TWI463141B - Contact probe and probe unit - Google Patents

Description

Contact probe and probe unit

The present invention relates to a conductive contact probe for use in an on-state inspection or an operation characteristic inspection of an inspection object such as a semiconductor package or a liquid crystal panel, and a probe unit including the same.

In the past, when performing an on-state inspection or an operation characteristic inspection of an inspection object such as a semiconductor package or a liquid crystal panel, a plurality of contact probes of conductivity are used in accordance with the installation pattern of the external connection electrodes included in the inspection target. The needle is disposed in a probe unit at a predetermined position. In the probe unit, the contact object and the wiring substrate are electrically connected by contacting the both ends of the contact probe with the electrodes of the wiring substrate for outputting the electrode to be inspected and the inspection signal. (See, for example, Patent Document 1). In such a probe unit, it is possible to narrow the distance between adjacent contact probes in accordance with a technique corresponding to the progress of high integration and miniaturization of semiconductor packages or liquid crystal panels in recent years. The technology has been increasingly improved.

However, the electrode of the inspection object may be spherical. As a contact probe suitable for contact with such a spherical electrode, as disclosed in Patent Document 1, a contact probe including a first plunger having a plurality of protrusions is provided. a front end portion of a crown shape for contacting a spherical electrode, wherein the protruding portions are formed in a hammer shape that is identical to each other and protrude in a longitudinal direction, and are disposed at a position rotationally symmetrical with respect to a central axis of the longitudinal direction; The second plunger is for contacting the wiring substrate; and the coil spring is for connecting the two plungers. The coil spring of the contact probe has a densely wound portion, the wire is densely wound, and the end portion is attached to the first plunger; and the sparsely wound portion is separated by a wire extending from the densely wound portion. The opening is wound at a predetermined interval, and the end portion is attached to the second plunger.

According to the contact probe described above, the plurality of protrusions can cut off the dirt or the oxide film existing on the surface of the spherical electrode, and can achieve a reliable electrical connection with the spherical electrode. Further, according to the contact probe described above, when the load at the time of inspection is applied from the outside, since the first and second plungers are electrically connected to the densely wound portion of the coil spring, the conduction path can be shortened to realize inductance (inductance). ) or the reduction and stabilization of the resistance. Therefore, by using the probe unit including the above-described contact probe, it is possible to ensure stable conduction of the semiconductor package or the like during inspection.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2002-107377

In the case of the above-described conventional contact probe, at the end portion of the first plunger, a plurality of protruding portions are disposed in rotational symmetry with respect to a central axis in the longitudinal direction, and contact with the spherical electrode is made. The action of the probe is substantially linear along the length direction. Therefore, when the bending of the coil spring at the time of load application is small, there is a possibility that sufficient contact cannot be obtained between the second plunger and the tightly wound portion of the coil spring. In this case, since the unwinding portion of the coil spring is included in the conduction path, the inductance or the resistance is increased, and there is a possibility that the stable conduction cannot be ensured.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a contact probe capable of reliably cutting an oxide film existing on a surface of a spherical electrode contacting a target, and ensuring stable conduction, and having the contact Probe unit for the probe.

In order to achieve the object of solving the above problems, the contact probe of the present invention is a needle-shaped conductive contact probe which is expandable and contractable in the longitudinal direction, and is characterized in that it has a plurality of protruding portions which are provided in An end portion of at least one of the longitudinal directions protrudes in a hammer shape or a mountain shape along the longitudinal direction, and includes a protruding portion having a height at a front end in the longitudinal direction different from that of the other protruding portions.

Further, in the above-described invention, the contact probe according to the present invention includes: a first plunger having a plurality of protruding portions; and a second plunger located at an end portion in the longitudinal direction, wherein the end portion is the aforementioned The end portion of the first plunger is different from the end portion, and the coil spring is configured to connect the first plunger and the second plunger, and expand and contract along the longitudinal direction.

