KR102213594B1 - MEMS Kelvin test socket - Google Patents

Abstract

The present invention relates to a MEMS Kelvin test socket, comprising: a Kelvin test socket for measuring current and voltage between a conductive ball of a semiconductor device and a two-terminal contact pad of a test device, wherein the first contact pad is connected to an upper conductive ball and is A first Kelvin spring pin connected to and, a second Kelvin spring pin connected to the conductive ball on the upper side, and connected to a second contact pad on the lower side, and the first Kelvin spring pin and the second Kelvin spring pin are parallel. It includes a socket block installed to be symmetrical to each other, wherein the first top plunger of the first Kelvin spring pin and the second top plunger of the second Kelvin spring pin are arranged in parallel with each other, and the space of the upper portion compared to the lower portion of the arrangement state It is narrower, and includes probes located at the ends of the upper surface adjacent to each other and contacting the same conductive balls, respectively.

Description

MEMS Kelvin test socket

The present invention relates to a MEMS Kelvin test socket, and in more detail, in a Kelvin test socket in which two pins are in contact with one ball, the gap between the probes of the tip of the pins facing each other implements a fine pitch of 50 μm. It relates to a MEMS Kelvin test socket employing a MEMS process in which the outermost end of the barrel is provided to extend outside the outer diameter of the barrel, and for this purpose, precision machining of the probe is easy.

In general, among tests of integrated circuits such as semiconductors, the Kelvin test is to accurately measure the resistance of an integrated circuit element. In general, current and voltage are measured by contacting two contact terminals with a conductive ball of an integrated circuit. To measure the resistance of the integrated circuit device.

1 is a diagram showing the concept of a typical Kelvin test. Referring to FIG. 1, two contact terminals each contact different points on both pads (pad A and pad B) of an element to be inspected to measure current and voltage to measure resistance of an element to be inspected.

The Kelvin test probe is typically a Pogo-pin type probe.

Referring to FIG. 2, in the conventional Kelvin test probe 2, a pair of probes 10a and 10b are arranged opposite, and each probe has a plunger 10 and a plunger 10 in contact with the contact portion of the semiconductor lead. It consists of a cylindrical barrel 30 coupled to, an elastic spring 20 accommodated in the barrel 30 to provide an elastic force, and a contact pin 40 coupled to the lower portion of the barrel 30. The conventional Kelvin test probe 2 as described above is installed in a Kelvin test socket and is finally applied to inspection of a semiconductor device.

However, the Kelvin test probe 2 according to the prior art has the following problems.

First, in the case of a pogo-pin type Kelvin test probe, there is a limitation in reducing the pitch between two terminals due to the cylindrical barrel structure accommodating the elastic spring 20 and the structural characteristics of the elastic spring itself.

In particular, in recent years, at a point in time when the pitch between the leads of the semiconductor devices is gradually decreasing due to the gradual high integration of semiconductor devices, the pogo-pin type Kelvin test probe is difficult to reduce the size of the plunger 10 itself. There is a problem that cannot cope with the high integration of

Second, even if the size of the plunger 10 is reduced, the outermost end of the probe 12 at the tip does not exceed the outer diameter of the barrel 30.

For example, it is difficult to manufacture the probe 12 eccentric at the tip of a cylindrical shape by a conventional turning process (for example, a cutting process in which a workpiece is rotated with a lathe and a steel cutting tool is placed on it and cut into a cylindrical or conical shape). There is a limit that the degree cannot be extended beyond the outer diameter of the barrel 30.

That is, the distance r1 between the outer diameters of the neighboring barrels 30 is narrower than the distance r2 between the probes, so that the distance r2 between the eccentric probe and the probe cannot be reduced.

Accordingly, in the case of the cylindrical pogo-pin, since the probe 12 does not exceed the outer diameter of the barrel 30, there is a physical limitation in narrowing the gap between the adjacent tip and the tip.

Korean Patent Publication 10-2009-0118319

Accordingly, the present invention was conceived to solve the problems of the prior art as described above, and an object of the present invention is to provide a MEMS Kelvin test socket for changing a cylindrical plunger to a strip-shaped MEMS plunger.

Another object of the present invention is to provide a MEMS Kelvin test socket in which the tip of the probe extends to the other barrel beyond the limit of the outer diameter of one barrel to minimize the gap between the probes.

