Cosmetic mask based on multi-layer circuit board and COB packaging and packaging manufacturing method thereof

Abstract

The application discloses a beauty mask based on a multilayer circuit board and COB packaging and a packaging manufacturing method thereof, and relates to the technical field of beauty instruments. The beauty mask directly integrates light-emitting LEDs on a multilayer circuit board, and combines a layered structure design of a top signal trace layer, a grounding layer, a power supply layer and an isolation layer, so that the overall electrical performance stability is effectively improved while the structure is lightened and thinned. Through the continuous copper coating of the grounding layer, the uniform wiring of the power supply layer and the interlayer via hole conduction, the power supply path is more balanced, the voltage drop difference between different light-emitting LEDs is reduced, the consistency of light emission in each region is improved, and electromagnetic interference is reduced. In combination with the COB packaging mode, the light-emitting LEDs can be arranged at high density without independent packaging, the overall thickness is reduced, the number of light sources per unit area is increased, and the beauty mask can form more uniform and continuous light coverage during the working process.

Description

Technical Field

[0001] This invention relates to the field of beauty instrument technology, and in particular to a beauty mask based on multilayer circuit board and COB packaging and its packaging manufacturing method. Background Technology

[0002] Existing beauty masks mostly employ traditional stacked light board structures or discrete component layouts. Their overall structure typically consists of a single-layer or simple double-layer circuit board combined with a shell. To ensure structural strength and electrical connection reliability, additional support components and encapsulation thickness are often required, resulting in a relatively thick and heavy product with poor wearing comfort. Prolonged use can easily cause pressure and negatively impact the user experience. Furthermore, existing solutions often use a distributed arrangement of light-emitting units, with large spacing between LEDs or light beads, resulting in low light density per unit area. This makes it difficult to achieve uniform coverage of the facial skin, easily leading to insufficient or uneven illumination in certain areas, thus affecting the stability and consistency of the beauty effect. Moreover, limitations in existing circuit board design, especially unreasonable power and grounding wiring layouts, and significant differences in power supply paths, cause inconsistent voltage drops in light-emitting units at different locations. This results in uneven brightness and light attenuation in some areas, affecting the overall performance. Furthermore, most existing beauty masks employ a unified overall control strategy, lacking the ability to precisely manage different facial areas. They cannot provide differentiated irradiation for various skin problems such as acne, sebum secretion, pigmentation, or collagen loss, easily leading to over-illumination in some areas and under-illumination in others. This not only reduces the targeted nature of the treatment but may also impose potential burdens on the skin. Patent application CN114028728A, filed on November 20, 2021, discloses an LED light therapy mask. While it diffuses LED light through a light diffusion layer to illuminate the face and controls the luminous power of the LED point light sources based on the mask's duration and designated light therapy areas to improve treatment or cosmetic effects, the improvement focuses primarily on the timing of mask application and light therapy, and power control, without optimizing the internal circuit board structure of the beauty mask. Moreover, the LED point light sources in this solution are still discretely arranged, making it difficult to improve light source density, packaging reliability, and light emission consistency. Therefore, how to improve the light source density and illumination uniformity, optimize power supply stability, and achieve fine-grained zone control while ensuring a lightweight and thin structure has become a pressing technical problem to be solved in this field. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a beauty mask based on multilayer circuit boards and COB packaging and a packaging manufacturing method thereof, in order to solve the problems of the beauty mask being relatively thick and heavy and having uneven lighting in the prior art.

[0004] In a first aspect, embodiments of the present invention provide a beauty mask based on a multilayer circuit board and COB packaging, characterized in that it includes an outer cover layer, an inner cover layer, and a multilayer circuit board disposed between the outer cover layer and the inner cover layer, wherein the inner cover layer is located on the side of the multilayer circuit board closer to human skin and is used to form a light-emitting layer facing human skin; the outer cover layer is located on the side of the multilayer circuit board away from human skin; and the outer cover layer is used to form structural support for the multilayer circuit board. The multilayer circuit board includes a top-level signal trace layer, a ground layer, a power layer, and an isolation layer arranged sequentially from the side closest to the inner cover layer to the side closest to the outer cover layer; The top signal trace layer is provided with a plurality of light-emitting LEDs encapsulated by COB adhesive. The plurality of light-emitting LEDs are arranged facing the inner cover layer so that the light emitted by the light-emitting LEDs is emitted through the inner cover layer and onto human skin; the top signal trace layer is used to realize the signal transmission of the light-emitting LEDs; The grounding layer is located on the side of the top signal trace layer away from the inner cover layer, and forms a grounding trace corresponding to the light-emitting LED; The power layer is located on the side of the ground layer away from the top signal trace layer, and forms a positive trace corresponding to the light-emitting LED; The isolation layer is located on the side of the power layer opposite to the ground layer, and no traces are provided on the isolation layer.

[0005] Preferably, the ground layer and the power layer of the multilayer circuit board are respectively connected to the top signal trace layer through vias; and the ground layer adopts a continuous copper-clad structure, the power layer adopts a uniform wiring structure, and the isolation layer has no traces, so as to make the power supply current of each LED tend to be uniform and reduce electromagnetic interference.

[0006] Preferably, each of the light-emitting LEDs is provided with a corresponding built-in control chip, wherein the data signal pins of each built-in control chip are connected in series, and the control signal pins are connected to the main controller.

[0007] Preferably, the beauty mask is divided into several light-emitting areas, including a first area and a second area covering the cheeks, a third area covering the area around the mouth, a fourth area covering the forehead, and a fifth area covering the area around the eyes and the sides of the nose.

[0008] Preferably, the light-emitting LED includes LED chips capable of emitting light in different wavelength ranges. The different wavelength ranges include at least one or more of the following: a first wavelength range of 400-430nm, a second wavelength range of 560-610nm, a third wavelength range of 610-680nm, and a fourth wavelength range of 800-1100nm. The LED chips in each of the light-emitting regions are capable of outputting light in one or more of the first, second, third, and fourth wavelength ranges.

[0009] Preferably, the main controller is configured to selectively control the output of corresponding wavelength light in the corresponding luminescent area according to the skin problems corresponding to different luminescent areas, and limit the output of light within the first wavelength range in non-target luminescent areas, so as to reduce the excessive irradiation of blue-violet light in non-target areas of the human face.

[0010] Preferably, the main controller is configured to determine the corresponding care function according to different skin problems and control the LED chips in each light-emitting area to selectively output light of different wavelengths. When used for acne treatment or oil control care, light within the first wavelength range is output at least; when used for whitening care, light within the second wavelength range and the third wavelength range is output at least; when used for collagen-promoting care, light within the third wavelength range and the fourth wavelength range is output at least.

[0011] Preferably, the main controller is configured to determine corresponding care functions according to different skin problems and control the LED chips in each light-emitting area to emit light according to a preset combination and ratio of wavelengths, wherein: for acne treatment, the LED chips are controlled to output a combination of light from a first wavelength range and a fourth wavelength range, and the output ratio of the corresponding wavelengths is 1:1; for oil control treatment, the LED chips are controlled to output light from a first wavelength range, and the output power of the light from the first wavelength range does not exceed a preset power threshold; for whitening treatment, the LED chips are controlled to output a combination of light from a second wavelength range, a third wavelength range, and a fourth wavelength range, and the output ratio of the corresponding wavelengths is 1:1:1 or the output ratio of the second wavelength range is increased; for collagen-promoting treatment, the LED chips are controlled to output a combination of light from a third wavelength range and a fourth wavelength range, and the output ratio of the corresponding wavelengths is 1:1.

[0012] In a second aspect, embodiments of the present invention provide a method for packaging and manufacturing a beauty mask, applicable to the beauty mask described in any one of the first aspects, the method comprising: A circuit board substrate is obtained, and a top-layer signal trace layer, a ground layer, a power layer, and an isolation layer are formed based on the circuit board substrate to construct a multilayer circuit board; wherein, Signal traces for light-emitting LEDs are formed on the top-level signal trace layer; A ground trace corresponding to the light-emitting LED is formed on the ground layer, and the ground layer is connected to the top signal trace layer through vias; A positive electrode trace corresponding to the light-emitting LED is formed on the power layer, and the power layer is connected to the top signal trace layer through vias; A plurality of light-emitting LEDs are disposed on the top signal trace layer and arranged facing the inner cover layer. COB dispensing encapsulation is performed on multiple of the aforementioned light-emitting LEDs; A multilayer circuit board with COB dispensing encapsulation is placed between an outer cover layer and an inner cover layer. The top signal trace layer is located on the side closer to the inner cover layer, and the isolation layer is located on the side closer to the outer cover layer. The inner cover layer is located on the side of the multilayer circuit board closer to the human skin and forms a light-emitting layer facing the human skin. The outer cover layer is located on the side of the multilayer circuit board away from the human skin and forms structural support for the multilayer circuit board, thereby obtaining a beauty mask.

