An electrically conductive heating circuit integration method for a glass substrate

Abstract

The application discloses a conductive heating circuit integration method for a glass substrate, and particularly relates to the field of printed circuit integration, and aims to solve the problem that the existing conductive heating circuit is difficult to realize precise regulation and control in a non-uniform temperature field and adjacent tracks are prone to electromagnetic coupling interference; the application establishes the corresponding relationship between temperature and peak frequency by measuring the dielectric loss tangent of the glass substrate with frequency variation characteristics, divides multiple conductive heating areas based on the thermal equilibrium steady-state temperature distribution, maps the temperature of each area to a matching driving frequency, adjusts the development length and parallel spacing of the serpentine conductive tracks in the layout so that the self-resonant frequency is consistent with the matching driving frequency, rearranges the track positions according to the frequency difference and electromagnetic coupling coefficient of adjacent areas and sets the minimum spacing, and finally forms the heating circuit structure corresponding to the partition through printing and solidification, so that the multi-area collaborative and stable conductive heating control is realized.

Description

Technical Field

[0001] This invention relates to the field of printed cable integration technology, and more specifically, to a method for integrating conductive heating circuits for glass substrates. Background Technology

[0002] With the rapid development of flat panel display component applications, the demand for integrating conductive heating circuits on glass substrates is increasing. In practical applications, glass substrates often have complex, non-uniform thermal load environments, making it difficult for traditional uniform resistive heating circuits to achieve precise circuit integration and control for different areas. Furthermore, in multi-area heating designs, the spatial layout and electrical connections between conductive traces can introduce electromagnetic coupling problems. Especially when using AC or high-frequency drives, coupling responses may occur between adjacent traces, causing a shift in the expected heating power distribution and further exacerbating temperature field instability.

[0003] In addition, existing technologies mostly rely on empirical layout design, controlling the heating effect by simply adjusting the trace length or spacing. They lack a systematic utilization of the electrical properties and frequency response characteristics of the material itself, making it difficult to achieve stable and controllable zoned heating under complex temperature distribution conditions.

[0004] Therefore, how to construct a conductive heating circuit integrated scheme on a glass substrate that can combine the material frequency characteristics and spatial temperature distribution while also taking into account electromagnetic coupling suppression has become a technical problem that urgently needs to be solved in related fields. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, embodiments of the present invention provide a method for integrating conductive heating circuits for glass substrates to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for integrating a conductive heating circuit on a glass substrate includes the following steps: S1. Measure the set of curves showing the change of dielectric loss tangent as a function of frequency on the glass substrate to be integrated at a preset temperature point, extract the peak frequency of dielectric loss corresponding to each temperature, and establish the correspondence between temperature and peak frequency. S2. Establish a steady-state temperature distribution cloud map of the glass substrate surface under rated heating power, and divide it into multiple conductive heating regions with defined boundaries according to the isothermal interval; S3. Search for the correspondence between temperature and peak frequency using the representative temperature values ​​of each conductive heating area, and use the peak frequency as the matching drive frequency for the corresponding conductive heating area. S4. In the printed heating circuit layout, serpentine conductive traces are laid out for each conductive heating area. The extended length of the traces and the spacing of the parallel segments are adjusted to drive the intrinsic inductance of the traces in the conductive heating area and the self-resonant frequency formed by its distributed capacitance to the glass substrate to be equal to the matching drive frequency. S5. Calculate the frequency difference between the self-resonant frequencies of adjacent conductive heating regions, set the minimum parallel spacing threshold between the serpentine conductive traces of adjacent conductive heating regions based on the frequency difference, and rearrange the relative positions of the traces of each conductive heating region according to the minimum parallel spacing threshold. S6. Connect the traces of each conductive heating area in parallel to the same AC drive bus pair, print conductive paste on the surface of the glass substrate according to the layout and cure it to form a branch structure in which the coverage area of ​​each trace coincides with the boundary of the corresponding conductive heating area.

[0008] As a further aspect of the present invention, in step S1, establishing the correspondence between temperature and peak frequency specifically includes: The glass substrate to be integrated is sequentially heated to multiple preset temperature values ​​and kept at a constant temperature. During the constant temperature maintenance, an alternating electric field with continuously varying frequency is applied to the surface of the glass substrate, and the dielectric loss tangent measurement value at different frequency points is collected simultaneously to generate data curves of dielectric loss tangent versus frequency at different preset temperature values. For each preset temperature value, a peak search is performed on the data curve. The frequency point corresponding to the maximum value of the dielectric loss tangent is marked as the dielectric loss peak frequency under that preset temperature value, and a correspondence table between temperature and dielectric loss peak frequency is established.

[0009] As a further aspect of the present invention, in step S2, establishing the steady-state temperature distribution cloud map of the glass substrate surface specifically includes: A rated DC current is applied to the heating circuit printed on the surface of the glass substrate to be integrated, and this is continued until the temperature fluctuation amplitude at each temperature measuring point on the surface of the glass substrate is lower than the preset fluctuation threshold. The temperature data matrix of the entire field of view on the surface of the glass substrate is collected using infrared thermal imaging. Pixels in the temperature data matrix that are within the same temperature range are grouped into the same isothermal set, and the isothermal set is mapped into multiple closed isothermal curve boundaries according to the preset temperature interval. Extract the geometric contour coordinates of the region enclosed by the boundary of each isotherm curve, determine the region defined by the geometric contour coordinates as the corresponding conductive heating region, and record the boundary coordinates and average temperature value of each conductive heating region. Simultaneously, two conductive heating regions that share at least one boundary or whose shortest straight-line distance is less than a preset threshold within the plane of the glass substrate surface will be marked as adjacent conductive heating regions.

