The Problem of IC Counterfeits
IC counterfeits come from all around the world and consolidated by various electronics distributors. For many manufacturers, there is a concern some of these devices are not the best quality and may have been used before in the past, have altered specifications, or maybe complete fakes. For distributors, there is pressure to take measures to find these counterfeits and remove them. The process is IC counterfeit detection.
Checking the quality of your IC stock is not only possible but necessary to maintain quality standards and build good relationships with your customers.
There is a wide spectrum of possibilities that could make a device counterfeit. However, like counterfeit dollar bills, there are good fakes and bad fakes. It’s not hard to spot a bad fake, but there’s still a need to check your devices for counterfeits. Most counterfeits are categorized in the following:
- Complete fakes
- Rebranding/imitation/copy devices
- Rejected devices
- Reclaimed devices
- Remarked devices
IC Counterfeit Detection Methods
How can you verify the IC you bought was genuine and not a counterfeit? Test it and compare it to a known good device. There are many tests available. Some analyze the physical aspects of the device and some analyze the electrical aspects.
Physical Detection Methods
The physical test procedures are usually: X-Ray, Visual Inspection, XRF, CSAM, markings analysis, solvent test, etc. These tests do not question the electronic function of the die inside but only compare its construction features by looking for clues to counterfeiting. Most organizations doing counterfeit analysis have a good grasp of these test methods.
Electrical Test Methods
Electrical test methods are complementary to physical methods. It requires test equipment and/or test fixtures to electrically test the devices. This type of method has a range of cost and complexity that depends on your device and the purpose of the device. However, there are tradeoffs between cost, test coverage, and complexity. See the tabs below for different types of electrical test methods.
A functional test, or ATE, is a highly flexible and configurable method for a wide range of devices. It has high test coverage and its capable of replicating OEM testing for 100% test coverage. Specialized testers are available for certain categories like memory, but its resource-intensive to develop such specific test programs.
Curve tracing overcomes this limitation by not attempting to functionally test the device.
A custom bench test has limited flexibility for a narrow range of devices. It has high test coverage and its capable of replicating OEM testing for 100% test coverage. But its resource-intensive to develop specific test programs. For many vendors, bench instruments can also integrate into this test method.
The MultiTrace overcomes this by placing all resources you need into a single software-controlled box.
RTI’s manual switch boxes and DUT boards can help make bench testing easier by providing a standard and expandable means to connect to the pins under test. Use the manual switch boxes with your bench test equipment and RTI DUT boards and test sockets.
Digital signature analysis has moderate flexibility for digital devices. It has a parallel drive for all pins or serial BIST and a boundary scan or JTAG port. It has moderate test coverage and is used for specifically designed test vectors or random patterns. The cost is moderate to high with a moderate complexity level.
Curve tracing does not digitally test devices but can place inputs into a static initial condition prior to powered curve tracing or IDDQ measurements.
Analog signature analysis has good flexibility for a wide range of devices. It has moderate test coverage and finds devices with clear electrical damage. The cost is low to moderate with a low complexity level. It’s easy to learn and implement but there are fewer vendors. It is also a type of curve tracer.
RTI’s curve tracers are more flexible with respect to setting test conditions and more sensitive for lower current measurements. They are also expandable, upgradeable and can be configured for a wider range of user needs. See curve trace configurations here.
Curve tracing has excellent flexibility for a wide range of devices and can be used with any device, analog or digital and Si or GaAs technologies. It is independent of device function and is done at low voltage and low current making it safer for the device. Curve tracing can be done with as little information as just the package outline drawing. RTI is one of the leading suppliers of automated curve tracers.
What is Curve Tracing?
Curve tracing is used to measure DC characteristics of each pin of the modern electronic IC devices. Curve tracing can be used as a tool for screening devices for electrical defects like Opens, Shorts, and Leakage, but also for measuring basic parameters such as IDDQ or VOL and VOH. These characteristics must all match for the devices to pass.
RTI curve tracers are universal non-destructive electrical test equipment. They are built to characterize damage to IC structures and measure damage to electronic structures. This makes them the ideal tool to scan for variances in batches of devices that indicate a variety of possible failure modes.
Where is Curve Tracing Used?
