CN110459951B

CN110459951B - Laser, laser emitting board assembly, laser radar and laser packaging method

Info

Publication number: CN110459951B
Application number: CN201910702011.7A
Authority: CN
Inventors: 李娜; 向少卿
Original assignee: Hesai Technology Co Ltd
Current assignee: Hesai Technology Co Ltd
Priority date: 2019-07-31
Filing date: 2019-07-31
Publication date: 2021-05-11
Anticipated expiration: 2039-07-31
Also published as: CN113193471A; CN113193471B; CN110459951A

Abstract

The invention relates to a laser comprising: the device comprises a substrate, a positioning part and a positioning part, wherein the substrate is provided with the positioning part; a laser chip disposed on the substrate, the laser chip having a light emitting surface; and the laser beam shaping element is positioned by the positioning part and is opposite to the light-emitting surface of the laser chip. The invention also relates to a packaging method of the laser and a laser radar comprising the laser. According to the technical scheme, the limit (only limited by the size of the fast axis) of the angular resolution of the laser emitting plate assembly in the vertical direction can be greatly improved, and the compressed fast axis divergence angle and the light beam directivity are effectively controlled and the distance measuring performance is improved by processing the accurate positioning structure on the silicon base.

Description

Laser, laser emitting board assembly, laser radar and laser packaging method

Technical Field

The invention relates to the technical field of laser, in particular to a laser, a laser emitting plate assembly comprising the laser, a laser radar and a laser packaging method.

Background

LiDAR is a general name of laser active detection sensor equipment, and the working principle of the LiDAR is roughly as follows: laser radar's transmitter launches a bundle of laser, and after laser beam met the object, through diffuse reflection, returned to laser receiver, radar module multiplies the velocity of light according to the time interval of sending and received signal, divides by 2 again, can calculate the distance of transmitter and object. Depending on the number of laser beams, there are generally, for example, a single line laser radar, a 4-line laser radar, an 8/16/32/64-line laser radar, and the like. One or more laser beams are emitted along different angles in the vertical direction and scanned in the horizontal direction to realize the detection of the three-dimensional profile of the target area. The multiple measurement channels (lines) correspond to scan planes at multiple angles, so that the more laser beams in the vertical field of view, the higher the angular resolution in the vertical direction, and the greater the density of the laser point cloud. Fig. 1A schematically shows an example of a lidar. The laser radar is a 16-line laser radar, namely 16 lines of laser beams including L1, L2, …, L15 and L16 can be emitted in the vertical plane of the drawing for detecting the surrounding environment. In the detection process, the laser radar can rotate along the vertical axis of the laser radar, in the rotation process, each channel of the laser radar sequentially emits laser beams according to a certain time interval (for example, 1 microsecond) and detects the laser beams so as to complete line scanning on one vertical view field, and then line scanning of the next vertical view field is performed at a certain angle (for example, 0.1 degree or 0.2 degree) in the horizontal view field direction, so that point cloud is formed by detecting for multiple times in the rotation process, and the condition of the surrounding environment can be sensed.

Most of the semiconductor laser chips currently used in mechanical laser radars are edge-emitting. The light emitting surface of the edge-emitting laser has a fast axis direction and a slow axis direction, as schematically shown in fig. 1B, in which the dimension of the edge-emitting laser in the slow axis direction is large, for example, on the order of hundreds of μm, and the dimension in the fast axis direction is small, for example, on the order of ten μm. In addition, fig. 1B schematically shows a negative electrode N of the laser chip, and a positive electrode P is, for example, located on a lower surface opposite to the negative electrode N.

Fig. 1C schematically shows a mounting of a laser chip in a mechanical lidar. With reference to fig. 1A, 1B, and 1C, the circuit board of fig. 1C is disposed in the laser radar in the vertical direction in fig. 1A, on which a plurality of edge-emitting type laser chips shown in fig. 1B are disposed in the vertical direction (vertical direction in fig. 1A) of the focal plane of the exit optical system of the laser radar, the laser chips emitting laser beams from the light-emitting surface, the laser beams being directed to the exit optical system. Since the slow axis direction of the light-emitting surface is parallel to the electrode, and in the conventional application process, the electrode of the laser chip is directly attached to the circuit board, the slow axis direction of the light-emitting surface is parallel to the circuit board (as shown in fig. 1C). In fig. 1C, a plurality of edge-emitting laser chips are arranged along the vertical direction of the laser radar, and therefore the slow axis direction (vertical dotted line in fig. 1C) of the light emitting surface of the laser chip in fig. 1C is the vertical direction in fig. 1A, and the fast axis direction of the light emitting surface is the direction perpendicular to the paper surface. For the laser radar, if the limit of the vertical direction angular resolution needs to be improved, the size of the light emitting surface in the vertical direction needs to be as small as possible. In the structure shown in fig. 1C, a plurality of laser chips need to be arranged along the vertical direction of the laser radar, while the slow axis direction of the laser chips needs to be arranged along the vertical direction in the figure, and the slow axis size of the edge-emitting laser is large (on the order of hundreds of μm), so that the laser chips cannot be arranged more densely within the limited vertical direction size range of the focal plane, which is not favorable for improving the limit of the vertical direction angular resolution. Based on the above, there is a solution in the prior art to place the circuit board horizontally, as shown in fig. 2.

