Electronic Test

The SPPDG electronics research and development test laboratory is a diverse facility with state of the art test and evaluation capabilities. With a primary focus on high clock rate digital circuits and systems, the capabilities are in place to characterize materials, discrete passive and active components, integrated circuits (ICs), multichip modules (MCM's), printed circuit boards (PCB's), and complete prototype digital processor systems. We have also been working for the past five years to strengthen a capability to evaluate high frequency analog electronic devices and systems, as well as optical components and subsystems, and microelectromechanical system (MEMS) devices as well. The SPPDG test laboratory is installed in an eight-bay, 3000 square foot, Class 1000 clean room (Figures ET-1 and ET-2), which is sufficiently clean that bare wafers and integrated circuits can be tested "in the open" for long periods without significant contamination by airborne particles. General test capabilities and supporting instrumentation have been grouped into the following selected areas:

Figure ET-1
Typical Test Suite

Figure ET-2
Typical Test Suite

Interconnect, Passive Device and Material Characterization.

This capability exists to characterize signal interconnects of many different types, including transmission lines on multichip modules or printed circuit boards, integrated circuit connections, and any type of connections to or from a device (Figure ET-3). New dielectric materials such as ferroelectrics have been characterized, along with many types of discrete and embedded integral passive electrical components. These investigations are performed with a broad range of test instrumentation, with each instrument listed in order of increasing frequency capability

• Kelvin micro-ohmmeter {DC},
• Low frequency inductance/capacitance/resistance meter {LCR} {40 Hz-130 MHz},
• Capacitance-voltage (CV) meter {1 MHz}
• Mid-frequency LCR {75 KHz-30 MHz},
• RF impedance analyzer {1 MHz-1 GHz},
• Low frequency network analysis {300 KHz-1.8 GHz}
• High frequency network analyzer {45 MHz-110 GHz; soon to be extended to 220 GHz}
• Single ended and differential time domain reflectometry (TDR) and transmission (TDT) {35 psec edge rate}

Figure ET-3
High Frequency Probing of Passive Structures

Integrated Circuit, Multichip Module, Printed Circuit Board and System Oriented Active Characterization.

This category of testing requires equipment that is capable of generating signals to be applied to the device under test (DUT), and acquiring output signals from the DUT. Our test equipment for these tasks includes a full range of measurement capabilities, ranging from DC up to 50 GHz frequencies (Figure ET-4), including bit error rate testing (BERT) up to 20 GHz; and a network analysis capability up to 110 GHz (Figures ET-5 and ET-6). Listed in order of increasing frequency performance are the following instruments.

• Semiconductor parameter analyzer {DC}
• LF logic analyzers {50-100 MHz generation and acquisition}
• HF logic analyzers {1 GHz acquisition}
• Noise figure meter {10 Hz-2 GHz}
• Digital pattern and pulse generators {50 MHz-3 GHz}
• Bit error rate instrumentation {100 KHz-20 GHz}
• Microwave counters {10 Hz-18 GHz}
• Spectrum analyzers {100 Hz-22 GHz}
• Microwave power meter {100 KHz-26 GHz}
• Noise Analysis System from Agilent and ATN Microwave {45 MHz-26.5 GHz}
• Real time oscilloscopes {1 GHz}
• Sampling oscilloscopes {up to 50 GHz}.

Figure ET-4
High Frequency Probing of Active Structures

Probing, Fixturing, Interfacing Capability.

In order to verify proper device operation and characterization, a method must exist to interface the test equipment to the actual device to be tested. This interface capability must support a large number of signals, as well as signals exhibiting high frequency and/or wide bandwidth characteristics. Much of our work is performed using advanced microprobing techniques for probing fine geometries at the IC die and MCM substrate level (Figure ET-7). The test facility has more than a dozen probe stations featuring both manual and automated micro-positioning, optical and digital imaging, vibration-free air tables, and modularity for customizing the test setup for a variety of applications. Included are a large variety of wide bandwidth microwave probes (some probes exhibit upper frequencies of 40 GHz, while others exhibit upper frequencies of 110 GHz), high impedance shielded probes, membrane probes, and high I/O count needle probes. Specialty test fixtures and test sockets have been developed for package device applications (Figure ET-8).

Figure ET-7
Test Fixture for Single,
Flip Chip Mounted Integrated Circuit

Figure ET-8
Test Fixture for High I/O
Count MultiChip Module

Automation, Archival Data Storage, and Quality Control.

Many of the tests that are performed in the Mayo SPPDG laboratory have both near term and long term value. Of critical importance is that all measurements be documented well enough that they can be repeated and verified, and also retrieved and understood many years after the tests have been completed. Specialty programs have been written to acquire the data automatically from a large number of instruments, along with instrument parameters and operator/date/time stamp information (Figure ET-9).

Figure ET-9
Example of Raw Measurement
Data Stored for Future Reference

All measurement data is stored with accompanying descriptive text, which clearly identifies the device under test, the type of test conducted, and the test conditions. Text and data from these measurements are stored in a well ordered directory structure. This complete set of information is backed up and archived. The quality of the measurements is assured through the use of verification structures incorporated directly into many of the designs, along with "gold standard" verification components that are tracked over time (Figure ET-10). Virtually all equipment is calibrated in-house on a yearly basis, with full National Institute of Standards and Technology (NIST) traceability.

Figure ET-10
Example of Raw Measurement
Verification Sites

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Page modified: January 22, 2002

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