WO2007066643A1

WO2007066643A1 - Probe pin, probe card, and probe device

Info

Publication number: WO2007066643A1
Application number: PCT/JP2006/324232
Authority: WO
Inventors: Kenichi Kataoka; Ka Toh; Toshihiro Itoh
Original assignee: Tokyo Electron Limited; The University Of Tokyo
Priority date: 2005-12-06
Filing date: 2006-12-05
Publication date: 2007-06-14
Also published as: TW200736617A; TWI314213B; JP5048942B2; JP2007155553A

Abstract

[PROBLEMS] To increase the life of a probe pin. [MEANS FOR SOLVING THE PROBLEMS] The contact part of the probe pin is formed of a tin smaller in strength than the electrode of a wafer (W). Thus, since the probe pin is broken when it is separated from the electrode, a part of the electrode can be prevented from adhering to the probe pin. A container for reserving a molten tin is installed on a probe device. The container is three-dimensionally movable by a moving mechanism so that the probe pin can be immersed into the molten tin in the container. Consequently, it is possible to supply the tin onto the surface of the broken probe pin.

Description

Specification

Probe pins, probe cards and probe devices

Technical field

[0001] The present invention relates to a probe pin, a probe card, and a probe device for testing the electrical characteristics of a test object by contacting the test object.

Background technology

[0002] For example, to inspect the electrical characteristics of electronic circuits such as ICs and LSIs formed on semiconductor wafers, probe pins provided on a probe device are pressed against and brought into contact with the electrodes of the electronic circuits on the wafer side. It is done by.

[0003] Since the above-mentioned probe pin requires cutting off the oxide film on the electrode surface, the probe pin has traditionally been made of strong materials such as tungsten or nickel to withstand multiple inspections. A strong metal is used (see Patent Document 1).

Patent document 1: Japanese Patent Application Publication No. 2005-106497

Disclosure of invention

Problems that the invention seeks to solve

[0004] When the contact part of the probe pin is pulled away from the electrode on the wafer side while applying force, a part of the electrode on the wafer side is peeled off and the contact part of the probe pin is pulled away from the electrode on the wafer side. It may stick. For this reason, there was a concern that by performing multiple tests, deposits would accumulate on the contact portion of the probe pin, resulting in poor electrical contact between the probe pin and the electrode. For this reason, it was necessary to replace the probe pins in a short period of time and remove the deposits with a brush, which shortened the lifespan of the probe pins.

By the way, in recent years, in order to reduce the contact pressure between the probe pin and the electrode, a voltage is applied to the probe pin that is in contact with the electrode, and the oxide film on the surface of the electrode is dielectrically broken down using the fritting phenomenon. , techniques have been proposed for establishing electrical continuity between probe pins and electrodes. In this case, it has been confirmed that a relatively strong adhesive force is generated between the probe pin and the electrode due to welding, and when the probe pin and the electrode are separated, part of the electrode is damaged due to the tensile stress at that time. It is easy to break and become damaged, and to stick to the contact part of the probe pin. Therefore, When using the fritting technique, deposits tend to accumulate on the probe pin, resulting in poor contact between the probe pin and the electrode.

[0006] The present invention has been made in view of the above-mentioned problems, and is intended to prevent part of the contact portion of the object to be inspected, such as a wafer, from peeling off and adhering to the contact portion of the probe pin. That purpose.

Means to solve problems

[0007] To achieve the above object, the present invention provides a probe pin for testing the electrical characteristics of a test object by contacting the test object, the probe pin having at least one contact portion that comes into contact with the test object. The surface is characterized by being made of a material that is weaker than the contact part on the side of the object to be inspected. Note that a material with low strength refers to a material that breaks under small stress.

[0008] According to the present invention, since the surface of the contact portion of the probe pin is weaker than the contact portion on the side of the test object, when the bonded probe pin and the test object are separated, the contact portion of the probe pin The sides break and peel off. In this case, no deposits are deposited on the probe pin, and a new surface of the probe pin is always exposed, so that stable contact with the object to be inspected can be maintained even if the probe pin is used many times. As a result, for example, there is no need for probe pin tallying work, and the life of the probe pin can be extended.

