Monthly Archives: February 2018

What makes a Soldering Iron?

Solder, usually an alloy of lead and tin, has a low melting temperature. Placed between two metallic objects and heated, solder melts and wets the two metallic surfaces. On cooling, solder forms a bond between the two objects. Originally, a heated iron piece brought the solder to its melting point, hence the name soldering iron. Later, people found copper to be a better replacement for iron piece.

People working with electronic components are the biggest users of the soldering iron today. To suit their needs, the soldering iron has had to undergo several improvements. The latest models can be those of the uncontrolled type or ones where the user can set the temperature of the tip.

The simplest form of uncontrolled soldering iron has an insulated hollow handle that has an electric cable passing through. One end of the cable terminates in a resistive heating coil wrapped around an iron rod, but insulated from it by a layer of mica. A metal tube attached to the handle and insulated from the heater protects the user from the heating coil. At the front of the iron rod, there is a special copper tip that heats up when electricity is allowed to flow through the heating coil. When the tip is sufficiently hot, it is able to melt a solder.

There are several disadvantages of the uncontrolled soldering iron. The continuous heating of the tip causes a layer of oxides to form on it, reducing its ability to melt solder, unless the oxide layer is frequently scraped off. Solder reacts with the impurities in the copper tip and causes pits to appear on its surface. This requires occasional filing to keep the tip free of pits. Some components are temperature sensitive and can be damaged because the soldering iron tip touching them while soldering is much hotter than they can withstand.

The above disadvantages led to the development of temperature-controlled soldering irons, where a temperature feedback from the tip controlled the power fed into the heater, enabling the tip to remain at a certain temperature. By controlling the amount of feedback, the user now had the ability to allow the tip to become cooler or heat up further.

The tip too underwent a lot of change. Rather than use a copper piece throughout, the tip was made with multiple layers of different metals, such as iron, aluminum, and hardened copper. A soldering station helped to house the control electronics to set and adjust the tip temperature, as well as to detect when the iron was actually resting between two bouts of active soldering so the control electronics could reduce the tip temperature at times of rest. As soon as the user picked up the soldering iron, the control electronics pumped in more power input to bring the tip temperature quickly up to the set point.

Earlier, the control electronics for the soldering iron was predominantly analog. The latest models feature a digital control. Analog control was simple where the user could turn a knob to set the temperature. However, the digital ones have more features. Apart from a digital display showing the tip temperature in either Centigrade or Fahrenheit that the user can select, the soldering stations usually have a few preset selections.

What is the Automatic Test Equipment PCB?

Targeted towards verification of the functionality of a specific semiconductor chip, all major test activities use an automatic test equipment printed circuit board (ATE PCB) or simply a test board. Testing semiconductor chips with advanced functionality is necessary for manufacturers to ensure their reliability and functionality to OEM customers, and establish they operate according to their specifications.

In simple terms, the ATE PCB serves as an interface between the specific semiconductor chip and a large test system. The design and assembly of ATE PCBs allows testing an array of a large variety of semiconductor chips that includes field-programmable arrays, system-on-a-chip, memory chips, microprocessors, micro-controllers, and many more. As semiconductor chips are complex, the design and assembly of one ATE PCB makes it capable of testing only one particular type of chip set at a time.

Chipmakers employ a group of experienced project and program managers, along with highly trained engineering personnel for designing and assembling ATE PCBs to achieve the unique chip-testing quality. For this, conventional PCB assembly knowledge and experience is not adequate, and requires enhanced assembly line technical expertise along with highly disciplined administration management. Any misstep towards a successful completion of an ATE PCB can result in considerable loss of time-to-market along with a huge monetary loss.

Compared to conventional commercial and industrial PCBs, ATE PCBs are considerably different, and chipmakers usually differentiate them in three main ways—their larger size, number of layers, and the extra processes necessary. ATE PCBs are highly reliable and extremely robust, and their fabricators take special care to free them of assembly process residues and debris.

As the ATE PCB is so different, it is also difficult to make. This requires program managers associated with ATE PCB projects to have knowledge beyond that required for conventional PCBs, including all the nuances associated with ATE PCBs. They need to understand unconventional illustrations and diagrams, as these are the hallmark of projects involving ATE PCBs.

At the same time, technical personnel associated with the assembly of an ATE PCB need high-level knowledge and skill-set. This includes relevant hardware, tester orientation and configuration, stiffeners, cables, and other paraphernalia related to the ATE PCB. Both the assembly engineers and program managers must thoroughly understand the electronic format input required for designing a custom ATE PCB.