Further, in the contact probe of the present invention, the coil spring has a densely wound portion, the wire is densely wound, and one end portion is attached to one of the first and second plungers; The unwinding portion is formed by winding a wire extending continuously from the other end portion of the densely wound portion at a predetermined pitch from the other end portion, and the end portion on the side not connected to the densely wound portion is formed Mounted on the other of the first and second plungers; and the other of the first and second plungers to which the unwinding portion is attached, at least the load at the time of inspection is applied to the contact probe to cause the aforementioned When the coil spring is contracted, it enters the inner peripheral side of the dense winding portion.

Further, in the contact probe of the present invention, the first plunger has a first base end that is inserted into the coil spring, and the second plunger has a second base that is inserted into the coil spring. The end portion has a length in the longitudinal direction of the second proximal end portion that is shorter than the first proximal end portion, and the densely wound portion is attached to the first plunger.

Further, the probe unit of the present invention includes: the plurality of contact probes according to the above aspect of the invention; and the probe holder, wherein a plurality of the contact probes are formed on one surface to prevent the both ends of the contact probe from being exposed to the outside The holding hole of the contact probe is held in a state where at least the surface is insulative.

According to the invention, the plurality of protruding portions are provided at the end portions of at least one of the longitudinal directions, and protrude in a hammer shape or a mountain shape along the longitudinal direction, and include the front end along the longitudinal direction. Since the protrusions are different in height from the other protrusions, the timing at which the plurality of protrusions are in contact with the spherical electrodes of the contact object may be different, and the one end of the contact first will move while wiping the spherical electrode. Therefore, the oxide film existing on the surface of the spherical electrode contacting the object can be surely chipped, and stable conduction can be ensured.

The form for carrying out the invention (hereinafter referred to as "embodiment") will be described below with reference to the drawings. In addition, the drawings are schematic, the relationship between the thickness and the width of each part, the ratio of the thickness of each part, etc., should be noted that there are cases different from the actual ones. Of course, the drawings also include the relationship of each other's dimensions or The case of a different ratio.

Fig. 1 is a perspective view showing the configuration of a probe unit according to an embodiment of the present invention. Fig. 2 is a partial cross-sectional view showing the configuration of a main part of the probe unit of the embodiment. The probe unit 1 shown in these figures is used to electrically connect the semiconductor package 100 to the wiring substrate 200 for outputting an inspection signal to the semiconductor package 100, and to perform semiconductors belonging to the inspection object. The device (test socket) used in the inspection of the electrical characteristics of the package 100.

The probe unit 1 includes a conductive contact probe 2 that is in contact with the semiconductor package 100 and the wiring substrate 200 that are different from each other in the longitudinal direction at both ends in the longitudinal direction, and the probe holder 3 has a plurality of probe holders 3 The contact probes 2 are housed and held in accordance with a predetermined pattern, and at least the surface is insulative; and an insulating base member 4 is disposed so as to surround the outer periphery of the probe holder 3, The needle holder 3 is fixed and held, and the positional deviation of the semiconductor package 100 at the time of inspection is suppressed.

The contact probe 2 has a first plunger 21 for contacting the spherical electrode 101 of the semiconductor package 100, and a second plunger 22 located at an end portion of the contact probe 2 in the longitudinal direction and used for wiring. The electrode 201 of the substrate 200 is in contact with the end portion of the end portion where the first plunger 21 is located, and the coil spring 23 is connected to the first plunger 21 and the second plunger 22, and is in contact with each other. The length direction of the probe 2 is stretchable and freely. The first plunger 21, the second plunger 22, and the coil spring 23 have the same axis.

The first plunger 21 has a distal end portion 21a for contacting the spherical electrode 101 of the semiconductor package 100, and a flange portion 21b provided on the proximal end side of the distal end portion 21a and having a front end portion 21a. The diameter of the larger diameter; the cylindrical boss portion 21c is provided on the opposite side of the front end portion 21a with respect to the flange portion 21b, and has a diameter smaller than the diameter of the flange portion 21b and the inner diameter of the coil spring 23. The coil springs 23 are pressurized at substantially the same diameter, and the base end portion (first base end portion) 21d is provided on the opposite side of the flange portion 21b with respect to the convex shaft portion 21c to form a coil having a smaller diameter. The spring 23 has a cylindrical shape with a small inner diameter and extends from the convex shaft portion 21c.

