CN116683279A - Multi-wavelength semiconductor laser coupling packaging structure and packaging method - Google Patents

Abstract

The application provides a coupling packaging structure and a packaging method of a multi-wavelength semiconductor laser, belonging to the technical field of photoelectricity, comprising the following steps: a tube shell, a refrigerating sheet, a ceramic sheet and a branch optical fiber. The tube shell is used for packaging the refrigerating sheet and the trapezoid ALN ceramic sheet welded with the chips and providing pins for the chips. The refrigerating sheet is fixedly arranged on the bottom surface of the tube shell, the ceramic sheet is fixedly arranged on the refrigerating sheet, a plurality of mounting steps are arranged on the ceramic sheet, and a plurality of chips are correspondingly attached to different mounting steps one by one; the optical fibers are connected with the chips in a one-to-one correspondence manner, and the optical fibers are fused into one coupling optical fiber and led out of the tube shell. The multi-wavelength semiconductor laser coupling packaging structure provided by the application packages a plurality of chips with different wavelengths in the same tube shell, and fuses the branch optical fibers connected with the chips into one coupling optical fiber, thereby realizing miniaturization during packaging, saving the whole machine space and realizing miniaturization of the whole machine.

Description

Multi-wavelength semiconductor laser coupling packaging structure and packaging method

Technical Field

The application belongs to the technical field of photoelectricity, and particularly relates to a coupling packaging structure and a packaging method of a multi-wavelength semiconductor laser.

Background

With the application of semiconductor lasers, the laser photoelectron technology is undergoing a deep structural transformation, the development trend is solidification, integration and high efficiency, and the improvement of the performance of the semiconductor lasers is becoming a powerful motive force for promoting the progress of the laser photoelectron technology. Semiconductor lasers have very outstanding advantages over other types of lasers: the working efficiency is very high, and the energy consumption is low; the service life is long; high direct modulation capability; the volume is small, and the weight is light; high cost performance. These excellent characteristics make semiconductor lasers very important applications in the fields of optical communications, optical information access, pumping high-power solid and fiber lasers, laser weapons, biology and medicine.

Semiconductor lasers have become a highly innovative technology for worldwide development as a key device for the optoelectronic industry. The semiconductor laser has the other important characteristic of high continuous output power, and the laser emitted by the semiconductor laser is coupled by the optical fiber, so that the market application is greatly facilitated; the optical fiber coupling modes in the optical fiber coupling process are various, and include modes of optical fiber direct alignment, optical fiber alignment after a quartz wire compresses a fast axis, lens coupling and the like. The direct alignment mode is convenient and quick, the structure is simple, the environmental adaptability is strong, the optical fiber coupling mode of a single chip is common, when the pump and illumination calibration application aiming at different wavelengths is carried out, the chips with multiple wavelengths are required to work alternately, the whole structure is complex, the occupied space is large, and the whole miniaturization of the product is not facilitated.

Disclosure of Invention

The embodiment of the application provides a coupling packaging structure and a packaging method of a multi-wavelength semiconductor laser, which integrate a plurality of chips with different wavelengths into a tube shell and solve the problems of large volume and large occupied space of packaged products.

In order to achieve the above object, the present application adopts the following technical scheme: provided is a coupling package structure of a multi-wavelength semiconductor laser, including:

a tube shell;

the refrigerating sheet is fixedly arranged on the bottom surface of the tube shell;

the ceramic plate is fixedly arranged on the refrigerating plate, a plurality of mounting steps are arranged on the ceramic plate, and a plurality of chips are correspondingly attached to different mounting steps one by one; and

and branch optical fibers connected with the chips in one-to-one correspondence are fused into one coupling optical fiber, and the coupling optical fibers are led out from the tube shell.

In combination with the first aspect, in one implementation manner, the ceramic plate is trapezoidal, the small end of the ceramic plate faces the direction of the coupling optical fiber, the mounting steps are distributed on the ceramic plate in a fan shape, meanwhile, the chips are fixedly arranged on the mounting steps in a fan shape, and the branch optical fibers are connected with the chips in a radial shape.

With reference to the first aspect, in one implementation manner, an optical fiber placement groove is provided on the ceramic wafer along the trend of the branch optical fiber, and the branch optical fiber is embedded in the optical fiber placement groove.

With reference to the first aspect, in one implementation manner, the width of the optical fiber placement groove is d+0.5, the depth is D, and the unit is um; wherein D is the diameter of the branch optical fiber.

With reference to the first aspect, in one implementation manner, the ceramic wafer is an AlN ceramic wafer.

