JP7113067B2 - Contact probe and test socket with it - Google Patents

Description

The present invention relates to a contact probe and a test socket including the contact probe used, for example, in testing the electrical characteristics of a semiconductor integrated circuit.

In recent years, this type of contact probe electrically connects an electrode provided on an object to be tested and a land provided on a printed circuit board. and an elastic body provided between the first contact terminal and the second contact terminal for biasing the first contact terminal and the second contact terminal away from each other. there is The electrode has a hemispherical tip that contacts the top of the second contact terminal. When inspecting the electrical characteristics of a semiconductor integrated circuit, if a contact error occurs between the electrode and the top of the second contact terminal, the device to be tested that should be judged to be acceptable may be judged to be unacceptable. An object to be inspected that should be determined to be unacceptable may be determined to be acceptable, and the inspection function cannot be exhibited, resulting in a loss of reliability of the inspection. The above-mentioned contact failure between the top of the electrode and the second contact terminal may be due to variations in the shape of the top of the electrode and the second contact terminal, or the misalignment of the top of the electrode and the second contact terminal when the test socket is assembled. It was supposed to occur when the positional relationship deviated from the predetermined position.

This is because the electrode is hemispherical and the top of the second contact terminal is a fixed bifurcated protrusion (see, for example, Patent Document 1).

JP 2016-75709 A

However, conventional contact probes have the following problems.

In conventional contact probes, the top of the second contact terminal consists of a bifurcated protrusion, which is fixed.

Therefore, when the hemispherical electrode and the projection are misaligned, that is, when the center line of the projection and the center line of the electrode are misaligned, when inspecting the electrical characteristics of the semiconductor integrated circuit as described above, A contact error between the electrode and the top of the second contact terminal occurs, and the inspection function cannot be fully exhibited, resulting in loss of reliability of the inspection socket.

SUMMARY OF THE INVENTION The present invention has been made to solve the conventional problems. To provide a contact probe and an inspection socket equipped with the contact probe capable of eliminating contact errors at the tops of two contact terminals, sufficiently exhibiting an inspection function, and improving the reliability of the inspection socket.

A contact probe according to the present invention is a contact probe for electrically connecting an electrode provided on an object to be tested and a land provided on a printed circuit board, the first contact terminal contacting the land; a second contact terminal that contacts the electrode; an elastic body that is provided between the first contact terminal and the second contact terminal and biases the first contact terminal and the second contact terminal away from each other; wherein the first contact terminal is configured by a first contact element formed of a planar metal plate, the second contact terminal is formed of a planar metal plate, and has a bifurcated tip end A pair of second contact elements which are separated and have at least two vertices, sandwich a part of the first contact element, and are provided so as to be in frictional contact with the first contact element; and a flat metal plate. a pair of third contact elements having at least two apexes with bifurcated tips, located outside the second contact elements, and provided to frictionally contact the second contact elements; wherein the first contact element, the second contact element and the third contact element can move relatively toward and away from the electrode and the land while frictionally contacting each other; A body is provided to surround a portion of the third contact element, and elastically presses the first contact element against the land and elastically presses the second contact element and the third contact element against the electrode. It is composed of a coil spring that

Since the contact probe according to the present invention is configured as described above,
The first contact element, the second contact element and the third contact element can be moved relatively toward and away from the electrode and the land while frictionally contacting each other. As the number of contact elements increases, it is possible to eliminate contact errors with the electrodes. As a result, it is possible to reliably improve the inspection performance of the contact probe.

Furthermore, in the contact probe according to the present invention, the electrode has a hemispherical tip that contacts the second contact element and the third contact element, and the second contact element and the third contact element are: The contact according to the present invention has at least two vertexes each contacting the tip of the electrode, and the distance between the vertices of the second contact element is smaller than the distance between the vertices of the third contact element. The probe can obtain the following effects in addition to the effects described above. That is, the apexes of the second contact element and the third contact element can follow the shape of the hemispherical tip of the electrode. As a result, the second contact element and the third contact element can be stably brought into contact with the electrode while eliminating contact errors of the second contact element and the third contact element with the electrode.

Furthermore, in the contact probe according to the present invention, the electrode has a hemispherical tip that contacts the second contact element and the third contact element, and the second contact element and the third contact element are: each having at least two vertices contacting the tip of the electrode, the height of the apex of the second contact element being lower than the height of the third contact element, and the apex of the second contact element and the third contact element There is a height difference at the apex of the three contact elements.

The contact probe according to the present invention can obtain the following effects in addition to the effects described above. That is, the two apexes of each of the second contact element and the third contact element can follow the shape of a hemispherical tip, and the contact of the second contact element and the third contact element to the electrode The second contact element and the third contact element can be stably brought into contact with the electrode without any mistakes.

In the contact probe according to the present invention, the electrode has a hemispherical tip that contacts the second contact element and the third contact element, and the second contact element and the third contact element each have the The second contact element has at least two vertices in contact with the electrode, the second contact element has a apex distance smaller than the third contact element apex distance, and the second contact element has a apex height greater than the third contact element. 3 lower than the height of the contact element, and the apex of the second contact element and the apex of the third contact element are arranged such that the apex of the second contact element and the third contact element can follow the shape of the hemispherical tip. There is a difference in height.

The contact probe according to the present invention can obtain the following effects in addition to the effects described above. That is, in the second contact element and the third contact element, the two apexes of each of the second contact element and the third contact element contacting the electrode well follow the shape of the hemispherical tip. Thus, the second contact element and the third contact element can be stably brought into contact with the electrode while eliminating contact errors of the second contact element and the third contact element with the electrode.

