Probe

Abstract

A probe (10) comprises a columnar body section (11) that extends in the axial direction, a tip section (12) that is connected to one end of the body section (11) and contacts an object to be inspected during inspection, and a base end section (13) connected to the other end of the body section (11). The base end section (13) includes a plurality of connection sections (130) each having: a linking section (131) elastically connecting to the body section (11); and a contact section (132) of which a first end is connected to the linking section (131).

Description

probe

[0001] The present invention relates to a probe used for inspecting electrical characteristics of an object under test.

[0002] An electrical connection device including a probe is used to test the electrical characteristics of a test object such as a semiconductor integrated circuit in a wafer state. In a test using a probe, one end of the probe contacts an electrode of the test object, and the other end of the probe contacts a terminal (hereinafter referred to as a "land") arranged on a substrate included in the electrical connection device. The land is electrically connected to a tester or other test device.

[0003] Japanese Patent Application Laid-Open No. 2018-4260

[0004] In order to accurately test the electrical characteristics of an object under test, it is necessary to stably connect the object under test and the land via a probe. An object of the present invention is to provide a probe that can stably connect the object under test and the land electrically.

[0005] A probe according to one aspect of the present invention includes a columnar body extending in an axial direction, a tip end connected to one end of the body and adapted to contact an object under test during testing, and a base end connected to the other end of the body, the base end including a plurality of connecting portions each having a connecting portion that is elastic and connects to the body, and a contact portion whose first end is connected to the connecting portion.

[0006] According to the present invention, it is possible to provide a probe that stabilizes the electrical connection between the object to be inspected and the land.

[0007] FIG. 1 is a schematic diagram showing the configuration of a probe according to the first embodiment. FIG. 2 is a schematic diagram showing the configuration of a base end portion of a probe according to the first embodiment. FIG. 3 is a schematic diagram showing the configuration of an electrical connection device including a probe according to the first embodiment. FIG. 4 is a schematic diagram showing an example of the arrangement of a coupling portion of a probe according to the first embodiment. FIG. 5 is a schematic diagram showing the configuration of an electrical connection device including a probe of a comparative example. FIG. 6 is a schematic diagram showing the structure of a coupling portion of a probe according to a modification of the first embodiment. FIG. 7 is a schematic diagram showing another structure of a coupling portion of a probe according to a modification of the first embodiment. FIG. 8 is a schematic diagram showing another structure of a coupling portion of a probe according to a modification of the first embodiment. FIG. 9 is a schematic diagram showing the configuration of a probe according to the second embodiment. FIG. 10 is a schematic diagram showing the structure of a base end portion of a probe according to a modification of the second embodiment. FIG. 11 is a schematic diagram showing the configuration of an electrical connection device of another embodiment.

[0008] Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, identical or similar parts are designated by identical or similar reference numerals. However, it should be noted that the drawings are schematic, and the thickness ratios of the various parts may differ from those in reality. Furthermore, it goes without saying that the dimensional relationships and ratios of parts included in the drawings may differ from one another. The embodiments shown below exemplify devices and methods for embodying the technical ideas of the present invention, and the materials, shapes, structures, and arrangements of the components of the embodiments of the present invention are not limited to those described below.

[0009] First Embodiment A probe 10 according to a first embodiment shown in FIG. 1 is used to test electrical characteristics of a test object. The probe 10 includes a columnar body 11 extending in an axial direction, a tip 12 connected to one end of the body 11 and contacting the test object during testing, and a base 13 connected to the other end of the body 11. Hereinafter, the axial direction of the body 11 will also be referred to simply as the "axial direction." As shown in FIG. 1, the body 11 and the tip 12 may be integrally configured. The base 13 includes a plurality of connecting portions 130. Each connecting portion 130 has a coupling portion 131 that is elastic and connects to the body 11, and a contact portion 132 that connects to the coupling portion 131.

[0010] In the following description, the direction in the axial direction in which the base end 13 is located as viewed from the tip end 12 will be referred to as "upward," and the direction in which the tip end 12 is located as viewed from the base end 13 will be referred to as "downward." For example, the contact portion 132 is located above the connecting portion 131. In addition, the upward-facing surface of each portion of the probe 10 will be referred to as the top surface, the downward-facing surface will be referred to as the bottom surface, and the surface connecting the top surface and bottom surface will be referred to as the side surface.

[0011] 1 has three connection portions 130 at the base end portion 13, the number of connection portions 130 at the base end portion 13 may be two, or may be four or more. In the following, an example will be described in which the base end portion 13 has three connection portions 130 as shown in FIG.

