Electrical Connection Device

Abstract

To provide an electrical connection device capable of preventing adhesion between probes and wiring board lands.SOLUTION: An electrical connection device 1 is provided, comprising a wiring board 20 having lands 21 disposed on a main surface thereof, and probes 10. Each probe 10 comprises a tip end portion 12 to be in contact with an object 2 under measurement and a base end portion 11 to be in contact with a land 21. A surface film of the base end portion 11 to be in contact with the land 21 is made of a metallic material having a different composition from that of a material of the land 21 to be in contact with the surface film.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electrical connecting device used for measuring electrical characteristics of a measurement object. [Background technology]

[0002] In order to measure the characteristics of a measurement object such as an integrated circuit, an electrical connection device having a probe that is brought into contact with the measurement object is used. In a measurement using an electrical connection device, one end of the probe is brought into contact with the measurement object. Then, the other end of the probe is brought into contact with an electrode terminal (hereinafter referred to as a "land") arranged on a wiring board. The land is connected to a measurement device such as an IC tester, and an electrical signal is transmitted between the measurement object and the measurement device via the probe and the wiring board.

[0003] The probe employs a structure in which a base film and a surface film are laminated on the surface of a core material (see Patent Document 1). For example, a gold (Au) film is used for the surface film of the probe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-117882 A Summary of the Invention [Problem to be solved by the invention]

[0005] The lower the electrical resistance at the contact point between the probe and the land, the better. For this reason, Au films are used for the surface films of the lands on the wiring board and the probes. However, problems arise when the Au film on the land adheres to the Au film on the surface film. That is, the surface film of the probe peels off when the probe is separated from the land, or the probe comes off from the probe head when the probe head holding the probe is removed from the wiring board.

[0006] In view of the above problems, an object of the present invention is to provide an electrical connecting device capable of suppressing adhesion between the probe and the land of the wiring board. [Means for solving the problem]

[0007] According to one aspect of the present invention, a wiring board having lands arranged on a main surface thereof and a probe having a tip portion in contact with a measurement object and a base portion in contact with the land, the base portion having a surface film made of a material different in composition from the material of the land, the base portion of the probe having a structure including an undercoat film covering a core material and a surface film covering the undercoat film, the undercoat film functions as a barrier film that prevents metal atoms contained in the core material from diffusing from the core material to the surface film, the base portion of the probe is configured to freely contact and separate from the land, the undercoat film and the surface film are formed to cover the side and end faces of the core material only at the base portion, the contact surface at the contact point of the base portion with the land is flat, and the area of ​​the contact surface is 100 mm or less than the area of ​​the base portion. In Perpendicular to the probe axis Cross-sectional area of ​​core material A wider electrical connection arrangement is provided. Effect of the Invention

[0008] According to the present invention, it is possible to provide an electrical connecting device capable of suppressing adhesion between the probe and the land of the wiring board. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a configuration of an electrical connecting device according to an embodiment; [Diagram 2] 3 is a schematic cross-sectional view showing the structure of a base end portion of a probe of the electrical connecting device according to the embodiment. FIG. [Diagram 3] FIG. 2 is a schematic diagram showing peeling of a surface film. [Figure 4] FIG. 2 is a schematic diagram showing a state in which a probe is removed from a probe head. [Diagram 5] 11 is a schematic cross-sectional view showing another structure of the base end portion of the probe of the electrical connecting device according to the embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the thickness ratios of each part are different from the actual ones. Of course, the drawings also include parts with different dimensional relationships and ratios. The embodiments shown below are examples of devices and methods for embodying the technical ideas of this invention, and the embodiments of this invention do not specify the materials, shapes, structures, arrangements, etc. of the components as described below.

[0011] 1 is used to measure electrical characteristics of a measurement target object 2. The electrical connection device 1 includes a probe 10, a probe head 30 that holds the probe 10, and a wiring board 20 to which the probe head 30 is attached. The probe head 30 is fixed to the wiring board 20 by bolts or the like (not shown).

[0012] The electrical connecting device 1 is a vertically operating probe card, and when the object to be measured 2 is measured, the tip 12 of the probe 10 comes into contact with an electrode pad (not shown) of the object to be measured 2. Fig. 1 shows a state in which the probe 10 is not in contact with the object to be measured 2. During measurement, for example, a chuck 3 carrying the object to be measured 2 rises, and the tip 12 of the probe 10 comes into contact with the object to be measured 2.

[0013] Lands 21 made of a conductive material are arranged on the main surface of the wiring board 20 facing the probes 10. The base ends 11 of the probes 10 are connected to the lands 21. Meanwhile, connection terminals 22 are arranged on the other main surface of the wiring board 20, and the lands 21 and the connection terminals 22 are electrically connected by a wiring pattern (not shown) formed on the wiring board 20. The connection terminals 22 are connected to a measuring device (not shown). A printed circuit board or the like is used for the wiring board 20.

