Reflection-type photo interrupter packaging structure, secondary pressing mold and packaging method

Abstract

The invention relates to the field of photo interrupter packaging technology, in particular to a reflective photo interrupter packaging structure, a secondary pressing mold and a packaging method.The reflective photo interrupter packaging structure comprises an optical assembly, and the optical assembly comprises a light source and a light receiver and is used for emitting and receiving light rays; the circuit board is a split circuit board and is used for bearing the light source and the light receiver respectively; the first packaging layer covers the optical assembly and the circuit board and is made of an epoxy resin material; the second packaging layer covers the first packaging layer and is made of an epoxy resin material; a part of the circuit board penetrates out of the first packaging layer and the second packaging layer and is used for being connected with an external circuit. The packaging structure has the effect of improving the packaging stability and reliability of the reflective photo interrupter.

Description

Technical Field

[0001] The present application relates to the field of photointerrupter packaging technology, and in particular to a reflective photointerrupter packaging structure, a two-stage die, and a packaging method. Background Art

[0002] In today's era of rapid technological development, reflective photointerrupters, as an important optoelectronic component, have been widely used in automation, robotics, consumer electronics and many other fields. Reflective photointerrupters detect objects by emitting and receiving light and judging whether the light is reflected by an object. The ability to detect the existence and distance of an object, and its accuracy and reliability are crucial to improving product performance and intelligence.

[0003] Packaging plays a decisive role in the performance of reflective photointerrupters. Good packaging not only protects internal components from environmental factors, but also ensures the stability and reliability of the equipment during long-term operation. Therefore, optimizing packaging technology and material selection has become a key link in improving the performance of reflective photointerrupters.

[0004] However, in the relevant packaging technology, the method of using a plastic lead chip carrier bracket to form an outer retaining wall through an injection molding process, followed by silicone dispensing filling, although widely used, has obvious shortcomings. First, in order to prevent the bracket from oxidizing during the manufacturing process, a silver protective agent is usually required to be added. Even after water washing, there may still be residual protective agent, which leads to the problem of bracket contamination, which may affect the performance and reliability of the sensor. Secondly, there is a large difference in the expansion coefficient of the glue between the outer retaining wall and the silicone filling. This mismatch may cause thermal stress during heat treatment processes such as reflow soldering, resulting in delamination of the solid crystal silver glue and breakage of the gold wire, thereby affecting the working stability and service life of the sensor. Summary of the invention

[0005] In order to improve the stability and reliability of a reflective photointerrupter package, the present application provides a reflective photointerrupter package structure, a two-step molding die, and a packaging method.

[0006] A reflective photointerrupter packaging structure provided in the present application adopts the following technical solution: A reflective photointerrupter packaging structure, comprising: An optical component, comprising a light source and a light receiver, for emitting and receiving light; A circuit board, wherein the circuit board is a split circuit board, and carries the light source and the light receiver respectively; A first packaging layer, which covers the optical component and the circuit board and is made of epoxy resin material; A second packaging layer, the second packaging layer covers the first packaging layer and is made of epoxy resin material; Part of the circuit board passes through the first packaging layer and the second packaging layer for external circuit connection.

[0007] By adopting the above technical solution, the first packaging layer and the second packaging layer made of epoxy resin material provide protection and optical effect guarantee for the optical components and circuit boards, avoiding the use of plastic lead chip carrier brackets, thus avoiding the pollution problem caused by the residue of silver protective agent, making the entire packaging structure more stable and reliable. In addition, the double-layer design of the first packaging layer and the second packaging layer not only provides additional physical protection, but also helps to isolate the influence of electromagnetic interference and temperature fluctuations, maintain the stable working state of the internal components of the package under different environments, and improve the reliability of the equipment. The circuit board passes through the packaging layer to allow the circuit board to be directly connected to the external circuit, which is convenient for signal transmission and power supply access.

