View AB115_8995729.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

luxeon cob and luxeon cob with crispwhite technology assembly and handling information scope the assembly and handling guidelines in this application brief apply to the following luxeon cob products (part numbers are listed in section 1.1): luxeon cob core range (gen 1) luxeon cob with crispwhite technology luxeon cob core range (gen 2) luxeon cob with crispwhite technology (gen 2) luxeon cob core range (gen 3) luxeon stylist series luxeon cob core range C high density luxeon cob core range (gen 4) in the remainder of this document the term luxeon cob emitter refers to any product in the luxeon cob emitters listed above. introduction this application brief addresses the recommended assembly and handling procedures for the luxeon cob emitters. these emitters deliver high efcacy and quality of light for distributed light source applications in a compact les array. proper assembly, handling, and thermal management, as outlined in this application brief, ensure high optical output and reliability of these emitters. illumination AB115 luxeon cob and luxeon cob with crispwhite technology application brief ?2018 lumileds holding b.v. all rights reserved.
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 2 table of contents scope 1 introduction 1 1 component 3 1.1 description .......................................................................... 3 1.2 optical center ....................................................................... 4 1.3 handling precautions ................................................................. 4 1.4 cleaning ............................................................................ 4 1.5 electrical isolation .................................................................... 4 1.6 mechanical files ...................................................................... 4 1.7 soldering ............................................................................ 4 1.8 design resources: ecosystem for luxeon cob .......................................... 4 2 assembly process 7 2.1 introduction ........................................................................ 7 2.2 solder-less connector assembly guideline .............................................. 9 2.3 direct attachment of luxeon cob to a heat sink ........................................ 9 part 1 make electrical connections to luxeon cob: ....................................... 9 part 2 attach the luxeon cob to the heat sink: ......................................... 10 3 thermal management 10 3.1 thermal interface materials (tim) selection ............................................ 10 3.2 heat sink .......................................................................... 12 3.3 temperature probing and characterization ............................................. 12 3.4 thermal measurements .............................................................. 12 supplies and equipment ................................................................ 13 thermocouple mounting procedure ...................................................... 13 4 packaging considerationschemical compatibility 14
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 3 1. component 1.1 description the luxeon cob emitter consists of an array of led chips which are mounted onto a metal-core printed circuit board (mcpcb) to facilitate assembly and handling. the mcpcb is made out of aluminum to ensure a good thermal path between the leds and the heat sink on which the luxeon cob is mechanically mounted. the mcpcb of luxeon cob emitters contain 2 relief cuts on opposing corners for alignment with mounting screws while luxeon cob 1211, 1216, 1321 and 1825 emitters have 2 mounting holes instead of relief cuts. the led array is covered with a phosphor silicone mixture to enhance light uniformity and to shield the chip array from the environment. luxeon cob emitters include a transient voltage suppressor (tvs) chip under the silicone to protect the emitter against electrostatic discharge (esd). the backside of the mcpcb contains a 2d barcode which includes a unique serial number for each emitter. luxeon cob emitters come in various form factors in order to meet diferent performance specifcations. figures 1a, 1b and 1c summarize the key dimensions and thermal characteristics for each luxeon cob emitter confguration. luxeon cob with crispwhite technology devices have all of the same physical features and dimensions as their standard counterparts. the table below lists the part numbers covered in this application brief. luxeon co b gen 1 luxeon cob 1202s (l2c1-xxxx120206axx) luxeon cob 1202 (lhcx-xxxx-1202) luxeon cob 1203 (lhcx-xxxx-1203) luxeon cob 1204 (lhcx-xxxx-1204) luxeon cob 1205 (lhcx-xxxx-1205) luxeon cob 1208 (lhcx-xxxx-1208) luxeon cob 1211 (lhcx-xxxx-1211) luxeon co b crispwhite luxeon cob 1202crsp (l2c1-xxxx120206xcx) luxeon cob 1202crsp (lhc2-xxxx-1202crsp) luxeon cob 1203crsp (lhc2-xxxx-1203crsp) luxeon cob 1204crsp (lhc2-xxxx-1204crsp) luxeon cob 1205crsp (lhc2-xxxx-1205crsp) luxeon cob 1208crsp (lhc2-xxxx-1208crsp) luxeon cob 1211crsp (lhc2-xxxx-1211crsp) luxeon co b gen 2 luxeon cob 1202s (l2c2-xxxx1202e06xx) luxeon cob 1202 (l2c2-xxxx1202e09xx) luxeon cob 1203 (l2c2-xxxx1203e09xx) luxeon cob 1204 (l2c2-xxxx1204e13xx) luxeon cob 1205 (l2c2-xxxx1205e13xx) luxeon cob 1208 (l2c2-xxxx1208e15xx) luxeon cob 1211 (l2c2-xxxx1211e19xx) luxeon cob 1216 (l2c2-xxxx1216e23xx) luxeon co b crispwhite gen 2 luxeon cob 1202crsp (l2c5-xxxx1202e6cx) luxeon cob 1202crsp (l2c5-xxxx1202e09cx) luxeon cob 1203crsp (l2c5-xxxx1203e13cx) luxeon cob 1204crsp (l2c5-xxxx1204e13cx) luxeon cob 1205crsp (l2c5-xxxx1205e13cx) luxeon cob 1208crsp (l2c5-xxxx1208e15cx) luxeon cob 1211crsp (l2c5-xxxx1211e19cx) luxeon co b gen 3 and stylist series luxeon cob 1202s (l2c5-xxxx1202e06xx) luxeon cob 1202 (l2c5-xxxx1202e09xx) luxeon cob 1203 (l2c5-xxxx1203e06xx) luxeon cob 1204 (l2c5-xxxx1204e13xx) luxeon cob 1205 (l2c5-xxxx1205e13xx) luxeon cob 1208 (l2c5-xxxx1208e15xx) luxeon cob 1211 (l2c5-xxxx1211e19xx) luxeon cob 1216 (l2c5-xxxx1216e23xx) luxeon cob 1812 (l2c5-xxxx1812g2300) luxeon cob 1321 (l2c5-xxxx1321e2900) luxeon cob 1825 (l2c5-xxxx1825g3200) luxeon co b high density luxeon cob 1202hd (l2c5-xxxx1202eh6xx) luxeon cob 1204hd (l2c5-xxxx1204e09xx) luxeon cob 1205hd (l2c5-xxxx1205e11xx) luxeon co b gen 4 luxeon cob 1203 (l2c5-xxxx1203f09xx) luxeon cob 1204 (l2c5-xxxx1204f13xx) luxeon cob 1205 (l2c5-xxxx1205f13xx) luxeon cob 1208 (l2c5-xxxx1208f15xx) luxeon cob 1211 (l2c5-xxxx1211f19xx) luxeon cob 1216 (l2c5-xxxx1216f23xx)
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 4 1.2 optical center the optical center coincides with the mechanical center of the luxeon cob emitter. optical rayset data for the luxeon cob emitters are available upon request. 1.3 handling precautions the luxeon cob emitter is designed to maximize light output and reliability. however, improper handling of the device may damage the silicone coating and afect the overall performance and reliability. in order to minimize the risk of damage to the silicone coating during handling, the luxeon cob emitter should only be picked up from the side of the package. 1.4 cleaning the luxeon cob emitter should not be exposed to dust and debris. excessive dust and debris may cause a drastic decrease in optical output. in the event that a luxeon cob emitter requires cleaning, frst try a gentle swabbing using a lint-free swab. if needed, a lint-free swab and isopropyl alcohol (ipa) can be used to gently remove dirt from the silicone coating. do not use other solvents as they may adversely react with the luxeon cob package. for more information regarding chemical compatibility, see section 4. 1.5 electrical isolation the aluminum substrate of the luxeon cob emitter is electrically isolated from the led cathode and anode. 1.6 mechanical files mechanical drawings for the luxeon cob emitter are available upon request. 