Optical sensor packaging structure

Abstract

The invention provides an optical sensor packaging structure. The optical sensor packaging structure comprises a substrate; the sensor chip is arranged on the surface of the substrate, and the surface, deviating from the substrate, of the sensor chip is provided with a photosensitive area; the plastic package body covers the surface of the substrate and wraps the sensor chip, the plastic package body is provided with an optical conduction cavity, the optical conduction cavity exposes the photosensitive area, and the top of the plastic package body is provided with a step surrounding the optical conduction cavity; the light-transmitting cover plate covers the optical conduction cavity, the light-transmitting cover plate comprises a fixed plate and a first boss arranged on the bottom surface of the fixed plate, the side edge of the fixed plate protrudes out of the side surface of the first boss, extends to the step and is fixed on the step in a sealing manner, and the first boss is inserted into the optical conduction cavity and is not in contact with the photosensitive area. According to the optical sensor packaging structure provided by the invention, through the arrangement of the first boss, the volume of gas in the optical conduction cavity is reduced, the internal and external air pressure difference during working of the optical sensor packaging structure is reduced, and the situation that the light-transmitting cover plate falls off or is damaged due to the too large internal and external air pressure difference of the optical sensor packaging structure is avoided; and the reliability of the optical sensor packaging structure is improved.

Description

Technical Field

[0001] The present invention relates to the field of packaging, and in particular to an optical sensor packaging structure. Background Art

[0002] An optical sensor is a semiconductor device that can sense external light and convert it into electrical signals. Packaging an optical sensor can form an optical sensor packaging structure. The optical sensor packaging structure is commonly used in various electronic terminals, such as cameras, smart phones, digital cameras, automotive imaging systems, toys and other electronic devices.

[0003] At present, in the packaging process of optical sensor packaging structure, a transparent cover plate is usually placed above the sensor chip. Figure 1 , which is a schematic diagram of an existing optical sensor packaging structure, a sensor chip 100 is arranged on a substrate 110, a plastic package 120 covers the substrate 110 and forms an optical conduction cavity 121, the optical conduction cavity 121 exposes the photosensitive area 101 of the sensor chip 100, and a transparent cover plate 130 is mounted on the top of the optical conduction cavity 121 to protect the photosensitive area 101 of the sensor chip 100 to ensure the normal operation of the sensor chip 100. In this optical sensor packaging structure, the transparent cover plate 130 is a flat structure. After the transparent cover plate 130 is mounted on the top of the optical conduction cavity 121, the distance between the transparent cover plate 130 and the sensor chip 100 is large. The optical conduction cavity 121 contains a large amount of gas. When the product is working, the internal and external pressure difference is too large, which will cause the transparent cover plate 130 to fall off or be damaged, affecting the reliability of the optical sensor packaging structure.

[0004] Therefore, providing an optical sensor packaging structure with high reliability has become one of the current research focuses. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an optical sensor packaging structure, which can improve the reliability of the optical sensor packaging structure.

[0006] In order to solve the above problems, the present invention provides an optical sensor packaging structure, which includes: a substrate; a sensor chip, which is arranged on the surface of the substrate, and the surface of the sensor chip facing away from the substrate has a photosensitive area; a plastic package, which covers the surface of the substrate and encapsulates the sensor chip, the plastic package has an optical conduction cavity, the optical conduction cavity exposes the photosensitive area, and the top of the plastic package has a step surrounding the optical conduction cavity; a transparent cover plate, which covers the optical conduction cavity, the transparent cover plate includes a fixing plate and a first boss arranged on the bottom surface of the fixing plate, the side edge of the fixing plate protrudes from the side of the first boss and extends to the step, and is sealed and fixed on the step, the first boss is inserted into the optical conduction cavity, and does not contact the photosensitive area.

[0007] In a specific embodiment, a second boss is further provided on the bottom surface of the fixing plate, the second boss is arranged on the periphery of the first boss, the step surface of the step is provided with a groove, and the second boss is inserted into the groove.

[0008] In a specific embodiment, the height of the second boss is smaller than the height of the first boss.

[0009] In a specific embodiment, a side edge of the fixing plate protrudes from a side surface of the second boss.

[0010] In a specific embodiment, a side surface of the second boss facing away from the first boss is flush with a side edge of the fixing plate.

[0011] In a specific embodiment, the groove is located in an inner area of ​​the step surface.

[0012] In a specific embodiment, a side wall of the groove facing away from the first boss is flush with a step wall of the step.

