A water-washable semiconductor tin paste, a preparation method and application thereof

Abstract

The application relates to the technical field of welding materials, and discloses a water-washable semiconductor tin paste as well as a preparation method and application thereof. The water-washable semiconductor tin paste comprises a flux and tin powder, and the mass ratio of the flux to the tin powder is 1:(8-9.6); the raw material components of the flux comprise a film forming agent, a composite organic acid, a thixotropic agent, a surfactant, an antioxidant and a solvent; wherein the composite organic acid is composed of succinic acid and glutaric acid at a mass ratio of (1-3):(1-2.5). The water-washable semiconductor tin paste is prepared by controlling the particle size, melting point and alloy components of the tin powder, adopting the composite organic acid composed of the specific proportion of succinic acid and glutaric acid in the flux, and matching the other components; the specific mass proportion of the tin powder and the flux is combined, so that the prepared water-washable semiconductor tin paste has good wetting performance, the expansion rate is greater than or equal to 85%, the storage life reaches 3 months, the water-washable semiconductor tin paste can be directly cleaned by water after welding, and the corrosion resistance and the oxidation resistance are high.

Description

A water-washable semiconductor solder paste, its preparation method and application Technical Field

[0001] This application relates to the field of welding materials technology, and in particular to a water-washable semiconductor solder paste, its preparation method, and its application. Background Technology

[0002] In the electronics manufacturing industry, precision welding technology has always been a key driver of industry development. With the continuous advancement of semiconductor technology, the manufacturing of precision electronic components such as chip internal packaging, transistor internals, and IC chips places higher demands on welding materials and processes. Especially in semiconductor packaging and flip-chip packaging processes, achieving efficient, stable, and reliable welding is crucial for ensuring the performance and quality of electronic products. Good welding materials and processes can not only improve production efficiency but also effectively reduce production costs, propelling the electronics industry towards higher performance and smaller dimensions.

[0003] In existing technologies, common problems with semiconductor solder paste include water washing and solder joint oxidation, which are addressed by various methods. Regarding water washing performance, some solutions achieve lead-free washing by adjusting the carrier composition, such as using rosin amines in the carrier, hoping to effectively remove impurities during the washing process. For controlling micro-solder joint oxidation, the traditional method is to use a nitrogen-protected furnace, introducing nitrogen gas during reflow soldering to create an inert environment and prevent micro-solder joint oxidation.

[0004] However, on the one hand, while some water washing solutions can achieve lead-free washing, crystalline residues still remain after washing, affecting the reliability of precision packaging. On the other hand, solder with a specific melting point will undergo secondary melting inside at a specific reflow soldering temperature, leading to poor conductivity. At the same time, due to the small diameter of the solder powder, it is easy to oxidize during reflow soldering, resulting in minor incomplete solder melting. Conventional reflow ovens filled with nitrogen are costly and relatively complex to operate. Summary of the Invention

[0005] To at least overcome one of the problems existing in the prior art, one objective of this application is to provide a water-washable semiconductor solder paste. This water-washable semiconductor solder paste has advantages such as being easily washable after soldering and having strong oxidation resistance. It avoids problems such as corrosion of pre-packaged electronic semi-finished products by organic solvent cleaning, incomplete washing affecting product reliability, and partial oxidation of solder joints affecting product performance, thus meeting the requirements for semiconductor solder paste in practical use. A second objective of this application is to provide a method for preparing the aforementioned water-washable semiconductor solder paste. A third objective of this application is to provide applications of the aforementioned water-washable semiconductor solder paste.

[0006] Therefore, this application adopts the following technical solution:

[0007] The first aspect of this application provides a washable semiconductor solder paste, comprising flux and solder powder, wherein the mass ratio of flux to solder powder is 1:(8-9.6); the raw material components of the flux include: film-forming agent, composite organic acid, thixotropic agent, surfactant, antioxidant, and solvent; the composite organic acid is composed of succinic acid and glutaric acid in a mass ratio of (1-3):(1-2.5).

