Energy-saving window coating capable of being penetrated by wireless communication signals and manufacturing method of energy-saving window coating

Abstract

Energy efficient signaling transparent window assemblies and methods of making the same are described herein. The components retain the infrared blocking characteristic while allowing signal penetration, and remain substantially transparent in the visible spectrum, and any feature is difficult to detect by naked eyes. This performance is achieved by isolating the stack with conductive performance into discrete small cells by a gap pattern, the subsequent result being that the gap is covered by a secondary stack. The line width of the secondary stack is at least 0.4 microns larger than the gap between the small cell main stacks. The main stack increases from zero to full thickness near the gap with a sidewall transition length exceeding 0.2 microns. The manufacturing process includes lithography for patterning, PVD coating, and post-cleaning and high temperature processing. In some embodiments, a transparent organic thin layer is disposed between the secondary stack and the primary stack or the substrate. In addition, a thick dry film photoresist method in a special photoetching process can remarkably reduce the manufacturing cost.

Description

[0001] Cross-references to related applications

[0002] This application claims U.S. Provisional Patent Application No. 63 / 579,237 (Case No. LFINP008P) filed by Guowen Ding under 35 USC § 119(e), entitled “Energy-efficient window coating capable of transmitting wireless communication signals and method of manufacturing the same,” filed on 2023-08-28; and U.S. Provisional Patent Application No. 63 / 624,364 (Case No. LFINP008P2) filed by Guowen Ding, entitled “Energy-efficient window coating capable of transmitting wireless communication signals and method of manufacturing the same,” filed on 2024-01-24, both of which are incorporated herein by reference in their entirety for all purposes. Background Technology

[0003] Windows are often the least energy-efficient component of a building. For example, radiative heat transfer accounts for about 60% of the total energy loss through a standard window. Energy-efficient windows use special coatings to reduce this heat transfer, such as by blocking infrared (IR) radiation with wavelengths between 5 and 50 micrometers. However, energy-efficient windows also tend to block wireless communication signals with wavelengths longer than 50 micrometers, even longer than 0.5 millimeters. This signal blocking negatively impacts mobile network reception, Wi-Fi access, and other applications. Traditional methods use external antennas to rebroadcast signals inside the building. However, such systems are complex, expensive, and provide limited coverage within the building. Furthermore, covering all areas inside a building with such a system can be difficult. Summary of the Invention

[0004] This paper presents novel signal-transmissible energy-efficient window assemblies and their manufacturing method. These window assemblies are specifically configured to allow selective penetration by millimeter waves, which represent the current and future wireless signal spectrum. This signal penetration is provided while retaining infrared blocking properties. Furthermore, these window assemblies remain substantially transparent within the visible spectrum, with no specific features detectable to the naked eye. This unique property is achieved by patterning conductive layers to ensure that the edges of the conductive layers are protected during most manufacturing steps and processes. Thus, the conductive layers are encapsulated and isolated from the environment while maintaining separation between the individual discrete structures within these layers. For example, blocking layers and / or dielectric layers can extend to cover the edges of the conductive layers. Patterning is achieved by forming spacers on a substrate and depositing stacks on these photoresist structures. Subsequently, the spacers can be removed.

[0005] Clause 1. An energy-efficient and signal-transparent window assembly, comprising: a window substrate; a first dielectric layer disposed on the window substrate; a conductive layer disposed on the first dielectric layer such that the first dielectric layer is located between the conductive layer and the window substrate, wherein the conductive layer comprises a plurality of mutually separated structures and is separated by gaps; and a second dielectric layer disposed on the conductive layer such that the conductive layer is located between the second dielectric layer and the first dielectric layer, wherein: the first dielectric layer, the conductive layer, and the second dielectric layer form a plurality of primary stacks and a plurality of secondary stacks on at least a portion of the window substrate, the plurality of secondary stacks forming a pattern, defined as a pattern line, partially on the window substrate and partially on the top surface of the plurality of primary stacks, and the width of each pattern line is greater than the gap separating the plurality of separate structures by at least 0.4 micrometers.

[0006] The first dielectric layer may include one or more dielectric layers, for example, one of which is a barrier layer located between a pair of dielectric layers. Therefore, the first dielectric layer may also be referred to as a first dielectric layer or a first dielectric layer assembly. The conductive layer is formed by a plurality of separated structures spaced apart by gaps. The signal-penetrating energy-saving window assembly also includes a second dielectric layer disposed on the conductive layer, such that the conductive layer is located between the first and second dielectric layers. The second dielectric layer may include one or more dielectric layers, for example, one of which is a barrier layer located between a pair of dielectric layers. Therefore, the second dielectric layer may also be referred to as a second dielectric layer or a second dielectric layer assembly. Each of the above layers may include multiple layers of different materials. The first dielectric layer, the conductive layer, and the second dielectric layer form a main stack, and a secondary stack is on at least a portion of the window substrate and on a portion of the main stack.

[0007] Clause 2. A signal-permeable energy-efficient window assembly as described in Clause 1, wherein the second dielectric layer comprises a blocking material comprising one of nickel or titanium.

[0008] Clause 3. A signal-transmissible energy-efficient window assembly as described in Clause 1, wherein each of a plurality of secondary stacks is in direct contact with the window substrate.

[0009] Clause 4. A signal-permeable energy-efficient window assembly as described in Clause 1, wherein a plurality of secondary stacks are connected to the window substrate by a connecting layer comprising (a) a continuous material layer or (b) a combination of a discontinuous material layer and an air cavity.

[0010] Clause 5. A signal-permeable energy-efficient window assembly as described in Clause 4, wherein the connecting layer contains carbon with an atomic concentration greater than 10%.

[0011] Clause 6. Energy-efficient window assembly with signal permeability as described in Clause 4, wherein the thickness of the connecting layer is 1-1000 nanometers.

[0012] Clause 7. The signal-transmissible energy-saving window assembly according to Clause 4, wherein the connecting layer is formed by a solution treatment containing at least one functional group selected from the group consisting of C=O, –OH, COO, and C–O–C.

[0013] Clause 8. A signal-transmissible energy-efficient window assembly as described in Clause 1, wherein the width of each of the plurality of secondary stacks is between 1 micrometer and 100 micrometers.

[0014] Clause 9. The signal-transmissible energy-efficient window assembly as described in Clause 1 further includes a protective layer disposed on a plurality of primary stacks and a plurality of secondary stacks.

[0015] Clause 10. A signal-permeable energy-efficient window assembly as described in Clause 9, wherein the protective layer comprises a transparent material having a refractive index between 1.6 and 1.9 at a wavelength of 550 nanometers.

[0016] Clause 11. The signal-transmissible energy-saving window assembly according to Clause 1 further includes an additional window substrate, wherein a first dielectric layer, a conductive layer and a second dielectric layer are located between the window substrate and the additional window substrate.

[0017] Clause 12. The signal-permeable energy-saving window assembly according to Clause 1, wherein each of the plurality of main stacks includes two adjacent sidewalls formed by a second dielectric layer extending downward to the substrate and completely encapsulating the conductive layer between the substrate and the second dielectric layer.

[0018] Clause 13. A signal-transmissible energy-efficient window assembly as described in Clause 1, wherein the width of the secondary stack is between 2 and 10 micrometers.

[0019] Clause 14. A signal-transmissible energy-efficient window assembly, comprising:

[0020] A window base plate;

[0021] A first dielectric layer disposed on a window substrate;

[0022] A conductive layer disposed on a first dielectric layer, such that the first dielectric layer is located between the conductive layer and the window substrate, wherein the conductive layer is formed by a plurality of separated structures spaced apart by gaps;

[0023] A second dielectric layer is disposed on the conductive layer, such that the conductive layer is located between the second dielectric layer and the first dielectric layer, wherein: the first dielectric layer, the conductive layer, and the second dielectric layer form multiple master stacks, each master stack including two sidewalls separated from each other by gaps forming a pattern defined by pattern lines, and the width of each pattern line is greater than the gap separating the multiple discrete structures by 0.4 to 6 micrometers.

[0024] Clause 15. The signal-transmissible energy-efficient window assembly as described in Clause 14 further includes a protective layer disposed on a plurality of main stacks, the protective layer comprising a transparent material with a conductivity of less than 1 S / M.

[0025] Clause 16. The signal-transmissible energy-efficient window assembly as described in Clause 14 further includes an additional window substrate, wherein a plurality of main stacks are located between the window substrate and the additional window substrate.

[0026] Clause 17. A signal-transmissible energy-efficient window assembly, comprising:

[0027] A window base plate;

[0028] A non-conductive spacer forms a pattern on the window substrate, contacts a portion of the window substrate, and blocks that portion of the window substrate.

