Ultrafast UV-Curable Adhesives for Optical Pick-Ups

This paper describes novel ultraviolet (UV)-curable adhesives with an ultrafast curing rate which are fully cured within 8 s for optical pick-up (OPU) applications. Two kinds of oligomers (novolac epoxy acrylate and urethane acrylate), additives, and inorganic fillers were prepared for the formulation of the adhesives. In addition, three kinds of photo-initiator [2,2-dimethoxy-2-phenylacetophenone and 2-hydroxy-2-methylpropiophenone for surface curing and (2,4,6-trimethylbenzoyl) diphenyl phosphine oxide (TMDPO) for deep curing] were mixed to increase the curing rate. Photo-differential scanning calorimetry (photo-DSC) analyses showed that the newly formulated UV adhesives had faster curing rate than conventional UV adhesives. The UV adhesives were applied to OPUs for DVD/CD-RW, and five kinds of reliability tests, i.e., thermal shock, low-temperature storage, high-temperature storage, high temperature/high humidity, and nonoperation shock tests, were conducted to evaluate the adhesive reliability. According to the results of reliability tests and thermal stress simulations, the UV adhesives with lower storage modulus (E′) showed better thermal shock reliability due to lower thermal stresses. In addition, OPUs assembled using the UV adhesives passed all reliability tests. Consequently, the UV adhesives were successfully applied to OPUs in OPU production lines, contributing to mass production.     

精细电路连接用紫外光固化各向异性导电胶

为适应高密度超细线路连接的需要,研究了紫外光固化各向异性导电胶。得到了可以用UV(紫外光)有效固化的各向异性导电胶(ACA)。通过对固化过程和应用于氧化铟锡连接实验的分析,研究了各组分在体系中的作用和添加量对导电胶的连接性能和导电性能的影响。结果表明,紫外光固化各向异性导电胶为液晶显示(LCD)和电致发光显示(ELD)技术提供了一种新的连接方式。     

High-Sensitivity Measurement of Thermal Deformation in a Stacked Multichip Package

The thermal deformation of a stacked multichip package, which is a newly developed electronic package, was measured by phase-shifting moireacute interferometry. We developed this method using a wedged glass plate as a phase shifter to obtain displacement fields having a sensitivity of 30nm/line. This method also enabled the quantitative determination of the strain distributions in all observation areas. Thermal loading was applied from room temperature (25degC) to elevated temperatures of 75degC and 100degC where the thermal strains were examined and compared. The results showed that the longitudinal strain epsiv_xx was concentrated at the ends of two silicon chips, and the longitudinal strain epsiv_yy increased between the two silicon chips. The shear strain gamma_xy increased at the end of the lower silicon chip from 0.17% to 0.30% when the temperature increased by 25degC     

3D封装及其最新研究进展

介绍了3D封装的主要形式和分类。将实现3D互连的方法分为引线键合、倒装芯片、硅通孔、薄膜导线等,并对它们的优缺点进行了分析。围绕凸点技术、金属化、芯片减薄及清洁、散热及电路性能、嵌入式工艺、低温互连工艺等,重点阐述了3D互连工艺的最新研究成果。结合行业背景和国内外专家学者的研究,指出3D封装主要面临的是散热和工艺兼容性等问题,提出应尽快形成统一的行业标准和系统的评价检测体系,同时指出对穿透硅通孔(TSV)互连工艺的研究是未来研究工作的重点和热点。     

3D封装中的圆片减薄技术

随着微电子工业迅猛发展,圆片直径越来越大,当150mm、200mm甚至300mm英寸圆片被减薄到150μm以下时,圆片翘曲和边缘损伤问题变得尤为突出。超薄减薄技术是集成电路薄型化发展的关键技术,它直接影响电路的质量和可靠性。文章从超薄圆片减薄中常见的圆片翘曲和边缘损伤造成的损失出发,分析了圆片翘曲和边缘损伤的原因,提出了相应的改善措施。     

