A semiconductor laser heat sink with a patterned structure and a manufacturing method thereof

Abstract

A semiconductor laser heat sink with a patterned structure and a manufacturing method thereof. A three-dimensional patterned structure array is pre-prepared on the upper and lower surfaces of a substrate, thereby greatly increasing the surface area and surface chemical bond energy of the substrate material, improving the adhesion of the functional layer, transition metal layer I and transition metal layer II in contact with the substrate material, and manufacturing a functional layer on the three-dimensional patterned structure array. The thermal conductivity or thermal expansion coefficient of the substrate material and the functional layer material are effectively combined to adjust the thermal conductivity or thermal expansion coefficient of the material as a whole, thereby reducing the thermal resistance of the heat sink material while ensuring a small thermal mismatch with the semiconductor laser material itself, improving the heat dissipation performance, and ensuring the photoelectric performance and reliability of the laser.

Description

Technical Field

[0001] The invention relates to the technical field of laser packaging, and in particular to a semiconductor laser heat sink with a patterned structure and a manufacturing method thereof. Background Art

[0002] Semiconductor laser chips are widely used in the fields of communication, processing, medicine, scientific research, sensing, etc. They have many advantages such as small size, high efficiency, light weight, long life, good process compatibility, etc. They have developed particularly rapidly in recent years, greatly promoting the development of related industries such as information, measurement, medical care, and entertainment. Due to the particularity of the device characteristics of semiconductor lasers themselves and the requirements of various applications, almost all semiconductor lasers (or bars) must undergo the chip packaging process before they can be put into production at the downstream application end. Since semiconductor lasers are typical electro-optical conversion chips, with the continuous improvement of the output power of semiconductor lasers, they are subject to the influence of electro-optical conversion efficiency. In addition to the part converted into effective optical power output, at least 30% of the electrical power is converted into invalid waste heat power, and this waste heat will in turn directly affect the output power, optical characteristics, reliability and other parameters of semiconductor lasers. Therefore, the actual performance of semiconductor laser chips in applications is closely related to their operating temperature and waste heat control. Heat dissipation issues have become a key factor directly affecting the performance of semiconductor lasers, especially high-power semiconductor lasers.

[0003] At present, the most commonly used heat dissipation method is to use heat sink materials to conduct away the waste heat generated by the semiconductor laser when it is working, thereby reducing the normal operating temperature of the device and ensuring the output performance and reliability of the device. Since the key requirements of semiconductor lasers in applications are concentrated on high power output, high beam quality, high reliability and low cost of use, the corresponding heat sink material development focuses on high thermal conductivity, matching thermal expansion coefficient and the lowest possible cost. The high thermal conductivity of the heat sink can dissipate the heat generated by the laser when it is working in time, and the matching thermal expansion coefficient ensures good optical properties and avoids damage to the chip or the heat sink itself due to thermal stress mismatch. The lowest possible cost ultimately ensures that it can be used faster and more widely in laser packaging.

[0004] From the above perspectives, the main materials used as semiconductor laser heat sinks today are copper tungsten (CuW), aluminum nitride (AlN) and beryllium oxide (BeO). For example, the invention patent with publication number CN 103413791 A uses AlN or BeO substrates to prepare heat sinks. The biggest advantage is that it has a thermal expansion coefficient close to that of existing GaAs semiconductor laser chips (~6.7′10 -6 / K), but the thermal conductivity of the material (170~270W m -1 K -1) are not high and some materials (BeO) themselves or in the preparation process contain highly toxic substances, which can no longer meet the urgent needs of high-power semiconductor laser heat dissipation, limiting the application of semiconductor lasers in high-end fields. In addition, because the welding process in semiconductor laser packaging requires that a multilayer metal alloy (including solder) must be prepared on the surface of the heat sink, the adhesion between the metal alloy and the heat sink substrate is significantly affected by the properties of the metal material itself and the specific process, and it is very easy to cause metal shedding problems caused by interface reasons such as process fluctuations or thermal mismatch. This patented technical solution uses ion implantation, sputtering technology and chemical plating or electroplating technology to try to solve the problem of surface metal firmness, but there are still problems such as the complex ion implantation process and the difficulty in ensuring the uniformity of large-size heat sink production. The cost of the sputtering process is significantly higher than that of traditional processes such as electron beam evaporation, and the materials prepared by chemical plating or electroplating have poor density and low purity.