In the solution of fig. 2, the circuit board is horizontally disposed, and the laser chip is directly attached to the circuit board. It has the following disadvantages.

First, for the lidar, each different vertical angle requires a laser (at the focal plane of the transmitting lens) with different vertical heights, and thus a corresponding number of circuit boards are required to be horizontally placed (for example, 64 circuit boards are required for 64 lines), and are staggered in the vertical direction. Therefore, within a certain size, the limit of the vertical angular resolution of the lidar is greatly limited by the thickness of the circuit board, the height of components on the circuit board, and the like.

Secondly, in order to ensure the consistency of the vertical angle of the laser radar, the position of a circuit board bearing each laser needs to be accurately fixed, and the process is complicated.

Accordingly, there is a continuing need in the art for lasers and lidar capable of improving vertical angular resolution.

The statements in the background section are merely prior art as they are known to the inventors and do not, of course, represent prior art in the field.

Disclosure of Invention

In view of at least one of the deficiencies of the prior art, the present invention provides a laser comprising: the device comprises a substrate, a positioning part and a positioning part, wherein the substrate is provided with the positioning part; a laser chip disposed on the substrate, the laser chip having a light emitting surface; and the laser beam shaping element is positioned by the positioning part and is opposite to the light-emitting surface of the laser chip.

According to an aspect of the invention, the positioning portion includes one or more of a V-groove, a U-groove, and a step.

According to one aspect of the invention, the laser beam shaping element comprises an optical fiber, a cylindrical lens, a D-lens or an aspherical mirror.

According to an aspect of the present invention, the laser chip is an edge-emitting type, and the light emitting surface has a slow axis direction and a fast axis direction, wherein the slow axis direction is parallel to an extending direction of the laser beam shaping element, and the laser beam shaping element is a fast axis compression element configured to compress a divergence angle of the laser light emitted from the light emitting surface in the fast axis direction.

According to an aspect of the present invention, the base is a silicon base (an etchable material capable of precisely controlling an etching depth), and the positioning portion is formed on the silicon base by an etching process.

According to one aspect of the invention, the laser further comprises an electrode disposed on the substrate, the electrode configured to power the laser chip.

According to one aspect of the invention, the electrodes comprise a positive electrode and a negative electrode separated by a separator.

According to an aspect of the present invention, the positive electrode and the negative electrode are each provided on the same surface as the laser chip on the substrate and on a side surface perpendicular to the light emitting surface on the substrate.

According to an aspect of the present invention, the positive electrode and the negative electrode are each provided on the same surface as the laser chip on the substrate and on an end surface parallel to the light emitting surface on the substrate.

According to an aspect of the present invention, a center of the laser beam shaping element is flush with a center of a light emitting surface of the laser chip.

The present invention also provides a laser emitter plate assembly comprising: a circuit board; and a plurality of lasers as described above, which are disposed on the circuit board, and light emitting surfaces of laser chips of the lasers face in the same direction.

According to an aspect of the present invention, the plurality of lasers are soldered on the circuit board, and a slow axis direction of light emitting faces of the plurality of lasers is perpendicular to the circuit board.

According to an aspect of the present invention, the plurality of lasers are soldered on the circuit board, and a slow axis direction of light emitting faces of the plurality of lasers is parallel to the circuit board.

According to one aspect of the invention, the laser emitting board assembly comprises a plurality of circuit boards, each circuit board is provided with a plurality of lasers, and light emitting surfaces of laser chips in the lasers on the circuit boards are mutually staggered in the fast axis direction.

According to one aspect of the present invention, light emitting surfaces of laser chips in the plurality of lasers on the circuit board are shifted from each other in the fast axis direction.

The invention also relates to a lidar comprising a laser transmitter plate assembly as described above.

The invention also relates to a packaging method of the laser, which comprises the following steps: providing or preparing a substrate; forming a positioning part on the substrate through etching or chemical corrosion; mounting a laser chip on the substrate; and positioning a laser beam shaping element on the substrate by using the positioning part, so that a light emitting surface of the laser chip is opposite to the laser beam shaping element.

According to one aspect of the invention, the substrate is a silicon substrate.

According to one aspect of the invention, the method further comprises making the center of the laser beam shaping element flush with the center of the light emitting face of the laser chip.