1.7 soldering luxeon cob emitters are designed to be mechanically secured onto a heat sink. electrical wires may have to be soldered onto the electrical pads. for detailed assembly instructions, see section 2. 1.8 design resources: ecosystem for luxeon cob design tools and compatible components can be found at: lumileds.com/designtools . registration is required to access this website. dimensions key for luxeon co b 1202C1208 aabbf1205 aabbf1204 d ts emitter part number r th j-s (k/w) outer dimensions distance d : m2 screws distance d : m3 screws luxeon cob 1202s l2c1-xxxx-120206xxx 1.55 15mm x 12mm 17.98mm 19.78mm l2c1-xxxx-120206xcx 1.85 l2c2-xxxx-1202e06xx 1.27 l2c5-xxxx-1202e06cx 1.85 l2c5-xxxx-1202e06xx 1.41
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 5 figure 1a. mechanical and thermal characteristics for luxeon cob 1202C1208 emitter confgurations. dimensions key for luxeon co b 1202C1208 aabbf1205 aabbf1204 d ts emitter part number r th j-s (k/w) outer dimensions distance d : m2 screws distance d : m3 screws luxeon cob 1202 lhcx-xxxx-1202 1.49 19mm x 16mm 24.55mm 25.28mm l2c2-xxxx-1202crsp 1.60 l2c2-xxxx-1202e09xx 1.49 l2c5-xxxx-1202e09cx 1.60 l2c5-xxxx-1202e09xx 1.20 l2c5-xxxx-1202eh6xx 1.27 luxeon cob 1203 lhcx-xxxx-1203 1.00 l2c2-xxxx-1203crsp 1.20 l2c2-xxxx-1203e09xx 1.00 l2c5-xxxx-1203e09cx 1.20 l2c5-xxxx-1203e09xx 0.95 l2c5-xxxx-1203f09xx 0.72 luxeon cob 1204 lhcx-xxxx-1204 0.80 24mm x 20mm 30.95mm 32.28mm l2c2-xxxx-1204crsp 0.95 l2c2-xxxx-1204e13xx 0.80 l2c5-xxxx-1204e13cx 0.95 l2c5-xxxx-1204e13xx 0.83 l2c5-xxxx-1204e09xx 0.77 l2c5-xxxx-1204f13xx 0.57 luxeon cob 1205 lhcx-xxxx-1205 0.67 l2c2-xxxx-1205crsp 0.82 l2c2-xxxx-1205e13xx 0.67 l2c5-xxxx-1205e13cx 0.82 l2c5-xxxx-1205e13xx 0.62 l2c5-xxxx-1205e11xx 0.49 l2c5-xxxx-1205f13xx 0.48 luxeon cob 1208 lhcx-xxxx-1208 0.43 l2c2-xxxx-1208crsp 0.75 l2c2-xxxx-1208e15xx 0.43 l2c5-xxxx-1208e15cx 0.75 l2c5-xxxx-1208e15xx 0.55 l2c5-xxxx-1208f15xx 0.37
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 6 dimensions key for luxeon co b 1211, 1216 and 1812 emitter part number r th j-s (k/w) outer dimensions distance d : m2 screws distance d : m3 screws luxeon cob 1211 lhcx-xxxx-1211 0.25 28mm x 28mm na 32.28mm l2c2-xxxx-1211crsp 0.40 l2c2-xxxx-1211e19xx 0.25 l2c5-xxxx-1211e19cx 0.40 l2c5-xxxx-1211e19xx 0.29 l2c5-xxxx-1211f19xx 0.27 luxeon cob 1216 l2c2-xxxx-1216e23xx 0.18 28mm x 28mm na 32.28mm l2c5-xxxx-1216e23xx 0.19 l2c5-xxxx-1216f23xx 0.15 luxeon cob 1812 l2c5-xxxx1812g2300 0.20 28mm x 28mm na 32.28mm figure 1b. mechanical and thermal characteristics for luxeon cob 1211C1216 emitter confgurations. aabbf1211 d ts dimensions key for luxeon co b luxeon 1321 and 1825 emitter part number r th j-s (k/w) outer dimensions distance d : m2 screws distance d : m3 screws luxeon cob 1321 l2c5-xxxx1321e2900 0.14 38mm x 38mm na 45.25mm luxeon cob 1825 l2c5-xxxx1825g3200 0.09 38mm x 38mm na 45.25mm figure 1c. mechanical and thermal characteristics for luxeon cob 1321 and 1825 emitter confgurations.. xxxx 1 825 d
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 7 2. assembly process 2.1 introduction luxeon cob emitters are designed to be mechanically mounted onto a heat sink with screws, facilitating the design and assembly of retroft and down-light applications. several types of solder-less connectors are currently available for the luxeon cob devices. section 2.2 provides general guidelines in mounting a luxeon cob device to a heat sink with a solder-less connector. a list of luxeon cob compatible clamps can be found on the luxeon eco-system webpage at lumileds.com/designtools . a luxeon cob emitter can also be mounted directly onto a heat sink with m2/m3 screws and electrical wires can be soldered onto the electrical pads, see section 2.3. figure 2. reference dimensions for te 2-2154857-2, a scalable solder-less connector for mounting 8(21rhplhu6hh7(ssolfdlr6shfl4fdlrirughdlohgprxlluxflr
