JP2963828B2 - Probe device - 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 device for measuring electrical characteristics of a device under test such as a semiconductor device.

[0002]

2. Description of the Related Art As is well known, a large number of semiconductor devices are formed on a semiconductor wafer by using a precision photo transfer technique or the like.
Thereafter, the wafer is cut for each semiconductor device. In the manufacturing process of such a semiconductor device, a test determination of electrical characteristics of a semi-finished semiconductor device is conventionally performed using a probe device in a semiconductor wafer state, and as a result of the test measurement, it is determined that the semiconductor device is non-defective. Only those that have been sent are sent to a post-process such as packaging to improve productivity.

[0003] The probe device includes a mounting table as a test object mounting table configured to be movable in XYZ-θ directions, and a semiconductor device as a test object is mounted on the mounting table. A probe card having a large number of probe needles corresponding to the electrode pads on the wafer is fixed. Then, the semiconductor wafer is set on the mounting table, the mounting table is driven to bring a probe needle into contact with the electrode pad of the semiconductor wafer, and test measurement is performed by a tester via the probe needle.

[0004]

However, in recent years, semiconductor devices have been increasingly miniaturized, the degree of integration of circuits has been increased, the size of electrode pads has been miniaturized, and the intervals between them have become extremely narrow. For example, each electrode pad of the semiconductor device has a side of 60 μm to 100 μm square, and the pitch distance between the electrode pad rows is 100 μm to 200 μm.
μm. Therefore, as described above, it is technically difficult to arrange, for example, hundreds of probe needles in a limited space of the probe card, and it is approaching its limit.

The present invention has been made in view of the above circumstances. It is an object of the present invention to miniaturize the size of electrode pads and to increase the intervals between the electrode pads with the miniaturization of semiconductor devices. However, the contacts can be arranged on the probe card corresponding to the electrode pads, the contacts can be reliably positioned and contacted with the electrode pads, and the electrical characteristics of the semiconductor device can be measured. It is an object of the present invention to provide a probe device which can be performed with high accuracy.

[0006]

In order to achieve the above object, the present invention provides an apparatus main body having a mounting table for mounting an object to be inspected, and a mounting table provided on the apparatus main body. The printed circuit board facing the object to be inspected placed on the, and both ends are electrically connected to the wiring layer of the printed circuit board,
A flexible probe card having a contact arrangement region in which a contact for contacting the electrode pad of the test object is arranged in an intermediate portion, and a fluid provided on the back side of the contact arrangement region of the probe card A fluid chamber connected to a supply source and capable of expanding and contracting to apply a contact pressure to the contact portion when the contact pad and the contact of the test object come into contact with each other, and detecting the pressure of the fluid chamber. A control device for controlling the fluid supply amount to control the internal pressure of the fluid chamber.

[0007]

A fluid chamber is provided on the back side of the contact arrangement area of the probe card, and by controlling the internal pressure of the fluid chamber, when the contact pad of the device under test comes into contact with the contact, the contact portion has an elasticity. A contact pressure can be applied to the contact pad of the test object, and even if there is some unevenness, the two fit and the contact pad and the contact come into contact with each other to be in an electrically conductive state.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are vertical front views showing a mounting structure of a probe card, FIG. 3 is a configuration diagram of the entire probe device, and FIG. 4 is a perspective view of a mounting table.

In FIG. 3, reference numeral 10 denotes a probe device main body, and a main stage 11 is provided substantially at the center. A mounting table 13 for a semiconductor wafer 12 as an object to be inspected, which will be described later, is attached to the main stage 11. The main stage 11 is movable with the mounting table 13 in the X direction and the Y direction in a horizontal plane. Above the mounting table 13, a probe mechanism 14 described later is provided. Although not shown, an alignment unit is provided on the front side of the center of the apparatus main body 10. This unit is provided with a camera as an image recognition device for alignment. For alignment, the mounting table 13 is moved below the camera.

