Systems and methods for manufacturing flexible electronics - Patents.com

Abstract

Systems and methods for manufacturing flexible electronics are described herein. Methods according to embodiments of the present technology can include disposing electrical features, such as thin-film circuits, on a first side of a glass substrate, applying a first protective material over the electronic features, and exposing a second side of the glass substrate to a chemical etching bath to thin the glass substrate to a predetermined thickness. The thinning process can remove cracks and other defects from the second side of the glass substrate to increase the flexibility of the electronic assembly. A second protective material can be disposed on the second side of the thinned glass substrate to maintain a strengthened backside of the glass substrate. In some embodiments, the method also includes singulating the multiple electronic features into individual electronic components by immersing the electronic assembly in a chemical etching bath.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 834,720, filed April 16, 2019, which is incorporated herein by reference in its entirety.

[0002]

[0002] The present technology relates to manufacturing flexible electronics. More particularly, the present technology relates to methods for manufacturing high performance, low cost electronic components. [Background technology]

[0003]

[0003] The growing interest in flexible displays (e.g., organic light emitting diodes ("OLEDs"), liquid crystal displays ("LCDs"), and electronic paper displays ("EPDs")), sensors, and near field communication ("NFC") based devices has led to the evolution of large area flexible electronics. Most of these flexible electronics utilize thin film transistor ("TFT") arrays containing electronic components formed in a polyimide ("PI") material. PI is useful because it is highly flexible and can essentially insulate the electronics. During fabrication, a layer of PI is laminated to a mother glass (e.g., a rigid, durable glass) or other type of substrate to provide a rigid backing, and the electronic circuitry is formed in the overlying PI layer. The PI layer is then peeled off from the mother glass and then laminated to a flexible substrate, such as a polyethylene terephthalate ("PET") substrate, to provide mechanical support for the flexibility.

[0004]

[0004] This manufacturing process poses many technical challenges due to the large differences in mechanical, thermal, and chemical properties between flexible organic substrate materials and rigid inorganic TFT materials. For example, the heat inherent in the manufacture of electronic devices can cause various types of defects in the TFT and PI layers unless high-quality, expensive PI is used. The lower temperature tolerance of PI substrates compared to TFT glass requires reduced processing temperatures for thin-film devices fabricated on PI substrates, thereby limiting the full potential of device performance. Furthermore, the need for thermal resistance and mechanical durability limits the available options for flexible substrates used to back the PI layer (after the electronics are fabricated). Summary of the Invention

[0005]

[0005] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, with emphasis instead being placed on clearly illustrating the principles of the present disclosure. Similarly, for purposes of discussion regarding some of the implementations of the present technology, some components and / or operations may be separated into different blocks or combined into a single block. For ease of reference, the same reference numbers and / or letters are used throughout this disclosure to identify similar or similar components or features, but the use of the same reference numbers does not imply that these parts should be interpreted as being identical. In fact, in many examples described herein, components with the same numbers refer to different embodiments that are structurally and / or functionally separate. [Brief description of the drawings]

[0006] [Figure 1] 1 is a partial schematic cross-sectional view of an electronic assembly. [Figure 2A]

[0007] 1 is a partial schematic cross-sectional view of an electronic assembly manufactured in accordance with some embodiments of the present technique; [Figure 2B]

[0008] 2B is an exploded cross-sectional view of the electronic assembly of FIG. 2A during an intermediate stage of a manufacturing process in accordance with an embodiment of the present technique. [Figure 2C]

[0009] 2C is a partial schematic cross-sectional view of the electronic assembly of FIG. 2B at a subsequent manufacturing stage in accordance with some embodiments of the present technique. [Diagram 3]

[0010] FIG. 1 is a block diagram illustrating a process for manufacturing flexible electronics directly on glass in accordance with an embodiment of the present technology. [Figure 4A]

[0011] 1 is an isometric view illustrating a method of manufacturing an electronic assembly in accordance with an embodiment of the present technique; [Figure 4B] 1 is an isometric view illustrating a method of manufacturing an electronic assembly in accordance with an embodiment of the present technique; [Figure 4C] 1 is an isometric view illustrating a method of manufacturing an electronic assembly in accordance with an embodiment of the present technique; [Figure 4D] 1 is an isometric view illustrating a method of manufacturing an electronic assembly in accordance with an embodiment of the present technique; [Diagram 5]

[0012] FIG. 1 is a block diagram of a roll-to-roll process for manufacturing flexible electronics in accordance with some embodiments of the present technique. [Figure 6]

[0013] 1 is a partial schematic diagram illustrating a roll-to-roll process for manufacturing electronic assemblies in accordance with some embodiments of the present technique. [Figure 7A]

[0014] 1A-1D are cross-sectional side views illustrating a method of manufacturing an electronic component according to an embodiment of the present technology. [Figure 7B] 1A-1D are cross-sectional side views illustrating a method of manufacturing an electronic component according to an embodiment of the present technology. [Figure 7C] 1A-1D are cross-sectional side views illustrating a method of manufacturing an electronic component according to an embodiment of the present technology. [Figure 7D] 1A-1D are cross-sectional side views illustrating a method of manufacturing an electronic component according to an embodiment of the present technology. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007]

[0015] Systems and methods for manufacturing flexible electronics, such as large area flexible electronics based on thin film circuits, are described herein. In some embodiments, for example, the systems and methods described herein form electrical features (e.g., TFTs and other thin film circuits) directly on a glass substrate and thin the glass substrate to serve as a base for packaged flexible electronic components. The systems and methods disclosed herein can also remove microcracks and other defects (pre-existing in the glass or introduced by handling during electronics manufacturing) from the surface of the glass substrate and / or the electrical components that are then singulated. This provides a low-cost, high-yield manufacturing process due to the good match between the mechanical, thermal, and chemical properties of the glass substrate material and the inorganic thin film circuit materials.

[0008]

[0016] Specific details of some embodiments of the present technology are described below with reference to FIGS. 1-7D. Although many of the embodiments are described below with reference to systems and methods for manufacturing flexible electrical components for flexible biometric sensors, other applications and other embodiments are within the scope of the present technology in addition to those described herein. For example, the present technology can be used to manufacture electrical components for flexible displays, such as flexible LCDs and OLEDs. In addition, some well-known structures or functions may not be shown or described in detail to avoid unnecessarily obscuring the relevant description of the various embodiments. Furthermore, some other embodiments of the present technology may have different configurations, components, or procedures than those described herein, and features of the illustrated embodiments may be combined with each other. Thus, those skilled in the art will accordingly understand that the present technology can have other embodiments including additional elements, or that the present technology can have other embodiments that do not include some of the features shown and described below with reference to FIGS. 1-7D.

