Area array laser emission module and laser radar

Abstract

The invention relates to an area array laser emission module and a laser radar, the area array laser emission module comprises a driving chip, and the driving chip comprises a driving circuit; the laser chip is stacked on the surface of the driving chip, and the laser chip comprises a laser substrate, a first electrode, a second electrode, a third electrode and a fourth electrode; the plurality of laser units are positioned on one side, far away from the driving chip, of the laser substrate; and the connecting column penetrates through the laser substrate so as to realize electric connection between the laser unit and the driving circuit. According to the technical scheme, the routing length can be effectively shortened, the routing width can be increased, the parasitic resistance of the loop can be remarkably reduced, the routing length is greatly shortened, the loop area can be effectively reduced, the loop inductance can be reduced, the pulse width of emitted laser can be effectively reduced, and the distance measuring capacity of the laser radar can be guaranteed.

Description

Technical Field

[0001] The invention relates to laser detection, and in particular to a planar array laser emission module and a laser radar. Background Art

[0002] LiDAR is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. It is widely used in autonomous driving, intelligent robots, surveying and mapping, etc. All-solid-state LiDAR has the advantages of small size and low cost, and has attracted much attention from the industry. All-solid-state LiDAR usually uses an array light source, but the array light source is often prone to large parasitic inductance and parasitic resistance. That is, the parasitic inductance and parasitic resistance in the light-emitting circuit of each light source are different and vary greatly, resulting in uneven luminous intensity of multiple light sources in the array light source, thereby affecting the detection performance of the LiDAR. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a planar array laser emission module, comprising:

[0004] A driving chip, the driving chip comprising a driving circuit; a laser chip, the laser chip being stacked on a surface of the driving chip, the laser chip comprising: a laser substrate; a plurality of laser units, the laser units being located on a side of the laser substrate away from the driving chip; and a connecting column, the connecting column penetrating the laser substrate to achieve electrical connection between the laser units and the driving circuit.

[0005] Optionally, the aspect ratio of the connecting column is less than 1.

[0006] Optionally, the connecting column is made of copper.

[0007] Optionally, the laser substrate is a gallium arsenide substrate.

[0008] Optionally, the laser unit includes: a first electrode, an active layer and a second electrode, wherein the first electrode, the active layer and the second electrode are stacked in sequence on the laser substrate; one end of the connecting column is electrically connected to the first electrode, and the other end is exposed from a surface of the laser substrate away from the laser unit.

[0009] Optionally, in a plane parallel to the surface of the laser substrate, the projection of the active layer is within the range of the projection of the first electrode; the connecting column also penetrates the first electrode and is exposed from the surface of the first electrode away from the laser substrate.

[0010] Optionally, the second electrodes of the plurality of laser units are electrically connected.

[0011] Optionally, the laser chip further includes: at least one upper bus, the upper bus is located on a side of the laser unit away from the laser substrate, and each of the upper bus is connected to the second electrodes of a plurality of the laser units.

[0012] Optionally, the laser chip includes one upper bus, and the upper bus is connected to the second electrodes of all the laser units.

[0013] Optionally, the driving chip includes a plurality of driving circuits; the first electrodes of the plurality of laser units and the plurality of driving circuits are electrically connected in a one-to-one correspondence via the connecting pillars.

[0014] Optionally, the driving chip further includes a plurality of lower bus lines, wherein the lower bus lines are located on a side of the first electrode away from the laser substrate, and each of the lower bus lines is connected to the first electrodes of a plurality of the laser units.

[0015] Optionally, the laser chip has a plurality of driving groups, each of the driving groups includes at least one laser unit, and the second electrodes of the laser units in the same driving group are electrically connected.

[0016] Optionally, the laser chip includes multiple upper-layer buses, and the second electrodes of all the laser units in the same driving group are connected to the same upper-layer bus; and the first electrodes of the laser units in the same driving group are respectively connected to different lower-layer buses.

[0017] Optionally, the driving chip includes multiple first driving circuits and multiple second driving circuits; multiple lower-layer buses are electrically connected to different first driving circuits through the connecting columns; and multiple upper-layer buses are electrically connected to different second driving circuits through the connecting columns.

[0018] Optionally, the driving chip includes: a chip substrate, and the chip substrate is a silicon substrate.

[0019] Optionally, the method further includes: a circuit board, wherein the circuit board is located at a side of the driver chip away from the laser chip, and the circuit board is electrically connected to the driver chip.

[0020] Optionally, the driver chip and the circuit board are packaged in a ball grid array manner.

[0021] Optionally, the driving chip and the circuit board are electrically connected via solder balls.

[0022] Optionally, it further includes: a capacitor, which is fixed on the circuit board, and the laser chip is electrically connected to the capacitor.

