ict測(cè)試原理及程式簡(jiǎn)介(已改無錯(cuò)字)
2023-05-30 04:57:26 本頁面
【正文】 s Test (Bad Board) Testing For Shorts 100mV 100 W “ A” “ B” “ C” “ D” “ E” “ F” “ G” ? Which node is shorted to node C? A short has been detected from node C to one of the remaining nodes D, E, F or G Node C is not shorted to nodes D and E Node C is shorted to either nodes F or G Node C may be shorted to node G This is not assumed! Node C is shorted to node G 假象短路的調(diào)試 ? 假象短路出現(xiàn)的原因是特定的節(jié)點(diǎn)的測(cè)試順序造成誤判 ,必須在程序發(fā)布前排除 ? 方法是將出錯(cuò)的節(jié)點(diǎn)（或者節(jié)點(diǎn)群）挪到被短路的節(jié)點(diǎn) (或節(jié)點(diǎn)群）后面。這個(gè)過程在調(diào)試中可能要重復(fù)幾次 ,挪動(dòng)時(shí)最好在同一個(gè) threshold設(shè)置群之內(nèi) . ? 可以自己設(shè)置 threshold，但是要遵循 threshold值從大到小的順序 , Threshold最低盡量不要設(shè)到 4以下，尤其是電源點(diǎn)。否則會(huì)有漏掉真正短路的可能 . ? 不要輕易把節(jié)點(diǎn)放到測(cè)試文件的末尾，這樣可能造成開短路 覆蓋率的缺失，尤其是電源點(diǎn)或者 VCC這類本身就是低阻抗的節(jié)點(diǎn) . ? 調(diào)試時(shí) settling delay可以加的比較大，在優(yōu)化時(shí)再減小 Shorts Test Report Options report mon devices report limit 12 Short 1 From: D3 22044 To: D4 21938 Common Devices: U1 U4 report list, mon devices report limit 12 Short 1 From: D3 22044 To: D4 21938 Common Devices: u1 u4 report phantoms Short 1 From: D3 22044 To: D4 21938 Part 5 ? Analog Test ? capacitors ? connectors ? diodes ? FETs ? fuses ? inductors ? jumpers ? resistors ? switches ? transistors ? zeners Part 6 Testjet amp。 VTEP amp。 iVTEP The VTEP/iVTEP/TestJet Test BGA with floating metal tops/heat spreaders are testable! PCB AC Signal Ground VTEP Sensor plate C measured Electronics board (Amplifier) To Multiplex Card Metal BGA UnderTest Floating Metal Top TestJet測(cè)試能力的極限值為 20fF， VTEP測(cè)試能力的極限值為 5fF。 低于 5的值使用 iVTEP來進(jìn)行測(cè)試，但是 iVTEP的測(cè)試速度比較慢，而且不能用來測(cè)試連接器。 Bar = Num Pins in Range 0 5 10 15 20 25 30 0 to 5 5 to 10 10 to 15 15 to 20 20 to 25 25 to 30 30 to 35 35 to 40 40 to 45 45 to 50 TestJet limit Measurement (in fF) VTEP limit mm pitch 593 Solder Balls pitch 1202 SB TestJET和 VTEP的測(cè)試界限 Aug, 2022 The VTEP/TestJet Verification The TestJet Test default threshold low 20 high 10000 device “u1” test pins 1 test pins 2, 3 test pins 4, 5, 6 ! test pins 7 ! Ground pins mented by IPG test pins 8 … test pins 13 ! test pins 14 ! Fixed pins mented by IPG device “u2” bottom。 test pins 1 test pins 2 .
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