How to deal with chip failure analysis? Third party testing unit

Date：2022-02-28 14:43:00Views：1201

Failure analysis is a necessary means to determine the failure mechanism of chip, which provides necessary information for effective fault diagnosis. Failure analysis provides necessary feedback information for design engineers to continuously improve or repair the chip design and make it more consistent with the design specification. With the continuous improvement of people's requirements for product quality and reliability, failure analysis is becoming more and more important. How to deal with chip failure analysis? Relevant data sorted out by the third-party testing unit are as follows:

Method 1: the surface abnormalities were observed by electron microscope

After the failed chip samples are in the hands of the chip manufacturer, the first thing to do must be to use a high magnification electron microscope to check whether there are abnormal problems on the chip surface at the physical level, such as cracks, tin connection, mildew and other abnormal phenomena.

Method 2: Xray check the chip package abnormality

The light intensity of X-rays will change after passing through substances with different densities. Without damaging the object to be measured, the image formed by using the contrast effect can show the internal structure of the object to be measured. In IC packaging, such as layer peeling, burst, cavity, wiring and other problems, Xray can be used for integrity inspection.

Method 3: CSAM scanning acoustic microscope

Scanning acoustic microscope uses the amplitude, phase and polarity changes generated by the reflection of high-frequency ultrasound on the discontinuous interface of materials to image. The typical Sam image shows the defect with a red warning color.

Sam and Xray are complementary methods. X-ray is not sensitive to stratified air. The resulting image is a composite of the sample thickness, and Sam can show the image of layers inside the sample in layers. Therefore, the integrity detection of welding layer, filling layer and coating layer is the advantage of Sam.

Method 4: laser-induced localization of leakage junction

Apply voltage to the IC to make a small current flow inside it. While detecting whether the small current changes, scan the chip surface with a laser. Because the laser beam is partially converted into heat energy in the chip, if there is a leakage junction inside the chip, the temperature at the defect will not be conducted and dispersed normally, resulting in the cumulative increase of the temperature at the defect and further changes in the resistance and current at the defect. Through the correspondence between the change area and the laser beam scanning position, the defect position can be located. This technology is a patented technology invented and applied for by NEC in Japan in the early years. It is called OBIRCH (voltage detection current change). Similar to this analysis method are TIVA (current detection voltage change) and VBA (voltage detection voltage change). These three analysis methods are essentially the same, It's just different detection methods to avoid patent infringement (TIVA is an American technology patent and VBA is a Singapore technology patent).

Of course, before X-ray, CASM and OBIRCH, you can gradually apply voltage to each pin and detect whether the current curve is abnormal, so as to roughly confirm whether the pin has the possibility of failure.After using X-ray and other methods to locate the defect area, the final round of image physical confirmation is carried out by using the method of mechanical section and corrosive solution section and microscope.

In summary, according to the failure mode and phenomenon, through analysis and verification, simulate and reproduce the failure phenomenon and find out the cause of failure. It has strong practical significance for improving product quality, technology development and improvement, product repair and arbitration of failure accidents. The company's testing services cover: electronic component testing and verification, IC authenticity identification, product design and material selection, failure analysis, function testing, factory incoming material inspection, tape braiding and other testing items. Welcome to call Chuangxin testing. We will serve you wholeheartedly.