Sensor and packaging method of sensor

Abstract

The invention relates to the technical field of sensors, in particular to a sensor and a packaging method of the sensor, the sensor comprises a circuit board, a chip and a light-transmitting plate, and the upper end of the circuit board is provided with a containing groove; the chip is arranged in the containing groove, the surface of the chip is provided with a detection area and a power connection area, the detection area is arranged in the middle of the upper end of the chip, and the power connection area and the detection area are arranged at intervals; the light-transmitting plate is connected to the upper end of the circuit board, and the light-transmitting plate is vertically opposite to the detection area and blocks the accommodating groove; the chip is not superposed on the circuit board, but is embedded in the circuit board, so that the total thickness of the sensor is reduced; moreover, the circuit board is provided with a circuit layer and a plated through hole, a conductive part is arranged in the plated through hole, one end of the conductive part is connected with the circuit layer, the other end of the conductive part abuts against the power connection area, contact type conductive connection between the chip and the circuit board is achieved through the conductive part, a lead does not need to be arranged, a lead bonding process does not need to be carried out, and the production efficiency of the sensor is improved.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a sensor and a method for packaging the sensor. Background Technology

[0002] Optical sensors such as lidar, ambient light sensors, spectral light sensors, and proximity sensors are widely used in consumer electronics, industrial automation, automotive electronics, and medical electronics. These optical sensors include circuit boards and optical chips mounted on the circuit boards.

[0003] Existing optical sensors often employ the packaging structure disclosed in Chinese invention patent CN115472640B. This structure involves bonding an optical chip with a retaining wall to the top of a circuit board, then connecting the chip's metal pads and the circuit board's gold fingers via wire bonding to achieve electrical connection between the optical chip and the circuit board. A light-transmitting plate is then placed on top of the optical chip. Finally, a molding compound is applied to the outside of the optical chip and the light-transmitting plate, thus securing them to the circuit board. The total height of the sensor formed by this packaging structure is greater than the sum of the thickness of the circuit board, the optical chip, and the light-transmitting plate. This results in a relatively thick sensor, making it difficult to meet the thickness requirements of ultra-thin electronic products. Furthermore, this packaging structure requires wire bonding for electrical connection between the chip and the circuit board, which has low production efficiency, leading to low sensor production efficiency. Summary of the Invention

[0004] The technical problem this application aims to solve is that existing sensors are relatively thick and require wire bonding, resulting in low sensor production efficiency.

[0005] To address the aforementioned technical problems, this application provides a sensor, comprising: A circuit board, the upper end of which has a receiving groove; A chip is disposed in the receiving groove. The surface of the chip has a detection area and a power-connecting area. The detection area is disposed in the upper middle part of the chip, and the power-connecting area is arranged at a distance from the detection area. A light-transmitting plate is connected to the upper end of the circuit board. The light-transmitting plate is vertically opposite to the detection area and blocks the receiving groove. The circuit board has a circuit layer and plated through holes. A conductive part is provided in the plated through holes. One end of the conductive part is connected to the circuit layer, and the other end abuts against the grounding area.

[0006] As an optional solution, the circuit board includes a first insulating layer, a substrate layer, a first circuit layer, and a first conductive portion; The first circuit layer is disposed on the upper end of the first insulating layer; the first insulating layer is disposed on the upper end of the substrate layer, the receiving groove is disposed on the upper part of the substrate layer, the first insulating layer is provided with a first light-passing hole, the first light-passing hole is vertically opposite to the detection area, and the light-transmitting plate is disposed on the first circuit layer and blocks the first light-passing hole. The contact area is located at the upper edge of the chip. The first insulating layer has a first through-hole that extends vertically. The first conductive part is located inside the first through-hole. The upper end of the first conductive part is connected to the first circuit layer, and the lower end of the first conductive part abuts against the contact area.

[0007] As an optional embodiment, the substrate layer includes a substrate, a second circuit layer, and a third circuit layer; the second circuit layer is disposed at the lower end of the substrate, the third circuit layer is disposed at the upper end of the substrate, and the insulating layer is disposed on the third circuit layer; The receiving groove is disposed on the substrate, and the third circuit layer is provided with a first via for the chip to pass through; the substrate is provided with a second plated through hole, and a second conductive part is provided in the second plated through hole, the upper end of the second conductive part is connected to the third circuit layer, and the lower end is connected to the second circuit layer.