[0023] Accordingly, the present invention further provides a laser radar, comprising:

[0024] A planar array laser emission module, the planar array laser emission module comprises: a driver chip, the driver chip comprises a driver circuit; a laser chip, the laser chip is stacked on the surface of the driver chip, the laser chip comprises: a laser substrate; a plurality of laser units, the laser units are located on a side of the laser substrate away from the driver chip; a connecting column, the connecting column passes through the laser substrate to achieve electrical connection between the laser units and the driver circuit; the planar array laser emission module is suitable for emitting detection light; the emitted detection light is reflected to form echo light; a planar array laser receiving module, the planar array laser receiving module is suitable for receiving the echo light.

[0025] Optionally, the planar array laser receiving module includes a detection unit, and the detection unit includes at least one of a single photon avalanche diode, a silicon photomultiplier tube and an avalanche photodiode.

[0026] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0027] In the technical solution of the present invention, the laser chip has a connecting column, and the connecting column penetrates the laser substrate to realize the electrical connection between the laser unit and the driving circuit. The electrical connection between the laser unit and the driving circuit is realized through the connecting column, which can effectively shorten the wiring length, increase the wiring width and significantly reduce the parasitic resistance of the loop. Moreover, the wiring length is greatly shortened, which can effectively reduce the loop area and loop inductance, and can effectively reduce the pulse width of the emitted laser, which is conducive to ensuring the distance measurement capability of the laser radar.

[0028] In an optional solution of the present invention, the laser chip has one upper bus, and the upper bus is connected to the second electrodes of all laser units. With one upper bus connected to the second electrodes of all laser units, the upper bus has a larger area and thickness, and is laid flat on all laser units, which can not only further reduce parasitic inductance and parasitic resistance, but also effectively ensure the uniformity of light emission of laser units at different positions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work. The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0030] Figure 1 It is a schematic diagram of the structure of a Flash laser radar;

[0031] Figure 2 It is a schematic diagram of the side view structure of a two-dimensionally addressed area array laser;

[0032] Figure 3 yes Figure 2 A schematic diagram of the top view structure of the area array laser shown;

[0033] Figure 4 It is a schematic diagram of the side view structure of another two-dimensionally addressed area array laser;

[0034] Figure 5 yes Figure 4 A schematic diagram of the top view structure of the area array laser shown;

[0035] Figure 6 It is a schematic diagram of the structure of a laser chip in a two-dimensionally addressed area array laser;

[0036] Figure 7 yes Figure 6 A circuit diagram of the laser chip shown;

[0037] Figure 8 It is a schematic cross-sectional structure diagram of an embodiment of a planar array laser emission module of the present invention;

[0038] Fig. 9 yes Figure 8 The schematic diagram of the planar array laser emission module embodiment is a top view along arrow A;

[0039] Fig.10 yes Figure 8 A schematic diagram of the circuit structure of an embodiment of the planar array laser emission module shown;

[0040] Fig.11 It is a schematic diagram of the circuit structure of another embodiment of the planar array laser emission module of the present invention;

[0041] Fig.12 It is a circuit structure diagram of another embodiment of the planar array laser emission module of the present invention;

[0042] Fig.13 It is a functional block diagram of an embodiment of the laser radar of the present invention. DETAILED DESCRIPTION

[0043] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0047] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0048] Figure 1 The schematic diagram of the structure of a Flash laser radar is shown. Among them, the transmitting end of the laser radar is a planar array laser, and the receiving end is a planar array detector. In the early Flash laser radar, the entire planar array laser is turned on to illuminate the entire field of view during one scan, and all detectors at the receiving end work simultaneously; later, a continuously emitting Flash laser radar was developed, and its working mode is generally that one column (row) or multiple columns (rows) of lasers emit light at the same time, and correspondingly, the echo signal is received at the receiving end in columns (rows) or multiple columns (rows), and then the whole frame image is formed by working column (row) by column (row). The continuously emitting Flash laser radar can perform one-dimensional addressing and control a column or multiple columns of lasers at the same time.

[0049] However, both of the above methods require measuring multiple detection channels in parallel, which leads to serious crosstalk problems between channels of the laser radar. Therefore, it is expected to perform two-dimensional addressing on the array laser to reduce the number of lasers emitting in parallel, or to make the lasers emitting in parallel spaced farther apart, thereby reducing crosstalk between channels.

[0050] However, the use of two-dimensionally addressed array lasers is often prone to large parasitic inductance and parasitic resistance, which leads to degradation of lidar performance. This article analyzes the causes of the large parasitic capacitance and parasitic inductance problems of a two-dimensionally addressed array laser:

[0051] refer to Figures 2 to 4 ,in Figure 2 It is a schematic diagram of the side view structure of a two-dimensionally addressed area array laser; Figure 3 yes Figure 2 A schematic diagram of the top view structure of the area array laser shown; Figure 4 It is a schematic diagram of the side view structure of another two-dimensionally addressed area array laser; Figure 5 yes Figure 4 Schematic diagram of the top view structure of the area array laser shown.

