KR20170107007A - Method for bonding a highly flexible substrate to a carrier and a product formed therefrom - Google Patents

Abstract

Performing at least one of stress application and deformation application to the carrier substrate so as to induce the out-of-plane curvature in the first direction, positioning the flexible substrate on the carrier substrate while maintaining at least one of stress application and deformation application of the carrier substrate Wherein the bonding begins at the start region and thereafter the bonding front propagates the bond from the starting region until the flexible substrate is bonded to the carrier substrate, A method for bonding a flexible substrate to a carrier substrate by inducing bonding is disclosed. The characteristics of the joining front portion tend to cause the flexible substrate and the carrier substrate bonded in the second direction opposite to the first direction to bend out of the plane, so that the out-of-plane deformation amount is controlled after bonding.

Description

Method for bonding a highly flexible substrate to a carrier and a product formed therefrom

Cross reference of related application

This application claims the benefit of U.S. Patent Application No. 62/106417, filed January 22, 2015, the content of which is incorporated herein by reference in its entirety. Claim the benefit of priority under §119.

Technical field

This disclosure is directed to a method and apparatus for processing a flexible substrate, such as a highly flexible substrate, using so-called sheet manufacturing techniques designed for thicker and more rigid substrates.

Sheet manufacturing techniques typically require each substrate (e.g., a glass sheet) to be processed by conveying each sheet from a source to a destination through any number of processing steps (heating, scoring, trimming, Processing. The transport of each sheet may involve a number of elements that cooperate to move each substrate from station to station, preferably without deteriorating any desirable characteristics of the substrate. For example, a typical transport mechanism may include any number of non-contact type support members, contact type support members, rollers < RTI ID = 0.0 > , A lateral guide, and the like. The non-contact support member may include an air bearing, fluid bar (s), low friction surface (s), and the like. The non-contact support element may comprise a combination of positive and negative fluid pressure streams to "float" the substrate during transport. The contact-type support element may include a roller for stabilizing the substrate during transport through the system.

The aforesaid transport mechanisms for the sheet manufacturing system typically have sufficient stiffness, material integrity, and / or sufficient rigidity to have the appropriate mechanical dimensionality despite the forces that may be exerted on the substrate during processing through the transport and fabrication system Is designed for a relatively thick substrate, such as a thickness that represents other properties. Conventional sheet manufacturing techniques for cover glasses used, for example, in liquid crystal displays (or other similar applications), typically involve the use of a glass substrate, such as a glass substrate, Is required to exhibit a relatively high rigidity.

However, the use of these sheet manufacturing techniques may be problematic when a substrate having a significantly low stiffness (e.g., a glass substrate that is highly flexible) is processed.

At least some of the problems that may occur using sheet manufacturing techniques on highly flexible substrates may be overcome by designing specialized processing equipment to transport and process such substrates. However, such a design would require a significant non-recurring expense in terms of time and resources, as well as making existing (and possibly complete) production facilities easier to use. For example, in the processing of highly flexible substrates, conventional sheet manufacturing techniques may be discarded in favor of "roll-to-roll" transfer and processing equipment. In principle, this substitution may lead to lower manufacturing costs in the long run, but the cost of the acyclic circuit for designing and implementing a new roll-to-roll system for highly flexible substrate materials will be very significant, It will require innovation to process certain types of flexible substrates.

There is therefore a need in the art for a novel method and apparatus for modifying a flexible substrate so that it may be processed using sheet processing techniques.

While the disclosure herein may refer to methodologies and apparatus involving a substrate formed from glass, the skilled artisan will appreciate that the methodology and apparatus of the present disclosure can be used to form a glass substrate, a crystalline substrate, a monocrystalline substrate, a glass ceramic It will be understood that the present invention is applied to many kinds of substrates including substrates, polymer substrates, and the like.

For example, one type of flexible substrate material is referred to as Corning®Willow®Glass, a glass material suitable for a number of purposes. A relatively thin material (approximately 0.1 mm thick, approximately the thickness of a sheet of paper) combines the strength and flexibility of the glass material and provides applications ranging from general to very sophisticated, such as wrapping a display element of a device or a structure Support. Corning®Willow®Glass is a very thin backplane for both organic light emitting diodes (OLEDs) and liquid crystal displays (LCDs), such as may be used in high performance portable devices (eg smart phones, tablets, backplanes, color filters, and the like. Corning®Willow®Glass may also be used to fabricate electronic components such as touch sensors, seals for OLED displays, and other moisture and oxygen sensitive technologies. The Corning®Willow®Glass may be about 100 microns (micrometers or microns) to 200 microns thick and is highly flexible and has a density of about 2.3 to 2.5 g / cc, a Young's modulus of about 70 to 80 GPa, A Poisson's ratio of 0.25, and a minimum bending radius of about 185 to 370 mm.

If each substrate of Corning®Willow® Glass has been processed using typical sheet manufacturing techniques, the thinness and flexibility of the material can cause deterioration of the material properties of the glass, critical breakage of the glass, and / or interference or damage to the sheet processing equipment There is a possibility of causing it.

The present disclosure addresses the problem of processing flexible substrates such as thin flexible glass substrates in existing sheet manufacturing systems (designed for thicker, more rigid substrates). In particular, the methods and apparatus herein provide temporary bonding of a flexible substrate to a thicker and / or stiffer carrier substrate, which is characterized by having more rigid mechanical properties during processing in the sheet processing system The substrate is presented. After processing, the temporary bonding is released and the flexible substrate is subjected to further fabrication, processing, or delivery to the customer.