[0005] In addition, as in the technical solution adopted by the invention patent CN 103887703 B, a high thermal conductivity graphene layer is used as the surface layer of the heat sink to improve the heat dissipation capacity of the laser. In theory, the thermal conductivity of graphene along the plane (parallel to the heat sink surface) is very high, but in the technical solution, since the graphene layer has only one or several atomic layers and the thickness is only tens of nanometers, compared with the hundreds of microns of the substrate itself, it has almost no effect on the thermal conductivity perpendicular to the heat sink surface. In addition, the surface graphene in the solution adopts a method of chemical vapor deposition, dissolution and then transfer, which is complicated and costly. Furthermore, graphene itself is a single atomic layer of graphite, that is, a layer of sp2-bonded carbon atoms arranged in a hexagonal or honeycomb lattice, so the interatomic strength within this layer of graphite atomic layer is relatively high, but as an intermediate layer, it is still an intermolecular force when combined with the upper and lower layers of materials, and the bonding force is relatively weak (similar to the interlayer force of graphite), so the graphene layer and its upper layer material are not easy to be firmly combined with the base material, and there is a greater possibility of accidental peeling. Summary of the invention

[0006] In order to overcome the deficiencies of the above technologies, the present invention provides a semiconductor laser heat sink with a patterned structure that improves interface firmness while taking into account the improvement of thermal conductivity and adjustment of thermal expansion coefficient of the sink material, meeting the overall application requirements of high-power semiconductor lasers for heat sink materials.

[0007] The technical solution adopted by the present invention to overcome the technical problems is:

[0008] A semiconductor laser heat sink with a patterned structure, comprising:

[0009] A substrate, wherein a plurality of three-dimensional graphic structures are arranged on the upper and lower end surfaces thereof along the plane direction to form a three-dimensional graphic structure array;

[0010] A transition metal layer I is disposed below the substrate, and covers the lower end of the three-dimensional pattern structure array below the substrate;

[0011] A transition metal layer II is disposed on the substrate, the transition metal layer II covers the upper end of the three-dimensional pattern structure array on the substrate, and an isolation groove is disposed on the transition metal layer II, the isolation groove divides the transition metal layer II into two independent areas;

[0012] The solder layer is disposed in an independent region above the transition metal layer II and / or on the transition metal layer I.

[0013] Preferably, the shape of the three-dimensional figure is a cylinder, a cone, a square table, a prism or an irregular three-dimensional figure, and the structure of the three-dimensional figure is convex or concave or alternating concave and convex.

[0014] Preferably, it further comprises a functional layer, wherein the functional layer is arranged above and / or below the substrate, and the functional layer covers the three-dimensional graphic structure array above and / or below the substrate.

[0015] Preferably, the outer diameter of the three-dimensional graphic structure is 10 nm-500 μm.

[0016] Preferably, the transition metal layer I is made of NiAu, NiPtAu, TiAu or TiPtAu material, and the thickness of the transition metal layer I is 1 μm-100 μm. The transition metal layer II is made of NiAu, NiPtAu, TiAu or TiPtAu material, and the thickness of the transition metal layer II is 1 μm-100 μm.

[0017] Preferably, the solder layer is made of In, AnSn, PbSn, or an adhesive containing Au or Ag.

[0018] Preferably, the functional layer is made of oxygen-free copper, AlN, SiC, diamond material or carbon nanomaterial, and the thickness of the functional layer is 20 nm-1 mm.

[0019] Preferably, the isolation groove is an L-shaped or I-shaped structure.

[0020] A method for manufacturing a semiconductor laser heat sink comprises the following steps:

[0021] a) After cleaning the substrate material wafer, a prefabricated surface mask pattern of the three-dimensional pattern structure required to be prepared on the upper and lower end surfaces of the substrate is manufactured through the steps of photoresist coating, photolithography, and development;

[0022] b) preparing a three-dimensional graphic structure on the upper and lower end surfaces of the substrate by chemical etching, or preparing a masking film by chemical and physical etching after depositing silicon oxide or silicon nitride, preparing a three-dimensional graphic structure by dry etching or laser etching, and removing the photoresist or masking film after the preparation is completed;

[0023] c) preparing a functional layer on the upper and / or lower end of the substrate material by evaporation, chemical vapor deposition, chemical plating or electroplating;

[0024] d) preparing transition metal layer I and transition metal layer II on the upper and lower end surfaces of the substrate material by photolithography, evaporation, chemical plating or electroplating, corrosion or stripping;

[0025] e) Slicing and separation are performed by saw blade machine, multi-wire cutting machine or laser cutting machine.

