Fmm repair agent and repair method

Abstract

The application discloses a FMM repair agent and a repair method, and relates to the technical field of semiconductors. The sintering temperature of the FMM repair agent is 250-350 DEG C. The FMM repair agent comprises 45-60 wt% of metal powder, wherein the melting point of the metal powder is lower than the sintering temperature; 10-15 wt% of ferrite magnetic powder; 7-15 wt% of thermoplastic adhesive, wherein the decomposition temperature of the thermoplastic adhesive is lower than the melting point of the metal powder; and 15-21.5 wt% of viscosity regulator. The FMM repair agent can form a stable repair structure after sintering.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically to an FMM repair agent and repair method. Background Technology

[0002] Fine Metal Mask (FMM) is a core material in the OLED display manufacturing process, and its main function is to achieve precise transfer of patterns during the vapor deposition process.

[0003] The finished FMM (Follicular Unit Molding) has several vapor-deposited holes, which are usually formed by chemical etching. However, during the FMM forming process, over-etching can occur, resulting in abnormally large vapor-deposited holes, or even interconnected holes. Due to the high production cost of FMMs, to reduce losses, defects in the finished FMM are currently repaired. This typically involves adding a metal material that can be sintered at a relatively low temperature (50–80°C) to the defective area, followed by sintering and solidification. Because the sintering temperature of the metal material is low, rapid repair is possible, ensuring that the shape of the formed metal material closely matches the expected shape.

[0004] However, FMM still requires subsequent high-temperature cleaning (temperature between 40 and 60°C) and hot air drying (50 to 75°C). During these processing steps, the metal material filling the repair position may melt and deform, resulting in defects such as opening deformation and depression at the repair position during the vapor deposition process.

[0005] If a metal paste with a higher sintering temperature is selected, the FMM is more likely to deform due to heat during the sintering process. Summary of the Invention

[0006] This invention aims to address one of the technical problems in related technologies to a certain extent. To this end, this invention provides an FMM repair agent, which, after sintering, forms a repair structure with high stability.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An FMM repair agent, wherein the sintering temperature of the FMM repair agent is between 250°C and 350°C, the FMM repair agent comprising:

[0009] 45wt% to 60wt% of metal powder, wherein the melting point of the metal powder is lower than the sintering temperature;

[0010] 10wt%~15wt% ferrite magnetic powder;

[0011] 7wt% to 15wt% of a thermoplastic adhesive, wherein the decomposition temperature of the thermoplastic adhesive is lower than the melting point of the metal powder;

[0012] Viscosity modifiers ranging from 15 wt% to 21.5 wt%.

[0013] This invention discloses an FMM repair agent for repairing defects in finished FMM products. The repair is achieved by injecting the repair agent into the defective areas. The repair agent comprises metal powder, ferrite magnetic powder, thermoplastic adhesive, and a viscosity modifier. Since FMM is made of metallic materials, the defect repair structure formed by the sintering of the metal powder and ferrite magnetic powder constitutes the main body of the FMM, ensuring that the performance of the repaired defective area is consistent with that of the intact areas. The thermoplastic adhesive allows the repair agent to adhere to the defective areas, and the viscosity modifier adjusts the viscosity of both the repair agent and the thermoplastic adhesive, ensuring that the shape of the repaired FMM remains unchanged for a short period after injection.

[0014] The sintering temperature of FMM repair compound is between 250℃ and 350℃. When FMM is heated to this temperature, the thermoplastic adhesive and viscosity modifier completely disappear, leaving only the metal components. Due to the disappearance of the thermoplastic adhesive and viscosity modifier, a porous structure is formed between the metal components. The metal powder can melt at this temperature to fill the pores. The ferrite magnetic powder, with a melting point much higher than 350℃, will not melt, forming the framework of the defect repair structure, and its magnetism will not disappear to match the magnetism of the FMM. The finished FMM will not deform at this temperature. During sintering, because the decomposition temperature of the thermoplastic adhesive is lower than the melting point of the metal powder, the thermoplastic adhesive will melt and decompose before the metal powder, creating pores that are then continuously filled by the subsequently melting metal powder. After sintering, the FMM repair agent leaves only the metal components, which can maintain structural stability and a strong bond with the FMM during the subsequent high-temperature cleaning and hot air drying processes.

[0015] The main component of thermoplastic adhesives is thermoplastic material. Therefore, after the viscosity modifier in the FMM repair agent is reduced, the thermoplastic material molecules will aggregate and cross-link to form a dense and strong solid film to fix the metal component. The FMM repair agent can then be cured and shaped at the defective part of the FMM without flowing freely, so as to facilitate subsequent sintering and forming a repair structure that is close to the preset shape.

[0016] Optionally, the metal powder is tin powder, and the mass ratio of the tin powder to the ferrite magnetic powder is 3:1 to 4:1.

[0017] Optionally, the thermoplastic adhesive is a polyvinyl alcohol solution with a mass concentration of 50% to 83.3%, and the solvent of the polyvinyl alcohol solution is glycerol. The thermoplastic adhesive includes polyvinyl alcohol and glycerol, with glycerol serving as the solvent for polyvinyl alcohol. Polyvinyl alcohol, as the main adhesive, has hydroxyl groups on its molecular chains that can form hydrogen bonds with the surface of the FMM finished product. After drying at room temperature or by heating, the thermoplastic adhesive forms a dense and strong adhesive film, which solidifies the FMM repair agent and prevents it from flowing, facilitating the transfer and sintering of the FMM. It also prevents the FMM repair agent from flowing and affecting its shape after sintering, thus improving the repair quality. Glycerol, as a small-molecule plasticizer, can embed itself between the polyvinyl alcohol fiber molecular chains, weakening intermolecular forces and improving the flexibility, folding resistance, and adhesion of the adhesive film. It also slows down the drying speed of the adhesive film, extending the construction period.

[0018] Optionally, the solvent of the viscosity modifier is deionized water, and the solute of the viscosity modifier is cellulose and / or ammonium polyacrylate, wherein the mass concentration of cellulose is 1.95% to 2.45%, and the mass concentration of ammonium polyacrylate is 2.6% to 4.3%. Deionized water is the main component of the viscosity modifier to adjust the viscosity of thermoplastic adhesives. The addition of cellulose can significantly increase the adhesive viscosity, delay water evaporation, and enhance the cohesiveness of the adhesive film. Ammonium polyacrylate can act as a dispersant in metal powders to prevent agglomeration, improve the quality after sintering, enhance the strength and density of the repaired structure after sintering, and reduce cracking and deformation. Ammonium polyacrylate begins to decompose at a temperature of 150°C, and at the sintering temperature, it is not easy for ammonium polyacrylate to remain as a residue.

[0019] Furthermore, the present invention also provides an FMM repair method, comprising:

[0020] A first surface and a second surface are provided on the FMM, and the FMM is provided with a plurality of vapor deposition holes penetrating the FMM along its thickness direction. The opening of the vapor deposition hole on the first surface is larger than the opening on the second surface.

