A transmitting package module, a transmitting module, and a lidar

Abstract

The present application provides a transmitting package module, a transmitting module, and a lidar. The transmitting package module includes a substrate and a light-transmissive cover plate covering the substrate, and an airtight space is formed between the substrate and the light-transmissive cover plate. Inside the airtight space, at least two groups of vertical cavity surface emitting lasers, a driving module, and at least one capacitor are fixed on the substrate. The at least one capacitor includes an energy storage capacitor for storing energy, and the driving module is configured to drive at least part of the at least two groups of vertical cavity surface emitting lasers to emit light beams through the energy in the energy storage capacitor. The present application can reduce the difficulty of packaging multiple VCSELs onto a circuit board and improve reliability.

Description

Technical Field

[0001] The present application relates to the field of circuits, and particularly to a transmitting package module, a transmitting module, and a lidar. Background Art

[0002] A vertical-cavity surface-emitting laser (VCSEL) is a semiconductor whose laser is emitted perpendicular to the top surface, and it plays an important role in fields such as laser ranging and space laser communication. The traditional packaging method or assembly method of VCSEL is to directly use a COB (Chips on Board) process assembly solution on a printed circuit board (PCB) of a product. Among them, the COB process refers to a process of adhering bare chips to an interconnection substrate with conductive or non-conductive adhesive. However, the COB process generally requires more wire bonding. For a transmitting module with a large number of VCSELs, it is necessary to densely bond pads. It is very difficult to achieve a dense pitch of about 50um in the manufacturing process. At the same time, too many wire bondings also reduce the overall manufacturing efficiency. Moreover, once a defective VCSEL appears, it will cause the PCB board of the entire product to be scrapped. Summary of the Invention

[0003] The present application provides a transmitting package module, a transmitting module, and a lidar, which can reduce the difficulty of packaging multiple VCSELs onto a circuit board and improve reliability.

[0004] In a first aspect, the present application provides a transmitting package module, including:

[0005] A substrate, and a light-passing cover plate covering the substrate, and an airtight space is formed between the substrate and the light-passing cover plate;

[0006] In the airtight space, at least two groups of vertical-cavity surface-emitting lasers, a driving module, and at least one capacitor are fixed on the substrate,

[0007] wherein each group of vertical-cavity surface-emitting lasers includes at least one vertical-cavity surface-emitting laser;

[0008] wherein the at least one capacitor includes an energy storage capacitor for storing energy, and the driving module is used to drive at least part of the at least two groups of vertical-cavity surface-emitting lasers to emit light beams through the energy in the energy storage capacitor.

[0009] Optionally, the driving module includes at least a first high-side driving chip and at least a first low-side driving chip.

[0010] Optionally, the first high-side driving chip and the first low-side driving chip drive at least one selected group of the at least two groups of vertical cavity surface emitting lasers to emit light by selecting at least one group of the at least two groups of vertical cavity surface emitting lasers.

[0011] Optionally, the at least two groups of vertical cavity surface emitting lasers are a vertical cavity surface emitting laser array;

[0012] The driving module further includes a second high-side driving chip. The first high-side driving chip and the second high-side driving chip are respectively located on opposite sides of the vertical cavity surface emitting laser array, and are respectively used to drive different groups of vertical cavity surface emitting lasers in the vertical cavity surface emitting laser array.

[0013] Optionally, the at least two groups of vertical cavity surface emitting lasers are a vertical cavity surface emitting laser array;

[0014] The driving module further includes a second low-side driving chip. The first low-side driving chip and the second low-side driving chip are respectively located on opposite sides of the vertical cavity surface emitting laser array, and are respectively used to drive different groups of vertical cavity surface emitting lasers in the vertical cavity surface emitting laser array.

[0015] Optionally, the at least one capacitor further includes at least one bootstrap capacitor for turning on or maintaining the driving state of the first high-side driving chip;

[0016] and / or,

[0017] The at least one capacitor further includes at least one decoupling capacitor corresponding to the first high-side driving chip and / or the first low-side driving chip. The first high-side driving chip and / or the first low-side driving chip are connected to the ground through the corresponding decoupling capacitor.

[0018] Optionally, the pins of the first high-side driving chip and / or the first low-side driving chip are arranged adjacent to the corresponding decoupling capacitor.

[0019] Optionally, the energy storage capacitor is arranged adjacent to the at least two groups of vertical cavity surface emitting lasers.

[0020] Optionally, the at least two groups of vertical cavity surface emitting lasers are mounted on the substrate by a COB process and are wire-bonded to the pads on the substrate.

[0021] Optionally, the driving module is pre-packaged in a ball grid array package form by a chip-level packaging process.

[0022] Optionally, the driving module is mounted on the substrate by a COB process and is wire-bonded to the pads on the substrate; or,

[0023] The driving module is mounted on the substrate by flip chip technology.

[0024] Optionally, the at least one capacitor is mounted on the substrate by surface mount technology.

[0025] Optionally, the light transmissive cover plate includes a cover plate area and a light window area located on the outgoing light path of the at least two groups of vertical cavity surface emitting lasers.