The present invention for solving the above problems is a Kelvin test socket for measuring current and voltage between a conductive ball of a semiconductor device and a two-terminal contact pad of a test device, and is connected to the conductive ball at the top and a first contact at the bottom. A first Kelvin spring pin connected to a pad, a second Kelvin spring pin connected to the upper conductive ball and connected to a second contact pad at the bottom, and the first Kelvin spring pin and the second Kelvin spring pin are parallel. And a socket block installed symmetrically to each other, wherein the first top plunger of the first Kelvin spring pin and the second top plunger of the second Kelvin spring pin are arranged parallel to each other, and the gap between the upper portion compared to the lower portion of the arrangement state It is narrower and includes probes that are located at the ends of the upper surface adjacent to each other and contact each of the same conductive balls.

In one embodiment of the present invention, the first and second Kelvin spring pins are respectively installed at the top of the first and second barrels and the first and second barrels having a cylindrical shape, and the first and second barrels The first top plunger and the second top plunger in the form of a strip that is movably installed therein, and the first and second top plungers are respectively installed at the bottom of the first and second barrels, and are movably installed inside the first and second barrels. It includes first and second bottom plungers, and first and second coil springs installed between the first and second top plungers and the first and second bottom plungers.

In one embodiment of the present invention, in the first and second top plungers, the first width w1 between the first and second surfaces substantially matches the inner diameters of the first and second barrels, and the The probe in direct contact with the conductive ball includes a connection tip formed at an end of the third surface extending further by a second width w2 from the second surface, and a neck forming a step smaller than the first width w1 , Substantially the same as the first width w1, and may include a slide that is supported by the first and second coil springs and moves inside the first and second barrels.

In one embodiment of the present invention, the second width w2 may be 1/3 or more to 1/2 or less of the first width w1.

In one embodiment of the present invention, the distance d between the opposed probes may be smaller than the first width w1.

In one embodiment of the present invention, the socket block has socket holes arranged side by side so that the first and second Kelvin spring pins can be installed symmetrically to each other, and the first And a guide plate for guiding the slides of the first and second top plungers to prevent the second Kelvin spring from being separated from the socket hole, and a slot corresponding to the connection tip in the length direction. Can be arranged.

As described above, according to the configuration of the present invention, the following effects can be expected.

First, since the plunger is manufactured through a MEMS process, a press process, or an etching process, precision processing is possible, and it is particularly suitable for narrowing the gap between the plungers, and has the advantage of enabling mass production.

Second, since the probe is processed through the MEMS process, the spacing between adjacent pitches can be limited to within 50㎛, which is suitable for fine pitch.

Third, even if an error occurs between the inner diameter of the barrel and the outer diameter of the plunger, the slide is elastically deformed outward due to the pressure of the coil spring, so that the connected state is maintained, and when the pressure is released, it quickly returns to the original position. The reliability of the inspection is high.

1 is a conceptual diagram showing a Kelvin test according to the prior art.
2 is a perspective view showing a Kelvin test probe according to the prior art.
3 and 4 are a front cross-sectional view and a side cross-sectional view respectively showing the configuration of the Kelvin test socket according to the present invention.
5 to 8 is a perspective view, an exploded perspective view, a front cross-sectional view, and a side cross-sectional view respectively showing the configuration of the MEMS Kelvin spring pin according to an embodiment of the present invention.
9 to 13 are a perspective view, an exploded perspective view, a front cross-sectional view, a side cross-sectional view, and a partial enlarged view each showing the configuration of a MEMS Kelvin spring pin according to another embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity of description. The same reference numerals refer to the same components throughout the specification.

Embodiments described in the present specification will be described with reference to a plan view and a cross-sectional view which are ideal schematic diagrams of the present invention. Accordingly, the shape of the exemplary diagram may be modified by manufacturing technology and/or tolerance. Accordingly, embodiments of the present invention are not limited to the specific form shown, but also include a change in form generated according to the manufacturing process. Accordingly, the regions illustrated in the drawings have schematic properties, and the shapes of the regions illustrated in the drawings are intended to illustrate a specific shape of the region of the device, and are not intended to limit the scope of the invention.

Hereinafter, a preferred embodiment of the Kelvin test socket according to the present invention having the configuration as described above will be described in detail with reference to the accompanying drawings.

