JPH1048256A - Inspection head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inspection head in which the electrical contact resistance is decreased between a probe element and an object to be inspected while reducing the manufacturing cost. SOLUTION: The inspection head used an elastically deformable sheet-like member 30 and a wiring part 32 formed on the sheet-like member 30 by an appropriate means, e.g. print wiring technology, as a probe supporting means. A metal probe 16 is employed as a probe element touching the electrode of an object to be inspected and the forward end of each probe 16 is projected oppositely to the wiring part 32 from the sheet-like member 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an inspection head used for testing the electrical characteristics of a flat test object such as an integrated circuit.

[0002]

2. Description of the Related Art An integrated circuit on a semiconductor wafer, an integrated circuit separated from a semiconductor wafer into a chip, and an integrated circuit on which a chip has been mounted are subjected to an energization test to determine whether the circuit operates according to specifications. Is done. This type of energization test is performed by measuring electrical characteristics using an inspection head called a probe board, a probe card, or the like.

A test head of this kind includes a plurality of probe elements which are brought into contact with the electrical connection portions of the integrated circuit, that is, the connection pads, in a state where current can flow. The probe element is 1
In order to ensure that high-frequency signals of GHz or higher are applied to the integrated circuit and that the corresponding electric signals can be obtained from the integrated circuit, a function of breaking through an electrical insulating film such as aluminum oxide of a connection pad of the integrated circuit is provided. It is required to have.

[0004] The above requirements are generally achieved by a so-called rubbing action, in which the surface of the connection pad is rubbed with the tip of the probe element. Such a rubbing action may cause the probe element to warp slightly, with the connection pads of the integrated circuit and the tip of the probe element in contact with each other and slightly excessively pressed.
This is caused by relatively displacing the contact area between the connection pad of the integrated circuit and the tip of the probe element.

As an inspection head used in this kind of energization test, a plate-shaped head using a flat wiring board which cannot be elastically deformed (for example, Japanese Utility Model Application Laid-Open No. 58-114679) and an elastically deformable head are used. A film-shaped head using a film-shaped wiring board (for example, see JP-A-63-184349)
No.).

[0006] The plate-shaped head uses a plurality of tapered probe needles made of thin metal wires as probe elements, and attaches the probe needles to a flat wiring board that cannot be elastically deformed. On the other hand, the film-shaped head forms a film-shaped wiring substrate which can be elastically deformed by a so-called printed wiring technique such as a photolithography method, a printed wiring method, etc., in which a plurality of probe elements are used for manufacturing an integrated circuit. ,
A transmission line portion formed on the wiring board, that is, a part of the wiring portion is used as a probe element.

According to the plate-shaped head, since the probe needle can be made of a hard material such as tungsten, the rubbing action between the tip of the probe element and the surface of the contact pad is large, and as a result, the contact The electrical contact resistance of the probe element to the pad is a small value close to the desired value as compared to the film head. However, with a plate head,
Since the pressing force of each probe element against the connection pad (and thus the rubbing force) varies depending on the taper angle of each probe needle, the length of each probe needle protruding from the wiring board, etc., the pressing force of all probe needles is constant. As a result, it is difficult to fabricate a probe needle and attach it to a wiring board, which is expensive.

On the other hand, according to the film head,
Since the wiring section and the probe element can be manufactured by the printed wiring technique, the cost is lower than that of the plate head. However, in the conventional film head, simply using the tip of the wiring portion as a pressing portion against the connection pad causes a large rubbing action between the bump and the contact pad surface so as to break through the electrical insulating film on the surface of the contact pad. The desired good electrical contact cannot be obtained between the probe element and the contact pad because the electrical contact resistance between the probe element and the contact pad is lower than that of the plate head. Very large.