[0013] In a specific embodiment, the width of the groove is the same as the width of the second boss, or the width of the groove is greater than the width of the second boss.

[0014] In a specific embodiment, when the width of the groove is greater than the width of the second boss, the side surface of the second boss contacts the side wall of the groove close to the first boss, and there is a gap between the side surface of the second boss and the side wall of the groove away from the first boss.

[0015] In a specific embodiment, the fixing plate is fixed to the step wall and the step surface by an adhesive layer.

[0016] In a specific embodiment, the adhesive layer is located outside the second boss.

[0017] In a specific embodiment, the vertical distance from the top of the optical conduction cavity to the photosensitive area is greater than the height of the light-transmitting cover plate.

[0018] In a specific embodiment, a vertical distance from the step surface to the photosensitive area is greater than a height of the first boss.

[0019] In a specific embodiment, the profile of the side surface of the first boss is the same as the profile of the side wall of the optical conduction cavity.

[0020] In a specific implementation, the top surface of the fixing plate is flush with the top surface of the plastic packaging body, or the top surface of the fixing plate protrudes from the top surface of the plastic packaging body.

[0021] In the optical sensor packaging structure provided by the present invention, the first boss of the light-transmitting cover plate is inserted into the optical conduction cavity, occupying part of the space of the optical conduction cavity, reducing the volume of the gas in the optical conduction cavity, and reducing the internal and external air pressure difference when the optical sensor packaging structure is working, thereby avoiding the light-transmitting cover plate from falling off or being damaged due to excessive internal and external air pressure difference of the optical sensor packaging structure, and improving the reliability of the optical sensor packaging structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following is a brief introduction to the drawings required for the description of the specific embodiments. Obviously, the drawings described below are only some specific embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 is a schematic diagram of an existing optical sensor packaging structure;

[0024] Figure 2 is a schematic diagram of an optical sensor packaging structure provided by a first specific embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of a light-transmitting cover plate of an optical sensor packaging structure provided in a first specific embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of an optical conduction cavity of a plastic package body of an optical sensor packaging structure provided in a first specific embodiment of the present invention;

[0027] Figure 5 is a schematic diagram of an optical sensor packaging structure provided by a second specific embodiment of the present invention;

[0028] Figure 6is a schematic diagram of an optical sensor packaging structure provided by a third specific embodiment of the present invention;

[0029] Figure 7 is a schematic diagram of an optical sensor packaging structure provided by a fourth specific embodiment of the present invention;

[0030] Figure 8 It is a schematic diagram of an optical sensor packaging structure provided in a fifth specific embodiment of the present invention. DETAILED DESCRIPTION

[0031] The specific implementation of the optical sensor packaging structure provided by the present invention is described in detail below with reference to the accompanying drawings.

[0032] Figure 2 is a schematic diagram of an optical sensor packaging structure provided by a first specific embodiment of the present invention, Figure 3 is a schematic diagram of a light-transmitting cover plate of an optical sensor packaging structure provided in a first specific embodiment of the present invention, Figure 4 is a schematic diagram of the optical conduction cavity of the plastic package of the optical sensor packaging structure provided by the first specific embodiment of the present invention, please refer to Figure 2 , Figure 3 and Figure 4 The optical sensor packaging structure includes: a substrate 200; a sensor chip 300, which is arranged on the surface of the substrate 200, and the surface of the sensor chip 300 facing away from the substrate 200 has a photosensitive area 310; a plastic package 400, which covers the surface of the substrate 200 and encapsulates the sensor chip 300, and the plastic package 400 has an optical conduction cavity 410, the optical conduction cavity 410 exposes the photosensitive area 310, and the top of the plastic package 400 has a step 420 surrounding the optical conduction cavity 410; a transparent cover plate 500, which covers the optical conduction cavity 410, and the transparent cover plate 500 includes a fixing plate 510 and a first boss 520 arranged on the bottom surface of the fixing plate 510, the side edge of the fixing plate 510 protrudes from the side of the first boss 520 and extends to the step 420, and is sealed and fixed on the step 420, and the first boss 520 is inserted into the optical conduction cavity 410 and does not contact the photosensitive area 310.

[0033] In the optical sensor packaging structure provided in the specific embodiment of the present invention, the first boss 520 of the transparent cover plate 500 is inserted into the optical conduction cavity 410, occupying part of the space of the optical conduction cavity 410, reducing the volume of the gas in the optical conduction cavity 410, and reducing the internal and external air pressure difference when the optical sensor packaging structure is working, avoiding the transparent cover plate 500 from falling off or being damaged due to excessive internal and external air pressure difference of the optical sensor packaging structure, thereby improving the reliability of the optical sensor packaging structure.

