Automatic coating device and coating method for low-resistance thick-film resistor

Abstract

The invention relates to the technical field of low-resistance thick-film resistor coating, in particular to an automatic coating device and method for a low-resistance thick-film resistor, and the device comprises a support, a base, a coating head, a rotating assembly, a fixing mechanism, a sliding mechanism, a starting motor and a working plate; the support is installed on the ground, the base is installed on the support, the coating head is installed in the base, the rotating mechanism is installed on the base, the fixing mechanism is installed on the rotating mechanism, the sliding mechanism is installed in the fixing mechanism, and the starting motor is installed below the rotating mechanism. The working plate is mounted on the fixing mechanism; the motor is started to drive the rotating assembly to rotate, so that the control sliding rod is driven by the control sliding groove to move, and the sliding block is driven to contract inwards or expand outwards in the fixed rail.

Description

Technical Field

[0001] The invention relates to the technical field of coating low-resistance thick-film resistors, and in particular to an automatic coating device and a coating method for low-resistance thick-film resistors. Background Art

[0002] Low-resistance thick film resistors are a type of thick film resistor manufactured by a special process and designed to provide relatively low resistance values. Typical applications include high current scenarios such as power management, current detection, power distribution, and shunts. The key feature of low-resistance thick film resistors is that they are usually between 1 milliohm and tens of ohms. Suitable for high current scenarios such as power measurement, shunt circuits, etc. Maintain the stability of resistance value in harsh environments such as high temperature, humidity, and vibration. The optimized sintering process can reduce the temperature drift of the resistor. Use ceramic substrates or other high thermal conductivity materials to effectively improve the heat dissipation capacity. The low resistance design itself reduces heat dissipation. Different resistance ranges and performance requirements can be achieved through precise adjustment of conductive materials and sintering processes.

[0003] Screen printing is the most commonly used coating method, which can achieve high-precision conductive patterns. Spraying, spin coating or other coating methods can also be used, depending on production requirements. Sintering at a high temperature of 600-900°C forms a dense conductive film layer. The sintering temperature curve needs to be strictly controlled to avoid bubbles, cracks or uneven structures. Thick film resistors that require particularly precise resistance values ​​can be adjusted by laser trimming. The thick film resistor coating device is a key equipment for uniformly coating conductive slurry onto the substrate and is widely used in the field of electronic component manufacturing. The following is a detailed introduction to the coating device, including its composition, functions, and key technical points: Main components of thick film resistor coating deviceCoating method: Common coating methods include screen printing, spraying and spin coating. Different methods are suitable for different thickness and precision requirements. It has a constant temperature heating function to prevent the viscosity of the slurry from changing during operation. Equipped with a stirring device to maintain the uniformity of the slurry. The conductive slurry is evenly coated on the surface of the substrate by screen printing, spraying or other methods. Screen printing method: The slurry is transferred to the substrate through a mesh pattern, which is suitable for high-precision graphics. Spraying method: The conductive slurry is sprayed onto the substrate in an atomized form, which is suitable for covering large areas and non-planar substrates. The solvent on the surface of the coated substrate is quickly evaporated through a built-in heating table or infrared lamp module to facilitate subsequent sintering. The coated substrate is sent to the sintering equipment through a transmission system. Sintering is usually completed by a separate high-temperature furnace, but a preheating function may be included in the integrated equipment.

[0004] Existing automated coating devices and coating methods for low-resistance thick film resistors. If the substrate moves or tilts during the coating process, the conductive paste will be unevenly distributed, resulting in thickness differences. Especially when screen printing or spraying, it will cause too much paste to accumulate in some areas, while others will be insufficient. For fine patterns (such as grids or complex circuits), if the substrate is not fixed properly, the pattern may be blurred or deformed, affecting the resistor performance.

[0005] In view of the above situation, in order to overcome the above technical problems, the present invention designs an automatic coating device and coating method for low-resistance thick film resistors, which solve the above technical problems. Summary of the invention

[0006] The technical purpose to be achieved by the present invention is to design an automatic coating device and coating method for low-resistance thick film resistors, which can be basically clamped and fixed during the coating process to ensure that too much slurry is not accumulated in all areas during screen printing or spraying, thereby ensuring the integrity of the fine pattern.

[0007] In order to achieve the above technical objectives, the present invention provides the following technical solutions: An automatic coating device for low-resistance thick film resistors has a compact structure and comprehensive functions. It is mainly composed of a bracket, a base, a coating head, a rotating assembly, a fixing mechanism, a sliding mechanism, a starting motor and a working plate. The device is designed to achieve high-precision coating operations in the production process of low-resistance thick film resistors, while improving production efficiency and finished product quality.