With reference to the first aspect, in one implementation manner, the tube shell is a tungsten copper part.

With reference to the first aspect, in an implementation manner, a thermistor is further disposed on the ceramic chip.

With reference to the first aspect, in one implementation manner, the end faces of the branch optical fibers are respectively provided with microlenses.

In a second aspect, an embodiment of the present application further provides a method for coupling and packaging a multi-wavelength semiconductor laser, where the method includes:

step one, processing a ceramic wafer by adopting an etching process; etching an optical fiber placing groove and an installation step for installing a chip on the ceramic wafer, and prefabricating gold-tin solder on the installation step;

sintering chips with different wavelengths on different mounting steps, and controlling the sintering precision of the chips to +/-0.5 um;

thirdly, welding the ceramic sheet sintered with the chip on the refrigerating sheet through secondary sintering, and simultaneously welding the refrigerating sheet on the bottom surface of the tube shell through secondary sintering;

fourthly, performing ultrasonic pressure welding on the chip and the pins through gold wires;

step five, designing a micro lens at the end part of the branch optical fiber according to optical simulation, and simultaneously calculating the working distance between the end face of the micro lens of the branch optical fiber and the end face of the chip to be 5.2+/-0.5 um;

step six, placing the branch optical fiber at a position which is away from the light emitting end face of the chip by the working distance under a microscope, and bonding the branch optical fiber on the ceramic chip by ultraviolet glue;

seventh, the optical fibers are fused into a coupling optical fiber in a fused tapering mode, and are output from the inside of the tube shell.

With reference to the second aspect, in one possible manner, the ceramic sheet is an AlN ceramic sheet, and the thermal expansion coefficient of the AlN ceramic sheet is 4.5ppm/K; the chip has a GaAs substrate having a thermal expansion coefficient of 6.5ppm/K.

Compared with the prior art, the multi-wavelength semiconductor laser coupling packaging structure and the packaging method have the beneficial effects that: the chips with different wavelengths are packaged in the same tube shell, and the branch optical fibers connected with the chips are fused into one coupling optical fiber, so that miniaturization during packaging is realized, the space of the whole machine is saved, and miniaturization of the whole machine can be realized.

Drawings

Fig. 1 is a schematic perspective view of a coupling package structure of a multi-wavelength semiconductor laser according to an embodiment of the present application;

fig. 2 is a schematic plan view of a coupling package structure of a multi-wavelength semiconductor laser according to an embodiment of the present application;

fig. 3 is a schematic top view of a multi-wavelength semiconductor laser coupling package structure according to an embodiment of the present application;

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 3;

FIG. 5 is a partially enlarged structural view of the portion C in FIG. 4;

FIG. 6 is a schematic perspective view of a fiber support and a ceramic plate according to an embodiment of the present application;

FIG. 7 is a schematic perspective view of a ceramic wafer according to an embodiment of the present application;

FIG. 8 is a schematic diagram of a branch fiber coupling structure used in an embodiment of the present application;

FIG. 9 is a partial enlarged view of the structure of FIG. 8B;

reference numerals illustrate:

1. a tube shell; 2. a cooling sheet; 3. a ceramic sheet; 301. etching a groove; 302. mounting steps; 303. an optical fiber placement groove; 4. a chip; 5. an optical fiber is branched; 6. coupling an optical fiber; 7. limiting convex ribs; 8. a pin; 9. a thermistor.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

Referring to fig. 1 to 9, a description will be given of a multi-wavelength semiconductor laser coupling package structure provided by the present application. The multi-wavelength semiconductor laser coupling packaging structure comprises: a tube shell 1, a refrigerating sheet 2, a ceramic sheet 3 and a branch optical fiber 5. The package 1 is used for packaging the refrigerating sheet 2, the trapezoid ALN ceramic sheet 3 welded with the chips 4, and provides pins 8 for each chip 4.

The refrigerating sheet 2 is fixedly arranged on the bottom surface of the tube shell 1, the chip 4 is fixed on the refrigerating sheet 2 and used for controlling the temperature of the semiconductor laser chip 4, the working temperature of the chip 4 is ensured to be constant under different environmental temperatures and different currents, and the refrigerating sheet 2 is a TEC thermoelectric refrigerator (TE is Thermoelectric Cooler).

