TWI669992B - Flexible electronic device and manufacturing method thereof - Google Patents

Abstract

A flexible electronic device includes a flexible substrate, a lead structure, and an elastic layer. The flexible substrate has a first surface and a second surface opposite to the first surface. The second surface of the flexible substrate includes a plurality of trenches. The lead structure is located on the first surface of the flexible substrate. The elastic layer is filled in the trench of the flexible substrate. The Young's modulus of the elastic layer is smaller than the Young's modulus of the flexible substrate. Another method for manufacturing a flexible electronic device is proposed.

Description

Flexible electronic device and manufacturing method thereof

The present invention relates to an electronic device and a method for manufacturing the same, and more particularly, to a flexible electronic device and a method for manufacturing the same.

With the rapid development of electronic technology, electronic products are constantly being introduced. In order to be applicable to different fields, electronic products have gradually gained attention due to their flexibility, thinness, and unrestricted appearance. In other words, electronic products are gradually required to have different appearances according to different application methods and application environments, and often need to be flexed or bent due to user needs.

However, when the flexible electronic product is in a flexed or bent state, the structure may be broken due to stress, and the internal circuit may be further broken. Therefore, how to make the flexible electronic products still have good yield and reliability has become an urgent problem to be solved.

The invention provides a flexible electronic device and a manufacturing method thereof, which have better yield or reliability.

The flexible electronic device of the present invention includes a flexible substrate, a lead structure, and an elastic layer. The flexible substrate has a first surface and a second surface opposite to the first surface, and the second surface of the flexible substrate includes a plurality of trenches. The lead structure is located on the first surface of the flexible substrate. The elastic layer is filled in the trench of the flexible substrate, and the Young's Modulus of the elastic layer is smaller than the Young's Modulus of the flexible substrate.

The method for manufacturing a flexible electronic device of the present invention includes the following steps. Carrier board provided. A release layer is formed on the carrier. A patterned elastic layer is formed on the release layer. The elastic layer has a plurality of elongated strips having a first extending direction and being parallel to each other. A flexible substrate is formed on the release layer. The flexible substrate covers the elastic layer, and the Young's modulus of the elastic layer is smaller than the Young's modulus of the flexible substrate. A patterned dielectric layer is formed on the flexible substrate, and the patterned dielectric layer has a groove in a first extending direction. A wire structure is formed on the flexible substrate in the groove and crosses both ends of the groove. The wire structure has a second extending direction, and the first extending direction is different from the second extending direction. Separate the carrier and the flexible substrate.

Based on the above, in the flexible electronic device of the present invention, the flexible substrate has a first surface and a second surface opposite to the first surface. The flexible substrate has trenches on the second surface to reduce the possibility of damage to the film layer or the component located on the first surface of the flexible substrate due to stress. In addition, the trench of the flexible substrate may be filled with an elastic layer to reduce the possibility of damage to the flexible substrate. In this way, the flexibility of the flexible electronic device can be improved, and the yield or reliability of the flexible electronic device can also be improved.

In order to make the above features and advantages of the present invention more comprehensible, embodiments are hereinafter described in detail with reference to the accompanying drawings. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of each element and the like is exaggerated for clarity. Throughout the description, the same reference numerals denote the same elements. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on another element" or "connected to another element" or "overlapping on another element", it may be directly on the other element It may be connected to another element, or an intermediate element may be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" may refer to a physical and / or electrical connection.

It should be understood that, although the terms "first," "second," "third," etc. may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, and / or sections, and / Or in part should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a "first element," "component," "region," "layer," or "portion" discussed below may be termed a second element, component, region, layer, or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particular embodiments only and is not limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms including "at least one" unless the content clearly indicates otherwise. "Or" means "and / or". As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It should also be understood that when used in this specification, the terms "including" and / or "including" specify the stated features, regions, wholes, steps, operations, presence of elements and / or components, but do not exclude one or more The presence or addition of other features, areas as a whole, steps, operations, elements, components, and / or combinations thereof.

In addition, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe the relationship of one element to another element, as shown. It should be understood that relative terms are intended to include different orientations of the device in addition to the orientation shown in the figures. For example, if the device in one of the figures is turned over, elements described as being on the "lower" side of other elements would then be oriented on "upper" sides of the other elements. Thus, the exemplary term "down" may include orientations of "down" and "up", depending on the particular orientation of the drawings. Similarly, if the device in one of the figures is turned over, elements described as "below" or "beneath" other elements would then be oriented "above" the other elements. Thus, the exemplary terms "below" or "below" may include orientations above and below.

As used herein, "about", "substantially", or "approximately" includes the stated value and the average value within an acceptable deviation range of a particular value determined by one of ordinary skill in the art, taking into account the measurements and A specific number of measurement-related errors (ie, limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the value, or within ± 30%, ± 20%, ± 10%, ± 5%.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted to have meanings consistent with their meanings in the context of the related art and the present invention, and will not be interpreted as idealized or excessive Formal meaning unless explicitly defined as such in this article.

An exemplary embodiment is described herein with reference to a cross-sectional view that is a schematic diagram of an idealized embodiment. Accordingly, variations in the shapes of the illustrations as a result, for example, of manufacturing techniques and / or tolerances, are to be expected. Therefore, the embodiments described herein should not be construed as limited to the particular shape of the area as shown herein, but include shape deviations caused by, for example, manufacturing. For example, a region shown or described as flat may generally have rough and / or non-linear characteristics. Furthermore, the acute angles shown may be round. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the claims.

The invention is explained more fully with reference to the drawings of this embodiment. However, the present invention may be embodied in various forms and should not be limited to the embodiments described herein. The thicknesses of the layers and regions in the drawings are enlarged or reduced for clarity. For example, in the cross-sectional views of the subsequent embodiments, in order to clearly show the mold layer or the carrier layer 10 or the flexible substrate 110, Component, and correspondingly reduces the thickness of the carrier board 10 or the flexible substrate 110, or enlarges the dielectric layer 130 or the active device 140 located thereon. In addition, the same or similar reference numbers indicate the same or similar elements, and the following paragraphs will not be repeated one by one.