The present invention relates to an apparatus for measuring a two-terminal circuit by Kelvin connection, wherein a probe of a current supply circuit and a probe of a voltage measurement circuit are connected to each terminal of a two-terminal circuit, and the resistance of the current supply circuit and the voltage measurement circuit or each probe It includes a pair of Kelvin spring pins arranged parallel and symmetrically to each other so that measurements of a two-terminal circuit can be performed without being affected by the contact resistance between the and terminals.

A pair of Kelvin spring pins are connected at the upper end of each end to the ball electrode at the same time, and the lower end of each end are independently connected to the two terminal contact pads of the test apparatus. Accordingly, the configuration of the upper tip portion connected to the ball electrode and the lower tip portion connected to the contact pad may be different.

However, since the two distal ends form a contact on one conductive ball, the distal ends may have directionality to face each other by a guide.

In order to correspond to a fine pitch, the spacing between the pair of tip portions may be adjusted so as not to exceed 50 μm. The present invention is very advantageous in processing such a plunger with MEMS and adjusting the spacing compared to a conventional circular pin.

3 and 4, the Kelvin test socket 1000 is a Kelvin test socket for measuring current and voltage between a conductive ball B of a semiconductor device and two terminal contact pads P1 and P2 of a test device. , The same as the first Kelvin spring pin 100 and the first Kelvin spring pin 100 connected to the upper conductive ball (B) and connected to the lower first contact pad (P1), and the upper conductive ball (B ) And the second Kelvin spring pin 200 connected to the lower second contact pad P2, and the first and second Kelvin spring pins 100 and 200 in parallel and symmetrically installed sockets Including block 300.

5 to 8, the first Kelvin spring pin 100 is installed on the top of the cylinder-shaped first barrel 110 and the first barrel 110, respectively, and is movably installed therein. A type of MEMS first top plunger 120, a first bottom plunger 130 installed at the bottom of the first barrel 110 and movably installed therein, and a first top plunger 120 and a first It includes a first coil spring 140 installed between the bottom plunger 130.

The second Kelvin spring pin 200 has the same configuration as the first Kelvin spring pin 100. That is, the second Kelvin spring pin 200 includes a second barrel 210 in a pipe shape, a second top plunger 220 in a strip shape and a second barrel 210 installed on the top of the second barrel 210, respectively. ) And a second bottom plunger 230 installed at the bottom, and a second coil spring 240 installed between the second top plunger 220 and the second bottom plunger 230.

However, the first and second Kelvin spring pins 100 and 200 may be installed to face each other in the socket block 300.

As described above, the Kelvin spring pins 100 and 200 of the present invention include the first and second top plungers 120 and 220 and the first and second bottom plungers 130 at both ends of the first and second barrels 110 and 210. 230) is a double type that is slidably assembled, but may be provided in a single type in which only the first and second top plungers 120 and 220 are slidably assembled. Further, only the first and second top plungers 120 and 220 are of a MEMS type, and the first and second bottom plungers 130 and 230 are of a circular column type, but may also be provided in the same MEMS type.

Each of the first and second barrels 110 and 210 is mounted on the socket block 300 and has an empty cylindrical or cylindrical shape. Each of the first and second barrels 110 and 210 accommodates each coil spring 140 and 240 therein, and both ends are open, and at both ends, round caulking or roll caulking that is bent inward so that both plungers are not separated. More can be provided. Round caulking may be rounded inward by applying pressure to the ends of the first and second barrels 110 and 210 using a press.

The MEMS top plungers 120 and 220 of the present invention form a contact with the conductive ball B, and form a strip through a MEMS process, a press process, or an etching process. Can be provided as

Specifically, in the first top plunger 120, the first width w1 between the first surface S1 and the second surface S2 substantially coincides with the inner diameter of the first barrel 110, and the conductive ball The probe in direct contact with (B) is greater than the connection tip 122 and the first width w1 formed at the end of the third surface S3 extending from the second surface S2 by the second width w2. Includes a neck 124 forming a small step, and a slide 126 that is substantially the same as the first width w1 and moves inside the first barrel 110 while being supported by the first coil spring 140 do.

The second width w2 may extend in a range of 1/3 or more to 1/2 or less of the first width w1. For example, if the first width w1 is 0.140 mm, the second width w2 may be provided as 0.057 mm.

The distance d between the opposing probes 122a and 220a is smaller than the first width w1.

First of all, according to the embodiment of the present invention, since the connection tip 122 is provided in a strip shape through the MEMS process, width processing is easy, and thus the third surface S3 is formed through the second width w2. Since it is extended to the outside of the outer diameter of the one barrel 110, the distance d between the probes may be provided with a minimum distance corresponding to the fine pitch.