[0009] The surface of the contact part is formed of the material with low strength, and the inner part of the surface of the contact part is made of a material with stronger strength than the contact part on the side of the object to be inspected! It's okay.

[0010] The material of the contact portion having low strength may be tin or an alloy containing tin.

[0011] The probe pin may be used to establish electrical continuity with a contact portion on the test object side by utilizing a fritting phenomenon.

[0012] According to another aspect of the present invention, a probe card including the above-mentioned probe pins is provided.

[0013] The present invention according to another aspect is a probe device equipped with a probe pin for testing the electrical characteristics of a test object by contacting the test object, the test object side being in contact with the probe pin. The strength is weaker than the contact part of the probe pin, which is in contact with the container that stores the molten material and the test object, so that it can be immersed in the melt in the container. a moving mechanism for moving the container, and at least the surface of the contact portion of the probe pin is formed of a material whose strength is weaker than that of the contact portion on the side of the object to be inspected. be a sign.

[0014] According to the present invention, since the surface of the contact portion of the probe pin is weaker than the contact portion on the side of the test object, when the bonded probe pin and the test object are separated, the contact portion of the probe pin The sides break and peel off. Therefore, no deposits are deposited on the probe pin, and since a new surface of the probe pin is exposed, stable contact with the object to be inspected can be maintained even if the probe pin is used many times. This eliminates the need for tallying the probe pin, for example, and extends the life of the probe pin. Furthermore, since the contact part of the probe pin can be immersed in the molten material in the container, the peeled off part of the contact part can be replenished and recovered. This allows the life of the probe pin to be further extended. Furthermore, since the surface shape of the contact portion of the probe pin is stabilized, the contact with the object to be inspected becomes even more stable.

[0015] The probe device may include a heating member that heats the container.

[0016] The probe device may have a fritting function that utilizes a fritting phenomenon to electrically connect the test object and the probe pin.

Effect of the invention

[0017] According to the present invention, there is no need to clean the probe pin, and the life of the probe pin can be extended. In addition, since stable contact points with low electrical resistance can be formed, the accuracy of testing electrical characteristics can be stabilized.

Brief description of the drawing

[0018] FIG. 1 is a side view schematically showing the configuration of a probe device.

FIG. 2 is an explanatory diagram of a vertical cross section showing the configuration of a probe pin attachment part.

FIG. 3 is an explanatory diagram showing the functions of the circuit of the printed wiring board.

[Figure 4] An explanatory diagram of a vertical cross section of a container and a hot plate.

FIG. 5 is an explanatory diagram showing a state in which two probe pins are in contact with an electrode.

[FIG. 6] (a) is an explanatory diagram of a longitudinal section showing a state in which a probe pin is in contact with an electrode. (b) is an explanatory diagram of a longitudinal section showing a state in which the probe pin is separated by electrode force. FIG. 7 is an explanatory diagram of a vertical cross section of a contact portion whose surface is coated with tin.

[Figure 8] A graph showing the results of an experiment to measure the lifespan of probe pins.

Explanation of symbols

[0019] 1 Probe device

10 probe pin

31 Contact part

P electrode

W wafer

BEST MODE FOR CARRYING OUT THE INVENTION

[0020] Preferred embodiments of the present invention will be described below. FIG. 1 is an explanatory diagram showing an outline of the configuration of a probe device 1 according to the present embodiment.

[0021] For example, the probe device 1 includes a probe card 2, a mounting table 3 on which a wafer W as an object to be inspected is placed, and a movement mechanism 4 that moves the mounting table 3.

[0022] The probe card 2 includes, for example, a contactor 11 supporting a plurality of probe pins 10 on its lower surface that contact electrodes of a wafer W, and a printed wiring board that sends and receives electrical signals to and from the probe pins 10 through the body of the contactor 11. It has 12. Contactor 11 and printed wiring board

12 is formed, for example, into a substantially disk shape, and the printed wiring board 12 is arranged on the upper surface side of the contactor 11 so as to be able to conduct electricity with the contactor 11.

