NAND Flash Card Low Cost Test Strategy Development And Implementation

Integrated circuit testing is an important part in integrated circuitindustry, it acrosses the whole process of chip design、manufacture、assembly、application. Test cost takes big ratio in chip cost, how to reducetest cost is the emphasis of chip manufactures、design and test workershave been considering all the time.In intergrated circuit product nowadays, flash and flash card takedefinite mark ratio. Test mothod and test equipment of flash and flash cardare also the focus which people pay attention to. This thesis develops andimplements NAND flash card low cost test strategy for NAND flash cardlow cost test requirements. The strategy mainly develops and implementslow cost NAND flash cardATE hardware and software.In the strategy, use the following ways to improve test speed andstability.1、 Use special resource architecture,16units parallel test, save testtime.2、 Use PCIe to transmit function test signals and data, design PCIeadapters、PCIe switches、PCIe cables to improve the speed and stabilityof transmitting test signals and data.3、 Test mother board has symmetrical structure, includes two logicboards. One logic board includes8duts, one test mother board includes16duts，improves the speed and stability of transmitting test signals anddata.4、 Controller PC and client PC have steady configuration system,two hard disks use Raid0mode to improve the speed of transmitting data.5、 Use GPIB mode to replace RS232mode for the communication between handler and tester, avoid the interruption in transmitting signalsand data in communication, improve the speed and stability of transmittingtest signals and data.6、 Use more threads in test program to save test time.The main work finished in this thesis is as follows.1、 Analyze flash and flash card’s structure、capacity、workprinciple、test process and so on.2、 NAND flash card low cost test strategy design method and testsystem architecture design.3、 Hardware selection、development、implementation, softwaredevelopment、debugging、optimization.4、 Low cost NAND flash cardATE hardware cost accounting.5、 Intergrated debugging and maintenance in mass production aftersystem development finish.6、 Test result analysis.7、 Low cost NAND flash cardATE compares with other NANDflash cardATE in cost.NAND flash card low cost test strategy has been applied in massproduction, solved some problems which test system is unstable、test timeis longer than normal test time、partial product yields are not qualifiedand so on, improves test stability, achieves the goal of testing NAND Flashcard with low cost. Low cost NAND flash card ATE compares with otherNAND flash card ATE in machine’s depreciation cost、 machine’smaintenance cost、machine’s output、single NAND flash card’s test cost,demonstrates the advantages of low cost NAND flash cardATE.According to the inspection in mass production, NAND flash cardlow cost test strategy reduces test cost, improves production efficiency, cansatisfy test requirements of product, creates economic benefits, strengthensthe competitiveness of enterprises, provides an effective strategy forNAND flash card low cost test, has application value and practice significance.