Multi-chip laser packaging assembly

Abstract

The invention discloses a multi-chip laser packaging assembly, and belongs to the technical field of photoelectricity. The multi-chip laser packaging assembly comprises a bottom plate, a plurality of light-emitting chips arranged in rows and columns are attached to the bottom plate, and the light-emitting chips emit multi-color laser beams and have the slow axis direction and the fast axis direction. The collimating lens group comprises a plurality of collimating lenses arranged in rows and columns, the slow axis direction of the laser beam is parallel to the row direction of the plurality of light-emitting chips, and the fast axis direction of the laser beam is parallel to the column direction of the plurality of light-emitting chips; the collimating lens is a free-form surface lens, and the curvature radius of the collimating lens in the row direction is different from the curvature radius of the collimating lens in the column direction. The multi-chip laser packaging assembly solves the problem that the collimation performance of multi-color laser emitted by the multi-chip laser packaging assembly is poor.

Description

[0001] This application is based on Chinese Invention Application 202010961002.2 (2020-9-14), Invention Name: Multi-chip Laser Package Assembly. TECHNICAL FIELD

[0002] The present application relates to the field of optoelectronic technology, in particular to a multi-chip laser package assembly. BACKGROUND

[0003] With the development of optoelectronic technology, multi-chip laser package assemblies are widely used.

[0004] In the related art, Figure 1 a multi-chip laser package assembly is shown, Figure 2 a light-emitting chip light-emitting characteristic diagram is shown.

[0005] As Figure 1 shown, the multi-chip laser package assembly includes a bottom plate 1011, a tube shell 102, the bottom plate 1011 and the tube shell 102 form an accommodating space, a plurality of light-emitting chips 103 and reflecting prisms 104 are arranged on the bottom plate 1011, and a collimating lens group 105 is arranged above the tube shell 102.

[0006] The collimating lens group 005 includes a plurality of integrally formed convex lenses 1052, the plurality of convex lenses 1052 are arranged on the body 1051, and the edge of the body 1051 is fixedly connected with the position of the plurality of light-emitting chips by bonding. In this way, each convex lens in the collimating lens group 105 can correspond to a light-emitting chip Figure 2 A light-emitting chip light-emitting propagation direction diagram is shown. As Figure 2As shown, the divergence angle a of the light beam emitted by the light emitting chip 103 along the fast axis direction (i.e. the direction X in the figure) is generally large and much larger than the divergence angle b along the slow axis direction (i.e. the direction Y in the figure, which is perpendicular to the direction X). In particular, the divergence angle a of the red laser light beam emitted by the light emitting chip along the fast axis direction can reach more than 68.2°, while the divergence angle b along the slow axis direction is only about 8°. Thus, when the red light beam emitted by the light emitting chip 103 enters the convex lens 1052, the width of the light beam along the fast axis direction is large and the width of the light beam along the slow axis direction is small. After collimation by the convex lens 1052, the width of the light beam along the fast axis direction is large and the width of the light beam along the slow axis direction is small. The maximum cross-sectional width of the light beam output by a single multi-chip laser package assembly is large, and the maximum cross-sectional width of the light beam output by a light source assembly comprising a plurality of the above assemblies is large. The cross-section of the light beam is an ellipse with a large major axis and a small minor axis. Thus, in order to realize the transmission of the light beam with a large maximum cross-sectional width, the size of some optical elements in the subsequent optical path assembly of the above laser assembly needs to be designed to be large, which is not conducive to the miniaturization design of the optical path assembly and the main housing accommodating the optical path assembly.

[0007] It can be seen that the collimation effect of the collimation lens on the laser beam is poor in the related art. SUMMARY

[0008] The present application provides a multi-chip laser package assembly, which can solve the problem of poor collimation of the laser emitted by the multi-chip laser package assembly. The technical solution is as follows: the multi-chip laser package assembly comprises: a bottom plate, a plurality of light emitting chips arranged in rows and columns are mounted on the bottom plate; a tube shell, one side of the tube shell is open and encloses the bottom plate to form a containing space; a plurality of light emitting chips emit laser beams, which have a slow axis direction and a fast axis direction; a collimation lens group is arranged above the tube shell; The collimation lens group comprises a plurality of collimation lenses arranged in rows and columns, and the collimation lenses are used to reduce the divergence angle of the laser beam along the slow axis to a smaller extent than the divergence angle along the fast axis.