[0008] As an optional solution, the first insulating layer is provided with a third through hole that runs vertically through the middle, and a third conductive part is provided in the third through hole. The upper end of the third conductive part is connected to the first circuit layer, and the lower end of the third conductive part is connected to the third circuit layer.

[0009] Alternatively, the first insulating layer may be a rigid plate, and the first insulating layer may be bonded to the third circuit layer and the substrate.

[0010] As an option, the sensor also includes a molding compound attached to the upper end of the circuit board, the molding compound at least partially covering the outer periphery of the light-transmitting plate.

[0011] This application also provides a sensor packaging method, including the following steps: A receiving groove is fabricated on the substrate layer of the circuit board; The chip is fixed in the receiving slot, with both the detection area and the power-connecting area of ​​the chip facing upwards; A first insulating layer is disposed on the substrate layer, the first insulating layer having a first light-passing hole opposite to the detection area; A first plated through-hole is formed on the first insulating layer, and the plated through-hole is vertically opposite to the electrical contact area; The inner wall of the plated through hole is plated with copper, so that a first conductive part is formed inside the plated through hole; Wherein, the first insulating layer is provided with a first conductive layer before being disposed on the substrate layer, or the first conductive layer is formed on the insulating layer when copper is plated onto the inner wall of the plated through hole; The first conductive layer is processed into a first circuit layer; A light-transmitting plate is placed on the first circuit layer and / or the first insulating layer to block the first light-passing hole.

[0012] As an optional solution, the first insulating layer is an insulating plate; When the first insulating layer is set on the substrate layer, a prepreg is set between the insulating plate and the substrate layer. The insulating plate is connected to the substrate layer by heating and pressurizing. During the heating and pressurizing process, the prepreg partially fills the gap between the chip and the wall of the receiving groove.

[0013] As an alternative, a water-soluble protective film is applied to the detection area of ​​the chip before it is fixed into the receiving slot; After the first conductive layer is processed into the first circuit layer and before the light-transmitting plate is fixed to the first circuit layer and / or the first insulating layer, the process includes: depositing a first insulating ink layer on the first circuit layer, such that the substrate layer, the insulating layer, the first insulating ink layer and the chip form an intermediate package, and then washing the intermediate package with water to remove the water-soluble film.

[0014] As an optional solution, fixing the light-transmitting plate after the first circuit layer and / or the first insulating layer further includes providing a molding layer on the outside of the first insulating ink layer, the molding layer at least partially covering the outer periphery of the light-transmitting plate.

