JP3313031B2 - Probe card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe card, and more particularly, to a probe card characterized by a support structure for a needle holder.

[0002]

2. Description of the Related Art FIG. 2A is a front sectional view of a conventional probe card. This probe card has a large number of probe needles 10, and these probe needles 10 are fixed to a needle holder 12 with resin. This needle holder 12
It is directly fixed to the substrate 14 using an adhesive. A wiring pattern is formed on the substrate 14, and the probe needle 10 and an external inspection device 16 are formed through the wiring pattern.
And can be electrically connected. The subject 18 rests on the chuck top 20. The subject 18 is not particularly limited, but is an IC package, a semiconductor chip, a wafer, or the like. Lower the probe card or raise the chuck top 20 to move the probe needle 1
A predetermined test is performed by bringing the tip of the zero into contact with the electrode of the subject.

[0003]

When a subject is inspected at a high temperature using the above-described conventional probe card, the following problems occur. The subject 18 is heated to, for example, 70 to 90 ° C. by the chuck top 20.
When the probe card approaches 8, the temperature below the substrate 14 increases due to radiant heat from the subject 18 and the chuck top 20 and due to conductive heat from the probe needles 10. As a result, a temperature difference occurs between the upper surface and the lower surface of the substrate 14, and the substrate 14 is slightly thermally deformed so as to be convex downward as shown in FIG. Since the vicinity of the outer periphery of the substrate 14 is supported by some support means, the above-described deformation causes the vicinity of the center of the substrate 14 to be displaced downward. As a result, the support portion of the probe needle 10 (needle press 1
2) is displaced downward

On the contrary, when an object is inspected at a very low temperature, the substrate is thermally deformed so as to be convex upward, and the supporting portion of the probe needle 10 is displaced upward.

[0005] When the height position of the support portion of the probe needle 10 fluctuates in this manner, the contact pressure between the probe needle and the electrode of the subject deviates from a desired set value, causing inconvenience in the inspection.

FIG. 3 is a graph showing a change in the height position of the support portion of the probe needle due to the influence of heat. The horizontal axis indicates the elapsed time, and the vertical axis indicates the height position of the support portion of the probe needle. Curve 22 shows the relationship between the elapsed time from the point of contact of the chuck top heated to 100 ° C. with the tip of the probe needle and the displacement of the height position of the probe needle support. As the time elapses, the height position of the support portion of the probe needle is lowered, and is displaced downward by about 45 μm during the elapse of 15 minutes. On the other hand, a curve 24 shows the relationship between the elapsed time since the chuck top at 100 ° C. is separated from the tip of the probe needle and the displacement of the probe needle support. In this case, on the contrary, the support portion of the probe needle rises with time. Such a change in the height position of the support portion of the probe needle reflects the thermal effect of the entire probe card, but it is considered that a considerable portion is caused by thermal deformation of the substrate.

In obtaining the graph of FIG. 3,
The fluctuation of the height position of the support portion of the probe needle is actually measured as the fluctuation amount of the height position of the tip of the probe needle when the probe needle is in a free state. For example, to obtain the curve 22, to measure the height position of the probe needle at the start, the height of the chuck top when the chuck top is raised and the chuck top contacts the tip of the probe needle is measured. The position has been detected. To measure the height position of the support portion of the probe needle after 5 minutes, lower the chuck top once after 5 minutes, separate the chuck top from the probe needle, and raise the chuck top again. Thus, the height position of the chuck top at the time when the chuck top comes into contact with the tip of the probe needle is detected.
By performing such a measurement, it is possible to determine how the height position of the support portion of the probe needle changes.

As described above, when the subject and the chuck top are heated, the height position of the support portion of the probe needle changes with time mainly due to thermal deformation of the substrate. Therefore, when the subject is heated to a high temperature, it is impossible to maintain the contact pressure between the probe needle and the electrode of the subject at a desired value. After the temporal fluctuation of the height position of the support part of the probe needle has subsided, it is conceivable to perform inspection by setting the contact pressure of the probe needle correctly again, but until the fluctuation of the probe needle height position subsides to some extent Is very time consuming and not realistic. The conventional probe card required at least about 5 minutes.

By the way, in order to prevent thermal deformation of the substrate, it is conceivable to form the substrate with a material having a small coefficient of linear expansion.
Regarding this point, JP-A-58-165056, JP-A-63-244750, and JP-A-2-156.
In the probe card disclosed in Japanese Patent No. 161 gazette,
Since the substrate is formed of ceramics, it is considered that thermal deformation of the substrate hardly occurs.