[0026] The beneficial effects of the present invention are as follows: a three-dimensional graphic structure array is pre-prepared on the upper and lower surfaces of the substrate, which greatly increases the surface area and surface chemical bond energy of the substrate material, improves the adhesion of the functional layer, transition metal layer I and transition metal layer II in contact with the substrate material, and manufactures the functional layer on the three-dimensional graphic structure array, effectively combining the respective characteristics of the thermal conductivity or thermal expansion coefficient of the substrate material and the functional layer material, and adjusting the thermal conductivity or thermal expansion coefficient of the material as a whole, thereby reducing the thermal resistance of the heat sink material while ensuring a small thermal mismatch with the semiconductor laser material itself, improving the heat dissipation performance, and ensuring the optoelectronic performance and reliability of the laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of a semiconductor laser heat sink according to Embodiment 1 of the present invention;

[0028] Figure 2 It is a schematic structural diagram of a semiconductor laser heat sink according to Embodiment 2 of the present invention;

[0029] In the figure, 100. semiconductor laser 101. In solder layer 102. TiAu transition metal layer 103. diamond functional layer 104. AlN substrate 105. NiAu transition metal layer 106. metal wire 107. isolation groove 108. cylindrical array 200. semiconductor laser 201. AnSn solder layer 202. TiPtAu transition metal layer 203. oxygen-free copper functional layer 204. SiC substrate 205. NiPtAu transition metal layer 206. metal wire 207. isolation groove 208. graphic array. DETAILED DESCRIPTION

[0030] The following is combined with Figure 1 , Attachment Figure 2 The present invention is further described.

[0031] A semiconductor laser heat sink with a patterned structure comprises: a substrate, on which the upper and lower end surfaces are respectively provided with a plurality of three-dimensional pattern structures arranged along the plane direction to form a three-dimensional pattern structure array; a transition metal layer I, arranged below the substrate, and covering the lower end of the three-dimensional pattern structure array below the substrate; a transition metal layer II, arranged above the substrate, and covering the upper end of the three-dimensional pattern structure array above the substrate, wherein an isolation groove is arranged on the transition metal layer II, and the isolation groove divides the transition metal layer II into two mutually independent regions; and a solder layer, arranged in an independent region above the transition metal layer II and / or arranged on the transition metal layer I. A three-dimensional pattern structure array is prepared in advance on the upper and lower surfaces of the substrate, which greatly increases the surface area and surface chemical bond energy of the substrate material, improves the adhesion of the transition metal layer I or the transition metal layer II in contact with the substrate material, improves the overall thermal conductivity and adjusts the thermal expansion coefficient of the material as a whole, reduces the thermal resistance of the heat sink material under the premise of ensuring a small thermal mismatch with the semiconductor laser material itself, improves the heat dissipation performance, and ensures the optoelectronic performance and reliability of the laser.

[0032] Preferably, the shape of the three-dimensional figure is a cylinder, a cone, a square table, a prism or an irregular three-dimensional figure, and the structure of the three-dimensional figure is convex or concave or alternating concave and convex.

[0033] Preferably, it also includes a functional layer, which is arranged above and / or below the substrate, and covers the three-dimensional pattern structure array above and / or below the substrate. By manufacturing the functional layer on the three-dimensional pattern structure array, the thermal conductivity or thermal expansion coefficient of the substrate material and the functional layer material are effectively combined to improve the overall thermal conductivity and adjust the thermal expansion coefficient of the material as a whole.

[0034] Preferably, the outer diameter of the three-dimensional graphic structure is 10 nm-500 μm.

[0035] Preferably, the transition metal layer I is made of NiAu, NiPtAu, TiAu or TiPtAu material, and the thickness of the transition metal layer I is 1 μm-100 μm. The transition metal layer II is made of NiAu, NiPtAu, TiAu or TiPtAu material, and the thickness of the transition metal layer II is 1 μm-100 μm.

[0036] Preferably, the solder layer is made of In, AnSn, PbSn, or an adhesive containing Au or Ag.

[0037] Preferably, the functional layer is made of oxygen-free copper, AlN, SiC, diamond material or carbon nanomaterial, and the thickness of the functional layer is 20 nm-1 mm.

[0038] Preferably, the isolation groove is an L-shaped or I-shaped structure.

