Method and apparatus for coating the top of an electrical device
AssigneeMicroelectronics and Computer Technology Corporation
InventorsMary A. Hartnett, Kimberly J. Sherman
Life of this patent
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Abstract
A method and apparatus for dispensing a thin coating of a highly viscous encapsulant liquid on to the top surface of a semiconductor device having been inner lead bonded. The coating is dispensed with a controlled thickness and is substantially planar. A liquid encapsulant having optimum thermal, chemical and mechanical properties is selected for protecting the electrical device and which is suitably controlled in an automated liquid dispensed process. The process is directed to various parameters which are required for achieving the desired quality, reliability, and automatic processing capability.
Claims10
An apparatus for encapsulating the top of an electrical device in a tape comprising,
- a track for movably carrying said tape,
- a preheat station over the track for removing moisture from the device,
- an encapsulation dispensing station downstream from the preheat station, said encapsulation station includes,
- a heater positioned below the track for heating an electrical device placed thereon for reducing the viscosity of applied encapsulant,
- a pressure actuated epoxy dispenser positioned above the heater and above the track and means for moving said dispenser in a continuous line and in a plurality of separated concentric lines for dispensing a liquid epoxy encapsulant onto the top of an electrical device positioned on the heater, and
- a gel station downstream from the encapsulation station for heating and solidifying the dispensed epoxy.
In an apparatus for encapsulating the top of an electrical device having a preheat station for removing moisture from the device, a heater for heating the electrical device for reducing the viscosity of applied encapsulant, and a gel station for heating and solidifying the dispensed encapsulant, the improvement in an encapsulation dispensing station positioned between the preheat station and the gel station for uniformly coating the top of the electrical device, comprising,
- a pressure actuated epoxy dispenser, and means for moving said dispenser relative to the top of the electrical device in a concentric movement from the center to the perimeter of the top for dispensing a liquid epoxy encapsulant in a continuous line forming a plurality of separated concentric lines onto the top of the electrical device.
Dependencies are inferred from the claim text.