Microdevice arrangement in a donor substrate

Abstract

The present invention relates to the arrangement of microdevices in a donor substrate by patterning or filling, such that non-receiving pads are not disturbed and the non-disturbed area in the donor substrate is maximized. This enables the transfer of microdevices to a receiving substrate in fewer steps.

Description

[0001] Information related to divisional application

[0002] This case is a divisional application. The parent application of this divisional application is the invention patent application filed on October 3, 2017, with application number 201780054107.6 and invention title "Arrangement of Microdevices in an Agent Substrate".

[0003] Cross-reference of related applications

[0004] This application claims priority and rights to U.S. Provisional Patent Application No. 62 / 403,741, filed October 4, 2016; U.S. Provisional Patent Application No. 62 / 426,353, filed November 25, 2016; U.S. Provisional Patent Application No. 62 / 473,671, filed March 20, 2017; U.S. Provisional Patent Application No. 62 / 482,899, filed April 7, 2017; and U.S. Provisional Patent Application No. 62 / 515,185, filed June 5, 2017, the entire contents of which are hereby incorporated herein by reference. Technical Field

[0005] The present invention relates to a system for transferring microdevices onto a receiving substrate, and more particularly to patterning microdevices on a donor substrate and landing regions on the receiving substrate to improve the efficiency of the transfer process. Background Technology

[0006] Several different selective transfer processes have been developed for microdevices. However, if the receiving substrate needs to serve as part of different microdevices on different donor substrates, additional devices on other donor substrates may interfere with the placement (pads) of other types of microdevices assigned to the receiving substrate.

[0007] The object of this invention is to overcome the disadvantages of the prior art by providing specific patterning of devices on a donor substrate to avoid interference with pads on a receiver substrate designated for other microdevices. Other inventions include: pre-processing devices on a donor substrate (cassette substrate); fabricating landing areas (or pads) on the receiver substrate; transferring microdevices from the donor substrate to the receiver substrate; and post-processing to achieve device functionality. The pre-processing step may include patterning and adding bonding elements. The transfer process may involve bonding a pre-selected array of microdevices to the receiver substrate, followed by removal of the donor substrate. Summary of the Invention

[0008] Therefore, the present invention relates to a method for filling a receiving substrate, comprising:

[0009] a) Provides a receiving substrate comprising a plurality of pixels, each pixel comprising a first pad for receiving a first type of microdevice and a second pad for receiving a second type of microdevice;

[0010] b) Provide a first donor substrate comprising a plurality of microdevices of the first type, the plurality of microdevices of the first type being arranged in an array separated by a first interference region gap of the first type of microdevices;

[0011] c) Align the first group of the first type of microdevices on the first donor substrate with the first group of the first pads on the receiving substrate, thereby overlapping the first interference region of the first donor substrate with the second pad to prevent the first type of microdevices from interfering with the second pad.

[0012] d) Transferring the first group of the first type of microdevices from the first donor substrate to the first group of the first pads on the receiving substrate;

[0013] e) Adjust the relative position of the first donor substrate and the receiving substrate so that the second group of the first type of microdevices is aligned with the second group of the first pads on the receiving substrate, thereby overlapping the first interference region of the first donor substrate with the second pad to prevent the first type of microdevices from interfering with the second pad; and

[0014] f) Transfer the second group of the first type of microdevice from the first donor substrate to the second group of the first pad of the receiving substrate.

[0015] Another aspect of the present invention relates to an donor substrate comprising:

[0016] An interference-free region comprising an array of microdevices for transfer to a receiving pad on a receiving substrate; and

[0017] Interference regions include a number of rows or columns of gaps that overlap with non-receiving pads on the receiving substrate to prevent microdevices on the donor substrate from interfering with the non-receiving pads during transfer of the microdevices to the receiving pads.

[0018] Another feature of the present invention provides a method for arranging a microdevice on an donor substrate to avoid interference with a non-receiving pad on a receiving substrate during the transfer of the microdevice from the donor substrate to a receiving pad on a receiving substrate, comprising:

[0019] a) Determine the interference region on the donor substrate through the following steps.

[0020] i) Determine the region on the donor substrate that overlaps with a non-receiving pad on the receiving substrate during the transfer of the first microdevice to a first receiving pad on the receiving substrate; and

[0021] ii) Determine the region on the donor substrate that will not overlap with a non-receiver pad after at least one of the donor substrate or the receiver substrate is offset relative to the other so that at least the second microdevice is aligned with a second receiver pad on the receiver substrate or the other receiver substrate after the first microdevice has been transferred to the receiver substrate; and

[0022] b) Arrange the microdevices on the donor substrate in an interference-free region other than the interference region.

[0023] Another aspect of the present invention relates to a method of filling a receiving substrate, comprising:

[0024] a) Provides a receiving substrate comprising a plurality of pixels, each pixel comprising a first pad for receiving a first type of microdevice and a second pad for receiving a second type of microdevice;

[0025] b) Provide a first donor substrate comprising a plurality of first-type microdevices arranged in an array and a plurality of second-type microdevices arranged in an array, the array of the plurality of second-type microdevices being interleaved with the array of first-type microdevices separated by a first interference region gap of the first-type or second-type microdevices;

[0026] c) Align the first group of the first type of microdevices and the first group of the second type of microdevices on the first applicant substrate with the first group of the first pads and the second pads on the receiving substrate, respectively, so that the first interference area of ​​the first applicant substrate overlaps with the area caused by the spacing difference between the pads and the pixels.

[0027] d) Transferring the first group of first type and second type microdevices from the first donor substrate to the first group of first pads and second pads of the receiving substrate;

[0028] e) Adjust the relative position of the first donor substrate and the receiving substrate so that the second group of first and second type microdevices are aligned with the second group of first and second pads on the receiving substrate, thereby overlapping the first interference region of the first donor substrate with the region caused by the spacing difference between the pads and the pixels; and

[0029] f) Transferring the second group of first and second type microdevices from the first donor substrate to the second group of first and second pads of the receiving substrate. Attached Figure Description

[0030] The invention will be described in more detail with reference to the accompanying drawings, which illustrate preferred embodiments of the invention, wherein:

[0031] Figure 1 An example of a microdevice arrangement in a donor substrate is illustrated.

[0032] Figure 2 An example of a receiving substrate pixel with three different sub-pixels is shown.

[0033] Figure 3A An embodiment is illustrated based on a donor substrate where the receiving substrate is arranged as an interference region and an interference-free region.

[0034] Figure 3B Another embodiment of the donor substrate is illustrated, based on the receiving substrate being arranged into interference regions and non-interference regions.

[0035] Figure 4 An embodiment is illustrated that uses a raised pad associated with one of the microdevices to improve the interference-free area.

[0036] Figure 5 An example of a cluster pad used to improve a non-disruptive area is illustrated.

[0037] Figure 6A An embodiment of an donor substrate is illustrated, having an interference-free region associated with the pads at the edges of the cluster pads.

[0038] Figure 6B An example of an donor substrate with an interference-free region associated with the internal pads of the cluster is illustrated.

[0039] Figure 7A Examples of donor substrates and receiver substrates with clustered pads are illustrated.

[0040] Figure 7B Another example of an donor substrate and a receiver substrate with clustered pads is illustrated.

[0041] Figure 8 An example of a receiving substrate with pads in pixels arranged in two directions is illustrated.

[0042] Figure 9A An embodiment of an donor substrate is illustrated, having an interference-free region associated with one of the pads in the pixel.

[0043] Figure 9B Another embodiment of an donor substrate is illustrated, having an interference-free region associated with one of the pads in the pixel.

[0044] Figure 9C Another embodiment of an donor substrate is illustrated, having an interference-free region associated with one of the pads in the pixel.

[0045] Figure 9DAnother embodiment of an donor substrate is illustrated, having an interference-free region associated with one of the pads in the pixel.

[0046] Figure 10 An embodiment of a clustered pad with an interference-free area for improving pixel pads arranged in two directions is illustrated.

[0047] Figure 11A An embodiment of an donor substrate is illustrated, having an interference-free region associated with one of the pads in the cluster.

[0048] Figure 11B Another embodiment of an donor substrate is illustrated, having an interference-free region associated with one of the pads in the cluster.

[0049] Figure 11C Another embodiment of an donor substrate is illustrated, having an interference-free region associated with one of the pads in the cluster.

[0050] Figure 12A Examples of donor substrates and receiving substrates having clustered pads arranged in two directions are illustrated.

[0051] Figure 12B Examples of donor substrates and receiving substrates having clustered pads arranged in two directions are illustrated.