The limit of the vertical angular resolution of the laser emitting plate assembly (limited only by the dimension of the fast axis) can be greatly improved. Compared with the arrangement mode shown in fig. 1C, the technical scheme of the invention can realize accurate fast axis compression while the light emitting surface of the chip is turned by 90 degrees. Materials such as silicon and the like can accurately control the processing depth and size by utilizing an etching process, a base with accurate pattern size is prepared, the fast axis divergence angle and the light beam directivity after compression are effectively controlled, and the distance measuring performance is improved. And the light emitting surface of the chip is turned over by 90 degrees, so that the measurement errors of a ground lane line, a pedestrian line and a far ground can be reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1A is a schematic diagram of a lidar; fig. 1B is a schematic diagram of an edge-emitting laser chip;

fig. 1C is a schematic diagram of one arrangement of a conventional semiconductor laser chip and circuit board;

fig. 2 is a schematic view of another arrangement of a conventional semiconductor laser chip and circuit board;

fig. 3A is a perspective view of a laser according to a first aspect of the present invention from the front side, fig. 3B is a perspective view of the laser from the rear side, and fig. 3C and 3D are rendering views of fig. 3A and 3B, respectively;

fig. 4A shows a divergence angle of a laser beam emitted from a laser chip in a slow axis direction and a divergence angle in a fast axis direction; fig. 4B and 4C show the case where the divergence angle of the laser beam emitted from the laser chip in the fast axis direction is reduced after passing through the D lens and the optical fiber, respectively;

FIGS. 5A and 5B illustrate a laser according to another embodiment of the present invention;

FIGS. 6A and 6B illustrate a laser according to another embodiment of the present invention, and FIGS. 6C and 6D are rendering diagrams of FIGS. 6A and 6B, respectively;

FIGS. 7A and 7B illustrate a variation of the laser according to FIGS. 6A and 6B;

FIG. 8 illustrates a laser emitter plate assembly according to a preferred embodiment of the present invention;

FIG. 9A shows a laser emitter plate assembly according to a preferred embodiment of the present invention, and FIG. 9B shows a laser emitter plate assembly according to another preferred embodiment of the present invention;

FIG. 10 illustrates a laser emitter plate assembly according to a preferred embodiment of the present invention;

FIG. 11 illustrates a laser emitter plate assembly according to a preferred embodiment of the present invention; and

fig. 12 illustrates a method of packaging a laser according to the present invention.

Detailed Description

In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection, either mechanically, electrically, or in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or uses of other materials.

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.

A first aspect of the invention relates to a laser 10, as shown in fig. 3A, 3B, 3C and 3D. Reference is made to fig. 3A and 3B in detail, wherein fig. 3A is a perspective view of the laser 10 viewed from the front side, fig. 3B is a perspective view of the laser 10 viewed from the rear side, and fig. 3C and 3D are rendering views of fig. 3A and 3B, respectively, to more clearly show the detailed structure of the laser.

As shown in fig. 3A and 3B, the laser 10 includes a substrate 11, a laser chip 12, and a laser beam shaping element 13. The laser chip 12 is disposed on the substrate 11, and the laser chip 12 has a light emitting surface 121, and a laser beam is emitted from the light emitting surface 121 after being driven by a voltage. The laser beam shaping element 13 faces the light emitting surface 121. Wherein, in order to accurately position the laser beam shaping element 13 on the substrate, a positioning portion 111 for positioning the laser beam shaping element 13 is formed on the substrate 11. Fig. 3B and 3D more clearly illustrate the positioning portion 111.

The principle and manner of operation of the laser 10 is as follows. The substrate 11 provides support and positioning for the other optoelectronic components of the laser 10. The laser chip 12 is driven by a voltage, and emits a laser beam from the light emitting surface 121, and since the light emitting surface 121 is opposite to the laser beam shaping element 13, the emitted laser beam is optically shaped and modulated by the laser beam shaping element 13, changes some optical parameters and properties thereof, and then continues to emit. Those skilled in the art will appreciate that the appropriate laser beam shaping element 13 and its implemented functions may be selected according to the actual requirements. For example, the laser beam shaping element 13 may compress the laser beam emitted from the light emitting surface 121 in a certain direction to reduce the divergence angle in the certain direction. Alternatively, the laser beam shaping element 13 may adjust the diameter of the laser beam emitted from the light emitting surface 121. The laser beam shaping element 13 may comprise one or more of an optical fiber, a cylindrical lens, a D-lens or an aspherical mirror. The invention is not limited to the specific type of laser beam shaping element 13 and the shaping and modulation achieved. All within the scope of the present disclosure. Preferably, the positioning portion 111 is disposed such that the center height of the laser beam shaping element 13 is equal to the center of the light emitting surface 121 of the laser chip 12, so as to facilitate the adjustment of the optical parameters of the laser beam by the laser beam shaping element 13.