In order to solve the above-mentioned problems of the film head, a film head has been proposed in which a protruding portion, that is, a bump is formed at the tip of each probe element, and the bump is used as a pressing portion to a contact pad (for example, see Japanese Patent Application Laid-Open No. H11-157,086). JP-A-4-
No. 363671). However, in such a film-shaped head, it is difficult to use a high-hardness material such as tungsten for the printed wiring technology in the bump, so that the bump must be made of a material such as nickel, and as a result, the contact pad A sufficient rubbing action between the bump and the surface of the contact pad cannot be obtained between the bump and the surface of the contact pad so that the desired good electrical contact can be obtained by breaking through the electric insulating film on the surface of the contact element. The reduction in electrical contact resistance is small.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the electrical contact resistance between a probe element and a device to be inspected and to reduce the manufacturing cost.

[0011]

An inspection head according to the present invention includes an elastically deformable probe support and a plurality of probe elements disposed on the probe support. The probe support includes an elastically deformable sheet member and a plurality of wiring portions formed on one surface of the sheet member. Each prog element is a metal probe needle corresponding to the wiring part and electrically conductively attached to the corresponding wiring part, and the tip of each probe needle is opposite to the wiring part side from the sheet-like member. It protrudes to the side.

The transmission line portion, that is, the wiring portion, can be formed in a sheet-like member by a so-called printed wiring technique such as a photolithography method and a printed wiring method used for manufacturing an integrated circuit. Each probe needle can be made of a thin metal wire such as a tungsten wire, and can be electrically connected to the corresponding wiring portion by a suitable means such as solder or conductive adhesive.

When testing a flat test object such as an integrated circuit, the tip of the probe needle and the test object are slightly excessively pressed. As a result, the corresponding portion of the sheet-shaped member (particularly, the corresponding wiring portion), and in some cases, the probe needle is further warped, so that the tip of the probe needle is slightly displaced in contact with the test object, A rubbing action of rubbing the test object occurs at the tip of the probe needle. as a result,
An electrical insulating film on the surface of the electrode, such as a connection pad of an integrated circuit, is broken by the tip of the probe needle, and good electrical contact is obtained between the electrode and the probe needle.

According to the present invention, the elastically deformable sheet member and the wiring portion formed thereon are used as probe support means, and the metal probe needle is used as each probe element. Is protruded from the sheet-shaped member to the side opposite to the side of the wiring section, so that the electrical contact resistance between the probe element and the device under test is reduced, and the manufacturing cost is reduced.

The sheet-like member has a sheet-like metal plate capable of being elastically deformed, and an electric insulating layer formed on one surface of the metal plate, and a wiring portion formed on a surface opposite to the metal plate. Electrical insulating layer. Instead of this,
The sheet-shaped member is an elastically deformable sheet-shaped metal plate,
A first electric insulating layer formed on one surface of the metal plate, the first electric insulating layer having a wiring portion formed on a surface opposite to the metal plate side; And a second electric insulating layer formed on the surface of the first electric insulating layer on the side of the wiring portion. In any case, by connecting the metal plate to the ground, the intrusion of disturbance from the wiring portion can be prevented.

In any of the above-mentioned sheet-shaped members, the tip of the probe needle may be penetrated through the probe support or may extend through the inside of the surface of the probe support forming the opening. By doing so, it is possible to prevent disturbance from entering from the tip of the probe.

The preferred embodiment further includes a wiring board having a plurality of second wiring portions electrically connected to the wiring portion of the probe support. The wiring board and the sheet-shaped member have an opening in the center, and the sheet-shaped member is coaxially coupled to the wiring board such that the tip of the probe needle projects toward the side opposite to the wiring board. The sheet-like member is mounted on the wiring board by the mounting means.

The probe needles are arranged at the edges corresponding to the respective sides of the square, and the respective wiring portions of the probe support are extended from the corresponding probe needles to the outside of the sheet-like member. A notch extending toward the outside of the sheet-shaped member can be formed in the sheet-shaped member. This allows
The probe needle and wiring section are divided into multiple groups,
Independent warpage can be caused for each group.
However, a portion of the adjacent wiring portion on the probe needle side may be cut off to cause warpage for each wiring portion.

