JPH0782033B2 - 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 an IC on a wafer for electrical testing.
Etc. regarding a probe card for contacting.

[0002]

2. Description of the Related Art A conventional probe card for an IC is an IC
Since the contact pads of are fine and have a narrow pitch,
A tapered cantilever type probe pin is generally used for the contact portion with this. This probe pin is manufactured for each pin by electrolytic polishing or the like. Then, the probe card is completed through a process of arranging these tapered probe pins in a fan shape and mounting them on the substrate, and a process of bending the contact portions at the tips according to the arrangement of the pads of the IC to align the height and pitch. These processes are commonly called a needle stand, and their work requires craftsmanship.

[0003]

Such a conventional probe card adopts a tapered probe pin and is made depending on craftsmanship. However, as ICs become more highly integrated, the demands for increasing the number of pins and narrowing the pitch of probe cards are becoming stricter. On the other hand, the number of highly skilled workers who can meet such demands is extremely limited. For this reason, product performance tends to vary and reliability tends to decrease. Moreover, it is often difficult to readjust the work even during use, and it is difficult to handle. For example, a probe card with a pitch of 80 μm is handled carefully like a supreme work of art. Therefore, with this type of probe card, it is becoming difficult to keep up with the progress of IC.

In order to solve such a problem, a probe card having probe pins formed by etching has been proposed. However, dry etching is too poor in productivity, and wet etching causes taper etching to cause a cross-sectional shape of the pins. There is a defect that the required contact force cannot be secured because it is bad. Further, even if the cross-sectional shape is secured by using an anisotropic material, the material is limited and the conductivity cannot be secured. There is also a type of probe card that gives up the contact part as a pin and presses it by attaching a pad to the wiring pattern on the resin substrate, but with this, so-called overdrive cannot be secured, so contact pressure tends to fluctuate Resistance is unstable and unreliable.

For this reason, such probe cards of etching-based manufacturing methods, apart from experimental or limited use, are not practical. An object of the present invention is to solve such a problem of the conventional technique, and to realize a probe card having a configuration suitable for a probe test of an IC having a large number of pins and a narrow pitch.

[0006]

The probe card of the present invention for achieving this object has a plurality of wiring patterns directly or indirectly formed by a plating process, and has a plurality of wiring patterns. A flexible substrate having a first contact terminal which is exposed without being supported by the substrate and which is on the way or at the rear end side, and a second contact terminal which comes into contact with each of the first contact terminals are provided respectively. A card board having a plurality of pattern wirings, and a support plate that supports each of the tip portions as probe pins, and each first contact terminal on the flexible board is a second board of the card board.
It is connected to the contact terminal of.

[0007]

In the probe card of the present invention having such a structure, the support plate supports the tip end of the wiring pattern of the flexible substrate as a probe pin. As a result, the wiring pattern of the flexible substrate can contact the IC or IC chip on the wafer at its tip. Further, the wiring pattern of the flexible board and the wiring pattern of the card board are connected to each other by the contact terminals. With this, when the probe card is inserted into the prober, the IC and the tester can be connected via the wiring pattern of the flexible substrate and the wiring pattern of the card substrate.

[0008] Therefore, by matching the difference in pin pitch between the IC and the tester, electrical coupling is supported, and the IC probe test becomes possible. Thus, basically, only the mechanism for attaching and fixing the support plate and the flexible substrate to the card substrate is required, and the flexible substrate itself can also be used as the support plate, so that the support mechanism is simplified. Therefore, troublesome needle stand operation and many parts that reduce reliability are unnecessary,
As a result, the productivity and reliability of the probe card are improved.