[0013] Preferably, before performing COB dispensing encapsulation on the plurality of light-emitting LEDs, the method further includes: The multilayer circuit board is divided into several light-emitting areas, and a corresponding built-in control chip is set in each light-emitting area; The data signal pins of each of the built-in control chips are connected in series, and the control signal pins of each of the built-in control chips are connected to the main controller.

[0014] In summary, the beneficial effects of the present invention are as follows: The beauty mask based on a multilayer circuit board and COB packaging provided in this invention integrates light-emitting LEDs directly onto the multilayer circuit board. Combined with a layered structure design including a top-level signal routing layer, ground layer, power layer, and isolation layer, this design achieves a thinner and lighter structure while effectively improving overall electrical performance stability. The multilayer circuit board employs a flexible structure that conforms to the curved surface of the human face, bringing each light-emitting area closer to the skin surface, thereby reducing light gaps and improving light energy utilization efficiency. Through continuous copper plating on the ground layer, uniform wiring on the power layer, and vias between layers, the power supply path is more balanced, reducing voltage drop differences between different light-emitting LEDs, thus improving the consistency of light emission in each area and reducing electromagnetic interference. Combined with COB packaging, the light-emitting LEDs can be arranged in a high-density configuration without separate packaging, reducing the overall thickness and increasing the number of light sources per unit area, enabling the mask to achieve a more uniform and continuous light coverage effect during operation.

[0015] Furthermore, at the control level, by dividing the mask into multiple light-emitting areas and enabling each area to output multiple wavelengths, and by controlling the combination of wavelengths and selection of areas based on skin problems, different facial areas can receive targeted light therapy solutions. Simultaneously, by preset wavelength combinations and ratios for different care modes, switching between multiple phototherapy functions can be achieved without complex dimming, maintaining stable operation even under limited heat dissipation conditions. Overall, this invention achieves synergistic effects in structural design, power supply balance, spectral control, and zoned treatment, not only improving the uniformity of light illumination and the care effect of the beauty mask, but also ensuring wearing comfort and device reliability. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, and these are all within the protection scope of the present invention.

[0017] Figure 1 This is a schematic diagram of the beauty mask provided in an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the layered structure of the beauty mask according to an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the top-level signal routing layer in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the grounding layer according to an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the power supply layer according to an embodiment of the present invention.

[0022] Figure 6 This is a schematic flowchart of the packaging manufacturing method according to an embodiment of the present invention. Detailed Implementation

[0023] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the invention.

[0024] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0025] Example 1 Please see Figure 1 and Figure 2 This invention provides a beauty mask based on a multilayer circuit board and COB packaging, comprising: an outer cover layer, an inner cover layer, and a multilayer circuit board disposed between the outer cover layer and the inner cover layer. The inner cover layer is located on the side of the multilayer circuit board closer to human skin and is used to form a light-emitting layer facing the human skin. The outer cover layer is located on the side of the multilayer circuit board away from human skin. The outer cover layer is used to provide structural support for the multilayer circuit board. The multilayer circuit board includes a top-level signal trace layer, a ground layer, a power layer, and an isolation layer arranged sequentially from the side closest to the inner cover layer to the side closest to the outer cover layer; The top signal trace layer is provided with a plurality of light-emitting LEDs encapsulated by COB adhesive. The plurality of light-emitting LEDs are arranged facing the inner cover layer so that the light emitted by the light-emitting LEDs is emitted through the inner cover layer and onto human skin; the top signal trace layer is used to realize the signal transmission of the light-emitting LEDs; The grounding layer is located on the side of the top signal trace layer away from the inner cover layer, and forms a grounding trace corresponding to the light-emitting LED; The power layer is located on the side of the ground layer away from the top signal trace layer, and forms a positive trace corresponding to the light-emitting LED; The isolation layer is located on the side of the power layer opposite to the ground layer, and no traces are provided on the isolation layer.

[0026] Specifically, the beauty mask provided in this embodiment adopts a layered structure design. Its core lies in the arrangement of multiple circuit boards and COB-packaged light-emitting units to achieve a thinner structure, improved electrical stability, and optimized light uniformity. For example... Figure 1 This is a schematic diagram of one side of the inner layer of a beauty mask, as shown below. Figure 2The diagram shows the layered structure of a beauty mask. Figure 2 As shown, the outer and inner covers are located on opposite sides of the multilayer circuit board. The outer cover, located away from the skin, primarily provides support and protection, offering overall structural strength and resisting external impacts. The inner cover, located closer to the skin, serves as the light output interface. Its material typically possesses a certain degree of light transmittance and flexibility, allowing the light generated by the LEDs to be evenly transmitted and conform to the facial contours, thus forming a stable and comfortable light-emitting layer. In this structure, the multilayer circuit board is positioned between the outer and inner covers, serving both as an electrical connection and a carrier for the light-emitting units. It is a key component for achieving synergistic optimization of electrical and optical performance. The multilayer circuit board is flexible, capable of bending and conforming to the curvature of the human face, allowing the light-emitting units to be spatially closer to the skin surface, reducing local gaps, thereby improving the uniformity of light coverage and enhancing wearing comfort.

[0027] From a hierarchical perspective, a multilayer circuit board, from the side closest to the inner cover to the side closest to the outer cover, includes, in sequence, a top-level signal trace layer, a ground layer, a power layer, and an isolation layer, such as... Figure 3-5 The diagrams show the top signal trace layer, ground layer, and power layer. The top signal trace layer faces the light emission direction directly and houses multiple LEDs, which are directly integrated onto the circuit board surface using COB (Chip-on-Board) encapsulation. This method eliminates the need for traditional discrete LED packaging, achieving a high-density LED arrangement. This not only effectively reduces the overall thickness but also significantly increases the number of light sources per unit area, allowing for more uniform and continuous illumination of the skin during operation. Simultaneously, the LEDs are positioned towards the inner cover layer, ensuring the light is emitted vertically or nearly vertically, diffused by the inner cover layer, and then applied to the skin, thus reducing lateral loss and improving light utilization efficiency. The top signal trace layer also handles signal transmission between the LEDs and the built-in integrated circuits. Through proper signal trace routing, control signals are stably transmitted to the corresponding driver units of each LED.

[0028] A ground plane is placed below the top signal trace layer to form a complete ground loop. By forming ground traces corresponding to the LEDs on this layer, the negative terminals of each LED can be reliably grounded. Furthermore, the ground plane typically uses a large copper area and is electrically connected to the top signal trace layer via vias, thus forming a low-impedance grounding path, which helps reduce noise interference and improve overall electrical stability. A power plane is placed below the ground plane to provide positive power. By forming positive traces corresponding to the LEDs on this layer and connecting it to the top signal trace layer via vias, power can be evenly distributed to each LED. Uniform routing design on the power plane effectively shortens the power path differences between different LEDs, making the current distribution more consistent, thereby reducing voltage drop differences and avoiding inconsistent brightness caused by uneven voltage, thus improving overall luminous efficacy consistency.

[0029] An isolation layer is placed below the power layer. This isolation layer has no wiring and its main function is to provide electromagnetic isolation between the upper power layer and other structures below, reducing interlayer coupling interference. By setting this isolation layer, interference propagation caused by high-frequency signals or current changes can be effectively suppressed, improving the overall anti-interference capability and operational stability of the system. In summary, through the high-density COB light-emitting layout on the top layer, the layered power supply structure of the ground layer and power layer, and the interference suppression effect of the isolation layer, stable power supply and uniform light emission are achieved in the slim and lightweight structure of the beauty mask.

[0030] In summary, this invention employs COB flip-chip packaging technology, directly encapsulating the light-emitting chip onto the circuit board, unlike the traditional structure that first encapsulates the chip into an independent finished LED bead and then mounts the finished LED bead onto the circuit board. By eliminating the need for the LED bead's own support frame, packaging shell, and the height space occupied by secondary mounting, the overall thickness of the light-emitting module is reduced, facilitating a thinner and lighter structure. With flip-chip packaging, individual chips can be arranged more densely on the circuit board. Compared to the traditional method of mounting finished LED beads, more light-emitting chips can be arranged within the same area, increasing the number of light-emitting points and making their distribution more uniform. Multiple light-emitting points can complete light mixing and brightness transition within a shorter distance, thereby reducing graininess, dark areas, and bright spots, allowing the effective light-emitting distance to be controlled within 15mm. Furthermore, the circuit board adopts a four-layer design, with multiple layers of circuitry for the power layer, ground layer, and signal control circuitry, making the power supply circuit more stable and the line impedance and voltage drop easier to control. Compared to single-layer or double-layer circuit boards, four-layer boards can improve problems such as uneven current distribution, voltage fluctuations, and localized heat generation, enabling each light-emitting chip to obtain a more stable driving voltage and driving current, thereby improving overall light emission stability and reducing inconsistent brightness, flickering, or abnormal localized light emission phenomena.