[0008] Optionally, the difference in thermal expansion coefficients of the epoxy resin materials of the first encapsulation layer and the second encapsulation layer is less than or equal to 10 ppm / °C.

[0009] By adopting the above technical solution, the thermal expansion coefficients of the two packaging layers are similar. When the packaging material is subjected to temperature changes, the materials of the two adjacent layers expand or contract at a similar rate, which can minimize the internal thermal stress caused by temperature changes, reduce the shear stress between the packaging layers, and prevent packaging deformation or internal component displacement due to temperature changes, thereby improving the thermal stability of the packaging structure. In addition, similar thermal expansion coefficients help maintain a strong bond between the packaging layers and prevent interlayer separation, especially in the case of thermal shock or long-term thermal cycling. In addition, the use of materials with similar thermal expansion coefficients can simplify the packaging process, reduce the thermal mismatch problem that needs to be considered during the manufacturing process, and improve production efficiency and product quality.

[0010] Optionally, a nanostructure layer is formed on the surface of the first encapsulation layer, and the refractive index of the nanostructure layer is between the first encapsulation layer and the second encapsulation layer, forming a gradient refractive index.

[0011] By adopting the above technical solution, a nanostructure layer with an intermediate refractive index is introduced between the first encapsulation layer and the second encapsulation layer. When light is transmitted from one medium to another medium with a different refractive index, part of the light will be reflected back. If the refractive index of the medium can change gradually through the intermediate layer, the reflection of light can be significantly reduced, thereby improving the transmission efficiency of light. The nanostructure layer with a gradient refractive index can more effectively guide light from the light source to the outside world, optimize the optical path and reduce the light energy loss caused by interface reflection, thereby improving the sensitivity and response speed of the photointerrupter.

[0012] Optionally, the second encapsulation layer includes a reflective coating having a selective light wavelength reflection characteristic, for reflecting a specific range of external interfering light wavelengths.

[0013] By adopting the above technical solution, by reflecting a specific range of external interfering light wavelengths, it helps to reduce the interference caused by external light sources, so that the optical receiver can focus more on receiving the reflected light from the light source, thereby improving the accuracy and reliability of the photointerrupter detection signal, and improving the response sensitivity and measurement accuracy of the photointerrupter. This is especially important in environments with complex or changing light. At the same time, selective light wavelength reflection can protect internal components from potential damage from specific wavelengths of light, especially under strong lighting conditions, helping to maintain the stability of the system and extend its service life.

[0014] Optionally, a portion of the circuit board that passes through the first packaging layer and the second packaging layer is provided with a tin plating layer.

[0015] By adopting the above technical solution, the tin plating can significantly improve the welding performance of the corresponding part on the circuit board, making the connection more stable and reliable, ensuring the quality and efficiency of signal transmission. And the tin plating can effectively prevent the oxidation of copper or other metal materials in the protruding part of the circuit board, and extend the service life of the circuit board. In addition, the tin plating can also increase the mechanical strength and wear resistance of the protruding part of the circuit board, reduce wear under plugging or mechanical stress, and improve the physical stability of the connection point.

[0016] The two-stage die for the reflective photointerrupter packaging structure provided in the present application adopts the following technical solution: A two-pass die mold, comprising: A first mold, the first mold is configured as a cubic structure with one side open, and is used for compression molding of the first encapsulation layer; a second mold, wherein the first mold is configured as a cubic structure with one side open and has a larger volume than the first mold, and is used for compression molding of the second encapsulation layer; Wherein, the first mold and the second mold are both divided into two parts, an upper mold and a lower mold, and the lower mold is provided with a clearance groove for accommodating the protruding part of the circuit board.

