KR102600183B1 - Method of transferring Semiconductor Device - Google Patents

Abstract

The present invention provides a process for forming a release layer on a carrier substrate and forming a semiconductor device on the release layer; Process of preparing a base substrate; A process of positioning the carrier substrate on the base substrate so that the semiconductor device faces the base substrate; and a step of irradiating a laser beam on the carrier substrate to separate the semiconductor device from the release layer and seat it on the base substrate, wherein the step of irradiating the laser beam is performed using a laser having at least one laser pulse. Provided is a method of transferring a semiconductor device including a step of irradiating a beam to the release layer after passing through the carrier substrate, causing the area of the release layer irradiated with the laser beam to swell and detaching from the carrier substrate.

Description

Method of transferring semiconductor device {Method of transferring Semiconductor Device}

The present invention relates to a method for transferring semiconductor devices.

In the case of relatively large-sized semiconductor devices such as light emitting devices (LEDs), a transfer method is used to attach and mount them at the desired location of an electronic device such as a display device using a vacuum-type pick and place device. This is relatively easy.

However, in the case of fine-sized semiconductor devices such as micro LEDs, a new transfer method is required because the transfer method using a conventional pick and place device is not possible.

The present invention was designed to solve the above-described conventional problems, and its purpose is to provide a new method for transferring micro-sized semiconductor devices to a desired location on the base substrate of various types of electronic devices.

In order to achieve the above-described object, the present invention includes a process of forming a release layer on a carrier substrate and forming a semiconductor device on the release layer; Process of preparing a base substrate; A process of positioning the carrier substrate on the base substrate so that the semiconductor device faces the base substrate; and a step of irradiating a laser beam on the carrier substrate to separate the semiconductor device from the release layer and seat it on the base substrate, wherein the step of irradiating the laser beam is performed using a laser having at least one laser pulse. Provided is a method of transferring a semiconductor device including a step of irradiating a beam to the release layer after passing through the carrier substrate, causing the area of the release layer irradiated with the laser beam to swell and separate from the carrier substrate.

According to the present invention, by irradiating a laser beam having at least one laser pulse to swell the area of the release layer irradiated with the laser beam, the semiconductor element attached to the release layer is separated from the release layer and released into the base of the electronic device. The semiconductor device can be transferred to a desired location on the substrate.

1A to 1G are cross-sectional process views showing a method for transferring a semiconductor device according to an embodiment of the present invention.
FIGS. 2A to 2D are cross-sectional views showing an example of the process of FIG. 1F, showing a process of separating a semiconductor element bonded to a release layer from the release layer through irradiation of a laser beam and seating it on the lower conductive adhesive layer. This is a cross-sectional view of the process.
3A to 3E are diagrams showing laser pulses according to various embodiments of the present invention.
FIGS. 4A and 4B illustrate the release layer being separated from the carrier substrate by irradiation of a laser beam according to various embodiments of the present invention.
Figures 5A to 5D illustrate a laser beam irradiation process according to various embodiments of the present invention.
6A to 6D illustrate a semiconductor device transfer process according to another embodiment of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. These embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are illustrative, and the present invention is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a positional relationship, for example, if the positional relationship of two parts is described as 'on top', 'on the top', 'on the bottom', 'next to', etc., 'immediately' Alternatively, there may be one or more other parts placed between the two parts, unless 'directly' is used.

In the case of a description of a temporal relationship, for example, if a temporal relationship is described as 'after', 'successfully after', 'after', 'before', etc., 'immediately' or 'directly' Unless used, non-consecutive cases may also be included.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from another. Accordingly, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Each feature of the various embodiments of the present invention can be combined or combined with each other, partially or entirely, and various technological interconnections and operations are possible, and each embodiment can be implemented independently of each other or together in a related relationship. It may be possible.

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

1A to 1G are cross-sectional process views showing a method for transferring a semiconductor device according to an embodiment of the present invention.

First, as can be seen in FIG. 1A, the semiconductor substrate 200a is placed on the support film 100.

The support film 100 is a support layer for dicing the semiconductor substrate 200a, and the semiconductor substrate 200a is attached to the support film 100.

The semiconductor substrate 200a may be made of a wafer, and a plurality of semiconductor devices are formed on the wafer. The semiconductor device may be formed of various devices such as LEDs or semiconductor chips.

Each of the plurality of semiconductor devices includes at least one pad and is electrically connected to a pad provided on a circuit board or base board of various electronic devices. The pad provided on the semiconductor device is provided on the lower surface of the semiconductor substrate 200a and may be in contact with the support film 100.

