Soldering flux for lead-free solder and preparation method of soldering flux

A lead-free solder and flux technology, used in welding equipment, welding/cutting media/materials, welding media, etc., can solve the problems of decreased surface insulation resistivity, more residues on printed component boards, and high ionic pollution. Achieve the effect of improving insulation stability, low cost and reducing electromigration

Active Publication Date: 2013-09-11
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In consideration of the welding effect, some fluxes use highly corrosive substances with high solid content as active components, resulting in ...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Organic acids: succinic acid 1.2g adipic acid 1.2g

[0025] Organic amine: triethanolamine 0.4g

[0026] Surfactant: OP-10 emulsifier 0.1g

[0027] Film-forming agent: polyethylene glycol 2000 0.5g

[0028] Co-solvent: ethylene glycol 20g glycerol 10g

[0029] Corrosion inhibitor: benzotriazole 0.1g

[0030] Deionized water 66.5g

[0031] Preparation method: Dissolve organic acid, organic amine and surfactant in part of deionized water at a relatively low temperature (about 20-35°C), stir evenly to obtain an intermediate product, and set aside. Then add the co-solvent and the remaining amount of deionized water into another reaction kettle, add the film-forming agent while stirring, and heat to 40-60°C. After the film-forming agent is completely dissolved, stop heating, cool to room temperature, and stir successively Add the intermediate product and the corrosion inhibitor, mix the solution evenly, let it sit and filter to obtain the flux of the present invention. ...

Embodiment 2

[0033] Organic Acids: Succinic Acid 1.2g Adipic Acid 1.2g

[0034] Organic amine: triethylamine 0.5g

[0035] Surfactant: OP-10 0.1g

[0036] Film-forming agent: polyethylene glycol 4000 0.4g

[0037] Co-solvent: ethylene glycol 16g glycerol 8g

[0038] Corrosion inhibitor: benzotriazole 0.2g

[0039] Deionized water 72.4g

[0040] Preparation method: with embodiment 1.

Embodiment 3

[0042] Organic Acids: Succinic Acid 1.0g Adipic Acid 1.0g

[0043] Organic amine: triethanolamine 0.4g

[0044] Surfactant: TX-10 0.15g Sodium dodecylsulfonate 0.15g

[0045] Film-forming agent: polyethylene glycol 2000 0.8g

[0046] Co-solvent: tetrahydrofurfuryl alcohol 20g glycerol 10g

[0047] Corrosion inhibitor: methyl benzotriazole 0.1g

[0048] Deionized water 66.4g

[0049] Preparation method: with embodiment 1.

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Abstract

The invention relates to soldering flux for lead-free solder and a preparation method of the soldering flux. The soldering flux comprises, by mass, 2.0-4.0% of activating agent, 0.05-0.5% of surfactant, 0.4-1.0% of film-forming agent, 18-30% of cosolvent, 0.1-0.4% of corrosion inhibitor and the balance deionized water. The soldering flux is free of rosin and less than 3% in solid content, so that solid residual quantity is less during soldering, ionic contamination degree is low, and cleaning is avoided after soldering. By using the deionized water as solvent, the water-soluble no-clean soldering flux is colorless, transparent, free of pungent smell, easy in raw material getting approach and low in cost. Activating components in the soldering flux are halogen-free, so that insulativity of a soldered circuit board is improved; by the aid of the film-forming agent, a dense protecting film is formed on the surface of the circuit board after the film-forming agent is subjected to a soldering procedure, and accordingly, electromigration of soldered residues is lowered, and insulation stability of the circuit board is improved effectively; and harm caused when organic soldering flux is used for soldering can be reduced, and the soldering flux meets the environment-friendly requirements.

Description

technical field [0001] The invention belongs to the technical field of microelectronic soldering materials, and relates to a flux, in particular to a flux for lead-free solder and a preparation method thereof. Background technique [0002] Traditional electronic products use lead-tin solder as the soldering material, which has a low melting point (183°C) and good solderability. However, with the promulgation and implementation of the ban on lead in electronic information products, the use of lead-tin solder is restricted, and lead-free solder gradually replaces lead-tin solder as an important connecting material in the electronics industry. However, due to the high melting point of lead-free solder, it is easy to oxidize during use and has poor wettability. Traditional fluxes can no longer meet the soldering requirements of lead-free solder. [0003] At present, most of the fluxes widely used are organic solvent-based fluxes. The active components of this type of flux must ...

Claims

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Application Information

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IPC IPC(8): B23K35/363
Inventor 杨鹰秦春阳李海普
Owner CENT SOUTH UNIV
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