阅读说明：本技术 含锌免钎剂焊锡丝及其制备方法 (Zinc-containing soldering tin wire free of soldering flux and preparation method thereof ) 是由 黄鲁江 夏杰 赵图强 于 2021-10-13 设计创作，主要内容包括：本发明公开了一种含锌免钎剂焊锡丝及其制备方法,按质量百分比计,所述焊锡丝包括3％-7％的第一组份和93％-97％的第二组份；第一组份包括40％-60％的水性聚酰胺酰亚胺树脂水溶液和60％-40％的锌铜化合物粉末；第二组分包括98％的电解锡、1.4％的电解铋和0.6％的电解银；其中水性聚酰胺酰亚胺树脂水溶液中水性聚酰胺酰亚胺树脂的质量百分含量为3％,所述锌化合物粉末的颗粒度为0.5-1.2微米；电解锡的纯度为99.5％,电解铋和电解银的纯度为99％。本发明所获得的一种含锌免钎剂焊锡丝,可适用于各种电子元器件组装焊接,能够满足铜基焊件及镀镍、镀银、镀金等多种合金组份焊件,其成品经径可生产0.8mm-3.5mm的焊锡丝成品,应用范围广,适用性强。(The invention discloses a zinc-containing soldering-flux-free solder wire and a preparation method thereof, wherein the solder wire comprises 3-7% of a first component and 93-97% of a second component by mass percentage; the first component comprises 40-60% of aqueous polyamide-imide resin solution and 60-40% of zinc-copper compound powder; the second component comprises 98 percent of electrolytic tin, 1.4 percent of electrolytic bismuth and 0.6 percent of electrolytic silver; wherein the mass percentage of the water-based polyamide-imide resin in the water-based polyamide-imide resin water solution is 3 percent, and the granularity of the zinc compound powder is 0.5-1.2 microns; the purity of the electrolytic tin is 99.5%, and the purity of the electrolytic bismuth and the electrolytic silver is 99%. The solder wire containing zinc and free of soldering flux obtained by the invention is suitable for assembling and welding various electronic components, can meet requirements of copper-based welding parts and welding parts with multiple alloy components such as nickel plating, silver plating, gold plating and the like, can produce solder wire finished products with the diameter of 0.8-3.5 mm, and has wide application range and strong applicability.)

1. A zinc-containing soldering-flux-free solder wire is characterized in that: according to the mass percentage, the paint comprises 10-20% of a first component and 80-90% of a second component;

the first component consists of 40-60% of aqueous polyamide-imide resin aqueous solution and 60-40% of zinc-copper compound powder, wherein the mass percentage of the aqueous polyamide-imide resin in the aqueous polyamide-imide resin aqueous solution is 3%, and the granularity of the zinc-copper compound powder is 0.8-1.2 microns;

the second component is electrolytic tin with a purity of 99.95%.

2. The solder-free solder wire containing zinc according to claim 1, characterized in that: the zinc-copper compound at least comprises the following components: cu₅Zn₈、CuZn。

3. A method for preparing a zinc free flux solder wire according to any of claims 1 to 2, characterized in that it comprises the following steps:

step 1, uniformly mixing a material aqueous polyamide imide resin solution in a first component with zinc-copper compound powder, heating to 90-105 ℃, and keeping continuously stirring to obtain a first component;

step 2, pouring the uniformly mixed first component into a pressure injection barrel with heat preservation and stirring functions for later use;

step 3, weighing the electrolytic tin in the second component, putting the weighed electrolytic tin into an intermediate frequency heating furnace, keeping the temperature within the range of 380-400 ℃, and continuously stirring for 2 hours to obtain the second component;

step 4, casting the second component into a section to be extruded, and cooling for later use;

step 5, putting the extruded section obtained in the step 4 into an extruder for extrusion, pressing the uniformly mixed first component into a second component through a pressurized and sealed injection barrel, wherein the pressing proportion is controlled to be 10-20% through a flow regulating valve, and the pressing proportion is the mass proportion of the first component to the second component;

and 6, controlling the thickness of the wire diameter of the extruded product through a wire drawing die, and reaching the final required wire diameter to obtain the solder wire finished product without the soldering flux.