[0010] As a further aspect of the present invention, in step S3, using the peak frequency as the matching drive frequency for the corresponding conductive heating region specifically includes: Extract the average temperature value of each recorded conductive heating area and use the average temperature value as the representative temperature value of that conductive heating area. Traverse the table of temperature and dielectric loss peak frequency correspondence, retrieve each representative temperature value, obtain the dielectric loss peak frequency that has a mapping relationship with the representative temperature value, assign the obtained dielectric loss peak frequency to the corresponding conductive heating region, use it as the matching driving frequency of the conductive heating region, and attach it to the boundary coordinates of the conductive heating region.

[0011] As a further aspect of the present invention, in step S4, adjusting the unfolded length of the trace and the spacing between parallel line segments specifically includes: In the printed heating circuit layout, the matching drive frequency is extracted and stored along with the boundary coordinates of each conductive heating area. The unfolded length of the trace and the spacing between adjacent parallel segments are used as adjustment variables. The unfolded length of the trace controls the intrinsic inductance value of the trace, and the parallel spacing controls the distributed capacitance value of the trace to the glass substrate. The corresponding self-resonant frequency is calculated based on the adjusted inductance and capacitance values. The adjustment ends when the self-resonant frequency falls within the allowable deviation range of the matching drive frequency of the current conductive heating area. Within the geometric range defined by the boundary coordinates of each conductive heating area, the centerline trajectory of the serpentine conductive trace is laid out according to the adjusted total length of the trace and the spacing between adjacent parallel line segments.

[0012] As a further aspect of the present invention, in step S5, rearranging the relative positions of the traces in each conductive heating region specifically includes: Extract the self-resonant frequency values ​​of the serpentine conductive traces in each conductive heating area, subtract the absolute values ​​of the self-resonant frequencies of adjacent conductive heating areas to obtain the frequency difference value, and calculate the ratio of the frequency difference value to the smaller value among the adjacent self-resonant frequencies as the normalized frequency difference factor. When the normalized frequency difference factor is less than the set separation threshold, the current response amplitude of adjacent serpentine conductive traces at their corresponding self-resonant frequencies is calculated under different parallel line spacing conditions, and the electromagnetic coupling coefficient of adjacent serpentine conductive traces is obtained as a function of parallel line spacing. Based on the changing relationship, the critical line spacing value that makes the electromagnetic coupling coefficient less than the preset coupling threshold is determined. The critical line spacing value is used as the minimum parallel spacing threshold of adjacent conductive heating regions. In the layout editing environment, the parallel line spacing of the serpentine conductive traces in the conductive heating region that is less than the minimum parallel spacing threshold is adjusted to the minimum parallel spacing threshold.

[0013] As a further aspect of the present invention, the electromagnetic coupling coefficient is specifically as follows: The current response amplitude of the serpentine conductive trace in each conductive heating region at its self-resonant frequency is taken as the main response amplitude, and the current response amplitude of the serpentine conductive trace in adjacent conductive heating regions at the same frequency is taken as the coupling response amplitude. The ratio of the coupling response amplitude to the main response amplitude is taken as the electromagnetic coupling coefficient.

[0014] As a further aspect of the present invention, in step S6, the branch structure in which the boundary of each trace coverage area coincides with the boundary of the corresponding conductive heating area specifically includes: The rearranged printed heating circuit layout is exported as a screen printing stencil. The cutout pattern of the screen printing stencil is transferred to the surface of the glass substrate to form a wet film pattern. After the coverage outline of each serpentine conductive line in the wet film pattern coincides with the boundary of the divided conductive heating area, a curing process is performed. Connecting terminals are led out from both ends of each solidified serpentine conductive trace, and all connecting terminals are respectively connected to the positive bus and negative bus of the same AC drive bus pair.

