JPH0669294A - Test probe device for integrated circuits - Google Patents

Abstract

(57) [Abstract] [Purpose] When the integrated circuit device is tested in the state of a wafer, the connection body of the test probe device for connecting the terminal to the test circuit is manufactured in a fine pattern using semiconductor manufacturing technology and connected. Improves uniformity of resistance and prolongs pot life. A probe base 11 having a wiring conductor 11a connected to a test circuit 40, an elastic body 12 fixed to the probe base 11, a flexible sheet 13a covering the surface thereof, a thin film conductor 11b and a contact 13c.
A connection body 13 for carrying the substrate, an operation means 20 for operating the base 11 toward the wafer 1, and a contact detection means 30 for detecting the contact start point of the contact 13c with the terminal 3 of the integrated circuit device 2. The operating means is provided after the detection signal Sd is issued from the contact detecting means 30 when the test probe 10 is operated toward the wafer 1.
The integrated circuit device 2 is tested while the probe 20 is operated by the predetermined small operation amount on the 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test probe for connecting terminals to a test circuit when testing an integrated circuit device in a wafer state.

[0002]

2. Description of the Related Art It is important to improve the yield in the manufacturing of integrated circuit devices, but it is actually difficult to achieve 100% yield. Therefore, it is necessary to carry out tests at the stage when the wafer process is completed. It is customary to determine whether the device is good or bad and, after the chips are isolated from the wafer, reject defective products. It is of course necessary to connect each integrated circuit device to the test circuit in the test in the state of the wafer, and for this connection, the integrated circuit device in the wafer is bumped by using the test probe targeted by the present invention. Connect to the test circuit sequentially through terminals such as electrodes and connection pads.

Although this test probe is functionally just a connecting jig, each integrated circuit device has tens to hundreds of square terminals or tens to hundreds of terminals with a small diameter of 100 to several hundreds μm. Since they are arranged at a narrow pitch, a fine mechanical structure and high connection reliability are required, and a long life is required so that a large number of wafers each with several hundred or more integrated circuit devices can be continuously tested. To be done. As a test probe capable of satisfying such a requirement, a probe in which a large number of needles each having a sharp tip are arranged side by side on a wiring board or the like has been conventionally used.

In this conventional test probe, a needle is made of a highly elastic material, such as tungsten, which is unlikely to be permanently deformed, and is formed into a tapered shape with its tip bent downward to form a thick base portion of a probe substrate such as a wiring board. Is firmly fixed in the horizontal direction, and the needle is flexed by slightly pushing down the base with its tip in contact with the terminal of the integrated circuit device, and the necessary contact pressure is held by the reaction force. In order to stably and uniformly maintain the connection resistance of such needles to the terminals of the integrated circuit device at the lowest possible value necessary for the test, the spring reaction force with respect to the deflection amount of many needles is made uniform, and the tip thereof is plated with gold or the like. Apply to reduce contact resistance as much as possible.

[0005]

The needle-type test probe described above has many achievements in the past and is almost satisfactory in terms of stability of connection resistance and long life, but it is expensive because it takes a lot of time to manufacture. In addition, there is a problem that the number of terminals increases and the array pitch becomes narrower with the progress of higher integration of integrated circuit devices, and it becomes very difficult to downsize the test probe accordingly.

The cause of this is that the tip of the needle is thin, but the base of the needle needs to be thicker by several orders of magnitude than the radius of curvature of the tip, so that even if the tip can be arranged according to the arrangement pitch of the terminals on the integrated circuit device side. There is a difficulty in arranging the base.
Of course, it is possible to arrange the bases in a plurality of rows such as a staggered pattern, but it is difficult to make the spring reaction forces uniform because the needles have different lengths. For this reason, when the terminal arrangement of the integrated circuit device becomes about 80 μm or less, it becomes very difficult to manufacture a test probe suitable for it, and in such a case, the test is divided into two despite the low utilization rate of expensive test equipment. It is the current situation that we have no choice but to do it.

In order to solve this problem, an attempt has been made to manufacture the connection part of the test probe as well as the integrated circuit device to be tested by utilizing the semiconductor manufacturing technique. It is easy to make a fine structure, but there are still many problems in the support structure of this connection part in the probe and the pressing operation to the terminal of the integrated circuit device, and it is difficult to guarantee the uniformity of connection resistance and the long life of the probe. In the worst case, the risk of damaging the wafer during the test cannot be ruled out. In view of such circumstances, an object of the present invention is to improve the uniformity of connection resistance and the operational reliability of a test probe having a connection portion manufactured by a semiconductor manufacturing technique.