The ceramic plate 3 is fixedly arranged on the refrigerating plate 2, a plurality of mounting steps 302 are arranged on the ceramic plate 3, and a plurality of chips 4 are correspondingly attached to different mounting steps 302 one by one; the optical fibers 5 of each chip 4 are connected in one-to-one correspondence, and the optical fibers 5 are fused into one coupling optical fiber 6 which is led out from the tube shell 1. Specifically, the plurality of optical fibers 5 are tapered wedge-shaped coupling optical fibers 6, three optical fibers 5 with different wavelengths are output through a single optical fiber in a fused tapering mode, so that wavelength division multiplexing is realized, meanwhile, the same wedge angle is processed on the end face of each optical fiber 5 close to the chip 4 to form the wedge-shaped coupling optical fibers 6, and micro lenses are manufactured on the end face, so that light rays can be transmitted conveniently.

Compared with the prior art, the coupling packaging structure of the multi-wavelength semiconductor laser has the beneficial effects that: the chips 4 with different wavelengths are packaged in the same tube shell 1, and the branch optical fibers 5 connected with the chips 4 are fused into one coupling optical fiber 6, so that the miniaturization during packaging is realized, the whole machine space is saved, and the miniaturization of the whole machine can be realized. The semiconductor laser developed based on the packaging structure can be applied to the fields of laser pumping, laser communication, optical sensor, laser calibration and the like.

In some embodiments, as shown in fig. 1 to 7, the ceramic plate 3 is trapezoidal, the small end of the ceramic plate 3 faces the direction of the coupling optical fiber 6, each mounting step 302 is distributed on the ceramic plate 3 in a fan shape, meanwhile, each chip 4 is fixed on the mounting step 302 in a fan shape, and each optical fiber 5 is connected with each chip 4 in a radial shape.

The embodiment designs the high-precision trapezoid ALN ceramic chip 3 and the tapered wedge-shaped coupling optical fiber 6, has the characteristics of compact structure, simple system, high debugging-free coupling speed and capability of realizing multi-wavelength output according to the number of packaged chips 4, and the semiconductor laser developed based on the application can be applied to the fields of laser pumping, laser communication, optical sensors, laser calibration and the like.

In this embodiment, three chips 4 are disposed on the ceramic sheet 3; according to the functional requirement of the laser, four, five and other chips 4 can be arranged, each chip 4 corresponds to one optical fiber 5, and a coupling optical fiber 6 is formed through fusion.

In some embodiments, as shown in fig. 1 to 7, an optical fiber placement groove 303 is provided on the ceramic sheet 3 along the direction of the optical fiber 5, and the optical fiber 5 is embedded in the optical fiber placement groove 303. The optical fiber placement groove 303 has the functions of limiting, protecting and guiding the optical fiber.

In some embodiments, as shown in fig. 1-7, the fiber placement groove 303 has a width d+0.5, a depth D, and a unit of um; wherein D is the diameter of the branch optical fiber 5. For example, the diameter of the branch optical fiber 5 is 125um, and the depth of the optical fiber placement groove 303 is 62.5um and the width is 125.5um. The lateral end surface of the optical fiber placement groove 303 may be rectangular in shape, trapezoidal in shape, U-shaped in shape, or circular in shape.

In some embodiments, ceramic wafer 3 is an AlN ceramic wafer. The ceramic plate 3 is designed as a heat sink structure, in the embodiment, the tube shell 1 adopts a tungsten copper product as a main heat dissipation component, and adopts an AlN ceramic plate as a secondary heat sink, because the thermal expansion coefficient (4.5 ppm/K) of the AlN ceramic plate is very close to the thermal expansion coefficient (6.5 ppm/K) of the GaAs substrate of the chip 4, the packaging stress caused by the unmatched thermal expansion coefficients between the chip 4 and the heat sink can be well relieved; secondly, the chip 4 is sintered on the ceramic sheet 3, and the expansion coefficients of the chip 4 and the ceramic sheet are close to each other, so that the sintering process can be optimized, the void ratio of a welding layer is reduced as much as possible, and the stress caused by different thermal expansion coefficients between the chip 4 and a heat sink is effectively reduced.

In some embodiments, the envelope 1 is a tungsten copper part. Wherein, as shown in fig. 1, the bottom of tube shell 1 is provided with spacing protruding muscle 7, and the bottom of potsherd 3 is provided with the joint groove of joint on spacing muscle, through spacing protruding muscle 7 and the cooperation in joint groove, to the spacing of potsherd 3 realization, the potsherd 3 of being convenient for is welded fixedly and has promoted the accuracy of potsherd 3 welding position.