[0052] Figure 2 and Figure 3 In the area array laser shown, the driver chip 22 and the laser chip 23 are sequentially stacked on the surface of the circuit board 21; Figure 4 and Figure 5 In the area array laser shown, the driver chip 32 and the laser chip 33 are laid flat on the surface of the circuit board 31. However, whether stacked or laid flat, the laser chip, the driver chip and the circuit board are electrically connected through conductive wires formed by a wire bonding process.

[0053] Combined with reference Figure 6 and Figure 7 ,in Figure 6 It is a schematic diagram of the structure of a laser chip in a two-dimensionally addressed area array laser; Figure 7 yes Figure 6 Circuit diagram of the laser chip shown.

[0054] Figure 6 The 16 laser units in the laser chip are shown. In the laser chip, the 16 laser units are arranged in an array; anode bus A, anode bus B, anode bus C, and anode bus D are arranged in parallel along the row direction; cathode bus 1, cathode bus 2, cathode bus 3, and cathode bus 4 are arranged in parallel along the column direction, and the 16 laser units are respectively connected between the anode bus and the cathode bus.

[0055] The laser chip is driven by two poles, that is, by selecting the corresponding anode bus and cathode bus to enable the corresponding laser unit; for example, by selecting the anode bus D and the cathode bus 3 to enable the laser unit D3.

[0056] For each laser unit, its electrode is often set on the top layer, that is, the surface close to the light-emitting surface of the laser unit, so the laser chip and the driver chip are often electrically connected by forming conductive wires through the wire bonding process. The conductive wires formed by the wire bonding process are thin and long, which can easily increase the parasitic resistance and parasitic inductance in the loop, and easily reduce the luminous power and photoelectric conversion efficiency of the laser unit.

[0057] Moreover, in the laser chip, the anode bus and the cathode bus are both very long, and in order to achieve isolation between the anode bus and the cathode bus, the anode bus and the cathode bus are generally arranged on the upper and lower sides of the laser unit, that is, the anode bus is often located at the top layer of the laser unit, and the cathode bus is often located at the bottom layer of the laser unit. The cathode bus is usually longer and thinner, which will also bring larger parasitic inductance and parasitic resistance, and will also affect the conversion efficiency and luminous power of the laser unit.

[0058] Specifically, when the parasitic resistance in the loop is large, part of the energy in the loop is consumed by the parasitic resistance to generate heat energy, thereby reducing the luminous power of the laser unit. In practical applications, the laser unit farthest from the electrode (such as Figure 6 The laser unit A4 position) is compared with the laser unit closest to the electrode (such as Figure 6 In addition, if the parasitic inductance in the loop is large, the current rise rate in the laser unit will be greatly reduced when the circuit is turned on, thus causing the laser pulse emitted by the laser unit to be widened and the peak power to be reduced, affecting the distance measurement capability of the laser radar.

[0059] In order to solve the technical problem, the present invention provides a planar array laser emission module, comprising: a driving chip, the driving chip comprising a driving circuit; a laser chip, the laser chip is stacked on the surface of the driving chip, and the laser chip comprises: a laser substrate; a plurality of laser units, the laser units are located on a side of the laser substrate away from the driving chip; and a connecting column, the connecting column passes through the laser substrate to achieve electrical connection between the laser unit and the driving circuit.

[0060] In the technical solution of the present invention, the laser chip has a connecting column, and the connecting column penetrates the laser substrate to realize the electrical connection between the laser unit and the driving circuit. The electrical connection between the laser unit and the driving circuit is realized by the connecting column, which can effectively shorten the wiring length, increase the wiring width and significantly reduce the parasitic resistance of the loop. Moreover, the wiring length is greatly shortened, which can effectively increase the loop area and reduce the loop inductance, and can effectively reduce the pulse width of the emitted laser, which is conducive to ensuring the distance measurement capability of the laser radar.

[0061] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0062] refer to Figure 8 , combined with reference Fig. 9 , showing a schematic structural diagram of an embodiment of a planar array laser emission module of the present invention; wherein, Figure 8 is a schematic cross-sectional structure diagram of an embodiment of the planar array laser emission module, Fig. 9 yes Figure 8 The schematic diagram of the structure of the planar array laser emission module embodiment shown is a top view along arrow A.

[0063] The planar array laser emission module includes: a driver chip 110, the driver chip 110 includes a driver circuit 111; a laser chip 120, the laser chip 120 is stacked on the surface of the driver chip 110, and the laser chip 120 includes: a laser substrate 121; a plurality of laser units 122, the laser units 122 are located on a side of the laser substrate 121 away from the driver chip 110; and a connecting column 123, the connecting column 123 passes through the laser substrate 121 to achieve electrical connection between the laser unit 122 and the driver circuit 111.

