Panasonic ASCT1F46E - Manual (Page 17)

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3. Examples of SMT Applications
1. Infrared Reflow Soldering
(IRS)
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.
2. Vapor Phase Soldering (VPS)
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.
3. Belt conveyer reflow oven
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.
4. Double Wave Soldering (DWS)
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.
5. Other Technologies
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..