[0008] The flux to solder powder mass ratio is 1:(8-9.6), which gives the solder paste good soldering performance and formability, helps the flux to fully exert its function, effectively removes oxides from the soldering surface, and the appropriate solder powder content can form a strong solder joint. The composite organic acid is composed of succinic acid and glutaric acid in a specific mass ratio. Both succinic acid and glutaric acid are dicarboxylic acids, and their molecules contain two carboxyl groups (-COOH). The carboxyl group is a strongly polar group with weak acidity. The oxides on the surface of the solder and substrate are mostly basic or amphoteric oxides, which can undergo an acid-base neutralization reaction with the carboxyl groups of carboxylic acids to produce water. Metal ions combine with carboxyl groups to form soluble metal carboxylates. These soluble salts can be removed from the surface by the flux solvent or subsequent cleaning process, thereby effectively removing oxides from the surface of the solder and substrate, reducing surface tension, increasing the wettability between the solder paste and the substrate, improving solderability, and facilitating the washing of solder residues with water.

[0009] Preferably, the film-forming agent is selected from at least one of methyl isobutyl ketone, N-methylpyrrolidone, isophorone diisocyanate, and hexamethylene diisocyanate. More preferably, the film-forming agent is selected from at least one of methyl isobutyl ketone, N-methylpyrrolidone, and isophorone diisocyanate. Even more preferably, the film-forming agent is selected from at least one of methyl isobutyl ketone and N-methylpyrrolidone.

[0010] The film-forming agent is selected from at least one of methyl isobutyl ketone, N-methylpyrrolidone, isophorone diisocyanate, and hexamethylene diisocyanate. These film-forming agents can be activated under high temperature conditions and remove metal oxides from the surface of the solder and substrate in the form of resin acid salts, thereby enhancing the wettability of the molten metal. The formed organic film protects the metal surface with removed oxides from oxidation during the welding process, improving welding reliability. At the same time, it has electrical insulation properties and protects the solder joint.

[0011] Preferably, the thixotropic agent is selected from at least one of polyamide wax, fumed alumina, and polyethylene glycol stearate. More preferably, the thixotropic agent is selected from at least one of polyamide wax and fumed alumina. Even more preferably, the thixotropic agent is selected from polyamide wax.

[0012] Preferably, the surfactant is selected from at least one of Dynol 604, Surfynol 465, and Capstone FS-3100. More preferably, the surfactant is selected from at least one of Surfynol 465 and Capstone FS-3100. Even more preferably, the surfactant is selected from Capstone FS-3100.

[0013] Preferably, the antioxidant is selected from at least one of antioxidant 168, antioxidant 245, antioxidant 1010, and antioxidant 1076. More preferably, the antioxidant is selected from at least one of antioxidant 168, antioxidant 245, and antioxidant 1010. Even more preferably, the antioxidant is selected from at least one of antioxidant 168 and antioxidant 1010.

[0014] Preferably, the solvent is an alcohol solvent. More preferably, the solvent is selected from at least one of isopropanol, dipropylene glycol, 2-hexyl-1-decanol, and 2-hexyl-1,3-hexanediol.

[0015] Thixotropic agents impart thixotropic properties to solder paste, meaning that the paste exhibits lower viscosity under stress, facilitating printing, while maintaining its shape and preventing collapse under stress. Surfactants reduce the surface tension of the solder paste, allowing for better wetting of the soldering surface, improving its spreadability and flowability, and contributing to the formation of uniform and reliable solder joints. Antioxidants effectively inhibit oxidation reactions during storage and use, enhancing the stability of the solder paste and extending its lifespan. The solvent is an alcohol-based solvent, possessing excellent solubility, capable of dissolving other components in the flux, ensuring uniform mixing of all components. Furthermore, alcohol-based solvents are volatile, rapidly evaporating during soldering to reduce residue and improving the washability of the solder paste.