According to a preferred embodiment of the present invention, the laser chip 12 is an edge-emitting type laser chip, such as an edge-emitting type of DBR (distributed Bragg Reflector) design, an edge-emitting type of DFB (distributed feedback) design, or the like. The light emitting surface of the edge emitting laser has a slow axis direction and a fast axis direction. The fast axis direction and the slow axis direction of the light emitting surface of the laser chip 12 are schematically shown in fig. 3A. The light-emitting surface of the edge-emitting laser generally has a large dimension in the slow axis direction and a small dimension in the fast axis direction (i.e., the dimension in the thickness direction of the laser chip 12 in the drawing). The divergence angle of a laser beam emitted from an edge-emitting laser is generally different between the fast axis direction and the slow axis direction, and generally, the divergence angle is small in the slow axis direction and large in the fast axis direction. Fig. 4A shows a divergence angle θ in the slow axis direction and a divergence angle α in the fast axis direction of the laser beam emitted from the laser chip. It is apparent that the divergence angle α in the fast axis direction is significantly larger than the divergence angle θ in the slow axis direction. Those skilled in the art will readily appreciate that the divergence angles α and θ shown in fig. 4A are merely illustrative and do not mean that the divergence angle of an actual laser chip is so large. According to one embodiment, the divergence angle θ in the slow axis direction is, for example, about 10 degrees, and the divergence angle α in the fast axis direction is, for example, about 30 degrees.

The laser chip 12 is, for example, attached on the substrate 11 so that the light emitting surface 121 is perpendicular to the attached surface, parallel to the extending direction of the positioning portion 111, as shown in fig. 3A and 3B. The laser chip 12 and the laser beam shaping element 13 are disposed on the substrate 11 such that the slow axis direction of the light emitting surface 121 is parallel to the extending direction of the laser beam shaping element 13, thereby reducing the light emitting surface height of the laser 10, i.e., reducing the size of the light emitting surface in the vertical direction in fig. 3. The laser beam shaping element 13 is, for example, a fast axis compression element, and can compress the divergence angle of the laser beam emitted from the light emitting surface 121 in the fast axis direction, so that the divergence angle of the emitted laser beam in the fast axis direction is smaller and the convergence degree is higher after the emitted laser beam passes through the laser beam shaping element 13. Fig. 4B and 4C show a case where the divergence angle α in the fast axis direction of the laser beam emitted from the light emitting surface 121 of the laser chip 12 is reduced after passing through the laser beam shaping element 13. Fig. 4B shows a case where a D lens is used as the laser beam shaping element 13, and fig. 4C shows a case where an optical fiber is used as the laser beam shaping element 13. The dotted line shows the optical path without compression, and the corresponding solid line shows the optical path after the fast axis compression. As shown, the divergence angle α of the laser beam in the fast axis direction is significantly reduced after passing through the D lens or the optical fiber.

In addition, the laser chip and the laser beam shaping element 13 shown in fig. 4B and 4C are spaced apart from each other by a certain distance for illustrative purposes only and do not limit the scope of the present invention, and may be closely adjacent to each other. According to one embodiment of the invention, the divergence angle α of the laser beam in the fast axis direction is compressed to be comparable to the divergence angle θ in the slow axis direction, e.g. reduced from 30 degrees to e.g. 10 degrees, after passing through the laser beam shaping element 13.

According to a preferred embodiment of the present invention, the laser beam shaping element 13 may comprise one or more of an optical fiber, a cylindrical lens, a D-lens or an aspherical mirror. Shaping and modulation of the laser beam emitted from the light emitting surface 121 can be realized by the various examples of the laser beam shaping element 13 listed above. For example, most commonly, the divergence angle of the laser beam along the fast axis is compressed by a cylindrical lens.

According to a preferred embodiment of the present invention, the positioning portion 111 includes one or more of a V-shaped groove, a U-shaped groove, and a step for precisely positioning the laser beam shaping element 13. The positioning portion 111 is, for example, a microstructure located near one end of the substrate, for example, a microstructure such as a μm-sized V-groove or other groove shape, step, etc. may be processed on the front end of the silicon base by etching process, and the microstructure is used for precise positioning of the laser beam shaping element 13. In the case of a V-groove, the laser beam shaping element 13 may be directly embedded in the V-groove for positioning. In the case of a step, the laser beam shaping element 13 may be positioned immediately adjacent to the step. It will be readily understood by those skilled in the art that after the laser beam shaping element 13 has been accurately positioned, it may be secured in place by other additional means, such as by means of an adhesive, for example, to the substrate 11.

It is shown in fig. 3A and 3B that the positioning portion 111 includes a V-shaped groove, for example, at a position near the end of the base 11. Wherein the laser beam shaping element 13 is an optical fiber and is clamped in the V-shaped groove. It is shown in fig. 3A and 3B that the positioning portion 111 further includes a step. The combination of the V-shaped groove and the step helps to accurately position the laser beam shaping element 13 with respect to the light emitting surface 121 of the laser chip 12, and to accurately modulate and shape the laser beam emitted from the light emitting surface 121. Those skilled in the art will appreciate that the precise positioning of the laser chip 121 with respect to the laser beam shaping element can be achieved by a V-shaped groove alone or a step alone as the positioning portion. These are all within the scope of the present invention.