However, when the substrate is formed of ceramics, another problem as described below occurs. Recently, the number of pins of an IC has been increased, and the number of electrodes to be contacted for inspection has been extremely increased. Therefore, one probe card has a very large number of probe needles. Along with this, the number of wiring patterns formed on the substrate of the probe card has increased, and a multilayer wiring pattern has been required. As an example of a substrate having a multilayer wiring pattern formed thereon, a probe card substrate is formed by laminating 14 layers of a thin glass epoxy plate or a polyimide plate having a wiring pattern formed on the surface thereof. In the case of a substrate having such a multilayer wiring pattern, it is extremely difficult to form the substrate from ceramics, and even if it can be formed, it becomes very expensive.

It is an object of the present invention to provide a probe card in which the height position of the support portion of the probe needle does not fluctuate much even when the substrate is thermally deformed. Another object of the present invention is to provide a probe card in which a height position of a support portion of a probe needle does not vary so much when a high-temperature subject is inspected using a substrate having a multilayer wiring pattern. .

[0012]

According to the present invention, there are provided a plurality of probe needles, a needle holder for fixing the probe needles so that the tip positions of the probe needles correspond to the electrode arrangement of the subject, a probe needle and an external And a substrate on which a wiring pattern for electrically connecting to the inspection device is formed. The probe card has the following configurations (a) to (nu). (A) a substrate through-hole is formed in the center of the substrate,
The wiring pattern is provided on the outer periphery of the substrate by the inspection apparatus.
Are formed to connect to the electrodes . (B) A support plate is fixed on the upper surface of the substrate so as to cover the substrate through-hole. (C) The needle holder is fixed to the lower surface of the support plate. (D) The needle holder is inside the substrate through hole and does not contact the substrate. (E) The lower end of the needle holder protrudes downward from the substrate through hole. (F) A support plate through hole is formed in the support plate. (G) The support plate through-hole is located above the tip of the probe needle. (H) A needle holding through hole is formed in the needle holding. (I) The needle holding through-hole is located above the tip of the probe needle. (G) The fixed position of the substrate and the support plate is located on the outer peripheral side of the substrate with respect to the fixed position of the support plate and the needle holder.

When the substrate is thermally deformed, the thermal deformation of the substrate in a portion inside the fixed position between the substrate and the support plate does not affect the height position of the needle holder. The fluctuation in the height of the support portion of the probe needle is reduced by that much. Further, in the present invention, since the support plate is disposed on the upper surface of the substrate and the probe needle is disposed below the substrate, the support plate does not receive radiant heat from the subject or the chuck top, and the support plate itself is not received. Almost no thermal deformation occurs.

By the way, in the present invention, the up-down relationship with respect to the substrate is referred to as “down” on the side where the probe needle is present, and “up” on the side opposite thereto, regardless of the direction of gravity. Therefore, in an actual probe card embodying the present invention, the support plate may be fixed to the lower surface of the substrate and the probe needle may be arranged above the substrate.

[0015] In the present invention, the farther the fixed position between the substrate and the support plate is from the fixed position between the support plate and the needle holder toward the outer periphery, the higher the height position of the support plate based on the thermal deformation of the substrate. Is small. Considering the actual dimensions of the probe card, the distance between the two fixed positions is preferably 20 mm or more. Preferably, it is 30 to 50 mm. The upper limit value (50 mm) of the fixed position interval is limited by the external dimensions of the probe card used.

The present invention is particularly advantageous when the substrate has a multilayer wiring pattern. Since it is difficult to arbitrarily select a material having a small linear expansion coefficient (for example, ceramics) as the material of the substrate having the multilayer wiring pattern, the height variation of the support portion of the probe needle can be changed by configuring as in the present invention. It is effective to reduce the influence of thermal deformation of the substrate on the temperature.