[0026] Optionally, the coefficient of thermal expansion of the cover plate area is within [12×10 -6 / deg, 15×10 -6 / deg], and the coefficient of thermal expansion of the substrate is within [10×10 -6 / deg, 12×10 -6 / deg].

[0027] Optionally, the cover plate area is mounted on the substrate by a first mounting glue and is mounted on the light window area by a second mounting glue.

[0028] Optionally, the first mounting glue is a one-component thermosetting epoxy resin, and the second mounting glue is a one-component thermosetting silicone rubber.

[0029] Optionally, the hermetic space is filled with an inert gas.

[0030] Optionally, the substrate is a BT resin-based copper clad laminate; and / or,

[0031] The area of the substrate in contact with the at least two groups of vertical cavity surface emitting lasers is filled with metal.

[0032] In a second aspect, the present application discloses a transmitting module, including the transmitting encapsulation module described in any one of the above and a circuit board; a power supply and an energizing circuit are further provided on the circuit board; the circuit board is electrically connected to the transmitting encapsulation module.

[0033] In a third aspect, the present application provides a lidar, characterized by including the transmitting encapsulation module described in any one of the above.

[0034] Optionally, the lidar is a solid-state lidar.

[0035] In the embodiments of the present application, at least two groups of VCSELs, their driving modules, and energy storage capacitors in the emission module are locally packaged and integrated into an emission packaging module, and the packaged emission packaging module can be mounted on a circuit board during assembly; compared with directly mounting multiple VCSELs, their driving modules, and energy storage capacitors on the circuit board in the prior art, once a scrapped VCSEL appears, the entire circuit board of the product will be scrapped. The embodiments of the present application can better perform preliminary screening on the emission packaging module, achieving a relatively high yield control. The embodiments of the present application can also reduce the process difficulty. In existing products, high-precision alignment and fitting of each VCSEL on the circuit board are often required. In the present application, by pre-packaging to form an emission packaging module, the difficulty of packaging each VCSEL onto the circuit board can be reduced; in addition, each VCSEL, its energy storage capacitor, and driving module are packaged in the emission packaging module, which can reduce the parasitic parameters in the control driving circuit; moreover, by integrating and overall packaging the key device modules in the emission module, this form can ensure the consistency and stability of the multi-channel emission device, and the airtight packaging structure ensures a stable internal environment, thereby improving the reliability of the core power device and the driving device, and enhancing the reliability of the overall emission module. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of an embodiment of the emission packaging module of the present application;

[0037] Figure 2 is a schematic diagram of the logical structure of an embodiment of the emission module of the present application;

[0038] Figure 3 is a schematic diagram of a partial topological structure of an embodiment of the emission module of the present application;

[0039] Figure 4 is a schematic diagram of a partial topological structure of another embodiment of the emission module of the present application;

[0040] Figure 5 is a schematic diagram of an embodiment of the arrangement of at least some components in the emission packaging module of the present application;

[0041] Figure 6 is a schematic diagram of an embodiment of the arrangement of at least some components in the emission packaging module of the present application;

[0042] Figure 7 is a schematic diagram of an embodiment of the lidar of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0044] The terms used in the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "the" and "said" used in the present application and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0045] It should be understood that although the terms "first", "second", "third", etc. may be used in the present application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0046] As Figure 1 shown, Figure 1 is a schematic diagram of an embodiment of the emission packaging module of the present application. The emission packaging module 100 includes a substrate 101 and a light-transmissive cover plate 102 covering the substrate 101, and an airtight space is formed between the substrate 101 and the light-transmissive cover plate 102. Optionally, an inert gas is further filled in the airtight space. In the airtight space, at least two groups of VCSELs 103, a driving module 104 and at least one capacitor are fixed on the substrate 101. Each group of vertical cavity surface emitting lasers includes at least one vertical cavity surface emitting laser. Wherein, the at least one capacitor 105 includes an energy storage capacitor for storing energy, and the driving module 104 is used to drive at least part of the at least two groups of VCSELs to emit light beams through the energy in the energy storage capacitor.

[0047] Optionally, the driving module 104 can choose to drive different groups of VCSELs to emit light beams at different times. Each VCSEL in the same group of VCSELs can be in a series relationship or a parallel relationship and needs to emit light beams simultaneously under the drive of the driving module 104. In one example, the driving module 104 includes a plurality of driving switches, and the conduction and disconnection of different driving switches are selected through the setting of pulse signals to control different groups of vertical cavity surface emitting lasers to emit light beams at different times. Optionally, the driving module 104 can also select different groups of VCSELs to emit light at the same time through the setting of pulse signals to increase the emission power.

[0048] Optionally, the driving module includes at least a first high-side driving chip and at least a first low-side driving chip. The first high-side driving chip and the first low-side driving chip drive at least one group of the at least two groups of VCSELs to emit light by gating. In the prior art, single-sided driving is generally used to drive a family of vertical cavity surface emitting lasers to emit light. In this application, double-sided driving is adopted, that is, a group of VCSELs can emit light only when driven by a high-side driving chip and a low-side driving chip. This can improve the flexibility of control and facilitate the selection of VCSELs to be driven to emit light among at least two groups of VCSELs when integrated driving is adopted. Of course, the driving module in this application can also only include a high-side driving chip or only include a low-side driving chip, which is not limited here.

