86
240PW9 LCD
Repair Tips
3. Lead-free productidentification
Y oucan identifylead-free product by Philips-lead-free logoon PCB.
4. Lead-free productrepair instruction
4.1 Use only lead-free Solder Alloy 0622 149 00106(1.2mm SAC305) or0622 14900108(1.0mm SAC305).
Remark: For lead free soldering material, please visit website for details. This is recommended by Philips.
4.2 Use only adequate solder tools applicable forlead-free soldering-tin. The solder toolmust be able toreach at least a
solder-temperature of 400 , to stabilize the adjusted temperature atthe solder-tip and toexchange solder-tips for different applications.
Small Passives/Actives tobe removed withthermal tweezers
Automated system for IC and BGA repair (Microscope, Camera, Beam split optics, Computer , P rogrammer, Heat controllers, V acuum
system, Laser pointer)Solder Hand-Tool (Adjustable in temperature height, Temperature shall be held constant,Flexible tips)
4.3 Adjust your solder toolso thata temperature around 360 -380 is reached and stabilized at thesolder joint.
Heating-time ofthe solder-joint should notexcee d~4sec.Avoid temperatures above 400 otherwise wear-out of tips willrise drastically
and flux-fluidwillbe destroyed.Corrosion of Tool-Spikes can be avoided when using SAC305 and a temperature ofless than 400 .
4.4 Mix oflead-free solder-tin/parts withleaded soldering-tin/parts is possible butnotrecommended. If nottoavoid clean carefully the
solder-joint fromold tinand re-solder withnew tin.
4.5 Use only original spare-parts listed inthe Service-Manuals. Standard-material(consumables) can also be purchased at external
companies.
4.6 Special informationfor lead-free BGA-ICs: this ICs willbe delivered inso-called dry-packaging toprotect the IC against moisture and
withlead-free logo onit. This packaging may only be opened shortly before itis used (soldered). Otherwise the body ofthe IC gets wet
inside and duringthe heating time thestructure ofthe I C willbe destroyed due tohigh(steam-)pressure. If thepackaging was opened
before usage the I C has tobe heated upfor some hours (around 90 ) for drying (T ake attentionfor ESD-protection!)
5. Rework on BGA (Ball Grid Array) ICs
General
Although (LF)BGA assembly yields are very high, there may still be a requirement forcomponent rework. By rework, we
mean the process of removing the component fromthe PWB and replacing itwitha new component. Ifan (LF)BGA is
removed from a P WB, the solder balls ofthe component are deformed drastically so theremoved (LF)BGA has tobe
discarded.
Device Removal
As is the case withany component that, itis essential when removing an (LF)BGA, the board, tracks, solder lands, or
surrounding components are notdamaged. Toremove an (LF)BGA, theboard must be uniformly heated toa temperature
close tothe reflow soldering temperature. A uniformtemperature reduces the chance of warping the PWB.
To dothis, we recommend thatthe board is heated untilitis certain thatall thejoints are molten. Then carefully pullthe
component offthe board witha vacuum nozzle. For the appropriate temperature profiles, see the IC data sheet.
Area Preparation
When thecomponent has been removed, the vacant IC area must be cleaned before replacing the (LF)BGA.
Removing an IC oftenleaves varying amounts ofsolder onthe mountinglands. This excessive solder can be removed with
either a solder sucker orsolder wick. The remaining fluxcan be removed witha brush and cleaning agent. After theboard
is properly cleaned and inspected, apply fluxon the solder lands and on the connection balls of the(LF)BGA
Note: Do notapply solder paste, as this has shown toresult inproblems duringre-soldering.
Device Replacement
The last step inthe repair process is tosolder thenew component on theboard. Ideally , the (LF)BGA should be
aligned under a microscope or magnifying glass. If this is notpossible, tryto align the (LF)BGA withany board markers.
To reflow thesolder, apply a temperature profile according tothe IC data sheet. So as nottodamage neighbouring
components, itmay be necessary toreduce some temperatures and times.
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More Information
For more informationon how tohandle BGA devices, visit this URL: http://www.atyourservice.ce.philips.com (needs
subscription). After login, select Magazine , then go toWorkshop Information . Here you willfindInformation onhow
.to deal withBGA-ICs.