[0034] The substrate 200 can be an existing ceramic substrate, or a lead frame, or a laminated substrate, or an MIS (Molded Interconnect System) plastic package interconnect substrate, or a redistribution stacking layer, etc., which has a relatively flat upper surface and lower surface, and an electrically conductive circuit layer between the upper surface and the lower surface.

[0035] The sensor chip 300 is arranged on the upper surface of the substrate 200, and is used to sense external light and convert it into an electrical signal. Specifically, the surface of the sensor chip 300 facing away from the substrate 200 has a photosensitive area 310, and the photosensitive area 310 receives external light, converts it into an electrical signal, and transmits it to the substrate 200 through the circuit of the sensor chip 300. In this specific embodiment, the back of the sensor chip 300 is fixed to the surface of the substrate 200 through an adhesive layer, and the front of the sensor chip 300 is provided with the photosensitive area 310 and a pad, and the pad is electrically connected to the substrate 200 through a lead.

[0036] The plastic package 400 covers the surface of the substrate 200 and covers the sensor chip 300. The optical conduction cavity 410 of the plastic package 400 is located above the sensor chip 300 and exposes the photosensitive area 310, that is, the optical conduction cavity 410 runs through the plastic package 400. In this specific embodiment, the plastic package 400 also covers the outer edge of the sensor chip 300 and covers the pads and the leads. The plastic package 400 can be formed by injection molding. It covers the surface of the substrate 200 and covers the sidewalls and part of the front of the sensor chip 300 through an injection molding process, and forms an optical conduction cavity 410 above the photosensitive area 310. The top of the plastic package 400 has a step 420 surrounding the optical conduction cavity 410. In some specific embodiments, the step 420 surrounds the optical conduction cavity 410.

[0037] The light-transmitting cover plate 500 is a light-transmitting isolation plate. External light passes through the light-transmitting cover plate 500 and enters the photosensitive area 310 of the sensor chip 300. External light includes but is not limited to laser, visible light, infrared light, etc. In some specific embodiments, the light-transmitting cover plate 500 is a light-transmitting glass plate. Figure 2 In the Z direction), the light-transmitting cover plate 500 covers the optical conduction cavity 410, and the light-transmitting cover plate 500 corresponds to the photosensitive area 310 of the sensor chip 300, so that external light passes through the light-transmitting cover plate 500 and then enters the photosensitive area 310 of the sensor chip 300 through the optical conduction cavity 410.

[0038] The side edge of the fixing plate 510 of the light-transmitting cover plate 500 protrudes from the side of the first boss 520 and extends to the step 420, and is sealed and fixed on the step 420. The first boss 520 is inserted into the optical transmission cavity 410, that is, the light-transmitting cover plate 500 is an inverted convex shape with a thick middle and thin ends. The light-transmitting cover plate 500 is an integrally formed structure, and there is no substantial boundary at the junction of the fixing plate 510 and the first boss 520. Figure 2 and Figure 3 In order to clearly show the structural features of the light-transmitting cover plate 500 , the junction between the fixing plate 510 and the first boss 520 is drawn with a dotted line.

[0039] The side edge of the fixing plate 510 is located above the step 420 of the plastic package body 400, and the fixing plate 510 is fixed to the step wall and step surface of the step 420 through the adhesive layer 600, thereby sealing and fixing the light-transmitting cover plate 500 on the plastic package body 400, so that a sealed cavity is formed between the light-transmitting cover plate 500 and the sensor chip 300. At the same time, the position of the light-transmitting cover plate 500 can be limited by the cooperation between the fixing plate 510 and the step 420 of the plastic package body 400, so as to avoid the light-transmitting cover plate 500 from contacting the photosensitive area 310 of the sensor chip 300, thereby avoiding affecting the reliability of the optical sensor packaging structure.

[0040] In some specific embodiments, the top surface of the fixing plate 510 is flush with the top surface of the plastic package body 400, or the top surface of the fixing plate 510 protrudes from the top surface of the plastic package body 400. When the package singulation process is performed, the top surface of the fixing plate 510 and the top surface of the plastic package body 400 can both contact with the cutting film, thereby increasing the contact area between the optical sensor package structure and the cutting film. When the package singulation process is performed, the optical sensor package structure and the cutting film have a high degree of adhesion, and the product is not likely to fall off when the product is singulated, thereby avoiding product cutting quality problems.

