CN112775587A

CN112775587A - Smokeless solder wire and preparation method thereof

Info

Publication number: CN112775587A
Application number: CN202110047440.2A
Authority: CN
Inventors: 邢璧元; 王寿银; 王超; 邢璧凡
Original assignee: Shenzhen Xinghongtai Tin Co ltd
Current assignee: Shenzhen Xinghongtai Tin Co ltd
Priority date: 2021-01-14
Filing date: 2021-01-14
Publication date: 2021-05-11
Anticipated expiration: 2041-01-14
Also published as: CN112775587B

Abstract

The application relates to a soldering tin technology, in particular to a smokeless soldering tin wire and a preparation method thereof. A smokeless tin wire comprises a tin solder alloy and smokeless soldering flux filled in the tin solder alloy, wherein the mass ratio of the tin solder alloy to the smokeless soldering flux is (97-98): (2-3), the smokeless soldering flux comprises a smokeless carrier and a flux-aid active agent, and the mass ratio of the smokeless carrier to the flux-aid active agent is (94-96): 5; the smokeless carrier is prepared from the following raw materials in parts by weight: 40-60 parts of cellulose, 20-30 parts of polyamide wax and 10-15 parts of ether solvent; the polyamide wax has an acid value of less than 10mgKOH/g and a density of 0.88-0.9g/cm³A mixture of the modified polyamide wax of (1). The application provides a smokeless solder wire does not produce smog during soldering tin, has eliminated poisonous harmful gas, is totally clean and tidy by the weldment behind the soldering tin, and the soldering bit is not blackened by the oxidation, and is difficult for producing the tin pearl that splashes, and wettability is good.

Description

Smokeless solder wire and preparation method thereof

Technical Field

The application relates to a soldering tin technology, in particular to a smokeless soldering tin wire and a preparation method thereof.

Background

With the rapid development of the electronic industry, the improvement of light weight, miniaturization and miniaturization of electronic products has more strict requirements on the quality of the electronic products, particularly the appearance of environment-friendly products, the tin-lead solder is required to be gradually replaced by the lead-free solder, and the current lead-free solder has a very fast development speed, particularly the lead-free ultrafine welding wire. In electronic packaging, solder wires are common solder materials used for hand soldering or semi-automated machine soldering. Solder wires are commonly used to electrically or mechanically connect electronic devices and electronic components.

At present, in the aspect of soldering tin application in the electronic and electrical industry, rosin is used as a smokeless carrier, and a small amount of smokeless soldering flux active ingredients are added to clean pad oxides of components to be soldered. However, the temperature resistance of the rosin can only reach 300 ℃, the temperature of the lead-free welding iron head needs to reach 360-450 ℃, and the rosin can be carbonized or incompletely carbonized at the temperature of 360-450 ℃, so that smoke is generated during soldering, the environment is affected, and the physical damage to soldering workers is increased.

In view of the above-mentioned related art, the applicant believes that solder wires currently prepared with rosin as a carrier have severe fumes in soldering.

Disclosure of Invention

In order to solve the problem that the solder wire generates smoke during soldering, the application provides the smokeless solder wire and the preparation method thereof.

In a first aspect, the application provides a smokeless solder wire, which is realized by adopting the following technical scheme:

a smokeless tin wire comprises a tin solder alloy and smokeless soldering flux filled in the tin solder alloy, wherein the mass ratio of the tin solder alloy to the smokeless soldering flux is (97-98): (2-3), the smokeless soldering flux comprises a smokeless carrier and a flux-aid active agent, and the mass ratio of the smokeless carrier to the flux-aid active agent is (94-96): 5; the smokeless carrier is prepared from the following raw materials in parts by weight: 40-60 parts of cellulose, 20-30 parts of polyamide wax and 10-15 parts of ether solvent; the polyamide wax has an acid value of less than 10mgKOH/g and a density of 0.88-0.9g/cm³The modified polyamide wax of (1), the polyamide wax having an acid value of less than 10mgKOH/g and a density of 0.88 to 0.9g/cm³The mass ratio of the modified polyamide wax (B) is 1: (1.2-1.6).

