Systems and methods for separating components of a multilayer stack of electronic components

Patent metadata

Field	Value
Publication number	US-9458550-B2
Application number	US-201414263027-A
Country	US
Kind code	B2
Filing date	Apr 28, 2014
Priority date	Feb 26, 2013
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

Systems and methods for separating components of a multilayer stack of electronic components are disclosed herein. The multilayer stack may include an electronic assembly, a substrate, and a sacrificial anode portion that is located between the electronic assembly and the substrate and that operatively attaches the electronic assembly to the substrate. The methods may include locating the multilayer stack within an electrically conductive fluid to form an electrochemical cell and generating a potential difference between a cathode portion of the electronic assembly and the sacrificial anode portion. The methods further may include separating the electronic assembly from the substrate by electrochemically oxidizing the sacrificial anode portion to dissolve the sacrificial anode portion within the electrically conductive solution.

First claim

The invention claimed is:

1. A multilayer stack of electronic materials, comprising:
a substrate;
an electronic assembly, wherein the electronic assembly includes a sacrificial photovoltaic cell; and
a sacrificial anode portion, wherein the sacrificial anode portion is located between the electronic assembly and the substrate and operatively attaches the electronic assembly to the substrate, wherein the sacrificial anode portion is configured to be dissolved via electrochemical oxidation to permit separation of the electronic assembly from the substrate, and further wherein the sacrificial photovoltaic cell is in electrical communication with the sacrificial anode portion and is configured to apply an electric potential to the sacrificial anode portion to power dissolution of the sacrificial anode portion.

2. The multilayer stack of claim 1 , wherein the electronic assembly further includes a cathode portion that is in electrical communication with the sacrificial photovoltaic cell, wherein the sacrificial photovoltaic cell is configured to generate a potential difference between the cathode portion and the sacrificial anode portion to power the dissolution of the sacrificial anode portion.

3. The multilayer stack of claim 2 , wherein the sacrificial photovoltaic cell is configured to receive electromagnetic radiation and to generate the potential difference between the cathode portion and the sacrificial anode portion responsive to receipt of the electromagnetic radiation, and further wherein a magnitude of the potential difference between the cathode portion and the sacrificial anode portion is at least 0.1 Volts (V) and less than 5 V.

4. The multilayer stack of claim 1 , wherein the electronic assembly includes a device portion that includes at least one of a device layer, a semiconductor device, a III-V semiconductor device, a photovoltaic cell, an inverted photovoltaic cell, and an inverted metamorphic solar cell.

5. The multilayer stack of claim 4 , wherein the electronic assembly further includes a sacrificial photovoltaic cell, wherein the sacrificial photovoltaic cell is located between the substrate and the device portion.

6. The multilayer stack of claim 5 , wherein the electronic assembly further includes an etch stop portion that is located between the sacrificial photovoltaic cell and the device portion and that operatively attaches the sacrificial photovoltaic cell to the device portion.

7. The multilayer stack of claim 1 , wherein the sacrificial anode portion is an epitaxially grown sacrificial anode portion.

8. The multilayer stack of claim 1 , wherein the electronic assembly further includes a cathode portion, wherein the sacrificial anode portion is configured to dissolve responsive to a potential difference between the sacrificial anode portion and the cathode portion being greater than a threshold potential difference.

9. An electrochemical cell, comprising:
an electrically conductive fluid; and
the multilayer stack of claim 8 , wherein the multilayer stack is located within the electrically conductive fluid.

10. The electrochemical cell of claim 9 , wherein a fraction of the sacrificial anode portion is electrochemically oxidized and dissolved within the electrically conductive fluid.

11. The electrochemical cell of claim 9 in combination with a power source that is in electrical communication with the cathode portion and with the sacrificial anode portion and is configured to generate the potential difference between the cathode portion and the sacrificial anode portion.

12. The electrochemical cell of claim 11 , wherein the power source is an internal power source that forms a portion of the multilayer stack.

13. The electrochemical cell of claim 11 , wherein the power source is an external power source that is external to the multilayer stack.

14. A method of separating an electronic assembly from a multilayer stack of electronic components that includes the electronic assembly, a substrate, a cathode portion, and a sacrificial anode portion that is located between the electronic assembly and the substrate and that operatively attaches the electronic assembly to the substrate, the method comprising:
locating the multilayer stack within an electrically conductive fluid to form an electrochemical cell;
generating a potential difference between the cathode portion and the sacrificial anode portion; and
separating the electronic assembly from the substrate by electrochemically oxidizing the sacrificial anode portion to dissolve the sacrificial anode portion within the electrically conductive fluid.

15. The method of claim 14 , wherein the electronic assembly further includes a sacrificial photovoltaic cell that is located between and in electrical and mechanical communication with the cathode portion and the sacrificial anode portion, and further wherein the generating includes:
generating the potential difference with the sacrificial photovoltaic cell.

16. The method of claim 15 , further comprising:
directing electromagnetic radiation onto the sacrificial photovoltaic cell to initiate the generating.

17. The method of claim 14 , further comprising:
establishing a first electrical connection between the cathode portion and a positive terminal of an external power source; and
establishing a second electrical connection between the sacrificial anode portion and a negative terminal of the external power source, wherein the generating includes generating the potential difference between the cathode portion and the sacrificial anode portion with the external power source.

18. The method of claim 14 , further comprising at least one of:
(i) separating the electronic assembly from the substrate without etching the sacrificial anode portion; and
(ii) separating the electronic assembly from the substrate without mechanically peeling the electronic assembly from the substrate.

19. The method of claim 14 , wherein the electronic assembly includes a plurality of electronic devices and the method further comprises:
singulating the plurality of electronic devices concurrently with the separating.

20. A multilayer stack of electronic materials, comprising:
a substrate;
an electronic assembly, wherein the electronic assembly includes:
(i) a device portion that includes at least one of a device layer, a semiconductor device, a III-V semiconductor device, a photovoltaic cell, an inverted photovoltaic cell, and an inverted metamorphic solar cell; and
(ii) a sacrificial photovoltaic cell, wherein the sacrificial photovoltaic cell is located between the substrate and the device portion; and
a sacrificial anode portion, wherein the sacrificial anode portion is located between the electronic assembly and the substrate and operatively attaches the electronic assembly to the substrate, and further wherein the sacrificial anode portion is configured to be dissolved via electrochemical oxidation to permit separation of the electronic assembly from the substrate.

21. A multilayer stack of electronic materials, comprising:
a substrate;
an electronic assembly; and
a sacrificial anode portion, wherein the sacrificial anode portion is located between the electronic assembly and the substrate and operatively attaches the electronic assembly to the substrate, wherein the sacrificial anode portion is configured to be dissolved via electrochemical oxidation to permit separation of the electronic assembly from the substrate, and further wherein the sacrificial anode portion is an epita

Assignees

• Boeing Co

Inventors

• Woo Robyn L
• Zhang Xiaobo
• Fetzer Christopher M
• Rehder Eric M

Classifications

• H10P95/112

  leaving a reusable substrate, e.g. epitaxial lift off · CPC title

• H10P95/11

  Separation of active layers from substrates · CPC title

• H10D84/01

  Manufacture or treatment · CPC title

• H10F71/139

  using temporary substrates · CPC title

• H10F10/1425

  Inverted metamorphic multi-junction [IMM] photovoltaic cells · CPC title