[0017]

1A and 1B show a probe card according to an embodiment of the present invention. FIG. 1A is a plan view, and FIG.
(C) is a cross-sectional view taken along line CC of (A). The probe card is a substrate 36 made of glass epoxy.
And a support plate 42 made of aluminum nitride ceramics.
, A needle holder 32 made of free-cutting ceramics, and a probe needle 30. As shown in (C), a large number (for example, 4
The probe needle 30 of the (00) probe has a resin 34
Is fixed to the needle holder 32. The tip of each probe needle 30 is set at a position corresponding to the electrode arrangement of the subject. The root portion of the probe needle 30 is fixed to a wiring pattern formed on a glass epoxy substrate 36 by soldering. The needle holder 32 protrudes downward from a rectangular through hole 38 (substrate through hole) at the center of the substrate 36. The needle holder 32 is fixed to the support plate 42 by four sets of fastening devices 40 including screws and nuts, as shown in FIG. The upper surface of the needle holder 32 is the support plate 4
0 is fixed in contact with the lower surface. Fastening device 4
The nut No. 0 is tightened via a spring washer.

The support plate 42 is fixed to the substrate 36 by another four sets of fastening devices 44 composed of screws and nuts. The lower surface of the support plate 42 is fixed in contact with the upper surface of the substrate 36. The nut of the fastening device 44 is also fastened via a spring washer.

In the fastening devices 42 and 44, the nut is tightened via the spring washer so that even if the screw itself thermally expands, this can be absorbed by the spring washer.

The position of the fastening device 44 for fixing the substrate 36 and the support plate 42 is on the outer peripheral side of the substrate 36 with respect to the position of the fastening device 40 for fixing the support plate 42 and the needle holder 32. The distance L between the devices 40 and 44 is 40 mm.

The substrate 36 and the support plate 42 have a circular outer shape, and the needle holder 32 has a rectangular outer shape. The fastening device 40 for fixing the needle holder 32 is disposed near four rectangular corners of the needle holder 32. At the center between the needle holder 32 and the support plate 42, rectangular through holes 46 (needle holder through holes) and 48 (support plate through holes) having substantially the same size are formed as shown in FIG. The contact state between the probe needle 30 and the electrode of the subject can be observed from above using a microscope or the like.

The substrate 36 is formed by laminating 14 thin plates made of glass epoxy, and a wiring pattern is formed on the surface of each plate. That is, 1
Four-layer wiring patterns are formed. With such a multilayer wiring pattern, it is possible to form a large number of wirings on the substrate 36 corresponding to a subject having a large number of electrodes. One end of each wiring of the wiring pattern
All of them are exposed in the vicinity of the through hole 38 on the lower surface side of the substrate 36, and the other end is formed on the substrate 36 as shown in FIG.
Is exposed as an electrode 50 in the vicinity of the outer peripheral edge on the upper surface side. A large number of electrodes 50 are arranged concentrically, and the number thereof corresponds to the number of probe needles 30. (A)
In FIG. 2, only a part of the large number of electrodes 50 is shown, and in practice, the electrodes 50 are arranged all around the substrate 36.

As shown in FIG. 2B, the lower surface of the outer peripheral portion of the substrate 36 is supported by the holder 52. The pins 56 of the inspection device (tester) 54 come into contact with the electrodes 50 exposed on the upper surface of the outer peripheral portion of the substrate 36.

Although it is possible in principle to form the needle holder 32 and the support plate 42 integrally, the needle holder 32 and the support plate 42 are separate members for the following manufacturing reasons. It is necessary to configure. The most important thing in manufacturing the probe card is to make the position of the tip of the probe needle 30 correspond exactly to the electrode arrangement of the subject. In the operation of fixing the probe needle 30 to the needle holder 32, the tip of the probe needle 30 is accurately positioned using a special jig. Then, the intermediate portion of the probe needle 30 is inserted into the groove formed in the needle holder 32,
This is covered with a resin 34, and then the assembly composed of the needle holder 32 and the probe needle 30 is heated in a furnace so that the resin 3
4 is solidified. The needle holder 32 to which the probe needle 30 is fixed is fixed to a support plate 42 using a fastening device 40. After that, the root portion of the probe needle 30 is soldered to the wiring pattern of the substrate 36.

If the needle holder 32 and the support plate 42 are formed integrally, the support plate 42 is considerably larger than the needle holder 32.
Setting work of 0 becomes very inconvenient. Further, it is almost impossible to fix the support plate 42 on the upper side of the substrate 36 and solder the root portion of the probe needle 30 to the wiring pattern exposed on the lower side of the substrate 36. Become.

Next, a method of using the probe card will be described. In FIG. 1, a subject is placed on a chuck top (not shown), and this is arranged below a probe card. Then, the chuck top is raised to bring the tip of the probe needle 30 into contact with the electrode of the subject. The chuck top is further raised by a predetermined distance from the point of contact, and overdrive is applied to obtain a predetermined needle pressure. In this state, the subject is tested using the testing device 54.

