Multi-chip packaged semiconductor laser

Abstract

The invention provides a multi-chip packaged semiconductor laser, which comprises a tube shell, a plurality of equidistant step structures in the tube shell, a plurality of laser chips, a plurality of collimating lenses and a relay heat sink, and a plurality of diaphragms and tube shell pins on the side wall of the tube shell, wherein the equidistant step structures at the bottom of the tube shell are used for bearing and fixing the laser chips, the laser chips have the same light emitting direction, the collimating lens is fixed at the front end of the light emitting direction of the laser chips and is used for collimating the emergent laser of the laser chips, and the window sheets are fixed on the side wall of the tube shell and are in one-to-one correspondence with the laser chips. And the collimated laser is transmitted to the outside of the tube shell through the diaphragm to form a plurality of paths of parallel light beams with equal height or unequal height. According to the invention, slow-axis coupling lenses, reflectors and the like are reduced in the sealed shell, the coupling difficulty of optical elements of the sealed shell and the size of the shell are reduced, the cost is reduced, and the reliability of the product is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor lasers, and in particular to a multi-chip packaged semiconductor laser. Background Art

[0002] The packaging technologies for semiconductor lasers include butterfly packaging, TO packaging, shell packaging, etc. Among them, butterfly packaging and TO-CAN packaging are generally used for single laser chips, and shell packaging is generally used for packaging multiple chips and converging multiple beams of light to optical fiber or window output.

[0003] Since the power of a single laser chip is low, multiple chips need to be used for spatial and wavelength combination to achieve the total power requirement. The existing patent application CN 114976876 (a multi-chip packaged semiconductor laser) uses a TO-shaped laser to combine multiple chips. The disadvantages are large size and long chip heat dissipation path. The use of divergent light TO requires optical coupling packaging again, the collimating lens design is limited, and the parallelism of the output beams of multiple TO packages is limited by TO multi-batch packaging, and the consistency is poor; at the same time, multiple laser chips are used to couple to one laser, which can be used directly after output. The disadvantages are that there are many internal optical components, the process time and process flow are long, the yield is low, the chip is exposed to the environment for too long during the coupling process, the risk of contamination is high, it is not conducive to protecting the laser chip cavity surface, the shell is large, and the cost is also high. Summary of the invention

[0004] The purpose of the present invention is to provide a multi-chip packaged semiconductor laser to improve the above problems, integrating only necessary optical components into the housing, and placing other components that need further coupling and beam combining outside. The specific technical solution is as follows:

[0005] A multi-chip packaged semiconductor laser comprises a tube shell and a plurality of equally spaced step structures, a plurality of laser chips, and a plurality of collimating lenses arranged inside the tube shell, and also comprises a plurality of window pieces on the side wall of the tube shell, wherein the equally spaced step structures are fixed to the bottom of the tube shell for carrying and fixing the laser chips, the light emitting directions of the laser chips are the same, the collimating lenses are fixedly arranged at the front ends of the light emitting directions of the laser chips, the window pieces are fixedly arranged on the side wall of the tube shell and correspond one to one with the laser chips; the fast axis collimating lenses are used to collimate the outgoing laser of the laser chip, and the collimated laser is transmitted to the outside of the tube shell through the window pieces to form multi-path parallel light beams.

[0006] Furthermore, it also includes a relay heat sink, a first tube shell pin and a second tube shell pin, wherein the first tube shell pin and the second tube shell pin are fixedly arranged on a side wall of the tube shell opposite to the window sheet;

[0007] The laser chips are connected in series through metal leads, and both ends of the series connection are connected to the relay heat sink, and the relay heat sink is respectively connected to the first tube shell pin and the second tube shell pin through metal leads.

[0008] Furthermore, the equally spaced step structure is a plurality of steps of the same or different heights, the height difference of the steps can be set to 0-2 mm, the distances from the laser chips to the side walls of the tube shell are all equal, and the distance between adjacent laser chips can be set to 1-10 mm.

[0009] Furthermore, the laser chip is mounted on a heat-conducting substrate, and the heat-conducting substrate is welded or bonded to the equally spaced step structure;

[0010] The heat-conducting substrate is an alumina ceramic substrate or a silicon carbide ceramic substrate.