[0029] A first dielectric layer contacts the window substrate and non-conductive spacers;

[0030] A conductive layer is disposed on the first dielectric layer, such that the first dielectric layer is located between the conductive layer and the window substrate or non-conductive spacer;

[0031] A second dielectric layer is disposed on the conductive layer, such that the conductive layer is located between the second dielectric layer and the first dielectric layer;

[0032] Non-conductive structures located between conductive layers form multiple main stacks and multiple secondary stacks, wherein: a first dielectric layer, a conductive layer, and a second dielectric layer form multiple main stacks; multiple secondary stacks are on at least a portion of the window substrate, and the multiple secondary stacks form a pattern defining spacer pattern lines, partly on the window substrate and partly on the top surface of the multiple main stacks, the spacer pattern lines including a top surface and a side surface, the stacks being broken on the top surface or side surface of the spacer pattern lines, thereby physically isolating the stacks and making the conductive layers discontinuous along the spacer pattern lines.

[0033] Clause 18. The signal-transmissible energy-efficient window assembly as described in Clause 17, wherein the spacer pattern lines are formed using a photolithography process with a photoresist thickness greater than 1.5 micrometers.

[0034] Clause 19. The signal-transmissible energy-saving window assembly according to Clause 17 further comprises forming a protective layer disposed on a stack, said protective layer comprising a transparent material with a conductivity of less than 1 S / M.

[0035] Clause 20. A signal-transmissible energy-efficient window assembly as described in Clause 17, wherein a stack is bonded to an additional window substrate such that the stack and a non-conductive spacer are located between the window substrate and the additional window substrate.

[0036] These and other embodiments will be further described below with reference to the accompanying drawings. Attached Figure Description

[0037] Figure 1A is a schematic cross-sectional view of a signal-transmissible energy-saving window assembly, which, according to some embodiments, includes a conductive layer formed by multiple discrete structures.

[0038] Figure 1B is another schematic cross-sectional view of a signal-transmissible energy-saving window assembly, which, according to some embodiments, includes a transparent organic layer for use in the conductive layer formed by multiple discrete structures in the structure of Figure 1A.

[0039] Figure 1C is another schematic cross-sectional view of a signal-transmissible energy-saving window assembly, which, according to some embodiments, includes a conductive layer formed by multiple discrete structures.

[0040] Figure 2 This is a schematic enlarged view of a portion of the signal-transmissible energy-saving window assembly in Figures 1A-1C, according to some embodiments.

[0041] Figure 3A is a schematic cross-sectional view of another embodiment of an energy-saving transparent window assembly, including a protective layer, an adhesive layer, and another glass substrate.

[0042] Figure 3B is a schematic cross-sectional view of another embodiment of the energy-saving transparent window assembly, including a protective layer, an adhesive layer and another glass substrate.

[0043] Figure 3C is a schematic cross-sectional view of a signal-transmissible energy-saving window assembly having multiple low-emissivity stacks stacked on top of each other, according to some embodiments.

[0044] Figure 4A is a perspective view of a signal-transmissible energy-saving window assembly, which, according to some embodiments, shows a pattern formed by gaps between multiple separate structures.

[0045] Figure 4B is a scanning electron microscope (SEM) image of the patterned lines, showing the roughness of the patterned line edges.

[0046] Figure 5 is a flowchart of a method for forming a signal-transmissible energy-efficient window assembly, according to some embodiments.

[0047] Figures 6A-6D are schematic cross-sectional views of various stages of a method for forming a signal-transmissible energy-efficient window assembly according to some embodiments.

[0048] Figure 6E is a schematic cross-sectional view of the spacer according to some embodiments, showing the bottom etched structure.

[0049] Figures 7A-7D are schematic diagrams of additional stages in a method for forming a signal-transmissible energy-saving window assembly according to some embodiments.

[0050] Figures 8A-8I are schematic cross-sectional views of various stages of a dry photoresist method for forming a signal-transmissible energy-efficient window assembly according to some embodiments.

[0051] Figure 9A is a schematic diagram of an energy-saving coating structure, which, according to some embodiments, includes patterned lines attached to a substrate.

[0052] Figures 9B and 9C are schematic diagrams of the energy-saving coating structure, which, according to some embodiments, includes patterned lines attached to the substrate during post-processing.

[0053] Figure 10 illustrates the test results for the energy-efficient window assembly that allows signal penetration. Detailed Implementation

[0054] In the following description, numerous specific details are outlined to provide a thorough understanding of the proposed concepts. The proposed concepts can also be practiced without some or all of these specific details. In other instances, well-known process operations are not described in detail to avoid unnecessarily obscuring the described concepts. While some concepts will be described in conjunction with specific embodiments, it should be understood that these embodiments are not intended to limit the scope.

[0055] introduce

[0056] Energy-efficient windows are becoming increasingly popular in commercial and residential buildings, as well as other applications. Energy-efficient windows may include one or more conductive layers (such as silver-based layers) responsible for blocking infrared radiation, as well as various dielectric and blocking layers. These conductive layers may also be referred to as metallic layers or transparent conductive oxide (TCO) layers. However, energy-efficient windows, or more specifically, conductive layers, often cause signal attenuation, interfering with wireless signal transmissions (such as cell phone signals). As mentioned above, traditional solutions involve installing distributed antenna systems (DAS) within the building to enhance signal propagation. However, this approach requires specialized equipment, additional power consumption, and additional cost.

[0057] It has been found that separating a conductive layer into multiple discrete structures helps reduce signal attenuation. It should be noted that the wavelength of electromagnetic waves that can pass through such a patterned conductive layer depends on the opening size between the discrete structures. More specifically, the wavelength depends on the opening width between adjacent pairs of discrete structures; for example, the maximum opening width is less than the wavelength. For example, a continuous conductive layer can be formed on a substrate and then patterned, for example, by removing a small portion of the conductive layer and forming an opening from top to bottom / through (e.g., extending into the substrate). However, the patterning process and the subsequent exposure of the conductive layer edges (within the opening) can lead to various durability and aesthetic problems (e.g., unsightly visible line marks). Therefore, patterning methods have not been widely adopted. Furthermore, patterning becomes particularly challenging when dealing with fifth-generation (5G) networks using wavelengths greater than 1 mm. This wavelength requires openings less than 0.2 mm wide to achieve sufficient signal transmission. Future generations of networks are expected to use shorter wavelengths, requiring even smaller openings, which may pose a challenge for conventional laser scribing techniques.

[0058] This article describes various embodiments of signal-transmissive energy-efficient window assemblies and methods of manufacturing them. These assemblies are transparent in the visible light region, allowing electromagnetic waves of specific wavelengths (e.g., carrying wireless communication signals) to pass through, and are capable of blocking infrared radiation. For example, transparency in the visible light region (e.g., wavelengths 380–780 nm) can range from 10% to 100% transmittance. In the same or other embodiments, the signal-transmissive energy-efficient window assembly allows electromagnetic waves with a wavelength of 12.5 cm (corresponding to a frequency of 2.4 GHz) to pass through, with an additional loss of only about 5 dB compared to an uncoated window substrate. Furthermore, in some embodiments, the infrared blocking / emissivity remains less than 0.15, a value corresponding to more than 85% of the spectrum with wavelengths between 5 μm and 50 μm being blocked by the signal-transmissive energy-efficient window assembly. In comparison, conventional low-emissivity (low-E) windows (e.g., samples from AGC Glass North America in Alphaletta, Georgia) have been found to have a signal loss of approximately 30 dB (measured from 1 GHz to 5 GHz).

[0059] Furthermore, the signal-penetrating energy-efficient window assembly described in this article has no unsightly visible marks and is aesthetically pleasing, unlike low-E windows with laser patterns. For example, when the window assembly is inspected at a 90° angle to the surface of the window assembly under uniform backlighting (simulated sunlight) (e.g., light intensity of 10,000 lux or above), no visible marks can be observed (i.e., they are not visible to the naked eye).

[0060] The signal-permeable energy-saving window assembly described in this article also exhibits long-term durability. For example, accelerated durability testing, which involves immersing the sample in boiling water for one hour, revealed no visible defects according to the aforementioned inspection standards (such as "visual" inspection and digital photography). Furthermore, no additional defects resulting from the accelerated durability test were detected under a microscope. Another method for accelerated durability testing involves baking the sample in an oven at 650°C for 8 minutes. Again, microscopic examination revealed no additional defects.

[0061] Finally, the energy-efficient window components that allow signal penetration enable the wireless propagation of 5G signals (6 GHz frequency, corresponding to a 50 mm wavelength) and other similar signals (such as those using future technologies with higher frequencies and smaller wavelengths). In some cases, the opening width is even less than 0.1 mm, far smaller than the wavelength of these communication technologies.

[0062] Examples of stacking gaps and overlaps in energy-efficient window assemblies that allow signal penetration

[0063] Figure 1A An example of a signal-transmissible energy-efficient window assembly 100 is shown. This assembly comprises a window substrate 110 and a stack assembly 170, which consists of different stacks, such as a primary stack 171 and a secondary stack 172. Each stack may contain a conductive layer, as will be discussed later. Figure 2 Please provide a detailed explanation.