Other aspects, features, and advantages will become apparent to those skilled in the art from the description of this specification taken in conjunction with the accompanying drawings.

While, for purposes of illustration, presently preferred forms are shown in the drawings, it is to be understood that the embodiments disclosed and described herein are not limited to the exact arrangement and means shown.
1 is a schematic perspective view of a process in which a flexible substrate is bonded to a carrier substrate in preparation for processing a flexible substrate in a conventional sheet production system.
2 is a schematic side view of a flexible substrate bonded to a carrier substrate for processing a flexible substrate in a conventional sheet production system.
Figure 3 is a schematic perspective view of a first sequence that may cause the flexible substrate to be bonded to a carrier substrate, resulting in a dome-shaped out-of-plane deformation of the bonded structure.
4 is a schematic diagram of a quantitative measurement of the out-of-plane deformation of the bonded structure of FIG. 3;
Figure 5 is a schematic perspective view of a second sequence in which a flexible substrate may be bonded to a carrier substrate, causing a cylindrical out-of-plane deformation of the bonded structure.
Figure 6 is a schematic diagram of quantitative measurement of the out-of-plane deformation of the bonded structure of Figure 5;
Figures 7A, 7B and 7C are schematic diagrams of a tool that may be employed to initiate a joining front and a starting region that characterize the bonding process of Figure 5;
Figure 8 is a molding machine configured to induce an out-of-plane curvature in the carrier substrate prior to bonding to offset the tendency for out-of-plane deformation in the bonded structure that would otherwise occur.
Figure 9 is a schematic diagram of quantitative measurements of the out-of-plane deformation of the bonded structure resulting from the induced out-of-plane curvature in the carrier substrate of Figure 8;
10A and 10B are schematic views of a thermal process for bonding a flexible substrate to a carrier substrate to counteract the tendency for out-of-plane deformation to occur otherwise within the bonded structure.

For purposes of explanation, the embodiments described below refer to the processing of a flexible substrate formed from glass, which is a preferred material. However, it is noted that embodiments may employ different materials to implement flexible substrates such as crystalline substrates, single crystal substrates, glass ceramic substrates, polymer substrates, and the like.

Reference is now made to Fig. 1, which is a schematic perspective view of a process in which a flexible substrate 102 is temporarily bonded to a carrier substrate 104 in preparation for processing the flexible substrate 102 in a conventional sheet manufacturing system. The rationale for bonding the flexible substrate 102 to the thicker and / or stiffer carrier substrate 104, as described above, is based on a theoretical approach to sheet processing designed to handle substrates that are more rigid than the flexible substrate 102 Is to present the flexible substrate 102 as if it had more rigid mechanical properties during processing in the system.

Referring to Fig. 2, a schematic diagram of the final bonded structure 100 (the flexible substrate 102 is on the carrier substrate 104) is shown. In this regard, the carrier substrate 104 may be formed from a sheet of material such as a glass material, wherein the carrier substrate 104 has a length dimension in the X-axis, a width dimension in the Y-axis, (Within the Cartesian coordinate system). In particular, the X-axis and Y-axis define an X-Y plane, which may be referred to herein as being within a plane and / or defining an in-plane reference. Similarly, the flexible substrate 102 is also formed from a sheet of material, which may be a glass material, wherein the flexible substrate 102 has a length dimension in the X-axis, a width dimension in the Y-axis, The axis has a thickness dimension. As described above, the flexible substrate 102 is flexible, substantially flexible (i) less flexible than the carrier substrate 104, and (ii) substantially smaller than the thickness of the carrier substrate 104 Represents at least one.

In one or more embodiments, the flexible substrate 102 is formed from glass and has a thickness of between about 50 um (micron or micrometer) to about 300 um, and (ii) between about 100 um and about 200 um . According to one or more other embodiments, the flexible substrate 102 has a density of about 2.3 to 2.5 g / cc, a Young's modulus of about 70 to 80 GPa, a Poisson's ratio of about 0.20 to 0.25, and a Young's modulus of about 185 to 370 mm And may have at least one of the minimum bending radius.

Similarly, in one or more embodiments, the carrier substrate 104 may be formed from glass, but the carrier substrate 104 preferably has a thickness of at least about 400 microns to about 1000 microns, And has a thicker thickness than the above.

Although further details regarding the bonding between the flexible substrate 102 and the carrier substrate 104 will be presented later herein, the bonding is transient, and the flexible substrate 102 is processed in a conventional sheet manufacturing system It is preferable to be mainly employed for After such processing, temporary bonding may not be performed, and the flexible substrate 102 may be separated from the carrier substrate 104 for further processing and / or use outside of a conventional sheet manufacturing system.