[0015] The technical effects and advantages of the present invention regarding the integration method of conductive heating circuit for glass substrates are as follows: This invention introduces the frequency characteristics of the dielectric loss tangent of the glass substrate to establish a correspondence between temperature distribution and frequency response, achieving a collaborative design from material properties to circuit structure. This enables each conductive heating region to form a stable self-resonant state under the matched driving frequency, thereby improving heating efficiency and enhancing the accuracy of temperature control. By dividing the conductive heating regions according to the steady-state temperature distribution and implementing targeted routing, it can effectively adapt to complex non-uniform thermal environments, avoiding problems such as local overheating or insufficient heating. Furthermore, by calculating the frequency difference between adjacent regions and introducing electromagnetic coupling coefficient constraints, the trace spacing is dynamically adjusted to suppress the coupling effect between adjacent conductive traces, reducing the impact of crosstalk on heating uniformity. At the same time, this invention, based on layout rearrangement and parameter inverse calculation, avoids the limitations of relying solely on experience for circuit design, giving the overall design process a clear physical basis and repeatability. Finally, circuit integration is completed through a unified printing and connection method, ensuring structural consistency while achieving multi-region collaborative operation. This improves system stability and reliability while enhancing the adaptability of the conductive heating circuit in complex application scenarios. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a conductive heating circuit integration method for a glass substrate according to the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 Figure 1 The present invention discloses a method for integrating a conductive heating circuit on a glass substrate, comprising the following steps: S1. Measure the set of curves showing the change of dielectric loss tangent as a function of frequency on the glass substrate to be integrated at a preset temperature point, extract the peak frequency of dielectric loss corresponding to each temperature, and establish the correspondence between temperature and peak frequency. S2. Establish a steady-state temperature distribution cloud map of the glass substrate surface under rated heating power, and divide it into multiple conductive heating regions with defined boundaries according to the isothermal interval; S3. Search for the correspondence between temperature and peak frequency using the representative temperature values ​​of each conductive heating area, and use the peak frequency as the matching drive frequency for the corresponding conductive heating area. S4. In the printed heating circuit layout, serpentine conductive traces are laid out for each conductive heating area. The extended length of the traces and the spacing of the parallel segments are adjusted to drive the intrinsic inductance of the traces in the conductive heating area and the self-resonant frequency formed by its distributed capacitance to the glass substrate to be equal to the matching drive frequency. S5. Calculate the frequency difference between the self-resonant frequencies of adjacent conductive heating regions, set the minimum parallel spacing threshold between the serpentine conductive traces of adjacent conductive heating regions based on the frequency difference, and rearrange the relative positions of the traces of each conductive heating region according to the minimum parallel spacing threshold. S6. Connect the traces of each conductive heating area in parallel to the same AC drive bus pair, print conductive paste on the surface of the glass substrate according to the layout and cure it to form a branch structure in which the coverage area of ​​each trace coincides with the boundary of the corresponding conductive heating area.

[0019] In step S1, a correspondence between temperature and peak frequency is established.

[0020] The integrated glass substrate undergoes a graded heating process, specifically employing a segmented isotropic control method for temperature loading. The glass substrate is placed on a heating platform with closed-loop temperature control capabilities. An embedded temperature sensing unit synchronously monitors the central and edge areas of the substrate, using the temperature reading from the central area as the primary control feedback for temperature adjustment. Preset temperature values ​​are determined using an evenly spaced distribution method; for example, within the range of room temperature to the target maximum operating temperature, temperature points are set every 10°C, with example values ​​including 30°C, 40°C, 50°C, 60°C, and 70°C. During the heating process, a step-by-step approximation method is used. When the deviation between the measured temperature at the current temperature point and the target temperature is less than ±0.5°C and the fluctuation range does not exceed 0.2°C within 120 seconds, the temperature point is considered to have reached a isotropic state, and the frequency scanning phase begins. During the isotropic maintenance period, an alternating electric field is applied to the surface of the glass substrate through electrodes. The electrodes employ a symmetrical planar electrode structure arranged on the upper and lower surfaces of the substrate to ensure uniform electric field distribution within the measurement area. The electrode material is a conductive silver paste sintered layer to ensure stable contact. The AC electric field frequency is continuously scanned to cover a predetermined frequency band, for example, from 1kHz to 10MHz, with point-by-point scanning. The scanning step size is segmented according to the frequency band: 100Hz for low frequencies, 1kHz for mid-frequency frequencies, and 10kHz for high frequencies, to balance measurement accuracy and efficiency. At each frequency point, the dielectric loss tangent is synchronously acquired using an impedance analysis module, and environmental noise interference is suppressed using phase-locked loop detection to ensure stable measurement results. To avoid transient errors introduced by frequency switching, sampling is performed after a 50ms delay after each frequency switch, ensuring that the electric field response reaches a stable state before data recording. For each temperature point, the entire frequency range is scanned, and the corresponding frequency and dielectric loss tangent are recorded in pairs to form a complete data sequence for that temperature point.

[0021] After collecting data at all preset temperature points, the data sequence corresponding to each temperature point is processed one by one to extract the peak frequency of the dielectric loss tangent. Specifically, the original data sequence is first smoothed using a moving average method with a fixed window width of 5 sampling points to eliminate local fluctuations and avoid false peaks caused by measurement noise. Then, the smoothed data curve is compared point by point, identifying positions where the current value is greater than the values ​​of its two adjacent sampling points as candidate peak points. For candidate peak points, to prevent small local fluctuations from being mistakenly identified as main peaks, an amplitude filtering rule is further introduced, retaining only candidate points within the top 10% of the largest values ​​in the current temperature data sequence as valid peak points. If multiple valid peak points exist, the frequency corresponding to the largest value is selected as the dielectric loss peak frequency for that temperature point. This filtering process is based on sequence comparison and sorting operations. After extracting the peak value for a single temperature point, the temperature value and its corresponding peak frequency are bound and recorded, stored in a list format, forming structured records such as "30℃ - corresponding frequency" and "40℃ - corresponding frequency". To ensure the continuity of the correspondence, the results for all temperature points are arranged in ascending order of temperature, and the frequency variation trend between adjacent temperature points is checked. When an abnormal deviation is found between the peak frequency of a certain temperature point and its adjacent points, the original data is reviewed and verified to eliminate erroneous records caused by measurement anomalies. Finally, a complete correspondence table is formed by combining all temperature points and their corresponding peak frequencies, and this table is stored with temperature as the index and peak frequency as the value.

