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Precautions for opening moisture sensitive components

Precautions for opening moisture sensitive components

(1) Observe the humidity indicator card attached to the bag when opening. The humidity indicator card is a card used to display the humidity condition of the sealed space. The percentage data above or to the side of the circle is the relative humidity data indicated by the corresponding circle.
There are many varieties of humidity indicator cards, the most common one is six-ring type, as shown in Figure 1. The six-ring display humidity is 10%, 20%, 30%, 40%, 50% and 60%. When not absorbing moisture, all the circles are blue, and when they are hydrated, they turn pink. The relative humidity indicated is the percentage of the lavender circle between the pink circle and the blue circle. For example, 20% of the circles turn pink, 40% of the circles still show blue, and 30% of the circle between the blue and pink showing lavender is the phase and humidity value.

(2) When using the components for unsealing, first observe the humidity indicator card attached to the package. If all the circles are blue, it means that all SMDs in the package are dry and can be used with confidence; if only 10% and 20 The % circle turns pink and is safe; if 30% of the circle also turns pink, it means that the SMD in the package is hygroscopic and indicates that the desiccant has deteriorated; if all the circles turn pink, That is to say, all the SMDs in the package have been seriously hygroscopic, and all the SMDs in the package must be hygroscopically dried before being welded.

(3) The operation after the package is opened. After the SMD bag is opened, it should be taken at speed as follows.
The environment of the production site is room temperature below 30 ° C. If it cannot be used up, it should be stored in a dry box with RH 20%.

(4) How to save the remaining SMD. If the components after unsealing cannot be used within the specified lifetime of the site, the following methods should be used for storage.
1 The SMD that is temporarily unused after the opening is stored together with the feeder in a dedicated low-temperature and low-humidity storage box, but the cost is high.
2 As long as the original moisture-proof packaging bag is not damaged, and the desiccant inside is good, all the circles on the humidity indicator card are blue, throwing the unsold SMD into the bag, and then sealing it for storage.

PCB assembly