JP2995134B2 - 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 probe card having a having a contact area where arrangement arranged contacts which contact with the intermediate portion to the electrode pads of the device under test flexibility, the contactor arrangement region around the contact arrangement region of the probe card A frame which is provided integrally so as to surround the contact board and has a rigidity for maintaining the parallelism between the contact placement area and the device under test with the lower surface of the printed circuit board as a reference plane, and a back side of the contact placement area of the probe card. And an elastic member for applying a contact pressure to the contact portion when the contact pad of the test object comes into contact with the contact element.

[0007]

By providing a rigid frame on the probe card and providing the probe card with the printed circuit board as a reference plane, the parallelism between the contact placement area and the test object can be maintained. Furthermore, since the probe card has flexibility and an elastic member is provided on the back surface side of the contact arrangement area, when the contact pad of the device under test comes into contact with the contact, the contact portion has 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]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment, FIG. 1 is a longitudinal sectional front view showing a mounting structure of a probe card, FIG. 2 is a perspective view of a probe card, FIG. Is a perspective view of the 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, the main stage 11 is located above the apparatus main body 10.
The opening 40 is provided so as to be opposed to. This opening 4
The opening edge of 0 is formed in a mounting step 41, and a printed board 42 provided to close the opening 40 is fixed to the mounting step 41 by a fixing screw 43.

The printed circuit board 42 has printed wiring layers 45a, 45a on the upper and lower surfaces of an epoxy-based substrate body 44.
5b are formed, and the printed circuit board 42 is provided with a wiring connector group 47 in which a plurality of wiring connectors 46 are arranged symmetrically with respect to a center portion thereof. Further, the wiring connector group 47 is provided with a mounting hole 48 penetrating the printed circuit board 42.

A support block 49 made of a hard synthetic resin material or a metal material is provided on the lower surface of the printed circuit board 42 located between the left and right wiring connector groups 47 with the printed circuit board 42 by a fixing screw or an adhesive. Fixed. The support block 49 is formed in a thick rectangular frame shape, has a central space portion 50, and has an engagement step portion 51 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 board 21a made of a flexible rectangular insulating plate, and is provided at both ends in the longitudinal direction of the board 21a. Is provided with a connector 21c. The connector 21c is provided with a plurality of connector pins 21d electrically connected to the flexible printed circuit 21b, and is provided with a through hole 21e.

Further, a contact placement area 52 is provided in the middle portion of the substrate 21a in the longitudinal direction, and the contact placement area 52 has the same size and the same size as one chip of the semiconductor wafer 12 corresponding to one chip. 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. A rectangular frame 54 made of a rigid material such as an aluminum material is integrally adhered to the upper surface of the substrate 21a located around the contact placement area 52. That is, the substrate 2
Although 1a is made of a flexible material, the whole is rich in flexibility. However, the frame 54 maintains the flatness of the periphery including the contact placement area 52, and restricts expansion and bending. Thus, the pitch of the contacts 53 is maintained.

The probe card 21 configured as described above
The frame 54 is fitted into the engagement step 51 on the lower surface of the support block 49, and is positioned and fixed to the support block 49 by a fixing screw or vacuum suction. The connectors 21c at both ends in the longitudinal direction of the board 21a are respectively positioned in the wiring connector group 47 of the printed board 42, and by connecting the connector pins 21d to the wiring connector 46, the printed board 42 and the probe card 21 are electrically connected. Connected. Further, the connector 21c
The fixing screw 55 is inserted through the through hole 21e provided in the
Is inserted, the fixing screw 55 is inserted into the mounting hole 48 of the printed circuit board 42, and is fixed by tightening the nut 56 on the upper surface side of the printed circuit board 42.

Accordingly, the probe card 21 is electrically and mechanically connected to the printed circuit board 42, and the intermediate portion of the probe card 21 projects slightly below the connector 21c due to the presence of the support block 49. . What is important here is that the mounting table 1
In order to keep the contact arrangement area 52 of the probe card 21 parallel to the semiconductor wafer 12 placed on the third wafer 3, the probe card 21 is attached with the lower surface of the printed board 42 as a reference plane due to the presence of the frame 54. Therefore, the parallelism between the contact placement area 52 and the semiconductor wafer 12 can be easily and accurately maintained.

The space 50 of the support block 49
Accommodates a fluid chamber 57 as an elastic member. The fluid chamber 57 is a flexible bag body in which gas or liquid is sealed, and when a predetermined amount or more of fluid is sealed and pressurized, the upper surface of the fluid chamber 57 is printed circuit board 4.
The lower surface is pressed against the lower surface of the probe card 21 on the lower surface of the probe card 2, and the periphery is surrounded by a guide cylinder 58 for restricting the lateral expansion.

The fluid chamber 57 has 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 connected to a pressure sensor 59.
The opening and closing of the fluid chamber 57 is controlled by the control device 62 based on the pressure detection signal.