[0009] The technical solution provided by the present application has at least the following beneficial effects: The multi-chip laser package assembly provided in the application is characterized in that each light-emitting chip emits laser light to the corresponding collimating lens, and the collimating lens can reduce the divergence angle of the laser light to collimate the laser light. Since the divergence angle of the laser light in the fast axis is greater than that in the slow axis, each convex arc surface in the collimating lens set in the related art is a part of a spherical surface, so the collimating effect of each convex arc surface on the laser light in the fast axis and the slow axis is the same, and the difference between the divergence angles of the laser light passing through the collimating lens in the fast axis and the slow axis is still large. In the embodiment of the application, the collimating lens can make the divergence angle of the laser light entering the collimating lens in the slow axis decrease by a smaller amount than that in the fast axis after the laser light passes through the collimating lens, so the difference between the divergence angles of the laser light in the fast axis and the slow axis can be reduced after the laser light passes through the collimating lens in the application, and the collimating effect of the laser light emitted by the multi-chip laser package assembly as a whole is improved. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0011] Figure 1 is a structural schematic diagram of a multi-chip laser package assembly provided by the related art; Figure 2 is a schematic diagram of the light-emitting beam of a light-emitting chip in the related art; Figure 3 is a structural schematic diagram of a multi-chip laser package assembly provided by an embodiment of the application; Figure 4 is a structural schematic diagram of another multi-chip laser package assembly provided by an embodiment of the application; Figure 5 is a structural schematic diagram of a collimating lens provided by an embodiment of the application; Figure 6 is a schematic diagram of the light path transmission of laser light entering a collimating lens in the slow axis provided by an embodiment of the application; Figure 7 is a schematic diagram of the light path transmission of laser light entering a collimating lens in the fast axis provided by an embodiment of the application; Figure 8 is a structural schematic diagram of a collimating lens set provided by an embodiment of the application; Figure 9 is a structural schematic diagram of another collimating lens set provided by an embodiment of the application; Figure 10 is a structural schematic diagram of still another collimating lens set provided by an embodiment of the application; Figure 11 This is a schematic diagram of another collimating lens assembly provided in the embodiments of this application; Figure 12 This is a top view of a collimating lens assembly provided in an embodiment of this application. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0013] With the development of optoelectronic technology, the application of multi-chip laser packaging components is becoming increasingly widespread. For example, multi-chip laser packaging components can be used in welding and cutting processes, where high-energy lasers are required. The collimation effect of the emitted laser significantly affects its energy; better collimation results in higher energy. Multi-chip laser packaging components can also be used as light sources in laser projectors or laser TVs. In this case, the collimation effect significantly affects the brightness; better collimation results in higher brightness, leading to better display effects. The following embodiments of this application provide a multi-chip laser packaging component that can improve the collimation of the emitted laser.

[0014] Figure 3 This is a schematic diagram of the structure of a multi-chip laser packaging component provided in an embodiment of this application. Figure 3 As shown, the multi-chip laser packaging assembly 10 may include: a base plate 1011, a housing 1012, multiple light-emitting chips 102, a sealing cover plate 103, a light-transmitting sealing layer 104, and a collimating lens group 105.

[0015] In this example assembly, multiple light-emitting chips 102 are mounted on a base plate 1011 in rows and columns. Multiple reflective chips 102 emit laser beams along a plane parallel to the base plate 1011, and after the optical path is deflected by a reflector (not shown in the figure), they are emitted in a direction away from the base plate 1011, that is, from the opening of the space enclosed by the base plate 1011 and the casing 1012.

[0016] The shell 1012 is a sidewall perpendicular to the base plate 1011.

[0017] The collimating lens assembly 105 is positioned above the housing 1012 and is fixedly connected to the housing 1012 by adhesive bonding.

[0018] The plurality of light-emitting chips 102 are located in the accommodating space formed by the base plate 1011 and the housing 1012. The sealing cover 103 is annular, and the outer edge of the sealing cover 103 is fixed to the side where the opening of the base plate 1011 is located. The edge of the light-transmitting sealing layer 104 is fixed to the inner edge of the sealing cover 103. The edge of the collimating lens assembly 105 is fixed to the outer edge of the sealing cover 103 away from the surface of the base plate 1011. Optionally, the edge of the collimating lens assembly 105 can be bonded to the outer edge of the sealing cover by an adhesive, which may include glass melt adhesive, low-temperature glass solder, epoxy adhesive or other glues.

[0019] The collimating lens group 105 includes multiple collimating lenses T corresponding one-to-one with the plurality of light-emitting chips 102. Each light-emitting chip 102 emits laser light into its corresponding collimating lens T. The collimating lens T reduces the divergence angle of the incident laser light, ensuring that the reduction in divergence angle on the slow axis is less than the reduction in divergence angle on the fast axis. In other words, the collimating lens provides weaker collimation on the slow axis than on the fast axis. Optionally, the collimating lens can be made of glass.

[0020] In this example, the collimating lens group 105 also includes a plurality of collimating lenses arranged in rows and columns to reduce the difference between the divergence angle of the laser beam on the slow axis and the divergence angle on the fast axis, thereby reducing the ratio of the divergence angles.

[0021] In this example, the slow axis of the laser beam emitted by the light-emitting chip 102 is parallel to the row direction of the light-emitting chip, or in other words, it diverges outward along the row direction. The fast axis of the laser beam is parallel to the column direction of the light-emitting chip 102, or in other words, it diverges outward along the column direction.

[0022] In this example, multiple collimating lenses are also arranged in rows and columns, such as... Figure 12 As shown, the collimating lens group consists of 4 rows and 5 columns of collimating lenses. In the row direction of the collimating lens group, the vertex distance between two adjacent rows is greater than the vertex distance between two adjacent columns, as shown in the column direction. Figure 12 The distance D2 between adjacent rows is greater than the distance D1 between adjacent columns.