[0009]

[0017] In some embodiments, the technology can be used to fabricate thin film circuits such as TFTs and other thin film electrical features on flexible glass for use in biometric authentication systems such as fingerprint sensors and Biometric Systems on Cards (BSoCs). TFTs are a special type of metal oxide semiconductor field effect transistor (MOSFET) that can be made by depositing thin films of active semiconductor and dielectric layers on a supporting substrate. The resulting flexible electronic components such as flexible fingerprint sensors or flexible LCDs and OLEDs can then be integrated into electronic systems such as BSoCs or flexible displays. The flexibility of the resulting electronic system may be limited by the flexibility of the substrate underlying the TFTs, in part due to microcracks and / or other defects or impurities introduced into the substrate during fabrication. Those defects or impurities undergo mechanical stress from bending, impact, etc., leading to failure points in the electronic system.

[0010]

[0018] One method of manufacturing these flexible electronic components involves selecting a core substrate with high flexibility, such as a polyimide substrate. However, polyimide is very flexible and therefore must be further laminated to at least one other more rigid substrate (typically two different substrates: one used during the formation of the electronic features and one used for subsequent integration into the electronic system) to support the formed electrical features. The complex manufacturing process and the high quality cost of polyimide required for thin film circuits can bring significant costs to the manufacturing process.

[0011]

[0019] The systems and methods disclosed herein fabricate electronics directly on flexible glass substrates. In some embodiments, for example, the technology uses a sheet-to-sheet manufacturing process typically used to fabricate electronics on a polyimide substrate supported by a rigid glass substrate, but instead removes the polyimide and places thin-film electronic features directly on the glass substrate. In these embodiments, the method can include placing a plurality of electronic features (e.g., TFTs and other thin-film circuitry) on a first side of the glass sheet. To increase flexibility, the back side of the glass sheet can then be chemically thinned to remove cracks, impurities, or other possible failure points from the surface of the flexible glass sheet. The method can then be laminated or coated with a protective laminate on the back side of the sheet. In some embodiments, the method can continue by singulating the sheet into individual electrical components using chemical dicing techniques. For example, the glass can be partially imprinted by a laser (e.g., as a continuous line or multiple spaced indentations that create a perforated surface) to define a cut track around the individual electronic components, and then the sheet can be immersed in a chemical etching bath to complete the singulation along the cut track. After singulation, a protective coating (eg, a liquid polymer) may be formed on the exposed surfaces and edges of the individual electronic components.

[0012]

[0020] The flexible electronic components manufactured using the processes described herein include flexible glass substrates that have a higher fracture stress than the electronic features being manufactured. Thus, in some embodiments, during or after singulation, the outer edges and surfaces of the electronic components can be chemically etched to remove near-surface microcracks around the outer edges to increase the fracture stress and possibly remove other impurities that may be susceptible to breakage. In some embodiments, the methods and systems disclosed herein include roll-to-roll manufacturing processes using flexible glass laminates.

[0013]

[0021] In some embodiments, the method can include chemically thinning the flexible glass substrate via a roll-to-roll process to remove defects from the flexible glass substrate. The method can then apply a protective coating to one surface of the glass substrate while leaving the opposite surface exposed for electronics manufacturing (e.g., thin film deposition). In some embodiments, the method can utilize a roll-to-roll manufacturing process to deposit a plurality of individual electronic features on the exposed surface of the flexible glass substrate, thereby providing a high-throughput manufacturing process. In some embodiments, the method can then perform singulation to separate the plurality of electronic features on the flexible glass substrate into a plurality of electronic components.

[0014]

[0022] FIG. 1 is a partial schematic cross-sectional view of a packaged electronic assembly 110 fabricated by current TFT processing techniques. The electronic assembly 110 has a polyimide ("PI") substrate 112 (also referred to as a "PI layer 112") that serves as the core of the electronic assembly 110, a flexible support substrate 122 (e.g., a PET substrate) that holds the PI substrate 112, and electronic features 130 (e.g., multiple thin film circuits for a biometric sensor, etc.) carried by the PI substrate 112. As further shown in FIG. 1, the electronic assembly 110 also includes a first or top protective film 142 disposed over the electronic features 130 and a second or bottom protective film 144 disposed on a bottom surface of the flexible substrate 122. In some applications, after fabrication is otherwise completed, the first protective film 142 is removed to expose the electronic features 130, for example to enable electronic connections to the electronic features 130.

[0015]

[0023] The electronic assembly 110 is formed by removably bonding (e.g., laminating) the PI substrate 112 to a temporary support substrate (not shown) and then forming the electronic features 130 on the PI substrate 112. The temporary support substrate can be a rigid material such as glass (i.e., called a "mother" glass substrate or sheet) to provide support to the highly flexible PI substrate 112 as the electronic features 130 are formed, and also has material properties that match the PI substrate 112 as both undergo semiconductor processing steps. After the electronic features are formed, the backside of the temporary support substrate is exposed to a laser, which melts and / or vaporizes the adhesive between the temporary support substrate and the PI substrate 112, thereby allowing the PI substrate 112 to be completely removed from the temporary support substrate. The PI substrate 112, including the electronic components, is then laminated to a flexible substrate 122. The electronic assembly 110 can be highly flexible due to the small bending radius of the support substrate 122 and the PI substrate 112. However, the complexity of the manufacturing process can be expensive and can reduce the fabrication yield. For example, peeling the PI substrate 112 from the temporary support substrate may cause portions of the PI substrate 112 to evaporate, allowing removal from the temporary glass support. Additionally, some materials are suitable for the flexible support substrate 122, and both the flexible support substrate 122 and the PI layer 112 may be temperature sensitive. The temperatures reached to laminate the PI layer 112 to the flexible substrate 122 may cause deformations and / or other manufacturing defects that reduce fabrication yields.

[0016]

[0024] 2A is a partial schematic cross-sectional view of an electronic assembly 210 manufactured according to an embodiment of the present technology. The electronic assembly 210 includes a thin flexible glass substrate 221 (also referred to as "glass substrate 221") and electronic features 230 (e.g., TFTs and other thin film circuits) disposed directly on a first side of the glass substrate 221. In some embodiments, a first protective film 242 (not shown) can be disposed on the electronic features 230 to protect them during manufacturing, and a second side of the glass substrate 221 is covered by a second protective film 244. In the illustrated embodiment, the first protective film 242 has been removed to expose the electronic features 230 for later use (e.g., as a sensor), and the second protective film 244 remains to continue to protect the glass substrate 221. Manufacturing electronic devices directly on the glass substrate 221 can increase manufacturing efficiency and device performance, reduce costs, and increase fabrication yields. For example, the manufacturing process involves fewer steps and eliminates the need to laminate and delaminate a PI substrate to a temporary glass support substrate for the manufacture of electronic devices, and then laminate to a more rigid plastic backing to complete the fabrication. The glass substrate 221 is also more resistant to the heat inherent in manufacturing, more resistant to scratching or denting, and / or easier to manipulate than the flexible support substrate of the electronic assembly 110 of FIG. 1. Flexible glass, such as that used for the glass substrate 221, typically contains small microcracks and other defects on the surface that can limit the reliability and flexibility of the resulting electronic assembly 210. Thus, the present technique removes or substantially eliminates such cracks and defects to provide a reliable flexible glass substrate.