[0011] Furthermore, the welding adopts a vacuum reflow process, wherein the solder uses a gold-tin alloy or a tin-silver-copper alloy, and the welding temperature is 200-350°C.

[0012] Furthermore, the number of the plurality of laser chips may be set to be 2 to 20.

[0013] Furthermore, the wavelength of the laser emitted by the laser chip is 300-750 mm, and the wavelengths of the multiple laser chips may be the same or different.

[0014] Furthermore, the collimating lens includes at least one of an aspherical lens, a fast-axis and slow-axis integrated lens, a fast-axis collimating lens or a cylindrical lens.

[0015] Furthermore, the window piece may be a bandpass filter or a low-reflection filter, and the window piece is a circular window piece or a rectangular window piece.

[0016] Furthermore, it also includes a shell cover, which is welded and sealed with the top of the tube shell.

[0017] The multi-chip packaged semiconductor laser provided by the present invention has the following beneficial effects compared with the prior art:

[0018] 1. A multi-chip packaged semiconductor laser provided by the present invention is designed to carry different laser chips by designing step structures of different heights, which is beneficial to spatial coupling. The light emission directions of multiple laser chips are parallel, and the light beams are at the same height or increase or decrease on the vertical shell plane. The output is parallel light beams of unequal height or equal height, which are output to the outside through the window piece to form multi-path parallel light beams.

[0019] 2. The present invention provides a multi-chip packaged semiconductor laser, which reduces the slow-axis coupling lenses and reflectors in the packaging tube shell of the semiconductor laser, reduces the optical element coupling difficulty of the sealed shell, reduces the volume of the laser shell, reduces the heat transfer path, minimizes the sealed optical components and chips, improves product reliability, and further reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an overall internal schematic diagram of a multi-chip packaged semiconductor laser provided by the present invention;

[0021] Figure 2 It is a schematic diagram of the internal top view of a multi-chip packaged semiconductor laser provided by the present invention;

[0022] Figure 3 It is a schematic diagram of an external cover of a multi-chip packaged semiconductor laser provided by the present invention;

[0023] Figure 4 It is a typical optical path schematic diagram of a multi-chip packaged semiconductor laser provided by the present invention.

[0024] 001-tube shell, 002-laser chip, 003-fast axis collimator, 004-equally spaced step structure, 005-window, 006-relay heat sink, 007-first tube shell pin, 008-second tube shell pin, 009-metal lead, 010-shell cover. DETAILED DESCRIPTION

[0025] The following will be combined with the accompanying drawings provided by the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. According to the following description, the advantages and features of the present invention will be more clear. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0026] In the description of the present invention, unless otherwise clearly stipulated and limited, the terms "connection" and "connected" should be interpreted in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the description of the present invention, terms such as "up", "down", "left", "right", "front", "back", "center", "horizontal", "vertical", "top", "bottom", "inside" and "outside" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of description and simplification of operation, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0028] Example

[0029] This embodiment provides a multi-chip packaged semiconductor laser. Figure 1 As shown, the laser includes a tube shell 001 and a plurality of laser chips 002, a plurality of collimating lenses 003, a plurality of equally spaced step structures 004 and a relay heat sink 006 arranged inside the tube shell 001, and also includes a plurality of window pieces 005 and tube shell pins 007 and 008 arranged on the side wall of the tube shell 001. The laser chip 002, the relay heat sink 006 and the tube shell pins are electrically connected through metal leads 009.

[0030] A multi-chip packaged semiconductor laser provided by an embodiment of the present invention is provided with a plurality of laser chips and the light emission directions are parallel. The output lasers of the multi-channel laser chips are collimated by a collimating lens and output as parallel light beams of unequal heights or equal heights, which are output to the outside of the tube shell through a window piece to form multi-path parallel light beams.

[0031] The multi-chip packaged semiconductor laser is described in detail below.

