Heat radiation control of heat sink heater matrix

Abstract

The present invention relates to a heater matrix comprising a plurality of heater pixels and electrical connections for the heater pixels, and a method for manufacturing the heater matrix. Each of the heater pixels includes a resistive pattern mounted on or embedded in the surface of a substrate, the resistive pattern being made of a layer of a first conductive material, and the resistive pattern having a first resistivity. The electrical connections include electrical wiring mounted on or embedded in the surface of the substrate, the electrical wiring being made of a layer of a second conductive material, and the electrical wiring having a second resistivity, the second resistivity being lower than the first resistivity.

Description

Technical Field

[0001] The present invention relates to a radiator heating matrix. More particularly, the present invention relates to radiation control of a radiator heater matrix.

Background Art

[0002] Recently, due to the increase in energy prices, people's cost awareness has been increasing. It is well known that reducing the indoor temperature reduces energy consumption. For example, the energy cost decreased by 5% for every 1°C decrease in the indoor temperature. Reducing energy consumption reduces CO2 emissions. Since electricity is easy to produce and supply to consumers, electricity is the most common type of green energy produced by using renewable energy sources such as solar power, wind power, and low-load hydroelectric power facilities.

[0003] Keeping the room temperature low when no one is present and raising the room temperature to a comfortable temperature when people are present leads to energy savings. The comfortable temperature varies from person to person. If the temperature of a room or other indoor space is too low or too high, it causes discomfort and a decrease in work efficiency. Unfortunately, the temperature control of existing indoor heating systems is too slow to change the temperature profile of a space according to the occupancy situation. Furthermore, in practice, since the temperature of a building can only be controlled at the room level, local temperature differences within the space are not allowed.

[0004] A heater matrix having a plurality of individually controllable heater pixels provides a solution that enables creating a microclimate having a temperature within a comfortable temperature range within an indoor space and keeping the overall temperature maintained by a conventional heating system lower than the comfortable temperature range. In order to enable a rapid response, the heater pixels are preferably embedded near the front surface of a sheet of various indoor building materials and / or decorative materials used for floors, walls, ceilings, and even furniture. The heater pixels of such a heater matrix include a resistive heater pattern that is electrically heated.

[0005] Such heater matrix-based auxiliary heating systems require operational reliability and safety. The current used to heat the heater pixels must be high enough to heat them quickly, while at the same time ensuring that even with low voltage, high currents do not pose a fire risk at any point. The main sources of malfunction and hazard are the electrical wiring supplying power to the heater pixels and the connections between the various electrical elements of the heater matrix. Poor electrical connections between two electrical elements can cause the creation of hot spots, which can lead to equipment failure and even a fire risk. Electrical wiring supplying power to multiple heater pixels may carry a larger current than that to individual heater pixels.

[0006] In commercially available heater foil products, copper is used as a busbar in carbon paste-based heater foils. The copper busbar is bonded to the carbon paste heater element using silver paste, which forms an electrical connection between the copper and carbon. However, problems arise when busbars and / or other wiring are connected to a power source using adhesive or crimp connectors, as this makes them prone to hot spots. Adhesives tend to become brittle over time, and crimp connector connections can degrade due to mechanical movement caused by temperature changes. Hot spots caused by poor connections can pose a safety hazard. Furthermore, the use of copper busbars is expensive, and carbon paste has poor connectivity, making it impractical to use for creating electrical wiring for power supply. Silver paste is expensive and has a significant environmental impact.

[0007] Soldering is a well-known method for electrically connecting conventional electronic devices. However, connection bridges are typically made of insulating material and conductive paste, such as silver paste adhesive. However, silver paste adhesion is unreliable. Polyimide (PI) film-based flexible circuit boards can also be bonded using conventional high-temperature soldering, but polyimide is expensive and therefore not considered a commercially preferred alternative when large quantities are needed.

[0008] So-called crimp connections are a known alternative to soldering, where the crimp connector is crimped onto a wire, and the crimp connector is further mechanically attached to a circuit board or a film supporting the connector, for example, by pins or claws pressed into the wire lines on the circuit board, or even by screws. However, such mechanical crimp connections are unreliable because the connection can come loose and / or various surfaces of the connection can oxidize, creating hot spots.

[0009] U.S. Patent Publication No. 2021080121A1 discloses a heating mat for surface heating of a room in a building. The electric heating unit is positioned on the first base side of the carrier element so that the base unit can be placed flat on top of the surface heating system.

[0010] Korean Patent Publication No. 20200009660A discloses a band heater system that can be installed on objects such as gas pipes. The band sections can be connected to each other by connectors at both ends of the band section.

[0011] European Patent No. 3443810B1 discloses a carbon nanomaterial-based electric heater element comprising electrodes and a carbon nanomaterial-containing layer arranged on a substrate. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] U.S. Patent Publication No. 2021080121A1 [Patent Document 2] Korean Patent Publication No. 20200009660A [Patent Document 3] European Patent No. 3443810B1 [Patent Document 4] International Patent Application No. WO2022 / 234189 [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] The objective is to provide an apparatus for reliably establishing electrical connections between heater pixels of a heater matrix and a power supply, while avoiding safety issues such as hot spots in the electrical contact area and parasitic heating of wiring, as well as a method for manufacturing such an apparatus. The object of the present invention is achieved by the heater matrix and heater matrix manufacturing process according to the independent claims.