[0023] See again in one example. Figure 12 The collimating lenses in the outermost two columns of the collimating lens group have a width in the row direction that is greater than the width in the row direction of the collimating lenses in the other columns of the collimating lens group, such as... Figure 12 As shown, the width L2 of the outermost collimating lens column is greater than the width L1 of the collimating lens column in the middle column.

[0024] In one example, the collimating lenses in different rows or columns of the collimating lens group can be different, meaning that the collimating lenses in different rows have different curvatures in the row or column direction.

[0025] Furthermore, in this example, the curvature of the collimating lens of the collimating lens group 105 is different in the row direction and in the column direction, resulting in different changes in the divergence angle of the incident laser beam in the slow axis direction and the fast axis direction.

[0026] It should be noted that the divergence angle of the laser emitted by the light-emitting chip on the fast axis is greater than that on the slow axis, and the difference between the divergence angles on the fast and slow axes is significant. For example, the divergence angle of the laser emitted by the light-emitting chip on the fast axis ranges from 25 to 35 degrees, while the divergence angle on the slow axis ranges from 5 to 7 degrees. In related technologies, the collimating lens in the collimating lens group includes two opposing surfaces, one of which is a plane, and the other has a convex arc surface. The collimating lens can collimate the incident laser through the action of the convex arc surface. However, in related technologies, this convex arc surface is a part of a sphere, and the curvature in all directions of the convex arc surface is equal. Therefore, the collimation effect of the convex arc surface on the incident laser is the same on both the fast and slow axes. The difference in the divergence angle of the laser passing through the collimating lens on the fast and slow axes is still significant, resulting in poor collimation of the laser emitted from the multi-chip laser package assembly. It should be noted that collimating light is the same as converging light, which reduces the divergence angle of the light and makes it closer to parallel light.

[0027] In the multi-chip laser packaging assembly provided in this application embodiment, each collimating lens in the collimating lens group can reduce the divergence angle of the incident laser on the slow axis by less than the reduction in the divergence angle on the fast axis after passing through the collimating lens. That is, the collimating effect of the collimating lens on the laser on the slow axis is weaker than that on the fast axis. Therefore, in this application, the difference between the divergence angles on the fast and slow axes can be reduced after the laser passes through the collimating lens, thereby improving the overall collimation effect of the laser emitted from the multi-chip laser packaging assembly.

[0028] In summary, in the multi-chip laser packaging assembly provided in this application embodiment, after each light-emitting chip emits laser light to its corresponding collimating lens, the collimating lens can reduce the divergence angle of the laser light to collimate it. Since the divergence angle of the laser light on the fast axis is greater than that on the slow axis, the collimating lens in this application embodiment can ensure that the reduction in the divergence angle on the slow axis after passing through the collimating lens is less than the reduction in the divergence angle on the fast axis. Therefore, in this application, the difference in divergence angle between the fast and slow axes can be reduced after the laser light passes through the collimating lens, improving the overall collimation effect of the laser light emitted from the multi-chip laser packaging assembly.

[0029] In this embodiment, the collimating lens in the collimating lens group can make the reduction of the divergence angle of the incident laser on the slow axis less than the reduction of the divergence angle on the fast axis in a variety of ways. Two of these methods are explained below as examples.

[0030] In the first alternative implementation of the collimating lens Figure 5 This is a schematic diagram of the structure of a collimating lens provided in an embodiment of this application. Figure 5 As shown, the collimating lens is cylindrical and has a first surface D1 and a second surface D2. The first surface D1 and the second surface D2 are opposite surfaces of the collimating lens, with the first surface D1 closer to the sealing cover plate than the second surface D2. The first surface D1 has a concave arc surface, and the second surface D2 has a convex arc surface. The radius of curvature of the concave arc surface on the slow axis of the incident laser is smaller than its radius of curvature on the fast axis; the curvature of the arc surface is the reciprocal of its radius of curvature, therefore the curvature of the concave arc surface on the slow axis of the incident laser is greater than its curvature on the fast axis. In this embodiment, the first surface D1 is a concave arc surface and the second surface D2 is a convex arc surface, with the convex arc surface facing outwards along the laser beam emission direction, meaning the concave arc surface includes the entire area of ​​the first surface, and the convex arc surface includes the entire area of ​​the second surface. Optionally, only a portion of the first surface may be a concave arc surface, and only a portion of the second surface may be a convex arc surface; this embodiment does not impose limitations.

