JPH0750321A - Probe card - Google Patents

Abstract

PURPOSE:To provide a probe card in which fine end sides of many probe needles are arranged and supported at a fine pitch corresponding to electrodes of an element to be inspected and thick base end sides of the needles are well arranged and fixed in a flat area as narrow as possible without interfering with each other while suppressing bents of the needles at the intermediate portions to a minimum limit. CONSTITUTION:Many probe needles 31 whose ends are brought into press contact with many electrode pads arranged at a fine pitch of a semiconductor chip to be electrically connected are arranged and supported at a fine pitch P corresponding to the electrodes on an electrode arranging center line O of the chip by thinning end sides 31a, increasing in thickness the base end side 31c and inserting the sides 31a of the needles 31 to a guide plate. The sides 31a are bent at upper parts, and the sides 31c are alternately deviated from the line O to both sides and arranged fixedly on a printed board 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe card used in a probe device for inspecting the electrical characteristics of an object to be inspected such as a semiconductor wafer.

[0002]

2. Description of the Related Art As is well known, in a semiconductor manufacturing process, a large number of chips (semiconductor devices) having a predetermined circuit pattern are arrayed and formed on a semiconductor wafer by using a precision photographic technique or the like. The inspection (test determination) of the electrical characteristics of these chips is performed by a probe device (also known as a wafer prober) in the state of the semiconductor wafer before each chip is divided. As a result of this inspection, only semiconductor chips that are determined to be non-defective are sent to the next bonding and packaging steps to improve the yield of final products.

Here, the probe device is disclosed in JP-A-64
As disclosed in Japanese Patent Publication No. 73632/1993, the main stage is provided with a wafer mounting table configured to be movable and controlled in the XYZ-θ directions, and above the wafer mounting table. A probe card having a large number of probe needles corresponding to the electrode pads of the chip of the semiconductor wafer is fixedly supported by.

Then, a semiconductor wafer, which is an object to be inspected, is placed on the wafer mounting table, and the wafer mounting table is placed in XYZ.
The tip of each probe needle of the probe card is brought into contact with the electrode pad of each chip on the semiconductor wafer held on the upper surface by controlling the movement in the −θ direction, and the tip of each probe needle of the probe card is placed above the probe card through the probe needle. The tester head and the external tester are electrically connected to each other, and the tester measures and inspects the electrical characteristics of the semiconductor chip.

The probe card used in such a probe device is mainly of the oblique needle type in which the needle bars of the probe needles are obliquely attached to the printed circuit board. With the increase in integration, the number of electrode pads per unit area of a chip formed on a semiconductor wafer is increasing, and the size and arrangement interval of the electrode pads are decreasing. With the probe card, there is a limit to the number of probe needles that can be mounted, and it has become impossible to deal with this problem.

Therefore, recently, in place of the oblique needle type probe card, for example, a vertical needle type high density probe for multi-pins disclosed in Japanese Patent Publication No. 28828/1988 and No. 28862/1988. Card (VTP
C) has been developed and is being put to practical use.

In this vertical needle type probe card,
Insert a large number of probe needles through the central opening of the printed circuit board, bend the base end part in an arch shape from the middle of each probe needle, and connect and fix it to the conductive pattern around the printed circuit board by soldering. , Insert the middle part of each probe needle into the small hole of the fixing plate under the central opening of the printed circuit board, fix it with epoxy resin etc., and insert the tip side into the small hole of the lower needle guide part. Let With this, since the tip side part from the midway fixed part of each probe needle is arranged in a state substantially vertical to the object to be inspected, the number of mounted probe needles is significantly increased as compared with the above-mentioned oblique needle type, that is, It is possible to narrow the pitch of mounting needles and increase the number of mounting needles.

