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BGA rework station before the operation will need to know

BGA rework station before the operation will need to know


1. lead-free preheating temperature heating rate control in general 1.2~5 DEG C / S (s), the preheating

temperature is generally not more than 160 DEG C, heat preservation zone temperature control in the

160~190 DEG C, reflow peak temperature control in general 235~245 DEG C and the temperature

maintain time in 10 to 45 seconds, from heating up to the time of the peak temperature should be

maintained at about a minute and a half to two minutes.


2.Lead solder melting point is 183 degrees, and lead-free is 217 degrees. That is to say when the

temperature reaches 183 degrees, lead paste begins to melt, the melting point of the solder ball,

owing to their chemical properties will be higher than the solder paste.


3.Machine knowledge:
1, the application is broad: the upper part of the hot air lower dark infrared.Three,

2, temperature area models: the lower part of the upper air of the lower hot air dark infrared.
3, and red appearance: infrared upper lower infrared dark, key points: different types of products

the heating mode of the utility model, using temperature program exist different settings.


4.Introduction of hot air:


Hot air heating is the use of air heat transfer principle, the use of high precision controllable high

quality heating control, adjustment of air volume, wind speed to achieve the purpose of uniform

controllable heating, welding, bga chip ontology for the reason of the heat transfer, the temperature

of the part to the bga chip beads is better than the hot air outlet by a certain temperature, when setting

temperature heating (due to different manufacturers of the machine temperature control of the definition

of temperature is different, the requirement of temperature have certain difference), will take the above

factors into consideration, we also want to know about the performance of solder ball, to distinguish

between temperature period set (specific setting methods please refer to the manufacturer's technical

guidance), the key is the highest temperature adjustment period, first of all, first set a value to test run the

bga rework stations heating, heating to note that in for a new board, don't know under the condition of

the temperature tolerance, to monitor the whole process of heating process, the temperature rises to above

200 degrees, when viewed from the side the degree of melting process of solder ball (can also be from the

bga patch beside a touch gently with forceps, if can patch a displacement, prove that the temperature has

been achieved requirements), in the bga chip solder ball all melt will be obviously observed bga chip to cave

in, this time we want to put the machine the temperature of the instrument or touch screen display and

record the machine running time, the melt temperature at this time plus 10 to 20 seconds, when you can get

an ideal temperature!


Conclusion: BGA, solder ball in achieving the highest temperature go n seconds of time to start to separate,

only need to the temperature curve of the highest temperature is set to the highest temperature constant

temperature 20 seconds. Other procedures please refer to manufacturer to provide the temperature curve

parameters. Under the general condition with welding lead the whole process control in 210 seconds,

lead-free control in 2.8 seconds. Time shoulds not be too long, too long to PCB and BGA are likely to

cause unnecessary damage.


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