[0031] It should be noted that the concave surface of the lens has a diffusing effect on the incident light. The larger the radius of curvature of the concave surface, the smaller its curvature, and consequently, the weaker its diffusing effect on the light, resulting in a smaller diffusion of the light's divergence angle. In the embodiments of this application, the radius of curvature of the concave surface of the collimating lens on the slow axis of the incident laser is smaller than its radius of curvature on the fast axis. Therefore, after the laser emitted by the light-emitting chip passes through the concave surface of the collimating lens, the diffusion of the laser's divergence angle on the fast axis is less than that on the slow axis. Since the laser emitted by the light-emitting chip originally has a larger divergence angle on the fast axis than on the slow axis, the difference between the divergence angle on the slow axis and the divergence angle on the fast axis after passing through the concave surface of the collimating lens is relatively small. Compared to the divergence angle after entering the collimating lens in the prior art, in the embodiments of this application, after the laser passes through the concave arc surface, the divergence angle of the laser on the fast axis can be increased by 1.1 degrees to 1.5 degrees, and the divergence angle of the laser on the slow axis can be increased by 1.5 degrees to 2.5 degrees, thus reducing the angle difference between the laser on the fast axis and the slow axis.

[0032] For example, the concave surface of the collimating lens can be a cylinder, and the generatrix of this cylinder is parallel to the fast axis of the laser beam incident on the concave surface. It should be noted that a cylinder is a surface formed by moving a straight line parallel to a fixed curve; this moving line is called the generatrix of the cylinder. For instance, if the cylinder can be a portion of the side surface of a cylinder, the generatrix of this cylinder is parallel to the height direction of the cylinder. In the case where the concave surface of the collimating lens is a cylinder, the curvature of this concave surface on the fast axis of the incident laser is 0, and the radius of curvature is infinitely large; the curvature of this concave surface on the slow axis of the incident laser is greater than 0. Thus, on the fast axis of the laser incident on the concave surface, the concave surface is approximately flat, and the change in the divergence angle of the laser incident on the fast axis is similar to the change in the divergence angle of the laser incident on the flat glass; while on the slow axis of the laser incident on the concave surface, the curvature of the concave surface is greater, and the diffusion of the laser divergence angle on the slow axis is greater.

[0033] After the laser light incident on the collimating lens has its divergence angles on the fast and slow axes adjusted by the concave surface of the collimating lens, it can exit through the convex surface of the collimating lens. This convex surface further collimates the incident laser light, thus ensuring good collimation of the laser light exiting the collimating lens. It should be noted that the convex surface of the lens has a converging effect on the incident light rays, and a larger radius of curvature indicates a smaller degree of curvature, resulting in a weaker converging effect and a smaller reduction in the divergence angle.

[0034] In one alternative implementation of the convex arc surface of the collimating lens, the curvature of the convex arc surface is the same on both the slow and fast axes of the incident laser, such as a portion of a sphere. Since the concave arc surface of the collimating lens already minimizes the difference in divergence angles on the fast and slow axes of the laser, the convex arc surface can collimate the laser as a whole, ensuring that the reduction in the divergence angle on the fast axis is similar to the reduction in the divergence angle on the slow axis. This eliminates the need for different curvature designs in different directions of the convex arc surface, simplifying the collimating lens fabrication process.

[0035] In another alternative implementation of the convex surface of the collimating lens, the radius of curvature of the convex surface of the collimating lens on the slow axis of the incident laser beam, or in other words, the radius of curvature of the collimating lens group in the row direction, differs from that on the fast axis, or in other words, the radius of curvature of the collimating lens group in the row direction. In a specific embodiment, the radius of curvature of the convex surface of the collimating lens in the row direction of the collimating lens group is greater than that in the column direction. This allows the convex surface to further adjust the divergence angles of the incident laser on the fast and slow axes, making the reduction in the divergence angle on the fast axis greater than that on the slow axis, thereby further reducing the difference in the divergence angles of the laser emitted from the collimating lens on the fast and slow axes.

[0036] In this embodiment, the radius of curvature of the concave surface in the collimating lens can be greater than the radius of curvature of the convex surface, such as the ratio of the radius of curvature of the concave surface to that of the convex surface being in the range of 1.5 to 4. For example, the concave surface in the collimating lens bends only along the slow axis of the incident laser; therefore, the radius of curvature of the concave surface can refer to its radius of curvature along that slow axis. The ratio of the radius of curvature of the concave surface along the slow axis of the incident laser to that of the convex surface along both the slow and fast axes can be in the range of 1.5 to 4. Optionally, the radius of curvature of the concave surface along both the fast and slow axes of the incident laser can be greater than that of the convex surface along both the fast and slow axes. This ensures that the collimating lens as a whole is used for collimating and converging light, that is, the divergence angle of the laser exiting the collimating lens is smaller than the divergence angle of the laser entering the collimating lens. For example, the focal length of the collimating lens as a whole can be greater than 0, which is f = 1 / R2 - 1 / R1, where R2 represents the radius of curvature of the convex surface in the collimating lens, and R1 represents the radius of curvature of the concave surface in the collimating lens.