[0016] Preferably, the tin powder has a particle size of 5–12 μm and a melting point of 232–240 °C. More preferably, the tin powder has a particle size of 5–10 μm and a melting point of 235–240 °C. Even more preferably, the tin powder has a particle size of 5–8 μm and a melting point of 240 °C.

[0017] Preferably, the tin powder is a tin-antimony-nickel alloy, wherein the raw material composition of the tin-antimony-nickel alloy, by mass percentage, is 95-96% tin, 1.5-3% antimony, and the balance is nickel.

[0018] The tin powder has a particle size of 5–12 μm, which gives the solder paste good printability and solderability. The smaller particle size allows the solder paste to better fill solder gaps, improving soldering reliability. With a melting point of 232–240℃, it is suitable for most semiconductor soldering processes, enabling soldering at relatively low temperatures and reducing thermal damage to semiconductor devices. The tin powder is a tin-antimony-nickel alloy with specific proportions of each component. Tin provides good electrical conductivity and solderability, antimony improves the alloy's strength and hardness, and nickel enhances its corrosion resistance and oxidation resistance. The combination of these three components gives the solder joint good mechanical and electrical properties, improving the reliability and stability of the solder joint.

[0019] Preferably, the weight ratio of film-forming agent, composite organic acid, and thixotropic agent in the flux is (35-50):(6-11):(4-10).

[0020] Preferably, the weight ratio of film-forming agent, composite organic acid, thixotropic agent and surfactant in the flux is (35-50):(6-11):(4-10):(0.1-3.2).

[0021] Preferably, the weight ratio of film-forming agent, composite organic acid, thixotropic agent, surfactant and antioxidant in the flux is (35-50):(6-11):(4-10):(0.1-3.2):(2-7).

[0022] Preferably, the weight ratio of film-forming agent, composite organic acid, thixotropic agent, surfactant, antioxidant and solvent in the flux is (35-50):(6-11):(4-10):(0.1-3.2):(2-7):(30-40).

[0023] The specific weight proportions of each component in the flux allow for an optimal balance of flux performance. Specifically, a moderate content of film-forming agent effectively forms a protective film on the solder joints and improves oxidation resistance; composite organic acids ensure good fluxing effect and washability; thixotropic agents impart suitable thixotropic properties to the solder paste; surfactants ensure good wetting properties; antioxidants provide effective anti-oxidation; and solvents facilitate uniform mixing of the components and improve washability.

[0024] The second aspect of this application provides a method for preparing a washable semiconductor solder paste according to the first aspect of this application, comprising the following steps:

[0025] S1: Weigh the raw materials of each component of tin powder, mix them, melt them to 350℃ to form an alloy melt, centrifuge and atomize them to form spherical alloy particles, and then process them by rotating ultrasonic treatment and vibrating sieve to obtain tin-antimony-nickel alloy.

[0026] S2: Weigh the raw materials of each component of the flux, mix and stir to obtain the flux;

[0027] S3: Mix and stir the above-mentioned tin-antimony-nickel alloy and flux, and then stir under vacuum to obtain the washable semiconductor solder paste.

[0028] Preferably, in step S1, the power of the rotating ultrasound is 450–600W. More preferably, in step S1, the power of the rotating ultrasound is 480–600W. Even more preferably, in step S1, the power of the rotating ultrasound is 500–600W.

[0029] Preferably, in step S3, the stirring speed is 25-30 r / min, the stirring time is 35-50 min, the vacuum degree of the vacuum stirring is -0.09 MPa to -0.1 MPa, the vacuum stirring speed is 25-30 r / min, and the vacuum stirring time is 20-30 min. More preferably, in step S3, the stirring speed is 28-30 r / min, the stirring time is 40-50 min, the vacuum degree of the vacuum stirring is -0.09 MPa to -0.1 MPa, the vacuum stirring speed is 25-30 r / min, and the vacuum stirring time is 20-30 min. More preferably, in step S3, the stirring speed is 28-30 r / min, the stirring time is 40-50 min, the vacuum degree of the vacuum stirring is -0.09 MPa to -0.1 MPa, the vacuum stirring speed is 25-28 r / min, and the vacuum stirring time is 20-25 min.