[0014] Preferred embodiments of the present invention are disclosed in the dependent claims. [Means for solving the problem]

[0015] The present invention is based on the idea of ​​selecting and / or designing the materials for the conductive heater patterns of heater pixels on a substrate and the electrical wiring on the substrate, particularly power supply lines, such that the resistivity of the conductive heater pattern is higher than that of the electrical wiring. Thus, the current in the electrical wiring does not significantly raise its temperature when energized, but the temperature of the heater pattern made of a higher-resistivity material rises with the current according to Ohm's law.

[0016] According to a first embodiment, a heater matrix is ​​provided comprising a plurality of heater pixels and electrical connections for the heater pixels. Each of the heater pixels comprises a resistive pattern mounted on or embedded in the surface of a substrate. The resistive pattern is made of a layer of a first conductive material and has a first resistivity. The electrical connections comprise electrical wiring mounted on or embedded in the surface of a substrate. The electrical wiring is made of a layer of a second conductive material and has a second resistivity, the second resistivity being lower than the first resistivity.

[0017] According to some embodiments, the electrical connection further comprises a plurality of connection bridges that provide an electrical connection between the heater pixel and the electrical wiring.

[0018] According to some embodiments, multiple connection bridges are electrically connected to the heater pixels and the electrical wiring by soldering.

[0019] According to some embodiments, the solder paste used for soldering is a low-temperature solder paste configured to self-heal the electrical connection through the solder paste if a hot spot occurs due to loosening of the connection.

[0020] According to some embodiments, multiple connection bridges are electrically connected to the heater pixels and the electrical wiring by mechanical-electrical connectors such as crimp connectors.

[0021] According to some embodiments, multiple connection bridges are mechanically and electrically connected to the heater pixels and the electrical wiring by an anisotropic conductive film (ACF) or anisotropic conductive paste (ACP).

[0022] According to some embodiments, the plurality of connection bridges are mechanically and electrically connected to the heater pixels and the electrical wiring by an isotropic conductive film (ICF) or an isotropic conductive adhesive (ICA).

[0023] According to some embodiments, the plurality of connection bridges are further fixed on the substrate by an adhesive.

[0024] According to some embodiments, the first conductive material is brass, bronze, zinc, nickel, aluminum or copper, and the second conductive material is copper.

[0025] According to some embodiments, both the layer of the first conductive material and the layer of the second conductive material have a thickness of 0.5 to 50 micrometers, preferably 10 to 30 micrometers, more preferably 10 to 20 micrometers.

[0026] According to some embodiments, the electrical wiring includes at least one power supply line and at least one ground supply line, and the electrical wiring further provides a data connection. The data connection is carried by at least one power supply line or by one or more dedicated data communication lines.

[0027] According to some embodiments, the plurality of connection bridges include at least one master connection bridge and at least one slave connection bridge. At least one master connection bridge is coupled to a power source for supplying power to the power supply line and a controller configured to control the operation of the heater matrix. The master connection bridge includes a circuit configured to control the operation of at least one slave connection bridge based on a control signal received from the controller.

[0028] According to some embodiments, the substrate is a sheet of building or decorative material comprising one or more layers of fiber-based materials such as paper, cardboard, glass fiber, carbon fiber, textiles, fabrics made of any such fiber-based material, polymer fibers, fiber-reinforced materials, laminates such as high-pressure laminates, glass fiber composites, polymer materials, polymer films, concrete, and inorganic materials such as ceramics.

[0029] According to some embodiments, the substrate layer between the heater pixel's resistive pattern and the front surface of the substrate is less than 3 mm, preferably less than 2 mm, and most preferably less than 1 mm.

[0030] According to a second aspect, a method is provided for manufacturing a heater matrix comprising a plurality of heater pixels and electrical connections for the heater pixels. The method includes the step of patterning a layer of a first conductive material on a substrate or on a first sacrificial carrier to form a plurality of heater pixels. The patterned layer of the first conductive material has a first resistivity. The method includes the step of patterning a layer of a second conductive material on a substrate or on a first sacrificial carrier or on a second sacrificial carrier to form electrical wiring. The patterned layer of the second conductive material has a second resistivity lower than the first resistivity. If a first sacrificial carrier and / or first and second sacrificial carriers are used for patterning, the method includes the step of transferring the plurality of heater pixels and / or electrical wiring from their respective sacrificial carriers to a substrate. The method further includes the step of mounting a plurality of connection bridges on the substrate. The mounting step includes electrically connecting the plurality of heater pixels to the electrical wiring via the connection bridges.

[0031] According to some embodiments, the step of installing a plurality of connection bridges includes applying solder paste to the heater pixels and electrical wiring in place and / or to the plurality of connection bridges, arranging the plurality of connection bridges on the heater pixels and electrical wiring, and soldering the heater matrix by temporarily heating the heater matrix to melt the solder paste, thereby electrically connecting the heater pixels to the electrical wiring via the connection bridges.

[0032] According to some embodiments, the step of mounting a plurality of connection bridges on a substrate includes mounting the connection bridges on the substrate by mechanical-electrical connectors such as crimp connectors for electrically connecting heater pixels to electrical wiring via the plurality of connection bridges.

[0033] According to some embodiments, the step of mounting a plurality of connection bridges on a substrate includes mounting the connection bridges on the substrate with an anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) for electrically connecting the heater pixels to electrical wiring via the plurality of connection bridges.

[0034] According to some embodiments, the step of mounting a plurality of connection bridges on a substrate includes mounting the connection bridges on the substrate by an isotropic conductive film (ICF) or isotropic conductive adhesive (ICA) for electrically connecting the heater pixels to electrical wiring via the plurality of connection bridges.