[0037] In the second alternative implementation of the collimating lens Figure 6 This is a schematic diagram of the optical path transmission of a laser beam incident on a collimating lens along the slow axis, provided in an embodiment of this application. Figure 7 This is a schematic diagram of the optical path transmission of a laser beam incident on a collimating lens along the fast axis, provided in an embodiment of this application. Figure 6 and 7 As shown, the first surface D1 of the collimating lens is a plane, and the second surface D2 of the collimating lens has a convex arc surface; the radius of curvature of this convex arc surface on the slow axis of the incident laser is greater than its radius of curvature on the fast axis, as shown... Figure 6 The radius of curvature of the convex surface is greater than Figure 7 The radius of curvature of the convex surface. In this optional implementation, the collimating lens can be called a freeform lens, and the convex surface in the collimating lens can be similar to a portion of the surface of a rugby ball. Optionally, the convex surface satisfies the following: the radius of curvature on the slow axis of the incident laser is in the range of 3.5 mm to 4 mm, and / or, the radius of curvature on the fast axis of the incident laser is in the range of 3.1 mm to 3.3 mm. For example, the radius of curvature of the convex surface on the fast axis of the incident laser can be 3.282 mm.

[0038] It should be noted that the smaller the radius of curvature of the convex surface, the greater the curvature of the convex surface, and the better the focusing effect of the convex surface on the laser. In this embodiment, since the first surface of the collimating lens is a plane, the degree of change in the divergence angle of the incident laser on the slow axis is the same as the degree of change in the divergence angle on the fast axis. After the laser enters the first surface of the collimating lens, the difference between the divergence angle of the laser on the fast axis and the divergence angle on the slow axis is still large. Therefore, the difference between the divergence angle of the laser incident on the convex surface of the collimating lens on the fast axis and the divergence angle on the slow axis is still large. Since the radius of curvature of the convex surface of the collimating lens on the slow axis of the incident laser is greater than the radius of curvature on the fast axis, the focusing effect of the convex surface on the incident laser on the fast axis is stronger than the focusing effect on the slow axis, thereby reducing the difference in the divergence angle of the laser emitted from the collimating lens (that is, the laser emitted from the convex surface) on the fast axis and the slow axis.

[0039] The following explanation, with reference to the accompanying diagram, details two possible implementation methods for the alignment lens group: In one possible implementation of the collimating lens group Figure 8 This is a schematic diagram of a collimating lens assembly provided in an embodiment of this application. Figure 9 This is a schematic diagram of another collimating lens assembly provided in an embodiment of this application. Figure 10 This is a schematic diagram of another collimating lens assembly provided in an embodiment of this application. Figure 9 and Figure 10 All can be Figure 8 The collimating lens assembly shown is a right view. The collimating lens assembly 105 can be integrally formed. The collimating lens assembly 105 can have an incident light surface M1 and an exit light surface M2, which are two opposing surfaces in the collimating lens assembly 105. The incident light surface M1 is closer to the sealing cover plate 103 than the exit light surface M2. The incident light surface M1 of the collimating lens assembly 105 includes the first surface D1 of each collimating lens in the collimating lens assembly 105, and the exit light surface M2 includes the second surface D2 of each collimating lens. In the first optional implementation of the collimating lens described above, such as... Figure 9 As shown, the incident surface M1 of the collimating lens group 105 has multiple concave arc surfaces, and the exit surface M2 of the collimating lens group 105 has multiple convex arc surfaces. Each concave arc surface and its corresponding convex arc surface constitute a collimating lens T. Optionally, the orthographic projection of each convex arc surface onto the incident surface of the collimating lens group 105 can coincide with the orthographic projection of the corresponding convex arc surface onto that incident surface. In the second optional implementation of the collimating lens described above, as... Figure 10 As shown, the incident surface of the collimating lens group 105 is a plane, and the exit surface M2 of the collimating lens group 105 has multiple convex arc surfaces. Each part of the collimating lens group 105 containing a convex arc surface is a collimating lens T.

[0040] In another alternative implementation of the collimating lens group Figure 11 This is a schematic diagram of another collimating lens assembly provided in an embodiment of this application. For example... Figure 11 As shown, the collimating lens group 105 can also be composed of multiple independent collimating lenses T. For example, the multi-chip laser packaging assembly can also include a support frame K, the edge of which can be fixed to the outer edge of the sealing cover away from the surface of the housing. The support frame can have multiple hollow areas (not shown in the figure), and each collimating lens in the collimating lens group can cover one of these hollow areas. These hollow areas can correspond one-to-one with multiple light-emitting chips in the multi-chip laser packaging assembly, and the laser emitted from each light-emitting chip can pass through the corresponding hollow area and be directed towards the collimating lens covering that hollow area.

[0041] In this embodiment, the multi-chip laser package 10 can be a multi-chip laser diode (MCL) type multi-chip laser package. Multiple light-emitting chips in this multi-chip laser package can be arranged in multiple rows and columns within the package. This multi-chip laser package can be a monochromatic MCL multi-chip laser package or a multi-color MCL multi-chip laser package. In a monochromatic MCL multi-chip laser package, each light-emitting chip emits light of the same color. In a multi-color MCL multi-chip laser package, multiple light-emitting chips 102 can include various types of light-emitting chips, each emitting a different color of light. In this embodiment, taking a multi-color MCL multi-chip laser package as an example, the multiple light-emitting chips 102 in the multi-chip laser package can include a first light-emitting chip for emitting a first color of laser light and a second light-emitting chip for emitting a second color of laser light. The divergence angle of the first color of laser light is smaller than that of the second color of laser light. The collimating lens group 105 can satisfy the following: the reduction in the divergence angle of the incident laser by the collimating lens corresponding to the first light-emitting chip is less than the reduction in the divergence angle of the incident laser by the collimating lens corresponding to the second light-emitting chip.