[0031] In one embodiment, each of the light-emitting chips is provided with a corresponding built-in control chip, wherein the data signal pins of each of the built-in control chips are connected in series, and the control signal pins are connected to the main controller.

[0032] Specifically, each LED has an independent built-in control chip in a mini1618 package for individual driving control of each LED. The data signal pins of these built-in control chips are cascaded, meaning the data output of one chip is connected to the data input of the next, forming a continuous data transmission link. This allows the control data output from the main controller to be transmitted sequentially to the corresponding built-in control chip for each LED. Simultaneously, the control signal pins of each built-in control chip are connected to the same main controller. This cascaded connection reduces the number of data lines required between the main controller and the built-in control chips, simplifies the wiring structure, and reduces circuit complexity, facilitating the integration and thinner design of multilayer flexible circuit boards.

[0033] In one embodiment, the beauty mask is divided into several luminous areas. Using a data cascading transmission mechanism, different driving data can be assigned to different luminous areas, creating differences in brightness, luminous timing, or operating mode among the areas. This allows for precise illumination control of different facial regions. Furthermore, this structure reduces the risk of signal interference caused by long-distance parallel wiring, improves signal transmission stability and system reliability, and enables the beauty mask to achieve regional control while maintaining driving accuracy and electrical performance. Different IDs can be assigned to different luminous areas, and the main controller can achieve regional control by recognizing these IDs.

[0034] In one embodiment, the light-emitting areas include a first area and a second area covering the cheeks, a third area covering the area around the mouth, a fourth area covering the forehead, and a fifth area covering the area around the eyes and the sides of the nose. In this embodiment, the light-emitting areas of the beauty mask are functionally divided according to the structural characteristics of the human face and the different light requirements of different parts of the face. The first and second areas correspond to the left and right cheeks, respectively, and are used to cover larger areas of the face. These areas typically require relatively uniform and moderately intense light to promote overall skin improvement. The third area is located around the mouth, mainly corresponding to the nasolabial folds and perioral skin. This area has sensitive skin with significant texture variations, and independent control allows for relatively gentle or targeted light adjustment. The fourth area covers the forehead, which is relatively flat and has a relatively uniform skin thickness, suitable for stable and continuous light output to enhance the overall phototherapy effect. The fifth area covers the area around the eyes and the sides of the nose. This area has a complex structure and high skin sensitivity; separate division allows for low-intensity or pulsed light control to avoid discomfort and improve safety. By setting up the above-mentioned zones, each luminous area can be driven and controlled differently according to the physiological characteristics of its corresponding facial location, thereby achieving a more refined and personalized beauty care effect while ensuring the overall uniformity of illumination.

[0035] In one embodiment, the light-emitting LED includes LED chips capable of emitting light in different wavelength ranges. These different wavelength ranges include at least one or more of a first wavelength range of 400-430nm, a second wavelength range of 560-610nm, a third wavelength range of 610-660nm, and a fourth wavelength range of 800-1100nm. Each LED chip in the light-emitting region is capable of outputting light in one or more of the first, second, third, and fourth wavelength ranges. Specifically, the light-emitting LED is composed of LED chips capable of emitting multiple wavelengths of light. Different wavelengths correspond to different skin care needs. The first wavelength range of 400-430nm mainly corresponds to short-wave blue light, used to improve the skin surface microenvironment; the second wavelength range of 560-610nm corresponds to the yellow or green light range, helping to improve skin tone evenness; the third wavelength range of 610-660nm corresponds to the red light range, which can act on deeper skin tissue to promote activity regulation; and the fourth wavelength range of 800-1100nm corresponds to near-infrared light, used to achieve deeper penetration and repair. Each luminescent area is equipped with an LED chip capable of emitting at least one or more of the aforementioned wavelengths of light. By configuring multiple wavelength light sources within the same area or achieving multi-wavelength emission through the same chip, different facial areas can output corresponding combinations of spectra according to a preset control strategy during operation, thereby achieving regional, multi-wavelength illumination. Combined with the independent control capabilities of the built-in control chip, the output ratio and working sequence of each wavelength of light can be flexibly adjusted for different skin conditions. This allows the beauty mask to not only cover various care scenarios but also improve light energy utilization efficiency and overall care effect while ensuring uniform illumination.

[0036] In one embodiment, the main controller is configured to selectively control the output of corresponding wavelengths of light from different luminescent areas based on the skin problems associated with those areas, and to limit the output of light within a first wavelength range from non-target luminescent areas, thereby reducing excessive irradiation of blue-violet light on non-target areas of the human face. Specifically, a correspondence between luminescent areas and facial skin problems can be pre-established. For example, short-wavelength blue light can be used for areas prone to oiliness or acne, while red, yellow, or near-infrared light is prioritized for areas requiring repair or brightening. During actual operation, the main controller selectively controls the built-in control chip of each luminescent area according to a preset strategy or a user-selected mode, ensuring that the target luminescent area outputs wavelengths of light matching its corresponding skin problem. Simultaneously, for luminescent areas not selected as target areas, the main controller constrains their output spectrum, particularly limiting the output of light within the first wavelength range, thereby preventing the diffusion of blue-violet light into non-target areas. This differentiated control approach can, on the one hand, enhance the effectiveness of targeted care, allowing different areas to receive more suitable light types; on the other hand, it can reduce the exposure of high-energy short-wave light to unwanted areas, reduce stimulation to sensitive areas, improve overall safety and comfort, and simultaneously balance energy utilization efficiency and phototherapy precision.

[0037] In one embodiment, the main controller is configured to determine corresponding care functions based on different skin problems and control the LED chips in each luminescent area to selectively output light of different wavelengths. Specifically, for acne treatment or oil control, light within the first wavelength range is output; for whitening treatment, light within the second to third wavelength range is output; and for collagen-promoting treatment, light within the third to fourth wavelength range is output. In this embodiment, the main controller can pre-store the correspondence between skin problems and care functions, and generate driving control strategies for different areas based on the facial position characteristics corresponding to each luminescent area. For example, when a user selects an acne treatment or oil control mode, the main controller prioritizes driving and configuring the LED chips in the target luminescent area to output light within the first wavelength range. By limiting the participation of other wavelengths or reducing their proportion, the area is made into an irradiation environment dominated by short-wavelength light. When switching to a whitening mode, the main controller controls the LED chips in each luminescent area to output light within the second and third wavelength ranges as needed. By adjusting the duty cycle or output sequence of different wavelengths, the two wavelengths can be superimposed or alternately applied to the skin, thereby achieving more balanced spectral coverage. In a collagen-promoting mode, the controller controls the relevant luminescent areas to output light within the third and fourth wavelength ranges. By increasing the continuous output time or enhancing the output intensity of these wavelengths, the light energy can more effectively act on the deep structures of the skin. For example, for areas with acne or oily skin, the corresponding luminescent area is preferentially controlled to output blue-violet light with a center wavelength of approximately 415nm to target problem areas on the skin surface; for whitening care, the luminescent area is controlled to output a combination of light at approximately 590nm and 630nm to improve uneven skin tone through the synergistic effect of multiple wavelengths; for care scenarios that promote collagen production, the luminescent area is controlled to output 630nm light and combined with one of the near-infrared wavelengths of 850nm, 940nm, or 1060nm to form a combined light to enhance the effect on deeper skin tissues.

[0038] Furthermore, the main controller can refine the output strategy under the same care mode based on the spatial location of different light-emitting areas. For example, it can use a continuous and stable output mode for the cheek area, while using an intermittent or low duty cycle output mode for the eye area or nose area to reduce discomfort in sensitive areas. Simultaneously, by finely adjusting the on / off sequence, drive current, and output cycle of the LED chips in each light-emitting area, multi-band light zonal control can be achieved, allowing different areas to exhibit differentiated spectral distributions within the same time period. This multi-region, multi-band control mechanism based on skin problems not only improves the adaptability of beauty masks in different care scenarios but also enhances targeted effects while ensuring overall light uniformity, and balances energy utilization efficiency and safety.

[0039] In one embodiment, the main controller is configured to determine corresponding care functions based on different skin problems and control the LED chips in each light-emitting area to emit light according to a preset combination and ratio of wavelengths. Specifically: for acne treatment, the LED chips are controlled to output a combination of light from a first wavelength range and a fourth wavelength range, with the output ratio of the corresponding wavelengths being 1:1; for oil control, the LED chips are controlled to output light from a first wavelength range, with the output power of the light from the first wavelength range not exceeding a preset power threshold; for whitening, the LED chips are controlled to output a combination of light from a second, third, and fourth wavelength range, with the output ratio of the corresponding wavelengths being 1:1:1 or increasing the output ratio of the second wavelength range; for collagen-promoting care, the LED chips are controlled to output a combination of light from a third and fourth wavelength range, with the output ratio of the corresponding wavelengths being 1:1.

