JP3458684B2 - Contact probe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact probe which is incorporated in a probe card or the like and makes an electrical test by contacting each terminal of a semiconductor IC chip, a liquid crystal device or the like.

[0002]

2. Description of the Related Art Generally, a contact probe equipped with a contact pin is used to make an electrical test by contacting each terminal of a semiconductor chip such as an IC chip or an LSI chip or an LCD (liquid crystal display). To be For example, in the contact probe 30 shown in FIGS. 5 and 6,
A film layer 32 made of a polyimide resin or the like is laminated on a ground 31 made of a metal layer such as Cu, and an Ni layer is formed on the film layer 32 via an adhesive layer 33 made of an adhesive agent.
The pattern wiring 34 made of a base alloy or the like is arranged and fixed. The tip ends of the pattern wirings 34 are arranged at a narrow pitch and protrude from the tip end of the film layer 32, and each of them constitutes a contact pin 3. This contact pin 3
A terminal of a semiconductor IC chip, a liquid crystal device, or the like is brought into contact with the needle tip of.

Such a contact probe 30 is shown in FIG.
Further, as shown in FIG. 8, a probe card (probe device) 36 is incorporated in the mechanical piece, and a terminal such as a semiconductor IC chip is brought into contact with the contact pin 3. That is, in the probe card 36 shown in FIGS. 7 and 8, the printed circuit board 3 having the central window portion 37a
A top clamp 38, for example, is attached on top of 7. Further, the base clamp 39 is fixed to the lower portion of the top clamp 38 with bolts 40 and the like, and the tip end side portion of the contact probe 30 is attached to the lower surface of the base clamp 39 with double-sided tape or the like. By pressing the base portion of the contact probe 30 with the substantially frame-shaped bottom clamp 41,
The tip side portion of the contact probe 30 is held in an inclined state, and the base portion is pressed against the lower surface of the printed circuit board 37 by the pressing rubber 42 of the bottom clamp 41. by this,
The rear end portion of the pattern wiring 34 of the contact probe 30 is pressed against the terminal on the lower surface of the printed circuit board 37 through the window portion 44 to be held in contact therewith. In such a state, the terminal 2 of the inspection object such as the semiconductor IC chip 1 is brought into contact with the contact pin 3 and an electrical test is performed.

By the way, for example, as shown in FIG. 9, as the terminal 2 of the semiconductor IC chip 1, gold Au or solder Pb is used.
Some include metals such as -Sn. On the other hand, the contact pin 3 of the contact probe 30 is
It is necessary to prevent the deterioration of the high frequency signal at the time of energizing for the test,
It is necessary to use a material with good conductivity. Ni-Mn alloy or the like which is usually used as the material of the contact pin 3 is
The hardness is high, but the electrical resistance is large, so that the transmission signal is easily deteriorated when energized to cause noise, which is not preferable. Therefore, as shown in FIG. 9, the contact pin 3 is made of Ni-M.
The inner layer 4 is formed using an n-alloy, and the surface thereof is coated with Au to form the coating layer 5. Then, when the contact pin 3 is brought into contact with the terminal 2 during the test, a signal is transmitted between the terminal 2 and the contact pin 3 through the coating layer 5 having good conductivity.

[0005]

By the way, when the electrical test of the semiconductor IC chip 1 and the like is repeatedly performed using the contact pin 3 as described above, the contact pin 3
A phenomenon occurs in which Au of the terminal 2 is attached to the tip of the (2) (this is referred to as the attachment portion 6) and gradually grows. Therefore, in the plurality of adjacent contact pins 3 and 3, the attached portions 6 and 6 attached and grown to the tip of each contact pin 3 are
As shown in, the problem of contacting each other and causing a short circuit occurs. Further, when a soft metal such as solder other than gold is used as the metal of the terminal 2, the same problem will occur.

In view of the above situation, the present invention provides a contact probe capable of preventing deterioration and transmitting a signal without the metal of the terminal adhering to the energizing contact portion of the contact pin. The purpose is to do.

[0007]

In view of the above-mentioned problems, as a result of intensive studies by the present inventors, it was found that it is very soft like Au and the like, easily plastically deformed, and very stable chemically. When a metal having the property that a surface film is difficult to form on the surface of the same metal, when a mutual contact occurs between the same metals, a new surface appears on the surface of the metal such as Au due to plastic deformation even with a low contact force, and the contact occurs at this new surface. It was found that a sticking phenomenon occurs because of being exposed. Therefore, on the contact surface of the same metal having good conductivity such as Au-Au, not only in the energized state, but also when not energized, the other metal tends to adhere to one side. The present invention is based on such knowledge.