[0042] For example, the first color may include blue and green, and the first light-emitting chip may include a blue light-emitting chip and a green light-emitting chip; the second color may be red, and the second light-emitting chip may be a red light-emitting chip. The divergence angle of the red laser emitted by the red light-emitting chip may be greater than the divergence angle of the blue laser emitted by the blue light-emitting chip, and greater than the divergence angle of the green laser emitted by the green light-emitting chip.

[0043] Optionally, the divergence angles of the red laser on both the fast and slow axes can be greater than those of the green and blue lasers on the same axes. Alternatively, the divergence angle of the red laser on the fast axis can be greater than that of the green and blue lasers on the fast axis, and the divergence angle of the red laser on the slow axis can also be greater than that of the green and blue lasers on the slow axis, but the divergence angle of the red laser on the slow axis can be smaller than that of the blue and green lasers on the fast axis. Based on the magnitudes of the divergence angles of the red, blue, and green lasers on the fast and slow axes, the reduction in the divergence angle of the laser emitted by the collimating lens corresponding to each color of laser can be adjusted accordingly, such as by adjusting the radius of curvature of the convex surface of the collimating lens on the fast and slow axes.

[0044] For example, the divergence angle of the red laser on the fast axis of the input laser is greater than that of the blue laser on the fast axis, and the divergence angle of the blue laser on the fast axis is greater than that of the red laser on the slow axis. In this case, if the collimating lens in the collimating lens group adopts the first feasible method described above, the radius of curvature of the concave surface of the collimating lens towards which the blue laser is directed on the slow axis can be greater than the radius of curvature of the concave surface of the collimating lens towards which the red laser is directed on the slow axis, but smaller than the radius of curvature of the concave surface of the collimating lens towards which the red laser is directed on the fast axis. If the collimating lens in the collimating lens group adopts the second feasible method described above, the radius of curvature of the convex surface of the collimating lens towards which the blue laser is directed on the fast axis can be greater than the radius of curvature of the convex surface of the collimating lens towards which the red laser is directed on the fast axis, but smaller than the radius of curvature of the convex surface of the collimating lens towards which the red laser is directed on the slow axis. Other relationships between the divergence angles of lasers of various colors can be deduced similarly, and will not be elaborated further in this embodiment.

[0045] In this embodiment, the red light-emitting chip in the multi-chip laser packaging assembly can contain multiple light-emitting points, and the size of the red laser spot emitted by each red light-emitting chip on the fast axis can reach 350 micrometers. The blue and green light-emitting chips can each contain only one light-emitting point, and the size of the laser spot emitted by the blue and green light-emitting chips on the fast axis can be around 35 micrometers, while the size of the laser spot emitted by each chip on the slow axis is around 1 micrometer. Thus, the laser spot emitted by each light-emitting chip in the multi-chip laser packaging assembly is elongated and flat. After the laser is collimated by a collimating lens, the aspect ratio of the resulting spot can be reduced.

[0046] The following describes the housing, light-emitting chip, and sealing cover plate in the multi-chip laser packaging assembly of this application embodiment: Please continue to refer to this. Figure 3The base plate 1011 may include a base plate 10111 and an annular tube shell 1012 fixed to the base plate 10111. The base plate 10111 and the tube shell 1012 enclose a receiving space for the base plate 1011. The opening in the tube shell 1012 away from the base plate 10111 is the opening of the base plate 1011. Optionally, the base plate 10111 and the tube shell 1012 in the base plate 1011 can be an integral structure, or they can be independent structures, formed by welding them together to form the base plate 1011.

[0047] The thickness of the outer edge of the sealing cover 103 can be less than a preset thickness threshold. This thinner outer edge can be fixed to the side of the opening in the base plate 1011 using parallel welding technology. Alternatively, the outer edge of the sealing cover 103 can be fixed to the surface of the tube shell 1012 away from the base plate 10111 using parallel welding technology. Optionally, the sealing cover 103 can be a sheet metal part, with the same or approximately the same thickness at all locations. The inner edge of the sealing cover 103 can be recessed relative to the outer edge towards the base plate 10111. The sealing cover 103 can be manufactured using sheet metal processes, such as stamping an annular plate structure, causing appropriate bending, recessing, or protrusion at suitable locations within the plate structure to obtain the sealing cover provided in this embodiment.

