The Digi m10 Satellite Modem can be incorporated in Select Solder or Wave Solder processes.
Select Solder – No specific fixtures are needed, cycle time slower than wave solder
Wave Solder - No-clean flux, no-lead solder (268 Degrees Celsius, <5 seconds)
NOTE: Digi recommends turning top side preheating off, with bottom side preheating only. This will reduce exposure of the Digi m10 module to excessive heat affecting the product marking (label).
NOTE: Placing the Digi m10 on the top side of a carrier PCB with SMT components on both sides requires a cavity type wave solder fixture. Such a fixture provides cut-outs to protect the bottom side SMT components from unwanted exposure to the solder pot during the Digi m10 wave solder process.
Wave Solder Machine used by Digi
• Electrovert Econopak-Plus Wave Soldering Machine with 17” wide conveyor, 440/480 VAC, 3 Phase, Electrovert USA Corp., Camdenton, Mo. 65020
This machine has two topside preheat panels at 2ft each and 2 bottom side preheat panels at 2ft each
• Solder Mfg settings as listed below
Preheat Solder Wave Temperature Process Dwell Time
100-115° 260-270°C 5 seconds minimum 6 +1/-1 secs
• Bar Solder - SN100C .
Sn 99.2%, Cu 0.7%, Nickel 0.05%, Ge 0.009%; Bar form, Lead-Free, RoHS Compliant.
• Wave Flux - Alpha EF 2202A .
VOC-Free, halide-free, rosin/resin-free, Acid number of 30.0, 3.5% solids, meets J-STD-004 Class OR-L0.
The thermal couples were placed on the top side of the PCB next to the legs of the M10 module.
Is baking necessary prior to wave soldering the board?
Digi does not bake the assemblies prior to wave soldering the board. However, our humidity is relaitvely low (30 to 35%) for most of the year and during winter months we are in the low 20% range. A customer's environment can be much higher 60 to 70% humidity range. Process engineer should find this out. If the humidity is high then the assemblies should be baked otherwise it is risking de-lamination of the board. The concern is when the moisture hits the high preheat temperature on the wave solder process it turns to a gas (stream) and will escape the laminate. Potentially causing de-lamination of the PWB.
Bake times 4-6 hours @ 85C.
How to determine Preheat, Solder Wave Temperature & Dwell Time:
Preheat is the activation temperature of the flux and is defined the by flux manufacturer.
Customer need to refer flux manufacturer's application notes for the correct activation temperature.
Solder Temperature is defined by the bar solder used.
Dwell time is defined by the application notes of the Bar Solder Manufacturer.
Customer needs to develop a reflow or wave solder profile that meets the peak temperatures and dwell times as defined by Digi.
If you have specific questions and/or need additional guidance, please contact Digi technical support team.
Jun 05, 2019