A high-integration laser radar chip packaging structure and method

Abstract

The application provides a high-integration laser radar chip packaging structure and method, which can reduce the size of the whole packaging structure, meet the characteristics of the product, avoid mutual interference between signals, and improve the safety and stability of the packaging structure. The application comprises a packaging body, an RDL substrate and a laser radar chip arranged in the packaging body; a first driving chip is welded on the surface of the RDL substrate, a receiving groove is formed on the surface of the RDL substrate, and a second driving chip is welded on the surface of the receiving groove; the laser radar chip comprises a transmitting chip and a receiving chip, the transmitting chip and the receiving chip are connected with the first driving chip and the second driving chip in correspondence, the other side of the transmitting chip is connected with a coated glass, the receiving chip and the second driving chip form a laser radar receiving sensor unit, a coated glass cover is arranged on the laser radar receiving sensor unit, and the two side bottoms of the coated glass cover are connected with the inner wall of the receiving groove; wherein the surface of the coated glass and the top surface of the coated glass cover are exposed from the packaging body.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit packaging technology, specifically to a highly integrated lidar chip packaging structure and method. Background Technology

[0002] Traditional satellite remote sensing measurements can collect information up to ten meters below the sea surface. In order to explore the situation in deeper parts of the ocean, humans have begun to develop increasingly advanced lidar detection technology. Lidar emits laser pulses of specific wavelengths required for ocean monitoring and uses receivers with sensitive detectors to measure backscattered or reflected light and calculate the time it takes for the beam to hit a particle and bounce back, thus sensing the distance to particles in the seawater.

[0003] LiDAR typically consists of a light source transmitter, a receiver, and a signal processing unit. Currently, a significant amount of research and development focuses on lidar transmitters, such as VCSEL packaging, with circuit structures including laser emission chips and driver chips, greatly advancing the research progress of Time-of-Flight (ToF) radar. However, unmanned devices using the same wavelength can interfere with each other, affecting detection performance, and are highly susceptible to weather conditions. Furthermore, with the increasing integration of electronic chips and the miniaturization of electronic components, the existing lidar transmitter packaging size can no longer meet the demands. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a highly integrated lidar chip packaging structure and method, which can reduce the size of the entire packaging structure while meeting the characteristics of the product, avoiding mutual interference between signals, and improving the security and stability of the packaging structure.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A highly integrated lidar chip packaging structure includes a package body and an RDL substrate and a lidar chip disposed within the package body.

[0007] A first driver chip is soldered onto the surface of the RDL substrate, and a receiving groove is formed on the surface of the RDL substrate. A second driver chip is soldered onto the surface of the receiving groove.

[0008] The lidar chip includes a transmitting chip and a receiving chip, which are respectively connected to a first driving chip and a second driving chip. A coated glass is attached to the other side of the transmitting chip. The lidar receiving sensing unit formed by the receiving chip and the second driving chip is covered with a coated glass cover, and the bottom sides of the coated glass cover are connected to the inner wall of the receiving slot.

[0009] The surface of the coated glass and the top surface of the coated glass cover both expose the encapsulation body;

[0010] The package also includes electrical interconnect structures for interconnecting the lidar chips with each other and with the lidar chip and the RDL substrate.

[0011] Preferably, the surface of the RDL substrate is connected to the first driver chip via solder balls, and the surface of the receiving slot is connected to the second driver chip via solder balls.

[0012] Preferably, the transmitting chip and the receiving chip are respectively attached to the first driving chip and the second driving chip using adhesive containing Ag ions.

[0013] Preferably, the coated glass is attached to the transmitting chip using transparent film or transparent adhesive.

[0014] Preferably, the receiving slot is located in the middle of the RDL substrate.

[0015] Preferably, the bottom sides of the coated glass cover are engaged or bonded to the inner wall of the receiving groove.

[0016] Preferably, the surface of the coated glass and the top surface of the coated glass cover are flush with the top surface of the package.

[0017] A highly integrated lidar chip packaging method includes the following steps:

[0018] A receiving groove is formed on one side surface of the RDL substrate;

[0019] A first driver chip is soldered to one side of the RDL substrate where a receiving slot is formed. A transmitter chip is attached to the other side of the first driver chip. A coated glass that has undergone a coating process is attached to the other side of the transmitter chip.

[0020] A second driving chip is soldered onto the surface of the receiving slot, and a receiving chip is attached to the other side of the second driving chip to form a lidar receiving and sensing unit.

[0021] The lidar chips are interconnected with each other and with the RDL substrate through an electrical interconnection structure.

[0022] A coated glass cover, which has undergone a coating process, is placed over the outside of the lidar receiving and sensing unit, and the cavity formed inside the coated glass cover is vacuum sealed.