[0015] Compared with the prior art, the sensor of this application has the following advantages: the upper end of the circuit board of the sensor has a receiving groove; the chip is disposed in the receiving groove, and the surface of the chip has a detection area and a power receiving area. The detection area is disposed in the middle of the upper end of the chip, and the power receiving area is arranged at intervals with the detection area; a light-transmitting plate is connected to the upper end of the circuit board, and the light-transmitting plate is vertically opposite to the detection area and blocks the receiving groove; the chip is no longer stacked on the circuit board, but embedded in the circuit board, so that the total thickness of the sensor can be reduced; moreover, the circuit board has a circuit layer and plated through holes, and conductive parts are provided in the plated through holes. One end of the conductive part is connected to the circuit layer, and the other end abuts against the power receiving area. The conductive part is used to realize the contact conductive connection between the chip and the circuit board, which does not require setting up leads or performing lead bonding processes, thereby improving the production efficiency of the sensor. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the sensor structure of this application; Figure 2 This is a schematic diagram of the original substrate structure; Figure 3 This is a schematic diagram of the original substrate structure after the second plated through-hole has been filled with copper. Figure 4 A schematic diagram of the original substrate after the second and third circuit layers have been fabricated; Figure 5 This is a schematic diagram of the structure of the original substrate forming a substrate layer after the receiving groove has been processed; Figure 6 A schematic diagram of the intermediate package formed after the chip is placed into the receiving slot; Figure 7 This is a schematic diagram illustrating the process of attaching the first insulating layer and the prepreg to the substrate layer. Figure 8 This is a schematic diagram of the intermediate package after the first insulating layer and the prepreg are connected to the substrate layer. Figure 9 A schematic diagram of the intermediate package after the first plated through-hole and the third plated through-hole are fabricated on the first conductive layer and the first insulating layer; Figure 10 A schematic diagram of the intermediate package after the first and second conductive portions are formed in the first and third plated through-holes; Figure 11 This is a schematic diagram of the intermediate package after the first conductive layer has been processed into the first circuit layer; Figure 12 A schematic diagram of the intermediate package after the first insulating ink layer is applied on the first circuit layer; Figure 13 A schematic diagram of the intermediate encapsulation body after the light-transmitting plate is bonded to the first insulating layer; Figure 14 This is a schematic diagram of the intermediate package after the molding compound layer has been applied. Figure 15 This is a schematic diagram of the intermediate package after the solder balls have been installed; Figure 16 This is a schematic diagram showing the structure of the intermediate package divided into multiple sensors; In the figure, 1. Circuit board; 11. Substrate layer; 111. Substrate; 1111. Second plated through-hole; 112. Second circuit layer; 113. Third circuit layer; 1131. First via; 114. Second conductive part; 12. First insulating layer; 121. First plated through-hole; 122. First light-passing hole; 123. Third plated through-hole; 13. First circuit layer; 14. First conductive part; 15. Third conductive part; 100. Receiving groove; 2. Chip; 21. Detection area; 22. Power-connecting area; 3. Light-transmitting plate; 4. Molding layer; 5. Prepreg; 61. Upper plating layer; 62. Lower plating layer; 63. First conductive layer; 64. First insulating ink layer; 65. Second insulating ink layer; 7. Adhesive; 8. Solder ball. Detailed Implementation

[0017] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application.

[0018] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. It should be understood that the terms "first," "second," etc., are used in this invention to describe various information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this invention, "first" information can also be referred to as "second" information, and similarly, "second" information can also be referred to as "first" information.

[0019] like Figure 1 As shown in the preferred embodiment of this application, a sensor includes a circuit board 1, a chip 2, and a light-transmitting plate 3. The upper end of the circuit board 1 has a receiving groove 100. The chip 2 is disposed in the receiving groove 100, and the surface of the chip 2 has a detection area 21 and a power receiving area 22. The detection area 21 is disposed in the middle of the upper end of the chip 2, and the power receiving area 22 is arranged at a distance from the detection area 21. The light-transmitting plate 3 is connected to the upper end of the circuit board 1, and the light-transmitting plate 3 is vertically opposite to the detection area 21 and blocks the receiving groove 100. The chip 2 is no longer stacked on the circuit board 1, but is embedded in the circuit board 1, so that the total thickness of the sensor can be reduced; it can meet the thickness requirements of ultra-thin electronic products. Furthermore, the circuit board 1 has a circuit layer and plated through holes. The plated through holes are provided with conductive parts. One end of the conductive parts is connected to the circuit layer, and the other end abuts against the electrical contact area 22. The conductive parts are used to realize the contact conductive connection between the chip 2 and the circuit board 1, which eliminates the need for lead wires and wire bonding processes, thereby improving the production efficiency of the sensor. Through the structural design of the plated through holes and conductive parts, a stable electrical connection between the chip 2 and the circuit board 1 is achieved, avoiding problems such as breakage and detachment that may occur with wire bonding, and improving the reliability of the sensor.

[0020] The circuit board 1 includes a first insulating layer 12, a substrate layer 11, a first circuit layer 13, and a first conductive portion 14. The first circuit layer 13 is disposed on the upper end of the first insulating layer 12. The first insulating layer 12 is disposed on the upper end of the substrate layer 11, and the receiving groove 100 is disposed on the upper part of the substrate layer 11. The first insulating layer 12 has a first light-passing hole 122, which is vertically opposite to the detection area 21. The light-transmitting plate 3 is disposed on the first circuit layer 13 and blocks the first light-passing hole 122. The power-connecting area 22 is disposed on the upper edge of the chip 2. The first insulating layer 12 has a first through-hole 121 that extends vertically. The first conductive portion 14 is disposed in the first through-hole 121. The upper end of the first conductive portion 14 is connected to the first circuit layer 13, and the lower end of the first conductive portion 14 abuts against the power-connecting area 22. Specifically, the outline of the first through-hole is smaller than the outer outline of the chip 2. The first insulating layer 12 covers the conductive area 22, and the first plated through-hole 121 and the conductive area 22 are vertically opposite each other. After the first insulating layer 12 is placed on the substrate layer 11, the first plated through-hole 121 is opened on the first insulating layer 12. Then, copper plating is performed to form a copper plating layer on the inner wall of the first copper plating hole, which forms the first conductive part 14. The electrical connection between the conductive area 22 and the first circuit layer 13 is achieved through the plated through-hole structure, which facilitates mass production and results in more stable molding quality.

