WO2022185704A1

WO2022185704A1 - Transfer apparatus and transfer method

Info

Publication number: WO2022185704A1
Application number: PCT/JP2021/048986
Authority: WO
Inventors: 良勝柳川; 直也大倉
Original assignee: 株式会社ブイ・テクノロジー
Priority date: 2021-03-05
Filing date: 2021-12-28
Publication date: 2022-09-09
Also published as: TW202249141A; JP2022135730A; CN117043969A

Abstract

The present invention is a transfer apparatus for transferring electronic components to a transfer member and comprises: a first sticking device part 1 for sticking, to a light transmissive substrate S1 having a plurality of electronic components formed thereon, a first transfer member T1 in which the adhesive force thereof decreases due to ultraviolet light irradiation; a first transfer device part 2 for transferring the electronic components to one surface of the first transfer member by performing peeling via laser lift-off; an ultraviolet light irradiation device part 3 for decreasing the adhesive force of the first transfer member by irradiating the first transfer member with ultraviolet light in a state in which a treatment was performed to prevent exposure to oxygen; a second sticking device part 4 for sticking, to a substrate S2, a second transfer member T2 having a stronger adhesive force than the first transfer member in which the adhesive force thereof was decreased; a second transfer device part 5 for bonding together the first transfer member and second transfer member, and utilizing the difference in the adhesive forces thereof to peel the electronic components from the first transfer member and transfer the same to the second transfer member; and a control device part for controlling each part 1-5. The yield rate of the electronic components during transfer is thereby improved.

Description

Transfer device and transfer method

The present invention relates to transfer technology for electronic components such as micro LEDs (Light Emitting Diodes), and more particularly to a transfer apparatus and transfer method capable of improving the yield during transfer of electronic components.

Conventionally, a mounting method has been proposed in which a semiconductor chip made of a micro LED is mounted on a circuit board using a transfer technology (see Patent Document 1, for example). According to Patent Document 1, a first transfer process, an adhesive force reduction process, a second transfer process, and a mounting process are sequentially performed.

Specifically, in the first transfer step, first, a carrier substrate having a plurality of semiconductor chips and a first adhesive sheet are prepared. Then, in the first transfer step, the semiconductor chip is detached from the carrier substrate by irradiating the semiconductor chip with laser light, and the semiconductor chip is transferred to the first adhesive sheet.

Next, in the adhesive strength reduction step, the adhesive strength of the first adhesive sheet is reduced by heating the semiconductor chip and the first adhesive sheet. Further, in the second transfer step, one surface of the semiconductor chip is irradiated with a laser beam through the first adhesive sheet, whereby the semiconductor chip is peeled off from the first adhesive sheet and transferred to the second adhesive sheet. be transcribed to Then, in the mounting step, the semiconductor chip transferred to the second adhesive sheet and the circuit board are thermally compressed to mount the semiconductor chip on the circuit board.

Here, in the adhesive strength reduction step, in detail, a method of reducing the adhesive strength of the adhesive film by heating the adhesive film of the first adhesive sheet to a predetermined temperature is adopted. In addition, in Patent Document 1, when an adhesive film whose adhesive strength changes by irradiation with UV (Ultra Violet) light is used, a method of reducing adhesive strength by irradiating UV light toward the adhesive film is disclosed. It states that it can be done.

Japanese Unexamined Patent Application Publication No. 2019-114660

However, Patent Document 1 does not disclose specific details other than the above when an adhesive film whose adhesive strength changes by irradiation with UV light (ultraviolet rays) is used. On the other hand, when we independently conducted an experiment on the transfer of micro LEDs as an electronic component using a transfer material whose adhesive strength is reduced by ultraviolet irradiation (for example, a UV peeling tape), we found that the micro LEDs were not transferred normally. was found to occur.

In view of this, the present invention provides a transfer apparatus and a transfer method capable of improving the yield at the time of transfer of electronic parts in the case of adopting a transfer member whose adhesive strength is reduced by ultraviolet irradiation, in order to deal with such problems. intended to provide

In order to achieve the above object, a first invention provides a transfer device for transferring electronic components to a transfer member, which is a light transmissive transfer device having a plurality of electronic components formed on one surface according to a predetermined arrangement. a first attaching device for attaching a first transfer member whose adhesive strength is reduced by ultraviolet irradiation to a substrate; a first transfer device portion for transferring the electronic parts onto one surface of a transfer member; and the first transfer member to which the electronic parts have been transferred is subjected to a treatment to prevent exposure to oxygen, and then exposed to ultraviolet rays. to the first transfer member to reduce the adhesive strength of the first transfer member; A second pasting device unit for pasting a second transfer member having stronger adhesion than the transfer member, and the first transfer member and the second transfer member are pasted together to utilize the difference in adhesion. a second transfer device section for separating the electronic component from the first transfer member and transferring the electronic component to the second transfer member; the first pasting device section; the first transfer device section; A control device section for controlling the ultraviolet irradiation device section, the second pasting device section, and the second transfer device section.

In order to achieve the above object, a second invention provides a transfer method for transferring electronic parts to a transfer member, comprising a light transmissive transfer member having a plurality of electronic parts formed on one surface according to a predetermined arrangement. A step of attaching a first transfer member whose adhesive strength is reduced by ultraviolet irradiation to a substrate, and peeling off the electronic component from the light transmissive substrate via laser lift-off, thereby removing one side of the first transfer member. transferring the electronic component onto a surface; and irradiating the first transfer member onto which the electronic component has been transferred with ultraviolet rays in a state where the first transfer member is treated to prevent exposure to oxygen, a step of irradiating an ultraviolet ray to reduce the adhesive strength of the first transfer member; and a second transfer member having stronger adhesive strength than the first transfer member having the reduced adhesive strength to the substrate for transferring the electronic component. and sticking the first transfer member and the second transfer member together, using the difference in adhesive strength to separate the electronic component from the first transfer member, and and transferring to a second transfer member.

According to the transfer device according to the first aspect of the invention, the first transfer member to which the electronic component has been transferred is irradiated with ultraviolet rays in a state in which the first transfer member is treated to prevent exposure to oxygen. In addition, since the adhesive strength of the first transfer member is lowered, the transfer yield of the electronic parts can be improved without being adversely affected by the exposure to oxygen.

According to the transfer method according to the second aspect of the invention, in the step of reducing the adhesion of the first transfer member, the first transfer member is irradiated with the ultraviolet rays after being treated to prevent exposure to oxygen. Since the adhesive strength of the first transfer member is reduced by reducing the adhesive strength of the first transfer member, it is not adversely affected by exposure to oxygen. By bonding the transfer member and the second transfer member together, the yield at the time of transfer of the electronic component can be improved.

