A laser module structure and a preparation method thereof

Abstract

The present invention discloses a laser module structure and a preparation method thereof. The laser module structure includes: a substrate; at least one light-emitting unit, located on a first surface of the substrate; an adhesive layer, located on the first surface of the substrate, and at least part of the adhesive layer is arranged around the outer edge of the light-emitting unit; an optical lens is arranged in a one-to-one correspondence with the light-emitting unit, and the optical lens is fixed to the substrate through the adhesive layer; the optical lens has a cavity for accommodating the light-emitting unit; wherein the light-emitting unit includes a laser chip and a first metal pad pair connected to the laser chip; the first metal pad pair includes a first metal pad and a second metal pad; the laser chip is fixed on the surface of the first metal pad away from the substrate, and the lead of the laser chip is connected to the second metal pad; the height of the first metal pad relative to the substrate is greater than or equal to the height of the adhesive layer relative to the substrate, and the height of the adhesive layer relative to the substrate meets the preset bonding thickness, thereby reducing the volume of the device while avoiding adhesive contamination of the laser chip.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of laser technology, and in particular to a laser module structure and a manufacturing method thereof. Background Art

[0002] Semiconductor lasers, such as edge emitting lasers (EELs) and vertical cavity surface emitting lasers (VCSELs), are widely used in applications such as three-dimensional sensing, lidar, optical communications, and lighting.

[0003] Currently, the optical packaging of semiconductor laser chips such as VCSELs or EELs usually involves attaching the laser chip to a substrate, then attaching the optical lens to a dam or bracket on the substrate, or directly bonding the optical lens with UV glue. However, the dam / bracket occupies a certain volume, requiring sufficient area to be reserved on the substrate, making further compression of the semiconductor laser volume very limited. While directly bonding the optical lens with UV glue can reduce the volume, in order to reduce the risk of the UV glue debonding and causing the optical lens to fall off, the thickness of the UV glue cannot be set too small, causing the applied UV glue to easily flow onto the laser chip and contaminate the laser chip, affecting the working performance of the semiconductor laser. Therefore, how to further reduce the volume of the semiconductor laser while preventing UV glue from contaminating the laser chip has become a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The embodiment of the present invention provides a laser module structure and a preparation method thereof, which can reduce the size of the device while preventing UV glue from contaminating the laser chip and ensuring the working performance of the semiconductor laser.

[0005] According to one aspect of the present invention, a laser module structure is provided, comprising:

[0006] a substrate comprising a first surface and a second surface opposite to the first surface;

[0007] at least one light-emitting unit, wherein the light-emitting unit is located on the first surface of the substrate;

[0008] an adhesive layer, the adhesive layer being located on the first surface of the substrate, and at least a portion of the adhesive layer being disposed around an outer side of an edge of the light-emitting unit;

[0009] an optical lens provided in one-to-one correspondence with the light-emitting units, the optical lens being fixed to the substrate via the adhesive layer; the optical lens having a cavity for accommodating the light-emitting units;

[0010] In which, the light-emitting unit includes a laser chip and a first metal pad pair connected to the laser chip; the first metal pad pair includes a first metal pad and a second metal pad fixed on the first surface; the laser chip is fixed on the surface of the first metal pad away from the substrate, and the lead of the laser chip is connected to the second metal pad; the height of the first metal pad relative to the substrate is greater than or equal to the height of the adhesive layer relative to the substrate, and the height range of the adhesive layer relative to the substrate meets the thickness corresponding to the adhesive layer under the preset bonding strength.

[0011] Optionally, along the direction from the adhesive layer to the substrate, the cross-sectional area of the adhesive portion where the optical lens contacts the adhesive layer gradually decreases.

[0012] Optionally, at least one light-emitting unit further includes a sensor and a second metal pad pair connected to the sensor;

[0013] The second metal pad pair includes a third metal pad and a fourth metal pad fixed on the first surface; the sensor is fixed on the surface of the third metal pad away from the substrate, and the lead of the sensor is connected to the fourth metal pad; the height of the third metal pad relative to the substrate is greater than or equal to the height of the adhesive layer relative to the substrate.

[0014] Optionally, the second surface of the substrate further includes a pair of external metal pads correspondingly connected to each of the first metal pads, and a pair of external metal pads correspondingly connected to each of the second metal pads.

[0015] Optionally, the sensor includes a photosensor or a temperature sensor.

[0016] Optionally, the material of the substrate includes aluminum nitride, aluminum oxide or beryllium oxide; the material of the optical lens includes polycarbonate, silicone or acrylic; and the material of the adhesive layer includes silicone or epoxy resin.