Any number of mechanisms for achieving a bond (such as temporary) between the flexible substrate 102 and the carrier substrate 104 and / or the like may be used as long as the bonding parameters and characteristics described hereinafter are also considered and compensated. Process may be employed. As an example, one of ordinary skill in the art would be able to achieve the conditions disclosed herein using the following patent applications: U.S. Provisional Patent Application No. 61 / 736,887, filed December 13, 2012, U.S. Patent Application No. 10 / Filed on January 27, 2014, U.S. Provisional Patent Application No. 61/931924, filed January 27, 2014, U.S. Provisional Patent Application No. 61 / 931,912, filed January 27, 2014, filed January 27, And US Patent Application No. 61 / 977,364, filed April 9, < RTI ID = 0.0 > 2014, < / RTI > The entire disclosure of which is incorporated herein by reference.

In order to fully appreciate the advantages of the methods and apparatus disclosed herein, a detailed description of some bonding properties and phenomena will now be presented with reference to FIGS. 3 is a schematic perspective view of a sequence that may cause the flexible substrate 102 to be bonded to the carrier substrate 104, resulting in a substantially dome-shaped out-of-plane deformation of the bonded structure 100. 4 is a schematic diagram of a quantitative measurement of the out-of-plane deformation of the bonded structure 100 of FIG.

Again, for purposes of explanation, before the bonding process, and at least in part during the bonding process, the flexible substrate 102 and the carrier substrate 104 have respective length dimensions in the X-axis, respective width dimensions in the Y-axis, and Z - is characterized by the thickness dimension of each axis. The X-axis and the Y-axis thereby define an X-Y plane with an in-plane reference (e.g., the flatness of the structure 100 bonded thereto in FIG. 4 is compared).

With particular reference to FIG. 3, the bonding process may include positioning the flexible substrate 102 over the carrier substrate 104 and then inducing bonding. More specifically, when the flexible substrate 102 is positioned over the carrier substrate 104, there will typically be some ambient gas (such as air) that maintains some relatively small separation between the substrates. To initiate bonding, the starting area may be set by localized compression of the flexible substrate 102 and the carrier substrate 104 together, for example, via mechanical pressing forces. In the depicted example, the single point and / or generally circular area is directed toward the carrier substrate 104 as shown by the arrow 22 and through the concentrated pressure of the flexible substrate 102 in contact with the carrier substrate And may be set as the start area 20.

It will be appreciated by those of ordinary skill in the art that one or more other junction criteria may also work together with inducing a starting region (see the aforementioned U.S. patent application). In this way, the bonding induced in the starting region 20 will propagate along the bonding front portion 24. In the case of the illustrated starting region 20 (i.e. a single point and / or a generally circular region), the joining front portion 24 extends in a radial direction extending from the starting region 20 in all directions in the XY plane Will contain a directed vector. The joining front portion 24 will continue to expand radially outwardly in the X-Y plane until it reaches the edge of the substrate, where the flexible substrate 102 is bonded to the carrier substrate 104.

Through experimentation, it has been found that the (radially extending) bonding front portion 24 described above will cause the bonded structure 100 to deform out-of-plane (i.e., outside the reference plane defined by the Y-Y plane). In particular, the radially extending joining front 24 results in a generally domed out-of-plane curvature in the Z-axis, which is shown as being in a downward direction along the Z-axis in the example. In other words, without some compensation mechanism, the unique bonding of the flexible substrate 102 to the carrier substrate 104 will produce an undesirable out-of-plane curvature, which, if left unmodified, Lt; RTI ID = 0.0 > and / or < / RTI > In practice, it is generally understood that a conventional sheet manufacturing system works best when the introduced substrate (in this case, the bonded structure 100) to be processed is relatively flat.

However, the bonded structure 100 of FIG. 3 is generally not flat. In fact, with reference to FIG. 4, a schematic diagram of quantitative measurement of the out-of-plane deformation of the example of the bonded structure 100 of FIG. 3 is shown. With respect to laboratory experiments, the Z-axis of the graph of FIG. 4 is measured in um, and the X-axis and Y-axis are measured in mm. In general, the domed curvature is about 225 to 300 μm at most. Such curvature may not be acceptable in a conventional sheet manufacturing system and / or may produce a defective intermediate product that is not suitable for commercial use. As will be described in greater detail hereinbelow, compensation of this undesirable junction phenomenon may be accomplished according to embodiments of the present disclosure.

Another example of the out-of-plane curvature resulting from bonding the flexible substrate 102 to the carrier substrate 104 will now be described with reference to Figs. 5 and 6. Fig. 5 is a schematic perspective view of an example of an alternative sequence in which a flexible substrate 102 may be bonded to a carrier substrate 104, resulting in a substantially cylindrical out-of-plane deformation of the bonded structure 100. Fig. 6 is a schematic diagram of quantitative measurement of the out-of-plane deformation of the bonded structure 100 of Fig. 5 obtained through experiments.

With particular reference to Figure 5, the bonding process may again include positioning the flexible substrate 102 over the carrier substrate 104 and then inducing bonding. To initiate the bonding, the starting area is set again by localized compression of the flexible substrate 102 and the carrier substrate 104, for example, via a mechanical pressing force. In the illustrated example, however, the linear extension initiation region 30 is generally oriented toward the carrier substrate 104 and in contact with the carrier substrate, as compared to the previous example of FIG. 3, And is set via concentrated pressure. The mechanism for creating the linear extension pressure and the final linearly oriented extension starting region 30 will be described in greater detail herein below.

