Apparatus and method for decapsulating packaged integrated circuits

• US 9,059,184 B2
• Filed: 12/19/2011
• Issued: 06/16/2015
• Est. Priority Date: 12/19/2011
• Status: Active Grant

• Current Assignee: RKD Engineering Corporation Incorporated (RKD Premium Products Incorporated)
• Original Assignee: RKD Engineering Corporation Incorporated (RKD Premium Products Incorporated)
• Inventors: Martin, Kirk Alan
• Primary Examiner(s): Ahmed, Shamim
• Assistant Examiner(s): GATES, BRADFORD M
• Application Number:
  US13/329,735
• Publication Number:
  US 20130157471A1
• Time in Patent Office: 1,275 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01L 21/32134 by liquid etching only
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 21/67126 Apparatus for sealing, encapsulating, glassing, decapsulating or the like processes H01L23/02, H01L23/28
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A method and system for decapsulating a portion of an encapsulated integrated circuit delivers etchant mixture in variable but precise, high-velocity micro-metered pulses to a single outlet port of a pump from any one of or a combination of separate inlet ports connected to separate etchant source containers holding specific etchant solutions, controls temperature of the etchant mixture by passing the etchant mixture from the outlet port through a serpentine passage in a temperature-controlled metal block, and delivers the etchant mixture from the serpentine passage of the temperature-controlled block via a delivery conduit to an encapsulation surface of the encapsulated integrated circuit.

Claims

1. A method for decapsulating a portion of an encapsulated integrated circuit including copper elements, comprising the steps of:

(a) delivering etchant mixture in variable but precise, pressurized micro-metered pulses to a single outlet port of a pump from any one of or a combination of separate inlet ports connected to separate etchant source containers holding specific etchant solutions;

(b) controlling temperature of the etchant mixture at or below ambient temperature by passing the etchant mixture from the outlet port through a serpentine passage in a temperature-controlled metal block; and

(c) delivering etchant mixture from the serpentine passage of the temperature-controlled block via a delivery conduit to an encapsulation surface of the encapsulated integrated circuit, wherein the etchant mixture is controlled at or below ambient temperature thereby minimizing damage to the copper elements.

2. The method of claim 1 further comprising a step for removing used etchant mixture via one or more spent-etchant passages proceeding from the encapsulation surface where the etchant mixture is delivered, the spent-etchant passages conducting etchant mixture and products of etching away from the encapsulation surface.

3. The method of claim 2 further comprising a step for delivering the spent etchant to at least one waste etchant container through a heat exchanger enabled to return the spent etchant to ambient temperature.

4. The method of claim 1 further comprising supporting the encapsulated integrated circuit on an etch head in an etch plate in a manner to expose the encapsulation surface to the etchant delivered by the delivery conduit, providing a safety cover sealable to the etch plate forming an etchant chamber, and holding the encapsulated integrated circuit to the etch head by a vertically-translatable ram.

5. The method of claim 4 comprising a step providing the etch head as an insert to the etch plate, such that different specific etch heads may be used to provide for exposure of different areas of encapsulation on different encapsulated integrated circuits.

6. The method of claim 4 wherein the vertically-translatable ram is driven by gas pressure provided by electrically operated valves controlled from the control station.

7. The method of claim 1 wherein the pump is a diaphragm pump driven by pressurized gas from a reservoir and controlled from the control station.

8. The method of claim 1 comprising steps for using nitric acid and sulphuric acid in a ratio and at the temperature controlled to below ambient temperature to minimize damage to the copper elements of the integrated circuit.