Application notes: DDR LED module Contents

Transcription

1 Application notes: DDR LED module Contents 1

2 Information Contents and Supports Information and supports Warnings Introductions What is DDR LED module? Driving scheme of DDR LED module How to select the DDR LED module Basic informations Product structure 9 9 Optical design Lumen output property Spectrum Beam shape SDCM Optical Recommnedations Thermal design Thermal conduction theory Junction temperature & T c point How to calculate the junction temp? Thermal management via luminaire Safety design Safety regulation summary Europe USA (North America) Safety recommendations Installation instructions Installation Handling & usage

3 Information and Support Thank you for choosing the Direct driving LED module from American Bright Optoelectronics Corporation. In this application note you will find all the information you need to apply this module into the luminaire. Information and support If you need further information or there s some technical issue, please contact to our agent or mail to our technical support mailbox, we ll reply your question as soon as possible. American Bright support: aboc@americanbrightled.com Phone: (909)

4 Warning Warning: Do not touch the live parts when the module is turned on Do not use damage module Warnings during the design-in of all DDR-LED module into luminaires and manufacturing Design-in phase DDR LED module is semi-finished product which is compliance to the IEC & UL8750:OOQA2. But such safety regulation is belong to the module level safety regulation. Luminaire manufacturers are advised to conform to the international safety standards in luminaire level (IEC Luminaires, UL1598, etc.). American Bright s standard DDR LED module is designed to use an IEC class I luminaire that the luminaire is connected to protective earth. If the luminaire maker wants to use in Class II luminaire, please contact us to see if such model can be used in Class II luminaire which in not connected to protective earth. The luminaire should be constructed in such a way that the DDR LED module (or the integrated parts contacted to the module) cannot be touched by an enduser. Do not apply the overloading of AC voltage in DDR LED module. Make sure all the connection of electrical components is done first before switching on mains. Design-in and manufacturing phase Do not use the unsuitable housings to damage the DDR LED module. Do not drop the DDR LED module or let any object fall onto the LED module because this may damage the 4

5 PCB or LEDs and affect proper functioning of the product. Do not damage the back side thermal insulating tape, because this will cause the high pot testing fail. Make sure all the connection of electrical components is done first before switching on mains. Do not connect or disconnect the cable between the luminaire and the main when mains voltage is connected. Do not use damaged products. 5

6 Introductions What is DDR LED module? DDR LED is the abbreviation of Direct-Drive LED module which means that AC power is directly inputted into the LED module. Conventional Structure of LED module is to use the light engine (DC LED Board) and power module together, shown in Figure 1. Figure 1 LED light engine and Power module Our advanced technology AC direct drive let us be able to use the IC to control the input current when AC power inputting to the LED module, as shown in Figure 2. Figure 2 15W DDR LED module The advantage of such driving technology is 1. AC direct drive, plug then light up 2. No electrolytic capacitor 3. Long life light engine > 50,000 hrs (electrical parts) 4. Integrated to one driver board 5. Designed for safety compliance 6. Environmental friendly ; RoHS compliance 6

7 Driving scheme of DDR LED module AC input based DDR LED driving scheme is similar to the conventional AC light source, such as incandescent. But the lumen output is different from the conventional incandescent bulb because the heating tungsten is continually heating and bright. But the optical output of DDR LED module is followed the AC driving voltage, as shown in Figure 3. Figure 3 Driving scheme of DDR LED module LED light output diagram in the 120Hz AC input driving is shown in Figure 4. LED will be switch off with 120Hz frequency, just as the conventional T8 tube and some fluorescent bulb. The light output will be distinguished by the CMOS camera. There s some specific regulation in some country. But this phenomenon can t be distinguished by human eye. Figure 4 Light output diagram of DDR LED module 7

8 How to select the DDR LED module? 1. Set up the lumen target 2. Define the application and other requirement Lumen / Power consumption Color temperature / CRI Operating temperature / Humidity Target price 3. Calculate the LED quantity and possible efficiency of LED luminaire LED total lumen LED watts LED efficiency Target luminaire lumen Optical loss Thermal loss Luminaire Watts Driver efficiency LED total lumen LED Watts Base on the efficiency and application, there s the different selection of the LED type (small/ Middle / High power). Directional lighting A. Emitter w/ lens B. COB w/ reflector In-directional lighting Tube : Small / middle power LED (>60 o ) Bulb: LED middle / High power Grid fluorescent: small power LED Bulb : COB / Middle power Omni bulb: COB Table 1 Comparison between directional and indirectional If there s not the proper module in our standard module, please contact us for the customization service. 8

