Metal mask plate repairing method and metal mask plate

Abstract

The invention discloses a metal mask plate repairing method and a metal mask plate, a plurality of etching holes are formed in the metal mask plate, and the metal mask plate repairing method comprises the following steps: detecting the size and the edge shape of each etching hole in the metal mask plate, determining the defect part of the etching hole, and performing repair on the defect part of the etching hole; the defects comprise size out-of-tolerance and edge damage of the etching hole; arranging a welding material at the defect part; fusing a welding material and the metal mask plate by using pulse laser to form a welding spot so as to fill the defect part; and the height of the portion, protruding out of the metal mask plate, of the welding spot is obtained, the welding spot is ground according to the height, and the repaired metal mask plate is obtained. According to the invention, the over-etching problem of the metal mask plate is solved, and the yield is improved.

Description

Technical Field

[0001] This invention relates to the field of metal mask manufacturing technology, specifically to a metal mask repair method and a metal mask. Background Technology

[0002] With increasingly stringent yield requirements for high-precision metal masks, it is necessary to address the frequent over-etching issue that occurs during the production process. Currently, high-precision metal mask (FMM, Fine Metal Mask) products are NG (No Good) if over-etching is detected after etching and cleaning, resulting in an over-etching rate of 60% to 70%, which severely impacts FMM yield. Therefore, a method is needed to repair over-etched FMMs into qualified FMMs. Summary of the Invention

[0003] This invention aims to address one of the technical problems in related technologies to a certain extent. Therefore, this invention provides a method for repairing a metal mask and a metal mask itself.

[0004] To achieve the above objectives, a first aspect of the present invention provides a method for repairing a metal mask plate, wherein the metal mask plate has a plurality of etched holes, comprising the following steps: The size and edge shape of each etched hole on the metal mask are inspected to determine the defect location of the etched hole, the defect including dimensional deviation and edge damage of the etched hole; Welding material is applied to the defective area; A pulsed laser is used to fuse the welding material with the metal mask to form a weld point, thereby filling the defective area; The height of the solder joint protruding from the metal mask is obtained, and the solder joint is ground flat according to the height to obtain the repaired metal mask.

[0005] Optionally, the step of using a pulsed laser to fuse the welding material with the metal mask to form a weld joint includes: The heating temperature of the pulsed laser is controlled so that the welding material passes through the preheating section, the heat preservation section and the peak section in sequence. The temperature of the preheating section, the heat preservation section and the peak section increase in sequence. The temperature of the heat preservation section is maintained for a preset time so that the welding material fuses with the metal mask to form a weld point. Optionally, in the step of sequentially passing the welding material through the preheating section, the heat preservation section, and the peak heating section: The temperature of the preheating section is 120~250℃, the laser power is 30~80W, and the pulse width is 5~10ms; The temperature of the heat preservation section is 250~270℃, the laser power is 80~150W, the pulse width is 2~5ms, and the duration of the heat preservation section is 25~35s; The peak temperature range is 320~330℃, the laser power is 30~60W, and the pulse width is 3~8ms. The range of single-pulse energy in the preheating section, peak section, and heat preservation section is 0.1~0.8J.

[0006] The range of single-pulse energy in the preheating section, peak section, and heat preservation section is 0.1~0.8J.

[0007] Optionally, in the step of using a pulsed laser to fuse the welding material with the metal mask to form a weld point, the minimum spot diameter of the pulsed laser is controlled at 0.2 mm, corresponding to a weld point diameter of 0.1~0.3 mm and a welding depth of 0.1~0.3 mm; the weld point diameter is 0.01~0.02 mm larger than the defect width, and the maximum weld point diameter does not exceed 0.3 mm.

[0008] Optionally, the side offset of the weld point is less than 1 / 3 of the defect width; the height of the weld point extends to 1 / 4 of the height of the interface between the welding material and the metal mask, and does not exceed 0.05mm above the surface of the metal mask; the welding width at the end of the weld point is at least 2 / 3 of the defect width.

