A glue-filling type metal ultra-thin sensor and a manufacturing method thereof

Abstract

The application discloses a glue-filling type metal ultrathin sensor and a manufacturing method, and belongs to the technical field of sensors. The glue-filling type metal ultrathin sensor comprises a metal shell body with a mounting cavity, a photoelectric detection assembly arranged in the mounting cavity, the photoelectric detection assembly comprising a circuit board, a light-emitting and light-receiving assembly arranged on the circuit board, and a bound integrated chip arranged on the circuit board. The glue-filling type metal ultrathin sensor further comprises an optical lens mounted on the metal shell body and arranged opposite to the photoelectric detection assembly, an emission diaphragm arranged on an optical path of the light-emitting assembly and located between the light-emitting assembly and the optical lens, a metal shielding cover arranged on the periphery of the light-receiving assembly and connected with the circuit board, a tail plug assembly arranged on the metal shell body, a filling layer filled in the mounting cavity and covering the non-light-transmitting area of the photoelectric detection assembly, the metal shielding cover and the optical lens, and the optical lens is used for transmitting detection light emitted by the light-emitting assembly and reflection light reflected by a detection object. The application can improve sealing reliability and detection precision, and is beneficial to prolonging the service life.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology, and specifically relates to a potting-type ultrathin metal sensor and its manufacturing method. Background Technology

[0002] Photoelectric reflective sensors, as a non-contact detection device, are widely used in industrial automation, packaging inspection, and object recognition. Their basic principle is that a light-emitting component emits detection light, which is reflected from the surface of the object being measured and received by a light-receiving component, converting it into an electrical signal to detect the object. Currently, existing technologies typically use a plastic shell, employing O-rings and sealing rings for waterproofing and dustproofing. However, mechanical seals have poor reliability; after long-term use, the sealing rings are prone to aging and failure, allowing moisture, oil, and dust to enter the sensor, contaminating optical components and circuit boards, affecting the normal operation of the photoelectric detection component, and reducing the sensor's lifespan and detection accuracy. Furthermore, the light emitted by the light-emitting component is emitted directly without effective constraint, resulting in poor beam directionality and stray light, which can easily cause false triggering of the light-receiving component, affecting detection accuracy.

[0003] Therefore, it is necessary to provide a new technical solution to solve the above-mentioned technical problems. Summary of the Invention

[0004] The technical problem to be solved by this invention is the low sealing reliability, poor detection accuracy, and short service life of ultra-thin photoelectric sensors.

[0005] To address the aforementioned technical problems, this invention provides a potting-type ultrathin metal sensor. The potting-type ultrathin metal sensor includes a metal housing with a mounting cavity, a photoelectric detection component disposed within the mounting cavity, the photoelectric detection component including a circuit board, a light-emitting component and a light-receiving component disposed on the circuit board, and a bonded integrated chip disposed on the circuit board; it also includes an optical lens mounted on the metal housing and disposed opposite to the photoelectric detection component, an emission aperture disposed in the light-emitting path of the light-emitting component and located between the light-emitting component and the optical lens, and a metal shielding cover disposed around the light-receiving component and connected to the circuit board. A tail plug assembly on the metal housing is filled with a potting layer that encapsulates the non-transparent areas of the photoelectric detection component, the metal shield, and the optical lens within the mounting cavity, thereby forming an integrated sealed structure of the photoelectric detection component, the metal housing, and the tail plug assembly. The optical lens is used to transmit the detection light emitted by the light-emitting component and the reflected light after reflection by the detected object. The surface of the emission aperture facing the light-emitting component is formed with a matte finish. The tail plug assembly is used to seal the mounting cavity and to allow the sensor cable to be led out. The optical lens has a light-transmitting area for light transmission, which is located outside the potting layer.

[0006] Optionally, a positioning connection structure is provided between the optical lens and the circuit board. The positioning connection structure includes a plurality of positioning protrusions on the optical lens and a plurality of positioning holes on the circuit board. The positioning protrusions cooperate with the positioning holes. The optical lens and the circuit board are fixedly connected by heat fusion. After the positioning protrusions are inserted into the positioning holes, they are heated and melted and then cooled to form a fixed connection.

[0007] Optionally, an adhesive sealing layer is provided between the optical lens and the circuit board. The adhesive sealing layer is located in the bonding area between the optical lens and the circuit board. The adhesive sealing layer includes a UV adhesive layer, and / or the coating shape of the adhesive sealing layer is racetrack-shaped, so as to form a continuous sealing ring between the optical lens and the circuit board.

[0008] Optionally, the metal shell is manufactured using powder metallurgy, and the material of the metal shell is 316 stainless steel; and / or the metal shield is made of copper-nickel alloy.

[0009] Optionally, the potting layer is made of a semi-transparent thermoplastic polyurethane elastomer (TPU) material; the circuit board is provided with a status indicator light; the optical lens is provided with an indicator area corresponding to the status indicator light; wherein the potting layer is semi-transparent in the corresponding area between the status indicator light and the indicator area, so that the light emitted by the status indicator light is scattered through the potting layer and transmitted to the indicator area.

[0010] Optionally, the tail plug assembly includes a cable outlet tail plug and a cable sealing structure disposed on the cable outlet tail plug, the sensor cable passes through the cable sealing structure and is electrically connected to the circuit board; and / or at least one of the light-emitting component and the light-receiving component is electrically connected to the circuit board by a binding method.

[0011] Optionally, the potting-type ultra-thin metal sensor further includes a back cover, which is disposed on the metal housing, and the back cover and the metal housing are sealed together by dispensing adhesive.