On the right side of the apparatus main body 10, an autoloader 15 is provided.
However, a probe card exchange 16 is provided on the left side, respectively. In the autoloader 15, a wafer cassette 17 that accommodates a large number of semiconductor wafers 12 at predetermined intervals in a vertical direction is exchangeably arranged on a cassette mounting table. The wafer cassette 17 and the mounting table 1 described above
3 and a loader stage 19 movable in a horizontal plane.
And a wafer handling arm 20 that can be driven by a Y-direction drive mechanism and a Z-direction elevating mechanism (not shown). When performing a probe test on the semiconductor wafer 12, the wafer is transported by the loader stage 19 to the vicinity of the mounting table 13, and is handled by the handling arm 20.
Moved up. After the inspection, the wafer is transferred onto the loader stage 19 by the handling arm 20 and transferred to the wafer cassette 17 by the loader stage 19.

In the probe card exchange 16, a plurality of types of probe cards 21, which will be described later, are supported by a card holder 22 and are accommodated at predetermined intervals in the vertical direction.

The mounting table 13 will be described in more detail with reference to FIG. The mounting table 13 includes an X stage 31a movable in the X direction along two rails extending in the X direction, and an X stage 31a along the two rails extending in the Y direction on the X stage 31a. And a Y stage 31b movable in the Y direction. This X, Y stage 31a, 3
1b is driven in a horizontal plane in the X and Y directions by a conventional drive mechanism including a pulse motor or the like. The chuck 32 mounted on the Y stage 31b is driven in a vertical direction (Z direction) by a conventional elevating mechanism, and is rotated by a conventional rotating mechanism around a center line passing through the center thereof and parallel to the Z axis. It has become so.

A lifting mechanism 34 is provided on the side of the Y stage 31b.
Has been fixed. The elevating mechanism 34 holds a movable camera 33 that can move up and down in the vertical direction. The moving camera 33 includes a high magnification section 33a and a low magnification section 33b.

A small piece 35 that projects horizontally in the radial direction is fixed to the side surface of the chuck 32. This small piece 35
Is formed of a conductive thin film, for example, an ITO (indium tin oxide) thin film or a strip-shaped transparent plate having a target 35a defined by the center of a cross mark drawn using chromium formed on the surface. This functions as a reference point for detection by the camera 33. Further, a conductive transparent thin film, for example, I
A thin film of TO is provided. The conductive transparent thin film is provided to enable position detection in the Z direction by the capacitance sensor.

Small piece 35 on which target 35a is formed
Is moved on the optical axis of the high magnification portion of the moving camera 33 by the rotation of the chuck 32 and can be retracted therefrom. Further, the small piece 35 may be configured to be detachably attached to the chuck 32.

The probe mechanism 14, which is an essential part of the present invention, is configured as shown in FIGS. That is, an epoxy-based printed circuit board 42 is fixed to the upper part of the apparatus main body 10 so as to face the main stage 11. A support block 49 made of a hard synthetic resin material or a metal material is fixed to the lower surface of the printed circuit board 42 with a fixing screw or an adhesive. The support block 49 is formed in a thick rectangular frame shape, and has a central space 50 formed therein.
An engagement step 51 is formed on the lower surface. The probe card 21 is detachably attached to the link substrate 42 while the probe card 21 is supported by the support block 49.

That is, the probe card 21 is formed by combining a flexible printed circuit (FPC) 21b with a substrate 21a made of a flexible rectangular insulating plate, and is provided at both ends in the longitudinal direction of the substrate 21a. Is provided with a connector 21c. The connector 21c is provided with a plurality of connector pins (not shown) electrically connected to the flexible printed circuit 21b, and is electrically connected to the printed board 42.

Further, a contact placement area 52 is provided at a longitudinally intermediate portion of the substrate 21a. The contact placement area 52 has the same size and the same size as one chip of the semiconductor wafer 12. A large number of contacts 53 arranged at the same pitch as the electrode pads are provided so as to protrude from the lower surface of the substrate 21a.

The space 50 of the support block 49
Houses a fluid chamber 54. The fluid chamber 54 is formed by a flexible bag body in which gas or liquid is sealed. This fluid chamber 5
On the lower surface of 4, a flat contact plate 55 having rigidity is provided. The contact plate 55 includes a base 56 having rigidity such as a metal plate or a hard synthetic resin and a base 56 provided on the lower surface thereof.
The contact plate 55 is joined to the back surface of the contact placement area 52 formed on the probe card 21.