1 is a block diagram showing a schematic configuration of an embodiment of a transfer device according to the present invention; FIG. It is explanatory drawing which shows the structure of the light transmissive board|substrate with which the electronic component was formed. FIG. 2 is an explanatory diagram showing the structure of a light-transmissive substrate, where (a) is a partially enlarged plan view and (b) is a cross-sectional view taken along the line AA of (a). It is explanatory drawing which shows the structure of the 1st sticking apparatus part. 4 is a schematic cross-sectional view showing the configuration of a first transfer member; FIG. 4 is an explanatory diagram showing the configuration of an LLO section in the first transfer section; FIG. FIG. 4 is an explanatory view showing the configuration of a wafer peeling section in the first transfer section; It is explanatory drawing which shows the structure of an ultraviolet irradiation device part. It is explanatory drawing which shows the structure of a 2nd sticking apparatus part. FIG. 4 is a schematic cross-sectional view showing a second transfer member; It is explanatory drawing which shows the structure of a bonding part. FIG. 4 is an explanatory diagram showing the configuration of a transfer member peeling section; FIG. 2 is a block diagram showing a hardware configuration of a control device unit shown in FIG. 1; FIG. 3 is an explanatory diagram showing control by a control device section of the transfer device shown in FIG. 1; FIG. 4 is a flow chart showing the processing of one embodiment of the transfer method according to the present invention; It is explanatory drawing which shows the process of one embodiment of the transfer method by this invention by the change of the top view of a to-be-processed object. It is explanatory drawing which shows the process of one embodiment of the transfer method by this invention by the change of the end view of a workpiece. It is explanatory drawing which shows operation|movement of a 1st sticking apparatus part by a side view. It is explanatory drawing which shows operation|movement of a 1st sticking apparatus part by planar view. It is explanatory drawing which shows operation|movement of a wafer peeling part. FIG. 16 is a flowchart showing the details of the ultraviolet irradiation step shown in FIG. 15; FIG. It is explanatory drawing which shows operation|movement of an ultraviolet irradiation device part. It is explanatory drawing which shows operation|movement of a 2nd sticking apparatus part. It is explanatory drawing which shows operation|movement of a bonding part. It is explanatory drawing which shows operation|movement of a peeling part. FIG. 16 is a flow chart showing a process when a red micro LED is used in the second transfer step shown in FIG. 15; FIG. FIG. 4 is an explanatory view showing the configuration of a second carrier to which a red micro LED is transferred, (a) being a partially enlarged plan view, and (b) being a cross-sectional view taken along line CC of (a). FIG. 16 is a flow chart showing a process when green micro LEDs are used in the second transfer step shown in FIG. 15; FIG. FIG. 4 is an explanatory view showing the configuration of a second carrier to which a green micro LED is further transferred, (a) being a partially enlarged plan view, and (b) being a cross-sectional view taken along line CC of (a). 16A and 16B are explanatory views showing a second transfer step shown in FIG. 15; FIG. FIG. 16 is a flow chart showing a process when a blue micro LED is used in the second transfer step shown in FIG. 15; FIG. FIG. 4 is an explanatory view showing the configuration of a second carrier to which a blue micro LED is further transferred, (a) being a partially enlarged plan view, and (b) being a cross-sectional view taken along line CC of (a). FIG. 4 is a flow chart showing a first modification of the transfer method according to the invention; FIG. FIG. 4 is an explanatory view showing the configuration of a second carrier to which UV-LEDs are transferred, (a) being a partially enlarged plan view, and (b) being a cross-sectional view taken along line DD of (a).

Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a transfer device according to the present invention. The transfer device of the present invention is a transfer device that transfers electronic components to a transfer member, and is used to manufacture substrates for transferring electronic components. This substrate for transferring electronic components has electronic components formed on one side thereof, and is used to transfer and mount the electronic components on, for example, a circuit board. The transfer device shown in FIG. , and a control unit 6 .

The first sticking device section 1 applies a first adhesive whose adhesive strength is reduced by ultraviolet irradiation to a light-transmitting substrate S1 (see FIG. 2) having a plurality of electronic components formed in accordance with a predetermined arrangement on one surface. A transfer member T1 (see FIG. 5) is attached. Electronic components used in the transfer device according to the present invention may be electronic components formed on a wafer in a semiconductor process. ) micro LED. The first transfer member T1 is a UV peeling tape whose adhesive strength is reduced by ultraviolet irradiation. Further, the circuit board is used for manufacturing a micro LED display, for example, and is a circuit board for causing the micro LED to emit light.

FIG. 2 is a plan view of a light transmissive substrate S1 having electronic components formed on one surface (hereinafter referred to as "surface"). 3A and 3B are explanatory diagrams showing the configuration of the light-transmitting substrate S1, in which FIG. 3A is a partially enlarged plan view and FIG. 3B is a sectional view taken along line AA of FIG. The light-transmissive substrate S1 (hereinafter referred to as “substrate S1”) is a substrate that transmits laser light used for laser lift-off, which will be described later, and is, for example, a sapphire substrate.

FIG. 3(a) is, in detail, an enlarged plan view of a region in which four red micro LEDs 11a are further arranged in the region surrounded by R1 shown in FIG. On the substrate S1, for example, red micro LEDs 11a are formed in a matrix on the surface of the substrate S1 according to a predetermined arrangement. Here, the predetermined arrangement is, for example, an arrangement corresponding to the pixel arrangement of the RGB micro LED display. For convenience of explanation, the micro LEDs 11a formed in a matrix on the surface of the substrate S1 will be referred to as an LED wafer S11. In FIG. 3A, as an example, the micro LEDs 11a are arranged in an arrangement pattern corresponding to full-color display, the arrangement pitch in the row direction is P1, and the arrangement pitch in the column direction is P1. The pitch interval is P2.

Further, the micro LED 11a includes a pair of

electrode portions

111 and 112 and an LED body portion 110, as shown in FIG. 3(a). The pair of

electrode portions

111 and 112 is, for example, an electrode pad that enables electricity to flow from the circuit board to the micro LED 11a. The electrode portion 111 is an n-side electrode pad (cathode electrode), and the electrode portion 112 is a p-side electrode pad. (anode electrode).

In FIG. 3, the case where the red micro LED 11a is formed on the surface of the substrate S1 has been described, but as will be described later, a green micro LED 11b (see FIG. 29) and a blue micro LED 11c (see FIG. 32) are also used. do. In the following description of the device configuration, the red micro-LED 11a will be mainly described as a representative of the three-color micro-LEDs. In FIG. 3, the micro LED 11a may be selected within a range of, for example, width (15 to 20 μm)×length (30 to 45 μm). Also, the thickness of the micro LED 11a may be selected within a range of, for example, about 5 to 20 μm.

FIG. 4 is an explanatory diagram showing the configuration of the first sticking device section 1. As shown in FIG. Specifically, the first sticking device section 1 shown in FIG. 4 includes a first transfer member (UV peeling tape) T1 conveyed by a so-called roll-to-roll method, and a micro LED 11a shown in FIG. This is an apparatus for attaching to the formed substrate S1 (LED wafer S11). The first pasting device section 1 includes a stage mechanism 12, a suction stage 13, a pressure roller 14, a delivery mechanism 15, a tape cutter 16, a guide roller 17, a winding mechanism 18, a fixing ring 19, and a first transfer member. T1 is provided.

FIG. 5 is a schematic cross-sectional view showing the configuration of the first transfer member T1. The first transfer member T1 has characteristics such that it is flexible and has a strong adhesive force before being irradiated with ultraviolet rays, and is hardened after being irradiated with ultraviolet rays to reduce the adhesive force. The first transfer member T1 (hereinafter sometimes simply referred to as “transfer member T1”) is provided in the order of the base film T11 and the adhesive layer T12 from the bottom layer. Furthermore, a detachable protective film F1 that can be repeatedly attached is attached to the upper layer of the transfer member T1. As the transfer member T1 and protective film F1, for example, ELP UB-3103AC (manufactured by Nitto Denko Corporation) is used. The base film T11 and the protective film F1 are made of polyethylene terephthalate (PET). The thickness of this base film T11 is about 50 μm.

The adhesive layer T12 has components such as acrylic polymers and oligomers (polymers in which a relatively small number of monomers are bonded). The thickness of this adhesive layer T12 is about 50 μm. The adhesive layer T12 also contains a photopolymerization initiator that initiates photopolymerization by irradiation with ultraviolet rays. In the adhesive layer T12, the components of the adhesive layer T12 are photopolymerized by irradiation with ultraviolet rays, the flexibility of the adhesive layer T12 is lost, and the adhesive force is lowered.

As photopolymerization initiators, photoradical polymerization initiators that generate radicals, photopolymerization initiators that generate acids, and photopolymerization initiators that generate bases are known. As the photopolymerization initiator, it is preferable to use a photoradical polymerization initiator having high sensitivity to ultraviolet rays. Since oxygen easily captures radicals, the effect of the present invention is high. Therefore, the first transfer member T1 is preferably a transfer member containing a photoradical polymerization initiator.

The protective film F1 is a laminate film (also referred to as a "separator") for protecting the adhesive layer T12, and is peeled off from the first transfer member T1 during use. The thickness of this protective film F1 is about 40 μm.

In the first sticking device section 1 shown in FIG. 4, a stage mechanism 12 moves up and down a suction stage 13, and the suction stage 13 suctions an LED wafer S11 placed inside a fixing ring 19. and support it. For convenience of explanation, the fixing ring 19 and the LED wafer S11 are shown in end views so that the inside of the ring of the fixing ring 19 can be seen on the drawing (the same applies hereinafter). The pressure roller 14 moves in one axial direction while rotating to press the transfer member T1 onto the LED wafer S11 to adhere it.

The delivery mechanism 15 sequentially delivers an elongated transfer member T1 that can be wound into a roll. Specifically, the delivery mechanism 15 transports the transfer member T1 in a fixed direction continuously or intermittently, for example, by the roll-to-roll method described above. , 15c, a tension roller 15d, and a first take-up roller 15e. The delivery mechanism 15 is provided with a plurality of support rollers (not shown) for preventing the transfer member T1 from being misaligned, meandering, or bent while being conveyed.