[0023] The probe pin 10 is connected to a connection terminal 20 formed on the lower surface of the main body of the contactor 11, for example. For example, as shown in FIG. 2, the probe pin 10 is composed of a linear beam portion 30 and a contact portion 31 protruding perpendicularly to the tip of the beam portion 30, and has a substantially L-shape. . The rear end side of the beam portion 30 is joined to the connection terminal 20, and the contact portion 31 protrudes downward at the tip of the beam portion 30. This contact portion 31 contacts the electrode P serving as the contact portion of the wafer W.

[0024] The probe pin 10 is, for example, integrally molded, and the whole is made of a conductive material, such as tin, whose strength is weaker than that of the electrode P of the wafer W, such as aluminum. The material of the probe pin 10 is selected to have a tensile strength smaller than that of the electrode P by lOMPa or more, for example.

[0025] Inside the main body of contactor 11, there are probe pins 10 on the bottom side and a printed circuit on the top side. Connection wiring (not shown) for electrically connecting to the circuit board 12 is formed.

[0026] For example, as shown in FIG. 3, the probe pin 10 is connected to a test circuit 40 that transmits and receives electrical signals for testing electrical characteristics, and a voltage is applied to the probe pin 10 of two single threads in order to cause a fritting phenomenon. The test circuit 40 is connected to the flitting circuit 41 that applies the voltage via a switching circuit 42 that switches between the test circuit 40 and the flitting circuit 41. Here, the fritting phenomenon means that when the potential gradient applied to the surface of electrode P reaches approximately 10 ⁵ to L0 ⁶ V/cm, the oxide film on the surface of electrode P undergoes dielectric breakdown and current flows through the oxide film. This refers to the phenomenon in which the flow of water occurs. The fritting circuit 41 applies a predetermined voltage between a pair of probe pins 10 that are in contact with the electrode P of the wafer W, and increases the potential gradient between the two probe pins 10. At the two contact points between the two probe pins 10 and the electrode P, the oxide film on the surface of the electrode P can be dielectrically broken down at the same time to establish electrical continuity between the electrode P and the probe pin 10. can. Note that in this embodiment, the flitting function is realized by the flitting circuit 41.

[0027] As shown in FIG. 1, the moving mechanism 4 includes, for example, a horizontal support base 50 that supports the mounting base 3 with downward force, an elevating drive unit 51 such as a cylinder that raises and lowers the horizontal support base 50, and an elevating drive unit 51. It consists of an X-Y stage 52 that moves in two horizontal directions: the X direction and the Y direction. Thereby, the wafer W placed on the mounting table 3 can be moved three-dimensionally, and the probe pins 10 can be brought into contact with desired electrodes P of the wafer W.

[0028] For example, next to the mounting table 3 on the horizontal support table 50, a hot plate 61 serving as a heating member is provided, which has a built-in heater 60 that generates heat by power supply. A container 62 for storing molten tin A, which is the constituent material of the probe pin 10, is provided on the hot plate 61, as shown in FIG. The molten tin A in the container 62 can be maintained in a molten state by the heat of the hot plate 61. In addition, since the container 62 is placed on the same horizontal support 50 as the mounting table 3, it can be moved three-dimensionally by the moving mechanism 4, and the contact portion 31 of the probe pin 10 is connected to the molten tin A in the container 62. Can be immersed in water. Thereby, tin can be attached to the contact portion 31 of the probe pin 10.

[0029]Next, the operation of the probe device 1 described above will be explained together with the wafer W inspection process.

