JPH04360549A - High density probe card - Google Patents

Abstract

PURPOSE:To increase the geometrical moment of inertia of a probe needle so that a sufficiently high probe pressure can be obtained and probe needle arranging density per layer can be improved, by making the length of the trans verse cross section of the probe needle in the direction perpendicular to the surface of a water larger than the one in the direction parallel to the surface of the wafer. CONSTITUTION:The cross section of a prove needle is circular at the base end 7 and is about 0.2-0.4mm in diameter. The length (b) of the cross section in the direction parallel to the surface of a water is gradually reduced toward its tip from its barrel section 8. On the other hand, the length (h) of cross section in the direction perpendicular to the surface of the water at the barrel section 8 is larger the one at the base end and gradually decreases in the tapered section 9. In addition, the needle is formed so that the needle can have a transverse cross section whose length (b) in the horizontal direction is remarkably smaller than the length (h) in the vertical direction. Therefore, the probe arranging density per layer can be increased, because the geometrical moment of inertia of the needle can be increased and a sufficiently high prove pressure can be obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe card for testing integrated circuits constructed on semiconductor wafers.

0002

[Prior Art] As shown in Japanese Utility Model Publication No. 59-762, for example, a conventional probe card has a terminal connected to a prober (inspection machine main body) on one side of a rectangular printed wiring board, and an inspection terminal in the center of the board. An opening window is formed to observe the electrode on the wafer and the tip of the probe needle.
It has a structure in which a probe needle is arranged around it, and the shape of the probe needle is as shown in Figure 5. was circular.

0003

[Problems to be Solved by the Invention] As the degree of integration of integrated circuits increases, the number of test electrodes also increases, and the multilayer probe needle structure described in the conventional example has three to four layers, and the thickness of the body of the probe needle increases. The diameter is 0.2mm, and the number of probe needles is 30.
It has reached 0 to 500 books. Even in the above-mentioned overcrowded state, a predetermined probe pressure is required for all probe needles during probing when the probe needles are in contact with the electrodes.
If the probe diameter is made as thin as 0.16 mm, even if the arrangement density can be increased, a predetermined probe pressure cannot be obtained.

Even under these circumstances, there is still a strong demand for increased overdensity by increasing the pitch of electrode pads to be inspected from 100 microns to 60 microns and further to 50 microns. The present invention was made in order to meet the demand for increased overdensity under such extreme conditions.

[0005]

[Means for Solving the Problems] In the high-density probe card of the present invention, the cross-sectional shape of at least the portion from the tip to the body of the probe needle is non-circular, and the surface of the integrated circuit wafer is in contact with the surface of the integrated circuit wafer. It is characterized by a substantially rectangular shape whose length in the parallel direction is smaller than the length in the direction perpendicular to the surface of the integrated circuit wafer.

[0006]

[Operation] The probe card is mounted on an automatic measuring machine, displaced by a predetermined stroke, and pressed onto the wafer. When the material is constant and the distance from the probe base to the tip of the probe needle is constant, if you want to obtain a predetermined probe pressure,
A certain moment of inertia of area is required. In the present invention, the length in the direction perpendicular to the wafer surface (vertical dimension h) of the cross-sectional shape of the probe needle is larger than the length in the direction parallel to the wafer surface (lateral dimension b), so the second moment of area is large. As a result, a sufficient probe pressure can be obtained, and since the lateral dimension b is small, the density of probe needles per layer can be greatly improved compared to the prior art.

[0007]

Embodiment FIG. 1 shows a sectional view of an embodiment of the present invention. A circular or rectangular opening 2 is formed in the center of the printed wiring board 1, and integrated circuit wafers 3 to be inspected are sequentially supplied below this opening 2, and around the opening 2 on the lower surface of the wiring board 1. A probe stand 4 made of metal, plastic or ceramic is fixed to the probe stand 4, and the bodies of single-layer or multi-layer probe needles 5 are adhered and held on the probe stand 4.
The base end of each probe needle 5...5 is connected to the printed wiring on the board 1, and the tip 6 of each probe needle 5...5 is bent downward into a hook shape, and the tip is attached to the wafer. It is adjusted to be on the same plane so that it comes into contact with the electrode pads.

FIG. 2 shows a perspective view of the probe needle 5, and FIG.
2 shows its plan view, side view, and cross-sectional view of each part. The proximal end 7 has a circular cross section and a diameter of approximately 0.2 mm to 0.4 mm. As shown in the top view, the length b in the direction parallel to the wafer surface gradually decreases from the body 8 to the tip, while the length h in the direction perpendicular to the wafer surface gradually decreases as shown in the side view. 8 is larger than the proximal end, and the vertical length h gradually decreases at the tapered part 9, but at any point, the horizontal cross-sectional shape is such that the horizontal length b is greater than the vertical length h. In the example, h=(3-4)b.

[0009] An example of a manufacturing method for this is that a material having a circular cross-sectional shape for both the body part and the tapered part is pressed with a press die, and the horizontal length b is changed to the original circular cross-section. This can be done by plastically deforming the material to a diameter smaller than the diameter of the material. FIG. 4 shows an enlarged perspective view of the probe needles 5 of the present invention arranged in two layers along one side of a rectangular opening.

0010

Effects of the Invention According to the present invention, while obtaining the probe pressure necessary for measurement, the cross-sectional area can be reduced by the increase in the second moment of area. Since the length b can be made smaller,
We were able to significantly improve the limit on probe needle density.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a perspective view showing a probe needle of the present invention.

FIG. 3 is a plan view, a side view, and a cross-sectional view of various parts of the probe needle of the present invention.

FIG. 4 is a perspective view showing an example of the arrangement of probe needles of the present invention.

FIG. 5 is a plan view, a side view, and a cross-sectional view of various parts of a conventional probe needle.

[Explanation of symbols]

1...Printed wiring board 2...Opening 3...Integrated circuit wafer 4... probe stand 5... Probe needle 6... Probe needle tip 7... Probe needle base end 8...Probe needle body 9...Probe needle taper part

Claims (1)

[Claims] Claim 1: A probe stand for adhesively holding the body of a probe needle is fixed on a printed wiring board, the proximal end of the probe needle is connected to the printed wiring, and the tip of the probe needle is to be inspected. In a device that is bent into a hook shape to contact an electrode pad on an integrated circuit wafer, the cross-sectional shape of at least a portion from the tip to the body of the probe needle is non-circular, and the cross-sectional shape of the probe needle is noncircular. A high-density probe card characterized in that it has a substantially rectangular shape whose length in the direction parallel to the surface of the circuit wafer is smaller than the length in the direction perpendicular to the surface of the integrated circuit wafer.