[0035] According to some embodiments, the step of mounting a plurality of connection bridges onto a substrate further includes applying an adhesive to the connection bridges and / or the substrate to fix the connection bridges to the substrate.

[0036] This invention has the advantage of avoiding hot spots in contact areas, which would normally pose safety problems. This solution also avoids parasitic heating of electrical wiring, especially when powering one or more heater pixels of a heater matrix using safe voltages and high currents.

[0037] The present invention will be described in more detail below with reference to the attached drawings, in relation to preferred embodiments. [Brief explanation of the drawing]

[0038] [Figure 1] This is a diagram showing a room equipped with a heater matrix. [Figure 2] This figure shows the back surface of an exemplary heater matrix supported by a substrate. [Figure 3] This is a schematic diagram showing a cross-section of the electrical connection between the heater pixel and the power supply line. [Figure 4] This figure shows a heater matrix according to some examples. [Figure 5] This figure shows a heater matrix according to some examples. [Figure 6] This diagram shows a method for manufacturing a heater matrix. [Figure 7] This diagram shows a method for manufacturing a heater matrix. [Figure 8] This diagram shows a method for manufacturing a heater matrix. [Figure 9] This diagram shows the steps for attaching a connecting bridge by soldering. [Figure 10] This figure shows the steps for attaching a connecting bridge using an anisotropic conductive adhesive. [Modes for carrying out the invention]

[0039] In this context, "front" refers to the side of the substrate intended to face the inside of a room or other confined space. "Back" refers to the side of the substrate intended to face away from the room or other confined space.

[0040] The heater matrix 100 comprises a plurality of resistive heater elements, referred to herein as heater pixels 10. Each heater pixel 10 represents a cell of the heater matrix 100. The heater pixels 10 can have any size and / or shape and can be controlled individually or as a group.

[0041] The heater pixel 10 is supported by the substrate, either embedded within the substrate or provided on the surface of the substrate. In this context, the substrate refers to any suitable interior building material or decorative material sheet. The heater pixel 10 may be embedded between selected layers of various materials forming the substrate. The heater pixel 10 may be embedded within the substrate material layer.

[0042] In the example shown in Figure 1, the heater pixels 10 are provided on the walls and floor, respectively, and are embedded in or mounted on the surface of various substrate materials installed on the walls and floor. For example, the heater pixels 10 on the walls may be supported by any fiber-based material such as paper, cardboard, glass fiber, carbon fiber, textiles and fabrics made therefrom, polymer fibers and fiber-reinforced materials made with the help of them. Such materials may include laminates such as high-pressure laminates and glass fiber composite materials. The heater pixels can be integrated with polymer materials and films as well as inorganic materials such as concrete and ceramics. Preferably, the heater pixels are not visible in the room (space), in other words, they are hidden behind at least one or more visible surface layers of each substrate. In Figure 1, selective activation is illustrated by showing active heater pixels 10 as a pattern and inactive heater pixels 10 as white areas. In this context, selective activation means that any one or more individual heater pixels 10 or any one or more groups of heater pixels 10 can be activated separately from any other individual heater pixels 10 and / or groups of heater pixels. When activated, the heater pixels 10 generate a microclimate in their vicinity. By adjusting the power supplied to one or more active heater pixels, their temperature, and therefore the temperature of the generated microclimate, is controlled.

[0043] The heater pixels 10 may be controlled individually or in groups, so that they can be controlled to be inactive when they are in the same position as furniture 21 or rug 20, as shown in Figure 1. On the other hand, one or more heater pixels located next to furniture 21 where people spend a lot of time, such as an office desk, are preferably activated to create a comfortable local microclimate at a comfortable temperature. The heater pixels 10 can also be embedded in furniture. For example, a sofa or chair may have one or more heater pixels embedded in the upholstery fabric that covers the sofa.

[0044] Figure 2 is a simplified rear view of an exemplary heater matrix 100 supported by a substrate 19. This small exemplary heater matrix 100 can be mounted on any suitable building board, or other building materials such as laminate flooring, interior wall boards, wallpaper, wall panels or tiles, or fabrics such as upholstery.

[0045] Each heater pixel 10 comprises a resistive heater element patterned from a conductive material, preferably a metal such as Al, Ni, Cu, Fe, or Zn, or an alloy such as brass, bronze, or nickel silver, or a derivative thereof such as phosphor bronze, or carbon fiber. The conductive material may be applied in printed form. In such cases, inks made from silver, carbon, copper, or mixtures thereof may be used. According to a preferred embodiment, the conductive material for the resistive heater element of the heater pixel is brass. As is known in the art, the resistivity of brass is approximately twice that of silver and copper. Although aluminum is a suitable conductive material for this purpose, it presents some problems due to its incompatibility with common soldering materials and methods. The resistive heater element of the heater pixel is configured to be heated by the controllable supply of current. When the electrical coupling of the resistive heater element is not carried out by soldering, aluminum is a practical choice of conductive material.

[0046] As is known in the art, electrical resistivity ρ is, ρ = R * (l / A) It can be calculated as follows, where R is the electrical resistance of a uniform sample of the material, l is the length of the sample, and A is the cross-sectional area of ​​the sample.

[0047] In another embodiment, the resistivity of the resistive heater element and the electrical wiring is designed by adjusting the cross-sectional area and / or length of the respective patterns. In some embodiments, both the resistive heater element and the electrical wiring of the heater pixel are made of copper. Preferably, the resistivity of the resistive heater element of the heater pixel is considerably higher than the resistivity of the electrical wiring. For example, the resistivity of the resistive heater element may be at least twice or at least three times higher than the resistivity of the electrical wiring.