[0008] The bracket is the main supporting structure of the device, installed on the ground, providing a solid support and a stable working platform for the whole machine. The base is fixed on the bracket to carry the core working components. The coating head is the key part of the coating device, located inside the base, and is used to evenly coat the conductive paste. The coating head is usually designed with precise flow control and multi-angle adjustment functions to ensure the uniformity and accuracy of the paste coating.

[0009] The rotating assembly is installed above the base and is responsible for realizing the rotation function of the device. The fixing mechanism is located above the rotating assembly and is used to fix the substrate and ensure the stability of the substrate during the coating process. The sliding mechanism is integrated inside the fixing mechanism and includes components such as control slide rods, slide grooves and sliders. The mechanism adjusts the positioning and clamping force of the substrate through the precise movement of the slider to adapt to the requirements of substrates of different sizes.

[0010] The starter motor is the driving core of the device. It is installed under the rotating component and provides power to drive the rotating component to rotate. The starter motor is connected to the control slide rod through the transmission mechanism, which can drive the slide rod to move along the slide groove. When the slide rod moves, the slider shrinks inward or expands outward in the fixed track, thereby adjusting the fixed state of the substrate. This design ensures high-precision positioning of the substrate and avoids quality problems caused by loose substrates during the coating process.

[0011] The work plate is mounted above the fixture mechanism and is where the substrate is actually placed. The work plate works in conjunction with the fixture mechanism to ensure that the substrate remains stable while coating and receives an even coating.

[0012] The overall design of the device fully considers the needs of automated production. Through the close cooperation of mechanical and electrical components, the high efficiency and precision of the low-resistance thick film resistor coating process are achieved, making it suitable for use in industrial mass production.

[0013] The rotating assembly is an important part of the device for realizing the positioning adjustment and coating of the substrate, and includes a rotating disk, a control slide and a rolling groove. The rotating disk is firmly mounted above the base, as the core of the entire assembly, and is used to provide rotation support and transmission foundation. The control slide is precisely opened on the surface of the rotating disk, and the controlled movement of the slide rod is realized through the guiding effect of the slide. The design shape and size of the slide are optimized to ensure that the slide rod has high stability and smoothness during the sliding process, so as to accurately control the movement trajectory of the slider. In addition, the rolling groove is located on the inner side of the control slide, as an auxiliary structure, to provide further guidance and stable support for the slide rod, while reducing friction and movement resistance. Balls or other low-friction materials may be set in the rolling groove to further improve the movement efficiency and accuracy of the sliding assembly. Through the synergistic effect of the rotating disk, the control slide and the rolling groove, the assembly can effectively control the movement trajectory of the slider and ensure the accuracy of the substrate positioning and coating operation.

[0014] The control chute is designed to be arc-shaped, presenting a streamlined trajectory that can adapt to the circular motion requirements of the rotating component. This arc-shaped structure allows the slide bar to slide smoothly along the chute during movement, while achieving precise arc trajectory control. The arc design of the control chute is strictly calculated to ensure that the movement path of the slide bar meets the requirements of the coating process, especially when complex graphics are involved, and can provide high-precision motion guidance.

[0015] The rolling groove is located on the central axis of the inner side of the control slide and is the core guide part of the slide system. It is designed as a semicircular structure, which can perfectly match the slide bar or ball assembly. This design not only enhances the stability of the slide bar movement, but also effectively reduces the sliding friction, thereby improving the operating efficiency and service life of the entire device. The semicircular structure of the rolling groove also ensures that the slide bar maintains good guiding performance when moving at high speed, avoiding the positioning and coating accuracy of the substrate affected by offset or shaking. The coordinated design of the arc-shaped control slide and the semicircular rolling groove reflects the dual pursuit of movement stability and precision.

[0016] The fixing assembly consists of a fixing plate and a fixing track, which is an important structure for positioning and stabilizing the substrate. The fixing plate is firmly mounted above the base. As the core supporting part of the entire fixing assembly, its size and material are carefully designed to ensure that the device has sufficient load-bearing capacity and stability during operation. The fixing tracks are evenly distributed on the sides of the fixing plate in the form of a circular array. The arrangement of the circular tracks can adapt to substrates of different shapes and sizes, while providing multi-point support to avoid sliding or offset problems caused by single-point force. This design ensures the stability of the substrate during the coating process and reduces uneven coating caused by shaking. In addition, the circular track works in conjunction with other mechanisms to provide flexible positioning and fixing options for the substrate, which helps to improve coating accuracy and product consistency.

[0017] The fixed track structure is exquisitely designed, consisting of an upper notch, a lower notch, a translation slot and a stopper, which together realize the precise fixation and stable support function of the substrate. The upper notch is located at the top of the fixed track and is mainly used to accommodate the edge of the substrate or related clamping parts. Through its shape and depth design, it ensures that the substrate can be firmly embedded. The lower notch is located at the bottom of the fixed track and plays a role of balancing support, providing additional stability for the substrate to prevent shaking or falling off due to external forces during the coating process.