By the way, recently, as semiconductor elements such as semiconductor chips used in supercomputers have become more highly integrated, miniaturization of electrode pads necessary for in-chip inspection and fine pitch arrangement have been advanced. The size of the electrode pad is about 60 μm square, and the array pitch is about 150 to 500 μm, which is the subject of inspection. To cope with this, the probe tip of the probe needle is 15 μm.
It is necessary to mount a large number of ultrafine probe needles having an outer diameter of about 50 to 150 μm, which are sharpened to about m, at a fine pitch corresponding to the arrangement of the electrode pads.

Moreover, each probe needle is made of an alloy of gold and copper (Au-Cu) or the like in order to reduce contact resistance and durability, and is arranged from the needle fixing portion to the tip side portion (vertically arranged. Even though the part that buckles due to overdrive) is about 70 μm extra fine as mentioned above, the base end side above it is molded one step thicker (150 to 500 μm) in order to increase rigidity strength and reduce conductor resistance. There is a need to.

[0010]

By the way, in the above-mentioned ultra-high-density probe card, the ultra-fine tip side portions of a large number of probe needles are inserted into the needle guide portion and are located on the center line of the electrode array of the device under test. Even if the electrodes can be arrayed and supported at a fine pitch corresponding to the electrodes, the thick proximal end portions of the probe needles interfere with each other by contacting each other because the mutual spacing is too narrow compared to the outer diameter dimension, and the probe tip pattern Since it is impossible to fix the array in the above manner, it was necessary to bend each probe needle in the middle to make it larger and smaller and to diffuse and fix the base end side portion in a wide range.

Particularly, the base end side portion of each probe needle is directly fitted to the pattern electrode of the printed circuit board from the lower side without being arched above the printed circuit board and is connected and fixed by soldering. When considering a probe card of the type, it is necessary to form holes for connecting and fixing the thick base end side of each probe needle on the printed circuit board at a fine pitch according to the needle tip pattern. Is too narrow to provide sufficient space, which is not possible due to the limitations of the printed circuit board material and hole processing technology.

The present invention has been made in view of the above circumstances, and an object of the invention is to insert the ultrafine tip side portions of a large number of probe needles into a needle guide portion and to place the electrodes on the center line of the electrode array of the device under test. The probe needles can be arrayed and supported at a fine pitch, while minimizing the bending in the middle of each probe needle, while preventing the thick proximal end portions of each probe needle from interfering with each other and within a flat area as narrow as possible. An object of the present invention is to provide a probe card which can be properly arranged and fixed, and which is particularly suitable as a direct-attached type.

[0013]

In order to achieve the above-mentioned object, the present invention provides a large number of probe needles for electrically connecting by connecting the tips to a large number of electrodes arranged at a fine pitch of an object to be inspected. In the probe card mounted on the card body, each probe needle has a thin tip end side portion and a thicker base end side portion from the middle, and the thin tip end side portion of each probe needle is used as a needle guide portion of the card body. It is inserted and supported on the center line of the electrode array of the device under test at a fine pitch corresponding to the electrodes, and is bent at the upper part of the tip side part thereof, and the thick base end side part above the card body is bent. In the needle fixing part, one or two electrodes are alternately biased to both sides from the center line of the electrode array of the object to be inspected and arrayed and fixed.

The probe card of the present invention is a vertical needle type in which the thin tip side portions of the large number of probe needles are inserted into the needle guide portion of the card main body and supported substantially vertically so as to be buckled with respect to the object to be inspected. Is characterized in that.

In the probe card of the present invention, the thick base end portions of the large number of probe needles are fitted straight to the pattern electrodes of the printed circuit board of the card body from the lower side of the printed circuit board and fixed by soldering. It is a direct mounting type.