[0017]

[0025]

[0026] In particular, the fracture stress σ f is determined by equation (1).

[0018]

number

[0019] In the formula, K lc is the fracture toughness of the glass, α is a geometric parameter (typically around 1.12 for surface or edge cracks in the glass), and a is the maximum length of a crack that can exist in the glass. lc and α are dictated after the type of glass or other flexible substrate is selected, and the crack length a remains a variable in the denominator of equation (1). Thus, reducing the crack length a on the surface and / or edge of the glass correspondingly increases the fracture stress on the glass. Increasing the flexibility of the glass also increases the flexibility of the electronic unit that uses the glass. The present technology includes systems and methods that reduce and / or nearly eliminate surface cracks and other defects in glass used to fabricate flexible electronic components.

[0020]

[0027] FIG. 2B is an exploded cross-sectional view of the electronic assembly 210 of FIG. 2A during an intermediate stage of a manufacturing process according to an embodiment of the present technology. The flexible glass substrate 221′ is in a pre-thinned state and has a first side 225a (also called “upper side”, “front side”, or “electronics side”) including a first surface 222 (also called “top side”, “front side”, or “electronics side”), a second side 225b (also called “lower side” or “back side”) including a second surface 224′ (also called “lower side” or “back side”) opposite the first side 225a, and a thickness between the first surface 222 and the second surface 224′. As shown in FIG. 2B, the electronic features 230 are disposed on the first surface 222 and are then covered by a first top protective film 242. The first surface 222 is substantially free of impurities, whereas the second surface 224′ includes a plurality of cracks and / or defects. For example, the second surface 224' includes a crack having a length a. These cracks and other defects may arise as a result of the process of manufacturing the flexible glass substrate 221' itself and / or the process of manufacturing the electronics on the first surface 222 of the flexible glass substrate 221' (e.g., during backside robotic handling). In the illustrated embodiment, the fracture stress of the electronic assembly 210 is limited by the fracture stress of the flexible glass substrate 221' and can be calculated using Equation (1) and the length a of the crack.

[0021]

[0028] FIG. 2C is a cross-sectional view of the electronic assembly 210 of FIG. 2B at a next manufacturing stage according to some embodiments of the present technology, where the flexible glass substrate 221 has been processed to remove defects. As shown in FIG. 2C, the flexible glass substrate 221 has been thinned to a predetermined thickness by removing substrate material from the second side 225b (FIG. 2B) of the glass substrate 221 to define a new second surface 224. The glass substrate 221 can be thinned by partially or fully immersing the electronic assembly 210 in a chemical etching bath that exposes the second side 225b to chemicals that remove material from the second side 225b, while the protective film 242 prevents the chemical bath from affecting the electronic features 230 of the first side 225a of the electronic assembly 210. In some embodiments, other suitable thinning techniques can be used to thin the second side 225b of the glass substrate 221. Removing substrate material from second side 225b also removes cracks and other defects to form second surface 224 that is at least substantially free of cracks and defects. As a result, the failure stress of electronic assembly 210 is significantly improved (e.g., the length a of any cracks that enter into the denominator of equation (1) is significantly reduced). In some embodiments, second protective coating 244 can be applied immediately after removing defects from bottom surface 224. In some embodiments, second bottom protective coating 244 can be selected based on mechanical protective qualities (e.g., scratch resistance, impact attenuation, durability, etc.) and chemical protective qualities (e.g., protection from exposure to acid).

[0022]

[0029] As a result of thinning the glass, the breaking stress of the flexible glass substrate 221 is significantly higher than the original glass substrate 221' of FIG. 2B. Additionally, thinning the substrate increases the flexibility or bendability of the electronic assembly 210, enabling flexible applications such as cards including biometric sensors. In some embodiments, for example, the breaking stress allows the electronic assembly 210 to bend to a bend radius of about 40 mm to about 30 mm before breaking. In other embodiments, the bend radius can be less than 30 mm or greater than 40 mm, depending on the degree of thinning, the materials and structure of the electronic assembly 210, and / or the specifications for the desired use (e.g., embedded in a flexible card, flexible display, or wearable sensor).

[0023]

[0030] 3 is a block diagram illustrating a process 300 for fabricating flexible electronics directly on flexible glass according to an embodiment of the present technology. The sheet-to-sheet process 300 can be used to improve the flexibility of the glass after TFTs, other thin film circuitry, and / or other electronic features have been formed on a first surface of the glass substrate. The process 300 can be used to reduce or remove cracks and other defects from the backside of the glass substrate, to separate sheets containing multiple electronic features into individual electronic components without introducing new impurities, and / or to apply protective films and / or coatings to the electronic components.

[0024]

[0031] The process 300 can include disposing thin film circuitry (e.g., TFTs) or other flexible electronic features on a first side of a glass sheet substrate. In some embodiments, the electronic features are already formed on the glass substrate. As shown in FIG. 3, in block 305, the process 300 applies a protective film to the first side of the sheet over the electrical features. The protective film provides a material barrier that protects the electronic features from exposure to chemicals, heat, and / or other external exposure during later stages of the process 300. In some embodiments, the protective film on the first side of the sheet is applied for temporary use, for example, using an adhesive that can be removed later. In some embodiments, the protective film permanently adheres over the electronic features and the first side of the glass substrate. The protective film can be a PET film having a thickness of about 50 μm to about 500 μm.

[0025]

[0032] At block 310, the process 300 exposes the second side of the glass sheet to a chemical solution to chemically remove material from the second side of the glass and thin the glass sheet to a predetermined thickness. Chemical thinning is used to remove cracks, defects, and / or impurities from the second surface of the glass. For example, these cracks, defects, and / or impurities in the glass are primarily present in the outer region of the glass substrate that extends from the outer surface of the glass to a depth into the glass substrate. The chemical solution peels this outer layer away without introducing new cracks, defects, and / or impurities, leaving a smooth surface with little or no cracks, defects, and / or impurities. In some embodiments, the chemical etching step (block 310) etches away about 0.2 mm to about 0.3 mm from the second side of the sheet. In some embodiments, the chemical etching step (block 310) etches away at least 0.3 mm of glass on the second side of the sheet, for example, to ensure removal of deeper cracks present on the second side of the glass sheet substrate, thereby reducing the effect of such cracks on the material properties (e.g., flexibility) of the glass. Additionally, the chemical etching also reduces the overall thickness of the glass sheet (e.g., to 0.5 mm to 0.2 mm or less), thereby increasing the flexibility (e.g., bend radius) of the subsequently singulated electrical components.

