KR100817042B1 - Bellows type vertical micro contact probe - Google Patents

Abstract

The present invention relates to a vertical micro contact probe having a bellows shape for use in a probe card.

The vertical probe card used to electrically test whether the semiconductor chip is normally present has a structure in which the probe is erected in a vertical direction and fixed to the upper probe card body, and the lower probe end is in contact with the pad of the semiconductor chip. In addition, some contact force is required for complete electrical contact, and because it is vertical, it has a spring-type structure that can absorb deformation to overcome the step difference in the pad.

The present invention is characterized in that the probe is designed in a bellows shape in order to remove the stress concentration phenomenon that occurs when deformation occurs in the vertical probe.

Designing a vertical probe with a bellows shape allows the probe to be evenly stressed, thus meeting tens of thousands of repeat operations.

Probe, Fine Contact, Vertical, Bellows

Description

BELLOWS TYPE VERTICAL MICRO CONTACT PROBE}

1 is a perspective view of a cantilever type micro contact probe according to the prior art;

Figure 2a is a view showing a vertical micro contact probe having a simple spring shape of the basic type according to the prior art,

Figure 2b is a view showing a vertical micro contact probe having a simple spring shape of the parallel combination type according to the prior art,

3 is a view showing a stress distribution of a vertical micro-contact probe having a simple spring shape according to the prior art,

4 is a view showing a vertical micro contact probe having a bellows shape according to the present invention;

5a is a view showing a vertical micro contact probe having a bellows shape of a parallel combination according to the present invention;

5b is a view showing a vertical micro contact probe having an eccentric bellows shape according to the present invention;

6 is a view showing various bellows shapes of the vertical micro-contact probe according to the present invention.

The present invention relates to a vertical micro contact probe used in a probe card, and more particularly, to have a bellows shape so as to eliminate stress concentration occurring when deformation occurs in a vertical micro contact probe. A vertical micro contact probe is made.

With the recent development of technology, semiconductor chips are becoming more and more highly integrated. In general, the finished semiconductor chip is subjected to electrical inspection before it is packaged. According to the inspection result, the good product is packaged and the defective product is disposed of. This electrical test uses a probe card that makes electrical contact between the tester with built-in measuring device and the pad of the semiconductor chip.

Conventional line of center (LOC) type device measurement was performed by using a cantilever (Cantilever) type probe as shown in FIG.

However, current non-memory and communication fields use C4 (Controlled Collapse Chip Connection) type devices that can improve electrical performance and increase integration density, and the pad form of such C4 devices is generally an irregular two-dimensional array. Since the pitch between semiconductor chip pads is getting smaller due to the higher integration of semiconductor chips, a vertical fine contact probe is required to cope with this problem.

In general, the vertical micro-contact probe is limited in shape because it is manufactured by a semiconductor process such as electroplating. In addition, the probe should have a structure capable of absorbing the vertical displacement to overcome the step difference between the pads, and at the same time, the lateral force on the probe to remove the native oxide present on the electrode surface. It must be structured to create force).

In order to satisfy such a condition, a simple spring-shaped fine contact probe as shown in FIGS. 2A and 2B has been known as a general vertical probe. 2a shows a vertical micro contact probe with a simple spring shape of a basic type according to the prior art, and FIG. 2b shows a vertical micro contact probe with a simple spring shape of a parallel combination type according to the prior art.

However, such a conventional simple spring-shaped micro-contact probe has a structure that tends to buckling and stress concentration easily under compressive load, and thus plastic deformation easily occurs.

As shown in Figure 3, when looking at the stress distribution of the conventional simple spring-like micro-contact probe, the compressive stress acts on the inside of the spring structure while the tensile stress acts on the outside, the magnitude of the stress is stress concentration phenomenon Due to this, there was a problem that plasticity occurred far beyond the yield stress value.

SUMMARY OF THE INVENTION The present invention has been made to solve these conventional problems, and an object of the present invention is to make the vertical microcontact probe have a bellows shape so as to eliminate the stress concentration phenomenon generated when the vertical microcontact probe is deformed. It is intended to be.

According to an aspect of the present invention for achieving the above object, as a fine contact probe for performing an electrical inspection of the semiconductor chip, there is provided a fine contact probe having a bellows shape so that the concentration of stress during compression does not occur.

Here, it is preferable that fine contact probes having a plurality of bellows shapes are connected in parallel.

In addition, it is preferable that a tip contacting the electrode pad of the semiconductor chip protrudes at the end of the micro contact probe.

In addition, the tip is preferably located to one side rather than being located at the center of the micro-contact probe end.

The bellows of the micro contact probe may have any one shape selected from a nesting type, a flat plate type, a ripple type, a single sweep type, and a torus type. Can be.

According to another aspect of the present invention, a vertical micro-contact probe for performing an electrical inspection of the semiconductor chip, the micro-contact probe having a pair of bellows shape symmetrical in parallel to each other so that stress concentration and buckling does not occur during compression The micro contact probes connected in parallel are provided at the ends of the micro contact probes connected in parallel, and the vertical contact probes are provided to protrude from one side of the tip contacting the electrode pad of the semiconductor chip during measurement.

Hereinafter, the micro contact probe according to the preferred embodiment of the present invention will be described in detail with reference to FIGS. 4 to 6.

4 shows a vertical micro contact probe having a bellows shape according to a preferred embodiment of the present invention. 5A shows a vertical micro contact probe having a bellows shape of a parallel combination type according to the present invention, and FIG. 5B illustrates a vertical micro contact probe having an eccentric bellows shape according to the present invention.

As described above, the general spring-shaped vertical micro-contact probe shown in FIG. 2A has a problem in tens of thousands of repeated use because of plastic deformation due to stress concentration.