[0052] Figure 12C Examples of donor substrates and receiving substrates having clustered pads arranged in two directions are illustrated.

[0053] Figure 12D Examples of donor substrates and receiving substrates having clustered pads arranged in two directions are illustrated.

[0054] Figure 13A An embodiment of a receiving substrate is illustrated, comprising a cluster of pads in a receiving substrate and an applicant substrate having an interference-free region associated with one of the pads in the cluster.

[0055] Figure 13B Another embodiment of an donor substrate is illustrated, having an interference-free region associated with one of the pads in the cluster.

[0056] Figure 14A Examples of donor substrates and receiving substrates having clustered pads arranged in two directions are illustrated.

[0057] Figure 14B Examples of donor substrates and receiving substrates having clustered pads arranged in two directions are illustrated.

[0058] Figure 15A Examples of donor (cassette) substrates with different types of microdevices are illustrated.

[0059] Figure 15B This is a flowchart of the process of the present invention.

[0060] Figure 15C This is a flowchart of the microdevice installation process of the present invention.

[0061] Figure 16 Examples of donor (cassette) substrates with different types of microdevices are illustrated.

[0062] Figure 17 Examples of donor substrates used for the same type of microdevices but with different spacing between several groups of microdevices are illustrated.

[0063] Figure 18 An example of a donor substrate with non-uniformity in the output across a microdevice block is illustrated.

[0064] Figure 19 An example of a receiving substrate with non-uniformity of output across multiple microdevice blocks is illustrated.

[0065] Figure 20 An example of a receiving substrate with a skewed microdevice block is illustrated.

[0066] Figure 21 An example of a receiving substrate with a flip microdevice block is illustrated.

[0067] Figure 22 An example of a receiving substrate with flipped and alternating microdevice blocks is illustrated.

[0068] Figure 23 An example of a donor substrate with two different microdevice blocks is illustrated.

[0069] Figure 24 Examples of receiving substrates with skew blocks having different microdevices are illustrated.

[0070] Figure 25A Examples of donor substrates with three different types of microdevice blocks are illustrated.

[0071] Figure 25B The illustration shows instances of filling the box with different blocks to eliminate the inhomogeneities found in any one block.

[0072] Figure 26 Examples of cassette substrates with various types of microdevice blocks are illustrated.

[0073] Figure 27 Examples of cassette substrates with various types of offset microdevice blocks are illustrated. Detailed Implementation

[0074] While this teaching has been described in conjunction with various embodiments and examples, it is not intended that this teaching be limited to such embodiments. Rather, those skilled in the art will understand that this teaching encompasses various alternatives and equivalents.

[0075] In this invention, a pad on a receiving substrate refers to a designated area on the receiving substrate in which a microdevice has been or will be transferred from an donor substrate. The pad may be conductive to provide a connection between the microdevice and pixel circuitry, or the connection to pixel circuitry may be under the pad or on the side of the pad. The pad may have some form of bonding material for permanently holding the microdevice. The pad may be multilayered to provide a more mechanically stable structure and also to provide better functionality, such as bonding and conductivity.

[0076] The pads described herein can provide at least one of the following: electrical connection, mechanical connection, and a defined area for transferring microdevices. The shapes of the pads used in the illustrated embodiments are for illustrative purposes only, and the pads can have any shape. Changing the position of the pads relative to the pixels has no effect on the embodiments. The orientation of a group of pads in a pixel can be changed. For example, the pads can be rotated, shifted, or moved to different locations. The pads can have a composite structure including different conductive, semiconductor, and dielectric layers. The pads can be positioned on top of other structures (e.g., transistors) in the receiving substrate. Furthermore, the pads can be adjacent to other structures on the receiving substrate.

[0077] The shapes of the microdevices used in the embodiments are for illustrative purposes, and the microdevices may have different shapes. The microdevice may have one or more pads on the side that will contact the receiving substrate. The pads may provide mechanical or electrical connections or a combination of both.

[0078] In one embodiment, a method for arranging microdevices in an donor substrate is described, the method being used to transfer the microdevices to a receiving substrate. In the donor substrate, the microdevices are arranged relative to a pixel region, and within the region associated with the pixel, the microdevices may have a spacing smaller than the pixel pitch.

[0079] In this arrangement, the spacing between microdevices at the boundary of two pixels can be different from the spacing between microdevices within a pixel.

[0080] In this situation, there are more microdevices on the donor substrate than the intended / desired pads associated with the donor substrate region in the receiver substrate. Therefore, the microdevices may interfere with other undesired / unintended pads in the receiver substrate. Several embodiments in this document are described to define interfering regions for the donor substrate, in which microdevices can be removed or left unfilled. This embodiment can be used for different microdevice arrangements in the donor substrate.

[0081] In another embodiment, a method of arranging the microdevices described in the donor substrate to avoid interfering with the undesired pad includes...

[0082] a) Define the interference area or the non-interference area, where:

[0083] 1) The interference-free region is the space in the donor substrate that is not covered by other non-desired pads during the transfer of the microdevice to the receiving substrate; that is, the interference region is covered by non-desired pads, or

[0084] 2) After offsetting the donor substrate or receiver substrate in a specific direction to align at least one microdevice with a desired pad in the receiver substrate, following the transfer of at least one microdevice (different from the microdevice) to a pad (different from the pad) in the receiver substrate, the pad will not be covered by the pad; that is, the interference area will be covered by the pad in subsequent steps.

[0085] b) Arrange the microdevice in an interference-free region of the donor substrate.

[0086] In the receiving substrate described above, a pad on the receiving substrate can have a higher structure, and the microdevice associated with the pad can have a lower structure. Therefore, there will be no interference region for such a pad.

[0087] To increase the interference-free area, one embodiment includes a method of arranging pads associated with the transfer location of microdevices in a receiving substrate into a cluster, wherein within the cluster, the pad spacing is smaller than the sub-pixel spacing.

[0088] In the case of clustered pads, the donor substrate for the pads at the edge of the cluster can be arranged such that the interfering region and the non-interfering region are similar to the pixel region, wherein the width of the interfering region is the same as the distance of the other pads from the pad.

[0089] In the case of clustering, an donor substrate can be arranged for the pads within the cluster, whereby the interfering and non-interfering regions resemble pixel regions, and the interfering regions are defined by the following operation:

[0090] a) Determine the distance between the pad and the edge of the cluster;

[0091] b) Select a microdevice as a reference device on the donor substrate;

[0092] c) The interference area is defined by the micro-devices on both sides, similar to the distance from the edge of the associated pad to the cluster.

[0093] The pattern of interfering and non-interfering regions, defined by regions associated with pixels on the donor substrate, can be repeated on the donor substrate similar to the pixel pitch.

[0094] In the remaining area of ​​the patterned (arranged) donor substrate associated with each pixel for use as an intermediate pad, a column (or row) of microdevices is located between interfering regions with a width greater than the minimum distance of the intermediate microdevices from the edge of the cluster.

[0095] In one embodiment used to maximize the interference-free area, the pad spacing within the cluster may be the same as the microdevice spacing in the donor substrate.

[0096] In another embodiment used to maximize the undisturbed area, the pads may be arranged in a two-dimensional cluster. The pads in the cluster may be aligned with at least one other pad.

[0097] In one embodiment, the donor substrate for the pads can be aligned with other pads in two directions, thereby creating diagonal interference regions oriented relative to the pad cluster. These regions may contain other pads, and the remaining region associated with the pixel is an interference-free region, in which microdevices may be present.

[0098] In another embodiment, the donor substrate for the pad may be aligned with the pad in only one direction, the donor substrate having an interference region as follows:

[0099] A row that includes other pads, provided that the pads are vertically aligned with the other pads, or

[0100] One column, provided that the pad is horizontally aligned with another pad.

[0101] Therefore, the remaining area associated with the pixel is an interference-free area, in which microdevices may exist.

[0102] In this embodiment, the donor substrate and / or cartridge can be used interchangeably. The properties of the donor substrate can be applied to the cartridge and vice versa.

[0103] Figure 1 The donor substrate 150 is illustrated, in which there are more microdevices 160 than the associated pads in the receiving substrate, for example, see [reference needed]. Figure 2 And 3. In this case, the microdevice 160 may have a spacing 170 smaller than the pixel pitch of the receiving substrate in the pixel-associated region or block 130 of the donor substrate. Furthermore, since the pixel pitch may not be a multiple of the microdevice pitch 170, the microdevice pitch 180 between two adjacent (vertically and horizontally) pixel regions 130 and 140 may have different spacings, such as gaps or interference regions, to accommodate the difference between the pixel pitch and the microdevice pitch.

