# US 2020/0402831 A1 · Transfer substrate utilizing selectable surface adhesion transfer elements

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2020/0402831 A1
- Document ID: US20200402831A1
- Status: Published application
- Kind: A1
- Application number: 16/449,844
- Filed: 2019-06-24
- Published: 2020-12-24
- Earliest claimed: 2019-06-24
- Assignees: Palo Alto Research Center Incorporated
- Applicants: Palo Alto Research Center Incorporated
- Inventors: Yunda Wang; Sourobh Raychaudhuri; JengPing Lu
- Web page: https://patentgrep.com/patent/US20200402831A1

## CPC

- H10H 20/01: Manufacture or treatment
- H10P 72/74: {using temporarily an auxiliary support}
- B65G 47/90: Devices for picking-up and depositing articles or materials
- H10H 20/857: Interconnections, e.g. lead-frames, bond wires or solder balls
- H10W 90/00: Package configurations
- H10H 20/0364: {of interconnections}
- H10P 72/7414: {the auxiliary support including means facilitating the selective separation of some of a plurality of devices from the auxiliary support}
- H10P 72/7428: {used to support diced chips prior to mounting}
- H10P 72/7432: {used in a transfer process involving transfer directly from an origin substrate to a target substrate without use of an intermediate handle substrate}
- H10W 72/0198: {batch processes}
- H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- B65G: TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS (packaging B65B; handling thin or filamentary materials, e.g. paper sheets or thread, B65H; cranes B66C; portable mobile or lifting or hauling appliances, e.g. hoists, B66D; devices for lifting or lowering goods for loading or unloading purposes, e.g. fork-lift trucks, B66F9/00; emptying bottles, jars, casks, barrels or similar containers, not otherwise provided for, B67C9/00; delivering or transferring liquids B67D; filling or discharging vessels for liquefied, solidified or compressed gases F17C; pipe-line systems for fluids F17D)
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## 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

## Claims

### Claim 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.

### Claim 2 (depends on 1)

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

### Claim 3 (depends on 1)

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.

### Claim 4 (depends on 1)

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

### Claim 5 (depends on 1)

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

### Claim 6 (depends on 1)

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

### Claim 7 (depends on 6)

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

### Claim 8 (depends on 1)

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

### Claim 9 (depends on 1)

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

### Claim 10 (depends on 1)

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

### Claim 11 (depends on 1)

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

### Claim 12 (depends on 1)

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.

### Claim 13 (depends on 1)

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

### Claim 14 (depends on 1)

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

### Claim 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;
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.

### Claim 16 (depends on 15)

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.

### Claim 17 (depends on 15)

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.

### Claim 18 (depends on 15)

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.

### Claim 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;
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.

### Claim 20 (depends on 19)

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.

### Claim 21 (depends on 19)

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.