Contact probe and socket

Abstract

To provide a contact probe and socket, which have simple structures that provide good contact with electrodes, such as mumps, of a device under measurement.SOLUTION: A contract probe provided herein comprises a conductive leaf spring having a pair of opposing elastic pieces, where each of the elastic pieces has a curved tip portion that is bent in a direction that increases a distance between the opposing pieces toward a tip end, the curved tip portion having a notch formed form the tip end in a direction of a base end.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a contact probe and a socket. [Background technology]

[0002] Pogo pin type contact probes are designed to apply load to the plunger using a coil spring to absorb variations in the height of the device under test and the probe when contacting the device under test. As a result, they are made up of several parts, with electrical contacts between these parts, which makes them expensive and makes it difficult to increase the allowable current.

[0003] On the other hand, when the device under test has bumps such as solder balls, a contact probe with a pin portion whose tip is split into multiple pieces to ensure electrical contact is disclosed in Patent Document 1. However, because the split pin portions open to pinch the bumps during measurement, it is difficult to narrow the arrangement pitch of the contact probe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4021719 Summary of the Invention [Problem to be solved by the invention]

[0005] An example of an object of the present invention is to provide a contact probe and socket that have good contact with electrodes such as bumps of a device under test and are simple in structure. Other objects of the present invention will become apparent from the description of this specification. [Means for solving the problem]

[0006] One aspect of the present invention is a contact probe, a conductive leaf spring having a pair of elastic pieces facing each other; Each elastic piece has a tip curved portion bent in a direction in which the opposing distance increases toward the tip, The distal curved portion has a notch formed from the distal edge toward the proximal end.

[0007] According to the above aspects of the present invention, it is possible to realize a contact probe that has good contact with electrodes such as bumps of a device under test and has a simple structure.

[0008] Any combination of the above components and conversion of the present invention between methods, systems, etc. are also valid aspects of the present invention. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view of a contact probe 1 and a socket 5 according to a first embodiment of the present invention, with a housing portion in cross section. [Figure 2] 1 is a side view of the contact probe 1 and the socket 5, with the housing portion shown in cross section. [Figure 3] 1 is a front view of the contact probe 1 and the socket 5, with the housing section taken in cross section, during measurement (when a load is applied). [Figure 4] 1 is a side view of the contact probe 1 and the socket 5, with the housing section taken in cross section, during measurement (when a load is applied). [Figure 5] 10 is a front view of a contact probe 1A and a socket 5A according to a second embodiment of the present invention, with the housing portion in cross section. FIG. [Figure 6] FIG. 2 is a side view of the contact probe 1A. [Figure 7] FIG. 10 is a side view of a contact probe 1B according to a third embodiment of the present invention. [Figure 8] FIG. 10 is a side view of a contact probe 1C according to a fourth embodiment of the present invention. [Figure 9]10 is a front view of a contact probe 1A and a socket 5B according to a fifth embodiment of the present invention, with the housing portion in cross section. FIG. [Figure 10] FIG. 10 is a front view of a contact probe 1D and a socket 5D of a comparative example, with the housing portion in cross section. [Figure 11] FIG. 10 is a side view of a contact probe 1D and a socket 5D, with the housing portion in cross section. [Figure 12] FIG. 10 is a front view of contact probe 1D and socket 5D, with the housing section taken in cross section, during measurement (when a load is applied). DETAILED DESCRIPTION OF THE INVENTION

[0010] (Embodiment 1) A contact probe 1 and a socket 5 according to a first embodiment of the present invention will be described using Figures 1 to 4. For ease of explanation, the up and down directions are defined in Figure 1. As shown in these figures, the contact probe 1 is a conductive leaf spring 10 integrally having a pair of elastic piece portions 11 facing each other, and each elastic piece portion 11 has a tip curved portion 12 bent in a direction in which the spacing between the elastic piece portions increases toward the tip. As shown in Figures 2 and 4, a notch 13 is formed in the tip curved portion 12 from the tip edge 12a toward the base end.

[0011] The conductive leaf spring 10 is formed by pressing a single sheet of conductive and elastic material such as phosphor bronze or beryllium copper to form two overlapping elastic piece portions 11. When viewed from the side, the elastic piece portions 11 have a generally rectangular tongue shape. The tip curved portions 12 are curved in a generally arc shape with the tip edges 12a moving away from each other. The notch portion 13 has a slit shape of a constant width extending from the tip edge 12a toward the base end. The notch portion 13 has edges in the upper and lower directions. The base of the conductive leaf spring 10 is a generally arc-shaped curved portion 14, and a connecting protrusion 15 is formed on the lower end surface.