The first delivery roller 15a is provided on the front side of the transfer member T1 in the transport direction D, and rotates to deliver the wound transfer member T1. In the transfer member T1, the reason why the protective film F1 is attached on the adhesive layer T12 is to prevent contamination such as dust.

The peeling

rollers

15b and 15c peel off the protective film F1 from the transfer member T1 conveyed along the conveying direction D. At this time, the protective film F1 is mechanically separated from the transfer member T1 by the rotating action of the

separation rollers

15b and 15c. The first take-up roller 15e takes up the peeled protective film F1 via the first tension roller 15d. The first tension roller 15d prevents loosening of the peeled protective film F1. In addition, when the leading edge of the protective film F1 is taken up by the peeling

rollers

15b and 15c, a mechanism (not shown) that causes the leading edge of the protective film F1 to be taken up by the first tension roller 15d and the first take-up roller 15e. ) is provided.

The tape cutter 16 cuts around the fixing ring 19 for supporting the transfer member T1 after the transfer member T1 is attached to the LED wafer S11. As a result, the transfer member T1 is finally cut out in a circular shape and attached to the LED wafer S11, so that the transfer member T1 itself is not interrupted. The winding mechanism 18 winds the transfer member T1 that has passed the guide roller 17 into a roll.

As described above, the first pasting device section 1 continuously cuts the transfer member T1 conveyed by a so-called roll-to-roll method, and attaches the cut transfer member to the surface of the substrate S1 of the LED wafer S11. It is characterized by attaching T1.

Next, the first transfer device section 2 will be described. The first transfer device section 2 transfers electronic components (for example, micro LEDs 11a) from the substrate S1 to one surface of the transfer member T1 by peeling the electronic components (eg, micro LED 11a) from the substrate S1 via laser lift-off. The first transfer device section 2 includes an LLO (Laser Lift Off) section 21 and a wafer peeling section 22 .

FIG. 6 is an explanatory diagram showing the configuration of the LLO section 21 in the first transfer device section 2. As shown in FIG. FIG. 7 is an explanatory diagram showing the configuration of the wafer peeling section 22 in the first transfer device section 2. As shown in FIG.

The LLO unit 21 shown in FIG. 6 is a device that performs laser lift-off, and includes a support unit 21a, a laser device 21b, a uniform optical system 21c, a slit 21d, a reduction optical system 21e, a lens 21f,

alignment cameras

21g and 21h, and a stage 21i. Prepare.

The support portion 21a supports the laser device 21b and uniform optical system 21c. The laser device 21b emits a pulsed laser beam L by laser oscillation, and includes a laser head and a laser power supply controller. The laser device 21b is, for example, a laser whose pulse width is shortened to the picosecond level, and is a YAG (Yttrium Aluminum Garnet) laser with a wavelength in the deep ultraviolet region of 257 nm, 263 nm, or 266 nm (fourth harmonic). is used to emit laser light L. Here, the laser processing energy is 250 mJ/cm ^{2 for the red micro LED 11a, and 400 mJ/cm 2} ^for the green micro LED 11b and blue micro LED 11c. The number of shots is one shot. The uniform optical system 21c mainly makes the laser beam into a uniform intensity distribution. The uniform optical system 21c is provided with a mirror M for changing the optical path in FIG.

The laser light L enters the slit 21d through the uniform optical system 21c. The slit 21d is a projection mask that shapes the laser beam into a predetermined shape. Then, the laser light L that has passed through the light-transmitting region of the slit 21d is reduced and projected through the reduction optical system 21e and guided to the irradiation region on the back surface of the substrate S1. The reduction optical system 21e reduces and projects the laser light L that has passed through the slit 21d onto an irradiation area on the back surface of the substrate S1 via a lens 21f.

Alignment cameras

21 g and 21 h are for adjusting the position of the LED wafer S 11 placed on the stage 21 .

Laser lift-off is a means of exfoliating each micro LED 11a from the substrate S1 by irradiating the micro LEDs 11a formed on the front surface of the substrate S1 with a laser beam L generated by pulse oscillation from the back surface of the substrate S1 in the LED wafer S11. be. Specifically, in the laser lift-off, the micro LED 11a is peeled off from the substrate S1 in the interface region by, for example, ablation by focusing and irradiating the laser light L on the interface region (for example, the peeling layer) where the peeling is desired. be done. It should be noted that peeling the micro LED 11a from the substrate S1 is synonymous with peeling the micro LED 11a from the substrate S1. In the laser lift-off described above, peeling includes not only a completely separated state but also a state of being easily peeled off.

Here, for convenience of explanation, FIG. 6 shows a state in which the first transfer member T1 is attached to the LED wafer S11 via the micro LEDs 11a. Actually, as described above, the thickness of the micro LED 11a is on the order of microns, so that the first transfer member T1 is also attached to the substrate S1 of the LED wafer S11 in a general view.

The wafer peeling unit 22 shown in FIG. 7 is a device for removing the substrate S1 after the laser lift-off process, and includes a suction head 22a, a suction stage 22b, and a push-up stage 22c. The wafer peeling unit 22 first contacts and sucks the LED wafer S11 attached to the transfer member T1 placed on the suction stage 22b with the suction head 22a. Next, in the wafer peeling unit 22, the suction head 22a raises the LED wafer S11 while the thrust stage 22c slightly lifts the LED wafer S11 from below. Then, the micro LED 11a is peeled and separated from the substrate S1, and the micro LED 11a is transferred to the transfer member T1. Details will be described later with reference to FIG. 20 .

Therefore, in the present embodiment, the laser lift-off process is characterized by adjusting the control parameters such as irradiation energy to perform peeling so that the micro LED 11a can be easily peeled off from the substrate S1. This is to facilitate collection of the used substrate S1 after the micro LEDs 11a have been transferred from the LED wafer S11 to the transfer member T1. In the wafer peeling unit 22, the used substrate S1 is collected in a collection box (not shown). For convenience of explanation, the transfer member T1 onto which the micro LEDs of each color are transferred is referred to as a first carrier C1 (see FIG. 8). Further, in the specification, for convenience of explanation, the transfer member T1 to which the red micro LED 11a is transferred is indicated as C1(R), and the transfer member T1 to which the green micro LED 11b is transferred is indicated as C1(G). , the transfer member T1 onto which the blue micro LEDs 11c are transferred may be referred to as C1(B).

Next, the ultraviolet irradiation device section 3 will be described. The ultraviolet irradiation unit 3 irradiates the transfer member T1 (first carrier C1) onto which electronic components such as the micro LEDs 11a have been transferred with ultraviolet rays while the transfer member T1 (first carrier C1) is treated to prevent exposure to oxygen. , a device for reducing the adhesive force of the transfer member T1. More specifically, the ultraviolet irradiation device section 3 irradiates the transfer member T1 with ultraviolet rays in an inert gas atmosphere. The atmosphere of an inert gas means, for example, a state in which oxygen gas is purged with an inert gas. Here, the inert gas is nitrogen (N ₂ ) gas, for example. Nitrogen gas is known as an inert gas because its atoms form triple bonds, which is very strong and has poor reactivity. Therefore, it is suitable for purging oxygen gas with nitrogen gas. However, rare gas elements such as argon gas are also known as inert gases, and the gas is not limited to nitrogen gas, and rare gas elements such as argon gas may be used.

FIG. 8 is an explanatory diagram showing the configuration of the ultraviolet irradiation device. The ultraviolet irradiation device section 3 includes a UV shielding chamber 30, a UV light source 31, a sealed box 32, an inlet valve 33, a flow meter 34, a gas supply pipe 35, an outlet valve 36, an oximeter 37, a gas discharge pipe 38 and a stage 39. Prepare. The UV shielding room 30 is a housing that shields ultraviolet rays. The UV light source 31 is, for example, a mercury lamp that emits ultraviolet light with a central wavelength of 365 nm. However, a UV-LED that emits ultraviolet light with a central wavelength of 365 nm may also be used.

