塑料生物芯片的激光焊接封装系统研究

介绍了采用半导体激光器在塑料生物芯片焊接封装系统的应用,论述了塑料生物芯片焊接封装原理和工艺,提出了基于808nm半导体激光器的塑料焊接封装系统的设计方法,分析了焊接封装的参数选择,实现了部分塑料之间的成功焊接.     

塑料生物芯片的激光焊接封装系统研究

介绍了采用半导体激光器在塑料生物芯片焊接封装系统的应用，论述了塑料生物芯片焊接封装原理和工艺，提出了基于808nm半导体激光器的塑料焊接封装系统的设计方法，分析了焊接封装的参数选择，实现了部分塑料之间的成功焊接。     

激光技术与应用

激光焊接微塑料元件；电子元件生产中的激光再加工；用激光加工使微流体元件快速成型；激光精细加工光学生物芯片；采用准分子激光器制作光电印刷线路板中的微反射镜。     

高功率二极管激光器Au80Sn20焊料焊接实验研究

半导体激光器封装工艺过程对于激光器的输出特性、寿命等性能有重要影响,其中焊料的选择和焊接工艺是最关键的因素。本文采用磁控溅射的方法,在 WCu 热沉上制备了Au80Sn20合金焊料,取代了传统的In焊料,并对焊接工艺进行了改进。国外沉积的和我们制备的Au80Sn20合金焊料焊接DL芯片后的性能参数很接近。充分说明双靶分层溅射镀膜可以实现二极管激光器的封装要求,从而为优化半导体激光器制备工艺和提高半导体激光器的性能奠定基础。     

用于CATV的DFB激光器同轴封装激光焊接技术研究

激光焊接技术广泛应用于光电子封装领域,它能形成很强的结合力,显示出无可比拟的优越性.但激光脉冲形状设置仍存在一定缺陷.研究了用于CATV的DFB激光器同轴封装激光焊接技术,利用Nd:YAG激光焊接系统,在两种不同的激光脉冲形式下,对DFB激光器和光纤进行焊接,分析了焊点宽度、深度与激光脉冲的关系.通过推力实验,测得DFB激光器输出先功率的变化大小,验证焊点质量,得出实际生产中脉宽为5 ms和2 ms、电压为310 V和360 V的激光脉冲,从而提高了焊接质量和工艺水平.     

聚碳酸酯激光透射焊接工艺及性能研究

在激光塑料透射焊接理论的基础上,采用半导体激光器焊接聚碳酸酯(PC)塑料薄板,研究了激光焊接热塑性塑料的可行性。设计并确定了激光透射焊接的实验方案,包括激光器和焊接材料的选择。通过微观金相实验分析了焊接因素对焊接质量的影响。通过正交实验法研究了激光功率、焊接速度、炭黑含量对焊接质量的影响。结果表明对于聚碳酸酯材料而言,激光功率是影响焊接质量的首要因素,其次是焊接速度,最后是炭黑含量。     

激光塑料焊接技术的研究

首先论述了激光塑料焊接的原理;其次阐述了国内外激光塑料焊接的工艺发展概况,包括焊接用激光器的各种重要参数、焊接材料、激光焊接的吸收剂,并简要介绍了激光焊接领域内的最新研究成果;最后介绍激光塑料焊接在工业中的应用及其发展趋势.     

半导体激光器封装中热应力和变形的分析

为了解决半导体激光器封装的热应力和变形问题,利用有限元软件ANSYS对SnPb、In、AuSn三种焊料焊接激光器管芯的情况分别进行了模拟,得到了相应的热应力大小和变形情况,分析了焊料和热沉对激光器热应力和变形的影响.对比了这几种不同封装方法的激光器发光区图像的弯曲程度,验证了模拟结果.由模拟和实验结果可见,采用In焊料是减小激光器热应力和变形的最佳选择.另外,适当增加热沉厚度,选择热匹配的材料,焊接时进行预热,可减小激光器的热应力和变形.通过模拟和实验分析,提出了减小热应力和变形的方法,为优化激光器的封装设计提供了参考依据.     