[0030] In the preparation method of this application, the flux and tin alloy are prepared in steps, and then mixed and stirred to ensure that the components are fully mixed, thus ensuring the uniformity and stability of the solder paste quality. Step S1, by centrifugal atomization to form spherical alloy particles, ensures that the tin powder particles have a regular shape and good flowability, which is beneficial to the printing and soldering of the solder paste; rotary ultrasonic treatment can further refine the particles and improve particle uniformity; vibratory sieving ensures that the tin powder particle size meets the requirements. Step S3, by using vacuum stirring, can reduce the air mixed into the solder paste, improve the density and stability of the solder paste, and avoid the formation of pores during soldering.

[0031] The third aspect of this application provides a washable semiconductor solder paste for use in soldering materials, particularly in precision soldering materials, wherein the washable semiconductor solder paste is the aforementioned washable semiconductor solder paste or is prepared by the aforementioned preparation method.

[0032] Compared with the prior art, this application has at least the following beneficial effects:

[0033] 1) By rationally adjusting the mass ratio of flux to solder powder and the composition of each raw material in the flux, and using a specific ratio of succinic acid and glutaric acid to form a composite organic acid, oxides on the substrate surface are effectively removed, surface tension is reduced, wettability between the solder paste and the substrate is increased, soldering performance is improved, the solder joint is stronger, and solder residue is easier to wash off with water. The synergistic effect of film-forming agents, thixotropic agents, surfactants, antioxidants, and solvents ensures uniform mixing of all components, improving the washability, antioxidant properties, and wettability of the solder paste.

[0034] 2) By controlling the particle size, melting point and alloy composition of tin powder, the development needs of miniaturization and high performance of electronic products can be met, so that the solder joint has good mechanical and electrical properties, and the reliability and stability of the solder joint can be improved.

[0035] 3) The preparation process employs specific steps such as centrifugal atomization, rotary ultrasonication, and vacuum stirring. Through the optimization and control of parameters, the quality and performance of water-washable semiconductor solder paste are further improved, and the generation of soldering defects is reduced. Detailed Implementation

[0036] The following detailed description of the contents of this application is provided through specific embodiments, comparative examples, and tables, but is not limited to all the arguments and data.

[0037] Example of preparation of complex organic acids:

[0038] Preparation Example 1:

[0039] The preparation method of a complex organic acid involves the following steps:

[0040] Mix 1g of succinic acid and 1g of glutaric acid and stir to obtain a composite organic acid.

[0041] Preparation Example 2:

[0042] The preparation method of a complex organic acid involves the following steps:

[0043] 2.5g of succinic acid and 2g of glutaric acid were mixed and stirred to obtain a complex organic acid.

[0044] Preparation Example 3:

[0045] The preparation method of a complex organic acid involves the following steps:

[0046] 2.8g of succinic acid and 2.5g of glutaric acid were mixed and stirred to obtain a composite organic acid.

[0047] It is particularly important to emphasize that, unless otherwise specified, the raw materials, reagents or devices used in this application can be obtained from conventional commercial sources.

[0048] Table 1. Mass ratio of flux raw material components in washable semiconductor solder pastes of Examples 1-8 (unit: g)

[0049]

[0050]

[0051] Table 2. Mass ratio of flux raw material components in water-washable semiconductor solder pastes of Comparative Examples 1-3 (unit: g)

[0052]

[0053] Example 1:

[0054] A water-washable semiconductor solder paste is prepared by the following steps:

[0055] S1: Weigh 95g tin, 1.5g antimony, and 3.5g nickel, mix them, melt them to 350℃ to form an alloy melt, centrifuge and atomize them to form spherical alloy particles, and then treat them by rotation and ultrasound. Set the ultrasound power to 450W, vibrate and sieve to obtain a tin-antimony-nickel alloy with a particle size of 5-8μm and a melting point of 240℃.

