Multilayer protective coating for integrated circuits and multichip modules and method of applying same
AssigneeHoneywell International Inc.
InventorsKenneth H. Heffner, Curtis W. Anderson
Life of this patent
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Abstract
Disclosed is a method of forming a multilayer opaque coating on an integrated circuit or multichip module. First, an opaque coating composition is heated to a molten state and the molten opaque coating composition is applied so as to form an opaque coating that overlies active circuitry on the surface of the integrated circuit or multichip module, to prevent optical and radiation based inspection and reverse engineering of the active circuitry. Further coatings are applied over the opaque coating to shield the active circuitry of the integrated circuit or multichip module from the adverse affects of electromagnetic interference and/or high energy radiation.
Claims8
A method of forming a multilayer coating on a semiconductor integrated circuit device comprising the steps of:
- preparing first particles of a first coating composition;
- applying the first particles to a flame stream which is at a temperature sufficient to place the first particles in a molten state;
- building a specific thickness first layer of said first coating composition by passing the flame stream across the integrated circuit in successive passes over the integrated circuit;
- preparing second particles of a second coating composition;
- applying the second particles to a flame stream which is at a temperature sufficient to place the second particles in a molten state;
- building a specific thickness of a said second coating composition on said first layer by passing the flame stream across the integrated circuit in successive passes over the integrated circuit;
- and
- selecting the size of said first and second particles so that the particles attain a molten state in the flame stream and produce an impact force less than a specific level when striking the circuit in a molten state.
Dependencies are inferred from the claim text.