Process method for improving laser air-tight seal welding leakage rate and yield

Abstract

The invention discloses a technological method for improving the laser air-tight seal welding leakage rate and yield. The technological method comprises the following steps that S1, structure optimization design and material selection are conducted; s2, equipment parameter optimization setting; s3, laser focus position optimization; according to the scheme, the air seal welding leakage rate and the yield of aluminum alloy material combination (the cavity 6061 and the cover plate 4047) products can be greatly increased, the one-time sealing welding yield of the products is increased to 95% from 75%, product rework is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of precision airtight packaging, and in particular to a process method for improving the leakage rate and yield rate of laser airtight welding. Background Art

[0002] Aluminum alloys have a dominant position in the hermetic packaging of microwave devices (such as waveguides, resonant cavities, and radar TR components) due to their lightweight, high specific strength, excellent electrical conductivity, and cost-effectiveness. As 5G communications, satellite payloads, and phased array radars develop towards higher frequencies and miniaturization, the airtightness requirements of electromagnetically sensitive components within the devices have reached 10 -9 Pa·m 3 / s level (helium mass spectrometry detection standard). Traditional TIG welding and electron beam welding are prone to excessive thermal deformation or vacuum chamber limitations. Laser welding, with its high energy density, non-contact processing, and narrow heat-affected zone (HAZ), has become the preferred process for precision hermetic packaging.

[0003] Despite the theoretical advantages of laser welding, the physical properties of aluminum alloy (high reflectivity, volatilization of low-boiling-point elements) and metallurgical characteristics (interference from oxide films, solidification shrinkage) result in actual hermetic seal weld leak rate yields of less than 75% (industry research data). To improve the leak rate yield of product hermetic seals, reduce product rework, and increase production efficiency, a process method to improve the leak rate yield of laser hermetic seal welding is urgently needed to significantly increase the first-pass pass rate of microwave product hermetic seal welds. Summary of the Invention

[0004] In response to the above technical problems, the present invention provides a process method for improving the leakage rate and yield of laser hermetic sealing welding, so as to solve the problem of low yield of hermetic sealing welding of microwave products.

[0005] The present invention is achieved by adopting the following technical solutions: A process for improving the leak rate and yield rate of laser hermetic sealing welding comprises the following steps: Step S1: Optimize structural design and material selection; Step S2: Optimize device parameter settings; Step S3: Optimizing the laser focus position; Step S4: Optimizing the sealing process.

[0006] Furthermore, the optimization of the structural design and material selection in step S1 specifically includes: Step S11: The chamfer inside the cover plate cavity is designed to be an arc, the step of the embedded cover plate is set to 0.5 mm, the distance between the weld and the cavity edge is set to 0.5 mm, and the distance between the edge of the insulator hole and the laser welding area is set to 1.5 mm; Step S12: The cover plate thickness is set to 1 mm; Step S13: The fitting clearance between the cavity and the cover plate is set to 0.04 mm, and the height difference between the cover plate thickness and the cover plate cavity depth is set to ±0.05 mm; Step S14: The aluminum alloy material type of the cavity is selected as 6061, and the aluminum alloy material type of the cover plate is selected as 4047; Step S15: applying natural color conductive oxidation to the surface of the cavity and the cover plate.

[0007] Furthermore, the optimization of the equipment parameters in step S2 specifically includes: Step S21: The welding speed of the laser sealing machine is set to 5 mm / s, the light output frequency is set to 28 Hz, the maximum power is set to 3.2 KW ± 0.2 KW, and the pulse width is set to 2.7 ms.

[0008] Furthermore, the optimization of the laser focus position in step S3 specifically includes: Step S31: The defocus amount is set to negative defocus, and the value is set to -2.0 mm.

[0009] Furthermore, the optimization of the sealing procedure in step S4 includes a pre-sealing step and a sealing step performed in sequence, and the pre-sealing step specifically includes: Step S41: during programming, the focus center is shifted along the weld toward the cover plate so that the weld track is located at a distance ratio of about 2:3 between the cavity and the cover plate; Step S42: Edit the cavity and cover pre-fixation program, and make a dot every 20 mm; Step S43: using anhydrous ethanol to clean the cavity and the cover plate weld to remove dust, residual glue and burrs; Step S44: The cavity and the cover are trial-fitted, and the fitting clearance is less than 0.04 mm.

[0010] Furthermore, the sealing step specifically includes: Step S45: Fix the cavity and the cover plate by dotting; Step S46: using the optimized process parameters to set equipment parameters; Step S47: using a sealing welding procedure with an optimized trajectory to complete the sealing welding of the cavity and the cover plate.

[0011] The beneficial effects of the present invention are as follows: the present invention proposes a process method for improving the leak rate and yield rate of laser hermetic sealing welding of an aluminum alloy material combination (cavity 6061 + cover plate 4047), which can greatly improve the leak rate and yield rate of hermetic sealing welding of aluminum alloy material combination (cavity 6061 + cover plate 4047), and increase the one-time sealing yield rate of the product from 75% to 95%, thereby reducing product rework and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0013] Figure 1 Schematic diagram of a process flow for improving the leak rate and yield rate of laser hermetic sealing welding according to an embodiment of the present invention; Figure 2 Schematic diagram of parameter curve in an embodiment of the present invention. DETAILED DESCRIPTION

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0015] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0016] The following is combined with Figure 1-2 , some embodiments of the present invention are described in detail. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0017] The present invention proposes a process method for improving the leakage rate and yield of laser gas seal welding, such as Figure 1 As shown, the following steps are included: S1: Structural design optimization and material selection; S2: Optimization of equipment parameter settings; S3: Laser focus position optimization; S4: Sealing process optimization.