Further, a flexible substrate having a wiring pattern having a tip portion as a probe pin is manufactured by plating. As a result, sufficient overdrive and contact pressure can be secured even when the number of pins is increased and the pitch is narrowed, and moreover, the probe pins can be efficiently manufactured integrally. Therefore, high productivity and reliability can be secured even for an IC having a large number of pins and a narrow pitch. Furthermore, maintenance such as pin replacement can be easily performed at once. Moreover, since mass production is relatively easy, even when a large number of probe cards having the same specifications are required when mass-producing ICs, it is possible to immediately deal with them.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a probe card. (A) is a perspective view of the whole, (b) is an enlarged view of a partial cross section, (c) is a cross-sectional view of a probe pin in particular. The cross-section hatching is omitted. here,
Reference numeral 14 is a probe pin as a tip portion of a wiring pattern formed by a plating process described later, 15 is a film as a flexible substrate that supports the wiring pattern, 2
0 is a printed circuit board as a card board, 21 is a conductor for ground, 22 is an O-ring for securing contact pressure, 23 is a clamper, 24 is a bolt, 25 is a stainless steel support plate, 26 and 27 are polyimide insulating sheets, 28 is a clamper and 29 is a bolt. Further, 30 is an image of the IC to be inspected.

The printed board 20 is a hardened board for supporting the contact force of all probe pins, and has a plurality of pattern wirings on its upper surface. Contact terminals are provided on both ends of these pattern wirings. One of the contact terminals is overlapped with the contact terminal on the rear end side of the probe pin 14, and the ground conductor 21 and the O-ring 2 are placed on the contact terminal.
2 and the clamper 23 and the bolt 24, the connection state with the probe pin 14 is maintained. The other contact terminal is connected to the tester side by a card edge connection or a spring pin contact when inserting the card into the prober. With this structure, the probe pin 14
The electrical connection between the IC 30 and the tester is secured via the. The card board may be an integrated article such as a printed board, or a combination article such as an FPC and its support plate.

The support plate 25 is composed of four trapezoidal parts, and the printed circuit board 20 has its inclined sides inside.
It is attached to the lower center of the. The insulating sheet 26, the probe pin 14, the film 15, the ground conductor 21, the insulating sheet 27, and the clamper 28 are fixed with bolts 29 on the inclined side. With this structure, the tip of the film 15 is supported as a probe pin. When this probe card is driven by the prober, the probe pins 14 come into contact with the contact pads of the IC 30 and are further overdriven, the tilted probe pins slightly scratch the contact pads of the IC 30. This ensures a secure contact,
You can trust the test results. When a bump is provided on the contact pad portion of the IC 30 or the tip of the probe pin, the probe pin does not need to be preliminarily tilted because overdriving is performed within the range of the bump height. . Alternatively, it may be inclined in the opposite direction.

A schematic view of the film 15 is shown in FIG. 2. This is for explanation purposes. In practice, the number of probe pins is generally several tens to several hundreds.
The pitch is not always constant. Film 15 is IC30
Has a substantially rectangular opening larger than the contact pad disposition portion (see 15b in FIG. 2). Then, the respective tip portions 14d and the like project along the respective sides of the opening 15b. With this opening, the tip portion functions as a probe pin, and the contact state between the tip of the tip portion 14d and the contact pad of the IC 30 can be monitored. In addition, a cut may be provided at a corner of the opening so that the flexible substrate 22 can be easily deformed without being damaged. Further, this may be configured as a combination of four trapezoidal shapes which are divided substantially along a diagonal line (see the alternate long and short dash line in FIG. 2).

Further, the position of the tip end portion is provided corresponding to the arrangement of the contact pads of the IC 30, and the contact terminals are arranged at a wide pitch corresponding to the arrangement of the contact terminals of the printed circuit board 20 on the rear end side of the wiring pattern connected to the contact pads. Is provided.
As a result, the fine and narrow pitch pads of the IC can be aligned with the spring pins and the like on the tester side, which are not so fine and have a wide pitch. When the contact pads of the IC 30 are not provided on all four sides but only on some sides, the probe pins may be provided at the corresponding portions. The same applies to the support plate 25. Of these individual parts that correspond to each of the four trapezoidal parts,
It can be configured by a combination of parts that are determined according to the arrangement of the contact pads of the IC 30.

