Liquid crystal display devices having fill holes and electrical contacts on the back side of the die
AssigneeIntel Corporation
InventorPaul Winer
Life of this patent
Estimating the term…
Abstract
A method of fabricating LCOS devices and testing them at the wafer-scale to identify known-bad dice, to facilitate completing fabrication of only known-good dice. A wafer-scale transparent electrode glass is temporarily placed over the wafer, and liquid crystal material is injected into the LCOS device cavities through fill holes extending through the wafer. After removing the glass and separating the wafer into dice, only the good dice have their die-scale glass attached, liquid crystal material re-injected, solder bumps affixed, and substrate attached.
Claims26
A liquid crystal on semiconductor device comprising:
- a semiconductor die having a first side and a second side;
- a transparent electrode overlying the first side of the semiconductor die defining a cavity between the transparent electrode and the semiconductor die;
- a display pixel array in the cavity;
- and
- a hole extending through the semiconductor die from the second side to the first side into the cavity.
A semiconductor wafer comprising:
- a plurality of LCOS devices formed on a first side of the semiconductor wafer and each having,
- a display pixel array,
- at least one external electrode,
- at least one electrical via extending from a second side of the semiconductor wafer to a respective external electrode, and
- at least one fill hole extending through the semiconductor wafer.
A method of manufacturing a plurality of LCOS devices from one semiconductor wafer, the method comprising:
- fabricating a plurality of display pixel elements on a first side of the semiconductor wafer;
- fabricating at least one external electrode on each of the display pixel elements;
- forming a plurality of first holes through the semiconductor wafer and into contact with respective ones of the at least one external electrode;
- forming a plurality of second holes through the semiconductor wafer;
- and
- fabricating a plurality of electrical conductors each disposed in a respective one of the at least one first holes and in electrical contact with the respective external electrode.
A method of testing a wafer including LCOS devices, the method comprising:
- placing a transparent electrode overlying a plurality of the LCOS devices to define over each a cavity encompassing a pixel element;
- injecting liquid crystal material into the cavities through respective holes which extend through the wafer;
- and
- electrically activating the pixel elements in the cavities.
An LCOS chip comprising:
- a semiconductor die having a front side and a back side;
- a display pixel array overlying the front side of the semiconductor die;
- a transparent electrode layer overlying the display pixel array;
- a seal coupled to the front side of the semiconductor die and to the transparent electrode layer to enclose a cavity containing the display pixel array;
- and
- a fill hole extending from the back side of the semiconductor die into the cavity.
Dependencies are inferred from the claim text.