Next, as can be seen in FIG. 1B, a dicing process is performed on the semiconductor substrate 200a to separate it into a plurality of semiconductor devices 200. The dicing process is performed by various methods known in the art. Accordingly, a plurality of semiconductor devices 200 are provided on the support film 100.

Next, as can be seen in FIG. 1C, a release layer 400 is formed on the carrier substrate 300, and the support film ( 100) is placed on the carrier substrate 300, and then the plurality of semiconductor devices 200 are attached on the release layer 400.

The carrier substrate 300 may be made of glass, but is not necessarily limited thereto.

The release layer 400 has an adhesive force capable of attaching the plurality of semiconductor elements 200 at room temperature, and in the laser irradiation process described later, the release layer 400 swells by the irradiated laser beam and attaches the plurality of semiconductor elements 200 to the release layer 400. ) is made of a material that can escape.

Next, as can be seen in FIG. 1D, the support film 100 is removed from the semiconductor device 200. Accordingly, although not shown, a pad is exposed on the semiconductor device 200.

Next, as can be seen in FIG. 1E, a plurality of conductive adhesive layers 600 are formed on the base substrate 500, and the plurality of semiconductor devices 200 are placed on the carrier substrate so that the plurality of semiconductor devices 200 face the plurality of conductive adhesive layers 600. (300) is placed on the base substrate (500).

The base board 500 may be made of a PCB (Printed Circuit Board) on which a circuit is mounted, or may be made of glass or plastic. The semiconductor device 200 according to the present invention may be made of an LED used in a display device, lighting device, or various health care devices, and in this case, the base substrate 500 may be the base of each electronic device. there is. The semiconductor device 200 according to the present invention may be made of a semiconductor chip of various electronic devices.

Although not shown, at least one pad is formed on the upper surface of the base substrate 500, and the conductive adhesive layer 600 is formed on the at least one pad. At this time, the conductive adhesive layer 600 may be formed to correspond one-to-one with at least one pad provided on the base substrate 500. The conductive adhesive layer 600 may be made of solder, but is not necessarily limited thereto.

The plurality of semiconductor devices 200 are positioned to be spaced apart from the plurality of conductive adhesive layers 600 at a predetermined distance without being in contact with the plurality of conductive adhesive layers 600 . That is, the plurality of semiconductor devices 200 are positioned above the plurality of conductive adhesive layers 600 without contacting them.

The plurality of conductive adhesive layers 600 may face the plurality of semiconductor devices 200 and overlap the plurality of semiconductor devices 200 .

Each of the plurality of semiconductor devices 200 is provided with at least one pad, and the conductive adhesive layer 600 is provided on at least one pad of the plurality of semiconductor devices 200 and the base substrate 500. It serves to electrically connect and bond at least one pad. Accordingly, the pads provided in the semiconductor device 200, the conductive adhesive layer 600, and the pads provided in the base substrate 500 are provided in the same number and at corresponding positions.

Although the drawing shows one conductive adhesive layer 600 being formed at a position corresponding to one semiconductor device 200, when a plurality of pads are formed on the one semiconductor device 200, the base substrate ( A plurality of pads and a plurality of conductive adhesive layers 600 are also formed at corresponding positions of 500).

Next, as can be seen in FIG. 1F, a laser beam is irradiated on the carrier substrate 300. Then, after the laser beam passes through the carrier substrate 300, it is irradiated to the release layer 400, and accordingly, the semiconductor device 200 is adhered to the release layer 400 to which the laser beam has been irradiated. ) leaves the release layer 400. The semiconductor device 200 that is separated in this way freely falls and is seated on the conductive adhesive layer 600 below it.

The process of FIG. 1f is described in more detail as follows.

FIGS. 2A to 2D are cross-sectional views showing an embodiment of the process of FIG. 1F, which includes a process of separating a semiconductor element bonded to a release layer from the release layer through irradiation of a laser beam and seating it on the lower conductive adhesive layer. This is a cross-sectional view of the process. For reference, only one semiconductor device 200 is shown in FIGS. 2A to 2D for convenience.

First, as can be seen in FIG. 2A, a first pad 510 and a second pad 520 are formed on the upper surface of the base substrate 500, and the first pad 510 and the second pad 520 are respectively A conductive adhesive layer 600 is formed on the upper surface of . The number of pads 510 and 520 may vary.

In addition, a release layer 400 is formed on the lower surface of the carrier substrate 300, and a semiconductor device 200 is attached to the lower surface of the release layer 400. A first pad 210 and a second pad 220 are formed on the lower surface of the semiconductor device 200 facing the conductive adhesive layer 600. The number of pads 210 and 220 may vary.

