Process Qualification Using the IPC-B-52 Standard Test AssemblyDouglas PaulsRockwell Collinsdopauls@What is Process Qualification? An objective demonstration that an electronics manufacturing process is capable of producing finished assemblies with a desired combination of electrical functionality, known reliability characteristics (MTBF) , and cleanliness, and which meets the requirements of a target specification.Specification: May be internal, customer supplied, or nationally accepted (i.e. IPC)Apex 20062Process Qualification Standards MIL-STD-2000AAppendix A and CIPC-J-STD-001Appendix BTelcordia(Bellcore) -TelecomsSections 6 and 7, Chapters 13 and 14 International Electrotechnical CommissionIEC-61189-5ISO / JIS / DINNoneMajor Automotive ManufacturersApex 20063What the Customer REALLY Wants Some objective evidence that the assembler has done their homework and that produced hardware is cleanWarm and fuzziesWant clearly defined pass-fail metrics so that accept-reject decisions can be made without thinkingCommon sense is not all that commonWant a national level spec to call out the test, so the test is not “custom” to them You guys are the ONLY ones asking for this data Don’t want to pay for itApex 20064What Assemblers REALLY Want Clearly defined test approachClearly defined Go/NO-GO pass fail criteria that is not “too hard” to meet Pass –fail criteria that requires no thought, judgment, or interpretationA qualification report which requires no customer educationData which discriminates good from bad processes, or which identifies high risk combinationsI want a test I can pass every time, that my customer accepts, that costs me nothing.Apex 20065Important Factors If not using actual product, the test vehicle must approximate actual product as closely as possibleShould be site specificMust consider all the sources of variabilityDifferent material setsDifferent sources of supply (vendors)Different material / process interactionsDifferent manufacturing processesDifferent locations of identical processesApex 20066Process Aspects To IncludeWhat Test Vehicle to UseAs-Delivered Bare Boards & Components Standard SMT and TH reflow processes Cleaning Processes –machine and hand Hand soldering or touch-upSecondary Reflow Operations (vapor phase)Repair Operations (replace components) Coating or Potting OperationsApex 20067What Metrics To UseFocus on electrochemical related metrics Ionic CleanlinessROSE / SEC Test (TM650, 2.3.25)Modified –ROSE Test (TM650, 2.3.25.1)Ion Chromatography (TM650, 2.3.28)Effects of Residues on Electrical ParametersSurface Insulation Resistance (SIR)Electrochemical migrationDielectric strength or dielectric breakdownShifts in frequency due to residues (high freq)Apex 20068What Has Been Used In The PastIPC-B-25, B-25AIPC-B-36 (IPC-TR-580, 581, 582)IPC-B-50 (Phoenix)CSL Umpire BoardCompany Specific VehiclesIEC-TB57 AssemblyAll vehicles leave something to be desired Not representative of actual productLab based tests, not product specific tests likeMIL-STD-883 or DO-160Apex 20069What Was Desired In A Vehicle A design acceptable to the major standards development bodies –IPC / IEC / ISO Representative of mainstream materials and componentsCost efficient vehicle that builds on lessons learned from IC/SIR researchSome margin for customizationElements to test bare board characteristics prior to candidate process evaluationsClearly defined protocol and evaluation procedures, with standard reportingPass Fail Criteria based on peer-review dataApex 200610Original IEC-TB-57 Test BoardApex 200611IPC-B-52 Test BoardMain SIR Board14 patterns, room for two0402 –1206 SMTFine pitch SMTThru-hole connectorsSMT ConnectorBGA, QFP, SOICSMT chips on bottom sidefor wave solderSolder Mask Adhesion CouponsAdhesion test as deliveredAdhesion test after solderfloatNew suggested design forIPC-SM-840 qualification orIPC-6012IC Break off couponThru-hole connectorQFP (2)BGA0402 and 0805 SMTUsed to correlate extractionbased test results (IC,ROSE) to SIR performance SIR Mini-CouponsFor conformance tests1 for fabricator to test priorto shipment1 for OEM to test prior touseApex 200612IPC-B-52 Prototype Apex 200613IPC-B-52 Board (Current)Apex 200614 So back to the designer I wentApex 200615IPC-B-52 Bill of MaterialsA3276-NDAMP 536510-3TH connector 4x24 pins verticalJ1, J3211478-1575-2-ND Capacitor, 10 uF, 1206 package C39-C632510Practical Components: SO16GT-3.8mmSOIC16, 1.27 mm pitch, isolated U4-U749Capacitor, 0.01 uF, 0603 package C9-C23158TopLine: A-TQFP80-12mm-.5mm-2.0 (Amkor)QFP80 0.5mm pitch ISO U3, U1027Practical Components: QFP160-28mm-.65mm-2.6 (isolated)QFP160 0.65mm pitch ISO U2, U826CAPACITOR, 0.1uF, 0805 packageC24-C38C76-C85255WM17200-NDMolex 74136-2164SM connector IEEE 1386, 2 x 16 pins P114TopLine: BGA256T1.0-ISOBGA, 256 IO, 1 mm pitch, Isolated U1, U923CAPACITOR, 0.01uF, 0402C1-C8C64-C75202A3264-NDAMP 536501-3TH connector 4x24 pins horizontal J211PN or TopLine PNName DescriptionDesignatorNeeded ID DigiKey Practical ComponentsComponent Part Ref Qty FigureIPC-B-52 Bare Board Apex 