US 6,420,245 B1 · Method for singulating semiconductor wafers

Abstract

A method and apparatus for singulating semiconductor wafers is described. The method comprises the steps of aiming a laser beam at a layer placed over the substrate; absorbing energy from the laser beam into the layer; forming scribe lines in the layer by scanning the laser beam across the layer; and cutting through the substrate along the scribe lines with a saw blade to singulate the wafer. The apparatus includes a laser placed over the coating layer of the substrate, and a saw blade mounted over a surface of the substrate. The coating layer has a first absorption coefficient relative to a wavelength of the laser and the semiconductor substrate has a second absorption coefficient less than the first absorption coefficient. Energy from the laser beam is absorbed into the coating layer to form scribe lines therein, and the saw blade cuts through the substrate along the scribe lines.

Claims31

Dependent claims

A method for dicing a semiconductor substrate comprising the steps of:

(a) aiming a laser beam at a layer placed over a top surface of the substrate, the layer having a first absorption coefficient relative to a wavelength of the laser beam;
(b) absorbing energy from the laser beam into the layer based on the first absorption coefficient;
(c) forming a first set of scribe lines in a first direction in the layer by scanning the laser beam across the layer, the laser beam removing at least a portion of the layer;
(d) forming a second set of scribe lines in a second direction in the layer by scanning the laser beam across the layer and removing at least a portion of the layer with the laser beam, the second direction substantially orthogonal to the first direction;
(e) cutting through the substrate along the second set of scribe lines with a saw blade to form a respective first set of kerfs;
and
(f) cutting through the substrate along the first set of scribe lines with the saw blade to form a respective second set of kerfs,
wherein the substrate has a second absorption coefficient relative to the wavelength of the laser beam, the second absorption coefficient less than the first absorption coefficient by about an order of an order of magnitude.

5 more elements

A method for dicing a semiconductor substrate using a laser and a saw blade, the method comprising the steps of:

(a) aiming the laser at a layer placed over a top surface of the substrate;
(b) absorbing energy from the laser into the layer;
(c) forming a first scribe line in a first direction in the layer by scanning the laser across the layer, the laser removing at least a portion of the layer;
(d) cutting a first kerf in the substrate with the saw blade along the first scribe line;
(e) forming a further first scribe line in the first direction over the substrate, the further scribe line substantially parallel to the first scribe line;
(f) cutting a further first kerf in the substrate with the saw blade along the further first scribe line;
(g) repeating steps (e) and (f) in the first direction until the entire substrate is scribed and cut;
(h) forming a second scribe line in a second direction in the layer by scanning the laser across the layer and removing at least a portion of the layer, the second direction substantially orthogonal to the first direction;
(i) cutting a second kerf in the substrate with the saw blade along the second scribe line;
(j) forming a further second scribe line in the second direction on the substrate, the further second scribe line substantially parallel to the second scribe line;
(k) cutting a further second kerf in the substrate with the saw blade along the further second scribe line;
and
(l) repeating steps (j) and (k) in the second direction until the entire substrate is scribed and cut,
wherein the layer has a first absorption coefficient and the substrate has a second absorption coefficient relative to a wavelength of the laser beam, the first absorption coefficient greater than the second absorption coefficient by about an order of magnitude, and the first kerf, the further first kerfs, the second kerf and the further second kerfs form a plurality of dice from the substrate.

11 more elements

Dependencies are inferred from the claim text.

Method for singulating semiconductor wafers

Life of this patent

Method for singulating semiconductor wafers

Life of this patent

Abstract

Claims31