[0064] refer to Figure 1A In some examples, stack assembly 170 includes main stack groups 171, for example, formed on window substrate 110. These main stacks 171 are separated by stack gaps 175, such as... Figure 1A As shown. These stack gaps 175 form breaks in the conductive layer of the main stack 171. Segmented conductive layer ( Figure 1A (And indicated by dashed lines in other figures below) may be referred to as separation structure 132. These separation structures 132 allow wireless transmission through the signal-penetrating energy-efficient window assembly 100. Stack gap 175 is defined as the width of the gap between two adjacent main layers, with the top typically representing the first dielectric layer 120 or the top layer 150, the material of stack 171, and structural layers 120, 130, 140, 150, as... Figure 2 As shown.

[0065] refer to Figure 1A In some examples, stack component 170 also includes a secondary stack 172, which is formed on a photoresist (e.g., see below). Figures 7A-7D(Further explanation). In the signal-penetrable energy-efficient window assembly 100 (after photoresist removal), these secondary stacks 172 can completely or at least partially fill the stack gaps between the primary stacks 171. It should be noted that even if the secondary stacks 172 completely or at least partially fill the stack gaps 175, the conductive layer of the primary stack 171 remains disconnected. In some cases, some photoresist may not be completely removed, leaving some residue 194. This residue may form gaps 190 between the primary stack 171 and the secondary stacks 172, or between the window substrate 110 and the secondary stacks 172, for example, as shown below. Figure 1A The schematic diagram is shown. Specifically, residues 194 and / or voids 190 are formed after or during photoresist removal. In some cases, the height of these residues 194 is less than 500 nanometers on average, or less than 100 nanometers, more specifically, less than 50 nanometers on average, and may even be directly in contact with the window substrate and the top of the main stack.

[0066] refer to Figure 1A In some examples, the dimensions (e.g., width in the X direction) and position (e.g., alignment along the X direction relative to the stack gap 175) of the secondary stack 172 are such that a portion of the secondary stack 172 covers the stack gap 175 (overlapping / directly interfaceing with the window substrate 110), while other portions extend to cover the main stack 171 or, more specifically, on the surface of the main stack 171 facing the window substrate 110. In other words, at least a portion of the main stack 171 may extend / stack between the window substrate 110 and the secondary stack, as... Figure 1A The diagram shows that, specifically, the secondary stack 172 is wider than the corresponding stack gap 175. In some examples, the overlap width on both sides of the gap 175 is ( Figure 1A The "overlap width" in the text is at least 0.2 micrometers, at least 2 micrometers, at least 3 micrometers, or even 5 micrometers. For example, the overlap width ( Figure 1A The "overlap width" can be 0.2-3 micrometers, more specifically 0.2-2 micrometers. This overlap ensures the overall performance and functionality of the window assembly. This "overlap width" is directly related to the initial amount of photoresist reduction. Specifically, the larger the area of ​​the bottom etched structure, the less likely or less conductive coating material will be deposited beneath the bottom etched structure layer (e.g., along the sidewalls), as follows: Figure 6EOn the other hand, the conductive layer can be protected by a second dielectric layer coating on the sidewalls, for example, to prevent coating durability. Generally, the thinner the photoresist, the smaller the amount of cutting required. For example, the photoresist thickness can be at least 0.2 micrometers, or more specifically, at least 0.5 micrometers thick. Therefore, the "overlap width" can be at least 0.2 micrometers, or even at least 0.5 micrometers. In some examples, the ratio of photoresist thickness to "overlap width" thickness is at least 0.75, at least 1, or even at least 1.5. On the other hand, an excessively wide overlap width may reduce the energy efficiency of the window due to partial infrared radiation leakage. Therefore, in some examples, the overlap width is less than 5 micrometers, more specifically, less than 3 micrometers, or even less than 2 micrometers.

[0067] In some cases, the width of the secondary stack is 172 ( Figure 1A The “secondary stack width” is less than 100 micrometers, less than 20 micrometers, or even less than 10 micrometers, such as 1-100 micrometers, more specifically 2-10 micrometers. In the same or other examples, the width of the stack gap 175 ( Figure 1A The “gap width (175)” is 0.2-20 micrometers, more specifically 0.5-5 micrometers. It should be noted that the sidewalls of the main stack 171 are almost parallel to the window substrate 110, with only a few degrees of tilt. Therefore, for clarity, the gap width is defined as the minimum distance between two adjacent sidewalls (e.g., ...). Figure 1A At the interface between the middle sidewall and the window substrate 110.

[0068] refer to Figure 1B In some examples, a transparent organic layer 196 is located between the secondary stack 172 and the window substrate 110, and / or between the secondary stack 172 and the main stack 171. The transparent organic layer 196 can be a continuous film or a discontinuous film (e.g., with air gaps 190). The thickness of the transparent organic layer 196 may be 1-1000 nanometers, more specifically 2-100 nanometers. The thickness of the air gaps 190 is the same as or less than that of the organic layer 196. The transparent organic layer 196 may contain at least 10% atomic content of carbon (elemental content), more specifically, at least 20% atomic content. The transparent organic layer 196 may be formed from photoresist residue, and in some cases, partially formed from cleaning solvents and / or a PVD coating. In some examples, the transparent organic layer 196 acts as an adhesive medium, ensuring that the secondary stack 172 is firmly bonded to other components, such as the window substrate 110 and / or the main stack 171. The transparency of the transparent organic layer 196 ensures that no pattern is visible even under direct sunlight. The extinction coefficient k of this wiring is less than 0.1 at a wavelength of 550 nanometers.

[0069] In some examples, the area occupied by the transparent organic layer 196 is smaller than that of the secondary stack 172. Therefore, the transparent organic layer 196 is covered by the secondary stack 172 and does not protrude beyond the boundary of the secondary stack 172.

[0070] refer to Figure 1C In some examples, the stack assembly 170 contains only the primary stack 171, without secondary stacks 172. These pattern lines (formed by stack gaps 175) remain invisible to the human eye. There are also no diffraction pattern lines under strong light, demonstrating excellent aesthetic performance. The film exhibits excellent mechanical durability, passing an alcohol wipe test, meaning that the pattern lines remain undamaged after wiping with an alcohol cloth.

[0071] To achieve superior optical aesthetics and durability, the overlap width or sidewall length is 0.2–5 micrometers, or 0.2–3 micrometers, more specifically 0.2–2 micrometers. (Reference) Figure 1C The example of "secondary stack width" in the text, where the overlap width or sidewall length is defined as the thickness of the stack 171 coating begins to thin ( Figure 1C and Figure 2 The coating thickness of the "A" in the stack 171 reaches zero ( Figure 1C and Figure 2 The region of point "B" in the coating film. The start and end points on the coating film can be determined by assuming a straight line intersecting the top and bottom extension lines of the coating film, and this straight line is chosen to be a sloping line tangent to the point in the coating thickness curve at the midpoint of the main stack thickness.

[0072] Stack example in an energy-efficient window assembly with signal permeability

[0073] refer to Figure 2 In some examples, each stack in the stack assembly 170 consists of a conductive layer 130, a barrier layer 140, and a second dielectric layer 150. The first dielectric layer 120, conductive layer 130, barrier layer 140, and second dielectric layer 150 can form the stack assembly 170 or serve as a reference low-emissivity (Low-E) coating. In some cases, the conductive layer 130 may be composed of silver or a silver alloy. In these examples, the first dielectric layer 120 may form a barrier layer similar to the 140th layer adjacent to the conductive layer 130 (e.g., directly bonded to the conductive layer 130) to enhance the durability of the conductive layer 130 or, more generally, the energy-saving signal window assembly 100. Sometimes, the second dielectric layer may consist of multiple layers, such as the barrier layer 140 and the second dielectric layer 150. In other examples, the conductive layer 130 can be formed using a highly durable material such as gold or transparent conductive oxide (TCO). In these other examples, barrier layer 140 may not be necessary, and conductive layer 130 may directly contact / interface the first dielectric layer 120 and / or the second dielectric layer 150.

[0074] A first dielectric layer 120 is disposed on a window substrate 110. In some embodiments, the first dielectric layer 120 may include multiple discrete portions belonging to different stack assemblies 170, as schematically shown in FIG. 1A. A conductive layer 130 is disposed on the first dielectric layer 120 such that the first dielectric layer 120 is positioned between the conductive layer 130 and each of the window substrate 110. The conductive layer 130 is formed of multiple discrete structures defined by a secondary stack pattern 179. It should be noted that, as described above, the multiple discrete structures allow electromagnetic waves to pass through the signal-permeable energy-saving window assembly 100. A barrier layer 140 is disposed on the conductive layer 130 such that the conductive layer 130 is positioned between the first dielectric layer 120 and the barrier layer 140. Similar to the first dielectric layer 120 and the conductive layer 130, in some embodiments, the barrier layer 140 includes discrete portions. Finally, a second dielectric layer 150 is disposed on the barrier layer 140, such that the barrier layer 140 is positioned between the second dielectric layer 150 and the conductive layer 130. Similar to other components of the signal-permeable energy-saving window assembly 100, the second dielectric layer 150 includes a separation portion.

