JP2001281267A - Gas introduction unit for probe card and probe card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit the observation of the tip of a probe needle with a gas introduction unit mounted and further blowing of a purge gas near the tip of the probe needle simply by mounting the gas introduction unit on the existing probe card. SOLUTION: A gas introduction unit 12 is mounted on a substrate 10 of a probe card. The gas introduction unit 12 is provided with a rectangular ring- like frame 14 and a rectangular space is formed inside. A rectangular transparent glass plate 16 is placed on the frame 14. A purge gas 34 introduced from a gas introduction pipe 30 blows inward from gas blowoff ports 26 in a pair of opposed side walls 21 and 23 through a gas introduction path 24 and passes through slots 36 formed in the substrate 10 to be sent against the tip of the probe needle 38. Even when the gas introduction unit 12 is mounted on the substrate 10, the tip of the probe needle 38 can be observed from above through the glass plate 16 and the slots 36.

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 blowing an inert gas near the tip of a probe needle, and a gas introduction unit for blowing such an inert gas.

[0002]

2. Description of the Related Art A probe card in which an inert gas is blown near the tip of a probe needle is known. FIG.
0 (a) is a conventional technique described in FIG. 5 of Japanese Patent Application Laid-Open No. 11-218548. According to this conventional technique, in a probe card having a cantilever type probe needle 80, nitrogen gas is injected into the vicinity of the probe tip of the probe needle 80 by allowing the tip of the nitrogen jet nozzle 84 to enter the opening 82 of the substrate 81. It spouts out to prevent oxidation of the needle tip.

[0003] FIG. 10B is a diagram showing a conventional Japanese Patent Application Laid-Open No. 11-218.
This is the prior art described in FIG. In this prior art, in a vertical probe card, a nitrogen injection nozzle 90 is viewed through a nitrogen injection hole 88 provided in a ceramic upper substrate 86, and a nitrogen gas is injected into a hollow portion 91 therefrom. . A guide hole 96 for projecting the probe needle 94 to the lower surface of the probe card is formed in the ceramic lower substrate 92, and nitrogen gas is blown from the guide hole 96 to the needle tip.

[0004]

In the prior art shown in FIG. 10A, the purge gas is apt to diffuse before reaching the vicinity of the probe tip of the probe needle 80. Air may remain. Further, since the nitrogen ejection nozzle 84 is located above the opening 82, the nitrogen ejection nozzle 84 becomes an obstacle when observing the positional relationship between the tip of the probe needle 80 and the electrode pad of the wafer from above. Also, since it is sprayed directly with the nozzle 84,
It is difficult to spray nitrogen gas uniformly on the tips of many probe needles.

In the prior art shown in FIG. 10B, a structure for spraying nitrogen gas is incorporated into the probe card itself, and it is necessary to design a dedicated probe card for spraying nitrogen gas. Further, since the upper substrate 86 and the lower substrate 92 made of ceramic are present, the tip of the probe needle 94 cannot be observed from above. Further, since the needle tip guide hole of the lower substrate is also used as a flow path for the purge gas, the flow rate of the purge gas is insufficient if the inside diameter of the guide hole is small, and the needle tip position becomes unstable if the inside diameter of the guide hole is large. . Incidentally, Japanese Patent Application Laid-Open No. H11-218548
Japanese Patent Application Laid-Open Publication No. H11-209,086 discloses an embodiment in which a dedicated gas ejection hole for passing a purge gas is formed in a substrate without using a needle tip guide hole as a gas flow path. It is necessary to design a dedicated probe card board.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to attach a gas to an existing probe card so that an inert gas can be blown to the vicinity of the probe tip. To provide units. Another object of the present invention is to provide a gas introduction unit capable of observing the tip of a probe needle. Still another object of the present invention is to provide a probe card having the above-described gas introduction unit.

[0007]

The gas introduction unit of the present invention has the following constitutions (a) to (f).
(A) An annular frame forming a space inside. (B) a transparent cover for covering one open end of the annular frame;
(C) A gas introduction passage formed in a side wall constituting the frame. (D) a plurality of gas blowing holes formed in the side wall and communicating the gas introduction passage with the space. (E) a gas introduction pipe connected to the outer surface of the side wall and communicating with the gas introduction passage; (F) A fastening device for attaching the other open end of the frame to the substrate of the probe card.

In this gas introduction unit, one open end of the annular frame is covered with a transparent cover, so that even if the gas introduction unit is mounted on the substrate of the probe card,
The tip of the probe needle can be observed. Further, since the gas introduction pipe is connected to the outer surface of the side wall of the frame, the gas introduction pipe does not hinder the observation of the needle point. Since this gas introduction unit can be used by attaching it to an existing probe card, there is no need to design a dedicated probe card for gas introduction.

