Dynamic calibration method for precise stamping preparation of gold-based soldering lug based on multi-mode laser positioning

Abstract

The invention discloses a dynamic calibration method for precise stamping preparation of a gold-based soldering lug based on multi-mode laser positioning, and belongs to the technical field of high-precision brittle gold-based soldering lug manufacturing. Comprising the following steps that a strip roll material is fed into a machining table top, and a welding strip is positioned through positioning laser; visual data of the edge of the strip coil stock and the multi-stage combined stamping head are obtained, and the pre-stamping offset of the edge of the strip coil stock and a rough stamping head in the multi-stage combined stamping head is calculated; the pre-punching offset is transmitted to a displacement compensation table and a multi-stage combined punching head for displacement compensation; rough punching is conducted on the strip roll material through a rough punching head, and the gold-based soldering lug is fixed; collecting an edge image of the gold-based soldering lug after rough punching, and calculating an edge trimming amount; and the edge finishing amount is transmitted to a red laser finishing device in the multi-stage combined punching head for fine punching. Through multi-stage stamping and post-stamping laser trimming, visual identification and a trimming amount algorithm are combined, and the machining precision of + / -5 [mu] m level of the X-Y axial surface can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-precision brittle gold-based solder sheet manufacturing, and particularly relates to a dynamic calibration method for precision stamping preparation of gold-based solder sheet based on multi-modal laser positioning. BACKGROUND

[0002] With the improvement of the packaging density of optoelectronic devices and power devices, higher requirements are put forward for the size accuracy of the used packaging solder sheet. In the batch production process of high-precision brittle solder sheet and pre-formed solder sheet, problems such as stamping cracks, edge collapse, burrs, large cutting size deviation (> ± 0.1 mm), large thickness tolerance (> 0.05 mm), and frequent shutdown calibration and solder sheet oxidation caused by traditional stamping mode are faced.

[0003] The Chinese patents "CN111215684A Ultra-thin gold-tin solder cutting device" and "CN221414658U Gold-tin solder sheet punching die" break through the limitations of large manual positioning and high cumulative deviation of multi-hole stamping by innovatively designing horizontal and vertical stamping and cutting dies and replaceable stamping die cores, but the continuous stamping mode will cause 3% to 5% elongation rate fluctuation of the material. The traditional die cannot realize dynamic compensation before and after stamping, which increases the processing tolerance of the solder sheet.

[0004] Therefore, a dynamic calibration method for precision stamping preparation of gold-based solder sheet based on multi-modal laser positioning is needed to solve the problems of solder sheet cracks, large size tolerance, solder sheet edge burrs, and low preparation efficiency that easily occur during the preparation of brittle gold-based solder sheet. SUMMARY

[0005] The purpose of the present application is to provide a dynamic calibration method for precision stamping preparation of gold-based solder sheet based on multi-modal laser positioning, which comprises the following steps:

[0006] The strip material coil is sent to the processing table, and the positioning laser is used to position the solder strip;

[0007] The visual data of the edge of the strip material coil and the multi-stage combined stamping head are acquired, and the pre-stamping offset of the edge of the strip material coil and the rough stamping head in the multi-stage combined stamping head is calculated;

[0008] The pre-stamping offset is transmitted to the displacement compensation table and the multi-stage combined stamping head for displacement compensation;

[0009] The rough stamping head is used to rough stamp the strip material coil, and the gold-based solder sheet is fixed;

[0010] The edge image of the gold-based solder sheet after rough stamping is collected, and the edge trimming amount is calculated;

[0011] The edge trimming amount is transmitted to the red laser refiner in the multi-stage combined stamping head for fine stamping.

[0012] Further, the specific process of calculating the edge trimming amount is:

[0013] Initialize the system parameters of target width, target height and trimming threshold;

[0014] Pretreat and detect the edge image of the gold-based solder, and obtain the maximum contour;

[0015] Measure the actual size of the maximum contour, and calculate the average trimming amount;

[0016] Generate a laser trimming path, simplify the maximum contour, calculate the offset path, and obtain the center offset trimming amount.

