KR102548400B1 - Led transport method - Google Patents

Abstract

The present invention relates to an LED transfer method for inspecting whether an LED chip formed on a wafer is normally operating and transferring only normal LEDs to a target substrate. In order to achieve the above object, the LED transfer method of the present invention selects and transfers only the first group LEDs from among the LEDs formed on the first wafer, and selects and transfers only the first group LEDs from among the LEDs formed on the second wafer. It is characterized in that only normal LEDs are disposed on the target substrate by selecting and transferring the second group LEDs formed in the excluded positions.

Description

LED transfer method {LED TRANSPORT METHOD}

The present invention relates to an LED transport method. More specifically, it relates to an LED transfer method for inspecting whether LED chips formed on a wafer are normally operating, selecting only normal LEDs and transferring them to a target substrate.

Recently, development of micro LEDs having a size of several to several tens of micrometers is actively progressing so that LEDs can be widely used in light applications requiring low power consumption, miniaturization, and light weight.

However, although the process of selecting and inspecting whether the completed LED is electrically good before transferring it from the wafer to the target substrate is absolutely necessary, the size of the LED is very small, so there is no proper transfer and inspection method, and there is no proper transfer and inspection method. There is a problem that the LED is broken or damaged or a problem of an increase in unit price due to manual work. In addition, if a plurality of LEDs are transferred to a target substrate without directly inspecting the electrical quality of the plurality of LEDs on the wafer, the target substrate itself may become defective if defects in the LEDs are later found on the target substrate. In addition, the conventional method is a method of transferring a plurality of LEDs formed on a wafer one by one, and there is a problem in that mass production cost increases due to a long transfer time and a large number of repetitions of transfer.

Prior literature includes Korean Patent Registration No. 10-1183978 (Prior Document 1) and Korean Patent Registration No. 10-1585818 (Prior Document 2). Prior Document 1 relates to a jig unit for fixing an LED chip in order to inspect one LED chip. As in Prior Art 1, according to the prior art, LEDs must be inspected one by one, which is cumbersome and time-consuming. There is, and since the micro LED is very small and weak, it is impossible to inspect it as in Prior Document 1. Prior Document 2 has a problem that chips cannot be distinguished. Prior Document 2 relates to a micro device transfer method, and although a micro device can be picked up with a current applied to a transfer head, a quality inspection of the micro device is not possible. There is a problem with need.

In this way, according to the conventional LED inspection and transfer method, it cannot be applied to LEDs whose size is down to several microns, and in particular, there is no method for simultaneously inspecting and transferring a plurality of small LEDs formed on a wafer. Therefore, there is a need to develop a technology that simultaneously inspects a plurality of LEDs on a wafer for good quality with high precision, and selects and transfers only normally operating LEDs. Therefore, in the present invention, a good quality test is performed on the wafer before transferring the LEDs, and at the same time, good quality LEDs are required. A technique for selectively transferring only the micro LED determined to be proposed is proposed.

Republic of Korea Patent Registration No. 10-1183978 (registered on September 12, 2012) Republic of Korea Patent Registration No. 10-1585818 (registered on 2016.01.08)

A technical problem of the present invention is to provide a method for determining good quality LEDs on a wafer.

In addition, it is to provide a method for determining whether an LED separated from a wafer and transferred to a target substrate operates normally.

In addition, it is to provide a method capable of simultaneously inspecting whether a plurality of LEDs arranged on a wafer are operating normally.

In addition, an LED transfer method capable of selecting and transferring only normal LEDs determined to be in normal operation on a wafer is provided.

In addition, an LED transfer method capable of selecting and transferring normal LEDs on the second wafer corresponding to LEDs determined to be defective is provided.

In addition, it is to provide an LED transfer method capable of accurately corresponding each inspection unit and pickup unit to a plurality of LEDs arranged on a wafer.

On the other hand, the technical problems to be achieved by the present invention are not limited to the exemplary technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following descriptions.

In order to achieve the above object, the present invention relates to an LED transfer method for inspecting whether an LED chip formed on a wafer is normally operating, selecting only normal LEDs and transferring them to a target substrate. In order to achieve the above object, the LED transfer method of the present invention selects and transfers only the first group LEDs from among the LEDs formed on the first wafer, and selects and transfers only the first group LEDs from among the LEDs formed on the second wafer. It is characterized in that only normal LEDs are disposed on the target substrate by selecting and transferring the second group LEDs formed in the excluded positions.

According to the present invention, there is an effect of determining normal and abnormal operation of LEDs on a wafer.

In addition, there is an effect of discriminating normal and abnormal operation of LEDs separated from the wafer.

In addition, there is an effect that can quickly inspect by simultaneously determining whether a plurality of LEDs arranged on the wafer are operating normally.

In addition, since normal and abnormal LEDs can be sorted out and only normal LEDs can be selectively transferred, there is an effect that only normal LEDs can be quickly placed on a target substrate.

In addition, there is an effect that can be inspected and transferred without damaging the LED.

As a result, the cost for inspecting LEDs is reduced, only normal LEDs are identified and transported, so there is no need for a separate inspection process, and only non-defective LEDs can be quickly selected and placed.