In the present invention, the frame may be an annular frame. In this case, the annular gas introduction passage may be formed inside the side wall, and the plurality of gas blowing holes may be arranged at equal intervals in the circumferential direction on the inner peripheral surface of the frame. Further, the frame may be a rectangular ring-shaped frame. In that case,
A straight gas introduction passage may be formed in each of the pair of opposed side walls of the frame. A through hole for passing a signal cable can be formed in a side wall constituting the frame. This through-hole is hermetically sealed with the signal cable passed through.

A probe card according to the present invention includes a probe needle, a substrate having a through hole for observing the tip of the probe needle, and a gas introduction unit as described above.

[0011]

FIG. 1 is a plan view showing a first embodiment of a probe card according to the present invention, and FIG. 2 is a sectional view taken along line 2-2 of FIG. This probe card tests the dielectric breakdown phenomenon of an oxide film over time by heating the wafer to a high temperature to accelerate the degradation phenomenon (time dependent die).
This is a probe card for lectric breakdown test (TDDB test). In FIG. 1, a gas introduction unit 12 is mounted on a substrate 10 of a probe card. The substrate 10 is rectangular, and the outline of the gas introduction unit 12 is also rectangular. The gas introduction unit 12 includes a rectangular annular frame 14. This frame 14
Is composed of four side walls 20, 21, 22, and 23, and a rectangular space is formed inside. These four side walls are formed integrally. This gas introduction unit 12
Is for supplying a purge gas (nitrogen gas) 34 to a space inside the frame 14 and for blowing a gas to the tip of the probe needle.

A rectangular transparent glass plate 16 (see FIG. 2) rests on the frame 14. This glass plate 16
Corresponds to a transparent cover that covers one open end of the frame 14. The glass plate 16 is fixed to the frame 14 by four linear glass plate holders 18. The glass plate retainer 18 is fixed to the upper surface of the frame 14 by screws 19. A pair of opposing side walls 2 of the frame 14
An inverted U-shaped handle 28 is provided on the upper surface of each of
(See also FIG. 2) is fixed.

A pair of opposing side walls 21 of the frame 14,
Inside each of the 23, a linear gas introduction passage 24 is formed. A large number of gas outlets 26 (see FIG. 2) communicate with the gas introduction passage 24, and these gas outlets 26 open on the inner surfaces of the side walls 21 and 23. Two gas introduction pipes 30 are provided on the outer surface of the side wall 20.
Are connected, and this gas introduction pipe 30 communicates with one end of each of the pair of gas introduction passages 24. A stopper 32 is connected to the other end of the gas introduction passage 24 and sealed. Purge gas 3 introduced from gas introduction pipe 30
4 blows inward from a pair of side walls 21 and 23 facing each other.

Near the center of the substrate 10, eight long holes 36 are formed so as to be parallel to each other. This long hole 36
Penetrates the substrate 10 in the vertical direction. A predetermined number of probe needles 38 are arranged on both sides of the elongated hole 36.

In FIG. 2, a space 15 is formed inside the frame 14. The annular frame 14 has two open ends, and the upper open end is covered with a transparent glass plate 16. The lower open end is the substrate 1 of the probe card.
Covered with 0. A chuck top 39 is provided below the probe card, and a wafer 40 is mounted thereon. The tip of the probe needle 38 comes into contact with the electrode pad of the wafer 40. A heater is incorporated in the chuck top 39 so that the wafer 40 can be heated to a high temperature.

FIG. 3 is an enlarged view of the circular area 3 of FIG.
Probe needles 38 are arranged on both sides of a long hole 36 penetrating the substrate 10. The probe needle 38 penetrates perpendicularly to the substrate 10. This substrate 10 is made of ceramic. The distal end portion 39 of the probe needle 38 is bent so as to face the long hole 36 and is further bent downward. The tip of the probe needle 38 comes into contact with the electrode pad 42 of the wafer 40. The vicinity of the tip of the probe needle 38 can be observed from above through the long hole 36.
The long hole 36 is provided between the tip of the probe needle 38 and the wafer 40.
This is for confirming the positional relationship with the electrode pad 42 from above. Since the upper surface of the gas introducing unit is a transparent glass plate 16, the vicinity of the tip of the probe needle 38 can be observed from above through the glass plate 16 and the elongated hole 36.