[0014] The probe head 30 employs a structure having a plurality of guide plates. In the probe head 30 shown in Fig. 1, a top guide plate 31 and a bottom guide plate 32 are arranged at a distance from each other by a spacer 33 along the extension direction of the probe 10. The probe 10 is held by the probe head 30 in a state in which the probe 10 penetrates guide holes formed in the top guide plate 31 and the bottom guide plate 32. The material of the probe head 30 is, for example, ceramic.

[0015] When measuring the object 2, an electrical signal propagates between the measurement device and the object 2 via the wiring board 20 and the probe 10. For example, an electrical signal is transmitted from the measurement device to the object 2 via the wiring board 20 and the probe 10, and an electrical signal output from the object 2 is transmitted to the measurement device. For this reason, the land 21 and the probe 10 are made of a conductive material.

[0016] The base end 11 of the probe 10 has a structure that reduces the electrical resistance at the contact point between the base end 11 and the land 21. For example, as shown in Fig. 2, the base end 11 has a structure including an undercoat film 112 that covers a core material 111 and a surface film 113 that covers the undercoat film 112.

[0017] Conductive metals such as copper (Cu) alloy, silver-palladium-copper (AgPdCu) ​​alloy, rhodium (Rh), and nickel (Ni) are used for the core material 111. The undercoat film 112 functions as a barrier film that prevents diffusion of metal atoms between the core material 111 and the surface film 113 or a strike plating film formed between the surface film 113 and the undercoat film 112. For example, when an Au plating film is used for the surface film 113 or the strike plating film, a Ni film is formed as the undercoat film 112 to prevent Cu from diffusing from the core material 111 such as a Cu alloy into the Au plating film. As a barrier film at the Cu / Au interface, a titanium (Ti) film, a chromium (Cr) film, a palladium (Pd) film, and the like can be used for the undercoat film 112. Depending on the material of the core material 111, the undercoat film 112 may not be necessary. A conductive metal film is also used for the surface film 113, and although details will be described later, a metal material with a different composition from the material of the lands 21 is used for the surface film 113. In addition, by plating the core material 111 with the base film 112 and the surface film 113, oxidation of the Cu alloy core material 111 can be suppressed.

[0018] In order to reduce the electrical resistance at the contact points between the probe 10 and the land 21, an Au film is used as the material for the surface film 113 and the land 21. However, when an Au film is used for each of the land 21 and the surface film 113 of the probe 10, a problem occurs in that the Au film of the surface film 113 and the Au film of the land 21 adhere to each other. If the Au film of the land 21 and the Au film of the surface film adhere to each other, the surface film 113 of the probe 10 peels off when the probe 10 is separated from the land 21, as shown in FIG. 3. The Au film 110 peeled off from the probe 10 adheres to the surface of the land 21.

[0019] When the measurement of the measurement target 2 is repeated, the phenomenon that the Au film peeled off from the probe 10 adheres to the surface of the land 21 is repeated. Therefore, the thickness of the Au film adhered to the surface of the land 21 gradually increases. This causes problems such as fluctuations in the contact state between the probe 10 and the land 21, and a decrease in measurement accuracy. In addition, the phenomenon of the Au film adhering to the surface of the land 21 causes variations in the height of the multiple lands 21 arranged on the wiring board 20. As a result, the position of the tip 12 of the probe 10 varies, and the needle pressure of the probe 10 in contact with the measurement target 2 becomes non-uniform.

[0020] Furthermore, if the Au film of the land 21 and the Au film of the surface film 113 are adhered to each other, the probes 10 may come off from the probe head 30 when the probe head 30 is removed from the wiring board 20 in the direction of the arrow, as shown in Fig. 4. In the example shown in Fig. 4, the second and fifth probes 10 from the left side of the page have come off from the probe head 30.

[0021] 1, the material of the portion of the surface film 113 that contacts the land 21 is a metal material having a different composition from the material of the portion of the land 21 that contacts the base end 11. This makes it possible to suppress adhesion between the surface film 113 of the probe 10 and the land 21.

[0022] For example, when the material of the land 21 is an Au film, a conductive precious metal is used as the material of the surface film 113 of the probe 10. Here, a "precious metal" is a metal other than a base metal that is not easily ionized and is not easily oxidized, for example, even when heated in air. For this reason, a conductive precious metal can be suitably used as the material of the surface film 113. For example, the precious metal used as the material of the surface film 113 can be one metal selected from the group of metals consisting of Pd, iridium (Ir), platinum (Pt), ruthenium (Ru), Rh, etc., or an alloy containing one of the above metals.