The closed box 32 is a chamber for purging oxygen gas in the air with nitrogen gas. The sealed box 32 is provided with, for example, a window material 32a made of quartz glass that transmits ultraviolet rays, and a door 32b for carrying in the transfer member T1 (first carrier C1) onto which the micro LEDs 11a are transferred. The inlet valve 33 controls the supply of nitrogen gas. A flow meter 34 measures the diversion of nitrogen gas. The gas supply pipe 35 is a pipe for supplying nitrogen gas from a nitrogen cylinder (not shown). Outlet valve 36 controls the discharge of exhaust gas from closed box 32 . The oxygen concentration meter 37 detects the concentration of oxygen gas inside the closed box 32 from the concentration of the discharged oxygen gas. The gas exhaust pipe 38 is a pipe that guides exhaust gas from the closed box 32 to the outside. The stage 39 is used to carry the first carrier C1 into or out of the ultraviolet irradiation device section 3 .

Next, the second sticking device section 4 will be described. The second sticking device section 4 is a device for sticking a second transfer member T2 having a stronger adhesive force than the first transfer member T1 whose adhesive force is reduced to the electronic component transfer substrate S2.

FIG. 9 is an explanatory diagram showing the configuration of the second sticking device section 4. As shown in FIG. The second sticking device section 4 shown in FIG. 9 includes a sticking head 40 , a stage 41 and a pressure roller 42 . The second transfer member T2 is previously attached to the bonding head 40 in the initial state when the operation is started. The stage 41 is for mounting the substrate S2. The substrate S2 is, for example, a glass substrate such as alkali-free glass. By adopting the board S2, the following advantages are obtained when mounting from the carrier C2 (R, G, B) shown in FIG. 32 to the circuit board. In other words, in this mounting, heat bonding such as soldering or thermocompression is often used, so by using the same base material as the circuit board (mostly alkali-free glass), the difference in thermal expansion during heating is eliminated, and the micro LED and the circuit can be suppressed. The pressure roller 42 presses the transfer member T2 after bonding the second transfer member T2 and the substrate S2 together to increase adhesion between the second transfer member T2 and the substrate S2.

FIG. 10 is a schematic cross-sectional view of the second transfer member T2. The second transfer member T2 (hereinafter sometimes simply referred to as "transfer member T2") is, for example, an adhesive sheet. The transfer member T2 includes a substrate T21 and adhesive layers T22 and T23 laminated on both sides of the substrate T21. Furthermore, in the transfer member T2, a protective film F2 is attached to the adhesive layer T22. A protective film F3 is attached to the adhesive layer T23. For the transfer member T2 and the protective films F2 and F3, for example, a reusable highly heat-resistant adhesive sheet (manufactured by Kyosha Co., Ltd.) is used. The adhesive force of this transfer member T2 is, for example, 1 N/25 mm.

A sheet material such as a synthetic resin film can be used for the base material T21. From the viewpoint of heat resistance, the synthetic resin film is preferably, for example, a polyimide film. The adhesive layers T22 and T23 are made of a silicone-based adhesive resin. The protective films F2 and F3 are laminated films for protecting the adhesive layer T12, and are peeled off from the adhesive layers T22 and T23 during use. Therefore, the second transfer member T2 functions as a single-sided adhesive type when one of the protective films F2 and F3 is removed, and functions as a double-sided adhesive type when both the protective films F2 and F3 are removed. function as a thing. The film thickness of the substrate T21 is, for example, 50 μm, the film thickness of the adhesive layers T22 and T23 is, for example, 75 μm, and the film thickness of the protective films F2 and F3 is approximately several μm.

Next, the second transfer device section 5 will be described. The second transfer device section 5 adheres the first transfer member T1 and the second transfer member T2 together, and uses the difference in adhesive strength to transfer the electronic component (for example, the micro LED 11a) to the first transfer member. It is a device for transferring from the transfer member T1 to the second transfer member T2. The second transfer device section 5 includes a bonding section 51 and a transfer member peeling section 52 .

The lamination unit 51 is a device for precisely aligning the transfer member T1 (first carrier C1) to which the micro LED 11a is adhered and the transfer member T2, and then laminating them together.

FIG. 11 is an explanatory diagram showing the configuration of the laminating section 51. FIG. The bonding unit 51 includes a stage mechanism 51a, a suction stage 51b, a second camera 51c, a support stage 51d, an optical housing 51e, a suction head 51f, a first camera 51g, a reflecting mirror 51h, a zoom lens 51i, and an illumination light source 51j. and a third camera 51k.

A suction stage 51b for sucking the first carrier C1 and a second camera 51c for alignment are provided on the stage mechanism 51a. A support stage 51d that can move in the XYZ directions is provided above the stage mechanism 51a. The support stage 51d supports the optical housing 51e. A suction head 51f for sucking the second carrier C2 and a first camera 51g for positioning are provided on the lower side of the optical housing 51e. Here, the second carrier C2 is obtained by attaching the transfer member T2 to one side of the substrate S2. A reflection mirror 51h for observation is provided inside the optical housing 51e. A zoom lens 51i, an illumination light source 51j, and a third camera 51k for fine adjustment of alignment are provided on one side of the optical housing 51e. Details of the operation will be described later.

FIG. 12 is an explanatory diagram showing the configuration of the transfer member peeling section 52. As shown in FIG. The transfer member peeling unit 52 is a device for peeling and collecting the transfer member T1. The transfer member peeling section 52 includes a stage mechanism 52a, a recovery stage 52b, and an adhesive roller 52c.

The stage mechanism 52a includes an adsorption stage 52d that adsorbs the carrier C2 from the substrate S2 side, and a support table 52e that supports the fixing ring 19 of the carrier C1. The transfer member peeling section 52 uniaxially moves the adhesive roller 52c to wind up the transfer member T1 of the carrier C1 due to the difference in adhesive strength, and recover it to the recovery stage 52b.

Next, the control device section 6 will be explained. The control device section 6 is a device for controlling the first sticking device section 1 , the first transfer device section 2 , the ultraviolet irradiation device section 3 , the second sticking device section 4 and the second transfer device section 5 .

FIG. 13 is a block diagram showing an example of the hardware configuration of the control device section 6 shown in FIG. The control device section 6 shown in FIG. 13 is a computer for control, and includes a processor 6a, a storage 6b, a memory 6c, an input device 6d, a communication interface 6e, a display device 6f, and a bus 6g. The processor 6a, storage 6b, memory 6c, input device 6d, communication interface 6e and display device 6f are interconnected via a bus 6g. Note that the control device section 6 instructs the first sticking device section 1, the first transfer device section 2, the ultraviolet irradiation device section 3, the second sticking device section 4, and the second transfer device section 5 to operate, for example, In order to transmit control signals indicating instructions, the control unit 6 and each of the device units 1 to 5 are connected by wireless or wired communication lines. In addition, the control device section 6 comprehensively controls the execution order of the respective device sections 1-5.

The processor 6a executes control of the control device section 6. The storage 6b is, for example, a storage device such as an HDD (Hard Disk Drive) or flash memory, and stores programs and various data.

The memory 6c is a storage device such as a RAM (Random Access Memory), and is loaded with, for example, programs to be executed by the processor 6a. The input device 6d is, for example, a keyboard type or touch panel type input device. The communication interface 6e has, for example, a communication interface for data communication. The display device 6f is, for example, a liquid crystal monitor, and displays an operation menu screen and output results in accordance with instructions from the processor 6a.

In addition, the control device section 6 realizes various functions through cooperation between hardware such as the processor 6a, storage 6b, and memory 6c, and programs. This program includes a control program (transcription program) for realizing the transcription method according to the present invention.

According to the above-described transfer method, the control device section 6 uses the first transfer member T1 to which the micro LEDs are transferred for each of the colors R, G, and B according to a predetermined order, for example, to achieve full-color display. It is possible to sequentially transfer the micro LEDs of each color to one second transfer member T2 so as to form a corresponding arrangement pattern. As a result, the yield at the time of transferring the micro LEDs of each color can be improved. Details will be described later.

Next, the transfer method according to the present invention, which is executed using the transfer device configured in this way, will be described. Here, in this embodiment, the transfer method according to the present invention is realized by automating the operation of the transfer apparatus according to the present invention and the transfer and transfer of works between the respective apparatuses. Here, the work is an object to be processed such as the light transmissive substrate S1, the LED wafer S11, the first transfer member T1, the second transfer member T2, the first carrier C1 and the second carrier C2.

