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7-2 Site Preparation 7 Compressed Air and Vacuum Requirements Introduction Both compressed (or pr essurized) air and vacuum are used in the testhead. Compressed air is used primarily to secure the test fixture to the tes…
7-2 Site Preparation
7 Compressed Air and Vacuum Requirements
Introduction
Both compressed (or pressurized) air and vacuum are used in the testhead. Compressed air is used
primarily to secure the test fixture to the testhead. Vacuum is used primarily to actuate the test fixture:
that is, to make contact between the board under test and the probes in the fixture. Compressed air
is sometimes also used for air-assisted, solenoid-actuated valves used to switch the vacuum, and for
air-actuated test fixtures.
The site preparation requirements for compressed air and vacuum are different depending on the type
of testhead you are preparing the site for. This chapter describes those requirements.
For more about compressed air and vacuum principles and terminology, see the short Compressed
Air and Vacuum Primer on page 7-7.
Compressed Air and Vacuum Requirements 7
Site Preparation 7-3
Compressed Air Requirements
The i3070 uses compressed air to pressurize air cylinders that actuate fixture pull-down towers.
Pull-down towers are used to pull and hold a fixture down onto the testhead, enabling contact
between the pins on the fixture and the spring-loaded interface pins in the testhead.
• Connecting Air to the Testhead
• Compressed Air Specifications
• Air Quality
Connecting Air to the Testhead
Install compressed air lines using rigid line to a point near the testhead. An air cutoff valve is
recommended for situations when the air line must be disconnected.
When the system is installed, connect the air to the testhead with a flexible line that has a Hansen
Series 3000 Push-tite 1/4-inch female coupling or equivalent. The testhead air input connector is
shown in Figure 7-30.
Figure 7-30 Compressed air connection to the testhead