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Mobile phone BGA welding
Mobile phone BGA welding
With the volume of the mobile phone is more and more small, it is more and more high degree of
integration of the internal and phones are now used almost all of ball grid array packaging module
and that is what we say normally BGA. This module is welded on the motherboard in the form of
patch.. For maintenance personnel, skilled master hot air gun, as a compulsory course to repair
1. The degree of heat resistant BGA module and temperature of the heat gun control techniques, BGA
encapsulation of the entire bottom module used to connected to the circuit board.Not by welding tube feet,
but the use of solder ball to welding.Module to reduce the volume, mobile phones are relatively narrow the
volume, but also the packaging form of the module determines the easy to the characteristics of virtual
welding, mobile phone manufacturers in order to reinforce the module, often using glue method.This
increases the maintenance difficulty.To deal with this kind of glue sealing module, we need hot air gun to
blow for a long time to remove the modules, often in the process of blowing welding, desoldering
temperature control is not good, the module down also damaged because of the temperature is too high.
So how to effectively regulate the temperature of the air pressure gun.To disconnect the module and not
damage!Told everyone several models commonly used in the heat temperature and welding of BGA module
should pay attention to matters.MOTOROLA V998 CPU, you must be very familiar with it, most of this kind of
module is encapsulated with glue.The heat degree is higher, the module of temperature of the air pressure
gun won't damage it is generally not more than 400 degrees, we can adjust the air pressure gun when the
desoldering temperature to 350-400 degrees, uniform on the surface of the heating, while waiting for the
CPU has a tin ball out, under the instructions of solder has dissolved, then you can move it gently with forceps,
and security.No more than the welding method of the module of the module also use nokia 8210/3310 series
of CPU, but the CPU encapsulation adhesive is different, you should pay attention to when the desoldering
sealant for the damage to the pins on the main board.Siemens 3508 audio module and a 1118 CPU.The two
modules are directly welded on the main board, the heat resistant level is very poor, but they generally difficult
to withstand temperatures above 350 degrees, especially 1118 CPU. When welding generally not more than
300 degrees.We can welding to put a piece of broken on the good CPU CPU. Thus reduce damage caused
direct blow welding module.Blow welding time may be longer, but the success rate will be higher.
2. The motherboard above a bit after the remedies.Maintenance of friends at first, in the open encapsulated
with plastic module, will certainly encounter a bit on the main board.Like a lot of solder joints is not over,
we can do it in the attachment point method to repair, the repair this bit of failure, I use green oil temmoku
companies as a curing agent for fixed connection.
Motherboard off point there are basically two kinds, one kind is can see pins on the motherboard, such better
handle some wire welding on the pin directly, keep a proper line into a circular placing it on a bit position,
another kind is a solder hole type, this kind of difficult to deal with some, use a knife to dig out the following
pin first, then made the size of the solder wire circle, on the location of the bit.Plus a solder ball, heat with air
pressure gun.So that the circle and pins together.Next is to use green oil curing, besmear is on processing
good bonding pad, with a magnifying glass on the condenser under the sun for a few seconds, the curing
degree is better than a day heat with heat gun.Motherboard off solder joints, we even better, with lines after
clean.In fixed or insulation need coated with green oil, get outside, use a magnifying glass as the sun
concentrated green oil.A few seconds curing.
3. The bonding pad on a bit of welding method.Welding plate, after a bit before welding plate is cleaned,
the strikes a little way on the module of rosin, then on the bonding pad, be careful not to put too is, mean
to put a little bit crooked, but don't crooked too much, then heated, modules, such as the following tin ball
melts, the module will be automatically reset to the welding plate, welding should pay attention to don't
swing module.In addition, when planting tin, if the solder paste is too thin, can take out a little on a napkin,
the flux to the absorption of paper, the solder paste is good!