u-blox SAM-M8Q Integration Manual

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u-blox SAM-M8Q Integration Manual Manual pdf 14 page image

SAM-M8Q - Hardware Integration ManualUBX-16018358 - R05 Production Information Product handlingPage 14 of 233 Product handling3.1 Packaging, shipping, storage and moisture preconditioningFor information pertaining to reels and tapes, Moisture Sensitivity levels (MSL), shipment and storageinformation, as well as drying for preconditioning see the SAM-M8Q Data Sheet [1].Population of ModulesWhen populating the modules, make sure that the pick and place machine is aligned to the copper pinsof the module and not to the module edge.3.2 SolderingSoldering pasteUse of "No Clean" soldering paste is highly recommended, as it does not require cleaning after the solderingprocess 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 °CStencil Thickness: 120 umThe final choice of the soldering paste depends on the approved manufacturing procedures.The paste-mask geometry for applying soldering paste should meet the recommendations.Reflow solderingA 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, regardlessof 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 phaseDuring the initial heating of component leads and balls, residual humidity will be dried out. Note that thispreheat 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 causeexcessive slumping. Time: 60 - 120 s. If the preheat is insufficient, rather large solder balls tend to be generated. Conversely, ifperformed 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 areascontaining large heat capacity.Heating/ Reflow phaseThe temperature rises above the liquidus temperature of 217 °C. Avoid a sudden rise in temperature as theslump of the paste could become worse. Limit time above 217 °C liquidus temperature: 40 - 60 s Peak reflow temperature: 245 °C