The rear end of each probe needle may be extended in parallel with the corresponding wiring portion. In this case, the probe needle also warps. However, instead of this, the rear end of each probe needle is inserted into a probe support, particularly a sheet-like member and a corresponding wiring portion, and is electrically connected to the wiring portion, such as solder, conductive adhesive, or the like. It may be attached by an appropriate means.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 5, an inspection head 10 includes an integrated circuit on a semiconductor wafer, an integrated circuit separated from the semiconductor wafer into chips, and an integrated circuit on which chips are mounted. It is used for a current test of a flat test object such as a circuit. The device under test includes a plurality of electrodes for connection such as connection pads.

The inspection head 10 includes a disk-shaped wiring board 12 that is not elastically deformable, a sheet-shaped probe support 14 that is elastically deformable, a plurality of probe needles 16 arranged on the probe support 14, Probe support 14 is connected to wiring board 1
And an annular mounting plate 18 supported by the second mounting plate 18.

The wiring board 12 has a wiring pattern on one surface (upper surface) of a plate 20 made of an electrically insulating material, a plurality of connectors 22 connected to a tester (not shown) on an outer peripheral edge, and has a circular shape. An opening 24 is provided at the center. Each connector 22 includes a transmission line portion of a wiring pattern, that is, a wiring portion 26.
Is electrically connected to The wiring pattern of the wiring board 12 can be formed by a printed wiring technique using a conductive material, and therefore, the manufacturing cost of the wiring board 12 is reduced.

A plurality of positioning pins 28 are provided on the wiring board 12 at equal angular intervals around the opening 24. Each pin 28 penetrates a portion between the wiring portions 26 of the wiring board 12 and protrudes on the side (downward) opposite to the surface on the side of the wiring pattern. Pin 28 may be a conductive material or a non-conductive material. The wiring section 26 corresponds to the probe needle 16.

The probe support 14 includes a circularly deformable sheet-like member 30 and a plurality of wiring portions 32 formed on one surface (upper surface) of the sheet-like member.
The sheet member 30 has a circular shape, and has a square opening 34 at the center corresponding to the shape of the object to be inspected. Each wiring part 32 is a transmission line part of a wiring pattern formed by a printed wiring technique using a conductive material.

In the illustrated example, the sheet-like member 30 is formed by a sheet-like metal plate 36 which can be elastically deformed, and an electric insulating layer 38 formed on one surface (upper surface) of the metal plate. . The metal plate 36 can be made of a spring material such as stainless steel or beryllium. The electrical insulation layer 38
It may be formed by bonding an electrically insulating sheet or film such as a polyimide material to the metal plate 36 or by applying an electrically insulating material to the metal plate 36. Such a sheet-like member 30 can also be manufactured by a printed wiring technique similarly to the wiring pattern,
Therefore, the manufacturing cost of the probe support 14 is reduced.

The wiring portion 32 is formed radially on the upper surface of the electric insulating layer 38, and extends continuously from the inner end to the outer end of the sheet-like member 30. The wiring section 32 corresponds to the wiring section 26 and the probe needle 16, and is formed in a pattern similar to the wiring section 26 of the wiring board 12.

The probe support 14 also includes a plurality of holes 40 through which the probe needle 16 passes, a plurality of holes 42 for receiving the pins 28, a plurality of projections 44 for connection, and an opening 34.
And a notch 46 extending radially outward from each corner. The hole 40 is in the edge around the opening 34 and the opening 3
4 are formed at an interval along the side forming 4.

Each of the projections 44 has a hemispherical shape, and is made of a soft conductive metal such as solder or gold.
2, the probe support 14 is pressed against the connection portion 48 as shown in FIG. 5 when the probe support 14 is assembled to the wiring board 12 by the mounting plate 18. Each connection part 48
Penetrates a through hole provided at the inner end of the wiring board 12 and is integrated with the wiring portion 26 at the upper end.

