CN113241315A

CN113241315A - Transfer tool and transfer method

Info

Publication number: CN113241315A
Application number: CN202110509739.5A
Authority: CN
Inventors: 萧博唐
Original assignee: AU Optronics Corp
Current assignee: AU Optronics Corp
Priority date: 2020-11-16
Filing date: 2021-05-11
Publication date: 2021-08-10
Anticipated expiration: 2041-05-11
Also published as: TW202221820A; TWI754454B; CN113241315B

Abstract

A transfer tool and a transfer method, the transfer tool includes a substrate, an array of active heating elements, and a picking member. The active heating element array comprises a plurality of heating units which are arranged on the substrate in an array form, and each heating unit comprises a driving circuit and a heating element connected with the driving circuit. The picking member is disposed on the active heating element array and includes a picking surface. The pickup surface is provided with an inherent pickup force and a modulated pickup force that is less than the inherent pickup force in response to operation of the plurality of heating elements.

Description

Transfer tool and transfer method

Technical Field

The invention relates to a transfer tool and a transfer method.

Background

During processing, it is often necessary to employ transfer techniques to transfer a workpiece to a target location or target substrate. For example, in the fabrication of led display devices, a large number of leds are required to be transferred from a source substrate to a target substrate. In some processes, Polydimethylsiloxane (PDMS) is used as a carrier for transferring leds, and the leds are transferred to a target substrate by using the van der waals force between the carrier and the leds. However, this method lacks selectivity, and all the leds contacted by the carrier are transferred. When the source substrate has damaged or bad leds, the out-of-specification leds may be transferred to the target substrate, which may result in the need to repair or replace the leds on the target substrate, thereby significantly increasing the cost and time of the process. Therefore, a need exists for a selective transfer tool and method.

Disclosure of Invention

The invention provides a transfer tool and a transfer method, which have the function of selecting a workpiece to be transferred and reduce the cost and time of the process.

According to one embodiment of the present invention, a transfer tool is provided that includes a substrate, an array of active heating elements, and a picker. The active heating element array comprises a plurality of heating units which are arranged on the substrate in an array form, and each heating unit comprises a driving circuit and a heating element connected with the driving circuit. The picking member is disposed on the active heating element array and includes a picking surface. The pickup surface is provided with an inherent pickup force and a modulated pickup force that is less than the inherent pickup force in response to operation of the plurality of heating elements.

According to another embodiment of the present invention, a transfer method is provided that includes providing a transfer tool including a substrate, an array of active heating elements, and a picking member. The active heating element array comprises a plurality of heating units which are arranged on the substrate in an array form, and each heating unit comprises a driving circuit and a heating element connected with the driving circuit. The picking member is disposed on the active heating element array and includes a picking surface. The transfer method further includes causing at least a portion of the pickface to pick up the at least one workpiece with an inherent pickforce, wherein the at least a portion of the pickface corresponds to the at least one heating element; and energizing the heating element of the at least one heating unit using the drive circuit of the at least one heating unit such that at least a portion of the pickup surface contacting the at least one workpiece has a modulated pickup force that is less than the intrinsic pickup force.

In view of the above, a transfer tool provided according to an embodiment of the present invention provides a driving circuit in each heating unit of an active heating element array. The picking force between the picking surface of the picking piece and the workpiece to be picked and released (transferred) is controlled by each driving circuit, so that the transfer tool can select whether to pick or release the corresponding workpiece or not by the picking force, and the aim of selectively picking and releasing (transferring) the workpiece is fulfilled. According to another embodiment of the present invention, a transfer method is provided, which uses the above-mentioned transfer tool to select a workpiece to be picked and released (transferred), picks the workpiece with an inherent picking force, and releases the workpiece with a modulated picking force, thereby selectively picking and releasing (transferring) the workpiece.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1A shows a top view of a transfer tool according to an embodiment of the present invention.

FIG. 1B shows a cross-sectional view of the transfer tool shown in FIG. 1A along line AA'.

Fig. 2A shows a schematic configuration of a heating unit according to an embodiment of the present invention.

Fig. 2B illustrates a top view of the driving circuit of the heating unit illustrated in fig. 2A.

Fig. 2C shows a top view of the heating unit shown in fig. 2A.

Fig. 2D shows a cross-section of the heating unit shown in fig. 2C along the line BB'.

Fig. 2E shows a cross-section of the heating unit shown in fig. 2C along the line CC'.

FIG. 3A shows a top view of a heating unit according to an embodiment of the invention.

Fig. 3B shows a cross-sectional view of the heating unit shown in fig. 3A along the line DD'.

FIG. 4A shows a cross-sectional view of a transfer tool according to one embodiment of the present invention.

Fig. 4B and 4C show top views of a part of the components of the transfer tool shown in fig. 4A.