[0012] According to another aspect of the present invention, the present invention also provides a method for manufacturing a potted metal ultrathin sensor. The method, used to manufacture the potted metal ultrathin sensor, further includes placing a light-emitting component, a light-receiving component, and a bonded integrated chip on a circuit board, and mounting an emitting aperture and a metal shield at corresponding positions on the circuit board. The emitting aperture has a matte surface facing the light-emitting component to form a photoelectric detection component. An optical lens is mounted to the circuit board via an adhesive sealing layer, and a racetrack-shaped sealing ring is formed between the optical lens and the circuit board to form a seal between the optical lens and the circuit board. The optical lens is sealed and its light-transmitting area is exposed. The photoelectric detection component with the optical lens is installed into the mounting cavity of the metal housing, and the tail plug assembly is installed on the metal housing to form a semi-finished product. The semi-finished product is placed in a potting mold, and potting material is injected into the metal housing according to a preset potting temperature and a preset potting pressure, so that the potting material fills the empty space in the mounting cavity, and the light-transmitting area of ​​the optical lens is exposed outside the potting material. The potting material is cured to form an integrated sealed structure of the photoelectric detection component, the metal housing, and the tail plug assembly.

[0013] Optionally, the step of mounting the optical lens to the circuit board via an adhesive sealing layer, forming a racetrack-shaped sealing ring between the optical lens and the circuit board to achieve a sealed fit between the optical lens and the circuit board, and exposing the light-transmitting area of ​​the optical lens includes: positioning the optical lens to the circuit board via a positioning connection structure, the positioning connection structure including a plurality of positioning protrusions on the optical lens and a plurality of positioning holes on the circuit board, the positioning protrusions being inserted into the positioning holes; applying UV adhesive to the bonding area between the optical lens and the circuit board to form the adhesive sealing layer; and / or heating the positioning protrusions to melt them, and after cooling, forming a fixed connection with the positioning holes.

[0014] Optionally, the potting material is a semi-transparent thermoplastic polyurethane elastomer (TPU) material; the preset potting temperature ranges from 60°C to 120°C; and the preset potting pressure ranges from 0.1 MPa to 0.5 MPa.

[0015] Beneficial effects: This invention provides a potting compound-type ultra-thin metal sensor. A photoelectric detection component is mounted within a mounting cavity of a metal housing. The photoelectric detection component includes a light-emitting component and a light-receiving component mounted on a circuit board. A bonded integrated chip is mounted on the circuit board. An emission aperture is positioned in the light-emitting path of the light-emitting component, between the light-emitting component and an optical lens. The surface of the emission aperture facing the light-emitting component is matte. The optical lens is mounted on the metal housing and positioned opposite the photoelectric detection component. The optical lens transmits the detection light emitted by the light-emitting component and the reflected light after reflection from the detected object. A metal shield is positioned around the light-receiving component and connected to the circuit board. A tail plug assembly is mounted on the metal housing, sealing the mounting cavity and providing a lead-out point for the sensor cable. A potting layer fills the interior of the mounting cavity and covers the non-transparent areas of the photoelectric detection component, the metal shield, and the optical lens, forming an integrated sealed structure. The optical lens has a transparent area for light transmission, located outside the potting layer. The interior of the metal casing provides mounting space for the photoelectric detection component. A light-emitting component on the circuit board emits detection light. An emitting aperture modulates the light emitted from the light-emitting component, and the matte surface of the emitting aperture facing the light-emitting component scatters the light. The detection light then passes through an optical lens to the external detection object. The reflected light, after being reflected by the detection object, is transmitted through the optical lens back into the mounting cavity and received by a light-receiving component on the circuit board. A bonded integrated chip is mounted on the circuit board to process the signal acquired by the light-receiving component. A metal shield surrounds the light-receiving component, and after being connected to the circuit board, it provides electromagnetic shielding to prevent external electromagnetic interference from affecting signal detection accuracy. Simultaneously, the tail plug assembly seals the opening of the mounting cavity in the metal casing, and the sensor cable is electrically connected. A potting layer fills the mounting cavity, covering the non-transparent areas of the photoelectric detection component, metal shield, and optical lens, forming an integrated sealed structure. This ensures that the photoelectric detection component, metal casing, and tail plug assembly form a sealed whole, preventing the intrusion of external moisture and dust. The transparent area of ​​the optical lens is located outside the potting layer, ensuring unobstructed light path. This achieves the technical effect of improving the sealing reliability and detection accuracy of ultra-thin photoelectric sensors, and is beneficial to extending their service life. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a potting-type ultrathin metal sensor provided in an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the optical lens structure in a potting-type ultrathin metal sensor provided in an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the circuit board structure in a potting-type ultrathin metal sensor provided in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the encapsulation mold in a potting-type ultrathin metal sensor provided in an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the tail plug assembly in a potting-type ultrathin metal sensor provided in an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the encapsulation layer in a potting-type ultrathin metal sensor provided in an embodiment of the present invention.

[0023] Figure 7 This is a schematic diagram of the metal housing in a potting-type ultrathin metal sensor provided in an embodiment of the present invention.

[0024] Figure 8 This is a schematic diagram of the structure of the back cover of a potting-type ultrathin metal sensor provided in an embodiment of the present invention.

[0025] Figure 9 A flowchart illustrating a method for manufacturing a potting-type ultrathin metal sensor according to an embodiment of the present invention. Detailed Implementation

[0026] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0027] To enable those skilled in the art to better understand the solutions of this application, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0028] In the embodiments of this application, "at least one" refers to one or more; "multiple" refers to two or more. In the description of this application, the terms "first," "second," "third," etc., are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0029] In this specification, references such as "one embodiment" or "some embodiments" mean that one or more embodiments of this application include the specific features, structures, or characteristics described in connection with that embodiment. Therefore, the terms "comprising," "including," "having," and variations thereof in this specification all mean "including but not limited to," unless otherwise specifically emphasized. It should be noted that in the embodiments of this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0030] It should be noted that, in the embodiments of the present invention, when a component is referred to as being "fixed to" another component, it can be directly on the other component or an intervening component may be present. When a component is considered to be "connected to" another component, it can be directly connected to the other component or an intervening component may be present simultaneously. When a component is considered to be "set on" another component, it can be directly set on the other component or an intervening component may be present simultaneously. Furthermore, in the embodiments of this application, "connection" can also be understood as an electrical connection; the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components. The terms "vertical," "horizontal," "left," "right," and similar expressions used in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the present invention.