A guide member 58 for restricting lateral expansion is provided around the fluid chamber 54 including the contact plate 55, and a lower end of the guide member 58 is in contact with the peripheral edge of the contact plate 55 to be in contact with the fluid. A stopper 58a for regulating the lowering stroke of the chamber 54 is provided integrally. When a predetermined amount or more of fluid is supplied to the fluid chamber 54 and pressurized, the fluid chamber 54 expands and the upper surface thereof comes into pressure contact with the lower surface of the printed circuit board 42 and the lower surface thereof comes into pressure contact with the rear surface of the probe card 21 via the contact plate 55. When the pressure is reduced in the inside from which the fluid is discharged, the contact plate 55 contracts and separates from the back surface of the probe card 21.

Further, the fluid chamber 54 is provided with a pressure sensor 59 and a fluid inlet 60 and a fluid outlet 61 connected to a fluid supply source (not shown). The fluid inlet 60 and the fluid outlet 61 are provided with electromagnetic valves 60a and 61a, respectively. The electromagnetic valves 60a and 61a are controlled to open and close by a control device 62 based on a pressure detection signal of a pressure sensor 59, so that the pressure of the fluid chamber 57 is controlled.

For example, the control unit 62 has a CPU 63 for receiving a pressure detection signal of the pressure sensor 59 and a C
The electromagnetic valves 60a, 60
1a, a flow controller 64 for adjusting the opening / closing and opening degree,
65 are provided.

The probe card 21 configured as described above
The connectors 21c at both ends of the board 21a are fitted to the engagement step portions 51 on the lower surface of the support block 49, and are positioned and fixed to the support block 49 by fixing screws or vacuum suction. At the same time, the connectors at both ends in the longitudinal direction of the board 21a are connected to the printed board 42 and the probe card 21.
Are electrically connected.

Accordingly, the probe card 21 is electrically and mechanically connected to the printed circuit board 42. In FIG. 3, reference numeral 66 denotes a contact ring provided on the upper portion of the printed circuit board 42, on which conductive pins 67 projecting up and down are arranged and electrically connected to the printed circuit board 42. Is mounted with a test head 68. This test head 6
8 is connected to a tester 69. And tester 69
Transmits a predetermined power supply voltage and a test pulse signal to the semiconductor wafer 12.
And the output signal from the chip side is taken in to determine the quality of the chip.

Next, the operation of the probe device configured as described above will be described. First, the wafer cassette 17
Is held by the handling arm 20 and transferred to the mounting table 13 of the main stage 11. The mounting table 13 is provided with a chuck 32, and after chucking the semiconductor wafer 12, the position of the chuck 32 in the X, Y, and θ directions is adjusted by a known means, so that the probe card 21 and the semiconductor wafer 12 in the planar direction are adjusted. Perform positioning.

In this case, for example, 64 semiconductor chips are formed on one semiconductor wafer 12, and the probe card 21 is provided with the contact arrangement area 52 corresponding to one semiconductor chip. , The chuck 32 is X,
The positions in the Y and θ directions are adjusted, and the contact placement area 52 of the probe card 21 and the semiconductor chip of the semiconductor wafer 12 are positioned.

On the other hand, when the fluid chamber 54 provided on the back side of the probe card 21 is in a reduced pressure state, FIG.
As shown in FIG. 2A, the fluid chamber 54 contracts and the contact plate 55 is separated from the back surface of the probe card 21, but when a predetermined amount of fluid is supplied to the fluid chamber 54, FIG. ), The probe card 21 expands and elastically presses the probe card 21 from the back side via the contact plate 55,
The contact placement area 52 of the probe card 21 projects downward.

Next, when the mounting table 13 is raised in the Z direction, that is, when the mounting table 13 is lifted, the electrode pads formed on the semiconductor chips of the semiconductor wafer 12 are brought into contact with the contact placement area 52 of the probe card 21.
Contacts the contact 53 provided in the contact. That is, as the mounting table 13 is raised, the electrode pads of the semiconductor wafer 12 are elastically pressed against the contacts 53 of the probe card 21, and each electrode pad of the semiconductor wafer 12 is electrically connected to the probe card 21 via the contacts 53. Connected to.

