JPH06334006A - Probe card - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize a probe card that is suitable for a probe test of an IC with a large number of pins and a narrow pitch, and has a structure in which the pin tips are even and a sufficient contact pressure can be secured. [Structure] A plurality of wiring patterns formed by a plating process are provided, and respective tip portions 14 of these wiring patterns are provided.
d is exposed without being supported by the substrate 15 and is exposed to the rear end side of the first side.
Flexible board 50 having contact terminals, a card board (30 + 40) having a plurality of wiring patterns each provided with a second contact terminal that contacts each first contact terminal, and a tip portion of the flexible board 50. 14
The flexible substrate 50 includes a clamper 60 that supports the portion on the d side from above, and a support body 20 that supports the respective tip portions 14d as probe pins.
A portion near the tip of 4d is pressed by the clamper 60 to obtain a contact force as a probe pin.

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 step of arranging these tapered probe pins in a fan shape and attaching them to the substrate, and a step 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, the performance of the product tends to vary due to variations in pin tip height and the like, and the 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 as carefully as a supreme work of art, but it is still necessary to readjust the height and position of the pin tip. 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. Furthermore, there is a probe card of the type that gives up the contact part as a pin and attaches a pad to the wiring pattern on the resin substrate and presses it, but this cannot secure so-called overdrive, so contact pressure (as a probe pin The contact force is unstable and the contact resistance is unstable, resulting in poor reliability.

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 the above-mentioned problems of the prior art, and is suitable for a probe test of an IC having a large number of pins and a narrow pitch, and the heights of the pin tips are aligned to ensure a sufficient contact pressure. It is to realize a probe card with a configuration that can be done.

[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. Card having a plurality of wiring patterns, wherein the flexible substrate is fixed at a portion on the first contact terminal side so that each of the first contact terminals is connected to each of the second contact terminals. A board, a clamper for supporting the tip end side portion of the flexible board from above, and a rear portion thereof fixed to the card board, and a front portion thereof. The clamper is fixed, and the flexible substrate is directly or indirectly sandwiched between the front portion and the clamper, and a support body that supports each of the distal end portions of the flexible substrate as a probe pin is provided. A portion of the substrate near the tip of the tip is directly or indirectly pressed by the clamper to obtain a contact force as a probe pin.

[0007]

In the probe card of the present invention having such a structure, the supporting member supports the tip of the wiring pattern of the flexible substrate as a probe pin. This allows
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. Furthermore, a flexible substrate having a wiring pattern having a tip portion as a probe pin is manufactured based on a plating process. Therefore, even when the number of pins is increased with a narrow pitch, the heights of the probe pins are accurately aligned, which is suitable for a probe test of an IC with a large number of pins and a narrow pitch.

Moreover, a structure is adopted in which the portion near the tip of the tip portion is pressed by the clamper to obtain the contact force between the pad portion and the tip portion. Due to this fact and matching pin height,
Even with a thin pin, sufficient overdrive and contact pressure can be secured. Therefore, it is suitable for a probe test of an IC having a large number of pins and a narrow pitch, and the heights of the pin tips are even, so that a sufficient contact pressure can be secured.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1 to 5 show the configuration of the probe card. FIG. 1 is a cross-sectional view of the main part of one side of the probe card. FIG. 2 is a perspective view of a partial cross section. The cross-section hatching is omitted. Figure 3
FIG. FIG. 4A is a plan view of a main part in a state before mounting the clamper 70, and FIG. 4B is a plan view of a main part in a final state. FIG. 5 shows the flexible substrate 50, (a) is a front sectional view and (b) is a bottom view. The flexible substrate 50 is illustrated as the film 15 is transparent and the wiring pattern 14 and the like can be seen through.

Here, 14 is a wiring pattern formed by a plating process described later, 14d is a probe pin as the tip of the wiring pattern 14, and 15 is a film that supports the wiring pattern 14, and these are flexible as a unit. The substrate 50 is configured. Reference numeral 20 denotes a support made of stainless steel or brass, which has an inclined surface for receiving a portion of the flexible board 50 close to the probe pin 14d on the front side (right side in FIG. 1), and a horizontal mounting surface on the card board. To the rear (left in FIG. 1). This slope is
Seen from above, it has a trapezoidal shape with the short side at the front (see Fig. 2).

Reference numeral 30 denotes a hard reinforcing plate made of stainless steel, and reference numeral 40 denotes a printed circuit board having a wiring pattern on its upper surface. The printed circuit board 40 is reinforced by the reinforcing plate 30 to form a hard card board. Note that the reinforcing plate 30 may be omitted if the printed circuit board 40 is sufficiently hard. Reference numeral 60 denotes a trapezoidal plate clamper having a short side on the front side (see FIGS. 2 and 4) and further stacked on the insulating sheet 21 and the flexible substrate 50 stacked on the inclined surface of the support 20. In this state, the bolts 61 are attached to the support 20 (see FIG. 1). As a result, the portion of the flexible substrate 50 on the probe pin 14d side is fixed to the inclined surface of the support 20 from above, and the probe pin is supported from above at the front edge portion thereof.

