Motherboard slicing test

The YOUHONGXIN SMT Laboratory focuses on the testing needs of electronic components and can conduct comprehensive testing from solder paste characteristics, solderability to internal packaging defects, such as:Motherboard slicing testBy integrating non-destructive and destructive technologies such as X-ray testing, and relying on excellent instruments and precise analysis, we provide strong guarantees for product quality.

The practical use of slice testing

Motherboard slicing testIt is one of the main conventional methods in the quality inspection of electronic components.

PCB structural defect inspection: such as PCB delamination, hole copper breakage and other internal issues, which are not visible to the naked eye but can be easily seen after slicing

PCBA soldering quality inspection:

Check BGA for issues such as empty soldering, virtual soldering, holes, bridging, etc

Analyze whether the tin plating area meets the standard

For example, I saw a case before where through slicing, it was found that there was no tin coverage at the corner of the PCB plug-in hole, resulting in poor soldering

Product structure analysis:

Analysis of Capacitors and PCB Copper Foil Layers

Analysis of LED Structure

Analysis of Electroplating Process

Analysis of internal structural defects in materials

Micro size measurement: capable of accurately measuring pore size, tin plating height, copper foil thickness, etc. (generally larger than 1 μ m in size)

Verify the results of non-destructive testing: for example, after discovering abnormalities in X-ray or SAM testing, use slices to verify whether there is really a problem

The data that slice testing can provide

Slice testing not only allows us to see the internal structure, but also provides very specific data:

Morphological photo: Clearly display the cross-sectional structure after slicing

Defect size data: such as crack length, layer thickness, pore size, etc

Welding quality data: soldering height, copper foil thickness, BGA solder joint quality, etc

Structural analysis data: such as analysis results of capacitors and PCB copper foil layers

Process validation data: used to evaluate whether the SMT process meets the standards

If there is a leakage in the capacitor, a 45 ° crack was found through slicing, which is a typical stress crack and directly locates the root cause of the problem.

Slice testing has a characteristic: it belongs to destructive testing, so it is generally verified only after abnormalities are found in non-destructive testing such as appearance inspection and X-ray. This is also why the execution time of slice testing is relatively long (at least 2-3 days), because the glue filling action takes 4 hours.

Specific methods for defect analysis in slice testing

Slice testing, as an important quality inspection method for electronic components, has a wide range of defect analysis methods. Based on industry practice, specific methods include:

1. Microscopic observation analysis method

This is a basic and commonly used method:

Optical microscope (OM) observation: used for preliminary observation of PCB layers, circuit layout, component installation positions, etc. It can detect obvious defects such as circuit breaks, short circuits, and solder joints

Metallographic microscope observation: Provides higher magnification observation, allowing for clear visualization of the internal structure and defects of solder joints

Stereoscopic microscope observation: suitable for observing the overall structure and macroscopic defects of the sample

2. Electron microscopy analysis method

With the development of technology, electron microscopy analysis has become mainstream:

Scanning Electron Microscopy (SEM) Observation: Provides high-resolution images that allow for clear observation of microscopic defects

Energy dispersive spectroscopy (EDS) analysis: used for quantitative analysis of element segregation, such as detecting the distribution of tin, silver, and copper in solder joints