[0021] Acquire a first image of the first surface and a second image of the second surface;

[0022] The first and second images are identified and analyzed to obtain over-etching defect information on the first and second surfaces;

[0023] Based on the overcut defect information, FMM repair agent is injected into the defective area and the injected FMM repair agent is cured. The FMM repair agent is the FMM repair agent mentioned above.

[0024] The FMM is heated to the sintering temperature to sinter the cured FMM repair agent into shape.

[0025] This invention also discloses an FMM repair method, which uses the aforementioned disclosed FMM repair agent to repair the finished FMM. The FMM has vapor deposition holes penetrating the first and second surfaces. Over-etching defects may exist on both the first and second surfaces. By acquiring images of the first and second surfaces, first and second images can be obtained. After image recognition and analysis, over-etching defect information (over-etching defects refer to vapor deposition holes that are too large or have interconnected holes; over-etching defect information includes the location, size, and number of over-etching defects) can be obtained on the first and second surfaces. After the FMM repair agent fills the defect area, it undergoes a curing process, which allows the injected FMM repair agent to solidify and form a shape. It not only maintains its shape but also maintains a certain bonding force with the FMM, preventing it from falling off as the FMM is transferred. The entire FMM is then heated to sinter the cured FMM repair agent, thereby repairing the FMM. Using the above-mentioned FMM repair agent for FMM repair can give the repaired FMM the same vapor deposition performance as a normal FMM. The beneficial effects of the FMM repair agent have been described above and will not be repeated here.

[0026] Optionally, the step of injecting FMM repair agent into the defective area based on the overcut defect information and curing the injected FMM repair agent includes:

[0027] Analyze the overcut defect information to obtain the location and specification information of the overcut defect;

[0028] Determine the main surface on which the overcut defect is located and the depth of the overcut defect on the FMM. If the overcut defect is located on the first surface or the depth of the overcut defect is not less than the set depth, select the first repair method to inject and cure the FMM repair agent on the defect area. If the overcut defect is located on the second surface and the depth of the overcut defect does not exceed the set depth, select the second repair method to inject and cure the FMM repair agent on the defect area.

[0029] Evaporated holes are formed by chemical etching. During the etching process, the amount of chemical reagent in contact with the first and second surfaces differs, resulting in different opening sizes of the evaporated holes. Consequently, the defect sizes on the first and second surfaces also differ, with the defect sizes on the first surface often being larger than those on the second surface. Furthermore, when over-etching defects are located on the second surface and have a large depth (i.e., the defect depth exceeds the set depth), they are also considered large-scale over-etching defects. Therefore, different repair methods exist for over-etching defects of different sizes to shorten the overall repair time of the FMM and reduce repair costs.

[0030] Optionally, the first repair method includes:

[0031] Select the first surface as the surface to be repaired;

[0032] Multiple layers of FMM repair agent are injected into the defective area. After each layer of FMM repair agent is injected, a curing process is performed on the injected FMM repair agent.

[0033] Evaporated holes are formed by etching with chemical reagents. Due to the difference in the amount of chemical reagents in contact with the first and second surfaces, evaporated holes with different opening degrees can be formed. The evaporated holes are divided into two parts: one part is formed by etching from the first surface to the second surface with chemical reagents, and the other part is formed by etching from the second surface to the first surface with chemical reagents. The two holes are connected to form a through evaporated hole. Ideally, the evaporated hole is a frustum-shaped hole whose diameter gradually decreases from the first surface to the second surface. In reality, because the shape of the evaporated hole is similar to the shape of the chemical droplets, the evaporated hole is divided into two-segment structures: one part is a large hole that gradually decreases from the first surface to the second surface, and the other part is a small hole that gradually decreases from the second surface to the first surface.

[0034] When the defect is located on the second surface and is deep, the defect extends from the small hole to the large hole. If the FMM repair agent is injected from the second surface to the defect, it is difficult to form a repair structure that tapers from the first surface to the second surface. Therefore, when the defect is large, the first surface is used as the surface to be repaired, and the FMM repair agent is injected into the defect from the large hole side of the vapor deposition hole.

[0035] Because FMM repair agent is a fluid with a certain degree of fluidity, to avoid excessive flow along the edges of the defect due to excessive injection at once, which could lead to a significant difference between the sintered repair structure and the expected shape, the FMM repair agent is injected in multiple stages. Each injection is followed by a curing process, allowing each injection to solidify and take shape. Through multiple injections and curing cycles, the FMM repair agent forms a shape similar to and maintains the expected repair structure, ensuring a consistent repair structure during sintering. The cured FMM repair agent bonds firmly to the FMM, and even moving the FMM before sintering will not cause the repair agent to detach.

[0036] By injecting and curing in multiple stages, the small amount of FMM repair agent injected each time can be quickly cured and shaped before its shape changes. The small amount of FMM repair agent itself is lightweight and its shape will not change for a short time after injection. Therefore, its shape after curing can be close to the shape at the time of injection. In this way, the repair structure formed after sintering can be the same as expected, improving the repair effect.

[0037] Optionally, injecting multiple layers of FMM repair agent into the defective area includes:

[0038] Calculate the injection volume, number of injection layers, and injection path of the FMM repair agent based on the specifications of the overcut defect;

[0039] Inject multiple layers of FMM repair agent into the defective area along the injection path and according to the number of injection layers;

[0040] The injection volume (V) of the FMM repair compound satisfies the following formula:

[0041] V = Defect area × Defect depth × Filling coefficient / Sintering rate

[0042] The number of injection layers (C) of FMM repair compound satisfies the following formula:

[0043] C = (Defect depth / Thickness of a single layer of FMM repair agent) + 1

[0044] The filling coefficient is 1 / 3 to 1, the sintering rate is 60% to 75%, and the thickness of a single layer of FMM repair agent is a constant.

[0045] By recognizing and analyzing the first image, comparing it with a normal image can detect overcutting defects. At the same time, the size information of the overcutting defects, including the area and depth of the overcutting defects, can be obtained. Based on the size information of the overcutting defects, the required injection amount of FMM repair agent and the corresponding number of injection layers can be calculated, and then the FMM repair agent can be injected according to the injection path.

[0046] Optionally, if the overcut defect is a hole enlargement defect, the injection path of the FMM repair agent is as follows:

[0047] Inject along the edge of the defect towards the center of the vapor deposition hole;

[0048] If the overcut defect is a through-hole defect, the injection path of the FMM repair agent is:

[0049] The lap structure is formed by injecting from one edge of the defect area between the two vapor deposition holes to the other edge;

[0050] Injection is carried out along the edge of the defect and the overlapping structure towards the center of the vapor deposition holes on both sides.

[0051] Over-etching defects are divided into enlarged hole defects and connected hole defects. Enlarged hole defects occur when excessive etching occurs at the edges of the vapor-deposited holes, resulting in an excessively large hole size. Connected hole defects occur when at least two vapor-deposited holes are connected due to excessive etching. The injection path of the FMM repair agent differs when repairing these two types of defects, but the first step in both is to connect the FMM repair agent to the edge of the defect area, providing support and load-bearing for the FMM repair agent within the solid structure, thus ensuring the FMM repair agent remains in the designated position.