A curve tracer is typically used in a laboratory setting to ensure the highest confidence in the parts purchased or sold. It can be used for:
- Incoming receiving and inspection for high reliability manufacturing such as aerospace or medical industries
- Part recovery operations, to screen out parts damaged by the recovery process
- Failure analysis labs for basic and root cause failure locating
- Component distributors to improve their test methods
- 3rd party component test labs who provide counterfeit part screening services
- Aerospace, military, and medical manufacturers
Who Uses Curve Tracing?
Much like where curve tracing is used, curve tracers are used by high-reliability manufacturers, distributors, part recovery providers, law enforcement, laboratory and analysis service providers for part inspection, lab testing, and failure analysis purposes.
- High-reliability Manufacturers
High-reliability manufacturers in the aerospace and military domain use curve tracing as part of the incoming receiving inspection chain as well as failure analysis.
Distributors who understand that providing their customers with screened devices improve their manufacturing yields and solidifies business relationships use curve tracers to screen their devices.
- Part Recovery Providers
There are many companies that legitimately recover high-value devices from otherwise failed PCB assemblies for reuse. These companies use curve tracing to find devices that were damaged by their recovery stresses.
- Law Enforcement
By law, selling counterfeit devices is illegal. To detect these devices, customs and FBI law enforcement officials use curve tracing to detect counterfeits and generate evidence to support their cases.
- Laboratory & Analysis Service Providers
Many companies who need to screen for counterfeits may not have the budget or resources to effectively test. So, contracts with independent labs are required to perform these tests.
RTI’s Curve Trace Test Methods for IC Counterfeit Detection
Unpowered curve tracing is the first line of defense. It’s also the simplest test method and the lowest cost hardware. It compares known good devices to all or a select few to screen out the worst of the bunch. Unpowered curve tracing can be done on a 2 bus MultiTrace.
Powered curve tracing increases test coverage and can discover degraded parts that otherwise look normal by way of unpowered curve tracing. Powered curve tracing requires a 4 or 6 bus MultiTrace configuration.
Supply Current Characterization
Supply current characterization has the broadest test coverage but has the simplest results. Use the powered curve trace method to get a broader view of the supply current range and which pins influence it the most. Powered curve tracing requires a 4 or 6 bus MultiTrace configuration
RTI’s Curve Trace Software for IC Counterfeit Detection
RTI includes a variety of features in the curve trace software for IC counterfeit detection. From Testing to Analysis to Final Documentation, RTI has all the bases covered for convenience, repeatability, and reproducibility.
Image Generation tools: Curve trace data is normally represented graphically. DataTrace has multiple file-formats it can save the results to, and multiple modes to generate these files. In addition to printing, DataTrace can create an image or thumbnail of each pin in the file and with many results overlaid.
Efficient Data Handling: Windows-based file systems allow you to store your results in folders the same way you handle your files on a Windows desktop. Curve trace files are compact and many can fit on a typical HDD.
Variable Sample Size: Whether you test a small sample from your lot or all of the parts, RTI’s software has features to help you collect and analyze a mountain of data and bring it down to manageable tasks.
Data Archiving: All data is digitally saved. Using devices from previous test lots to compare to new lots is a good way to evaluate the consistency of the product over multiple manufacturing or date code lots. The more parts you test, the more examples you will have available to use as known good devices.
DataTrace Pro offers several ways to evaluate your curve trace results and write reports when testing large lots or small sample sets.
The Standard Compare tool allows you to compare result files against your chosen known good device file in pairs. This method allows closer inspection and faster evaluation of results.
The Advanced Batch Compare tool is available only in the Full and Analytical Packages of DataTrace Pro. It allows one to compare large sets of results quickly and efficiently. Testing first then comparing later allows you to scan through any number of result files and compare it to a selected known good device file in one operation. This tool will generate a color-coded results grid elaborating failed pins which can be saved as a spreadsheet. Auxiliary bar charts allow you to quickly evaluate a larger set of results in one glance.
Advanced Test Sequencer
DataTrace’s Advanced Test Sequencer tool works with commands files so it is more flexible than the MTForms Test Sequencer. Save test sequences with fully custom file settings and configure for Auto Compare, AutoSave, and results logging. Results are continuously logged to a spreadsheet and log files while displayed on the operator panel for real-time evaluation of results.
With DataTrace’s Advanced Test Sequencer, parts can be tested by the thousands and reliably saved for review later or review the test log in real-time to find parts that may have failed for a retest and final determination. With the test sequencer, an operator needs only to load the parts and press a run test button.