[0016]

With the probe card having the above-described structure, in many probe needles, the tip side portion is thin and the base end side portion is thick from the middle in order to increase the rigidity and reduce the conductor resistance. , The thin tip side portion of each probe needle is inserted into the needle guide portion of the card body and is arrayed and supported on the electrode array center line of the DUT at a fine pitch corresponding to the electrode, while the tip end portion of the The upper portion is bent, and the thick base end side portion above the upper portion is bent to the needle fixing portion of the card body, one on each side from the center line of the electrode arrangement of the device under test or 2
Since each probe needle is alternately biased and fixed, that is, the thick proximal end portion of each probe needle is alternately arranged "one by one" or "two needles", so that it is arranged in the middle of each probe needle. While keeping the bending of the probe needle to a minimum, there is an appropriate interval without interfering with the thick proximal end side of each probe needle, and it is possible to successfully arrange and fix it in a narrow flat area as close as possible to the needle tip pattern. In particular, as a direct-attached type probe card, holes for fixing and connecting to the printed circuit board on the base end side of a large number of fine-pitch-arranged probe needles can be easily formed with sufficient mutual spacing. Optimally, the large number of connection fixing holes can be suppressed from spreading over a wide range.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
2 and FIG. First, FIG. 2 is a cross-sectional view showing a part of a probe device (also known as a wafer prober) for inspecting (testing) the electrical characteristics of a chip (semiconductor device) formed on a semiconductor wafer W in a semiconductor manufacturing process.

In this probe apparatus, a wafer mounting table 1 is provided on a main stage in the center of the base (not shown) so that the movement of the wafer mounting table 1 can be controlled in the XYZ-θ directions.
A semiconductor wafer W, which is an object to be inspected, can be vacuum-chucked on the upper surface of the wafer mounting table 1 and positioned and held in a horizontal state.

On the other hand, above the wafer mounting table 1, a probe card 2 of the present invention is fixed to a head plate and an insert ring provided in parallel with the base through a card holder (neither is shown). While being supported, the contact ring 3 and the test head 4 are installed on the upper side thereof and connected to the external tester 5.

The probe card 2 is a semiconductor wafer W.
In order to cope with the high density and high integration of the probe needles 31, the number of the probe needles 31 mounted is greatly increased, that is, the needle pitch is narrowed and the number of the mounted probe needles is increased. It is a direct attachment type probe card.

The structure of the probe card 2 will be described below. First, as a probe card main body, a printed circuit board 21 is concentrically fixed to the printed circuit board 21 below the printed circuit board 21 with positioning pins and fastening screws (not shown). Ring-shaped fixed blocks 22, 23, 24, 25, and a needle guide plate 27 horizontally fixed by being clamped by the fixed blocks 23, 24 near the upper part of the internal space of these fixed blocks. Fixed block 25 at the lower end of the space
Upper and lower guide plates 28, which are fitted horizontally to the guide plate 28,
29 and 29 are provided.

The needle guide plates 27, 28, 29 are insulative resin plates, respectively, and have small holes 27a, 28a, 29a (see FIG. 1) for needle insertion as needle guide portions, respectively. In addition, a large number of holes are arranged corresponding to the arrangement, that is, on the arrangement center line O of the electrode pads E of the wafer W to be inspected at a fine pitch P corresponding to the electrode pads E. On the other hand, as shown in FIG. 1, the printed circuit board 21 is provided with perforated pattern electrodes 21a so that the perforated pattern electrodes 21a are perforated. A large number of the perforated pattern electrodes 21a are alternately arranged on the both sides from the center line O of the electrode array by a predetermined distance, and are arranged in a "small-footed" manner.

A large number of probe needles 31 are provided on the card body of the probe card 2 (only five are shown in FIG.
Actually, more than 1,000 in about 15 mm ² ) are arranged and mounted at a fine pitch along a grid pattern.

That is, first, as shown in FIG. 1, each probe needle 31 is made of an alloy of gold and copper (Au-Cu) and has a large electrode pad E in order to reduce contact resistance and durability. Is about 60 μm square, and the array pitch is about 150 to 5
In order to inspect a highly integrated and high-density semiconductor chip of about 00 μm, the tip side part (lower side part) 31a
Is made extremely thin (outer diameter d = 70 μm), and the tip 31b of the tip is sharpened into a conical shape, and its diameter d '
Is molded into a flat surface of about 15 μm.