Unlike the netlist format conventional PCBs use, the input for ATE PCBs is usually in the form of map drawings, bitmaps, and ball maps. That means assembly engineers and program managers must be fully capable of creating the appropriate netlist after translating the original data from these unconventional methodologies.

As the ATE PCBs are large, typically measuring 12 x 10 inches or 14 x 14 inches, the pick-and-place systems for assembling these PCBs are also unlike those for populating conventional PCBs. They are capable of handling and populating large footprint boards, such as 20 x 24 inches to 26 x 30 inches.

These pick-and-place machines are extremely precise and highly accurate. Some of the latest machines can easily populate a board with 32 thousand components per hour at 21-µm fine-pitch repeatability. Such advanced machines also have the capability of selective or spot soldering.

Raspberry Pi Control for Pool Temperature and Motor

Owners of swimming pools often have no idea of the temperature of the water in the pool relative to the surrounding air. They also are unable to control the pump schedules unless they put up a mains timer. However, using a single board computer such as the Raspberry Pi (RBPi) makes it easy to display the temperature on a webpage, while it switches the pump automatically on or off based on a preset schedule.

The pool monitoring system does not need a full version of the RBPi, as the RBPiZW, the Zero W version, will be adequate. For instance, the designer, Matt, designed the pool monitoring system for his summer escapes pool that holds 4100 liters of water. Matt designed the RBPiZW system to measure the water and air temperature and log the measurements to a cloud on the Internet. This allows the system to display temperatures on a web page he is able to access from a mobile phone, while allowing him to switch the pump on or off. The system can also place the pump on an automatic mode to follow a specific schedule.

Pool pumps are usually mains powered and contain a filter. Traditionally, users control this with a mains timer, but that precludes the possibility of switching it on when the solar panel supplies free power. For instance, the user may want to replenish the water at the end of the day after heavy use, and this is not possible without tinkering with the timer unit.

Matt housed his RBPiZW monitoring system in a weatherproof box. It offered room to include a 4-way extension block and has a 10 m mains cable running to it from the house. The box houses the RBPiZW and its 5 V power supply. The sensor wiring enters the box through rubberized slots.

According to Matt, the finished system comprises, apart from the pool and pump, a weather-proof box, a 10 m mains extension cable, an RBPiZW, a 5 V charger, a 4-GB micro SD card, two water-proof temperature sensors (DS18B20) each with 3 m cable, bias resistor for the temperature sensors, an Energenie Socket, and an Energenie Pi-mote as add-on.

The Energenie socket is a remote control socket. Additionally, when combined with the Pi-mote, it allows controlling the socket with Python scripts. Being easy to set up, this combination offered an easy hardware for controlling the pump. Matt had only to plug in the Pi-mote into the GPIO header of the RBPiZW.

The DS18B20 waterproof temperature sensors are single-wire interface and many of them can be connected to the GPIO pins. The waterproof sensors come with all cables attached. Although somewhat more expensive than the regular standard sensors, Matt only needed to solder the three wires from each sensor to the appropriate GPIP pins on the back of the Pi-mote to make them work.

Matt placed one of the sensors in a hedge near the pool for measuring the air temperature, while he dipped the other into the pool water to measure the temperature of the water. Each sensor has a 3 m cable length.

Advanced Control of 3D Printers through Voxel

The spectacularly astonishing new technology, additive manufacturing or 3-D printing, continues to grow thanks to reducing costs, new processors, and greater research. The price reduction comes mainly from an increase in the availability of and access to the technology to a broader audience. However, it has other things going for it too, such as increasing automation, expanding materials, improving software, and voxel control, all continuing to push the limits of additive manufacturing.

According to Rich Stump, principal and co-founder of FATHOM, manufacturers typically switched from 3-D printing to injection molding when they need to produce 300-400 parts at a time. However, newer 3-D printers such as the Continuous Build 3D Demonstrator takes that number up to around 1500-2000 parts. This allows customers to reap the benefits of time and cost with repeatable and constant 3-D printing. Not only does this reduce the complexity, but also offers advantages of the iterative design process. The latest 3-D printers are now posing a serious price challenge to injection molding, for bridge-to-production and low-volume runs.

However, 3-D printed metals often suffer from microscopic defects during production, as revealed by research that the Advanced Photon Source at the Argonne National Laboratory of the US Department of Energy has conducted. APS is the leading source of hard X-rays, necessary to image the process of additive manufacturing. Such research produces data for more accurate in-line inspections and helps drive the AM market towards improved reliability.