By adopting the technical scheme, the rosin is replaced by the smokeless carrier, and the high-temperature welding is carried outUnder connecing, not only do not produce smog, and the residue after the welding is more reliable than rosin, has effectively improved the wettability of smokeless soldering tin silk, has still reduced the tin pearl that splashes that the soldering tin in-process produced, has improved the yields of high temperature soldering tin. The thermal stability of the cellulose can be improved due to the hydrogen bond action between the polyamide wax and the cellulose, the interaction force between cellulose molecular chains is improved, and the strength and the heat resistance of the smokeless carrier are greatly improved due to the combined action of the reticular swelling structure of the polyamide wax and the six-membered pyranoid ring structure in the cellulose, so that the smokeless carrier is not easy to generate smoke. In particular, polyamide wax having an acid value of less than 10mgKOH/g and a density of 0.88 to 0.9g/cm are used³The modified polyamide wax is compounded, and the mass ratio of the modified polyamide wax to the modified polyamide wax is controlled to be 1: (1.2-1.6), the dispersion of cellulose in ether solvent can be improved, and the compatibility of the smokeless carrier and the fluxing activator is increased. The polyamide wax, the cellulose and the ether solvent act together, so that the smokeless carrier is not easy to burn, has good thermal stability and excellent thermoplasticity, does not easily generate smoke under high-temperature welding, has excellent alkali resistance, weak acid resistance and moisture absorption resistance, has more reliable residues after welding than rosin, greatly reduces the defective rate, and is clean and tidy in welded parts after soldering tin and free from oxidation and blackening of soldering iron heads.

Preferably, the cellulose is methyl cellulose and ethyl cellulose in a mass ratio of 1: (2-3) mixing.

Through adopting above-mentioned technical scheme, methyl cellulose and ethyl cellulose are compounded and are controlled two mass ratio in this application, can improve the solubility of system, have improved the thermal stability of system simultaneously, under the effect of polyamide wax, and is difficult to burn, not only does not produce smog during messenger's soldering tin, has eliminated poisonous and harmful gas, can also improve the wettability and the yields of smokeless soldering tin silk.

Preferably, the viscosity of the 2wt% aqueous solution of the methylcellulose at 20 ℃ is 1000-1800 mPa.s.

By adopting the technical scheme, the viscosity of the methyl cellulose is controlled, and the methyl cellulose with the viscosity of 1000-1800mPa.s of 2wt% aqueous solution at 20 ℃ is selected, so that the wettability can be improved, and bridging can be avoided.

Preferably, the ethyl cellulose has a DS of 47.5 to 49.5.

By adopting the technical scheme, the ethyl cellulose with DS of 47.5-49.5 is adopted, the solubility of the ethyl cellulose in an ether solvent can be improved, the wettability of the smokeless solder wire is improved, and when the methyl cellulose (the viscosity of a 2wt% aqueous solution at 20 ℃ is 1000-1800mPa.s) and the ethyl cellulose (the DS is 47.5-49.5) are compounded, the spreading of a tin solder alloy is facilitated under the combined action of the methyl cellulose and the polyamide wax, the empty soldering is avoided, the contact angle is obviously reduced, and the yield is also improved.

Preferably, the ether solvent is selected from one or more of dipropylene glycol methyl ether, dipropylene glycol ethyl ether and n-butyl ether; more preferably, the ether solvent is a mixture of dipropylene glycol methyl ether, dipropylene glycol ethyl ether and n-butyl ether.

By adopting the technical scheme, the composite smokeless welding flux is prepared by compounding the dipropylene glycol methyl ether, the dipropylene glycol ethyl ether and the n-butyl ether, so that the dissolubility of the methyl cellulose and the ethyl cellulose is better, and the compatibility of the smokeless carrier and the welding flux activator is greatly improved.