[0012] As shown in FIG. 2 , the connecting portion 131 has a beam portion 1311 connected to the main body portion 11 and extending in a direction perpendicular to the axial direction, and a support portion 1312 connected to the beam portion 1311 and extending in the axial direction. A first end 132a of the contact portion 132 is connected to the support portion 1312 of the connecting portion 131. The contact portion 132 extends parallel to the axial direction. When viewed from the axial direction, the main body portion 11 and the contact portion 132 are spaced apart. A second end 132b of the contact portion 132 is included in a plane level perpendicular to the axial direction, at a position axially extended from the other end of the main body portion 11 to which the base end portion 13 is connected. As will be described later, the second end 132b of the contact portion 132 contacts a land during testing of a test object. The larger the diameter of the contact portion 132, the more stable the contact between the land and the probe 10. Although an example has been shown in which the diameter of the contact portion 132 is larger than the diameter of the connecting portion 131, the diameters of the contact portion 132 and the connecting portion 131 may be approximately the same. In order to arrange the probes 10 at a narrow pitch, it is preferable that the diameter of the contact portion 132 is small. Note that the end surface of the second end 132b of the contact portion 132 may be configured so as to remove the oxide film on the surface of the land. For example, the end surface of the second end 132b may be formed with irregularities.

[0013] The cross section of the main body 11 perpendicular to the axial direction (hereinafter simply referred to as the "cross section") may be, for example, circular or polygonal. In this embodiment, a case where the cross section of the main body 11 is circular will be described as an example. To electrically connect the electrodes of the test object to the lands, a conductive material such as a metal material is used for the probe 10. For example, the probe 10 may be made of nickel (Ni), a nickel alloy, gold (Au), silver (Ag), copper (Cu), palladium (Pd), a palladium alloy, rhodium (Rh), a rhodium alloy, or other precious metals.

[0014] The probe 10 is used in, for example, an electrical connection device 100 shown in FIG. 3 . During testing of an object under test 200, the tip 12 of the probe 10 contacts an electrode pad (not shown) of the object under test 200. The connection portion 130 of the base end 13 of the probe 10 is connected to a land 21 of the substrate 20. Specifically, the second end 132b of the contact portion 132 is connected to the land 21. As shown in FIG. 3 , multiple contact portions 132 included in the same base end 13 are connected to a single land 21. The other end of the main body 11 is located below the second end 132b of the contact portion 132, and a space is interposed between the end of the main body 11 and the substrate 20. The substrate 20 is, for example, a printed circuit board or a space transformer. The land 21 is electrically connected to a testing device such as an IC tester (not shown).

[0015] The tip of the second end 132b of the contact portion 132 may be a flat surface perpendicular to the axial direction of the probe 10. By making the tip of the second end 132b a flat surface, it is possible to increase the contact area between the contact portion 132 and the land. The larger the contact area between the contact portion 132 and the land, the larger the current that can flow through the probe 10.

[0016] The electrical connecting device 100 may be configured by joining the base end 13 of the probe 10 to the land 21. The connecting method and connecting material for joining the probe 10 to the land 21 may be selected arbitrarily. For example, the second end 132b of the contact portion 132 of the probe 10 may be joined to the land 21 by soldering.

[0017] Because the linking portion 131 of the connecting portion 130 is elastic, when the tip end 12 of the probe 10, with the base end 13 connected to the land 21, is brought into contact with the test object 200, the probe 10 can be elastically deformed along the axial direction. In other words, the main body 11 of the probe 10 is linear and therefore does not have axial elasticity, but the probe 10 as a whole has axial elasticity. Therefore, after the probe 10 is brought into contact with the test object 200, an overdrive can be applied to press the probe 10 against the test object 200. The overdrive can ensure electrical connection between the probe 10 and the test object 200. Furthermore, the base end 13 of the probe 10 has multiple contact portions 132, allowing the probe 10 to stably contact the land 21.

[0018] After the inspection of the inspection object 200 is completed, the probe 10 is separated from the inspection object 200. The connecting portion 131 is formed so as to undergo elastic deformation to return to its original shape after the probe 10 is separated from the inspection object 200. For example, the diameter of the beam portion 1311 of the connecting portion 131 may be made relatively smaller than that of the main body portion 11, thereby making the connecting portion 131 elastic. Alternatively, the connecting portion 131 may be made elastic by using a material for the connecting portion 131 that is less rigid than the main body portion 11. Furthermore, as will be described later, a slit may be provided in the connecting portion 131.

[0019] As shown in FIG. 4 , when viewed from the axial direction of the probe 10, the angle θ between adjacent coupling portions 131 may be the same for all coupling portions 131. For example, if the base end portion 13 has three connection portions 130, the angle θ is approximately 120 degrees. By having the multiple coupling portions 131 extend from the main body portion 11 with equal angles between them, the probe 10 can be stably contacted with the lands 21. For example, the orientation of the probe 10 can be maintained perpendicular to the surface of the substrate 20 on which the lands 21 are arranged. Furthermore, the multiple connection portions 130 of the base end portion 13 contact the lands 21 with the same pressure.

