JP3099943B2 - Probe card and reinforcing material used for the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a probe card used for measuring various electrical characteristics of an LSI chip and a reinforcing material used for the probe card.

As shown in FIG. 4, a conventional probe card has an LSI chip 610 formed on a wafer 600 fixed on a movable table 650 by vacuum suction or the like.
The substrate 300 on which the predetermined pattern wiring 320 is formed and the substrate 30
The ring 200 has a ring 200 made of ceramics or the like as a support mechanism for supporting the probe 100 attached thereto, and a plurality of probes 100 attached to the ring 200 with an epoxy adhesive 220.

A probe card is a recent LSI chip 6
With the increase in the density of the wafer 10 and the diameter of the wafer 600, the number of LSI chips 610 that can be measured simultaneously is increasing.
For example, 16 or 32 LSI chips 610 are measured simultaneously. For this reason, the number of probes 100 used in the probe card and the number of wiring patterns 320 are also increasing, so that the wiring patterns 320 are miniaturized and the substrate 300 is becoming multilayered and larger.

[0004]

However, the substrate 3
When the layer 00 is multi-layered and large, the weight naturally increases.
In addition, as the number of probes 100 increases, the size of the ring 200 (support mechanism) increases, and the weight naturally increases. For this reason,
If the diameter of the substrate 300 exceeds 30 cm, the substrate 300 is distorted by weight. In particular, the substrate 30
The central part of 0 is greatly distorted. If the substrate 300 is distorted, the contact pressure of the contact portion 110 of the probe 100 with respect to the electrode pad 611 of the LSI chip 610 cannot be kept constant and may cause a positional shift. Characteristic measurement becomes impossible.

For this reason, there has been a probe card reinforced with a reinforcing material such as a stainless steel plate having a thickness of several millimeters so that the substrate is not distorted. However, when the reinforcing material such as a stainless steel plate is used in this way, the problem of distortion due to the weight of the probe card is solved to some extent, but the weight of the probe card increases. In a burn-in test for measuring various electrical characteristics while the wafer is heated to a predetermined temperature, the probe card itself has heat due to radiant heat. Further, since the substrate and the stainless steel reinforcing material have different thermal expansion coefficients, a problem arises in that the probe card itself is distorted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a probe card which is lightweight, does not cause distortion of the substrate, and hence the entire probe card, and is suitable for a burn-in test, and a reinforcing material used therefor. I have.

[0007]

A probe card according to the present invention comprises: a substrate on which a predetermined pattern wiring is formed; a plurality of probes connected to the pattern wiring; a reinforcing member attached to the substrate; A supporting mechanism attached to the reinforcing member to support the probe, wherein the reinforcing member is divided into a plurality of small rooms.

The reinforcing member in the probe card according to the second aspect is a honeycomb structure.

Further, it is desirable that the small room of the reinforcing material is filled with carbon fiber which is a material having excellent heat conductivity.

Preferably, the reinforcing member is made of Invar, which is a material having a small coefficient of thermal expansion.

Further, as a reinforcing material, there is also a plate-like reinforcing material made of invar which is a material having a small thermal expansion coefficient.

On the other hand, the reinforcing material used in the probe card according to the present invention is a reinforcing material attached to a substrate constituting the probe card, is divided into a plurality of small rooms, and has excellent heat conduction inside. Carbon fiber, which is a material that has been filled.

[0013] The reinforcing member is formed of a honeycomb structure.

[0014]

[0015]

FIG. 1 is a schematic sectional view of a probe card according to an embodiment of the present invention, FIG. 2 is a schematic bottom view of the probe card according to an embodiment of the present invention, and FIG. FIG. 7 is a schematic partially broken perspective view of a reinforcing member used for the probe card according to the embodiment.

The probe card according to the embodiment of the present invention includes a substrate 300 on which a predetermined pattern wiring 320 is formed.
A plurality of probes 100 connected to the pattern wiring 320, a reinforcing member 400 attached to the substrate 300, and a ring 200 as a supporting mechanism attached to the reinforcing member 400 and supporting the probe 100. doing.

First, the substrate 300 is a multilayer substrate made of glass epoxy resin or the like, and the respective layers are electrically connected by through holes 330. Further, a pattern wiring 320 is formed in each layer.

At the center of the substrate 300, an opening 310 is provided.
Has been established. The opening 310 is for visually recognizing the LSI chip 610 formed on the wafer 600 to be inspected, and is set in an oval or rectangular shape as required.

A connector 340 to which an end of the pattern wiring 320 is connected is arranged on the upper peripheral edge of the substrate. Further, on the periphery of the substrate 300,
A through hole 350 is provided. This through hole 350
The substrate 300 is mounted on the mounting substrate 800 by mounting screws 810.

The probe 100 is formed by, for example, sharpening the tip of a tungsten wire as a contact portion 110 and bending the contact portion 110 at a length of 0.2 to 0.5 mm to about 100 °. The arrangement of the probes 100, particularly the arrangement of the contact portions 110, must correspond to the arrangement of the electrode pads 611 formed on the LSI chip 610.