[0023] For example, when a Cu alloy having a diameter of about 30 μm is used for the core material 111, a Ni film having a thickness of about 4.5 μm is used for the base film 112, and a precious metal film having a thickness of about 1.0 μm is used for the surface film 113. Alternatively, when a Cu alloy having a diameter of about 35 μm is used for the core material 111, a Ni film having a thickness of about 6.5 μm is used for the base film 112, and a precious metal film having a thickness of about 1.0 μm is used for the surface film 113. The base film 112 and the surface film 113 are formed by, for example, plating.

[0024] Depending on the combination of materials for the base film 112 and the surface film 113, the contact between the base film 112 and the surface film 113 may be reduced. In such a case, as shown in Fig. 5, a strike plating film 114 may be formed between the base film 112 and the surface film 113. That is, instead of forming the surface film 113 directly on the surface of the base film 112, the strike plating film 114 is formed to cover the surface of the base film 112. Then, the surface film 113 is formed to cover the strike plating film 114.

[0025] By forming the strike plating film 114, the passive film of the underlayer 112 is removed and activated, thereby improving the adhesion between the underlayer 112 and the surface film 113. The strike plating film 114 is, for example, an Au film.

[0026] Furthermore, a conductive precious metal may be used as the material of the land 21. In this case, a precious metal having a different composition from the precious metal used for the land 21 may be used as the material of the surface film 113 of the probe 10. Alternatively, an Au film may be used as the material of the surface film 113, and a conductive precious metal may be used as the material of the land 21. The precious metal used as the material of the land 21, like the precious metal used as the material of the surface film 113, is one type of metal selected from the group of metals consisting of Pd, Ir, Pt, Ru, Rh, etc., or an alloy containing one of the above metals.

[0027] As described above, in the electrical connecting device 1 according to the embodiment of the present invention, the material of the surface film 113 of the base end 11 of the probe 10 is a metal material having a different composition from the material of the land 21 that contacts the base end 11. Therefore, according to the electrical connecting device 1, adhesion between the probe 10 and the land 21 of the wiring board 20 can be suppressed.

[0028] (Other embodiments) Although the present invention has been described above by way of the embodiment, the description and drawings forming part of this disclosure should not be understood as limiting the present invention. Various alternative embodiments, examples and operating techniques will become apparent to those skilled in the art from this disclosure.

[0029] For example, the above describes the case where a precious metal is used as the material for the surface film 113 and the land 21, but as long as the composition of the material for the surface film 113 and the material for the land 21 are different, a metal material other than a precious metal may be used as the material for the surface film 113 and the land 21.

[0030] Thus, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention-specifying matters related to the scope of the claims appropriate from the above description. [Explanation of symbols]

[0031] 1...Electrical connection device 2...Measurement object 10…Probe 11...Proximal end 12...Tip 20...Wiring board 21…Land 30…Probe head 111...Core material 112...Base film 113…Surface film 114...Strike plating film

Claims

1. An electrical connection device used to measure an electrical characteristic of a measurement object, comprising: A wiring board having lands of a conductive material disposed on a main surface thereof; a probe having a tip portion that contacts the object to be measured during measurement and a base portion that contacts the land, the material of a surface film of the base portion that contacts the land being a metallic material having a composition different from that of the material of the land that contacts the surface film, thereby suppressing adhesion between the surface film and the land; Equipped with The base end of the probe has a structure including a base film covering a core material and the surface film covering the base film, the undercoat film functions as a barrier film that prevents metal atoms contained in the core material from diffusing from the core material to the surface film, The base end of the probe is configured to be freely brought into contact with and separated from the land, the undercoat film and the surface film are formed so as to cover the side and end faces of the core material only at the base end portion, A contact surface of the base end where the base end comes into contact with the land is flat, and the area of ​​the contact surface is larger than a cross-sectional area of ​​the core material perpendicular to the axial direction of the probe at the base end.

1. An electrical connecting device comprising:

2. At least one of the surface film and the land is made of a conductive precious metal, The noble metal is a metal selected from the group consisting of palladium, iridium, platinum, ruthenium, and rhodium, or an alloy containing the metal.

2. The electrical connecting device according to claim 1.

3. 3. The electrical connecting device according to claim 2, wherein the material of said surface film is said noble metal, and the material of said land is gold.

4. 3. The electrical connecting device according to claim 2, wherein the material of said surface film is gold, and the material of said land is said noble metal.

5. 3. The electrical connecting device according to claim 2, wherein the surface film and the land are made of precious metals having different compositions.

6. 2. The electrical connecting device according to claim 1, wherein a strike plating film is formed between the undercoat film and the surface film.

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