Note that the positioning portion referred to in the present invention refers to a portion or an element that contributes to positioning of the laser beam shaping element, and is not limited to positioning of the laser beam shaping element by the positioning portion alone without requiring other parts. As will be readily understood by those skilled in the art. For example, in the embodiment of fig. 3A and 3B, in addition to the positioning portion 111, the positioning effect thereof may be enhanced by means of an adhesive or the like. And will not be described in detail herein.

The semiconductor laser structure with the precise positioning structure shown in fig. 3A, 3B, 3C, and 3D can conveniently modulate the light beam of the laser chip, and is convenient for installation.

Fig. 5A, 5B show a laser 10 according to another embodiment of the invention, in which the positioning portion 111 comprises a step against which the laser beam shaping element 13 is positioned as a D-lens. The laser beam emitted from the light emitting surface 121 of the laser chip 12 enters the plane side of the D lens and is emitted from the other side with a smaller divergence angle in the fast axis direction. Other shapes and types of positioning portions and laser beam shaping elements are also contemplated by those skilled in the art having the benefit of the teachings and teachings of the present invention and are within the scope of the present invention.

According to a preferred embodiment of the invention, the susceptor is a susceptor made of silicon (preferably high-resistivity silicon) or of another material capable of precisely controlling the machining depth by means of etching or chemical etching processes. The positioning portion 111 is formed on the silicon base by an etching or chemical etching process. Compared with a ceramic material, silicon is easier to etch, and the position and the size of the positioning part are accurately controlled, so that the laser beam shaping element 13 can be accurately positioned by the positioning part 111, and a laser beam emitted from the light emitting surface of the laser chip is shaped and modulated, and the divergence angle along the fast axis direction is reduced.

According to a preferred embodiment of the present invention, the laser 10 further comprises an electrode 14 disposed on the substrate, the electrode being configured to power the laser chip. The following detailed description refers to the accompanying drawings.

An electrode 14 according to a preferred embodiment of the present invention is shown in fig. 3A and 3B. As shown in fig. 3A, the electrode 14 includes a positive electrode 141 and a negative electrode 142. The positive electrode 141 and the negative electrode 142 are, for example, metal plates or metal thin layers (e.g., gold foils) attached to the surface of the substrate 11 by, for example, plating. As shown in fig. 3A, the positive electrode 141 and the negative electrode 142 are spaced apart from each other by a spacer 16, the spacer 16 being, for example, an integral part of the substrate 11 without a metal plate or a thin layer of metal thereon, thereby spacing the positive electrode 141 and the negative electrode 142 apart (as shown more clearly in fig. 3C and 3D). Alternatively, the spacer 16 may be a single non-conductive layer, such as a silicon dioxide layer. The positive electrode 141 and the negative electrode 142 may be disposed on the same surface of the substrate as the laser chip and on a side surface of the substrate perpendicular to the light emitting surface. The positive electrode 141 and the negative electrode 142, for example, each extend across both surfaces of the substrate 11, i.e., the top surface and the side surface on the side close to the viewer in fig. 3A, for example, for easy mounting. Wherein the portion of the electrode soldered to the circuit board is located on the side surface of the base. In fig. 3A, the directions of extension of the upper portions (portions on the same surface as the laser chip on the substrate) of the positive electrode 141 and the negative electrode 142 (as indicated by the double-headed arrows on the upper portions of the positive electrode 141 in fig. 3A) are substantially parallel to the light emitting surface 121 of the laser chip 12 and to the direction of extension of the laser beam shaping element 13. The lower surface of the laser chip 12 is attached to the negative electrode 142, and the potential of the lower surface is the same as that of the negative electrode 142; the upper surface of the laser chip 12 is coupled to the positive electrode 141 by a wire (such as a gold wire) 15, and the potential is the same as that of the positive electrode 141. The positive electrode 141 and the negative electrode 142 are spaced apart by a substrate having no electrode material (e.g., as shown by a V-groove penetrating the upper surface of the substrate on the left side in fig. 3A). When the laser 10 is energized, a voltage difference exists between the positive electrode 141 and the negative electrode 142, thereby driving the laser chip 12 to emit a laser beam from the light emitting surface thereof. In addition, the polarities of the positive electrode 141 and the negative electrode 142 may be interchanged, which is also within the scope of the present disclosure. The arrangement of the electrodes of fig. 5A and 5B is similar to that of fig. 3A and 3B and will not be described again here.

The arrangement of the components of the laser 10 shown in fig. 3A, 3B, 5A and 5B is very compact, and particularly when used at the transmitting end of the lidar, the arrangement can be dense, and the limit of the spacing between the lasers 10 can be the thickness of the laser chip (i.e., the dimension along the fast axis direction), which greatly improves the limit of the angular resolution of the lidar in the vertical direction.