[0009] Optionally, welding material is applied to the defective area, including: Welding material is applied to the defective area using a squeegee printing method. The printing thickness is matched to the depth of the defective area. The printing pressure is controlled at 0.1~0.3MPa, and the squeegee moving speed is 20~50mm / s.

[0010] Optionally, the soldering materials include lead-free solder paste and flux.

[0011] Optionally, the step of detecting the size and edge shape of each etched hole on the metal mask to determine the defect location of the etched hole includes: Position the metal mask on the support platform of the automated optical inspection equipment; The automated optical inspection equipment is controlled to identify the size and edge shape of each etched hole and determine the defect location of the etched hole.

[0012] Optionally, obtaining the height by which the solder joint protrudes from the metal mask, and grinding the solder joint flat according to the height, includes: The height of the solder joint protruding from the metal mask plate was measured using a white light interferometer. When the height was greater than 5... At that time, the protruding parts are ground flat so that the solder joints are flush with the metal mask plate.

[0013] A second aspect of the present invention provides a metal mask plate, comprising a metal mask plate prepared by the metal mask plate repair method described in the first aspect of the present invention.

[0014] This invention addresses two high-frequency defects in FMMs (Film Milling Machines): dimensional deviations in etched holes and edge damage (i.e., over-etching, where the etching process exceeds the preset process standard range, resulting in the actual size of the etched hole being larger than the design size; essentially, excessive material removal during etching). By precisely detecting the size and edge shape of each etched hole, no defective areas are missed. Subsequent pulsed laser fusion and targeted grinding processes achieve precise filling and surface smoothing of the defective areas, avoiding secondary damage to surrounding qualified etched holes during the repair process and meeting the micron-level precision requirements of high-precision FMMs. Furthermore, each step is easily integrated with existing FMM production lines' AOI (Automated Optical Inspection) equipment, laser processing equipment, and precision testing equipment, eliminating the need for large-scale modifications to existing production systems and enabling rapid industrial-scale batch repair. Pulsed laser fusion achieves metallurgical bonding between the welding material and the FMM substrate, resulting in high weld strength and preventing detachment or failure during subsequent use. Simultaneously, by measuring the weld protrusion height and grinding it down, the surface flatness of the repaired FMM is ensured to be consistent with the original product, without affecting the precision of subsequent application processes such as vapor deposition. This guarantees that the performance of the repaired product is on par with that of the original qualified FMM.

[0015] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and accompanying drawings. The preferred embodiments or means of the present invention will be shown in detail in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of the present invention. In addition, each of these features, elements and components appearing in the following text and drawings is a plurality of, and different symbols or numbers are used for convenience of representation, but all represent parts with the same or similar construction or function. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a flowchart of the present invention.

[0017] Figure 2(a) is a pseudo-color image of the three-dimensional height of the solder joint in this invention.

[0018] Figure 2(b) is a two-dimensional micrograph of the solder joint in this invention.

[0019] Figure 2(c) is a quantitative analysis curve of the solder joint height in this invention.

[0020] Figure 3 This is a schematic diagram of the defect location of the metal mask plate in this invention.

[0021] Figure 4 This is a schematic diagram of a welding method for filling defects in this invention.

[0022] Figure 5 This is a schematic diagram of another welding method for filling defects in this invention.

[0023] Figure 6 This is the metal mask plate used in this invention to complete the repair after grinding the solder joints. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described are intended to explain the present invention and should not be construed as limiting the invention.

[0025] The terms "an embodiment," "example," or "trademark" used in this specification refer to a particular feature, structure, or characteristic described in connection with the embodiment itself that may be included in at least one embodiment disclosed in this patent. The phrase "in an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0026] Example 1 like Figure 1 As shown, this embodiment provides a method for repairing a metal mask plate, wherein the metal mask plate has multiple etched holes, including the following steps: S100. Inspect the size and edge shape of each etched hole on the metal mask to determine the defect location of the etched hole, the defect including dimensional deviation and edge damage; specifically, such as... Figure 3 As shown, out-of-tolerance etching hole size refers to the etching process exceeding the preset process standard range, resulting in the actual size of the etched hole being larger than the design size. Essentially, this is due to excessive material removal during etching. The other two types of high-frequency defects in FMM are edge breakage.