[0049] There are various connection methods for the VCSEL, the driving module, and the capacitor in the emission packaging module. The following Figure 2 takes one of them as an example for description. As Figure 2 shown, Figure 2 is a schematic logical structure diagram of an embodiment of the emission module of this application. The emission module includes a circuit board 21, and a power supply 22 and an energizing circuit 23 arranged on the circuit board 21. The emission packaging module 22 can be arranged on the circuit board 21 or on another circuit board 25. Figure 2The emission packaging module 22 is shown schematically disposed on the circuit board 25. The emission packaging module 24 is electrically connected to the charging circuit 22. The power supply 22 is used to charge energy into the charging circuit 23. Optionally, the emission packaging module 24 includes an energy conversion circuit 241 and an energy release circuit 242. The energy in the charging circuit 23 is transferred to the energy conversion circuit 241, and then transferred from the energy conversion circuit 241 to the energy release circuit 242, so that at least one group of VCSELs emits light beams. Optionally, the driving module includes a high-side driving chip located in the energy conversion circuit 241 and a low-side driving chip located in the energy release circuit 242. The energy conversion circuit 241 further includes an energy storage capacitor in the emission packaging module 22, and the energy release circuit 242 further includes at least one group of VCSELs in the emission packaging module 22. The high-side driving chip in the energy conversion circuit 241 is used to transfer the energy in the charging circuit 23 to the energy storage capacitor, and the low-side driving chip in the energy release circuit 242 is used to drive the energy stored in the energy storage capacitor to be released to at least one group of VCSELs for emission.

[0050] Among them, there are various implementation manners for the energy conversion circuit and the energy release circuit in the emission module. The following combines Figure 3 to give an example description of one of them. As Figure 3 shown, Figure 3 is a partial topological structure schematic diagram of an embodiment of the emission module of the present application. Figure 3 Taking the example that each group of VCSELs only includes one VCSEL for illustration. In the Figure 3 topological structure, the module 301 includes a power supply VCC and a charging circuit, where the charging circuit includes an inductor L1 and a driving switch Q1. The module 302 is an energy conversion circuit, including an energy storage capacitor C1, a diode switch, and at least a part of a high-side driving chip (i.e., a driving switch Q2). The module 303 is an energy release circuit, including at least one group of VCSELs and at least a part of a low-side driving chip (i.e., a driving switch Q3). Among them, the driving switch element can be GaN (Gallium nitride), MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), or IGBT (Insulated Gate Bipolar Transistor), etc. The type of the driving switch element in the present application is not uniquely limited. In this embodiment, the driving switch is taken as an MOS transistor switch for illustration.

[0051] Among them, one end of the power supply VCC is connected to one end of the inductor L1, and the other end of the inductor L1 is respectively connected to the source electrodes of the driving switch Q1 and the driving switch Q2; the gate of the driving switch Q1 is used to receive the first pulse control signal, and the drain is grounded; the gate of the driving switch Q2 is used to receive the second pulse control signal, and the drain is connected to the anode of the diode switch D1; the cathode of the diode switch D1 is respectively connected to the positive plate of the energy storage capacitor C2 and the positive electrode of the VCSEL 31; the cathode of the VCSEL 31 is connected to one pole of the driving switch Q3, the negative plate of the energy storage capacitor C2 is grounded, and the other two poles of the driving switch Q3, the drain is grounded, and the gate is used to receive the third pulse control signal.

[0052] Figure 3 The working mode of the shown circuit topology has multiple types. In one example, the VCSEL 31 emits pulsed light periodically. Before the VCSEL emits pulsed light in each period, the driving switches Q2 and Q3 are in the off state, and the first pulse control signal is used to turn on the driving switch Q1, so that the charging circuit of the power supply VCC - inductor L1 - driving switch Q1 is turned on, and the power supply VCC charges the inductor L1. After the inductor L1 is fully charged, the first pulse control signal is used to turn off the triode switch Q1, and the second pulse control signal is used to turn on the driving switch Q2, so that the energy conversion circuit of the inductor L1 - driving switch Q2 - diode switch D1 - energy storage capacitor C1 is turned on, and then the energy of the inductor L1 is stored in the energy storage capacitor C1 in the emission package module. After the storage is completed, the driving switch Q2 is turned off, and the third pulse control signal is used to turn on the driving switch Q3, so that the energy release circuit of the energy storage capacitor C1 - VCSEL31 - driving switch Q3 is turned on, and then the energy in the energy storage capacitor C1 is released to the VCSEL 31, so that the VCSEL 31 emits a laser beam.

