“VCC has a massive inventory of products on hand, this is reassuring when our customers have short lead times and buy on demand”. I just can’t wait for my current supplier anymore. I found information about VCC Optoelectronics on the web and contacted their Sales Team right away. VCC recommended and had stock on a part that was slightly better than the parts we previously looked at for less money. Within days, we received the VAOL-10GSBY4 (10MM, single color Blue LED) samples VCC recommended which outperformed the current one in brightness “ Said Joel.

VCC is has a team of professionals that are dedicated to service and have the knowledge to quickly assist our customers in finding better, more efficient and complete solutions. Our large variety of LED’s with many different lighting, power and mounting capabilities will provide the options and available inventory you have been looking to find from your LED supplier. Contact VCC today with your project requirements and let us help find a solution for your project needs.

For more information on Bazzaz performance products please visit www.bazzazperformance.com.

As the LED heat escalates, several key characteristics may become apparent, which demonstrate the importance of LED thermal management. The forward voltage will begin to decrease. The decreasing voltage can impose an increased load on related LED driver components causing their temperature to increase as well.

In resistor driven circuits, the forward current will increase. As the LED lights temperature continues to rise, the optical wavelength can shift. The increasing wavelength can cause orange LED lights to appear red or even white LED lights to appear bluish. This color shift typically intensifies with the AlInGaP technologies (red, orange, amber, and yellow). In addition, a thermally stressed LED lights will loose efficiency and light output will diminish. If the LED thermal management continues to race out of control, the LED junction may break down causing a state of complete thermal failure.

Thermal failure is the total loss of electronic function due to melting, partial vaporization of the component, thermal fracture of a support or separation between the leads. Thermal issues can also result in joint stresses and hot spots on your board.

Thermal management techniques must focus on effectively dissipating heat generated by high-power designs, providing high thermal conductivity, and on maintaining low coefficients of thermal expansion (CTE), while managing CTE mismatches between LED’s, components, their interconnects and the PCB.

Manufacturers of LED’s and IC components use a variety of packaging chips and often times the components may have a lower CTE than the standard PCB. This results in a thermal mismatch between the device and the PCB. The environment in which your PCB is to be operating can affect performance as well. For every 20°C rise in component temperature, the failure rate doubles.

All VCC proprietary products use UL rated (94-V0) material to protect against melting on the board during the reflow and/or wave soldering processes eliminating some of these concerns for the engineer.

While LED chipmakers are doing their part to improve thermal management for their devices, the design engineer must take heat dissipation into consideration as well, from using applicable board materials (like the UL rated (94-V0)) to paying special attention to mounting holes.  The use standoffs and different connection techniques will be integral in obtaining proper airflow to assist heat dissipation. Check out our selection here.

New patents are being issued as the industry continues to develop a variety of new LED thermal management materials and techniques. There are several prominent developments that are in the tool kit of seasoned PCB designers and engineers.

There are proven techniques such as copper thieving, increasing trace thickness, and using the mounting holes to dissipate heat.  Newer techniques and developments include using thermal modeling software, new heat sink material, high conductivity carbon composite board layers, special casing materials, and edge plating. Below I’d like to cover the latest developments in the area of heat sinks, which have historically served as the workhorse for thermal management in PCB design.

Heat Sink Developments

Heat sinks help keep LED components at temperatures below their specified maximum operating temperature. There are many different designs and various ways of optimizing heat sinks.

Over time, the technology has progressed with the use of new materials like carbon fiber and boron nitride. These materials are implemented into multi-layer PCBs to efficiently move heat from one fiber ply to the next. Due to their high cost, however, these materials will likely find limited use in future PCB fabrication and may not replace aluminum heat sinks in many LED applications.

Fin-based aluminum or copper heat sinks retain greater acceptance in many LED applications due to their low cost and ideal thermal dissipation characteristics. Aluminum has a highly acceptable thermal conductivity, while copper is about twice as high. Aluminum heat sinks are inexpensive; copper ones cost more and weigh more. Consequently, aluminum is chosen for most cost-effective applications, and copper is used in selected ones where performance reigns over cost.

Finally, while most heat sinks are finned to provide a simple way of increasing surface area for heat radiation and conduction. Newly developed special aluminum fin material is reported to be 15 percent more conductive than fin material used in previous heat sinks.  These current developments are sure to become as essential as the heat sink device itself.