[0008]

In a test probe device for an integrated circuit according to the present invention, there is provided a base body having wiring conductors connected to the test circuit, an elastic body fixed to the base body so as to project from the base surface, and an elastic body surface. A thin sheet conductor is lined up and carried on a flexible sheet that covers the connector, and a contactor corresponding to a terminal of an integrated circuit device is provided at an end portion on the elastic body and is connected to a connecting body which is connected to a wiring conductor of a substrate, respectively. An operating means for operating the substrate toward the wafer so as to bring the child into contact with the terminal and a contact detecting means for detecting contact of the terminal of the contact from the conduction state between the contacts are provided. The above-mentioned object is achieved by performing a test in a state where the substrate is operated by a predetermined operation amount after the contact is detected by the contact detection means during the operation toward the wafer.

For the elastic body in the above construction, it is preferable to use rubber having a high hardness so as not to cause permanent deformation during long-term use, and this is formed into a hill shape having a flat top surface and is formed on the top surface. It is preferable to provide a contact for the connector. As the flexible sheet for the connection body, a sheet of insulating polyimide resin or the like having a thickness of several tens to several hundreds of μm is used, and this sheet is bonded to the elastic body surface or a base body around the elastic body, preferably under tension. Is good. As the thin film conductor to be carried on this sheet, it is preferable to use a metal film by a vacuum deposition method or a sputtering method, particularly a gold thin film having a thickness of 2 to several μm. Gold or platinum is also suitable for the contact, and it is preferable to grow it by electrolytic plating to form a contact. The height is about 10 μm or more, and the size varies depending on the case, but it is 20-30
It is preferable that the angle is μm square or diameter.

It suffices for the contact detection means to detect that the contactor has come into contact with a terminal of the integrated circuit device and that the contactors have been conducted to each other through, for example, a resistor. Therefore, it is preferable to detect that the short circuit has been made, and therefore it is preferable to provide each integrated circuit device with, for example, two ground terminals or power supply terminals. A dedicated circuit may be provided as the contact detecting means, but the function can be easily incorporated in the test circuit. It is advantageous to use a step motor as the operation means of the test probe, and to set the operation amount after detecting the contact between the contact and the terminal by the number of pulses given to it, which usually results in an extremely small value of 200 to several hundreds of μm. Can accurately control a small operation amount. This operation amount is preferably set so that the pressure per contact is about several g in order to prevent the integrated circuit device from being destroyed and the probe from being damaged by excessive pressure.

[0011]

The present invention has a structure in which a thin film conductor is carried on a sheet and a contact is provided on the sheet so that it can be easily miniaturized by utilizing semiconductor manufacturing technology, and an elastic body is used to generate a uniform pressure. In addition to applying to the contactor, contact detection means is provided to detect the contact between the contactor and the terminal, and thereafter, the test probe is operated by a predetermined operation amount to provide an optimum contact pressure to the contactor to make the connection resistance uniform. And prolongs the life of the probe by preventing excessive pressure on the contact.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a test equipment of an integrated circuit device showing a test probe according to the present invention together with related wafers, test circuits and the like. FIG. 2 is an enlarged view of the main part of the test probe, FIG. 2 (a) is a plan view of the central portion of the connection body, and FIG. 2 (b) is a cross-sectional view near the periphery of the connection body of the test probe. Although the contact detection means 30 of FIG. 1 is shown as a dedicated circuit for easy understanding, its function can be easily incorporated in the test circuit 40.

First, an outline of the test equipment shown in FIG. 1 will be described. A wafer 1 is schematically shown in the center of the figure, and in order to sequentially test each integrated circuit device 2 built in a large number, a terminal 3 which is a bump electrode in the figure is tested via a test probe 10. Connected to 40. The test probe 10 is attached to the lower surface of the stage 23 whose position is operated by the operation means 20 in the z direction which is the vertical direction in the drawing. The stage 24 on which the wafer 1 is loaded for the test is the operating means 21.
22 indicates the x direction, which is the left-right direction, and the y direction, which is the front-back direction.
Respectively, the integrated circuit devices 2 in the wafer 1 to be tested are sequentially switched. Operation means
20 receives an operation command Sz from a computer 50 dedicated to this test facility and operates the stage 23 in response to the operation command Sz.
Reference numerals 21 and 22 operate the stage 24 in response to operation commands Sx and Sy from the computer, respectively.

