Honourtek Delux COB Reliability Notes

Transcription

1 Honourtek Delux COB Reliability Notes 1.0 Introducation Honourtek, Inc.LED COB family of products for commercial lighting and residential lighting market provides a stable performance, high performance, low cost solid state lighting solutions. These products will be LED products of high efficiency, energy saving, long life and other advantages and many traditional light source of the light output level. Honourtek, Inc. LED COB series products through a series of rigorous reliability tests, including endurance testing, environmental testing and mechanical testing, etc.. The serious project based on the JEDEC established standard semiconductor test method. In addition, Honourtek according to industry standards IES-LM-80 of lumen maintenance test. C opy right 2015 H ON OU R TEK, I NC. ALL RI GH TS R ESER VED Preston Road, Dallas, TX USA Page 1 of 13

2 Table of Contents Page 1.0 Introduction Honourtek COB LED series product reliability Lumen Maintenance Projections For Honourtke COB LEDs Company profile Team introduction 6 Page 2 of 13

3 2.0 Honourtek COB LED series product reliability Honourtek COB LEDs are designed to ensure high reliability over a wide range of operating and environmental conditions. The construction of the COB LEDs includes an array of high power InGaN LED die bonded onto an aluminum substrate and encapsulated in a proprietary phosphor compound. Cob led use InGaN LED chip with high stability, in 140 C junction temperature and single chip over 350mA current situation of more than hours of life testing, only negligible output power loss. Honourtek COB LEDs demonstrate industry leading thermal resistance values ranging from 2.5 C/W to as low as 0.2 C/W.The low thermalresistance ensures that the junction temperature of the LED die is maintained at a minimum level thereby maximizing reliability. Use high reliability encapsulation and conversion materials. Redundant wire bonds ensure high reliability in harsh environmental conditions. a very gradual decrease of light output over operating lifetime. COB LED do not typically fail in a catastrophic manner in which the products fail to emit light under normal operating conditions. Honourtke havs conducted extensive product qualification testing to ensure that its LED Array products do not suffer from defects which may cause infant mortality. A comprehensive set of in process and production monitors are in place to ensure product reliability. Accelerated degradation or catastrophic failure of a LED Array may result from inappropriate handling or assembly procedures,the use of excessive drive currents of inadequate thermal management. Product reliability requires comformance to the specification limits pulished in the data sheet and adherence to the assembly, handling and system design recommendations published in the Application Notes. Page 3 of 13

4 3.0 Lumen Maintenance Projections For Honourtke COB LEDs Honourtek cob LED product series in the forward current rating test run of hours, can still provide an average of more than 70% of the luminous flux maintenance factor prediction. The performance is assumed to constant current condition, the heat dissipation shell temperature is not more than 70 C. The predictions based on the package test data, semiconductor chip reliability data, the understanding of the mechanism of the aging mechanism of the package and the long-term observation of chip technology performance data. At the same time, to achieve the luminous flux maintenance rate, also necessary to carry out observation and tracking design limit Comparison of the use of heat flux to maintain body temperature and substrate temperature prediction of solder junction. Honourtek has maintained industry-leading luminous flux maintenance rate. The case temperature is 65 C for flux predict maintenance, because the parameters in the lighting system is easy to measure Other industries led packaging companies to provide more predictions based on the chip junction temperature, the lighting system and enterprise application has little significance, because the node temperature cannot be measured only by technology obtained. Chip PN node temperature is always higher than the shell temperature. In the comparison of luminous flux maintenance test, necessary guarantee under the same conditions. We suggest that compared with respect to maintain flux and temperature prediction of shell. Figure 1 compares the Honourtek cob LED array structure and typical mounted in a metal core printed circuit board (MCPCB) single chip high power LED. Please note that the large chip high power LED heat dissipation pathway is significantly more than the LED COB series products. Page 4 of 13