The line 50 connecting the outer ends of the cuts 46 is shown in FIG.
2 is a rectangle similar to the opening 34 as shown by a broken line and by a solid line in FIG. The portion of the probe support 14 inside the line 50 is slightly bent toward the metal plate 36 (downward) at the line 50. This is a metal plate 3
6 can be achieved by permanently deforming the portion corresponding to the line 50.

Each probe needle 16 is made of a conductive metal wire such as a tungsten wire, and is bent in an L-shape. Each of the probe needles 16 has a distal end portion protruding downward through the hole 40 of the probe support 14 and a rear end portion extending outwardly along the wiring portion 32 along the upper surface of the wiring portion 32 of the probe support 14. It is arranged at the inner edge of the probe support 14 so as to extend, and is attached to the corresponding wiring portion 32 by solder 52 at the rear end. Instead of the solder 52, the probe needle 16 is formed by using a conductive adhesive.
May be attached to the wiring portion 32.

The mounting plate 18 has an L-shaped cross-section, a hole 54 for receiving the lower end of the positioning pin 28, and a plurality of bolts for mounting the mounting plate 18 below the wiring board 12. 56. Each bolt 56 penetrates a portion between the wiring portions 26 of the wiring board 12 and is screwed to the mounting plate 18.

When assembling the inspection head 10, the probe support 14 is mounted on the mounting plate so that the positioning pin 28 extends downward through the hole 42 and the projection 44 is pressed against the lower surface of the connection portion 48. 18 assembles to the wiring board 12. Wiring board 12, probe support 14, and mounting plate 1
8 are coaxially positioned by pins 28 such that their axes coincide.

At the time of the energization test, the inspection head 10 first
The relative position between the tip of the probe 16 and the electrode of the device under test is confirmed from the hole 40, and alignment for positioning the probe 16 and the device under test is performed.

Next, the tip of the probe needle 16 is slightly excessively pressed against the electrode of the test object. As a result, a portion of the sheet member 30 inside the line 50 is warped, and the probe needle 16 is warped. This allows
The tip of the probe needle 16 is slightly displaced in contact with the electrode of the device under test, and a rubbing action of rubbing the device under test occurs at the tip of the probe needle 16. As a result, even if an electrical insulating film such as aluminum oxide is formed on the surface of the electrode of the device under test, the electrical insulating film is broken by the tip of the probe needle 16 and good electrical contact is obtained. And the tip of the probe needle 16.

Since the metal plate 36 itself can be elastically deformed, the spring force of the portion of the sheet member 30 inside the line 50 is increased, and the rubbing action of the probe needle 16 is further increased. During the test, the metal plate 36 of the sheet member 30 can be connected to ground. Thereby, the probe needle 1
6 is surrounded by the ground potential except for the tip, and the lower side of the wiring portion 32 is maintained at the ground potential, so that disturbance from the probe needle 16 and the wiring portion 32 is prevented from being mixed.

In the sheet-like member 70 shown in FIG. 6, a wiring pattern is formed on the upper surface of a film made of an electrically insulating material such as a polyimide material, that is, the electrical insulating layer 72, and the wiring portion 32 of the wiring pattern is formed by the electrical insulating layer 38. A metal plate 36 is attached to the upper surface of the cover. For this reason, the sheet-like member 70
Is fixed to the wiring board 12 by the mounting plate 18 so as to be stably sandwiched between the wiring board 12 and the mounting plate 18.

In the sheet members 30 and 70 shown in FIGS. 5 and 6, respectively, instead of forming the holes 40, they correspond to the holes 40 of the sheet members 30 and 70 as shown in FIGS. The part to be cut may be cut off. By doing so, the tip of the probe needle 16 extends downward through the inside of the inner edge of the sheet-like member,
By connecting the metal plate 36 to the ground, the intrusion of disturbance from portions other than the tip of the probe needle 16 is prevented.