Fig. 4D shows a cross-sectional view of a transfer tool according to an embodiment of the invention.

Fig. 5A shows the transfer tool and the work piece it picks up in a side view.

Fig. 5B shows a top view of the arrangement of the transfer tool and the workpiece shown in fig. 5A.

Fig. 6A shows the transfer tool and the work piece it picks up in a side view.

Fig. 6B shows a top view of the arrangement of the transfer tool and the workpiece shown in fig. 6A.

Fig. 7A to 7F are schematic diagrams illustrating a transfer method according to an embodiment of the present invention.

Fig. 7G shows an operation diagram of a partial structure of the transfer tool 700 corresponding to the workpiece 701A in fig. 7F.

Fig. 8A and 8B are schematic diagrams illustrating a transfer method according to an embodiment of the present invention.

Fig. 9A and 9B are schematic diagrams illustrating a transfer method according to an embodiment of the present invention.

Fig. 9C shows a flowchart of the transfer method of the embodiment shown in fig. 9A and 9B.

Description of reference numerals:

100. 400, 400', 500, 600, 700: transfer tool

101: substrate

102. 402, 502, 602, 702, 802, 902: active heating element array

103. 403, 403', 503, 603, 703, 803, 903: picking piece

102H, 202H, 302H, 402H: heating unit

103S, 403S, 803S, 903S: picking noodle

200. 300, and (2) 300: driving circuit

201: a first active element

202: second active element

203: capacitor with a capacitor element

204. 304: heating element

205. 305: insulating layer

206. 306: gate insulating layer

207: first power line

208: second power line

2011. 2021: a first electrode

2012. 2022: second electrode

2013. 2023: third electrode

403T, 503T, 603T, 703T: film(s)

403L, 403L', 503L, 603L, 703L: partition wall layer

403W: partition wall

403H, 403H': holes

403P, 803P: bump

403S, 503S, 603S, 703S: picking noodle

4041: protective layer

403CL, 403 CL', 503H, 703HA, 703HB 703 HC: closed cavity

504. 604, 605, 701A, 701B, 701C, 801, 901A, 901B: workpiece

800. 900: partial structure

704: first substrate

705: second substrate

903C1, 903C 2: thermally altered layer

903T1, 903T 2: heat conducting layer

903A: first pickup unit

903B: second pickup unit

903E: spacer section

S901, S902, S903, S904, S905: step (ii) of

AS1, AS 2: active layer

DL: data line

D1: amount of deformation

H1: height

H2, H3: depth of field

M1: metal layer

SL: scanning line

R1: radius of

r: direction of rotation

T1, T2: thickness of

W1, W2: width of

z: direction of rotation

Detailed Description

Referring to fig. 1A and 1B, fig. 1A shows a top view of a transfer tool according to an embodiment of the invention, and fig. 1B shows a cross-sectional view of the transfer tool shown in fig. 1A along line AA'. In fig. 1A and 1B, a transfer tool 100 includes a substrate 101, an array of active heating elements 102, and a picker 103. The active heating element array 102 includes a plurality of heating units 102H, the heating units 102H are arranged on the substrate 101 in an array, and each heating unit 102H includes a driving circuit and a heating element (not shown in fig. 1A and 1B) connected to the driving circuit. The picking member 103 is disposed on the active heating element array 102 and includes a picking surface 103S. As shown in fig. 1B, different regions of the pickoff surface 103S correspond to different heating elements 102H, such that different regions of the pickoff surface 103S are provided with different picking forces in response to operation of the corresponding heating elements 102H. When the driving circuit in the heating unit 102H corresponding to the picking surface 103S does not activate the heating member in the heating unit 102H, the picking surface 103S has an inherent picking force. When the driving circuit in the heating unit 102H corresponding to the pickup surface 103S enables the heating member in the heating unit 102H, the pickup surface 103S has a modulated pickup force smaller than the intrinsic pickup force.

Specifically, the transfer tool 100 of fig. 1A and 1B may contact and transfer a workpiece (not shown), according to one embodiment of the present invention. In some embodiments, the pick surface 103S may contact the workpiece to be transferred with a van der waals force. By the operation of the drive circuit and the heating member in the heating unit 102H described above, the area of the pickup surface 103S contacting the workpiece can be changed, thereby changing the strength of adhesion of the pickup surface 103S to the workpiece. In other embodiments, by the operation of the driving circuit and the heating member in the heating unit 102H described above, the area of the pickup surface 103S contacting the workpiece may not be changed but the viscosity of the pickup surface 103S may be changed, thereby changing the strength of adhesion of the pickup surface 103S to the workpiece. In this manner, the transfer tool 100 can adjust the adhesion force with the workpiece to achieve picking up the workpiece, releasing the workpiece, or other operations.