[0056] S2: Weigh 40g of methyl isobutyl ketone, 6g of the composite organic acid from Preparation Example 1, 7g of polyamide wax, 1.5g of Dynol 604, 4.2g of antioxidant 168, and 35g of isopropanol, mix them, stir evenly, and obtain the flux.

[0057] S3: Mix 85g of tin-antimony-nickel alloy and 10g of flux, stir at 25r / min for 50min, clean the residue, and vacuum stir at -0.1MPa vacuum and 25r / min for 30min to obtain water-washable semiconductor solder paste.

[0058] Example 2:

[0059] A method for preparing a washable semiconductor solder paste is the same as in Example 1, except that the types and quality of the flux raw materials are added according to Example 2.

[0060] Example 3:

[0061] A method for preparing a washable semiconductor solder paste is the same as in Example 1, except that the types and quality of the flux raw materials are added in accordance with those in Example 3.

[0062] Example 4:

[0063] A method for preparing a washable semiconductor solder paste is the same as in Example 1, except that the types and quality of the flux raw materials are added according to Example 4.

[0064] Example 5:

[0065] A method for preparing a washable semiconductor solder paste is the same as in Example 1, except that the types and quality of the flux raw materials are added according to Example 5.

[0066] Example 6:

[0067] A method for preparing a washable semiconductor solder paste is the same as in Example 1, except that the types and quality of the flux raw materials are added according to Example 6.

[0068] Example 7:

[0069] A water-washable semiconductor solder paste is prepared by the following steps:

[0070] S1: Weigh 95.5g tin, 2g antimony, and 2.5g nickel, mix them, melt them to 350℃ to form an alloy melt, centrifuge and atomize them to form spherical alloy particles, and then treat them by rotational ultrasound with an ultrasonic power of 500W and vibrating sieve to obtain a tin-antimony-nickel alloy with a particle size of 5-8μm and a melting point of 238℃.

[0071] S2: Weigh 45g N-methylpyrrolidone, 7g of the composite organic acid of Preparation Example 3, 8g of fumed alumina, 2g Surfynol 465, 5g of antioxidant 245, and 40g of dipropylene glycol, mix them, stir evenly, and obtain the flux.

[0072] S3: Mix 90g of tin-antimony-nickel alloy and 10g of flux, stir at 30r / min for 45min, clean the residue, and vacuum stir at -0.09MPa vacuum and 30r / min for 25min to obtain water-washable semiconductor solder paste.

[0073] Example 8:

[0074] A water-washable semiconductor solder paste is prepared by the following steps:

[0075] S1: Weigh 96g of tin, 2.5g of antimony, and 1.5g of nickel, mix them, melt them to 350℃ to form an alloy melt, centrifuge and atomize them to form spherical alloy particles, and then treat them by rotation and ultrasound. Set the ultrasound power to 550W, vibrate and sieve to obtain a tin-antimony-nickel alloy with a particle size of 5-8μm and a melting point of 240℃.

[0076] S2: Weigh 48g of isophorone diisocyanate, 10g of the composite organic acid of Preparation Example 3, 9g of polyethylene glycol stearate, 3g of Capstone FS-3100, 6.5g of antioxidant 1010, and 40g of 2-hexyl-1-decyl alcohol, mix them, stir evenly, and obtain the flux.

[0077] S3: Mix 91g of tin-antimony-nickel alloy and 10g of flux, stir at 30r / min for 50min, clean the residue, and vacuum stir at -0.1MPa vacuum and 28r / min for 30min to obtain water-washable semiconductor solder paste.