[0052] Optionally, the calculation of the injection path of the FMM repair agent includes:

[0053] Based on the specifications of the over-etching defect and the set size of the vapor deposition hole, simulate the edge curve of the repaired vapor deposition hole;

[0054] Based on the simulated edge curve, the FMM repair agent injection area is planned to form the injection path.

[0055] The defect area on the FMM is connected to the vapor deposition holes. The entire defect area includes both normal vapor deposition holes and redundant missing parts. The injection path of the FMM repair agent is related to the shape of the over-etched defect. By simulating the edge of the normal vapor deposition hole and comparing it with the defect area, the edge shape of the missing part can be obtained. In this way, the edge shape can be fitted to the injection path of the FMM repair agent.

[0056] Optionally, the width of the upper FMM repair agent is 5µm to 10µm smaller than the width of the lower FMM repair agent. After the injection of multiple layers of FMM repair agent, a stepped structure can be formed. Because the FMM repair agent will collapse during the sintering process—the thermoplastic adhesive and viscosity modifier disappear during the sintering process, and the tin powder melts to fill the gaps created by the disappearance of the thermoplastic adhesive and viscosity modifier—the stepped structure between two adjacent FMM repair agents will become a relatively smooth transition structure, so that the final repair structure has an approximately conical shape. The most ideal shape for vapor-deposited holes is a conical hole. Therefore, the vapor-deposited holes repaired by the sintered repair structure can have better performance.

[0057] Optionally, the second repair method includes:

[0058] Select the second surface as the surface to be repaired;

[0059] Calculate the amount of FMM repair compound to be injected based on the specifications of the overcut defect;

[0060] Inject FMM repair agent into the center of the overcut defect, and then cure the FMM repair agent.

[0061] Compared to the vapor-deposited holes on the first surface, the vapor-deposited holes on the second surface are smaller and require less chemical reagents than those on the first surface. Therefore, the resulting defects are smaller in scale and can be filled directly by injecting FMM repair agent into the center of the over-cut defect. The FMM repair agent is then solidified during the curing process.

[0062] Optionally, the step of injecting FMM repair agent into the defective area and curing the injected FMM repair agent includes:

[0063] Infrared light is irradiated onto the defective area, and the FMM repair agent is cured by heating the defective area through infrared radiation.

[0064] The heating temperature shall not exceed 150℃.

[0065] Infrared radiation can be used to heat the local area of ​​FMM by irradiating it. This heating process causes the deionized water to evaporate, and the thermoplastic material molecules dissolved in the FMM repair agent will gradually aggregate and cross-link to form a dense and strong solid film, thereby fixing the metal powder.

[0066] 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

[0067] The present invention will be further described below with reference to the accompanying drawings:

[0068] Figure 1 These are comparison images of the FMM repair agent before and after curing in this invention;

[0069] Figure 2 This is a flowchart of the FMM repair method in this invention;

[0070] Figure 3 This is a comparison image of the finished FMM before and after the repair of over-etching defects in the present invention;

[0071] Figure 4 This is a detailed flowchart of step S40 in the present invention;

[0072] Figure 5 Flowchart for repairing over-etching defects on the first surface;

[0073] Figure 6 Flowchart for repairing over-etching defects on the second surface;

[0074] Figure 7 This is a detailed flowchart of the FMM repair method in this invention;

[0075] Figure 8 This is a schematic diagram of the defect repair device in this invention;

[0076] Figure 9 This is a schematic diagram of the sintering apparatus in this invention;

[0077] Figure 10 This is a schematic diagram of the repair agent injection unit in this invention;

[0078] Figure 11 This is a schematic diagram of the repair agent injection unit in this invention during the injection of FMM repair agent.

[0079] Figure label:

[0080] Vaporized hole 100, first surface 110, second surface 120;

[0081] Sintering device 200, sintering chamber 210, air inlet 220, air outlet 230, support plate 240;

[0082] Repair platform 300, repair component 310, repair agent injection unit 311, repair agent curing unit 312, ultrasonic cleaning unit 313;

[0083] The components include a cavity 400, a nozzle 410, an injection channel 420, a first piezoelectric ceramic 430, a vibrating plate 431, a second piezoelectric ceramic 440, a spray base 450, and a supplementary channel 460. Detailed Implementation

[0084] 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.

[0085] 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 invention. The phrase "in an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0086] This invention discloses an FMM repair agent for repairing over-etching defects (oversized vapor-deposited holes or interconnected holes caused by excessive etching) on ​​finished FMMs. Finished FMM (see reference) Figure 5 and Figure 6 A plurality of vapor-deposited holes 100 are formed on the FMM, penetrating the two opposing main surfaces of the FMM—the first surface 110 and the second surface 120—along the thickness direction. The FMM is prepared from a thin metal material through multiple processing steps. The vapor-deposited holes 100 are formed by etching the thin metal material with chemical reagents. During the etching process, there is a certain probability that the chemical reagents will come into contact with other parts of the thin metal material, thereby causing over-etching defects. The FMM repair agent repairs defects by injecting it into the defective area to fill the excess etched area on the FMM, and then forming it by sintering to combine it with the finished FMM product.

[0087] The sintering temperature of FMM repair agent is 250℃~350℃. FMM repair agent contains 55wt%~75wt% metal component, 7wt%~15wt% thermoplastic adhesive and 15wt%~21.5wt% viscosity modifier. The metal component is divided into 45wt%~60wt% metal powder and 10wt%~15wt% ferrite magnetic powder. The melting point of the metal powder is lower than the sintering temperature, and the decomposition temperature of the thermoplastic adhesive is lower than the melting point of the metal powder.

[0088] Metallic components can form the main structure of FMM after sintering. Thermoplastic adhesive is used to improve the bonding force between FMM repair agent and FMM. Viscosity modifier is used to adjust the viscosity of FMM repair agent. Thermoplastic adhesive is a solution of thermoplastic material.

[0089] The FMM repair compound contains metal powder, ferrite magnetic powder, thermoplastic adhesive, and viscosity modifier. FMM is made of metal materials. The defect repair structure formed by the metal powder and ferrite magnetic powder after sintering can constitute the main body of FMM, so that the performance of the repaired defect area is consistent with the performance of other intact parts. The thermoplastic adhesive enables the FMM repair compound to adhere to the defect area. The viscosity modifier is used to adjust the viscosity of FMM repair compound and thermoplastic adhesive, so that the shape of FMM repair compound after injection can remain unchanged for a short period of time.

[0090] like Figure 1 As shown, the sintering temperature of FMM repair agent is between 250℃ and 350℃. When FMM is heated to this temperature, the viscosity modifier will completely evaporate, and the thermoplastic material components in the thermoplastic adhesive will gradually decompose, leaving only the metal components. Due to the disappearance of the thermoplastic adhesive and viscosity modifier, a porous structure will form between the metal components. The metal powder can melt in the 250℃–350℃ environment to fill the pores. The ferrite magnetic powder, with a melting point much higher than 350℃, will not melt, forming the framework of the defect repair structure, and its magnetism will not disappear to match the magnetism of the FMM. The finished FMM will not deform in the 250℃–350℃ environment. During the sintering process, because the decomposition temperature of the thermoplastic adhesive is lower than the melting point of the metal powder, the thermoplastic adhesive will melt before the metal powder and begin to decompose and create pores, allowing the subsequently molten metal powder to continuously fill the pores. After sintering, the FMM repair agent leaves only metallic components, namely tin and ferrite. During subsequent high-temperature cleaning and hot air drying of the FMM, it maintains structural stability and a strong bond with the FMM. The preferred sintering temperature is 300℃.

