Interfacial Delamination in Plastic Encapsulated Integrated Circuits (Pics)

1996 ◽  
Vol 445 ◽  
Author(s):  
Nickolaos Strifas ◽  
Aris Christou

AbstractThe reliability of plastic packaged integrated circuits was assessed from the point of view of interfacial mechanical integrity. It is shown that the effect of structural weaknesses caused by poor bonding, voids, microcracks or delamination may not be evident in the electrical performance characteristics, but may cause premature failure. Acoustic microscopy (C-SAM) was selected for nondestructive failure analysis of the plastic integrated circuit (IC) packages. Integrated circuits in plastic dual in line packages were initially subjected to temperature (25 °C to 85 °C) and humidity cycling (50 to 85 %) where each cycle was of one hour duration and for over 100 cycles and then analyzed. Delamination at the interfaces between the different materials within the package, which is a major cause of moisture ingress and subsequent premature package failure, was measured. The principal areas of delamination were found along the leads extending from the chip to the edge of the molded body and along the die surface itself. Images of the 3-D internal structure were produced that were used to determine the mechanism for a package failure. The evidence of corrosion and stress corrosion cracks in the regions of delamination was identified.

Author(s):  
L. Meng ◽  
J.C.H. Phang ◽  
A.G. Street

Abstract The capability of the Scanning Electron Acoustic Microscopy (SEAM) technique for high resolution non-destructive subsurface imaging at different depths for a multi-level integrated circuit is assessed. Experimental results using a beveled DRAM IC sample are used to quantify the effect of the electron beam energy and modulation frequency on contrast, spatial resolution and depth of focus of SEAM amplitude and phase images.


Author(s):  
James Vickers ◽  
Seema Somani ◽  
Blake Freeman ◽  
Pete Carleson ◽  
Lubomír Tùma ◽  
...  

Abstract We report on using the voltage-contrast mechanism of a scanning electron microscope to probe electrical waveforms on FinFET transistors that are located within active integrated circuits. The FinFET devices are accessed from the backside of the integrated circuit, enabling electrical activity on any transistor within a working device to be probed. We demonstrate gigahertz-bandwidth probing at 10-nm resolution using a stroboscopic pulsed electron source.


2020 ◽  
Author(s):  
Daniel Marolt

After more than three decades of electronic design automation, most layouts for analog integrated circuits are still handcrafted in a laborious manual fashion today. This book presents Self-organized Wiring and Arrangement of Responsive Modules (SWARM), a novel interdisciplinary methodology addressing the design problem with a decentralized multi-agent system. Its basic approach, similar to the roundup of a sheep herd, is to let autonomous layout modules interact with each other inside a successively tightened layout zone. Considering various principles of self-organization, remarkable overall solutions can result from the individual, local, selfish actions of the modules. Displaying this fascinating phenomenon of emergence, examples demonstrate SWARM’s suitability for floorplanning purposes and its application to practical place-and-route problems. From an academic point of view, SWARM combines the strengths of procedural generators with the assets of optimization algorithms, thus p...


1997 ◽  
Vol 5 (2) ◽  
pp. 18-19
Author(s):  
Jeffrey A. Mittereder

The following is a technique for analyzing the area underneath a GaAs integrated circuit or discrete device which may aid in failure analysis. This procedure has been used in the past by the microelectronics community, and it is reviewed here for GaAs monolithic microwave integrated circuits (MMICs) and discrete devices. Because it is a destructive method, we use it in our lab after all other testing is completed. The substrate thickness of the GaAs is ∼4 mils (25 μm).


Author(s):  
Ann N. Campbell ◽  
William F. Filter ◽  
Nicholas Antoniou

Abstract Both the increased complexity of integrated circuits, resulting in six or more levels of integration, and the increasing use of flip-chip packaging have driven the development of integrated circuit (IC) failure analysis tools that can be applied to the backside of the chip. Among these new approaches are focused ion beam (FIB) tools and processes for performing chip edits/repairs from the die backside. This paper describes the use of backside FIB for a failure analysis application rather than for chip repair. Specifically, we used FIB technology to prepare an IC for inspection of voided metal interconnects (“lines”) and vias. Conventional FIB milling was combined with a superenhanced gas assisted milling process that uses XeF2 for rapid removal of large volumes of bulk silicon. This combined approach allowed removal of the TiW underlayer from a large number of M1 lines simultaneously, enabling rapid localization and plan view imaging of voids in lines and vias with backscattered electron (BSE) imaging in a scanning electron microscope (SEM). Sequential cross sections of individual voided vias enabled us to develop a 3D reconstruction of these voids. This information clarified how the voids were formed, helping us identify the IC process steps that needed to be changed.