First, the wafer W is placed on the mounting table 3. Next, the moving mechanism 4 moves the wafer W three-dimensionally, and as shown in Figure 5, two probe pins 10 are attached to each electrode P of the wafer W. is contacted. At this time, the electrode P and the probe pin 10 are brought into contact with an extremely low contact pressure. Next, a voltage is applied between the two probe pins 10 of each electrode P using the fritting circuit 41. By gradually increasing this voltage and increasing the potential gradient between the probe pins 10, a fritting phenomenon is caused and the oxide film on the surface of the electrode P is dielectrically broken down (fritting process). In this way, the electrical resistance between the probe pin 10 and the electrode P is reduced, and the probe pin 10 and the electrode P are electrically connected.

[0030] After all electrodes P and probe pins 10 are electrically connected, the switching circuit 42 switches from the fritting circuit 41 to the test circuit 40. Next, using the test circuit 40, electrical signals are sent from each probe pin 10 to the electrode P, and the electrical characteristics of the electronic elements on the wafer W are tested.

[0031] When the electrical characteristic test is completed, the moving mechanism 4 lowers the wafer W, and the probe pin 10 is released from the electrode P. When the above-mentioned fritting process is performed, the adhesive force between the probe pin 10 and the electrode P becomes large. This is considered to be because a high current temporarily flows through the narrow contact area between the probe pin 10 and the electrode P during the fritting process, and the probe pin 10 and the electrode P are welded together. Then, when the probe pin 10 is pulled away from the electrode P, tensile stress acts on the probe pin 10 and the electrode P. Since the strength of the probe pin 10 is weaker than that of the electrode P, the strength of the probe pin 10 is changed from the state where the probe pin 10 and the electrode P are in contact as shown in Fig. 6 (a) to the state shown in Fig. 6 (b). When the electrode P is pulled away from the probe pin 10, a part of the surface of the contact portion 31 of the probe pin 10 breaks off, peels off, and adheres to the electrode P.

[0032] After that, Ueno and W are carried out from the probe device 1. After the above inspection process is repeated a predetermined number of times, the container 62 is moved horizontally to below the probe pin 10 by the moving mechanism 4 as required, and then raised to move the container 62 to the probe as shown in FIG. Contact portion 31 of pin 10 is immersed in molten tin A in container 62. In this way, the missing portion of the contact portion 31 of the probe pin 10 is replenished with tin, and the surface shape of the probe pin 10 is restored.

[0033]According to the above embodiment, since the probe pin 10 is made of tin, which is weaker in strength than the electrode P of the wafer W, when the probe pin 10 and the electrode P are separated, the probe pin 10 The sides break and peel off. As a result, part of the electrode P adheres to the probe pin 10 side and accumulates. Since a new surface of the probe pin 10 that does not accumulate is exposed, contact between the probe pin 10 and the electrode P can be maintained even if the probe pin 10 is used many times. Therefore, the life of the probe pin 10 can be extended. Furthermore, since no deposits are deposited on the probe pin 10, the contact between the probe pin 10 and the electrode P can be stabilized.

[0034] In the embodiments described above, since electrical continuity between the probe pin 10 and the electrode P is achieved by utilizing the fritting phenomenon, welding may occur between the probe pin 10 and the electrode P. Conceivable. Therefore, a relatively large force is required to pull them apart. therefore

, the probe pin 10 used in the fritting process is made of a material weaker than the electrode P, and promoting breakage on the probe pin 10 side prevents part of the electrode P from adhering to the probe pin 10. It is very effective in doing so.

[0035] In the above embodiment, since the probe device 1 is provided with the container 62 in which molten tin A is stored, the probe pin 10 is immersed in the molten tin A in the container 62, and the defective portion of the probe pin 10 is You can replenish the amount. As a result, the shape of the probe pin 10 is maintained, so that the life of the probe pin 10 can be further extended.

[0036] Since the container 62 is placed on the hot plate 61, the molten tin A in the container 62 can be maintained in a molten state.