[0040] Specifically, the main controller can pre-store the correspondence between different skin problems, care functions, and wavelength combinations. Upon receiving a user-selected care mode, area care command, or preset program call signal, it sends control data to the built-in control chip corresponding to the LEDs in each luminous area. This controls the LED chips in each luminous area to emit light according to the set wavelength combinations and ratios. Specifically, when the main controller determines that acne treatment is needed, it outputs a corresponding drive command to the target luminous area, causing some LED chips in that area to emit light within a first wavelength range and others to emit light within a fourth wavelength range, maintaining a 1:1 output ratio between the two wavelengths. This setup allows the first wavelength range to target the problem areas on the skin's surface, while the fourth wavelength range enhances the effect on deeper tissues, creating a composite light effect within the same area and improving the targeted and comprehensive nature of the acne treatment. For the oil-control mode, the main controller controls the target luminescent area to primarily output light within the first wavelength range. By limiting the drive current, conduction time, or duty cycle, the output power of this wavelength band is kept below a preset power threshold. This achieves oil control while avoiding skin irritation caused by prolonged high-power exposure to short-wavelength light. This setting is particularly suitable for areas of the face that are both oily and sensitive. For the whitening mode, the main controller causes the LED chips in the relevant luminescent area to output a combination of light from the second, third, and fourth wavelength ranges. In the basic mode, these three wavelengths can be set in a 1:1:1 ratio to form a more balanced composite spectrum. When a whitening effect is desired, the output proportion of the second wavelength range can be appropriately increased, increasing its share in the overall spectrum and enhancing the treatment effect on uneven skin tone and dullness. For the collagen-promoting mode, the main controller primarily controls the LED chips to output a combination of light from the third and fourth wavelength ranges, maintaining a 1:1 ratio. This allows the two wavelengths to work synergistically on the deeper skin tissues, improving the sustained effect on these areas.For example, in acne treatment mode, the main controller drives the luminescent area to output a combination of light with center wavelengths of approximately 415nm and 940nm, and sets the output power ratio of the two to 1:1, so that the surface and deep layers work synergistically. In oil control mode, the luminescent area is controlled to output a single band of light at 415nm, while the blue light output power is limited to no more than 10W, so as to reduce skin irritation while achieving oil control. In whitening mode, the main controller drives the luminescent area to output a combination of light at 590nm, 630nm and 850nm. Under normal circumstances, the power ratio of each band is 1:1:1, and the output ratio of 590nm can be increased to 2:1:1 as needed to enhance the effect of the corresponding band. In skin awakening or collagen-promoting treatment mode, the luminescent area is controlled to output a combination of light at 630nm and 850nm, and the LED bead configuration ratio of the two is set to 1:1, so that the two bands form a stable output.

[0041] Furthermore, the main controller can precisely control the output timing, duration, and power distribution of each luminescent area based on its location on the face, skin condition, and treatment needs. For example, for areas with concentrated acne, the continuous output time of the combined light from the first and fourth wavelength ranges in acne treatment mode can be prioritized, while the participation of corresponding wavelengths can be reduced in non-target areas. For areas requiring overall brightening, such as the cheeks or forehead, a relatively balanced luminescence time of the three wavelengths can be maintained in whitening mode to ensure comprehensive color illumination effects over large areas of the face. For more sensitive areas such as around the eyes or nose, when performing collagen-boosting or whitening treatments, the output intensity per unit time can be appropriately reduced, the continuous conduction time shortened, or a time-sharing alternating luminescence method can be used to reduce local irritation. Through this multi-wavelength combination control mechanism based on treatment functions, differentiated illumination strategies can be formed for each luminescent area within the same work cycle, thereby improving the adaptability of various treatment functions such as acne treatment, oil control, whitening, and collagen-boosting, while ensuring overall facial illumination uniformity while also considering local targeting, safety, and energy utilization efficiency.

[0042] In summary, the beauty mask based on a multilayer circuit board and COB packaging provided by this invention integrates the light-emitting LEDs directly onto the multilayer circuit board. Combined with a layered structure design including a top-level signal routing layer, ground layer, power layer, and isolation layer, this achieves a thinner and lighter structure while effectively improving overall electrical performance stability. The multilayer circuit board employs a flexible structure that conforms to the curved surface of the human face, bringing each light-emitting area closer to the skin surface, thereby reducing light gaps and improving light energy utilization efficiency. Through continuous copper plating on the ground layer, uniform wiring on the power layer, and vias between layers, the power supply path is more balanced, reducing voltage drop differences between different light-emitting LEDs, thus improving the consistency of light emission in each area and reducing electromagnetic interference. Combined with COB packaging, the light-emitting LEDs can be arranged in a high-density configuration without separate packaging, reducing the overall thickness and increasing the number of light sources per unit area, enabling the mask to achieve a more uniform and continuous light coverage effect during operation.

[0043] At the control level, by dividing the mask into multiple light-emitting zones and enabling each zone to output multiple wavelengths, and coordinating with the main controller to combine wavelengths and select zones based on skin problems, different facial areas can receive targeted light therapy. This allows for focused treatment of acne or inflamed areas while avoiding excessive exposure of non-target areas to blue-violet light, thus improving safety. Furthermore, by pre-setting wavelength combinations and ratios for different treatment modes, switching between multiple phototherapy functions can be achieved without complex dimming, maintaining system stability even under limited heat dissipation conditions. Overall, this invention achieves synergistic effects in structural design, power supply balance, spectral control, and zoned treatment, not only improving the uniformity of light exposure and treatment efficacy of the beauty mask but also considering wearing comfort, system reliability, and implementation cost, demonstrating significant application value.

[0044] Example 2 Based on the above embodiment one, this embodiment of the invention provides a packaging and manufacturing method for a beauty mask, which is applied to the beauty mask based on multilayer circuit board and COB packaging described in embodiment one.

[0045] Please see Figure 6 The packaging and manufacturing method of the beauty mask specifically includes the following steps: S1: Obtain a circuit board substrate, and form a top-layer signal trace layer, a ground layer, a power layer, and an isolation layer based on the circuit board substrate to construct a multilayer circuit board; wherein, S2: Signal traces for forming LEDs are formed on the top signal trace layer; S3: Form a ground trace corresponding to the light-emitting LED on the ground layer, and make the ground layer and the top signal trace layer connected through a via; S4: Form a positive electrode trace corresponding to the light-emitting LED on the power layer, and make the power layer and the top signal trace layer connected through a via; S5: A plurality of light-emitting LEDs are disposed on the top signal trace layer and the plurality of light-emitting LEDs are arranged facing the inner cover layer; S6: Perform COB dispensing encapsulation on the plurality of said light-emitting LEDs; S7: A multilayer circuit board with COB dispensing and encapsulation is placed between an outer cover layer and an inner cover layer, wherein the top signal trace layer is located on the side closer to the inner cover layer, and the isolation layer is located on the side closer to the outer cover layer. The inner cover layer is located on the side of the multilayer circuit board closer to the human skin and forms a light-emitting layer facing the human skin. The outer cover layer is located on the side of the multilayer circuit board away from the human skin and forms structural support for the multilayer circuit board, thereby obtaining a beauty mask.

[0046] Specifically, the multilayer circuit board substrate serves as the foundation for subsequent functional layers and light-emitting structures. A flexible substrate capable of bending with the curvature of the face is preferred, allowing the circuit board to better conform to the spatial contours of different areas such as the forehead, cheeks, and nose when combined with the outer and inner covers. On this substrate, a top-level signal routing layer, ground layer, power layer, and isolation layer are constructed sequentially from the side closest to the inner cover to the side furthest away. The top-level signal routing layer is first formed on the side closest to the inner cover because the LEDs ultimately emit light towards the skin; the chips are preferably placed directly on the routing layer closest to the inner cover to shorten the light-emitting path and reduce light blockage by intermediate structures. This top layer, in addition to supporting the LEDs themselves, also forms signal traces connected to the built-in control chip for transmitting control commands, enabling each chip to operate according to a preset mode. The signal routing here is not simply connecting the chips; it requires path planning based on the division of the light-emitting area, the location of the built-in control chip, and the contours of the face mask. This ensures that control signals stably reach their target locations while minimizing intersections with power supply paths to reduce the risk of subsequent electromagnetic coupling. Further, a ground layer and a power layer are formed. The ground layer is located below the top signal trace layer and is used to construct the grounding loop for the LEDs. The power layer is located below the ground layer and is used to form the positive power supply path. Both are connected to the top signal trace layer through vias. Vias are essentially conductive connection structures that penetrate the upper and lower layers. Their function is not simply to achieve interlayer conductivity, but rather to connect the top device mounting surface with the internal power supply network and ground network into a whole within the limited board thickness. This allows the LEDs to receive control signals from the top layer and obtain stable power supply and reliable return current through a shorter current path. The ground layer preferably adopts a continuous copper-clad form, which can form a large-area, low-impedance ground plane. This not only benefits the return current stability of each LED during operation but also helps absorb and disperse high-frequency interference. The power layer uses a uniform wiring method, focusing on minimizing the difference in power supply paths between different LED locations. This avoids problems such as excessive voltage difference, inconsistent brightness, or even localized overheating in certain areas due to excessively long traces or uneven power distribution. For example, the power layer adopts a serpentine reciprocating wiring structure. By arranging multiple parallel rows along a preset direction and connecting them at the ends, the power supply path is continuously distributed throughout the light-emitting area, thereby making the power supply path length of each LED more consistent and achieving balanced current distribution. In other embodiments, power supply lines can also be arranged in a symmetrical grid pattern around the power input point in the power layer, making the power supply path length from each LED to the power input point basically consistent, thereby achieving balanced current distribution. Alternatively, a ring power supply structure can be adopted, forming a closed power supply loop around the power layer, and supplying power to each LED from multiple points inward from this loop, allowing each LED to obtain power from different directions, thereby further reducing the difference in power supply paths and improving power supply consistency.