A contact probe according to the present invention is a contact probe for electrically connecting an electrode provided on a device under test and a land provided on a printed circuit board, comprising: a first contact terminal that contacts the land; a second contact terminal that contacts the electrode; an elastic body that is provided between the first contact terminal and the second contact terminal and biases the first contact terminal and the second contact terminal away from each other; wherein the first contact terminal is configured by a first contact element formed of a planar metal plate, the second contact terminal is formed of a planar metal plate, and has a bifurcated tip end A pair of second contact elements which are separated and have at least two vertices, sandwich a part of the first contact element, and are provided so as to be in frictional contact with the first contact element; and a flat metal plate. a pair of third contact elements whose tips are bifurcated and have at least two vertices, are located outside the second contact elements, and are provided to frictionally contact the second contact elements; a pair of fourth contact elements formed of metal plates having a bifurcated tip and at least two vertices, positioned outside the third contact element and in frictional contact with the third contact element; and wherein the first contact element, the second contact element and the third contact element are capable of moving relatively toward and away from the electrode and the land while frictionally contacting each other; The elastic body is provided so as to surround a part of the fourth contact element, and elastically presses the first contact element against the land, and the second contact element, the third contact element and the fourth contact element. is configured by a coil spring that elastically presses against the electrode.

In the contact probe according to the present invention, the first contact terminal is further formed of a flat metal plate, has at least two vertices with a bifurcated tip, and is located outside the third contact element. A fourth contact element that is in frictional contact with the third contact element, and a planar metal plate having one vertex with a sharp tip, located inside the second contact element, a central center contact element that is in frictional contact with the second contact element and is provided between the electrode and the first contact element so as to be pressed toward the electrode by the first contact element; The contact elements and the central center contact element can move relatively toward and away from the electrode and the land while frictionally contacting the third contact element and the first contact element with each other.

The contact probe according to the present invention can obtain the following effects in addition to the effects described above. That is, by further adding a fourth contact element and the central center contact element, the second contact element, the third contact element, the fourth contact element and the central center contact element can be brought into contact with the electrode. Therefore, the number of contact elements that contact the electrodes can be increased, and the contact elements can be brought into contact with the electrodes more reliably by eliminating contact errors of the contact elements with the electrodes.

In the contact probe according to the present invention, it is provided so as to surround the tip of the second contact element and the tip of the third contact element close to the electrode, and the tip of the second contact element and the tip of the third contact element are provided. is further provided with a retaining member that retains it against radially outward movement.

The contact probe according to the present invention can obtain the following effects in addition to the effects described above. That is, the addition of the retaining member prevents the tip of the second contact element and the tip of the third contact element from moving radially outward, i.e. the tip of the second contact element and the tip of the third contact element. The tip of the second contact element and the tip of the third contact element are not loosened, and the contact force of the tip of the second contact element and the tip of the third contact element to the electrode is not reduced. It is possible to eliminate contact errors of the tip of the third contact element with the electrode. As a result, the tip of the second contact element and the tip of the third contact element can be reliably brought into contact with the electrode.

The contact probe according to the present invention further includes a holding member provided so as to surround the tip of the second contact element, the tip of the third contact element, and the tip of the fourth contact element that are close to the electrode. The holding member holds the tip of the second contact element, the tip of the third contact element and the tip of the fourth contact element against radially outward movement.

The contact probe according to the present invention can obtain the following effects in addition to the effects described above. That is, the addition of the retaining member prevents the tip of the second contact element, the tip of the third contact element and the tip of the fourth contact element from moving radially outward, i.e., the second contact element. The tip portion of the contact element, the tip portion of the third contact element and the tip portion of the fourth contact element are not separated, that is, the tip portion of the second contact element and the tip portion of the third contact element are separated. It can be made so as not to reduce the contact force to the electrode. As a result, the tip of the second contact element, the tip of the third contact element, and the tip of the fourth contact element can be reliably brought into contact with the electrode.

In the contact probe according to the present invention, the first contact element has at least both side surfaces thereof engaged with the lower portion of the coil spring to support the coil spring so as to protrude outward from the coil spring. The second contact element and the third contact element have element protrusions, and are formed on at least both side surfaces of the coil spring so as to protrude outward, and are biased toward the electrode by the coil spring. having a second contact element projection and a third contact element projection, the coil spring moved relative to the first contact element such that the second contact element and the third contact element approach the land When the second contact element protrusion and the third contact element protrusion are compressed by approaching the first contact element protrusion, the second contact element and the third contact element are separated from the land. When the first contact element is moved relative to such, the second contact element projection and the third contact element projection are extended by separating from the first contact element projection.

In the contact probe according to the present invention, the first contact element, the second contact element and the third contact element can slide independently of each other when the coil spring is compressed and expanded.

In the contact probe according to the present invention, the first contact element has at least both side surfaces thereof engaged with the lower portion of the coil spring to support the coil spring so as to protrude outward from the coil spring. The second contact element, the third contact element and the fourth contact element having element protrusions are formed on at least both side surfaces of the coil spring so as to protrude outward, and the coil spring allows the electrode to move. The coil spring has a second contact element projection, a third contact element projection and a fourth contact element projection which are biased sideways, wherein the coil spring is configured to extend between the second contact element, the third contact element and the fourth contact element. said first contact element protrusion and second contact element protrusion, said third contact element protrusion and said fourth contact element protrusion when said contact element moves relative to said first contact element to approach said land; When the first contact element is moved relative to the second contact element, the third contact element and the fourth contact element so that the second contact element, the third contact element and the fourth contact element are spaced apart from the land, the first contact element is compressed by moving the portions closer together. The contact element protrusion, the second contact element protrusion, the third contact element protrusion and the fourth contact element protrusion are separated from each other so as to be elongated.