[0039] The present invention also relates to a method for manufacturing a semiconductor laser heat sink, comprising the following steps:

[0040] a) After cleaning the substrate material wafer, a prefabricated surface mask pattern of the three-dimensional pattern structure required to be prepared on the upper and lower end surfaces of the substrate is manufactured through the steps of photoresist coating, photolithography, and development;

[0041] b) preparing a three-dimensional graphic structure on the upper and lower end surfaces of the substrate by chemical etching, or preparing a masking film by chemical and physical etching after depositing silicon oxide or silicon nitride, preparing a three-dimensional graphic structure by dry etching or laser etching, and removing the photoresist or masking film after the preparation is completed;

[0042] c) preparing a functional layer on the upper and / or lower end of the substrate material by evaporation, chemical vapor deposition, chemical plating or electroplating;

[0043] d) preparing transition metal layer I and transition metal layer II on the upper and lower end surfaces of the substrate material by photolithography, evaporation, chemical plating or electroplating, corrosion or stripping;

[0044] e) Use a saw blade machine, a multi-wire cutting machine or a laser cutting machine to cut and separate, and ensure that the side used for positioning the semiconductor laser chip is smooth and flat and approximately perpendicular to the heat sink surface.

[0045] The above steps can achieve large-scale mass production through mature semiconductor process technologies such as lithography and evaporation, which can effectively improve the product qualification rate, reduce unit cost, facilitate product quality control and rapid industrialization.

[0046] The present invention will be further described below by two specific embodiments:

[0047] Embodiment 1:

[0048] As attached Figure 1The semiconductor laser heat sink with a patterned structure shown in the figure comprises: an AlN substrate 104, wherein the upper and lower end surfaces of the AlN substrate 104 are respectively provided with a plurality of three-dimensional patterned structures of nano-scale cylindrical protrusions arranged along the plane direction to form a cylindrical array 108; a NiAu transition metal layer 105 made of NiAu material, arranged below the AlN substrate 104, and the NiAu transition metal layer 105 covers the lower end of the cylindrical array 108 below the AlN substrate 104; a diamond functional layer 103 made of a high thermal conductivity diamond material, arranged above the AlN substrate 104, and the diamond functional layer 103 covers the AlN substrate 104. The upper end of the cylindrical array 108 above the substrate 104; a TiAu transition metal layer 102 made of TiAu material, arranged above the diamond functional layer 103, and an L-shaped isolation groove 107 is arranged on the TiAu transition metal layer 102, and the isolation groove 107 divides the TiAu transition metal layer 102 into two independent regions; a semiconductor laser 100, one side electrode of which is welded to an independent region of the TiAu transition metal layer 102 through an In solder layer 101, and the other side electrode of which is connected to another independent region of the TiAu transition metal layer 102 through a metal wire 106.

[0049] The thickness of the TiAu transition metal layer 102 is 100nm-2μm, the thickness of the AlN substrate 104 is 50μm-1mm, the diameter of the cylinders of the cylinder array 108 is between 10nm-500nm, and the height is between 10nm-500nm. The diamond functional layer 103 is a polycrystalline material with a thickness of 1μm-100μm, and the thickness of the NiAu transition metal layer 105 is 100nm-2μm.

[0050] This embodiment uses AlN as the matrix material to ensure the thermal expansion coefficient matching that of the GaAs semiconductor laser; and through the surface nano-cylinder array 108, a strong bond between the high thermal conductivity diamond functional layer 103 deposited on the surface and the NiAu transition metal layer 105 is achieved, and the high thermal conductivity diamond layer 103 achieves the effect of improving the overall thermal conductivity of the composite heat sink.

[0051] Embodiment 2:

[0052] As attached Figure 2The semiconductor laser heat sink with a patterned structure shown in the figure includes: a SiC substrate 204, on which the upper and lower end surfaces are respectively arranged with a plurality of micrometer-level cubic protrusions in a plane direction to form a pattern array 208; a NiPtAu transition metal layer 205 made of NiPtAu material, arranged below the SiC substrate 204, and the NiPtAu transition metal layer 205 covers the lower end of the pattern array 208 below the SiC substrate 204; an oxygen-free copper functional layer 203 made of oxygen-free copper material, arranged above the SiC substrate 204, and the oxygen-free copper functional layer 203 covers the upper part of the SiC substrate 204 The graphic array 208 is at the upper end of the array; a TiPtAu transition metal layer 202 made of TiPtAu material is arranged above the oxygen-free copper functional layer 203, and an L-shaped isolation groove 207 is arranged on the TiPtAu transition metal layer 202, and the isolation groove 207 divides the TiPtAu transition metal layer 202 into two independent areas; a semiconductor laser 200, one side electrode of which is welded to an independent area of ​​the TiPtAu transition metal layer 202 through an AnSn solder layer 201, and the other side electrode of which is connected to another independent area of ​​the TiPtAu transition metal layer 202 through a metal wire 206.