Technical Field

The invention relates to a solder wire without soldering flux used in the technical field of electronic welding production, in particular to a solder wire without soldering flux containing zinc and a preparation method thereof.

Background

The soldering tin wire is used as a main welding material for assembling in the electronic welding industry, the welding quality and reliability are firstly ensured, and the quality of the soldering tin wire directly influences the service life of an assembled product.

At present, a soldering tin wire used in the electronic industry at home and abroad can complete the soldering process only by assisting a certain soldering flux, the soldering flux is necessary to be arranged inside the soldering tin wire or coated with the soldering flux in the soldering process, and the main components of the soldering flux are rosin-based soldering flux and various organic acid activators. Because of the existence of organic acid activators, the activators are not easy to completely decompose in the high-speed welding process and remain on the surface of a weldment together with rosin, and active ingredients in the residues are easy to chemically react with the weldment or a welding point when meeting a high-temperature or humid environment, so that the welding point is continuously corroded, and the service life of a product is influenced.

Disclosure of Invention

In order to overcome the defects, the invention provides the zinc-containing soldering-flux-free solder wire and the preparation method thereof, which can effectively improve the service life and reliability of a welding spot or a weldment while ensuring the welding effect.

The technical scheme adopted by the invention for solving the technical problem is as follows: a zinc solder-free solder wire comprises, by mass, 10-20% of a first component and 80-90% of a second component; the first component consists of 40-60% of aqueous polyamide-imide resin aqueous solution and 60-40% of zinc-copper compound powder, wherein the mass percentage of the aqueous polyamide-imide resin in the aqueous polyamide-imide resin aqueous solution is 3%, and the granularity of the zinc-copper compound powder is 0.8-1.2 microns; the second component is electrolytic tin with a purity of 99.95%.

As a further improvement of the invention, the zinc-copper compound at least comprises the following components: cu₅Zn₈、CuZn。

The invention also provides a preparation method of the zinc-containing solder-free solder wire, which is characterized by comprising the following steps:

step 1, uniformly mixing a material aqueous polyamide imide resin solution in a first component with zinc-copper compound powder, heating to 90-105 ℃, and keeping continuously stirring to obtain a first component;

step 2, pouring the uniformly mixed first component into a pressure injection barrel with heat preservation and stirring functions for later use;

step 3, weighing the electrolytic tin in the second component, putting the weighed electrolytic tin into an intermediate frequency heating furnace, keeping the temperature within the range of 380-400 ℃, and continuously stirring for 2 hours to obtain the second component;

step 4, casting the second component into a section to be extruded, and cooling for later use;

step 5, putting the extruded section obtained in the step 4 into an extruder for extrusion, pressing the uniformly mixed first component into a second component through a pressurized and sealed injection barrel, wherein the pressing proportion is controlled to be 10-20% through a flow regulating valve, and the pressing proportion is the mass proportion of the first component to the second component;

and 6, controlling the thickness of the wire diameter of the extruded product through a wire drawing die, and reaching the final required wire diameter to obtain the solder wire finished product without the soldering flux.

The invention has the beneficial effects that: the invention adopts the water-based polyamide-imide resin and the zinc-copper compound as auxiliary materials of the soldering-flux-free solder wire, the function of the soldering-flux-free solder wire can replace the traditional rosin soldering flux, the wettability is good in the welding process, and an intermetallic compound layer (namely an IMC layer and a soldered joint) can be formed with the tin alloy solder and the soldered alloy in a very short time; the traditional welding process utilizes the function of the soldering flux, under the condition of continuous welding high temperature, the formation of intermetallic compounds is also promoted, and the main component of the formed intermetallic compounds is just the zinc-copper compound; meanwhile, after welding, the soldered joint has no residues, and the reliability of the soldered joint is effectively improved. The added zinc and silver elements can effectively improve the heat conductivity and the electric conductivity of the solder and reduce the self-energy consumption of products. In a word, the formula and the process are simple, and the service life and the reliability of the traditional rosin-type solder wire after welding are improved.