[0027] S110. Welding material is applied to the defective area; S120. Using a pulsed laser, the welding material is fused with the metal mask to form a weld point, thereby filling the defective area; S130. Obtain the height of the solder joint protruding from the metal mask plate, and grind the solder joint flat according to the height to obtain the repaired metal mask plate.

[0028] This embodiment employs a precision welding method using pulsed laser welding, which accurately controls heat output and weld size, and is suitable for micron-level over-etching defects. Before welding, the over-etched areas are degreased and deoxidized, and after welding, flux residue is removed by ultrasonic cleaning to avoid affecting the surface cleanliness of the FMM.

[0029] In some embodiments, the step of using a pulsed laser to fuse the welding material with the metal mask to form a weld joint includes: The heating temperature of the pulsed laser is controlled so that the welding material passes through the preheating section, the peak section and the holding section in sequence. The temperature of the preheating section, the holding section and the peak section increase in sequence. The temperature of the holding section is maintained for a preset time so that the welding material fuses with the metal mask to form a weld point. In some embodiments, in the step of sequentially passing the welding material through the preheating section, the heat preservation section, and the peak heating section: The temperature of the preheating section is 140℃, the laser power is 80W, and the pulse width is 10ms; The temperature of the heat preservation section is 262℃, the laser power is 150W, and the pulse width is 5ms; the duration of the heat preservation section is 25s. The peak temperature range is 320℃, the laser power is 30W, and the pulse width is 8ms. The range of single-pulse energy in the preheating section, peak section, and heat preservation section is 0.8J.

[0030] Specifically, the heating rate before 140℃ should be 1.2~1.8℃ / s. Too low a rate will cause the flux in the lead-free solder paste to evaporate prematurely, resulting in cold solder joints. Too high a rate will easily cause uneven heating of the solder paste in certain areas, generating micro-bubbles. This rate can steadily remove volatile components from the solder paste. The heating rate between 140~262℃ should be 2.4~3.0℃ / s. This range of rates can promote the full activation of the flux, remove the oxide layer on the surface of the FMM substrate, and at the same time avoid flux failure due to slow heating, laying a good foundation for subsequent soldering. Hold at 262℃ for 25~35s. If the time is insufficient, the solder paste will not melt sufficiently, and the solder joints will easily segregate and have poor bonding. If it exceeds 35s, it will consume too much flux and may also cause slight thermal deformation of the Invar substrate of the FMM. This length can balance the melting effect and the risk of thermal damage. After the heat preservation stage, the temperature rises to the peak stage, at 320℃, ensuring complete remelting of the lead-free solder paste, resulting in dense solder joints that are less prone to cracking at high temperatures. Temperatures above 330℃ can damage the edge structure of the FMM openings and may lead to coarse solder joint grains, affecting mechanical strength. This temperature ensures the solder joints are intact and do not damage the substrate. Therefore, cooling is required above 330℃. The initial cooling rate is 8~10℃ / s. Too slow a cooling rate will result in excessively large solder joint grains, reducing high-temperature stability; too fast a cooling rate can easily cause microcracks due to thermal stress. This rate allows the solder joints to solidify quickly while reducing the accumulation of thermal stress.

[0031] Furthermore, because FMMs are ultra-thin precision components, over-etching defects are mostly at the micrometer level, requiring the use of low-power layered pulsed lasers. The recommended laser power for the preheating stage is 30-80W with a pulse width of 5-10ms, to reduce the temperature gradient; the welding laser power for the holding stage is 80-150W with a pulse width of 2-5ms, precisely melting the lead-free solder and bonding it with Invar36; the thermal laser power for the peak stage and the subsequent cooling stage is 30-60W with a pulse width of 3-8ms, reducing the cooling rate and stress. Overall, the single-pulse energy needs to be controlled between 0.1-0.8J to avoid heat accumulation leading to thermal expansion of the substrate.