[0022] In step S2, a cloud map of the steady-state temperature distribution on the surface of the glass substrate is established.

[0023] A rated DC current is applied to the glass substrate with the conductive heating circuit printed to obtain a stable surface temperature distribution. The rated DC current is set based on the heating circuit design parameters, such as calculating the target current value based on the total resistance of the conductive traces and the target heating power, and is controlled by a constant current power supply to ensure that the current remains constant during loading. To avoid local temperature anomalies caused by transient current surges, the current is applied gradually, increasing to the rated value over 3 to 5 seconds. The current is maintained after loading until the temperature at each measuring point on the glass substrate surface reaches a stable state. The measuring points are obtained by dividing the substrate surface into pre-calibrated infrared thermography areas, covering the entire surface area and evenly distributed in the center, edges, and corners. Temperature stability is determined using a time window statistical method, selecting a continuous 60-second window as the judgment window. The difference between the maximum and minimum temperature values ​​at any measuring point within this time window is taken as the fluctuation amplitude. The preset fluctuation threshold is determined by both equipment accuracy and process requirements; for example, 0.5℃ is selected as the threshold. When the fluctuation amplitude of all measuring points is lower than this value, the overall temperature field is considered to have entered a steady state. After steady-state determination, an infrared thermal imaging device is used to perform a full-field scan of the glass substrate surface. The thermal imager maintains a fixed distance from the substrate surface, for example, 300 mm, and temperature calibration is performed using a calibration plate to eliminate environmental reflection errors. The acquired infrared images are converted and processed to form a temperature data matrix, where each pixel corresponds to a specific temperature value. The matrix resolution is determined according to the specifications of the thermal imager.

[0024] After obtaining the temperature data matrix, it is partitioned to form conductive heating regions. First, the temperature values ​​of all pixels in the matrix are sorted and analyzed, and the temperature interval division rules are determined based on the temperature distribution range. The preset temperature interval is determined by evenly dividing the temperature range. For example, when the temperature range is 40℃ to 80℃, intervals can be divided in 5℃ increments, resulting in multiple intervals such as 40℃~45℃ and 45℃~50℃. This interval value is determined experimentally to ensure that the region division has both resolution and avoids excessive fragmentation. In specific processing, pixels falling within the same temperature interval in the temperature data matrix are grouped into isothermal sets, each set corresponding to one temperature interval. Subsequently, connectivity analysis is performed on each isothermal set, retaining only spatially continuous pixel regions and splitting non-contiguous regions into multiple subsets to ensure the spatial integrity of each region. For each subset, its outer contour is extracted using a boundary tracing method. Specifically, a pixel-by-pixel scanning method is used, recording the coordinates of boundary points clockwise from the edge pixels of the set to form a closed contour curve. The coordinate set of this contour curve represents the geometric boundary of the corresponding conductive heating region. To eliminate jagged edges at the boundaries, the contour curves are smoothed. For example, a three-point averaging method is used to correct the coordinates of continuous boundary points, making the contour smoother and more consistent with the actual distribution. After boundary extraction, the temperature values ​​of all pixels in each conductive heating area are averaged to obtain the average temperature value of that area, which is then stored together with its boundary coordinates to form a region boundary-average temperature correspondence data structure.

[0025] After dividing the conductive heating areas, the spatial relationships between these areas are determined to identify adjacent conductive heating areas. Specifically, the boundary coordinates of all conductive heating areas are first read, and each pair of areas is compared. For any two areas, it is first determined whether their boundaries overlap or have collinear segments. This involves checking if at least one continuous segment of points in the boundary coordinates of the two areas coincides spatially. If this condition is met, the two areas are directly marked as adjacent. If no shared boundary is detected, the shortest straight-line distance between the two areas is further calculated. The shortest distance is calculated by traversing all boundary point combinations of the two areas. Specifically, the Euclidean distance between each boundary point of area A and each boundary point of area B is calculated, and the minimum value is taken as the shortest distance between the two areas. A preset distance threshold is determined based on the layout design accuracy and the width of the conductive traces. For example, 2 mm can be selected as the threshold. When the shortest distance is less than this value, the two areas are considered to be spatially adjacent. After completing the above determination, all pairs of areas that meet any condition are marked as adjacent conductive heating areas, and an adjacency table is established. This table records the numbers of all adjacent areas corresponding to each area.

[0026] In step S3, the peak frequency is used as the matching drive frequency for the corresponding conductive heating region.

[0027] The average temperature value corresponding to each conductive heating area is read one by one and directly used as the representative temperature value of that area for identification and storage. Then, a pre-established table of temperature and dielectric loss peak frequency correspondence is called. This table is stored in an ordered array, with temperature values ​​arranged in ascending order and corresponding to their respective peak frequencies. During retrieval, interval positioning is performed for each representative temperature value. That is, the two temperature nodes closest to the representative temperature value are found in the table. When the representative temperature value is exactly the same as one of the node temperatures, the corresponding peak frequency is directly read. When the representative temperature value is between two nodes, the peak frequency corresponding to the closer node is selected as the retrieval result according to the principle of smaller temperature difference. For example, when the representative temperature is 52℃, and there are two nodes in the table, 50℃ and 55℃, the peak frequency corresponding to 50℃ is selected because the difference between 50℃ and 55℃ is 2℃ and the difference between 50℃ and 55℃ is 3℃. After frequency acquisition, the peak frequency is assigned to the corresponding conductive heating area and bound to the boundary coordinates of the area for storage, forming a composite data structure containing the area's geometric outline and the matching driving frequency. During the binding process, a unified data indexing method is used to attach the frequency value to the regional coordinate set, ensuring that the frequency information can be directly called without re-retrieval when the map is subsequently deployed.