1A to 1F are schematic partial cross-sectional views of a method for manufacturing a flexible electronic device according to a first embodiment of the present invention. FIG. 1G is a schematic top view of a portion of FIG. 1E. Specifically, FIG. 1G is a schematic top view of the region R1 in FIG. 1E and is clearly shown. In FIG. 1G, only the second dielectric layer 132 and the third dielectric layer 133 on the flexible substrate 110 are illustrated. , The fourth dielectric layer 134, the gate dielectric layer 142, the first insulating layer 20, the second insulating layer 40, the wire structure 160, and the projection position of a part of the elastic layer 120 that does not overlap with the third dielectric layer 133. FIG. 1H is a schematic top view of a portion of FIG. 1F. Specifically, FIG. 1H is a schematic top view of the region R2 in FIG. 1F. Fig. 1I is a schematic cross-sectional view taken along the line A-A 'in Fig. 1H. In addition, for simplicity and simplicity, only the flexible substrate 110, the lead structure 160, and the elastic layer 120 located in the trench 111 of the flexible substrate 110 are shown in FIGS. 1H and 1I.

First, referring to FIG. 1A, a carrier board 10 is provided. The material of the carrier plate 10 may be glass, quartz, wafer, organic polymer or metal. Other suitable materials can also be used as the carrier board 10 as long as the aforementioned materials can support the film layer or component formed thereon and can withstand subsequent processes, which are not limited in the present invention.

Next, a patterned photoresist layer 11 is formed on the substrate 10, and the patterned photoresist layer 11 exposes a part of the substrate 10. The material of the patterned photoresist layer 11 may include a silicone resin. Compared with carbon-based materials such as epoxy resin, phenol-formaldehyde resin or polyisoprene, which are based on carbon-based materials, they have silicon oxide. The resin patterned photoresist layer 11 has better thermal stability or chemical stability. In this embodiment, when the patterned photoresist layer 11 having a silicone resin is held at 400 ° C. for three hours, the weight ratio reduced due to high temperature may be less than 1.5%. In other words, by using the patterned photoresist layer 11 having a silicone resin, in this embodiment, a high-temperature process can still be performed in subsequent processes. Therefore, the manufacturing process of the flexible electronic device 70 is not too complicated, and the yield rate or the manufacturability of the product can be improved. Specifically, the silicone resin may include, for example, a polymer represented by the following Chemical Formula 1: [Chemical Formula 1] In Chemical Formula 1, x is 1 or 2, and R ₁ and R ₂ are each independently a linear alkyl group, a branched alkyl group, a cycloalkyl group, or a combination thereof with 1 to 40 carbon atoms.

Next, referring to FIG. 1B, a release layer 12 is formed on the carrier plate 10. The release layer 12 is, for example, composed of a material with weak adhesion, or the material constituting the release layer will decrease its adhesion after thermal process, ultraviolet (UV) process, or other similar processes. Releasability between the carrier board 10 and the film layer / component on the carrier board 10 can be improved in subsequent processes.

In this embodiment, the release layer 12 may conformally cover the patterned photoresist layer 11 on the carrier board 10. That is, the release layer 12 can completely cover the patterned photoresist layer 11, and can further cover a part of the carrier board 10 exposed by the patterned photoresist layer 11. The peel force between the release layer 12 and the patterned photoresist layer 11 may be smaller than the peel force between the carrier plate 10 and the patterned photoresist layer 11. In this way, in the subsequent process, when the carrier plate 10 is removed, the patterned photoresist layer 11 can still be attached to the carrier plate 10.

In other embodiments, the release layer 12 may directly cover the carrier plate 10. That is, there may be no other film layer between the release layer 12 and the carrier plate 10.

Next, referring to FIG. 1C, a patterned elastic layer 120 is formed on the release layer 12. In this embodiment, the method for forming the elastic layer 120 is, for example, forming an elastic material on the release layer 12 by a coating method and / or a Sol-Gel method, and may be based on the properties of the elastic material. A patterning and curing process is performed, such as an exposure, etching, photopolymerization or baking process, to cure a portion of the elastic material to form a patterned elastic layer 120.

The material of the elastic layer 120 may include a silicone resin. Compared with general rubber series rubber materials, acrylic series resins, vulcanized rubber or other hydrocarbon polymer materials with a chain structure as the base elastic layer 120, the silicone-based elastic layer 120 has Better thermal or chemical stability. In this embodiment, the Young's Modulus of the elastic layer 120 is less than or equal to 5 gigapascal (GPa). In some preferred embodiments, the Young's modulus of the elastic layer 120 may be less than or equal to 1.4 GPa. In addition, when the elastic layer 120 having the silicone resin is held at 400 ° C. for three hours, the weight ratio reduced due to high temperature may be less than 1.5%. In other words, by using the elastic layer 120 having a silicone resin, the present embodiment can still perform a high-temperature process in subsequent processes. Therefore, the manufacturing process of the flexible electronic device 70 is not too complicated, and the yield rate or the manufacturability of the product can also be improved.

In some embodiments, the material of the elastic layer 120 may be the same as that of the patterned photoresist layer 11, but the present invention is not limited thereto.

In this embodiment, the patterned elastic layer 120 is composed of a plurality of strip-shaped structures 121, and the strip-shaped structures 121 are parallel to each other and have a first extending direction 120a, as shown in FIG. , That is,-/ + Y direction.

In this embodiment, each stripe structure 121 of the elastic layer 120 is configured corresponding to the patterned photoresist layer 11. That is, the stripe structure 121 completely overlaps the corresponding patterned photoresist layer 11, and the projection area of the stripe structure 121 on the substrate 10 is completely covered by the patterned photoresist layer 11 on the substrate 10 Within the projection area.