Preferably, the mass ratio of the dipropylene glycol methyl ether to the dipropylene glycol ethyl ether to the n-butyl ether is (5-7): (2-4): 1.

by adopting the technical scheme, the dipropylene glycol methyl ether, the dipropylene glycol ethyl ether and the n-butyl ether are compounded and the mass ratio of the dipropylene glycol methyl ether, the dipropylene glycol ethyl ether and the n-butyl ether is controlled to be (5-7): (2-4): 1, the dissolving uniformity of methyl cellulose, ethyl cellulose and polyamide wax can be promoted, the wettability of a system can be improved, the spreading of tin solder alloy is promoted, tin balls are not easy to splash, welding spots are full and bright, and the protection of residues of a smokeless carrier on the welding spots after welding is facilitated. In addition, the dipropylene glycol methyl ether, the dipropylene glycol ethyl ether and the polyamide wax act together, so that the respective uniformity of the smokeless soldering flux and the tin solder alloy is improved, and the storage stability of the smokeless soldering flux is also improved. The reason the inventor thinks may be: on one hand, the polyamide wax has a reticular swelling structure, and has excellent thixotropic property, sagging resistance and sedimentation resistance; on the other hand, the addition of dipropylene glycol methyl ether and dipropylene glycol ethyl ether further improves the strength and heat resistance of the polyamide wax, and effectively reduces the content of peroxide generated by n-butyl ether during storage.

Preferably, the preparation method of the smokeless carrier comprises the following steps: heating the ether solvent to 65 ℃ and preserving heat for 1h, adding the polyamide wax, stirring, finally adding the cellulose, and stirring until the cellulose is completely dissolved to obtain the smokeless carrier.

By adopting the technical scheme, the feeding sequence of the ether solvent, the polyamide wax and the cellulose is controlled, the solubility of the cellulose can be greatly improved, and the wettability and the thermal stability of the smokeless solder wire are further improved.

Preferably, the preparation method of the smokeless soldering flux comprises the following steps: heating the smokeless carrier to 100-145 ℃, adding the flux-assisting active agent, and uniformly stirring to obtain the smokeless soldering flux.

In a second aspect, the application provides a preparation method of a smokeless solder wire, which adopts the following technical scheme:

a preparation method of smokeless solder wire comprises the following steps:

s1: pouring smokeless soldering flux into the core of the tin solder alloy;

s2: and extruding and drawing wires to obtain the smokeless solder wires.

In summary, the present application has the following beneficial effects:

1. the smokeless carrier prepared from the polyamide wax, the cellulose and the ether solvent is not easy to burn, has good thermal stability and excellent thermoplasticity, is not easy to generate smoke under high-temperature welding, has excellent alkali resistance, weak acid resistance and moisture absorption resistance, is more reliable than rosin in residues after welding, reduces splashing tin beads generated in a soldering process, and improves the yield of high-temperature soldering tin; the smokeless carrier replaces rosin, no smoke is generated during soldering, toxic and harmful gas is eliminated, a soldered part is clean and tidy after soldering, a soldering bit is not oxidized and blackened, the body injury of soldering workers is reduced, and the environment protection is enhanced;

2. when the methyl cellulose (the viscosity of 2wt% aqueous solution at 20 ℃ is 1000-1800mPa.s) and the ethyl cellulose (the DS is 47.5-49.5) are compounded, the mass ratio of the methyl cellulose to the ethyl cellulose is controlled, the solubility of the ethyl cellulose in an ether solvent can be improved, the wettability of a smokeless solder wire is improved, and under the combined action of the ethyl cellulose and the polyamide wax, the spreading of a tin solder alloy is facilitated, the empty soldering and bridging are avoided, the contact angle is obviously reduced, and the yield is improved;

3. according to the soldering flux, the dipropylene glycol methyl ether, the dipropylene glycol ethyl ether and the n-butyl ether are compounded, the mass ratio of the dipropylene glycol methyl ether, the dipropylene glycol ethyl ether and the n-butyl ether is controlled, the dissolving uniformity of methyl cellulose, ethyl cellulose and polyamide wax can be promoted, the wettability of a system can be improved, the spreading of tin solder alloy is promoted, splashing tin beads are not easy to generate, welding spots are full and bright, and the protection of residues of a smokeless carrier on the welding spots after welding is facilitated.

