Wafer laser processing method and laser processing device

Abstract

The present invention provides a laser machining method and a laser machining apparatus for wafers by which the wafer can be machined by laser while the surface of the wafer to be machined is uniformly covered with a protection film.The laser machining method is used to machine a wafer by laser along a lattice-like streets to divide the wafer into devices wherein a plurality of devices are formed like a matrix on its surface. It includes a protection film covering step to spray a liquid resin on the machining surface of the wafer and cover the protection film, and a laser light irradiation step to give a laser light to the machining surface of the wafer wherein the protection cover is formed, along the streets through the protection film.

Description

technical field [0001] The present invention relates to a laser processing method and a laser processing apparatus for a wafer in which laser processing is performed on the processing surface of a wafer such as a semiconductor wafer or an optical device wafer. Background technique [0002] As is well known to those skilled in the art, in a semiconductor device manufacturing process, a semiconductor wafer is formed in which an insulating film and a functional film are laminated on the surface of a semiconductor substrate such as silicon. A body is used to form a plurality of semiconductor chips such as ICs and LSIs in a matrix. The thus-formed semiconductor wafer is divided by predetermined dicing lines called streets, along which dicing is performed to produce individual semiconductor chips. In addition, the surface of a sapphire substrate or the like is divided into a plurality of regions by forming grid-shaped dividing streets, and gallium nitride-based compound semicondu...

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Problems solved by technology

[0010] However, if Figure 9 As shown in (b), devices D such as circuits are formed on the surface of the wafer W, and it has unevenness. Therefore, even if the rotary table T holding the wafer W is rotated, it is difficult to flow the liquid resin L to the outer periphery under the action of centrifugal force. It is difficult to uniformly coat the surface of the wafer W with liquid resin

In addition, like sapphire, when a plurality of smaller-diameter wafers are arranged in the support member, it is difficult to uniformly coat the surface of the plurality of wafers with a resin protective film when performing the above-mentioned spin coating.

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