Next, referring to FIG. 1D, after the patterned elastic layer 120 is formed, a flexible substrate 110 is formed on the patterned elastic layer 120 and the release layer 12. The material of the flexible substrate 110 is, for example, polyimide (PI) or other flexible material having thermal stability, but the present invention is not limited thereto. Taking the flexible substrate 110 formed of polyimide as an example, bisamine-type and difluorene-type reaction reagents can be coated on the carrier plate 10 to cover the elastic layer 120 and the release of the elastic layer 120. The layer 12 is then subjected to high-temperature aging dehydration (Imidization) to form a polyimide polymer to form a flexible substrate 110.

Next, referring to FIG. 1E, after the flexible substrate 110 is formed, a dielectric layer 130 is formed on the flexible substrate 110. The dielectric layer 130 may be an inorganic dielectric material covering the flexible substrate 110 on the flexible substrate 110 by a deposition process or other suitable processes. The inorganic dielectric material includes silicon oxide, silicon nitride, and oxynitride. Silicon, other suitable materials, or stacked layers of at least two of the above materials. In this embodiment, the dielectric layer 130 may include a first dielectric layer 131, a second dielectric layer 132, a third dielectric layer 133, and a fourth dielectric layer sequentially stacked from the first surface 110a of the flexible substrate 110. The dielectric layer 134 is not limited thereto.

Next, please continue to refer to FIG. 1E. After the dielectric layer 130 is formed, an active device 140 and a wire structure 160 for connecting the active device 140 are formed.

For example, a chemical vapor deposition method (Chemical Vapor Deposition; CVD) and a photolithography process can be used to form a patterned amorphous silicon on the flexible substrate 110. film. Next, the laser crystallization or Excimer Laser Annealing (ELA) process can be used to make the amorphous silicon film into a polycrystalline silicon film, and the laser can be used to scan the amorphous silicon film to make it Recrystallization to form a semiconductor layer 141 with polycrystalline silicon. This technique for forming polycrystalline silicon can be referred to as a low temperature poly-silicon (LTPS) process. In general, the entire process of the semiconductor layer 141 can be completed at a lower (eg, 400 degrees Celsius) process temperature by using a low-temperature polycrystalline silicon process. Therefore, the flexible substrate 110, The elastic layer 120 and / or the patterned photoresist layer 11 still have good stability or properties.

In some embodiments, an ion implantation (Ion Implantation) process (not shown) may be further performed, so that the semiconductor layer 141 has doped ions, and N-type or P-doped channel region.

After the semiconductor layer 141 is formed on the flexible substrate 110, a gate dielectric layer 142 is formed on the semiconductor layer 141. The gate dielectric layer 142 may be formed by a deposition process. The gate dielectric layer 142 conformally covers the semiconductor layer 141 and the dielectric layer 130 and directly contacts the semiconductor layer 141. In this embodiment, the gate dielectric layer 142 is, for example, a silicon oxide layer, a silicon nitride layer, or a silicon oxynitride (SiON) layer formed by a chemical vapor deposition method, but the present invention is not limited thereto.

Next, a gate G is formed on the gate dielectric layer 142, where the gate G is directly above the channel region of the semiconductor layer 141. The gate G can be formed by other suitable processes such as deposition and patterning processes. In this embodiment, the material or formation method of the gate G is not limited, but the gate G needs to have conductive properties capable of transmitting electronic signals.

Subsequently, an ion implantation process (not shown) is performed using the gate G as a mask to form source regions 141S and drain regions 141D separated from each other at opposite ends of the semiconductor layer 141, where the source regions The ion implantation process of 141S and the drain region 141D is, for example, ion implantation with appropriate energy, such as arsenic (As), phosphorus (P), boron (B) ions as doping ions to form P-type or N-type The source region 141S and the drain region 141D.

Next, after forming the source region 141S and the drain region 141D, a first insulating layer 20 is formed on the gate dielectric layer 142 and the gate G to cover a portion of the gate dielectric layer 142 and on the gate dielectric layer 142. Gate G. The first insulating layer 20 may be formed by a deposition process, a coating process, or other suitable processes, and may be a single-layer film or a laminate composed of a plurality of films. The layers of the first insulating layer 20 are not limited in this embodiment. Number, material, or formation method, except that the first insulating layer 20 needs to have electrical insulation properties.

In some embodiments, a conductive layer 30 and a second insulating layer 40 may be sequentially formed on the first insulating layer 20, and the second insulating layer 40 covers the conductive layer 30 and the first insulating layer not covered by the conductive layer 30. 20. In this embodiment, the conductive layer 30 can be used as a conductive wire, for example. In some embodiments, the conductive layer 30 can be used as a capacitor electrode to increase the storage capacitance. In other embodiments, the active element 140 may be a touch circuit of a touch element, and the conductive layer 30 may be a second gate G electrically coupled to the gate G. The conductive layer 30 can be set and / or adjusted according to the requirements of circuit design, which is not limited in the present invention.

Next, the dielectric layer 130, the gate dielectric layer 142, the first insulating layer 20 and the second insulating layer 40 on the flexible substrate 110 are patterned to form the recess 150. The groove 150 may be recessed from the insulating surface 41 of the second insulating layer 40 toward the flexible substrate 110, and the groove 150 penetrates the second insulating layer 40, the first insulating layer 20, the gate dielectric layer 142, and the fourth dielectric. The electrical layer 134 and the third dielectric layer 133 expose at least part of the second dielectric layer 132. That is, the bottom 151 of the groove 150 is located in the second dielectric layer 132. In other words, the dielectric layer 130 composed of the first dielectric layer 131, the second dielectric layer 132, the third dielectric layer 133, and the fourth dielectric layer 134 may be a patterned dielectric layer having a groove 150. 130.