Detailed Description

In order to solve the problem that the solder wire generates smoke during soldering, the ethyl cellulose adopted by the soldering tin wire has the effects of adhesion, filling, film forming and the like, has good thermal stability, can generate a tough film, but is easy to oxidize and degrade. In the research process, the applicant finds that the DS value of the ethyl cellulose influences the solubility, the water absorption, the mechanical property and the thermal property, the DS value of the ethyl cellulose is increased, the solubility of the ethyl cellulose in an organic solvent is increased, but the softening point and the moisture absorption of the ethyl cellulose are reduced, the thermal stability and the thermoplasticity of the smokeless carrier in the smokeless soldering flux are influenced, and the effect of the smokeless carrier is seriously influenced. In addition, ethyl cellulose is easy to discolor in a strong alkaline environment and under a heated condition, the alkali resistance of the smokeless carrier can be influenced, methyl cellulose is easy to salt out in a system, the wettability can be reduced, the spreading of tin solder alloy is not facilitated, the welded welding spot is basically not protected by residue of the smokeless carrier, the soldering iron head is easy to oxidize and blacken, the welded part is not clean after tin soldering, and the defective rate of the tin soldering is greatly increased. The present application is based on this.

The present application is described in further detail below with reference to preparation examples and examples.

Except for the smokeless carriers prepared in the preparation examples, the raw materials used in the preparation examples, examples and comparative examples of the present application were commercially available, and unless otherwise specified, the raw materials used in the respective preparation examples, examples and comparative examples of the present application were derived from the following table 1, and the raw materials not mentioned in the following table 1 were purchased from the pharmaceutical company chemical agents ltd.

TABLE 1

Preparation example

Preparation examples 1 to 23 provide a smokeless vehicle, and preparation example 1 is described below as an example.

The preparation example 1 provides a smokeless carrier, which comprises the following preparation steps: heating 10g diethylene glycol hexyl ether (CAS number: 112-59-4) to 65 ℃, keeping the temperature for 1h, adding 20g polyamide wax, stirring uniformly, finally adding 40g microcrystalline cellulose (model: 235486), and stirring until the microcrystalline cellulose is completely dissolved to obtain a smokeless carrier;

wherein the polyamide wax is prepared by mixing polyamide wax with the brand number of SUNMIDE 50 and polyamide wax with the brand number of MT 6900-20 according to the mass ratio of 1: 1.2.

Preparation examples 2 to 3, the same as preparation example 1, except that: the quality of the raw materials for preparing the smokeless carriers is different, and the quality is shown in table 2.

TABLE 2

Components	Preparation example 1	Preparation example 2	Preparation example 3
				Diethylene glycol hexyl ether (g)	10	15	12.5
Microcrystalline cellulose (g)	40	60	50
				Polyamide wax (g)	20	30	25

Preparation examples 4 to 5, the same as preparation example 3, except that: the polyamide waxes described differ in their composition and are shown in table 3.

TABLE 3

Preparation examples 6 to 11, the same as preparation example 5, were different only in that: the cellulose varied in type and composition, as shown in Table 4.

TABLE 4

Preparation examples 12 to 17, the same as preparation example 10, were different only in that: the ether solvents are different in kind and composition, and are shown in table 5.