[0021] Further, the substrate layer 11 includes a substrate 111, a second circuit layer 112, and a third circuit layer 113; the second circuit layer 112 is disposed at the lower end of the substrate 111, the third circuit layer 113 is disposed at the upper end of the substrate 111, and the insulating layer is disposed on the third circuit layer 113; the receiving groove 100 is disposed on the substrate 111, and the third circuit layer 113 has a first via 1131 for the chip 2 to pass through, the size of the first via 1131 being slightly larger than the cross-section of the chip 2; the chip 2 passes through the first via 1131 into the receiving groove 100; the substrate 111 has a second plated through hole 1111, and a second conductive portion 114 is disposed in the second plated through hole 1111, the upper end of the second conductive portion 114 being connected to the third circuit layer 113, and the lower end being connected to the second circuit layer 112. The third circuit layer 113 is arranged around the edge of the first via 1131 and does not cover the detection area 21. The second conductive part 114 leads the signal / power on the second circuit layer 112 to the third circuit layer 113.

[0022] Furthermore, the first insulating layer 12 is provided with a third through-hole 123 extending vertically. A third conductive portion 15 is provided within the third through-hole 123. The upper end of the third conductive portion 15 is connected to the first circuit layer 13, and the lower end of the third conductive portion 15 is connected to the third circuit layer 113. Specifically, the first insulating layer 12 is a thin, rigid plate made of the same material as the substrate 111, but with a thickness less than that of the substrate 111. The first insulating layer 12 is bonded to the substrate layer 11. The first insulating layer 12 can cause the chip 2 to be ejected from the receiving groove 100, thus making the chip 2 more stably positioned within the receiving groove 100.

[0023] In this embodiment, the sensor further includes a molding compound 4, which is attached to the upper end of the circuit board 1 and at least partially covers the outer periphery of the light-transmitting plate 3. Specifically, the molding compound 4 is a black light-absorbing plastic or a black colloid. The molding compound 4 can prevent stray light from entering the detection area 21 and can also improve the connection strength of the light-transmitting plate 3 on the circuit board 1.

[0024] In this embodiment, the circuit board 1 further includes a first insulating ink layer 64, which is disposed on the first circuit layer 13. Adhesive 7 is provided on the lower periphery of the light-transmitting plate 3, and the light-transmitting plate 3 is bonded to the first circuit layer 13 and the first insulating ink layer 64 by means of adhesive 7.

[0025] In this embodiment, a second insulating ink layer 65 is provided at the lower end of the second circuit layer 112. The second insulating ink layer 65 has a window that exposes the contacts of the second circuit layer 112, through which the circuit board 1 is powered. In some embodiments of this application, solder balls 8 are also connected to the lower end of the contacts. The entire sensor can be mounted on the main control circuit board 1 through these solder balls 8, just like a BGA chip 2.

[0026] This application also provides an embodiment of a sensor packaging method, such as... Figures 2 to 16 As shown, it includes the following steps: A receiving groove 100 is formed on the substrate layer 11 of the circuit board 1; The chip 2 is fixed in the receiving groove 100, with the detection area 21 and the power receiving area 22 of the chip 2 facing upwards; A first insulating layer 12 is provided on the substrate layer 11, and the first insulating layer 12 has a first light-passing hole 122 opposite to the detection area 21. A first plated through-hole 121 is formed on the first insulating layer 12, and the plated through-hole is vertically opposite to the electrical contact area 22. The inner wall of the plated through hole is plated with copper, so that a first conductive part 14 is formed inside the plated through hole; The first insulating layer 12 is provided with a first conductive layer 63 before being disposed on the substrate layer 11, or the first conductive layer 63 is formed on the insulating layer when copper is plated onto the inner wall of the plated through hole. The first conductive layer 63 is processed into the first circuit layer 13; The light-transmitting plate 3 is placed on the first circuit layer 13 and / or the first insulating layer 12 to block the third light-passing hole; the lower edge of the light-transmitting plate 3 is bonded to the first insulating layer 12. If the first circuit layer 13 exists at the position opposite to the light-transmitting plate 3, the lower end of the light-transmitting plate 3 will also be bonded to the first circuit layer 13.