[0017] According to another aspect of the present invention, a method for preparing a laser module structure is provided, which is used to form the laser module structure described in any embodiment of the present invention, comprising:

[0018] Providing a substrate connecting plate, the substrate connecting plate comprising a first surface and a second surface opposite to the first surface;

[0019] forming a plurality of first metal pad pairs arranged in an array on the first surface of the substrate connecting plate; each of the first metal pad pairs includes a first metal pad and a second metal pad fixed on the first surface;

[0020] Bonding a plurality of laser chips to the first metal pads in a one-to-one correspondence; wherein the laser chips are fixed on a surface of the first metal pad away from the substrate connecting plate, and the leads of the laser chips are connected to the second metal pads to form a light-emitting unit;

[0021] The optical lens connecting plate is manufactured by a mold injection molding or compression molding process; the optical lens connecting plate includes an optical lens corresponding to the light-emitting unit array, and the optical lens has a cavity for accommodating the light-emitting unit;

[0022] An adhesive layer is formed on the first surface of the substrate connecting plate; the adhesive layer is arranged around the outer edge of the light-emitting unit; the height of the first metal pad relative to the substrate connecting plate is greater than or equal to the height of the adhesive layer relative to the substrate connecting plate, and the height range of the adhesive layer relative to the substrate meets a preset bonding thickness;

[0023] Pressing the optical lens connecting plate onto the first surface of the substrate connecting plate and fixing it via the adhesive layer;

[0024] According to the number of light-emitting units included in the laser module structure, the semi-finished product after the optical lens connecting plate and the base plate are pressed and fixed is cut to form a single laser module structure with independent functions.

[0025] Optionally, forming an adhesive layer on the first surface of the substrate connecting plate includes:

[0026] Glue is applied on the area where the glue layer is located on the first surface of the substrate connecting plate by a glue dispenser.

[0027] Optionally, forming an adhesive layer on the first surface of the substrate connecting plate includes:

[0028] The total amount of glue required to form the glue layer is determined, and the glue of the total amount is injected into the glue injection position of the substrate connecting plate to form the glue layer based on the fluidity of the glue.

[0029] Optionally, before determining the total glue amount required to form the glue layer, injecting the glue of the total glue amount into the glue injection position of the substrate connecting plate, and forming the glue layer based on the fluidity of the glue, the method further includes:

[0030] A barrier layer is formed on the inner side of the edge of the first surface of the substrate connecting plate, and the barrier layer is used to prevent the injected glue from flowing to the back side of the substrate connecting plate.

[0031] The technical solution of the embodiment of the present invention, by raising the first metal pad on which the laser chip is provided so that the height of the first metal pad relative to the substrate is greater than or equal to the height of the formed adhesive layer relative to the substrate, avoids contamination of the chip by uncured adhesive during the preparation process of the laser module structure, thereby ensuring the working performance of the semiconductor laser; in addition, by raising the first metal pad on which the laser chip is provided, the thickness of the formed adhesive layer can be relatively raised, thereby increasing the depth of the optical lens extending into the adhesive layer, and while reducing the cross-sectional area of the end of the optical lens extending into the adhesive layer, the firmness of the optical lens fixation can be ensured, thereby further reducing the volume of the semiconductor laser.

[0032] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 is a cross-sectional view of a laser module structure provided by an embodiment of the present invention;

[0035] Figure 2 is a cross-sectional view of a laser module structure provided by an embodiment of the present invention;

[0036] Figure 3 This is a front plan view of a laser module structure provided by an embodiment of the present invention;

[0037] Figure 4 This is a back view of a laser module structure provided by an embodiment of the present invention;

[0038] Figure 5 This is a flow chart of a method for preparing a laser module structure provided by an embodiment of the present invention;

[0039] Figure 6 This is a structural diagram of a substrate-to-board connection after a laser chip is bound, provided by an embodiment of the present invention;

[0040] Figure 7 This is a flow chart of another method for preparing a laser module structure provided in the second embodiment of the present invention;

[0041] Figure 8 This is a flow chart of another method for preparing a laser module structure provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0043] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0044] The embodiment of the present invention provides a laser module structure. Figure 1 is a cross-sectional view of a laser module structure provided by an embodiment of the present invention. Figure 2 This is a cross-sectional view of a laser module structure provided by an embodiment of the present invention, referring to Figure 1 and Figure 2 , the laser module structure includes:

[0045] The substrate 10 includes a first surface and a second surface opposite to the first surface;