TABLE 5

Preparation example	Ether solvent
		Preparation example 10	Diethylene glycol hexyl ether
Preparation example 12	Dipropylene glycol methyl ether
		Preparation example 13	Dipropylene glycol ethyl ether
Preparation example 14	N-butyl ether
		Preparation example 15	The weight ratio of dipropylene glycol methyl ether, dipropylene glycol ethyl ether and n-butyl ether is 5: 2:1 are mixed to form
Preparation example 16	Dipropylene glycol methyl ether, dipropylene glycol ethyl ether and n-butyl ether are mixed according to the mass ratio of 7:4: 1 are mixed to form
		Preparation example 17	Dipropylene glycol methyl ether, dipropylene glycol ethyl ether and n-butyl ether are mixed according to the mass ratio of 6: 3: 1 are mixed to form

Preparation 18, the same as preparation 1, except that: the polyamide wax with the mark of SUNMIDE 50 is replaced by the polyamide wax with the mark of PA-670.

Preparation 19, like preparation 1, differs only in that: the polyamide wax with the mark of MT 6900-20 is replaced by the polyamide wax with the mark of MT 6650.

Preparation 20, the same as preparation 1, except that: the mass ratio of the polyamide wax with the brand of SUNMIDE 50 to the polyamide wax with the brand of MT 6900-20 is 1: 0.

Preparation 21, the same as preparation 1, except that: the mass ratio of the polyamide wax with the brand of SUNMIDE 50 to the polyamide wax with the brand of MT 6900-20 is 0: 1.2.

Preparation 22, the same as preparation 1, except that: the mass ratio of the polyamide wax with the brand of SUNMIDE 50 to the polyamide wax with the brand of MT 6900-20 is 2: 1.

Preparation 23, the same as preparation 1, except that: no microcrystalline cellulose.

Examples

Examples 1-26 provide a smokeless solder wire, and example 1 is described below.

The smokeless solder wire provided by embodiment 1 is prepared by the following steps:

s0: heating 96g of the smokeless carrier prepared in preparation example 1 to 145 ℃ at the speed of 5 ℃/min, adding 5g of flux-assisting active agent, and uniformly stirring to obtain smokeless flux;

s1: setting the temperature of a rosin barrel at 140 ℃, the temperature of a rosin guide pipe at 145 ℃ and the temperature of a front beam of an extruder at 110 ℃, and injecting Sn while injecting smokeless soldering flux into a designed die under the action of the extruder_96.5Ag_3.0Cu_0.5The rosin diversion pipe is arranged in the alloy, and the smokeless soldering flux is poured into Sn_96.5Ag_3.0Cu_0.5Core (smokeless soldering flux, Sn)_96.5Ag_3.0Cu_0.5At a mass ratio of 3:97), the extrusion speed was set to 6 minutes for one tin bar;

s2: drawing the material extruded in the step S1 by a drawing machine by adopting a rolling and drawing technology, wherein the temperature of the drawing process is set to be 50 ℃, and the smokeless soldering tin wire with the diameter of 0.8mm is obtained;

the flux activator is prepared by mixing organic acid, cyclohexylamine hydrochloride (CAS number: 4998-76-9), an organic solvent, ethylene diamine tetraacetic acid (CAS number: 60-00-4) and an FSN-100 fluorine surfactant according to a mass ratio of 35:8:27:4:3, wherein the organic acid is prepared by mixing suberic acid (CAS number: 505-48-6), adipic acid (CAS number: 124-04-9) and maleic anhydride (CAS number: 108-31-6) according to a mass ratio of 20:15:3, and the organic solvent is prepared by mixing ethanol and phenoxyethanol (CAS number: 122-99-6) according to a mass ratio of 2.5: 1.

Examples 2-23, like example 1, differ only in that: the smokeless carriers (prepared in the preparation examples) were different and are shown in Table 6.

