Apparatus for temporary bonding of substrate on a carrier and method thereof

An apparatus for temporarily bonding a substrate on a carrier includes an electrically conductive adhesion layer disposed between the carrier and the substrate, and a current supply source configured to apply a current to the electrically conductive adhesion layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2013-0075576 filed on Jun. 28, 2013, the disclosure of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

Exemplary embodiments of the present invention relate to temporarily bonding a substrate on a carrier, and more particularly, to an apparatus for temporarily bonding a substrate on a carrier, and a method therefor.

DISCUSSION OF THE RELATED ART

Plastic and thin glass materials are being more commonly used for flexible displays due to their low thermal resistance. Additional steps performed during a low temperature polysilicon (LTPS) process such as, for example, transferring a thin film transistor (TFT), may be performed during fabrication.

SUMMARY

Exemplary embodiments of the present invention provide an apparatus and a method for temporarily bonding and delaminating a substrate on a carrier.

Moreover, exemplary embodiments of the present invention provide an apparatus and a method for temporarily bonding and delaminating a substrate on a carrier in a case in which a flexible material and a rigid carrier are heated to a temperature of about 300° C. or higher.

According to an exemplary embodiment of the present invention, an apparatus for temporarily bonding a substrate on a carrier includes an electrically conductive adhesion layer disposed between the carrier and the substrate, and a current supply source configured to apply a current to the electrically conductive adhesion layer.

According to an exemplary embodiment of the present invention, a method for temporarily bonding a substrate on a carrier includes forming an electrically conductive adhesion layer on a surface of the carrier, laminating the substrate on the electrically conductive adhesion layer, applying a current to the electrically conductive adhesion layer to heat the electrically conductive adhesion layer, and delaminating the substrate from the surface of the carrier by breaking a bond formed by the adhesive of the electrically conductive adhesion layer.

According to an exemplary embodiment of the present invention, a semiconductor device includes a substrate and a carrier. The carrier is configured to be coupled to the substrate via an electrically conductive adhesion layer disposed between the substrate and the carrier. The electrically conductive adhesion layer is configured to receive a current supplied by a current supply source.

According to exemplary embodiments of the present invention, a flexible substrate may be bonded to a carrier in a sufficiently strong manner using an electrically conductive adhesive that permits the two layers to be separated from each other by applying a high voltage for a short period of time after a heat treatment.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings. Like reference numerals may refer to like elements throughout the accompanying drawings.

It will be understood that when an element or layer is referred to as being “on”, “connected to”, “coupled to”, or “adjacent to” another element or layer, it can be directly on, connected, coupled, or adjacent to the other element or layer, or intervening elements or layers may be present.

FIG. 1is a schematic diagram showing an apparatus for temporarily bonding and delaminating a substrate on a carrier, according to an exemplary embodiment of the present invention.

Referring toFIG. 1, the apparatus1for temporarily bonding and delaminating the substrate4on the carrier2in accordance with an exemplary embodiment may include an adhesion layer10disposed between the carrier2and the substrate4, and a current supply source30configured to apply a current to the adhesion layer10. Herein, the substrate4may be referred to as a flexible substrate4. Further, reference to temporarily bonding the substrate4on the carrier2is made with regards to bonding the substrate4on the carrier2in a non-permanent manner in which the substrate4may be delaminated from the carrier2without damaging the substrate4. The apparatus1may be used to fabricate a semiconductor device including, for a example, a display device including the substrate4.

The carrier2may be, for example, a rigid carrier. According to an exemplary embodiment, the carrier2may be formed to have a panel shape such that the substrate4can be delaminated from the carrier2after being attached thereto in a state in which the adhesion layer10is applied to a top surface of the carrier2.

Although the carrier2may be a rigid carrier, the carrier is not limited thereto. For example, the carrier may be any material and may have any configuration and shape that is capable of providing a holding means permitting a flexible substrate to be delaminated from the holding means to be subjected to a following process subsequent to being subjected to a previous process (e.g., a low temperature polysilicon (LTPS) process), in a state in which the flexible substrate is laminated on a top surface of the holding means.

