IPC-TM-650 TEST METHODS MANUAL (D-32) 1 …

1 1 Scope and ScopeThis methodshallbe used to simulate expo-sure to the thermal conditions by convection reflow PurposeThis methodshallbe used to replicate thethermodynamic effects by assembly on the test use of this method is intended to simulate those effectsthat are the result of soldering thermal methodshallbe used for qualification testing ofan applicable test specimen. The evaluation of acceptabilityfor qualificationshallbe in accordance with the requirementsdefined in method may be used for lot acceptance. Theevaluation for lot acceptability should be in accordance withthe requirements defined in or as agreed upon betweenuser and supplier (AABUS).2 Applicable DocumentsIPC-T-50 Terms and DefinitionsIPC-2221 Generic Standard on Printed Board DesignIPC-A-600 Acceptability of Printed BoardsIPC-1601 Printed Board Handling and Storage GuidelinesIPC-6012 Qualification and Performance Specification forRigid Printed BoardsIPC-6013 Qualification and Performance Specification forFlexible Printed BoardsIPC-6018 Qualification and Performance Specification forHigh Frequency (Microwave) Printed BoardsIPC-9241 Guidelines for Microsection PreparationIPC-9631 User s Guide for IPC-TM-650 , Method METHODS Microsectioning Microsectioning, MANUAL and Semior Automatic Method3 Test Design/Construction test specimenshallbe the A/B, AB-R, and/or theD coupon in accordance with the requirements of IPC-2221 Appendix A, or additional coupons test specimen(s)shallbe constructed with holescontained in the printed board it represents as follows:a.

2 A/B, A/B-R and D couponsshallbe constructed with boththe largest plated through-holes (PTHs) and the B/R and D couponsshallbe constructed with theintended via structure. (Multiple B/R and D coupons areused for designs with multiple structures.) test specimenshallcontain the representativeground and power planes of the printed board test specimenshallcontain the representative/applicable blind and/or buried vias of the printed test specimenshallallow for microsection evalu-ation of all the applicable, representative PTHs and viasdefined in after exposure to the conditions of this to the test specimen design/constructionor use of an alternate test specimen such as the printed boardor a section of the printed boardshallbe Drying ovenshallbe capable of maintaining a uniformset temperature within the 105 to 125 C [221 to 257 F] convection Reflow Oven or system used to simulate the thermodynamiceffects of assemblyshallbe convection Current and revised IPC Test METHODS are available on the IPC Web site ( )

3 3000 Lakeside Drive, Suite 105 NBannockburn, IL 60015-1249 IPC-TM-650 TEST METHODS Stress, convection Reflow AssemblySimulationDate08/2017 RevisionAOriginating Task GroupThermal Stress Test Methodology Subcommittee (D-32) Material in this Test METHODS MANUAL was voluntarily established by Technical Committees of IPC. This material is advisory onlyand its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of thismaterial. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent referenced is for the convenience of the user and does not imply endorsement by systemshallhave adequate environmentalcontrols to maintain the tolerance range and limits in accor-dance with the reflow profile depicted in either Figure 5-1 orFigure system should accommodate verifiable calibra-tion compliance and reflow profile generation.

4 See note foradditional test specimenshallbe handled and stored in acontrolled environment to minimize moisture ingression. SeeIPC-1601 for details on the proper handling and storage oftest to the equipment requirements andacceptability of the alternative methodsshallbe magnification used for defect recognition must bein agreement with the inspection requirements/capabilitiesdefined in the applicable performance specification ( , IPC-6012, IPC-6013, IPC-6018, etc.) and Resistance Measurements of IPC-2221 Appendix A,D specified by performance specification or pro-curement documentation, resistance measurements of theIPC-2221B Appendix A, D couponsshallbe resistance measurementshallhave enough pre-cision to clearly determine the resistance percent change asrequired by the user for the resistance level of each sample total system uncertainty from resistance, tem-perature and time/cycle variationsshallbe less than 10% ofthe failure criteria required by the user.

5 For example, if therequired failure criteria is 5% then the total system uncertaintyshallbe no greater than resistance datashallconsist of at least 1 readingper sample net every second during the entire reflow test specimenshallbe conditioned by drying inan oven to remove moisture for a minimum of six (6) hours at105 to 125 C [221 to 257 F]. This conditioning process ismandatory if this method is used for qualification methodshallreplicate the assembly process. Therequirement for conditioning (bake/drying)shallbe in accor-dance with product/process lot acceptance criteria. If condi-tioning of the printed board is not part of the normal assemblyprocess, and this method is being used for acceptance test-ing, then conditioning is not a specimens that are thicker or more complex mayrequire longer baking times to achieve acceptable moisturelevels. Record the bake times and temperature if different thanthose stated in See IPC-1601 for additional guidanceon baking to achieve acceptable moisture levels.