[0017] By adopting the above technical solution, the mold is divided into two parts, the upper mold and the lower mold, which is conducive to accurately placing and positioning the circuit board before pressing, while ensuring precise alignment when the mold is closed, improving the accuracy and repeatability of the packaging process. The design of the clearance groove allows the protruding part of the circuit board to be properly accommodated when the mold is closed, avoiding pressure on the protruding part of the circuit board during the pressing process, reducing the potential risk of damage. The split mold design simplifies the assembly and disassembly process, making the installation and removal of the circuit board more convenient and improving production efficiency. At the same time, this design also provides greater flexibility to accommodate circuit boards of different sizes and shapes.

[0018] Optionally, inner walls of the first mold and the second mold are both provided with strip-shaped grooves, and the strip-shaped grooves are evenly distributed.

[0019] By adopting the above technical solution, the strip grooves can be used as a guiding structure to help the packaging material maintain uniform distribution when flowing in the mold, reduce the aggregation or voids of the material in the mold, and ensure the uniformity and consistency of the packaging layer material. In addition, the strip grooves can promote heat dispersion during the packaging process, help control the temperature of the mold and the material, reduce internal stress or deformation caused by uneven temperature, and improve the thermal stability of the packaging structure. In addition, the strip grooves can promote the packaging material to fill the mold faster and more effectively, reduce the formation of bubbles, and improve the efficiency of the mold filling process and the quality of the packaging layer.

[0020] Optionally, the upper die is provided with a protrusion, and the lower die is provided with an alignment groove, and the protrusion is engaged with the alignment groove.

[0021] By adopting the above technical solution, the connection between the protrusion and the alignment groove ensures that the upper and lower molds are accurately aligned during the molding process. This mechanical docking method reduces human errors, simplifies the operation process of mold alignment, improves the sealing of the mold side walls, and improves the packaging quality. When producing multiple packages, the design of the protrusion and the alignment groove ensures consistent alignment of the mold during each packaging process, enhancing the consistency of the product. After the packaging process is completed, the design of the protrusion and the alignment groove also makes it easier to separate the mold, making it convenient to remove the packaged product and carry out subsequent processing or inspection.

[0022] Optionally, the two-stage die mold further includes a scraper plate to remove excess filler in the first mold and the second mold.

[0023] By adopting the above technical solution, using a scraper to remove excess filler in the mold can ensure the flatness and smoothness of the surface of the packaging layer, avoid protrusions or irregular surfaces formed after the excess material solidifies, and thus improve the surface quality of the packaging structure. By ensuring the effective removal of excess material in each packaging process, the scraper helps maintain the consistency of the packaging process and ensures that the quality of each packaging unit meets the predetermined standards. In addition, the smooth surface of the packaging layer reduces the need for subsequent processing or correction, such as grinding or cleaning, thereby improving production efficiency and reducing production costs.

[0024] The present application provides a packaging method for a reflective photointerrupter packaging structure using the following technical solutions: A packaging method, comprising: S1. Install the light source and the light receiver on the two parts of the split circuit board respectively, and ensure that the light source and the light receiver are arranged relative to each other; S2. Solder the split circuit board with gold wire to ensure stable electrical connection and signal transmission; S3, using a specific mold to perform a first molding on the light source, the light receiver and the circuit board to form a first packaging layer; S4. Use a scraper to remove excess filler to ensure a clean surface; S5, performing a coating process on the first encapsulation layer to form a nanostructure layer on the surface; S6, placing the first encapsulation layer formed by the first molding into a specific mold for a second molding to form a second encapsulation layer; S7. Use a scraper to remove excess filler to ensure a clean surface; S8, performing a coating process on the second packaging layer to form a reflective coating having a selective light wavelength reflection characteristic on the surface; S9, performing tin plating treatment on the portion of the circuit board protruding from the first packaging layer and the second packaging layer; S10. Perform appearance and function inspection on the entire reflective photointerrupter packaging structure to ensure that the packaging quality meets the predetermined standards.