1 and 2 are step diagrams showing a method for transferring an LED according to an embodiment of the present invention.
3 is a diagram showing a step-by-step method of transferring an LED according to an embodiment of the present invention.
4 is a diagram illustrating steps for inspecting whether an LED is normally operated according to an embodiment of the present invention.
5 and 6 are cross-sectional views showing the LED transfer method of the first embodiment of the present invention step by step.
7 and 8 are cross-sectional views showing step by step an LED transfer method according to a second embodiment of the present invention.
9 and 10 are cross-sectional views showing step-by-step the LED transfer method according to the third embodiment of the present invention.
11 and 12 are cross-sectional views showing step by step an LED transfer method according to a fourth embodiment of the present invention.
13 is a cross-sectional view showing the LED transport device according to the first embodiment.
14 is a cross-sectional view showing the LED transport device according to the second embodiment.
15 is a diagram illustrating an LED transfer method according to an embodiment.
16 is a diagram illustrating an LED transfer method according to another embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described below or shown in the drawings. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the present invention are omitted, and the same or similar numerals in the drawings indicate the same or similar components.

The objects and effects of the present invention can be naturally understood or more clearly understood by the following description, and the objects and effects of the present invention are not limited only by the following description.

Prior to the detailed description of the present invention, the LED to be described below is described as one of the preferred embodiments, and any semiconductor device capable of determining normal operation by supplying current in addition to the LED can be applied. More preferably, it can be more effective when applied to a device that emits light by supplying current, and in particular, it can be most effective when the present invention is applied to a micro LED, which is a very small device in units of several microns. In addition, a plurality of LEDs may be arranged side by side in a plurality of rows and columns on the wafer W according to an embodiment of the present invention. The structure of the LED may be a horizontal structure, a vertical structure or a flip chip type structure. However, for convenience of description, a flip-chip structure will be described in this specification. Additionally, the LED is a PN junction semiconductor having a P pole and an N pole, and may be provided so that the P pole and the N pole are exposed on the upper surface, respectively. let it do

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 are step diagrams showing a method for transferring an LED according to an embodiment of the present invention.

Referring to FIG. 1 , the LED transfer method of the present invention includes a first group LED pickup and transfer step (S100) and a second group LED pickup and transfer step (S200). In more detail, referring to FIG. 2, the first group LED pickup and transfer step (S100) includes an inspection step (S110) of inspecting whether the LEDs formed on the first wafer (W1) operate normally, and normal LEDs (Lo). A pick-up step (S120) of selecting and picking up only the picked-up LEDs (S120) and a transfer step (S130) of transferring the picked-up normal LEDs (Lo). A selective pick-up step of selecting and picking up only the normal LEDs (Lo) of the second wafer W2 corresponding to the position determined as the LEDs (Lx) (S220) and a selective transfer step of transferring the selected normal LEDs (Lo) (S230) includes

Hereinafter, referring to FIGS. 2 and 3 , an LED transfer method according to an exemplary embodiment will be described in more detail. FIG. 2 is a diagram showing a step-by-step method of transporting an LED according to an embodiment of the present invention, and FIG. 3 is a diagram showing a method of inspecting whether an LED operates normally according to an embodiment of the present invention step-by-step.

The inspection step (S110) is a step of inspecting whether the LEDs formed on the first wafer (W1) operate normally. Here, the first wafer W1 refers to a target wafer W manufactured in such a way that two or more LEDs are arranged, and will be described as the first wafer W1 to be distinguished from the second wafer W2, which is an auxiliary wafer to be described later. In detail, the inspection step (S110) is a step of inspecting whether the LEDs operate normally by supplying power to two or more LEDs formed on the first wafer (W1). More specifically, this is the step of supplying power to each LED formed on the first wafer W1 to discriminate between a normal LED (Lo) and a defective LED (Lx). Specifically, the normal operation of the LED may be determined by supplying power to each LED and measuring electrical characteristics, etc., but more preferably by supplying power to inspect the photoelectric characteristics through light generated by the operation of the LED The normal operation of the LED can be determined. Referring to FIG. 4 in more detail, after supplying power to two or more LEDs formed on the first wafer W1, light generated from each LED supplied with power can be detected through a separate photodetector. there is. The position of the defective LED (Lx) can be found by determining photoelectric characteristics such as intensity and uniformity of the detected light. Accordingly, the position of the detected defective LED (Lx) may be input to the LED transfer device 1 and controlled. At this time, one or more normal LEDs (Lo) formed at positions other than the detected defective LEDs (Lx) are hereinafter referred to as first group LEDs (L1) for convenience of description. Hereinafter, in the present specification, the first group LED (L1) is described as a normal LED (Lo) excluding the defective LED (Lx) determined to be defective through inspection, but the first group LED (L1) is selectively selected among the normal LEDs (Lo). ) or second group LED (L2). When the normal operation of the LEDs on the first wafer W1 is completed according to the above-described method, a pick-up step ( S120 ) may proceed.

The pick-up step (S120) is a step of selecting and picking up only the first group LEDs (L1), which are one or more normal LEDs (Lo) determined to be normal in the inspection step (S110). Referring to FIGS. 3 and 4 , in the inspection step S110, two or more LEDs of the entire area listed on the first wafer W1 may be simultaneously inspected, and among the two or more LEDs listed on the first wafer W1 You can also select some areas to inspect. In the entire area or the partial area inspected in the inspection step ( S110 ), the positions of the normal LEDs (Lo) and the defective LEDs (Lx) may be input to the LED transport device 1 . Here, for convenience of description, the LEDs determined as normal LEDs (Lo) are referred to as the first group LEDs (L1), and in the second wafer (W2) to be described later, they correspond to the positions of the defective LEDs (Lx) on the first wafer (W1). The normal LEDs (Lo) at the position are called the second group LEDs (L2). In the pick-up step (S120), only the 1st group LED (L1) at the position of the normal LED (Lo) input to the LED transfer device (1) is selected and picked up in the entire area or the partial area inspected by the inspection step (S110). can do. Thereafter, the picked up first group LEDs L1 may be transferred to a target substrate S or a separate substrate or tape 10 .