[0031] An embodiment of this invention provides a potting compound type ultrathin metal sensor; please refer to [link to relevant documentation]. Figures 1 to 8 As shown, Figure 1 This is a schematic diagram of the structure of a potting compound type ultrathin metal sensor provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the optical lens structure in a potting-type ultrathin metal sensor provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the circuit board structure in a potting-type ultrathin metal sensor provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of the encapsulation mold in a potting-type ultrathin metal sensor provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of the tail plug assembly in a potting-type ultrathin metal sensor according to an embodiment of the present invention. Figure 6This is a schematic diagram of the encapsulation layer structure in a potting-type ultrathin metal sensor provided in an embodiment of the present invention. Figure 7 This is a schematic diagram of the metal housing structure in a potting-type ultrathin metal sensor provided in an embodiment of the present invention. Figure 8 This is a schematic diagram of the back cover structure of a potting-type ultra-thin metal sensor provided in an embodiment of the present invention. The potting-type ultra-thin metal sensor provided in this embodiment includes a metal housing 1, a photoelectric detection component 2, an optical lens 3, an emission aperture 4, a metal shield 5, a tail plug assembly 6, and a potting layer 7. The metal housing 1 has a mounting cavity, and the photoelectric detection component 2 is disposed inside the mounting cavity. The photoelectric detection component 2 includes a circuit board 21, a light-emitting component, a light-receiving component, and a bonded integrated chip. The light-emitting component, the light-receiving component, and the bonded integrated chip are disposed on the circuit board 21. The optical lens 3 is mounted on the metal housing 1 and is positioned opposite to the photoelectric detection component 2. The optical lens 3 is used to transmit the detection light emitted by the light-emitting component and the reflected light after reflection by the detected object. The emission aperture 4 is disposed in the light-emitting path of the light-emitting component and is located between the light-emitting component and the optical lens 3. The surface of the emission aperture 4 facing the light-emitting component is formed with a matte finish. The metal shield 5 is disposed around the light-receiving component and is connected to the circuit board 21. A tail plug assembly 6 is mounted on the metal housing 1. The tail plug assembly 6 seals the mounting cavity and provides a lead-out point for the sensor cable 101. A potting layer 7 fills the interior of the mounting cavity and covers the non-transparent areas of the photoelectric detection assembly 2, the metal shield 5, and the optical lens 3, forming an integrated sealed structure. The optical lens 3 has a light-transmitting area for light transmission, located outside the potting layer 7.

[0032] The length and width of the circuit board 21 match the length and width of the mounting cavity, respectively. The circuit board 21 is fixed to the bottom of the mounting cavity using adhesive. A light-emitting component is disposed on the surface of the circuit board 21 near the optical lens 3. This component may include an infrared emitting diode, such as one with a surface-mount package. A light-receiving component is disposed on the circuit board 21, located beside the light-emitting component. This component may include a photodiode, such as one with a surface-mount package. A bonded integrated chip is disposed on the circuit board 21, located in the area between the light-receiving and light-emitting components. This chip may integrate signal amplification circuitry, filtering circuitry, and analog-to-digital conversion circuitry. The bonded integrated chip can be directly soldered to the corresponding pads on the circuit board 21 using bonding wires.

[0033] The optical lens 3 can be mounted on the metal housing 1 and positioned opposite the photoelectric detection component 2. The optical lens 3 has a flat rectangular parallelepiped structure, with a raised biconvex hemispherical structure in its central region for light transmission. This central region can constitute a light-transmitting area. The emission aperture 4 can be positioned in the light-emitting path of the light-emitting component and located between the component and the optical lens 3. The emission aperture 4 can also be made of stainless steel sheet using laser cutting. It is fixed to the circuit board 21 and positioned in the light path between the component and the optical lens 3. The surface of the emission aperture 4 facing the light-emitting component is formed with a matte finish through sandblasting or chemical etching.

[0034] The metal shield 5 is disposed around the light-receiving component and connected to the circuit board 21. The metal shield 5 can be made of nickel-plated phosphor bronze or galvanized steel sheet through a stamping and bending process. The metal shield 5 can have a rectangular frame structure. The bottom edge of the metal shield 5 has downwardly extending connecting feet, which are soldered to the grounding pads on the circuit board 21. The tail plug body can be made of nylon or engineering plastic through injection molding. The sensor cable 101 can include a multi-core shielded cable. The multi-core shielded cable passes through the outside of the tail plug body, and the core wires pass through the central through-hole of the tail plug body and are led out into the mounting cavity. The ends of each core wire are soldered to the corresponding pads on the circuit board 21.

[0035] The potting layer 7 fills the mounting cavity and covers the non-transparent areas of the photoelectric detection component 2, the metal shield 5, and the optical lens 3. The potting layer 7 can also be formed using a thermoplastic polyurethane elastomer through a liquid encapsulation process. The main body of the potting layer 7 fills the gap area within the mounting cavity from the upper surface of the circuit board 21 to the lower surface of the non-transparent area of ​​the optical lens 3. The potting layer 7 also fills the gap between the metal shield 5 and the inner wall of the mounting cavity. After complete curing, the potting layer 7 forms a dense solid structure, integrating the photoelectric detection component 2, the metal housing 1, and the tail plug assembly 6 into an integrated sealed structure, isolating the interior of the mounting cavity from the external environment. The transparent area of ​​the optical lens 3 is completely exposed on the outer surface of the potting layer 7, without any potting material adhering to it, ensuring unobstructed light transmission.

