- Model NO.: T-870A
- Specification: 220V / 110V AC 50--60HZ
- HS Code: 85151100
- Trademark: Puhui
- Origin: Tai′an City, Shandong Province, China
The frist step:
According to PCB big and small, reconciliation PCB plate space and space between, the unsolderBGA have to face to face top red light, let facula cover CMOS chip.
Reconciliation light and sensor 's high in order to keep from CMOS chip to light about 20mm, the sensor's warm just touch CMOS chip or side so that keep warm exactly. Will be used syringes to inject liquid flux demolition welding at the bottom of the chip, Welding can also help prevent loss pad.
The second step:
The warm-up plate's warm up sensing head, put on the PCB 's weld plate hole or sheet copper, Not on the board are below the top Al stent, becuase affect warm.
The third step:
Enactment warm-up warm, generally the plumbum enactment100 degree, no plumbum enactment120degree. Turning on warm-up on-off, 3-5min, when reach warm-up, please according true intance, then turn on top light ASAP, reconciliation hot up light 's high reach 2/3, so that content hot up request. Dont rise temperate too quickly, Heating too fast to prevent a gas explosion caused by flux-the-stick, but also prevent the heating time is too long, resulting in at the bottom of components falling.
The fourth step:
Useing 936 iron and suck tin line clean weld plate after, smear a little liquid flux in order to spare wheel.
The fifth step:
Good-will plant the ball good or scraping the pulp-chip BGA, according to the requirements of the cleaned gently on the good pad. Turn on warm-up plate on-off, warm-up, Will be at the top heating sensor lights manually lowered gently to contact his next chip. To wait until after the preheating temperature (flux at this time has begun to restore infiltration pad pad oxide), quickly open the top of heating lamps, and other volatile flux after the collapse chip 10 Switch off the top and within seconds was preheating, and other board cooling to 100 degrees below, the board will be removed, put aside the cooling
The sixth step:
Welding good see the board has been cooling, with Xiban liquid and dry cleaning, electricity can be tested. If the test passed, to find out the reasons, then engage in a clear reason to prevent damage to several welding board.
But the general test for power, I think the following points, for reference purposes only
1. Pad clean up bad, empty weld,
2. Tin Pulp returning less than the temperature, empty weld,
3. Heating Flux not too fast to the volatile urgency, a gas explosion, causing chip shift, tin or tin-pulp precipitation Tin-tin-or short-circuit connections vacancy empty weld.
4. Welding Always End the board after cooling, such as cleaning, washing or dry cleaning is not after, the electricity board will burn.
They are personal expensive, no possible right, for reference purposes only and wrong, please you master advice. Good experience to share.