[0046] at least one light-emitting unit, the light-emitting unit being located on the first surface of the substrate 10;

[0047] The adhesive layer 30 is located on the first surface of the substrate 10 and is arranged around the outer edge of the light-emitting unit;

[0048] An optical lens 40 is provided in one-to-one correspondence with the light-emitting unit, and the optical lens 40 is fixed on the substrate 10 via the adhesive layer 30; the optical lens 40 has a cavity for accommodating the light-emitting unit;

[0049] The light emitting unit includes a laser chip 21 and a first metal pad pair 22 connected to the laser chip 21; the first metal pad pair 22 includes a first metal pad 221 and a second metal pad 222 fixed on the first surface; the laser chip 21 is fixed on the surface of the first metal pad 221 away from the substrate 10, and the lead of the laser chip 21 is connected to the second metal pad 222; the height of the first metal pad 221 relative to the substrate 10 is greater than (reference Figure 1 ) or equal to (reference Figure 2 ) The height of the adhesive layer 30 relative to the substrate 10, and the height range of the adhesive layer 30 relative to the substrate 10 satisfies the thickness of the adhesive layer corresponding to the preset bonding strength.

[0050] Specifically, the material of the substrate 10 may include semiconductor packaging materials such as aluminum nitride, aluminum oxide or beryllium oxide, or it may be a ceramic substrate. The use of a ceramic substrate can reduce the material cost of the laser module structure. The substrate 10 includes a first surface and a second surface opposite to the first surface, wherein at least one light-emitting unit is included on the first surface. Each light-emitting unit includes a laser chip 21 and a first metal pad pair 22 connected to the laser chip 21. The first metal pad pair 22 includes a first metal pad 221 and a second metal pad 222 fixed on the first surface; the laser chip 21 is bound to the surface of the first metal pad 221 away from the substrate 10, and the lead of the laser chip 21 is connected to the second metal pad 222. A voltage signal is provided to the laser chip 21 through the first metal pad 221 and the second metal pad 222 to drive the laser chip 21 to emit light. The number of light-emitting units in the laser module structure can be set according to actual needs, Figure 1 and Figure 2 In each case, one light-emitting unit is drawn as an example.

[0051] Each light-emitting unit is also configured with an optical lens 40, which includes two upper and lower optical interfaces, and the two optical interface surfaces are free-form surfaces. The optical lens 40 has a cavity for accommodating the light-emitting unit, and the optical lens 40 is used to adjust the direction of the light emitted by the light-emitting unit. The optical lens 40 can diverge the light emitted by the light-emitting unit, and can also converge the light emitted by the light-emitting unit. The optical lens 40 can achieve the final uniformity of the light spot and the light-emitting angle effect of the device. An adhesive layer 30 is also provided on the first surface of the substrate 10, and the optical lens 40 is fixed to the substrate 10 through the adhesive layer 30. At least part of the adhesive layer 30 is provided around the outer edge of the light-emitting unit. The material of the optical lens 40 may include polycarbonate, silicone or acrylic; the material of the adhesive layer 30 may include silicone or epoxy resin.

[0052] During the preparation of the laser module structure, the optical lens 40 can be formed by an injection molding process. The injection mold is designed and processed according to the optical requirements, and the optical lens connecting plate is mass-produced through the injection molding process. The number of optical lenses 40 of the optical lens connecting plate depends on the number of mold cavities. For example, if the mold has 486 cavities, the number of optical lenses 40 of the optical lens connecting plate formed by the injection molding process is 486. Through the injection molding process, a multi-cavity mold is customized to carry out batch array lens injection molding to improve production efficiency. Moreover, the surface shape of the optical lens 40 can be customized by a mold, which greatly reduces the material cost and development cycle of the optical lens 40 while improving product performance and application range.

[0053] After forming an adhesive layer 30 on the substrate connecting plate on which a plurality of laser chips 21 are mounted in batches, the optical lens connecting plate is pressed onto the first surface of the substrate connecting plate and the adhesive layer 30 is cured, so that the optical lens connecting plate is fixed to the substrate connecting plate. According to the number of light-emitting units included in the laser module structure, the semi-finished product after the optical lens connecting plate and the substrate connecting plate are pressed and fixed is cut to form a single laser module structure with independent functions. By fixing the optical lens connecting plate with the adhesive layer 30, compared with mounting the optical lens 40 individually on the dam / bracket on the substrate 10, the batch transfer of the optical lens 40 can be achieved, thereby improving the mounting efficiency of the optical lens 40 while reducing the volume of the module product. Through the molding packaging process, the chip-level packaging of the optical lens 40 can be achieved. In addition, the hardness of the adhesive layer 30 is relatively low, and the soft silicone can release stress, thereby improving the reliability of the packaging.