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 8 figure 3. reference dimensions for te 2213130-1 (left) and te 2213130-2 (right) solder-less connector designs for the luxeon cob 1204, 1205 and 1208 emitters. all dimensions are in millimeters. in addition to the te connectivity clamps shown in is this example, there are many other solderless connector options available for use with luxeon cob devices. figure 4 shows just a few of these options. for a comprehensive list and more information about luxeon cob compatible clamps, see the luxeon eco-system webpage at lumileds.com/designtools . figure 4: sample of compatible solder-less connectors from various manufacturers.
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 9 2.2 solder-less connector assembly guideline figure 2 through figure 4 show various solder-less connector solutions available for the luxeon cob emitters. while there are multiple connector solutions, the assembly process is essentially the same and consists of four steps; heat sink preparation, thermal interface material (tim) application, led/ connector assembly and wire attachment. 1. prepare the heat sink according to the connector manufacturers recommendations. this usually consists of drilling clearance holes for locating pins and drilling and tapping threaded holes at the screw locations. once this is done, the heat sink should be cleaned thoroughly to remove any trace of tapping lubricants and metal shavings. 2. tim be should be applied to the back of the luxeon cob emitter or to the heat sink in preparation for the next step. application method is dependent upon the type of tim selected. for more details regarding suitable tims, see section 3.1 3. mounting of the luxeon cob is dependent upon the type of solder-less connector chosen. for some types of solder-less connector solutions, such as te 2213130-1 and te 2213130-2, the luxeon cob device must be snapped into place in the solder-less connector before placing the assembly onto the heat sink. for other types of solder-less connectors, place the luxeon cob onto the heat sink, align and drop the solder-less connector into place. install mounting screws to the torque specifed by the solder-less connector manufacturer. 4. the fnal step is to install wire leads to the connectors as recommended by the manufacturer and power up the device to test the connections. 2.3 direct attachment of luxeon cob to a heat sink attaching a luxeon cob emitter directly onto a heat sink is a two part process. part 1 make electrical connections to luxeon cob: follow these steps to attach the electrical wires to the luxeon cob emitter: please note: the phosphor layer should be covered when wires are soldered to the luxeon cob emitter. please ensure that no solder fux or debris lands on the phosphor layer because this may impact the long-term performance of the luxeon cob emitter. 1. prepare the electrical wires: a. cut the wires to size. b. strip a few millimeters of insulating material from the ends of the wires. c. pre-tin the wires with a small amount of solder. 2. prepare the luxeon cob emitter: a. clean the electrical pads of the luxeon cob emitter with a lint-free swab and isopropyl alcohol to remove any debris or particles. b. the substrate of the luxeon cob emitter is designed to dissipate heat quickly. this may make it difcult to get the temperature of the electrical pads to a point where the solder will refow. therefore it is important to place the luxeon cob emitter on a thermally insulating surface. alternatively, place the luxeon cob emitter on a pre-heated hot plate set to 100c/212f, not to exceed 120c/250f. c. place the tip of the soldering iron on the electrical pad, apply solder and allow it to wet the electrical pad. do not place the soldering iron on the electrical pad for more than 3 seconds to prevent any damage to the luxeon cob emitter. 3. solder the pre-tinned wires to the pre-tinned electrical pads: a. place the pre-tinned luxeon cob emitter on a thermally insulating surface. alternatively, place the luxeon cob emitter on a pre-heated hot plate set to 100c/212f, not to exceed 120c/250f. b. place the pre-tinned wire on the pre-tinned electrical pad. c. place the tip of the soldering iron on the electrical pad and allow the solder to refow around the wire. do not place the soldering iron on the electrical pad for more than 3 seconds to prevent any damage to the luxeon cob emitter. if a solder joint cannot be established within this time, allow the luxeon cob emitter to cool before reapplying the heat. d. remove the soldering iron and allow the solder to joint to cool.