In the contact probe according to the present invention, the first contact element, the second contact element, the third contact element and the fourth contact element can slide independently of each other when the coil spring is compressed and expanded. I'm trying
The contact probe according to the present invention can obtain the following effects in addition to the effects described above. That is, due to the action of elasticity of the coil spring, the apexes of the second contact element and the third contact element can follow the shape of the hemispherical tip while sliding independently of each other. It is possible to stably bring the second contact element and the third contact element into contact with the electrode while eliminating contact errors of the contact element and the third contact element with the electrode.

In the contact probe according to the present invention, the coil spring includes a densely wound portion wound around the third contact element and positioned between the densely wound portion and the distal end portion of the third contact element. , a first coarsely wound portion roughly wound around the tip of the third contact element; a second loosely wound portion that is roughly wound, wherein the second contact element and the third contact element have protrusions projecting outward from the first coarsely wound portion on at least both side surfaces thereof. , said second contact element and said third contact element are slidable independently of each other.

The contact probe according to the present invention can obtain the following effects in addition to the effects described above. That is, in the contact probe according to the present invention, the coil spring includes a densely wound portion wound around the fourth contact element and between the densely wound portion and the tip portion of the fourth contact element. a first loosely wound portion roughly wound around the tip portion of the fourth contact element; a second rough-wound portion roughly wound around the fourth contact element, wherein the fourth contact element has projections projecting outward from the first rough-wound portion on at least both side surfaces thereof; The contact element, said third contact element and said fourth contact element are adapted to slide independently of each other.

A test socket according to the present invention includes the contact probes described above, a housing formed with an accommodating portion for accommodating the contact probes, an object-to-be-tested holding portion for holding an object-to-be-tested provided with electrodes, and lands. a printed circuit board mounted on the contact probe, the electrode and land being located on the centerline of the contact probe.

BRIEF DESCRIPTION OF THE DRAWINGS It is the side view which showed 1st Example of the contact probe based on this invention, and was shown with the partial cross section. FIG. 2 is a view taken along the line AA in FIG. 1, showing the first embodiment of the contact probe according to the present invention; FIG. 2 is a view taken along line BB in FIG. 1, showing the first embodiment of the contact probe according to the present invention; 1 is a perspective view of a contact probe, showing the first embodiment of the contact probe according to the present invention; FIG. 1 is a plan view of a first contact element, a second contact element and a third contact element, which are constituent elements of the contact probe according to the present invention, showing the first embodiment of the contact probe according to the present invention; FIG. Figures 6A and 6B show a first embodiment of a contact probe according to the invention, Figure 6A showing the second and third contact elements when moved relative to the first contact element to approach the land. , the second contact element protrusion and the third contact element protrusion are compressed by approaching the lower first contact element protrusion by a distance S1, and FIG. 3 When the contact element moves relative to the first contact element such that it is separated from the lower first contact element projection by a distance S2, the second contact element projection and the third contact element projection move to the lower second contact element projection. An extended state is shown, extended by moving away from one contact element protrusion. FIG. 2 is a side view showing the first embodiment of the contact probe according to the present invention, showing that the coil spring, which is a constituent element of the contact probe, consists of a densely wound portion, a first coarsely wound portion and a second coarsely wound portion; be. 8A to 8D show the steps of inspecting the device under test using the contact probes of the first embodiment, FIG. 8A being the first step in which the device under test 2 is not attached to the contact probes, and FIG. 8B. 8C is the second step in which the device under test is attached to the contact probe, and FIG. Step 3 and FIG. 8D show the fourth step in which the device under test is further lowered to press the second and third contact elements and compress the coil spring. FIG. 2 is a side view showing a partial cross section of a second embodiment of a contact probe according to the present invention; FIG. 9 shows a second embodiment of the contact probe according to the present invention, taken along line CC of FIG. 9; FIG. 10 is a view taken along line DD of FIG. 9, showing a second embodiment of the contact probe according to the present invention; FIG. 2 is a perspective view of a contact probe, showing a second embodiment of the contact probe according to the present invention; FIG. 6 shows a second embodiment of the contact probe according to the present invention, and is a plan view of a first contact element, a second contact element, a third contact element and a fourth contact element, which are constituent elements of the contact probe. FIG. 13 is a cross-sectional view showing a third embodiment of a contact probe according to the present invention and showing an embodiment of a central center contact element 11b; FIG. 15 is a view taken along line EE of FIG. 14; FIG. 10 is a side view of a holding member that holds the tip of the second contact element and the tip of the third contact element so as not to come loose, showing the fourth embodiment of the contact probe according to the present invention; FIG. 15 is a side view of a holding member that shows the fifth embodiment of the contact probe according to the present invention and holds the tip of the second contact element, the tip of the third contact element, and the tip of the fourth contact element so as not to come apart; be.

An embodiment of the present invention will be described below with reference to the drawings.
First embodiment

FIGS. 1 to 5 show the contact probe of the first embodiment. In FIGS. 1 to 5, the contact probe 1 comprises solder balls 3 provided on a device under test 2 and lands provided on a printed circuit board 5. 4 are electrically connected. The solder balls 3 constitute electrodes in the present invention.

The contact probe 1 has a first contact terminal 6 that contacts the land 4, a second contact terminal 7 that contacts the solder ball 3, and is provided between the first contact terminal 6 and the second contact terminal 7. and an elastic body 15 for biasing the first contact terminal 6 and the second contact terminal 7 away from each other. The first contact terminal 6 and the second contact terminal 7 are housed inside the housing 8 . The contact probe 1 is positioned on the center line of the solder ball 3 and the land 4 during inspection of the device under test 2 .

