A method of welding a slat laser gain medium module

Abstract

The application provides a soldering method of a slab laser gain medium module, which comprises the following steps: pre-treating relevant materials; setting a first diamond soldering transition sheet on one side of a first heat sink and performing soldering treatment to form a first soldering body; setting a second diamond soldering transition sheet on one side of a second heat sink and performing soldering treatment to form a second soldering body; setting a slab laser gain medium between one side of the first soldering body close to the first diamond soldering transition sheet and one side of the second soldering body close to the second diamond soldering transition sheet and performing soldering treatment. The application adds a diamond transition sheet with good heat conductivity between the slab laser gain medium and the soldering layer of the heat sink by adopting a cold pressure soldering pre-treatment method, improves the heat dissipation of the laser gain medium during work, reduces the thermal stress of the soldering layer of the laser gain medium and the heat sink, and improves the beam quality and reliability of the slab laser gain medium module.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gain medium module packaging process of solid-state laser, and particularly relates to a soldering method of slab laser gain medium module. BACKGROUND

[0002] Under high power conditions, thermal focusing, thermal-induced birefringence and thermal depolarization effects occur in solid-state laser gain medium, which results in the decrease of output power and the degradation of beam quality. The slab gain medium laser adopts zigzag light path propagation, which can eliminate thermal-induced wavefront distortion, and greatly improves the output power of solid-state laser. However, the beam quality of the slab gain medium laser is poor due to the influence of factors such as spatial resolution and response bandwidth of the deformable mirror. To solve this problem, the thermal effect of the slab gain medium module must be improved. By improving the soldering method of the slab laser gain medium module, the heat dissipation efficiency of the laser gain medium is improved, the soldering stress is reduced, and the beam quality of the slab gain medium laser is improved. SUMMARY

[0003] The technical problem to be solved by the present application is the thermal effect of the slab gain medium module, which results in poor beam quality of the slab gain medium laser. In view of this, the present application provides a soldering method of slab laser gain medium module.

[0004] The technical solution adopted by the present application is that the soldering method of the slab laser gain medium module comprises: sequentially performing pretreatment on the slab laser gain medium, the first heat sink, the second heat sink, the first diamond soldering transition piece and the second diamond soldering transition piece before soldering; setting the first diamond soldering transition piece on one side of the first heat sink and performing soldering treatment to form a first soldering body, setting the second diamond soldering transition piece on one side of the second heat sink and performing soldering treatment to form a second soldering body; and setting the slab laser gain medium between one side of the first soldering body close to the first diamond soldering transition piece and one side of the second soldering body close to the second diamond soldering transition piece and performing soldering treatment.

[0005] In one embodiment, the sequentially performing pretreatment on the slab laser gain medium, the first heat sink, the second heat sink, the first diamond soldering transition piece and the second diamond soldering transition piece before soldering comprises: sequentially plating titanium film and gold film on two surfaces of the first diamond soldering transition piece and the second diamond soldering transition piece; sequentially plating optical film, titanium film and gold film on two surfaces of the slab laser gain medium; and sequentially plating gold film and indium film on the soldering surfaces of the first heat sink and the second heat sink, wherein the first heat sink and the second heat sink are copper heat sinks with micro-channel water cooling structure inside.

[0006] In one embodiment, the disposing the first diamond solder transition piece on one side of the first heat sink and soldering to form a first solder body, and disposing the second diamond solder transition piece on one side of the second heat sink and soldering to form a second solder body, comprises: placing the first diamond solder transition piece and the first heat sink into a vacuum diffusion furnace, vacuumizing the vacuum diffusion furnace before soldering, the vacuum degree being 1x10 -3 ~ 4x10 -4 Pa, pressurizing during soldering, the pressure being set to 500 lb ~ 2000 lb, the time being 10 h ~ 30 h, and taking out the first solder body from the vacuum diffusion furnace after soldering; and plating an indium film on the surface of the first diamond solder transition piece side of the first solder body. Placing the second diamond solder transition piece and the second heat sink into a vacuum diffusion furnace, vacuumizing the vacuum diffusion furnace before soldering, the vacuum degree being 1x10 -3 ~ 4x10 -4 Pa, pressurizing during soldering, the pressure being set to 500 lb ~ 2000 lb, the time being 10 h ~ 30 h, and taking out the second solder body from the vacuum diffusion furnace after soldering; and plating an indium film on the surface of the second diamond solder transition piece side of the second solder body.