[0036] In this embodiment, a photoelectric detection component 2 is disposed within the mounting cavity of the metal housing 1. The light-emitting component and the light-receiving component of the photoelectric detection component 2 are respectively disposed on a circuit board 21. A bonded integrated chip is disposed on the circuit board 21. An emission aperture 4 is disposed in the light-emitting path of the light-emitting component and is located between the light-emitting component and the optical lens 3. The surface of the emission aperture 4 facing the light-emitting component is matte. The optical lens 3 is mounted on the metal housing 1 and is positioned opposite to the photoelectric detection component 2. The optical lens 3 is used to transmit the detection light emitted by the light-emitting component and the reflected light after reflection by the detected object. A metal shield 5 is disposed around the light-receiving component and is connected to the circuit board 21. A tail plug assembly 6 is disposed on the metal housing 1. The tail plug assembly 6 is used to seal the mounting cavity and provides a lead-out point for the sensor cable 101. The potting layer 7 fills the interior of the mounting cavity and covers the non-transparent areas of the photoelectric detection component 2, the metal shield 5, and the optical lens 3, forming an integrated sealed structure of the photoelectric detection component 2, the metal housing 1, and the tail plug assembly 6. The optical lens 3 has a light-transmitting area for light transmission, located outside the potting layer 7. Thus, the interior of the metal housing 1 provides mounting space for the photoelectric detection component 2. The light-emitting component mounted on the circuit board 21 emits detection light, and the emission aperture 4 modulates the light emitted from the light-emitting component. The matte surface of the emission aperture 4 facing the light-emitting component scatters the light, which is then transmitted through the optical lens 3 to the external detection object. The reflected light, after being reflected by the detection object, is transmitted through the optical lens 3 back into the mounting cavity and received by the light-receiving component mounted on the circuit board 21. A bonded integrated chip is mounted on the circuit board 21 to process the signals acquired by the light-receiving component. The metal shield 5 surrounds the light-receiving component. After being connected to the circuit board 21, the metal shield 5 provides electromagnetic shielding to the light-receiving component, preventing external electromagnetic interference from affecting signal detection accuracy. Simultaneously, the tail plug assembly 6 seals the mounting cavity opening of the metal housing 1, and the sensor cable 101 leads out to achieve electrical connection. The potting layer 7 fills the mounting cavity, covering the non-transparent areas of the photoelectric detection assembly 2, the metal shield 5, and the optical lens 3, forming an integrated sealed structure. This ensures that the photoelectric detection assembly 2, the metal housing 1, and the tail plug assembly 6 form a sealed whole, preventing the intrusion of external moisture and dust. The transparent area of ​​the optical lens 3 is located outside the potting layer 7, ensuring unobstructed light path. This achieves the technical effect of improving the sealing reliability and detection accuracy of the ultra-thin photoelectric sensor, and extending its service life.

[0037] In one implementation, a positioning connection structure is provided between the optical lens 3 and the circuit board 21. This structure includes multiple positioning protrusions and multiple positioning holes. The positioning protrusions are disposed on the optical lens 3, and the positioning holes are disposed on the circuit board 21. The positioning protrusions and positioning holes cooperate with each other. The optical lens 3 and the circuit board 21 are fixedly connected by thermal fusion. After the positioning protrusions are inserted into the positioning holes, they are melted by heating and then cooled to form a fixed connection. For example, three positioning protrusions can be evenly distributed on the outer periphery of the surface of the optical lens 3 closest to the circuit board 21. Each positioning protrusion is a cylindrical solid protrusion. Three corresponding positioning holes can be opened on the surface of the circuit board 21 closest to the optical lens 3 and located on the periphery of the light-receiving component. The diameter of the positioning holes can be slightly larger than the outer diameter of the positioning protrusions to facilitate insertion of the positioning protrusions. The specific implementation of the thermofusion fixing connection between the optical lens 3 and the circuit board 21 can be as follows: During assembly, the three positioning protrusions are first aligned with the three positioning holes respectively. Then, the optical lens 3 is pushed in a direction perpendicular to the circuit board 21 so that the positioning protrusions are inserted into the corresponding positioning holes. Subsequently, the end of the positioning protrusion located outside the positioning hole is heated by a thermofusion welding device to melt the end of the positioning protrusion. The molten polycarbonate material solidifies during the subsequent cooling process, forming a firm mechanical interlocking connection with the inner wall of the positioning hole, thereby fixing the optical lens 3 to the circuit board 21. This restricts the optical lens 3 from the circuit board 21 in the three translational directions of X, Y, and Z, as well as the rotational movement around the X and Y axes. This helps to improve the alignment accuracy of the axis of the light-transmitting area of ​​the optical lens 3 with the optical axis of the light-emitting component and the light-receiving component. At the same time, it can withstand the shrinkage stress generated by the potting layer 7 during the curing process and the vibration and impact of the sensor during use, preventing the optical lens 3 from loosening or shifting.

