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Figure 2 is a simplified block diagram of a system for testing a single LED. For automation purposes, a PC and a component handler—a probe station for on-wafer measurements—are typically included.

图2是测试单个LED的测试系统简化模块图。对于自动化测试，通常包含一台PC和一个元件机械手——晶圆级测量[1]需要一个探针台。

Figure 2. Block diagram of a SourceMeter-based single LED test system.

图2. 基于数字源表的单LED测试系统模块图

元件机械手、测试夹具、分拣器、数字线（DIO）、2602A[2]通道A 2602A通道B

In this test configuration, the main purpose of the PC is to store measurement data in a database for documentation. A secondary purpose is to reconfigure the test sequence for different parts. Series 2600A instruments are unique in terms of their independence from the PC controller. The TSP embedded in each supports writing a complete test plan that operates on the instrument itself. In other words, it’s possible to write a complete PASS/ FAIL test sequence script and run it from the instrument’s front panel without instrument reprogramming.

在这个测试结构中，PC机的主要作用是将测量数据保存在数据库中用于资料记录。第二个作用是针对不同的部件重新配置测试序列。2600A系列[3]的独特之处在于它们能够独立于PC控制器单独工作。每台仪器上内嵌的TSP支持用户编写能够在仪器本身上执行的完整测试规划。换句话说，用户可以编写完整的PASS/FAIL测试序列脚本[4]，无需仪器重编程即可通过仪器面板运行它。

A production test system is likely to incorporate a component handler to transport the individual LEDs to a test fixture, where they can be electrically contacted. The fixture is shielded from ambient light and houses a photodetector (PD) for light measurements. In the setup illustrated in Figure 2, a single Model 2602A Dual-Channel System SourceMeter instrument is used for both connections. Here, Source-Measure Unit A (SMUA) supplies the test signal to the LED and measures its electrical response while SMUB monitors the photodiode during optical measurements.

生产测试系统可以利用元件机械手将单个LED传送到测试夹具上，进行电气接触。该夹具屏蔽了环境光，并且安装了光电探测器（PD）进行光学测量。在如图2所示的配置中，使用了一台2602A型双通道数字源表[5]实现两种连接。其中，源测量单元A（SMUA）为LED提供测试信号并测量其电响应，而SMUB在光学测量过程中用于监测光电二极管。

The test sequence is programmed to begin using a digital line from the component handler that serves as a “start of test” (SOT) signal. After the SourceMeter instrument detects the SOT signal, the tests for characterization of the LED begin.

测试序列在编程开始时利用元件机械手的一条数字线作为“测试启动（SOT）[6]”信号。当数字源表检测到这个SOT信号后，LED特征分析测试就开始了。

After all electrical and optical tests are completed, a digital line to flag “measurement complete” is set for the component handler. In addition, the instrument’s built-in intelligence performs all pass/fail operations and sends a digital command through the digital I/O port on the instrument to the component handler to bin the LED based on the pass/fail criteria. Then, two actions can be programmed to take place simultaneously: data is transferred to the PC for statistical process control and a new DUT moves into the test fixture.

在所有的电气和光学测试都完成之后，系统为元件机械手设置一条标志“测量完成”的数字线。此外，仪器本身的智能功能执行所有的pass/fail操作，通过仪器上的数字I/O端口向元件机械手发送一条数字命令，根据pass/fail判据对LED进行分拣。然后，可以设定两个操作同时执行：将数据传输到PC进行统计过程控制，同时将一个新的DUT[7]传送到测试夹具上。

[1] 晶圆级测量：http://www.keithley.com.cn/semi/acs

[2] 2602A http://www.keithley.com.cn/products/semiconductor/sourcemeasureunits/series2600sys/?mn=2602A

[3] 2600A系列：http://www.keithley.com.cn/products/semiconductor/sourcemeasureunits/series2600sys/?mn=2600A

[4] 脚本：http://www.keithley.com.cn/events/proddemos/newdemofolder/TSP.html

[5] 2602A型数字源表：http://www.keithley.com.cn/products/semiconductor/sourcemeasureunits/series2600sys/?path=2602A/Documents

[6] SOT：http://www.keithley.com.cn/products/localizedproducts/currentvoltage/2499digio

[7] DUT: http://www.keithley.com.cn/events/proddemos/27xxdemo/demoimages/PD1_DUT.jpg/view