Dragon Group China Bird AC-5K User manual

龙集团 DragonGroup China Limited
BIRD
www.dragongroupchina.com
www.chinaemall.biz
BGAReworkStation AC-5K
DragonGroup ChinaLimited
Address: Fuxin BuildingOffice12DNo.318 FuhuaRoadShenzhen,
China.518000
Telephone: [phone] (86)755 83292149 Fax [phone]
Http ://www.dragongroupchina.com www.chinaemall.biz

龙集团 DragonGroup China Limited
BIRD
www.dragongroupchina.com
www.chinaemall.biz
Contents
A. BGAReworkStation
B. Installation
C. SafetyCautions
D. Introductionof Structure
E. OperationSteps
F. PLC(Programmable logic Controller）
G.CurveProgramController
H.Relatedinformation
I. Tipsforoperation

龙集团 DragonGroup China Limited
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A. BGAReworkStation
1. KnowledgeaboutBGA
BGA isshortfor Ball GridArray.Itisakind of packagemethod whichuseorganic
carrier in IC. Ithasthefollowingfeatures:
Small packagearea.
②Greater functionsand morepins.
③Self-centerizewhile PCB puddle welding, easyto puton tin.
④Morereliable.
⑤Good conductivityand lowoverall cost.
MemorywhichappliesBGA canenlargethememorycapacityby2to3timeswhile the
volume ofmemoryremainsthesame.ComparedwithTSOP,BGA ismuchsmallerand
better atradiatingand conductingelectricity.
2. TypesandFeaturesofBGA
a. Types
Accordingto theencapsulation material,BGA can beclassified into thefollowingtypes:
(1)PBGA（Plastic BGA）
(2)CBGA（CeramicBGA）
(3)CCBGA（CeramicColumn BGA）
(4)TBGA（TapeBGA）
(5)CSP (Chip ScalePackageor MBGA)
b. Features
Compared with QFP, BGA hasthefollowingfeatures:
(1) I/Oterminal spaceisbig(eg.1.0mm, 1.27mm,1.5mm),anditcan accommodatemore
I/O.
(2) Morereliable package,lowrateofweldingdefectsand weldingspotdurable.
(3) Paraposition ofQFPisusuallyobservedwithnakedeyes.Whenthepinspaceis
smallerthan0.4mm,itishard toparapositionandweld. WhilethepinspaceofBGA is
bigger, byapplyingtheparaposition-amplificationdevice,itiseasytoparapositionand
weld.
(4) TheweldingcoplanarityofBGAisbetterthanQFP,becausesoldercanmakeup the
flat error between BGA and PCB after melting.

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(5)Good electricalproperty.Thepinsaresmall,theselfinductanceand mutualinductance
oftheconductivityislow, and thefrequencycharacteristicisgood.
(6)Thetension betweensolderpointsproducesgood self-centrationeffect in
solder-reflow, allowing5% error ofpatch precision.
(7)Compatible withoriginal SMTmounttechnologyand machines.Theoriginal screen
printermachine,mounterand solder-reflowmachineall canbeused. Thecomparison
betweenBGA and QFPisshowninTable1. ThemaindefectofBGA isthenecessityof
X-raydetection after welding.
c.WeldingofBGA
Thesuccess ofweldingBGAisaffectedbytheassemblyofPCB. So3keyfactorsmust
beconsideredin thelayoutofPCB.
Features BGA QFP
PackagesizeS/m2525 1600
Pin space L/mm 1.27 0.50
fault rate ( 10-6/pcs）
0.60 100
(1)ThermalmanagementThermal managementmustbeconsideredwhenwedesignthe
assemblyofPCB. IfmanypiecesofBGA gatheron asmallareaofPCB, itwillcausethe
imbalanceofPCB inthereflowoven. IfmanybigpiecesofBGA gatheronacertainarea
ofPCB, longerheatingperiod willdamagesome oftheBGA.Theareaswithfewer
componentshavereachedtheweldingtemperature,whilethoseareaswithBGA arestill
inlowtemperature.Sotheweldingperiod isoverbeforetheflux paste withdraws from
theweldingspots, thustheremaybepoor solderingor no-meltingofweldingballs.
(2)Rabbet
Thedesignofrabbet on PCB shouldsticktorelevantstandardsstrictly.Anyrabbet
nearBGA weldingpadmustcoverthesoldermaskverywell.Ifnot,theextrawelding
paste will flowfromtheweldingpadtotherabbet,thenleadstoshortcircuit between
weldingpad and rabbetsnearby.
Thegeometricshapeand diameter ofweldingpad:
Thecompactness ofpinshasimmediate impact on thegeometric shapeand diameterof
weldingpad. Similarly,BGA hasdifferentsizes,shapesand complexity.Asthepackage
sizedecreases,thegeometricshapeanddiameteroftheweldingpadcallsfor higher
precision in detection.

