Probe

Abstract

A probe according to the present invention comprises: a tip member which has a support part; and a base material in which a joining region is formed by retracting a part of a side surface thereof in the thickness direction perpendicular to the axial direction within a certain range from one end along the axial direction. A first side surface of the support part of the tip member and the retracted facing side surface of the base material exposed to the joining region abut with each other, thereby joining the tip member and the base material. A protrusion that protrudes in the thickness direction is formed on one of the first side surface and the facing side surface, and a recess that engages with the protrusion is formed in the other of the first side surface and the facing side surface.

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 while the object is in a wafer state. In a test using a probe, one end of the probe is brought into contact with an electrode of the test object, and the other end of the probe is brought into contact with a terminal (hereinafter referred to as a "land") arranged on a printed circuit board or the like. The land is electrically connected to a tester or other test device.

[0003] Japanese Patent Application Laid-Open No. 2007-147518

[0004] To prevent the tip of a probe from wearing down due to contact with an object to be inspected, a probe is used in which a tip member made of a hard material that is harder than the base material is joined to one end of a columnar base material. The present invention aims to provide a probe in which the tip member is prevented from coming off the base material.

[0005] According to one aspect of the present invention, there is provided a probe including a tip member having a support portion and a base material having a bonding region formed by recessing a portion of a side surface in a thickness direction perpendicular to the axial direction within a certain range from one end along the axial direction. The tip member and the base material are bonded together by abutting a first side surface of the support portion of the tip member against the recessed side surface exposed in the bonding region of the base material. One of the first side surface and the recessed side surface has a protrusion that protrudes in the thickness direction, and the other of the first side surface and the recessed side surface has a recess that mates with the protrusion.

[0006] According to the present invention, it is possible to provide a probe in which the tip member is prevented from coming off the base material.

[0007] FIG. 1 is a schematic cross-sectional view showing the configuration of a probe according to a first embodiment of the present invention. FIG. 2 is a schematic perspective view showing the configuration of a probe according to the first embodiment of the present invention. FIG. 3 is a schematic view showing the configuration of an electrical connecting device using the probe according to the first embodiment of the present invention. FIG. 4 is a schematic view showing a state in which the probe according to the first embodiment of the present invention is in contact with an object to be tested. FIG. 5 is a schematic cross-sectional view showing the configuration of a probe according to a modified example of the first embodiment of the present invention. FIG. 6A is a schematic cross-sectional view showing the configuration of a convex portion and a concave portion of a probe according to a modified example of the first embodiment of the present invention. FIG. 6B is a schematic cross-sectional view showing another configuration of the convex portion and the concave portion of a probe according to a modified example of the first embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing the configuration of a probe according to a second embodiment of the present invention. FIG. 8 is a schematic cross-sectional view showing the configuration of a probe according to a third embodiment of the present invention. FIG. 9 is a schematic cross-sectional view showing the configuration of a probe according to a modified example of the third embodiment of the present invention. FIG. 10 is a schematic view showing the configuration of a probe according to another embodiment of the present invention.

[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. 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, arrangements, and manufacturing methods of the components of the embodiments of the present invention are not limited to those described below.

[0009] (First embodiment) A probe 1 according to the first embodiment shown in Fig. 1 is used to inspect the electrical characteristics of an object under test. The probe 1 comprises a tip member 10 and a base material 20. The tip member 10 has a protrusion 11 that comes into contact with the object under test, and a support portion 12 that is connected to the protrusion 11. The tip member 10 is joined to the base material 20 at the support portion 12. Fig. 1 is a cross-sectional view taken along the central axis of the probe 1.

[0010] As shown in Figures 1 and 2, the direction in which the columnar-shaped base material 20 extends is the axial direction D1, the direction perpendicular to the axial direction D1 and in which the support portion 12 and the base material 20 face each other is the thickness direction D2, and the direction perpendicular to the axial direction D1 and the thickness direction D2 is the width direction D3.