Fig. 3 is a plan view showing the front end portion 21a as seen from the direction of the arrow A in Fig. 2 . Further, the front end portion 21a shown in Fig. 2 shows the side surface when viewed from the direction of the arrow B in Fig. 3 . As shown in FIG. 3, the distal end portion 21a has four protruding portions 211a that protrude in a hammer shape along the longitudinal direction of the contact probe 2. Among the four protruding portions 211a, the height of the front end of the two protruding portions 211a located on the left side of the central portion in the third figure in the longitudinal direction (the amount of protrusion) is two protrusions on the right side of the central portion in the third figure. The front end of 211a has a greater height in the length direction. The difference in height is preferably about 3 to 25% of the distance between the front ends of the two protruding portions 211a which are different in height from each other.

The second plunger 22 has a substantially round hammer-shaped front end portion 22a. The flange portion 22b is provided on the proximal end side of the distal end portion 22a and has a diameter larger than the diameter of the distal end portion 22a. The cylindrical convex shaft The portion 22c is provided on the opposite side of the front end portion 22a with respect to the flange portion 22b, and has a diameter smaller than the diameter of the flange portion 22b and substantially equal to the inner diameter of the coil spring 23, and the other end portion of the coil spring 23 is provided. The press-fit and the base end portion (second base end portion) 22d are provided on the opposite side of the flange portion 22b from the convex shaft portion 22c, and have a smaller diameter than the convex shaft portion 22c and a diameter smaller than the inner diameter of the coil spring 23. The small cylindrical shape extends from the convex shaft portion 22c. The length of the base end portion 22d in the longitudinal direction of the contact probe 2 is longer than the length of the base end portion 21d of the first plunger 21.

The coil spring 23 includes a densely wound portion 23a in which the wire is densely wound, and a sparsely wound portion 23b that is spaced apart from the one end portion by a predetermined distance from the one end portion of the densely wound portion 23a. The ground is wound up. The end portion of the densely wound portion 23a is press-fitted into the convex shaft portion 21c of the first plunger 21, and the end portion of the sparsely wound portion 23b is press-fitted into the convex shaft portion 22c of the second plunger 22. Further, the first plunger 21 and the second plunger 22 may be joined to the coil spring 23 by the winding force and/or welding of the spring.

In the contact probe 2 having the above configuration, the length of the base end portion 22d of the second plunger 22 and the length of the tightly wound portion 23a of the coil spring 23 are set to be applied to the contact probe at least at the time of inspection. 2, in a state where the coil spring 23 is contracted, one portion of the proximal end portion 22d is brought into the inner peripheral side of the densely wound portion 23a.

The contact probe 2 is formed using a noble metal or a noble metal alloy. The noble metal referred to herein means, for example, gold (Au), silver (Ag), platinum (Pt), palladium (Pd), rhodium (Rh), or the like. The noble metal or noble metal alloy to which the present embodiment is applied has a Vickers hardness (HV) of 400 or more and a specific resistance of 5.00 × 10 ^-8 Ω ‧ m or less. Further, copper, a copper alloy, iron, tungsten, a tantalum alloy or the like may be used as the material of the contact probe 2.

The diameter of the contact probe 2 is about several tens of μm to several hundreds of μm. Further, the length of the contact probe 2 in the longitudinal direction is about several mm to several tens of mm.

Next, the configuration of the probe holder 3 will be described. The probe holder 3 is configured by laminating the first substrate 31 and the second substrate 32 in the thickness direction (the lower direction in the second drawing).