[0032] As a specific implementation of multiple laser chips, the laser chip 002 is mounted on a heat-conducting substrate, and then bonded to the equally spaced step structure 004 by welding the heat-conducting substrate or bonding it with a high thermal conductivity adhesive. The equally spaced step structure 004 is fixed to the bottom of the tube shell 001, and the light emitting directions of all laser chips 002 face the same direction. The light-emitting surfaces of the laser chips 002 are located at the same position in the Y direction, that is, the distance from the light-emitting surface of each laser chip 002 to the side wall of the tube shell 001 is equal; according to the power of the laser chip 002, the spacing of the light-emitting surfaces of the laser chip 002 in the X direction can be set to 1 to 10 mm, that is, the distance between adjacent laser chips 002 is set to 1 to 10 mm, and according to the heat dissipation power, the laser chip spacing is preferably set to 3 to 6 mm; the spacing of the light-emitting surfaces of the laser chips 002 in the Z direction can be set to 0 to 2 mm, that is, the height difference between two adjacent steps of the equally spaced step structure 004 is set to 0 to 2 mm, preferably 0.1 to 0.5 mm.

[0033] Optionally, depending on the power of the laser chip 002, 2 to 20 laser chips may be selected and arranged in combination, and preferably 2 to 6 laser chips may be arranged according to the application.

[0034] Optionally, the wavelength of the laser chip 002 is 300-750 nm, preferably 450 nm, 520 nm or 620 nm.

[0035] Optionally, the thermally conductive substrate may be an alumina ceramic substrate or a silicon carbide ceramic substrate.

[0036] Optionally, the welding process uses vacuum reflow soldering, and multiple laser chips and relay heat sinks are fixed by a fixture. Considering the high thermal conductivity problem, the solder preferably uses gold-tin alloy or tin-silver-copper alloy, and the welding temperature is 200-350°C, preferably 280°C.

[0037] As a specific implementation of multiple collimating lenses, multiple collimating lenses 003 are correspondingly arranged at the front end of the light emitting direction of multiple laser chips, and are fixed by UV adhesive. The collimating lens 003 is used to couple the divergent light of the laser chip in the Z direction into a parallel light beam. The collimating lens 003 can use an aspheric lens, a fast-axis and slow-axis integrated lens, a fast-axis plano-convex lens, or a cylindrical lens of a small section of optical fiber, and the lenses used all need double-sided coating to reduce optical power loss and scattering into the cavity. According to the application, a fast-axis plano-convex lens is preferably used, and the distance between the fast-axis plano-convex lens and the laser chip is 0.3 mm, which is conducive to coupling and lens bonding.

[0038] As a specific implementation of multiple window pieces, multiple window pieces 005 are arranged on the side wall of the tube shell 001, corresponding to multiple laser chips 002 respectively. The number of window pieces is set according to the number of laser chips, and the laser beam collimated by the collimating lens can be output to the outside of the tube shell 001 through the window piece. The window piece can be a bandpass filter or a low-reflection filter, which is fixed by glass solder to ensure that the glass is less stressed at different temperatures of the product. The coating on the window piece is performed according to the wavelength, and generally requires that the transmittance of the laser chip working wavelength ±10nm is greater than 98%.

[0039] Optionally, the window piece is a circular window piece or a rectangular window piece, and a circular window piece is preferably used.

[0040] As a specific implementation of the tube shell pin 007 and the tube shell pin 008, the tube shell pin 007 and the tube shell pin 008 are arranged on the side wall of the tube shell 001 opposite to the window sheet 005. The tube shell pin 007 is the negative electrode of the direct current power supply, and the tube shell pin 008 is the positive electrode of the direct current power supply.

[0041] See also Figure 2As shown, multiple laser chips are connected in series through metal leads 009. After the series connection, one end is connected to the relay heat sink 006 through the metal lead 009 and then to the tube case pin 007, and the other end is connected to the relay heat sink 006 through the metal lead 009 and then to the tube case pin 008.

[0042] Optionally, the metal lead 009 includes a gold lead, an aluminum lead or a copper alloy lead, and the thickness of the metal lead 009 can be selected according to the current. Preferably, the connecting wires between the laser chips 002 use aluminum leads, and the connecting wires between the laser chip and the thermal conductive substrate use gold leads.

