JPH04366767A - Test head - Google Patents

Abstract

PURPOSE:To enhance the quality of test signals transmitted between a test head and a DUT. CONSTITUTION:A test head, which transmits and receives test signals via a performance board 20 on which a device to be measured and inspected is mounted and via a contact pin 12, has a contact pin guide 30 so formed that a guide hole 31 provided in such a manner as broadening from the pad 24 side of the performance board 20 toward that side of the board 20 at which the contact pin 12 is inserted has its diameter on the pad 24 side made to almost coincide with the outside diameter of the contact pin 12. The contact pin 12 is guided in a proper direction by the broadening guide hole 31 and guided to the pad 24 so that the contact pin 12 is connected to the pad 24 with accuracy.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a device to be tested (
Regarding the test head of an LSI tester that transmits and receives test signals to the performance board on which a DUT (hereinafter abbreviated as DUT) is mounted, in more detail, the alignment of the pads of the performance board and the contact pins of the test head is improved. The present invention relates to a test head that performs accurate testing and improves the quality of test signals exchanged between the test head and a performance board.

0002

2. Description of the Related Art FIG. 5 is an exploded perspective view of a conventional test head. In the figure, 10 is a test head, 20 is a performance board, and the DUT is connected via a socket board 21.
22 is installed. 11 is a contact ring, and a plurality of contact pins 12 are provided radially from the center of the test head 10 toward the outer diameter direction. The contact pins 12 are connected to a pin electronics card in the test head 10 via a flexible cable (not shown), and transmit test signals from the pin electronics card via the performance board 20. DUT22
The measured signal from the DUT 22 is transmitted to the pin electronics card via the performance board 20.

Contact pin 12 and performance board
The connection between the test head 10 and the performance board 20 is made by pressing the contact pin 12 against a pad provided on the performance board 20 (see FIG. 2). Each of the manse boards 20 is provided with a positioning pin 13 and a positioning hole 23.

FIG. 6 is an equivalent circuit showing only the electrical system of FIG. 5. In the figure, parts having the same functions as those in FIG. 5 will be described with the same reference numerals. The same applies to drawings below. Reference numeral 14 denotes a pin electronics card which transmits and receives high frequency test signals to and from the DUT 22 via the contact ring 11 and the performance board 20. 24a
, b indicate the sense line pads and force line pads provided on the performance board 20 in terms of capacitance. In a mixed digital/analog tester, pads 24a and 24b for the sense line and force line are provided for each test pin, and are approximately 4 mm2 in size to absorb alignment errors with the contact pins 12. , and each has a capacitance of about 3 pF.

[0005]

[Problem to be Solved by the Invention] Such conventional test heads have a large alignment error between the contact pins and the pads on the performance board, so the pads on the performance board side must be made larger. There wasn't. Therefore, there has been a problem in that the quality of test signals exchanged between the test head and the DUT is degraded due to the capacitance of the pads.

The present invention has been made in view of these points, and by accurately aligning the contact pins and the pads of the performance board, the area of the pads can be made as small as possible, and the transmission system can be improved by using the pads. It is an object of the present invention to provide a test head that eliminates electrostatic capacitance generated in the test head and improves the quality of test signals exchanged between the test head and a performance board.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a test head that transmits and receives test signals via contact pins and a performance board on which a device under test to be measured is mounted. The diameter of the guide hole on the pad side, which is provided to widen from the pad side of the performance board toward the side into which the contact pin is inserted, is made to approximately match the outer diameter of the contact pin. has a contact pin guide formed;
The contact pin is guided in an appropriate direction by the guide hole that widens toward the end, leading to the pad, and the contact pin is accurately connected to the pad. Further, the guide hole is characterized in that at least the vicinity of the opening on the pad side is made of an insulating material.

[0008]

In the test head of the present invention, the contact pins are guided to the pads along the contact pin guide provided on the performance board and are accurately connected to the pads.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a main part of an embodiment of a test head according to the present invention, and FIG. 2 is a sectional view showing a unit of a pad, a guide hole, and a contact pin. In the figure, 30 is a contact guide made of an insulating material and has a substantially cylindrical shape.
Guide hole 3 for accurately guiding the contact pin 12 of the test head to the pad 24 on the performance board 20
1 is provided.

The contact guide 30 performs with the guide holes 31 accurately aligned with each pad 24.
It is fixedly attached to the mansboard 20 side. The guide hole 31 is inserted into the contact pin 12 from the pad 24 side.
The opening on the pad 24 side has a hole diameter that almost matches the outer diameter of the contact pin 12.

When the performance board 20 with the contact guide 30 attached is mounted on the test head 10, the contact pin 12 enters the guide hole 31 from the wider opening of the guide hole 31, It contracts in the direction of arrow D as it hits the inner wall of. Since the guide hole 31 has a larger radius R on the side where the contact pin 12 is inserted, even if the contact pin 12 is inserted with a deviation within a distance R from the center of the pad, it will not fit into the pad 24. can be guided accurately.

FIG. 3 is a sectional view showing one unit of a pad, a guide hole, and a contact pin in another embodiment. The contact guide 30 is made of a conductive member such as metal, and only the guide hole 31 is made of an insulating member such as plastic or ceramic. For this reason, performance
An insulating sheet 25 is provided between the manse boards 20 to maintain insulation.

The contact ring 30 is entirely grounded to reduce capacitive crosstalk (interference) between the contact pins 12. The contact guide 30 includes a pad 24 that comes into contact when the contact pin 12 is pressed against the performance board 20.
It is only necessary that the vicinity of the side opening be made of an insulating member; for example, a material made by molding a mixture of ceramic or plastic with a metal filler can also provide similar characteristics against crosstalk.

FIG. 4 is an equivalent circuit showing only the electrical system of the present invention. As can be seen by comparing with Figure 6,
Since the pad 24 can be formed small, the capacitance generated in the transmission system can be ignored. Therefore, the quality of test signals exchanged between the test head and the performance board can be easily improved.

[0015]

Effects of the Invention As explained above in detail, the test head of the present invention allows the contact guide to be used as a performance ball.
By providing the pads on the performance board, the positioning accuracy of the pads of the performance board and the contact pins is significantly improved, so the area of the pads can be reduced. For this reason, the capacitance of the pad can be reduced,
The quality of test signals exchanged between the test head and the DUT can be improved. In addition, the performance board is
Since the area of the pad is reduced, the wiring area can be expanded.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of main parts showing an embodiment of a test head of the present invention.

FIG. 2 is a sectional view showing one unit of a pad, a guide hole, and a contact pin.

FIG. 3 is a sectional view showing one unit of a pad, a guide hole, and a contact pin in another embodiment.

FIG. 4 is an equivalent circuit showing only the electrical system of the present invention.

FIG. 5 is an exploded perspective view of a conventional test head.

6 is an equivalent circuit showing only the electrical system of FIG. 5; FIG.

[Explanation of symbols]

12 Contact pin 20 Performance board 24 Pad 30 Contact guide 31 Guide hole

Claims (2)

[Claims] Claim 1: In a test head that transmits and receives test signals through contact pins and a performance board on which a device to be tested is mounted, the contact pins are inserted from the pad side of the performance board. A contact pin guide is provided in which the pad-side hole diameter of the guide hole is formed to widen toward the side and substantially match the outer diameter of the contact pin; The test head is characterized in that the contact pin is guided in a proper direction to the pad, and the contact pin is accurately connected to the pad. 2. The test head according to claim 1, wherein the guide hole is made of an insulating material at least near the opening on the pad side.