In this embodiment, the groove 150 can be formed by, for example, a one-time or multiple lithography and etching process. In some embodiments, after the etching process, the minimum thickness 130b of the dielectric layer 130 in the recess 150 is 1000 angstroms (Å) to 2000 angstroms, but the present invention is not limited thereto. In the embodiment shown in FIG. 1E, the etching process is stopped at the second dielectric layer 132, but the present invention is not limited thereto. In other embodiments, the etching process may stop at any one of the first dielectric layer 131, the second dielectric layer 132, the third dielectric layer 133, or the fourth dielectric layer 134. Or, in one embodiment, the dielectric layer 130 that can be in the groove can be etched to the flexible substrate 110.

As shown in FIG. 1G, in this embodiment, the groove 150 may be strip-shaped, and the extending direction 150 a of the groove 150 is substantially parallel to the first extending direction 120 a of the strip-shaped structure 121 of the elastic layer 120.

Please continue to refer to FIG. 1E. After the grooves 150 are formed to pattern the dielectric layer 130, the gate dielectric layer 142, the first insulating layer 20, and / or A plurality of openings are formed in the second insulating layer 40. The first opening O1 penetrates the second insulating layer 40, the first insulating layer 20, and the gate dielectric layer 142 to expose a part of the drain region 141D. The second opening O2 penetrates the second insulating layer 40 and the first insulating layer 20 to expose a part of the gate electrode G. The third opening O3 penetrates the second insulating layer 40 to expose a part of the conductive layer 30. The fourth opening O4 penetrates the second insulating layer 40, the first insulating layer 20, and the gate dielectric layer 142 to expose a part of the source region 141S.

Then, a conductive material may be filled in the opening by a suitable process such as a deposition process and / or an electroplating process to form a plurality of conductive vias. The first via hole in the first opening O1 is electrically connected to the drain region 141D. The second via hole located in the second opening O2 is electrically connected to the gate electrode G. The third via hole in the third opening O3 is electrically connected to the conductive layer 30. The fourth via hole located in the fourth opening O4 is electrically connected to the source region 141S.

In this embodiment, the conductive substance filled in the opening may further cover the second insulating layer 40 and the groove 150. Subsequently, for example, a lithography and etching process may be used to pattern the conductive material on the second insulating layer 40 and the groove 150 to form a wire structure 160. The lead structure 160 has a second extending direction 160 a, and the second extending direction 160 a of the lead structure 160 is different from the first extending direction 120 a of the strip structure 121. The wire structure 160 extends from the active element 140 into the groove 150 along the second extending direction 160 a, and further crosses the groove 150 to the other end of the groove 150 relative to the active element 140, such as a peripheral region.

In the present embodiment, the wire crossing the groove 150 is a wire structure 160 electrically connected to the drain region 141D as an example, but the present invention is not limited thereto. In other embodiments, for example, according to a layout requirement, the wires crossing the groove 150 may be wires electrically connected to the conductive layer 30, the source region 141S, or the gate G.

In some embodiments, a third insulating layer 50, a first protective layer 61, electrodes 171, 172, and a second protective layer 62 may be further formed on the wire structure 160. The first protective layer 61 may be, for example, a flat layer, so that the electrodes 171 and 172 and the second protective layer 62 can be formed on a flat surface formed by the first protective layer 61. The third insulating layer 50, the first protective layer 61, and / or the second protective layer 62 may cover the wire structure 160, and the electrodes 171, 172 may be through vias penetrating the first protective layer 61 and / or the third insulating layer 50. To be electrically connected to the corresponding source / drain or wire structure 160.

Please refer to FIG. 1F. The carrier board 10 and the flexible substrate 110 are separated from each other to expose the flexible substrate 110 and the elastic layer 120 embedded in the flexible substrate 110. For example, external energy such as ultraviolet light, laser, visible light, or heat may be applied to the release layer 12 to remove the carrier plate 10. In other embodiments, other suitable removal processes can also be performed on the carrier board 10 by etching or mechanical stripping, which is not limited in the present invention.

In some embodiments, after the carrier board 10 is removed, a planarization process may be performed on the exposed flexible substrate 110 and the elastic layer 120 embedded in the flexible substrate 110 to make the flexible substrate 110 flexible. The flexible substrate 110 and the elastic layer 120 embedded in the flexible substrate 110 may be coplanar. After the above process, the fabrication of the flexible electronic device 100 of this embodiment can be substantially completed. The aforementioned flexible electronic device 100 includes a flexible substrate 110, an elastic layer 120, a dielectric layer 130, an active element 140, a wire structure 160, and a plurality of electrodes 171, 172.

Please refer to FIG. 1F, FIG. 1H and FIG. 1I at the same time, wherein FIG. 1H is a schematic top view of the region R2 in FIG. 1F, and FIG. 1I is a schematic cross-sectional view taken along the line A-A 'in FIG. 1H. The flexible substrate 110 has a first surface 110a and a second surface 110b opposite to the first surface 110a. The second surface 110b of the flexible substrate 110 includes a plurality of trenches 111 having a first extending direction 120a, and the trench depth 111a of the trench 111 is smaller than the substrate thickness 110c of the flexible substrate 110. The flexible substrate 110 includes a device region 112, a bendable region 113, and a peripheral region 114. The device region 112 and the peripheral region 114 are separated from each other and connected to opposite sides of the bendable region 113, respectively. In this way, when an end of the flexible electronic device 100 (ie, the component region 112 and / or the peripheral region 114) is subjected to an external force perpendicular to the direction of the flexible substrate 110 (such as the Z direction in FIG. 1F), The bendable region 113 of the flexible substrate 110 may be flexed or bent correspondingly, and the dielectric layer 130 and the wire structure 160 on the bendable region 113 may also have corresponding flexure or bend.

In this embodiment, the substrate thickness 110c of the flexible substrate 110 may be 3 micrometers (micrometers) to 20 micrometers, the trench depth 111a of each trench 111 may be 0.5 micrometers to 10 micrometers, and two adjacent trenches 111 The trench spacing 111c between them may be smaller than the trench depth 111a, and the trench width 111b of each trench 111 may be smaller than the trench depth 111a. For example, the substrate thickness 110c of the flexible substrate 110 may be 10 microns, the trench depth 111a of each trench 111 may be 7 microns, the trench spacing 111c between two adjacent trenches 111 may be 5 microns, and each trench The trench width 111b of 111 may be 2 micrometers, but the present invention is not limited thereto.