CSP元件的返修过程

ＣＳＰ元件在返修领域给当今的电子工业带来许多挑战。为了能够成功地返修ＣＳＰ，返修设备制造商必须认真地考虑大家共同遵守的具体准则。文章主要讨论如何满足和超越ＣＳＰ元件的特殊需要，使大家在返修ＣＳＰ中更顺利。     

微波裸芯片临时封装夹具微波信号传输的优化

微波传输线是微波系统的重要组成部分。随着微波系统向高频化方向发展,传输线中的不连续带来的信号完整性问题越发凸显并受到广泛的关注。针对微波裸芯片临时封装夹具系统,设计了适合2~6 GHz频段的微波传输线,通过三维电磁仿真软件(HFSS)对传输线的传输性能进行了仿真验证;并由先进设计系统(ADS)软件提取了临时封装夹具中微波传输路径的等效RLC电路参数模型。最终得到的传输结构S11小于-15 dB,S21大于-1 dB,符合良好匹配传输线的要求。     

2.5D封装结构回流焊过程热应力分析

对一种典型2.5D封装结构在回流焊工艺过程的热应力进行仿真。通过对比分析传统热力学仿真方法与基于生死单元技术的热力学仿真方法,研究了计算方法对热应力计算结果的影响。在相同参考温度下,由不同计算方法得到的硅通孔(TSV)转接板应力结果相差不大,从焊球应力结果可推测出,基于生死单元技术的热力学仿真方法考虑了残余应力的累积模拟更适合于回流焊过程的热应力仿真。研究了2.5D封装回流焊过程中参考温度的选择对计算结果的影响,选用最高参考温度作为各个组件的参考温度,通常得到TSV转接板的应力值偏大,模拟的结果会更加偏于激进。通过对2.5D封装结构回流焊过程进行热应力分析,对比分析了计算模拟方法和参考温度的选择对最终计算结果的影响。该方法同样可用于指导其他同类2.5D封装结构应力的计算和分析。     

BGA多芯片组件及三维立体封装(3D)技术

本文主要对BGA多芯片组件技术和三维立体(3D)封装技术进行了浅析,同时简述了它们的主要特点及应用前景。     

Economic Analysis of Test Process Flows for Multichip Modules Using Known Good Die

The cost and quality of a multichip assembly is highly dependentupon the cost and quality of the incoming die. In the case of a baredie assembly, it is often highly desirable to use either Known Good Die(KGD) or die that have been burned-in and tested to the same level ofquality and reliability as their packaged die equivalents. However,performing full bare die burn-in and test may not always becost-effective. This paper examines the question of whether it isalways necessary to use KGD to produce a cost-effective multichipmodule (MCM) of acceptable quality. A process-flow based cost modelis used to compare the cost and quality of MCMs assembled with KGD toMCMs assembled with die that have received wafer-level test only. Inaddition to test effectiveness at the wafer, die, and module level,factors that are considered include die complexity (size and I/O), number of die per MCM, the cost of producing the KGD, andrework costs and effectiveness. The cost model captures inputs fromwafer fabrication through MCM assembly and rework. Monte Carlosimulation is used to account for uncertainty in the input data.The resulting sensitivity analyses give final MCM cost and quality asa function of the various factors for both KGD and die that havereceived wafer-level test only.     

3D叠层封装集成电路的芯片分离技术

3D叠层封装是高性能器件的一种重要的封装形式,其鲜明的特点为器件的物理分析带来了新的挑战.介绍了一种以微米级区域研磨法为主、化学腐蚀法为辅的芯片分离技术,包括制样方法及技术流程,并给出了实际的应用案例.该技术实现了3D叠层芯片封装器件内部多层芯片的逐层暴露及非顶层芯片中缺陷的物理观察分析,有助于确定最终的失效原因,防止失效的重复出现,对于提高集成度高、容量大的器件的可靠性具有重要的意义.     