[0078] Comparative Example 1:

[0079] A method for preparing a washable semiconductor solder paste is the same as in Example 1, except that the types and quality of the flux raw materials are added according to Comparative Example 1.

[0080] Comparative Example 2:

[0081] A method for preparing a washable semiconductor solder paste is the same as in Example 1, except that the types and quality of the flux raw materials are added according to Comparative Example 2.

[0082] Comparative Example 3:

[0083] A method for preparing a washable semiconductor solder paste is the same as in Example 1, except that the types and quality of the flux raw materials are added according to Comparative Example 3.

[0084] Material performance testing:

[0085] The washable semiconductor solder pastes obtained in Examples 1-8 and Comparative Examples 1-3 were subjected to various performance tests, and the test methods are as follows:

[0086] Cleaning effect: After welding, the residue is directly washed with water to check if it is clean.

[0087] Lifespan: Store at 0-10℃. Take it out monthly to observe for stratification (separation of solder powder and flux) and sedimentation (hard lumps at the bottom). Record the storage time. When stratification or clumping appears and cannot be restored to uniformity by stirring, the lifespan ends.

[0088] Expansion rate: Tested according to JIS Z 3197 standard.

[0089] Copper plate corrosion: Test according to SJ / T 11389.

[0090] Antioxidant properties: Store at room temperature for one week and test for oxidation.

[0091] The test performance of the washable semiconductor solder pastes of Examples 1-8 and Comparative Examples 1-3 is shown in Table 3 below:

[0092] Table 3 shows the performance test results of Examples 1-8 and Comparative Examples 1-3.

[0093] Cleaning Effect Lifespan Extension Rate (%) Copper Plate Corrosion Oxidation Resistance Example 1 Clean 3 months 85.2 No corrosion or oxidation Example 2 Clean 3 months 86.7 No corrosion or oxidation Example 3 Clean 3 months 84.9 No corrosion or oxidation Example 4 Clean 3 months 86.3 No corrosion or oxidation Example 5 Clean 3 months 85.1 No corrosion or oxidation Example 6 Clean 3 months 85.3 No corrosion or oxidation Example 7 Clean 3 months 85.4 No corrosion or oxidation Example 8 Clean 3 months 85.8 No corrosion or oxidation Comparative Example 1 Clean 3 months 84.5 Slight corrosion or slight oxidation Comparative Example 2 Not clean 2 months 87.1 Slight corrosion or slight oxidation Comparative Example 3 Clean 3 months 86.6 Slight corrosion or oxidation surface

[0094] The washable semiconductor solder pastes in Examples 1-8 are produced by controlling the particle size, melting point, and alloy composition of the tin powder, using a specific ratio of succinic acid and glutaric acid in the flux, and combining film-forming agents, thixotropic agents, surfactants, antioxidants, and solvents. The specific mass ratio of tin powder and flux results in washable semiconductor solder pastes with good wetting properties, a spread rate ≥85%, and a shelf life of up to 3 months. After soldering, it can be directly cleaned with water, avoiding the substrate corrosion problems caused by cleaning with organic solvents. In addition, no corrosion was observed in the copper plate corrosion test, and no oxidation occurred after a week of storage at room temperature, indicating that the washable semiconductor solder pastes of this application have strong corrosion resistance and oxidation resistance.

[0095] Compared with Example 1, the organic acid in Comparative Example 1 was succinic acid, a single acid from the composite organic acid in Example 1. Other types, amounts, and process conditions were the same as in Example 1. The results showed that the solder paste in Comparative Example 1 was clean after washing with water after soldering and had a shelf life of 3 months. However, its spread rate was not as good as that of the solder paste in Example 1. Furthermore, the copper plate corrosion test of Comparative Example 1 showed slight corrosion, and slight oxidation occurred after being stored at room temperature for one week. This indicates that the effect of using a single acid in the flux is not as good as the effect of the composite organic acid used in the formulation of this application.