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 10 part 2 attach the luxeon cob to the heat sink: 1. prepare the heat sink a. ensure that the heat sink surface is clean and fat ( 25um), with no crowns or peaks in the mounting area; crowns or peaks on the heat sink surface may adversely impact the thermal conductance between the luxeon cob emitter and the heat sink. b. drill and tap two m2 or m3 screw holes according to the distances d indicated in figure 1. c. wipe the heat sink surface clean with isopropyl alcohol (ipa). d. apply thermal interface material (tim) onto the heat sink. for more details regarding suitable tims, see section 3.1. 2. place the luxeon cob emitter onto the heat sink and align the screw slots in the substrate with the tapped screw holes in the heat sink. 3. secure the luxeon cob emitter to the heat sink with two m2 or m3 screws. the screw down torque should not exceed 2 in-lb (0.224 n-m). 3. thermal management 3.1 thermal interface materials (tim) selection due to the low thermal resistance of the luxeon cob emitter and its large thermal footprint, a variety of thermal interface materials can be used to thermally connect the emitter to the heat sink (e.g. phase change materials, thermal tapes, graphite sheets). however, tim selection should be made with the following considerations: 1. pump outsome tims will move out of the thermal path during extreme temperature excursions and create voids in the thermal path. these materials should not be used. 2. tim thicknessexcessive thickness of some tims will present an unacceptable thermal resistance even though the thermal conductivity may be high. 3. surface roughnessin order to fll the air gaps between adjacent surfaces, choose the appropriate tim that minimizes the interfacial contact resistance. 4. operating temperaturesome tims perform poorly at elevated temperatures. care should be exercised to select a tim that will perform well under the anticipated operating conditions. 5. out-gassingout-gassing of some tims at design temperatures may produce undesirable optical or appearance qualities (e.g. fogging) in a sealed system. special consideration must be given to limit this efect. 6. clamping forcetims such as thermal tape or pads perform better when the right pressure is applied. screws on corners only may not be suitable for certain tims which require high contact pressure between the substrate of luxeon cob and the heat sink. see figure 2 and figure 3 for more information. table 1 lists several tims that have been tested with luxeon cob. this data is provided for informational purposes only. lumileds cannot guarantee the performance of the listed tims since led operating conditions and long-term performance specifcation will vary with the application design. table 1. list of tim materials that meet the tim considerations outlined in this section. note, though, that the actual shuirupdfhrihh70pdhuldolooghshgrh4dodssolfdlr manufacturer tim arctic silver arctic silver ? #5 graftech graphite sheet 1205 thermalloy inc. thermal joint compound (white)