5 Honourtek COB LED High Power LED Figure 1 LED COB and high power LED thermal path level chart Hypothesis Die =R1 ; Die attach= R2; Substrate=R3; Die =R1 ; Die attach= R2; Package=R3;Package attach=r4; Substrate=R5 The junction temperature (Tj) is determined by the shell temperature (Tc), the power consumption (P), and the thermal resistance (Rth) of the LED case and the substrate or the MCPCB substrate: Tj = Tc + (P*Rth) Hight Power LED Tj=Tc+P*(R1+R2+R3+R4+R5) R1+R2+R3= Thermal resistance of high power housing R4+R5 =MCPCB And the thermal resistance of the interface between MCPCB and LED Although MCPCB is a good conductor, the increment of the substrate and the substrate interface is very considerable. The thermal resistance range of the typical substrate solution is 2 C/W to 5 C/W, which is applied to the thermal resistance of the high power housing to calculate the total thermal resistance of the whole lighting system. In addition, it is important to evaluate the performance of the whole system to compare the performance of different LED products. Page 5 of 13

6 4.0 Company profile Honourtek, Inc. is headquartered in Dallas, Texas, with R & D center in Silicon Valley, focus on LED market segmentation study about color and intelligent lighting device research and development; core team is composed from a number of top led company veteran Silicon Valley, positioning highend commercial and residential lighting LED application solutions provider, is committed to in the development and manufacture of high-quality high brightness, light color of LED devices, with a series of LED devices R & D equipment and reliability test equipment. Which LED COB with the world's leading design and the industry's highest level of color indicators, domestic and international wellknown brands of commercial lighting and home lighting components strategic suppliers. The company has a strong ability to innovate, has applied for more than 20 patents, including the United States a number of invention patents and international patents. 5.0 Team introduction Honourtek, Inc. has a core senior US led technical experts and high-tech enterprise top management team. Team members have an average of 15 years of more high-end LED R & D and manufacturing experience. Page 6 of 13

7 Figure 1: Array Features Solder Pads Yellow phosphor Lighting Emitting Surface ( LES) Radial die configuration improves lumen density and beam control Polarity symbols Radial die configuration improves lumen density and beam control 3.0 General Handling Delux COBs are designed for specific handling procedures. Prior to any handling, be advised devices while robust may be damaged by high levels of static electricity. Training in handling static sensitive devices should be observed Devices are made to be lifted, or carried with tweezers on two adjacent corners. See Figures below. At no time should the devices be handled by or should anything come in contact with the yellow ring area. This is a coating to protect electrical connections. If these are connections are damaged the device could fail. In addition, the ring frame itself should not be used for moving, lifting or carrying the device. Also do not attach any optics or mechanical holders to the ring as it is not capable to handle the mechanical stress. Page 7 of 13

8 4.0 Manual Handing Do not touch the lens with fingers. Do not push on the lens. When using tweezers to handle Delux family LEDs, do not touch the lens with the tweezers. 5.0 Soldering Delux COBs Honourtek recommends wires are attached prior to mounting device to a heat sink. If mounted, entire heat sink needs to be heated Honourtek recommends the device be placed on a hot plate/surface at 150 C. Using a 300 soldering iron, tin the pads with SAC305 flux-core solder wire. Strip and tin 18 AWG wire with SAC305 flux-core solder wire. Solder wire to pad while keeping the device on the 150C hotplate. Remove the soldering iron from the device, then let the device sit for several seconds. Page 8 of 13