[0064] The laser unit 122 and the driving circuit 111 are connected by a short and thick connecting column 123, which can effectively shorten the wiring length, increase the wiring width and significantly reduce the parasitic resistance and parasitic inductance of the loop, which is beneficial to improving the conversion efficiency and light-emitting power, and is beneficial to reducing the pulse width of the emitted laser.

[0065] The technical solution of the planar array laser emission module embodiment is described in detail below with reference to the accompanying drawings.

[0066] The driving chip 110 has a driving circuit 111 for driving the laser unit 122 to generate and emit detection light.

[0067] In some embodiments of the present invention, the driver chip 110 is a silicon-based chip, that is, the driver chip 110 includes: a chip substrate 112, and the chip substrate 112 is a silicon substrate.

[0068] like Figure 8 In some specific embodiments shown, there are multiple driving circuits 111 , that is, the driving chip 110 includes multiple driving circuits 111 . Specifically, the multiple driving circuits 111 are distributed in the chip substrate 112 .

[0069] The laser chip 120 is stacked on the surface of the driving chip 110 . The laser chip 120 includes a laser unit 122 for being driven to generate detection light.

[0070] like Figure 8 As shown, the laser chip 120 has a laser substrate 121, and the laser substrate 121 is used to provide mechanical support and a process operation platform.

[0071] The laser chip 120 further includes a plurality of laser units 122. The plurality of laser units 122 are distributed on the surface of the laser substrate 121, such as Fig. 9As shown, a plurality of the laser units 122 are distributed in an array to form a light-emitting array.

[0072] In some specific embodiments, the laser substrate 121 is a gallium arsenide substrate. The material of the laser unit 122 is generally a III-V group material, and the laser substrate 121 is set as a gallium arsenide substrate, so as to provide a good process surface for the formation of the laser unit 122, so as to improve the performance of the laser unit 122.

[0073] In some embodiments of the present invention, the laser unit 122 is a vertical cavity surface emitting laser unit (Vertical Cavity Surface Emitting Laser, VCSEL), and the laser unit 122 emits detection light in a direction perpendicular to the surface of the laser substrate 122 .

[0074] The laser unit 122 emits detection light under the drive of the driving circuit 111. The connecting column 123 of the laser chip 120 is used to connect the laser chip 120 and the driving chip 110.

[0075] like Figure 8 In some specific embodiments shown, the laser unit 122 includes: a first electrode 122a, an active layer 122b and a second electrode 122c, and the first electrode 122a, the active layer 122b and the second electrode 122c are stacked in sequence on the laser substrate 121.

[0076] It can be seen that the first electrode 122a is closer to the laser substrate 121, so one end of the connecting column 123 is electrically connected to the first electrode 122a; the connecting column 123 also penetrates the laser substrate 121, and the other end is exposed from the surface of the laser substrate 121 away from the laser unit 122.

[0077] In some embodiments of the present invention, the aspect ratio of the connecting pillar 123 is less than 1. Specifically, the height of the connecting pillar 123 refers to the size of the connecting pillar 123 in a direction perpendicular to the surface of the laser substrate 121; the width of the connecting pillar 123 refers to the size of the connecting pillar 123 in a plane parallel to the surface of the laser substrate 121.

[0078] It can be seen that the connecting column 123 is short and thick. The short and thick connecting column 123 is used to realize the electrical connection between the laser chip 120 and the driver chip 110, which can greatly shorten the wiring length, greatly increase the wiring width, and significantly reduce the parasitic resistance and parasitic inductance of the loop.

[0079] In some embodiments of the present invention, the material of the connecting column 123 is copper, and of course other conductive metals such as silver can also be used. Specifically, a through hole can be formed in the laser chip 120 by deep reactive ion etching or laser drilling technology; and a conductive material such as copper, silver, etc. can be poured into the through hole to form the connecting column 123.

[0080] Continue to refer Figure 8 In some embodiments, in a plane parallel to the surface of the laser substrate 121, the projection of the active layer 122b is within the range of the projection of the first electrode 122a. Specifically, in a plane parallel to the surface of the laser substrate 121, the area of ​​the active layer 122b is equal to the area of ​​the second electrode 122c and is smaller than the area of ​​the first electrode 122a; in the surface of the laser substrate 121, the projection of the active layer 122b coincides with the projection of the second electrode 122c, and the projection of the active layer 122b is located within the projection of the first electrode 122a.

[0081] In a plane parallel to the surface of the laser substrate 121, the area of ​​the first electrode 122a is larger, larger than the area of ​​the active layer 122b and the area of ​​the second electrode 122c; therefore, in some specific embodiments, the connecting column 123 also penetrates the first electrode 122a and is exposed from the surface of the first electrode 122a away from the laser substrate 121.