Accordingly, the semiconductor wafer 12 is electrically connected to the tester 69 from the probe card 21 via the test head 68, and the test head 68 applies a predetermined voltage and a test signal to the semiconductor chips of the semiconductor wafer 12, and The output signal from the chip is taken in to determine the quality of the chip.

By pressing the back side of the contact placement area 52 of the probe card 21 by the fluid chamber 54 via the contact plate 55 in this manner, the contact placement area 52 is pressed.
And the semiconductor wafer 12 can be kept parallel. Further, the probe card 21 is flexible, and the contact chamber 52 is backed up by the fluid chamber 54 from the back side of the contact chamber 52 so that the contact pads of the semiconductor wafer 12 and the contact pads 53 are provided. When contact is made, a contact pressure can be elastically applied to the contact portion. As a result, even if the contact pad of the semiconductor wafer 12 has some unevenness, the two are fitted and the contact pad and the contact 53 are surely brought into contact with each other to be in an electrically conductive state. It can be performed.

The pressure inside the fluid chamber 54 is constantly detected by the pressure sensor 59, and a detection signal is transmitted to the CPU 63. Therefore, when the internal pressure decreases, the CPU 63 outputs a valve opening command signal to the flow rate controller 64, and the flow rate controller 64 controls the opening of the electromagnetic valve 60a, thereby supplying fluid to the fluid chamber 54 and reducing the internal pressure. Can be raised.

When the internal pressure of the fluid chamber 54 increases due to some influence such as an increase in the ambient temperature, the pressure sensor 59 detects this and transmits a detection signal to the CPU 63 so that the CPU 63 By outputting a valve opening command signal to the valve 65 and controlling the electromagnetic valve 61 a to be opened by the flow controller 65, the fluid in the fluid chamber 54 can be discharged and the internal pressure can be reduced.

Further, the fluid chamber 5 including the contact plate 55
4 is surrounded by a guide member 58 and provided with a stopper 58a at the lower end thereof, so that the electromagnetic valves 60a and 61a are provided when the contact plate 55 contacts the stopper 58a.
By closing the valve, the internal pressure of the fluid chamber 54 can be kept constant, and the lowering stroke of the fluid chamber 54 can be regulated by the stopper 58a. Can be prevented beforehand.

In the above-described embodiment, the probe card 21 has, for example, six
Of the four semiconductor chips, one measuring chip corresponding to one semiconductor chip is provided in the contact placement area 52, the position of the chuck 32 is adjusted in the X, Y, and θ directions, and the measuring chip of the probe card 21 is adjusted. And the semiconductor chips of the semiconductor wafer 12 are positioned.
For example, 64 measuring chips corresponding to, for example, 64 semiconductor chips formed on one semiconductor wafer 12 are provided in the contact placement area 52, and 64 semiconductor chips are simultaneously or one by one or more. You may make it measure.

In order to provide a measurement chip on the probe card 21 as described above, a measurement chip pattern 70 having the same size as a semiconductor chip is provided as shown in FIG. Bumps 71 are provided corresponding to the twelve electrode pads.
1, it is necessary to connect a wiring 72 as a power line or a signal line. By the way, a probe card 21 is provided with a plurality of measurement chips.
In the case of 4 multis, the pattern shown in FIG.
In the case of 8 multis, the pattern shown in FIG.

Therefore, in the case of the 4-multi or 8-multi, it is not a problem in terms of space to radially pull out the wiring 72 from the bump 71 located at the outer peripheral portion of the pattern. The adjacent lines 73 where the measurement chip patterns 71 are adjacent to each other are bumps 7
One wiring 72 is required between the bumps 71 and 71. In the case of 8-multi, the portion of the adjacent line 73 where the measurement chip patterns 71 are adjacent to each other requires three wirings 72 between the bumps 71 and 71.