Reference numeral 71 is an O-ring for securing contact pressure, 70 is a clamper, 72 is a bolt, and 80 is an image of an IC to be inspected. Contact terminals are provided on both sides of the wiring pattern on the upper surface of the printed board 40. One of the contact terminals is connected to the probe pin 14 of the flexible substrate 50.
d of the wiring pattern 14 connected to the rear end side contact terminal 14e of the wiring pattern 14 and the film 15 of the flexible substrate 50.
The O-ring 71, the clamper 70 and the bolt 71 are fixed from above to maintain the connection state with the wiring pattern 14. The other contact terminal of the wiring pattern on the upper surface of the printed board 40 is connected to the tester side by a card edge connection or a spring pin contact when the card is inserted into the prober. With this structure, the probe pin 1
Electrical connection between the IC 30 and the tester is secured via 4d and the like.

The support 20 is composed of four trapezoidal portions when viewed from above (see FIG. 4), and is attached to the lower part of the center of the reinforcing plate 30 of the card substrate with bolts 72 with their short sides inside. On the inclined surface, the tip of the flexible substrate 50 is attached to the probe pin 14 as described above.
Supported as d. Then, when this probe card is driven by the prober, the probe pin 14d comes into contact with the contact pad of the IC 80, and further overdrive is applied, the inclined probe pin 14d
Slightly scratches the IC80 contact pad. As a result, reliable contact can be secured and the inspection result can be trusted. When a bump is provided on the contact pad portion of the IC 80 or the tip of the probe pin, overdrive is applied within the range of the height of the bump, so that the probe pin does not need to be inclined in advance. . Alternatively, it may be inclined in the opposite direction.

FIG. 5 shows a schematic diagram of the flexible substrate 50, which 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
The IC 80 has a substantially rectangular opening larger than the contact pad arrangement portion of the IC 80 (see 15b in FIG. 5). Then, the respective tip portions (14d etc.) project along the respective sides of the opening 15b. By having this opening, the tip portion functions as a probe pin, and the tip of the probe pin 14d and the IC 80
It becomes possible to monitor the contact state with the contact pad. In addition, a cut may be provided in a corner of the opening so that the flexible substrate 50 can be easily deformed without being damaged. Further, this may be configured as a combination of four trapezoidal shapes divided substantially along a diagonal line (see the alternate long and short dash line in FIG. 5) (see the development view in FIG. 3).

Further, the position of the tip of the probe pin 14d is provided so as to correspond to the arrangement of the contact pad of the IC 80, and a wide pitch corresponding to the arrangement of the contact terminal of the printed circuit board 40 is provided on the rear end side of the wiring pattern 14 continuous with this. Is provided with a contact terminal 14e. As a result, it is possible to achieve the matching between the fine and narrow pitch pads of the IC and the not so fine pitch of the printed circuit board, and thus the fine and narrow pitch pads of the IC and the wide-pitch spring pins on the tester side, etc. Can be matched with. 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 on the corresponding portions.
The same applies to the support 20. This can also be composed of a combination of the individual parts corresponding to each of the four trapezoidal parts, which are determined according to the arrangement of the contact pads of the IC 80.

Next, a method of manufacturing the flexible substrate 50 (wiring pattern 14 + film 15) will be described. FIG. 6 shows a schematic sectional view in each step. In addition,
Hereinafter, the probe pin is simply referred to as a pin, the wiring pattern is referred to as a pattern, and the wiring pattern 14 including the pin 14d and the pattern 14e is also referred to as a pin 14. Also, pin 1
The entire 4th grade and the film 15 are pin film bodies (14+
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. 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, a thin copper layer 11 as the first metal layer is formed on the stainless steel plate 10 as the substrate layer by electrolytic plating. 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 FIG. 6A), and is exposed through a mask 13 (see FIG. 6B). 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. 6C).

In the electrolytic plating step, the void 12a above the copper layer 11 which appears in the portion not covered with the resist mask is used.
Then, Ni is deposited by electrolytic plating to grow (see (d) of FIG. 6). After the completion of Ni plating, the resist 12 is removed and the mask is removed (see FIG. 6D). 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. 6).
(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. 5). The film 15 is bonded to the pin 14 with the opening 15b corresponding 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 off 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, the copper layer 11 is removed without damaging the Ni layer (14) by using an etching solution having a high selection ratio. This allows the film 15
A portion including the pin 14 and the pin 14 is separated from the stainless layer 10 and the copper layer 11.

The probe pin 1 manufactured in this way
4 has a substantially rectangular cross section (usually 50 μm × 50 μ
m). 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 80 μm).