TABLE 6

Examples	Smokeless carrier	Examples	Smokeless carrier
				Example 1	Preparation example 1	Example 13	Preparation example 13
Example 2	Preparation example 2	Example 14	Preparation example 14
				Example 3	Preparation example 3	Example 15	Preparation example 15
Example 4	Preparation example 4	Example 16	Preparation example 16
				Example 5	Preparation example 5	Example 17	Preparation example 17
Example 6	Preparation example 6	Example 18	Preparation example 18
				Example 7	Preparation example 7	Example 19	Preparation example 19
Example 8	Preparation example 8	Example 20	Preparation example 20
				Example 9	Preparation example 9	Example 21	Preparation example 21
Example 10	Preparation example 10	Example 22	Preparation example 22
				Example 11	Preparation example 11	Example 23	Preparation example 23
Example 12	Preparation example 12	/	/

Example 24, the same as example 17, except that: the mass ratio of the tin solder alloy to the smokeless soldering flux is 98: 2.

example 25, like example 17, differs only in that: the mass ratio of the smokeless carrier to the welding-assistant active agent is 94: 5.

example 26, like example 17, differs only in that: the step S0 is different, specifically: and (3) heating 96g of the smokeless carrier prepared in the preparation example 1 to 100 ℃ at the speed of 5 ℃/min, adding 5g of the flux-assisting active agent, and uniformly stirring to obtain the smokeless soldering flux.

Comparative example

Comparative example 1 provides a solder wire, which is different from the solder wire of preparation example 1 only in that: the smokeless carrier prepared in preparation example 1 was replaced with water-white hydrogenated rosin (model: H103).

Performance test

The following performance tests were performed on the solder wires provided in examples 1 to 26 and comparative example 1 of the present application.

1. Smoke: the solder wires of examples 1 to 26 and comparative example 1 were subjected to a smoke test using the flux for lead-free soldering of SJ/T11389-.

2. Splashing property: the solder wires of examples 1 to 26 and comparative example 1 were subjected to a spattering test according to SJ/T11389-2009 lead-free soldering flux, the spattering degree was classified into 1 to 5, wherein 1 indicates no spattering, 5 indicates spattering, the smaller the value is, the more slight the spattering is, and the test results are shown in Table 7.

3. Wettability: the solder wires described in examples 1 to 26 and comparative example 1 were subjected to wettability testing using a French electric Meterometer ST78 ST88 type wetting balance and an HST-9 type constant temperature and humidity machine (available from Shanghai Temp electric Co., Ltd.) according to IPC TM 650 standard, each of which was tested 10 times, and the contact angles were averaged, and the results are shown in Table 7.

4. The defective rate is as follows: the solder wires described in examples 1 to 26 and comparative example 1 were each welded at 1000 points by using an automatic mechanical welding and HST-9 type constant temperature and humidity machine (purchased from Shanghai Shi electric appliances Co., Ltd.) at 400 ℃ in accordance with JIS Z3197 standards, and the occurrence of a void weld or bridging was marked as a defective product, and the number of defective products was recorded, and the defective product rate was counted, and the test results were shown in Table 7.

TABLE 7

The present application is described in detail below with reference to the test data provided in table 7.

As can be seen from the examples 1-5, the preparation examples 1-3 and the comparative example 1, the smokeless carrier prepared by the method can replace rosin, does not generate smoke under high-temperature welding, ensures that residues after welding are more reliable than the rosin, effectively improves the wettability of the smokeless solder wire, reduces splashing tin beads generated in the soldering process, and improves the yield of high-temperature soldering.

As can be seen from examples 1 and 23 and preparation examples 1 and 23 of the present application, the carrier prepared from cellulose is less likely to generate smoke, and is less likely to generate spattered tin beads during soldering, thereby significantly reducing the defective rate of high-temperature soldering.

From the examples 1 and 18-22 and the preparation examples 1 and 18-22, the polyamide wax with the brand number of SUNMIDE 50 and the polyamide wax with the brand number of MT 6900-20 are compounded and the mass ratio of the two is controlled, so that no smoke is generated, the splashing tin beads generated in the soldering process are reduced, the yield of high-temperature soldering tin is further improved, more importantly, the solubility of cellulose is improved, and the wettability of a smokeless solder wire is improved.

