SimCom SIM300DZ Instruction Manual

SMT Guidelines
Module de-soldering and rework_UGD_V1.01

SMT module de-soldering and rework Guidelines
Module de-soldering and rework _UGD_V1.01 07.12.2009
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Document Title: SMT module de-soldering and rework Guidelines
Version: 1.01
Date: 2008-12-07
Status: Release
Document Control ID: Module de-soldering and rework _UGD_V1.01
General Notes
Simcom offers this information as a service to its customers, to support application and
engineering efforts that use the products designed by Simcom. The information provided is
based upon requirements specifically provided to Simcom by the customers. Simcom has not
undertaken any independent search for additional relevant information, including any
information that may be in the customer’s possession. Furthermore, system validation of this
product designed by Simcom within a larger electronic system remains the responsibility of
the customer or the customer’s system integrator. All specifications supplied herein are
subject to change.
Copyright
This document contains proprietary technical information which is the property of SIMCOM
Limited., copying of this document and giving it to others and the using or communication of
the contents thereof, are forbidden without express authority. Offenders are liable to the
payment of damages. All rights reserved in the event of grant of a patent or the registration of
a utility model or design. All specification supplied herein are subject to change without
notice at any time.
Copyright © Shanghai SIMCom Wireless Solutions Ltd. 2008

SMT module de-soldering and rework Guidelines
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Contents
Version history..................................................................................................................................5
1 Scope of the document...................................................................................................................6
2 Manual soldering tools...................................................................................................................7
2.1 Manual soldering tools introduction.....................................................................................7
3 Preparation before manual soldering .............................................................................................8
4 Manual de-soldering process .........................................................................................................9
4.1 PCBA with Single side components placement ...................................................................9
4.2 PCBA with both sides components placement.....................................................................9
5 Basic considerations for manual de-soldering .............................................................................12

SMT module de-soldering and rework Guidelines
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List of Figures
FIGURE 1: MANUAL SOLDERING TOOLS.............................................................................................7
FIGURE 2: CUSTOMIZED SQUARE HOTAIR TIP....................................................................................7
FIGURE 3: HOLDING IN REVERSE .......................................................................................................8
FIGURE 4: DE-SOLDERING WITH PREHEATER .....................................................................................9
FIGURE 5: HEATING THE MODULE WITH HOT AIR SOLDERING GUN .................................................10
FIGURE 6: CHECK WHETHER THE SOLDER IS MOLTEN ......................................................................10
FIGURE 7: REMOVE THE HOT AIR SOLDERING GUN..........................................................................10
FIGURE 8: PICK UP THE MODULE WITH A PAIR OF TWEEZERS ...........................................................11
FIGURE 9: COOL DOWN .................................................................................................................11

SMT module de-soldering and rework Guidelines
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Version history
Date Version Description of change Author
2008-12-07 01.01 Origin

SMT module de-soldering and rework Guidelines
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1 Scope of the document
This document is intended for the following versions of the SIMCom modules:
•SIM300DZ
•SIM340DZ
•SIM300W
•SIM340W
•SIM700D