The adhesion layer10is formed on the carrier2. In an exemplary embodiment, the adhesion layer10may be formed as an electrically conductive adhesion layer using an electrically conductive adhesive having temperature resistance. Herein, the adhesion layer10may be referred to as an electrically conductive adhesion layer10.

The adhesion layer10may include an adhesive such as, for example, an epoxy or a polyimide-based resin, however the material of the adhesion layer10is not limited thereto.

The adhesion layer10has a temperature resistance such that the adhesion layer10may be used for temporal bonding/delamination of a flexible substrate. For example, the adhesion layer10may have a temperature resistance of about 450° C. or higher.

The adhesive of the adhesion layer10may be uniformly, or substantially uniformly applied onto the carrier in an initial step. After the application of the adhesive, a pre-treatment process may be performed, or a flexible substrate may be directly laminated without performing a pre-treatment process, according to exemplary embodiments.

The flexible substrate4is laminated on the electrically conductive adhesion layer10. The flexible substrate4may be formed of, for example, plastic, glass (e.g., thin glass), a metal foil, etc., however the flexible substrate4is not limited thereto.

Referring toFIG. 1, the current supply source30, which supplies a current to the electrically conductive adhesion layer10, and a conducting wire34, which transmits the current supplied from the current supply source30to the electrically conductive adhesion layer10, are connected to the electrically conductive adhesion layer10.

In an exemplary embodiment, the current supply source30may supply a high voltage current (e.g., a current capable of providing a relatively high voltage) to the electrically conductive adhesion layer10for a short time. As a result, the bond created by the electrically conductive adhesion layer10may be broken, allowing for the carrier2and the flexible substrate4to be disconnected/detached from each other. The value of the applied current and/or voltage, and/or the application time of the applied current and/or voltage may be controlled to break the bond formed by the adhesion layer10without causing damage to the flexible substrate4.

In an exemplary embodiment, a bulk metal20may be brought into contact with the flexible substrate4or the carrier2. Although the configuration shown inFIG. 1illustrates the bulk metal20being located on the flexible substrate4, the location of the bulk metal20is not limited thereto. The bulk metal20may be formed of, for example, copper, aluminum, nickel, titanium, or any combination thereof, however the bulk metal20is not limited thereto. The bulk metal20may protect the flexible substrate4, as described in further detail below.

According to an exemplary embodiment, when a high voltage current is applied to the electrically conductive adhesion layer10, the temperature of the adhesion layer10may be rapidly increased to a temperature level that is higher than a breaking point of the adhesive of the adhesion layer10. Once the temperature level increases beyond the breaking point, the bond created by the adhesion layer10is broken, permitting the flexible substrate4to be separated from the carrier2.

As described above, the bulk metal20may be included in the apparatus1to protect the flexible substrate4. For example, the bulk metal20may protect the flexible substrate4from damage that may potentially be caused by the high temperature that results from applying a high voltage current to the electrically conductive adhesion layer10. The bulk metal20may have a wide contact surface so as to be attached over an entire area, or over a substantially entire area, of the flexible substrate4or the carrier2.

When the bulk metal20is disposed on the flexible substrate4(or the carrier2), the flexible substrate4disposed beneath the bulk metal20, which as described above, may have high thermal conductivity, may be rapidly cooled by the bulk metal20. For example, the flexible substrate4may be cooled when the temperature is increased via an electric current provided to the adhesion layer10, or when the flexible substrate4is heated.

Thus, according to exemplary embodiments of the present invention, undesired influences on the flexible substrate4, which may vary in accordance with different temperature changes during a delamination process, may be reduced.

FIG. 2is a schematic diagram showing an apparatus for temporarily bonding and delaminating a substrate on a carrier, according to an exemplary embodiment of the present invention.FIGS. 3 and 4are plan views showing examples of the arrangement of a wire within an adhesion layer of the apparatus ofFIG. 2, according to exemplary embodiments of the present invention.

