Adaptable, Modular Platforms Are Key to Future-Focused Test

By GO SEMI & BEYOND Staff

The electronics industry evolves continually, introducing potentially disruptive technologies and driving new applications at a pace that requires companies to respond quickly and nimbly. Being able to recognize trends early on and provide solutions that can adapt to meet emerging demands is key to remaining competitive.

This is especially true of suppliers to the semiconductor ecosystem, including test and measurement solution providers, who must be able to meet the increasingly stringent testing requirements associated with devices developed for everything from smartphones and displays to AI and automotive applications.

A dominant trend is the demand for smart portable devices such as smartphones and tablets to deliver processing performance without significantly compromising battery life. A long battery-charging interval is a huge differentiator that can make or break even the most promising products and technologies. Simply put, people demand long battery life, but still crave faster, smaller, more feature-packed devices with power-hungry connectivity technologies like 5G.

However, solving one problem often produces another. This axiom applies to developing more sophisticated devices, where testing, especially system-on-chip (SoC) testing, has come up against such daunting challenges as higher voltages, data encryption, low-leakage battery-powered designs, more complex chips, and rapid development cycles. Yet test technology providers need to continue to meet the demand for low-cost solutions in high-volume manufacturing environments. Today, the testing space is defined by a broad range of different applications, requiring a similarly large variety of test methodologies. By looking ahead, companies can position themselves early on to benefit over the course of a product’s lifecycle.

Autonomous cars and e-mobility are leading trends that are under continuous development. These applications have evolved rapidly over the past few years, with the number of electronic components in today’s vehicles having rocketed into the near-triple digits. From infotainment (car navigation, center console control) to autonomous driving (image sensors, AI) to vehicle control (driving assistance, tire pressure monitoring, engine control), this market offers phenomenal potential, both current and future. The more innovations that are developed, the more markets created and the greater the demand. Ensuring automotive-grade, zero-defect quality is essential to guaranteeing safety, reliability, and market success.

Enabling high-quality testing

Advantest has a wide portfolio of solutions with the flexibility and capabilities essential for expanding into sectors where innovation is on the rise. These solutions are all designed to contribute to improving test quality and flexibility while lowering test costs.

The V93000 system is configurable to match device needs, providing DC, digital, analog and RF capabilities on one tester platform. As testing needs change and develop over time, the platform can adapt with the addition of new modules to expand functionality. The RF solution, for example, can accommodate a wide range of devices with varying levels of complexity (such as mobile phones, navigation systems, Wi-FI- and Bluetooth-enabled devices, and IoT systems) – testing up to 32 devices or RF ports in parallel.

Complementing the platform with the power analog FVI16 card enables flexible and transparent high-quality power testing (see Figure 1). The card, which is mainly used for automotive, industrial and consumer mobile charging applications, utilizes shorter test pulses, which prevents heating up the tested device and saves test time, and features a digital feedback loop design for accurate and reliable measurements. It also houses test processor technology with 16 units per card, enabling customers to run tests in parallel, time synchronized and with high throughput.

Figure 1: The V93000- FVI16 floating power VI source for testing power is used primarily in the automotive, industrial, and e-mobility markets. (Source: Charlene Perrin)

The Wave Scale RF, MX, and MX HR channel cards are used on the same platform for multi-site and in-site testing of RF and mixed-signal devices. The cards, which each have different capabilities, bandwidths and application targets, were specifically developed to be adaptable to future device test demands.

The T2000 test platform, with air and liquid dual capability, is also available for many different applications, including IoT/module test solutions, automotive and power-management IC (PMIC) solutions (Figure 2). This single test platform can cover all segments, including mobile charging technologies, automotive applications-specific standard products (ASSPs), and battery monitoring. It features high parallelism and multi-site test technology for measuring devices under test (DUTs). The platforms benefits, in addition to reducing test costs and time to market, include providing consistent quality and traceability.

Figure 2: The flexible T2000 test platform performs high-volume, parallel testing of a wide range of SoC devices. (Source: Advantest)

Primarily focused on the automotive and consumer markets, Advantest’s SoC pick-and-place handling systems handle fine-pitch devices while applying precise temperatures. The M4841 system features individual thermal accuracy with high reliability, contact force and throughput. It can operate across a wide temperature range, with very low jam rates. The M4872 has active thermal control with a vision alignment option and fast temperature boost. It also has high contact accuracy and high-power dissipation, to help optimize yield. This system provides failure detection for applications that demand the highest quality.

As technologies evolve into more demanding and complex systems with higher performance capabilities, the future of semiconductor testers will require ongoing development. Advantest is one company that intends to grow along with these and other future innovations, adhering to its strategy of keeping test costs low while delivering high-quality, reliable testing solutions.

Parallelism Reduces Cost of Test for IoT, 4G, 5G, and Beyond

By Dieter Ohnesorge, Product Manager for RF Solutions

Introduction

The proliferation of the Internet of Things and the move from 4G to 5G is bringing about pressing test problems. The challenges will increase as billions of IoT devices incorporate GPS, Bluetooth, WLAN, NB-IoT, LTE-A, LTE-M, and other connectivity technologies and as smartphones begin connecting with 5G networks. Applications extend from M2M communications to fixed and mobile wireless access in smart cities. Venues for deployment will extend from factories and vehicles to stadiums and airports.

Transceiver chips for such applications include an increasing number of bands and RF ports carrying high-quality signals. The result can be longer test times leading to increasing cost of test.