[0104] In conventional placement, microdevices 160 on a transfer head (e.g., donor substrate 150) are transferred one at a time or row at a time to a position on a receiving substrate. To fill the remainder of the receiving substrate or another receiving substrate, the transfer head needs to be refilled or a new donor substrate 150 must be used. This process requires rapid and accurate movements and precise alignment each time to avoid the microdevices 160 on the donor substrate 150 interfering with other microdevices 160 already on the receiving substrate or other pads on the receiving substrate not designated for receiving said particular microdevice 160. However, the present invention allows more microdevices 160 than are needed to fill the equivalent area on the receiving substrate to be placed on the donor substrate 150, thereby minimizing the refilling steps. Therefore, blank or empty areas on the donor substrate 150 allow the donor substrate 150 (or the receiving substrate) to be offset during the transfer process to align the remaining set of microdevices 160 with corresponding positions in the receiving substrate. This offset can be done independently, or it can be a movement of the donor substrate 150 to a new position on the receiving substrate or a portion of a new receiving substrate.

[0105] Figure 2A pixel structure in a receiving substrate 200 is illustrated. A pixel array on the receiving substrate 200 can be fabricated using different orientations and combinations of this pixel structure. The pixel structure includes different microdevices, and each microdevice may have different pixel circuitry or pixel connections. Pads 204, 214, 224 for each microdevice type are placed in each designated sub-pixel region 202, 212, 222, respectively, having widths of 208, 218, and 228, and are repeated in both the x and y directions to form a pixel array. In the illustrated embodiment, the receiving substrate 200 includes three different pads 204, 214, 224 spaced 216 and 226 for three different microdevices. However, any number of different microdevices can be used. In one pixel array structure, the microdevice type (or sub-pixel type) varies only in one direction (unidirectional array structure). In another array type, the microdevices may vary in two or more directions (bidirectional array). If the donor substrate 150 for each device type has microdevices 160 in all regions, i.e., a fully filled 2×2 array, then the microdevices 160 may interfere with pads 204, 214, and 224 during the transfer process in regions corresponding to pads 204, 214, and 224 of other microdevice types. In one case, the microdevices 160 remain on the donor substrate 150 only in regions associated with the corresponding pad (e.g., 204) on the receiving substrate 200. However, in this case, the donor substrate 150 needs to be replaced or refilled after each transfer, which reduces processing steps. Furthermore, if the microdevices 160 cannot be reset, the microdevice utilization rate may be affected. In one aspect of the invention, the donor substrate 150 for each microdevice 160 is divided into interfering regions and non-interfering regions. The microdevices 160 from the interfering regions of the donor substrate 150 are removed or left unfilled. In one aspect of the invention, the microdevice 160 is arranged in the donor substrate 150 to avoid interfering with undesired pads, such as 214 and 224, wherein the method comprises:

[0106] a) Define the interference-free area as:

[0107] i) A space in the donor substrate 150 that does not correspond to, overlap with, or interfere with other non-desired pads 204, 214, 224 on the receiving substrate 200 during the transfer of the first set of microdevices 160 to the first set of pads 204 on the receiving substrate 200; and

[0108] ii) A space in the donor substrate 150 that does not correspond to, overlap with, or interfere with pads 204, 214, and 224 after the donor substrate 150 or the receiver substrate 200 are respectively offset in a specific direction so that the second set of microdevices 160 and the second set of desired pads 204, 214, and 224 in the receiver substrate 200 are aligned after at least the first set of microdevices 160, which are different from the second set of microdevices 160, are transferred to the second set of desired pads 214 or 224 in the receiver substrate 200, which are different from the first set of pads 204; and

[0109] b) The microdevice 160 is arranged only in the interference-free area of ​​the donor substrate 150.

[0110] Alternatively, the method may include:

[0111] a) Define the interference area as:

[0112] i) Spaces in the donor substrate 150 that correspond to, overlap with, or interfere with other undesired pads 204, 214, 224 on the receiving substrate 200 during the transfer of the first set of microdevices 160 to the first set of pads 204 on the receiving substrate 200; and

[0113] ii) The space in the donor substrate 150 that corresponds to, overlaps with or interferes with pads 204, 214 and 224 after the donor substrate 150 or the receiver substrate 200 is offset in a specific direction so that the second set of microdevices 160 is aligned with the second set of pads 214 or 224 in the receiver substrate 200 or a different receiver substrate, after the first set of microdevices 160, which is at least different from the second set of microdevices 160, has been transferred to the second set of pads 214 or 224 in the receiver substrate 200, which is different from the first set of pads 204; and

[0114] b) The microdevice 160 is arranged only in the non-interference region of the donor substrate 150, rather than in the interference region.

[0115] In one method of defining interference-free regions, the orientation of the offset donor substrate 150 (or receiver substrate 200) relative to the receiver substrate 200 (or donor substrate 150) is defined. For example, after transferring the first set of microdevices 160 from the donor substrate 150 to the first set of pads 204, the donor substrate 150 is offset horizontally and vertically. After transferring the first set of microdevices 160 from the donor substrate 150 to the receiver substrate 200, the donor substrate 150 is offset horizontally or vertically. Another set of microdevices 160 may be aligned with other associated pads 214 or 224 and transferred to these pads, which may be the original receiver substrate 200 or a different receiver substrate. The following procedure is an exemplary process that can be used to identify interference regions and interference-free regions.

[0116] a) Use the first set of microdevices for transfer to the receiving substrate as a reference.

[0117] b) Draw a line parallel to the offset direction from the reference microdevice.

[0118] c) The reference pad on the reference donor substrate is drawn in an offset direction from the corresponding pad used for other types of microdevices.

[0119] d) Identify the line of the microdevice closest to the donor substrate from other types of microdevices.

[0120] e) Draw a line between the selected line and the microdevice line. This line has a similar distance from each of the microdevice line and the selected line.

[0121] f) The area defined by the new line and encompassing the microdevice is the interference-free area. Other areas are defined as interference areas.

[0122] Figure 3A This illustrates an example defining a non-interference region 304-1 and an interference region 304-2. Pixel region 330 includes both the non-interference region 304-1 and the interference region 304-2, respectively. In this case, the microdevice is offset both horizontally and vertically. Therefore, the width w of the non-interference region 304-1 for each microdevice... ni It is half the sum of the distances w1 and w2 between the pad 304 used for the microdevice and the other adjacent pads 314 and 324, respectively. Figure 3B In this process, the device is offset horizontally and diagonally. Therefore, the interference-free region 304-1 has a slope similar to that of the diagonal offset process. As can be seen in both cases, the interference-free region 304-1 is smaller than the interference region 304-2.

[0123] To solve this problem, such as Figure 4 One solution illustrated is to make one of the pads 414 higher than at least one of the other pads 404, 424. The microdevice 414-D using the higher pad 414 can be a more expensive device or more commonly used on the receiving substrate 400. However, it can also be any other device. In the illustrated embodiment, the other microdevices 404-D and 424-D can have a taller structure than the microdevice 414-D associated with the higher pad 414, thereby achieving a combination of heights for the pads 414 and the device 414-D that is substantially the same as the heights of the pads 404 and the device 404-D. One way to implement a taller device is to have a taller connection pad. The taller pad can be on either side of the device. Figure 4An exemplary receiving substrate 400 is shown with one or more pads 414 higher than other pads 404, 424. In the illustrated embodiment, three different microdevices 404-D, 414-D, and 424-D are transferred from donor substrates 450-04, 450-14, and 450-24 to the receiving substrate 400, respectively. Microdevices 404-D and 424-D associated with the lower pad structures 404 and 424 have a higher structure than the other microdevice 414-D. The same technique can be applied to other combinations of microdevices (more or fewer than three microdevices). Therefore, the lower microdevice 414-D will not interfere with the lower pads 404 and 424, and the interference area on the donor substrate 450-14 is minimized.

[0124] In such Figure 5 In another solution illustrated, pads 504, 514, and 524 for different microdevices can be positioned close to each other within cluster 540, leaving a large area or gap between clusters. In one embodiment, for ease of implementation, circuitry or other connections associated with pads 504, 514, and 524 can be defined by sub-pixel structures #1, #2, and #3, each having widths 508, 518, and 528, respectively. In another embodiment, the circuitry and connections can have any other structure. The closer the pads 504, 514, and 524 are, the larger the interference-free area 506 will be. In one case, the distance between two pads (e.g., 216 or 226) can be equal to or less than half the pixel pitch 530 of the three different microdevices (three different sub-pixels) on the donor substrate. For more or fewer sub-pixels (microdevice types), pads 504, 514, and 524 can similarly be placed closer together. In one embodiment, the distances 216 and 226 between pads 504, 514, and 524 in cluster 540 are similar to the microdevice spacing on the donor or cartridge substrate. If different microdevices have the same spacing on the donor substrate, then cluster pads 504, 514, and 524 will have the same spacing. In another case, the distance between pads 504, 514, and 524 in cluster 540 is a multiple (e.g., twice) of the microdevice spacing on the donor substrate. In yet another embodiment, the distance between the pads may be smaller than the microdevice spacing on the donor substrate. Figure 5 A receiving substrate is shown as an example of a pad cluster 540. These pads 504, 514, and 524 may originate from sub-pixels 502, 512, and 526 within a single pixel 530 or from different pixels. Pads 504, 514, and 524 may be located at any position relative to pixel 530. It is possible that the order and position of pads 504, 514, and 524 may differ for different pixels.