The purge gas 34 blown into the inside of the frame from the gas blowout holes 26 passes through the long holes 36 and blows out below the substrate 10. The purge gas 34 blown out from the long hole 36 hits the tip of the probe needle 38 and the wafer in the vicinity thereof, and further, the wafer 40
Flow along the surface of the. Therefore, the purge gas 34 serves to expel (purge) air existing on the surface of the wafer 40. In this embodiment, the flow rate of the nitrogen gas is about 40 liters per minute. By flowing the purge gas in this way, at the time of high temperature inspection,
Wiring (particularly copper wiring) exposed on the surface of the wafer 40 is prevented from being oxidized by oxygen in the air. At the same time, oxidation of the tip of the probe needle 38 that contacts the hot electrode pad is also prevented.

When the purge gas is blown onto the wafer, the temperature of the high-temperature wafer may be lowered to cause inconvenience. In such a case, the temperature of the purge gas may be increased to the same level as the temperature of the wafer. That is, the purge gas introduced into the gas introduction pipe may be a hot gas heated to a predetermined temperature.

This gas introduction unit is useful not only for preventing oxidation at high temperatures but also for preventing condensation at low temperatures. That is,
When inspecting a wafer at a temperature lower than room temperature, moisture in the air may condense on the surface of the wafer,
If a purge gas flows from the gas introduction unit, such dew condensation can be prevented.

FIG. 4 is a side view of the probe card shown in FIG. 1 (view from the right in FIG. 1). Two rectangular through holes 44 are formed in one side wall 20 of the gas introduction unit. The through hole 44 is for passing a signal cable connecting the probe needle to an external tester or the like. After passing through the signal cable, the through hole 44 is filled with a resin and hermetically sealed.

FIG. 5A is a sectional view taken along line 5a-5a of FIG. Purge gas 3 blown out from gas blowout hole 26
4 flows along the surface of the wafer 40 after passing through the long hole 36.

FIG. 6 is an enlarged view of the circular area 6 in FIG. Gas introduction holes 24 formed in the side wall 21 of the frame
Has a circular cross-section, and a number of gas blowing holes 26 are formed so as to be connected to the gas introducing holes 24.
The opening of the gas blowing hole 26 is tapered. The side wall 21 is fixed to the substrate 10 from below by screws 45. A counterbore 46 for accommodating the head of the screw 45 is formed on the lower surface of the substrate 10. The other three side walls of the frame are similarly fixed to the substrate 10. The screw 45 allows the gas introduction unit 12 to be attached to or detached from the probe card.
The screw 45 corresponds to a fastening device for attaching the gas introduction unit 12 to the probe card.

If a through hole for passing the screw 45 and the counterbore 46 are formed in the existing probe card, the gas introduction unit can be attached to the existing probe card. In that case, a long hole 36 for observing the probe needle
(See FIG. 3) also functions as a passage for allowing the purge gas to pass below the substrate. Therefore, if a through hole for observing the tip of the probe needle is formed in the existing probe card, it is not necessary to newly form a through hole for passing the purge gas in the substrate.

FIG. 5B is a sectional view taken along line 5b-5b of FIG. A glass plate 16 is fixed to the frame 14 by a glass plate holder 18.

FIG. 7 is an enlarged view of the circular area 7 in FIG. The glass plate retainer 18 is fixed to the upper surface of the side wall 21 of the frame by screws 19. Glass plate holder 1
A counterbore 48 for accommodating the head of the screw 19 is formed on the upper surface of 8.

FIG. 8 shows a second embodiment of the probe card according to the present invention.
FIG. 9A is a plan view showing the embodiment of FIG.
It is a sectional view taken on line a-9a. In FIG. 8, the probe card has a circular substrate 50. A circular gas introduction unit 52 is mounted on the substrate 50. The gas introduction unit 52 includes an annular frame 54,
A circular transparent glass plate 56 (see FIG. 9A) and an annular glass plate holder 58 are provided. Frame 5
An annular gas introduction passage 60 is formed in 4. The cross-sectional shape of the gas introduction passage 60 is rectangular as shown in FIG. A number of gas outlets 62 communicate with the gas introduction passage 60, and the gas outlets 62 open on the inner peripheral surface of the frame 54. These gas blowing holes 62 are arranged at equal intervals in the circumferential direction. A gas introduction pipe 64 is connected to the outer peripheral surface of the frame 54. The gas introduction pipe 64 communicates with the gas introduction passage 60. The purge gas (nitrogen gas) 34 introduced from the gas introduction pipe 64 is blown toward the center from a number of gas blow holes 62 on the inner peripheral surface of the frame 54. A through hole 66 is formed in the center of the substrate 50.
Through this through hole 66, the tip of the probe needle 68 can be observed from above.

In FIG. 9A, the probe needle 68 is fixed to the needle holder 70 on the lower surface side of the substrate 50. The probe tip of the probe needle 68 has a through hole 66 and a glass plate 56.
And can be observed from above through The tip of the probe 68 comes into contact with the electrode pad of the wafer 40 on the chuck top 39. The purge gas 34 introduced from the gas introduction pipe 64 blows out from the gas blowout hole 62 into the space inside the frame 54, passes through the through hole 66,
It goes below the substrate 50.