[0082] The connecting column 123 passes through the first electrode 122a, and one end of the connecting column 123 is exposed from the surface of the first electrode 122a away from the laser substrate 121. Therefore, the first electrode 122a is in direct contact with the surface of the laser substrate 121, that is, the first electrode 122a can be directly formed on the surface of the laser substrate 121, thereby effectively ensuring the formation quality of the material of the first electrode 122a and the formation quality of the film layer above the first electrode 122a, which is conducive to the formation of a high-quality laser unit.

[0083] In some embodiments of the present invention, the second electrodes 122 c of the plurality of laser units 122 are electrically connected, that is, the second electrodes 122 c of the plurality of laser units 122 are electrically connected and then further connected to an external circuit or other components.

[0084] In some embodiments of the present invention, the laser chip 120 further includes: at least one upper bus 130 , wherein the upper bus 130 is located on a side of the laser unit 122 away from the laser substrate 121 , and each of the upper bus 130 is connected to the second electrodes 122 c of a plurality of the laser units 122 .

[0085] Specific as Figure 8 As shown, the upper bus 130 is located on a side of all the laser units 122 away from the laser substrate 121, and is connected to the second electrodes 122c of the plurality of laser units 122. In some specific embodiments, the laser chip 120 includes one upper bus 130, and the upper bus 130 is connected to the second electrodes 122c of all the laser units 122.

[0086] Specific as Fig. 9 As shown, the laser chip includes an upper bus 130, which connects the second electrodes 122c of all the laser units 122, and the upper bus 130 is laid flat on the surface of all the laser units 122. Since the laser units 122 emit detection light in a direction perpendicular to the surface of the laser substrate 122, in order to ensure the emission of detection light, the upper bus 130 is in a grid shape, and the laser units 122 are located at the mesh position of the upper bus 130, and the upper bus 130 exposes the laser units 122.

[0087] The second electrodes 122c of all the laser units 122 are connected by a flat grid-like upper bus 130. For example, the upper bus 130 can be made of copper or other conductive metals. The upper bus 130 has a larger area and a thicker thickness, and can supply power to the second electrodes 122c of the plurality of laser units 122 from all directions, which can effectively ensure the power supply stability of the laser units 122 at different positions, and is conducive to improving the uniformity and stability of light emission.

[0088] Combined with reference Fig.10 , showing Figure 8 The circuit diagram of the planar array laser emission module embodiment is shown.

[0089] In some embodiments of the present invention, the driver chip 110 has multiple driver circuits 111, and the multiple driver circuits 111 are connected to the multiple laser units 122 in a one-to-one correspondence, so the number of driver circuits 111 in the driver chip 110 is equal to the number of laser units 122 in the laser chip 120.

[0090] By connecting the plurality of driving circuits 111 and the plurality of laser units 122 in a one-to-one correspondence, the laser units 122 can be switched on one by one as required, thereby reducing the number of laser units 122 that emit light simultaneously, or making the laser units 122 that emit light simultaneously farther apart, so as to reduce crosstalk and improve detection accuracy.

[0091] like Fig.10In some embodiments shown, the driver chip 110 has a plurality of driver circuits 111, and the plurality of driver circuits 111 are connected one-to-one with the plurality of laser units 122. Specifically, the first electrodes 122a of the plurality of laser units 122 and the plurality of driver circuits 111 are electrically connected one-to-one with each other through the connecting column 123, and the laser unit 122 corresponding to the driver circuit is controlled to emit detection light by turning on the driver circuit 111, so that the number of laser units 122 that emit light at the same time can be controlled according to demand, or the laser units 122 that are far apart can be controlled to emit light in parallel, thereby reducing the crosstalk problem between laser radar channels.

[0092] Continue to refer Figure 8 In some embodiments of the present invention, the planar array laser emission module further includes: a plurality of lower busses 140, the lower busses 140 being located on a side of the first electrode 122a away from the laser substrate 121, each of the lower busses 140 being connected to the first electrodes 122a of a plurality of laser units 122; the connecting pillars 123 are in contact with the lower busses 140 to achieve electrical connection.

[0093] Specific as Figure 8 and Fig. 9 As shown, the connecting column 123 passes through the laser substrate 121 and the first electrode 122a, and the end close to the driving chip 110 contacts the corresponding pad of the driving chip 111 to achieve electrical connection; the other end away from the driving chip 110 is exposed from the surface of the first electrode 122a away from the laser substrate 121 and contacts the lower bus 140.

[0094] Continue to refer Figure 8 In some embodiments of the present invention, the planar array laser emission module further includes: a circuit board 150, wherein the circuit board 150 is located on a side of the driver chip 110 away from the laser chip 120, and the circuit board 150 is electrically connected to the driver chip 110.