In the first substrate 31, a plurality of holding holes 33 penetrating in the thickness direction are provided. The position at which the hole 33 is formed is determined in accordance with the wiring pattern of the semiconductor package 100. The holding hole 33 is a stepped hole having a cylindrical small diameter portion 33a that can be inserted into the front end portion 21a of the first plunger 21, and a cylindrical large diameter portion 33b. The smaller diameter portion 33a is larger and is formed coaxially with the small diameter portion 33a. The diameter of the large diameter portion 33b is larger than the outer diameter of the coil spring 23, and has a gap that can be bent when the load is applied to the coil spring 23 and contracted. The diameter of the small diameter portion 33a is smaller than the diameter of the flange portion 21b of the first plunger 21. Therefore, in the state shown in Fig. 2, the flange portion 21b is prevented from coming off the probe holder 3 by abutting against the boundary wall surface between the small diameter portion 33a and the large diameter portion 33b.

In the second substrate 32, a plurality of holding holes 34 corresponding to the plurality of holding holes 33 of the first substrate 31 are provided. The holding hole 34 is coaxially connected to any of the plurality of holding holes 33 provided in the first substrate 31, and forms a holder hole together with the holding hole 33. The holding hole 34 is a stepped hole having a cylindrical small diameter portion 34a that can be inserted into the front end portion 22a of the second plunger 22, and a cylindrical large diameter portion 34b. The smaller diameter portion 34a is larger and is formed coaxially with the small diameter portion 34a. The diameter of the small diameter portion 34a is smaller than the diameter of the flange portion 22b of the second plunger 22. Therefore, in the state shown in Fig. 2, the flange portion 22b is prevented from coming off the probe holder 3 by abutting against the boundary wall surface between the small diameter portion 34a and the large diameter portion 34b. The diameter of the large diameter portion 34b is equal to the diameter of the large diameter portion 33b of the holding hole 33, and is larger than the outer diameter of the coil spring 23.

The holding holes 33, 34 are formed by drilling, etching, punching, or processing using a laser, an electron beam, an ion beam, a wire discharge, or the like.

The probe holder 3 having the above configuration may be formed of an insulating material such as a resin, a machinable ceramic, or a crucible, or may be formed of a metal or an alloy as a base material. An insulating film such as a resin is formed on the surface of the base material.

In the probe holder 3, the pitch of the adjacent holder holes is about several tens of μm to several hundreds of μm.

Next, the operation of the semiconductor package 100 to contact the probe 2 at the time of inspection will be described. When the spherical electrode 101 of the semiconductor package 100 comes into contact with the first plunger 21 of the contact probe 2 in proximity to the probe unit 1, the contact probe 2 has only a large amount of protrusion in the longitudinal direction. The protruding portion 211a of the end (the two protruding portions 211a on the left side in the central portion of Fig. 3) is in contact with the spherical electrode 101. Therefore, in this state, the contact between the distal end portion 21a and the spherical electrode 101 is unstable.

Thereafter, when the semiconductor package 100 is further brought close to the contact probe 2, the coil spring 23 starts to contract. At this time, the first plunger 21 is held in contact with the spherical electrode 101 by the protruding portion 211a that is in contact with the spherical electrode 101, and the protruding portion 211a that is not in contact with the spherical electrode 101 is gradually approaching the spherical electrode. 101. After that, when all of the protruding portions 211a are in contact with the spherical electrode 101, the spherical electrode 101 is stably held by the four protruding portions 211a. In this state, the longitudinal direction of the first plunger 21 is slightly inclined with respect to the longitudinal direction of the holding hole 33.

The protruding portion 211a that first contacts the spherical electrode 101 is such that the surface of the spherical electrode 101 is moved while the remaining protruding portion 211a is in contact with the spherical electrode 101, so that the surface of the spherical electrode 101 can be moved. The oxide film is removed.

