IC Semi-automatic Test System Based on ADLINK

China's consumer electronics industry is developing rapidly, and with it comes the rise of the semiconductor processing industry in the country. Places such as Shanghai, Shenzhen, Suzhou, and Beijing have formed semiconductor production and processing bases of considerable scale (Reference 1).

Having a strong reserve fund is the first condition for establishing a semiconductor company. From research and development to production and manufacturing, many links often require "a huge amount of money". Just to establish a standardized packaging and testing plant requires an investment of hundreds of millions of dollars. Many companies specializing in outsourcing services have solved this problem. They are responsible for everything from wafer generation to product testing. Semiconductor companies only need to pay for outsourcing services.

However, some testing work with high confidentiality requirements still needs to be completed by semiconductor companies themselves. Establishing a traditional IC test system is very expensive and very difficult for semiconductor companies that are still in the development stage. Based on ADLINK industrial computers , this paper designs a semi-automatic IC test solution to achieve low-cost, high-precision, and easy-to-maintain small-batch IC testing.

System hardware composition

Figure 1 shows the system hardware structure diagram of the test platform. The platform mainly consists of the following parts.

ADLINK Industrial Computer

The core control unit of the platform uses ADLINK Industrial Computer, which adopts PXI (PCI eXtensions for Instrumentation) bus.

PXI bus is a modular instrument platform designed for measurement and automatic control applications. With PXI, customers

Modules can be selected from multiple suppliers and integrated into a PXI system. The communication between PXI bus modules adopts widely used PC-based technology, such as the 132MB/s PCI bus, which ensures high-performance communication while ensuring widely available software. PXI also integrates clock and synchronization signals into the system, so users can transmit accurate signals between devices without additional wiring (Reference 2).

In this test platform, each functional module of ADLINK computer is integrated into the PXIS-2700 industrial-grade chassis. It can connect 3U PXI and CompactPCI modules, with 1 system slot and 17 PXI/CompactPCI peripheral card slots. The integrated functional modules are:

PXI-3800 module: PXI-3800 is a truly all-in-one industrial computer controller, using Pentium M processor , FSB400/533MHz, CPU main frequency can reach 2.0GHz (support future Dothan CPU ); it also has dual 200-pin DDR SO-DIMM slots, supporting up to 2GB RAM; its dual CompactFlash interface is used to replace HDD and FDD; CF2 supports hot-swappable CF card function; in addition, it has dual USB2.0 interfaces, dual serial ports (RS-232/422/485) and single parallel port, standard VGA output and Ethernet interface. These configurations provide reliable guarantees for high-performance testing.

SMX-2042 module SMX-2042 is a 64-channel 16-bit 250kS/s multi-function DAQ module, which can be used as a flexible fully automatic range digital multimeter. It can not only measure DC, AC voltage, current and 2-wire and 4-wire resistance, but also directly measure inductance and capacitance. The measuring frequency is up to 1000rps and the counter frequency is from 2Hz to 300kHz. In addition, it also has a self-calibration function and 300V isolation protection.

CPCI-6208 module CPCI-6208 integrates 16-bit D/A, with 8-channel voltage output and 8-channel current output, as well as 4-channel TTL digital input and 4-channel TTL digital output. [page]

CPCI-7434 module CPCI-7434 module is a 64-channel isolated digital output module, which is used to drive the relay matrix module.

TE-5201 module TE-5201 is a 100MS/s arbitrary waveform generator with 10-bit time resolution, multi-device synchronization function, 2MS storage depth and ultra-high-speed waveform download using DMA. It is used as a signal source in semiconductor device AC measurement (Reference 3).

Relay Matrix

The relay matrix is ​​the interface between the low-power control unit and the high-power execution unit. This system can be configured with up to 64 relays (determined by SMX2042). Since the driving current of the relay is large, the output signal of PXI-6509 needs to be amplified by a triode or MOS tube.

功放\'); companyAdEvent.show(this,\'companyAdDiv\',[5,18])"> Power amplifier module

Since the output signal of CPCI-6208 is a weak current signal, it cannot be used as a voltage or current source for a power-type device under test. The power amplifier module can amplify the output signal of CPCI-6208 . It is mainly composed of 8 power 运放\'); companyAdEvent.show(this,\'companyAdDiv\',[5,18])"> amplifiers OP A548 produced by TI.

