Detecting Die Surface Delamination, from the June 2002 COTS Journal. Copyright 2002 RTC Group. Used by permission.
Click here for a case study of an EEPROM bit loss failure that is delamination-related (pdf format). Copyright 2002 DM Data. Used by permission. For details or for newsletter info call DM Data at 480-451-7449.
Click here for a current article in CIRCUITS ASSEMBLY about moisture sensitive devices.
Flip Chip Defect Detection ,published in Advanced Packaging magazine, March 2002. (pdf format). Copyright 2002 by PennWell Corp. E-mail us if you would like a reprint.
A Case Study of PEMs Susceptible to Die Surface Delamination... (pdf format)
Acoustic MicroImaging in Electronics, Future Circuits, March 1999 (pdf format) Note: "C-SAM" is a registered trademark of Sonoscan, Inc.
Step-By-Step: Die Attach, March 1999 (pdf format)
Reprinted with the permission of 'Advanced Packaging' magazine. Copyright 1999 by IHS Publishing Group. All rights reserved.
Acoustic Microimaging helps assure reliability of plastic COTS parts (from Nov 99 Military & Aerospace Electronics), copyright 1999 PennWell Publishing. Used by permission
Acoustic Microscopy of Tightly Closed Delaminations in Multilayer Ceramic Chip Capacitors, Copyright 1999, AcousTech Inc. (pdf format)
Curious about how acoustic microimaging compares to x-ray? Click here for an informative article (Word format), originally published as a case study in Semiconductor Reliability News, March 2000. (E-mail us for more information about this newsletter.) Copyright 2000 AcousTech Inc.
Evaluation of an Automotive Fluid Line Assembly Using Acoustic Microimaging Originally presented at IAMIS 2000 (October 2000). Copyright 2000 AcousTech Inc. (pdf format)
A useful specification is IPC/JEDEC J-STD-035, "Acoustic Microscopy for Nonhermetic Encapsulated Electronic Components". To download it free (you will be required to register and create a login name), click here and go to the free standards.
We will evaluate your components to any specification or internal customer requirements, providing pass/fail judgement and complete documentation of results. Not sure which criteria to use? We can provide recommendations and help you develop criteria that fit your application. Commonly used standards for AMI and x-ray evaluation are:
IPC/JEDEC J-STD-035, “Acoustic Microscopy for Nonhermetic Encapsulated Electronic Components”
MIL-STD-883G Method 2012, “Radiography”
MIL-STD-883G method 2030, “Ultrasonic Inspection of Die Attach”
What is the difference between acoustic imaging, acoustic micro imaging, and scanning acoustic microscopy?
None. They are synonyms for the same nondestructive inspection technique. The acronyms AMI, SAM and C-SAM® are also frequently used and stand for Acoustic Micro Imaging, Scanning Acoustic Microscopy and C-mode Scanning Acoustic Microscopy, respectively. The term “ultrasonic testing” is sometimes used to describe this technique as well, but can also be used in reference to macro systems designed for inspecting larger items, such as structural components of vehicles or aircraft, using lower frequencies. The term “Sonoscan testing” is often used as another synonym for acoustic micro imaging. Sonoscan® and C-SAM® are registered trademarks of Sonoscan Inc, the inventer of this inspection technology and a primary provider of acoustic microscopy systems.
What advantages does acoustic micro imaging offer over x-ray?
The two techniques are complementary, each with its own advantages and limitations. Click here for a case study that highlights some of the differences.
Is it necessary to immerse parts in a liquid in order to scan them acoustically?
Yes. At the frequencies used in acoustic micro imaging (typically 10 MHz to 300 MHz), a coupling medium is required in order to get the ultrasound to the part under test. DI water is the most commonly used medium.
Is red always bad in the acoustic image?
No. A variety of color maps can be applied to highlight defects in an image. It is important to evaluate the actual echo waveforms to determine the nature of a particular feature. Click here for an example showing the difference that proper and improper color map choices can make in an acoustic image.
Can acoustic micro imaging be used to evaluate components mounted to a printed circuit board?
Yes. In fact, this is preferable when performing acoustic imaging as an initial step in a failure analysis, since desoldering parts may cause or increase internal delamination.
Can scanning acoustic microscopy be used to evaluate the solder ball attachment of a BGA to a printed circuit board?
Because acoustic imaging excels at identifying interfacial delamination and cracking, evaluation of the solder ball integrity in a mounted BGA would appear to be an ideal application. However, the practical limitations involved in penetrating multiple layers (either through the BGA substrate or the PCB) typically prevent a meaningful analysis of the solder balls. High-resolution real-time x-ray inspection is often a better solution in this case. An additional issue with BGA devices is that they tend to be particularly sensitive to moisture related damage during soldering if not properly handled. Acoustic imaging is an excellent technique for evaluating whether moisture related damage has occurred.
Click here for more information.