[0037] In the embodiments described above, the entire probe pin 10 is made of tin, but only the surface of the contact portion 31 of the probe pin 10 is made of tin, which is weaker in strength than the electrode P; The inner surface of the electrode 31 may be made of a material stronger than the electrode P, such as tungsten or the like. For example, as shown in FIG. 7, the main body 10a of the probe pin 10 is made of nickel (Ni), and the surface 10b of the contact portion 31 of the probe pin 10 is coated with tin. The surface 10b is coated with tin to a thickness of, for example, about 10 ^mm to 0.01 mm. According to this example, since the main body 10a of the probe pin 10 is made of a strong material, the strength of the probe pin 10 as a whole is ensured, and it will not be deformed due to contact with the electrode P, for example. Furthermore, since only the surface of the contact portion 31 is coated with tin, the breakage during separation occurs only on the surface of the contact portion 31, so that no large chunks of tin will adhere to the electrode P side. Note that the entire body 10a of the probe pin 10 (beam portion 30 and contact portion 31) is made of the above-mentioned material with high strength, but only the contact portion 31 is It is made of strong and strong material.

[0038] The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to these examples. It is clear that those skilled in the art can come up with various changes and modifications within the scope of the idea stated in the claims, and these naturally fall within the technical scope of the present invention. It is understood that it belongs to For example, in the above embodiment, tin is used as a material having a lower strength than the electrode P, but other materials such as an alloy containing tin or solder may also be used. In the embodiments described above, the present invention is applied to the probe pins used when the flitting process is performed. The present invention can also be applied when the object to be inspected is a substrate other than the wafer W, such as an FPD (flat panel display) or a mask reticle for a photomask.

Example

[0039] An experiment was conducted on the life of the probe pin when tin, which is weaker in strength than the electrode P, was used as the material of the probe pin 10, and when tungsten was used as the material of the probe pin. Note that the material of the electrode P at this time is aluminum. In Figure 8, the horizontal axis shows the number of measurements, and the vertical axis shows the contact resistance. If the contact resistance is large, the probe pin will become unusable and the life of the probe pin will be shortened. As shown in Figure 8, the contact resistance of the probe pin 10 made of tin (Sn) remains stable at around 1 Ω even after 300 measurements. For probe pins using tungsten (W), after about 50 measurements, there are measurement points where the contact resistance values vary widely, and the contact resistance values are also large. From this experimental result, it can be confirmed that by using tin as the material of the probe pin 10, the life of the probe pin becomes longer. Furthermore, since the contact resistance is stable at a low value when tin is used for the probe pin, it can be confirmed that the contact between the probe pin and the electrode is stable.

Industrial applicability

[0040] The present invention is useful in extending the life of probe pins.

Claims

The scope of the claims

[1] A probe pin for testing the electrical characteristics of a test object by contacting the test object,

At least the surface of the contact portion that comes into contact with the object to be inspected is made of a material that is weaker in strength than the contact portion on the side of the object to be inspected.

[2] The probe pin according to claim 1,

The surface of the contact portion is formed of the material with low strength, and the inner portion of the surface of the contact portion is formed of a material with stronger strength than the contact portion on the side of the object to be inspected.

[3] The probe pin according to claim 1,

The material of the contact portion having low strength is tin or an alloy containing tin.

[4] The probe pin according to claim 1,

It is used to create electrical continuity with the contact part on the test object side by utilizing the fritting phenomenon.

[5] A probe card for testing the electrical characteristics of a test object,

The probe pin has a probe pin that tests the electrical characteristics of the test object by contacting the test object, and the probe pin has at least a surface of a contact portion that comes into contact with the test object with a stronger strength than a contact portion on the test object side. It is made of weak material.

[6] A probe device equipped with a probe pin for testing the electrical characteristics of a test object by contacting the test object,

a container for storing a molten material having a lower strength than the contact part on the test object side that contacts the probe pin;

a moving mechanism for moving the container so that a contact portion of a probe pin that contacts the object to be inspected can be immersed in the molten material in the container;

At least the surface of the contact portion of the probe pin is made of a material that is weaker in strength than the contact portion on the side of the object to be inspected.

[7] In the probe device according to claim 6,

It has a heating member that heats the container.

[8] In the probe device according to claim 6, It has a fritting function that uses the fritting phenomenon to create electrical continuity between the test object and the probe pin.