[0012] The socket 5 has multiple contact probes 1, a housing 30 made of a non-elastic, rigid insulating hard resin, and a testing board 40. Each contact probe 1 is inserted into and positioned in a through hole 35 formed at a predetermined pitch in the housing 30. The connection protrusion 15 at the base of the contact probe 1 contacts an electrode pad 41 on the testing board 40, which is connected to a measuring device. For ease of explanation, FIG. 1 shows a case where there is one contact probe 1 and one through hole 35, but the socket 5 has multiple through holes 35, and a contact probe 1 is inserted into and positioned in each. The positional relationship between the housing 30 and the testing board 40 is fixed.

[0013] As shown in FIGS. 1 and 2 , when measuring a device under test 50, the device under test 50 is placed on a socket 5, and bumps 51, such as solder balls, constituting electrodes of the device under test 50 are brought into contact with contact probes 1. Then, a load F is applied downward, and the device under test 50 is measured in the state shown in FIGS. 3 and 4 . When the load F causes the bumps 51 to be inserted between the tip curved portions 12 of the contact probes 1, the tip curved portions 12 are pushed open in the direction of arrow G, thereby generating contact pressure on the bumps 51 and absorbing variations in the height of the bumps 51. Furthermore, by forming a slit-shaped notch 13 at the contact portion of the tip curved portions 12 with the bumps 51, the inner edge of the notch 13 contacts the bumps 51, further improving contact with the bumps 51. Furthermore, the amount of opening of the tip curved portions 12 can be reduced.

[0014] For comparison, Figures 10 to 12 show a contact probe 1D and a socket 5D of a comparative example. In this case, contact probe 1D does not have a notch 13, and the other configuration is the same as in embodiment 1. The same or corresponding parts are denoted by the same reference numerals and their description is omitted. In the configuration of the comparative example, since there is no notch 13, during measurement, contact probe 1D contacts bumps 51 of device under test 50 with the inner surface of tip curved portion 12, resulting in inferior contact compared to contact at the edge of notch 13 in embodiment 1. Furthermore, during measurement with load F applied, the amount of opening of tip curved portion 12 in the direction of arrow G also increases, as shown in Figure 12.

[0015] According to this embodiment, the following effects can be achieved.

[0016] (1) The contact probe 1 is a conductive leaf spring 10 having a pair of opposing elastic pieces 11, each of which has a curved tip 12 bent in a direction that widens the gap between the opposing pieces toward the tip. Because there are no internal sliding parts like in a pogo pin, the contact probe 1 has low resistance and can handle a large current. The cost of the contact probe 1 is low because it can be constructed from a single component.

[0017] (2) The tip curved portion 12 of the elastic piece portion 11 has a notch 13 formed from the tip edge 12a toward the base end, so that during measurement, the inner edge of the notch 13 comes into contact with the bump 51 of the device under test 50, resulting in even better contact with the bump 51 than in the comparative example.

[0018] (3) During measurement, the amount of opening of the tip curved portion 12 of the elastic piece portion 11 can be reduced, which makes it possible to accommodate narrower arrangement pitches of the contact probes 1 in the socket 5.

[0019] (4) Since the notch 13 has a slit shape with a constant width extending from the tip edge 12a toward the base end of the contact probe 1, the direction of the edge of the inner surface of the notch 13 is vertical, parallel to the direction in which the device under test 50 is pressed down by the load F. Therefore, the area that rubs against the surface of the bump 51 is extremely narrow.

[0020] (Embodiment 2) A contact probe 1A and a socket 5A according to a second embodiment of the present invention will be described using Figures 5 and 6. This second embodiment is configured to prevent the contact probe 1A from coming off, and the contact probe 1A is configured with a conductive leaf spring 10A in which a retaining protrusion 16 is further formed in the middle of a pair of elastic piece portions 11. The retaining protrusion 16 has an outwardly convex surface, that is, a convex surface facing the inner surface of the through hole 35A of the housing portion 30A. The other configuration of the conductive leaf spring 10A is substantially the same as that of the first embodiment described above.

[0021] The housing 30A has a main body 31 and a bottom plate 32, and a through hole 35A formed in the housing 30A is composed of a small diameter anti-slip portion 36 at the upper end, a large diameter portion 37 into which the anti-slip protrusion 16 is inserted, and a positioning small diameter portion 38 at the lower end. The small diameter anti-slip portion 36 and the large diameter portion 37 are formed in the main body 31, and the positioning small diameter portion 38 is formed in the bottom plate 32. Electrode pads of the testing board 40 are not shown in the illustration. The other configuration of the housing 30A is substantially the same as that of the first embodiment described above.