[0125] Figure 6AThe diagram shows an interference region 604-1 and an interference-free region 604-2 for pad 604 at the edge of cluster 640. The same structure can be used for another pad 624 on the other side of cluster 640. As can be seen, the interference-free region 604-2 for pads 604 and 624 at the edge of cluster 640 is larger than in the previous case. For the middle pad 614, the interference-free region 614-1 and the interference region 614-2 can be as follows: Figure 6B The stripe pattern shown is illustrated here. The width of the stripe is the same as the distance between the central pad 614 and the other pads 604 and 624. To define a non-interference area, the following steps can be used:

[0126] a) Calculate the distance between the edge of pad 604 and the edge of the clustered pad.

[0127] b) Select a microdevice as a reference device in the donor substrate.

[0128] c) An interference area is defined from the microdevice to both sides, similar to the distance from the edge of the associated pad to the cluster.

[0129] The pattern of interfering and non-interfering regions, defined by the areas associated with pixels in the donor substrate, can be similar to the pixel pitch repeating in the donor substrate. In the remaining patterned (arranged) area of ​​the donor substrate associated with each pixel for the intermediate pads, a column (or row) of microdevices is situated between interfering regions whose width is greater than the minimum distance of the intermediate microdevices from the edge of the cluster. If the distances between the intermediate pads and the other pads are the same, then the ratio of interfering region 614-1 to non-interfering region 614-2 can be the same. Similar to... Figure 3B Depending on the offset direction, the interfering region 614-1 and the non-interfering region 614-2 can have different shapes. Furthermore, similar to... Figure 4 The intermediate pad can be relatively high, and therefore in this case, the interference-free area for the intermediate microdevice can be the entire donor substrate.

[0130] If the microdevices do not have similar spacing, then the distances between pads 604, 614, and 624 in cluster 640 can be similar to any of the spacings of the microdevices, or each pad 604, 614, and 624 can have different distances from the other pads. To improve the interference-free area, the intermediate devices can be devices with larger spacing, thereby using higher pads can help improve the interference area.

[0131] Figure 7AAn embodiment is illustrated where pads 704, 714, and 724 in the receiving substrate 700 have the same spacing as microdevices 752 and 754 in the donor substrate 750. The position of the pad cluster 740 may be different relative to the pixel 730 on the receiving substrate 700. The dimensions of pads 704, 714, and 724 may be smaller than, similar to, or larger than microdevices 752 and 754. The shapes of microdevices 752 and 754, as well as pads 704, 714, and 724, may be any suitable shape and size. In this case, microdevices 752 and 754 may be removed (or left unfilled) from interfering areas on the donor substrate 750, thereby creating void regions on the donor substrate 750 corresponding to currently or future filled or unfilled pads on the receiving substrate 700 and any subsequent receiving substrates, which are not designated to receive one of the microdevices from the current donor substrate 750.

[0132] Figure 7A An embodiment of edge pad 704 is illustrated (a similar structure may be used for 724). In the illustrated embodiment, the donor substrate 750 includes an array of microdevices 752 separated by void regions, each void region having at least one width substantially equal to the sum of the spacings of adjacent pads (e.g., pads 704 to 714 and pads 714 to 724) (for equally spaced pads, spacing × N (number of adjacent pads)). The minimum distance between the void regions (i.e., the distance between the arrays of microdevices 752 on the donor substrate 750) is the distance from the side closest to the filled pad (e.g., pad 714) to the opposite side furthest from the filled pad (e.g., pad 724). In other words, it is the area used to cover the other pads 714 and 724 without interfering with them during the current or any future transfer step. The donor substrate 750 may be composed of a plurality of columns and rows of microdevices 752 and 754, and includes on each side a gap region defined by a number of missing columns or rows equal to the number of pads (e.g., 714 and 724) adjacent to the receiving pad (e.g., 704). The number of columns in each array depends on the spacing between pads 704 and 724 in adjacent pixels 730. For example, if the spacing of microdevices 752 and 754 is the same as that of pads 714 and 724, then the donor substrate 750 may include a gap region with two missing columns of microdevices for a pad 704 that includes two adjacent pads 714 and 724 on the right side but no pad on the left side. Alternatively, if the spacing is different, then the gap region may be at least a distance from the pad (e.g., pad 704) mounted to the far edge of the farthest pad (e.g., pad 724).

[0133] Some of the microdevices 754 may have been transferred to the receiving substrate 700, and the donor substrate 750 (or receiving substrate 700) may be vertically and / or horizontally offset relative to the next receiving substrate 700 (or donor substrate 750), such that another microdevice 754 is aligned with one of the bare pads 704 (pads to which no microdevices have been transferred). In this case, the blank space created by transferring the microdevices 754 will be a new blank area on top of pad 714, and when the receiving substrate 700 (or donor substrate 750) is subsequently offset again, the blank space that was originally on top of pad 714 will be on top of pad 724. Thus, microdevices 752 and 754 will not interfere with pads 714 and 724 that are not intended. We can complete all the microdevices in a column by first vertically offsetting and then moving to the next column (e.g., moving to column 1 after completing column 2). However, other combinations of vertical and horizontal offsets can be used. Pixels 730 or pad clusters 740 can be angled vertically or horizontally. In this case, several rows or columns of microdevices will also be tilted. Furthermore, the microdevices can be angled, while the pads or pixels are not angled. In this case, the offset direction will be towards the angle of the column or row.

[0134] Figure 7BA similar structure is shown above, but for the intermediate pad 714, with the donor substrate 751 aligned with the receiver substrate 700 before or after the donor substrate 750. In the illustrated embodiment, the array (e.g., a 1×N array) of microdevices 753 and 755 is separated by gap regions, each gap region having a width substantially equal to the sum of the spacings of adjacent pads (e.g., pads 704 and 724) (e.g., spacing for equally spaced pads × N (N = number of adjacent pads)). The minimum distance between the gap regions (i.e., the distance between the arrays of microdevices 753 on the donor substrate 751) is the distance from the side closest to the filled pad (e.g., pad 704 or 724) to the opposite side furthest from the filled pad (e.g., the same pad 704 or 724). In other words, the gap region has sufficient space, i.e., the distance between the arrays of microdevices 753, to cover other pads 704 and 724 without interfering with them during the current or future transfer steps. Typically, the length of the gap region is the full length of the donor substrate 751. For a pad cluster 740 of three pads 704, 714, and 724, the donor substrate 751 for the middle pad 714 may contain an array of microdevices 753 that are laterally separated to twice the pad spacing and vertically separated to the pad spacing. The donor substrate 751 may be composed of a number of columns and rows of microdevices 753 and 755, and on each side therein includes a gap region defined by a number of missing columns or rows equal to the number of pads (e.g., 704 and 724) adjacent to the receiving pad (e.g., 714). The number of columns in each array depends on the spacing between pads 704 and 724 in adjacent pixels 730. For example, if the spacing between microdevices 753 and 755 is the same as that between pads 714 and 724, then the donor substrate 751 for receiving pad 714, which includes an adjacent pad 704 on the left and a pad 724 on the right, may include a gap region on each side with a missing column of microdevices. Alternatively, if the spacing is different, then the gap region may be at least the distance from the pad (e.g., pad 714) mounted to the far edge of the farthest pad (e.g., pad 704 or 724).

[0135] Figure 8Another pixel orientation embodiment 850 illustrates the distribution of subpixels 802, 812, and 822 in two dimensions (e.g., horizontally and vertically). Pads 804, 814, and 824 are shown in each corresponding subpixel 802, 812, and 822 region. A horizontal distance 806 lies between pads 804 and 824, a horizontal distance 816 lies between pads 804 and 814, a horizontal distance 826 lies between pads 824 and 814, and a vertical distance 836 lies between pad 824 and pads 804 and 814. Distances 806, 816, 826, and 836 are used to define interference areas and interference-free areas. Subpixels 802, 812, and 822 can be aligned in both vertical and horizontal orientations (or diagonally). For example, pads 814 and 824 can be vertically aligned, and therefore the horizontal distance 826 can be zero.