[0053] In some examples, the driving module in the emission package module 22 includes x anode driving modules and y cathode driving modules. The emission package module 22 includes p energy storage capacitors and n groups of VCSELs. The x anode driving modules correspond to the p energy storage capacitors, where p is a positive integer greater than or equal to 1 and less than or equal to n, x is a positive integer less than or equal to p. Each anode driving module corresponds to at least one energy storage capacitor, and the energy storage capacitors corresponding to each anode driving module are different; the y cathode driving modules correspond to n groups of VCSELs, where each cathode driving module corresponds to at least one group of VCSELs, and different groups of VCSELs corresponding to each cathode driving module; where n is a positive integer greater than 1, and y is a positive integer less than or equal to n. Each anode driving module may include Figure 3 the driving switch Q2 and / or the diode switch D1 as shown, and each cathode driving module may include Figure 3The driving switch Q3 shown. Each high-side driving chip includes at least some of the x anode driving modules, and each low-side driving chip includes at least some of the y cathode drivings. For example, in an example where only one high-side driving chip and one low-side driving chip are provided in the emission package module 22, the high-side driving chip includes the x anode driving modules, and the low-side driving chip includes the y cathode driving modules. Another example is that in an example where two high-side driving chips and two low-side driving chips are provided in the emission package module 22, one of the two high-side driving chips includes a part of the x anode driving modules, and the other includes the remaining part of the x anode driving modules; one of the two low-side driving chips includes a part of the y cathode driving modules, and the other includes the remaining part of the y cathode driving modules.

[0054] Among them, the n groups of VCSELs can be used to emit light beams at the same time, or the emission times are staggered, and the light beams are emitted in n times in sequence. Before each group of VCSELs in the n groups of VCSELs emits a light beam, the anode driving module corresponding to the group of VCSELs that emits the light beam is used to transfer the energy in the charging circuit to the corresponding energy storage capacitor, and the corresponding cathode driving module is used to release the energy in the corresponding energy storage capacitor to the group of VCSELs, so that the group of VCSELs emits a light beam. Optionally, the emission module may further include m power supplies and q charging circuits (where m ≤ q, and m is an integer greater than or equal to 1), which respectively correspond to the p energy storage capacitors in the emission package module, and the p energy storage capacitors correspond to the n groups of VCSELs. When m is less than q, in at least some of the power supplies, each power supply corresponds to no less than 2 charging circuits. When q is less than p, in at least some of the charging circuits, each charging circuit corresponds to no less than 2 energy storage capacitors. When p is less than n, in at least some of the energy storage capacitors, each energy storage capacitor corresponds to no less than 2 groups of VCSELs. At least before a group of VCSELs emits a light beam, the power supply corresponding to the group of VCSELs is used to charge energy into the corresponding charging circuit, and the corresponding energy transfer circuit is used to transfer the energy in the corresponding charging circuit to the energy storage capacitor corresponding to the group of VCSELs before the group of VCSELs emits a light beam.

[0055] It can be understood that the voltage values of the m power supplies may be equal or unequal. This application does not limit the voltage values of the m power supplies. As an alternative embodiment, it can be understood that the m groups of power supplies can also drive different numbers of energy conversion circuits. It can be understood that the power supply corresponding to the middle region of the detection field of view can drive fewer groups of energy release circuits, and the power supply corresponding to the edge region of the detection field of view can drive more groups of potential energy circuits. For example, if the power supply in the middle region drives a groups of energy release circuits and the power supply in the edge region drives b groups of energy release circuits, then a ≤ b. It can be understood that by controlling the voltage values of the m power supplies and the number of energy release circuits in the emission array in the detection field of view corresponding to the m power supplies, the detection requirements can be further matched on the basis of the emission module, and the flexibility of detection can be achieved.

[0056] As Figure 3 shown, in Figure 3 the topology shown, one group of VCSELs is taken as one emission channel, Figure 3 which schematically shows a 4*4 group of VCSEL arrays, where each group of VCSELs is specifically 1 VCSEL. Figure 3 only shows the circuit loop corresponding to one group of VCSELs 31 therein: a power supply, a charging circuit, and an emission packaging module. Optionally, the circuit loops of the remaining groups of VCSELs except the first group of VCSELs 31 in the 4*4 group of VCSEL arrays can be as shown in the circuit loop of the first group of VCSELs 31. For simplicity Figure 3 , in Figure 3 they are not shown.

[0057] Optionally, the at least two groups of VCSELs in the embodiments of the present application are specifically a VCSEL array arranged in a rectangular array, and each group of VCSELs is an element in the VCSEL array; the first high-side driving chip is used to drive at least one selected row of elements in the VCSEL array; the first low-side driving chip is used to drive at least one selected column of elements in the VCSEL array. Only a group of VCSELs that is simultaneously located in a row selected by the first high-side driving chip and a column selected by the first low-side driving chip will be successfully driven to emit light beams. In this way, by selecting the rows and columns to select the VCSELs to be driven, the flexibility of control can be improved. Of course, the at least two groups of VCSELs in the embodiments of the present application may also be arranged in an array of other shapes, such as a circular array, an elliptical array, etc. When the driving module drives different groups of VCSELs, it may also be discrete driving, which is not limited herein. It can be understood that one group of VCSELs includes at least one VCSEL emitter. Optionally, one group of VCSELs may also include multiple VCSEL emitters, such as 2, 3, 8, 9. The present application does not limit the number of VCSEL emitters included in one group of VCSELs.