[0027] The sensor packaging method of this application involves processing a receiving groove 100 on the substrate layer 11 of the circuit board 1 and placing the chip 2 in the receiving groove 100, which allows the overall thickness of the sensor to be set to be relatively thin. The first conductive layer 63 and the grounding area 22 are connected by the first conductive part 14, so that the sensor does not need to be wire bonded during the packaging process, thereby improving the production efficiency of the sensor.

[0028] Furthermore, the first insulating layer 12 is an insulating plate. When the first insulating layer 12 is disposed on the substrate layer 11, a prepreg is disposed between the insulating plate and the substrate layer 11. The insulating plate is connected to the substrate layer 11 by heating and pressurizing. During the heating and pressurizing process, the prepreg partially fills the gap between the chip 2 and the wall of the receiving groove 100. The prepreg not only bonds the insulating plate and the substrate layer 11, but also fills the gap between the chip 2 and the wall of the receiving groove 100, improving the connection stability between the chip 2 and the substrate layer 11. By setting the first insulating layer 12 as an insulating plate, the first insulating layer 12 can prevent the chip 2 from falling out of the receiving groove 100, further improving the connection stability between the chip 2 and the substrate layer 11.

[0029] Because the detection area 21 needs to have good cleanliness and smoothness to ensure that the chip 2 can normally receive and emit light, in this embodiment, before fixing the chip 2 into the receiving groove 100, a water-soluble protective film is covered on the detection area 21 of the chip 2; the water-soluble protective film can prevent subsequent processes from contaminating the detection area 21. After the first conductive layer 63 is processed into the first circuit layer 13 and before the light-transmitting plate 3 is fixed to the first circuit layer 13 and / or the first insulating layer 12, the process includes: setting a first insulating ink layer 64 on the first circuit layer 13, so that the substrate layer 11, the insulating layer, the first ink layer and the chip 2 form an intermediate package, and then washing the intermediate package with water to remove the water-soluble film.

[0030] Specifically, after removing the water-soluble film, the intermediate encapsulation body is dried to remove moisture from it, ensuring that there is no moisture in the receiving tank 100 after the light-transmitting plate 3 is sealed in the receiving tank 100, thus avoiding the influence of moisture on the light absorption and emission.

[0031] In this embodiment, after fixing the light-transmitting plate 3 to the first circuit layer 13 or the first insulating layer 12, a molding compound 4 is disposed on the outside of the first ink layer. The molding compound 4 at least partially covers the outer periphery of the light-transmitting plate 3. The molding compound 4 can be manufactured by injection molding or glue injection. During injection molding, the intermediate encapsulation body after the light-transmitting plate 3 is installed needs to be placed into the injection mold.

[0032] In this embodiment, the substrate layer 11 includes a substrate 111, a second circuit layer 112, and a third circuit layer 113; the second circuit layer 112 is disposed at the lower end of the substrate 111, the third circuit layer 113 is disposed at the upper end of the substrate 111, and the insulating layer is disposed on the third circuit layer 113; the receiving groove 100 is disposed on the substrate 111, and the third circuit layer 113 is provided with a first via 1131 for the chip 2 to pass through; the substrate 111 is provided with a second plated through hole 1111, and a second conductive part 114 is provided in the second plated through hole 1111, the upper end of the second conductive part 114 is connected to the third circuit layer 113, and the lower end is connected to the second circuit layer 112.

[0033] A second insulating ink layer 65 is also provided at the lower end of the second circuit layer 112. After the second circuit layer 112 is processed, the second insulating ink layer 65 is applied to the lower end of the second circuit layer 112. The second insulating ink layer 65 has windows that expose the contacts of the second circuit layer 112, through which the circuit board 1 is powered. In some embodiments of this application, solder balls 8 are also connected to the lower end of the contacts, and the entire sensor can be mounted on the main control circuit board 1 through these solder balls 8, just like a BGA chip 2.