FIG. 14 is an explanatory diagram showing control by the control device section 6 of the transfer device shown in FIG. The control device section 6 operates the first sticking device section 1 , the first transfer device section 2 , the ultraviolet irradiation device section 3 , the second sticking device section 4 , the second transfer device section 5 through the control means 7 . Controls the transfer and transfer of workpieces between devices in

The control means 7 is, for example, a control device having one or more robot arms capable of processing such as delivery of workpieces. and carry out processing. In addition, in the control means 7, the process of transferring and transporting the work is a well-known technology, so detailed description thereof will be omitted.

FIG. 15 is a flow chart showing one embodiment of the transfer method according to the present invention. 16A and 16B are explanatory diagrams showing the steps of an embodiment of the transfer method according to the present invention by changing the plan view of the object to be processed. 17A and 17B are explanatory diagrams showing the steps of an embodiment of the transfer method according to the present invention by changing the end view of the object to be processed.

Regarding the changes in the plan view and the end view of the object to be processed, in detail, FIGS. 16(a) and 17(a) are explanatory diagrams in attaching the first transfer member (step S1). FIGS. 16B, 16C, 17B, and 17C are explanatory diagrams of the first transfer (step S2). FIG. 16(d) and FIG. 17(d) are explanatory diagrams of ultraviolet irradiation (step S3). FIGS. 16(e) and 17(e) are explanatory diagrams of the attachment of the second transfer member (step S5). FIGS. 16F, 16G, 17F, and 17G are explanatory diagrams of the second transfer (step S6). Hereinafter, an embodiment of the transfer method according to the present invention will be described in detail with reference to FIGS. 16 and 17 as well as other drawings.

First, when each unit 1 to 6 of the transfer device shown in FIG. 1 is powered on, each unit shifts to its initial state. The control device section 6 receives an instruction input for starting the operation of the transfer method according to the present invention via the input device 6d. Then, the control device section 6 controls the execution order of the respective sections 1 to 5 based on the control program for executing this transfer method, and first instructs the first pasting device section 1 to start operation. The 1st sticking apparatus part 1 starts operation|movement.

In this embodiment, first, the LED wafer S11 having the red micro LEDs 11a on its surface is placed on the suction stage 13 of the first attaching device section 1, and then step S1 is performed, and then steps S2 to S3 are performed. By executing this, the red micro LED 11a is transferred to create a transfer member T1 after being irradiated with ultraviolet rays. Furthermore, in this embodiment, the LED wafer S11 having the green micro-LEDs 11b on the surface and the LED wafer S11 having the blue micro-LEDs 11c on the surface are sequentially subjected to the same process.

FIG. 18 is an explanatory diagram showing the operation of the first sticking device section 1 in a side view. However, the object to be processed is drawn as an end view, as described above, in order to make the explanation easier to understand. FIG. 19 is an explanatory diagram showing the operation of the first sticking device section 1 in plan view. In FIG. 19, the illustration of the constituent elements of the first sticking device section 1 is partially omitted for convenience of explanation. Note that the LED wafers S11 for each color, which are prepared in advance, are stored in, for example, storage boxes (not shown). In attaching the first transfer member (step S1), for example, a robot arm is used to carry the tray 10 (see FIG. 19A) onto the suction stage 13 of the first attaching device section 1. . On the tray 10, when the first step S1 is performed, an LED wafer S11 having a red micro LED 11a on its surface and a fixing ring 19 surrounding the LED wafer S11 with a space therebetween are mounted. are placed. In the first pasting device section 1, first, when the loaded LED wafer S11 is positioned, the stage mechanism 12 raises the suction stage 13 to bring the LED wafer S11 and the fixing ring 19 into contact with the transfer member T1. Let FIG. 18(a) illustrates a state in which the LED wafer S11 and the fixing ring 19 are brought into contact with the transfer member T1. 19(a) shows the state immediately before the tray 10 is carried into the first sticking device section 1. FIG.

Next, the first pasting device section 1 moves the pressure roller 14 in one axial direction while rotating it. 18(b) and 19(b) show the state after the pressure roller 14 has been moved. Thereby, the transfer member T1 is attached to the LED wafer S11. Subsequently, the first sticking device section 1 lowers the tape cutter 16 to cut the transfer member T1 around the fixing ring 19 . FIG. 18(c) shows a state in which the tape cutter 16 cuts the transfer member T1. FIG. 19(c) shows a state after the tape cutter 16 cuts the transfer member T1. In FIG. 19(c), the circular solid black line indicates the cut portion of the transfer member T1. As a result, the transfer member T1 itself is not interrupted.

Subsequently, the first pasting device section 1 returns the tape cutter 16 to its original position, and lowers the suction stage 13 . FIG. 18(d) shows the end state of the processing of the first sticking device section 1. FIG. FIG. 19(d) shows removal of the tray 10 on which the LED wafer S11 with the transfer member T1 attached is placed. Then, this tray 10 is conveyed to the LLO section 21 of the first transfer device section 2 via the robot arm of the control means 7 according to a command from the control device section 6 . FIG. 16(a) shows a plan view of the LED wafer S11 to which the transfer member T1 is attached by attaching the first transfer member (step S1). Further, FIG. 17(a) shows an end view of the LED wafer S11 taken along line BB (hereinafter simply referred to as "end view" in FIG. 17).

Next, in the first transfer (step S2), the LLO section 21 performs laser lift-off. In this case, since the LED wafer S11 is irradiated with laser light from the rear surface thereof, the robot arm reverses the LED wafer S11 to which the transfer member T1 is attached and then places it on the stage 21i of the LLO section 21 shown in FIG. be. After aligning the LED wafer S11 with the

alignment cameras

21g and 21h, the LLO unit 21 performs laser lift-off. 16(b) and 17(b) show a plan view and an end view of the LED wafer S11 to which the transfer member T1 is adhered under the laser irradiation by laser lift-off. Then, the LED wafer S11 attached to the transfer member T1 is transported to the wafer peeling section 22 .

Next, in the first transfer (step S2), the LED wafer S11 attached to the transfer member T1 shown in FIG.

20A and 20B are explanatory diagrams showing the operation of the wafer peeling section 22. FIG. 20(a) shows the state before peeling of the LED wafer S11, (b) shows the state in which the LED wafer S11 is being peeled, and (c) shows the state after the LED wafer S11 is peeled. is shown. In the first transfer (step S2), the wafer peeling unit 22 first lowers the suction head 22a to suck the back surface of the LED wafer S11 (see FIG. 20(a)).

Subsequently, the wafer peeling unit 22 tilts the push-up stage 22c in an oblique direction to lift one end of the LED wafer S11 from below while lifting the LED wafer S11 with the suction head 22a. The purpose of pushing up the LED wafer S11 from below in this manner is to slightly lift one end of the LED wafer S11 from the transfer member T1. That is, first, the LED wafer S11 is peeled off from one end.

The reason why the peeling off of one end of the LED wafer S11 is used as a trigger to lift the LED wafer S11 upward for peeling is to reduce the peeling force as much as possible. In this way, the LED wafer S11 is gradually peeled off from the transfer member T1, starting from the peeling of one end of the LED wafer S11. Therefore, the wafer peeling unit 22 is characterized by lifting the LED wafer S11 obliquely instead of vertically for such peeling.

That is, the wafer peeling section 22 can easily peel (separate) the substrate S1 by using the push-up stage 22c and transfer the micro LEDs 11a onto one surface of the transfer member T2 (see FIG. 20(c). ). As a result, the first carrier C1 having the micro LED 11a and the fixing ring 19 transferred to one surface of the transfer member T2 is produced. Then, the first carrier C1 is conveyed to the ultraviolet irradiation device section 3 by the control means 7 according to the command from the control device section 6 .

Next, in the ultraviolet irradiation (step S3), the transfer member T1 is irradiated with ultraviolet rays in a state of being treated to prevent exposure to oxygen, thereby reducing the adhesion of the transfer member T1.

FIG. 21 is a detailed flowchart (subroutine) of the ultraviolet irradiation process shown in FIG. FIG. 22 is an explanatory diagram showing the operation of the ultraviolet irradiation device section 3. As shown in FIG. In step S31, the first carrier C1 is installed. Specifically, in step S31, a process of installing the tray 10 on which the first carrier C1 is placed inside the sealed box 32 of the ultraviolet irradiation device section 3 is performed. In this case, the door 32b of the ultraviolet irradiation device section 3 is opened, and the first carrier C1 is loaded. FIG. 22(a) shows how the first carrier C1 is loaded.