[0058] In the embodiment of the present application, at least two groups of VCSELs in the emission module, their driving modules, and energy storage capacitors are locally encapsulated and systematized into an emission encapsulation module, and the encapsulated emission encapsulation module can be mounted on a circuit board during assembly; compared with directly mounting multiple VCSELs, their driving modules, and energy storage capacitors on the circuit board in the prior art, once a defective VCSEL appears, the entire product's circuit board will be scrapped. The embodiment of the present application can better perform preliminary screening on the emission encapsulation module to achieve a higher yield control. The embodiment of the present application can also reduce the process difficulty. In existing products, high-precision alignment and fitting of each VCSEL on the circuit board are often required. In the present application, by pre-encapsulating to form an emission encapsulation module, the difficulty of encapsulating each VCSEL onto the circuit board can be reduced. In addition, each VCSEL, its energy storage capacitor, and driving module are encapsulated in the emission encapsulation module, which can reduce the parasitic parameters in the control driving circuit. Moreover, by integrating and overall encapsulating the key device modules in the emission module, this form can ensure the consistency and stability of multi-channel emission devices, and the hermetically sealed structure ensures a stable internal environment, thereby improving the reliability of the core power devices and driving devices and enhancing the reliability of the overall emission module. Currently, the reliability requirements for in-vehicle devices are very high. Usually, the devices will be subjected to WHTOL tests, and the test environment is usually a high-temperature and high-humidity environment. For unencapsulated device dies, water molecules or impurities usually penetrate into the device at the edge of the device or at relatively weak positions of the protective layer. After a long time of electromigration effect, it is easy to cause internal conduction or open-circuit failure of the device. In the present application, after local encapsulating the VCSEL, its driving module, and energy storage capacitor into an emission encapsulation module and then fixing it to the circuit board of the emission module, the emission module in the present application is more likely to meet the reliability requirements of in-vehicle devices.

[0059] As Figure 4 shown, Figure 4 is a partial topological structure schematic diagram of another embodiment of the emission module of the present application. The same as the topological structure shown in Figure 3 , the power supply is used to charge energy into the charging circuit, and the energy conversion circuit 401 is used to transfer the energy in the charging circuit to the energy storage capacitor in the emission encapsulation module. The energy conversion circuit 401 includes Figure 3 each component in the energy conversion circuit 302 shown. Different from the topological structure shown in Figure 3 , in the topological structure shown in Figure 4 , the energy conversion circuit 401 further includes driving switches Q4 and Q5, which are used to release the energy stored in the parasitic capacitances of each driving switch in the circuit after the energy storage capacitor C1 transfers the energy to at least one group of VCSELs in the VCSEL array 402.

[0060] Optionally, the emission encapsulation module further includes at least one bootstrap capacitor, which is used to turn on or maintain the driving state of the first high-side driving chip. For example, asFigure 4 As shown, the energy conversion circuit further includes at least one bootstrap capacitor C2, which is used to connect to one end of at least the first high-side driving chip, and is used to turn on or maintain the driving state of the connected high-side driving switch. Optionally, on the substrate of the emission packaging module, the at least one bootstrap capacitor and the pins of the first high-side driving chip are arranged adjacent to each other.

[0061] Optionally, the emission packaging module further includes at least one decoupling capacitor corresponding to the at least one high-side driving chip and / or the at least one low-side driving chip. Each of the at least one high-side driving chip and / or at least one low-side driving chip in the emission packaging module is connected to the negative power supply (or ground) through the at least one decoupling capacitor. For example, all high-side driving chips are connected to the negative power supply (or ground) through one decoupling capacitor, and all low-side driving chips are connected to the negative power supply (or ground) through another decoupling capacitor; or, all high-side and low-side driving chips are connected to the negative power supply (or ground) through the same decoupling capacitor; or, each high-side driving chip is connected to the negative power supply (or ground) through a different decoupling capacitor, and each low-side driving chip is connected to the negative power supply (or ground) through a different decoupling capacitor. As Figure 4 shown, all the anode driving switches in the energy conversion circuit 401 are connected to the power supply through the first decoupling capacitor C3, and all the cathode driving switches in the energy release circuit 402 are connected to the negative power supply (or ground) through the second decoupling capacitor C4.

[0062] Generally, the operating voltages of the high-side driving chip and the low-side driving chip are respectively fixed at a certain voltage value. The power supply first passes through the decoupling capacitor and then supplies power to the high-side driving chip and the low-side driving chip, which can prevent the parasitic oscillation caused by the positive feedback path formed by the power supply VCC in the circuit, that is, prevent the current fluctuation formed in the power supply circuit when the circuit current size changes from affecting the normal operation of the circuit. Therefore, it can effectively eliminate the parasitic coupling between circuits to ensure the relative stability of the power supply. Optionally, the pins of the at least first high-side driving chip and / or the at least first low-side driving chip and the corresponding decoupling capacitor are arranged adjacent to each other.