[0095] Specifically, the driver chip 110 and the circuit board 150 are packaged in a ball grid array manner, that is, the driver chip 110 and the circuit board 150 are electrically connected via solder balls 151 .

[0096] like Figure 8 As shown, the planar array laser emission module also has a capacitor 160, and the capacitor 160 is fixed on the circuit board 150. Therefore, after the second electrodes 122c of the plurality of laser units 122 are electrically connected, they are connected to the capacitor 160 through the driving chip 110 and the circuit board.

[0097] It should be noted that, in some specific embodiments, the planar array laser emission module further includes: a capacitor 160, and the laser chip 120 is electrically connected to the capacitor 160. Fig.10 As shown, after the second electrodes 122 c of the plurality of laser units 122 are electrically connected, they are electrically connected to the capacitor 160 through the driving chip 110 and the circuit board 150 .

[0098] It should also be noted that the multiple laser units 121 of the laser chip 120 are connected one-to-one with the multiple driving circuits 111 of the driving chip 110. This connection method is only an example, and in other embodiments of the present invention, other connection methods may be used between the laser chip and the driving chip.

[0099] refer to Fig.11 , showing a circuit diagram of another embodiment of the planar array laser emission module of the present invention.

[0100] The present invention will not repeat the same points as the above embodiments. The difference from the above embodiments is that the laser chip 220 and the driver chip 210 are not connected in a one-to-one correspondence.

[0101] In some embodiments, the laser chip 220 has a plurality of drive groups 221, each of the drive groups 221 includes at least one laser unit 222, and the second electrodes of the laser units 222 in the same drive group 221 are electrically connected. Fig.11 As shown, the driving group 221 includes four laser units 222 , and the second electrodes of the four laser units 222 of the same driving group 221 are electrically connected.

[0102] Specifically, in the planar laser emission module, the laser chip 220 includes multiple upper-layer buses and multiple lower-layer buses. The second electrodes of all the laser units 222 in the same driving group 221 are connected to the same upper-layer bus, and the first electrodes of the laser units 222 in the same driving group 221 are respectively connected to different lower-layer buses. That is to say, the second electrodes of all the laser units 222 in the same driving group 221 are in contact with the same upper-layer bus to achieve electrical connection with each other, and each laser unit 222 in the same driving group 221 is respectively electrically connected to a different lower-layer bus.

[0103] like Fig.11In some specific embodiments shown, the driving chip 210 includes a plurality of first driving circuits 211 and a plurality of second driving circuits 212; a plurality of lower-layer buses are electrically connected to different first driving circuits through connecting columns, and a plurality of upper-layer buses are electrically connected to different second driving circuits through connecting columns. That is, the first electrode of each of the laser units 222 is electrically connected to one of the first driving circuits 211 through the connecting column, and the first electrodes of the laser units 222 of the same driving group 221 are electrically connected to different first driving circuits 211; the second electrode of each of the laser units 222 is electrically connected to one of the second driving circuits 212 through the connecting column, and the second electrode of the laser units 222 of the same driving group 221 is electrically connected to the same second driving circuit 212, and the laser units 222 in different driving groups 221 are connected to different second driving circuits 212.

[0104] The laser emission module using the above method can select the corresponding laser by driving a first drive circuit 211 and a second drive circuit 212, and can also realize two-dimensional selection of the laser module. In addition, this method can reduce the number of drive circuits, reduce costs and manufacturing difficulty.

[0105] It should be noted that the driving chip 210 further includes: a first multiplexer 211MUX and a second multiplexer 212MUX; a plurality of the first driving circuits 211 are all connected to the first multiplexer 211MUX, and a plurality of the second driving circuits 212 are all connected to the second multiplexer 212MUX.

[0106] It should also be noted that the second electrode of at least one of the laser units 222 of the same driving group 221 is electrically connected to the same second driving circuit 212. Therefore, in some specific embodiments, the second electrodes of multiple laser units in the same driving group are electrically connected and then further connected to an external circuit or other components. For example, the second electrodes of multiple laser units in the same driving group are electrically connected and then connected to a capacitor.

[0107] In addition, in the aforementioned embodiment, the driver chip 210 includes a plurality of first driver circuits 211 and a plurality of second driver circuits 212, and the first electrodes and the second electrodes of the laser units in different driver groups 221 are respectively connected to different first driver circuits 211 and second driver circuits 212. However, this arrangement is only an example, and in other embodiments of the present invention, the driver circuits in the driver chip and the laser units in the laser chip may also be connected in other ways.

[0108] refer to Fig.12 , showing a circuit diagram of another embodiment of the planar array laser emission module of the present invention.