[0136] Figures 9A to 9D Examples of interference and non-interference areas are shown for different pads 904, 914, and 924. Figure 9A This refers to pad 904, which is based on the horizontal and vertical offset of a microdevice. In this case, the non-interference region 904-1 and the interference region 904-2 can be a combination of boxes that are offset around or from pads 904, 914, 924. Figure 9B Another example of interference-free region 904-1 and interference region 904-2 for pad 904 is shown. Here, the common portion (denominator) of the two interference-free regions between pads 904 and 914 and between pads 904 and 924 is used as the interference-free region for pad 904. Figure 9C The diagram shows the horizontally undisturbed area 924-1 and the horizontally disturbed area 924-2. For pad 914, the optimal case is based on diagonal offset. Figure 9D This demonstrates diagonal stripes for the interference-free region 914-1 and the interference region 914-2. Other patterns can also be used with different offset directions. In this embodiment, such as... Figure 4 The different pad heights described herein can improve the utilization rate of some pad improvement devices.

[0137] Figure 10 Another embodiment of clustered pads 1040 is illustrated, wherein pads 1004, 1014, and 1024 are in two dimensions. Similar to... Figure 5 Depending on the different spacing of the microdevices on the donor substrate, pads 1004, 1014 and 1024 can have different spacings.

[0138] Figure 11A The diagram illustrates the interference-free region 1104-1 and interference region 1104-2 of the pad 1104 at the edge of cluster 1140. Compared to the previous case, the interference-free region for the pad at the edge is larger. Figure 11BThe diagram shows the interference-free region 1124-1 and the interference region 1124-2 for pad 1124. For pad 1114 in the middle, the interference-free region 1114-1 and the interference region 1114-2 can be as follows: Figure 11C The diagonal stripe pattern shown is illustrated. Here, the width of the stripes is the same as the distance between the central pad 1114 and the other pads 1104 and 1124 (e.g., center-to-center or diagonal spacing). If the distance between the central pad 1114 and the other pads 1104 and 1124 is the same, then the ratio of the interfering region 1114-2 to the non-interfering region 1114-1 can be the same. Similar to... Figure 3B Here, depending on the offset direction, the two regions can have different shapes. Furthermore, similar to... Figure 4 The intermediate pad 1114 can be relatively high, and therefore in this case, the interference-free region 1114-1 for the intermediate microdevice 1114 can be the entire donor substrate.

[0139] Figures 12A to 12D An embodiment is illustrated where pads 1204, 1214, and 1224 in the receiving substrate 1200 have the same spacing as microdevices 1252 and 1254 in the donor substrate 1250. The position of the pad cluster 1240 on the receiving substrate 1200 may be different relative to the pixel 1230 on the donor substrate 1250. The dimensions of pads 1204, 1214, and 1224 may be smaller than, similar to, or larger than microdevices 1252 and 1254. The shapes of microdevices 1252 and 1254 and pads 1204, 1214, and 1224 may be any suitable shape and size. In this embodiment, microdevices 1252 and 1254 are removed (or left unfilled) from interfering areas on the donor substrate 1250.

[0140] Figure 12AAn embodiment is illustrated for an donor substrate 1250 for edge pads 1204. Some of the microdevices 1254 may have been transferred to a receiving substrate 1200, and the donor substrate 1250 (or receiving substrate 1200) is vertically and / or horizontally offset relative to the next receiving substrate 1200 (or donor substrate 1250), such that another microdevice 1254 is aligned with a bare pad 1204 (a pad to which no microdevice has yet been transferred) on the subsequent receiving substrate 1200. In the illustrated embodiment, multiple arrays or blocks of microdevices 1252 and 1254 are provided on the donor substrate 1250. Within each array of microdevices, the spacing or pitch of the microdevices may be consistent, for example, a first predetermined spacing, ideally the same spacing or pitch as that of pads 1204 and 1214. Each microdevice array is separated by gaps, which are interference regions defined by a distance of at least N times the spacing or interval between pads (e.g., 1204 or 1214) or from the side closest to the farthest pad to the farthest pad, where N is the number of adjacent pads (e.g., 1204 or 1214). Typically, the length of the gap region is the full length of the donor substrate 1250. In this case, the blank space on the donor substrate 1250 created by transferring the microdevice 1254 can be a new blank region, which can be on top of other pads 1214, 1224 in the subsequent receiving substrate 1200. Thus, the microdevice will not interfere with non-desired pads 1214, 1224. All microdevices 1254 in a column can be completed by first offsetting vertically and then moving to the next column (e.g., moving to column 1 after completing column 2). However, other combinations of vertical and horizontal offsets can be used. Pixels 1230 or pad clusters 1240 can be angled vertically or horizontally. In this case, several rows or columns of microdevices will also be tilted. Furthermore, microdevices 1252 and 1254 can be angled, while pads or pixels are not angled. In this case, the offset direction will be towards the angle of the column or row.

[0141] The donor substrate 1250 may be composed of a plurality of columns and rows of microdevices 1252 and 1254, and includes on each side a gap region defined by a number of missing columns or rows equal to the number of pads (e.g., 1214) adjacent to the receiving pad (e.g., 1204). The number of columns in each array depends on the spacing between pads 1204 and 1214 in adjacent pixels 1230. For example, if the spacing of microdevices 1252 and 1254 is the same as that of pads 1204 and 1214, then the donor substrate 1250 may include a gap region with a missing column of microdevices for a pad 1204 that has an adjacent pad 1214 on the right (pad 1224 is at the same lateral distance) but no pad on the left. Alternatively, if the spacing is different, then the gap region may be at least the distance from the pad (e.g., pad 1204) mounted to the far edge of the farthest pad (e.g., pad 1214).

[0142] Figure 12B Display as Figure 12A A similar structure to the donor substrate 1260 for the intermediate pad 1224 on the receiving substrate 1200 is described. However, interference regions without microdevices extend horizontally across the donor substrate 1260 to avoid interfering with pads 1204 and 1214. As described above, each donor substrate 1260 contains multiple arrays or blocks of microdevices 1253 and 1255. Within each array of microdevices, the spacing or pitch of the microdevices may be the same, for example, a first predetermined spacing, ideally the same spacing or pitch as pads 1204 and 1214, but may have larger or smaller spacing. Each array of microdevices 1253 is separated by gaps, which are interference regions that are N times the spacing or pitch between pads (e.g., 1204 or 1214) from the side closest to the pad to the far side of the farthest pad, where N is the number of adjacent pads (e.g., 1204 and 1214). Typically, the length of the gap region is the full length or full width of the donor substrate 1260. For the subsequent receiving substrate 1200, the donor substrate 1260 for the intermediate pad 1224 moves laterally, that is, moves perpendicular to the donor substrate 1250 for the pad 1204.

[0143] Figure 12C A donor substrate 1270 is shown for the intermediate pad 1214. Here, the interference region is diagonally, for example, at an acute angle, relative to the side of the donor substrate 1270, and the offset of the donor substrate 1270 (or receiving substrate 1200) relative to the subsequent receiving substrate 1200 (or donor substrate 1250) is completed diagonally or vertically and horizontally. The donor substrate 1270 may be composed of a plurality of columns and rows of microdevices 1257 and 1259, and includes on each side a gap region defined by a number of missing columns or rows equal to the number of pads (e.g., 1204 and 1224) adjacent to the receiving pad (e.g., 1214). The number of columns in each array depends on the spacing between pads 1214 and 1204 in adjacent pixels 1230. For example, if the spacing between microdevices 1257 and 1259 is the same as that between pads 1214 and 1224, then the donor substrate 1270 may include a void region with a missing diagonal column of microdevices for pad 1214, which includes an adjacent pad 1204 on the left and a pad 1224 below (the two pads are diagonally opposite each other at the same lateral distance). Alternatively, if the spacing is different, then the void region may be at least the distance from the pad (e.g., pad 1214) mounted to the far edge of the farthest pad (e.g., pad 1224).

[0144] Figure 12DThe donor substrate 1270 is illustrated, which has a similar structure to donor substrate 1260 for transfer to pad 1214, but has a slightly different arrangement for microdevices 1257 and 1259 to maximize transfer. The voids in donor substrate 1270 are parallel (or perpendicular) to the sides of donor substrate 1270, but donor substrate 1270 is rotated relative to receiver substrate 1200, for example, by 45°.