[0028] In step S4, the unfolded length of the trace and the spacing between parallel line segments are adjusted.

[0029] The matching drive frequency value stored in the boundary coordinates of each conductive heating area is read one by one, and this frequency is used as the target frequency for the conductive trace structure design of that area. For each conductive heating area, the routing area is first determined according to its boundary geometry, and an initial serpentine routing framework is established within this area. The initial routing adopts an equally spaced parallel back-and-forth structure, and the length of each segment and the number of back-and-forths are determined according to the area size. For example, in areas with longer lengths, the number of back-and-forths is increased to improve the total routing length. The routing width is kept uniform in the layout, for example, set to 0.5 mm, to ensure manufacturing consistency and is not involved in subsequent adjustments. At this time, the total unfolded routing length and the spacing between adjacent parallel segments are used as two independent adjustment values. The total unfolded length is determined by the number of back-and-forth segments in the serpentine path and the length of each segment, while the parallel spacing is the distance between the center lines of two adjacent parallel traces. To ensure the controllability of the adjustment process, the initial values ​​are clearly set. For example, the initial unfolding length is set to 1.5 times the length of the longer side of the area, and the initial parallel spacing is set to 2 mm. These values ​​are selected based on conventional printing accuracy and electrical safety distance.

[0030] The intrinsic inductance and distributed capacitance of the traces are controlled by adjusting the trace unfolding length and parallel spacing, thereby achieving self-resonant frequency matching. The intrinsic inductance of the serpentine conductive trace is positively correlated with its total conductor length; that is, with the conductor width and thickness remaining constant, increasing the trace unfolding length directly increases the current path length, thereby increasing magnetic field energy accumulation and resulting in an increased inductance. Inductance can be increased by increasing the number of folds or lengthening individual segments; conversely, reducing the number of folds or shortening the path length decreases the inductance. Simultaneously, distributed capacitance is formed between the serpentine trace and the glass substrate, and electric field coupling also exists between adjacent parallel segments. The magnitude of this capacitance is inversely related to the parallel segment spacing; that is, the smaller the spacing, the stronger the electric field coupling per unit length, and the larger the total capacitance; increasing the spacing decreases the capacitance. Reducing the parallel spacing increases the distributed capacitance, while increasing the spacing decreases the capacitance. Based on the aforementioned inductance and capacitance adjustment relationship, the self-resonant frequency is calculated for each set of trace parameters. The self-resonant frequency is jointly determined by the inductance and capacitance. The principle is that the energy stored in the inductor and capacitor reaches a dynamic balance at a certain frequency, at which point the circuit exhibits a resonant state. Specifically, based on the periodic exchange relationship between the inductor and capacitor energy storage, the self-resonant frequency is determined according to the inverse relationship between the square roots of the inductance and capacitance. A correction coefficient is introduced based on the actual trace structure, considering, for example, the influence of conductive paste resistance loss and glass substrate dielectric loss on frequency fine-tuning. The adjustment process adopts a stepwise approximation method; that is, after each adjustment of the trace length or spacing, the corresponding frequency is recalculated and compared with the target matching drive frequency. The adjustment ends when the deviation between the calculated self-resonant frequency and the target frequency is less than a preset allowable range. This allowable range is set according to process requirements, for example, ±5% of the target frequency is taken as the tolerance range to balance design accuracy and manufacturing error.

[0031] After matching the routing parameters, the actual layout of the serpentine conductive trace centerline trajectory is carried out within the boundary coordinate limit of each conductive and heating area. In practice, the starting and ending points of the traces are first determined within the area boundary. These points are placed at the edge of the area with reserved connection terminal positions for subsequent electrical connections. Then, a serpentine path is generated based on the determined total unfolded length and parallel spacing parameters. The path generation adopts a segment-by-segment extension method: starting from the starting point, the first straight segment is laid along the long side of the area. Upon reaching the boundary, the path shifts inward according to the set spacing, and the next parallel segment is laid in the opposite direction. This process is repeated to form multiple parallel zigzag structures until the total length requirement is met. To ensure the path remains completely within the area boundary, collision detection is performed at each zigzag. If the path is about to exceed the boundary, the length of that segment is shortened to correct it, ensuring all traces remain within the legal range. Simultaneously, a rounded transition method is used to connect adjacent straight segments at path bends to avoid current concentration problems caused by sharp corner structures. After all paths are laid out, a comprehensive check is performed on the centerline of the traces to verify whether the deviation between the total length and the set value is within the allowable range, for example, the allowable error should be controlled within ±2%. If it exceeds the range, it is corrected by fine-tuning the length of the end segment. The final generated serpentine conductive trace centerline trajectory maintains a strict correspondence with the area boundary.