However, with the increase in the density of the semiconductor chips on the semiconductor wafer 12, the electrode pads are densely packed, and the gap between the bumps 71 of the measurement chip pattern 70 is becoming extremely narrow. In the high-density measurement chip pattern 70, as shown in FIG.
The length L of one side is, for example, a square of about 100 μm, and the gap G between the bumps 71 is about 50 to 70 μm. On the other hand, the wiring 72 is formed in a pattern, and its width W is as thin as about 16 μm. However, two wires are limited to pass through the gap G of 50 to 70 μm between the bumps 71. Is impossible. In addition, there are a power line and a signal line in the wiring 72, and the power line needs to be thicker (larger cross-sectional area) as the amount of current increases, and the signal line may be thinner. There are various problems such as the desire to pass a thicker ground line, and the design and manufacture of multi-patterns are limited.

Therefore, in the present invention, FIG.
As shown in FIG. 7, a plurality of measurement chip patterns 73 are continuously arranged in a staggered manner on the probe card 21. By arranging the measurement chip patterns 73 continuously in a staggered manner, there is no adjacent line 73 as shown in FIGS. 5B and 5C. Moreover, a wiring space 74 having the same size as the measurement chip pattern 73 is formed between the measurement chip patterns 73. Therefore, the bumps 71 provided on the outer peripheral edge of each measurement chip pattern 73
The wiring 72 can be drawn radially from the
There is no need to pass the wiring 72 through a narrow gap between the wirings 1, thereby facilitating wiring. As a result, the power line can be made thicker (larger cross-sectional area) to increase the current amount, and a thicker ground line can be passed on both sides of the signal line. Therefore, the design and manufacture of the multi-pattern probe card can be facilitated, and the cost can be reduced.

[0039]

As described above, according to the present invention, by providing the contacts on the flexible probe card, the size of the electrode pads is reduced along with the miniaturization of the semiconductor device, and the space between the electrode pads is reduced. Even if the density is increased, the contacts can be arranged on the probe card corresponding to the electrode pads.

Further, by providing a back-up to the contact arrangement region by the fluid chamber from the back side of the flexible probe card, when the contact pad of the test object comes into contact with the contact, the contact portion is provided. The contact pressure can be elastically applied. As a result, even if there is some unevenness in the contact pad of the test object, the two fit together and the contact pad and the contact are surely in contact with each other to be in an electrically conductive state. This has the effect that it can be performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of a main part of a probe device showing a first embodiment of the present invention.

FIG. 2 is an operation explanatory view of the probe device of the embodiment.

FIG. 3 is an overall schematic configuration diagram of the probe device of the embodiment.

FIG. 4 is a perspective view of the mounting table of the embodiment.

FIG. 5 is an explanatory diagram of a measurement chip pattern showing a modification of the present invention.

[Explanation of symbols]

10: apparatus main body, 12: semiconductor wafer (inspection object), 1
3 mounting table, 21 probe card, 44 printed circuit board, 52 contact placement area, 53 contact, 54 fluid chamber, 62 control device.

Claims (3)

(57) [Claims] An apparatus main body having a mounting table on which an object to be inspected is mounted, a printed circuit board provided in the apparatus main body and facing the object to be inspected mounted on the mounting table, and wiring of the printed circuit board A flexible probe card having both ends electrically connected to the layer, and a contact placement area in which a contact for contacting the electrode pad of the device under test is disposed at an intermediate portion; An inflatable / contractible fluid that is provided on the back side of the probe placement area and is connected to a fluid supply source and applies a contact pressure to the contact portion when the contact pad of the test object comes into contact with the contact. A probe device comprising: a chamber; and a control device that detects a pressure in the fluid chamber and controls a fluid supply amount to control an internal pressure of the fluid chamber. 2. The fluid chamber is guided by a guide member so as to be able to expand and contract in a vertical direction, and the guide member is provided with a stopper for regulating a downward stroke of the fluid chamber. A probe device as described. 3. The fluid chamber has a rigid contact plate on the lower surface thereof, and presses the back surface of the contact arrangement area of the probe card via the contact plate. Item 3. The probe device according to item 1 or 2.