Next, a method of manufacturing the flexible board (14 + 15) will be described. FIG. 3 shows a schematic sectional view in each step. Note that, hereinafter, the probe pin is simply called a pin, the wiring pattern is called a pattern, and the pin 14d
And the pattern 14e are collectively referred to as a pin 14. In addition, the pins 14 and the like and the film 15 as a whole are pin film bodies
4 + 15).

The pin manufacturing process is mainly performed by forming a first metal layer, forming a resist pattern which is the first half of the plating process, and forming a second metal layer as the second half of the plating process. It includes an electrolytic plating step of forming, a film adhering step, a peeling step which is the first half of the separating step, and a removing step which is the second half of the separating step. In addition, pin 14
The material is preferably Ni from the viewpoint of strength and toughness. further,
Pd and the like may be included. Further, when importance is attached to conductivity, it is preferable to coat gold to increase conductivity (see FIG. 1C). Alternatively, beryllium copper may be used instead of Ni. Hereinafter, each step will be described in this order.

In the step of forming the first metal layer, the copper layer 11 as the first metal layer is thinly electrolytically formed on the stainless steel plate 10 as the substrate layer. The use of copper as the first metal layer has excellent adherence to the Ni-made pins 14 and the like, and the adhesion to the stainless steel plate 10 is weaker than the adhesion of the film 15 to the Ni-made pins 14 and the like. , Because it is a good conductor. Since copper has better conductivity than stainless steel, electrolytic plating can be performed quickly and uniformly. The stainless steel plate 10 is mirror-finished so that its surface is flat and smooth.

In the step of forming the resist pattern, the copper layer 11 is used.
A photoresist 12 is coated on the above (see (a) of FIG. 3) and is exposed through a mask 13 (see (b) of FIG. 3). As a result, the pattern corresponding to the mask 13 is transferred to the resist 12. Further, this is developed to form a resist 12 having a pattern corresponding to the mask 13, and a resist mask is applied on the copper layer 11 (see FIG. 3C).

In the electrolytic plating process, the void 12a above the copper layer 11 that appears in the portion not covered with the resist mask is used.
Then, Ni is deposited and grown by electrolytic plating (see FIG. 3D). After the completion of Ni plating, the resist 12 is removed and the mask is removed (see FIG. 3D). The Ni layer thus formed is used for the pin 14.

In the film deposition step, a polyimide film 15 is coated on the Ni layer (14) to cover the pattern 14e and the like other than the portion provided for the pin 14d. Specifically, the adhesive plastic 15a is sandwiched and thermocompression bonding is performed from above the film 15 with a jig having a flat pressing surface (FIG. 3).
(F)). This makes the plastic side pin 1
Since it is partially deformed in accordance with No. 4, minute irregularities and uneven thickness existing on the upper surface of the Ni layer (14) are absorbed. As a result, the thickness of the pin film body (14 + 15) can be made uniform.

The film 15 also has an opening 15b (see FIG. 2). The opening 15b is bonded so as to correspond to the pin 14d. As a result, the pin 14d is supported by the film 15 in a cantilevered state, and the film 15 is used as a substrate that integrally supports the pin 14d and the like.

In the peeling step, the portion consisting of the copper layer 11, the Ni layer (14) and the film 15 is peeled from the stainless plate 10 between the stainless plate 10 and the copper layer 11 to separate it. As described above in the description of the step of forming the first metal layer, the adhesion force to the stainless steel plate 10 is weaker than the adhesion force of the film 15 to the Ni pins 14 and the like. Separates easily.

In the removing step, the copper layer 11 is removed from the Ni layer (14) by wet etching. Since the copper layer 11 is thin, an Ni layer (14) is formed by using an etching solution having a high selectivity.
The copper layer 11 is removed without damaging. As a result, the portion including the film 15 and the pin 14 is separated from the stainless layer 10 and the copper layer 11. The probe pin 14 manufactured in this manner has a substantially rectangular cross section (normally 50 μm × 50 μm). Therefore, when contacted by being bent in a cantilever shape, a contact pressure and an overdrive capacity larger than those of a triangular cross section or a circular cross section can be exhibited. In addition, the bending rigidity in the diagonal direction is large, and it rarely bends at an angle. Therefore, there is no inconvenience even if the pitch is narrowed (about 80μ
m).