[0007] In one embodiment, the disposing the slab laser gain medium between the first solder body near the first diamond solder transition piece and the second solder body near the second diamond solder transition piece and soldering, comprises: placing the first diamond solder transition piece upward the first solder body, the slab laser gain medium, the second diamond solder transition piece downward the second solder body in turn from bottom to top; placing the current device into a vacuum soldering furnace, vacuumizing the vacuum soldering furnace to 1x10 -3 ~ 3x10 -4 Pa before soldering, the soldering temperature being 200 ℃ ~ 260 ℃, and stopping heating after holding for 10 ~ 30 minutes, and cooling to room temperature in vacuum, and taking out the current device from the vacuum furnace, and completing the soldering process of the device.

[0008] In one embodiment, the slab laser gain medium comprises: a slab laser crystal doped with Nd 3+ , a slab laser ceramic doped with Nd 3+ , a slab laser crystal doped with Yb 3+ , or a slab laser ceramic doped with Yb 3+ .

[0009] In one embodiment, the opposite welding surfaces of the first heat sink, the second heat sink, the slab laser gain medium, the first diamond welding transition sheet and the second diamond welding transition sheet are required to reach: cleanliness≤0.1mg / cm 2 , flatness≤0.5λ, λ=632.8nm, and surface roughness≤40 / 20.

[0010] In one embodiment, the thickness of the first diamond sheet welding transition sheet and the second diamond sheet welding transition sheet is 0.1-2mm; and the welding length of the first diamond sheet welding transition sheet and the second diamond sheet welding transition sheet is the same as the welding length of the slab laser gain medium, and the welding width is 2mm larger than the welding width of the slab laser gain medium.

[0011] In one embodiment, the optical film on the surface of the slab laser gain medium is a silicon dioxide film with a thickness of 2-5μm; the titanium film has a thickness of 100-500nm, and the gold film has a thickness of 300-800nm; the size of the slab laser gain medium is: length 10-300mm, width 10-60mm, and thickness 1-5mm.

[0012] In one embodiment, the gold film of the first heat sink and the second heat sink has a thickness of 300-500nm, and the indium film has a thickness of 10-200μm.

[0013] In one embodiment, the titanium film of the first diamond sheet welding transition sheet and the second diamond sheet welding transition sheet has a thickness of 100-500nm, the gold film has a thickness of 300-800nm, and the indium film has a thickness of 10-200μm.

[0014] By using the above technical solution, the present application has at least the following advantages:

[0015] The welding method of the slab laser gain medium module according to the present application is a low-stress packaging method for the slab laser gain medium. By using the cold pressure welding pretreatment method, a diamond transition sheet with good thermal conductivity is added between the welding layer of the slab laser gain medium and the heat sink, thereby improving the heat dissipation of the laser gain medium during operation, reducing the thermal stress of the welding layer of the laser gain medium and the heat sink, and improving the beam quality and reliability of the slab laser gain medium module. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The welding method flow chart of the slab laser gain medium module according to the embodiment of the present application;

[0017] Figure 2 The schematic diagram of the composition structure of the slab laser gain medium module according to the embodiment of the present application;

[0018] Figure 3 A schematic diagram of an electronic device according to an embodiment of the present application.

[0019] Reference signs

[0020] 1 - first heat sink, 2 - first solder layer, 3 - first diamond solder transition piece, 4 - second solder layer, 5 - slab laser gain medium, 6 - third solder layer, 7 - second diamond solder transition piece, 8 - fourth solder layer, 9 - second heat sink. DETAILED DESCRIPTION

[0021] In order to further clarify the technical means and effects of the present application for achieving the predetermined purposes, the present application will be described in detail below with reference to the accompanying drawings and preferred embodiments.

[0022] The description of the method flow in the specification of the present application and the steps of the flowchart in the drawings of the present application do not necessarily strictly follow the step numbers, and the method steps can change the execution order. Moreover, certain steps can be omitted, multiple steps can be combined into one step for execution, and / or one step can be divided into multiple steps for execution.