In the case where the subject is inspected at a high temperature, the subject is heated from the chuck top side to bring the subject to a predetermined temperature before bringing the subject into contact with the probe needle. afterwards,
The electrode of the subject is brought into contact with the probe needle 30. At this time, radiation heat from the subject and the chuck top and conduction heat from the probe needle cause the substrate 36
The temperature on the lower surface side of is increased. Thereby, the substrate 36 is slightly deformed so as to be convex downward. At this time, the amount of displacement of the needle holder 32 at the height position depends only on the amount of change in the height position of the substrate 36 at the position of the fastening device 44 and the amount of deformation of the support plate 42. That is, the deformation of the substrate 36 on the radially inner side of the fastening device 44 does not affect the height position of the needle holder 32. Since the substrate 36 is supported by the holder 52 at the outer peripheral portion, a change in the height position of the substrate 36 is not so large at the position of the fastening device 44 near the outer peripheral portion. Further, since the support plate 42 is made of an aluminum nitride-based ceramic, thermal deformation hardly occurs. Further, since the support plate 42 is located behind (upper side of) the substrate 36, it does not receive radiant heat from the subject or the chuck top, and there is almost no difference in temperature between the upper and lower sides of the support plate 42. For this reason, the support plate 42 is unlikely to be thermally deformed.

For the above reason, even if the substrate 36 is thermally deformed, the fluctuation of the height position of the needle holder 32 is much smaller than in the prior art. When the same experiment as that shown in FIG. 3 was performed on the probe card of this embodiment, the amount of fluctuation of the support portion of the probe needle was reduced by about 30% compared with the related art.

In the above-described embodiment, the probe card is arranged above and the subject is arranged below. However, on the contrary, the subject may be arranged above and the probe card may be arranged below.
In the latter case, the probe needle is arranged above the substrate, and the support plate is arranged below the substrate.

[0030]

According to the probe card of the present invention, the support plate is fixed to the upper surface of the substrate, and the needle holder is fixed to the lower surface of the support plate. Thermal deformation of the substrate in a portion inside the fixed position does not affect the height position of the needle holder. Further, the support plate does not receive radiant heat from the subject or the chuck top, and the support plate itself hardly undergoes thermal deformation. Thereby, the fluctuation of the height of the support portion of the probe needle during the high temperature measurement is reduced.

[Brief description of the drawings]

FIG. 1A is a plan view of one embodiment of the present invention, and FIG.
3A is a cross-sectional view taken along the line BB in FIG. 3A, and FIG.

FIG. 2 is a front sectional view of a conventional probe card.

FIG. 3 is a graph showing a change in a height position of a support portion of a probe needle in a conventional probe card.

[Explanation of symbols]

 Reference Signs List 30 probe needle 32 needle holder 36 substrate 38 substrate through hole 40 fastening device 42 support plate 44 fastening device 46 needle holder through hole 48 support plate through hole 50 electrode 54 inspection device

Claims (3)

(57) [Claims] The present invention relates to a plurality of probe needles, a needle holder for fixing the probe needles so that the tip positions of the probe needles correspond to the electrode arrangement of the subject, and electrically connecting the probe needles and an external inspection device. A probe card comprising a substrate on which a wiring pattern for connection is formed, the probe card having the following configuration. (A) a substrate through-hole is formed in a central portion of the substrate,
The wiring pattern is connected to the inspection device on the outer periphery of the substrate.
An electrode for connection is formed. (B) A support plate is fixed on the upper surface of the substrate so as to cover the substrate through-hole. (C) The needle holder is fixed to the lower surface of the support plate. (D) The needle holder is inside the substrate through hole and does not contact the substrate. (E) The lower end of the needle holder protrudes downward from the substrate through hole. (F) A support plate through hole is formed in the support plate. (G) The support plate through-hole is located above the tip of the probe needle. (H) A needle holding through hole is formed in the needle holding. (I) The needle holding through-hole is located above the tip of the probe needle. (G) The fixed position of the substrate and the support plate is located on the outer peripheral side of the substrate with respect to the fixed position of the support plate and the needle holder. 2. A fixing position between the substrate and the support plate,
The fixed position of the support plate and the needle holder is 20 mm
2. The probe card according to claim 1, wherein the probe cards are separated from each other. 3. The probe card according to claim 1, wherein the substrate has the multilayer wiring pattern.