Panasonic ASCT1F46E Examples of SMT Applications, Cautions for installation 1. Paste Soldering

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3. Examples of SMT Applications

1.Infrared Reflow Soldering (IRS)

2.Vapor Phase Soldering (VPS)

3.Belt conveyer reflow oven

4.Double Wave Soldering (DWS)

5.Other Technologies

IRS is the most popular reflow soldering technology now available for surface mounting. It uses a sheath heater or infrared lamp as its heat source. PC board assemblies are continuously soldered as they are transferred through a tunnel furnace comprised of a preheating, heating, and cooling-stages.

With VPS technology, PCB assemblies are carried through a special inactive solvent, such as Fluorinert FC-70, that has been heated to a vapor state. As the saturated vapor condenses on the PC board surface, the resulting evaporation heat provides the energy for reflow soldering.

As PCB assemblies are transferred on a thin, heat-resistant belt conveyer, they are soldered by the heat from hotplates placed beneath the conveyer belt.

After components are glued to the PC board surface, the board assembly is transferred through a molten solder fountain (with the component side facing down). Then, the components are soldered to the board.

Other reflow soldering technologies include those of utilizing lasers, hot air, and pulse heaters.

2.Cautions for installation

1.Paste Soldering

•Mounting pads on PC boards must be designed to absorb placement errors while taking account of solderability and insulation. Refer to the suggested mounting pad layout in the application data for the required relay product.

•Paste solder may be applied on the board with screen printing or dispenser techniques. For either method, the paste solder must be coated to appropriate thickness and shapes to achieve good solder wetting and adequate insulation.

2. Relay mounting

•For small, lightweight components such as chip components, a self-alignment effect can be expected if small placement errors exist. However, this effect is not as expected for electro-mechanical components such as relays, and they require precise positioning on their soldering pads.

•If SMT relays are subjected to excessive mechanical stress from the placement machine's pickup head and damaged inside, their performance cannot be guaranteed.

•Our SMT relays are supplied in tube packaging compatible with automatic placement processes. We also offer tape packaging at customer request..