2019-BTU-web-Vacuum-reflow-Dimock.pdf - 第13页

0 100 200 300 400 500 600 700 800 Hold time The time at the chosen vacuum le vel Hold times as short as 1 sec and long as a few minutes are possible. At 1 sec there is little time for void s to move to the surface T imes…

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Vacuum level
The amount of vacuum
0
100
200
300
400
500
600
700
800
Levels as low as 1 and high as 250 Torr
(and higher) are possible
Experienced significant void reduction
even at 250 Torr
0
100
200
300
400
500
600
700
800
Hold time
The time at the chosen vacuum level
Hold times as short as 1 sec
and long as a few minutes are possible.
At 1 sec there is little time for voids to
move to the surface
Times greater than 40 seconds have
been proven to not be needed
Equalization
Rate at which the chamber is
returned to atmospheric pressure
0
100
200
300
400
500
600
700
800
Currently no known limitations
Experiments done at ~ 85 Torr/sec