JPH0644586B2 - Probe device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a test head installed in a probe device, and more particularly to a probe device for high frequency measurement.

(Prior Art) A wafer probe test is one of the tests in the manufacturing process of semiconductor devices such as transistors and integrated circuits (ICs). This probe inspection device connects the electrode pads of each chip formed on the semiconductor wafer to a tester for measuring electrical characteristics, and eliminates semiconductor chips that have been determined to be defective before the assembly process. However, the cost is reduced or the productivity is improved.
The connection between the electrode pad and the tester is made via a probe card.

Depending on the connection type, the tester has a type that connects the probe card of the probe device main body to the tester via a long cable, and the tester is placed directly above the probe card part of the probe device main body. There are two types, a test head type that connects with a tester.

(Problems to be Solved by the Invention) As semiconductor devices have become more highly integrated, multifunctional, and faster, there is a demand for higher test speeds in probe devices as well.

Therefore, the conventional method of connecting a probe card and a tester by connecting a large number of long cables not only makes some devices unable to perform normal measurement due to the measurement frequency, but also loads many long cables and increases the speed. There is a problem. For such devices, analog circuits such as the drivers and comparators described above are built into a board called a pin electronics board, and a test head in which the board is installed for each electrode of the semiconductor chip is installed directly in the probe card. Although a high-frequency type probe device installed and measured on the top is compatible, there are still cases where normal measurement is difficult. The first of the causes
As a conventional test head of this type, the probe card requires an insertion hole for a microscope or the like for accurately positioning the probe needle on the electrode pad of the semiconductor chip formed on the wafer. can give. The provision of this insertion hole selects the shortest distance by providing the probe needle along the edge of this insertion hole, but of course the distance becomes longer due to the size of the insertion hole, and the test head Will increase the impedance of various electric circuit boards. That is, the high frequency characteristics are significantly deteriorated.

The present invention has been made in order to improve the above points, and provides a probe device which enables measurement by a high frequency signal and also enables high speed measurement.

[Structure of Invention]

(Means for Solving the Problem) The present invention relates to a probe card provided with a probe needle corresponding to an electrode pad of a semiconductor chip formed on a semiconductor wafer mounted on a wafer chuck, and a connection between the probe needle and wiring. In a probe device including pin electronics for measuring electrical characteristics of the semiconductor chip, a test head having the pin electronics built therein, and a camera for capturing an image of the electrode pad and the probe needle through an optical fiber. By inserting the optical fiber into the hole formed in the test head and making the hole sufficiently small, the pin electronics arranged in the test head is brought close to the probe needle, and the wiring connecting the two is connected. To provide a probe device characterized by being shortenable. It

[Work]

In the probe device of the present invention, the pin electronics are arranged in the test head so that the test electronics can be connected by shortening the wiring between the pin electronics and the probe needle by forming a hole small enough to insert an optical fiber. It is possible to improve the measurement function at high frequencies by avoiding the influence of capacitance and impedance, which are caused by the conventional bypass line.

(Embodiment) A probe device for high frequency measurement according to an embodiment of the present invention will be described below with reference to the drawings.

This kind of probe device is a pin electronics board
A probe card unit with a test head (2) in which various analog circuit units are installed on a substrate called (1) and the electric substrate (1) is installed for each electrode pad of many semiconductor chips provided on a semiconductor wafer. Place it directly above (3).
The probe card unit (3) has probe needles (5) that come into contact with the electrode pads formed on each chip on the wafer (4) in order to inspect the electrical characteristics, and are provided in the head plate of the probe device. It is held by the ring insert. The test head (2) rotates around the hinge part attached to the side of the probe device body,
(3) Installed on top. The probe heads ( 5) of the test head (2) and the probe card section (3) are connected as follows: test head (2) -wiring-board-pogo pin-board-wiring-board-probe card section (3). However, there is also an effective method of fixing the linear probe card (3) to the test head (2) and shortening the wiring, that is, the measurement cable.