[0048] The light-transmitting sealing layer 104 can be a plate-like structure. This plate-like structure may include two parallel, larger surfaces and multiple smaller side surfaces connecting the two surfaces. The side surfaces of the light-transmitting sealing layer 104 can be fixed to the inner edge of the sealing cover plate 103 using sealant. In this embodiment, the light-transmitting sealing layer can be directly fixed to the sealing cover plate, or the multi-chip laser packaging assembly may further include a support frame for supporting the light-transmitting sealing layer. The light-transmitting sealing layer can be first fixed to the support frame, and then the support frame can be fixed to the sealing cover plate. For example, the support frame can be a rectangular frame, so that the middle area of ​​the light-transmitting sealing layer can be supported by the support frame, thereby improving the installation firmness of the light-transmitting sealing layer. Optionally, at least one of the surfaces of the light-transmitting sealing layer near the base plate and the surface away from the base plate may also be covered with a brightness enhancement film to improve the light output brightness of the multi-chip laser packaging assembly.

[0049] The light-emitting chip 102 may include a light-emitting chip, a heat sink, and a reflecting prism (not illustrated separately in this embodiment). The heat sink may be disposed on the bottom plate of the housing, and the light-emitting chip may be disposed on the heat sink, which is used to assist in heat dissipation of the light-emitting chip. The reflecting prism may be located on the light-emitting side of the light-emitting chip. The light emitted by the light-emitting chip can be directed towards the reflecting prism, and then reflected by the reflecting prism to pass through the light-transmitting sealing layer and the collimating lens group before being emitted.

[0050] In this embodiment, the casing material can be copper, such as oxygen-free copper; the light-transmitting sealing layer material can be glass; and the sealing cover material can be stainless steel. It should be noted that copper has a high thermal conductivity. The casing material in this embodiment is copper, which ensures that the heat generated by the light-emitting chip on the base plate of the casing during operation can be quickly conducted through the casing and dissipated, preventing heat accumulation and damage to the light-emitting chip. Optionally, the casing material can also be one or more of aluminum, aluminum nitride, and silicon carbide. The sealing cover material in this embodiment can also be other Kovar materials, such as iron-nickel-cobalt alloys or other alloys. The light-transmitting sealing layer material can also be other light-transmitting and reliable materials, such as resin materials.

[0051] The base plate 1011, the sealing cover plate 103, and the light-transmitting sealing layer 104 can form a sealed space, allowing the light-emitting chip 102 to be placed within the sealed space and preventing water and oxygen from corroding the light-emitting chip 102. Furthermore, by reducing the risk of the light-transmitting sealing layer 104 cracking due to the heat generated during the operation of the light-emitting chip 102, the sealing effect of the sealed space can be guaranteed, thereby extending the lifespan of the light-emitting chip.

[0052] In this embodiment, when fixing the outer edge of the sealing cover 103 to the base plate 1011 using parallel sealing welding technology, the sealing cover 103 is first placed on the side where the opening of the base plate 1011 is located, with the outer edge of the sealing cover 103 overlapping the surface of the tube shell 1012 of the base plate 1011 away from the base plate 1011. Then, the outer edge is heated using sealing welding equipment to melt the connection between the outer edge and the tube shell 1012, thereby welding the outer edge to the side wall of the base plate 1011. Optionally, before fixing the sealing cover 103 to the base plate 1011, the light-transmitting sealing layer 104 can be fixed to the sealing cover 103, for example, by using an adhesive to fix the edge of the light-transmitting sealing layer 104 to the inner edge of the sealing cover 103. This adhesive can cover the side surface of the light-transmitting sealing layer 104 to ensure reliable adhesion of the light-transmitting sealing layer. After fixing the sealing cover plate 103 to the base plate 1011, the collimating lens assembly 105 can be suspended in the air to adjust the collimation effect. After adjusting and determining the position of the collimating lens assembly 105, an adhesive is applied to the outer edge of the sealing cover plate 103, and then the collimating lens assembly 105 is fixed to the sealing cover plate 103 by the adhesive.

[0053] Please refer to Figure 4The base plate 1011 may have multiple openings on opposite sides of the housing 1012. The multi-chip laser package assembly 10 may also include multiple conductive pins 106, which can extend through the openings in the housing 1012 into the base plate 1011 and be fixed to the base plate 1011. The conductive pins 106 can be electrically connected to the electrodes of the light-emitting chip in the light-emitting chip 102 to transmit external power to the light-emitting chip, thereby exciting the light-emitting chip to emit light. Optionally, the aperture of the opening can be 1.2 mm, and the diameter of the conductive pin 106 can be 0.55 mm.

[0054] Optionally, in assembling the multi-chip laser packaging assembly in this embodiment, a ring-shaped solder structure (such as a ring-shaped glass bead) can be placed in an opening on the sidewall of the housing, and conductive leads can be passed through the solder structure and the opening. Then, the sidewall is placed around the perimeter of the base plate, and a ring-shaped silver-copper solder is placed between the base plate and the housing. Next, the structure of the base plate, sidewall, and conductive leads is placed in a high-temperature furnace for sealing and sintering. After sealing, sintering, and curing, the base plate, sidewall, conductive leads, and solder become a whole, thereby achieving an airtight seal at the sidewall opening. Alternatively, the light-transmitting sealing layer can be fixed to the sealing cover plate, such as by attaching the edge of the light-transmitting sealing layer to the inner edge of the sealing cover plate to obtain the top cover assembly. Then, the light-emitting chip can be soldered onto the base plate within the housing space of the housing, and then the top cover assembly is soldered onto the sidewall of the housing away from the base plate using parallel sealing technology. Finally, the collimating lens assembly is fixed to the side of the top cover assembly away from the base plate with epoxy adhesive, thus completing the assembly of the multi-chip laser packaging assembly. It should be noted that the above assembly process is only an exemplary process provided by the embodiments of this application. The welding process used in each step can be replaced by other processes, and the order of each step can also be adjusted. The embodiments of this application do not limit this.