Further, the side surface 14a which contacts the IC,
14b and 14c have a uniform height corresponding to the flat surface of the stainless steel plate 10. Therefore, there is no need to perform work for adjusting the height of the pin tip. Furthermore, the side surfaces 14a, 14b, and 14c to which tensile stress is applied when making contact with the IC have a smooth surface state corresponding to the smooth surface of the stainless plate 10. Therefore, the fatigue strength affected by the smoothness of the surface is increased, and the number of times of repeated use is improved.

In the flexible board (14 + 15) having such a pin, the film 15 functions as a support plate for supporting the tip portion 14d of the pin. Therefore, since these can be clamped as a unit, no craftsmanship is required when manufacturing the probe card. The probe card thus configured is inserted into the prober and electrically connected to the tester, and is used for a probe test or the like on the IC on the wafer.

[0026]

As can be understood from the above description, the probe card of the present invention has a plurality of wiring patterns formed by the plating process, and the respective tip portions of these wiring patterns are supported on the substrate. A flexible substrate having a first contact terminal on the rear end side which is exposed without being exposed, and a plurality of pattern wirings each provided with a second contact terminal that contacts each first contact terminal. A card board and a support plate that supports the tip end of each as a probe pin while tilting are provided, and each first contact terminal on the flexible board is connected to each contact terminal of the card board. As a result, there is an effect that it is possible to realize a probe card having a configuration suitable for a probe test of a multi-pin, narrow-pitch IC.

[Brief description of drawings]

FIG. 1 shows the structure of an embodiment of a probe card having the structure of the present invention.

FIG. 2 is a schematic diagram of a flexible substrate for a probe card.

FIG. 3 shows a manufacturing process of a flexible substrate and a probe pin for a probe card.

[Explanation of symbols]

 10 Stainless Plate 11 Copper Layer 12 Photoresist 13 Photomask 14 Probe Pin 15 Film 20 Printed Circuit Board 21 Ground Conductor 22 O-ring 23 Clamper 24 Bolt 25 Support Plate 26, 27 Insulation Sheet 28 Clamper 29 Volt 30 IC

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Etch Dun Higgins United States, Arizona, Gilbert, Suite 101, North Tech Boulevard 1478 in Fresh Quest Corporation (72) Inventor Pete Normington United States, Arizona, Gilbert, Sweet 101, North Tech Boulevard 1478 in Fresh Quest Corporation (56) References JP-A-60-147192 (JP, A) JP-A-62-242389 (JP, A)

Claims (3)

[Claims] 1. A plurality of wiring patterns formed directly or indirectly by a plating process, each of the wiring patterns having a front end exposed without being supported by a substrate and being exposed on the way or at a rear end side. A flexible board having contact terminals, a card board having a plurality of pattern wirings each provided with a second contact terminal that contacts each of the first contact terminals, and each of the tip portions as a probe pin. A support plate for supporting the probe card, wherein each first contact terminal on the flexible substrate is connected to each second contact terminal on the card substrate. 2. The flexible substrate is composed of four portions each having a trapezoidal shape or a shape similar to the trapezoidal shape, and these four portions are arranged in a rectangle with the shorter side of the two parallel sides being the inside. The side on the shorter side corresponds to the arrangement of the contact pads of the IC and forms a rectangular opening which is slightly larger than this, and each of the tip portions projects along each side of the opening, and each of the contact terminals is rearward. It is arranged along one side of the rectangle on the end side, the pitch of the contact terminals is larger than the pitch of the tip portions, and the support plate supports each of the four portions of the flexible substrate. The probe card according to claim 1, wherein the probe card comprises four parts each having a trapezoidal shape or a shape similar thereto. 3. The probe card according to claim 2, wherein the wiring pattern is Ni formed by electrolytic plating or an alloy thereof, and a highly conductive metal is attached to the outside of Ni.