6 See to the conditioning requirements in as when used for acceptance criteria and/or anychanges to the time and temperatureshallbe AABUS. Reflow the test specimen in accordance with Table5-1 (default) or Table 5-2 (low temperature profile). reflow profileshallbe in accordance with eitherFigure 5-1 or Figure 5-2. Figure 5-1 represents the defaultreflow profile. Figure 5-2 represents the low temperature pro-file. The times to t1, t2 and t3 may vary based on the mass ofthe sample test specimen. To avoid over stressing of samples,times should be shortened for low mass samples. Timesshould be extended for high mass samples, such that thezone (air) temperatureshall notbe more than 25 C abovethe target surface temperature at any point in the attachment of thermocouples to the sample test speci-menshallbe such that the reflow profile is calibrated to thesurface temperature of the test test specimenshallbe subjected to a minimumof six (6) reflow cool down rateshallbe in accordance with Table5-1.

7 The cool down is complete when the test specimenreaches 30 C. The test specimenshallachieve a thermalequilibrium of 30 C or less prior to starting the next reflowcycle. If the time it takes to achieve thermal equilibrium can-not be determined, then a five (5) minute dwell between reflowcyclesshallbe to the reflow profile or number of cyclesshallbe Stress, convection Reflow Assembly SimulationDate08/2017 RevisionAPage2of8 Table 5-1 260 C Reflow Profile Specifications (Default)*ValueTime (Seconds)Temperature ( C)Descriptiont1210 15 Target preheat timet2270 10 Target peak reflow timet3330 15 Target cool-down start timet3 - t1120 30 Target time above T1T1 230 Maximum preheat temperatureT2 260 5 Target reflow temperaturePointTime (Seconds)Temperature ( C)DescriptionA030 Upper specification limit valuesB100230C195230D255265E285265F34523 0G55030H3030 Lower specification limit valuesI15793J225230K260255L280255M315230 N38330 SegmentSlope ( C / second)

8 DescriptionA-B & preheat preheat cool-down cool-down Stress, convection Reflow Assembly SimulationDate08/2017 RevisionAPage3of8 IPC-2627-5-1 Figure 5-1 260 C Reflow Profile Chart (Default)*260 C Reflow Profile Specificationst1t2t3 ABCDEFGHIJKLMNT1T23060901201501802102402 70300060120180240300360420480540600 Time (Seconds)Temperature ( C) Stress, convection Reflow Assembly SimulationDate08/2017 RevisionAPage4of8 Table 5-2 230 C Reflow Profile Specifications (Low Temperature Profile)*ValueTime (Seconds)Temperature ( C)Descriptiont1186 15 Target preheat timet2239 10 Target peak reflow timet3292 15 Target cool-down start timet3 - t1106 30 Target time above T1T1 203 Maximum preheat temperatureT2 230 5 Target reflow temperaturePointTime (Seconds)Temperature ( C)DescriptionA030 Upper specification limit valuesB88203C172203D226235E252235F305203 G48730H3030 Lower specification limit valuesI13983J199203K230225L248225M279203 N33930 SegmentSlope ( C / second)DescriptionA-B & preheat preheat cool-down cool-down Stress, convection Reflow Assembly SimulationDate08/2017 RevisionAPage5of8 IPC-2627-5-2 Figure 5-2 230 C Reflow Profile Chart (Low Temperature Profile)** The times to t1, t2 and t3 may vary based on the mass of the sample test C Reflow Profile Specificationst1t2t3 ABCDEFGHIJKLMNT1T23060901201501802102402 70300060120180240300360420480540600 Time (Seconds)Temperature ( C)

9 Stress, convection Reflow Assembly SimulationDate08 MicrosectionAfter the test specimen has been con-ditioned and reflowed in accordance with the requirements and , microsection the test specimen for compliance tothe applicable performance Resistance ChangeResistance changeshallbeused to evaluate IPC-2221 (latest revision) Appendix AD-coupons for performance based evaluation of the sampleswhen change in resistances of each sample snetsshallbe determined using the first cycle s peak tempera-ture resistance as the maximum allowable percent change in resis-tance after the test specimen has been conditioned andreflowed in accordance with and 5% maxi-mum unless otherwise to failure, corresponding percent change ofthe failure, and the percent change of the final to the stated requirements or additionalrequirements defined hereshallbe design of the convection reflow system should beflexible enough to facilitate the creation of the reflow profilesdepicted in Figure 5-1 and Figure 5-2 for all the applicable testspecimen designs encountered.

10 Some issues to consider areas follows: Thermal mass compensation capability (energy vs. time) Environmental control capability (heating and cooling) Reproducibility of parameters Preheat Conveyor speed (if applicable) Heating ramp rate Cool down rate Programming capability Profile memoryThe IPC-TM-650 website provides a non-comprehensive list-ing of providers of convection reflow systems suitable formeeting the reflow profiles within this test to the time and temperature specified in take into consideration maintaining the solderability ofthe surface finish being this method addresses assembly issues with printedboards, it is recommended that the user of the printed boardestablish a drawing note in the procurement documentation toprovide the printed board fabricators with guidance relative tothe intended reflow process of the printed board. An exampleof such a drawing note is provided as follows:Default: TEST COUPONS SHALL BE SUBJECTED TO REFLOWSIMULATION IAW IPC-TM-650 , METHOD USING THE230 C PROFILE (TABLE 5-2).