[0020] However, a comparative probe (hereinafter referred to as "comparative probe 10M"), which has one end of a columnar body as a tip that contacts the test object and the other end connected to a land at a single point at the base end, does not have axial elasticity in the probe itself. For this reason, overdrive is applied by bending the body of comparative probe 10M, as in the comparative electrical connecting device shown in Figure 5.

[0021] In the comparative electrical connection device shown in FIG. 5 , a comparative probe 10M is held by a probe head 30 having a bottom guide plate 31 and a top guide plate 32. The bottom guide plate 31 is disposed around the tip end of the comparative probe 10M. The top guide plate 32 is disposed around the base end of the comparative probe 10M. The probe head 30 further includes a first guide film 34 and a second guide film 35 spaced apart from each other in a space defined by a spacer 33 sandwiched between the top guide plate 32 and the bottom guide plate 31. The top guide plate 32 and the bottom guide plate 31 (hereinafter collectively referred to as "guide plates") are made of, for example, a ceramic material. The first guide film 34 and the second guide film 35 (hereinafter collectively referred to as "guide films") are made of, for example, a resin film. The comparative probe 10M passes through guide holes (not shown) formed in the guide plates and guide films.

[0022] In the probe head 30 shown in Fig. 5, the guide holes through which the same comparative probe 10M passes are offset in position in the top guide plate 32 relative to the guide holes in the bottom guide plate 31, with the guide holes being displaced parallel to the main surface of the bottom guide plate 31. Due to the offset arrangement, the main body of the comparative probe 10M is curved inside the probe head 30, as shown by the solid line in Fig. 5. That is, the comparative probe 10M is curved due to elastic deformation in the hollow region between the bottom guide plate 31 and the top guide plate 32.

[0023] Because the guide plates are offset, when the tip of the comparative probe 10M comes into contact with the test object, the comparative probe 10M buckles in the hollow region. That is, in the contact state where the comparative probe 10M is in contact with the test object, the comparative probe 10M further bends due to flexural deformation as shown by the dashed line in Figure 5. As the comparative probe 10M further bends, it comes into contact with the test object 200 at a predetermined pressure.

[0024] 5, deformation of the comparative probe 10M causes friction between the comparative probe 10M and the guide plate and guide film, which results in problems such as insufficient contact between the comparative probe 10M and the land 21 or the object under test, and insufficient conductivity between the object under test and the land 21.

[0025] In contrast, the probe 10 does not need to be held in a curved state with the main body 11. In other words, there is no friction between the probe 10 and the guide plate or guide film, and conductivity between the test object 200 and the lands 21 is stable.

[0026] As described above, the probe 10 according to the embodiment includes a plurality of connection portions 130 each having a contact portion 132 that connects to the main body portion 11 via a linking portion 131. Therefore, the probe 10 can stabilize the electrical connection between the test object 200 and the land 21.

[0027] 6, in the probe 10 according to the modification of the first embodiment, a slit 1310 penetrating the coupling portion 131 in a direction parallel to the axial direction of the beam portion 1311 is formed in each coupling portion 131 of the plurality of connection portions 130. According to the probe 10 shown in FIG. 6, by providing the slit 1310 penetrating from the upper surface to the lower surface in the beam portion 1311 of each coupling portion 131, it is possible to adjust the needle pressure (hereinafter also simply referred to as "needle pressure") with which the probe 10 contacts the test object 200.

[0028] 7, a slit 1310 may be formed in the beam 1311 so as to penetrate the connecting portion 131 in a direction perpendicular to the axial direction. By providing the slit 1310 in the beam 1311 so as to penetrate in the lateral direction, the stylus pressure can be adjusted.

[0029] 8, the slits 1310 formed in the beam portions 1311 of the plurality of connecting portions 131 may be connected to each other at the portions where the connecting portions 131 are connected to the main body portion 11. By connecting the slits 1310 to each other, the needle pressure can be adjusted across the plurality of connecting portions 131 as a whole.

[0030] Second Embodiment As shown in Fig. 9, a probe 10 according to a second embodiment has a connecting portion 131 that is connected to a main body portion 11 and includes a beam portion 1311 that is elastically curved, and a support portion 1312 that connects the beam portion 1311 and a contact portion 132. The probe 10 shown in Fig. 9 differs from the probe 10 according to the first embodiment shown in Fig. 1 in that the connecting portion 131 includes a curved portion. In other respects, the second embodiment is similar to the first embodiment.

[0031] In the probe 10 shown in Fig. 9, the connecting portion 131 includes a curved portion, so that the connecting portion 131 is more likely to bend when the probe 10 comes into contact with the test object. Therefore, the probe 10 shown in Fig. 9 can apply a stronger overdrive. As a result, the probe 10 can be more stably brought into contact with the test object. In other respects, the probe 10 according to the second embodiment is substantially the same as that of the first embodiment, and therefore, redundant description will be omitted.

[0032] <Modification> In a modification of the probe 10 according to the second embodiment, as shown in Fig. 10, the connecting portion 131 includes a first arm 1311a and a second arm 1311b. The first arm 1311a and the second arm 1311b are arranged in parallel and are each connected to the main body 11. The first arm 1311a extends linearly at an angle obliquely intersecting the axial direction in a direction away from the main body 11. The second arm 1311b has an elastically curved portion. A support portion 1312 is connected to the joint between the first arm 1311a and the second arm 1311b.

[0033] In the probe 10 shown in Fig. 10, the second arm 1311b has a portion that bends elastically, so that the elasticity of the connecting portion 131 that bends when the probe 10 comes into contact with the test object is increased. As a result, a strong overdrive can be applied. Although Fig. 10 shows an example in which the connecting portion 131 includes the first arm 1311a and the second arm 1311b, the connecting portion 131 may be configured with three or more arms, including at least one arm that has a portion that bends elastically.

[0034] Although the present invention has been described above by way of the embodiments, the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

[0035] For example, although the above description exemplifies a case in which the number of connecting portions 130 constituting the base end portion 13 is three, the number of connecting portions 130 constituting the base end portion 13 may be two. The fewer the number of connecting portions 130, the closer the probes 10 can be arranged to each other. Furthermore, the number of connecting portions 130 constituting the base end portion 13 may be three or more. The greater the number of connecting portions 130, the higher the allowable value of the current flowing through the probe 10 can be.

[0036] Although the electrical connecting device 100 in which the contact portion 132 of the probe 10 is bonded to the land 21 has been described above, the electrical connecting device may also be configured so that the contact portion 132 and the land 21 can freely contact and separate. For example, as in the electrical connecting device 101 shown in FIG. 11 , the probe 10 may be held by a probe head 30. The probe head 30 may include a guide plate formed with multiple guide holes through which the probes 10 respectively pass. The probe head 30 holds the multiple probes 10 with each probe 10 passing through a different guide hole. This prevents adjacent probes 10 from contacting each other. Furthermore, by holding the probe 10 by the probe head 30, the contact portion 132 of the probe 10 does not need to be bonded to the land 21. Since the contact portion 132 is not bonded to the land 21, the probe 10 can be easily replaced, for example, if a malfunction occurs in the probe 10. Furthermore, the probe 10 may be formed with a stopper having an outer diameter greater than the inner diameter of the guide hole. The stopper catches around the opening of the guide hole of the probe head 30, thereby preventing the probe 10 from falling off the probe head 30.

[0037] Thus, it goes without saying that the present invention includes various embodiments that are not described above.

[0038] The entire contents of Japanese Patent Application No. 2023-209330 (filing date: December 12, 2023) are incorporated herein by reference.

Claims

1. A probe used for testing electrical characteristics of an object under test, comprising: a columnar body extending in an axial direction; a tip connected to one end of the body and contacting the object under test during the test; and a base connected to the other end of the body, the base including a plurality of connecting portions, each having a coupling portion that is elastically connected to the body, and a contact portion whose first end is connected to the coupling portion.

2. A probe as claimed in claim 1, wherein the second end of said contact portion is included at a plane level perpendicular to said axial direction at a position extended in said axial direction from the position of said other end of said body portion.

3. The probe according to claim 1 or 2, wherein a slit is formed in the connecting portion, penetrating the connecting portion in a direction parallel to the axial direction.

4. The probe according to claim 1 or 2, wherein a slit is formed in the connecting portion, penetrating the connecting portion in a direction perpendicular to the axial direction.

5. The probe according to claim 4, wherein the slits of the multiple connecting portions communicate with each other at the portions where the connecting portions are connected to the main body portion.

6. The probe according to claim 1 or 2, wherein the connecting portion has a portion extending in a direction perpendicular to the axial direction, and the contact portion extends parallel to the axial direction.

7. The probe according to claim 1 or 2, wherein the connecting portion includes a portion that is elastically bent.

8. The probe of claim 1 or 2, wherein the coupling portion includes a first arm and a second arm disposed in parallel with the first arm.

9. The probe according to claim 8, wherein said first arm extends linearly in a direction away from said body portion at an angle obliquely intersecting said axial direction, and said second arm includes a portion which is elastically curved.

10. The probe according to claim 1 or 2, wherein the angles formed between adjacent connecting portions when viewed in the axial direction are the same for all of the connecting portions.

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