Referring to fig. 2A to 2E, fig. 2A shows a schematic circuit diagram of a heating unit according to an embodiment of the present invention, fig. 2B shows a top view of a driving circuit of the heating unit shown in fig. 2A, fig. 2C shows a top view of the heating unit shown in fig. 2A, fig. 2D shows a cross-sectional view of the heating unit shown in fig. 2C along a line BB ', and fig. 2E shows a cross-sectional view of the heating unit shown in fig. 2C along a line CC'.

In the embodiment shown in fig. 2A to 2E, the heating unit 202H includes a driving circuit 200 and a heating member 204. The driving circuit 200 includes a first active device 201, a second active device 202, and a capacitor 203, wherein the first active device 201 is connected between the second active device 202 and the heating element 204. In the embodiment, the driving circuit 200 has a structure of 2T1C (two tfts and one capacitor), but the invention is not limited thereto. In other embodiments, the driving circuit 200 may have other numbers of transistors than two, or other numbers of capacitors than one, and the driving circuit 200 may also have other elements than the thin film transistors and the capacitors.

The driving circuit 200 further includes a scan line SL, a data line DL, a first power line 207 and a second power line 208, wherein the first power line 207 provides a voltage VDD, and the second power line 208 provides a voltage VSS. The first active device 201 includes an active layer AS1, a first electrode 2011, a second electrode 2012, and a third electrode 2013. The gate insulating layer 206 is disposed between the active layer AS1 of the first active device 201 and the first electrode 2011 to insulate the two. The second active device 202 includes an active layer AS2, a first electrode 2021, a second electrode 2022, and a third electrode 2023. The gate insulating layer 206 is disposed between the active layer AS2 of the second active device 202 and the first electrode 2021 to insulate the two. The first electrode 2021 of the second active device 202 is electrically connected to the scan line SL. The second electrode 2022 of the second active device 202 is electrically connected to the data line DL. The third electrode 2023 of the second active device 202 is electrically connected to the first electrode 2011 of the first active device 201 through the metal layer M1. The second electrode 2012 of the first active device 201 is electrically connected to the first power line 207. The third electrode 2013 of the first active device 201 is connected to the heating element 204. The insulating layer 205 is disposed between the first active device 201 and the second active device 202 and the heating element 204.

After the first electrode 2021 of the second active device 202 receives a scan signal with an enable level from the scan line SL, the second electrode 2022 and the third electrode 2023 can be conducted through the active layer AS2, so AS to selectively transmit the data voltage from the data line DL to the first electrode 2011 of the first active device 201. The capacitor 203 is a storage capacitor, one end of the capacitor 203 is electrically connected between the first electrode 2011 and the second electrode 2012 of the first active device 201, and the other end is connected to the voltage VDD to reduce the voltage drift of the first electrode 2011 of the first active device 201. The voltage across the capacitor 203 corresponds to the conduction level of the first active device 201 and determines the current flowing through the first active device 201 and the heating element 204. The heating element 204 may be a heating wire, the temperature of which is controlled by controlling the current flowing through the heating element 204.

Referring to fig. 3A and 3B, fig. 3A shows a top view of a heating unit according to an embodiment of the present invention, and fig. 3B shows a cross-sectional view of the heating unit shown in fig. 3A along line DD'. It should be noted that the present embodiment follows the element numbers and partial contents of the embodiment shown in fig. 2A to 2E, wherein the same numbers are used to indicate the same or similar elements, and the description of the same technical contents is omitted. For the description of the omitted parts, reference may be made to the foregoing embodiments, and the description will not be repeated.

In the present embodiment, the heating unit 302H includes a driving circuit 300 and a heating member 304. The driving circuit 300 includes a first active device 201, a second active device 202, a capacitor 203, a scan line SL, a data line DL, a first power line 207, and a second power line 208, and the connection manner between the above components may be similar to the components included in the driving circuit 200 in the above embodiments, which is not described herein. The first active element 201 is connected between the second active element 202 and the heating element 304. The gate insulating layer 306 is disposed between the active layer AS1 of the first active device 201 and the first electrode 2011 to insulate the two. The insulating layer 305 is disposed on the first active device 201, the second active device 202, and the heating element 204. Compared to the heating element 204 shown in fig. 2C disposed on the driving circuit 200, the heating element 304 shown in fig. 3A and the first active device 201 of the driving circuit 200 are disposed in the same layer. For example, the heating element 304 may be formed in the same layer as the second electrode 2012, the third electrode 2013, the data line DL, the second power line 208, and the like, and the heating element 304 may be directly connected to the third electrode 2013, but not limited thereto.

