5 Reflow Profiles

The SOM is assembled using the IPC/JEDEC J-STD-020E-compliant reflow profile.

In addition to the initial assembly solder, we recommend a maximum of two additional soldering processes:
  • Assembly on the main board
  • Spare heating pass in case the SOM must be removed from the main board for analysis

The SOM can be soldered to the host PCB by using one of the standard SnAgCu or SnBi solder reflow profile. To avoid any damage to the SOM, follow the JEDEC recommendations as well as those listed below:
  • Do not exceed solder paste recommended peak temperature (Tp).
  • Refer to the solder paste data sheet for specific reflow profile recommendations.
  • Use no-clean flux solder paste.
  • Use only one flow. If the PCB requires multiple flows, mount the SOM at the time of the final flow.
Figure 5-1. Reflow Profile Example used for Soldering the System-On-Module on an Application Board
Table 5-1. Reflow Profile Parameters According To Solder Paste Used
Symbol Profile Feature Value according to Solder Paste
Interflux DP 5600 NC-SMQ 230
Tsmin Pre-heat minimum temperature 100°C 150°C
Tsmax Pre-heat maximum temperature 120°C 180°C
TL Liquidus temperature Refer to solder paste manufacturer's recommendations (e.g. 139°C for Interflux DP 5600) Refer to solder paste manufacturer's recommendations (e.g. 220°C for NC-SMQ 230)
TP Maximum peak temperature 190°C (must be comprised between 160°C and 190°C depending on the solder paste used) 245°C (must be comprised between 230°C and 245°C depending on the solder paste used)
25 to Tsmin Ambient ramp-up rate 1 to 3°C/sec. max. 1 to 5°C/sec. max.
ts

(from Tsmin to Tsmax)

 Temperature rise 20 to 90 seconds 30 to 90 seconds
Pre-heat ramp-up rate 0.2°C to 1°C/sec. max. 0.5°C to 1°C/sec. max.
Tsmax to TL Soak ramp-up rate 1°C to 4°C/sec. max. 1°C to 4°C/sec. max.
TL to Tp Peak ramp-up rate 1°C to 4°C/sec. max. 1°C to 3°C/sec. max.
tL Liquidus temperature time maintained above TL 30 to 90 seconds 60 to 150 seconds
tP Time (tP) within 5°C of the peak temperature (TP) 15 seconds 30 seconds
TP to TL Ramp-down rate 1°C to 4°C/sec. max. 2°C to 6°C/sec. max.
– Time from 25°C to peak temperature 3 minutes max. 8 minutes max.