The contact probe according to the present invention is a contact probe in which a plurality of pattern wirings are formed on a film, and each tip of these pattern wirings protrudes from the film to form a contact pin. The needle tip of the pin is characterized in that the inner layer made of a Ni-based alloy is covered with Au, Ag or Cu except for the contact portion for energization. When the current-carrying contact part of the contact pin is brought into contact with the terminal of the object to be inspected such as a semiconductor IC chip, the current-carrying contact part comes into contact with a dissimilar metal because the Ni-base alloy is exposed, and the Ni-base alloy has a hardness. Since the height is high, it is possible to prevent the metal of the terminal from adhering. Moreover, the contact pin is made of Au except for the contact portion for energization.
Since it is coated with a conductive metal such as, the conductivity is good, and since the skin effect can be used, signals can be transmitted without deterioration and high frequency compatibility is possible. Here, the conductive metal means a metal having good conductivity, softness, and easy plastic deformation, and includes, for example, Au, Ag, Cu and the like.

The contact probe according to the present invention is
In a contact probe in which a plurality of pattern wirings are formed on a film, and the tips of these pattern wirings project from the film to form contact pins, the needle tip of the contact pin is made of a Ni-based alloy. The inner layer is coated with a platinum group metal, and the surface of the platinum group metal is
It is characterized in that it is covered with Au, Ag or Cu except for the contact portion for energization. Since the Ni-based alloy is not exposed at the current-carrying contact portion, contact failure due to oxidation of this portion does not occur, and since the platinum group metal and the terminals are dissimilar metals and have high hardness, no adhesion phenomenon occurs. In addition, by contacting the terminal with the current-carrying contact portion made of a metal of the platinum group having high hardness, the adhesion phenomenon does not occur at the current-carrying contact portion, and inside the contact pin, a conductive metal such as Au is formed due to the skin effect. A signal will be transmitted through the coating layer.

The contact probe according to the present invention is
In a contact probe in which a plurality of pattern wirings are formed on a film, and the tips of these pattern wirings project from the film to form contact pins, the needle tip of the contact pin is made of a Ni-based alloy. The inner layer is characterized in that the energizing contact portion is coated with a platinum group metal and the other portions are coated with Au, Ag or Cu. By contacting the terminal with the current-carrying contact portion made of a platinum group metal having high hardness, no adhesion phenomenon occurs in the current-carrying contact portion, and inside the contact pin, a coating layer of a conductive metal such as Au due to a skin effect is formed. The signal will be transmitted.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a vertical cross section of a needle tip of a contact pin according to the first embodiment and I.
It is a schematic explanatory drawing which shows C chip. In FIG. 1, at least the surface of the terminal 2 of the semiconductor IC chip 1 is made of Au. Further, in FIG. 1, the terminals 2 are omitted except for one. The contact probe to which the contact pin according to the embodiment shown in FIG. 1 is attached has the same configuration as the contact probe 30 disclosed in the above-mentioned related art except for the contact pin portion. In the contact pin 10 shown in FIG. 1, a Ni-based alloy is used for the inner layer 11 because it is required to have high hardness and plastic deformation-resistant characteristics. In the embodiment, for example, a Ni-Mn alloy containing 0.05 to 1.5 wt% of Mn is used as the Ni-based alloy. Here, when the amount of Mn is less than 0.05 wt%, Hv3
A hardness of 50 or more cannot be obtained, and there is a possibility that the hardness will be extremely lowered by heating at high temperature. On the other hand, if it exceeds 1.5 wt%, the stress at the tip end may be increased and the tip may be bent, and it is very brittle and the toughness is deteriorated.
A Ni-Co alloy or the like may be used as the Ni-based alloy.

At the needle tip of the contact pin 10, the tip of the inner layer 11 is exposed to the outside (terminal 2).
Contacting part for energization, and this is the contact pin 10
And the tip portion 10a of the. Then, the surface of the inner layer 11 excluding the tip portion 10a is coated with Au having high conductivity to form the first coating layer 12. Here, the tip portion 1 of the inner layer 11
The reason why the portions other than 0a are coated with Au is that the Ni-Mn alloy has a large electric resistance, so that a loss is large as a signal transmission line, and the signal deteriorates to generate noise. On the other hand, since a high frequency signal generally has a characteristic of flowing on the surface of the contact pin 10 (called a skin effect), it is possible to prevent signal deterioration by coating the surface of the contact pin 10 with Au having good conductivity. .