According to some embodiments of the present invention, the heating member 204 and the heating member 304 are heating wires, and are disposed in a meandering manner on a plane parallel to the substrate 101, and the thickness and distribution density of the heating wires at different positions of the plane may be different.

Referring to fig. 4A to 4C, fig. 4A shows a cross-sectional view of a transfer tool according to an embodiment of the present invention, and fig. 4B and 4C show top views of a part of the components of the transfer tool shown in fig. 4A. Fig. 4A may be regarded as a cross-sectional view shown along line EE' of fig. 4B. The transfer tool 400 includes a substrate 101, an array of active heating elements 402, a picking member 403, and a protective layer 4041, wherein the protective layer 4041 is disposed between the array of active heating elements 402 and the picking member 403. The active heating element array 402 includes a plurality of heating units 402H. In fig. 4C, 9 heating units are schematically shown, and these heating units 402H are arranged in a 3 × 3 array on the substrate 101, each heating unit 402H including a driving circuit and a heating member connected to the driving circuit. However, the invention is not limited thereto, and the active heating element array 402 of the transfer tool 400 may include m × n heating units 402H arranged in an m × n array on the substrate 101, where m and n are positive integers.

In the present embodiment, each heating unit 402H has the same constituent members and arrangement as the heating unit 202H in the above-described embodiment, but the present invention is not limited thereto. In some embodiments, each heating unit 402H has the same components and configuration as the heating unit 302H described above.

Pick-up member 403 includes a film 403T and a partition layer 403L, where partition layer 403L includes a plurality of partitions 403W and a plurality of cavities 403H defined by partitions 403W. The film 403T seals the voids 403H to form a plurality of enclosed cavities 403 CL. A closed cavity 403CL formed by a cavity 403H and a film 403T corresponds to a heating unit 402H, but is not limited thereto.

The film 403T includes at least one bump 403P, and a surface of the bump 403P forms a pickup surface 403S of the pickup element 403, as shown in fig. 4A and 4B. Each cavity 403H corresponds to 9 bumps 403P in each closed cavity 403CL formed by the film 403T, but the invention is not limited thereto. In other embodiments, each enclosed cavity 403CL may correspond to only one bump 403P, or to other numbers of bumps 403P. When each of the closed cavities 403CL corresponds to only one bump 403P, the geometric center of the vertical projection of the closed cavity 403CL on the substrate 101 may be aligned with the geometric center of the vertical projection of the bump 403P on the substrate 101. When a plurality of bumps 403P are corresponding to each enclosed cavity 403CL, the vertical projections of the bumps 403P on the substrate 101 may be symmetrically distributed with respect to the vertical projection of the corresponding enclosed cavity 403CL on the substrate 101. The film 403T may be a thermal deformation film or a thermal deformation film, and according to an embodiment of the present invention, the material of the film 403T may include Polydimethylsiloxane (PDMS).

Since each heating unit 402H has the same constituent components and configuration as the heating unit 202H described above, the driving circuit of each heating unit 402H has the same constituent components and configuration as the driving circuit 200 of the above embodiment. In other words, each heating unit 402H having a driving circuit can selectively transmit a data voltage from a data line (not shown in fig. 4C) to the first electrode of the first active element of the driving circuit therein, so as to pass a current through the heating member and increase the temperature of the heating member. In other words, the closed cavity 403CL corresponding to each heating unit 402H can be selectively heated by the heating members in the heating unit 402H therebelow. Since the film 403T may be a thermal deformation film or have thermal deterioration characteristics, when the closed cavity 403CL is heated by the heating element below the closed cavity 403CL, the film 403T on the closed cavity 403CL is deformed or deteriorated by the heat. The work can be transferred with the surface of the film 403T, i.e., the pickup surface 403S, by such deformation or deterioration. In particular, when the film 403T is undeformed or degenerated, the pickup surface 403S may provide an inherent pickup force; when the film 403T is deformed or deteriorated by heat, the pickup surface 403S can provide a modulated pickup force that is less than the inherent pickup force. The workpiece can be picked up by using the inherent picking force and released by using the modulated picking force, so that the purpose of transferring the workpiece is realized.

It should be noted that the width W2 of each partition wall 403W in the direction perpendicular to the normal line of the substrate 101 may be larger than the width W1 of each cavity 403H in this direction to prevent the enclosed cavity 403CL defined by each cavity 403H from being affected by the adjacent heating unit 402H. It should also be noted that the height H1 of each cavity 403H in the direction normal to the substrate 101 may be greater than the width W1 in the direction perpendicular to the normal to the substrate 101, so that the deformation of the film 403T in response to the heated enclosed cavity 403CL is more pronounced. That is, the cavity 403H may have a large aspect ratio.

