JP2976321B2 - 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.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process,
After the wafer process is completed and an IC chip is completed in the wafer, an electrical measurement called a probe test is performed to examine a short circuit and an open of an electrode pattern and an input / output characteristic of the IC chip. The quality of the IC chip is determined in the state of “wafer”). After that, the wafer is divided into IC chips, and a good IC
After the chip is packaged, for example, a predetermined probe test is performed to determine the quality of the final product.

[0003] In this probe apparatus, as shown in FIG. 4, an electrode pad arrangement of IC chips in a wafer W is provided above a wafer holding table 1 movable in, for example, X, Y, Z, and θ directions. The probe card 12 provided with the probe needles 11 arranged in a row is arranged, and the wafer holding table 1 is moved to align the electrode pads of the IC chip in the wafer W with the probe needles 11. The electrode pads are brought into contact with the performance board 16 of the test head 15 via the probe needle 11 and the contact ring 14 including the pogo pins 13 and the like, and for example, a high frequency corresponding to the operating speed of the IC is used. Electrical measurement is performed to determine the quality of the IC chip.

[0004] When measurement is performed using high-frequency pulses, the probe card 12 and the performance board 16 are used.
Has a connection structure as shown in FIG. That is, a shield pipe 2 made of gold plated with brass is provided around each pogo pin 13 for signal transmission so as to surround the pogo pin 13, and a pogo pin 21 for grounding is arranged adjacent to the pipe 2. The pogo pins 21 for grounding are connected by a metal plate 22, thus forming a shield structure.

[0005]

In the connection between the probe card 12 and the performance board 16, the impedance of the conductive path with respect to the ground is constant at the portion where the shield pipe 2 is provided. In the contact portions at both ends of 13, it is necessary to separate the signal terminal from the ground, so that a gap must be formed, and this portion becomes high impedance.

On the other hand, recently, the degree of integration of devices has rapidly increased, and at the same time, the operating speed has tended to increase further.
Along with this, when testing devices in the future, it is expected that the signal frequency will be as high as about 1 GHz. Therefore, if the impedance of the conductive path with respect to the ground is high impedance as described above, the waveform of the signal pulse is distorted, and it becomes difficult to perform highly accurate electrical measurement.

When a pogo pin is used, there is contact resistance between the end of the pogo pin and the electrode, and there are many contact points due to the combination of a spring and a ball. There is also a problem that the pulse waveform cannot be obtained, and furthermore, since the signal pogo pin and the ground pogo pin are paired, the area occupied by one pin is large,
There is also a problem that high-density mounting is difficult.

The present invention has been made under such circumstances, and an object of the present invention is to provide a probe device capable of performing high-precision electrical measurement when measuring using a high-frequency signal. It is in.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a probe card and a wiring board on a measuring section side are opposed to each other, and these conductive paths are electrically connected to each other. And the electrode pad of the test object
In a probe device for electrically measuring an object to be inspected by a measuring unit, a conductive material for a shield interposed between a probe card and a wiring board so as to be joined to a board surface of the probe card and a board surface of the wiring board. Block body, a large number of through-holes formed in the block body so as to be orthogonal to the substrate surface of the probe card, and inserted into the through-hole in the axial direction so as not to contact the inner wall of the through-hole, A probe card comprising: a conductor shaft having both ends electrically connected to a contact of a probe card and a conductive path of a wiring board; and an insulator interposed between the conductor shaft and an inner wall of the through hole. And the wiring board can be separated and connected to each other via a block body.

[0010]

By connecting the probe card and the wiring board via the block body, the contact on the probe card side is connected to the measuring circuit in the measuring section via the conductor shaft and the conductive path of the wiring board. By grounding the block body via, for example, a wiring board, the probe card and the wiring board have a completely coaxial structure, so that high-speed signals can be accurately measured even using a high-frequency signal. Can be tested.

[0011]

FIG. 1 is a side view showing the entire configuration of an embodiment of the present invention, and FIG. 2 is an enlarged sectional view showing a main part of the embodiment.
In the figure, reference numeral 3 denotes a wafer mounting table, and the wafer mounting table 3
The drive mechanism 31 is configured to be driven in a small amount in the X, Y, and θ directions (around the vertical axis) and to be driven in the Z direction, for example.

A circular probe card 4, for example, is provided on the upper surface of the wafer mounting table 3 so as to face the wafer mounting table 3. The probe card 4 has an aminium block as an intermediate connector as described later. It is detachably fixed to the test head through the intermediary. The probe card 4
Has a flexible multilayer wiring substrate 41 using, for example, polyimide as a substrate material, and contacts arranged on the lower surface side of the multilayer wiring substrate 41, for example, bumps 42 which are conductive projections.