[0026]

[0033] The chemical solution includes a hydrofluoric acid solution and / or other chemicals that etch the glass. In some embodiments, the thinning step of block 310 includes fully immersing the sheet (glass substrate and electrical components disposed thereon) in a chemical etchant bath (also referred to as a "chemical bath") containing the chemical solution to controllably dissolve all exposed surfaces of the sheet. A protective film can protect the electronic features from exposure to the chemical solution so that only the desired surfaces are etched. In some embodiments, the thinning step of block 310 includes only partially immersing the second surface in the chemical etchant bath and / or directing the chemical solution through a hose and nozzle to the second surface to controllably dissolve selected exterior surfaces of the sheet. In some embodiments, the glass substrate of the sheet is thinned from a thickness of about 0.5 mm to a thickness of about 0.05-0.2 mm, about 0.05 mm, about 0.15 mm to about 0.08 mm, or about 0.15 mm.

[0027]

[0034] At block 315, the process 300 applies a second protective coating to the second side of the sheet (i.e., the back side of the thinned glass) to provide mechanical and / or chemical protection for the cleaned surface and to avoid the formation of subsequent cracks or other defects. The second protective coating can be applied by a lamination process, a coating process, or other suitable method known in the art.

[0028]

[0035] The second protective film can be constructed from plastic materials, organic films such as PET, inorganic-organic hybrid materials, and / or nanocomposites such as nanosilica particles in epoxy, urethane, and / or acrylic. In some embodiments, the first and second protective films are composed of the same material. In other embodiments, the first and second protective films are constructed from different materials. In some embodiments, the second protective film is selected based on its mechanical qualities. For example, the second protective film can be a permanent protective film and therefore can be selected to have damping or high shock absorption properties to protect the flexible electronic device from damage due to impact. In some embodiments, the second protective film is permanently coated on the second surface. In some embodiments, the second protective film does not dissolve or dissolves very slowly when exposed to a chemical solution (e.g., hydrofluoric acid) that can be used, for example, in further chemical steps described below. In some embodiments, the second protective film and / or the thickness of the second protective film can also be selected based on the flexibility of the material. In some embodiments, the second protective film can have a thickness of about 50 μm to 500 μm.

[0029]

[0036] The sheet can include electronic features that define a plurality of electronic components. In these embodiments, process 300 continues with blocks 320 and 325 for device singulation. At block 320, process 300 uses a laser to inscribe the sheet to define cut tracks that define boundaries between individual electronic components (e.g., individual displays, sensors, etc.). The laser inscription can form the cut tracks (e.g., indentations or recesses) from a first side and / or a second side of the glass substrate. In some embodiments, the first and / or second protective film can be transparent alignment tracks (also called alignment guides, lines, or aids) deposited on the underlying material (e.g., glass substrate) to precisely indicate the cut tracks during a previous manufacturing step (e.g., during formation of the electronic features). These alignment guides can then be used to guide the laser during the inscription process that forms the cut tracks. In some embodiments, the cut tracks can be pre-set and loaded into a computer system (e.g., a software application) that guides the laser. In various embodiments, the laser can be selected from various laser types (e.g., diode-pumped solid-state lasers with IR wavelengths) with appropriate frequencies or wavelengths, and the energy density and power density of the laser pulses can be controlled uniformly in the spatial domain, for example, by PSO (position-synchronized output) techniques. Controlling the wavelength, pulse energy, and / or power density can allow control of the shape and depth of the etched cut track. Furthermore, in various embodiments, the laser can be used by single-focus or multi-focus methods.

[0030]

[0037] In some embodiments, the laser marking can include using a laser to mark a continuous (e.g., unbroken) line in the cut track. In these embodiments, the cut track can extend only partway through the sheet. In some embodiments, the laser can be used to form (i.e., "drill") holes that are periodically spaced from one another along the sheet to define the cut track. Such a cut track resembles a perforation line. In some embodiments, the laser material process described above can be performed on only one side of the sheet. For example, the laser can be used to mark a continuous line on only the first surface. In other embodiments, the laser marking process can be performed on both sides. In these embodiments, the laser marking can be performed on both sides simultaneously or sequentially on each side. Compared to mechanical cutting, laser etching significantly reduces the introduction of new cracks and chips into the sheet as well as reducing residual stresses due to contact during mechanical cutting.

[0031]

[0038] Laser inscription does not completely cut (i.e., singulate) the individual electrical components, in part because the continued exposure to heat required to completely cut the sheet can cause small microexplosions at the cut surface, resulting in small cracks and / or other impurities in the glass exposed to the laser.

[0032]

[0039] Thus, at block 325, process 300 continues by smoothing any new cracks or defects along the exposed surfaces (e.g., sidewalls of the individual electronic components) while exposing the sheet to a chemical etchant that completes the singulation of the individual electronic components. In particular, the chemical etching process (block 325) dissolves the sheet along the cut tracks that were exposed from the protective film during laser marking. Chemical dicing can also form smooth rounded edges, thereby reducing potential breakage points and removing at least a portion of the cracks or other defects introduced into the glass or other material during laser marking.

[0033]

[0040] In some embodiments, chemical dicing (block 325) can be completed by immersing the sheet in a chemical etching bath. In some embodiments, the chemical etching bath can be the same bath used to chemically thin the flexible glass in block 310. In some embodiments, the chemical etching can be accomplished using hoses and nozzles to direct the chemical solution to the cutting track.

[0034]

[0041] In some embodiments, process 300 is used to manufacture stand-alone electronic components and / or cooperating electronic devices without the need for singulation. In these embodiments, process 300 omits the steps of blocks 315 and 320 and proceeds directly to block 330.

[0035]

[0042] At block 330, process 300 proceeds by applying a protective coating to the singulated electronic components. This protective coating (also referred to as a "protective coating" or "protective film") may be applied to the newly exposed sides of the singulated electrical components to protect against the external environment and to avoid cracks or other defects. A protective coating may additionally or alternatively be applied to the second side of the glass substrate (over a previously applied protective film) and / or over the electronic features on the first side of the glass substrate (over a previously applied protective film). In various embodiments, the protective films on the first and second sides may be removed in favor of applying a final protective coating.

[0036]

[0043] In some embodiments, the protective coating step of block 330 can include a series of steps as well. For example, in some embodiments, block 330 includes a first step of coating the electronic units (individually or in a sheet) with a liquid polymer, a second step of soft-baking the electronic units to partially cure the liquid polymer, a third step of removing the first protective coating, thereby exposing a first surface of the electronics and allowing the electronics to receive, for example, electrical contacts, and a fourth step of hard-baking to finish curing the liquid polymer. In various embodiments, the electronic units can be coated with the liquid polymer via dip coating, spray coating, nozzle printing, etc., or the electronic units can be placed horizontally on a chuck having a holding cell for the electronic units, and a programmable polymer solution dispenser (e.g., an inkjet printer) can dispense the polymer solution around all edges of the electronic units.