[0048] Furthermore, by combining material selection and pattern design, resistive heater elements and electrical wiring with mutually different resistivity can be designed as desired.

[0049] The conductive material layer of the heater pixel 10 is thin. In this context, a thin layer of conductive material refers to a layer of approximately 0.5 to 50 micrometers. In some embodiments, the conductive material layer has a thickness of 10 to 30 micrometers. In some embodiments, the conductive material layer has a thickness of 10 to 20 micrometers. The resistive heater element may be manufactured by printing, or by using conversion techniques such as die-cutting and lamination known in the packaging industry, or by using other roll-to-roll manufacturing techniques such as laser patterning, etching, and dry etching, all of which enable the production of a thin, patterned layer of conductive material. The thin layer of conductive material makes the heater pixel invisible even if the substrate or layer of the substrate on the front side of the heater pixel, in other words, the layer between the heater pixel and the front side of the substrate, is thin.

[0050] In Figure 2, the electrical connections for the multiple resistive heater elements of the heater pixel 10 are provided by connection bridges 35, 36 electrically connected to the electrical wiring 30. The electrical wiring 30 comprises power supply lines including at least one ground supply line and at least one operating voltage supply line. Furthermore, the electrical wiring 30 preferably provides data communication means to facilitate individual control of each heater pixel 10. As is known in the art, data communication may be performed via various types of wired communication. For example, the electrical wiring 30 may be configured to provide data communication via dedicated data communication lines or buses, or data communication may be carried by power supply lines. The connection bridges 35, 36 are provided with circuits for controlling the power supply to the heater pixels 10, such as switching the power on / off and / or controlling the amount of power supplied to each heater pixel 10. The electrical wiring 30 may comprise separate power lines and data lines, one or more buses carrying both power and data, or a combination of power supply lines and data buses. The electrical wiring 30 is further coupled directly or indirectly to a power supply (not shown) and a controller. According to some embodiments, the electrical wiring 30 is coupled to the power supply and / or controller. According to some embodiments, at least one connection bridge 36 is coupled to the power supply and / or controller by wire 33. Wire 33 can also carry data communications. According to some embodiments, data is wirelessly transmitted between a wireless communication circuit provided in the connection bridge 36 and an external controller (not shown), such as a wireless remote controller or a wireless communication device such as a mobile phone or tablet computer with a remote control application.

[0051] Similar to the resistive pattern of the heater pixel 10, the electrical wiring 30 is also made of a conductive material, and according to some embodiments, the electrical wiring may be printed, manufactured using conversion techniques known in the printing and packaging industry such as die-cutting or kiss-cutting or laser patterning, or manufactured using conventional electronic equipment manufacturing techniques such as etching and dry etching, or laminated. The conductive material of the electrical wiring 30 may be a metal such as Al, Ni, Cu, Fe, Zn, or an alloy such as brass, bronze, nickel silver, or a derivative thereof such as phosphor bronze. The conductive material may also be applied in a printed form. In such cases, an ink made from silver, carbon, copper, or a mixture thereof may be used. According to embodiments of the present invention, the conductive material used for the electrical wiring 30 is selected such that the conductivity of the electrical wiring 30 is better than the conductivity of the resistive heater element of the heater pixel 10, so that the electrical wiring 30 does not overheat significantly when the heater pixel 10 is active.

[0052] Similar to the heater pixels 10, the conductive material layer of the electrical wiring 30 is also thin. In this context, a thin layer of conductive material refers to a layer of about 0.5 to 50 micrometers. In some embodiments, the thin layer of conductive material has a thickness of 10 to 30 micrometers. In some embodiments, the thin layer of conductive material has a thickness of 10 to 20 micrometers. A thin layer of conductive material facilitates the concealment of the electrical wiring, even if the substrate or layer of the substrate between the electrical wiring and the front surface of the substrate is also thin. In this context, the substrate or layer of the substrate is considered thin if the total thickness of the substrate is 3 mm or less, preferably 2 mm or less, and most preferably 1 mm or less. Preferably, the electrical wiring 30 is laid on or between layers of the same substrate 19 as the heater pixels 10. However, this is not necessary because the electrical wiring 30 is not intended to produce a heating effect toward the space heated by the heater matrix.

[0053] According to some embodiments, the resistance of individual heater pixels 10 is 12 to 48 Ω, preferably 24 Ω, and the operating voltage is in the range of 12 to 48 V, depending on the desired heating power and resistance. According to some embodiments, there are two types of connection bridges 35, 36. The first connection bridge 36 is coupled to the wiring 33 and may include a circuit that controls the operation of multiple second connection bridges 35, while the second connection bridge 35 includes only a circuit that controls the operation of each heater pixel 10 to which it is directly coupled. Thus, the first connection bridge 36 may be called a master connection bridge, and the second connection bridge 35 may be called a slave connection bridge.

[0054] To facilitate the mass production of multiple heater pixels 10 and electrical wiring 30 on a substrate 19, a roll-to-roll manufacturing method can be applied. An exemplary method for manufacturing patterned resistive heating elements usable for heater pixels 10 is disclosed in International Patent Application WO2022 / 234189. Multiple heater pixels 10 are electrically connected to form a heater matrix 100. The electrical wiring 30 for the heater pixels 10 may be at least partially generated during the manufacturing process of the heater pixels 10, but the electrical wiring may be generated after the manufacturing process of the heater pixels 10.

