Knoeledge of PCB Microsection
2018-11-23 17:30Writer: qyadminReading:
PCB Microsection production process ( a ) :
A sampling : Samples should be representative and smooth. The cut surface of the sample with three smooth advantages: the smaller the deformation of the sample (1 ) forming ; shorter ( 2 ) spent on the subsequent grinding and polishing time ; less ( 3 ) used in the production process media .
2 , inserts buried : the sample buried in a resin ( resin or cold buried crystal resin adhesive ) , to ensure easy production of the subsequent polishing and improve the accuracy of the final result of the sample specimen . Insert into cold buried underground , buried and vacuum heat inlay buried three ways.
Cold buried : the sample is placed in a mold , then put a stirred mixture of a resin and a hardener is poured into a mold , and then at room temperature , under atmospheric pressure to harden into a solid transparent body , this insert is buried economical way to use.
Vacuum inserts buried : inlaid buried vias many and specifically for small samples . Under vacuum, to better penetrate into the pores of the resin gap to better maintain the initial sample plateau structure to avoid making the subsequent polishing process , the abrasive particles are embedded in the sample affect the fidelity of the experimental data .
Heat buried : buried thermal machine at high temperature and pressure conditions, to complete the process of thermal buried . Hot buried process requires fast but good thermal buried effect. But for heat sensitive samples prone to deformation due to heat hot buried unsuitable treatment .
3 , grinding : the fixed abrasive grinding disc ( using conventional abrasive sandpaper ) to remove the excess on the part of the sample specimen , so that the sample reaches state investigators need. Grinding mill is divided into two parts coarse and immature . The larger abrasive particles , abrasive rate is higher.
Note: The grinding process is likely to cause deformation of the sample specimen , so the grinding process , the contact force between the grinding disc and the sample should not be too large . Especially fine analysis process , should be a slow and gradual process .
4 , polishing : polishing powder is placed in a small amount of the polishing cloth , then the sample was placed on a rotating mirror polishing cloth , the polishing object is to remove the grinding process of deformation and scratches , whereby the mirror surface free of scratches , while allowing micro- structure analysis under a microscope.
Metallurgical tips ( b ) :
Cut: After formation of a representative sample obtained for the sample specimen to obtain a more desirable , the most suitable method of cutting an abrasive wet cutting