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3. Inspection standards ofBGA
For BGA assembledonPCB, inspection standardisaveryimportantissue.Before
BGA isappliedtothePCB, mostBGA manufacturersdon'tuseX-rayinprocess of
inspection. Instead,theyemploysome traditional methodstotestPCB, suchasautomatic
optical inspection, man-eyeinspection or on-linefunctiontest.However, thesemethods
can'tdetect theinvisibleproblemsveryexactly,suchaspoor soldering,coldweldingand
bridging.TheX-raycandiscovertheseproblemsveryefficiently.Atthesame time,it can
do livemonitoring,guaranteethequality,and realizethein-timefeedbackoftheprocess
control,
a. Evaluation ofX-ray
WhenBGA isfirstusedon BGA,X-raycanevaluate thesolder-reflowaccordingtothe
situation ofun-solder areaor areasaround it. Open-circuit, non-touchingand other similar
situationsshowthesolderpastehasnotreflowenough. Bridgingmayresultfromthefact
that thetemperatureistoohighfor thesoldertoliquefy.Sothesolderflows fromthepad
to theinterval betweenthem, causingshort-circuit.
Poor weldingshouldbeevaluatedobjectively:it isnotsoterrible; thekeypointisthatthe
weldingspotscanstill beweldedon thepad. Theideal situation isno poor welding.Poor
weldingmaybecaused bypollution or theuneven distribution offlux paste. What's more,
warped PCB mayalso lead to poor welding. Open-circuitweldingspotmayexist, too.
Thequantityand sizeofpoor weldingarethekeyfactorstodecidewhetherit will
beaccepted. Generallythesize ofsingle poorweldingshouldbeless than50% ofthe
solderball's diameter. If theballissurroundedbyreflowsolder, BGA isabletowork. It
isaverycriticalstandard.Theelectricalpropertiesmaymeet therequirementsbutthe
mechanicalstrength will beaffected.
PCB withBGA mustuseX-rayevaluation systemsthat candecern holesofless
than100 mdiameter. TheX-raymustbeable toobservefromtop-downandtilt.X-rays
isareliable guaranteeofsuccessfulBGA welding,
b. Proposed inspection criteria
Theinspectioncriteria will helpX-rayinspectionsystem confirmsometypical
weldingproblems,whichisrelatedwiththeuseofBGA device.Itincludesthefollowing
factors:
(1)Poor welding
Poor weldingresultsfromtheexpansion ofcompoundsinsolderduringtheheating
ofBGA.BGA withpoorweldingmaycausesomeproblemssuchasineffectiveness.The
inspection criteriasareasfollows:thesizeofsingle poor weldingshouldbenomorethan
20% ofthesolderball's diameter, withno single poor weldingon thesurface;ifmany
poor weldingmayexist,thetotalshouldbeno morethan20% ofthesolderball's
diameter.
(2)Desolderingspots