[0055] The heater pixels 10 may be integrated into various interior building materials or decorative material sheets that can be used as the substrate 19 of the heater matrix 100. For example, the heater pixels 10 may be integrated into fabrics such as upholstery fabrics, curtains, blinds, decorative fabrics, and textiles, as well as laminates such as flooring laminates, wall boards, and fiber-reinforced composites such as glass fiber. Preferably, the conductive material pattern is positioned close to the outer surface of the substrate 19 such that only a thin layer of substrate material exists between the conductive material pattern of the heater pixels 10 and the front surface of the substrate 19. The front surface of the substrate refers to the surface intended to face the occupants of the room or other space, and the back surface refers to the surface away from the room or space. The thin layer of material reduces power loss in the material layer between the heater pixels and the space intended to be heated, and allows for a rapid temperature rise at the front surface of the substrate.

[0056] If the substrate 19 is sufficiently thin and does not cause significant heat loss when passing through the substrate material sheet, the heater pixels 10 and electrical wiring 30 can be patterned on the back of the substrate 19. This is beneficial because having the heater pixels 10 and electrical wiring 30 visible on the back of the substrate 19 facilitates electrical connection and therefore reduces manufacturing costs.

[0057] Heater pixels may be patterned on the front surface of the substrate, but typically, it is preferable that the front surface of the material sheet does not have visible heater pixels or other electrical elements that would be visible inside the space. On the other hand, heater pixels patterned on the front surface of some indoor building materials may be hidden behind standard tapestries, in which case the heater pixels may be present on the front surface of the substrate, as they will ultimately be hidden by the tapestry. However, care must be taken to ensure that the materials used for the tapestry or other covering, and the materials used to secure the tapestry over such exposed heater matrices, are compatible with the heater matrix and safe to use. Even when heater pixels are patterned on the front surface of the substrate, connecting bridges should not be placed on the front surface of the substrate, as they would essentially protrude from a flat front surface. Rather, connecting bridges should be placed on the back surface or embedded within or between the intermediate layers of the substrate.

[0058] Various substrate materials can be used for the heater matrix, but the selection of applicable substrate materials should be made with safety in mind. The reasonable temperature range at any point in the heater matrix during use must be significantly lower than the temperature at which the substrate material used poses a fire risk. Any fire-resistant substrate material can be used, and / or one or more substrate materials can be treated with flame retardants.

[0059] Figure 3 schematically shows a cross-section of the electrical connection between a heater pixel and electrical wiring in some embodiments. The drawing is not to scale.

[0060] The resistive patterns and electrical wiring 30 of the heater pixels 10 are located on the back of one or more surface layers of the substrate 19, such as the back of a thin substrate 19 or the surface layer of a laminate used for flooring. In this context, surface layers refer to layers such as abrasion layers, decorative layers and / or thin support layers, and the total thickness of the substrate 19 on the front side of the heater pixels 10 is preferably 2 mm or 3 mm or less. Any thicker core layers of the substrate should be located on the back side of the heater pixels 10, as illustrated in relation to Figure 4. Although not shown in Figure 3, the substrate 19 may contain multiple material layers. In this embodiment, a printed circuit board (PCB) is used as a connecting bridge 35, 36 between the heater pixels 10 and the electrical wiring 30. As is known to those skilled in the art, a PCB provides electrical connections between connecting pads for mounting electrical and electronic components and / or other elements of an electrical circuit onto the PCB.

[0061] The connecting bridges 35, 36 may be any known type of PCB, including, but not limited to, various known FR-type and CEM-type dielectric-based PCBs, ceramic PCBs, and any known flexible PCBs. Conventional PCBs are typically cost-effective but should preferably be used only with rigid carriers to avoid electrical disconnection due to substrate bending, while flexible PCBs are more expensive but allow the use of more flexible substrates. Preferably, the type of connecting bridges 35, 36 is selected so that they can be easily and reliably electrically connected to both the heater pixels 10 and the electrical wiring 30. The connecting bridges 35, 36 may be embedded in the material layer of the substrate, for example, an oriented strand board (OSB), high-density fiberboard (HDF), or medium-density fiberboard (MDF) may have recesses or grooves for the connecting bridges 35, 36 so that they are located on the front surface of the board where the heater pixels 10 act as the core layer. On the other hand, if the substrate is sufficiently thin and does not cause significant heat loss, the connecting bridge may be located on the back of the substrate. If the substrate 19 is flexible, it is preferable that the connecting bridges 35 and 36 are also flexible so that the solder connections between the connecting bridges 35 and 36 and the heater pixels 10 do not come loose due to bending of the substrate 19.

[0062] The solder 38 is preferably used to electrically and mechanically connect the connecting bridges 35, 36 to the resistive patterns of the heater pixels 10 and to the electrical wiring 30 provided on the substrate 19. In some embodiments, a low-temperature solder paste is preferred to avoid exposing the substrate to excessive heat during soldering. Known examples of such low-temperature solder pastes are tin and bismuth-based alloys.

[0063] Another possible connection method is to use lead-free and environmentally friendly adhesive interconnection systems, such as anisotropic conductive film (ACF) or isotropic conductive film (ICF), anisotropic conductive paste (ACP), or isotropic conductive adhesive (ICA). ACF and ACP are collectively called anisotropic conductive adhesive (ACA). Using ACA, ICF, or ICA, connection bridges 35, 36 can be coupled to the substrate and its electrical wiring 30. Compared to soldering, ACA, ICF, and ICA typically require a larger lateral connection area to safely carry the necessary current, which may exceed 20A, to power the heater matrix. ACA, ICF, or ICA may require additional mechanical support to ensure reliable mechanical and electrical connections.