[0011] A joining region 200 is formed in the base material 20 by recessing a portion of the side surface of the base material 20 in the thickness direction D2 over a certain range from one end (hereinafter also referred to as "first end portion 21") along the axial direction D1. The joining region 200 is a space created by recessing a portion of the side surface of the base material 20 in the central axial direction, and the recessed side surface is exposed in the joining region 200. As shown in FIG. 1 , the support portion 12 is arranged so as to be fitted into the joining region 200. The recessed side surface that faces the support portion 12 is also referred to as the "opposing side surface 201" below.

[0012] The support part 12 of the tip member 10 is arranged in the joining region 200 so that the protrusion 11 protrudes from the first end 21 of the base material 20. More specifically, a first side surface 121 of the support part 12 of the tip member 10 abuts against an opposing side surface 201 exposed in the joining region 200 of the base material 20. A convex part that protrudes in the thickness direction D2 is formed on one of the first side surface 121 and the opposing side surface 201, and a concave part that fits with the convex part is formed on the other of the first side surface 121 and the opposing side surface 201.

[0013] 1 exemplarily illustrates a configuration in which a convex portion 210 is formed on the opposing side surface 201 and a concave portion 110 is formed on the first side surface 121. Note that a convex portion may be formed on the first side surface 121 and a concave portion may be formed on the opposing side surface 201. In the configuration illustrated in FIG. 1 , the abutment surface between the convex portion and the concave portion formed at the interface between the first side surface 121 and the opposing side surface 201 is rectangular in cross section along the axial direction D1 and is composed of sides parallel to and perpendicular to the axial direction D1.

[0014] Of the multiple side surfaces of the support portion 12 parallel to the axial direction D1, only the first side surface 121 abuts against the base material 20. In addition, the end face of the support portion 12 facing in the opposite direction to the protruding direction of the protrusion 11 abuts against the end face of the base material 20 exposed in the joining region 200 (hereinafter also referred to as the "opposing end face 202"). The second side surface 122 opposing the first side surface 121 of the support portion 12 is continuous with the side surface of the base material 20 without any step.

[0015] The materials of the tip member 10 and the base material 20 may be selected so that the conductivity of the tip member 10 is equal to or higher than that of the base material 20. By selecting the materials of the tip member 10 and the base material 20 in this manner, the electrical resistance of the probe 1 can be reduced. For example, the material of the tip member 10 may be rhodium (Rh), platinum (Pt), or other precious metals. The material of the base material 20 may be nickel (Ni), nickel alloy, gold (Au), silver (Ag), copper (Cu), palladium (Pd), palladium alloy, rhodium (Rh), rhodium alloy, or other precious metals. The tip member 10 and the base material 20 may be joined with an adhesive such as gold (Au).

[0016] The probe 1 shown in FIG. 1 is used in, for example, the electrical connecting device 100 shown in FIG. 3. In the electrical connecting device 100, the probe 1 is held by a probe head 120. Specifically, a plurality of probes 1 are held in the probe head 120 by being successively inserted into guide holes in a first guide plate 1201, a second guide plate 1202, and a third guide plate 1203 included in the probe head 120. Hereinafter, the first guide plate 1201, the second guide plate 1202, and the third guide plate 1203 will be referred to as guide plates unless otherwise specified. The probe head 120 has a configuration in which the first guide plate 1201, the second guide plate 1202, and the third guide plate 1203 are arranged as a plurality of guide plates, spaced apart from each other in the plane normal direction (Z direction) of the main surfaces of the guide plates. In the probe head 120, a spacer 1204 is disposed between the outer edge region of the first guide plate 1201 and the outer edge region of the third guide plate 1203 to form a hollow region 1205 between the first guide plate 1201 and the second guide plate 1202. The second guide plate 1202 is disposed on the side of the hollow region 1205 closer to the third guide plate 1203. The material of the probe head 120 is, for example, ceramic.