[0041] In this specific embodiment, the top surface of the fixing plate 510 is flush with the top surface of the plastic package body 400, so the area of ​​the plastic package body 400 close to the contact point with the fixing plate 510 can also contact the cutting film, further increasing the contact area between the optical sensor packaging structure and the cutting film.

[0042] In another specific embodiment, the top surface of the fixing plate 510 protrudes from the top surface of the plastic package body 400. Figure 5As shown, it is a schematic diagram of the optical sensor packaging structure provided by the second specific embodiment of the present invention. In the second specific embodiment, the top surface of the fixing plate 510 protrudes from the top surface of the plastic package body 400. When the light-transmitting cover plate 500 and the plastic package body 400 are mounted, when glue is applied to the side wall of the light-transmitting cover plate 500, the area where the fixing plate 510 is higher than the plastic package body 400 can block the glue from overflowing, thus preventing the glue from contaminating the top surface of the light-transmitting cover plate 500, thereby improving the working performance of the product. Among them, the top surface of the fixing plate 510 can be made to protrude from the top surface of the plastic package body 400 by setting the thickness of the fixing plate 510 to be greater than the distance from the step surface of the step 420 of the plastic package body 400 to the top surface of the plastic package body 400.

[0043] The first boss 520 is inserted into the optical conduction cavity 410, which reduces the space of the optical conduction cavity 410 for accommodating gas, thereby reducing the volume of gas in the optical conduction cavity 410, reducing the internal and external pressure difference when the optical sensor packaging structure is working, avoiding the transparent cover plate 500 from falling off or being damaged due to excessive internal and external pressure difference of the optical sensor packaging structure, and improving the reliability of the optical sensor packaging structure.

[0044] The first boss 520 does not contact the photosensitive area 310, that is, there is a gap between the first boss 520 and the photosensitive area 310 of the sensor chip 300, which can prevent the reliability of the optical sensor packaging structure from being affected by the transparent cover plate 500 touching the photosensitive area 310. Further, in a specific embodiment, the vertical distance from the top of the optical transmission cavity 410 to the photosensitive area 310 is greater than the height of the transparent cover plate 500, so as to further ensure that the bottom surface of the transparent cover plate 500 (that is, the bottom surface of the first boss 520) does not contact the photosensitive area 310. Further, in a specific embodiment, the vertical distance from the step surface of the step 420 to the photosensitive area 310 is greater than the height of the first boss 520, so as to further ensure that the bottom surface of the transparent cover plate 500 (that is, the bottom surface of the first boss 520) does not contact the photosensitive area 310 by limiting the step 420. In a specific implementation, the profile of the side surface of the first boss 520 is the same as the profile of the side wall of the optical conduction cavity 410 , so that the first boss 520 can be better compatible with the optical conduction cavity 410 .

[0045] In the first specific implementation, see Figure 2 to Figure 4The bottom surface of the fixing plate 510 is also provided with a second boss 530, and the second boss 530 is arranged on the periphery of the first boss 520. The step surface of the step 420 is provided with a groove 430, and the second boss 530 is inserted into the groove 430. Specifically, the second boss 530 is arranged in the overlapping area of ​​the fixing plate 510 and the step 420. At the step surface of the step 420, the groove 430 is recessed toward the inside of the plastic package 400, and the second boss 530 is inserted into the groove 430 to increase the connection strength between the light-transmitting cover plate 500 and the plastic package 400. At the same time, the cooperation between the second boss 530 and the groove 430 can also ensure that the glue does not flow into the optical transmission cavity 410 to contaminate the sensor chip 300, thereby improving the reliability of the optical sensor packaging structure.

[0046] In the first specific embodiment, the side edge of the fixing plate 510 protrudes from the side of the second boss 530, the second boss 530 is completely inserted into the groove 430, and the adhesive layer 600 is located on the outside of the second boss 530, that is, the adhesive layer 600 is arranged on the side of the fixing plate 510 and the bottom surface of the fixing plate 510 located on the outside of the second boss 530, thereby fixing the fixing plate 510 to the step wall and step surface of the step 420.

[0047] In some specific embodiments, the width of the groove 430 is the same as the width of the second boss 530, or the width of the groove 430 is greater than the width of the second boss 530. Specifically, the size of the groove 430 in the X direction is the same as the size of the second boss 530 in the X direction, or the size of the groove 430 in the X direction is greater than the size of the second boss 530 in the X direction.

