Influence of PCBs coatings wettability on lead-free SMT solder joints reliability
The paper presents results of wettability study of PCBs with immersion Sn, Ni/Au and SnCu coatings before reflow soldering process. Furthermore the solder joints were made in the optimal lead-free reflow soldering conditions using chosen materials with different wettability value of PCBs coatings and their reliability assessment was executed. The results of investigations have shown that exist direct influence PCBs coatings wettability on reliability of solder joints. It was find also that by using special procedure of PCBs coatings wettability assessment it is possible to predict future solder joints reliability.
Advantages of the wetting balance method for new lead-free materials evaluation
Electronic products in a market since the 1st of July 2006 will have to be devoid several dangerous substances, for example lead. The introduction of lead-free technology require searching new solder alloys and fluxes as well as necessity of the examine properties these materials. The Wetting Balance Method is method which makes possible the checking of wetting parameters of new lead-free materials as well as examining of mutual their co-operation in lead- free technology. The advantages and possibility of the above mentioned method will be shown in the article. The evaluation of new lead-free materials for assembly processes of electronics packages will be used as example of application this method in research process.
Flocculation tests with electrophoretically separated serum proteins.
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