[0037]

[0044] In some embodiments, the chemical thinning described in block 310 and the chemical dicing described in blocks 320-325 can occur during the same stage of process 300. For example, in some embodiments, immediately after the first protective film is applied over the electronics layer, the sheet can be laser engraved with a cut track and then immersed in a chemical bath to simultaneously thin the glass by dissolving the second surface and complete the chemical etching process. In these embodiments, the laser etching process can be calibrated to etch the cut track that allows enough material to dissolve from the second surface when dissolving the cut track. In some embodiments, after singulation, a second protective film can be applied to the individual electronic components before they are coated with a polymer in block 330. In other embodiments, the individual electronic components can be directly coated with a polymer in block 330.

[0038]

[0045] 4A-4D are isometric views showing an electronic assembly 410 (also referred to as "sheet 410") including multiple individual electronic features 432 at various stages in the sheet-to-sheet process described above with reference to FIG.

[0039]

[0046] FIG 4A shows a sheet 410 at an early stage in the manufacturing process. The sheet 410 includes a glass substrate 421 having a first portion 422 that includes a low level of defects (e.g., cracks) and a second portion 424 that has a higher level of defects. As shown in FIG 4A, the second portion 424 extends a distance into the glass substrate 422 from an outer surface of the glass substrate 421. A plurality of discrete electronic features 432 are disposed on a top surface (e.g., a first surface) of the glass substrate 421 that is covered by a first protective film 442. In one embodiment, the sheet 410 is then immersed in a chemical bath to thin the glass.

[0040]

[0047] FIG. 4B shows the sheet 410 after a chemical thinning process. The chemical thinning process can include immersing at least the second side of the sheet 421 in a chemical etching bath and / or directing a chemical etchant toward the second side of the sheet 421. The chemical dissolves a portion of the glass substrate to a predefined depth from the exposed surface. A first protective film 442 prevents the chemical etchant from removing or otherwise affecting the underlying electronic features 432. As shown in FIGS. 4A and 4B, a chemical etchant is applied to the underside (e.g., second surface), thereby dissolving the defect-rich second portion 424 and exposing the defect-reduced underlying first portion 422. As further shown in FIG. 4B, the first portion can be covered with a second protective film 444. At this stage, the sheet 410 is ready to be singulated into individual electronic components.

[0041]

[0048] FIG. 4C shows the sheet 410 in the next processing step after cut tracks 470 have been formed to define boundaries around the individual electronic components. In the illustrated embodiment, the cut tracks 470 are formed on both sides of the sheet 410 and extend partially through the protective films 442, 444 into the glass substrate 422. In some embodiments, the cut tracks 470 are formed on only one side of the glass substrate 422 and / or extend only to the surface of the glass substrate 422 (and not into the glass substrate 422). The cut tracks 470 can be engraved using a laser and / or other suitable perforation forming means. In the illustrated embodiment, the cut tracks 470 are continuous lines (e.g., trenches, elongated recesses, or valleys) spaced apart from one another to define boundaries of the individual electronic components. In some embodiments, the cut tracks 470 are a series of spaced apart dashed lines or holes (e.g., similar to perforations in paper) along the top and / or bottom surfaces of the sheet 410. When sheet 410 is exposed to a chemical etchant, the chemical can contact glass 421 through cut tracks 470 and dissolve glass 421 radially inward. If cut tracks 470 are deep enough, the plurality of electronic components 432 can be separated into a plurality of individual electronic units 413 before the chemical etchant dissolves any substantial portion of the individual electronic units 413 (FIG. 4D).

[0042]

[0049] FIG. 4D shows a plurality of singulated electronic components 413. The electronic components 413 each include an individual electronic feature 432 disposed on a flexible glass substrate 421. The flexible glass substrate 421 is thinned to increase the flexibility of the device and to remove defects from the underside that is coated with a second protective film 444. Chemical singulation can provide clean, smooth sidewalls without introducing additional cracks or other defects that would impede the flexibility of the components 413. In the illustrated embodiment, the individual components 413 are coated on their entire exterior surfaces with a final protective coating (not shown). The components 413 can be soft baked, the first protective film 442 can be removed to expose the individual electronic features 432, and then the components 413 can be hard baked to fully cure the final coating. It will also be appreciated that the plurality of electronic features 432 can be interconnected (thereby not requiring separation) such that separation results in any number of electronic features 432, including an entire sheet, being grouped together. Although each individual component 413 is shown as an individual electronic device, it will also be understood that the individual electronic features 432 may include multiple circuits and / or multiple subcomponents.

[0043]

[0050] In some embodiments, the discrete electronic components 413 may include some or all of the components for a flexible biometric sensor system that may be integrated into a flexible biometric card or other biometric sensing device. For example, the discrete electronic components 413 may include a fingerprint sensing area, an ASIC, and a microcontroller. By fabricating some or all of the components for a fingerprint sensor, the process 300 may be used to fabricate a flexible fingerprint sensor, for example, for use in a BSoC. Because the sensor is fabricated using this technique, the BSoC is able to withstand large amounts of mechanical stress, extending the life of the BSoC. Full details regarding the components of a biometric system according to some embodiments of the present technology are described in U.S. Pat. No. 9,792,516 B2, which is incorporated herein by reference in its entirety.

[0044]

[0051] 5 is a block diagram of a roll-to-roll process 500 for manufacturing flexible electronics in accordance with some embodiments of the present technology. The roll-to-roll process 500 uses some of the methods discussed above with respect to Figures 2A-4D adapted for use in a roll-to-roll system.

[0045]

[0052] At block 505, the process 500 provides a flexible roll substrate (e.g., flexible glass substrate, laminate) for the manufacturing process. In some embodiments, preparing the flexible substrate includes chemically thinning the flexible glass substrate to remove cracks and other defects in the outer surface area remaining from previous manufacturing processes and / or pre-manufacturing handling. In some embodiments, preparing the flexible glass substrate includes applying a protective film to a bottom surface of the flexible substrate, thereby forming a laminate. In these embodiments, the protective film can provide mechanical and chemical protection to the bottom surface to reduce the introduction of defects when manufacturing electronics on the top surface. After the flexible glass substrate is otherwise prepared, it is wound into a roll and configured in a roll-to-roll manufacturing system.

[0046]

[0053] At block 510, the process 500 continues by forming electronic features on a front or first surface of the flexible glass substrate. For example, this can include rolling the flexible glass substrate through one or more semiconductor fabrication modules configured to deposit electronic features on the front or first surface of the glass substrate. In some embodiments, the modules can be used to achieve low temperature polycrystalline silicon (LTPS) fabrication. In one embodiment, for example, the flexible substrate is passed through a first film deposition module that deposits one or more layers of a plurality of TFTs on the top surface of the substrate, a second module for photolithographic patterning, a third module that etches and strips the deposited film, a fourth module that inspects the TFTs, and / or a fifth module that deposits a final layer on top. In various embodiments, the fabrication process 500 can include other TFT-related modules, can omit some of those described, and / or can include different semiconductor processing modules. For example, the manufacturing process 500 may also include any other suitable functional modules, such as laser crystallization processes, ion doping processes, activation processes, and various annealing. Furthermore, it will be appreciated that all of the manufacturing processes associated with the electronic units being fabricated may be performed in a single module, two modules, or any number of modules. It will also be appreciated that the roll-to-roll process may be used to fabricate other electronic units other than TFTs, which may require completely different modules than those described above as examples. After the electronics are formed on the flexible glass substrate, the unfolded roll may include features similar to the spaced apart sheets of electrical features described above with respect to Figures 4A-4D.