[0075] The composition and other structural features of each component will now be described in more detail. In some embodiments, the window substrate 110 comprises glass, plastic, or any material capable of supporting at least the first dielectric layer 120, the conductive layer 130, the barrier layer 140, and the second dielectric layer 150. In some embodiments, the window substrate 110 is transparent.

[0076] In some embodiments, the conductive layer 130 provides infrared blocking for energy saving while allowing electromagnetic waves carrying signals to pass through. Some embodiments of suitable materials for the conductive layer 130 include, but are not limited to, silver, silver alloys, copper, gold, indium tin oxide (ITO), etc. In some embodiments, the sheet resistance of the conductive layer 130 is less than 100 ohms / square. In some embodiments, the thickness of the conductive layer 130 is between 5 nanometers and 300 nanometers.

[0077] In some embodiments, the conductive layer 130 comprises or is formed of gold or TCO (e.g., ITO). In these embodiments, a barrier layer is not required (i.e., a barrier layer 140 is absent in these embodiments). The first dielectric layer 120 and the second dielectric layer 150 are formed of the same material. Alternatively, the first dielectric layer 120 and the second dielectric layer 150 are formed of different materials. Generally, suitable materials for the first dielectric layer 120 and the second dielectric layer 150 include, but are not limited to, transparent dielectric materials, such as zinc tin oxide (ZnO). XSn Y O Z The materials used to form the first dielectric layer 120 and / or the second dielectric layer 150 are silicon nitride (Si3N4). In some embodiments, the dielectric conductivity of the materials forming the first dielectric layer 120 and / or the second dielectric layer 150 is less than 1000 S / M (Siemens / meter), or more specifically less than 1 S / M. In some embodiments, the extinction coefficient is less than 0.1 at 550 nm. These materials can be selected for color tuning, for example, to make the boundaries of discontinuous layers invisible. Additional color tuning can be achieved by controlling the thickness of the first dielectric layer 120 and the second dielectric layer 150. For example, the thickness of the first dielectric layer 120 and / or the second dielectric layer 150 can be 10-100 nm. In some embodiments, the first dielectric layer 120 and / or the second dielectric layer 150 allow for vacuum interruption during the manufacture of the signal-transmissible energy-efficient window assembly 100.

[0078] In some embodiments, the conductive layer 130 is patterned, or more specifically formed by discrete structures 132. The dimensions of these discrete structures 132 and the spacing between two adjacent discrete structures 132 are defined by pattern 179. For example, the width (W1) of the discrete structure 132 in the primary stack 171 can be 0.05-5 mm, or more specifically 0.1-2 mm. In the same or other embodiments, the width (W2) of the discrete structure 132 in the secondary stack 172 can be 1-20 micrometers, or more specifically between 2-10 micrometers. The width (W2) should be greater than 2 micrometers to ensure stable photolithography and to account for the budget of overlap width. The width (W2) should be less than 10 micrometers; otherwise, thermal radiation through the secondary stack space at room temperature may be significant, resulting in reduced energy efficiency of the window. These parameters define the transmittance capability of the signal-transmissible energy-efficient window assembly 100 to electromagnetic waves carrying signals.

[0079] In some embodiments, the conductive layer 130 is silver, copper, or gold, or an alloy thereof, and the first dielectric layer 120 may include a dielectric material. In these embodiments, a barrier layer 140 is positioned in contact with (e.g., in direct contact with) the conductive layer 130 (e.g., between the first dielectric layer 120 and the conductive layer 130). In a further embodiment, another barrier layer 140 may be positioned on the other side of the conductive layer 130 (e.g., between the second dielectric layer 150 and the conductive layer 130) to protect the conductive layer 130 from environmental damage (e.g., to protect the silver in the conductive layer 130 from oxidation). In some embodiments, the barrier layer is only layer 140 on top of the conductive layer, and there is no barrier layer below the conductive layer 130. Materials suitable for one or both barrier layers 140 include, but are not limited to, metals or metal oxides, metal nitrides, or metal oxynitrides containing nickel (Ni) or titanium (Ti), such as NiCr, NiCrO. x TiO x NiTiNb, NiTiNbO x In some embodiments, the thickness of the barrier layer 140 is between approximately 1 nanometer and 15 nanometers, or more specifically between 2 nanometers and 10 nanometers.

[0080] Referring to FIG2, in some embodiments, each stack in the stack assembly 170 includes a sidewall 160 of at least one of a barrier layer 140 and a second dielectric layer 150. The sidewall 160 may be naturally formed simultaneously during the deposition of the barrier layer 140 and the second dielectric layer 150. In some embodiments, each of two adjacent sidewalls 160 is jointly formed by the barrier layer 140 and the second dielectric layer 150. The sidewall 160 protects the conductive layer 130 from environmental influences, such as the second dielectric layer 150. In some embodiments, the sidewall 160 extends to the window substrate 110. In some embodiments, the sidewall 160 extends to a first dielectric layer 120 located on top of the window substrate 110.

[0081] Specifically, the sidewall 160 is formed by specifically tailoring the deposition process of the conductive layer 130, the barrier layer 140, and the second dielectric layer 150. In some embodiments, the total sidewall thickness (labeled Tt in FIG2) is between 1 nm and 100 nm, or more specifically between 2 nm and 20 nm. In the same or other embodiments, the contribution of the barrier layer 140 to the total sidewall thickness (labeled T1 in FIG2) is between approximately 0.1 nm and 5 nm, or more specifically between 0.2 nm and 2 nm. Alternatively, the barrier layer 140 is not part of the sidewall 160. In the same or other embodiments, the contribution of the second dielectric layer 150 to the total sidewall thickness (labeled T2 in FIG2) is between approximately 2 nm and 100 nm, or more specifically between 2 nm and 15 nm. Alternatively, the second dielectric layer 150 is not part of the sidewall 160. It should be noted that, due to the deposition angle, the thickness of the portion of the barrier layer 140 and / or the second dielectric layer 150 forming the sidewall may be different (e.g., smaller) than the corresponding thickness of the barrier layer 140 and / or the second dielectric layer 150 away from the sidewall 160.

[0082] Figure 3A illustrates another embodiment of a signal-transmissible energy-efficient window assembly 100, which includes a protective layer 198. In this embodiment, the protective layer 198 adheres to the entire surface of a second dielectric layer 150 and covers the primary stack 171 and secondary stack 172, thereby forming the entire surface of the signal-transmissible energy-efficient window assembly 100 (on one side). Specifically, the protective layer 198 extends to cover all stacks 171. In some embodiments, the protective layer 198 is the sole component forming a sidewall 160. Alternatively, the sidewall 160 may be formed by one or both of the protective layer 198, the barrier layer 140, and the second dielectric layer 150. The thickness of the protective layer 198 can range from 10 nanometers to 100 micrometers (or higher). In some examples, the protective layer 198 is composed of a transparent material with an extinction coefficient of less than 0.1 at 550 nanometers. In the same or other examples, the conductivity of the protective layer 198 is less than 1 S / M.

[0083] In some embodiments, the protective layer 198 is an assembly forming the sidewalls immediately adjacent to the sidewall 160, and also serves as the top dielectric layer of the primary stack 171 and the secondary stack 172. The refractive index of the protective layer 198 can be between 1.5 and 2.1, more specifically between 1.6 and 1.9. In other embodiments, the protective layer 198 is two or more layers with gradient refractive indices, the layers immediately adjacent to stacks 171 and 172 being of a material with a higher refractive index, for example between 1.8 and 2.0, while the materials on the opposite sides, farther from stacks 171 and 172, are of a lower refractive index, for example between 1.5 and 1.7. In these examples, the thickness of the protective layer 198 may range from 10 nanometers to 100 micrometers (or higher). In some examples, the protective layer 198 is composed of a transparent material with an extinction coefficient of less than 0.1 at a wavelength of 550 nanometers.

[0084] In some embodiments, an additional material located on top of the protective layer 198 can be bonded to the additional glass substrate 199, as shown in FIG3A, for example. The additional adhesive layer 197 can be formed of, for example, polyvinyl butyral (PVB), thermoplastic polyurethane (TPU), and / or ethylene-vinyl acetate (crosslinked EVA) to form a laminated glass assembly. The pattern 179 formed by the secondary stack 172 can be visually invisible and imperceptible to the naked eye. In some embodiments, the additional adhesive layer 197 may be used alone or in combination with the protective layer 198, or both, and may be formed of the same material (i.e., having the same composition) or different materials (i.e., having different compositions). The refractive index of the adhesive material may be between 1.5 and 2.1, or more specifically between 1.6 and 1.9, which can enhance the aesthetic properties of the glass assembly.