In step S32, the carrier is housed in the sealed box and the door 32b is closed. In step S33, the inlet valve 33 is opened to allow nitrogen gas to flow in, and the outlet valve 36 is also opened to release the exhaust side. In step S34, the oxygen concentration is measured by the oxygen concentration meter 37 until the oxygen concentration becomes less than 0.5%. When the oxygen concentration becomes less than 0.5%, in step S35, ultraviolet irradiation is started under a nitrogen gas atmosphere. FIG. 16(d) and FIG. 17(d) show a plan view and an end view of the first carrier C1 while the transfer member T1 is being irradiated with ultraviolet rays UV.

In the ultraviolet irradiation device section 3, when the transfer member T1 is irradiated with ultraviolet rays UV in order to reduce the adhesive strength of the first transfer member T1, an ultraviolet curing reaction by photopolymerization occurs in the adhesive layer T12. In the UV curing reaction, in the presence of a photopolymerization initiator, the photopolymerization initiator is first converted into radicals (chemical species having unpaired electrons) by UV irradiation. Subsequently, the radical reacts with a polymer or oligomer having a polymerizable group as a component of the pressure-sensitive adhesive layer T12 and is activated. Then, the adhesive layer T12 is cured by chain-bonding these polymers and oligomers. As a result, the adhesive strength of the first transfer member T1 is reduced.

In step S35, for example, the first transfer member T1 is irradiated with ultraviolet rays having a center wavelength of 365 nm. Optimal ultraviolet irradiation conditions vary depending on the type of UV stripping tape and UV lamp used. The UV irradiation amount is a value obtained as an integrated amount of light, and is calculated by the following formula: integrated amount of light (mJ/cm ² )=illuminance (mW/cm ² )×irradiation time (sec). Here, in terms of unit conversion, there is a relationship of 1 (mW·h/cm ² )=3600 (mJ/cm ² ). In the present embodiment, the optimum ultraviolet irradiation conditions are obtained from experiments, and the integrated light intensity is set to 700 (mJ/cm ² ), for example.

In this embodiment, a so-called 180-degree peel test is performed in advance in order to confirm the effect of ultraviolet irradiation. The 180-degree peel test is based on the test method specified in Japanese Industrial Standards (JIS standard (JIS Z 0237)). In this test method, a tensile test stand (MX-500N (manufactured by IMADA)) and a force gauge (ZTA-50N (manufactured by IMADA)) were used. Then, as test conditions, (1) a first transfer member T1 (model number: UB3103AC) as a UV peeling tape, (2) a glass substrate manufactured by Corning (model number: EagleXG) as an adherend, and (3) as a test mode 180 degree peel test, (4) tape width 25 mm, (5) peel speed 5 mm / sec, (6) peel section 30 mm, a force gauge attached to the tensile test stand, attached to the adherend First transfer A 180-degree peel test was performed on the member T1. As a result, the adhesive strength of the first transfer member T1 decreased from 15 (N/25 mm) to 0.1 (N/25 mm) due to the ultraviolet irradiation.

Here, when the ultraviolet UV is irradiated without purging the first transfer member T1 with nitrogen gas, the oxygen in the air acts to deactivate the radicals in the adhesive layer T12 that cause the ultraviolet curing reaction. and photopolymerization is inhibited. If the photopolymerization is inhibited, the decrease in adhesive strength is suppressed, so in the second transfer (step S6) described later, for example, all the micro LEDs 11a are not transferred, and some of the micro LEDs 11a remain on the substrate 2. to happen. This leads to a low yield. In other words, it means that the transfer rate at which the micro LEDs 11a are transferred to the transfer member T2 is degraded. In the present embodiment, nitrogen gas purging is performed as a treatment to prevent exposure to oxygen, which blocks oxygen from entering the pressure-sensitive adhesive layer T12, thereby preventing inhibition of photopolymerization.

Therefore, in this embodiment, it is possible to achieve a transfer rate of 100% or a transfer rate close to it. As a result, in the manufacturing process of the micro LED display, it is possible to suppress defective mounting of the micro LED on the circuit board, and to prevent the process of repairing in the case where the transfer rate is 100%.

Next, in step S36, ultraviolet irradiation is terminated, and the inlet valve 33 is closed to stop the inflow of nitrogen gas. In step S37 , the first carrier C1 that has been irradiated with ultraviolet light is unloaded from the sealed box 32 . Then, the process shown in FIG. 21 is terminated, the process returns to the process of the flowchart shown in FIG. 15, and the process proceeds to step S4.

In step S4, it is determined whether or not the micro LEDs have been individually transferred to the first transfer member T1 for each color. In this embodiment, the red micro LED 11a, the green micro LED 11b, and the blue micro LED 11c are individually transferred onto the transfer member T1, so three first carriers C1 (hereinafter simply referred to as "carriers C1") are prepared for each color. ) will be created. When the carrier C1(R) made of the transfer member T1 to which the red micro LED 11a is transferred is produced, the determination in step S4 is No. In this case, after the carrier C1(R) is transported to the bonding section 51 of the second transfer device section 5, steps S1 to S1 shown in FIG. The processing of S3 is repeated. In the present embodiment, the carrier C1(R) may be temporarily stored in a storage cassette tray (not shown) without being transported to the bonding section 51. FIG.

By repeating the above steps S1 to S3, when the carrier C1 (G) composed of the transfer member T1 to which the green micro LED 11b has been transferred is created, the determination in step S4 becomes No again. In this case, the carrier C1(G) is temporarily stored in a storage cassette tray (not shown). Then, in order to transfer the next blue micro LED 11c to the transfer member T1, the processes of steps S1 to S3 shown in FIG. 15 are repeated.

By repeating the above steps S1 to S3, when the carrier C1 (B) composed of the transfer member T1 to which the blue micro LED 11c is transferred is created, the determination in step S4 is Yes. Then, the process proceeds to the attachment of the second transfer member (step S5).

In attaching the second transfer member (step S5), the second transfer member T2 having stronger adhesive force than the first transfer member T1 whose adhesive force is lowered is attached to the electronic component transfer substrate S2. Attaching process is performed.

FIG. 23 is an explanatory diagram showing the operation of the second sticking device section 4. FIG. The second bonding device section 4 lowers the bonding head 40 to bond the transfer member T2 and the substrate S2 together (see FIG. 23(a)). Here, in this embodiment, the adhesive force between the transfer member T2 and the substrate S2 is made larger than the adhesive force between the bonding head 40 and the transfer member T2.

Subsequently, when the second bonding device section 4 raises the bonding head 40, the transfer member T2 is peeled off and adheres to the substrate S2. In this state, the second pasting device section 4 uniaxially moves the stage 41 toward the pressure roller 42 side, and the pressure roller 42 rotates while pressing the transfer member T2 ( See FIG. 23(b)). When the pressing roller 42 finishes pressing the transfer member T2, the transfer member T2 is adhered more firmly to the substrate S2 than when no pressure is applied (see FIG. 23(c)). The substrate S2 with the transfer member T2 attached to one side thereof is referred to as a second carrier C2. FIGS. 16(e) and 17(e) show a plan view and an end view of the second carrier C2 produced in step S5. A second carrier C2 (hereinafter sometimes simply referred to as “carrier C2 ”) is conveyed to the bonding section 51 of the second transfer device section 5 . On the other hand, the second sticking device section 4 moves the stage 41 to return to the initial state shown in FIG.

Next, in the second transfer (step S6), the first transfer member T1 and the second transfer member T2 are adhered to each other, and the electronic components are transferred from the first transfer member T1 using the difference in adhesive force. A process of transferring to the second transfer member T2 is performed. Incidentally, when the first transfer member T1 and the second transfer member T2 are bonded together, the first carrier C1 and the second carrier C2 are apparently bonded together.

24A and 24B are explanatory diagrams showing the operation of the lamination unit 51. FIG. 25A and 25B are explanatory diagrams showing the operation of the transfer member peeling section 52. FIG. FIG. 26 is a flow chart (subroutine) showing the process when the red micro LED 11a is used in the second transfer step shown in FIG. is.