Instead of using the L-shaped probe needle 16 to extend the rear end thereof along the wiring portion 32, as shown in FIG.
And the rear end of the probe needle 76 is electrically
And the wiring portion 32, and the rear end of the probe needle 76 may be attached to the wiring portion 32 by soldering or the like. In the case of the embodiment shown in FIG. 9, after attaching the probe needle 76 to the wiring portion 32, the electrical insulating layer 38 and the metal plate 36 are attached to the electrical insulating layer 72.
And the wiring part 32.

The present invention is not limited to the above embodiment. For example, when the electric insulating layer 38 of the sheet-like member 30 has a large spring force, the metal plate 36 may not be provided. Also,
Instead of forming the cut 46 in the sheet-like member, a portion of the adjacent wiring portion 32 on the probe needle 16 side may be cut off, and the wiring portion 32 may be warped. Further, the present invention can be applied not only to an inspection head for an integrated circuit but also to an inspection head for another flat object to be inspected such as a liquid crystal display panel.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of an inspection head according to the present invention.

FIG. 2 is a plan view showing one embodiment of a probe support.

FIG. 3 is a sectional view taken along line 3-3 in FIG.

FIG. 4 is an enlarged plan view showing a part of the center of the inspection head.

FIG. 5 is an enlarged sectional view taken along line 5-5 in FIG.

FIG. 6 is a sectional view similar to FIG. 5, showing another embodiment of the probe support.

FIG. 7 is a cross-sectional view showing another embodiment of a method for arranging probe needles.

FIG. 8 is a sectional view showing still another embodiment of a method for arranging probe needles.

FIG. 9 is a sectional view showing still another embodiment of a method for arranging probe needles.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Inspection head 12 Wiring board 14 Probe support 16 and 76 Probe needle 18 Mounting plate 24 Opening of wiring board 26 Wiring part of wiring board 28 Pin for positioning 30 and 70 Sheet member 32 Wiring part of probe support 34 Probe Supporting opening 34 36 Metal plate 38,72 Electrical insulating layer 40 Hole 44 Projection for connection 46 Notch 52 Solder 56 Mounting bolt

Claims (6)

[Claims] 1. An inspection head used for testing a flat object to be inspected, said probe head comprising: an elastically deformable probe support; and a plurality of probe elements arranged on said probe support. Comprises an elastically deformable sheet-like member, and a plurality of wiring portions formed on one surface of the sheet-like member, and each prog element corresponds to the wiring portion and is electrically connected to the corresponding wiring portion. An inspection head, wherein the probe needles are made of metal and are conductively attached to the probe member, and the tip of each probe needle protrudes from the sheet-like member to the side opposite to the wiring section. 2. The sheet-shaped member includes an elastically deformable sheet-shaped metal plate, and an electric insulating layer formed on one surface of the metal plate, the surface being opposite to the metal plate. The head according to claim 1, further comprising: an electrical insulating layer on which a wiring portion is formed. 3. The sheet-shaped member is an elastically deformable sheet-shaped metal plate and a first electric insulating layer formed on one surface of the metal plate, the first electric insulating layer being opposite to the metal plate. A first electrical insulating layer having the wiring portion formed on a side surface thereof; and a second electrical insulating layer formed on the wiring portion side surface of the first electrical insulating layer so as to cover the wiring portion. The head of claim 1, comprising a layer. 4. A wiring board having a plurality of wiring portions electrically connected to a wiring portion of the probe support, wherein the wiring board and the sheet-like member have an opening in the center, The sheet-like member according to any one of claims 1 to 3, wherein the probe needle is coaxially coupled to the wiring board such that a tip of the probe needle projects to a side opposite to a side of the wiring board.
Head according to item. 5. The probe according to claim 1, wherein a tip portion of the probe needle extends through the probe support.
Head according to item. 6. The head according to claim 1, wherein a tip portion of each probe needle extends through an inside of a surface forming an opening of the probe support.