[0032] In some embodiments, in the step of using a pulsed laser to fuse the welding material with the metal mask to form a weld point, the minimum spot diameter of the pulsed laser is controlled at 0.2 mm, corresponding to a weld point diameter of 0.1 mm and a welding depth of 0.1 mm; the weld point diameter is 0.01~0.02 mm larger than the defect width, and the maximum weld point diameter does not exceed 0.3 mm.

[0033] In some embodiments, the lateral offset of the weld joint is less than 1 / 3 of the defect width; the height of the weld joint extends to 1 / 4 of the height of the interface between the welding material and the metal mask, and does not exceed 0.05 mm above the surface of the metal mask; the weld width at the end of the weld joint is at least 2 / 3 of the defect width. Specifically, the weld joint size must strictly match the micron-level slit of the FMM (minimum only 0.028±0.003 mm) to avoid clogging surrounding openings, while ensuring good fit with over-etched defects. Basic size standard: When using pulsed laser welding, the minimum spot diameter can be controlled at 0.2 mm, corresponding to a weld joint diameter of 0.1~0.3 mm and a welding depth of 0.1~0.3 mm. For micro-over-etched defects, the weld joint diameter needs to be 0.01~0.02 mm larger than the defect width to ensure complete coverage of the defect, and the maximum should not exceed 0.3 mm to prevent it from exceeding the defect range and affecting the surrounding structure.

[0034] Precision compatibility requirements: Referring to precision electronic component soldering specifications, the side offset of the solder joint must be less than 1 / 3 of the defect width to avoid offset into the normal opening area; the solder joint height must extend to 1 / 4 of the height of the lead-free solder joint interface with the substrate, forming a crescent shape, and must not exceed 0.05mm above the FMM surface to prevent obstruction of the vapor deposition path during vapor deposition. Furthermore, the solder joint must be free of bridging, solder balls, and other issues, and the end solder width must be at least 2 / 3 of the defect width to ensure a strong connection.

[0035] In some embodiments, the soldering materials include lead-free solder paste and flux, wherein the flux is a conventional flux used for metal soldering in the prior art. Since the substrate used in the FMM is Invar 36, its coefficient of thermal expansion is close to zero below 200°C, while the melting point of Sn42Bi58 low-temperature lead-free solder is only about 138°C, far lower than the Curie point (approximately 230°C) and melting temperature (1430°C) of Invar 36. This low-temperature soldering characteristic reduces thermal shock during repairs, preventing irreversible dimensional deformation of the FMM due to heat and ensuring the accuracy of subsequent vapor deposition. Sn-Bi-Ag modified lead-free solder can be used, with the addition of silver to improve solder joint toughness and reduce the risk of brittleness; alternatively, lead-free solder paste can be selected, whose solder joints maintain stable performance above 150°C, adapting to the vapor deposition working environment of the FMM.

[0036] Lead-free solder paste requires no additional pressure during soldering, but slight pressure is needed for positioning during bonding. A bonding pressure below 0.02 MPa will result in insufficient contact between the solder paste and the substrate, leading to cold solder joints; a pressure above 0.08 MPa will directly bend the FMM ultra-thin substrate, causing opening deformation. This pressure strikes a balance between bonding effectiveness and substrate protection. For small areas of FMM solder joint repair, too low an energy level will not trigger rapid melting of the solder paste; too high an energy level will create an excessively large heat-affected zone (exceeding 20°C). This process disrupts surrounding openings. Low-energy pulses can be precisely applied to solder joints, and through multiple stacking methods, micron-level solder joint formation can be achieved.

