Lead free bridge chip graphics

Lead free bridge chip graphics

1. For lead-free motherboards, remove after first into the oven at 100 degrees Celsius to bake,

time is generally 2 to 3 hours (this is the shortest time, factory general BGA to more than 10 hours)

of course into the motherboard electric water to use hot water to wash ultrasonic, dust corrosion of

some debris shock out.

2. Why going to bake the motherboard. The reason is that have long-term customers do not have

books the, suddenly take out starting point does not shine, weather, environment will cause the

motherboard or wet, this time you direct access to the motherboard into the BGA rework station,

directly heated from bridge, temperatures up to 250 to 270, local heating, and other places do not

heat, plus the bridge piece somewhat humidity, easy to cause the deformation of the motherboard,

so even if the BGA well is not stable.

3. Lead the bridge pieces generally, we have used 280 degrees take, tweezers to wait, see Xizhu shiny

struck lightly with tweezers, active use tweezers to pick up, in general can successfully take down,

pads on the motherboard directly to wipe solder paste help then iron gently scraping flat welding

(do not use suction tin wire to drag, easy to absorb tin wire sticking to pad in the iron to heating easy

to solder together off) and then apply solder paste, pay attention to smear evenly. Not too much to

melt beads.

4. bridge chip suction tin wire leveling alcohol wiped clean, set the beads (Wu Qian), should pay

attention to is, I use air gun wind 3 to 4, between 4 to 5 and then the first temperature, from the

right corner blowing, blowing to rotate the upper right corner of the air gun, the bridge piece is

4 to the distance 5 cm, when you see the shiny beads returned to solder joints, then continue to

rotate a blow to the upper left corner, the rotation of the amplitude can be large (not circles) and

then blow down to the lower right corner, then the beads easily melts into the solder joint on the

other hand, of course, is tweezers must see, must use the tweezers to separate them to stick together

in the ball, or post up (the bridge will be very troublesome beads blowing bulging or burst).

5. Successfully blowing up the bridge after if not ideal, cold bridge until after the meeting point

of solder paste (note not completely cooled down, but also a little temperature), in a uniform heating,

Xizhu homing to the solder joint is good, aligned position it into the motherboard to BGA... Of course

if a bridge piece by too close to with tinfoil other bridge piece cover or scrapped the CPU into the

bridge. The following infrared heating can also with foil to block, motherboards with fixation and

good without fixation with other things pressure can not be firmly shaking.