The bumps 42 are arranged corresponding to all the electrode pads of the wafer W, for example, so as to come into contact with the electrode pads of all the chips at once, for example, 18 gold, tungsten, or nickel alloy. Etc. In the multilayer wiring board 41, a large number of wiring layers 40 as conductive paths are laminated, and a ground layer 40a is provided between both upper and lower surfaces of the multilayer wiring layer and between the wiring layers 40.

A ring-shaped conductive first block body, for example, a first block body 5 made of aluminum is joined to a peripheral portion on the upper surface side of the probe card 4 so as to cover the entire substrate surface of the peripheral portion. The first block body has a large number of through holes 51 extending from the upper surface to the lower surface. However, in this example, the multilayer wiring board 41 and the first
A reinforcing substrate 43 in which copper foil is adhered to both surfaces of an insulating substrate is interposed between the block body 5 and the block body 5.

A conductor shaft 52 is coaxially inserted into each of the through holes 51 so as not to contact the inner peripheral wall of the through hole 51. The lower end of the conductor shaft 52 penetrates the multilayer wiring board 41 and has a lower surface. It is slightly more protruding. The hole through which the conductor shaft 52 is penetrated in the multilayer wiring board 41 forms a through hole 53 in which, for example, a copper foil is adhered to the inner peripheral wall, and the lower end of the conductor shaft 52 is soldered to the metal foil of the through hole 53. Is attached. These through holes 53 are provided corresponding to the bumps 42, and are electrically connected to the respective bumps 42 via wiring layers in the multilayer wiring board 41.

Between the through hole 51 and the conductor shaft 52,
As shown in FIG. 3, an insulator 54 made of, for example, polypropylene or the like is interposed to insulate them, and the insulator 54 has, for example, a female mold having a concave portion 55 in which an inverted conical shape and a cylindrical shape are combined. Made in. The upper end of the conductor shaft 52 projects into the concave portion 55, and the tip is a male type that fits into a conductor shaft 72 described later. By forming the coaxial structure in this way, it is possible to adjust the impedance matching with respect to the high frequency used as the test signal and to improve the high frequency characteristics.

On the other hand, above the probe card 4,
A test head 6 forming a part of the measurement unit is supported and arranged by a support mechanism (not shown). This test head 6 is called a performance board or the like on the lower surface side.
For example, a wiring board 61 based on an insulating material such as glass or epoxy resin is provided so as to face the probe card. The wiring board 61 includes a multilayer wiring layer 60 and a ground layer (not shown), like the substrate 41 of the probe card 4.

On the lower surface side of the wiring board 61, the first
A ring-shaped conductive second block body, for example, a second block body 7 made of aluminum is joined to a substrate surface corresponding to the block body 5 of FIG. Blocks 5 and 7
For example, gold plating is applied to the joint surfaces of the blocks and the joint surfaces of the block bodies 5 and 7 on the probe card 4 and wiring board 61 side. The copper foil 62 on the block 7 side of the wiring board 61 is grounded.

In the block body 7, as in the case of the first block body 5, a through hole 71 is formed at a position corresponding to the through hole 51, and each of the through holes 71 has a conductor shaft 72 and an insulator. The upper end of the conductor shaft 72 is soldered through the through hole 73 of the wiring board 61. However, the insulator 74 has a male structure that fits into the female insulator 54 on the first block body 5 side, and the tip of the conductor shaft 72 has a female structure that fits into the conductor shaft 52. It has become.

Next, the operation of the above embodiment will be described. First, the probe card 4 is connected to the wiring board 61 on the test head 6 side.
To the underside of the This mounting is performed by the first block body 5
And the second block body 7 are opposed to each other, and the insulating portions 54 and 74 in the corresponding through holes 51 and 71 are fitted to each other. As a result, the conductor shafts 52 and 72 are fitted to each other to be surely electrically connected, and the blocks 5 and 7 are in surface contact with each other, so that the conductor shafts 52 and 72 are surrounded by the blocks 5 and 7. However, since the block bodies 5 and 7 are grounded, the conductor shafts 52 and 72 are electrically shielded, and the bumps 41 are electrically connected to the test head 6 through the conductor shafts 52 and 72.