[0017] When inspecting the object under test 4, the electrical connecting device 100 moves relative to the object under test 4 in the Z direction, and the tip member 10 of the probe 1 comes into contact with the object under test 4. Fig. 3 shows a state in which the probe 1 and the object under test 4 are spaced apart. The second end 22 of the base material 20 comes into contact with a land 131 of the substrate 130. The land 131 is electrically connected to an inspection device such as an IC tester (not shown). The protrusion 11 of the probe 1 comes into contact with the object under test 4, thereby electrically connecting the object under test 4 and the inspection device.

[0018] As shown in FIG. 3 , for guide holes through which the same probe 1 passes, the positions of the guide holes in the first guide plate 1201 relative to the guide holes in the second guide plate 1202 are offset in the −X direction parallel to the main surface of the second guide plate 1202. FIG. 3 is a side view viewed from the Y direction, which is orthogonal to both the X and Z directions. Hereinafter, the offset arrangement of the guide holes will be referred to as the “offset arrangement.” The direction in which the guide holes are offset will also be referred to as the “offset direction.” In FIG. 3 , the offset direction is the −X direction. Due to the offset arrangement, the base material 20 of the probe 1 is curved inside the probe head 120. That is, in the hollow region 1205 between the first guide plate 1201 and the second guide plate 1202, the base material 20 is curved due to elastic deformation. The positions of the guide holes in the second guide plate 1202 and the third guide plate 1203 coincide when viewed from the Z direction.

[0019] Because the guide holes of the first guide plate 1201 and the second guide plate 1202 are offset, when the probe 1 comes into contact with the test object 4, the probe 1 buckles in the hollow region 1205. That is, when the probe 1 is in contact with the test object 4, the probe 1 is further bent by flexural deformation from the curved shape in the non-contact state in which the probe 1 is not in contact with the test object 4. As the probe 1 further bends, it comes into contact with the test object 4 with a predetermined pressure. Therefore, the offset arrangement allows the electrical characteristics of the test object 4 to be stably measured using the probe 1. When the probe 1 is in a non-contact state, it has elasticity that allows it to return to the shape it had before coming into contact with the test object 4.

[0020] During inspection of the test object 4, the protrusion 11 of the tip member 10 protruding from the first end 21 of the base material 20 comes into contact with the electrode 40 arranged on the test object 4, as shown in FIG. 4 . After the protrusion 11 comes into contact with the electrode 40, the position of the protrusion 11 is displaced in a direction parallel to the surface of the electrode 40 due to the pressure that presses the probe 1 against the test object 4. On the other hand, after the inspection of the test object 4 is completed, the position of the protrusion 11 displaces in the opposite direction from the start of the inspection while in contact with the test object 4 until it goes from a contact state to a non-contact state. The direction in which the position of the protrusion 11 displaces while in contact with the test object 4 is referred to as the "scrubbing direction DS" as shown in FIG. 4 . The scrubbing direction DS and the offset direction are the same. In other words, the scrubbing direction DS is the direction in which the probe 1 can be bent.

[0021] As already explained, the tip member 10 and the base material 20 are joined together with the support part 12 and the base material 20 overlapping in the direction in which the probe 1 can be bent. In other words, as shown in Fig. 4, the support part 12 of the tip member 10 and the base material 20 overlap along the scrubbing direction DS.

[0022] As the tip member 10 moves while in contact with the test object 4, stress is generated in the scrubbing direction DS at the joint between the tip member 10 and the base material 20, making the tip member 10 prone to detachment from the base material 20. Furthermore, when the test object 4 is tested, a load such as pressure along the axial direction D1 is applied to the joint between the tip member 10 and the base material 20. Therefore, as the number of contacts between the test object 4 and the probe 1 increases, the adhesive strength of the bonding material bonding the tip member 10 and the base material 20 decreases, making the tip member 10 prone to detachment from the base material 20. As the number of probes 1 arranged in the electrical connecting device 100 increases, the cost required to replace the probes 1 due to the tip members 10 falling off the base material 20 cannot be ignored.