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No desolderingspots.
(3)Bridgingand short-circuit.
Whenthereisextrasolderor thesolderisnotputon therightplace,bridgingand
short-circuitmayhappen. So no bridgingor short-circuit.
(4)Noneparaposition.
TheX-rayimagewill showveryclearlywhethertheBGA solderballisaimedat
theweldingpad on PCB.
(5)Brokencircuit and coldwelding
Whensolderdon'ttouchtherelevantpador thesolderdoesn’tflowverywell,there
will bebrokencircuitor cold welding. Itisabsolutelynotallowed.
4. BGA reworkprocess
Mostofthesemiconductor device’sheat-resistanttemperaturesarebetween 240°C and
600 °C. Therefore, thecontrolofthetemperatureanduniformityareveryimportantto
BGA rework systems. BGA rework process asfollows:
a. Printed CircuitBoard and BGA preheating
Printed CircuitBoard and BGA’spreheatingismeantto wipeoff themoisture.Ifthe
moisturewaslittle, thisstep can beomitted.
b. RemoveBGA
IftheBGA will notbereused, and thePCB canendurehightemperature,wecanuse
high temperature(shorterheatingperiod) to removeit.
c. Clean thepad.
Padcleaningismainlyclearingthesolderpaste andscalingpowderremainedon
thesurfaceofPCB afterBGA removal.For thatprocess,itmustusestandard cleaning
agent.ToensurethereliabilityoftheBGA solders,generallywecannotusetheremained
solderpaste inthepad, and wemustclearawaytheusedsolderpaste,exceptthat solder
ballsreformon theBGA.BecauseofthesmallsizeofBGA,especiallyCSP(or BGA
smaller), itisalwaysdifficulttocleaningthepad,sowhenreworkingCSP,it needstouse
Rinse-free Flux ifthespacearound CSPisverysmall.
d. Layon BGA Flux Paste
Layingsolder pasteon thePCB hasimportantinfluence on theresult ofBGA Rework. It
isconvenienttolaysolder paste on thePCB byselectingmould matched withBGA.For
CSP, therearethreesolder pastesfor choice,includingflux paste, clean-free and
water-soluble. If wechoosetheflux paste,thereflowtimeshould belonger, ifchoosethe
clean-free solder paste, reflux temperatureshould belower.

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(1) Mounting:ThemainpurposeofmountingtomakeeveryBGA solderaligntothe
PCB pad with special equipment.
(2)Hotairreflow:Hotairreflowsolderingisthekeyto thewhole BGA Rework.
ThecurveofreflowsolderingofBGA Rework should besimilar with theoriginal
solderingone. Hotair reflowsolderingcurvecanbedivided into four zones, including
preheat zone, heatingzone, recirculation zoneand coolingarea. Thesefour zones’
temperatureand timeparameter can beset respectively, when it connectswiththe
computer, theseprogramscan besaved and transferred at anymoment.
②In reflowsoldering process, we mustchoose the rightheatingtemperatureand time of
differentzones;atthe same time, we should notice the heatingspeed. Commonly,the
maximalheatingrateisnotmore than 6℃/sbefore100℃, and the maximalheating rate isnot
more than 3℃/safter100℃. In the coolingzone, themaximalcoolingrateisnotmore than 6
℃/s,because bothofthe exorbitantheatingrate and coolingrate maycause damage to PCB
and BGA, which sometimescannotbe observed byunaidedeyes. FordifferentBGA and
different solder pastes, weshould choose differentheatingtemperature andtime. For
example, reflux temperature ofCBGA BGA should be higherthanthatofPBGA…choose
the higher reflux temperature. For no clean solder paste, its activity islowerthan non-no
clean solder paste, sothe solderingtemperature should notbe too high, andthe soldering
time should notbe too long, so asto preventtheoxidation ofsolder particle.
③In hotair reflowsoldering, thebottomofPCB board should beheated. Therearetwo
purposesfor thiskind ofheating. First, avoid thewarpingand deformation in one-side
heated PCB board;second, shorten thetimeofthesolder paste melting. For the
dimension pad ofBGA rework, thiskind ofheatingon thebottomofPCB isespecially
important.Therearetwowaysofheatingon thebottomofBGA rework equipment. One
ofthem ishotair heating, and theother isinfrared rayheating. Theadvantageofhotair
heatingisthehomogeneousheating, which common Rework Techniquessuggestto adopt
thiswayofheating. What opposite with itisthedisadvantageofinfrared ray’s
inhomogeneousheating.
④Weshouldchoosetherighthotairreflux suctionnozzle.Thehotairreflux nozzle is
non-contactheating,whichdepend onthehightemperatureaircurrentmakeeverysolder
ofjointon BGA meltsynchronously.For that reason, it ensuresthesteadytemperature
circumstanceinthewhole ofreflux process,anditprotectstheadjacentpartsfrom
damagingbytheconvectivehotair’sregeneration.
B. Installation
1. Place
InordertoensurethevalidityofBGA Rework Station, theinstallation shouldmeetthe
followingrequirements.
a. Awayfrominflammableand explosives;