Referring to FIG. 4D, a cross-sectional view of a transfer tool is shown, in accordance with one embodiment of the present invention. The transfer tool 400 'includes a substrate 101, an array of active heating elements 402, and a picker 403'. Pick-up 403 'includes film 403T and spacer layer 403L', where spacer layer 403L 'includes a plurality of holes 403H'. The film 403T seals the voids 403H 'to form a plurality of enclosed cavities 403 CL'. A closed cavity 403CL 'formed by a cavity 403H' and the film 403T corresponds to the heating unit 402H, but is not limited thereto.

The material of the partition layer 403L' is, for example, an organic insulating material, which is formed on the substrate 101 by coating and has a large thickness. The larger thickness of the partition 403L 'may be used to form the cavity 403H' in the embodiment shown in fig. 4D by a photolithography process. The depth H3 of the cavity 403H 'in the normal direction of the substrate 101 is smaller than the thickness T2 of the spacer layer 403L' in the normal direction of the substrate 101. However, in other embodiments, the cavity 403H 'may alternatively extend through the entire thickness of the partition wall layer 403L', such that the depth H3 of the cavity 403H 'in the normal direction of the substrate 101 is equal to the thickness T2 of the partition wall layer 403L' in the normal direction of the substrate 101.

Referring to fig. 5A and 5B, fig. 5A shows a transfer tool and a work piece picked up by the transfer tool in a side view, and fig. 5B shows a configuration relationship of the transfer tool and the work piece shown in fig. 5A in a top view. Fig. 5A can also be considered a side view along line FF' of fig. 5B. The transfer tool 500 includes a substrate 101, an array of active heating elements 502, and a picker 503. The active heating element array 502 includes a plurality of heating units disposed in an array in a layer structure designated 502. The multiple heating units of the transfer tool 500 may be implemented, for example, as one of the heating units in the embodiment shown in fig. 2A-3B. The pick-up member 503 includes a film 503T and a partition layer 503L. The film 503T includes a plurality of bumps, and the surfaces of the bumps constitute the pickup surface 503S. The workpiece 504 is picked up by the transfer tool 500 by the picking force provided by the picking surface 503S. In other words, when the picking surface 503S contacts the workpiece 504, the workpiece 504 can be at least temporarily attached to the picking surface 503S without being arbitrarily separated from the picking surface 503S, and is not permanently attached to the picking surface 503S. In the present embodiment, each of the closed cavities 503H defined by the partition layer 503L and the film 503T may correspond to one workpiece 504, but not limited thereto.

Referring to fig. 6A and 6B, fig. 6A shows a transfer tool and a work piece picked up by the transfer tool in a side view, and fig. 6B shows a configuration relationship of the transfer tool and the work piece shown in fig. 6A in a top view. FIG. 6A can also be considered a side view along line GG' of FIG. 6B. The transfer tool 600 includes a substrate 101, an array of active heating elements 602, and a picker 603. The active heating element array 602 includes a plurality of heating units disposed in an array in a layer structure indicated as 602. The multiple heating units of the transfer tool 600 may be implemented, for example, as one of the heating units in the embodiments shown in fig. 2A-3B. The pick-up member 603 includes a film 603T and a spacer layer 603L. The film 603T includes a plurality of bumps, and the surfaces of the bumps constitute a pickup surface 603S. The

workpieces

604 and 605 are picked up by the transfer tool 600 by the pick-up force provided by the pick-up surface 603S. In the present embodiment, the workpiece 604 corresponds to 4 closed cavities 603H defined by the partition 603L and the film 603T, and is picked up by the transfer tool 600; the workpiece 605 corresponds to 1 closed cavity 603H defined by the partition 603L and the film 603T, and is picked up by the transfer tool 600. In general, a single workpiece can be picked up by the picking surface 603S corresponding to one enclosed cavity 603H or a plurality of enclosed cavities 603H.

In the present embodiment, each enclosed cavity 603H corresponds to 4 bumps. However, the present invention is not limited thereto. In other embodiments, each cavity may correspond to only one bump, or a plurality of bumps, and is not limited to 4 bumps.

Referring to fig. 7A to 7F, fig. 7A to 7F illustrate a schematic view of a transfer method according to an embodiment of the present invention. Referring initially to fig. 7A, in the present embodiment, a transfer method includes providing a transfer tool 700, the transfer tool 700 including a substrate 101, an array of active heating elements 702, and a picker 703. The active heating element array 702 includes a plurality of heating units disposed in an array in a layer structure denoted as 702. The multiple heating units of the transfer tool 700 may be implemented, for example, as one of the heating units in the embodiments shown in fig. 2A-3B. The pick-up member 703 includes a film 703T and a partition layer 703L. The film 703T includes a plurality of bumps, and the surfaces of the bumps constitute the pickup surface 703S. The film 703T and the partition layer 703L constitute a plurality of closed cavities 703HA, 703HB, and 703 HC.