9 Basic informations Product structure With Connector Figure 5 Picture of the module Items: 1. LEDs 2. Integrated driving circuit 3. Central screw hole 4. Corner fix hole 5. Connector 6. Part number mark 7. CCT mark 8. Voltage mark With wire Figure 6 Picture of the module 6 Items: 1. LEDs 2. Integrated driving circuit 3. Corner fix hole 4. Electrical wire 5. Insulating encapsulate 6. Part number mark 7. CCT mark 8. Voltage mark 9

10 Backside of DDR LED module 1 Items: 1. Thermal tape Figure 7 Picture of the backside of module Warning: Remember to remove the protection paper of the thermal insulating tape in the back side of the module Specification of the Thermal tape HS-6250(B25) Thickness mm 0.25 Adhesive force T 0 (0 hrs) 4.0 T 24 (24 hrs) 4.6 Thermal conductivity W / m K 0.7 Thermal resistance cm 2 o C/W 3.6 Fire retardency UL94 V0 Isolation strength DC (kv) >10 AC (kv) 4.4 Table 2 the specification of Thermal tape 10

11 Optical design Lumen output property Look at the Optical property table in our specification. Due to the distribution of the single LED light output and the IC Conductor manufacture, there s always the distribution of the lumen output and the AC watts. Because the driving scheme is similar to the conventional AC driving which is AC directly drive, the lumen output is always changed under the different AC input, as the Figure 10 shown below. Figure 8 the relationships of AC Watts and AC voltage input So normally we defined one typical AC input voltage to standardize our specification, such as the table 2. 11

12 Spectrum Two main peaks, blue and green/red is in the spectrum of DDR LED module. Figure 9 spectrum of different Color temperature If there s the different CRI spec or different LED we used, there s different spectrum. Beam shape The regular beam angle of DDR LED module is 120o. Figure 10 beam angle of DDR LED module The beam angle can be modified by different 2 nd optics, such as reflector, lens, etc.. 12

13 Color Consistency (SDCM) The current specification of the DDR LED modules (3000K, 4000K, 5000K, 5700K, 6500K) for color consistency is 4 SDCM at the initiate state(t0). SDCM, Standard Deviation of Color Matching, refers to the size of the Macadam ellipse around the black body locus. If the measurement data is within the ellipse, the light consistency will be good that there s no eye-distinguishable difference from one luminaire to another. 3000K 4000K 5000K Figure 11 SDCM distribution of DDR LED module 13

14 Optical recommendation There s so many different kind of key in the optical design of the optical design of the luminaire, and such kind of the module is normally used in the uniform distributed light output. Normally the secondary optic of such luminaire is diffuser. 14

15 Thermal design Thermal conduction theory Heat will be transfer from Chip to bottom FR4 with Copper through thermal pad of LED and Copper Via by the thermal conduction. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes. So we design the proper path for the heat to transfer from chip to bottom of LED, so we need to choose the proper inter-material to conduct the heat from bottom of LED to bottom of substrate Figure 12 Heat conduction path Figure 13 Cross-section of Heat conduction path From the Figure 10, the cross-section of the heat conduction path, the heat dissipation path is not only vertical thermal conduction but also lateral thermal conduction. Good heat transfer control can provide the better heat dissipation performance 15

16 Junction temperature (Tj) & Tc point Junction temperature is the most important factor of LED. Different life performance will be impacted by different junction temperature. Figure 14 Junction temperature If the thermal dissipation is good enough, the junction temperature will be lower and the lifetime performance will be better. If the junction temperature is higher than 120oC, the LED will decay quickly. How to monitor the junction temperature? You need the measure the Tc point Each DDR LED module has one TC point, which is prepared for monitoring the LED operation temperature and the junction temperature. Figure 15 Tc point in the module You can use the High-temperature thermal conductivity glue (Such as SatlonD-3/606..etc) to fix the thermal couple to the Tc point then measure the temperature. Once you got the Tc temperature measurement data, you can calculate the junction temperature based on the measurement data of the Tc. The details of the calculation method is shown in the page below: 16

17 How to calculate the Junction temperature of LED? Tj,LED = Ts + Rth * PD So the junction temperature should be calculated by the Substrate temperature(t s) and the Thermal resistance of Substrate(R th) Examples: What is the Tj of LED(R th=6 K/W) under 15W 40 o C? Ts = 40 o C, P D =15W, R th =6K/W T j,led = * 15 =130 o C (Normal Tj limitation is 120 o C) How to calculate the Junction temperature of IC? Tj,IC= Ts + Rth,IC * PD So the junction temperature should be calculated by the Substrate temperature(t s) and the Thermal resistance of Substrate(R th) Table 3 Thermal resistance of IC under different AC input Examples: IC IC power consumption R th, IC AC input HM V-220V 15 What is the Tj of LED(R th=6 K/W) under 15W 40 o C? Ts = 40 o C, P D =15W, R th =6K/W T j = * 15 =130 o C (Normal Tj limitation is 110 o C) Warning: Tj must be lower than 110 o C. If the Tj>110 o C, American Bright opto won t be guaranteed the life of LED. 17