[0038] In some embodiments, an adhesive sealing layer 9 is provided between the optical lens 3 and the circuit board 21. The adhesive sealing layer 9 is disposed in the bonding area between the optical lens 3 and the circuit board 21. The adhesive sealing layer 9 includes a UV adhesive layer, and / or the coating shape of the adhesive sealing layer 9 is racetrack-shaped 91, so that a continuous sealing ring is formed between the optical lens 3 and the circuit board 21. The racetrack-shaped 91 can refer to a trajectory including two arc segments and two U-shaped segments, with the two U-shaped segments arranged opposite each other, and the two ends of each U-shaped segment connected to the two arc segments respectively. The adhesive sealing layer 9 can be made of UV-curable adhesive. The adhesive sealing layer 9 is coated on the peripheral area of ​​the lower surface of the optical lens 3 near the side of the circuit board 21. The shape of the adhesive sealing layer 9 is racetrack-shaped 91, which is disposed around the outer periphery of the light-transmitting area of ​​the optical lens 3. The side of the circuit board 21 near the optical lens 3 has adhesive pads in the area corresponding to the racetrack-shaped 91, and UV adhesive can be applied to the adhesive pads. During assembly, the optical lens 3 coated with UV adhesive is aligned and installed onto the metal housing 1, with the adhesive sealing layer 9 positioned between the optical lens 3 and the circuit board 21. The UV adhesive is then rapidly cured to form the adhesive sealing layer 9, which provides both bonding and sealing. The adhesive sealing layer 9 bonds and fixes the outer periphery of the optical lens 3 to the circuit board 21, while simultaneously forming a continuous, uninterrupted sealing ring structure between them. Alternatively, the adhesive sealing layer 9 can also be made of two-component epoxy resin or silicone, with a similar racetrack-shaped coating 91, forming a continuous sealing ring around the outer periphery of the light-transmitting area. The racetrack-shaped coating 91 allows the adhesive sealing layer 9 to form a continuous, uninterrupted sealing band along the entire outer periphery of the optical lens 3, preventing sealing gaps or adhesive layer breakage at the right-angled edges of the optical lens 3. This effectively prevents the potting layer 7 from seeping into the light-transmitting area through the gap between the optical lens 3 and the circuit board 21 during the filling process, thus affecting the light transmission performance. At the same time, the adhesive sealing layer 9 fixes the optical lens 3 to the circuit board 21 to prevent the optical lens 3 from shifting due to vibration or impact during use, thus achieving optical path alignment accuracy.

[0039] As an example, the metal housing 1 is manufactured using powder metallurgy, and the material of the metal housing 1 is 316 stainless steel; and / or the metal shielding cover 5 is made of copper-nickel alloy. The powder metallurgy process for manufacturing the metal housing 1 can include first using an atomization powdering process to produce powder particles from 316 stainless steel; then loading the powder particles into a mold cavity adapted to the shape of the mounting cavity, and pressing them using a cold isostatic pressing process to form a green blank similar in shape to the final shape of the metal housing 1. The green blank is then sent to a vacuum sintering furnace for sintering, causing metallurgical bonding between the stainless steel powder particles to form a dense metal structure. Finally, the sintered blank is precision machined, which helps to further reduce the overall thickness of the sensor while ensuring structural strength, achieving ultra-thin wall thickness. The metal shielding cover 5 can be made of copper-nickel alloy, such as forming a rectangular frame structure from the copper-nickel alloy using a stamping process, and then electroplating a layer of nickel on the frame surface. As an alternative implementation, the metal housing 1 can also be made of 316L stainless steel powder through powder metallurgy, and the metal shielding cover 5 can also be made of copper-nickel alloy, which can more effectively suppress the influence of external electromagnetic interference on the light receiving component and the bonded integrated chip, reduce signal noise, and improve signal detection accuracy.

[0040] In some embodiments, the potting layer 7 is made of a semi-transparent thermoplastic polyurethane elastomer (TPU) material. TPU material has higher flexibility and better impact resistance, effectively absorbing the mechanical impact energy generated by drops, collisions, or vibrations during sensor use. This reduces the risk of damage to the brittle components of the internal photoelectric detection assembly 2 from impact loads, thus extending the sensor's lifespan under harsh conditions. A status indicator light is provided on the circuit board 21, and an indicator area corresponding to the status indicator light is provided on the optical lens 3. The corresponding area of ​​the potting layer 7 between the status indicator light and the indicator area is semi-transparent, allowing the light emitted from the status indicator light to be scattered through the potting layer 7 and transmitted to the indicator area. The potting layer 7 is made of thermoplastic polyurethane elastomer material. The status indicator light can be mounted on the circuit board 21 at a reserved pad location next to the bonded integrated chip. The corresponding area of ​​the potting layer 7 between the status indicator light and the indicator area is made of semi-transparent TPU material. This semi-transparent area forms a cylindrical optical path channel, allowing the status indicator light to be directionally transmitted to the indicator area. When the status indicator light is powered on, the light is scattered by the semi-transparent area of ​​the potting layer 7 and reaches the indicator area. The light spot emitted by the indicator area can be observed from the outside of the sensor, indicating that the sensor is in normal working condition.

[0041] In some embodiments, the tail plug assembly 6 includes a cable exit tail plug 61 and a cable sealing structure 62. The cable sealing structure 62 is disposed on the cable exit tail plug 61. The sensor cable 101 passes through the cable sealing structure 62 and is electrically connected to the circuit board 21, and / or at least one of the light-emitting component and the light-receiving component is electrically connected to the circuit board 21 by a bonding method. The cable sealing structure 62 may include an integral elastic seal, the main body of which is a cylindrical rubber block with a plurality of through holes corresponding to the number of core wires through the center along the axial direction. Each core wire of the sensor cable 101 passes through the corresponding through hole. The light-emitting component may be a surface-mount infrared emitting diode, which is ultrasonically ball-bonded to the corresponding pad on the circuit board 21 through a bonding wire. The light-receiving component may be a photodiode, which is also ultrasonically ball-bonded to the corresponding pad on the circuit board 21 through a bonding wire. As an alternative embodiment, at least one of the light-emitting component and the light-receiving component may also be electrically connected to the circuit board 21 by SMT surface-mount soldering; the elastic seal may also be made of fluororubber material to adapt to higher temperature environments. By bonding at least one of the light-emitting component and the light-receiving component to the circuit board 21, the LED pins and bracket structure can be eliminated, the optical path can be shortened, which is beneficial for the ultra-thin sensor. It also has lower parasitic inductance and a shorter signal transmission path. The weak signal output by the light-receiving component is transmitted to the bonded integrated chip through the bonding line with less loss, which is beneficial for improving signal integrity.