Next, a method of manufacturing the contact pin 10 according to the above-described embodiment will be described. The process of manufacturing the contact pin 10 is the same as that disclosed in Japanese Patent Publication No. 7-82027, for example. That is, the base metal layer is formed by Cu plating on the stainless steel support substrate. After forming a photoresist layer on the base metal layer, the photoresist layer is exposed by exposing it to a mask with a predetermined pattern, and the photoresist layer is developed to remove the contact pin portion, and the remaining photoresist An opening is formed in the layer. Then, Ni-Mn is formed in this opening as a Ni-based alloy layer to be the contact pin 10.
The alloy is formed by plating. Here, only the tip portion 10a of the contact pin 10 has the inner layer 1 of Ni-Mn alloy.
As a method for exposing 1 to expose it with the first coating layer 12 of Au, a method of masking the tip portion 10a of the inner layer 11 of the manufactured contact pin 10 in advance and performing Au plating is used. Alternatively, a method may be used in which the entire inner layer 11 of the contact pin 10 is covered with Au plating and only the tip 10a is stripped of Au, or any method may be used.

As described above, according to the present embodiment, the contact probe having the contact pin 10 is mounted on the probe card 36 shown in FIGS. 7 and 8 and the needle tip of the contact pin 10 is a semiconductor IC. When the terminal 2 of the chip 1 is brought into contact with the terminal 2, the material of the terminal 2 is Au, whereas the tip 10a of the contact pin 10 which is pressed and brought into contact with the terminal 2 is made of Ni-Mn which is a dissimilar metal having high hardness. Since it is made of an alloy, Au of the terminal 2 does not adhere to the tip portion 10a, and an adhesion phenomenon does not occur. Moreover, since the high-frequency signal transmitted from the terminal 2 to the tip portion 10a flows through the first coating layer 12 made of Au, which is the surface of the contact pin 10, the generation of noise due to signal deterioration is minimized. be able to.

According to the above-described first embodiment, the above-mentioned effects can be obtained, but the tip portion 1 of the contact pin 10 can be obtained.
Since the inner layer 11 of the Ni—Mn alloy is exposed at 0a, the Ni—Mn alloy is oxidized, and as a result, the electrical resistance at the time of contact increases, which may cause poor contact. The second embodiment of the present invention described below is an improvement over such a problem, which will be described with reference to FIG.
The contact pin 14 shown in FIG. 2 covers the entire inner layer 11 made of a Ni—Mn alloy including the tip portion 14a with a metal of the platinum group element, for example, platinum Pt, and the second coating layer 15 is formed.
Are formed. Here, platinum Pt has a conductivity of Au.
Although it is inferior, the hardness of the terminal 2 is high and it is difficult to oxidize.
It is possible to reliably prevent the adhesion phenomenon in which u adheres. still,
As the metal of the platinum group element used for the second coating layer 15, other than platinum Pt, Ru, Ph, Pd, Os, Ir or the like can be adopted.

Next, a modification of the second embodiment will be described with reference to FIG. In FIG. 3, the contact pin 16 is N
The second embodiment in that the second coating layer 15 is formed by coating the entire inner layer 11 made of an i-Mn alloy including the tip portion 16a with a platinum group metal, for example, platinum Pt. Is the same as the contact pin 14 according to. In this modification, the surface of the second coating layer 15 is further provided with Au as a conductive metal in a portion excluding the tip end portion 16a which is a contact portion for energization with the terminal 2.
To form a third coating layer 18. According to this configuration, in addition to the effect of the second embodiment, even if the conductivity of the second coating layer 15 is inferior to Au, the signal transmitted from the terminal 2 to the tip portion 16a is conductive by the skin effect. Since the third coating layer 18 made of Au having good properties is transmitted, it is possible to reliably prevent the generation of noise due to signal deterioration.

Next, a third embodiment of the present invention will be described with reference to FIG. In FIG. 4, the contact pin 20 is N
The inner layer 11 made of an i-Mn alloy is covered with a fourth coating layer 22 made of Au except for the tip 11a. Moreover, at the tip portion 20a of the contact pin 20, the inner layer 1
The first coating layer 24 is formed by coating the tip 11a of the first electrode 11a with a metal of the platinum group, for example, platinum Pt. According to the present embodiment, the tip portion 20a of the contact pin 20 has the platinum P
Since it is covered with the fifth covering layer 24 of t,
Since u does not adhere to the tip portion 20a of the contact pin 20 due to an adhesive phenomenon, and the surface of the inner layer 11 is covered with the Au fourth coating layer 22 except for the tip portion 20a, deterioration of the signal occurs. Can be reliably prevented.