[0022] The procedure for inserting the housing portion 30A of the contact probe 1A will be described with reference to Figure 5. At position A before insertion, a force is applied in the direction of arrow H to narrow the gap between the pair of elastic pieces 11 of the conductive leaf spring 10A, and the base of the conductive leaf spring 10A is inserted into the through-hole 35A as shown at position B. The conductive leaf spring 10A is further inserted up to position C, and then the force narrowing the pair of elastic pieces 11 is released. The retaining protrusions 16 at the middle of the pair of elastic pieces 11 get caught on the small diameter portions 36 of the through-hole 35A to prevent them from coming out.

[0023] According to this embodiment 2, since the retaining projection 16 is formed in the middle of the pair of elastic pieces 11, the elasticity of the contact probe 1A made of the conductive leaf spring 10A can be utilized to easily insert the contact probe 1A into the through hole 35A of the housing part 30A and to prevent it from falling out. Other functions and effects are the same as those of the above-mentioned embodiment 1.

[0024] (Embodiment 3) 7 shows contact probe 1B according to embodiment 3 of the present invention. In this case, contact probe 1B is formed with a generally arc-shaped notch 13B that narrows from tip edge 12a of tip bent portion 12 of elastic piece portion 11 toward the base end of conductive leaf spring 10. The configuration other than notch 13B is the same as that of embodiment 1 or 2 described above.

[0025] In this embodiment 3, the bumps on the device under test are contacted at the inner edge of the notch 13B, thereby improving contact with the bumps and reducing the amount of opening of the tip curved portion 12 of the elastic piece portion 11 during measurement.

[0026] (Embodiment 4) 8 shows contact probe 1C according to embodiment 4 of the present invention. In this case, contact probe 1C is formed with a substantially trapezoidal notch 13C that widens from tip edge 12a of tip bent portion 12 of elastic piece portion 11 toward the base end of conductive leaf spring 10. The configuration other than notch 13C is the same as that of embodiment 1 or 2 described above.

[0027] In this fourth embodiment, the inner edge of the notch 13C contacts the bumps of the device under test, thereby improving contact with the bumps. In addition, by devising the shape of the notch 13C, the amount of opening of the tip curved portion 12 of the elastic piece 11 during measurement can be further reduced.

[0028] (Embodiment 5) FIG. 9 shows contact probes 1A and socket 5B according to a fifth embodiment of the present invention. In this case, each contact probe 1A itself is the same as in the second embodiment, but in socket 5B, the arrangement direction of each contact probe 1A is different. In other words, when viewed from above the socket, the directions in which the opposing pairs of elastic piece portions 11 of at least some adjacent contact probes 1A extend are different from each other. Within the range shown in FIG. 9, the direction in which the elastic piece portion 11 of the central contact probe 1A extends is rotated by 90 degrees from the directions in which the elastic piece portions 11 of the contact probes 1A on both sides extend. The rest of the configuration is the same as in the second embodiment described above.

[0029] In this embodiment 5, the contact probes 1A on both sides of Figure 9 open laterally parallel to the paper surface during measurement, while the central contact probe 1A opens in a direction perpendicular to the paper surface during measurement. Therefore, the opening directions of the contact probes 1A alternate in different directions (orthogonal directions), making it possible to narrow the arrangement pitch of the contact probes 1A in the housing part 30A. Other effects are the same as those of the above-mentioned embodiment 2.

[0030] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted.

[0031] In the first embodiment, the distal curved portion 12 is exemplified as having a curved shape, but the distal curved portion may be bent linearly in a direction in which the opposing distance widens toward the distal end.

[0032] In the first, second, and fifth embodiments, the sockets 5, 5A, and 5B are described as having the test board 40, but the sockets may not have a test board. For example, there may be a configuration in which the test board is in a separate device, and the socket without a test board is attached to the test board in the separate device.

[0033] In embodiment 3, an approximately arc-shaped notch 13B is shown as an example of a notch having a portion that narrows from the tip edge 12a of the tip curved portion 12 toward the base end, but it may also be approximately U-shaped or V-shaped.

[0034] In embodiment 4, a substantially trapezoidal cutout 13C is shown as an example of a cutout having a portion that widens from the distal edge 12a of the distal curved portion 12 toward the base end, but other shapes may also be used.

[0035] According to the present specification, there are provided a contact probe and a socket of the following aspects.

[0036] (Aspect 1) a conductive leaf spring having a pair of elastic pieces facing each other; Each elastic piece has a tip curved portion bent in a direction in which the opposing distance increases toward the tip, A contact probe in which a notch is formed in the tip curved portion from the tip edge toward the base end.