The first pad 210 of the semiconductor device 200 faces the first pad 510 of the base substrate 500, and the second pad 220 of the semiconductor device 200 faces the base substrate 500. ) is facing the second pad 520. The first pad 210 and the second pad 220 of the semiconductor device 200 face each other while being spaced apart from the conductive adhesive layer 600 .

Next, as can be seen in FIG. 2B, a laser beam is irradiated on the carrier substrate 300. Then, after the laser beam passes through the carrier substrate 300, it is irradiated to the release layer 400, and the area of the release layer 400 to which the laser beam is irradiated deviates from the carrier substrate 300. It swells while doing so.

In particular, the first region of the release layer 400 corresponding to the center of the laser beam deviates further from the carrier substrate 300 than the second region of the release layer 400 corresponding to the periphery of the laser beam. It swells while doing so.

Accordingly, the semiconductor device 200 is released from adhesion to the second region of the release layer 400 and adheres only to the first region of the release layer 400, and eventually, as shown in FIG. 2C, the release layer ( The adhesion to the first area of 400 is also released, leaving the release layer 400 and falling freely. That is, as the contact area between the semiconductor device 200 and the release layer 400 decreases, the semiconductor device 200 is separated from the release layer 400.

Accordingly, the semiconductor device 200 that freely falls as shown in FIG. 2D is seated on the conductive adhesive layer 600. That is, the first pad 210 of the semiconductor device 200 is in contact with the conductive adhesive layer 600 on the first pad 510 of the base substrate 500, and the second pad ( 220 is in contact with the conductive adhesive layer 600 on the second pad 520 of the base substrate 500.

Next, referring again to FIG. 1G, the above-described process of FIG. 1F is repeatedly performed to seat the plurality of semiconductor devices 200 on the plurality of conductive adhesive layers 600.

However, it is not necessarily limited thereto, and during the process of FIG. 1F, a plurality of semiconductor devices 200 may be formed using a plurality of laser irradiation devices or a laser irradiation device with a large area beam. 600) It is also possible to place them on the same stage.

Thereafter, a plurality of semiconductor devices 200 are adhered to the plurality of conductive adhesive layers 600 through a heating process. The adhesion process may be performed by a laser irradiation process or a heating process in a high temperature chamber, but is not necessarily limited thereto.

3A to 3E are diagrams showing laser pulses according to various embodiments of the present invention. FIGS. 3A to 3E show various examples of laser pulses during the laser irradiation process performed in the process of FIG. 2B described above.

As shown in FIG. 3A, the laser irradiation process may be performed with one laser pulse of a predetermined intensity.

Alternatively, as shown in FIG. 3B, the laser irradiation process may be performed with a plurality of laser pulses of the same cycle and with the same predetermined intensity. That is, in FIG. 3B, the intensity of each laser pulse may be the same and the intervals D1 and D2 between each laser pulse may be the same. In the case of FIG. 3B, the semiconductor device 200 can be more easily separated from the release layer 400 in the above-described processes of FIGS. 2B to 2C compared to the case of FIG. 3A.

Alternatively, as shown in FIG. 3C, the laser irradiation process may be performed with a plurality of laser pulses of the same period and having different intensities. That is, in Figure 3c, the intensity of each laser pulse is different, and in particular, the intensity of the second laser pulse may be greater than the intensity of the first laser pulse, and the intensity of the third laser pulse may be greater than the intensity of the second laser pulse. Accordingly, the semiconductor device 200 can be more easily separated from the release layer 400 in the above-described processes of FIGS. 2B to 2C. Additionally, in FIG. 3C, the intervals D1 and D2 between each laser pulse may be the same.

Alternatively, as shown in FIG. 3D, the laser irradiation process may be performed with a plurality of laser pulses of different cycles and with the same predetermined intensity. That is, in FIG. 3D, the intensity of each laser pulse is the same and the intervals D1 and D2 between each laser pulse may be different. At this time, by making the gap (D1) between the first and second laser pulses smaller than the gap (D2) between the second and third laser pulses, the release layer 400 is a carrier in the process of FIG. 2b described above. It can be more easily separated from the substrate 300.

Alternatively, as shown in FIG. 3E, the laser irradiation process may be performed with a plurality of laser pulses having different intensities and different periods. That is, in Figure 3e, the intensity of each laser pulse is different, and in particular, the intensity of the second laser pulse may be greater than the intensity of the first laser pulse, and the intensity of the third laser pulse may be greater than the intensity of the second laser pulse. Accordingly, the semiconductor device 200 can be more easily separated from the release layer 400 in the above-described processes of FIGS. 2B to 2C. In addition, in Figure 3e, the intervals (D1, D2) between each laser pulse are different from each other, and specifically, the interval (D1) between the first and second laser pulses is different from the second and third laser pulses. By making it smaller than the distance D2, the release layer 400 can more easily separate from the carrier substrate 300 in the process of FIG. 2b described above.