[0017] Further, the material composition of the gold-based solder is Au80Sn20 alloy.

[0018] Further, the positioning laser is a picosecond green laser with a wavelength of 532nm and a power greater than 50W.

[0019] Further, the processing laser of the red laser fine trimmer is an infrared femtosecond laser with a wavelength of 1064nm, and the laser processing energy density is controlled at 0.5-3J / cm 3 , and the processing spot is 0.005-0.05mm.

[0020] Further, the compensation accuracy of the displacement compensation table on the X-Y axis plane is ±5μm.

[0021] Further, the pressure of the rough punching head for rough punching of the strip material coil is 80-200MPa.

[0022] Further, the time of fine punching is 0.3-1.5s.

[0023] The beneficial effects of the present application are:

[0024] The present application provides a dynamic calibration method for precision stamping preparation of gold-based solder based on multi-modal laser positioning, which is suitable for preparation of high-precision micrometer-level brittle gold-based solder. Through the processing mode of multi-stage stamping and laser trimming after stamping, combined with visual recognition and trimming amount algorithm, the processing accuracy of X-Y axis plane ±5μm is realized, and the preparation of low processing tolerance, high precision, flat edge without collapse, and surface without oxidation of brittle gold-based solder can be realized, especially the preparation of special-shaped, large brittle and ultra-thin solder. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The flow chart of the dynamic calibration method for precision stamping preparation of gold-based solder based on multi-modal laser positioning;

[0026] Figure 2A device diagram for precision stamping of gold-based soldering pieces based on multi-modal laser positioning;

[0027] Figure 3 (a) and (b) are respectively the edge profile comparison diagram of the soldering piece processed by the traditional method and the method of the present application. DETAILED DESCRIPTION

[0028] The present application proposes a dynamic calibration method for precision stamping of gold-based soldering pieces based on multi-modal laser positioning. The present application will be further described below in conjunction with the drawings and specific embodiments.

[0029] Figure 1 A flowchart of the dynamic calibration method for precision stamping of gold-based soldering pieces based on multi-modal laser positioning, specifically:

[0030] 1. The strip material coil is fed into the processing table, and the positioning laser is used to position the solder strip.

[0031] Figure 2 A device diagram for precision stamping of gold-based soldering pieces based on multi-modal laser positioning, a multi-stage combined stamping head 1, including a rough stamping head and a red laser finishing device; an image positioning all-in-one machine 2 is a laser positioner and a high-resolution COMS camera, a green laser with a wavelength of 532 nm and a power of 300 W green light positioning laser (accuracy ±2 μm) is used for real-time distance measurement, a high-resolution camera is used to identify the size and edge features of the strip material to be processed, and both are coordinated to realize visual identification, and the module is built-in CNN-based pre-stamping offset measurement and edge trimming algorithm; a displacement compensation table 3 is used to execute the offset and trimming amount after visual identification; a visual calibration area 4 is a camera monitoring coverage area for visual identification, and below it is a vacuum suction platform made of multi-hole ceramic material.

[0032] When the strip material coil enters the processing table, the platform immediately performs vacuum suction, and the camera of the multi-modal laser positioning module is triggered to start sampling at a frequency of 100 Hz, and a positioning request is sent synchronously. The green laser positioner is started, and feedback is given to the visual identification camera and a positioning scanning network (interval 50 μm) is generated according to the collected pictures, covering the visual calibration area 4 in Figure 2 , with a coverage range of about 300*300 mm 2 .

[0033] 2. Obtain the visual data of the edge of the strip material coil and the multi-stage combined stamping head, and calculate the pre-stamping offset of the edge of the strip material coil and the rough stamping head in the multi-stage combined stamping head. After the pre-stamping offset algorithm obtains the visual data, the offset ΔX=+a μm, ΔY=+b μm (a, b≥50 μm) between the edge of the strip material and the rough stamping head is fed back.

[0034] The pre-stamping offset measurement Python code is as follows:

[0035]

[0036] 3、The offset amount is transmitted to the displacement compensation platform and the multi-stage combined stamping head for displacement compensation.