[0032] In step S5, the relative positions of the traces in each conductive heating area are rearranged.

[0033] The self-resonant frequency values ​​of the serpentine conductive traces corresponding to each conductive heating region are read one by one, and each pair of adjacent regions is combined according to the region adjacency table. For any pair of adjacent regions, the two corresponding self-resonant frequency values ​​are obtained, and the absolute difference between them is calculated as the frequency difference value of the region pair. To avoid the influence of frequency magnitude differences on the comparison results, this frequency difference value is further normalized by dividing the frequency difference value by the smaller self-resonant frequency in the pair of regions, thus obtaining a dimensionless normalized frequency difference factor. This normalization method ensures a uniform judgment standard across different frequency ranges. After the normalized frequency difference factor is calculated, the normalized frequency difference factors of all adjacent region pairs are statistically analyzed, and a separation threshold is determined based on design experience. This separation threshold is set using a fixed ratio method, for example, selecting 0.1 as the judgment boundary, that is, when the frequency difference between two regions is less than 10% of its smaller frequency, it is considered that there is a significant risk of overlap in the frequency response between the two regions. Subsequently, the normalized frequency difference factor of each pair of regions is compared with the threshold. When the normalized frequency difference factor is less than the separation threshold, the pair of regions is marked as a pair of regions with high electromagnetic coupling risk.

[0034] For regions marked as having high coupling risk, the relationship between the electromagnetic coupling coefficient and spacing was obtained under different parallel line spacing conditions. Multiple spacing samples were constructed for this region pair in the layout design environment. The spacing values ​​were varied step-by-step at fixed increments, for example, starting from 1 mm and increasing in 0.5 mm increments up to 5 mm, forming a discrete spacing sequence. For each spacing value, the remaining structural parameters of the serpentine conductive traces in the two regions remained unchanged; only the spacing between adjacent parallel line segments was adjusted, and the corresponding self-resonant frequency was applied as the excitation signal under this structure. The excitation method involved applying a sinusoidal AC voltage to both ends of the trace in the current region, while simultaneously measuring the current response at both ends of the traces in adjacent regions. The measurement process was achieved using a current sampling resistor in conjunction with oscilloscope measurement, and the current amplitude was read after the excitation stabilized. The current response amplitude of the current region at its self-resonant frequency was taken as the main response amplitude, and the current response amplitude of the adjacent region at the same frequency was read as the coupling response amplitude. The electromagnetic coupling coefficient was calculated by comparing the two. To ensure data stability, each spacing point was measured three times, and the average value was taken as the final result. Through the above method, a set of data points corresponding to the "spacing-coupling coefficient" is obtained. The data is then arranged in ascending order of spacing, and a continuous relationship curve of the coupling coefficient changing with spacing is established using curve fitting. This curve exhibits a monotonically decreasing trend, meaning the coupling coefficient decreases as the spacing increases. Based on the established relationship of coupling coefficient changes, the minimum parallel spacing threshold that meets the coupling control requirements is determined. A coupling coefficient control standard is set, determined using a relative amplitude ratio method. For example, the coupling response amplitude is controlled within 5% of the main response amplitude, corresponding to an electromagnetic coupling coefficient no greater than 0.05. This ratio is verified experimentally, and within this range, the coupling effect will not interfere with the heat distribution. Subsequently, the minimum spacing value that meets this condition is found in the obtained "spacing-coupling coefficient" relationship curve, i.e., the position where the coupling coefficient first falls below the set ratio is identified, and the corresponding spacing is used as the critical spacing value. If this position is located between two discrete sampling points, the precise spacing value is calculated using linear interpolation to improve the accuracy of the results. After determining the critical spacing, it is defined as the minimum parallel spacing threshold for this region pair. During the layout adjustment phase, the actual parallel line spacing between all pairs of regions in the current layout is checked one by one. When a spacing at a certain position is found to be less than a threshold, the position of one side of the trace is shifted by a fixed offset until the minimum spacing requirement is met. During the shifting process, the overall trace structure is kept continuous, and its unfolded length and foldback structure are not changed; only the spatial position is adjusted. After the spacing correction of all pairs of regions is completed, the layout is reviewed as a whole to confirm that all pairs of high-coupling-risk regions meet the spacing requirements.

[0035] In step S6, a branch structure is formed in which the boundaries of each trace coverage area and the corresponding conductive heating area coincide.