[0145] Figure 13A This diagram illustrates the interference-free region 1304-1 and interference region 1304-2 of the pad 1304 at the edge of cluster 1340, corresponding to a pixel width 1350 of the void region on the donor substrate. As can be seen, the interference-free region 1304-1 of the edge pad is larger than in the previous case. The same pattern can be used for pad 1314. For the pad 1324 in the middle, the interference-free region 1314-1 and interference region 1314-2 can be as follows: Figure 13B The vertical stripe pattern shown is as follows. Here, the width of the interference-free area 1324-1 is the same as the distance between the middle pad 1314 and the other pads 1304 and 1324 in the other pixels. If the distance between the middle pad and the other pads is the same, then the ratio of the interference area 1324-2 to the interference-free area 1324-1 can be the same. Similar to... Figure 3B Here, depending on the offset direction, the interfering region 1324-2 and the non-interfering region 1324-1 can have different shapes. Furthermore, similar to... Figure 4 One of the pads can be higher, and therefore in this case, the interference-free area for the intermediate microdevice can be the entire donor substrate.

[0146] Figure 14A and 14B An embodiment is illustrated where pads 1404, 1414, and 1424 in receiving substrate 1400 have the same spacing as the microdevices in donor substrates 1450 and 1460. The position of pad cluster 1440 may be different relative to pixel 1430. The dimensions of pads 1404, 1414, and 1424 may be smaller than, similar to, or larger than microdevices 1452, 1454, 1455, and 1457. The shapes of microdevices 1452, 1454, 1455, and 1457, as well as pads 1404, 1414, and 1424, may be any suitable size or shape. In this case, microdevices 1452, 1454, 1455, and 1457 may be removed (or left unfilled) from interfering areas on donor substrates 1450 and 1460.

[0147] Figure 14AAn embodiment is illustrated for an donor substrate 1450 for edge pads 1404. Some of the microdevices 1454 may have been transferred to a receiving substrate 1400, and the donor substrate 1450 (or receiving substrate 1400) is vertically and / or horizontally offset relative to the next receiving substrate 1400 (or donor substrate 1450), such that another microdevice 1452 is aligned with one of the bare pads 1404 (pads to which no microdevices have yet been transferred). In the illustrated embodiment, multiple arrays of microdevices 1452 and 1454 are provided on the donor substrate 1450. Within each array of microdevices, the lateral and vertical spacing or pitch of the microdevices may be the same, for example, a first predetermined spacing, ideally the same spacing or pitch as that of pads 1404 and 1414. Each microdevice array is separated by gaps, which are either the spacing between pads (e.g., 1414 and 1424) or the interval between pads, or an interference region consisting of N times the lateral or vertical distance from the side closest to the pad to the farthest side of the pad, where N is the number of laterally or vertically adjacent pads, for example, two pads 1414 and 1424 in this case. Typically, the length of the gap region is the full length of the donor substrate 1450.

[0148] In this case, the blank space created by transferring microdevice 1454 will become a new blank area, which will be on top of the other pads 1414 and 1424. Therefore, the microdevice will not interfere with the non-target pads 1414 and 1424. All microdevices in a column can be completed by first offsetting vertically and then moving to the next column (e.g., moving to column 1 after completing column 2). However, other combinations of vertical and horizontal offsets can be used. Pixels 1430 or pad clusters 1440 can be angled relative to each other, either vertically or horizontally. In this case, several rows or columns of microdevices can also be tilted. Furthermore, microdevices can be angled, while pads or pixels are not. In this case, the offset direction will be towards the angle of the column or row.

[0149] The donor substrate 1450 may be composed of a plurality of columns and rows of microdevices 1452 and 1454, and includes on each side a gap region defined by a number of missing columns or rows equal to the number of pads (e.g., 1414 and 1424) adjacent to the receiver pad (e.g., 1404). The number of columns in each array depends on the spacing between pads 1424 and 1404 in adjacent pixels 1430. For example, if the spacing between microdevices 1452 and 1454 is the same as that between pads 1414 and 1424, then the donor substrate 1450 may include a gap region with two missing columns of microdevices for a receiver pad 1404 that has two laterally spaced adjacent pads 1414 and 1424 on the right side (pads 1414 and 1404 and 1424 are equally spaced) and no pads on the left side. Alternatively, if the spacing is different, the gap area may be at least the distance from the far edge of the pad (e.g., pad 1404) installed to the farthest pad (e.g., pad 1424).

[0150] Figure 14B Drawing similar to Figure 14A The structure is as follows, but for the donor substrate 1460 of the intermediate pad 1414. However, the interference areas that do not have microdevices 1455 and 1457 are horizontal gaps, for example, rows where a single row of microdevices is missing, for example, pads 1404 and 1424 are vertically spaced at a pitch distance from the receiving pad 1414.

[0151] Figure 15A An example of a multi-type microdevice cartridge 1800 is illustrated. The cartridge 1800 contains three different types (e.g., colors) of microdevices 1801, 1802, and 1803, such as blue, green, and red. However, any number and variety of different types of devices are possible. The distances between microdevices 1801, 1802, and 1803 (i.e., x1, x2, and x3 respectively) and the receiving substrate (e.g., from...) are shown. Figure 7A and 7BThe spacing of the landing areas in the receiving substrate 700 is related to the pixel pitch. After an array of microdevices 1805 or a first group of microdevices 1805 that can be related to the pixel pitch in the receiving substrate, different spacings x4, y2 may exist between microdevices 1801, 1802, and 1803 in adjacent groups 1805 and 1815, i.e., gap regions or interference regions. The separation or spacing is used to compensate for the mismatch between the pixel pitch and the microdevice pitch (landing area spacing) and to ensure that microdevices on the substrate or cartridge substrate 1800 do not interfere with pads, such as horizontal and vertical adjacent clusters 740, or existing microdevices on the receiving substrate (e.g., receiving substrate 700). For example, a gap region may be a region defined by a distance from at least one side of the outer pad of the pixel to the far side of the outer pad at the opposite side of the pixel, or at least N times the distance of the pad spacing, where N is the number of adjacent pads in the pixel. The length may be the entire length of the cartridge 1800. In this case, if the take-off is used to develop the box 1800, then the force element can be in the form of a column corresponding to each microdevice type, or the force element can be a separate element for each microdevice.

[0152] refer to Figure 15B During assembly, the first step 1821 involves fabricating a microdevice on the original donor substrate (e.g., donor substrate 750 or 1450). Next, in step 1822, the microdevice is fabricated to separate it from the donor substrate 750 or 1450. In step 1823, the microdevices from one or more donor substrates (e.g., 750 and 1450) are then transferred to a cartridge 1800, arranged according to the pixel arrangement on a receiving substrate (e.g., 700 or 1400). An optional next step 1824 involves identifying defective microdevices and correcting them in situ or removing them and replacing them with operational microdevices in step 1825. Defect identification can be performed in the cartridge 1800 before transfer or on the receiving substrate 700 or 1400 after transfer, or both. After or before the identification and correction steps 1824, in step 1826, multiple groups of pixel-forming microdevices 1801, 1802 and 1803 from each array or group of microdevices 1805, 1810 and 1815 may be simultaneously mounted from the cartridge 1800 onto the receiving substrate (e.g., receiving substrate 700).

[0153] refer to Figure 15CThe transfer step 1826 can be broken down into a logic loop, wherein the first step 18261 includes loading or selecting a first cartridge 1800. The next step 18262 includes selecting a set of microdevices on cartridge 1800 for transfer, the microdevices preferably having been tested for defects and including defects in numbers below a desired threshold (e.g., less than 10%). Step 18263 includes aligning the selected microdevices on cartridge 1800, for example, by moving or offsetting cartridge 1800 or a receiving substrate (e.g., receiving substrate 700) or both relative to the other to align with subsequent clusters of pads (e.g., cluster 740). The next step 18264 includes transferring the aligned microdevices on cartridge 1800 to pads on the receiving substrate (e.g., 700 or 1400). Step 18264 can be broken down into a sub-step including 18264a, wherein the selected microdevices from cartridge 1800 are connected to the receiving substrate (e.g., 700 or 1400). Sub-step 18264b includes activating the microdevice to test its connectivity to the receiving substrate (e.g., 700 or 1400). This testing can be performed by biasing the microdevice through cartridge 1800 and / or the receiving substrate (e.g., 700 or 1400). If defects are found in some of the microdevices, then step 18264c involves adjusting one or more of the bonding parameters of the microdevices to correct the cause of the defects. Step 18265 asks a logical question about whether the receiving substrate (e.g., 700 or 1400) is adequately filled. If yes, then in step 18266, the process continues to a new receiving substrate and the installation process is repeated. If no, then in step 18267, another question is asked to determine whether cartridge 1800 contains enough microdevices to continue with further transfer. If yes, then the process returns to step 18262 to select the next set of microdevices for transfer. If no, then the process returns to step 18261 to select another cartridge 1800.