Detailed Description

The technical solution of the present invention will be described in detail with reference to examples.

Example 1:

a zinc-containing solder-free solder wire comprises, by mass, 10% of a first component and 90% of a second component;

weighing a first component comprising 4Kg of 3 percent aqueous polyamide-imide resin solution and 6Kg of zinc-copper compound powder;

weighing 100Kg of second component electrolytic tin with the purity of 99.95%;

wherein the mass percentage of the water-based polyamide-imide resin in the water-based polyamide-imide resin water solution is 3 percent, the median particle size of the zinc-copper compound powder is 1.0 micron, and the zinc-copper compound powder at least comprises the following components: cu₅Zn₈、CuZn。

The preparation method comprises the following steps:

step 1, uniformly mixing a weighed aqueous polyamide-imide resin solution in the first component with zinc-copper compound powder, heating to 90-105 ℃, and keeping continuously stirring to obtain a first component;

step 2, pouring the uniformly mixed first component into a pressure injection barrel with heat preservation and stirring functions for later use;

step 3, weighing the electrolytic tin, the electrolytic bismuth and the electrolytic silver in the second component according to the mass ratio, putting the second component into an intermediate frequency heating furnace, keeping the temperature within the range of 380-400 ℃, and continuously stirring for 2 hours to obtain the second component;

step 4, casting the second component into a section to be extruded, and cooling for later use;

step 5, putting the extruded section obtained in the step 4 into an extruder for extrusion, pressing the uniformly mixed first component into a second component through a pressurized and sealed injection barrel, wherein the pressing proportion is controlled at 10% through a flow regulating valve, and the pressing proportion is the mass proportion of the first component to the second component;

and 6, controlling the thickness of the wire diameter of the extruded product through a wire drawing die, and reaching the zinc-containing solder-free solder wire with the wire diameter of 1.5mm to obtain the sample to be tested in the embodiment 1.

Example 2:

a zinc-containing solder-free solder wire comprises 15% of a first component and 85% of a second component by mass percentage;

weighing a first component comprising 6Kg of 3 percent aqueous polyamide-imide resin solution and 9Kg of zinc-copper compound powder;

weighing 100Kg of second component electrolytic tin with the purity of 99.95%;

wherein the mass percentage of the water-based polyamide-imide resin in the water-based polyamide-imide resin water solution is 3 percent, the median particle size of the zinc-copper compound powder is 1.0 micron, and the zinc-copper compound powder at least comprises the following components: cu₅Zn₈、CuZn。

The preparation method comprises the following steps:

step 1, uniformly mixing a weighed aqueous polyamide-imide resin solution in the first component with zinc-copper compound powder, heating to 90-105 ℃, and keeping continuously stirring to obtain a first component;

step 2, pouring the uniformly mixed first component into a pressure injection barrel with heat preservation and stirring functions for later use;

step 3, weighing the electrolytic tin, the electrolytic bismuth and the electrolytic silver in the second component according to the mass ratio, putting the second component into an intermediate frequency heating furnace, keeping the temperature within the range of 380-400 ℃, and continuously stirring for 2 hours to obtain the second component;

step 4, casting the second component into a section to be extruded, and cooling for later use;

step 5, putting the extruded section obtained in the step 4 into an extruder for extrusion, pressing the uniformly mixed first component into a second component through a pressurized and sealed injection barrel, wherein the pressing proportion is controlled to be 15% through a flow regulating valve, and the pressing proportion is the mass proportion of the first component to the second component;

and 6, controlling the thickness of the wire diameter of the extruded product through a wire drawing die, and obtaining the zinc-containing solder-free solder wire with the wire diameter of 1.5mm, thereby obtaining the sample to be tested in the embodiment 2.