[0036] The printed circuit layout, with its routing rearranged and meeting the spacing constraints of each conductive heating area, is exported as screen printing stencil data. During the export process, the centerline trajectory of the serpentine conductive traces in the layout is converted into a closed graphic outline with actual linewidth. The linewidth value is consistent with the aforementioned layout design, for example, uniformly set to 0.5 mm, and the corners are rounded to avoid sharp corners that could lead to printing defects. This graphic data is then converted into a screen printing mask format, and a screen printing stencil is created. The stencil uses a stainless steel mesh combined with a photosensitive emulsion coating process to form a patterned, stencil structure. The mesh count is selected based on the particle size of the conductive paste; for example, a 325-mesh stencil is used to ensure printing accuracy. After stencil preparation, the glass substrate is pretreated. Plasma cleaning is used to remove surface organic contaminants, and the substrate is heated to 60°C in a constant-temperature oven and held for 10 minutes to remove surface moisture, thereby improving paste adhesion. The conductive paste is then evenly coated onto the screen surface. A squeegee is used to transfer the paste through the cutouts on the screen to the glass substrate, forming a wet film pattern. The squeegee speed is controlled at 50 mm / s, and the squeegee pressure is maintained at 0.3 MPa to ensure sufficient paste filling and sharp edges. After printing, the wet film pattern is visually and microscopically inspected to confirm that all serpentine lines are complete and aligned with the screen. Figure 1 Specifically, check whether the edges of the traces are consistent with the boundary coordinates of the conductive heating area. If any local offset is found to exceed the printing tolerance range, such as an offset greater than 0.1 mm, the printing is directly deemed unqualified and reprinted. After confirming that the graphic meets the layout requirements, the glass substrate is sent to a curing oven for curing. The curing temperature is set according to the characteristics of the paste, for example, holding at 150℃ for 30 minutes to allow the organic solvent in the conductive paste to completely evaporate and complete the sintering of conductive particles, forming a stable conductive trace structure. After curing, allow it to cool naturally to room temperature, and then check the trace outline again to ensure that the final conductive trace coverage area is consistent with the boundary of the conductive heating area designed in the original specifications.

[0037] Terminal lead-out and electrical connection processing are performed on the cured serpentine conductive traces. Terminals are constructed in the pre-reserved connection areas at the start and end points of each serpentine conductive trace. These areas are pre-expanded during the layout design phase to form solder pads, for example, with an area of ​​2 mm x 2 mm, to facilitate subsequent connection operations. Conductive copper foil or silver-plated copper sheets are used as terminal materials, bonded and fixed with conductive silver adhesive. After applying the silver adhesive, the terminals are pressed onto the pad areas and cured under heat for 15 minutes to complete the bonding. After completing the terminal lead-out of each trace, the terminals in all conductive and heat-generating areas are uniformly routed and organized, with all starting terminals grouped into one group and ending terminals grouped into another. Then, AC drive bus pairs are set up, with the positive and negative buses formed using copper busbars or thick-film conductors and fixed to the edge of the glass substrate. All starting terminals are connected to the positive busbar via wires, and all ending terminals are connected to the negative busbar via wires. High-temperature resistant insulated wires are used, with a cross-sectional area of, for example, 0.5 square millimeters to meet the current carrying capacity. During the connection process, spot welding or conductive adhesive is used to fix the connection points, and continuity testing is performed after the connection is completed to ensure that all wiring is correctly connected in parallel to the busbar. To prevent mechanical stress damage to the connection area during subsequent use, an insulating protective adhesive is applied to the terminal and wire connection areas and cured for 20 minutes to form a protective layer. The final connection structure enables parallel connection of wiring in all conductive and heat-generating areas, allowing each area to operate synchronously under AC drive busbar power supply, and ensuring stable electrical contact and mechanical strength at each connection point.

[0038] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. The semiconductor medium can be a solid-state drive.

[0039] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0040] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0041] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0042] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0043] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0044] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0045] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0046] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for integrating a conductive heating circuit on a glass substrate, characterized in that, Includes the following steps: S1. Measure the set of curves showing the change of dielectric loss tangent as a function of frequency on the glass substrate to be integrated at a preset temperature point, extract the peak frequency of dielectric loss corresponding to each temperature, and establish the correspondence between temperature and peak frequency. S2. Establish a steady-state temperature distribution cloud map of the glass substrate surface under rated heating power, and divide it into multiple conductive heating regions with defined boundaries according to the isothermal interval; S3. Search for the correspondence between temperature and peak frequency using the representative temperature values ​​of each conductive heating area, and use the peak frequency as the matching drive frequency for the corresponding conductive heating area. S4. In the printed heating circuit layout, serpentine conductive traces are laid out for each conductive heating area. The extended length of the traces and the spacing of the parallel segments are adjusted to drive the intrinsic inductance of the traces in the conductive heating area and the self-resonant frequency formed by its distributed capacitance to the glass substrate to be equal to the matching drive frequency. S5. Calculate the frequency difference between the self-resonant frequencies of adjacent conductive heating regions, set the minimum parallel spacing threshold between the serpentine conductive traces of adjacent conductive heating regions based on the frequency difference, and rearrange the relative positions of the traces of each conductive heating region according to the minimum parallel spacing threshold. S6. Connect the traces of each conductive heating area in parallel to the same AC drive bus pair, print conductive paste on the surface of the glass substrate according to the layout and cure it to form a branch structure in which the coverage area of ​​each trace coincides with the boundary of the corresponding conductive heating area.

2. The method for integrating a conductive heating circuit for a glass substrate according to claim 1, characterized in that, In step S1, establishing the correspondence between temperature and peak frequency specifically includes: The glass substrate to be integrated is sequentially heated to multiple preset temperature values ​​and kept at a constant temperature. During the constant temperature maintenance, an alternating electric field with continuously varying frequency is applied to the surface of the glass substrate, and the dielectric loss tangent measurement value at different frequency points is collected simultaneously to generate data curves of dielectric loss tangent versus frequency at different preset temperature values. For each preset temperature value, a peak search is performed on the data curve. The frequency point corresponding to the maximum value of the dielectric loss tangent is marked as the dielectric loss peak frequency under that preset temperature value, and a correspondence table between temperature and dielectric loss peak frequency is established.