[0018] The translation slot is opened on the side of the lower notch and adopts a semicircular design. This structure not only improves the guiding performance of the sliding component, but also provides a smooth movement path when positioning the substrate, making it adaptable to substrates of different sizes or shapes. The limit block is installed on the side of the fixed track, and its trapezoidal design further optimizes the clamping effect of the substrate. The trapezoidal structure can form a larger contact surface when locking, thereby increasing friction and preventing any displacement or loosening of the substrate during high-precision coating.

[0019] This multi-slot combination design, coupled with precise guiding and smooth limiting functions, enables the fixed track to provide strong compatibility while ensuring the reliability of high-precision coating operations, providing a strong guarantee for the production quality of thick film resistors.

[0020] The sliding mechanism is an important component of the device, which is designed to achieve sliding accuracy and stability to ensure the precise positioning and fixation of the substrate during the coating process. The sliding mechanism includes a slider and a limit groove. The slider is installed inside the fixing mechanism as the main sliding unit, which carries the functions of sliding and adjustment. The limit grooves are opened on both sides of the slider to limit the movement range of the slider and prevent the slider from excessive displacement or deviation from the predetermined track during movement. The design of the limit groove ensures that the slider can remain within the specified track during the entire sliding process, effectively ensuring the stability and safety of the device.

[0021] In order to enhance the function of the sliding mechanism, the sliding mechanism also includes a connecting block, a fixing block and a placement slot. The connecting block is installed on the top of the slider and serves as a connecting part between the slider and other components, so that the entire mechanism can achieve coordinated movement. The fixing block is installed above the connecting block and is set in a triangular shape, which has better stability and support capacity. The placement slot in the fixing block is opened in the middle part, which is used to place and fix other components or substrates to ensure that the substrate does not move during the coating process, further enhancing the accuracy.

[0022] In addition, the sliding mechanism also includes a control slide bar, a rolling ball, a translation ring and a protection block, which work together to improve the efficiency and reliability of the sliding mechanism. The control slide bar is installed under the slider and is responsible for adjusting the movement direction and speed of the slider. The rolling ball is installed on the surface of the control slide bar as a rolling auxiliary component to effectively reduce friction and improve the smoothness of sliding. The translation ring is installed on the top of the rolling ball as a transition component connecting the slide bar and the rolling ball, further improving the stability of the movement. The protection block is installed under the control slide bar to prevent external interference or improper operation from affecting the sliding mechanism, ensuring the long-term stable operation of the sliding system.

[0023] This series of precision designs enables the sliding mechanism to play an important role in high-precision coating operations, ensuring accurate positioning and stable movement of the substrate, greatly improving the efficiency of the coating process and the quality of the finished product.

[0024] A coating method for low-resistance thick film resistors, in combination with the above-mentioned automated coating device, is efficient, accurate and reliable, and is suitable for mass production of low-resistance thick film resistors. The method ensures the uniformity of the coating and the stability of the resistance value through multi-step control, and the specific steps are as follows: S1: Select a conductive slurry suitable for low resistance and perform stirring and filtering.

[0025] In the coating process, it is very important to choose the right conductive paste. The paste of low-resistance thick film resistors usually contains conductive materials (such as silver, platinum or tungsten, etc.) and organic solvents. To ensure the stability of the paste and a good coating effect, first stir it thoroughly according to the formula to ensure the uniformity of the paste. Then, use a high-efficiency filter to filter the paste to remove impurities, large particles or other uneven substances that may exist in it, to ensure the purity of the paste and avoid defects in the coating process or affect the resistor performance.

[0026] S2: The substrate is placed and clamped, and sprayed layer by layer.

[0027] Place the treated substrate on the working plate and start the drive motor for precise positioning. The sliding mechanism will clamp the substrate to ensure that it remains stable and does not move during the entire coating process. According to the coating requirements, the slurry is evenly sprayed on the surface of the substrate by linear or spiral spraying, covering it layer by layer. The thickness of each layer is usually controlled between 10-25 microns. After spraying, it is dried for a short time by infrared lamp to remove the solvent and solidify each layer of coating to ensure the adhesion and uniformity of the next layer of coating. Through the repeated process of multi-layer spraying and drying, the required resistance value and coating thickness are gradually achieved.

[0028] S3: Low temperature drying.

[0029] After coating, the substrate needs to be dried at low temperature to remove the solvent and volatiles in the slurry. Usually, the drying temperature is set between 100-150°C and the drying time is 10-30 minutes. The specific time is adjusted according to the thickness of each layer of slurry and the volatility characteristics of the slurry. This process helps to accelerate the volatilization of the solvent, prevent the resistance performance from being affected by excessive solvent residue, and ensure the adhesion of the coating.

[0030] S4: sintering treatment.