In the case of the illustrated linearly oriented extended starting region 30, the bonded front portion 34 will comprise a linearly oriented vector extending in the X-Y plane, transverse to the extending direction of the starting region 30. For example, the start region 30 may extend substantially linearly along a line parallel to the Y-axis (such as along the adjacent edge of each substrate 102, 104 shown on the right side of FIG. 5) have. As a result, the splice front 34 includes a vector that is substantially linearly spaced along a line parallel to the Y-axis (such as line 30) and extends in a direction transverse to the Y-axis , In a direction parallel to the X-axis and perpendicular to the Y-axis). The joining front portion 34 will continue to expand linearly away from the starting region 30 in the XY plane until it reaches the end of the substrate where the flexible substrate 102 is bonded to the carrier substrate 104 do.

5, a variation of the process just described and described immediately above is shown at an intermediate position along the X-axis, for example at a predetermined position between adjacent edges of each substrate 102, 30, < / RTI > In this case, the joining front portion 34 will again comprise a vector that is substantially linearly spaced along a line parallel to the Y-axis (such as line 30), and in the direction transverse thereto again, (30). Particularly, however, the joining front portion 34 has two components: a portion of a vector that extends linearly (and transversely) away from the start region 30 in one direction (e.g., left direction in FIG. 5) Component (s), and other components of the vector that extend linearly (and transversely) away from the starting region 30 in the other opposite direction (e.g., the right direction of Figure 5). Both components of the joining front portion 34 will continue to expand linearly away from the starting region 30 in the XY plane until they reach the edge of the substrate whereupon the flexible substrate 102 contacts the carrier substrate 104 .

Through experimentation, it has been found that the above-mentioned (linear extension) joining front portion 34 will cause the joined structure 100 to deform out-of-plane (i.e., outside the reference plane defined by the X-Y plane). In particular, the linear extension bonding front 34 causes a generally cylindrical out-of-plane curvature in the Z-axis, which is shown as being in a downward direction along the Z-axis in the example. Again, without any compensation mechanism, the unique bonding of the flexible substrate 102 to the carrier substrate 104 will produce an undesirable out-of-plane curvature, which, if left unmodified, And may produce additional undesirable effects on the process. Again, the bonded structure 100 of FIG. 5 is generally not flat. Indeed, referring to FIG. 6, laboratory experiments indicate that the out-of-plane generally cylindrical curvature is up to a maximum of 200 to 250 μm.

As described above, one of ordinary skill in the art will understand that there are a number of mechanisms that may be employed to create the linear extension pressure and the final linearly oriented extension starting region 30. [ For example, referring to FIG. 7A, a leaf spring device 32-1 may be employed, which includes a relatively rigid frame member 40 and a relatively flexible spring element 42. FIG. The flexible spring element 42 is rotationally coupled to the frame member via respective hinged couplings 44-1 and 44-2 to create a leaf spring biasing element. In operation, the frame member 40 and the spring element 42 are oriented parallel to the desired linear start region 30, as on the flexible substrate 102. A downward directed force is then applied to the frame member 40 to cause the flexible spring element 42 to compress the flexible substrate 102 against the carrier substrate 104 along the line thereby to move the desired starting region 30 .

7B, a rocker-type device 32-2 may be employed, which may be a relatively small, relatively large blade having a curved blade portion 52, which may also be referred to as a rocker press. And a rigid structure (50). In operation, the structure 50 and the blade portion 52 are oriented parallel to the desired linear start region 30, as on the flexible substrate 102. A downward directed locking force is then applied to the structure 50 so that the curved blade portion 52 urges the flexible substrate 102 against the carrier substrate 104 along the line thereby to move the desired starting region 30 .

7C, a multi-point linear press apparatus 32-3 may be employed, which includes a relatively rigid frame member 60 and a plurality of pressing elements 62 resiliently coupled thereto . The biasing element may be self-resilient and / or may include some biasing mechanism to allow the individual, or group of biasing elements 62 to be provided when biased. In operation, a linear array of frame members 60 and pressing elements 62 is oriented parallel to the desired linear start region 30, as on flexible substrate 102. [ A downward directed force is then applied to the frame member 60 so that the pressing element 62 urges the flexible substrate 102 against the carrier substrate 104 along the line thereby creating the desired starting area 30 .

It will be appreciated by those of ordinary skill in the art that there are a number of contactless mechanisms that may be employed to create a linear extension pressure and a final linearly oriented extension starting region 30. [ In another alternative embodiment not shown, the non-contact means may comprise (i) one or more air jets; (ii) one or more air bearings; And (iii) one or more ultrasonic bearings.

As described above, compensation of domed and / or cylindrical out-of-plane deformations due to undesirable bonding phenomena may be accomplished according to embodiments herein. Generally, this compensation may be accomplished by manipulating the carrier substrate 104 prior to the bonding operation. For example, the process may apply stress to the carrier substrate 104 to induce a curvature out of the XY plane in a direction along the Z-axis offsetting the induced curvature out of the XY plane that would occur via a junction front propagation phenomenon stressing < / RTI > and straining. Thus, for example, when the junction front propagation phenomenon induces a curvature out of the XY plane in a direction that is characterized (e.g., in a downward direction or in a negative Z-axis direction) as shown in Figures 3 and 5 , The general compensation methodology may include at least one of stress application and deformation application to the carrier substrate 104 to induce curvature out of the XY plane in the opposite direction (e.g., upward or positive Z-axis direction) It is accompanied.

