JP2544186B2 - Probe device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a probe device.

(Prior Art) In general, a probe card is used as a connection body which is installed in a probe apparatus and electrically connects an electrode pad of an IC chip formed on a device under test, such as a semiconductor wafer, and a tester.

Recently, due to technological innovation in the semiconductor manufacturing process, high integration of IC chips has advanced, and the number of circuits forming the IC chip for a given area has increased. Further, the number of electrode pads per chip also increases with the number of circuits. That is, the lead wires and electrode pads that make up the circuit are miniaturized. or,
The distance between each lead wire and each electrode pad is also narrow. When inspecting such IC chips, probe cards are also required to be compatible. In order to meet such a demand, as a means for increasing the number of probe terminals, which are the contacts of the probe card, within a certain area, for example, the one in which the probe terminals are mounted almost perpendicular to the object to be inspected is disclosed in 11741, JP-A-60-189949, JP-A-61-154137, JP-A-61-20
No. 5870, Jikken Sho 59-12615, Jikkou Sho 62-36139, Jikkou Sho 62-44365, etc. Further, the one in which a conductive pattern and a probe terminal are formed on an insulating substrate by a photolithography technique to cope with the increase in the probe terminal is disclosed in, for example, Japanese Patent Publication Nos. 58-11739, 59-18864, and 61.
-14659, JP-A-58-162045, JP-A-58-197835
No. 59, JP-A-59-9934, JP-A-59-9935, JP-A-59-
19342, JP-A-59-141239, JP-A-59-144142,
JP-A-59-148345, JP-A-60-198838, JP-A-61-
2338, JP-A-61-154044, and the like.

(Problems to be Solved by the Invention) However, in the above-described substrate in which the probe terminal is vertically fixed, the tip of the probe terminal is shock-contacted with the surface of the electrode pad, which is the object to be inspected, at the time of contact inspection to the electrode pad. In addition, there is a problem that the probe terminal is damaged due to distortion due to the addition of the overdrive, and the probe terminal becomes brittle and lacks in durability.

Further, in the probe card formed by the photolithography technique, a process including heating is performed in forming the conductive pattern and the probe terminal on the insulator during the photolithography process. During this heating, the conductive pattern and probe terminals are in an expanded state. When the temperature returns to room temperature after these steps, the conductive wire and the probe terminal shrink. Due to this history, when the conductive pattern and the probe terminal are contracted from the expanded state, stress is applied to the insulator forming the conductive pattern and the probe terminal. Then, distortion or the like such as warpage occurs in this insulator, and it is difficult to manufacture a probe card that requires high accuracy.

The present invention has been made to solve the above problems, and it is possible to accurately arrange a conductive wire having a probe terminal row corresponding to an electrode row of an ultra-miniaturized DUT in an insulator, and An object of the present invention is to provide a probe device capable of highly accurately producing a probe card without warping of an insulator even when a conductive wire of a probe terminal is formed on the insulator surface, and by doing accurate inspection. I am trying.

(Means for Solving the Problem) The probe device of the present invention has a probe terminal array arranged corresponding to the electrode array of the device under test, and conductive wires connected to the probe terminal array are insulated on the surface, respectively. The object to be inspected comprises a probe card having a formed insulator and a pattern film formed on the back surface of the insulator and applying a thermal stress corresponding to the thermal stress exerted on the insulator by forming the conductive wire. The probe terminal array is electrically contacted with the electrode array of (1) to perform an inspection.

(Effects and Effects) According to the present invention, the conductive lines connected to the probe terminal array are formed as conductive line patterns on the surface of the insulator so as to be insulated from each other. Conductive wires having a probe terminal array can be accurately arranged on the insulator, and a pattern coating is formed on the back surface of the insulator to apply the thermal stress corresponding to the thermal stress exerted on the insulator by forming the conductive wires. Therefore, even if the conductive wire of the probe terminal is formed on the surface of the insulator, it is possible to manufacture a probe card with no warp in the insulator with high accuracy, and to provide a probe device capable of performing accurate inspection. You can

(Embodiment) Next, an embodiment in which the probe device of the present invention is applied to a wafer prober for inspecting a semiconductor wafer will be described with reference to the drawings.