However, in the case of the bellows-shaped vertical micro contact probe of the present invention as shown in FIGS. 4, 5A and 5B, even when compressed in the vertical direction, the stress distribution is distributed evenly as a whole, and thus stress concentration does not occur. A stress relaxation effect can be obtained. In addition, even if the bellows shape to be produced by the electroplating method, there is no great difficulty.
As shown in Figures 4, 5A and 5B, the vertical micro-contact probe according to the present invention, the unit shape is repeatedly arranged along the longitudinal direction in the vertical direction, that is, the direction of the load is applied bellows shape such as corrugated pipe Has
4 shows the overall shape of a vertical micro contact probe according to the invention having a bellows shape. According to the present invention, the unit shape is formed by sequentially connecting a plurality of different patterns.
The unit shape may have various shapes as described below with reference to FIG. 6 in addition to the shape of the basic nesting type (or basic ripple type) shown in FIG. 4.

In general, vertical probes may cause buckling during compression (see FIG. 4), and when buckling occurs, interference with another adjacent probe may occur. In order to prevent the occurrence of buckling, as shown in Figure 5a, it is preferable to use a pair of bellows-shaped vertical micro-contact probes connected in parallel to each other in parallel. At this time, as shown in Figures 5a and 5b, a pair of bellows-shaped probes connected in parallel to each other in symmetry are integrated into a single vertical probe to deform together.

In this way, when a plurality of pairs of bellows-shaped probes are connected in parallel in a symmetrical manner, buckling can be prevented from occurring within design conditions.

As shown in Figure 5a, even if the vertical micro-contact probe having a bellows shape of the parallel combination symmetrical parallel connection is compressed, only the deformation in the vertical direction occurs but no buckling at all.

As shown in FIGS. 5A and 5B, a tip contacting the electrode pad of the semiconductor chip protrudes from the end of the vertical microcontact probe having the bellows shape of the parallel combination, that is, the upper end of the probe in the drawing.

In the case of FIG. 5A, since the tip of the probe is located at the center, no lateral force in the left and right directions occurs during compression of the probe, and only deformation in the vertical direction occurs.

In the case of FIG. 5B, since the tip of the upper end of the probe is not centered and eccentrically biased to one side, the tip is deformed in the vertical direction while compressing the probe, and a lateral force in the left and right directions is induced.

Accordingly, when the probe is compressed, the tip moves laterally on the electrode pad of the semiconductor chip, thereby removing a natural oxide film on the electrode pad, thereby enabling a more accurate test.

In FIG. 5B, the tip of the probe is positioned to the right side from the center when viewed in the drawing. When the probe is compressed, the bellows shape of the right side is more compressed than the left side. However, according to the vertical micro-contact probe having the bellows shape connected in parallel in the present invention, even if the probe is further compressed to either side, there is no buckling to interfere with another nearby probe.

The bellows shape of the vertical micro contact probe according to the present invention is shown in FIG. 6 in addition to the shape of the basic nesting type (or basic ripple type) shown in FIGS. 4, 5A and 5B. It may have various shapes as shown.

6 (a) shows a flat plate type bellows shape, FIG. 6 (b) shows a ripple type bellows shape, and FIG. 6 (c) shows a single sweep type. The bellows shape, and in Figure 6 (d) is shown a torus type bellows shape. In the present invention, the bellows of various shapes can be applied to the micro contact probe.

While the invention has been described above with reference to specific embodiments, various modifications, changes, or modifications may be made in the art within the spirit and scope of the appended claims, and thus, the foregoing description and drawings illustrate It should be construed as illustrating the present invention, not limiting the technical spirit of the invention.

According to the present invention as described above, the vertical micro-contact probe has a bellows shape, it is possible to eliminate the stress concentration phenomenon that occurs when the vertical micro-contact probe deformation occurs.

In other words, when the vertical micro contact probe is designed in a bellows shape, the probe can be evenly stressed, thereby satisfying tens of thousands of repeated operations, and flexibly coping with the step of the pad.

In addition, according to the present invention, there is provided a vertical micro-contact probe having a bellows shape of the parallel structure, so that buckling does not occur within the design range.

In addition, according to the present invention, by setting the position of the tip formed at the end of the probe in contact with the electrode pad of the semiconductor chip so as to be eccentric from the center, it is possible to remove the natural oxide film on the electrode surface during compression of the probe to enable more accurate measurement.

Claims (6)

A micro contact probe for performing an electrical inspection of a semiconductor chip, The micro-contact probe has a bellows shape in which unit shapes are repeatedly arranged along a direction in which a load is applied, and the unit shape is formed by sequentially connecting a plurality of different patterns, so that concentration of stress does not occur during compression. Micro-contact probe, characterized in that not. The method according to claim 1, And a pair of the microcontact probes having a bellows shape are symmetrically connected in parallel to each other to form a microcontact probe. The method according to claim 1 or 2, And a tip contacting the electrode pad of the semiconductor chip at the end of the micro contact probe to protrude. The method according to claim 3, And the tip is not located at the center of the microcontact probe end but is biased to one side. The method according to claim 1 or 2, The bellows of the micro contact probe has a shape selected from a nesting type, a flat plate type, a ripple type, a single sweep type, and a torus type. Micro-contact probe, characterized in that. A vertical micro contact probe for performing an electrical inspection of a semiconductor chip, In order to prevent stress concentration and buckling during compression, a pair of the micro-contact probes having a bellows shape in which unit shapes are repeatedly arranged along a load direction are integrally connected in parallel in a symmetrical manner, And a tip contacting the electrode pad of the semiconductor chip to the side of the micro-contact probe connected in parallel to be protruded to one side.

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