[0023] A first embodiment of the present application is a slab laser gain medium module welding method, as shown in Figure 1 , comprising the following specific steps:

[0024] Step S1, sequentially pre-treat the slab laser gain medium, the first heat sink, the second heat sink, the first diamond solder transition piece, and the second diamond solder transition piece before welding.

[0025] Step S2, set the first diamond solder transition piece on one side of the first heat sink and perform soldering treatment to form a first solder body, and set the second diamond solder transition piece on one side of the second heat sink and perform soldering treatment to form a second solder body;

[0026] Step S3, set the slab laser gain medium between the side of the first solder body close to the first diamond solder transition piece and the side of the second solder body close to the second diamond solder transition piece, and perform soldering treatment.

[0027] The present embodiment will be described in detail in the following steps.

[0028] Step S1, sequentially pre-treat the slab laser gain medium, the first heat sink, the second heat sink, the first diamond solder transition piece, and the second diamond solder transition piece before welding.

[0029] In the present embodiment, the two surfaces of the first diamond solder transition piece and the second diamond solder transition piece are sequentially plated with titanium film and gold film.

[0030] In this embodiment, the two surfaces of the slab laser gain medium are sequentially plated with optical film, titanium film and gold film.

[0031] In this embodiment, the welding surfaces of the first heat sink and the second heat sink are sequentially plated with gold film and indium film.

[0032] The first heat sink and the second heat sink are copper heat sinks with micro-channel water cooling structure inside.

[0033] Specifically, the optical film on the surface of the slab laser gain medium is silicon dioxide film with a thickness of 2-5 μm; the titanium film has a thickness of 100-500 nm, and the gold film has a thickness of 300-800 nm; the size of the slab laser gain medium is: length 10-300 mm, width 10-60 mm, and thickness 1-5 mm.

[0034] Specifically, the gold film on the first heat sink and the second heat sink has a thickness of 300-500 nm, and the indium film has a thickness of 10-200 μm.

[0035] Specifically, the titanium film on the first diamond welding transition piece and the second first diamond welding transition piece has a thickness of 100-500 nm, and the gold film has a thickness of 300-800 nm.

[0036] In addition, in some possible embodiments of the present embodiment, the slab laser gain medium can be Nd 3+ doped slab laser crystal, Nd 3+ doped slab laser ceramic, Yb 3+ doped slab laser crystal, or Yb 3+ doped slab laser ceramic.

[0037] In step S2, the first diamond welding transition piece is arranged on one side of the first heat sink and welded to form a first welding body, and the second diamond welding transition piece is arranged on one side of the second heat sink and welded to form a second welding body.

[0038] In this embodiment, the first diamond welding transition piece and the first heat sink are placed in a vacuum diffusion furnace, the vacuum diffusion furnace is evacuated before welding, the vacuum degree is 1×10 -3 -4×10 -4 Pa, pressure is applied during welding, the pressure is set to 500 lb-2000 lb, the time is 10 h-30 h, and the first welding body obtained after welding is taken out of the vacuum diffusion furnace. After the above welding process is completed, an indium film is plated on the surface of the first diamond welding transition piece on the first welding body.

[0039] The second diamond welding transition piece and the second heat sink are placed in a vacuum diffusion furnace, the vacuum diffusion furnace is evacuated before welding, the vacuum degree is 1×10-3 ~ 4 x 10 -4 Pa, the welding pressure is set to 500 lb ~ 2000 lb, the time is 10 h ~ 30 h, and the second welding body is taken out of the vacuum diffusion furnace after the welding is completed;

[0040] After the above welding process is completed, an indium film is plated on the surface of the second diamond welding transition piece side of the second welding body.

[0041] In this embodiment, the thickness of the indium film is 10 ~ 200 μm.

[0042] It should be noted that the above welding process of first welding body first and then second welding body is only exemplary, and in actual application, the welding process of first welding body and second welding body can also be performed simultaneously, or the welding process of second welding body is performed first, and then the welding process of first welding body, which will not be limited herein.

[0043] Step S3, the slab laser gain medium is arranged between the side of the first welding body close to the first diamond welding transition piece and the side of the second welding body close to the second diamond welding transition piece, and a welding process is performed.

