Flux for Soldering

Abstract

The invention discloses a formula of scaling powder for soft soldering. Polybutylene with average molecular weight between 700 and 3000, rosin and alcohol esters surfactants are added, the weight ratio of the polybutylene in the scaling powder is smaller than 7%, or the additive amount of the polybutylene is smaller than 15% relative to the weight ratio of the rosin. The rosin is one or more of hydrogenated rosin, polymerized rosin and acid modified rosin. At present, lead-free soldering still has the problems that soldering tin is poor in diffusivity due to high-temperature oxidation, scaling powder slag is too much and hardened, and a circuit is poor in conduction testing. The scaling powder for the soft soldering has heat stability in the process of high-temperature reflow soldering, and solves the problems that the diffusivity is poor and the circuit conducting testing is poor.

Description

technical field [0001] The invention belongs to the flux on welding materials. Background technique [0002] The components of flux generally contain: rosin, anti-sagging agent, active agent, and solvent. The function of the flux is to remove the oxidized substances of the solder joints, increase the diffusion and solderability during soldering, and improve the yield rate of the in-circuit test after soldering, etc. [0003] Diffusion refers to the area covered by the solder during soldering. If the area covered is larger, it is less likely to cause false soldering during soldering. The circuit continuity test is to measure whether the solder joints of the circuit board are connected to the circuit, and the purpose is to test the quality of the circuit board. It uses the probe to contact the solder joint, and measures its resistance value with the probe. If there is no connection between the electronic part and the substrate, it is called false soldering. In this case, the...

AI Technical Summary

Problems solved by technology

[0011] Aiming at the problems that the current reflow temperature is increased due to the use of lead-free solder, the soldering temperature causes thermal cracking of the flux and high residue, resulting in poor diffusivity and poor circuit conduction test, etc., the inventor proposes a high-temperature flux formula composition , including polybutene, rosin and alcohol ester surfactants; the polybutene in the flux composition has an average molecular weight of 700 to 3000, and the amount added is greater than or equal to the weight ratio of rosin 1% and less than or equal to 15%, or the weight ratio in the flux is greater than zero and less than or equal to 7%; the rosin in the flux composition is selected from one or more of hydrogenated rosin, polymerized rosin and acid modified rosin The group of composition; Alcohol ester surfactant is selected from one or more decyl tetradecyl cetyl stearate (2-decyltetradecyl esters), hexyl decyl alcohol benzoate (Hexyldecyl Benzoate), hexyl Hexyldecyl ethylhexanoate, Hexyldecyl hexyldecanoate, Hexyldecyl isostearate, 2-Hexyldecyl laurate, 2-Hexyldecyl oleate, 2-Hexyldecyl palmitate, Hexyldecyl stearate, Hexyldecyl myristoyl aminopropionate ( Hexyldecyl myristoyl methylaminopropionate), Isohexadecyl docosanoate, 2-hexyldecyl ester, Isocetyl ethylhexanoate, Isocetyl isocetyl Isocetyl isodecanoate, Isohexadecyl isooctadecanoate, Isohexadecyl laurate, Isocetyl myristate, Isocetyl Alcohol palmitate (isohexadecyl ester), isocetyl stearate (Isocetyl stearate), isocetyl salicylate (Isocetyl salicylate) and isocetyl alcohol (12-stearyloxystearate ) ester (Isohexadecyl 12-((1-oxooctadecyl)oxy)octadecano ate); the above-mentioned flux can make the solder expand well, the flux residue on the solder joint becomes less, and the residue is not easy to harden

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