The transfer step (S130) is a step of transferring the first group LEDs (L1) that are determined to be normal in the pick-up step (S120) and picked up. At this time, the picked-up first group LEDs (L1) may be directly transferred to the target board (S), more preferably transferred to a separate tape 10 or the like temporarily before being mounted on the target board (S). may be In detail, in the transfer step (S130), the target substrate (S) or the tape 10 to which the group 1 LEDs (L1) are transferred has a position corresponding to the defective LED (Lx) determined to be defective in the inspection step (S110). It can be formed as an empty space. Therefore, when an empty space is formed, the target substrate S to be finally manufactured cannot be completed. A selective pick-up step (S220) and a selective transfer step (S230) may be further performed to additionally fill the empty space with the normal LED (Lo).

In the selective pick-up step (S220), after the normal LED (Lo) is transferred in the transfer step (S130), an empty space is formed from the second wafer (W2), which is an auxiliary wafer, to fill the target substrate (S) or tape (10) in which the empty space is formed. This is the step of picking up the normal LED (Lo) corresponding to the space. In detail, in the inspection step S110, the second group LED (L2) is set to the normal LED (Lo) of the second wafer (W2) corresponding to the position determined as the defective LED (Lx) of the first wafer (W1). This is the stage of selection and pickup. That is, this is a step of selecting and picking up the second group LEDs L2 formed at positions other than those corresponding to the first group LEDs L1 of the first wafer W1 among the LEDs formed on the second wafer W2. . More specifically, before selecting and picking up the second group LEDs L2 from the second wafer W2, it is preferable to check whether the LEDs at the corresponding position are in a normal state or not, and then pick them up. When the LED at the corresponding location is determined to be the defective LED (Lx), the normal LED (Lo) may be picked up again from another location without being picked up. Here, the LEDs additionally picked up in the selective pick-up step (S220) have been described as LEDs on the second wafer W2, which is an auxiliary wafer, but this is only an embodiment, and among the LEDs provided on a separate auxiliary board or auxiliary tape, the LED at the corresponding position can also be picked up and transported.

In the selective transfer step (S230), the second group LEDs (L2) picked up in the selective pick-up step (S220) are transferred to the target substrate (S) or tape 10 to which the first group LEDs (L1) are transferred in the transfer step (S130). This is the step of transferring to the empty space of . That is, this is a step of additionally transferring a normal LED (Lo) to a position where it is determined as a defective LED (Lx) of the first wafer (W1) and not transferred in the inspection step (S110). Therefore, by filling the empty space of the target substrate S or tape 10 by the selective transfer step (S230) with the second group LEDs L2 determined to be in normal operation, the target substrate S or tape ( 10) may be provided. At this time, in the selective pickup step (S220), when the LED at the corresponding position is determined as a defective LED (Lx) and cannot be picked up, the selective pickup step (S220) and the selective transfer step (S230) can be repeated two or more times.

Hereinafter, each embodiment of the LED transfer method of the present invention will be described in more detail with reference to FIGS. 5 to 12 . Prior to the description, each of the embodiments to be described later is embodied based on one embodiment, and the same parts as one embodiment are omitted, and different parts are mainly described. 5 and 6 are cross-sectional views showing the LED transfer method step by step according to the first embodiment of the present invention, FIGS. 7 and 8 are cross-sectional views showing the LED transfer method step by step according to the second embodiment of the present invention, and FIGS. 10 is a cross-sectional view showing the LED transfer method of the third embodiment of the present invention step by step. 11 and 12 are cross-sectional views showing the LED transfer method step by step according to the fourth embodiment of the present invention.

In the first to fourth embodiments to be described later, three LEDs fabricated on the wafer W are described for convenience of explanation, but this is only one embodiment and shown for convenience of description, and in actual applications, billions of LEDs It can also be applied to a wafer (W) on which the above micro-unit LED chips or semiconductor elements are arranged.

First, the first embodiment will be described with reference to FIGS. 5 and 6 .

According to <a1> of FIG. 5 , two or more LEDs may be formed on the upper surface of the first wafer W1, which is the wafer W to be inspected and transferred. At this time, each positive electrode and negative electrode of the LED is preferably formed to be exposed in the upward direction. <b1> and <c1> of FIG. 5 are diagrams illustrating the inspection step (S110) and the pick-up step (S120). Referring to <b1> and <c1> of FIG. 5 , in the inspection step (S110), it is inspected whether two or more LEDs formed on the first wafer W1 are normally operated through the LED transport device 1 as described above. can do. In detail, it is possible to inspect the normal operation of the LED by supplying power by bringing the inspection unit 110 of the LED transport device 1 to be described later into contact with the positive electrode and the negative electrode of the LED. More specifically, it is possible to select the first group LEDs L1 determined as one or more normal LEDs Lo by inspecting whether the LEDs operate normally.