[0085] Referring to Figure 3B, in some embodiments, the secondary stack 172 is removed (or not formed) before the protective layer 198 is positioned above the stack assembly 170. The removal of the secondary stack 172 may occur naturally during the glass cleaning process or other manufacturing processes, or for other purposes. The protective layer 198 is in direct contact with the substrate. There may be minute or no voids between the protective layer 198 and the substrate or between it and the surface of the main stack 171. From the perspective of signal penetration efficiency, Figure 3A There is no difference between Figure 3A and Figure 3B. However, in terms of visual aesthetic performance, Figure 3A shows better performance in some cases.

[0086] In some embodiments, a signal-transmissible energy-efficient window assembly 100 is placed in an insulated glass unit (IGU) window, which has multiple panes of glass separated by an inert gas or vacuum, and is widely used in buildings. For example, a protective layer 198 is configured to be bonded to an additional window substrate.

[0087] refer to Figure 3C In some examples, the signal-penetrable energy-efficient window assembly 100 consists of multiple low-emissivity (low-E) stacks, such as a stacked 170 and an additional stack 173, distributed on top of the stacked assembly 170. Each low-emissivity stack consists of a first dielectric layer 120, a conductive layer 130, a barrier layer 140, and a second dielectric layer 150. In some examples, at least one or more characteristics (such as composition, thickness, morphology) of the first dielectric layer 120, conductive layer 130, barrier layer 140, and second dielectric layer 150 may differ in different low-emissivity stacks. The stack assembly 170 and the additional stack assembly 173 may have the same rules, or more specifically, the compositions of the stack assembly 170 and the additional stack assembly 173 may overlap. Similar to the stack assembly 170, the additional stack assembly 173 may also include a main stack 171 and a secondary stack group 172. Figure 3C An example is shown with two low-E stacks in the Z direction, but anyone with some skill in the field will understand that any number of low-E stacks can be arranged in this way (e.g., three, four, five or more).

[0088] Similar to Figure 3A or Figure 3B, a protective layer for the laminated glass unit assembly or for bonding to an additional substrate can be applied to the stack shown in Figure 3C.

[0089] Figure 4A A perspective view of the energy-saving light-transmitting window assembly 100 is shown, illustrating different types of stack structures, such as a primary stack structure 171 and a secondary stack structure 172. The secondary stack structure 172 forms a pattern 179.

[0090] For example, pattern 179 could be such that each main stack 171 has a closed shape to ensure electrical isolation between the main stacks 171, or more specifically, electrical isolation between conductive layers in these main stacks 171, thereby enhancing the permeability of the signal-permeable energy-efficient window assembly 100 to wireless communication signals. In a more specific embodiment, each closed shape has a dimension of less than 10 mm in any direction parallel to the window substrate 110, again to enhance the permeability of the signal-permeable energy-efficient window assembly 100. Meanwhile, secondary stacks 172 form pattern lines of pattern 179. These pattern lines extend between each pair of adjacent main stacks 171 and are less than 100 micrometers wide to ensure that these pattern lines are not visible on the signal-permeable energy-efficient window assembly 100. In other words, when a person casually looks at the signal-permeable energy-efficient window assembly 100, the signal-permeable energy-efficient window assembly 100 appears (to the naked eye) as a uniform structure without a pattern.

[0091] Although the primary stack 171 and the secondary stack 172 may have the same structure and composition as individual components, they are formed in different ways. Specifically, the primary stack 171 may be formed directly on the window substrate 110, while the secondary stack 172 is formed over spacers that are removed, resulting in the secondary stack 172 being partially positioned on the window substrate 110 and partially positioned on a portion of the top surface of the primary stack 171. Additional details regarding the formation of the primary stack 171 and the secondary stack 172 will be described below with reference to FIG. 5.

[0092] In some cases, the primary stack 171 is wider than the secondary stack 172. Anyone with ordinary skills will understand how to define the width of an irregular shape. For example, the dimension of a shape in its maximum extension direction can be defined as its length. The width is defined as the maximum dimension perpendicular to the length (e.g., in a plane parallel to the window base 110). It is important to note that both length and width are measured in a plane parallel to the surface of the window base 110. As described below, the width of the secondary stack 172 is determined by spacers used to form a pattern. The width of these spacers can be selected to ensure signal transmission through the signal-permeable energy-efficient window assembly 100.

[0093] refer to Figure 1A and Figure 4AIn some examples, the secondary stack 172 protrudes above the primary stack 171, extending beyond the window substrate 110, and a portion of the stack is located on the top surface of the primary stack 171. In these examples, the primary stack 171 may be directly connected to the window substrate 110, while the secondary stack 172 may be spaced apart from or at least partially away from the window substrate 110. In other examples, the secondary stack 172 is directly connected to the window substrate 110 and the top portion of the primary stack 171, with good adhesion between the primary stack 171 and the secondary stack 172, and between the secondary stack 172 and the window substrate 110 (e.g., by tape adhesion test).

[0094] In some embodiments, as shown in Figure 4B, the edges of the patterned lines are roughened, with a line edge roughness (LER) greater than 100 nanometers. LER is defined as the root mean square deviation of the line edge profile shape from a straight line over a measurement length of 1 micrometer. In some embodiments, the LER is at least 10 nanometers, at least 20 nanometers, or even at least 100 nanometers. Roughened line edges exhibit less photoresist residue overall after cleaning, resulting in better visual aesthetics.

[0095] Process Example

[0096] Figure 5 is a process flow diagram of a method 300 for forming a signal-transmissible energy-saving window assembly 100, according to some embodiments. Various examples of the signal-transmissible energy-saving window assembly 100 have been described above.

[0097] Method 300 may begin by forming a spacer pattern (block 310) 180 on the window substrate 110. This spacer pattern defines a gap pattern 179, i.e., the gap is formed during subsequent removal of the 180 spacers. For example, the pattern of the 180 spacers can be formed using photolithography, such as... Figures 6A-6D As shown in the schematic diagram. Specifically, Figure 6A A processing stage is illustrated in which a continuous coating underlayer 410 is formed on the window substrate 110. Underlayer 410 is an optional component; in some cases, it is absent. Underlayer 410 can be used to create inverted trapezoids at intervals 180, for example, as shown in the figure below and referenced. Figure 6D .

[0098] Figure 6B illustrates a processing stage in which a photoresist layer 420 is formed over a substrate 410. In some embodiments (e.g., when the substrate 410 is not formed), the photoresist layer 420 is in direct contact with the window substrate 110 (not shown). The photoresist layer 420 may also be formed as a continuous coating. The photoresist layer 420 may be formed as a positive or negative photoresist, depending on whether the exposed portion of the photoresist layer 420 is soluble or insoluble in the photoresist developer.

[0099] Figure 6C The processing stages of photoresist layer 420 are demonstrated, such as exposure using photomask 430. Finally, Figure 6D The process stages following etching and cleaning of the photoresist layer 420 and (if any) the underlayer 410 are illustrated. Specifically, the photoresist layer 420 is transformed into the head 189 of the spacer, while the underlayer 410 (if present) is transformed into the bottom 188 of the spacer. The materials of the photoresist layer 420 and the underlayer 410 can be selected such that the etching rate of the underlayer 410 is faster than that of the photoresist layer 420. For example, MicroChem offers three material combinations for the underlayer 410 material, such as LOR A, LOR B, or LOR C material products. The photoresist layer 420 can be made of PMGI photoresist. The head 189 and the bottom 188 of the spacer are collectively referred to as the spacer 180. Therefore, the width of the bottom 188 of the spacer is smaller than that of the head 189 of the spacer, resulting in the spacer 180 being an inverted trapezoidal shape. In some examples, the width difference on each side ( Figure 6D W in d Also known as overhangs, these are approximately 200-3000 nanometers long, more specifically 500-2000 nanometers. In the same or other examples, the bottom of spacer #188 ( Figure 6D The height of HB in the image is 200-800 nanometers, more specifically 300-600 nanometers. Furthermore, spacecraft number 180 (… Figure 6D The total height of the HT in the medium is 300-5000 nanometers, more specifically 400-1200 nanometers.

[0100] While Figures 6A-6D illustrate an embodiment using two layers to form the spacer 180, those skilled in the art will understand that a single layer or more than two layers can be used to form spacers 180 with similar shapes. Specifically, the spacer 180 may have an inverted trapezoidal structure defined by the bottom etched structure. Such an embodiment is schematically shown in Figure 6E. As described above, the bottom etched structure facilitates the separation between the separation structures 132, as further described below.

