Analysis of BGA welding process

Analysis of BGA welding process

"Desoldering device" is quite important operation and adjustment, the temperature, the second, air pressure,

must be clear, not casually, otherwise before result all abandon, even lead to damaged beyond repair Fruit,

so using the traditional type 850 "heat gun" will take care all the more, it's best to use a thermometer to

measure the hot blast temperature, not take BGA circuit board to try to blow. Why a maintenance staff feel

BGA welding too difficult, mostly unable to grasp the "heat gun" hot blast parameters, relying on the

subjective judgment or "experience" to high demand, high precision of BGA welding components, from

the Angle of the practical and scientific point of view, very loosely, natural and successful probability is low.

Overtemperature welding operation, although very fast, but with two questions:

1.BGA solder ball and PCB solder alloy ingredients become brittle, hard and formed by generated due to high

temperature oxidation of loose grain structure, PCB when installed the tin oxide ball bearing is easy to break,

bad welding.

2.Overtemperature makes local overheating deformation "tender" of the multilayer wiring board, serious when

blister stratification and scrap. At the same time, the present considerable WeiXiuZhe using "heat gun" because

there is no special BGA wind to blow BGA welding tsui, simply use the "heat gun" original wards off, because

the hot air range is very large, often is the BGA beside the SMD components are heated together, caused the

BGA welding is good, but its surrounding not heat-resistant components (such as tantalum electrolytic capacitor,

ceramic components, etc.) is burned, it is possible to use BGA special wind tsui safety to avoid the occurrence of

this problem. Too big of wind pressure on the BGA chip that is equivalent to external pressure to the chip,

because of BGA chip, light and thin, has the potential to tin ball inside even, unthreatening. Therefore, in the

welding process of BGA, scientifically set set the right temperature, wind, time four parameters, the welding area

is especially important.