[0023] The RDL substrate and the LiDAR chip are encapsulated in an openmolding process, with the surface of the coated glass and the top surface of the coated glass cover exposed, thus completing the encapsulation.

[0024] Preferably, the coating process includes depositing one or more thin films composed of metals such as chromium, titanium, indium or tin and their compounds on the glass surface by chemical vapor deposition, vacuum magnetron sputtering or vacuum evaporation to form coated glass and coated glass cover.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention provides a highly integrated lidar chip packaging structure with detection accuracy independent of weather conditions, applicable to marine monitoring. By soldering a first and second driver chip onto the substrate of an RDL substrate to connect the lidar chip's transmitting and receiving chips, the transmitting and receiving sensors of the lidar are integrated into a single package. Specifically, by creating a receiving slot on the RDL substrate and soldering a second driver chip onto the surface of the slot for bonding the lidar receiving chip, the overall package size can be further reduced while still meeting product requirements. Simultaneously, a coated glass layer treated with a special coating process is attached to the surface of the lower-layer lidar transmitting chip, improving the transmittance of the required light source and directly filtering out interference wavelengths from certain self-emitting sources in the deep sea. Furthermore, a coated glass cover capable of receiving light sources of specific wavelengths is placed outside the lidar receiving sensor unit, and a vacuum sealing process is used to isolate and protect the lidar receiving sensor unit. This maximizes the utilization of the lidar receiving chip's area and provides mechanical support, improving the safety and stability of the packaging structure. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the RDL substrate structure after slotting and wiring according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the RDL substrate structure after chip mounting according to an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the RDL substrate structure after wire bonding according to an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the RDL substrate structure after isolation and protection of the lidar receiving sensor unit according to an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the encapsulated lidar chip packaging structure according to an embodiment of the present invention.

[0032] In the figure, 1 is the RDL substrate, 2 is the receiving slot, 3 is the first driving chip, 4 is the second driving chip, 5 is the transmitting chip, 6 is the receiving chip, 7 is the electrical interconnect structure, 8 is the coated glass, 9 is the coated glass cover, 10 is the package, 11 is the transparent film, 12 is the transparent adhesive, 13 is the sealant, and 14 is the solder ball. Detailed Implementation

[0033] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] The present invention will now be described in further detail with reference to the accompanying drawings:

[0036] like Figure 5 As shown, the present invention provides a highly integrated lidar chip packaging structure, including a package 10 and an RDL substrate 1 and a lidar chip disposed within the package 10.

[0037] A first driver chip 3 is soldered onto the surface of the RDL substrate 1, and a receiving groove 2 is formed on the surface of the RDL substrate 1. A second driver chip 4 is soldered onto the surface of the receiving groove 2.

[0038] The lidar chip includes a transmitting chip 5 and a receiving chip 6, which are respectively connected to a first driving chip 3 and a second driving chip 4. A coated glass 8 is connected to the other side of the transmitting chip 5. The lidar receiving sensing unit formed by the receiving chip 6 and the second driving chip 4 is covered with a coated glass cover 9. The bottom sides of the coated glass cover 9 are connected to the inner wall of the receiving groove 2.

[0039] The surface of the coated glass 8 and the top surface of the coated glass cover 9 are both exposed above the encapsulation body 10;

[0040] The package 10 also includes an electrical interconnection structure 7 for interconnecting the lidar chips with each other and with the lidar chips and the RDL substrate 1.

[0041] This invention provides a highly integrated lidar chip packaging structure with detection accuracy independent of weather conditions, applicable to marine monitoring. By soldering a first driver chip 3 and a second driver chip 4 onto the substrate of an RDL substrate 1 to connect the lidar chip's transmitting chip 5 and receiving chip 6, the transmitting and receiving sensors of the lidar are integrated into a single package. Specifically, by creating a receiving slot 2 on the RDL substrate 1 and soldering the second driver chip 4 onto the surface of the receiving slot 2 for bonding the lidar receiving chip 6, the overall package size can be further reduced while still meeting product requirements. Simultaneously, a coated glass 8, treated with a special coating process, is attached to the surface of the lower lidar transmitting chip 5, improving the transmittance of the required light source and directly filtering interference wavelengths from certain self-luminous sources in the deep sea. Furthermore, a coated glass cover 9, capable of receiving light sources of specific wavelengths, is placed outside the lidar receiving sensor unit, and a vacuum sealing process is used to isolate and protect the lidar receiving sensor unit. This maximizes the utilization of the lidar receiving chip 6 area and provides mechanical support, improving the safety and stability of the packaging structure.

[0042] In this embodiment, the surface of the RDL substrate 1 is connected to the first driver chip 3 via solder balls 14, and the surface of the receiving groove 2 is connected to the second driver chip 4 via solder balls 14.