[0025] By adopting the above technical solution, the light source and the light receiver are installed separately in step S1 to reduce mutual interference. The use of gold wire welding in step S2 ensures stable electrical connection. The molding process in steps S3 and S6 and the operation of removing excess filler in steps S4 and S7 ensure the uniformity and surface cleanliness of the packaging layer, which is conducive to improving the overall quality of the packaging structure. The coating treatment in steps S5 and S8 forms a specific nanostructure and reflective coating on the surface of the packaging layer, optimizes the transmission and reflection of light, and improves optical efficiency. The tin plating treatment in step S9 increases the corrosion resistance of the protruding part of the circuit board and improves the stability and life of the equipment in complex environments. The appearance and functional inspection in step S10 ensure that each product meets the predetermined quality standards, improving product reliability and user satisfaction.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. The first and second encapsulation layers of epoxy resin provide protection for optical components and circuit boards, avoiding the pollution problems of using plastic lead chip carrier brackets and related silver protectants. At the same time, this double-layer design enhances physical protection, reduces electromagnetic and temperature fluctuation interference, and maintains component stability; 2. Use two packaging layers with similar thermal expansion coefficients to reduce internal thermal stress and shear stress caused by temperature changes, prevent packaging deformation and interlayer separation, and improve the thermal stability of the packaging structure; 3. By forming a specific nanostructure and reflective coating on the surface of the encapsulation layer, the transmission and reflection of light are optimized, and the sensitivity and response speed of the photointerrupter are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of a reflective photointerrupter packaging structure in Example 1 of the present application.

[0028] Figure 2 It is a cross-sectional view of a reflective photointerrupter packaging structure in Example 1 of the present application.

[0029] Figure 3 This is a schematic diagram of a two-stage die in Example 2 of the present application.

[0030] Figure 4 This is an exploded view of the upper mold and the lower mold in Example 2 of the present application.

[0031] Figure 5 It is a schematic diagram of a packaging method for a reflective photointerrupter packaging structure in Example 3 of the present application.

[0032] Description of reference numerals: 11. Optical component; 111. Light source; 112. Light receiver; 12. Circuit board; 121. Tin plating layer; 13. First packaging layer; 131. Nanostructure layer; 14. Second packaging layer; 141. Reflective coating; 21. First mold; 22. Second mold; 23. Upper mold; 231. Protrusion; 24. Lower mold; 241. Clearance groove; 242. Alignment groove; 25. Strip groove; 26. Scraper plate. DETAILED DESCRIPTION

[0033] The present application is further described in detail below in conjunction with all the accompanying drawings.

[0034] The embodiment of the present application discloses a reflective photointerrupter packaging structure.

[0035] Example 1 Reference Figure 1 A reflective photointerrupter packaging structure includes a first packaging layer 13, a second packaging layer 14 and a circuit board 12. The first packaging layer 13 and the second packaging layer 14 are both made of epoxy resin material with excellent mechanical and protective properties, ensuring physical and chemical protection of the internal components of the package.

[0036] refer to Figure 2 In this packaging structure, the first packaging layer 13 tightly wraps the internal optical component 11 and circuit board 12, while the second packaging layer 14 covers the first packaging layer 13 to form an additional protective layer. The double-layer packaging design not only enhances the structural strength of the package, but also provides additional shielding against electromagnetic interference and temperature fluctuations, which helps to maintain the stable working state of the components inside the package.

[0037] The circuit board 12 not only supports and connects the optical component 11 in the package, but also partially penetrates the package layer to expose the outside of the package. This part of the circuit board 12 is used to connect the package structure with the external circuit to ensure that the photointerrupter can receive power and transmit signals.

[0038] In the reflective photointerrupter packaging structure, the first packaging layer 13 encapsulates the optical component 11 and part of the circuit board 12, wherein the circuit board 12 adopts a split design and is divided into two oppositely arranged parts to enhance functionality and reliability. The two parts of the circuit board 12 are connected by gold wires to ensure the stability and efficiency of signal transmission. The optical component 11 is composed of a light source 111 and a light receiver 112, which are respectively installed on the two parts of the split circuit board 12, and are responsible for emitting and receiving light, respectively, thereby realizing the core function of the photointerrupter.

