Application Note WICOP2 New Generation of WICOP 介绍 为了保证WICOP2系列产品的光效和稳定的性能，本应用手册针对WI COP2系列产品的组装与处理进行了建议， 梗概 本手册针对如下产品进行了组装与处理的建议 Z8 YXX-WA-CN XX Designates packaging size ( 19 for 1.81x1.81mm size, 15 for 1.41x1.41mm size) A White Color (0 for Cool, N for Neutral, W for Warm) N Designates CRI (7 for CRI min.70, 8 for CRI min. 80, 9 for CRI min. 90) WICOP Application Note © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 1 www.seoulsemicon.com Application Note WICOP2 - High-power LED Table of Contents Index • Introduction 1 • Scope 1 • Component 3 • Printed Circuit Board Design Guideline 6 • Thermal Measurement Guideline 8 • Assembly Process Guideline 10 • Array Design Guideline 13 • WICOP 2 Characteristic Graph 15 • Company Information 17 WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 2 www.seoulsemicon.com Application Note WICOP2 - High-power LED 1. 内容 1.1 描述 Anode 0,3 0,56 Cathode 0,56 WICOP2是基于CSP技术的产品 。他们具有体积小，功率高，等特点。WICOP2 也是使用高亮度的InGaN芯片，无ESD防护二极管的设置。 WICOP2的底部包含两个大小相同的正负电极(见图一) 。 1,41 BOTTOM VIEW Z8Y19 SIDE VIEW Cathode BOTTOM VIEW Z8Y15 SIDE VIEW Figure 1. WICOP 2 Z8Y19, Z8Y15 Solder Pad Dimensions. WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 3 www.seoulsemicon.com Application Note WICOP2 - High-power LED 1.2 光学中心 Z8Y19 的发光中心是距离LED边缘0.955mm的位置。Z8Y15的发光中心是距离LE D边缘0.705mm的位置(见图二) 0.905mm 0.705mm Z8Y15 Z8Y19 Figure 2. Optical Centers of the WICOP 2 Series 1.3 手工作业注意事项 不适合的处理方式会造成LED芯片的损伤，会影响LED的亮度和可靠性。为了 尽量减小在处理过程中对LED的损伤，WICOP2的拾取应该是用自动SMT设备或 者真空镊子来吸取。当处理完LED后请不要用手或金属镊子触碰，也要避免压 迫LED表面。(见图三a) 贴装LED后请不要再将LED翻转，不要将多层PCB堆在一起。因为LED的表面为 软质的硅胶.WICOP2的表面的污损会造成硅胶的损伤，此外对LED的的压迫也 会造成硅胶层或者内部芯片的损伤。(见图三b) WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 4 www.seoulsemicon.com Application Note WICOP2 - High-power LED Figure 3 (a). Incorrect handling of WICOP 2 LEDs Figure 3 (b). Incorrect handling of WICOP 2 LEDs 1.4 清理 WICOP2 LED应该避免直接接触灰尘和污物。灰尘和污物会使LED光通量降低。 如果需要清理LED表面建议使用压缩气体在距离6 ”的位置来清理，压缩气体 枪喷嘴最好大小为20 psi . 1.5 电极隔离 WICOP2底部有2个电极相距0.3mm。为了避免电流冲击或者损伤WICOP2，每 个电极的设计都需要依照相关标准进行。 1.6 结构文件 WICOP2的结构文件（2D,3D文件）可以申请 WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 5 www.seoulsemicon.com Application Note WICOP2 - High-power LED 2. 印制电路设计指导 WICOP2可以设计焊接在附铜的基板上（MCPCB）。为了使设计更加优化，建 议PCB尽量减少LED到散热器上的热阻。 2.1 焊管脚 0,56 0,34 0,98 0,34 1,41 1,41 0,98 ST 0,3 0,56 Anode 0,3 0,56 Cathode 0,56 为了使LED更好的挥特性，WICOP2需要焊接在具有相匹配焊垫的PCB上。具体 焊垫大小尺寸请参见图4. WICOP2的电极也是PCB和LED间的散热垫。为了使热量更好的从LED散到PCB， 建议最好将附铜层扩大到距离中心4mm的面积. 0,91 0,91 0,31 0,31 0,3 Cathode Figure 4. Recommended PCB Footprint for. WICOP 2 All dimensions in mm. WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 6 www.seoulsemicon.com Application Note WICOP2 - High-power LED 2.2 Silk Color The performance of an WICOP 2 can be impacted by the color of the silk screen used on the PCB. There can be an efficacy loss due to optical absorption by a black color. It is recommended to either use