The elastic layer 120 is filled in the trench 111 of the flexible substrate 110, and the Young's modulus of the elastic layer 120 is smaller than the Young's modulus of the flexible substrate 110. In this embodiment, the material of the elastic layer 120 may include a silicone resin, and the Young's modulus of the elastic layer 120 is 5 GPa or less, but the present invention is not limited thereto.

In this embodiment, the flexible substrate 110 can improve the flexibility of the flexible substrate 110 by the configuration of the trench 111. Generally speaking, when a force is applied to a component, the stress at the discontinuity of the component's geometry will increase locally. This phenomenon is called stress concentration. It may be easier to damage the structure of the component at the stress concentration place. Therefore, by filling the elastic layer 120 in the trench 111 borrowed by the flexible substrate 110, the possibility of damage to the flexible substrate 110 due to stress concentration can be reduced. In addition, since the Young's modulus of the elastic layer 120 is smaller than the Young's modulus of the flexible substrate 110, the flexible substrate 110 can still have good flexibility. In addition, by providing the elastic layer 120 in the flexible substrate 110, the continuity of the structure can be improved to reduce the concentration of stress.

The dielectric layer 130 is located on the first surface 110 a of the flexible substrate 110, and the dielectric layer 130 may have a single-layer or multi-layer structure. The dielectric layer 130 includes a first portion 130a and a second portion 130c. The first portion 130 a corresponds to the bendable region 113 of the flexible substrate 110, and the second portion 130 c corresponds to the element region 112 of the flexible substrate 110. The first portion 130a has a groove 150 so that the minimum thickness 130b of the first portion 130a is smaller than the minimum thickness 130d of the second portion 130c.

The active device 140 is located on the dielectric layer 130 and is configured corresponding to the device region 112. In this embodiment, the active element 140 overlaps with the plurality of strip structures 121, but the present invention is not limited thereto. In other embodiments, the active element 140 may also be located between two adjacent strip structures 121.

The wire structure 160 is located on the dielectric layer 130, and the wire structure 160 may extend from the element region 112 to the bendable region 113 along the second extending direction 160 a and further extend to the peripheral region 114. In terms of structure, the second extending direction 160 a of the wire structure 160 is substantially a direction formed by the wire structure 160 connecting the opposite ends of the groove 150 respectively. As far as the circuit is concerned, the extending direction of the wire structure 160 may be a signal transmission direction, that is, the direction of current / electron flow transmitted by the electronic components at opposite ends of the groove 150 through the wire structure 160. That is, the second extending direction 160 a of the wire structure 160 is substantially different from the first extending direction 120 a of the trench 111.

In this embodiment, the first extending direction 120a of the trench 111 is, for example, the Y direction, and the second extending direction 160a of the wire structure 160 is, for example, the X direction, but the present invention is not limited thereto.

The electrodes 171 and 172 are located on the dielectric layer 130 and are disposed corresponding to the peripheral region 114 and / or the element region 112. For example, the electrodes 171 and 172 may include a first electrode 171 and a second electrode 172. The first electrode 171 is disposed in the device region 112 and is electrically connected to the active device 140. The second electrode 172 is disposed in the peripheral region 114 and is electrically connected to the active device 140 located in the element region 112 through a wire structure 160 disposed on the peripheral region 114, the bendable region 113 and the element region 112.

FIG. 2A is a schematic partial top view of a flexible electronic device according to a second embodiment of the present invention. Fig. 2B is a schematic cross-sectional view taken along the line B-B 'in Fig. 2A. Fig. 2C is a schematic cross-sectional view taken along the line C-C 'in Fig. 2A. Specifically, for clarity, FIG. 2A to FIG. 2C only show a part of the flexible substrate 110, the elastic layer 120 and the wire structure 260 located in the bendable region 113. Please refer to FIG. 2A to FIG. 2C and FIG. 1F to FIG. 1I. The flexible electronic device 200 of this embodiment is similar to the flexible electronic device 100 of the above embodiment, and the difference is that the lead structure 260 can have different configurations.

Specifically, in this embodiment, the wire structure 260 may include a plurality of strip-shaped wires 261 connected to the plurality of contacts 262 and 263. The strip-shaped wire 261 may have a plurality of discontinuous contacts 262, 263 having a geometric shape. The contacts 262 and 263 may include a plurality of turning points 262 and a plurality of intersection points 263. The turning points 262 and 362 and the intersection points 263 and 363 do not overlap the elastic layer 120 in the direction of the vertical substrate 110. Because in the flexible electronic device 200, the Young's modulus of the elastic layer 120 is smaller than the Young's modulus of the flexible substrate 110. That is, under the same force condition, the deformation amount generated by the flexible substrate 110 per unit volume may be smaller than the deformation amount generated by the elastic layer 120 per unit volume. Therefore, in the circuit design of the wire structure 260, the contacts 262, 263 can be arranged away from the elastic layer 120 to reduce the stress on the contacts 262, 263, and the wire structure 260 can be broken due to stress. It is possible to further improve the reliability of the flexible electronic device 200.

3A is a schematic partial top view of a flexible electronic device according to a third embodiment of the present invention. Fig. 3B is a schematic cross-sectional view taken along the line D-D 'in Fig. 3A. Fig. 3C is a schematic cross-sectional view taken along the line E-E 'in Fig. 3A. Specifically, for the sake of clarity, FIG. 3A to FIG. 3C only show a part of the flexible substrate 110, the elastic layer 120 and the wire structure 360 located in the bendable region 113. Please refer to FIG. 3A to FIG. 3C and FIG. 1F to FIG. 1I. The flexible electronic device 300 in this embodiment is similar to the flexible electronic device 100 in the above embodiment, and the difference is that the lead structure 360 can have different configurations.