Apart from the importance of inspecting every centimeter of a printed part, fabricators are also interested in controlling the properties of those areas, and many companies are now working in this area. Just as a pixel relates to a photo, a voxel is a part of the three-dimensional object. Therefore, envision a three-dimensional object made of tiny cubes or voxels. Companies are now trying to control the properties of each voxel individually to allow changes in durometers, color, and other properties.

By controlling the property of individual voxels, fabricators are able to control properties of the metal such as conductivity and thermo-insulation. Introduction of thermo-conducting inks helps to create active sensors smart enough to have a 3-D printed active material within the part. For instance, it is even possible to create a battery within the 3-D printed structure.

Today, da Vinci Color and Mcor of XYZ Printing can print in color. Although Mcor has been in the market for long, they only build layers of paper following a lamination process. On the other hand, the da Vinci Color uses the extruded plastic process they call as the Fused Filament Fabrication (FFF) process. This is similar to amalgamating a 2-D color printer with a 3-D printer. The results are spectacular—the new da Vinci Color produces 10 million shades of colors and prints at speeds of 30-60 mm/sec.

Hewlett-Packard has a plan to exhibit further control on the voxel in the coming year. They intend to introduce full color to the 3-D printing scenario. Combining the color capability with a lower pricing is the strategy for Hewlett-Packard, according to Stephen Nigro, president of HP’s 3-D printing business partner.

Advanced PCB Technologies — High Density Interconnect

Engineers often face a peculiar dilemma. On one hand, they need to enhance the functionalities of electronic gadgets they design so that customers have more value for their money, while they are constrained to use a sleek form factor. Not only does this impose a tremendous challenge to cram many components within a highly restricted space, but the challenge extends to maintaining the quality and integrity of the design as well.

Designers meet the challenge in different ways. They use subminiature passive SMD components, often as small as 0402 (0.4×0.2 mm), special fine pitch ICs in packages such as CSP, TQFP, and BGA, and advanced printed circuit technologies that offer thin flexible, multilayer boards, especially the high density interconnect (HDI) types.

Designers use several advanced technologies in producing HDI boards. For instance, rather than using glass fibers for producing the base substrate, HDI boards use Polyimide and similar materials, as these are flexible, more durable, and can withstand very high temperatures without degenerating.

Designers use special plated through vias to interconnect different layers in a multilayer HDI board. Rather than drill holes in the PCB layers using metal drills, fabricators of HDI PCBs use lasers to drill extremely small microvia holes in the layer, which they later electroplate with copper. Since these microvias can be as small as 15-30 µm, they take up very little space on the PCB, leaving a large area for routing the traces.

Designers use traces with width as small as 20 µm to route the circuits on HDI PCBs. In combination with microvias, these thin traces allow them to achieve extremely high routing densities impossible to achieve on regular boards. This is especially helpful when designing with fine pitch ICs and high pin count BGA IC packages that have a pitch as small as 0.5 mm.

BGAs are surface mounting packages with solder ball arrays on their bottom surface. Large BGAs may have as many as 560 solder balls. With pitch size as small as 0.5 mm, it is nearly impossible for designers to run traces from each pad under the BGA. However, engineers have solved this problem in a rather unique way.

In regular PCB design, using vias within pads is taboo, as this causes dry solders. The plated through via wicks away molten solder, leaving very little solder between the pad and the IC pin. However, designers regularly use via-in-pads in HDI PCBs, as this allows them to save a lot of space that they can use for routing. Molten solder does not travel down the microvia in HDI PCBs, as fabricators fill them up and plate them over. This has another advantage, as filled vias become better conductors of heat.

Another trick a designer often uses for gaining higher routing density in HDI PCBs is placing different types of vias such as blind and buried types. Vias connecting inner layers in a multilayer PCB are buried vias, while those originating on one of the outermost layers and connecting to one of more inner layers are blind vias. Unlike a through via that passes straight through the board, designers can stagger blind and buried vias in different layers to achieve higher routing density.

How mSAP Enhances HDI PCB Capabilities

With 5G technology around the corner, we are looking at the emergence of 5G smartphones. While this requires new manufacturing technologies such as high-density interconnect Printed Circuit Boards (HDI PCB), smartphones need to be less expensive and produced at greater efficiencies.