[0064] The connecting bridges 35 and 36 may be further attached to the substrate 19 by adhesive 37 to further strengthen the mechanical connection between them. The adhesive 37 is preferably applied before soldering and serves to hold the connecting bridges 35 and 36 in place during soldering.

[0065] Figure 4 shows a heater matrix 100 according to some embodiments. For example, the substrate 19 in Figure 4 is a laminate, or the substrate 19 shown in Figure 4 includes two top layers of a laminate, forming its visible front surface. The top layers may be further attached to a core layer.

[0066] The resistive patterns and electrical wiring 30 of the heater pixels 10 of the heater matrix 100 are mounted on the back of these top layers of a relatively thin substrate 19. In this example, the substrate 19 includes two layers. The front of the substrate 19 is a decorative layer 19a, also called a printed layer or pattern layer, which determines the appearance of the substrate. The decorative layer 19a may include fabric.

[0067] In this example, a support layer 19b is located on the back of the decorative layer 19a. The type and material of the support layer 19b are selected based on the intended use of the substrate 19. For example, the support layer 19b may include one or more layers of paper. According to some embodiments, these paper layers of the support layer 19b are impregnated with liquid melamine.

[0068] Depending on the intended use of the substrate 19, the front surface of the decorative layer 19a may be further covered by an additional top layer, typically called an abrasion layer, which protects the decorative layer 19a from wear.

[0069] It is preferable that all layers on the front side of the heater pixel 10's resistive pattern are thin. For example, in laminated flooring, the thickness of the wear layer is typically less than 1 mm, preferably less than 0.5 mm. The thickness of the decorative layer 19a is less than 0.5 mm. The additional support layer 19b may be slightly thicker, but is typically in the range of 1 to 2 mm. Thus, the resistive pattern of the heater pixel 10 is positioned near the front of the substrate, i.e., preferably less than 1 mm, less than 2 mm, or less than 3 mm from the front. The smaller the total thickness of the substrate layers on the front side of the heater pixel 10, the faster the front of the substrate heats up when one or more heater pixels 10 are switched on. The front refers to the surface of the substrate that is intended to be placed facing the space heated by the heater matrix 100. In Figure 4, a portion of the support layer 19b and one of the heater pixels 10 are cut out for visualization. The shape and size of the heater pixels 10 can be varied, but their operation is easier to control if they are approximately the same size and / or have at least approximately the same resistance to each other. Electrical wiring 30 is mounted on the substrate between the heater pixels 10. Connecting bridges 35, 36 provide individually controllable electrical connections between the electrical wiring 30 and the heater pixels 10 to control the operation of the heater pixels 10. Connecting bridges 35, 36 are equipped with electronics for controlling the operation of the heater pixels 10.

[0070] If the laminated flooring is intended to have the decorative layer 19a and protective layer attached to a thicker core layer, the support layer 19b may be omitted.

[0071] Figure 5 shows a heater matrix 100 according to some embodiments. In addition to the decorative layer 19a and the support layer 19b, the substrate further includes a core layer 19c, sometimes called a substrate layer. The core layer 19c is selected according to the intended use of the substrate. The core layer 19c may be, for example, an oriented strand board (OSB), a fiberboard, a medium-density fiberboard (MDF), or a high-density fiberboard (HDF).

[0072] In some embodiments, the layered structure shown in Figure 4 is further attached to the core layer 19c so that the back side of the thin layer on the front side of the substrate, in other words, the side with the resistive patterns of the heater pixels 10, electrical wiring 30 and connecting bridges 35, 36, faces the thicker, more mechanically stable core layer 19c. In Figure 5, a portion of one of the support layer 19b, core layer 19c, and heater pixels 10 has been removed for visualization. The core layer 19c provides mechanical support to the substrate 19, while the heater pixels 10 remain separated from the front of the structure only by thin layers such as an optional support layer 19b and decorative layer 19a, and an optional wear layer. In some embodiments, only the decorative layer 19a and wear layer are provided on the front side of the heater pixels 10, and the desired mechanical support is provided on the back side of the heater pixels 10 by the core layer 19c.

[0073] In this example, the master connection bridges 36 coupled to the wiring 33 are exposed on the back side of the core layer 19c by openings 39 created by removing a portion of the core layer 19c located at the same position as each master connection bridge 36. Other slave connection bridges 35 (not shown) are preferably located in a plurality of recesses on the front side of the core layer 19c, at the same position as each slave connection bridge 35, so that these connection bridges 35 are hidden and not visible between the fairly thick core layer 19c and the front-side layers 19a and 19b of the substrate. The thickness of the core layer 19c may be several millimeters. For example, the total thickness of a typical laminate flooring is 6 to 12 mm, and the thickness of the core layer is about 5 to 11 mm. The laminate may include further layers, such as a backing layer (not shown), on the back of the core layer 19c. In such a case, the backing layer preferably has openings similar to those of the core layer 19c, exposing the master connection bridges 36 for electrical connection.

[0074] In this example, the master connection bridge 36 is coupled by wire 33 to a power supply for supplying power to the power supply lines. The master connection bridge 36 is also communicatively coupled to a controller configured to control the operation of the heater matrix. The master connection bridge includes circuitry configured to control the operation of at least one slave connection bridge based on control signals received from the controller. Wire 33 may be replaced at least partially by rear electrical wiring 30 or embedded in the circuit board 19.