A tester (not shown) for inspecting the electrical characteristics of an object to be inspected, for example, an array pattern of a large number of electrode pads (3) of an IC chip (2) regularly formed on a semiconductor wafer (1).
A probe card (4) for making electrical contact with is provided on the wafer prober.

The probe card (4), as shown in FIG.
Mainly, a support (5) that does not elastically deform, and a crystal Z-plane plate (hereinafter abbreviated as a crystal plate) that compensates for thermal strain.
(6) and a conductive pattern (7) formed on the crystal plate (6).

The crystal plate (6) is elastically deformable, and a large number of conductive patterns (7) also functioning as probe terminal portions (8) serving as contact terminals are formed on the crystal plate (6). The arrangement of the conductive patterns (7) corresponds to the electrode pads (3) of the IC chip (2) on one end side, that is, the probe terminal portion (8) side, in an insulated state as shown in FIG. . Also,
As shown in FIG. 2, the conductive pattern (7) has the following structure.
First, a metal, such as a chromium (Cr) layer (9), which is easily compatible with quartz as a wetting material, is sputtered by, for example, 500 Å. Next, a metal such as a gold (Au) layer (10) which is easily compatible with Cr is sputtered by, for example, 500 Å, and a base film is formed by both of them. Then, a conductive layer (11) serving as a conduction path for an electrical inspection signal is formed on the base film by electrolytic plating, for example, about 5 μm. The material of the conductive layer (11) is preferably a good electric conductor, such as gold, silver or copper. Here, if the conductive pattern (7) having such a structure is formed only on one surface of the crystal plate (6), the crystal plate (6) is deformed, for example, warped due to the stress of the conductive pattern. That is, since a process including heating is performed when the conductive pattern is formed, when the conductive pattern returns from the heated state to the room temperature state, the conductive pattern contracts, and stress is applied from one surface of the quartz plate (6) to be deformed. Here, in order to prevent this deformation, deformation prevention measures are taken. For example, as shown in FIG. 2, conductive patterns (7) are formed on both sides of the quartz plate (6) in the same arrangement. Then, the stress due to the formation of the conductive pattern (7) is applied to the same position on both surfaces of the crystal plate (6) to the same extent.
As a result, the stress applied to the crystal plate (6) interferes with each other from both sides, and the crystal plate (6) is not deformed such as warped. Further, since stress is applied to the crystal plate (6) from both sides, the repulsive force of the crystal plate (6) becomes strong.

And as above. A crystal plate (6) having conductive patterns (7) formed on both sides is provided with a probe terminal portion (8) on one end side of the conductive pattern (7). This probe terminal portion (8) has a quartz plate (6) for each conductive pattern (7) at a position corresponding to the electrode pad (3) pattern of the IC chip (2) to be inspected, as shown in FIG. Is formed so that the tip of the needle has a needle-shaped acute angle. For example, it is formed by a predetermined etching technique. In this way, the contact portion that comes into contact with the inspection object is configured.

Next, the support part which supports this contact part is demonstrated.

This support portion is composed of a support body (5) made of an insulating material that does not elastically deform, for example, a ceramic. As shown in FIG. 5, an opening (12) slightly larger than the shape of the electrode pad (3) pattern formed on the IC chip (2) is provided at a predetermined position of the support (5). ing. Further, an insulating projection (13) is attached to the support (5) by, for example, a resin adhesive so as to surround the opening (12) at a predetermined interval. The conductive wire (14) is wired in an insulated state from the outer periphery of the protrusion (13) to the connector position where it is connected to a tester (not shown) for inspecting the object to be inspected. Along with the opening (12) of the support (5), one to a plurality of the contact portions are provided. In this installation, as shown in FIG. 5, the crystal plate (6) and the support (5) are bonded with a resin, for example, an acrylic resin adhesive. At this time, the crystal plate (6) is not adhered to the entire surface, but is brought into contact with the projection (13) provided on the support (5) at a predetermined position of the crystal plate (6) to open the opening (12). ) Position, the probe terminal portion (8) is bonded so as to form a free end. That is, each probe terminal portion (8) is installed so as to correspond to the arrangement pattern of the electrode pads (3) of the IC chip (2) to be inspected. Here, when the contact portion is formed separately corresponding to each side of the IC chip (2), the above-described bonding method is applied to each side of the opening (12) of the support (5). Therefore, the corresponding contact portions may be bonded. After this adhesion, the conductive pattern (7) formed on the crystal plate (6) and the conductive wire (14) of the support (5) are electrically connected by a wire bonding method, for example, with a gold wire (15). Connect as a state. In this way, the probe card (4) is constructed.