Customers usually covet compact sleek devices. Therefore, manufacturers need to balance function and form so that their products stand out in a crowd in a competitive marketplace. The smartphone market can be a treacherous place with corporate fortunes rising and falling on the success and failures of specific generations of phones.

Smartphone designers tend to use every millimeter of space within the device enclosure to unlock significant value for the user. This is how they are able to fit in large and high-resolution displays, large batteries, and more sophisticated processors. This allows designers offer more functionality with an enhanced feature set, ultimately improving the overall user experience.

As most of the design of a smartphone is form-factor driven, PCBs in the form of high density interconnects are the major contributors. These HDI PCBs are specially designed circuits differing from conventional PCBs as they provide the designer with more functions per unit area. Their main advantage is finer copper traces, thinner and more flexible base material and laser drilled via holes. Although HDI PCBs have played a crucial role in creating miniature smartphones and other embedded subsystems, 5G technology demands are more severe.

The new generation smartphones compatible to 5G requires extremely complex RF front ends and antenna configurations involving multiple inputs and multiple outputs—generally known as massive-MIMO. This not only expands the footprint of the RF content within the phone, but also enhances the processing power necessary to control the staggering volume of 5G data. Simultaneously, all the extra features and functionality affects the battery capacity, and hence, the geometry of the phone. Conversely, if the phone geometry is not to increase drastically, the 5G smartphone will have much less space for the HDI PCB inside.

With the reduction in internal space for the PCB, and use of higher 5G frequencies, designers will need to exercise much stricter control on the impedance of traces. Unless they design with extreme precision, the thin traces in HDI PCBs can increase the risk of signal degradation resulting in lapses of data integrity.

PCB designers and fabricators are overcoming these challenges by following the mSAP process. Fabricators of IC substrates generally use this semi-additive process, and HDI PCB fabricators have adopted its modified version.

Typical line to space ratios on the HDI PCBs are 30:30, meaning designers plan for a spacing of 30 µm between adjacent traces of 30 µm width each. Demands of increasing density are forcing fabricators towards line-space ratios of 25:25 and even 20:20, with the help of mSAP. This enables makers of 5G smartphones and other demanding gadgets to achieve unprecedented densities while offering superior geometries with exacting impedance control for their high frequency operation.

Contrary to the subtractive processes used for normal PCB etching, mSAP does the reverse, essentially coating a thin copper trace onto the laminate and subsequently building up its thickness by electroplating over it.

What Are Thermoelectric Modules?

Discovery of the Peltier effect in 1834 led to the development of solid-state heat pumps, but the devices became commercially available only in the 1960s, when the combination of ceramic substrates with advanced semiconductor thermocouple materials made it possible. Solid-state heat pumps or thermoelectric modules utilize the Peltier effect to dissipate heat through a heat exchanger.

While operating, DC current flowing through the thermoelectric module creates heat transfer and a temperature differential across the ceramic surfaces. This causes one side of the thermoelectric module to be hot, while the other side grows cold. Although single-stage standard thermoelectric module can achieve temperature differentials up to 70°C, modern semiconductor materials can exceed this limitation.

Regular cooling technologies such as fans have moving parts that can wear out and need maintenance. However, thermoelectric modules, being solid-state with no moving parts, are highly reliable. While single thermoelectric modules can cool devices well below the ambient temperature, use of multistage thermoelectric modules in a vacuum environment can achieve colder temperatures, down to -100°C.

Simply reversing the polarity of the current flowing through a thermoelectric module can reverse its ability to heat and cool, as the reversal of current direction also changes the direction of heat transfer. This allows achievement of a very precise temperature control under steady state conditions—to the order of ±0.01°C. While heating, thermoelectric modules are much more efficient as compared to conventional resistance heaters, as they can generate heat from two sources—one, the input power supplied, and two, the additional heat generated by the heat pumping action.

A typical thermoelectric module physically measures 30X30X3.6 mm. However, they can have geometric footprints as small as 2X2 mm or as large as 62X62 mm, while being very lightweight. Therefore, thermoelectric modules are well suited for applications with space or weight constraints as compared to much larger cooling technologies offered by conventional compressor-based systems. Some applications also use thermoelectric modules as small power generating sources, converting waste heat into energy in remote locations.

Thermoelectric modules are well suited for applications where active cooling is required for reaching temperatures below ambient with cooling capacity requirements up to 600 W. Design engineers consider using thermoelectric modules when faced with system design criteria such as high reliability, precise temperature control, low weight, compact geometrical constraints, and other environmental requirements. Thermoelectric modules are in use in industries such as food and beverage, consumer, telecom, medical, photonics and many more.