[0101] Referring to FIG. 6E, each spacer 180 has a surface 181 in contact with the substrate and a top surface 182 opposite to the surface in contact with the substrate 181. The width of the top surface 182 is greater than the width of the surface in contact with the substrate 181. In some embodiments, the difference between the width of the top surface 182 and the surface in contact with the substrate is greater than 1,000 nm, or even greater than 2,000 nm. In the same or other embodiments, the photoresist thickness or more generally, the spacer height is less than 2,000 nm, or even less than 1,000 nm.

[0102] In summary, the pattern of the spacer 180 can be formed by photolithography, material extrusion, nozzle jetting or mechanical indirect deformation, such as by using a mold, stamp, or by curing by a laser, ultraviolet source or electron beam or other heat source, or a combination of these techniques.

[0103] Returning to Figure 5, method 300 then deposits (box 320) a stack assembly 170 over the window substrate 110 and over the patterned spacer 180. As described above, the stack assembly 170 includes a first dielectric layer 120, a conductive layer 130, a barrier layer 140, and a second dielectric layer 150. Each layer is formed in a separate operation, for example, using physical vapor deposition (PVD). Figures 7A-7D illustrate the different stages in this stack formation operation. Specifically, Figure 7A illustrates a patterned spacer 180 (with an inverted trapezoidal shape / bottom etched structure) positioned over the window substrate 110. Figure 7B illustrates a conductive layer 130 formed over the window substrate 110 and the spacer 180 and including a separation structure 132 defined by the patterned spacer 180. These separation structures 132 are formed because the spacers 180 protrude above the window substrate 110 (due to the thickness of the protrusion, a break is effectively formed in the conductive layer 130).

[0104] Various methods for controlling the deposition extension (forming each layer in the stack) and the photoresist (PR) bottom etching structure region for the deposition of the barrier layer 140 and the second dielectric layer 150 are within the scope of this invention.

[0105] The sidewall protection of conductive layer 130 (with barrier layer 140 and second dielectric layer 150) has demonstrated excellent environmental and thermal durability. Environmental durability was tested by immersing the sample in a container of boiling water for one hour. Thermal durability was tested by baking a thick coating at 650°C for 8 minutes on a 3 mm thick glass substrate, or baking a 0.5 mm thick glass coating at 650°C for 7 minutes. No obvious defects were found under microscopic examination. These sidewall conductive layer protection designs and methods are applicable to any number of layers in a stack.

[0106] These sidewall conductive layer protection designs and methods are applicable to any type of stack and any number of layers in each stack. Highly non-directional processes (e.g., high-voltage processes) and directional processes (e.g., low-voltage processes) are both within the scope of this invention.

[0107] In some embodiments, method 300 includes depositing (box 330) one or more additional stacks over a stack assembly 170 disposed above the window substrate 110 and spacers 180. Specifically, various operations of depositing the first dielectric layer 120, the conductive layer 130, the barrier layer 140, and the second dielectric layer 150 (as described above) may be repeated once or multiple times.

[0108] In some embodiments, method 300 includes removing (box 340) spacer 180 from a signal-permeable energy-efficient window assembly 100. For example, the signal-permeable energy-efficient window assembly 100 may be tempered (e.g., subjected to high temperatures) to convert spacer 180 into volatile substances that are removed from the environment by oxygen (e.g., air). The spacer material may also be removed or partially removed by a plasma process using a gas containing oxygen and / or nitrogen. For example, spacer 180 may contain a material that can be completely burned off in an oxygen-containing environment (e.g., air) without leaving any residue. In some embodiments, spacer 180 contains one or more of the following five elements: carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and sulfur (S). The absence of other elements in the spacer composition ensures residue-free removal of spacer 180.

[0109] In some embodiments, conventional oxygen-based photoresist removal methods, including oxygen plasma or high-temperature oxygen techniques, typically result in the retention of significant residues 194. These residues are typically present between the secondary stack 172, the window substrate 110, and the main stack 171. Such residues 194 can lead to the formation of large voids 190 (e.g., hundreds of nanometers) between the main stack 171 and the secondary stack 172, or between the window substrate 110 and the secondary stack 172. This, in turn, can cause noticeable tiny reflective spots when exposed to strong light (e.g., direct sunlight), which is undesirable.

[0110] In some embodiments, removal of the spacer 180 (e.g., comprising photoresist) involves immersing the window substrate 110, with the spacer 180 and stack assembly 170 (e.g., comprising a metal, oxide, or nitride material), in a processing solution (process 342 in FIG. 5 flow chart), followed by high-temperature treatment in a temperature-controlled oven (process 346 in FIG. 5 flow chart). Specific embodiments of the processing solution and high-temperature treatment are described below. This spacer removal process demonstrates superior performance in minimizing the amount of photoresist residue after treatment. In some examples, residual gaps are minimized to less than 200 nanometers, more specifically, less than 100 nanometers, and even completely free of residue and gaps. Furthermore, this spacer removal process enhances the adhesion of the secondary stack 172 to the window substrate 110 and the main stack 171, thus reducing the visibility of tiny reflective points even under strong light conditions.

[0111] The processing solution (process 342 in Figure 5) may contain one or more solvents selected from the group consisting of ketones, alcohols, esters, and ethers, such as acetone, isopropanol (IPA), methyl ethyl ketone (MEK), dimethyl carbonate (DMC), and ethyl acetate. Specifically, these solvents may contain one or more of the following functional groups: C=O, -OH, COO, and COC, which exhibits excellent properties for converting the photoresist into an organic thin film connecting stack 172 to the substrate and the surface of stack 171. The molecular weight of these solvents is less than 300 g / mol or less than 100 g / mol to ensure low viscosity.

[0112] Viscosity can be less than 0.01 Pa·s. For example, solvents with higher viscosity, such as propylene glycol monomethyl ether acetate (PGMEA), while a widely used photoresist cleaning solvent and effective for photoresist removal, may undesirably strip secondary stacks 172, making them inconvenient to use. Aromatic hydrocarbons, such as toluene and xylene, can effectively clean photoresist but are toxic.

[0113] Furthermore, the water content of the processing solution can be less than 10%, as water can damage the conductive layer 130 (e.g., silver). The solvent may also not be acidic or alkaline, with a pH value limited to between 6.5 and 7.5, and may not contain ammonia, as ammonia (like water) can also damage the conductive layer 130 (e.g., silver).

[0114] In some embodiments, this spacer removal process may involve immersion in only one processing solution followed by high-temperature treatment. Alternatively, a sequential immersion process in two or more different processing solutions (with different compositions) may be used. For example, the initial processing solution / solvent may be selected from the list mentioned in the preceding paragraphs (process 342). A second processing solution / solvent may be used to clean the sample surface (process 344).

[0115] Specifically, the initial processing solution / solvent (dissolving photoresist) may leave residues in areas outside the pattern lines. A second processing solution / solvent (process 344 in Figure 5) effectively cleans these residues. The criteria for selecting the second solvent are based on the following: (a) Compatibility: The second solvent must be compatible with the initial solvent, meaning it should be able to dissolve or suspend any residues left by the initial solvent. (b) Volatility: Generally, it is desirable to have higher volatility than the initial solvent. This ensures that it can evaporate quickly and completely, leaving no residue. (c) Non-reactiveness: The second solvent should not react with or damage any other materials in the substrate or system. (d) Cleaning efficiency: The second solvent should have good residue-dissolving ability while being mild enough not to affect the underlying pattern or materials. (e) Environmental and safety considerations: The second solvent should be less hazardous and more environmentally friendly. Some examples of second solvents include one or a mixture of acetone, isopropanol (IPA), ethanol, and methanol. Specific combinations of the initial solvent and the second solvent include, but are not limited to: (1) dimethyl carbonate and (2) acetone, (1) methyl ethyl ketone (MEK) and (2) acetone, and (1) ethyl acetate and (2) acetone.

[0116] In some embodiments, a high-temperature treatment process (process 346 in Figure 5) follows the chemical solvent post-cleaning process. It should be noted that the high-temperature glass treatment process is optional and depends on the product application requirements. Specifically, the high-temperature glass treatment involves passing the signal-transmissible energy-efficient window assembly 100 through a furnace heated to above 600°C or even above 800°C. The specific duration of this high-temperature glass treatment is designed to enhance the strength and thermal stress resistance of the glass.

[0117] In some embodiments, a transparent organic layer 196 is positioned between the secondary stack 172 and the window substrate 110 / main stack 171. This transparent organic layer 196 is formed by combining the remaining portion of photoresist and solvent. After the transparent organic layer 196 is baked at high temperature (a typical glass coating process), it acts as an adhesive intermediary, ensuring strong adhesion of the stack 172. The transparency of the transparent organic layer 196 ensures that no pattern is visible even under direct sunlight. Furthermore, the signal-transmissible energy-efficient window assembly 100 consistently passes adhesion tests, such as tape tests. The transparent organic layer 196 is characterized by a significant carbon content (e.g., greater than 10% atoms) and differs (based on composition) from the main stack 171, the secondary stack 172, and the window substrate 110. The thickness of this transparent organic layer 196 is less than 200 nanometers, more specifically less than 100 nanometers, and even less than 20 nanometers. In some cases, there are no gaps or empty spaces inside or next to the organic layer 196.