Specifically, in this embodiment, the wire structure 360 may include a plurality of strip-shaped wires 361 connected to the plurality of contacts 362 and 363. The plurality of contacts 362 and 363 may include a plurality of turning points 362 and a plurality of intersection points 363. The turning points 362 and the intersection points 363 in the direction of the vertical substrate 110 do not overlap the elastic layer 120. In addition, the intersection points 363 may be arranged alternately between the adjacent elastic layers 120.

FIG. 4A is a schematic partial top view of a flexible electronic device according to a fourth embodiment of the present invention. Fig. 4B is a schematic cross-sectional view taken along the line F-F 'in Fig. 4A. Specifically, for the sake of clarity, FIG. 4A to FIG. 4B only show a part of the flexible substrate 110, the elastic layer 120 and the wire structure 460 located in the bendable region 113. Please refer to FIG. 4A to FIG. 4B and FIG. 1F to FIG. 1I. The flexible electronic device 400 of this embodiment is similar to the flexible electronic device 100 of the above embodiment, and the difference is that the lead structure 460 can have different configurations.

Specifically, in this embodiment, the conductive wire structure 160 may include a plurality of curved conductive wires 461. In the second extending direction 460a, the curved conductive wire 461 may have a plurality of saddle points 462 and a plurality of inflection points 463, and the saddle points 462 and the elastic layer 120 do not overlap in the direction of the vertical substrate 110.

5A to 5D are schematic partial cross-sectional views of a method for manufacturing a flexible electronic device according to a fifth embodiment of the present invention. In this embodiment, the manufacturing method of the flexible electronic device 500 is similar to the manufacturing methods of the flexible electronic devices 100, 200, 300, and 400 of the foregoing embodiment, and similar components are denoted by the same reference numerals and have similar Functions, materials, or formation methods, and descriptions are omitted. Specifically, the steps shown in FIGS. 5A to 5D may be schematic cross-sectional views of a method for manufacturing a flexible electronic device subsequent to the steps in FIG. 1F.

Please refer to FIG. 5A. In this embodiment, the flexible substrate 110 has a first surface 110a and a second surface 110b opposite to the first surface 110a. The second surface 110 b of the flexible substrate 110 includes a plurality of trenches 111, and the elastic layer 120 is filled in the trenches 111 of the flexible substrate 110. An electronic device 70 may be disposed on the first surface 110 a of the flexible substrate 110. The electronic device 70 may include, for example, the active device 140 and / or the lead structures 160, 260, 360, and 460 of the foregoing embodiments, and may further include a display medium, but the present invention is not limited thereto.

5B, a protective film 71 is formed on the first surface 110 a of the flexible substrate 110. The protective film 71 covers the electronic device 70 so that the electronic device 70 is not exposed.

5C, after the protective film 71 is formed, the elastic layer 120 on the second surface 110b of the flexible substrate 110 is removed (shown in FIG. 5B). Taking the elastic layer 120 formed by silicone resin as an example, it can be removed by a silicone solvent or hydrofluoric acid. However, the manner of removing the elastic layer 120 can be adjusted according to the material of the elastic layer 120, which is not limited in the present invention.

5D, after the elastic layer 120 is removed, the protective film 71 (shown in FIG. 5C) covering the electronic device 70 is removed. The removal method of the protective film 71 can be adjusted according to the material of the protective film 71, and is not limited in the present invention. For example, the protective film 71 may be removed by etching or peeling.

After the above process, the fabrication of the flexible electronic device 500 of this embodiment can be substantially completed. The above-mentioned flexible electronic device 500 includes a flexible substrate 110 and an electronic device 70. The flexible substrate 110 has a first surface 110a and a second surface 110b opposite to the first surface 110a. The second surface 110 b of the flexible substrate 110 includes a plurality of trenches 111. The electronic device 70 is disposed on the first surface 110 a of the flexible substrate 110.

In order to prove that the stress can be reduced by the wire structure of the present invention under the same degree of deflection or bending, the following test example is taken as an illustration. However, these test cases are not to be construed as limiting the scope of the present invention in any sense.

In the following comparative examples and test examples, the stress distribution diagram of a flexible substrate under the same degree of deflection or bending was calculated using simulation software. In the following comparative examples and test examples, the flexible substrate is a 10 μm thick polyurethane substrate as an example. The first dielectric layer, the second dielectric layer, and the second dielectric layer are sequentially stacked on the first surface of the flexible substrate. The dielectric layer, the third dielectric layer, and the fourth dielectric layer are respectively 500 Angstroms thick silicon nitride layer, 5000 Å thick silicon oxide layer, 1500 Å thick silicon nitride layer, and 3000 Å thick oxide. Take the silicon layer as an example.

FIG. 6A is a schematic partial cross-sectional view of a first comparative example according to the present invention. FIG. 6B is a stress distribution diagram of the first comparative example of FIG. 6A. Specifically, in the first comparative example of FIGS. 6A and 6B, the second surface 110'b of the flexible substrate 110 'has no trench.

In the first comparative example of FIGS. 6A and 6B, the maximum stress P1 is located on the third dielectric layer, and the corresponding stress value is about 596 MPa.

7A is a schematic partial cross-sectional view of a second comparative example according to the present invention. FIG. 7B is a stress distribution diagram of the second comparative example of FIG. 7A. Specifically, in the second comparative example of FIGS. 7A and 7B, the second surface of the flexible substrate 110 has a trench 111, and the trench depth 111a of the trench 111 (as shown in FIG. 1I) may be 7 microns, The trench distance 111c (shown in FIG. 1I) between two adjacent trenches 111 can be 5 microns, and the trench width 111b (shown in FIG. 1I) of each trench can be 2 microns. In addition, a hard material 120 'having a Young's modulus of 8 GPa was simulated in the formation channel.

In the second comparative example of FIGS. 7A and 7B, the maximum stress P2 is located on the third dielectric layer, and the corresponding stress value is about 891 MPa.