After the inspection is completed, the first group LEDs L1 determined to be in normal operation may be selectively picked up through the pick-up step (S120). In detail, pickup may be performed by the pickup unit 120 of the LED transport device 1. At this time, the pick-up unit 120 may be picked up by static electricity in the first embodiment, as will be described in detail below, and may be picked up by a viscous material in another first embodiment. It is also possible to be picked up by a separate jig. Referring to <b1> of FIG. 5, a laser is applied to the lower surface of the first wafer W1 where the first group LEDs L1 to be picked up and determined to be normal are located. Only group 1 LEDs L1 may be separated from the first wafer W1 and picked up. At this time, in order to prevent the defective LEDs (Lx) from being picked up or separated from the first wafer (W1), the lower surface of the first wafer (W1) where the defective LEDs (Lx) are located is separated from being applied with a laser. It is preferable that a blocking film is additionally provided or a slit through which only the lower surface where the first group LED (L1) is located can be selectively opened is separately provided. Accordingly, it is preferable that only the first group LEDs L1 determined to be normal are selectively picked up as shown in <c1> of FIG. 5 . Although the above-described first embodiment has been described as a method of separating the first group LEDs L1 through a laser, it is also possible to separate through a separate chemical substance.

According to the first embodiment, the first group LEDs (L1) selectively picked up by the LED transfer device 1 are transferred through the transfer step (S130), as shown in <d1> and <e1> of FIG. It can be transferred to the upper surface of the tape 10 provided. In detail, the tape 10 may be a tape 10 made of a curable material, and more specifically, may be a tape 10 made of a UV curable or heat curable material. More preferably, since it is preferable that the tape 10 is provided with a UV curable resin, in this embodiment, the UV curable tape 10 will be described as an example. Specifically, as shown in <e1> of FIG. 5, in order for the first group LEDs L1 in a normal state picked up by the LED transport device 1 to be transported and disposed on the upper surface of the tape 10, the LED transport device ( One surface of the first group LED (L1) picked up by 1) may be placed in contact with the upper surface of the tape (10). Here, one surface of the LED refers to a surface in contact with the wafer (W), and the other surface refers to a surface on the wafer (W) on which the electrode is exposed in an upward direction. At this time, due to the viscosity of the tape 10, one surface of the group 1 LED (L1) may be temporarily fixed to the reference position of the tape 10, and the other surface where the electrode of the group 1 LED (L1) is exposed is picked up and After the pick-up unit 120 of the existing LED transfer device 1 finishes the pick-up, it is moved upward so that the first group LEDs L1 are finally placed on the upper surface of the tape 10 as shown in <f1> of FIG. can be transported In detail, depending on the configuration of the pickup unit 120, the aforementioned pickup termination method may vary. According to the first embodiment, when the normal LED (Lo) is picked up by static electricity in the pickup unit 120, the pickup can be terminated by cutting off the current to the pickup unit 120. However, according to the first embodiment, when the pick-up unit 120 is made of a viscous material and the first group LEDs L1 are picked up by the viscosity, the pick-up may be terminated by controlling the corresponding viscosity to decrease. there is. Therefore, when the pick-up unit 120 is made of a viscous material, it is preferable to use a material whose viscosity is removed when heat or UV is applied. Specifically, it is preferable to be provided with any one of heat-curable and UV-curable resins having viscosity before curing, or UV Resin, SU-8, and PDMS (Polydimethylsiloxane). In more detail, heat or UV is applied to the pick-up unit 120 provided with a viscous material to reduce the viscosity to terminate the pick-up of the first group LED (L1), and then the pick-up of the second group LED (L2) It is preferable that the viscosity of the pick-up unit 120 increases again when heat or UV is stopped or a separate treatment is performed. In addition, in the above-described first embodiment, the viscosity of the pick-up unit 120 is controlled, but the viscosity of the tape 10 on which the group 1 LEDs L1 are transported is the same as the viscosity of the pick-up unit 120. It is stronger and can be transported without controlling the viscosity of the separate pick-up unit 120 .

According to the first embodiment, after the first group LEDs L1 are temporarily transferred to the upper surface of the tape 10 in the transfer step (S130) as described above, the process of finally transferring them to the target substrate S is further carried out. can be added Although it may be possible that the first group LEDs L1 picked up from the first wafer W1 are directly transferred to the target substrate S, the electrodes of the LEDs can be mounted in contact with the upper surface of the target substrate S, as described above. After being temporarily transferred to the tape 10 as described above, one side and the other side of the first group LED (L1) can be reversed so that the electrode of the first group LED (L1) can be electrically connected to the target substrate (S). there is. Hereinafter, a process in which the first group LEDs L1 transferred to the tape 10 are finally transferred to the target substrate S will be described in detail with reference to <g1> and <h1> of FIG. 5 . At this time, a hard plate may be further provided on the lower surface of the tape 10 so that the first group LEDs L1 transferred to the tape 10 can be safely transferred. In detail, the hard plate may be made of a transparent material such as acrylic or glass. The first group LEDs L1 transferred to the tape 10 may be placed in contact with the upper surface of the target substrate S such that one surface and the other surface are reversed. Therefore, after the electrodes of the first group LEDs L1 are placed in contact with the upper surface of the target substrate S, the transfer of the first group LEDs L1 to the target substrate S is completed by removing the tape 10. It can be. As described above, the tape 10 is provided with a curable material having viscosity, so that one side of the first group LED (L1) is fixed by the viscosity, and when transferred to the target substrate (S), the tape 10 is removed. Separation of the first group LED (L1) can be prevented. After the first-group LEDs L1 are transferred to the target substrate S, in order to separate the tape 10, the tape 10 may be cured by applying UV or heat depending on the material of the tape, thereby removing viscosity. Preferably, the tape 10 is made of a UV curable material, and by applying UV to the tape 10, the tape 10 is cured and the viscosity can be removed. When the viscosity of the tape 10 is removed, the first group LEDs L1 are separated from the tape 10 and the transfer to the target substrate S can be completed.