[0023] In contrast, in the probe 1, the convex portions and concave portions formed at the interface between the first side surface 121 of the support portion 12 and the opposing side surface 201 of the base material 20 are engaged with each other, thereby preventing the tip member 10 from coming off the base material 20. In other words, the protrusion direction of the convex portions and the depression direction of the concave portions are formed in the thickness direction D2, so the concave-convex shape functions as a stopper that prevents the tip member 10 from coming off the base material 20.

[0024] In addition, the uneven shape formed at the interface between the first side surface 121 of the support portion 12 and the opposing side surface 201 of the base material 20 also functions as a regulating portion that regulates positional misalignment between the tip member 10 and the base material 20 when the probe 1 comes into contact with the object to be inspected 4.

[0025] Furthermore, in the probe 1, the support part 12 of the tip member 10 and the base material 20 overlap along the scrub direction DS. In other words, the tip member 10 and the base material 20 are joined together with the support part 12 overlapping in the direction in which the position of the protrusion 11 that contacts the test object 4 is displaced when testing of the test object 4 begins. Therefore, the protrusion direction of the convex part formed at the interface between the first side surface 121 and the opposing side surface 201 is the direction in which the position of the protrusion 11 is displaced. For this reason, even if stress in the scrub direction DS occurs at the joint between the tip member 10 and the base material 20, the tip member 10 is unlikely to come off the base material 20.

[0026] As described above, in the probe 1 according to the first embodiment, the tip member 10 and the base material 20 are joined at the interface between the first side surface 121 of the support portion 12 and the opposing side surface 201 of the base material 20 by fitting a recess into a protrusion that protrudes in the thickness direction D2 perpendicular to the axial direction D1. Therefore, the probe 1 can prevent the tip member 10 joined to one end of the base material 20 from coming off the base material 20.

[0027] The support part 12 is joined to the base material 20 only at the first side surface 121 in the thickness direction D2. Therefore, compared to a configuration in which the tip member 10 is joined to the base material 20 at two side surfaces so as to be sandwiched between the base material 20, for example, the joining area between the support part 12 and the base material 20 along the thickness direction D2 can be made larger. In other words, the area of ​​the support part 12 that joins to the opposing end surface 202 of the base material 20 can be made larger. This makes it possible to reduce the electrical resistance at the joining surface between the support part 12 and the base material 20.

[0028] 2, the first end 21 of the base material 20 overlapping the support portion 12 as viewed in the thickness direction D2 and the support portion 12 may have a tapered shape that gradually widens in width along the axial direction D1 from the first end 21 as viewed in the thickness direction D2. By making the support portion 12 and the first end 21 tapered, it becomes easier to insert the probe 1 into the guide hole of the guide plate when assembling the electrical connecting device 100.

[0029] 5, the contact surfaces of the convex portion and the concave portion may have a tapered shape formed by sides that diagonally intersect with the axial direction D1 in a cross section along the axial direction D1. In other words, even if the contact surfaces of the convex portion and the concave portion have a shape other than rectangular, the contact surfaces of the convex portion and the concave portion in the thickness direction D2 can be prevented from coming off the tip member 10 from the base material 20.

[0030] In addition, although the above example shows a case where one pair of convex portions and concave portions is formed at the interface between the first side surface 121 of the support portion 12 and the opposing side surface 201 of the base material 20, multiple convex portions and multiple concave portions mating with the respective convex portions may be formed at the interface between the first side surface 121 and the opposing side surface 201. Forming multiple pairs of convex portions and concave portions can further prevent the tip member 10 from coming off the base material 20. The pairs of convex portions and concave portions may be arranged in the axial direction D1. For example, as shown in FIG. 6A , multiple convex portions and concave portions with rectangular contact surfaces may be formed at the interface between the first side surface 121 and the opposing side surface 201. Alternatively, as shown in FIG. 6B , multiple convex portions and concave portions with tapered contact surfaces may be formed at the interface between the first side surface 121 and the opposing side surface 201.

[0031] 5, 6A, and 6B show a configuration in which a convex portion 210 is formed on the opposing side surface 201 and a concave portion 110 is formed on the first side surface 121, but a convex portion may be formed on the first side surface 121 and a concave portion may be formed on the opposing side surface 201. Alternatively, a convex portion and a concave portion may be formed on the opposing side surface 201, and a concave portion and a convex portion may be formed on the first side surface 121 that mate with the convex portion and the concave portion formed on the opposing side surface 201, respectively.

[0032] Second Embodiment As shown in Fig. 7 , in a probe 1 according to a second embodiment, an embedded portion 123 is formed in the support portion 12 of the tip member 10, and an embedded groove 203 is formed in the opposing end surface 202 of the base material 20. The embedded portion 123 extends along the axial direction D1 in the direction opposite to the protruding direction of the protrusion 11. The embedded groove 203 is formed in the opposing end surface 202 of the base material 20 that faces the support portion 12 in the axial direction D1. The embedded portion 123 of the support portion 12 is embedded in the embedded groove 203 of the base material 20. In other respects, the probe 1 according to the second embodiment is similar to the first embodiment shown in Fig. 1 .

[0033] In the probe 1 shown in Fig. 7 , the region of the support part 12 surrounded by the uneven shape of the interface between the first side surface 121 and the opposing side surface 201 and the uneven shape of the interface between the support part 12 and the opposing end face 202 functions as a stopper that prevents the tip member 10 from coming off the base material 20. Therefore, the probe 1 shown in Fig. 7 can further increase the holding strength of the tip member 10 by the base material 20. Furthermore, in the probe 1 shown in Fig. 7 , the embedded part 123 is embedded in the embedding groove 203, which increases the bonding area between the support part 12 and the base material 20. Therefore, the probe 1 shown in Fig. 7 further prevents the tip member 10 from coming off the base material 20 during inspection of the inspection object 4.

[0034] Otherwise, the probe 1 according to the second embodiment is substantially the same as that according to the first embodiment, and therefore, redundant description will be omitted. For example, a convex portion may be formed on the first side surface 121, and a concave portion may be formed on the opposing side surface 201. Furthermore, the abutting surfaces of the convex portion and the concave portion may be tapered, or multiple pairs of convex portions and concave portions may be formed.

[0035] (Third embodiment) As shown in Fig. 8, the probe 1 according to the third embodiment includes a transmission member 30 arranged on a side surface of the base material 20 extending in the axial direction D1 from the end of the joining region 200. The transmission member 30 may be made of a material with lower electrical resistance than the base material 20. An end face of the support portion 12 of the tip member 10 facing the axial direction D1 is connected to an end face of the transmission member 30 facing the axial direction. The probe 1 shown in Fig. 8 differs from the first embodiment in that it includes the transmission member 30. In other respects, the probe 1 according to the third embodiment is similar to the first embodiment shown in Fig. 1.

[0036] 8, the electrical resistance of the probe 1 to an electrical signal propagating through the probe 1 can be reduced by arranging a transmission member 30 having a lower electrical resistance than the base material 20 on a side surface of the base material 20. For example, when Ni is used for the base material 20, the electrical resistance of the probe 1 can be reduced by using Au for the transmission member 30.

[0037] Otherwise, the probe 1 according to the third embodiment is substantially the same as that according to the first embodiment, and therefore, redundant description will be omitted. For example, a convex portion may be formed on the first side surface 121, and a concave portion may be formed on the opposing side surface 201. Furthermore, the abutting surfaces of the convex portion and the concave portion may be tapered, or multiple pairs of convex portions and concave portions may be formed.

[0038] <Modifications> As in the modification shown in Fig. 9, a part of the transmission member 30 may extend in the protruding direction of the protruding portion 11 along the axial direction D1 so as to overlap the joining region 200. In the probe 1 shown in Fig. 9, a part of the support portion 12 of the tip member 10 is sandwiched between the transmission member 30 and the base material 20. In other words, a part of the support portion 12 is arranged closer to the central axis of the probe 1 than the transmission member 30. According to the probe 1 shown in Fig. 9, the contact area between the tip member 10 and the transmission member 30 is larger than that of the probe 1 shown in Fig. 8, and therefore the electrical resistance of the probe 1 can be reduced.

[0039] 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.

[0040] For example, as shown in Fig. 10, the end face of the protrusion 11 that comes into contact with the test object may be curved. By making the end face of the protrusion 11 a curved face, it is possible to prevent the test object from being damaged due to the protrusion 11 coming into contact with the test object.

[0041] In the above description, the protruding portion 11 of the tip member 10 protrudes from the first end 21 of the base material 20, and the protruding portion 11 comes into contact with the inspection object 4. However, both the tip member 10 and the base material 20 may come into contact with the inspection object 4.

[0042] Thus, it goes without saying that the present invention includes various embodiments that are not described above.

[0043] REFERENCE SIGNS LIST 1 probe 10 tip member 11 protrusion 12 support portion 20 base material 21 first end portion 22 second end portion 30 transmission member 110 recess 121 first side surface 122 second side surface 123 embedded portion 200 bonding region 201 opposing side surface 202 opposing end surface 203 embedded groove 210 protrusion

Claims

1. A probe used for testing electrical characteristics of an object to be tested, comprising: a tip member having a support portion and contacting the object to be tested; and a base material having a bonding region formed by recessing a part of its side in a thickness direction perpendicular to the axial direction within a certain range from one end along the axial direction, wherein a first side of the support portion of the tip member and the recessed side exposed in the bonding region of the base material come into contact with each other, thereby bonding the support portion to the base material, and a convex portion protruding in the thickness direction is formed on one of the first side and the recessed side, and a concave portion mating with the convex portion is formed on the other of the first side and the recessed side.

2. The probe according to claim 1, wherein the tip member has a protruding portion connected to the support portion and in contact with the object to be inspected, an embedded portion extending in a direction opposite to the protruding direction of the protruding portion is formed on the support portion of the tip member, an embedded groove is formed on an opposing end face of the base material that faces the support portion in the axial direction, and the embedded portion is embedded in the embedded groove.

3. The probe according to claim 1, further comprising a transmission member made of a material having a lower electrical resistance than the base material and arranged on a side of the base material extending in the axial direction from an end of the joint region, the transmission member being connected to the support portion of the tip member.

4. The probe according to claim 3, wherein a portion of the transmission member extends along the axial direction so as to overlap with the joint region, and a portion of the support portion of the tip member is sandwiched between the extended portion of the transmission member and the base material.

5. The probe according to claim 1, wherein a second side surface of said support portion opposite said first side surface is continuous with said base material without any step.

6. The probe according to any one of claims 1 to 5, wherein a plurality of said protrusions and a plurality of said recesses each engaging with said protrusions are formed on said first side surface and said recessed side surface.

7. A probe according to any one of claims 1 to 5, wherein the contact surfaces between said convex portion and said concave portion have a rectangular shape in a cross section along said axial direction, the rectangular shape being defined by sides parallel and perpendicular to said axial direction.

8. A probe according to any one of claims 1 to 5, wherein the contact surfaces between said convex portion and said concave portion have a tapered shape defined by sides that intersect obliquely with said axial direction in a cross section along said axial direction.

9. A probe as claimed in any one of claims 1 to 5, wherein the tip member and the base material are joined with an overlap between the support portion and the base material in a direction in which the tip member that comes into contact with the test object at the start of testing the test object is displaced, and the direction in which the convex portion protrudes is the direction of the displacement.

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