Also, 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. It is also possible to use the pin film body 22 in a state of being turned upside down, and in this case, the side surfaces 14a, 14b,
The side surface on the opposite side of 14c serves as a contact surface, and in this case also, the heights of the pin tips are almost the same as in the above case.

Further, the side surfaces 14a, 14b, 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 steel 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. And, a pin film body (14 + 1 with such pins
5) That is, the flexible substrate 50 is the film 1
5 functions as a support plate that supports the probe pin 14d. Therefore, since these can be clamped as a unit, no craftsmanship is required when manufacturing the probe card.

A method of supporting the flexible substrate 50 thus manufactured will be described. It is particularly preferable that a portion near the tip of the probe pin 14d, specifically, a portion 5 mm from the tip is pressed by the front end of the clamper 60, and a portion 5 mm behind the clamper 60 is pressed by the support 20. By pressing the clamper 60 on the portion of the flexible substrate 50 where the probe pins 14d have the same height, close to the tips of the probe pins 14d,
The contact pressure of 1 gf or more required as the contact force as the probe pin can be obtained from the probe pin 14d.

In addition, since the support 20 and the clamper 60 are different from each other in the position where the flexible substrate 50 is pressed, the deformable portion increases and the spring property increases, so that sufficient overdrive can be secured. This also reduces the variation in contact pressure, and even if the maximum contact pressure within the variation is suppressed to some extent, the minimum contact pressure within the variation can be increased. A sufficient contact pressure can be secured for the pin.

The specific numerical values here are examples, and in short, the flexible substrate 5 of the clamper 60 is used.
The portion that holds 0 and is the closest to the tip of the probe pin 14d is the flexible substrate 5 of the support 20.
It suffices if it is closer to the tip of the probe pin 14d than the portion that supports 0 and is closest to the tip of the probe pin 14d. 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.

[0031]

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 card substrate having a plurality of wiring patterns, each of which is exposed without being exposed and has a first contact terminal on a rear end side thereof, and a second contact terminal which contacts each of the first contact terminals. And a clamper that supports the tip end side portion of the flexible board from above, and a support that supports each tip end as a probe pin, and presses the portion of the flexible board near the tip end of the flexible board with the clamper. To obtain the contact force as a probe pin. As a result, there is an effect that it is possible to realize a probe card which is suitable for a probe test of an IC having a large number of pins and a narrow pitch, and in which the heights of the pin tips are even and a sufficient contact pressure can be secured.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of one side of an embodiment of a probe card having the configuration of the present invention.

FIG. 2 is a perspective view of a partial cross section of the probe card.

FIG. 3 is a development view of the probe card.

FIG. 4 shows (a) of the probe card.
6A is a plan view of an essential part in a state before attachment of the clamper 70, and FIG. 7B is a plan view of an essential part in a final state.

FIG. 5 is a schematic view of a flexible substrate for a probe card, (a) is a front sectional view and (b) is a bottom view.

FIG. 6 shows a manufacturing process of a flexible substrate and a probe pin for a probe card.

[Explanation of symbols]

 10 Stainless Steel Plate 11 Copper Layer 12 Photoresist 13 Photomask 14 Pin (Wiring Pattern) 14d Probe Pin 14e Contact Terminal 15 Film 15b Opening 20 Support 21 Insulation Sheet 30 Reinforcement Plate 40 Printed Circuit Board 50 Flexible Board 60 Clamper 61 Bolt 70 Clamper 71 O-ring 72 bolt 80 IC

Front Page Continuation (72) Inventor Etch Dun Higgins United States, Arizona, Gilbert, Sweet 101, North Tech Boulevard 1478 In Fresh Quest Corporation (72) Inventor Pete Normington United States, Arizona, Gilbert, Sweet 101, Nostech Boulevard 1478 Fresh Quest Corporation

Claims (2)

[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 substrate having a contact terminal of, and a plurality of wiring patterns each provided with a second contact terminal that comes into contact with each of the first contact terminals,
A card substrate on which the flexible substrate is fixed at a portion on the first contact terminal side so that each of the first contact terminals is connected to each of the second contact terminals; A clamper for supporting the tip end side portion from above, and a rear portion fixed to the card substrate, the front portion thereof being fixed to the clamper, and the front portion and the clamper directly or directly to the flexible substrate. A support body that holds the tip ends of the flexible boards as probe pins by indirectly sandwiching the flexible board; and a portion of the flexible board near the tip ends of the flexible boards directly or indirectly by the clamper. A probe card that is pressed to obtain a contact force as a probe pin. 2. The probe card according to claim 1, wherein
A portion of the clamper that presses the flexible substrate and is closest to the tip of the tip is more than a portion of the support that supports the flexible substrate and that is closest to the tip of the tip. A probe card characterized by being close to the tip of the tip.