[0047]

[0054] At block 515, the roll can be separated into individual sheets. This can be accomplished in a variety of ways. In some embodiments, the separation can adapt a chemical dicing process as described above with respect to blocks 320 and 325 of FIG. 3 to separate the individual sheets. For example, a laser can be used to etch a cut track that defines the boundary between the sheets, and a chemical bath can be used to complete the separation. In embodiments where the sheet includes a single electronic unit (or multiple electronic devices working together), incorporating a chemical etching process into the separation can reduce the number of defects introduced at the edges of the sheet. In embodiments where further singulation is performed to separate the sheet into multiple individual electronic components 413 (FIG. 4D), defects introduced by a conventional cutting mechanism can be subsequently removed by a chemical dicing singulation process.

[0048]

[0055] At block 520, process 500 may continue using chemical dicing to complete the singulation. In various embodiments, the process may follow the steps discussed above with respect to blocks 320 and 325 of FIG. 3. That is, at block 520, process 500 may use a combination of laser and chemical etching processes to complete the separation into individual electronic components. In these embodiments, the chemical etchant used to complete the singulation may also be used to reduce defects introduced by the separation of the sheets at block 515.

[0049]

[0056] It will be appreciated that in some embodiments, process 500 can omit block 515. For example, in some embodiments, the roll can be passed through a singulation module, which continuously completes a chemical dicing process directly on the roll, to singulate the individual electronic components.

[0050]

[0057] At block 525, the process applies a final protective coating to the resulting electronic product (e.g., separated sheets, multiple individual electronic units, etc.). In various embodiments, the process may follow the steps discussed above with respect to block 330 of Figure 3 to apply the final coating. For example, in one embodiment, the process loads the individual electronic units onto a horizontal chuck, spray coats the individual electronic units, soft bakes the individual electronic units, removes the protective film from the top surfaces of the individual electronic units, and / or hard bakes the individual electronic units.

[0051]

[0058] FIG. 6 is a partial schematic diagram illustrating a roll-to-roll process that can be used by one embodiment of the process 500 of FIG. 5. In the illustrated embodiment, the process 600 uses a first roll 602, a second roll 604, and a third roll 606. At the start of the process, a flexible substrate (e.g., a flexible glass substrate) is wound on the first roll 602. The flexible substrate is then unrolled from the first roll 602 and wound on the second roll 604 through a series of modules 611-615. In some embodiments, the first roll 602 withstands winding onto the second roll 604 to provide tension to the flexible substrate through the manufacturing process.

[0052]

[0059] In the illustrated embodiment, the flexible substrate is pulled by modules 611-615 as it is wound onto the second roll 604. It will be appreciated that the total number of modules, as well as which manufacturing process is performed in each module, can be varied as appropriate depending on the electronic components to be deposited on the top surface of the flexible substrate. In one embodiment, for example, modules 611-615 can correspond to various modules associated with the manufacturing of TFTs discussed above. That is, in one embodiment, module 611 can be a film deposition module, module 612 can be a photolithography patterning module, module 613 can be an etching and stripping module, module 614 can be an inspection module, and module 615 can be a second film deposition module.

[0053]

[0060] In the illustrated embodiment, after the manufacturing of the electronic devices is completed, the second roll 604 is moved to another station in preparation for singulation. At the second station, the flexible substrate is unrolled from the second roll 604 and wound onto a third roll 606. In some embodiments, the second roll 604 withstands the winding of the third roll 606 to create a constant tension in the flexible substrate throughout the singulation preparation.

[0054]

[0061] In the illustrated embodiment, the flexible substrate is pulled by various modules 622 and 624 as it is wound onto the third roll 606. It will be appreciated that the total number of modules, as well as which processes are performed in each module, can be varied as appropriate depending on the singulation process. In one embodiment, for example, modules 622 and 624 can be used to prepare the roll to be separated into individual electronic units by applying a protective film to the electronics and etching cut tracks around the individual electronic units. For example, module 622 can be used to apply a protective film to the top surface of the flexible substrate. As discussed above, the protective film can be temporarily laminated to the top surface, for example, to protect the individual electronic units and the top surface from chemical and mechanical damage during singulation. Additionally, module 624 can be a laser etching module used to perform the first step of the chemical dicing process. In one embodiment, for example, module 624 can use a laser to inscribe a continuous cut track into the flexible substrate. As discussed above, the laser inscription process can be performed on the top surface, the bottom surface, or both surfaces.

[0055]

[0062] After imprinting the cut tracks into the flexible substrate, the flexible substrate can be rolled out from the third roll 606 into a chemical etching bath to complete the singulation in module 626. In some embodiments, after singulation, a final protective coating can be applied to the multiple individual units and / or a protective film can be removed from the top surface.

[0056]

[0063] When electronic devices are manufactured by the above-mentioned methods, the flexibility of flexible substrates such as flexible glass can be significantly increased, so that the flexible substrate, when bent or flexed, does not develop failure points when subjected to mechanical stress. Conversely, electronic features disposed on the flexible substrate act as a limiting factor to the overall device flexibility (e.g., due to defects and / or sharp edges). Thus, the systems and methods disclosed herein can utilize chemical thinning to reduce and / or eliminate cracks and defects from flexible glass substrates, fabricate electrical features directly in the glass, and enable the integration of the resulting electronic components into flexible electronic systems (e.g., flexible cards, wearables, scanners, displays).

[0057]

[0064] 7A-7D are cross-sectional side views of an electronic component at various stages of fabrication to improve the flexibility of the electronic component according to some embodiments of the present technology. FIG. 7A shows a singulated electronic component 710 (also referred to as an "electronic device" or "electronic unit") in a first processing step. As shown, the electronic component 710 includes a flexible substrate 712 (e.g., glass) and electronic features 714 (e.g., thin film circuitry). The electronic component 710 has an exterior surface 715 (also referred to as a "first surface 715") and edges 716. These edges 716 can be formed by surfaces that connect sharp, thin apexes. In some embodiments, for example, the flexible substrate 712 can be flexible glass thinned by the process 300 described in FIG. 3, and the electronic features 714 can be relatively fragile TFTs fabricated by plasma enhanced chemical vapor deposition (PECVD) of silicon oxide, silicon nitride, indium tin oxide (ITO), and / or molybdenum (Mo).