Regardless of the particular application, Engineers are in agreement regarding several ways in which LED devices provide advantages over other backlighting options such as CRT and fluorescent bulbs. The benefits of LED usage in backlight applications include:

• Improved Reliability – As they are solid-state devices, LEDs have a longer lifespan typically lasting over 100,000 hours. A benefit of solid state devices, LEDs will perform consistently from installation to end of life cycle as opposed to florescent options which continuously lose up to 50% of their light output over their life cycle.
• Lower Power Consumption – LED backlights have lower power consumption than traditional backlighting sources. Manufacturers quote a 60% reduction in power consumption for LED backlighting compared to conventional mercury-arc lamps.
• Blur Reduction and Brightness – LCD displays have a motion blur effect primarily because an LCD pixel remains lit, unlike the CRT phosphor screens which are strobed for a very short time. To resolve this issue, one of the latest improvements being employed by large manufacturers is to use LED for the backlighting. They then employ a new scanning technology that strobes the horizontal rows of LEDs from top to bottom. This approach is also superior in reducing computer generated motion blur produced by video games.
• Blacker blacks – The improved dynamic contrast ratio achieved through use of LEDs for backlighting creates improved contrasts, stronger blacks and whites as well as a greater range of color levels in between. This is accomplished by utilizing multiple LEDs to vary the backlighting across the LCD screen based on the image displayed.
• Wider Color Array – LED’s cover a broader range of red and greens well over the NTSC standards. This results in a more extensive range of colors allowing images to appear more life-like. Current improvements using LED backlighting are bringing the available color array closer to the human eye’s perception range.
• Environmentally friendly – The significantly lower power requirements of LEDs result in reduced air pollution from carbon emissions. The longer life span of saves maintenance costs by being replaced less often. In addition, LEDs do not contain mercury and thus are not only easier and less expensive to dispose of they are safer and leave less of an environmental impact. Even Apple computer began changing to LED backlit display in their efforts to become a “greener apple.”

Though using LEDs in backlighting applications is still more expensive at this time, the benefits are overcoming the cost concerns. The new development in LED materials will also reduce the price in the future. Regardless, the benefits are so strong that the result has been an increased demand for LED use in backlit applications in all sizes. This will significantly boost LED production requirements immediately and into the future. VCC Optoelectronics is happy to provide you with LEDs and LED mounting components for your entire project.  Check out our catalog for LEDs as well as products you will require to complete a successful and innovative PCB design.

From that time until the present day, constant research, testing and developments have taken place to allow some truly unique and amazing uses of LEDs. The inhibitive costs in the first applications have been greatly reduced increasing the logical applications for everyday products. The recent concerns in reduction of energy usage and environmental responsibility completed the circle and LEDs have been touted as the preferred lighting device. Where they were once relegated to single signal usage, seven-segment displays and simple indicators, today the applications are unlimited.

Traffic signals are currently being converted to energy and Co2 reducing LED cluster lights. They are used to light entire rooms as well as their trusty, proven use as signals and indicators. Billboard size video displays are manufactured with LEDs. There are even applications in the clothing industry where safety vest, jackets and head gear are being equipped with LEDs to increase personal protection whether working in a hazardous location or taking an evening jog down the road.

The UK is taking the lead in the implementation of energy busting LEDs for traffic signal and street lighting. London has become the first major city to secure a finance initiative to replace both street and traffic signals throughout the majority of the city. The London Mayor estimates the LED street lights and traffic signals will save the taxpayers up to 25% of their street lighting bill as well as reduce Co2 emissions by 60%.

Clothes are usually designed to be practical or fashionable. Today they are also functioning as true safety gear for the average person as well as field applications engineer. A shirt that lights up at night draws attention much faster than waiting for the head beams of a car or piece of equipment to illuminate a reflective strip. Gloves are being manufactured with LED lights embedded to assist workers and sportsmen. Instead of relying on someone holding a flashlight, the LED gloves will consistently illuminate the work area. Headlamps with LED clusters have been designed and implemented for rock climbers and campers. You then have the copious amount of marketing and personalized visual displays being applied to everything from t-shirts to hats to shoes that flash when you walk.