全金属化耦合封装的大功率半导体激光器模块

大功率半导体激光器模块对耦合封装工艺要求较高,耦合封装工艺直接影响模块的可靠性。采用金属化楔形微透镜光纤与大功率半导体激光器对准耦合,耦合效率达到87%;采用激光焊接定位的方式对大功率半导体激光器与楔形微透镜光纤进行耦合固定,实现了大功率半导体激光器模块的全金属化封装。通过环境考核试验证明,模块储存温度达到-60～120℃,能够满足许多特殊环境对半导体激光器模块的要求。     

Nd:YAG薄片激光增益介质封装技术

为了保证Nd:YAG薄片激光器的高功率、高光束质量,需解决薄片增益介质封装后的均匀散热、低波前畸变等关键问题。分析了封装过程中薄片增益介质的热应力,模拟了连接界面无缺陷条件下薄片增益介质的热分布,对封装工艺技术进行改进。优化的封装技术将薄片激光增益介质与微通道冷却器连接在一起,采用超声扫描显微镜、激光干涉仪对薄片激光器的焊接界面与增益介质表面面形进行测试。结果表明:该封装技术实现了直径80 mm的大口径YAG薄片与冷却器焊料层均匀、无空洞的界面连接,同时减小了焊接后薄片的波前畸变,60 mm口径内面形畸变PV值小于1 m,均方根RMS值小于0.15 m。该技术封装的单模块Nd:YAG薄片激光器输出功率达到2.3 kW。     

高聚物生物芯片材料激光加工性能分析

用准分子激光对高聚物材料进行微加工制作,可以获得比较理想的高聚物基生物芯片。根据对制作生物芯片材料的性能要求,比较了聚甲基丙烯酸甲酯(PMMA)和聚碳酸酯(PC)对不同波长激光的光波透过率,测量了高聚物材料经准分子激光加工后的微结构,并得出准分子激光对不同材料的刻蚀速率与入射激光能量密度之间的关系。结果表明,PMMA和PC都能够完全吸收KrF准分子激光能量,可以用准分子激光在表面进行微加工制作生物芯片;用PMMA制作出的生物芯片,在使用时对检测结果的质量影响比PC小;对于相同的入射激光能量密度,准分子激光对PMMA的刻蚀率比PC高;由于与准分子激光之间的反应机理不同,PMMA更容易被加工,但是加工后的微结构质量较PC差。     

准分子激光加工PMMA生物芯片片基的实验研究

用准分子激光对高聚物材料进行微加工制作,可以得到比较理想的高聚物基生物芯片。采用248nm的KrF准分子激光器对PMMA(聚甲基丙烯酸甲酯)进行微细加工,探讨了准分子激光与PMMA相互作用的机理。进行了表面微通道制作和打孔实验,研究激光加工的工艺参数及加工质量的变化规律。结果表明,准分子激光蚀刻完全适合生物芯片的制作,而且加工过程简单,是一种行之有效的制作方法。     

Microfabrication, surface modification, and laser guidance techniques to create a neuron biochip

In this report we illustrate our application of soft lithography-based microfabrication, surface modification, and our unique laser cell-patterning system toward the creation of neuron biochips. We deposited individual forebrain neurons from Day 7 embryonic chicks into two rows of eight in a silicon microstructure aligned over a microelectrode array （MEA）. The polydimethylsiloxane （PDMS） membrane with microstructures to confine cells and guide network connectivity was aligned to the electrodes of a MEA. Both the MEA and the PDMS membrane were treated with O2 plasma, Poly-L-Lysine, and Laminin to aid in cell attachment and survival. The primary advantage of our process is that it is quicker and simpler than previous cell-placement methods and may make highly defined neuronal network biochips more practical.     

激光键合的有限元仿真及工艺参数优化

在硅/玻璃激光键合中,温度场的分布是影响晶片能否键合的关键因素.本文利用有限元法建立了移动高斯热源作用下硅/玻璃激光键合的三维温度场数值分析模型.运用该模型计算了不同的工艺参数条件下硅/玻璃的温度场分布,并由此得出键合线宽.然后通过漏选试验确定影响激光键合的主要工艺参数有激光功率、激光扫描速度及键合初始温度.最后通过对仿真结果进行回归分析,得到激光键合工艺的最优参数,为进一步研究激光键合工艺提供了理论依据.     