[0154] Figure 16 Another example of a multi-type microdevice cartridge 1900 is illustrated. The cartridge 1900 contains three different types (e.g., colors) of microdevices 1901, 1902, and 1903. Other areas 1904 may be reserved microdevices or gap areas (interference areas). However, any number and type of different types of devices are possible. The distances x1, x2, and x3 between the microdevices are related to the receiving substrate (e.g., ...). Figures 12A to 12DThe spacing of the landing area in the receiving substrate 1200 is related to the pixel spacing in the receiving substrate. After the microdevice array or the first group of microdevices that can be related to the pixel spacing in the receiving substrate, different lateral and vertical spacings x4, y3 may exist between pixels in laterally and vertically adjacent groups, i.e., gap regions or interference regions. This spacing is used to compensate for the mismatch between the pixel spacing and the microdevice spacing (landing area spacing), and to ensure that microdevices on the substrate or housing 1900 do not interfere with pads, such as horizontally and vertically adjacent groups 1240, or existing microdevices on the receiving substrate (e.g., receiving substrate 1200). For example, a gap region may be a region defined by a distance at least from one side of the outer pad of the pixel to the far side of the outer pad at the opposite side of the pixel, or at least N times the spacing of the pads, where N is the number of adjacent (horizontally or vertically) pads in the pixel. The length may be the entire length of the housing 1900. During assembly, multiple groups of pixel-forming microdevices 1901, 1902, and 1903 from each array or group of microdevices can be simultaneously mounted on a receiving substrate (e.g., receiving substrate 1200). Then, cartridge 1900 or the receiving substrate (e.g., receiving substrate 1200), or both, are moved relative to the other to align with subsequent clusters of pads (e.g., cluster 1240), and the mounting process is repeated until cartridge 1900 is empty or the receiving substrate is filled. At this point, another cartridge 1900 or receiving substrate is introduced.

[0155] Figure 17 An example is illustrated of a microdevice (e.g., 1801 or 1902) fabricated on a donor substrate 1850 before being transferred to a multi-type microdevice cartridge (e.g., 1800 or 1900). Support layers 1860 and 1870 may be used for individual devices or groups of devices. The microdevice pitch x1 may match the pitch in cartridges 1800 or 1900, or may be a multiple of the cartridge pitch. As described above, the vertical and horizontal array pitches y2 and x4 provide gaps or interference regions to prevent microdevice 1801 from interacting with unwanted areas on the receiving substrate or on cartridges 1800 or 1900.

[0156] In all the structures described above, it is possible to move the microdevice from the first cassette to the second cassette before using it for filling the substrate. Additional processing steps may be performed after the transfer, or some of the processing steps may be divided between the first cassette structure and the second cassette structure.

[0157] Figure 18An example of a block of microdevices 1482 on a donor substrate 1480 is illustrated. The donor substrate 1480 may be any of the aforementioned donor substrates described herein. Due to manufacturing and material defects, the microdevices may have a gradual decrease or increase in output power across the donor substrate, i.e., non-uniformity, as illustrated by the combination of darker to lighter shading. Because the microdevices can be sequentially transferred to the receiving substrate one or more at a time, either together or in blocks 1482, the uniformity of adjacent devices in the receiving substrate gradually degrades. However, a worse problem may arise where a series of blocks 1482 ends and the next series begins, for example, along the intersection line 1484, which can lead to... Figure 19 The sudden changes exhibited in the image can cause visual artifacts in optoelectronic devices (such as displays).

[0158] To solve the problem of unevenness, Figure 20 One embodiment illustrated involves skewing or interleaving individual blocks 1482 relative to blocks below and above them in the display, such that the edges of the blocks are not sharp lines, i.e., intersection points 1484 are eliminated, thereby skewing the blocks 1482 into a skewed pattern on the display. This significantly reduces the average effect of abrupt changes. The skew can be random and can have different contours.

[0159] Figure 21 Another embodiment is illustrated in which microdevices in adjacent blocks are flipped so that devices with similar performance are adjacent to each other. For example, the performance in the first block decreases from the first outer side to the first inner side, while the performance of the second adjacent block increases from the second inner side adjacent to the first inner side to the second outer side. This makes the change very smooth and eliminates abrupt intersections 1484.

[0160] Figure 22 The illustration shows an exemplary combination of flipping the device, alternating high-performance and low-performance devices on the inside, and skewing the edges to further improve average uniformity. In the illustrated example, the device performance alternates between high and low in two directions (i.e., in adjacent horizontal blocks and in adjacent vertical blocks).

[0161] In one case, the performance of the microdevices at the edge of the block is matched against the adjacent transferred blocks (arrays) before transfer to the receiving substrate.

[0162] Figure 23 The illustration shows the use of two or more blocks 1580 and 1582 to fill a cartridge or receiving substrate 1590. Here, the skew or flipping method can also be used for further improvements, such as... Figure 24 The average uniformity exhibited. Furthermore, random or predefined patterns can be used to fill the cartridge or receiving substrate 1590 with microdevices from more than one block.

[0163] Figure 25AThe illustration shows more than one block 1680, 1682 and 1684 that may come from the same donor substrate or different donor substrates. Figure 25B Examples are illustrated of filling the box 1690 with different blocks to eliminate the inhomogeneities found in any one block.

[0164] Figure 26 and 27 The diagram illustrates a structure with multiple cartridges 1790. The positions of the cartridges 1790 are selected to eliminate overlap between the same area in the receiving substrate and cartridges with the same microdevices during different transfer cycles. In one case, the cartridges can be independent of the others, meaning that a single arm or controller handles each cartridge independently. In another case, alignment can be performed independently, but other actions can be synchronized. In this case, the substrate can move after alignment to facilitate transfer. In another case, the cartridges can move together after alignment to facilitate transfer. In yet another case, both the substrate and the cartridges can move to facilitate transfer. In yet another case, the cartridges can be pre-assembled. In this case, a frame or substrate can hold the assembled cartridges. The distances X3, Y3 between the cartridges 1790 can be multiples of the widths X1, X2 or the lengths Y1, Y2 of the cartridges 1790. They can be adjusted according to the movement step size in different directions. For example, X3 = KX1 + HX2, where K is the leftward (direct or indirect) movement step and H is the rightward (direct or indirect) movement step for filling the substrate. The same logic applies to the distance Y3 between cartridges and the lengths Y1 and Y2. Figure 26 As shown, the box can be aligned in one or two directions. Figure 27 In another scenario illustrated, the cartridges may not be aligned in at least one direction. Each cartridge 1790 may have independent controls for applying pressure and temperature toward the substrate. Other arrangements are also possible depending on the direction of movement between the substrate and the cartridge.

[0165] In another case, the cartridge 1790 may have different devices and thus be filled with different regions of the receiving substrate. In this case, the relative position of the cartridge 1790 to the receiving substrate changes after each transfer cycle to fill different regions with all the required microdevices from the different cartridges.

[0166] In another case, several arrays of cartridges 1790 are prepared. Here, after transferring the devices from the first cartridge array to the receiving substrate, the receiving substrate is moved to the next microdevice array to fill the remaining area in the receiving substrate or to receive different devices.

[0167] In another case, the cartridge 1790 may be on a curved surface, and thus cyclical movement provides contact for transferring the microdevice into the substrate.

[0168] The foregoing description of one or more embodiments of the invention has been presented for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible based on the foregoing teachings. The scope of the invention is intended to be limited not by this detailed description, but by the appended claims.

Claims

1. A method for filling a receiving substrate, the method comprising the following steps: Multiple microdevices are fabricated on one or more donor substrates; The plurality of microdevices are transferred from one or more donor substrates to a first cassette substrate, wherein the first cassette substrate contains three different types of microdevices and spare microdevices; the plurality of microdevices are arranged in an array and multiple sets of microdevices spaced apart on the first cassette substrate by gap regions, wherein the gap regions are configured to prevent interference with non-contact pads on the receiving substrate during the transfer of one or more sets of microdevices to corresponding contact pads on the receiving substrate; Select at least one microdevice group associated with the contact pad group in the receiving substrate in the first cartridge substrate; Identify the number of defective microdevices in the at least one microdevice group; If the number of defective microdevices in the group is greater than a set threshold, then the defective microdevices are corrected. and The selected microdevice group on the first cartridge substrate is aligned and transferred to the corresponding contact pad on the receiving substrate.