[0118] It should be noted that the stack assembly 170 (which may be referred to as secondary stack 172) positioned above the spacer 180 is effectively lowered onto the window substrate 110. In some embodiments, method 300 includes forming (box 350) a protective layer 198 located above the stack assembly 170, covering the entire surface of the second dielectric layer 150 on one side of the signal-transparent energy-efficient window assembly 100. Furthermore, this signal-transparent low-emissivity coated glass can also be laminated with another glass substrate, similar to FIG. 3A.

[0119] Examples of other modes

[0120] Referring to Figures 8A-8I, in some embodiments, a dry film photoresist 920 is used (instead of the wet photoresist process described above with reference to Figures 5 and 6A-6D). Specifically, the dry film photoresist 920 includes a release layer 922, an inner layer 926, and a dry film photoresist layer 924 positioned between and encapsulated by the release layer 922 and the inner layer 926. Each of the release layer 922 and the inner layer 926 may be made of one or more of polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl chloride (PVC), and polyethylene (PE).

[0121] It should be noted that traditional two-layer processes involve coating a substrate with wet photoresist (liquid). These processes require expensive photolithography equipment and can be quite complex. Dry film photoresist processes can be implemented using less complex equipment, such as those that do not require expensive exposure and optical systems. However, dry film photoresist presents various challenges in achieving small features due to its loose structure.

[0122] Referring to Figure 8A, a bottom photoresist layer 910 is coated onto the window substrate 110, which can be achieved using a slot coater on a large-sized substrate. The bottom photoresist layer 910 may contain one or more organic materials. The viscosity (of the coating material) can be 1-10,000 centipoise (cP). The thickness of the bottom photoresist layer 910 can be 0.5-5 micrometers, or more specifically 1-2 micrometers. The process can continue to cure the bottom photoresist layer 910 (from Figure 8A to...). Figure 8B The transformation can be achieved by using ultraviolet light exposure or soft baking at approximately 70-200°C for 1-30 minutes (e.g., baking at 105°C for 10 minutes). This process transforms the bottom photoresist layer 910 into a solid-like state, as shown in Figure 8B.

[0123] As shown in Figure 8C, the dry film photoresist 920 includes a release layer 922, an inner layer 926, and a dry film photoresist layer 924. First, the inner layer 926 is peeled off to expose the dry film photoresist layer 924, as shown in Figure 8D, and it can be deposited on a near-solid underlayer film, as shown in Figure 8E. Then, heated lamination rollers push the dry film photoresist layer 924 and the underlayer photoresist layer 910 together to remove air bubbles at the edges, as shown in Figure 8F. This lamination operation can be performed at a temperature of 50-200°C (e.g., 70°C). The thickness of the dry film photoresist layer 924 can be 2-50 micrometers, or more specifically 5-15 micrometers.

[0124] In the next step, the release layer 922 can be removed, and the remaining structure, or more specifically, the combination of the dry film photoresist layer 924 and the bottom photoresist layer 910, can be exposed using a mask 930, as shown in Figure 8H. A set of spacers 180 defined by the mask pattern is formed by a development step, as shown in Figure 8I, for example. Specifically, the cross-sectional profile of the pattern can be modified using a double-layer stack, developer solution, and specific process conditions.

[0125] The advantage of this dry film photoresist process lies in the significant simplification of exposure, masking, and related optical systems, thereby reducing costs and improving process stability. Specifically, the dual-layer structure initially arises from (i) a three-layer structure of a dry film photoresist 920 film with two protective layers on both sides and (ii) a bottom solid-like material. Furthermore, a unique intermediate structure is generated, comprising a window substrate 110, a bottom photoresist layer 910, a dry film photoresist layer 924, and a release layer 922, as shown in Figure 8E, for example. This process uniquely involves peeling off the release layer 922 and laminating the dry film photoresist layer 924 with the bottom photoresist layer 910 (which may be a solid-like bottom material) disposed on the window substrate 110.

[0126] The bottom photoresist layer 910 is initially in a liquid state, suitable for uniform coating, for example, using a slot coater. During curing operations (such as heat treatment or UV exposure), the bottom photoresist layer 910 transforms into a near-solid state to form a stable thin film. Furthermore, the bilayer structure (comprising the bottom photoresist layer 910 and the dry film photoresist layer 924) can utilize different developers to control different layer structures. Since common dry film photoresists, such as Riston ST900 dry film PR, can be developed with alkaline developers, the cured bottom material needs to be resistant to alkaline developers and not corroded. Alternatively, some special dry film PRs are developed with non-alkaline solutions, such as Nagase's DF-2005, which uses cyclohexanone as a developer. In this case, the bottom material could be Kayaku Advanced Materials' LOR-A, which uses an alkaline solution as a developer.

[0127] Several embodiments integrate the bottom photoresist layer 910 (which may be referred to as wet photoresist) with the Riston ST900 dry film PR or Nagase dry film, and the low emissivity coating performance in optical, thermal, and durability tests meets product specifications: polyimide, SU-8 photoresist (a commonly used epoxy-negative photoresist), or Kayaku Advanced Materials' LOR-A. Specifically, polyimide, as the bottom coating material, is initially in a liquid state, uniformly coated using a slot coater, and cured at 200°C to form an alkali-resistant film. This film can be removed or etched using NMP solvents. SU-8 photoresist, as the bottom coating material, is initially in a liquid state, uniformly coated using a slot coater, cured by UV exposure and subsequent baking at 95°C to form an alkali-resistant structure. This structure can be removed using acetone or PGMEA solvents. Kayaku Advanced Materials' LOR-A, used as the base material, is initially in a liquid state, uniformly coated using a slot coating device, and cured by baking at 105°C. It resists the cyclohexanone developer of the dry film PR DF-2005. The structure can be removed using an alkaline solution developer.

[0128] Following the dry film photoresist photolithography process in Figures 8A-8I, a pattern of spacers 180 is formed on the window substrate 110, corresponding to the patterning operation (box 310 in Figure 5). The remaining operations can be the same as in Figure 5; for example, a low emissivity stack can be deposited in the corresponding deposition operation (boxes 320-350 in Figure 5).

[0129] In some embodiments, as shown in FIG8I, the non-bottom etched profile of the photoresist can allow moving signals to penetrate patterned low-emissivity coated glass after a special processing step. We found that photoresist thickness can significantly affect the penetration of moving signals at rectangular or trapezoidal profile photoresist. FIG9A is a schematic diagram of an energy-saving coating structure, which, according to some embodiments, includes patterned lines attached to a substrate. According to some embodiments, the structure in FIG9A can be applied iteratively on a window substrate. For example, when the photoresist thickness is 0.5 micrometers, moving signals are blocked by the patterned low-emissivity coated glass. However, increasing the photoresist thickness to 1.5 micrometers or 5 micrometers or more, and applying special processing, such as heat treatment at 650°C for 7 minutes and surface cleaning on a 1-millimeter-thick glass, can allow moving signals to penetrate the patterned low-emissivity coated glass. Further research has found that with a thicker photoresist, the low-emissivity coating on top of the photoresist can crack after heat treatment in conjunction with other activities, such as naturally occurring during glass cleaning or other production processes. The coating can then present the form shown in FIG9B or FIG9C. The photoresist spacers are almost completely burned off during thermal processing, and the coating on top of or to the sides of these spacers cracks or peels off during post-cleaning processes or other manufacturing procedures, resulting in a physical discontinuity of the conductive layer along the spacer pattern. The remaining conductive coating of multiple secondary stacks, originally located on top of or to the sides of the spacers, exhibits a significantly different distance from the substrate surface compared to the conductive coating of the main stack, ranging from at least 50 nanometers to 50 micrometers. The multiple secondary stacks crack on top of or to the sides of the spacer pattern, becoming physically isolated, thus causing the conductive layer to be discontinuous along the spacer pattern. The assembly includes non-conductive structures within the conductive layer, forming an electrically isolated main stack and partially secondary stacks along the spacer pattern.

[0130] Any special process that meets the requirements for mobile signal penetration is within the scope of this patent: forming a non-conductive structure within a conductive layer to create a main stack electrically isolated by spacer patterns.

[0131] In some embodiments, layer 910 shown in Figures 8A and 8B may be omitted, or the process may begin directly from Figure 8C without including Figures 8A and 8B. In this case, the dry film is directly coated onto the substrate 110.