[0042] In some embodiments, the glue-filled ultra-thin metal sensor provided by this invention also includes a back cover 10, which is disposed on a metal housing 1 and sealed to the metal housing 1 by dispensing adhesive. The back cover 10 can be made of 304 stainless steel sheet by stamping, such as having a flat rectangular structure, and its external dimensions match the outer contour of the metal housing 1. The specific method of dispensing sealing connection can be to use a single-component epoxy resin or silicone adhesive, and to continuously apply a ring of adhesive along a circular trajectory on the upper surface of the dispensing positioning protrusion of the metal housing 1 using a precision dispensing device, and then align and position the back cover 10 on the metal housing 1; subsequently, the adhesive layer is cured by room temperature curing or heat curing, so that a strong adhesive and sealing connection is formed between the back cover 10 and the metal housing 1. As an alternative embodiment, the back cover 10 can also be made of polymer material by injection molding, and the dispensing method can also be UV adhesive, which is cured rapidly by ultraviolet light.

[0043] To provide a detailed explanation of the manufacturing method of the potting-type ultrathin metal sensor provided by the present invention, the above embodiments have described a potting-type ultrathin metal sensor in detail. Based on the same inventive concept, this application also provides a manufacturing method of the potting-type ultrathin metal sensor, as detailed in the following embodiments.

[0044] Please see Figure 4 and Figure 9 , Figure 4 This is a schematic diagram of the encapsulation mold in a potting-type ultrathin metal sensor provided in an embodiment of the present invention. Figure 9 This is a flowchart illustrating a method for manufacturing a potting-type ultrathin metal sensor according to an embodiment of the present invention. The present invention provides a method for manufacturing a potting-type ultrathin metal sensor, the method being used to manufacture the aforementioned potting-type ultrathin metal sensor, and further includes the following steps: In step S100, the light-emitting component, the light-receiving component, and the bonded integrated chip are placed on the circuit board 21, and the emission aperture 4 and the metal shield 5 are installed at the corresponding positions on the circuit board 21. The emission aperture 4 has a matte surface facing the light-emitting component to form the photoelectric detection component 2. Specifically, the light-emitting component can be a surface-mount infrared emitting diode, soldered to the pad array on the circuit board 21 using SMT reflow soldering. The light-receiving component is a surface-mount photodiode, soldered to another pad array on the circuit board 21 using SMT reflow soldering. The bonded integrated chip can integrate a transimpedance amplifier, filter, and analog-to-digital converter. It is directly connected to the corresponding pad on the circuit board 21 and the signal output terminal of the photodiode through bonding wires, such as gold wires, to realize the conversion and preliminary processing of analog signals to digital signals. The emitting aperture 4 can be made of stainless steel sheet by laser precision cutting, and is in the shape of a rectangular sheet. The emitting aperture 4 can be fixed to the position on the circuit board 21 corresponding to the position between the light-emitting component and the subsequent optical lens 3 by conductive adhesive. A rectangular light-passing hole is opened on it corresponding to the center of the optical axis of the light-emitting component. The surface of the emitting aperture 4 facing the light-emitting component can be sandblasted to form a matte surface, and the surface of the other side facing away from the light-emitting component can be chemically polished to a mirror state. The metal shield 5 can be formed by stamping, bending and welding of nickel-plated phosphor bronze sheet into a rectangular frame structure. The four corners can be provided with downward bent connecting feet, which are soldered to the grounding pad of the circuit board 21 by reflow soldering to form a local electromagnetic shield for the light receiving component and the signal input terminal area of ​​the bonded integrated chip.

[0045] Step S200: The optical lens 3 is mounted on the circuit board 21 through the adhesive sealing layer 9, and a racetrack-shaped sealing ring 91 is formed between the optical lens 3 and the circuit board 21 to form a sealed fit between the optical lens 3 and the circuit board 21, and the light-transmitting area of ​​the optical lens 3 is exposed. The process involves mounting the optical lens 3 to the circuit board 21 via an adhesive sealing layer 9, forming a racetrack-shaped sealing ring 91 between the optical lens 3 and the circuit board 21 to create a sealed fit. Exposing the light-transmitting area of ​​the optical lens 3 includes positioning the optical lens 3 to the circuit board 21 via a positioning connection structure. The positioning connection structure includes multiple positioning protrusions on the optical lens 3 and multiple positioning holes on the circuit board 21, with the positioning protrusions inserted into the positioning holes. UV adhesive is applied to the bonding area between the optical lens 3 and the circuit board 21 to form the adhesive sealing layer 9. And / or the positioning protrusions are heated to melt them, and after cooling, they form a fixed connection with the positioning holes.