According to the first embodiment, even if the transfer of the first group LEDs L1 on the first wafer W to the target substrate S is completed through <a1> to <h1> of FIG. 5, the inspection step (S110) ), the LED is not transferred to the target substrate S at a position corresponding to the position determined as the defective LED Lx on the first wafer W, so an empty space is created. Therefore, the target substrate S cannot be completed only by transferring the first group LEDs L1. In order to fill the empty space of the target substrate S, as shown in FIG. 6, a selective pick-up step (S220) and a selective transfer step (S230) of additionally transferring the second group LEDs (L2) may be further performed. The selection pick-up step (S220) and the selection transfer step (S230) of the first embodiment are performed in a manner similar to the above-described pick-up step (S120) and transfer step (S130) of the first embodiment, and only the position of the selected LED is different. So, let's focus on the different parts.

According to <a2> of FIG. 6 , a second wafer W2 which is an auxiliary wafer W having two or more LEDs formed thereon may be provided. <b2> and <c2> of FIG. 6 are views showing the selective pickup step (S220). In the selective pickup step ( S220 ), the second group LEDs L2 on the second wafer W2 may be selected and picked up. In detail, among the two or more LEDs formed on the second wafer W2, one or more normal LEDs (Lo ) is referred to as the second group LED (L2). More specifically, in the target substrate S to which the first group LEDs L1 were transferred in the transfer step (S130), the second group LEDs corresponded to the portion where an empty space was formed without being transferred due to the defective LEDs Lx. (L2) can be selectively picked up. At this time, before picking up the second group LEDs L2 on the second wafer W2, it is preferable to first inspect whether the corresponding second group LEDs L2 operate normally. After the inspection is completed, the second group LEDs L2 determined to be in normal operation may be selectively picked up through the selective pick-up step (S220). At this time, the pickup method is the same as the pickup step (S120) of picking up the first group LEDs L1 of the first embodiment described above, with the difference that only the position of the target LED to be picked up is reversed. In detail, by applying a laser to the lower surface of the second wafer W2 where the second group LEDs L2 are located, only the second group LEDs L2 can be selectively separated from the second wafer W2 and picked up. , it may be separated and picked up through a separate chemical substance. At this time, in order to prevent the LEDs in other positions from being picked up or separated from the second wafer W2, laser is not applied to the lower surface of the second wafer W2 at positions other than the second group LEDs L2. It is preferable to additionally provide a separate blocking film or separately provide a slit through which only the lower surface where the second group LED (L2) is located can be selectively opened. Accordingly, it is preferable that only the second group LEDs L2 are selectively picked up as shown in <c2> of FIG. 6 . According to the first embodiment, after the selective pick-up step (S220), the selective transfer step (S230) may be performed. At this time, the transfer method is the same as the transfer step (S130) of the first embodiment described above, after the second group LEDs (L2) picked up by the LED transfer device 1 are transferred to the tape 10, the tape 10 It can be transferred to the target substrate (S). In detail, as shown in <g2> of FIG. 6, in order to transfer the second group LED (L2) transferred to the tape 10 to the target substrate (S), the second group LED (L2) is placed on the upper surface of the target substrate (S). When the electrodes of ) are placed in contact with each other, one side of the first group LED (L1) transferred to the target substrate (S) may be adhered by the viscosity of the tape (10). To prevent this, it is preferable to remove or reduce the viscosity by applying UV or heat to the front surface of the tape 10 when the second group LEDs L2 are transferred to the target substrate S. When the selective transfer step (S230) is completed, as shown in <h2> of FIG. 6, normal LEDs (Lo) are all provided in the empty space of the target board (S) to complete the target board (S) of the good product to be provided. there is.

Hereinafter, the second to fourth embodiments to be described later through FIGS. 7 to 12 are embodiments in which parts are modified based on the first embodiment, and the same description as the first embodiment is omitted and in different parts to explain in detail.

Referring to FIGS. 7 and 8, the second embodiment is described, the first group LED (L1) and the second group LED (L2) are sequentially transferred through the same steps and procedures as in the first embodiment for the purpose of quality products. The substrate S can be completed. However, the LED transport device 1 of the second embodiment may be partially different from the first embodiment. In detail, the LED transport device 1 of the first embodiment may be provided such that the inspection unit 110 and the pickup unit 120 are exposed on the lower surface, but according to the second embodiment, the inspection unit 110 and the pickup unit 120 ) may be provided in a groove formed in an inward direction from the lower surface of the LED transport device 1. More specifically, in the LED transport device 1 of the second embodiment, two or more grooves may be provided on the lower surface so that the inspection unit 110 and the pickup unit 120 have the same protruding shapes as the LEDs formed on the wafer W. there is. For distinction from the inspection unit 110 and pickup unit 120 of the first embodiment, the inspection unit and pickup unit of the second embodiment will be described as the second inspection unit 110' and the second pickup unit 120', and FIG. 13 And with reference to Figure 14 will be described in more detail.