In some embodiments, as shown in fig. 1-2, a thermistor 9 is also provided on the ceramic sheet 3. In combination with the above embodiments, the specific structure of the semiconductor laser coupling package structure provided in this embodiment is as follows: the laser chip 4 with multiple wavelengths is adopted, the thermistor 9 is welded on the trapezoid ALN ceramic plate 3 through high-temperature solder, the trapezoid ALN ceramic plate 3 and the TEC thermoelectric cooler are welded on the tube shell 1 through secondary sintering, and the laser is coupled and output through multiple wedge-shaped optical fibers.

In some embodiments, the end faces of the branch optical fibers 5 are provided with microlenses, respectively.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.

Based on the same inventive concept, the embodiment of the application also provides a multi-wavelength semiconductor laser coupling and packaging method, which comprises the following steps of:

step one, processing a ceramic sheet 3 by adopting an etching process; etching an optical fiber placing groove 303 and a mounting step 302 for mounting a chip 4 on the ceramic sheet 3, and prefabricating gold-tin solder on the mounting step 302;

step two, sintering the chips 4 with different wavelengths on different mounting steps 302, and controlling the sintering precision of the chips 4 to be +/-0.5 um;

thirdly, welding the ceramic sheet 3 sintered with the chip 4 on the refrigerating sheet 2 through secondary sintering, and simultaneously welding the refrigerating sheet 2 on the bottom surface of the tube shell 1 through secondary sintering;

fourthly, performing ultrasonic pressure welding on the chip 4 through gold wires and pins 8;

step five, designing a micro lens at the end part of the branch optical fiber 5 according to optical simulation, and simultaneously calculating the working distance between the end face of the micro lens of the branch optical fiber 5 and the end face of the chip 4 to be 5.2+/-0.5 um, as shown in fig. 5;

step six, placing the branch optical fiber 5 at a position which is away from the working distance of the light emitting end face of the chip 4 under a microscope, and bonding the branch optical fiber 5 on the ceramic sheet 3 by ultraviolet glue;

step seven, the plurality of optical fibers 5 are fused into one coupling fiber 6 by fusion tapering, and output from the inside of the package 1, as shown in fig. 1 and 2.

The packaging method provided by the application can well solve the packaging problem of multi-wavelength coupling, saves the space of the whole machine and can realize the miniaturization of the system. The packaging structure is simple, the operation is convenient, the three-wavelength coupling can be realized, the optical fiber placing groove 303 is precisely positioned by adopting the etching process, and the optical fiber coupling speed of the semiconductor laser can be remarkably improved.

Optionally, in the first step, when the mounting step 302 is etched, etching the periphery of the mounting step 302 into the etching groove 301, where the mounting step 302 is isolated in the etching groove 301 and is not connected with the peripheral side walls of the etching groove 301; meanwhile, the height of the mounting step 302 is lower than the depth of the etching groove 301, that is, the upper surface of the mounting step 302 reserves a mounting space for the chip 4, and after the chip 4 is mounted, the upper surface of the chip 4 does not protrude from the surface of the ceramic sheet 3.

In the second step, the specific operation of sintering the multi-wavelength laser chip 4 is as follows: the high-precision assembly of the chips 4 is completed by adopting a high-precision full-automatic sintering furnace, 3 laser chips 4 with different wavelengths are placed in different chip 4 tray clamps for standby, technological parameters such as sintering temperature, sintering precision and the like are set, and the system completes the sintering of the three chips 4 according to the set conditions. And controlling the precision in the processes of picking, aligning, placing, pressing and sintering the chip 4, wherein the final sintering position precision of the chip 4 is controlled within +/-0.5 um.

In the fourth step, a 30um gold wire is adopted to weld the chip 4 and the pins 8 together.

In step five, according to the optical design simulation, the microlens is designed as shown in fig. 9, and the optimum working distance between the lens end face and the end face of the chip 4 is calculated to be about 5.2um, as shown in fig. 5.

The case where the plurality of laser chips 4 correspond to the coupling of the plurality of branch optical fibers 5: the optical fiber wedge angle level is corrected without debugging, and the optical fiber clamp is used for clamping a proper position, and the optical fiber is placed under a microscope and is glued by ultraviolet glue at a position 5um away from the light emitting end face of the chip 4. The optical fiber placing groove 303 is etched on the ceramic plate 3 through a high-precision etching process and a sintering process, so that the encapsulation coupling of the semiconductor lasers with multiple wavelengths is finished, a six-dimensional debugging process during laser coupling is omitted, and the coupling efficiency can reach more than 90%.