[0037] 4、The rough stamping head is used to rough stamp the strip material coil to fix the gold-based solder sheet. After displacement compensation, the rough stamping head implements rough stamping processing at a pressure of 80-200 MPa and a speed of 0.2 s / piece. After the processing is completed, the vacuum adsorption force of the multi-hole ceramic below the processing platform is increased, further fixing the solder sheet after processing independent of the strip material.

[0038] 5、The edge image of the gold-based solder sheet after rough stamping is collected, and the edge trimming amount is calculated. After rough stamping, the specific process of calculating the edge trimming amount is as follows: initialize the system parameters of the target width, target height, and trimming threshold; pre-process and detect the edge image of the gold-based solder sheet to obtain the maximum contour; measure the actual size of the maximum contour to calculate the average trimming amount; generate a laser trimming path, simplify the maximum contour, calculate the offset path, and obtain the center offset trimming amount.

[0039] The following code is implemented:

[0040]

[0041]

[0042]

[0043] 6、The edge trimming amount is transmitted to the red laser trimmer in the multi-stage combined stamping head for fine stamping.

[0044] The visual recognition component is started again, entering the fine stamping stage. The camera collects the edge image of the solder sheet after rough stamping at a frequency of 500 Hz. The trimming amount required for solder sheet edge trimming is calculated by the edge trimming amount calculation code, ΔX = ±a μm, ΔY = ±b μm (50 μm ≥ a, b ≥ 5 μm), x = c °, y = d ° (0 ° ≥ c, d ≥ 90 °), and the trimming amount data is fed back to the red laser trimmer (wavelength 1064 nm, processing power 300 W, processing spot 0.005-0.05 mm). The red laser trimmer completes the fine trimming process within 0.3-1.5 s.

[0045] The following Au80Sn20 alloy (Sn content 20±0.5wt%) is selected as the material of the solder sheet. After vacuum induction melting, pouring, rough rolling, and fine rolling, the alloy strip with a thickness of 0.05 mm and a width of 90 mm is processed.

[0046] Using a traditional cold stamping system, a 6*4mm rectangular stamping die was selected. The stamping pressure was set to 10 tons, and the stamping speed was 0.4s / cycle. The stamping was transverse, with individual weld pieces spaced 4mm apart along the length and 6mm apart along the width. A 5mm allowance was left on each side of the width edge, and a 20mm allowance was left at the front and back along the length to transmit micro-tension in the tension system. The process involved simultaneous stamping and winding. Approximately 768 weld pieces (6*4*0.05mm in size) were stamped from a 1000mm long strip, taking a total of 308 seconds.

[0047] The strip is placed using a micro-tension system Figure 2 In the visual calibration area 4, a multi-stage combined stamping head is installed, and the porous adsorption platform below is activated at a speed of 1×10 3 The pressure of Pa is used to adsorb and fix the welding material to be processed. The laser positioner and camera are activated simultaneously to scan and position the welding strip on the vision platform at a sampling frequency of 100Hz. The data is fed back to the built-in computer system, which calculates the arrangement of the 6*4mm welding strips within the coverage area of ​​the vision platform through the pre-punch offset: it can be arranged longitudinally for punching and cutting, punching along the length of the welding strip with a longitudinal spacing of 3mm. The welding strip is only driven by micro-tension, and the longitudinal direction is fixed to the micro-tension drive shafts on both sides by the drive belt, with a total reserved length of about 10mm. The punching spacing in the width direction is 1mm. The pre-punch offset calculation shows that the welding strip needs to be offset by 0.1mm on the Y-axis to ensure the accuracy of the set rough punching arrangement scheme, and feeds back to the displacement platform below for execution. After displacement compensation, the rough punch performs the rough punching process with a pressure of 200MPa and a speed of 0.2s / piece.