8A is a schematic partial cross-sectional view of a first test example according to the present invention. FIG. 8B is a stress distribution diagram of the first test example in FIG. 8A. Specifically, in the first test example of FIGS. 8A and 8B, the second surface of the flexible substrate 110 has a trench 111, and the trench depth 111 a of the trench 111 (as shown in FIG. 1I) may be 7 μm. The trench distance 111c (shown in FIG. 1I) between two adjacent trenches 111 can be 5 microns, and the trench width 111b (shown in FIG. 1I) of each trench can be 2 microns. In addition, no material is filled in the ditch.

In the first test example of FIGS. 8A and 8B, the maximum stress P3 is located in the trench 111 of the flexible substrate 110, that is, the geometric discontinuity of the flexible substrate 110, and the corresponding stress value is about It is 381 MPa. In addition, corresponding to the maximum stress point P1 of the first comparative example or the maximum stress point P2 of the second comparative example, the stress value of the local maximum stress P3 'on the third dielectric layer 133 in the first test example is approximately about 3 It is 229 MPa.

That is, compared to the flexible substrate 110 'having no trench in the first comparative example, or the hard material 120' being filled in the trench 111 of the flexible substrate 110 in the second comparative example. The flexible substrate 110 having the trench 111 and no material in the trench 111 can make the flexible substrate 110 have good flexibility, and can reduce the stress caused by the film layer or the component on the flexible substrate 110. Possible damage.

9A is a schematic partial cross-sectional view of a second test example according to the present invention. FIG. 9B is a stress distribution diagram of the second test example in FIG. 9A. Specifically, in the second test example of FIGS. 9A and 9B, the second surface 110b of the flexible substrate 110 has a trench 111, and the trench depth 111a of the trench 111 (as shown in FIG. 1I) may be 7 microns. The trench distance 111c (shown in FIG. 1I) between two adjacent trenches 111 can be 5 microns, and the trench width 111b (shown in FIG. 1I) of each trench 111 can be 2 microns. In addition, the elastic layer 120 having a Young's modulus of 1.4 GPa is filled in the formation channel 111 in a simulated manner.

In the second test example of FIGS. 9A and 9B, the maximum stress P4 is located on the third dielectric layer 133, and the corresponding stress value is about 461 MPa. In addition, corresponding to the maximum stress P3 of the flexible substrate 110 without any material in the trench 111 in the first test example, and the maximum local stress in the trench 111 of the flexible substrate 110 in the second test example. The maximum stress of P4 'is less than 10 MPa.

That is, compared to the flexible substrate 110 'having no trench in the first comparative example, or the hard material 120' being filled in the trench 111 of the flexible substrate 110 in the second comparative example. The elastic layer 120 is filled in the trench 111, and the Young's modulus of the elastic layer 120 is smaller than the Young's modulus of the flexible substrate 110, which can reduce the stress caused by the film layer or the component on the flexible substrate 110. Possible damage. In addition, the elastic layer 120 filled in the trench 111 can improve the continuity of the structure and reduce the possibility of damage to the flexible substrate 110 due to stress concentration.

In summary, in the flexible electronic device of the present invention, the flexible substrate has a first surface and a second surface opposite to the first surface. The flexible substrate has trenches on the second surface to reduce the possibility of damage to the film layer or the component located on the first surface of the flexible substrate due to stress. In addition, the trench of the flexible substrate may be filled with an elastic layer to reduce the possibility of damage to the flexible substrate. In this way, the flexibility of the flexible electronic device can be improved, and the yield or reliability of the flexible electronic device can also be improved. In addition, the material of the elastic layer may include a silicone resin, and the silicone resin has better thermal stability or chemical stability. Therefore, the elastic layer formed by the silicone resin does not complicate the manufacturing process of the flexible electronic device, and can also improve the yield or the manufacturability of the product.

Although the present invention has been disclosed as above with the examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

