ENEPIG控制以获得优良封装基板表面处理焊区

本文针对ENEPIG(化镍钯浸金)技术应用于封装基板表面处理,在化镍钯浸金工艺过程中,通过对镍层上化学镀钯控制、浸金控制,获得精确的沉积厚度和金层均匀性,达到良好的接触面。并就浸金过程中的渗金问题进行优化控制,达到焊区小间距的需求。通过对ENEPIG表面处理焊区和电镀镍金表面处理焊区的Wire Bonding(引线键合)能力、可焊性、抗老化能力进行试验比较,验证了本ENEPIG控制技术同时具有优于电镀镍金的引线键合可靠性和锡焊可靠性。本ENEPIG控制技术所获得优异可靠性的表面处理,并且满足无铅组装工艺所有需求,非常适用于封装基板的表面处理制造。     

挠性电路板化学镍钯金工艺技术研究

主要对化学镍钯金表面处理工艺原理进行介绍,通过挠性电路板化学镍钯金后引线健合能力、可焊性、抗老化等一系列可靠性测试,验证其相对其它表面处理技术更加优越,特别适用于表面贴装混合组装板等要求高连接可靠性的产品上,并且满足无铅组装工艺所有需求,非常适合挠性板、封装基板等的表面处理PCB制造。     

三维闪存封装基板球焊表面处理技术应用探讨

封装基板是三维闪存封装的重要原材料之一,其与外部电路连接的焊接区域所用表面处理工艺对封装体与主板连接的可靠性以及封装成本都有重要影响。目前常用表面处理工艺中,OSP工艺具有制作成本低、焊盘表面平整度高、加工时的能源消耗少等优点,在对封装成本比较敏感的三维闪存产品上得到广泛的应用。随着OSP可焊性和耐高温性能的显著提高,未来OSP在三维闪存封装基板上的应用将更加广泛,技术也将更加成熟。本文通过对基板表面处理工艺及三维闪存封装特点的综合分析,探讨适合三维闪存封装基板球焊表面处理工艺,展望相应表面处理工艺的发展。     

基于有机基板的化学镍钯浸金工艺应用与测评

有机基板被广泛应用于电子封装领域,常见的表面处理工艺包括电镀镍金、化学镍金、浸锡、浸银等工艺。在众多表面处理工艺中,化学镍钯浸金工艺因其具有较好的综合性能展现出显著优势。化学镍钯浸金工艺是在化学镍金工艺的基础上增加化镀钯处理,采用该工艺先对基板表面进行化镀镍处理,再进行化镀钯处理,最后完成化学浸金处理。钯镀层可以防止金在沉积过程中腐蚀镍镀层以及阻挡镍向金属间化合物（IMC）层扩散。利用X-Ray、电子扫描显微镜（SEM）、聚焦离子束（FIB）等图像分析方法,对比了不同厂商的化学镍钯浸金镀层的厚度、微观形貌及质量,结果表明,平整且致密的钯镀层可以有效避免镍腐蚀现象。     

表面处理工艺的新发展简

文章简述了当下流行的有机涂覆（OSP）、化学镀镍浸金（ENIG）、化学镀镍镀钯浸金（ENEPIG）等表面处理技术的发展现状;并对浸银（IAg）、浸锡（ISn）和直接浸金（DIG）以及自组装单分子（SAM）等新工艺进行了简单讨论,并提出了一些降低工艺成本,改进技术,提高工艺可靠性的方法。     

化学镀镍钯金电路板金丝键合可靠性分析

在微组装工艺应用领域，为保证印制电路板上裸芯片键合后的产品可靠性，采用化学镀镍钯金工艺（ENEPIG），可在焊接时避免“金脆”问题、金丝键合时避免“黑焊盘”问题。针对化学镀镍钯金电路板的金丝键合（球焊）可靠性进行了研究，从破坏性键合拉力测试、第一键合点剪切力测试以及通过加热条件下的加速材料扩散试验、键合点切片分析、键合点内部元素扫描等多方面分析，与常规应用的镀镍金基板键合强度进行了相关参数对比，最终确认了长期可靠性满足产品生产要求。此外，对镍钯金电路板金丝键合应用过程中需要注意的相关事项进行了总结与说明。     

化学镀镍钯金LTCC基板工艺研究

为降低LTCC基板加工材料成本,在全银基板上化学镀镍钯金(ENEPIG)方案具有明显的成本优势和工艺优点.本文从银导体烧结形貌出发,对比了不同阻焊材料的抗酸碱腐蚀性,分析了内层银导体厚度对基板平面度的影响.针对化学镀存在的金层渗镀和漏镀、陶瓷腐蚀、镀层剥离、金层发白和色斑等问题,从机理上分析了问题产生的原因,提出了有针...     