[0075] Typical materials used in the core layer 19c of laminates and other building boards are thermally insulating; therefore, the resistive pattern of the heater pixels should not be placed on the back (behind) of such a layer in order to avoid a reduction in the heating effect achievable by the heater pixels 10. By placing the resistive pattern of the heater pixels 10 in front of the core layer 19c, the thickness of the layer between the front of the substrate and the heater pixels 10 can be minimized, while the heater pixels and electrical wiring are hidden and kept out of reach of occupants.

[0076] Figure 6 shows a method for manufacturing a heater matrix according to some embodiments.

[0077] In step 40, a thin layer of a first conductive material having a first resistivity is patterned on the surface of the substrate to form multiple resistive patterns for multiple heater pixels. The first conductive material has a first resistivity. According to some embodiments, the first conductive material may be brass, which is an alloy of copper and zinc.

[0078] In step 41, a thin layer of the second conductive material is patterned onto the surface of the substrate to form power supply lines. The second conductive material has a second resistivity that is lower than that of the first conductive material. According to some embodiments, the second conductive material is copper.

[0079] Steps 40 and 41 may be performed in any order, may be performed simultaneously, or one may be performed first.

[0080] In the optional step 55, adhesive is applied to the connecting bridge and / or the substrate to facilitate a good mechanical connection between the connecting bridge and the substrate.

[0081] In step 45, the connection bridge is mounted on the board so that the mechanical and desired electrical connections are made.

[0082] Figure 7 shows a method for manufacturing a heater matrix according to some embodiments.

[0083] In step 42, a thin layer of a first conductive material having a first resistivity is patterned onto the surface of the sacrificial carrier to form a plurality of heater pixels. The first conductive material has a first resistivity. According to some embodiments, the first conductive material may be brass, which is an alloy of copper and zinc.

[0084] In step 43, a thin layer of the second conductive material is patterned onto the surface of the second sacrificial carrier to form a power supply line. The second conductive material has a second resistivity that is lower than the first resistivity. According to some embodiments, the second conductive material is copper.

[0085] Steps 42 and 43 may be performed in any order, may be performed simultaneously, or one may be performed first.

[0086] In step 44, the heater pixel pattern is transferred from the first sacrificial carrier onto the substrate surface, and the power supply line pattern is transferred from the second sacrificial carrier onto the substrate surface.

[0087] In step 45, the connection bridge is mounted on the board so that the mechanical and desired electrical connections are made.

[0088] Figure 8 shows a method for manufacturing a heater matrix according to some embodiments.

[0089] In step 420, a thin layer of a first conductive material having a first resistivity is patterned on the surface of the sacrificial carrier to form a plurality of heater pixels, and a thin layer of a second conductive material is patterned on the surface of the sacrificial carrier to form power supply lines. The first conductive material has a first resistivity. According to some embodiments, the first conductive material may be brass, which is an alloy of copper and zinc. The second conductive material has a second resistivity that is lower than the first resistivity. According to some embodiments, the second conductive material is copper.

[0090] The patterning of heater pixels and power supply lines on the sacrificial carrier may be performed simultaneously, or one may be performed first.

[0091] Steps 44-45 are performed as already described above.

[0092] Several alternative methods can be used to install the connecting bridge in step 45.

[0093] Figure 9 shows the steps for attaching the connecting bridge by soldering, according to some embodiments.

[0094] In step 451, solder paste is applied to the heater pixels and electrical wiring in predetermined locations and / or to the connection pads of a plurality of connection bridges, such as a printed circuit board (PCB), which have defined electrical connections between the plurality of connection pads provided on the surface of the connection bridge.

[0095] The solder paste may be selected from any known type of solder paste. According to some embodiments, a low-temperature solder paste suitable for self-healing is used so that if a hot spot occurs in the heater matrix due to a poor electrical connection, the heat of such a hot spot remelts the solder, allowing the proper electrical connection to be re-established.

[0096] In step 452, the multiple connection bridges are positioned on the heater pixels and electrical wiring such that the areas where solder paste is provided are at the same locations as the desired contact points on each connection bridge and on the electrical wiring and heater pixels.

[0097] In step 453, soldering is performed using a known soldering method. As is known in the art, soldering involves at least temporarily heating and melting a solder paste so that an electrical connection is formed between the heater pixels, electrical wiring, and connecting bridges. Once the solder paste hardens, a mechanical connection is also formed between these elements. The maximum temperature allowed during the soldering stage must be within the permissible limits of all materials in the structure, including the substrate, which is considered to have the lowest permissible temperature range. If adhesive is applied in step 55, the adhesive further promotes a good mechanical connection between the connecting bridges and the substrate.

[0098] Figure 10 shows the steps for installing a connecting bridge by ACF or ACP according to some embodiments.

[0099] In step 451, ACF or ACP is applied to the heater pixels and electrical wiring in predetermined locations, and / or to the connection pads of the multiple connection bridges.

[0100] In step 452, the multiple connection bridges are arranged on the heater pixels and electrical wiring such that the areas where the ACF or ACP is provided are in the same position as the desired contacts on each connection bridge, thereby forming the desired electrical connection.

[0101] According to some embodiments, soldering is not used, but the desired electrical connection between the connecting bridge, heater pixels, and power supply lines is provided by mechanical-electrical connectors such as crimp connectors. For example, suitable wiring is provided with crimp connectors at its ends, which are mechanically attached to desired coupling pads provided on the substrate, for example, by metal spikes or screws that attach the crimp connectors to the substrate.