100, 200, 300, 400, 500‧‧‧ flexible electronic devices

10‧‧‧ Carrier Board

11‧‧‧ patterned photoresist layer

12‧‧‧ release layer

110, 110'‧‧‧ flexible substrate

110a‧‧‧first surface

110b, 110'b‧‧‧Second surface

110c‧‧‧ substrate thickness

111‧‧‧ditch

111a‧‧‧Ditch depth

111b‧‧‧ trench width

111c‧‧‧ditch spacing

112‧‧‧Element Area

113‧‧‧ bendable area

114‧‧‧Peripheral area

120‧‧‧ Elastic layer

121‧‧‧ strip structure

120a‧‧‧First extension direction

120'‧‧‧hard material

130‧‧‧ Dielectric layer

130a‧‧‧Part I

130b‧‧‧Minimum thickness

130c‧‧‧Part Two

130d‧‧‧Minimum thickness

131‧‧‧ first dielectric layer

132‧‧‧second dielectric layer

133‧‧‧Third dielectric layer

134‧‧‧ fourth dielectric layer

140‧‧‧active components

141‧‧‧Semiconductor layer

141S‧‧‧Source area

141D‧‧‧Drain

142‧‧‧Gate dielectric layer

G‧‧‧Gate

S‧‧‧Source

D‧‧‧ Drain

O1‧‧‧First opening

O2‧‧‧First opening

O3‧‧‧ third opening

O4‧‧‧ Fourth opening

20‧‧‧The first insulation layer

30‧‧‧ conductive layer

40‧‧‧Second insulation layer

41‧‧‧Insulated surface

150‧‧‧ groove

151‧‧‧ bottom

160, 260, 360, 460‧‧‧ wire structure

160a, 460‧‧‧ Second extension direction

261, 361‧‧‧ type conductor

262, 362‧‧‧ turning point

263, 363‧‧‧ intersection

461‧‧‧Curved wire

462‧‧‧ Saddle point

463‧‧‧recurve point

50‧‧‧ third insulating layer

61‧‧‧first protective layer

62‧‧‧Second protective layer

171‧‧‧first electrode

172‧‧‧Second electrode

70‧‧‧ electronic device

71‧‧‧ protective film

R1, R2‧‧‧ area

X, Y, Z‧‧‧ directions

P1, P2, P3, P4‧‧‧ maximum stress

P3 ', P4'‧‧‧ where the local stress is greatest

1A to 1F are schematic partial cross-sectional views of a method for manufacturing a flexible electronic device according to a first embodiment of the present invention. FIG. 1G is a schematic top view of a portion of FIG. 1E. FIG. 1H is a schematic top view of a portion of FIG. 1F. Fig. 1I is a schematic cross-sectional view taken along the line A-A 'in Fig. 1H. FIG. 2A is a schematic partial top view of a flexible electronic device according to a second embodiment of the present invention. Fig. 2B is a schematic cross-sectional view taken along the line B-B 'in Fig. 2A. Fig. 2C is a schematic cross-sectional view taken along the line C-C 'in Fig. 2A. 3A is a schematic partial top view of a flexible electronic device according to a third embodiment of the present invention. Fig. 3B is a schematic cross-sectional view taken along the line D-D 'in Fig. 3A. Fig. 3C is a schematic cross-sectional view taken along the line E-E 'in Fig. 3A. FIG. 4A is a schematic partial top view of a flexible electronic device according to a fourth embodiment of the present invention. Fig. 4B is a schematic cross-sectional view taken along the line F-F 'in Fig. 4A. 5A to 5D are schematic partial cross-sectional views of a method for manufacturing a flexible electronic device according to a fifth embodiment of the present invention. FIG. 6A is a schematic partial cross-sectional view of a first comparative example according to the present invention. FIG. 6B is a stress distribution diagram of the first comparative example of FIG. 6A. 7A is a schematic partial cross-sectional view of a second comparative example according to the present invention. FIG. 7B is a stress distribution diagram of the second comparative example of FIG. 7A. 8A is a schematic partial cross-sectional view of a first test example according to the present invention. FIG. 8B is a stress distribution diagram of the first test example in FIG. 8A. 9A is a schematic partial cross-sectional view of a second test example according to the present invention. FIG. 9B is a stress distribution diagram of the second test example in FIG. 9A.

Claims (12)

A flexible electronic device includes: a flexible substrate having a first surface and a second surface opposite to the first surface; and the second surface of the flexible substrate includes a plurality of trenches; A wire structure is located on the first surface of the flexible substrate, wherein the trenches have a first extension direction, the wire structure has a second extension direction, and the second extension direction is perpendicular to the first extension Direction; an elastic layer filled in the trenches of the flexible substrate, and the Young's modulus of the elastic layer is smaller than the Young's modulus of the flexible substrate, wherein the flexible substrate has a bendable A foldable area and a component area connected to the foldable area, the foldable area has the same first extension direction as the trenches, and the wire structure extends from the component area to the foldable area; A dielectric layer between the wire structure and the flexible substrate, the dielectric layer being a single-layer or multi-layer structure; and an active element located on the dielectric layer and electrically connected to the wire structure, and the The active element corresponds to the Element region is provided. The flexible electronic device according to item 1 of the scope of patent application, wherein a distance between adjacent trenches is greater than or equal to 5 microns, and a width of the trenches is greater than or equal to 2 microns. The flexible electronic device according to item 1 of the scope of patent application, wherein the depth of the trenches is smaller than the thickness of the flexible substrate. The flexible electronic device according to item 1 of the scope of patent application, wherein the wire structure includes a plurality of strip-shaped wires connected to a plurality of contacts, and the contacts are perpendicular to one of the flexible substrates. Does not overlap with this elastic layer. The flexible electronic device according to item 1 of the scope of patent application, wherein the trenches have a first extension direction, the wire structure includes a curved wire, and the curved wire has a plurality of along the second extension direction. Inflection points. The flexible electronic device according to item 1 of the scope of patent application, wherein the dielectric layer includes a first portion and a second portion, and the first portion corresponds to the bendable area of the flexible substrate. The two parts correspond to the element region of the flexible substrate, and the thickness of the first part is smaller than the thickness of the second part. The flexible electronic device according to item 1 of the scope of patent application, wherein the flexible substrate further has a peripheral region, wherein the bendable region is located between the element region and the peripheral region, and the wire structure is further from the The bendable region extends to the peripheral region, and the flexible electronic device further includes: an electrode on the dielectric layer and corresponding to the peripheral region of the flexible substrate, wherein the electrode and the active device The wire structures are electrically connected to each other. The flexible electronic device according to item 1 of the scope of patent application, wherein a material of the elastic layer includes a silicone resin, and a Young's modulus of the elastic layer is 5 GPa or less. A method for manufacturing a flexible electronic device includes: providing a carrier board; forming a release layer on the carrier board; forming an elastic layer having a pattern on the release layer, the elastic layer having a first layer A plurality of elongated strips extending parallel to each other; a flexible substrate is formed on the release layer, and the flexible substrate covers the elastic layer, and the Young's modulus of the elastic layer is smaller than the flexible layer Young's modulus of the flexible substrate; forming a patterned dielectric layer on the flexible substrate, the patterned dielectric layer having a groove in the first extending direction; forming a wire on the flexible substrate The wire structure has a second extension direction, and the first extension direction is different from the second extension direction; and the carrier board and the flexible substrate are separated. . The method for manufacturing a flexible electronic device according to item 9 of the scope of the patent application, wherein a material of the elastic layer includes a silicone resin, and a Young's modulus of the elastic layer is less than 5 GPa. The method for manufacturing a flexible electronic device according to item 9 of the scope of patent application, further comprising: forming a patterned photoresist layer on the carrier board before forming the release layer, wherein the release layers are The pattern covers the patterned photoresist layer; the elastic layer formed on the release layer corresponds to the patterned photoresist layer. The method for manufacturing a flexible electronic device according to item 9 of the scope of patent application, further comprising: removing the elastic layer after separating the carrier board from the flexible substrate.