化学镀镍浸金和化学镀镍镀钯浸金表面处理工艺概述及发展趋势

当今电子信息产品便携小巧、功能多样的发展趋势,推动了其所需PCB产品向轻薄、信号传送速度更快的方向发展,这对PCB表面处理工艺的稳定性、可靠性提出了新的挑战。另一方面,欧盟在2003年制定的RoHS、WEEE等规范都旨在消除电子产品中铅、汞等有害的物质,推动了PCB表面处理技术向绿色无铅化方向发展。化学镀镍浸金(简称ENIG)和在其基础上发展的化学镀镍镀钯浸金(简称ENEPIG)表面处理技术可以适应PCB精细线路多类型元件的无铅焊接装配要求。上述两种表面处理技术克服了由无铅工艺带来的诸多问题,但其自身也面临如何进一步降低成本和技术难度,提高工艺可靠性等一系列问题。     

塑封互联MIS高可靠性封装及板级封装新技术

塑封互联MIS技术是一种高性能、高可靠性封装基板及板级嵌入式封装技术,其灵活的布线及特有的材料结构及工艺特点,结合MIS基板中铜布线超粗化等表面处理工艺,在电、热性能及可靠性方面相比现有BGA、QFN等封装凸显出显著的优势。基于MIS工艺的灵活性,目前在封装领域尤其在嵌入式封装、系统级封装等方面表现优异,已广泛应用于手机、工业控制、IOT等电子产品的射频类、电源管理类器件的封装中。文章对MIS技术主要工艺流程、技术特点、在各类封装中的应用、电热性能等进行了阐述。     

超小型片式元件表面组装对策

超小型片式元件体积小、重量轻、给表面组装工艺增加一定难度。影响超小型片式元件表面组装质量的工艺因素很多,但主要是:焊膏印刷、粘接剂涂布、片式元件贴装、焊接、电路基板在线检测手段及焊后修复六种,应分别采取相应的措施,使表面组装质量得到保证。     

化学镍/化学钯/浸金的表面涂覆层的可焊性和可靠性

概述了化学镍/化学钯/浸金(ENEPIG)表面涂(镀)覆层的优点。它比化学镍/浸金(ENIG)有更好的可焊接性和焊接可靠性。化学镍/化学钯/浸金表面涂(镀)覆层应该是有发展前景的。     

Review of Capabilities of the ENEPIG Surface Finish

Surface finishes are used to protect exposed copper metallization in printed circuit boards from oxidation and to provide a solderable surface on which to mount electronic components. While it is true that some people have called electroless nickel electroless palladium immersion gold (ENEPIG) a “universal finish” for a wide range of applications from wire bonding to solder interconnects, this paper provides a review of the current literature on ENEPIG and assesses its overall capabilities compared to other surface finishes. Gaps in understanding the performance of ENEPIG as a printed wiring board surface finish are identified and further testing is recommended.     

适用于IC封装的表面涂覆层——化学镀镍、钯、金的未来

概述了化学镀镍/化学镀钯/浸金涂（镀）覆层的优点,它比起化学镀镍/浸金,不仅更适用于IC封装,而且提高了可靠性,降低了成本。     

Interfacial reaction and mechanical evaluation in multi-level assembly joints with ENEPIG under bump metallization via drop and high speed impact test

The criteria of mechanical reliability in solder joints can be identified and described by comparative evaluation via drop test and high speed pendulum impact test. Systematic samples of assembly and attachment joints with various Pd additions were employed and investigated in this study. The statistical values of mechanical performances were calculated and compared. Better high speed impact performance of SAC305/ENEPIG attachment joints with 0.06 μm Pd layers was confirmed owing to the single Cu₆Sn₅ phase growth. However, the comparative measurement of the better performance on drop testing exhibited in ENEPIG/SAC305/immersion Sn assembly joints with 0.1 μm Pd layers deposit resulted from the thinner and layer-type IMC growth. The correlation between the cracks propagation and Pd addition was established on the basis of the elemental X-ray color mapping via Field-Emission Electron Probe Microanalyzer (FE-EPMA). It is expected that through comparison between impact and drop test in mechanical reliability, a criterion of joints reliability can be established. Besides, the optimal Pd layer deposit for the ENEPIG surface finish in the attachment and assembly solder joints was demonstrated and confirmed.     