[0039] The first packaging layer 13 made of epoxy resin material not only provides strong protection for the optical component 11 and the circuit board 12, but also optimizes the optical effect. In addition, the use of epoxy resin avoids the need for a traditional plastic lead chip carrier bracket, thereby eliminating the residual contamination problem that may be caused by the use of silver protective agent, thereby improving the reliability of the packaging structure.

[0040] Considering the influence of thermal expansion of materials, in the packaging structure of the reflective photointerrupter, epoxy resin materials with very close thermal expansion coefficients are selected to manufacture the first packaging layer 13 and the second packaging layer 14, and the difference in thermal expansion coefficients is strictly controlled to be less than or equal to 10ppm / °C. When the packaging structure encounters temperature fluctuations, the two adjacent packaging layers will experience almost the same rate of expansion or contraction, effectively minimizing the internal thermal stress caused by temperature changes. Not only does it reduce the shear stress that may occur between the packaging layers, it also greatly reduces the risk of packaging deformation or internal component displacement caused by temperature fluctuations, greatly improving the thermal stability of the packaging structure.

[0041] Furthermore, similar thermal expansion coefficients between packaging layers promote strong bonding between layers and effectively prevent interlayer separation caused by thermal stress mismatch, which is particularly important when the packaging structure is subjected to thermal shock or undergoes long-term thermal cycling. In addition, the use of materials with similar thermal expansion coefficients simplifies the packaging process and reduces concerns about thermal mismatch during the manufacturing process, thereby improving production efficiency and the quality of the final product.

[0042] At the same time, a nanostructure layer 131 is disposed on the surface of the first encapsulation layer 13, which is located between the first encapsulation layer 13 and the second encapsulation layer 14, and whose refractive index is between the two, in order to create a gradient refractive index transition between the two encapsulation layers. This gradient refractive index means that the refractive index of the nanostructure layer 131 changes between the refractive index of the first encapsulation layer 13 and the second encapsulation layer 14, so that the refractive index change when light passes through this layer is more gradual, thereby significantly reducing the reflection of light on these interfaces.

[0043] The introduction of the nanostructure layer 131 not only optimizes the transmission path of light, allowing light to be more efficiently transmitted from the light source 111 to the external environment, but also greatly reduces the light energy loss caused by reflection at the material interface. By reducing these losses, the optical efficiency of the photointerrupter is significantly improved, thereby enhancing the sensitivity and response speed of the device, ensuring that the photointerrupter can detect and respond to changes in optical signals more accurately and quickly.

[0044] A reflective coating 141 with selective light wavelength reflection characteristics is coated on the surface of the second packaging layer 14. It is designed to reflect interference light within a specific wavelength range, which usually comes from the external environment and may have an adverse effect on the performance of the photointerrupter. By effectively reflecting these interference lights, the reflective coating 141 significantly reduces the interference of the external light source 111 on the light receiver 112, allowing the light receiver 112 to focus more on capturing the reflected light from the light source 111, thereby significantly improving the accuracy and reliability of the photointerrupter detection signal, ensuring that the photointerrupter maintains a high degree of performance stability in an environment with changing light conditions.

[0045] In addition, the reflective coating 141 also protects the internal components, especially under strong lighting conditions, and can prevent light of a specific wavelength from damaging the internal components. This not only helps maintain the long-term stability of the system, but also extends the service life of the photointerrupter and reduces maintenance costs and frequency.

[0046] The portion of the circuit board 12 that passes through the packaging structure is coated with a layer of tin plating 121, which improves the performance of the portion of the circuit board 12 that passes through in terms of electrical connection and physical durability. The tin plating 121 can effectively isolate the direct contact between the metal and the air and prevent the oxidation of copper or other metal materials. It not only ensures the stability and reliability of the solder joints, but also significantly improves the quality and efficiency of the signal transmission process, thereby ensuring that the photointerrupter can accurately and quickly respond to external signals. In addition to the improvement of electrical performance, the tin plating 121 also enhances the mechanical strength and wear resistance of the portion of the circuit board 12 that passes through, especially under frequent plugging and unplugging and mechanical stress.

