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CN-121972859-A - High-reliability multi-element alloy electronic solder and preparation method thereof

CN121972859ACN 121972859 ACN121972859 ACN 121972859ACN-121972859-A

Abstract

The invention discloses high-reliability multi-element alloy electronic solder and a preparation method thereof, and relates to the technical field of electronic welding materials. The solder comprises, by weight, 2.0-3.5 parts of Ag, 0.3-1 part of Cu, 0.5-2 parts of Bi, 0.1-1.5 parts of Sb, 0.01-0.1 part of trace elements and 91.9-97.09 parts of Sn, wherein the trace elements are 1-2 kinds of Ni, ge, in, fe, au. According to the invention, by adding trace elements of specific types and proportions, the atomic diffusion channel characteristics of the interface between the solder and the substrate are effectively regulated, and an optimized microstructure is formed at the interface, so that good interface bonding strength is ensured, the thickness of an interface reaction layer is controlled, and the thermal cycle fatigue life and long-term reliability of a welding spot are remarkably improved. The invention also provides a preparation method of the solder, which has simple process and is easy for industrial production.

Inventors

  • PENG JINGHONG
  • PENG YONGJUN

Assignees

  • 广州市确信电子焊料有限公司

Dates

Publication Date
20260505
Application Date
20260311

Claims (10)

  1. 1. The high-reliability multi-element alloy electronic solder is characterized by comprising the following components in parts by weight: 2.0-3.5 parts of Ag; 0.3-1 part of Cu; 0.5-2 parts of Bi; 0.1-1.5 parts of Sb; 91.9-97.09 parts of Sn; 0.01-0.1 part of microelements, wherein the microelements are 1-2 kinds selected from Ni, ge, in, fe, au.
  2. 2. The high reliability multi-alloy electronic solder of claim 1, wherein the trace elements are a combination of Ni and Ge.
  3. 3. The high-reliability multi-element alloy electronic solder according to claim 2, wherein the content of Ni is 0.01 to 0.05 parts and the content of Ge is 0.01 to 0.05 parts.
  4. 4. The high reliability multi-alloy electronic solder of claim 1, wherein the trace elements are a combination of Ni and In.
  5. 5. The high-reliability multi-element alloy electronic solder according to claim 1, wherein the content of Ag is 2.5-3.0 parts, the content of Cu is 0.5-0.8 parts, the content of Bi is 0.8-1.2 parts, and the content of Sb is 0.3-0.5 parts.
  6. 6. A method for preparing the high-reliability multi-element alloy electronic solder according to any one of claims 1 to 5, comprising the following steps: (1) Weighing the raw materials of all the components according to the proportion; (2) Heating Sn matrix metal to 400-450 ℃ in a vacuum induction melting furnace to melt; (3) Sequentially adding Ag, cu, bi, sb, uniformly stirring, and keeping the temperature at 350-400 ℃; (4) Adding trace elements, uniformly stirring, and keeping the temperature at 300-350 ℃; (5) Refining and degassing, and casting and forming to obtain a solder alloy ingot.
  7. 7. The method according to claim 6, wherein the heating temperature in the step (2) is 420 ℃, the holding temperature in the step (3) is 380 ℃, and the holding temperature in the step (4) is 320 ℃.
  8. 8. The method of manufacturing according to claim 6, further comprising the step of extruding and drawing the solder alloy ingot into solder wires.
  9. 9. Use of the high-reliability multi-alloy electronic solder according to any one of claims 1 to 5 in soldering electronic components.
  10. 10. The use according to claim 9, wherein the electronic component is an electronic component in an aerospace, automotive electronic or communication device.

Description

High-reliability multi-element alloy electronic solder and preparation method thereof Technical Field The invention relates to the technical field of electronic welding materials, in particular to a high-reliability multi-element alloy electronic solder and a preparation method thereof. Background With the rapid development of miniaturization, light weight and high performance of electronic devices, electronic packaging technology has placed more stringent demands on the reliability of solder materials. Traditional tin-lead solders have been gradually replaced by lead-free solders because of the toxic substance lead. Among the lead-free solder systems, tin-silver-copper based alloys are the most widely used mainstream lead-free solder at present due to their excellent mechanical properties and soldering process properties. However, the prior Sn-Ag-Cu solder still has obvious performance bottleneck in practical application. Particularly, when molten solder contacts with a copper substrate during soldering, atomic diffusion speed at an interface is high, so that an interface reaction layer grows too fast, and a thick brittle intermetallic compound layer is easy to generate. Along with the extension of the service time of the electronic product, the brittle layer is very easy to become a crack source under the action of thermal cycle stress, so that a welding spot is invalid, and the long-term reliability of the electronic equipment is seriously affected. In addition, under extreme environments such as high temperature, high humidity, the interface stability of the existing solder is poor, the atomic diffusion behavior is difficult to control, and the degradation of the performance of the welding spot is further aggravated. In order to improve the solder properties, researchers have attempted to modify the base alloy by adding microelements such as Bi, sb, ni, etc. However, the prior art is often focused on the addition or simple mixing of single elements, and lacks deep research on the synergistic action mechanism of microelements and matrix alloy, and particularly the regulation mechanism of microelements on the interface atomic diffusion channel characteristics is not clear. The prior modified solder has limited effect in inhibiting the growth of an interface reaction layer and prolonging the service life of thermal cycle, and is difficult to meet the application requirements of the fields of high reliability such as aerospace, automobile electronics and the like. Disclosure of Invention The application provides a high-reliability multi-element alloy electronic solder and a preparation method thereof, aiming at solving the technical problems of the existing electronic solder that the interface reaction layer grows too fast and the thermal cycle reliability is poor. The application provides a high-reliability multi-element alloy electronic solder, which comprises the following components in parts by weight: 2.0-3.5 parts of Ag; 0.3-1 part of Cu; 0.5-2 parts of Bi; 0.1-1.5 parts of Sb; 91.9-97.09 parts of Sn; 0.01-0.1 part of microelements, wherein the microelements are 1-2 kinds selected from Ni, ge, in, fe, au. According to the invention, a multi-component synergistic enhanced alloy system is constructed by introducing Bi and Sb elements In a specific proportion into a Sn-Ag-Cu matrix and compounding trace elements such as Ni, ge, in and the like. Ag and Cu are used as basic components to form Ag3Sn and Cu6Sn5 intermetallic compounds to provide basic strength for the solder, bi element is solid-dissolved in Sn matrix to realize solid-solution strengthening effect, and meanwhile, the melting point of the alloy can be reduced to improve wettability, and Sb element forms tiny SnSb phase through solid-solution strengthening to obviously improve creep resistance of the solder. More importantly, the invention realizes the accurate regulation and control of the diffusion behavior of atoms at the interface of the welding flux and the base material by adding trace Ni, ge and other elements. The Ni element tends to be enriched at the solder/substrate interface and participate in the interface reaction to form dispersed intermetallic compound particles which can be pinned to the grain boundary to block the excessive diffusion of Cu atoms and Sn atoms, thereby effectively inhibiting the excessive growth of the interface reaction layer. The Ge element has the effects of refining grains and improving oxidation resistance, and can improve the surface tension of molten solder and further improve wettability. The two cooperate to construct a nano diffusion barrier layer at the interface, so that good interface bonding strength is ensured, and excessively thick growth of a brittle interface layer is avoided, thereby remarkably prolonging the thermal cycle fatigue life of a welding spot. Further, the microelements are a combination of Ni and Ge. Specifically, the content of Ni is 0.01-0.05 part, and the content of Ge is 0.01-