[0063] As Figure 5 shown, Figure 5 is a schematic diagram of an embodiment of the arrangement of at least some components in the emission packaging module. At least two groups of VCSELs 50 in the emission packaging module are arranged in an array. The driving module includes a first high-side driving chip 511 and a first low-side driving chip 512, which are located around the VCSEL array 50. Optionally, the driving module further includes a second high-side driving chip 513, and the first high-side driving chip 511 and the second high-side driving chip 513 are respectively located on opposite sides of the VCSEL array, and are respectively used to drive the lasers in different regions of the VCSEL array. For example, as Figure 5As shown, the driving module includes a first high-side driving chip 511 located on the left side of the VCSEL array, and a second high-side driving chip 513 located on the right side of the VCSEL array. The VCSEL array is divided into two different regions, which are driven by the first high-side driving chip 511 and the second high-side driving chip 513 respectively. For example, the first high-side driving chip 511 is used to drive each group of VCSELs in the odd rows of the VCSEL array 50, and the second high-side driving chip 513 is used to drive each group of VCSELs in the even rows of the VCSEL array 50. Another example is that the first high-side driving chip 511 is used to drive each group of VCSELs in the upper half region of the VCSEL array 50, and the second high-side driving chip 513 is used to drive each group of VCSELs in the lower half region of the VCSEL array 50. In the case of a large number of columns in the VCSEL array, setting high-side driving chips on both sides of the VCSEL array can reduce the distance between the VCSEL and the high-side driving chip, improve the response speed of the VCSEL, and reduce circuit losses.

[0064] Alternatively, optionally, the driving module further includes a second low-side driving chip 514 and a first low-side driving chip 512, which are respectively located on opposite sides of the VCSEL array and are respectively used to drive the lasers in different regions of the VCSEL array. For example, as Figure 5 shown, the driving module includes a first low-side driving chip 512 located on the upper side of the VCSEL array 50, and a second low-side driving chip 515 located on the lower side of the VCSEL array 50. The first low-side driving chip 512 is used to drive each group of VCSELs in the right region of the VCSEL array 50 close to the first high-side driving chip 511. The second low-side driving chip 514 is used to drive each group of VCSELs in the left region of the VCSEL array 50 close to the second high-side driving chip 513. In the case of a large number of rows in the VCSEL array, setting low-side driving chips on both sides of the VCSEL array can reduce the distance between the VCSEL and the low-side driving chip, improve the response speed of the VCSEL, and reduce circuit losses, thereby avoiding the situation where the laser output power does not meet the requirements.

[0065] Moreover, compared with an example of a high-side driver chip and a low-side driver chip, an example of two high-side driver chips and / or two low-side driver chips can achieve driving a larger number of groups of VCSELs to emit light simultaneously, facilitating the selection of the number of VCSELs that emit light beams simultaneously according to detection requirements, thereby further improving the flexibility of detection. It can be understood that the emission packaging module only includes two high-side driver chips and one low-side driver chip. Optionally, the two high-side driver chips can drive different rows of groups of VCSELs respectively, and the one low-side driver chip can drive all columns of groups of VCSELs. Alternatively, the emission packaging module only includes one high-side driver chip and two low-side driver chips. Optionally, the one high-side driver chip can drive all rows of groups of VCSELs, and the two low-side driver chips can drive different columns of groups of VCSELs respectively.

[0066] Optionally, as Figure 5 shown, the emission packaging module includes a storage capacitor array 515. The storage capacitor array is arranged in two columns and is located on both sides of the VCSEL array 50 respectively. Optionally, each column of storage capacitors is located between the VCSEL array 50 and the driver chip. Optionally, each column of storage capacitors is located between the VCSEL array 50 and the high-side driver chip. By placing the storage capacitors close to the VCSELs, the distance between the storage capacitors and the corresponding VCSELs is reduced, which can reduce the parasitic parameters on the path between the storage capacitors and the corresponding VCSELs and transfer more energy to the VCSELs.

[0067] As Figure 6 shown, Figure 6 is a schematic diagram of an embodiment of the arrangement of at least some components in the emission packaging module. On the substrate, a column of storage capacitors 61 is arranged on each of the left and right sides of the VCSEL array 60. A high-side driver chip 62 is further provided on the side of each column of storage capacitors 61 facing away from the VCSEL array 60. The pins of the high-side driver chip 62 are arranged on the side of the high-side driver chip 62 facing away from the storage capacitors 61. The corresponding bootstrap capacitors 63 are arranged along the side of the high-side driver chip 62 facing away from the storage capacitors 61 respectively to be adjacent to the pins of the high-side driver chip 62. Optionally, a decoupling capacitor (not shown in the figure) corresponding to the high-side driver chip 62 is further provided on the side of the substrate facing away from the VCSEL array 60 and is adjacent to the pins of the high-side driver chip 62.