2. The method of claim 1, wherein if the receiving substrate is not fully filled after the selected group of microdevices has been transferred to the receiving substrate, the method further comprises the following steps: Determine whether the first substrate 1) has sufficient microdevices to continue transferring microdevices to the receiving substrate, or 2) does not have sufficient microdevices to continue transferring microdevices to the receiving substrate. In response to determining that the first cartridge substrate has sufficient microdevices, another group of microdevices in the first cartridge substrate is selected to be transferred to the receiving substrate; Otherwise, in response to determining that the first cartridge substrate does not have enough microdevices, a second cartridge substrate is selected, wherein the second cartridge substrate contains three different types of microdevices and a spare microdevice or void region.

3. The method of claim 1, wherein if the number of defective microdevices is greater than the set threshold, the defective microdevices are removed.

4. The method of claim 1, wherein if the number of the defective microdevices is less than the set threshold, the defective microdevices are repaired.

5. The method of claim 1, wherein if the number of the defective microdevices is less than the set threshold, the defective microdevices are replaced with spare microdevices on each substrate.

6. The method of claim 2, wherein the step of selecting one or more groups of microdevices on the first and second casing substrates comprises: Select one or more microdevice groups, wherein the number of defective microdevices in one or more microdevice groups is less than a threshold. and The selected group of microdevices is transferred to fill the receiving substrate.

7. The method of claim 2, wherein the first and second casing substrates comprise the plurality of microdevices of different types.

8. The method of claim 7, wherein the different types of microdevices include red microdevices, blue microdevices, or green microdevices.

9. The method of claim 1, wherein the different types of microdevices are arranged in an array on each cartridge according to the type of microdevice.

10. The method of claim 1, further comprising: The microdevice is biased via the receiving substrate to test the connection between the transferred microdevice and the receiving substrate.

11. The method of claim 1, further comprising: Adjust one or more of the engagement parameters of the microdevice to correct the cause of the defective microdevice.

12. The method of claim 1, wherein the distance between the plurality of microdevices on each cartridge substrate depends on the spacing of the corresponding contact pads on the receiving substrate.

13. The method of claim 1, wherein the rows of microdevices from each cartridge substrate are arranged obliquely on the receiving substrate to reduce the effects of abrupt transitions caused by inhomogeneities of the microdevices across each cartridge substrate.

14. The method of claim 1, wherein the lateral adjacent rows of the microdevices from different cartridge substrates are arranged in a flipped arrangement on the receiving substrate, wherein the high side or low side of a row from one of the donor substrates is adjacent to the high side or low side of an adjacent row of the other donor substrate, respectively, to reduce abrupt transitions caused by inhomogeneities of the microdevices across each cartridge substrate.

15. The method of claim 1, wherein rows of vertically adjacent microdevices from different cartridge substrates are arranged in an alternating manner, wherein the high side is vertically adjacent to the low side to reduce abrupt transitions caused by inhomogeneities of microdevices across each cartridge substrate.

16. The method of claim 1, wherein for a first group of microdevices associated with pixel pitch in the receiving substrate, there are different lateral and vertical pitches, gap regions, or interference regions between laterally and vertically adjacent groups of pixels.

17. The method of claim 16, wherein the spacing of the receiving substrate compensates for any mismatch between the pixel spacing and the microdevice spacing, ensuring that microdevices on the donor substrate or the first cartridge substrate do not interfere with pads in horizontally and vertically adjacent clusters, or existing microdevices on the receiving substrate.

18. The method of claim 17, wherein the gap region is defined by a distance from at least one side of the outer pad of the pixel to the far side of the outer pad at the opposite side of the pixel, or by a distance of at least N times the spacing of the pads, wherein N is the number of horizontally or vertically adjacent pads in the pixel, and wherein the length is the entire length of the cartridge.

19. The method of claim 1, wherein the plurality of microdevice groups form pixels from each array or collection of microdevices and are simultaneously mounted on the receiving substrate, and both the cartridge or the receiving substrate are moved relative to each other to align with subsequent plurality of pad clusters, and the mounting process is repeated until the cartridge is empty or the receiving substrate is filled.

20. The method of claim 1, wherein for a single microdevice or a group of microdevices, the microdevices prepared on the donor substrate prior to transfer to the cartridge use a support layer, wherein the microdevice spacing matches the spacing in the cartridge or is a multiple of the cartridge spacing.

21. The method of claim 1, wherein the microdevice is flipped, high-performance microdevices and low-performance microdevices are alternated on the inner side, and the edges are skewed to improve average uniformity, and wherein the performance of the microdevice alternates between high and low in both the adjacent horizontal block direction and the adjacent vertical block direction.

22. The method of claim 21, wherein the performance of the microdevice at the edge of the block is matched to that of the adjacent transferred block prior to transfer to the receiving substrate.

23. The method of claim 21, wherein two or more blocks are used to fill the blocks in the cassette or receiving substrate, and wherein the method of skewing or flipping is used to improve the average uniformity.

24. The method of claim 23, wherein a random or predefined pattern is used to fill the cartridge or receiving substrate with microdevices from more than one block.

25. The method of claim 23, wherein one or more blocks are derived from the same donor substrate or different donor substrates.

26. The method of claim 25, wherein the cartridge is filled from different blocks to eliminate non-uniformity found in any one block.

27. The method of claim 1, wherein, in the case of multiple cartridges, the positions of the cartridges are selected to eliminate overlap between the same region in the receiving substrate and a cartridge having the same microdevice during different transfer cycles.

28. The method of claim 27, wherein one of the cartridges is independent of the other cartridges.

29. The method of claim 27, wherein the alignment is performed independently, but other actions are synchronized, wherein, Furthermore, the substrate is moved to facilitate the transfer following the alignment.

30. The method of claim 27, wherein the alignment is performed independently, but other actions are synchronized, wherein, Furthermore, the cartridges move together to facilitate the transfer following the alignment.

31. The method of claim 27, wherein the alignment is performed independently, but other actions are synchronized, wherein, Furthermore, the cartridge and the substrate move together to facilitate the transfer following the alignment.

32. The method of claim 27, wherein the cartridge is pre-assembled with the frame or the substrate to hold the assembled cartridge, wherein the distance between cartridges is a multiple of the width or length of the cartridge, the multiple being a function of the movement step size toward different directions to fill the receiving substrate.

33. The method of claim 27, wherein the cartridge is aligned in one or both directions with independent control for applying pressure and temperature toward the receiving substrate.

34. The method of claim 27, wherein the cartridge is not aligned with a cartridge in at least one direction having independent control for applying pressure and temperature toward the receiving substrate.

35. The method of claim 27, wherein the cartridge has different means, and is therefore filled in different regions of the receiving substrate with different means, wherein, Furthermore, the relative position of the cartridge and the receiving substrate changes after each transfer cycle to fill different regions with all the required microdevices from the different cartridges.

36. The method of claim 27, wherein a plurality of arrays of cartridges are prepared, and microdevices are transferred from a first cartridge array to the receiving substrate, and the receiving substrate is moved to a next array of microdevices to fill the remaining area in the receiving substrate or to receive different devices.

37. The method of claim 27, wherein the cartridge is on a curved surface and the cyclic movement provides contact for transferring the microdevice into the receiving substrate.

38. A method for filling a receiving substrate, the method comprising the following steps: Multiple microdevices are fabricated on one or more donor substrates; The plurality of microdevices are transferred from one or more donor substrates to a cartridge substrate, wherein the cartridge contains three different types of microdevices and spare microdevices, the plurality of microdevices are arranged in an array and multiple sets of microdevices spaced apart on the cartridge substrate by gap regions, and wherein the gap regions are configured to prevent interference with non-contact pads on the receiving substrate during the transfer of one or more sets of microdevices to corresponding contact pads on the receiving substrate. One or more groups of microdevices are selected in the cartridge substrate for transfer to the receiving substrate, wherein the number of defective microdevices in the selected one or more groups of microdevices is less than a set threshold. and The selected microdevice group on the cartridge substrate is aligned and transferred to the corresponding contact pad on the receiving substrate.

39. The method of claim 38, wherein the number of defective microdevices are identified and corrected before or after transfer to the receiving substrate.

40. The method of claim 39, wherein the defective microdevice is corrected by one of the following methods: repairing, replacing, or removing the defective microdevice from the cartridge substrate.

41. The method of claim 40, wherein the defective microdevice is replaced with the spare microdevice on the cartridge substrate.

42. The method of claim 38, wherein the cartridge substrate comprises the plurality of microdevices of different types, the different types of microdevices including red microdevices, blue microdevices, or green microdevices.

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