200616IPC-B-52 Assembly Apex 200617Rockwell Collins ResearchPhase 1 –Bare Boards (prototype design) December 2004 –March 2005 (Complete) Phase 2 –Paste Evaluations (prototype) March 2005 –October 2005IC run but not interpreted, SIR PendingPhase 3 –Full Build (Revised vehicle) October 2005 and January 2006Will be reported as IPC Technical PaperApex 200618Phase 1 Bare BoardsUse prototype board (not revised)Set 1: Fabricator A, FR4 laminate, tin-lead finish (HASL), solder mask ASet 2: Fabricator A, BT laminate, tin-lead (HASL) finish,mask ASet 3: Fabricator A, FR-4 laminate, Immersion tin finish,mask ASet 4: Fabricator A, BT laminate, Immersion tin finish, mask ASet 5: Fabricator B, FR4 laminate, tin-lead finish, mask BSet 6: Fabricator B, FR4 laminate, immersion tin, mask B Tested in the As-Received ConditionSIR on Main Board, SIR on Mini-Coupons, IonChromatography on IC Coupons, Solder mask adhesionApex 200619Ion Chromatography Extraction of coupons in 10% isopropanol and 90% DI water, 80C for 60 minutesExamine extract solutionChromatograph separates ionic fractionsResults in a chromatogramConverted to ug/cm2Apex 200620Repeatability Study Took extract solution and sent to other labs –all using different equipment and methodsRockwell Collins, Cedar Rapids, IAPrecision Analytical Labs, Kokomo, INTrace Laboratories East, Hunt Valley, MDResearch in Motion, Waterloo, OntarioDionex, Sunnyvale, CADelphi Delco Electronics, Kokomo, INApex 200621Apex 200622IC Results -ChlorideIPC-B-52 Ion Chromatography - Chloride Residues0.000.200.400.600.801.001.201.401.601.802.00A-F-HA-F-IA-B-HA-B-IB-F-HB-F-ITest SolutionM i c r o g r a m / S q . C m .RIMRockwell Delco Trace PAL DionexApex 200623IC Results -SulfateIPC-B-52 Ion Chromatography - Sulfate Residues0.001.002.003.004.005.006.007.00A-F-HA-F-IA-B-HA-B-IB-F-HB-F-ITest SolutionM i c r o g r a m / S q . C m .RIMRockwell Delco Trace PAL DionexApex 200624IC Total AnionsIPC-B-52 Ion Chromatography - Total Anion Residues0.001.002.003.004.005.006.007.008.00A-F-HA-F-IA-B-HA-B-IB-F-HB-F-ITest SolutionM i c r o g r a m / S q . C m .RIMRockwell Delco Trace PAL DionexApex 200625IC –Total CationsIPC-B-52 Ion Chromatography - Total Cation Residues0.000.501.001.502.002.50A-F-HA-F-IA-B-HA-B-IB-F-HB-F-ITest SolutionM i c r o g r a m / S q . C m .RIMRockwell Delco Trace PAL DionexConclusions –Ion Chromatography Generally good agreement between test labs –all running different equipment, methods and calibrationsMethods can use some improvementNo “acceptable” or “unacceptable” levels yet determined –but lower is betterIPC Bare Board Cleanliness Task Group (5-32c) is pursuingDesire to make recommendations to IPC-6012groupApex 200626SIR TestingApex 200628SIR Testing –Main BoardsInitial SIR Main Board Run2030405060708090100991199129913991499159916991Test Time in MinutesD e g C o r %R HTempHumidity10 VDC constant, multi-phase profileData logged every 60 minutes (AutoSIR), bias and measurement voltages same polarity35/85 is Bellcore, 40/93 is German DIN, 85/85 is classical IPC SIR method12502552485-9085448934032485-90352250251Duration (hrs)Humidity (% RH)Temp (o C)SegmentSIR Test Setup 32/32 position FEPconnector, goldcontactsFEP insulated ribboncableChecked for bothisolation and shortsbefore and aftertestingSome “hiccups”experienced withAutoSIRApex 200629Apex 200630SIR –Pattern 3 –No Dendrites67891011124812162024283236404549535761656973778185899397101105109113117122Hours in TestR e s i s t a n c e i n L o g O h m sB-F-I B-F-H A-F-H A-B-I A-F-I A-B-HApex 200631SIR –Pattern 7 -Dendrites67891011124812162024283236404549535761656973778185899397101105109113117122Hours in TestR e s i s t a n c e i n L o g O h m sB-F-I B-F-H A-F-H A-B-I A-F-I A-B-HApex 200632SIR –Pattern 10 -Dendrites67891011124812162024283236404549535761656973778185899397101105109113117122Hours in TestR e s i s t a n c e i n L o g O h m sB-F-I B-F-H A-F-H A-B-I A-F-I A-B-HApex 200633SIR –Classic Grow and Blow67891011124812162024283236404549535761656973778185899397101105109113117122Hours in TestR e s i s t a n c e i n L o g O h m sB-F-I B-F-H A-F-H A-B-I A-F-I A-B-HDendritic Structures Apex 200634Conclusions –SIR Main Board Monitoring every 60 minutes can catch dendritic growthNo instances of dendrites where the data does not catch it, but some false indications from water dropletsWater spots indicate that chamber was not fully in control (old chamber)Even shielding with a rain shield insufficient to protect against water spots In a majority of cases, the 100 megohm classical IPC lower limit for SIR seems to differentiate between good and badApex 200635Open OfferRockwell Collins will test five bare boards IC, SIR –Main, SIR –Mini, Solder MaskFree of charge (string attached)Will do multiple sets of five boards, also free Doug gets all background databoard fabricator, fabrication location, laminatematerial and associated IPC-4101 designation,solder mask type and brand name, and surfacefinishThis will be held confidential and codedFor everything else –you are on your ownApex 200636Questions Apex 200637。
