Method for forming an electronic device on a flexible substrate supported by a detachable carrier

• US 9,627,420 B2
• Filed: 02/08/2008
• Issued: 04/18/2017
• Est. Priority Date: 02/08/2008
• Status: Active Grant

• Current Assignee: CareStream Health Incorporated
• Original Assignee: CareStream Health Incorporated
• Inventors: Kerr, Roger Stanley, Tredwell, Timothy John
• Primary Examiner(s): Vo, Peter DungBa
• Assistant Examiner(s): Carley, Jeffrey T
• Application Number:
  US12/028,194
• Publication Number:
  US 20090200550A1
• Time in Patent Office: 3,357 Days
• Field of Search: 29830, 29832
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1218 with a particular composition or structure of the substrate
• CPC Class Codes: H01L 27/1266 the substrate on which the devices are formed not being the final device substrate, e.g. using a temporary substrate
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• CPC Class Codes: H05K 1/0353 consisting of two or more materials, e.g. two or more polymers, polymer + filler, + reinforcement
• CPC Class Codes: H05K 1/0366 reinforced, e.g. by fibres, fabrics H05K1/036 takes precedence
• CPC Class Codes: H05K 3/007 Manufacture or processing of a substrate for a printed circuit board supported by a temporary or sacrificial carrier H05K1/187, H05K3/20 and H05K3/4682 take precedence
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A method for forming an electronic device provides a carrier formed from a composite material comprising a plastic binder and an embedded material. A substrate material is attached to the carrier. The substrate is processed to form the electronic device thereon. The substrate is then detached from the carrier to yield the resultant electronic device.

Claims

1. A method for forming an electronic device, the method comprising:

forming a carrier comprising a plastic binder and embedding pieces of a material in the plastic binder;

applying an adhesive coating on the carrier;

attaching a substrate to the carrier using the adhesive coating therebetween;

planarizing a surface of the substrate;

forming the electronic device over the planarized surface of the substrate including depositing and patterning metal, semiconductor and insulator materials on the planarized surface of the substrate; and

detaching the substrate with the electronic device from the carrier.

2. The method of claim 1 wherein attaching comprises laminating by heating the carrier surface, heating the substrate, or both.

3. The method of claim 1 wherein attaching comprises softening a surface of the carrier using a solvent.

4. The method of claim 1 wherein detaching comprises heating the carrier surface, heating the substrate, or both.

5. The method of claim 4 wherein heating causes the plastic binder to undergo a reflow condition.

6. The method of claim 1 wherein detaching comprises softening a surface of the carrier using a solvent.

7. The method of claim 1, wherein the carrier comprises a first layer of embedded material comprising a first plurality of elongated rods oriented substantially in parallel, and a second layer having a second plurality of elongated rods oriented substantially in parallel, and wherein the first plurality of elongated rods is oriented orthogonally to the second plurality of elongated rods.

8. The method of claim 1, wherein the substrate and the embedded material each comprise a same metal.

9. The method of claim 8, wherein the embedded material comprises a stainless steel mesh, the substrate comprises stainless steel foil, and the carrier comprises polytetrafluoroethylene.

10. The method of claim 1, wherein a difference between the coefficient of thermal expansion of the embedded material and of the substrate is within ±

2 ppm/C °

.

13. The method of claim 1, wherein the embedded material comprises fiberglass.

14. The method of claim 1, further comprising forming a carrier having multiple layers, wherein a first plurality of the multiple layers each comprises first embedded fibers selectively aligned in a first direction therein, and wherein a second plurality of the multiple layers each comprises second embedded fibers selectively aligned in a second direction therein.

15. The method of claim 14, wherein the first and second direction are offset by about 90 degrees and are each generally parallel with the planarized surface of the substrate.

16. The method of claim 15, further comprising alternating the layers having the first embedded fibers selectively aligned in the first direction with the layers having the second embedded fibers selectively aligned in the second direction to form the carrier having multiple layers.

20. The method of claim 1, wherein the embedded material is selected from the group consisting of fibers, strands, mesh, interwoven material, a screen, platelets, elongated elements, wires, rods, and ceramic.

21. The method of claim 1, wherein the substrate is made from a substrate material that is either transparent to a preselected bandwidth of electromagnetic waves or is absorbent to the preselected bandwidth of electromagnetic waves, and wherein the carrier is made from a carrier material that is either absorbent to the preselected bandwidth of electromagnetic waves or is transparent to the preselected bandwidth of electromagnetic waves.

11. A method for forming an electronic device, the method comprising:

forming a carrier comprising a binder and embedding pieces of a material in the binder;

treating a surface of the carrier to expose portions of the embedded material above the surface of the carrier;

applying an adhesive on the exposed portions of the embedded material;

adhering a substrate layer only on a portion of the surface of the carrier including on the exposed portions of the embedded material using the adhesive on the exposed portions of the embedded material;

forming the electronic device over the surface of the substrate layer including depositing and patterning metal, semiconductor and insulator materials on the surface of the substrate layer; and

removing the substrate layer with the electronic device from the carrier.

12. The method of claim 11, wherein the plastic binder comprises polytetrafluoroethylene.

17. The method of claim 11, further comprising forming a carrier having multiple layers, wherein a first plurality of the multiple layers each comprises the plastic binder and first embedded fibers selectively aligned in a first direction therein, and wherein a second plurality of the multiple layers each comprises the plastic binder and second embedded fibers selectively aligned in a second direction therein.

18. The method of claim 17, wherein the first and second direction are offset by about 90 degrees and are each generally parallel with the surface of the substrate.

19. The method of claim 17, further comprising alternating the layers having the first embedded fibers selectively aligned in the first direction with layers having the second embedded fibers selectively aligned in the second direction to form the carrier having multiple layers.

22. The method of claim 11, wherein the embedded material comprises a particulate material.

23. The method of claim 11, further comprising leaving a non-contact area between the surface of the carrier and the substrate layer after the step of adhering the substrate layer.

24. The method of claim 23, further comprising applying the adhesive point-by-point on the exposed portions of the embedded material and not applying the adhesive on at least a portion of the surface of the carrier.

25. The method of claim 11, further comprising applying the adhesive to a surface of the substrate facing the surface of the carrier.