应用于微系统封装的激光局部加热键合技术

阐述了利用激光与物质相互作用的热效应实现微系统器件的局部加热键合原理 ,提出了激光键合塑料芯片和激光辅助加热阳极键合的思想 ,建立了半导体激光键合实验装置 ,并实现了聚甲基丙烯酸甲酯 (PMMA)之间的键合     

Test Planning in Digital Microfluidic Biochips Using Efficient Eulerization Techniques

Digital microfluidic technology is now being extensively used for implementing a lab-on-a-chip. Microfluidic biochips are often used for safety-critical applications, clinical diagnosis, and for genome analysis. Thus, devising effective and faster testing methodologies to warrant correct operations of these devices after manufacture and during bioassay operations, is very much needed. In this paper, we propose an Euler tour based technique to obtain the route plan of a test droplet for the purpose of structural testing of biochips. The method is applicable to various digital microfluidic biochip architectures, e.g., fully reconfigurable arrays, application specific biochips, pin-constrained irregular geometry biochips, and to defect-tolerant biochips. We show that in general, the optimal Eulerization and subsequent determination of an Euler tour in the graph model of a biochip can be abstracted in terms of the classical Chinese postman problem. The Euler tour can be identified by running the classical Hierholzer’s algorithm, which relies on a simple cycle decomposition and splicing method. This improved Eulerization technique leads to an efficient test plan for the chip. This can also be used in phase-based test planning that yields savings in testing time. The method provides a unified approach towards structural testing and can be easily adopted to design a droplet routing procedure for functional testing of digital microfluidic biochips.     

引脚约束的数字微流控生物芯片在线并行测试

随着数字微流控生物芯片在生化领域中的广泛应用,对芯片可靠性和制造成本的要求也越来越高,在线测试对于确保微流控生物芯片正常工作异常重要。该文针对引脚约束的数字微流控生物芯片,提出一种基于改进最大最小蚁群算法的在线并行测试方案,在满足各种约束条件的情况下,采用伪随机比例原则,建立禁忌判断策略,自适应地改变信息素的残留系数,实现引脚约束数字微流控生物芯片的在线并行测试。实验结果表明,该方法可以同时用于离线和在线测试,相对于单液滴离线和在线测试,可有效减少芯片的测试时间,提高了测试工作效率。     

Offline Error Detection in MEDA-Based Digital Microfluidic Biochips Using Oscillation-Based Testing Methodology

Digital microfluidics is an emerging class of lab-on-a-chip system. Reliability is a critical performance parameter as these biochips are employed in various safety-critical biomedical applications. With the introduction of highly scalable, reconfigurable and field programmable Micro-Electrode-Dot-Array (MEDA) architecture, the limitation of conventional DMFBs in varying the droplet size/volume in fine grain manner has been resolved. However, the MEDA-based biochips must be adequately tested upon fabrication to guarantee the correctness of bioassays. In this work, an offline testing approach based on Oscillation-Based Testing (OBT) methodology is presented for MEDA-based digital microfluidic biochips. Various simulations were performed for droplet-electrode short fault model involving single and multiple micro-electrodes. Furthermore, the loss of droplet volume due to the presence of defect was analyzed using COMSOL Multiphysics. The simulation results based on PSpice and COMSOL show that the proposed approach is effective for detecting defects in MEDA-based biochips.     

On-Line Test of Pin-Constrained Digital Microfluidic Biochips with Connect-5 Structure

Digital microfluidic biochips (DMFBs) are widely used in the field of biochemistry. Effective off-line and on-line test for the biochips are required to ensure the system reliability. For direct addressing digital microfluidic biochips (DDMFBs), each control pin corresponds to only one electrode, and that can facilitate the testing of such biochips. However, in pin-constrained digital microfluidic biochips (PDMFBs), multiple electrodes may share one control pin, and thus the testing will be more difficult. In this paper, the pin constraint formula for PDMFBs with connect-5 structure is derived. A novel pin assignment scheme is also proposed, which can conduct on-line test that rarely considered by the previous methods. Furthermore, a hybrid method combining the priority strategy and genetic algorithm is introduced for the on-line test of pin-constrained digital microfluidic biochip with connect-5 structure. The simulation results show that the shortest test path acquired by the proposed method is equal to the optimal value of Euler path, which indicates that the method can effectively implement the on-line test of PDMFBs with connect-5 structure.

     

半导体激光器模组的设计

设计了一种半导体激光器模组以满足实际应用的需要.在半导体激光器模组设计中,激光器选择、光学系统设计、激光器电路设计与"邦定"技术是模组设计的关键部分.论述了半导体激光器原理,介绍了半导体激光器模组光学系统与电路设计,阐述了模组设计中"邦定"技术的工艺流程与关键技术.模组中半导体激光器的波长为635nm,驱动电源在3V～ 5V之间,激光功率在2mW左右,光学系统由一个双胶合透镜和一个正透镜组合而成,设计研制的半导体激光器模组满足设计要求.