[0031] The dried substrate will be sent to the sintering furnace for sintering. The sintering process can completely remove the organic matter in the coating, make the conductive material tightly combined, and improve the stability of the resistor. According to the different characteristics of the slurry used, set an appropriate sintering curve, generally using a heating rate of 1-5°C / min, and gradually heat to between 600-900°C. Keep at this temperature for 10-30 minutes to ensure that the coating is completely sintered. Then, slowly cool to room temperature, control the cooling rate, and avoid thermal stress caused by excessive temperature difference, which will cause cracks or fall off.

[0032] S5: Resistance test and fine-tuning.

[0033] After sintering, the resistance value is tested using a high-precision bridge or multimeter. Based on the deviation between the measured resistance value and the design target, if the resistance value does not meet the expectations, the coating is fine-tuned using laser trimming technology to ensure that the resistance value precisely meets the requirements. During this process, it is also necessary to check whether the coating is uniform and whether there are defects such as bubbles, cracks or particle accumulation. Only when the coating is perfect and the resistance value meets the standard can the product pass the test and enter the next production stage.

[0034] Through this series of rigorous coating, drying, sintering and fine-tuning steps, this method can ensure the high quality and consistency of low-resistance thick film resistors, which are suitable for applications with high requirements for accuracy and stability in industrial production.

[0035] The beneficial effects of the present invention are as follows: (1) The present invention solves the problem of clamping and fixing the substrate during the coating process through a carefully designed rotating assembly, fixing mechanism and sliding mechanism, ensuring high precision and consistency of the coating operation, avoiding slurry accumulation and pattern distortion, and thus improving the coating quality of the thick film resistor. The rotating assembly usually includes a rotating disk and a related drive device, which can accurately control the rotation of the substrate during the coating process. By controlling the rotation speed and direction of the rotating assembly, the substrate can be rotated evenly during the spraying or screen printing process, ensuring that the coating material can be evenly distributed on the surface of the substrate. The design of the rotating assembly ensures that the substrate surface is properly coated in multiple directions, avoiding the problem of unstable resistance caused by uneven coating in certain areas.

[0036] (2) The fixing mechanism is mainly responsible for firmly fixing the substrate during the coating process. Through precise clamping devices, the fixing mechanism ensures that the substrate will not be displaced or tilted during spraying or screen printing. In this way, even during the coating process, the substrate can always remain in a fixed position to avoid uneven coating or local accumulation due to changes in the position of the substrate. The fixing mechanism can provide sufficient pressure to fix the substrate through properly designed clamping components without excessively affecting the surface of the substrate to ensure that its shape is not deformed or damaged. The sliding mechanism usually includes sliders, limit grooves and other auxiliary components for precise movement and positioning of the substrate. Through the cooperation of the sliding mechanism, the substrate can be fine-tuned to ensure that all parts of the substrate receive the coating evenly during the coating process. Especially during screen printing or spraying, the sliding mechanism can help the substrate move within a specific range, so that the coating is covered on the substrate surface in a delicate manner, and avoid the problem of coating accumulation or shedding caused by loose substrate fixation.

[0037] (3) In coating operations that require fine patterns. The synergistic effect of the rotating component, the fixing mechanism and the sliding mechanism can ensure that the substrate is in a stable state during coating, reducing the possibility of uneven coating. The rotating component provides a uniform coating angle, the fixing mechanism ensures the stability of the substrate, and the sliding mechanism helps ensure that every part of the coating is evenly covered, avoiding uneven coating thickness or pattern distortion in certain areas due to excessive slurry accumulation. Through these designs, it can be effectively ensured that the fine pattern is not destroyed during the coating process, thereby improving the accuracy and stability of low-resistance thick film resistors. The present invention solves the problem of clamping and fixing during substrate coating by cleverly configuring the rotating component, the fixing mechanism and the sliding mechanism, ensuring the uniformity of the coating and the integrity of the pattern, and improving the production efficiency and product quality of low-resistance thick film resistors. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] The above and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the installation of the rotating assembly and other components of the present invention; Figure 3 It is a schematic diagram of the installation position of the working plate of the present invention; Figure 4 It is a schematic diagram of the structure of the rotating assembly of the present invention; Figure 5 It is a schematic diagram of the fixing mechanism structure of the present invention; Figure 6 The present invention Figure 5 A local enlarged schematic diagram in FIG. Figure 7 It is a schematic diagram of the structure of the sliding mechanism of the present invention; Figure 8 It is a flow chart of the method of the present invention.