yellow color for the silk screen or not to use any markings around a WICOP 2 as shown in Figure 5. X O Figure 5. WICOP 2 Silk color Recommendations 2.3 PCB Artwork The PCB design for the WICOP 2 Series can impact the thermal performance of the end product. Figure 6 shows two different artwork designs for the same circuit. The red pattern indicate the copper traces. Wide copper traces should be used to allow a robust thermal path for the anode and cathode pads. X O Figure 6. PCB layout recommendations WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 7 www.seoulsemicon.com Application Note WICOP2 - High-power LED 2.4 PSR (Photo Solder Resist) Seoul Semiconductor recommends a PCB with high optical reflectivity PSR for the WICOP 2. Because of the radiation pattern of the LED, the reflectivity of the PCB (PSR) can impact the optical efficacy. It is recommended that the reflectivity of the PSR is greater than 80%. 2.5 最小距离 Seoul Semiconductor recommends a minimum edge to edge spacing between adjacent WICOP 2 of 0.2mm. The spacing of multiple WICOP 2 can impact the performance of a LED system in two ways. 1) Heat dissipation: Close spacing of the LEDs may limit the PCB’s to ability to dissipate the heat from the LEDs. 2) Optical Absorption: Close spacing of the LEDs could impact the light output due to optical absorption or cross talk between adjacent LEDs. More information on this can be found in the array guidelines(Section 5). 3. 热测量指导 本部分介绍了如何测试和确定LED结温，来验证不同应用是否超出了LED规格 书所规定的结温.LED的P/N结到焊盘的热阻可以在规格书上找到。对WICOP2来 说，电极也是散热垫。结合这些事实LED的结温可以用如下公式来计算： Tj = TS + RƟjs • Pelectrical 在这个公式中Pelectrical是LED自身的消耗功率，Ts测试点是LED底部的任意一 个电极。其中两个电极都是与PCB的附铜层相连 的。 Due to the size of the WICOP 2, it may be difficult to measure the thermal pad temperature directly. Therefore, a practical way to determine the WICOP 2 junction temperature is by measuring the temperature Ts of a predetermined sensor pad on the PCB close to the WICOP 2 with a thermocouple as shown in Figure 7. To ensure accurate readings, the thermocouple must make direct contact with the copper of the PCB onto which the WICOP 2 electrode pads are soldered, i.e. any solder mask or other masking layer must be first removed before mounting the thermocouple onto the PCB. WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 8 www.seoulsemicon.com Application Note WICOP2 - High-power LED Figure 7. Recommended Ts configuration 下面几点建议可以帮助您确定大概Ts测温点的位置，以便在LED阵列应用中避 免超过最大的结温： a. 如果在PCB上没有设计对称的附铜层，最好把Ts测温点放置在电极（正极或 负极）旁边，在这个电极上热扩散到PCB是最受阻碍的。即该电极焊接在附 铜最少的地方。 b. 如果LED使用不同电流驱动，一般都是测量LED最大功率状态时。 在1.5mm厚的Al-MCPCB（2oz 附铜 或者80~100µm 厚，导热率5W/m·K ）时， LED从P/N结到Ts测温点的热阻是3K/W。 如果LED 基板设计有很多LED数量时，还需要额外测试这些LED中心部位的温度 才是最准确的。 WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 9 www.seoulsemicon.com Application Note WICOP2 - High-power LED 4. 矩阵设计指导 4.1 印制板设计 为了设计适合的WICOP2印制电路板和管脚PCB(见图4)，要求板材的厚度为100 ~120μm。