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 11 figure 5. example of poor tim selection with direct attachment method. clamping pressure causes deformation of the substrate at the edges because of tim hardness. this method requires softer tim types. figure 6. example of a proper match between the tim and attachment method. the clamping pressure in this example is more uniform and is less likely to cause substrate distortion even with harder style tims. table 2. measured luxeon cob junction temperatures for nominal currents and various heat sink confgurations. luxeon co b configuration heat sink information tim t a [c] i f [ m a] t s [c] v f [v] t j [c] mounting method 1202s ohmite sv-led-151e 5 r:3dvvlh graftech graphite 1205 25 200 48 35.8 64.1 screws 1202 ohmite sa-led-151e 5 r:3dvvlh graftech graphite 1205 25 200 47 36.4 57.6 screws 1203 synjet ? par30 cooler 40w 5 r:3dvvlh graftech graphite 1205 25 300 53 35.6 62.3 screws 1203 synjet ? par30 cooler 40w 5 r:fwlh graftech graphite 1205 25 300 39 35.8 48.1 screws 1204 synjet ? par30 cooler 40w 5 r:3dvvlh graftech graphite 1205 25 450 67 36.2 80.4 zhaga clamp 1204 synjet ? par30 cooler 40w 5 r:fwlh graftech graphite 1205 25 450 45 36.5 58.5 zhaga clamp 1205 synjet ? par30 cooler 40w 5 r:3dvvlh graftech graphite 1205 25 600 91 36.0 102.9 zhaga clamp 1205 synjet ? par30 cooler 40w 5 r:fwlh graftech graphite 1205 25 600 60 36.3 72.1 zhaga clamp 1208 synjet ? par30 cooler 40w 5 r:fwlh graftech graphite 1205 25 900 72 35.9 88.4 zhaga clamp 1211 synjet ? spot light cooler 60w 5 r:fwlh graftech graphite 1205 25 1200 45 35.9 55.8 zhaga clamp 1216 synjet ? spot light cooler 70w 5 r:fwlh graftech graphite 1205 25 1800 75.3 35.0 86.6 zhaga clamp
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 12 3.2 heat sink luxeon cob emitters must be mounted onto a properly sized heat sink in order to keep the junction temperature below the maximum acceptable junction temperature specifed in the datasheet. for reference, table 2 summarizes the approximate junction temperature which was measured for each standard luxeon cob emitter at nominal drive currents on a passive or actively cooled heat sink. the results in this table were obtained in an open environment with an ambient temperature of approximately 25c. all nuventix synjet ? coolers were confgured for maximum cooling in dc mode and were placed on a fat horizontal surface. actual results may vary with orientation, ambient temperature, and thermal interface material between the luxeon cob emitter and the heat sink. please note, these test were conducted with standard luxeon cob devices. luxeon cob devices with crisp white technology have slightly higher thermal resistance values. therefore, slightly higher junction temperatures can be expected when operating under the same conditions as listed in the table. 3.3 temperature probing and characterization the typical thermal resistance r (j-c) between the junction and case for the diferent luxeon cob emitter confgurations are published in the datasheet. with this information, the junction temperature t j can be calculated according to the following equation: t j = t c + r j-c ? p electrical in this equation t c is the case temperature at the bottom of the luxeon cob emitter and p electrical is the electrical power going into the luxeon cob emitter. in typical applications it may be difcult to measure the case temperature t c directly. therefore, a practical way to determine the junction temperature of a luxeon cob emitter is by measuring the temperature t s of a predetermined sensor pad with a thermocouple. each luxeon cob emitter has a circular sensor pad area in the lower right hand corner of the emitter. this sensor pad area is identifed in figure 1. proper thermocouple attachment to the t s or sensor pad area is shown in figure 7. figure 7. the recommended temperature measurement point t s is located on the circular gold pad at lower right hand corner of luxeon cob emitter on the pcb. the thermal resistance r j-s between the sensor pad and the junction of the luxeon cob emitter was experimentally determined. figure 1 summarizes the typical thermal resistance values for each luxeon cob emitter confguration. 3.4 thermal measurements this section describes in detail how to mount a thermocouple onto the luxeon cob emitter in order to determine the junction temperature t j .