[0047] The lower isolation layer has no traces to weaken the coupling effect between the upper power supply layer, ground layer, and other structures, reduce interference propagation between different electrical functional layers within the multilayer board, and maintain higher stability of the entire light-emitting system during continuous operation. After completing each functional layer, multiple light-emitting LEDs are placed on the top signal trace layer. These LEDs are preferably bare LED chips, directly corresponding to the subsequent COB packaging process. The so-called arrangement facing the inner cover layer means that the light-emitting direction of the chip faces the direction of human skin. In this way, the emitted light can be directly directed to the face through the inner cover layer. The inner cover layer at this point not only provides isolation and protection for the skin but also forms the light-emitting interface, making the illumination softer and more suitable for actual use scenarios.

[0048] Subsequently, multiple LEDs are encapsulated using COB (Chip-on-Board) adhesive dispensing. COB essentially integrates the chip directly onto the board instead of fabricating individual LEDs and then mounting them. The adhesive dispensing process, after the chip is fixed and conductive, covers and protects it, creating an integrated light-emitting structure between the chip and the circuit board. This method reduces the height space occupied by traditional LED housings and additional encapsulation, contributing to a thinner overall mask. It also increases the chip density per unit area, resulting in a denser light distribution and improving dark areas and light spots during facial illumination. After COB encapsulation, the multi-layer circuit board is assembled between the outer and inner layers. The inner layer is located closer to the skin, forming the light-emitting layer facing the skin, while the outer layer is located away from the skin, providing mechanical support and protection for the multi-layer circuit board. The resulting beauty mask forms a sandwich-like structure: the outer layer provides support, the multi-layer circuit board provides power and light emission, and the inner layer emits light against the skin. This creates a highly integrated whole for the light-emitting unit, circuit structure, and wearing support. Through this entire implementation process, not only can we obtain beauty masks with lower thickness, higher light density, and better skin fit, but we can also significantly improve power supply uniformity and operational stability by leveraging the clear division of power, signal, and ground functions within the multilayer board.

[0049] In one embodiment, after forming a top signal trace layer, a ground layer, a power layer, and an isolation layer on a multilayer circuit board substrate, and before setting multiple light-emitting LEDs on the top signal trace layer, the method further includes: dividing the multilayer circuit board into several regions according to the facial contour corresponding to the beauty mask, and compensating for the positive electrode trace width, trace length, and / or via distribution in the power layer according to the path differences from the light-emitting LED positions in each region to the power input terminal, so as to reduce the voltage difference between different regions.

[0050] Specifically, the multilayer circuit board corresponds to different areas such as the forehead, cheeks, nose, and around the mouth. These areas differ in spatial location relative to the power input terminal. If a uniform wiring method is used directly, the power supply path length and equivalent impedance of the LEDs in different areas will vary significantly, resulting in inconsistent voltage drops during operation, leading to uneven brightness or localized overheating. Therefore, in this step, based on the actual structure of the beauty mask, the multilayer circuit board is first divided into several functional zones corresponding to the facial areas, and the power supply path distribution from the LEDs to the power input terminal in each zone is analyzed in the power layer. Based on this, the positive electrode traces in the power layer are adjusted accordingly. For example, for areas far from the power input terminal, the trace width can be appropriately increased or more vias can be added to reduce the path impedance, allowing current to be transmitted to that area more smoothly; while for areas closer, the trace length can be appropriately extended or the density of local vias can be reduced to avoid excessive current concentration. In addition, multi-point power supply or branch power supply structures can be introduced in different areas to allow power to enter each light-emitting area from multiple directions, thereby further reducing the differences in power supply paths. In this process, vias not only serve as interlayer conductors but also, by adjusting their number and distribution, alter the current path distribution, enabling more uniform power diffusion across the multilayer structure. Through the comprehensive compensation design of trace width, path length, and via distribution, the power supply conditions for LEDs in different areas are made more consistent. In actual operation, this effectively reduces the voltage difference between areas, improves overall light emission uniformity and system stability, and provides a more reliable electrical foundation for subsequent multi-band light output and zone control.

[0051] In one embodiment, forming a positive electrode trace corresponding to the light-emitting LED on the power layer and making the power layer and the top signal trace layer conductive through a via further includes: S41: Obtain the preset installation position of each LED on the top signal trace layer, and determine the light-emitting area to which each LED belongs; The preset installation positions of each LED on the top signal trace layer are obtained, and the light-emitting area of ​​each LED is determined. This is based on the pre-planned LED pad coordinates in the circuit board layout, mapping each LED to a specific illumination position on the beauty mask, such as the forehead area, cheek area, periorbital area, and chin area. Since beauty masks usually need to be arranged to fit the contours of the human face, the number of LEDs, their arrangement density, and illumination angles vary in different positions. Therefore, determining the installation positions and light-emitting areas first avoids ignoring the load differences in local areas by simply providing power to the entire circuit board.

[0052] S42: Calculate the maximum power supply load for each light-emitting area based on the number of LEDs, the band type, and the target driving current in each light-emitting area; Maximum power supply load refers to the maximum power demand that a certain light-emitting area may reach under a preset care mode. Its calculation is not simply based on the number of LEDs, but also considers the LED wavelength type and target drive current. In actual processing, LEDs can first be categorized according to the light-emitting area, for example, the forehead area, left cheek area, right cheek area, and perioral area can be treated as independent power supply statistics objects. Then, the number of LEDs in each area can be counted according to wavelength type, such as how many LEDs are in the first wavelength range, how many in the second wavelength range, and how many in the third wavelength range. Since the operating characteristics of LEDs in different wavelength ranges are different, their target drive current and forward voltage drop may be different. Therefore, it is necessary to multiply the number of LEDs in each wavelength range by the corresponding target drive current, and then sum them up according to whether each wavelength in the area can be lit simultaneously, thus obtaining the maximum power supply current requirement for that light-emitting area. When further evaluation of power consumption is needed, the maximum power supply can also be calculated by combining the operating voltage of each wavelength LED. For example, if the left cheek area has 6 red LEDs, 4 blue LEDs, and 4 near-infrared LEDs, with a target driving current of 20mA for the red LEDs, 15mA for the blue LEDs, and 30mA for the near-infrared LEDs, and this area allows all three types of LEDs to operate simultaneously in a certain comprehensive care mode, then the maximum power supply current for this area can be calculated as 6×20mA + 4×15mA + 4×30mA, resulting in 300mA. If the forehead area only has 4 blue LEDs and 4 red LEDs, the corresponding maximum power supply current is smaller. Therefore, the left cheek area should be identified as a higher load area during subsequent power layer routing, and the power supply branches for this area can be widened, the number of vias increased, or the power supply path shortened. This method of load calculation by area, by wavelength, and by driving current allows for the prediction in advance of which areas are more prone to voltage drop, insufficient brightness, or concentrated heat during the routing design phase. This provides a more accurate design basis for positive electrode routing compensation, power supply consistency detection, and subsequent area compensation control.

[0053] S43: Determine the corresponding positive electrode routing compensation parameters based on the path distance from each light-emitting area to the power input terminal and the maximum power supply load; Positive trace compensation parameters are used to correct power supply differences caused by varying power supply distances and loads in different light-emitting areas. In actual design, the location of the power input terminal can be determined first in the multilayer circuit board layout, and the trace path distance from the power input terminal to the power supply inlet of each light-emitting area or the positive pad of a critical LED can be calculated. This path distance is not a simple straight-line distance, but rather the actual conductive path traversed by the positive current in the power layer along the power supply bus, regional power supply branches, and vias to reach the LED pad. This path distance is then combined with the maximum power supply load obtained in the previous step for judgment. For example, if a certain area is close to the power input terminal and has a small number of LEDs, the line voltage drop is small, and a standard line width and number of vias can be used. If a certain area is located at the far end of the mask, with a long path distance, and contains many high-drive-current near-infrared LEDs or multi-band LEDs, the power supply current in this area is larger, and the resistance voltage drop caused by the long trace will be more significant, requiring stronger compensation.