FIGS. 4A and 4B illustrate the release layer 400 being separated from the carrier substrate 300 by irradiation of a laser beam according to various embodiments of the present invention.

As shown in FIG. 4A, the distance H1 at which the release layer 400 deviates from the carrier substrate 300 may be adjusted to be relatively small, and as shown in FIG. 4B, the release layer 400 deviates from the carrier substrate 300. One distance (H1) may be adjusted to be relatively large.

By variously changing the intensity and period of the laser pulse as shown in FIGS. 3A to 3E described above, the release layer 400 can be separated from the carrier substrate 300 in the form shown in FIG. 4A or 4B.

Figures 5A to 5D illustrate a laser beam irradiation process according to various embodiments of the present invention.

As shown in FIG. 5A, when a laser beam is irradiated on the carrier substrate 300 to separate the release layer 400 from the carrier substrate 300, the focus f of the laser beam is focused on the carrier substrate 300 and the release layer ( 400) can be adjusted to the interface. In this way, when the focus (f) of the laser beam is adjusted to the interface of the carrier substrate 300 and the release layer 400, the initial separation of the release layer 400 becomes more smooth, but the laser beam and the release layer ( Since the overlap area between 400 is relatively small, the width W1 at which the release layer 400 is separated from the carrier substrate 300 may be relatively small. Therefore, the process of FIG. 5A can be used to transfer relatively small-sized semiconductor devices.

5B and 5C, when a laser beam is irradiated on the carrier substrate 300 to separate the release layer 400 from the carrier substrate 300, the focus f of the laser beam is focused on the carrier substrate 300 and the release layer 400. It can be tailored to parts other than the interface of the release layer 400.

As shown in Figure 5b, when the release layer 400 is separated from the carrier substrate 300 by irradiating a laser beam on the carrier substrate 300, the focus f of the laser beam is aligned below the carrier substrate 300. You can. In this way, when the focus (f) of the laser beam is set to the bottom of the carrier substrate 300, the overlap area between the laser beam and the release layer 400 becomes relatively large, so that the release layer 400 is formed on the carrier substrate ( The width W2 deviating from 300) may be relatively large. Therefore, the process of FIG. 5B can be used when transferring a relatively large-sized semiconductor device.

As shown in FIG. 5C, when a laser beam is irradiated on the carrier substrate 300 to separate the release layer 400 from the carrier substrate 300, the focus f of the laser beam is focused on the upper surface of the carrier substrate 300 or higher. It can be adjusted to the top. In this way, when the focus f of the laser beam is set on the top surface of the carrier substrate 300 or above, the overlap area between the laser beam and the release layer 400 becomes relatively large, so that the release layer 400 is The width W3 separated from the carrier substrate 300 may be relatively large. Accordingly, the process of FIG. 5C can be used when transferring a relatively large-sized semiconductor device.

As shown in FIG. 5D, when a laser beam is irradiated on the carrier substrate 300 to separate the release layer 400 from the carrier substrate 300, the focus f of the laser beam can be changed. For example, the release layer 400 can be more easily separated from the carrier substrate 300 by moving the focus f of the laser beam up and down in the order of FIGS. 5A, 5B, 5A, and 5C described above. .

FIGS. 6A to 6D illustrate a semiconductor device transfer process according to another embodiment of the present invention, which is different from the process of FIGS. 2A to 2D described above in that the configuration of the release layer 400 is changed.

As can be seen in FIGS. 6A to 6D, according to another embodiment of the present invention, the release layer 400 includes a light-to-heat conversion layer 410 and an adhesive layer 420.

As can be seen in FIG. 6A, the light-to-heat conversion layer 410 is in contact with the carrier substrate 300, and the adhesive layer 420 is in contact with the semiconductor device 200.

The light-to-heat conversion layer 410 includes a material that can swell and separate from the carrier substrate 300 in response to heat generated by irradiation of a laser beam. The adhesive layer 420 is provided between the light-to-heat conversion layer 410 and the semiconductor device 200, and adheres the semiconductor device 200.

As can be seen in Figure 6b, when a laser beam is irradiated, the area of the light-to-heat conversion layer 410 to which the laser beam is irradiated deviates from the carrier substrate 300, and at this time, a predetermined area of the adhesive layer 420 is also separated. They are separated from the carrier substrate 300 together.