The contact portion of the probe card (4) described above can be manufactured, for example, as follows.

First, for example, a crystal plate (6) having a mirror-finished thickness of, for example, about 100 μm is set at a predetermined position, with the thickness direction being the Z direction of the crystal axis.

Next, a chromium layer (9) is formed on both sides of the crystal plate (6) simultaneously by sputtering a metal, such as chromium, which is easily compatible with the crystal as a base film, to a thickness of, for example, about 500Å.

Further, as a base film, a metal such as gold, which is easily compatible with chromium, is simultaneously formed on the chromium layers (9) on both sides to a thickness of, for example, 500.
Å Sputter to form a gold layer (10).

Then, after electroplating gold on the gold layer (10) to obtain a predetermined gold film thickness, a resist is applied on both surfaces, and the resist and unnecessary portions of the resist, that is, the conductive pattern (7) and the probe, are exposed and developed. The resist at the positions other than where the terminal portion (8) is formed is removed.

Then, for example, wet etching is performed to remove the exposed gold layer (10) and the chromium layer (9) corresponding to the position of the gold layer (10). As a result, base films for forming desired conductive patterns (7) and probe terminal portions (8) are formed on the quartz plate (6) in an insulating state.

Then, after removing the resist formed as a mask on the base film, the resist is applied to the exposed part of the base film and the crystal plate (6), that is, one surface. Then, by exposing and developing, only the probe terminal portion (8),
The resist in the portion where the base film is not formed is removed.

In this state, the crystal plate (5) exposed at the probe terminal portion (8) is wet-etched with a corrosive liquid such as ammonium fluoride. At this time, the quartz plate (6) other than the base film and the probe terminal portion (8) is not etched using the resist as a mask.

 Next, all the unnecessary resist is removed.

After that, a metal having a good electrical conductivity, for example, gold, silver, or copper is formed on the base film by electrolytic plating to a thickness of, for example, about 5 μm. As a result, the conductive pattern (7) is formed on the base film.
And the probe terminal part (8) is formed.

When silver or copper is used as the metal for the conductive pattern (7) and the probe terminal portion (8), an anti-oxidation metal such as a gold layer is electroplated in order to prevent oxidation of the silver or copper layer. The thickness may be, for example, about 2 μm.

The probe card (4) having the contact portion formed as described above is placed on a wafer prober which is an inspection device for the wafer (1) to inspect the IC chip (2) formed on the wafer (1). To do. Next, the operation and action in the inspection will be described.

First, the object to be inspected, for example, the wafer (1) is set at a position facing the probe card (4). Where the wafer (1)
And the probe card (4) are moved relatively close to each other, for example, the wafer (1) is lifted to move the probe card (4).
Formed on the wafer's probe terminal (8) and wafer (1)
The electrode pad (3) of the chip (2) is brought into contact. Then, the wafer (1) is further raised, that is, overdrive is applied by a predetermined amount. By this overdrive, the probe terminal portion (8) and the electrode pad (3) of the IC chip (2) are accurately connected. At this time, for protection, the elastic force of the crystal plate (6) on which the probe terminal portion (8) is installed pushes the probe terminal portion (8) slightly upward. At this time, even if the pushing force applied to the crystal plate (6) by overdrive is small, the crystal plate (6)
Conductive line patterns (7) and (7) are formed on both surfaces of
Since the elastic force of the crystal plate (6) is reinforced by the two conductive wire patterns (7) and (7), the repulsive force of the crystal plate (6) is strong and the probe terminal portion (8) necessary for electrical inspection. It is possible to obtain the contact pressure between the electrode pad (3) and the electrode pad (3), and thus it is possible to shorten the time spent for overdrive and shorten the inspection time. Also, in such a connection state, IC
The test signal output from the tester is applied to the input electrode of the chip (2) from the probe terminal (8), and the electrical signal generated at the output electrode of the IC chip (2) is applied from the other probe terminal (8). Output to the tester and inspect the IC chip (2). After this inspection is completed, the wafer (1) is lowered by a predetermined amount. As a result, the probe terminal portion (8) and the electrode pad (3) are brought into non-contact with each other. At this time, the probe terminal portion (8) returns to a predetermined original state by the reaction force of the crystal plate (6).