[0109] The present invention will not repeat the same points as the above-mentioned embodiments. The difference from the above-mentioned embodiments is that the driving chip 310 includes a plurality of driving circuits 311; in the laser chip 320, one electrode of the laser units 322 of all driving groups 321 are connected, and the other electrode of the laser units 322 of the same driving group 321 is connected to the same driving circuit 311, that is, the other electrode of the laser units 322 of different driving groups 321 is connected to different driving circuits 311. Fig.12 As shown, the cathodes of the laser units 322 of the same driving group 321 are connected to the same driving circuit 311, and the anodes of the laser units 322 of all driving groups 321 are connected to the capacitor. It should be noted that the number of laser units 322 in different driving groups 321 can be the same or different.

[0110] Specifically, the laser chip includes: an upper bus and multiple lower buses; the second electrodes of all the laser units 322 are connected via the upper bus; the first electrodes of the laser units 322 of the same driving group 321 are connected via a lower bus, and are connected to the same driving circuit 311.

[0111] The laser units 322 of the same driving group 321 are connected to the same driving circuit 311, so that by selecting one driving circuit 311, the laser units 322 connected thereto can be controlled to emit light at the same time, so as to reduce the number of driving circuits 311 and reduce the complexity of the driving chip 310; in addition, the simultaneous emission of multiple laser units 322 is also conducive to improving the laser radar scanning rate and the frame rate. Furthermore, in order to reduce the crosstalk problem caused by the simultaneous emission of laser units 322, the number of laser units connected to the same driving circuit 311 can be reduced, and laser units 322 that are physically far apart can also be connected to the same driving circuit.

[0112] Correspondingly, the present invention also provides a laser radar.

[0113] refer to Fig.13 , shows a functional block diagram of an embodiment of the laser radar of the present invention.

[0114] The laser radar comprises: a planar array laser emitting module 301 and a planar array laser receiving module 303 .

[0115] Combined with reference Figures 8 to 10 , showing Fig.13 The schematic diagram of the structure of the planar array laser emission module in the laser radar embodiment shown in FIG. Figure 8 is a schematic cross-sectional structure diagram of a planar array laser emission module in the laser radar embodiment, Fig. 9 yes Figure 8A schematic diagram of the top view of the planar array laser emission module along arrow A in the laser radar embodiment shown; Fig.10 yes Figure 8 Schematic diagram of the circuit structure of the area array laser emission module in the laser radar embodiment shown.

[0116] The planar array laser emission module 301 includes: the planar array laser emission module includes: a driving chip 110, the driving chip 110 includes a driving circuit 111; a laser chip 120, the laser chip 120 is stacked on the surface of the driving chip 110, and the laser chip 120 includes: a laser substrate 121; a plurality of laser units 122, the laser units 122 are located on the side of the laser substrate 121 away from the driving chip 110; a connecting column 123, the connecting column 123 passes through the laser substrate 121 to achieve electrical connection between the laser unit 122 and the driving circuit 111; the planar array laser emission module is suitable for emitting detection light.

[0117] In some embodiments, the planar array laser emission module 301 is the planar array laser emission module of the present invention. Specifically, the specific technical solution of the planar array laser emission module 301 refers to the embodiment of the planar array laser emission module, and the present invention will not repeat it here.

[0118] The detection light emitted by the planar array laser emission module 301 is reflected by the target 302 to form echo light. The planar array laser receiving module 303 is suitable for receiving the echo light to achieve detection.

[0119] In some embodiments of the present invention, the planar laser receiving module 303 includes a detection unit, and the detection unit includes at least one of a single photon avalanche diode (SPAD), a silicon photomultiplier (SiPM) and an avalanche photodiode (APD).

[0120] Specifically, the detection unit of the planar array laser receiving module 303 has a corresponding relationship with the laser unit of the planar array laser emitting module 301. In some specific embodiments, the laser unit and the detection unit can be one-to-one, one-to-many, many-to-one, many-to-many, etc. Since each laser in the planar array laser can be individually addressed and gated, the multiple laser units in the planar array laser emitting module 301 emit light in time (in sequence or partially at the same time) to reduce crosstalk between channels.

[0121] In summary, the laser chip has a connecting column, and the connecting column penetrates the laser substrate to realize the electrical connection between the laser unit and the driving circuit. The electrical connection between the laser unit and the driving circuit is realized through the connecting column, which can effectively shorten the wiring length, increase the wiring width and significantly reduce the parasitic resistance of the loop. Moreover, the wiring length is greatly shortened, which can effectively reduce the loop area and loop inductance, and can effectively reduce the pulse width of the emitted laser, which is conducive to ensuring the distance measurement capability of the laser radar.

[0122] Moreover, the laser chip has one upper bus, and the upper bus is connected to the second electrodes of all laser units. With one upper bus connected to the second electrodes of all laser units, the upper bus has a larger area and thickness, and is laid flat on all laser units, which can not only further reduce parasitic inductance and parasitic resistance, but also effectively ensure the light emission uniformity of laser units at different positions.