[0043] Preferably, the transmitting chip 5 and the receiving chip 6 are respectively bonded to the first driving chip 3 and the second driving chip 4 using adhesive containing Ag ions; the addition of an appropriate amount of Ag ions to the adhesive of the present invention can improve the heat dissipation effect of the laser chip, increase the response speed, and improve the integrity of signal transmission.

[0044] Preferably, the coated glass 8 is attached to the emitting chip 5 using a transparent film 11, such as a die-attached film (DAF) or transparent adhesive 12. The use of transparent adhesive or film for attachment in this invention will not affect the light transmittance of the glass.

[0045] Furthermore, the receiving slot 2 is located in the middle of the RDL substrate 1. Considering that the transmitting chip 5 and the receiving chip 6 are similar in size, and the receiving chip 6 located in the receiving slot 2 will have a coated glass cover 9 attached to its outside, the slot is located near the middle of the RDL substrate 1. This will make the stress more uniform and may improve or avoid the disadvantage of substrate warping after packaging.

[0046] Preferably, the transmitting chip 5 may be a chip with a transmitting wavelength of 515nm, 690nm, 759nm, 1030nm, 1380nm, 1595nm or 2760nm, but is not limited to these.

[0047] Preferably, the bottom sides of the coated glass cover 9 are engaged or bonded to the inner wall of the receiving groove 2.

[0048] Furthermore, the surface of the coated glass 8 and the top surface of the coated glass cover 9 are flush with the top surface of the package 10.

[0049] This invention also provides a highly integrated lidar chip packaging method, comprising the following steps:

[0050] A receiving groove 2 is formed on one side surface of the RDL substrate 1;

[0051] A first driving chip 3 is soldered on one side of the RDL substrate 1 where a receiving groove 2 is formed. A transmitting chip 5 is attached to the other side of the first driving chip 3. A coated glass 8 that has undergone a coating process is attached to the other side of the transmitting chip 5.

[0052] A second driving chip 4 is soldered onto the surface of the receiving slot 2, and a receiving chip 6 is attached to the other side of the second driving chip 4 to form a lidar receiving and sensing unit.

[0053] The lidar chips are interconnected with each other and with the RDL substrate 1 through the electrical interconnection structure 7.

[0054] The coated glass cover 9, which has undergone a coating process, is placed on the outside of the lidar receiving and sensing unit, and the cavity formed inside the coated glass cover 9 is vacuum sealed.

[0055] The RDL substrate 1 and the LiDAR chip are encapsulated in the package 10 using an openmolding process, exposing the surface of the coated glass 8 and the top surface of the coated glass cover 9.

[0056] Furthermore, the vacuum sealing treatment of the cavity formed inside the coated glass cover 9 includes applying sealant 13 to the connection between the bottom sides of the coated glass cover 9 and the inner wall of the receiving groove 2 to improve the sealing effect of the coated glass cover 9.

[0057] Furthermore, coating refers to depositing a very thin transparent film on the glass surface, which can produce corresponding transmittance for light of the desired wavelength according to different processes, while blocking the transmission of unwanted wavelength light. In this invention, one or more thin film systems composed of metals such as chromium, titanium, indium or tin and their compounds can be deposited on the glass surface by chemical vapor deposition (CVD), vacuum magnetron sputtering, or vacuum evaporation to form coated glass 8 and coated glass cover 9.

[0058] Example

[0059] The present invention provides a specific implementation method according to an embodiment, and the specific implementation steps are as follows:

[0060] Step 1: As Figure 1 As shown, an organic substrate is prepared, and a slot is cut near the center of the substrate to house the lidar receiving sensor, further reducing the overall package size. The substrate is then wired using RDL (Radio Directional Layer) wiring technology to facilitate electrical connections between the chip, the substrate, and external circuitry.

[0061] Step 2: As Figure 2 As shown, the FC (Flip Chip) process is used to solder all the driver chips to be installed onto the metal pad area of ​​the RDL substrate 1 after the wiring is completed.

[0062] In this process, the laser receiver chip 6 and the transmitter chip 5 are attached to the surface of their respective underlying driver chips using adhesive containing Ag ions. Adding an appropriate amount of Ag ions to the adhesive can improve the heat dissipation of the laser chip, increase the response speed, and improve the integrity of signal transmission.

[0063] In this process, a coated glass 8 with a special coating process is attached to the surface of the lower laser emitting chip 5 using transparent DAF (Die Attach Film) or transparent glue 12. The coated glass 8 with the special coating process can improve the transmittance of the required light source and directly filter the interference wavelength of some self-luminous sources in the deep sea.