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b. Awayfromwaterand other liquids;
c. Ventilated, dryplace;
d. Stableand flat, free fromtremor.
e. Less dust;
f. No heavyobjectson thecontrollingbox;
g. Notaffected byairflowofair conditioner, heater or ventilator.
h. Leaveaspace of30cm or morebehind therework station for theupperparttomove
and rotate.
2. Power supply:
a. Useapower supplywith little fluctuationsinvoltage.
b. Fluctuation:220V±10
c. Frequencyfluctuation:50Hz±3
C. SafetyCautions
1. Don'tblowto therework station directlywhen it isworking, or therewill beanegative
difference fromthesurfaceoftheheatingboard, thussome partswill beburntout.
2. After it isstarted,thehigh temperaturearea should nottouch anyobjects, orit willlead
to afireor explosion. ThePCB and other partsshould beputon thePCB bracket.
3. No vibration. Handle it gently.
4. Don'ttouchtheheaterswith your handswhen it isworking, or you will get hurt.
5. Don'tusecombustible spray, liquefied and flammable gasnear therework station after
it isstarted.
6. Don'ttryto re-equip themachine,or theremaybeafireor anelectric shock.
7. Therearehigh-pressurepartsinthecircuit box. Don'tdisassemble it.
8. Ifsome metalsfall in therework station when itisworking, turn off thepower
immediately. After it iscooled down, get themetal out, and clean themachine.Ifnot,
theremayasmell when themachinestartsworkingnexttime.
9. When therework station's temperaturerisesabnormallyor smokes, turn off thepower
and informtheservice techniciansto repair it. Turn offthepower ofthecircuitbox and
thethemachinewhile movingtherework station. Hold theplugwhen weremovethe
wire, or itwillleadto apoor contactthen themachinecan'twork verywell.

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10. Turn off thepower when stop usingit.
11. Don'tputtherework station on thewires, or theremaybeafailure, afire,or an
electric shock.
12. Beforeyou usethemachine,you mustread theinstructionsattentively.
Note: whenthemachineworks,it willproduce some smell.Soensurethecomfortable,
healthyand safeoperationenvironment, pleasekeeptheair incirculation.
D. Introductionof Structure
Introductionofhost labels
1. Topheater tempcontrol2. Bottomheater tempcontrol
3. Top breezeadjust4. Start
5. Runningshow6. Stop
7. CoolingAUTO/HAND 8. Power
9. Heat box10. PCB fixer

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11. Heater
Specification:
1．Total power 2.5 KW
2．Top heater 0.5 KW
3．Bottomheater 2.0KW
4．Power supply 220V±10 50Hz±3
5．Dimension 450×400×580mm
6．Temperaturecontrol Ksensor
7．Positioning:V-groovefor PCB positioningMax PCB size: 280×320mm mm
8．Weight 20kg
Features:
1. Chooseimportedhigh-precision materials(temperaturesensor, PLC, heater) tocontrol
BGA desoldering&solderingproceduresprecisely.
2. Top &bottomtemperatureareasheatindependently,And it canset up 8rising
temperaturesegmentsand8constanttemperaturesegmentstocontrol.Itcansave10
groupsoftemperaturecurvesat thesame time.
3. Chooseimportedhigh-precision thermocouple todetectthetop/bottomtemperature
precisely.
4. Top &bottomheatingcanbecontrolledindependentlybythetemperaturegraphs.A
cross-flowfan coolsrapidlyto protect thePCB fromdeformation when welding.
5. Thismachinecanbeconnectedtoacomputertobecontrolledmoreconvenientlywith
abuilt-in PC serialportand aproprietarysoftwareattached toit.
6. Afterfinishingdesoldering&soldering,thereisanalarming.Themachineisequipped
with avacuumsuction pen to facilitate theremoving ofBGA after desoldering.
7. For largethermal capacityofPCB or otherhigh-temperatureand lead-free welding
requirements, all can behandled easily.
E. OperationSteps
1. Preheating
PreheattheBGA andPCBbeforerepairing. Thetemperatureinthermostatisusually
set at80℃-100℃,time12-24 hours,toremovethemoistureinPCBandBGA,and
preventburstwhenheating.