In step S61 shown in FIG. 26, the bonding unit 51 bonds the carrier C1(R) and the carrier C2 together. Specifically, in the state shown in FIG. 11, the lamination unit 51 first installs the carrier C1 (R) and the carrier C2, and then moves the stage mechanism 51a in the horizontal direction to move the first camera 51g. , the carrier C1(R) is observed and .theta. alignment is performed. Thereby, the bonding unit 51 designates the bonding position of the carrier C1(R) with the first alignment mark. Subsequently, the bonding unit 51 moves the stage mechanism 51a in the horizontal direction to observe the carrier C2 with the second camera 51c and perform θ alignment. Thereby, the bonding unit 51 designates the bonding position of the carrier C2 with the second alignment mark.

The bonding unit 51 causes the carrier C1 (R) and the carrier C2 to face each other based on their bonding positions by moving the stage mechanism 51a in the horizontal direction again, and then lowers the support stage 51d. The carrier C1 (R) and the carrier C2 are stopped at a position close to each other. Further, the lamination unit 51 finely adjusts the positions of the second alignment mark of the carrier C2 and the micro LED 11a of the carrier C1(R) using the third camera 51k. After that, the bonding section 51 further lowers the support stage 51d to bring the carrier C1(R) and the carrier C2 into contact with each other, and then pressurize them. FIG. 24(a) shows the state after the carrier C1(R) and the carrier C2 are pressurized. Then, the bonding section 51 releases the suction head 51f and raises the support stage 51d. FIG. 24(b) shows the state after the transfer member T1 and the transfer member T2 are bonded together. As a result, the transfer member T1 and the transfer member T2 are bonded together, and as a result, the bonding of the carrier C1 (R) and the carrier C2 is completed.

16(f) and 17(f) are a plan view and an end view of the combined carrier C1(R) and carrier C2, showing a state in which the carrier C1(R) and the carrier C2 are bonded together. is shown.

The bonding unit 51 carries out the carrier C1 (R) and the carrier C2 via the robot arm. As shown in FIG. 12, the carrier C2 is placed on the suction stage 52d on the stage mechanism 52a, and the fixing ring 19 of the carrier C1(R) is supported by the support table 52e. be done.

Next, in step S62 shown in FIG. 26, the transfer member T1 is peeled off. Therefore, in FIG. 25, the transfer member peeling section 52 is moved uniaxially toward the collection stage 52b while rotating the adhesive roller 52c (see FIG. 25(a)). Since the adhesive roller 52c has a higher adhesive force than the transfer member T2, the adhesive roller 52c can sequentially wind up the transfer member T1 (see FIG. 25(b)). Thereby, in step S63, the second transfer device section 5 can complete the carrier C2(R).

Thereafter, the transfer member peeling section 52 causes the transfer member T1 to be attracted to the recovery stage 52b by rotating the adhesive roller 52c around which the transfer member T1 is wound on the recovery stage 52b, and removes the transfer member T1 from the adhesive roller 52c. Remove (see FIG. 25(c)). In this manner, the transfer member peeling unit 52 rotates the adhesive roller 52c and moves it in the uniaxial direction to sequentially wind the transfer member T1, thereby preventing the micro LEDs 11a from remaining on the transfer member T1. can.

FIGS. 16(g) and 17(g) show a plan view and an end view of the second carrier C2(R). In the specification, for convenience of explanation, the carrier in which the transfer member T1 is separated and the red micro LED 11a is transferred to the transfer member T2 is referred to as a second carrier C2 (R). is described as the second carrier C2(G), and in the case of the blue micro LED 11c, it may be described as the second carrier C2(G).

FIG. 27 is an explanatory diagram showing the configuration of the second carrier C2 (R) to which the red micro LED 11a is transferred, (a) being a partially enlarged plan view, and (b) being CC of (a). It is a line sectional view. In step S63, when the carrier C2(R) is produced, the carrier C2(R) is transported to be used again for bonding, and is attracted to the suction head 51f of the bonding section 51. FIG.

Next, when the process shown in FIG. 26 is completed, returning to the flow chart shown in FIG. 15, it is determined in step S7 whether or not the micro LEDs have been individually transferred to the transfer member T2 for each color. Specifically, it is determined whether or not the red micro LED 11a, the green micro LED 11b, and the blue micro LED 11c are individually transferred to the transfer member T2. When the red micro LED 11a is transferred to the transfer member T2, the judgment is No, and the process returns to step S6. In step S6, the green micro LED 11b is transferred to the transfer member T2 in the same manner as the red micro LED 11a. .

FIG. 28 is a flowchart showing the process when using the green micro LED 11b in the second transfer step shown in FIG. In step S64, the bonding section 51 performs the same process as in step S61 on the carrier C1(G). In this case, the carrier C2(R) and the carrier C1(G) are stuck together.

In step S65, the transfer member peeling section 52 performs the same process as in step S62 on the carrier C1(G). Subsequently, in step S66, a carrier C2 (R, G) is created by transferring the green micro LED 11b to the carrier C2 (R).

FIG. 29 is an explanatory diagram showing the configuration of the second carrier C2 (R, G) to which the green micro LED 11b is further transferred, (a) being a partially enlarged plan view, and (b) being a It is a CC line sectional view.

FIG. 30 is an explanatory diagram showing the second transfer process shown in FIG. FIG. 30(a) shows alignment between carrier C1 (G) and carrier C2 (R). Before the carrier C1 (G) and the carrier C2 (R) are bonded together, the transfer member T1 composed of the base film T11 and the adhesive layer T12 is irradiated with ultraviolet rays, so that the carrier C1 (G ), the adhesive layer T12 is cured and its adhesive force is lowered.

FIG. 30(b) shows a state in which carrier C1 (G) and carrier C2 (R) are bonded together. Even if the predetermined pressure P is applied in this state, the micro LEDs 11a on the carrier C2(R) do not deeply sink into the adhesive layer T12 on the carrier C1(G) side. FIG. 30(c) shows the carrier C2 (R, G) after the transfer member T1 has been separated. Even if the transfer member T1 is peeled off, chips such as the

micro LEDs

11a and 11b are not required to be peeled off. By adopting such a method, even if the carrier C1 and the carrier C2 are repeatedly stuck together, no chips are peeled off, and a high transfer rate can be achieved. Therefore, in the present embodiment, each time a plurality of carriers C1 are sequentially attached to one carrier C2 and the chips are transferred to the transfer member T2, the chips that have already been transferred to the carrier C2 are transferred to the transfer member T2. It is possible to avoid a situation in which a part of the chip is peeled off and left untransferred.

Next, in step S66, when the carrier C2 (R, G) is produced, the carrier C2 (R, G) is transported to be used again for bonding, and is attracted to the suction head 51f of the bonding section 51. be done. When the process shown in FIG. 28 is completed, the process returns to the flowchart shown in FIG. 15. In step S7, it is determined whether or not the red micro LED 11a, the green micro LED 11b, and the blue micro LED 11c have been individually transferred to the transfer member T2. be judged. When the red micro-LED 11a and the green micro-LED 11b are transferred to the transfer member T2, the determination is No, and the process returns to step S6. In step S6, the blue micro-LED 11c is transferred in the same manner as the red micro-LED 11a. Transfer to member T2.

FIG. 31 is a flowchart showing the process when using the blue micro LED 11c in the second transfer step shown in FIG. In step S67, the bonding section 51 performs the same process as in step S61 on the carrier C1(B). In this case, carrier C2 (R, G) and carrier C1 (B) are bonded together.

In step S68, the transfer member peeling section 52 performs the same process as in step S62 on the carrier C1(B). Subsequently, in step S66, a carrier C2 (R, G, B) is created by transferring the green micro LED 11b to the carrier C2 (R, G).

FIG. 32 is an explanatory diagram showing the configuration of the second carrier (R, G, B) to which the blue micro LED 11c is further transferred, (a) being a partially enlarged plan view, (b) being (a) 1 is a cross-sectional view taken along line CC of FIG. Using this carrier C2 (R, G, B), the red micro LED 11a, the green micro LED 11b, and the blue micro LED 11c are mounted on the circuit board in the manufacturing process of the micro LED display.

Next, when the processing shown in FIG. 31 is completed, returning to the flow chart shown in FIG. 15, in step S6, it is determined whether or not the red micro LED 11a, the green micro LED 11b, and the blue micro LED 11c have been individually transferred to the transfer member T2. is determined. In this case, the determination is Yes, and the processing of the flow chart shown in FIG. 15 ends.

As described above, according to the present invention, the first transfer member T1 on the side of the first carrier C1 employs a UV peeling tape, and is deoxidized in the step prior to bonding with the second carrier C2. By performing the ultraviolet irradiation step, it is possible to achieve a high transfer rate to the second carrier C2.