[0040] In the figure: 1. bracket; 2. base; 3. coating head; 4. rotating assembly; 41. rotating disk; 42. control slide groove; 43. rolling groove; 5. fixing mechanism; 51. fixing disk; 52. fixing track; 521. upper notch; 522. lower notch; 523. translation groove; 524. limit block; 6. sliding mechanism; 61. slider; 62. limit groove; 63. connecting block; 64. fixing block; 65. placement groove; 66. control slide rod; 67. rolling ball; 68. translation ring; 69. protection block; 7. starting motor; 8. working plate. DETAILED DESCRIPTION

[0041] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0042] like Figure 1-8 As shown, an automatic coating device for low-resistance thick film resistors has a compact structure design and comprehensive functions, and is mainly composed of a bracket 11, a base 2, a coating head 3, a rotating component 4, a fixing mechanism 5, a sliding mechanism 6, a starting motor 7 and a working plate 8. The device is intended to achieve high-precision coating operations in the production process of low-resistance thick film resistors, while improving production efficiency and finished product quality.

[0043] The bracket 11 is the main support structure of the device, which is installed on the ground to provide a stable support and a stable working platform for the whole machine. The base 2 is fixed on the bracket 11 to carry the core working components. The coating head 3 is a key part of the coating device, located inside the base 2, and is used to evenly coat the conductive paste. The design of the coating head 3 usually has precise flow control and multi-angle adjustment functions to ensure the uniformity and accuracy of the paste coating.

[0044] The rotating assembly 4 is installed above the base 2 and is responsible for realizing the rotation function of the device. The fixing mechanism 5 is located above the rotating assembly 4 and is used to fix the substrate and ensure the stability of the substrate during the coating process. The sliding mechanism 6 is integrated inside the fixing mechanism 5 and includes components such as a control slide rod 66, a slide groove and a slider 61. The mechanism adjusts the positioning and clamping force of the substrate through the precise movement of the slider 61 to meet the requirements of substrates of different sizes.

[0045] The starter motor 7 is the driving core of the device, which is installed under the rotating assembly 4 and provides power to drive the rotating assembly 4 to rotate. The starter motor 7 is connected to the control slide bar 66 through a transmission mechanism, and can drive the slide bar to move along the slide groove. When the slide bar moves, the slider 61 shrinks inward or expands outward in the fixed track 52, thereby adjusting the fixed state of the substrate. This design ensures high-precision positioning of the substrate and avoids quality problems caused by loose substrates during the coating process.

[0046] The working plate 8 is installed above the fixing mechanism 5 and is the actual position where the substrate is placed. The working plate 8 cooperates with the fixing mechanism 5 to ensure that the substrate remains stable during coating and receives uniform coating.

[0047] The overall design of the device fully considers the needs of automated production. Through the close cooperation of mechanical and electrical components, the high efficiency and precision of the low-resistance thick film resistor coating process are achieved, making it suitable for use in industrial mass production.

[0048] like Figure 4 As shown, the rotating assembly 4 is an important part of the device for realizing the positioning adjustment and coating of the substrate, and includes a rotating disk 41, a control slide 42 and a rolling groove 43. The rotating disk 41 is firmly mounted above the base 2, as the core of the entire assembly, and is used to provide rotation support and transmission basis. The control slide 42 is precisely opened on the surface of the rotating disk 41, and the controlled movement of the slide rod is realized through the guiding effect of the slide. The design shape and size of the slide are optimized to ensure that the slide rod has high stability and smoothness during the sliding process, so as to accurately control the movement trajectory of the slider 61. In addition, the rolling groove 43 is located on the inner side of the control slide 42, as an auxiliary structure, to provide further guidance and stable support for the slide rod, while reducing friction and movement resistance. Balls or other low-friction materials may be arranged in the rolling groove 43 to further improve the movement efficiency and accuracy of the sliding assembly. Through the synergistic effect of the rotating disk 41, the control slide 42 and the rolling groove 43, the assembly can effectively control the movement trajectory of the slider 61 and ensure the accuracy of the substrate positioning and coating operation.

[0049] The control slide groove 42 is designed to be arc-shaped, presenting a streamlined trajectory, which can adapt to the circular motion requirements of the rotating component 4. This arc-shaped structure allows the slide rod to slide smoothly along the slide groove during movement, while achieving precise arc trajectory control. The arc design of the control slide groove 42 is strictly calculated to ensure that the movement path of the slide rod meets the requirements of the coating process, especially when complex pattern coating is involved, it can provide high-precision motion guidance.

[0050] The rolling groove 43 is located on the central axis of the inner side of the control slide groove 42 and is the core guiding part of the slide groove system. It is designed as a semicircular structure, which can perfectly match the slide rod or ball assembly. This design not only enhances the stability of the slide rod movement, but also effectively reduces the sliding friction, thereby improving the operating efficiency and service life of the entire device. The semicircular structure of the rolling groove 43 also ensures that the slide rod maintains good guiding performance when moving at high speed, avoiding the positioning and coating accuracy of the substrate affected by offset or shaking. The coordinated design of the arc-shaped control slide groove 42 and the semicircular rolling groove 43 reflects the dual pursuit of motion stability and accuracy.