From the examples 5-11 and the preparation examples 5-11, it can be known that the wettability and the yield of the smokeless solder wire are improved compared with microcrystalline cellulose by compounding methyl cellulose and ethyl cellulose; the DS value of the ethyl cellulose is independently improved, although the contact angle is obviously reduced, the effect of improving the yield is not obvious, and the solubility of the ethyl cellulose with the low DS value in an ether solvent is poor, so that the wettability is reduced, and the empty welding is easy to occur; the adoption of high-viscosity methylcellulose can reduce the wettability and easily cause bridging; the contact angle and the defective rate were minimized at the same time only when the composition was made using methyl cellulose (viscosity of a 2wt% aqueous solution at 20 ℃ C. was 1400mPa. s) and ethyl cellulose (DS was 48.5).

From the examples 10 and 12-17 and the preparation examples 10 and 12-17, the dipropylene glycol methyl ether, the dipropylene glycol ethyl ether and the n-butyl ether are compounded and the mass ratio of the dipropylene glycol methyl ether, the dipropylene glycol ethyl ether and the n-butyl ether is controlled to be (5-7): (2-4): 1, not only the contact angle is obviously reduced, but also the defective product rates such as empty welding, bridging and the like are reduced, and the splashing tin beads generated in the tin soldering process are reduced.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims

1. A smokeless tin wire comprises a tin solder alloy and smokeless soldering flux filled in the tin solder alloy, wherein the mass ratio of the tin solder alloy to the smokeless soldering flux is (97-98): (2-3) characterized in thatThe smokeless soldering flux comprises a smokeless carrier and a flux-assisting active agent, wherein the mass ratio of the smokeless carrier to the flux-assisting active agent is (94-96): 5; the smokeless carrier is prepared from the following raw materials in parts by weight: 40-60 parts of cellulose, 20-30 parts of polyamide wax and 10-15 parts of ether solvent; the polyamide wax has an acid value of less than 10mgKOH/g and a density of 0.88-0.9g/cm³The modified polyamide wax of (1), the polyamide wax having an acid value of less than 10mgKOH/g and a density of 0.88 to 0.9g/cm³The mass ratio of the modified polyamide wax (B) is 1: (1.2-1.6).

2. The smokeless solder wire as claimed in claim 1, wherein the cellulose is methyl cellulose and ethyl cellulose in a mass ratio of 1: (2-3) mixing.

3. The smokeless solder wire of claim 2, wherein the methylcellulose has a viscosity of 1000-1800mpa.s in an aqueous solution containing 2wt% at 20 ℃.

4. The smokeless solder wire of claim 2 wherein the ethyl cellulose has a DS of 47.5 to 49.5.

5. The smokeless solder wire as claimed in claim 1, wherein the ether solvent is one or more selected from dipropylene glycol methyl ether, dipropylene glycol ethyl ether, and n-butyl ether.

6. The smokeless solder wire of claim 5, wherein the mass ratio of dipropylene glycol methyl ether, dipropylene glycol ethyl ether, and n-butyl ether is (5-7): (2-4): 1.

7. the smokeless solder wire of claim 1, wherein the preparation method of the smokeless carrier is as follows: heating the ether solvent to 65 ℃ and preserving heat for 1h, adding the polyamide wax, stirring, finally adding the cellulose, and stirring until the cellulose is completely dissolved to obtain the smokeless carrier.

8. The smokeless solder wire of claim 7, wherein the preparation method of the smokeless soldering flux comprises the following steps: heating the smokeless carrier to 100-145 ℃, adding the flux-assisting active agent, and uniformly stirring to obtain the smokeless soldering flux.

9. The method of preparing a smokeless solder wire of any one of claims 1-8, comprising the steps of:

s1: pouring smokeless soldering flux into the core of the tin solder alloy;

s2: and extruding and drawing wires to obtain the smokeless solder wires.