[First modification]
Next, a first modification of the transfer method according to the present invention will be described. FIG. 33 is a flowchart showing a first modification of the transfer method according to the invention. Note that the description of the same processing as in the above-described embodiment will be omitted or simplified. In the flowchart shown in FIG. 15, after the first carrier C1(R), the first carrier C1(G), and the first carrier C1(B) are prepared in advance, they are sequentially transferred to the second transfer member T2. However, the present invention is not limited to this.

In FIG. 33, first, in attaching the first transfer member (step S11), the transfer member T1 is attached to the LED wafer S11 as in the step S1 shown in FIG.

In the first transfer (step S12), the red micro LEDs 11a are attached to the transfer member T1 in the same manner as in step S2 described above.

In the ultraviolet irradiation (step S13), as in the above-described step S3, the transfer member T1 is irradiated with ultraviolet rays while being treated to prevent exposure to oxygen, thereby reducing the adhesion of the transfer member T1.

Subsequently, in step S14, it is determined whether or not it is the first transfer of the transfer member T1. This is because one transfer member T2 is used for three transfer members T1 produced for each color. ). Therefore, when the red micro LED 11a is attached to the transfer member T1, the determination in step S14 is Yes, and the process proceeds to the next second transfer (step S16). Then, in step S17, it is determined whether or not all the micro LEDs have been transferred, and when only the red micro LEDs 11a have been transferred (step S17: No determination), the process returns to step S11 to transfer the green micro LEDs 11b. , steps S11 to S14 and S16 are executed.

In step S17, it is determined whether or not all the micro LEDs have been transferred, and when only the red micro LED 11a and the green micro LED 11b have been transferred (step S17: No determination), the process returns to step S11 to transfer the blue micro LED. Steps S11 to S14 and S16 are performed for the micro LED 11b, and finally the second carrier C2 (R, G, B) is produced in the same manner as in the present embodiment.

As described above, also in the first modification of the transfer method according to the present invention, the transfer member T1 onto which the electronic components such as the micro LEDs have been transferred is treated to prevent exposure to oxygen, and then the transfer member is exposed to ultraviolet rays. Since the adhesive strength of the transfer member T1 is reduced by irradiating T1, the exposure to oxygen does not adversely affect the adhesive strength of the transfer member T1. By bonding the member T2, the yield at the time of transfer of the electronic component such as the micro LED can be improved.

[Second modification]
Next, a second modification of the transfer method according to the present invention will be described. In the above-described embodiment, three-color micro-LEDs of red micro-LED 11a, green micro-LED 11b, and blue micro-LED 11b are used in order to correspond to the light emission method of the RGB micro-LED display. The present invention is not limited to this method. That is, as a light emitting method of the micro LED display, the present invention may be applied to a micro LED display in which ultraviolet light emitting diodes (UV-LED) are color-converted by fluorescent materials (RGB phosphors). In this case, the micro LEDs transferred to the second transfer member T2 may be ultraviolet light emitting diodes of only one color.

34A and 34B are explanatory diagrams showing the configuration of the second carrier to which the micro LED emitting ultraviolet light is transferred, where (a) is a partially enlarged plan view and (b) is a cross section taken along line DD of (a). It is a diagram. A micro LED 11d shown in FIG. 34 is an ultraviolet light emitting diode whose LED main body is made mainly of gallium nitride (GaN), for example. For the micro LED 11d, an ultraviolet light emitting diode that emits light having a peak wavelength of 385 nm, for example, may be selected in consideration of the conversion efficiency of the RGB phosphors.

In the second modification, only one transfer member T1 to which the micro LEDs 11d are transferred may be used, so in the determination of step S4 in the flow chart shown in FIG. 15, the first determination is Yes. Then, in the second transfer (step S6), the micro LED 11d is transferred to the transfer member T2, thereby creating the second carrier C2 (UV-LED).

As described above, the transfer device and transfer method according to the present invention can be applied even when micro LEDs 11d emitting single-color ultraviolet light are employed.

Next, supplementary matters for the above embodiment will be described. In the above-described embodiment, the transfer member T1 is irradiated with ultraviolet rays using the ultraviolet irradiation device section 3 in the sealed box 32 under an inert gas atmosphere. Not limited. In the present invention, for example, a local exhaust system may be employed in the ultraviolet irradiation device section 3 . In the local exhaust system, nitrogen gas may be locally blown only on the micro LEDs attached to the transfer member T1 to exhaust the air. Further, in the present invention, for example, a semi-open type system may be employed in the ultraviolet irradiation device section 3 . In the semi-open type method, nitrogen gas may be flowed toward the micro LEDs attached to the transfer member T1 without using the closed box 32 .

Further, in the present invention, as a process for preventing exposure to oxygen, the transfer member T1 may be irradiated with ultraviolet rays in a vacuum chamber having a preset degree of vacuum.

In the above embodiment, a plurality of the first pasting device section 1, the first transfer device section 2, and the ultraviolet irradiation device section 3 are prepared, and the transfer member T1 (the first A configuration may be adopted in which the time required to create the carrier C1) is shortened.

The above-described embodiments are shown to the extent that the present invention can be understood and implemented, and the present invention is not limited thereto. The present invention can be variously changed and modified without departing from the scope of the technical idea indicated in the claims.

DESCRIPTION OF SYMBOLS 1... 1st sticking apparatus part 2... 1st transfer apparatus part 3... Ultraviolet irradiation apparatus part 4... 2nd sticking apparatus part 5... 2nd transfer apparatus part 6... Control device part S1... Light transmissive substrate S2 ... substrate for transferring electronic components T1 ... first transfer member T2 ...

second transfer member

11a, 11b, 11c, 11d ... micro LED (electronic component)

Claims

A transfer device for transferring an electronic component to a transfer member,
a first pasting device for pasting a first transfer member whose adhesive strength is reduced by UV irradiation onto a light transmissive substrate having a plurality of electronic components formed on one surface thereof according to a predetermined arrangement;
a first transfer device section that transfers the electronic component to one surface of the first transfer member by peeling the electronic component from the light transmissive substrate via laser lift-off;
The first transfer member to which the electronic component has been transferred is irradiated with ultraviolet rays in a state of being treated to prevent exposure to oxygen, thereby increasing the adhesion of the first transfer member. An ultraviolet irradiation device that lowers the
a second pasting device unit for pasting a second transfer member having a stronger adhesive force than the first transfer member having a reduced adhesive force to the substrate for transferring the electronic component;
The first transfer member and the second transfer member are pasted together, and the electronic component is separated from the first transfer member by using the difference in adhesive force, and is attached to the second transfer member. a second transfer device section for transferring;
a control device section that controls the first sticking device section, the first transfer device section, the ultraviolet irradiation device section, the second sticking device section, and the second transfer device section;
A transfer device comprising:
2. The transfer device according to claim 1, wherein the ultraviolet irradiation device section irradiates the first transfer member with the ultraviolet rays in an inert gas atmosphere. .
The transfer device according to claim 2, wherein the inert gas is nitrogen gas.
the electronic components are red (R), green (G), and blue (B) micro LEDs;
The control unit uses a first transfer member to which micro LEDs are transferred for each color of R, G, and B, according to a predetermined order, so as to form an array pattern corresponding to full-color display. wherein the micro LEDs are sequentially transferred to one of the second transfer members,
2. The transfer device according to claim 1, wherein:
A transfer method for transferring an electronic component to a transfer member,
a step of attaching a first transfer member whose adhesive strength is reduced by ultraviolet irradiation to a light transmissive substrate having a plurality of electronic components formed on one surface according to a predetermined arrangement;
transferring the electronic component to one surface of the first transfer member by peeling the electronic component from the light-transmissive substrate via laser lift-off;
The first transfer member to which the electronic component has been transferred is irradiated with ultraviolet rays while being treated to prevent exposure to oxygen, thereby reducing the adhesion of the first transfer member. An ultraviolet irradiation step to cause
a step of attaching a second transfer member having a stronger adhesive force than the first transfer member having a reduced adhesive force to the substrate for transferring the electronic component;
The first transfer member and the second transfer member are pasted together, and the electronic component is separated from the first transfer member by using the difference in adhesive force, and is attached to the second transfer member. a step of transferring;
A transfer method comprising: