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How Counterfeit Electronic Parts and Components Affect Businesses

Although counterfeiting has been an age-old industry, it is only recently that the impact of counterfeit electronic parts and components has come to be highlighted. The public is slowly gaining the awareness of the implications and risks such counterfeited electronics bring to trusting users.

It is difficult for manufacturers to trace the origin of the counterfeited parts compared to the traceability present for the authentic components. It is possible these are older, but legitimate versions of the part, and someone has reprocessed them. On the other hand, these are legitimate fakes, which someone is trying to pass off as real. In both cases, their quality is highly suspect. Receiving counterfeit electronic parts or components in your business can result in mechanical and electrical defects, leading to financial risks and finally to loss of reputation and goodwill.

Mechanical Failures

Scrupulous elements recover a huge number of electronic components and parts from e-waste and reprocess them to sell as new. However, the stress of reprocessing these parts, especially integrated circuits, makes them susceptible to damage. As reprocessing elements do not usually follow proper manufacturing processes, they compromise the integrity of the components, and they occasionally fail to meet the stringent environmental requirements in the field.

Electrical Failures

While reprocessing, usually there is little or no effort to protect the component from ESD damage. Although the counterfeit component may be functioning in the circuit, it is difficult to predict when they will fail. The typical design of genuine electronic components allows them to function for a certain amount of time under specified conditions of use. Reprocessed parts generally fail as their useful life has been exceeded or they have endured dubious production controls and improper processing before they were resold as new.

Financial Risks

Counterfeit electronic components malfunctioning in the product or failing within the warranty period may lead to huge financial ramifications for the business. The financial risks may not be restricted only to simple replacements of the product, but may involve insurance compensations in case human lives are endangered, as could happen in premature failure of sensitive medical devices. The short-term savings from using counterfeit components may not be worth it, considering the financial backlash may turn out to be too huge for the business to handle.

Loss of Reputation and Goodwill

It takes a lot of effort to build up credibility, reputation, and goodwill in business, and these are essential for sustenance and growth of the business. However, the above can only happen provided the customers perceive the products to be of the quality and reliability the business claims they are. Counterfeit electronic components and parts leading to mechanical or electrical malfunctions and failures can easily undermine customer confidence in the business, leading not only to financial loss and legal hurdles, but also to loss of reputation and goodwill.


For safeguarding the business, its customers, its reputation, and goodwill, it is necessary for a business to take proper steps to prevent any incoming counterfeit parts and components.

Different Types of Feedback Encoders

All closed loop systems use feedback to control speed and or position. This plays an important role in keeping equipment operating accurately and smoothly. When using feedback for the best benefits in an application, it is important to understand how feedback works, because a variety of devices as well as models is available for the purpose. The most popular among them are tachometers, Hall sensors, encoders and resolvers.

Tachometers are rotating electromagnetic devices. Typically, these are connected to the shaft of a motor, rotating when the shaft rotates and generating a voltage as a signal. The faster a tachometer shaft rotates, the larger is the magnitude of the voltage output. Therefore, the output signal is directly proportional to the speed of the motor shaft. The polarity of the output voltage indicates the direction of rotation, clockwise or counter clockwise.

Usually, analog or DC tachometers provide direction and speed information. When fed to a meter, this information can be used in servo control for stabilization. DC tachometers are the simplest of feedback encoders.

Hall Sensors
Hall sensors are solid-state electronic devices and they can sense or detect magnetic fields. The output of the sensor changes or flips whenever a magnet comes close to a Hall sensor. Therefore, a Hall sensor provides a digital output as either a high or a low voltage.

Hall sensors are used for brushless motor applications, providing information about rotor position. This works as an electronic commutation, with the controller using the information to turn on or off specific power devices applying power to the stator windings.

Encoders are simple mechanical-to-electrical conversion devices and turn mechanical rotary motion into velocity or position information for systems controlling motion. Encoders can be rotary, digital, optical or incremental types.

In its most basic form, and encoder consists of a light source, a mask, a coded disk and a photo sensor along with related electronics. After passing through the mask and the coded disk, light from the source is detected by the sensor. As the encoder shaft rotates, light is alternately passed through or blocked, making an alternating light and dark pattern.

The associated electronics converts this into an electrical signal representing high or low corresponding to light passing through or being blocked. The resolution desired for the application governs the number of lines etched on the coded disk. By counting the number of pulses, the position of the shaft relative to its starting position is known.

There are two types of encoders, classified as incremental and absolute. Absolute encoders generate a specific address for each shaft position throughout the 360-degree rotation of the shaft.

What are Leadless Packages?

Electronic components, especially semiconductors have undergone a dramatic transformation over the past few decades. Starting from the through-hole packages, semiconductors evolved into the surface mount packaging, which is the default today. With the increase in packaging density, surface mount packaging is now limited to passive components mostly, while semiconductors are moving towards current technologies involving leadless packaging.

Modern technologies involve leadless packaging such as dual/quad flats with no leads (DFN/QFN), Ball Grid Arrays or BGAs and Chip Scale Packaging or CSP. Such innovative technologies are allowing the semiconductor industry to exploit the successive IC processing shrink and achieve product performances, which were thought impossible earlier

For example, consider a simple three-pin discrete device such as a MOSFET, typically used as a switching device that can conduct currents ranging from 0.1A to more than 100A at voltages surpassing 1000V. Applications as diverse as motor controls to battery management use MOSFETs.

Leadless packaging makes discrete devices more attractive because of the assembly efficiencies involved that makes them friendlier to the environment. Although several leadless solutions are possible for packaging MOSFETs – BGAs, CSPs and DFN/QFN – the governing factor here is mainly the market price pressure. Substrate costs may be expensive, making package material sets undesirable for BGA packaging. Moreover, capital expenditure required to changeover to full production with new packaging types such as BGAs and CSPs may increase the per-unit cost.

Consequently, BGA and CSP packaging is limited to discrete semiconductor applications where the average selling price is of a secondary consideration over more important parameters such as performance. At present, the traditional surface mount packages are being replaced by the more cost-effective alternatives leadless package solutions such as the DFN and QFN.

The manufacturing steps for a typical DFN package consists of six key processes. A silicon die is attached to a copper alloy or similar leadframe using a highly conductive epoxy resin. The package pads are then attached to the silicon die using wirebonds of aluminum or gold. The silicon and leadframe package is then hermetically sealed with a mold of a halogen-free compound. Sawing the molded lead frame yields the finished package product.

Leadless packages offer several advantages. They utilize the available board-space more efficiently, while improving the thermal performance of the device. For example, the SOT23 package, being one of the most widely used packages of the semiconductor industry, has a silicon-to-footprint ratio of 23%, while it occupies 8mm2 space on the printed circuit board. Comparatively, The DFN2020 package has a silicon-to-footprint ratio of 42%, which is nearly double that of the SOT23, while it occupies only 4mm2 space on the PCB. This leads to huge cost benefits to the manufacturing industry, while simultaneously increasing the electrical performance of the application.

The DFN package has a highly conductive copper alloy pad for the die, which is exposed to the outside of the package to be soldered. This larger area of contact between the DFN package and the printed circuit board results in a very low thermal impedance between the junction and the leads. This ensures not only a reliable contact, but also a higher thermal efficiency as compared to typical surface mount packages.

How does temperature affect component life?

Change in temperature affects the speed, power and reliability of electronic components and systems. Variation of temperature affects the speed performance, because material characteristics depend on temperature. These dependencies may be normal or reversed based on the type of the semiconductor material. Additionally, these dependencies change with technology scaling, and manufacturers counteract by introducing new processing materials, using metal gates and high-K dielectrics.

For example, temperature influences various performance functions in a MOSFET. These include the carrier density, energy band gap, carrier diffusion, mobility, current density, velocity saturation, leakage current, threshold voltage, electro-migration and interconnect resistance.

Temperature dependence of carrier density for a doped material occurs in three distinct regions. The material has just enough latent energy in the ionization region to push a few of the dopant carriers into the conduction band. When the material is in the extrinsic region, which is the desired region of operation, the carrier concentration remains flat over a wide range of temperatures.

This region has all the dopant carriers energized into the conduction band, and there is minimum generation of additional thermal carriers. However, as the temperature increases, the extrinsic region converts into the intrinsic region, with the number of thermally generated carriers exceeding the number of donor carriers. Typically, the intrinsic carrier concentration in a material is generally much smaller than the concentration of dopant carriers at room temperatures. However, intrinsic carrier concentration is highly temperature dependent and once the number of thermally generated carriers exceeds the number of dopant-generated carriers, the potential for thermal variation problems increases substantially.

At low temperatures, lattice vibrations in the material are small and electrons move more slowly. Thus, ion impurity forces dominate the limit to mobility. As temperature decreases, it takes less time for an electron to pass an impurity ion, which means the mobility decreases. The reverse is true when temperature rises; the carrier’s thermal velocity increases, consequently decreasing the impact of interface charges.

With an increase in temperature, the kinetic energy of particles within the material also increases, effectively increasing the diffusion component of the total current. Two parameters, mobility and carrier density affect the total current through the material. While the carrier density remains nearly fixed with temperature over the extrinsic range or the intended range of operation, the mobility term or the drift component of the total current actually decreases with an increase in temperature.

Since the temperature dependencies of diffusion and drift currents are of opposing nature, the net current change depends on the applied electric field and affects the threshold voltage and leakage current of the MOSFET. Manufacturers typically design the MOSFET such that its threshold voltage decreases linearly with increasing temperature. However, the leakage current doubles for every 10°C rise on temperature.

The resulting change in device current based on temperature can have devastating effects leading to timing failures, systems exceeding power or energy budgets and errors in communication between cores. This is more commonly known as reverse temperature dependence, which is the increase of electrical conduction with increase in temperature, first discovered by C. Park of Motorola, in 1995.

Special heat sinks for heavily populated boards

Designers have to manage airflow carefully when solving the task of cooling heavily populated PCBs or Printed Circuit Boards. For effective cooling, the movement of airflow along the board is important. Two factors play a crucial role when selecting and qualifying heat sinks for dense PCB applications. The first factor is thermal resistance and the other pressure drop.

Thermal resistance is the increase in temperature in degrees Celsius for every watt and it measures how effectively the heat sink transfers heat from the heat-generating device to the ambient environment. A better heat sink has a lower thermal resistance. In other words, a better heat sink offers lower resistance to heat flow, such that it can cool hotter objects faster. Another way to say the same thing is heat sinks with lower thermal resistance cool hot devices before they reach their maximum allowed temperature. For any heat sink, its thermal resistance value depends on the airflow over the heat sink. Faster airflow results in lowering the thermal resistance values.

Pressure drop, the other factor, is the resistance the air faces while moving through the fins of the heat sink. This is the difference in the airflow speed as it enters the array of fins of the heat sink to the airflow speed of the air as it exits the array. If the pressure drop is more, it means the heat sink is taking up more air for its own heat removal, leaving less air for the other devices on the board. Therefore, with heavily populated boards, designers must balance the low-pressure drop and the low thermal resistance for a heat sink. This requires a good understanding of the relationship among pressure drop, airflow, heat sink fin-density and heat sink performance.

The performance of a heat sink is highly dependent on the speed of the air stream approaching the heat sink. Air, being a bad conductor of heat, tends to move slowly while circulating on the surface of the heat sink. A faster air stream pushes the hot air away from the heat sink and lets in cooler air, resulting in better heat removal. For heat sinks that have many fins, air remains trapped within the fins because the low speed of the incoming air does not move the hot air away from the fins. Therefore, to enable a densely populated heat sink perform efficiently, forced air cooling is necessary; this improves thermal resistance more than 100 times in certain heat sinks, compared to natural convection cooling – that is, cooling without airflow.

When the board contains only one heat sink, the selection is simple as the thermal resistance of the heat sink is the predominant factor. For multiple heat sinks on a board, the allocation of available airflow along the board takes predominance. All heat sinks on a densely populated board, apart from affecting the device that each resides on, also affects the neighboring devices. Therefore, for proper selection of a heat sink depends on both its thermal resistance and its pressure drop.

How did the diode get it’s name?

Although most diodes are made of silicon nowadays, it was not always so. Initially, there were two types – thermionic or vacuum tube and solid state or semiconductor. Both the types were developed simultaneously, but separately, in the early 1900s. Early semiconductor diodes were not as capable as their vacuum tube counterparts, which were extensively used as radio receiver detectors. Various types of these thermionic valves were in use and had different functionalities such as double-diode triodes, amplifiers, vacuum tube rectifiers and gas-filled rectifiers.

The diode gets its name from the two electrodes it has. Both the thermionic as well as the semiconductor type possess the peculiar asymmetric property of conductance, whereby a diode offers low resistance to flow of current in one direction and high resistance in the other. Similar to its vacuum counterpart, several types of semiconductor diodes exist.

The first semiconductor diode was the cat’s whisker type, made of mineral crystals such as galena and developed around 1906. However, these were not very stable and did not find much use at the time. Different materials such as selenium and germanium are also used for making these devices.

In 1873, Frederick Guthrie discovered that current flow was possible only in one direction and that was the basic principle of the thermionic diodes. Guthrie found that it was possible to discharge a positively charged electroscope when a grounded piece of white-hot metal was brought close to it. This did not happen if the electroscope was negatively charged. This gave him proof that current can flow only in one direction.

Although Thomas Edison rediscovered the same principle in 1880 and took out a patent for his discovery, it did not find much use until 20 years later. In 1900s, John Ambrose Fleming used the Edison effect to make and patent the first thermionic diode, also called the Fleming valve. He used the device as a precision radio detector.

To put it simply, a diode functions as a one-way valve. It allows electricity to flow in one direction while blocking all current flow in the reverse direction. The semiconductor diode has an anode (A, p-type or positive) and a cathode (K, n-type or negative). Since the cathode is more negatively charged compared to the anode, electric current will not flow if the cathode and anode are charged to the same or very similar voltage.

This property of the diode allowing current to flow in only one direction is utilized during rectification, when alternating current is changed to direct current. Such rectifier diodes are mostly used in low current power supplies. For turning a circuit on or off, you need a switching diode. If you are working with high-frequency signals, band-switching diodes are useful. Where a constant voltage is necessary, there are zener diodes.

Diodes are also used for various purposes such as the production of different types of analog signals, microwave frequencies and even light of various colors. When current passes through Light Emitting Diodes or LEDs, it emits light of a specific wavelength. Such diodes are used for displays, room lighting and for decoration.

Learn about metal film resistors

Resistors are a common passive item in any electronic assembly. They are used for restricting the amount of current flowing in a circuit; acting much as a valve does in a water pipeline. The most commonly in use are carbon, thick metal and thin metal film resistors. The film forms the resistive material of the resistor.

The axial resistor is usually a cylindrical conductive film on a non-conductive ceramic carrier. Two leads projecting from both ends of the resistance help in connecting the item electrically within a circuit. Although the appearance of a metal film resistor is very similar to that of a carbon film resistor, the former has much better properties of stability, accuracy and reliability.

A cylindrical ceramic core of high purity forms the base of a metal film resistor. Manufacturers mostly use a method known as sputtered vacuum deposition to deposit a thin metal layer on this ceramic base. This combination is then kept at a low temperature for a long period, which results in very good accuracy for the resistor. Mostly, the resistance material used is nickel chromium (NiCr), however, for special applications, other alloys such as tin and antimony, tantalum nitride with platinum and gold are used as well.

The thickness of the metal film strongly governs the stability of the resistance. Typically, a metal thickness of 50-250nm is a good compromise between better stability and lower resistance value. For connecting to the circuit, two end caps with connecting leads are pressed on to the two ends of the resistor body.

To obtain the desired resistance a laser beam cuts a spiral slot in the thin metal layer. This is a more modern method as compared with grinding techniques and sandblasting used earlier for trimming the resistance value. Once the final value of the resistance is achieved, several layers of paint are placed on the resistor body, with each layer being baked individually.

Apart from providing a high dielectric strength, the coating protects against ingress of moisture and mechanical stresses. Color code bands on the body mark the resistor value along with the tolerance band. Metal film resistors are available with standard tolerances of 2, 1, 0.5. 0.25 and 0.1%, with the TCR or temperature coefficient of resistance lying between 50 and 100 ppm/K.

Metal film resistors demonstrate good properties for TCR, stability and tolerance. Because these resistors have a low voltage coefficient, they feature high linearity and low noise properties. Therefore, if any of your circuits need low noise, tight tolerance and low temperature coefficient properties, be sure to use metal film resistors. For example, active filters and bridge circuits use metal film resistors.

Metal film resistors show good reliability when operated from 80 percent down to 20 percent of their specified power rating. Although reliability generally increases if the resistor is derated 50 percent, going below 20 percent of the power rating at elevated humidity conditions usually diminishes reliability. Moreover, metal film resistors are more easily damaged by power overloads and voltage surges, as compared to carbon composition or wire-wound resistors.

Magneto resistive random access technology (MRAM) for better memory storage

Technologists researching at the laboratories of the National University of Singapore in the department of Electrical and Computer Engineering have developed a new technology that will help in enhancing storing information in electronic systems in a better and more durable manner. Called Magneto Resistive Random Access Technology, this innovative method increases the storage space considerably and ensures that all fresh data will remain intact, even when there is a power failure. The team of researchers, led by Dr. Yang Hyunsoo, has filed for a provisional patent in the USA. They claim that the development will bring about a structure that will be of use to MRAM chips of the next generation.

This innovative method of storing information has a very wide field of application. All devices in the field of electronics such as Personal computers, laptops, mobile phones and all mobile devices will benefit from this unique technology. Data storage is required in various fields of activity such as in transportation, avionics, military, robotics, industrial motor controls, management of energy and power. Another major user is electronic equipment for health care.

According to Dr. Yang, the new technology will increase storage space, and enhance the memory. According to him, computers, laptops, etc., do not need booting up and there is no necessity for using the “Save” key regularly. Fresh data is not deleted even when there is a stoppage of power, unlike the current DRAMs in use. What is of greater significance is the memory will last for a minimum of 20 years and maybe for an even longer period. Compare this to the present method of storing information, which gives the user only about a year of stored data. One of the best uses is in the case of mobile phones. According to Dr. Yang, “we usually need to charge them daily. Using our new technology we may need to charge them on a weekly basis.” This will be a substantial cost-saver.

MRAM, the new technology, enables data to be retrieved even if the equipment concerned is not powered up. Additionally, MRAM consumes low power and has high bit density. The new technology is expected to bring about a sea of changes in computer architecture. Manufacturers will find it easier to use MRAM as flash memory can be dispensed with. That will also help in bringing down the cost substantially. The success of MRAM has induced major semiconductor manufacturers like Intel, IBM, Samsung and Toshiba to conduct further research.

Currently, MRAM uses technology based on current induced magnetization in a horizontal plane. It requires ultra-thin ferromagnetic structures, less than 1 nanometer, which are difficult to manufacture, has low reliability and the retention period is less than a year. The NUS team collaborating with Saudi Arabia’s King Abdullah University of Science and Technology has developed a multi-layer magnetic structure of 20-nanometer thickness. It effectively provides a film structure that helps in the storage of information and data for at least 20 years. The team is looking for collaboration with the industry.

What Is An Electronic Load And Where Do You Use It?

Power supply manufacturers need to test their products dynamically. Instead of using fixed-resistor banks of different sizes, electronic loads allow them to simulate easily and quickly various power states. Using an electronic load, large ranges of power sources such as converters, inverters, UPSs and electromechanical sources such as batteries and fuel cells may be tested. For varying loads, electronic loads are easier to use and provide a much higher throughput compared to fixed-resistors.