The first contact terminal 6 is composed of a first contact element 11a made of a flat metal plate. The first contact element 11a has two first contact element protrusions 11ap on both sides thereof, ie, an upper part adjacent to the solder ball 3 and a lower part adjacent to the land 4, which are vertically separated from each other and formed to protrude on both sides. have. The first contact element 11a is housed in the housing 8 so that the upper first contact element protrusion 11ap can engage with the lower surface of the housing protrusion 8a formed on the upper portion of the housing 8. As shown in FIG. The lower first contact element protrusion 11ap supports the coil spring 16 by engaging with a lower engaging portion 16h of the coil spring 16, which will be described later.

Further, the second contact terminal 7 is formed of a flat metal plate, has at least two vertexes 12at with a bifurcated tip end, and sandwiches a part of the first contact element 11a to provide a first contact terminal. a pair of second contact elements 12a provided to frictionally contact the element 11a; and a pair of third contact elements 13a located on the outside and provided to frictionally contact the second contact elements 12a.

The second contact element 12a has second contact element protrusions 12ap on both sides thereof, ie, an upper portion adjacent to the solder ball 3 and a lower portion adjacent to the land 4, which are vertically separated from each other and protrude on both sides. The second contact element 12a is housed in the housing 8 so that the upper second contact element protrusion 12ap can engage with the lower surface of the housing protrusion 8a formed on the upper portion of the housing 8. As shown in FIG. The lower second contact element protrusion 12ap supports the coil spring 16 by engaging with a lower engaging portion 16h of the coil spring 16, which will be described later.

Similarly, the third contact element 13a has third contact element protrusions formed on both sides thereof, ie, an upper portion adjacent to the solder ball 3 and a lower portion adjacent to the land 4, which are vertically separated from each other and protrude to both sides. It has a portion 13ap. The third contact element 13a is housed in the housing 8 so that the upper third contact element protrusion 13ap can engage with the lower surface of the housing protrusion 8a formed on the upper portion of the housing 8. As shown in FIG. The lower third contact element protrusion 13ap supports the coil spring 16 by engaging with a lower engaging portion 16h of the coil spring 16, which will be described later.

The first contact element 11a, the second contact element 12a and the third contact element 13a are planar, as detailed in FIG. Therefore, the first contact element 11a, the second contact element 12a, and the third contact element 13a can be brought into frictional contact with each other in surface contact, and the solder ball 3 and the land 4 can be easily moved toward and away from each other. You can move to

The solder ball 3 has a hemispherical tip 3a that contacts the second contact element 12a and the third contact element 13a. The distance d between the vertices 12at of the second contact element 12a is smaller than the distance D between the vertices 13at of the third contact element 13a. Since the distance d between the apex 12at of the second contact element 12a and the distance D between the apex 13at of the third contact element 13a is set as described above, the apex 12at of the second contact element 12a and the apex 13at of the third contact element 13a are soldered together. The hemispherical tip 3a of the ball 3 can be sufficiently contacted and followed.

Also, the height h of the apex 12at of the second contact element 12a is made lower than the height H of the apex 13at of the third contact element 13a, so that the apex 12at of the second contact element 12a and the apex 13at of the third contact element 13a are equal to each other. There is a difference in height. Here, the height h of the apex 12at of the second contact element 12a is the length from the upper surface of the second contact element protrusion 12ap to the apex 12at, and the height of the apex 13at of the third contact element 13a. H is the length from the upper surface of the third contact element protrusion 13ap to the vertex 13at.

In addition to the effect of the difference between the distance d between the apexes 12at of the second contact element 12a and the distance D between the vertices 13at of the third contact elements 13a, the difference between the apexes 12at of the second contact elements 12a and the apexes 13at of the third contact elements 13a Due to the height difference of 13at, the apex 12at of the second contact element 12a and the apex 13at of the third contact element 13a can sufficiently contact and follow the hemispherical tip 3a of the solder ball 3. FIG.

The elastic body 15 is provided so as to surround a part of the third contact element 13a, and elastically presses the first contact element 11a against the land 4 and holds the second contact element 12a and the third contact element 13a as solder balls. It is composed of a coil spring 16 elastically pressed against 3. The coil spring 16 is housed in the housing 8 surrounding part of the third contact element 13a.

The coil spring 16 may be a uniform wire wound with the same winding pitch, or may be constructed as shown in FIG.

That is, as shown in FIG. 7, the coil spring 16 includes a densely wound portion 16a wound around the central portion of the third contact element 13a, and a close wound portion 16a and an upper side of the third contact element 13a. A first coarsely wound portion 16b positioned between the third contact element protrusions 13ap and roughly wound around the upper portion of the third contact element 13a, and a densely wound portion 16a and a second coil under the third contact element 13a. and a second loosely wound portion 16c located between the three contact element protrusions 13ap and roughly wound around the lower portion of the third contact element 13a.

The tightly wound portion 16a holds the first contact element 11a, the second contact element 12a and the third contact element 13a so that the first contact element 11a, the second contact element 12a and the third contact element 13a are not separated. , the first rough winding portion 16b and the second rough winding portion 16c bring the first contact element 11a, the second contact element 12a and the third contact element 13a into frictional contact with each other while bringing the first contact element 11a, the second contact element 12a and the third contact element 13a into contact with each other. The third contact elements 13a are held so as to slide independently of each other.

Furthermore, the coil spring 16 includes an upper engaging portion 16g that engages with the lower surfaces of the first contact element protrusion 11ap, the second contact element protrusion 12ap, and the third contact element protrusion 13ap, and the first contact element protrusion 11ap. , the second contact element projection 12ap, and a lower engaging portion 16h that engages the upper surfaces of the third contact element projection 13ap.