When the top plungers 120 and 220 are manufactured using the MEMS process as described above, the processing of the contact tips 122 and 222 forming contact with the conductive ball B in the top plunger becomes more detailed. In particular, in the case of the Kelvin spring pin, since a pair of linearly symmetric connection tips protrude from both ends rather than the center, processing of the protruding region is more important. In addition, according to the MEMS process, the surface of the top plungers 120 and 220 may be plated with various alloys to secure conductivity.

When the top plunger 120 in contact with the conductive ball B is provided in a substantially two-dimensional strip shape compared to the three-dimensional rod shape, since it is formed in a plate shape having a predetermined thickness, MEMS & Press ) It has the advantage that continuous production is possible using the process and precision processing is guaranteed.

That is, if the top plungers 120 and 220 are manufactured using a MEMS (Micro Electro Mechanical System) process, it is possible to precisely manufacture the top plunger and contribute to mass production.

The first bottom plunger 130 is connected to the contact pads P1 and P2 of the test apparatus. It may include a cylindrical connection pin.

Referring again to FIGS. 3 and 4, the socket block 300 has socket holes 310 arranged side by side so that the first and second Kelvin spring pins 100 and 200 can be installed symmetrically to each other, At the top and bottom of the socket block 300, the first and second Kelvin springs 100 and 200 are prevented from being separated from the socket hole 310, and the slides of the first and second top plungers 120 and 220 are guided. The guide plate 320 may be further installed.

Slots corresponding to the cross-sectional shape of the connection tip 122 are arranged in the length direction on the guide plate 320. That is, the slots may be arranged in the longitudinal direction. By means of the slot, the connection tip 122 may be disposed so that the tip ends face each other in a direction opposite to each other despite rotation.

9 to 12, the first and second Kelvin spring pins 600 and 700 are rolled on top of the pipe-shaped first and second barrels 610 and 710, and the barrels 610 and 710. ) Caulked, strip-shaped MEMS first and second top plungers 620 and 720, which are movably installed inside the barrels 610 and 710, and rolled at the bottom of the barrels 610 and 710, and the barrel (610, 710) MEMS first and second bottom plungers (630, 730) in the form of a strip that is movably installed inside, and a first installed between the top plungers (620, 720) and the bottom plungers (630, 730). It includes first and second coil springs 640 and 740.

Rolling (rolling) caulking is characterized in that one side of the center of the barrels (610, 710) is caulked. For example, when one of the barrels 610 and 710 is fixed and the other side of the barrels 610 and 710 is mechanically pressed using a rolling coating means, and the barrels 610 and 710 are rotated, rolling caulking can be formed. have.

The MEMS first top plunger 620 includes a connection tip 622, a neck 624, and a slide 626. The connection tip 622 has a first width w1 between the first surface S1 and the second surface S2 substantially coinciding with the inner diameter of the first barrel 610, and directly contacts the conductive ball B The probe is formed at the end of the third surface S3 extending from the second surface S2 by a second width w2. The neck 624 forms a step smaller than the first width w1. The slide 626 is substantially the same as the first width w1 and is supported by the first coil spring 640 and moves inside the first barrel 610.

Referring to FIG. 13, when pressure is applied from the lower portion of the slide 626 by the recess, the outer diameter of the slide 626 must be expanded by the recess. For example, since the central part has been removed by the recess, it has elastic force on both sides when pressed. Therefore, when the slide 626 descends while receiving a force from the lower portion, the elastic pieces of the slide 626 spread to both sides, so as to be in close contact with the inner diameter of the barrel 610 and the electrical connection area is enlarged.

If a recess is not provided in the slide 626 or the slide 626 has a three-dimensional shape other than a MEMS strip shape, the outer diameter cannot be enlarged to both sides even when a force is applied. On the other hand, when the slide 626 of the present invention has an action reaction with the coil spring 640 of the lower portion, the degree of spreading to both sides increases in proportion to this.

As such, when the pair of elastic pieces are spread on both sides, the outer diameter of the slide 626 becomes the same as the inner diameter of the barrel 610, and a strong contact force is generated between the outer diameter of the top plunger 620 and the inner diameter of the barrel, so that the connection ability is increased. Improves. As the connection ability is improved, an electrical path leading from the barrel 610 to the top plunger 620 is formed, electrical resistance is lowered, and reliability of inspection may be increased.