[0034] In this embodiment, the entire packaging process for the sensor includes the following steps: Step S1: Cut out a raw substrate 111 of a specified size. The raw substrate 111 includes a substrate 111, an upper copper layer disposed at the upper end of the substrate 111, and a lower copper layer disposed at the lower end of the substrate 111. Step S2: Open a second through hole 1111 that runs vertically through the original substrate 111. This can be done by mechanical drilling or laser drilling. Then, plate copper on the original substrate 111 to connect the upper copper layer and the lower copper layer. Step S3: Process the upper copper layer into the third circuit layer 113 and the lower copper layer into the second circuit layer 112; the corresponding circuit layers can be formed by pressing dry film, exposure, development, and etching stripping. Step S4: A receiving groove 100 is formed at the location where the chip 2 needs to be placed. Multiple receiving grooves 100 are provided on a substrate layer 11, and the receiving grooves 100 are arranged in a matrix with uniform spacing. For ease of observation, this application specification... Figures 2 to 12 The selected diagram is a structural schematic of a single packaging unit. Figures 13 to 16 The rotating diagram shows the structure of two adjacent packaging units, each packaging unit having a receiving slot 100.

[0035] Step S5: Place chip 2 into receiving tank 100. Before this, the detection area 21 of chip 2 has been covered by a water-soluble film; the lower end of chip 2 is attached to the bottom wall of receiving tank 100. Step S6: The first insulating layer 12 is adhered to the third circuit layer 113 and the substrate 111 by means of a prepreg. In this embodiment, the first insulating layer 12 has a first conductive layer 63 attached to it. Step S7: Open a first plated through hole 121 and a third plated through hole 123 on the first insulating layer 12 and the first conductive layer 63; Step S8: Copper is plated in the first plated through hole 121 and the third plated through hole 123 to connect the first conductive layer 63 and the third circuit layer 113, as well as the power receiving area 22 and the first conductive layer 63. Step S9: Process the first conductive layer 63 into the first circuit layer 13; Step S10: A first insulating ink layer 64 is provided on the first circuit layer 13, and a second insulating ink layer 65 is provided at the lower end of the second circuit layer 112; so as to protect the first circuit layer 13 and the second circuit layer 112. Then, windows are created by etching in the water-soluble film and in the areas where they need to be used as contacts. Step S11: Plate nickel and gold onto the windowed area that serves as the contact point to prevent oxidation of the contact point; Step S12: Wash the intermediate package formed by the above treatment with water to remove the water-soluble protective film, and then dry it. Step S13: Adhere the light-transmitting plate 3 to the first insulating ink layer 64 and / or the first circuit layer 13; Step S14: Apply plastic sealant or adhesive to the gap between two adjacent light-transmitting plates 3; Step S15: For sensors that require solder balls 8, place the balls on the contacts; this step is optional. Step S16: Cut the intermediate package into multiple independent sensors.

[0036] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application.

Claims

1. A sensor, characterized in that, include: Circuit board (1), the upper end of which has a receiving groove (100); A chip (2) is disposed in the receiving groove (100). The surface of the chip (2) has a detection area (21) and a power receiving area (22). The detection area (21) is disposed in the middle of the upper end of the chip (2), and the power receiving area (22) is arranged at a distance from the detection area (21). A light-transmitting plate (3) is connected to the upper end of the circuit board (1). The light-transmitting plate (3) is vertically opposite to the detection area (21) and blocks the receiving groove (100). The circuit board (1) has a circuit layer and plated through holes. A conductive part is provided in the plated through holes. One end of the conductive part is connected to the circuit layer, and the other end abuts against the power receiving area (22).

2. The sensor according to claim 1, characterized in that, The circuit board (1) includes a first insulating layer (12), a substrate layer (11), a first circuit layer (13), and a first conductive part (14). The first circuit layer (13) is disposed on the upper end of the first insulating layer (12); the first insulating layer (12) is disposed on the upper end of the substrate layer (11), the receiving groove (100) is disposed on the upper part of the substrate layer (11), the first insulating layer (12) is provided with a first light-passing hole (122), the first light-passing hole (122) is vertically opposite to the detection area (21), and the light-transmitting plate (3) is disposed on the first circuit layer (13) and blocks the first light-passing hole (122). The contact area (22) is located at the upper edge of the chip (2). The first insulating layer (12) has a first through hole (121) that runs vertically through the chip. The first conductive part (14) is located inside the first through hole (121). The upper end of the first conductive part (14) is connected to the first circuit layer (13), and the lower end of the first conductive part (14) abuts against the contact area (22).