[0068] On the upper and lower sides of the VCSEL array 60, a low-side drive chip 65 is respectively arranged. The pins of the low-side drive chip 65 are arranged on the side of the low-side drive chip 65 facing away from the VCSEL array 60. The decoupling capacitors 65 corresponding to the low-side drive chip 65 are respectively arranged along the side of the low-side drive chip 65 facing away from the VCSEL array 60, so as to be adjacent to the pins of the low-side drive chip 65.

[0069] Figure 5 and Figure 6 In both of them, the energy storage capacitor is located between the VCSEL array and the high-side drive chip for illustration. Optionally, the energy storage capacitor can also be located between the VCSEL array and the low-side drive chip, which is not limited herein.

[0070] There are multiple implementation methods for the emission packaging module. For example Figure 1 As shown, optionally, at least two groups of VCSELs 103 in the emission packaging module are mounted on the substrate 101 through the COB process, and are wire-bonded to the pads on the substrate 101 to achieve electrical connection. Optionally, as Figure 1 shown, each VCSEL can be mounted on the substrate through conductive silver glue 107. Or, each VCSEL can also be soldered to the substrate through AuSn, or can be mounted on the substrate through DA glue. Optionally, each VCSEL is arranged in an array on the substrate, and the pads corresponding to the VCSELs in each row and each column are bonded. When the drive module drives the VCSEL group in the VCSEL array, the VCSEL group to be driven can be selected by gating the rows and columns.

[0071] Optionally, the at least one capacitor 105 in the emission packaging module is mounted on the substrate 101 through surface mount technology (SMT). Optionally, the at least one capacitor 105 can be connected to the corresponding VCSEL 103 through a lead 108.

[0072] Optionally, the light-passing cover plate 102 in the emission packaging module includes a cover plate area 1021 and a light window area 1022 located on the light-emitting paths of the at least two groups of VCSELs. Optionally, the cover plate area 1021 is made of stainless steel or kovar alloy. Optionally, the coefficient of thermal expansion of the cover plate area 1021 is within [12×10 -6 / deg, 15×10 -6 / deg], and the coefficient of thermal expansion of the substrate 101 is within [10×10 -6 / deg, 12×10 -6 / deg]. In this way, there is a relatively small thermal mismatch between the materials of the cover plate and the substrate, avoiding the packaging failure of the emission packaging module.

[0073] Optionally, the cover plate area 1021 is mounted to the substrate 101 by a first mounting glue and is mounted to the optical window area 1022 by a second mounting glue. The first mounting glue and the second mounting glue may be the same or different. Optionally, the first mounting glue is a one-component thermosetting epoxy resin, and the second mounting glue is a one-component thermosetting silicone rubber.

[0074] Optionally, the substrate 101 is a BT resin-based copper clad laminate. Optionally, the area of the substrate 101 in contact with the at least two groups of VCSELs 103 is filled with metal. For example, copper filling holes are designed in the substrate corresponding to the VCSEL array area, which can make the VCSEL area reach a higher thermal conductivity.

[0075] Optionally, the emission packaging module is packaged in a Ball Grid Array (BGA) packaging form to facilitate mounting on the circuit board in the emission module.

[0076] Optionally, as Figure 1 shown, the drive module 104 is pre-packaged by a Chip Scale Package (CSP) process. CSP is a standard type of packaging that does not involve specific packaging technologies. The ratio of the core area to the packaging area in CSP packaging is about 1:1.1. There are various CSP packaging technologies, such as small chip packaging technologies like uBGA, WBGA, TinyBGA, FBGA, etc. Compared with the case where each component in the directly driven module without pre-packaging is mounted on the substrate by the COP process, a large number of wire bonds are required in the wire bonding form, the processing is relatively low, and the integration degree is poor. In this example, pre-packaging the drive module by the CSP process is beneficial to simplify the manufacturing process of the overall System in Package (SIP) packaging of the emission packaging module and improve the SIP integration degree. Optionally, the drive module 104 is pre-packaged in a BGA packaging form by the CSP process and is mounted to the substrate 101 through ball pins 110.

[0077] Optionally, as Figure 1 shown, the drive module 104 is mounted to the substrate 101 by a flipchip process. In this process, the front side of the drive chip in the drive module 104 faces the substrate and is mounted to the substrate 101. Optionally, the drive module can also be mounted to the substrate by a Chip on Board (COB) process and then wire bonded to the pads on the substrate.

[0078] There are various ways for the packaging process of the emission packaging module. In one example, the packaging process of the emission packaging module includes a capacitor mounting process, a VCSEL and drive module mounting process, a light cover mounting process, a BGA ball mounting process, and a substrate cutting process.

[0079] Optionally, the VCSEL mounting process is after the capacitor mounting process. Optionally, the capacitor mounting process includes baking the packaging substrate, mounting the capacitors in the emission packaging module onto the baked substrate through SMT, and cleaning the mounted capacitors and the substrate. Optionally, the VCSEL and drive module mounting process includes: after applying silver paste and bonding the chips to the VCSEL, baking and curing the silver paste; after applying glue and bonding the chips to the drive chip in the drive module, baking and curing the silver paste; respectively performing Land Grid Array (LGA) packaging on the baked and cured VCSEL and drive module, and then performing plasma cleaning; after cleaning, performing wirebonding on the packaged VCSEL and drive module, and inspecting after wirebonding.