[0044] In this embodiment, the first welding body upward of the first diamond welding transition piece, the slab laser gain medium, and the second welding body downward of the second diamond welding transition piece are sequentially placed from bottom to top.

[0045] Similarly, the second welding body upward of the second diamond welding transition piece, the slab laser gain medium, and the first welding body downward of the first diamond welding transition piece can also be sequentially placed from bottom to top.

[0046] The current device is placed in the vacuum welding furnace, and the vacuum welding furnace is evacuated to 1 x 10 -3 ~ 3 x 10 - 4 Pa, the welding temperature is 200 °C ~ 260 °C, the holding time is 10 ~ 30 minutes, the heating is stopped, the cooling is performed under vacuum to room temperature, the current device is taken out of the vacuum furnace, and the welding process of the device is completed.

[0047] In this embodiment, the opposite welding surfaces of the first heat sink, the second heat sink, the slab laser gain medium, the first diamond welding transition piece, and the second diamond welding transition piece need to meet the following requirements: cleanliness ≤ 0.1 mg / cm 2 , flatness ≤ 0.5 λ, λ = 632.8 nm, and surface roughness ≤ 40 / 20.

[0048] In the embodiment, the thickness of the first diamond welding transition piece and the second diamond welding transition piece is 0.1-2mm; and the welding length of the first diamond welding transition piece and the second diamond welding transition piece is the same as the welding length of the slab laser gain medium, and the welding width is 2mm larger than the welding width of the slab laser gain medium.

[0049] Compared with the prior art, the low-stress welding method of the slab laser gain medium provided by the embodiment is a low-stress packaging method for the slab laser gain medium, which adds a diamond transition piece with good thermal conductivity between the slab laser gain medium and the welding layer of the heat sink by using a cold pressure welding pretreatment method, improves the heat dissipation of the laser gain medium during operation, reduces the thermal stress of the welding layer of the laser gain medium and the heat sink, and improves the beam quality and reliability of the slab laser gain medium module.

[0050] The second embodiment of the present application corresponds to the first embodiment, and the embodiment introduces a slab laser gain medium module, as shown in Figure 2 The slab laser gain medium module includes the following components:

[0051] The first heat sink 1, the first welding layer 2, the first diamond welding transition piece 3, the second welding layer 4, the slab laser gain medium 5, the third welding layer 6, the second diamond welding transition piece 7, the fourth welding layer 8, and the second heat sink 9.

[0052] The slab laser gain medium module provided by the embodiment is prepared by the low-stress welding method of the slab laser gain medium of the first embodiment, which is based on the same design idea as the first embodiment, and will not be described here.

[0053] The third embodiment of the present application, as shown in Figure 3 An electronic device can be understood as a physical device, and the electronic device includes the slab laser gain medium module as described in the second embodiment.

[0054] The fourth embodiment of the present application is based on the above embodiments, and introduces an application example of the present application.

[0055] The slab laser gain medium 5 is an Nd:YAG slab laser ceramic with a size of 140mmx20mmx2mm, an optical film thickness of the Nd:YAG slab laser ceramic of 3μm, a titanium film thickness of 300nm, and a gold film thickness of 800nm. The size of the first diamond welding transition piece 3 and the second diamond welding transition piece 7 is 134mmx22mmx10μm, the surface titanium film thickness is 100nm, and the gold film thickness is 300nm. The gold film thickness of the first heat sink 1 and the second heat sink 9 is 800nm, and the size of the indium film is 134mmx22mmx0.8mm.

[0056] Place the first heat sink 1 with the welding surface upward, the first diamond welding transition sheet 3 upward in sequence from bottom to top, and obtain the first welding body by welding.

[0057] Put the first welding body into the vacuum diffusion furnace, and perform vacuumization on the vacuum welding furnace before welding, and the vacuum degree is 4x10 -4 Pa, and the pressure is set to 2000lb, the pressure time is 20h, and the first welding body is taken out of the vacuum diffusion furnace after the pressure welding is completed; and the indium film is plated on the surface of the first diamond welding transition sheet 3 of the first welding body.

[0058] Place the second heat sink 9 with the welding surface upward, the second diamond welding transition sheet 7 upward in sequence from bottom to top, and obtain the second welding body by welding.