No matter what unique idea you come up with or what project your challenged to find an answer for, when it comes to lighting, LEDs are the wave of the future.

VCC high-performance Litepipes™ and LEDs are available in a wide variety of sizes, mounting types, colors, power ratings, intensities and wavelengths to meet your every application need. We can also assist you with selection and even the development of custom applications. Our interconnections, standoffs and myriad of other accessories are available in our product catalog.

The first key for maximizing your circuitry and extending the lifecycle of an LED is to correctly size and wire your components. To avoid almost instant burn out, a resistor must be connected in series with LEDs to limit the current.

To calculate the resistor value ‘R’ use the following:

R = (V_S – V_L)/I where:

V_S = Supply Voltage

V_L = LED Voltage

I   = LED Current

Check manufacturer specifications for the applicable LED voltage and current. If the resistor value calculated is not available choose the next larger size to limit the current and protect your LED.

When connecting multiple LEDs it is advisable to wire them in series when possible, as they will share the same current. If parallel connections are to be used, make sure each LED has a resistor in series to limit the current in that leg and protect your device. Always be sure to double-check polarity. While many think the only result of incorrect wiring is a light that doesn’t energize but it is possible to apply a reverse voltage above the typically low reverse breakdown voltage of an LED. This will result in damage to your LED and a reduced lifecycle, if not destruction of the component.

The future opportunities for extending LED life cycles are abundant. I’ve included a couple of the most interesting projects that are closest to completion and implementation.

One of the new developments being researched and tested is using metal-coated silicon wafers. This will reduce costs further and extend the LED life cycle even beyond current abilities. The Applied Physics Letters journal published a study by Purdue Engineers regarding current silicon-based research trials. A reflective metal coating is applied to a silicon wafer. The new metal coating is a thin, reflective layer of zirconium nitride.

Currently, when the LED emits light, that light is emitted in both the up and down directions. The reflective metal coating limits the light lost in the downward direction. This will reduce the LED duty cycle and allow an extended life.

Another method of operating LED circuits through manipulation of the gain control and duty cycle is currently seeking a patent. The higher gain control in this technique results in a duty cycle of less than 100%. This extends LED life by essentially slowing the aging process. This process also includes end-of life predictions for your LED device or entire lighting assembly. Being able to predict and replace LEDs during scheduled maintenance times reduces facility cost and downtime of equipment.

There are many other research projects in place to improve the life cycle and efficiency of light emitting diodes. A variety of these use IC chips for circuit control while others employ new multi-chip technologies.

With copious amounts of research time and money being dedicate to improving the current benefits of LED usage, this is a new and exciting time for this field. Research efforts to further prolong LED life will once again bring new life to this device and expand its use to unknown limits.

Implementing any type of explosive activity is monitored and regulated by the EOD (Explosive Ordinance Disposal). Extreme caution and supervision must always be the first consideration. Specially designed equipment must be precise and easy to read. Hazardous operations may generate adrenaline but operators can never forget that there is always a risk to the safety, lives and property around them.

Blaster One Control Unit

Blaster One EOD designs and manufactures electronic devices for the bomb-squad and explosives industries. They recently researched and developed the BB-75 Capacitive Discharge Blasting Machine for use by law enforcement, the military and various special effects groups.  This device integrates internal energy testing and a digital galvanometer.

As is often the case with applications that involve extreme hazards, great care and thought was taken in the design. Specially designed LEDs and lens were needed for this project to assure easy to read and accurate readings.

After an extensive review of possible suppliers, Blaster-One selected VCC for several reasons. As stated by Cory Star of Blaster-One:

“VCC had the perfect components, and just as important, they have outstanding customer service. When we queried about a “super-bright” bi-color 3mm LED (that doesn’t exist elsewhere) they told us they had just created one! Needless to say, we promptly placed an order. The current project uses one super-bright white LED-VAOL-3GWY4, one super-bright bi-color LED-VAOB-3GRGE4-C, one yellow Fresnel lens-SMB200YTP, and one clear Fresnel lens-SMB200CTP.

Mr. Gregg Johnson and Mr. Mark Baker took extra concern in finding me the right components, and providing many samples. We will continue to choose VCC for all of my opto-electronic components now, and in the future – and I sincerely recommend them to anyone looking for such.”