[0054] In addition, during the preparation of the laser module structure, while setting the height range of the adhesive layer 30 relative to the substrate 10 to meet the preset bonding thickness to ensure the adhesive layer 30 is firmly bonded to the optical lens 40, the first metal pad 221 on which the laser chip 21 is provided is raised to avoid contamination of the chip when applying the uncured adhesive layer 30, thereby ensuring the operating performance of the semiconductor laser. That is, after the adhesive layer 30 is cured, the height of the first metal pad 221 relative to the substrate 10 is greater than or equal to the height of the adhesive layer 30 relative to the substrate 10. By raising the first metal pad 221 on which the laser chip 21 is provided, the maximum thickness of the formed adhesive layer 30 can also be relatively raised, thereby increasing the depth of the optical lens 40 extending into the adhesive layer 30. This can reduce the cross-sectional area of the end of the optical lens 40 extending into the adhesive layer 30 while ensuring the firm fixation of the optical lens 40, thereby further reducing the volume of the semiconductor laser.

[0055] The laser module structure provided by the embodiment of the present invention fixes the optical lens through the adhesive layer, which can reduce the volume of the module product compared to mounting the optical lens on a dam / bracket on a substrate. By raising the first metal pad on which the laser chip is provided so that the height of the first metal pad relative to the substrate is greater than or equal to the height of the adhesive layer relative to the substrate, the laser module structure is prevented from being contaminated by uncured adhesive during the preparation process, thereby ensuring the working performance of the semiconductor laser. In addition, by raising the first metal pad on which the laser chip is provided, the thickness of the formed adhesive layer can be relatively raised, thereby increasing the depth of the optical lens extending into the adhesive layer. While reducing the cross-sectional area of the end of the optical lens extending into the adhesive layer, the firmness of the optical lens fixation can be ensured, thereby further reducing the volume of the semiconductor laser.

[0056] In one embodiment of the present invention, along the direction from the adhesive layer 30 to the substrate 10 , the cross-sectional area of the adhesive portion 41 where the optical lens 40 contacts the adhesive layer 30 gradually decreases.

[0057] It can be understood that the end of the optical lens 40 that contacts the adhesive layer 30 is the bonding portion 41, and the surface parallel to the substrate 10 is the cross-section of the bonding portion 41. The closer the bonding portion 41 is to the substrate 10, the smaller the cross-sectional area of the bonding portion 41. That is, the area of the bottom surface of the bonding portion 41 closest to the substrate 10 or in contact with the substrate 10 is the smallest. This can reduce the area of the substrate 10 occupied by the optical lens 40, thereby further reducing the size of the semiconductor laser. At the same time, the closer the bonding portion 41 is to the substrate 10, the smaller the cross-sectional area of the bonding portion 41. This creates a certain inclination angle between the side surface of the bonding portion 41 and the plane of the substrate 10. Compared to the case where the side surface of the bonding portion 41 is perpendicular to the plane of the substrate 10 (the cross-sectional area of the bonding portion 41 is equal along the direction from the adhesive layer 30 to the substrate 10), the area of the side surface of the bonding portion 41 can be increased, that is, the contact area between the side surface of the bonding portion 41 and the adhesive layer 30 can be increased, thereby ensuring the strong bond of the adhesive layer 30 to the optical lens 40. Along the direction of the adhesive layer 30 pointing toward the substrate 10 , the cross-sectional shape of the adhesive portion 41 where the optical lens 40 contacts the adhesive layer 30 may be an inverted trapezoid or an inverted triangle.

[0058] In one embodiment of the present invention, reference Figure 3 , at least one light emitting unit further includes a sensor 23 and a second metal pad pair 24 connected to the sensor 23;

[0059] The second metal pad pair 24 includes a third metal pad 241 and a fourth metal pad 242 fixed on the first surface; the sensor 23 is fixed on the surface of the third metal pad 241 away from the substrate 10, and the lead of the sensor 23 is connected to the fourth metal pad 242; the height of the third metal pad 241 relative to the substrate 10 is greater than or equal to the height of the adhesive layer 30 relative to the substrate 10. Figure 3 Four light-emitting units are exemplarily shown in FIG. 1 , and each light-emitting unit includes a sensor 23 and a second metal pad pair 24 connected to the sensor 23 .