[0091] The main component of thermoplastic adhesives is thermoplastic material. Therefore, when the viscosity modifier in the FMM repair agent is reduced, the thermoplastic material molecules will aggregate and cross-link to form a dense and strong solid film to fix the metal component. The FMM repair agent can then solidify and set at the defective area of ​​the FMM without flowing freely, facilitating subsequent sintering and forming a repair structure that closely matches the predetermined shape. When the FMM repair agent solidifies, it forms a certain porosity structure, which gradually increases and expands during the sintering process.

[0092] Specifically, the thermoplastic material is polyvinyl alcohol (or other thermoplastic materials), and the thermoplastic adhesive is a polyvinyl alcohol solution with a mass concentration of 50% to 83.3%. The solvent for the thermoplastic adhesive is glycerol. The thermoplastic adhesive includes polyvinyl alcohol and glycerol, with glycerol serving as the solvent for polyvinyl alcohol. Polyvinyl alcohol, as the main adhesive, has hydroxyl groups on its molecular chains that can form hydrogen bonds with the surface of the FMM finished product. After drying at room temperature or with heat, the thermoplastic adhesive forms a dense and strong film, which solidifies the FMM repair agent and prevents it from flowing, facilitating the transfer and sintering of the FMM. This also prevents the FMM repair agent from flowing and affecting its shape after sintering, thus improving the repair quality. Glycerol, as a small-molecule plasticizer, can embed itself between the polyvinyl alcohol fiber molecular chains, weakening intermolecular forces and improving the flexibility, folding resistance, and adhesion of the film. It also slows down the drying speed of the film, extending the construction period.

[0093] The solvent for the viscosity modifier is deionized water, and the solute is cellulose and / or ammonium polyacrylate. The mass concentration of cellulose is 1.95%–2.45%, and the mass concentration of ammonium polyacrylate is 2.6%–4.3%. The viscosity modifier may also consist of only one of cellulose and ammonium polyacrylate, or only deionized water. Deionized water is the main component of the viscosity modifier to adjust the viscosity of thermoplastic adhesives. The addition of cellulose can significantly increase the adhesive viscosity, delay water evaporation, and enhance the cohesiveness of the adhesive film. Ammonium polyacrylate can act as a dispersant in metal powders to prevent agglomeration, improve the quality after sintering, enhance the strength and density of repaired structures after sintering, and reduce cracking and deformation. Ammonium polyacrylate begins to decompose at a temperature of 150°C, and it is not easy for it to leave residues at the sintering temperature. The cellulose is sodium carboxymethyl cellulose (CMCNa) or carboxymethyl cellulose (CMC).

[0094] The metal powder is tin powder, and the mass ratio of tin powder to ferrite magnetic powder is 3:1 to 4:1.

[0095] Preferably, the composition of the FMM repair agent is: 70 wt% metal, 8 wt% polyvinyl alcohol, 18 wt% deionized water, and the remaining components are adjusted according to the injection effect of the FMM repair agent.

[0096] The preparation method for FMM repair compound is as follows:

[0097] Step 1: Prepare a polyvinyl alcohol solution (thermoplastic adhesive). Based on the ratio of polyvinyl alcohol to glycerin, place the corresponding weights of the material in a water bath and heat to 100°C, stirring continuously for 3–5 hours until the polyvinyl alcohol is completely dissolved.

[0098] Step 2: Prepare an aqueous solution of ammonium polyacrylate / cellulose (viscosity modifier): Mix the three components (ammonium polyacrylate, cellulose, and deionized water) according to their proportions and stir for 1-2 hours to completely dissolve the ammonium polyacrylate and cellulose.

[0099] Step 3: Mix the powders (tin powder and ferrite magnetic powder), thermoplastic adhesive, and viscosity modifier. Stir the mixed solution for 1-2 hours to ensure uniform dispersion of the metal components, thus obtaining the FMM repair agent.

[0100] The present invention also discloses an FMM repair method and an FMM repair device, wherein finished FMMs with over-cut defects are repaired on the FMM repair device by the FMM repair method.

[0101] The repair process of FMM mainly includes three steps: defect detection, injection and curing of FMM repair agent, and sintering and shaping of FMM repair agent. (Refer to...) Figure 8 and Figure 9 The FMM repair equipment includes a defect identification device, a defect repair device, and a sintering device 200, the functions of which correspond to the three stages mentioned above. The defect identification device is used to identify and analyze over-cut defects on the FMM, the defect repair device is used to fill and cure the defective areas on the FMM with FMM repair agent, and the sintering device 200 is used to heat the FMM to sinter the filled FMM repair agent. The FMM undergoes three processing steps sequentially through the aforementioned three devices: defect detection, FMM repair agent injection and curing, and FMM repair agent sintering. During the repair process, the FMM needs to be transferred between these three devices. During the transfer from the defect repair device to the sintering device 200, the FMM repair agent is cured by the defect repair device, which fixes the shape of the FMM repair agent and makes it firmly bonded to the FMM. Therefore, it will not fall off, shift, or deform from the FMM during the transfer process. The sintering device 200 can heat the entire FMM and sinter the FMM repair agent for multiple defective areas at the same time. The temperature of the sintering device 200 is controlled at 250℃~350℃ (preferably 300℃), which will not cause the FMM to deform due to heat and will also maintain the magnetism of the FMM repair agent.

[0102] Reference Figure 2 The FMM repair method includes the following steps:

[0103] S10, provides FMM;

[0104] S20, acquire a first image of the first surface 110 and a second image of the second surface 120;

[0105] S30, the first image and the second image are identified and analyzed to obtain over-etching defect information on the first surface 110 and the second surface 120;

[0106] S40, Based on the overcut defect information, inject FMM repair agent into the defect area and perform curing treatment on the injected FMM repair agent;

[0107] S50 heats the FMM to the sintering temperature, causing the cured FMM repair agent to sinter and take shape.

[0108] A comparison before and after defect repair can be referenced. Figure 3 .

[0109] Before being sent to the FMM repair equipment, the FMM has undergone over-cutting defect detection. Over-cutting defects can exist on both the first surface 110 and the second surface 120. The over-cutting defect detection step in steps S20-S30 obtains specific information about the over-cutting defects, including their location, quantity, and size. By acquiring images of the first surface 110 and the second surface 120, first and second images can be obtained. After image recognition and analysis, the over-cutting defect information on the first surface 110 and the second surface 120 can be obtained. After the FMM repair agent fills the defect area, it undergoes a curing process, allowing the injected FMM repair agent to solidify and form a shape that not only maintains its shape but also maintains a certain bonding force with the FMM. During the transfer of the FMM to the sintering device 200, the FMM repair agent can be transferred without falling off. The entire FMM is then heated to sinter the cured FMM repair agent, thereby repairing the FMM. Using the above-mentioned FMM repair agent for FMM repair allows the repaired FMM to have the same vapor deposition performance as a normal FMM. The beneficial effects of FMM repair agent on repairing FMM have been described in the above text and will not be repeated here.