Accordingly, as shown in FIG. 6C, the contact area between the adhesive layer 420 and the semiconductor device 200 is reduced, so that the semiconductor device 200 separates from the adhesive layer 420 and falls freely, ultimately, As shown in Figure 6d, it is seated on the conductive adhesive layer 600.

Meanwhile, in order to allow the semiconductor device 200 to more easily separate from the adhesive layer 420, a heating process may be added before the laser beam irradiation process of FIG. 6B, for example, in the process of FIG. 6A. . That is, the adhesive force of the adhesive layer 420 can be weakened by adding a heating process before the laser beam irradiation process.

Specifically, by heating the adhesive layer 420 at a temperature of 50 to 150 ° C. for 1 to 30 seconds, the adhesive strength of the adhesive layer 420 can be weakened while preventing damage to the light-to-heat conversion layer 410. there is. If the heating process is less than 50°C or less than 1 second, the effect of weakening the adhesive strength of the adhesive layer 420 cannot be obtained, and if the heating process exceeds 150°C or longer than 30 seconds, the light-to-heat conversion layer 410 ) may be damaged.

It may be desirable to have the adhesive force of the adhesive layer 420 in the range of 1 to 200 gf through the heating process so that the semiconductor device 200 can be more easily separated from the adhesive layer 420. If the adhesive force of the adhesive layer 420 is less than 1 gf, the semiconductor device 200 may be separated from the adhesive layer 420 before the process of FIG. 6B, and if the adhesive force of the adhesive layer 420 exceeds 200 gf If so, the semiconductor device 200 may not be separated from the adhesive layer 420 in the processes of FIGS. 6B and 6C.

Although embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made without departing from the technical spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of protection of the present invention should be interpreted in accordance with the claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

100: support substrate 200a: semiconductor substrate
200: semiconductor elements 210, 220: first pad, second pad
300: carrier substrate 400: release layer
410: Light-to-heat conversion layer 420: Adhesive layer
500: base substrate 510, 520: first pad, second pad
600: Conductive adhesive layer

Claims (11)

A process of forming a release layer on a carrier substrate and forming a semiconductor device on the release layer;
Process of preparing a base substrate;
A process of positioning the carrier substrate on the base substrate so that the semiconductor device faces the base substrate; and
A process of irradiating a laser beam on the carrier substrate to separate the semiconductor device from the release layer and seat it on the base substrate,
In the process of irradiating the laser beam, a laser beam having at least one laser pulse passes through the carrier substrate and is then irradiated to the release layer to swell the area of the release layer irradiated with the laser beam to separate the laser beam from the carrier substrate. Including a process of disengaging,
The process of swelling the area of the release layer to separate it from the carrier substrate is such that the first area of the release layer corresponding to the center of the laser beam is larger than the second area of the release layer corresponding to the periphery of the laser beam. It swells as it deviates further from the carrier substrate,
The laser beam irradiation process is performed with a plurality of laser pulses of different periods, and at this time, the interval between the first laser pulse and the second laser pulse is smaller than the interval between the second laser pulse and the third laser pulse. Transcription method. According to claim 1,
A method of transferring a semiconductor device in which the laser beam irradiation process is performed using a plurality of laser pulses having the same intensity. According to claim 1,
The laser beam irradiation process is performed with a plurality of laser pulses having different intensities, and in this case, the intensity of the second laser pulse is greater than the intensity of the first laser pulse. delete delete According to claim 1,
A method of transferring a semiconductor device, wherein the laser beam irradiation process includes focusing the laser beam on an interface between the carrier substrate and the release layer. According to claim 1,
A method of transferring a semiconductor device, wherein the laser beam irradiation process includes focusing the laser beam on a portion other than the interface between the carrier substrate and the release layer. According to claim 1,
A method of transferring a semiconductor device, wherein the laser beam irradiation process includes a process of moving the focus of the laser beam up and down. According to claim 1,
The release layer includes a light-to-heat conversion layer in contact with the carrier substrate and an adhesive layer in contact with the semiconductor device,
A method of transferring a semiconductor device in which a predetermined region of the light-to-heat conversion layer swells and separates from the carrier substrate by irradiation of the laser beam. According to clause 9,
A method of transferring a semiconductor device further comprising a process of weakening the adhesive force of the adhesive layer before the laser beam irradiation process. According to claim 10,
The process of weakening the adhesive force of the adhesive layer is to heat the adhesive layer at a temperature of 50 to 150 ° C. for 1 to 30 seconds so that the adhesive force of the adhesive layer is in the range of 1 to 200 gf. A method of transferring a semiconductor device.

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