[0060] It can be understood that if the laser module structure includes multiple light-emitting units, at least one light-emitting unit also includes a sensor 23 and a second metal pad pair 24 connected to the sensor 23. The second metal pad pair 24 includes a third metal pad 241 and a fourth metal pad 242 fixed to the first surface. The sensor 23 is fixed to the surface of the third metal pad 241 facing away from the substrate 10, and the leads of the sensor 23 are connected to the fourth metal pad 242. The third metal pad 241 and the fourth metal pad 242 are used to provide voltage signals for the operation of the sensor 23. The height of the third metal pad 241 on which the sensor 23 is mounted relative to the substrate 10 is greater than or equal to the height of the adhesive layer 30 relative to the substrate 10. By elevating the third metal pad 241 on which the sensor 23 is mounted so that its height relative to the substrate 10 is greater than or equal to the height of the adhesive layer 30 relative to the substrate 10, uncured adhesive during the laser module structure fabrication process is prevented from contaminating the sensor 23, thereby ensuring the operational performance of the sensor 23.

[0061] Sensor 23 can be a photosensor. When light emitted by laser chip 21 passes through the optical interface at the bottom of the lens, most of the light is refracted, while some is reflected. At this point, the photosensor receives the light signal, and the circuit of laser chip 21 remains energized. If optical lens 40 falls and no light is reflected by the photosensor, the circuit of laser chip 21 is disconnected, providing safety protection. Sensor 23 can be a temperature sensor that detects the temperature of laser chip 21. When the temperature exceeds a preset value, the circuit of laser chip 21 is disconnected, providing safety protection.

[0062] In one embodiment of the present invention, Figure 4 for Figure 3 Back view of the light emitting unit 1, see Figure 3 and Figure 4 The second surface of substrate 10 further includes an external metal pad pair 220 connected to each first metal pad pair 22, and an external metal pad pair 240 connected to each second metal pad pair 24. First metal pad 221 is connected to metal pad 2211 on the second surface through a via in the substrate, second metal pad 222 is connected to metal pad 2221 on the second surface through a via in the substrate, third metal pad 241 is connected to metal pad 2411 on the second surface through a via in the substrate, and fourth metal pad 242 is connected to metal pad 2421 on the second surface through a via in the substrate.

[0063] The embodiment of the present invention further provides a method for preparing a laser module structure, which is used to form the laser module structure described in any of the above embodiments. Figure 5 This is a flow chart of a method for preparing a laser module structure provided by an embodiment of the present invention, with reference to Figure 5 , the preparation method of the laser module structure includes:

[0064] S110 , providing a substrate connecting plate, wherein the substrate connecting plate includes a first surface and a second surface opposite to the first surface.

[0065] Specifically, the material of the substrate connecting plate may include semiconductor packaging materials such as aluminum nitride, aluminum oxide or beryllium oxide, or may be a ceramic substrate.

[0066] S120, forming a plurality of first metal pad pairs arranged in an array on the first surface of the substrate connecting plate; each first metal pad pair includes a first metal pad and a second metal pad fixed on the first surface.

[0067] Specifically, high-precision film is used to pattern the metal pads, and the specific pattern is adjusted according to the laser chip size and patch requirements.

[0068] S130, bonding multiple laser chips to the first metal pads in a one-to-one correspondence; wherein the laser chip is fixed on the surface of the first metal pad away from the substrate connecting plate, and the leads of the laser chip are connected to the second metal pad to form a light-emitting unit.

[0069] Specifically, each light-emitting unit includes a laser chip and a first metal pad pair connected to the laser chip. The laser chip is fixed to the surface of the first metal pad using a die bond process, and the laser chip is connected to the second metal pad using a wire bond process. A voltage signal is provided to the laser chip via the first and second metal pads to drive the laser chip to emit light.

[0070] S140. Prepare an optical lens connecting plate by using a mold injection molding or compression molding process; the optical lens connecting plate includes an optical lens corresponding to the light-emitting unit array, and the optical lens has a cavity for accommodating the light-emitting unit.

[0071] Specifically, optical lenses can be formed through an injection molding process. Injection molds are designed and processed according to optical requirements, and optical lens panels are mass-produced through the injection molding process. The number of optical lenses in an optical lens panel depends on the number of mold cavities. The materials of the optical lenses can include polycarbonate, silicone, or acrylic. Through the injection molding process, multi-cavity molds can be customized to perform batch array lens injection molding, thereby improving production efficiency. In addition, the surface shape of the optical lens can be customized through the mold, which greatly reduces the material cost and development cycle of the optical lens while improving product performance and application range.