Fig. 6A and 6B show a laser 20 according to another embodiment of the present invention, and fig. 6C and 6D are rendering views of fig. 6A and 6B, showing the structure thereof more clearly. The laser 20 includes a substrate 21, a laser chip 22, and a laser beam shaping element 23, wherein the substrate 21 has a positioning portion 211 therein for assisting the precise positioning of the laser beam shaping element 23, similar to that shown in fig. 3A and 3B, and the description thereof is omitted here. The laser 20 also has therein an electrode 24 including a positive electrode 241 and a negative electrode 242, the laser chip 22 being attached to the negative electrode 242, the upper surface of the laser chip 22 being connected to the positive electrode 241 by a wire (such as a gold wire) 25. As shown in fig. 6A and 6B, the positive electrode 241 and the negative electrode 242 are spaced apart from each other by a spacer. The positive electrode and the negative electrode are both arranged on the same surface of the substrate as the laser chip and on an end surface of the substrate parallel to the light-emitting surface. For example, the positive electrode 241 and the negative electrode 242 also extend over both surfaces of the substrate 21, i.e., the top surface and one of the end surfaces in fig. 6A. As shown in fig. 6A and 6B, the upper portions (portions on the same surface as the laser chip on the substrate) of the positive electrode 241 and the negative electrode 242 extend in a direction perpendicular to the light emitting surface 221 of the laser chip 22 and to the extending direction of the laser beam shaping element 23. Wherein, the part of the electrode welded with the circuit board is positioned on the end surface of the base. The positive electrode 241 and the negative electrode 242 are spaced apart by a substrate having no electrode material. In fig. 7A and 7B, the electrodes 24 are arranged in a manner similar to that of fig. 6A and 6B, but a D lens and a step positioning portion are employed, and no further description is given here.

When the laser device of the above embodiment of the present invention is applied to a laser radar, the angular resolution limit of the mechanical laser radar in the vertical direction can be further improved. This advantage will be apparent and readily appreciated from the description that follows.

A second aspect of the invention relates to a laser emitter plate assembly comprising: a circuit board and a plurality of lasers as described above. The lasers are arranged on the circuit board, and light emitting surfaces of laser chips of the lasers face in the same direction, thereby emitting laser beams in a common direction.

Fig. 8 shows a laser emitter board assembly 30 according to a preferred embodiment of the present invention, including a circuit board 31 and a plurality of lasers, such as the laser 10 shown in fig. 3A, 3B, 5A, 5B, disposed on the circuit board, with

electrodes

141 and 142 soldered to

pads

311 and 312 of the circuit board 31. As shown in fig. 8, the slow axis direction of the light emitting surfaces of the plurality of lasers 10 is perpendicular to the circuit board 31. In operation, the circuit board 31 provides a driving voltage for the laser chip 12 in the laser 10 through the

pads

311 and 312 thereon, and the laser chip 12 emits a laser beam from the light emitting surface 121 thereof, and continues to propagate with a reduced divergence angle in the fast axis direction after being shaped by the laser beam shaping element.

Note that fig. 8 suitably shows the laser 10 having an optical fiber as the laser beam shaping element, but it will be readily understood that other types of laser beam shaping elements may be provided, such as a cylindrical lens, a D lens, or an aspherical mirror. The double-headed arrows in fig. 8 show the vertical direction of the lidar of fig. 1A. Compare with the mode of setting up of the laser instrument chip of fig. 1C, among the technical scheme of fig. 8, realized the light emitting area upset 90 of laser instrument chip, simultaneously, the fast axle direction (the size is less) of laser instrument chip coincides with lidar's vertical direction, therefore can arrange more laser instrument chips in lidar's vertical direction, improves lidar at the angular resolution of vertical direction.

Still more preferably, as shown in fig. 9, the laser emitting board assembly 30 includes a plurality of circuit boards 31, each of which is provided with a plurality of the lasers 10, wherein the light emitting surfaces 121 of the laser chips 12 in the lasers 10 on the plurality of circuit boards 31 are mutually shifted in the fast axis direction. For example, in fig. 9, four circuit boards 31 are provided along the slow axis direction, and four lasers 10 are provided on each circuit board for a total of 16 lasers 10. Along the fast axis in fig. 9 (i.e., corresponding to the laser radar vertical direction of fig. 8), the positions of the 16 lasers 10 are staggered from each other and do not coincide. In other words, when arranged into a lidar, the 16 lasers 10 are each located at a different vertical height of the focal plane of the lidar exit optical system, so that a laser beam can be emitted at different positions for detecting the surroundings.