[0047] The implementation principle of Example 1 is: In the present embodiment, the reflective photointerrupter packaging structure uses epoxy resin materials with similar thermal expansion coefficients to construct the first packaging layer 13 and the second packaging layer 14, providing protection and optical support for the internal optical components 11 and circuit board 12, avoiding the pollution problems that may be caused by the traditional plastic lead chip carrier bracket and the silver protective agent required, ensuring the advantages of the packaging structure in chemical stability, and reducing the risks of packaging deformation and interlayer separation caused by temperature fluctuations, significantly improving the thermal stability of the packaging structure, and ensuring the integrity of the packaging structure and the stability of its functions under different temperature conditions.

[0048] In terms of surface treatment of the packaging structure, the light transmission path is further optimized by introducing a nanostructure layer 131 with a gradient refractive index and a reflective coating 141 with selective light wavelength reflection characteristics. The nanostructure layer 131 is formed on the surface of the first packaging layer 13, which effectively reduces light reflection at the interface and improves the light transmission efficiency; while the reflective coating 141 on the surface of the second packaging layer 14 is specially designed to reflect a specific range of interfering light wavelengths, reduce external interference, and enhance the receiving accuracy of the light receiver 112. The combination of surface treatment technology not only improves the sensitivity and response speed of the photointerrupter, but also ensures the reliability and performance of the device in variable lighting environments.

[0049] The embodiment of the present application discloses a two-stage compression mold.

[0050] Example 2 Reference Figure 3 A two-pass die mold includes a first mold 21, a second mold 22 and a scraper 26, wherein the first mold 21 and the second mold 22 are designed to form a first encapsulation layer 13 and a second encapsulation layer 14 of a reflective photointerrupter, respectively. The two molds correspond to different levels of the encapsulation structure, ensuring that the molding of each layer can be carried out accurately, thereby adapting to complex encapsulation requirements. The scraper 26 is mainly used to remove excess filler in the mold, ensure the flatness and smoothness of the surface of the encapsulation layer, and make the surface quality of the encapsulation structure meet the standard.

[0051] The first mold 21 and the second mold 22 are both designed as a cubic structure with one side open, and are divided into an upper mold 23 and a lower mold 24 to meet complex packaging requirements. The split design is not only convenient for the operation and maintenance of the mold, but also has important functional significance. In particular, a clearance groove 241 is designed on the side wall of the lower mold 24 to accommodate the protruding parts of the circuit board 12, ensuring that no unnecessary pressure is applied to these protruding parts during the molding process, thereby greatly reducing the risk of damaging the circuit board 12 and ensuring the integrity and functional stability of the circuit board 12.

[0052] In addition, reference Figure 4 In order to simplify the alignment operation of the mold and improve its accuracy, the bordering surfaces of the upper mold 23 and the lower mold 24 are designed with corresponding protrusions 231 and alignment grooves 242. When the protrusions 231 are engaged with the alignment grooves 242, the upper mold 23 and the lower mold 24 are accurately aligned and spliced ​​together, which not only simplifies the operation process of mold alignment, but also improves the sealing of the mold side wall, further enhancing the stability and reliability during the packaging process. Ensure the accuracy and consistency during the packaging process.

[0053] Furthermore, strip grooves 25 are provided on the inner walls of the first mold 21 and the second mold 22. The strip grooves 25 are perpendicular to the bottom surface opposite to the opening and are evenly distributed to optimize the packaging process. The strip grooves 25 not only serve as a guide structure to guide the packaging material to flow evenly in the mold, avoiding excessive aggregation of materials or formation of voids in specific areas, but also ensure the uniformity and consistency of the packaging layer material. Secondly, the strip grooves 25 also promote heat dispersion during the packaging process, help maintain the temperature balance of the mold and the material, thereby reducing the internal stress or deformation caused by uneven temperature, and significantly improving the thermal stability of the packaging structure.

