晶圆上测试射频系统级芯片的挑战(英文)

Measurement Challenges for On-Wafer RF-SOC Test

随着无线通讯产业推动芯片集成度的不断提高,系统级封装(SIP)和多芯片组件(MCM)被更多采用,射频系统级芯片(RF-SOC)器件的良品测试已成为一大挑战。这些器件与传统的单晶片集成电路相比,具有更高的封装成本,并且由于采用多个晶片,成品率较低。其结果是进行晶圆上综合测试的成本远超过最终封装后测试器件的成本。此外,一些IC制造商销售裸晶片以用于另一些制造商的SIP和MCM中,这就要求发货的产品必须是良品。以蓝牙射频调制解调芯片为例,讨论了RF-SOC器件良品晶片(KGD)的测试难点和注意事项。对此样品,除了在晶圆上进行射频功能测试的难点,还有同时发射和测量数字、射频信号的综合问题。此外对被测器件(DUT)用印制线路板布线的难点,包括晶圆探针卡的设置及装配进行探讨。还介绍了选择探针测试台、射频晶圆探针卡和自动测试设备(ATE)时需考虑的因素。并以晶圆上测试的系统校正,包括难点和测试方法,作为结尾。这颗蓝牙射频调制解调芯片的实际测试数据也会被引用,以佐证和加深文章中的讨论。

With the wireless industry pushing towards higher levels of integration,employing more sys-tem-in-a-pack age(SIP)and multi-chip modules(MCM),known-good-die testing of RF-SOC devices has emerged as an im portant test challenge.These devices have higher packaging costs compared to the tradi tional sin gle die integrated cir cuits(ICs),and potential lower yields,since multiple dice are used.As a re sult,the cost to perform comprehen sive on-wafer testing is out weighed by the cost to scrap the de-vices during the final package test.In addition,some IC man ufacturers are selling bare die to be used inin the SIP or MCM of another manufacturer.On-wafer test is then required to ensure that good product is shipped. This paper will use a Bluetooth radio modem chip as anexample to discuss the measurement chal-lenges and considerations for known-good die(KGD)testing of an RF-SOC device.With this example,the difficulty of testing RF functionality on-wafer will be compounded by the need to source and measure RF and digital signals simultaneously,creating signal integrity issues.This paper will explore the chal-lenges of laying out the printed circuit board for the device under test(DUT),including setup of the waferprobe card and assembly.Factors taken into account when selecting a probe station,RF wafer probecard,and ATE test system will then be discussed.This paper will conclude with a discussion of on-wafercalibration,including challenges and solutions.Actual results from a Bluetooth radio modem chip will be used to further the discussion.