[0102] A combination of brass as the first conductive material and copper as the second conductive material is preferred in all of the embodiments described above. As is known, the conductivity of brass is only 28% of that of copper. Therefore, sufficient current flows to heat the resistive pattern, while the power supply lines that power the resistive pattern are not significantly heated. If a larger difference in conductivity is required, bronze can be used as the first conductive material together with copper as the second conductive material. Further alternative combinations of conductive materials with a suitable difference in conductivity for such purposes include zinc and copper, nickel and copper, and aluminum and copper.

[0103] As technology advances, it will be apparent to those skilled in the art that the basic concept of the present invention can be implemented in various ways. Therefore, the present invention and its embodiments are not limited to the examples described above, but can be modified within the scope of the claims.

Claims

1. A heater matrix comprising a plurality of heater pixels and electrical connections for the heater pixels, Each of the heater pixels is a resistive pattern attached to or embedded in the surface of the substrate, wherein the resistive pattern is made of a layer of a first conductive material and has a first resistivity. In a heater matrix, the electrical connection comprises electrical wiring attached to the surface of the substrate or embedded in the substrate, wherein the electrical wiring is made of a second conductive material, the electrical wiring has a second resistivity, and the second resistivity is lower than the first resistivity, The electrical connection comprises a plurality of connection bridges, each connection bridge providing an electrical connection between at least one heater pixel and the electrical wiring, and each connection bridge is electrically connected to the at least one heater pixel and the electrical wiring by soldering, a mechanical-electrical connector, an anisotropic conductive film (ACF), anisotropic conductive paste (ACP), an isotropic conductive film (ICF), and an isotropic conductive adhesive (ICA). Heater matrix.

2. The heater matrix according to claim 1, wherein the solder paste used for soldering is a low-temperature solder paste configured to self-repair electrical connections via the solder paste when hot spots occur due to loosening of connections.

3. The heater matrix according to claim 1 or 2, wherein the plurality of connecting bridges are further fixed to the substrate by adhesive.

4. The heater matrix according to any one of claims 1 to 3, wherein the first conductive material is brass, bronze, zinc, nickel, or aluminum, and the second conductive material is copper.

5. The heater matrix according to any one of claims 1 to 4, wherein both the layer of the first conductive material and the layer of the second conductive material have a thickness of 0.5 to 50 micrometers, preferably 10 to 30 micrometers, and more preferably 10 to 20 micrometers.

6. The heater matrix according to any one of claims 1 to 5, wherein the electrical wiring comprises at least one power supply line and at least one ground supply line, and the electrical wiring further provides data connections, the data connections being carried by the at least one power supply line or by one or more dedicated data communication lines.

7. The heater matrix according to any one of claims 1 to 6, wherein the plurality of connection bridges comprises at least one master connection bridge and at least one slave connection bridge, the at least one master connection bridge is coupled to a power supply for supplying power to the power supply line and a controller configured to control the operation of the heater matrix, and the master connection bridge comprises a circuit configured to control the operation of the at least one slave connection bridge based on a control signal received from the controller.

8. The heater matrix according to any one of claims 1 to 7, wherein the substrate is a sheet of building material or decorative material comprising one or more layers of fiber-based materials such as paper, cardboard, glass fiber, carbon fiber, textile, fabric made of any such fiber-based material, polymer fiber, fiber-reinforced material, laminate such as high-pressure laminate, glass fiber composite, polymer material, polymer film, concrete, and inorganic material such as ceramic.

9. The heater matrix according to any one of claims 1 to 8, wherein the thickness of the substrate layer between the resistive pattern of the heater pixel and the front surface of the substrate is less than 3 mm, preferably less than 2 mm, and most preferably less than 1 mm.

10. A method for manufacturing a heater matrix comprising a plurality of heater pixels and electrical connections for the heater pixels, A step of patterning a layer of a first conductive material on a substrate or on a first sacrificial carrier in order to form a plurality of heater pixels, wherein the patterned layer of the first conductive material has a first resistivity, A step of patterning a layer of a second conductive material on the substrate or on the first sacrificial carrier or on the second sacrificial carrier in order to form an electrical wiring, wherein the patterned layer of the second conductive material has a second resistivity, and the second resistivity is lower than the first resistivity, When the first sacrificial carrier and / or the first and second sacrificial carriers are used for patterning, the steps include transferring the plurality of heater pixels and / or the electrical wiring from the respective sacrificial carriers to the substrate, In a method including, A step of attaching a plurality of connection bridges to the substrate, wherein the attaching step includes electrically connecting the plurality of heater pixels to the electrical wiring via the connection bridges, and the attaching step includes electrically connecting the connection bridges to at least one heater pixel and the electrical wiring by one of the following: soldering, mechanical-electrical connectors, anisotropic conductive film (ACF), anisotropic conductive paste (ACP), isotropic conductive film (ICF), and isotropic conductive adhesive (ICA). A method including the step of installing multiple connection bridges.

11. The step of attaching the plurality of connecting bridges is, The steps include applying solder paste to predetermined locations on the heater pixels and electrical wiring, and / or to a plurality of connection bridges, The steps include arranging the plurality of connection bridges on the heater pixels and electrical wiring, The steps include: temporarily heating the heater matrix to melt the solder paste, thereby soldering the heater matrix by electrically connecting the heater pixels to the electrical wiring via the connecting bridge; The method according to claim 10, including the method described in claim 10.

12. The step of attaching a plurality of connection bridges to the substrate is, A step of applying adhesive to the connecting bridge and / or the substrate to fix the connecting bridge to the substrate, The manufacturing method according to claim 10 or 11, further comprising:

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