[0054] In addition, the strip grooves 25 also help the packaging material to fill the entire mold more quickly and effectively, reducing the formation of bubbles in the process, thereby improving the efficiency of the mold filling process and the overall quality of the packaging layer. In this way, the provision of the strip grooves 25 not only ensures the quality of the packaging layer, but also improves the production efficiency of the entire packaging process.

[0055] The implementation principle of Example 2 is: Designing the mold into a two-part structure of an upper mold 23 and a lower mold 24 significantly improves the ability to accurately place and position the circuit board 12 before molding, which is crucial to ensuring the accuracy and repeatability of the packaging process. The split design ensures precise alignment when the mold is closed, thereby improving the overall efficiency of the packaging process. In particular, the design of the clearance groove 241 takes into account the space requirements of the protruding part of the circuit board 12, ensuring that when the mold is closed, the protruding part of the circuit board 12 is properly accommodated without being subjected to pressure, significantly reducing the risk of damage to the protruding part of the circuit board 12 during the molding process. At the same time, the design of the split mold simplifies the entire assembly and disassembly process, making the installation and removal of the circuit board 12 more convenient, thereby improving the efficiency of the production line.

[0056] The embodiment of the present application discloses a packaging method for a reflective photointerrupter packaging structure.

[0057] Example 3 refer to Figure 5 , a packaging method for a reflective photointerrupter packaging structure comprises: S1, installing the light source 111 and the light receiver 112 on two parts of the split circuit board 12 respectively, ensuring that the light source 111 and the light receiver 112 are arranged opposite to each other; S2, soldering the split circuit board 12 with gold wire to ensure stable electrical connection and signal transmission; S3, using a specific mold to perform a first molding on the light source 111, the light receiver 112 and the circuit board 12 to form a first packaging layer 13; S4, using a scraper 26 to remove excess filler to ensure a clean surface; S5, performing a coating process on the first encapsulation layer 13 to form a nanostructure layer 131 on the surface; S6, placing the first encapsulation layer 13 formed by the first molding into a specific mold for a second molding to form a second encapsulation layer 14; S7, using the scraper 26 to remove excess filler to ensure a clean surface; S8, performing a coating process on the second encapsulation layer 14 to form a reflective coating 141 having a selective light wavelength reflection characteristic on the surface; S9, performing tin plating 121 on the portion of the circuit board 12 protruding from the first packaging layer 13 and the second packaging layer 14; S10. Perform appearance and function inspection on the entire reflective photointerrupter packaging structure to ensure that the packaging quality meets the predetermined standards.

[0058] The implementation principle of Example 3 is: The initial step of installing the light source 111 and the light receiver 112 separately significantly reduces the mutual interference between the light source 111 and the light receiver 112, laying the foundation for high-precision optical signal transmission. Gold wire welding ensures a stable electrical connection between the circuit boards 12. The uniformity and consistency of the packaging layer are ensured by adopting a specific mold and controlling the sequence. Then, the excess filler is removed to improve the overall quality of the packaging structure. The coating treatment forms a specific nanostructure and reflective coating 141 on the surface of the packaging layer, which effectively improves the optical efficiency and sensitivity of the photointerrupter by optimizing the optical path. The tin plating 121 treatment of the protruding part of the circuit board 12 increases the corrosion resistance and improves the stability and life of the equipment in complex environments. Appearance and functional inspections ensure that the predetermined quality standards are met.