After this derived curvature is achieved in the carrier substrate 104, the bonding process is performed by positioning the flexible substrate 102 over the carrier substrate 104 while maintaining at least one of stress application and deformation application of the carrier substrate 104 May be included. Next, the start region is set, and the joining front side propagation continues until the flexible substrate 102 and the carrier substrate are bonded together. The degree of curvature induced in the carrier substrate 104 prior to and at least partially during the bonding process is controlled so that the characteristic of curvature outside the X-Y plane due to the bonding front is substantially canceled (or at least relaxed).

Referring now to FIG. 8, which is a schematic illustration of a forming machine configured to offset the tendency for out-of-plane deformation to occur otherwise within the bonded structure 100, taking the cylindrical out-of-plane deformation case first. The forming machine includes a base 70 and a deviation surface 72 spaced from the base 70. The offset surface 72 may be curved with respect to the base 70 via one or more actuators. The first actuator 74 may be located in the generally central region (center along the X-axis) of the molding machine. The first actuator 74 includes a deflection member 76 such as a rod or the like that is operative to extend generally parallel to the Y-axis and to urge the deflection surface 72 upwardly in the positive Z-axis direction It is possible. The adjustment mechanism 78 operates to control the offset position of the deviation member 76 from the base 70 and to control the amount of deviation action by the deviation member 76 with respect to the deviation surface 72. [ An optional second actuator 82 moves the lateral edges of the deflection surface 72 parallel to the base 70 and proximate to or away from the deflection member 76, And to provide some adjustable amount of bias action by the deflection member 76. One or both of the actuators 74, 82 may be computer controlled. This operation produces an amount of adjustable cylindrical out-of-plane curvature of the deflection surface 72 in a direction opposite to that of the curvature shown in Fig.

In operation, the carrier substrate 104 may be disposed on the deflection surface 72 of the forming machine such that operation of the carrier substrate 104 may be accomplished prior to the bonding operation. In particular, the deflecting surface 72 is configured to guide the cylindrical out-of-plane curvature (out of the XY plane) in the direction along the Z-axis offsetting the induced curvature out of the XY plane that would occur through the junction front- Induces mechanical stress and / or deformation to the substrate 104. For example, one of the stress application and / or deformation application through the deflection surface 72 may be applied to the carrier substrate (not shown) for an axis that is spaced from the XY plane in the Z-axis direction and parallel to the Y- 104 may be characterized as being mechanically bending. 8, such an axis 90 is positioned parallel below the deflection member 76 thereby forming a deflection surface 72 and a radius of curvature 92 of the carrier substrate 104 so that the curvature outside the XY plane (For example, the upward direction as shown) in the Z-axis.

After this derived curvature is achieved in the carrier substrate 104, the bonding process is performed by positioning the flexible substrate 102 over the carrier substrate 104 while maintaining at least one of stress application and deformation application of the carrier substrate 104 May be included. Next, the start area 30 is set using one of the above-described mechanisms or some alternative mechanisms. By way of example, the starting region 30 may be substantially perpendicular to the Y-axis along a line parallel to the Y-axis so that the joining front portion 34 extends substantially linearly along a line parallel to the Y-axis (i.e., Or may be linearly extended. Thus, the joining front portion 34 propagates away from the starting region 30 in the direction transverse to the Y-axis (e. G., The junction front propagation is parallel to the X-axis). Thereafter, the propagation of the linear bonding front portion 34 continues until the flexible substrate 102 and the carrier substrate 104 are bonded together. The induced curvature in the carrier substrate 104 prior to and during the bonding process by the offset surface 72 is controlled to relax the characteristic of the curvature outside the X-Y plane due to the bonding front portion 34.

9 is a schematic diagram of a quantitative measurement of the out-of-plane deformation of the bonded structure 100 resulting from the use of the above-described compensation methodology and / or apparatus. In particular, lab experiments show that the out-of-plane curvature of the compensated bonded structure 100 is (i) about 200 [mu] m; (ii) about 100 [mu] m; (iii) about 75 [mu] m; And (iii) less than about 50 [mu] m. By comparison, the out-of-plane curvature of the uncompensated bonded structure 100, which is schematically shown in FIG. 6, exhibits a curvature of the order of 200 to 250 um at most, and some experimental results show that the uncompensated bonded structure 100 Of the out-of-plane curvature may be on the order of 300 to 400 um.

It is common for a person skilled in the art to understand that the dome out-of-plane deformation case is a stress application and deformation of the carrier substrate 104 in a dome shape that counteracts the dome- (E. G., A mechanical mechanism) for at least one of the < / RTI > In other words, before the flexible substrate 102 is bonded to the carrier substrate 104, the mechanical mechanism presses the carrier substrate 104 with a domed curvature outside the XY plane in the Z-axis direction opposite to that shown in Fig. . Thereafter, the bonding region 20 (single point or localized diameter) may be induced and the radially extending bonding front 24 may be roughened until the flexible substrate 102 is bonded to the carrier substrate 104 It may spread. It is contemplated that the induced domed curvature in the carrier substrate 104 before the bonding process and at least partially during the bonding process by the mechanical mechanism is controlled to relax the characteristic of the curvature outside the XY plane due to the bonding front 24 .