When the second contact element 12a and the third contact element 13a move relative to the first contact element 11a so that the second contact element 12a and the third contact element 13a are closer to the land 4, the coil spring 16 is adapted to the second contact element projection 12ap and the third contact element projection 13ap. is compressed by approaching the lower first contact element projection 11ap by a distance S1 (see FIG. 6A), and the second contact element 12a and the third contact element 13a are compressed from the lower first contact element projection 11ap. When the first contact element 11a moves away from the first contact element 11a by a distance S2, the second contact element protrusion 12ap and the third contact element protrusion 13ap are separated from the lower first contact element protrusion 11ap. decompressed (see FIG. 6B).

Thus, the compression of the coil spring 16 is performed by the solder ball 3 pressing the second contact element 12a and the third contact element 13a downward and moving them closer to the land 4. FIG. In addition, the extension of the coil spring 16 is performed by moving the solder ball 3 away from the land 4 by releasing the downward pressure on the second contact element 12a and the third contact element 13a.

Thus, when the coil spring 16 is compressed, the first contact element 11 a is elastically pressed against the land 4 and the second contact element 12 a and the third contact element 13 a are elastically pressed against the solder ball 3 . For this reason, the solder ball 3 is electrically connected to the land 4 through the first contact element 11a, the second contact element 12a and the third contact element 13a, that is, through the contact probe 1. A first contact element 11a, a second contact element 12a, a third contact element 13a and a coil spring 16 are arranged.

The contact probe of the first embodiment thus constructed has the following effects.

That is, two of each of the pair of second contact elements 12a and the pair of third contact elements 13a, that is, a total of eight vertices 12at and 13at, have different intervals and height differences as described above, and the tips of the solder balls 3 Since it is movable with respect to the portion 3a, the shape of the tip portion 3a of the solder ball 3 can be followed. The contact element 12a and the third contact element 13a can be brought into contact with the solder ball 3 stably.

8A to 8D show the steps of inspecting the device under test 2 using the contact probes 1 of the first embodiment, and FIG. 8B shows the second step in which the device under test 2 is mounted on the contact probe 1, and FIG. 8C shows the device under test 2 descending so that the solder balls 3 are in contact with the second contact element 12a and the third contact. The third step, which is in contact with the element 13a, and FIG. 8D are the fourth step, in which the device under test 2 descends further to press the second contact element 12a and the third contact element 13a, and the coil spring 16 is compressed. Show the process.

In the first step shown in FIG. 8A, the device under test 2 is not attached to the contact probes 1 . As shown, no further explanation is required.

In the second step shown in FIG. 8B, the device under test 2 is in a mounted state in which the contact probes 1 are mounted. Solder balls 3 of device under test 2 are located directly above contact probes 1 and lands 4, that is, directly above first contact element 11a, second contact element 12a and third contact element 13a.

In the third step shown in FIG. 8C, the solder ball 3 is in contact with the second contact element 12a and the third contact element 13a, so the second contact element protrusion 12ap and the third contact element protrusion 13ap are the same. Located at height.

Therefore, since the coil spring 16 remains stretched and uncompressed, the second contact element 12a and the third contact element 13a do not move relative to the first contact element 11a, i.e. remain stationary. . Therefore, the apex 12at of the second contact element 12a and the apex 13at of the third contact element 13a contact the tip 3a of the hemispherical solder ball 3. As shown in FIG. The top surface of the first contact element 11 a is separated from the tip 3 a of the solder ball 3 .

In the fourth step, the device under test 2 is further lowered to press the second contact element 12a and the third contact element 13a, and the coil spring 16 is compressed, so that the second contact element 12a and the third contact element 13a are compressed. move relative to the first contact element 11a against the coil spring 16 while being in frictional contact with each other, and the second contact element protrusion 12ap and the third contact element protrusion 13ap move relative to the first contact element protrusion 11ap. approaches up to a distance S1. That is, the first contact element 11 a is elastically pressed against the land 4 and the second contact element 12 a and the third contact element 13 a are elastically pressed against the solder ball 3 .

At this time, if the solder ball 3 is deviated from the contact probe 1, or if the center line of the solder ball 3 is not aligned with the center line of the contact probe 1 and is deviated, the vertex 12at of the second contact element 12a and the second contact element 12a A contact error occurs in which the apex 13at of the three-contact element 13a does not contact the tip 3a of the solder ball 3, and when the electrical characteristics of the semiconductor integrated circuit are tested, the second contact element 12a and the third contact element 13a are not connected to the solder ball. 3 may not be electrically connected.

However, since the contact probe 1 of the first embodiment is configured as follows, the apex 12at of the second contact element 12a and the apex 13at of the third contact element 13a are the tip portions 3a of the hemispherical solder balls 3. , and the second contact element 12a and the third contact element 13a are electrically connected to the solder ball 3 when testing the electrical characteristics of the semiconductor integrated circuit.
(1) The second contact terminal 7 is formed of a flat metal plate, has at least two vertices 12at with the tip being bifurcated, sandwiches a part of the first contact element 11a, and a pair of second contact elements 12a provided to frictionally contact the contact element 11a; and configured by a pair of third contact elements 13a provided to frictionally contact the second contact element 12a, the first contact element 11a, the second contact element 12a and the third contact element 13a can move relatively to and away from the solder ball 3 and the land 4 while being in frictional contact with the
(2) The solder ball 3 has a hemispherical tip 3a that contacts the second contact element 12a and the third contact element 13a, and the second contact element 12a and the third contact element 13a contact the solder ball 3, respectively. the second contact element 12a has at least two vertices 12at and 13at, the distance between the vertices 12at of the second contact element 12a being smaller than the distance between the vertexes 13at of the third contact element 13a;
(3) The height of the apex 12at of the second contact element 12a is lower than the height of the apex 13at of the third contact element 13a, and the height difference between the apex 12at of the second contact element 12a and the apex 13at of the third contact element 13a is is wearing

As a result, the second contact element 12a and the third contact element 13a can be stably brought into contact with the solder ball 3 without any mis-contact of the second contact element 12a and the third contact element 13a with the solder ball 3. . Therefore, the inspection function can be fully exhibited, and the reliability of the inspection socket can be improved.

