How to identify fake electronic parts?

Here, we will discuss several test methods that are available to identify fake electronic parts. Every manufacturer should employ such techniques to avoid the use of counterfeit parts.

1.Visual examination

Checking for counterfeits begins with a visual inspection. This involves checking the part number present on the component against shipping documentation. The validity of the date code is examined using the previous data and past products bought from the supplier. There are some other aspects of visual checking which are as follows:

*Fraudsters use blacktopping to put a different part number and date code on the component. It involves applying a thin black epoxy coating on the top of the part and roughening the surface to achieve the desired texture. It also comprises matching the font with the original. To identify the presence of blacktopping, the top of the component and surface texture examination is important. Along with that, it is necessary to compare the manufacturer’s symbols with a known authentic product. 

*The leads of the component should be checked for damage, re-tinning, etc. This is a part of the incoming inspection.

*Other factors to consider in a device are component orientation, general appearance, contacts conditions, and inconsistencies visible to the naked eye.

2.Electrical testing

Electrical testing for counterfeit electronic components involves validation of resistance and capacitance values along with full-functional analysis of active parts. Various contract manufacturers (CM) and third-party test labs have facilities for conducting E-test. For testing the complex product, expensive test setup, and programming expertise are essential that is only possible at OCM or some third-party labs.

3.X-ray inspection

X-ray inspection examines the hidden/internal properties of the component. Having a golden standard or a good known example is always beneficial when it comes to comparison. This method checks and verifies physical dimensions, lead frames, and bond wires. Moreover, it also examines all the components for any internal variations. 

 

4.XRF technique

 

XRF stands for X-ray fluorescence spectroscopy. This technique determines the elemental composition of the materials and is best for verifying RoHS compliance. 

 

5.Decapping

 

Decapping, also known as decapsulation, is the process that removes the protective cover of an IC for inspecting the micro-circuitry embedded on the underlying die. This method uses an acidic solution to etch an opening on the top of the plastic component to reveal internal semiconductor chip and bond wires. This allows for an accurate examination of photographic documentation, including fab line ID numbers and symbols.

 

6.Scanning acoustic microscope

 

Another method to discover blacktopping is scanning acoustic microscope (SAM). This test locates laser etching underneath the blacktopping. If the etching is found,  it is evident that resurfacing is done to cover the original marking. This method is non-destructive. Hence, if the component passes this test, it becomes usable.

 

7.Permanency marking test

 

This test investigates the resistance of part markings to solvents. For counterfeit detection, it is not a reliable test since most counterfeit markings are invisible to this process. This technique works well with ceramic semiconductors and checks whether a military-grade part marking complies with the standard. For more on mil spec boards, refer to military-grade PCB design rules and considerations.

 

8.Scrap test

 

Nowadays, counterfeiters are becoming aware of the acetone method for revealing blacktopping. Therefore, they have started using a different material that is resistant to acetone. As a result, the scrap test was discovered. This process uses a sharp blade to scrape the surface. If it leaves a scar or burns on the surface without flaking (peeling or cracking), then the surface is considered authentic. However, if the flaking is visible, then the part is considered as remarked or reworked. In some cases, the previous marking also becomes noticeable on the component.