ELECTRONICS INDUSTRIES Monotonic Bend Characterization …

1 IPC/ jedec -9702 Monotonic BendCharacterizationof board -LevelInterconnectsDeveloped by the SMT Attachment Reliability Test Methods Task Group(6-10d) of the Product Reliability Committee (6-10) of IPC and theJEDEC Reliability Test Methods for Packaged Devices Committee( )Users of this publication are encouraged to participate in thedevelopment of future :IPC2215 Sanders RoadNorthbrook, Illinois60062-6135 Tel 847 847 State Technology Association2500 Wilson BoulevardArlington, VA 22201-3834 Tel 703 703 CONNECTINGELECTRONICS INDUSTRIES Table of 14 TERMS AND 15 SYMBOLS AND ABBREVIATED Tester .. Measurement Equipment.

2 Monitoring Equipment .. Sample .. board Material .. board Thickness and Metal Layer Count .. board Surface Finish .. board Land Pads .. board Layout .. board Daisy-Chain Links .. Assembly .. Strain Gages .. Set-Up Test board .. Four-Point bend Test .. 69 FAILURE CRITERIA AND 7 ANNEX 9 ANNEX 12 FiguresFigure 7-1 Universal Tester .. 2 Figure 8-1 Test board Layout .. 4 Figure 8-2 Rectangular Package Orientation .. 5 Figure 8-3 Single Package Daisy-Chain Configuration(Example) .. 5 Figure 8-4 Strain Gage Placement .. 7 Figure 9-1 interconnect Fracture Modes (SolderBall Array Devices).

3 8 Figure Example Configuration (PWB Thickness= mm) .. 9 Figure Example Configuration (PWB Thickness= mm) .. 10 Figure Example Configuration (PWB Thickness= mm) .. 11 TablesTable 7-1 Universal Tester Requirements .. 2 Table 8-1 Recommended TestBoard Thickness & Layer Count .. 3 Table 8-2 Test board Layout Requirements .. 4 Table 8-3 Monotonic bend Test Requirements .. 7 Table Test Report Recommendations(Equipment & Materials) .. 12 Table Test Report Recommendations( board Assembly) .. 12 Table Test Report Recommendations(Test Results) .. 12 IPC/ jedec -9702 June 2004ivMonotonic bend Characterizationof board -Level Interconnects1 FOREWORDThis publication on Monotonic bend testing is intended tocharacterize the fracture strength of a component s board -level interconnects.

4 The document is applicable to surfacemount components attached to printed wiring boards usingconventional solder reflow technologies. The monotonicbend Characterization results provide a measure of fractureresistance to flexural loading that may occur during con-ventional non-cyclic board assembly and test operations,and supplements existing standards that address mechani-cal shock or impact during shipping, handling or INTRODUCTIONS emiconductor devices are assembled in a variety of pack-age configurations, and are used in a multitude of applica-tions. Given the diversity of package constructions andend-use conditions, it is not feasible to establish a singlequalification requirement relating to bend testing; however,definition of a uniform test methodology and a standardreliability Characterization reporting process are increas-ingly necessary to ensure adequate product SCOPEThis publication specifies a common method of establish-ing the fracture resistance of board -level device intercon-nects to flexural loading during non-cyclic board assemblyand test operations.

5 Monotonic bend test qualification pass/fail requirements are typically specific to each device appli-cation and areoutsidethe scope of this TERMS AND DEFINITIONSFor the purposes of this standard, the selected terms anddefinitions listed below TermsComponent:Packaged semiconductor deviceInterconnect:Conductive element used for electricalinterconnection, , solder ball, lead, Test:Non-reversing, test to failStrain Related TermsGlobal PWB Strain:Four-point bending strain of uniformprinted wiring board , ignoring any effects due to the pack-age(s)Microstrain:Dimensionless unit, 106x (change in length) (original length)Strain:Dimensionless unit, (change in length) (originallength)Strain-Rate:Change in strain divided by the time intervalduring which this change is measuredStrain Gage:Planar copper foil pattern that is adhered toan underlying surface and exhibits a change in resistancewhen subjected to a strainStrain Gage Element:Sensing area of strain gage definedby the serpentine copper grid patternUniaxial Strain Gage:Strain gage incorporating a singlestrain gage element, , capable of detecting strain along asingle axisMechanical Test Equipment TermsAnvil.

6 Four-point assembly fixture support with a roundedcontact surfaceCrosshead Assembly:Clamping/attachment assembly ofuniversal tester that moves relative to the base of the testequipment, and creates the forces necessary for specimentestingFour-Point Bending Fixture:Test assembly that supports aspecimen on two anvils or rollers, and symmetrically loadsthe specimen on the opposite surface with two anvils orrollersLoad Span:Distance between the two anvils or rollersthat load the test specimenRoller:Four-point assembly fixture support that incorpo-rates a cylindrical bar as the contact surfaceSupport Span:Distance between the two anvils or rollersthat support the test specimenUniversal Tester:Test equipment capable of tensile/compressive loading using controlled linear motion of acrosshead assemblyElectrical Test TermsDaisy-Chain:A conductive link that can be connected inseries with other conductive links (like a chain of daisies)to form a continuous electrical netIn-Situ Measurement.

7 Measurement conducted during atest, , in place, rather than during an interruption of thetest conditionFailure Analysis TermDye-and-Pry:Dye exposure of package/ board assemblyfollowed by mechanical removal of the packageJune 2004 IPC/ jedec -97021