Probe and electrical connection device

Abstract

This probe includes a structure in which a tip portion, a curved portion, and a base end portion are connected in sequence in the axial direction. A first member and a second member having a lower hardness than the first member coexist in a cross section perpendicular to the axial direction. The curved portion includes a low-hardness section where the area ratio of the second member to the first member in the cross section is relatively higher than that of other regions. The cross-sectional area is constant from the tip portion to the base end portion.

Description

Probes and Electrical Connection Devices

[0001] The present invention relates to a probe and an electrical connecting device used for testing 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 is brought into contact with an electrode pad 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] In testing an object under test, after the probes are brought into contact with the electrode pads, the electrical connection device is brought closer to the object under test to bend the probes through elastic deformation (hereinafter also referred to as "overdrive"). By bending the probes through overdrive, the elastic force of the probes allows the probes to stably contact the electrode pads and lands.

[0004] JP 2018-91870 A

[0005] In order to bend the probe, a probe is used that has a narrowed portion (hereinafter also referred to as a "constricted portion") formed in a portion that is narrower in diameter than the other portions. However, the cross-sectional area of ​​the constricted portion of the probe is reduced. Therefore, forming a constricted portion in the probe reduces the amount of current that can be passed through the probe (hereinafter also referred to as the "allowable current value"). The present invention aims to provide a probe and an electrical connecting device that have a structure that allows the probe to bend easily without reducing the allowable current value.

[0006] A probe according to one aspect of the present invention includes a structure in which a tip portion, a curved portion, and a base portion that are brought into contact with an object to be tested are connected in this order in the axial direction. In a cross section perpendicular to the axial direction, a first member and a second member having a lower hardness than the first member are mixed. The curved portion includes a low-hardness portion in which the area ratio of the second member to the first member in the cross section is relatively higher than in other regions. The cross-sectional area is constant from the tip portion to the base portion.

[0007] According to the present invention, it is possible to provide a probe and an electrical connecting device having a structure that is easily bent without reducing the allowable current value.

[0008] FIG. 1 is a schematic diagram showing the configuration of a probe according to an embodiment of the present invention. FIG. 2A is a schematic cross-sectional view taken along the IIA-IIA direction in FIG. 1. FIG. 2B is a schematic cross-sectional view taken along the IIB-IIB direction in FIG. 1. FIG. 2C is a schematic cross-sectional view taken along the IIC-IIC direction in FIG. 1. FIG. 3 is a schematic exploded view of the probe of FIG. 1. FIG. 4 is a schematic diagram showing the configuration of an electrical connecting device having a probe according to an embodiment of the present invention. FIG. 5A is a schematic diagram showing an example of a cross-section of a probe according to a first modified example of an embodiment of the present invention. FIG. 5B is a schematic diagram showing another example of a cross-section of a probe according to the first modified example of an embodiment of the present invention. FIG. 6A is a schematic diagram showing an example of a cross-section of a probe according to a second modified example of an embodiment of the present invention. FIG. 6B is a schematic diagram showing another example of a cross-section of a probe according to the second modified example of an embodiment of the present invention. FIG. 7 is a schematic diagram showing an example of a cross-section of a probe according to a third modified example of an embodiment of the present invention. FIG. 8 is a schematic diagram showing an example of a cross-section of a probe according to a fourth modified example of an embodiment of the present invention.

[0009] 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 each other. The embodiments shown below exemplify devices and methods for embodying the technical ideas of the present invention, and the embodiments of the present invention are not limited to the following in terms of the materials, shapes, structures, arrangements, and manufacturing methods of the components.

[0010] The probe 10 according to the embodiment shown in FIG. 1 is used to test electrical characteristics of a test object. The probe 10 has a columnar shape including a structure in which a tip portion 11, a curved portion 12, and a base portion 13 are connected in axial order. The tip portion 11 is brought into contact with a test object during testing. FIG. 2A shows a cross-sectional view of the tip portion 11 of the probe 10 taken along the IIA-IIA direction. FIG. 2B shows a cross-sectional view of the curved portion 12 of the probe 10 taken along the IIB-IIB direction. FIG. 2C shows a cross-sectional view of the base portion 13 of the probe 10 taken along the IIC-IIC direction.

[0011] 2A to 2C, a cross section perpendicular to the axial direction (hereinafter simply referred to as a "cross section") includes a mixture of a first member 110 and a second member 120. The second member 120 is made of a material having a lower hardness than the first member 110.

[0012] 2A and 2C , the first member 110 and the second member 120 are stacked in the cross sections of the distal end portion 11 and the proximal end portion 13. More specifically, the second member 120 is sandwiched between the first members 110. In regions other than the curved portion 12 of the probe 10, the second member 120 may be sandwiched between the first members 110 across the entire width.

[0013] 1, the axial direction in which the probe 10 extends is also referred to as the Z direction, the thickness direction in which the first member 110 and the second member 120 are stacked is also referred to as the Y direction, and the width direction perpendicular to both the Z direction and the Y direction is also referred to as the X direction. In addition, the surface facing the Y direction is also referred to as the top surface, and the surface facing opposite the top surface is also referred to as the bottom surface.

[0014] The probe 10 has a rectangular cross section. The probe 10 has a first side surface 101 and a second side surface 102 that extend in the axial direction and face in opposite directions in the thickness direction (Y direction). The first side surface 101 is the top surface of the probe 10, and the second side surface 102 is the bottom surface of the probe 10. The probe 10 also has a third side surface 103 and a fourth side surface 104 that extend in the axial direction and face in opposite directions in the width direction (X direction) and connect the first side surface 101 and the second side surface 102. For example, as shown in FIG. 1 , the cross section of the probe 10 may have a larger size in the width direction than in the thickness direction.

[0015] In the cross section shown in FIG. 2B , the area ratio of the second member 120 to the first member 110 is relatively higher than in the cross sections shown in FIGS. 2A and 2C . Because the second member 120 is made of a material with a lower hardness than the first member 110, the bending portion 12, where the area ratio of the second member 120 is relatively high, has lower rigidity than the distal end portion 11 and the proximal end portion 13, where the area ratio of the second member 120 is relatively low. Hereinafter, a region in the cross section where the area ratio of the second member 120 to the first member 110 is relatively higher than other regions will be referred to as a "low hardness portion." The entire bending portion 12 may be a low hardness portion. The other regions of the probe 10 excluding the low hardness portion will be referred to as a "high hardness portion." The high hardness portion is a portion with a relatively higher hardness than the low hardness portion. The distal end portion 11 and the proximal end portion 13 of the probe 10 are high hardness portions.

[0016] As described above, in the probe 10, the high hardness portion has higher rigidity than the low hardness portion. The cross-sectional area is constant from the distal end 11, which is one end of the probe 10, to the proximal end 13, which is the other end. Therefore, when the probe 10 elastically deforms, the bending portion 12 is more likely to bend than the distal end 11 and the proximal end 13. Therefore, the probe 10 bends at the bending portion 12 by overdrive, even without providing a constriction in the bending portion 12 for bending. In this way, the probe 10 has a structure that is easily bendable without reducing the allowable current value by providing a constriction.

[0017] The second member 120 may be made of a material having higher conductivity than the first member 110. By using a highly conductive material for the second member 120, the allowable current value of the probe 10 can be further increased. For example, the first member 110 may be made of nickel (Ni) or a Ni alloy, and the second member 120 may be made of gold (Au), silver (Ag), copper (Cu), or the like.

[0018] Fig. 3 shows the structure of the probe 10 disassembled into a first member 110 and a second member 120. The probe 10 shown in Fig. 3 has a structure in which a second part 121 made of the second member 120 is sandwiched in the Y direction between a first part 111 made of the first member 110 and a third part 113. Protrusions that protrude parallel to the Y direction are formed on the upper and lower surfaces of the second part 121 at the curved portion 12. Through holes into which the protrusions of the second part 121 are fitted are formed in the first part 111 and the third part 113.

[0019] In the probe 10 shown in FIG. 3 , in which the first component 111, the second component 121, and the third component 113 are stacked, the second component 120 is formed in a cross shape in the cross section of the bending portion 12, as shown in FIG. 2B . That is, the second component 120, whose ends are exposed on the third side surface 103 and the fourth side surface 104, includes an extending portion that extends from the center to both the first side surface 101 and the second side surface 102 in the cross section of the low hardness portion. In this way, the extending portion extending in the thickness direction of the second component 120 divides the first component 110 into two regions in the X direction. Furthermore, in the cross section of the low hardness portion, the extending portion of the second component 120 and the first component 110 intersect perpendicularly.

[0020] On the other hand, in the cross section of the distal end 11 and proximal end 13 of the high hardness portion, a flat plate-shaped first member 110, a second member 120, and another first member 110 are laminated in this order, as shown in Figures 2A and 2C. As shown in Figure 3, the probe 10 may be formed so that the first member 110 and the second member 120 are each continuous throughout the entire probe 10, from the distal end 11 through the curved portion 12 to the proximal end 13.

[0021] The probe 10 is used in, for example, an electrical connecting device 100 shown in FIG. 4 . In the electrical connecting device 100, the probe 10 is held by a probe head 20. The probe head 20 is configured such that a first guide plate 21, a second guide plate 22, and a third guide plate 23 are arranged in the axial direction of the probe 10. The first guide plate 21 is also referred to as a top guide plate. The second guide plate 22 is also referred to as a middle guide plate. The third guide plate 23 is also referred to as a bottom guide plate. A spacer 25 is arranged between the first guide plate 21 and the second guide plate 22, thereby forming a hollow region 200 inside the probe head 20.

[0022] 4 , a plurality of probes 10 are held in the probe head 20 by being inserted into guide holes in the first guide plate 21, the second guide plate 22, and the third guide plate 23. The tip end 11 of the probe 10 passes through the guide holes in the second guide plate 22 and the third guide plate 23. The base end 13 of the probe 10 passes through the guide hole in the first guide plate 21. Hereinafter, the first guide plate 21, the second guide plate 22, and the third guide plate 23 will be referred to as guide plates unless otherwise specified.

[0023] When testing the test object 2, the tip end 11 of the probe 10 comes into contact with an electrode pad (not shown) of the test object 2. The base end 13 of the probe 10 comes into contact with a land 31 of a substrate 30 stacked on the probe head 20. The land 31 is electrically connected to a testing device such as an IC tester (not shown).

[0024] In the electrical connecting device 100 shown in FIG. 4 , for guide holes through which the same probe 10 passes, the positions of the guide holes in the first guide plate 21 and the third guide plate 23 are offset in a direction F parallel to the main surface of the first guide plate 21. Hereinafter, the offset arrangement of the guide holes will be referred to as the "offset arrangement." The direction F in which the guide holes are offset will also be referred to as the "offset direction." Due to the offset arrangement, the probe 10 is curved in the hollow region 200 between the first guide plate 21 and the second guide plate 22. That is, the probe 10 is curved due to elastic deformation in the hollow region 200 between the first guide plate 21 and the second guide plate 22. For example, the offset direction is the thickness direction of the probe 10. The positions of the guide holes in the second guide plate 22 and the third guide plate 23 are aligned when viewed from the surface normal of the guide plates.

[0025] Because the guide holes in the first guide plate 21 and the third guide plate 23 are offset, the probe 10 buckles in the hollow region 200 due to overdrive after the tip 11 of the probe 10 comes into contact with the test object 2. That is, when the probe 10 is in contact with the test object 2 (contact state), the probe 10 further bends due to flexural deformation from the curved shape when the probe 10 is not in contact with the test object 2 (non-contact state). This further bending of the probe 10 brings the probe 10 into contact with the test object 2 with a predetermined pressing force. Therefore, the offset arrangement allows the probe 10 to stably measure the electrical characteristics of the test object 2. When the probe 10 is in a non-contact state, it has the elasticity to return to the shape it had before coming into contact with the test object 2.

[0026] The tip end 11 and base end 13 of the probe 10 are high hardness portions. Therefore, even when the probe 10 is bent by overdrive, the tip end 11 moves linearly along the central axes of the guide holes in the second guide plate 22 and the third guide plate 23. Similarly, the base end 13 moves linearly along the central axis of the guide hole in the first guide plate 21. Therefore, damage to the probe 10 due to contact between the probe 10 and the side surfaces of the guide holes in the guide plates is suppressed.

[0027] As described above, the bending section 12 of the probe 10 according to the embodiment of the present invention includes a low-hardness portion in which the area ratio of the second member 120 to the first member 110 in the cross section is relatively higher than in other regions. Therefore, the probe 10 has a structure that allows it to bend easily without reducing the allowable current value.

[0028] It is preferable that the first members 110 are arranged at the four corners of the cross section of the low hardness portion. By arranging the first members 110 having high hardness at the four corners of the cross section of the probe 10, it is possible to prevent the second member 120 having low hardness from being damaged when the probe 10 is transported by being held with tweezers or the like during the manufacturing process of the probe 10 or after completion.

[0029] In the above example, the second member 120 is formed in a cross shape in the cross section of the low hardness portion. However, the arrangement of the first member 110 and the second member 120 in the cross section of the low hardness portion is not limited to the above.

[0030] 5A and 5B, the extending portion of the second member 120 may reach either the first side surface 101 or the second side surface 102. In the cross section shown in Fig. 5A, the extending portion of the second member 120 reaches only the first side surface 101. In the cross section shown in Fig. 5B, the extending portion of the second member 120 reaches only the second side surface 102. In this manner, the extending portion of the second member 120 may reach at least either the first side surface 101 or the second side surface 102.

[0031] 6A and 6B, the extending portion of the second member 120 may reach the first side surface 101 and the second side surface 102, respectively, and the second member 120 may be exposed on at least one of the third side surface 103 and the fourth side surface 104. In the cross section shown in FIG. 6A, the second member 120 is exposed only on the third side surface 103. In the cross section shown in FIG. 6B, the second member 120 is exposed only on the fourth side surface 104.

[0032] Alternatively, as shown in Fig. 7, the first extending portion that reaches the first side surface 101 of the second member 120 and the second extending portion that reaches the second side surface 102 may be arranged so as not to overlap when viewed in the thickness direction. Also, as shown in Fig. 8, the cross section of the low hardness portion may include multiple extending portions of the second member 120. In the cross section shown in Fig. 8, the first member 110 is divided into multiple regions by the multiple extending portions of the second member 120.

[0033] In the above example, the boundary between the first member 110 and the second member 120 is perpendicular to the X direction and the Y direction in the cross section, but the boundary between the first member 110 and the second member 120 may be oblique to the X direction or the Y direction. Also, in the above example, the second member 120 is exposed on at least one of the third side surface 103 and the fourth side surface 104, but the second member 120 does not have to be exposed on either the third side surface 103 or the fourth side surface 104. Alternatively, the second member 120 may be divided into a plurality of regions in the cross section.

[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 has been given of a case where the entire bending portion 12 is a low-hardness portion, only a partial region of the bending portion 12 may be a low-hardness portion. This allows bending a desired region of the probe 10. Furthermore, although the above description has been given of a case where the entire distal end portion 11 and the proximal end portion 13 are formed of a laminated structure of the first member 110 and the second member 120, the distal end portion 11 and the proximal end portion 13 may be formed of only the first member 110.

[0036] If the curved portion of the probe 10 has a lower hardness than the other portions, the arrangement of the first member 110 and the second member 120 may be reversed. For example, the cross-shaped Au material region and the other Ni material regions in the structure shown in FIG. 2B may be reversed.

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

[0038] REFERENCE SIGNS LIST 10 probe 11 distal end portion 12 bending portion 13 proximal end portion 101 first side surface 102 second side surface 103 third side surface 104 fourth side surface 110 first member 111 first part 113 third part 120 second member 121 second part

Claims

1. A probe used to test the electrical characteristics of an object to be tested, comprising a structure in which a tip portion, a curved portion, and a base portion that come into contact with the object to be tested are connected in that order in the axial direction, a first member and a second member that is lower in hardness than the first member are mixed in a cross section perpendicular to the axial direction, the curved portion includes a low-hardness portion in which the area ratio of the second member to the first member in the cross section is relatively higher than in other regions, and the area of the cross section is constant from the tip portion to the base portion.

2. The probe of claim 1, wherein said second member is more conductive than said first member.

3. The probe according to claim 1, wherein the distal end and the proximal end are included in the other region.

4. The probe according to claim 1, wherein the entire curved portion is the low hardness portion.

5. The probe according to claim 1, wherein the cross section is rectangular, and the probe has a first side surface and a second side surface extending in the axial direction and facing in opposite directions with respect to a thickness direction perpendicular to the axial direction, and a third side surface and a fourth side surface extending in the axial direction and facing in opposite directions with respect to a width direction perpendicular to the axial direction and the thickness direction, and connecting the first side surface and the second side surface.

6. A probe according to claim 5, wherein in the cross section of the low hardness portion, the first member is divided into a plurality of regions by an extension portion of the second member extending from a central portion in the thickness direction.

7. The probe according to claim 6, wherein the extending portion of the second member and the first member intersect perpendicularly in the cross section of the low hardness portion.

8. The probe according to claim 6, wherein said extending portion reaches at least one of said first side surface and said second side surface.

9. The probe according to claim 6, wherein said extending portions reach said first side and said second side, respectively, and said second member is exposed on at least one of said third side and said fourth side.

10. The probe according to claim 6, wherein the first extension portion reaching the first side surface and the second extension portion reaching the second side surface do not overlap when viewed in the thickness direction.

11. The probe of claim 6, wherein said cross section of said low hardness portion includes a plurality of said extensions.

12. The probe according to claim 5, wherein the first members are arranged at four corners of the cross section of the low hardness portion.

13. The probe according to claim 5, wherein in the other region excluding the low hardness portion, the second member is sandwiched by the first member along the thickness direction over the entire width direction.

14. An electrical connection device comprising: a probe according to any one of claims 1 to 13; a probe head for holding the probe; and a substrate stacked on the probe head, wherein the base end of the probe contacts a land arranged on the substrate.

15. The electrical connection device according to claim 14, wherein the probe head includes a first guide plate and a second guide plate each having a guide hole formed therein through which the probe passes, the positions of the guide holes in the first guide plate and the second guide plate are offset in a direction parallel to the main surface of the first guide plate, and the probe is curved in a hollow region between the first guide plate and the second guide plate.

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