide imaged to provide imaged shaped output ( ). The laser system ( ) 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 ( ) that have better edge, bottom, and taper qualities than those produced by a clipped Gaussian laser system. An alternative laser system ( ) employs a pair of beam diverting galvanometer mirrors ( ) that directs the Gaussian output around a shaped imaging system ( ) that includes a diffractive optical element ( ) and a mask ( ). Laser system ( ) provides a user with the option of using either a Gaussian output or an imaged shaped output ( ).

Beam shaping and projection imaging with solid state UV gaussian beam to form vias

An EOM Q-switched CO laser produces bursts of laser pulses delivered at a high PRF such as 20-140 kHz and having a short high-power spike of about 80-150 ns followed by a lower-power tail of about 0.05-12.0 &mgr;s. The bursts and/or laser pulses can be shaped by controlling the RF pumping duty cycle, the delay between the onset of RF pumping and the initiation of Q-switching, the pulse repetition frequency, and/or the duration of the tail. The bursts of laser pulses can be adapted to facilitate machining of metal layers and/or layers containing materials having disparate vaporization temperatures and/or disparate melting points, such as FR4 or green ceramics.

Micromachining with high-energy, intra-cavity Q-switched CO2  laser pulses

Beam shaping and projection imaging with solid state UV Gaussian beam to form vias

A single pass actuator ( ), such as a deformable mirror ( ), quickly changes, preferably in less than 1 ms, the focus and hence the spot size of ultraviolet or visible wavelength laser pulses to change the fluence of the laser output ( ) at the workpiece surface between at least two different fluence levels to facilitate processing top metallic layers ( ) at higher fluences and underlying dielectric layers ( ) at lower fluences to protect bottom metallic layers ( ). The focus change is accomplished without requiring Z-axis movement of the laser positioning system ( ). In addition, the spot size can be changed advantageously during trepanning operations to decrease via taper, reduce lip formation, increase throughput, and/or minimize damage.

Laser system and method for single press micromachining of multilayer workpieces

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Portland, OR, United States of America

Corey M Dunsky