18 Thermal management via luminaire As you know, the heat dissipation is one of the most important issue in LED luminaire design. The design of DDR LED module is based on the integration of electrical device and optical device. So the thermal solution still need to be controlled by the luminaire design There s few key point in the thermal design from DDR LED module. 1. Selection of the back plate material. The best thermal design is too use the back plate of luminaire since the most important key of thermal design is to dissipate the heat from LED chip to the air. In the Light source product (such as Led light bulbs, LED light tube, etc), the heat dissipation area is always limits due to the size of the light source. But in the luminaire, the back plate is one large metal plate which is good candidate of thermal media. Common material for the thermal dissipation is listed in the table 4 below: Thermal Thermal Material Conductivity Material Conductivity (W / m k) (W / m k) SiC 490 Nickel Pure 91 Silver 429 Iron_Pure 80 Copper pure 401 Iron_99.75% purity 73 Gold 317 Tin 67 Pure Aluminum 237 Al2O3, sapphire 46 Aluminum_4.5% Cu, 1.5%Mg, 0.6% Mo 177 SiN 16 Tunsten 174 Nickel_80% Ni, 20% Cr 12 Silicon 148 SiO2 1.4 Copper_70% Cu, 30% Zn 110 Table 4 thermal conductivity property of different material To select the proper material is easily to solve thermal issue. 18

19 2. Thickness of the back plate There s vertical and lateral heat conduction in the whole conduction model. The vertical teat conduction is lateral heat dissipation is only few cm if we use aluminum as the thermal media. Because there s three different kind of the heat transfer model, thermal conduction, thermal convection, thermal radiation. Warning: If the user didn t apply the screw to fix the DDR LED module and let the temperature of the PCB is too high, American Bright Opto will not be able to guarantee the life time of the module. Figure 16 Junction temperature 3. Thermal contact For the easily assembly, we use the thermal tape as the thermal media between the DDR LED module and the back plate. For the module with FR4 substrate, we must use the thermal insulator as the thermal media. For the module with the MCPCB, we may use the thermal glue as the thermal media. No matter what kind thermal media we used, we highly recommended the user to add the mechanical parts. FR4 with Thermal tape case: Please refer to the table shown below.we use TC08215Wxx01 with the thermal tape to do some cross test Conditions Thermal tape only Thermal tape and 4 screws hole Thermal glue and 4 screws hole T T stable T T Ta Table 5. Thermal testing data with FR4 with thermal tape So the effect of adding the screws is quite obvious in this case. 19

20 The result to use the thermal glue is much better than the result to use the thermal tape, because the miner gap between the module and back plate is full of the thermal dissipation media. And there s degree gap between the module with the screw and without the screw. No use of the screw to fix the DDR LED module could cause the damage of the light module. Due to the gravity and the heats, the light module could be separated from the surface of the heat sink or of the back plate of luminaire, shown in the Figure below. It will cause the damage of the LED and the IC. The photo below shows the failure phenomenon Figure 17 Failure mode of thermal issue. Figure 18 Failure mode picture of thermal issue MCPCB with Thermal glue case: Some of our module is designed with MCPCB. We did is use the MCPCB module to fix in the Aluminum reflector. We use two different contact media (no thermal glue and with the thermal glue), and we use three kinds of the fixture (1. screw 2. without the screw 3. Hot melting adhesives). The testing result is shown below: Screw No Screw Melting adhesive No Thermal glue With Thermal Dissipated glue 90.2 N/A 131 (Cannot fix) Table 6. Thermal testing data with MCPCB with glue No obvious effect with MCPCB adding the screw. But never use the Melting adhesive as the fixture since that will become the gravity to induce the bad thermal performance. 20

21 You can see the thermal contact did influence the product performance a lot. So the key of design-in of DDR LED module is the thermal contact. The contact area of the back side of DDR LED module with the back plate of luminaire need to be 100%. Because we use the back plate as the thermal media, we need to make the full contact of the DDR LED module and the back plate. There s many kind of the heat sink shown in the figure below. Some center is full of aluminum (2 nd from left in the top column and 1 st and 2 nd from the left in the bottom column) and the rest is the empty in the center of the heat sink. Remember to select the heat sink with the solid center of the heat sink. Figure 19 various heat sink Or your can select the heat sink just like the right heat sink shown below which has one aluminum plate in the top of the aluminum extrution. Figure 20 heat sink with higher contact area Otherwise the area which didn t contact to the plate 21

