Solder paste or solder cream is simply a suspension of fine solder particles in a flux vehicle. In electronics industry, solder paste is used in surface mount technology (SMT) to solder SMD Electronic Components on to the printed circuit board.
The composition of the particles can be tailored to produce a paste of the desired melting range. Additional metals can be added to change paste compositions for specialized applications. Particle size and shape, metal content and flux type can be varied to produce pastes to varying viscosity.
Lead-Free Solder Paste
With the implementation of RoHS (Restriction of Hazardous Substances) in the Electronics Industry by the European Union and Many other countries, most electronic companies are shifting to Lead Free. Lead Free solder wire and solder paste are manufactured using different composition and ratio. But the most popular and widely used composition and ratio is SAC (Tin Silver Copper) in the Ratio 96.5% Tin + 3.0% Silver and 0.5% Copper.
Lead-free solder has higher melting point than the conventional 63/37 or 60/40 Tin-Lead Solder. Also the solder joints are not as shiny as tin-lead solder.
Solder Paste Screen Printer
Some of the major features to consider when selecting screen printer for solder cream are the maximum size of the printed circuit board that can be handled, controls of accurate screen alignment and repeatability of print, and the board hold-down mechanism. Considerable progress has been solder paste dispenser, screening and stenciling for pastes on substrates. Each method of dispensing solder cream has its own pros and cons but the most widely used method is stenciling for both rework and large scale production. Vastex is a well-known manufacturer and supplier of screen printing equipment.
NeoDen Semi-auto Solder Printer YS350
Stencils for Solder Paste Application
There are three main ways of making stencils for solder paste:
Chemical etching
Laser cutting
Electroforming
Chemical etching is the oldest, most widely used, and least expensive option. Laser cutting and electroforming, especially the latter, find appeal in applications where precision is paramount. In addition to the type of stencil, the type of squeegee blade is very important. Metal blade squeegees are widely used because they require less maintenance than rubber squeegees.
NeoDen provide a full smt assembly line solutions, including SMT reflow oven, wave soldering machine, pick and place machine, solder paste printer, PCB loader, PCB unloader, chip mounter, SMT AOI machine, SMT SPI machine, SMT X-Ray machine, SMT assembly line equipment, PCB production Equipment smt spare parts etc any kind SMT machines you may need, please contact us for more information:
Hangzhou NeoDen Technology Co.,Ltd
Add: Building 3,Diaoyu Industrial and Technology Park,No.8-2,Keji Avenue, Yuhang District, Hangzhou，China
Contact us: Steven Xiao
E-mail:steven@neodentech.com
Phone:86-18167133317
Skpe：toner_cartridge