[0046] Specifically, the optical lens 3 can be injection molded from optical-grade polycarbonate material, such as having a flat rectangular structure with a central area forming a biconvex hemispherical light-transmitting region. Three positioning protrusions, each a solid cylindrical protrusion, can be evenly distributed along the length of the lower surface of the optical lens 3. Three positioning holes are machined on the upper surface of the circuit board 21 corresponding to the positions of these three positioning protrusions. During installation, the three positioning protrusions of the optical lens 3 are first aligned with the three positioning holes on the circuit board 21, maintaining a small deviation between the center of the light-transmitting region and the optical axis of the light-emitting component. Then, the optical lens 3 is pushed along the Z-axis perpendicular to the circuit board 21, inserting the three positioning protrusions into their corresponding positioning holes. Afterward, the exposed ends of the three positioning protrusions are heated using a hot air welding tool until the PC material ends melt. After heating stops, the molten PC material cools and solidifies naturally, forming a tight interference fit with the inner wall of the positioning holes, firmly fixing the optical lens 3 to the circuit board 21. Then, UV-curable acrylic adhesive is applied to the outer periphery of the lower surface of the optical lens 3 using a precision dispensing system in a continuous racetrack-shaped 91 adhesive line. The adhesive is then irradiated with a UV curing lamp to fully polymerize and cure, forming an adhesive sealing layer 9. This creates a continuous sealing ring between the optical lens 3 and the circuit board 21, preventing relative displacement from causing optical path deviation and preventing subsequent potting materials from seeping into the micro-gap between the lens and the circuit board 21.

[0047] Step S300: The photoelectric detection component 2 with the optical lens 3 installed is installed into the mounting cavity of the metal housing 1, and the tail plug component 6 is installed on the metal housing 1 to form a semi-finished product. Specifically, the metal housing 1 can be made of SUS304 cold-rolled steel sheet through multi-station stamping, bending, and laser welding processes, and the overall structure can be a flat rectangular box. During installation, first align the circuit board 21 of the photoelectric detection component 2 with the entrance direction of the mounting cavity, making the long side of the circuit board 21 parallel to the long side of the mounting cavity. Position the light-emitting component and the light-receiving component facing the open end of the circuit board 21 away from the back cover 10. Then, smoothly push the photoelectric detection component 2 into the mounting cavity along the Z-axis until the back of the circuit board 21 is completely flush with the bottom inner wall of the mounting cavity. Next, remove the tail plug assembly 6, and pass each core wire of the sensor cable 101 sequentially through the elastic seal inside the tail plug assembly 6, such as silicone rubber. After the tail plug assembly 6 is installed in place, the ends of the core wires of the sensor cable 101 are suspended inside the mounting cavity, ready for subsequent soldering to the circuit board 21. After completing the above operations, a semi-finished product will be formed. The semi-finished product is a metal shell 1 with a photoelectric detection component 2 with an optical lens 3 and a tail plug component 6. The core wire of the sensor cable 101 has been led out, but the cavity has not yet been filled with potting material, so that uniform empty space can be reserved for subsequent potting and filling.

[0048] In step S400, the semi-finished product is placed in the potting mold 102, and potting material is injected into the metal shell 1 according to the preset potting temperature and preset potting pressure, so that the potting material fills the empty space in the mounting cavity, and the light-transmitting area of ​​the optical lens 3 is exposed outside the potting material. The potting material is a semi-transparent thermoplastic polyurethane elastomer (TPU); the preset potting temperature ranges from 60°C to 120°C; and the preset potting pressure ranges from 0.1 MPa to 0.5 MPa.

[0049] Specifically, the potting mold 102 has cavities corresponding to the bottom outline of the metal shell 1 of the semi-finished product and the exposed part of the tail plug assembly 6. The potting material can be thermoplastic polyurethane elastomer. During the potting process, the tail plug assembly 6 of the semi-finished product is first placed on the base module with the end facing down or horizontally, the open end of the metal shell 1 facing up, and the light-transmitting area of ​​the optical lens 3 aligned with the clearance opening of the potting mold 102. Then, the injection molding machine is started to add TPU granules into the barrel. The potting pressure ranges from 0.1MPa to 0.5MPa through the screw or plunger injection system, and the molten TPU with a potting temperature range of 60℃ to 120℃ is injected into the mounting cavity of the metal shell 1 from the lead hole at the end of the tail plug assembly 6 or directly. This allows the TPU melt to fill the bottom of the mounting cavity, that is, the gap between the circuit board 21 and the bottom of the shell, as well as the empty space of the metal shield 5, the emitting aperture 4, and the circuit board 21, and finally reach the area around the non-light-transmitting area of ​​the optical lens 3. For example, using an upper limit temperature of 110°C during the initial injection stage ensures optimal TPU melt flow, facilitating the filling of small gaps. During the holding pressure stage, the temperature is reduced to a lower limit of 60°C to minimize TPU thermal stress. An upper limit pressure of 0.5 MPa is used during the filling stage for rapid filling, and this is rapidly reduced to a lower limit pressure of 0.1 MPa during the holding pressure stage to reduce internal stress. Once the TPU melt is full, the system switches to the holding pressure stage to compensate for TPU cooling and volume shrinkage. Afterward, the filled sensor blank is removed, and surface overflow is cleaned. Step S500: The potting material is cured to form an integrated sealing structure of the photoelectric detection component 2, the metal housing 1 and the tail plug component 6.

[0050] Specifically, after step S400 is completed, the mounting cavity of the metal housing 1 is filled with molten TPU, and the light-transmitting area of ​​the optical lens 3 is exposed to the outside. The infused sensor semi-finished product can then be removed from the potting mold 102 and placed horizontally at ambient temperature to allow the TPU surface, i.e., the part exposed to air, to initially solidify and form a hard shell. At this time, the interior of the TPU is still in a transitional region between a highly elastic state and a viscous flow state. During this stage, the sensor is kept slightly clamped in the fixture to prevent gaps or sensor deformation caused by TPU cooling and shrinkage. The pre-cooled and shaped sensor is then transferred to a walk-in constant temperature and humidity chamber, where a slow, stepped cooling process is set up to allow the TPU molecular chains to complete volume shrinkage in a relaxed state, avoiding microcracks or interface debonding caused by stress concentration due to sudden temperature changes. The sensor, after stepped cooling, is then transferred to a forced air convection oven, allowing the TPU to continue molecular chain rearrangement and secondary crystallization in a stress-relaxed state, improving dimensional stability and mechanical strength. After that, turn off the power to the oven and let it cool naturally to room temperature, which is the cooling and setting process.

