刚挠印制板在电子产品中的应用

刚挠电路不仅仅是另外一种常规的挠性电路。将挠性化和刚性化的基片结合在一起层压为一个单一的组件会形成独特的挑战和优点。刚挠电路可以让设计师们替换具有连接器、导线和带状电缆的多层PCB组件互连，将它们作为一个单一的组件来提供更高的性能和可靠性。     

Properties and Microstructures of Low-Temperature-Processable Ultralow-Dielectric Porous Polyimide Films

Coating of ultralow-dielectric (ultralow-k) polymers on high-speed and high-frequency circuitries can increase signal propagation speed and reduce crosstalk. High-temperature foamed films have ultralow-k properties, but are ineffective in noise reduction because of the presence of dense skins. Vapor-induced phase separation was used to fabricate porous polyimide films in this investigation. Scanning electron microscopy revealed that the films are homogeneous without skin layers. The pore size can be controlled from less than a micron to several microns. Electrical characterization revealed that the relative dielectric constant is reduced to as low as 1.7 and is stable between 8.2 GHz and 18 GHz. Usage of this new ultralow-k material as a substrate can help to improve circuit speed by more than 40% compared to the dense Kapton substrate, making this material well suited for use in wide-band and high-frequency applications.     

满足无铅化应用需要的热风整平技术

在PCB组件中，现在仍有超过60％的组件大量采用热风整平（HAL）工艺技术，但人们大多数的研究工作还是针对ENIG、OSP、浸银和浸锡等。无铅化热风整平PCB组件往往会被忽视。那么热风整平技术能否胜任无铅化应用的要求呢？丈章试图予以简单介绍。     

Constitutive Relations of Indium in Extreme-Temperature Electronic Packaging Based on Anand Model

The advantage of pure indium (In) for cryogenic joining has been acknowledged for many years. However, full characterization of its low-temperature rate-dependent behavior is lacking. In this work, a rate- and temperature-dependent constitutive model, the Anand model, was successfully applied to represent the inelastic deformation behavior of indium at low temperatures down to −150°C. Test data used for fitting the material parameters in the Anand model was acquired in a series of compression constant-load tests conducted under isothermal conditions at different temperatures ranging from −150°C to 0°C.     

Black box modelling of the Op-Amp including switching power supply on effect

In general, models at the device and circuit levels are very important in system design. Building compact models at the circuit level is complicated, needs a lot of physical information about the circuit and moreover it has a long simulation time. We present in this paper an alternative modeling methodology, black box modeling. In this technique, we need only the output behavior of the circuit. We get this behavior either from measurements or simulations from previously built compact models. We apply this technique to the operational amplifier as a case study. We use the Op-Amp, BSIM3v3-based compact transistor model, to obtain the performance of the circuit. An excellent agreement is obtained between the output voltage from the black box model of the Op-Amp (for both of the effect of the switching power supply on and the steady state behavior) and the corresponding output from the model used to build it.     

关注无铅化可制造性设计

对于OEM制造厂商来说认识含铅和无铅化元器件之间所存在的封装和焊盘的不同处是非常关键的；这种差异可能会导致成本昂贵的制造缺陷。含铅的可制造性设计（Design for Manufacturing，简称DfM）包含确认在PCB设计布线、制造、装配和元器件管理方面己开展的行之有效的工作。然而，无铅化的可制造性设计在那四大类的每一个方面的工作都面临着非常大的变化。所以要确认每一个细节使之能够正确地进行操作。     

Controlling the microstructure from the gold-tin reaction

The microstructures from the reaction between Au and Sn under different conditions were studied. A Sn/Au/Ni sandwich structure (2.5/3.752 μm) was deposited over the Si wafer. The overall composition of the Au and Sn layers corresponded to the Au20Sn binary eutectic (wt.%). When the reaction condition was 290°C for 2 min, the microstructure produced was a typical two-phase (Au₅Sn and AuSn) eutectic microstructure over Ni. In contrast, when the reaction condition was 240°C for 2 min, a AuSn/Au₅Sn/Ni layered microstructure was produced. In both microstructures, a small amount of Ni was dissolved in Au₅Sn and AuSn. When the AuSn/Au₅Sn/Ni layered structure was subjected to aging at 240°C, the AuSn layer gradually exchanged its position with the Au₅Sn layer and eventually formed an Au₅Sn/AuSn/Ni three-layer structure in less than 9 h. The driving force for Au₅Sn and AuSn to exchange their positions is for the AuSn phase to seek more Ni. The dominant diffusing species for the AuSn and Au₅Sn has also been identified to be Au and Sn, respectively.     

阵列式微型透镜封装多芯片COB LED的光学仿真设计及应用

为了提高COB LED的取光率,以1919 COB LED为研究对象,建立阵列式圆锥透镜、半椭球透镜、四棱锥透镜和半圆球透镜封装LED模型,并利用光学仿真软件进行研究。仿真实验结果表明:在优化条件下,高0.5 mm、直径0.9 mm的阵列圆锥透镜封装LED的光通量由平面封装的67 lm提高至84.3 lm,即取光率提高25.8%。制作了RGB芯片的多芯片LED样品,并用直径1 mm的阵列半圆球透镜进行封装,其取光率提高18.8%。     

超高效液相色谱-串联质谱法同时测定聚合物食品包装材料中8种添加剂

建立了同时测定聚合物食品包装材料中8种常用添加剂Irgafos 168、Irganox 1010、Irganox 1076、丁基羟基茴香醚（BHA）、没食子酸丙酯（PG）、没食子酸十二酯（DG）、叔丁基对苯二酚（TBHQ）和苯三唑甲酚（UV-326）的超高效液相色谱-串联质谱方法。试样以二氯甲烷为溶剂进行超声提取;采用Waters BEH-C18柱（50 mm×2.1 mm,1.7 μm）分离,以0.05%甲酸水溶液和甲醇为流动相进行梯度洗脱;采用电喷雾离子源正、负离子切换模式和多反应监测模式进行检测。8种添加剂在相应的质量浓度范围内定量离子的峰面积与质量浓度均呈良好线性关系（相关系数R²均大于0.993）,回收率为63.9%~127.0%,相对标准偏差（RSD,n=6）≤15.8%,检出限（S/N=3）为0.13~5.50 μg/L,定量限（S/N=10）为0.45~17.50 μg/L。该方法简便快捷、灵敏度高,适合食品包装材料中常用添加剂的分析测定。     

BGA器件及其常见的形式

BGA器件不仅能够满足现在已有的其它组件所不能够提供的高性能、大量I/O数量的应用要求,也给如今的有引脚元器件提供了一种可靠的可替换方案。对于在组件体的底部位置安置有大量焊球阵列的BGA器件来说有四种主要的类型。表面阵列配置的组装技术将会成为电子组装业最主要的发展潮流。