Spring-loaded, removable test fixture for circuit board testers
A circuit board tester that uses an axial translation to bring a unit under test (UUT) into physical and electric contact with a series of electrical probes. The element on the tester that comes into contact with the UUT, on the side opposite the probes, is both spring-loaded and removable. For a first configuration in which a UUT has a heat sink, an internal heat sink snaps into the top of the tester. When the UUT is tested, the heat sink on the UUT contacts the internal heat sink and depresses it slightly into the top, under the influence of a spring-loaded support. For a second configuration in which the UUT has no heat sink, a block snaps into the top of the tester, and is spring-loaded through a series of receptacles to a module that contacts the UUT during operation.
1. A heat sinking test jet for use in a circuit tester housed within an airtight enclosure, the circuit tester having a top surface with a portion of the top having a recessed receiving area therein said recessed area extending into said top surface, a bed for a circuit board under test, the test jet intended to contact at least one component on a circuit board on the bed the test jet comprising:
a) a mounting element sized to be releasably received within said recessed area and extending generally orthogonally away from said top surface in order to contact at least one component on said circuit board when under test;
b) a contact surface attached to said mounting element and capable of contacting a component on said circuit board under test; and
c) length adjustable linkage on said test jet capable of altering the distance between said mounting element and said contact surface so that, said mounting element intimately engages said component irrespective of the height of said component.
2. The test jet of claim 1 wherein said linkage includes at least one shaft connecting said mounting element and said contact surface and a bias element configured to provide a bias force against said mounting element, thereby insuring intimate contact between said mounting element and said circuit board under test.
3. The test jet of claim 2 wherein said adjustable linkage includes a shaft extending from through said top surface to a point external to said circuit tester and a heat radiator affixed to said shaft and likewise external to said circuit tester and wherein said shaft has a first end in contact with said mounting element and a second end connected to said heat radiator.
4. The test jet of claim 3 wherein said shaft includes a seal with said top surface for maintaining a vacuum between said top surface and said shaft.
5. The test jet of claim 1 wherein said linkage includes at least one element which telescopes to varying lengths.
6. The test jet of claim 1 wherein said mounting element engages said recessed receiving area in said top in a snap fit engagement.
7. The test jet of claim 6 wherein said snap fit engagement includes detents which maintain said recessed receiving area and mounting element in biased engagement when in place.
8. The test jet of claim 7 wherein said detents are ball detents extending outwardly from said mount and wherein said recessed receiving area includes notches to receive said detents.
9. The test jet of claim 6 wherein said snap fit engagement includes notches on said recessed receiving area and wherein said recessed receiving area engages surfaces of said mount and is locked into place by turning of said mount relative to said recessed receiving area.
10. The test jet of claim 1 , wherein said adjustable length linkage includes a spring bias element which is capable of contracting in length when said circuit board under test is engaged by said test jet.
11. The test jet of claim 1 wherein said contact surface includes a sensor for measuring temperature of a component on the circuit board under test.
12. The test jet of claim 1 wherein said contact surface includes an electrical probe for making measurements of electrical contacts on said circuit board under test.
13. The test jet of claim 1 wherein of the element includes a radiating heat sink outside of the enclosure.