Manufacturers offer several types of thermoelectric modules suitable for different applications. For instance, some have a wide breadth suitable for higher current and higher heat pumping applications and operating temperatures of 80°C. Other modules have several surface finish options such as pre-tinning or metallization to allow soldering the thermoelectric module to the mating conduction surfaces.

For achieving higher temperature differentials, designers stack thermoelectric modules one on top of another to create a multistage module. However, these multistage modules are suitable only for lower heat pumping applications.

Manufacturers design special modules that will work in both heating and cooling modes reversibly. Standard modules are not suitable here as they will be unable to withstand the thermal stresses these applications generate.

Selecting Universal Motor Controls

Inside the home, one will find a number of gadgets with the universal motor dominating. Mostly, these are used in high speed, low-cost motor applications, such as in power tools, vacuum cleaner, and countertop blenders. However, not all gadgets perform equally. For example, a bargain-basement blender may make a lot of noise when working. Others may be relatively quieter. While some products have a tendency to overheat, others run cool even if you load them over. Actually, the motor itself has little to do with the wide variation in performance. Mostly, the lifespan and performance of the universal motor depends on its drive circuitry.

If speed control is not necessary, gadgets have their universal motors simply connected to the AC mains or to the DC rail, as this is the most cost-effective method for driving the motor and letting it spin. However, the speed of the universal motor depends largely upon the voltage applied, and connecting it directly to the voltage source allows it to spin at its maximum speed at minimum load.

While connecting directly to the voltage source for maximum speed might suit power tools or a vacuum cleaner, other applications may require the speed of the shaft to vary. Designers accomplish these using subtractive measures, mostly by reducing the motor voltage. This helps to reduce the speed to a fraction of the maximum RPM.

One can power universal motors through either alternating voltage or direct voltage, with each approach having its own advantages and disadvantages. While DC control circuits tend to be more expensive than their AC counterparts are, the DC controls have the advantage of prolonging the motor life, and offer noticeably quieter operations, with improved efficiency.

Running a universal motor on alternating voltage and implementing a lowest-cost speed control entails feeding the motor varying amounts of the AC half-cycle. The cheapest open-loop method employs two semiconductor devices, a Triac triggered by a Diac, with a series RC network controlling the phase at which the Diac fires.

Closed-loop controls replace the Diac with a low-cost 8-bit micro-controller. Apart from offering improved control of the Triac, use of the micro-controller results in a closed-loop speed control, more sophisticated user interface, and a proprietary software-based design. By digitally monitoring the motor voltage and current under load, most applications are able to forego the use of a tachometer on the motor shaft for feedback.

Although the above makes for a very economical drive, the downside to using this approach results in a high current ripple, making the operation run fairly noisy. Dissipations in the Triac reduces the efficiency of the approach, with the thermal strain on the brushes ultimately reduces their life.

DC drives, on the other hand, take a different approach. Regulated DC power to the motor is pulse-width modulated, with the rate of rotation of the shaft being directly proportional to the duty cycle of the PWM waveform. When the energy supplied to the motor is low, it spins slower.

The DC drive has the advantage of higher efficiency, reduced noise, highly responsive speed regulation, prolonging the motor life. Overall, the application may use a smaller motor.

Interfacing the Tilt Hydrometer and Thermometer to the Raspberry Pi

Tilt is a wireless hydrometer and thermometer combination suitable for home brewers that allow instant readout of the specific gravity of your brew. You can see the specific gravity readings on your Apple iPhone, iPad, or Android smartphone. Furthermore, Tilt can talk to your single board computer, the Raspberry Pi (RBPi).

Tilt will talk to most devices sporting the Bluetooth 4.0+ interface. Once you have the data in your device, you can optionally save the data automatically into a cloud using Tilt’s free Google Sheets template. You can also save the data using other third party cloud platforms as well.

For helping home brewers make better beer, the Tilt hydrometer allows automatic checking of its specific gravity and temperature even while it is fermenting. Simply dip the Tilt hydrometer in the beer within your fermenter and leave it inside. Without having to open your fermenter again, you can receive the data on its present status, and this makes brewing simply more consistent and easy to track.

Tilt has a powerful transmitter, allowing it to send data wirelessly even through large thick-walled fermenter. Therefore, you get a better range and reception. With its sensitive sensors such as the improved temperature sensor and accelerometer, you get precise readings. Power consumption is low, which means Tilt does not consume much battery power while operating.