[0053] The thickness of TiPtAu transition metal layer 202 is 100nm-2μm, the thickness of semi-insulating SiC substrate 204 is 50μm-1mm, the side length of the cube of graphic array 208 is between 1μm-500μm, the height is between 1μm-100μm, the oxygen-free copper functional layer 203 is single crystal material with a thickness of 1μm-100μm, and the NiPtAu transition metal layer 205 is 100nm-2μm.

[0054] This embodiment uses semi-insulating SiC as the base material and has a high power consumption of up to 400W m -1 K -1 The above thermal conductivity ensures the efficient heat dissipation requirement of the packaged semiconductor laser 200; and through the firm bonding between the graphic array 208 and the oxygen-free copper functional layer 203 and the NiPtAu transition metal layer 205; in addition, by adjusting the density and size of the graphic array 208 and the thickness of the oxygen-free copper functional layer 203 with a higher thermal expansion coefficient, the thermal expansion coefficient of the composite heat sink material can be fine-tuned to match it with the semiconductor laser 200.

Claims

1. A semiconductor laser heat sink with a patterned structure, characterized in that: include: A substrate, wherein a plurality of three-dimensional graphic structures are arranged on the upper and lower end surfaces thereof along the plane direction to form a three-dimensional graphic structure array; A transition metal layer I is disposed below the substrate, and covers the lower end of the three-dimensional pattern structure array below the substrate; A transition metal layer II is disposed on the substrate, the transition metal layer II covers the upper end of the three-dimensional pattern structure array on the substrate, and an isolation groove is disposed on the transition metal layer II, the isolation groove divides the transition metal layer II into two independent areas; A solder layer disposed in a separate region above the transition metal layer II and / or disposed on the transition metal layer I; It also includes a functional layer, which is arranged above and / or below the substrate, and covers the three-dimensional graphic structure array above and / or below the substrate.

2. The semiconductor laser heat sink with a patterned structure according to claim 1, characterized in that: The shape of the three-dimensional figure is a cylinder, a cone, a square table, a prism or an irregular three-dimensional figure, and the structure of the three-dimensional figure is convex or concave or staggered concave and convex.

3. The semiconductor laser heat sink with a patterned structure according to claim 1, characterized in that: The outer diameter of the three-dimensional graphic structure is 10nm-500μm.

4. The semiconductor laser heat sink with a patterned structure according to claim 1, characterized in that: The transition metal layer I is made of NiAu, NiPtAu, TiAu or TiPtAu material, and has a thickness of 1 μm-100 μm. The transition metal layer II is made of NiAu, NiPtAu, TiAu or TiPtAu material, and has a thickness of 1 μm-100 μm.

5. The semiconductor laser heat sink with a patterned structure according to claim 1, characterized in that: The solder layer is made of In, AnSn, PbSn, or an adhesive containing Au or Ag.

6. The semiconductor laser heat sink with a patterned structure according to claim 1, characterized in that: The functional layer is made of oxygen-free copper, AlN, SiC, diamond material or carbon nanomaterial, and the thickness of the functional layer is 20nm-1mm.

7. The semiconductor laser heat sink with a patterned structure according to claim 1, characterized in that: The isolation groove is an L-shaped or I-shaped structure.

8. A method for manufacturing a semiconductor laser heat sink as claimed in claim 1, characterized in that: The steps include: a) After cleaning the substrate material wafer, a prefabricated surface mask pattern of the three-dimensional pattern structure required to be prepared on the upper and lower end surfaces of the substrate is manufactured through the steps of photoresist coating, photolithography, and development; b) preparing a three-dimensional graphic structure on the upper and lower end surfaces of the substrate by chemical etching, or preparing a masking film by chemical and physical etching after depositing silicon oxide or silicon nitride, preparing a three-dimensional graphic structure by dry etching or laser etching, and removing the photoresist or masking film after the preparation is completed; c) preparing a functional layer on the upper and / or lower end of the substrate material by evaporation, chemical vapor deposition, chemical plating or electroplating; d) preparing transition metal layer I and transition metal layer II on the upper and lower end surfaces of the substrate material by photolithography, evaporation, chemical plating or electroplating, corrosion or stripping; e) Slicing and separation are performed by saw blade machine, multi-wire cutting machine or laser cutting machine.

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