Preparation method of sample for PCB hole copper grain analysis

Abstract

The invention discloses a preparation method of a sample for PCB hole copper grain analysis, which comprises the following steps: sample inlaying: wrapping a sample to be analyzed with epoxy resin, and curing for 8-12 hours by adopting a room temperature curing process; mechanical grinding and polishing: grinding to an area needing to be observed by adopting abrasive paper, and carrying out polishing operation by using a polishing solution; ion grinding: continuously bombarding the surface of the polished sample with an argon ion beam at a depth of 1-3 microns, and removing the influence of plastic deformation and strain twin caused by mechanical grinding and polishing; imaging observation: carrying out ion imaging observation on the cross section of the sample subjected to ion polishing by utilizing a focused ion beam. The ion polishing technology is introduced, obvious stress is not introduced, extension deformation of the hole copper is not caused in the polishing process, and the original state of the hole copper structure is kept; and introducing an ion imaging technology, identifying twin crystal, crystal grain and crystal boundary defects by utilizing orientation differences among crystal grains, and directly observing a sample subjected to ion polishing.

Description

technical field [0001] The invention relates to the technical field of sample preparation for hole copper grain analysis, in particular to a method for preparing a sample for PCB hole copper grain analysis. Background technique [0002] The reliability of PCB itself depends heavily on the reliability of through holes and blind holes, and the copper grain structure of through holes and blind holes is a key factor affecting their reliability. How to clearly and effectively observe the copper grains in holes is very important for the evaluation of the reliability of through holes and blind holes. [0003] At present, the usual practice in the industry is as follows: [0004] 1. Use epoxy resin glue to cold mount the sample to be analyzed; [0005] 2. Mechanically grind and polish the inlaid samples until a bright polished surface is formed; [0006] 3. Micro-etch the polished sample. There are many types of corrosive liquids. Generally, a mixture of water + ammonia + hydroge...

AI Technical Summary

Problems solved by technology

[0012] The technical problem to be solved in the present invention is to overcome the defective that prior art exists, the present invention proposes a kind of preparation method that is used for the sample of PCB hole copper grain analysis, the present invention introduces ion polishing technology, does not introduce obvious stress, so During the polishing process, the hole copper will not be extended and deformed, and the original state of the hole copper structure will be maintained; ion imaging technology will be introduced to use the orientation difference between grains to identify twins, grains, and grain boundary defects, and the sample does not need micro-etching treatment , direct observation of ion-polished samples

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