Operating the Tilt could not be simpler, as each unit comes calibrated and a pre-installed battery, ready to go—you only need to download the free app. Now sanitize your Tilt and drop it in your fermenter. You will automatically receive data on your device.

If you have different batches of fermenting beer, use multiple Tilt Hydrometers. You can differentiate those using separate colors for each batch. The app does not read multiple hydrometers of the same color. The Tilt has a range of 0.990 to 1.120, and gives an accuracy of ±0.002. The thermometer has an accuracy of ±0.5°C (±1°F).

If you have an RBPi with a Wi-Fi dongle and Bluetooth 4.0+ or BLE, you can use the Tilt Pi to log your Tilt readings. Tilt Pi is an SD card image, which you can download from the Tilt webpage and use to boot up your RBPi3 or RBPiZW. After downloading the image, simply write it to an 8GB or higher SD card.

On the SD card, Tilt has included a SETUP.html file that helps with the Wi-Fi and cloud logging setup. This file guides you in creating the configuration files that allow connecting to your local Wi-Fi network. You will also receive an email giving a link to your cloud data log. Another link will also point to your Tilt Pi dashboard, from where you can change settings, calibration, and view the data on your local network.

The Tilt Hydrometer does not include the RBPi, so you will have to buy one. The built-in Bluetooth and Wi-Fi wireless technology included in the Tilt Hydrometer offers reliable cloud and local data logging. The setup is streamlined, so as soon as the RBPi boots up with the Tilt Pi SD card, the system begins logging data.

How Are Industrial Lasers Cooled?

There are several varieties of industrial lasers. Some lasers, such as fiber lasers, have specific arrangements that enable spreading the heat they generate over a larger surface area. This arrangement gives fiber lasers better cooling characteristics over other media. Other lasers need extra cooling arrangements to remove the heat they generate. For example, ion lasers generate extreme heat when active and need elaborate cooling methods. Other lasers, emitting energy in the microwave and far-infrared region of the spectrum such as carbon dioxide lasers are immensely powerful, and cut hard material such as steel. The laser essentially melts through the material it focuses on. The problem is these industrial lasers have a limited surface area from where to exchange heat.

Although people traditionally use thermoelectric modules as heat exchangers, their efficiency has always limited their application. Now, thermoelectric modules are available which exhibit high heat flux density and are able to achieve higher heat pumping capacity compared to standard thermoelectric modules.

For instance, the UltraTEC series of thermoelectric modules from Laird has heat-pumping capacity of up to 340 Watts, which is fully adequate to cool applications such as industrial lasers that offer only a limited surface for heat exchange.

Industrial laser applications are numerous, including drilling, additive manufacturing, micro machining, welding, and cutting. Irrespective of the application, industrial lasers generate tremendous amounts of heat, which needs to be quickly and effectively removed to allow the laser to perform long-term and properly. Cooling lasers efficiently has always been a significant challenge for the industry.

Typical methods of cooling include transferring the excess heat by conduction or convection. Air may be used to remove the heat directly, or the heat could be transferred to a coolant, usually circulating water. The water carrying the heat is then circulated through a chiller or any heat transfer system. However, these arrangements depend on the system size and configuration, and can be expensive, complex, and noisy.

The UltraTEC series of thermoelectric modules offers excellent heat pump density, and allows precise temperature control. In fact, under steady state conditions, temperatures can remain within ±0.01°C. As these thermoelectric modules offer solid-state operation, these cooling solutions do not produce noise or vibrations. Moreover, they are available in multiple configurations, making them simple to implement.

Any laser system needs to be accurate and repeatable. Stability of the laser system is highly dependent on balanced, controlled cooling. The advantage of using UltraTEC thermoelectric modules for cooling is they can deliver highly reliable cooling solutions under conditions where the laser is in continuous use and even when cycling at high powers.

Laird assembles UltraTEC thermoelectric modules from Bismuth Telluride semiconductor materials. They use aluminum oxide ceramics, which are thermally conductive. This makes the UltraTEC thermoelectric modules capable of carrying high currents that are necessary for large heat-pumping applications. For instance, with Qmax rating of 340.6 W at 25°C, these thermoelectric modules can operate continuously up to 80°. This adequately ensures that the laser system will never overheat when being cooled by the high heat pump density UltraTEC series of thermoelectric modules. These modules are RoHS compliant and DC operated.