Elevated
temperature test capability is available on Series 5000
Handling Systems. The Model 5080 or 5040 Handlers include
an enclosed heated tray which is used to preheat a quantity
of devices prior to being tested in an heated test site.
The devices "soak" in the heated chamber for a user-programmed
length of time.
Track
Types
The Soak Chamber is available in either eight track (5080) or four
track styles (5040). In the 5080, the tracks are stationary and
are emptied into the handler test site by means of a shuttle mechanism
in the chamber. The 5040 has four tracks which move and are indexed
over the test site without using a shuttle. The choice of tracks
will depend on several factors including dimensions of the part,
weight of the part, test times, etc. In any case, each track holds
up to twenty inches of devices for soaking. When the chamber is
full to capacity it will heat, for example, 400 20-pin PLCC's to
any specified temperature between ambient and 155 degrees centigrade.
Temperature
Control
Exatron enjoys an excellent reputation for their temperature controlling
capability. The guaranteed accuracy is +/-2 degrees Centigrade
everywhere in the Soak chamber and +/-1 degree Centigrade in the
Test Site. Exceptional temperature control is maintained by constantly
monitoring 12 points in the Chamber and 4 points within the Test
Site. The Chamber is sealed to eliminate temperature variation
conditions. Each of the sixteen zones is independently monitored
by a thermocouple, and heated independently. Each zone has independent
calibration offsets and out-of-temperature alarms. Individual control
allows extremely accurate temperature and compensates for the "chimney" effect
from lower zones.
Unlike most temperature systems,
Exatron heaters are pulsed on and
off. This prevents over- and under-shoot
of temperature targets. Typically,
overshoot in the chamber is held
to less than five degrees centigrade
when initially warming up.