[0110] Reference Figure 4 Based on the above embodiments, in one embodiment of the present invention, step S40 includes:

[0111] S41, Analyze the overcut defect information to obtain the location and specification information of the overcut defect;

[0112] S42, determine the main surface on which the overcut defect is located and the depth of the overcut defect on the FMM. If the overcut defect is located on the first surface 110 or the depth of the overcut defect is not less than the set depth, select the first repair method to inject and cure the FMM repair agent on the defect area. If the overcut defect is located on the second surface 120 and the depth of the overcut defect does not exceed the set depth, select the second repair method to inject and cure the FMM repair agent on the defect area.

[0113] The vapor-deposited holes 100 are formed by chemical etching. During the etching process, the amount of chemical reagents in contact with the first surface 110 and the second surface 120 is different, so the opening degree of the vapor-deposited holes 100 is also different. Based on this, the defect scale on the first surface 110 and the second surface 120 is also different. The defect scale on the first surface 110 is often larger than the defect scale on the second surface 120. In addition, when the over-etching defect is located on the second surface 120 and has a large depth (i.e. the defect depth exceeds the set depth), it is also considered a large-scale over-etching defect. Therefore, there are different repair methods for over-etching defects of different scales in order to shorten the repair time of the entire FMM and reduce the repair cost.

[0114] Whether the over-etching defect is located on the first surface 110 or the second surface 120 can be determined based on the size of the opening of the vapor deposition hole 100 on the main surface.

[0115] Reference Figure 4 , Figure 5 and Figure 6 Based on the above embodiments, in one embodiment of the present invention, the first repair method in step S43 includes:

[0116] S43A1, Select the first surface 110 as the surface to be repaired;

[0117] S43A2 involves injecting multiple layers of FMM repair agent into the defective area, and performing a curing treatment on the injected FMM repair agent after each layer is injected.

[0118] When making repairs, place the object to be repaired face up.

[0119] The vapor-deposited holes 100 are formed by chemical etching. Due to the difference in the amount of chemical reagent in contact with the first surface 110 and the second surface 120, vapor-deposited holes 100 with different opening degrees can be formed. The vapor-deposited holes 100 are divided into two parts: one part is a large hole formed by chemical etching from the first surface 110 to the second surface 120, and the other part is a small hole formed by chemical etching from the second surface 120 to the first surface 110. The large hole and the small hole are connected to form a through vapor-deposited hole 100. Ideally, the vapor-deposited hole 100 is a frustum-shaped hole whose diameter gradually decreases from the first surface 110 to the second surface 120. In reality, because the shape of the vapor-deposited hole 100 is similar to the shape of a chemical droplet, the formed vapor-deposited hole 100 is divided into two-section structures: one section of large hole gradually decreases from the first surface to the second surface, and the other section of small hole gradually decreases from the second surface to the first surface.

[0120] When the defect is located on the second surface 120 and has a large depth, the defect extends from the small hole to the large hole. If the FMM repair agent is injected into the defect from the second surface 120, it is difficult to form a repair structure that tapers from the first surface 110 to the second surface 120. Therefore, when the defect is large, the first surface 110 is used as the surface to be repaired, and the FMM repair agent is injected into the defect from the large hole side of the vapor deposition hole 100.

[0121] Because FMM repair agent is a fluid with a certain degree of fluidity, to avoid injecting too much FMM repair agent at once and causing it to flow excessively downwards along the edges of the defect, resulting in a repair structure that deviates significantly from the expected shape after sintering, the FMM repair agent is injected in multiple stages. Each injection is followed by a curing process, allowing each injected portion to solidify and take shape. Through multiple injections and curing cycles, the FMM repair agent forms a shape similar to and maintains the expected repair structure, ensuring a consistent repair structure during sintering. The cured FMM repair agent bonds firmly to the FMM, and even moving the FMM before sintering will not cause the repair agent to detach.

[0122] By injecting and curing in multiple stages, the small amount of FMM repair agent injected each time can be quickly cured and shaped before its shape changes. The small amount of FMM repair agent itself is lightweight and its shape will not change for a short time after injection. Therefore, its shape after curing can be close to the shape at the time of injection. In this way, the repair structure formed after sintering can be the same as expected, improving the repair effect.

[0123] like Figure 5 As shown, Figure 5The over-etching defect present in the figure is a hole-connection defect. The area selected by the dashed box in the upper left corner of the figure is the missing part. The vapor deposition holes 100 on both sides of the dashed box are directly connected to form a large hole-connection. The two entities in the dashed box are the structures that a normal FMM should actually have. Because of the missing part, the two structures are formed in the dashed box by FMM repair agent to repair the hole-connection and divide the hole-connection into three vapor deposition holes 100.

[0124] The second repair method in step S43 includes:

[0125] S43B1, Select the second surface 120 as the surface to be repaired;

[0126] S43B2, Calculate the injection amount of FMM repair agent based on the specifications of the overcut defect;

[0127] S43B3 involves injecting FMM repair agent into the center of the overcut defect, followed by curing the FMM repair agent.

[0128] Compared to the vapor deposition holes 100 on the first surface 110, the vapor deposition holes 100 on the second surface 120 have smaller openings and require less chemical reagents than the first surface 110. Therefore, the resulting defect size is also smaller, and FMM repair agent can be directly injected into the center of the overcut defect for filling. The FMM repair agent is then fixed during the curing process.

[0129] The repair structure formed by the second repair method is a vertical surface in the axial direction of the vapor deposition hole 100. The resulting hole has better vapor deposition performance compared to the original structure that tapers from the second surface 120 to the first surface 110.

[0130] In the above, the set depth for over-etching defects refers to whether the defect depth exceeds the junction of the large and small holes. When the etching depth of the second surface 120 exceeds the set depth, it means that the defect has reached the large hole from the second surface, and a cone angle needs to be formed during the repair process. Figure 5 and Figure 6 As shown, Figure 5 and Figure 6 The dotted line in the diagram is the dividing line between the large hole and the small hole. When the defect on the second surface 120 exceeds the dividing line, it means that the defect needs to be repaired using the first repair method.

[0131] Reference Figure 6 , Figure 6 That is, the process of repairing over-etched defects on the second surface 120.

[0132] Based on the above embodiments, in one embodiment of the present invention, step S43A2, injecting a multilayer FMM repair agent into the defective area, includes the following steps:

[0133] S43A21, Calculate the injection volume, number of injection layers, and injection path of FMM repair agent according to the specifications of the overcut defect;

[0134] S43A22, injects multiple layers of FMM repair agent into the defective area along the injection path and according to the number of injection layers.

[0135] By identifying and analyzing the first image, comparing it with a normal image, overcutting defects can be detected. At the same time, the size information of the overcutting defects, including the area and depth of the overcutting defects, can be obtained. Based on the size information of the overcutting defects, the required injection amount of FMM repair agent and the corresponding number of injection layers can be calculated.

[0136] The injection volume (V) of the FMM repair compound satisfies the following formula:

[0137] V = Defect area × Defect depth × Filling coefficient / Sintering rate.

