ZED-F9P-Integration Manual
UBX-18010802 - R01
6 Product handling Page 54 of 64
Objective Specification - Confidential
6 Product handling
6.1 Soldering
Soldering Paste
Use of “No Clean” soldering paste is highly recommended, as it does not require cleaning after the
soldering process has taken place. The paste listed in the example below meets these criteria.
• Soldering Paste: OM338 SAC405 / Nr.143714 (Cookson Electronics)
• Alloy specification: Sn 95.5/ Ag 4/ Cu 0.5 (95.5% Tin/ 4% Silver/ 0.5% Copper)
• Melting Temperature: 217 °C
• Stencil Thickness: The exact geometry, distances, stencil thicknesses and solder paste
volumes must be adapted to the specific production processes (e.g. soldering) of the
customer.
Reflow soldering
A convection type-soldering oven is highly recommended over the infrared type radiation oven.
Convection heated ovens allow precise control of the temperature, and all parts will heat up evenly,
regardless of material properties, thickness of components and surface color.
As a reference, see the “IPC-7530 Guidelines for temperature profiling for mass soldering (reflow
and wave) processes”, published in 2001.
Preheat phase
During the initial heating of component leads and balls, residual humidity will be dried out. Note that
this preheat phase will not replace prior baking procedures.
• Temperature rise rate: max. 3 °C/s. If the temperature rise is too rapid in the preheat phase
it may cause excessive slumping.
• Time: 60 – 120 s. If the preheat is insufficient, rather large solder balls tend to be generated.
Conversely, if performed excessively, fine balls and large balls will be generated in clusters.
• End Temperature: 150 – 200 °C. If the temperature is too low, non-melting tends to be caused
in areas containing large heat capacity.
Heating - Reflow Phase
The temperature rises above the liquidus temperature of 217°C. Avoid a sudden rise in temperature
as the slump of the paste could become worse.
• Limit time above 217 °C liquidus temperature: 40 – 60 s
• Peak reflow temperature: 245 °C
Cooling Phase
A controlled cooling avoids negative metallurgical effects (solder becomes more brittle) of the solder
and possible mechanical tensions in the products. Controlled cooling helps to achieve bright solder
fillets with a good shape and low contact angle.
• Temperature fall rate: max 4 °C/s
To avoid falling off, the modules should be placed on the topside of the motherboard during
soldering
The final soldering temperature chosen at the factory depends on additional external factors like
choice of soldering paste, size, thickness and properties of the base board, etc. Exceeding the
maximum soldering temperature in the recommended soldering profile may permanently damage
the module.
To Next Page
Loading...
Need help?
General