3. The sensor according to claim 2, characterized in that, The substrate layer (11) includes a substrate (111), a second circuit layer (112) and a third circuit layer (113); the second circuit layer (112) is disposed at the lower end of the substrate (111), the third circuit layer (113) is disposed at the upper end of the substrate (111), and the insulating layer is disposed on the third circuit layer (113); The receiving groove (100) is disposed on the substrate (111), and the third circuit layer (113) is provided with a first via (1131) for the chip (2) to pass through; the substrate (111) is provided with a second plated through hole (1111), and a second conductive part (114) is provided in the second plated through hole (1111). The upper end of the second conductive part (114) is connected to the third circuit layer (113), and the lower end is connected to the second circuit layer (112).

4. The sensor according to claim 3, characterized in that, The first insulating layer (12) is provided with a third plated through hole (123) that runs vertically through the top and bottom. A third conductive part (15) is provided in the third plated through hole (123). The upper end of the third conductive part (15) is connected to the first circuit layer (13), and the lower end of the third conductive part (15) is connected to the third circuit layer (113).

5. The sensor according to claim 4, characterized in that, The first insulating layer (12) is a rigid plate, and the first insulating layer (12) is bonded to the third circuit layer (113) and the substrate (111).

6. The sensor according to claim 1, characterized in that, The sensor also includes a molding compound (4) which is attached to the upper end of the circuit board (1) and at least partially covers the outer periphery of the light-transmitting plate (3).

7. A sensor packaging method, characterized in that, Includes the following steps: A receiving groove (100) is processed on the substrate layer (11) of the circuit board (1). The chip (2) is fixed in the receiving slot (100) so that the detection area (21) and the power receiving area (22) of the chip (2) are both arranged facing upwards; A first insulating layer (12) is provided on the substrate layer (11), and the first insulating layer (12) has a first light-passing hole (122) opposite to the detection area (21). A first plated through hole (121) is formed on the first insulating layer (12), and the plated through hole is vertically opposite to the electrical contact area (22); The inner wall of the plated through hole is plated with copper, so that a first conductive part (14) is formed inside the plated through hole. The first insulating layer (12) is provided with a first conductive layer (63) before being disposed on the substrate layer (11), or the first conductive layer (63) is formed on the insulating layer when copper is plated onto the inner wall of the plated through hole. The first conductive layer (63) is processed into the first circuit layer (13); The light-transmitting plate (3) is placed on the first circuit layer (13) and / or the first insulating layer (12) to block the first light-passing hole (122).

8. The sensor packaging method according to claim 7, characterized in that, The first insulating layer (12) is an insulating plate; When a first insulating layer (12) is provided on the substrate layer (11), a prepreg is provided between the insulating plate and the substrate layer (11). The insulating plate is connected to the substrate layer (11) by heating and pressurizing. During the heating and pressurizing process, the prepreg partially fills the gap between the chip (2) and the groove wall of the receiving groove (100).

9. The sensor packaging method according to claim 8, characterized in that, Before fixing the chip (2) into the receiving groove (100), a water-soluble protective film is covered on the detection area (21) of the chip (2); After the first conductive layer (63) is processed into the first circuit layer (13) and before the light-transmitting plate (3) is fixed to the first circuit layer (13) and / or the first insulating layer (12), the process includes: providing a first insulating ink layer (64) on the first circuit layer (13) such that the substrate layer (11), the insulating layer, the first insulating ink layer (64) and the chip (2) form an intermediate package, and then washing the intermediate package with water to remove the water-soluble film.

10. The sensor packaging method according to claim 9, characterized in that, After fixing the light-transmitting plate (3) to the first circuit layer (13) and / or the first insulating layer (12), a molding compound (4) is provided on the outside of the first insulating ink layer (64), the molding compound (4) at least partially covering the outer periphery of the light-transmitting plate (3).

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