[0096] Compared with Example 1, Comparative Example 2 used glutaric acid, a single acid from the composite organic acid in Example 1, as the organic acid. Other types, amounts, and process conditions were the same as in Example 1. The results showed that the solder paste spread rate of Comparative Example 2 reached 87.1%, but the shelf life was only 2 months. After soldering, the residue was not completely removed by water washing, and slight corrosion was observed in the copper plate corrosion test. Slight oxidation was observed after one week of storage at room temperature. This indicates that the effect of using a single acid in the flux is not as good as the composite organic acid used in the formulation of this application.

[0097] Compared with Example 1, Comparative Example 3 used an organic acid composed of citric acid and glutaric acid in a mass ratio of 3:2. Other types, amounts, and process conditions were the same as in Example 1. The results showed that the solder paste of Comparative Example 3 was clean after washing with water, had a shelf life of 3 months, an expansion rate of 86.6%, and no oxidation occurred after one week of storage at room temperature. However, slight corrosion was observed in the copper plate corrosion test. The organic acid in the flux of Comparative Example 3 was a composite organic acid, but it still could not achieve the effect of the composite organic acid used in the formulation of this application.

[0098] Therefore, the composite organic acid of this application can effectively remove oxides from the solder and substrate surfaces, reduce surface tension, increase the wettability between the solder paste and the substrate, and improve the solderability, corrosion resistance, and oxidation resistance of the water-washable semiconductor solder paste through the synergistic effect of the various raw materials. Furthermore, the water-washable semiconductor solder paste of this application has strong water-washability, and residues after soldering can be directly cleaned with water.

[0099] Obviously, the above embodiments of this application are merely examples for clearly illustrating this application, and are not intended to limit the implementation of this application. For those skilled in the art, other variations or modifications can be made based on the above description. Any obvious variations or modifications derived from the technical solutions of this application are still within the protection scope of this application.

Claims

1. A washable semiconductor solder paste, characterized in that, The flux comprises flux and solder powder, wherein the mass ratio of flux to solder powder is 1:(8~9.6); the raw material components of the flux include: film-forming agent, composite organic acid, thixotropic agent, surfactant, antioxidant, and solvent; the composite organic acid is composed of succinic acid and glutaric acid in a mass ratio of (1~3):(1~2.5); the flux comprises the following raw material components in parts by weight: film-forming agent 35~50 parts; composite organic acid 6~11 parts; thixotropic agent 4~10 parts; surfactant 0.1~3.2 parts; antioxidant 2~7 parts; solvent 30~40 parts.

2. The washable semiconductor solder paste according to claim 1, characterized in that, The film-forming agent is selected from at least one of methyl isobutyl ketone, N-methylpyrrolidone, isophorone diisocyanate, and hexamethylene diisocyanate.

3. The washable semiconductor solder paste according to claim 1, characterized in that, The thixotropic agent is selected from at least one of polyamide wax, fumed alumina, and polyethylene glycol stearate; and / or the surfactant is selected from at least one of Dynol 604, Surfynol 465, and Capstone FS-3100.

4. The washable semiconductor solder paste according to claim 1, characterized in that, The antioxidant is selected from at least one of antioxidant 168, antioxidant 245, antioxidant 1010, and antioxidant 1076; and / or the solvent is an alcohol solvent.

5. The washable semiconductor solder paste according to claim 1, characterized in that, The tin powder has a particle size of 5~12μm and a melting point of 232~240℃.

6. The washable semiconductor solder paste according to claim 1, characterized in that, The tin powder is a tin-antimony-nickel alloy, wherein the raw material composition of the tin-antimony-nickel alloy, by mass percentage, is 95-96% tin, 1.5-3% antimony, and the balance is nickel.

7. The application of a washable semiconductor solder paste as described in any one of claims 1 to 6 in soldering materials.

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