Micro device arrangement in donor substrate

Patent metadata

Field	Value
Publication number	US-10535546-B2
Application number	US-201715696700-A
Country	US
Kind code	B2
Filing date	Sep 6, 2017
Priority date	Sep 6, 2016
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

This disclosure is related to arranging micro devices in the donor substrate by either patterning or population so that there is no interfering with unwanted pads and the non-interfering area in the donor substrate is maximized. This enables to have transfer the devices to receiver substrate with fewer steps.

First claim

What is claimed is:

1. A method of arranging micro devices on a donor substrate to avoid interference with non-receiving pads on a receiver substrate during transfer of the micro devices from the donor substrate to receiving pads on the receiver substrate, the method comprising:
a) determining interfering areas on the donor substrate by
i) determining areas on the donor substrate that are overlapping non-receiving pads on the receiver substrate during transfer of a first set of micro devices to a first set of receiving pads on the receiver substrate; and
ii) determining areas on the donor substrate that are not overlapping non-receiving pads after offsetting at least one of the donor substrate or the receiver substrate in a direction to align at least a second set of micro devices with a second set of receiving pads on the receiver substrate or another receiver substrate after the transfer of the first set of micro devices to the receiver substrate; and

b) arranging the micro devices in non-interfering areas of the donor substrate other than the determined interfering areas.

2. The method according to claim 1 , wherein offsetting at least one of the donor substrate or the receiver substrate in the direction comprises one of: a horizontal direction or a vertical direction.

3. The method according to claim 1 , wherein determining interfering areas on the donor substrate further comprising the steps of:
a) using the first set of micro devices transferred to the receiver substrate as a reference;
b) drawing lines in parallel with the offsetting direction from the reference micro devices;
c) drawing lines in the offsetting direction from the second set of receiving pads for the second set of micro devices in reference to the first set of receiving pads on the donor substrate;
d) identifying a set of closest lines from the second set of micro devices to the lines of the first set of the micro devices on the donor substrate; and
e) drawing a new line between the closet lines and the micro device lines, wherein the new line has a similar distance from each of the micro device lines and selected lines,
wherein the areas defined by the new line and encompasses the micro device are the non-interfering areas and the other areas are defined as the interfering areas.

4. The method according to claim 1 , wherein the first set of the non-receiving pads comprises a taller structure, and the second set of the non-receiving pads comprises a shorter structure;
wherein the first set of micro devices associated with the taller structure pads have shorter structures; and
wherein, for donor substrates with micro devices with shorter structures, step a) further comprises determining areas on the donor substrate overlapping with non-receiving pads with shorter structures, and designating those areas as non-interfering areas.

5. The method according to claim 1 , wherein the receiver substrate includes a plurality of sub-pixels, and each sub-pixel includes a cluster of pads including a receiving pad and at least one non-receiving pad;
wherein a width of an interfering area is equal to at least a combined width of the non-receiving pads, including any space between the pads.

6. The method according to claim 1 , wherein the micro devices in the non-interfering areas are arranged in arrays, separated by the interfering areas.

7. The method according to claim 1 , wherein the non-interfering areas including arrays of micro devices for transfer to receiving pads on a receiver substrate.

8. The method according to claim 1 , wherein the interfering areas comprising rows or columns of void areas for overlapping non-receiving pads on the receiver substrate to prevent micro devices on the donor substrate from interfering with non-receiving pads during transfer of micro devices to the receiving pads.

9. The method according to claim 1 , wherein the interfering areas comprise longitudinally extending areas of the donor substrate, at least as wide as a receiver pad.

10. The method according to claim 1 , wherein the interfering areas comprise laterally extending areas of the donor substrate, at least as wide as a receiver pad.

11. The method according to claim 1 , wherein the interfering areas comprise diagonally extending areas of the donor substrate, at least as wide as a receiver pad.

Assignees

• Vuereal Inc

Inventors

• Chaji Gholamreza

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

• H10P72/7408

  the auxiliary support including alignment aids · CPC title

• H10P72/50

  for positioning, orientation or alignment · CPC title

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P74/23

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title