Is lead-free solder paste toxic if it has not been reflow soldered?I believe many people know that this product is widely used in welding. Also, many people are asking whether it is harmful to the body when working in a processing factory. Among them, this reflow soldering process is the most important and also a very crucial step. This is inevitable. In this regard, if the operation is not proper, it will cause certain impacts. Therefore, everyone should pay attention to getting familiar with this aspect. Now, JJY solder Paste Manufacturer will explain it to you:
1Firstly, the solvent used to achieve the required viscosity and screen printing performance begins to evaporate, and the temperature rise must be slow(Approximately per second3°C)To limit boiling and splashing, prevent the formation of small tin beads. Also, some components are relatively sensitive to internal stress. If the external temperature of the component rises too fast, it will cause fracture.
2When the temperature continues to rise, the solder particles first melt individually and start the "lamp-like" process of liquefaction and surface tin absorption. In this way, it covers all possible surfaces and begins to form solder joints.
3When the flux becomes active, the chemical cleaning operation begins. Both water-soluble flux and no-clean flux will undergo the same cleaning operation, but at slightly different temperatures. Remove metal oxides and certain contaminants from the metal and solder particles that are about to be bonded. Good solder joints in metallurgy require a "clean" surface.
Ii. Technical Requirements for Lead-free Solder Paste Reflow Soldering
1It is important to have sufficient slow heating to safely evaporate the solvent, prevent the formation of solder beads and limit the internal stress of the component caused by temperature expansion, which may lead to reliability issues of cracking.
2The active stage of the flux must have an appropriate time and temperature, and the cleaning stage is allowed to be completed when the solder particles just start to melt.
3The stage of solder melting in the time-temperature curve is the most crucial. It is essential to ensure that the solder particles are fully melted and liquefied to form a metallurgical weld. The evaporation of the remaining solvent and flux residue forms the surface of the solder joint. If this stage is too hot or lasts too long, it may affect the components andPCBCause harm.
4The setting of the lead-free solder paste reflux temperature curve is best based on the data provided by the lead-free solder paste supplier. At the same time, the principle of internal temperature stress changes of the component should be grasped, that is, the heating temperature rise rate should be less than per second3°CThe cooling temperature drop rate is less than5°C.
Nowadays,Lead-free solder pasteIt has already become part of many industrial and hardware auxiliary works, each oneLEDManufacturers, mobile phone manufacturers, smartwatches manufacturers, medical electronic device manufacturers, digital camera manufacturers, etc. all need to be involvedSMTWe need lead-free and halogen-free solder paste to make our electronic smart life more stable and convenient.
SHENZHEN JIAJINYUAN INDUSTRIAL TECHNOLOGY CO., LTD.
Tel：+86 0755 88366766
Phone：+86 18938660310
Email：sales@jjyhanxi.com
Address：13/F,12/F, Building No. B,Qinghu Technology Park,Qingxiang Rd.,Qinghu Community, Longhua Subdistrict,Longhua District,Shenzhen City,GUANGDONG Province,P.R.C.(518027)
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