[0037] In some embodiments, welding material is applied to the defective site, including: The soldering material is applied to the defective areas using a squeegee printing method. The printing thickness matches the depth of the defect, the printing pressure is controlled at 0.3 MPa, and the squeegee movement speed is 20 mm / s. Specifically, the lead-free solder paste has a metal content of 91%. This content ensures the paste's viscosity and formability; a lower content will result in insufficient solder joint filling, while a higher content may cause the solder paste to clump together during printing, clogging the fine openings in the FMM (Front-Modifier Microscope). The powder specification is 25~38. The No. 4 low-oxide spherical powder has an effective service life of 8 hours. Within this time, the viscosity and activity of the solder paste remain stable, allowing for continuous batch repairs of electronic assemblies. If the service life is exceeded, the solder paste is prone to drying out, resulting in printing breaks and uneven solder joint sizes.

[0038] In some embodiments, detecting the size and edge shape of each etched hole on the metal mask to determine the defect location of the etched hole includes: Position the metal mask on the support platform of the automated optical inspection equipment; The automated optical inspection equipment is controlled to identify the size and edge shape of each etched hole and determine the defect location of the etched hole.

[0039] In some embodiments, obtaining the height by which the solder joint protrudes from the metal mask and grinding the solder joint flat according to the height includes: like Figure 4 and Figure 5 The diagrams illustrate two typical repair methods for solder joints. Figures 2(a), 2(b), and 2(c) show a multi-dimensional analysis of solder joint height detection. Figure 2(a) is a three-dimensional pseudo-color height image obtained through laser confocal scanning or white light interferometry, where color represents height. Figure 2(c) is a quantitative analysis curve of solder joint height, with the horizontal axis representing the scanning position and the vertical axis representing the height value. Sharp peaks represent the highest point of the solder joint, and a flat red baseline represents the surface height of the FMM substrate. This curve can accurately read the maximum height of the solder joint, the height difference (the height difference between the solder joint and the substrate), and the solder joint width, serving as the core quantitative basis for determining whether the solder joint meets process requirements. The height of the solder joint protruding from the metal mask is detected using a white light interferometer. When the height is greater than 5... During this process, the raised areas are ground flat to make the solder joint flush with the metal mask. Figure 2(b) is a two-dimensional micrograph, where the red curve represents the cross-sectional height profile taken along the red horizontal line in the image. The peak value of the curve corresponds to the highest point of the solder joint, and the valley value corresponds to the reference height of the substrate. The width of the curve reflects the lateral diffusion range of the solder joint.

[0040] Specifically, after welding and filling, the weld point is processed again using femtosecond laser grinding to correct dimensional deviations and ensure that the repaired defect area is consistent with the flatness and opening accuracy of the original FMM structure. Finally, the accuracy test confirms that it meets the evaporation coating standards.

[0041] First, the height and size data of the weld point are obtained through the height measurement module. Then, the parameters are adjusted in stages: most of the protrusions are quickly removed in the rough grinding stage, the parameters are finely adjusted in the fine grinding stage to ensure accuracy, and finally, the repaired defect area is inspected by a white light interferometer to ensure that the flatness and opening accuracy of the repaired defect area are consistent with the original structure of the FMM.

[0042] Laser core parameters: A femtosecond laser source is selected, with single-pulse energy controlled between 0.01 and 0.1 J, and pulse width in the femtosecond range, which can reduce the heat-affected zone (which needs to be controlled within 20). To avoid damaging surrounding openings, the following steps are taken: During grinding, a scanning process is used with a scanning speed of 5~20mm / s. Excess solder joints are removed by multiple low-energy stackings to prevent the substrate from being pitted due to excessive energy in a single pass.

[0043] Processing accuracy parameters: Laser spot diameter can be focused up to 1. The following matches an FMM less than 1. The opening machining accuracy is high; for weld point correction, the amount removed during each grinding is controlled within 0.1~1 mm. As the target size is gradually approached, the accuracy of the taper angle machining (referring to the angle formed between the sidewall of the etched hole and the vertical plane of the mask thickness direction) needs to be controlled within ±1° to ensure that the opening edge angle is consistent with the original structure.