The transfer method according to this embodiment further includes causing at least a portion of the pickface 703S to pick up the at least one workpiece with an intrinsic pickforce and energizing the heating elements of the at least one heating unit using the drive circuitry of the at least one heating unit such that at least a portion of the pickface 703S contacting the at least one workpiece has a modulated pickforce that is less than the intrinsic pickforce. Specifically, referring to fig. 7A-7C, fig. 7A-7C illustrate a process of selectively picking up a plurality of

workpieces

701A, 701B, or 701C on a first substrate 704 with a transfer tool 700. In the present embodiment, the workpieces to be picked up are the

workpieces

701A and 701C, and the workpiece 701B is not picked up. Specifically, the transfer tool 700 is brought close to the

workpieces

701A, 701B, and 701C (in the process shown in fig. 7A to 7B), and the closed cavity 703HB corresponding to the workpiece 701B is heated by at least one heating unit provided in the layer structure 702, so that the air inside the closed cavity 703HB expands due to the temperature increase (in the process shown in fig. 7B to 7C), and a corresponding portion of the film 703T (in fig. 7C, the middle section of the film 703T) is deformed. Due to the above-described deformation, the area of the pickup surface 703S in contact with the workpiece 701B is smaller than that of the pickup surface 703S in contact with the

workpiece

701A or 701C, so that the pickup force (modulation pickup force) between the pickup surface 703S and the workpiece 701B in this portion is smaller, and therefore the workpiece 701B cannot be picked up by the transfer tool 700 as with the

workpieces

701A and 701C. In contrast, since the contact area between the pickup surface 703S and the

workpiece

701A or 701C is large and the pickup force (inherent pickup force) is large, the

workpieces

701A and 701C can be picked up by the transfer tool 700.

The transfer method according to this embodiment further includes releasing at least one workpiece on a second substrate using the pickface 703S with a modulated pickforce that is less than the intrinsic pickforce. Specifically, referring to fig. 7D to 7F, the

workpieces

701A and 701C picked up by the transfer tool 700 are released on the second substrate 705 through the process shown in fig. 7D to 7F. Specifically, the transfer tool 700 and the

workpieces

701A and 701C are placed close to the second substrate 705 (as shown in fig. 7D to 7E), the closed cavities 703HA and 703HC are heated by a plurality of heating units disposed in the layer structure 702, so that the air inside the two closed cavities expands due to the temperature rise, and the corresponding portions of the film 703T are deformed, so that the pick-up force between the

workpieces

701A and 701C and the film 703T is changed from the intrinsic pick-up force to a smaller pick-up force (modulated pick-up force), and when the transfer tool 700 moves away from the second substrate 705, the

workpieces

701A and 701C are released on the second substrate 705 (as shown in fig. 7E to 7F). It should be noted that the modulated pick force of the non-picking workpiece 701B and the modulated pick force of the releasing

workpieces

701A and 701C described above are both less than the intrinsic pick force, but the magnitudes of the two modulated pick forces may be different from each other. However, in some embodiments, the modulated pick force of the non-picking workpiece 701B and the modulated pick force of the releasing

workpieces

701A and 701C may be substantially the same. For example, the magnitude of the modulated pickup force can be adjusted and changed by the degree of heating of the enclosed cavity by the heating unit.

It should be noted that, as mentioned above, the plurality of heating units in the transfer tool 700 may be implemented by, for example, one of the heating units in the embodiment shown in fig. 2A to 3B, and each of the heating units in the embodiment shown in fig. 2A to 3B may control the on and off of the first active element 201 through the second active element 202 in the internal 2T1C structure, so as to determine whether the heating element of the heating unit heats the corresponding closed cavities 703HA, 703HB, and 703HC, thereby achieving the purpose of selectively picking up and releasing the

workpieces

701A, 701B, or 701C.

Referring to fig. 7G, there is shown an operational schematic diagram of a partial structure of the transfer tool 700 corresponding to the workpiece 701A in fig. 7F. Specifically, fig. 7G is a diagram illustrating a condition for releasing the workpiece 701A from the transfer tool 700 to the second substrate 705. In fig. 7G, the film 703T HAs a thickness T1, and the closed cavity 703HA HAs a radius R1 in a direction (R direction) perpendicular to the normal line of the substrate and a depth H2 in a direction (z direction) parallel to the normal line of the substrate. When the closed cavity 703HA shown in fig. 7G is heated by the corresponding heating unit, so that the film 703T is deformed, the deformation amount of the film 703T in the z direction is D1. If the deformation amount D1 of the film 703T and the radius R1 of the closed cavity 703HA satisfy the conditional expression D1/R1> 20%, the workpiece 701A can be detached from the film 703T. According to an embodiment of the present invention, if the thickness T1 of the film 703T is 20 micrometers, the depth H2 of the closed cavity 703HA is 100 micrometers, and the radius R1 of the closed cavity 703HA is 50 micrometers, the workpiece 701A can be detached from the film 703T when the deformation D1 of the film 703T in the z direction is greater than 10 micrometers.