Socket and signal acquisition and amplification circuit

Usually, chip testing involves placing the device under test into the socket of the corresponding chip package, and then fixing the socket to the test board by welding or clamping.

Strictly speaking, signal acquisition is not used for signal acquisition, but for data transmission. For some high-power signals and weak signals, the selection of sockets and the design of peripheral circuits are very critical, which may be the main source of system errors.

High and low temperature system

In order to measure the temperature range of the chip, a high and low temperature system is needed to simulate the ambient temperature of the chip.

System software structure

The software structure of the system is shown in Figure 2. PXI-3800 supports Windows XP system. Labview is a graphical development environment with built-in signal acquisition, measurement analysis and data display functions. It abandons the complexity of traditional development tools and provides users with powerful functions while ensuring system flexibility. Labview integrates a wide range of data acquisition, analysis and display functions in the same environment. We can seamlessly integrate a complete set of application solutions on the platform. ADLINK Industrial Computer not only supports the Labview graphical development environment, but also provides Labview controls that are closely related to various boards . Developers only need to call these controls to easily write test software. [page]

In addition, the FTS device has an embedded system inside, and developers can only exchange information with it by sending and receiving ASCII code instructions, so a serial communication program needs to be written.

System workflow

The system workflow is described in Figure 3.

After the operator starts the system, the system starts self-checking. If a fault is found, the system resets and automatically powers off. First, each functional module is initialized. Next, the upper computer PXI-3800 sends action instructions to each lower computer. After receiving the instruction, the CPCI-7434 module outputs the corresponding level signal to control the relay to complete the switching of the signal transmission channel in the test circuit. The CPCI-6208 module outputs the corresponding analog signal, which is amplified by the power amplifier module as the voltage source and current source required by the test circuit. At the same time, SMX - 2042 performs the corresponding test action. If necessary, the high and low temperature system will provide the corresponding ambient temperature. After a certain delay, the system starts to collect data, including the test results of SMX-2042 and the actual ambient temperature of the chip fed back by the temperature sensor . The collected data is displayed in real time to the output terminal and saved in the non-volatile memory. At this time, the system will automatically check whether there are instructions to be executed. If so, it will enter the next cycle. Otherwise, the system

System reset and end.

Analysis of system advantages and disadvantages

Advantages:
1. Low cost. Usually, it only costs about 300,000 RMB to build a standard test system, and the cost advantage is very obvious.
2. High test accuracy. Relying on auxiliary circuits, its test accuracy can reach: voltage mV level, current nA level, resistance mΩ level, meeting the test accuracy requirements of most current products.
3. Easy to develop, maintain and upgrade. Since Linghua Computer has provided powerful data acquisition and processing modules, the hardware design of the test system is greatly simplified. In addition, the system uses the Labview graphical development environment, and designers can write efficient test programs without programming experience. The system uses the PXI industrial bus, which can be easily upgraded by users.

Disadvantages:
1. The test speed is low and is not suitable for large-scale testing. Since the system is not equipped with a mechanized feeding mechanism, but adopts the manual feeding method of the operator, the anti-static protection and operation skills of the operator are required to be high, and the test time is relatively long. The Labview software compilation environment is also one of the reasons that affect the test time. Compared with the program written in Visual C++, the execution time is much longer.
2. Poor anti-interference ability. Since the system is not highly integrated, some circuits lack shielding protection. Interference signals, especially noise, are likely to become the main source of system errors. Therefore, it is very important to take effective anti-interference measures.

This article uses ADLINK industrial computers to build an IC semi-automatic test platform, which can perform small-batch tests on most current semiconductor products. Compared with traditional test systems, it greatly reduces costs and ensures product test accuracy. In addition, it has the advantages of simple maintenance and easy upgrades, providing a reliable design basis for IC test developers.

References
[1] "2005-2006 China Integrated Circuit Industry Research Report", Shuiqing Muhua Research Center, 2006.8
[2] Zhuang Jiaming, "PXI - Industrial Standard Platform for Manufacturing Test", Chroma Electronics, 2003.12
[3] PXI Selection Guide, ADLINK