[0043] See also Figure 3 As shown, the laser also includes a shell cover 010, which seals the top of the tube shell 001. The tube shell 001 and the shell cover 010 are parallel sealed in nitrogen or dry air to keep the tube shell filled with dry air or nitrogen, while ensuring that the water vapor meets military standards.

[0044] See also Figure 4 The figure shows a schematic diagram of the optical path of a multi-chip packaged semiconductor laser provided by the present invention. The multiple laser chips provided in the laser have parallel light emission directions. Due to the different positions of the laser chips in the Z direction, the emitted light is collimated by a collimating lens and output as parallel beams of unequal height or equal height, which are output to the outside through a window piece to form multiple parallel beams of equal height or unequal height. The heat-generating packaging form of the present invention reduces the volume of the housing, reduces the heat transfer path, and minimizes the sealed optical components and chips, thereby improving product reliability and further reducing costs.

[0045] Those skilled in the art should understand that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the present invention. Based on the embodiments of the present invention, any changes and modifications made by ordinary technicians in the field of the present invention according to the above disclosure are within the scope of protection of the claims.

Claims

1. A multi-chip packaged semiconductor laser, characterized in that: It includes a tube shell and a plurality of equally spaced step structures, a plurality of laser chips, and a plurality of collimating lenses arranged inside the tube shell, and also includes a plurality of window pieces on the side wall of the tube shell. The equally spaced step structures are fixed to the bottom of the tube shell for supporting and fixing the laser chips. The light emitting directions of the laser chips are the same. The collimating lenses are fixedly arranged at the front ends of the light emitting directions of the laser chips. The window pieces are fixedly arranged on the side wall of the tube shell and correspond one to one with the laser chips. The fast axis collimating lenses are used to collimate the outgoing laser of the laser chip. The collimated laser is transmitted to the outside of the tube shell through the window pieces to form multi-path parallel light beams.

2. The multi-chip packaged semiconductor laser according to claim 1, characterized in that: It also includes a relay heat sink, a first tube shell pin and a second tube shell pin, wherein the first tube shell pin and the second tube shell pin are fixedly arranged on a side wall of the tube shell opposite to the window sheet; The laser chips are connected in series through metal leads, and both ends of the series connection are connected to the relay heat sink, and the relay heat sink is respectively connected to the first tube shell pin and the second tube shell pin through metal leads.

3. The multi-chip packaged semiconductor laser according to claim 2, characterized in that: The equally spaced step structure is a plurality of steps of the same or different heights, the height difference of the steps can be set to 0-2 mm, the distances from the laser chips to the side walls of the tube shell are all equal, and the distance between adjacent laser chips can be set to 1-10 mm.

4. The multi-chip packaged semiconductor laser according to claim 1, characterized in that: The laser chip is mounted on a heat-conducting substrate, and the heat-conducting substrate is welded or bonded to the equally spaced step structure; The heat-conducting substrate is an alumina ceramic substrate or a silicon carbide ceramic substrate.

5. The multi-chip packaged semiconductor laser according to claim 4, characterized in that: The welding adopts a vacuum reflow soldering process, wherein the solder uses a gold-tin alloy or a tin-silver-copper alloy, and the welding temperature is 200-350°C.

6. The multi-chip packaged semiconductor laser according to claim 1, characterized in that: The number of the plurality of laser chips may be set to be 2 to 20.

7. The multi-chip packaged semiconductor laser according to claims 1-6, characterized in that: The wavelength of the laser emitted by the laser chip is 300-750 nm, and the wavelengths of the multiple laser chips may be the same or different.

8. The multi-chip packaged semiconductor laser according to claim 7, characterized in that: The collimating lens includes at least one of an aspherical lens, a fast-axis and slow-axis integrated lens, a fast-axis collimating lens or a cylindrical lens.

9. The multi-chip packaged semiconductor laser according to claim 8, characterized in that: The window piece can be a bandpass filter or a low-reflection filter, and the window piece is a circular window piece or a rectangular window piece.

10. The multi-chip packaged semiconductor laser according to claim 9, characterized in that: It also includes a shell cover, which is welded and sealed with the top of the tube shell.

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