Fast Elemental Mapping of Electronic Components on a Printed Circuit Board (PCB) with micro-XRF on SEM

Element Recovery - Determine the Distribution of Trace Elements within Used Electronic Components 

The recycling of electrical components, such as Printed Circuit Boards (PCBs), is important for the recovery of the so-called “critical” elements that they contain. The recovery of these elements can be used to compensate for current shortfalls in mining output. Therefore, recycling is increasingly important as a source for the raw materials needed to produce new electronics and batteries as part of the modern-day energy transition.

In order for elemental recovery to be efficient and effective, it is important to be able to quickly and accurately identify which PCB components, such as transistors, capacitors or wires, contain which specific elements.

This application example demonstrates how elemental mapping of a PCB can be achieved without any sample preparation using high-speed micro-XRF on SEM (also known as SEM XRF). QUANTAX micro-XRF, Bruker's system for Micro-XRF on SEM, can be used for the elemental analysis of electronic components at trace element sensitivity. 

XTrace 2, the X-ray source in Bruker's QUANTAX micro-XRF system, is equipped with an Aperture Management System (AMS), that can maintain focus over a large working distance, thus allowing mapping to take place over these challenging 3-D samples. This is particularly beneficial for the imaging of samples with topographical features such as PCBs.   

The 50 kV Rh tube used in XTrace 2 also allows for the analysis and identification of high-energy elemental lines providing greater measurement confidence. 

Elemental mapping of a PCB, taken using micro-XRF on SEM, showing the elemental distribution of different circuit components. 

High-Resolution Elemental Mapping of 3D Features

The Aperture Management System (AMS) used in QUANTAX micro-XRF allows for the high-resolution mapping of samples with 3D features, such as electronic components. 

The Aperture Management System (AMS) in XTrace 2, the X-ray source used in QUANTAX micro-XRF,  facilitates the high-resolution mapping of elements in circuit features at varying working distances.

High Energy Lines for a More Accurate Elemental Analysis 

XTrace 2, the 50 kV X-ray source used in QUANTAX micro-XRF, excites samples to higher electronic energies. This is in turn results in emission from higher energy elemental lines. In this example these lines are Ag (Kα = 22.1 keV), Sn (Kα = 25.3 keV) and Ba (Kα = 32.2 keV). This additional data results in a more accurate elemental analysis. 


High-Energy portion of the spectrum taken using Micro-XRF on SEM. XTrace 2 facilitates the analysis of higher energy lines such as the silver, tin and barium lines shown here. The inlay shows how both major and trace elements can be detected using SEM XRF.