The first coating layer 12, the third coating layer 18, and the fourth coating layer 22 for coating the inner layer 11 made of a Ni--Mn alloy are made of any material such as Ag or Cu instead of Au. It may be configured. Also, regarding the material of the terminal 2,
Alternatively, solder (Pb-Sn) may be used.

[0019]

As described above, in the contact probe according to the present invention, the tip of the contact pin has the inner layer made of the Ni-based alloy, which is covered with the conductive metal except for the contact portion for conducting current. When the energizing contact portion of the contact pin is brought into contact with a terminal such as a semiconductor IC chip or the like which is to be inspected, such as gold or solder, dissimilar metal contacts at the energizing contact portion,
Moreover, since the Ni-based alloy has high hardness, it is possible to prevent the sticking phenomenon that the metal of the terminal adheres. Moreover, the contact pins are
Since the portion other than the energizing contact portion is coated with a conductive metal such as Au, the conductivity is good, and since the skin effect can be used, the signal is transmitted without being deteriorated and high-frequency compatibility is also possible.

Further, in the contact probe according to the present invention, since the needle pin of the contact pin has the inner layer made of the Ni-based alloy coated with the metal of the platinum group element, the contact failure due to the oxidation of the current-carrying contact portion occurs. In addition, since the platinum group metal is a different metal from the terminal such as gold or solder and has a high hardness, the adhesion phenomenon does not occur. Further, since the surface of the metal of the platinum group it is coated with a conductive metal, except the conduction contact portions,
In addition to the adhesion phenomenon not occurring in the energizing contact portion, the signal can be transmitted without deterioration due to the skin effect.

Further, in the contact probe according to the present invention, in the tip of the contact pin, the current contact portion of the inner layer made of the Ni-based alloy is coated with the metal of the platinum group element, and the other portions are made of Au or the like. Since it is covered with a conductive metal, no sticking phenomenon occurs in the energizing contact portion, and the signal is transmitted without deterioration due to the skin effect.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a vertical cross section of a needle tip portion of a contact pin of a contact probe according to a first embodiment of the present invention and a semiconductor IC chip.

FIG. 2 is a vertical sectional view of a needle tip portion of a contact pin according to a second embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view of a needle tip portion of a contact pin showing a modified example of the second embodiment.

FIG. 4 is a vertical cross-sectional view of a needle tip portion of a contact pin according to a third embodiment of the present invention.

FIG. 5 is a schematic plan view of a conventional contact probe.

6 is a partial vertical cross-sectional view of a contact pin portion of the contact probe shown in FIG.

7 is an exploded perspective view of a probe card equipped with the contact probe shown in FIGS. 5 and 6. FIG.

8 is a vertical cross-sectional view showing a state in which a contact probe of the probe card shown in FIG. 7 is mounted.

FIG. 9 is a vertical cross section of a conventional contact pin and a semiconductor IC.
It is a schematic explanatory drawing which shows a chip.

FIG. 10 is a diagram showing a gold adhesion state between needle tips of adjacent contact pins.

[Explanation of symbols]

2 terminals 10, 14, 16, 20 Contact pins 10a, 16a, 20a Tip 11 inner layer 12 First coating layer 15 Second coating layer 18 Third coating layer 22 Fourth coating layer 24 Fifth coating layer 30 contact probe

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshinobu Ishii Technopark 12 No. 6 in Mita City, Hyogo Prefecture Mitsubishi Materials Corporation Mita Factory (56) Reference JP-A-7-326231 (JP, A) Special Features Kaihei 6-324081 (JP, A) Registered utility model 3039278 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01R 1/06-1/073 G01R 31/26 H01L 21 / 66

Claims (3)

(57) [Claims] 1. A plurality of pattern wirings are formed on a film, and each tip of these pattern wirings is the film.
In the contact probe protruding from the above to form a contact pin, the needle tip of the contact pin is characterized in that an inner layer made of a Ni-based alloy is coated with Au, Ag or Cu except for the contact portion for energization. Contact probe. 2. A plurality of pattern wirings are formed on a film, and each tip of these pattern wirings is the film.
In the contact probe protruding from the contact pin, the tip of the contact pin has an inner layer made of a Ni-based alloy coated with a platinum group metal, and the platinum group metal surface has a surface other than a contact portion for conduction. A
A contact probe coated with u, Ag or Cu. 3. A plurality of pattern wirings are formed on a film, and each tip of these pattern wirings is the film.
In the contact probe projecting from the contact pin, the tip of the contact pin has an inner layer made of a Ni-based alloy, the current-carrying contact part is covered with a platinum group metal, and the other part is Au, Ag, or A contact probe coated with Cu.