86 240PW9 LCD Repair Tips
3. Lead-free productidentification
Youcan identifylead-free productby Philips-lead-free logo on PCB.
4. Lead-free productrepair instruction
4.1 Use onlylead-free Solder Alloy 0622 149 00106(1.2mm SAC305) or0622 14900108(1.0mm SAC305).
Remark: For lead free solderingmaterial, please visit website for details. This is recommended byPhilips.
4.2 Use only adequate solder toolsapplicable forlead-free soldering-tin. The solder toolmust be able toreach at least a
solder-temperature of400 , to stabilize theadjusted temperatureat the solder-tip andto exchange solder-tips for different applications.
Small Passives/Actives to be removedwith thermal tweezers
Automatedsystem for IC andBGA repair (Microscope, Camera, Beam splitoptics, Computer,P rogrammer , Heatcontrollers, Vacuum
system, Laser pointer) SolderHand-T ool (Adjustablein temperatureheight, Temperature shall be heldconstant,Flexible tips)
4.3 Adjustyour solder tool so thata temperature around 360 -380 isreached and stabilized atthe solder joint.
Heating-time of the solder-joint shouldnot excee d~4sec.Avoidtemperatures above 400otherwise wear-out of tips will rise drastically
andflux-fluid will be destroyed.Corrosion of Tool-Spikes can be avoided when using SAC305 anda temperatureof less than400 .
4.4 Mix oflead-free solder-tin/partswith leaded soldering-tin/parts is possiblebut not recommended.If nottoavoid cleancarefully the
solder-joint from old tinandre-solder withnew tin.
4.5 Use onlyoriginal spare-parts listed in the Service-Manuals. Standard-material(consumables) can also bepurchased atexternal
companies.
4.6 Special informationfor lead-free BGA-ICs: this ICs willbe delivered inso-called dry-packaging to protect theIC againstmoisture and
withlead-free logoon it. This packaging may only be opened shortlybefore itis used (soldered). Otherwise thebody of the IC getswet
inside and during the heating time the structure ofthe IC will be destroyed due tohigh (steam-)pressure. If the packaging was opened
before usage theIC has tobe heated upfor some hours (around 90 ) for drying (T ake attention for ESD-protection!)
5. Rework onBGA (Ball Grid Array) ICs
General
Although(LF)BGA assembly yields are very high, theremay still be arequirement for component rework. By rework, we
mean the process ofremoving the component fromthe PWB andreplacing itwith a new component. Ifan (LF)BGA is
removed from a P WB, thesolder ballsof the component are deformeddrastically so the removed (LF)BGA has to be
discarded.
Device Removal
As is the case withany componentthat, it is essential when removing an (LF)BGA, the board, tracks, solder lands, or
surrounding components arenot damaged. Toremove an(LF)BGA, the board mustbe uniformly heated toa temperature
close to the reflow soldering temperature.A uniform temperature reduces the chance ofwarping the PWB.
Todo this, we recommend that theboard is heated until itis certain thatall the jointsare molten.Then carefully pullthe
componentoff the board with a vacuum nozzle. For theappropriate temperature profiles, see theIC datasheet.
Area Preparation
When the component has beenremoved, thevacant IC area mustbe cleaned beforereplacing the(LF)BGA.
Removing an IC often leaves varying amounts ofsolder onthemounting lands. This excessive soldercan beremoved with
eithera solder sucker or solder wick. The remainingflux can be removed witha brush and cleaning agent. After the board
is properly cleaned and inspected, applyflux on the solder lands and on the connection balls of the(LF)BGA
Note: Do not apply solderpaste, as thishas shown toresult in problemsduring re-soldering.
Device Replacement
The last step inthe repair process is to solder the new componenton the board. Ideally,the (LF)BGA should be
aligned under amicroscope ormagnifying glass. If this isnot possible, tryto align the(LF)BGA with any boardmarkers.
Toreflow the solder , apply a temperatureprofile according tothe IC datasheet. So as nottodamage neighbouring
components, it may benecessary to reduce some temperatures andtimes.
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More Information
For more information onhowto handle BGA devices, visit this URL: http://www.atyourservice.ce.philips.com (needs
subscription). After login, select Magazine , then go toW orkshop Information . Here youwill findInformation on how
.todeal withBGA-ICs.