[0064] Among them, the laser emitting chip 5 used for marine monitoring may emit wavelengths including, but not limited to, 515nm, 690nm, 759nm, 1030nm, 1380nm, 1595nm or 2760nm, which shall be selected and used according to the actual situation.

[0065] Step 3: As Figure 3 As shown, using wire bonding technology, through electrical interconnection structure 7, in this embodiment, gold wire or other metal wires are used to interconnect chips with each other, including receiving chip 6 and transmitting chip 5, or interconnection between chips in this package structure and chips on other substrates, as well as interconnection between chips and substrates.

[0066] Step 4: As Figure 4 As shown, a coated glass cover 9, which can receive light sources of special wavelengths after coating process, is embedded in the slot of RDL substrate 1 and covers the lidar receiving and sensing unit. The lidar receiving and sensing unit is isolated and protected by vacuum sealing process, maximizing the use of the lidar receiving chip 6 area and providing mechanical support.

[0067] Step 5: As Figure 5As shown, the open molding process is used to expose the coated glass 8 and the coated glass cover 9, and to form them flush with the molding resin of the encapsulation body 10, thereby realizing the transmission of light source and the response of signal, and the encapsulation is completed.

[0068] Step 6: Stamp the RDL substrate 1 after it has been encapsulated.

[0069] Step 7: Cut the encapsulated RDL substrate 1 into individual products.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A high integration laser radar chip package structure, characterized in that, The package (10) comprises an RDL substrate (1) and a laser radar chip arranged in the package (10). The surface of the RDL substrate (1) is welded with a first driving chip (3), and the surface of the RDL substrate (1) is provided with a receiving groove (2), and the surface of the receiving groove (2) is welded with a second driving chip (4). The laser radar chip comprises a transmitting chip (5) and a receiving chip (6), and the transmitting chip (5) and the receiving chip (6) are correspondingly connected with the first driving chip (3) and the second driving chip (4), respectively, and the other side of the transmitting chip (5) is connected with a coated glass (8), and the laser radar receiving sensor unit formed by the receiving chip (6) and the second driving chip (4) is provided with a coated glass cover (9), and the two side bottoms of the coated glass cover (9) are connected with the inner wall of the receiving groove (2), wherein the surface of the coated glass (8) and the top surface of the coated glass cover (9) are exposed from the package (10). The package (10) further comprises an electrical interconnection structure (7) for realizing the interconnection between the laser radar chips and between the laser radar chips and the RDL substrate (1). The surface of the coated glass (8) and the top surface of the coated glass cover (9) are flush with the top surface of the package (10). The receiving groove (2) is arranged at the middle position of the RDL substrate (1), and the two side bottoms of the coated glass cover (9) are clamped or bonded with the inner wall of the receiving groove (2).

2. The high integration laser radar chip package structure according to claim 1, wherein, The surface of the RDL substrate (1) is connected with the first driving chip (3) through solder balls (14), and the surface of the receiving groove (2) is connected with the second driving chip (4) through solder balls (14).

3. The high integration laser radar chip package structure according to claim 1, wherein, The transmitting chip (5) and the receiving chip (6) are respectively pasted on the first driving chip (3) and the second driving chip (4) by using Ag-ion-containing die bonding glue.

4. The high integration laser radar chip package structure according to claim 1, wherein, The coated glass (8) is pasted on the transmitting chip (5) by using transparent adhesive film (11) or transparent adhesive (12).

5. A high integration laser radar chip packaging method, characterized in that, The package structure according to any one of claims 1-4 comprises the following steps, a receiving groove (2) is arranged on one side surface of the RDL substrate (1); a first driving chip (3) is welded on one side surface of the RDL substrate (1) where the receiving groove (2) is arranged, and the other side of the first driving chip (3) is pasted with a transmitting chip (5), and the other side of the transmitting chip (5) is pasted with a coated glass (8) treated by a coating process; a second driving chip (4) is welded on the surface of the receiving groove (2), and the other side of the second driving chip (4) is pasted with a receiving chip (6) to form a laser radar receiving sensor unit; the laser radar chips and the RDL substrate (1) are interconnected through an electrical interconnection structure (7); a coated glass cover (9) treated by a coating process is arranged outside the laser radar receiving sensor unit, and the cavity formed in the coated glass cover (9) is vacuum sealed; and An open molding plastic packaging process is adopted to wrap the RDL substrate (1) and the laser radar chip in a package (10), and make the surface of the coated glass (8) and the top surface of the coated glass cover (9) exposed, and the packaging is completed; The coating process includes coating one or more layers of thin film composed of metal and its compound of chromium, titanium, indium or tin on the surface of the glass by chemical vapor deposition method, vacuum magnetron sputtering method or vacuum evaporation method, to form the coated glass (8) and the coated glass cover (9).

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