Using a double-cut for mechanical protection of a wafer-level chip scale package (WLCSP)

摘要

Consistent with an example embodiment, there is a semiconductor device, with an active device having a front-side surface and a backside surface; the semiconductor device of an overall thickness, comprises an active device with circuitry defined on the front-side surface, the front-side surface having an area. The back-side of the active device has recesses f a partial depth of the active device thickness and a width of about the partial depth, the recesses surrounding the active device at vertical edges. There is a protective layer of a thickness on to the backside surface of the active device, the protective material having an area greater than the first area and having a stand-off distance. The vertical edges have the protective layer filling the recesses flush with the vertical edges. A stand-off distance of the protective material is a function of the semiconductor device thickness and the tangent of an angle (θ) of tooling impact upon a vertical face the semiconductor device.

主权项

1. A method for assembling a wafer level chip scale processed (WLCSP) wafer, the wafer having a front-side surface and a back-side surface, a plurality of device die having electrical contacts on the front-side surface, the method comprising:
mounting the wafer onto a grinding foil; back-grinding, to a thickness, the back-side surface the wafer; mounting the wafer onto a sawing foil onto a first-side surface; sawing through second-side surface, the second-side surface opposite the first chosen-side surface, to a depth of the back-ground thickness of the wafer, in areas corresponding to saw lanes of the plurality of device die; stretching the sawing foil so as to space apart device die; on the front-side surface of the wafer, re-mounting the wafer onto molding foil and removing the sawing foil; enveloping the device die in molding compound on the back-side surfaces and vertical faces of the spaced-apart device die, the molding compound of a thickness on the back-side surface and another thickness on the vertical faces; removing the molding foil; re-mounting the molded WLCSP wafer on its back-side surface, onto a sawing foil; and sawing the molded WLCSP wafer on the front-side surface in saw lanes of the plurality of device die so as to separate the molded wafer into individual device die having protective molding thereon.