Needle cylinder injection type leadless solder paste for heat radiator welding

Abstract

The invention discloses a needle cylinder injection-typed lead-free solder paste used for the welding of radiators; the lead-free solder paste contains a tin-bismuth-rare earth lead-free solder mixed with a soldering flux. The soldering flux comprises 40 to 45 percent of resin (such as hydrogenation resin glycerol and alkyd resin), 10 to 15 percent of active agent (such as alkyl poly-glycosides and monoethanolamide sulfosuccinate), 2.1 to 3.1 percent of thixotropic agent (such as amide modified hydrogenated castor oil and Ethylene bis stearamide stearic amide), 0.8 to 1.2 percent of special additive (such as release agent, antioxidant and resist), and residual quantity of solvent (such as glycol dipropionate ether acetate and 1,3-propanediol). The needle cylinder injection typed lead-free solder paste of the invention has low welding temperature, comparatively low viscosity, better rheological property under the action of the pressure, and better anti-collapse performance after the solder paste is coated, and is especially applicable to the welding of the radiators, and is beneficial to precisely controlling the dosage of the welding paste and saving the cost.

Description

technical field

[0001] The invention relates to a lead-free solder paste for soldering electronic products, which is especially suitable for injecting and dripping the solder paste on radiators. Background technique

[0002] Heat dissipation has become a major stumbling block restricting the rapid development of chip performance, and is a life-threatening issue for the entire information industry and even the global economy. Reliable radiator welding is the guarantee of good cooling effect of the chip. As people pay more attention to environmental protection and their own health, it is imperative to make solder paste lead-free. Due to the poor thermal shock resistance of the heat sink used for chip heat dissipation, it is necessary to choose a solder paste with a lower soldering temperature during soldering. The existing lead-free solder pastes include tin-silver, tin-copper and other series, and the soldering temperature is mostly above 200°C, which cannot meet the requir...