For example, the control unit 62 has a CPU 63 for receiving a pressure detection signal from 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.

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.
2 and is electrically connected to the contact ring 6.
A test head 68 is mounted on 6. The test head 68 is connected to a tester 69. Then, the tester 69 applies a predetermined power supply voltage or a test pulse signal to the chip of the semiconductor wafer 12 and fetches an output signal from the chip side 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 a 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.

Next, when the mounting table 13 is raised in the Z direction, that is, when the mounting table 13 is raised, 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.

On the other hand, a predetermined amount of fluid is supplied to a fluid chamber 57 provided on the back side of the probe card 21.
Since the probe card 21 expands and elastically presses the probe card 21 from the back surface side, the electrode pad of the semiconductor wafer 12 is brought into contact with the contact 5
3, and each electrode pad of the semiconductor wafer 12 is electrically connected to the probe card 21 via the contact 53.

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 or 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 providing the rigid frame 54 on the probe card 21 and providing the probe card 21 with the printed board 42 as a reference plane, the parallelism between the contact placement area 52 and the semiconductor wafer 12 can be maintained. it can. Further, the probe card 21 has flexibility,
From the back side of the contact arrangement area 52, the fluid chamber 57
By providing a backup to the contact arrangement area 52, the contact pads of the semiconductor wafer 12 and the contact
When it comes into contact with 3, the 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.

Further, the internal pressure of the fluid chamber 57 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 to supply fluid to the fluid chamber 57 and reduce the internal pressure. Can be raised.

When the internal pressure of the fluid chamber 57 increases due to some influence such as an increase in the ambient temperature, the pressure sensor 59 detects this and sends 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 57 can be discharged and the internal pressure can be reduced.

In the first embodiment, the support block 49 and the connector 21c are provided separately, but the connector 21c may be provided integrally with the support block 49.
FIG. 5 shows a second embodiment, in which the same components as those in the first embodiment have the same reference numerals and description thereof will be omitted. The probe card 70 in this embodiment is obtained by combining a flexible printed circuit (FPC) 71b with a board 71a made of a flexible rectangular insulating plate.
A large number of contact pieces 71c formed of bumps or pads are provided at both ends in the longitudinal direction of 1a. These contact pieces 71c are electrically connected to the flexible printed circuit 71b, and are provided with through holes 71d at both ends of the substrate 71a.

Further, a contact placement area 52 is provided in the longitudinally intermediate portion of the substrate 71a, as in the first embodiment.
A number of contacts 53 of the same size corresponding to one chip and arranged at the same pitch as the electrode pads of the same chip are provided so as to protrude from the lower surface of the substrate 71a.

The contact pieces 71c at both ends in the longitudinal direction of the board 71a are positioned on the electrodes 72 provided on the wiring layer 45b of the printed board 42, respectively.
2 and the probe card 70 are electrically connected. Further, through holes 7 provided at both ends of the probe card 70 are provided.
A fixing screw 55 is inserted into 1d from below, and the fixing screw 55 is inserted into the mounting hole 48 of the printed circuit board 42 and fastened by a nut 56 on the upper surface side of the printed circuit board 42.

The probe card 70 thus configured
According to this, connectors are not required at both ends, and in addition to the effects of the first embodiment, the configuration of the probe card 70 can be simplified, and the connectors do not project to the lower surface side of the printed circuit board 42. There is an effect that interference with other members can be prevented.

[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.

Furthermore, by providing a rigid frame on a flexible probe card and providing the probe card with the printed circuit board as a reference plane, the parallelism between the contact arrangement area and the test object can be maintained. . further,
By providing a backup to the contact placement area by an elastic member from the back side of the probe card, when the contact pad of the DUT comes into contact with the contact, it is possible to elastically apply a contact pressure to the contact portion. it can. 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 a perspective view of the probe card 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 a longitudinal sectional front view of a main part of a probe device showing a second embodiment of the present invention.

[Explanation of symbols]

10: apparatus main body, 12: semiconductor wafer (inspection object), 1
3 mounting table, 21 probe card, 42 printed circuit board, 52 contact placement area, 53 contact, 54 frame, 57 fluid chamber (elastic member).

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; Around the contact placement area
A frame which is provided integrally so as to surround the arrangement area and has rigidity to maintain the parallelism between the contact arrangement area and the device under test with the lower surface of the printed circuit board as a reference plane; and A probe device, comprising: an elastic member provided on a back surface side and applying a contact pressure to a contact portion when the contact pad of the test object comes into contact with a contact. 2. The frame according to claim 1, wherein the frame is formed of an aluminum frame formed in a rectangular frame shape so as to surround the contact arrangement area, and is fixed to the printed circuit board via a support block. Probe device. 3. The elastic member according to claim 1, wherein the elastic member is a fluid chamber in which gas or liquid is sealed.
Or the probe device according to 2.