[0059] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A reflective photointerrupter packaging structure, characterized in that: include: An optical component (11), the optical component (11) comprising a light source (111) and a light receiver (112), and being used for emitting and receiving light; A circuit board (12), wherein the circuit board (12) is a split circuit board (12), and carries the light source (111) and the light receiver (112) respectively; a first packaging layer (13), the first packaging layer (13) covering the optical component (11) and the circuit board (12), and made of epoxy resin material; a second encapsulation layer (14), the second encapsulation layer (14) covering the first encapsulation layer (13) and made of epoxy resin material; Part of the circuit board (12) passes through the first packaging layer (13) and the second packaging layer (14) for external circuit connection.

2. A reflective photointerrupter packaging structure according to claim 1, characterized in that: The difference in thermal expansion coefficients of the epoxy resin materials of the first encapsulation layer (13) and the second encapsulation layer (14) is less than or equal to 10 ppm / °C.

3. A reflective photointerrupter packaging structure according to claim 1, characterized in that: A nanostructure layer (131) is formed on the surface of the first encapsulation layer (13), and the refractive index of the nanostructure layer (131) is between the first encapsulation layer (13) and the second encapsulation layer (14), forming a gradient refractive index.

4. A reflective photointerrupter packaging structure according to claim 3, characterized in that: The second encapsulation layer (14) comprises a reflective coating (141) having a selective light wavelength reflection characteristic, and is used to reflect external interference light wavelengths within a specific range.

5. The reflective photointerrupter packaging structure according to claim 1, characterized in that: The portion of the circuit board (12) that passes through the first packaging layer (13) and the second packaging layer (14) is provided with a tin plating layer (121).

6. A two-stage die stamping die for the reflective photointerrupter packaging structure according to any one of claims 1 to 5, characterized in that: include: A first mold (21), the first mold (21) being configured as a cubic structure with one side open, and being used for compression molding of the first encapsulation layer (13); A second mold (22), wherein the first mold (21) is configured as a cubic structure with an opening on one side and has a larger volume than the first mold (21), and is used for compression molding of the second encapsulation layer (14); The first mold (21) and the second mold (22) are both divided into two parts, an upper mold (23) and a lower mold (24), and the lower mold (24) is provided with a clearance groove (241) for accommodating a protruding part of the circuit board (12).

7. A two-stage die according to claim 6, characterized in that: The inner walls of the first mould (21) and the second mould (22) are both provided with strip-shaped grooves (25), and the strip-shaped grooves (25) are evenly distributed.

8. A two-stage die according to claim 6, characterized in that: The upper die (23) is provided with a protrusion (231), and the lower die (24) is provided with an alignment groove (242), and the protrusion (231) is engaged with the alignment groove (242).

9. A two-stage die according to claim 6, characterized in that: The two-stage die-casting mold further comprises a scraper plate (26) for removing excess fillers in the first mold (21) and the second mold (22).

10. A packaging method for the reflective photointerrupter packaging structure according to any one of claims 1 to 5, comprising: S1, installing the light source (111) and the light receiver (112) on two parts of the split circuit board (12) respectively, ensuring that the light source (111) and the light receiver (112) are arranged relative to each other at a distance; S2, soldering the split circuit board (12) with gold wire to ensure stable electrical connection and signal transmission; S3, using a specific mold to perform a first molding on the light source (111), the light receiver (112), and the circuit board (12), to form a first packaging layer (13); S4, using a scraper (26) to remove excess filler to ensure a clean surface; S5, performing a coating process on the first encapsulation layer (13) to form a nanostructure layer (131) on the surface; S6, placing the first encapsulation layer (13) formed by the first molding into a specific mold for a second molding to form a second encapsulation layer (14); S7, using a scraper (26) to remove excess filler to ensure a clean surface; S8, performing a coating process on the second packaging layer (14) to form a reflective coating (141) having a selective light wavelength reflection characteristic on the surface; S9, performing a tin plating (121) process on the portion of the circuit board (12) protruding from the first packaging layer (13) and the second packaging layer (14); S10. Perform appearance and function inspection on the entire reflective photointerrupter packaging structure to ensure that the packaging quality meets the predetermined standards.

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