After the wafer W to be inspected is mounted on the wafer mounting table 3 by a transfer means (not shown), for example, an optical system is inserted between the probe card 4 and the wafer mounting table 3 to drive the drive mechanism 31. The wafer mounting table 31 by X, Y, θ
, The wafer W is aligned with the probe card 4, and then the wafer mounting table 3 is raised.
The bumps 41 arranged on the probe card 4 are collectively brought into contact with the electrode pads of all the chips on the wafer W. In this case, if the arrangement area of the bumps 41 on the upper surface side of the probe card 4 is pressed to the lower surface side by pressing means, a buffer 60 such as a spring or an air mat or a rubber body as shown by a chain line in FIG. Wiring board 6
If the bump 41 is interposed in a state where a restoring force is acting between the bumps 41, the bumps 41 are in contact with the electrode pads of the chip being pressed, and reliable electrical contact is achieved. Thereafter, the test head 6 gives a predetermined pulse signal to the chips of the wafer W,
A pulse signal from the chip is taken in to determine the quality of the chip.

According to this embodiment, since the probe card 4 and the wiring board 61 on the test head 6 side can be electrically connected with a perfect coaxial structure, the impedance of the conductive path with respect to the ground can be made constant. Therefore, waveform distortion can be suppressed even when a pulse of a high frequency, for example, 1 GHz or more is used, and the influence of external noise can be suppressed as much as possible. Also, the conductor shafts 52 and 72 are respectively connected to the through holes 5.
3 and 63, inserted into the probe card 4 and the wiring board 6
Connected to each of the wiring layers 40, 60, and the conductor shafts 52,
72 is a female type and a male type, respectively, and is fitted to each other, so that the contact resistance can be made much smaller than in the case where a conventional pogo pin is used. As a result, a high-precision electrical measurement can be performed when inspecting the chip using the high-frequency pulse, and the inspection of the chip whose operating speed is increasingly increasing can be accurately performed.

Since the conductor shafts 53 and 73 are surrounded by the aluminum blocks 5 and 7 and do not require individual shield electrodes, the area required for one pin (one shaft) in the blocks 5 and 7 is required. Is small, and therefore can be mounted at a high density. For example, when a structure having a large number of bumps is employed, for example, when the electrodes are collectively contacted with the electrode pads of all the chips of the wafer W as in the above-described example. It is advantageous. Furthermore, the insulators 54 of the block bodies 5 and 7
The probe cards 4 can be automatically positioned with respect to the wiring board 6 by fitting the 74 into each other.

In the above description, the contact of the probe card is not limited to a bump but may be a contact needle made of tungsten or the like, and may not be of a type that contacts all the pads of all chips on the wafer at once. May be of a type that sequentially contacts some of the electrode pads.

The block body may be made of a metal other than aluminum, or may be made of a conductive plastic or an insulator to which a metal foil is adhered. In the above-described embodiment, the block body between the probe card and the wiring board on the test head side can be divided. However, in the present invention, for example, the block body is divided into, for example, a probe without dividing the block body. It is also possible to adopt a configuration that can be fixed to one side of a card or a wiring board and can be separated from the other side.

[0026]

As described above, according to the present invention, a conductive block is provided between the probe card and the wiring board on the measuring section side so as to be joined to the board surface of the probe card and the board surface of the wiring board. In order to electrically connect the probe card and the wiring board, a coaxial structure is obtained by using this block body, so that the conductive path can be shielded without gaps, and as a result, The impedance of the conductive path can be made constant. Therefore, the measurement can be performed with high accuracy even using a high-frequency signal, and an accurate inspection can be performed even for a chip having a high operation speed.

[Brief description of the drawings]

FIG. 1 is a side view showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of the embodiment of the present invention.

FIG. 3 is a partially broken perspective view showing a main part of the embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a conventional probe device.

FIG. 5 is a side view showing a part of a conventional probe device.

[Explanation of symbols]

 Reference Signs List 3 wafer mounting table 4 probe card 41 bump 42 multilayer wiring board 5, 7 block body 51, 71 through hole 52, 72 conductor shaft 54, 74 insulator 6 test head 61 wiring board

Claims (1)

(57) [Claims] 1. A probe card and a wiring board on a measurement section side are arranged to face each other, these conductive paths are electrically connected to each other, and a contact provided on the probe card and an electrode pad of a device under test are connected to each other. And a probe device for performing electrical measurement of the device under test by the measuring unit, wherein the probe device is interposed between the probe card and the wiring substrate so as to be joined to the substrate surface of the probe card and the substrate surface of the wiring substrate. A conductive block body for shielding; a large number of through holes formed in the block body so as to be orthogonal to the substrate surface of the probe card; and an axial direction such that the through hole does not contact an inner wall of the through hole. A conductor shaft, both ends of which are electrically connected to the contact of the probe card and the conductive path of the wiring board, respectively, and an insulator interposed between the conductor shaft and the inner wall of the through hole. Prepared, professional Bukado the wiring board and are separated via a mutually block body, the probe apparatus characterized by being configured to be coupled.