Second Embodiment FIGS. 9 to 13 show a second embodiment of the contact probe.

In the contact probe of the second embodiment, as shown in FIGS. 9 to 13, the second contact terminal 7 further has a fourth contact element 14a.
The fourth contact element 14a is formed of a flat metal plate, has at least two vertices 14at with a bifurcated tip, is positioned outside the third contact element 13a, and is mutually connected to the third contact element 13a. , so as to move toward and away from the solder ball 3 while being in frictional contact with the solder ball 3 .

The fourth contact elements 14a are separated vertically from each other on both sides, i.e., the upper part close to the solder ball 3 and the lower part close to the land 4, similar to the shapes of the second contact element 12a and the third contact element 13a, It has fourth contact element protrusions 14ap formed to protrude on both sides. The interval Q (see FIG. 11) between the vertices 14at of the fourth contact element 14a is set larger than the interval D between the vertices 13at of the third contact element 13a. The height R (see FIG. 10) of the apex 14at of the fourth contact element 14a is set higher than the height H (see FIG. 10) of the apex 13at of the third contact element 13a. 12at, the vertex 13at of the third contact element 13a and the vertex 14at of the fourth contact element 14a are provided with a height difference, and the fourth contact element 14a is arranged with respect to the second contact element 12a and the third contact element 13a. Here, the height R of the apex 14at of the fourth contact element 14a is the length from the upper surface of the fourth contact element protrusion 14ap to the apex 14at. Therefore, the apex 12at of the second contact element 12a, the apex 13at of the third contact element 13a, and the apex 14at of the fourth contact element 14a can sufficiently follow the shape of the tip 3a of the solder ball 3. FIG.

As in the first embodiment, the coil spring 16 includes a densely wound portion 16a wound around the central portion of the fourth contact element 14a, and a densely wound portion 16a and a second coil spring above the fourth contact element 14a. A first loosely wound portion 16b positioned between the four contact element protrusions 14ap and loosely wound around the upper portion of the fourth contact element 14a, and a fourth tightly wound portion 16a and the fourth contact element 14a below the fourth contact element 14a. a second loosely wound portion 16c located between the contact element protrusions 14ap and loosely wound around the lower portion of the fourth contact element 14a.

The close-wound portion 16a is formed so that the first contact element 11a, the second contact element 12a, the third contact element 13a, and the fourth contact element 14a are not separated, 13a and a fourth contact element 14a, the first and second coarse turns 16b and 16c are connected to the first contact element 11a, the second contact element 12a, the third contact element 13a and the fourth contact element 13a. The first contact element 11a, the second contact element 12a, the third contact element 13a and the fourth contact element 14a are held so as to slide independently of each other while bringing the contact element 14a into friction contact.

In this manner, the elastic action of the coil spring 16 elastically presses the first contact element 11 a against the land 4 and causes the second contact element 12 a, the third contact element 13 a, and the fourth contact element 14 a to contact the solder ball 3 . It can be pushed elastically.

The effect of the second embodiment, in which the fourth contact element 14a is added to the first embodiment, is that the effect of the fourth contact element 14a is added to the effect of the first embodiment. Description is omitted below.

In addition, in the contact probe of the second embodiment, the number of contact elements to the solder ball 3 may be further increased, that is, may be increased to n. The number of contact elements increased to n can more reliably eliminate contact errors with the solder balls 3 .

Third Embodiment FIGS. 14 and 15 show a third embodiment of the contact probe.

In the contact probe according to the third embodiment, the first contact terminal 6 further has a central center contact element 11b, as shown in FIGS. 14 and 15. FIG. The central center contact element 11b is formed of a flat metal plate, is positioned inside the pair of second contact elements 12a, is in frictional contact with the second contact elements 12a, and is between the solder balls 3 and the first contact elements 11a. is provided above the first contact element 11a so as to be elastically pressed toward the solder ball 3 by the first contact element 11a.

A groove 11ab (see FIG. 14) is formed in the upper portion of the first contact element 11a to accommodate the lower portion of the central center contact element 11b. I do what I can. The fourth contact element 14a and the central center contact element 11b move relatively toward and away from the solder ball 3 and the land 4 while mutually frictionally contacting the third contact element 13a and the second contact element 12a, respectively. I have to.

The central center contact element 11b has two central center contact element protrusions 11bp formed to protrude from both sides thereof. The central center contact element protrusion 11bp is housed in the housing 8 so as to be able to engage with the lower surface of the housing protrusion 8a formed on the upper portion of the housing 8. As shown in FIG. The central center contact element protrusion 11bp is engaged with the upper engaging portion 16g of the coil spring 16. As shown in FIG.

Since the center contact element 11b is configured as described above, the device under test 2 is further lowered and the second contact element 12a and the third contact element 13a are pressed against the solder balls 3, as shown in FIG. 8D. Sometimes the central center contact element 11b can also compress the coil spring 16 together with the second contact element 12a and the third contact element 13a.

Therefore, the center center contact element 11b is also elastically pressed against the solder ball 3 together with the second contact element 12a and the third contact element 13a, and the apex 11bt of the center center contact element 11b is also pressed against the apex 12at and the second contact element 12a. Since the solder ball is pressed together with the apex 13at of the third contact element 13a, it is possible to stably contact the solder ball 3 without making contact errors with the solder ball 3 at all. Therefore, the inspection function can be fully exhibited, and the reliability of the inspection socket can be improved.
Fourth and fifth embodiments

16 and 17 show fourth and fifth embodiments of the contact probe, respectively.