[0080] Optionally, the light cover mounting process includes applying glue to the light-passing cover plate and curing after mounting it to the cover plate. Optionally, before the BGA ball mounting process, in an example where components need to be mounted on the back of the substrate, the components can also be mounted on the back of the substrate using SMT technology. After performing the BGA ball mounting process on the substrate, the substrate is cut.

[0081] The embodiment of the present application further provides a lidar, including an emission packaging module for emitting laser beams, and the emission packaging module can be the emission packaging module described in any of the above. As Figure 7 shown, Figure 7 is a schematic diagram of an embodiment of the lidar in the embodiment of the present application. The lidar 71 includes the emission module 72 described above, and a receiving module 73 for detecting the echo laser reflected back from the beam emitted by the emission module 72. Optionally, the lidar is a solid-state lidar. Of course, the emission packaging module in the present application can also be used in infrared detectors, projector light sources, 3D tof modules of mobile phones, etc., without limitation here. Optionally, the lidar can further include a scanning component, and the scanning component can be, for example, a galvanometer, a rotating mirror, a mechanical rotating platform, etc. The present application does not limit whether the lidar includes a scanning component.

[0082] The embodiments of the present application have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of the technology in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A transmitting packaging module, characterized in that, Comprising: a substrate, and a light-passing cover plate covering the substrate, an airtight space being formed between the substrate and the light-passing cover plate; inside the airtight space, at least two groups of vertical cavity surface emitting lasers, a driving module and at least one capacitor are fixed on the substrate, and the vertical cavity surface emitting lasers and the driving module are respectively independently packaged on the same substrate; wherein, each group of vertical cavity surface emitting lasers includes at least one vertical cavity surface emitting laser; wherein, the at least one capacitor includes an energy storage capacitor for storing energy, and the driving module is used to drive at least part of the at least two groups of vertical cavity surface emitting lasers to emit light through the energy in the energy storage capacitor; wherein, the driving module includes at least a first high-side driving chip and at least a first low-side driving chip; the at least one capacitor further includes at least one decoupling capacitor corresponding to the first high-side driving chip and / or the first low-side driving chip, and the first high-side driving chip and / or the first low-side driving chip are connected to the ground through the corresponding decoupling capacitor.

2. The emission packaging module according to claim 1, wherein The first high-side driving chip and the first low-side driving chip drive at least one group of the at least two groups of vertical cavity surface emitting lasers that are selected to emit light by selecting at least one group of the at least two groups of vertical cavity surface emitting lasers.

3. The emission packaging module according to claim 2, wherein The at least two groups of vertical cavity surface emitting lasers are a vertical cavity surface emitting laser array; The driving module further includes a second high-side driving chip, and the first high-side driving chip and the second high-side driving chip are respectively located on opposite sides of the vertical cavity surface emitting laser array, and are respectively used to drive different groups of vertical cavity surface emitting lasers in the vertical cavity surface emitting laser array.

4. The emission packaging module according to claim 2, wherein The at least two groups of vertical cavity surface emitting lasers are a vertical cavity surface emitting laser array; The driving module further includes a second low-side driving chip, and the first low-side driving chip and the second low-side driving chip are respectively located on opposite sides of the vertical cavity surface emitting laser array, and are respectively used to drive different groups of vertical cavity surface emitting lasers in the vertical cavity surface emitting laser array.

5. The emission package module according to claim 1, characterized in that, The at least one capacitor further includes at least one bootstrap capacitor for turning on or maintaining the driving state of the first high-side driving chip.

6. The emission packaging module according to claim 5, wherein The pins of the first high-side driving chip and / or the first low-side driving chip are arranged adjacent to the corresponding decoupling capacitor.

7. The emission packaging module according to claim 1, wherein The energy storage capacitor is arranged adjacent to the at least two groups of vertical cavity surface emitting lasers.

8. The emission packaging module according to any one of claims 1 to 7, characterized in that, The light-passing cover plate includes a cover plate area and a light window area located on the light emitting path of the at least two groups of vertical cavity surface emitting lasers.

9. The emission packaging module according to any one of claims 1 to 7, characterized in that The airtight space is filled with an inert gas.

10. The emission packaging module according to any one of claims 1 to 7, characterized in that, The substrate is a BT resin-based copper clad laminate; and / or, The area of the substrate in contact with the at least two groups of vertical cavity surface emitting lasers is filled with metal.

11. A transmitting module, characterized in that, Comprising the emission packaging module according to any one of claims 1 to 10 and a circuit board; A power supply and an energy charging circuit are further arranged on the circuit board; The circuit board is electrically connected to the emission packaging module.

12. A lidar, characterized in that, Comprising the emission packaging module according to any one of claims 1 to 10.

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