[0072] S150. Form an adhesive layer on the first surface of the substrate connecting plate; the adhesive layer is arranged around the outer edge of the light-emitting unit; the height of the first metal pad relative to the substrate connecting plate is greater than or equal to the height of the adhesive layer relative to the substrate connecting plate, and the height range of the adhesive layer relative to the substrate meets the preset bonding thickness.

[0073] S160, pressing the optical lens connecting plate onto the first surface of the substrate connecting plate and fixing it with an adhesive layer.

[0074] Specifically, Figure 6 This is a schematic diagram of the structure of a substrate connected to a laser chip after bonding provided by an embodiment of the present invention. Figure 6 , the substrate connecting plate 100 is used as the lower mold, and an adhesive layer is formed on the first surface of the substrate connecting plate 100. The adhesive layer is arranged around the outer edge of the light-emitting unit. High-precision positioning holes 101 are set on the edges of the substrate connecting plate 100 for mold positioning. The optical lens connecting plate is used as the upper mold, and the optical lens connecting plate is pressed onto the first surface of the substrate connecting plate 100, and the adhesive layer is cured by heating. The material of the adhesive layer may include silicone or epoxy resin. The encapsulation bonding is achieved by silicone, and the hardness of the adhesive layer is relatively low. The soft silicone can release stress and improve the reliability of the package.

[0075] In addition, while setting the height range of the adhesive layer relative to the substrate connecting plate to meet the preset bonding thickness to ensure the adhesive layer's firm adhesion to the optical lens, at least the first metal pad on which the laser chip is located is elevated to prevent the coated adhesive layer from contaminating the chip and ensure the operating performance of the semiconductor laser. That is, after the adhesive layer is cured, the height of the first metal pad relative to the substrate connecting plate is greater than or equal to the height of the adhesive layer relative to the substrate connecting plate. By elevating the first metal pad on which the laser chip is located, the thickness of the formed adhesive layer can also be relatively increased, increasing the depth to which the optical lens extends into the adhesive layer. This can reduce the cross-sectional area of the end of the optical lens extending into the adhesive layer while ensuring the firm fixation of the optical lens, thereby further reducing the volume of the laser module.

[0076] S170 , cutting the semi-finished product after the optical lens connecting plate and the base plate are pressed and fixed according to the number of light-emitting units in the laser module structure, so as to form a single laser module structure with independent functions.

[0077] The laser module structure preparation method provided by the embodiment of the present invention performs micro-lens processing through an injection molding process. The corresponding lens material can be selected according to different application scenarios or performance requirements, and sub-micron surface lens processing can be achieved. The laser chips are mounted in batches on the substrate connecting plate, and then the optical lens connecting plate and the substrate connecting plate are assembled through the molding process to achieve micron-level assembly accuracy. Molding bonding is achieved by silicone, which has good environmental stability and hardness. Moreover, by fixing the optical lens through the adhesive layer, the volume of the module product can be reduced compared to mounting the optical lens on the dam / bracket on the substrate. By designing the difference in thickness of the substrate pad, the first metal pad on which the laser chip is provided is raised, so that the height of the first metal pad relative to the substrate is greater than or equal to the height of the adhesive layer relative to the substrate, thereby avoiding the contamination of the chip by the uncured glue during the preparation of the laser module structure and ensuring the working performance of the semiconductor laser. In addition, by raising the first metal pad on which the laser chip is provided, the maximum thickness of the formed adhesive layer can be relatively raised, thereby increasing the depth of the optical lens extending into the adhesive layer. While reducing the cross-sectional area of the end of the optical lens extending into the adhesive layer, the firmness of the optical lens fixation can be ensured, thereby further reducing the volume of the semiconductor laser.

[0078] Figure 7 This is a flow chart of another method for preparing a laser module structure provided by the second embodiment of the present invention, with reference to Figure 7 , the preparation method of the laser module structure includes:

[0079] S210 , providing a substrate connecting plate, wherein the substrate connecting plate includes a first surface and a second surface opposite to the first surface.

[0080] S220, forming a plurality of first metal pad pairs arranged in an array on the first surface of the substrate connecting plate; each first metal pad pair includes a first metal pad and a second metal pad fixed on the first surface.

[0081] S230, bonding multiple laser chips to the first metal pads in a one-to-one correspondence; wherein the laser chip is fixed on the surface of the first metal pad away from the substrate connecting plate, and the leads of the laser chip are connected to the second metal pad to form a light-emitting unit.

[0082] S240, preparing an optical lens connecting plate by using a mold injection molding or compression molding process; the optical lens connecting plate includes an optical lens corresponding to the light emitting unit array, and the optical lens has a cavity for accommodating the light emitting unit.