[0123] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A planar array laser emission module, characterized in that: include: A driving chip, wherein the driving chip includes a driving circuit; A laser chip, wherein the laser chip is stacked on the surface of the driving chip, and the laser chip comprises: a laser substrate; a plurality of laser units, wherein the laser units are located on a side of the laser substrate away from the driving chip; and a connecting column, wherein the connecting column penetrates the laser substrate to realize electrical connection between the laser units and the driving circuit.

2. The planar array laser emission module according to claim 1, characterized in that: The aspect ratio of the connecting column is less than 1.

3. The planar array laser emission module according to claim 1, characterized in that: The connecting column is made of copper.

4. The planar array laser emission module according to claim 1, characterized in that: The laser substrate is a gallium arsenide substrate.

5. The planar array laser emission module according to claim 1, characterized in that: The laser unit comprises: a first electrode, an active layer and a second electrode, wherein the first electrode, the active layer and the second electrode are sequentially stacked on the laser substrate; One end of the connection column is electrically connected to the first electrode, and the other end is exposed from a surface of the laser substrate away from the laser unit.

6. The planar array laser emission module according to claim 5, characterized in that: In a plane parallel to the surface of the laser substrate, the projection of the active layer is within the range of the projection of the first electrode; The connection column also penetrates the first electrode and is exposed from a surface of the first electrode away from the laser substrate.

7. The planar array laser emission module according to claim 5, characterized in that: The second electrodes of the plurality of laser units are electrically connected.

8. The planar array laser emission module according to claim 7, characterized in that: The laser chip further comprises: at least one upper bus, the upper bus is located at a side of the laser unit away from the laser substrate, and each of the upper bus is connected to the second electrodes of a plurality of the laser units.

9. The planar array laser emission module according to claim 8, characterized in that: The laser chip includes one upper bus, and the upper bus is connected to the second electrodes of all the laser units.

10. The planar array laser emission module according to claim 8, characterized in that: The driving chip includes a plurality of driving circuits; The first electrodes of the plurality of laser units and the plurality of driving circuits are electrically connected in a one-to-one correspondence via the connecting pillars.

11. The planar array laser emission module according to claim 8, characterized in that: The driving chip further includes: a plurality of lower bus lines, wherein the lower bus lines are located on a side of the first electrode away from the laser substrate, and each of the lower bus lines is connected to the first electrodes of a plurality of the laser units.

12. The planar array laser emission module according to claim 11, characterized in that: The laser chip has a plurality of driving groups, each of which includes at least one laser unit, and the second electrodes of the laser units in the same driving group are electrically connected.

13. The planar array laser emission module according to claim 12, characterized in that: The laser chip comprises a plurality of upper bus lines, and the second electrodes of all the laser units in the same driving group are connected to the same upper bus line; Furthermore, the first electrodes of the laser units in the same driving group are respectively connected to different lower-layer buses.

14. The planar array laser emission module according to claim 13, characterized in that: The driving chip includes a plurality of first driving circuits and a plurality of second driving circuits; The plurality of lower-layer bus lines are electrically connected to different first drive circuits through the connection pillars; and the plurality of upper-layer bus lines are electrically connected to different second drive circuits through the connection pillars.

15. The planar array laser emission module according to claim 1, characterized in that: The driving chip comprises: a chip substrate, and the chip substrate is a silicon substrate.

16. The planar array laser emission module according to claim 1, characterized in that: Also includes: A circuit board is located at a side of the driving chip away from the laser chip, and the circuit board is electrically connected to the driving chip.

17. The planar array laser emission module according to claim 16, characterized in that: The driving chip and the circuit board are packaged in a ball grid array manner.

18. The planar array laser emission module according to claim 16 or 17, characterized in that: The driving chip and the circuit board are electrically connected via solder balls.

19. The planar array laser emission module according to claim 16, characterized in that: Also includes: A capacitor is fixed on the circuit board, and an electrical connection is achieved between the laser chip and the capacitor.

20. A laser radar, characterized in that: A planar array laser emission module, the planar array laser emission module comprising: a driver chip, the driver chip comprising a driver circuit; a laser chip, the laser chip being stacked on the surface of the driver chip, the laser chip comprising: a laser substrate; a plurality of laser units, the laser units being located on a side of the laser substrate away from the driver chip; a connecting column, the connecting column penetrating the laser substrate to realize electrical connection between the laser units and the driver circuit; the planar array laser emission module is suitable for emitting detection light; The outgoing detection light is reflected to form echo light; A planar array laser receiving module, wherein the planar array laser receiving module is suitable for receiving the echo light.

21. The laser radar according to claim 20, characterized in that The planar array laser receiving module comprises a detection unit, and the detection unit comprises at least one of a single photon avalanche diode, a silicon photomultiplier tube and an avalanche photodiode.

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