Referring to fig. 8A and 8B, fig. 8A and 8B are schematic diagrams illustrating a transfer method according to an embodiment of the invention. In this embodiment, the transfer method includes providing a transfer tool. In fig. 8A and 8B, only a portion of the structure 800 of the transfer tool is shown, including the substrate 101, the array of active heating elements 802, and the picking member 803. At least one heating element is disposed in the active heating element array 802. The at least one heating unit may be implemented, for example, as one of the embodiments shown in fig. 2A to 3B. The pickup member 803 is a thermally deformable film and is provided with a plurality of bumps 803P, and the surfaces of these bumps 803P constitute a pickup surface 803S. According to the bookIn one embodiment, the material of the picking member 803 includes Polydimethylsiloxane (PDMS) having a thermal expansion coefficient of about 310 × 10^-6/℃。

In the present embodiment, the workpiece 801 is picked up by the picking force between the picking surface 803S and the workpiece 801, and the heating element of the heating unit is enabled by the driving circuit of at least one heating unit disposed in the active heating element array 802, so that the picking member 803 serving as the thermal deformation film is deformed to release the workpiece 801, thereby achieving the purpose of picking up and releasing the workpiece 801. The heating members of the heating unit may be intensively disposed near the axis of symmetry of the partial structure 800 in the normal direction of the substrate 101, so that the rising amplitude of the central portion thereof is more pronounced when the picking member 803 thermally expands.

Specifically, the transfer tool of the present embodiment is composed of a plurality of partial structures 800 arranged in an array, and the transfer tool of the present embodiment can also achieve the purpose of transferring a plurality of workpieces as shown in fig. 7A to 7F.

Referring to fig. 9A and 9B, fig. 9A and 9B are schematic diagrams illustrating a transfer method according to an embodiment of the invention. In this embodiment, the transfer method includes providing a transfer tool. In fig. 9A and 9B, only a portion of the structure 900 of the transfer tool is shown, including the substrate 101, the array of active heating elements 902, and the picker 903. The picking member 903 includes a first picking unit 903A, a second picking unit 903B, and a spacing portion 903E between the first and

second picking units

903A and 903B. At least two heating units (not shown) are disposed in the active heating element array 902 for respectively heating the first pickup unit 903A and the second pickup unit 903B. Each heating unit may be implemented, for example, as one of the embodiments shown in fig. 2A to 3B. The first pickup unit 903A includes a thermally conductive layer 903T1 and a thermally altered layer 903C1, the second pickup unit 903B includes a thermally conductive layer 903T2 and a thermally altered layer 903C2, and surfaces of the thermally altered layers 903C1 and 903C2 constitute a pickup surface 903S of the pickup 903. The heat conductive layers 903T1 and 903T2 are heat conductive and temperature resistant materials, and may be patterned structures formed by photolithography or etching. The first pickup unit 903A and the second pickup unit 903B are formed by coating thermally altered layers 903C1 and 903C2 on the bumps of the thermally conductive layers 903T1 and 903T2, respectively. In some embodiments, the spacer 903E between the first and

second pickup units

903A, 903B may have a thinner thickness to reduce thermal conduction between the first and

second pickup units

903A, 903B. In some embodiments, the spacer 903E between the first and

second pickup units

903A, 903B may be completely removed.

Referring to fig. 9C, a flow chart of the transfer method of the embodiment shown in fig. 9A and 9B is shown. In the present embodiment, the

workpieces

901A and 901B are picked up with the picking force between the picking surface 903S and the

workpieces

901A and 901B (step S901), and the heating elements of at least two heating units disposed in the active heating element array 902 are enabled by the driving circuits of the at least two heating units, so that the heat energy is conducted to the thermal deterioration layers 903C1 and 903C2 through the heat conductive layers 903T1 and 903T2, and the thermal deterioration layers 903C1 and 903C2 are thermally deteriorated or decomposed, thereby reducing the picking force between the thermal deterioration layers 903C1 and 903C2 and the

workpieces

901A and 901B (step S902), so as to release the

workpieces

901A and 901B (step S903), and achieve the purpose of picking up and releasing (transferring) the

workpieces

901A and 901B (step S904). In the present embodiment, after the

workpieces

901A and 901B are released due to the thermal deterioration layers 903C1 and 903C2 being thermally deteriorated or decomposed, the thermal deterioration layers 903C1 and 903C2 may be recoated (step S905), and the above process of picking up and releasing (transferring) other workpieces may be repeated.

