Yuqori haroratli lehim pastasi va past haroratli lehim pastasi o'rtasidagi farq

Umuman olganda, yuqori haroratli lehim pastasi odatda qalay, kumush, mis va boshqa metall elementlardan iborat bo'lib, an'anaviy erish nuqtasi 217 darajadan yuqori. LED chipini qayta ishlashda yuqori haroratli qo'rg'oshin-bo'sh lehim pastasining ishonchliligi nisbatan yuqori va uni eritish va yorilish oson emas.

An'anaviy past haroratli lehim pastasining erish nuqtasi-138 daraja. Yamoqning tarkibiy qismlari 200 daraja yoki undan yuqori haroratga bardosh bera olmasa va yamoqni qayta oqimlash jarayoni talab etilsa, payvandlash jarayoni uchun past haroratli lehim pastasidan foydalanish kerak. U asl va tenglikni yuqori-haroratli qayta lehimlanishiga bardosh bera olmaydi. Uning qotishma tarkibi qalay vismut qotishmasidan iborat. Past haroratli lehim pastasini qayta oqim bilan lehimlashning eng yuqori harorati 170-200 daraja.

Yuqori haroratli lehim pastasi:

1.U yaxshi chop etish va qalay tushirishga ega, shuningdek, 0,3 mm gacha bo'lgan oraliqli prokladkalar uchun aniq chop etishni yakunlashi mumkin.

2. Several hours after the solder paste is printed, it still maintains its original shape without collapse, and the patch elements will not be offset.

3. It can meet the requirements of different grades of welding equipment, does not need to complete welding in nitrogen filled environment, and can still show good welding performance in a wide range of reflow furnace temperature.

4. The residue of high-temperature solder paste after welding is very little, colorless, has high insulation resistance, will not corrode PCB, and can meet the requirements of no cleaning.

5. It can be used in paste in hole process.

Past haroratli lehim pastasi:

1. Excellent printability, eliminating omission, depression and fast knot in the printing process.

2. Good wettability, bright, uniform and full solder joints.

3. Suitable for wide process and fast printing.

4. Fully comply with ROHS standards.

       High temperature solder paste is suitable for high temperature welding components and PCB; Low temperature solder paste is suitable for components or PCBs that cannot withstand high temperature welding, such as heatsink module soldering, led soldering, high frequency welding and so on.

     The alloy composition of high temperature solder paste is generally tin, silver and copper (SAC for short); The alloy composition of low-temperature solder paste is generally Sn Bi series, including various alloy components such as SnBi, snbiag and snbicu. Sn42bi58 is a eutectic alloy with a melting point of 138 degree , and other alloy components have no eutectic point and different melting points.