The reinforcing member 400 is made of a material having a very low coefficient of thermal expansion, that is, an iron-nickel alloy called invar. A typical composition of this invar is Mn of 0.4%, C of 0.2%, Ni of 36% and the remainder of Fe. The reinforcing member 400 is a so-called honeycomb structure in which a large number of thin plates made of Invar having a thickness of 1 mm and a width of 10 mm are combined in a hexagonal column shape and arranged.

The hexagonal small chamber 410 of the reinforcing member 400 is filled with carbon fiber 420, which is a material having excellent heat conductivity, as shown in FIG. For example, a very light carbon fiber 420 having a bulk density of about 0.005 is used. For this reason, the total weight is not largely influenced by the filled carbon fiber 420.

As shown in FIG. 3, an invar thin plate 4 having a thickness of 1 mm is provided on the upper and lower surfaces of the reinforcing member 400.
30 is attached by an epoxy adhesive.
Thereby, the carbon fiber 4 filled in the individual room 410
20 is prevented from falling off.

The reinforcing member 400 has a predetermined opening 4
10 are provided. The opening 410 is formed in the substrate 30
The shape is set to correspond to the shape of the opening 310 and the size thereof is set smaller than the opening 310 by a predetermined dimension.

The reinforcing member 400 is mounted on the upper surface of the substrate 300 by mounting screws 450. On this occasion,
Opening 310 of substrate 300 and opening 410 of reinforcing material 400
And the edge of the opening 410 of the reinforcing member 400 can be seen through the opening 310 of the substrate 300.

In the above description, the reinforcing member 400
Is a so-called honeycomb structure divided into a plurality of hexagonal small rooms 410, but the present invention is not limited to this. The shape of the small rooms 410 may be other shapes such as a triangle or a quadrangle, and it is not necessary that all the small rooms 410 have the same shape.

A ring 200 is attached to the reinforcing member 400 through the opening 310 from the back side of the substrate 300. That is, the ring 200 is
Is connected directly to the substrate 300 via the reinforcing member 400 without being directly attached to the substrate. The ring 200 is set in accordance with the size and shape of the opening 310.

The ring 200 is provided with the probe 10
It constitutes a support mechanism for supporting the O. 0, and is made of insulating ceramics or the like. The ring 200 has a tapered surface 210 which is inclined downward from the outside toward the inside. This tapered surface 210 is the portion where the probe 100 is attached.

The probe 100 is attached to the ring 200 by using an epoxy resin adhesive 220 having an insulating property.
Done by

Next, the operation of measuring the various electrical characteristics of the LSI chip 610 using the probe card configured as described above will be described. First, the wafer 600 is fixed on the movable table 650 by vacuum suction or the like. Thereafter, the movable table 650 is raised, and the contact portion 110 of each probe 100 is brought into contact with the electrode pad 611 of the LSI chip 610 at a predetermined contact pressure.

In this state, signals are exchanged between a prober (not shown) and the LSI chip 610 to measure various electrical characteristics. This operation is repeated, and the measurement of the electrical characteristics of all the LSI chips 610 formed on one wafer 600 is performed.

If the probe card uses thousands of probes 100, the weight of the probe 100 is
0 directly to the reinforcement 400. Since the reinforcing member 400 is connected to the substrate 300 over a wide area, the weight of the probe 100 per unit area of the substrate 300 is much smaller than that of the conventional one. That is, in the case of a conventional probe card, as shown in FIG. 1, the ring 200 was directly attached to the substrate 300, and the area where the ring 200 was in contact with the substrate 300 was small. The weight of the probe 100 added per area is much larger than that of the probe card according to the present invention. Therefore, even if the probe card according to the present invention has the same weight of the probe 100, the distortion of the substrate 300, that is, the distortion of the probe card is significantly reduced.

Further, even if the substrate is used in an atmosphere of a hundred and several tens of degrees in a burn-in test which is a high temperature test, the substrate 300
The difference in the degree of expansion due to the difference in the thermal expansion coefficient between the substrate 300 and the reinforcing member 400 is absorbed by the slip between the substrate 300 and the reinforcing member 400. Therefore, in the burn-in test, there is no problem that the substrate 300 is distorted and the probe card itself is distorted.

In the above description, the reinforcing member 400 is made of an iron-nickel alloy called Invar, but may be made of aluminum.

Further, the reinforcing member 400 may be a normal plate-shaped member instead of the honeycomb structure. In this case, it is desirable to use invar, which is a material having a very low coefficient of thermal expansion.

[0036]

According to the probe card of the present invention, a substrate on which a predetermined pattern wiring is formed, a plurality of probes connected to the pattern wiring, a reinforcing member attached to the substrate, A supporting mechanism attached to support the probe, wherein the reinforcing member is composed of a plurality of small rooms.

Then, even if the probe card is large and has thousands of probes, the weight per unit area of the probes with respect to the substrate can be significantly reduced as compared with the conventional one. For this reason, even with a large probe card, the distortion due to the weight of the probe can be greatly reduced as compared with the conventional one, and the contact pressure between the probe and the electrode pad is maintained at a predetermined value. Therefore, it is possible to more accurately measure various electrical characteristics of the LSI chip.

