SMT (surface mount technology) may be widely used in most PCB (printed circuit board) assembly processes these days, but many boards will still require through-hole technology. However, conventional wave soldering may not be able to make through-hole pins adhere well to the board. Selective soldering uses high solder temperatures where solder must remain in contact with the board much longer than the time required in traditional wave soldering. Due to the smaller molten solder mass touching the board, and heat quickly dissipating from the area of contact with the rest of the PCB, longer contact time is required. In such cases, selective soldering is used along with specially formulated liquid soldering flux that can stand up to high solder temperatures and lengthy contact times.
Selective soldering is the cost-effective and precise means to solder through-hole components. It eliminates the need to solder by hand, which can be costly, time consuming and can result in several errors. With selective soldering, delicate and specific areas can be easily and accurately targeted, repeatability can be enhanced, defects can be lessened and output can be increased. There are different ways to execute selective soldering, but it is typically conducted by machine, which is programmable. The process requires the use of an appropriate liquid solder flux. Caution must be observed to prevent contamination caused by flux residue, which can spread to other areas of the board.
Liquid solder fluxes for selective soldering are supplied in different formulations, such as lead-free, low Ag, water soluble, and with the conventional Sn-PB alloy formulation. Choosing the right flux is essential for increased yield and throughput. Manufacturers of liquid solder fluxes can provide an appropriate solder alloy to suit every assembly type, such as simple and single-sided FR2 or CEM-1 laminates, OSP pad finishes, dual-sided FR-4 with PHTs, and less than 2.4mm thick with less than 12 inner copper layers and high heat capacity parts.
Selective soldering is the cost-effective and precise means to solder through-hole components. It eliminates the need to solder by hand, which can be costly, time consuming and can result in several errors. With selective soldering, delicate and specific areas can be easily and accurately targeted, repeatability can be enhanced, defects can be lessened and output can be increased. There are different ways to execute selective soldering, but it is typically conducted by machine, which is programmable. The process requires the use of an appropriate liquid solder flux. Caution must be observed to prevent contamination caused by flux residue, which can spread to other areas of the board.
Liquid solder fluxes for selective soldering are supplied in different formulations, such as lead-free, low Ag, water soluble, and with the conventional Sn-PB alloy formulation. Choosing the right flux is essential for increased yield and throughput. Manufacturers of liquid solder fluxes can provide an appropriate solder alloy to suit every assembly type, such as simple and single-sided FR2 or CEM-1 laminates, OSP pad finishes, dual-sided FR-4 with PHTs, and less than 2.4mm thick with less than 12 inner copper layers and high heat capacity parts.
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