SMT module de-soldering and rework Guidelines
2 Manual soldering tools
2.1 Manual soldering tools introduction
NO Manual soldering tools type
1 HAKKO 850 Hot air soldering gun 220~300W 50/60Hz
2 Surface thermometer
3 Customized square hot air tip
4 Tweezers
5 Anti Electrostatic discharge wristband
6 Smoke absorber HAKKO 493
7 Repairing board cradle
8 PCB pre-heater
Figure 1: Manual soldering tools
Figure 2: Customized square hot air tip
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SMT module de-soldering and rework Guidelines
3 Preparation before manual soldering
zAssemble the customized square hot air tip on to the HAKKO850 and tighten the screw to
assure it is immovably.
zPower on the hot air soldering gun and the smoke absorber, keep a distance about 15cm
between the smoke absorber and PCBA.
zIt is recommended to set the temperature of the hot air to about 400℃ ± 20℃, the volume
of the air flow to 4.5 ± 0.5.
zCaution should be taken for the ESD protection. The operator should take the anti
electrostatic discharge wristband for avoiding damage by static discharge when contact to the
components on PCBA.
zIf there are some big size DIP package components nearby the SIM300DZ module such as
electrolytic capacitors, potentiometers which intervenes the SIM300DZ module to be heating
by hot air soldering gun. They can be removed by soldering iron in advance. In addition, if
some components are not heat resistant, they can be screened from the hot air.
zThe correct posture of holding the hot air soldering gun by hand is shown as following figure
Figure 3: Holding in reverse
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SMT module de-soldering and rework Guidelines
4 Manual de-soldering process
Recommended operation for manual de-soldering:
zHot air heating the pads of the SIM300DZ module
zCheck whether the solder is molten
zRemove the nozzle of the hot air soldering gun and remove the SIM300DZ module with a
pair of tweezers
zPut the SIM300DZ module on the smoke absorber for cooling down
4.1 PCBA with Single side components placement
If the PCBA is designed with single side placement, it is recommended to preheat the bottom of
the PCBA. Course of preheating the PCBA can permits lower soldering reflow temperature and
reduces thermal stresses to the PCB substrate when localized reflow is made with hot air nozzle.
The illumination of the operation for manual de-soldering:
zFix the position of the PCBA on the adjustable board cradle
zPreheating the PCBAwith the temperature about 150℃
zhandle the hot air soldering gun and take equably heating to the pads of the SIM300DZ
module
Hot air soldering gun
SIM300D module
Make example for PCBA
PCB preheater
Figure 4: De-soldering with preheater
4.2 PCBA with both sides components placement
If the PCBA is designed with both sides placement, it is recommended to change the soldering tip
for customized square hot air nozzle for heating with a pair of tweezers.
The illumination of the operation for manual de-soldering:
zHandle the hot air soldering gun, make the square nozzle cover the SIM300DZ module and
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SMT module de-soldering and rework Guidelines
take equably heating to the pads of the module for 2 or 3 minutes to melt the solder
Make the hot air
soldering gun is
held vertically
to the PCBA
Assure the square
nozzle can totally
cove the module
Figure 5: Heating the module with hot air soldering gun
zCheck whether the solder is molten.
Figure 6: check whether the solder is molten
Check whether the
solder is molten
with the tweezee
zOn the condition of the solder is molten, remove the hot air soldering gun reposefully and
vertically. Care should be taken that the pads of module and other components are not
damaged during remove the hot air soldering gun.
Figure 7: Remove the hot air soldering gun
zAt the moment when the solder on all pad is molten, the module can be removed by a pair of
tweezers. Firstly, insert one tip of the tweezers into the gap between module and the PCBA,
then pick up the module carefully.
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SMT module de-soldering and rework Guidelines
Figure 8: Pick up the module with a pair of tweezers
zLet the unsoldered SIM300DZ module cool down in the environmental temperature.Assure
the module can not be swashed and overturned during the whole process of cooling down.
Otherwise that may introduce the risk of artificially destruction such as components out of
the position or BGAbridges connection.
Figure 9: Cool down
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SMT module de-soldering and rework Guidelines
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5 Basic considerations for manual de-soldering
Basic considerations for manual de-soldering:
zImmobility: Do not allow the parts to move during solidification of the solder. The end of the
period of solidification of the solder can be observed by a sudden change in the appearance of
the solder surface.
zOverheating: The bodies of the components positioned in the stream of gas are often heated
more rapidly than the terminations to be soldered, so that for this reason also overheating
may be encountered.
Removal of excess solder: Removal of solder may be performed at various stages of the repair
operation. Sometimes it is useful to remove as much as possible of the solder before the module is
taken out of or off its place; in other cases the module has already been removed and then excess
solder must be taken off the solder lands before the repaired module or a new one can be replaced
and resoldered.

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Contact us:
Shanghai SIMCom Wireless Solutions Ltd.
Add: Building A，SIM Technology Building，No.633，Jinzhong Road，Changning
District, Shanghai,P. R. China 200335
Tel: [phone]
Fax: [phone]
URL: www.sim.com/wm