小巧的线路布局是为了避免焊接部分开焊和避免锡膏偶然的造成正 负极短接，隐隐正负极之间仅有300μm的距离(见图 2.1 WICOP 2 Solder Footprint) 4.2 拾取和安放 WICOP2 LED 需要使用自动贴片机来进行，吸嘴形式见图8 鉴于拾取和贴装的实验，首尔半导体建议依照下列要求进行： 1. 吸嘴的顶部应正对在LED表面平坦的位置。 2. 吸嘴顶部应该进行清理不要有任何污染。 3. 在最初的生产过程中，需要在显微镜下检查WICOP2的顶部，确认发光部 位没有收到任何损伤，尤其是没有被吸嘴等贴装过程损害。 Items Outer diameter X Remark 1.2~1.6 mm Inner diameter Y 0.5~0.65 mm Materials Rubber or Ceramic Figure 8. Pick and place nozzle design and dimensions WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 10 www.seoulsemicon.com Application Note WICOP2 - High-power LED 4.3 焊锡膏 首尔半导体建议使用免清洗锡膏，成分组成： SnAgCu (tin/silver/copper) 4.4 印制电路 建议印制板的厚度0.1~0.12mm。为了保证印制板的品质，建议参考如下要求： 1. 印制板需要保持平滑，没有毛刺，没有污染。 2. 印制板需要保持一致的厚度。 3. 印制板和PCB的位置公差应该足够小，保证锡膏在印刷后不会从管脚处流 出。 Items Squeeze conditions Stencil mask Remark Pressure 2.5-5.0Kgf/㎠ Distance 2-4mm Velocity 20-100mm/sec Thickness 0.1~0.12mm Vacuum 0.5±0.05mpa Solder paste area X, Y Tolerance 90-100% ±150 um Table 1. Stencil mask and soldering information. WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 11 www.seoulsemicon.com Application Note WICOP2 - High-power LED 4.5 回流焊工艺 WICOP2可应用于标准回流焊焊接工艺，下图为温度曲线的参考具体参数参见 Figure 9 and Table 2 Figure 9. Solder reflow profile. Table 2. Recommended reflow conditions Profile Feature Pb-Free Assembly Average ramp-up rate (Tsmax to Tp) 3° C/second max. Preheat - Temperature Min (Tsmin) - Temperature Max (Tsmax) - Time (Tsmin to Tsmax) (ts) 150 °C 180 °C 80-120 seconds Time maintained above: - Temperature (TL) - Time (tL) 217~220°C 80-100 seconds Peak Temperature (Tp) 250~255℃ Time within 5°C of actual Peak Temperature (tp)2 20-40 seconds Ramp-down Rate 6 °C/second max. Time 25°C to Peak Temperature 8 minutes max. Atmosphere Nitrogen (O2<1000ppm) Table parameters established based on SMIC: M705-GRN360-K2-V (solder paste) 注意事项 (1) 不要进行重复焊接。如果必须要重复焊接的话，需要仔细的检查和维修。 (2) 在加热时不要对LED施加任何压力。 (3) 回流焊接后不要弯折PCB板。 (4) 回流焊后不要对PCB进行任何清洗。 WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 12 www.seoulsemicon.com Application Note WICOP2 - High-power LED 5. WICOP 2 阵列设计指导 首尔半导体建议LED和LED的最小间距为0.2mm。太近距离会导致热量过于集中 从而影响LED。 5.1 效率与距离的关系 LED的出光效率与LED的位置有关。LED位置太近会导致光通的损失。下面的数 据说明了距离为1mm是效率的变化情况(Figure 11). 测试信息，LED驱动到2W/Pkg。 PCB使用1.5mm厚度的 Al-MCPCB, 1.5mm X 1.5mm 大小的板材， 2oz 的附铜。 Figure 10. Simulation and device configurations Figure 11. Simulation and Device test results. WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 13 www.seoulsemicon.com Application Note WICOP2 - High-power LED 测试结果表明光会被临近的LED所吸收具体数据见Figure 8。这部分损失并不是 热损。具体测试条件是25°C脉冲驱动LED到2W的情况测试的。模拟和实际测试 结果稍有不同，单是光效的变化趋势是一致的。这些细微的差距可以看做是LE D在焊接时的损失。 5.2 结温与距离的关系 将WICOP2 LED设计的过于紧凑会导致热的相互影响。LED数量和PCB的配置可 以擦考结温的热模拟模型。 