Further, in order to increase the rigidity and reduce the conductor resistance, the probe body 31 has a required outer diameter dimension in which the base end side portion 31c extending upward from the middle is one step thicker than the tip end side portion 31a ( The outer diameter D is about 200 μm). Moreover, each probe needle 31 is bent into a substantially crank shape at the upper portion (root portion) of the thin distal end side portion 31a as described above, and the center of the proximal end side portion 31c is bent by the bent portion 31d. It is eccentric for a certain distance from the center of.

The thin tip side portions 31a of the probe needles 31 having such a configuration are vertically inserted into the small holes 27a of the needle guide plate 27 one by one from above, and the needle tips 31b thereof are further below the guide plate 28, The probe is inserted into the small holes 28a, 29a of 29 and slightly protrudes (about 250 .mu.m) downwardly. In this state, the needle guide plate 27 is filled with an adhesive 32 such as an epoxy resin and the probe is inserted. The middle of the needle 31 is adhesively fixed. As a result, the tip side portion 31a from the adhesive fixing portion in the middle of each probe needle 31 is substantially perpendicular to the wafer W to be inspected, and the electrode pad E on the array center line O of the electrode pad E of the wafer W. E is arranged and supported at a fine pitch P corresponding to E, and a buckling portion 31e having a length of about 10 mm is secured in the middle of the tip side portion 31a (between the guide plates 27 and 28). There is.

Further, when the probe needles 31 are bonded and fixed in the middle with the adhesive 32 such as epoxy resin as described above, the substantially crank-shaped bent portions 31d in the middle are alternately turned in opposite directions. And fix them by adhesive. As a result, the thick proximal end portions 31c of the probe needles 31 are alternately displaced from the electrode array center line O on both sides by a predetermined distance and are arranged in a "small-footed" manner, and the holes of the printed circuit board 21 are directly arranged. The open pattern electrodes 21a are fitted straight one by one from the lower side, and their ends (upper ends) are connected and fixed to the pattern electrodes 21a by soldering.

Thus, in the many probe needles 31, the distal end side portions 31a are thin and the proximal end side portions 31c are thick from the middle, but the thin distal end side portions 31 of each probe needle 31.
a is a small hole 27a, 28a, 2 in the needle guide portion of the card body.
While being inserted through 9a to be arrayed and supported on the electrode array center line O of the device under test at a fine pitch P corresponding to the electrode E,
The upper part of the tip side part 31a is bent, and the thick base end side part 31c above the part is fixed by the adhesive 32, which is the needle fixing part of the card body, and the pattern electrode of the printed board 21 above it. 21a, the electrodes are arranged so as to be deviated one by one from both sides of the electrode arrangement center line O, that is, the thicker proximal end portions 31c of the probe needles 31 are alternately arranged one by one in a "drip-foot shape". Since the probe needles 31 are bent in the middle, the thick proximal ends 31c of the probe needles 31 do not interfere with each other and have appropriate intervals M and N. Therefore, it becomes possible to successfully arrange and fix in a narrow flat area as close as possible to the needle tip pattern.

For this reason, in the case of a direct-attached type probe card shown in particular, each pattern electrode 21a of the printed board 21 into which the thick base end side portions 31c of a large number of probe needles 31 arranged in a fine pitch are fitted. Optimum because the holes can be easily formed with a sufficient space between them and the large number of holes can be prevented from spreading in a wide range. This makes the entire probe card compact and each probe needle 3
1 can be shortened, and excellent testing characteristics can be obtained.

In the testing, the semiconductor wafer W is mounted on the wafer mounting table 1 of the probe apparatus, the wafer mounting table 1 is controlled to move in the XYZ-θ directions, and the upper surface of the wafer mounting table 1 is controlled. The probe tip of each probe needle 31 of the probe card 2 is brought into contact with the electrode pad E of each chip on the held semiconductor wafer W, so that the probe needle 31 and the contact ring 3 arranged above the probe card 2 and the test head. The external tester 5 is electrically connected via the circuit 4, and the tester 5 is used to measure and inspect the electrical characteristics of the semiconductor chip.

