Nano leadless soldering paste

A technology of lead-free solder paste and lead-free solder, applied in the direction of welding medium, welding equipment, welding/cutting medium/material, etc., can solve the problems of lead poisoning and achieve the effect of lowering the temperature

Inactive Publication Date: 2009-02-11
SHANGHAI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, lead is a toxic metal, and the human body

Method used

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  • Nano leadless soldering paste
  • Nano leadless soldering paste

Examples

Experimental program
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Effect test

Embodiment 1

[0016] The nano-lead-free solder paste of the present embodiment is made up of Sn-Ag-Cu nano-lead-free solder powder and rosin no-cleaning flux, with a total weight of 10g, and its composition is calculated by mass fraction as:

[0017] Nano lead-free solder powder 90 parts

[0018] Flux 10 parts

[0019] The mass percent of each element in the nanometer lead-free solder powder is:

[0020] Ag 4.0%;

[0021] Cu 0.5%;

[0022] Sn margin.

[0023] a. The nanopowder stored in the paraffin liquid is separated, and chloroform is selected as the separation solvent.

[0024] b. Mix the separated nano-powder and rosin no-cleaning flux evenly to make solder paste, and its melting point is lowered as shown in figure 1 .

Embodiment 2

[0026] The nano-lead-free solder paste of the present embodiment is made up of Sn-Co-Cu nano-lead-free solder powder and rosin no-clean flux, with a total weight of 10g, and its composition is calculated by weight fraction:

[0027] Nano lead-free solder powder 90 parts

[0028] Flux 10 parts

[0029] The mass percent of each element in the nanometer lead-free solder powder is:

[0030] Cu 0.7%;

[0031] Co 0.4%

[0032] Sn margin.

[0033] The nanometer powder stored in the paraffin liquid is separated, and chloroform is selected as the separation solvent. Mix the separated nano-powder with rosin no-cleaning flux evenly to make a solder paste, and its melting point is lowered as shown in figure 2 . Example 3

Embodiment 3

[0034] The nano-lead-free solder paste of the present embodiment is made up of Sn-Bi nano-lead-free solder powder and rosin no-clean flux, with a total weight of 10g, and its composition is calculated by weight fraction:

[0035] Nano lead-free solder powder 90 parts

[0036] Flux 10 parts

[0037] The mass percent of each element in the nanometer lead-free solder powder is:

[0038] Bi 57%

[0039] Sn margin.

[0040] The nanometer powder stored in the paraffin liquid is separated, and chloroform is selected as the separation solvent. The separated nano-powder is evenly mixed with rosin no-cleaning flux to prepare a solder paste.

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Abstract

The invention relates to nano lead-free soldering paste used for electronic element welding and surface packaging. The nano lead-free soldering paste consists of nano lead-free solder powder and soldering flux, and according to the mass percent, the nano lead-free soldering paste contains the following components: 85 to 94 percent of nano lead-free solder powder and 6 to 15 percent of soldering flux, wherein, the nano lead-free solder powder can be Sn-Ag, Sn-Ag-Cu, Sn-Bi, Sn-Zn, Sn-Zn-Bi, Sn-Co-Cu, Sn-Cu, Sn-In, or Sn-Sb. The nano lead-free soldering paste has all the basic properties of common lead-free soldering paste, and the melting point thereof is reduced. Compared with the common lead-free soldering paste, the nano lead-free soldering paste does not contain the toxic element of lead, thereby being applicable to the electronic packaging technology in the microelectronic industry.

Description

technical field [0001] The invention relates to a lead-free solder paste used for soldering and surface packaging of electronic components, in particular to a nano-lead-free solder paste. Background technique [0002] Soldering is a very old and practical technology, mainly based on tin-lead alloy system, the eutectic temperature of this tin-lead alloy is 183 ℃, it has good physical properties, mechanical properties and metallurgical properties, so it is widely used in the electronics industry. The use of tin-lead eutectic solder alloy has a long history, and a lot of practical application experience has been accumulated in production. At the same time, the cost of raw materials is low and the resources are extensive. However, lead is a toxic metal, and low doses of lead absorbed by the human body can cause lead poisoning. With the increase of electronic waste, a large number of waste electronic devices are discarded or buried, and the toxic component lead in electronic wa...

Claims

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Application Information

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IPC IPC(8): B23K35/22
Inventor 刘建影张利利陈思张燕翟启杰高玉来
Owner SHANGHAI UNIV
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