The test circuit 40 is conventional in the test probe 10
A test voltage or current is applied to the integrated circuit device 2 via the circuit, and the output voltage or current is received to perform a predetermined test. The computer 50 operates the above-mentioned operating means 20 to 22 and inputs from the attached keyboard 51 to the integrated circuit device 2
The test contents are instructed to the test circuit 40 according to the designation of the type, and the quality of each integrated circuit device 2 is judged based on the test result. In addition, in the present invention, the contact detection means 30 is provided and connected to the test probe 10, and the integrated circuit device of the test probe 10 is operated every time the computer 50 gives an operation command Sz to the operation means 20 to operate the stage 23 downward. The start time of the contact state with 2 is detected, and the detection signal Sd indicating that is notified to the computer 50.

A test probe 10 shown in cross section in FIG.
In the present invention, is composed of a base 11, an elastic body 12, and a connecting body 13. The base 11 is a slightly thicker printed circuit board or wiring board attached to the stage 23, and the test circuit 40
And a large number of wiring conductors 11a respectively connected to. The elastic body 12 is a rubber or the like fixed to the lower surface of the base 11 so as to project therefrom, and is made of a material having a high hardness so as not to be too soft and to be permanently deformed during long-term use. It is preferable to form a hill-shaped cross section in which the top surface and the lower surface in the figure are flat as shown in the figure.

The connecting body 13 has a flexible sheet 13a on which a number of thin film conductors 13b are carried in a pattern as shown in FIG. 2 (a), and the thin film conductors 13b are provided at the end portions on the flat lower surface of the elastic body 12. The contactor 13c corresponding to the terminal 3 on the integrated circuit device 2 side is provided in a protruding manner. For the sheet 13a, for example, a polyimide resin film having a thickness of several tens to 100 μm and having high flexibility is used.
The thin film conductor 13b is formed by depositing a thin film of metal such as gold on the thin film conductor 13b to a film thickness of 2 to several .mu.m by a sputtering method or a vacuum evaporation method and photoetching it into a pattern having a narrow width of 20 to 30 .mu.m. . The contact 13c is preferably a small bump electrode made of a contact metal such as gold or platinum grown by electrolytic plating, the height is 10 μm or more, and the size is a thin film conductor 13b.
20 to 30 μm square or diameter which is about the same as the width.
The accuracy of the height of the contact 13c can be controlled to 2 to 3 μm or less.

FIG. 2 (b) shows the base body 11 and the elastic body of the connection body 13.
An example of how to fix and connect to 12 is shown. Sheet 13 of connector 13
It is preferable that a is firmly fixed to the elastic body 12 so as to cover it, and in the example shown in the figure, it is fixed to the surface of the elastic body 12 and the lower surface of the insulating plate 11b of the base 11 around the elastic body 12 with an adhesive 14. It is desirable that this bonding be performed with a slight tension applied to the sheet 13a. It is preferable that a thin film conductor 13b is provided not only on the lower surface of the sheet 13a but also on the upper surface of the sheet 13a as shown in the drawing, and the thin film conductor 13b is connected to the wiring conductor 11a of the base 11 through the conductive adhesive 15. Further, in the example shown in the drawing, a terminal conductor 11c is provided on the upper surface of the peripheral portion of the insulating plate 11b on the side of the base 11 as well, and is connected to the wiring conductor 11a on the lower surface through the through hole 11d.
Is connected to the test circuit 40.

In the test probe 10 having such a structure, the connecting body 13 includes a flexible sheet 13a, a thin film conductor 13b and a contactor 13.
Since it has a structure of supporting c, it has no spring biasing force,
The contact pressure of c to the terminal 2 is applied by the reaction force caused by the slight deformation of the elastic body 12. The contact pressure is preferably about several g per each contact 13c in order to prevent the destruction of the wafer 1 and the damage of the test probe 10, and the deformation amount of the elastic body 12 at this time is 200 to several hundreds μm, although it depends on the elastic force. 100 in some cases
It is as small as ~ 200 μm. As described above, when the deformation amount is small, the deformation reaction force applied to each contact 13c by the elastic body 12 is substantially equal, and the height of the contact 13c can be controlled with high accuracy as described above. Contactor 13c by 10
The contact pressure with respect to the terminal 3 can be made more uniform than before.

In the test facility of FIG. 1 having the above-mentioned configuration,
The test probe 10 according to the type of the integrated circuit device 2 is attached to the stage 23, and the operating means 21 and 22 are used to select the integrated circuit device 2 to be tested in the wafer 1 loaded on the stage 24. The stage 23 is lowered to connect the integrated circuit device 2 to the test circuit 40 via the test probe 10. In the present invention, the contact starting point of the contact 13c with the terminal 3 is set to the contact detecting means 30 before the connection is established. Let it be detected. In the illustrated example, the contact detection means 30 includes a photocoupler 31 and a low-voltage power supply 32 for detecting that the pair of contacts 13c of the test probe 10 are short-circuited by the integrated circuit device 2 in order to increase the sensitivity. It consists of a resistor 33. In addition, on the integrated circuit device 2 side, a terminal 2 corresponding to the above-mentioned specific pair of contacts 13c, for example, a ground terminal or a power supply terminal is provided in duplicate.