As described above, according to this embodiment, the probe terminal portion (8) row arranged corresponding to the electrode pad (3) row of the wafer (1) and the probe terminal portion (8) row are connected. Quartz crystal plate (6) having conductive line patterns (7) formed on the front surface thereof, respectively, and a crystal plate (6) formed on the back surface of the crystal plate (6) and formed by the conductive line patterns (7). A probe card (4) having a conductive wire pattern (7) as a pattern coating for applying a thermal stress corresponding to that on the electrode pad (3) row of the wafer (1). ) Since the inspection is performed by electrically contacting the rows, the conductive line pattern (7) having the row of probe terminals (8) corresponding to the row of electrodes of the ultra-miniaturized DUT is provided with the crystal plate (6). Can be arranged with high precision, and Even if the conductive wire pattern (7) of the probe terminal portion (8) is formed on the surface of the crystal plate (6), the probe card (4) having no warp on the crystal plate (6) can be manufactured with high precision, As a result, the wafer (1) can be accurately inspected.

Conductive wire patterns (7), (7) are formed on both sides of the crystal plate (6), and both conductive wire patterns (7),
Since the elastic force of the crystal plate (6) is reinforced by (7), the repulsive force of the crystal plate (6) is strong even if the pushing force applied to the crystal plate (6) by overdrive is small.
The contact pressure between the probe terminal portion (8) and the electrode pad (3) necessary for the electrical inspection can be obtained, and the time spent for overdriving can be shortened to shorten the inspection time.

The present invention is not limited to the above embodiment,
Even if the object to be inspected is not a semiconductor wafer, the same effect can be obtained by inspecting an LCD substrate used in an image display device such as a liquid crystal television.

Further, in the above-mentioned embodiment, the stress applied to the crystal plate due to the formation of the conductive pattern causes deformation such as warpage of the crystal plate, and in order to prevent this deformation, the same conductive pattern is formed on both sides of the crystal plate. However, the present invention is not limited to this, and any pattern coating can be applied to the back surface of the crystal plate so as to correspond to the thermal stress applied to the crystal plate from the conductive pattern used for inspection. Further, the insulator forming the conductive pattern is not limited to the quartz plate, and may be any one that can be elastically deformed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a probe card installed in a probe device for explaining one embodiment of the probe device of the present invention,
FIG. 2 is a sectional view of the contact portion of the probe card shown in FIG. 1, and FIG.
1 is a plan view of the contact portion of the probe card shown in FIG. 1, FIG. 4 is an explanatory view of the tip of the contact portion shown in FIG. 3, and FIG. 5 is a plan view of the probe card shown in FIG. 4 ... Probe card, 5 ... Support 6 ... Crystal Z-plane plate, 7 ... Conductive pattern 8 ... Probe terminal

Claims (1)

(57) [Claims] 1. A probe terminal row arranged corresponding to an electrode row of an object to be inspected, an insulator formed by electrically insulating conductive wires connected to the probe terminal row on the surface, and an insulator of this insulator. A probe card having a pattern coating formed on the back surface and applying a thermal stress corresponding to the thermal stress exerted on the insulator by forming the conductive wire is provided, and the probe terminal array is electrically connected to the power array of the device under test. A probe device, which is brought into contact with a probe for inspection.