[0048] Entering the fine blanking stage, the multi-stage punch moves to the next weld sheet for stamping. Simultaneously, the vision module is reactivated and performs edge measurement of the weld sheet after rough blanking at a frequency of 500Hz. The required trimming amount ΔX = -20μm and ΔY = +30μm is calculated using edge trimming calculation code. A 1064nm red laser with a processing power of 300W and a processing spot size of 0.01mm completes the trimming in 0.3s. After processing in the vision platform area, vacuum adsorption and degassing are performed, and the weld strip moves to the unprocessed area, repeating the above process. A total of 1870 weld sheets were processed. Due to the partial overlap between the multi-stage stamping and laser fine trimming processes, the total processing time was 657s, with an average time of 0.35s per sheet. Compared to the control group, the processing efficiency is improved by approximately 12%. Adding multiple multi-stage combined stamping heads could significantly increase the processing efficiency.

[0049] Figure 3 (a) and (b) are comparative images of the edge morphology of the weld sheets processed by the conventional method and the method of the present invention, respectively. The results of observing the edges of the stamped weld sheets using an optical microscope show that the conventional method results in serrated edges and collapsed edges. The method of the present invention produces straight edges, with a significantly higher quality than the comparative example.

[0050] The present application can realize the processing precision of X-Y axis face ±5μm level by the processing mode of multi-stage stamping and post-stamping laser trimming, combines with visual identification and trimming calculation algorithm, realizes the preparation of brittle gold-based soldering sheet with low processing tolerance, high precision, flat edge without collapse, and surface without oxidation, especially the preparation of special-shaped, large brittle and ultra-thin soldering sheet.

Claims

1. A dynamic calibration method for precision stamping fabrication of gold-based solder sheets based on multimodal laser positioning, characterized in that, Includes the following steps: The strip coil is fed into the processing table, and the welding strip is positioned using a positioning laser; Obtain visual data of the strip coil edge and the multi-stage combined stamping head, and calculate the forward offset of the strip coil edge and the coarse stamping head in the multi-stage combined stamping head. The forward offset is transmitted to the displacement compensation table and the multi-stage combined stamping head for displacement compensation. The strip coil is rough punched using a rough punching head to fix the gold-based welding sheet; Acquire edge images of the gold-based solder sheet after rough punching and calculate the edge trimming amount; The edge trimming amount is transmitted to the red laser finishing device in the multi-stage combined stamping head for fine stamping.

2. The dynamic calibration method for precision stamping preparation of gold-based solder sheets based on multimodal laser positioning according to claim 1, characterized in that, The specific process for calculating the edge trimming amount is as follows: Initialize the system parameters for target width, target height, and trimming threshold; The edge image of the gold-based solder sheet is preprocessed and detected to obtain the maximum contour. Measure the actual dimensions of the maximum profile and calculate the average trimming amount; Generate a laser trimming path, simplify the maximum contour, calculate the offset path, and obtain the trimming amount offset towards the center.

3. The dynamic calibration method for precision stamping preparation of gold-based solder sheets based on multimodal laser positioning according to claim 1 or 2, characterized in that, The material composition of the gold-based solder sheet is Au80Sn20 alloy.

4. The dynamic calibration method for precision stamping preparation of gold-based solder sheets based on multimodal laser positioning according to claim 3, characterized in that, The positioning laser is a picosecond-level green laser with a wavelength of 532nm and a power greater than 50W.

5. The dynamic calibration method for precision stamping preparation of gold-based solder sheets based on multimodal laser positioning according to claim 3, characterized in that, The processing laser of the red laser finishing device is an infrared femtosecond laser with a wavelength of 1064 nm, and the laser processing energy density is controlled between 0.5 and 3 J / cm². 3 The processing spot size is 0.005 to 0.05 mm.

6. The dynamic calibration method for precision stamping preparation of gold-based solder sheets based on multimodal laser positioning according to claim 3, characterized in that, The compensation accuracy of the displacement compensation stage on the XY axis is ±5μm.

7. The dynamic calibration method for precision stamping preparation of gold-based solder sheets based on multimodal laser positioning according to claim 1, characterized in that, The pressure used for rough punching of strip coils with a rough punching head is 80-200 MPa.

8. The dynamic calibration method for precision stamping preparation of gold-based solder sheets based on multimodal laser positioning according to claim 1, characterized in that, The fine-stamping time is 0.3 to 1.5 seconds.

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