[0083] S250. Use a glue dispenser to apply glue on the area where the glue layer is located on the first surface of the substrate connecting plate; the glue layer is arranged around the outer edge of the light-emitting unit; the height of the first metal pad relative to the substrate connecting plate is greater than or equal to the height of the glue layer relative to the substrate connecting plate, and the height range of the glue layer relative to the substrate meets the preset bonding thickness.

[0084] S260, pressing the optical lens connecting plate onto the first surface of the substrate connecting plate and fixing it with an adhesive layer.

[0085] S270. Cut the semi-finished product after the optical lens connecting plate and the base plate are pressed and fixed according to the number of light-emitting units in the laser module structure to form a single laser module structure with independent functions.

[0086] Based on the above-mentioned embodiments, the laser module structure fabrication method provided in the embodiments of the present invention includes a method of forming an adhesive layer on the first surface of the substrate by applying adhesive to the area of the first surface of the substrate where the adhesive layer is located. The adhesive dispensing machine can precisely control the amount of adhesive, preventing excessive adhesive application and further contamination of the laser chip by adhesive overflow. It can also prevent insufficient adhesive application, which could result in insufficient adhesion of the adhesive layer to the optical lens.

[0087] Figure 8 This is a flow chart of another method for preparing a laser module structure provided by the second embodiment of the present invention, with reference to Figure 8 , the preparation method of the laser module structure includes:

[0088] S310 , providing a substrate connecting plate, wherein the substrate connecting plate includes a first surface and a second surface opposite to the first surface.

[0089] S320. A plurality of first metal pad pairs are formed in an array on the first surface of the substrate connecting plate, and a barrier layer is formed on the inner side of the edge of the first surface of the substrate connecting plate; each first metal pad pair includes a first metal pad and a second metal pad fixed on the first surface.

[0090] S330, bonding multiple laser chips to the first metal pads in a one-to-one correspondence; wherein the laser chip is fixed on the surface of the first metal pad away from the substrate connecting plate, and the leads of the laser chip are connected to the second metal pad to form a light-emitting unit.

[0091] S340. Prepare an optical lens connecting plate by using a mold injection molding or compression molding process; the optical lens connecting plate includes an optical lens corresponding to the light-emitting unit array, and the optical lens has a cavity for accommodating the light-emitting unit.

[0092] S350. Determine the total amount of glue required to form a glue layer, inject the glue of the total amount into the glue injection position of the substrate connecting plate, and form a glue layer based on the fluidity of the glue; the height of the first metal pad relative to the substrate connecting plate is greater than or equal to the height of the glue layer relative to the substrate connecting plate, and the height range of the glue layer relative to the substrate meets the preset bonding thickness.

[0093] S360, pressing the optical lens connecting plate onto the first surface of the substrate connecting plate and fixing it with an adhesive layer.

[0094] S370. Cut the semi-finished product after the optical lens connecting plate and the base plate are pressed and fixed according to the number of light-emitting units in the laser module structure to form a single laser module structure with independent functions.

[0095] On the basis of the above-mentioned embodiments, the laser module structure preparation method provided by the embodiment of the present invention determines the total amount of glue required to form the glue layer when forming the glue layer on the first surface of the substrate, injects the total amount of glue into the glue injection position of the substrate connecting plate, and forms the glue layer based on the fluidity of the glue. By raising the height of the metal pad, the height of the first metal pad relative to the substrate connecting plate is greater than or equal to the height of the glue layer relative to the substrate connecting plate, thereby avoiding glue overflow to the surface of the laser chip and contaminating the laser chip. It should be noted that before injecting the glue into the glue injection position of the substrate and forming the glue layer based on the fluidity of the glue, it is also necessary to form a circle of barrier layer on the inner side of the edge of the first surface of the substrate connecting plate to prevent the injected glue from flowing to the back side of the substrate. The material of the barrier layer can be a metal material. While forming the first metal pad pair arranged in an array on the first surface of the substrate connecting plate, a circle of barrier layer is electroplated on the inner side of the edge of the first surface of the substrate connecting plate.