In the seventh step, the multi-wavelength coupling optical fiber 6 is designed and manufactured: the single-mode semiconductor laser with the quantum well structure has larger light spot size difference in two directions at present, high asymmetry is presented, the divergence angle in the fast axis direction is generally 30 degrees, the divergence angle in the slow axis direction is about 10 degrees, a wedge-shaped micro lens is generally designed at the end of a branch optical fiber 5 for coupling, only fast axis optical compression is carried out, the light emergent surface of a chip 4 is directly aligned, and optical fiber coupling is completed. That is, the end surfaces of the branch optical fibers 5 are provided with wedge-shaped microlenses, respectively.

In one possible way, the ceramic plate 3 is an AlN ceramic plate, the thermal expansion coefficient of which is 4.5ppm/K; the chip 4 has a GaAs substrate having a thermal expansion coefficient of 6.5ppm/K.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application.

Claims (10)

1. A multi-wavelength semiconductor laser coupling package structure, comprising:

a tube shell (1);

the refrigerating sheet (2) is fixedly arranged on the bottom surface of the tube shell (1);

the ceramic plate (3) is fixedly arranged on the refrigerating plate (2), a plurality of mounting steps (302) are arranged on the ceramic plate (3), and a plurality of chips (4) are correspondingly attached to different mounting steps (302) one by one; and

and branch optical fibers (5) which are connected with the chips (4) in a one-to-one correspondence manner are integrated into one coupling optical fiber (6), and the coupling optical fibers are led out from the tube shell (1).

2. The multi-wavelength semiconductor laser coupling and packaging structure according to claim 1, wherein the ceramic plate (3) is trapezoidal in shape, the small end of the ceramic plate (3) faces the direction of the coupling optical fiber (6), each mounting step (302) is distributed on the ceramic plate (3) in a fan shape, meanwhile, each chip (4) is fixedly arranged on the mounting step (302) in a fan shape, and each branch optical fiber (5) is connected with each chip (4) in a radial shape.

3. The multi-wavelength semiconductor laser coupling and packaging structure according to claim 2, wherein an optical fiber placement groove (303) is formed in the ceramic wafer (3) along the trend of the branch optical fiber (5), and the branch optical fiber (5) is embedded in the optical fiber placement groove (303).

4. The multi-wavelength semiconductor laser coupling package structure of claim 3, wherein the optical fiber placement groove (303) has a width d+0.5, a depth D, and a unit of um; wherein D is the diameter of the branch optical fiber (5).

5. The multi-wavelength semiconductor laser coupling package structure according to claim 1, wherein the ceramic sheet (3) is an AlN ceramic sheet (3).

6. The multi-wavelength semiconductor laser coupling package according to claim 1, wherein the package (1) is a tungsten copper part.

7. The multi-wavelength semiconductor laser coupling package structure according to claim 1, wherein a thermistor (9) is further provided on the ceramic sheet (3).

8. The multi-wavelength semiconductor laser coupling package structure according to claim 1, wherein the end surfaces of the branch optical fibers (5) are respectively provided with microlenses.

9. A method of coupling and packaging a multi-wavelength semiconductor laser, wherein the method comprises:

step one, processing a ceramic wafer (3) by adopting an etching process; etching an optical fiber placing groove (303) and a mounting step (302) for mounting a chip (4) on the ceramic wafer (3), and prefabricating gold-tin solder on the mounting step (302);

step two, sintering the chips (4) with different wavelengths on different mounting steps (302), and controlling the sintering precision of the chips (4) to be +/-0.5 um;

thirdly, welding the ceramic sheet (3) sintered with the chip (4) on the refrigerating sheet (2) through secondary sintering, and simultaneously welding the refrigerating sheet (2) on the bottom surface of the tube shell (1) through secondary sintering;

fourthly, performing ultrasonic pressure welding on the chip (4) and the pins (8) through gold wires;

step five, designing a micro lens at the end part of the branch optical fiber (5) according to optical simulation, and simultaneously calculating the working distance between the end face of the micro lens of the branch optical fiber (5) and the end face of the chip (4) to be 5.2+/-0.5 um;

step six, placing the branch optical fiber (5) at a position which is away from the light emitting end face of the chip (4) by the working distance under a microscope, and bonding the branch optical fiber (5) on the ceramic sheet (3) by ultraviolet glue;

seventh, the optical fibers (5) are fused into one coupling optical fiber (6) by a fused tapering mode, and are output from the inside of the tube shell (1).

10. The coupling and packaging method of the multi-wavelength semiconductor laser according to claim 9, wherein the ceramic wafer (3) is an AlN ceramic wafer (3), and the thermal expansion coefficient of the AlN ceramic wafer (3) is 4.5ppm/K; the chip (4) has a GaAs substrate having a thermal expansion coefficient of 6.5ppm/K.