For convenience of explanation, a description of elements, processes, and configurations previously described may be omitted.

Referring toFIGS. 2 to 4, an apparatus1′ for temporarily bonding and delaminating the substrate4on the carrier2in accordance with an exemplary embodiment may include an adhesion layer12and a metal wire32disposed within (e.g., buried in) the adhesion layer12.

The adhesion layer12may be formed of a material having no electrical conductivity, or a low electrical conductivity. Inclusion of the metal wire32within the adhesion layer12permits the adhesion layer12to function similarly to the electrically conductive adhesion layer10described with reference toFIG. 1, as described below.

In an exemplary embodiment, the metal wire32may be buried in the adhesion layer12after the adhesion layer12is applied on the carrier2. In this case, the metal wire32may be connected to the current supply source30by the conducting wire34, permitting a high voltage current to be applied thereto.

According to exemplary embodiments, the metal wire32buried in the adhesion layer12may be disposed in a variety of patterns within the adhesion layer12. For example, the metal wire32may be disposed in a zigzag pattern as shown inFIG. 3, or in a lattice pattern as shown inFIG. 4. Disposing the metal wire32in a zigzag pattern or a lattice pattern in the adhesion layer12may aid in the uniform dispersal of heat in the adhesion layer12(e.g., heat generated when a high voltage current is applied to the adhesion layer12).

The metal wire32may be made of a material having high electrical conductivity such as, for example, aluminum, nickel, copper, or any combination thereof, however the metal wire32is not limited thereto.

According to exemplary embodiments, a diameter of the metal wire32may range from about 10 μm to about 50 μm, and more specifically, from about 15 μm to about 30 μm. However, the diameter of the metal wire32is not limited thereto.

When the metal wire32is buried in the adhesion layer12, a high voltage current may be applied to the metal wire32, causing the metal wire32to be rapidly heated, thereby break the bond created by the adhesion layer12, as described above.

According to exemplary embodiments, the flexible substrate4and the carrier2may be separated from each other by configuring the adhesion layer12such that the current applied to the metal wire32is moved throughout a large portion of the wire32formed in the zigzag or lattice pattern, and thus, throughout a large portion of the adhesion layer12. For example, the current applied to the metal wire32may be applied in a non-constant manner (e.g., the current may be rotated or shaken through the wire32).

FIG. 5is a flowchart showing a method of temporarily bonding and delaminating a substrate on a carrier, according to an exemplary embodiment of the present invention.

Referring toFIGS. 1 to 5, a method for temporarily bonding and delaminating a substrate on a carrier according to an exemplary embodiment includes forming an electrically conductive adhesion layer on a carrier (e.g., a rigid carrier) at operation S10.

The adhesion layer may be formed, for example, by applying an adhesive formed of an electrically conductive material to the carrier2(seeFIG. 1), or by burying the metal wire32within the adhesion layer12(seeFIG. 2). As described above, the electrically conductive adhesion layer10or12may be formed such that a high voltage current may be supplied thereto.

The flexible substrate4is laminated on the electrically conductive adhesion layer10or12at operation S20.

The bulk metal20may be laminated on the flexible substrate4or the carrier2at operation S30. In exemplary embodiments, the bulk metal20may not be included.

The electrically conductive adhesion layer10or12is heated by applying a high voltage current to the electrically conductive adhesion layer10or12at operation S40.

Upon heating the electrically conductive adhesion layer10or12, the bond created by the electrically conductive adhesion layer10may be broken, thereby permitting the delamination of the flexible substrate4from the surface of the carrier2without damaging the flexible substrate4at operation S50.

As described above, according to exemplary embodiments of the present invention, a flexible substrate may be coupled to a carrier using an electrically conductive adhesion layer that serves as a means for bonding and coupling the flexible substrate to the carrier in a non-permanent manner, and permits the flexible substrate to be delaminated from the carrier after a manufacturing process has been performed.