[0054] Compensation parameters can be determined based on the relationship between line resistance and current load. The longer the trace and the larger the current, the easier it is for the voltage drop to increase. Therefore, the power supply impedance can be reduced by increasing the width of the positive trace, expanding the copper foil area, setting multiple parallel power supply branches, increasing the number of vias leading from the power layer to the top positive pad, using larger via diameters, or adjusting the branch connection positions. For example, if the trace length from the power input terminal in the left cheek area is 80mm and the maximum power supply load is 300mA, while the trace length in the forehead area is 35mm and the maximum power supply load is 120mA, then the left cheek area is more prone to voltage drop and brightness attenuation. The power supply branch in this area can be set to a wider copper foil trace, and two or more parallel vias can be set in this area to connect to the top positive pad; the forehead area can use narrower branch traces and a single set of vias. In this way, the positive electrode wiring compensation parameters are not set arbitrarily, but are designed differently according to the location of the area and the power demand. This allows the far-end area, the high-load area and the near-end low-load area to obtain closer terminal voltage and power supply capacity during actual operation, thereby reducing the difference in brightness between areas, reducing local heat generation, and improving the consistency and long-term reliability of the multi-area light emission of the beauty mask.

[0055] S44: Based on the positive trace compensation parameters, a positive power supply bus and a regional power supply branch are formed in the power layer; Based on the positive trace compensation parameters, a positive power supply bus and regional power supply branches are formed on the power layer. The positive power supply bus is used to draw the main power supply path from the power input terminal, while the regional power supply branches extend from the positive power supply bus to each light-emitting area. For areas with large loads or long distances, wider branch traces, shorter trace paths, or multi-point power supply methods can be used; for areas with small loads and close to the power input terminal, relatively conventional branch routing can be used. This can improve the power supply balance between different light-emitting areas without significantly increasing the overall thickness and structural complexity of the circuit board.

[0056] S45: Connect the regional power supply branch to the positive pad of the corresponding LED in the top signal trace layer through a via; By using vias to connect the regional power supply branch to the positive pad of the corresponding LED in the top-level signal trace layer, the interlayer conductivity structure of the multilayer circuit board is utilized to bring the positive power supply line located on the power layer to the mounting position of the LED in the top layer. Vias can be placed near the corresponding positive pad or at the location of a short trace connected to the positive pad. Electrical connection between the power layer and the top-level signal trace layer is achieved through via wall metallization or conductive filling. This method eliminates the need for numerous long positive power lines on the top layer, thereby reducing wiring congestion on the top-level signal trace layer and lowering the possibility of cross-interference between positive and signal traces.

[0057] S46: Perform power supply consistency testing on the multilayer circuit board after the positive terminal trace is formed, and select multilayer circuit boards or generate regional compensation parameters based on the test results.

[0058] During testing, the positive electrode pad voltage, regional voltage drop, operating current, or luminous brightness of different luminous areas can be measured under the same driving conditions and compared with a preset consistency range. If the power supply deviation of a circuit board exceeds the allowable range, it can be screened out to avoid local brightness abnormalities after subsequent assembly into a beauty mask. If the deviation is still within the adjustable range, regional compensation parameters can be generated to correct the driving current, PWM duty cycle, or lighting duration of the corresponding area in subsequent drive control. By combining detection feedback and compensation control, the luminous uniformity and batch consistency of the finished beauty mask can be further improved. Through the above processing, the positive electrode wiring is no longer simply connected according to the LED position, but a zoned power supply design is carried out in combination with regional load, line distance, and detection feedback. This reduces the impact of far-end voltage drop and uneven load on the luminous effect, allowing the beauty mask to form a light intensity closer to the expected light intensity in different facial areas, while improving the power supply stability, electrical safety, and finished product consistency of the multilayer circuit board.

[0059] In one embodiment, prior to performing COB dispensing encapsulation on the plurality of light-emitting LEDs, the method further includes: And a corresponding built-in control chip is set in each of the light-emitting LEDs; The data signal pins of each of the built-in control chips are connected in series, and the control signal pins of each of the built-in control chips are connected to the main controller, so that each LED can output one or more wavelengths of light within a preset wavelength range.

[0060] Specifically, before COB encapsulation of the LEDs, each LED contains a corresponding built-in control chip in a mini1618 package, enabling independent control of each LED. To reduce wiring complexity while maintaining control capability, the data signal pins of each built-in control chip are cascaded and connected in series. This allows data from the main controller to be transmitted step-by-step along a predetermined path to the corresponding built-in control chip in each light-emitting area, avoiding the redundancy and space occupation issues associated with laying separate data channels for each area. Simultaneously, the control signal pins of each built-in control chip are connected to the same main controller, enabling the main controller to perform timing and enable control on each chip, ensuring synchronization and stability of different light-emitting areas during operation. Furthermore, since the LEDs in each light-emitting area are electrically controlled by their corresponding built-in control chip, different control strategies issued by the main controller can be implemented to allow the LEDs in each area to selectively output one or more wavelengths within a preset wavelength range, achieving regionalized multi-wavelength light output. This step involves dividing the area and configuring the driving structure before encapsulation, so that the light-emitting structure after COB dispensing and encapsulation corresponds to different control units in terms of physical layout. This avoids complex electrical modifications after encapsulation, which not only improves the controllability of the production process, but also provides a structural basis for subsequent implementation of zoned phototherapy, differentiated care, and avoidance of excessive irradiation of specific wavelengths in non-target areas. At the same time, it helps to reduce wiring complexity and improve the overall reliability of the equipment.

[0061] In one embodiment, the step of arranging a plurality of light-emitting LEDs on the top signal trace layer and arranging the plurality of light-emitting LEDs toward the inner cover layer further includes: S51. Determine the target wavelength combination for each luminescent area based on the facial location and care needs corresponding to each luminescent area. First, align the luminous areas of the beauty mask with the locations on the human face, such as the forehead, left and right cheeks, around the mouth, around the eyes, and the sides of the nose. Then, determine the target wavelength combination based on the specific care needs of each area. The target wavelength combination refers to which wavelength ranges of LEDs are needed for a particular luminous area and the approximate ratio between each wavelength. For example, different needs such as oil control, acne treatment, repair, and soothing require different wavelength combinations due to their varying light effects. By determining the wavelength combination according to the facial locations first, you can avoid using a completely uniform LED arrangement across the entire mask, ensuring that the light output in different areas is more tailored to the skin's condition and the intended care purpose.

[0062] S52. Based on the target band combination, construct multiple light-emitting unit groups in each light-emitting region; Based on the predetermined target wavelength combinations for each luminous area, multiple luminous unit groups are further constructed within that area. Each luminous unit group can consist of two or more different wavelength LEDs, or it can be configured as a fixed combination according to a preset care mode. A luminous unit group is equivalent to the smallest luminous combination unit within the area that can be controlled independently or semi-independently. By repeatedly deploying multiple luminous unit groups within the same area, a more uniform multi-wavelength illumination effect can be achieved when the area is lit. This facilitates subsequent drive control, brightness adjustment, and care mode switching according to the unit group, reducing the wiring and control complexity caused by the dispersed control of individual LEDs.

[0063] S53. Adjust the arrangement density of LEDs of different wavelengths according to the sensitivity of each light-emitting area and the care needs. After determining the light-emitting unit group, it is necessary to adjust the arrangement density of LEDs of different wavelengths according to the sensitivity and care needs of different light-emitting areas. Arrangement density refers to the number of LEDs of a certain wavelength per unit area or the spacing between adjacent LEDs of the same wavelength. Areas with high sensitivity should not have excessively concentrated arrangement of LEDs of strong stimulation or high energy, while areas with strong care needs can appropriately increase the proportion of corresponding wavelength LEDs. The cheek area is relatively large, so the light-emitting LEDs corresponding to the second, third, and fourth wavelength ranges can be arranged alternately to make the multi-wavelength light coverage more uniform, and the first wavelength range LEDs can be set at intervals according to the needs of acne treatment or oil control. The forehead area has more obvious oil secretion, so the arrangement ratio of the first and third wavelength range LEDs can be increased to take into account both oil control and repair. The perioral area can increase the arrangement ratio of the third and fourth wavelength range LEDs to meet the needs of repair and soothing. The skin around the eyes and the nasal wings is sensitive and has a narrow structure space, so the arrangement density of the first wavelength range LEDs can be reduced and placed away from the edge of the eye opening to reduce discomfort caused by strong light directly hitting the eyes or sensitive areas. This zoning density adjustment can improve user comfort and safety while ensuring the effectiveness of care.