[0138] The filling coefficient is 1 / 3 to 1, the sintering rate is 60% to 75%, and the defect area and defect depth are directly identified. This formula is applicable to both the first and second repair methods. The filling coefficient is related to the opening size and opening cone angle of the vapor-deposited hole 100. When the cone angle is 0 (the opening wall is a straight surface), the coefficient is 1.

[0139] The injection path also differs depending on the type of defect.

[0140] If the overcut defect is a hole enlargement defect, the injection path of the FMM repair agent is as follows:

[0141] Inject along the edge of the defect towards the center of the vapor deposition hole 100.

[0142] If the overcut defect is a through-hole defect, the injection path of the FMM repair agent is as follows:

[0143] The lap structure is formed by injecting from one edge of the defect between the two vapor deposition holes 100 to the other edge;

[0144] Inject along the edge of the defect and the overlapping structure into the center of the vapor deposition holes 100 on both sides.

[0145] Over-etching defects are divided into enlarged hole defects and connected hole defects. Enlarged hole defects occur when the edges of the vapor-deposited hole 100 are excessively etched, resulting in an excessively large opening size for the vapor-deposited hole 100. Connected hole defects occur when at least two vapor-deposited holes 100 are connected due to excessive etching. The injection path of the FMM repair agent differs when repairing these two types of defects, but the first step in both is to connect the FMM repair agent to the edge of the defect area, providing support and load-bearing for the FMM repair agent within the solid structure, thus ensuring the FMM repair agent remains in the designated position.

[0146] When dealing with the defects of interconnected holes, first overlap the FMM repair agent at the edge of the defect between the two vapor-deposited holes 100, then add more FMM repair agent in a serpentine path, or first add FMM repair agent towards the axis of one side of the vapor-deposited hole 100, and then add it to the other side. For example... Figure 3 As shown, Figure 3 The middle part is the hole defect. As can be seen from the figure, the area between the two vapor-deposited holes 100 has disappeared due to excessive etching. When injecting FMM repair agent, first inject it into one of the yellow circle areas, and then move it to the other yellow circle area so that the FMM repair agent can simultaneously overlap the solid structure on both sides of the defect area.

[0147] The number of injection layers (C) of FMM repair compound satisfies the following formula:

[0148] C = (Defect depth / Thickness of a single layer of FMM repair agent) + 1.

[0149] The thickness of a single layer of FMM repair agent is a fixed value.

[0150] like Figure 5 As shown, based on the above embodiments, in one embodiment of the present invention, ideally, the wall of the vapor-deposited hole 100 forms a tapered surface with a gradually decreasing diameter from the first surface 110 to the second surface 120. During the defect repair process on the first surface 110, in order to enable the sintered repair structure to form a certain tapered surface, the width of the upper FMM repair agent is 5µm to 10µm smaller than the width of the lower FMM repair agent.

[0151] Thus, after multiple layers of FMM repair compound are injected and cured, a stepped structure can be formed (from... Figure 1 As can also be seen, during the sintering process, the FMM repair agent will collapse—the thermoplastic adhesive and viscosity modifier disappear during the sintering process, and the tin powder melts to fill the gaps created after the thermoplastic adhesive and viscosity modifier disappear. In this way, the step structure between two adjacent FMM repair agents will become a relatively smooth transition structure, so that the final repair structure has an approximately conical shape. The vapor-deposited hole 100 repaired by the sintered repair structure can have better performance.

[0152] Based on the above embodiments, in one embodiment of the present invention, step S43A21, calculating the injection path of the FMM repair agent, includes:

[0153] Based on the specifications of the over-etching defect and the set dimensions of the vapor deposition hole 100, the edge curve of the repaired vapor deposition hole 100 is simulated.

[0154] Based on the simulated edge curve, the FMM repair agent injection area is planned to form the injection path.

[0155] The defect area on the FMM is connected to the vapor deposition hole 100. The entire defect area includes both the normal vapor deposition hole 100 and the redundant missing parts. The injection path of the FMM repair agent is related to the shape of the over-etched defect. By simulating the edge of the normal vapor deposition hole 100 and comparing it with the defect area, the edge shape of the missing part can be obtained. In this way, the edge shape can be fitted to the injection path of the FMM repair agent.

[0156] Step S43A21 actually includes three parallel steps S43A21A, S43A21B, and S43A21C, specifically:

[0157] S43A21A, calculate the injection amount of FMM repair agent according to the specifications of the overcut defect and the calculation formula of the injection volume (V);

[0158] S43A21B, calculate the number of FMM repair layers based on the specifications of the overcut defect and the calculation formula for the number of injection layers (C);

[0159] S43A21C1, based on the specifications of the over-etching defect and the set size of the vapor deposition hole 100, simulates the edge curve of the repaired vapor deposition hole 100;

[0160] S43A21C2, based on the simulated edge curve, plans the FMM repair agent injection area to form the injection path.

[0161] Based on the above embodiments, in one embodiment of the present invention, in step S40, infrared light is irradiated onto the defective area to heat the defective area through infrared radiation in order to cure the injected FMM repair agent.

[0162] The temperature of the defective area heated by infrared light shall not exceed 150℃.

[0163] Heating evaporates the deionized water, causing the polyvinyl alcohol molecules dissolved in the FMM repair agent to gradually aggregate and cross-link, forming a dense and strong solid film that fixes the metal powder. Polyvinyl alcohol has a melting point above 180℃; setting the infrared heating temperature to no more than 150℃ avoids damage to the solid film due to high temperatures, thus preventing interference with the curing process.

[0164] Infrared light can confine energy to a smaller area, improving energy utilization and thus quickly curing the FMM repair agent. It also avoids heating the FMM over a large area, which would waste energy and reduce the heating rate.

[0165] Based on the above embodiments, in one embodiment of the present invention, during the sintering process, the FMM is placed and heated with its first surface 110 facing upwards. During the sintering process, the tin powder melts, causing a certain amount of flow in the FMM repair agent. Because the first surface 110 faces upwards, a small portion of the FMM repair agent will flow downwards from the defect location to the small hole location of the vapor deposition hole 100, reducing the diameter of the small hole location.

[0166] Reference Figure 7 Based on the above embodiments, in one embodiment of the present invention, after step S50, the method further includes:

[0167] S60: Re-inspect the repaired FMM to determine if rework is necessary.

[0168] Step S60 includes the following steps:

[0169] S61, acquire a third image of the first surface 110 and a fourth image of the second surface 120;

[0170] S62, perform identification and analysis on the third and fourth images to determine whether there is excess material in the original defect area. If so, remove and repair the material; if not, confirm that the FMM repair is complete.

[0171] If the inspection reveals that there is excess material in the defective area, the excess material can be removed by laser.

[0172] Based on the above embodiments, in one embodiment of the present invention, before injecting the FMM repair agent, the step of cleaning the defective area on the FMM is further included. After cleaning, particles attached to the defective area can be removed, improving the adhesion of the FMM repair agent to the defective area. The cleaning is performed using ultrasonic resonance cleaning, by spraying compressed air with ultrasonic vibrations onto the defective area.