[0051] like Figure 5As shown, the fixing mechanism 5 is composed of a fixing plate 51 and a fixing rail 52, which is an important structure for positioning and stabilizing the substrate. The fixing plate 51 is firmly mounted above the base 2. As the core supporting part of the entire fixing assembly, its size and material are carefully designed to ensure that the device has sufficient load-bearing capacity and stability during operation. The fixing rails 52 are evenly distributed on the side of the fixing plate 51 in the form of a circular array. The arrangement of the circular rails can adapt to substrates of different shapes and sizes, while providing multi-point support to avoid sliding or offset problems caused by single-point force. This design ensures the stability of the substrate during the coating process and reduces uneven coating caused by shaking. In addition, the circular rails work in synergy with other mechanisms to provide flexible positioning and fixing options for the substrate, which helps to improve coating accuracy and product consistency.

[0052] like Figure 6 As shown, the fixed track 52 is exquisitely designed in structure, and is composed of an upper notch 521, a lower notch 522, a translation groove 523 and a stopper 524, which together realize the precise fixation and stable support function of the substrate. The upper notch 521 is located at the top of the fixed track 52, and is mainly used to accommodate the edge of the substrate or related clamping parts. Through its shape and depth design, it ensures that the substrate can be firmly embedded. The lower notch 522 is located at the bottom of the fixed track 52, and plays a role of balancing support, providing additional stability for the substrate to prevent shaking or falling off due to external forces during the coating process.

[0053] The translation groove 523 is provided on the side of the lower notch 522 and is semicircular in design. Such a structure not only improves the guiding property of the sliding assembly, but also provides a smooth moving path when positioning the substrate, so that it can adapt to substrates of different sizes or shapes. The limit block 524 is installed on the side of the fixed track 52, and its trapezoidal design further optimizes the clamping effect of the substrate. The trapezoidal structure can form a larger contact surface when locked, thereby increasing the friction force and preventing any displacement or loosening of the substrate during the high-precision coating process.

[0054] This multi-slot combination design, coupled with precise guiding and stable limiting functions, enables the fixed track 52 to provide strong compatibility while ensuring the reliability of high-precision coating operations, providing a strong guarantee for the production quality of thick film resistors.

[0055] like Figure 7As shown, the sliding mechanism 6 is an important component of the device, which is designed to achieve sliding accuracy and stability to ensure the precise positioning and fixation of the substrate during the coating process. The sliding mechanism 6 includes a slider 61 and a limit groove 62. The slider 61 is installed inside the fixing mechanism 5 as the main sliding unit, which carries the functions of sliding and adjustment. The limit groove 62 is provided on both sides of the slider 61 to limit the range of motion of the slider 61, thereby preventing the slider 61 from excessive displacement or deviation from the predetermined track during the movement. The design of the limit groove 62 ensures that the slider 61 can remain within the specified track during the entire sliding process, effectively ensuring the stability and safety of the device.

[0056] In order to enhance the function of the sliding mechanism 6, the sliding mechanism 6 further includes a connecting block 63, a fixing block 64 and a placement groove 65. The connecting block 63 is mounted on the top of the slider 61 as a connecting part between the slider 61 and other components, so that the entire mechanism can achieve coordinated movement. The fixing block 64 is mounted above the connecting block 63 and is arranged in a triangular shape, which has better stability and support capacity. The placement groove 65 in the fixing block 64 is opened in the middle part for arranging and fixing other components or substrates to ensure that the substrate does not move during the coating process, further enhancing the accuracy.

[0057] In addition, the sliding mechanism 6 also includes a control slide bar 66, a rolling ball 67, a translation ring 68 and a protection block 69, which work together to improve the efficiency and reliability of the sliding mechanism. The control slide bar 66 is installed below the slider 61 and is responsible for adjusting the movement direction and speed of the slider 61. The rolling ball 67 is installed on the surface of the control slide bar 66 as a rolling auxiliary component to effectively reduce friction and improve the smoothness of sliding. The translation ring 68 is installed on the top of the rolling ball 67 as a transition component connecting the slide bar and the rolling ball 67, further improving the stability of the movement. The protection block 69 is installed below the control slide bar 66 to prevent external interference or improper operation from affecting the sliding mechanism 6, ensuring the long-term stable operation of the sliding system.

[0058] This series of precision designs enables the sliding mechanism 6 to play an important role in high-precision coating operations, ensuring accurate positioning and stable movement of the substrate, greatly improving the efficiency of the coating process and the quality of the finished product.

[0059] A coating method for low-resistance thick film resistors, in combination with the above-mentioned automated coating device, is efficient, accurate and reliable, and is suitable for mass production of low-resistance thick film resistors. The method ensures the uniformity of the coating and the stability of the resistance value through multi-step control, and the specific steps are as follows: S1: Select a conductive slurry suitable for low resistance and perform stirring and filtering.