Example 3:

a zinc-containing solder-free solder wire comprises, by mass, 20% of a first component and 80% of a second component;

weighing a first component comprising 8Kg of 3 percent aqueous polyamide-imide resin solution and 12Kg of zinc-copper compound powder;

weighing 100Kg of second component electrolytic tin with the purity of 99.95%;

wherein the mass percentage of the water-based polyamide-imide resin in the water-based polyamide-imide resin water solution is 3 percent, the median particle size of the zinc-copper compound powder is 1.0 micron, and the zinc-copper compound powder at least comprises the following components: cu₅Zn₈、CuZn。

The preparation method comprises the following steps:

step 1, uniformly mixing a weighed aqueous polyamide-imide resin solution in the first component with zinc-copper compound powder, heating to 90-105 ℃, and keeping continuously stirring to obtain a first component;

step 2, pouring the uniformly mixed first component into a pressure injection barrel with heat preservation and stirring functions for later use;

step 3, weighing the electrolytic tin, the electrolytic bismuth and the electrolytic silver in the second component according to the mass ratio, putting the second component into an intermediate frequency heating furnace, keeping the temperature within the range of 380-400 ℃, and continuously stirring for 2 hours to obtain the second component;

step 4, casting the second component into a section to be extruded, and cooling for later use;

step 5, putting the extruded section obtained in the step 4 into an extruder for extrusion, pressing the uniformly mixed first component into a second component through a pressurized and sealed injection barrel, wherein the pressing proportion is controlled to be 20% through a flow regulating valve, and the pressing proportion is the mass proportion of the first component to the second component;

and 6, controlling the thickness of the wire diameter of the extruded product through a wire drawing die, and reaching the zinc-containing solder-free solder wire with the wire diameter of 1.5mm to obtain the sample to be tested in the embodiment 1.

The three samples of the above examples were compared with conventional solder wires of "1.5 mm wire diameter of tin-copper (sn0.7cu) and 2.0% rosin content" by soldering a brass wire having a wire diameter of 1.0mm to a T2 copper plate, and then observing and testing "residual state and dryness after soldering, solder spreading rate and soldering strength" and making a comparison, the test results are shown in table 1:

table 1: examples test data sheet

According to the experimental data, the solder wire without the soldering flux obtained by the technical scheme of the invention has the following advantages: firstly, no residue is left after welding, and the chalk powder is dry and does not stick to the chalk powder, thereby meeting the GB/T9491 standard; secondly, the spreading rate of the solder during welding reaches over 86 percent, meets the standard requirement and has little difference with the traditional rosin soldering wire; finally, in the pull-out test of the solder strength test, the overall strength was all stronger than the conventional solder wire.

The solder wire containing zinc and free of soldering flux obtained by the invention is suitable for assembling and welding various electronic components, can meet requirements of copper-based welding parts and welding parts with multiple alloy components such as nickel plating, silver plating, gold plating and the like, can produce solder wire finished products with the diameter of 0.8mm-3.5mm, and has wide application and strong applicability.

Therefore, the soldering tin wire without soldering flux obtained by the invention adopts the main component of the intermetallic compound formed by the soldered joint (IMC) in the traditional soldering as a part of the soldering tin wire alloy, and is fused with the soldering tin through a certain process, so that soldering flux-free soldering is realized, the residual after soldering is basically avoided, the soldering form (expansion rate) is better, the soldering strength is higher, and the soldering tin wire can completely meet and replace the traditional rosin soldering tin wire. The invention provides a novel material for the electronic welding industry, and the novel material has wider application scene and higher application reliability.

In a word, the invention has breakthrough of new technology on the basis of reaching the weldability and reliability of the traditional soldering wire. In the application process of a client, the original process is not required to be changed, and a better welding effect is achieved.

In the previous description, numerous specific details were set forth in order to provide a thorough understanding of the present invention. The foregoing description is only a preferred embodiment of the invention, which can be embodied in many different forms than described herein, and therefore the invention is not limited to the specific embodiments disclosed above. And that those skilled in the art may, using the methods and techniques disclosed above, make numerous possible variations and modifications to the disclosed embodiments, or modify equivalents thereof, without departing from the scope of the claimed embodiments. Any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the scope of the technical solution of the present invention.