[0173] Reference Figure 7 Based on the above embodiments, in one embodiment of the present invention, and in summary, the complete repair method includes the following steps:

[0174] S10, provides FMM;

[0175] S20, acquire a first image of the first surface 110 and a second image of the second surface 120;

[0176] S30, the first image and the second image are identified and analyzed to obtain over-etching defect information on the first surface 110 and the second surface 120;

[0177] S41, Analyze the overcut defect information to obtain the location and specification information of the overcut defect;

[0178] S42, determine the main surface of the overcut defect on the FMM and the depth of the overcut defect. If the overcut defect is located on the first surface 110 or the depth of the overcut defect is not less than the set depth, select the first repair method to inject and cure the FMM repair agent on the defect area. If the overcut defect is located on the second surface 120 and the depth of the overcut defect does not exceed the set depth, select the second repair method to inject and cure the FMM repair agent on the defect area.

[0179] S50 heats the FMM to sinter the cured FMM repair agent into shape.

[0180] S61, acquire a third image of the first surface 110 and a fourth image of the second surface 120;

[0181] S62, perform identification and analysis on the third and fourth images to determine whether there is excess material in the original defect area. If so, remove and repair the material; if not, confirm that the FMM repair is complete.

[0182] First repair method:

[0183] S43A1, Select the first surface as the surface to be repaired;

[0184] S43A11, Clean the defective area;

[0185] S43A2 involves injecting multiple layers of FMM repair agent into the defective area, and performing a curing treatment on the injected FMM repair agent after each layer is injected.

[0186] Second repair method:

[0187] S43B1, Select the second surface as the surface to be repaired;

[0188] S43B11, Clean the defective area;

[0189] S43B2, Calculate the injection amount of FMM repair agent based on the specifications of the overcut defect;

[0190] S43B3 involves injecting FMM repair agent into the center of the overcut defect, followed by curing the FMM repair agent.

[0191] Reference Figure 8 and Figure 9 Based on the above embodiments, in one embodiment of the present invention, the defect repair device includes a repair platform 300 and a repair component 310.

[0192] The repair platform 300 is used to place the FMM for injecting and curing the FMM repair agent. The repair platform 300 is made of quartz or glass and its surface is coated to prevent the FMM repair agent from sticking to the repair platform 300.

[0193] The repair component 310 is located above the repair platform 300 and includes a repair agent injection unit 311, a repair agent curing unit 312, and an ultrasonic cleaning unit 313. The repair agent injection unit 311 is used to inject FMM repair agent into the defective area on the FMM. The repair agent curing unit 312 can generate infrared light to cure the FMM repair agent in the defective area. The ultrasonic cleaning unit 313 is used to ultrasonically clean the defective area to improve the adhesion of the FMM repair agent to the defective area. The positions of the repair agent injection unit 311, the repair agent curing unit 312, and the ultrasonic cleaning unit 313 can be switched to each other, so that a curing process can be performed after each layer of FMM repair agent is injected.

[0194] During the repair process, the repair component 310 has only one of the functions of injection and curing. The function is switched by switching the positions of the repair agent injection unit 311 and the repair agent curing unit 312, so that the repair agent injection and repair agent curing parts of the repair component 310 on the FMM overlap. This reduces the alignment steps between the repair component 310 and the defective part on the FMM, and only one alignment is required.

[0195] Reference Figure 10 and Figure 11 Based on the above embodiments, in one embodiment of the present invention, the repair agent injection unit 311 includes a cavity 400 and a nozzle 410. The cavity 400 contains FMM repair agent, and the nozzle 410 includes an injection channel 420 communicating with the cavity 400. The repair agent injection unit 311 also includes a first piezoelectric ceramic 430 and a second piezoelectric ceramic 440. The piezoelectric ceramic can deform after conducting electricity. The direction and magnitude of the deformation of the piezoelectric ceramic are related to the direction and magnitude of the voltage. The first piezoelectric ceramic 430 is used to provide a quantitative amount of FMM repair agent from the cavity 400 to the nozzle 410. The second piezoelectric ceramic 440 is used to adjust the cross-sectional size of the injection channel 420. To facilitate the extrusion of the FMM repair agent, the temperature of the cavity 400 is stabilized at 80°C.

[0196] The repair agent injection unit 311 also includes a circuit module. The first piezoelectric ceramic 430 is electrically connected to the circuit module. The first piezoelectric ceramic 430 is located inside the cavity 400. The FMM repair agent is located in the space enclosed by the first piezoelectric ceramic 430 and the inner wall of the cavity 400. The repair agent injection unit 311 adjusts the voltage applied to the first piezoelectric ceramic 430 by the circuit module according to the size of the over-cut defect.

[0197] After deformation, the first piezoelectric ceramic 430 can squeeze the FMM repair agent in the cavity 400, causing the FMM repair agent to be squeezed out of the cavity 400 and injected into the defect area through the nozzle 410. After determining the size of the over-cut defect, the required amount of FMM repair agent to be injected can be calculated, and then the voltage input to the first piezoelectric ceramic 430 can be adjusted to control the deformation of the first piezoelectric ceramic 430, so as to precisely control the injected FMM repair agent dosage. A vibrating plate 431 is also provided in the cavity 400 and attached to the first piezoelectric ceramic 430. The vibrating plate 431 can deform synchronously with the deformation of the first piezoelectric ceramic 430, and the vibrating plate 431 keeps in contact with the FMM repair agent.

[0198] The nozzle 410 includes two relatively movable spray seats 450, forming an injection channel 420 between the two spray seats 450. Two second piezoelectric ceramics 440 are provided and connected to one of the spray seats 450 respectively, for driving the spray seats 450 to move to adjust the cross-sectional size of the injection channel 420. The second piezoelectric ceramics 440 are also electrically connected to the circuit module. The repair agent injection unit 311 adjusts the magnitude and direction of the voltage applied to the second piezoelectric ceramics 440 by the circuit module according to the size of the over-cut defect, so as to drive the two spray seats 450 to make relative movements to adjust the cross-sectional size of the injection channel 420.

[0199] After deformation, the second piezoelectric ceramic 440 can compress the spray holder 450, causing the spray holder 450 to move and adjust the distance between the two spray holders 450. This adjusts the cross-sectional size of the injection channel 420, ensuring that the cross-sectional size of the injection channel 420 matches the size of the over-cut defect. This prevents the FMM repair agent from being injected outside the over-cut defect before it is fully filled, thus affecting the repair of the over-cut defect. The voltage input to the second piezoelectric ceramic 440 is adjusted according to the size of the over-cut defect to regulate the deformation direction and amount of deformation of the piezoelectric ceramic, thereby enlarging or shrinking the injection channel 420.

[0200] The repair agent injection unit 311 also includes a supplementary channel 460 that connects to the cavity 400. The position of the first piezoelectric ceramic 430 in the cavity 400 remains unchanged. The supplementary channel 460 can replenish the FMM repair agent in the cavity 400 in a timely manner after the FMM repair agent in the cavity 400 is squeezed out by the first piezoelectric ceramic 430, so that the FMM repair agent is kept at a fixed amount, and the deformation of the first piezoelectric ceramic 430 is matched with the FMM repair agent injection amount.