After the detection signal Sd is emitted from the contact detection means 30, the present invention conducts a test with a predetermined amount of operation being performed on the substrate 11 of the test probe 10 with reference to the contact start point indicated by the detection signal Sd. . Since the operation amount at this time is a minute amount of several hundreds μm or less as described above, in this embodiment, a step motor is used as the operation means 20 and an operation command Sz including a predetermined number of pulses is given to this to precisely control the operation amount. To do. As a result, the integrated circuit device 2 can be connected to the test circuit 40 with a uniform and sufficiently low connection resistance while the optimum contact pressure is applied to the contact 13c with good reproducibility, and the test can be performed accurately.

[0021]

According to the test probe device of the present invention, a base body having a wiring conductor connected to a test circuit, an elastic body fixed to the base body so as to project from the base body surface, and a flexible sheet covering the elastic body surface are provided. The thin film conductors are arranged side by side, and the terminals on the elastic body are provided with contacts corresponding to the terminals of the integrated circuit device, and the connection body connected to the wiring conductor of the base body and the base body on the wafer so that the contacts come into contact with the terminals. An operating means for operating the contact and a contact detecting means for detecting a contact starting point of the contactor and the terminal are provided, and the contact starting point is detected by the contact detecting means when the probe base is operated by the operating means. The following effects can be obtained by conducting a test after operating the substrate by a predetermined operation amount.

(A) By adopting a structure in which a thin film conductor formed by photo-etching a connecting body is carried on a flexible sheet and a contact is grown by electrolytic plating, a semiconductor manufacturing technique is used to miniaturize a pattern and It is possible to easily and inexpensively manufacture a probe suitable for testing a highly integrated integrated circuit device in which individual terminals are arranged at a narrow pitch. (b) By utilizing the deformation reaction force of the elastic body to apply more uniform contact pressure to the contact than before, the terminals of the integrated circuit device are connected to the test circuit with a uniform connection resistance to improve the accuracy of the test. can do.

(C) Connection is provided by providing contact detection means to detect the contact start point with the terminal of the contact, and then operating the test probe by the required amount of operation to provide the contact with the optimum contact pressure. It is possible to improve the reproducibility of resistance as compared with the conventional one and prevent the excessive pressure applied to the contactor to prolong the life of the probe.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a test facility of an integrated circuit device showing a test probe device of the present invention together with a wafer, a test circuit, and the like.

2 is an enlarged view of the main part of the test probe device of FIG. 1, where FIG. 2 (a) is a plan view of the central portion of the connection body, and FIG. 2 (b) is a cross-section near the periphery of the connection body of the test probe. It is a figure.

[Explanation of symbols]

 1 wafer 2 integrated circuit device 3 terminal of integrated circuit device 10 test probe 11 base of test probe 11a wiring conductor 12 elastic body 13 connection body 13a flexible sheet 13b thin film conductor 13c contactor 20 operating means or step motor 30 contact detection circuit 40 Test Circuit 50 Test Facility Calculator

Claims (3)

[Claims] 1. A probe for connecting a terminal of each integrated circuit device to a test circuit for testing the integrated circuit device built in a wafer, comprising a plurality of wiring conductors connected to the test circuit. A wiring board-shaped base body, an elastic body fixed to the base body so as to project from the base body surface, and thin film conductors are lined up and carried on a flexible sheet covering the elastic body surface. An integrated circuit device is provided at an end of the thin film conductor on the elastic body. A connecting body having a contact for the terminal of and a thin film conductor connected to the wiring conductor of the base, and an operating means for operating the base toward the wafer so that the contact of the connecting body contacts the terminal of the integrated circuit device, A contact detecting means for detecting contact with a terminal of the contact from a conductive state between at least one pair of contact, and the contact is detected by the contact detecting means while operating the probe base toward the wafer by the operating means. It Test probe apparatus for an integrated circuit, characterized in that to carry out the test in a state of operating the substrate by a predetermined operation amount after. 2. The test probe device for an integrated circuit according to claim 1, wherein rubber is used for the elastic body. 3. The apparatus according to claim 1, wherein the operating means is a step motor, and the number of pulses that gives the step motor an operation amount with respect to the substrate after the contact between the contact and the terminal is detected by the contact detecting means. A test probe device for an integrated circuit, characterized in that it is set by.