Case Study: Automated Semiconductor Characterization and Validation
• A test system that can automatically characterize an integrated circuit under varying conditions • Engineering Challenge: synchronize multiple instruments and maintain very tight timing and triggering
Enabling Technologies
• Precision DC instrumentation
• Measurement of voltage, current, resistance, and other factors
Characterizing a Solar Cell’s Performance
IC Characterization System
• The system contains a mix of digital and analog instruments for control and measurement including:
• 100 MHz frequency generators to triggers and synchronizes other devices and provide a common base clock. • A 100 MS/s arbitrary waveform generator • A high‐speed digital I/O module to output a modulated digital pattern to the chip
• Measure Voltage and Current Ratings (VOC and ISC)
• Maximum Current, Isc occurs when the load is a short • Maximum Voltage, VOC occurs when the load is open
• Lower the production cost of solar cells
• Increase automation for more efficient manufacturing with less scrap
Agenda
• Solar Energy Fundamentals • Automated Test
• Key advantages of this implementation
• Integration of the analog and digital instruments in one system • Very tight control over timing, minimizing jitter • Software flexibility to adapt to each IC’s control requirements
• System Automation and Control
• PV semiconductor process control and monitoring • PV power plant electrical monitoring and sun tracking control
Availability
• • • • • +/‐ 20V, 2A isolated output 10nA /100uV source resolution 5 current ranges – 2A to 200uA 4‐quadrant operation – up to 10W Sink Remote sense capability SMU Channel Quadrant Diagram
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ρ=2πLp(V/I)
Measurement Hardware
• Source Measure Unit (SMU) • Sources both positive & negative currents, then measures the resulting voltage • Also used to sink (or dissipate) current when testing output short circuit currents and leakage currents • NI PXI‐4130 Power SMU
Case Study: GigaMat Technologies
• Perform automated semiconductor wafer sorting based upon physical and electrical characteristics • Meet or exceed the precision and repeatability of industry standard equipment but with greater throughput, flexibility and user friendliness, and at much lower cost
Automated Test System Automation & Control
Case Studies: Solar Power
Agenda
• Solar Energy Fundamentals • Automated Test
• Photovoltaic (PV) cell I‐V characterization
GigaMat Sorting System
• NI LabVIEW is used to synchronize motion, vision, and instrumentation • This project wouldn’t have been economically viable without LabVIEW and NI synchronized motion, vision, and DAQ products. Edmond
• Calculate Efficiency
Maximum Power (PMAX)
• Power = 0 at Isc and VOC • Power reaches maximum at VMP and IMP
Fill Factor
• Main measure of cell quality • Compare maximum power (PMAX) to theoretical maximum power (PT) based on Isc and Voc
• With a solar cell efficiency of 20 percent, an area the size of Texas could supply the entire world’s energy demands [1].
The black dots represent the land area required to replace the total primary energy supply with electricity from solar cells.
US Photovoltaic Shipments, 1997-2006
*Courtesy US Energy Information Administration
Solar Power Generation Technologies
• Photovoltaic (PV) solar cells
• Solar thermal collectors
o ovoltaic (PV) cell I‐V charace t rization • Pht
• System Automation and Control
• PV semiconductor process control and monitoring • PV power plant electrical monitoring and sun tracking control
Efficiency (η)
• Ratio of output power (POUT) to Input Power (PIN) • For maximum efficiency, POUT = PMAX • PIN is the product of irradiance (W/m2) and the area of the cell (m2)
Demo – Solar Cell Characterization
• 4‐quadrant IV tracing • LabVIEW analysis and display
Agenda
• Solar Energy Fundamentals • Automated Test
• Photovoltaic (PV) cell I‐V characterization
Industry Challenges for Solar Power
• Design more efficient solar cells
• Increasing the amount of power per area (watt/m2) through better design and testing • Increase the economic viability of new technologies, such as solar tracking to increase solar cell output
Pout Pin