FIG. 9B is a sectional view taken along line 9b-9b of FIG. In the right half of FIG.
2 fixed to the substrate 50 from above. A notch 74 is formed in the glass plate retainer 58, and the head of the screw 72 contacts the upper surface of the frame 54 at the notch 74. In the left half of FIG. 9B, the glass plate retainer 58 is fixed to the upper surface of the frame 54 by screws 76.

In the second embodiment shown in FIG. 8, as in the first embodiment shown in FIG. 1, a through hole for passing a signal cable through an arbitrary portion of the annular side wall forming the frame 54 is provided. A hole is formed, and the through hole is hermetically sealed with resin while the signal cable is passed through.

The present invention is not limited to the above embodiment,
The following changes are possible: (1) As the purge gas, in addition to the above-mentioned nitrogen gas,
Other inert gas or reducing gas may be used. However, the nitrogen gas used in the above embodiment is optimal as a practical purge gas for preventing oxidation. Dry air can be used as a purge gas only to prevent condensation at low temperatures. (2) The above two embodiments are examples of probe cards for a wafer prober, but the present invention can be applied to other probe cards.

[0031]

According to the gas introduction unit of the present invention, a gas introduction pipe is connected to the outer surface of the side wall of the annular frame to introduce a purge gas into the space inside the frame, and one opening end of the frame is made transparent. It is covered with a cover. Thereby, the tip of the probe needle can be observed with the gas introduction unit attached. Further, by simply attaching this gas introduction unit to an existing probe card, the purge gas can be blown near the tip of the probe needle, and there is no need to design a dedicated probe card for gas introduction.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of a probe card of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is an enlarged view of a circular region 3 in FIG. 2;

FIG. 4 is a side view of the probe card shown in FIG.

FIG. 5 is a sectional view taken along line 5a-5a and a sectional view taken along line 5b-5b in FIG. 1;

FIG. 6 is an enlarged view of a circular area 6 in FIG.

FIG. 7 is an enlarged view of a circular area 7 in FIG. 5 (b).

FIG. 8 is a plan view showing a second embodiment of the probe card of the present invention.

9 is a sectional view taken along line 9a-9a and a sectional view taken along line 9b-9b in FIG. 8;

FIG. 10 is a front sectional view of a conventional probe card having a gas introduction unit.

[Explanation of symbols]

 Reference Signs List 10 substrate 12 gas introduction unit 14 frame 15 space 16 glass plate 18 glass plate holder 20, 21, 22, 23 side wall of frame 24 gas introduction passage 26 gas blowout hole 30 gas introduction pipe 34 purge gas 36 long hole 38 probe needle 39 chuck top 40 Wafer 44 Through-hole 45 Screw

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01L 21/66 G01R 31/28 K F Term (Reference) 2G003 AA10 AC01 AD01 AD04 AG04 AG12 AG13 2G011 AA02 AA17 AB06 AB10 AC13 AC14 AE03 AF06 2G032 AB02 AB03 AB13 AF01 AK04 AL03 AL04 4M106 AA01 BA01 DD10 DD22

Claims (5)

[Claims] 1. A gas introduction unit for a probe card having the following configuration. (A) An annular frame forming a space inside. (B) a transparent cover for covering one open end of the annular frame; (C) A gas introduction passage formed in a side wall constituting the frame. (D) a plurality of gas blowing holes formed in the side wall and communicating the gas introduction passage with the space. (E) a gas introduction pipe connected to the outer surface of the side wall and communicating with the gas introduction passage; (F) A fastening device for attaching the other open end of the frame to the substrate of the probe card. 2. The gas introduction unit according to claim 1, wherein the frame is an annular frame, and the annular gas introduction passage is formed inside the side wall, and an inner peripheral surface of the frame is provided. Wherein the plurality of gas blowing holes are arranged at equal intervals in a circumferential direction. 3. The gas introduction unit according to claim 1, wherein the frame is a rectangular annular frame, and a straight gas introduction passage is formed on each of a pair of opposed side walls of the frame. A gas introduction unit characterized in that: 4. The gas introducing unit according to claim 1, wherein a through hole for passing a signal cable is formed in a side wall constituting the frame, and the through hole is formed in the gas inlet unit. A gas introduction unit, which is hermetically sealed while passing through a signal cable. 5. A probe having a probe needle, a substrate having a through hole for observing a probe tip of the probe needle, and the gas introduction unit according to claim 1 attached to the substrate. A probe card, comprising: