Probe

Abstract

This probe (10) comprises: a distal end part (11); a spring part (12) in which a plurality of coil spring parts (121) are connected along the axial direction via non-elastic connection parts (122); a proximal end part (13); and a current path member (114A) that is disposed inside the spring part (12) and electrically connects the distal end part (11) and the proximal end part (13). The probe (10) has a rectangular shape having four side surfaces when viewed in the axial direction, and a recessed section into which an end section of the current path member (114A) is inserted when the spring part (12) contracts in the axial direction is formed in at least one among the distal end part (11), the proximal end part (13), and the connection parts (122).

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 also 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] JP 2018-4260 A

[0004] To accurately test the electrical characteristics of a test object, a stable electrical connection between the test object and the land must be established via a probe. For this purpose, it is effective to use a probe that includes a spiral coil spring that provides axial elasticity. However, since current flows through the coil spring, the current path of the probe becomes long. As a result, the electrical resistance of the probe increases, reducing the accuracy of measuring electrical characteristics. Furthermore, buckling of the coil spring can occur.

[0005] In view of the above problems, an object of the present invention is to provide a probe that has a coil spring portion and can suppress an increase in electrical resistance and the occurrence of buckling.

[0006] A probe according to one aspect of the present invention includes a tip end, a spring portion formed by connecting a plurality of coil spring portions along an axial direction via inelastic connecting portions, a base end, and a current path member disposed inside the spring portion and electrically connecting the tip end and the base end. The probe has a rectangular shape having four side faces when viewed from the axial direction, and a recess into which an end of the current path member is inserted when the spring portion contracts in the axial direction is formed in at least one of the tip end, the base end, and the connecting portion.

[0007] According to the present invention, it is possible to provide a probe that has a coil spring portion and can suppress an increase in electrical resistance and the occurrence of buckling.

[0008] FIG. 1 is a schematic side view showing the configuration of a probe according to the first embodiment. FIG. 2 is a schematic plan view showing the configuration of the probe according to the first embodiment. FIG. 3 is a schematic view showing a first component constituting the probe shown in FIG. 1. FIG. 4 is a schematic view showing a second component constituting the probe shown in FIG. 1. FIG. 5 is a schematic view showing a third component constituting the probe shown in FIG. 1. FIG. 6 is a schematic view showing the configuration of a coil spring portion of the probe according to the first embodiment. FIG. 7 is a schematic perspective view showing the coil spring portion of the probe according to the first embodiment. FIG. 8 is a schematic view showing a fourth component including a current path member constituting the probe shown in FIG. 1. FIG. 9 is a schematic view showing the connection between the tip portion of the probe shown in FIG. 1 and the current path member. FIG. 10 is a schematic view showing the connection between the coupling portion of the probe shown in FIG. 1 and the current path member. FIG. 11 is a schematic view showing the shape of each line of the coil spring portion of the probe according to the first embodiment. FIG. 12 is a schematic side view showing the configuration of a probe according to a second embodiment. FIG. 13 is a schematic view showing the first component constituting the probe shown in FIG. 12. FIG. 14 is a schematic diagram showing a second component constituting the probe shown in FIG. 12 . FIG. 15 is a schematic diagram showing a third component constituting the probe shown in FIG. 12 . FIG. 16 is a schematic diagram showing a current path member constituting the probe shown in FIG. 12 . FIG. 17 is a schematic diagram showing a method for connecting the current path members of the probe shown in FIG. 16 . FIG. 18 is a schematic side view showing the configuration of a probe according to a modified example of the second embodiment. FIG. 19 is a schematic diagram showing a first component constituting the probe shown in FIG. 18 . FIG. 20 is a schematic diagram showing a second component constituting the probe shown in FIG. 18 . FIG. 21 is a schematic diagram showing a third component constituting the probe shown in FIG. 18 . FIG. 22 is a schematic diagram showing a method for connecting the current path members of the probe shown in FIG. 18 . FIG. 23 is a schematic cross-sectional view showing an example of an opening shape of a coupling portion of a probe according to another embodiment. FIG. 24 is a schematic cross-sectional view showing another example of an opening shape of a coupling portion of a probe according to another embodiment.

[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. 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.

[0010] First Embodiment A probe 10 according to a first embodiment shown in FIG. 1 is used to test electrical characteristics of a test object. A tip portion 11, which contacts the test object, is disposed at one axial end of the probe 10, and a base portion 13, which contacts a land, is disposed at the other axial end. In the probe 10, elastic first to fourth coil spring portions 1211 to 1214 are connected along the axial direction between the tip portion 11 and the base portion 13 via inelastic connecting portions 122. Hereinafter, the first to fourth coil spring portions 1211 to 1214 will be referred to as "coil spring portion 121" unless otherwise specified. In the probe 10, a portion located between the tip portion 11 and the base portion 13, including the coil spring portion 121 and the connecting portion 122, will be referred to as "spring portion 12."

[0011] The probe 10 has a columnar shape with a tip end 11 and a base end 13 as its two ends. As shown in Fig. 1, the axial direction of the probe 10 is the Z direction, the left-right direction in Fig. 1 is the X direction, and the depth direction in Fig. 1 is the Y direction. The direction in which the tip end 11 is located as viewed from the base end 13 along the Z direction is referred to as the upper side, and the direction in which the base end 13 is located as viewed from the tip end 11 is referred to as the lower side. The upward facing surface of each part of the probe 10 is referred to as the top surface, the downward facing surface is referred to as the bottom surface, and the surface connecting the top and bottom surfaces is referred to as the side surface.

[0012] As shown in FIG. 2 , the probe 10 has a rectangular shape having four side faces when viewed in the axial direction. A side face when viewed in the Y direction is referred to as a first side face 101, and a side face facing opposite the first side face 101 is referred to as a second side face 102. A side face when viewed in the X direction is referred to as a third side face 103, and a side face facing opposite the third side face 103 is referred to as a fourth side face 104. As will be described later, the coil spring portion 121 of the probe 10 is formed by combining a first component 111, a second component 112, and a third component 113. As shown in FIG. 2 , the first side face 101 is the surface of the first component 111, the second side face 102 is the surface of the third component 113, and the third side face 103 and the fourth side face 104 are the surfaces of the second component 112.

[0013] 1, a first coil spring portion 1211, a second coil spring portion 1212, a third coil spring portion 1213, and a fourth coil spring portion 1214 are connected in this order from the distal end portion 11 to the proximal end portion 13 via connecting portions 122. Although Fig. 1 exemplifies a case in which the number of coil spring portions 121 included in the probe 10 is four, the number of coil spring portions 121 included in the probe 10 can be set arbitrarily.

[0014] Fig. 3 shows a first part 111 constituting the probe 10. Fig. 4 shows a second part 112 constituting the probe 10. Fig. 5 shows a third part 113 constituting the probe 10. The first part 111 and the third part 113 have a structure in which beams extending obliquely with respect to the X direction (hereinafter also referred to as "diagonal beams") are arranged along the Z direction. The second part 112 has a structure in which beams parallel to the Y direction (hereinafter also referred to as "parallel beams") are arranged along the Z direction.

[0015] The coil spring portion 121 of the probe 10 is configured by stacking the third component 113, the second component 112, and the first component 111 in this order along the Y direction. That is, the parallel beams of the second component 112 connect the diagonal beams of the first component 111 and the diagonal beams of the third component 113, thereby configuring the coil spring portion 121.

[0016] FIG. 6 shows the configuration of the coil spring portion 121. The first component 111, which appears on the first side surface 101, includes a diagonal beam extending from the upper left to the lower right of the drawing when viewed in the normal direction of the first side surface 101. The third component 113, which appears on the second side surface 102, includes a diagonal beam extending from the upper right to the lower left of the drawing when viewed in the normal direction of the first side surface 101. In other words, the diagonal beams of the first component 111 and the diagonal beams of the third component 113 are arranged symmetrically with respect to the central axis of the probe 10. In other words, the third component 113 has a mirror image of the first component 111. As shown in FIG. 6, the coil spring portion 121 has a double helix structure. FIG. 7 shows a perspective view of the coil spring portion 121.

[0017] The probe 10 further includes a current path member 114A disposed inside the coil spring portion 121. The current path member 114A is a columnar member having electrical conductivity. The current path member 114A of the probe 10 shown in FIG. 1 bridges between the tip end portion 11 and the connecting portion 122, between the two connecting portions 122, and between the base end portion 13 and the connecting portion 122. The current path member 114A is electrically conductive, and the tip end portion 11 and the base end portion 13 are electrically connected via the current path member 114A and the connecting portion 122.

[0018] For example, the current path member 114A bridges the tip portion 11 with a connecting portion 122 that connects to one end of a coil spring portion 121 that has the other end connected to the tip portion 11. This electrically connects the tip portion 11 with the connecting portion 122 that is closest to the tip portion 11.

[0019] Further, the current path member 114A bridges the base end 13 with a connecting portion 122 that connects to one end of the coil spring portion 121, the other end of which is connected to the base end 13. This electrically connects the base end 13 with the connecting portion 122 that is closest to the base end 13.

[0020] Furthermore, the current path member 114A bridges two connecting portions 122 that are respectively connected to both ends of one coil spring portion, thereby electrically connecting the two connecting portions 122 together.

[0021] 8 shows a fourth component 114 including a current path member 114A. The fourth component 114 has a configuration in which a plurality of current path members 114A extending in the Z direction are arranged along the Z direction. In manufacturing the probe 10, the fourth component 114 is placed before the first component 111 is stacked on the second component 112. This results in the manufacture of the probe 10 in which the current path member 114A is placed inside the spring portion 12.

[0022] 9 , for example, the current path member 114A disposed inside the first coil spring portion 1211 has a first end facing the first opening 110 of a recess formed in the lower surface of the tip portion 11, and a second end connected to the upper surface of the connecting portion 122. When the probe 10 contracts in the axial direction, the first end of the current path member 114A is inserted into the first opening 110, thereby electrically connecting the tip portion 11 and the connecting portion 122. In this way, when the spring portion 12 expands and contracts, the first end of the current path member 114A slides inside the first opening 110.

[0023] 10 , the current path member 114A disposed inside the second coil spring portion 1212 has a first end facing the second opening 120 of the recess formed in the lower surface of one of the connecting portions 122, and a second end connected to the upper surface of the other connecting portion 122. When the probe 10 contracts in the axial direction, the first end of the current path member 114A is inserted into the second opening 120, thereby electrically connecting the two connecting portions 122. In this way, when the spring portion 12 expands and contracts, the first end of the current path member 114A slides inside the second opening 120.

[0024] Similar to the current path member 114A arranged inside the second coil spring portion 1212, the current path member 114A arranged inside the third coil spring portion 1213 also electrically connects the two connecting portions 122. The current path member 114A arranged inside the fourth coil spring portion 1214 has a first end facing the second opening 120 of the recess formed in the lower surface of the connecting portion 122, and a second end connected to the upper surface of the base end portion 13. When the probe 10 contracts in the axial direction, the first end of the current path member 114A is inserted into the second opening 120. This electrically connects the connecting portion 122 and the base end portion 13.

[0025] As described above, when the coil spring portion 121 expands and contracts, the end portion of the current path member 114A slides inside the first opening 110 and the second opening 120. Therefore, even if the probe 10 expands and contracts in the axial direction, the current path member 114A does not bend and become exposed outside the coil spring portion 121.

[0026] The first component 111, the second component 112, the third component 113, and the current path member 114A are made of a conductive material such as a metal material, and are formed, for example, by processing a metal plate. The probe 10 is manufactured by stacking the metal plates in the following order: the third component 113, the second component 112, the current path member 114A, and the first component 111. The diagonal beams of the first component 111 and the third component 113 function as springs, and the diagonal beams of the first component 111 and the third component 113 are connected by the second component 112. In other words, the beams of the first component 111, the second component 112, and the third component 113 are connected to form the wires of the coil spring portion 121.

[0027] The probe 10 is flexible in the axial direction due to the coil spring portion 121 of the spring portion 12. Since the probe 10 itself has elasticity in the axial direction, it is not necessary to hold the probe 10 in a curved state on the probe head, for example.

[0028] Furthermore, in the probe 10, the current path member 114A disposed inside the coil spring portion 121 functions as a current path between the distal end portion 11 and the proximal end portion 13. Therefore, even if the electrical resistance is high due to the long path in the coil spring portion 121, the current path of the probe 10 can be shortened. In other words, the current path member 114A functions as a component that shortens the current path. In this way, the current path member 114A can reduce the electrical resistance of the current path of the probe 10.

[0029] As shown in FIG. 8 , the current path member 114A may be arranged inside the coil spring portion 121 in a curved state. In this case, the curvature directions of the multiple current path members 114A arranged along the axial direction may be different. For example, the curvature directions may be staggered along the axial direction. Furthermore, the first end of the current path member 114A may be rounded. That is, the first end of the current path member 114A may have a tapered or substantially spherical shape. Because the first end is rounded, when the current path member 114A is inserted into the first opening 110, it moves along the inner wall of the first opening 110 and can be easily guided into the first opening 110. Furthermore, because the current path member 114A has such a shape, damage to the first end or the inner wall of the first opening 110 when the first end slides inside the first opening 110 can be suppressed.

[0030] The probe 10 may be made of, for example, 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. The current path member 114A may be made of a material that has lower mechanical strength but higher conductivity than the first component 111, the second component 112, and the third component 113. For example, the first component 111 and the third component 113 may be made of a Ni alloy, and the current path member 114A may be made of gold or copper.

[0031] Note that, when viewed from the first side surface 101 and the second side surface 102, each line of the coil spring portion 121 may not be straight but may include a curved portion. For example, as shown in FIG. 11 , the direction of each line may change midway along the side surface. Each line of the coil spring portion 121 shown in FIG. 11 includes a structure in which a first portion 121A extending at a first angle relative to the axial direction is connected to a second portion 121B extending at a second angle different from the first angle relative to the axial direction. In the example shown in FIG. 11 , the second portion 121B is disposed between the first portion 121A and the first portion 121A. By including a curved portion rather than a simple straight line, the load applied to the probe 10 is more easily transmitted in the axial direction, and the probe 10 is prevented from bending and buckling from the central axis when a pressing force in the axial direction is applied to the probe 10.

[0032] The elastic forces of the multiple coil spring portions 121 included in the probe 10 do not have to be the same. For example, the number of turns of the coil may differ among some of the first coil spring portion 1211, the second coil spring portion 1212, the third coil spring portion 1213, and the fourth coil spring portion 1214. Alternatively, the number of turns may differ among all of the coil spring portions 121. As described above, of two coil spring portions 121 having different elastic forces, one coil spring portion 121 has a different number of turns from the other coil spring portion 121. The number of turns of the coil of the coil spring portion 121 included in the probe 10 can be selected arbitrarily for each individual coil spring portion 121.

[0033] As described above, the probe 10 according to the first embodiment is axially expandable and contractible due to the coil spring portion 121. Furthermore, according to the probe 10 having the current path member 114A, the tip end 11 and the base end 13 are electrically connected via the current path member 114A, which has a shorter current path than the spiral coil spring portion 121. This prevents an increase in the electrical resistance of the probe 10, improving the accuracy of measuring electrical characteristics.

[0034] Furthermore, according to the probe 10 in which the current path member 114A is arranged inside the coil spring portion 121, contact between the coil spring portion 121 and the current path member 114A can suppress buckling of the coil spring portion 121. In the probe 10, the spring portion 12 is formed by stacking a plurality of metal plates, so it is easy to arrange the current path member 114A, which serves as a core rod, inside the spring portion 12.

[0035] Furthermore, according to the probe 10, when the spring portion 12 expands or contracts, the end of the current path member 114A slides inside the first opening 110 and the second opening 120. Therefore, even if the probe 10 expands or contracts in the axial direction, the current path member 114A does not bend and is not exposed to the outside of the coil spring portion 121, allowing for stable operation.

[0036] Second Embodiment As shown in FIG. 12 , in a probe 10 according to a second embodiment, a single current path member 114B that reaches the distal end 11 and the proximal end 13 is disposed inside a coil spring portion 121. In the probe 10 according to the second embodiment, the current path member 114B passes through the inside of a through-hole that axially penetrates a connecting portion 122, bridging the distal end 11 and the proximal end 13. The probe 10 shown in FIG. 12 differs from the probe 10 shown in FIG. 1 in that the distal end 11 and the proximal end 13 are electrically connected by a single current path member 114B, in that the distal end 11 and the proximal end 13 are electrically connected via a plurality of current path members 114A. In other respects, the probe 10 according to the second embodiment is similar to the probe 10 according to the first embodiment shown in FIG. 1 .

[0037] Fig. 13 shows the structure of the first part 111 of the probe 10 shown in Fig. 12. Fig. 14 shows the structure of the second part 112 of the probe 10 shown in Fig. 12. Fig. 15 shows the structure of the third part 113 of the probe 10 shown in Fig. 12. Fig. 16 shows the current path member 114B of the probe 10 shown in Fig. 12.

[0038] The probe 10 shown in Fig. 12 has a configuration in which a coil spring portion 121 is formed by a first component 111, a second component 112, and a third component 113 shown in Fig. 13 to Fig. 15, and a current path member 114B shown in Fig. 16 is disposed inside the coil spring portion 121. The number of coil spring portions 121 included in the probe 10 shown in Fig. 12 is two.

[0039] In the probe 10 according to the second embodiment, as shown in Fig. 14 , a second through hole 152 penetrating in the axial direction is formed in the connecting portion 122. The current path member 114B is disposed inside the second through hole 152 of the coil spring portion 121 and the connecting portion 122, and bridges the distal end portion 11 and the proximal end portion 13. For example, a first end of the current path member 114B is inserted into a first through hole 151 formed in the distal end portion 11 shown in Fig. 14 , and a second end is inserted into a third through hole 153 formed in the proximal end portion 13. When the coil spring portion 121 expands or contracts, the ends of the current path member 114B slide within the first through hole 151 and the third through hole 153.

[0040] 17 , for example, the current path member 114B may be connected to the inner wall surface of the second through hole 152 by a connecting part 115. The connecting part 115 connects the current path member 114B to the coupling part 122 between the first component 111 and the third component 113. The connecting part 115 is disposed between the current path member 114B and a support plate 116 disposed inside the second through hole 152, and joins the support plate 116 and the current path member 114B.

[0041] 12, the electrical resistance of the current path can be further reduced compared to the probe 10 shown in FIG. 1, which uses a plurality of current path members 114A. This increases the allowable value of the current flowing through the probe 10. Otherwise, the second embodiment is substantially similar to the first embodiment, and therefore, redundant description will be omitted.

[0042] <Modification> Fig. 18 shows a probe 10 according to a modification that uses a current path member 114B that is a single columnar member. In the probe 10 shown in Fig. 18, a coupling portion 122 that connects to the tip end portion 11 via a first coil spring portion 1211 and a coupling portion 122 that connects to the base end portion 13 via a second coil spring portion 1212 are arranged opposite to and spaced apart from each other in the axial direction. In other words, the spring portion 12 is divided into two blocks.

[0043] The probe 10 shown in Fig. 18 has a coil spring portion 121 formed by stacking the first component 111 shown in Fig. 19, the second component 112 shown in Fig. 20, and the third component 113 shown in Fig. 21. In the probe 10 shown in Fig. 18, the current path member 114B shown in Fig. 16 is disposed inside the coil spring portion 121.

[0044] 12 , in the probe 10 shown in Fig. 18 , the current path member 114B is disposed inside the coil spring portion 121 and the second through hole 152 of the connecting portion 122, and bridges the tip portion 11 and the base end portion 13. A first end of the current path member 114B is inserted into the first through hole 151 formed in the tip portion 11, and a second end is inserted into the third through hole 153 formed in the base end portion 13.

[0045] The current path member 114B may be connected to the coupling portion 122 between the first component 111 and the third component 113 by a connecting component 115. For example, as shown in Fig. 22 , the connecting component 115 is disposed between the current path member 114B and a support plate 116 disposed inside the second through-hole 152 of the coupling portion 122, and joins the support plate 116 and the current path member 114B.

[0046] 18 shows the probe 10 including two coil spring portions 121, but the number of coil spring portions 121 of the probe 10 is not limited to two. One of the coupling portions 122 electrically connected to the tip end portion 11 via at least one coil spring portion 121 and the other coupling portion 122 electrically connected to the base end portion 13 via at least one coil spring portion 121 may be arranged apart from each other along the axial direction. In other words, the spring portion 12 may be divided into any number of two or more blocks.

[0047] 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.

[0048] For example, in the above example, the first opening 110, the second opening 120, the first through hole 151, the second through hole 152, and the third through hole 153 are formed perpendicular to the upper or lower surface of the distal end portion 11, the proximal end portion 13, or the connecting portion 122. However, the opening shapes of these openings and through holes may be tapered, with the area of ​​the opening gradually narrowing from the outside toward the center.

[0049] 23 and 24 show an example in which the opening shape of second opening 120 in a cross section along the axial direction is tapered. By making the opening shape tapered, the end of current path member 114A can be easily inserted into first opening 110 and second opening 120, and the end of current path member 114B can be easily inserted into first through hole 151 and third through hole 153.

[0050] Thus, it goes without saying that the present invention includes various embodiments not described above.

Claims

1. A probe used for testing the electrical characteristics of an object to be tested, comprising: a tip portion that comes into contact with the object to be tested; a spring portion having one end connected to the tip portion and having a plurality of elastic coil spring portions connected along the axial direction via inelastic connecting portions; a base portion that connects to the other end of the spring portion; and a current path member that is disposed inside the spring portion and electrically connects the tip portion and the base portion, wherein the probe is rectangular in shape with four sides when viewed from the axial direction, and at least one of the tip portion, the base portion, and the connecting portion has a recess into which the end of the current path member is inserted when the spring portion contracts in the axial direction.

2. The probe according to claim 1, wherein the current path member has one end connected to any one of the tip portion, the connecting portion, and the base portion, and the other end facing the recess, and bridges at least one of between the tip portion and the connecting portion, between two of the connecting portions, and between the base portion and the connecting portion.

3. The probe according to claim 1, wherein the single current path member passes through the inside of a through-hole that passes through the connecting portion in the axial direction, bridging the tip portion and the base portion.

4. The probe according to claim 3, further comprising a connection part that connects the inner wall surface of the through-hole and the current path member.

5. The probe according to any one of claims 1 to 4, wherein the spring portion has a structure in which a plurality of metal plates are laminated.

6. A probe according to any one of claims 1 to 4, comprising at least two of said coil spring portions having different elastic forces.

7. The probe according to claim 6, wherein one of the two coil spring portions having different elastic forces has a different number of turns from the other coil spring portion.

8. A probe according to any one of claims 1 to 4, wherein each line of said coil spring portion includes a curved portion when viewed in a direction perpendicular to said axial direction.

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