ELECTRONICS INDUSTRIES Guidelines and …

1 IPC-9252 Guidelines andRequirements forElectrical Testingof UnpopulatedPrinted BoardsDeveloped by the electrical Continuity testing Task Group (7-32c)of the Automatic Inspection Technologies Subcommittee (7-32)of the Product Assurance Committee (7-30) of IPCU sers of this standard are encouraged to participate in thedevelopment of future :IPC2215 Sanders RoadNorthbrook, Illinois60062-6135 Tel 847 847 CONNECTINGELECTRONICS INDUSTRIES February 8, 2001 Table of .. of the Proper Test Level.

2 22 APPLICABLE 23 TERMS AND Features .. Automated Design (CAD) Net .. testing .. Test System .. Time (Tester Loading).. Sided Access Plate Fixture .. Wired Test Fixture .. Potential Test (Hipot)/High Potential(Voltage) Test .. Land .. Probe .. (Net) .. Item .. Hole .. Board .. Cassette .. Learn .. Domain Reflectometer (TDR) .. Fixture .. 44 TEST Test .. Voltage .. Resistance .. Current .. Test .. Voltage.

3 Resistance .. Current .. Parameter Matrix .. Continuity and Isolation electrical Test .. Difference Between Nodes and Vias .. Midpoints and Endpoints .. Network Topologies .. Endpoint Identification Off-PWB Item Connection Points (Nodes) .. of Test .. Other than Continuity and Isolation .. 85 TEST PROGRAM Test .. Overview .. and Weaknesses .. Net List Test .. Overview .. and Weaknesses .. Net List Test .. Overview .. and Weaknesses.

4 106 SURFACE MOUNT .. 107 CHARACTERIZATION Potential (Hi-pot) testing .. 11 February Current .. Precaution .. Test Procedure .. Test Equipment .. Pulse Amplitude .. Test Limits .. Calibration .. Capacitor Test Stimulus .. Resistor Resistor Test Carrying Capacity .. 128 HARDWARE Considerations .. The Tester .. The .. 129 STATISTICAL PROCESS CONTROL (SPC) FORELECTRICAL TEST Equipment Implications for SPC .. 13 FiguresFigure 1-1 ATE Selection 1 Figure 4-1 Continuity Test.

5 4 Figure 4-2 Isolation Test .. 4 Figure 4-3 Example Midpoint 5 Figure 4-4 Examples of Acyclic, Cyclic, andBuried Plane .. 6 Figure 4-5 Example of an Endpoint Identification .. 6 Figure 4-6 Surface Plane to BGA Ground Connection .. 7 TablesTable 4-1 Test requirements by 5 IPC-9252 February 2001ivGuidelines and requirements for ElectricalTesting of unpopulated printed Boards1 SCOPEThis document is presented to assist in selecting the testanalyzer, test parameters, test data, and fixturing requiredto perform electrical test(s) on all unpopulated printedboards without embedded components ( , resistors,capacitors, etc.)

6 The users must determine the test parameters and fixturingrequirements to test for continuity (open), isolation(leakage/short), and other special characteristics ( ,impedance, hipot, capacitance, current carrying capacity,etc.) that will satisfactorily evaluate the critical electricalcharacteristics of specific printed boards. The testing levelslisted in this document define some of these PurposeElectrical testing verifies that the printednetworks on the boards are interconnected according todesign test does not ensure that the board can beassembled or that the board meets all of the customer srequirements.

7 Many physical characteristics of the conduc-tors (dimensional accuracy, solder mask, conductor geom-etry and nomenclature registration, presence of holes, etc.)can t be determined by electrical test. Other checks shouldbe employed to confirm these IntroductionElectrical testing of unpopulatedprinted boards ensures that the board conforms to the elec-trical design requirements . This specification defines differ-ent levels of test to achieve this purpose. The user and sup-plier will be responsible to define the testing levelnecessary for each individual part testing requires both initial capital investments aswell as ongoing recurrent costs.

8 Initially, electrical testingrequires an investment in properly trained personnel, hard-ware, and software. Higher levels of test require moreresources and investment. Following this initial investment,handling, testing , performance diagnostics, and rework allaffect the recurring cost of electrical tests. In selecting theappropriate test level, technology, equipment, and associ-ated fixturing, a suitable compromise between productivity,features, and costs can be costs associated with electrical testing can vary dra-matically, from a few cents for fixture test probes to hun-dreds of thousands of dollars.

9 Costs alone, however, shouldnever be the only criteria for selecting an automatic testequipment (ATE) system. As shown in Figure 1-1, manyother important areas require consideration. For example,spacing and density may be of paramount importance toone user, while another may be concerned with testingIPC-9252-1-1 Figure 1-1 ATE Selection CriteriaAT EPURCHASINGCONTIGENCIESDIAGNOSTICSCOSTMA INTENANCEFAULTLOCALIZATIONFUTUREAPPLICAT IONSDENSITYCAPABILITIESDOCUMENTATIONSUPP ORTSERVICESPRODUCTTHROUGHPUTFIXTURINGPRO GRAMMINGELECTRICALPARAMETERSF ebruary 2001 IPC-92521