3. The method for integrating a conductive heating circuit for a glass substrate according to claim 1, characterized in that, In step S2, establishing the steady-state temperature distribution cloud map of the glass substrate surface thermal equilibrium specifically includes: A rated DC current is applied to the heating circuit printed on the surface of the glass substrate to be integrated, and this is continued until the temperature fluctuation amplitude at each temperature measuring point on the surface of the glass substrate is lower than the preset fluctuation threshold. The temperature data matrix of the entire field of view on the surface of the glass substrate is collected using infrared thermal imaging. Pixels in the temperature data matrix that are within the same temperature range are grouped into the same isothermal set, and the isothermal set is mapped into multiple closed isothermal curve boundaries according to the preset temperature interval. Extract the geometric contour coordinates of the region enclosed by the boundary of each isotherm curve, determine the region defined by the geometric contour coordinates as the corresponding conductive heating region, and record the boundary coordinates and average temperature value of each conductive heating region. At the same time, two conductive heating areas that share at least one boundary or whose shortest straight-line distance is less than a preset threshold within the plane of the glass substrate surface will be marked as adjacent conductive heating areas.

4. The method for integrating a conductive heating circuit for a glass substrate according to claim 1, characterized in that, In step S3, using the peak frequency as the matching drive frequency for the corresponding conductive heating region specifically includes: Extract the average temperature value of each recorded conductive heating area and use the average temperature value as the representative temperature value of that conductive heating area. Traverse the table of temperature and dielectric loss peak frequency correspondence, retrieve each representative temperature value, obtain the dielectric loss peak frequency that has a mapping relationship with the representative temperature value, assign the obtained dielectric loss peak frequency to the corresponding conductive heating region, use it as the matching driving frequency of the conductive heating region, and attach it to the boundary coordinates of the conductive heating region.

5. The method for integrating a conductive heating circuit for a glass substrate according to claim 1, characterized in that, In step S4, adjusting the unfolded length of the trace and the spacing between parallel line segments specifically includes: In the printed heating circuit layout, the matching drive frequency is extracted and stored along with the boundary coordinates of each conductive heating area. The unfolded length of the trace and the spacing between adjacent parallel segments are used as adjustment variables. The unfolded length of the trace controls the intrinsic inductance value of the trace, and the parallel spacing controls the distributed capacitance value of the trace to the glass substrate. The corresponding self-resonant frequency is calculated based on the adjusted inductance and capacitance values. The adjustment ends when the self-resonant frequency falls within the allowable deviation range of the matching drive frequency of the current conductive heating area. Within the geometric range defined by the boundary coordinates of each conductive heating area, the centerline trajectory of the serpentine conductive trace is laid out according to the adjusted total length of the trace and the spacing between adjacent parallel line segments.

6. The method for integrating a conductive heating circuit for a glass substrate according to claim 1, characterized in that, In step S5, rearranging the relative positions of the traces in each conductive heating area specifically includes: Extract the self-resonant frequency values ​​of the serpentine conductive traces in each conductive heating area, subtract the absolute values ​​of the self-resonant frequencies of adjacent conductive heating areas to obtain the frequency difference value, and calculate the ratio of the frequency difference value to the smaller value among the adjacent self-resonant frequencies as the normalized frequency difference factor. When the normalized frequency difference factor is less than the set separation threshold, the current response amplitude of adjacent serpentine conductive traces at their corresponding self-resonant frequencies is calculated under different parallel line spacing conditions, and the electromagnetic coupling coefficient of adjacent serpentine conductive traces is obtained as a function of parallel line spacing. Based on the changing relationship, the critical line spacing value that makes the electromagnetic coupling coefficient less than the preset coupling threshold is obtained. The critical line spacing value is used as the minimum parallel spacing threshold of adjacent conductive heating regions. In the layout editing environment, the parallel line spacing of the serpentine conductive traces in the conductive heating region that is less than the minimum parallel spacing threshold is adjusted to the minimum parallel spacing threshold.

7. The method for integrating a conductive heating circuit for a glass substrate according to claim 6, characterized in that, The electromagnetic coupling coefficient is specifically: The current response amplitude of the serpentine conductive trace in each conductive heating region at its self-resonant frequency is taken as the main response amplitude, and the current response amplitude of the serpentine conductive trace in adjacent conductive heating regions at the same frequency is taken as the coupling response amplitude. The ratio of the coupling response amplitude to the main response amplitude is taken as the electromagnetic coupling coefficient.

8. The method for integrating a conductive heating circuit for a glass substrate according to claim 1, characterized in that, In step S6, the branch structure that forms the boundary between each trace coverage area and the corresponding conductive heating area specifically includes: The rearranged printed heating circuit layout is exported as a screen printing stencil. The cutout pattern of the screen printing stencil is transferred to the surface of the glass substrate to form a wet film pattern. After the coverage outline of each serpentine conductive line in the wet film pattern coincides with the boundary of the divided conductive heating area, a curing process is performed. Connecting terminals are led out from both ends of each solidified serpentine conductive trace, and all connecting terminals are respectively connected to the positive bus and negative bus of the same AC drive bus pair.

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