When the wafer mounting table 1 is raised to bring the surface of the electrode pad E of the chip of the semiconductor wafer W into contact with the tip of each probe needle 31, overdrive (elevation of the wafer mounting table 1) is further applied there. Then, while each probe needle 31 is buckled between the guide plate 27 and the lower guide plate 28 as shown by the imaginary line in the drawing, a required contact surface pressure with respect to each electrode pad E is secured, and in this pressure contact state. By further finely displacing the wafer mounting table 1 several times in the horizontal direction and scraping off the oxide film on the surface of the electrode pad E with a needle tip, a reliable electrical connection between each probe needle 31 and the electrode pad E can be obtained. To do.

FIG. 3 shows another embodiment of the probe card according to the present invention. Here, as shown in the drawing, a large number of probe needles 31 similar to those described above are provided with thin leading end side portions 31a of a needle guide of the card body. And is arranged and supported on the center line O of the electrode array of the device under test at a fine pitch corresponding to the electrodes, and is bent in a substantially crank shape at the upper portion of the tip side part thereof.
The thick base end side portion 31c above it is mounted on the printed circuit board which is the needle fixing portion of the card body, and the electrode arrangement center line O of the object to be inspected.
This is a structure in which two pieces are alternately biased from the top to the both sides and fixedly arranged in a “two small legs.” With this structure, the same operational effect as described above can be obtained.

[0033]

Since the probe card of the present invention is constructed as described above, the ultrafine tip side portions of a large number of probe needles are inserted into the needle guide portion and the electrodes are arranged on the center line of the electrode array of the device under test. The probe needles can be arrayed and supported at a fine pitch, while minimizing the bending in the middle of each probe needle, while preventing the thick proximal end portions of each probe needle from interfering with each other and within a flat area as narrow as possible. The array can be fixed well, and it is most suitable as a direct mounting type.

[Brief description of drawings]

1A and 1B show an embodiment of a probe card of the present invention, in which FIG. 1A is a partial plan view, and FIG. 1B is an enlarged vertical sectional view of the same part.

FIG. 2 is a partially omitted sectional view of a probe device using the probe card of the above-mentioned embodiment.

FIG. 3 is a partial plan view showing another embodiment of the probe card of the present invention.

[Explanation of symbols]

2 ... Probe card, 21, 32 ... Needle fixing part of card body (21 ... Printed circuit board, 32 ... Adhesive), 21a ... Pattern electrode, 27, 28, 29 ... Guide part (guide plate), 31 ... Probe needle, 31a ... Tip side portion, 31c ...
Base end side portion, 31d ... Bent portion, O ... Electrode array center line, P ...
Pitch, W ... Inspected object (of semiconductor wafer), E ... Electrode pad.

Front Page Continuation (72) Inventor Kunio Sano 1 2381 Kitashitajo, Fujii-cho, Nirasaki City, Yamanashi Prefecture Tokyo Electron Yamanashi Co., Ltd.

Claims (3)

[Claims] 1. A probe card in which a plurality of probe needles for electrically connecting to a plurality of electrodes arranged at a fine pitch of an object to be inspected by pressing the tips are mounted on a card body, wherein each probe needle is Each tip side portion is thin and the base end side portion is thick from the middle, and the thin tip side portion of each probe needle is inserted into the needle guide portion of the card body and the electrodes are arranged on the center line of the electrode array of the device under test. It is arranged and supported at a corresponding fine pitch, and it is bent at the upper part of the tip side part, and the thick base end side part above it is fixed to the needle fixing part of the card body on both sides from the center line of the electrode arrangement of the DUT. A probe card in which one or two of them are alternately biased and fixed in an array. 2. The thin tip side portions of a large number of probe needles are
2. The probe card according to claim 1, wherein the probe card is inserted into a needle guide portion of the card body and supported substantially perpendicularly to an object to be inspected. 3. A thick proximal end portion of a large number of probe needles is
The probe card according to claim 2, wherein the probe card is straightly fitted from below the printed circuit board of the card body to the pattern electrode of the circuit board and fixedly connected by soldering.