VCC is devoted to producing highly technical and precise devices for every application and was pleased to provide the LEDs and lenses for this important project. VCC has taken a pro-active role in encouraging our clients to achieve their best by providing ours daily.

In that interest, VCC presents its Design Award to Blaster-One EOD Equipment for their dedication to excellence in research and development in a field demands only the best.

Additional information about Blaster-One EOD Equipment can be found at www.blasterone.com

The use of LEDs, however, is growing as the benefits both in energy consumption and cost savings are realized. Newer applications include traffic lighting, exit signs, TV’s, watches, home fixtures and even Christmas light displays. These applications are achieved by clustering large amounts of LED’s into one housing and provide many benefits over previous lighting options.

A current goal of most organizations is to reduce their carbon footprint and become more environmentally responsible about consuming resources. Implementing LEDs in new and creative ways can reduce emissions of CO₂ and also provide payback in longer life and lower power bills.

In buildings and renovations where LEED (Leadership in Energy and Environmental Design) certification is desired; using LED lighting on exit signs, elevator indicator lights, room lighting and all possible applications will help meet the required reductions for energy use and consumption.

The environmentally green benefits of LED usage include but are not limited to the following:

• Extended Life Cycle: LED bulbs last up to ten times longer than compact fluorescent bulbs and far longer than typical incandescent bulbs.

• High Efficiency: LEDs use between 1/3 and 1/30 the amount of energy of CFL and incandescent lamps. An LED being a solid-state device also lasts approximately ten times longer than the other options available. This saves on maintenance and replacement costs.

• Durability: Unlike other lamp types, LEDs do not have internal filaments that can be damaged or broken in the same circumstances in which another bulb type would be need replacement. Since they are solid LEDs hold up much better to jarring or an occasional bump.

• Reduced Heat Generation: LED applications will produce less heat than other bulb types, thus requiring less cooling in the system.

• Safe Disposal: Unlike compact fluorescents, which contain mercury or the old incandescent bulb that breaks into shards of glass, the LED can simply be removed and thrown away. No Biohazards or cut fingers here!

• Lower Carbon Footprint: Led usage can reduce your carbon footprint by close to 60% over other bulb types.

• Cost Effectiveness: LEDs for circuit board and signaling applications are inexpensive to implement. The cost for LED clusters is slightly more to purchase initially but the power savings over time and the long life of the lamps allow you to see a return on your investment in a short period of time.

• Variety of Use: The variety of uses for LEDs is endless. The ability to quickly modulate allows LEDs to be used with fiber optics and free space optic cabling systems where normal bulb types cannot be implemented. They can also be used in combination with phototransistors or diodes to provide circuit isolation. This is especially important for medical applications. The infrared abilities of LEDs allow them to be used in many remote applications from your computer mouse to emergency communications equipment.

• Lower Machine Power Usage: LEDs can be used as machine vision systems. For applications such as process lines that require bright illumination and barcode scanners currently using laser lighting; an LED will reduce power consumption when used in place of other lighting types.

By simply taking another look at your applications and implementing LED strategies, you can see payback in your power bill, receive certifications for being conservation leaders and be environmentally responsible at the same time.

Jim Albritton, a VCC Sales Representative explained, “For Mesa Boogie, aesthetics are very important. The indication products offered by VCC’s competitors just didn’t provide the clean look and feel that Mesa Boogie was looking for.”

Find more information about Mesa Boogie and its products here.

Following this success, Neato Robotics approached VCC with another time-sensitive request: to provide a custom Bi-Color high-bright LED for its product. VCC once again met the delivery demands on time and exceeded Neato’s expectations in overall light output performance.

For more information on Neato Robotics, visit www.neatorobotics.com.

VCC was one of a few select suppliers that were invited to attend the 2009 Allied Electronics Expo in Ft. Worth Texas. Expo is where Allied salespeople and supplier representatives come together to learn from each other and discuss new ways to find more customers, deepen existing customer relationships, and increase sales.

Allied has a strong commitment to build lasting relationships with its customers and this clearly showed during Expo. “In Allied you have a company that walks the walk,” said Mark Baker, National Sales Manager of VCC and Expo attendee. He continued, “whether it was a conversation with a salesperson or listening to a heartfelt speech from the President, you can’t help but feel the passion that Allied brings to the table.”

VCC looks forward to continued growth in its partnership with Allied.