[0096] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A laser module structure, characterized in that: include: a substrate comprising a first surface and a second surface opposite to the first surface; at least one light-emitting unit, wherein the light-emitting unit is located on the first surface of the substrate; an adhesive layer, the adhesive layer being located on the first surface of the substrate, and at least a portion of the adhesive layer being disposed around an outer side of an edge of the light-emitting unit; an optical lens provided in one-to-one correspondence with the light-emitting units, the optical lens being fixed to the substrate via the adhesive layer; the optical lens having a cavity for accommodating the light-emitting units; In which, the light-emitting unit includes a laser chip and a first metal pad pair connected to the laser chip; the first metal pad pair includes a first metal pad and a second metal pad fixed on the first surface; the laser chip is fixed on the surface of the first metal pad away from the substrate, and the lead of the laser chip is connected to the second metal pad; the height of the first metal pad on which the laser chip is provided is raised so that the height of the first metal pad relative to the substrate is greater than or equal to the height of the adhesive layer relative to the substrate, and the height of the adhesive layer relative to the substrate meets the thickness corresponding to the adhesive layer under a preset bonding strength; the bonding portion of the optical lens in contact with the adhesive layer extends into the adhesive layer.

2. The laser module structure according to claim 1, characterized in that: Along the direction of the adhesive layer pointing toward the substrate, the cross-sectional area of the adhesive portion where the optical lens contacts the adhesive layer gradually decreases.

3. The laser module structure according to claim 1, characterized in that: At least one light emitting unit further includes a sensor and a second metal pad pair connected to the sensor; The second metal pad pair includes a third metal pad and a fourth metal pad fixed on the first surface; the sensor is fixed on the surface of the third metal pad away from the substrate, and the lead of the sensor is connected to the fourth metal pad; the height of the third metal pad relative to the substrate is greater than or equal to the height of the adhesive layer relative to the substrate.

4. The laser module structure according to claim 3, characterized in that: The second surface of the substrate further includes a pair of external metal pads connected to each of the first metal pads, and a pair of external metal pads connected to each of the second metal pads.

5. The laser module structure according to claim 3, characterized in that: The sensor includes a photosensor or a temperature sensor.

6. The laser module structure according to claim 1, characterized in that: The material of the substrate includes aluminum nitride, aluminum oxide or beryllium oxide; the material of the optical lens includes polycarbonate, silicone or acrylic; the material of the adhesive layer includes silicone or epoxy resin.

7. A method for preparing a laser module structure, characterized in that: Used to form the laser module structure according to any one of claims 1 to 6, comprising: Providing a substrate connecting plate, the substrate connecting plate comprising a first surface and a second surface opposite to the first surface; forming a plurality of first metal pad pairs arranged in an array on the first surface of the substrate connecting plate; each of the first metal pad pairs includes a first metal pad and a second metal pad fixed on the first surface; Bonding a plurality of laser chips to the first metal pads in a one-to-one correspondence; wherein the laser chips are fixed on a surface of the first metal pad away from the substrate connecting plate, and the leads of the laser chips are connected to the second metal pads to form a light-emitting unit; The optical lens connecting plate is manufactured by a mold injection molding or compression molding process; the optical lens connecting plate includes an optical lens corresponding to the light-emitting unit array, and the optical lens has a cavity for accommodating the light-emitting unit; An adhesive layer is formed on the first surface of the substrate connecting plate; at least a portion of the adhesive layer is disposed around the outer edge of the light-emitting unit; the height of the first metal pad relative to the substrate connecting plate is greater than or equal to the height of the adhesive layer relative to the substrate connecting plate; and the height of the adhesive layer relative to the substrate satisfies the thickness of the adhesive layer corresponding to a predetermined bonding strength. Pressing the optical lens connecting plate onto the first surface of the substrate connecting plate and fixing it via the adhesive layer; According to the number of light-emitting units included in the laser module structure, the semi-finished product after the optical lens connecting plate and the base plate are pressed and fixed is cut to form a single laser module structure with independent functions.

8. The method for preparing a laser module structure according to claim 7, wherein: The step of forming a glue layer on the first surface of the substrate connecting plate comprises: Glue is applied on the area where the glue layer is located on the first surface of the substrate connecting plate by a glue dispenser.

9. The method for preparing a laser module structure according to claim 7, wherein: The step of forming a glue layer on the first surface of the substrate connecting plate comprises: The total amount of glue required to form the glue layer is determined, and the glue of the total amount is injected into the glue injection position of the substrate connecting plate to form the glue layer based on the fluidity of the glue.

10. The method for preparing a laser module structure according to claim 9, wherein: Before determining the total glue amount required to form the glue layer, injecting the glue of the total glue amount into the glue injection position of the substrate connecting plate, and forming the glue layer based on the fluidity of the glue, the method further includes: A barrier layer is formed on the inner side of the edge of the first surface of the substrate connecting plate, and the barrier layer is used to prevent the injected glue from flowing to the back side of the substrate connecting plate.

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