[0044] Supporting control parameters: Combined with the positioning of the 3D machining head, the weld point position is calibrated by an image alignment system before grinding, with an alignment accuracy error of less than 1. With the online height measurement system providing real-time feedback on the grinding height, when the flatness error between the solder joint and the substrate is less than 1... Stop grinding immediately to avoid over-processing. For example... Figure 6 The image shows the FMM after welding and filling, which was then processed by femtosecond laser grinding. The repaired defect area has the same flatness and opening accuracy as the original FMM structure, confirming that it meets the evaporation deposition standards.

[0045] Example 2 This embodiment discloses a method for repairing a metal mask plate, wherein the metal mask plate has multiple etched holes, and includes the following steps: S100. Inspect the size and edge shape of each etched hole on the metal mask to determine the defect location of the etched hole, the defect including dimensional deviation and edge damage of the etched hole; S110. Welding material is applied to the defective area; S120. Using a pulsed laser, the welding material is fused with the metal mask to form a weld point, thereby filling the defective area; S130. Obtain the height of the solder joint protruding from the metal mask plate, and grind the solder joint flat according to the height to obtain the repaired metal mask plate.

[0046] In some embodiments, the step of using a pulsed laser to fuse the welding material with the metal mask to form a weld joint includes: The heating temperature of the pulsed laser is controlled so that the welding material passes through the preheating section, the peak section and the holding section in sequence. The temperature of the preheating section, the holding section and the peak section increase in sequence. The temperature of the holding section is maintained for a preset time so that the welding material fuses with the metal mask to form a weld point. In some embodiments, in the step of sequentially passing the welding material through the preheating section, the heat preservation section, and the peak heating section: The temperature of the preheating section is 140℃, the laser power is 80W, and the pulse width is 10ms; The temperature of the heat preservation section is 269℃, the laser power is 150W, and the pulse width is 5ms; the duration of the heat preservation section is 30s. The peak temperature is 330℃, the laser power is 60W, and the pulse width is 8ms. The range of single-pulse energy in the preheating section, heat preservation section and peak section is 0.1J.

[0047] In some embodiments, in the step of using a pulsed laser to fuse the welding material with the metal mask to form a weld point, the minimum spot diameter of the pulsed laser is controlled at 0.2 mm, corresponding to a weld point diameter of 0.3 mm and a welding depth of 0.1 mm; the weld point diameter is 0.02 mm larger than the defect width, and the maximum weld point diameter does not exceed 0.3 mm.

[0048] In some embodiments, the side offset of the solder joint is less than 1 / 3 of the defect width; the height of the solder joint extends to 1 / 4 of the height of the interface between the welding material and the metal mask, and does not exceed 0.05 mm above the surface of the metal mask; the welding width at the end of the solder joint is at least 2 / 3 of the defect width.

[0049] In some embodiments, welding material is applied to the defective site, including: Welding material is applied to the defective area using a squeegee printing method. The printing thickness is matched to the depth of the defective area. The printing pressure is controlled at 0.3 MPa, and the squeegee moving speed is 50 mm / s.

[0050] In some embodiments, the soldering materials include lead-free solder paste and flux.

[0051] In some embodiments, detecting the size and edge shape of each etched hole on the metal mask to determine the defect location of the etched hole includes: Position the metal mask on the support platform of the automated optical inspection equipment; The automated optical inspection equipment is controlled to identify the size and edge shape of each etched hole and determine the defect location of the etched hole.

[0052] In some embodiments, obtaining the height by which the solder joint protrudes from the metal mask and grinding the solder joint flat according to the height includes: The height of the solder joint protruding from the metal mask plate was measured using a white light interferometer. When the height was greater than 5... At that time, the protruding parts are ground flat so that the solder joints are flush with the metal mask plate.