[0051] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A potting-type ultrathin metal sensor, characterized in that, The potting-type ultra-thin metal sensor includes a metal housing with a mounting cavity, a photoelectric detection component disposed within the mounting cavity, the photoelectric detection component including a circuit board, a light-emitting component and a light-receiving component disposed on the circuit board, and a bonded integrated chip disposed on the circuit board; it also includes an optical lens mounted on the metal housing and disposed opposite to the photoelectric detection component, an emission aperture disposed on the light-emitting component and located between the light-emitting component and the optical lens, a metal shield disposed around the light-receiving component and connected to the circuit board, and a tail plug assembly disposed on the metal housing. A potting layer is filled within the mounting cavity and covers the non-transparent areas of the photoelectric detection component, the metal shield, and the optical lens, so that the photoelectric detection component, the metal housing, and the tail plug assembly form an integrated sealed structure; the optical lens is used to transmit the detection light emitted by the light-emitting component and the reflected light after being reflected by the detection object; the surface of the emission aperture facing the light-emitting component is formed with a matte finish; the tail plug assembly is used to seal the mounting cavity and to allow the sensor cable to be led out; wherein the optical lens has a light-transmitting area for light transmission, and the light-transmitting area is located outside the potting layer.

2. The potting-type ultrathin metal sensor according to claim 1, characterized in that: A positioning connection structure is provided between the optical lens and the circuit board. The positioning connection structure includes a plurality of positioning protrusions on the optical lens and a plurality of positioning holes on the circuit board. The positioning protrusions cooperate with the positioning holes. The optical lens and the circuit board are fixedly connected by heat fusion. After the positioning protrusions are inserted into the positioning holes, they are heated and melted and then cooled to form a fixed connection.

3. The potting-type ultrathin metal sensor according to claim 1, characterized in that: An adhesive sealing layer is provided between the optical lens and the circuit board. The adhesive sealing layer is located in the bonding area between the optical lens and the circuit board. The adhesive sealing layer includes a UV adhesive layer, and / or the coating shape of the adhesive sealing layer is racetrack-shaped, so as to form a continuous sealing ring between the optical lens and the circuit board.

4. The potting-type ultrathin metal sensor according to claim 1, characterized in that: The metal shell is made using powder metallurgy, and the material used to make the metal shell is 316 stainless steel; and / or the metal shielding cover is made of copper-nickel alloy.

5. The potting-type ultrathin metal sensor according to claim 1, characterized in that: The potting layer is made of a semi-transparent thermoplastic polyurethane elastomer (TPU) material; the circuit board is provided with a status indicator light; the optical lens is provided with an indicator area corresponding to the status indicator light; wherein the potting layer is semi-transparent in the corresponding area between the status indicator light and the indicator area, so that the light emitted by the status indicator light is scattered through the potting layer and transmitted to the indicator area.

6. The potting-type ultrathin metal sensor according to claim 1, characterized in that: The tail plug assembly includes a cable outlet tail plug and a cable sealing structure disposed on the cable outlet tail plug. The sensor cable passes through the cable sealing structure and is electrically connected to the circuit board. And / or at least one of the light-emitting component and the light-receiving component is electrically connected to the circuit board by a binding method.

7. The potting-type ultrathin metal sensor according to claim 1, characterized in that, The potting-type ultra-thin metal sensor also includes a back cover, which is disposed on the metal housing and is sealed to the metal housing by dispensing adhesive.

8. A method for manufacturing a potting-type ultrathin metal sensor, characterized in that, The manufacturing method is used to manufacture the potting-type ultrathin metal sensor as described in any one of claims 1 to 7, and further includes... The light-emitting component, the light-receiving component, and the bonded integrated chip are placed on the circuit board, and the emitting aperture and the metal shield are installed at the corresponding positions on the circuit board. The emitting aperture has a matte surface facing the light-emitting component to form a photoelectric detection component. An optical lens is mounted to the circuit board via an adhesive sealing layer, and a racetrack-shaped sealing ring is formed between the optical lens and the circuit board to create a sealed fit between the optical lens and the circuit board, while exposing the light-transmitting area of ​​the optical lens. The photoelectric detection assembly with the optical lens installed is installed into the mounting cavity of the metal housing, and the tail plug assembly is installed on the metal housing to form a semi-finished product. The semi-finished product is placed in a potting mold, and potting material is injected into the metal shell according to the preset potting temperature and preset potting pressure, so that the potting material fills the empty space in the mounting cavity, and the light-transmitting area of ​​the optical lens is exposed outside the potting material; The potting material is cured to form an integrated sealed structure of the photoelectric detection component, the metal housing, and the tail plug component.

9. The method for manufacturing a potting-type ultrathin metal sensor according to claim 8, characterized in that, The process of mounting the optical lens to the circuit board via an adhesive sealing layer, forming a racetrack-shaped sealing ring between the optical lens and the circuit board to achieve a sealed fit and expose the light-transmitting area of ​​the optical lens includes: positioning the optical lens to the circuit board via a positioning connection structure, the positioning connection structure including multiple positioning protrusions on the optical lens and multiple positioning holes on the circuit board, the positioning protrusions being inserted into the positioning holes; applying UV adhesive to the bonding area between the optical lens and the circuit board to form the adhesive sealing layer; and / or heating the positioning protrusions to melt them, and then, after cooling, forming a fixed connection with the positioning holes.

10. The method for manufacturing a potting-type ultrathin metal sensor according to claim 9, characterized in that: The potting material is a semi-transparent thermoplastic polyurethane elastomer (TPU); the preset potting temperature ranges from 60°C to 120°C; and the preset potting pressure ranges from 0.1 MPa to 0.5 MPa.

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