2015 ◽  
Vol 2015 (1) ◽  
pp. 000696-000701 ◽  
Author(s):  
Nishant Lakhera ◽  
Tom Battle ◽  
Sheila Chopin ◽  
Sandeep Shantaram ◽  
Akhilesh K. Singh

Scanning acoustic microscopy (SAM) is the primary method to non-destructively detect internal defects in finished semiconductor packages. SAM is heavily used to detect interfacial delamination in the die-package system. Though this method can achieve an acceptable resolution to analyze the quality of the package unit, it is not absolute in all cases. SAM is also time consuming and non-predictable, as it offers a latent response of the finished good to the reliability tests. This paper presents an analytical prediction method defined to gauge whether the epoxy mold compound (EMC) encapsulating a no polyimide (PI) die surface would yield detectable delamination at the die to mold compound interface in the package finished good. The new method can be used to gauge whether top of die to EMC delamination will occur with a change in new wire bond (WB) die layout, new EMC material and new mold process. This new method also provides a way to demonstrate that the observed delamination is not detrimental to package reliability. This method will demonstrate how the no-PI package reliability can be met to not cause electrical failures based on the resin rich (RR) volume.


Author(s):  
Soon Lim ◽  
Jian Hua Bi ◽  
Lian Choo Goh ◽  
Soh Ping Neo ◽  
Sudhindra Tatti

Abstract The progress of modern day integrated circuit fabrication technology and packaging has made fault isolation using conventional emission microscopy via the top of the integrated circuit more difficult, if not impossible. This is primarily due to the use of increased levels and density of metal-interconnect, and the advent of new packaging technology, e.g. flip-chip, ball-grid array and lead-on-chip, etc. Backside photon emission microscopy, i.e. performing photon emission microscopy through the bulk of the silicon via the back of the integrated circuit is a solution to this problem. This paper outlines the failure analysis of sub-micron silicon integrated circuits using backside photon emission microscopy. Sample preparation, practical difficulties encountered and case histories will be discussed.


Author(s):  
S.P. Roberts ◽  
J.M. Patterson

Abstract Recent advances in integrated circuit technologies and in interconnect methodologies to external electronics have made it extremely difficult to conduct failure analysis from the top side of the die (1,2). Therefore analysis techniques are being developed that allow analysis from the backside of the die. The first step in this process involves gaining access to the back of the die through the packaging material. Most backside analysis techniques require that the die then be thinned and polished. This paper describes specialized equipment and procedures to meet those requirements. The equipment is relatively inexpensive compared to other approaches.


Author(s):  
L. A. Knauss ◽  
B. M. Frazier ◽  
H. M. Christen ◽  
S. D. Silliman ◽  
K. S. Harshavardhan ◽  
...  

Abstract As process technologies of integrated circuits become more complex and the industry moves toward flipchip packaging, present tools and techniques are having increasing difficulty in meeting failure analysis needs. One of the most common failures in these types of ICs and packages is power shorts, both during fabrication and in the field. Many techniques such as Emission Microscopy and Liquid Crystal are either not able to locate power shorts or are inhibited in their effectiveness by multiple layers of metal and flip-chip type packaging. A scanning SQUID microscope can overcome some of these difficulties. A SQUID (Superconducting Quantum Interference Device) is a very sensitive magnetic sensor that can image magnetic fields generated by magnetic materials or currents (such as those in an integrated circuit). The current density distribution in the sample can then be calculated from the magnetic field image, and resolutions approaching 5 times the near field limit can be obtained. We present here the application of a SQUID microscope to physical failure analysis and compare it with other techniques to detect shorted current paths in flip-chip mounted ICs and packages.


Author(s):  
John R. Devaney

Occasionally in history, an event may occur which has a profound influence on a technology. Such an event occurred when the scanning electron microscope became commercially available to industry in the mid 60's. Semiconductors were being increasingly used in high-reliability space and military applications both because of their small volume but, also, because of their inherent reliability. However, they did fail, both early in life and sometimes in middle or old age. Why they failed and how to prevent failure or prolong “useful life” was a worry which resulted in a blossoming of sophisticated failure analysis laboratories across the country. By 1966, the ability to build small structure integrated circuits was forging well ahead of techniques available to dissect and analyze these same failures. The arrival of the scanning electron microscope gave these analysts a new insight into failure mechanisms.


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