22 Safety Safety regulation summary There are many different safety regulation in the worldwide. Not like the energy star and the ERP Directive, the safety regulation is mainly for confirming the safety while you use the luminaire. The structure of safety rule in EU and US is shown below. Figure 21 Structure of safety regulation of US and EU It means that you can not only pass the safety regulation for LED light source and Module but also the safety regulation for luminaire. It s not like the SELV structure we used in the IT industry which always with the adapter. The luminaire needs to pass the safety regulation The table below shows the details regulation for the EU and US and Japan and China. US EU JP CN TW Luminaire US 1598 US 924 / 1574 LVD Direc. ( EN 60598) EMC Direc. PSE GB24819 CNS14335 Module US 8750 EN PSE ECG US 8750 EN PSE GB19510 Light source US 8750 EN Table 7 Safety regulation summary 22

23 Europe (CE) Safety segments of luminaire: Class I luminaire: (With Grounding protection) Luminaire in which protection against electric shock does not rely on basic insulation only, but which includes an additional safety precaution in such a way that means are provided for the connection of accessible conductive parts to the protective (earthing) conductor in the fixed wiring of the installation in such a way that accessible conductive parts cannot become live in the event of a failure of the basic insulation Class II luminaire: (Without Grounding protection) Luminaire in which protection against electric shock does not rely on basic insulation only, but in which additional safety precautions such as double insulation or reinforced insulation are provided, there being no provision for protective earthing or reliance upon installation conditions Class III luminaire: (SELV) luminaire in which protection against electric shock relies on supply at safety extra-low voltage (SELV) and in which voltages higher than those of SELV are not generated. Currently, American Bright s standard product is design for the Class I luminaire. If you have another requirement for the Class II luminaire please let us know then we can customized for you. Warning: All the standard model of opto is designed for Class I luminaire, please add the grounding parts in the luminaire. If there s any problem happened without adding the grounding protection, American Bright opto won t be in charge of any safety related problem. 23

24 LVD / EMC Directive To pass the LVD Directive and EMC Directive is to pass the following regulation: Luminaire: LVD Directive (Based on different luminaire) EN EN EMC Directive EN55015 EN EN EN EN EN EN EN EN EN

25 North America (UL) To pass the LVD Directive and EMC Directive is to pass the following regulation: Luminaire: LVD Directive (Based on different luminaire) UL1598 UL153 UL1574 UL1838 EMC Directive US FCC PART15 Class B ANSI C Module: US

26 Safety recommendations DDR LED module is operated under the high voltage, Please be careful of the high voltage (90-120V AC / V AC ) running of such module, it will cause some vital danger. Please do not touch any place of the circuit board, when the DDR LED module is running. Please use the minimum electrical wire with AWG 24 to fulfill the safety requirement. For some serial connection case, please use the wire > AWG20 as the internal connection wire. Please do not apply any modification when Direct DDR LED module is running. Please do not cut the wire and let people touch the exposed copper wire. The DDR LED module passed the related safety test (Hi-POT/ surge etc), but it won t guarantee the safety of the lighting fixture. The safety of lighting fixture need to be tested individually. Current standard model of American Bright optoelectronics cannot pass the reinforcement insulation, the luminaire need to have the grounding protection. If your luminaire need the reinforce insulation, please contact us then we ll customize for you. 26

27 Installation instructions Installation: 1. Removed the protection paper in the back side of DDR LED module 2. Fix the DDR LED module 3. Fix the DDR LED module with the screw driver 4. Select the proper wire If these DDR module uses the connector, please do follow the instruction of the Connector which is describe below WAGO BJB Photo Conductor size Solid: mm 2 Fine stranded: mm 2 Solid: mm 2 Conductor size (AWG) Table 7 connector spec summary 5. Setup the grounding wire 6. Burn-in 7. Shipment Handling & usage If there s any damage caused by the items listed below, American Bright will not guarantee to exchange or return the damaged products. Assemble under the condition of moisture (RH>60%), oxidizing gas in the air (Cl,H 2S,NH 3,SO 2,NO X,etc) Assemble such LED engine into the lighting fixture without the ESD protection. The static electricity (HBM>2KV) could damage the Direct DRive LED module with an integrated circuit. Please prepare the related equipment to prevent the damage in the handling. Assemble into the finished product with ESD protection. 27

28 Expose the Direct DRive LED module under UV ray and environment full of Sulfur. Touch the silicone resin area with sharp object Contact the silicon area of LED and leave the finger print on silicone area of LED(it will impact the life performance of LED module. Storage Condition: Please store in covered containers as it is dust sensitive. Do not store or place the Direct DRive LED module under the environment shown below: 1. Heavy weight without protection.. 2. High temperatures (>80 o C). 3. High humidity (RH>60%). 4. Direct sunlight

29 Your sincere partner American Bright Optoelectronics 30