13 is a cross-sectional view showing the LED transport device according to the first embodiment, and FIG. 14 is a cross-sectional view showing the LED transport device according to the second embodiment. Referring to FIG. 13 , the LED transport device 1 according to the first embodiment is preferably provided such that the inspecting unit 110 and the pickup unit 120 are exposed on the lower surface as described above. In detail, the lower surface of the LED transport device 1 according to the first embodiment may be provided with a flat surface, and the normal operation of the LED may be inspected as the inspection unit 110 contacts the electrode of the LED to supply current. there is. In addition, static electricity is generated by the electrostatic unit 121 provided in the pickup unit 120 so that the LED can be picked up. On the other hand, referring to FIG. 14, the LED transport device according to the second embodiment has two or more groove-shaped second pickup parts 120' corresponding to the LEDs on the lower surface, and the inner side of the groove into which the electrodes of the LEDs are inserted. A second inspection unit 110' may be provided. Therefore, according to the second embodiment, as the LED is inserted into the groove-shaped second pickup part 120', the second inspection part 110' and the electrode of the LED come into contact, whereby the normal operation of the LED can be inspected. can Then, according to the second embodiment, the normal LED (Lo) determined to be in normal operation may be picked up by the second pickup unit 120'. In detail, static electricity may be generated by the electrostatic unit 121 provided in the upward direction of the second pickup unit 120′, and the LED may be picked up. In addition, according to the second embodiment, it can be picked up by the second pickup unit 120' made of a viscous material similar to the first embodiment. At this time, the other second embodiment is LED. is incorporated into the second pick-up part 120' and picked up, so that the area in contact with the second pick-up part 120' is wide and effective, compared to the viscous contact of only the other surface of the first embodiment.

As described above, according to the second embodiment, the order and method of each inspection step (S110), pick-up step (S120), transfer step (S130), selective pick-up step (S220) and selective transfer step (S230) are the first. It is the same as Example 1, and may be provided differently in the structure to be picked up in the LED transport device 1. Hereinafter, the third embodiment will be described in detail with reference to FIGS. 9 and 10 .

Referring to FIGS. 9 and 10 , the third embodiment is shown as the configuration of the LED transport device 1 of the second embodiment, but LED transport by the LED transport device 1 of the first embodiment is also possible. The third embodiment is generally similar to the first embodiment and the second embodiment, and has some differences in the transfer step (S130). In detail, according to the first and second embodiments, in the transfer step (S130), the first group LEDs L1 are transferred to the tape 10 and then transferred to the target substrate S. Also, in the selective transfer step (S230), the second group LEDs L2 are transferred to the tape 10 and then transferred to the target substrate S to complete the target substrate S of the final good product. However, according to the third embodiment, the target substrate S of good quality can be completed more quickly by reducing the process of one step. In detail, referring to FIG. 9 , the transfer step ( S130 ) of the third embodiment may end after the first group LEDs L1 are transferred to the tape 10 . In detail, according to the third embodiment, in the transfer step (S130), the first group LEDs (L1) are not transferred to the target substrate (S), but are transferred to the tape 10, and then the next step, the selective pick-up step (S220). ) can be done. When the transfer step (S130) of the third embodiment is finished, the second group LED (L2) can be selected and picked up from the second wafer (W2) by the selective pick-up step (S220). (L2) may be transferred to the tape 10 by the selective transfer step (S230). In detail, it is preferable that the first group LEDs L1 transferred in the transfer step S130 remain on the tape 10 to which the second group LEDs L2 are transferred in the selective transfer step S230 of the third embodiment. . In more detail, in the selective transfer step (S230) of the third embodiment, the second group LED (L2) may be further positioned in the empty space of the tape 10 where the first group LED (L1) is positioned, then, The tape 10 with all empty spaces is transferred to the target substrate S, and the first group LEDs L1 and the second group LEDs L2 may be transferred to the target substrate S at the same time. Therefore, according to the third embodiment, the step of transferring the first group LEDs (L1) to the target substrate (S) in the transfer step (S130) is omitted, and the second group LEDs (L2) are transferred in the selective transfer step (S230). By being transferred to the target substrate (S) together with, it is possible to provide a good target substrate (S) more quickly.

Hereinafter, a fourth embodiment, which is a more preferred embodiment, will be described in detail with reference to FIGS. 11 and 12 . The fourth embodiment is similar to the above-described first to third embodiments, but the order of each step is different, so <a`1> to <h`1> and <a`2> to <h`2> to explain the order.

According to <a`1> of FIG. 11, two or more LEDs may be formed on the upper surface of the first wafer W1, which is the wafer W to be inspected and transferred. Thereafter, according to the fourth embodiment, before the inspection step (S110), a step of transferring all the LEDs formed on the upper surface of the first wafer (W1) to the tape 10 may be further performed. In the above-described first to third embodiments, the LEDs are selectively transferred to the tape 10 after inspection through the LED transfer device 1 on the first wafer W1, but in the fourth embodiment, the first wafer ( Through the inspection step (S110) on W1), the first group LEDs (L1), which are normally operating LEDs, are inspected, but the entire first group LEDs (L1) are not selectively picked up on the first wafer (W1). The LEDs can all be transferred onto the tape (10). Thereafter, in the transfer step (S120), only the LEDs specified as the first group LEDs L1 on the tape 10 can be selectively picked up and transferred as shown in <d`1> to <f`1> of FIG. 11 .

