How to control and protect the MSD component effectively!
How to control and protect the MSD component effectively
How to control and protect the MSD component effectively The influence to the qualified rate of SMT and the credibility of the product is not weaker compared with the ESD, so it is the responsibility of the SMT that can't be shirked to know the importance of the MSD, understand its damage principle, study the related standard, norm the controlling process of the MSD and avoid the unqualified rate leaded by the damaged component to improve the credibility of the product.
The development trend of the MSD
The problem to protect the MSD becomes urgency along with the development of the electronics manufacturing. The first, the creation and development of the newly information technical puts forward more strict request to the credibility of the electronics product. It is disallowed to exist obvious blemish rate leak to be checked in the assemble examinations because of the strict request of the blemish rate to the single product. The second, the usage quantity of the SMD increases continuously along with the development of the sealing and packing technology. For example, the shorter development period, the smaller packing sizes, the thinner partition, the usage of the new packing materials, the greater integrated circuit, etc. The third, it is affected more obviously along with the using quantity of the BGA and CSP packing material. Because this kind of packing machine tend to use the winding material and prolongs the exposition time of the component. The fourth, although the unleaded stick packing technique has controversy, it also will influence the grade of the MSD seriously along with its continuous adoption. The much higher refluxing temperature of the unleaded alloy may make the grade of the humidity sensitivity of the MSD descend 1 or 2 grades at least, so the quality of all the component should be re-confirmed.
The hybrid produce becomes more and more in PCB packing factory because more and more products are made according to the order and more and more materials are purchased in the market. Usually, the reduce of the product's quantity will lead the production line to change multifariously and at same time prolong the exposed time of the component with high humidity sensitivity. Many component already packed on the sticker have to be dismantled down whenever the production line changes for other products. That means, many component must be stored in the tray or winding material temporarily and it is possible that the humidity in it already exceeds its biggest capacity before it returns to the production line and be welded.
Added: Tuesday, November 28, 2006
Submitter: meilysha
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Related Link: Article from Autodry.net
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