[0201] Reference Figure 9Based on the above embodiments, in one embodiment of the present invention, the sintering apparatus 200 includes a sintering chamber 210, an air inlet 220 and an air outlet 230 respectively communicating with the sintering chamber 210. The FMM is heated in the sintering chamber 210. The air inlet 220 is used to introduce nitrogen into the sintering chamber 210 during the FMM heating process, and the air outlet 230 is used to discharge the waste gas in the sintering chamber 210 during the FMM heating process.

[0202] The sintering apparatus 200 includes a sintering chamber 210, an air inlet 220, and an air outlet 230. Nitrogen enters the sintering chamber 210 through the air inlet 220, causing the FMM to be heated and sintered in a nitrogen environment to prevent the FMM from reacting with oxygen and being oxidized in a high-temperature environment. At the same time, the waste gas formed by the decomposition and volatilization of thermoplastic adhesive and viscosity modifier in the FMM repair agent due to high temperature can be discharged from the sintering chamber 210 with the nitrogen through the air outlet 230, thereby improving the repair quality of the FMM.

[0203] Inside the sintering chamber 210, there are multiple support plates 240. Each support plate 240 can hold one FMM, so that multiple FMMs can be processed at the same time. The surface of the support plate 240 has a fluorine-containing coating to prevent the FMM repair agent from sticking to the support plate 240 when it is in the molten state, and to avoid deformation of the FMM due to adhesion when it is removed from the support plate 240.

[0204] Before sintering, the environment inside the sintering chamber 210 is adjusted to 120°C and kept at that temperature for 2 to 4 hours to allow the moisture in the FMM repair agent to evaporate completely. Then, nitrogen gas is introduced and the ambient temperature is heated to 200°C at a rate of 10°C / min. The temperature is then increased from 200°C to 300°C at a rate of 5°C / min. After holding at 300°C for 60 minutes, the sintering chamber 210 is cooled to room temperature, and the FMM is removed.

[0205] 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. An FMM repair agent, characterized in that, The sintering temperature of the FMM repair agent is between 250℃ and 350℃, and the FMM repair agent comprises: 45wt% to 60wt% of metal powder, wherein the melting point of the metal powder is lower than the sintering temperature; 10wt%~15wt% ferrite magnetic powder; 7wt% to 15wt% of a thermoplastic adhesive, wherein the decomposition temperature of the thermoplastic adhesive is lower than the melting point of the metal powder; Viscosity modifiers ranging from 15 wt% to 21.5 wt%; The metal powder is tin powder, and the mass ratio of the tin powder to the ferrite magnetic powder is 3:1 to 4:

1.

2. The FMM repair agent according to claim 1, characterized in that, The thermoplastic adhesive is a polyvinyl alcohol solution with a mass concentration of 50% to 83.3%, and the solvent of the polyvinyl alcohol solution is glycerol.

3. The FMM repair agent according to claim 2, characterized in that, The solvent of the viscosity modifier is deionized water, and the solute of the viscosity modifier is cellulose and / or ammonium polyacrylate, wherein the mass concentration of the cellulose is 1.95% to 2.45%, and the mass concentration of the ammonium polyacrylate is 2.6% to 4.3%.

4. An FMM repair method, characterized in that, include: An FMM is provided, the FMM having a first surface (110) and a second surface (120) disposed opposite to each other, the FMM having a plurality of vapor deposition holes (100) penetrating the FMM along its thickness direction, the opening of the vapor deposition holes (100) on the first surface (110) being larger than the opening on the second surface (120); Acquire a first image of the first surface (110) and a second image of the second surface (120); The first image and the second image are identified and analyzed to obtain over-etching defect information on the first surface (110) and the second surface (120); Based on the overcut defect information, FMM repair agent is injected into the defect area and the injected FMM repair agent is cured. The FMM repair agent is the FMM repair agent according to any one of claims 1 to 3. The FMM is heated to the sintering temperature to sinter the cured FMM repair agent into shape.

5. The FMM repair method according to claim 4, characterized in that, The step of injecting FMM repair agent into the defective area based on the overcut defect information and then curing the injected FMM repair agent includes: Analyze the overcut defect information to obtain the location and specification information of the overcut defect; Determine the main surface on which the overcut defect is located and the depth of the overcut defect on the FMM. If the overcut defect is located on the first surface (110) or the depth of the overcut defect is not less than the set depth, select the first repair method to inject and cure the FMM repair agent on the defect area. If the overcut defect is located on the second surface (120) and the depth of the overcut defect does not exceed the set depth, select the second repair method to inject and cure the FMM repair agent on the defect area.

6. The FMM repair method according to claim 5, characterized in that, The first repair method includes: Select the first surface (110) as the surface to be repaired; Multiple layers of FMM repair agent are injected into the defective area. After each layer of FMM repair agent is injected, a curing process is performed on the injected FMM repair agent.

7. The FMM repair method according to claim 6, characterized in that, The injection of multiple layers of FMM repair agent into the defective area includes: Calculate the injection volume, number of injection layers, and injection path of the FMM repair agent based on the specifications of the overcut defect; Inject multiple layers of FMM repair agent into the defective area along the injection path and according to the number of injection layers; The injection volume V of FMM repair compound satisfies the following formula: V = Defect area × Defect depth × Filling coefficient / Sintering rate The number of FMM repair layers C that can be injected satisfies the following formula: C = (Defect depth / Thickness of a single layer of FMM repair agent) + 1 The filling coefficient is 1 / 3 to 1, the sintering rate is 60% to 75%, and the thickness of a single layer of FMM repair agent is a constant.

8. The FMM repair method according to claim 7, characterized in that, The calculation of the FMM repair agent injection path includes: Based on the specifications of the over-etching defect and the set size of the vapor deposition hole (100), the edge curve of the repaired vapor deposition hole (100) is simulated; Based on the simulated edge curve, the FMM repair agent injection area is planned to form the injection path.

9. The FMM repair method according to claim 7, characterized in that, If the overcut defect is a hole enlargement defect, the injection path of the FMM repair agent is: Inject along the edge of the defect towards the center of the vapor deposition hole (100); If the overcut defect is a through-hole defect, the injection path of the FMM repair agent is: An overlapping structure is formed by injecting from one edge of the defect between the two vapor deposition holes (100) to the other edge; Injection is carried out along the edge of the defect and the overlapping structure into the center of the vapor deposition holes (100) on both sides.

10. The FMM repair method according to claim 6, characterized in that, The width of the upper FMM repair layer is 5µm to 10µm smaller than the width of the lower FMM repair layer.

11. The FMM repair method according to claim 5, characterized in that, The second repair method includes: Select the second surface (120) as the surface to be repaired; Calculate the amount of FMM repair compound to be injected based on the specifications of the overcut defect; Inject FMM repair agent into the center of the overcut defect, and then cure the FMM repair agent.

12. The FMM repair method according to any one of claims 4 to 11, characterized in that, The process of injecting FMM repair agent into the defective area and curing the injected FMM repair agent includes: Infrared light is irradiated onto the defective area, and the FMM repair agent is cured by heating the defective area through infrared radiation. The heating temperature shall not exceed 150℃.

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