[0064] S54. Generate an LED mounting mapping table based on the installation location, band type, and control sequence of each LED; Based on the installation location, wavelength type, and control sequence of each LED, an LED mounting mapping table is generated. This mapping table maps the physical installation information and electrical control information of each LED, and includes information such as LED number, emitting area, coordinate position, wavelength type, positive and negative polarity, emitting unit group, control channel, and cascade sequence number. Since beauty masks contain a large number of LEDs with different wavelength types, relying solely on manual identification can easily lead to misalignment, mixed wavelengths, or incorrect control sequence. The mounting mapping table provides a unified basis for automatic placement, manual verification, and subsequent program control, ensuring consistency in circuit board design, LED installation, and control logic.

[0065] S55. According to the LED mounting mapping table, install LEDs of different wavelengths on the top signal trace layer; Following the LED mounting map, LEDs of different wavelengths are installed on the top signal trace layer. Specifically, based on the LED position, wavelength type, and direction recorded in the map, the corresponding wavelength LEDs are mounted onto their respective pads. The top signal trace layer is close to the inner cover layer, allowing the LEDs positioned behind this layer to emit light directly towards the inner cover layer, forming an irradiation path facing the skin. During installation, the mounting machine can automatically load and position the LEDs by reading the mounting map. Alternatively, during production inspection, the mapping map can be used to verify the consistency of LED wavelengths and positions. This ensures that LEDs of different wavelengths are accurately arranged according to the preset care areas, avoiding problems such as missing care wavelengths, excessive concentration, or mismatched control programs in certain areas due to incorrect mounting.

[0066] S56. Adjust the mounting direction of the LEDs according to the bending requirements of each light-emitting area; The mounting direction of the LEDs is adjusted according to the bending requirements of each light-emitting area. Facial masks need to conform to the three-dimensional contours of the face. Multi-layered circuit boards may have different bending directions and radii in areas such as the forehead, cheeks, nose, and chin. If all LEDs use the same mounting direction, uneven stress on the LED solder joints can easily occur when the circuit board is bent or when it is attached to the outer or inner cover layer, potentially leading to light polarization, warping, or decreased soldering reliability. Therefore, the long side, short side, or electrode direction of the LEDs can be adjusted according to the bending direction of the area, so that the force direction on the LED body and solder pads avoids the main bending stress direction as much as possible. In areas with large bends, the mounting direction of adjacent LEDs can also maintain a preset angle with the bending line to reduce the risk of stretching or compression of the package and solder joints. This treatment helps improve the mounting reliability of LEDs on flexible or curved circuit boards and makes the LED light emission direction more stably oriented towards the inner cover layer.

[0067] S57. Connect the built-in control chip according to the cascade sequence number in the LED chip mapping table.

[0068] Connecting the built-in control chip according to the cascading sequence number in the LED mounting map table involves cascading LEDs with built-in control chips according to a pre-set data transmission order. The cascading sequence number indicates the order in which control signals are transmitted among multiple LEDs. For example, control data is input from the first LED and then sequentially transmitted to subsequent LEDs. Each LED executes the corresponding brightness, color, or lighting sequence based on its own sequence number or the received data segment. Connecting the built-in control chip according to the mounting map table ensures that the physical installation order is consistent with the program control order. When the controller outputs control signals, it can accurately locate the specific light-emitting area, light-emitting unit group, and individual LED, avoiding misalignment issues such as the program lighting up the left cheek but actually lighting up the forehead. This method is particularly suitable for multi-band, multi-area beauty masks, reducing the number of individual leads, simplifying the top layer signal wiring, and improving the accuracy of zone control and care mode switching.

[0069] In summary, steps S51-S57 first determine the target wavelength combination based on the care needs of different facial areas, then construct light-emitting unit groups in each area, and adjust the arrangement density of LEDs of different wavelengths according to the sensitivity of the area; subsequently, the position, wavelength, direction, and control sequence of the LEDs are uniformly recorded through a mounting mapping table, allowing LEDs of different wavelengths to be installed on the top signal wiring layer; finally, the mounting direction is adjusted according to bending requirements, and the built-in control chip is connected according to the cascade sequence number, which ensures that the LED wavelength configuration, physical arrangement, and electrical control are consistent, improving the targeting, light emission uniformity, assembly reliability, and control accuracy of the beauty mask's zoned care.

[0070] In one embodiment, the COB encapsulation of the plurality of light-emitting LEDs includes: performing a first-stage pre-dispensing of adhesive on the light-emitting LEDs to form a limiting and covering structure around the light-emitting LEDs; performing a second-stage filler dispensing on the light-emitting LEDs after the first-stage pre-dispensing to form a continuous light-transmitting encapsulation layer on the surface of the light-emitting LEDs; wherein, according to the bending requirements of different areas of the corresponding face of the multilayer circuit board, the dispensing thickness, dispensing coverage area and / or colloid morphology of different areas are differentiated.

[0071] Specifically, in this embodiment, the COB encapsulation of the light-emitting LED is no longer a single-process, one-step molding process, but is divided into two stages for control, to balance the requirements of encapsulation reliability and flexible bonding. First, a pre-dispensing stage is performed. After the light-emitting LED is fixed and electrically connected, local dispensing is applied around the chip's periphery, forming a confining and covering structure around the chip. This structure serves two purposes: firstly, it provides initial fixation of the chip, preventing displacement or lifting during subsequent operations; secondly, it forms a barrier of a certain height around the chip edge, providing a constraint boundary for subsequent adhesive flow. The confining and covering structure formed by the pre-dispensing typically does not completely cover the chip's light-emitting surface, but is distributed around the chip's sidewalls. Its shape can be adjusted according to the chip size and arrangement density, for example, using a ring shape, a semi-ring shape, or a locally reinforced form, thereby ensuring the fixation effect while reducing shading of the light-emitting area. After the pre-dispensing is completed, a second stage of additional adhesive is performed. By adding encapsulating adhesive to the chip surface and its surrounding area, the adhesive spreads under the constraint of the confining structure, ultimately forming a continuous transparent encapsulation layer covering the chip's light-emitting surface. This transparent encapsulation layer not only seals and protects the chip, but also improves the uniformity of light emission to a certain extent, making the light softer.

[0072] Furthermore, considering that multilayer circuit boards need to conform to the curved surfaces of the face in actual use, and that the degree of bending varies in different areas such as the forehead, cheeks, nose, and around the eyes, differentiated control is implemented for different areas during the dispensing process. In areas with larger bending amplitudes, the dispensing thickness can be appropriately reduced or the coverage area can be decreased, allowing the encapsulation layer to maintain basic protective functions while possessing better flexibility and reducing stress concentration caused by bending. In relatively flat areas or areas requiring higher structural strength, the dispensing thickness can be appropriately increased or the coverage area expanded to improve the mechanical stability and durability of the encapsulation. In addition, the deposition morphology of the adhesive can be adjusted, such as controlling its edge transition shape or the degree of local bulging, so that the encapsulation layer exhibits different flexibility and support characteristics in different areas. This staged and regional dispensing encapsulation method not only improves the fixation reliability of the light-emitting LEDs on the flexible circuit board, but also ensures that the overall light-emitting structure remains stable under bending conditions, avoiding problems such as cracking and detachment caused by excessively hard or thick encapsulation layers, while taking into account both optical performance and structural adaptability, thus better meeting the needs of beauty masks in skin-contact applications.

[0073] In one embodiment, before placing the COB-coated multilayer circuit board between the outer and inner cover layers, the method further includes: aligning and pre-fixing the bonding surface of the inner cover layer, and aligning the light-transmitting area of ​​the inner cover layer with the arrangement area of ​​the light-emitting LEDs; during the bonding process between the multilayer circuit board and the inner cover layer, applying a bending adjustment to the multilayer circuit board that matches the curved surface of the mask, so that the multilayer circuit board forms a curved shape that conforms to the contour of the human face at different light-emitting areas; subsequently, the multilayer circuit board is fixedly connected to the outer cover layer to form a stable stacked structure.

[0074] Specifically, the inner cover layer's bonding surface is first aligned and pre-fixed. The inner cover layer is typically a light-transmitting structure that comes into direct contact with the skin. Its light-transmitting area needs to spatially correspond to the arrangement of the LEDs to ensure that the light emitted by the LEDs can effectively pass through without being blocked. In practice, alignment marks, positioning holes, or boundary references can be used to establish a preliminary alignment between the inner cover layer and the light-emitting area of ​​the multilayer circuit board during the initial assembly stage. Pre-fixation is then achieved through localized adhesive application, hot pressing, or clamping, thus preventing positional misalignment during subsequent bonding. When bonding the multilayer circuit board to the inner cover layer, a bending adjustment matching the mask's curvature is applied to the multilayer circuit board, creating a curved shape that conforms to the contours of the human face at different light-emitting areas. For example, a larger curvature bend is formed in the cheek area, while a more refined localized bonding shape is formed in the nose and around the eyes. This bending adjustment is not a simple overall bending, but rather a zoned adjustment based on the spatial shape of each area. This ensures that the position of the LED is as close as possible to the inner cover layer, thereby reducing gaps in the light propagation path and improving illumination uniformity. After bonding with the inner cover layer, the multilayer circuit board is then fixedly connected to the outer cover layer. The outer cover layer typically provides overall structural support and external protection, and it can be stably connected to the multilayer circuit board through snap-fitting, bonding, or hot pressing. Through this step-by-step assembly process—from aligning the inner cover layer and bonding the curved surface of the circuit board to fixing the outer cover layer—a stable layered relationship is formed between the light-emitting and supporting sides of the entire structure. This not only ensures the precise correspondence between the light-emitting and light-transmitting areas but also improves the fit and stability of the overall structure, avoiding uneven illumination or localized stress concentration caused by assembly deviations. This enhances the comfort and reliability of the beauty mask.