Further, in the probe card according to the second aspect, since the reinforcing member is formed of a honeycomb structure,
The number of small rooms can be increased, and the entire shape of the reinforcing member can be easily formed into an appropriate shape.

Further, in the probe card according to the third aspect, the small room of the reinforcing material is filled with carbon fiber as a material having excellent heat conductivity. For this reason, since the radiation heat from the wafer can be efficiently radiated, the distortion due to the thermal expansion of the probe card can be minimized.

Further, in the probe card according to the fourth aspect, as the reinforcing member, Invar which is a material having a small coefficient of thermal expansion is used. According to this, the thermal expansion of the reinforcing member due to the radiant heat applied to the probe card in the burn-in test is reduced, so that the distortion of the entire probe card is reduced and accurate measurement of various electrical characteristics of the LSI chip becomes possible. .

Further, in the probe card according to the fifth aspect, a substrate on which a predetermined pattern wiring is formed, a plurality of probes connected to the pattern wiring, a reinforcing member attached to the substrate, and the reinforcing member And a support mechanism for supporting the probe, which is attached to the plate, and the reinforcing member is a plate made of Invar, which is a material having a small thermal expansion integer. For this reason, the distortion of the entire probe card due to the thermal expansion of the reinforcing material is reduced, and the structure is simpler than the reinforcing material of the honeycomb structure, so that the cost can be reduced. Further, since the reinforcing material is plate-shaped, it can be easily attached to the substrate, and the thickness of the entire probe card can be reduced.

On the other hand, the reinforcing material used in the probe card according to the present invention is a reinforcing material attached to a substrate constituting the probe card, and is divided into a plurality of small rooms.
The small chamber is filled with carbon fibers.
Therefore, in a probe card using the same, even if the probe card is enlarged, distortion due to the weight of the probe can be greatly reduced as compared with the conventional one. For this reason, the contact pressure between the probe and the electrode pad can be maintained at a predetermined value, so that more accurate measurement of various electrical characteristics of the LSI chip becomes possible. In addition, the carbon fiber filled in the small room, which is a material excellent in heat conduction, can efficiently radiate radiant heat from the wafer.

Further, since the reinforcing material used in the probe card according to the seventh aspect is a honeycomb structure, the number of small rooms can be increased, and the entire shape of the reinforcing material can be appropriately formed. It will be easier.

Further, since the reinforcing material used in the probe card according to the eighth aspect is composed of Invar which is a material having a small coefficient of thermal expansion, the reinforcing material due to radiant heat applied to the probe card in the burn-in test is used. Since thermal expansion is reduced, distortion of the probe card as a whole is reduced, and accurate measurement of various electrical characteristics of the LSI chip becomes possible.

[0045]

[0046]

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a probe card according to an embodiment of the present invention.

FIG. 2 is a schematic bottom view of the probe card according to the embodiment of the present invention.

FIG. 3 is a schematic partially cutaway perspective view of a reinforcing member used in the probe card according to the embodiment of the present invention.

FIG. 4 is a schematic sectional view of a conventional probe card.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 probe 200 ring (supporting mechanism) 300 substrate 310 pattern wiring 400 reinforcing material

Continuing from the front page (72) Inventor Genichi Wakata 2-5-113, Nishi-Nagasu-cho, Amagasaki-shi, Hyogo Japan Electronic Materials Co., Ltd. (72) Inventor Hiroshi Iwata 2-5-1-13, Nishi-Nagasu-cho, Amagasaki-shi, Hyogo No. Japan Electronics Materials Co., Ltd. (56) Reference JP-A-4-119647 (JP, A) JP-A-5-41416 (JP, A) JP-A-3-45337 (JP, A) JP-A-7- 12850 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01R 1/073 G01R 31/28 G01L 21/66

Claims (8)

(57) [Claims] 1. A substrate on which a predetermined pattern wiring is formed, a plurality of probes connected to the pattern wiring, a reinforcing member mounted on the substrate, and a support mounted on the reinforcing member to support the probe. A probe card comprising a mechanism, wherein the reinforcing material is divided into a plurality of small rooms. 2. The probe card according to claim 1, wherein the reinforcing member is a honeycomb structure. 3. The probe card according to claim 1, wherein a carbon fiber is filled in the small chamber of the reinforcing material. 4. The probe card according to claim 1, wherein the reinforcing member is made of invar. 5. A substrate on which a predetermined pattern wiring is formed, a plurality of probes connected to the pattern wiring, a reinforcement attached to the substrate, and a support attached to the reinforcement to support the probe. A probe card comprising a mechanism, wherein the reinforcing member is a plate-like member made of invar. 6. A reinforcing material attached to a substrate constituting a probe card, wherein the reinforcing material is divided into a plurality of small rooms, and the small rooms are filled with carbon fibers. Reinforcement. 7. The reinforcing member used for a probe card according to claim 6, wherein the reinforcing member is formed of a honeycomb structure. 8. The reinforcing material used in the probe card according to claim 6, wherein the reinforcing material is made of invar.