Fig. 9A includes a plurality of the circuit board of fig. 8 and the lasers thereon, and is a view seen from the left side direction of fig. 8, while the gold wires, the laser beam shaping elements, and the like are omitted for clarity. As shown in fig. 9A, the plurality of circuit boards 31 are stacked in the slow axis direction of the light emitting surface. Through this kind of mode of setting and laser module as above, can greatly improve the angular resolution limit of laser radar in the vertical direction. For example, in fig. 9A, although the laser chips of the lasers 10 on the single circuit board 31 are limited by the thickness of the substrate, and need to be spaced apart by a certain distance in the vertical direction (fast axis direction) in the drawing (the limit of stacking is the bottom surface of the upper laser, which contacts the top surface of the lower laser), the lasers on different circuit boards 31 need not be limited by the thickness of the substrate, and may be staggered in the fast axis direction. In one extreme case, the laser chips of the lasers on the plurality of circuit boards are continuous in the fast axis direction. For example, as shown in fig. 9B, which schematically illustrates four circuit boards 31, each having a laser 10-1, 10-2, 10-3, and 10-4 thereon, wherein the lower surface of the laser chip of the laser 10-1 coincides with the upper surface of the laser chip of the laser 10-2, the lower surface of the laser chip of the laser 10-2 coincides with the upper surface of the laser chip of the laser 10-3, and the lower surface of the laser chip of the laser 10-3 coincides with the upper surface of the laser chip of the laser 10-4, as indicated by the dotted lines in fig. 9B. In this way, it is possible to arrange the lasers as much as possible in the vertical direction of the lidar. One skilled in the art will readily appreciate that multiple lasers may be disposed on each circuit board 31. This aspect of the invention therefore enables the limits of the angular resolution of the lidar in the vertical direction to be greatly increased relative to the arrangements of figures 1 and 2.

The welding mode of the bonding pad and the electrode shown in fig. 9 is suitable for the semiconductor laser devices shown in fig. 3A, 3B, 5A and 5B, and different heights of the semiconductor laser devices on the focal plane of the transmitting lens are realized through the arrangement of a plurality of circuit PCB boards, so that high angle resolution in the vertical view field direction is realized. The base has no influence on the final thickness, and the laser is staggered along the fast axis direction.

Fig. 10 shows a laser emitter board assembly 40 according to a preferred embodiment of the present invention, which includes a circuit board 41 and a plurality of lasers, such as the lasers 20 shown in fig. 6A, 6B, 7A and 7B. The lasers 20 are soldered on the

pads

411 and 412 of the circuit board 41 for obtaining a driving voltage through the

pads

411 and 412, and the slow axis direction of the light emitting faces of the laser chips 22 of the plurality of lasers 20 is parallel to the circuit board.

Fig. 11 shows a laser emitter plate assembly 40 according to a preferred embodiment of the present invention. The main difference between fig. 11 and fig. 10 is that fig. 11 includes multiple rows of lasers. It is easily understood that fig. 11 is a view seen from the left side of fig. 10. The light emitting surfaces of laser chips in the lasers on the circuit board are mutually staggered in the fast axis direction. As shown in fig. 11, the light emitting surfaces of the lasers in the plurality of rows of lasers are shifted from each other in the fast axis direction. Therefore, the arrangement density in the fast axis direction is realized as the size of the laser chip in the fast axis direction by the arrangement mode, and the limit of the angular resolution of the laser radar in the vertical direction is greatly improved.

The welding mode of the bonding pad and the electrode in the embodiment shown in fig. 11 is suitable for the semiconductor lasers shown in fig. 6A, 6B, 7A and 7B, and different heights of the semiconductor lasers on the focal plane of the emitting lens are realized by arranging the semiconductor lasers on a single circuit PCB, so that high angular resolution in the vertical view field direction is realized.

A third aspect of the invention also relates to a lidar comprising a laser

transmitter plate assembly

30 or 40 as described above. The third aspect of the invention can further improve the optical limit of the angular resolution of the laser radar in the vertical direction and improve the ranging performance.

According to a preferred embodiment of the present invention, the lidar may further comprise a transmitting lens, located downstream of the laser transmitter plate assembly, for further modulating, e.g. changing the convergence and/or direction, the laser beam emitted by the laser transmitter plate assembly.

Fig. 12 shows a method 50 of packaging a laser according to a fourth aspect of the invention. The method 50 includes the following steps.

In step S501, a substrate is provided or prepared. The substrate may typically be made of a material, such as silicon (preferably high resistivity silicon), which enables precise control of the depth of the process by etching or chemical etching processes.

In step S502, a positioning portion is formed on the substrate by etching or chemical etching. The positioning portion is, for example, in the form of a V-groove, a U-groove, a step, or a combination thereof.

In step S503, a laser chip is mounted on the silicon substrate. During mounting, it may be necessary to couple the laser chip to electrodes of the substrate in order to provide the laser chip with a driving voltage.