3D Printing Thermally Stable High-Performance Polymers Based on a Dual Curing Mechanism

High-performance polymers are an important class of materials that are used in challenging conditions, such as in aerospace applications. Until now, 3D printing based on stereolithography processes can not be performed due to a lack of suitable materials. There is report on new materials and printing compositions that enable 3D printing of objects having extremely high thermal resistance, with Tg of 283 °C and excellent mechanical properties. The printing is performed by a low-cost Digital Light Processing printer, and the formulation is based on a dual-cure mechanism, photo, and thermal process. The main components are a molecule that has both epoxy and acrylate groups, alkylated melamine that enables a high degree of crosslinking, and a soluble precursor of silica. The resulting objects are made of hybrid materials, in which the silicon is present in the polymeric backbone and partly as silica enforcement particles.     

提高微波器件封装可靠性的工艺研究

分析了微波外壳产生失效的主要原因,针对其在制备过程中的关键工艺以及技术难点展开讨论.分别论述了影响外壳可靠性的各个关键因素以及影响机理,包括瓷件尺寸精度和平整度、金属化强度与钎焊技术等,结合现有的工艺情况,分别提出相应的控制措施,并取得良好的效果.     

3D芯片封装晶圆植球装备关键技术研究

为了应对半导体芯片高密度、高性能与小体积、小尺寸之间日益严峻的挑战,3D芯片封装技术应运而生.从工艺和装备两个角度诠释了3D封装技术;介绍了国内外3D封装技术的研究现状和国内市场对3D高端封装制造设备植球机的需求.介绍了晶圆植球这一3D封装技术的工艺路线和关键技术,以及研制的这一装备的技术创新点.以晶圆植球机X-Y-θ植球平台为例,分析了选型的技术参数.封装技术的研究和植球机的研发,为我国高端芯片封装制造业的同行提供了从技术理论到实践应用的参考.     

扬声器用胶过程控制的讨论

着重介绍了扬声器用胶过程控制的有关问题,其中说明了使用胶粘剂的种类和部位,讨论了扬声器用胶在实际过程中,如何进行过程控制的问题。     

一种新型金属表面安装外壳的设计与制作

介绍了表面安装技术的优点及特点；详细介绍了一种新型外壳的结构设计及制作工艺；给出了实验结果。     

Tailored and Highly Stretchable Sensor Prepared by Crosslinking an Enhanced 3D Printed UV-Curable Sacrificial Mold

Taking advantage of unlimited geometry design, 3D printed sacrificial mold cast with highly conductive polymer composites is used to prepare a sensor with designed structures. However, the disposal of the mold in a mild condition while the refined structures can be maintained is still a challenge. Herein, a bifunctional monomer hydrolyzable hindered urea acrylate is synthesized to create a cross-linked polymer network, preventing the dissolution of printed parts in the uncured resin. 3D printed scaffolds can be hydrolyzed in hot water, which provides an attractive option for sacrificial molds. Also, a porous flexible strain sensor (PFSS) is fabricated by casting polyurethane/carbon nanotubes composites into the sacrificial molds, which demonstrates a high stretchability (≈510%) and an excellent recoverability. Meantime, the pressure sensitivity (0.111 kPa⁻¹) and a long-term electrical resistance of PFSS is characterized. The resistance response signal remains nearly unchanged after 100 compressive loading cycles at a large strain of 60%. Benefiting from the design freedom of 3D printing, a practical application of the PFSS with a complex and customized structure to monitor human motion is demonstrated. These results prove that the sacrificial molding process has great potential for user-specific stretchable wearable devices.     

Transient Characteristics of a Two-Phase Thermosyphon Loop for Multichip Module

A new thermosyphon cooling module (TSCM) has been designed, fabricated and tested to cool the multi-chip module plugged into a planar packaging system. The cooling module consists of a cold plate and an integrated condenser. With an allowable temperature rise of 56°C on the surface of the heater, the cooling module TSCM can handle a heat flux of about 2.7 W/cm² using R11 as working fluid. The transient characteristics of the cooling module have been proved to be excellent: that is, when a heat load is applied inside of the system, steady state can be achieved within 10 to 15 minutes. It has been found that the length of the vapor channel between the cold plate and the condenser in addition to the ambient and the condenser temperatures affect the system performance.