In an alternative embodiment, at least one of stress application and deformation application of the carrier substrate 104 in a dome shape prior to bonding may be thermally accomplished. 10A and 10B, which are schematic diagrams of a thermal process for bonding a flexible substrate 102 to a carrier substrate 104 to counteract the tendency for out-of-plane deformation in the bonded structure 100, 10B. The thermal process includes heating at least one of the flexible substrate 102 and the carrier substrate 104 to different temperatures (T1, T2) before initiating bonding (Fig. 10A). Next, the flexible substrate 102 is positioned over the carrier substrate 104 (Fig. 10B) and the radially extending bonding front 24 is guided in accordance with the procedure described above. In particular, the different temperatures T1, T2 are substantially maintained during at least partial induction of the bonding and propagation of the radially extending bonding front 24. Thereafter, the flexible substrate 102 and the carrier substrate 104 are allowed to reach thermal equilibrium after the bonding is accomplished. Again, the induced stresses and / or deformation in the carrier substrate due to the thermal process before, during, and at least partially during the bonding process are controlled such that the characteristics of the curvature outside the XY plane due to the bonding front 24 are relaxed .

While the disclosure herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and practices of the embodiments of the present disclosure. It is, therefore, to be understood that numerous modifications may be made to the exemplary embodiments, and that other arrangements may be devised without departing from the spirit and scope of the present application. The various described features may be combined in any and all combinations, for example, in accordance with the following aspects of the present disclosure.

According to a first aspect,

Providing a carrier substrate formed from a sheet of material, wherein the carrier substrate has a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z-axis, wherein the X- Providing a carrier substrate defining a plane,

Providing a flexible substrate formed from a sheet of material, wherein the flexible substrate has a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z-axis Step,

Performing at least one of stress application and deformation application to the carrier substrate to induce a curvature out of the X-Y plane in the first direction along the Z-axis,

Positioning the flexible substrate on the carrier substrate while maintaining at least one of stress application and deformation application of the carrier substrate,

Inducing a bond between the flexible substrate and the carrier substrate such that the bonding starts in the starting region and thereafter the bonding front propagates the bonding from the starting region until the flexible substrate is bonded to the carrier substrate, , ≪ / RTI >

The characteristics of the joining front are provided in such a way that the flexible substrate bonded in the second direction along the Z-axis opposite to the first direction and the carrier substrate tend to bend out of the X-Y plane.

According to a second aspect, there is provided a method according to embodiment 1, wherein at least one of stress application and deformation application comprises mechanically bending the carrier substrate into a cylindrical shape.

According to a third aspect, in the second aspect,

At least one of stress application and deformation application comprises mechanically bending the carrier substrate relative to an axis that is spaced from the X-Y plane and parallel to the Y-axis in the Z-axis direction to induce curvature,

The curvature is characterized by the radius of curvature from the axis to the carrier substrate such that the curvature outside the X-Y plane is in the first direction along the Z-axis.

According to a fourth aspect, in the third aspect,

The starting region extends substantially linearly along a line parallel to the Y-axis,

The junction front extends substantially linearly along a line parallel to the Y-axis,

The joining front is provided with a method of propagating away from the direction transverse to the Y-axis to the starting region.

According to a fifth aspect, in the fourth aspect, a method is provided in which the direction of the joining front-side propagation is parallel to the X-axis.

According to a sixth aspect, in accordance with a sixth aspect, there is provided a method as described in the third aspect, wherein the starting region is guided along the linear extending zone toward the carrier substrate and in contact with the carrier substrate to press the flexible substrate.

According to a seventh aspect, in aspect 6, the linear extension zone comprises (i) a leaf spring biasing element; (ii) Rocker presses; (iii) multi-point linear presses; (iv) one or more air jets; (v) one or more air bearings; And (vi) pressing against the flexible substrate via at least one of the one or more ultrasonic bearings.

According to an eighth aspect, in the first aspect, a method is provided in which at least one of stress application and deformation application includes mechanically bending the carrier substrate into a dome shape.

According to a ninth aspect, in the eighth aspect,

Wherein at least one of stress application and deformation application comprises heating the at least one of the flexible substrate and the carrier substrate to a different temperature before and during the propagation of the bonding front and propagation of the bonding front,

After the bonding is accomplished, a method is provided for allowing the flexible substrate and the carrier substrate to reach a thermal equilibrium.

According to a tenth aspect, in aspect 9,

The starting region is a substantially circular region or center point,

The joining front portion extends from the starting region substantially radially outwardly.

According to an eleventh aspect, there is provided a method as described in aspect 10, wherein the starting area is substantially induced from the center point toward the carrier substrate and in contact with the carrier substrate to press the flexible substrate.

According to a twelfth aspect, in any one of modes 1 to 11, a method is provided in which a flexible substrate is formed from glass.

According to a thirteenth aspect, there is provided a method according to any one of embodiments 1-12, wherein the flexible substrate has a thickness of either (i) from about 50 um to about 300 um, and (ii) from about 100 um to about 200 um / RTI >

According to a fourteenth aspect, in any one of embodiments 1-13, the flexible substrate has a density of about 2.3 to 2.5 g / cc, a Young's modulus of about 70 to 80 GPa, a Poisson's ratio of about 0.20 to 0.25, A minimum bending radius of 185 to 370 mm is provided.

According to a fifteenth aspect, in any one of modes 1 to 14, a method is provided in which a carrier substrate is formed from glass.

