Mobile phone welding operation

Mobile phone welding operation

Maintenance department of the process card hot air gun set temperature control table below SMT element

(IC, resistance, capacitance, etc.)
330+20 operating time 3S BGA (CPU, FLASH, power, power amplifier)
300+20 operation time 6S within the shield cover (easy heat dissipation components)
350+20 operation time MIC 6S, LED, sensitivity (temperature sensitive components)
260+20 operation time 6S

According to Yu supervisor to explain, understand the need to pay attention to the problem:
1, hot air gun muzzle need to be taken at the top of the components;
2, remove the components (such as resistors, capacitors etc.) need to stick in the welding flux blowing back

to the specified location. When the components are removed, the need to vertical, can not sway around,

otherwise it will cause the components in the vicinity of the.
3, hot air gun for about 3 cm distance components, except Headset, t-card seat seat etc..
4, the characteristics of some of the basic components are as follows: inductance L on the motherboard is

usually white capacitance C on the motherboard is usually gray r resistance on the motherboard is usually

black hexapod components for the IC, IC effects of different location different tripod components triode

tube zero resistance (features: black with the word "mouth") a major role for near the power supply,

components play a role in protecting the CPU, which is equivalent to the fuse.

5, hot air guns specifications, and now used by Dingshi maintenance department are three: the first quick

p990a small hot air gun for blowing welding small resistors, capacitors, inductors and other components;

the second ATTEN AT805 hot air rifle (air gun) for blowing welding IC, CPU and other components;

the three STEINL (type 3483) (230V~2300W) (big hot air gun, the hot air gun features:

constant temperature) for blowing welding t-card holder of SIM card connector, with hard rubber,

shielding cover and other components.
6, maintenance station by the use of tools, fixtures, electrostatic ring, multimeter, tweezers, dust-free cloth,

plate washer water, solder paste, planting tin, Gua Xidao, toothbrush, absorbent paper, high temperature

glue, a blade, a gasket (by iron or wood, an outside firm on high temperature glue for blowing welding,

will blow the suface of welding on the above, to protect working bench role), test fixture maintenance

station by the use of equipment: electric iron, hot air guns, regulated power supply, computer

Blowing the lid solder mask problems that need attention points:
1, even with a hot air gun to blow around the shield cover.
2. When taking cover, can not shake hands, otherwise it will be inside and outside components knocked nearby.
3, the need to shield cover components cool before welding near the welding shield cover.
4, prior to welding, now the shield cover into the specified location, blowing welding.
5, with a hot air gun shield cover in the far distance (3 cm) slowly close.
6, when the shield cover blown welding will go, we need to hold the shield cover with tweezers, without moving

the shield cover.

  Blow welding SIM card, you need to pay attention to problems when T deck:
1, you must use big mouth hot air gun, the wind gun thermostat, easy to cause deformation of SIM card of hard

plastic, which scrapped.
2, from the wind and elements muzzle about 4CM, easy too.
3, when the blow welding, always pay attention to changes in element Yingjiao found hard plastic deformation of

hot air gun away immediately.