In the fourth embodiment described above, specifying the first group LEDs L1 in advance on the first wafer W1 has been described as an embodiment, but according to another fourth embodiment, the first wafer W1 is not inspected. ) After transferring all the LEDs on the tape 10, each LED on the tape 10 can be inspected. In detail, referring to <b`1> and <c`1> of FIG. 11, in the fourth embodiment, after contacting one surface of two or more LEDs formed on the first wafer W1 with the tape 10, All of the LEDs on the first wafer W1 may be transferred to the tape 10 by irradiating a laser onto the entire lower surface of the first wafer W1 or through a separate chemical treatment. Then, referring to <d`1> to <f`1> of FIG. 11, the inspection step (S110) and the pick-up step (S120) according to the fourth embodiment of the present invention will be described. In the fourth embodiment, the tape ( 10) It is possible to selectively pick up two or more LEDs transferred onto the LED transport device 1 by examining the photoelectric characteristics of each LED. At this time, it is preferable to irradiate UV only on the lower surface where the first group LED (L1) to be picked up is located so that only the first group LED (L1) can be picked up. The picked up group 1 LEDs L1 may be transferred to the target substrate S as shown in <g`1> and <h`1> of FIG. 11 . Then, referring to FIG. 12, the selective pick-up step (S220) and the selective transfer step (S230) of the fourth embodiment may be performed in a process similar to the above-described pick-up step (S120) and transfer step (S130). In more detail, as shown in <b`2> and <c`2> of FIG. 12 before the selective pick-up step (S220), all of the two or more LEDs formed on the second wafer W2 are transferred to the tape 10. Steps may be added. Thereafter, as shown in <d`2> to <h`2> of FIG. 12, among the LEDs transferred to the tape 10, the second group LEDs (L2) disposed at positions other than the position of the first group LEDs (L1) It can be picked up only and transferred to the target substrate (S). At this time, the target substrate (S) to which the second group LED (L2) is transferred is the target substrate (S) to which the first group LED (L1) is transferred in the transfer step (S130), and the second group LED ((L2) By being transferred to the empty space, the target substrate S of good quality can be completed.

Additionally, referring to FIGS. 11 and 12, the LED transport device 1 is provided with an inspection unit 110 and a pick-up unit 120 at positions corresponding to each LED, unlike the above described with reference to FIGS. 13 and 14. It can be. As described above through FIG. 13, the LED transport device 1 may be provided such that the inspection unit 110 and the pickup unit 120 are exposed on the lower surface, but the inspection unit 110 and the pickup unit ( 120) may be provided so as to protrude downward. At this time, the inspection and pick-up method is the same as the method described above with reference to FIG. 13, so it is omitted.

In the above-described embodiment and the first to fourth embodiments, the first group LED pick-up and transfer step (S100) and the second group LED pick-up and transfer step (S200) correspond to positions other than the first group LED. The process of simultaneously picking up and transferring the second group of LEDs to be used has been described. Hereinafter, with reference to FIGS. 15 and 16, an LED pick-up and transfer method of one embodiment and another embodiment will be described in detail. 15 is a diagram showing an LED transfer method according to one embodiment, and FIG. 16 is a diagram showing an LED transfer method according to another embodiment.

According to the embodiment described above with reference to FIG. 15 , after the transfer step (S130) of transferring the group 1 LEDs L1 on the first wafer (W1) to the target substrate (S), the selective transfer step (S230) is performed. Through this, the second group LEDs L2 corresponding to the empty space of the target substrate S may be simultaneously picked up and transferred from the second wafer W2. That is, the normal LEDs Lo on the second wafer W2 corresponding to all positions except for the position of the first group LEDs L1 on the target substrate S can be simultaneously selected and transferred. In detail, in the selective transfer step (S230) of the above-described embodiment, after transferring the first group LEDs (L1), two or more second group LEDs (L2) corresponding to the empty space of the target substrate (S) are simultaneously picked up and Although described as an embodiment of transferring, in another embodiment below, the selective transfer step (S230) is repeated twice or more, and some of the second group LEDs (L2) corresponding to the empty space are selectively transferred one by one or two or more. can Hereinafter, another embodiment will be described in detail with reference to FIG. 16 .