[0132] In some embodiments, the protective layer 198 adheres to the entire surface of the second dielectric layer 150, covering the entire surface (on one side) of the signal-transmissible energy-efficient window assembly 100. Excellent durability performance is still achieved after six months of exposure to environmental conditions.

[0133] This type of signal-transparent, low-emissivity coated glass can also be laminated with another glass substrate, similar to...Figure 3A However, the coating is replaced by that shown in Figure 9A. In some embodiments, the additional adhesive layer 197 may be made alone or in combination with the protective layer 198, or both, and may be made of the same material (i.e., having the same composition) or different materials (i.e., having different compositions).

[0134] Experimental results

[0135] Various tests were conducted to evaluate the performance of the signal-transmissible energy-saving window assemblies prepared according to the various embodiments described above. Uncoated glass samples and conventional low-emissivity coated samples were used as references. The results are presented in Figure 10.

[0136] Specifically, both the conventional low-emissivity coating sample and the signal-transmissible energy-saving window assembly with a patterned conductive layer used the same low-emissivity stack: a first dielectric layer formed of ZnSnO, a conductive layer formed of silver, a barrier layer formed of NiCr alloy, and a second dielectric layer formed of ZnSnO. The overall coating size was 55 mm x 55 mm. The pattern pitch was 0.25–0.5 mm, and the pattern line width was 4–5 micrometers.

[0137] Referring to Figure 10, the electromagnetic wave penetration of wireless signals (such as cell phone signals) was tested using the following method. A heavy-duty 16 GA welded steel box was left with a 50 mm by 50 mm window opening. The box simulated a building that electromagnetic waves could not penetrate. Only the window in the box allowed electromagnetic wave penetration. The signal source used for this experiment was a 5 GHz (60 mm wavelength) router. A cell phone, APPLE® iPhone® 7, was used as the signal receiver. The phone was equipped with a software application **“AirPort Utility”** to measure Wi-Fi signal strength and recorded the Wi-Fi signal data received by the phone every 5 seconds. The phone was placed inside the box facing the window. Reference tests using blank substrate glass on the window in the box showed a signal strength of approximately -45 dBm, which was the reference baseline for the Wi-Fi signal in the box. Low-emissivity coated glass was tested on the window as another reference, and the signal strength in the box ranged from approximately -75 dBm to -72 dBm. Therefore, due to the low-emissivity coating on the glass, the two different glass samples showed a difference of nearly 30 dBm, or a signal strength reduction of approximately 1000 times. Then, two prototype samples of low-emissivity coated glass with the pattern of this invention were tested on a window; the signal strength in the box decreased only slightly, to approximately -50 dBm, a difference of only about 5 dBm from the pure glass. These results clearly demonstrate that the prototype samples of patterned low-emissivity coated glass significantly improve Wi-Fi signal transmission.

[0138] in conclusion

[0139] Although the foregoing concepts have been described in some detail for the purpose of clarity, it will be apparent that certain changes and modifications can be made within the scope of the appended terms. It should be noted that many alternative methods exist for implementing these processes, systems, and devices. Therefore, the present embodiments should be considered illustrative rather than restrictive.

Claims

1. A signal-transmissive, energy-saving window assembly, comprising: a window substrate; a first dielectric layer disposed on the window substrate; a conductive layer disposed on the first dielectric layer such that the first dielectric layer is between the conductive layer and the window substrate, wherein the conductive layer is formed of a plurality of separate structures separated by gaps; and a second dielectric layer disposed on the conductive layer such that the conductive layer is between the second dielectric layer and the first dielectric layer, wherein: the first dielectric layer, the conductive layer, and the second dielectric layer form a plurality of primary stacks and a plurality of secondary stacks on at least a portion of the window substrate the plurality of secondary stacks form a pattern defined as pattern lines, some on the window substrate and some on top surfaces of the plurality of primary stacks, and a width of each of the pattern lines is at least 0.4 micrometers greater than the gaps separating the plurality of separate structures.

2. The signal-transmissive, energy-saving window assembly of claim 1, wherein the second dielectric layer comprises a barrier material comprising one of nickel or titanium.

3. The signal-transmissive, energy-saving window assembly of claim 1, wherein each of the plurality of secondary stacks directly contacts the window substrate.

4. The signal-transmissive, energy-saving window assembly of claim 1, wherein each of the plurality of secondary stacks is connected to the window substrate and the plurality of primary stacks by a connecting layer comprising (a) a continuous layer of material or (b) a combination of a non-continuous layer of material and air voids.

5. The signal-transmissive, energy-saving window assembly of claim 4, wherein the connecting layer comprises carbon at an atomic concentration greater than 10%.

6. The signal-transmissive, energy-saving window assembly of claim 4, wherein the connecting layer has a thickness of 1-1000 nanometers.

7. The signal-transmissive, energy-saving window assembly of claim 4, wherein the connecting layer is formed by a solution treatment, the solution comprising at least one functional group selected from the group of C=0, -OH, COO, and C-O-C functional groups.

8. The signal-transmissive, energy-saving window assembly of claim 1, wherein each of the plurality of secondary stacks has a width between 1 micrometer and 100 micrometers.

9. The signal-transmissive, energy-saving window assembly of claim 1, further comprising a protective layer disposed on the plurality of primary stacks and the plurality of secondary stacks.

10. The signal-transmissive, energy-saving window assembly of claim 9, wherein the protective layer comprises a transparent material having an index of refraction between 1.6 and 1.9 at a wavelength of 550 nanometers.

11. The signal-transmissive, energy-saving window assembly of claim 1, further comprising an additional window substrate, wherein the first dielectric layer, the conductive layer, and the second dielectric layer are between the window substrate and the additional window substrate.

12. The signal-transmissive, energy-saving window assembly of claim 1, wherein each of the plurality of primary stacks comprises two adjacent sidewalls formed by the second dielectric layer extending downward to the substrate and completely encapsulating the conductive layer between the substrate and the second dielectric layer.

13. The signal transparent energy saving window assembly of claim 1, wherein the width of the secondary stacks is between 2 and 10 microns.

14. A signal transparent energy saving window assembly, comprising: a window substrate; a first dielectric layer disposed on the window substrate; a conductive layer disposed on the first dielectric layer such that the first dielectric layer is between the conductive layer and the window substrate, wherein the conductive layer is formed of a plurality of separate structures separated by gaps; and a second dielectric layer disposed on the conductive layer such that the conductive layer is between the second dielectric layer and the first dielectric layer, wherein: the first dielectric layer, the conductive layer, and the second dielectric layer form a plurality of primary stacks, each primary stack comprising two sidewalls and being separated from one another by gaps, the gaps forming a pattern defined by pattern lines, and the width of the pattern lines is greater than the gaps separating the plurality of separate structures by between 0.4 and 6 microns.

15. The signal transparent energy saving window assembly of claim 14, further comprising a protective layer disposed on the plurality of primary stacks, the protective layer comprising a transparent material having an electrical conductivity less than 1 S / m.

16. The signal transparent energy saving window assembly of claim 14, further comprising an additional window substrate, wherein the plurality of primary stacks is between the window substrate and the additional window substrate.

17. A signal transparent energy saving window assembly, comprising: a window substrate; non-conductive spacers forming a pattern on the window substrate, contacting and obscuring a portion of the window substrate; a first dielectric layer contacting the window substrate and the non-conductive spacers; a conductive layer disposed on the first dielectric layer such that the first dielectric layer is between the conductive layer and the window substrate or the non-conductive spacers; a second dielectric layer disposed on the conductive layer such that the conductive layer is between the second dielectric layer and the first dielectric layer; non-conductive structures on the conductive layer forming a plurality of primary stacks and a plurality of secondary stacks, wherein: the first dielectric layer, the conductive layer, and the second dielectric layer form the plurality of primary stacks in areas not occupied by the spacers; at least a portion of the first dielectric layer, the conductive layer, and / or the second dielectric layer on a top surface or a side surface of the spacers forms the plurality of secondary stacks; the plurality of secondary stacks forms a pattern defining spacer pattern lines, some on the window substrate and some on a top surface of the plurality of primary stacks, the spacer pattern lines comprising a top surface and a side surface, the stacks breaking on the top surface or the side surface of the spacer pattern lines, thereby physically isolating the stacks and making the conductive layer discontinuous along the spacer pattern lines.

18. The signal transparent energy saving window assembly of claim 17, wherein the spacer pattern lines are formed using a photoresist process with a photoresist thickness greater than 1.5 microns.

19. The signal transparent energy saving window assembly of claim 17, further comprising a protective layer formed on the stacks, the protective layer comprising a transparent material having an electrical conductivity less than 1 S / m.

20. The signal- penetrable energy saving window assembly of claim 17, wherein the stack is adhered to an additional window substrate such that the stack and the non-conductive spacer are located between the window substrate and the additional window substrate.

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