Transfer substrate utilizing selectable surface adhesion transfer elements

Patent metadata

Field	Value
Publication number	US-10964582-B2
Application number	US-201916449844-A
Country	US
Kind code	B2
Filing date	Jun 24, 2019
Priority date	Jun 24, 2019
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

An apparatus includes a transfer substrate with two or more transfer elements. Each of the transfer elements includes an adhesion element having a first surface adhesion at a first temperature and a second surface adhesion at a second temperature. The second surface adhesion less than the first surface adhesion. Each transfer element has a thermal element operable to change a temperature of the adhesion element in response to an input. A controller is coupled to provide the inputs to the thermal elements of the two or more transfer elements to cause a subset of the transfer elements to selectably hold objects to and release the objects from the transfer substrate in response to changes between the first and second surface adhesion of the subset of the transfer elements.

First claim

The invention claimed is:

1. An apparatus, comprising:
a transfer substrate, comprising two or more transfer elements, each of the transfer elements comprising:
an adhesion element having a first surface adhesion at a first temperature and a second surface adhesion at a second temperature, the second surface adhesion less than the first surface adhesion; and
a thermal element operable to change a temperature of the adhesion element in response to an input; and

a controller coupled to provide the inputs to the thermal elements of the two or more transfer elements to cause a subset of the transfer elements to selectably hold objects to and release the objects from the transfer substrate in response to changes between the first and second surface adhesion of the subset of the transfer elements, wherein the changes between the first and second surface adhesion are repeatable and reversible.

2. The apparatus of claim 1 , wherein the objects comprise sub-millimeter electronic devices.

3. The apparatus of claim 1 , wherein the two or more transfer elements comprise an array of transfer elements spaced at a pitch between 1 μm and 1 mm.

4. The apparatus of claim 1 , wherein the adhesion element is formed of a multi-polymer that contains stearyl acrylate (SA) polymer.

5. The apparatus of claim 1 , wherein a difference between the first and second temperatures is less than 20° C.

6. The apparatus of claim 1 , wherein the thermal element comprises a heating element.

7. The apparatus of claim 6 , wherein the heating element comprises a resistive heating element.

8. The apparatus of claim 1 , wherein the thermal element comprises a cooling element.

9. The apparatus of claim 1 , wherein the inputs comprise electrical signals.

10. The apparatus of claim 1 , wherein the inputs comprise laser light.

11. The apparatus of claim 1 , wherein the transfer elements further comprise a thermal insulator between the adhesion element and the transfer substrate.

12. The apparatus of claim 1 , wherein the adhesion elements of the two or more transfer elements comprise a continuous layer that covers all of the two or more transfer elements.

13. The apparatus of claim 1 , wherein the adhesion element is tacky at the first temperature and rigid at the second temperature.

14. The apparatus of claim 1 , wherein the transfer elements are implemented on a curved substrate or a roller.

15. A method comprising:
applying first inputs to a subset of a plurality of transfer elements on a transfer substrate, each of the plurality of transfer elements having a thermal element and an adhesion element thermally coupled to the adhesion element, the first inputs causing each transfer element in the subset of transfer elements to achieve a first temperature such that each adhesion element of each transfer element in the subset achieves a first surface adhesion, wherein other transfer elements not in the subset are at a second temperature that causes each adhesion element of the other transfer elements to achieve a second surface adhesion less than the first surface adhesion, wherein changing between the first and second surface adhesion is repeatable and reversible;
causing at least the subset of the transfer elements to contact a respective subset of objects of a plurality of objects on a donor substrate;
moving the transfer substrate away from the donor substrate, the subset of objects adhering to the subset of transfer elements at the first surface adhesion and moving with the transfer substrate;
causing the subset of objects on the transfer substrate to contact a target substrate; and
transferring the subset of objects from the transfer substrate to the target substrate.

16. The method of claim 15 , wherein causing at least the subset of the transfer elements to contact the respective subset of objects comprises causing all of the plurality of transfer elements to contact all of the respective plurality of objects on the donor substrate, and wherein other objects contacted by the other transfer elements do not adhere to the transfer substrate and do not move with the transfer substrate.

17. The method of claim 15 , wherein transferring the subset of objects from the transfer substrate to the target substrate comprises causing the subset of transfer elements to achieve a second temperature such that the adhesion element of each transfer element in the subset achieves the second surface adhesion.

18. The method of claim 15 , wherein the target substrate applies a counter force that facilitates transferring the subset of objects from the transfer substrate to the target substrate.

19. A method comprising:
causing a plurality of transfer elements to contact a corresponding plurality of objects on a donor substrate, each of the transfer elements comprising: an adhesion element having a first surface adhesion at a first temperature and a second surface adhesion at a second temperature, the second surface adhesion less than the first surface adhesion; and a thermal element operable to change a temperature of the adhesion element to repeatably and reversibly change between the first and second surface adhesions;
applying first inputs to the thermal elements of a subset of a plurality of the transfer elements causing the adhesion element of each transfer element in the subset of transfer elements to achieve the first surface adhesion, wherein the adhesion element of other transfer elements not in the subset are the second surface adhesion;
moving the transfer substrate away from the donor substrate such that a corresponding subset of objects adhere to the subset of transfer elements and move with the transfer substrate;
causing the subset of objects on the transfer substrate to contact a target substrate; and
transferring the subset of objects from the transfer substrate to the target substrate.

20. The method of claim 19 , wherein transferring the subset of objects from the transfer substrate to the target substrate comprises causing the subset of transfer elements to achieve the second surface adhesion.

21. The method of claim 19 , wherein the target substrate applies a counter force that facilitates transferring the subset of objects from the transfer substrate to the target substrate.

Assignees

• Palo Alto Res Ct Inc

Inventors

• Wang Yunda
• Raychaudhuri Sourobh
• Lu Jengping

Classifications

• H10P72/7432

  used in a transfer process involving transfer directly from an origin substrate to a target substrate without use of an intermediate handle substrate · CPC title

• H10P72/7428

  used to support diced chips prior to mounting · CPC title

• H10P72/7414

  the auxiliary support including means facilitating the selective separation of some of a plurality of devices from the auxiliary support · CPC title

• H10W90/00

  Package configurations · CPC title

• H10W72/0198

  batch processes · CPC title