[0018] In a preferred embodiment, step S1 optimization includes the following sub-steps: S11: The chamfer inside the cover cavity is designed to be circular, and the step inside the cover is 0.5mm. The distance between the weld and the cavity edge is 0.5mm, and the distance between the edge of the insulator hole and the laser welding area is 1.5mm. S12: Cover thickness is 1mm; S13: The clearance between the cavity and the cover is 0.04mm, and the height difference between the cover thickness and the cover cavity depth is ±0.05mm; S14: The aluminum alloy material of the cavity is 6061, and the aluminum alloy material of the cover is 4047; S15: The cavity and cover surfaces are made of natural conductive oxide (Al / Ct•Ocd(SR)).

[0019] In a preferred embodiment, step S2 optimization includes the following sub-steps: S21: The laser sealing machine (Dazhan) has a welding speed of 5 mm / s, a light frequency of 28 Hz, a maximum power of 3.2 kW ± 0.2 kW, and a pulse width of 2.7 ms.

[0020] In a preferred embodiment, step S3 optimization includes the following sub-steps: S31: To ensure the weld penetration, set the defocus amount to negative defocus; In a preferred embodiment, step S4 optimization includes the following sub-steps: S41: To improve the weld yield and avoid microcracks, when programming, first align the laser focus center with the weld center, and then move the focus center 100~120 microns toward the cover plate (4047), so that the weld laser track is located at a distance ratio of about 2:3 between the cavity and the cover plate, increase the silicon-metal ratio of the weld, make the spoon pool metal have better fluidity, and reduce thermal cracks during welding.

[0021] S42: Edit the cavity and cover pre-fixing program, and make a dot every 20mm.

[0022] S43: Use anhydrous ethanol to clean the cavity and cover welds to remove dust, residual glue and burrs; S44: Test fit the cavity and cover plate, and the fit clearance is less than 0.04mm.

[0023] S45: Fix the cavity and the cover plate with dots; S46: Setting equipment parameters using optimized process parameters; S47: Use the sealing welding procedure with optimized trajectory to complete the sealing welding of the cavity and the cover.

[0024] For the sake of simplicity, the aforementioned embodiments are described as a series of actions. However, those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are preferred embodiments, and the actions involved are not necessarily required by this application.

[0025] The above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Without departing from the spirit and scope of the present invention, modifications and variations made by those skilled in the art without departing from the spirit and scope of the present invention should be within the scope of protection of the appended claims.

Claims

1. A process for improving the leakage rate and yield of laser hermetic sealing welding, characterized in that: The following steps are involved: Step S1: Optimize structural design and material selection; Step S2: Optimize device parameter settings; Step S3: Optimizing the laser focus position; Step S4: Optimizing the sealing process.

2. A process for improving the leakage rate and yield of laser hermetic sealing welding according to claim 1, characterized in that: The optimization of the structural design and material selection in step S1 specifically includes: Step S11: The chamfer inside the cover plate cavity is designed to be an arc, the step of the embedded cover plate is set to 0.5 mm, the distance between the weld and the cavity edge is set to 0.5 mm, and the distance between the edge of the insulator hole and the laser welding area is set to 1.5 mm; Step S12: The cover plate thickness is set to 1 mm; Step S13: The fitting clearance between the cavity and the cover plate is set to 0.04 mm, and the height difference between the cover plate thickness and the cover plate cavity depth is set to ±0.05 mm; Step S14: The aluminum alloy material type of the cavity is selected as 6061, and the aluminum alloy material type of the cover plate is selected as 4047; Step S15: applying natural color conductive oxidation to the surface of the cavity and the cover plate.

3. A process for improving the leakage rate and yield of laser hermetic sealing welding according to claim 1, characterized in that: The optimization of the equipment parameters in step S2 specifically includes: Step S21: The welding speed of the laser sealing machine is set to 5 mm / s, the light output frequency is set to 28 Hz, the maximum power is set to 3.2 KW ± 0.2 KW, and the pulse width is set to 2.7 ms.

4. A process for improving the leakage rate and yield of laser hermetic sealing welding according to claim 1, characterized in that: The optimization of the laser focus position in step S3 specifically includes: Step S31: The defocus amount is set to negative defocus, and the value is set to -2.0 mm.

5. A process for improving the leakage rate and yield of laser hermetic sealing welding according to claim 1, characterized in that: The optimization of the sealing process in step S4 includes a pre-sealing step and a sealing step performed in sequence, and the pre-sealing step specifically includes: Step S41: during programming, the focus center is shifted along the weld toward the cover plate so that the weld track is located at a distance ratio of about 2:3 between the cavity and the cover plate; Step S42: Edit the cavity and cover pre-fixation program, and make a dot every 20 mm; Step S43: using anhydrous ethanol to clean the cavity and the cover plate weld to remove dust, residual glue and burrs; Step S44: The cavity and the cover are trial-fitted, and the fitting clearance is less than 0.04 mm.

6. A process for improving the leakage rate and yield of laser hermetic sealing welding according to claim 1, characterized in that: The sealing step specifically includes: Step S45: Fix the cavity and the cover plate by dotting; Step S46: using the optimized process parameters to set equipment parameters; Step S47: using a sealing welding procedure with an optimized trajectory to complete the sealing welding of the cavity and the cover plate.

Images