[0059] Put the second welding body into the vacuum diffusion furnace, and perform vacuumization on the vacuum welding furnace before welding, and the vacuum degree is 4x10 -4 Pa, and the pressure is set to 2000lb, the pressure time is 20h, and the second welding body is taken out of the vacuum diffusion furnace after the pressure welding is completed; and the indium film is plated on the surface of the second diamond welding transition sheet 7 of the second welding body.

[0060] Place the first welding body with the welding surface upward, the slab laser gain medium 5, and the second welding body with the welding surface downward in sequence from bottom to top; place the above-mentioned device combination into the vacuum welding furnace, perform vacuumization on the vacuum welding furnace before welding, and the vacuum degree is 3x10 -4 Pa, the welding temperature is 220 DEG C, the holding time is 10 minutes, the heating power is turned off, the device is taken out of the vacuum furnace in the vacuum state, and the welding process is completed.

[0061] In the fifth embodiment of the application, another application example of the application is introduced on the basis of the above-mentioned embodiments.

[0062] The slab laser gain medium 5 is Nd:YAG slab laser ceramic, and the size is 68mmx10mmx2mm, the optical film thickness of the Nd:YAG slab laser ceramic is 3um, the titanium film thickness is 100nm, and the gold film thickness is 300nm. The size of the first diamond welding transition sheet 3 and the second diamond welding transition sheet 7 is 62mmx10mmx10um, the titanium film thickness on the surface is 100nm, and the gold film thickness is 300nm. The gold film thickness of the first heat sink 1 and the second heat sink 9 is 300nm, and the size of the indium film is 62mmx10mmx0.5mm.

[0063] Place the first heat sink 1 with the welding surface upward, the first diamond welding transition sheet 3 upward in sequence from bottom to top, and obtain the first welding body by welding.

[0064] The first welding body is placed in a vacuum diffusion furnace, the vacuum welding furnace is vacuumized before welding, the vacuum degree is 4×10 -4 Pa, the first welding body is pressurized, the pressure is set to 500 lb, the pressurizing time is 10 h, after the press welding is finished, the first welding body is taken out of the vacuum diffusion furnace; an indium film is plated on the surface of the first diamond welding transition piece 3 of the first welding body.

[0065] The second heat sink 9 with the welding surface upward, the second diamond welding transition piece 7 are placed in turn from bottom to top, and the second welding body is obtained by welding.

[0066] The second welding body is placed in a vacuum diffusion furnace, the vacuum welding furnace is vacuumized before welding, the vacuum degree is 4×10 -4 Pa, the second welding body is pressurized, the pressure is set to 500 lb, the pressurizing time is 10 h, after the press welding is finished, the second welding body is taken out of the vacuum diffusion furnace; an indium film is plated on the surface of the second diamond welding transition piece 7 of the second welding body.

[0067] The first welding body with the welding surface upward, the slab laser gain medium 5, the second welding body with the welding surface downward are placed in turn from bottom to top; the above device combination is placed in a vacuum welding furnace, the vacuum welding furnace is vacuumized before welding to 3×10 -4 Pa, the welding temperature is 200 DEG C, after the heat preservation is 10 minutes, the heating power is turned off, the cooling is carried out under the vacuum state to the room temperature, the device is taken out of the vacuum furnace, and the welding process is finished.

[0068] In summary, compared with the prior art, the present application has at least the following beneficial effects:

[0069] 1) The present application is a low-stress packaging method for a slab laser gain medium, a diamond transition piece with good thermal conductivity is added between the welding layer of the slab laser gain medium and the heat sink by adopting a cold press welding pretreatment method, the heat dissipation of the laser gain medium during work is improved, the thermal stress of the welding layer of the laser gain medium and the heat sink is reduced, and the beam quality and reliability of the slab laser gain medium module are improved.

[0070] 2) The present application is simple to operate and easy to implement.

[0071] Through the description of the specific embodiments, the technical means and effects adopted by the present application to achieve the predetermined purpose can be more deeply and specifically understood, however, the accompanying drawings are only provided for reference and description, and are not used to limit the present application.

