Adhesive sheet for laser dicing and its manufacturing method
AssigneeNitto Denko Corporation
InventorYuji Okawa
Life of this patent
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Abstract
An adhesive sheet for laser dicing is used for dicing a workpiece into individual chips by light absorption ablation of laser beam and has at least an adhesive layer on one side of a base material which has a surface opposite to the adhesive layer having no convex parts of width (W) of 20 mm or less and height (h) of 1 μm or more, or no concave parts of width (W) of 20 mm or less and depth (d) of 1 μm or more.
Claims16
A method of manufacturing an adhesive sheet, comprising a step of disposing an adhesive layer on one side of a base material, a step of fabricating a laminated sheet by stacking a separator on the adhesive layer, a step of fabricating a rolled laminated sheet by taking up the laminated sheet in roll, and a step of heating the rolled laminated sheet at a temperature of 30 to 60° C. for 12 to 100 hours,
- wherein the resulting adhesive sheet has at least an adhesive layer on one side of a base material,
- wherein the base material has a surface having an arithmetic average height Ra of 0.4-0.9 μm,
- wherein said adhesive sheet is prepared by cutting said adhesive sheet from said rolled laminated sheet,
- wherein the surface of the base material that does not contact the adhesive layer is free from convex parts that have a height (h) of 1 μm or more over a width (W) of 20 mm or less, and concave parts that have a depth (d) of 1 μm or more over a width (W) of 20 mm or less,
- and wherein said separator comprises a surface not contacting with the adhesive layer that has an arithmetic average height Ra of 0.2 to 2 μm.
A method of manufacturing small pieces of an element comprising a step of adhering an adhesive layer of an adhesive sheet for laser dicing to one side of a workpiece, a step of forming a reformed region in the workpiece by emitting laser beam, a step of dicing the workpiece into individual chips by expanding the adhesive sheet for laser dicing, and a step of peeling off the adhesive sheet for laser dicing from the separated workpiece,
- wherein the adhesive sheet for laser dicing has at least an adhesive layer on one side of a base material,
- wherein the base material has a surface having an arithmetic average height Ra of 0.4-0.9 μm,
- wherein said adhesive sheet is prepared by:
- disposing a separator on the adhesive layer to form a laminated sheet;
- taking up the laminated sheet in roll;
- heating the rolled laminated sheet at a temperature of 30 to 60° C. for 12 to 100 hours;
- and said adhesive sheet is cut from said rolled laminated sheet,
- wherein the surface of the base material that does not contact the adhesive layer is free from convex parts that have a height (h) of 1 μm or more over a width (W) of 20 mm or less, and concave parts that have a depth (d) of 1 μm or more over a width (W) of 20 mm or less,
- and wherein said separator comprises a surface not contacting with the adhesive layer that has an arithmetic average height Ra of 0.2 to 2 μm.
Dependencies are inferred from the claim text.