9 Lift the device off of the hotplate and place it on a surface to cool. Solder Shielding Do not allow any solder to contact the yellow light emitting surface or surrounding retaining ring as this can seriously damage or destroy the device. If there is concern about containing the solder to the solder pads then a solder shield may be used to protect the sensitive areas of the COB. 6.0 Chemical compatibility The resin material used to enclose the LED die can getter hydrocarbons from the environment. For this reason, certain compounds are not recommended for use in a system or around the LED. Many companies have done studies to demonstrate chemical compatibility with a wide range of compounds that can be used to build a luminaire or light fixture/housing. A partial list of chemicals that can cause issues is included Acetates Acetic acid Acrylates Aldehydes Aldehydes Amines Benzene Common Chemicals Know To Adversely Affect the Device Ketones Liquid hydrocarbons Phosphoric acid Potassium hydroxide Siloxanes, fatty acids Sodium Hydroxide Sulfur compounds Cl, F,or Br containing compounds Dienes, Ethers Sulfuric Acid Nitric Acid Toluene Xylene Hydrochloric Acid 7.0 TIM material (pending reliability analysis M. Weig S.Scolmine) Delux COBs are design for use with proper heat sinking to regulate the device temperature Proper heat sinking starts with proper thermal interface material or TIM. It is always recommended to use some type of TIM material between the Delux device and the adjacent heat sink surface. Care should be taken to adequately match the surface size of the heat sink to the Delux COB. While a larger surface area for the heat sink is acceptable in most situations, a smaller size is almost never a good design. Please refer to our list of partners to find companies that specialize in heat sink design and construction Page 9 of 13

10 8.0 Electrostatic Discharge (ESD) Protection Delux COBs can suffer extensive and permanent damage due to electrostatic discharge (ESD) that could potentially occur as a result of shipping, handling, and assembly. The following ESD protection guidelines should be used at all times when working with Delux COBs. Storage: Delux products should be stored in their containers placed inside closed ESD shielding bags. Assembly: Individuals handling Delux COBs for the purposes of assembly should be trained in ESD protection practices. Assemblers should maintain constant conductive contact with a path to ground by means of a wrist strap, ankle straps, mat or other ESD protection system. When transporting the devices from one assembly area to another, ESD shielded carts and carriers should be used. 9.0 Compatibility with Reflectors and Other Secondary Optics Delux COB s are designed so that they may be used in conjunction with many commercially available reflectors. No portion of a reflector or secondary optic should contact the yellow resin LES or LES surround frame ring. Reflectors and secondary optics should not interfere with the thermal path between the core board, TIM, and heat sink. For more details related to optical performance of Delux COB s with reflectors, diffusers and other secondary optics, refer to application note APN-XXXX 10. Thermal Interface and Heatsinking The aluminum core board of Delux COB arrays is not by itself sufficient for heat sinking the device. Delux COB arrays should always be operated in conjunction with a means of dissipating enough heat energy so that the device remains within the recommended junction temperature and operating temperature. A thermal interface material (TIM) should be used at all times in conjunction with the heat sink and Delux device. The TIM should maintain continuous contact with the entire back portion of the AL core board and should like-wise be in continuous contact with the heat sink. For a list of compatible TIMs see APN Design Guidelines and Ecosystems for Delux COB Arrays. Caution: The front surface and yellow resin LES gets very hot during operation. Nothing should be in contact with this area of the device. 11. Thermal Interface materials list Manufacturer Part Number Type Description Performance 3M 8805 Arcylic 3M 5590h Arcylic Thermally conductive adhesive transfer Thermally conductive acrylic interface pad Excellent GrafTech egraph HiTherm Graphite Flexible graphite Good Page 10 of 13 Good

11 GrafTech egraph HiTherm Adhesive Berquist Liqui-form 2000 GREASE Arctic Silver Arctic Silver 5 GREASE Flexible graphite with adhesive Shearthinning,conformable High Density Polysynthetic Silver Thermal Compound Good Excellent Excellent Panasonic PGS Graphite+Acrylic Thermal Graphite Sheets Excellent Omega OmegaTHERM GREASE Rathburn 8805 Graphite+Adhesive High Temp Thermally Conductive Paste Thermally Conductive Transfer Pad Excellent Good Rathburn Graphite +PET Thermally Conductive Transfer Pad Good 12. Notes on Delux family led connectors A number of firms have developed connectors to simplify the mechanical and electrical attachment of Delux family LEDs. The following firm are interconnect solution providers. Just find connector compatible with X 17.85(les 12mm) and 15.85mm X 15.85mm (les 9mm) COB dimension. Page 11 of 13