Claims

1. A welding method for a slab laser gain medium module, characterized in that: include: Pre-treating the slab laser gain medium, the first heat sink, the second heat sink, the first diamond welding transition piece, and the second diamond welding transition piece in sequence before welding; The first diamond welding transition piece is disposed on one side of the first heat sink and welded to form a first welded body, and the second diamond welding transition piece is disposed on one side of the second heat sink and welded to form a second welded body; Disposing the slab laser gain medium between a side of the first welding body close to the first diamond welding transition piece and a side of the second welding body close to the second diamond welding transition piece, and performing a welding process; The pre-treatment of the slab laser gain medium, the first heat sink, the second heat sink, the first diamond welding transition piece, and the second diamond welding transition piece before welding in sequence includes: Sequentially coating both surfaces of the first diamond welding transition piece and the second diamond welding transition piece with a titanium film and a gold film; sequentially coating the two surfaces of the slab laser gain medium with an optical film, a titanium film, and a gold film; Sequentially plating the welding surfaces of the first heat sink and the second heat sink with a gold film and an indium film, wherein the first heat sink and the second heat sink are copper heat sinks with a microchannel water cooling structure inside; The method of disposing the first diamond welding transition piece on one side of the first heat sink and performing a welding process to form a first welding body, and disposing the second diamond welding transition piece on one side of the second heat sink and performing a welding process to form a second welding body, includes: The first diamond welding transition piece and the first heat sink are placed in a vacuum diffusion furnace. Before welding, the vacuum welding furnace is evacuated to a vacuum degree of 1× ~4× Pa, pressurizing during welding, the pressure is set to 500 lb to 2000 lb, the time is 10 h to 30 h, and after the welding is completed, the first welded body is taken out of the vacuum diffusion furnace; coating an indium film on a surface of one side of the first diamond welding transition piece of the first welding body; The second diamond welding transition piece and the second heat sink are placed in a vacuum diffusion furnace. Before welding, the vacuum welding furnace is evacuated to a vacuum degree of 1× ~4× Pa, pressurizing during welding, the pressure is set to 500 lb to 2000 lb, the time is 10 h to 30 h, and after the welding is completed, the second welded body is taken out of the vacuum diffusion furnace; coating an indium film on a surface of one side of the second diamond welding transition piece of the second welding body; The step of arranging the slab laser gain medium between a side of the first welding body close to the first diamond welding transition piece and a side of the second welding body close to the second diamond welding transition piece, and performing a welding process, comprises: Place the first welding body with the first diamond welding transition piece upward, the slab laser gain medium, and the second welding body with the second diamond welding transition piece downward in order from bottom to top; Place the current device in a vacuum soldering furnace and evacuate the vacuum soldering furnace to 1× before soldering. ~3× Pa, the welding temperature is 200 ℃ ~ 260 ℃, after keeping warm for 10 to 30 minutes, stop heating, cool to room temperature under vacuum state, take the current device out of the vacuum furnace, and the welding process of the device is completed; The opposing welding surfaces of the first heat sink, the second heat sink, the slab laser gain medium, the first diamond welding transition piece, and the second diamond welding transition piece are required to meet the following requirements: cleanliness ≤ 0.1 mg / c, flatness ≤ 0.5λ, λ = 632.8 nm, and smoothness ≤ 40 / 20; The thickness of the first diamond welding transition piece and the second diamond welding transition piece is 0.1 to 2 mm; and the welding length of the first diamond welding transition piece and the second diamond welding transition piece is the same as the welding length of the slab laser gain medium, and the welding width is 2 mm larger than the welding width of the slab laser gain medium; The optical film on the surface of the slab laser gain medium is a silicon dioxide film with a thickness of 2 to 5 μm; the titanium film has a thickness of 100 to 500 nm, and the gold film has a thickness of 300 to 800 nm; the dimensions of the slab laser gain medium are: length 10 to 300 mm, width 10 to 60 mm, and thickness 1 to 5 mm; The gold film thickness of the first heat sink and the second heat sink is 300-500 nm, and the indium film thickness is 10-200 μm; The titanium film thickness of the first diamond welding transition piece and the second diamond welding transition piece is 100-500 nm, the gold film thickness is 300-800 nm, and the indium film thickness is 10-200 μm.

2. The welding method of the slab laser gain medium module according to claim 1, characterized in that: The slab laser gain medium comprises: Slab laser crystal, doped Slab laser ceramics, Yb3+-doped slab laser crystals, Yb3+-doped slab laser ceramics.

Images