Parallel test flow

Many transceivers have architectures that support testing paths and bands in parallel to reduce the cost of test with test techniques that are closer to mission mode, with the test mimicking real-life operation. For example, while you are making a phone call in your car, your smartphone is connected to a cell tower but also to your hands-free Bluetooth connection. You are also likely navigating by GPS and may use a WLAN connection to download a video for your kids to watch. All these functions are taking place in parallel, and an effective production-test strategy should come as close as possible to applying these mission-mode parallel operations.

Traditional “serial” test-flow techniques, based on a fanout RF architecture with shared stimulus and measurement resources, cannot cost-effectively test complex devices. For an LTE-A transceiver with carrier aggregation, a serial test approach would need to test the various uplink and downlink channels sequentially in a series of RF stimulus and baseband measurement operations followed by baseband stimulus and RF measurement operations—leading to long test times.

An alternative is the parallel test flow, enabled by an architecture incorporating independent RF subsystems with truly parallel stimulus and measurement ports. A parallel test flow can speed the test of multiple ports in a single device and can also support multisite test.

WSRF LTE-A/RF combo device test example

The parallel test technique is enabled by instruments such as the V93000 Wave Scale RF (WSRF) card, which offers test-processor-based synchronization and parallel mission-mode test capability. WSRF can simultaneously test multiple transceiver channels in parallel, thereby improving multisite efficiency (MSE) and significantly reducing test time.

The WSRF includes four independent RF subsystems on each card, with 32 truly parallel stimulus and measurement RF ports per card. Each RF subsystem includes an embedded arbitrary waveform generator and digitizer. The WSRF supports 16x multisite test with native ATE resources and includes embedded RF calibration standards.

For less demanding IoT applications, the WSRF scales down to one RF subsystem for use in an A-Class V93000 system. The WSRF can scale down for IoT, enabling it to perform quad-site testing based on one-fourth of a card using just one RF subsystem. At the other end of the spectrum, you may need four WSRF cards to cover the different needs for both sub-6-GHz and mmWave frequencies.

A concept study involving an LTE-A RF transceiver/RF combo device with 802.11ac support and a 3G/4G front-end module showed that the WSRF resulted in test-time improvements of up to 50% as compared with the PSRF, the predecessor to the WSRF.

Figure 1 (not to scale) depicts receive-channel, transmit-channel, and other tests performed serially (top) and the same tests using a mission-mode parallel technique (bottom). Parallel mission-mode test coupled with test-processor-based synchronization can provide a 40% to 60% test-time reduction. Figure 2 provides specific test-time-reduction values for testing parameters such as gain and EVM in single- and quad-site formats, showing MSE and test-time improvement. The results are based on similar setups and sample rates, with the patterns used being the same.

Figure 1. A serial test technique (top) cannot cost-effectively test complex devices, whereas a parallel mission-mode test (bottom) can result in a 50% test-time reduction.

Figure 2. This overview shows multisite efficiencies (MSE) and test-time improvements for parallel vs. serial receiver tests.

Testing 802.11ax

Test of 802.11ax devices offers another example of the benefits of parallel test flow. The successor to 802.11ac, 802.11ax offers an expected fourfold increase in user throughput. Designed to improve overall spectral efficiency in dense deployment scenarios, 802.11ax incorporates multiuser MIMO on the downlink and uplink. It operates in both the 2.4-GHz and 5-GHz ISM bands.

These characteristics impose significant ATE challenges. Multiuser MIMO places more demands on RF/analog resources, resulting in longer test times. ATE RF and baseband instruments (AWGs and digitizers) must accommodate the standard’s 160-MHz bandwidth, and the 1024 QAM modulation scheme demands improved phase noise and linearity.

An eight-site test of an 802.11ax transceiver operating in the 5-GHz band with 4×4 MIMO demonstrates how Wave Scale technology and SmarTest 8 software can test over 4,000 test items, including transmitter, receiver, power-detection, DC, and functional test parameters. The Wave Scale technology includes the Wave Scale RF plus the Wave Scale MX, which includes 16 AWGs, 16 digitizers, 64 PMUs, a hardware sequencer, a real-time signal-processing unit, and a large waveform memory.

Complementing the Wave Scale cards, SmarTest 8 protocol-aware software works directly with user-defined register files and generates a protocol-aware sequence using device-setup APIs with no additional conversion required. The software supports the easy-to-implement flexibleA-Class parallel programming required for concurrent testing. An automated bursting capability works with any type of test, including DC, RF, and digital, and runs as fast as tests based on flat patterns, eliminating the need for manual test-time-reduction efforts, thereby providing an early throughput advantage.

In the 802.11ax example, the Wave Scale instruments powered by SmarTest 8 can test four transmitters concurrently in about 23 ms, vs. 80 ms for a serial-measurement approach, resulting in a test-time reduction of about 70%.

Moving to 5G

5G chips are appearing on the market and can be expected to find their way into 5G handsets and infrastructure equipment in the coming months as 5G deployments roll out. Such devices will increasingly need to rely on parallel test flows to handle the complexities of 5G while continuing to provide backwards compatibility with 3G and 4G technologies, and as they continue to support WLAN, GPS, ZigBee, Bluetooth, and various IoT connectivity applications.

With respect to 5G, new smartphones and other devices will achieve high peak speeds, and 5G will rely heavily on eMBB (enhanced mobile broadband). eMBB will provide not only improved data rates but also broadband everywhere, including in vehicles extending to high-speed trains. Coupled with carrier aggregation, eMBB provides a further example of the benefit for having a parallel test flow that goes hand in hand with test-time reduction and lower COT.

The Wave Scale cards, available now, stand ready to help customers keep pace with the parallel test demands of current and next-generation semiconductor devices.