In step S504, a laser beam shaping element is positioned on the substrate by using the positioning portion such that a light emitting surface of the laser chip is opposite to the laser beam shaping element. For example, the precise positioning position of the laser beam shaping element is found by the positioning portion. The locating portion may be configured to directly secure the laser beam shaping element in place. Or alternatively, the laser beam shaping element may be positioned thereon by means of bonding or the like after the positioning.

Preferably, the packaging method 50 further includes: the center of the laser beam shaping element 13 is made equal in height to the center of the light emitting surface 121 of the laser chip 12.

According to a preferred embodiment of the present disclosure, the laser chip is, for example, an edge-emitting type, and a light-emitting surface thereof has a slow axis direction and a fast axis direction, wherein the slow axis direction is parallel to an extending direction of the laser beam shaping element, and the laser beam shaping element is a fast axis compression element configured to compress a divergence angle of laser light emitted from the light-emitting surface in the fast axis direction.

The limit of the vertical angular resolution of the laser emitting plate assembly (limited only by the dimension of the fast axis) can be greatly improved. The method can realize the accurate fast axis compression when the light emitting surface of the chip is turned by 90 degrees. Materials such as silicon and the like can accurately control the processing depth and size by utilizing an etching process, a base with accurate pattern size is prepared, the fast axis divergence angle and the light beam directivity after compression are effectively controlled, and the distance measuring performance is improved. And the light emitting surface of the chip is turned over by 90 degrees, so that the measurement errors of a ground lane line, a pedestrian line and a far ground can be reduced.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A packaged laser comprising:

the device comprises a substrate, a positioning part and a positioning part, wherein the substrate is provided with the positioning part;

the laser chip is of an edge emitting type and is arranged on the substrate, and the laser chip is provided with a light emitting surface which is provided with a slow axis direction and a fast axis direction;

the laser beam shaping element is positioned by the positioning part and is opposite to the light emitting surface of the laser chip, wherein the slow axis direction is parallel to the extending direction of the laser beam shaping element; and

an electrode disposed on the substrate, the electrode configured to power the laser chip,

wherein the electrode includes positive electrode and negative electrode by the spaced apart portion, and wherein a plurality of the laser welding is on the circuit board, the laser configuration be with the orientation welding of the slow axis direction perpendicular to circuit board of light emitting area is on the circuit board, a plurality of on the circuit board the light emitting area of the laser chip in the laser staggers each other in the fast axis direction.

2. The laser of claim 1, wherein the positioning portion comprises one or more of a V-groove, a U-groove, a step.

3. The laser according to claim 1 or 2, wherein the laser beam shaping element comprises one or more of an optical fiber, a cylindrical lens, a D-lens or an aspherical mirror.

4. The laser according to claim 1 or 2, wherein the laser beam shaping element is a fast axis compression element configured to compress a divergence angle of the laser light emitted from the light emitting face in the fast axis direction.

5. The laser according to claim 1 or 2, wherein the substrate is a silicon base, and the positioning portion is formed on the silicon base by an etching process.

6. The laser according to claim 1, wherein the positive and negative electrodes are both disposed on a same surface of a substrate as the laser chip and on a side of the substrate perpendicular to the light emitting face.

7. The laser according to claim 1 or 2, wherein the center of the laser beam shaping element is level with the center of the light emitting face of the laser chip.

8. A laser emitter board assembly comprising:

a circuit board;

a plurality of lasers as claimed in any one of claims 1 to 7 arranged on said circuit board with the light emitting faces of the laser chips of the lasers facing in the same direction.

9. The laser emitter plate assembly of claim 8, wherein the plurality of lasers are soldered on the circuit board and a slow axis direction of light emitting faces of the plurality of lasers is perpendicular to the circuit board.

10. The laser transmitter board assembly of claim 8 or 9, wherein the laser transmitter board assembly comprises a plurality of said circuit boards, each circuit board having a plurality of said lasers disposed thereon, wherein the light emitting faces of the laser chips in the lasers on the plurality of circuit boards are staggered from each other in the fast axis direction.

11. A lidar comprising a laser transmitter plate assembly according to any of claims 8-10.

12. A method of packaging a laser as claimed in any of claims 1 to 7, comprising:

providing or preparing a substrate;

forming a positioning part on the substrate through etching or chemical corrosion;

mounting a laser chip on the substrate;

and positioning a laser beam shaping element on the substrate by using the positioning part, so that a light emitting surface of the laser chip is opposite to the laser beam shaping element.

13. The method of claim 12, wherein the laser chip is of an edge-emitting type, the light emitting face having a slow axis direction and a fast axis direction, wherein the slow axis direction is parallel to an extension direction of the laser beam shaping element, the laser beam shaping element being a fast axis compression element configured to compress a divergence angle of the laser light emitted from the light emitting face in the fast axis direction.

14. The method of claim 12 or 13, wherein the substrate is a silicon substrate.

15. The method of claim 12 or 13, further comprising making the center of the laser beam shaping element level with the center of the light emitting face of the laser chip.