The Shelf Life and Store method of PCBs

What about the shelf life of PCBs and How to store the PCBs

 

After the final product inspection, then vacuum packaged and waiting for a delivery. So why should the Printed Circuit Boards(PCBs) be vacuum packaged? How are they stored after that? How long about shelf life? We will make a brief introduction about the storage and shelf life of the Printed Circuit Board(PCB).

 

Q1: Why should the PCBs be vacuum packaged?

 

If the PCBs are not sealed, its surface treatment (immersion gold or Hot Air Solder Leveling or Immersion Tin or Organic Solderability Preservatives etc.) on the soldering pads will be oxidized and that will lead severe problem during the assembly process.

 

Q2: How to store?

 

 The PCBs are not the same with other finished products. The contact with air and water is forbidden. Firstly, the vacuum package can not be damaged, layers of bubble film’s surrounding can be help keep PCBs dry, a small bag of desiccant will add to the performance. After sealing, the boxes must keep a distance from the wall, placed in the dry and ventilated room, and be away from direct sunlight. The temperature of the warehouse is best controlled at the range of  23 ± 3 , 55 ± 10% Relative Humidity.

 Under these conditions, the shelf life of the PCBs with Immersion Gold, Electro Gold, Hot Air Solder Leveling, Electro Silver surface treatment are about 6 months, for the surface treatment of Immersion Tin, Immersion Silver ,OSP the shelf life will be shorten to 3 months.If the PCBs would be put aside for a long time, we’d better apply the conformal coating on the PCBs in order to avoid the humidity, dust and oxidization. And this method can lengthen the shelf life to 9 months.


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