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 13 supplies and equipment below is a list of supplies and equipment that is needed for t j measurements: ? type t precision fne wire (0.003 gauge diameter) thermal couple from omega engineering inc. (part number: 5srtc- tt-t-40-36) ? eccobond one component, low temperature curing, thermal conductive epoxy adhesive from emerson and cuming (part number: e 3503-1) or arctic alumina thermal adhesive compound from arctic silver inc. (part number:aata-5g) ? disposable 3cc barrel syringe from efd inc. (part number 5109ll-b) ? disposable 0.016 inner diameter fne needle tip from efc inc. (part number:5122-b) ? kapton tape ? convection oven (for curing of eccobond epoxy) ? thermometer ? magnifying glass or low power microscope (e.g. 5x to 30x) thermocouple mounting procedure 1. familiarize yourself with the manufacturers material safety data sheet (msds) and preparation procedures for the epoxy or adhesive compound. 2. place the thermocouple tip on the sensor pad area t s (see figure 1). the thermocouple must touch the substrate of the luxeon cob emitter to ensure an accurate reading. 3. use kapton tape to secure the thermocouple wire onto the luxeon cob emitter. 4. follow step a or step b below depending on the compound or adhesive that is used to thermally connect the thermocouple to the luxeon cob emitter. a. eccobond thermal adhesive epoxy i. thaw the thermal conductive epoxy per manufacturers recommendations. ii. dispense sufcient epoxy into the 3cc barrel syringe with the fne needle tip. store the balance per manufacturers recommendations. iii. drop a small amount of thermal conductive epoxy just enough to cover the thermocouple tip. iv. cure the epoxy per the manufacturers recommendations. make sure that the oven temperature does not exceed the maximum rated temperature of the luxeon cob emitter. v. let the board cool down to room temperature before starting any measurements. b. arctic alumina thermal adhesive compound i. since this is a two part epoxy system with an approximate pot-life at room temperature after mixing of 3C4 minutes, make sure that proper setup is done to ensure that the epoxy can be dispensed within the pot-life span. ii. after mixing, put the epoxy immediately into the 3cc barrel syringe with the fne needle tip and dispense onto the thermocouple tip. close to the end of the pot-life, it becomes difcult to dispense. iii. alternatively, you can dip the fne needle tip into the epoxy mix and then touch the thermocouple tip to dispense the epoxy via surface tension. iv. cure the epoxy at room temperature (25c) for at least two hours. 5. once the epoxy/compound has hardened, the luxeon cob emitter can be mechanically mounted onto the heat sink as explained in section 2. 6. plug in the thermocouple connector to the thermometer. the thermocouple now measures the temperature t s . 7. connect the power supply to the luxeon cob emitter and power up the emitter with a drive current that corresponds to normal operating conditions. if possible, attach all fxtures (e.g. heat sink, lens and any cover) to closely simulate the actual application environment. 8. record the temperature t s once the luxeon cob emitter stabilizes. this may take several minutes or more depending on the overall design and thermal mass. 9. the junction temperature can then be estimated as follows: t j = t s + r j-s ? p electrical
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 14 4. packaging considerationschemical compatibility the luxeon cob emitter package contains a silicone overcoat to protect the led chip and extract the maximum amount of light. as with most silicones used in led optics, care must be taken to prevent any incompatible chemicals from directly or indirectly reacting with the silicone. the silicone overcoat used in the luxeon cob emitter is gas permeable. consequently, oxygen and volatile organic compound (voc) gas molecules can difuse into the silicone overcoat. vocs may originate from adhesives, solder fuxes, conformal coating materials, potting materials and even some of the inks that are used to print the pcbs. some vocs and chemicals react with silicone and produce discoloration and surface damage. other vocs do not chemically react with the silicone material directly but difuse into the silicone and oxidize during the presence of heat or light. regardless of the physical mechanism, both cases may afect the total led light output. since silicone permeability increases with temperature, more vocs may difuse into and/or evaporate out from the silicone. careful consideration must be given to whether luxeon cob emitters are enclosed in an air tight environment or not. in an air tight environment, some vocs that were introduced during assembly