According to a sixteenth aspect, there is provided a method according to any one of modes 1 to 15, wherein the carrier substrate has a thickness of at least one of from about 400 [mu] m to about 1000 [mu] m.

[0040] According to a seventeenth aspect, in any one of modes 1 to 16, the amount of deformation outside the X-Y plane after bonding is (i) about 200 [mu] m; (ii) about 100 [mu] m; (iii) about 75 [mu] m; And (iv) less than about 50 [mu] m.

According to an eighteenth aspect, in any one of modes 1 to 17, (i) the flexibility of the flexible substrate is substantially more flexible than the flexibility of the carrier substrate, (ii) Wherein the thickness is at least one of substantially less than the thickness.

According to a nineteenth aspect, there is provided a flexible substrate bonded to a carrier substrate formed according to a process,

Providing a carrier substrate formed from a sheet of material, wherein the carrier substrate has a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z-axis, wherein the X- Providing a carrier substrate defining a plane,

Providing a flexible substrate formed from a sheet of material, wherein the flexible substrate has a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z- Wherein the flexibility of the carrier substrate is substantially more flexible than the flexibility of the carrier substrate, and (ii) the thickness of the flexible substrate is substantially less than the thickness of the carrier substrate;

Performing at least one of stress application and deformation application to the carrier substrate to induce a curvature out of the X-Y plane in the first direction along the Z-axis,

Positioning the flexible substrate on the carrier substrate while maintaining at least one of stress application and deformation application of the carrier substrate,

Inducing a bond between the flexible substrate and the carrier substrate such that the bonding starts in the starting region and thereafter the bonding front propagates the bonding from the starting region until the flexible substrate is bonded to the carrier substrate, , ≪ / RTI >

The characteristics of the junction front tend to cause the flexible substrate and carrier substrate bonded in the second direction along the Z-axis opposite to the first direction to bend out of the X-Y plane,

The amount of deformation outside the X-Y plane after bonding is (i) about 200 [mu] m; (ii) about 100 [mu] m; (iii) about 75 [mu] m; And (iv) less than about 50 [mu] m.

According to a twentieth aspect,

A carrier substrate formed from a sheet of material, wherein the carrier substrate has a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z-axis, wherein the X- A carrier substrate,

The flexible substrate having a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z-axis, the flexible substrate being formed from a sheet of material and bonded to the carrier substrate, Wherein the flexibility of the flexible substrate is substantially more flexible than the flexibility of the carrier substrate, and (ii) the thickness of the flexible substrate is substantially at least one of a thickness of the carrier substrate,

The amount of deformation outside the X-Y plane after bonding is (i) about 200 [mu] m; (ii) about 100 [mu] m; (iii) about 75 [mu] m; And (iv) less than about 50 [mu] m.

According to a twenty-first aspect, in accordance with the twenty-first aspect, the flexible substrate is provided with an apparatus having a thickness of (i) about 50 μm to about 300 μm, and (ii) about 100 μm to about 200 μm.

According to a twenty-second aspect, in embodiment 20 or embodiment 21, the flexible substrate has a density of about 2.3 to 2.5 g / cc, a Young's modulus of about 70 to 80 GPa, a Poisson's ratio of about 0.20 to 0.25, An apparatus is provided having at least one of a minimum bending radius of 370 mm.

According to a twenty-third aspect, there is provided an apparatus according to any one of aspects 20 to 22, wherein the carrier substrate is formed from glass.

According to a twenty-fourth aspect, in any of embodiments 20-23, the carrier substrate is provided with an apparatus having a thickness of at least about 400 to about 1000 [mu] m.

Claims (24)