[0037] According to the above-mentioned first aspect, the device can be constructed from a single component, has low resistance, can increase the allowable current, and is low cost. The tip curved portion of the elastic piece has a notch formed from the tip edge toward the base end, so that the edge of the notch makes contact with the bump or other electrode of the device under test during measurement, resulting in good contact. During measurement, the amount of separation between the opposing tip curved portions can be reduced, allowing for narrower arrangement pitches of contact probes in the socket.

[0038] (Aspect 2) The notch has a slit shape with a constant width extending from the tip edge toward the base end of the contact probe.

[0039] According to the second aspect, the notch has a slit shape with a constant width extending from the distal end toward the proximal end, so that the edge of the notch is oriented in the vertical direction parallel to the direction in which the device under test is pressed down during measurement, thereby rubbing the electrode surface of bumps and the like over a very narrow area.

[0040] (Aspect 3) The notch has a shape that narrows in width from the tip edge toward the base end.

[0041] According to the above-mentioned third aspect, contact is good during measurement because the edges of the notches come into contact with electrodes such as bumps on the device under test. This reduces the amount of separation between the opposing curved tip portions during measurement, making it possible to accommodate narrower arrangement pitches of contact probes in sockets.

[0042] (Aspect 4) The notch has a shape that widens from the tip edge toward the base end.

[0043] According to the above-mentioned fourth aspect, contact is good during measurement because the edges of the notches come into contact with electrodes such as bumps on the device under test. This reduces the amount of separation between the opposing curved tip portions during measurement, making it possible to accommodate narrower arrangement pitches of contact probes in sockets.

[0044] (Aspect 5) A contact probe, wherein a projection for preventing slip-out is formed in an intermediate portion of the pair of elastic pieces.

[0045] According to the fifth aspect described above, the contact probe is a leaf spring, and the elasticity of the contact probe can be utilized to easily insert the contact probe into the through-hole of the housing portion and to position the contact probe so that it will not fall out.

[0046] (Aspect 6) A socket comprising the contact probe and a housing portion into which the contact probe is inserted.

[0047] According to the sixth aspect described above, the contact probes provided in the socket can reduce the amount by which the curved tip portions facing each other open during measurement, making it possible to accommodate narrower arrangement pitches of the contact probes.

[0048] (Aspect 7) A socket in which the opposing pairs of elastic piece portions of at least some of the adjacent contact probes extend in mutually different directions.

[0049] According to the above-mentioned aspect 7, the directions in which the opposing pairs of elastic piece portions of at least some of the adjacent contact probes expand (rotational positions) are different from each other, so that the opening directions of the contact probes alternate during measurement, making it possible to narrow the arrangement pitch of the contact probes in the housing portion.

[0050] (Aspect 8) The socket further comprises a substrate having an electrode, the base of the contact probe contacting the electrode of the substrate.

[0051] According to the eighth aspect described above, the base of the contact probe comes into contact with the electrode of the substrate, which simplifies the structure of the socket. [Explanation of symbols]

[0052] 1,1A,1B,1C,1D Contact Probes 5, 5A, 5B, 5D sockets 10,10A conductive leaf spring 11 Elastic piece 12 Tip curved part 12a Tip edge 13, 13B, 13C Notch 16. Protrusion for preventing slipping out 30,30A housing 35,35A through hole 40 Test board 41 Electrode Pads 50 Device Under Test 51 Bump

Claims

1. a conductive leaf spring having a pair of elastic pieces facing each other; Each elastic piece has a tip curved portion bent in a direction in which the opposing distance increases toward the tip, A contact probe in which a notch is formed in the tip curved portion from the tip edge toward the base end.

2. The contact probe according to claim 1 , wherein the notch has a slit shape with a constant width extending from the tip edge toward the base end.

3. The contact probe according to claim 1 , wherein the notch has a shape that narrows in width from the tip edge toward the base end.

4. The contact probe according to claim 1 , wherein the notch has a shape that widens from the tip edge toward the base end.

5. The contact probe according to claim 1 , wherein a projection for preventing slipping-out is formed at an intermediate portion of the pair of elastic pieces.

6. The contact probe according to any one of claims 1 to 5; a housing portion into which the contact probe is inserted.

7. 7. The socket according to claim 6, wherein at least some of the adjacent contact probes have opposing pairs of elastic pieces that extend in different directions.

8. The socket of claim 6 further comprising a substrate having an electrode, the base of the contact probe contacting the electrode of the substrate.

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