[0055] In summary, in the multi-chip laser packaging assembly provided in this application embodiment, after each light-emitting chip emits laser light to its corresponding collimating lens, the collimating lens can reduce the divergence angle of the laser light to collimate it. Since the divergence angle of the laser light on the fast axis is greater than that on the slow axis, the collimating lens in this application embodiment can ensure that the reduction in the divergence angle on the slow axis after passing through the collimating lens is less than the reduction in the divergence angle on the fast axis. Therefore, in this application, the difference in divergence angle between the fast and slow axes can be reduced after the laser light passes through the collimating lens, improving the overall collimation effect of the laser light emitted from the multi-chip laser packaging assembly.

[0056] It should be noted that, in the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more, unless otherwise expressly defined. "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect. In the accompanying drawings, the dimensions of layers and regions may be exaggerated for clarity of illustration. It is also understood that when an element or layer is referred to as being "on" another element or layer, it can be directly on the other element, or there may be intermediate layers. Similar reference numerals throughout indicate similar elements.

[0057] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A multi-chip laser package assembly, comprising: include: A base plate on which multiple light-emitting chips are mounted in rows and columns; The shell has an opening on one side, which, together with the base plate, forms an accommodating space. Multiple light-emitting chips emit multi-color laser beams with a slow axis direction and a fast axis direction; the slow axis direction of the laser beams is parallel to the row direction of the multiple light-emitting chips, and the fast axis direction of the laser beams is parallel to the column direction of the multiple light-emitting chips. A collimating lens assembly is disposed above the tube shell and includes multiple collimating lenses arranged in rows and columns. The collimating lenses are freeform surface lenses, and the radius of curvature of the collimating lenses in the row direction is different from the radius of curvature in the column direction.

2. The multi-chip laser package assembly of claim 1, wherein, The collimating lens of the collimating lens group has a first surface and a second surface, wherein the second surface faces outward along the emission direction of the laser beam, and the second surface is at least partially a convex arc surface, and the radius of curvature of the collimating lens in the row direction is greater than the radius of curvature in the column direction.

3. The multi-chip laser package assembly of claim 1, wherein, In the row direction of the collimating lens group, the vertex distance between two adjacent rows is greater than the vertex distance between two adjacent columns in the column direction of the collimating lens group.

4. The multi-chip laser package assembly of claim 1, wherein, The collimating lenses in the two outermost columns of the collimating lens group have a width in the row direction that is greater than the width in the row direction of the collimating lenses in the other columns of the collimating lens group.

5. The multi-chip laser package assembly of claim 2, wherein, The first surface of the collimating lens is a plane, and the multi-chip laser packaging assembly also includes a sealing cover plate. The first surface is close to the sealing cover plate relative to the second surface. The sealing cover plate is annular, and the edge of the collimating lens assembly is bonded to the outer edge of the sealing cover plate by an adhesive.

6. The multi-chip laser package assembly of claim 2 or 5, wherein, The convex surface satisfies the following conditions: the radius of curvature on the slow axis is in the range of 3.5 mm to 4 mm, and / or the radius of curvature on the fast axis is in the range of 3.1 mm to 3.3 mm.

7. The multi-chip laser package assembly of claim 1, wherein, The plurality of light-emitting chips include a first light-emitting chip for emitting laser of a first color and a second light-emitting chip for emitting laser of a second color, wherein the divergence angle of the first color laser is smaller than the divergence angle of the second color laser. The reduction in the divergence angle of the incident laser by the collimating lens corresponding to the first light-emitting chip is less than the reduction in the divergence angle of the incident laser by the collimating lens corresponding to the second light-emitting chip.

8. The multi-chip laser package assembly of claim 7, wherein, The first light-emitting chip includes a blue light-emitting chip and a green light-emitting chip, and the second light-emitting chip includes a red light-emitting chip.

9. The multi-chip laser package assembly of claim 1 or 7, wherein, The collimating lenses in different rows or columns of the collimating lens group have different curvatures in the row or column directions.

10. The multi-chip laser package assembly of claim 8, wherein, The radius of curvature of the convex surface of the collimating lens of the first light-emitting chip in the fast axis direction is greater than the radius of curvature of the convex surface of the collimating lens of the second light-emitting chip in the fast axis direction, and the radius of curvature of the convex surface of the collimating lens of the first light-emitting chip in the slow axis direction is less than the radius of curvature of the convex surface of the collimating lens of the second light-emitting chip in the slow axis direction.

Images