Figures 12 和 13 是不同距离时的热模拟结果 Figure 12. Thermal simulation configurations. Figure 13. Thermal simulation results depend on WICOP 2s’ distance. WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 14 www.seoulsemicon.com Application Note WICOP2 - High-power LED 6. WICOP 2 Characteristics Graph (Z8Y19) ◆ Junction Temperature vs. Relative Luminous Output , Current = 700mA 120 Response: Flux vs Temperature Temperature Relative Flux[%] 25 111.8 50 106.0 60 70 102.3 85 100 40 100 96.4 125 91.1 145 87.1 Relative luminous flux [%] 100 80 20 0 25 50 75 100 125 o Junction Temperature [ C] ◆ Junction Temperature vs. Relative Forward Voltage , Current = 700mA 0.25 Response: VF vs Temperature 0.20 0.15 0.10 VF 0.05 Temperature Relative Voltage 25 0.14 50 0.06 70 0.02 0.00 85 0 -0.05 100 -0.03 -0.10 125 -0.06 -0.15 145 -0.09 -0.20 25 50 75 100 125 o Junction Temperature [ C] WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 15 www.seoulsemicon.com Application Note WICOP2 - High-power LED ◆ Forward Current vs. Forward Voltage , TJ = 85℃ 2.2 Response: Voltage vs Current 2.0 Voltage Current [mA] 2.7142 100 2.8764 300 3.0069 500 1.0 3.1204 700 0.8 3.2643 1000 0.6 3.3954 1400 0.4 3.4413 1600 0.2 3.4804 1800 0.0 3.5122 2000 Forward Current [A] 1.8 1.6 1.4 1.2 2.6 2.8 3.0 3.2 3.4 3.6 Forward Voltage [V] ◆ Forward Current vs. Relative Luminous Flux , TJ = 85℃ 240 Response: Flux vs Current Relative Luminous Flux [%] 220 200 Current [mA] Relative Flux[%] 180 100 16.2 160 300 46.9 140 500 74.1 120 700 100 100 1000 136.1 80 1400 179.4 60 1600 198.9 40 1800 216.3 20 2000 233.7 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Forward Current [mA] WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 16 www.seoulsemicon.com Application Note WICOP2 - High-power LED Company Information Published by Seoul Semiconductor © 2013 All Rights Reserved. Company Information Seoul Semiconductor (www.SeoulSemicon.com) manufacturers and packages a wide selection of light emitting diodes (LEDs) for the automotive, general illumination/lighting, Home appliance, signage and back lighting markets. The company is the world’s fifth largest LED supplier, holding more than 10,000 patents globally, while offering a wide range of LED technology and production capacity in areas such as “nPola”, "Acrich", the world’s first commercially produced AC LED, and "Acrich MJT Multi-Junction Technology" a proprietary family of high-voltage LEDs. The company’s broad product portfolio includes a wide array of package and device choices such as Acrich and Acirch2, high-brightness LEDs, mid-power LEDs, side-view LEDs, and through-hole type LEDs as well as custom modules, displays, and sensors. Legal Disclaimer Information in this document is provided in connection with Seoul Semiconductor products. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, Seoul Semiconductor hereby disclaims any and all warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights of any third party. The appearance and specifications of the product can be changed to improve the quality and/or performance without notice. WICOP Application Brief © 2013 All Rights Reserved. Rev1.1, Sep 25, 2015 17 www.seoulsemicon.com