Water-soluble soldering flux dedicated for lead-free solder

A lead-free solder, water-soluble technology, applied in the direction of welding/cutting medium/material, welding medium, welding equipment, etc., can solve the problems of circuit board insulation decline, difficulty in achieving reliability, short circuit of solder joints, etc., and achieve insulation resistance High, excellent flux performance, strong wetting effect

Inactive Publication Date: 2006-09-27
BEIJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If you use no-clean flux soldering, it is difficult to meet the reliability requirements, because the printed board is exempt from cleaning after soldering, and the residue on the board surface may become some electrolytes in the case of long-term humidity or heating. Causes the insulation of the circuit board to drop, and even short-circuits the solder joints

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Boric acid 6.2

[0029] Succinic acid 0.1

[0030] Glutaric acid 0.1

[0031]OP emulsifier 0.1

[0032] Glycerol 8.0

[0033] Glyceryl monostearate 0.3

[0034] Benzotriazole 0.1

[0035] Deionized water 85.1

[0036] Preparation method:

[0037] Add co-solvent and part of deionized water into the reaction kettle with agitator first, add film-forming agent under stirring, add the remaining amount of deionized water, activator and surfactant after dissolving, then add corrosion inhibitor, stir until The solid matter is completely dissolved, the materials are mixed evenly, and the filtrate is retained after static filtration to obtain the flux of the present invention.

[0038] After testing, the activation temperature range of the water-soluble flux for lead-free solder in this embodiment is 160°C-245°C, the halogen content is 11 Ω, the expansion rate is 82.1%, and the dryness, foamability, and copper plate corrosion performance are all qualified. No pungent odor...

Embodiment 2

[0040] Boric acid 6.2

[0041] Sorbic acid 0.1

[0042] Adipic acid 0.1

[0043] TX-10 0.2

[0044] Glycerol 10.0

[0045] Diethylene glycol 2.0

[0046] Ethyl benzoate 0.3

[0047] Benzotriazole 0.1

[0048] Deionized water 81.0

[0049] After testing, the activation temperature range of the water-soluble flux for lead-free solder of the present invention is 170°C-245°C, the halogen content is 11 Ω, the expansion rate is 81.8%, and the dryness, foamability, and copper plate corrosion performance are all qualified. No pungent odor is emitted during welding.

Embodiment 3

[0051] Boric acid 4.8

[0052] 6-oxoheptanoic acid 0.2

[0053] L-Arginine 0.1

[0054] OP emulsifier 0.3

[0055] FSO 0.1

[0056] Glycerol 8.0

[0057] Diethylene glycol-diethyl ether 2.0

[0058] Ethyl benzoate 0.3

[0059] Triethylamine 0.1

[0060] Deionized water 85.1

[0061] After testing, the activation temperature range of the water-soluble flux for lead-free solder of the present invention is 150°C-245°C, the halogen content is 11 Ω, the expansion rate is 80.9%, and the dryness, foamability, and copper plate corrosion performance are all qualified. No pungent odor is emitted during welding.

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PUM

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Abstract

The water soluble soldering flux specially for lead-free soldering material consists of boric acid and organic acid activator 5.0-10.0 wt%, non-ionic surfactant or cationic surfactant 0.1-1.0 wt%, co-solvent 8.0-20.0 wt%, filming agent 0.1-1.0 wt%, corrosion retardant 0.1-0.5 wt%, except deionized water. The compounding process includes the following steps: mixing co-solvent and partial deionized water, adding filming agent under stirring, adding the rest deionized water, activator and surfactant after dissolving, adding corrosion retardant while stirring to dissolve, stilling, and filtering to obtain the filtrate as the soldering flux. The water soluble soldering flux has excellent soldering assisting performance on lead-free soldering material, environment friendship and other advantages.

Description

technical field [0001] The invention relates to a flux, in particular to a water-soluble flux specially adapted to lead-free solder. Background technique [0002] Due to the requirements of global environmental protection regulations and the development of the electronic industry, lead-free electronic products are an inevitable trend. At present, the lead-free solders that are more researched and initially commercialized in the world are Sn-Ag and Sn-Ag-Cu eutectic alloys. However, in the process of research and use, it was found that compared with traditional Sn-Pb solder, lead-free solder has poor wettability, is easy to oxidize, and has a high melting point. The increase of the melting point means that the soldering temperature must be increased. On the one hand, it will cause damage to the components on the board surface. On the other hand, it will inevitably increase the volatilization of the active agent in the flux, which is likely to cause the failure of the flux pe...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23K35/36B23K35/38
Inventor 雷永平徐冬霞夏志东史耀武郭福张冰冰王友山
Owner BEIJING UNIV OF TECH
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