Further, the contact probe of the fourth embodiment shown in FIG. 16 has a holding member 21 provided to surround the tip 12as of the second contact element 12a and the tip 13as of the third contact element 13a close to the solder ball 3. I have. The holding member 21 holds the distal end portion 12as of the second contact element 12a and the distal end portion 13as of the third contact element 13a so as not to move radially outward, that is, to prevent them from coming apart.

In addition, the contact probe of the fifth embodiment shown in FIG. It further comprises a holding member 21 provided to surround the . The holding member 21 prevents the distal end portion 12as of the second contact element 12a, the distal end portion 13as of the third contact element 13a, and the distal end portion 14as of the fourth contact element 14a from moving radially outward, that is, from separating. I try to keep it.

As described above, the contact probe according to the present invention is a contact probe for electrically connecting an electrode provided on a device under test and a land provided on a printed circuit board, and the contact probe contacts the land. one contact terminal, a second contact terminal in contact with the electrode, and a contact terminal provided between the first contact terminal and the second contact terminal so as to separate the first contact terminal and the second contact terminal. a biasing elastic body, wherein the first contact terminal is configured by a first contact element formed of a planar metal plate, and the second contact terminal is formed of a planar metal plate. a pair of second contact elements having at least two vertices with their tips bifurcated to sandwich a part of the first contact element and provided to frictionally contact the first contact element; A pair of second contact elements formed of a metal plate having a shape with a bifurcated tip end having at least two vertices, positioned outside the second contact element, and provided to frictionally contact the second contact element 3 contact elements, wherein the first contact element, the second contact element and the third contact element move relatively toward and away from the electrode and the land while frictionally contacting each other. The elastic body is provided so as to surround a part of the third contact element, and elastically presses the first contact element against the land and moves the second contact element and the third contact element to the electrode. Since the first contact element, the second contact element and the third contact element are in frictional contact with each other, they are opposed to the electrode and the land. can be physically moved closer together and further apart, increasing the number of contact elements to the electrode, the vertices of the second and third contact elements being the hemispherical tips of the electrodes. The shape can be satisfactorily followed, and contact errors with the electrodes can be completely eliminated. As a result, it is possible to reliably improve the inspection performance of the contact probe.

Further, in the contact probe according to the present invention, the electrode has a hemispherical tip that contacts the second contact element and the third contact element, and the second contact element and the third contact element each have The second contact element has at least two vertices in contact with the electrode, the distance between the vertices of the second contact element is smaller than the distance between the vertices of the third contact element, and the height of the vertices of the second contact element is the The apex of the second contact element and the third contact element are lower than the height of the third contact element so that the apex of the second contact element and the third contact element can follow the shape of the hemispherical tip of the electrode. Since the apexes of the contact elements are different in height, the apexes of the second contact element and the third contact element can better follow the shape of the hemispherical tip of the electrode, and the second contact element Further, the second contact element and the third contact element can be stably brought into contact with the electrode by further eliminating contact errors of the third contact element with the electrode.

Further, in the contact probe according to the present invention, the first contact terminal is further formed of a flat metal plate, the tip is bifurcated and has at least two vertices, and the third contact element A fourth contact element located outside the third contact element and in frictional contact with the third contact element, and a flat metal plate having one vertex with a sharp tip located inside the second contact element a central center contact element that is in frictional contact with the second contact element and is pressed toward the electrode by the coil spring between the electrode and the first contact element; The contact element and the central center contact element can move relatively toward and away from the electrode and the land while frictionally contacting the third contact element and the first contact element. A further increase in the number of contact elements to the electrode allows the vertices of the second and third contact elements to better follow the shape of the hemispherical tip of the electrode, thereby increasing the number of contact elements to the electrode. Contact errors can be completely eliminated. As a result, it is possible to reliably improve the inspection performance of the contact probe.

The contact probe according to the present invention and the test socket equipped with the same can sufficiently exhibit the test function by eliminating the contact error between the electrode and the top of the second contact terminal and achieving a perfect electrical connection between the electrode and the land. Since the reliability of the test socket can be improved by using the contact probe, it is useful as a contact probe and a test socket having the same.

1 contact probe 2 device under test 3 solder ball (electrode)
3a Tip of solder ball (electrode) 4 Land 5 Printed circuit board 6 First contact terminal 7 Second contact terminal 8 Housing 8a Housing projection 11a First contact element 11at Vertex 11ap of first contact element First contact element protrusion 11b central center contact element 11ab groove 11bt central center contact element apex 11bp central center contact element protrusion 12a second contact element 12at second contact element apex 12ap second contact element protrusion 12as tip of second contact element Part 13a Third contact element 13at Vertex 13ap of third contact element Projection part 13as of third contact element Tip part 14a of third contact element Fourth contact element
14at apex 14ap of fourth contact element projection 14as of fourth contact element distal end 15 of fourth contact element elastic body 16 coil spring 16a densely wound portion 16b first coarsely wound portion 16c second coarsely wound portion 16g upper portion of coil spring Engaging portion 16h Lower engaging portion 21 of coil spring Holding member

Claims (10)