[0060] In the coating process, it is very important to choose the right conductive paste. The paste of low-resistance thick film resistors usually contains conductive materials (such as silver, platinum or tungsten, etc.) and organic solvents. To ensure the stability of the paste and a good coating effect, first stir it thoroughly according to the formula to ensure the uniformity of the paste. Then, use a high-efficiency filter to filter the paste to remove impurities, large particles or other uneven substances that may exist in it, to ensure the purity of the paste and avoid defects in the coating process or affect the resistor performance.

[0061] S2: The substrate is placed and clamped, and sprayed layer by layer.

[0062] The treated substrate is placed on the working plate 8 and the drive motor is started for precise positioning. The sliding mechanism 6 will clamp the substrate to ensure that it remains stable and does not move during the entire coating process. According to the coating requirements, the slurry is evenly sprayed on the surface of the substrate by linear or spiral spraying, covering it layer by layer. The thickness of each layer is usually controlled between 10-25 microns. After spraying, it is dried for a short time by infrared lamp to remove the solvent and solidify each layer of coating to ensure the adhesion and uniformity of the next layer of coating. Through the repeated process of multi-layer spraying and drying, the required resistance value and coating thickness are gradually achieved.

[0063] S3: Low temperature drying.

[0064] After coating, the substrate needs to be dried at low temperature to remove the solvent and volatiles in the slurry. Usually, the drying temperature is set between 100-150°C and the drying time is 10-30 minutes. The specific time is adjusted according to the thickness of each layer of slurry and the volatility characteristics of the slurry. This process helps to accelerate the volatilization of the solvent, prevent the resistance performance from being affected by excessive solvent residue, and ensure the adhesion of the coating.

[0065] S4: sintering treatment.

[0066] The dried substrate will be sent to the sintering furnace for sintering. The sintering process can completely remove the organic matter in the coating, make the conductive material tightly combined, and improve the stability of the resistor. According to the different characteristics of the slurry used, set an appropriate sintering curve, generally using a heating rate of 1-5°C / min, and gradually heat to between 600-900°C. Keep at this temperature for 10-30 minutes to ensure that the coating is completely sintered. Then, slowly cool to room temperature, control the cooling rate, and avoid thermal stress caused by excessive temperature difference, which will cause cracks or fall off.

[0067] S5: Resistance test and fine-tuning.

[0068] After sintering, the resistance value is tested using a high-precision bridge or multimeter. Based on the deviation between the measured resistance value and the design target, if the resistance value does not meet the expectations, the coating is fine-tuned using laser trimming technology to ensure that the resistance value precisely meets the requirements. During this process, it is also necessary to check whether the coating is uniform and whether there are defects such as bubbles, cracks or particle accumulation. Only when the coating is perfect and the resistance value meets the standard can the product pass the test and enter the next production stage.

[0069] Through this series of rigorous coating, drying, sintering and fine-tuning steps, this method can ensure the high quality and consistency of low-resistance thick film resistors, which are suitable for applications with high requirements for accuracy and stability in industrial production.

[0070] During the working process of the present invention, a series of precisely designed components are used to ensure the stability and precise positioning of the substrate during the coating process. First, the substrate is placed on the working plate 8, which provides a stable support platform for the substrate to ensure that the substrate will not be displaced during the coating process. Subsequently, the drive motor is started, and the rotating disk 41 is driven to rotate through the transmission device, driving the substrate to rotate evenly. This rotational motion provides the necessary power support for the subsequent coating steps, making the coating process more uniform and efficient.

[0071] During this process, the control slide bar 66 engaged in the control slide groove 42 is subjected to the force of the driving motor, and then contracts. The contraction of the control slide bar 66 causes the slider 61 to slide along a predetermined path in the fixed track 52. Through the precise movement of the control slide bar 66, the position of the substrate can be fine-tuned, thereby ensuring the precise positioning and stable movement of the substrate. The cooperation between the limit block 524 and the limit groove 62 further enhances the stability of the movement of the slider 61, prevents the slider 61 from excessive displacement or loss of control, and ensures the high precision of the entire coating process.

[0072] To further ensure the stable fixation of the substrate, the fixing block 64 clamps the substrate inward from the four corners of the substrate to firmly fix it on the working plate 8. By evenly clamping the four corners, the fixing block 64 can provide sufficient pressure to ensure that the substrate will not tilt or shift during the coating process, ensuring the uniformity of each layer of coating and the integrity of the pattern. This innovative design effectively improves the stability and accuracy of the coating process, providing a strong guarantee for the production of low-resistance thick film resistors.

[0073] Various modifications to the present disclosure will be apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but should be given the widest scope consistent with the principles and novel features disclosed herein. Although one or more exemplary embodiments of the present disclosure have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as defined in the appended claims.