In a state where all the protruding portions 211a are in contact with the spherical electrode 101, the coil spring 23 contracts in a state of being bent in accordance with the rotation of the first plunger 21. Therefore, the base end portion 22d of the second plunger 22 not only enters the inner peripheral side of the densely wound portion 23a, but also a part of the side surface of the proximal end portion 22d is pressed against the inner side surface of the densely wound portion 23a. As a result, a larger contact pressure is generated between the base end portion 22d and the densely wound portion 23a than when the coil spring 23 is not bent, and stable conduction can be ensured. In such a contact probe 2, it is possible to prevent the signal from flowing to the unwinding portion 23b at the time of inspection, and it is possible to reduce and stabilize the inductance or the resistance.

According to one embodiment of the present invention, the end portion provided in at least one of the longitudinal directions is protruded in a hammer shape along the longitudinal direction, and the height at the front end along the longitudinal direction is different from the others. Since the plurality of protrusions are in contact with the spherical electrodes of the contact object, the time at which the protrusions are in contact with one another will move while wiping the spherical electrodes. Therefore, the oxide film existing on the surface of the spherical electrode contacting the object can be surely chipped, and stable conduction can be ensured.

Further, in the present invention, in the same manner as in the above-described embodiment, when the end portion of the first plunger is formed, the bottoms of the two V-shaped grooves which are orthogonal to each other may be passed from the front end portion to the front end portion after the processing. The position of the center offset of the circle of the end face. In this case, the height of the front end of the protruding portion in the longitudinal direction becomes three. Further, the two V-shaped grooves may be formed not to be orthogonal to each other.

Further, in the present invention, it is also possible to have three or more V-shaped grooves at the end portions of the first plunger. In this case, it is also assumed that the bottom of at least one groove is displaced from the central axis of the longitudinal direction of the distal end portion.

Further, in the present invention, the front end portion of the first plunger may have two mountain portions having different heights in the longitudinal direction.

Further, in the present invention, the length of the first base end portion in the longitudinal direction of the contact probe may be longer than the length of the second base end portion, and the end portion of the sparse winding portion may be pressed. On the other hand, the convex shaft portion of the first plunger is configured to press the end portion of the densely wound portion into the convex shaft portion of the second plunger. In this case, the first base end portion is brought into the inner peripheral side of the densely wound portion in a state where the load is applied to the contact probe and the coil spring is contracted at least during the inspection. In the contact probe having such a configuration, the first plunger rotates and is tilted during the inspection, and the base end portion of the first plunger enters the inner peripheral portion of the tightly wound portion of the coil spring. Therefore, one of the side faces of the base end portion of the first plunger comes into contact with the inner side surface of the densely wound portion. Therefore, as in the above embodiment, stable conduction can be ensured.

Further, in the present invention, the second plunger having the same end shape as the front end portion 21a of the first plunger 21 may be applied to the distal end portion. At this time, it is preferable to determine the positional relationship between the front end portion 21a of the first plunger 21 and the front end portion of the second plunger in consideration of the bending of the coil spring 23.

Further, in the present invention, at least the surfaces of the first and second protruding portions may be covered with a plating film such as electric field plating or gold plating. Thereby, the durability of the first and second protruding portions can be improved.

In addition, the probe unit of the present invention is not limited to test sockets suitable for inspection of semiconductor packages. That is, the probe unit of the present invention can also be suitably used for inspection as a liquid crystal panel or wafer.

Further, the contact probe of the present invention can be suitably used as a connector for electrically connecting constituent components of, for example, a hybrid automobile, in addition to inspection for a semiconductor package or the like. The diameter of the contact probe used as such a connector is larger than the diameter of the contact probe described in the above embodiment.

As described above, the present invention can be embodied in various embodiments that are not described herein, and various design changes and the like can be made without departing from the scope of the technical scope of the invention.

[Industrial availability]

As described above, the contact probe of the present invention can surely cut off the oxide film existing on the surface of the spherical electrode contacting the object and contribute to ensuring stable conduction.