For example, a handheld device may have to be tested for sleep, power conservation and full power modes. These are easier to test using a single electronic load, but may require several combinations of fixed-resistors. Additionally, an electronic load may be programmed to represent closely a real environment for a power source. This may take the form of modulation to improve the performance of power supplies by providing a faster transient response as compared to a standard power supply.

An electronic load usually consists of a bank of power transistors, power MOSFETs or IGBTs mounted on a suitably sized heat sink, and cooled with fans. An electronic circuit governs the amount of current that the power devices can draw from the power supply on test. To protect the power devices from damage, electronic loads usually have a pre-settable power limit. The manufacturer usually provides a power curve for the safe operation of an electronic load. The user must be aware of the simultaneous maximum voltage and current that can be applied to the electronic load to ensure the electronic load is not overpowered.

It is important to select a suitable electronic load for the testing. For example, a power supply rated for 12V and 30A, may never be operated at 12V and 30A continuously. While testing, the operator may run it at 12V and 5A and then at 3V and 30A. That means an electronic load of 90-100W is sufficient to test the supply.

To improve the performance of a power supply, an electronic load may be used as a high-speed current modulator. In such cases, only a fraction of the power rating of the power supply is required. When the current is modulated to the highest level, the voltage across the load is likely to be very low. As the current is modulated off, the voltage rises to its maximum. Usually, if the modulation of the current is from zero to some maximum, the load power required is one-quarter of the operating voltage times the current rating with some margin added.

Electronic loads are very useful for dynamically testing power sources. In this form of testing, the current is quickly pulsed between two states, simulating a possible sleep mode and a full power mode of a device. This pulsing can be as fast as 20,000 times a second.

Another requirement that electronic loads are adept at is low voltage testing. Although most electronic loads will refuse to operate when the applied voltage is below 1V, there are some models, which perform comfortably down to 0.6V. This is a very useful feature when testing fuel cells where the operation at low voltages is crucial.

Home Protection with Raspberry Pi

Planning to go on a vacation, but afraid of who will look after your home for you? Worry not, for the mighty Raspberry Pi (RBPi) is here. Not only will RBPi look after your entire house, it will send you an email of what is happening in your home and let you see it on your mobile or on a PC. How cool is that?

Most alarm systems incorporate three primary sensors. The first is a temperature sensor to detect the rise in temperature in case of a fire. The second is an intrusion detection sensor to detect if an intruder has gained access to the insides of the house and third is a motion detection sensor. Apart from these primary sensors, you may add smoke detectors and cameras according to your necessity.

The software consists mainly of a database to store all the events with a time stamp, a dashboard to display the status of the sensors, configure them and to program the alarm system. The Raspberry Pi also acts as a web-server to send email alerts and to display the dashboard on a remote computer or Smartphone.

Depending on the size of the home, its vulnerability and the number of sensors being used, you could divide the area into a number of zones. This makes it easier to arm the sensors belonging to a specific zone. For example, a door and few windows of your home may be facing a busy street during the day and you may decide not to arm the sensors in this zone in the daytime. As night falls, the street gets deserted and you may want the sensors in that zone to be armed for the night.

Dividing the home into zones also has the advantage of knowing in which area or areas the alarm has been triggered. The camera for that zone can then be switched on to assess the situation visually.

Since RBPi runs on Linux, and Linux multitasks very well, the software runs in the background. The software is programmed to wake up RBPi about once every minute and check in on each of the armed sensors in all the zones. If there is no activity, it simply updates the logs for the database and the dashboard and goes back to sleep.

If a sensor trips, or generates an activity, Raspberry Pi records it in its logs, and sends you an email with the details. The dashboard then indicates the alarm condition in the zone where the alarm originated. You have a choice of turning off the alarm after checking it out.

You can login to the server from a remote PC using a username and a password. The web-browser will display the dashboard and a green button lets you know that the RBPi is running your home alarm software and is transmitting the information from the sensors. If the alarm system goes down for some reason, or there is a problem with the connectivity between the Raspberry Pi and your computer, this green button will turn red within a minute. You can now proceed to test, arm or disarm the sensors in each zone. For details of software and setup, refer here.