Claims

1. An automatic coating device for low resistance thick film resistors, characterized in that: It comprises a bracket (11), a base (2), a coating head (3), a rotating assembly (4), a fixing mechanism (5), a sliding mechanism (6), a starting motor (7) and a working plate (8); The bracket (11) is mounted on the ground, the base (2) is mounted on the bracket (11), the coating head (3) is mounted inside the base (2), the rotating assembly (4) is mounted on the base (2), the fixing mechanism (5) is mounted on the rotating assembly (4), the sliding mechanism (6) is mounted inside the fixing mechanism (5), the starting motor (7) is mounted below the rotating assembly (4), and the working plate (8) is mounted on the fixing mechanism (5); the starting motor (7) drives the rotating assembly (4) to rotate, so that the control slide rod (66) moves under the drive of the control slide groove (42), driving the slider (61) to contract inward or expand outward in the fixed track (52).

2. The automatic coating device for low-resistance thick film resistor according to claim 1, characterized in that: The rotating assembly (4) comprises a rotating disk (41), a control slide groove (42) and a rolling groove (43); The rotating disk (41) is mounted on the base (2), the control slide groove (42) is provided on the rotating disk (41), and the rolling groove (43) is provided on the inner side surface of the control slide groove (42).

3. The automatic coating device for low-resistance thick film resistor according to claim 2, characterized in that: The control slide groove (42) is configured to be in an arc shape, the rolling groove (43) is located on the central axis of the inner side surface of the control slide groove (42), and the rolling groove (43) is configured to be in a semicircular shape.

4. The automatic coating device for low-resistance thick film resistor according to claim 1, characterized in that: The fixing mechanism (5) comprises a fixing plate (51) and a fixing rail (52); The fixed disk (51) is mounted on the base (2), and the fixed rails (52) are mounted in an annular array on the side of the fixed ring.

5. The automatic coating device for low-resistance thick film resistor according to claim 4, characterized in that: The fixed track (52) comprises an upper notch (521), a lower notch (522), a translation slot (523) and a limit block (524); The upper notch (521) is formed on the upper side of the fixed track (52), the lower notch (522) is formed on the lower side of the fixed track (52), the translation slot (523) is formed on the side of the lower notch (522), and the limit block (524) is mounted on the side of the interior of the fixed block (64).

6. The automatic coating device for low-resistance thick film resistor according to claim 5, characterized in that: The translation groove (523) is configured in a semicircular shape, and the limiting block (524) is configured in a trapezoidal shape.

7. The automatic coating device for low-resistance thick film resistor according to claim 1, characterized in that: The sliding mechanism (6) comprises a sliding block (61) and a limiting groove (62); The sliding block (61) is installed inside the fixing mechanism (5), and the limiting grooves (62) are provided on both sides of the sliding block (61).

8. The automatic coating device for low-resistance thick film resistor according to claim 7, characterized in that: The sliding mechanism (6) further comprises a connecting block (63), a fixing block (64) and a placement groove (65); The connecting block (63) is mounted on the upper side of the sliding block (61), and the fixing block (64) is mounted on the upper side of the connecting block (63). The fixing block (64) is arranged in a triangular shape, and the placement groove (65) is provided in the middle of the fixing block (64).

9. The automatic coating device for low-resistance thick film resistor according to claim 8, characterized in that: The sliding mechanism (6) further comprises a control sliding rod (66), a rolling ball (67), a translation ring (68) and a protection block (69); The control slide bar (66) is mounted below the slider (61), the rolling ball (67) is mounted on the surface of the control slide bar (66), the translation ring (68) is mounted above the rolling ball, and the protection block (69) is mounted below the control slide bar (66).

10. A coating method for a low-resistance thick film resistor, the method being used in conjunction with an automated coating device for a low-resistance thick film resistor as claimed in any one of claims 1 to 9; characterized in that: The steps of the method are as follows: S1: Select a conductive paste suitable for low resistance, stir it according to the formula of the conductive paste, and remove impurities or large particles in the paste by filtering; S2: placing the substrate on the working plate (8), starting the driving motor, and clamping the substrate with the sliding mechanism (6), and using a linear or spiral spraying method to cover the substrate layer by layer until it reaches 10-25 microns. After each layer is sprayed, it is dried for a short time with an infrared lamp before spraying the next layer; S3: Dry the coated substrate at low temperature (100-150°C) to remove the solvent and volatiles in the slurry. The drying time is set to 10-30 minutes, which is adjusted according to the slurry thickness. S4: Place the dried substrate into a sintering furnace, set the sintering curve according to the characteristics of the slurry, increase the temperature at a rate of 1-5°C / min, keep it at 600-900°C for 10-30 minutes, and cool it to room temperature at a controlled rate to avoid cracks caused by thermal stress; S5: Use a high-precision bridge or multimeter to test the resistance value. If the resistance value deviates from the design target, it can be fine-tuned by laser trimming. Check whether the coating is uniform and there are no bubbles, cracks or particle accumulation.

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