According to another embodiment of FIG. 16, after the transfer step (S130) of transferring the group 1 LEDs L1 on the first wafer W1 to the target substrate S, the second wafer W2, which is an auxiliary wafer, is normal. The selection transfer step (S230) of selecting and transferring the LED (Lo) to an empty space of the target substrate (S) may be performed several times. More specifically, in one embodiment, the second group LEDs L2 at positions corresponding to the empty space of the target substrate S are simultaneously picked up and transferred from the second wafer W2, but according to another embodiment, the target substrate Even if the position does not correspond to the empty space of (S), the normal LED (Lo) on the second wafer (W2) can be selected and selectively transferred to the empty space of the target substrate (S). That is, in one embodiment, among the LEDs formed on the second wafer W2, the second group LEDs L2 formed at locations other than those corresponding to the first group LEDs L1 may be simultaneously selected and transferred. According to another embodiment, only one or more normal LEDs (Lo) are selected to be applied to the first group LEDs (L1) on the target substrate (S), regardless of any position of the LEDs formed on the second wafer (W2). It can be transferred to a location other than the corresponding location. Specifically, referring to FIG. 16 , after the transfer step (S130) of transferring group 1 LEDs (L1) to the target substrate (S), the empty space of the target substrate (S) is performed through the first selective transfer step (S230′). Normal LEDs (Lo) corresponding to some of them may be selectively picked up from the second wafer (W2) and transferred. Here, the empty space refers to a position excluding the position corresponding to the first group LED (L1). In addition, through the second selective transfer step (S230``), the normal LED (Lo) corresponding to a part of the empty space of the target substrate (S) remaining after the first selective transfer step (S230') is transferred to the second wafer (W2). ) can be selectively picked up and transported additionally. After the second selective transfer step (S230``), the normal LED (Lo) is additionally transferred to the empty space of the remaining target substrate (S) through the third selective transfer step (S230````) to the target substrate of the good product ( S) can be completed. In the other embodiment described above, in the first selective transfer step (S230`) to the third selective transfer step (S230```), the normal LED (Lo) transferred to the target substrate (S) is transferred to the same second wafer (W2). Although the above selection has been described as an example, it is not necessary to repeat the selection transfer step (S230) on the same auxiliary wafer, and each of the first selection transfer step (S230`) to the third selection transfer step (S230```) Normal LEDs (Lo) may be selectively transferred from different auxiliary wafers. In addition, in the other embodiment described above, although the selection transfer step (S230) is repeated three times, it may be performed twice or three times or more, and in each selection transfer step (S230), the normal LED (Lo) You can select and transfer one by one. Alternatively, two or more normal LEDs (Lo) may be selected and transferred as a group to correspond to the empty space of the target substrate (S). That is, two or more normal LEDs (Lo) on the second wafer (W2) corresponding to two or more positions among positions excluding the position of the first group LED (L1) on the target substrate (S) can be simultaneously selected and transferred. . In addition, the normal LED (Lo) selected and transferred in the selection transfer step (S230) does not necessarily need to be selected from a position corresponding to the position of the empty space of the target substrate (S), and the normal LED (Lo) on the second wafer (W2) Lo) can be picked up at any position of the LED. Specifically, it is only necessary to pick up some of the LEDs located at any position among the normal LEDs Lo on the second wafer W2 and then transfer them to the empty space of the target substrate S.

The present invention described above has been described with reference to preferred embodiments, but these are only examples, and various modifications and other equivalent embodiments may be made by those skilled in the art. Therefore, the scope of the present invention is not limited by the above embodiments and the accompanying drawings.

1: LED transport device 10: tape
W1: first wafer W2: second wafer
Lo: OK LED Lx: Bad LED
L1: 1st group LED L2: 2nd group LED
S: target substrate
110: inspection unit 120: pickup unit

Claims (12)

In the method of transferring the LED on the wafer (W),
Among the LEDs formed on the first wafer (W1), only the first group LEDs (L1) are selected and transferred to the target substrate (S);
A position excluding the position corresponding to the first group LED (L1) on the target substrate (S) by selecting only the second group LED (L2), which is one or more normal LEDs (Lo), among the LEDs formed on the second wafer (W2). transfer to
The first group LED (L1),
The normal LED (Lo) determined to be normal through the inspection step (S110) of inspecting whether the LED formed on the first wafer (W1) is normally operating,
The second group LED (L2),
Among the LEDs formed on the second wafer (W2), a normal LED (Lo) at a position corresponding to a position determined as a defective LED (Lx) of the first wafer (W1) in the inspection step (S110),
In the inspection step (S110),
By inspecting photoelectric characteristics generated by supplying power to the LED formed on the first wafer (W1), it is determined whether the LED operates normally;
The inspection and transfer,
It is made by the LED transport device 1 including the inspection unit 110 and the pickup unit 120,
The pickup part has a groove shape corresponding to the LED,
An inspection unit is provided inside the groove into which the electrode of the LED is inserted,
The pickup unit 120,
Having a viscous material, characterized in that the pick-up is made by the viscous, LED transport method.
According to claim 1,
When selecting only one or more normal LEDs (Lo) among the LEDs formed on the second wafer (W2),
Characterized in that two or more normal LEDs (Lo) on the second wafer (W2) corresponding to two or more positions among positions other than the position of the first group LED (L1) on the target substrate (S) are simultaneously selected and transferred LED transfer method.
According to claim 1,
When selecting only one or more normal LEDs (Lo) among the LEDs formed on the second wafer (W2),
LED transfer method characterized by simultaneously selecting and transferring normal LEDs (Lo) on the second wafer (W2) corresponding to all positions except for the position of the first group LED (L1) on the target substrate (S).
delete delete delete delete According to claim 1,
Before selecting and transferring only the first group LED (L1),
A pick-up step (S120) of picking up the first group LED (L1); further comprising,
The pick-up step (S120); is,
The LED transport device 1 is positioned so as to be in contact with two or more LEDs formed on the first wafer W1, and UV is applied to the lower surface of the first wafer W1 where the first group LEDs L1 are located. LED transfer method characterized in that only the first group LED (L1) is separated from the first wafer (W1) and picked up.
delete delete According to claim 8,
The viscous material is
LED transfer method characterized in that UV Resin.
According to any one of claims 8 and 11,
In the pick-up step (S120),
The LED transport method, characterized in that the first group LED (L1) is picked up so as to be recessed into the pickup part (120) of the LED transport device (1).

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