1‧‧‧ probe unit

2‧‧‧Contact probe

3‧‧‧Probe Holder

4‧‧‧Base member

21‧‧‧1st plunger

21a, 22a‧‧‧ front end

21b, 22b‧‧‧Flange

21c, 22c‧‧‧ convex axis

21d, 22d‧‧‧ base end

22‧‧‧2nd plunger

23‧‧‧ coil spring

23a‧‧‧Dense winding department

23b‧‧‧Sparging Department

31‧‧‧1st substrate

32‧‧‧2nd substrate

33, 34‧‧‧ Keep the hole

33a, 34a‧‧‧ Small Trails Department

33b, 34b‧‧‧The Great Trails Department

100‧‧‧Semiconductor package

101‧‧‧Spherical electrode

200‧‧‧Wiring substrate

201‧‧‧ electrodes

211a‧‧‧Protruding

Fig. 1 is a perspective view showing the overall configuration of a probe unit according to an embodiment of the present invention.

Fig. 2 is a view showing the configuration of a main part of a probe unit according to an embodiment of the present invention.

Fig. 3 is a plan view showing the shape of the end portion of the first plunger of the contact probe according to the embodiment of the present invention.

1. . . Probe unit

2. . . Contact probe

3. . . Probe holder

4. . . Base member

100. . . Semiconductor package

200. . . Wiring substrate

Claims (7)

A contact probe which is a needle-shaped conductive contact probe which is expandable and contractible in the longitudinal direction, and is characterized in that it has four protruding portions which are formed by two non-orthogonal The V-shaped groove is provided at an end portion of at least one of the longitudinal directions, and protrudes in a hammer shape or a mountain shape along the longitudinal direction, and includes a protruding portion having a height at a front end in the longitudinal direction different from that of the other protruding portions. The contact probe according to claim 1, further comprising: a first plunger having a plurality of protrusions; and a second plunger located at an end portion in the longitudinal direction, the end portion being An end portion of the end portion where the first plunger is located; and a coil spring for connecting the first plunger and the second plunger, and being expandable and contractible along the longitudinal direction. The contact probe according to claim 2, wherein the coil spring has a densely wound portion, the wire is densely wound, and one end portion is attached to the first and second plungers. The one side and the sparsely wound portion are formed by winding a wire extending continuously from the other end portion of the densely wound portion from the other end portion at a predetermined pitch, and not being connected to the densely wound portion The other end is attached to the other of the first and second plungers; and the other of the first and second plungers to which the unwinding portion is attached is applied to the contact probe at least during inspection. a state in which the coil spring is contracted by the needle, and enters the inner circumference of the dense winding portion side. The contact probe according to claim 1, wherein the coil spring has a densely wound portion, the wire is densely wound, and one end portion is attached to the first and second plungers. The one side and the sparsely wound portion are formed by winding a wire extending continuously from the other end portion of the densely wound portion from the other end portion at a predetermined pitch, and not being connected to the densely wound portion The other end is attached to the other of the first and second plungers; and the other of the first and second plungers to which the unwinding portion is attached is applied to the contact probe at least during inspection. The needle is brought into the inner peripheral side of the densely wound portion in a state where the coil spring is contracted. The contact probe according to claim 4, wherein the first plunger has a first base end that is inserted into the coil spring, and the second plunger has a coil spring inserted therein The second proximal end portion has a length in the longitudinal direction of the second proximal end portion that is shorter than the first proximal end portion, and the densely wound portion is attached to the first plunger. The contact probe according to claim 3, wherein the first plunger has a first base end that is inserted into the coil spring, and the second plunger has a coil spring inserted therein 2nd The proximal end portion has a length in the longitudinal direction of the second proximal end portion that is shorter than the first proximal end portion, and the densely wound portion is attached to the first plunger. A probe unit, comprising: a plurality of contact probes according to any one of claims 1 to 6; and a probe holder formed with a plurality of contact probes on one side The end portion is exposed to the outside while being prevented from falling off, and the holding holes of both end portions of the contact probe are held, and at least the surface is insulative.