[0048] For example, in the first specific embodiment, the width of the groove 430 is the same as the width of the second boss 530, the groove 430 is tightly matched with the second boss 530, and the side wall of the groove 430 is in contact with the side of the second boss 530, that is, there is no gap between the side wall of the groove 430 and the side of the second boss 530 or the gap is very small and can be ignored, which can increase the connection strength between the transparent cover plate 500 and the plastic package body 400, and when the glue layer 600 is formed by glue dripping, the glue is blocked by the second boss 530 and cannot flow into the optical conduction cavity 410, thereby avoiding the glue from flowing into the optical conduction cavity 410 to contaminate the sensor chip 300, thereby improving the reliability of the optical sensor packaging structure.

[0049] For example, in another specific embodiment, Figure 6As shown, it is a schematic diagram of the optical sensor packaging structure provided by the third specific embodiment of the present invention, the width of the groove 430 is greater than the width of the second boss 530, the side of the second boss 530 is in contact with the side wall of the groove 430 close to the first boss 520, and there is a gap between the side of the second boss 530 and the side wall of the groove 430 away from the first boss 520, then when the glue layer 600 is formed by dripping glue, the space in the groove 430 not occupied by the second boss 530 provides a holding space for the glue, and the excess glue can overflow into the groove 430, further avoiding the glue from flowing into the optical conduction cavity 410 to contaminate the sensor chip 300, thereby improving the reliability of the optical sensor packaging structure; the second boss 530 can further block the glue overflowing into the groove 430 from flowing into the optical conduction cavity 410. In other specific embodiments, there is a gap between the side of the second boss 530 and the side wall of the groove 430 close to the first boss 520, and the side of the second boss 530 contacts the side wall of the groove 430 away from the first boss 520; or, there is a gap between the side of the second boss 530 and the side wall of the groove 430.

[0050] The groove 430 is located in the inner area of ​​the step surface, or the side wall of the groove 430 facing away from the first boss 520 is flush with the step wall of the step 420. Figure 1 to Figure 6 As shown, in these specific embodiments, the groove 430 is located in the inner area of ​​the step surface, that is, the side wall of the groove 430 facing away from the first boss 520 is not flush with the step wall of the step 420. For another example, in another specific embodiment, Figure 7 As shown, it is a schematic diagram of the optical sensor packaging structure provided by the fourth specific embodiment of the present invention, the side wall of the groove 430 facing away from the first boss 520 is flush with the step wall of the step 420, the width of the groove 430 is greater than the width of the second boss 530, the side of the second boss 530 is in contact with the side wall of the groove 430 close to the first boss 520, and there is a gap between the side of the second boss 530 and the side wall of the groove 430 away from the first boss 520.

[0051] In the above specific embodiments, the side edge of the fixing plate 510 protrudes from the side of the second boss 530. In other specific embodiments of the present invention, the side of the second boss 530 facing away from the first boss 520 is flush with the side edge of the fixing plate 510. Figure 8As shown, it is a schematic diagram of the optical sensor packaging structure provided by the fifth specific embodiment of the present invention. In this specific embodiment, the side of the second boss 530 away from the first boss 520 is flush with the side edge of the fixing plate 510, that is, the side of the second boss 530 away from the first boss 520 extends downward from the side edge of the fixing plate 510. In this specific embodiment, the side wall of the groove 430 away from the first boss 520 is flush with the step wall of the step 420, the side of the second boss 530 away from the first boss 520 is fixedly connected to the side wall of the groove 430 through the glue layer 600, and the side of the second boss 530 close to the first boss 520 is in direct contact with the side wall of the groove 430, which further increases the connection strength between the transparent cover plate 500 and the plastic package body 400, and the groove 430 can provide overflow space for glue, thereby improving the reliability of the optical sensor packaging structure.

[0052] In other specific embodiments, there is a gap between the side of the second boss 530 close to the first boss 520 and the side wall of the groove 430 to further increase the space for accommodating glue. Specifically, when the amount of glue is large and the second boss 530 cannot block the glue, the gap between the side of the second boss 530 close to the first boss 520 and the side wall of the groove 430 can provide space for accommodating glue, thereby preventing the glue from flowing into the optical transmission cavity 410 and contaminating the sensor chip 300, thereby improving the reliability of the optical sensor packaging structure.

[0053] For further information, please refer to Figure 2 The height of the second boss 530 along the Z direction is smaller than the height of the first boss 520 along the Z direction. The height of the second boss 530 is smaller in order to leave enough space for the wire interconnection between the sensor chip 300 and the substrate 200 .