In the embodiment of the present invention, the state of the probe card (3) and the wafer (4) is imaged and used as a means for monitoring the tip condition of the probe needle and the electrode pad, and input to the CRT to observe the CRT and the wafer. Since the adjustment of the position adjustment is performed, the insertion hole for the microscope (6) and the like, which is required for the conventional test head (2) , may be eliminated.

As a result, the pin electronics board inside the test head (2) can be arranged even in a portion where a cylindrical hole for inserting the conventional microscope (6) or the like exists. Further, the line length for connecting the test head (2) and the probe card (3) can be shortened.

This means that it is possible to provide a test head (2) that can suppress the capacitance impedance to a low level and thus can measure at high frequencies.

The optical system for the ITV camera, which monitors the alignment of the electrode pad on the wafer (4) and the probe needle (5), is the first
As shown in FIGS. (A) and (b), the ITV camera can be set at a desired position by using the optical fiber (7). Although there is a loss of light, there is no deterioration in electrical characteristics, so this probe device has a remarkable effect.

As the first method, as shown in Fig. 1 (a), the test head
(2) If the probe card (3) has a thin hole (8) that does not affect the impedance of the probe needle (5), the optical fiber (7), for example, a large aperture optical fiber By inserting, the fiberscope can be positioned almost directly above the probe needle (5) so that the alignment state can be monitored. (FIG. 1 (a)) It is more preferable that a large number of optical fibers are bundled in this optical fiber and the front incident light surfaces are arranged in a plane.

It is possible to collect a sufficient amount of light by using the large aperture optical fiber (7).

Also, when not making a hole in the test head (2) ,
For example, a fiberscope may be attached along the lower surface of the test head (2) , and the probe needle (5) and the state of the chip position on the wafer (4) may be monitored from above the probe needle (5). . (FIG. 1 (b)) In the present invention, the pin electronics board (1) in the test head (2) is designed to shorten the line length distance between the pin electronics board (1) and the probe needle (5) as much as possible. Since it is a probe device in which the insertion hole of the microscope (6) etc. of is small or deleted, the fiber (7) described above
It is obvious that the same effect can be obtained even if the probe inspection is carried out by combining the other wafer (4) and the probe needle (5) with a device capable of detecting, without being limited to the embodiment of use.

Further, since it is not necessary to provide a structure for inserting an additional object such as a microscope (6) in the probe device, it is effective in simplifying and downsizing the probe device.

Further, in the above embodiment, an example in which the alignment of the electrode pad of each chip and the probe needle was monitored by the ITV camera was explained, but of course, if the microscope is set at the ITV camera setting position of the optical fiber (7), the It goes without saying that the scope can also be visually monitored.

〔The invention's effect〕

As described above, according to the present invention, the state of the electrode pad on the semiconductor wafer and the probe needle of the probe card is imaged by the camera through the optical fiber inserted into the hole formed in the test head, and the test is performed. Since the pin electronics are arranged in the test head so that the holes drilled in the head can be made sufficiently small and the wiring between the pin electronics and the probe needle can be shortened and connected, the capacitance generated by the conventional bypass line path, This has the effect of avoiding the effects of impedance and enhancing the measurement function at high frequencies.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining an embodiment of a probe device according to the present invention, and FIG. 2 is a schematic diagram for explaining a conventional probe device. 1 ... Pin electronics board 2 ... Test head 3 ... Probe card 5 ... Probe needle

Claims (1)

[Claims] 1. A probe card provided with a probe needle corresponding to an electrode pad of a semiconductor chip formed on a semiconductor wafer mounted on a wafer chuck; and electrical characteristics of the semiconductor chip connected to the probe needle by wiring. In a probe device equipped with a pin electronics for measuring the, a test head having the pin electronics built-in, and a camera for capturing an image of the electrode pad and the probe needle through an optical fiber, the test head is provided with a hole. By inserting the optical fiber into the hole and making the hole small enough, the pin electronics arranged in the test head can be brought close to the probe needle, and the wiring connecting them can be shortened. Probe device.