A contact probe for electrically connecting an electrode provided on a device under test and a land provided on a printed circuit board,
a first contact terminal that contacts the land;
a second contact terminal contacting the electrode;
an elastic body provided between the first contact terminal and the second contact terminal for biasing the first contact terminal and the second contact terminal away from each other;
with
The first contact terminal is composed of a first contact element formed of a planar metal plate,
The second contact terminal is formed of a flat metal plate, has at least two vertices with a bifurcated tip, sandwiches a part of the first contact element, and is attached to the first contact element. A pair of second contact elements provided to frictionally contact each other, formed of a flat metal plate, having at least two vertexes with a bifurcated tip, located outside the second contact element, and a pair of third contact elements provided to frictionally contact the second contact elements, wherein the first contact element, the second contact element and the third contact element are in frictional contact with each other. capable of moving relatively toward and away from the electrode and the land;
The elastic body is provided so as to surround a part of the third contact element, and elastically presses the first contact element against the land and elastically pushes the second contact element and the third contact element against the electrode. It is composed of a coil spring that presses against the target ,
The electrode has a hemispherical tip that contacts the second contact element and the third contact element, each of the second contact element and the third contact element having at least two contact tips of the electrode. a contact probe having two vertices, wherein the distance between the vertices of the second contact element is smaller than the distance between the vertices of the third contact element . The electrode has a hemispherical tip that contacts the second contact element and the third contact element, each of the second contact element and the third contact element having at least two contact tips of the electrode. and the height of the apex of the second contact element is lower than the height of the third contact element to provide a height difference between the apex of the second contact element and the apex of the third contact element. The contact probe according to claim 1, characterized in that: The electrode has a hemispherical tip that contacts the second contact element and the third contact element, each of the second contact element and the third contact element having at least two vertices contacting the electrode. wherein the spacing between the vertices of the second contact elements is smaller than the spacing between the vertices of the third contact elements, the height of the vertices of the second contact elements is lower than the height of the third contact elements, and the A height difference is provided between the apex of the second contact element and the apex of the third contact element so that the apexes of the second contact element and the third contact element can follow the shape of the hemispherical tip of the electrode. The contact probe according to claim 1, characterized in that: A contact probe for electrically connecting an electrode provided on a device under test and a land provided on a printed circuit board,
a first contact terminal that contacts the land;
a second contact terminal contacting the electrode;
provided between the first contact terminal and the second contact terminal;
an elastic body that urges the second contact terminals apart;
with
The first contact terminal is composed of a first contact element formed of a planar metal plate,
The second contact terminal is formed of a flat metal plate, has at least two vertices with a bifurcated tip, sandwiches a part of the first contact element, and is attached to the first contact element. A pair of second contact elements provided to frictionally contact each other, formed of a flat metal plate, having at least two vertexes with a bifurcated tip, located outside the second contact element, a pair of third contact elements provided to frictionally contact the second contact elements; and a pair of fourth contact elements positioned outside of and in frictional contact with the third contact element, wherein the first contact element, the second contact element and the third contact element are in frictional contact with each other. while moving relatively toward and away from the electrode and the land;
The elastic body is provided so as to surround a part of the fourth contact element, and elastically presses the first contact element against the land, and the second contact element, the third contact element and the fourth contact element. Consists of a coil spring that elastically presses the element against the electrode,
The distance between the vertices of the fourth contact element is greater than the distance between the vertices of the third contact element, the height of the vertices of the fourth contact element is higher than the height of the third contact element, and the second contact The apex of the second contact element, the apex of the third contact element, the apex of the third contact element, and the apex of the fourth contact element can follow the shape of the hemispherical tip of the electrode. A contact probe, wherein the apex and the apex of the fourth contact element are different in height. The first contact terminal is further formed of a flat metal plate, has at least two vertices with a bifurcated tip, is located outside the third contact element, and is located outside the third contact element. and a fourth contact element that is formed of a flat metal plate, has one vertex with a sharp tip, is located inside the second contact element, and is in friction contact with the second contact element. , a center center contact element provided between the electrode and the first contact element so as to be pressed toward the electrode by the coil spring, wherein the fourth contact element and the center center contact element are: 2. The contact probe as set forth in claim 1, wherein said third contact element and said first contact element are in frictional contact with each other and can be moved relatively to and away from said electrode and said land. provided to surround the distal end of the second contact element and the distal end of the third contact element proximate to the electrode and to prevent the distal ends of the second contact element and the third contact element from moving radially outwards 2. A contact probe according to claim 1, further comprising a retaining member. The first contact element has first contact element protrusions on at least both side surfaces of the coil spring so as to protrude outward from the coil spring and engage with a lower portion of the coil spring to support the coil spring. The second contact element and the third contact element are formed on at least both side surfaces of the coil spring so as to protrude outward, and the second contact element protrusion and the third contact element are biased toward the electrode by the coil spring. a contact element protrusion, wherein the coil spring engages the second contact element protrusion when the second contact element and the third contact element are moved relative to the first contact element to approach the land; and the third contact element protrusion is compressed by approaching the first contact element protrusion, and the first contact element is opposed such that the second contact element and the third contact element are spaced apart from the land. 2. The contact according to claim 1, wherein the second contact element protrusion and the third contact element protrusion separate from the first contact element protrusion when the contact is moved by probe. 8. The apparatus according to claim 7 , wherein said first contact element, said second contact element and said third contact element are adapted to slide independently of each other during compression and expansion of said coil spring. Contact probe. The coil spring has a densely wound portion wound around the third contact element, and is positioned between the densely wound portion and the tip of the third contact element. and a second loosely wound portion positioned between the dense portion and the bottom of the first contact element and loosely wound around the bottom of the first contact element. and, the second contact element and the third contact element have projections projecting outward from the first coarsely wound portion on at least both side surfaces thereof, and the second contact element and the third 2. A contact probe according to claim 1, characterized in that the three contact elements are slidable independently of each other. a contact probe according to any one of claims 1 to 9 ;
a housing in which a storage portion for storing the contact probe is formed;
an object-to-be-inspected holder for holding the object to be inspected provided with the electrodes;
the printed circuit board provided with the land;
with
A test socket, wherein the electrode and the land are positioned on the centerline of the contact probe.

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