BGA preservation and use

BGA preservation and use

BGA device is a highly temperature sensitive element, so BGA must be kept at a constant temperature

drying conditions, the operating personnel should be strict compliance with the operating process,

avoid components in the assembly is affected. In general, the ideal environment for the preservation

of 200C-250C is BGA, the humidity is less than 10%RH (has better nitrogen protection).

In most cases, we in the packaging of components is not open before will pay attention to BGA

moisture treatment. At the same time, we should also pay attention to packaging of components

after being hit for the installation and welding process is not to be exposed to the time, to prevent

the components affected causes the welding quality decline or components of the electrical properties

of the change. The next table is humidity sensitive grade classification, which is shown in the assembly

process, once the seal moisture packaging is opened, the components must be used for the installation,

welding the corresponding time. Generally speaking, the BGA belongs to the humidity sensitive grade

of 5 levels.

If the use of components stored in the conditions of nitrogen, then the time can be extended to.

The effect of approximately every 4-5 hours of dry nitrogen can be prolonged by 1 hours of air exposure.

In the assembly process we often encounter such a situation, the components of the packaging is opened

cannot in the corresponding time after use and the time of exposure over the table 1 provides the time,

then before the next use in order to make the component has good solderability, we suggest to bake the

BGA components. Baking conditions: temperature 1250C, relative humidity is less than 60% RH.

Baking temperature most don't more than 1250C, because high temperature will cause solder and

components at the junction of the microstructure changes, and when these components into the

stage of reflow, easily lead to disconnection between the solder and components package, resulting

in SMT assembly quality problem, we will think is the components of quality problems caused by.

But the temperature of the roast is too low, then it can't play the role of the desiccant.. In the

conditions permit, we suggest that in the assembly components baking, is conducive to the

elimination of the internal moisture of the BGA and improve heat resistance of BGA, reducing

components into reflow by thermal shock on the device's influence. BGA components out of the

baking, natural cooling for half an hour before the assembly operation.