[0058]

[0065] As shown in FIG. 7A, the exterior surface 715 includes a number of defects (e.g., cracks, edge defects, or impurities) that may result, for example, from stress during fabrication. For example, the final step of patterning thin film circuits often involves stripping the photoresist mask followed by water rinsing the thin film. Typically, ultrasonic agitation or other agitation means are used for fast and clean photoresist removal. However, the agitation and subsequent water rinsing tend to deteriorate the surface of the thin film, resulting in edge defects, scratches, and / or microcracks in the exterior surface 715. These defects are especially likely to occur around any exposed edges of the thin film, where there are typically high stress concentrations during agitation. Furthermore, similar to the defects discussed with respect to FIG. 2B, defects in the exterior surface 715 typically limit the flexibility of the electronic features 714. In embodiments where the electronic features 714 are TFT films fabricated by PECVD, the film material used is a relatively brittle material that cannot be replaced.

[0059]

[0066] Instead, in some embodiments of the present technology, a blanket etch process can be used to reduce surface defects in the exterior surface 715 of the electronic features 714. In some embodiments, the blanket etch process can use the same etchant used for etching during the manufacturing process described above. In some embodiments, if the TFT is manufactured by a process that includes an etching and stripping step, the blanket etch process can use the same etchant used to etch the membrane. In some embodiments, for example, the blanket etch process can use hydrofluoric acid in an ammonium fluoride solution with a HF:NH4F ratio of 1:7. In some embodiments, the etchant used can be more concentrated, which requires a very short exposure to remove the exterior surface 715 and thereby reduce defects in the electronic features 714. In some embodiments, the etchant can be more diluted, which requires a longer exposure during the process but provides more control.

[0060]

[0067] 7B shows electronic unit 710 after processing to remove defects or impurities from electronic component 714. As shown, exterior surface 715 has been removed to expose surface 717 having fewer defects or impurities. Additionally, edges 716 have been rounded, thereby reducing the amount of stress concentrated at edge 716. As a result of exposing surface 717 with fewer defects, the flexibility of electronic feature 714, and therefore electronic component 710, is improved.

[0061]

[0068] 7C illustrates an example of an electronic component 710 according to some embodiments of the present technology, with a protective film 720 disposed on a top surface 714 of the electronic component 710. In some embodiments, the protective film 720 can provide mechanical protection (e.g., against scratches, contact-induced stress, etc.) to the edges 716 and surface 717. In some embodiments, the protective film 720 can act as a planarizing layer over the top surface 714 of the electronic component 710. In some embodiments, the protective film 720 can be a photopatternable organic or inorganic-organic hybrid material, such as those typically used in fabricating high resolution LCD or OLED displays. Additionally, in some embodiments, the protective film 720 can be selectively applied to the top surface 714 of the electronic component 710.

[0062]

[0069] 7D illustrates an example of an electronic component 710 in accordance with some embodiments of the present technology, where a protective film 720 is selectively disposed on a top surface 714 of the electronic component 710. In the illustrated embodiment, the protective film 720 is disposed with via holes located over a portion of the electronic feature 714, thereby allowing layer 730 to contact the electronic feature 714. In some embodiments, for example, layer 730 can electronically couple the electronic feature 714 to other electronic components (not shown). In some embodiments, the electronic feature 714 can be a relatively fragile electrode (e.g., ITO or Mo) that is protected by the protective film 720 and can contact a relatively non-fragile electrode in layer 730.

[0063]

[0070] It will be understood that the schematic diagrams and electronic components 710 shown in Figures 7A-7D are shown for illustrative purposes only. Many variations of the embodiment can exist without departing from the underlying principles of the method for improving the flexibility of electronic devices. For example, although the electronic features 714 are shown to be directly on the substrate 712, there may be one or more thin films and / or other layers between the electronic features 714 and the substrate 712, and although a single substrate 712 is shown in Figures 7A-7D, the substrate 712 can also be made of multiple layers (e.g., a layer of flexible plastic material (such as PI) laminated to a rigid carrier substrate (e.g., rigid glass)). example

[0071] Several aspects of the present technology are described in the following examples, numbered for convenience (1, 2, 3, etc.), which are provided as examples and are not intended to limit the subject technology.

[0064] 1. A method for manufacturing flexible electronics, comprising: applying a first protective material to a plurality of electronic features of an electronic assembly, the electronic assembly including a glass substrate, the plurality of electronic features being disposed on a first side of the glass substrate; exposing a second side of the glass substrate to a chemical that thins the glass substrate to a predetermined thickness, the second side being opposite the first side of the glass substrate; and applying a second protective material to a second side of the glass substrate.

[0065] 2. The method according to Example 1, Separating the plurality of electronic features into individual electronic components; and applying a third protective material around at least a portion of the individual electronic components.

[0066] 3. The method according to Example 2, the step of exposing the second side of the glass substrate to a chemical comprises immersing at least the second side of the glass substrate in a first chemical etching bath; The step of isolating the plurality of electronic features comprises: inscribing a cut track into the first side and / or the second side of the glass substrate using a laser, the cut track defining a boundary around the individual electronic components; and at least partially immersing the electronic assembly in a second chemical etching bath to separate the glass substrate along the cut track.

[0067] 4. The method according to Example 2, the step of exposing the second side of the glass substrate to a chemical comprises immersing at least the second side of the glass substrate in a first chemical etching bath; The step of isolating the plurality of electronic features comprises: forming a plurality of holes spaced apart from one another to define a cutting track in the glass substrate, the cutting track defining a boundary around an individual electronic component; and at least partially immersing the electronic assembly in a second chemical etching bath to separate the glass substrate along the cut track.

[0068] 5. The method of any of Examples 2-4, wherein the step of applying a third protective material around at least a portion of the individual electronic components comprises: applying a liquid polymer to an exterior surface of the singulated electronic component, the exterior surface including at least one side surface; soft-baking the electronic component to partially harden the liquid polymer; Removing the first protective material from the first side; and hard baking the electronic assembly to fully cure the liquid polymer on the second side and edges of the electronic component.

[0069] 6. The method of any one of the preceding examples, wherein the step of exposing the second side to a chemical comprises immersing the electronic assembly in a chemical etching bath. 7. The method of any one of the preceding examples, wherein the step of exposing the second side to a chemical includes removing material from the glass substrate to reduce defects from the second side of the glass substrate.

[0070] 8. The method of any one of the preceding examples, wherein the plurality of electronic features comprises a plurality of thin film transistors. 9. The method of any one of the preceding examples, wherein the plurality of electronic features constitute a fingerprint sensor.

[0071] 10. The method of any one of the preceding examples, wherein the step of exposing the second side of the glass substrate to a chemical that thins the glass substrate to a predetermined thickness includes chemically thinning the glass substrate to a thickness of at most 0.2 mm.

[0072] 11. The method of any one of the preceding examples, wherein the step of applying a second protective material to the second side of the glass substrate includes permanently bonding a film having high impact absorption properties to the second side of the glass substrate.