Providing a carrier substrate formed from a sheet of material, the carrier substrate having a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z- Providing a carrier substrate, the axis defining an XY plane,
Providing a flexible substrate formed from a sheet of material, said flexible substrate providing a flexible substrate having a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z-axis , ≪ / RTI &
Performing at least one of stress application and deformation application to the carrier substrate so as to induce a curvature out of the XY plane in the first direction along the Z-axis,
Positioning the flexible substrate on the carrier substrate while maintaining at least one of stress application and deformation application of the carrier substrate;
Inducing a bond between the flexible substrate and the carrier substrate such that the bonding starts at the start region and thereafter the bonding front is bonded to the carrier substrate from the starting region until the flexible substrate is bonded to the carrier substrate Propagating, < / RTI >
Wherein the characteristics of the bonding front tend to cause the flexible substrate and the carrier substrate bonded in a second direction along the Z-axis opposite to the first direction to bend out of the XY plane. 2. The method of claim 1, wherein at least one of the application of stress and the application of strain comprises mechanically bending the carrier substrate into a cylindrical shape. 3. The method of claim 2,
Wherein at least one of the application of stress and the application of deformation comprises mechanically bending the carrier substrate with respect to an axis spaced from the XY plane in the Z-axis direction and parallel to the Y-axis to induce curvature,
Wherein the curvature is characterized by a radius of curvature from the axis to the carrier substrate such that the curvature outside the XY plane is in a first direction along the Z-axis. The method of claim 3,
The starting region extends substantially linearly along a line parallel to the Y-axis,
The joining front portion extends substantially linearly along a line parallel to the Y-axis,
Wherein the joining front is propagating away from the starting region in a direction transverse to the Y-axis. 5. The method of claim 4,
Wherein the direction of the junction front propagation is parallel to the X-axis. The method of claim 3,
Wherein the starting region is guided along the linear extension zone toward the carrier substrate and in contact with the carrier substrate by pressing the flexible substrate. The method according to claim 6,
The linear extension zone comprises (i) a leaf spring biasing element; (ii) Rocker presses; (iii) multi-point linear presses; (iv) one or more air jets; (v) one or more air bearings; And (vi) pressing against the flexible substrate via at least one of the one or more ultrasonic bearings. The method according to claim 1,
Wherein at least one of the application of stress and the application of strain comprises mechanically bending the carrier substrate into a dome shape. 9. The method of claim 8,
Wherein at least one of the application of the stress and the application of the deformation includes heating the at least one of the flexible substrate and the carrier substrate to a different temperature before and during the propagation of the bonding front portion,
Wherein the flexible substrate and the carrier substrate are allowed to reach a thermal equilibrium after the bonding is accomplished. 10. The method of claim 9,
Wherein the starting region is a substantially circular region or a center point and the joining front portion extends substantially radially outwardly from the starting region. 11. The method of claim 10,
Wherein the starting region is substantially directed toward the carrier substrate at a central point and by contacting the carrier substrate to press the flexible substrate. 12. The method according to any one of claims 1 to 11,
Wherein the flexible substrate is formed from glass. 13. The method according to any one of claims 1 to 12,
Wherein the flexible substrate has a thickness of (i) from about 50 um to about 300 um, and (ii) from about 100 um to about 200 um. 14. The method according to any one of claims 1 to 13,
Wherein the flexible substrate has at least one of a density of about 2.3 to 2.5 g / cc, a Young's modulus of about 70 to 80 GPa, a Poisson's ratio of about 0.20 to 0.25, and a minimum bending radius of about 185 to 370 mm . 15. The method according to any one of claims 1 to 14,
Wherein the carrier substrate is formed from glass. 16. The method according to any one of claims 1 to 15,
Wherein the carrier substrate has a thickness of at least about 400 microns to about 1000 microns. 17. The method according to any one of claims 1 to 16,
The amount of deformation outside the XY plane after bonding is (i) about 200 [mu] m; (ii) about 100 [mu] m; (iii) about 75 [mu] m; And (iv) less than about 50 [mu] m. 18. The method according to any one of claims 1 to 17,
(i) the flexibility of the flexible substrate is substantially more flexible than the flexibility of the carrier substrate, and (ii) the thickness of the flexible substrate is substantially at least one of a thickness of the carrier substrate . A flexible substrate bonded to a carrier substrate formed according to a process,
Providing a carrier substrate formed from a sheet of material, the carrier substrate having a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z- Providing a carrier substrate, the axis defining an XY plane,
Providing a flexible substrate formed from a sheet of material, said flexible substrate having a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z-axis, wherein (i) Wherein the flexibility of the rigid substrate is substantially more flexible than the flexibility of the carrier substrate, and (ii) the thickness of the flexible substrate is substantially less than the thickness of the carrier substrate. Step,
Performing at least one of stress application and deformation application to the carrier substrate so as to induce a curvature out of the XY plane in the first direction along the Z-axis,
Positioning the flexible substrate on the carrier substrate while maintaining at least one of stress application and deformation application of the carrier substrate;
Inducing a bond between the flexible substrate and the carrier substrate such that the bonding starts at the start region and thereafter the bonding front is bonded to the carrier substrate from the starting region until the flexible substrate is bonded to the carrier substrate Propagating, < / RTI >
The characteristic of the joining front portion tends to cause the flexible substrate and the carrier substrate joined in a second direction along the Z-axis opposite to the first direction to bend out of the XY plane,
The amount of deformation outside the XY plane after bonding is (i) about 200 [mu] m; (ii) about 100 [mu] m; (iii) about 75 [mu] m; And (iv) less than about 50 [mu] m. Device,
A carrier substrate formed from a sheet of material, said carrier substrate having a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z-axis, wherein the X- A carrier substrate,
A flexible substrate formed from a sheet of material and bonded to the carrier substrate, the flexible substrate having a length dimension in the X-axis, a width dimension in the Y-axis, and a thickness dimension in the Z- (i) the flexibility of the flexible substrate is substantially more flexible than the flexibility of the carrier substrate, and (ii) the thickness of the flexible substrate is at least one of substantially less than the thickness of the carrier substrate. Comprising a substrate,
The amount of deformation outside the XY plane after bonding is (i) about 200 [mu] m; (ii) about 100 [mu] m; (iii) about 75 [mu] m; And (iv) less than about 50 [mu] m. 21. The method of claim 20,
The flexible substrate having (i) a thickness of between about 50 um and about 300 um, and (ii) between about 100 um and about 200 um. 22. The method according to claim 20 or 21,
Wherein the flexible substrate has at least one of a density of about 2.3 to 2.5 g / cc, a Young's modulus of about 70 to 80 GPa, a Poisson's ratio of about 0.20 to 0.25, and a minimum bending radius of about 185 to 370 mm. . 23. The method according to any one of claims 20 to 22,
Wherein the carrier substrate is formed from glass. 24. The method according to any one of claims 20 to 23,
Wherein the carrier substrate has a thickness of at least about 400 microns to about 1000 microns.

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