Telit Wireless Solutions GainSpan GS2011M, Руководство пользователя по оборудованию

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GS2011M Low Power Wi-Fi Module Hardware User Guide
1VV0301482 Rev. 5.0 Page 65
of
69 2018-01-10
Notes:
1. Perform adequate test in advance as the reflow temperature profile will vary according to the
conditions of the parts and boards, and the specifications of the reflow furnace.
2. Max number of reflow supported are two.
3. Temperature uniformity inside the IR reflow oven must be tightly controlled and multiple
thermocouples should be used. An example of possible thermocouple locations is given in
Figure 10, page 66
. The locations should also include multiple points INSIDE the module
RF shield (e.g., TC1, TC5, and TC7 in
Figure 10, page 66
). The temperature profile of
ALL thermocouples must meet the requirements of
Table 18, page 64
.
4. Pay close attention to “Melting Time over 220
o
C”. Sufficient time is necessary to
completely melt all solder.
5. Be careful about rapid temperature rise in preheat zone as it may cause excessive slumping
of the solder paste.
6. If the preheat is insufficient, rather large solder balls tend to be generated. Conversely, if
performed excessively, fine balls and large balls will generate in clusters at a time.
7. If the temperature is too low, non-melting tends to be caused in the area with large heat
capacity after reflow.
8. Be careful about sudden rise in temperature as it may worsen the slump of solder paste.
9. Be careful about slow cooling as it may cause the positional shift of parts and decline in
joining at times.
10. A no clean flux should be used during SMT process.
Note: The modules are shipped in sealed trays with the following conditions (see
Figure 11,
page 67
).