[0054] In the optical sensor packaging structure provided by the present invention, the volume of the gas in the optical conduction cavity is reduced by the provision of the first boss, thereby reducing the internal and external air pressure difference when the optical sensor packaging structure is working, avoiding the transparent cover plate from falling off or being damaged due to excessive internal and external air pressure difference of the optical sensor packaging structure, and improving the reliability of the optical sensor packaging structure.

[0055] It should be noted that the terms "including" and "having" and their variations involved in the document of the present invention are intended to cover non-exclusive inclusions. The terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence, unless the context clearly indicates, and it should be understood that the data used in this way can be interchanged under appropriate circumstances. The term "one or more" depends at least in part on the context, and can be used to describe features, structures or characteristics in a singular sense, or can be used to describe features, structures or combinations of features in a plural sense. The term "based on" can be understood as not necessarily intended to express a set of exclusive factors, but can alternatively, also at least in part depending on the context, allow the presence of other factors that are not necessarily explicitly described. In addition, in the absence of conflict, the specific embodiments of the present invention and the features in the specific embodiments can be combined with each other. In addition, in the above description, the description of well-known components and technologies is omitted to avoid unnecessary confusion of the concept of the present invention. In the above-mentioned various specific embodiments, each specific embodiment focuses on the differences from other specific embodiments, and the same / similar parts between the various specific embodiments can be referred to each other.

[0056] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An optical sensor packaging structure, characterized in that: include: substrate; A sensor chip is arranged on the surface of the substrate, and a surface of the sensor chip facing away from the substrate has a photosensitive area; A plastic package body, covering the surface of the substrate and encapsulating the sensor chip, wherein the plastic package body has an optical conduction cavity, the optical conduction cavity exposes the photosensitive area, and the top of the plastic package body has a step surrounding the optical conduction cavity; A light-transmitting cover plate covers the optical conduction cavity, the light-transmitting cover plate comprises a fixing plate and a first boss arranged on the bottom surface of the fixing plate, the side edge of the fixing plate protrudes from the side surface of the first boss and extends to the step, and is sealed and fixed on the step, the first boss is inserted into the optical conduction cavity and does not contact the photosensitive area.

2. The optical sensor packaging structure according to claim 1, characterized in that: The bottom surface of the fixing plate is further provided with a second boss, the second boss is arranged at the periphery of the first boss, the step surface of the step is provided with a groove, and the second boss is inserted into the groove.

3. The optical sensor packaging structure according to claim 2, characterized in that: The height of the second boss is smaller than the height of the first boss.

4. The optical sensor packaging structure according to claim 2, characterized in that: The side edge of the fixing plate protrudes from the side surface of the second boss.

5. The optical sensor packaging structure according to claim 2, characterized in that: A side surface of the second boss facing away from the first boss is flush with a side edge of the fixing plate.

6. The optical sensor packaging structure according to claim 4 or 5, characterized in that: The groove is located in the inner area of ​​the step surface.

7. The optical sensor packaging structure according to claim 4 or 5, characterized in that: The side wall of the groove facing away from the first boss is flush with the step wall of the step.

8. The optical sensor packaging structure according to claim 2, characterized in that: The width of the groove is the same as that of the second boss, or the width of the groove is greater than that of the second boss.

9. The optical sensor packaging structure according to claim 8, characterized in that: When the width of the groove is greater than the width of the second boss, the side surface of the second boss contacts the side wall of the groove close to the first boss, and a gap exists between the side surface of the second boss and the side wall of the groove away from the first boss.

10. The optical sensor packaging structure according to claim 2, characterized in that: The fixing plate is fixed on the step wall and the step surface through an adhesive layer.

11. The optical sensor packaging structure according to claim 10, characterized in that: The adhesive layer is located outside the second boss.

12. The optical sensor packaging structure according to claim 1, characterized in that: A vertical distance from the top of the optical conduction cavity to the photosensitive area is greater than a height of the light-transmitting cover plate.

13. The optical sensor packaging structure according to claim 1, characterized in that: A vertical distance from the step surface to the photosensitive area is greater than a height of the first boss.

14. The optical sensor packaging structure according to claim 1, characterized in that: The profile of the side surface of the first boss is the same as the profile of the side wall of the optical transmission cavity.

15. The optical sensor packaging structure according to claim 1, characterized in that: The top surface of the fixing plate is flush with the top surface of the plastic sealing body, or the top surface of the fixing plate protrudes from the top surface of the plastic sealing body.

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