Comparative Study of ENIG and ENEPIG as Surface Finishes for a Sn-Ag-Cu Solder Joint

Interfacial reactions and joint reliability of Sn-3.0Ag-0.5Cu solder with two different surface finishes, electroless nickel-immersion gold (ENIG) and electroless nickel-electroless palladium-immersion gold (ENEPIG), were evaluated during a reflow process. We first compared the interfacial reactions of the two solder joints and also successfully revealed a connection between the interfacial reaction behavior and mechanical reliability. The Sn-Ag-Cu/ENIG joint exhibited a higher intermetallic compound (IMC) growth rate and a higher consumption rate of the Ni(P) layer than the Sn-Ag-Cu/ENEPIG joint. The presence of the Pd layer in the ENEPIG suppressed the growth of the interfacial IMC layer and the consumption of the Ni(P) layer, resulting in the superior interfacial stability of the solder joint. The shear test results show that the ENIG joint fractured along the interface, exhibiting indications of brittle failure possibly due to the brittle IMC layer. In contrast, the failure of the ENEPIG joint only went through the bulk solder, supporting the idea that the interface is mechanically reliable. The results from this study confirm that the Sn-Ag-Cu/ENEPIG solder joint is mechanically robust and, thus, the combination is a viable option for a Pb-free package system.     

化学镀镍/化学镀钯/浸金表面涂覆层的再提出

文章概述了化学镀镍/化学镀钯/浸金表面涂(镀)覆层的特性.不仅它能够满足各种各样的类型元件和安装工艺的要求,而且也能满足高密度的IC基板封装的要求.因而,化学镀镍/化学镀钯/浸金表面镀层是一种"万能"的镀层,具有最广泛的应用前景.     

Mechanisms and solutions to the brittle solder joint in electroless Ni plating

Brittle solder joints in Electroless Ni electroless Pd immersion Au (ENEPIG) surface finishes are one of the key reliability issues in electronics assembly. Previous characterization of the reflow process has indicated that interfacial voids formed after solder reflow are responsible for the decreases in solder joint strength. However, the mechanisms behind the formation of these voids in the ENEPIG process remain unclear. In this paper, the interaction between various aspects of the ENEPIG process and solder joint strength were investigated. Surface roughness, morphology, and nano-pitting at the interface between electroless Pd and Ni-P were characterized. The size and density of nano voids inside Ni₂SnP were measured after the specimens were reflowed with Sn4Ag0·5Cu solder ball. Additionally, high speed shear solder joint strength measurements were made. The results indicated that anion adhesion induced nano-pitting at the interface between the Ni₂SnP intermetallic and Pd, resulting in the formation of a nano void layer during reflow. These interfacial voids lead to lower solder joint strength. Based on the results, a solution to prevent the brittle solder joint failures is suggested.     

半导体晶圆ENIG/ENEPIG产品设计考量

通过化学自催化反应在半导体晶圆I/O铝或铜金属垫上沉积具有可焊接性的镍金/镍钯金层,此工艺已在MOSFET、IGBT、RFID、SAW Filter等产品上得到广泛应用。着重阐述了在新产品设计和工程评估阶段,对于晶圆产品本身应予以考量的因素,如钝化层种类及厚度,I/O金属垫的成分及结构,切割轨道上金属图形的大小及钝化层的覆盖,不同I/O pad的电势等。其中一些因素导致的问题会直接影响化学镍金/镍钯金后产品的性能应用。在化镀工艺过程中,要充分了解产品本身结构以及可能造成的相应缺陷及问题,并且应综合考虑这些因素的影响。     

IC封装载板的新型表面涂饰层——ENEPIG

文章介绍一种新型的化学镀镍化学镀钯与浸金表面涂饰层,克服了化学镀镍浸金涂层的缺点,更加适合于IC封装载板上应用。