As a result, even when the gap between the inner diameter of the barrel 610 and the outer diameter of the top plunger 620 is separated by more than an allowable error, since the outer diameter of the top plunger 620 is expanded during the sliding operation, the connection capability can be maintained.

On the contrary, even if the gap between the inner diameter of the barrel 610 and the outer diameter of the top plunger 620 is smaller than the allowable error, even if the outer diameter of the top plunger 620 contacts the inner diameter of the barrel 610, the slide 626 is moved inward by the recess. Because it shrinks, there is no obstacle to the slide movement.

That is, according to the embodiment of the present invention, there is an advantage in that the tolerance range is flexible, so that contact characteristics can be maintained regardless of errors. In addition, the slide 626 is restored to the inside when the pressure by the coil spring 640 is released, so that the slide operation should be made smoothly.

In addition, an elastic tip extending to an inner diameter of the barrel 610 may be provided at an end of the elastic piece. In particular, an elastic tip that extends further outside the top plunger 620 may be further provided at the end of the slide 626.

In addition, the bottom surface of the elastic tip is rounded upward for smooth contact with the coil spring 640. When receiving pressure by contacting the end of the coil spring 640, there is a reason for the bottom surface of the elastic tip to have an inclined surface to convert the pressure in the lateral direction. At the same time, the upper end of the coil spring 640 may also be convex to correspond to the inclined surface.

As described above, the present invention provides the outermost end of the probe to extend outside the outer diameter of the barrel in order to realize a fine pitch of 50 μm between the probes of the front ends facing each other. It can be seen that the construction employing an easy MEMS process is considered as a technical idea. Within the scope of the basic technical idea of the present invention, many other modifications may be made to those of ordinary skill in the art.

100: first Kelvin spring pin 110: first barrel
120: first top plunger 130: first bottom plunger
140: first coil spring 200: second Kelvin spring pin
210: second barrel 220: second top plunger
230: second bottom plunger 240: second coil spring

Claims (6)

As a MEMS Kelvin test socket that measures current and voltage between a conductive ball of a semiconductor device and a two-terminal contact pad of a test device,
A first Kelvin spring pin connected to the upper conductive ball and connected to the lower first contact pad,
A second Kelvin spring pin connected to the upper conductive ball and connected to the lower second contact pad, and
And a socket block in which the first Kelvin spring pin and the second Kelvin spring pin are installed in parallel and symmetrically to each other,
The first top plunger of the first Kelvin spring pin and the second top plunger of the second Kelvin spring pin are arranged parallel to each other, and the gap between the upper portions is narrower than that of the lower portion of the arrangement state, and are located at the ends of the upper surface adjacent to each other. MEMS Kelvin test sockets with probes each contacting the same conductive ball. The method of claim 1,
The first and second Kelvin spring pins,
First and second barrels having a cylindrical shape;
The first and second top plungers in the form of strips respectively installed on upper ends of the first and second barrels and movably installed in the first and second barrels;
First and second bottom plungers respectively installed below the first and second barrels and movably installed inside the first and second barrels; And
MEMS Kelvin test socket, comprising: a first and second coil springs installed between the first and second top plungers and the first and second bottom plungers. The method of claim 2,
The first and second top plungers,
A first width (w1) between the first and second surfaces coincides with the inner diameters of the first and second barrels, and the probe directly in contact with the conductive ball is a second width (w2) from the second surface. A connection tip formed at an end portion of the third surface that is further extended by the amount;
A neck forming a step smaller than the first width w1; And
The MEMS Kelvin test socket, characterized in that it comprises a slide equal to the first width w1 and supported by the first and second coil springs and moving inside the first and second barrels. The method of claim 3,
The second width (w2) is the MEMS Kelvin test socket, characterized in that 1/3 or more to 1/2 or less of the first width (w1). The method of claim 3,
MEMS Kelvin test socket, characterized in that the gap (d) between the opposed probes is smaller than the first width (w1). The method of claim 3,
The socket block has socket holes arranged side by side so that the first and second Kelvin spring pins can be installed symmetrically to each other,
Guide plates are further installed at the upper and lower portions of the socket block to prevent the first and second Kelvin springs from being separated from the socket hole, and to guide the slides of the first and second top plungers,
The MEMS Kelvin test socket, characterized in that the slots corresponding to the connection tips are arranged in the longitudinal direction on the guide plate.

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