[0053] A second aspect of the present invention provides a metal mask plate, comprising a metal mask plate prepared by the metal mask plate repair method described in the first aspect of the present invention.

[0054] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A method for repairing a metal mask, wherein a plurality of etched holes are formed on the metal mask, characterized in that, Includes the following steps: The size and edge shape of each etched hole on the metal mask are inspected to determine the defect location of the etched hole, the defect including dimensional deviation and edge damage of the etched hole; Welding material is applied to the defective area; A pulsed laser is used to fuse the welding material with the metal mask to form a weld point, thereby filling the defective area; The height of the solder joint protruding from the metal mask is obtained, and the solder joint is ground flat according to the height to obtain the repaired metal mask.

2. The metal mask plate repair method according to claim 1, characterized in that, The method of using pulsed laser to fuse welding materials with the metal mask to form weld joints includes: The heating temperature of the pulsed laser is controlled so that the welding material passes through the preheating section, the heat preservation section and the peak section in sequence. The temperature of the preheating section, the heat preservation section and the peak section increase in sequence. The temperature of the heat preservation section is maintained for a preset time so that the welding material fuses with the metal mask to form a weld point.

3. The metal mask plate repair method according to claim 2, characterized in that, In the step of sequentially passing the welding material through the preheating section, the heat preservation section, and the peak heating section: The temperature of the preheating section is 120~250℃, the laser power is 30~80W, and the pulse width is 5~10ms; The temperature of the heat preservation section is 250~270℃, the laser power is 80~150W, the pulse width is 2~5ms, and the duration of the heat preservation section is 25~35s; The peak temperature range is 320~330℃, the laser power is 30~60W, and the pulse width is 3~8ms. The range of single-pulse energy in the preheating section, peak section, and heat preservation section is 0.1~0.8J.

4. The metal mask plate repair method according to claim 1, characterized in that, In the step of using a pulsed laser to fuse the welding material with the metal mask to form a weld point, the minimum spot diameter of the pulsed laser is controlled at 0.2 mm, corresponding to a weld point diameter of 0.1~0.3 mm and a welding depth of 0.1~0.3 mm; the weld point diameter is 0.01~0.02 mm larger than the defect width, and the maximum weld point diameter does not exceed 0.3 mm.

5. The metal mask plate repair method according to claim 4, characterized in that, The lateral offset of the weld point is less than 1 / 3 of the defect width; the height of the weld point extends to 1 / 4 of the height of the interface between the welding material and the metal mask plate, and does not exceed 0.05mm above the surface of the metal mask plate; the welding width at the end of the weld point is at least 2 / 3 of the defect width.

6. The metal mask plate repair method according to claim 1, characterized in that, Welding material is applied to the defective area, including: Welding material is applied to the defective area using a squeegee printing method. The printing thickness is matched to the depth of the defective area. The printing pressure is controlled at 0.1~0.3MPa, and the squeegee moving speed is 20~50mm / s.

7. The metal mask plate repair method according to claim 6, characterized in that, The welding materials include lead-free solder paste and flux.

8. The metal mask repair method according to claim 1, characterized in that, The step of inspecting the size and edge shape of each etched hole on the metal mask to determine the defect location of the etched hole includes: Position the metal mask on the support platform of the automated optical inspection equipment; The automated optical inspection equipment is controlled to identify the size and edge shape of each etched hole and determine the defect location of the etched hole.

9. The metal mask plate repair method according to claim 1, characterized in that, The step of obtaining the height by which the solder joint protrudes from the metal mask plate, and grinding the solder joint flat according to the height, includes: The height of the solder joint protruding from the metal mask plate was measured using a white light interferometer. When the height was greater than 5... At that time, the protruding parts are ground flat so that the solder joints are flush with the metal mask plate.

10. A metal mask, characterized in that, This includes metal masks prepared by the metal mask repair method according to any one of claims 1-9.

Images