Specifically, the transfer tool of the present embodiment is composed of a plurality of partial structures 900 arranged in an array structure, and the transfer of a plurality of workpieces as shown in fig. 7A to 7F can be achieved by using the transfer tool of the present embodiment.

In summary, the transfer tool according to an embodiment of the present invention includes a driving circuit in each heating unit of the active heating element array. The picking force between the picking surface of the picking piece and the workpiece to be picked and released (transferred) is controlled by each driving circuit, so that the transfer tool can select whether to pick or release the corresponding workpiece or not by the picking force, and the aim of selectively picking and releasing (transferring) the workpiece is fulfilled. According to another embodiment of the present invention, a transfer method is provided, which uses the above-mentioned transfer tool to select a workpiece to be picked and released (transferred), picks the workpiece with an inherent picking force, and releases the workpiece with a modulated picking force, thereby selectively picking and releasing (transferring) the workpiece.

Claims

1. A transfer tool, comprising:

a substrate;

an active heating element array comprising a plurality of heating units arranged in an array on the substrate, each heating unit comprising a driving circuit and a heating element connected to the driving circuit; and

a picking member disposed on the active heating element array and including a picking surface,

wherein the pickup surface is provided with an inherent pickup force and a modulated pickup force that is less than the inherent pickup force in response to operation of at least one of the heating elements.

2. The transfer tool of claim 1, wherein the picking member further comprises a film, and the film forms the picking surface.

3. The transfer tool of claim 2, wherein the pick further comprises a barrier layer disposed on the substrate, the barrier layer having a plurality of cavities, the film sealing the cavities to form a plurality of closed cavities.

4. The transfer tool of claim 3, wherein a depth of each cavity in a normal direction of the substrate is less than a thickness of the partition wall layer in the normal direction of the substrate.

5. The transfer tool of claim 3, wherein each cavity has a height in a direction normal to the substrate that is greater than its width in a direction perpendicular to the normal to the substrate.

6. The transfer tool of claim 3, wherein the partition layer has a plurality of partitions defining the cavities, and a thickness of each partition in a direction perpendicular to a normal of the substrate is greater than a width of each cavity in the direction.

7. The transfer tool of claim 2, wherein the film comprises at least one bump, and a surface of the at least one bump forms the pickup surface.

8. The transfer tool of claim 2, wherein the film is a heat deformable film.

9. The transfer tool of claim 2, wherein the film comprises polydimethylsiloxane.

10. The transfer tool of claim 1, wherein the pick-up further comprises a heat conductive layer disposed on the substrate, the heat conductive layer having a plurality of cavities, each cavity having a depth in a direction normal to the substrate that is less than a thickness of the heat conductive layer in the direction normal to the substrate.

11. The transfer tool of claim 1, wherein the picking member includes a thermally altered layer, and the thermally altered layer forms the picking surface.

12. The transfer tool of claim 1, wherein the drive circuit comprises a first active element, a second active element, and a capacitor, and the first active element is coupled between the second active element and the heating member.

13. The transfer tool of claim 12, wherein the heating element is disposed in a layer with the first active element.

14. The transfer tool of claim 1, wherein the heating member is a heating wire which is meanderly disposed on a plane parallel to the substrate, and the heating wire is different in thickness and distribution density at different positions of the plane.

15. The transfer tool of claim 1, further comprising an insulating layer disposed between the drive circuit and the heating element.

16. The transfer tool of claim 1, further comprising a protective layer disposed between the array of active heating elements and the picking member.

17. A method of transferring, comprising:

providing a transfer tool, the transfer tool comprising:

a substrate;

a picking member disposed on the array of active heating elements and including a picking surface having an inherent picking force; and

the drive circuit using at least one heating element enables the heating element of the at least one heating element such that at least a portion of the pickup surface has the intrinsic pickup force modulated to a modulated pickup force that is less than the intrinsic pickup force.

18. The transfer method of claim 17, further comprising:

enabling the at least one part of the picking surface to pick up at least one workpiece from a first substrate by the inherent picking force; and

the at least one workpiece is released from the at least one portion of the picking surface to a second substrate with the modulated picking force.

19. The transfer method of claim 17 further comprising contacting the at least one portion of the pickface with the modulated picking force to at least one workpiece and contacting at least another portion of the pickface with the intrinsic picking force to at least another workpiece.

20. The transfer method of claim 17, wherein the drive circuit comprises a first active element, a second active element, and a capacitor, the first active element being connected between the second active element and the heating element, and the method of energizing the heating element of the at least one heating unit comprises:

the second active device is used for controlling the first active device to be turned on and off.