Pre-Baking Of Integrated Circuits - Motorola MTM800 User Manual

7 - 6
5. Position the heat-focus head over the shield.
6. Turn on the heater and wait for the solder to reflow.
7. Once complete, turn off the heat, raise the heat-focus head and wait approximately one
minute for the part to cool.
8. Remove the circuit board and inspect the repair. No cleaning should be necessary.

Pre-baking of Integrated Circuits

Electronic components are generally coated with plastic material which has the nature of not being
waterproof. If kept unsealed the components can absorb humidity. When soldered to the board
(especially with reflow techniques) the sudden change in temperature can cause fissure or crack
which can result in malfunction or damage.
To avoid this problem these moisture sensitive components (MS) should be stored and shipped in a
sealed wrapping (dry pack). Processing must take place only with "dry components" when an
uninterrupted dry storage can be guaranteed, otherwise the components have to be pre-baked.
If a reflow procedure takes place close to MS components the whole board must be pre-baked.
Table 7-3 List of MTM800 ENH moisture sensitive components
Part. No. MSL*
5166554A01
5109841C71
5186988J77
5185956E43
5185963A85
5166541A01
5189233U61
5199434A01
*) Out of dry package Moisture Sensitivity Level (MSL) 2 : 1 year
Description
3 ADDAG
3 GAM IC (on GPS option board)
3 JAVELIN
2A FLASH 16MB
3 ABACUS AD9874
3 Patriot ROM3
3 PSRAM 4MB
2 Serial SPI EEPROM
2A : 1 month
3 : 168 hrs
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