[0073] 12. A method for manufacturing flexible electronics, comprising: advancing the flexible glass substrate along a path of sequentially positioned fabrication modules to perform a series of manufacturing steps, the manufacturing steps including: disposing, via at least one electronics fabrication module, a plurality of discrete electronic features on an electronics side of the flexible glass substrate; applying a first protective material to the electronic device side of the flexible glass substrate via a covering module; and advancing the flexible glass substrate via the stamping module, the stamping track defining a boundary around the individual electronic components; at least partially immersing the flexible glass substrate in a chemical etching bath to separate the individual electronic components along the cut tracks to create a plurality of individual units; and applying a second protective coating to the plurality of individual units.

[0074] 13. The method of Example 12, wherein the step of advancing the flexible glass substrate along a path of sequentially positioned fabrication modules includes unrolling the flexible glass substrate from a roll as the flexible glass substrate advances along the path.

[0075] 14. The method of any one of Examples 12 and 13, wherein the roll is a first roll, and the method further comprises: The method further includes winding the flexible glass substrate onto a second roll positioned after at least a portion of the sequentially positioned fabrication modules as the first roll is unfolded to provide tension to the flexible glass substrate throughout the series of manufacturing steps.

[0076] 15. The method of any of Examples 12-14, wherein the step of inscribing the cut track includes laser inscribing the cut track to a predetermined inscribing depth, the predetermined inscribing depth being less than a thickness of the flexible glass substrate.

[0077] 16. The method according to any one of Examples 12 to 15, wherein the step of marking the cutting track comprises: imprinting a first cutting track on an electronics side of the flexible glass substrate; and imprinting a second cut track on a back side of the flexible glass substrate, the back side being opposite the electronics side, the second cut track being at least substantially aligned with the first cut track.

[0078] 17. The method of any of Examples 12-16, wherein the step of marking the cut track includes laser drilling a series of holes to define the cut track. 18. A method for improving the flexibility of an electronic component, comprising: controllably applying a chemical etchant to at least one surface of the electronic component to remove the microcracks and expose an interior portion of the electronic component, the interior portion being substantially free of defects; applying a protective film over the interior portion of the electronic component to protect the interior portion of the electronic component from the occurrence of defects; and photopatterning the protective film to form via holes to enable electrical connection to electrical contacts of electronic components aligned with the via holes.

[0079] 19. The method of Example 18, wherein the step of controllably applying a chemical etchant to at least one surface of the electronic component includes chemically etching at least a first surface and a second surface that meet at a common edge to round the common edge.

[0080] 20. The method of example 18 or 19, wherein the electronic component is a patterned thin film transistor array disposed on a flexible substrate and having a higher fracture stress than thin film transistors. conclusion

[0072] The above detailed description of the embodiments of the present technology is not intended to be exhaustive or to limit the present technology to the precise form disclosed above. While specific embodiments and examples of the present technology have been described above for illustrative purposes, those skilled in the art will recognize that various equivalent modifications are possible within the scope of the present technology. For example, while the steps are presented above in a given order, alternative embodiments may perform the steps in a different order. Furthermore, various embodiments described herein may be combined to provide further embodiments.

[0081]

[0073] From the above, it will be understood that although specific embodiments of the present technology have been described herein for illustrative purposes, well-known structures and functions may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the present technology. To the extent that any material incorporated herein by reference contradicts the present disclosure, the present disclosure shall control. Where the content permits, singular or plural terms may also include the plural or singular terms, respectively. Furthermore, unless the word "or" is expressly limited in relation to a list of two or more items to mean only a single item exclusively from the other items, the use of "or" in such a list shall be construed to include (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Furthermore, as used herein, the phrase "and / or," as in "A and / or B," refers to A only, B only, and both A and B. In addition, the terms "comprising," "including," "having," and "with" are used throughout to mean the inclusion of at least the recited features without the exclusion of any more of the same features and / or other features of additional types.

[0082]

[0074] From the above, it will also be appreciated that various modifications may be made without departing from the present disclosure or the present technology. For example, those skilled in the art will appreciate that various components of the present technology may be further divided into sub-methods, or that various systems and methods of the present technology may be combined and integrated. In addition, certain aspects of the present technology described in the context of certain embodiments may also be combined or deleted in other embodiments. Furthermore, although advantages associated with certain embodiments of the present technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the present technology. Thus, the present disclosure and related technology may encompass other embodiments not expressly shown or described herein.

Claims

1. A method for manufacturing flexible electronics, comprising: applying a first protective material to a plurality of electronic features of an electronic assembly, the electronic assembly including a glass substrate, the plurality of electronic features being disposed on a first side of the glass substrate; exposing a second side of the glass substrate to a chemical that thins the glass substrate to a predetermined thickness, the second side being opposite the first side of the glass substrate; applying a second protective material to the second side of the glass substrate; said method comprising: separating the plurality of electronic features into individual electronic components; and applying a third protective material around at least a portion of the individual electronic components, the applying the third protective material around at least a portion of the individual electronic components comprising: applying a liquid polymer to an exterior surface of the singulated electronic component, the exterior surface including at least one side surface; soft baking the electronic component to partially harden the liquid polymer; removing the first protective material from the first side; hard baking the electronic assembly to fully cure the liquid polymer on the second side and edges of the electronic component. A method comprising:

2. 2. The method of claim 1 , exposing the second side of the glass substrate to the chemical comprises immersing at least the second side of the glass substrate in a first chemical etching bath; The step of isolating the plurality of electronic features comprises: using a laser to inscribe a cut track into one or both of the first and second sides of the glass substrate, the cut track defining a boundary around the individual electronic components; at least partially immersing the electronic assembly in a second chemical etching bath to separate the glass substrate along the cutting track; Including, method.

3. 2. The method of claim 1 , exposing the second side of the glass substrate to the chemical comprises immersing at least the second side of the glass substrate in a first chemical etching bath; The step of isolating the plurality of electronic features comprises: forming a plurality of holes spaced apart from one another to define a cutting track in the glass substrate, the cutting track defining a boundary around the individual electronic components; at least partially immersing the electronic assembly in a second chemical etching bath to separate the glass substrate along the cutting track; Including, method.

4. 10. The method of claim 1, wherein exposing the second side to the chemical comprises immersing the electronic assembly in a chemical etching bath.

5. 10. The method of claim 1, wherein exposing the second side to the chemical comprises removing material from the glass substrate to reduce defects from the second side of the glass substrate.

6. The method of claim 1 , wherein the plurality of electronic features comprises a plurality of thin film transistors.

7. The method of claim 1 , wherein the plurality of electronic features includes a fingerprint sensor.

8. 2. The method of claim 1, wherein exposing the second side of the glass substrate to the chemical that thins the glass substrate to the predetermined thickness comprises chemically thinning the glass substrate to a thickness of at most 0.2 mm.

9. 2. The method of claim 1, wherein applying the second protective material to the second side of the glass substrate comprises permanently bonding a film having high impact absorption properties to the second side of the glass substrate.

Images