[0075] In summary, the packaging and manufacturing method for the beauty mask provided by this invention, by sequentially constructing a top-layer signal trace layer, a ground layer, a power layer, and an isolation layer on a multilayer circuit board substrate, allows the signal transmission path, power supply path, and return path to form a spatially independent layered structure. This ensures a compact circuit layout while reducing inter-layer interference and improving overall electrical stability. By forming corresponding traces on the ground layer and power layer and using vias to connect with the top-layer signal trace layer, the light-emitting LEDs can obtain control signals while having low-impedance power supply and return paths, which helps reduce voltage drop differences and improve light emission consistency. By directly placing the light-emitting LEDs... By placing the signal traces on the top layer and aligning them towards the inner cover layer, light can be output to the light-emitting side via a shorter path, reducing energy loss caused by obstruction from intermediate structures and thus improving light utilization efficiency. Furthermore, combining this with COB (Chip-on-Board) encapsulation allows the LED and circuit board to form an integrated structure, reducing the structural thickness of traditional packaging and increasing the light source density per unit area, thereby improving the uniformity of illumination coverage. During the final assembly stage, the encapsulated multi-layer circuit board is sandwiched between the outer and inner cover layers, allowing the inner cover layer to form a stable light-emitting interface while the outer cover layer provides structural support, thus achieving integrated integration of the light-emitting structure, circuit structure, and mask structure. This packaging and manufacturing method achieves both thinness and high integration in beauty masks while effectively improving power supply stability and light emission uniformity, further enhancing the reliability and comfort of the product during actual use.

[0076] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0077] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this invention are programs or code segments used to perform the required tasks. The programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0078] It should also be noted that the exemplary embodiments mentioned in this invention describe methods or systems based on a series of steps or apparatus. However, this invention is not limited to the order of the steps described above; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0079] The above description is merely a specific embodiment of the present invention. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A beauty mask based on a multilayer circuit board and COB packaging, characterized in that, include: An outer cover layer, an inner cover layer, and a multilayer circuit board disposed between the outer cover layer and the inner cover layer; The inner cover layer is located on the side of the multilayer circuit board closest to human skin and is used to form a light-emitting layer facing human skin; the outer cover layer is located on the side of the multilayer circuit board away from human skin; the outer cover layer is used to provide structural support for the multilayer circuit board. The multilayer circuit board includes a top-level signal routing layer, a ground layer, a power layer, and an isolation layer, arranged sequentially from the side closest to the inner cover layer to the side closest to the outer cover layer; wherein... The top signal trace layer is provided with a plurality of light-emitting LEDs encapsulated by COB adhesive. The plurality of light-emitting LEDs are arranged facing the inner cover layer so that the light emitted by the light-emitting LEDs is emitted through the inner cover layer and onto human skin; the top signal trace layer is used to realize the signal transmission of the light-emitting LEDs; The grounding layer is located on the side of the top signal trace layer away from the inner cover layer, and forms a grounding trace corresponding to the light-emitting LED; The power layer is located on the side of the ground layer away from the top signal trace layer, and forms a positive trace corresponding to the light-emitting LED; The isolation layer is located on the side of the power layer opposite to the ground layer, and no traces are provided on the isolation layer.

2. The beauty mask based on multilayer circuit board and COB packaging according to claim 1, characterized in that, The ground layer and the power layer of the multilayer circuit board are respectively connected to the top signal trace layer through vias; and the ground layer adopts a continuous copper-clad structure, the power layer adopts a uniform wiring structure, and the isolation layer has no traces, so that the power supply current of each LED tends to be uniform and electromagnetic interference is reduced.

3. The beauty mask based on multilayer circuit board and COB packaging according to claim 1, characterized in that, Each of the light-emitting LEDs is provided with a corresponding built-in control chip, wherein the data signal pins of each built-in control chip are connected in series, and the control signal pins are connected to the main controller.

4. The beauty mask based on multilayer circuit board and COB packaging according to claim 1, characterized in that, The beauty mask is divided into several light-emitting areas, including a first area and a second area covering the cheeks, a third area covering the area around the mouth, a fourth area covering the forehead, and a fifth area covering the area around the eyes and the sides of the nose.

5. The beauty mask based on multilayer circuit board and COB packaging according to any one of claims 1-4, characterized in that, The light-emitting LED includes LED chips capable of emitting light in different wavelength ranges. The different wavelength ranges include at least one or more of the following: a first wavelength range of 400-430nm, a second wavelength range of 560-610nm, a third wavelength range of 610-680nm, and a fourth wavelength range of 800-1100nm. The LED chips in each of the light-emitting regions are capable of outputting light in one or more of the first, second, third, and fourth wavelength ranges.

6. The beauty mask based on multilayer circuit board and COB packaging according to claim 5, characterized in that, The main controller is configured to selectively control the output of corresponding wavelength light in the corresponding luminescent area according to the skin problems corresponding to different luminescent areas, and limit the output of light within the first wavelength range in non-target luminescent areas, so as to reduce the excessive irradiation of blue-violet light in non-target areas of the human face.

7. The beauty mask based on multilayer circuit board and COB packaging according to claim 5, characterized in that, The main controller is configured to determine the corresponding care function according to different skin problems and control the LED chips in each light-emitting area to selectively output light of different wavelengths. Specifically, when used for acne treatment or oil control care, light within the first wavelength range is output at least; when used for whitening care, light within the second and third wavelength ranges is output at least; and when used for collagen-promoting care, light within the third and fourth wavelength ranges is output at least.

8. The beauty mask based on multilayer circuit board and COB packaging according to claim 5, characterized in that, The main controller is configured to determine corresponding care functions based on different skin problems and control the LED chips in each light-emitting area to emit light according to a preset combination and ratio of wavelengths. Specifically: for acne treatment, the LED chips are controlled to output a combination of light from a first wavelength range and a fourth wavelength range, with the output ratio of the corresponding wavelengths being 1:1; for oil control treatment, the LED chips are controlled to output light from a first wavelength range, with the output power of the light from the first wavelength range not exceeding a preset power threshold; for whitening treatment, the LED chips are controlled to output a combination of light from a second, third, and fourth wavelength range, with the output ratio of the corresponding wavelengths being 1:1:1 or increasing the output ratio of the second wavelength range; for collagen-promoting treatment, the LED chips are controlled to output a combination of light from a third and fourth wavelength range, with the output ratio of the corresponding wavelengths being 1:

1.

9. A method for packaging and manufacturing a beauty mask, characterized in that, The method is applied to the manufacture of a beauty mask as described in any one of claims 1-8, the method comprising: A circuit board substrate is obtained, and a top-layer signal trace layer, a ground layer, a power layer, and an isolation layer are formed based on the circuit board substrate to construct a multilayer circuit board; wherein, Signal traces for light-emitting LEDs are formed on the top-level signal trace layer; A ground trace corresponding to the light-emitting LED is formed on the ground layer, and the ground layer is connected to the top signal trace layer through vias; A positive electrode trace corresponding to the light-emitting LED is formed on the power layer, and the power layer is connected to the top signal trace layer through vias; A plurality of light-emitting LEDs are disposed on the top signal trace layer and arranged facing the inner cover layer. COB dispensing encapsulation is performed on multiple of the aforementioned light-emitting LEDs; A multilayer circuit board with COB dispensing encapsulation is placed between an outer cover layer and an inner cover layer. The top signal trace layer is located on the side closer to the inner cover layer, and the isolation layer is located on the side closer to the outer cover layer. The inner cover layer is located on the side of the multilayer circuit board closer to the human skin and forms a light-emitting layer facing the human skin. The outer cover layer is located on the side of the multilayer circuit board away from the human skin and forms structural support for the multilayer circuit board, thereby obtaining a beauty mask.

10. The packaging and manufacturing method of the beauty mask according to claim 9, characterized in that, Before performing COB dispensing encapsulation on the plurality of light-emitting LEDs, the method further includes: Each of the light-emitting chips is equipped with a corresponding built-in control chip; The data signal pins of the built-in control chips in each of the LEDs are connected in series, and the control signal pins of each of the built-in control chips are connected to the main controller.

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