may permeate and remain in the silicone dome. under heat and blue light, the vocs inside the dome may partially oxidize and create a silicone discoloration, particularly on the surface of the led where the fux energy is the highest. in an air rich or open air environment, vocs have a chance to leave the area (driven by the normal air fow). transferring the devices which were discolored in the enclosed environment back to open air may allow the oxidized vocs to difuse out of the silicone dome and may restore the original optical properties of the led. determining suitable threshold limits for the presence of vocs is very difcult since these limits depend on the type of enclosure used to house the leds and the operating temperatures. also, some vocs can photo-degrade over time. table 3 provides a list of commonly used chemicals that should be avoided as they may react with the silicone material. note that lumileds does not warrant that this list is exhaustive since it is impossible to determine all chemicals that may afect led performance. the chemicals in table 3 are typically not directly used in the fnal products that are built around luxeon cob emitters. however, some of these chemicals may be used in intermediate manufacturing steps (e.g. cleaning agents). consequently, trace amounts of these chemicals may remain on (sub) components, such heat sinks. lumileds, therefore, recommends the following precautions when designing your application: ? when designing secondary lenses to be used over an led, provide a sufciently large air-pocket and allow for ventilation of this air away from the immediate vicinity of the led. ? use mechanical means of attaching lenses and circuit boards as much as possible. when using adhesives, potting compounds and coatings, carefully analyze its material composition and do thorough testing of the entire fxture under high temperature over life (htol) conditions.
AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308 ?2018 lumileds holding b.v. all rights reserved. 15 table 3. list of commonly used chemicals that will damage the silicone overcoat of the luxeon emitter. avoid using any of these chemicals in the housing that contains the led package. chemical name normally used as hydrochloric acid acid sulfuric acid acid nitric acid acid acetic acid acid sodium hydroxide alkali potassium hydroxide alkali ammonia alkali mek (methyl ethyl ketone) solvent mibk (methyl isobutyl ketone) solvent toluene solvent xylene solvent benzene solvent gasoline solvent mineral spirits solvent dichloromethane solvent tetracholorometane solvent castor oil oil lard oil linseed oil oil petroleum oil silicone oil oil halogenated hydrocarbons (containing f, cl, br elements) misc rosin flux solder fux acrylic tape adhesive no. e352519
?2018 lumileds holding b.v. all rights reserved. luxeon is a registered trademark of the lumileds holding b.v. in the united states and other countries. lumileds.com neither lumileds holding b.v. nor its afliates shall be liable for any kind of loss of data or any other damages, direct, indirect or consequential, resulting from the use of th e provided information and data. although lumileds holding b.v. and/or its afliates have attempted to provide the most accurate information and data, the materials and services information and data are provided as is, and nei ther lumileds holding b.v. nor its afliates warrants or guarantees the contents and correctness of the provided information and data. lumileds holding b.v. and its afliates reserve the right to make changes without notice. you as user agree to this disclaimer and user agree - ment with the download or use of the provided materials, information and data. a listing of lumileds product/ patent coverage may be accessed at lumileds.com/patents. about lumileds companies developing automotive, mobile, iot and illumination lighting applications need a partner who can collaborate with them to push the boundaries of light. with over 100 years of inventions and industry frsts, lumileds is a global lighting solutions company that helps customers around the world deliver diferentiated solutions to gain and maintain a competitive edge. as the inventor of xenon technology, a pioneer in halogen lighting and the leader in high performance leds, lumileds builds innovation, quality and reliability into its technology, products and every customer engagement. together with its customers, lumileds is making the world safer, better and more beautifulwith light. to learn more about our lighting solutions, visit lumileds.com . AB115 luxeon cob and luxeon cob with crispwhite technology application brief 20180308

▲Up To Search▲

Price & Availability of AB115

	To Download AB115 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .